Annotation of src/usr.bin/ssh/session.c, Revision 1.47
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"
1.47 ! markus 36: RCSID("$OpenBSD: session.c,v 1.46 2001/01/04 22:41:03 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: 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;
1.47 ! markus 496: /* Set interactive/non-interactive mode. */
! 497: packet_set_interactive(s->display);
1.1 markus 498: #ifdef USE_PIPES
499: /* We are the parent. Close the child sides of the pipes. */
500: close(pin[0]);
501: close(pout[1]);
502: close(perr[1]);
503:
1.2 markus 504: if (compat20) {
1.7 markus 505: session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
1.2 markus 506: } else {
507: /* Enter the interactive session. */
508: server_loop(pid, pin[1], pout[0], perr[0]);
509: /* server_loop has closed pin[1], pout[1], and perr[1]. */
510: }
1.1 markus 511: #else /* USE_PIPES */
512: /* We are the parent. Close the child sides of the socket pairs. */
513: close(inout[0]);
514: close(err[0]);
515:
516: /*
517: * Enter the interactive session. Note: server_loop must be able to
518: * handle the case that fdin and fdout are the same.
519: */
1.2 markus 520: if (compat20) {
1.7 markus 521: session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
1.2 markus 522: } else {
523: server_loop(pid, inout[1], inout[1], err[1]);
524: /* server_loop has closed inout[1] and err[1]. */
525: }
1.1 markus 526: #endif /* USE_PIPES */
527: }
528:
529: /*
530: * This is called to fork and execute a command when we have a tty. This
531: * will call do_child from the child, and server_loop from the parent after
532: * setting up file descriptors, controlling tty, updating wtmp, utmp,
533: * lastlog, and other such operations.
534: */
1.4 markus 535: void
1.1 markus 536: do_exec_pty(Session *s, const char *command, struct passwd * pw)
537: {
538: int fdout, ptyfd, ttyfd, ptymaster;
539: pid_t pid;
540:
541: if (s == NULL)
542: fatal("do_exec_pty: no session");
543: ptyfd = s->ptyfd;
544: ttyfd = s->ttyfd;
545:
546: /* Fork the child. */
547: if ((pid = fork()) == 0) {
1.24 markus 548: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 549: log_init(__progname, options.log_level, options.log_facility, log_stderr);
550:
551: /* Close the master side of the pseudo tty. */
552: close(ptyfd);
553:
554: /* Make the pseudo tty our controlling tty. */
555: pty_make_controlling_tty(&ttyfd, s->tty);
556:
557: /* Redirect stdin from the pseudo tty. */
558: if (dup2(ttyfd, fileno(stdin)) < 0)
559: error("dup2 stdin failed: %.100s", strerror(errno));
560:
561: /* Redirect stdout to the pseudo tty. */
562: if (dup2(ttyfd, fileno(stdout)) < 0)
563: error("dup2 stdin failed: %.100s", strerror(errno));
564:
565: /* Redirect stderr to the pseudo tty. */
566: if (dup2(ttyfd, fileno(stderr)) < 0)
567: error("dup2 stdin failed: %.100s", strerror(errno));
568:
569: /* Close the extra descriptor for the pseudo tty. */
570: close(ttyfd);
571:
1.24 markus 572: /* record login, etc. similar to login(1) */
1.41 markus 573: if (!(options.use_login && command == NULL))
574: do_login(s, command);
1.1 markus 575:
576: /* Do common processing for the child, such as execing the command. */
1.14 deraadt 577: do_child(command, pw, s->term, s->display, s->auth_proto,
578: s->auth_data, s->tty);
1.1 markus 579: /* NOTREACHED */
580: }
581: if (pid < 0)
582: packet_disconnect("fork failed: %.100s", strerror(errno));
583: s->pid = pid;
584:
585: /* Parent. Close the slave side of the pseudo tty. */
586: close(ttyfd);
587:
588: /*
589: * Create another descriptor of the pty master side for use as the
590: * standard input. We could use the original descriptor, but this
591: * simplifies code in server_loop. The descriptor is bidirectional.
592: */
593: fdout = dup(ptyfd);
594: if (fdout < 0)
595: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
596:
597: /* we keep a reference to the pty master */
598: ptymaster = dup(ptyfd);
599: if (ptymaster < 0)
600: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
601: s->ptymaster = ptymaster;
602:
603: /* Enter interactive session. */
1.47 ! markus 604: packet_set_interactive(1);
1.2 markus 605: if (compat20) {
606: session_set_fds(s, ptyfd, fdout, -1);
607: } else {
608: server_loop(pid, ptyfd, fdout, -1);
609: /* server_loop _has_ closed ptyfd and fdout. */
610: session_pty_cleanup(s);
1.24 markus 611: }
612: }
613:
1.25 markus 614: const char *
615: get_remote_name_or_ip(void)
616: {
617: static const char *remote = "";
618: if (utmp_len > 0)
619: remote = get_canonical_hostname();
620: if (utmp_len == 0 || strlen(remote) > utmp_len)
621: remote = get_remote_ipaddr();
622: return remote;
623: }
624:
1.24 markus 625: /* administrative, login(1)-like work */
626: void
1.41 markus 627: do_login(Session *s, const char *command)
1.24 markus 628: {
629: FILE *f;
630: char *time_string;
631: char buf[256];
1.35 markus 632: char hostname[MAXHOSTNAMELEN];
1.24 markus 633: socklen_t fromlen;
634: struct sockaddr_storage from;
635: struct stat st;
636: time_t last_login_time;
637: struct passwd * pw = s->pw;
638: pid_t pid = getpid();
639:
640: /*
641: * Get IP address of client. If the connection is not a socket, let
642: * the address be 0.0.0.0.
643: */
644: memset(&from, 0, sizeof(from));
645: if (packet_connection_is_on_socket()) {
646: fromlen = sizeof(from);
647: if (getpeername(packet_get_connection_in(),
648: (struct sockaddr *) & from, &fromlen) < 0) {
649: debug("getpeername: %.100s", strerror(errno));
650: fatal_cleanup();
651: }
652: }
1.25 markus 653:
1.35 markus 654: /* Get the time and hostname when the user last logged in. */
1.36 markus 655: hostname[0] = '\0';
1.35 markus 656: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
657: hostname, sizeof(hostname));
658:
1.24 markus 659: /* Record that there was a login on that tty from the remote host. */
660: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.25 markus 661: get_remote_name_or_ip(), (struct sockaddr *)&from);
1.24 markus 662:
1.41 markus 663: /* Done if .hushlogin exists or a command given. */
664: if (command != NULL)
665: return;
1.24 markus 666: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
1.28 millert 667: #ifdef HAVE_LOGIN_CAP
668: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
669: #else
1.24 markus 670: if (stat(buf, &st) >= 0)
1.28 millert 671: #endif
1.24 markus 672: return;
673: if (last_login_time != 0) {
674: time_string = ctime(&last_login_time);
675: if (strchr(time_string, '\n'))
676: *strchr(time_string, '\n') = 0;
1.40 markus 677: if (strcmp(hostname, "") == 0)
1.24 markus 678: printf("Last login: %s\r\n", time_string);
679: else
1.36 markus 680: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 681: }
682: if (options.print_motd) {
1.28 millert 683: #ifdef HAVE_LOGIN_CAP
684: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
685: "/etc/motd"), "r");
686: #else
1.24 markus 687: f = fopen("/etc/motd", "r");
1.28 millert 688: #endif
1.24 markus 689: if (f) {
690: while (fgets(buf, sizeof(buf), f))
691: fputs(buf, stdout);
692: fclose(f);
693: }
1.2 markus 694: }
1.1 markus 695: }
696:
697: /*
698: * Sets the value of the given variable in the environment. If the variable
699: * already exists, its value is overriden.
700: */
1.4 markus 701: void
1.45 markus 702: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 703: const char *value)
704: {
1.45 markus 705: u_int i, namelen;
1.1 markus 706: char **env;
707:
708: /*
709: * Find the slot where the value should be stored. If the variable
710: * already exists, we reuse the slot; otherwise we append a new slot
711: * at the end of the array, expanding if necessary.
712: */
713: env = *envp;
714: namelen = strlen(name);
715: for (i = 0; env[i]; i++)
716: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
717: break;
718: if (env[i]) {
719: /* Reuse the slot. */
720: xfree(env[i]);
721: } else {
722: /* New variable. Expand if necessary. */
723: if (i >= (*envsizep) - 1) {
724: (*envsizep) += 50;
725: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
726: }
727: /* Need to set the NULL pointer at end of array beyond the new slot. */
728: env[i + 1] = NULL;
729: }
730:
731: /* Allocate space and format the variable in the appropriate slot. */
732: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
733: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
734: }
735:
736: /*
737: * Reads environment variables from the given file and adds/overrides them
738: * into the environment. If the file does not exist, this does nothing.
739: * Otherwise, it must consist of empty lines, comments (line starts with '#')
740: * and assignments of the form name=value. No other forms are allowed.
741: */
1.4 markus 742: void
1.45 markus 743: read_environment_file(char ***env, u_int *envsize,
1.1 markus 744: const char *filename)
745: {
746: FILE *f;
747: char buf[4096];
748: char *cp, *value;
749:
750: f = fopen(filename, "r");
751: if (!f)
752: return;
753:
754: while (fgets(buf, sizeof(buf), f)) {
755: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
756: ;
757: if (!*cp || *cp == '#' || *cp == '\n')
758: continue;
759: if (strchr(cp, '\n'))
760: *strchr(cp, '\n') = '\0';
761: value = strchr(cp, '=');
762: if (value == NULL) {
763: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
764: continue;
765: }
1.14 deraadt 766: /*
767: * Replace the equals sign by nul, and advance value to
768: * the value string.
769: */
1.1 markus 770: *value = '\0';
771: value++;
772: child_set_env(env, envsize, cp, value);
773: }
774: fclose(f);
775: }
776:
777: /*
778: * Performs common processing for the child, such as setting up the
779: * environment, closing extra file descriptors, setting the user and group
780: * ids, and executing the command or shell.
781: */
1.4 markus 782: void
1.1 markus 783: do_child(const char *command, struct passwd * pw, const char *term,
784: const char *display, const char *auth_proto,
785: const char *auth_data, const char *ttyname)
786: {
1.32 markus 787: const char *shell, *hostname = NULL, *cp = NULL;
1.1 markus 788: char buf[256];
1.16 markus 789: char cmd[1024];
1.27 millert 790: FILE *f = NULL;
1.45 markus 791: u_int envsize, i;
1.1 markus 792: char **env;
793: extern char **environ;
794: struct stat st;
795: char *argv[10];
1.17 markus 796:
797: /* login(1) is only called if we execute the login shell */
798: if (options.use_login && command != NULL)
799: options.use_login = 0;
1.1 markus 800:
1.27 millert 801: if (!options.use_login) {
1.28 millert 802: #ifdef HAVE_LOGIN_CAP
803: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
804: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
805: _PATH_NOLOGIN), "r");
806: #else
1.27 millert 807: if (pw->pw_uid)
808: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 809: #endif
1.27 millert 810: if (f) {
811: /* /etc/nologin exists. Print its contents and exit. */
812: while (fgets(buf, sizeof(buf), f))
813: fputs(buf, stderr);
814: fclose(f);
1.1 markus 815: exit(254);
1.27 millert 816: }
1.1 markus 817: }
1.28 millert 818: /* Set login name, uid, gid, and groups. */
1.1 markus 819: /* Login(1) does this as well, and it needs uid 0 for the "-h"
820: switch, so we let login(1) to this for us. */
821: if (!options.use_login) {
822: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 823: #ifdef HAVE_LOGIN_CAP
824: if (setusercontext(lc, pw, pw->pw_uid,
825: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
826: perror("unable to set user context");
827: exit(1);
828:
829: }
830: #else
831: if (setlogin(pw->pw_name) < 0)
832: error("setlogin failed: %s", strerror(errno));
1.1 markus 833: if (setgid(pw->pw_gid) < 0) {
834: perror("setgid");
835: exit(1);
836: }
837: /* Initialize the group list. */
838: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
839: perror("initgroups");
840: exit(1);
841: }
842: endgrent();
843:
844: /* Permanently switch to the desired uid. */
845: permanently_set_uid(pw->pw_uid);
1.28 millert 846: #endif
1.1 markus 847: }
848: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 849: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 850: }
851: /*
852: * Get the shell from the password data. An empty shell field is
853: * legal, and means /bin/sh.
854: */
855: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 856: #ifdef HAVE_LOGIN_CAP
857: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
858: #endif
1.1 markus 859:
860: #ifdef AFS
861: /* Try to get AFS tokens for the local cell. */
862: if (k_hasafs()) {
863: char cell[64];
864:
865: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
866: krb_afslog(cell, 0);
867:
868: krb_afslog(0, 0);
869: }
870: #endif /* AFS */
871:
872: /* Initialize the environment. */
873: envsize = 100;
874: env = xmalloc(envsize * sizeof(char *));
875: env[0] = NULL;
876:
877: if (!options.use_login) {
878: /* Set basic environment. */
879: child_set_env(&env, &envsize, "USER", pw->pw_name);
880: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
881: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 882: #ifdef HAVE_LOGIN_CAP
1.29 millert 883: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
884: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 885: #else
1.29 millert 886: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 887: #endif
1.1 markus 888:
889: snprintf(buf, sizeof buf, "%.200s/%.50s",
890: _PATH_MAILDIR, pw->pw_name);
891: child_set_env(&env, &envsize, "MAIL", buf);
892:
893: /* Normal systems set SHELL by default. */
894: child_set_env(&env, &envsize, "SHELL", shell);
895: }
896: if (getenv("TZ"))
897: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
898:
899: /* Set custom environment options from RSA authentication. */
900: while (custom_environment) {
901: struct envstring *ce = custom_environment;
902: char *s = ce->s;
903: int i;
904: for (i = 0; s[i] != '=' && s[i]; i++);
905: if (s[i] == '=') {
906: s[i] = 0;
907: child_set_env(&env, &envsize, s, s + i + 1);
908: }
909: custom_environment = ce->next;
910: xfree(ce->s);
911: xfree(ce);
912: }
913:
914: snprintf(buf, sizeof buf, "%.50s %d %d",
915: get_remote_ipaddr(), get_remote_port(), get_local_port());
916: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
917:
918: if (ttyname)
919: child_set_env(&env, &envsize, "SSH_TTY", ttyname);
920: if (term)
921: child_set_env(&env, &envsize, "TERM", term);
922: if (display)
923: child_set_env(&env, &envsize, "DISPLAY", display);
1.34 markus 924: if (original_command)
925: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
926: original_command);
1.1 markus 927:
928: #ifdef KRB4
929: {
930: extern char *ticket;
931:
932: if (ticket)
933: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
934: }
935: #endif /* KRB4 */
936:
937: if (xauthfile)
938: child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
939: if (auth_get_socket_name() != NULL)
940: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
941: auth_get_socket_name());
942:
943: /* read $HOME/.ssh/environment. */
944: if (!options.use_login) {
1.14 deraadt 945: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
946: pw->pw_dir);
1.1 markus 947: read_environment_file(&env, &envsize, buf);
948: }
949: if (debug_flag) {
950: /* dump the environment */
951: fprintf(stderr, "Environment:\n");
952: for (i = 0; env[i]; i++)
953: fprintf(stderr, " %.200s\n", env[i]);
954: }
1.26 millert 955: /* we have to stash the hostname before we close our socket. */
956: if (options.use_login)
957: hostname = get_remote_name_or_ip();
1.1 markus 958: /*
959: * Close the connection descriptors; note that this is the child, and
960: * the server will still have the socket open, and it is important
961: * that we do not shutdown it. Note that the descriptors cannot be
962: * closed before building the environment, as we call
963: * get_remote_ipaddr there.
964: */
965: if (packet_get_connection_in() == packet_get_connection_out())
966: close(packet_get_connection_in());
967: else {
968: close(packet_get_connection_in());
969: close(packet_get_connection_out());
970: }
971: /*
972: * Close all descriptors related to channels. They will still remain
973: * open in the parent.
974: */
975: /* XXX better use close-on-exec? -markus */
976: channel_close_all();
977:
978: /*
979: * Close any extra file descriptors. Note that there may still be
980: * descriptors left by system functions. They will be closed later.
981: */
982: endpwent();
983:
984: /*
985: * Close any extra open file descriptors so that we don\'t have them
986: * hanging around in clients. Note that we want to do this after
987: * initgroups, because at least on Solaris 2.3 it leaves file
988: * descriptors open.
989: */
990: for (i = 3; i < 64; i++)
991: close(i);
992:
993: /* Change current directory to the user\'s home directory. */
1.28 millert 994: if (chdir(pw->pw_dir) < 0) {
1.1 markus 995: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
996: pw->pw_dir, strerror(errno));
1.28 millert 997: #ifdef HAVE_LOGIN_CAP
998: if (login_getcapbool(lc, "requirehome", 0))
999: exit(1);
1000: #endif
1001: }
1.1 markus 1002:
1003: /*
1004: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1005: * xauth are run in the proper environment.
1006: */
1007: environ = env;
1008:
1009: /*
1010: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1011: * in this order).
1012: */
1013: if (!options.use_login) {
1014: if (stat(SSH_USER_RC, &st) >= 0) {
1015: if (debug_flag)
1.46 markus 1016: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, SSH_USER_RC);
1.1 markus 1017:
1.46 markus 1018: f = popen(_PATH_BSHELL " " SSH_USER_RC, "w");
1.1 markus 1019: if (f) {
1020: if (auth_proto != NULL && auth_data != NULL)
1021: fprintf(f, "%s %s\n", auth_proto, auth_data);
1022: pclose(f);
1023: } else
1024: fprintf(stderr, "Could not run %s\n", SSH_USER_RC);
1025: } else if (stat(SSH_SYSTEM_RC, &st) >= 0) {
1026: if (debug_flag)
1.46 markus 1027: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, SSH_SYSTEM_RC);
1.1 markus 1028:
1.46 markus 1029: f = popen(_PATH_BSHELL " " SSH_SYSTEM_RC, "w");
1.1 markus 1030: if (f) {
1031: if (auth_proto != NULL && auth_data != NULL)
1032: fprintf(f, "%s %s\n", auth_proto, auth_data);
1033: pclose(f);
1034: } else
1035: fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC);
1.16 markus 1036: } else if (options.xauth_location != NULL) {
1.1 markus 1037: /* Add authority data to .Xauthority if appropriate. */
1038: if (auth_proto != NULL && auth_data != NULL) {
1.13 markus 1039: char *screen = strchr(display, ':');
1040: if (debug_flag) {
1.14 deraadt 1041: fprintf(stderr,
1042: "Running %.100s add %.100s %.100s %.100s\n",
1.16 markus 1043: options.xauth_location, display,
1044: auth_proto, auth_data);
1.13 markus 1045: if (screen != NULL)
1.14 deraadt 1046: fprintf(stderr,
1047: "Adding %.*s/unix%s %s %s\n",
1.30 deraadt 1048: (int)(screen-display), display,
1.14 deraadt 1049: screen, auth_proto, auth_data);
1.13 markus 1050: }
1.16 markus 1051: snprintf(cmd, sizeof cmd, "%s -q -",
1052: options.xauth_location);
1053: f = popen(cmd, "w");
1.1 markus 1054: if (f) {
1.14 deraadt 1055: fprintf(f, "add %s %s %s\n", display,
1056: auth_proto, auth_data);
1.13 markus 1057: if (screen != NULL)
1058: fprintf(f, "add %.*s/unix%s %s %s\n",
1.30 deraadt 1059: (int)(screen-display), display,
1.14 deraadt 1060: screen, auth_proto, auth_data);
1.1 markus 1061: pclose(f);
1.16 markus 1062: } else {
1063: fprintf(stderr, "Could not run %s\n",
1064: cmd);
1065: }
1.1 markus 1066: }
1067: }
1068: /* Get the last component of the shell name. */
1069: cp = strrchr(shell, '/');
1070: if (cp)
1071: cp++;
1072: else
1073: cp = shell;
1074: }
1075: /*
1076: * If we have no command, execute the shell. In this case, the shell
1077: * name to be passed in argv[0] is preceded by '-' to indicate that
1078: * this is a login shell.
1079: */
1080: if (!command) {
1081: if (!options.use_login) {
1082: char buf[256];
1083:
1084: /*
1085: * Check for mail if we have a tty and it was enabled
1086: * in server options.
1087: */
1088: if (ttyname && options.check_mail) {
1089: char *mailbox;
1090: struct stat mailstat;
1091: mailbox = getenv("MAIL");
1092: if (mailbox != NULL) {
1.14 deraadt 1093: if (stat(mailbox, &mailstat) != 0 ||
1094: mailstat.st_size == 0)
1.1 markus 1095: printf("No mail.\n");
1096: else if (mailstat.st_mtime < mailstat.st_atime)
1097: printf("You have mail.\n");
1098: else
1099: printf("You have new mail.\n");
1100: }
1101: }
1102: /* Start the shell. Set initial character to '-'. */
1103: buf[0] = '-';
1104: strncpy(buf + 1, cp, sizeof(buf) - 1);
1105: buf[sizeof(buf) - 1] = 0;
1106:
1107: /* Execute the shell. */
1108: argv[0] = buf;
1109: argv[1] = NULL;
1110: execve(shell, argv, env);
1111:
1112: /* Executing the shell failed. */
1113: perror(shell);
1114: exit(1);
1115:
1116: } else {
1117: /* Launch login(1). */
1118:
1.26 millert 1119: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1120: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1121:
1122: /* Login couldn't be executed, die. */
1123:
1124: perror("login");
1125: exit(1);
1126: }
1127: }
1128: /*
1129: * Execute the command using the user's shell. This uses the -c
1130: * option to execute the command.
1131: */
1132: argv[0] = (char *) cp;
1133: argv[1] = "-c";
1134: argv[2] = (char *) command;
1135: argv[3] = NULL;
1136: execve(shell, argv, env);
1137: perror(shell);
1138: exit(1);
1139: }
1140:
1141: Session *
1142: session_new(void)
1143: {
1144: int i;
1145: static int did_init = 0;
1146: if (!did_init) {
1147: debug("session_new: init");
1148: for(i = 0; i < MAX_SESSIONS; i++) {
1149: sessions[i].used = 0;
1150: sessions[i].self = i;
1151: }
1152: did_init = 1;
1153: }
1154: for(i = 0; i < MAX_SESSIONS; i++) {
1155: Session *s = &sessions[i];
1156: if (! s->used) {
1157: s->pid = 0;
1.7 markus 1158: s->extended = 0;
1.1 markus 1159: s->chanid = -1;
1160: s->ptyfd = -1;
1161: s->ttyfd = -1;
1162: s->term = NULL;
1163: s->pw = NULL;
1164: s->display = NULL;
1165: s->screen = 0;
1166: s->auth_data = NULL;
1167: s->auth_proto = NULL;
1168: s->used = 1;
1.7 markus 1169: s->pw = NULL;
1.1 markus 1170: debug("session_new: session %d", i);
1171: return s;
1172: }
1173: }
1174: return NULL;
1175: }
1176:
1177: void
1178: session_dump(void)
1179: {
1180: int i;
1181: for(i = 0; i < MAX_SESSIONS; i++) {
1182: Session *s = &sessions[i];
1183: debug("dump: used %d session %d %p channel %d pid %d",
1184: s->used,
1185: s->self,
1186: s,
1187: s->chanid,
1188: s->pid);
1189: }
1190: }
1191:
1.2 markus 1192: int
1193: session_open(int chanid)
1194: {
1195: Session *s = session_new();
1196: debug("session_open: channel %d", chanid);
1197: if (s == NULL) {
1198: error("no more sessions");
1199: return 0;
1200: }
1.7 markus 1201: s->pw = auth_get_user();
1202: if (s->pw == NULL)
1203: fatal("no user for session %i", s->self);
1.2 markus 1204: debug("session_open: session %d: link with channel %d", s->self, chanid);
1205: s->chanid = chanid;
1206: return 1;
1207: }
1208:
1209: Session *
1210: session_by_channel(int id)
1211: {
1212: int i;
1213: for(i = 0; i < MAX_SESSIONS; i++) {
1214: Session *s = &sessions[i];
1215: if (s->used && s->chanid == id) {
1216: debug("session_by_channel: session %d channel %d", i, id);
1217: return s;
1218: }
1219: }
1220: debug("session_by_channel: unknown channel %d", id);
1221: session_dump();
1222: return NULL;
1223: }
1224:
1225: Session *
1226: session_by_pid(pid_t pid)
1227: {
1228: int i;
1229: debug("session_by_pid: pid %d", pid);
1230: for(i = 0; i < MAX_SESSIONS; i++) {
1231: Session *s = &sessions[i];
1232: if (s->used && s->pid == pid)
1233: return s;
1234: }
1235: error("session_by_pid: unknown pid %d", pid);
1236: session_dump();
1237: return NULL;
1238: }
1239:
1240: int
1241: session_window_change_req(Session *s)
1242: {
1243: s->col = packet_get_int();
1244: s->row = packet_get_int();
1245: s->xpixel = packet_get_int();
1246: s->ypixel = packet_get_int();
1.3 markus 1247: packet_done();
1.2 markus 1248: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1249: return 1;
1250: }
1251:
1252: int
1253: session_pty_req(Session *s)
1254: {
1.45 markus 1255: u_int len;
1.3 markus 1256: char *term_modes; /* encoded terminal modes */
1.2 markus 1257:
1.19 markus 1258: if (no_pty_flag)
1259: return 0;
1.2 markus 1260: if (s->ttyfd != -1)
1.3 markus 1261: return 0;
1.2 markus 1262: s->term = packet_get_string(&len);
1263: s->col = packet_get_int();
1264: s->row = packet_get_int();
1265: s->xpixel = packet_get_int();
1266: s->ypixel = packet_get_int();
1.3 markus 1267: term_modes = packet_get_string(&len);
1268: packet_done();
1.2 markus 1269:
1270: if (strcmp(s->term, "") == 0) {
1271: xfree(s->term);
1272: s->term = NULL;
1273: }
1274: /* Allocate a pty and open it. */
1275: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1276: xfree(s->term);
1277: s->term = NULL;
1278: s->ptyfd = -1;
1279: s->ttyfd = -1;
1280: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1281: xfree(term_modes);
1282: return 0;
1.2 markus 1283: }
1284: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1285: /*
1286: * Add a cleanup function to clear the utmp entry and record logout
1287: * time in case we call fatal() (e.g., the connection gets closed).
1288: */
1289: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1290: pty_setowner(s->pw, s->tty);
1291: /* Get window size from the packet. */
1292: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1293:
1.9 markus 1294: session_proctitle(s);
1295:
1.3 markus 1296: /* XXX parse and set terminal modes */
1297: xfree(term_modes);
1.2 markus 1298: return 1;
1299: }
1300:
1.7 markus 1301: int
1302: session_subsystem_req(Session *s)
1303: {
1.45 markus 1304: u_int len;
1.7 markus 1305: int success = 0;
1306: char *subsys = packet_get_string(&len);
1.18 jakob 1307: int i;
1.7 markus 1308:
1309: packet_done();
1310: log("subsystem request for %s", subsys);
1.18 jakob 1311:
1312: for (i = 0; i < options.num_subsystems; i++) {
1313: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1314: debug("subsystem: exec() %s", options.subsystem_command[i]);
1315: do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1316: success = 1;
1317: }
1318: }
1319:
1320: if (!success)
1321: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1322:
1323: xfree(subsys);
1324: return success;
1325: }
1326:
1327: int
1328: session_x11_req(Session *s)
1329: {
1.33 markus 1330: int fd;
1.22 deraadt 1331: if (no_x11_forwarding_flag) {
1.19 markus 1332: debug("X11 forwarding disabled in user configuration file.");
1333: return 0;
1334: }
1.7 markus 1335: if (!options.x11_forwarding) {
1336: debug("X11 forwarding disabled in server configuration file.");
1337: return 0;
1338: }
1339: if (xauthfile != NULL) {
1340: debug("X11 fwd already started.");
1341: return 0;
1342: }
1343:
1344: debug("Received request for X11 forwarding with auth spoofing.");
1345: if (s->display != NULL)
1346: packet_disconnect("Protocol error: X11 display already set.");
1347:
1348: s->single_connection = packet_get_char();
1349: s->auth_proto = packet_get_string(NULL);
1350: s->auth_data = packet_get_string(NULL);
1351: s->screen = packet_get_int();
1352: packet_done();
1353:
1354: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1355: if (s->display == NULL) {
1356: xfree(s->auth_proto);
1357: xfree(s->auth_data);
1358: return 0;
1359: }
1360: xauthfile = xmalloc(MAXPATHLEN);
1361: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1362: temporarily_use_uid(s->pw->pw_uid);
1363: if (mkdtemp(xauthfile) == NULL) {
1364: restore_uid();
1365: error("private X11 dir: mkdtemp %s failed: %s",
1366: xauthfile, strerror(errno));
1367: xfree(xauthfile);
1368: xauthfile = NULL;
1369: xfree(s->auth_proto);
1370: xfree(s->auth_data);
1371: /* XXXX remove listening channels */
1372: return 0;
1373: }
1374: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 1375: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1376: if (fd >= 0)
1377: close(fd);
1.7 markus 1378: restore_uid();
1379: fatal_add_cleanup(xauthfile_cleanup_proc, s);
1380: return 1;
1381: }
1382:
1.19 markus 1383: int
1384: session_shell_req(Session *s)
1385: {
1386: /* if forced_command == NULL, the shell is execed */
1387: char *shell = forced_command;
1388: packet_done();
1389: s->extended = 1;
1390: if (s->ttyfd == -1)
1391: do_exec_no_pty(s, shell, s->pw);
1392: else
1393: do_exec_pty(s, shell, s->pw);
1394: return 1;
1395: }
1396:
1397: int
1398: session_exec_req(Session *s)
1399: {
1.45 markus 1400: u_int len;
1.19 markus 1401: char *command = packet_get_string(&len);
1402: packet_done();
1403: if (forced_command) {
1.34 markus 1404: original_command = command;
1.19 markus 1405: command = forced_command;
1406: debug("Forced command '%.500s'", forced_command);
1407: }
1408: s->extended = 1;
1409: if (s->ttyfd == -1)
1410: do_exec_no_pty(s, command, s->pw);
1411: else
1412: do_exec_pty(s, command, s->pw);
1413: if (forced_command == NULL)
1414: xfree(command);
1415: return 1;
1416: }
1417:
1.43 markus 1418: int
1419: session_auth_agent_req(Session *s)
1420: {
1421: static int called = 0;
1422: packet_done();
1.44 markus 1423: if (no_agent_forwarding_flag) {
1424: debug("session_auth_agent_req: no_agent_forwarding_flag");
1425: return 0;
1426: }
1.43 markus 1427: if (called) {
1428: return 0;
1429: } else {
1430: called = 1;
1431: return auth_input_request_forwarding(s->pw);
1432: }
1433: }
1434:
1.2 markus 1435: void
1436: session_input_channel_req(int id, void *arg)
1437: {
1.45 markus 1438: u_int len;
1.2 markus 1439: int reply;
1440: int success = 0;
1441: char *rtype;
1442: Session *s;
1443: Channel *c;
1444:
1445: rtype = packet_get_string(&len);
1446: reply = packet_get_char();
1447:
1448: s = session_by_channel(id);
1449: if (s == NULL)
1450: fatal("session_input_channel_req: channel %d: no session", id);
1451: c = channel_lookup(id);
1452: if (c == NULL)
1453: fatal("session_input_channel_req: channel %d: bad channel", id);
1454:
1455: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1456: s->self, id, rtype, reply);
1457:
1458: /*
1459: * a session is in LARVAL state until a shell
1460: * or programm is executed
1461: */
1462: if (c->type == SSH_CHANNEL_LARVAL) {
1463: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1464: success = session_shell_req(s);
1.2 markus 1465: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1466: success = session_exec_req(s);
1.2 markus 1467: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1468: success = session_pty_req(s);
1.7 markus 1469: } else if (strcmp(rtype, "x11-req") == 0) {
1470: success = session_x11_req(s);
1.43 markus 1471: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1472: success = session_auth_agent_req(s);
1.7 markus 1473: } else if (strcmp(rtype, "subsystem") == 0) {
1474: success = session_subsystem_req(s);
1.2 markus 1475: }
1476: }
1477: if (strcmp(rtype, "window-change") == 0) {
1478: success = session_window_change_req(s);
1479: }
1480:
1481: if (reply) {
1482: packet_start(success ?
1483: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1484: packet_put_int(c->remote_id);
1485: packet_send();
1486: }
1487: xfree(rtype);
1488: }
1489:
1490: void
1491: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1492: {
1493: if (!compat20)
1494: fatal("session_set_fds: called for proto != 2.0");
1495: /*
1496: * now that have a child and a pipe to the child,
1497: * we can activate our channel and register the fd's
1498: */
1499: if (s->chanid == -1)
1500: fatal("no channel for session %d", s->self);
1501: channel_set_fds(s->chanid,
1502: fdout, fdin, fderr,
1.42 markus 1503: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1504: 1);
1.2 markus 1505: }
1506:
1.1 markus 1507: void
1508: session_pty_cleanup(Session *s)
1509: {
1510: if (s == NULL || s->ttyfd == -1)
1511: return;
1512:
1513: debug("session_pty_cleanup: session %i release %s", s->self, s->tty);
1514:
1515: /* Cancel the cleanup function. */
1516: fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1517:
1518: /* Record that the user has logged out. */
1519: record_logout(s->pid, s->tty);
1520:
1521: /* Release the pseudo-tty. */
1522: pty_release(s->tty);
1523:
1524: /*
1525: * Close the server side of the socket pairs. We must do this after
1526: * the pty cleanup, so that another process doesn't get this pty
1527: * while we're still cleaning up.
1528: */
1529: if (close(s->ptymaster) < 0)
1530: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1531: }
1532:
1533: void
1534: session_exit_message(Session *s, int status)
1535: {
1536: Channel *c;
1537: if (s == NULL)
1538: fatal("session_close: no session");
1539: c = channel_lookup(s->chanid);
1540: if (c == NULL)
1541: fatal("session_close: session %d: no channel %d",
1542: s->self, s->chanid);
1543: debug("session_exit_message: session %d channel %d pid %d",
1544: s->self, s->chanid, s->pid);
1545:
1546: if (WIFEXITED(status)) {
1547: channel_request_start(s->chanid,
1548: "exit-status", 0);
1549: packet_put_int(WEXITSTATUS(status));
1550: packet_send();
1551: } else if (WIFSIGNALED(status)) {
1552: channel_request_start(s->chanid,
1553: "exit-signal", 0);
1554: packet_put_int(WTERMSIG(status));
1555: packet_put_char(WCOREDUMP(status));
1556: packet_put_cstring("");
1557: packet_put_cstring("");
1558: packet_send();
1559: } else {
1560: /* Some weird exit cause. Just exit. */
1561: packet_disconnect("wait returned status %04x.", status);
1562: }
1563:
1564: /* disconnect channel */
1565: debug("session_exit_message: release channel %d", s->chanid);
1566: channel_cancel_cleanup(s->chanid);
1.5 markus 1567: /*
1568: * emulate a write failure with 'chan_write_failed', nobody will be
1569: * interested in data we write.
1570: * Note that we must not call 'chan_read_failed', since there could
1571: * be some more data waiting in the pipe.
1572: */
1.8 markus 1573: if (c->ostate != CHAN_OUTPUT_CLOSED)
1574: chan_write_failed(c);
1.2 markus 1575: s->chanid = -1;
1576: }
1577:
1578: void
1579: session_free(Session *s)
1580: {
1581: debug("session_free: session %d pid %d", s->self, s->pid);
1582: if (s->term)
1583: xfree(s->term);
1584: if (s->display)
1585: xfree(s->display);
1586: if (s->auth_data)
1587: xfree(s->auth_data);
1588: if (s->auth_proto)
1589: xfree(s->auth_proto);
1590: s->used = 0;
1591: }
1592:
1593: void
1594: session_close(Session *s)
1595: {
1596: session_pty_cleanup(s);
1597: session_free(s);
1.9 markus 1598: session_proctitle(s);
1.2 markus 1599: }
1600:
1601: void
1602: session_close_by_pid(pid_t pid, int status)
1603: {
1604: Session *s = session_by_pid(pid);
1605: if (s == NULL) {
1606: debug("session_close_by_pid: no session for pid %d", s->pid);
1607: return;
1608: }
1609: if (s->chanid != -1)
1610: session_exit_message(s, status);
1611: session_close(s);
1612: }
1613:
1614: /*
1615: * this is called when a channel dies before
1616: * the session 'child' itself dies
1617: */
1618: void
1619: session_close_by_channel(int id, void *arg)
1620: {
1621: Session *s = session_by_channel(id);
1622: if (s == NULL) {
1623: debug("session_close_by_channel: no session for channel %d", id);
1624: return;
1625: }
1626: /* disconnect channel */
1627: channel_cancel_cleanup(s->chanid);
1628: s->chanid = -1;
1629:
1630: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1631: if (s->pid == 0) {
1632: /* close session immediately */
1633: session_close(s);
1634: } else {
1635: /* notify child, delay session cleanup */
1636: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1637: error("session_close_by_channel: kill %d: %s",
1638: s->pid, strerror(errno));
1639: }
1.9 markus 1640: }
1641:
1642: char *
1643: session_tty_list(void)
1644: {
1645: static char buf[1024];
1646: int i;
1647: buf[0] = '\0';
1648: for(i = 0; i < MAX_SESSIONS; i++) {
1649: Session *s = &sessions[i];
1650: if (s->used && s->ttyfd != -1) {
1651: if (buf[0] != '\0')
1652: strlcat(buf, ",", sizeof buf);
1653: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1654: }
1655: }
1656: if (buf[0] == '\0')
1657: strlcpy(buf, "notty", sizeof buf);
1658: return buf;
1659: }
1660:
1661: void
1662: session_proctitle(Session *s)
1663: {
1664: if (s->pw == NULL)
1665: error("no user for session %d", s->self);
1666: else
1667: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1668: }
1669:
1670: void
1671: do_authenticated2(void)
1672: {
1.28 millert 1673: struct passwd *pw;
1674:
1.2 markus 1675: /*
1676: * Cancel the alarm we set to limit the time taken for
1677: * authentication.
1678: */
1679: alarm(0);
1.23 deraadt 1680: if (startup_pipe != -1) {
1681: close(startup_pipe);
1682: startup_pipe = -1;
1683: }
1.28 millert 1684: #ifdef HAVE_LOGIN_CAP
1685: pw = auth_get_user();
1686: if ((lc = login_getclass(pw->pw_class)) == NULL) {
1687: error("unable to get login class");
1688: return;
1689: }
1690: #endif
1.2 markus 1691: server_loop2();
1.7 markus 1692: if (xauthfile)
1693: xauthfile_cleanup_proc(NULL);
1.1 markus 1694: }
![[BACK]](/icons/back.gif){kind=icon}
Return to session.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh