Annotation of src/usr.bin/ssh/session.c, Revision 1.74.2.6
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.
1.74.2.2 jason 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"
1.74.2.6! miod 36: RCSID("$OpenBSD: session.c,v 1.134 2002/03/29 18:59:31 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"
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"
1.74.2.6! miod 59: #include "monitor_wrap.h"
1.1 markus 60:
61: /* func */
62:
63: Session *session_new(void);
1.74.2.2 jason 64: void session_set_fds(Session *, int, int, int);
1.74.2.6! miod 65: void session_pty_cleanup(void *);
1.74.2.2 jason 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);
1.74.2.2 jason 74: int check_quietlogin(Session *, const char *);
1.1 markus 75:
1.74.2.2 jason 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. */
1.74.2.2 jason 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
1.74.2.6! miod 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);
121:
1.74.2.1 jason 122: /* remove agent socket */
123: if (auth_get_socket_name())
124: auth_sock_cleanup_proc(authctxt->pw);
1.74.2.2 jason 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
1.1 markus 133: }
134:
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: */
1.74.2.2 jason 141: static void
1.65 markus 142: do_authenticated1(Authctxt *authctxt)
1.1 markus 143: {
144: Session *s;
1.65 markus 145: char *command;
1.74.2.5 miod 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();
1.74.2.2 jason 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. */
1.74.2.5 miod 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();
1.74.2.5 miod 168: packet_check_eom();
1.1 markus 169: if (compression_level < 1 || compression_level > 9) {
170: packet_send_debug("Received illegal compression level %d.",
1.74.2.5 miod 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:
1.74.2.2 jason 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: }
1.74.2.5 miod 199: packet_check_eom();
1.74.2.2 jason 200: success = session_setup_x11fwd(s);
201: if (!success) {
202: xfree(s->auth_proto);
203: xfree(s->auth_data);
204: s->auth_proto = NULL;
205: s->auth_data = NULL;
206: }
1.1 markus 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;
1.74.2.5 miod 236:
1.74.2.2 jason 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);
1.74.2.5 miod 243: packet_check_eom();
244:
1.74.2.2 jason 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;
1.74.2.5 miod 251:
1.74.2.2 jason 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 */
1.74.2.5 miod 269:
1.74.2.2 jason 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);
1.74.2.5 miod 277: packet_check_eom();
278:
1.74.2.2 jason 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);
1.74.2.2 jason 294: do_exec(s, command);
295: xfree(command);
1.1 markus 296: } else {
1.74.2.2 jason 297: do_exec(s, NULL);
1.1 markus 298: }
1.74.2.5 miod 299: packet_check_eom();
1.74.2.2 jason 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) {
1.74.2.2 jason 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:
1.74.2.3 miod 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:
1.74.2.2 jason 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:
537: original_command = NULL;
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;
546: socklen_t fromlen;
547: struct sockaddr_storage from;
548: struct passwd * pw = s->pw;
549: pid_t pid = getpid();
550:
551: /*
552: * Get IP address of client. If the connection is not a socket, let
553: * the address be 0.0.0.0.
554: */
555: memset(&from, 0, sizeof(from));
556: if (packet_connection_is_on_socket()) {
557: fromlen = sizeof(from);
558: if (getpeername(packet_get_connection_in(),
1.74.2.5 miod 559: (struct sockaddr *) & from, &fromlen) < 0) {
1.24 markus 560: debug("getpeername: %.100s", strerror(errno));
561: fatal_cleanup();
562: }
563: }
1.25 markus 564:
1.24 markus 565: /* Record that there was a login on that tty from the remote host. */
1.74.2.6! miod 566: if (!use_privsep)
! 567: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
! 568: get_remote_name_or_ip(utmp_len,
! 569: options.verify_reverse_mapping),
! 570: (struct sockaddr *)&from);
1.24 markus 571:
1.73 djm 572: if (check_quietlogin(s, command))
1.24 markus 573: return;
1.73 djm 574:
1.74.2.6! miod 575: if (options.print_lastlog && s->last_login_time != 0) {
! 576: time_string = ctime(&s->last_login_time);
1.24 markus 577: if (strchr(time_string, '\n'))
578: *strchr(time_string, '\n') = 0;
1.74.2.6! miod 579: if (strcmp(s->hostname, "") == 0)
1.24 markus 580: printf("Last login: %s\r\n", time_string);
581: else
1.74.2.6! miod 582: printf("Last login: %s from %s\r\n", time_string,
! 583: s->hostname);
1.24 markus 584: }
1.73 djm 585:
586: do_motd();
587: }
588:
589: /*
590: * Display the message of the day.
591: */
592: void
593: do_motd(void)
594: {
595: FILE *f;
596: char buf[256];
597:
1.24 markus 598: if (options.print_motd) {
1.28 millert 599: #ifdef HAVE_LOGIN_CAP
600: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
601: "/etc/motd"), "r");
602: #else
1.24 markus 603: f = fopen("/etc/motd", "r");
1.28 millert 604: #endif
1.24 markus 605: if (f) {
606: while (fgets(buf, sizeof(buf), f))
607: fputs(buf, stdout);
608: fclose(f);
609: }
1.2 markus 610: }
1.73 djm 611: }
612:
613:
614: /*
615: * Check for quiet login, either .hushlogin or command given.
616: */
617: int
618: check_quietlogin(Session *s, const char *command)
619: {
620: char buf[256];
1.74.2.2 jason 621: struct passwd *pw = s->pw;
1.73 djm 622: struct stat st;
623:
624: /* Return 1 if .hushlogin exists or a command given. */
625: if (command != NULL)
626: return 1;
627: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
628: #ifdef HAVE_LOGIN_CAP
629: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
630: return 1;
631: #else
632: if (stat(buf, &st) >= 0)
633: return 1;
634: #endif
635: return 0;
1.1 markus 636: }
637:
638: /*
639: * Sets the value of the given variable in the environment. If the variable
640: * already exists, its value is overriden.
641: */
1.74.2.2 jason 642: static void
1.45 markus 643: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.74.2.5 miod 644: const char *value)
1.1 markus 645: {
1.45 markus 646: u_int i, namelen;
1.1 markus 647: char **env;
648:
649: /*
650: * Find the slot where the value should be stored. If the variable
651: * already exists, we reuse the slot; otherwise we append a new slot
652: * at the end of the array, expanding if necessary.
653: */
654: env = *envp;
655: namelen = strlen(name);
656: for (i = 0; env[i]; i++)
657: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
658: break;
659: if (env[i]) {
660: /* Reuse the slot. */
661: xfree(env[i]);
662: } else {
663: /* New variable. Expand if necessary. */
664: if (i >= (*envsizep) - 1) {
665: (*envsizep) += 50;
666: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
667: }
668: /* Need to set the NULL pointer at end of array beyond the new slot. */
669: env[i + 1] = NULL;
670: }
671:
672: /* Allocate space and format the variable in the appropriate slot. */
673: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
674: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
675: }
676:
677: /*
678: * Reads environment variables from the given file and adds/overrides them
679: * into the environment. If the file does not exist, this does nothing.
680: * Otherwise, it must consist of empty lines, comments (line starts with '#')
681: * and assignments of the form name=value. No other forms are allowed.
682: */
1.74.2.2 jason 683: static void
1.45 markus 684: read_environment_file(char ***env, u_int *envsize,
1.74.2.5 miod 685: const char *filename)
1.1 markus 686: {
687: FILE *f;
688: char buf[4096];
689: char *cp, *value;
690:
691: f = fopen(filename, "r");
692: if (!f)
693: return;
694:
695: while (fgets(buf, sizeof(buf), f)) {
696: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
697: ;
698: if (!*cp || *cp == '#' || *cp == '\n')
699: continue;
700: if (strchr(cp, '\n'))
701: *strchr(cp, '\n') = '\0';
702: value = strchr(cp, '=');
703: if (value == NULL) {
704: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
705: continue;
706: }
1.14 deraadt 707: /*
708: * Replace the equals sign by nul, and advance value to
709: * the value string.
710: */
1.1 markus 711: *value = '\0';
712: value++;
713: child_set_env(env, envsize, cp, value);
714: }
715: fclose(f);
716: }
717:
1.74.2.5 miod 718: static char **
719: do_setup_env(Session *s, const char *shell)
1.1 markus 720: {
721: char buf[256];
1.74.2.5 miod 722: u_int i, envsize;
1.1 markus 723: char **env;
1.74.2.5 miod 724: struct passwd *pw = s->pw;
1.1 markus 725:
726: /* Initialize the environment. */
727: envsize = 100;
728: env = xmalloc(envsize * sizeof(char *));
729: env[0] = NULL;
730:
731: if (!options.use_login) {
732: /* Set basic environment. */
733: child_set_env(&env, &envsize, "USER", pw->pw_name);
734: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
735: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 736: #ifdef HAVE_LOGIN_CAP
1.29 millert 737: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
738: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 739: #else
1.29 millert 740: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 741: #endif
1.1 markus 742:
743: snprintf(buf, sizeof buf, "%.200s/%.50s",
744: _PATH_MAILDIR, pw->pw_name);
745: child_set_env(&env, &envsize, "MAIL", buf);
746:
747: /* Normal systems set SHELL by default. */
748: child_set_env(&env, &envsize, "SHELL", shell);
749: }
750: if (getenv("TZ"))
751: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
752:
753: /* Set custom environment options from RSA authentication. */
1.74.2.4 miod 754: if (!options.use_login) {
755: while (custom_environment) {
756: struct envstring *ce = custom_environment;
757: char *s = ce->s;
1.74.2.5 miod 758:
1.74.2.4 miod 759: for (i = 0; s[i] != '=' && s[i]; i++)
760: ;
761: if (s[i] == '=') {
762: s[i] = 0;
763: child_set_env(&env, &envsize, s, s + i + 1);
764: }
765: custom_environment = ce->next;
766: xfree(ce->s);
767: xfree(ce);
1.1 markus 768: }
769: }
770:
771: snprintf(buf, sizeof buf, "%.50s %d %d",
1.74.2.5 miod 772: get_remote_ipaddr(), get_remote_port(), get_local_port());
1.1 markus 773: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
774:
1.60 markus 775: if (s->ttyfd != -1)
776: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
777: if (s->term)
778: child_set_env(&env, &envsize, "TERM", s->term);
779: if (s->display)
780: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 781: if (original_command)
782: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
783: original_command);
1.1 markus 784: #ifdef KRB4
1.74.2.2 jason 785: if (s->authctxt->krb4_ticket_file)
786: child_set_env(&env, &envsize, "KRBTKFILE",
1.74.2.5 miod 787: s->authctxt->krb4_ticket_file);
1.74.2.2 jason 788: #endif
789: #ifdef KRB5
790: if (s->authctxt->krb5_ticket_file)
791: child_set_env(&env, &envsize, "KRB5CCNAME",
1.74.2.5 miod 792: s->authctxt->krb5_ticket_file);
1.74.2.2 jason 793: #endif
1.1 markus 794: if (auth_get_socket_name() != NULL)
795: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.74.2.5 miod 796: auth_get_socket_name());
1.1 markus 797:
798: /* read $HOME/.ssh/environment. */
799: if (!options.use_login) {
1.14 deraadt 800: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
801: pw->pw_dir);
1.1 markus 802: read_environment_file(&env, &envsize, buf);
803: }
804: if (debug_flag) {
805: /* dump the environment */
806: fprintf(stderr, "Environment:\n");
807: for (i = 0; env[i]; i++)
808: fprintf(stderr, " %.200s\n", env[i]);
809: }
1.74.2.5 miod 810: return env;
811: }
812:
813: /*
814: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found
815: * first in this order).
816: */
817: static void
818: do_rc_files(Session *s, const char *shell)
819: {
820: FILE *f = NULL;
821: char cmd[1024];
822: int do_xauth;
823: struct stat st;
824:
825: do_xauth =
826: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
827:
828: /* ignore _PATH_SSH_USER_RC for subsystems */
829: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
830: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
831: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
832: if (debug_flag)
833: fprintf(stderr, "Running %s\n", cmd);
834: f = popen(cmd, "w");
835: if (f) {
836: if (do_xauth)
837: fprintf(f, "%s %s\n", s->auth_proto,
838: s->auth_data);
839: pclose(f);
840: } else
841: fprintf(stderr, "Could not run %s\n",
842: _PATH_SSH_USER_RC);
843: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
844: if (debug_flag)
845: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
846: _PATH_SSH_SYSTEM_RC);
847: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
848: if (f) {
849: if (do_xauth)
850: fprintf(f, "%s %s\n", s->auth_proto,
851: s->auth_data);
852: pclose(f);
853: } else
854: fprintf(stderr, "Could not run %s\n",
855: _PATH_SSH_SYSTEM_RC);
856: } else if (do_xauth && options.xauth_location != NULL) {
857: /* Add authority data to .Xauthority if appropriate. */
858: if (debug_flag) {
859: fprintf(stderr,
860: "Running %.100s add "
861: "%.100s %.100s %.100s\n",
862: options.xauth_location, s->auth_display,
863: s->auth_proto, s->auth_data);
864: }
865: snprintf(cmd, sizeof cmd, "%s -q -",
866: options.xauth_location);
867: f = popen(cmd, "w");
868: if (f) {
869: fprintf(f, "add %s %s %s\n",
870: s->auth_display, s->auth_proto,
871: s->auth_data);
872: pclose(f);
873: } else {
874: fprintf(stderr, "Could not run %s\n",
875: cmd);
876: }
877: }
878: }
879:
880: static void
881: do_nologin(struct passwd *pw)
882: {
883: FILE *f = NULL;
884: char buf[1024];
885:
886: #ifdef HAVE_LOGIN_CAP
887: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
888: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
889: _PATH_NOLOGIN), "r");
890: #else
891: if (pw->pw_uid)
892: f = fopen(_PATH_NOLOGIN, "r");
893: #endif
894: if (f) {
895: /* /etc/nologin exists. Print its contents and exit. */
896: while (fgets(buf, sizeof(buf), f))
897: fputs(buf, stderr);
898: fclose(f);
899: exit(254);
900: }
901: }
902:
903: /* Set login name, uid, gid, and groups. */
1.74.2.6! miod 904: void
1.74.2.5 miod 905: do_setusercontext(struct passwd *pw)
906: {
907: if (getuid() == 0 || geteuid() == 0) {
908: #ifdef HAVE_LOGIN_CAP
909: if (setusercontext(lc, pw, pw->pw_uid,
910: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
911: perror("unable to set user context");
912: exit(1);
913: }
914: #else
915: if (setlogin(pw->pw_name) < 0)
916: error("setlogin failed: %s", strerror(errno));
917: if (setgid(pw->pw_gid) < 0) {
918: perror("setgid");
919: exit(1);
920: }
921: /* Initialize the group list. */
922: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
923: perror("initgroups");
924: exit(1);
925: }
926: endgrent();
927:
928: /* Permanently switch to the desired uid. */
929: permanently_set_uid(pw);
930: #endif
931: }
932: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
933: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
934: }
935:
1.74.2.6! miod 936: static void
! 937: launch_login(struct passwd *pw, const char *hostname)
! 938: {
! 939: /* Launch login(1). */
! 940:
! 941: execl("/usr/bin/login", "login", "-h", hostname,
! 942: "-p", "-f", "--", pw->pw_name, (char *)NULL);
! 943:
! 944: /* Login couldn't be executed, die. */
! 945:
! 946: perror("login");
! 947: exit(1);
! 948: }
! 949:
1.74.2.5 miod 950: /*
951: * Performs common processing for the child, such as setting up the
952: * environment, closing extra file descriptors, setting the user and group
953: * ids, and executing the command or shell.
954: */
955: void
956: do_child(Session *s, const char *command)
957: {
958: extern char **environ;
959: char **env;
960: char *argv[10];
961: const char *shell, *shell0, *hostname = NULL;
962: struct passwd *pw = s->pw;
963: u_int i;
964:
965: /* remove hostkey from the child's memory */
966: destroy_sensitive_data();
967:
968: /* login(1) is only called if we execute the login shell */
969: if (options.use_login && command != NULL)
970: options.use_login = 0;
971:
972: /*
973: * Login(1) does this as well, and it needs uid 0 for the "-h"
974: * switch, so we let login(1) to this for us.
975: */
976: if (!options.use_login) {
977: do_nologin(pw);
978: do_setusercontext(pw);
979: }
980:
981: /*
982: * Get the shell from the password data. An empty shell field is
983: * legal, and means /bin/sh.
984: */
985: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
986: #ifdef HAVE_LOGIN_CAP
987: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
988: #endif
989:
990: env = do_setup_env(s, shell);
991:
1.26 millert 992: /* we have to stash the hostname before we close our socket. */
993: if (options.use_login)
1.70 stevesk 994: hostname = get_remote_name_or_ip(utmp_len,
1.74.2.5 miod 995: options.verify_reverse_mapping);
1.1 markus 996: /*
997: * Close the connection descriptors; note that this is the child, and
998: * the server will still have the socket open, and it is important
999: * that we do not shutdown it. Note that the descriptors cannot be
1000: * closed before building the environment, as we call
1001: * get_remote_ipaddr there.
1002: */
1003: if (packet_get_connection_in() == packet_get_connection_out())
1004: close(packet_get_connection_in());
1005: else {
1006: close(packet_get_connection_in());
1007: close(packet_get_connection_out());
1008: }
1009: /*
1010: * Close all descriptors related to channels. They will still remain
1011: * open in the parent.
1012: */
1013: /* XXX better use close-on-exec? -markus */
1014: channel_close_all();
1015:
1016: /*
1017: * Close any extra file descriptors. Note that there may still be
1018: * descriptors left by system functions. They will be closed later.
1019: */
1020: endpwent();
1021:
1022: /*
1023: * Close any extra open file descriptors so that we don\'t have them
1024: * hanging around in clients. Note that we want to do this after
1025: * initgroups, because at least on Solaris 2.3 it leaves file
1026: * descriptors open.
1027: */
1028: for (i = 3; i < 64; i++)
1029: close(i);
1030:
1031: /*
1.74.2.5 miod 1032: * Must take new environment into use so that .ssh/rc,
1033: * /etc/sshrc and xauth are run in the proper environment.
1.1 markus 1034: */
1035: environ = env;
1036:
1.74.2.2 jason 1037: #ifdef AFS
1038: /* Try to get AFS tokens for the local cell. */
1039: if (k_hasafs()) {
1040: char cell[64];
1.74.2.5 miod 1041:
1.74.2.2 jason 1042: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1043: krb_afslog(cell, 0);
1.74.2.5 miod 1044:
1.74.2.2 jason 1045: krb_afslog(0, 0);
1046: }
1047: #endif /* AFS */
1048:
1.74.2.3 miod 1049: /* Change current directory to the user\'s home directory. */
1050: if (chdir(pw->pw_dir) < 0) {
1051: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1052: pw->pw_dir, strerror(errno));
1053: #ifdef HAVE_LOGIN_CAP
1054: if (login_getcapbool(lc, "requirehome", 0))
1055: exit(1);
1056: #endif
1057: }
1058:
1.74.2.5 miod 1059: if (!options.use_login)
1060: do_rc_files(s, shell);
1.67 markus 1061:
1062: /* restore SIGPIPE for child */
1063: signal(SIGPIPE, SIG_DFL);
1064:
1.74.2.5 miod 1065: if (options.use_login) {
1.74.2.6! miod 1066: launch_login(pw, hostname);
! 1067: /* NEVERREACHED */
1.74.2.5 miod 1068: }
1069:
1070: /* Get the last component of the shell name. */
1071: if ((shell0 = strrchr(shell, '/')) != NULL)
1072: shell0++;
1073: else
1074: shell0 = shell;
1075:
1.1 markus 1076: /*
1077: * If we have no command, execute the shell. In this case, the shell
1078: * name to be passed in argv[0] is preceded by '-' to indicate that
1079: * this is a login shell.
1080: */
1081: if (!command) {
1.74.2.5 miod 1082: char argv0[256];
1.1 markus 1083:
1.74.2.5 miod 1084: /* Start the shell. Set initial character to '-'. */
1085: argv0[0] = '-';
1.1 markus 1086:
1.74.2.5 miod 1087: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
1088: >= sizeof(argv0) - 1) {
1089: errno = EINVAL;
1.1 markus 1090: perror(shell);
1091: exit(1);
1092: }
1.74.2.5 miod 1093:
1094: /* Execute the shell. */
1095: argv[0] = argv0;
1096: argv[1] = NULL;
1097: execve(shell, argv, env);
1098:
1099: /* Executing the shell failed. */
1100: perror(shell);
1101: exit(1);
1.1 markus 1102: }
1103: /*
1104: * Execute the command using the user's shell. This uses the -c
1105: * option to execute the command.
1106: */
1.74.2.5 miod 1107: argv[0] = (char *) shell0;
1.1 markus 1108: argv[1] = "-c";
1109: argv[2] = (char *) command;
1110: argv[3] = NULL;
1111: execve(shell, argv, env);
1112: perror(shell);
1113: exit(1);
1114: }
1115:
1116: Session *
1117: session_new(void)
1118: {
1119: int i;
1120: static int did_init = 0;
1121: if (!did_init) {
1122: debug("session_new: init");
1.74.2.5 miod 1123: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1124: sessions[i].used = 0;
1125: }
1126: did_init = 1;
1127: }
1.74.2.5 miod 1128: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1129: Session *s = &sessions[i];
1130: if (! s->used) {
1.68 djm 1131: memset(s, 0, sizeof(*s));
1.1 markus 1132: s->chanid = -1;
1133: s->ptyfd = -1;
1134: s->ttyfd = -1;
1135: s->used = 1;
1.74.2.2 jason 1136: s->self = i;
1.1 markus 1137: debug("session_new: session %d", i);
1138: return s;
1139: }
1140: }
1141: return NULL;
1142: }
1143:
1.74.2.2 jason 1144: static void
1.1 markus 1145: session_dump(void)
1146: {
1147: int i;
1.74.2.5 miod 1148: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1149: Session *s = &sessions[i];
1150: debug("dump: used %d session %d %p channel %d pid %d",
1151: s->used,
1152: s->self,
1153: s,
1154: s->chanid,
1155: s->pid);
1156: }
1157: }
1158:
1.2 markus 1159: int
1.74.2.2 jason 1160: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1161: {
1162: Session *s = session_new();
1163: debug("session_open: channel %d", chanid);
1164: if (s == NULL) {
1165: error("no more sessions");
1166: return 0;
1167: }
1.74.2.2 jason 1168: s->authctxt = authctxt;
1169: s->pw = authctxt->pw;
1.7 markus 1170: if (s->pw == NULL)
1.54 stevesk 1171: fatal("no user for session %d", s->self);
1.2 markus 1172: debug("session_open: session %d: link with channel %d", s->self, chanid);
1173: s->chanid = chanid;
1174: return 1;
1175: }
1176:
1.74.2.6! miod 1177: Session *
! 1178: session_by_tty(char *tty)
! 1179: {
! 1180: int i;
! 1181: for (i = 0; i < MAX_SESSIONS; i++) {
! 1182: Session *s = &sessions[i];
! 1183: if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
! 1184: debug("session_by_tty: session %d tty %s", i, tty);
! 1185: return s;
! 1186: }
! 1187: }
! 1188: debug("session_by_tty: unknown tty %.100s", tty);
! 1189: session_dump();
! 1190: return NULL;
! 1191: }
! 1192:
1.74.2.2 jason 1193: static Session *
1.2 markus 1194: session_by_channel(int id)
1195: {
1196: int i;
1.74.2.5 miod 1197: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1198: Session *s = &sessions[i];
1199: if (s->used && s->chanid == id) {
1200: debug("session_by_channel: session %d channel %d", i, id);
1201: return s;
1202: }
1203: }
1204: debug("session_by_channel: unknown channel %d", id);
1205: session_dump();
1206: return NULL;
1207: }
1208:
1.74.2.2 jason 1209: static Session *
1.2 markus 1210: session_by_pid(pid_t pid)
1211: {
1212: int i;
1213: debug("session_by_pid: pid %d", pid);
1.74.2.5 miod 1214: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1215: Session *s = &sessions[i];
1216: if (s->used && s->pid == pid)
1217: return s;
1218: }
1219: error("session_by_pid: unknown pid %d", pid);
1220: session_dump();
1221: return NULL;
1222: }
1223:
1.74.2.2 jason 1224: static int
1.2 markus 1225: session_window_change_req(Session *s)
1226: {
1227: s->col = packet_get_int();
1228: s->row = packet_get_int();
1229: s->xpixel = packet_get_int();
1230: s->ypixel = packet_get_int();
1.74.2.5 miod 1231: packet_check_eom();
1.2 markus 1232: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1233: return 1;
1234: }
1235:
1.74.2.2 jason 1236: static int
1.2 markus 1237: session_pty_req(Session *s)
1238: {
1.45 markus 1239: u_int len;
1.72 stevesk 1240: int n_bytes;
1.2 markus 1241:
1.74.2.2 jason 1242: if (no_pty_flag) {
1243: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1244: return 0;
1.74.2.2 jason 1245: }
1246: if (s->ttyfd != -1) {
1247: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1248: return 0;
1.74.2.2 jason 1249: }
1.74.2.6! miod 1250: /* Get the time and hostname when the user last logged in. */
! 1251: if (options.print_lastlog) {
! 1252: s->hostname[0] = '\0';
! 1253: s->last_login_time = get_last_login_time(s->pw->pw_uid,
! 1254: s->pw->pw_name, s->hostname, sizeof(s->hostname));
! 1255: }
1.74.2.2 jason 1256:
1.2 markus 1257: s->term = packet_get_string(&len);
1.74.2.2 jason 1258:
1259: if (compat20) {
1260: s->col = packet_get_int();
1261: s->row = packet_get_int();
1262: } else {
1263: s->row = packet_get_int();
1264: s->col = packet_get_int();
1265: }
1.2 markus 1266: s->xpixel = packet_get_int();
1267: s->ypixel = packet_get_int();
1268:
1269: if (strcmp(s->term, "") == 0) {
1270: xfree(s->term);
1271: s->term = NULL;
1272: }
1.74.2.2 jason 1273:
1.2 markus 1274: /* Allocate a pty and open it. */
1.74.2.2 jason 1275: debug("Allocating pty.");
1.74.2.6! miod 1276: if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) {
1.74.2.2 jason 1277: if (s->term)
1278: xfree(s->term);
1.2 markus 1279: s->term = NULL;
1280: s->ptyfd = -1;
1281: s->ttyfd = -1;
1282: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1283: return 0;
1.2 markus 1284: }
1285: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.74.2.2 jason 1286:
1287: /* for SSH1 the tty modes length is not given */
1288: if (!compat20)
1289: n_bytes = packet_remaining();
1290: tty_parse_modes(s->ttyfd, &n_bytes);
1291:
1.2 markus 1292: /*
1293: * Add a cleanup function to clear the utmp entry and record logout
1294: * time in case we call fatal() (e.g., the connection gets closed).
1295: */
1.74.2.2 jason 1296: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.74.2.6! miod 1297: if (!use_privsep)
! 1298: pty_setowner(s->pw, s->tty);
1.74.2.2 jason 1299:
1300: /* Set window size from the packet. */
1.2 markus 1301: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1302:
1.74.2.5 miod 1303: packet_check_eom();
1.9 markus 1304: session_proctitle(s);
1.2 markus 1305: return 1;
1306: }
1307:
1.74.2.2 jason 1308: static int
1.7 markus 1309: session_subsystem_req(Session *s)
1310: {
1.74.2.3 miod 1311: struct stat st;
1.45 markus 1312: u_int len;
1.7 markus 1313: int success = 0;
1.74.2.3 miod 1314: char *cmd, *subsys = packet_get_string(&len);
1.18 jakob 1315: int i;
1.7 markus 1316:
1.74.2.5 miod 1317: packet_check_eom();
1318: log("subsystem request for %.100s", subsys);
1.18 jakob 1319:
1320: for (i = 0; i < options.num_subsystems; i++) {
1.74.2.3 miod 1321: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1322: cmd = options.subsystem_command[i];
1323: if (stat(cmd, &st) < 0) {
1324: error("subsystem: cannot stat %s: %s", cmd,
1325: strerror(errno));
1326: break;
1327: }
1328: debug("subsystem: exec() %s", cmd);
1.64 markus 1329: s->is_subsystem = 1;
1.74.2.3 miod 1330: do_exec(s, cmd);
1.18 jakob 1331: success = 1;
1.74.2.5 miod 1332: break;
1.18 jakob 1333: }
1334: }
1335:
1336: if (!success)
1.74.2.5 miod 1337: log("subsystem request for %.100s failed, subsystem not found",
1.74.2.3 miod 1338: subsys);
1.7 markus 1339:
1340: xfree(subsys);
1341: return success;
1342: }
1343:
1.74.2.2 jason 1344: static int
1.7 markus 1345: session_x11_req(Session *s)
1346: {
1.74.2.2 jason 1347: int success;
1.7 markus 1348:
1349: s->single_connection = packet_get_char();
1350: s->auth_proto = packet_get_string(NULL);
1351: s->auth_data = packet_get_string(NULL);
1352: s->screen = packet_get_int();
1.74.2.5 miod 1353: packet_check_eom();
1.7 markus 1354:
1.74.2.2 jason 1355: success = session_setup_x11fwd(s);
1356: if (!success) {
1.7 markus 1357: xfree(s->auth_proto);
1358: xfree(s->auth_data);
1.74.2.2 jason 1359: s->auth_proto = NULL;
1360: s->auth_data = NULL;
1.7 markus 1361: }
1.74.2.2 jason 1362: return success;
1.7 markus 1363: }
1364:
1.74.2.2 jason 1365: static int
1.19 markus 1366: session_shell_req(Session *s)
1367: {
1.74.2.5 miod 1368: packet_check_eom();
1.74.2.2 jason 1369: do_exec(s, NULL);
1.19 markus 1370: return 1;
1371: }
1372:
1.74.2.2 jason 1373: static int
1.19 markus 1374: session_exec_req(Session *s)
1375: {
1.45 markus 1376: u_int len;
1.19 markus 1377: char *command = packet_get_string(&len);
1.74.2.5 miod 1378: packet_check_eom();
1.74.2.2 jason 1379: do_exec(s, command);
1380: xfree(command);
1.19 markus 1381: return 1;
1382: }
1383:
1.74.2.2 jason 1384: static int
1.43 markus 1385: session_auth_agent_req(Session *s)
1386: {
1387: static int called = 0;
1.74.2.5 miod 1388: packet_check_eom();
1.44 markus 1389: if (no_agent_forwarding_flag) {
1390: debug("session_auth_agent_req: no_agent_forwarding_flag");
1391: return 0;
1392: }
1.43 markus 1393: if (called) {
1394: return 0;
1395: } else {
1396: called = 1;
1397: return auth_input_request_forwarding(s->pw);
1398: }
1399: }
1400:
1.74.2.5 miod 1401: int
1402: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1403: {
1404: int success = 0;
1405: Session *s;
1406:
1.74.2.5 miod 1407: if ((s = session_by_channel(c->self)) == NULL) {
1408: log("session_input_channel_req: no session %d req %.100s",
1409: c->self, rtype);
1410: return 0;
1411: }
1412: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1413:
1414: /*
1.64 markus 1415: * a session is in LARVAL state until a shell, a command
1416: * or a subsystem is executed
1.2 markus 1417: */
1418: if (c->type == SSH_CHANNEL_LARVAL) {
1419: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1420: success = session_shell_req(s);
1.2 markus 1421: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1422: success = session_exec_req(s);
1.2 markus 1423: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1424: success = session_pty_req(s);
1.7 markus 1425: } else if (strcmp(rtype, "x11-req") == 0) {
1426: success = session_x11_req(s);
1.43 markus 1427: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1428: success = session_auth_agent_req(s);
1.7 markus 1429: } else if (strcmp(rtype, "subsystem") == 0) {
1430: success = session_subsystem_req(s);
1.2 markus 1431: }
1432: }
1433: if (strcmp(rtype, "window-change") == 0) {
1434: success = session_window_change_req(s);
1435: }
1.74.2.5 miod 1436: return success;
1.2 markus 1437: }
1438:
1439: void
1440: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1441: {
1442: if (!compat20)
1443: fatal("session_set_fds: called for proto != 2.0");
1444: /*
1445: * now that have a child and a pipe to the child,
1446: * we can activate our channel and register the fd's
1447: */
1448: if (s->chanid == -1)
1449: fatal("no channel for session %d", s->self);
1450: channel_set_fds(s->chanid,
1451: fdout, fdin, fderr,
1.42 markus 1452: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.74.2.5 miod 1453: 1,
1454: CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1455: }
1456:
1.74.2.2 jason 1457: /*
1458: * Function to perform pty cleanup. Also called if we get aborted abnormally
1459: * (e.g., due to a dropped connection).
1460: */
1.74.2.6! miod 1461: void
! 1462: session_pty_cleanup2(void *session)
1.1 markus 1463: {
1.74.2.2 jason 1464: Session *s = session;
1465:
1466: if (s == NULL) {
1467: error("session_pty_cleanup: no session");
1468: return;
1469: }
1470: if (s->ttyfd == -1)
1.1 markus 1471: return;
1472:
1.54 stevesk 1473: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1474:
1475: /* Record that the user has logged out. */
1.74.2.2 jason 1476: if (s->pid != 0)
1477: record_logout(s->pid, s->tty);
1.1 markus 1478:
1479: /* Release the pseudo-tty. */
1.74.2.6! miod 1480: if (getuid() == 0)
! 1481: pty_release(s->tty);
1.1 markus 1482:
1483: /*
1484: * Close the server side of the socket pairs. We must do this after
1485: * the pty cleanup, so that another process doesn't get this pty
1486: * while we're still cleaning up.
1487: */
1488: if (close(s->ptymaster) < 0)
1.74.2.6! miod 1489: error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno));
1.74.2.3 miod 1490:
1491: /* unlink pty from session */
1492: s->ttyfd = -1;
1.2 markus 1493: }
1494:
1.74.2.6! miod 1495: void
! 1496: session_pty_cleanup(void *session)
! 1497: {
! 1498: PRIVSEP(session_pty_cleanup2(session));
! 1499: }
! 1500:
1.74.2.2 jason 1501: static void
1.2 markus 1502: session_exit_message(Session *s, int status)
1503: {
1504: Channel *c;
1.74.2.5 miod 1505:
1506: if ((c = channel_lookup(s->chanid)) == NULL)
1.74.2.2 jason 1507: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1508: s->self, s->chanid);
1509: debug("session_exit_message: session %d channel %d pid %d",
1510: s->self, s->chanid, s->pid);
1511:
1512: if (WIFEXITED(status)) {
1.74.2.5 miod 1513: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 1514: packet_put_int(WEXITSTATUS(status));
1515: packet_send();
1516: } else if (WIFSIGNALED(status)) {
1.74.2.5 miod 1517: channel_request_start(s->chanid, "exit-signal", 0);
1.2 markus 1518: packet_put_int(WTERMSIG(status));
1519: packet_put_char(WCOREDUMP(status));
1520: packet_put_cstring("");
1521: packet_put_cstring("");
1522: packet_send();
1523: } else {
1524: /* Some weird exit cause. Just exit. */
1525: packet_disconnect("wait returned status %04x.", status);
1526: }
1527:
1528: /* disconnect channel */
1529: debug("session_exit_message: release channel %d", s->chanid);
1530: channel_cancel_cleanup(s->chanid);
1.5 markus 1531: /*
1532: * emulate a write failure with 'chan_write_failed', nobody will be
1533: * interested in data we write.
1534: * Note that we must not call 'chan_read_failed', since there could
1535: * be some more data waiting in the pipe.
1536: */
1.8 markus 1537: if (c->ostate != CHAN_OUTPUT_CLOSED)
1538: chan_write_failed(c);
1.2 markus 1539: s->chanid = -1;
1540: }
1541:
1.74.2.6! miod 1542: void
1.74.2.2 jason 1543: session_close(Session *s)
1.2 markus 1544: {
1.74.2.2 jason 1545: debug("session_close: session %d pid %d", s->self, s->pid);
1546: if (s->ttyfd != -1) {
1547: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1548: session_pty_cleanup(s);
1549: }
1.2 markus 1550: if (s->term)
1551: xfree(s->term);
1552: if (s->display)
1553: xfree(s->display);
1.74.2.5 miod 1554: if (s->auth_display)
1555: xfree(s->auth_display);
1.2 markus 1556: if (s->auth_data)
1557: xfree(s->auth_data);
1558: if (s->auth_proto)
1559: xfree(s->auth_proto);
1560: s->used = 0;
1.9 markus 1561: session_proctitle(s);
1.2 markus 1562: }
1563:
1564: void
1565: session_close_by_pid(pid_t pid, int status)
1566: {
1567: Session *s = session_by_pid(pid);
1568: if (s == NULL) {
1.74.2.2 jason 1569: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1570: return;
1571: }
1572: if (s->chanid != -1)
1573: session_exit_message(s, status);
1574: session_close(s);
1575: }
1576:
1577: /*
1578: * this is called when a channel dies before
1579: * the session 'child' itself dies
1580: */
1581: void
1582: session_close_by_channel(int id, void *arg)
1583: {
1584: Session *s = session_by_channel(id);
1585: if (s == NULL) {
1.74.2.3 miod 1586: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 1587: return;
1588: }
1.74.2.3 miod 1589: debug("session_close_by_channel: channel %d child %d", id, s->pid);
1590: if (s->pid != 0) {
1591: debug("session_close_by_channel: channel %d: has child", id);
1592: /*
1593: * delay detach of session, but release pty, since
1594: * the fd's to the child are already closed
1595: */
1596: if (s->ttyfd != -1) {
1597: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1598: session_pty_cleanup(s);
1599: }
1600: return;
1601: }
1602: /* detach by removing callback */
1.2 markus 1603: channel_cancel_cleanup(s->chanid);
1604: s->chanid = -1;
1.74.2.3 miod 1605: session_close(s);
1606: }
1.2 markus 1607:
1.74.2.3 miod 1608: void
1.74.2.6! miod 1609: session_destroy_all(void (*closefunc)(Session *))
1.74.2.3 miod 1610: {
1611: int i;
1.74.2.5 miod 1612: for (i = 0; i < MAX_SESSIONS; i++) {
1.74.2.3 miod 1613: Session *s = &sessions[i];
1.74.2.6! miod 1614: if (s->used) {
! 1615: if (closefunc != NULL)
! 1616: closefunc(s);
! 1617: else
! 1618: session_close(s);
! 1619: }
1.2 markus 1620: }
1.9 markus 1621: }
1622:
1.74.2.2 jason 1623: static char *
1.9 markus 1624: session_tty_list(void)
1625: {
1626: static char buf[1024];
1627: int i;
1628: buf[0] = '\0';
1.74.2.5 miod 1629: for (i = 0; i < MAX_SESSIONS; i++) {
1.9 markus 1630: Session *s = &sessions[i];
1631: if (s->used && s->ttyfd != -1) {
1632: if (buf[0] != '\0')
1633: strlcat(buf, ",", sizeof buf);
1634: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1635: }
1636: }
1637: if (buf[0] == '\0')
1638: strlcpy(buf, "notty", sizeof buf);
1639: return buf;
1640: }
1641:
1642: void
1643: session_proctitle(Session *s)
1644: {
1645: if (s->pw == NULL)
1646: error("no user for session %d", s->self);
1647: else
1648: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1649: }
1650:
1.74.2.2 jason 1651: int
1652: session_setup_x11fwd(Session *s)
1.2 markus 1653: {
1.74.2.2 jason 1654: struct stat st;
1.74.2.5 miod 1655: char display[512], auth_display[512];
1656: char hostname[MAXHOSTNAMELEN];
1.65 markus 1657:
1.74.2.2 jason 1658: if (no_x11_forwarding_flag) {
1659: packet_send_debug("X11 forwarding disabled in user configuration file.");
1660: return 0;
1661: }
1662: if (!options.x11_forwarding) {
1663: debug("X11 forwarding disabled in server configuration file.");
1664: return 0;
1665: }
1666: if (!options.xauth_location ||
1667: (stat(options.xauth_location, &st) == -1)) {
1668: packet_send_debug("No xauth program; cannot forward with spoofing.");
1669: return 0;
1670: }
1671: if (options.use_login) {
1672: packet_send_debug("X11 forwarding disabled; "
1673: "not compatible with UseLogin=yes.");
1674: return 0;
1675: }
1676: if (s->display != NULL) {
1677: debug("X11 display already set.");
1678: return 0;
1679: }
1.74.2.5 miod 1680: s->display_number = x11_create_display_inet(options.x11_display_offset,
1681: options.x11_use_localhost, s->single_connection);
1682: if (s->display_number == -1) {
1.74.2.2 jason 1683: debug("x11_create_display_inet failed.");
1684: return 0;
1685: }
1.74.2.5 miod 1686:
1687: /* Set up a suitable value for the DISPLAY variable. */
1688: if (gethostname(hostname, sizeof(hostname)) < 0)
1689: fatal("gethostname: %.100s", strerror(errno));
1690: /*
1691: * auth_display must be used as the displayname when the
1692: * authorization entry is added with xauth(1). This will be
1693: * different than the DISPLAY string for localhost displays.
1694: */
1695: if (options.x11_use_localhost) {
1696: snprintf(display, sizeof display, "localhost:%d.%d",
1697: s->display_number, s->screen);
1698: snprintf(auth_display, sizeof auth_display, "unix:%d.%d",
1699: s->display_number, s->screen);
1700: s->display = xstrdup(display);
1701: s->auth_display = xstrdup(auth_display);
1702: } else {
1703: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
1704: s->display_number, s->screen);
1705: s->display = xstrdup(display);
1706: s->auth_display = xstrdup(display);
1707: }
1708:
1.74.2.2 jason 1709: return 1;
1710: }
1711:
1712: static void
1713: do_authenticated2(Authctxt *authctxt)
1714: {
1715: server_loop2(authctxt);
1.1 markus 1716: }
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