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