Annotation of src/usr.bin/ssh/session.c, Revision 1.38
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.
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"
1.38 ! markus 36: RCSID("$OpenBSD: session.c,v 1.37 2000/09/07 20:27:53 deraadt Exp $");
1.1 markus 37:
38: #include "xmalloc.h"
39: #include "ssh.h"
40: #include "pty.h"
41: #include "packet.h"
42: #include "buffer.h"
43: #include "mpaux.h"
44: #include "servconf.h"
45: #include "uidswap.h"
46: #include "compat.h"
47: #include "channels.h"
48: #include "nchan.h"
49:
1.2 markus 50: #include "bufaux.h"
51: #include "ssh2.h"
52: #include "auth.h"
1.19 markus 53: #include "auth-options.h"
1.2 markus 54:
1.28 millert 55: #ifdef HAVE_LOGIN_CAP
56: #include <login_cap.h>
57: #endif
58:
1.1 markus 59: /* types */
60:
61: #define TTYSZ 64
62: typedef struct Session Session;
63: struct Session {
64: int used;
65: int self;
1.7 markus 66: int extended;
1.1 markus 67: struct passwd *pw;
68: pid_t pid;
69: /* tty */
70: char *term;
71: int ptyfd, ttyfd, ptymaster;
72: int row, col, xpixel, ypixel;
73: char tty[TTYSZ];
74: /* X11 */
75: char *display;
76: int screen;
77: char *auth_proto;
78: char *auth_data;
1.7 markus 79: int single_connection;
1.1 markus 80: /* proto 2 */
81: int chanid;
82: };
83:
84: /* func */
85:
86: Session *session_new(void);
87: void session_set_fds(Session *s, int fdin, int fdout, int fderr);
88: void session_pty_cleanup(Session *s);
1.9 markus 89: void session_proctitle(Session *s);
1.1 markus 90: void do_exec_pty(Session *s, const char *command, struct passwd * pw);
91: void do_exec_no_pty(Session *s, const char *command, struct passwd * pw);
1.24 markus 92: void do_login(Session *s);
1.1 markus 93:
94: void
95: do_child(const char *command, struct passwd * pw, const char *term,
96: const char *display, const char *auth_proto,
97: const char *auth_data, const char *ttyname);
98:
99: /* import */
100: extern ServerOptions options;
101: extern char *__progname;
102: extern int log_stderr;
103: extern int debug_flag;
1.25 markus 104: extern unsigned int utmp_len;
1.1 markus 105:
1.21 markus 106: extern int startup_pipe;
107:
1.1 markus 108: /* Local Xauthority file. */
109: static char *xauthfile;
110:
1.34 markus 111: /* original command from peer. */
112: char *original_command = NULL;
113:
1.1 markus 114: /* data */
115: #define MAX_SESSIONS 10
116: Session sessions[MAX_SESSIONS];
117:
1.28 millert 118: #ifdef HAVE_LOGIN_CAP
119: static login_cap_t *lc;
120: #endif
121:
1.1 markus 122: /*
123: * Remove local Xauthority file.
124: */
125: void
126: xauthfile_cleanup_proc(void *ignore)
127: {
128: debug("xauthfile_cleanup_proc called");
129:
130: if (xauthfile != NULL) {
131: char *p;
132: unlink(xauthfile);
133: p = strrchr(xauthfile, '/');
134: if (p != NULL) {
135: *p = '\0';
136: rmdir(xauthfile);
137: }
138: xfree(xauthfile);
139: xauthfile = NULL;
140: }
141: }
142:
143: /*
144: * Function to perform cleanup if we get aborted abnormally (e.g., due to a
145: * dropped connection).
146: */
1.4 markus 147: void
1.1 markus 148: pty_cleanup_proc(void *session)
149: {
150: Session *s=session;
151: if (s == NULL)
152: fatal("pty_cleanup_proc: no session");
153: debug("pty_cleanup_proc: %s", s->tty);
154:
155: if (s->pid != 0) {
156: /* Record that the user has logged out. */
157: record_logout(s->pid, s->tty);
158: }
159:
160: /* Release the pseudo-tty. */
161: pty_release(s->tty);
162: }
163:
164: /*
165: * Prepares for an interactive session. This is called after the user has
166: * been successfully authenticated. During this message exchange, pseudo
167: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
168: * are requested, etc.
169: */
1.4 markus 170: void
1.1 markus 171: do_authenticated(struct passwd * pw)
172: {
173: Session *s;
1.33 markus 174: int type, fd;
1.1 markus 175: int compression_level = 0, enable_compression_after_reply = 0;
176: int have_pty = 0;
177: char *command;
178: int n_bytes;
179: int plen;
180: unsigned int proto_len, data_len, dlen;
181:
182: /*
183: * Cancel the alarm we set to limit the time taken for
184: * authentication.
185: */
186: alarm(0);
1.23 deraadt 187: if (startup_pipe != -1) {
188: close(startup_pipe);
189: startup_pipe = -1;
190: }
1.1 markus 191:
192: /*
193: * Inform the channel mechanism that we are the server side and that
194: * the client may request to connect to any port at all. (The user
195: * could do it anyway, and we wouldn\'t know what is permitted except
196: * by the client telling us, so we can equally well trust the client
197: * not to request anything bogus.)
198: */
199: if (!no_port_forwarding_flag)
200: channel_permit_all_opens();
201:
202: s = session_new();
1.7 markus 203: s->pw = pw;
1.1 markus 204:
1.28 millert 205: #ifdef HAVE_LOGIN_CAP
206: if ((lc = login_getclass(pw->pw_class)) == NULL) {
207: error("unable to get login class");
208: return;
209: }
210: #endif
211:
1.1 markus 212: /*
213: * We stay in this loop until the client requests to execute a shell
214: * or a command.
215: */
216: for (;;) {
217: int success = 0;
218:
219: /* Get a packet from the client. */
220: type = packet_read(&plen);
221:
222: /* Process the packet. */
223: switch (type) {
224: case SSH_CMSG_REQUEST_COMPRESSION:
225: packet_integrity_check(plen, 4, type);
226: compression_level = packet_get_int();
227: if (compression_level < 1 || compression_level > 9) {
228: packet_send_debug("Received illegal compression level %d.",
229: compression_level);
230: break;
231: }
232: /* Enable compression after we have responded with SUCCESS. */
233: enable_compression_after_reply = 1;
234: success = 1;
235: break;
236:
237: case SSH_CMSG_REQUEST_PTY:
238: if (no_pty_flag) {
239: debug("Allocating a pty not permitted for this authentication.");
240: break;
241: }
242: if (have_pty)
243: packet_disconnect("Protocol error: you already have a pty.");
244:
245: debug("Allocating pty.");
246:
247: /* Allocate a pty and open it. */
248: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
249: sizeof(s->tty))) {
250: error("Failed to allocate pty.");
251: break;
252: }
253: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
254: pty_setowner(pw, s->tty);
255:
256: /* Get TERM from the packet. Note that the value may be of arbitrary length. */
257: s->term = packet_get_string(&dlen);
258: packet_integrity_check(dlen, strlen(s->term), type);
259: /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
260: /* Remaining bytes */
261: n_bytes = plen - (4 + dlen + 4 * 4);
262:
263: if (strcmp(s->term, "") == 0) {
264: xfree(s->term);
265: s->term = NULL;
266: }
267: /* Get window size from the packet. */
268: s->row = packet_get_int();
269: s->col = packet_get_int();
270: s->xpixel = packet_get_int();
271: s->ypixel = packet_get_int();
272: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
273:
274: /* Get tty modes from the packet. */
275: tty_parse_modes(s->ttyfd, &n_bytes);
276: packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
1.10 markus 277:
278: session_proctitle(s);
1.1 markus 279:
280: /* Indicate that we now have a pty. */
281: success = 1;
282: have_pty = 1;
283: break;
284:
285: case SSH_CMSG_X11_REQUEST_FORWARDING:
286: if (!options.x11_forwarding) {
287: packet_send_debug("X11 forwarding disabled in server configuration file.");
288: break;
289: }
1.16 markus 290: if (!options.xauth_location) {
291: packet_send_debug("No xauth program; cannot forward with spoofing.");
292: break;
293: }
1.1 markus 294: if (no_x11_forwarding_flag) {
295: packet_send_debug("X11 forwarding not permitted for this authentication.");
296: break;
297: }
298: debug("Received request for X11 forwarding with auth spoofing.");
299: if (s->display != NULL)
300: packet_disconnect("Protocol error: X11 display already set.");
301:
302: s->auth_proto = packet_get_string(&proto_len);
303: s->auth_data = packet_get_string(&data_len);
304: packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type);
305:
306: if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER)
307: s->screen = packet_get_int();
308: else
309: s->screen = 0;
310: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
311:
312: if (s->display == NULL)
313: break;
314:
315: /* Setup to always have a local .Xauthority. */
316: xauthfile = xmalloc(MAXPATHLEN);
317: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
318: temporarily_use_uid(pw->pw_uid);
319: if (mkdtemp(xauthfile) == NULL) {
320: restore_uid();
321: error("private X11 dir: mkdtemp %s failed: %s",
322: xauthfile, strerror(errno));
323: xfree(xauthfile);
324: xauthfile = NULL;
1.7 markus 325: /* XXXX remove listening channels */
1.1 markus 326: break;
327: }
328: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 329: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
330: if (fd >= 0)
331: close(fd);
1.1 markus 332: restore_uid();
333: fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
334: success = 1;
335: break;
336:
337: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
338: if (no_agent_forwarding_flag || compat13) {
339: debug("Authentication agent forwarding not permitted for this authentication.");
340: break;
341: }
342: debug("Received authentication agent forwarding request.");
1.15 markus 343: success = auth_input_request_forwarding(pw);
1.1 markus 344: break;
345:
346: case SSH_CMSG_PORT_FORWARD_REQUEST:
347: if (no_port_forwarding_flag) {
348: debug("Port forwarding not permitted for this authentication.");
349: break;
350: }
351: debug("Received TCP/IP port forwarding request.");
1.12 markus 352: channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
1.1 markus 353: success = 1;
354: break;
355:
356: case SSH_CMSG_MAX_PACKET_SIZE:
357: if (packet_set_maxsize(packet_get_int()) > 0)
358: success = 1;
359: break;
360:
361: case SSH_CMSG_EXEC_SHELL:
362: case SSH_CMSG_EXEC_CMD:
363: /* Set interactive/non-interactive mode. */
364: packet_set_interactive(have_pty || s->display != NULL,
365: options.keepalives);
366:
367: if (type == SSH_CMSG_EXEC_CMD) {
368: command = packet_get_string(&dlen);
369: debug("Exec command '%.500s'", command);
370: packet_integrity_check(plen, 4 + dlen, type);
371: } else {
372: command = NULL;
373: packet_integrity_check(plen, 0, type);
374: }
375: if (forced_command != NULL) {
1.34 markus 376: original_command = command;
1.1 markus 377: command = forced_command;
378: debug("Forced command '%.500s'", forced_command);
379: }
380: if (have_pty)
381: do_exec_pty(s, command, pw);
382: else
383: do_exec_no_pty(s, command, pw);
384:
385: if (command != NULL)
386: xfree(command);
387: /* Cleanup user's local Xauthority file. */
388: if (xauthfile)
389: xauthfile_cleanup_proc(NULL);
390: return;
391:
392: default:
393: /*
394: * Any unknown messages in this phase are ignored,
395: * and a failure message is returned.
396: */
397: log("Unknown packet type received after authentication: %d", type);
398: }
399: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
400: packet_send();
401: packet_write_wait();
402:
403: /* Enable compression now that we have replied if appropriate. */
404: if (enable_compression_after_reply) {
405: enable_compression_after_reply = 0;
406: packet_start_compression(compression_level);
407: }
408: }
409: }
410:
411: /*
412: * This is called to fork and execute a command when we have no tty. This
413: * will call do_child from the child, and server_loop from the parent after
414: * setting up file descriptors and such.
415: */
1.4 markus 416: void
1.1 markus 417: do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
418: {
419: int pid;
420:
421: #ifdef USE_PIPES
422: int pin[2], pout[2], perr[2];
423: /* Allocate pipes for communicating with the program. */
424: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
425: packet_disconnect("Could not create pipes: %.100s",
426: strerror(errno));
427: #else /* USE_PIPES */
428: int inout[2], err[2];
429: /* Uses socket pairs to communicate with the program. */
430: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
431: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
432: packet_disconnect("Could not create socket pairs: %.100s",
433: strerror(errno));
434: #endif /* USE_PIPES */
435: if (s == NULL)
436: fatal("do_exec_no_pty: no session");
437:
1.9 markus 438: session_proctitle(s);
1.1 markus 439:
440: /* Fork the child. */
441: if ((pid = fork()) == 0) {
442: /* Child. Reinitialize the log since the pid has changed. */
443: log_init(__progname, options.log_level, options.log_facility, log_stderr);
444:
445: /*
446: * Create a new session and process group since the 4.4BSD
447: * setlogin() affects the entire process group.
448: */
449: if (setsid() < 0)
450: error("setsid failed: %.100s", strerror(errno));
451:
452: #ifdef USE_PIPES
453: /*
454: * Redirect stdin. We close the parent side of the socket
455: * pair, and make the child side the standard input.
456: */
457: close(pin[1]);
458: if (dup2(pin[0], 0) < 0)
459: perror("dup2 stdin");
460: close(pin[0]);
461:
462: /* Redirect stdout. */
463: close(pout[0]);
464: if (dup2(pout[1], 1) < 0)
465: perror("dup2 stdout");
466: close(pout[1]);
467:
468: /* Redirect stderr. */
469: close(perr[0]);
470: if (dup2(perr[1], 2) < 0)
471: perror("dup2 stderr");
472: close(perr[1]);
473: #else /* USE_PIPES */
474: /*
475: * Redirect stdin, stdout, and stderr. Stdin and stdout will
476: * use the same socket, as some programs (particularly rdist)
477: * seem to depend on it.
478: */
479: close(inout[1]);
480: close(err[1]);
481: if (dup2(inout[0], 0) < 0) /* stdin */
482: perror("dup2 stdin");
483: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
484: perror("dup2 stdout");
485: if (dup2(err[0], 2) < 0) /* stderr */
486: perror("dup2 stderr");
487: #endif /* USE_PIPES */
488:
489: /* Do processing for the child (exec command etc). */
490: do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL);
491: /* NOTREACHED */
492: }
493: if (pid < 0)
494: packet_disconnect("fork failed: %.100s", strerror(errno));
495: s->pid = pid;
496: #ifdef USE_PIPES
497: /* We are the parent. Close the child sides of the pipes. */
498: close(pin[0]);
499: close(pout[1]);
500: close(perr[1]);
501:
1.2 markus 502: if (compat20) {
1.7 markus 503: session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
1.2 markus 504: } else {
505: /* Enter the interactive session. */
506: server_loop(pid, pin[1], pout[0], perr[0]);
507: /* server_loop has closed pin[1], pout[1], and perr[1]. */
508: }
1.1 markus 509: #else /* USE_PIPES */
510: /* We are the parent. Close the child sides of the socket pairs. */
511: close(inout[0]);
512: close(err[0]);
513:
514: /*
515: * Enter the interactive session. Note: server_loop must be able to
516: * handle the case that fdin and fdout are the same.
517: */
1.2 markus 518: if (compat20) {
1.7 markus 519: session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
1.2 markus 520: } else {
521: server_loop(pid, inout[1], inout[1], err[1]);
522: /* server_loop has closed inout[1] and err[1]. */
523: }
1.1 markus 524: #endif /* USE_PIPES */
525: }
526:
527: /*
528: * This is called to fork and execute a command when we have a tty. This
529: * will call do_child from the child, and server_loop from the parent after
530: * setting up file descriptors, controlling tty, updating wtmp, utmp,
531: * lastlog, and other such operations.
532: */
1.4 markus 533: void
1.1 markus 534: do_exec_pty(Session *s, const char *command, struct passwd * pw)
535: {
536: int fdout, ptyfd, ttyfd, ptymaster;
537: pid_t pid;
538:
539: if (s == NULL)
540: fatal("do_exec_pty: no session");
541: ptyfd = s->ptyfd;
542: ttyfd = s->ttyfd;
543:
544: /* Fork the child. */
545: if ((pid = fork()) == 0) {
1.24 markus 546: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 547: log_init(__progname, options.log_level, options.log_facility, log_stderr);
548:
549: /* Close the master side of the pseudo tty. */
550: close(ptyfd);
551:
552: /* Make the pseudo tty our controlling tty. */
553: pty_make_controlling_tty(&ttyfd, s->tty);
554:
555: /* Redirect stdin from the pseudo tty. */
556: if (dup2(ttyfd, fileno(stdin)) < 0)
557: error("dup2 stdin failed: %.100s", strerror(errno));
558:
559: /* Redirect stdout to the pseudo tty. */
560: if (dup2(ttyfd, fileno(stdout)) < 0)
561: error("dup2 stdin failed: %.100s", strerror(errno));
562:
563: /* Redirect stderr to the pseudo tty. */
564: if (dup2(ttyfd, fileno(stderr)) < 0)
565: error("dup2 stdin failed: %.100s", strerror(errno));
566:
567: /* Close the extra descriptor for the pseudo tty. */
568: close(ttyfd);
569:
1.24 markus 570: /* record login, etc. similar to login(1) */
571: if (command == NULL && !options.use_login)
572: do_login(s);
1.1 markus 573:
574: /* Do common processing for the child, such as execing the command. */
1.14 deraadt 575: do_child(command, pw, s->term, s->display, s->auth_proto,
576: s->auth_data, s->tty);
1.1 markus 577: /* NOTREACHED */
578: }
579: if (pid < 0)
580: packet_disconnect("fork failed: %.100s", strerror(errno));
581: s->pid = pid;
582:
583: /* Parent. Close the slave side of the pseudo tty. */
584: close(ttyfd);
585:
586: /*
587: * Create another descriptor of the pty master side for use as the
588: * standard input. We could use the original descriptor, but this
589: * simplifies code in server_loop. The descriptor is bidirectional.
590: */
591: fdout = dup(ptyfd);
592: if (fdout < 0)
593: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
594:
595: /* we keep a reference to the pty master */
596: ptymaster = dup(ptyfd);
597: if (ptymaster < 0)
598: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
599: s->ptymaster = ptymaster;
600:
601: /* Enter interactive session. */
1.2 markus 602: if (compat20) {
603: session_set_fds(s, ptyfd, fdout, -1);
604: } else {
605: server_loop(pid, ptyfd, fdout, -1);
606: /* server_loop _has_ closed ptyfd and fdout. */
607: session_pty_cleanup(s);
1.24 markus 608: }
609: }
610:
1.25 markus 611: const char *
612: get_remote_name_or_ip(void)
613: {
614: static const char *remote = "";
615: if (utmp_len > 0)
616: remote = get_canonical_hostname();
617: if (utmp_len == 0 || strlen(remote) > utmp_len)
618: remote = get_remote_ipaddr();
619: return remote;
620: }
621:
1.24 markus 622: /* administrative, login(1)-like work */
623: void
624: do_login(Session *s)
625: {
626: FILE *f;
627: char *time_string;
628: char buf[256];
1.35 markus 629: char hostname[MAXHOSTNAMELEN];
1.24 markus 630: socklen_t fromlen;
631: struct sockaddr_storage from;
632: struct stat st;
633: time_t last_login_time;
634: struct passwd * pw = s->pw;
635: pid_t pid = getpid();
636:
637: /*
638: * Get IP address of client. If the connection is not a socket, let
639: * the address be 0.0.0.0.
640: */
641: memset(&from, 0, sizeof(from));
642: if (packet_connection_is_on_socket()) {
643: fromlen = sizeof(from);
644: if (getpeername(packet_get_connection_in(),
645: (struct sockaddr *) & from, &fromlen) < 0) {
646: debug("getpeername: %.100s", strerror(errno));
647: fatal_cleanup();
648: }
649: }
1.25 markus 650:
1.35 markus 651: /* Get the time and hostname when the user last logged in. */
1.36 markus 652: hostname[0] = '\0';
1.35 markus 653: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
654: hostname, sizeof(hostname));
655:
1.24 markus 656: /* Record that there was a login on that tty from the remote host. */
657: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.25 markus 658: get_remote_name_or_ip(), (struct sockaddr *)&from);
1.24 markus 659:
660: /* Done if .hushlogin exists. */
661: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
1.28 millert 662: #ifdef HAVE_LOGIN_CAP
663: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
664: #else
1.24 markus 665: if (stat(buf, &st) >= 0)
1.28 millert 666: #endif
1.24 markus 667: return;
668: if (last_login_time != 0) {
669: time_string = ctime(&last_login_time);
670: if (strchr(time_string, '\n'))
671: *strchr(time_string, '\n') = 0;
672: if (strcmp(buf, "") == 0)
673: printf("Last login: %s\r\n", time_string);
674: else
1.36 markus 675: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 676: }
677: if (options.print_motd) {
1.28 millert 678: #ifdef HAVE_LOGIN_CAP
679: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
680: "/etc/motd"), "r");
681: #else
1.24 markus 682: f = fopen("/etc/motd", "r");
1.28 millert 683: #endif
1.24 markus 684: if (f) {
685: while (fgets(buf, sizeof(buf), f))
686: fputs(buf, stdout);
687: fclose(f);
688: }
1.2 markus 689: }
1.1 markus 690: }
691:
692: /*
693: * Sets the value of the given variable in the environment. If the variable
694: * already exists, its value is overriden.
695: */
1.4 markus 696: void
1.1 markus 697: child_set_env(char ***envp, unsigned int *envsizep, const char *name,
698: const char *value)
699: {
700: unsigned int i, namelen;
701: char **env;
702:
703: /*
704: * Find the slot where the value should be stored. If the variable
705: * already exists, we reuse the slot; otherwise we append a new slot
706: * at the end of the array, expanding if necessary.
707: */
708: env = *envp;
709: namelen = strlen(name);
710: for (i = 0; env[i]; i++)
711: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
712: break;
713: if (env[i]) {
714: /* Reuse the slot. */
715: xfree(env[i]);
716: } else {
717: /* New variable. Expand if necessary. */
718: if (i >= (*envsizep) - 1) {
719: (*envsizep) += 50;
720: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
721: }
722: /* Need to set the NULL pointer at end of array beyond the new slot. */
723: env[i + 1] = NULL;
724: }
725:
726: /* Allocate space and format the variable in the appropriate slot. */
727: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
728: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
729: }
730:
731: /*
732: * Reads environment variables from the given file and adds/overrides them
733: * into the environment. If the file does not exist, this does nothing.
734: * Otherwise, it must consist of empty lines, comments (line starts with '#')
735: * and assignments of the form name=value. No other forms are allowed.
736: */
1.4 markus 737: void
1.1 markus 738: read_environment_file(char ***env, unsigned int *envsize,
739: const char *filename)
740: {
741: FILE *f;
742: char buf[4096];
743: char *cp, *value;
744:
745: f = fopen(filename, "r");
746: if (!f)
747: return;
748:
749: while (fgets(buf, sizeof(buf), f)) {
750: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
751: ;
752: if (!*cp || *cp == '#' || *cp == '\n')
753: continue;
754: if (strchr(cp, '\n'))
755: *strchr(cp, '\n') = '\0';
756: value = strchr(cp, '=');
757: if (value == NULL) {
758: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
759: continue;
760: }
1.14 deraadt 761: /*
762: * Replace the equals sign by nul, and advance value to
763: * the value string.
764: */
1.1 markus 765: *value = '\0';
766: value++;
767: child_set_env(env, envsize, cp, value);
768: }
769: fclose(f);
770: }
771:
772: /*
773: * Performs common processing for the child, such as setting up the
774: * environment, closing extra file descriptors, setting the user and group
775: * ids, and executing the command or shell.
776: */
1.4 markus 777: void
1.1 markus 778: do_child(const char *command, struct passwd * pw, const char *term,
779: const char *display, const char *auth_proto,
780: const char *auth_data, const char *ttyname)
781: {
1.32 markus 782: const char *shell, *hostname = NULL, *cp = NULL;
1.1 markus 783: char buf[256];
1.16 markus 784: char cmd[1024];
1.27 millert 785: FILE *f = NULL;
1.1 markus 786: unsigned int envsize, i;
787: char **env;
788: extern char **environ;
789: struct stat st;
790: char *argv[10];
1.17 markus 791:
792: /* login(1) is only called if we execute the login shell */
793: if (options.use_login && command != NULL)
794: options.use_login = 0;
1.1 markus 795:
1.27 millert 796: if (!options.use_login) {
1.28 millert 797: #ifdef HAVE_LOGIN_CAP
798: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
799: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
800: _PATH_NOLOGIN), "r");
801: #else
1.27 millert 802: if (pw->pw_uid)
803: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 804: #endif
1.27 millert 805: if (f) {
806: /* /etc/nologin exists. Print its contents and exit. */
807: while (fgets(buf, sizeof(buf), f))
808: fputs(buf, stderr);
809: fclose(f);
1.1 markus 810: exit(254);
1.27 millert 811: }
1.1 markus 812: }
1.28 millert 813: /* Set login name, uid, gid, and groups. */
1.1 markus 814: /* Login(1) does this as well, and it needs uid 0 for the "-h"
815: switch, so we let login(1) to this for us. */
816: if (!options.use_login) {
817: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 818: #ifdef HAVE_LOGIN_CAP
819: if (setusercontext(lc, pw, pw->pw_uid,
820: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
821: perror("unable to set user context");
822: exit(1);
823:
824: }
825: #else
826: if (setlogin(pw->pw_name) < 0)
827: error("setlogin failed: %s", strerror(errno));
1.1 markus 828: if (setgid(pw->pw_gid) < 0) {
829: perror("setgid");
830: exit(1);
831: }
832: /* Initialize the group list. */
833: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
834: perror("initgroups");
835: exit(1);
836: }
837: endgrent();
838:
839: /* Permanently switch to the desired uid. */
840: permanently_set_uid(pw->pw_uid);
1.28 millert 841: #endif
1.1 markus 842: }
843: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 844: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 845: }
846: /*
847: * Get the shell from the password data. An empty shell field is
848: * legal, and means /bin/sh.
849: */
850: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 851: #ifdef HAVE_LOGIN_CAP
852: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
853: #endif
1.1 markus 854:
855: #ifdef AFS
856: /* Try to get AFS tokens for the local cell. */
857: if (k_hasafs()) {
858: char cell[64];
859:
860: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
861: krb_afslog(cell, 0);
862:
863: krb_afslog(0, 0);
864: }
865: #endif /* AFS */
866:
867: /* Initialize the environment. */
868: envsize = 100;
869: env = xmalloc(envsize * sizeof(char *));
870: env[0] = NULL;
871:
872: if (!options.use_login) {
873: /* Set basic environment. */
874: child_set_env(&env, &envsize, "USER", pw->pw_name);
875: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
876: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 877: #ifdef HAVE_LOGIN_CAP
1.29 millert 878: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
879: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 880: #else
1.29 millert 881: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 882: #endif
1.1 markus 883:
884: snprintf(buf, sizeof buf, "%.200s/%.50s",
885: _PATH_MAILDIR, pw->pw_name);
886: child_set_env(&env, &envsize, "MAIL", buf);
887:
888: /* Normal systems set SHELL by default. */
889: child_set_env(&env, &envsize, "SHELL", shell);
890: }
891: if (getenv("TZ"))
892: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
893:
894: /* Set custom environment options from RSA authentication. */
895: while (custom_environment) {
896: struct envstring *ce = custom_environment;
897: char *s = ce->s;
898: int i;
899: for (i = 0; s[i] != '=' && s[i]; i++);
900: if (s[i] == '=') {
901: s[i] = 0;
902: child_set_env(&env, &envsize, s, s + i + 1);
903: }
904: custom_environment = ce->next;
905: xfree(ce->s);
906: xfree(ce);
907: }
908:
909: snprintf(buf, sizeof buf, "%.50s %d %d",
910: get_remote_ipaddr(), get_remote_port(), get_local_port());
911: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
912:
913: if (ttyname)
914: child_set_env(&env, &envsize, "SSH_TTY", ttyname);
915: if (term)
916: child_set_env(&env, &envsize, "TERM", term);
917: if (display)
918: child_set_env(&env, &envsize, "DISPLAY", display);
1.34 markus 919: if (original_command)
920: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
921: original_command);
1.1 markus 922:
923: #ifdef KRB4
924: {
925: extern char *ticket;
926:
927: if (ticket)
928: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
929: }
930: #endif /* KRB4 */
931:
932: if (xauthfile)
933: child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
934: if (auth_get_socket_name() != NULL)
935: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
936: auth_get_socket_name());
937:
938: /* read $HOME/.ssh/environment. */
939: if (!options.use_login) {
1.14 deraadt 940: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
941: pw->pw_dir);
1.1 markus 942: read_environment_file(&env, &envsize, buf);
943: }
944: if (debug_flag) {
945: /* dump the environment */
946: fprintf(stderr, "Environment:\n");
947: for (i = 0; env[i]; i++)
948: fprintf(stderr, " %.200s\n", env[i]);
949: }
1.26 millert 950: /* we have to stash the hostname before we close our socket. */
951: if (options.use_login)
952: hostname = get_remote_name_or_ip();
1.1 markus 953: /*
954: * Close the connection descriptors; note that this is the child, and
955: * the server will still have the socket open, and it is important
956: * that we do not shutdown it. Note that the descriptors cannot be
957: * closed before building the environment, as we call
958: * get_remote_ipaddr there.
959: */
960: if (packet_get_connection_in() == packet_get_connection_out())
961: close(packet_get_connection_in());
962: else {
963: close(packet_get_connection_in());
964: close(packet_get_connection_out());
965: }
966: /*
967: * Close all descriptors related to channels. They will still remain
968: * open in the parent.
969: */
970: /* XXX better use close-on-exec? -markus */
971: channel_close_all();
972:
973: /*
974: * Close any extra file descriptors. Note that there may still be
975: * descriptors left by system functions. They will be closed later.
976: */
977: endpwent();
978:
979: /*
980: * Close any extra open file descriptors so that we don\'t have them
981: * hanging around in clients. Note that we want to do this after
982: * initgroups, because at least on Solaris 2.3 it leaves file
983: * descriptors open.
984: */
985: for (i = 3; i < 64; i++)
986: close(i);
987:
988: /* Change current directory to the user\'s home directory. */
1.28 millert 989: if (chdir(pw->pw_dir) < 0) {
1.1 markus 990: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
991: pw->pw_dir, strerror(errno));
1.28 millert 992: #ifdef HAVE_LOGIN_CAP
993: if (login_getcapbool(lc, "requirehome", 0))
994: exit(1);
995: #endif
996: }
1.1 markus 997:
998: /*
999: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1000: * xauth are run in the proper environment.
1001: */
1002: environ = env;
1003:
1004: /*
1005: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1006: * in this order).
1007: */
1008: if (!options.use_login) {
1009: if (stat(SSH_USER_RC, &st) >= 0) {
1010: if (debug_flag)
1011: fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC);
1012:
1013: f = popen("/bin/sh " SSH_USER_RC, "w");
1014: if (f) {
1015: if (auth_proto != NULL && auth_data != NULL)
1016: fprintf(f, "%s %s\n", auth_proto, auth_data);
1017: pclose(f);
1018: } else
1019: fprintf(stderr, "Could not run %s\n", SSH_USER_RC);
1020: } else if (stat(SSH_SYSTEM_RC, &st) >= 0) {
1021: if (debug_flag)
1022: fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC);
1023:
1024: f = popen("/bin/sh " SSH_SYSTEM_RC, "w");
1025: if (f) {
1026: if (auth_proto != NULL && auth_data != NULL)
1027: fprintf(f, "%s %s\n", auth_proto, auth_data);
1028: pclose(f);
1029: } else
1030: fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC);
1.16 markus 1031: } else if (options.xauth_location != NULL) {
1.1 markus 1032: /* Add authority data to .Xauthority if appropriate. */
1033: if (auth_proto != NULL && auth_data != NULL) {
1.13 markus 1034: char *screen = strchr(display, ':');
1035: if (debug_flag) {
1.14 deraadt 1036: fprintf(stderr,
1037: "Running %.100s add %.100s %.100s %.100s\n",
1.16 markus 1038: options.xauth_location, display,
1039: auth_proto, auth_data);
1.13 markus 1040: if (screen != NULL)
1.14 deraadt 1041: fprintf(stderr,
1042: "Adding %.*s/unix%s %s %s\n",
1.30 deraadt 1043: (int)(screen-display), display,
1.14 deraadt 1044: screen, auth_proto, auth_data);
1.13 markus 1045: }
1.16 markus 1046: snprintf(cmd, sizeof cmd, "%s -q -",
1047: options.xauth_location);
1048: f = popen(cmd, "w");
1.1 markus 1049: if (f) {
1.14 deraadt 1050: fprintf(f, "add %s %s %s\n", display,
1051: auth_proto, auth_data);
1.13 markus 1052: if (screen != NULL)
1053: fprintf(f, "add %.*s/unix%s %s %s\n",
1.30 deraadt 1054: (int)(screen-display), display,
1.14 deraadt 1055: screen, auth_proto, auth_data);
1.1 markus 1056: pclose(f);
1.16 markus 1057: } else {
1058: fprintf(stderr, "Could not run %s\n",
1059: cmd);
1060: }
1.1 markus 1061: }
1062: }
1063: /* Get the last component of the shell name. */
1064: cp = strrchr(shell, '/');
1065: if (cp)
1066: cp++;
1067: else
1068: cp = shell;
1069: }
1070: /*
1071: * If we have no command, execute the shell. In this case, the shell
1072: * name to be passed in argv[0] is preceded by '-' to indicate that
1073: * this is a login shell.
1074: */
1075: if (!command) {
1076: if (!options.use_login) {
1077: char buf[256];
1078:
1079: /*
1080: * Check for mail if we have a tty and it was enabled
1081: * in server options.
1082: */
1083: if (ttyname && options.check_mail) {
1084: char *mailbox;
1085: struct stat mailstat;
1086: mailbox = getenv("MAIL");
1087: if (mailbox != NULL) {
1.14 deraadt 1088: if (stat(mailbox, &mailstat) != 0 ||
1089: mailstat.st_size == 0)
1.1 markus 1090: printf("No mail.\n");
1091: else if (mailstat.st_mtime < mailstat.st_atime)
1092: printf("You have mail.\n");
1093: else
1094: printf("You have new mail.\n");
1095: }
1096: }
1097: /* Start the shell. Set initial character to '-'. */
1098: buf[0] = '-';
1099: strncpy(buf + 1, cp, sizeof(buf) - 1);
1100: buf[sizeof(buf) - 1] = 0;
1101:
1102: /* Execute the shell. */
1103: argv[0] = buf;
1104: argv[1] = NULL;
1105: execve(shell, argv, env);
1106:
1107: /* Executing the shell failed. */
1108: perror(shell);
1109: exit(1);
1110:
1111: } else {
1112: /* Launch login(1). */
1113:
1.26 millert 1114: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1115: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1116:
1117: /* Login couldn't be executed, die. */
1118:
1119: perror("login");
1120: exit(1);
1121: }
1122: }
1123: /*
1124: * Execute the command using the user's shell. This uses the -c
1125: * option to execute the command.
1126: */
1127: argv[0] = (char *) cp;
1128: argv[1] = "-c";
1129: argv[2] = (char *) command;
1130: argv[3] = NULL;
1131: execve(shell, argv, env);
1132: perror(shell);
1133: exit(1);
1134: }
1135:
1136: Session *
1137: session_new(void)
1138: {
1139: int i;
1140: static int did_init = 0;
1141: if (!did_init) {
1142: debug("session_new: init");
1143: for(i = 0; i < MAX_SESSIONS; i++) {
1144: sessions[i].used = 0;
1145: sessions[i].self = i;
1146: }
1147: did_init = 1;
1148: }
1149: for(i = 0; i < MAX_SESSIONS; i++) {
1150: Session *s = &sessions[i];
1151: if (! s->used) {
1152: s->pid = 0;
1.7 markus 1153: s->extended = 0;
1.1 markus 1154: s->chanid = -1;
1155: s->ptyfd = -1;
1156: s->ttyfd = -1;
1157: s->term = NULL;
1158: s->pw = NULL;
1159: s->display = NULL;
1160: s->screen = 0;
1161: s->auth_data = NULL;
1162: s->auth_proto = NULL;
1163: s->used = 1;
1.7 markus 1164: s->pw = NULL;
1.1 markus 1165: debug("session_new: session %d", i);
1166: return s;
1167: }
1168: }
1169: return NULL;
1170: }
1171:
1172: void
1173: session_dump(void)
1174: {
1175: int i;
1176: for(i = 0; i < MAX_SESSIONS; i++) {
1177: Session *s = &sessions[i];
1178: debug("dump: used %d session %d %p channel %d pid %d",
1179: s->used,
1180: s->self,
1181: s,
1182: s->chanid,
1183: s->pid);
1184: }
1185: }
1186:
1.2 markus 1187: int
1188: session_open(int chanid)
1189: {
1190: Session *s = session_new();
1191: debug("session_open: channel %d", chanid);
1192: if (s == NULL) {
1193: error("no more sessions");
1194: return 0;
1195: }
1.7 markus 1196: s->pw = auth_get_user();
1197: if (s->pw == NULL)
1198: fatal("no user for session %i", s->self);
1.2 markus 1199: debug("session_open: session %d: link with channel %d", s->self, chanid);
1200: s->chanid = chanid;
1201: return 1;
1202: }
1203:
1204: Session *
1205: session_by_channel(int id)
1206: {
1207: int i;
1208: for(i = 0; i < MAX_SESSIONS; i++) {
1209: Session *s = &sessions[i];
1210: if (s->used && s->chanid == id) {
1211: debug("session_by_channel: session %d channel %d", i, id);
1212: return s;
1213: }
1214: }
1215: debug("session_by_channel: unknown channel %d", id);
1216: session_dump();
1217: return NULL;
1218: }
1219:
1220: Session *
1221: session_by_pid(pid_t pid)
1222: {
1223: int i;
1224: debug("session_by_pid: pid %d", pid);
1225: for(i = 0; i < MAX_SESSIONS; i++) {
1226: Session *s = &sessions[i];
1227: if (s->used && s->pid == pid)
1228: return s;
1229: }
1230: error("session_by_pid: unknown pid %d", pid);
1231: session_dump();
1232: return NULL;
1233: }
1234:
1235: int
1236: session_window_change_req(Session *s)
1237: {
1238: s->col = packet_get_int();
1239: s->row = packet_get_int();
1240: s->xpixel = packet_get_int();
1241: s->ypixel = packet_get_int();
1.3 markus 1242: packet_done();
1.2 markus 1243: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1244: return 1;
1245: }
1246:
1247: int
1248: session_pty_req(Session *s)
1249: {
1250: unsigned int len;
1.3 markus 1251: char *term_modes; /* encoded terminal modes */
1.2 markus 1252:
1.19 markus 1253: if (no_pty_flag)
1254: return 0;
1.2 markus 1255: if (s->ttyfd != -1)
1.3 markus 1256: return 0;
1.2 markus 1257: s->term = packet_get_string(&len);
1258: s->col = packet_get_int();
1259: s->row = packet_get_int();
1260: s->xpixel = packet_get_int();
1261: s->ypixel = packet_get_int();
1.3 markus 1262: term_modes = packet_get_string(&len);
1263: packet_done();
1.2 markus 1264:
1265: if (strcmp(s->term, "") == 0) {
1266: xfree(s->term);
1267: s->term = NULL;
1268: }
1269: /* Allocate a pty and open it. */
1270: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1271: xfree(s->term);
1272: s->term = NULL;
1273: s->ptyfd = -1;
1274: s->ttyfd = -1;
1275: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1276: xfree(term_modes);
1277: return 0;
1.2 markus 1278: }
1279: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1280: /*
1281: * Add a cleanup function to clear the utmp entry and record logout
1282: * time in case we call fatal() (e.g., the connection gets closed).
1283: */
1284: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1285: pty_setowner(s->pw, s->tty);
1286: /* Get window size from the packet. */
1287: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1288:
1.9 markus 1289: session_proctitle(s);
1290:
1.3 markus 1291: /* XXX parse and set terminal modes */
1292: xfree(term_modes);
1.2 markus 1293: return 1;
1294: }
1295:
1.7 markus 1296: int
1297: session_subsystem_req(Session *s)
1298: {
1299: unsigned int len;
1300: int success = 0;
1301: char *subsys = packet_get_string(&len);
1.18 jakob 1302: int i;
1.7 markus 1303:
1304: packet_done();
1305: log("subsystem request for %s", subsys);
1.18 jakob 1306:
1307: for (i = 0; i < options.num_subsystems; i++) {
1308: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1309: debug("subsystem: exec() %s", options.subsystem_command[i]);
1310: do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1311: success = 1;
1312: }
1313: }
1314:
1315: if (!success)
1316: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1317:
1318: xfree(subsys);
1319: return success;
1320: }
1321:
1322: int
1323: session_x11_req(Session *s)
1324: {
1.33 markus 1325: int fd;
1.22 deraadt 1326: if (no_x11_forwarding_flag) {
1.19 markus 1327: debug("X11 forwarding disabled in user configuration file.");
1328: return 0;
1329: }
1.7 markus 1330: if (!options.x11_forwarding) {
1331: debug("X11 forwarding disabled in server configuration file.");
1332: return 0;
1333: }
1334: if (xauthfile != NULL) {
1335: debug("X11 fwd already started.");
1336: return 0;
1337: }
1338:
1339: debug("Received request for X11 forwarding with auth spoofing.");
1340: if (s->display != NULL)
1341: packet_disconnect("Protocol error: X11 display already set.");
1342:
1343: s->single_connection = packet_get_char();
1344: s->auth_proto = packet_get_string(NULL);
1345: s->auth_data = packet_get_string(NULL);
1346: s->screen = packet_get_int();
1347: packet_done();
1348:
1349: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1350: if (s->display == NULL) {
1351: xfree(s->auth_proto);
1352: xfree(s->auth_data);
1353: return 0;
1354: }
1355: xauthfile = xmalloc(MAXPATHLEN);
1356: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1357: temporarily_use_uid(s->pw->pw_uid);
1358: if (mkdtemp(xauthfile) == NULL) {
1359: restore_uid();
1360: error("private X11 dir: mkdtemp %s failed: %s",
1361: xauthfile, strerror(errno));
1362: xfree(xauthfile);
1363: xauthfile = NULL;
1364: xfree(s->auth_proto);
1365: xfree(s->auth_data);
1366: /* XXXX remove listening channels */
1367: return 0;
1368: }
1369: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 1370: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1371: if (fd >= 0)
1372: close(fd);
1.7 markus 1373: restore_uid();
1374: fatal_add_cleanup(xauthfile_cleanup_proc, s);
1375: return 1;
1376: }
1377:
1.19 markus 1378: int
1379: session_shell_req(Session *s)
1380: {
1381: /* if forced_command == NULL, the shell is execed */
1382: char *shell = forced_command;
1383: packet_done();
1384: s->extended = 1;
1385: if (s->ttyfd == -1)
1386: do_exec_no_pty(s, shell, s->pw);
1387: else
1388: do_exec_pty(s, shell, s->pw);
1389: return 1;
1390: }
1391:
1392: int
1393: session_exec_req(Session *s)
1394: {
1.20 markus 1395: unsigned int len;
1.19 markus 1396: char *command = packet_get_string(&len);
1397: packet_done();
1398: if (forced_command) {
1.34 markus 1399: original_command = command;
1.19 markus 1400: command = forced_command;
1401: debug("Forced command '%.500s'", forced_command);
1402: }
1403: s->extended = 1;
1404: if (s->ttyfd == -1)
1405: do_exec_no_pty(s, command, s->pw);
1406: else
1407: do_exec_pty(s, command, s->pw);
1408: if (forced_command == NULL)
1409: xfree(command);
1410: return 1;
1411: }
1412:
1.2 markus 1413: void
1414: session_input_channel_req(int id, void *arg)
1415: {
1416: unsigned int len;
1417: int reply;
1418: int success = 0;
1419: char *rtype;
1420: Session *s;
1421: Channel *c;
1422:
1423: rtype = packet_get_string(&len);
1424: reply = packet_get_char();
1425:
1426: s = session_by_channel(id);
1427: if (s == NULL)
1428: fatal("session_input_channel_req: channel %d: no session", id);
1429: c = channel_lookup(id);
1430: if (c == NULL)
1431: fatal("session_input_channel_req: channel %d: bad channel", id);
1432:
1433: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1434: s->self, id, rtype, reply);
1435:
1436: /*
1437: * a session is in LARVAL state until a shell
1438: * or programm is executed
1439: */
1440: if (c->type == SSH_CHANNEL_LARVAL) {
1441: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1442: success = session_shell_req(s);
1.2 markus 1443: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1444: success = session_exec_req(s);
1.2 markus 1445: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1446: success = session_pty_req(s);
1.7 markus 1447: } else if (strcmp(rtype, "x11-req") == 0) {
1448: success = session_x11_req(s);
1449: } else if (strcmp(rtype, "subsystem") == 0) {
1450: success = session_subsystem_req(s);
1.2 markus 1451: }
1452: }
1453: if (strcmp(rtype, "window-change") == 0) {
1454: success = session_window_change_req(s);
1455: }
1456:
1457: if (reply) {
1458: packet_start(success ?
1459: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1460: packet_put_int(c->remote_id);
1461: packet_send();
1462: }
1463: xfree(rtype);
1464: }
1465:
1466: void
1467: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1468: {
1469: if (!compat20)
1470: fatal("session_set_fds: called for proto != 2.0");
1471: /*
1472: * now that have a child and a pipe to the child,
1473: * we can activate our channel and register the fd's
1474: */
1475: if (s->chanid == -1)
1476: fatal("no channel for session %d", s->self);
1477: channel_set_fds(s->chanid,
1478: fdout, fdin, fderr,
1479: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ);
1480: }
1481:
1.1 markus 1482: void
1483: session_pty_cleanup(Session *s)
1484: {
1485: if (s == NULL || s->ttyfd == -1)
1486: return;
1487:
1488: debug("session_pty_cleanup: session %i release %s", s->self, s->tty);
1489:
1490: /* Cancel the cleanup function. */
1491: fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1492:
1493: /* Record that the user has logged out. */
1494: record_logout(s->pid, s->tty);
1495:
1496: /* Release the pseudo-tty. */
1497: pty_release(s->tty);
1498:
1499: /*
1500: * Close the server side of the socket pairs. We must do this after
1501: * the pty cleanup, so that another process doesn't get this pty
1502: * while we're still cleaning up.
1503: */
1504: if (close(s->ptymaster) < 0)
1505: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1506: }
1507:
1508: void
1509: session_exit_message(Session *s, int status)
1510: {
1511: Channel *c;
1512: if (s == NULL)
1513: fatal("session_close: no session");
1514: c = channel_lookup(s->chanid);
1515: if (c == NULL)
1516: fatal("session_close: session %d: no channel %d",
1517: s->self, s->chanid);
1518: debug("session_exit_message: session %d channel %d pid %d",
1519: s->self, s->chanid, s->pid);
1520:
1521: if (WIFEXITED(status)) {
1522: channel_request_start(s->chanid,
1523: "exit-status", 0);
1524: packet_put_int(WEXITSTATUS(status));
1525: packet_send();
1526: } else if (WIFSIGNALED(status)) {
1527: channel_request_start(s->chanid,
1528: "exit-signal", 0);
1529: packet_put_int(WTERMSIG(status));
1530: packet_put_char(WCOREDUMP(status));
1531: packet_put_cstring("");
1532: packet_put_cstring("");
1533: packet_send();
1534: } else {
1535: /* Some weird exit cause. Just exit. */
1536: packet_disconnect("wait returned status %04x.", status);
1537: }
1538:
1539: /* disconnect channel */
1540: debug("session_exit_message: release channel %d", s->chanid);
1541: channel_cancel_cleanup(s->chanid);
1.5 markus 1542: /*
1543: * emulate a write failure with 'chan_write_failed', nobody will be
1544: * interested in data we write.
1545: * Note that we must not call 'chan_read_failed', since there could
1546: * be some more data waiting in the pipe.
1547: */
1.8 markus 1548: if (c->ostate != CHAN_OUTPUT_CLOSED)
1549: chan_write_failed(c);
1.2 markus 1550: s->chanid = -1;
1551: }
1552:
1553: void
1554: session_free(Session *s)
1555: {
1556: debug("session_free: session %d pid %d", s->self, s->pid);
1557: if (s->term)
1558: xfree(s->term);
1559: if (s->display)
1560: xfree(s->display);
1561: if (s->auth_data)
1562: xfree(s->auth_data);
1563: if (s->auth_proto)
1564: xfree(s->auth_proto);
1565: s->used = 0;
1566: }
1567:
1568: void
1569: session_close(Session *s)
1570: {
1571: session_pty_cleanup(s);
1572: session_free(s);
1.9 markus 1573: session_proctitle(s);
1.2 markus 1574: }
1575:
1576: void
1577: session_close_by_pid(pid_t pid, int status)
1578: {
1579: Session *s = session_by_pid(pid);
1580: if (s == NULL) {
1581: debug("session_close_by_pid: no session for pid %d", s->pid);
1582: return;
1583: }
1584: if (s->chanid != -1)
1585: session_exit_message(s, status);
1586: session_close(s);
1587: }
1588:
1589: /*
1590: * this is called when a channel dies before
1591: * the session 'child' itself dies
1592: */
1593: void
1594: session_close_by_channel(int id, void *arg)
1595: {
1596: Session *s = session_by_channel(id);
1597: if (s == NULL) {
1598: debug("session_close_by_channel: no session for channel %d", id);
1599: return;
1600: }
1601: /* disconnect channel */
1602: channel_cancel_cleanup(s->chanid);
1603: s->chanid = -1;
1604:
1605: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1606: if (s->pid == 0) {
1607: /* close session immediately */
1608: session_close(s);
1609: } else {
1610: /* notify child, delay session cleanup */
1611: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1612: error("session_close_by_channel: kill %d: %s",
1613: s->pid, strerror(errno));
1614: }
1.9 markus 1615: }
1616:
1617: char *
1618: session_tty_list(void)
1619: {
1620: static char buf[1024];
1621: int i;
1622: buf[0] = '\0';
1623: for(i = 0; i < MAX_SESSIONS; i++) {
1624: Session *s = &sessions[i];
1625: if (s->used && s->ttyfd != -1) {
1626: if (buf[0] != '\0')
1627: strlcat(buf, ",", sizeof buf);
1628: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1629: }
1630: }
1631: if (buf[0] == '\0')
1632: strlcpy(buf, "notty", sizeof buf);
1633: return buf;
1634: }
1635:
1636: void
1637: session_proctitle(Session *s)
1638: {
1639: if (s->pw == NULL)
1640: error("no user for session %d", s->self);
1641: else
1642: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1643: }
1644:
1645: void
1646: do_authenticated2(void)
1647: {
1.28 millert 1648: struct passwd *pw;
1649:
1.2 markus 1650: /*
1651: * Cancel the alarm we set to limit the time taken for
1652: * authentication.
1653: */
1654: alarm(0);
1.23 deraadt 1655: if (startup_pipe != -1) {
1656: close(startup_pipe);
1657: startup_pipe = -1;
1658: }
1.28 millert 1659: #ifdef HAVE_LOGIN_CAP
1660: pw = auth_get_user();
1661: if ((lc = login_getclass(pw->pw_class)) == NULL) {
1662: error("unable to get login class");
1663: return;
1664: }
1665: #endif
1.2 markus 1666: server_loop2();
1.7 markus 1667: if (xauthfile)
1668: xauthfile_cleanup_proc(NULL);
1.1 markus 1669: }
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