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