Annotation of src/usr.bin/ssh/session.c, Revision 1.62
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.
1.58 deraadt 12: * Copyright (c) 2000 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"
1.62 ! markus 36: RCSID("$OpenBSD: session.c,v 1.61 2001/03/16 19:06:30 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"
49: #include "nchan.h"
1.2 markus 50: #include "bufaux.h"
51: #include "auth.h"
1.19 markus 52: #include "auth-options.h"
1.50 markus 53: #include "pathnames.h"
1.51 markus 54: #include "log.h"
55: #include "servconf.h"
1.59 djm 56: #include "sshlogin.h"
1.51 markus 57: #include "serverloop.h"
58: #include "canohost.h"
1.55 itojun 59: #include "session.h"
1.2 markus 60:
1.1 markus 61: /* types */
62:
63: #define TTYSZ 64
64: typedef struct Session Session;
65: struct Session {
66: int used;
67: int self;
1.7 markus 68: int extended;
1.1 markus 69: struct passwd *pw;
70: pid_t pid;
71: /* tty */
72: char *term;
73: int ptyfd, ttyfd, ptymaster;
74: int row, col, xpixel, ypixel;
75: char tty[TTYSZ];
76: /* X11 */
77: char *display;
78: int screen;
79: char *auth_proto;
80: char *auth_data;
1.7 markus 81: int single_connection;
1.1 markus 82: /* proto 2 */
83: int chanid;
84: };
85:
86: /* func */
87:
88: Session *session_new(void);
89: void session_set_fds(Session *s, int fdin, int fdout, int fderr);
90: void session_pty_cleanup(Session *s);
1.9 markus 91: void session_proctitle(Session *s);
1.1 markus 92: void do_exec_pty(Session *s, const char *command, struct passwd * pw);
93: void do_exec_no_pty(Session *s, const char *command, struct passwd * pw);
1.41 markus 94: void do_login(Session *s, const char *command);
1.60 markus 95: void do_child(Session *s, const char *command);
1.1 markus 96:
97: /* import */
98: extern ServerOptions options;
99: extern char *__progname;
100: extern int log_stderr;
101: extern int debug_flag;
1.45 markus 102: extern u_int utmp_len;
1.1 markus 103:
1.21 markus 104: extern int startup_pipe;
105:
1.1 markus 106: /* Local Xauthority file. */
107: static char *xauthfile;
108:
1.34 markus 109: /* original command from peer. */
1.53 stevesk 110: char *original_command = NULL;
1.34 markus 111:
1.1 markus 112: /* data */
113: #define MAX_SESSIONS 10
114: Session sessions[MAX_SESSIONS];
115:
1.28 millert 116: #ifdef HAVE_LOGIN_CAP
117: static login_cap_t *lc;
118: #endif
119:
1.1 markus 120: /*
121: * Remove local Xauthority file.
122: */
123: void
124: xauthfile_cleanup_proc(void *ignore)
125: {
126: debug("xauthfile_cleanup_proc called");
127:
128: if (xauthfile != NULL) {
129: char *p;
130: unlink(xauthfile);
131: p = strrchr(xauthfile, '/');
132: if (p != NULL) {
133: *p = '\0';
134: rmdir(xauthfile);
135: }
136: xfree(xauthfile);
137: xauthfile = NULL;
138: }
139: }
140:
141: /*
142: * Function to perform cleanup if we get aborted abnormally (e.g., due to a
143: * dropped connection).
144: */
1.4 markus 145: void
1.1 markus 146: pty_cleanup_proc(void *session)
147: {
148: Session *s=session;
149: if (s == NULL)
150: fatal("pty_cleanup_proc: no session");
151: debug("pty_cleanup_proc: %s", s->tty);
152:
153: if (s->pid != 0) {
154: /* Record that the user has logged out. */
155: record_logout(s->pid, s->tty);
156: }
157:
158: /* Release the pseudo-tty. */
159: pty_release(s->tty);
160: }
161:
162: /*
163: * Prepares for an interactive session. This is called after the user has
164: * been successfully authenticated. During this message exchange, pseudo
165: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
166: * are requested, etc.
167: */
1.4 markus 168: void
1.1 markus 169: do_authenticated(struct passwd * pw)
170: {
171: Session *s;
1.33 markus 172: int type, fd;
1.1 markus 173: int compression_level = 0, enable_compression_after_reply = 0;
174: int have_pty = 0;
175: char *command;
176: int n_bytes;
177: int plen;
1.45 markus 178: u_int proto_len, data_len, dlen;
1.57 markus 179: int screen_flag;
1.1 markus 180:
181: /*
182: * Cancel the alarm we set to limit the time taken for
183: * authentication.
184: */
185: alarm(0);
1.23 deraadt 186: if (startup_pipe != -1) {
187: close(startup_pipe);
188: startup_pipe = -1;
189: }
1.1 markus 190:
1.61 markus 191: s = session_new();
192: s->pw = pw;
193:
1.39 markus 194: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
1.1 markus 195: channel_permit_all_opens();
196:
1.28 millert 197: #ifdef HAVE_LOGIN_CAP
198: if ((lc = login_getclass(pw->pw_class)) == NULL) {
199: error("unable to get login class");
200: return;
201: }
202: #endif
203:
1.1 markus 204: /*
205: * We stay in this loop until the client requests to execute a shell
206: * or a command.
207: */
208: for (;;) {
209: int success = 0;
210:
211: /* Get a packet from the client. */
212: type = packet_read(&plen);
213:
214: /* Process the packet. */
215: switch (type) {
216: case SSH_CMSG_REQUEST_COMPRESSION:
217: packet_integrity_check(plen, 4, type);
218: compression_level = packet_get_int();
219: if (compression_level < 1 || compression_level > 9) {
220: packet_send_debug("Received illegal compression level %d.",
221: compression_level);
222: break;
223: }
224: /* Enable compression after we have responded with SUCCESS. */
225: enable_compression_after_reply = 1;
226: success = 1;
227: break;
228:
229: case SSH_CMSG_REQUEST_PTY:
230: if (no_pty_flag) {
231: debug("Allocating a pty not permitted for this authentication.");
232: break;
233: }
234: if (have_pty)
235: packet_disconnect("Protocol error: you already have a pty.");
236:
237: debug("Allocating pty.");
238:
239: /* Allocate a pty and open it. */
240: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
241: sizeof(s->tty))) {
242: error("Failed to allocate pty.");
243: break;
244: }
245: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
246: pty_setowner(pw, s->tty);
247:
248: /* Get TERM from the packet. Note that the value may be of arbitrary length. */
249: s->term = packet_get_string(&dlen);
250: packet_integrity_check(dlen, strlen(s->term), type);
251: /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
252: /* Remaining bytes */
253: n_bytes = plen - (4 + dlen + 4 * 4);
254:
255: if (strcmp(s->term, "") == 0) {
256: xfree(s->term);
257: s->term = NULL;
258: }
259: /* Get window size from the packet. */
260: s->row = packet_get_int();
261: s->col = packet_get_int();
262: s->xpixel = packet_get_int();
263: s->ypixel = packet_get_int();
264: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
265:
266: /* Get tty modes from the packet. */
267: tty_parse_modes(s->ttyfd, &n_bytes);
268: packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
1.10 markus 269:
270: session_proctitle(s);
1.1 markus 271:
272: /* Indicate that we now have a pty. */
273: success = 1;
274: have_pty = 1;
275: break;
276:
277: case SSH_CMSG_X11_REQUEST_FORWARDING:
278: if (!options.x11_forwarding) {
279: packet_send_debug("X11 forwarding disabled in server configuration file.");
280: break;
281: }
1.16 markus 282: if (!options.xauth_location) {
283: packet_send_debug("No xauth program; cannot forward with spoofing.");
284: break;
285: }
1.1 markus 286: if (no_x11_forwarding_flag) {
287: packet_send_debug("X11 forwarding not permitted for this authentication.");
288: break;
289: }
290: debug("Received request for X11 forwarding with auth spoofing.");
291: if (s->display != NULL)
292: packet_disconnect("Protocol error: X11 display already set.");
293:
294: s->auth_proto = packet_get_string(&proto_len);
295: s->auth_data = packet_get_string(&data_len);
296:
1.57 markus 297: screen_flag = packet_get_protocol_flags() &
298: SSH_PROTOFLAG_SCREEN_NUMBER;
299: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
300:
301: if (packet_remaining() == 4) {
302: if (!screen_flag)
303: debug2("Buggy client: "
304: "X11 screen flag missing");
1.56 markus 305: packet_integrity_check(plen,
306: 4 + proto_len + 4 + data_len + 4, type);
1.1 markus 307: s->screen = packet_get_int();
1.56 markus 308: } else {
309: packet_integrity_check(plen,
310: 4 + proto_len + 4 + data_len, type);
1.1 markus 311: s->screen = 0;
1.56 markus 312: }
1.1 markus 313: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
314:
315: if (s->display == NULL)
316: break;
317:
318: /* Setup to always have a local .Xauthority. */
319: xauthfile = xmalloc(MAXPATHLEN);
320: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
321: temporarily_use_uid(pw->pw_uid);
322: if (mkdtemp(xauthfile) == NULL) {
323: restore_uid();
324: error("private X11 dir: mkdtemp %s failed: %s",
325: xauthfile, strerror(errno));
326: xfree(xauthfile);
327: xauthfile = NULL;
1.7 markus 328: /* XXXX remove listening channels */
1.1 markus 329: break;
330: }
331: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 332: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
333: if (fd >= 0)
334: close(fd);
1.1 markus 335: restore_uid();
336: fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
337: success = 1;
338: break;
339:
340: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
341: if (no_agent_forwarding_flag || compat13) {
342: debug("Authentication agent forwarding not permitted for this authentication.");
343: break;
344: }
345: debug("Received authentication agent forwarding request.");
1.15 markus 346: success = auth_input_request_forwarding(pw);
1.1 markus 347: break;
348:
349: case SSH_CMSG_PORT_FORWARD_REQUEST:
350: if (no_port_forwarding_flag) {
351: debug("Port forwarding not permitted for this authentication.");
1.39 markus 352: break;
353: }
354: if (!options.allow_tcp_forwarding) {
355: debug("Port forwarding not permitted.");
1.1 markus 356: break;
357: }
358: debug("Received TCP/IP port forwarding request.");
1.12 markus 359: channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
1.1 markus 360: success = 1;
361: break;
362:
363: case SSH_CMSG_MAX_PACKET_SIZE:
364: if (packet_set_maxsize(packet_get_int()) > 0)
365: success = 1;
366: break;
367:
368: case SSH_CMSG_EXEC_SHELL:
369: case SSH_CMSG_EXEC_CMD:
370: if (type == SSH_CMSG_EXEC_CMD) {
371: command = packet_get_string(&dlen);
372: debug("Exec command '%.500s'", command);
373: packet_integrity_check(plen, 4 + dlen, type);
374: } else {
375: command = NULL;
376: packet_integrity_check(plen, 0, type);
377: }
378: if (forced_command != NULL) {
1.34 markus 379: original_command = command;
1.1 markus 380: command = forced_command;
381: debug("Forced command '%.500s'", forced_command);
382: }
383: if (have_pty)
384: do_exec_pty(s, command, pw);
385: else
386: do_exec_no_pty(s, command, pw);
387:
388: if (command != NULL)
389: xfree(command);
390: /* Cleanup user's local Xauthority file. */
391: if (xauthfile)
392: xauthfile_cleanup_proc(NULL);
393: return;
394:
395: default:
396: /*
397: * Any unknown messages in this phase are ignored,
398: * and a failure message is returned.
399: */
400: log("Unknown packet type received after authentication: %d", type);
401: }
402: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
403: packet_send();
404: packet_write_wait();
405:
406: /* Enable compression now that we have replied if appropriate. */
407: if (enable_compression_after_reply) {
408: enable_compression_after_reply = 0;
409: packet_start_compression(compression_level);
410: }
411: }
412: }
413:
414: /*
415: * This is called to fork and execute a command when we have no tty. This
416: * will call do_child from the child, and server_loop from the parent after
417: * setting up file descriptors and such.
418: */
1.4 markus 419: void
1.1 markus 420: do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
421: {
422: int pid;
423:
424: #ifdef USE_PIPES
425: int pin[2], pout[2], perr[2];
426: /* Allocate pipes for communicating with the program. */
427: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
428: packet_disconnect("Could not create pipes: %.100s",
429: strerror(errno));
430: #else /* USE_PIPES */
431: int inout[2], err[2];
432: /* Uses socket pairs to communicate with the program. */
433: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
434: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
435: packet_disconnect("Could not create socket pairs: %.100s",
436: strerror(errno));
437: #endif /* USE_PIPES */
438: if (s == NULL)
439: fatal("do_exec_no_pty: no session");
440:
1.9 markus 441: session_proctitle(s);
1.1 markus 442:
443: /* Fork the child. */
444: if ((pid = fork()) == 0) {
445: /* Child. Reinitialize the log since the pid has changed. */
446: log_init(__progname, options.log_level, options.log_facility, log_stderr);
447:
448: /*
449: * Create a new session and process group since the 4.4BSD
450: * setlogin() affects the entire process group.
451: */
452: if (setsid() < 0)
453: error("setsid failed: %.100s", strerror(errno));
454:
455: #ifdef USE_PIPES
456: /*
457: * Redirect stdin. We close the parent side of the socket
458: * pair, and make the child side the standard input.
459: */
460: close(pin[1]);
461: if (dup2(pin[0], 0) < 0)
462: perror("dup2 stdin");
463: close(pin[0]);
464:
465: /* Redirect stdout. */
466: close(pout[0]);
467: if (dup2(pout[1], 1) < 0)
468: perror("dup2 stdout");
469: close(pout[1]);
470:
471: /* Redirect stderr. */
472: close(perr[0]);
473: if (dup2(perr[1], 2) < 0)
474: perror("dup2 stderr");
475: close(perr[1]);
476: #else /* USE_PIPES */
477: /*
478: * Redirect stdin, stdout, and stderr. Stdin and stdout will
479: * use the same socket, as some programs (particularly rdist)
480: * seem to depend on it.
481: */
482: close(inout[1]);
483: close(err[1]);
484: if (dup2(inout[0], 0) < 0) /* stdin */
485: perror("dup2 stdin");
486: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
487: perror("dup2 stdout");
488: if (dup2(err[0], 2) < 0) /* stderr */
489: perror("dup2 stderr");
490: #endif /* USE_PIPES */
491:
492: /* Do processing for the child (exec command etc). */
1.60 markus 493: do_child(s, command);
1.1 markus 494: /* NOTREACHED */
495: }
496: if (pid < 0)
497: packet_disconnect("fork failed: %.100s", strerror(errno));
498: s->pid = pid;
1.47 markus 499: /* Set interactive/non-interactive mode. */
1.48 markus 500: packet_set_interactive(s->display != NULL);
1.1 markus 501: #ifdef USE_PIPES
502: /* We are the parent. Close the child sides of the pipes. */
503: close(pin[0]);
504: close(pout[1]);
505: close(perr[1]);
506:
1.2 markus 507: if (compat20) {
1.7 markus 508: session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
1.2 markus 509: } else {
510: /* Enter the interactive session. */
511: server_loop(pid, pin[1], pout[0], perr[0]);
512: /* server_loop has closed pin[1], pout[1], and perr[1]. */
513: }
1.1 markus 514: #else /* USE_PIPES */
515: /* We are the parent. Close the child sides of the socket pairs. */
516: close(inout[0]);
517: close(err[0]);
518:
519: /*
520: * Enter the interactive session. Note: server_loop must be able to
521: * handle the case that fdin and fdout are the same.
522: */
1.2 markus 523: if (compat20) {
1.7 markus 524: session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
1.2 markus 525: } else {
526: server_loop(pid, inout[1], inout[1], err[1]);
527: /* server_loop has closed inout[1] and err[1]. */
528: }
1.1 markus 529: #endif /* USE_PIPES */
530: }
531:
532: /*
533: * This is called to fork and execute a command when we have a tty. This
534: * will call do_child from the child, and server_loop from the parent after
535: * setting up file descriptors, controlling tty, updating wtmp, utmp,
536: * lastlog, and other such operations.
537: */
1.4 markus 538: void
1.1 markus 539: do_exec_pty(Session *s, const char *command, struct passwd * pw)
540: {
541: int fdout, ptyfd, ttyfd, ptymaster;
542: pid_t pid;
543:
544: if (s == NULL)
545: fatal("do_exec_pty: no session");
546: ptyfd = s->ptyfd;
547: ttyfd = s->ttyfd;
548:
549: /* Fork the child. */
550: if ((pid = fork()) == 0) {
1.24 markus 551: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 552: log_init(__progname, options.log_level, options.log_facility, log_stderr);
553:
554: /* Close the master side of the pseudo tty. */
555: close(ptyfd);
556:
557: /* Make the pseudo tty our controlling tty. */
558: pty_make_controlling_tty(&ttyfd, s->tty);
559:
560: /* Redirect stdin from the pseudo tty. */
561: if (dup2(ttyfd, fileno(stdin)) < 0)
562: error("dup2 stdin failed: %.100s", strerror(errno));
563:
564: /* Redirect stdout to the pseudo tty. */
565: if (dup2(ttyfd, fileno(stdout)) < 0)
566: error("dup2 stdin failed: %.100s", strerror(errno));
567:
568: /* Redirect stderr to the pseudo tty. */
569: if (dup2(ttyfd, fileno(stderr)) < 0)
570: error("dup2 stdin failed: %.100s", strerror(errno));
571:
572: /* Close the extra descriptor for the pseudo tty. */
573: close(ttyfd);
574:
1.24 markus 575: /* record login, etc. similar to login(1) */
1.41 markus 576: if (!(options.use_login && command == NULL))
577: do_login(s, command);
1.1 markus 578:
579: /* Do common processing for the child, such as execing the command. */
1.60 markus 580: do_child(s, command);
1.1 markus 581: /* NOTREACHED */
582: }
583: if (pid < 0)
584: packet_disconnect("fork failed: %.100s", strerror(errno));
585: s->pid = pid;
586:
587: /* Parent. Close the slave side of the pseudo tty. */
588: close(ttyfd);
589:
590: /*
591: * Create another descriptor of the pty master side for use as the
592: * standard input. We could use the original descriptor, but this
593: * simplifies code in server_loop. The descriptor is bidirectional.
594: */
595: fdout = dup(ptyfd);
596: if (fdout < 0)
597: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
598:
599: /* we keep a reference to the pty master */
600: ptymaster = dup(ptyfd);
601: if (ptymaster < 0)
602: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
603: s->ptymaster = ptymaster;
604:
605: /* Enter interactive session. */
1.47 markus 606: packet_set_interactive(1);
1.2 markus 607: if (compat20) {
608: session_set_fds(s, ptyfd, fdout, -1);
609: } else {
610: server_loop(pid, ptyfd, fdout, -1);
611: /* server_loop _has_ closed ptyfd and fdout. */
612: session_pty_cleanup(s);
1.24 markus 613: }
614: }
615:
1.25 markus 616: const char *
617: get_remote_name_or_ip(void)
618: {
619: static const char *remote = "";
620: if (utmp_len > 0)
1.52 markus 621: remote = get_canonical_hostname(options.reverse_mapping_check);
1.25 markus 622: if (utmp_len == 0 || strlen(remote) > utmp_len)
623: remote = get_remote_ipaddr();
624: return remote;
625: }
626:
1.24 markus 627: /* administrative, login(1)-like work */
628: void
1.41 markus 629: do_login(Session *s, const char *command)
1.24 markus 630: {
631: FILE *f;
632: char *time_string;
633: char buf[256];
1.35 markus 634: char hostname[MAXHOSTNAMELEN];
1.24 markus 635: socklen_t fromlen;
636: struct sockaddr_storage from;
637: struct stat st;
638: time_t last_login_time;
639: struct passwd * pw = s->pw;
640: pid_t pid = getpid();
641:
642: /*
643: * Get IP address of client. If the connection is not a socket, let
644: * the address be 0.0.0.0.
645: */
646: memset(&from, 0, sizeof(from));
647: if (packet_connection_is_on_socket()) {
648: fromlen = sizeof(from);
649: if (getpeername(packet_get_connection_in(),
650: (struct sockaddr *) & from, &fromlen) < 0) {
651: debug("getpeername: %.100s", strerror(errno));
652: fatal_cleanup();
653: }
654: }
1.25 markus 655:
1.35 markus 656: /* Get the time and hostname when the user last logged in. */
1.36 markus 657: hostname[0] = '\0';
1.35 markus 658: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
659: hostname, sizeof(hostname));
660:
1.24 markus 661: /* Record that there was a login on that tty from the remote host. */
662: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.25 markus 663: get_remote_name_or_ip(), (struct sockaddr *)&from);
1.24 markus 664:
1.41 markus 665: /* Done if .hushlogin exists or a command given. */
666: if (command != NULL)
667: return;
1.24 markus 668: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
1.28 millert 669: #ifdef HAVE_LOGIN_CAP
670: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
671: #else
1.24 markus 672: if (stat(buf, &st) >= 0)
1.28 millert 673: #endif
1.24 markus 674: return;
675: if (last_login_time != 0) {
676: time_string = ctime(&last_login_time);
677: if (strchr(time_string, '\n'))
678: *strchr(time_string, '\n') = 0;
1.40 markus 679: if (strcmp(hostname, "") == 0)
1.24 markus 680: printf("Last login: %s\r\n", time_string);
681: else
1.36 markus 682: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 683: }
684: if (options.print_motd) {
1.28 millert 685: #ifdef HAVE_LOGIN_CAP
686: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
687: "/etc/motd"), "r");
688: #else
1.24 markus 689: f = fopen("/etc/motd", "r");
1.28 millert 690: #endif
1.24 markus 691: if (f) {
692: while (fgets(buf, sizeof(buf), f))
693: fputs(buf, stdout);
694: fclose(f);
695: }
1.2 markus 696: }
1.1 markus 697: }
698:
699: /*
700: * Sets the value of the given variable in the environment. If the variable
701: * already exists, its value is overriden.
702: */
1.4 markus 703: void
1.45 markus 704: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 705: const char *value)
706: {
1.45 markus 707: u_int i, namelen;
1.1 markus 708: char **env;
709:
710: /*
711: * Find the slot where the value should be stored. If the variable
712: * already exists, we reuse the slot; otherwise we append a new slot
713: * at the end of the array, expanding if necessary.
714: */
715: env = *envp;
716: namelen = strlen(name);
717: for (i = 0; env[i]; i++)
718: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
719: break;
720: if (env[i]) {
721: /* Reuse the slot. */
722: xfree(env[i]);
723: } else {
724: /* New variable. Expand if necessary. */
725: if (i >= (*envsizep) - 1) {
726: (*envsizep) += 50;
727: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
728: }
729: /* Need to set the NULL pointer at end of array beyond the new slot. */
730: env[i + 1] = NULL;
731: }
732:
733: /* Allocate space and format the variable in the appropriate slot. */
734: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
735: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
736: }
737:
738: /*
739: * Reads environment variables from the given file and adds/overrides them
740: * into the environment. If the file does not exist, this does nothing.
741: * Otherwise, it must consist of empty lines, comments (line starts with '#')
742: * and assignments of the form name=value. No other forms are allowed.
743: */
1.4 markus 744: void
1.45 markus 745: read_environment_file(char ***env, u_int *envsize,
1.1 markus 746: const char *filename)
747: {
748: FILE *f;
749: char buf[4096];
750: char *cp, *value;
751:
752: f = fopen(filename, "r");
753: if (!f)
754: return;
755:
756: while (fgets(buf, sizeof(buf), f)) {
757: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
758: ;
759: if (!*cp || *cp == '#' || *cp == '\n')
760: continue;
761: if (strchr(cp, '\n'))
762: *strchr(cp, '\n') = '\0';
763: value = strchr(cp, '=');
764: if (value == NULL) {
765: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
766: continue;
767: }
1.14 deraadt 768: /*
769: * Replace the equals sign by nul, and advance value to
770: * the value string.
771: */
1.1 markus 772: *value = '\0';
773: value++;
774: child_set_env(env, envsize, cp, value);
775: }
776: fclose(f);
777: }
778:
779: /*
780: * Performs common processing for the child, such as setting up the
781: * environment, closing extra file descriptors, setting the user and group
782: * ids, and executing the command or shell.
783: */
1.4 markus 784: void
1.60 markus 785: do_child(Session *s, const char *command)
1.1 markus 786: {
1.32 markus 787: const char *shell, *hostname = NULL, *cp = NULL;
1.60 markus 788: struct passwd * pw = s->pw;
1.1 markus 789: char buf[256];
1.16 markus 790: char cmd[1024];
1.27 millert 791: FILE *f = NULL;
1.45 markus 792: u_int envsize, i;
1.1 markus 793: char **env;
794: extern char **environ;
795: struct stat st;
796: char *argv[10];
1.60 markus 797: int do_xauth = s->auth_proto != NULL && s->auth_data != NULL;
1.17 markus 798:
799: /* login(1) is only called if we execute the login shell */
800: if (options.use_login && command != NULL)
801: options.use_login = 0;
1.1 markus 802:
1.27 millert 803: if (!options.use_login) {
1.28 millert 804: #ifdef HAVE_LOGIN_CAP
805: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
806: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
807: _PATH_NOLOGIN), "r");
808: #else
1.27 millert 809: if (pw->pw_uid)
810: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 811: #endif
1.27 millert 812: if (f) {
813: /* /etc/nologin exists. Print its contents and exit. */
814: while (fgets(buf, sizeof(buf), f))
815: fputs(buf, stderr);
816: fclose(f);
1.1 markus 817: exit(254);
1.27 millert 818: }
1.1 markus 819: }
1.28 millert 820: /* Set login name, uid, gid, and groups. */
1.1 markus 821: /* Login(1) does this as well, and it needs uid 0 for the "-h"
822: switch, so we let login(1) to this for us. */
823: if (!options.use_login) {
824: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 825: #ifdef HAVE_LOGIN_CAP
826: if (setusercontext(lc, pw, pw->pw_uid,
827: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
828: perror("unable to set user context");
829: exit(1);
830: }
1.62 ! markus 831: #ifdef BSD_AUTH
! 832: if (auth_approval(NULL, lc, pw->pw_name, "ssh") <= 0) {
! 833: error("approval failure for %s", pw->pw_name);
! 834: fprintf(stderr, "Approval failure");
! 835: exit(1);
! 836: }
! 837: #endif
1.28 millert 838: #else
839: if (setlogin(pw->pw_name) < 0)
840: error("setlogin failed: %s", strerror(errno));
1.1 markus 841: if (setgid(pw->pw_gid) < 0) {
842: perror("setgid");
843: exit(1);
844: }
845: /* Initialize the group list. */
846: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
847: perror("initgroups");
848: exit(1);
849: }
850: endgrent();
851:
852: /* Permanently switch to the desired uid. */
853: permanently_set_uid(pw->pw_uid);
1.28 millert 854: #endif
1.1 markus 855: }
856: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 857: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 858: }
859: /*
860: * Get the shell from the password data. An empty shell field is
861: * legal, and means /bin/sh.
862: */
863: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 864: #ifdef HAVE_LOGIN_CAP
865: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
866: #endif
1.1 markus 867:
868: #ifdef AFS
869: /* Try to get AFS tokens for the local cell. */
870: if (k_hasafs()) {
871: char cell[64];
872:
873: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
874: krb_afslog(cell, 0);
875:
876: krb_afslog(0, 0);
877: }
878: #endif /* AFS */
879:
880: /* Initialize the environment. */
881: envsize = 100;
882: env = xmalloc(envsize * sizeof(char *));
883: env[0] = NULL;
884:
885: if (!options.use_login) {
886: /* Set basic environment. */
887: child_set_env(&env, &envsize, "USER", pw->pw_name);
888: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
889: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 890: #ifdef HAVE_LOGIN_CAP
1.29 millert 891: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
892: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 893: #else
1.29 millert 894: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 895: #endif
1.1 markus 896:
897: snprintf(buf, sizeof buf, "%.200s/%.50s",
898: _PATH_MAILDIR, pw->pw_name);
899: child_set_env(&env, &envsize, "MAIL", buf);
900:
901: /* Normal systems set SHELL by default. */
902: child_set_env(&env, &envsize, "SHELL", shell);
903: }
904: if (getenv("TZ"))
905: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
906:
907: /* Set custom environment options from RSA authentication. */
908: while (custom_environment) {
909: struct envstring *ce = custom_environment;
910: char *s = ce->s;
911: int i;
912: for (i = 0; s[i] != '=' && s[i]; i++);
913: if (s[i] == '=') {
914: s[i] = 0;
915: child_set_env(&env, &envsize, s, s + i + 1);
916: }
917: custom_environment = ce->next;
918: xfree(ce->s);
919: xfree(ce);
920: }
921:
922: snprintf(buf, sizeof buf, "%.50s %d %d",
923: get_remote_ipaddr(), get_remote_port(), get_local_port());
924: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
925:
1.60 markus 926: if (s->ttyfd != -1)
927: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
928: if (s->term)
929: child_set_env(&env, &envsize, "TERM", s->term);
930: if (s->display)
931: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 932: if (original_command)
933: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
934: original_command);
1.1 markus 935:
936: #ifdef KRB4
937: {
938: extern char *ticket;
939:
940: if (ticket)
941: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
942: }
943: #endif /* KRB4 */
944:
945: if (xauthfile)
946: child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
947: if (auth_get_socket_name() != NULL)
948: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
949: auth_get_socket_name());
950:
951: /* read $HOME/.ssh/environment. */
952: if (!options.use_login) {
1.14 deraadt 953: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
954: pw->pw_dir);
1.1 markus 955: read_environment_file(&env, &envsize, buf);
956: }
957: if (debug_flag) {
958: /* dump the environment */
959: fprintf(stderr, "Environment:\n");
960: for (i = 0; env[i]; i++)
961: fprintf(stderr, " %.200s\n", env[i]);
962: }
1.26 millert 963: /* we have to stash the hostname before we close our socket. */
964: if (options.use_login)
965: hostname = get_remote_name_or_ip();
1.1 markus 966: /*
967: * Close the connection descriptors; note that this is the child, and
968: * the server will still have the socket open, and it is important
969: * that we do not shutdown it. Note that the descriptors cannot be
970: * closed before building the environment, as we call
971: * get_remote_ipaddr there.
972: */
973: if (packet_get_connection_in() == packet_get_connection_out())
974: close(packet_get_connection_in());
975: else {
976: close(packet_get_connection_in());
977: close(packet_get_connection_out());
978: }
979: /*
980: * Close all descriptors related to channels. They will still remain
981: * open in the parent.
982: */
983: /* XXX better use close-on-exec? -markus */
984: channel_close_all();
985:
986: /*
987: * Close any extra file descriptors. Note that there may still be
988: * descriptors left by system functions. They will be closed later.
989: */
990: endpwent();
991:
992: /*
993: * Close any extra open file descriptors so that we don\'t have them
994: * hanging around in clients. Note that we want to do this after
995: * initgroups, because at least on Solaris 2.3 it leaves file
996: * descriptors open.
997: */
998: for (i = 3; i < 64; i++)
999: close(i);
1000:
1001: /* Change current directory to the user\'s home directory. */
1.28 millert 1002: if (chdir(pw->pw_dir) < 0) {
1.1 markus 1003: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1004: pw->pw_dir, strerror(errno));
1.28 millert 1005: #ifdef HAVE_LOGIN_CAP
1006: if (login_getcapbool(lc, "requirehome", 0))
1007: exit(1);
1008: #endif
1009: }
1.1 markus 1010:
1011: /*
1012: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1013: * xauth are run in the proper environment.
1014: */
1015: environ = env;
1016:
1017: /*
1018: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1019: * in this order).
1020: */
1021: if (!options.use_login) {
1.50 markus 1022: if (stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.1 markus 1023: if (debug_flag)
1.60 markus 1024: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1025: _PATH_SSH_USER_RC);
1.50 markus 1026: f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w");
1.1 markus 1027: if (f) {
1.60 markus 1028: if (do_xauth)
1029: fprintf(f, "%s %s\n", s->auth_proto,
1030: s->auth_data);
1.1 markus 1031: pclose(f);
1032: } else
1.60 markus 1033: fprintf(stderr, "Could not run %s\n",
1034: _PATH_SSH_USER_RC);
1.50 markus 1035: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 1036: if (debug_flag)
1.60 markus 1037: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1038: _PATH_SSH_SYSTEM_RC);
1.50 markus 1039: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 1040: if (f) {
1.60 markus 1041: if (do_xauth)
1042: fprintf(f, "%s %s\n", s->auth_proto,
1043: s->auth_data);
1.1 markus 1044: pclose(f);
1045: } else
1.60 markus 1046: fprintf(stderr, "Could not run %s\n",
1047: _PATH_SSH_SYSTEM_RC);
1048: } else if (do_xauth && options.xauth_location != NULL) {
1.1 markus 1049: /* Add authority data to .Xauthority if appropriate. */
1.60 markus 1050: char *screen = strchr(s->display, ':');
1051:
1052: if (debug_flag) {
1053: fprintf(stderr,
1054: "Running %.100s add "
1055: "%.100s %.100s %.100s\n",
1056: options.xauth_location, s->display,
1057: s->auth_proto, s->auth_data);
1058: if (screen != NULL)
1.14 deraadt 1059: fprintf(stderr,
1.60 markus 1060: "Adding %.*s/unix%s %s %s\n",
1061: (int)(screen - s->display),
1062: s->display, screen,
1063: s->auth_proto, s->auth_data);
1064: }
1065: snprintf(cmd, sizeof cmd, "%s -q -",
1066: options.xauth_location);
1067: f = popen(cmd, "w");
1068: if (f) {
1069: fprintf(f, "add %s %s %s\n", s->display,
1070: s->auth_proto, s->auth_data);
1071: if (screen != NULL)
1072: fprintf(f, "add %.*s/unix%s %s %s\n",
1073: (int)(screen - s->display),
1074: s->display, screen,
1075: s->auth_proto,
1076: s->auth_data);
1077: pclose(f);
1078: } else {
1079: fprintf(stderr, "Could not run %s\n",
1080: cmd);
1.1 markus 1081: }
1082: }
1083: /* Get the last component of the shell name. */
1084: cp = strrchr(shell, '/');
1085: if (cp)
1086: cp++;
1087: else
1088: cp = shell;
1089: }
1090: /*
1091: * If we have no command, execute the shell. In this case, the shell
1092: * name to be passed in argv[0] is preceded by '-' to indicate that
1093: * this is a login shell.
1094: */
1095: if (!command) {
1096: if (!options.use_login) {
1097: char buf[256];
1098:
1099: /*
1100: * Check for mail if we have a tty and it was enabled
1101: * in server options.
1102: */
1.60 markus 1103: if (s->ttyfd != -1 && options.check_mail) {
1.1 markus 1104: char *mailbox;
1105: struct stat mailstat;
1.60 markus 1106:
1.1 markus 1107: mailbox = getenv("MAIL");
1108: if (mailbox != NULL) {
1.14 deraadt 1109: if (stat(mailbox, &mailstat) != 0 ||
1110: mailstat.st_size == 0)
1.1 markus 1111: printf("No mail.\n");
1112: else if (mailstat.st_mtime < mailstat.st_atime)
1113: printf("You have mail.\n");
1114: else
1115: printf("You have new mail.\n");
1116: }
1117: }
1118: /* Start the shell. Set initial character to '-'. */
1119: buf[0] = '-';
1120: strncpy(buf + 1, cp, sizeof(buf) - 1);
1121: buf[sizeof(buf) - 1] = 0;
1122:
1123: /* Execute the shell. */
1124: argv[0] = buf;
1125: argv[1] = NULL;
1126: execve(shell, argv, env);
1127:
1128: /* Executing the shell failed. */
1129: perror(shell);
1130: exit(1);
1131:
1132: } else {
1133: /* Launch login(1). */
1134:
1.26 millert 1135: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1136: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1137:
1138: /* Login couldn't be executed, die. */
1139:
1140: perror("login");
1141: exit(1);
1142: }
1143: }
1144: /*
1145: * Execute the command using the user's shell. This uses the -c
1146: * option to execute the command.
1147: */
1148: argv[0] = (char *) cp;
1149: argv[1] = "-c";
1150: argv[2] = (char *) command;
1151: argv[3] = NULL;
1152: execve(shell, argv, env);
1153: perror(shell);
1154: exit(1);
1155: }
1156:
1157: Session *
1158: session_new(void)
1159: {
1160: int i;
1161: static int did_init = 0;
1162: if (!did_init) {
1163: debug("session_new: init");
1164: for(i = 0; i < MAX_SESSIONS; i++) {
1165: sessions[i].used = 0;
1166: sessions[i].self = i;
1167: }
1168: did_init = 1;
1169: }
1170: for(i = 0; i < MAX_SESSIONS; i++) {
1171: Session *s = &sessions[i];
1172: if (! s->used) {
1173: s->pid = 0;
1.7 markus 1174: s->extended = 0;
1.1 markus 1175: s->chanid = -1;
1176: s->ptyfd = -1;
1177: s->ttyfd = -1;
1178: s->term = NULL;
1179: s->pw = NULL;
1180: s->display = NULL;
1181: s->screen = 0;
1182: s->auth_data = NULL;
1183: s->auth_proto = NULL;
1184: s->used = 1;
1.7 markus 1185: s->pw = NULL;
1.1 markus 1186: debug("session_new: session %d", i);
1187: return s;
1188: }
1189: }
1190: return NULL;
1191: }
1192:
1193: void
1194: session_dump(void)
1195: {
1196: int i;
1197: for(i = 0; i < MAX_SESSIONS; i++) {
1198: Session *s = &sessions[i];
1199: debug("dump: used %d session %d %p channel %d pid %d",
1200: s->used,
1201: s->self,
1202: s,
1203: s->chanid,
1204: s->pid);
1205: }
1206: }
1207:
1.2 markus 1208: int
1209: session_open(int chanid)
1210: {
1211: Session *s = session_new();
1212: debug("session_open: channel %d", chanid);
1213: if (s == NULL) {
1214: error("no more sessions");
1215: return 0;
1216: }
1.7 markus 1217: s->pw = auth_get_user();
1218: if (s->pw == NULL)
1.54 stevesk 1219: fatal("no user for session %d", s->self);
1.2 markus 1220: debug("session_open: session %d: link with channel %d", s->self, chanid);
1221: s->chanid = chanid;
1222: return 1;
1223: }
1224:
1225: Session *
1226: session_by_channel(int id)
1227: {
1228: int i;
1229: for(i = 0; i < MAX_SESSIONS; i++) {
1230: Session *s = &sessions[i];
1231: if (s->used && s->chanid == id) {
1232: debug("session_by_channel: session %d channel %d", i, id);
1233: return s;
1234: }
1235: }
1236: debug("session_by_channel: unknown channel %d", id);
1237: session_dump();
1238: return NULL;
1239: }
1240:
1241: Session *
1242: session_by_pid(pid_t pid)
1243: {
1244: int i;
1245: debug("session_by_pid: pid %d", pid);
1246: for(i = 0; i < MAX_SESSIONS; i++) {
1247: Session *s = &sessions[i];
1248: if (s->used && s->pid == pid)
1249: return s;
1250: }
1251: error("session_by_pid: unknown pid %d", pid);
1252: session_dump();
1253: return NULL;
1254: }
1255:
1256: int
1257: session_window_change_req(Session *s)
1258: {
1259: s->col = packet_get_int();
1260: s->row = packet_get_int();
1261: s->xpixel = packet_get_int();
1262: s->ypixel = packet_get_int();
1.3 markus 1263: packet_done();
1.2 markus 1264: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1265: return 1;
1266: }
1267:
1268: int
1269: session_pty_req(Session *s)
1270: {
1.45 markus 1271: u_int len;
1.3 markus 1272: char *term_modes; /* encoded terminal modes */
1.2 markus 1273:
1.19 markus 1274: if (no_pty_flag)
1275: return 0;
1.2 markus 1276: if (s->ttyfd != -1)
1.3 markus 1277: return 0;
1.2 markus 1278: s->term = packet_get_string(&len);
1279: s->col = packet_get_int();
1280: s->row = packet_get_int();
1281: s->xpixel = packet_get_int();
1282: s->ypixel = packet_get_int();
1.3 markus 1283: term_modes = packet_get_string(&len);
1284: packet_done();
1.2 markus 1285:
1286: if (strcmp(s->term, "") == 0) {
1287: xfree(s->term);
1288: s->term = NULL;
1289: }
1290: /* Allocate a pty and open it. */
1291: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1292: xfree(s->term);
1293: s->term = NULL;
1294: s->ptyfd = -1;
1295: s->ttyfd = -1;
1296: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1297: xfree(term_modes);
1298: return 0;
1.2 markus 1299: }
1300: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1301: /*
1302: * Add a cleanup function to clear the utmp entry and record logout
1303: * time in case we call fatal() (e.g., the connection gets closed).
1304: */
1305: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1306: pty_setowner(s->pw, s->tty);
1307: /* Get window size from the packet. */
1308: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1309:
1.9 markus 1310: session_proctitle(s);
1311:
1.3 markus 1312: /* XXX parse and set terminal modes */
1313: xfree(term_modes);
1.2 markus 1314: return 1;
1315: }
1316:
1.7 markus 1317: int
1318: session_subsystem_req(Session *s)
1319: {
1.45 markus 1320: u_int len;
1.7 markus 1321: int success = 0;
1322: char *subsys = packet_get_string(&len);
1.18 jakob 1323: int i;
1.7 markus 1324:
1325: packet_done();
1326: log("subsystem request for %s", subsys);
1.18 jakob 1327:
1328: for (i = 0; i < options.num_subsystems; i++) {
1329: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1330: debug("subsystem: exec() %s", options.subsystem_command[i]);
1331: do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1332: success = 1;
1333: }
1334: }
1335:
1336: if (!success)
1337: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1338:
1339: xfree(subsys);
1340: return success;
1341: }
1342:
1343: int
1344: session_x11_req(Session *s)
1345: {
1.33 markus 1346: int fd;
1.22 deraadt 1347: if (no_x11_forwarding_flag) {
1.19 markus 1348: debug("X11 forwarding disabled in user configuration file.");
1349: return 0;
1350: }
1.7 markus 1351: if (!options.x11_forwarding) {
1352: debug("X11 forwarding disabled in server configuration file.");
1353: return 0;
1354: }
1355: if (xauthfile != NULL) {
1356: debug("X11 fwd already started.");
1357: return 0;
1358: }
1359:
1360: debug("Received request for X11 forwarding with auth spoofing.");
1361: if (s->display != NULL)
1362: packet_disconnect("Protocol error: X11 display already set.");
1363:
1364: s->single_connection = packet_get_char();
1365: s->auth_proto = packet_get_string(NULL);
1366: s->auth_data = packet_get_string(NULL);
1367: s->screen = packet_get_int();
1368: packet_done();
1369:
1370: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1371: if (s->display == NULL) {
1372: xfree(s->auth_proto);
1373: xfree(s->auth_data);
1374: return 0;
1375: }
1376: xauthfile = xmalloc(MAXPATHLEN);
1377: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1378: temporarily_use_uid(s->pw->pw_uid);
1379: if (mkdtemp(xauthfile) == NULL) {
1380: restore_uid();
1381: error("private X11 dir: mkdtemp %s failed: %s",
1382: xauthfile, strerror(errno));
1383: xfree(xauthfile);
1384: xauthfile = NULL;
1385: xfree(s->auth_proto);
1386: xfree(s->auth_data);
1387: /* XXXX remove listening channels */
1388: return 0;
1389: }
1390: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 1391: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1392: if (fd >= 0)
1393: close(fd);
1.7 markus 1394: restore_uid();
1395: fatal_add_cleanup(xauthfile_cleanup_proc, s);
1396: return 1;
1397: }
1398:
1.19 markus 1399: int
1400: session_shell_req(Session *s)
1401: {
1402: /* if forced_command == NULL, the shell is execed */
1403: char *shell = forced_command;
1404: packet_done();
1405: s->extended = 1;
1406: if (s->ttyfd == -1)
1407: do_exec_no_pty(s, shell, s->pw);
1408: else
1409: do_exec_pty(s, shell, s->pw);
1410: return 1;
1411: }
1412:
1413: int
1414: session_exec_req(Session *s)
1415: {
1.45 markus 1416: u_int len;
1.19 markus 1417: char *command = packet_get_string(&len);
1418: packet_done();
1419: if (forced_command) {
1.34 markus 1420: original_command = command;
1.19 markus 1421: command = forced_command;
1422: debug("Forced command '%.500s'", forced_command);
1423: }
1424: s->extended = 1;
1425: if (s->ttyfd == -1)
1426: do_exec_no_pty(s, command, s->pw);
1427: else
1428: do_exec_pty(s, command, s->pw);
1429: if (forced_command == NULL)
1430: xfree(command);
1431: return 1;
1432: }
1433:
1.43 markus 1434: int
1435: session_auth_agent_req(Session *s)
1436: {
1437: static int called = 0;
1438: packet_done();
1.44 markus 1439: if (no_agent_forwarding_flag) {
1440: debug("session_auth_agent_req: no_agent_forwarding_flag");
1441: return 0;
1442: }
1.43 markus 1443: if (called) {
1444: return 0;
1445: } else {
1446: called = 1;
1447: return auth_input_request_forwarding(s->pw);
1448: }
1449: }
1450:
1.2 markus 1451: void
1452: session_input_channel_req(int id, void *arg)
1453: {
1.45 markus 1454: u_int len;
1.2 markus 1455: int reply;
1456: int success = 0;
1457: char *rtype;
1458: Session *s;
1459: Channel *c;
1460:
1461: rtype = packet_get_string(&len);
1462: reply = packet_get_char();
1463:
1464: s = session_by_channel(id);
1465: if (s == NULL)
1466: fatal("session_input_channel_req: channel %d: no session", id);
1467: c = channel_lookup(id);
1468: if (c == NULL)
1469: fatal("session_input_channel_req: channel %d: bad channel", id);
1470:
1471: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1472: s->self, id, rtype, reply);
1473:
1474: /*
1475: * a session is in LARVAL state until a shell
1476: * or programm is executed
1477: */
1478: if (c->type == SSH_CHANNEL_LARVAL) {
1479: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1480: success = session_shell_req(s);
1.2 markus 1481: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1482: success = session_exec_req(s);
1.2 markus 1483: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1484: success = session_pty_req(s);
1.7 markus 1485: } else if (strcmp(rtype, "x11-req") == 0) {
1486: success = session_x11_req(s);
1.43 markus 1487: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1488: success = session_auth_agent_req(s);
1.7 markus 1489: } else if (strcmp(rtype, "subsystem") == 0) {
1490: success = session_subsystem_req(s);
1.2 markus 1491: }
1492: }
1493: if (strcmp(rtype, "window-change") == 0) {
1494: success = session_window_change_req(s);
1495: }
1496:
1497: if (reply) {
1498: packet_start(success ?
1499: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1500: packet_put_int(c->remote_id);
1501: packet_send();
1502: }
1503: xfree(rtype);
1504: }
1505:
1506: void
1507: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1508: {
1509: if (!compat20)
1510: fatal("session_set_fds: called for proto != 2.0");
1511: /*
1512: * now that have a child and a pipe to the child,
1513: * we can activate our channel and register the fd's
1514: */
1515: if (s->chanid == -1)
1516: fatal("no channel for session %d", s->self);
1517: channel_set_fds(s->chanid,
1518: fdout, fdin, fderr,
1.42 markus 1519: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1520: 1);
1.2 markus 1521: }
1522:
1.1 markus 1523: void
1524: session_pty_cleanup(Session *s)
1525: {
1526: if (s == NULL || s->ttyfd == -1)
1527: return;
1528:
1.54 stevesk 1529: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1530:
1531: /* Cancel the cleanup function. */
1532: fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1533:
1534: /* Record that the user has logged out. */
1535: record_logout(s->pid, s->tty);
1536:
1537: /* Release the pseudo-tty. */
1538: pty_release(s->tty);
1539:
1540: /*
1541: * Close the server side of the socket pairs. We must do this after
1542: * the pty cleanup, so that another process doesn't get this pty
1543: * while we're still cleaning up.
1544: */
1545: if (close(s->ptymaster) < 0)
1546: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1547: }
1548:
1549: void
1550: session_exit_message(Session *s, int status)
1551: {
1552: Channel *c;
1553: if (s == NULL)
1554: fatal("session_close: no session");
1555: c = channel_lookup(s->chanid);
1556: if (c == NULL)
1557: fatal("session_close: session %d: no channel %d",
1558: s->self, s->chanid);
1559: debug("session_exit_message: session %d channel %d pid %d",
1560: s->self, s->chanid, s->pid);
1561:
1562: if (WIFEXITED(status)) {
1563: channel_request_start(s->chanid,
1564: "exit-status", 0);
1565: packet_put_int(WEXITSTATUS(status));
1566: packet_send();
1567: } else if (WIFSIGNALED(status)) {
1568: channel_request_start(s->chanid,
1569: "exit-signal", 0);
1570: packet_put_int(WTERMSIG(status));
1571: packet_put_char(WCOREDUMP(status));
1572: packet_put_cstring("");
1573: packet_put_cstring("");
1574: packet_send();
1575: } else {
1576: /* Some weird exit cause. Just exit. */
1577: packet_disconnect("wait returned status %04x.", status);
1578: }
1579:
1580: /* disconnect channel */
1581: debug("session_exit_message: release channel %d", s->chanid);
1582: channel_cancel_cleanup(s->chanid);
1.5 markus 1583: /*
1584: * emulate a write failure with 'chan_write_failed', nobody will be
1585: * interested in data we write.
1586: * Note that we must not call 'chan_read_failed', since there could
1587: * be some more data waiting in the pipe.
1588: */
1.8 markus 1589: if (c->ostate != CHAN_OUTPUT_CLOSED)
1590: chan_write_failed(c);
1.2 markus 1591: s->chanid = -1;
1592: }
1593:
1594: void
1595: session_free(Session *s)
1596: {
1597: debug("session_free: session %d pid %d", s->self, s->pid);
1598: if (s->term)
1599: xfree(s->term);
1600: if (s->display)
1601: xfree(s->display);
1602: if (s->auth_data)
1603: xfree(s->auth_data);
1604: if (s->auth_proto)
1605: xfree(s->auth_proto);
1606: s->used = 0;
1607: }
1608:
1609: void
1610: session_close(Session *s)
1611: {
1612: session_pty_cleanup(s);
1613: session_free(s);
1.9 markus 1614: session_proctitle(s);
1.2 markus 1615: }
1616:
1617: void
1618: session_close_by_pid(pid_t pid, int status)
1619: {
1620: Session *s = session_by_pid(pid);
1621: if (s == NULL) {
1622: debug("session_close_by_pid: no session for pid %d", s->pid);
1623: return;
1624: }
1625: if (s->chanid != -1)
1626: session_exit_message(s, status);
1627: session_close(s);
1628: }
1629:
1630: /*
1631: * this is called when a channel dies before
1632: * the session 'child' itself dies
1633: */
1634: void
1635: session_close_by_channel(int id, void *arg)
1636: {
1637: Session *s = session_by_channel(id);
1638: if (s == NULL) {
1639: debug("session_close_by_channel: no session for channel %d", id);
1640: return;
1641: }
1642: /* disconnect channel */
1643: channel_cancel_cleanup(s->chanid);
1644: s->chanid = -1;
1645:
1646: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1647: if (s->pid == 0) {
1648: /* close session immediately */
1649: session_close(s);
1650: } else {
1651: /* notify child, delay session cleanup */
1652: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1653: error("session_close_by_channel: kill %d: %s",
1654: s->pid, strerror(errno));
1655: }
1.9 markus 1656: }
1657:
1658: char *
1659: session_tty_list(void)
1660: {
1661: static char buf[1024];
1662: int i;
1663: buf[0] = '\0';
1664: for(i = 0; i < MAX_SESSIONS; i++) {
1665: Session *s = &sessions[i];
1666: if (s->used && s->ttyfd != -1) {
1667: if (buf[0] != '\0')
1668: strlcat(buf, ",", sizeof buf);
1669: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1670: }
1671: }
1672: if (buf[0] == '\0')
1673: strlcpy(buf, "notty", sizeof buf);
1674: return buf;
1675: }
1676:
1677: void
1678: session_proctitle(Session *s)
1679: {
1680: if (s->pw == NULL)
1681: error("no user for session %d", s->self);
1682: else
1683: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1684: }
1685:
1686: void
1.49 markus 1687: do_authenticated2(Authctxt *authctxt)
1.2 markus 1688: {
1689: /*
1690: * Cancel the alarm we set to limit the time taken for
1691: * authentication.
1692: */
1693: alarm(0);
1.23 deraadt 1694: if (startup_pipe != -1) {
1695: close(startup_pipe);
1696: startup_pipe = -1;
1697: }
1.61 markus 1698: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
1699: channel_permit_all_opens();
1.28 millert 1700: #ifdef HAVE_LOGIN_CAP
1.49 markus 1701: if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
1.28 millert 1702: error("unable to get login class");
1703: return;
1704: }
1705: #endif
1.2 markus 1706: server_loop2();
1.7 markus 1707: if (xauthfile)
1708: xauthfile_cleanup_proc(NULL);
1.1 markus 1709: }
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