Annotation of src/usr.bin/ssh/session.c, Revision 1.45
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"
1.45 ! markus 36: RCSID("$OpenBSD: session.c,v 1.44 2000/11/14 23:44:19 markus 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);
1.41 markus 92: void do_login(Session *s, const char *command);
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;
1.45 ! markus 104: extern u_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;
1.45 ! markus 180: u_int proto_len, data_len, dlen;
1.1 markus 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: */
1.39 markus 199: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
1.1 markus 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.");
1.39 markus 349: break;
350: }
351: if (!options.allow_tcp_forwarding) {
352: debug("Port forwarding not permitted.");
1.1 markus 353: break;
354: }
355: debug("Received TCP/IP port forwarding request.");
1.12 markus 356: channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
1.1 markus 357: success = 1;
358: break;
359:
360: case SSH_CMSG_MAX_PACKET_SIZE:
361: if (packet_set_maxsize(packet_get_int()) > 0)
362: success = 1;
363: break;
364:
365: case SSH_CMSG_EXEC_SHELL:
366: case SSH_CMSG_EXEC_CMD:
367: /* Set interactive/non-interactive mode. */
368: packet_set_interactive(have_pty || s->display != NULL,
369: options.keepalives);
370:
371: if (type == SSH_CMSG_EXEC_CMD) {
372: command = packet_get_string(&dlen);
373: debug("Exec command '%.500s'", command);
374: packet_integrity_check(plen, 4 + dlen, type);
375: } else {
376: command = NULL;
377: packet_integrity_check(plen, 0, type);
378: }
379: if (forced_command != NULL) {
1.34 markus 380: original_command = command;
1.1 markus 381: command = forced_command;
382: debug("Forced command '%.500s'", forced_command);
383: }
384: if (have_pty)
385: do_exec_pty(s, command, pw);
386: else
387: do_exec_no_pty(s, command, pw);
388:
389: if (command != NULL)
390: xfree(command);
391: /* Cleanup user's local Xauthority file. */
392: if (xauthfile)
393: xauthfile_cleanup_proc(NULL);
394: return;
395:
396: default:
397: /*
398: * Any unknown messages in this phase are ignored,
399: * and a failure message is returned.
400: */
401: log("Unknown packet type received after authentication: %d", type);
402: }
403: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
404: packet_send();
405: packet_write_wait();
406:
407: /* Enable compression now that we have replied if appropriate. */
408: if (enable_compression_after_reply) {
409: enable_compression_after_reply = 0;
410: packet_start_compression(compression_level);
411: }
412: }
413: }
414:
415: /*
416: * This is called to fork and execute a command when we have no tty. This
417: * will call do_child from the child, and server_loop from the parent after
418: * setting up file descriptors and such.
419: */
1.4 markus 420: void
1.1 markus 421: do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
422: {
423: int pid;
424:
425: #ifdef USE_PIPES
426: int pin[2], pout[2], perr[2];
427: /* Allocate pipes for communicating with the program. */
428: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
429: packet_disconnect("Could not create pipes: %.100s",
430: strerror(errno));
431: #else /* USE_PIPES */
432: int inout[2], err[2];
433: /* Uses socket pairs to communicate with the program. */
434: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
435: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
436: packet_disconnect("Could not create socket pairs: %.100s",
437: strerror(errno));
438: #endif /* USE_PIPES */
439: if (s == NULL)
440: fatal("do_exec_no_pty: no session");
441:
1.9 markus 442: session_proctitle(s);
1.1 markus 443:
444: /* Fork the child. */
445: if ((pid = fork()) == 0) {
446: /* Child. Reinitialize the log since the pid has changed. */
447: log_init(__progname, options.log_level, options.log_facility, log_stderr);
448:
449: /*
450: * Create a new session and process group since the 4.4BSD
451: * setlogin() affects the entire process group.
452: */
453: if (setsid() < 0)
454: error("setsid failed: %.100s", strerror(errno));
455:
456: #ifdef USE_PIPES
457: /*
458: * Redirect stdin. We close the parent side of the socket
459: * pair, and make the child side the standard input.
460: */
461: close(pin[1]);
462: if (dup2(pin[0], 0) < 0)
463: perror("dup2 stdin");
464: close(pin[0]);
465:
466: /* Redirect stdout. */
467: close(pout[0]);
468: if (dup2(pout[1], 1) < 0)
469: perror("dup2 stdout");
470: close(pout[1]);
471:
472: /* Redirect stderr. */
473: close(perr[0]);
474: if (dup2(perr[1], 2) < 0)
475: perror("dup2 stderr");
476: close(perr[1]);
477: #else /* USE_PIPES */
478: /*
479: * Redirect stdin, stdout, and stderr. Stdin and stdout will
480: * use the same socket, as some programs (particularly rdist)
481: * seem to depend on it.
482: */
483: close(inout[1]);
484: close(err[1]);
485: if (dup2(inout[0], 0) < 0) /* stdin */
486: perror("dup2 stdin");
487: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
488: perror("dup2 stdout");
489: if (dup2(err[0], 2) < 0) /* stderr */
490: perror("dup2 stderr");
491: #endif /* USE_PIPES */
492:
493: /* Do processing for the child (exec command etc). */
494: do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL);
495: /* NOTREACHED */
496: }
497: if (pid < 0)
498: packet_disconnect("fork failed: %.100s", strerror(errno));
499: s->pid = pid;
500: #ifdef USE_PIPES
501: /* We are the parent. Close the child sides of the pipes. */
502: close(pin[0]);
503: close(pout[1]);
504: close(perr[1]);
505:
1.2 markus 506: if (compat20) {
1.7 markus 507: session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
1.2 markus 508: } else {
509: /* Enter the interactive session. */
510: server_loop(pid, pin[1], pout[0], perr[0]);
511: /* server_loop has closed pin[1], pout[1], and perr[1]. */
512: }
1.1 markus 513: #else /* USE_PIPES */
514: /* We are the parent. Close the child sides of the socket pairs. */
515: close(inout[0]);
516: close(err[0]);
517:
518: /*
519: * Enter the interactive session. Note: server_loop must be able to
520: * handle the case that fdin and fdout are the same.
521: */
1.2 markus 522: if (compat20) {
1.7 markus 523: session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
1.2 markus 524: } else {
525: server_loop(pid, inout[1], inout[1], err[1]);
526: /* server_loop has closed inout[1] and err[1]. */
527: }
1.1 markus 528: #endif /* USE_PIPES */
529: }
530:
531: /*
532: * This is called to fork and execute a command when we have a tty. This
533: * will call do_child from the child, and server_loop from the parent after
534: * setting up file descriptors, controlling tty, updating wtmp, utmp,
535: * lastlog, and other such operations.
536: */
1.4 markus 537: void
1.1 markus 538: do_exec_pty(Session *s, const char *command, struct passwd * pw)
539: {
540: int fdout, ptyfd, ttyfd, ptymaster;
541: pid_t pid;
542:
543: if (s == NULL)
544: fatal("do_exec_pty: no session");
545: ptyfd = s->ptyfd;
546: ttyfd = s->ttyfd;
547:
548: /* Fork the child. */
549: if ((pid = fork()) == 0) {
1.24 markus 550: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 551: log_init(__progname, options.log_level, options.log_facility, log_stderr);
552:
553: /* Close the master side of the pseudo tty. */
554: close(ptyfd);
555:
556: /* Make the pseudo tty our controlling tty. */
557: pty_make_controlling_tty(&ttyfd, s->tty);
558:
559: /* Redirect stdin from the pseudo tty. */
560: if (dup2(ttyfd, fileno(stdin)) < 0)
561: error("dup2 stdin failed: %.100s", strerror(errno));
562:
563: /* Redirect stdout to the pseudo tty. */
564: if (dup2(ttyfd, fileno(stdout)) < 0)
565: error("dup2 stdin failed: %.100s", strerror(errno));
566:
567: /* Redirect stderr to the pseudo tty. */
568: if (dup2(ttyfd, fileno(stderr)) < 0)
569: error("dup2 stdin failed: %.100s", strerror(errno));
570:
571: /* Close the extra descriptor for the pseudo tty. */
572: close(ttyfd);
573:
1.24 markus 574: /* record login, etc. similar to login(1) */
1.41 markus 575: if (!(options.use_login && command == NULL))
576: do_login(s, command);
1.1 markus 577:
578: /* Do common processing for the child, such as execing the command. */
1.14 deraadt 579: do_child(command, pw, s->term, s->display, s->auth_proto,
580: s->auth_data, s->tty);
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. */
1.2 markus 606: if (compat20) {
607: session_set_fds(s, ptyfd, fdout, -1);
608: } else {
609: server_loop(pid, ptyfd, fdout, -1);
610: /* server_loop _has_ closed ptyfd and fdout. */
611: session_pty_cleanup(s);
1.24 markus 612: }
613: }
614:
1.25 markus 615: const char *
616: get_remote_name_or_ip(void)
617: {
618: static const char *remote = "";
619: if (utmp_len > 0)
620: remote = get_canonical_hostname();
621: if (utmp_len == 0 || strlen(remote) > utmp_len)
622: remote = get_remote_ipaddr();
623: return remote;
624: }
625:
1.24 markus 626: /* administrative, login(1)-like work */
627: void
1.41 markus 628: do_login(Session *s, const char *command)
1.24 markus 629: {
630: FILE *f;
631: char *time_string;
632: char buf[256];
1.35 markus 633: char hostname[MAXHOSTNAMELEN];
1.24 markus 634: socklen_t fromlen;
635: struct sockaddr_storage from;
636: struct stat st;
637: time_t last_login_time;
638: struct passwd * pw = s->pw;
639: pid_t pid = getpid();
640:
641: /*
642: * Get IP address of client. If the connection is not a socket, let
643: * the address be 0.0.0.0.
644: */
645: memset(&from, 0, sizeof(from));
646: if (packet_connection_is_on_socket()) {
647: fromlen = sizeof(from);
648: if (getpeername(packet_get_connection_in(),
649: (struct sockaddr *) & from, &fromlen) < 0) {
650: debug("getpeername: %.100s", strerror(errno));
651: fatal_cleanup();
652: }
653: }
1.25 markus 654:
1.35 markus 655: /* Get the time and hostname when the user last logged in. */
1.36 markus 656: hostname[0] = '\0';
1.35 markus 657: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
658: hostname, sizeof(hostname));
659:
1.24 markus 660: /* Record that there was a login on that tty from the remote host. */
661: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.25 markus 662: get_remote_name_or_ip(), (struct sockaddr *)&from);
1.24 markus 663:
1.41 markus 664: /* Done if .hushlogin exists or a command given. */
665: if (command != NULL)
666: return;
1.24 markus 667: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
1.28 millert 668: #ifdef HAVE_LOGIN_CAP
669: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
670: #else
1.24 markus 671: if (stat(buf, &st) >= 0)
1.28 millert 672: #endif
1.24 markus 673: return;
674: if (last_login_time != 0) {
675: time_string = ctime(&last_login_time);
676: if (strchr(time_string, '\n'))
677: *strchr(time_string, '\n') = 0;
1.40 markus 678: if (strcmp(hostname, "") == 0)
1.24 markus 679: printf("Last login: %s\r\n", time_string);
680: else
1.36 markus 681: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 682: }
683: if (options.print_motd) {
1.28 millert 684: #ifdef HAVE_LOGIN_CAP
685: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
686: "/etc/motd"), "r");
687: #else
1.24 markus 688: f = fopen("/etc/motd", "r");
1.28 millert 689: #endif
1.24 markus 690: if (f) {
691: while (fgets(buf, sizeof(buf), f))
692: fputs(buf, stdout);
693: fclose(f);
694: }
1.2 markus 695: }
1.1 markus 696: }
697:
698: /*
699: * Sets the value of the given variable in the environment. If the variable
700: * already exists, its value is overriden.
701: */
1.4 markus 702: void
1.45 ! markus 703: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 704: const char *value)
705: {
1.45 ! markus 706: u_int i, namelen;
1.1 markus 707: char **env;
708:
709: /*
710: * Find the slot where the value should be stored. If the variable
711: * already exists, we reuse the slot; otherwise we append a new slot
712: * at the end of the array, expanding if necessary.
713: */
714: env = *envp;
715: namelen = strlen(name);
716: for (i = 0; env[i]; i++)
717: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
718: break;
719: if (env[i]) {
720: /* Reuse the slot. */
721: xfree(env[i]);
722: } else {
723: /* New variable. Expand if necessary. */
724: if (i >= (*envsizep) - 1) {
725: (*envsizep) += 50;
726: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
727: }
728: /* Need to set the NULL pointer at end of array beyond the new slot. */
729: env[i + 1] = NULL;
730: }
731:
732: /* Allocate space and format the variable in the appropriate slot. */
733: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
734: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
735: }
736:
737: /*
738: * Reads environment variables from the given file and adds/overrides them
739: * into the environment. If the file does not exist, this does nothing.
740: * Otherwise, it must consist of empty lines, comments (line starts with '#')
741: * and assignments of the form name=value. No other forms are allowed.
742: */
1.4 markus 743: void
1.45 ! markus 744: read_environment_file(char ***env, u_int *envsize,
1.1 markus 745: const char *filename)
746: {
747: FILE *f;
748: char buf[4096];
749: char *cp, *value;
750:
751: f = fopen(filename, "r");
752: if (!f)
753: return;
754:
755: while (fgets(buf, sizeof(buf), f)) {
756: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
757: ;
758: if (!*cp || *cp == '#' || *cp == '\n')
759: continue;
760: if (strchr(cp, '\n'))
761: *strchr(cp, '\n') = '\0';
762: value = strchr(cp, '=');
763: if (value == NULL) {
764: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
765: continue;
766: }
1.14 deraadt 767: /*
768: * Replace the equals sign by nul, and advance value to
769: * the value string.
770: */
1.1 markus 771: *value = '\0';
772: value++;
773: child_set_env(env, envsize, cp, value);
774: }
775: fclose(f);
776: }
777:
778: /*
779: * Performs common processing for the child, such as setting up the
780: * environment, closing extra file descriptors, setting the user and group
781: * ids, and executing the command or shell.
782: */
1.4 markus 783: void
1.1 markus 784: do_child(const char *command, struct passwd * pw, const char *term,
785: const char *display, const char *auth_proto,
786: const char *auth_data, const char *ttyname)
787: {
1.32 markus 788: const char *shell, *hostname = NULL, *cp = NULL;
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];
1.17 markus 797:
798: /* login(1) is only called if we execute the login shell */
799: if (options.use_login && command != NULL)
800: options.use_login = 0;
1.1 markus 801:
1.27 millert 802: if (!options.use_login) {
1.28 millert 803: #ifdef HAVE_LOGIN_CAP
804: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
805: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
806: _PATH_NOLOGIN), "r");
807: #else
1.27 millert 808: if (pw->pw_uid)
809: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 810: #endif
1.27 millert 811: if (f) {
812: /* /etc/nologin exists. Print its contents and exit. */
813: while (fgets(buf, sizeof(buf), f))
814: fputs(buf, stderr);
815: fclose(f);
1.1 markus 816: exit(254);
1.27 millert 817: }
1.1 markus 818: }
1.28 millert 819: /* Set login name, uid, gid, and groups. */
1.1 markus 820: /* Login(1) does this as well, and it needs uid 0 for the "-h"
821: switch, so we let login(1) to this for us. */
822: if (!options.use_login) {
823: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 824: #ifdef HAVE_LOGIN_CAP
825: if (setusercontext(lc, pw, pw->pw_uid,
826: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
827: perror("unable to set user context");
828: exit(1);
829:
830: }
831: #else
832: if (setlogin(pw->pw_name) < 0)
833: error("setlogin failed: %s", strerror(errno));
1.1 markus 834: if (setgid(pw->pw_gid) < 0) {
835: perror("setgid");
836: exit(1);
837: }
838: /* Initialize the group list. */
839: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
840: perror("initgroups");
841: exit(1);
842: }
843: endgrent();
844:
845: /* Permanently switch to the desired uid. */
846: permanently_set_uid(pw->pw_uid);
1.28 millert 847: #endif
1.1 markus 848: }
849: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 850: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 851: }
852: /*
853: * Get the shell from the password data. An empty shell field is
854: * legal, and means /bin/sh.
855: */
856: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 857: #ifdef HAVE_LOGIN_CAP
858: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
859: #endif
1.1 markus 860:
861: #ifdef AFS
862: /* Try to get AFS tokens for the local cell. */
863: if (k_hasafs()) {
864: char cell[64];
865:
866: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
867: krb_afslog(cell, 0);
868:
869: krb_afslog(0, 0);
870: }
871: #endif /* AFS */
872:
873: /* Initialize the environment. */
874: envsize = 100;
875: env = xmalloc(envsize * sizeof(char *));
876: env[0] = NULL;
877:
878: if (!options.use_login) {
879: /* Set basic environment. */
880: child_set_env(&env, &envsize, "USER", pw->pw_name);
881: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
882: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 883: #ifdef HAVE_LOGIN_CAP
1.29 millert 884: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
885: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 886: #else
1.29 millert 887: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 888: #endif
1.1 markus 889:
890: snprintf(buf, sizeof buf, "%.200s/%.50s",
891: _PATH_MAILDIR, pw->pw_name);
892: child_set_env(&env, &envsize, "MAIL", buf);
893:
894: /* Normal systems set SHELL by default. */
895: child_set_env(&env, &envsize, "SHELL", shell);
896: }
897: if (getenv("TZ"))
898: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
899:
900: /* Set custom environment options from RSA authentication. */
901: while (custom_environment) {
902: struct envstring *ce = custom_environment;
903: char *s = ce->s;
904: int i;
905: for (i = 0; s[i] != '=' && s[i]; i++);
906: if (s[i] == '=') {
907: s[i] = 0;
908: child_set_env(&env, &envsize, s, s + i + 1);
909: }
910: custom_environment = ce->next;
911: xfree(ce->s);
912: xfree(ce);
913: }
914:
915: snprintf(buf, sizeof buf, "%.50s %d %d",
916: get_remote_ipaddr(), get_remote_port(), get_local_port());
917: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
918:
919: if (ttyname)
920: child_set_env(&env, &envsize, "SSH_TTY", ttyname);
921: if (term)
922: child_set_env(&env, &envsize, "TERM", term);
923: if (display)
924: child_set_env(&env, &envsize, "DISPLAY", display);
1.34 markus 925: if (original_command)
926: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
927: original_command);
1.1 markus 928:
929: #ifdef KRB4
930: {
931: extern char *ticket;
932:
933: if (ticket)
934: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
935: }
936: #endif /* KRB4 */
937:
938: if (xauthfile)
939: child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
940: if (auth_get_socket_name() != NULL)
941: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
942: auth_get_socket_name());
943:
944: /* read $HOME/.ssh/environment. */
945: if (!options.use_login) {
1.14 deraadt 946: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
947: pw->pw_dir);
1.1 markus 948: read_environment_file(&env, &envsize, buf);
949: }
950: if (debug_flag) {
951: /* dump the environment */
952: fprintf(stderr, "Environment:\n");
953: for (i = 0; env[i]; i++)
954: fprintf(stderr, " %.200s\n", env[i]);
955: }
1.26 millert 956: /* we have to stash the hostname before we close our socket. */
957: if (options.use_login)
958: hostname = get_remote_name_or_ip();
1.1 markus 959: /*
960: * Close the connection descriptors; note that this is the child, and
961: * the server will still have the socket open, and it is important
962: * that we do not shutdown it. Note that the descriptors cannot be
963: * closed before building the environment, as we call
964: * get_remote_ipaddr there.
965: */
966: if (packet_get_connection_in() == packet_get_connection_out())
967: close(packet_get_connection_in());
968: else {
969: close(packet_get_connection_in());
970: close(packet_get_connection_out());
971: }
972: /*
973: * Close all descriptors related to channels. They will still remain
974: * open in the parent.
975: */
976: /* XXX better use close-on-exec? -markus */
977: channel_close_all();
978:
979: /*
980: * Close any extra file descriptors. Note that there may still be
981: * descriptors left by system functions. They will be closed later.
982: */
983: endpwent();
984:
985: /*
986: * Close any extra open file descriptors so that we don\'t have them
987: * hanging around in clients. Note that we want to do this after
988: * initgroups, because at least on Solaris 2.3 it leaves file
989: * descriptors open.
990: */
991: for (i = 3; i < 64; i++)
992: close(i);
993:
994: /* Change current directory to the user\'s home directory. */
1.28 millert 995: if (chdir(pw->pw_dir) < 0) {
1.1 markus 996: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
997: pw->pw_dir, strerror(errno));
1.28 millert 998: #ifdef HAVE_LOGIN_CAP
999: if (login_getcapbool(lc, "requirehome", 0))
1000: exit(1);
1001: #endif
1002: }
1.1 markus 1003:
1004: /*
1005: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1006: * xauth are run in the proper environment.
1007: */
1008: environ = env;
1009:
1010: /*
1011: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1012: * in this order).
1013: */
1014: if (!options.use_login) {
1015: if (stat(SSH_USER_RC, &st) >= 0) {
1016: if (debug_flag)
1017: fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC);
1018:
1019: f = popen("/bin/sh " SSH_USER_RC, "w");
1020: if (f) {
1021: if (auth_proto != NULL && auth_data != NULL)
1022: fprintf(f, "%s %s\n", auth_proto, auth_data);
1023: pclose(f);
1024: } else
1025: fprintf(stderr, "Could not run %s\n", SSH_USER_RC);
1026: } else if (stat(SSH_SYSTEM_RC, &st) >= 0) {
1027: if (debug_flag)
1028: fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC);
1029:
1030: f = popen("/bin/sh " SSH_SYSTEM_RC, "w");
1031: if (f) {
1032: if (auth_proto != NULL && auth_data != NULL)
1033: fprintf(f, "%s %s\n", auth_proto, auth_data);
1034: pclose(f);
1035: } else
1036: fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC);
1.16 markus 1037: } else if (options.xauth_location != NULL) {
1.1 markus 1038: /* Add authority data to .Xauthority if appropriate. */
1039: if (auth_proto != NULL && auth_data != NULL) {
1.13 markus 1040: char *screen = strchr(display, ':');
1041: if (debug_flag) {
1.14 deraadt 1042: fprintf(stderr,
1043: "Running %.100s add %.100s %.100s %.100s\n",
1.16 markus 1044: options.xauth_location, display,
1045: auth_proto, auth_data);
1.13 markus 1046: if (screen != NULL)
1.14 deraadt 1047: fprintf(stderr,
1048: "Adding %.*s/unix%s %s %s\n",
1.30 deraadt 1049: (int)(screen-display), display,
1.14 deraadt 1050: screen, auth_proto, auth_data);
1.13 markus 1051: }
1.16 markus 1052: snprintf(cmd, sizeof cmd, "%s -q -",
1053: options.xauth_location);
1054: f = popen(cmd, "w");
1.1 markus 1055: if (f) {
1.14 deraadt 1056: fprintf(f, "add %s %s %s\n", display,
1057: auth_proto, auth_data);
1.13 markus 1058: if (screen != NULL)
1059: fprintf(f, "add %.*s/unix%s %s %s\n",
1.30 deraadt 1060: (int)(screen-display), display,
1.14 deraadt 1061: screen, auth_proto, auth_data);
1.1 markus 1062: pclose(f);
1.16 markus 1063: } else {
1064: fprintf(stderr, "Could not run %s\n",
1065: cmd);
1066: }
1.1 markus 1067: }
1068: }
1069: /* Get the last component of the shell name. */
1070: cp = strrchr(shell, '/');
1071: if (cp)
1072: cp++;
1073: else
1074: cp = shell;
1075: }
1076: /*
1077: * If we have no command, execute the shell. In this case, the shell
1078: * name to be passed in argv[0] is preceded by '-' to indicate that
1079: * this is a login shell.
1080: */
1081: if (!command) {
1082: if (!options.use_login) {
1083: char buf[256];
1084:
1085: /*
1086: * Check for mail if we have a tty and it was enabled
1087: * in server options.
1088: */
1089: if (ttyname && options.check_mail) {
1090: char *mailbox;
1091: struct stat mailstat;
1092: mailbox = getenv("MAIL");
1093: if (mailbox != NULL) {
1.14 deraadt 1094: if (stat(mailbox, &mailstat) != 0 ||
1095: mailstat.st_size == 0)
1.1 markus 1096: printf("No mail.\n");
1097: else if (mailstat.st_mtime < mailstat.st_atime)
1098: printf("You have mail.\n");
1099: else
1100: printf("You have new mail.\n");
1101: }
1102: }
1103: /* Start the shell. Set initial character to '-'. */
1104: buf[0] = '-';
1105: strncpy(buf + 1, cp, sizeof(buf) - 1);
1106: buf[sizeof(buf) - 1] = 0;
1107:
1108: /* Execute the shell. */
1109: argv[0] = buf;
1110: argv[1] = NULL;
1111: execve(shell, argv, env);
1112:
1113: /* Executing the shell failed. */
1114: perror(shell);
1115: exit(1);
1116:
1117: } else {
1118: /* Launch login(1). */
1119:
1.26 millert 1120: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1121: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1122:
1123: /* Login couldn't be executed, die. */
1124:
1125: perror("login");
1126: exit(1);
1127: }
1128: }
1129: /*
1130: * Execute the command using the user's shell. This uses the -c
1131: * option to execute the command.
1132: */
1133: argv[0] = (char *) cp;
1134: argv[1] = "-c";
1135: argv[2] = (char *) command;
1136: argv[3] = NULL;
1137: execve(shell, argv, env);
1138: perror(shell);
1139: exit(1);
1140: }
1141:
1142: Session *
1143: session_new(void)
1144: {
1145: int i;
1146: static int did_init = 0;
1147: if (!did_init) {
1148: debug("session_new: init");
1149: for(i = 0; i < MAX_SESSIONS; i++) {
1150: sessions[i].used = 0;
1151: sessions[i].self = i;
1152: }
1153: did_init = 1;
1154: }
1155: for(i = 0; i < MAX_SESSIONS; i++) {
1156: Session *s = &sessions[i];
1157: if (! s->used) {
1158: s->pid = 0;
1.7 markus 1159: s->extended = 0;
1.1 markus 1160: s->chanid = -1;
1161: s->ptyfd = -1;
1162: s->ttyfd = -1;
1163: s->term = NULL;
1164: s->pw = NULL;
1165: s->display = NULL;
1166: s->screen = 0;
1167: s->auth_data = NULL;
1168: s->auth_proto = NULL;
1169: s->used = 1;
1.7 markus 1170: s->pw = NULL;
1.1 markus 1171: debug("session_new: session %d", i);
1172: return s;
1173: }
1174: }
1175: return NULL;
1176: }
1177:
1178: void
1179: session_dump(void)
1180: {
1181: int i;
1182: for(i = 0; i < MAX_SESSIONS; i++) {
1183: Session *s = &sessions[i];
1184: debug("dump: used %d session %d %p channel %d pid %d",
1185: s->used,
1186: s->self,
1187: s,
1188: s->chanid,
1189: s->pid);
1190: }
1191: }
1192:
1.2 markus 1193: int
1194: session_open(int chanid)
1195: {
1196: Session *s = session_new();
1197: debug("session_open: channel %d", chanid);
1198: if (s == NULL) {
1199: error("no more sessions");
1200: return 0;
1201: }
1.7 markus 1202: s->pw = auth_get_user();
1203: if (s->pw == NULL)
1204: fatal("no user for session %i", s->self);
1.2 markus 1205: debug("session_open: session %d: link with channel %d", s->self, chanid);
1206: s->chanid = chanid;
1207: return 1;
1208: }
1209:
1210: Session *
1211: session_by_channel(int id)
1212: {
1213: int i;
1214: for(i = 0; i < MAX_SESSIONS; i++) {
1215: Session *s = &sessions[i];
1216: if (s->used && s->chanid == id) {
1217: debug("session_by_channel: session %d channel %d", i, id);
1218: return s;
1219: }
1220: }
1221: debug("session_by_channel: unknown channel %d", id);
1222: session_dump();
1223: return NULL;
1224: }
1225:
1226: Session *
1227: session_by_pid(pid_t pid)
1228: {
1229: int i;
1230: debug("session_by_pid: pid %d", pid);
1231: for(i = 0; i < MAX_SESSIONS; i++) {
1232: Session *s = &sessions[i];
1233: if (s->used && s->pid == pid)
1234: return s;
1235: }
1236: error("session_by_pid: unknown pid %d", pid);
1237: session_dump();
1238: return NULL;
1239: }
1240:
1241: int
1242: session_window_change_req(Session *s)
1243: {
1244: s->col = packet_get_int();
1245: s->row = packet_get_int();
1246: s->xpixel = packet_get_int();
1247: s->ypixel = packet_get_int();
1.3 markus 1248: packet_done();
1.2 markus 1249: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1250: return 1;
1251: }
1252:
1253: int
1254: session_pty_req(Session *s)
1255: {
1.45 ! markus 1256: u_int len;
1.3 markus 1257: char *term_modes; /* encoded terminal modes */
1.2 markus 1258:
1.19 markus 1259: if (no_pty_flag)
1260: return 0;
1.2 markus 1261: if (s->ttyfd != -1)
1.3 markus 1262: return 0;
1.2 markus 1263: s->term = packet_get_string(&len);
1264: s->col = packet_get_int();
1265: s->row = packet_get_int();
1266: s->xpixel = packet_get_int();
1267: s->ypixel = packet_get_int();
1.3 markus 1268: term_modes = packet_get_string(&len);
1269: packet_done();
1.2 markus 1270:
1271: if (strcmp(s->term, "") == 0) {
1272: xfree(s->term);
1273: s->term = NULL;
1274: }
1275: /* Allocate a pty and open it. */
1276: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1277: xfree(s->term);
1278: s->term = NULL;
1279: s->ptyfd = -1;
1280: s->ttyfd = -1;
1281: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1282: xfree(term_modes);
1283: return 0;
1.2 markus 1284: }
1285: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1286: /*
1287: * Add a cleanup function to clear the utmp entry and record logout
1288: * time in case we call fatal() (e.g., the connection gets closed).
1289: */
1290: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1291: pty_setowner(s->pw, s->tty);
1292: /* Get window size from the packet. */
1293: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1294:
1.9 markus 1295: session_proctitle(s);
1296:
1.3 markus 1297: /* XXX parse and set terminal modes */
1298: xfree(term_modes);
1.2 markus 1299: return 1;
1300: }
1301:
1.7 markus 1302: int
1303: session_subsystem_req(Session *s)
1304: {
1.45 ! markus 1305: u_int len;
1.7 markus 1306: int success = 0;
1307: char *subsys = packet_get_string(&len);
1.18 jakob 1308: int i;
1.7 markus 1309:
1310: packet_done();
1311: log("subsystem request for %s", subsys);
1.18 jakob 1312:
1313: for (i = 0; i < options.num_subsystems; i++) {
1314: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1315: debug("subsystem: exec() %s", options.subsystem_command[i]);
1316: do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1317: success = 1;
1318: }
1319: }
1320:
1321: if (!success)
1322: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1323:
1324: xfree(subsys);
1325: return success;
1326: }
1327:
1328: int
1329: session_x11_req(Session *s)
1330: {
1.33 markus 1331: int fd;
1.22 deraadt 1332: if (no_x11_forwarding_flag) {
1.19 markus 1333: debug("X11 forwarding disabled in user configuration file.");
1334: return 0;
1335: }
1.7 markus 1336: if (!options.x11_forwarding) {
1337: debug("X11 forwarding disabled in server configuration file.");
1338: return 0;
1339: }
1340: if (xauthfile != NULL) {
1341: debug("X11 fwd already started.");
1342: return 0;
1343: }
1344:
1345: debug("Received request for X11 forwarding with auth spoofing.");
1346: if (s->display != NULL)
1347: packet_disconnect("Protocol error: X11 display already set.");
1348:
1349: s->single_connection = packet_get_char();
1350: s->auth_proto = packet_get_string(NULL);
1351: s->auth_data = packet_get_string(NULL);
1352: s->screen = packet_get_int();
1353: packet_done();
1354:
1355: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1356: if (s->display == NULL) {
1357: xfree(s->auth_proto);
1358: xfree(s->auth_data);
1359: return 0;
1360: }
1361: xauthfile = xmalloc(MAXPATHLEN);
1362: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1363: temporarily_use_uid(s->pw->pw_uid);
1364: if (mkdtemp(xauthfile) == NULL) {
1365: restore_uid();
1366: error("private X11 dir: mkdtemp %s failed: %s",
1367: xauthfile, strerror(errno));
1368: xfree(xauthfile);
1369: xauthfile = NULL;
1370: xfree(s->auth_proto);
1371: xfree(s->auth_data);
1372: /* XXXX remove listening channels */
1373: return 0;
1374: }
1375: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 1376: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1377: if (fd >= 0)
1378: close(fd);
1.7 markus 1379: restore_uid();
1380: fatal_add_cleanup(xauthfile_cleanup_proc, s);
1381: return 1;
1382: }
1383:
1.19 markus 1384: int
1385: session_shell_req(Session *s)
1386: {
1387: /* if forced_command == NULL, the shell is execed */
1388: char *shell = forced_command;
1389: packet_done();
1390: s->extended = 1;
1391: if (s->ttyfd == -1)
1392: do_exec_no_pty(s, shell, s->pw);
1393: else
1394: do_exec_pty(s, shell, s->pw);
1395: return 1;
1396: }
1397:
1398: int
1399: session_exec_req(Session *s)
1400: {
1.45 ! markus 1401: u_int len;
1.19 markus 1402: char *command = packet_get_string(&len);
1403: packet_done();
1404: if (forced_command) {
1.34 markus 1405: original_command = command;
1.19 markus 1406: command = forced_command;
1407: debug("Forced command '%.500s'", forced_command);
1408: }
1409: s->extended = 1;
1410: if (s->ttyfd == -1)
1411: do_exec_no_pty(s, command, s->pw);
1412: else
1413: do_exec_pty(s, command, s->pw);
1414: if (forced_command == NULL)
1415: xfree(command);
1416: return 1;
1417: }
1418:
1.43 markus 1419: int
1420: session_auth_agent_req(Session *s)
1421: {
1422: static int called = 0;
1423: packet_done();
1.44 markus 1424: if (no_agent_forwarding_flag) {
1425: debug("session_auth_agent_req: no_agent_forwarding_flag");
1426: return 0;
1427: }
1.43 markus 1428: if (called) {
1429: return 0;
1430: } else {
1431: called = 1;
1432: return auth_input_request_forwarding(s->pw);
1433: }
1434: }
1435:
1.2 markus 1436: void
1437: session_input_channel_req(int id, void *arg)
1438: {
1.45 ! markus 1439: u_int len;
1.2 markus 1440: int reply;
1441: int success = 0;
1442: char *rtype;
1443: Session *s;
1444: Channel *c;
1445:
1446: rtype = packet_get_string(&len);
1447: reply = packet_get_char();
1448:
1449: s = session_by_channel(id);
1450: if (s == NULL)
1451: fatal("session_input_channel_req: channel %d: no session", id);
1452: c = channel_lookup(id);
1453: if (c == NULL)
1454: fatal("session_input_channel_req: channel %d: bad channel", id);
1455:
1456: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1457: s->self, id, rtype, reply);
1458:
1459: /*
1460: * a session is in LARVAL state until a shell
1461: * or programm is executed
1462: */
1463: if (c->type == SSH_CHANNEL_LARVAL) {
1464: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1465: success = session_shell_req(s);
1.2 markus 1466: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1467: success = session_exec_req(s);
1.2 markus 1468: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1469: success = session_pty_req(s);
1.7 markus 1470: } else if (strcmp(rtype, "x11-req") == 0) {
1471: success = session_x11_req(s);
1.43 markus 1472: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1473: success = session_auth_agent_req(s);
1.7 markus 1474: } else if (strcmp(rtype, "subsystem") == 0) {
1475: success = session_subsystem_req(s);
1.2 markus 1476: }
1477: }
1478: if (strcmp(rtype, "window-change") == 0) {
1479: success = session_window_change_req(s);
1480: }
1481:
1482: if (reply) {
1483: packet_start(success ?
1484: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1485: packet_put_int(c->remote_id);
1486: packet_send();
1487: }
1488: xfree(rtype);
1489: }
1490:
1491: void
1492: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1493: {
1494: if (!compat20)
1495: fatal("session_set_fds: called for proto != 2.0");
1496: /*
1497: * now that have a child and a pipe to the child,
1498: * we can activate our channel and register the fd's
1499: */
1500: if (s->chanid == -1)
1501: fatal("no channel for session %d", s->self);
1502: channel_set_fds(s->chanid,
1503: fdout, fdin, fderr,
1.42 markus 1504: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1505: 1);
1.2 markus 1506: }
1507:
1.1 markus 1508: void
1509: session_pty_cleanup(Session *s)
1510: {
1511: if (s == NULL || s->ttyfd == -1)
1512: return;
1513:
1514: debug("session_pty_cleanup: session %i release %s", s->self, s->tty);
1515:
1516: /* Cancel the cleanup function. */
1517: fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1518:
1519: /* Record that the user has logged out. */
1520: record_logout(s->pid, s->tty);
1521:
1522: /* Release the pseudo-tty. */
1523: pty_release(s->tty);
1524:
1525: /*
1526: * Close the server side of the socket pairs. We must do this after
1527: * the pty cleanup, so that another process doesn't get this pty
1528: * while we're still cleaning up.
1529: */
1530: if (close(s->ptymaster) < 0)
1531: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1532: }
1533:
1534: void
1535: session_exit_message(Session *s, int status)
1536: {
1537: Channel *c;
1538: if (s == NULL)
1539: fatal("session_close: no session");
1540: c = channel_lookup(s->chanid);
1541: if (c == NULL)
1542: fatal("session_close: session %d: no channel %d",
1543: s->self, s->chanid);
1544: debug("session_exit_message: session %d channel %d pid %d",
1545: s->self, s->chanid, s->pid);
1546:
1547: if (WIFEXITED(status)) {
1548: channel_request_start(s->chanid,
1549: "exit-status", 0);
1550: packet_put_int(WEXITSTATUS(status));
1551: packet_send();
1552: } else if (WIFSIGNALED(status)) {
1553: channel_request_start(s->chanid,
1554: "exit-signal", 0);
1555: packet_put_int(WTERMSIG(status));
1556: packet_put_char(WCOREDUMP(status));
1557: packet_put_cstring("");
1558: packet_put_cstring("");
1559: packet_send();
1560: } else {
1561: /* Some weird exit cause. Just exit. */
1562: packet_disconnect("wait returned status %04x.", status);
1563: }
1564:
1565: /* disconnect channel */
1566: debug("session_exit_message: release channel %d", s->chanid);
1567: channel_cancel_cleanup(s->chanid);
1.5 markus 1568: /*
1569: * emulate a write failure with 'chan_write_failed', nobody will be
1570: * interested in data we write.
1571: * Note that we must not call 'chan_read_failed', since there could
1572: * be some more data waiting in the pipe.
1573: */
1.8 markus 1574: if (c->ostate != CHAN_OUTPUT_CLOSED)
1575: chan_write_failed(c);
1.2 markus 1576: s->chanid = -1;
1577: }
1578:
1579: void
1580: session_free(Session *s)
1581: {
1582: debug("session_free: session %d pid %d", s->self, s->pid);
1583: if (s->term)
1584: xfree(s->term);
1585: if (s->display)
1586: xfree(s->display);
1587: if (s->auth_data)
1588: xfree(s->auth_data);
1589: if (s->auth_proto)
1590: xfree(s->auth_proto);
1591: s->used = 0;
1592: }
1593:
1594: void
1595: session_close(Session *s)
1596: {
1597: session_pty_cleanup(s);
1598: session_free(s);
1.9 markus 1599: session_proctitle(s);
1.2 markus 1600: }
1601:
1602: void
1603: session_close_by_pid(pid_t pid, int status)
1604: {
1605: Session *s = session_by_pid(pid);
1606: if (s == NULL) {
1607: debug("session_close_by_pid: no session for pid %d", s->pid);
1608: return;
1609: }
1610: if (s->chanid != -1)
1611: session_exit_message(s, status);
1612: session_close(s);
1613: }
1614:
1615: /*
1616: * this is called when a channel dies before
1617: * the session 'child' itself dies
1618: */
1619: void
1620: session_close_by_channel(int id, void *arg)
1621: {
1622: Session *s = session_by_channel(id);
1623: if (s == NULL) {
1624: debug("session_close_by_channel: no session for channel %d", id);
1625: return;
1626: }
1627: /* disconnect channel */
1628: channel_cancel_cleanup(s->chanid);
1629: s->chanid = -1;
1630:
1631: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1632: if (s->pid == 0) {
1633: /* close session immediately */
1634: session_close(s);
1635: } else {
1636: /* notify child, delay session cleanup */
1637: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1638: error("session_close_by_channel: kill %d: %s",
1639: s->pid, strerror(errno));
1640: }
1.9 markus 1641: }
1642:
1643: char *
1644: session_tty_list(void)
1645: {
1646: static char buf[1024];
1647: int i;
1648: buf[0] = '\0';
1649: for(i = 0; i < MAX_SESSIONS; i++) {
1650: Session *s = &sessions[i];
1651: if (s->used && s->ttyfd != -1) {
1652: if (buf[0] != '\0')
1653: strlcat(buf, ",", sizeof buf);
1654: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1655: }
1656: }
1657: if (buf[0] == '\0')
1658: strlcpy(buf, "notty", sizeof buf);
1659: return buf;
1660: }
1661:
1662: void
1663: session_proctitle(Session *s)
1664: {
1665: if (s->pw == NULL)
1666: error("no user for session %d", s->self);
1667: else
1668: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1669: }
1670:
1671: void
1672: do_authenticated2(void)
1673: {
1.28 millert 1674: struct passwd *pw;
1675:
1.2 markus 1676: /*
1677: * Cancel the alarm we set to limit the time taken for
1678: * authentication.
1679: */
1680: alarm(0);
1.23 deraadt 1681: if (startup_pipe != -1) {
1682: close(startup_pipe);
1683: startup_pipe = -1;
1684: }
1.28 millert 1685: #ifdef HAVE_LOGIN_CAP
1686: pw = auth_get_user();
1687: if ((lc = login_getclass(pw->pw_class)) == NULL) {
1688: error("unable to get login class");
1689: return;
1690: }
1691: #endif
1.2 markus 1692: server_loop2();
1.7 markus 1693: if (xauthfile)
1694: xauthfile_cleanup_proc(NULL);
1.1 markus 1695: }
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