Annotation of src/usr.bin/ssh/session.c, Revision 1.39
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"
1.39 ! markus 36: RCSID("$OpenBSD: session.c,v 1.38 2000/10/11 20:27:23 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);
1.24 markus 92: void do_login(Session *s);
1.1 markus 93:
94: void
95: do_child(const char *command, struct passwd * pw, const char *term,
96: const char *display, const char *auth_proto,
97: const char *auth_data, const char *ttyname);
98:
99: /* import */
100: extern ServerOptions options;
101: extern char *__progname;
102: extern int log_stderr;
103: extern int debug_flag;
1.25 markus 104: extern unsigned int utmp_len;
1.1 markus 105:
1.21 markus 106: extern int startup_pipe;
107:
1.1 markus 108: /* Local Xauthority file. */
109: static char *xauthfile;
110:
1.34 markus 111: /* original command from peer. */
112: char *original_command = NULL;
113:
1.1 markus 114: /* data */
115: #define MAX_SESSIONS 10
116: Session sessions[MAX_SESSIONS];
117:
1.28 millert 118: #ifdef HAVE_LOGIN_CAP
119: static login_cap_t *lc;
120: #endif
121:
1.1 markus 122: /*
123: * Remove local Xauthority file.
124: */
125: void
126: xauthfile_cleanup_proc(void *ignore)
127: {
128: debug("xauthfile_cleanup_proc called");
129:
130: if (xauthfile != NULL) {
131: char *p;
132: unlink(xauthfile);
133: p = strrchr(xauthfile, '/');
134: if (p != NULL) {
135: *p = '\0';
136: rmdir(xauthfile);
137: }
138: xfree(xauthfile);
139: xauthfile = NULL;
140: }
141: }
142:
143: /*
144: * Function to perform cleanup if we get aborted abnormally (e.g., due to a
145: * dropped connection).
146: */
1.4 markus 147: void
1.1 markus 148: pty_cleanup_proc(void *session)
149: {
150: Session *s=session;
151: if (s == NULL)
152: fatal("pty_cleanup_proc: no session");
153: debug("pty_cleanup_proc: %s", s->tty);
154:
155: if (s->pid != 0) {
156: /* Record that the user has logged out. */
157: record_logout(s->pid, s->tty);
158: }
159:
160: /* Release the pseudo-tty. */
161: pty_release(s->tty);
162: }
163:
164: /*
165: * Prepares for an interactive session. This is called after the user has
166: * been successfully authenticated. During this message exchange, pseudo
167: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
168: * are requested, etc.
169: */
1.4 markus 170: void
1.1 markus 171: do_authenticated(struct passwd * pw)
172: {
173: Session *s;
1.33 markus 174: int type, fd;
1.1 markus 175: int compression_level = 0, enable_compression_after_reply = 0;
176: int have_pty = 0;
177: char *command;
178: int n_bytes;
179: int plen;
180: unsigned int proto_len, data_len, dlen;
181:
182: /*
183: * Cancel the alarm we set to limit the time taken for
184: * authentication.
185: */
186: alarm(0);
1.23 deraadt 187: if (startup_pipe != -1) {
188: close(startup_pipe);
189: startup_pipe = -1;
190: }
1.1 markus 191:
192: /*
193: * Inform the channel mechanism that we are the server side and that
194: * the client may request to connect to any port at all. (The user
195: * could do it anyway, and we wouldn\'t know what is permitted except
196: * by the client telling us, so we can equally well trust the client
197: * not to request anything bogus.)
198: */
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) */
575: if (command == NULL && !options.use_login)
576: do_login(s);
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
628: do_login(Session *s)
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:
664: /* Done if .hushlogin exists. */
665: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
1.28 millert 666: #ifdef HAVE_LOGIN_CAP
667: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
668: #else
1.24 markus 669: if (stat(buf, &st) >= 0)
1.28 millert 670: #endif
1.24 markus 671: return;
672: if (last_login_time != 0) {
673: time_string = ctime(&last_login_time);
674: if (strchr(time_string, '\n'))
675: *strchr(time_string, '\n') = 0;
676: if (strcmp(buf, "") == 0)
677: printf("Last login: %s\r\n", time_string);
678: else
1.36 markus 679: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 680: }
681: if (options.print_motd) {
1.28 millert 682: #ifdef HAVE_LOGIN_CAP
683: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
684: "/etc/motd"), "r");
685: #else
1.24 markus 686: f = fopen("/etc/motd", "r");
1.28 millert 687: #endif
1.24 markus 688: if (f) {
689: while (fgets(buf, sizeof(buf), f))
690: fputs(buf, stdout);
691: fclose(f);
692: }
1.2 markus 693: }
1.1 markus 694: }
695:
696: /*
697: * Sets the value of the given variable in the environment. If the variable
698: * already exists, its value is overriden.
699: */
1.4 markus 700: void
1.1 markus 701: child_set_env(char ***envp, unsigned int *envsizep, const char *name,
702: const char *value)
703: {
704: unsigned int i, namelen;
705: char **env;
706:
707: /*
708: * Find the slot where the value should be stored. If the variable
709: * already exists, we reuse the slot; otherwise we append a new slot
710: * at the end of the array, expanding if necessary.
711: */
712: env = *envp;
713: namelen = strlen(name);
714: for (i = 0; env[i]; i++)
715: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
716: break;
717: if (env[i]) {
718: /* Reuse the slot. */
719: xfree(env[i]);
720: } else {
721: /* New variable. Expand if necessary. */
722: if (i >= (*envsizep) - 1) {
723: (*envsizep) += 50;
724: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
725: }
726: /* Need to set the NULL pointer at end of array beyond the new slot. */
727: env[i + 1] = NULL;
728: }
729:
730: /* Allocate space and format the variable in the appropriate slot. */
731: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
732: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
733: }
734:
735: /*
736: * Reads environment variables from the given file and adds/overrides them
737: * into the environment. If the file does not exist, this does nothing.
738: * Otherwise, it must consist of empty lines, comments (line starts with '#')
739: * and assignments of the form name=value. No other forms are allowed.
740: */
1.4 markus 741: void
1.1 markus 742: read_environment_file(char ***env, unsigned int *envsize,
743: const char *filename)
744: {
745: FILE *f;
746: char buf[4096];
747: char *cp, *value;
748:
749: f = fopen(filename, "r");
750: if (!f)
751: return;
752:
753: while (fgets(buf, sizeof(buf), f)) {
754: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
755: ;
756: if (!*cp || *cp == '#' || *cp == '\n')
757: continue;
758: if (strchr(cp, '\n'))
759: *strchr(cp, '\n') = '\0';
760: value = strchr(cp, '=');
761: if (value == NULL) {
762: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
763: continue;
764: }
1.14 deraadt 765: /*
766: * Replace the equals sign by nul, and advance value to
767: * the value string.
768: */
1.1 markus 769: *value = '\0';
770: value++;
771: child_set_env(env, envsize, cp, value);
772: }
773: fclose(f);
774: }
775:
776: /*
777: * Performs common processing for the child, such as setting up the
778: * environment, closing extra file descriptors, setting the user and group
779: * ids, and executing the command or shell.
780: */
1.4 markus 781: void
1.1 markus 782: do_child(const char *command, struct passwd * pw, const char *term,
783: const char *display, const char *auth_proto,
784: const char *auth_data, const char *ttyname)
785: {
1.32 markus 786: const char *shell, *hostname = NULL, *cp = NULL;
1.1 markus 787: char buf[256];
1.16 markus 788: char cmd[1024];
1.27 millert 789: FILE *f = NULL;
1.1 markus 790: unsigned int envsize, i;
791: char **env;
792: extern char **environ;
793: struct stat st;
794: char *argv[10];
1.17 markus 795:
796: /* login(1) is only called if we execute the login shell */
797: if (options.use_login && command != NULL)
798: options.use_login = 0;
1.1 markus 799:
1.27 millert 800: if (!options.use_login) {
1.28 millert 801: #ifdef HAVE_LOGIN_CAP
802: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
803: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
804: _PATH_NOLOGIN), "r");
805: #else
1.27 millert 806: if (pw->pw_uid)
807: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 808: #endif
1.27 millert 809: if (f) {
810: /* /etc/nologin exists. Print its contents and exit. */
811: while (fgets(buf, sizeof(buf), f))
812: fputs(buf, stderr);
813: fclose(f);
1.1 markus 814: exit(254);
1.27 millert 815: }
1.1 markus 816: }
1.28 millert 817: /* Set login name, uid, gid, and groups. */
1.1 markus 818: /* Login(1) does this as well, and it needs uid 0 for the "-h"
819: switch, so we let login(1) to this for us. */
820: if (!options.use_login) {
821: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 822: #ifdef HAVE_LOGIN_CAP
823: if (setusercontext(lc, pw, pw->pw_uid,
824: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
825: perror("unable to set user context");
826: exit(1);
827:
828: }
829: #else
830: if (setlogin(pw->pw_name) < 0)
831: error("setlogin failed: %s", strerror(errno));
1.1 markus 832: if (setgid(pw->pw_gid) < 0) {
833: perror("setgid");
834: exit(1);
835: }
836: /* Initialize the group list. */
837: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
838: perror("initgroups");
839: exit(1);
840: }
841: endgrent();
842:
843: /* Permanently switch to the desired uid. */
844: permanently_set_uid(pw->pw_uid);
1.28 millert 845: #endif
1.1 markus 846: }
847: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 848: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 849: }
850: /*
851: * Get the shell from the password data. An empty shell field is
852: * legal, and means /bin/sh.
853: */
854: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 855: #ifdef HAVE_LOGIN_CAP
856: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
857: #endif
1.1 markus 858:
859: #ifdef AFS
860: /* Try to get AFS tokens for the local cell. */
861: if (k_hasafs()) {
862: char cell[64];
863:
864: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
865: krb_afslog(cell, 0);
866:
867: krb_afslog(0, 0);
868: }
869: #endif /* AFS */
870:
871: /* Initialize the environment. */
872: envsize = 100;
873: env = xmalloc(envsize * sizeof(char *));
874: env[0] = NULL;
875:
876: if (!options.use_login) {
877: /* Set basic environment. */
878: child_set_env(&env, &envsize, "USER", pw->pw_name);
879: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
880: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 881: #ifdef HAVE_LOGIN_CAP
1.29 millert 882: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
883: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 884: #else
1.29 millert 885: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 886: #endif
1.1 markus 887:
888: snprintf(buf, sizeof buf, "%.200s/%.50s",
889: _PATH_MAILDIR, pw->pw_name);
890: child_set_env(&env, &envsize, "MAIL", buf);
891:
892: /* Normal systems set SHELL by default. */
893: child_set_env(&env, &envsize, "SHELL", shell);
894: }
895: if (getenv("TZ"))
896: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
897:
898: /* Set custom environment options from RSA authentication. */
899: while (custom_environment) {
900: struct envstring *ce = custom_environment;
901: char *s = ce->s;
902: int i;
903: for (i = 0; s[i] != '=' && s[i]; i++);
904: if (s[i] == '=') {
905: s[i] = 0;
906: child_set_env(&env, &envsize, s, s + i + 1);
907: }
908: custom_environment = ce->next;
909: xfree(ce->s);
910: xfree(ce);
911: }
912:
913: snprintf(buf, sizeof buf, "%.50s %d %d",
914: get_remote_ipaddr(), get_remote_port(), get_local_port());
915: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
916:
917: if (ttyname)
918: child_set_env(&env, &envsize, "SSH_TTY", ttyname);
919: if (term)
920: child_set_env(&env, &envsize, "TERM", term);
921: if (display)
922: child_set_env(&env, &envsize, "DISPLAY", display);
1.34 markus 923: if (original_command)
924: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
925: original_command);
1.1 markus 926:
927: #ifdef KRB4
928: {
929: extern char *ticket;
930:
931: if (ticket)
932: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
933: }
934: #endif /* KRB4 */
935:
936: if (xauthfile)
937: child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
938: if (auth_get_socket_name() != NULL)
939: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
940: auth_get_socket_name());
941:
942: /* read $HOME/.ssh/environment. */
943: if (!options.use_login) {
1.14 deraadt 944: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
945: pw->pw_dir);
1.1 markus 946: read_environment_file(&env, &envsize, buf);
947: }
948: if (debug_flag) {
949: /* dump the environment */
950: fprintf(stderr, "Environment:\n");
951: for (i = 0; env[i]; i++)
952: fprintf(stderr, " %.200s\n", env[i]);
953: }
1.26 millert 954: /* we have to stash the hostname before we close our socket. */
955: if (options.use_login)
956: hostname = get_remote_name_or_ip();
1.1 markus 957: /*
958: * Close the connection descriptors; note that this is the child, and
959: * the server will still have the socket open, and it is important
960: * that we do not shutdown it. Note that the descriptors cannot be
961: * closed before building the environment, as we call
962: * get_remote_ipaddr there.
963: */
964: if (packet_get_connection_in() == packet_get_connection_out())
965: close(packet_get_connection_in());
966: else {
967: close(packet_get_connection_in());
968: close(packet_get_connection_out());
969: }
970: /*
971: * Close all descriptors related to channels. They will still remain
972: * open in the parent.
973: */
974: /* XXX better use close-on-exec? -markus */
975: channel_close_all();
976:
977: /*
978: * Close any extra file descriptors. Note that there may still be
979: * descriptors left by system functions. They will be closed later.
980: */
981: endpwent();
982:
983: /*
984: * Close any extra open file descriptors so that we don\'t have them
985: * hanging around in clients. Note that we want to do this after
986: * initgroups, because at least on Solaris 2.3 it leaves file
987: * descriptors open.
988: */
989: for (i = 3; i < 64; i++)
990: close(i);
991:
992: /* Change current directory to the user\'s home directory. */
1.28 millert 993: if (chdir(pw->pw_dir) < 0) {
1.1 markus 994: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
995: pw->pw_dir, strerror(errno));
1.28 millert 996: #ifdef HAVE_LOGIN_CAP
997: if (login_getcapbool(lc, "requirehome", 0))
998: exit(1);
999: #endif
1000: }
1.1 markus 1001:
1002: /*
1003: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1004: * xauth are run in the proper environment.
1005: */
1006: environ = env;
1007:
1008: /*
1009: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1010: * in this order).
1011: */
1012: if (!options.use_login) {
1013: if (stat(SSH_USER_RC, &st) >= 0) {
1014: if (debug_flag)
1015: fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC);
1016:
1017: f = popen("/bin/sh " SSH_USER_RC, "w");
1018: if (f) {
1019: if (auth_proto != NULL && auth_data != NULL)
1020: fprintf(f, "%s %s\n", auth_proto, auth_data);
1021: pclose(f);
1022: } else
1023: fprintf(stderr, "Could not run %s\n", SSH_USER_RC);
1024: } else if (stat(SSH_SYSTEM_RC, &st) >= 0) {
1025: if (debug_flag)
1026: fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC);
1027:
1028: f = popen("/bin/sh " SSH_SYSTEM_RC, "w");
1029: if (f) {
1030: if (auth_proto != NULL && auth_data != NULL)
1031: fprintf(f, "%s %s\n", auth_proto, auth_data);
1032: pclose(f);
1033: } else
1034: fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC);
1.16 markus 1035: } else if (options.xauth_location != NULL) {
1.1 markus 1036: /* Add authority data to .Xauthority if appropriate. */
1037: if (auth_proto != NULL && auth_data != NULL) {
1.13 markus 1038: char *screen = strchr(display, ':');
1039: if (debug_flag) {
1.14 deraadt 1040: fprintf(stderr,
1041: "Running %.100s add %.100s %.100s %.100s\n",
1.16 markus 1042: options.xauth_location, display,
1043: auth_proto, auth_data);
1.13 markus 1044: if (screen != NULL)
1.14 deraadt 1045: fprintf(stderr,
1046: "Adding %.*s/unix%s %s %s\n",
1.30 deraadt 1047: (int)(screen-display), display,
1.14 deraadt 1048: screen, auth_proto, auth_data);
1.13 markus 1049: }
1.16 markus 1050: snprintf(cmd, sizeof cmd, "%s -q -",
1051: options.xauth_location);
1052: f = popen(cmd, "w");
1.1 markus 1053: if (f) {
1.14 deraadt 1054: fprintf(f, "add %s %s %s\n", display,
1055: auth_proto, auth_data);
1.13 markus 1056: if (screen != NULL)
1057: fprintf(f, "add %.*s/unix%s %s %s\n",
1.30 deraadt 1058: (int)(screen-display), display,
1.14 deraadt 1059: screen, auth_proto, auth_data);
1.1 markus 1060: pclose(f);
1.16 markus 1061: } else {
1062: fprintf(stderr, "Could not run %s\n",
1063: cmd);
1064: }
1.1 markus 1065: }
1066: }
1067: /* Get the last component of the shell name. */
1068: cp = strrchr(shell, '/');
1069: if (cp)
1070: cp++;
1071: else
1072: cp = shell;
1073: }
1074: /*
1075: * If we have no command, execute the shell. In this case, the shell
1076: * name to be passed in argv[0] is preceded by '-' to indicate that
1077: * this is a login shell.
1078: */
1079: if (!command) {
1080: if (!options.use_login) {
1081: char buf[256];
1082:
1083: /*
1084: * Check for mail if we have a tty and it was enabled
1085: * in server options.
1086: */
1087: if (ttyname && options.check_mail) {
1088: char *mailbox;
1089: struct stat mailstat;
1090: mailbox = getenv("MAIL");
1091: if (mailbox != NULL) {
1.14 deraadt 1092: if (stat(mailbox, &mailstat) != 0 ||
1093: mailstat.st_size == 0)
1.1 markus 1094: printf("No mail.\n");
1095: else if (mailstat.st_mtime < mailstat.st_atime)
1096: printf("You have mail.\n");
1097: else
1098: printf("You have new mail.\n");
1099: }
1100: }
1101: /* Start the shell. Set initial character to '-'. */
1102: buf[0] = '-';
1103: strncpy(buf + 1, cp, sizeof(buf) - 1);
1104: buf[sizeof(buf) - 1] = 0;
1105:
1106: /* Execute the shell. */
1107: argv[0] = buf;
1108: argv[1] = NULL;
1109: execve(shell, argv, env);
1110:
1111: /* Executing the shell failed. */
1112: perror(shell);
1113: exit(1);
1114:
1115: } else {
1116: /* Launch login(1). */
1117:
1.26 millert 1118: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1119: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1120:
1121: /* Login couldn't be executed, die. */
1122:
1123: perror("login");
1124: exit(1);
1125: }
1126: }
1127: /*
1128: * Execute the command using the user's shell. This uses the -c
1129: * option to execute the command.
1130: */
1131: argv[0] = (char *) cp;
1132: argv[1] = "-c";
1133: argv[2] = (char *) command;
1134: argv[3] = NULL;
1135: execve(shell, argv, env);
1136: perror(shell);
1137: exit(1);
1138: }
1139:
1140: Session *
1141: session_new(void)
1142: {
1143: int i;
1144: static int did_init = 0;
1145: if (!did_init) {
1146: debug("session_new: init");
1147: for(i = 0; i < MAX_SESSIONS; i++) {
1148: sessions[i].used = 0;
1149: sessions[i].self = i;
1150: }
1151: did_init = 1;
1152: }
1153: for(i = 0; i < MAX_SESSIONS; i++) {
1154: Session *s = &sessions[i];
1155: if (! s->used) {
1156: s->pid = 0;
1.7 markus 1157: s->extended = 0;
1.1 markus 1158: s->chanid = -1;
1159: s->ptyfd = -1;
1160: s->ttyfd = -1;
1161: s->term = NULL;
1162: s->pw = NULL;
1163: s->display = NULL;
1164: s->screen = 0;
1165: s->auth_data = NULL;
1166: s->auth_proto = NULL;
1167: s->used = 1;
1.7 markus 1168: s->pw = NULL;
1.1 markus 1169: debug("session_new: session %d", i);
1170: return s;
1171: }
1172: }
1173: return NULL;
1174: }
1175:
1176: void
1177: session_dump(void)
1178: {
1179: int i;
1180: for(i = 0; i < MAX_SESSIONS; i++) {
1181: Session *s = &sessions[i];
1182: debug("dump: used %d session %d %p channel %d pid %d",
1183: s->used,
1184: s->self,
1185: s,
1186: s->chanid,
1187: s->pid);
1188: }
1189: }
1190:
1.2 markus 1191: int
1192: session_open(int chanid)
1193: {
1194: Session *s = session_new();
1195: debug("session_open: channel %d", chanid);
1196: if (s == NULL) {
1197: error("no more sessions");
1198: return 0;
1199: }
1.7 markus 1200: s->pw = auth_get_user();
1201: if (s->pw == NULL)
1202: fatal("no user for session %i", s->self);
1.2 markus 1203: debug("session_open: session %d: link with channel %d", s->self, chanid);
1204: s->chanid = chanid;
1205: return 1;
1206: }
1207:
1208: Session *
1209: session_by_channel(int id)
1210: {
1211: int i;
1212: for(i = 0; i < MAX_SESSIONS; i++) {
1213: Session *s = &sessions[i];
1214: if (s->used && s->chanid == id) {
1215: debug("session_by_channel: session %d channel %d", i, id);
1216: return s;
1217: }
1218: }
1219: debug("session_by_channel: unknown channel %d", id);
1220: session_dump();
1221: return NULL;
1222: }
1223:
1224: Session *
1225: session_by_pid(pid_t pid)
1226: {
1227: int i;
1228: debug("session_by_pid: pid %d", pid);
1229: for(i = 0; i < MAX_SESSIONS; i++) {
1230: Session *s = &sessions[i];
1231: if (s->used && s->pid == pid)
1232: return s;
1233: }
1234: error("session_by_pid: unknown pid %d", pid);
1235: session_dump();
1236: return NULL;
1237: }
1238:
1239: int
1240: session_window_change_req(Session *s)
1241: {
1242: s->col = packet_get_int();
1243: s->row = packet_get_int();
1244: s->xpixel = packet_get_int();
1245: s->ypixel = packet_get_int();
1.3 markus 1246: packet_done();
1.2 markus 1247: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1248: return 1;
1249: }
1250:
1251: int
1252: session_pty_req(Session *s)
1253: {
1254: unsigned int len;
1.3 markus 1255: char *term_modes; /* encoded terminal modes */
1.2 markus 1256:
1.19 markus 1257: if (no_pty_flag)
1258: return 0;
1.2 markus 1259: if (s->ttyfd != -1)
1.3 markus 1260: return 0;
1.2 markus 1261: s->term = packet_get_string(&len);
1262: s->col = packet_get_int();
1263: s->row = packet_get_int();
1264: s->xpixel = packet_get_int();
1265: s->ypixel = packet_get_int();
1.3 markus 1266: term_modes = packet_get_string(&len);
1267: packet_done();
1.2 markus 1268:
1269: if (strcmp(s->term, "") == 0) {
1270: xfree(s->term);
1271: s->term = NULL;
1272: }
1273: /* Allocate a pty and open it. */
1274: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1275: xfree(s->term);
1276: s->term = NULL;
1277: s->ptyfd = -1;
1278: s->ttyfd = -1;
1279: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1280: xfree(term_modes);
1281: return 0;
1.2 markus 1282: }
1283: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1284: /*
1285: * Add a cleanup function to clear the utmp entry and record logout
1286: * time in case we call fatal() (e.g., the connection gets closed).
1287: */
1288: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1289: pty_setowner(s->pw, s->tty);
1290: /* Get window size from the packet. */
1291: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1292:
1.9 markus 1293: session_proctitle(s);
1294:
1.3 markus 1295: /* XXX parse and set terminal modes */
1296: xfree(term_modes);
1.2 markus 1297: return 1;
1298: }
1299:
1.7 markus 1300: int
1301: session_subsystem_req(Session *s)
1302: {
1303: unsigned int len;
1304: int success = 0;
1305: char *subsys = packet_get_string(&len);
1.18 jakob 1306: int i;
1.7 markus 1307:
1308: packet_done();
1309: log("subsystem request for %s", subsys);
1.18 jakob 1310:
1311: for (i = 0; i < options.num_subsystems; i++) {
1312: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1313: debug("subsystem: exec() %s", options.subsystem_command[i]);
1314: do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1315: success = 1;
1316: }
1317: }
1318:
1319: if (!success)
1320: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1321:
1322: xfree(subsys);
1323: return success;
1324: }
1325:
1326: int
1327: session_x11_req(Session *s)
1328: {
1.33 markus 1329: int fd;
1.22 deraadt 1330: if (no_x11_forwarding_flag) {
1.19 markus 1331: debug("X11 forwarding disabled in user configuration file.");
1332: return 0;
1333: }
1.7 markus 1334: if (!options.x11_forwarding) {
1335: debug("X11 forwarding disabled in server configuration file.");
1336: return 0;
1337: }
1338: if (xauthfile != NULL) {
1339: debug("X11 fwd already started.");
1340: return 0;
1341: }
1342:
1343: debug("Received request for X11 forwarding with auth spoofing.");
1344: if (s->display != NULL)
1345: packet_disconnect("Protocol error: X11 display already set.");
1346:
1347: s->single_connection = packet_get_char();
1348: s->auth_proto = packet_get_string(NULL);
1349: s->auth_data = packet_get_string(NULL);
1350: s->screen = packet_get_int();
1351: packet_done();
1352:
1353: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1354: if (s->display == NULL) {
1355: xfree(s->auth_proto);
1356: xfree(s->auth_data);
1357: return 0;
1358: }
1359: xauthfile = xmalloc(MAXPATHLEN);
1360: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1361: temporarily_use_uid(s->pw->pw_uid);
1362: if (mkdtemp(xauthfile) == NULL) {
1363: restore_uid();
1364: error("private X11 dir: mkdtemp %s failed: %s",
1365: xauthfile, strerror(errno));
1366: xfree(xauthfile);
1367: xauthfile = NULL;
1368: xfree(s->auth_proto);
1369: xfree(s->auth_data);
1370: /* XXXX remove listening channels */
1371: return 0;
1372: }
1373: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 1374: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1375: if (fd >= 0)
1376: close(fd);
1.7 markus 1377: restore_uid();
1378: fatal_add_cleanup(xauthfile_cleanup_proc, s);
1379: return 1;
1380: }
1381:
1.19 markus 1382: int
1383: session_shell_req(Session *s)
1384: {
1385: /* if forced_command == NULL, the shell is execed */
1386: char *shell = forced_command;
1387: packet_done();
1388: s->extended = 1;
1389: if (s->ttyfd == -1)
1390: do_exec_no_pty(s, shell, s->pw);
1391: else
1392: do_exec_pty(s, shell, s->pw);
1393: return 1;
1394: }
1395:
1396: int
1397: session_exec_req(Session *s)
1398: {
1.20 markus 1399: unsigned int len;
1.19 markus 1400: char *command = packet_get_string(&len);
1401: packet_done();
1402: if (forced_command) {
1.34 markus 1403: original_command = command;
1.19 markus 1404: command = forced_command;
1405: debug("Forced command '%.500s'", forced_command);
1406: }
1407: s->extended = 1;
1408: if (s->ttyfd == -1)
1409: do_exec_no_pty(s, command, s->pw);
1410: else
1411: do_exec_pty(s, command, s->pw);
1412: if (forced_command == NULL)
1413: xfree(command);
1414: return 1;
1415: }
1416:
1.2 markus 1417: void
1418: session_input_channel_req(int id, void *arg)
1419: {
1420: unsigned int len;
1421: int reply;
1422: int success = 0;
1423: char *rtype;
1424: Session *s;
1425: Channel *c;
1426:
1427: rtype = packet_get_string(&len);
1428: reply = packet_get_char();
1429:
1430: s = session_by_channel(id);
1431: if (s == NULL)
1432: fatal("session_input_channel_req: channel %d: no session", id);
1433: c = channel_lookup(id);
1434: if (c == NULL)
1435: fatal("session_input_channel_req: channel %d: bad channel", id);
1436:
1437: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1438: s->self, id, rtype, reply);
1439:
1440: /*
1441: * a session is in LARVAL state until a shell
1442: * or programm is executed
1443: */
1444: if (c->type == SSH_CHANNEL_LARVAL) {
1445: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1446: success = session_shell_req(s);
1.2 markus 1447: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1448: success = session_exec_req(s);
1.2 markus 1449: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1450: success = session_pty_req(s);
1.7 markus 1451: } else if (strcmp(rtype, "x11-req") == 0) {
1452: success = session_x11_req(s);
1453: } else if (strcmp(rtype, "subsystem") == 0) {
1454: success = session_subsystem_req(s);
1.2 markus 1455: }
1456: }
1457: if (strcmp(rtype, "window-change") == 0) {
1458: success = session_window_change_req(s);
1459: }
1460:
1461: if (reply) {
1462: packet_start(success ?
1463: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1464: packet_put_int(c->remote_id);
1465: packet_send();
1466: }
1467: xfree(rtype);
1468: }
1469:
1470: void
1471: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1472: {
1473: if (!compat20)
1474: fatal("session_set_fds: called for proto != 2.0");
1475: /*
1476: * now that have a child and a pipe to the child,
1477: * we can activate our channel and register the fd's
1478: */
1479: if (s->chanid == -1)
1480: fatal("no channel for session %d", s->self);
1481: channel_set_fds(s->chanid,
1482: fdout, fdin, fderr,
1483: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ);
1484: }
1485:
1.1 markus 1486: void
1487: session_pty_cleanup(Session *s)
1488: {
1489: if (s == NULL || s->ttyfd == -1)
1490: return;
1491:
1492: debug("session_pty_cleanup: session %i release %s", s->self, s->tty);
1493:
1494: /* Cancel the cleanup function. */
1495: fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1496:
1497: /* Record that the user has logged out. */
1498: record_logout(s->pid, s->tty);
1499:
1500: /* Release the pseudo-tty. */
1501: pty_release(s->tty);
1502:
1503: /*
1504: * Close the server side of the socket pairs. We must do this after
1505: * the pty cleanup, so that another process doesn't get this pty
1506: * while we're still cleaning up.
1507: */
1508: if (close(s->ptymaster) < 0)
1509: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1510: }
1511:
1512: void
1513: session_exit_message(Session *s, int status)
1514: {
1515: Channel *c;
1516: if (s == NULL)
1517: fatal("session_close: no session");
1518: c = channel_lookup(s->chanid);
1519: if (c == NULL)
1520: fatal("session_close: session %d: no channel %d",
1521: s->self, s->chanid);
1522: debug("session_exit_message: session %d channel %d pid %d",
1523: s->self, s->chanid, s->pid);
1524:
1525: if (WIFEXITED(status)) {
1526: channel_request_start(s->chanid,
1527: "exit-status", 0);
1528: packet_put_int(WEXITSTATUS(status));
1529: packet_send();
1530: } else if (WIFSIGNALED(status)) {
1531: channel_request_start(s->chanid,
1532: "exit-signal", 0);
1533: packet_put_int(WTERMSIG(status));
1534: packet_put_char(WCOREDUMP(status));
1535: packet_put_cstring("");
1536: packet_put_cstring("");
1537: packet_send();
1538: } else {
1539: /* Some weird exit cause. Just exit. */
1540: packet_disconnect("wait returned status %04x.", status);
1541: }
1542:
1543: /* disconnect channel */
1544: debug("session_exit_message: release channel %d", s->chanid);
1545: channel_cancel_cleanup(s->chanid);
1.5 markus 1546: /*
1547: * emulate a write failure with 'chan_write_failed', nobody will be
1548: * interested in data we write.
1549: * Note that we must not call 'chan_read_failed', since there could
1550: * be some more data waiting in the pipe.
1551: */
1.8 markus 1552: if (c->ostate != CHAN_OUTPUT_CLOSED)
1553: chan_write_failed(c);
1.2 markus 1554: s->chanid = -1;
1555: }
1556:
1557: void
1558: session_free(Session *s)
1559: {
1560: debug("session_free: session %d pid %d", s->self, s->pid);
1561: if (s->term)
1562: xfree(s->term);
1563: if (s->display)
1564: xfree(s->display);
1565: if (s->auth_data)
1566: xfree(s->auth_data);
1567: if (s->auth_proto)
1568: xfree(s->auth_proto);
1569: s->used = 0;
1570: }
1571:
1572: void
1573: session_close(Session *s)
1574: {
1575: session_pty_cleanup(s);
1576: session_free(s);
1.9 markus 1577: session_proctitle(s);
1.2 markus 1578: }
1579:
1580: void
1581: session_close_by_pid(pid_t pid, int status)
1582: {
1583: Session *s = session_by_pid(pid);
1584: if (s == NULL) {
1585: debug("session_close_by_pid: no session for pid %d", s->pid);
1586: return;
1587: }
1588: if (s->chanid != -1)
1589: session_exit_message(s, status);
1590: session_close(s);
1591: }
1592:
1593: /*
1594: * this is called when a channel dies before
1595: * the session 'child' itself dies
1596: */
1597: void
1598: session_close_by_channel(int id, void *arg)
1599: {
1600: Session *s = session_by_channel(id);
1601: if (s == NULL) {
1602: debug("session_close_by_channel: no session for channel %d", id);
1603: return;
1604: }
1605: /* disconnect channel */
1606: channel_cancel_cleanup(s->chanid);
1607: s->chanid = -1;
1608:
1609: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1610: if (s->pid == 0) {
1611: /* close session immediately */
1612: session_close(s);
1613: } else {
1614: /* notify child, delay session cleanup */
1615: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1616: error("session_close_by_channel: kill %d: %s",
1617: s->pid, strerror(errno));
1618: }
1.9 markus 1619: }
1620:
1621: char *
1622: session_tty_list(void)
1623: {
1624: static char buf[1024];
1625: int i;
1626: buf[0] = '\0';
1627: for(i = 0; i < MAX_SESSIONS; i++) {
1628: Session *s = &sessions[i];
1629: if (s->used && s->ttyfd != -1) {
1630: if (buf[0] != '\0')
1631: strlcat(buf, ",", sizeof buf);
1632: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1633: }
1634: }
1635: if (buf[0] == '\0')
1636: strlcpy(buf, "notty", sizeof buf);
1637: return buf;
1638: }
1639:
1640: void
1641: session_proctitle(Session *s)
1642: {
1643: if (s->pw == NULL)
1644: error("no user for session %d", s->self);
1645: else
1646: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1647: }
1648:
1649: void
1650: do_authenticated2(void)
1651: {
1.28 millert 1652: struct passwd *pw;
1653:
1.2 markus 1654: /*
1655: * Cancel the alarm we set to limit the time taken for
1656: * authentication.
1657: */
1658: alarm(0);
1.23 deraadt 1659: if (startup_pipe != -1) {
1660: close(startup_pipe);
1661: startup_pipe = -1;
1662: }
1.28 millert 1663: #ifdef HAVE_LOGIN_CAP
1664: pw = auth_get_user();
1665: if ((lc = login_getclass(pw->pw_class)) == NULL) {
1666: error("unable to get login class");
1667: return;
1668: }
1669: #endif
1.2 markus 1670: server_loop2();
1.7 markus 1671: if (xauthfile)
1672: xauthfile_cleanup_proc(NULL);
1.1 markus 1673: }
![[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