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[FreeBSD/FreeBSD.git] / libexec / ftpd / ftpd.c
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
5  *      The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31
32 #if 0
33 #ifndef lint
34 static char copyright[] =
35 "@(#) Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994\n\
36         The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 #endif
39
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)ftpd.c      8.4 (Berkeley) 4/16/94";
43 #endif
44 #endif /* not lint */
45
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48
49 /*
50  * FTP server.
51  */
52 #include <sys/param.h>
53 #include <sys/ioctl.h>
54 #include <sys/mman.h>
55 #include <sys/socket.h>
56 #include <sys/stat.h>
57 #include <sys/time.h>
58 #include <sys/wait.h>
59
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/ip.h>
63 #include <netinet/tcp.h>
64
65 #define FTP_NAMES
66 #include <arpa/ftp.h>
67 #include <arpa/inet.h>
68 #include <arpa/telnet.h>
69
70 #include <ctype.h>
71 #include <dirent.h>
72 #include <err.h>
73 #include <errno.h>
74 #include <fcntl.h>
75 #include <glob.h>
76 #include <limits.h>
77 #include <netdb.h>
78 #include <pwd.h>
79 #include <grp.h>
80 #include <opie.h>
81 #include <signal.h>
82 #include <stdint.h>
83 #include <stdio.h>
84 #include <stdlib.h>
85 #include <string.h>
86 #include <syslog.h>
87 #include <time.h>
88 #include <unistd.h>
89 #include <libutil.h>
90 #ifdef  LOGIN_CAP
91 #include <login_cap.h>
92 #endif
93
94 #ifdef USE_PAM
95 #include <security/pam_appl.h>
96 #endif
97
98 #include "blacklist_client.h"
99 #include "pathnames.h"
100 #include "extern.h"
101
102 #include <stdarg.h>
103
104 static char version[] = "Version 6.00LS";
105 #undef main
106
107 union sockunion ctrl_addr;
108 union sockunion data_source;
109 union sockunion data_dest;
110 union sockunion his_addr;
111 union sockunion pasv_addr;
112
113 int     daemon_mode;
114 int     data;
115 int     dataport;
116 int     hostinfo = 1;   /* print host-specific info in messages */
117 int     logged_in;
118 struct  passwd *pw;
119 char    *homedir;
120 int     ftpdebug;
121 int     timeout = 900;    /* timeout after 15 minutes of inactivity */
122 int     maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
123 int     logging;
124 int     restricted_data_ports = 1;
125 int     paranoid = 1;     /* be extra careful about security */
126 int     anon_only = 0;    /* Only anonymous ftp allowed */
127 int     assumeutf8 = 0;   /* Assume that server file names are in UTF-8 */
128 int     guest;
129 int     dochroot;
130 char    *chrootdir;
131 int     dowtmp = 1;
132 int     stats;
133 int     statfd = -1;
134 int     type;
135 int     form;
136 int     stru;                   /* avoid C keyword */
137 int     mode;
138 int     usedefault = 1;         /* for data transfers */
139 int     pdata = -1;             /* for passive mode */
140 int     readonly = 0;           /* Server is in readonly mode.  */
141 int     noepsv = 0;             /* EPSV command is disabled.    */
142 int     noretr = 0;             /* RETR command is disabled.    */
143 int     noguestretr = 0;        /* RETR command is disabled for anon users. */
144 int     noguestmkd = 0;         /* MKD command is disabled for anon users. */
145 int     noguestmod = 1;         /* anon users may not modify existing files. */
146 int     use_blacklist = 0;
147
148 off_t   file_size;
149 off_t   byte_count;
150 #if !defined(CMASK) || CMASK == 0
151 #undef CMASK
152 #define CMASK 027
153 #endif
154 int     defumask = CMASK;               /* default umask value */
155 char    tmpline[7];
156 char    *hostname;
157 int     epsvall = 0;
158
159 #ifdef VIRTUAL_HOSTING
160 char    *ftpuser;
161
162 static struct ftphost {
163         struct ftphost  *next;
164         struct addrinfo *hostinfo;
165         char            *hostname;
166         char            *anonuser;
167         char            *statfile;
168         char            *welcome;
169         char            *loginmsg;
170 } *thishost, *firsthost;
171
172 #endif
173 char    remotehost[NI_MAXHOST];
174 char    *ident = NULL;
175
176 static char     wtmpid[20];
177
178 #ifdef USE_PAM
179 static int      auth_pam(struct passwd**, const char*);
180 pam_handle_t    *pamh = NULL;
181 #endif
182
183 static struct opie      opiedata;
184 static char             opieprompt[OPIE_CHALLENGE_MAX+1];
185 static int              pwok;
186
187 char    *pid_file = NULL; /* means default location to pidfile(3) */
188
189 /*
190  * Limit number of pathnames that glob can return.
191  * A limit of 0 indicates the number of pathnames is unlimited.
192  */
193 #define MAXGLOBARGS     16384
194 #
195
196 /*
197  * Timeout intervals for retrying connections
198  * to hosts that don't accept PORT cmds.  This
199  * is a kludge, but given the problems with TCP...
200  */
201 #define SWAITMAX        90      /* wait at most 90 seconds */
202 #define SWAITINT        5       /* interval between retries */
203
204 int     swaitmax = SWAITMAX;
205 int     swaitint = SWAITINT;
206
207 #ifdef SETPROCTITLE
208 #ifdef OLD_SETPROCTITLE
209 char    **Argv = NULL;          /* pointer to argument vector */
210 char    *LastArgv = NULL;       /* end of argv */
211 #endif /* OLD_SETPROCTITLE */
212 char    proctitle[LINE_MAX];    /* initial part of title */
213 #endif /* SETPROCTITLE */
214
215 #define LOGCMD(cmd, file)               logcmd((cmd), (file), NULL, -1)
216 #define LOGCMD2(cmd, file1, file2)      logcmd((cmd), (file1), (file2), -1)
217 #define LOGBYTES(cmd, file, cnt)        logcmd((cmd), (file), NULL, (cnt))
218
219 static  volatile sig_atomic_t recvurg;
220 static  int transflag;          /* NB: for debugging only */
221
222 #define STARTXFER       flagxfer(1)
223 #define ENDXFER         flagxfer(0)
224
225 #define START_UNSAFE    maskurg(1)
226 #define END_UNSAFE      maskurg(0)
227
228 /* It's OK to put an `else' clause after this macro. */
229 #define CHECKOOB(action)                                                \
230         if (recvurg) {                                                  \
231                 recvurg = 0;                                            \
232                 if (myoob()) {                                          \
233                         ENDXFER;                                        \
234                         action;                                         \
235                 }                                                       \
236         }
237
238 #ifdef VIRTUAL_HOSTING
239 static void      inithosts(int);
240 static void      selecthost(union sockunion *);
241 #endif
242 static void      ack(char *);
243 static void      sigurg(int);
244 static void      maskurg(int);
245 static void      flagxfer(int);
246 static int       myoob(void);
247 static int       checkuser(char *, char *, int, char **, int *);
248 static FILE     *dataconn(char *, off_t, char *);
249 static void      dolog(struct sockaddr *);
250 static void      end_login(void);
251 static FILE     *getdatasock(char *);
252 static int       guniquefd(char *, char **);
253 static void      lostconn(int);
254 static void      sigquit(int);
255 static int       receive_data(FILE *, FILE *);
256 static int       send_data(FILE *, FILE *, size_t, off_t, int);
257 static struct passwd *
258                  sgetpwnam(char *);
259 static char     *sgetsave(char *);
260 static void      reapchild(int);
261 static void      appendf(char **, char *, ...) __printflike(2, 3);
262 static void      logcmd(char *, char *, char *, off_t);
263 static void      logxfer(char *, off_t, time_t);
264 static char     *doublequote(char *);
265 static int      *socksetup(int, char *, const char *);
266
267 int
268 main(int argc, char *argv[], char **envp)
269 {
270         socklen_t addrlen;
271         int ch, on = 1, tos, s = STDIN_FILENO;
272         char *cp, line[LINE_MAX];
273         FILE *fd;
274         char    *bindname = NULL;
275         const char *bindport = "ftp";
276         int     family = AF_UNSPEC;
277         struct sigaction sa;
278
279         tzset();                /* in case no timezone database in ~ftp */
280         sigemptyset(&sa.sa_mask);
281         sa.sa_flags = SA_RESTART;
282
283 #ifdef OLD_SETPROCTITLE
284         /*
285          *  Save start and extent of argv for setproctitle.
286          */
287         Argv = argv;
288         while (*envp)
289                 envp++;
290         LastArgv = envp[-1] + strlen(envp[-1]);
291 #endif /* OLD_SETPROCTITLE */
292
293         /*
294          * Prevent diagnostic messages from appearing on stderr.
295          * We run as a daemon or from inetd; in both cases, there's
296          * more reason in logging to syslog.
297          */
298         (void) freopen(_PATH_DEVNULL, "w", stderr);
299         opterr = 0;
300
301         /*
302          * LOG_NDELAY sets up the logging connection immediately,
303          * necessary for anonymous ftp's that chroot and can't do it later.
304          */
305         openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
306
307         while ((ch = getopt(argc, argv,
308                             "468a:ABdDEhlmMoOp:P:rRSt:T:u:UvW")) != -1) {
309                 switch (ch) {
310                 case '4':
311                         family = (family == AF_INET6) ? AF_UNSPEC : AF_INET;
312                         break;
313
314                 case '6':
315                         family = (family == AF_INET) ? AF_UNSPEC : AF_INET6;
316                         break;
317
318                 case '8':
319                         assumeutf8 = 1;
320                         break;
321
322                 case 'a':
323                         bindname = optarg;
324                         break;
325
326                 case 'A':
327                         anon_only = 1;
328                         break;
329
330                 case 'B':
331 #ifdef USE_BLACKLIST
332                         use_blacklist = 1;
333 #else
334                         syslog(LOG_WARNING, "not compiled with USE_BLACKLIST support");
335 #endif
336                         break;
337
338                 case 'd':
339                         ftpdebug++;
340                         break;
341
342                 case 'D':
343                         daemon_mode++;
344                         break;
345
346                 case 'E':
347                         noepsv = 1;
348                         break;
349
350                 case 'h':
351                         hostinfo = 0;
352                         break;
353
354                 case 'l':
355                         logging++;      /* > 1 == extra logging */
356                         break;
357
358                 case 'm':
359                         noguestmod = 0;
360                         break;
361
362                 case 'M':
363                         noguestmkd = 1;
364                         break;
365
366                 case 'o':
367                         noretr = 1;
368                         break;
369
370                 case 'O':
371                         noguestretr = 1;
372                         break;
373
374                 case 'p':
375                         pid_file = optarg;
376                         break;
377
378                 case 'P':
379                         bindport = optarg;
380                         break;
381
382                 case 'r':
383                         readonly = 1;
384                         break;
385
386                 case 'R':
387                         paranoid = 0;
388                         break;
389
390                 case 'S':
391                         stats++;
392                         break;
393
394                 case 't':
395                         timeout = atoi(optarg);
396                         if (maxtimeout < timeout)
397                                 maxtimeout = timeout;
398                         break;
399
400                 case 'T':
401                         maxtimeout = atoi(optarg);
402                         if (timeout > maxtimeout)
403                                 timeout = maxtimeout;
404                         break;
405
406                 case 'u':
407                     {
408                         long val = 0;
409
410                         val = strtol(optarg, &optarg, 8);
411                         if (*optarg != '\0' || val < 0)
412                                 syslog(LOG_WARNING, "bad value for -u");
413                         else
414                                 defumask = val;
415                         break;
416                     }
417                 case 'U':
418                         restricted_data_ports = 0;
419                         break;
420
421                 case 'v':
422                         ftpdebug++;
423                         break;
424
425                 case 'W':
426                         dowtmp = 0;
427                         break;
428
429                 default:
430                         syslog(LOG_WARNING, "unknown flag -%c ignored", optopt);
431                         break;
432                 }
433         }
434
435         /* handle filesize limit gracefully */
436         sa.sa_handler = SIG_IGN;
437         (void)sigaction(SIGXFSZ, &sa, NULL);
438
439         if (daemon_mode) {
440                 int *ctl_sock, fd, maxfd = -1, nfds, i;
441                 fd_set defreadfds, readfds;
442                 pid_t pid;
443                 struct pidfh *pfh;
444
445                 if ((pfh = pidfile_open(pid_file, 0600, &pid)) == NULL) {
446                         if (errno == EEXIST) {
447                                 syslog(LOG_ERR, "%s already running, pid %d",
448                                        getprogname(), (int)pid);
449                                 exit(1);
450                         }
451                         syslog(LOG_WARNING, "pidfile_open: %m");
452                 }
453
454                 /*
455                  * Detach from parent.
456                  */
457                 if (daemon(1, 1) < 0) {
458                         syslog(LOG_ERR, "failed to become a daemon");
459                         exit(1);
460                 }
461
462                 if (pfh != NULL && pidfile_write(pfh) == -1)
463                         syslog(LOG_WARNING, "pidfile_write: %m");
464
465                 sa.sa_handler = reapchild;
466                 (void)sigaction(SIGCHLD, &sa, NULL);
467
468 #ifdef VIRTUAL_HOSTING
469                 inithosts(family);
470 #endif
471
472                 /*
473                  * Open a socket, bind it to the FTP port, and start
474                  * listening.
475                  */
476                 ctl_sock = socksetup(family, bindname, bindport);
477                 if (ctl_sock == NULL)
478                         exit(1);
479
480                 FD_ZERO(&defreadfds);
481                 for (i = 1; i <= *ctl_sock; i++) {
482                         FD_SET(ctl_sock[i], &defreadfds);
483                         if (listen(ctl_sock[i], 32) < 0) {
484                                 syslog(LOG_ERR, "control listen: %m");
485                                 exit(1);
486                         }
487                         if (maxfd < ctl_sock[i])
488                                 maxfd = ctl_sock[i];
489                 }
490
491                 /*
492                  * Loop forever accepting connection requests and forking off
493                  * children to handle them.
494                  */
495                 while (1) {
496                         FD_COPY(&defreadfds, &readfds);
497                         nfds = select(maxfd + 1, &readfds, NULL, NULL, 0);
498                         if (nfds <= 0) {
499                                 if (nfds < 0 && errno != EINTR)
500                                         syslog(LOG_WARNING, "select: %m");
501                                 continue;
502                         }
503
504                         pid = -1;
505                         for (i = 1; i <= *ctl_sock; i++)
506                                 if (FD_ISSET(ctl_sock[i], &readfds)) {
507                                         addrlen = sizeof(his_addr);
508                                         fd = accept(ctl_sock[i],
509                                             (struct sockaddr *)&his_addr,
510                                             &addrlen);
511                                         if (fd == -1) {
512                                                 syslog(LOG_WARNING,
513                                                        "accept: %m");
514                                                 continue;
515                                         }
516                                         switch (pid = fork()) {
517                                         case 0:
518                                                 /* child */
519                                                 (void) dup2(fd, s);
520                                                 (void) dup2(fd, STDOUT_FILENO);
521                                                 (void) close(fd);
522                                                 for (i = 1; i <= *ctl_sock; i++)
523                                                         close(ctl_sock[i]);
524                                                 if (pfh != NULL)
525                                                         pidfile_close(pfh);
526                                                 goto gotchild;
527                                         case -1:
528                                                 syslog(LOG_WARNING, "fork: %m");
529                                                 /* FALLTHROUGH */
530                                         default:
531                                                 close(fd);
532                                         }
533                                 }
534                 }
535         } else {
536                 addrlen = sizeof(his_addr);
537                 if (getpeername(s, (struct sockaddr *)&his_addr, &addrlen) < 0) {
538                         syslog(LOG_ERR, "getpeername (%s): %m",argv[0]);
539                         exit(1);
540                 }
541
542 #ifdef VIRTUAL_HOSTING
543                 if (his_addr.su_family == AF_INET6 &&
544                     IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr))
545                         family = AF_INET;
546                 else
547                         family = his_addr.su_family;
548                 inithosts(family);
549 #endif
550         }
551
552 gotchild:
553         sa.sa_handler = SIG_DFL;
554         (void)sigaction(SIGCHLD, &sa, NULL);
555
556         sa.sa_handler = sigurg;
557         sa.sa_flags = 0;                /* don't restart syscalls for SIGURG */
558         (void)sigaction(SIGURG, &sa, NULL);
559
560         sigfillset(&sa.sa_mask);        /* block all signals in handler */
561         sa.sa_flags = SA_RESTART;
562         sa.sa_handler = sigquit;
563         (void)sigaction(SIGHUP, &sa, NULL);
564         (void)sigaction(SIGINT, &sa, NULL);
565         (void)sigaction(SIGQUIT, &sa, NULL);
566         (void)sigaction(SIGTERM, &sa, NULL);
567
568         sa.sa_handler = lostconn;
569         (void)sigaction(SIGPIPE, &sa, NULL);
570
571         addrlen = sizeof(ctrl_addr);
572         if (getsockname(s, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
573                 syslog(LOG_ERR, "getsockname (%s): %m",argv[0]);
574                 exit(1);
575         }
576         dataport = ntohs(ctrl_addr.su_port) - 1; /* as per RFC 959 */
577 #ifdef VIRTUAL_HOSTING
578         /* select our identity from virtual host table */
579         selecthost(&ctrl_addr);
580 #endif
581 #ifdef IP_TOS
582         if (ctrl_addr.su_family == AF_INET)
583       {
584         tos = IPTOS_LOWDELAY;
585         if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
586                 syslog(LOG_WARNING, "control setsockopt (IP_TOS): %m");
587       }
588 #endif
589         /*
590          * Disable Nagle on the control channel so that we don't have to wait
591          * for peer's ACK before issuing our next reply.
592          */
593         if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
594                 syslog(LOG_WARNING, "control setsockopt (TCP_NODELAY): %m");
595
596         data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
597
598         (void)snprintf(wtmpid, sizeof(wtmpid), "%xftpd", getpid());
599
600         /* Try to handle urgent data inline */
601 #ifdef SO_OOBINLINE
602         if (setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) < 0)
603                 syslog(LOG_WARNING, "control setsockopt (SO_OOBINLINE): %m");
604 #endif
605
606 #ifdef  F_SETOWN
607         if (fcntl(s, F_SETOWN, getpid()) == -1)
608                 syslog(LOG_ERR, "fcntl F_SETOWN: %m");
609 #endif
610         dolog((struct sockaddr *)&his_addr);
611         /*
612          * Set up default state
613          */
614         data = -1;
615         type = TYPE_A;
616         form = FORM_N;
617         stru = STRU_F;
618         mode = MODE_S;
619         tmpline[0] = '\0';
620
621         /* If logins are disabled, print out the message. */
622         if ((fd = fopen(_PATH_NOLOGIN,"r")) != NULL) {
623                 while (fgets(line, sizeof(line), fd) != NULL) {
624                         if ((cp = strchr(line, '\n')) != NULL)
625                                 *cp = '\0';
626                         lreply(530, "%s", line);
627                 }
628                 (void) fflush(stdout);
629                 (void) fclose(fd);
630                 reply(530, "System not available.");
631                 exit(0);
632         }
633 #ifdef VIRTUAL_HOSTING
634         fd = fopen(thishost->welcome, "r");
635 #else
636         fd = fopen(_PATH_FTPWELCOME, "r");
637 #endif
638         if (fd != NULL) {
639                 while (fgets(line, sizeof(line), fd) != NULL) {
640                         if ((cp = strchr(line, '\n')) != NULL)
641                                 *cp = '\0';
642                         lreply(220, "%s", line);
643                 }
644                 (void) fflush(stdout);
645                 (void) fclose(fd);
646                 /* reply(220,) must follow */
647         }
648 #ifndef VIRTUAL_HOSTING
649         if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
650                 fatalerror("Ran out of memory.");
651         if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
652                 hostname[0] = '\0';
653         hostname[MAXHOSTNAMELEN - 1] = '\0';
654 #endif
655         if (hostinfo)
656                 reply(220, "%s FTP server (%s) ready.", hostname, version);
657         else
658                 reply(220, "FTP server ready.");
659         BLACKLIST_INIT();
660         for (;;)
661                 (void) yyparse();
662         /* NOTREACHED */
663 }
664
665 static void
666 lostconn(int signo)
667 {
668
669         if (ftpdebug)
670                 syslog(LOG_DEBUG, "lost connection");
671         dologout(1);
672 }
673
674 static void
675 sigquit(int signo)
676 {
677
678         syslog(LOG_ERR, "got signal %d", signo);
679         dologout(1);
680 }
681
682 #ifdef VIRTUAL_HOSTING
683 /*
684  * read in virtual host tables (if they exist)
685  */
686
687 static void
688 inithosts(int family)
689 {
690         int insert;
691         size_t len;
692         FILE *fp;
693         char *cp, *mp, *line;
694         char *hostname;
695         char *vhost, *anonuser, *statfile, *welcome, *loginmsg;
696         struct ftphost *hrp, *lhrp;
697         struct addrinfo hints, *res, *ai;
698
699         /*
700          * Fill in the default host information
701          */
702         if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
703                 fatalerror("Ran out of memory.");
704         if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
705                 hostname[0] = '\0';
706         hostname[MAXHOSTNAMELEN - 1] = '\0';
707         if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
708                 fatalerror("Ran out of memory.");
709         hrp->hostname = hostname;
710         hrp->hostinfo = NULL;
711
712         memset(&hints, 0, sizeof(hints));
713         hints.ai_flags = AI_PASSIVE;
714         hints.ai_family = family;
715         hints.ai_socktype = SOCK_STREAM;
716         if (getaddrinfo(hrp->hostname, NULL, &hints, &res) == 0)
717                 hrp->hostinfo = res;
718         hrp->statfile = _PATH_FTPDSTATFILE;
719         hrp->welcome  = _PATH_FTPWELCOME;
720         hrp->loginmsg = _PATH_FTPLOGINMESG;
721         hrp->anonuser = "ftp";
722         hrp->next = NULL;
723         thishost = firsthost = lhrp = hrp;
724         if ((fp = fopen(_PATH_FTPHOSTS, "r")) != NULL) {
725                 int addrsize, gothost;
726                 void *addr;
727                 struct hostent *hp;
728
729                 while ((line = fgetln(fp, &len)) != NULL) {
730                         int     i, hp_error;
731
732                         /* skip comments */
733                         if (line[0] == '#')
734                                 continue;
735                         if (line[len - 1] == '\n') {
736                                 line[len - 1] = '\0';
737                                 mp = NULL;
738                         } else {
739                                 if ((mp = malloc(len + 1)) == NULL)
740                                         fatalerror("Ran out of memory.");
741                                 memcpy(mp, line, len);
742                                 mp[len] = '\0';
743                                 line = mp;
744                         }
745                         cp = strtok(line, " \t");
746                         /* skip empty lines */
747                         if (cp == NULL)
748                                 goto nextline;
749                         vhost = cp;
750
751                         /* set defaults */
752                         anonuser = "ftp";
753                         statfile = _PATH_FTPDSTATFILE;
754                         welcome  = _PATH_FTPWELCOME;
755                         loginmsg = _PATH_FTPLOGINMESG;
756
757                         /*
758                          * Preparse the line so we can use its info
759                          * for all the addresses associated with
760                          * the virtual host name.
761                          * Field 0, the virtual host name, is special:
762                          * it's already parsed off and will be strdup'ed
763                          * later, after we know its canonical form.
764                          */
765                         for (i = 1; i < 5 && (cp = strtok(NULL, " \t")); i++)
766                                 if (*cp != '-' && (cp = strdup(cp)))
767                                         switch (i) {
768                                         case 1: /* anon user permissions */
769                                                 anonuser = cp;
770                                                 break;
771                                         case 2: /* statistics file */
772                                                 statfile = cp;
773                                                 break;
774                                         case 3: /* welcome message */
775                                                 welcome  = cp;
776                                                 break;
777                                         case 4: /* login message */
778                                                 loginmsg = cp;
779                                                 break;
780                                         default: /* programming error */
781                                                 abort();
782                                                 /* NOTREACHED */
783                                         }
784
785                         hints.ai_flags = AI_PASSIVE;
786                         hints.ai_family = family;
787                         hints.ai_socktype = SOCK_STREAM;
788                         if (getaddrinfo(vhost, NULL, &hints, &res) != 0)
789                                 goto nextline;
790                         for (ai = res; ai != NULL && ai->ai_addr != NULL;
791                              ai = ai->ai_next) {
792
793                         gothost = 0;
794                         for (hrp = firsthost; hrp != NULL; hrp = hrp->next) {
795                                 struct addrinfo *hi;
796
797                                 for (hi = hrp->hostinfo; hi != NULL;
798                                      hi = hi->ai_next)
799                                         if (hi->ai_addrlen == ai->ai_addrlen &&
800                                             memcmp(hi->ai_addr,
801                                                    ai->ai_addr,
802                                                    ai->ai_addr->sa_len) == 0) {
803                                                 gothost++;
804                                                 break;
805                                         }
806                                 if (gothost)
807                                         break;
808                         }
809                         if (hrp == NULL) {
810                                 if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
811                                         goto nextline;
812                                 hrp->hostname = NULL;
813                                 insert = 1;
814                         } else {
815                                 if (hrp->hostinfo && hrp->hostinfo != res)
816                                         freeaddrinfo(hrp->hostinfo);
817                                 insert = 0; /* host already in the chain */
818                         }
819                         hrp->hostinfo = res;
820
821                         /*
822                          * determine hostname to use.
823                          * force defined name if there is a valid alias
824                          * otherwise fallback to primary hostname
825                          */
826                         /* XXX: getaddrinfo() can't do alias check */
827                         switch(hrp->hostinfo->ai_family) {
828                         case AF_INET:
829                                 addr = &((struct sockaddr_in *)hrp->hostinfo->ai_addr)->sin_addr;
830                                 addrsize = sizeof(struct in_addr);
831                                 break;
832                         case AF_INET6:
833                                 addr = &((struct sockaddr_in6 *)hrp->hostinfo->ai_addr)->sin6_addr;
834                                 addrsize = sizeof(struct in6_addr);
835                                 break;
836                         default:
837                                 /* should not reach here */
838                                 freeaddrinfo(hrp->hostinfo);
839                                 if (insert)
840                                         free(hrp); /*not in chain, can free*/
841                                 else
842                                         hrp->hostinfo = NULL; /*mark as blank*/
843                                 goto nextline;
844                                 /* NOTREACHED */
845                         }
846                         if ((hp = getipnodebyaddr(addr, addrsize,
847                                                   hrp->hostinfo->ai_family,
848                                                   &hp_error)) != NULL) {
849                                 if (strcmp(vhost, hp->h_name) != 0) {
850                                         if (hp->h_aliases == NULL)
851                                                 vhost = hp->h_name;
852                                         else {
853                                                 i = 0;
854                                                 while (hp->h_aliases[i] &&
855                                                        strcmp(vhost, hp->h_aliases[i]) != 0)
856                                                         ++i;
857                                                 if (hp->h_aliases[i] == NULL)
858                                                         vhost = hp->h_name;
859                                         }
860                                 }
861                         }
862                         if (hrp->hostname &&
863                             strcmp(hrp->hostname, vhost) != 0) {
864                                 free(hrp->hostname);
865                                 hrp->hostname = NULL;
866                         }
867                         if (hrp->hostname == NULL &&
868                             (hrp->hostname = strdup(vhost)) == NULL) {
869                                 freeaddrinfo(hrp->hostinfo);
870                                 hrp->hostinfo = NULL; /* mark as blank */
871                                 if (hp)
872                                         freehostent(hp);
873                                 goto nextline;
874                         }
875                         hrp->anonuser = anonuser;
876                         hrp->statfile = statfile;
877                         hrp->welcome  = welcome;
878                         hrp->loginmsg = loginmsg;
879                         if (insert) {
880                                 hrp->next  = NULL;
881                                 lhrp->next = hrp;
882                                 lhrp = hrp;
883                         }
884                         if (hp)
885                                 freehostent(hp);
886                       }
887 nextline:
888                         if (mp)
889                                 free(mp);
890                 }
891                 (void) fclose(fp);
892         }
893 }
894
895 static void
896 selecthost(union sockunion *su)
897 {
898         struct ftphost  *hrp;
899         u_int16_t port;
900 #ifdef INET6
901         struct in6_addr *mapped_in6 = NULL;
902 #endif
903         struct addrinfo *hi;
904
905 #ifdef INET6
906         /*
907          * XXX IPv4 mapped IPv6 addr consideraton,
908          * specified in rfc2373.
909          */
910         if (su->su_family == AF_INET6 &&
911             IN6_IS_ADDR_V4MAPPED(&su->su_sin6.sin6_addr))
912                 mapped_in6 = &su->su_sin6.sin6_addr;
913 #endif
914
915         hrp = thishost = firsthost;     /* default */
916         port = su->su_port;
917         su->su_port = 0;
918         while (hrp != NULL) {
919             for (hi = hrp->hostinfo; hi != NULL; hi = hi->ai_next) {
920                 if (memcmp(su, hi->ai_addr, hi->ai_addrlen) == 0) {
921                         thishost = hrp;
922                         goto found;
923                 }
924 #ifdef INET6
925                 /* XXX IPv4 mapped IPv6 addr consideraton */
926                 if (hi->ai_addr->sa_family == AF_INET && mapped_in6 != NULL &&
927                     (memcmp(&mapped_in6->s6_addr[12],
928                             &((struct sockaddr_in *)hi->ai_addr)->sin_addr,
929                             sizeof(struct in_addr)) == 0)) {
930                         thishost = hrp;
931                         goto found;
932                 }
933 #endif
934             }
935             hrp = hrp->next;
936         }
937 found:
938         su->su_port = port;
939         /* setup static variables as appropriate */
940         hostname = thishost->hostname;
941         ftpuser = thishost->anonuser;
942 }
943 #endif
944
945 /*
946  * Helper function for sgetpwnam().
947  */
948 static char *
949 sgetsave(char *s)
950 {
951         char *new = malloc(strlen(s) + 1);
952
953         if (new == NULL) {
954                 reply(421, "Ran out of memory.");
955                 dologout(1);
956                 /* NOTREACHED */
957         }
958         (void) strcpy(new, s);
959         return (new);
960 }
961
962 /*
963  * Save the result of a getpwnam.  Used for USER command, since
964  * the data returned must not be clobbered by any other command
965  * (e.g., globbing).
966  * NB: The data returned by sgetpwnam() will remain valid until
967  * the next call to this function.  Its difference from getpwnam()
968  * is that sgetpwnam() is known to be called from ftpd code only.
969  */
970 static struct passwd *
971 sgetpwnam(char *name)
972 {
973         static struct passwd save;
974         struct passwd *p;
975
976         if ((p = getpwnam(name)) == NULL)
977                 return (p);
978         if (save.pw_name) {
979                 free(save.pw_name);
980                 free(save.pw_passwd);
981                 free(save.pw_class);
982                 free(save.pw_gecos);
983                 free(save.pw_dir);
984                 free(save.pw_shell);
985         }
986         save = *p;
987         save.pw_name = sgetsave(p->pw_name);
988         save.pw_passwd = sgetsave(p->pw_passwd);
989         save.pw_class = sgetsave(p->pw_class);
990         save.pw_gecos = sgetsave(p->pw_gecos);
991         save.pw_dir = sgetsave(p->pw_dir);
992         save.pw_shell = sgetsave(p->pw_shell);
993         return (&save);
994 }
995
996 static int login_attempts;      /* number of failed login attempts */
997 static int askpasswd;           /* had user command, ask for passwd */
998 static char curname[MAXLOGNAME];        /* current USER name */
999
1000 /*
1001  * USER command.
1002  * Sets global passwd pointer pw if named account exists and is acceptable;
1003  * sets askpasswd if a PASS command is expected.  If logged in previously,
1004  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
1005  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
1006  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
1007  * requesting login privileges.  Disallow anyone who does not have a standard
1008  * shell as returned by getusershell().  Disallow anyone mentioned in the file
1009  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
1010  */
1011 void
1012 user(char *name)
1013 {
1014         int ecode;
1015         char *cp, *shell;
1016
1017         if (logged_in) {
1018                 if (guest) {
1019                         reply(530, "Can't change user from guest login.");
1020                         return;
1021                 } else if (dochroot) {
1022                         reply(530, "Can't change user from chroot user.");
1023                         return;
1024                 }
1025                 end_login();
1026         }
1027
1028         guest = 0;
1029 #ifdef VIRTUAL_HOSTING
1030         pw = sgetpwnam(thishost->anonuser);
1031 #else
1032         pw = sgetpwnam("ftp");
1033 #endif
1034         if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
1035                 if (checkuser(_PATH_FTPUSERS, "ftp", 0, NULL, &ecode) ||
1036                     (ecode != 0 && ecode != ENOENT))
1037                         reply(530, "User %s access denied.", name);
1038                 else if (checkuser(_PATH_FTPUSERS, "anonymous", 0, NULL, &ecode) ||
1039                     (ecode != 0 && ecode != ENOENT))
1040                         reply(530, "User %s access denied.", name);
1041                 else if (pw != NULL) {
1042                         guest = 1;
1043                         askpasswd = 1;
1044                         reply(331,
1045                         "Guest login ok, send your email address as password.");
1046                 } else
1047                         reply(530, "User %s unknown.", name);
1048                 if (!askpasswd && logging)
1049                         syslog(LOG_NOTICE,
1050                             "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
1051                 return;
1052         }
1053         if (anon_only != 0) {
1054                 reply(530, "Sorry, only anonymous ftp allowed.");
1055                 return;
1056         }
1057                 
1058         if ((pw = sgetpwnam(name))) {
1059                 if ((shell = pw->pw_shell) == NULL || *shell == 0)
1060                         shell = _PATH_BSHELL;
1061                 setusershell();
1062                 while ((cp = getusershell()) != NULL)
1063                         if (strcmp(cp, shell) == 0)
1064                                 break;
1065                 endusershell();
1066
1067                 if (cp == NULL || 
1068                     (checkuser(_PATH_FTPUSERS, name, 1, NULL, &ecode) ||
1069                     (ecode != 0 && ecode != ENOENT))) {
1070                         reply(530, "User %s access denied.", name);
1071                         if (logging)
1072                                 syslog(LOG_NOTICE,
1073                                     "FTP LOGIN REFUSED FROM %s, %s",
1074                                     remotehost, name);
1075                         pw = NULL;
1076                         return;
1077                 }
1078         }
1079         if (logging)
1080                 strlcpy(curname, name, sizeof(curname));
1081
1082         pwok = 0;
1083 #ifdef USE_PAM
1084         /* XXX Kluge! The conversation mechanism needs to be fixed. */
1085 #endif
1086         if (opiechallenge(&opiedata, name, opieprompt) == 0) {
1087                 pwok = (pw != NULL) &&
1088                        opieaccessfile(remotehost) &&
1089                        opiealways(pw->pw_dir);
1090                 reply(331, "Response to %s %s for %s.",
1091                       opieprompt, pwok ? "requested" : "required", name);
1092         } else {
1093                 pwok = 1;
1094                 reply(331, "Password required for %s.", name);
1095         }
1096         askpasswd = 1;
1097         /*
1098          * Delay before reading passwd after first failed
1099          * attempt to slow down passwd-guessing programs.
1100          */
1101         if (login_attempts)
1102                 sleep(login_attempts);
1103 }
1104
1105 /*
1106  * Check if a user is in the file "fname",
1107  * return a pointer to a malloc'd string with the rest
1108  * of the matching line in "residue" if not NULL.
1109  */
1110 static int
1111 checkuser(char *fname, char *name, int pwset, char **residue, int *ecode)
1112 {
1113         FILE *fd;
1114         int found = 0;
1115         size_t len;
1116         char *line, *mp, *p;
1117
1118         if (ecode != NULL)
1119                 *ecode = 0;
1120         if ((fd = fopen(fname, "r")) != NULL) {
1121                 while (!found && (line = fgetln(fd, &len)) != NULL) {
1122                         /* skip comments */
1123                         if (line[0] == '#')
1124                                 continue;
1125                         if (line[len - 1] == '\n') {
1126                                 line[len - 1] = '\0';
1127                                 mp = NULL;
1128                         } else {
1129                                 if ((mp = malloc(len + 1)) == NULL)
1130                                         fatalerror("Ran out of memory.");
1131                                 memcpy(mp, line, len);
1132                                 mp[len] = '\0';
1133                                 line = mp;
1134                         }
1135                         /* avoid possible leading and trailing whitespace */
1136                         p = strtok(line, " \t");
1137                         /* skip empty lines */
1138                         if (p == NULL)
1139                                 goto nextline;
1140                         /*
1141                          * if first chr is '@', check group membership
1142                          */
1143                         if (p[0] == '@') {
1144                                 int i = 0;
1145                                 struct group *grp;
1146
1147                                 if (p[1] == '\0') /* single @ matches anyone */
1148                                         found = 1;
1149                                 else {
1150                                         if ((grp = getgrnam(p+1)) == NULL)
1151                                                 goto nextline;
1152                                         /*
1153                                          * Check user's default group
1154                                          */
1155                                         if (pwset && grp->gr_gid == pw->pw_gid)
1156                                                 found = 1;
1157                                         /*
1158                                          * Check supplementary groups
1159                                          */
1160                                         while (!found && grp->gr_mem[i])
1161                                                 found = strcmp(name,
1162                                                         grp->gr_mem[i++])
1163                                                         == 0;
1164                                 }
1165                         }
1166                         /*
1167                          * Otherwise, just check for username match
1168                          */
1169                         else
1170                                 found = strcmp(p, name) == 0;
1171                         /*
1172                          * Save the rest of line to "residue" if matched
1173                          */
1174                         if (found && residue) {
1175                                 if ((p = strtok(NULL, "")) != NULL)
1176                                         p += strspn(p, " \t");
1177                                 if (p && *p) {
1178                                         if ((*residue = strdup(p)) == NULL)
1179                                                 fatalerror("Ran out of memory.");
1180                                 } else
1181                                         *residue = NULL;
1182                         }
1183 nextline:
1184                         if (mp)
1185                                 free(mp);
1186                 }
1187                 (void) fclose(fd);
1188         } else if (ecode != NULL)
1189                 *ecode = errno;
1190         return (found);
1191 }
1192
1193 /*
1194  * Terminate login as previous user, if any, resetting state;
1195  * used when USER command is given or login fails.
1196  */
1197 static void
1198 end_login(void)
1199 {
1200 #ifdef USE_PAM
1201         int e;
1202 #endif
1203
1204         (void) seteuid(0);
1205 #ifdef  LOGIN_CAP
1206         setusercontext(NULL, getpwuid(0), 0, LOGIN_SETALL & ~(LOGIN_SETLOGIN |
1207                        LOGIN_SETUSER | LOGIN_SETGROUP | LOGIN_SETPATH |
1208                        LOGIN_SETENV));
1209 #endif
1210         if (logged_in && dowtmp)
1211                 ftpd_logwtmp(wtmpid, NULL, NULL);
1212         pw = NULL;
1213 #ifdef USE_PAM
1214         if (pamh) {
1215                 if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS)
1216                         syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1217                 if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS)
1218                         syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e));
1219                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS)
1220                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1221                 pamh = NULL;
1222         }
1223 #endif
1224         logged_in = 0;
1225         guest = 0;
1226         dochroot = 0;
1227 }
1228
1229 #ifdef USE_PAM
1230
1231 /*
1232  * the following code is stolen from imap-uw PAM authentication module and
1233  * login.c
1234  */
1235 #define COPY_STRING(s) (s ? strdup(s) : NULL)
1236
1237 struct cred_t {
1238         const char *uname;              /* user name */
1239         const char *pass;               /* password */
1240 };
1241 typedef struct cred_t cred_t;
1242
1243 static int
1244 auth_conv(int num_msg, const struct pam_message **msg,
1245           struct pam_response **resp, void *appdata)
1246 {
1247         int i;
1248         cred_t *cred = (cred_t *) appdata;
1249         struct pam_response *reply;
1250
1251         reply = calloc(num_msg, sizeof *reply);
1252         if (reply == NULL)
1253                 return PAM_BUF_ERR;
1254
1255         for (i = 0; i < num_msg; i++) {
1256                 switch (msg[i]->msg_style) {
1257                 case PAM_PROMPT_ECHO_ON:        /* assume want user name */
1258                         reply[i].resp_retcode = PAM_SUCCESS;
1259                         reply[i].resp = COPY_STRING(cred->uname);
1260                         /* PAM frees resp. */
1261                         break;
1262                 case PAM_PROMPT_ECHO_OFF:       /* assume want password */
1263                         reply[i].resp_retcode = PAM_SUCCESS;
1264                         reply[i].resp = COPY_STRING(cred->pass);
1265                         /* PAM frees resp. */
1266                         break;
1267                 case PAM_TEXT_INFO:
1268                 case PAM_ERROR_MSG:
1269                         reply[i].resp_retcode = PAM_SUCCESS;
1270                         reply[i].resp = NULL;
1271                         break;
1272                 default:                        /* unknown message style */
1273                         free(reply);
1274                         return PAM_CONV_ERR;
1275                 }
1276         }
1277
1278         *resp = reply;
1279         return PAM_SUCCESS;
1280 }
1281
1282 /*
1283  * Attempt to authenticate the user using PAM.  Returns 0 if the user is
1284  * authenticated, or 1 if not authenticated.  If some sort of PAM system
1285  * error occurs (e.g., the "/etc/pam.conf" file is missing) then this
1286  * function returns -1.  This can be used as an indication that we should
1287  * fall back to a different authentication mechanism.
1288  */
1289 static int
1290 auth_pam(struct passwd **ppw, const char *pass)
1291 {
1292         const char *tmpl_user;
1293         const void *item;
1294         int rval;
1295         int e;
1296         cred_t auth_cred = { (*ppw)->pw_name, pass };
1297         struct pam_conv conv = { &auth_conv, &auth_cred };
1298
1299         e = pam_start("ftpd", (*ppw)->pw_name, &conv, &pamh);
1300         if (e != PAM_SUCCESS) {
1301                 /*
1302                  * In OpenPAM, it's OK to pass NULL to pam_strerror()
1303                  * if context creation has failed in the first place.
1304                  */
1305                 syslog(LOG_ERR, "pam_start: %s", pam_strerror(NULL, e));
1306                 return -1;
1307         }
1308
1309         e = pam_set_item(pamh, PAM_RHOST, remotehost);
1310         if (e != PAM_SUCCESS) {
1311                 syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
1312                         pam_strerror(pamh, e));
1313                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1314                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1315                 }
1316                 pamh = NULL;
1317                 return -1;
1318         }
1319
1320         e = pam_authenticate(pamh, 0);
1321         switch (e) {
1322         case PAM_SUCCESS:
1323                 /*
1324                  * With PAM we support the concept of a "template"
1325                  * user.  The user enters a login name which is
1326                  * authenticated by PAM, usually via a remote service
1327                  * such as RADIUS or TACACS+.  If authentication
1328                  * succeeds, a different but related "template" name
1329                  * is used for setting the credentials, shell, and
1330                  * home directory.  The name the user enters need only
1331                  * exist on the remote authentication server, but the
1332                  * template name must be present in the local password
1333                  * database.
1334                  *
1335                  * This is supported by two various mechanisms in the
1336                  * individual modules.  However, from the application's
1337                  * point of view, the template user is always passed
1338                  * back as a changed value of the PAM_USER item.
1339                  */
1340                 if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
1341                     PAM_SUCCESS) {
1342                         tmpl_user = (const char *) item;
1343                         if (strcmp((*ppw)->pw_name, tmpl_user) != 0)
1344                                 *ppw = getpwnam(tmpl_user);
1345                 } else
1346                         syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
1347                             pam_strerror(pamh, e));
1348                 rval = 0;
1349                 break;
1350
1351         case PAM_AUTH_ERR:
1352         case PAM_USER_UNKNOWN:
1353         case PAM_MAXTRIES:
1354                 rval = 1;
1355                 break;
1356
1357         default:
1358                 syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e));
1359                 rval = -1;
1360                 break;
1361         }
1362
1363         if (rval == 0) {
1364                 e = pam_acct_mgmt(pamh, 0);
1365                 if (e != PAM_SUCCESS) {
1366                         syslog(LOG_ERR, "pam_acct_mgmt: %s",
1367                                                 pam_strerror(pamh, e));
1368                         rval = 1;
1369                 }
1370         }
1371
1372         if (rval != 0) {
1373                 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1374                         syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1375                 }
1376                 pamh = NULL;
1377         }
1378         return rval;
1379 }
1380
1381 #endif /* USE_PAM */
1382
1383 void
1384 pass(char *passwd)
1385 {
1386         int rval, ecode;
1387         FILE *fd;
1388 #ifdef  LOGIN_CAP
1389         login_cap_t *lc = NULL;
1390 #endif
1391 #ifdef USE_PAM
1392         int e;
1393 #endif
1394         char *residue = NULL;
1395         char *xpasswd;
1396
1397         if (logged_in || askpasswd == 0) {
1398                 reply(503, "Login with USER first.");
1399                 return;
1400         }
1401         askpasswd = 0;
1402         if (!guest) {           /* "ftp" is only account allowed no password */
1403                 if (pw == NULL) {
1404                         rval = 1;       /* failure below */
1405                         goto skip;
1406                 }
1407 #ifdef USE_PAM
1408                 rval = auth_pam(&pw, passwd);
1409                 if (rval >= 0) {
1410                         opieunlock();
1411                         goto skip;
1412                 }
1413 #endif
1414                 if (opieverify(&opiedata, passwd) == 0)
1415                         xpasswd = pw->pw_passwd;
1416                 else if (pwok) {
1417                         xpasswd = crypt(passwd, pw->pw_passwd);
1418                         if (passwd[0] == '\0' && pw->pw_passwd[0] != '\0')
1419                                 xpasswd = ":";
1420                 } else {
1421                         rval = 1;
1422                         goto skip;
1423                 }
1424                 rval = strcmp(pw->pw_passwd, xpasswd);
1425                 if (pw->pw_expire && time(NULL) >= pw->pw_expire)
1426                         rval = 1;       /* failure */
1427 skip:
1428                 /*
1429                  * If rval == 1, the user failed the authentication check
1430                  * above.  If rval == 0, either PAM or local authentication
1431                  * succeeded.
1432                  */
1433                 if (rval) {
1434                         reply(530, "Login incorrect.");
1435                         BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL, STDIN_FILENO, "Login incorrect");
1436                         if (logging) {
1437                                 syslog(LOG_NOTICE,
1438                                     "FTP LOGIN FAILED FROM %s",
1439                                     remotehost);
1440                                 syslog(LOG_AUTHPRIV | LOG_NOTICE,
1441                                     "FTP LOGIN FAILED FROM %s, %s",
1442                                     remotehost, curname);
1443                         }
1444                         pw = NULL;
1445                         if (login_attempts++ >= 5) {
1446                                 syslog(LOG_NOTICE,
1447                                     "repeated login failures from %s",
1448                                     remotehost);
1449                                 exit(0);
1450                         }
1451                         return;
1452                 } else {
1453                         BLACKLIST_NOTIFY(BLACKLIST_AUTH_OK, STDIN_FILENO, "Login successful");
1454                 }
1455         }
1456         login_attempts = 0;             /* this time successful */
1457         if (setegid(pw->pw_gid) < 0) {
1458                 reply(550, "Can't set gid.");
1459                 return;
1460         }
1461         /* May be overridden by login.conf */
1462         (void) umask(defumask);
1463 #ifdef  LOGIN_CAP
1464         if ((lc = login_getpwclass(pw)) != NULL) {
1465                 char    remote_ip[NI_MAXHOST];
1466
1467                 if (getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1468                         remote_ip, sizeof(remote_ip) - 1, NULL, 0,
1469                         NI_NUMERICHOST))
1470                                 *remote_ip = 0;
1471                 remote_ip[sizeof(remote_ip) - 1] = 0;
1472                 if (!auth_hostok(lc, remotehost, remote_ip)) {
1473                         syslog(LOG_INFO|LOG_AUTH,
1474                             "FTP LOGIN FAILED (HOST) as %s: permission denied.",
1475                             pw->pw_name);
1476                         reply(530, "Permission denied.");
1477                         pw = NULL;
1478                         return;
1479                 }
1480                 if (!auth_timeok(lc, time(NULL))) {
1481                         reply(530, "Login not available right now.");
1482                         pw = NULL;
1483                         return;
1484                 }
1485         }
1486         setusercontext(lc, pw, 0, LOGIN_SETALL &
1487                        ~(LOGIN_SETRESOURCES | LOGIN_SETUSER | LOGIN_SETPATH | LOGIN_SETENV));
1488 #else
1489         setlogin(pw->pw_name);
1490         (void) initgroups(pw->pw_name, pw->pw_gid);
1491 #endif
1492
1493 #ifdef USE_PAM
1494         if (pamh) {
1495                 if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
1496                         syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, e));
1497                 } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
1498                         syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1499                 }
1500         }
1501 #endif
1502
1503         dochroot =
1504                 checkuser(_PATH_FTPCHROOT, pw->pw_name, 1, &residue, &ecode)
1505 #ifdef  LOGIN_CAP       /* Allow login.conf configuration as well */
1506                 || login_getcapbool(lc, "ftp-chroot", 0)
1507 #endif
1508         ;
1509         /*
1510          * It is possible that checkuser() failed to open the chroot file.
1511          * If this is the case, report that logins are un-available, since we
1512          * have no way of checking whether or not the user should be chrooted.
1513          * We ignore ENOENT since it is not required that this file be present.
1514          */
1515         if (ecode != 0 && ecode != ENOENT) {
1516                 reply(530, "Login not available right now.");
1517                 return;
1518         }
1519         chrootdir = NULL;
1520
1521         /* Disable wtmp logging when chrooting. */
1522         if (dochroot || guest)
1523                 dowtmp = 0;
1524         if (dowtmp)
1525                 ftpd_logwtmp(wtmpid, pw->pw_name,
1526                     (struct sockaddr *)&his_addr);
1527         logged_in = 1;
1528
1529 #ifdef  LOGIN_CAP
1530         setusercontext(lc, pw, 0, LOGIN_SETRESOURCES);
1531 #endif
1532
1533         if (guest && stats && statfd < 0)
1534 #ifdef VIRTUAL_HOSTING
1535                 statfd = open(thishost->statfile, O_WRONLY|O_APPEND);
1536 #else
1537                 statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND);
1538 #endif
1539                 if (statfd < 0)
1540                         stats = 0;
1541
1542         /*
1543          * For a chrooted local user,
1544          * a) see whether ftpchroot(5) specifies a chroot directory,
1545          * b) extract the directory pathname from the line,
1546          * c) expand it to the absolute pathname if necessary.
1547          */
1548         if (dochroot && residue &&
1549             (chrootdir = strtok(residue, " \t")) != NULL) {
1550                 if (chrootdir[0] != '/')
1551                         asprintf(&chrootdir, "%s/%s", pw->pw_dir, chrootdir);
1552                 else
1553                         chrootdir = strdup(chrootdir); /* make it permanent */
1554                 if (chrootdir == NULL)
1555                         fatalerror("Ran out of memory.");
1556         }
1557         if (guest || dochroot) {
1558                 /*
1559                  * If no chroot directory set yet, use the login directory.
1560                  * Copy it so it can be modified while pw->pw_dir stays intact.
1561                  */
1562                 if (chrootdir == NULL &&
1563                     (chrootdir = strdup(pw->pw_dir)) == NULL)
1564                         fatalerror("Ran out of memory.");
1565                 /*
1566                  * Check for the "/chroot/./home" syntax,
1567                  * separate the chroot and home directory pathnames.
1568                  */
1569                 if ((homedir = strstr(chrootdir, "/./")) != NULL) {
1570                         *(homedir++) = '\0';    /* wipe '/' */
1571                         homedir++;              /* skip '.' */
1572                 } else {
1573                         /*
1574                          * We MUST do a chdir() after the chroot. Otherwise
1575                          * the old current directory will be accessible as "."
1576                          * outside the new root!
1577                          */
1578                         homedir = "/";
1579                 }
1580                 /*
1581                  * Finally, do chroot()
1582                  */
1583                 if (chroot(chrootdir) < 0) {
1584                         reply(550, "Can't change root.");
1585                         goto bad;
1586                 }
1587                 __FreeBSD_libc_enter_restricted_mode();
1588         } else  /* real user w/o chroot */
1589                 homedir = pw->pw_dir;
1590         /*
1591          * Set euid *before* doing chdir() so
1592          * a) the user won't be carried to a directory that he couldn't reach
1593          *    on his own due to no permission to upper path components,
1594          * b) NFS mounted homedirs w/restrictive permissions will be accessible
1595          *    (uid 0 has no root power over NFS if not mapped explicitly.)
1596          */
1597         if (seteuid(pw->pw_uid) < 0) {
1598                 reply(550, "Can't set uid.");
1599                 goto bad;
1600         }
1601         if (chdir(homedir) < 0) {
1602                 if (guest || dochroot) {
1603                         reply(550, "Can't change to base directory.");
1604                         goto bad;
1605                 } else {
1606                         if (chdir("/") < 0) {
1607                                 reply(550, "Root is inaccessible.");
1608                                 goto bad;
1609                         }
1610                         lreply(230, "No directory! Logging in with home=/.");
1611                 }
1612         }
1613
1614         /*
1615          * Display a login message, if it exists.
1616          * N.B. reply(230,) must follow the message.
1617          */
1618 #ifdef VIRTUAL_HOSTING
1619         fd = fopen(thishost->loginmsg, "r");
1620 #else
1621         fd = fopen(_PATH_FTPLOGINMESG, "r");
1622 #endif
1623         if (fd != NULL) {
1624                 char *cp, line[LINE_MAX];
1625
1626                 while (fgets(line, sizeof(line), fd) != NULL) {
1627                         if ((cp = strchr(line, '\n')) != NULL)
1628                                 *cp = '\0';
1629                         lreply(230, "%s", line);
1630                 }
1631                 (void) fflush(stdout);
1632                 (void) fclose(fd);
1633         }
1634         if (guest) {
1635                 if (ident != NULL)
1636                         free(ident);
1637                 ident = strdup(passwd);
1638                 if (ident == NULL)
1639                         fatalerror("Ran out of memory.");
1640
1641                 reply(230, "Guest login ok, access restrictions apply.");
1642 #ifdef SETPROCTITLE
1643 #ifdef VIRTUAL_HOSTING
1644                 if (thishost != firsthost)
1645                         snprintf(proctitle, sizeof(proctitle),
1646                                  "%s: anonymous(%s)/%s", remotehost, hostname,
1647                                  passwd);
1648                 else
1649 #endif
1650                         snprintf(proctitle, sizeof(proctitle),
1651                                  "%s: anonymous/%s", remotehost, passwd);
1652                 setproctitle("%s", proctitle);
1653 #endif /* SETPROCTITLE */
1654                 if (logging)
1655                         syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1656                             remotehost, passwd);
1657         } else {
1658                 if (dochroot)
1659                         reply(230, "User %s logged in, "
1660                                    "access restrictions apply.", pw->pw_name);
1661                 else
1662                         reply(230, "User %s logged in.", pw->pw_name);
1663
1664 #ifdef SETPROCTITLE
1665                 snprintf(proctitle, sizeof(proctitle),
1666                          "%s: user/%s", remotehost, pw->pw_name);
1667                 setproctitle("%s", proctitle);
1668 #endif /* SETPROCTITLE */
1669                 if (logging)
1670                         syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1671                             remotehost, pw->pw_name);
1672         }
1673         if (logging && (guest || dochroot))
1674                 syslog(LOG_INFO, "session root changed to %s", chrootdir);
1675 #ifdef  LOGIN_CAP
1676         login_close(lc);
1677 #endif
1678         if (residue)
1679                 free(residue);
1680         return;
1681 bad:
1682         /* Forget all about it... */
1683 #ifdef  LOGIN_CAP
1684         login_close(lc);
1685 #endif
1686         if (residue)
1687                 free(residue);
1688         end_login();
1689 }
1690
1691 void
1692 retrieve(char *cmd, char *name)
1693 {
1694         FILE *fin, *dout;
1695         struct stat st;
1696         int (*closefunc)(FILE *);
1697         time_t start;
1698         char line[BUFSIZ];
1699
1700         if (cmd == 0) {
1701                 fin = fopen(name, "r"), closefunc = fclose;
1702                 st.st_size = 0;
1703         } else {
1704                 (void) snprintf(line, sizeof(line), cmd, name);
1705                 name = line;
1706                 fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1707                 st.st_size = -1;
1708                 st.st_blksize = BUFSIZ;
1709         }
1710         if (fin == NULL) {
1711                 if (errno != 0) {
1712                         perror_reply(550, name);
1713                         if (cmd == 0) {
1714                                 LOGCMD("get", name);
1715                         }
1716                 }
1717                 return;
1718         }
1719         byte_count = -1;
1720         if (cmd == 0) {
1721                 if (fstat(fileno(fin), &st) < 0) {
1722                         perror_reply(550, name);
1723                         goto done;
1724                 }
1725                 if (!S_ISREG(st.st_mode)) {
1726                         /*
1727                          * Never sending a raw directory is a workaround
1728                          * for buggy clients that will attempt to RETR
1729                          * a directory before listing it, e.g., Mozilla.
1730                          * Preventing a guest from getting irregular files
1731                          * is a simple security measure.
1732                          */
1733                         if (S_ISDIR(st.st_mode) || guest) {
1734                                 reply(550, "%s: not a plain file.", name);
1735                                 goto done;
1736                         }
1737                         st.st_size = -1;
1738                         /* st.st_blksize is set for all descriptor types */
1739                 }
1740         }
1741         if (restart_point) {
1742                 if (type == TYPE_A) {
1743                         off_t i, n;
1744                         int c;
1745
1746                         n = restart_point;
1747                         i = 0;
1748                         while (i++ < n) {
1749                                 if ((c=getc(fin)) == EOF) {
1750                                         perror_reply(550, name);
1751                                         goto done;
1752                                 }
1753                                 if (c == '\n')
1754                                         i++;
1755                         }
1756                 } else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
1757                         perror_reply(550, name);
1758                         goto done;
1759                 }
1760         }
1761         dout = dataconn(name, st.st_size, "w");
1762         if (dout == NULL)
1763                 goto done;
1764         time(&start);
1765         send_data(fin, dout, st.st_blksize, st.st_size,
1766                   restart_point == 0 && cmd == 0 && S_ISREG(st.st_mode));
1767         if (cmd == 0 && guest && stats && byte_count > 0)
1768                 logxfer(name, byte_count, start);
1769         (void) fclose(dout);
1770         data = -1;
1771         pdata = -1;
1772 done:
1773         if (cmd == 0)
1774                 LOGBYTES("get", name, byte_count);
1775         (*closefunc)(fin);
1776 }
1777
1778 void
1779 store(char *name, char *mode, int unique)
1780 {
1781         int fd;
1782         FILE *fout, *din;
1783         int (*closefunc)(FILE *);
1784
1785         if (*mode == 'a') {             /* APPE */
1786                 if (unique) {
1787                         /* Programming error */
1788                         syslog(LOG_ERR, "Internal: unique flag to APPE");
1789                         unique = 0;
1790                 }
1791                 if (guest && noguestmod) {
1792                         reply(550, "Appending to existing file denied.");
1793                         goto err;
1794                 }
1795                 restart_point = 0;      /* not affected by preceding REST */
1796         }
1797         if (unique)                     /* STOU overrides REST */
1798                 restart_point = 0;
1799         if (guest && noguestmod) {
1800                 if (restart_point) {    /* guest STOR w/REST */
1801                         reply(550, "Modifying existing file denied.");
1802                         goto err;
1803                 } else                  /* treat guest STOR as STOU */
1804                         unique = 1;
1805         }
1806
1807         if (restart_point)
1808                 mode = "r+";    /* so ASCII manual seek can work */
1809         if (unique) {
1810                 if ((fd = guniquefd(name, &name)) < 0)
1811                         goto err;
1812                 fout = fdopen(fd, mode);
1813         } else
1814                 fout = fopen(name, mode);
1815         closefunc = fclose;
1816         if (fout == NULL) {
1817                 perror_reply(553, name);
1818                 goto err;
1819         }
1820         byte_count = -1;
1821         if (restart_point) {
1822                 if (type == TYPE_A) {
1823                         off_t i, n;
1824                         int c;
1825
1826                         n = restart_point;
1827                         i = 0;
1828                         while (i++ < n) {
1829                                 if ((c=getc(fout)) == EOF) {
1830                                         perror_reply(550, name);
1831                                         goto done;
1832                                 }
1833                                 if (c == '\n')
1834                                         i++;
1835                         }
1836                         /*
1837                          * We must do this seek to "current" position
1838                          * because we are changing from reading to
1839                          * writing.
1840                          */
1841                         if (fseeko(fout, 0, SEEK_CUR) < 0) {
1842                                 perror_reply(550, name);
1843                                 goto done;
1844                         }
1845                 } else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
1846                         perror_reply(550, name);
1847                         goto done;
1848                 }
1849         }
1850         din = dataconn(name, -1, "r");
1851         if (din == NULL)
1852                 goto done;
1853         if (receive_data(din, fout) == 0) {
1854                 if (unique)
1855                         reply(226, "Transfer complete (unique file name:%s).",
1856                             name);
1857                 else
1858                         reply(226, "Transfer complete.");
1859         }
1860         (void) fclose(din);
1861         data = -1;
1862         pdata = -1;
1863 done:
1864         LOGBYTES(*mode == 'a' ? "append" : "put", name, byte_count);
1865         (*closefunc)(fout);
1866         return;
1867 err:
1868         LOGCMD(*mode == 'a' ? "append" : "put" , name);
1869         return;
1870 }
1871
1872 static FILE *
1873 getdatasock(char *mode)
1874 {
1875         int on = 1, s, t, tries;
1876
1877         if (data >= 0)
1878                 return (fdopen(data, mode));
1879
1880         s = socket(data_dest.su_family, SOCK_STREAM, 0);
1881         if (s < 0)
1882                 goto bad;
1883         if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
1884                 syslog(LOG_WARNING, "data setsockopt (SO_REUSEADDR): %m");
1885         /* anchor socket to avoid multi-homing problems */
1886         data_source = ctrl_addr;
1887         data_source.su_port = htons(dataport);
1888         (void) seteuid(0);
1889         for (tries = 1; ; tries++) {
1890                 /*
1891                  * We should loop here since it's possible that
1892                  * another ftpd instance has passed this point and is
1893                  * trying to open a data connection in active mode now.
1894                  * Until the other connection is opened, we'll be getting
1895                  * EADDRINUSE because no SOCK_STREAM sockets in the system
1896                  * can share both local and remote addresses, localIP:20
1897                  * and *:* in this case.
1898                  */
1899                 if (bind(s, (struct sockaddr *)&data_source,
1900                     data_source.su_len) >= 0)
1901                         break;
1902                 if (errno != EADDRINUSE || tries > 10)
1903                         goto bad;
1904                 sleep(tries);
1905         }
1906         (void) seteuid(pw->pw_uid);
1907 #ifdef IP_TOS
1908         if (data_source.su_family == AF_INET)
1909       {
1910         on = IPTOS_THROUGHPUT;
1911         if (setsockopt(s, IPPROTO_IP, IP_TOS, &on, sizeof(int)) < 0)
1912                 syslog(LOG_WARNING, "data setsockopt (IP_TOS): %m");
1913       }
1914 #endif
1915 #ifdef TCP_NOPUSH
1916         /*
1917          * Turn off push flag to keep sender TCP from sending short packets
1918          * at the boundaries of each write().
1919          */
1920         on = 1;
1921         if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof on) < 0)
1922                 syslog(LOG_WARNING, "data setsockopt (TCP_NOPUSH): %m");
1923 #endif
1924         return (fdopen(s, mode));
1925 bad:
1926         /* Return the real value of errno (close may change it) */
1927         t = errno;
1928         (void) seteuid(pw->pw_uid);
1929         (void) close(s);
1930         errno = t;
1931         return (NULL);
1932 }
1933
1934 static FILE *
1935 dataconn(char *name, off_t size, char *mode)
1936 {
1937         char sizebuf[32];
1938         FILE *file;
1939         int retry = 0, tos, conerrno;
1940
1941         file_size = size;
1942         byte_count = 0;
1943         if (size != -1)
1944                 (void) snprintf(sizebuf, sizeof(sizebuf),
1945                                 " (%jd bytes)", (intmax_t)size);
1946         else
1947                 *sizebuf = '\0';
1948         if (pdata >= 0) {
1949                 union sockunion from;
1950                 socklen_t fromlen = ctrl_addr.su_len;
1951                 int flags, s;
1952                 struct timeval timeout;
1953                 fd_set set;
1954
1955                 FD_ZERO(&set);
1956                 FD_SET(pdata, &set);
1957
1958                 timeout.tv_usec = 0;
1959                 timeout.tv_sec = 120;
1960
1961                 /*
1962                  * Granted a socket is in the blocking I/O mode,
1963                  * accept() will block after a successful select()
1964                  * if the selected connection dies in between.
1965                  * Therefore set the non-blocking I/O flag here.
1966                  */
1967                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1968                     fcntl(pdata, F_SETFL, flags | O_NONBLOCK) == -1)
1969                         goto pdata_err;
1970                 if (select(pdata+1, &set, NULL, NULL, &timeout) <= 0 ||
1971                     (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0)
1972                         goto pdata_err;
1973                 (void) close(pdata);
1974                 pdata = s;
1975                 /*
1976                  * Unset the inherited non-blocking I/O flag
1977                  * on the child socket so stdio can work on it.
1978                  */
1979                 if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1980                     fcntl(pdata, F_SETFL, flags & ~O_NONBLOCK) == -1)
1981                         goto pdata_err;
1982 #ifdef IP_TOS
1983                 if (from.su_family == AF_INET)
1984               {
1985                 tos = IPTOS_THROUGHPUT;
1986                 if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
1987                         syslog(LOG_WARNING, "pdata setsockopt (IP_TOS): %m");
1988               }
1989 #endif
1990                 reply(150, "Opening %s mode data connection for '%s'%s.",
1991                      type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1992                 return (fdopen(pdata, mode));
1993 pdata_err:
1994                 reply(425, "Can't open data connection.");
1995                 (void) close(pdata);
1996                 pdata = -1;
1997                 return (NULL);
1998         }
1999         if (data >= 0) {
2000                 reply(125, "Using existing data connection for '%s'%s.",
2001                     name, sizebuf);
2002                 usedefault = 1;
2003                 return (fdopen(data, mode));
2004         }
2005         if (usedefault)
2006                 data_dest = his_addr;
2007         usedefault = 1;
2008         do {
2009                 file = getdatasock(mode);
2010                 if (file == NULL) {
2011                         char hostbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
2012
2013                         if (getnameinfo((struct sockaddr *)&data_source,
2014                                 data_source.su_len,
2015                                 hostbuf, sizeof(hostbuf) - 1,
2016                                 portbuf, sizeof(portbuf) - 1,
2017                                 NI_NUMERICHOST|NI_NUMERICSERV))
2018                                         *hostbuf = *portbuf = 0;
2019                         hostbuf[sizeof(hostbuf) - 1] = 0;
2020                         portbuf[sizeof(portbuf) - 1] = 0;
2021                         reply(425, "Can't create data socket (%s,%s): %s.",
2022                                 hostbuf, portbuf, strerror(errno));
2023                         return (NULL);
2024                 }
2025                 data = fileno(file);
2026                 conerrno = 0;
2027                 if (connect(data, (struct sockaddr *)&data_dest,
2028                     data_dest.su_len) == 0)
2029                         break;
2030                 conerrno = errno;
2031                 (void) fclose(file);
2032                 data = -1;
2033                 if (conerrno == EADDRINUSE) {
2034                         sleep(swaitint);
2035                         retry += swaitint;
2036                 } else {
2037                         break;
2038                 }
2039         } while (retry <= swaitmax);
2040         if (conerrno != 0) {
2041                 reply(425, "Can't build data connection: %s.",
2042                            strerror(conerrno));
2043                 return (NULL);
2044         }
2045         reply(150, "Opening %s mode data connection for '%s'%s.",
2046              type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
2047         return (file);
2048 }
2049
2050 /*
2051  * A helper macro to avoid code duplication
2052  * in send_data() and receive_data().
2053  *
2054  * XXX We have to block SIGURG during putc() because BSD stdio
2055  * is unable to restart interrupted write operations and hence
2056  * the entire buffer contents will be lost as soon as a write()
2057  * call indicates EINTR to stdio.
2058  */
2059 #define FTPD_PUTC(ch, file, label)                                      \
2060         do {                                                            \
2061                 int ret;                                                \
2062                                                                         \
2063                 do {                                                    \
2064                         START_UNSAFE;                                   \
2065                         ret = putc((ch), (file));                       \
2066                         END_UNSAFE;                                     \
2067                         CHECKOOB(return (-1))                           \
2068                         else if (ferror(file))                          \
2069                                 goto label;                             \
2070                         clearerr(file);                                 \
2071                 } while (ret == EOF);                                   \
2072         } while (0)
2073
2074 /*
2075  * Transfer the contents of "instr" to "outstr" peer using the appropriate
2076  * encapsulation of the data subject to Mode, Structure, and Type.
2077  *
2078  * NB: Form isn't handled.
2079  */
2080 static int
2081 send_data(FILE *instr, FILE *outstr, size_t blksize, off_t filesize, int isreg)
2082 {
2083         int c, cp, filefd, netfd;
2084         char *buf;
2085
2086         STARTXFER;
2087
2088         switch (type) {
2089
2090         case TYPE_A:
2091                 cp = EOF;
2092                 for (;;) {
2093                         c = getc(instr);
2094                         CHECKOOB(return (-1))
2095                         else if (c == EOF && ferror(instr))
2096                                 goto file_err;
2097                         if (c == EOF) {
2098                                 if (ferror(instr)) {    /* resume after OOB */
2099                                         clearerr(instr);
2100                                         continue;
2101                                 }
2102                                 if (feof(instr))        /* EOF */
2103                                         break;
2104                                 syslog(LOG_ERR, "Internal: impossible condition"
2105                                                 " on file after getc()");
2106                                 goto file_err;
2107                         }
2108                         if (c == '\n' && cp != '\r') {
2109                                 FTPD_PUTC('\r', outstr, data_err);
2110                                 byte_count++;
2111                         }
2112                         FTPD_PUTC(c, outstr, data_err);
2113                         byte_count++;
2114                         cp = c;
2115                 }
2116 #ifdef notyet   /* BSD stdio isn't ready for that */
2117                 while (fflush(outstr) == EOF) {
2118                         CHECKOOB(return (-1))
2119                         else
2120                                 goto data_err;
2121                         clearerr(outstr);
2122                 }
2123                 ENDXFER;
2124 #else
2125                 ENDXFER;
2126                 if (fflush(outstr) == EOF)
2127                         goto data_err;
2128 #endif
2129                 reply(226, "Transfer complete.");
2130                 return (0);
2131
2132         case TYPE_I:
2133         case TYPE_L:
2134                 /*
2135                  * isreg is only set if we are not doing restart and we
2136                  * are sending a regular file
2137                  */
2138                 netfd = fileno(outstr);
2139                 filefd = fileno(instr);
2140
2141                 if (isreg) {
2142                         char *msg = "Transfer complete.";
2143                         off_t cnt, offset;
2144                         int err;
2145
2146                         cnt = offset = 0;
2147
2148                         while (filesize > 0) {
2149                                 err = sendfile(filefd, netfd, offset, 0,
2150                                                NULL, &cnt, 0);
2151                                 /*
2152                                  * Calculate byte_count before OOB processing.
2153                                  * It can be used in myoob() later.
2154                                  */
2155                                 byte_count += cnt;
2156                                 offset += cnt;
2157                                 filesize -= cnt;
2158                                 CHECKOOB(return (-1))
2159                                 else if (err == -1) {
2160                                         if (errno != EINTR &&
2161                                             cnt == 0 && offset == 0)
2162                                                 goto oldway;
2163                                         goto data_err;
2164                                 }
2165                                 if (err == -1)  /* resume after OOB */
2166                                         continue;
2167                                 /*
2168                                  * We hit the EOF prematurely.
2169                                  * Perhaps the file was externally truncated.
2170                                  */
2171                                 if (cnt == 0) {
2172                                         msg = "Transfer finished due to "
2173                                               "premature end of file.";
2174                                         break;
2175                                 }
2176                         }
2177                         ENDXFER;
2178                         reply(226, "%s", msg);
2179                         return (0);
2180                 }
2181
2182 oldway:
2183                 if ((buf = malloc(blksize)) == NULL) {
2184                         ENDXFER;
2185                         reply(451, "Ran out of memory.");
2186                         return (-1);
2187                 }
2188
2189                 for (;;) {
2190                         int cnt, len;
2191                         char *bp;
2192
2193                         cnt = read(filefd, buf, blksize);
2194                         CHECKOOB(free(buf); return (-1))
2195                         else if (cnt < 0) {
2196                                 free(buf);
2197                                 goto file_err;
2198                         }
2199                         if (cnt < 0)    /* resume after OOB */
2200                                 continue;
2201                         if (cnt == 0)   /* EOF */
2202                                 break;
2203                         for (len = cnt, bp = buf; len > 0;) {
2204                                 cnt = write(netfd, bp, len);
2205                                 CHECKOOB(free(buf); return (-1))
2206                                 else if (cnt < 0) {
2207                                         free(buf);
2208                                         goto data_err;
2209                                 }
2210                                 if (cnt <= 0)
2211                                         continue;
2212                                 len -= cnt;
2213                                 bp += cnt;
2214                                 byte_count += cnt;
2215                         }
2216                 }
2217                 ENDXFER;
2218                 free(buf);
2219                 reply(226, "Transfer complete.");
2220                 return (0);
2221         default:
2222                 ENDXFER;
2223                 reply(550, "Unimplemented TYPE %d in send_data.", type);
2224                 return (-1);
2225         }
2226
2227 data_err:
2228         ENDXFER;
2229         perror_reply(426, "Data connection");
2230         return (-1);
2231
2232 file_err:
2233         ENDXFER;
2234         perror_reply(551, "Error on input file");
2235         return (-1);
2236 }
2237
2238 /*
2239  * Transfer data from peer to "outstr" using the appropriate encapulation of
2240  * the data subject to Mode, Structure, and Type.
2241  *
2242  * N.B.: Form isn't handled.
2243  */
2244 static int
2245 receive_data(FILE *instr, FILE *outstr)
2246 {
2247         int c, cp;
2248         int bare_lfs = 0;
2249
2250         STARTXFER;
2251
2252         switch (type) {
2253
2254         case TYPE_I:
2255         case TYPE_L:
2256                 for (;;) {
2257                         int cnt, len;
2258                         char *bp;
2259                         char buf[BUFSIZ];
2260
2261                         cnt = read(fileno(instr), buf, sizeof(buf));
2262                         CHECKOOB(return (-1))
2263                         else if (cnt < 0)
2264                                 goto data_err;
2265                         if (cnt < 0)    /* resume after OOB */
2266                                 continue;
2267                         if (cnt == 0)   /* EOF */
2268                                 break;
2269                         for (len = cnt, bp = buf; len > 0;) {
2270                                 cnt = write(fileno(outstr), bp, len);
2271                                 CHECKOOB(return (-1))
2272                                 else if (cnt < 0)
2273                                         goto file_err;
2274                                 if (cnt <= 0)
2275                                         continue;
2276                                 len -= cnt;
2277                                 bp += cnt;
2278                                 byte_count += cnt;
2279                         }
2280                 }
2281                 ENDXFER;
2282                 return (0);
2283
2284         case TYPE_E:
2285                 ENDXFER;
2286                 reply(553, "TYPE E not implemented.");
2287                 return (-1);
2288
2289         case TYPE_A:
2290                 cp = EOF;
2291                 for (;;) {
2292                         c = getc(instr);
2293                         CHECKOOB(return (-1))
2294                         else if (c == EOF && ferror(instr))
2295                                 goto data_err;
2296                         if (c == EOF && ferror(instr)) { /* resume after OOB */
2297                                 clearerr(instr);
2298                                 continue;
2299                         }
2300
2301                         if (cp == '\r') {
2302                                 if (c != '\n')
2303                                         FTPD_PUTC('\r', outstr, file_err);
2304                         } else
2305                                 if (c == '\n')
2306                                         bare_lfs++;
2307                         if (c == '\r') {
2308                                 byte_count++;
2309                                 cp = c;
2310                                 continue;
2311                         }
2312
2313                         /* Check for EOF here in order not to lose last \r. */
2314                         if (c == EOF) {
2315                                 if (feof(instr))        /* EOF */
2316                                         break;
2317                                 syslog(LOG_ERR, "Internal: impossible condition"
2318                                                 " on data stream after getc()");
2319                                 goto data_err;
2320                         }
2321
2322                         byte_count++;
2323                         FTPD_PUTC(c, outstr, file_err);
2324                         cp = c;
2325                 }
2326 #ifdef notyet   /* BSD stdio isn't ready for that */
2327                 while (fflush(outstr) == EOF) {
2328                         CHECKOOB(return (-1))
2329                         else
2330                                 goto file_err;
2331                         clearerr(outstr);
2332                 }
2333                 ENDXFER;
2334 #else
2335                 ENDXFER;
2336                 if (fflush(outstr) == EOF)
2337                         goto file_err;
2338 #endif
2339                 if (bare_lfs) {
2340                         lreply(226,
2341                 "WARNING! %d bare linefeeds received in ASCII mode.",
2342                             bare_lfs);
2343                 (void)printf("   File may not have transferred correctly.\r\n");
2344                 }
2345                 return (0);
2346         default:
2347                 ENDXFER;
2348                 reply(550, "Unimplemented TYPE %d in receive_data.", type);
2349                 return (-1);
2350         }
2351
2352 data_err:
2353         ENDXFER;
2354         perror_reply(426, "Data connection");
2355         return (-1);
2356
2357 file_err:
2358         ENDXFER;
2359         perror_reply(452, "Error writing to file");
2360         return (-1);
2361 }
2362
2363 void
2364 statfilecmd(char *filename)
2365 {
2366         FILE *fin;
2367         int atstart;
2368         int c, code;
2369         char line[LINE_MAX];
2370         struct stat st;
2371
2372         code = lstat(filename, &st) == 0 && S_ISDIR(st.st_mode) ? 212 : 213;
2373         (void)snprintf(line, sizeof(line), _PATH_LS " -lgA %s", filename);
2374         fin = ftpd_popen(line, "r");
2375         if (fin == NULL) {
2376                 perror_reply(551, filename);
2377                 return;
2378         }
2379         lreply(code, "Status of %s:", filename);
2380         atstart = 1;
2381         while ((c = getc(fin)) != EOF) {
2382                 if (c == '\n') {
2383                         if (ferror(stdout)){
2384                                 perror_reply(421, "Control connection");
2385                                 (void) ftpd_pclose(fin);
2386                                 dologout(1);
2387                                 /* NOTREACHED */
2388                         }
2389                         if (ferror(fin)) {
2390                                 perror_reply(551, filename);
2391                                 (void) ftpd_pclose(fin);
2392                                 return;
2393                         }
2394                         (void) putc('\r', stdout);
2395                 }
2396                 /*
2397                  * RFC 959 says neutral text should be prepended before
2398                  * a leading 3-digit number followed by whitespace, but
2399                  * many ftp clients can be confused by any leading digits,
2400                  * as a matter of fact.
2401                  */
2402                 if (atstart && isdigit(c))
2403                         (void) putc(' ', stdout);
2404                 (void) putc(c, stdout);
2405                 atstart = (c == '\n');
2406         }
2407         (void) ftpd_pclose(fin);
2408         reply(code, "End of status.");
2409 }
2410
2411 void
2412 statcmd(void)
2413 {
2414         union sockunion *su;
2415         u_char *a, *p;
2416         char hname[NI_MAXHOST];
2417         int ispassive;
2418
2419         if (hostinfo) {
2420                 lreply(211, "%s FTP server status:", hostname);
2421                 printf("     %s\r\n", version);
2422         } else
2423                 lreply(211, "FTP server status:");
2424         printf("     Connected to %s", remotehost);
2425         if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
2426                          hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {
2427                 hname[sizeof(hname) - 1] = 0;
2428                 if (strcmp(hname, remotehost) != 0)
2429                         printf(" (%s)", hname);
2430         }
2431         printf("\r\n");
2432         if (logged_in) {
2433                 if (guest)
2434                         printf("     Logged in anonymously\r\n");
2435                 else
2436                         printf("     Logged in as %s\r\n", pw->pw_name);
2437         } else if (askpasswd)
2438                 printf("     Waiting for password\r\n");
2439         else
2440                 printf("     Waiting for user name\r\n");
2441         printf("     TYPE: %s", typenames[type]);
2442         if (type == TYPE_A || type == TYPE_E)
2443                 printf(", FORM: %s", formnames[form]);
2444         if (type == TYPE_L)
2445 #if CHAR_BIT == 8
2446                 printf(" %d", CHAR_BIT);
2447 #else
2448                 printf(" %d", bytesize);        /* need definition! */
2449 #endif
2450         printf("; STRUcture: %s; transfer MODE: %s\r\n",
2451             strunames[stru], modenames[mode]);
2452         if (data != -1)
2453                 printf("     Data connection open\r\n");
2454         else if (pdata != -1) {
2455                 ispassive = 1;
2456                 su = &pasv_addr;
2457                 goto printaddr;
2458         } else if (usedefault == 0) {
2459                 ispassive = 0;
2460                 su = &data_dest;
2461 printaddr:
2462 #define UC(b) (((int) b) & 0xff)
2463                 if (epsvall) {
2464                         printf("     EPSV only mode (EPSV ALL)\r\n");
2465                         goto epsvonly;
2466                 }
2467
2468                 /* PORT/PASV */
2469                 if (su->su_family == AF_INET) {
2470                         a = (u_char *) &su->su_sin.sin_addr;
2471                         p = (u_char *) &su->su_sin.sin_port;
2472                         printf("     %s (%d,%d,%d,%d,%d,%d)\r\n",
2473                                 ispassive ? "PASV" : "PORT",
2474                                 UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2475                                 UC(p[0]), UC(p[1]));
2476                 }
2477
2478                 /* LPRT/LPSV */
2479             {
2480                 int alen, af, i;
2481
2482                 switch (su->su_family) {
2483                 case AF_INET:
2484                         a = (u_char *) &su->su_sin.sin_addr;
2485                         p = (u_char *) &su->su_sin.sin_port;
2486                         alen = sizeof(su->su_sin.sin_addr);
2487                         af = 4;
2488                         break;
2489                 case AF_INET6:
2490                         a = (u_char *) &su->su_sin6.sin6_addr;
2491                         p = (u_char *) &su->su_sin6.sin6_port;
2492                         alen = sizeof(su->su_sin6.sin6_addr);
2493                         af = 6;
2494                         break;
2495                 default:
2496                         af = 0;
2497                         break;
2498                 }
2499                 if (af) {
2500                         printf("     %s (%d,%d,", ispassive ? "LPSV" : "LPRT",
2501                                 af, alen);
2502                         for (i = 0; i < alen; i++)
2503                                 printf("%d,", UC(a[i]));
2504                         printf("%d,%d,%d)\r\n", 2, UC(p[0]), UC(p[1]));
2505                 }
2506             }
2507
2508 epsvonly:;
2509                 /* EPRT/EPSV */
2510             {
2511                 int af;
2512
2513                 switch (su->su_family) {
2514                 case AF_INET:
2515                         af = 1;
2516                         break;
2517                 case AF_INET6:
2518                         af = 2;
2519                         break;
2520                 default:
2521                         af = 0;
2522                         break;
2523                 }
2524                 if (af) {
2525                         union sockunion tmp;
2526
2527                         tmp = *su;
2528                         if (tmp.su_family == AF_INET6)
2529                                 tmp.su_sin6.sin6_scope_id = 0;
2530                         if (!getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
2531                                         hname, sizeof(hname) - 1, NULL, 0,
2532                                         NI_NUMERICHOST)) {
2533                                 hname[sizeof(hname) - 1] = 0;
2534                                 printf("     %s |%d|%s|%d|\r\n",
2535                                         ispassive ? "EPSV" : "EPRT",
2536                                         af, hname, htons(tmp.su_port));
2537                         }
2538                 }
2539             }
2540 #undef UC
2541         } else
2542                 printf("     No data connection\r\n");
2543         reply(211, "End of status.");
2544 }
2545
2546 void
2547 fatalerror(char *s)
2548 {
2549
2550         reply(451, "Error in server: %s", s);
2551         reply(221, "Closing connection due to server error.");
2552         dologout(0);
2553         /* NOTREACHED */
2554 }
2555
2556 void
2557 reply(int n, const char *fmt, ...)
2558 {
2559         va_list ap;
2560
2561         (void)printf("%d ", n);
2562         va_start(ap, fmt);
2563         (void)vprintf(fmt, ap);
2564         va_end(ap);
2565         (void)printf("\r\n");
2566         (void)fflush(stdout);
2567         if (ftpdebug) {
2568                 syslog(LOG_DEBUG, "<--- %d ", n);
2569                 va_start(ap, fmt);
2570                 vsyslog(LOG_DEBUG, fmt, ap);
2571                 va_end(ap);
2572         }
2573 }
2574
2575 void
2576 lreply(int n, const char *fmt, ...)
2577 {
2578         va_list ap;
2579
2580         (void)printf("%d- ", n);
2581         va_start(ap, fmt);
2582         (void)vprintf(fmt, ap);
2583         va_end(ap);
2584         (void)printf("\r\n");
2585         (void)fflush(stdout);
2586         if (ftpdebug) {
2587                 syslog(LOG_DEBUG, "<--- %d- ", n);
2588                 va_start(ap, fmt);
2589                 vsyslog(LOG_DEBUG, fmt, ap);
2590                 va_end(ap);
2591         }
2592 }
2593
2594 static void
2595 ack(char *s)
2596 {
2597
2598         reply(250, "%s command successful.", s);
2599 }
2600
2601 void
2602 nack(char *s)
2603 {
2604
2605         reply(502, "%s command not implemented.", s);
2606 }
2607
2608 /* ARGSUSED */
2609 void
2610 yyerror(char *s)
2611 {
2612         char *cp;
2613
2614         if ((cp = strchr(cbuf,'\n')))
2615                 *cp = '\0';
2616         reply(500, "%s: command not understood.", cbuf);
2617 }
2618
2619 void
2620 delete(char *name)
2621 {
2622         struct stat st;
2623
2624         LOGCMD("delete", name);
2625         if (lstat(name, &st) < 0) {
2626                 perror_reply(550, name);
2627                 return;
2628         }
2629         if (S_ISDIR(st.st_mode)) {
2630                 if (rmdir(name) < 0) {
2631                         perror_reply(550, name);
2632                         return;
2633                 }
2634                 goto done;
2635         }
2636         if (guest && noguestmod) {
2637                 reply(550, "Operation not permitted.");
2638                 return;
2639         }
2640         if (unlink(name) < 0) {
2641                 perror_reply(550, name);
2642                 return;
2643         }
2644 done:
2645         ack("DELE");
2646 }
2647
2648 void
2649 cwd(char *path)
2650 {
2651
2652         if (chdir(path) < 0)
2653                 perror_reply(550, path);
2654         else
2655                 ack("CWD");
2656 }
2657
2658 void
2659 makedir(char *name)
2660 {
2661         char *s;
2662
2663         LOGCMD("mkdir", name);
2664         if (guest && noguestmkd)
2665                 reply(550, "Operation not permitted.");
2666         else if (mkdir(name, 0777) < 0)
2667                 perror_reply(550, name);
2668         else {
2669                 if ((s = doublequote(name)) == NULL)
2670                         fatalerror("Ran out of memory.");
2671                 reply(257, "\"%s\" directory created.", s);
2672                 free(s);
2673         }
2674 }
2675
2676 void
2677 removedir(char *name)
2678 {
2679
2680         LOGCMD("rmdir", name);
2681         if (rmdir(name) < 0)
2682                 perror_reply(550, name);
2683         else
2684                 ack("RMD");
2685 }
2686
2687 void
2688 pwd(void)
2689 {
2690         char *s, path[MAXPATHLEN + 1];
2691
2692         if (getcwd(path, sizeof(path)) == NULL)
2693                 perror_reply(550, "Get current directory");
2694         else {
2695                 if ((s = doublequote(path)) == NULL)
2696                         fatalerror("Ran out of memory.");
2697                 reply(257, "\"%s\" is current directory.", s);
2698                 free(s);
2699         }
2700 }
2701
2702 char *
2703 renamefrom(char *name)
2704 {
2705         struct stat st;
2706
2707         if (guest && noguestmod) {
2708                 reply(550, "Operation not permitted.");
2709                 return (NULL);
2710         }
2711         if (lstat(name, &st) < 0) {
2712                 perror_reply(550, name);
2713                 return (NULL);
2714         }
2715         reply(350, "File exists, ready for destination name.");
2716         return (name);
2717 }
2718
2719 void
2720 renamecmd(char *from, char *to)
2721 {
2722         struct stat st;
2723
2724         LOGCMD2("rename", from, to);
2725
2726         if (guest && (stat(to, &st) == 0)) {
2727                 reply(550, "%s: permission denied.", to);
2728                 return;
2729         }
2730
2731         if (rename(from, to) < 0)
2732                 perror_reply(550, "rename");
2733         else
2734                 ack("RNTO");
2735 }
2736
2737 static void
2738 dolog(struct sockaddr *who)
2739 {
2740         char who_name[NI_MAXHOST];
2741
2742         realhostname_sa(remotehost, sizeof(remotehost) - 1, who, who->sa_len);
2743         remotehost[sizeof(remotehost) - 1] = 0;
2744         if (getnameinfo(who, who->sa_len,
2745                 who_name, sizeof(who_name) - 1, NULL, 0, NI_NUMERICHOST))
2746                         *who_name = 0;
2747         who_name[sizeof(who_name) - 1] = 0;
2748
2749 #ifdef SETPROCTITLE
2750 #ifdef VIRTUAL_HOSTING
2751         if (thishost != firsthost)
2752                 snprintf(proctitle, sizeof(proctitle), "%s: connected (to %s)",
2753                          remotehost, hostname);
2754         else
2755 #endif
2756                 snprintf(proctitle, sizeof(proctitle), "%s: connected",
2757                          remotehost);
2758         setproctitle("%s", proctitle);
2759 #endif /* SETPROCTITLE */
2760
2761         if (logging) {
2762 #ifdef VIRTUAL_HOSTING
2763                 if (thishost != firsthost)
2764                         syslog(LOG_INFO, "connection from %s (%s) to %s",
2765                                remotehost, who_name, hostname);
2766                 else
2767 #endif
2768                         syslog(LOG_INFO, "connection from %s (%s)",
2769                                remotehost, who_name);
2770         }
2771 }
2772
2773 /*
2774  * Record logout in wtmp file
2775  * and exit with supplied status.
2776  */
2777 void
2778 dologout(int status)
2779 {
2780
2781         if (logged_in && dowtmp) {
2782                 (void) seteuid(0);
2783 #ifdef          LOGIN_CAP
2784                 setusercontext(NULL, getpwuid(0), 0, LOGIN_SETALL & ~(LOGIN_SETLOGIN |
2785                        LOGIN_SETUSER | LOGIN_SETGROUP | LOGIN_SETPATH |
2786                        LOGIN_SETENV));
2787 #endif
2788                 ftpd_logwtmp(wtmpid, NULL, NULL);
2789         }
2790         /* beware of flushing buffers after a SIGPIPE */
2791         _exit(status);
2792 }
2793
2794 static void
2795 sigurg(int signo)
2796 {
2797
2798         recvurg = 1;
2799 }
2800
2801 static void
2802 maskurg(int flag)
2803 {
2804         int oerrno;
2805         sigset_t sset;
2806
2807         if (!transflag) {
2808                 syslog(LOG_ERR, "Internal: maskurg() while no transfer");
2809                 return;
2810         }
2811         oerrno = errno;
2812         sigemptyset(&sset);
2813         sigaddset(&sset, SIGURG);
2814         sigprocmask(flag ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
2815         errno = oerrno;
2816 }
2817
2818 static void
2819 flagxfer(int flag)
2820 {
2821
2822         if (flag) {
2823                 if (transflag)
2824                         syslog(LOG_ERR, "Internal: flagxfer(1): "
2825                                         "transfer already under way");
2826                 transflag = 1;
2827                 maskurg(0);
2828                 recvurg = 0;
2829         } else {
2830                 if (!transflag)
2831                         syslog(LOG_ERR, "Internal: flagxfer(0): "
2832                                         "no active transfer");
2833                 maskurg(1);
2834                 transflag = 0;
2835         }
2836 }
2837
2838 /*
2839  * Returns 0 if OK to resume or -1 if abort requested.
2840  */
2841 static int
2842 myoob(void)
2843 {
2844         char *cp;
2845         int ret;
2846
2847         if (!transflag) {
2848                 syslog(LOG_ERR, "Internal: myoob() while no transfer");
2849                 return (0);
2850         }
2851         cp = tmpline;
2852         ret = get_line(cp, 7, stdin);
2853         if (ret == -1) {
2854                 reply(221, "You could at least say goodbye.");
2855                 dologout(0);
2856         } else if (ret == -2) {
2857                 /* Ignore truncated command. */
2858                 return (0);
2859         }
2860         upper(cp);
2861         if (strcmp(cp, "ABOR\r\n") == 0) {
2862                 tmpline[0] = '\0';
2863                 reply(426, "Transfer aborted. Data connection closed.");
2864                 reply(226, "Abort successful.");
2865                 return (-1);
2866         }
2867         if (strcmp(cp, "STAT\r\n") == 0) {
2868                 tmpline[0] = '\0';
2869                 if (file_size != -1)
2870                         reply(213, "Status: %jd of %jd bytes transferred.",
2871                                    (intmax_t)byte_count, (intmax_t)file_size);
2872                 else
2873                         reply(213, "Status: %jd bytes transferred.",
2874                                    (intmax_t)byte_count);
2875         }
2876         return (0);
2877 }
2878
2879 /*
2880  * Note: a response of 425 is not mentioned as a possible response to
2881  *      the PASV command in RFC959. However, it has been blessed as
2882  *      a legitimate response by Jon Postel in a telephone conversation
2883  *      with Rick Adams on 25 Jan 89.
2884  */
2885 void
2886 passive(void)
2887 {
2888         socklen_t len;
2889         int on;
2890         char *p, *a;
2891
2892         if (pdata >= 0)         /* close old port if one set */
2893                 close(pdata);
2894
2895         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2896         if (pdata < 0) {
2897                 perror_reply(425, "Can't open passive connection");
2898                 return;
2899         }
2900         on = 1;
2901         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2902                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2903
2904         (void) seteuid(0);
2905
2906 #ifdef IP_PORTRANGE
2907         if (ctrl_addr.su_family == AF_INET) {
2908             on = restricted_data_ports ? IP_PORTRANGE_HIGH
2909                                        : IP_PORTRANGE_DEFAULT;
2910
2911             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2912                             &on, sizeof(on)) < 0)
2913                     goto pasv_error;
2914         }
2915 #endif
2916 #ifdef IPV6_PORTRANGE
2917         if (ctrl_addr.su_family == AF_INET6) {
2918             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2919                                        : IPV6_PORTRANGE_DEFAULT;
2920
2921             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2922                             &on, sizeof(on)) < 0)
2923                     goto pasv_error;
2924         }
2925 #endif
2926
2927         pasv_addr = ctrl_addr;
2928         pasv_addr.su_port = 0;
2929         if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2930                 goto pasv_error;
2931
2932         (void) seteuid(pw->pw_uid);
2933
2934         len = sizeof(pasv_addr);
2935         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2936                 goto pasv_error;
2937         if (listen(pdata, 1) < 0)
2938                 goto pasv_error;
2939         if (pasv_addr.su_family == AF_INET)
2940                 a = (char *) &pasv_addr.su_sin.sin_addr;
2941         else if (pasv_addr.su_family == AF_INET6 &&
2942                  IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr))
2943                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2944         else
2945                 goto pasv_error;
2946                 
2947         p = (char *) &pasv_addr.su_port;
2948
2949 #define UC(b) (((int) b) & 0xff)
2950
2951         reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
2952                 UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
2953         return;
2954
2955 pasv_error:
2956         (void) seteuid(pw->pw_uid);
2957         (void) close(pdata);
2958         pdata = -1;
2959         perror_reply(425, "Can't open passive connection");
2960         return;
2961 }
2962
2963 /*
2964  * Long Passive defined in RFC 1639.
2965  *     228 Entering Long Passive Mode
2966  *         (af, hal, h1, h2, h3,..., pal, p1, p2...)
2967  */
2968
2969 void
2970 long_passive(char *cmd, int pf)
2971 {
2972         socklen_t len;
2973         int on;
2974         char *p, *a;
2975
2976         if (pdata >= 0)         /* close old port if one set */
2977                 close(pdata);
2978
2979         if (pf != PF_UNSPEC) {
2980                 if (ctrl_addr.su_family != pf) {
2981                         switch (ctrl_addr.su_family) {
2982                         case AF_INET:
2983                                 pf = 1;
2984                                 break;
2985                         case AF_INET6:
2986                                 pf = 2;
2987                                 break;
2988                         default:
2989                                 pf = 0;
2990                                 break;
2991                         }
2992                         /*
2993                          * XXX
2994                          * only EPRT/EPSV ready clients will understand this
2995                          */
2996                         if (strcmp(cmd, "EPSV") == 0 && pf) {
2997                                 reply(522, "Network protocol mismatch, "
2998                                         "use (%d)", pf);
2999                         } else
3000                                 reply(501, "Network protocol mismatch."); /*XXX*/
3001
3002                         return;
3003                 }
3004         }
3005                 
3006         pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
3007         if (pdata < 0) {
3008                 perror_reply(425, "Can't open passive connection");
3009                 return;
3010         }
3011         on = 1;
3012         if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
3013                 syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
3014
3015         (void) seteuid(0);
3016
3017         pasv_addr = ctrl_addr;
3018         pasv_addr.su_port = 0;
3019         len = pasv_addr.su_len;
3020
3021 #ifdef IP_PORTRANGE
3022         if (ctrl_addr.su_family == AF_INET) {
3023             on = restricted_data_ports ? IP_PORTRANGE_HIGH
3024                                        : IP_PORTRANGE_DEFAULT;
3025
3026             if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
3027                             &on, sizeof(on)) < 0)
3028                     goto pasv_error;
3029         }
3030 #endif
3031 #ifdef IPV6_PORTRANGE
3032         if (ctrl_addr.su_family == AF_INET6) {
3033             on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
3034                                        : IPV6_PORTRANGE_DEFAULT;
3035
3036             if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
3037                             &on, sizeof(on)) < 0)
3038                     goto pasv_error;
3039         }
3040 #endif
3041
3042         if (bind(pdata, (struct sockaddr *)&pasv_addr, len) < 0)
3043                 goto pasv_error;
3044
3045         (void) seteuid(pw->pw_uid);
3046
3047         if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
3048                 goto pasv_error;
3049         if (listen(pdata, 1) < 0)
3050                 goto pasv_error;
3051
3052 #define UC(b) (((int) b) & 0xff)
3053
3054         if (strcmp(cmd, "LPSV") == 0) {
3055                 p = (char *)&pasv_addr.su_port;
3056                 switch (pasv_addr.su_family) {
3057                 case AF_INET:
3058                         a = (char *) &pasv_addr.su_sin.sin_addr;
3059                 v4_reply:
3060                         reply(228,
3061 "Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3062                               4, 4, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3063                               2, UC(p[0]), UC(p[1]));
3064                         return;
3065                 case AF_INET6:
3066                         if (IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr)) {
3067                                 a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
3068                                 goto v4_reply;
3069                         }
3070                         a = (char *) &pasv_addr.su_sin6.sin6_addr;
3071                         reply(228,
3072 "Entering Long Passive Mode "
3073 "(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)",
3074                               6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
3075                               UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
3076                               UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
3077                               UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
3078                               2, UC(p[0]), UC(p[1]));
3079                         return;
3080                 }
3081         } else if (strcmp(cmd, "EPSV") == 0) {
3082                 switch (pasv_addr.su_family) {
3083                 case AF_INET:
3084                 case AF_INET6:
3085                         reply(229, "Entering Extended Passive Mode (|||%d|)",
3086                                 ntohs(pasv_addr.su_port));
3087                         return;
3088                 }
3089         } else {
3090                 /* more proper error code? */
3091         }
3092
3093 pasv_error:
3094         (void) seteuid(pw->pw_uid);
3095         (void) close(pdata);
3096         pdata = -1;
3097         perror_reply(425, "Can't open passive connection");
3098         return;
3099 }
3100
3101 /*
3102  * Generate unique name for file with basename "local"
3103  * and open the file in order to avoid possible races.
3104  * Try "local" first, then "local.1", "local.2" etc, up to "local.99".
3105  * Return descriptor to the file, set "name" to its name.
3106  *
3107  * Generates failure reply on error.
3108  */
3109 static int
3110 guniquefd(char *local, char **name)
3111 {
3112         static char new[MAXPATHLEN];
3113         struct stat st;
3114         char *cp;
3115         int count;
3116         int fd;
3117
3118         cp = strrchr(local, '/');
3119         if (cp)
3120                 *cp = '\0';
3121         if (stat(cp ? local : ".", &st) < 0) {
3122                 perror_reply(553, cp ? local : ".");
3123                 return (-1);
3124         }
3125         if (cp) {
3126                 /*
3127                  * Let not overwrite dirname with counter suffix.
3128                  * -4 is for /nn\0
3129                  * In this extreme case dot won't be put in front of suffix.
3130                  */
3131                 if (strlen(local) > sizeof(new) - 4) {
3132                         reply(553, "Pathname too long.");
3133                         return (-1);
3134                 }
3135                 *cp = '/';
3136         }
3137         /* -4 is for the .nn<null> we put on the end below */
3138         (void) snprintf(new, sizeof(new) - 4, "%s", local);
3139         cp = new + strlen(new);
3140         /* 
3141          * Don't generate dotfile unless requested explicitly.
3142          * This covers the case when basename gets truncated off
3143          * by buffer size.
3144          */
3145         if (cp > new && cp[-1] != '/')
3146                 *cp++ = '.';
3147         for (count = 0; count < 100; count++) {
3148                 /* At count 0 try unmodified name */
3149                 if (count)
3150                         (void)sprintf(cp, "%d", count);
3151                 if ((fd = open(count ? new : local,
3152                     O_RDWR | O_CREAT | O_EXCL, 0666)) >= 0) {
3153                         *name = count ? new : local;
3154                         return (fd);
3155                 }
3156                 if (errno != EEXIST) {
3157                         perror_reply(553, count ? new : local);
3158                         return (-1);
3159                 }
3160         }
3161         reply(452, "Unique file name cannot be created.");
3162         return (-1);
3163 }
3164
3165 /*
3166  * Format and send reply containing system error number.
3167  */
3168 void
3169 perror_reply(int code, char *string)
3170 {
3171
3172         reply(code, "%s: %s.", string, strerror(errno));
3173 }
3174
3175 static char *onefile[] = {
3176         "",
3177         0
3178 };
3179
3180 void
3181 send_file_list(char *whichf)
3182 {
3183         struct stat st;
3184         DIR *dirp = NULL;
3185         struct dirent *dir;
3186         FILE *dout = NULL;
3187         char **dirlist, *dirname;
3188         int simple = 0;
3189         int freeglob = 0;
3190         glob_t gl;
3191
3192         if (strpbrk(whichf, "~{[*?") != NULL) {
3193                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
3194
3195                 memset(&gl, 0, sizeof(gl));
3196                 gl.gl_matchc = MAXGLOBARGS;
3197                 flags |= GLOB_LIMIT;
3198                 freeglob = 1;
3199                 if (glob(whichf, flags, 0, &gl)) {
3200                         reply(550, "No matching files found.");
3201                         goto out;
3202                 } else if (gl.gl_pathc == 0) {
3203                         errno = ENOENT;
3204                         perror_reply(550, whichf);
3205                         goto out;
3206                 }
3207                 dirlist = gl.gl_pathv;
3208         } else {
3209                 onefile[0] = whichf;
3210                 dirlist = onefile;
3211                 simple = 1;
3212         }
3213
3214         while ((dirname = *dirlist++)) {
3215                 if (stat(dirname, &st) < 0) {
3216                         /*
3217                          * If user typed "ls -l", etc, and the client
3218                          * used NLST, do what the user meant.
3219                          */
3220                         if (dirname[0] == '-' && *dirlist == NULL &&
3221                             dout == NULL)
3222                                 retrieve(_PATH_LS " %s", dirname);
3223                         else
3224                                 perror_reply(550, whichf);
3225                         goto out;
3226                 }
3227
3228                 if (S_ISREG(st.st_mode)) {
3229                         if (dout == NULL) {
3230                                 dout = dataconn("file list", -1, "w");
3231                                 if (dout == NULL)
3232                                         goto out;
3233                                 STARTXFER;
3234                         }
3235                         START_UNSAFE;
3236                         fprintf(dout, "%s%s\n", dirname,
3237                                 type == TYPE_A ? "\r" : "");
3238                         END_UNSAFE;
3239                         if (ferror(dout))
3240                                 goto data_err;
3241                         byte_count += strlen(dirname) +
3242                                       (type == TYPE_A ? 2 : 1);
3243                         CHECKOOB(goto abrt);
3244                         continue;
3245                 } else if (!S_ISDIR(st.st_mode))
3246                         continue;
3247
3248                 if ((dirp = opendir(dirname)) == NULL)
3249                         continue;
3250
3251                 while ((dir = readdir(dirp)) != NULL) {
3252                         char nbuf[MAXPATHLEN];
3253
3254                         CHECKOOB(goto abrt);
3255
3256                         if (dir->d_name[0] == '.' && dir->d_namlen == 1)
3257                                 continue;
3258                         if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
3259                             dir->d_namlen == 2)
3260                                 continue;
3261
3262                         snprintf(nbuf, sizeof(nbuf),
3263                                 "%s/%s", dirname, dir->d_name);
3264
3265                         /*
3266                          * We have to do a stat to insure it's
3267                          * not a directory or special file.
3268                          */
3269                         if (simple || (stat(nbuf, &st) == 0 &&
3270                             S_ISREG(st.st_mode))) {
3271                                 if (dout == NULL) {
3272                                         dout = dataconn("file list", -1, "w");
3273                                         if (dout == NULL)
3274                                                 goto out;
3275                                         STARTXFER;
3276                                 }
3277                                 START_UNSAFE;
3278                                 if (nbuf[0] == '.' && nbuf[1] == '/')
3279                                         fprintf(dout, "%s%s\n", &nbuf[2],
3280                                                 type == TYPE_A ? "\r" : "");
3281                                 else
3282                                         fprintf(dout, "%s%s\n", nbuf,
3283                                                 type == TYPE_A ? "\r" : "");
3284                                 END_UNSAFE;
3285                                 if (ferror(dout))
3286                                         goto data_err;
3287                                 byte_count += strlen(nbuf) +
3288                                               (type == TYPE_A ? 2 : 1);
3289                                 CHECKOOB(goto abrt);
3290                         }
3291                 }
3292                 (void) closedir(dirp);
3293                 dirp = NULL;
3294         }
3295
3296         if (dout == NULL)
3297                 reply(550, "No files found.");
3298         else if (ferror(dout))
3299 data_err:       perror_reply(550, "Data connection");
3300         else
3301                 reply(226, "Transfer complete.");
3302 out:
3303         if (dout) {
3304                 ENDXFER;
3305 abrt:
3306                 (void) fclose(dout);
3307                 data = -1;
3308                 pdata = -1;
3309         }
3310         if (dirp)
3311                 (void) closedir(dirp);
3312         if (freeglob) {
3313                 freeglob = 0;
3314                 globfree(&gl);
3315         }
3316 }
3317
3318 void
3319 reapchild(int signo)
3320 {
3321         while (waitpid(-1, NULL, WNOHANG) > 0);
3322 }
3323
3324 #ifdef OLD_SETPROCTITLE
3325 /*
3326  * Clobber argv so ps will show what we're doing.  (Stolen from sendmail.)
3327  * Warning, since this is usually started from inetd.conf, it often doesn't
3328  * have much of an environment or arglist to overwrite.
3329  */
3330 void
3331 setproctitle(const char *fmt, ...)
3332 {
3333         int i;
3334         va_list ap;
3335         char *p, *bp, ch;
3336         char buf[LINE_MAX];
3337
3338         va_start(ap, fmt);
3339         (void)vsnprintf(buf, sizeof(buf), fmt, ap);
3340
3341         /* make ps print our process name */
3342         p = Argv[0];
3343         *p++ = '-';
3344
3345         i = strlen(buf);
3346         if (i > LastArgv - p - 2) {
3347                 i = LastArgv - p - 2;
3348                 buf[i] = '\0';
3349         }
3350         bp = buf;
3351         while (ch = *bp++)
3352                 if (ch != '\n' && ch != '\r')
3353                         *p++ = ch;
3354         while (p < LastArgv)
3355                 *p++ = ' ';
3356 }
3357 #endif /* OLD_SETPROCTITLE */
3358
3359 static void
3360 appendf(char **strp, char *fmt, ...)
3361 {
3362         va_list ap;
3363         char *ostr, *p;
3364
3365         va_start(ap, fmt);
3366         vasprintf(&p, fmt, ap);
3367         va_end(ap);
3368         if (p == NULL)
3369                 fatalerror("Ran out of memory.");
3370         if (*strp == NULL)
3371                 *strp = p;
3372         else {
3373                 ostr = *strp;
3374                 asprintf(strp, "%s%s", ostr, p);
3375                 if (*strp == NULL)
3376                         fatalerror("Ran out of memory.");
3377                 free(ostr);
3378         }
3379 }
3380
3381 static void
3382 logcmd(char *cmd, char *file1, char *file2, off_t cnt)
3383 {
3384         char *msg = NULL;
3385         char wd[MAXPATHLEN + 1];
3386
3387         if (logging <= 1)
3388                 return;
3389
3390         if (getcwd(wd, sizeof(wd) - 1) == NULL)
3391                 strcpy(wd, strerror(errno));
3392
3393         appendf(&msg, "%s", cmd);
3394         if (file1)
3395                 appendf(&msg, " %s", file1);
3396         if (file2)
3397                 appendf(&msg, " %s", file2);
3398         if (cnt >= 0)
3399                 appendf(&msg, " = %jd bytes", (intmax_t)cnt);
3400         appendf(&msg, " (wd: %s", wd);
3401         if (guest || dochroot)
3402                 appendf(&msg, "; chrooted");
3403         appendf(&msg, ")");
3404         syslog(LOG_INFO, "%s", msg);
3405         free(msg);
3406 }
3407
3408 static void
3409 logxfer(char *name, off_t size, time_t start)
3410 {
3411         char buf[MAXPATHLEN + 1024];
3412         char path[MAXPATHLEN + 1];
3413         time_t now;
3414
3415         if (statfd >= 0) {
3416                 time(&now);
3417                 if (realpath(name, path) == NULL) {
3418                         syslog(LOG_NOTICE, "realpath failed on %s: %m", path);
3419                         return;
3420                 }
3421                 snprintf(buf, sizeof(buf), "%.20s!%s!%s!%s!%jd!%ld\n",
3422                         ctime(&now)+4, ident, remotehost,
3423                         path, (intmax_t)size,
3424                         (long)(now - start + (now == start)));
3425                 write(statfd, buf, strlen(buf));
3426         }
3427 }
3428
3429 static char *
3430 doublequote(char *s)
3431 {
3432         int n;
3433         char *p, *s2;
3434
3435         for (p = s, n = 0; *p; p++)
3436                 if (*p == '"')
3437                         n++;
3438
3439         if ((s2 = malloc(p - s + n + 1)) == NULL)
3440                 return (NULL);
3441
3442         for (p = s2; *s; s++, p++) {
3443                 if ((*p = *s) == '"')
3444                         *(++p) = '"';
3445         }
3446         *p = '\0';
3447
3448         return (s2);
3449 }
3450
3451 /* setup server socket for specified address family */
3452 /* if af is PF_UNSPEC more than one socket may be returned */
3453 /* the returned list is dynamically allocated, so caller needs to free it */
3454 static int *
3455 socksetup(int af, char *bindname, const char *bindport)
3456 {
3457         struct addrinfo hints, *res, *r;
3458         int error, maxs, *s, *socks;
3459         const int on = 1;
3460
3461         memset(&hints, 0, sizeof(hints));
3462         hints.ai_flags = AI_PASSIVE;
3463         hints.ai_family = af;
3464         hints.ai_socktype = SOCK_STREAM;
3465         error = getaddrinfo(bindname, bindport, &hints, &res);
3466         if (error) {
3467                 syslog(LOG_ERR, "%s", gai_strerror(error));
3468                 if (error == EAI_SYSTEM)
3469                         syslog(LOG_ERR, "%s", strerror(errno));
3470                 return NULL;
3471         }
3472
3473         /* Count max number of sockets we may open */
3474         for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
3475                 ;
3476         socks = malloc((maxs + 1) * sizeof(int));
3477         if (!socks) {
3478                 freeaddrinfo(res);
3479                 syslog(LOG_ERR, "couldn't allocate memory for sockets");
3480                 return NULL;
3481         }
3482
3483         *socks = 0;   /* num of sockets counter at start of array */
3484         s = socks + 1;
3485         for (r = res; r; r = r->ai_next) {
3486                 *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
3487                 if (*s < 0) {
3488                         syslog(LOG_DEBUG, "control socket: %m");
3489                         continue;
3490                 }
3491                 if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR,
3492                     &on, sizeof(on)) < 0)
3493                         syslog(LOG_WARNING,
3494                             "control setsockopt (SO_REUSEADDR): %m");
3495                 if (r->ai_family == AF_INET6) {
3496                         if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY,
3497                             &on, sizeof(on)) < 0)
3498                                 syslog(LOG_WARNING,
3499                                     "control setsockopt (IPV6_V6ONLY): %m");
3500                 }
3501                 if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
3502                         syslog(LOG_DEBUG, "control bind: %m");
3503                         close(*s);
3504                         continue;
3505                 }
3506                 (*socks)++;
3507                 s++;
3508         }
3509
3510         if (res)
3511                 freeaddrinfo(res);
3512
3513         if (*socks == 0) {
3514                 syslog(LOG_ERR, "control socket: Couldn't bind to any socket");
3515                 free(socks);
3516                 return NULL;
3517         }
3518         return(socks);
3519 }