libexec/ftpd/ftpd.c

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