libexec/ftpd/ftpd.c

   1 /*
   2  * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)ftpd.c   8.4 (Berkeley) 4/16/94
  30  * $FreeBSD: src/libexec/ftpd/ftpd.c,v 1.213 2008/12/23 01:23:09 cperciva Exp $
  31  */
  32
  33 /*
  34  * FTP server.
  35  */
  36 #include <sys/param.h>
  37 #include <sys/ioctl.h>
  38 #include <sys/mman.h>
  39 #include <sys/socket.h>
  40 #include <sys/stat.h>
  41 #include <sys/time.h>
  42 #include <sys/wait.h>
  43
  44 #include <netinet/in.h>
  45 #include <netinet/in_systm.h>
  46 #include <netinet/ip.h>
  47 #include <netinet/tcp.h>
  48
  49 #define FTP_NAMES
  50 #include <arpa/ftp.h>
  51 #include <arpa/inet.h>
  52 #include <arpa/telnet.h>
  53
  54 #include <ctype.h>
  55 #include <dirent.h>
  56 #include <err.h>
  57 #include <errno.h>
  58 #include <fcntl.h>
  59 #include <glob.h>
  60 #include <limits.h>
  61 #include <netdb.h>
  62 #include <pwd.h>
  63 #include <grp.h>
  64 #ifdef OPIE
  65 #include <opie.h>
  66 #endif
  67 #include <signal.h>
  68 #include <stdint.h>
  69 #include <stdio.h>
  70 #include <stdlib.h>
  71 #include <string.h>
  72 #include <syslog.h>
  73 #include <time.h>
  74 #include <unistd.h>
  75 #include <libutil.h>
  76 #ifdef  LOGIN_CAP
  77 #include <login_cap.h>
  78 #endif
  79
  80 #ifdef USE_PAM
  81 #include <security/pam_appl.h>
  82 #endif
  83
  84 #include "pathnames.h"
  85 #include "extern.h"
  86
  87 #include <stdarg.h>
  88
  89 static char version[] = "Version 6.00LS";
  90 #undef main
  91
  92 extern  off_t restart_point;
  93 extern  char cbuf[];
  94
  95 union sockunion ctrl_addr;
  96 union sockunion data_source;
  97 union sockunion data_dest;
  98 union sockunion his_addr;
  99 union sockunion pasv_addr;
 100
 101 int     daemon_mode;
 102 int     data;
 103 int     dataport;
 104 int     hostinfo = 1;   /* print host-specific info in messages */
 105 int     logged_in;
 106 struct  passwd *pw;
 107 char    *homedir;
 108 int     ftpdebug;
 109 int     timeout = 900;    /* timeout after 15 minutes of inactivity */
 110 int     maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
 111 int     logging;
 112 int     restricted_data_ports = 1;
 113 int     paranoid = 1;     /* be extra careful about security */
 114 int     anon_only = 0;    /* Only anonymous ftp allowed */
 115 int     assumeutf8 = 0;   /* Assume that server file names are in UTF-8 */
 116 int     guest;
 117 int     dochroot;
 118 char    *chrootdir;
 119 int     dowtmp = 1;
 120 int     stats;
 121 int     statfd = -1;
 122 int     type;
 123 int     form;
 124 int     stru;                   /* avoid C keyword */
 125 int     mode;
 126 int     usedefault = 1;         /* for data transfers */
 127 int     pdata = -1;             /* for passive mode */
 128 int     readonly = 0;           /* Server is in readonly mode.  */
 129 int     noepsv = 0;             /* EPSV command is disabled.    */
 130 int     noretr = 0;             /* RETR command is disabled.    */
 131 int     noguestretr = 0;        /* RETR command is disabled for anon users. */
 132 int     noguestmkd = 0;         /* MKD command is disabled for anon users. */
 133 int     noguestmod = 1;         /* anon users may not modify existing files. */
 134
 135 off_t   file_size;
 136 off_t   byte_count;
 137 #if !defined(CMASK) || CMASK == 0
 138 #undef CMASK
 139 #define CMASK 027
 140 #endif
 141 int     defumask = CMASK;               /* default umask value */
 142 char    tmpline[7];
 143 char    *hostname;
 144 int     epsvall = 0;
 145
 146 #ifdef VIRTUAL_HOSTING
 147 char    *ftpuser;
 148
 149 static struct ftphost {
 150         struct ftphost  *next;
 151         struct addrinfo *hostinfo;
 152         char            *hostname;
 153         char            *anonuser;
 154         char            *statfile;
 155         char            *welcome;
 156         char            *loginmsg;
 157 } *thishost, *firsthost;
 158
 159 #endif
 160 char    remotehost[NI_MAXHOST];
 161 char    *ident = NULL;
 162
 163 static char     ttyline[20];
 164 char            *tty = ttyline;         /* for klogin */
 165
 166 #ifdef USE_PAM
 167 static int      auth_pam(struct passwd**, const char*);
 168 pam_handle_t    *pamh = NULL;
 169 #endif
 170
 171 #ifdef OPIE
 172 static struct opie      opiedata;
 173 static char             opieprompt[OPIE_CHALLENGE_MAX+1];
 174 #endif
 175 static int              pwok;
 176
 177 char    *pid_file = NULL; /* means default location to pidfile(3) */
 178
 179 /*
 180  * Limit number of pathnames that glob can return.
 181  * A limit of 0 indicates the number of pathnames is unlimited.
 182  */
 183 #define MAXGLOBARGS     16384
 184
 185 /*
 186  * Timeout intervals for retrying connections
 187  * to hosts that don't accept PORT cmds.  This
 188  * is a kludge, but given the problems with TCP...
 189  */
 190 #define SWAITMAX        90      /* wait at most 90 seconds */
 191 #define SWAITINT        5       /* interval between retries */
 192
 193 int     swaitmax = SWAITMAX;
 194 int     swaitint = SWAITINT;
 195
 196 #ifdef SETPROCTITLE
 197 char    proctitle[LINE_MAX];    /* initial part of title */
 198 #endif /* SETPROCTITLE */
 199
 200 #define LOGCMD(cmd, file)               logcmd((cmd), (file), NULL, -1)
 201 #define LOGCMD2(cmd, file1, file2)      logcmd((cmd), (file1), (file2), -1)
 202 #define LOGBYTES(cmd, file, cnt)        logcmd((cmd), (file), NULL, (cnt))
 203
 204 static  volatile sig_atomic_t recvurg;
 205 static  int transflag;          /* NB: for debugging only */
 206
 207 #define STARTXFER       flagxfer(1)
 208 #define ENDXFER         flagxfer(0)
 209
 210 #define START_UNSAFE    maskurg(1)
 211 #define END_UNSAFE      maskurg(0)
 212
 213 /* It's OK to put an `else' clause after this macro. */
 214 #define CHECKOOB(action)                                                \
 215         if (recvurg) {                                                  \
 216                 recvurg = 0;                                            \
 217                 if (myoob()) {                                          \
 218                         ENDXFER;                                        \
 219                         action;                                         \
 220                 }                                                       \
 221         }
 222
 223 #ifdef VIRTUAL_HOSTING
 224 static void      inithosts(int);
 225 static void      selecthost(union sockunion *);
 226 #endif
 227 static void      ack(char *);
 228 static void      sigurg(int);
 229 static void      maskurg(int);
 230 static void      flagxfer(int);
 231 static int       myoob(void);
 232 static int       checkuser(char *, char *, int, char **);
 233 static FILE     *dataconn(char *, off_t, char *);
 234 static void      dolog(struct sockaddr *);
 235 static void      end_login(void);
 236 static FILE     *getdatasock(char *);
 237 static int       guniquefd(char *, char **);
 238 static void      lostconn(int);
 239 static void      sigquit(int);
 240 static int       receive_data(FILE *, FILE *);
 241 static int       send_data(FILE *, FILE *, size_t, off_t, int);
 242 static struct passwd *
 243                  sgetpwnam(char *);
 244 static char     *sgetsave(char *);
 245 static void      reapchild(int);
 246 static void      appendf(char **, char *, ...) __printflike(2, 3);
 247 static void      logcmd(char *, char *, char *, off_t);
 248 static void      logxfer(char *, off_t, time_t);
 249 static char     *doublequote(char *);
 250 static int      *socksetup(int, char *, const char *);
 251
 252 int
 253 main(int argc, char *argv[])
 254 {
 255         socklen_t addrlen;
 256         int ch, on = 1, tos;
 257         char *cp, line[LINE_MAX];
 258         FILE *fd;
 259         char    *bindname = NULL;
 260         const char *bindport = "ftp";
 261         int     family = AF_UNSPEC;
 262         struct sigaction sa;
 263
 264         tzset();                /* in case no timezone database in ~ftp */
 265         sigemptyset(&sa.sa_mask);
 266         sa.sa_flags = SA_RESTART;
 267
 268         /*
 269          * Prevent diagnostic messages from appearing on stderr.
 270          * We run as a daemon or from inetd; in both cases, there's
 271          * more reason in logging to syslog.
 272          */
 273         freopen(_PATH_DEVNULL, "w", stderr);
 274         opterr = 0;
 275
 276         /*
 277          * LOG_NDELAY sets up the logging connection immediately,
 278          * necessary for anonymous ftp's that chroot and can't do it later.
 279          */
 280         openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
 281
 282         while ((ch = getopt(argc, argv,
 283                             "468a:AdDEH:hlmMoOp:P:rRSt:T:u:UvW")) != -1) {
 284                 switch (ch) {
 285                 case '4':
 286                         family = (family == AF_INET6) ? AF_UNSPEC : AF_INET;
 287                         break;
 288
 289                 case '6':
 290                         family = (family == AF_INET) ? AF_UNSPEC : AF_INET6;
 291                         break;
 292
 293                 case '8':
 294                         assumeutf8 = 1;
 295                         break;
 296
 297                 case 'a':
 298                         bindname = optarg;
 299                         break;
 300
 301                 case 'A':
 302                         anon_only = 1;
 303                         break;
 304
 305                 case 'd':
 306                         ftpdebug++;
 307                         break;
 308
 309                 case 'D':
 310                         daemon_mode++;
 311                         break;
 312
 313                 case 'E':
 314                         noepsv = 1;
 315                         break;
 316
 317                 case 'h':
 318                         hostinfo = 0;
 319                         break;
 320
 321                 case 'H':
 322                         hostname = optarg;
 323                         break;
 324
 325                 case 'l':
 326                         logging++;      /* > 1 == extra logging */
 327                         break;
 328
 329                 case 'm':
 330                         noguestmod = 0;
 331                         break;
 332
 333                 case 'M':
 334                         noguestmkd = 1;
 335                         break;
 336
 337                 case 'o':
 338                         noretr = 1;
 339                         break;
 340
 341                 case 'O':
 342                         noguestretr = 1;
 343                         break;
 344
 345                 case 'p':
 346                         pid_file = optarg;
 347                         break;
 348
 349                 case 'P':
 350                         bindport = optarg;
 351                         break;
 352
 353                 case 'r':
 354                         readonly = 1;
 355                         break;
 356
 357                 case 'R':
 358                         paranoid = 0;
 359                         break;
 360
 361                 case 'S':
 362                         stats++;
 363                         break;
 364
 365                 case 't':
 366                         timeout = atoi(optarg);
 367                         if (maxtimeout < timeout)
 368                                 maxtimeout = timeout;
 369                         break;
 370
 371                 case 'T':
 372                         maxtimeout = atoi(optarg);
 373                         if (timeout > maxtimeout)
 374                                 timeout = maxtimeout;
 375                         break;
 376
 377                 case 'u':
 378                     {
 379                         long val = 0;
 380
 381                         val = strtol(optarg, &optarg, 8);
 382                         if (*optarg != '\0' || val < 0)
 383                                 syslog(LOG_WARNING, "bad value for -u");
 384                         else
 385                                 defumask = val;
 386                         break;
 387                     }
 388                 case 'U':
 389                         restricted_data_ports = 0;
 390                         break;
 391
 392                 case 'v':
 393                         ftpdebug++;
 394                         break;
 395
 396                 case 'W':
 397                         dowtmp = 0;
 398                         break;
 399
 400                 default:
 401                         syslog(LOG_WARNING, "unknown flag -%c ignored", optopt);
 402                         break;
 403                 }
 404         }
 405
 406         if (daemon_mode) {
 407                 int *ctl_sock, fd, maxfd = -1, nfds, i;
 408                 fd_set defreadfds, readfds;
 409                 pid_t pid;
 410                 struct pidfh *pfh;
 411
 412                 if ((pfh = pidfile_open(pid_file, 0600, &pid)) == NULL) {
 413                         if (errno == EEXIST) {
 414                                 syslog(LOG_ERR, "%s already running, pid %d",
 415                                        getprogname(), (int)pid);
 416                                 exit(1);
 417                         }
 418                         syslog(LOG_WARNING, "pidfile_open: %m");
 419                 }
 420
 421                 /*
 422                  * Detach from parent.
 423                  */
 424                 if (daemon(1, 1) < 0) {
 425                         syslog(LOG_ERR, "failed to become a daemon");
 426                         exit(1);
 427                 }
 428
 429                 if (pfh != NULL && pidfile_write(pfh) == -1)
 430                         syslog(LOG_WARNING, "pidfile_write: %m");
 431
 432                 sa.sa_handler = reapchild;
 433                 sigaction(SIGCHLD, &sa, NULL);
 434
 435 #ifdef VIRTUAL_HOSTING
 436                 inithosts(family);
 437 #endif
 438
 439                 /*
 440                  * Open a socket, bind it to the FTP port, and start
 441                  * listening.
 442                  */
 443                 ctl_sock = socksetup(family, bindname, bindport);
 444                 if (ctl_sock == NULL)
 445                         exit(1);
 446
 447                 FD_ZERO(&defreadfds);
 448                 for (i = 1; i <= *ctl_sock; i++) {
 449                         FD_SET(ctl_sock[i], &defreadfds);
 450                         if (listen(ctl_sock[i], 32) < 0) {
 451                                 syslog(LOG_ERR, "control listen: %m");
 452                                 exit(1);
 453                         }
 454                         if (maxfd < ctl_sock[i])
 455                                 maxfd = ctl_sock[i];
 456                 }
 457
 458                 /*
 459                  * Loop forever accepting connection requests and forking off
 460                  * children to handle them.
 461                  */
 462                 while (1) {
 463                         FD_COPY(&defreadfds, &readfds);
 464                         nfds = select(maxfd + 1, &readfds, NULL, NULL, 0);
 465                         if (nfds <= 0) {
 466                                 if (nfds < 0 && errno != EINTR)
 467                                         syslog(LOG_WARNING, "select: %m");
 468                                 continue;
 469                         }
 470
 471                         pid = -1;
 472                         for (i = 1; i <= *ctl_sock; i++)
 473                                 if (FD_ISSET(ctl_sock[i], &readfds)) {
 474                                         addrlen = sizeof(his_addr);
 475                                         fd = accept(ctl_sock[i],
 476                                             (struct sockaddr *)&his_addr,
 477                                             &addrlen);
 478                                         if (fd == -1) {
 479                                                 syslog(LOG_WARNING,
 480                                                        "accept: %m");
 481                                                 continue;
 482                                         }
 483                                         switch (pid = fork()) {
 484                                         case 0:
 485                                                 /* child */
 486                                                 dup2(fd, 0);
 487                                                 dup2(fd, 1);
 488                                                 close(fd);
 489                                                 for (i = 1; i <= *ctl_sock; i++)
 490                                                         close(ctl_sock[i]);
 491                                                 if (pfh != NULL)
 492                                                         pidfile_close(pfh);
 493                                                 goto gotchild;
 494                                         case -1:
 495                                                 syslog(LOG_WARNING, "fork: %m");
 496                                                 /* FALLTHROUGH */
 497                                         default:
 498                                                 close(fd);
 499                                         }
 500                                 }
 501                 }
 502         } else {
 503                 addrlen = sizeof(his_addr);
 504                 if (getpeername(0, (struct sockaddr *)&his_addr, &addrlen) < 0) {
 505                         syslog(LOG_ERR, "getpeername (%s): %m",argv[0]);
 506                         exit(1);
 507                 }
 508
 509 #ifdef VIRTUAL_HOSTING
 510                 if (his_addr.su_family == AF_INET6 &&
 511                     IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr))
 512                         family = AF_INET;
 513                 else
 514                         family = his_addr.su_family;
 515                 inithosts(family);
 516 #endif
 517         }
 518
 519 gotchild:
 520         sa.sa_handler = SIG_DFL;
 521         sigaction(SIGCHLD, &sa, NULL);
 522
 523         sa.sa_handler = sigurg;
 524         sa.sa_flags = 0;                /* don't restart syscalls for SIGURG */
 525         sigaction(SIGURG, &sa, NULL);
 526
 527         sigfillset(&sa.sa_mask);        /* block all signals in handler */
 528         sa.sa_flags = SA_RESTART;
 529         sa.sa_handler = sigquit;
 530         sigaction(SIGHUP, &sa, NULL);
 531         sigaction(SIGINT, &sa, NULL);
 532         sigaction(SIGQUIT, &sa, NULL);
 533         sigaction(SIGTERM, &sa, NULL);
 534
 535         sa.sa_handler = lostconn;
 536         sigaction(SIGPIPE, &sa, NULL);
 537
 538         addrlen = sizeof(ctrl_addr);
 539         if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
 540                 syslog(LOG_ERR, "getsockname (%s): %m",argv[0]);
 541                 exit(1);
 542         }
 543         dataport = ntohs(ctrl_addr.su_port) - 1; /* as per RFC 959 */
 544 #ifdef VIRTUAL_HOSTING
 545         /* select our identity from virtual host table */
 546         selecthost(&ctrl_addr);
 547 #endif
 548 #ifdef IP_TOS
 549         if (ctrl_addr.su_family == AF_INET)
 550       {
 551         tos = IPTOS_LOWDELAY;
 552         if (setsockopt(0, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
 553                 syslog(LOG_WARNING, "control setsockopt (IP_TOS): %m");
 554       }
 555 #endif
 556         /*
 557          * Disable Nagle on the control channel so that we don't have to wait
 558          * for peer's ACK before issuing our next reply.
 559          */
 560         if (setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
 561                 syslog(LOG_WARNING, "control setsockopt (TCP_NODELAY): %m");
 562
 563         data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
 564
 565         /* set this here so klogin can use it... */
 566         snprintf(ttyline, sizeof(ttyline), "ftp%d", getpid());
 567
 568         /* Try to handle urgent data inline */
 569 #ifdef SO_OOBINLINE
 570         if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) < 0)
 571                 syslog(LOG_WARNING, "control setsockopt (SO_OOBINLINE): %m");
 572 #endif
 573
 574 #ifdef  F_SETOWN
 575         if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
 576                 syslog(LOG_ERR, "fcntl F_SETOWN: %m");
 577 #endif
 578         dolog((struct sockaddr *)&his_addr);
 579         /*
 580          * Set up default state
 581          */
 582         data = -1;
 583         type = TYPE_A;
 584         form = FORM_N;
 585         stru = STRU_F;
 586         mode = MODE_S;
 587         tmpline[0] = '\0';
 588
 589         /* If logins are disabled, print out the message. */
 590         if ((fd = fopen(_PATH_NOLOGIN,"r")) != NULL) {
 591                 while (fgets(line, sizeof(line), fd) != NULL) {
 592                         if ((cp = strchr(line, '\n')) != NULL)
 593                                 *cp = '\0';
 594                         lreply(530, "%s", line);
 595                 }
 596                 fflush(stdout);
 597                 fclose(fd);
 598                 reply(530, "System not available.");
 599                 exit(0);
 600         }
 601 #ifdef VIRTUAL_HOSTING
 602         fd = fopen(thishost->welcome, "r");
 603 #else
 604         fd = fopen(_PATH_FTPWELCOME, "r");
 605 #endif
 606         if (fd != NULL) {
 607                 while (fgets(line, sizeof(line), fd) != NULL) {
 608                         if ((cp = strchr(line, '\n')) != NULL)
 609                                 *cp = '\0';
 610                         lreply(220, "%s", line);
 611                 }
 612                 fflush(stdout);
 613                 fclose(fd);
 614                 /* reply(220,) must follow */
 615         }
 616 #ifndef VIRTUAL_HOSTING
 617         if (hostname == NULL) {
 618                 if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
 619                         fatalerror("Ran out of memory.");
 620                 if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
 621                         hostname[0] = '\0';
 622                 hostname[MAXHOSTNAMELEN - 1] = '\0';
 623         }
 624 #endif
 625         if (hostinfo)
 626                 reply(220, "%s FTP server (%s) ready.", hostname, version);
 627         else
 628                 reply(220, "FTP server ready.");
 629         for (;;)
 630                 yyparse();
 631         /* NOTREACHED */
 632 }
 633
 634 static void
 635 lostconn(int signo)
 636 {
 637
 638         if (ftpdebug)
 639                 syslog(LOG_DEBUG, "lost connection");
 640         dologout(1);
 641 }
 642
 643 static void
 644 sigquit(int signo)
 645 {
 646
 647         syslog(LOG_ERR, "got signal %d", signo);
 648         dologout(1);
 649 }
 650
 651 #ifdef VIRTUAL_HOSTING
 652 /*
 653  * read in virtual host tables (if they exist)
 654  */
 655
 656 static void
 657 inithosts(int family)
 658 {
 659         int insert;
 660         size_t len;
 661         FILE *fp;
 662         char *cp, *mp, *line;
 663         char *vhost, *anonuser, *statfile, *welcome, *loginmsg;
 664         struct ftphost *hrp, *lhrp;
 665         struct addrinfo hints, *res, *ai;
 666
 667         /*
 668          * Fill in the default host information
 669          */
 670         if (hostname == NULL) {
 671                 if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
 672                         fatalerror("Ran out of memory.");
 673                 if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
 674                         hostname[0] = '\0';
 675                 hostname[MAXHOSTNAMELEN - 1] = '\0';
 676         }
 677         if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
 678                 fatalerror("Ran out of memory.");
 679         hrp->hostname = hostname;
 680         hrp->hostinfo = NULL;
 681
 682         memset(&hints, 0, sizeof(hints));
 683         hints.ai_flags = AI_PASSIVE;
 684         hints.ai_family = family;
 685         hints.ai_socktype = SOCK_STREAM;
 686         if (getaddrinfo(hrp->hostname, NULL, &hints, &res) == 0)
 687                 hrp->hostinfo = res;
 688         hrp->statfile = _PATH_FTPDSTATFILE;
 689         hrp->welcome  = _PATH_FTPWELCOME;
 690         hrp->loginmsg = _PATH_FTPLOGINMESG;
 691         hrp->anonuser = "ftp";
 692         hrp->next = NULL;
 693         thishost = firsthost = lhrp = hrp;
 694         if ((fp = fopen(_PATH_FTPHOSTS, "r")) != NULL) {
 695                 int addrsize, gothost;
 696                 void *addr;
 697                 struct hostent *hp;
 698
 699                 while ((line = fgetln(fp, &len)) != NULL) {
 700                         int     i, hp_error;
 701
 702                         /* skip comments */
 703                         if (line[0] == '#')
 704                                 continue;
 705                         if (line[len - 1] == '\n') {
 706                                 line[len - 1] = '\0';
 707                                 mp = NULL;
 708                         } else {
 709                                 if ((mp = malloc(len + 1)) == NULL)
 710                                         fatalerror("Ran out of memory.");
 711                                 memcpy(mp, line, len);
 712                                 mp[len] = '\0';
 713                                 line = mp;
 714                         }
 715                         cp = strtok(line, " \t");
 716                         /* skip empty lines */
 717                         if (cp == NULL)
 718                                 goto nextline;
 719                         vhost = cp;
 720
 721                         /* set defaults */
 722                         anonuser = "ftp";
 723                         statfile = _PATH_FTPDSTATFILE;
 724                         welcome  = _PATH_FTPWELCOME;
 725                         loginmsg = _PATH_FTPLOGINMESG;
 726
 727                         /*
 728                          * Preparse the line so we can use its info
 729                          * for all the addresses associated with
 730                          * the virtual host name.
 731                          * Field 0, the virtual host name, is special:
 732                          * it's already parsed off and will be strdup'ed
 733                          * later, after we know its canonical form.
 734                          */
 735                         for (i = 1; i < 5 && (cp = strtok(NULL, " \t")); i++)
 736                                 if (*cp != '-' && (cp = strdup(cp)))
 737                                         switch (i) {
 738                                         case 1: /* anon user permissions */
 739                                                 anonuser = cp;
 740                                                 break;
 741                                         case 2: /* statistics file */
 742                                                 statfile = cp;
 743                                                 break;
 744                                         case 3: /* welcome message */
 745                                                 welcome  = cp;
 746                                                 break;
 747                                         case 4: /* login message */
 748                                                 loginmsg = cp;
 749                                                 break;
 750                                         default: /* programming error */
 751                                                 abort();
 752                                                 /* NOTREACHED */
 753                                         }
 754
 755                         hints.ai_flags = AI_PASSIVE;
 756                         hints.ai_family = family;
 757                         hints.ai_socktype = SOCK_STREAM;
 758                         if (getaddrinfo(vhost, NULL, &hints, &res) != 0)
 759                                 goto nextline;
 760                         for (ai = res; ai != NULL && ai->ai_addr != NULL;
 761                              ai = ai->ai_next) {
 762
 763                         gothost = 0;
 764                         for (hrp = firsthost; hrp != NULL; hrp = hrp->next) {
 765                                 struct addrinfo *hi;
 766
 767                                 for (hi = hrp->hostinfo; hi != NULL;
 768                                      hi = hi->ai_next)
 769                                         if (hi->ai_addrlen == ai->ai_addrlen &&
 770                                             memcmp(hi->ai_addr,
 771                                                    ai->ai_addr,
 772                                                    ai->ai_addr->sa_len) == 0) {
 773                                                 gothost++;
 774                                                 break;
 775                                         }
 776                                 if (gothost)
 777                                         break;
 778                         }
 779                         if (hrp == NULL) {
 780                                 if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
 781                                         goto nextline;
 782                                 hrp->hostname = NULL;
 783                                 insert = 1;
 784                         } else {
 785                                 if (hrp->hostinfo && hrp->hostinfo != res)
 786                                         freeaddrinfo(hrp->hostinfo);
 787                                 insert = 0; /* host already in the chain */
 788                         }
 789                         hrp->hostinfo = res;
 790
 791                         /*
 792                          * determine hostname to use.
 793                          * force defined name if there is a valid alias
 794                          * otherwise fallback to primary hostname
 795                          */
 796                         /* XXX: getaddrinfo() can't do alias check */
 797                         switch(hrp->hostinfo->ai_family) {
 798                         case AF_INET:
 799                                 addr = &((struct sockaddr_in *)hrp->hostinfo->ai_addr)->sin_addr;
 800                                 addrsize = sizeof(struct in_addr);
 801                                 break;
 802                         case AF_INET6:
 803                                 addr = &((struct sockaddr_in6 *)hrp->hostinfo->ai_addr)->sin6_addr;
 804                                 addrsize = sizeof(struct in6_addr);
 805                                 break;
 806                         default:
 807                                 /* should not reach here */
 808                                 freeaddrinfo(hrp->hostinfo);
 809                                 if (insert)
 810                                         free(hrp); /*not in chain, can free*/
 811                                 else
 812                                         hrp->hostinfo = NULL; /*mark as blank*/
 813                                 goto nextline;
 814                                 /* NOTREACHED */
 815                         }
 816                         if ((hp = getipnodebyaddr(addr, addrsize,
 817                                                   hrp->hostinfo->ai_family,
 818                                                   &hp_error)) != NULL) {
 819                                 if (strcmp(vhost, hp->h_name) != 0) {
 820                                         if (hp->h_aliases == NULL)
 821                                                 vhost = hp->h_name;
 822                                         else {
 823                                                 i = 0;
 824                                                 while (hp->h_aliases[i] &&
 825                                                        strcmp(vhost, hp->h_aliases[i]) != 0)
 826                                                         ++i;
 827                                                 if (hp->h_aliases[i] == NULL)
 828                                                         vhost = hp->h_name;
 829                                         }
 830                                 }
 831                         }
 832                         if (hrp->hostname &&
 833                             strcmp(hrp->hostname, vhost) != 0) {
 834                                 free(hrp->hostname);
 835                                 hrp->hostname = NULL;
 836                         }
 837                         if (hrp->hostname == NULL &&
 838                             (hrp->hostname = strdup(vhost)) == NULL) {
 839                                 freeaddrinfo(hrp->hostinfo);
 840                                 hrp->hostinfo = NULL; /* mark as blank */
 841                                 if (hp)
 842                                         freehostent(hp);
 843                                 goto nextline;
 844                         }
 845                         hrp->anonuser = anonuser;
 846                         hrp->statfile = statfile;
 847                         hrp->welcome  = welcome;
 848                         hrp->loginmsg = loginmsg;
 849                         if (insert) {
 850                                 hrp->next  = NULL;
 851                                 lhrp->next = hrp;
 852                                 lhrp = hrp;
 853                         }
 854                         if (hp)
 855                                 freehostent(hp);
 856                       }
 857 nextline:
 858                         if (mp)
 859                                 free(mp);
 860                 }
 861                 fclose(fp);
 862         }
 863 }
 864
 865 static void
 866 selecthost(union sockunion *su)
 867 {
 868         struct ftphost  *hrp;
 869         u_int16_t port;
 870 #ifdef INET6
 871         struct in6_addr *mapped_in6 = NULL;
 872 #endif
 873         struct addrinfo *hi;
 874
 875 #ifdef INET6
 876         /*
 877          * XXX IPv4 mapped IPv6 addr consideraton,
 878          * specified in rfc2373.
 879          */
 880         if (su->su_family == AF_INET6 &&
 881             IN6_IS_ADDR_V4MAPPED(&su->su_sin6.sin6_addr))
 882                 mapped_in6 = &su->su_sin6.sin6_addr;
 883 #endif
 884
 885         hrp = thishost = firsthost;     /* default */
 886         port = su->su_port;
 887         su->su_port = 0;
 888         while (hrp != NULL) {
 889             for (hi = hrp->hostinfo; hi != NULL; hi = hi->ai_next) {
 890                 if (memcmp(su, hi->ai_addr, hi->ai_addrlen) == 0) {
 891                         thishost = hrp;
 892                         goto found;
 893                 }
 894 #ifdef INET6
 895                 /* XXX IPv4 mapped IPv6 addr consideraton */
 896                 if (hi->ai_addr->sa_family == AF_INET && mapped_in6 != NULL &&
 897                     (memcmp(&mapped_in6->s6_addr[12],
 898                             &((struct sockaddr_in *)hi->ai_addr)->sin_addr,
 899                             sizeof(struct in_addr)) == 0)) {
 900                         thishost = hrp;
 901                         goto found;
 902                 }
 903 #endif
 904             }
 905             hrp = hrp->next;
 906         }
 907 found:
 908         su->su_port = port;
 909         /* setup static variables as appropriate */
 910         hostname = thishost->hostname;
 911         ftpuser = thishost->anonuser;
 912 }
 913 #endif
 914
 915 /*
 916  * Helper function for sgetpwnam().
 917  */
 918 static char *
 919 sgetsave(char *s)
 920 {
 921         char *new = malloc(strlen(s) + 1);
 922
 923         if (new == NULL) {
 924                 reply(421, "Ran out of memory.");
 925                 dologout(1);
 926                 /* NOTREACHED */
 927         }
 928         strcpy(new, s);
 929         return (new);
 930 }
 931
 932 /*
 933  * Save the result of a getpwnam.  Used for USER command, since
 934  * the data returned must not be clobbered by any other command
 935  * (e.g., globbing).
 936  * NB: The data returned by sgetpwnam() will remain valid until
 937  * the next call to this function.  Its difference from getpwnam()
 938  * is that sgetpwnam() is known to be called from ftpd code only.
 939  */
 940 static struct passwd *
 941 sgetpwnam(char *name)
 942 {
 943         static struct passwd save;
 944         struct passwd *p;
 945
 946         if ((p = getpwnam(name)) == NULL)
 947                 return (p);
 948         if (save.pw_name) {
 949                 free(save.pw_name);
 950                 free(save.pw_passwd);
 951                 free(save.pw_gecos);
 952                 free(save.pw_dir);
 953                 free(save.pw_shell);
 954         }
 955         save = *p;
 956         save.pw_name = sgetsave(p->pw_name);
 957         save.pw_passwd = sgetsave(p->pw_passwd);
 958         save.pw_gecos = sgetsave(p->pw_gecos);
 959         save.pw_dir = sgetsave(p->pw_dir);
 960         save.pw_shell = sgetsave(p->pw_shell);
 961         return (&save);
 962 }
 963
 964 static int login_attempts;      /* number of failed login attempts */
 965 static int askpasswd;           /* had user command, ask for passwd */
 966 static char curname[MAXLOGNAME];        /* current USER name */
 967
 968 /*
 969  * USER command.
 970  * Sets global passwd pointer pw if named account exists and is acceptable;
 971  * sets askpasswd if a PASS command is expected.  If logged in previously,
 972  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
 973  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
 974  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
 975  * requesting login privileges.  Disallow anyone who does not have a standard
 976  * shell as returned by getusershell().  Disallow anyone mentioned in the file
 977  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
 978  */
 979 void
 980 user(char *name)
 981 {
 982         char *cp, *shell;
 983
 984         if (logged_in) {
 985                 if (guest) {
 986                         reply(530, "Can't change user from guest login.");
 987                         return;
 988                 } else if (dochroot) {
 989                         reply(530, "Can't change user from chroot user.");
 990                         return;
 991                 }
 992                 end_login();
 993         }
 994
 995         guest = 0;
 996 #ifdef VIRTUAL_HOSTING
 997         pw = sgetpwnam(thishost->anonuser);
 998 #else
 999         pw = sgetpwnam("ftp");
1000 #endif
1001         if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
1002                 if (checkuser(_PATH_FTPUSERS, "ftp", 0, NULL) ||
1003                     checkuser(_PATH_FTPUSERS, "anonymous", 0, NULL))
1004                         reply(530, "User %s access denied.", name);
1005                 else if (pw != NULL) {
1006                         guest = 1;
1007                         askpasswd = 1;
1008                         reply(331,
1009                         "Guest login ok, send your email address as password.");
1010                 } else
1011                         reply(530, "User %s unknown.", name);
1012                 if (!askpasswd && logging)
1013                         syslog(LOG_NOTICE,
1014                             "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
1015                 return;
1016         }
1017         if (anon_only != 0) {
1018                 reply(530, "Sorry, only anonymous ftp allowed.");
1019                 return;
1020         }
1021
1022         if ((pw = sgetpwnam(name))) {
1023                 if ((shell = pw->pw_shell) == NULL || *shell == 0)
1024                         shell = _PATH_BSHELL;
1025                 setusershell();
1026                 while ((cp = getusershell()) != NULL)
1027                         if (strcmp(cp, shell) == 0)
1028                                 break;
1029                 endusershell();
1030
1031                 if (cp == NULL || checkuser(_PATH_FTPUSERS, name, 1, NULL)) {
1032                         reply(530, "User %s access denied.", name);
1033                         if (logging)
1034                                 syslog(LOG_NOTICE,
1035                                     "FTP LOGIN REFUSED FROM %s, %s",
1036                                     remotehost, name);
1037                         pw = NULL;
1038                         return;
1039                 }
1040         }
1041         if (logging)
1042                 strncpy(curname, name, sizeof(curname)-1);
1043
1044         pwok = 0;
1045 #ifdef OPIE
1046 #ifdef USE_PAM
1047         /* XXX Kluge! The conversation mechanism needs to be fixed. */
1048 #endif
1049         if (opiechallenge(&opiedata, name, opieprompt) == 0) {
1050                 pwok = (pw != NULL) &&
1051                        opieaccessfile(remotehost) &&
1052                        opiealways(pw->pw_dir);
1053                 reply(331, "Response to %s %s for %s.",
1054                       opieprompt, pwok ? "requested" : "required", name);
1055         } else {
1056                 pwok = 1;
1057                 reply(331, "Password required for %s.", name);
1058         }
1059 #else
1060         pwok = 1;
1061         reply(331, "Password required for %s.", name);
1062 #endif
1063         askpasswd = 1;
1064         /*
1065          * Delay before reading passwd after first failed
1066          * attempt to slow down passwd-guessing programs.
1067          */
1068         if (login_attempts)
1069                 sleep(login_attempts);
1070 }
1071
1072 /*
1073  * Check if a user is in the file "fname",
1074  * return a pointer to a malloc'd string with the rest
1075  * of the matching line in "residue" if not NULL.
1076  */
1077 static int
1078 checkuser(char *fname, char *name, int pwset, char **residue)
1079 {
1080         FILE *fd;
1081         int found = 0;
1082         size_t len;
1083         char *line, *mp, *p;
1084
1085         if ((fd = fopen(fname, "r")) != NULL) {
1086                 while (!found && (line = fgetln(fd, &len)) != NULL) {
1087                         /* skip comments */
1088                         if (line[0] == '#')
1089                                 continue;
1090                         if (line[len - 1] == '\n') {
1091                                 line[len - 1] = '\0';
1092                                 mp = NULL;
1093                         } else {
1094                                 if ((mp = malloc(len + 1)) == NULL)
1095                                         fatalerror("Ran out of memory.");
1096                                 memcpy(mp, line, len);
1097                                 mp[len] = '\0';
1098                                 line = mp;
1099                         }
1100                         /* avoid possible leading and trailing whitespace */
1101                         p = strtok(line, " \t");
1102                         /* skip empty lines */
1103                         if (p == NULL)
1104                                 goto nextline;
1105                         /*
1106                          * if first chr is '@', check group membership
1107                          */
1108                         if (p[0] == '@') {
1109                                 int i = 0;
1110                                 struct group *grp;
1111
1112                                 if (p[1] == '\0') /* single @ matches anyone */
1113                                         found = 1;
1114                                 else {
1115                                         if ((grp = getgrnam(p+1)) == NULL)
1116                                                 goto nextline;
1117                                         /*
1118                                          * Check user's default group
1119                                          */
1120                                         if (pwset && grp->gr_gid == pw->pw_gid)
1121                                                 found = 1;
1122                                         /*
1123                                          * Check supplementary groups
1124                                          */
1125                                         while (!found && grp->gr_mem[i])
1126                                                 found = strcmp(name,
1127                                                         grp->gr_mem[i++])
1128                                                         == 0;
1129                                 }
1130                         }
1131                         /*
1132                          * Otherwise, just check for username match
1133                          */
1134                         else
1135                                 found = strcmp(p, name) == 0;
1136                         /*
1137                          * Save the rest of line to "residue" if matched
1138                          */
1139                         if (found && residue) {
1140                                 if ((p = strtok(NULL, "")) != NULL)
1141                                         p += strspn(p, " \t");
1142                                 if (p && *p) {
1143                                         if ((*residue = strdup(p)) == NULL)
1144                                                 fatalerror("Ran out of memory.");
1145                                 } else
1146                                         *residue = NULL;
1147                         }
1148 nextline:
1149                         if (mp)
1150                                 free(mp);
1151                 }
1152                 fclose(fd);
1153         }
1154         return (found);
1155 }
1156
1157 /*
1158  * Terminate login as previous user, if any, resetting state;
1159  * used when USER command is given or login fails.
1160  */
1161 static void
1162 end_login(void)
1163 {
1164 #ifdef USE_PAM
1165         int e;
1166 #endif
1167
1168         seteuid(0);
1169         if (logged_in && dowtmp)
1170                 ftpd_logwtmp(ttyline, "", NULL);
1171         pw = NULL;
1172 #ifdef  LOGIN_CAP
1173         /* XXX Missing LOGIN_SETMAC */
1174         setusercontext(NULL, getpwuid(0), 0,
1175                        LOGIN_SETPRIORITY|LOGIN_SETRESOURCES|LOGIN_SETUMASK);
1176 #endif
1177 #ifdef USE_PAM
1178         if (pamh) {
1179                 if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS)
1180                         syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1181                 if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS)
1182                         syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e));
1183                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS)
1184                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1185                 pamh = NULL;
1186         }
1187 #endif
1188         logged_in = 0;
1189         guest = 0;
1190         dochroot = 0;
1191 }
1192
1193 #ifdef USE_PAM
1194
1195 /*
1196  * the following code is stolen from imap-uw PAM authentication module and
1197  * login.c
1198  */
1199 #define COPY_STRING(s) (s ? strdup(s) : NULL)
1200
1201 struct cred_t {
1202         const char *uname;              /* user name */
1203         const char *pass;               /* password */
1204 };
1205 typedef struct cred_t cred_t;
1206
1207 static int
1208 auth_conv(int num_msg, const struct pam_message **msg,
1209           struct pam_response **resp, void *appdata)
1210 {
1211         int i;
1212         cred_t *cred = (cred_t *) appdata;
1213         struct pam_response *reply;
1214
1215         reply = calloc(num_msg, sizeof *reply);
1216         if (reply == NULL)
1217                 return PAM_BUF_ERR;
1218
1219         for (i = 0; i < num_msg; i++) {
1220                 switch (msg[i]->msg_style) {
1221                 case PAM_PROMPT_ECHO_ON:        /* assume want user name */
1222                         reply[i].resp_retcode = PAM_SUCCESS;
1223                         reply[i].resp = COPY_STRING(cred->uname);
1224                         /* PAM frees resp. */
1225                         break;
1226                 case PAM_PROMPT_ECHO_OFF:       /* assume want password */
1227                         reply[i].resp_retcode = PAM_SUCCESS;
1228                         reply[i].resp = COPY_STRING(cred->pass);
1229                         /* PAM frees resp. */
1230                         break;
1231                 case PAM_TEXT_INFO:
1232                 case PAM_ERROR_MSG:
1233                         reply[i].resp_retcode = PAM_SUCCESS;
1234                         reply[i].resp = NULL;
1235                         break;
1236                 default:                        /* unknown message style */
1237                         free(reply);
1238                         return PAM_CONV_ERR;
1239                 }
1240         }
1241
1242         *resp = reply;
1243         return PAM_SUCCESS;
1244 }
1245
1246 /*
1247  * Attempt to authenticate the user using PAM.  Returns 0 if the user is
1248  * authenticated, or 1 if not authenticated.  If some sort of PAM system
1249  * error occurs (e.g., the "/etc/pam.conf" file is missing) then this
1250  * function returns -1.  This can be used as an indication that we should
1251  * fall back to a different authentication mechanism.
1252  */
1253 static int
1254 auth_pam(struct passwd **ppw, const char *pass)
1255 {
1256         const char *tmpl_user;
1257         const void *item;
1258         int rval;
1259         int e;
1260         cred_t auth_cred = { (*ppw)->pw_name, pass };
1261         struct pam_conv conv = { &auth_conv, &auth_cred };
1262
1263         e = pam_start("ftpd", (*ppw)->pw_name, &conv, &pamh);
1264         if (e != PAM_SUCCESS) {
1265                 /*
1266                  * In OpenPAM, it's OK to pass NULL to pam_strerror()
1267                  * if context creation has failed in the first place.
1268                  */
1269                 syslog(LOG_ERR, "pam_start: %s", pam_strerror(NULL, e));
1270                 return -1;
1271         }
1272
1273         e = pam_set_item(pamh, PAM_RHOST, remotehost);
1274         if (e != PAM_SUCCESS) {
1275                 syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
1276                         pam_strerror(pamh, e));
1277                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1278                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1279                 }
1280                 pamh = NULL;
1281                 return -1;
1282         }
1283
1284         e = pam_authenticate(pamh, 0);
1285         switch (e) {
1286         case PAM_SUCCESS:
1287                 /*
1288                  * With PAM we support the concept of a "template"
1289                  * user.  The user enters a login name which is
1290                  * authenticated by PAM, usually via a remote service
1291                  * such as RADIUS or TACACS+.  If authentication
1292                  * succeeds, a different but related "template" name
1293                  * is used for setting the credentials, shell, and
1294                  * home directory.  The name the user enters need only
1295                  * exist on the remote authentication server, but the
1296                  * template name must be present in the local password
1297                  * database.
1298                  *
1299                  * This is supported by two various mechanisms in the
1300                  * individual modules.  However, from the application's
1301                  * point of view, the template user is always passed
1302                  * back as a changed value of the PAM_USER item.
1303                  */
1304                 if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
1305                     PAM_SUCCESS) {
1306                         tmpl_user = (const char *) item;
1307                         if (strcmp((*ppw)->pw_name, tmpl_user) != 0)
1308                                 *ppw = getpwnam(tmpl_user);
1309                 } else
1310                         syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
1311                             pam_strerror(pamh, e));
1312                 rval = 0;
1313                 break;
1314
1315         case PAM_AUTH_ERR:
1316         case PAM_USER_UNKNOWN:
1317         case PAM_MAXTRIES:
1318                 rval = 1;
1319                 break;
1320
1321         default:
1322                 syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e));
1323                 rval = -1;
1324                 break;
1325         }
1326
1327         if (rval == 0) {
1328                 e = pam_acct_mgmt(pamh, 0);
1329                 if (e != PAM_SUCCESS) {
1330                         syslog(LOG_ERR, "pam_acct_mgmt: %s",
1331                                                 pam_strerror(pamh, e));
1332                         rval = 1;
1333                 }
1334         }
1335
1336         if (rval != 0) {
1337                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1338                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1339                 }
1340                 pamh = NULL;
1341         }
1342         return rval;
1343 }
1344
1345 #endif /* USE_PAM */
1346
1347 void
1348 pass(char *passwd)
1349 {
1350         int rval;
1351         FILE *fd;
1352 #ifdef  LOGIN_CAP
1353         login_cap_t *lc = NULL;
1354 #endif
1355 #ifdef USE_PAM
1356         int e;
1357 #endif
1358         char *residue = NULL;
1359         char *xpasswd;
1360
1361         if (logged_in || askpasswd == 0) {
1362                 reply(503, "Login with USER first.");
1363                 return;
1364         }
1365         askpasswd = 0;
1366         if (!guest) {           /* "ftp" is only account allowed no password */
1367                 if (pw == NULL) {
1368                         rval = 1;       /* failure below */
1369                         goto skip;
1370                 }
1371 #ifdef USE_PAM
1372                 rval = auth_pam(&pw, passwd);
1373                 if (rval >= 0) {
1374 #ifdef OPIE
1375                         opieunlock();
1376 #endif
1377                         goto skip;
1378                 }
1379 #endif
1380 #ifdef OPIE
1381                 if (opieverify(&opiedata, passwd) == 0)
1382                         xpasswd = pw->pw_passwd;
1383                 else
1384 #endif
1385                 if (pwok) {
1386                         xpasswd = crypt(passwd, pw->pw_passwd);
1387                         if (passwd[0] == '\0' && pw->pw_passwd[0] != '\0')
1388                                 xpasswd = ":";
1389                 } else {
1390                         rval = 1;
1391                         goto skip;
1392                 }
1393                 rval = strcmp(pw->pw_passwd, xpasswd);
1394                 if (pw->pw_expire && time(NULL) >= pw->pw_expire)
1395                         rval = 1;       /* failure */
1396 skip:
1397                 /*
1398                  * If rval == 1, the user failed the authentication check
1399                  * above.  If rval == 0, either PAM or local authentication
1400                  * succeeded.
1401                  */
1402                 if (rval) {
1403                         reply(530, "Login incorrect.");
1404                         if (logging) {
1405                                 syslog(LOG_NOTICE,
1406                                     "FTP LOGIN FAILED FROM %s",
1407                                     remotehost);
1408                                 syslog(LOG_AUTHPRIV | LOG_NOTICE,
1409                                     "FTP LOGIN FAILED FROM %s, %s",
1410                                     remotehost, curname);
1411                         }
1412                         pw = NULL;
1413                         if (login_attempts++ >= 5) {
1414                                 syslog(LOG_NOTICE,
1415                                     "repeated login failures from %s",
1416                                     remotehost);
1417                                 exit(0);
1418                         }
1419                         return;
1420                 }
1421         }
1422         login_attempts = 0;             /* this time successful */
1423         if (setegid(pw->pw_gid) < 0) {
1424                 reply(550, "Can't set gid.");
1425                 return;
1426         }
1427         /* May be overridden by login.conf */
1428         umask(defumask);
1429 #ifdef  LOGIN_CAP
1430         if ((lc = login_getpwclass(pw)) != NULL) {
1431                 char    remote_ip[NI_MAXHOST];
1432
1433                 if (getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1434                         remote_ip, sizeof(remote_ip) - 1, NULL, 0,
1435                         NI_NUMERICHOST))
1436                                 *remote_ip = 0;
1437                 remote_ip[sizeof(remote_ip) - 1] = 0;
1438                 if (!auth_hostok(lc, remotehost, remote_ip)) {
1439                         syslog(LOG_INFO|LOG_AUTH,
1440                             "FTP LOGIN FAILED (HOST) as %s: permission denied.",
1441                             pw->pw_name);
1442                         reply(530, "Permission denied.");
1443                         pw = NULL;
1444                         return;
1445                 }
1446                 if (!auth_timeok(lc, time(NULL))) {
1447                         reply(530, "Login not available right now.");
1448                         pw = NULL;
1449                         return;
1450                 }
1451         }
1452         /* XXX Missing LOGIN_SETMAC */
1453         setusercontext(lc, pw, 0,
1454                 LOGIN_SETLOGIN|LOGIN_SETGROUP|LOGIN_SETPRIORITY|
1455                 LOGIN_SETRESOURCES|LOGIN_SETUMASK);
1456 #else
1457         setlogin(pw->pw_name);
1458         initgroups(pw->pw_name, pw->pw_gid);
1459 #endif
1460
1461 #ifdef USE_PAM
1462         if (pamh) {
1463                 if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
1464                         syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, e));
1465                 } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
1466                         syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1467                 }
1468         }
1469 #endif
1470
1471         /* open wtmp before chroot */
1472         if (dowtmp)
1473                 ftpd_logwtmp(ttyline, pw->pw_name,
1474                     (struct sockaddr *)&his_addr);
1475         logged_in = 1;
1476
1477         if (guest && stats && statfd < 0)
1478 #ifdef VIRTUAL_HOSTING
1479                 statfd = open(thishost->statfile, O_WRONLY|O_APPEND);
1480 #else
1481                 statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND);
1482 #endif
1483                 if (statfd < 0)
1484                         stats = 0;
1485
1486         dochroot =
1487                 checkuser(_PATH_FTPCHROOT, pw->pw_name, 1, &residue)
1488 #ifdef  LOGIN_CAP       /* Allow login.conf configuration as well */
1489                 || login_getcapbool(lc, "ftp-chroot", 0)
1490 #endif
1491         ;
1492         chrootdir = NULL;
1493         /*
1494          * For a chrooted local user,
1495          * a) see whether ftpchroot(5) specifies a chroot directory,
1496          * b) extract the directory pathname from the line,
1497          * c) expand it to the absolute pathname if necessary.
1498          */
1499         if (dochroot && residue &&
1500             (chrootdir = strtok(residue, " \t")) != NULL) {
1501                 if (chrootdir[0] != '/')
1502                         asprintf(&chrootdir, "%s/%s", pw->pw_dir, chrootdir);
1503                 else
1504                         chrootdir = strdup(chrootdir); /* make it permanent */
1505                 if (chrootdir == NULL)
1506                         fatalerror("Ran out of memory.");
1507         }
1508         if (guest || dochroot) {
1509                 /*
1510                  * If no chroot directory set yet, use the login directory.
1511                  * Copy it so it can be modified while pw->pw_dir stays intact.
1512                  */
1513                 if (chrootdir == NULL &&
1514                     (chrootdir = strdup(pw->pw_dir)) == NULL)
1515                         fatalerror("Ran out of memory.");
1516                 /*
1517                  * Check for the "/chroot/./home" syntax,
1518                  * separate the chroot and home directory pathnames.
1519                  */
1520                 if ((homedir = strstr(chrootdir, "/./")) != NULL) {
1521                         *(homedir++) = '\0';    /* wipe '/' */
1522                         homedir++;              /* skip '.' */
1523                 } else {
1524                         /*
1525                          * We MUST do a chdir() after the chroot. Otherwise
1526                          * the old current directory will be accessible as "."
1527                          * outside the new root!
1528                          */
1529                         homedir = "/";
1530                 }
1531                 /*
1532                  * Finally, do chroot()
1533                  */
1534                 if (chroot(chrootdir) < 0) {
1535                         reply(550, "Can't change root.");
1536                         goto bad;
1537                 }
1538         } else  /* real user w/o chroot */
1539                 homedir = pw->pw_dir;
1540         /*
1541          * Set euid *before* doing chdir() so
1542          * a) the user won't be carried to a directory that he couldn't reach
1543          *    on his own due to no permission to upper path components,
1544          * b) NFS mounted homedirs w/restrictive permissions will be accessible
1545          *    (uid 0 has no root power over NFS if not mapped explicitly.)
1546          */
1547         if (seteuid(pw->pw_uid) < 0) {
1548                 reply(550, "Can't set uid.");
1549                 goto bad;
1550         }
1551         if (chdir(homedir) < 0) {
1552                 if (guest || dochroot) {
1553                         reply(550, "Can't change to base directory.");
1554                         goto bad;
1555                 } else {
1556                         if (chdir("/") < 0) {
1557                                 reply(550, "Root is inaccessible.");
1558                                 goto bad;
1559                         }
1560                         lreply(230, "No directory! Logging in with home=/.");
1561                 }
1562         }
1563
1564         /*
1565          * Display a login message, if it exists.
1566          * N.B. reply(230,) must follow the message.
1567          */
1568 #ifdef VIRTUAL_HOSTING
1569         fd = fopen(thishost->loginmsg, "r");
1570 #else
1571         fd = fopen(_PATH_FTPLOGINMESG, "r");
1572 #endif
1573         if (fd != NULL) {
1574                 char *cp, line[LINE_MAX];
1575
1576                 while (fgets(line, sizeof(line), fd) != NULL) {
1577                         if ((cp = strchr(line, '\n')) != NULL)
1578                                 *cp = '\0';
1579                         lreply(230, "%s", line);
1580                 }
1581                 fflush(stdout);
1582                 fclose(fd);
1583         }
1584         if (guest) {
1585                 if (ident != NULL)
1586                         free(ident);
1587                 ident = strdup(passwd);
1588                 if (ident == NULL)
1589                         fatalerror("Ran out of memory.");
1590
1591                 reply(230, "Guest login ok, access restrictions apply.");
1592 #ifdef SETPROCTITLE
1593 #ifdef VIRTUAL_HOSTING
1594                 if (thishost != firsthost)
1595                         snprintf(proctitle, sizeof(proctitle),
1596                                  "%s: anonymous(%s)/%s", remotehost, hostname,
1597                                  passwd);
1598                 else
1599 #endif
1600                         snprintf(proctitle, sizeof(proctitle),
1601                                  "%s: anonymous/%s", remotehost, passwd);
1602                 setproctitle("%s", proctitle);
1603 #endif /* SETPROCTITLE */
1604                 if (logging)
1605                         syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1606                             remotehost, passwd);
1607         } else {
1608                 if (dochroot)
1609                         reply(230, "User %s logged in, "
1610                                    "access restrictions apply.", pw->pw_name);
1611                 else
1612                         reply(230, "User %s logged in.", pw->pw_name);
1613
1614 #ifdef SETPROCTITLE
1615                 snprintf(proctitle, sizeof(proctitle),
1616                          "%s: user/%s", remotehost, pw->pw_name);
1617                 setproctitle("%s", proctitle);
1618 #endif /* SETPROCTITLE */
1619                 if (logging)
1620                         syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1621                             remotehost, pw->pw_name);
1622         }
1623         if (logging && (guest || dochroot))
1624                 syslog(LOG_INFO, "session root changed to %s", chrootdir);
1625 #ifdef  LOGIN_CAP
1626         login_close(lc);
1627 #endif
1628         if (residue)
1629                 free(residue);
1630         return;
1631 bad:
1632         /* Forget all about it... */
1633 #ifdef  LOGIN_CAP
1634         login_close(lc);
1635 #endif
1636         if (residue)
1637                 free(residue);
1638         end_login();
1639 }
1640
1641 void
1642 retrieve(char *cmd, char *name)
1643 {
1644         FILE *fin, *dout;
1645         struct stat st;
1646         int (*closefunc)(FILE *);
1647         time_t start;
1648
1649         if (cmd == NULL) {
1650                 fin = fopen(name, "r"), closefunc = fclose;
1651                 st.st_size = 0;
1652         } else {
1653                 char line[BUFSIZ];
1654
1655                 snprintf(line, sizeof(line), cmd, name), name = line;
1656                 fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1657                 st.st_size = -1;
1658                 st.st_blksize = BUFSIZ;
1659         }
1660         if (fin == NULL) {
1661                 if (errno != 0) {
1662                         perror_reply(550, name);
1663                         if (cmd == NULL) {
1664                                 LOGCMD("get", name);
1665                         }
1666                 }
1667                 return;
1668         }
1669         byte_count = -1;
1670         if (cmd == NULL) {
1671                 if (fstat(fileno(fin), &st) < 0) {
1672                         perror_reply(550, name);
1673                         goto done;
1674                 }
1675                 if (!S_ISREG(st.st_mode)) {
1676                         /*
1677                          * Never sending a raw directory is a workaround
1678                          * for buggy clients that will attempt to RETR
1679                          * a directory before listing it, e.g., Mozilla.
1680                          * Preventing a guest from getting irregular files
1681                          * is a simple security measure.
1682                          */
1683                         if (S_ISDIR(st.st_mode) || guest) {
1684                                 reply(550, "%s: not a plain file.", name);
1685                                 goto done;
1686                         }
1687                         st.st_size = -1;
1688                         /* st.st_blksize is set for all descriptor types */
1689                 }
1690         }
1691         if (restart_point) {
1692                 if (type == TYPE_A) {
1693                         off_t i, n;
1694                         int c;
1695
1696                         n = restart_point;
1697                         i = 0;
1698                         while (i++ < n) {
1699                                 if ((c=getc(fin)) == EOF) {
1700                                         perror_reply(550, name);
1701                                         goto done;
1702                                 }
1703                                 if (c == '\n')
1704                                         i++;
1705                         }
1706                 } else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
1707                         perror_reply(550, name);
1708                         goto done;
1709                 }
1710         }
1711         dout = dataconn(name, st.st_size, "w");
1712         if (dout == NULL)
1713                 goto done;
1714         time(&start);
1715         send_data(fin, dout, st.st_blksize, st.st_size,
1716                   restart_point == 0 && cmd == NULL && S_ISREG(st.st_mode));
1717         if (cmd == NULL && guest && stats && byte_count > 0)
1718                 logxfer(name, byte_count, start);
1719         fclose(dout);
1720         data = -1;
1721         pdata = -1;
1722 done:
1723         if (cmd == NULL)
1724                 LOGBYTES("get", name, byte_count);
1725         (*closefunc)(fin);
1726 }
1727
1728 void
1729 store(char *name, char *mode, int unique)
1730 {
1731         int fd;
1732         FILE *fout, *din;
1733         int (*closefunc)(FILE *);
1734
1735         if (*mode == 'a') {             /* APPE */
1736                 if (unique) {
1737                         /* Programming error */
1738                         syslog(LOG_ERR, "Internal: unique flag to APPE");
1739                         unique = 0;
1740                 }
1741                 if (guest && noguestmod) {
1742                         reply(550, "Appending to existing file denied.");
1743                         goto err;
1744                 }
1745                 restart_point = 0;      /* not affected by preceding REST */
1746         }
1747         if (unique)                     /* STOU overrides REST */
1748                 restart_point = 0;
1749         if (guest && noguestmod) {
1750                 if (restart_point) {    /* guest STOR w/REST */
1751                         reply(550, "Modifying existing file denied.");
1752                         goto err;
1753                 } else                  /* treat guest STOR as STOU */
1754                         unique = 1;
1755         }
1756
1757         if (restart_point)
1758                 mode = "r+";    /* so ASCII manual seek can work */
1759         if (unique) {
1760                 if ((fd = guniquefd(name, &name)) < 0)
1761                         goto err;
1762                 fout = fdopen(fd, mode);
1763         } else
1764                 fout = fopen(name, mode);
1765         closefunc = fclose;
1766         if (fout == NULL) {
1767                 perror_reply(553, name);
1768                 goto err;
1769         }
1770         byte_count = -1;
1771         if (restart_point) {
1772                 if (type == TYPE_A) {
1773                         off_t i, n;
1774                         int c;
1775
1776                         n = restart_point;
1777                         i = 0;
1778                         while (i++ < n) {
1779                                 if ((c=getc(fout)) == EOF) {
1780                                         perror_reply(550, name);
1781                                         goto done;
1782                                 }
1783                                 if (c == '\n')
1784                                         i++;
1785                         }
1786                         /*
1787                          * We must do this seek to "current" position
1788                          * because we are changing from reading to
1789                          * writing.
1790                          */
1791                         if (fseeko(fout, 0, SEEK_CUR) < 0) {
1792                                 perror_reply(550, name);
1793                                 goto done;
1794                         }
1795                 } else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
1796                         perror_reply(550, name);
1797                         goto done;
1798                 }
1799         }
1800         din = dataconn(name, -1, "r");
1801         if (din == NULL)
1802                 goto done;
1803         if (receive_data(din, fout) == 0) {
1804                 if (unique)
1805                         reply(226, "Transfer complete (unique file name:%s).",
1806                             name);
1807                 else
1808                         reply(226, "Transfer complete.");
1809         }
1810         fclose(din);
1811         data = -1;
1812         pdata = -1;
1813 done:
1814         LOGBYTES(*mode == 'a' ? "append" : "put", name, byte_count);
1815         (*closefunc)(fout);
1816         return;
1817 err:
1818         LOGCMD(*mode == 'a' ? "append" : "put" , name);
1819         return;
1820 }
1821
1822 static FILE *
1823 getdatasock(char *mode)
1824 {
1825         int on = 1, s, t, tries;
1826
1827         if (data >= 0)
1828                 return (fdopen(data, mode));
1829
1830         s = socket(data_dest.su_family, SOCK_STREAM, 0);
1831         if (s < 0)
1832                 goto bad;
1833         if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
1834                 syslog(LOG_WARNING, "data setsockopt (SO_REUSEADDR): %m");
1835         /* anchor socket to avoid multi-homing problems */
1836         data_source = ctrl_addr;
1837         data_source.su_port = htons(dataport);
1838         seteuid(0);
1839         for (tries = 1; ; tries++) {
1840                 /*
1841                  * We should loop here since it's possible that
1842                  * another ftpd instance has passed this point and is
1843                  * trying to open a data connection in active mode now.
1844                  * Until the other connection is opened, we'll be getting
1845                  * EADDRINUSE because no SOCK_STREAM sockets in the system
1846                  * can share both local and remote addresses, localIP:20
1847                  * and *:* in this case.
1848                  */
1849                 if (bind(s, (struct sockaddr *)&data_source,
1850                     data_source.su_len) >= 0)
1851                         break;
1852                 if (errno != EADDRINUSE || tries > 10)
1853                         goto bad;
1854                 sleep(tries);
1855         }
1856         seteuid(pw->pw_uid);
1857 #ifdef IP_TOS
1858         if (data_source.su_family == AF_INET)
1859       {
1860         on = IPTOS_THROUGHPUT;
1861         if (setsockopt(s, IPPROTO_IP, IP_TOS, &on, sizeof(int)) < 0)
1862                 syslog(LOG_WARNING, "data setsockopt (IP_TOS): %m");
1863       }
1864 #endif
1865 #ifdef TCP_NOPUSH
1866         /*
1867          * Turn off push flag to keep sender TCP from sending short packets
1868          * at the boundaries of each write().
1869          */
1870         on = 1;
1871         if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof on) < 0)
1872                 syslog(LOG_WARNING, "data setsockopt (TCP_NOPUSH): %m");
1873 #endif
1874         return (fdopen(s, mode));
1875 bad:
1876         /* Return the real value of errno (close may change it) */
1877         t = errno;
1878         seteuid(pw->pw_uid);
1879         close(s);
1880         errno = t;
1881         return (NULL);
1882 }
1883
1884 static FILE *
1885 dataconn(char *name, off_t size, char *mode)
1886 {
1887         char sizebuf[32];
1888         FILE *file;
1889         int retry = 0, tos, conerrno;
1890
1891         file_size = size;
1892         byte_count = 0;
1893         if (size != -1)
1894                 snprintf(sizebuf, sizeof(sizebuf),
1895                                 " (%jd bytes)", (intmax_t)size);
1896         else
1897                 *sizebuf = '\0';
1898         if (pdata >= 0) {
1899                 union sockunion from;
1900                 socklen_t fromlen = ctrl_addr.su_len;
1901                 int flags, s;
1902                 struct timeval timeout;
1903                 fd_set set;
1904
1905                 FD_ZERO(&set);
1906                 FD_SET(pdata, &set);
1907
1908                 timeout.tv_usec = 0;
1909                 timeout.tv_sec = 120;
1910
1911                 /*
1912                  * Granted a socket is in the blocking I/O mode,
1913                  * accept() will block after a successful select()
1914                  * if the selected connection dies in between.
1915                  * Therefore set the non-blocking I/O flag here.
1916                  */
1917                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1918                     fcntl(pdata, F_SETFL, flags | O_NONBLOCK) == -1)
1919                         goto pdata_err;
1920                 if (select(pdata+1, &set, NULL, NULL, &timeout) <= 0 ||
1921                     (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0)
1922                         goto pdata_err;
1923                 close(pdata);
1924                 pdata = s;
1925                 /*
1926                  * Unset the inherited non-blocking I/O flag
1927                  * on the child socket so stdio can work on it.
1928                  */
1929                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1930                     fcntl(pdata, F_SETFL, flags & ~O_NONBLOCK) == -1)
1931                         goto pdata_err;
1932 #ifdef IP_TOS
1933                 if (from.su_family == AF_INET)
1934               {
1935                 tos = IPTOS_THROUGHPUT;
1936                 if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
1937                         syslog(LOG_WARNING, "pdata setsockopt (IP_TOS): %m");
1938               }
1939 #endif
1940                 reply(150, "Opening %s mode data connection for '%s'%s.",
1941                      type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1942                 return (fdopen(pdata, mode));
1943 pdata_err:
1944                 reply(425, "Can't open data connection.");
1945                 close(pdata);
1946                 pdata = -1;
1947                 return (NULL);
1948         }
1949         if (data >= 0) {
1950                 reply(125, "Using existing data connection for '%s'%s.",
1951                     name, sizebuf);
1952                 usedefault = 1;
1953                 return (fdopen(data, mode));
1954         }
1955         if (usedefault)
1956                 data_dest = his_addr;
1957         usedefault = 1;
1958         do {
1959                 file = getdatasock(mode);
1960                 if (file == NULL) {
1961                         char hostbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
1962
1963                         if (getnameinfo((struct sockaddr *)&data_source,
1964                                 data_source.su_len,
1965                                 hostbuf, sizeof(hostbuf) - 1,
1966                                 portbuf, sizeof(portbuf) - 1,
1967                                 NI_NUMERICHOST|NI_NUMERICSERV))
1968                                         *hostbuf = *portbuf = 0;
1969                         hostbuf[sizeof(hostbuf) - 1] = 0;
1970                         portbuf[sizeof(portbuf) - 1] = 0;
1971                         reply(425, "Can't create data socket (%s,%s): %s.",
1972                                 hostbuf, portbuf, strerror(errno));
1973                         return (NULL);
1974                 }
1975                 data = fileno(file);
1976                 conerrno = 0;
1977                 if (connect(data, (struct sockaddr *)&data_dest,
1978                     data_dest.su_len) == 0)
1979                         break;
1980                 conerrno = errno;
1981                 fclose(file);
1982                 data = -1;
1983                 if (conerrno == EADDRINUSE) {
1984                         sleep(swaitint);
1985                         retry += swaitint;
1986                 } else {
1987                         break;
1988                 }
1989         } while (retry <= swaitmax);
1990         if (conerrno != 0) {
1991                 reply(425, "Can't build data connection: %s.",
1992                            strerror(conerrno));
1993                 return (NULL);
1994         }
1995         reply(150, "Opening %s mode data connection for '%s'%s.",
1996              type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1997         return (file);
1998 }
1999
2000 /*
2001  * A helper macro to avoid code duplication
2002  * in send_data() and receive_data().
2003  *
2004  * XXX We have to block SIGURG during putc() because BSD stdio
2005  * is unable to restart interrupted write operations and hence
2006  * the entire buffer contents will be lost as soon as a write()
2007  * call indicates EINTR to stdio.
2008  */
2009 #define FTPD_PUTC(ch, file, label)                                      \
2010         do {                                                            \
2011                 int ret;                                                \
2012                                                                         \
2013                 do {                                                    \
2014                         START_UNSAFE;                                   \
2015                         ret = putc((ch), (file));                       \
2016                         END_UNSAFE;                                     \
2017                         CHECKOOB(return (-1))                           \
2018                         else if (ferror(file))                          \
2019                                 goto label;                             \
2020                         clearerr(file);                                 \
2021                 } while (ret == EOF);                                   \
2022         } while (0)
2023
2024 /*
2025  * Tranfer the contents of "instr" to "outstr" peer using the appropriate
2026  * encapsulation of the data subject to Mode, Structure, and Type.
2027  *
2028  * NB: Form isn't handled.
2029  */
2030 static int
2031 send_data(FILE *instr, FILE *outstr, size_t blksize, off_t filesize, int isreg)
2032 {
2033         int c, cp, filefd, netfd;
2034         char *buf;
2035
2036         STARTXFER;
2037
2038         switch (type) {
2039
2040         case TYPE_A:
2041                 cp = EOF;
2042                 for (;;) {
2043                         c = getc(instr);
2044                         CHECKOOB(return (-1))
2045                         else if (c == EOF && ferror(instr))
2046                                 goto file_err;
2047                         if (c == EOF) {
2048                                 if (ferror(instr)) {    /* resume after OOB */
2049                                         clearerr(instr);
2050                                         continue;
2051                                 }
2052                                 if (feof(instr))        /* EOF */
2053                                         break;
2054                                 syslog(LOG_ERR, "Internal: impossible condition"
2055                                                 " on file after getc()");
2056                                 goto file_err;
2057                         }
2058                         if (c == '\n' && cp != '\r') {
2059                                 FTPD_PUTC('\r', outstr, data_err);
2060                                 byte_count++;
2061                         }
2062                         FTPD_PUTC(c, outstr, data_err);
2063                         byte_count++;
2064                         cp = c;
2065                 }
2066 #ifdef notyet   /* BSD stdio isn't ready for that */
2067                 while (fflush(outstr) == EOF) {
2068                         CHECKOOB(return (-1))
2069                         else
2070                                 goto data_err;
2071                         clearerr(outstr);
2072                 }
2073                 ENDXFER;
2074 #else
2075                 ENDXFER;
2076                 if (fflush(outstr) == EOF)
2077                         goto data_err;
2078 #endif
2079                 reply(226, "Transfer complete.");
2080                 return (0);
2081
2082         case TYPE_I:
2083         case TYPE_L:
2084                 /*
2085                  * isreg is only set if we are not doing restart and we
2086                  * are sending a regular file
2087                  */
2088                 netfd = fileno(outstr);
2089                 filefd = fileno(instr);
2090
2091                 if (isreg) {
2092                         char *msg = "Transfer complete.";
2093                         off_t cnt, offset;
2094                         int err;
2095
2096                         cnt = offset = 0;
2097
2098                         while (filesize > 0) {
2099                                 err = sendfile(filefd, netfd, offset, 0,
2100                                                NULL, &cnt, 0);
2101                                 /*
2102                                  * Calculate byte_count before OOB processing.
2103                                  * It can be used in myoob() later.
2104                                  */
2105                                 byte_count += cnt;
2106                                 offset += cnt;
2107                                 filesize -= cnt;
2108                                 CHECKOOB(return (-1))
2109                                 else if (err == -1) {
2110                                         if (errno != EINTR &&
2111                                             cnt == 0 && offset == 0)
2112                                                 goto oldway;
2113                                         goto data_err;
2114                                 }
2115                                 if (err == -1)  /* resume after OOB */
2116                                         continue;
2117                                 /*
2118                                  * We hit the EOF prematurely.
2119                                  * Perhaps the file was externally truncated.
2120                                  */
2121                                 if (cnt == 0) {
2122                                         msg = "Transfer finished due to "
2123                                               "premature end of file.";
2124                                         break;
2125                                 }
2126                         }
2127                         ENDXFER;
2128                         reply(226, "%s", msg);
2129                         return (0);
2130                 }
2131
2132 oldway:
2133                 if ((buf = malloc(blksize)) == NULL) {
2134                         ENDXFER;
2135                         reply(451, "Ran out of memory.");
2136                         return (-1);
2137                 }
2138
2139                 for (;;) {
2140                         int cnt, len;
2141                         char *bp;
2142
2143                         cnt = read(filefd, buf, blksize);
2144                         CHECKOOB(free(buf); return (-1))
2145                         else if (cnt < 0) {
2146                                 free(buf);
2147                                 goto file_err;
2148                         }
2149                         if (cnt < 0)    /* resume after OOB */
2150                                 continue;
2151                         if (cnt == 0)   /* EOF */
2152                                 break;
2153                         for (len = cnt, bp = buf; len > 0;) {
2154                                 cnt = write(netfd, bp, len);
2155                                 CHECKOOB(free(buf); return (-1))
2156                                 else if (cnt < 0) {
2157                                         free(buf);
2158                                         goto data_err;
2159                                 }
2160                                 if (cnt <= 0)
2161                                         continue;
2162                                 len -= cnt;
2163                                 bp += cnt;
2164                                 byte_count += cnt;
2165                         }
2166                 }
2167                 ENDXFER;
2168                 free(buf);
2169                 reply(226, "Transfer complete.");
2170                 return (0);
2171         default:
2172                 ENDXFER;
2173                 reply(550, "Unimplemented TYPE %d in send_data.", type);
2174                 return (-1);
2175         }
2176
2177 data_err:
2178         ENDXFER;
2179         perror_reply(426, "Data connection");
2180         return (-1);
2181
2182 file_err:
2183         ENDXFER;
2184         perror_reply(551, "Error on input file");
2185         return (-1);
2186 }
2187
2188 /*
2189  * Transfer data from peer to "outstr" using the appropriate encapulation of
2190  * the data subject to Mode, Structure, and Type.
2191  *
2192  * N.B.: Form isn't handled.
2193  */
2194 static int
2195 receive_data(FILE *instr, FILE *outstr)
2196 {
2197         int c, cp;
2198         int bare_lfs = 0;
2199
2200         STARTXFER;
2201
2202         switch (type) {
2203
2204         case TYPE_I:
2205         case TYPE_L:
2206                 for (;;) {
2207                         int cnt, len;
2208                         char *bp;
2209                         char buf[BUFSIZ];
2210
2211                         cnt = read(fileno(instr), buf, sizeof(buf));
2212                         CHECKOOB(return (-1))
2213                         else if (cnt < 0)
2214                                 goto data_err;
2215                         if (cnt < 0)    /* resume after OOB */
2216                                 continue;
2217                         if (cnt == 0)   /* EOF */
2218                                 break;
2219                         for (len = cnt, bp = buf; len > 0;) {
2220                                 cnt = write(fileno(outstr), bp, len);
2221                                 CHECKOOB(return (-1))
2222                                 else if (cnt < 0)
2223                                         goto file_err;
2224                                 if (cnt <= 0)
2225                                         continue;
2226                                 len -= cnt;
2227                                 bp += cnt;
2228                                 byte_count += cnt;
2229                         }
2230                 }
2231                 ENDXFER;
2232                 return (0);
2233
2234         case TYPE_E:
2235                 ENDXFER;
2236                 reply(553, "TYPE E not implemented.");
2237                 return (-1);
2238
2239         case TYPE_A:
2240                 cp = EOF;
2241                 for (;;) {
2242                         c = getc(instr);
2243                         CHECKOOB(return (-1))
2244                         else if (c == EOF && ferror(instr))
2245                                 goto data_err;
2246                         if (c == EOF && ferror(instr)) { /* resume after OOB */
2247                                 clearerr(instr);
2248                                 continue;
2249                         }
2250
2251                         if (cp == '\r') {
2252                                 if (c != '\n')
2253                                         FTPD_PUTC('\r', outstr, file_err);
2254                         } else
2255                                 if (c == '\n')
2256                                         bare_lfs++;
2257                         if (c == '\r') {
2258                                 byte_count++;
2259                                 cp = c;
2260                                 continue;
2261                         }
2262
2263                         /* Check for EOF here in order not to lose last \r. */
2264                         if (c == EOF) {
2265                                 if (feof(instr))        /* EOF */
2266                                         break;
2267                                 syslog(LOG_ERR, "Internal: impossible condition"
2268                                                 " on data stream after getc()");
2269                                 goto data_err;
2270                         }
2271
2272                         byte_count++;
2273                         FTPD_PUTC(c, outstr, file_err);
2274                         cp = c;
2275                 }
2276 #ifdef notyet   /* BSD stdio isn't ready for that */
2277                 while (fflush(outstr) == EOF) {
2278                         CHECKOOB(return (-1))
2279                         else
2280                                 goto file_err;
2281                         clearerr(outstr);
2282                 }
2283                 ENDXFER;
2284 #else
2285                 ENDXFER;
2286                 if (fflush(outstr) == EOF)
2287                         goto file_err;
2288 #endif
2289                 if (bare_lfs) {
2290                         lreply(226,
2291                 "WARNING! %d bare linefeeds received in ASCII mode.",
2292                             bare_lfs);
2293                 printf("   File may not have transferred correctly.\r\n");
2294                 }
2295                 return (0);
2296         default:
2297                 ENDXFER;
2298                 reply(550, "Unimplemented TYPE %d in receive_data.", type);
2299                 return (-1);
2300         }
2301
2302 data_err:
2303         ENDXFER;
2304         perror_reply(426, "Data connection");
2305         return (-1);
2306
2307 file_err:
2308         ENDXFER;
2309         perror_reply(452, "Error writing to file");
2310         return (-1);
2311 }
2312
2313 void
2314 statfilecmd(char *filename)
2315 {
2316         FILE *fin;
2317         int atstart;
2318         int c, code;
2319         char line[LINE_MAX];
2320         struct stat st;
2321
2322         code = lstat(filename, &st) == 0 && S_ISDIR(st.st_mode) ? 212 : 213;
2323         snprintf(line, sizeof(line), _PATH_LS " -lgA %s", filename);
2324         fin = ftpd_popen(line, "r");
2325         lreply(code, "Status of %s:", filename);
2326         atstart = 1;
2327         while ((c = getc(fin)) != EOF) {
2328                 if (c == '\n') {
2329                         if (ferror(stdout)){
2330                                 perror_reply(421, "Control connection");
2331                                 ftpd_pclose(fin);
2332                                 dologout(1);
2333                                 /* NOTREACHED */
2334                         }
2335                         if (ferror(fin)) {
2336                                 perror_reply(551, filename);
2337                                 ftpd_pclose(fin);
2338                                 return;
2339                         }
2340                         putc('\r', stdout);
2341                 }
2342                 /*
2343                  * RFC 959 says neutral text should be prepended before
2344                  * a leading 3-digit number followed by whitespace, but
2345                  * many ftp clients can be confused by any leading digits,
2346                  * as a matter of fact.
2347                  */
2348                 if (atstart && isdigit(c))
2349                         putc(' ', stdout);
2350                 putc(c, stdout);
2351                 atstart = (c == '\n');
2352         }
2353         ftpd_pclose(fin);
2354         reply(code, "End of status.");
2355 }
2356
2357 void
2358 statcmd(void)
2359 {
2360         union sockunion *su;
2361         u_char *a, *p;
2362         char hname[NI_MAXHOST];
2363         int ispassive;
2364
2365         if (hostinfo) {
2366                 lreply(211, "%s FTP server status:", hostname);
2367                 printf("     %s\r\n", version);
2368         } else
2369                 lreply(211, "FTP server status:");
2370         printf("     Connected to %s", remotehost);
2371         if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
2372                          hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {
2373                 hname[sizeof(hname) - 1] = 0;
2374                 if (strcmp(hname, remotehost) != 0)
2375                         printf(" (%s)", hname);
2376         }
2377         printf("\r\n");
2378         if (logged_in) {
2379                 if (guest)
2380                         printf("     Logged in anonymously\r\n");
2381                 else
2382                         printf("     Logged in as %s\r\n", pw->pw_name);
2383         } else if (askpasswd)
2384                 printf("     Waiting for password\r\n");
2385         else
2386                 printf("     Waiting for user name\r\n");
2387         printf("     TYPE: %s", typenames[type]);
2388         if (type == TYPE_A || type == TYPE_E)
2389                 printf(", FORM: %s", formnames[form]);
2390         if (type == TYPE_L)
2391 #if CHAR_BIT == 8
2392                 printf(" %d", CHAR_BIT);
2393 #else
2394                 printf(" %d", bytesize);        /* need definition! */
2395 #endif
2396         printf("; STRUcture: %s; transfer MODE: %s\r\n",
2397             strunames[stru], modenames[mode]);
2398         if (data != -1)
2399                 printf("     Data connection open\r\n");
2400         else if (pdata != -1) {
2401                 ispassive = 1;
2402                 su = &pasv_addr;
2403                 goto printaddr;
2404         } else if (usedefault == 0) {
2405                 ispassive = 0;
2406                 su = &data_dest;
2407 printaddr:
2408 #define UC(b) (((int) b) & 0xff)
2409                 if (epsvall) {
2410                         printf("     EPSV only mode (EPSV ALL)\r\n");
2411                         goto epsvonly;
2412                 }
2413
2414                 /* PORT/PASV */
2415                 if (su->su_family == AF_INET) {
2416                         a = (u_char *) &su->su_sin.sin_addr;
2417                         p = (u_char *) &su->su_sin.sin_port;
2418                         printf("     %s (%d,%d,%d,%d,%d,%d)\r\n",
2419                                 ispassive ? "PASV" : "PORT",
2420                                 UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2421                                 UC(p[0]), UC(p[1]));
2422                 }
2423
2424                 /* LPRT/LPSV */
2425             {
2426                 int alen, af, i;
2427
2428                 switch (su->su_family) {
2429                 case AF_INET:
2430                         a = (u_char *) &su->su_sin.sin_addr;
2431                         p = (u_char *) &su->su_sin.sin_port;
2432                         alen = sizeof(su->su_sin.sin_addr);
2433                         af = 4;
2434                         break;
2435                 case AF_INET6:
2436                         a = (u_char *) &su->su_sin6.sin6_addr;
2437                         p = (u_char *) &su->su_sin6.sin6_port;
2438                         alen = sizeof(su->su_sin6.sin6_addr);
2439                         af = 6;
2440                         break;
2441                 default:
2442                         af = 0;
2443                         break;
2444                 }
2445                 if (af) {
2446                         printf("     %s (%d,%d,", ispassive ? "LPSV" : "LPRT",
2447                                 af, alen);
2448                         for (i = 0; i < alen; i++)
2449                                 printf("%d,", UC(a[i]));
2450                         printf("%d,%d,%d)\r\n", 2, UC(p[0]), UC(p[1]));
2451                 }
2452             }
2453
2454 epsvonly:;
2455                 /* EPRT/EPSV */
2456             {
2457                 int af;
2458
2459                 switch (su->su_family) {
2460                 case AF_INET:
2461                         af = 1;
2462                         break;
2463                 case AF_INET6:
2464                         af = 2;
2465                         break;
2466                 default:
2467                         af = 0;
2468                         break;
2469                 }
2470                 if (af) {
2471                         union sockunion tmp;
2472
2473                         tmp = *su;
2474                         if (tmp.su_family == AF_INET6)
2475                                 tmp.su_sin6.sin6_scope_id = 0;
2476                         if (!getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
2477                                         hname, sizeof(hname) - 1, NULL, 0,
2478                                         NI_NUMERICHOST)) {
2479                                 hname[sizeof(hname) - 1] = 0;
2480                                 printf("     %s |%d|%s|%d|\r\n",
2481                                         ispassive ? "EPSV" : "EPRT",
2482                                         af, hname, htons(tmp.su_port));
2483                         }
2484                 }
2485             }
2486 #undef UC
2487         } else
2488                 printf("     No data connection\r\n");
2489         reply(211, "End of status.");
2490 }
2491
2492 void
2493 fatalerror(char *s)
2494 {
2495
2496         reply(451, "Error in server: %s", s);
2497         reply(221, "Closing connection due to server error.");
2498         dologout(0);
2499         /* NOTREACHED */
2500 }
2501
2502 void
2503 reply(int n, const char *fmt, ...)
2504 {
2505         va_list ap;
2506
2507         printf("%d ", n);
2508         va_start(ap, fmt);
2509         vprintf(fmt, ap);
2510         va_end(ap);
2511         printf("\r\n");
2512         fflush(stdout);
2513         if (ftpdebug) {
2514                 syslog(LOG_DEBUG, "<--- %d ", n);
2515                 va_start(ap, fmt);
2516                 vsyslog(LOG_DEBUG, fmt, ap);
2517                 va_end(ap);
2518         }
2519 }
2520
2521 void
2522 lreply(int n, const char *fmt, ...)
2523 {
2524         va_list ap;
2525
2526         printf("%d- ", n);
2527         va_start(ap, fmt);
2528         vprintf(fmt, ap);
2529         va_end(ap);
2530         printf("\r\n");
2531         fflush(stdout);
2532         if (ftpdebug) {
2533                 syslog(LOG_DEBUG, "<--- %d- ", n);
2534                 va_start(ap, fmt);
2535                 vsyslog(LOG_DEBUG, fmt, ap);
2536                 va_end(ap);
2537         }
2538 }
2539
2540 static void
2541 ack(char *s)
2542 {
2543
2544         reply(250, "%s command successful.", s);
2545 }
2546
2547 void
2548 nack(char *s)
2549 {
2550
2551         reply(502, "%s command not implemented.", s);
2552 }
2553
2554 /* ARGSUSED */
2555 void
2556 yyerror(char *s)
2557 {
2558         char *cp;
2559
2560         if ((cp = strchr(cbuf,'\n')))
2561                 *cp = '\0';
2562         reply(500, "%s: command not understood.", cbuf);
2563 }
2564
2565 void
2566 delete(char *name)
2567 {
2568         struct stat st;
2569
2570         LOGCMD("delete", name);
2571         if (lstat(name, &st) < 0) {
2572                 perror_reply(550, name);
2573                 return;
2574         }
2575         if (S_ISDIR(st.st_mode)) {
2576                 if (rmdir(name) < 0) {
2577                         perror_reply(550, name);
2578                         return;
2579                 }
2580                 goto done;
2581         }
2582         if (guest && noguestmod) {
2583                 reply(550, "Operation not permitted.");
2584                 return;
2585         }
2586         if (unlink(name) < 0) {
2587                 perror_reply(550, name);
2588                 return;
2589         }
2590 done:
2591         ack("DELE");
2592 }
2593
2594 void
2595 cwd(char *path)
2596 {
2597
2598         if (chdir(path) < 0)
2599                 perror_reply(550, path);
2600         else
2601                 ack("CWD");
2602 }
2603
2604 void
2605 makedir(char *name)
2606 {
2607         char *s;
2608
2609         LOGCMD("mkdir", name);
2610         if (guest && noguestmkd)
2611                 reply(550, "Operation not permitted.");
2612         else if (mkdir(name, 0777) < 0)
2613                 perror_reply(550, name);
2614         else {
2615                 if ((s = doublequote(name)) == NULL)
2616                         fatalerror("Ran out of memory.");
2617                 reply(257, "\"%s\" directory created.", s);
2618                 free(s);
2619         }
2620 }
2621
2622 void
2623 removedir(char *name)
2624 {
2625
2626         LOGCMD("rmdir", name);
2627         if (rmdir(name) < 0)
2628                 perror_reply(550, name);
2629         else
2630                 ack("RMD");
2631 }
2632
2633 void
2634 pwd(void)
2635 {
2636         char *s, path[MAXPATHLEN + 1];
2637
2638         if (getcwd(path, sizeof(path)) == NULL)
2639                 perror_reply(550, "Get current directory");
2640         else {
2641                 if ((s = doublequote(path)) == NULL)
2642                         fatalerror("Ran out of memory.");
2643                 reply(257, "\"%s\" is current directory.", s);
2644                 free(s);
2645         }
2646 }
2647
2648 char *
2649 renamefrom(char *name)
2650 {
2651         struct stat st;
2652
2653         if (guest && noguestmod) {
2654                 reply(550, "Operation not permitted.");
2655                 return (NULL);
2656         }
2657         if (lstat(name, &st) < 0) {
2658                 perror_reply(550, name);
2659                 return (NULL);
2660         }
2661         reply(350, "File exists, ready for destination name.");
2662         return (name);
2663 }
2664
2665 void
2666 renamecmd(char *from, char *to)
2667 {
2668         struct stat st;
2669
2670         LOGCMD2("rename", from, to);
2671
2672         if (guest && (stat(to, &st) == 0)) {
2673                 reply(550, "%s: permission denied.", to);
2674                 return;
2675         }
2676
2677         if (rename(from, to) < 0)
2678                 perror_reply(550, "rename");
2679         else
2680                 ack("RNTO");
2681 }
2682
2683 static void
2684 dolog(struct sockaddr *who)
2685 {
2686         char who_name[NI_MAXHOST];
2687
2688         realhostname_sa(remotehost, sizeof(remotehost) - 1, who, who->sa_len);
2689         remotehost[sizeof(remotehost) - 1] = 0;
2690         if (getnameinfo(who, who->sa_len,
2691                 who_name, sizeof(who_name) - 1, NULL, 0, NI_NUMERICHOST))
2692                         *who_name = 0;
2693         who_name[sizeof(who_name) - 1] = 0;
2694
2695 #ifdef SETPROCTITLE
2696 #ifdef VIRTUAL_HOSTING
2697         if (thishost != firsthost)
2698                 snprintf(proctitle, sizeof(proctitle), "%s: connected (to %s)",
2699                          remotehost, hostname);
2700         else
2701 #endif
2702                 snprintf(proctitle, sizeof(proctitle), "%s: connected",
2703                          remotehost);
2704         setproctitle("%s", proctitle);
2705 #endif /* SETPROCTITLE */
2706
2707         if (logging) {
2708 #ifdef VIRTUAL_HOSTING
2709                 if (thishost != firsthost)
2710                         syslog(LOG_INFO, "connection from %s (%s) to %s",
2711                                remotehost, who_name, hostname);
2712                 else
2713 #endif
2714                         syslog(LOG_INFO, "connection from %s (%s)",
2715                                remotehost, who_name);
2716         }
2717 }
2718
2719 /*
2720  * Record logout in wtmp file
2721  * and exit with supplied status.
2722  */
2723 void
2724 dologout(int status)
2725 {
2726
2727         if (logged_in && dowtmp) {
2728                 seteuid(0);
2729                 ftpd_logwtmp(ttyline, "", NULL);
2730         }
2731         /* beware of flushing buffers after a SIGPIPE */
2732         _exit(status);
2733 }
2734
2735 static void
2736 sigurg(int signo)
2737 {
2738
2739         recvurg = 1;
2740 }
2741
2742 static void
2743 maskurg(int flag)
2744 {
2745         int oerrno;
2746         sigset_t sset;
2747
2748         if (!transflag) {
2749                 syslog(LOG_ERR, "Internal: maskurg() while no transfer");
2750                 return;
2751         }
2752         oerrno = errno;
2753         sigemptyset(&sset);
2754         sigaddset(&sset, SIGURG);
2755         sigprocmask(flag ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
2756         errno = oerrno;
2757 }
2758
2759 static void
2760 flagxfer(int flag)
2761 {
2762
2763         if (flag) {
2764                 if (transflag)
2765                         syslog(LOG_ERR, "Internal: flagxfer(1): "
2766                                         "transfer already under way");
2767                 transflag = 1;
2768                 maskurg(0);
2769                 recvurg = 0;
2770         } else {
2771                 if (!transflag)
2772                         syslog(LOG_ERR, "Internal: flagxfer(0): "
2773                                         "no active transfer");
2774                 maskurg(1);
2775                 transflag = 0;
2776         }
2777 }
2778
2779 /*
2780  * Returns 0 if OK to resume or -1 if abort requested.
2781  */
2782 static int
2783 myoob(void)
2784 {
2785         char *cp;
2786         int ret;
2787
2788         if (!transflag) {
2789                 syslog(LOG_ERR, "Internal: myoob() while no transfer");
2790                 return (0);
2791         }
2792         cp = tmpline;
2793         ret = get_line(cp, 7, stdin);
2794         if (ret == -1) {
2795                 reply(221, "You could at least say goodbye.");
2796                 dologout(0);
2797         } else if (ret == -2) {
2798                 /* Ignore truncated command. */
2799                 return (0);
2800         }
2801         upper(cp);
2802         if (strcmp(cp, "ABOR\r\n") == 0) {
2803                 tmpline[0] = '\0';
2804                 reply(426, "Transfer aborted. Data connection closed.");
2805                 reply(226, "Abort successful.");
2806                 return (-1);
2807         }
2808         if (strcmp(cp, "STAT\r\n") == 0) {
2809                 tmpline[0] = '\0';
2810                 if (file_size != -1)
2811                         reply(213, "Status: %jd of %jd bytes transferred.",
2812                                    (intmax_t)byte_count, (intmax_t)file_size);
2813                 else
2814                         reply(213, "Status: %jd bytes transferred.",
2815                                    (intmax_t)byte_count);
2816         }
2817         return (0);
2818 }
2819
2820 /*
2821  * Note: a response of 425 is not mentioned as a possible response to
2822  *      the PASV command in RFC959. However, it has been blessed as
2823  *      a legitimate response by Jon Postel in a telephone conversation
2824  *      with Rick Adams on 25 Jan 89.
2825  */
2826 void
2827 passive(void)
2828 {
2829         socklen_t len;
2830         int on;
2831         char *p, *a;
2832
2833         if (pdata >= 0)         /* close old port if one set */
2834                 close(pdata);
2835
2836         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2837         if (pdata < 0) {
2838                 perror_reply(425, "Can't open passive connection");
2839                 return;
2840         }
2841         on = 1;
2842         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2843                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2844
2845         seteuid(0);
2846
2847 #ifdef IP_PORTRANGE
2848         if (ctrl_addr.su_family == AF_INET) {
2849             on = restricted_data_ports ? IP_PORTRANGE_HIGH
2850                                        : IP_PORTRANGE_DEFAULT;
2851
2852             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2853                             &on, sizeof(on)) < 0)
2854                     goto pasv_error;
2855         }
2856 #endif
2857 #ifdef IPV6_PORTRANGE
2858         if (ctrl_addr.su_family == AF_INET6) {
2859             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2860                                        : IPV6_PORTRANGE_DEFAULT;
2861
2862             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2863                             &on, sizeof(on)) < 0)
2864                     goto pasv_error;
2865         }
2866 #endif
2867
2868         pasv_addr = ctrl_addr;
2869         pasv_addr.su_port = 0;
2870         if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2871                 goto pasv_error;
2872
2873         seteuid(pw->pw_uid);
2874
2875         len = sizeof(pasv_addr);
2876         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2877                 goto pasv_error;
2878         if (listen(pdata, 1) < 0)
2879                 goto pasv_error;
2880         if (pasv_addr.su_family == AF_INET)
2881                 a = (char *) &pasv_addr.su_sin.sin_addr;
2882         else if (pasv_addr.su_family == AF_INET6 &&
2883                  IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr))
2884                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2885         else
2886                 goto pasv_error;
2887
2888         p = (char *) &pasv_addr.su_port;
2889
2890 #define UC(b) (((int) b) & 0xff)
2891
2892         reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
2893                 UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
2894         return;
2895
2896 pasv_error:
2897         seteuid(pw->pw_uid);
2898         close(pdata);
2899         pdata = -1;
2900         perror_reply(425, "Can't open passive connection");
2901         return;
2902 }
2903
2904 /*
2905  * Long Passive defined in RFC 1639.
2906  *     228 Entering Long Passive Mode
2907  *         (af, hal, h1, h2, h3,..., pal, p1, p2...)
2908  */
2909
2910 void
2911 long_passive(char *cmd, int pf)
2912 {
2913         socklen_t len;
2914         int on;
2915         char *p, *a;
2916
2917         if (pdata >= 0)         /* close old port if one set */
2918                 close(pdata);
2919
2920         if (pf != PF_UNSPEC) {
2921                 if (ctrl_addr.su_family != pf) {
2922                         switch (ctrl_addr.su_family) {
2923                         case AF_INET:
2924                                 pf = 1;
2925                                 break;
2926                         case AF_INET6:
2927                                 pf = 2;
2928                                 break;
2929                         default:
2930                                 pf = 0;
2931                                 break;
2932                         }
2933                         /*
2934                          * XXX
2935                          * only EPRT/EPSV ready clients will understand this
2936                          */
2937                         if (strcmp(cmd, "EPSV") == 0 && pf) {
2938                                 reply(522, "Network protocol mismatch, "
2939                                         "use (%d)", pf);
2940                         } else
2941                                 reply(501, "Network protocol mismatch."); /*XXX*/
2942
2943                         return;
2944                 }
2945         }
2946
2947         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2948         if (pdata < 0) {
2949                 perror_reply(425, "Can't open passive connection");
2950                 return;
2951         }
2952         on = 1;
2953         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2954                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2955
2956         seteuid(0);
2957
2958         pasv_addr = ctrl_addr;
2959         pasv_addr.su_port = 0;
2960         len = pasv_addr.su_len;
2961
2962 #ifdef IP_PORTRANGE
2963         if (ctrl_addr.su_family == AF_INET) {
2964             on = restricted_data_ports ? IP_PORTRANGE_HIGH
2965                                        : IP_PORTRANGE_DEFAULT;
2966
2967             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2968                             &on, sizeof(on)) < 0)
2969                     goto pasv_error;
2970         }
2971 #endif
2972 #ifdef IPV6_PORTRANGE
2973         if (ctrl_addr.su_family == AF_INET6) {
2974             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2975                                        : IPV6_PORTRANGE_DEFAULT;
2976
2977             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2978                             &on, sizeof(on)) < 0)
2979                     goto pasv_error;
2980         }
2981 #endif
2982
2983         if (bind(pdata, (struct sockaddr *)&pasv_addr, len) < 0)
2984                 goto pasv_error;
2985
2986         seteuid(pw->pw_uid);
2987
2988         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2989                 goto pasv_error;
2990         if (listen(pdata, 1) < 0)
2991                 goto pasv_error;
2992
2993 #define UC(b) (((int) b) & 0xff)
2994
2995         if (strcmp(cmd, "LPSV") == 0) {
2996                 p = (char *)&pasv_addr.su_port;
2997                 switch (pasv_addr.su_family) {
2998                 case AF_INET:
2999                         a = (char *) &pasv_addr.su_sin.sin_addr;
3000                 v4_reply:
3001                         reply(228,
3002 "Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3003                               4, 4, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3004                               2, UC(p[0]), UC(p[1]));
3005                         return;
3006                 case AF_INET6:
3007                         if (IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr)) {
3008                                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
3009                                 goto v4_reply;
3010                         }
3011                         a = (char *) &pasv_addr.su_sin6.sin6_addr;
3012                         reply(228,
3013 "Entering Long Passive Mode "
3014 "(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3015                               6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3016                               UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
3017                               UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
3018                               UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
3019                               2, UC(p[0]), UC(p[1]));
3020                         return;
3021                 }
3022         } else if (strcmp(cmd, "EPSV") == 0) {
3023                 switch (pasv_addr.su_family) {
3024                 case AF_INET:
3025                 case AF_INET6:
3026                         reply(229, "Entering Extended Passive Mode (|||%d|)",
3027                                 ntohs(pasv_addr.su_port));
3028                         return;
3029                 }
3030         } else {
3031                 /* more proper error code? */
3032         }
3033
3034 pasv_error:
3035         seteuid(pw->pw_uid);
3036         close(pdata);
3037         pdata = -1;
3038         perror_reply(425, "Can't open passive connection");
3039         return;
3040 }
3041
3042 /*
3043  * Generate unique name for file with basename "local"
3044  * and open the file in order to avoid possible races.
3045  * Try "local" first, then "local.1", "local.2" etc, up to "local.99".
3046  * Return descriptor to the file, set "name" to its name.
3047  *
3048  * Generates failure reply on error.
3049  */
3050 static int
3051 guniquefd(char *local, char **name)
3052 {
3053         static char new[MAXPATHLEN];
3054         struct stat st;
3055         char *cp;
3056         int count;
3057         int fd;
3058
3059         cp = strrchr(local, '/');
3060         if (cp)
3061                 *cp = '\0';
3062         if (stat(cp ? local : ".", &st) < 0) {
3063                 perror_reply(553, cp ? local : ".");
3064                 return (-1);
3065         }
3066         if (cp) {
3067                 /*
3068                  * Let not overwrite dirname with counter suffix.
3069                  * -4 is for /nn\0
3070                  * In this extreme case dot won't be put in front of suffix.
3071                  */
3072                 if (strlen(local) > sizeof(new) - 4) {
3073                         reply(553, "Pathname too long.");
3074                         return (-1);
3075                 }
3076                 *cp = '/';
3077         }
3078         /* -4 is for the .nn<null> we put on the end below */
3079         snprintf(new, sizeof(new) - 4, "%s", local);
3080         cp = new + strlen(new);
3081         /*
3082          * Don't generate dotfile unless requested explicitly.
3083          * This covers the case when basename gets truncated off
3084          * by buffer size.
3085          */
3086         if (cp > new && cp[-1] != '/')
3087                 *cp++ = '.';
3088         for (count = 0; count < 100; count++) {
3089                 /* At count 0 try unmodified name */
3090                 if (count)
3091                         sprintf(cp, "%d", count);
3092                 if ((fd = open(count ? new : local,
3093                     O_RDWR | O_CREAT | O_EXCL, 0666)) >= 0) {
3094                         *name = count ? new : local;
3095                         return (fd);
3096                 }
3097                 if (errno != EEXIST) {
3098                         perror_reply(553, count ? new : local);
3099                         return (-1);
3100                 }
3101         }
3102         reply(452, "Unique file name cannot be created.");
3103         return (-1);
3104 }
3105
3106 /*
3107  * Format and send reply containing system error number.
3108  */
3109 void
3110 perror_reply(int code, char *string)
3111 {
3112
3113         reply(code, "%s: %s.", string, strerror(errno));
3114 }
3115
3116 static char *onefile[] = {
3117         "",
3118         0
3119 };
3120
3121 void
3122 send_file_list(char *whichf)
3123 {
3124         struct stat st;
3125         DIR *dirp = NULL;
3126         struct dirent *dir;
3127         FILE *dout = NULL;
3128         char **dirlist, *dirname;
3129         int simple = 0;
3130         int freeglob = 0;
3131         glob_t gl;
3132
3133         if (strpbrk(whichf, "~{[*?") != NULL) {
3134                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
3135
3136                 memset(&gl, 0, sizeof(gl));
3137                 gl.gl_matchc = MAXGLOBARGS;
3138                 /*flags |= GLOB_LIMIT;*/
3139                 freeglob = 1;
3140                 if (glob(whichf, flags, 0, &gl)) {
3141                         reply(550, "No matching files found.");
3142                         goto out;
3143                 } else if (gl.gl_pathc == 0) {
3144                         errno = ENOENT;
3145                         perror_reply(550, whichf);
3146                         goto out;
3147                 }
3148                 dirlist = gl.gl_pathv;
3149         } else {
3150                 onefile[0] = whichf;
3151                 dirlist = onefile;
3152                 simple = 1;
3153         }
3154
3155         while ((dirname = *dirlist++)) {
3156                 if (stat(dirname, &st) < 0) {
3157                         /*
3158                          * If user typed "ls -l", etc, and the client
3159                          * used NLST, do what the user meant.
3160                          */
3161                         if (dirname[0] == '-' && *dirlist == NULL &&
3162                             dout == NULL)
3163                                 retrieve(_PATH_LS " %s", dirname);
3164                         else
3165                                 perror_reply(550, whichf);
3166                         goto out;
3167                 }
3168
3169                 if (S_ISREG(st.st_mode)) {
3170                         if (dout == NULL) {
3171                                 dout = dataconn("file list", -1, "w");
3172                                 if (dout == NULL)
3173                                         goto out;
3174                                 STARTXFER;
3175                         }
3176                         START_UNSAFE;
3177                         fprintf(dout, "%s%s\n", dirname,
3178                                 type == TYPE_A ? "\r" : "");
3179                         END_UNSAFE;
3180                         if (ferror(dout))
3181                                 goto data_err;
3182                         byte_count += strlen(dirname) +
3183                                       (type == TYPE_A ? 2 : 1);
3184                         CHECKOOB(goto abrt);
3185                         continue;
3186                 } else if (!S_ISDIR(st.st_mode))
3187                         continue;
3188
3189                 if ((dirp = opendir(dirname)) == NULL)
3190                         continue;
3191
3192                 while ((dir = readdir(dirp)) != NULL) {
3193                         char nbuf[MAXPATHLEN];
3194
3195                         CHECKOOB(goto abrt);
3196
3197                         if (strcmp(dir->d_name, ".") == 0)
3198                                 continue;
3199                         if (strcmp(dir->d_name, "..") == 0)
3200                                 continue;
3201
3202                         snprintf(nbuf, sizeof(nbuf),
3203                                 "%s/%s", dirname, dir->d_name);
3204
3205                         /*
3206                          * We have to do a stat to insure it's
3207                          * not a directory or special file.
3208                          */
3209                         if (simple || (stat(nbuf, &st) == 0 &&
3210                             S_ISREG(st.st_mode))) {
3211                                 if (dout == NULL) {
3212                                         dout = dataconn("file list", -1, "w");
3213                                         if (dout == NULL)
3214                                                 goto out;
3215                                         STARTXFER;
3216                                 }
3217                                 START_UNSAFE;
3218                                 if (nbuf[0] == '.' && nbuf[1] == '/')
3219                                         fprintf(dout, "%s%s\n", &nbuf[2],
3220                                                 type == TYPE_A ? "\r" : "");
3221                                 else
3222                                         fprintf(dout, "%s%s\n", nbuf,
3223                                                 type == TYPE_A ? "\r" : "");
3224                                 END_UNSAFE;
3225                                 if (ferror(dout))
3226                                         goto data_err;
3227                                 byte_count += strlen(nbuf) +
3228                                               (type == TYPE_A ? 2 : 1);
3229                                 CHECKOOB(goto abrt);
3230                         }
3231                 }
3232                 closedir(dirp);
3233                 dirp = NULL;
3234         }
3235
3236         if (dout == NULL)
3237                 reply(550, "No files found.");
3238         else if (ferror(dout))
3239 data_err:       perror_reply(550, "Data connection");
3240         else
3241                 reply(226, "Transfer complete.");
3242 out:
3243         if (dout) {
3244                 ENDXFER;
3245 abrt:
3246                 fclose(dout);
3247                 data = -1;
3248                 pdata = -1;
3249         }
3250         if (dirp)
3251                 closedir(dirp);
3252         if (freeglob) {
3253                 freeglob = 0;
3254                 globfree(&gl);
3255         }
3256 }
3257
3258 void
3259 reapchild(int signo)
3260 {
3261         while (waitpid(-1, NULL, WNOHANG) > 0);
3262 }
3263
3264 static void
3265 appendf(char **strp, char *fmt, ...)
3266 {
3267         va_list ap;
3268         char *ostr, *p;
3269
3270         va_start(ap, fmt);
3271         vasprintf(&p, fmt, ap);
3272         va_end(ap);
3273         if (p == NULL)
3274                 fatalerror("Ran out of memory.");
3275         if (*strp == NULL)
3276                 *strp = p;
3277         else {
3278                 ostr = *strp;
3279                 asprintf(strp, "%s%s", ostr, p);
3280                 if (*strp == NULL)
3281                         fatalerror("Ran out of memory.");
3282                 free(ostr);
3283         }
3284 }
3285
3286 static void
3287 logcmd(char *cmd, char *file1, char *file2, off_t cnt)
3288 {
3289         char *msg = NULL;
3290         char wd[MAXPATHLEN + 1];
3291
3292         if (logging <= 1)
3293                 return;
3294
3295         if (getcwd(wd, sizeof(wd) - 1) == NULL)
3296                 strcpy(wd, strerror(errno));
3297
3298         appendf(&msg, "%s", cmd);
3299         if (file1)
3300                 appendf(&msg, " %s", file1);
3301         if (file2)
3302                 appendf(&msg, " %s", file2);
3303         if (cnt >= 0)
3304                 appendf(&msg, " = %jd bytes", (intmax_t)cnt);
3305         appendf(&msg, " (wd: %s", wd);
3306         if (guest || dochroot)
3307                 appendf(&msg, "; chrooted");
3308         appendf(&msg, ")");
3309         syslog(LOG_INFO, "%s", msg);
3310         free(msg);
3311 }
3312
3313 static void
3314 logxfer(char *name, off_t size, time_t start)
3315 {
3316         char buf[MAXPATHLEN + 1024];
3317         char path[MAXPATHLEN + 1];
3318         time_t now;
3319
3320         if (statfd >= 0) {
3321                 time(&now);
3322                 if (realpath(name, path) == NULL) {
3323                         syslog(LOG_NOTICE, "realpath failed on %s: %m", path);
3324                         return;
3325                 }
3326                 snprintf(buf, sizeof(buf), "%.20s!%s!%s!%s!%jd!%ld\n",
3327                         ctime(&now)+4, ident, remotehost,
3328                         path, (intmax_t)size,
3329                         (long)(now - start + (now == start)));
3330                 write(statfd, buf, strlen(buf));
3331         }
3332 }
3333
3334 static char *
3335 doublequote(char *s)
3336 {
3337         int n;
3338         char *p, *s2;
3339
3340         for (p = s, n = 0; *p; p++)
3341                 if (*p == '"')
3342                         n++;
3343
3344         if ((s2 = malloc(p - s + n + 1)) == NULL)
3345                 return (NULL);
3346
3347         for (p = s2; *s; s++, p++) {
3348                 if ((*p = *s) == '"')
3349                         *(++p) = '"';
3350         }
3351         *p = '\0';
3352
3353         return (s2);
3354 }
3355
3356 /* setup server socket for specified address family */
3357 /* if af is PF_UNSPEC more than one socket may be returned */
3358 /* the returned list is dynamically allocated, so caller needs to free it */
3359 static int *
3360 socksetup(int af, char *bindname, const char *bindport)
3361 {
3362         struct addrinfo hints, *res, *r;
3363         int error, maxs, *s, *socks;
3364         const int on = 1;
3365
3366         memset(&hints, 0, sizeof(hints));
3367         hints.ai_flags = AI_PASSIVE;
3368         hints.ai_family = af;
3369         hints.ai_socktype = SOCK_STREAM;
3370         error = getaddrinfo(bindname, bindport, &hints, &res);
3371         if (error) {
3372                 syslog(LOG_ERR, "%s", gai_strerror(error));
3373                 if (error == EAI_SYSTEM)
3374                         syslog(LOG_ERR, "%s", strerror(errno));
3375                 return NULL;
3376         }
3377
3378         /* Count max number of sockets we may open */
3379         for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
3380                 ;
3381         socks = malloc((maxs + 1) * sizeof(int));
3382         if (!socks) {
3383                 freeaddrinfo(res);
3384                 syslog(LOG_ERR, "couldn't allocate memory for sockets");
3385                 return NULL;
3386         }
3387
3388         *socks = 0;   /* num of sockets counter at start of array */
3389         s = socks + 1;
3390         for (r = res; r; r = r->ai_next) {
3391                 *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
3392                 if (*s < 0) {
3393                         syslog(LOG_DEBUG, "control socket: %m");
3394                         continue;
3395                 }
3396                 if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR,
3397                     &on, sizeof(on)) < 0)
3398                         syslog(LOG_WARNING,
3399                             "control setsockopt (SO_REUSEADDR): %m");
3400                 if (r->ai_family == AF_INET6) {
3401                         if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY,
3402                             &on, sizeof(on)) < 0)
3403                                 syslog(LOG_WARNING,
3404                                     "control setsockopt (IPV6_V6ONLY): %m");
3405                 }
3406                 if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
3407                         syslog(LOG_DEBUG, "control bind: %m");
3408                         close(*s);
3409                         continue;
3410                 }
3411                 (*socks)++;
3412                 s++;
3413         }
3414
3415         if (res)
3416                 freeaddrinfo(res);
3417
3418         if (*socks == 0) {
3419                 syslog(LOG_ERR, "control socket: Couldn't bind to any socket");
3420                 free(socks);
3421                 return NULL;
3422         }
3423         return(socks);
3424 }