Annotation of src/usr.bin/ssh/session.c, Revision 1.133
1.1 markus 1: /*
2: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
3: * All rights reserved
1.37 deraadt 4: *
5: * As far as I am concerned, the code I have written for this software
6: * can be used freely for any purpose. Any derived versions of this
7: * software must be clearly marked as such, and if the derived work is
8: * incompatible with the protocol description in the RFC file, it must be
9: * called by a name other than "ssh" or "Secure Shell".
10: *
1.2 markus 11: * SSH2 support by Markus Friedl.
1.95 markus 12: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.37 deraadt 13: *
14: * Redistribution and use in source and binary forms, with or without
15: * modification, are permitted provided that the following conditions
16: * are met:
17: * 1. Redistributions of source code must retain the above copyright
18: * notice, this list of conditions and the following disclaimer.
19: * 2. Redistributions in binary form must reproduce the above copyright
20: * notice, this list of conditions and the following disclaimer in the
21: * documentation and/or other materials provided with the distribution.
22: *
23: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.2 markus 33: */
1.1 markus 34:
35: #include "includes.h"
1.133 ! markus 36: RCSID("$OpenBSD: session.c,v 1.132 2002/03/19 10:49:35 markus Exp $");
1.1 markus 37:
1.51 markus 38: #include "ssh.h"
39: #include "ssh1.h"
40: #include "ssh2.h"
1.1 markus 41: #include "xmalloc.h"
1.59 djm 42: #include "sshpty.h"
1.1 markus 43: #include "packet.h"
44: #include "buffer.h"
45: #include "mpaux.h"
46: #include "uidswap.h"
47: #include "compat.h"
1.78 markus 48: #include "channels.h"
1.2 markus 49: #include "bufaux.h"
50: #include "auth.h"
1.19 markus 51: #include "auth-options.h"
1.50 markus 52: #include "pathnames.h"
1.51 markus 53: #include "log.h"
54: #include "servconf.h"
1.59 djm 55: #include "sshlogin.h"
1.51 markus 56: #include "serverloop.h"
57: #include "canohost.h"
1.55 itojun 58: #include "session.h"
1.130 provos 59: #include "monitor_wrap.h"
1.1 markus 60:
61: /* func */
62:
63: Session *session_new(void);
1.94 itojun 64: void session_set_fds(Session *, int, int, int);
1.130 provos 65: void session_pty_cleanup(void *);
1.94 itojun 66: void session_proctitle(Session *);
67: int session_setup_x11fwd(Session *);
68: void do_exec_pty(Session *, const char *);
69: void do_exec_no_pty(Session *, const char *);
70: void do_exec(Session *, const char *);
71: void do_login(Session *, const char *);
72: void do_child(Session *, const char *);
1.73 djm 73: void do_motd(void);
1.94 itojun 74: int check_quietlogin(Session *, const char *);
1.1 markus 75:
1.94 itojun 76: static void do_authenticated1(Authctxt *);
77: static void do_authenticated2(Authctxt *);
78:
79: static int session_pty_req(Session *);
1.65 markus 80:
1.1 markus 81: /* import */
82: extern ServerOptions options;
83: extern char *__progname;
84: extern int log_stderr;
85: extern int debug_flag;
1.45 markus 86: extern u_int utmp_len;
1.21 markus 87: extern int startup_pipe;
1.74 markus 88: extern void destroy_sensitive_data(void);
1.21 markus 89:
1.34 markus 90: /* original command from peer. */
1.92 markus 91: const char *original_command = NULL;
1.34 markus 92:
1.1 markus 93: /* data */
94: #define MAX_SESSIONS 10
95: Session sessions[MAX_SESSIONS];
96:
1.28 millert 97: #ifdef HAVE_LOGIN_CAP
1.129 provos 98: login_cap_t *lc;
1.28 millert 99: #endif
100:
1.65 markus 101: void
102: do_authenticated(Authctxt *authctxt)
103: {
104: /*
105: * Cancel the alarm we set to limit the time taken for
106: * authentication.
107: */
108: alarm(0);
109: if (startup_pipe != -1) {
110: close(startup_pipe);
111: startup_pipe = -1;
112: }
113: /* setup the channel layer */
114: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
115: channel_permit_all_opens();
116:
117: if (compat20)
118: do_authenticated2(authctxt);
119: else
120: do_authenticated1(authctxt);
1.79 markus 121:
1.87 markus 122: /* remove agent socket */
1.79 markus 123: if (auth_get_socket_name())
1.80 markus 124: auth_sock_cleanup_proc(authctxt->pw);
1.96 dugsong 125: #ifdef KRB4
126: if (options.kerberos_ticket_cleanup)
127: krb4_cleanup_proc(authctxt);
128: #endif
129: #ifdef KRB5
130: if (options.kerberos_ticket_cleanup)
131: krb5_cleanup_proc(authctxt);
132: #endif
1.65 markus 133: }
134:
1.1 markus 135: /*
136: * Prepares for an interactive session. This is called after the user has
137: * been successfully authenticated. During this message exchange, pseudo
138: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
139: * are requested, etc.
140: */
1.94 itojun 141: static void
1.65 markus 142: do_authenticated1(Authctxt *authctxt)
1.1 markus 143: {
144: Session *s;
1.65 markus 145: char *command;
1.117 markus 146: int success, type, screen_flag;
1.1 markus 147: int compression_level = 0, enable_compression_after_reply = 0;
1.45 markus 148: u_int proto_len, data_len, dlen;
1.1 markus 149:
1.61 markus 150: s = session_new();
1.96 dugsong 151: s->authctxt = authctxt;
1.65 markus 152: s->pw = authctxt->pw;
1.28 millert 153:
1.1 markus 154: /*
155: * We stay in this loop until the client requests to execute a shell
156: * or a command.
157: */
158: for (;;) {
1.65 markus 159: success = 0;
1.1 markus 160:
161: /* Get a packet from the client. */
1.117 markus 162: type = packet_read();
1.1 markus 163:
164: /* Process the packet. */
165: switch (type) {
166: case SSH_CMSG_REQUEST_COMPRESSION:
167: compression_level = packet_get_int();
1.116 markus 168: packet_check_eom();
1.1 markus 169: if (compression_level < 1 || compression_level > 9) {
170: packet_send_debug("Received illegal compression level %d.",
1.112 deraadt 171: compression_level);
1.1 markus 172: break;
173: }
174: /* Enable compression after we have responded with SUCCESS. */
175: enable_compression_after_reply = 1;
176: success = 1;
177: break;
178:
179: case SSH_CMSG_REQUEST_PTY:
1.86 markus 180: success = session_pty_req(s);
1.1 markus 181: break;
182:
183: case SSH_CMSG_X11_REQUEST_FORWARDING:
184: s->auth_proto = packet_get_string(&proto_len);
185: s->auth_data = packet_get_string(&data_len);
186:
1.57 markus 187: screen_flag = packet_get_protocol_flags() &
188: SSH_PROTOFLAG_SCREEN_NUMBER;
189: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
190:
191: if (packet_remaining() == 4) {
192: if (!screen_flag)
193: debug2("Buggy client: "
194: "X11 screen flag missing");
1.1 markus 195: s->screen = packet_get_int();
1.56 markus 196: } else {
1.1 markus 197: s->screen = 0;
1.56 markus 198: }
1.116 markus 199: packet_check_eom();
1.81 markus 200: success = session_setup_x11fwd(s);
201: if (!success) {
202: xfree(s->auth_proto);
203: xfree(s->auth_data);
1.84 markus 204: s->auth_proto = NULL;
205: s->auth_data = NULL;
1.1 markus 206: }
207: break;
208:
209: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
210: if (no_agent_forwarding_flag || compat13) {
211: debug("Authentication agent forwarding not permitted for this authentication.");
212: break;
213: }
214: debug("Received authentication agent forwarding request.");
1.65 markus 215: success = auth_input_request_forwarding(s->pw);
1.1 markus 216: break;
217:
218: case SSH_CMSG_PORT_FORWARD_REQUEST:
219: if (no_port_forwarding_flag) {
220: debug("Port forwarding not permitted for this authentication.");
1.39 markus 221: break;
222: }
223: if (!options.allow_tcp_forwarding) {
224: debug("Port forwarding not permitted.");
1.1 markus 225: break;
226: }
227: debug("Received TCP/IP port forwarding request.");
1.65 markus 228: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 229: success = 1;
230: break;
231:
232: case SSH_CMSG_MAX_PACKET_SIZE:
233: if (packet_set_maxsize(packet_get_int()) > 0)
234: success = 1;
235: break;
1.112 deraadt 236:
1.96 dugsong 237: #if defined(AFS) || defined(KRB5)
238: case SSH_CMSG_HAVE_KERBEROS_TGT:
239: if (!options.kerberos_tgt_passing) {
240: verbose("Kerberos TGT passing disabled.");
241: } else {
242: char *kdata = packet_get_string(&dlen);
1.116 markus 243: packet_check_eom();
1.112 deraadt 244:
1.96 dugsong 245: /* XXX - 0x41, see creds_to_radix version */
246: if (kdata[0] != 0x41) {
247: #ifdef KRB5
248: krb5_data tgt;
249: tgt.data = kdata;
250: tgt.length = dlen;
1.112 deraadt 251:
1.96 dugsong 252: if (auth_krb5_tgt(s->authctxt, &tgt))
253: success = 1;
254: else
255: verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
256: #endif /* KRB5 */
257: } else {
258: #ifdef AFS
259: if (auth_krb4_tgt(s->authctxt, kdata))
260: success = 1;
261: else
262: verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user);
263: #endif /* AFS */
264: }
265: xfree(kdata);
266: }
267: break;
268: #endif /* AFS || KRB5 */
1.112 deraadt 269:
1.96 dugsong 270: #ifdef AFS
271: case SSH_CMSG_HAVE_AFS_TOKEN:
272: if (!options.afs_token_passing || !k_hasafs()) {
273: verbose("AFS token passing disabled.");
274: } else {
275: /* Accept AFS token. */
276: char *token = packet_get_string(&dlen);
1.116 markus 277: packet_check_eom();
1.112 deraadt 278:
1.96 dugsong 279: if (auth_afs_token(s->authctxt, token))
280: success = 1;
281: else
282: verbose("AFS token refused for %.100s",
283: s->authctxt->user);
284: xfree(token);
285: }
286: break;
287: #endif /* AFS */
1.1 markus 288:
289: case SSH_CMSG_EXEC_SHELL:
290: case SSH_CMSG_EXEC_CMD:
291: if (type == SSH_CMSG_EXEC_CMD) {
292: command = packet_get_string(&dlen);
293: debug("Exec command '%.500s'", command);
1.92 markus 294: do_exec(s, command);
295: xfree(command);
1.1 markus 296: } else {
1.92 markus 297: do_exec(s, NULL);
1.1 markus 298: }
1.116 markus 299: packet_check_eom();
1.82 markus 300: session_close(s);
1.1 markus 301: return;
302:
303: default:
304: /*
305: * Any unknown messages in this phase are ignored,
306: * and a failure message is returned.
307: */
308: log("Unknown packet type received after authentication: %d", type);
309: }
310: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
311: packet_send();
312: packet_write_wait();
313:
314: /* Enable compression now that we have replied if appropriate. */
315: if (enable_compression_after_reply) {
316: enable_compression_after_reply = 0;
317: packet_start_compression(compression_level);
318: }
319: }
320: }
321:
322: /*
323: * This is called to fork and execute a command when we have no tty. This
324: * will call do_child from the child, and server_loop from the parent after
325: * setting up file descriptors and such.
326: */
1.4 markus 327: void
1.63 markus 328: do_exec_no_pty(Session *s, const char *command)
1.1 markus 329: {
330: int pid;
331:
332: #ifdef USE_PIPES
333: int pin[2], pout[2], perr[2];
334: /* Allocate pipes for communicating with the program. */
335: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
336: packet_disconnect("Could not create pipes: %.100s",
337: strerror(errno));
338: #else /* USE_PIPES */
339: int inout[2], err[2];
340: /* Uses socket pairs to communicate with the program. */
341: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
342: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
343: packet_disconnect("Could not create socket pairs: %.100s",
344: strerror(errno));
345: #endif /* USE_PIPES */
346: if (s == NULL)
347: fatal("do_exec_no_pty: no session");
348:
1.9 markus 349: session_proctitle(s);
1.1 markus 350:
351: /* Fork the child. */
352: if ((pid = fork()) == 0) {
353: /* Child. Reinitialize the log since the pid has changed. */
354: log_init(__progname, options.log_level, options.log_facility, log_stderr);
355:
356: /*
357: * Create a new session and process group since the 4.4BSD
358: * setlogin() affects the entire process group.
359: */
360: if (setsid() < 0)
361: error("setsid failed: %.100s", strerror(errno));
362:
363: #ifdef USE_PIPES
364: /*
365: * Redirect stdin. We close the parent side of the socket
366: * pair, and make the child side the standard input.
367: */
368: close(pin[1]);
369: if (dup2(pin[0], 0) < 0)
370: perror("dup2 stdin");
371: close(pin[0]);
372:
373: /* Redirect stdout. */
374: close(pout[0]);
375: if (dup2(pout[1], 1) < 0)
376: perror("dup2 stdout");
377: close(pout[1]);
378:
379: /* Redirect stderr. */
380: close(perr[0]);
381: if (dup2(perr[1], 2) < 0)
382: perror("dup2 stderr");
383: close(perr[1]);
384: #else /* USE_PIPES */
385: /*
386: * Redirect stdin, stdout, and stderr. Stdin and stdout will
387: * use the same socket, as some programs (particularly rdist)
388: * seem to depend on it.
389: */
390: close(inout[1]);
391: close(err[1]);
392: if (dup2(inout[0], 0) < 0) /* stdin */
393: perror("dup2 stdin");
394: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
395: perror("dup2 stdout");
396: if (dup2(err[0], 2) < 0) /* stderr */
397: perror("dup2 stderr");
398: #endif /* USE_PIPES */
399:
400: /* Do processing for the child (exec command etc). */
1.60 markus 401: do_child(s, command);
1.1 markus 402: /* NOTREACHED */
403: }
404: if (pid < 0)
405: packet_disconnect("fork failed: %.100s", strerror(errno));
406: s->pid = pid;
1.47 markus 407: /* Set interactive/non-interactive mode. */
1.48 markus 408: packet_set_interactive(s->display != NULL);
1.1 markus 409: #ifdef USE_PIPES
410: /* We are the parent. Close the child sides of the pipes. */
411: close(pin[0]);
412: close(pout[1]);
413: close(perr[1]);
414:
1.2 markus 415: if (compat20) {
1.64 markus 416: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 417: } else {
418: /* Enter the interactive session. */
419: server_loop(pid, pin[1], pout[0], perr[0]);
1.64 markus 420: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 421: }
1.1 markus 422: #else /* USE_PIPES */
423: /* We are the parent. Close the child sides of the socket pairs. */
424: close(inout[0]);
425: close(err[0]);
426:
427: /*
428: * Enter the interactive session. Note: server_loop must be able to
429: * handle the case that fdin and fdout are the same.
430: */
1.2 markus 431: if (compat20) {
1.64 markus 432: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 433: } else {
434: server_loop(pid, inout[1], inout[1], err[1]);
435: /* server_loop has closed inout[1] and err[1]. */
436: }
1.1 markus 437: #endif /* USE_PIPES */
438: }
439:
440: /*
441: * This is called to fork and execute a command when we have a tty. This
442: * will call do_child from the child, and server_loop from the parent after
443: * setting up file descriptors, controlling tty, updating wtmp, utmp,
444: * lastlog, and other such operations.
445: */
1.4 markus 446: void
1.63 markus 447: do_exec_pty(Session *s, const char *command)
1.1 markus 448: {
449: int fdout, ptyfd, ttyfd, ptymaster;
450: pid_t pid;
451:
452: if (s == NULL)
453: fatal("do_exec_pty: no session");
454: ptyfd = s->ptyfd;
455: ttyfd = s->ttyfd;
456:
457: /* Fork the child. */
458: if ((pid = fork()) == 0) {
1.97 markus 459:
1.24 markus 460: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 461: log_init(__progname, options.log_level, options.log_facility, log_stderr);
462: /* Close the master side of the pseudo tty. */
463: close(ptyfd);
464:
465: /* Make the pseudo tty our controlling tty. */
466: pty_make_controlling_tty(&ttyfd, s->tty);
467:
1.103 markus 468: /* Redirect stdin/stdout/stderr from the pseudo tty. */
469: if (dup2(ttyfd, 0) < 0)
470: error("dup2 stdin: %s", strerror(errno));
471: if (dup2(ttyfd, 1) < 0)
472: error("dup2 stdout: %s", strerror(errno));
473: if (dup2(ttyfd, 2) < 0)
474: error("dup2 stderr: %s", strerror(errno));
1.1 markus 475:
476: /* Close the extra descriptor for the pseudo tty. */
477: close(ttyfd);
478:
1.24 markus 479: /* record login, etc. similar to login(1) */
1.41 markus 480: if (!(options.use_login && command == NULL))
481: do_login(s, command);
1.1 markus 482:
483: /* Do common processing for the child, such as execing the command. */
1.60 markus 484: do_child(s, command);
1.1 markus 485: /* NOTREACHED */
486: }
487: if (pid < 0)
488: packet_disconnect("fork failed: %.100s", strerror(errno));
489: s->pid = pid;
490:
491: /* Parent. Close the slave side of the pseudo tty. */
492: close(ttyfd);
493:
494: /*
495: * Create another descriptor of the pty master side for use as the
496: * standard input. We could use the original descriptor, but this
497: * simplifies code in server_loop. The descriptor is bidirectional.
498: */
499: fdout = dup(ptyfd);
500: if (fdout < 0)
501: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
502:
503: /* we keep a reference to the pty master */
504: ptymaster = dup(ptyfd);
505: if (ptymaster < 0)
506: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
507: s->ptymaster = ptymaster;
508:
509: /* Enter interactive session. */
1.47 markus 510: packet_set_interactive(1);
1.2 markus 511: if (compat20) {
512: session_set_fds(s, ptyfd, fdout, -1);
513: } else {
514: server_loop(pid, ptyfd, fdout, -1);
515: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 516: }
517: }
518:
1.90 markus 519: /*
520: * This is called to fork and execute a command. If another command is
521: * to be forced, execute that instead.
522: */
523: void
524: do_exec(Session *s, const char *command)
525: {
526: if (forced_command) {
527: original_command = command;
528: command = forced_command;
529: debug("Forced command '%.900s'", command);
530: }
531:
532: if (s->ttyfd != -1)
533: do_exec_pty(s, command);
534: else
535: do_exec_no_pty(s, command);
536:
1.92 markus 537: original_command = NULL;
1.90 markus 538: }
539:
540:
1.24 markus 541: /* administrative, login(1)-like work */
542: void
1.41 markus 543: do_login(Session *s, const char *command)
1.24 markus 544: {
545: char *time_string;
1.35 markus 546: char hostname[MAXHOSTNAMELEN];
1.24 markus 547: socklen_t fromlen;
548: struct sockaddr_storage from;
549: time_t last_login_time;
550: struct passwd * pw = s->pw;
551: pid_t pid = getpid();
552:
553: /*
554: * Get IP address of client. If the connection is not a socket, let
555: * the address be 0.0.0.0.
556: */
557: memset(&from, 0, sizeof(from));
558: if (packet_connection_is_on_socket()) {
559: fromlen = sizeof(from);
560: if (getpeername(packet_get_connection_in(),
1.112 deraadt 561: (struct sockaddr *) & from, &fromlen) < 0) {
1.24 markus 562: debug("getpeername: %.100s", strerror(errno));
563: fatal_cleanup();
564: }
565: }
1.25 markus 566:
1.35 markus 567: /* Get the time and hostname when the user last logged in. */
1.69 stevesk 568: if (options.print_lastlog) {
569: hostname[0] = '\0';
570: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
571: hostname, sizeof(hostname));
572: }
1.35 markus 573:
1.24 markus 574: /* Record that there was a login on that tty from the remote host. */
1.133 ! markus 575: if (!use_privsep)
! 576: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
! 577: get_remote_name_or_ip(utmp_len,
! 578: options.verify_reverse_mapping),
! 579: (struct sockaddr *)&from);
1.24 markus 580:
1.73 djm 581: if (check_quietlogin(s, command))
1.24 markus 582: return;
1.73 djm 583:
1.69 stevesk 584: if (options.print_lastlog && last_login_time != 0) {
1.24 markus 585: time_string = ctime(&last_login_time);
586: if (strchr(time_string, '\n'))
587: *strchr(time_string, '\n') = 0;
1.40 markus 588: if (strcmp(hostname, "") == 0)
1.24 markus 589: printf("Last login: %s\r\n", time_string);
590: else
1.36 markus 591: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 592: }
1.73 djm 593:
594: do_motd();
595: }
596:
597: /*
598: * Display the message of the day.
599: */
600: void
601: do_motd(void)
602: {
603: FILE *f;
604: char buf[256];
605:
1.24 markus 606: if (options.print_motd) {
1.28 millert 607: #ifdef HAVE_LOGIN_CAP
608: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
609: "/etc/motd"), "r");
610: #else
1.24 markus 611: f = fopen("/etc/motd", "r");
1.28 millert 612: #endif
1.24 markus 613: if (f) {
614: while (fgets(buf, sizeof(buf), f))
615: fputs(buf, stdout);
616: fclose(f);
617: }
1.2 markus 618: }
1.73 djm 619: }
620:
621:
622: /*
623: * Check for quiet login, either .hushlogin or command given.
624: */
625: int
626: check_quietlogin(Session *s, const char *command)
627: {
628: char buf[256];
1.96 dugsong 629: struct passwd *pw = s->pw;
1.73 djm 630: struct stat st;
631:
632: /* Return 1 if .hushlogin exists or a command given. */
633: if (command != NULL)
634: return 1;
635: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
636: #ifdef HAVE_LOGIN_CAP
637: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
638: return 1;
639: #else
640: if (stat(buf, &st) >= 0)
641: return 1;
642: #endif
643: return 0;
1.1 markus 644: }
645:
646: /*
647: * Sets the value of the given variable in the environment. If the variable
648: * already exists, its value is overriden.
649: */
1.94 itojun 650: static void
1.45 markus 651: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.112 deraadt 652: const char *value)
1.1 markus 653: {
1.45 markus 654: u_int i, namelen;
1.1 markus 655: char **env;
656:
657: /*
658: * Find the slot where the value should be stored. If the variable
659: * already exists, we reuse the slot; otherwise we append a new slot
660: * at the end of the array, expanding if necessary.
661: */
662: env = *envp;
663: namelen = strlen(name);
664: for (i = 0; env[i]; i++)
665: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
666: break;
667: if (env[i]) {
668: /* Reuse the slot. */
669: xfree(env[i]);
670: } else {
671: /* New variable. Expand if necessary. */
672: if (i >= (*envsizep) - 1) {
673: (*envsizep) += 50;
674: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
675: }
676: /* Need to set the NULL pointer at end of array beyond the new slot. */
677: env[i + 1] = NULL;
678: }
679:
680: /* Allocate space and format the variable in the appropriate slot. */
681: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
682: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
683: }
684:
685: /*
686: * Reads environment variables from the given file and adds/overrides them
687: * into the environment. If the file does not exist, this does nothing.
688: * Otherwise, it must consist of empty lines, comments (line starts with '#')
689: * and assignments of the form name=value. No other forms are allowed.
690: */
1.94 itojun 691: static void
1.45 markus 692: read_environment_file(char ***env, u_int *envsize,
1.112 deraadt 693: const char *filename)
1.1 markus 694: {
695: FILE *f;
696: char buf[4096];
697: char *cp, *value;
698:
699: f = fopen(filename, "r");
700: if (!f)
701: return;
702:
703: while (fgets(buf, sizeof(buf), f)) {
704: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
705: ;
706: if (!*cp || *cp == '#' || *cp == '\n')
707: continue;
708: if (strchr(cp, '\n'))
709: *strchr(cp, '\n') = '\0';
710: value = strchr(cp, '=');
711: if (value == NULL) {
712: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
713: continue;
714: }
1.14 deraadt 715: /*
716: * Replace the equals sign by nul, and advance value to
717: * the value string.
718: */
1.1 markus 719: *value = '\0';
720: value++;
721: child_set_env(env, envsize, cp, value);
722: }
723: fclose(f);
724: }
725:
1.127 markus 726: static char **
727: do_setup_env(Session *s, const char *shell)
1.1 markus 728: {
729: char buf[256];
1.127 markus 730: u_int i, envsize;
1.1 markus 731: char **env;
1.127 markus 732: struct passwd *pw = s->pw;
1.1 markus 733:
734: /* Initialize the environment. */
735: envsize = 100;
736: env = xmalloc(envsize * sizeof(char *));
737: env[0] = NULL;
738:
739: if (!options.use_login) {
740: /* Set basic environment. */
741: child_set_env(&env, &envsize, "USER", pw->pw_name);
742: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
743: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 744: #ifdef HAVE_LOGIN_CAP
1.29 millert 745: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
746: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 747: #else
1.29 millert 748: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 749: #endif
1.1 markus 750:
751: snprintf(buf, sizeof buf, "%.200s/%.50s",
752: _PATH_MAILDIR, pw->pw_name);
753: child_set_env(&env, &envsize, "MAIL", buf);
754:
755: /* Normal systems set SHELL by default. */
756: child_set_env(&env, &envsize, "SHELL", shell);
757: }
758: if (getenv("TZ"))
759: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
760:
761: /* Set custom environment options from RSA authentication. */
1.110 markus 762: if (!options.use_login) {
763: while (custom_environment) {
764: struct envstring *ce = custom_environment;
765: char *s = ce->s;
1.127 markus 766:
1.110 markus 767: for (i = 0; s[i] != '=' && s[i]; i++)
768: ;
769: if (s[i] == '=') {
770: s[i] = 0;
771: child_set_env(&env, &envsize, s, s + i + 1);
772: }
773: custom_environment = ce->next;
774: xfree(ce->s);
775: xfree(ce);
1.1 markus 776: }
777: }
778:
779: snprintf(buf, sizeof buf, "%.50s %d %d",
1.127 markus 780: get_remote_ipaddr(), get_remote_port(), get_local_port());
1.1 markus 781: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
782:
1.60 markus 783: if (s->ttyfd != -1)
784: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
785: if (s->term)
786: child_set_env(&env, &envsize, "TERM", s->term);
787: if (s->display)
788: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 789: if (original_command)
790: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
791: original_command);
1.1 markus 792: #ifdef KRB4
1.96 dugsong 793: if (s->authctxt->krb4_ticket_file)
794: child_set_env(&env, &envsize, "KRBTKFILE",
1.112 deraadt 795: s->authctxt->krb4_ticket_file);
1.96 dugsong 796: #endif
797: #ifdef KRB5
798: if (s->authctxt->krb5_ticket_file)
799: child_set_env(&env, &envsize, "KRB5CCNAME",
1.112 deraadt 800: s->authctxt->krb5_ticket_file);
1.96 dugsong 801: #endif
1.1 markus 802: if (auth_get_socket_name() != NULL)
803: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.112 deraadt 804: auth_get_socket_name());
1.1 markus 805:
806: /* read $HOME/.ssh/environment. */
807: if (!options.use_login) {
1.14 deraadt 808: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
809: pw->pw_dir);
1.1 markus 810: read_environment_file(&env, &envsize, buf);
811: }
812: if (debug_flag) {
813: /* dump the environment */
814: fprintf(stderr, "Environment:\n");
815: for (i = 0; env[i]; i++)
816: fprintf(stderr, " %.200s\n", env[i]);
817: }
1.127 markus 818: return env;
819: }
820:
821: /*
822: * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
823: * first in this order).
824: */
825: static void
826: do_rc_files(Session *s, const char *shell)
827: {
828: FILE *f = NULL;
829: char cmd[1024];
830: int do_xauth;
831: struct stat st;
832:
833: do_xauth =
834: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
835:
836: /* ignore _PATH_SSH_USER_RC for subsystems */
837: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
838: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
839: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
840: if (debug_flag)
841: fprintf(stderr, "Running %s\n", cmd);
842: f = popen(cmd, "w");
843: if (f) {
844: if (do_xauth)
845: fprintf(f, "%s %s\n", s->auth_proto,
846: s->auth_data);
847: pclose(f);
848: } else
849: fprintf(stderr, "Could not run %s\n",
850: _PATH_SSH_USER_RC);
851: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
852: if (debug_flag)
853: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
854: _PATH_SSH_SYSTEM_RC);
855: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
856: if (f) {
857: if (do_xauth)
858: fprintf(f, "%s %s\n", s->auth_proto,
859: s->auth_data);
860: pclose(f);
861: } else
862: fprintf(stderr, "Could not run %s\n",
863: _PATH_SSH_SYSTEM_RC);
864: } else if (do_xauth && options.xauth_location != NULL) {
865: /* Add authority data to .Xauthority if appropriate. */
866: if (debug_flag) {
867: fprintf(stderr,
868: "Running %.100s add "
869: "%.100s %.100s %.100s\n",
870: options.xauth_location, s->auth_display,
871: s->auth_proto, s->auth_data);
872: }
873: snprintf(cmd, sizeof cmd, "%s -q -",
874: options.xauth_location);
875: f = popen(cmd, "w");
876: if (f) {
877: fprintf(f, "add %s %s %s\n",
878: s->auth_display, s->auth_proto,
879: s->auth_data);
880: pclose(f);
881: } else {
882: fprintf(stderr, "Could not run %s\n",
883: cmd);
884: }
885: }
886: }
887:
888: static void
889: do_nologin(struct passwd *pw)
890: {
891: FILE *f = NULL;
892: char buf[1024];
893:
894: #ifdef HAVE_LOGIN_CAP
895: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
896: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
897: _PATH_NOLOGIN), "r");
898: #else
899: if (pw->pw_uid)
900: f = fopen(_PATH_NOLOGIN, "r");
901: #endif
902: if (f) {
903: /* /etc/nologin exists. Print its contents and exit. */
904: while (fgets(buf, sizeof(buf), f))
905: fputs(buf, stderr);
906: fclose(f);
907: exit(254);
908: }
909: }
910:
911: /* Set login name, uid, gid, and groups. */
1.130 provos 912: void
1.127 markus 913: do_setusercontext(struct passwd *pw)
914: {
915: if (getuid() == 0 || geteuid() == 0) {
916: #ifdef HAVE_LOGIN_CAP
917: if (setusercontext(lc, pw, pw->pw_uid,
918: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
919: perror("unable to set user context");
920: exit(1);
921: }
922: #else
923: if (setlogin(pw->pw_name) < 0)
924: error("setlogin failed: %s", strerror(errno));
925: if (setgid(pw->pw_gid) < 0) {
926: perror("setgid");
927: exit(1);
928: }
929: /* Initialize the group list. */
930: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
931: perror("initgroups");
932: exit(1);
933: }
934: endgrent();
935:
936: /* Permanently switch to the desired uid. */
937: permanently_set_uid(pw);
938: #endif
939: }
940: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
941: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
942: }
943:
1.131 markus 944: static void
1.130 provos 945: launch_login(struct passwd *pw, const char *hostname)
946: {
947: /* Launch login(1). */
948:
949: execl("/usr/bin/login", "login", "-h", hostname,
950: "-p", "-f", "--", pw->pw_name, (char *)NULL);
951:
952: /* Login couldn't be executed, die. */
953:
954: perror("login");
955: exit(1);
956: }
957:
1.127 markus 958: /*
959: * Performs common processing for the child, such as setting up the
960: * environment, closing extra file descriptors, setting the user and group
961: * ids, and executing the command or shell.
962: */
963: void
964: do_child(Session *s, const char *command)
965: {
966: extern char **environ;
967: char **env;
968: char *argv[10];
969: const char *shell, *shell0, *hostname = NULL;
970: struct passwd *pw = s->pw;
971: u_int i;
972:
973: /* remove hostkey from the child's memory */
974: destroy_sensitive_data();
975:
976: /* login(1) is only called if we execute the login shell */
977: if (options.use_login && command != NULL)
978: options.use_login = 0;
979:
980: /*
981: * Login(1) does this as well, and it needs uid 0 for the "-h"
982: * switch, so we let login(1) to this for us.
983: */
984: if (!options.use_login) {
985: do_nologin(pw);
986: do_setusercontext(pw);
987: }
988:
989: /*
990: * Get the shell from the password data. An empty shell field is
991: * legal, and means /bin/sh.
992: */
993: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
994: #ifdef HAVE_LOGIN_CAP
995: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
996: #endif
997:
998: env = do_setup_env(s, shell);
999:
1.26 millert 1000: /* we have to stash the hostname before we close our socket. */
1001: if (options.use_login)
1.70 stevesk 1002: hostname = get_remote_name_or_ip(utmp_len,
1.120 markus 1003: options.verify_reverse_mapping);
1.1 markus 1004: /*
1005: * Close the connection descriptors; note that this is the child, and
1006: * the server will still have the socket open, and it is important
1007: * that we do not shutdown it. Note that the descriptors cannot be
1008: * closed before building the environment, as we call
1009: * get_remote_ipaddr there.
1010: */
1011: if (packet_get_connection_in() == packet_get_connection_out())
1012: close(packet_get_connection_in());
1013: else {
1014: close(packet_get_connection_in());
1015: close(packet_get_connection_out());
1016: }
1017: /*
1018: * Close all descriptors related to channels. They will still remain
1019: * open in the parent.
1020: */
1021: /* XXX better use close-on-exec? -markus */
1022: channel_close_all();
1023:
1024: /*
1025: * Close any extra file descriptors. Note that there may still be
1026: * descriptors left by system functions. They will be closed later.
1027: */
1028: endpwent();
1029:
1030: /*
1031: * Close any extra open file descriptors so that we don\'t have them
1032: * hanging around in clients. Note that we want to do this after
1033: * initgroups, because at least on Solaris 2.3 it leaves file
1034: * descriptors open.
1035: */
1036: for (i = 3; i < 64; i++)
1037: close(i);
1038:
1039: /*
1.125 deraadt 1040: * Must take new environment into use so that .ssh/rc,
1041: * /etc/ssh/sshrc and xauth are run in the proper environment.
1.1 markus 1042: */
1043: environ = env;
1.102 markus 1044:
1045: #ifdef AFS
1046: /* Try to get AFS tokens for the local cell. */
1047: if (k_hasafs()) {
1048: char cell[64];
1.112 deraadt 1049:
1.102 markus 1050: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1051: krb_afslog(cell, 0);
1.112 deraadt 1052:
1.102 markus 1053: krb_afslog(0, 0);
1054: }
1055: #endif /* AFS */
1.104 markus 1056:
1057: /* Change current directory to the user\'s home directory. */
1058: if (chdir(pw->pw_dir) < 0) {
1059: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1060: pw->pw_dir, strerror(errno));
1061: #ifdef HAVE_LOGIN_CAP
1062: if (login_getcapbool(lc, "requirehome", 0))
1063: exit(1);
1064: #endif
1065: }
1.1 markus 1066:
1.127 markus 1067: if (!options.use_login)
1068: do_rc_files(s, shell);
1.67 markus 1069:
1070: /* restore SIGPIPE for child */
1071: signal(SIGPIPE, SIG_DFL);
1072:
1.127 markus 1073: if (options.use_login) {
1.130 provos 1074: launch_login(pw, hostname);
1075: /* NEVERREACHED */
1.127 markus 1076: }
1077:
1078: /* Get the last component of the shell name. */
1079: if ((shell0 = strrchr(shell, '/')) != NULL)
1080: shell0++;
1081: else
1082: shell0 = shell;
1083:
1.1 markus 1084: /*
1085: * If we have no command, execute the shell. In this case, the shell
1086: * name to be passed in argv[0] is preceded by '-' to indicate that
1087: * this is a login shell.
1088: */
1089: if (!command) {
1.127 markus 1090: char argv0[256];
1.1 markus 1091:
1.127 markus 1092: /* Start the shell. Set initial character to '-'. */
1093: argv0[0] = '-';
1.1 markus 1094:
1.127 markus 1095: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1.128 markus 1096: >= sizeof(argv0) - 1) {
1.127 markus 1097: errno = EINVAL;
1.1 markus 1098: perror(shell);
1099: exit(1);
1.127 markus 1100: }
1.1 markus 1101:
1.127 markus 1102: /* Execute the shell. */
1103: argv[0] = argv0;
1104: argv[1] = NULL;
1105: execve(shell, argv, env);
1106:
1107: /* Executing the shell failed. */
1108: perror(shell);
1109: exit(1);
1.1 markus 1110: }
1111: /*
1112: * Execute the command using the user's shell. This uses the -c
1113: * option to execute the command.
1114: */
1.127 markus 1115: argv[0] = (char *) shell0;
1.1 markus 1116: argv[1] = "-c";
1117: argv[2] = (char *) command;
1118: argv[3] = NULL;
1119: execve(shell, argv, env);
1120: perror(shell);
1121: exit(1);
1122: }
1123:
1124: Session *
1125: session_new(void)
1126: {
1127: int i;
1128: static int did_init = 0;
1129: if (!did_init) {
1130: debug("session_new: init");
1.112 deraadt 1131: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1132: sessions[i].used = 0;
1133: }
1134: did_init = 1;
1135: }
1.112 deraadt 1136: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1137: Session *s = &sessions[i];
1138: if (! s->used) {
1.68 djm 1139: memset(s, 0, sizeof(*s));
1.1 markus 1140: s->chanid = -1;
1141: s->ptyfd = -1;
1142: s->ttyfd = -1;
1143: s->used = 1;
1.85 markus 1144: s->self = i;
1.1 markus 1145: debug("session_new: session %d", i);
1146: return s;
1147: }
1148: }
1149: return NULL;
1150: }
1151:
1.94 itojun 1152: static void
1.1 markus 1153: session_dump(void)
1154: {
1155: int i;
1.112 deraadt 1156: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1157: Session *s = &sessions[i];
1158: debug("dump: used %d session %d %p channel %d pid %d",
1159: s->used,
1160: s->self,
1161: s,
1162: s->chanid,
1163: s->pid);
1164: }
1165: }
1166:
1.2 markus 1167: int
1.97 markus 1168: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1169: {
1170: Session *s = session_new();
1171: debug("session_open: channel %d", chanid);
1172: if (s == NULL) {
1173: error("no more sessions");
1174: return 0;
1175: }
1.97 markus 1176: s->authctxt = authctxt;
1177: s->pw = authctxt->pw;
1.7 markus 1178: if (s->pw == NULL)
1.54 stevesk 1179: fatal("no user for session %d", s->self);
1.2 markus 1180: debug("session_open: session %d: link with channel %d", s->self, chanid);
1181: s->chanid = chanid;
1182: return 1;
1183: }
1184:
1.130 provos 1185: Session *
1186: session_by_tty(char *tty)
1187: {
1188: int i;
1189: for (i = 0; i < MAX_SESSIONS; i++) {
1190: Session *s = &sessions[i];
1191: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
1192: debug("session_by_tty: session %d tty %s", i, tty);
1193: return s;
1194: }
1195: }
1196: debug("session_by_tty: unknown tty %.100s", tty);
1197: session_dump();
1198: return NULL;
1199: }
1200:
1.94 itojun 1201: static Session *
1.2 markus 1202: session_by_channel(int id)
1203: {
1204: int i;
1.112 deraadt 1205: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1206: Session *s = &sessions[i];
1207: if (s->used && s->chanid == id) {
1208: debug("session_by_channel: session %d channel %d", i, id);
1209: return s;
1210: }
1211: }
1212: debug("session_by_channel: unknown channel %d", id);
1213: session_dump();
1214: return NULL;
1215: }
1216:
1.94 itojun 1217: static Session *
1.2 markus 1218: session_by_pid(pid_t pid)
1219: {
1220: int i;
1221: debug("session_by_pid: pid %d", pid);
1.112 deraadt 1222: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1223: Session *s = &sessions[i];
1224: if (s->used && s->pid == pid)
1225: return s;
1226: }
1227: error("session_by_pid: unknown pid %d", pid);
1228: session_dump();
1229: return NULL;
1230: }
1231:
1.94 itojun 1232: static int
1.2 markus 1233: session_window_change_req(Session *s)
1234: {
1235: s->col = packet_get_int();
1236: s->row = packet_get_int();
1237: s->xpixel = packet_get_int();
1238: s->ypixel = packet_get_int();
1.116 markus 1239: packet_check_eom();
1.2 markus 1240: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1241: return 1;
1242: }
1243:
1.94 itojun 1244: static int
1.2 markus 1245: session_pty_req(Session *s)
1246: {
1.45 markus 1247: u_int len;
1.72 stevesk 1248: int n_bytes;
1.132 markus 1249:
1.86 markus 1250: if (no_pty_flag) {
1251: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1252: return 0;
1.86 markus 1253: }
1254: if (s->ttyfd != -1) {
1255: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1256: return 0;
1.86 markus 1257: }
1258:
1.2 markus 1259: s->term = packet_get_string(&len);
1.86 markus 1260:
1261: if (compat20) {
1262: s->col = packet_get_int();
1263: s->row = packet_get_int();
1264: } else {
1265: s->row = packet_get_int();
1266: s->col = packet_get_int();
1267: }
1.2 markus 1268: s->xpixel = packet_get_int();
1269: s->ypixel = packet_get_int();
1270:
1271: if (strcmp(s->term, "") == 0) {
1272: xfree(s->term);
1273: s->term = NULL;
1274: }
1.86 markus 1275:
1.2 markus 1276: /* Allocate a pty and open it. */
1.86 markus 1277: debug("Allocating pty.");
1.130 provos 1278: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1.86 markus 1279: if (s->term)
1280: xfree(s->term);
1.2 markus 1281: s->term = NULL;
1282: s->ptyfd = -1;
1283: s->ttyfd = -1;
1284: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1285: return 0;
1.2 markus 1286: }
1287: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1288:
1289: /* for SSH1 the tty modes length is not given */
1290: if (!compat20)
1291: n_bytes = packet_remaining();
1292: tty_parse_modes(s->ttyfd, &n_bytes);
1293:
1.2 markus 1294: /*
1295: * Add a cleanup function to clear the utmp entry and record logout
1296: * time in case we call fatal() (e.g., the connection gets closed).
1297: */
1.85 markus 1298: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.130 provos 1299: if (!use_privsep)
1300: pty_setowner(s->pw, s->tty);
1.86 markus 1301:
1302: /* Set window size from the packet. */
1.2 markus 1303: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1304:
1.116 markus 1305: packet_check_eom();
1.9 markus 1306: session_proctitle(s);
1.2 markus 1307: return 1;
1308: }
1309:
1.94 itojun 1310: static int
1.7 markus 1311: session_subsystem_req(Session *s)
1312: {
1.105 markus 1313: struct stat st;
1.45 markus 1314: u_int len;
1.7 markus 1315: int success = 0;
1.105 markus 1316: char *cmd, *subsys = packet_get_string(&len);
1.18 jakob 1317: int i;
1.7 markus 1318:
1.116 markus 1319: packet_check_eom();
1.121 stevesk 1320: log("subsystem request for %.100s", subsys);
1.18 jakob 1321:
1322: for (i = 0; i < options.num_subsystems; i++) {
1.105 markus 1323: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1324: cmd = options.subsystem_command[i];
1325: if (stat(cmd, &st) < 0) {
1326: error("subsystem: cannot stat %s: %s", cmd,
1327: strerror(errno));
1328: break;
1329: }
1330: debug("subsystem: exec() %s", cmd);
1.64 markus 1331: s->is_subsystem = 1;
1.105 markus 1332: do_exec(s, cmd);
1.18 jakob 1333: success = 1;
1.122 markus 1334: break;
1.18 jakob 1335: }
1336: }
1337:
1338: if (!success)
1.121 stevesk 1339: log("subsystem request for %.100s failed, subsystem not found",
1.105 markus 1340: subsys);
1.7 markus 1341:
1342: xfree(subsys);
1343: return success;
1344: }
1345:
1.94 itojun 1346: static int
1.7 markus 1347: session_x11_req(Session *s)
1348: {
1.81 markus 1349: int success;
1.7 markus 1350:
1351: s->single_connection = packet_get_char();
1352: s->auth_proto = packet_get_string(NULL);
1353: s->auth_data = packet_get_string(NULL);
1354: s->screen = packet_get_int();
1.116 markus 1355: packet_check_eom();
1.7 markus 1356:
1.81 markus 1357: success = session_setup_x11fwd(s);
1358: if (!success) {
1.7 markus 1359: xfree(s->auth_proto);
1360: xfree(s->auth_data);
1.84 markus 1361: s->auth_proto = NULL;
1362: s->auth_data = NULL;
1.7 markus 1363: }
1.81 markus 1364: return success;
1.7 markus 1365: }
1366:
1.94 itojun 1367: static int
1.19 markus 1368: session_shell_req(Session *s)
1369: {
1.116 markus 1370: packet_check_eom();
1.90 markus 1371: do_exec(s, NULL);
1.19 markus 1372: return 1;
1373: }
1374:
1.94 itojun 1375: static int
1.19 markus 1376: session_exec_req(Session *s)
1377: {
1.45 markus 1378: u_int len;
1.19 markus 1379: char *command = packet_get_string(&len);
1.116 markus 1380: packet_check_eom();
1.90 markus 1381: do_exec(s, command);
1.92 markus 1382: xfree(command);
1.19 markus 1383: return 1;
1384: }
1385:
1.94 itojun 1386: static int
1.43 markus 1387: session_auth_agent_req(Session *s)
1388: {
1389: static int called = 0;
1.116 markus 1390: packet_check_eom();
1.44 markus 1391: if (no_agent_forwarding_flag) {
1392: debug("session_auth_agent_req: no_agent_forwarding_flag");
1393: return 0;
1394: }
1.43 markus 1395: if (called) {
1396: return 0;
1397: } else {
1398: called = 1;
1399: return auth_input_request_forwarding(s->pw);
1400: }
1401: }
1402:
1.123 markus 1403: int
1404: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1405: {
1406: int success = 0;
1407: Session *s;
1408:
1.123 markus 1409: if ((s = session_by_channel(c->self)) == NULL) {
1410: log("session_input_channel_req: no session %d req %.100s",
1411: c->self, rtype);
1412: return 0;
1413: }
1414: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1415:
1416: /*
1.64 markus 1417: * a session is in LARVAL state until a shell, a command
1418: * or a subsystem is executed
1.2 markus 1419: */
1420: if (c->type == SSH_CHANNEL_LARVAL) {
1421: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1422: success = session_shell_req(s);
1.2 markus 1423: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1424: success = session_exec_req(s);
1.2 markus 1425: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1426: success = session_pty_req(s);
1.7 markus 1427: } else if (strcmp(rtype, "x11-req") == 0) {
1428: success = session_x11_req(s);
1.43 markus 1429: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1430: success = session_auth_agent_req(s);
1.7 markus 1431: } else if (strcmp(rtype, "subsystem") == 0) {
1432: success = session_subsystem_req(s);
1.2 markus 1433: }
1434: }
1435: if (strcmp(rtype, "window-change") == 0) {
1436: success = session_window_change_req(s);
1437: }
1.123 markus 1438: return success;
1.2 markus 1439: }
1440:
1441: void
1442: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1443: {
1444: if (!compat20)
1445: fatal("session_set_fds: called for proto != 2.0");
1446: /*
1447: * now that have a child and a pipe to the child,
1448: * we can activate our channel and register the fd's
1449: */
1450: if (s->chanid == -1)
1451: fatal("no channel for session %d", s->self);
1452: channel_set_fds(s->chanid,
1453: fdout, fdin, fderr,
1.42 markus 1454: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.126 markus 1455: 1,
1456: CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1457: }
1458:
1.85 markus 1459: /*
1460: * Function to perform pty cleanup. Also called if we get aborted abnormally
1461: * (e.g., due to a dropped connection).
1462: */
1.130 provos 1463: void
1464: session_pty_cleanup2(void *session)
1.1 markus 1465: {
1.85 markus 1466: Session *s = session;
1467:
1468: if (s == NULL) {
1469: error("session_pty_cleanup: no session");
1470: return;
1471: }
1472: if (s->ttyfd == -1)
1.1 markus 1473: return;
1474:
1.54 stevesk 1475: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1476:
1477: /* Record that the user has logged out. */
1.85 markus 1478: if (s->pid != 0)
1479: record_logout(s->pid, s->tty);
1.1 markus 1480:
1481: /* Release the pseudo-tty. */
1.130 provos 1482: if (getuid() == 0)
1483: pty_release(s->tty);
1.1 markus 1484:
1485: /*
1486: * Close the server side of the socket pairs. We must do this after
1487: * the pty cleanup, so that another process doesn't get this pty
1488: * while we're still cleaning up.
1489: */
1490: if (close(s->ptymaster) < 0)
1.130 provos 1491: error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
1.108 markus 1492:
1493: /* unlink pty from session */
1494: s->ttyfd = -1;
1.2 markus 1495: }
1496:
1.130 provos 1497: void
1498: session_pty_cleanup(void *session)
1499: {
1500: PRIVSEP(session_pty_cleanup2(session));
1501: }
1502:
1.94 itojun 1503: static void
1.2 markus 1504: session_exit_message(Session *s, int status)
1505: {
1506: Channel *c;
1.124 markus 1507:
1508: if ((c = channel_lookup(s->chanid)) == NULL)
1.85 markus 1509: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1510: s->self, s->chanid);
1511: debug("session_exit_message: session %d channel %d pid %d",
1512: s->self, s->chanid, s->pid);
1513:
1514: if (WIFEXITED(status)) {
1.124 markus 1515: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 1516: packet_put_int(WEXITSTATUS(status));
1517: packet_send();
1518: } else if (WIFSIGNALED(status)) {
1.124 markus 1519: channel_request_start(s->chanid, "exit-signal", 0);
1.2 markus 1520: packet_put_int(WTERMSIG(status));
1521: packet_put_char(WCOREDUMP(status));
1522: packet_put_cstring("");
1523: packet_put_cstring("");
1524: packet_send();
1525: } else {
1526: /* Some weird exit cause. Just exit. */
1527: packet_disconnect("wait returned status %04x.", status);
1528: }
1529:
1530: /* disconnect channel */
1531: debug("session_exit_message: release channel %d", s->chanid);
1532: channel_cancel_cleanup(s->chanid);
1.5 markus 1533: /*
1534: * emulate a write failure with 'chan_write_failed', nobody will be
1535: * interested in data we write.
1536: * Note that we must not call 'chan_read_failed', since there could
1537: * be some more data waiting in the pipe.
1538: */
1.8 markus 1539: if (c->ostate != CHAN_OUTPUT_CLOSED)
1540: chan_write_failed(c);
1.2 markus 1541: s->chanid = -1;
1542: }
1543:
1.130 provos 1544: void
1.85 markus 1545: session_close(Session *s)
1.2 markus 1546: {
1.85 markus 1547: debug("session_close: session %d pid %d", s->self, s->pid);
1548: if (s->ttyfd != -1) {
1549: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1550: session_pty_cleanup(s);
1551: }
1.2 markus 1552: if (s->term)
1553: xfree(s->term);
1554: if (s->display)
1555: xfree(s->display);
1.118 stevesk 1556: if (s->auth_display)
1557: xfree(s->auth_display);
1.2 markus 1558: if (s->auth_data)
1559: xfree(s->auth_data);
1560: if (s->auth_proto)
1561: xfree(s->auth_proto);
1562: s->used = 0;
1.9 markus 1563: session_proctitle(s);
1.2 markus 1564: }
1565:
1566: void
1567: session_close_by_pid(pid_t pid, int status)
1568: {
1569: Session *s = session_by_pid(pid);
1570: if (s == NULL) {
1.89 markus 1571: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1572: return;
1573: }
1574: if (s->chanid != -1)
1575: session_exit_message(s, status);
1576: session_close(s);
1.98 markus 1577: }
1578:
1.2 markus 1579: /*
1580: * this is called when a channel dies before
1581: * the session 'child' itself dies
1582: */
1583: void
1584: session_close_by_channel(int id, void *arg)
1585: {
1586: Session *s = session_by_channel(id);
1587: if (s == NULL) {
1.107 markus 1588: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 1589: return;
1590: }
1.107 markus 1591: debug("session_close_by_channel: channel %d child %d", id, s->pid);
1592: if (s->pid != 0) {
1593: debug("session_close_by_channel: channel %d: has child", id);
1.108 markus 1594: /*
1595: * delay detach of session, but release pty, since
1596: * the fd's to the child are already closed
1597: */
1598: if (s->ttyfd != -1) {
1599: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1600: session_pty_cleanup(s);
1601: }
1.107 markus 1602: return;
1603: }
1604: /* detach by removing callback */
1.2 markus 1605: channel_cancel_cleanup(s->chanid);
1606: s->chanid = -1;
1.106 markus 1607: session_close(s);
1608: }
1609:
1610: void
1.130 provos 1611: session_destroy_all(void (*closefunc)(Session *))
1.106 markus 1612: {
1613: int i;
1.112 deraadt 1614: for (i = 0; i < MAX_SESSIONS; i++) {
1.106 markus 1615: Session *s = &sessions[i];
1.130 provos 1616: if (s->used) {
1617: if (closefunc != NULL)
1618: closefunc(s);
1619: else
1620: session_close(s);
1621: }
1.2 markus 1622: }
1.9 markus 1623: }
1624:
1.94 itojun 1625: static char *
1.9 markus 1626: session_tty_list(void)
1627: {
1628: static char buf[1024];
1629: int i;
1630: buf[0] = '\0';
1.112 deraadt 1631: for (i = 0; i < MAX_SESSIONS; i++) {
1.9 markus 1632: Session *s = &sessions[i];
1633: if (s->used && s->ttyfd != -1) {
1634: if (buf[0] != '\0')
1635: strlcat(buf, ",", sizeof buf);
1636: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1637: }
1638: }
1639: if (buf[0] == '\0')
1640: strlcpy(buf, "notty", sizeof buf);
1641: return buf;
1642: }
1643:
1644: void
1645: session_proctitle(Session *s)
1646: {
1647: if (s->pw == NULL)
1648: error("no user for session %d", s->self);
1649: else
1650: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1651: }
1652:
1653: int
1654: session_setup_x11fwd(Session *s)
1655: {
1656: struct stat st;
1.109 stevesk 1657: char display[512], auth_display[512];
1658: char hostname[MAXHOSTNAMELEN];
1.81 markus 1659:
1660: if (no_x11_forwarding_flag) {
1661: packet_send_debug("X11 forwarding disabled in user configuration file.");
1662: return 0;
1663: }
1664: if (!options.x11_forwarding) {
1665: debug("X11 forwarding disabled in server configuration file.");
1666: return 0;
1667: }
1668: if (!options.xauth_location ||
1669: (stat(options.xauth_location, &st) == -1)) {
1670: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.91 markus 1671: return 0;
1672: }
1673: if (options.use_login) {
1674: packet_send_debug("X11 forwarding disabled; "
1675: "not compatible with UseLogin=yes.");
1.81 markus 1676: return 0;
1677: }
1.87 markus 1678: if (s->display != NULL) {
1.81 markus 1679: debug("X11 display already set.");
1680: return 0;
1681: }
1.109 stevesk 1682: s->display_number = x11_create_display_inet(options.x11_display_offset,
1.119 stevesk 1683: options.x11_use_localhost, s->single_connection);
1.109 stevesk 1684: if (s->display_number == -1) {
1.87 markus 1685: debug("x11_create_display_inet failed.");
1.81 markus 1686: return 0;
1687: }
1.109 stevesk 1688:
1689: /* Set up a suitable value for the DISPLAY variable. */
1690: if (gethostname(hostname, sizeof(hostname)) < 0)
1691: fatal("gethostname: %.100s", strerror(errno));
1692: /*
1693: * auth_display must be used as the displayname when the
1694: * authorization entry is added with xauth(1). This will be
1695: * different than the DISPLAY string for localhost displays.
1696: */
1.119 stevesk 1697: if (options.x11_use_localhost) {
1.109 stevesk 1698: snprintf(display, sizeof display, "localhost:%d.%d",
1699: s->display_number, s->screen);
1.118 stevesk 1700: snprintf(auth_display, sizeof auth_display, "unix:%d.%d",
1701: s->display_number, s->screen);
1.109 stevesk 1702: s->display = xstrdup(display);
1.118 stevesk 1703: s->auth_display = xstrdup(auth_display);
1.109 stevesk 1704: } else {
1705: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1706: s->display_number, s->screen);
1707: s->display = xstrdup(display);
1.118 stevesk 1708: s->auth_display = xstrdup(display);
1.109 stevesk 1709: }
1710:
1.81 markus 1711: return 1;
1.2 markus 1712: }
1713:
1.94 itojun 1714: static void
1.49 markus 1715: do_authenticated2(Authctxt *authctxt)
1.2 markus 1716: {
1.97 markus 1717: server_loop2(authctxt);
1.1 markus 1718: }
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