Annotation of src/usr.bin/ssh/session.c, Revision 1.12.2.4
1.1 markus 1: /*
2: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
3: * All rights reserved
1.12.2.3 jason 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.
1.12.2.3 jason 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"
1.12.2.4! jason 36: RCSID("$OpenBSD: session.c,v 1.56 2001/02/16 14:03:43 markus Exp $");
1.1 markus 37:
38: #include "ssh.h"
1.12.2.4! jason 39: #include "ssh1.h"
! 40: #include "ssh2.h"
! 41: #include "xmalloc.h"
1.1 markus 42: #include "pty.h"
43: #include "packet.h"
44: #include "buffer.h"
45: #include "mpaux.h"
46: #include "uidswap.h"
47: #include "compat.h"
48: #include "channels.h"
49: #include "nchan.h"
1.2 markus 50: #include "bufaux.h"
51: #include "auth.h"
1.12.2.2 jason 52: #include "auth-options.h"
1.12.2.4! jason 53: #include "pathnames.h"
! 54: #include "log.h"
! 55: #include "servconf.h"
! 56: #include "login.h"
! 57: #include "serverloop.h"
! 58: #include "canohost.h"
! 59: #include "session.h"
1.12.2.2 jason 60:
61: #ifdef HAVE_LOGIN_CAP
62: #include <login_cap.h>
63: #endif
1.2 markus 64:
1.1 markus 65: /* types */
66:
67: #define TTYSZ 64
68: typedef struct Session Session;
69: struct Session {
70: int used;
71: int self;
1.7 markus 72: int extended;
1.1 markus 73: struct passwd *pw;
74: pid_t pid;
75: /* tty */
76: char *term;
77: int ptyfd, ttyfd, ptymaster;
78: int row, col, xpixel, ypixel;
79: char tty[TTYSZ];
80: /* X11 */
81: char *display;
82: int screen;
83: char *auth_proto;
84: char *auth_data;
1.7 markus 85: int single_connection;
1.1 markus 86: /* proto 2 */
87: int chanid;
88: };
89:
90: /* func */
91:
92: Session *session_new(void);
93: void session_set_fds(Session *s, int fdin, int fdout, int fderr);
94: void session_pty_cleanup(Session *s);
1.9 markus 95: void session_proctitle(Session *s);
1.1 markus 96: void do_exec_pty(Session *s, const char *command, struct passwd * pw);
97: void do_exec_no_pty(Session *s, const char *command, struct passwd * pw);
1.12.2.3 jason 98: void do_login(Session *s, const char *command);
1.1 markus 99:
100: void
101: do_child(const char *command, struct passwd * pw, const char *term,
102: const char *display, const char *auth_proto,
103: const char *auth_data, const char *ttyname);
104:
105: /* import */
106: extern ServerOptions options;
107: extern char *__progname;
108: extern int log_stderr;
109: extern int debug_flag;
1.12.2.4! jason 110: extern u_int utmp_len;
1.12.2.2 jason 111:
112: extern int startup_pipe;
1.1 markus 113:
114: /* Local Xauthority file. */
115: static char *xauthfile;
116:
1.12.2.3 jason 117: /* original command from peer. */
1.12.2.4! jason 118: char *original_command = NULL;
1.12.2.3 jason 119:
1.1 markus 120: /* data */
121: #define MAX_SESSIONS 10
122: Session sessions[MAX_SESSIONS];
123:
1.12.2.2 jason 124: #ifdef HAVE_LOGIN_CAP
125: static login_cap_t *lc;
126: #endif
1.1 markus 127:
128: /*
129: * Remove local Xauthority file.
130: */
131: void
132: xauthfile_cleanup_proc(void *ignore)
133: {
134: debug("xauthfile_cleanup_proc called");
135:
136: if (xauthfile != NULL) {
137: char *p;
138: unlink(xauthfile);
139: p = strrchr(xauthfile, '/');
140: if (p != NULL) {
141: *p = '\0';
142: rmdir(xauthfile);
143: }
144: xfree(xauthfile);
145: xauthfile = NULL;
146: }
147: }
148:
149: /*
150: * Function to perform cleanup if we get aborted abnormally (e.g., due to a
151: * dropped connection).
152: */
1.4 markus 153: void
1.1 markus 154: pty_cleanup_proc(void *session)
155: {
156: Session *s=session;
157: if (s == NULL)
158: fatal("pty_cleanup_proc: no session");
159: debug("pty_cleanup_proc: %s", s->tty);
160:
161: if (s->pid != 0) {
162: /* Record that the user has logged out. */
163: record_logout(s->pid, s->tty);
164: }
165:
166: /* Release the pseudo-tty. */
167: pty_release(s->tty);
168: }
169:
170: /*
171: * Prepares for an interactive session. This is called after the user has
172: * been successfully authenticated. During this message exchange, pseudo
173: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
174: * are requested, etc.
175: */
1.4 markus 176: void
1.1 markus 177: do_authenticated(struct passwd * pw)
178: {
179: Session *s;
1.12.2.3 jason 180: int type, fd;
1.1 markus 181: int compression_level = 0, enable_compression_after_reply = 0;
182: int have_pty = 0;
183: char *command;
184: int n_bytes;
185: int plen;
1.12.2.4! jason 186: u_int proto_len, data_len, dlen;
1.1 markus 187:
188: /*
189: * Cancel the alarm we set to limit the time taken for
190: * authentication.
191: */
192: alarm(0);
1.12.2.2 jason 193: if (startup_pipe != -1) {
194: close(startup_pipe);
195: startup_pipe = -1;
196: }
1.1 markus 197:
198: /*
199: * Inform the channel mechanism that we are the server side and that
200: * the client may request to connect to any port at all. (The user
201: * could do it anyway, and we wouldn\'t know what is permitted except
202: * by the client telling us, so we can equally well trust the client
203: * not to request anything bogus.)
204: */
1.12.2.3 jason 205: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
1.1 markus 206: channel_permit_all_opens();
207:
208: s = session_new();
1.7 markus 209: s->pw = pw;
1.1 markus 210:
1.12.2.2 jason 211: #ifdef HAVE_LOGIN_CAP
212: if ((lc = login_getclass(pw->pw_class)) == NULL) {
213: error("unable to get login class");
214: return;
215: }
216: #endif
217:
1.1 markus 218: /*
219: * We stay in this loop until the client requests to execute a shell
220: * or a command.
221: */
222: for (;;) {
223: int success = 0;
224:
225: /* Get a packet from the client. */
226: type = packet_read(&plen);
227:
228: /* Process the packet. */
229: switch (type) {
230: case SSH_CMSG_REQUEST_COMPRESSION:
231: packet_integrity_check(plen, 4, type);
232: compression_level = packet_get_int();
233: if (compression_level < 1 || compression_level > 9) {
234: packet_send_debug("Received illegal compression level %d.",
235: compression_level);
236: break;
237: }
238: /* Enable compression after we have responded with SUCCESS. */
239: enable_compression_after_reply = 1;
240: success = 1;
241: break;
242:
243: case SSH_CMSG_REQUEST_PTY:
244: if (no_pty_flag) {
245: debug("Allocating a pty not permitted for this authentication.");
246: break;
247: }
248: if (have_pty)
249: packet_disconnect("Protocol error: you already have a pty.");
250:
251: debug("Allocating pty.");
252:
253: /* Allocate a pty and open it. */
254: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
255: sizeof(s->tty))) {
256: error("Failed to allocate pty.");
257: break;
258: }
259: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
260: pty_setowner(pw, s->tty);
261:
262: /* Get TERM from the packet. Note that the value may be of arbitrary length. */
263: s->term = packet_get_string(&dlen);
264: packet_integrity_check(dlen, strlen(s->term), type);
265: /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
266: /* Remaining bytes */
267: n_bytes = plen - (4 + dlen + 4 * 4);
268:
269: if (strcmp(s->term, "") == 0) {
270: xfree(s->term);
271: s->term = NULL;
272: }
273: /* Get window size from the packet. */
274: s->row = packet_get_int();
275: s->col = packet_get_int();
276: s->xpixel = packet_get_int();
277: s->ypixel = packet_get_int();
278: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
279:
280: /* Get tty modes from the packet. */
281: tty_parse_modes(s->ttyfd, &n_bytes);
282: packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
1.10 markus 283:
284: session_proctitle(s);
1.1 markus 285:
286: /* Indicate that we now have a pty. */
287: success = 1;
288: have_pty = 1;
289: break;
290:
291: case SSH_CMSG_X11_REQUEST_FORWARDING:
292: if (!options.x11_forwarding) {
293: packet_send_debug("X11 forwarding disabled in server configuration file.");
294: break;
295: }
1.12.2.1 jason 296: if (!options.xauth_location) {
297: packet_send_debug("No xauth program; cannot forward with spoofing.");
298: break;
299: }
1.1 markus 300: if (no_x11_forwarding_flag) {
301: packet_send_debug("X11 forwarding not permitted for this authentication.");
302: break;
303: }
304: debug("Received request for X11 forwarding with auth spoofing.");
305: if (s->display != NULL)
306: packet_disconnect("Protocol error: X11 display already set.");
307:
308: s->auth_proto = packet_get_string(&proto_len);
309: s->auth_data = packet_get_string(&data_len);
310:
1.12.2.4! jason 311: if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) {
! 312: debug2("SSH_PROTOFLAG_SCREEN_NUMBER == true");
! 313: packet_integrity_check(plen,
! 314: 4 + proto_len + 4 + data_len + 4, type);
1.1 markus 315: s->screen = packet_get_int();
1.12.2.4! jason 316: } else {
! 317: debug2("SSH_PROTOFLAG_SCREEN_NUMBER == false");
! 318: packet_integrity_check(plen,
! 319: 4 + proto_len + 4 + data_len, type);
1.1 markus 320: s->screen = 0;
1.12.2.4! jason 321: }
1.1 markus 322: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
323:
324: if (s->display == NULL)
325: break;
326:
327: /* Setup to always have a local .Xauthority. */
328: xauthfile = xmalloc(MAXPATHLEN);
329: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
330: temporarily_use_uid(pw->pw_uid);
331: if (mkdtemp(xauthfile) == NULL) {
332: restore_uid();
333: error("private X11 dir: mkdtemp %s failed: %s",
334: xauthfile, strerror(errno));
335: xfree(xauthfile);
336: xauthfile = NULL;
1.7 markus 337: /* XXXX remove listening channels */
1.1 markus 338: break;
339: }
340: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.12.2.3 jason 341: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
342: if (fd >= 0)
343: close(fd);
1.1 markus 344: restore_uid();
345: fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
346: success = 1;
347: break;
348:
349: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
350: if (no_agent_forwarding_flag || compat13) {
351: debug("Authentication agent forwarding not permitted for this authentication.");
352: break;
353: }
354: debug("Received authentication agent forwarding request.");
1.12.2.1 jason 355: success = auth_input_request_forwarding(pw);
1.1 markus 356: break;
357:
358: case SSH_CMSG_PORT_FORWARD_REQUEST:
359: if (no_port_forwarding_flag) {
360: debug("Port forwarding not permitted for this authentication.");
361: break;
362: }
1.12.2.3 jason 363: if (!options.allow_tcp_forwarding) {
364: debug("Port forwarding not permitted.");
365: break;
366: }
1.1 markus 367: debug("Received TCP/IP port forwarding request.");
1.12 markus 368: channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
1.1 markus 369: success = 1;
370: break;
371:
372: case SSH_CMSG_MAX_PACKET_SIZE:
373: if (packet_set_maxsize(packet_get_int()) > 0)
374: success = 1;
375: break;
376:
377: case SSH_CMSG_EXEC_SHELL:
378: case SSH_CMSG_EXEC_CMD:
379: if (type == SSH_CMSG_EXEC_CMD) {
380: command = packet_get_string(&dlen);
381: debug("Exec command '%.500s'", command);
382: packet_integrity_check(plen, 4 + dlen, type);
383: } else {
384: command = NULL;
385: packet_integrity_check(plen, 0, type);
386: }
387: if (forced_command != NULL) {
1.12.2.3 jason 388: original_command = command;
1.1 markus 389: command = forced_command;
390: debug("Forced command '%.500s'", forced_command);
391: }
392: if (have_pty)
393: do_exec_pty(s, command, pw);
394: else
395: do_exec_no_pty(s, command, pw);
396:
397: if (command != NULL)
398: xfree(command);
399: /* Cleanup user's local Xauthority file. */
400: if (xauthfile)
401: xauthfile_cleanup_proc(NULL);
402: return;
403:
404: default:
405: /*
406: * Any unknown messages in this phase are ignored,
407: * and a failure message is returned.
408: */
409: log("Unknown packet type received after authentication: %d", type);
410: }
411: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
412: packet_send();
413: packet_write_wait();
414:
415: /* Enable compression now that we have replied if appropriate. */
416: if (enable_compression_after_reply) {
417: enable_compression_after_reply = 0;
418: packet_start_compression(compression_level);
419: }
420: }
421: }
422:
423: /*
424: * This is called to fork and execute a command when we have no tty. This
425: * will call do_child from the child, and server_loop from the parent after
426: * setting up file descriptors and such.
427: */
1.4 markus 428: void
1.1 markus 429: do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
430: {
431: int pid;
432:
433: #ifdef USE_PIPES
434: int pin[2], pout[2], perr[2];
435: /* Allocate pipes for communicating with the program. */
436: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
437: packet_disconnect("Could not create pipes: %.100s",
438: strerror(errno));
439: #else /* USE_PIPES */
440: int inout[2], err[2];
441: /* Uses socket pairs to communicate with the program. */
442: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
443: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
444: packet_disconnect("Could not create socket pairs: %.100s",
445: strerror(errno));
446: #endif /* USE_PIPES */
447: if (s == NULL)
448: fatal("do_exec_no_pty: no session");
449:
1.9 markus 450: session_proctitle(s);
1.1 markus 451:
452: /* Fork the child. */
453: if ((pid = fork()) == 0) {
454: /* Child. Reinitialize the log since the pid has changed. */
455: log_init(__progname, options.log_level, options.log_facility, log_stderr);
456:
457: /*
458: * Create a new session and process group since the 4.4BSD
459: * setlogin() affects the entire process group.
460: */
461: if (setsid() < 0)
462: error("setsid failed: %.100s", strerror(errno));
463:
464: #ifdef USE_PIPES
465: /*
466: * Redirect stdin. We close the parent side of the socket
467: * pair, and make the child side the standard input.
468: */
469: close(pin[1]);
470: if (dup2(pin[0], 0) < 0)
471: perror("dup2 stdin");
472: close(pin[0]);
473:
474: /* Redirect stdout. */
475: close(pout[0]);
476: if (dup2(pout[1], 1) < 0)
477: perror("dup2 stdout");
478: close(pout[1]);
479:
480: /* Redirect stderr. */
481: close(perr[0]);
482: if (dup2(perr[1], 2) < 0)
483: perror("dup2 stderr");
484: close(perr[1]);
485: #else /* USE_PIPES */
486: /*
487: * Redirect stdin, stdout, and stderr. Stdin and stdout will
488: * use the same socket, as some programs (particularly rdist)
489: * seem to depend on it.
490: */
491: close(inout[1]);
492: close(err[1]);
493: if (dup2(inout[0], 0) < 0) /* stdin */
494: perror("dup2 stdin");
495: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
496: perror("dup2 stdout");
497: if (dup2(err[0], 2) < 0) /* stderr */
498: perror("dup2 stderr");
499: #endif /* USE_PIPES */
500:
501: /* Do processing for the child (exec command etc). */
502: do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL);
503: /* NOTREACHED */
504: }
505: if (pid < 0)
506: packet_disconnect("fork failed: %.100s", strerror(errno));
507: s->pid = pid;
1.12.2.4! jason 508: /* Set interactive/non-interactive mode. */
! 509: packet_set_interactive(s->display != NULL);
1.1 markus 510: #ifdef USE_PIPES
511: /* We are the parent. Close the child sides of the pipes. */
512: close(pin[0]);
513: close(pout[1]);
514: close(perr[1]);
515:
1.2 markus 516: if (compat20) {
1.7 markus 517: session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
1.2 markus 518: } else {
519: /* Enter the interactive session. */
520: server_loop(pid, pin[1], pout[0], perr[0]);
521: /* server_loop has closed pin[1], pout[1], and perr[1]. */
522: }
1.1 markus 523: #else /* USE_PIPES */
524: /* We are the parent. Close the child sides of the socket pairs. */
525: close(inout[0]);
526: close(err[0]);
527:
528: /*
529: * Enter the interactive session. Note: server_loop must be able to
530: * handle the case that fdin and fdout are the same.
531: */
1.2 markus 532: if (compat20) {
1.7 markus 533: session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
1.2 markus 534: } else {
535: server_loop(pid, inout[1], inout[1], err[1]);
536: /* server_loop has closed inout[1] and err[1]. */
537: }
1.1 markus 538: #endif /* USE_PIPES */
539: }
540:
541: /*
542: * This is called to fork and execute a command when we have a tty. This
543: * will call do_child from the child, and server_loop from the parent after
544: * setting up file descriptors, controlling tty, updating wtmp, utmp,
545: * lastlog, and other such operations.
546: */
1.4 markus 547: void
1.1 markus 548: do_exec_pty(Session *s, const char *command, struct passwd * pw)
549: {
550: int fdout, ptyfd, ttyfd, ptymaster;
551: pid_t pid;
552:
553: if (s == NULL)
554: fatal("do_exec_pty: no session");
555: ptyfd = s->ptyfd;
556: ttyfd = s->ttyfd;
557:
558: /* Fork the child. */
559: if ((pid = fork()) == 0) {
1.12.2.2 jason 560: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 561: log_init(__progname, options.log_level, options.log_facility, log_stderr);
562:
563: /* Close the master side of the pseudo tty. */
564: close(ptyfd);
565:
566: /* Make the pseudo tty our controlling tty. */
567: pty_make_controlling_tty(&ttyfd, s->tty);
568:
569: /* Redirect stdin from the pseudo tty. */
570: if (dup2(ttyfd, fileno(stdin)) < 0)
571: error("dup2 stdin failed: %.100s", strerror(errno));
572:
573: /* Redirect stdout to the pseudo tty. */
574: if (dup2(ttyfd, fileno(stdout)) < 0)
575: error("dup2 stdin failed: %.100s", strerror(errno));
576:
577: /* Redirect stderr to the pseudo tty. */
578: if (dup2(ttyfd, fileno(stderr)) < 0)
579: error("dup2 stdin failed: %.100s", strerror(errno));
580:
581: /* Close the extra descriptor for the pseudo tty. */
582: close(ttyfd);
583:
1.12.2.2 jason 584: /* record login, etc. similar to login(1) */
1.12.2.3 jason 585: if (!(options.use_login && command == NULL))
586: do_login(s, command);
1.1 markus 587:
588: /* Do common processing for the child, such as execing the command. */
1.12.2.1 jason 589: do_child(command, pw, s->term, s->display, s->auth_proto,
590: s->auth_data, s->tty);
1.1 markus 591: /* NOTREACHED */
592: }
593: if (pid < 0)
594: packet_disconnect("fork failed: %.100s", strerror(errno));
595: s->pid = pid;
596:
597: /* Parent. Close the slave side of the pseudo tty. */
598: close(ttyfd);
599:
600: /*
601: * Create another descriptor of the pty master side for use as the
602: * standard input. We could use the original descriptor, but this
603: * simplifies code in server_loop. The descriptor is bidirectional.
604: */
605: fdout = dup(ptyfd);
606: if (fdout < 0)
607: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
608:
609: /* we keep a reference to the pty master */
610: ptymaster = dup(ptyfd);
611: if (ptymaster < 0)
612: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
613: s->ptymaster = ptymaster;
614:
615: /* Enter interactive session. */
1.12.2.4! jason 616: packet_set_interactive(1);
1.2 markus 617: if (compat20) {
618: session_set_fds(s, ptyfd, fdout, -1);
619: } else {
620: server_loop(pid, ptyfd, fdout, -1);
621: /* server_loop _has_ closed ptyfd and fdout. */
622: session_pty_cleanup(s);
623: }
1.1 markus 624: }
625:
1.12.2.2 jason 626: const char *
627: get_remote_name_or_ip(void)
628: {
629: static const char *remote = "";
630: if (utmp_len > 0)
1.12.2.4! jason 631: remote = get_canonical_hostname(options.reverse_mapping_check);
1.12.2.2 jason 632: if (utmp_len == 0 || strlen(remote) > utmp_len)
633: remote = get_remote_ipaddr();
634: return remote;
635: }
636:
637: /* administrative, login(1)-like work */
638: void
1.12.2.3 jason 639: do_login(Session *s, const char *command)
1.12.2.2 jason 640: {
641: FILE *f;
642: char *time_string;
643: char buf[256];
1.12.2.3 jason 644: char hostname[MAXHOSTNAMELEN];
1.12.2.2 jason 645: socklen_t fromlen;
646: struct sockaddr_storage from;
647: struct stat st;
648: time_t last_login_time;
649: struct passwd * pw = s->pw;
650: pid_t pid = getpid();
651:
652: /*
653: * Get IP address of client. If the connection is not a socket, let
654: * the address be 0.0.0.0.
655: */
656: memset(&from, 0, sizeof(from));
657: if (packet_connection_is_on_socket()) {
658: fromlen = sizeof(from);
659: if (getpeername(packet_get_connection_in(),
660: (struct sockaddr *) & from, &fromlen) < 0) {
661: debug("getpeername: %.100s", strerror(errno));
662: fatal_cleanup();
663: }
664: }
665:
1.12.2.3 jason 666: /* Get the time and hostname when the user last logged in. */
667: hostname[0] = '\0';
668: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
669: hostname, sizeof(hostname));
670:
1.12.2.2 jason 671: /* Record that there was a login on that tty from the remote host. */
672: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
673: get_remote_name_or_ip(), (struct sockaddr *)&from);
674:
1.12.2.3 jason 675: /* Done if .hushlogin exists or a command given. */
676: if (command != NULL)
677: return;
1.12.2.2 jason 678: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
679: #ifdef HAVE_LOGIN_CAP
680: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
681: #else
682: if (stat(buf, &st) >= 0)
683: #endif
684: return;
685: if (last_login_time != 0) {
686: time_string = ctime(&last_login_time);
687: if (strchr(time_string, '\n'))
688: *strchr(time_string, '\n') = 0;
1.12.2.3 jason 689: if (strcmp(hostname, "") == 0)
1.12.2.2 jason 690: printf("Last login: %s\r\n", time_string);
691: else
1.12.2.3 jason 692: printf("Last login: %s from %s\r\n", time_string, hostname);
1.12.2.2 jason 693: }
694: if (options.print_motd) {
695: #ifdef HAVE_LOGIN_CAP
696: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
697: "/etc/motd"), "r");
698: #else
699: f = fopen("/etc/motd", "r");
700: #endif
701: if (f) {
702: while (fgets(buf, sizeof(buf), f))
703: fputs(buf, stdout);
704: fclose(f);
705: }
706: }
707: }
708:
1.1 markus 709: /*
710: * Sets the value of the given variable in the environment. If the variable
711: * already exists, its value is overriden.
712: */
1.4 markus 713: void
1.12.2.4! jason 714: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 715: const char *value)
716: {
1.12.2.4! jason 717: u_int i, namelen;
1.1 markus 718: char **env;
719:
720: /*
721: * Find the slot where the value should be stored. If the variable
722: * already exists, we reuse the slot; otherwise we append a new slot
723: * at the end of the array, expanding if necessary.
724: */
725: env = *envp;
726: namelen = strlen(name);
727: for (i = 0; env[i]; i++)
728: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
729: break;
730: if (env[i]) {
731: /* Reuse the slot. */
732: xfree(env[i]);
733: } else {
734: /* New variable. Expand if necessary. */
735: if (i >= (*envsizep) - 1) {
736: (*envsizep) += 50;
737: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
738: }
739: /* Need to set the NULL pointer at end of array beyond the new slot. */
740: env[i + 1] = NULL;
741: }
742:
743: /* Allocate space and format the variable in the appropriate slot. */
744: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
745: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
746: }
747:
748: /*
749: * Reads environment variables from the given file and adds/overrides them
750: * into the environment. If the file does not exist, this does nothing.
751: * Otherwise, it must consist of empty lines, comments (line starts with '#')
752: * and assignments of the form name=value. No other forms are allowed.
753: */
1.4 markus 754: void
1.12.2.4! jason 755: read_environment_file(char ***env, u_int *envsize,
1.1 markus 756: const char *filename)
757: {
758: FILE *f;
759: char buf[4096];
760: char *cp, *value;
761:
762: f = fopen(filename, "r");
763: if (!f)
764: return;
765:
766: while (fgets(buf, sizeof(buf), f)) {
767: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
768: ;
769: if (!*cp || *cp == '#' || *cp == '\n')
770: continue;
771: if (strchr(cp, '\n'))
772: *strchr(cp, '\n') = '\0';
773: value = strchr(cp, '=');
774: if (value == NULL) {
775: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
776: continue;
777: }
1.12.2.1 jason 778: /*
779: * Replace the equals sign by nul, and advance value to
780: * the value string.
781: */
1.1 markus 782: *value = '\0';
783: value++;
784: child_set_env(env, envsize, cp, value);
785: }
786: fclose(f);
787: }
788:
789: /*
790: * Performs common processing for the child, such as setting up the
791: * environment, closing extra file descriptors, setting the user and group
792: * ids, and executing the command or shell.
793: */
1.4 markus 794: void
1.1 markus 795: do_child(const char *command, struct passwd * pw, const char *term,
796: const char *display, const char *auth_proto,
797: const char *auth_data, const char *ttyname)
798: {
1.12.2.3 jason 799: const char *shell, *hostname = NULL, *cp = NULL;
1.1 markus 800: char buf[256];
1.12.2.1 jason 801: char cmd[1024];
1.12.2.2 jason 802: FILE *f = NULL;
1.12.2.4! jason 803: u_int envsize, i;
1.1 markus 804: char **env;
805: extern char **environ;
806: struct stat st;
807: char *argv[10];
808:
1.12.2.1 jason 809: /* login(1) is only called if we execute the login shell */
810: if (options.use_login && command != NULL)
811: options.use_login = 0;
812:
1.12.2.2 jason 813: if (!options.use_login) {
814: #ifdef HAVE_LOGIN_CAP
815: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
816: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
817: _PATH_NOLOGIN), "r");
818: #else
819: if (pw->pw_uid)
820: f = fopen(_PATH_NOLOGIN, "r");
821: #endif
822: if (f) {
823: /* /etc/nologin exists. Print its contents and exit. */
824: while (fgets(buf, sizeof(buf), f))
825: fputs(buf, stderr);
826: fclose(f);
1.1 markus 827: exit(254);
1.12.2.2 jason 828: }
1.1 markus 829: }
1.12.2.2 jason 830: /* Set login name, uid, gid, and groups. */
1.1 markus 831: /* Login(1) does this as well, and it needs uid 0 for the "-h"
832: switch, so we let login(1) to this for us. */
833: if (!options.use_login) {
834: if (getuid() == 0 || geteuid() == 0) {
1.12.2.2 jason 835: #ifdef HAVE_LOGIN_CAP
836: if (setusercontext(lc, pw, pw->pw_uid,
837: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
838: perror("unable to set user context");
839: exit(1);
1.12.2.4! jason 840:
1.12.2.2 jason 841: }
842: #else
843: if (setlogin(pw->pw_name) < 0)
844: error("setlogin failed: %s", strerror(errno));
1.1 markus 845: if (setgid(pw->pw_gid) < 0) {
846: perror("setgid");
847: exit(1);
848: }
849: /* Initialize the group list. */
850: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
851: perror("initgroups");
852: exit(1);
853: }
854: endgrent();
855:
856: /* Permanently switch to the desired uid. */
857: permanently_set_uid(pw->pw_uid);
1.12.2.2 jason 858: #endif
1.1 markus 859: }
860: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.12.2.2 jason 861: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 862: }
863: /*
864: * Get the shell from the password data. An empty shell field is
865: * legal, and means /bin/sh.
866: */
867: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.12.2.2 jason 868: #ifdef HAVE_LOGIN_CAP
869: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
870: #endif
1.1 markus 871:
872: #ifdef AFS
873: /* Try to get AFS tokens for the local cell. */
874: if (k_hasafs()) {
875: char cell[64];
876:
877: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
878: krb_afslog(cell, 0);
879:
880: krb_afslog(0, 0);
881: }
882: #endif /* AFS */
883:
884: /* Initialize the environment. */
885: envsize = 100;
886: env = xmalloc(envsize * sizeof(char *));
887: env[0] = NULL;
888:
889: if (!options.use_login) {
890: /* Set basic environment. */
891: child_set_env(&env, &envsize, "USER", pw->pw_name);
892: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
893: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.12.2.2 jason 894: #ifdef HAVE_LOGIN_CAP
895: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
896: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
897: #else
1.1 markus 898: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.12.2.2 jason 899: #endif
1.1 markus 900:
901: snprintf(buf, sizeof buf, "%.200s/%.50s",
902: _PATH_MAILDIR, pw->pw_name);
903: child_set_env(&env, &envsize, "MAIL", buf);
904:
905: /* Normal systems set SHELL by default. */
906: child_set_env(&env, &envsize, "SHELL", shell);
907: }
908: if (getenv("TZ"))
909: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
910:
911: /* Set custom environment options from RSA authentication. */
912: while (custom_environment) {
913: struct envstring *ce = custom_environment;
914: char *s = ce->s;
915: int i;
916: for (i = 0; s[i] != '=' && s[i]; i++);
917: if (s[i] == '=') {
918: s[i] = 0;
919: child_set_env(&env, &envsize, s, s + i + 1);
920: }
921: custom_environment = ce->next;
922: xfree(ce->s);
923: xfree(ce);
924: }
925:
926: snprintf(buf, sizeof buf, "%.50s %d %d",
927: get_remote_ipaddr(), get_remote_port(), get_local_port());
928: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
929:
930: if (ttyname)
931: child_set_env(&env, &envsize, "SSH_TTY", ttyname);
932: if (term)
933: child_set_env(&env, &envsize, "TERM", term);
934: if (display)
935: child_set_env(&env, &envsize, "DISPLAY", display);
1.12.2.3 jason 936: if (original_command)
937: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
938: original_command);
1.1 markus 939:
940: #ifdef KRB4
941: {
942: extern char *ticket;
943:
944: if (ticket)
945: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
946: }
947: #endif /* KRB4 */
948:
949: if (xauthfile)
950: child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
951: if (auth_get_socket_name() != NULL)
952: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
953: auth_get_socket_name());
954:
955: /* read $HOME/.ssh/environment. */
956: if (!options.use_login) {
1.12.2.1 jason 957: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
958: pw->pw_dir);
1.1 markus 959: read_environment_file(&env, &envsize, buf);
960: }
961: if (debug_flag) {
962: /* dump the environment */
963: fprintf(stderr, "Environment:\n");
964: for (i = 0; env[i]; i++)
965: fprintf(stderr, " %.200s\n", env[i]);
966: }
1.12.2.2 jason 967: /* we have to stash the hostname before we close our socket. */
968: if (options.use_login)
969: hostname = get_remote_name_or_ip();
1.1 markus 970: /*
971: * Close the connection descriptors; note that this is the child, and
972: * the server will still have the socket open, and it is important
973: * that we do not shutdown it. Note that the descriptors cannot be
974: * closed before building the environment, as we call
975: * get_remote_ipaddr there.
976: */
977: if (packet_get_connection_in() == packet_get_connection_out())
978: close(packet_get_connection_in());
979: else {
980: close(packet_get_connection_in());
981: close(packet_get_connection_out());
982: }
983: /*
984: * Close all descriptors related to channels. They will still remain
985: * open in the parent.
986: */
987: /* XXX better use close-on-exec? -markus */
988: channel_close_all();
989:
990: /*
991: * Close any extra file descriptors. Note that there may still be
992: * descriptors left by system functions. They will be closed later.
993: */
994: endpwent();
995:
996: /*
997: * Close any extra open file descriptors so that we don\'t have them
998: * hanging around in clients. Note that we want to do this after
999: * initgroups, because at least on Solaris 2.3 it leaves file
1000: * descriptors open.
1001: */
1002: for (i = 3; i < 64; i++)
1003: close(i);
1004:
1005: /* Change current directory to the user\'s home directory. */
1.12.2.2 jason 1006: if (chdir(pw->pw_dir) < 0) {
1.1 markus 1007: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1008: pw->pw_dir, strerror(errno));
1.12.2.2 jason 1009: #ifdef HAVE_LOGIN_CAP
1010: if (login_getcapbool(lc, "requirehome", 0))
1011: exit(1);
1012: #endif
1013: }
1.1 markus 1014:
1015: /*
1016: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1017: * xauth are run in the proper environment.
1018: */
1019: environ = env;
1020:
1021: /*
1022: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1023: * in this order).
1024: */
1025: if (!options.use_login) {
1.12.2.4! jason 1026: if (stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.1 markus 1027: if (debug_flag)
1.12.2.4! jason 1028: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_USER_RC);
1.1 markus 1029:
1.12.2.4! jason 1030: f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w");
1.1 markus 1031: if (f) {
1032: if (auth_proto != NULL && auth_data != NULL)
1033: fprintf(f, "%s %s\n", auth_proto, auth_data);
1034: pclose(f);
1035: } else
1.12.2.4! jason 1036: fprintf(stderr, "Could not run %s\n", _PATH_SSH_USER_RC);
! 1037: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 1038: if (debug_flag)
1.12.2.4! jason 1039: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_SYSTEM_RC);
1.1 markus 1040:
1.12.2.4! jason 1041: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 1042: if (f) {
1043: if (auth_proto != NULL && auth_data != NULL)
1044: fprintf(f, "%s %s\n", auth_proto, auth_data);
1045: pclose(f);
1046: } else
1.12.2.4! jason 1047: fprintf(stderr, "Could not run %s\n", _PATH_SSH_SYSTEM_RC);
1.12.2.1 jason 1048: } else if (options.xauth_location != NULL) {
1.1 markus 1049: /* Add authority data to .Xauthority if appropriate. */
1050: if (auth_proto != NULL && auth_data != NULL) {
1.12.2.1 jason 1051: char *screen = strchr(display, ':');
1052: if (debug_flag) {
1053: fprintf(stderr,
1054: "Running %.100s add %.100s %.100s %.100s\n",
1055: options.xauth_location, display,
1056: auth_proto, auth_data);
1057: if (screen != NULL)
1058: fprintf(stderr,
1059: "Adding %.*s/unix%s %s %s\n",
1.12.2.2 jason 1060: (int)(screen-display), display,
1.12.2.1 jason 1061: screen, auth_proto, auth_data);
1062: }
1063: snprintf(cmd, sizeof cmd, "%s -q -",
1064: options.xauth_location);
1065: f = popen(cmd, "w");
1.1 markus 1066: if (f) {
1.12.2.1 jason 1067: fprintf(f, "add %s %s %s\n", display,
1068: auth_proto, auth_data);
1.12.2.4! jason 1069: if (screen != NULL)
1.12.2.1 jason 1070: fprintf(f, "add %.*s/unix%s %s %s\n",
1.12.2.2 jason 1071: (int)(screen-display), display,
1.12.2.1 jason 1072: screen, auth_proto, auth_data);
1.1 markus 1073: pclose(f);
1.12.2.1 jason 1074: } else {
1075: fprintf(stderr, "Could not run %s\n",
1076: cmd);
1077: }
1.1 markus 1078: }
1079: }
1080: /* Get the last component of the shell name. */
1081: cp = strrchr(shell, '/');
1082: if (cp)
1083: cp++;
1084: else
1085: cp = shell;
1086: }
1087: /*
1088: * If we have no command, execute the shell. In this case, the shell
1089: * name to be passed in argv[0] is preceded by '-' to indicate that
1090: * this is a login shell.
1091: */
1092: if (!command) {
1093: if (!options.use_login) {
1094: char buf[256];
1095:
1096: /*
1097: * Check for mail if we have a tty and it was enabled
1098: * in server options.
1099: */
1100: if (ttyname && options.check_mail) {
1101: char *mailbox;
1102: struct stat mailstat;
1103: mailbox = getenv("MAIL");
1104: if (mailbox != NULL) {
1.12.2.1 jason 1105: if (stat(mailbox, &mailstat) != 0 ||
1106: mailstat.st_size == 0)
1.1 markus 1107: printf("No mail.\n");
1108: else if (mailstat.st_mtime < mailstat.st_atime)
1109: printf("You have mail.\n");
1110: else
1111: printf("You have new mail.\n");
1112: }
1113: }
1114: /* Start the shell. Set initial character to '-'. */
1115: buf[0] = '-';
1116: strncpy(buf + 1, cp, sizeof(buf) - 1);
1117: buf[sizeof(buf) - 1] = 0;
1118:
1119: /* Execute the shell. */
1120: argv[0] = buf;
1121: argv[1] = NULL;
1122: execve(shell, argv, env);
1123:
1124: /* Executing the shell failed. */
1125: perror(shell);
1126: exit(1);
1127:
1128: } else {
1129: /* Launch login(1). */
1130:
1.12.2.2 jason 1131: execl("/usr/bin/login", "login", "-h", hostname,
1132: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1133:
1134: /* Login couldn't be executed, die. */
1135:
1136: perror("login");
1137: exit(1);
1138: }
1139: }
1140: /*
1141: * Execute the command using the user's shell. This uses the -c
1142: * option to execute the command.
1143: */
1144: argv[0] = (char *) cp;
1145: argv[1] = "-c";
1146: argv[2] = (char *) command;
1147: argv[3] = NULL;
1148: execve(shell, argv, env);
1149: perror(shell);
1150: exit(1);
1151: }
1152:
1153: Session *
1154: session_new(void)
1155: {
1156: int i;
1157: static int did_init = 0;
1158: if (!did_init) {
1159: debug("session_new: init");
1160: for(i = 0; i < MAX_SESSIONS; i++) {
1161: sessions[i].used = 0;
1162: sessions[i].self = i;
1163: }
1164: did_init = 1;
1165: }
1166: for(i = 0; i < MAX_SESSIONS; i++) {
1167: Session *s = &sessions[i];
1168: if (! s->used) {
1169: s->pid = 0;
1.7 markus 1170: s->extended = 0;
1.1 markus 1171: s->chanid = -1;
1172: s->ptyfd = -1;
1173: s->ttyfd = -1;
1174: s->term = NULL;
1175: s->pw = NULL;
1176: s->display = NULL;
1177: s->screen = 0;
1178: s->auth_data = NULL;
1179: s->auth_proto = NULL;
1180: s->used = 1;
1.7 markus 1181: s->pw = NULL;
1.1 markus 1182: debug("session_new: session %d", i);
1183: return s;
1184: }
1185: }
1186: return NULL;
1187: }
1188:
1189: void
1190: session_dump(void)
1191: {
1192: int i;
1193: for(i = 0; i < MAX_SESSIONS; i++) {
1194: Session *s = &sessions[i];
1195: debug("dump: used %d session %d %p channel %d pid %d",
1196: s->used,
1197: s->self,
1198: s,
1199: s->chanid,
1200: s->pid);
1201: }
1202: }
1203:
1.2 markus 1204: int
1205: session_open(int chanid)
1206: {
1207: Session *s = session_new();
1208: debug("session_open: channel %d", chanid);
1209: if (s == NULL) {
1210: error("no more sessions");
1211: return 0;
1212: }
1.7 markus 1213: s->pw = auth_get_user();
1214: if (s->pw == NULL)
1.12.2.4! jason 1215: fatal("no user for session %d", s->self);
1.2 markus 1216: debug("session_open: session %d: link with channel %d", s->self, chanid);
1217: s->chanid = chanid;
1218: return 1;
1219: }
1220:
1221: Session *
1222: session_by_channel(int id)
1223: {
1224: int i;
1225: for(i = 0; i < MAX_SESSIONS; i++) {
1226: Session *s = &sessions[i];
1227: if (s->used && s->chanid == id) {
1228: debug("session_by_channel: session %d channel %d", i, id);
1229: return s;
1230: }
1231: }
1232: debug("session_by_channel: unknown channel %d", id);
1233: session_dump();
1234: return NULL;
1235: }
1236:
1237: Session *
1238: session_by_pid(pid_t pid)
1239: {
1240: int i;
1241: debug("session_by_pid: pid %d", pid);
1242: for(i = 0; i < MAX_SESSIONS; i++) {
1243: Session *s = &sessions[i];
1244: if (s->used && s->pid == pid)
1245: return s;
1246: }
1247: error("session_by_pid: unknown pid %d", pid);
1248: session_dump();
1249: return NULL;
1250: }
1251:
1252: int
1253: session_window_change_req(Session *s)
1254: {
1255: s->col = packet_get_int();
1256: s->row = packet_get_int();
1257: s->xpixel = packet_get_int();
1258: s->ypixel = packet_get_int();
1.3 markus 1259: packet_done();
1.2 markus 1260: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1261: return 1;
1262: }
1263:
1264: int
1265: session_pty_req(Session *s)
1266: {
1.12.2.4! jason 1267: u_int len;
1.3 markus 1268: char *term_modes; /* encoded terminal modes */
1.2 markus 1269:
1.12.2.2 jason 1270: if (no_pty_flag)
1271: return 0;
1.2 markus 1272: if (s->ttyfd != -1)
1.3 markus 1273: return 0;
1.2 markus 1274: s->term = packet_get_string(&len);
1275: s->col = packet_get_int();
1276: s->row = packet_get_int();
1277: s->xpixel = packet_get_int();
1278: s->ypixel = packet_get_int();
1.3 markus 1279: term_modes = packet_get_string(&len);
1280: packet_done();
1.2 markus 1281:
1282: if (strcmp(s->term, "") == 0) {
1283: xfree(s->term);
1284: s->term = NULL;
1285: }
1286: /* Allocate a pty and open it. */
1287: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1288: xfree(s->term);
1289: s->term = NULL;
1290: s->ptyfd = -1;
1291: s->ttyfd = -1;
1292: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1293: xfree(term_modes);
1294: return 0;
1.2 markus 1295: }
1296: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1297: /*
1298: * Add a cleanup function to clear the utmp entry and record logout
1299: * time in case we call fatal() (e.g., the connection gets closed).
1300: */
1301: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1302: pty_setowner(s->pw, s->tty);
1303: /* Get window size from the packet. */
1304: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1305:
1.9 markus 1306: session_proctitle(s);
1307:
1.3 markus 1308: /* XXX parse and set terminal modes */
1309: xfree(term_modes);
1.2 markus 1310: return 1;
1311: }
1312:
1.7 markus 1313: int
1314: session_subsystem_req(Session *s)
1315: {
1.12.2.4! jason 1316: u_int len;
1.7 markus 1317: int success = 0;
1318: char *subsys = packet_get_string(&len);
1.12.2.2 jason 1319: int i;
1.7 markus 1320:
1321: packet_done();
1322: log("subsystem request for %s", subsys);
1323:
1.12.2.2 jason 1324: for (i = 0; i < options.num_subsystems; i++) {
1325: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1326: debug("subsystem: exec() %s", options.subsystem_command[i]);
1327: do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1328: success = 1;
1329: }
1330: }
1331:
1332: if (!success)
1333: log("subsystem request for %s failed, subsystem not found", subsys);
1334:
1.7 markus 1335: xfree(subsys);
1336: return success;
1337: }
1338:
1339: int
1340: session_x11_req(Session *s)
1341: {
1.12.2.3 jason 1342: int fd;
1.12.2.2 jason 1343: if (no_x11_forwarding_flag) {
1344: debug("X11 forwarding disabled in user configuration file.");
1345: return 0;
1346: }
1.7 markus 1347: if (!options.x11_forwarding) {
1348: debug("X11 forwarding disabled in server configuration file.");
1349: return 0;
1350: }
1351: if (xauthfile != NULL) {
1352: debug("X11 fwd already started.");
1353: return 0;
1354: }
1355:
1356: debug("Received request for X11 forwarding with auth spoofing.");
1357: if (s->display != NULL)
1358: packet_disconnect("Protocol error: X11 display already set.");
1359:
1360: s->single_connection = packet_get_char();
1361: s->auth_proto = packet_get_string(NULL);
1362: s->auth_data = packet_get_string(NULL);
1363: s->screen = packet_get_int();
1364: packet_done();
1365:
1366: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1367: if (s->display == NULL) {
1368: xfree(s->auth_proto);
1369: xfree(s->auth_data);
1370: return 0;
1371: }
1372: xauthfile = xmalloc(MAXPATHLEN);
1373: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1374: temporarily_use_uid(s->pw->pw_uid);
1375: if (mkdtemp(xauthfile) == NULL) {
1376: restore_uid();
1377: error("private X11 dir: mkdtemp %s failed: %s",
1378: xauthfile, strerror(errno));
1379: xfree(xauthfile);
1380: xauthfile = NULL;
1381: xfree(s->auth_proto);
1382: xfree(s->auth_data);
1383: /* XXXX remove listening channels */
1384: return 0;
1385: }
1386: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.12.2.3 jason 1387: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1388: if (fd >= 0)
1389: close(fd);
1.7 markus 1390: restore_uid();
1391: fatal_add_cleanup(xauthfile_cleanup_proc, s);
1392: return 1;
1393: }
1394:
1.12.2.2 jason 1395: int
1396: session_shell_req(Session *s)
1397: {
1398: /* if forced_command == NULL, the shell is execed */
1399: char *shell = forced_command;
1400: packet_done();
1401: s->extended = 1;
1402: if (s->ttyfd == -1)
1403: do_exec_no_pty(s, shell, s->pw);
1404: else
1405: do_exec_pty(s, shell, s->pw);
1406: return 1;
1407: }
1408:
1409: int
1410: session_exec_req(Session *s)
1411: {
1.12.2.4! jason 1412: u_int len;
1.12.2.2 jason 1413: char *command = packet_get_string(&len);
1414: packet_done();
1415: if (forced_command) {
1.12.2.3 jason 1416: original_command = command;
1.12.2.2 jason 1417: command = forced_command;
1418: debug("Forced command '%.500s'", forced_command);
1419: }
1420: s->extended = 1;
1421: if (s->ttyfd == -1)
1422: do_exec_no_pty(s, command, s->pw);
1423: else
1424: do_exec_pty(s, command, s->pw);
1425: if (forced_command == NULL)
1426: xfree(command);
1427: return 1;
1428: }
1429:
1.12.2.4! jason 1430: int
! 1431: session_auth_agent_req(Session *s)
! 1432: {
! 1433: static int called = 0;
! 1434: packet_done();
! 1435: if (no_agent_forwarding_flag) {
! 1436: debug("session_auth_agent_req: no_agent_forwarding_flag");
! 1437: return 0;
! 1438: }
! 1439: if (called) {
! 1440: return 0;
! 1441: } else {
! 1442: called = 1;
! 1443: return auth_input_request_forwarding(s->pw);
! 1444: }
! 1445: }
! 1446:
1.2 markus 1447: void
1448: session_input_channel_req(int id, void *arg)
1449: {
1.12.2.4! jason 1450: u_int len;
1.2 markus 1451: int reply;
1452: int success = 0;
1453: char *rtype;
1454: Session *s;
1455: Channel *c;
1456:
1457: rtype = packet_get_string(&len);
1458: reply = packet_get_char();
1459:
1460: s = session_by_channel(id);
1461: if (s == NULL)
1462: fatal("session_input_channel_req: channel %d: no session", id);
1463: c = channel_lookup(id);
1464: if (c == NULL)
1465: fatal("session_input_channel_req: channel %d: bad channel", id);
1466:
1467: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1468: s->self, id, rtype, reply);
1469:
1470: /*
1471: * a session is in LARVAL state until a shell
1472: * or programm is executed
1473: */
1474: if (c->type == SSH_CHANNEL_LARVAL) {
1475: if (strcmp(rtype, "shell") == 0) {
1.12.2.2 jason 1476: success = session_shell_req(s);
1.2 markus 1477: } else if (strcmp(rtype, "exec") == 0) {
1.12.2.2 jason 1478: success = session_exec_req(s);
1.2 markus 1479: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1480: success = session_pty_req(s);
1.7 markus 1481: } else if (strcmp(rtype, "x11-req") == 0) {
1482: success = session_x11_req(s);
1.12.2.4! jason 1483: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
! 1484: success = session_auth_agent_req(s);
1.7 markus 1485: } else if (strcmp(rtype, "subsystem") == 0) {
1486: success = session_subsystem_req(s);
1.2 markus 1487: }
1488: }
1489: if (strcmp(rtype, "window-change") == 0) {
1490: success = session_window_change_req(s);
1491: }
1492:
1493: if (reply) {
1494: packet_start(success ?
1495: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1496: packet_put_int(c->remote_id);
1497: packet_send();
1498: }
1499: xfree(rtype);
1500: }
1501:
1502: void
1503: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1504: {
1505: if (!compat20)
1506: fatal("session_set_fds: called for proto != 2.0");
1507: /*
1508: * now that have a child and a pipe to the child,
1509: * we can activate our channel and register the fd's
1510: */
1511: if (s->chanid == -1)
1512: fatal("no channel for session %d", s->self);
1513: channel_set_fds(s->chanid,
1514: fdout, fdin, fderr,
1.12.2.3 jason 1515: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1516: 1);
1.2 markus 1517: }
1518:
1.1 markus 1519: void
1520: session_pty_cleanup(Session *s)
1521: {
1522: if (s == NULL || s->ttyfd == -1)
1523: return;
1524:
1.12.2.4! jason 1525: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1526:
1527: /* Cancel the cleanup function. */
1528: fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1529:
1530: /* Record that the user has logged out. */
1531: record_logout(s->pid, s->tty);
1532:
1533: /* Release the pseudo-tty. */
1534: pty_release(s->tty);
1535:
1536: /*
1537: * Close the server side of the socket pairs. We must do this after
1538: * the pty cleanup, so that another process doesn't get this pty
1539: * while we're still cleaning up.
1540: */
1541: if (close(s->ptymaster) < 0)
1542: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1543: }
1544:
1545: void
1546: session_exit_message(Session *s, int status)
1547: {
1548: Channel *c;
1549: if (s == NULL)
1550: fatal("session_close: no session");
1551: c = channel_lookup(s->chanid);
1552: if (c == NULL)
1553: fatal("session_close: session %d: no channel %d",
1554: s->self, s->chanid);
1555: debug("session_exit_message: session %d channel %d pid %d",
1556: s->self, s->chanid, s->pid);
1557:
1558: if (WIFEXITED(status)) {
1559: channel_request_start(s->chanid,
1560: "exit-status", 0);
1561: packet_put_int(WEXITSTATUS(status));
1562: packet_send();
1563: } else if (WIFSIGNALED(status)) {
1564: channel_request_start(s->chanid,
1565: "exit-signal", 0);
1566: packet_put_int(WTERMSIG(status));
1567: packet_put_char(WCOREDUMP(status));
1568: packet_put_cstring("");
1569: packet_put_cstring("");
1570: packet_send();
1571: } else {
1572: /* Some weird exit cause. Just exit. */
1573: packet_disconnect("wait returned status %04x.", status);
1574: }
1575:
1576: /* disconnect channel */
1577: debug("session_exit_message: release channel %d", s->chanid);
1578: channel_cancel_cleanup(s->chanid);
1.5 markus 1579: /*
1580: * emulate a write failure with 'chan_write_failed', nobody will be
1581: * interested in data we write.
1582: * Note that we must not call 'chan_read_failed', since there could
1583: * be some more data waiting in the pipe.
1584: */
1.8 markus 1585: if (c->ostate != CHAN_OUTPUT_CLOSED)
1586: chan_write_failed(c);
1.2 markus 1587: s->chanid = -1;
1588: }
1589:
1590: void
1591: session_free(Session *s)
1592: {
1593: debug("session_free: session %d pid %d", s->self, s->pid);
1594: if (s->term)
1595: xfree(s->term);
1596: if (s->display)
1597: xfree(s->display);
1598: if (s->auth_data)
1599: xfree(s->auth_data);
1600: if (s->auth_proto)
1601: xfree(s->auth_proto);
1602: s->used = 0;
1603: }
1604:
1605: void
1606: session_close(Session *s)
1607: {
1608: session_pty_cleanup(s);
1609: session_free(s);
1.9 markus 1610: session_proctitle(s);
1.2 markus 1611: }
1612:
1613: void
1614: session_close_by_pid(pid_t pid, int status)
1615: {
1616: Session *s = session_by_pid(pid);
1617: if (s == NULL) {
1618: debug("session_close_by_pid: no session for pid %d", s->pid);
1619: return;
1620: }
1621: if (s->chanid != -1)
1622: session_exit_message(s, status);
1623: session_close(s);
1624: }
1625:
1626: /*
1627: * this is called when a channel dies before
1628: * the session 'child' itself dies
1629: */
1630: void
1631: session_close_by_channel(int id, void *arg)
1632: {
1633: Session *s = session_by_channel(id);
1634: if (s == NULL) {
1635: debug("session_close_by_channel: no session for channel %d", id);
1636: return;
1637: }
1638: /* disconnect channel */
1639: channel_cancel_cleanup(s->chanid);
1640: s->chanid = -1;
1641:
1642: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1643: if (s->pid == 0) {
1644: /* close session immediately */
1645: session_close(s);
1646: } else {
1647: /* notify child, delay session cleanup */
1648: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1649: error("session_close_by_channel: kill %d: %s",
1650: s->pid, strerror(errno));
1651: }
1.9 markus 1652: }
1653:
1654: char *
1655: session_tty_list(void)
1656: {
1657: static char buf[1024];
1658: int i;
1659: buf[0] = '\0';
1660: for(i = 0; i < MAX_SESSIONS; i++) {
1661: Session *s = &sessions[i];
1662: if (s->used && s->ttyfd != -1) {
1663: if (buf[0] != '\0')
1664: strlcat(buf, ",", sizeof buf);
1665: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1666: }
1667: }
1668: if (buf[0] == '\0')
1669: strlcpy(buf, "notty", sizeof buf);
1670: return buf;
1671: }
1672:
1673: void
1674: session_proctitle(Session *s)
1675: {
1676: if (s->pw == NULL)
1677: error("no user for session %d", s->self);
1678: else
1679: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1680: }
1681:
1682: void
1.12.2.4! jason 1683: do_authenticated2(Authctxt *authctxt)
1.2 markus 1684: {
1685: /*
1686: * Cancel the alarm we set to limit the time taken for
1687: * authentication.
1688: */
1689: alarm(0);
1.12.2.2 jason 1690: if (startup_pipe != -1) {
1691: close(startup_pipe);
1692: startup_pipe = -1;
1693: }
1694: #ifdef HAVE_LOGIN_CAP
1.12.2.4! jason 1695: if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
1.12.2.2 jason 1696: error("unable to get login class");
1697: return;
1698: }
1699: #endif
1.2 markus 1700: server_loop2();
1.7 markus 1701: if (xauthfile)
1702: xauthfile_cleanup_proc(NULL);
1.1 markus 1703: }
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