Annotation of src/crypto/external/bsd/openssh/dist/session.c, Revision 1.8.4.1
1.8.4.1 ! snj 1: /* $NetBSD: session.c,v 1.8 2011/09/16 15:36:18 joerg Exp $ */
! 2: /* $OpenBSD: session.c,v 1.286 2016/11/30 03:00:05 djm Exp $ */
! 3:
1.1 christos 4: /*
5: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6: * All rights reserved
7: *
8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: *
14: * SSH2 support by Markus Friedl.
15: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
16: *
17: * Redistribution and use in source and binary forms, with or without
18: * modification, are permitted provided that the following conditions
19: * are met:
20: * 1. Redistributions of source code must retain the above copyright
21: * notice, this list of conditions and the following disclaimer.
22: * 2. Redistributions in binary form must reproduce the above copyright
23: * notice, this list of conditions and the following disclaimer in the
24: * documentation and/or other materials provided with the distribution.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36: */
37:
1.2 christos 38: #include "includes.h"
1.8.4.1 ! snj 39: __RCSID("$NetBSD: session.c,v 1.8 2011/09/16 15:36:18 joerg Exp $");
1.1 christos 40: #include <sys/types.h>
41: #include <sys/wait.h>
42: #include <sys/un.h>
43: #include <sys/stat.h>
44: #include <sys/socket.h>
45: #include <sys/queue.h>
46:
1.8.4.1 ! snj 47: #include <ctype.h>
1.1 christos 48: #include <errno.h>
1.4 adam 49: #include <fcntl.h>
1.1 christos 50: #include <grp.h>
51: #include <login_cap.h>
1.8.4.1 ! snj 52: #include <netdb.h>
1.1 christos 53: #include <paths.h>
54: #include <pwd.h>
55: #include <signal.h>
56: #include <stdio.h>
57: #include <stdlib.h>
58: #include <string.h>
59: #include <unistd.h>
1.8.4.1 ! snj 60: #include <limits.h>
1.1 christos 61:
62: #include "xmalloc.h"
63: #include "ssh.h"
64: #include "ssh2.h"
65: #include "sshpty.h"
66: #include "packet.h"
67: #include "buffer.h"
68: #include "match.h"
69: #include "uidswap.h"
70: #include "compat.h"
71: #include "channels.h"
72: #include "key.h"
73: #include "cipher.h"
74: #include "kex.h"
75: #include "hostfile.h"
76: #include "auth.h"
77: #include "auth-options.h"
1.8.4.1 ! snj 78: #include "authfd.h"
1.1 christos 79: #include "pathnames.h"
80: #include "log.h"
1.8.4.1 ! snj 81: #include "misc.h"
1.1 christos 82: #include "servconf.h"
83: #include "sshlogin.h"
84: #include "serverloop.h"
85: #include "canohost.h"
86: #include "session.h"
87: #ifdef GSSAPI
88: #include "ssh-gss.h"
89: #endif
90: #include "monitor_wrap.h"
91: #include "sftp.h"
92:
93: #ifdef KRB5
1.6 elric 94: #include <krb5/kafs.h>
1.1 christos 95: #endif
96:
97: #define IS_INTERNAL_SFTP(c) \
98: (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
99: (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
100: c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
101: c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
102:
103: /* func */
104:
105: Session *session_new(void);
1.4 adam 106: void session_set_fds(Session *, int, int, int, int, int);
1.1 christos 107: void session_pty_cleanup(Session *);
108: void session_proctitle(Session *);
109: int session_setup_x11fwd(Session *);
110: int do_exec_pty(Session *, const char *);
111: int do_exec_no_pty(Session *, const char *);
112: int do_exec(Session *, const char *);
113: void do_login(Session *, const char *);
1.8 joerg 114: __dead void do_child(Session *, const char *);
1.1 christos 115: void do_motd(void);
116: int check_quietlogin(Session *, const char *);
117:
118: static void do_authenticated2(Authctxt *);
119:
120: static int session_pty_req(Session *);
121:
122: /* import */
123: extern ServerOptions options;
124: extern char *__progname;
125: extern int log_stderr;
126: extern int debug_flag;
127: extern u_int utmp_len;
128: extern int startup_pipe;
129: extern void destroy_sensitive_data(void);
130: extern Buffer loginmsg;
131:
132: /* original command from peer. */
133: const char *original_command = NULL;
134:
135: /* data */
136: static int sessions_first_unused = -1;
137: static int sessions_nalloc = 0;
138: static Session *sessions = NULL;
139:
1.4 adam 140: #define SUBSYSTEM_NONE 0
141: #define SUBSYSTEM_EXT 1
142: #define SUBSYSTEM_INT_SFTP 2
143: #define SUBSYSTEM_INT_SFTP_ERROR 3
1.1 christos 144:
1.2 christos 145: #ifdef HAVE_LOGIN_CAP
1.1 christos 146: login_cap_t *lc;
1.2 christos 147: #endif
1.1 christos 148:
149: static int is_child = 0;
1.8.4.1 ! snj 150: static int in_chroot = 0;
1.1 christos 151:
152: /* Name and directory of socket for authentication agent forwarding. */
153: static char *auth_sock_name = NULL;
154: static char *auth_sock_dir = NULL;
155:
156: /* removes the agent forwarding socket */
157:
158: static void
159: auth_sock_cleanup_proc(struct passwd *pw)
160: {
161: if (auth_sock_name != NULL) {
162: temporarily_use_uid(pw);
163: unlink(auth_sock_name);
164: rmdir(auth_sock_dir);
165: auth_sock_name = NULL;
166: restore_uid();
167: }
168: }
169:
170: static int
171: auth_input_request_forwarding(struct passwd * pw)
172: {
173: Channel *nc;
174: int sock = -1;
175:
176: if (auth_sock_name != NULL) {
177: error("authentication forwarding requested twice.");
178: return 0;
179: }
180:
181: /* Temporarily drop privileged uid for mkdir/bind. */
182: temporarily_use_uid(pw);
183:
184: /* Allocate a buffer for the socket name, and format the name. */
185: auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
186:
187: /* Create private directory for socket */
188: if (mkdtemp(auth_sock_dir) == NULL) {
189: packet_send_debug("Agent forwarding disabled: "
190: "mkdtemp() failed: %.100s", strerror(errno));
191: restore_uid();
1.8.4.1 ! snj 192: free(auth_sock_dir);
1.1 christos 193: auth_sock_dir = NULL;
194: goto authsock_err;
195: }
196:
197: xasprintf(&auth_sock_name, "%s/agent.%ld",
198: auth_sock_dir, (long) getpid());
199:
1.8.4.1 ! snj 200: /* Start a Unix listener on auth_sock_name. */
! 201: sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
1.1 christos 202:
203: /* Restore the privileged uid. */
204: restore_uid();
205:
1.8.4.1 ! snj 206: /* Check for socket/bind/listen failure. */
! 207: if (sock < 0)
1.1 christos 208: goto authsock_err;
209:
210: /* Allocate a channel for the authentication agent socket. */
1.2 christos 211: /* this shouldn't matter if its hpn or not - cjr */
1.1 christos 212: nc = channel_new("auth socket",
213: SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
214: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
215: 0, "auth socket", 1);
216: nc->path = xstrdup(auth_sock_name);
217: return 1;
218:
219: authsock_err:
1.8.4.1 ! snj 220: free(auth_sock_name);
1.1 christos 221: if (auth_sock_dir != NULL) {
222: rmdir(auth_sock_dir);
1.8.4.1 ! snj 223: free(auth_sock_dir);
1.1 christos 224: }
225: if (sock != -1)
226: close(sock);
227: auth_sock_name = NULL;
228: auth_sock_dir = NULL;
229: return 0;
230: }
231:
232: static void
233: display_loginmsg(void)
234: {
235: if (buffer_len(&loginmsg) > 0) {
236: buffer_append(&loginmsg, "\0", 1);
237: printf("%s", (char *)buffer_ptr(&loginmsg));
238: buffer_clear(&loginmsg);
239: }
240: }
241:
242: void
243: do_authenticated(Authctxt *authctxt)
244: {
245: setproctitle("%s", authctxt->pw->pw_name);
246:
247: /* setup the channel layer */
1.8.4.1 ! snj 248: /* XXX - streamlocal? */
! 249: if (no_port_forwarding_flag || options.disable_forwarding ||
! 250: (options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
! 251: channel_disable_adm_local_opens();
! 252: else
1.1 christos 253: channel_permit_all_opens();
254:
1.4 adam 255: auth_debug_send();
256:
1.8.4.1 ! snj 257: do_authenticated2(authctxt);
1.1 christos 258: do_cleanup(authctxt);
259: }
260:
1.8.4.1 ! snj 261: /* Check untrusted xauth strings for metacharacters */
! 262: static int
! 263: xauth_valid_string(const char *s)
1.1 christos 264: {
1.8.4.1 ! snj 265: size_t i;
1.1 christos 266:
1.8.4.1 ! snj 267: for (i = 0; s[i] != '\0'; i++) {
! 268: if (!isalnum((u_char)s[i]) &&
! 269: s[i] != '.' && s[i] != ':' && s[i] != '/' &&
! 270: s[i] != '-' && s[i] != '_')
! 271: return 0;
1.1 christos 272: }
1.8.4.1 ! snj 273: return 1;
1.1 christos 274: }
275:
1.8.4.1 ! snj 276: #define USE_PIPES 1
1.1 christos 277: /*
278: * This is called to fork and execute a command when we have no tty. This
279: * will call do_child from the child, and server_loop from the parent after
280: * setting up file descriptors and such.
281: */
282: int
283: do_exec_no_pty(Session *s, const char *command)
284: {
285: pid_t pid;
286: #ifdef USE_PIPES
287: int pin[2], pout[2], perr[2];
288:
1.4 adam 289: if (s == NULL)
290: fatal("do_exec_no_pty: no session");
291:
1.1 christos 292: /* Allocate pipes for communicating with the program. */
293: if (pipe(pin) < 0) {
294: error("%s: pipe in: %.100s", __func__, strerror(errno));
295: return -1;
296: }
297: if (pipe(pout) < 0) {
298: error("%s: pipe out: %.100s", __func__, strerror(errno));
299: close(pin[0]);
300: close(pin[1]);
301: return -1;
302: }
303: if (pipe(perr) < 0) {
1.4 adam 304: error("%s: pipe err: %.100s", __func__,
305: strerror(errno));
1.1 christos 306: close(pin[0]);
307: close(pin[1]);
308: close(pout[0]);
309: close(pout[1]);
310: return -1;
311: }
312: #else
313: int inout[2], err[2];
314:
1.4 adam 315: if (s == NULL)
316: fatal("do_exec_no_pty: no session");
317:
1.1 christos 318: /* Uses socket pairs to communicate with the program. */
319: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) {
320: error("%s: socketpair #1: %.100s", __func__, strerror(errno));
321: return -1;
322: }
323: if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) {
1.4 adam 324: error("%s: socketpair #2: %.100s", __func__,
325: strerror(errno));
1.1 christos 326: close(inout[0]);
327: close(inout[1]);
328: return -1;
329: }
330: #endif
331:
332: session_proctitle(s);
333:
1.2 christos 334: #ifdef notdef
335: #if defined(USE_PAM)
336: if (options.use_pam && !use_privsep)
337: do_pam_setcred(1);
338: #endif /* USE_PAM */
339: #endif
340:
1.1 christos 341: /* Fork the child. */
342: switch ((pid = fork())) {
343: case -1:
344: error("%s: fork: %.100s", __func__, strerror(errno));
345: #ifdef USE_PIPES
346: close(pin[0]);
347: close(pin[1]);
348: close(pout[0]);
349: close(pout[1]);
350: close(perr[0]);
351: close(perr[1]);
352: #else
353: close(inout[0]);
354: close(inout[1]);
355: close(err[0]);
356: close(err[1]);
357: #endif
358: return -1;
359: case 0:
360: is_child = 1;
361:
362: /* Child. Reinitialize the log since the pid has changed. */
363: log_init(__progname, options.log_level,
364: options.log_facility, log_stderr);
365:
366: /*
367: * Create a new session and process group since the 4.4BSD
368: * setlogin() affects the entire process group.
369: */
370: if (setsid() < 0)
371: error("setsid failed: %.100s", strerror(errno));
372:
373: #ifdef USE_PIPES
374: /*
375: * Redirect stdin. We close the parent side of the socket
376: * pair, and make the child side the standard input.
377: */
378: close(pin[1]);
379: if (dup2(pin[0], 0) < 0)
380: perror("dup2 stdin");
381: close(pin[0]);
382:
383: /* Redirect stdout. */
384: close(pout[0]);
385: if (dup2(pout[1], 1) < 0)
386: perror("dup2 stdout");
387: close(pout[1]);
388:
389: /* Redirect stderr. */
390: close(perr[0]);
391: if (dup2(perr[1], 2) < 0)
392: perror("dup2 stderr");
393: close(perr[1]);
394: #else
395: /*
396: * Redirect stdin, stdout, and stderr. Stdin and stdout will
397: * use the same socket, as some programs (particularly rdist)
398: * seem to depend on it.
399: */
400: close(inout[1]);
401: close(err[1]);
402: if (dup2(inout[0], 0) < 0) /* stdin */
403: perror("dup2 stdin");
404: if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */
405: perror("dup2 stdout");
406: close(inout[0]);
407: if (dup2(err[0], 2) < 0) /* stderr */
408: perror("dup2 stderr");
409: close(err[0]);
410: #endif
411:
412: /* Do processing for the child (exec command etc). */
413: do_child(s, command);
414: /* NOTREACHED */
415: default:
416: break;
417: }
418:
419: s->pid = pid;
420: /* Set interactive/non-interactive mode. */
1.7 christos 421: packet_set_interactive(s->display != NULL,
422: options.ip_qos_interactive, options.ip_qos_bulk);
1.1 christos 423:
424: #ifdef USE_PIPES
425: /* We are the parent. Close the child sides of the pipes. */
426: close(pin[0]);
427: close(pout[1]);
428: close(perr[1]);
429:
1.8.4.1 ! snj 430: session_set_fds(s, pin[1], pout[0], perr[0],
! 431: s->is_subsystem, 0);
1.1 christos 432: #else
433: /* We are the parent. Close the child sides of the socket pairs. */
434: close(inout[0]);
435: close(err[0]);
436:
437: /*
438: * Enter the interactive session. Note: server_loop must be able to
439: * handle the case that fdin and fdout are the same.
440: */
1.8.4.1 ! snj 441: session_set_fds(s, inout[1], inout[1], err[1],
! 442: s->is_subsystem, 0);
1.1 christos 443: #endif
444: return 0;
445: }
446:
447: /*
448: * This is called to fork and execute a command when we have a tty. This
449: * will call do_child from the child, and server_loop from the parent after
450: * setting up file descriptors, controlling tty, updating wtmp, utmp,
451: * lastlog, and other such operations.
452: */
453: int
454: do_exec_pty(Session *s, const char *command)
455: {
456: int fdout, ptyfd, ttyfd, ptymaster;
457: pid_t pid;
458:
459: if (s == NULL)
460: fatal("do_exec_pty: no session");
461: ptyfd = s->ptyfd;
462: ttyfd = s->ttyfd;
463:
1.2 christos 464: #if defined(USE_PAM)
465: if (options.use_pam) {
466: do_pam_set_tty(s->tty);
467: if (!use_privsep)
468: do_pam_setcred(1);
469: }
470: #endif
471:
1.1 christos 472: /*
473: * Create another descriptor of the pty master side for use as the
474: * standard input. We could use the original descriptor, but this
475: * simplifies code in server_loop. The descriptor is bidirectional.
476: * Do this before forking (and cleanup in the child) so as to
477: * detect and gracefully fail out-of-fd conditions.
478: */
479: if ((fdout = dup(ptyfd)) < 0) {
480: error("%s: dup #1: %s", __func__, strerror(errno));
481: close(ttyfd);
482: close(ptyfd);
483: return -1;
484: }
485: /* we keep a reference to the pty master */
486: if ((ptymaster = dup(ptyfd)) < 0) {
487: error("%s: dup #2: %s", __func__, strerror(errno));
488: close(ttyfd);
489: close(ptyfd);
490: close(fdout);
491: return -1;
492: }
493:
494: /* Fork the child. */
495: switch ((pid = fork())) {
496: case -1:
497: error("%s: fork: %.100s", __func__, strerror(errno));
498: close(fdout);
499: close(ptymaster);
500: close(ttyfd);
501: close(ptyfd);
502: return -1;
503: case 0:
504: is_child = 1;
505:
506: close(fdout);
507: close(ptymaster);
508:
509: /* Child. Reinitialize the log because the pid has changed. */
510: log_init(__progname, options.log_level,
511: options.log_facility, log_stderr);
512: /* Close the master side of the pseudo tty. */
513: close(ptyfd);
514:
515: /* Make the pseudo tty our controlling tty. */
516: pty_make_controlling_tty(&ttyfd, s->tty);
517:
518: /* Redirect stdin/stdout/stderr from the pseudo tty. */
519: if (dup2(ttyfd, 0) < 0)
520: error("dup2 stdin: %s", strerror(errno));
521: if (dup2(ttyfd, 1) < 0)
522: error("dup2 stdout: %s", strerror(errno));
523: if (dup2(ttyfd, 2) < 0)
524: error("dup2 stderr: %s", strerror(errno));
525:
526: /* Close the extra descriptor for the pseudo tty. */
527: close(ttyfd);
528:
529: /* record login, etc. similar to login(1) */
1.8.4.1 ! snj 530: do_login(s, command);
1.1 christos 531:
532: /*
533: * Do common processing for the child, such as execing
534: * the command.
535: */
536: do_child(s, command);
537: /* NOTREACHED */
538: default:
539: break;
540: }
541: s->pid = pid;
542:
543: /* Parent. Close the slave side of the pseudo tty. */
544: close(ttyfd);
545:
546: /* Enter interactive session. */
547: s->ptymaster = ptymaster;
1.7 christos 548: packet_set_interactive(1,
549: options.ip_qos_interactive, options.ip_qos_bulk);
1.8.4.1 ! snj 550: session_set_fds(s, ptyfd, fdout, -1, 1, 1);
1.1 christos 551: return 0;
552: }
553:
554: /*
555: * This is called to fork and execute a command. If another command is
556: * to be forced, execute that instead.
557: */
558: int
559: do_exec(Session *s, const char *command)
560: {
1.8.4.1 ! snj 561: struct ssh *ssh = active_state; /* XXX */
1.1 christos 562: int ret;
1.8.4.1 ! snj 563: const char *forced = NULL, *tty = NULL;
! 564: char session_type[1024];
1.1 christos 565:
566: if (options.adm_forced_command) {
567: original_command = command;
568: command = options.adm_forced_command;
1.8.4.1 ! snj 569: forced = "(config)";
1.1 christos 570: } else if (forced_command) {
571: original_command = command;
572: command = forced_command;
1.8.4.1 ! snj 573: forced = "(key-option)";
! 574: }
! 575: if (forced != NULL) {
1.4 adam 576: if (IS_INTERNAL_SFTP(command)) {
577: s->is_subsystem = s->is_subsystem ?
578: SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
579: } else if (s->is_subsystem)
1.1 christos 580: s->is_subsystem = SUBSYSTEM_EXT;
1.8.4.1 ! snj 581: snprintf(session_type, sizeof(session_type),
! 582: "forced-command %s '%.900s'", forced, command);
! 583: } else if (s->is_subsystem) {
! 584: snprintf(session_type, sizeof(session_type),
! 585: "subsystem '%.900s'", s->subsys);
! 586: } else if (command == NULL) {
! 587: snprintf(session_type, sizeof(session_type), "shell");
! 588: } else {
! 589: /* NB. we don't log unforced commands to preserve privacy */
! 590: snprintf(session_type, sizeof(session_type), "command");
! 591: }
! 592:
! 593: if (s->ttyfd != -1) {
! 594: tty = s->tty;
! 595: if (strncmp(tty, "/dev/", 5) == 0)
! 596: tty += 5;
1.1 christos 597: }
598:
1.8.4.1 ! snj 599: verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
! 600: session_type,
! 601: tty == NULL ? "" : " on ",
! 602: tty == NULL ? "" : tty,
! 603: s->pw->pw_name,
! 604: ssh_remote_ipaddr(ssh),
! 605: ssh_remote_port(ssh),
! 606: s->self);
! 607:
1.1 christos 608: #ifdef GSSAPI
609: if (options.gss_authentication) {
610: temporarily_use_uid(s->pw);
611: ssh_gssapi_storecreds();
612: restore_uid();
613: }
614: #endif
615: if (s->ttyfd != -1)
616: ret = do_exec_pty(s, command);
617: else
618: ret = do_exec_no_pty(s, command);
619:
620: original_command = NULL;
621:
622: /*
623: * Clear loginmsg: it's the child's responsibility to display
624: * it to the user, otherwise multiple sessions may accumulate
625: * multiple copies of the login messages.
626: */
627: buffer_clear(&loginmsg);
628:
629: return ret;
630: }
631:
632:
633: /* administrative, login(1)-like work */
634: void
635: do_login(Session *s, const char *command)
636: {
1.8.4.1 ! snj 637: struct ssh *ssh = active_state; /* XXX */
1.1 christos 638: socklen_t fromlen;
639: struct sockaddr_storage from;
640: struct passwd * pw = s->pw;
641: pid_t pid = getpid();
642:
643: /*
644: * Get IP address of client. If the connection is not a socket, let
645: * the address be 0.0.0.0.
646: */
647: memset(&from, 0, sizeof(from));
648: fromlen = sizeof(from);
649: if (packet_connection_is_on_socket()) {
650: if (getpeername(packet_get_connection_in(),
651: (struct sockaddr *)&from, &fromlen) < 0) {
652: debug("getpeername: %.100s", strerror(errno));
653: cleanup_exit(255);
654: }
655: }
656:
657: /* Record that there was a login on that tty from the remote host. */
658: if (!use_privsep)
659: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.8.4.1 ! snj 660: session_get_remote_name_or_ip(ssh, utmp_len,
1.1 christos 661: options.use_dns),
662: (struct sockaddr *)&from, fromlen);
663:
1.2 christos 664: #ifdef USE_PAM
665: /*
666: * If password change is needed, do it now.
667: * This needs to occur before the ~/.hushlogin check.
668: */
669: if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
670: display_loginmsg();
671: do_pam_chauthtok();
672: s->authctxt->force_pwchange = 0;
673: /* XXX - signal [net] parent to enable forwardings */
674: }
675: #endif
676:
1.1 christos 677: if (check_quietlogin(s, command))
678: return;
679:
680: display_loginmsg();
681:
682: do_motd();
683: }
684:
685: /*
686: * Display the message of the day.
687: */
688: void
689: do_motd(void)
690: {
691: FILE *f;
692: char buf[256];
693:
694: if (options.print_motd) {
1.2 christos 695: #ifdef HAVE_LOGIN_CAP
1.7 christos 696: f = fopen(login_getcapstr(lc, "welcome", __UNCONST("/etc/motd"),
697: __UNCONST("/etc/motd")), "r");
1.2 christos 698: #else
699: f = fopen("/etc/motd", "r");
700: #endif
1.1 christos 701: if (f) {
702: while (fgets(buf, sizeof(buf), f))
703: fputs(buf, stdout);
704: fclose(f);
705: }
706: }
707: }
708:
709:
710: /*
711: * Check for quiet login, either .hushlogin or command given.
712: */
713: int
714: check_quietlogin(Session *s, const char *command)
715: {
716: char buf[256];
717: struct passwd *pw = s->pw;
718: struct stat st;
719:
720: /* Return 1 if .hushlogin exists or a command given. */
721: if (command != NULL)
722: return 1;
723: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
1.2 christos 724: #ifdef HAVE_LOGIN_CAP
1.1 christos 725: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
726: return 1;
1.2 christos 727: #else
728: if (stat(buf, &st) >= 0)
729: return 1;
730: #endif
1.1 christos 731: return 0;
732: }
733:
734: /*
735: * Sets the value of the given variable in the environment. If the variable
736: * already exists, its value is overridden.
737: */
738: void
739: child_set_env(char ***envp, u_int *envsizep, const char *name,
740: const char *value)
741: {
742: char **env;
743: u_int envsize;
744: u_int i, namelen;
745:
1.8.4.1 ! snj 746: if (strchr(name, '=') != NULL) {
! 747: error("Invalid environment variable \"%.100s\"", name);
! 748: return;
! 749: }
! 750:
1.1 christos 751: /*
752: * Find the slot where the value should be stored. If the variable
753: * already exists, we reuse the slot; otherwise we append a new slot
754: * at the end of the array, expanding if necessary.
755: */
756: env = *envp;
757: namelen = strlen(name);
758: for (i = 0; env[i]; i++)
759: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
760: break;
761: if (env[i]) {
762: /* Reuse the slot. */
1.8.4.1 ! snj 763: free(env[i]);
1.1 christos 764: } else {
765: /* New variable. Expand if necessary. */
766: envsize = *envsizep;
767: if (i >= envsize - 1) {
768: if (envsize >= 1000)
769: fatal("child_set_env: too many env vars");
770: envsize += 50;
1.8.4.1 ! snj 771: env = (*envp) = xreallocarray(env, envsize, sizeof(char *));
1.1 christos 772: *envsizep = envsize;
773: }
774: /* Need to set the NULL pointer at end of array beyond the new slot. */
775: env[i + 1] = NULL;
776: }
777:
778: /* Allocate space and format the variable in the appropriate slot. */
779: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
780: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
781: }
782:
783: /*
784: * Reads environment variables from the given file and adds/overrides them
785: * into the environment. If the file does not exist, this does nothing.
786: * Otherwise, it must consist of empty lines, comments (line starts with '#')
787: * and assignments of the form name=value. No other forms are allowed.
788: */
789: static void
790: read_environment_file(char ***env, u_int *envsize,
791: const char *filename)
792: {
793: FILE *f;
794: char buf[4096];
795: char *cp, *value;
796: u_int lineno = 0;
797:
798: f = fopen(filename, "r");
799: if (!f)
800: return;
801:
802: while (fgets(buf, sizeof(buf), f)) {
803: if (++lineno > 1000)
804: fatal("Too many lines in environment file %s", filename);
805: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
806: ;
807: if (!*cp || *cp == '#' || *cp == '\n')
808: continue;
809:
810: cp[strcspn(cp, "\n")] = '\0';
811:
812: value = strchr(cp, '=');
813: if (value == NULL) {
814: fprintf(stderr, "Bad line %u in %.100s\n", lineno,
815: filename);
816: continue;
817: }
818: /*
819: * Replace the equals sign by nul, and advance value to
820: * the value string.
821: */
822: *value = '\0';
823: value++;
824: child_set_env(env, envsize, cp, value);
825: }
826: fclose(f);
827: }
828:
1.2 christos 829: #ifdef USE_PAM
830: void copy_environment(char **, char ***, u_int *);
831: void copy_environment(char **source, char ***env, u_int *envsize)
832: {
833: char *var_name, *var_val;
834: int i;
835:
836: if (source == NULL)
837: return;
838:
839: for (i = 0; source[i] != NULL; i++) {
840: var_name = xstrdup(source[i]);
841: if ((var_val = strstr(var_name, "=")) == NULL) {
1.8.4.1 ! snj 842: free(var_name);
1.2 christos 843: continue;
844: }
845: *var_val++ = '\0';
846:
847: debug3("Copy environment: %s=%s", var_name, var_val);
848: child_set_env(env, envsize, var_name, var_val);
849:
1.8.4.1 ! snj 850: free(var_name);
1.2 christos 851: }
852: }
853: #endif
854:
1.1 christos 855: static char **
856: do_setup_env(Session *s, const char *shell)
857: {
1.8.4.1 ! snj 858: struct ssh *ssh = active_state; /* XXX */
1.1 christos 859: char buf[256];
860: u_int i, envsize;
861: char **env, *laddr;
862: struct passwd *pw = s->pw;
863:
864: /* Initialize the environment. */
865: envsize = 100;
866: env = xcalloc(envsize, sizeof(char *));
867: env[0] = NULL;
868:
869: #ifdef GSSAPI
870: /* Allow any GSSAPI methods that we've used to alter
871: * the childs environment as they see fit
872: */
873: ssh_gssapi_do_child(&env, &envsize);
874: #endif
875:
1.8.4.1 ! snj 876: /* Set basic environment. */
! 877: for (i = 0; i < s->num_env; i++)
! 878: child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
! 879:
! 880: child_set_env(&env, &envsize, "USER", pw->pw_name);
! 881: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
! 882: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
! 883: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
1.2 christos 884: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.8.4.1 ! snj 885: else
! 886: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.1 christos 887:
1.8.4.1 ! snj 888: snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
! 889: child_set_env(&env, &envsize, "MAIL", buf);
! 890:
! 891: /* Normal systems set SHELL by default. */
! 892: child_set_env(&env, &envsize, "SHELL", shell);
1.1 christos 893:
894: if (getenv("TZ"))
895: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
896:
897: /* Set custom environment options from RSA authentication. */
1.8.4.1 ! snj 898: while (custom_environment) {
! 899: struct envstring *ce = custom_environment;
! 900: char *str = ce->s;
! 901:
! 902: for (i = 0; str[i] != '=' && str[i]; i++)
! 903: ;
! 904: if (str[i] == '=') {
! 905: str[i] = 0;
! 906: child_set_env(&env, &envsize, str, str + i + 1);
! 907: }
! 908: custom_environment = ce->next;
! 909: free(ce->s);
! 910: free(ce);
1.1 christos 911: }
912:
913: /* SSH_CLIENT deprecated */
914: snprintf(buf, sizeof buf, "%.50s %d %d",
1.8.4.1 ! snj 915: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
! 916: ssh_local_port(ssh));
1.1 christos 917: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
918:
919: laddr = get_local_ipaddr(packet_get_connection_in());
920: snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
1.8.4.1 ! snj 921: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
! 922: laddr, ssh_local_port(ssh));
! 923: free(laddr);
1.1 christos 924: child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
925:
926: if (s->ttyfd != -1)
927: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
928: if (s->term)
929: child_set_env(&env, &envsize, "TERM", s->term);
930: if (s->display)
931: child_set_env(&env, &envsize, "DISPLAY", s->display);
932: if (original_command)
933: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
934: original_command);
1.2 christos 935: #ifdef KRB4
936: if (s->authctxt->krb4_ticket_file)
937: child_set_env(&env, &envsize, "KRBTKFILE",
938: s->authctxt->krb4_ticket_file);
939: #endif
1.1 christos 940: #ifdef KRB5
941: if (s->authctxt->krb5_ticket_file)
942: child_set_env(&env, &envsize, "KRB5CCNAME",
943: s->authctxt->krb5_ticket_file);
944: #endif
1.2 christos 945: #ifdef USE_PAM
946: /*
947: * Pull in any environment variables that may have
948: * been set by PAM.
949: */
950: if (options.use_pam) {
951: char **p;
952:
953: p = fetch_pam_child_environment();
954: copy_environment(p, &env, &envsize);
955: free_pam_environment(p);
956:
957: p = fetch_pam_environment();
958: copy_environment(p, &env, &envsize);
959: free_pam_environment(p);
960: }
961: #endif /* USE_PAM */
962:
1.1 christos 963: if (auth_sock_name != NULL)
964: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
965: auth_sock_name);
966:
967: /* read $HOME/.ssh/environment. */
1.8.4.1 ! snj 968: if (options.permit_user_env) {
1.1 christos 969: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
970: pw->pw_dir);
971: read_environment_file(&env, &envsize, buf);
972: }
973: if (debug_flag) {
974: /* dump the environment */
975: fprintf(stderr, "Environment:\n");
976: for (i = 0; env[i]; i++)
977: fprintf(stderr, " %.200s\n", env[i]);
978: }
979: return env;
980: }
981:
982: /*
983: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
984: * first in this order).
985: */
986: static void
987: do_rc_files(Session *s, const char *shell)
988: {
989: FILE *f = NULL;
990: char cmd[1024];
991: int do_xauth;
992: struct stat st;
993:
994: do_xauth =
995: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
996:
997: /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
998: if (!s->is_subsystem && options.adm_forced_command == NULL &&
1.8.4.1 ! snj 999: !no_user_rc && options.permit_user_rc &&
! 1000: stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.1 christos 1001: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1002: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1003: if (debug_flag)
1004: fprintf(stderr, "Running %s\n", cmd);
1005: f = popen(cmd, "w");
1006: if (f) {
1007: if (do_xauth)
1008: fprintf(f, "%s %s\n", s->auth_proto,
1009: s->auth_data);
1010: pclose(f);
1011: } else
1012: fprintf(stderr, "Could not run %s\n",
1013: _PATH_SSH_USER_RC);
1014: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1015: if (debug_flag)
1016: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1017: _PATH_SSH_SYSTEM_RC);
1018: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1019: if (f) {
1020: if (do_xauth)
1021: fprintf(f, "%s %s\n", s->auth_proto,
1022: s->auth_data);
1023: pclose(f);
1024: } else
1025: fprintf(stderr, "Could not run %s\n",
1026: _PATH_SSH_SYSTEM_RC);
1027: } else if (do_xauth && options.xauth_location != NULL) {
1028: /* Add authority data to .Xauthority if appropriate. */
1029: if (debug_flag) {
1030: fprintf(stderr,
1031: "Running %.500s remove %.100s\n",
1032: options.xauth_location, s->auth_display);
1033: fprintf(stderr,
1034: "%.500s add %.100s %.100s %.100s\n",
1035: options.xauth_location, s->auth_display,
1036: s->auth_proto, s->auth_data);
1037: }
1038: snprintf(cmd, sizeof cmd, "%s -q -",
1039: options.xauth_location);
1040: f = popen(cmd, "w");
1041: if (f) {
1042: fprintf(f, "remove %s\n",
1043: s->auth_display);
1044: fprintf(f, "add %s %s %s\n",
1045: s->auth_display, s->auth_proto,
1046: s->auth_data);
1047: pclose(f);
1048: } else {
1049: fprintf(stderr, "Could not run %s\n",
1050: cmd);
1051: }
1052: }
1053: }
1054:
1055: static void
1056: do_nologin(struct passwd *pw)
1057: {
1058: FILE *f = NULL;
1.7 christos 1059: char buf[1024], *nl, *def_nl = __UNCONST(_PATH_NOLOGIN);
1.4 adam 1060: struct stat sb;
1.1 christos 1061:
1.2 christos 1062: #ifdef HAVE_LOGIN_CAP
1.8.4.1 ! snj 1063: if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
1.4 adam 1064: return;
1065: nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
1.8.4.1 ! snj 1066: #else
! 1067: if (pw->pw_uid == 0)
! 1068: return;
! 1069: nl = def_nl;
! 1070: #endif
1.4 adam 1071: if (stat(nl, &sb) == -1) {
1072: if (nl != def_nl)
1.8.4.1 ! snj 1073: free(nl);
1.4 adam 1074: return;
1075: }
1.8.4.1 ! snj 1076:
1.4 adam 1077: /* /etc/nologin exists. Print its contents if we can and exit. */
1078: logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
1079: if ((f = fopen(nl, "r")) != NULL) {
1.1 christos 1080: while (fgets(buf, sizeof(buf), f))
1081: fputs(buf, stderr);
1082: fclose(f);
1083: }
1.4 adam 1084: exit(254);
1.1 christos 1085: }
1086:
1087: /*
1088: * Chroot into a directory after checking it for safety: all path components
1089: * must be root-owned directories with strict permissions.
1090: */
1091: static void
1092: safely_chroot(const char *path, uid_t uid)
1093: {
1094: const char *cp;
1.8.4.1 ! snj 1095: char component[PATH_MAX];
1.1 christos 1096: struct stat st;
1097:
1098: if (*path != '/')
1099: fatal("chroot path does not begin at root");
1100: if (strlen(path) >= sizeof(component))
1101: fatal("chroot path too long");
1102:
1103: /*
1104: * Descend the path, checking that each component is a
1105: * root-owned directory with strict permissions.
1106: */
1107: for (cp = path; cp != NULL;) {
1108: if ((cp = strchr(cp, '/')) == NULL)
1109: strlcpy(component, path, sizeof(component));
1110: else {
1111: cp++;
1112: memcpy(component, path, cp - path);
1113: component[cp - path] = '\0';
1114: }
1115:
1116: debug3("%s: checking '%s'", __func__, component);
1117:
1118: if (stat(component, &st) != 0)
1119: fatal("%s: stat(\"%s\"): %s", __func__,
1120: component, strerror(errno));
1121: if (st.st_uid != 0 || (st.st_mode & 022) != 0)
1122: fatal("bad ownership or modes for chroot "
1123: "directory %s\"%s\"",
1124: cp == NULL ? "" : "component ", component);
1125: if (!S_ISDIR(st.st_mode))
1126: fatal("chroot path %s\"%s\" is not a directory",
1127: cp == NULL ? "" : "component ", component);
1128:
1129: }
1130:
1131: if (chdir(path) == -1)
1132: fatal("Unable to chdir to chroot path \"%s\": "
1133: "%s", path, strerror(errno));
1134: if (chroot(path) == -1)
1135: fatal("chroot(\"%s\"): %s", path, strerror(errno));
1136: if (chdir("/") == -1)
1137: fatal("%s: chdir(/) after chroot: %s",
1138: __func__, strerror(errno));
1139: verbose("Changed root directory to \"%s\"", path);
1140: }
1141:
1142: /* Set login name, uid, gid, and groups. */
1143: void
1144: do_setusercontext(struct passwd *pw)
1145: {
1146: char *chroot_path, *tmp;
1147:
1148: if (getuid() == 0 || geteuid() == 0) {
1.2 christos 1149: #ifdef HAVE_LOGIN_CAP
1150: # ifdef USE_PAM
1151: if (options.use_pam) {
1152: do_pam_setcred(use_privsep);
1153: }
1154: # endif /* USE_PAM */
1.1 christos 1155: /* Prepare groups */
1156: if (setusercontext(lc, pw, pw->pw_uid,
1157: (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
1158: perror("unable to set user context");
1159: exit(1);
1160: }
1.2 christos 1161: #else
1.1 christos 1162:
1.2 christos 1163: if (setlogin(pw->pw_name) < 0)
1164: error("setlogin failed: %s", strerror(errno));
1165: if (setgid(pw->pw_gid) < 0) {
1166: perror("setgid");
1167: exit(1);
1168: }
1169: /* Initialize the group list. */
1170: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1171: perror("initgroups");
1172: exit(1);
1173: }
1174: endgrent();
1175: # ifdef USE_PAM
1176: /*
1177: * PAM credentials may take the form of supplementary groups.
1178: * These will have been wiped by the above initgroups() call.
1179: * Reestablish them here.
1180: */
1181: if (options.use_pam) {
1182: do_pam_setcred(use_privsep);
1183: }
1184: # endif /* USE_PAM */
1185: #endif
1.8.4.1 ! snj 1186: if (!in_chroot && options.chroot_directory != NULL &&
1.1 christos 1187: strcasecmp(options.chroot_directory, "none") != 0) {
1188: tmp = tilde_expand_filename(options.chroot_directory,
1189: pw->pw_uid);
1190: chroot_path = percent_expand(tmp, "h", pw->pw_dir,
1191: "u", pw->pw_name, (char *)NULL);
1192: safely_chroot(chroot_path, pw->pw_uid);
1193: free(tmp);
1194: free(chroot_path);
1.8.4.1 ! snj 1195: /* Make sure we don't attempt to chroot again */
! 1196: free(options.chroot_directory);
! 1197: options.chroot_directory = NULL;
! 1198: in_chroot = 1;
1.1 christos 1199: }
1200:
1.2 christos 1201: #ifdef HAVE_LOGIN_CAP
1.1 christos 1202: /* Set UID */
1203: if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
1204: perror("unable to set user context (setuser)");
1205: exit(1);
1206: }
1.2 christos 1207: #else
1208: /* Permanently switch to the desired uid. */
1209: permanently_set_uid(pw);
1210: #endif
1.8.4.1 ! snj 1211: } else if (options.chroot_directory != NULL &&
! 1212: strcasecmp(options.chroot_directory, "none") != 0) {
! 1213: fatal("server lacks privileges to chroot to ChrootDirectory");
1.1 christos 1214: }
1.8.4.1 ! snj 1215:
1.1 christos 1216: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1217: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1218: }
1219:
1.8 joerg 1220: __dead static void
1.1 christos 1221: do_pwchange(Session *s)
1222: {
1223: fflush(NULL);
1224: fprintf(stderr, "WARNING: Your password has expired.\n");
1225: if (s->ttyfd != -1) {
1226: fprintf(stderr,
1227: "You must change your password now and login again!\n");
1228: execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
1229: perror("passwd");
1230: } else {
1231: fprintf(stderr,
1232: "Password change required but no TTY available.\n");
1233: }
1234: exit(1);
1235: }
1236:
1237: static void
1238: child_close_fds(void)
1239: {
1.8.4.1 ! snj 1240: extern int auth_sock;
! 1241:
! 1242: if (auth_sock != -1) {
! 1243: close(auth_sock);
! 1244: auth_sock = -1;
! 1245: }
! 1246:
1.1 christos 1247: if (packet_get_connection_in() == packet_get_connection_out())
1248: close(packet_get_connection_in());
1249: else {
1250: close(packet_get_connection_in());
1251: close(packet_get_connection_out());
1252: }
1253: /*
1254: * Close all descriptors related to channels. They will still remain
1255: * open in the parent.
1256: */
1257: /* XXX better use close-on-exec? -markus */
1258: channel_close_all();
1259:
1260: /*
1261: * Close any extra file descriptors. Note that there may still be
1262: * descriptors left by system functions. They will be closed later.
1263: */
1264: endpwent();
1265:
1266: /*
1267: * Close any extra open file descriptors so that we don't have them
1268: * hanging around in clients. Note that we want to do this after
1269: * initgroups, because at least on Solaris 2.3 it leaves file
1270: * descriptors open.
1271: */
1.8.4.1 ! snj 1272: (void)closefrom(STDERR_FILENO + 1);
1.1 christos 1273: }
1274:
1275: /*
1276: * Performs common processing for the child, such as setting up the
1277: * environment, closing extra file descriptors, setting the user and group
1278: * ids, and executing the command or shell.
1279: */
1280: #define ARGV_MAX 10
1281: void
1282: do_child(Session *s, const char *command)
1283: {
1284: extern char **environ;
1285: char **env;
1286: char *argv[ARGV_MAX];
1.8.4.1 ! snj 1287: const char *shell, *shell0;
1.1 christos 1288: struct passwd *pw = s->pw;
1289: int r = 0;
1290:
1291: /* remove hostkey from the child's memory */
1292: destroy_sensitive_data();
1293:
1294: /* Force a password change */
1295: if (s->authctxt->force_pwchange) {
1296: do_setusercontext(pw);
1297: child_close_fds();
1298: do_pwchange(s);
1299: }
1300:
1301: /*
1302: * Login(1) does this as well, and it needs uid 0 for the "-h"
1303: * switch, so we let login(1) to this for us.
1304: */
1.2 christos 1305: #ifdef USE_PAM
1306: if (options.use_pam && !is_pam_session_open()) {
1307: debug3("PAM session not opened, exiting");
1308: display_loginmsg();
1309: exit(254);
1.1 christos 1310: }
1.2 christos 1311: #endif
1.8.4.1 ! snj 1312: do_nologin(pw);
! 1313: do_setusercontext(pw);
1.1 christos 1314:
1315: /*
1316: * Get the shell from the password data. An empty shell field is
1317: * legal, and means /bin/sh.
1318: */
1319: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1320:
1321: /*
1322: * Make sure $SHELL points to the shell from the password file,
1323: * even if shell is overridden from login.conf
1324: */
1325: env = do_setup_env(s, shell);
1326:
1.2 christos 1327: #ifdef HAVE_LOGIN_CAP
1.7 christos 1328: shell = login_getcapstr(lc, "shell", __UNCONST(shell),
1329: __UNCONST(shell));
1.2 christos 1330: #endif
1.1 christos 1331:
1332: /*
1333: * Close the connection descriptors; note that this is the child, and
1334: * the server will still have the socket open, and it is important
1335: * that we do not shutdown it. Note that the descriptors cannot be
1336: * closed before building the environment, as we call
1.8.4.1 ! snj 1337: * ssh_remote_ipaddr there.
1.1 christos 1338: */
1339: child_close_fds();
1340:
1341: /*
1342: * Must take new environment into use so that .ssh/rc,
1343: * /etc/ssh/sshrc and xauth are run in the proper environment.
1344: */
1345: environ = env;
1346:
1347: #ifdef KRB5
1348: /*
1349: * At this point, we check to see if AFS is active and if we have
1350: * a valid Kerberos 5 TGT. If so, it seems like a good idea to see
1351: * if we can (and need to) extend the ticket into an AFS token. If
1352: * we don't do this, we run into potential problems if the user's
1353: * home directory is in AFS and it's not world-readable.
1354: */
1355:
1356: if (options.kerberos_get_afs_token && k_hasafs() &&
1357: (s->authctxt->krb5_ctx != NULL)) {
1358: char cell[64];
1359:
1360: debug("Getting AFS token");
1361:
1362: k_setpag();
1363:
1364: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1365: krb5_afslog(s->authctxt->krb5_ctx,
1366: s->authctxt->krb5_fwd_ccache, cell, NULL);
1367:
1368: krb5_afslog_home(s->authctxt->krb5_ctx,
1369: s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
1370: }
1371: #endif
1372:
1373: /* Change current directory to the user's home directory. */
1374: if (chdir(pw->pw_dir) < 0) {
1375: /* Suppress missing homedir warning for chroot case */
1376: r = login_getcapbool(lc, "requirehome", 0);
1.8.4.1 ! snj 1377: if (r || !in_chroot) {
1.1 christos 1378: fprintf(stderr, "Could not chdir to home "
1379: "directory %s: %s\n", pw->pw_dir,
1380: strerror(errno));
1.8.4.1 ! snj 1381: }
1.1 christos 1382: if (r)
1383: exit(1);
1384: }
1385:
1.8.4.1 ! snj 1386: (void)closefrom(STDERR_FILENO + 1);
1.1 christos 1387:
1.8.4.1 ! snj 1388: do_rc_files(s, shell);
1.1 christos 1389:
1390: /* restore SIGPIPE for child */
1391: signal(SIGPIPE, SIG_DFL);
1392:
1.4 adam 1393: if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
1394: printf("This service allows sftp connections only.\n");
1395: fflush(NULL);
1396: exit(1);
1397: } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
1.1 christos 1398: extern int optind, optreset;
1399: int i;
1400: char *p, *args;
1401:
1.3 christos 1402: setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
1.1 christos 1403: args = xstrdup(command ? command : "sftp-server");
1404: for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
1405: if (i < ARGV_MAX - 1)
1406: argv[i++] = p;
1407: argv[i] = NULL;
1408: optind = optreset = 1;
1409: __progname = argv[0];
1410: exit(sftp_server_main(i, argv, s->pw));
1411: }
1412:
1.4 adam 1413: fflush(NULL);
1414:
1.1 christos 1415: /* Get the last component of the shell name. */
1416: if ((shell0 = strrchr(shell, '/')) != NULL)
1417: shell0++;
1418: else
1419: shell0 = shell;
1420:
1421: /*
1422: * If we have no command, execute the shell. In this case, the shell
1423: * name to be passed in argv[0] is preceded by '-' to indicate that
1424: * this is a login shell.
1425: */
1426: if (!command) {
1427: char argv0[256];
1428:
1429: /* Start the shell. Set initial character to '-'. */
1430: argv0[0] = '-';
1431:
1432: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1433: >= sizeof(argv0) - 1) {
1434: errno = EINVAL;
1435: perror(shell);
1436: exit(1);
1437: }
1438:
1439: /* Execute the shell. */
1440: argv[0] = argv0;
1441: argv[1] = NULL;
1442: execve(shell, argv, env);
1443:
1444: /* Executing the shell failed. */
1445: perror(shell);
1446: exit(1);
1447: }
1448: /*
1449: * Execute the command using the user's shell. This uses the -c
1450: * option to execute the command.
1451: */
1.7 christos 1452: argv[0] = __UNCONST(shell0);
1453: argv[1] = __UNCONST("-c");
1454: argv[2] = __UNCONST(command);
1.1 christos 1455: argv[3] = NULL;
1456: execve(shell, argv, env);
1457: perror(shell);
1458: exit(1);
1459: }
1460:
1461: void
1462: session_unused(int id)
1463: {
1464: debug3("%s: session id %d unused", __func__, id);
1465: if (id >= options.max_sessions ||
1466: id >= sessions_nalloc) {
1467: fatal("%s: insane session id %d (max %d nalloc %d)",
1468: __func__, id, options.max_sessions, sessions_nalloc);
1469: }
1.8.4.1 ! snj 1470: memset(&sessions[id], 0, sizeof(*sessions));
1.1 christos 1471: sessions[id].self = id;
1472: sessions[id].used = 0;
1473: sessions[id].chanid = -1;
1474: sessions[id].ptyfd = -1;
1475: sessions[id].ttyfd = -1;
1476: sessions[id].ptymaster = -1;
1477: sessions[id].x11_chanids = NULL;
1478: sessions[id].next_unused = sessions_first_unused;
1479: sessions_first_unused = id;
1480: }
1481:
1482: Session *
1483: session_new(void)
1484: {
1485: Session *s, *tmp;
1486:
1487: if (sessions_first_unused == -1) {
1488: if (sessions_nalloc >= options.max_sessions)
1489: return NULL;
1490: debug2("%s: allocate (allocated %d max %d)",
1491: __func__, sessions_nalloc, options.max_sessions);
1.8.4.1 ! snj 1492: tmp = xreallocarray(sessions, sessions_nalloc + 1,
1.1 christos 1493: sizeof(*sessions));
1494: if (tmp == NULL) {
1495: error("%s: cannot allocate %d sessions",
1496: __func__, sessions_nalloc + 1);
1497: return NULL;
1498: }
1499: sessions = tmp;
1500: session_unused(sessions_nalloc++);
1501: }
1502:
1503: if (sessions_first_unused >= sessions_nalloc ||
1504: sessions_first_unused < 0) {
1505: fatal("%s: insane first_unused %d max %d nalloc %d",
1506: __func__, sessions_first_unused, options.max_sessions,
1507: sessions_nalloc);
1508: }
1509:
1510: s = &sessions[sessions_first_unused];
1511: if (s->used) {
1512: fatal("%s: session %d already used",
1513: __func__, sessions_first_unused);
1514: }
1515: sessions_first_unused = s->next_unused;
1516: s->used = 1;
1517: s->next_unused = -1;
1518: debug("session_new: session %d", s->self);
1519:
1520: return s;
1521: }
1522:
1523: static void
1524: session_dump(void)
1525: {
1526: int i;
1527: for (i = 0; i < sessions_nalloc; i++) {
1528: Session *s = &sessions[i];
1529:
1530: debug("dump: used %d next_unused %d session %d %p "
1531: "channel %d pid %ld",
1532: s->used,
1533: s->next_unused,
1534: s->self,
1535: s,
1536: s->chanid,
1537: (long)s->pid);
1538: }
1539: }
1540:
1541: int
1542: session_open(Authctxt *authctxt, int chanid)
1543: {
1544: Session *s = session_new();
1545: debug("session_open: channel %d", chanid);
1546: if (s == NULL) {
1547: error("no more sessions");
1548: return 0;
1549: }
1550: s->authctxt = authctxt;
1551: s->pw = authctxt->pw;
1552: if (s->pw == NULL || !authctxt->valid)
1553: fatal("no user for session %d", s->self);
1554: debug("session_open: session %d: link with channel %d", s->self, chanid);
1555: s->chanid = chanid;
1556: return 1;
1557: }
1558:
1559: Session *
1560: session_by_tty(char *tty)
1561: {
1562: int i;
1563: for (i = 0; i < sessions_nalloc; i++) {
1564: Session *s = &sessions[i];
1565: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1566: debug("session_by_tty: session %d tty %s", i, tty);
1567: return s;
1568: }
1569: }
1570: debug("session_by_tty: unknown tty %.100s", tty);
1571: session_dump();
1572: return NULL;
1573: }
1574:
1575: static Session *
1576: session_by_channel(int id)
1577: {
1578: int i;
1579: for (i = 0; i < sessions_nalloc; i++) {
1580: Session *s = &sessions[i];
1581: if (s->used && s->chanid == id) {
1582: debug("session_by_channel: session %d channel %d",
1583: i, id);
1584: return s;
1585: }
1586: }
1587: debug("session_by_channel: unknown channel %d", id);
1588: session_dump();
1589: return NULL;
1590: }
1591:
1592: static Session *
1593: session_by_x11_channel(int id)
1594: {
1595: int i, j;
1596:
1597: for (i = 0; i < sessions_nalloc; i++) {
1598: Session *s = &sessions[i];
1599:
1600: if (s->x11_chanids == NULL || !s->used)
1601: continue;
1602: for (j = 0; s->x11_chanids[j] != -1; j++) {
1603: if (s->x11_chanids[j] == id) {
1604: debug("session_by_x11_channel: session %d "
1605: "channel %d", s->self, id);
1606: return s;
1607: }
1608: }
1609: }
1610: debug("session_by_x11_channel: unknown channel %d", id);
1611: session_dump();
1612: return NULL;
1613: }
1614:
1615: static Session *
1616: session_by_pid(pid_t pid)
1617: {
1618: int i;
1619: debug("session_by_pid: pid %ld", (long)pid);
1620: for (i = 0; i < sessions_nalloc; i++) {
1621: Session *s = &sessions[i];
1622: if (s->used && s->pid == pid)
1623: return s;
1624: }
1625: error("session_by_pid: unknown pid %ld", (long)pid);
1626: session_dump();
1627: return NULL;
1628: }
1629:
1630: static int
1631: session_window_change_req(Session *s)
1632: {
1633: s->col = packet_get_int();
1634: s->row = packet_get_int();
1635: s->xpixel = packet_get_int();
1636: s->ypixel = packet_get_int();
1637: packet_check_eom();
1638: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1639: return 1;
1640: }
1641:
1642: static int
1643: session_pty_req(Session *s)
1644: {
1645: u_int len;
1646: int n_bytes;
1647:
1.8.4.1 ! snj 1648: if (no_pty_flag || !options.permit_tty) {
1.1 christos 1649: debug("Allocating a pty not permitted for this authentication.");
1650: return 0;
1651: }
1652: if (s->ttyfd != -1) {
1653: packet_disconnect("Protocol error: you already have a pty.");
1654: return 0;
1655: }
1656:
1657: s->term = packet_get_string(&len);
1.8.4.1 ! snj 1658: s->col = packet_get_int();
! 1659: s->row = packet_get_int();
1.1 christos 1660: s->xpixel = packet_get_int();
1661: s->ypixel = packet_get_int();
1662:
1663: if (strcmp(s->term, "") == 0) {
1.8.4.1 ! snj 1664: free(s->term);
1.1 christos 1665: s->term = NULL;
1666: }
1667:
1668: /* Allocate a pty and open it. */
1669: debug("Allocating pty.");
1670: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
1671: sizeof(s->tty)))) {
1.8.4.1 ! snj 1672: free(s->term);
1.1 christos 1673: s->term = NULL;
1674: s->ptyfd = -1;
1675: s->ttyfd = -1;
1676: error("session_pty_req: session %d alloc failed", s->self);
1677: return 0;
1678: }
1679: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1680:
1.8.4.1 ! snj 1681: n_bytes = packet_remaining();
1.1 christos 1682: tty_parse_modes(s->ttyfd, &n_bytes);
1683:
1684: if (!use_privsep)
1685: pty_setowner(s->pw, s->tty);
1686:
1687: /* Set window size from the packet. */
1688: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1689:
1690: packet_check_eom();
1691: session_proctitle(s);
1692: return 1;
1693: }
1694:
1695: static int
1696: session_subsystem_req(Session *s)
1697: {
1698: struct stat st;
1699: u_int len;
1700: int success = 0;
1.8.4.1 ! snj 1701: char *prog, *cmd;
1.1 christos 1702: u_int i;
1703:
1.8.4.1 ! snj 1704: s->subsys = packet_get_string(&len);
1.1 christos 1705: packet_check_eom();
1.8.4.1 ! snj 1706: debug2("subsystem request for %.100s by user %s", s->subsys,
1.4 adam 1707: s->pw->pw_name);
1.1 christos 1708:
1709: for (i = 0; i < options.num_subsystems; i++) {
1.8.4.1 ! snj 1710: if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
1.1 christos 1711: prog = options.subsystem_command[i];
1712: cmd = options.subsystem_args[i];
1.4 adam 1713: if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
1.1 christos 1714: s->is_subsystem = SUBSYSTEM_INT_SFTP;
1.4 adam 1715: debug("subsystem: %s", prog);
1.1 christos 1716: } else {
1.4 adam 1717: if (stat(prog, &st) < 0)
1718: debug("subsystem: cannot stat %s: %s",
1719: prog, strerror(errno));
1.1 christos 1720: s->is_subsystem = SUBSYSTEM_EXT;
1.4 adam 1721: debug("subsystem: exec() %s", cmd);
1.1 christos 1722: }
1723: success = do_exec(s, cmd) == 0;
1724: break;
1725: }
1726: }
1727:
1728: if (!success)
1.8.4.1 ! snj 1729: logit("subsystem request for %.100s by user %s failed, "
! 1730: "subsystem not found", s->subsys, s->pw->pw_name);
1.1 christos 1731:
1732: return success;
1733: }
1734:
1735: static int
1736: session_x11_req(Session *s)
1737: {
1738: int success;
1739:
1740: if (s->auth_proto != NULL || s->auth_data != NULL) {
1741: error("session_x11_req: session %d: "
1742: "x11 forwarding already active", s->self);
1743: return 0;
1744: }
1745: s->single_connection = packet_get_char();
1746: s->auth_proto = packet_get_string(NULL);
1747: s->auth_data = packet_get_string(NULL);
1748: s->screen = packet_get_int();
1749: packet_check_eom();
1750:
1.8.4.1 ! snj 1751: if (xauth_valid_string(s->auth_proto) &&
! 1752: xauth_valid_string(s->auth_data))
! 1753: success = session_setup_x11fwd(s);
! 1754: else {
! 1755: success = 0;
! 1756: error("Invalid X11 forwarding data");
! 1757: }
1.1 christos 1758: if (!success) {
1.8.4.1 ! snj 1759: free(s->auth_proto);
! 1760: free(s->auth_data);
1.1 christos 1761: s->auth_proto = NULL;
1762: s->auth_data = NULL;
1763: }
1764: return success;
1765: }
1766:
1767: static int
1768: session_shell_req(Session *s)
1769: {
1770: packet_check_eom();
1771: return do_exec(s, NULL) == 0;
1772: }
1773:
1774: static int
1775: session_exec_req(Session *s)
1776: {
1777: u_int len, success;
1778:
1779: char *command = packet_get_string(&len);
1780: packet_check_eom();
1781: success = do_exec(s, command) == 0;
1.8.4.1 ! snj 1782: free(command);
1.1 christos 1783: return success;
1784: }
1785:
1786: static int
1787: session_break_req(Session *s)
1788: {
1789:
1790: packet_get_int(); /* ignored */
1791: packet_check_eom();
1792:
1.8.4.1 ! snj 1793: if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0)
1.1 christos 1794: return 0;
1795: return 1;
1796: }
1797:
1798: static int
1799: session_env_req(Session *s)
1800: {
1801: char *name, *val;
1802: u_int name_len, val_len, i;
1803:
1.8.4.1 ! snj 1804: name = packet_get_cstring(&name_len);
! 1805: val = packet_get_cstring(&val_len);
1.1 christos 1806: packet_check_eom();
1807:
1808: /* Don't set too many environment variables */
1809: if (s->num_env > 128) {
1810: debug2("Ignoring env request %s: too many env vars", name);
1811: goto fail;
1812: }
1813:
1814: for (i = 0; i < options.num_accept_env; i++) {
1815: if (match_pattern(name, options.accept_env[i])) {
1816: debug2("Setting env %d: %s=%s", s->num_env, name, val);
1.8.4.1 ! snj 1817: s->env = xreallocarray(s->env, s->num_env + 1,
1.1 christos 1818: sizeof(*s->env));
1819: s->env[s->num_env].name = name;
1820: s->env[s->num_env].val = val;
1821: s->num_env++;
1822: return (1);
1823: }
1824: }
1825: debug2("Ignoring env request %s: disallowed name", name);
1826:
1827: fail:
1.8.4.1 ! snj 1828: free(name);
! 1829: free(val);
1.1 christos 1830: return (0);
1831: }
1832:
1833: static int
1834: session_auth_agent_req(Session *s)
1835: {
1836: static int called = 0;
1837: packet_check_eom();
1838: if (no_agent_forwarding_flag || !options.allow_agent_forwarding) {
1839: debug("session_auth_agent_req: no_agent_forwarding_flag");
1840: return 0;
1841: }
1842: if (called) {
1843: return 0;
1844: } else {
1845: called = 1;
1846: return auth_input_request_forwarding(s->pw);
1847: }
1848: }
1849:
1850: int
1851: session_input_channel_req(Channel *c, const char *rtype)
1852: {
1853: int success = 0;
1854: Session *s;
1855:
1856: if ((s = session_by_channel(c->self)) == NULL) {
1857: logit("session_input_channel_req: no session %d req %.100s",
1858: c->self, rtype);
1859: return 0;
1860: }
1861: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1862:
1863: /*
1864: * a session is in LARVAL state until a shell, a command
1865: * or a subsystem is executed
1866: */
1867: if (c->type == SSH_CHANNEL_LARVAL) {
1868: if (strcmp(rtype, "shell") == 0) {
1869: success = session_shell_req(s);
1870: } else if (strcmp(rtype, "exec") == 0) {
1871: success = session_exec_req(s);
1872: } else if (strcmp(rtype, "pty-req") == 0) {
1873: success = session_pty_req(s);
1874: } else if (strcmp(rtype, "x11-req") == 0) {
1875: success = session_x11_req(s);
1876: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1877: success = session_auth_agent_req(s);
1878: } else if (strcmp(rtype, "subsystem") == 0) {
1879: success = session_subsystem_req(s);
1880: } else if (strcmp(rtype, "env") == 0) {
1881: success = session_env_req(s);
1882: }
1883: }
1884: if (strcmp(rtype, "window-change") == 0) {
1885: success = session_window_change_req(s);
1886: } else if (strcmp(rtype, "break") == 0) {
1887: success = session_break_req(s);
1888: }
1889:
1890: return success;
1891: }
1892:
1893: void
1.4 adam 1894: session_set_fds(Session *s, int fdin, int fdout, int fderr, int ignore_fderr,
1895: int is_tty)
1.1 christos 1896: {
1897: /*
1898: * now that have a child and a pipe to the child,
1899: * we can activate our channel and register the fd's
1900: */
1901: if (s->chanid == -1)
1902: fatal("no channel for session %d", s->self);
1.2 christos 1903: if(options.hpn_disabled)
1.1 christos 1904: channel_set_fds(s->chanid,
1905: fdout, fdin, fderr,
1.4 adam 1906: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.1 christos 1907: 1, is_tty, CHAN_SES_WINDOW_DEFAULT);
1.2 christos 1908: else
1909: channel_set_fds(s->chanid,
1910: fdout, fdin, fderr,
1.5 adam 1911: ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.2 christos 1912: 1, is_tty, options.hpn_buffer_size);
1.1 christos 1913: }
1914:
1915: /*
1916: * Function to perform pty cleanup. Also called if we get aborted abnormally
1917: * (e.g., due to a dropped connection).
1918: */
1919: void
1920: session_pty_cleanup2(Session *s)
1921: {
1922: if (s == NULL) {
1923: error("session_pty_cleanup: no session");
1924: return;
1925: }
1926: if (s->ttyfd == -1)
1927: return;
1928:
1929: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1930:
1931: /* Record that the user has logged out. */
1932: if (s->pid != 0)
1933: record_logout(s->pid, s->tty);
1934:
1935: /* Release the pseudo-tty. */
1936: if (getuid() == 0)
1937: pty_release(s->tty);
1938:
1939: /*
1940: * Close the server side of the socket pairs. We must do this after
1941: * the pty cleanup, so that another process doesn't get this pty
1942: * while we're still cleaning up.
1943: */
1944: if (s->ptymaster != -1 && close(s->ptymaster) < 0)
1945: error("close(s->ptymaster/%d): %s",
1946: s->ptymaster, strerror(errno));
1947:
1948: /* unlink pty from session */
1949: s->ttyfd = -1;
1950: }
1951:
1952: void
1953: session_pty_cleanup(Session *s)
1954: {
1955: PRIVSEP(session_pty_cleanup2(s));
1956: }
1957:
1.7 christos 1958: static const char *
1.1 christos 1959: sig2name(int sig)
1960: {
1961: #define SSH_SIG(x) if (sig == SIG ## x) return #x
1962: SSH_SIG(ABRT);
1963: SSH_SIG(ALRM);
1964: SSH_SIG(FPE);
1965: SSH_SIG(HUP);
1966: SSH_SIG(ILL);
1967: SSH_SIG(INT);
1968: SSH_SIG(KILL);
1969: SSH_SIG(PIPE);
1970: SSH_SIG(QUIT);
1971: SSH_SIG(SEGV);
1972: SSH_SIG(TERM);
1973: SSH_SIG(USR1);
1974: SSH_SIG(USR2);
1975: #undef SSH_SIG
1976: return "SIG@openssh.com";
1977: }
1978:
1979: static void
1980: session_close_x11(int id)
1981: {
1982: Channel *c;
1983:
1984: if ((c = channel_by_id(id)) == NULL) {
1985: debug("session_close_x11: x11 channel %d missing", id);
1986: } else {
1987: /* Detach X11 listener */
1988: debug("session_close_x11: detach x11 channel %d", id);
1989: channel_cancel_cleanup(id);
1990: if (c->ostate != CHAN_OUTPUT_CLOSED)
1991: chan_mark_dead(c);
1992: }
1993: }
1994:
1995: static void
1996: session_close_single_x11(int id, void *arg)
1997: {
1998: Session *s;
1999: u_int i;
2000:
2001: debug3("session_close_single_x11: channel %d", id);
2002: channel_cancel_cleanup(id);
2003: if ((s = session_by_x11_channel(id)) == NULL)
2004: fatal("session_close_single_x11: no x11 channel %d", id);
2005: for (i = 0; s->x11_chanids[i] != -1; i++) {
2006: debug("session_close_single_x11: session %d: "
2007: "closing channel %d", s->self, s->x11_chanids[i]);
2008: /*
2009: * The channel "id" is already closing, but make sure we
2010: * close all of its siblings.
2011: */
2012: if (s->x11_chanids[i] != id)
2013: session_close_x11(s->x11_chanids[i]);
2014: }
1.8.4.1 ! snj 2015: free(s->x11_chanids);
1.1 christos 2016: s->x11_chanids = NULL;
1.8.4.1 ! snj 2017: free(s->display);
! 2018: s->display = NULL;
! 2019: free(s->auth_proto);
! 2020: s->auth_proto = NULL;
! 2021: free(s->auth_data);
! 2022: s->auth_data = NULL;
! 2023: free(s->auth_display);
! 2024: s->auth_display = NULL;
1.1 christos 2025: }
2026:
2027: static void
2028: session_exit_message(Session *s, int status)
2029: {
2030: Channel *c;
2031:
2032: if ((c = channel_lookup(s->chanid)) == NULL)
2033: fatal("session_exit_message: session %d: no channel %d",
2034: s->self, s->chanid);
2035: debug("session_exit_message: session %d channel %d pid %ld",
2036: s->self, s->chanid, (long)s->pid);
2037:
2038: if (WIFEXITED(status)) {
2039: channel_request_start(s->chanid, "exit-status", 0);
2040: packet_put_int(WEXITSTATUS(status));
2041: packet_send();
2042: } else if (WIFSIGNALED(status)) {
2043: channel_request_start(s->chanid, "exit-signal", 0);
2044: packet_put_cstring(sig2name(WTERMSIG(status)));
2045: packet_put_char(WCOREDUMP(status)? 1 : 0);
2046: packet_put_cstring("");
2047: packet_put_cstring("");
2048: packet_send();
2049: } else {
2050: /* Some weird exit cause. Just exit. */
2051: packet_disconnect("wait returned status %04x.", status);
2052: }
2053:
2054: /* disconnect channel */
2055: debug("session_exit_message: release channel %d", s->chanid);
2056:
2057: /*
2058: * Adjust cleanup callback attachment to send close messages when
2059: * the channel gets EOF. The session will be then be closed
2060: * by session_close_by_channel when the childs close their fds.
2061: */
2062: channel_register_cleanup(c->self, session_close_by_channel, 1);
2063:
2064: /*
2065: * emulate a write failure with 'chan_write_failed', nobody will be
2066: * interested in data we write.
2067: * Note that we must not call 'chan_read_failed', since there could
2068: * be some more data waiting in the pipe.
2069: */
2070: if (c->ostate != CHAN_OUTPUT_CLOSED)
2071: chan_write_failed(c);
2072: }
2073:
2074: void
2075: session_close(Session *s)
2076: {
1.8.4.1 ! snj 2077: struct ssh *ssh = active_state; /* XXX */
1.1 christos 2078: u_int i;
2079:
1.8.4.1 ! snj 2080: verbose("Close session: user %s from %.200s port %d id %d",
! 2081: s->pw->pw_name,
! 2082: ssh_remote_ipaddr(ssh),
! 2083: ssh_remote_port(ssh),
! 2084: s->self);
! 2085:
1.1 christos 2086: if (s->ttyfd != -1)
2087: session_pty_cleanup(s);
1.8.4.1 ! snj 2088: free(s->term);
! 2089: free(s->display);
! 2090: free(s->x11_chanids);
! 2091: free(s->auth_display);
! 2092: free(s->auth_data);
! 2093: free(s->auth_proto);
! 2094: free(s->subsys);
1.1 christos 2095: if (s->env != NULL) {
2096: for (i = 0; i < s->num_env; i++) {
1.8.4.1 ! snj 2097: free(s->env[i].name);
! 2098: free(s->env[i].val);
1.1 christos 2099: }
1.8.4.1 ! snj 2100: free(s->env);
1.1 christos 2101: }
2102: session_proctitle(s);
2103: session_unused(s->self);
2104: }
2105:
2106: void
2107: session_close_by_pid(pid_t pid, int status)
2108: {
2109: Session *s = session_by_pid(pid);
2110: if (s == NULL) {
2111: debug("session_close_by_pid: no session for pid %ld",
2112: (long)pid);
2113: return;
2114: }
2115: if (s->chanid != -1)
2116: session_exit_message(s, status);
2117: if (s->ttyfd != -1)
2118: session_pty_cleanup(s);
2119: s->pid = 0;
2120: }
2121:
2122: /*
2123: * this is called when a channel dies before
2124: * the session 'child' itself dies
2125: */
2126: void
2127: session_close_by_channel(int id, void *arg)
2128: {
2129: Session *s = session_by_channel(id);
2130: u_int i;
2131:
2132: if (s == NULL) {
2133: debug("session_close_by_channel: no session for id %d", id);
2134: return;
2135: }
2136: debug("session_close_by_channel: channel %d child %ld",
2137: id, (long)s->pid);
2138: if (s->pid != 0) {
2139: debug("session_close_by_channel: channel %d: has child", id);
2140: /*
2141: * delay detach of session, but release pty, since
2142: * the fd's to the child are already closed
2143: */
2144: if (s->ttyfd != -1)
2145: session_pty_cleanup(s);
2146: return;
2147: }
2148: /* detach by removing callback */
2149: channel_cancel_cleanup(s->chanid);
2150:
2151: /* Close any X11 listeners associated with this session */
2152: if (s->x11_chanids != NULL) {
2153: for (i = 0; s->x11_chanids[i] != -1; i++) {
2154: session_close_x11(s->x11_chanids[i]);
2155: s->x11_chanids[i] = -1;
2156: }
2157: }
2158:
2159: s->chanid = -1;
2160: session_close(s);
2161: }
2162:
2163: void
2164: session_destroy_all(void (*closefunc)(Session *))
2165: {
2166: int i;
2167: for (i = 0; i < sessions_nalloc; i++) {
2168: Session *s = &sessions[i];
2169: if (s->used) {
2170: if (closefunc != NULL)
2171: closefunc(s);
2172: else
2173: session_close(s);
2174: }
2175: }
2176: }
2177:
2178: static char *
2179: session_tty_list(void)
2180: {
2181: static char buf[1024];
2182: int i;
2183: buf[0] = '\0';
2184: for (i = 0; i < sessions_nalloc; i++) {
2185: Session *s = &sessions[i];
2186: if (s->used && s->ttyfd != -1) {
1.2 christos 2187: char *p;
1.1 christos 2188: if (buf[0] != '\0')
2189: strlcat(buf, ",", sizeof buf);
1.2 christos 2190: if ((p = strstr(s->tty, "/pts/")) != NULL)
2191: p++;
2192: else {
2193: if ((p = strrchr(s->tty, '/')) != NULL)
2194: p++;
2195: else
2196: p = s->tty;
2197: }
2198: strlcat(buf, p, sizeof buf);
1.1 christos 2199: }
2200: }
2201: if (buf[0] == '\0')
2202: strlcpy(buf, "notty", sizeof buf);
2203: return buf;
2204: }
2205:
2206: void
2207: session_proctitle(Session *s)
2208: {
2209: if (s->pw == NULL)
2210: error("no user for session %d", s->self);
2211: else
2212: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2213: }
2214:
2215: int
2216: session_setup_x11fwd(Session *s)
2217: {
2218: struct stat st;
2219: char display[512], auth_display[512];
1.8.4.1 ! snj 2220: char hostname[NI_MAXHOST];
1.1 christos 2221: u_int i;
2222:
2223: if (no_x11_forwarding_flag) {
2224: packet_send_debug("X11 forwarding disabled in user configuration file.");
2225: return 0;
2226: }
2227: if (!options.x11_forwarding) {
2228: debug("X11 forwarding disabled in server configuration file.");
2229: return 0;
2230: }
1.8.4.1 ! snj 2231: if (options.xauth_location == NULL ||
1.1 christos 2232: (stat(options.xauth_location, &st) == -1)) {
2233: packet_send_debug("No xauth program; cannot forward with spoofing.");
2234: return 0;
2235: }
2236: if (s->display != NULL) {
2237: debug("X11 display already set.");
2238: return 0;
2239: }
2240: if (x11_create_display_inet(options.x11_display_offset,
2241: options.x11_use_localhost, s->single_connection,
2242: &s->display_number, &s->x11_chanids) == -1) {
2243: debug("x11_create_display_inet failed.");
2244: return 0;
2245: }
2246: for (i = 0; s->x11_chanids[i] != -1; i++) {
2247: channel_register_cleanup(s->x11_chanids[i],
2248: session_close_single_x11, 0);
2249: }
2250:
2251: /* Set up a suitable value for the DISPLAY variable. */
2252: if (gethostname(hostname, sizeof(hostname)) < 0)
2253: fatal("gethostname: %.100s", strerror(errno));
2254: /*
2255: * auth_display must be used as the displayname when the
2256: * authorization entry is added with xauth(1). This will be
2257: * different than the DISPLAY string for localhost displays.
2258: */
2259: if (options.x11_use_localhost) {
2260: snprintf(display, sizeof display, "localhost:%u.%u",
2261: s->display_number, s->screen);
2262: snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
2263: s->display_number, s->screen);
2264: s->display = xstrdup(display);
2265: s->auth_display = xstrdup(auth_display);
2266: } else {
2267: snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
2268: s->display_number, s->screen);
2269: s->display = xstrdup(display);
2270: s->auth_display = xstrdup(display);
2271: }
2272:
2273: return 1;
2274: }
2275:
2276: static void
2277: do_authenticated2(Authctxt *authctxt)
2278: {
2279: server_loop2(authctxt);
2280: }
2281:
2282: void
2283: do_cleanup(Authctxt *authctxt)
2284: {
2285: static int called = 0;
2286:
2287: debug("do_cleanup");
2288:
2289: /* no cleanup if we're in the child for login shell */
2290: if (is_child)
2291: return;
2292:
2293: /* avoid double cleanup */
2294: if (called)
2295: return;
2296: called = 1;
2297:
2298: if (authctxt == NULL || !authctxt->authenticated)
2299: return;
1.2 christos 2300: #ifdef KRB4
2301: if (options.kerberos_ticket_cleanup)
2302: krb4_cleanup_proc(authctxt);
2303: #endif
1.1 christos 2304: #ifdef KRB5
2305: if (options.kerberos_ticket_cleanup &&
2306: authctxt->krb5_ctx)
2307: krb5_cleanup_proc(authctxt);
2308: #endif
2309:
2310: #ifdef GSSAPI
1.8.4.1 ! snj 2311: if (options.gss_cleanup_creds)
1.1 christos 2312: ssh_gssapi_cleanup_creds();
2313: #endif
2314:
1.2 christos 2315: #ifdef USE_PAM
2316: if (options.use_pam) {
2317: sshpam_cleanup();
2318: sshpam_thread_cleanup();
2319: }
2320: #endif
2321:
1.1 christos 2322: /* remove agent socket */
2323: auth_sock_cleanup_proc(authctxt->pw);
2324:
2325: /*
2326: * Cleanup ptys/utmp only if privsep is disabled,
2327: * or if running in monitor.
2328: */
2329: if (!use_privsep || mm_is_monitor())
2330: session_destroy_all(session_pty_cleanup2);
2331: }
1.8.4.1 ! snj 2332:
! 2333: /* Return a name for the remote host that fits inside utmp_size */
! 2334:
! 2335: const char *
! 2336: session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
! 2337: {
! 2338: const char *remote = "";
! 2339:
! 2340: if (utmp_size > 0)
! 2341: remote = auth_get_canonical_hostname(ssh, use_dns);
! 2342: if (utmp_size == 0 || strlen(remote) > utmp_size)
! 2343: remote = ssh_remote_ipaddr(ssh);
! 2344: return remote;
! 2345: }
! 2346:
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