Annotation of src/usr.bin/ssh/session.c, Revision 1.61
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.
1.58 deraadt 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"
1.61 ! markus 36: RCSID("$OpenBSD: session.c,v 1.60 2001/03/15 22:07:08 markus Exp $");
1.1 markus 37:
1.51 markus 38: #include "ssh.h"
39: #include "ssh1.h"
40: #include "ssh2.h"
1.1 markus 41: #include "xmalloc.h"
1.59 djm 42: #include "sshpty.h"
1.1 markus 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"
1.19 markus 52: #include "auth-options.h"
1.50 markus 53: #include "pathnames.h"
1.51 markus 54: #include "log.h"
55: #include "servconf.h"
1.59 djm 56: #include "sshlogin.h"
1.51 markus 57: #include "serverloop.h"
58: #include "canohost.h"
1.55 itojun 59: #include "session.h"
1.2 markus 60:
1.28 millert 61: #ifdef HAVE_LOGIN_CAP
62: #include <login_cap.h>
63: #endif
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);
1.41 markus 98: void do_login(Session *s, const char *command);
1.60 markus 99: void do_child(Session *s, const char *command);
1.1 markus 100:
101: /* import */
102: extern ServerOptions options;
103: extern char *__progname;
104: extern int log_stderr;
105: extern int debug_flag;
1.45 markus 106: extern u_int utmp_len;
1.1 markus 107:
1.21 markus 108: extern int startup_pipe;
109:
1.1 markus 110: /* Local Xauthority file. */
111: static char *xauthfile;
112:
1.34 markus 113: /* original command from peer. */
1.53 stevesk 114: char *original_command = NULL;
1.34 markus 115:
1.1 markus 116: /* data */
117: #define MAX_SESSIONS 10
118: Session sessions[MAX_SESSIONS];
119:
1.28 millert 120: #ifdef HAVE_LOGIN_CAP
121: static login_cap_t *lc;
122: #endif
123:
1.1 markus 124: /*
125: * Remove local Xauthority file.
126: */
127: void
128: xauthfile_cleanup_proc(void *ignore)
129: {
130: debug("xauthfile_cleanup_proc called");
131:
132: if (xauthfile != NULL) {
133: char *p;
134: unlink(xauthfile);
135: p = strrchr(xauthfile, '/');
136: if (p != NULL) {
137: *p = '\0';
138: rmdir(xauthfile);
139: }
140: xfree(xauthfile);
141: xauthfile = NULL;
142: }
143: }
144:
145: /*
146: * Function to perform cleanup if we get aborted abnormally (e.g., due to a
147: * dropped connection).
148: */
1.4 markus 149: void
1.1 markus 150: pty_cleanup_proc(void *session)
151: {
152: Session *s=session;
153: if (s == NULL)
154: fatal("pty_cleanup_proc: no session");
155: debug("pty_cleanup_proc: %s", s->tty);
156:
157: if (s->pid != 0) {
158: /* Record that the user has logged out. */
159: record_logout(s->pid, s->tty);
160: }
161:
162: /* Release the pseudo-tty. */
163: pty_release(s->tty);
164: }
165:
166: /*
167: * Prepares for an interactive session. This is called after the user has
168: * been successfully authenticated. During this message exchange, pseudo
169: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
170: * are requested, etc.
171: */
1.4 markus 172: void
1.1 markus 173: do_authenticated(struct passwd * pw)
174: {
175: Session *s;
1.33 markus 176: int type, fd;
1.1 markus 177: int compression_level = 0, enable_compression_after_reply = 0;
178: int have_pty = 0;
179: char *command;
180: int n_bytes;
181: int plen;
1.45 markus 182: u_int proto_len, data_len, dlen;
1.57 markus 183: int screen_flag;
1.1 markus 184:
185: /*
186: * Cancel the alarm we set to limit the time taken for
187: * authentication.
188: */
189: alarm(0);
1.23 deraadt 190: if (startup_pipe != -1) {
191: close(startup_pipe);
192: startup_pipe = -1;
193: }
1.1 markus 194:
1.61 ! markus 195: s = session_new();
! 196: s->pw = pw;
! 197:
1.39 markus 198: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
1.1 markus 199: channel_permit_all_opens();
200:
1.28 millert 201: #ifdef HAVE_LOGIN_CAP
202: if ((lc = login_getclass(pw->pw_class)) == NULL) {
203: error("unable to get login class");
204: return;
205: }
206: #endif
207:
1.1 markus 208: /*
209: * We stay in this loop until the client requests to execute a shell
210: * or a command.
211: */
212: for (;;) {
213: int success = 0;
214:
215: /* Get a packet from the client. */
216: type = packet_read(&plen);
217:
218: /* Process the packet. */
219: switch (type) {
220: case SSH_CMSG_REQUEST_COMPRESSION:
221: packet_integrity_check(plen, 4, type);
222: compression_level = packet_get_int();
223: if (compression_level < 1 || compression_level > 9) {
224: packet_send_debug("Received illegal compression level %d.",
225: compression_level);
226: break;
227: }
228: /* Enable compression after we have responded with SUCCESS. */
229: enable_compression_after_reply = 1;
230: success = 1;
231: break;
232:
233: case SSH_CMSG_REQUEST_PTY:
234: if (no_pty_flag) {
235: debug("Allocating a pty not permitted for this authentication.");
236: break;
237: }
238: if (have_pty)
239: packet_disconnect("Protocol error: you already have a pty.");
240:
241: debug("Allocating pty.");
242:
243: /* Allocate a pty and open it. */
244: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
245: sizeof(s->tty))) {
246: error("Failed to allocate pty.");
247: break;
248: }
249: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
250: pty_setowner(pw, s->tty);
251:
252: /* Get TERM from the packet. Note that the value may be of arbitrary length. */
253: s->term = packet_get_string(&dlen);
254: packet_integrity_check(dlen, strlen(s->term), type);
255: /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
256: /* Remaining bytes */
257: n_bytes = plen - (4 + dlen + 4 * 4);
258:
259: if (strcmp(s->term, "") == 0) {
260: xfree(s->term);
261: s->term = NULL;
262: }
263: /* Get window size from the packet. */
264: s->row = packet_get_int();
265: s->col = packet_get_int();
266: s->xpixel = packet_get_int();
267: s->ypixel = packet_get_int();
268: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
269:
270: /* Get tty modes from the packet. */
271: tty_parse_modes(s->ttyfd, &n_bytes);
272: packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
1.10 markus 273:
274: session_proctitle(s);
1.1 markus 275:
276: /* Indicate that we now have a pty. */
277: success = 1;
278: have_pty = 1;
279: break;
280:
281: case SSH_CMSG_X11_REQUEST_FORWARDING:
282: if (!options.x11_forwarding) {
283: packet_send_debug("X11 forwarding disabled in server configuration file.");
284: break;
285: }
1.16 markus 286: if (!options.xauth_location) {
287: packet_send_debug("No xauth program; cannot forward with spoofing.");
288: break;
289: }
1.1 markus 290: if (no_x11_forwarding_flag) {
291: packet_send_debug("X11 forwarding not permitted for this authentication.");
292: break;
293: }
294: debug("Received request for X11 forwarding with auth spoofing.");
295: if (s->display != NULL)
296: packet_disconnect("Protocol error: X11 display already set.");
297:
298: s->auth_proto = packet_get_string(&proto_len);
299: s->auth_data = packet_get_string(&data_len);
300:
1.57 markus 301: screen_flag = packet_get_protocol_flags() &
302: SSH_PROTOFLAG_SCREEN_NUMBER;
303: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
304:
305: if (packet_remaining() == 4) {
306: if (!screen_flag)
307: debug2("Buggy client: "
308: "X11 screen flag missing");
1.56 markus 309: packet_integrity_check(plen,
310: 4 + proto_len + 4 + data_len + 4, type);
1.1 markus 311: s->screen = packet_get_int();
1.56 markus 312: } else {
313: packet_integrity_check(plen,
314: 4 + proto_len + 4 + data_len, type);
1.1 markus 315: s->screen = 0;
1.56 markus 316: }
1.1 markus 317: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
318:
319: if (s->display == NULL)
320: break;
321:
322: /* Setup to always have a local .Xauthority. */
323: xauthfile = xmalloc(MAXPATHLEN);
324: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
325: temporarily_use_uid(pw->pw_uid);
326: if (mkdtemp(xauthfile) == NULL) {
327: restore_uid();
328: error("private X11 dir: mkdtemp %s failed: %s",
329: xauthfile, strerror(errno));
330: xfree(xauthfile);
331: xauthfile = NULL;
1.7 markus 332: /* XXXX remove listening channels */
1.1 markus 333: break;
334: }
335: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 336: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
337: if (fd >= 0)
338: close(fd);
1.1 markus 339: restore_uid();
340: fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
341: success = 1;
342: break;
343:
344: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
345: if (no_agent_forwarding_flag || compat13) {
346: debug("Authentication agent forwarding not permitted for this authentication.");
347: break;
348: }
349: debug("Received authentication agent forwarding request.");
1.15 markus 350: success = auth_input_request_forwarding(pw);
1.1 markus 351: break;
352:
353: case SSH_CMSG_PORT_FORWARD_REQUEST:
354: if (no_port_forwarding_flag) {
355: debug("Port forwarding not permitted for this authentication.");
1.39 markus 356: break;
357: }
358: if (!options.allow_tcp_forwarding) {
359: debug("Port forwarding not permitted.");
1.1 markus 360: break;
361: }
362: debug("Received TCP/IP port forwarding request.");
1.12 markus 363: channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
1.1 markus 364: success = 1;
365: break;
366:
367: case SSH_CMSG_MAX_PACKET_SIZE:
368: if (packet_set_maxsize(packet_get_int()) > 0)
369: success = 1;
370: break;
371:
372: case SSH_CMSG_EXEC_SHELL:
373: case SSH_CMSG_EXEC_CMD:
374: if (type == SSH_CMSG_EXEC_CMD) {
375: command = packet_get_string(&dlen);
376: debug("Exec command '%.500s'", command);
377: packet_integrity_check(plen, 4 + dlen, type);
378: } else {
379: command = NULL;
380: packet_integrity_check(plen, 0, type);
381: }
382: if (forced_command != NULL) {
1.34 markus 383: original_command = command;
1.1 markus 384: command = forced_command;
385: debug("Forced command '%.500s'", forced_command);
386: }
387: if (have_pty)
388: do_exec_pty(s, command, pw);
389: else
390: do_exec_no_pty(s, command, pw);
391:
392: if (command != NULL)
393: xfree(command);
394: /* Cleanup user's local Xauthority file. */
395: if (xauthfile)
396: xauthfile_cleanup_proc(NULL);
397: return;
398:
399: default:
400: /*
401: * Any unknown messages in this phase are ignored,
402: * and a failure message is returned.
403: */
404: log("Unknown packet type received after authentication: %d", type);
405: }
406: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
407: packet_send();
408: packet_write_wait();
409:
410: /* Enable compression now that we have replied if appropriate. */
411: if (enable_compression_after_reply) {
412: enable_compression_after_reply = 0;
413: packet_start_compression(compression_level);
414: }
415: }
416: }
417:
418: /*
419: * This is called to fork and execute a command when we have no tty. This
420: * will call do_child from the child, and server_loop from the parent after
421: * setting up file descriptors and such.
422: */
1.4 markus 423: void
1.1 markus 424: do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
425: {
426: int pid;
427:
428: #ifdef USE_PIPES
429: int pin[2], pout[2], perr[2];
430: /* Allocate pipes for communicating with the program. */
431: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
432: packet_disconnect("Could not create pipes: %.100s",
433: strerror(errno));
434: #else /* USE_PIPES */
435: int inout[2], err[2];
436: /* Uses socket pairs to communicate with the program. */
437: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
438: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
439: packet_disconnect("Could not create socket pairs: %.100s",
440: strerror(errno));
441: #endif /* USE_PIPES */
442: if (s == NULL)
443: fatal("do_exec_no_pty: no session");
444:
1.9 markus 445: session_proctitle(s);
1.1 markus 446:
447: /* Fork the child. */
448: if ((pid = fork()) == 0) {
449: /* Child. Reinitialize the log since the pid has changed. */
450: log_init(__progname, options.log_level, options.log_facility, log_stderr);
451:
452: /*
453: * Create a new session and process group since the 4.4BSD
454: * setlogin() affects the entire process group.
455: */
456: if (setsid() < 0)
457: error("setsid failed: %.100s", strerror(errno));
458:
459: #ifdef USE_PIPES
460: /*
461: * Redirect stdin. We close the parent side of the socket
462: * pair, and make the child side the standard input.
463: */
464: close(pin[1]);
465: if (dup2(pin[0], 0) < 0)
466: perror("dup2 stdin");
467: close(pin[0]);
468:
469: /* Redirect stdout. */
470: close(pout[0]);
471: if (dup2(pout[1], 1) < 0)
472: perror("dup2 stdout");
473: close(pout[1]);
474:
475: /* Redirect stderr. */
476: close(perr[0]);
477: if (dup2(perr[1], 2) < 0)
478: perror("dup2 stderr");
479: close(perr[1]);
480: #else /* USE_PIPES */
481: /*
482: * Redirect stdin, stdout, and stderr. Stdin and stdout will
483: * use the same socket, as some programs (particularly rdist)
484: * seem to depend on it.
485: */
486: close(inout[1]);
487: close(err[1]);
488: if (dup2(inout[0], 0) < 0) /* stdin */
489: perror("dup2 stdin");
490: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
491: perror("dup2 stdout");
492: if (dup2(err[0], 2) < 0) /* stderr */
493: perror("dup2 stderr");
494: #endif /* USE_PIPES */
495:
496: /* Do processing for the child (exec command etc). */
1.60 markus 497: do_child(s, command);
1.1 markus 498: /* NOTREACHED */
499: }
500: if (pid < 0)
501: packet_disconnect("fork failed: %.100s", strerror(errno));
502: s->pid = pid;
1.47 markus 503: /* Set interactive/non-interactive mode. */
1.48 markus 504: packet_set_interactive(s->display != NULL);
1.1 markus 505: #ifdef USE_PIPES
506: /* We are the parent. Close the child sides of the pipes. */
507: close(pin[0]);
508: close(pout[1]);
509: close(perr[1]);
510:
1.2 markus 511: if (compat20) {
1.7 markus 512: session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
1.2 markus 513: } else {
514: /* Enter the interactive session. */
515: server_loop(pid, pin[1], pout[0], perr[0]);
516: /* server_loop has closed pin[1], pout[1], and perr[1]. */
517: }
1.1 markus 518: #else /* USE_PIPES */
519: /* We are the parent. Close the child sides of the socket pairs. */
520: close(inout[0]);
521: close(err[0]);
522:
523: /*
524: * Enter the interactive session. Note: server_loop must be able to
525: * handle the case that fdin and fdout are the same.
526: */
1.2 markus 527: if (compat20) {
1.7 markus 528: session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
1.2 markus 529: } else {
530: server_loop(pid, inout[1], inout[1], err[1]);
531: /* server_loop has closed inout[1] and err[1]. */
532: }
1.1 markus 533: #endif /* USE_PIPES */
534: }
535:
536: /*
537: * This is called to fork and execute a command when we have a tty. This
538: * will call do_child from the child, and server_loop from the parent after
539: * setting up file descriptors, controlling tty, updating wtmp, utmp,
540: * lastlog, and other such operations.
541: */
1.4 markus 542: void
1.1 markus 543: do_exec_pty(Session *s, const char *command, struct passwd * pw)
544: {
545: int fdout, ptyfd, ttyfd, ptymaster;
546: pid_t pid;
547:
548: if (s == NULL)
549: fatal("do_exec_pty: no session");
550: ptyfd = s->ptyfd;
551: ttyfd = s->ttyfd;
552:
553: /* Fork the child. */
554: if ((pid = fork()) == 0) {
1.24 markus 555: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 556: log_init(__progname, options.log_level, options.log_facility, log_stderr);
557:
558: /* Close the master side of the pseudo tty. */
559: close(ptyfd);
560:
561: /* Make the pseudo tty our controlling tty. */
562: pty_make_controlling_tty(&ttyfd, s->tty);
563:
564: /* Redirect stdin from the pseudo tty. */
565: if (dup2(ttyfd, fileno(stdin)) < 0)
566: error("dup2 stdin failed: %.100s", strerror(errno));
567:
568: /* Redirect stdout to the pseudo tty. */
569: if (dup2(ttyfd, fileno(stdout)) < 0)
570: error("dup2 stdin failed: %.100s", strerror(errno));
571:
572: /* Redirect stderr to the pseudo tty. */
573: if (dup2(ttyfd, fileno(stderr)) < 0)
574: error("dup2 stdin failed: %.100s", strerror(errno));
575:
576: /* Close the extra descriptor for the pseudo tty. */
577: close(ttyfd);
578:
1.24 markus 579: /* record login, etc. similar to login(1) */
1.41 markus 580: if (!(options.use_login && command == NULL))
581: do_login(s, command);
1.1 markus 582:
583: /* Do common processing for the child, such as execing the command. */
1.60 markus 584: do_child(s, command);
1.1 markus 585: /* NOTREACHED */
586: }
587: if (pid < 0)
588: packet_disconnect("fork failed: %.100s", strerror(errno));
589: s->pid = pid;
590:
591: /* Parent. Close the slave side of the pseudo tty. */
592: close(ttyfd);
593:
594: /*
595: * Create another descriptor of the pty master side for use as the
596: * standard input. We could use the original descriptor, but this
597: * simplifies code in server_loop. The descriptor is bidirectional.
598: */
599: fdout = dup(ptyfd);
600: if (fdout < 0)
601: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
602:
603: /* we keep a reference to the pty master */
604: ptymaster = dup(ptyfd);
605: if (ptymaster < 0)
606: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
607: s->ptymaster = ptymaster;
608:
609: /* Enter interactive session. */
1.47 markus 610: packet_set_interactive(1);
1.2 markus 611: if (compat20) {
612: session_set_fds(s, ptyfd, fdout, -1);
613: } else {
614: server_loop(pid, ptyfd, fdout, -1);
615: /* server_loop _has_ closed ptyfd and fdout. */
616: session_pty_cleanup(s);
1.24 markus 617: }
618: }
619:
1.25 markus 620: const char *
621: get_remote_name_or_ip(void)
622: {
623: static const char *remote = "";
624: if (utmp_len > 0)
1.52 markus 625: remote = get_canonical_hostname(options.reverse_mapping_check);
1.25 markus 626: if (utmp_len == 0 || strlen(remote) > utmp_len)
627: remote = get_remote_ipaddr();
628: return remote;
629: }
630:
1.24 markus 631: /* administrative, login(1)-like work */
632: void
1.41 markus 633: do_login(Session *s, const char *command)
1.24 markus 634: {
635: FILE *f;
636: char *time_string;
637: char buf[256];
1.35 markus 638: char hostname[MAXHOSTNAMELEN];
1.24 markus 639: socklen_t fromlen;
640: struct sockaddr_storage from;
641: struct stat st;
642: time_t last_login_time;
643: struct passwd * pw = s->pw;
644: pid_t pid = getpid();
645:
646: /*
647: * Get IP address of client. If the connection is not a socket, let
648: * the address be 0.0.0.0.
649: */
650: memset(&from, 0, sizeof(from));
651: if (packet_connection_is_on_socket()) {
652: fromlen = sizeof(from);
653: if (getpeername(packet_get_connection_in(),
654: (struct sockaddr *) & from, &fromlen) < 0) {
655: debug("getpeername: %.100s", strerror(errno));
656: fatal_cleanup();
657: }
658: }
1.25 markus 659:
1.35 markus 660: /* Get the time and hostname when the user last logged in. */
1.36 markus 661: hostname[0] = '\0';
1.35 markus 662: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
663: hostname, sizeof(hostname));
664:
1.24 markus 665: /* Record that there was a login on that tty from the remote host. */
666: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.25 markus 667: get_remote_name_or_ip(), (struct sockaddr *)&from);
1.24 markus 668:
1.41 markus 669: /* Done if .hushlogin exists or a command given. */
670: if (command != NULL)
671: return;
1.24 markus 672: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
1.28 millert 673: #ifdef HAVE_LOGIN_CAP
674: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
675: #else
1.24 markus 676: if (stat(buf, &st) >= 0)
1.28 millert 677: #endif
1.24 markus 678: return;
679: if (last_login_time != 0) {
680: time_string = ctime(&last_login_time);
681: if (strchr(time_string, '\n'))
682: *strchr(time_string, '\n') = 0;
1.40 markus 683: if (strcmp(hostname, "") == 0)
1.24 markus 684: printf("Last login: %s\r\n", time_string);
685: else
1.36 markus 686: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 687: }
688: if (options.print_motd) {
1.28 millert 689: #ifdef HAVE_LOGIN_CAP
690: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
691: "/etc/motd"), "r");
692: #else
1.24 markus 693: f = fopen("/etc/motd", "r");
1.28 millert 694: #endif
1.24 markus 695: if (f) {
696: while (fgets(buf, sizeof(buf), f))
697: fputs(buf, stdout);
698: fclose(f);
699: }
1.2 markus 700: }
1.1 markus 701: }
702:
703: /*
704: * Sets the value of the given variable in the environment. If the variable
705: * already exists, its value is overriden.
706: */
1.4 markus 707: void
1.45 markus 708: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 709: const char *value)
710: {
1.45 markus 711: u_int i, namelen;
1.1 markus 712: char **env;
713:
714: /*
715: * Find the slot where the value should be stored. If the variable
716: * already exists, we reuse the slot; otherwise we append a new slot
717: * at the end of the array, expanding if necessary.
718: */
719: env = *envp;
720: namelen = strlen(name);
721: for (i = 0; env[i]; i++)
722: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
723: break;
724: if (env[i]) {
725: /* Reuse the slot. */
726: xfree(env[i]);
727: } else {
728: /* New variable. Expand if necessary. */
729: if (i >= (*envsizep) - 1) {
730: (*envsizep) += 50;
731: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
732: }
733: /* Need to set the NULL pointer at end of array beyond the new slot. */
734: env[i + 1] = NULL;
735: }
736:
737: /* Allocate space and format the variable in the appropriate slot. */
738: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
739: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
740: }
741:
742: /*
743: * Reads environment variables from the given file and adds/overrides them
744: * into the environment. If the file does not exist, this does nothing.
745: * Otherwise, it must consist of empty lines, comments (line starts with '#')
746: * and assignments of the form name=value. No other forms are allowed.
747: */
1.4 markus 748: void
1.45 markus 749: read_environment_file(char ***env, u_int *envsize,
1.1 markus 750: const char *filename)
751: {
752: FILE *f;
753: char buf[4096];
754: char *cp, *value;
755:
756: f = fopen(filename, "r");
757: if (!f)
758: return;
759:
760: while (fgets(buf, sizeof(buf), f)) {
761: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
762: ;
763: if (!*cp || *cp == '#' || *cp == '\n')
764: continue;
765: if (strchr(cp, '\n'))
766: *strchr(cp, '\n') = '\0';
767: value = strchr(cp, '=');
768: if (value == NULL) {
769: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
770: continue;
771: }
1.14 deraadt 772: /*
773: * Replace the equals sign by nul, and advance value to
774: * the value string.
775: */
1.1 markus 776: *value = '\0';
777: value++;
778: child_set_env(env, envsize, cp, value);
779: }
780: fclose(f);
781: }
782:
783: /*
784: * Performs common processing for the child, such as setting up the
785: * environment, closing extra file descriptors, setting the user and group
786: * ids, and executing the command or shell.
787: */
1.4 markus 788: void
1.60 markus 789: do_child(Session *s, const char *command)
1.1 markus 790: {
1.32 markus 791: const char *shell, *hostname = NULL, *cp = NULL;
1.60 markus 792: struct passwd * pw = s->pw;
1.1 markus 793: char buf[256];
1.16 markus 794: char cmd[1024];
1.27 millert 795: FILE *f = NULL;
1.45 markus 796: u_int envsize, i;
1.1 markus 797: char **env;
798: extern char **environ;
799: struct stat st;
800: char *argv[10];
1.60 markus 801: int do_xauth = s->auth_proto != NULL && s->auth_data != NULL;
1.17 markus 802:
803: /* login(1) is only called if we execute the login shell */
804: if (options.use_login && command != NULL)
805: options.use_login = 0;
1.1 markus 806:
1.27 millert 807: if (!options.use_login) {
1.28 millert 808: #ifdef HAVE_LOGIN_CAP
809: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
810: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
811: _PATH_NOLOGIN), "r");
812: #else
1.27 millert 813: if (pw->pw_uid)
814: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 815: #endif
1.27 millert 816: if (f) {
817: /* /etc/nologin exists. Print its contents and exit. */
818: while (fgets(buf, sizeof(buf), f))
819: fputs(buf, stderr);
820: fclose(f);
1.1 markus 821: exit(254);
1.27 millert 822: }
1.1 markus 823: }
1.28 millert 824: /* Set login name, uid, gid, and groups. */
1.1 markus 825: /* Login(1) does this as well, and it needs uid 0 for the "-h"
826: switch, so we let login(1) to this for us. */
827: if (!options.use_login) {
828: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 829: #ifdef HAVE_LOGIN_CAP
830: if (setusercontext(lc, pw, pw->pw_uid,
831: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
832: perror("unable to set user context");
833: exit(1);
1.53 stevesk 834:
1.28 millert 835: }
836: #else
837: if (setlogin(pw->pw_name) < 0)
838: error("setlogin failed: %s", strerror(errno));
1.1 markus 839: if (setgid(pw->pw_gid) < 0) {
840: perror("setgid");
841: exit(1);
842: }
843: /* Initialize the group list. */
844: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
845: perror("initgroups");
846: exit(1);
847: }
848: endgrent();
849:
850: /* Permanently switch to the desired uid. */
851: permanently_set_uid(pw->pw_uid);
1.28 millert 852: #endif
1.1 markus 853: }
854: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 855: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 856: }
857: /*
858: * Get the shell from the password data. An empty shell field is
859: * legal, and means /bin/sh.
860: */
861: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 862: #ifdef HAVE_LOGIN_CAP
863: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
864: #endif
1.1 markus 865:
866: #ifdef AFS
867: /* Try to get AFS tokens for the local cell. */
868: if (k_hasafs()) {
869: char cell[64];
870:
871: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
872: krb_afslog(cell, 0);
873:
874: krb_afslog(0, 0);
875: }
876: #endif /* AFS */
877:
878: /* Initialize the environment. */
879: envsize = 100;
880: env = xmalloc(envsize * sizeof(char *));
881: env[0] = NULL;
882:
883: if (!options.use_login) {
884: /* Set basic environment. */
885: child_set_env(&env, &envsize, "USER", pw->pw_name);
886: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
887: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 888: #ifdef HAVE_LOGIN_CAP
1.29 millert 889: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
890: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 891: #else
1.29 millert 892: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 893: #endif
1.1 markus 894:
895: snprintf(buf, sizeof buf, "%.200s/%.50s",
896: _PATH_MAILDIR, pw->pw_name);
897: child_set_env(&env, &envsize, "MAIL", buf);
898:
899: /* Normal systems set SHELL by default. */
900: child_set_env(&env, &envsize, "SHELL", shell);
901: }
902: if (getenv("TZ"))
903: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
904:
905: /* Set custom environment options from RSA authentication. */
906: while (custom_environment) {
907: struct envstring *ce = custom_environment;
908: char *s = ce->s;
909: int i;
910: for (i = 0; s[i] != '=' && s[i]; i++);
911: if (s[i] == '=') {
912: s[i] = 0;
913: child_set_env(&env, &envsize, s, s + i + 1);
914: }
915: custom_environment = ce->next;
916: xfree(ce->s);
917: xfree(ce);
918: }
919:
920: snprintf(buf, sizeof buf, "%.50s %d %d",
921: get_remote_ipaddr(), get_remote_port(), get_local_port());
922: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
923:
1.60 markus 924: if (s->ttyfd != -1)
925: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
926: if (s->term)
927: child_set_env(&env, &envsize, "TERM", s->term);
928: if (s->display)
929: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 930: if (original_command)
931: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
932: original_command);
1.1 markus 933:
934: #ifdef KRB4
935: {
936: extern char *ticket;
937:
938: if (ticket)
939: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
940: }
941: #endif /* KRB4 */
942:
943: if (xauthfile)
944: child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
945: if (auth_get_socket_name() != NULL)
946: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
947: auth_get_socket_name());
948:
949: /* read $HOME/.ssh/environment. */
950: if (!options.use_login) {
1.14 deraadt 951: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
952: pw->pw_dir);
1.1 markus 953: read_environment_file(&env, &envsize, buf);
954: }
955: if (debug_flag) {
956: /* dump the environment */
957: fprintf(stderr, "Environment:\n");
958: for (i = 0; env[i]; i++)
959: fprintf(stderr, " %.200s\n", env[i]);
960: }
1.26 millert 961: /* we have to stash the hostname before we close our socket. */
962: if (options.use_login)
963: hostname = get_remote_name_or_ip();
1.1 markus 964: /*
965: * Close the connection descriptors; note that this is the child, and
966: * the server will still have the socket open, and it is important
967: * that we do not shutdown it. Note that the descriptors cannot be
968: * closed before building the environment, as we call
969: * get_remote_ipaddr there.
970: */
971: if (packet_get_connection_in() == packet_get_connection_out())
972: close(packet_get_connection_in());
973: else {
974: close(packet_get_connection_in());
975: close(packet_get_connection_out());
976: }
977: /*
978: * Close all descriptors related to channels. They will still remain
979: * open in the parent.
980: */
981: /* XXX better use close-on-exec? -markus */
982: channel_close_all();
983:
984: /*
985: * Close any extra file descriptors. Note that there may still be
986: * descriptors left by system functions. They will be closed later.
987: */
988: endpwent();
989:
990: /*
991: * Close any extra open file descriptors so that we don\'t have them
992: * hanging around in clients. Note that we want to do this after
993: * initgroups, because at least on Solaris 2.3 it leaves file
994: * descriptors open.
995: */
996: for (i = 3; i < 64; i++)
997: close(i);
998:
999: /* Change current directory to the user\'s home directory. */
1.28 millert 1000: if (chdir(pw->pw_dir) < 0) {
1.1 markus 1001: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1002: pw->pw_dir, strerror(errno));
1.28 millert 1003: #ifdef HAVE_LOGIN_CAP
1004: if (login_getcapbool(lc, "requirehome", 0))
1005: exit(1);
1006: #endif
1007: }
1.1 markus 1008:
1009: /*
1010: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1011: * xauth are run in the proper environment.
1012: */
1013: environ = env;
1014:
1015: /*
1016: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1017: * in this order).
1018: */
1019: if (!options.use_login) {
1.50 markus 1020: if (stat(_PATH_SSH_USER_RC, &st) >= 0) {
1.1 markus 1021: if (debug_flag)
1.60 markus 1022: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1023: _PATH_SSH_USER_RC);
1.50 markus 1024: f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w");
1.1 markus 1025: if (f) {
1.60 markus 1026: if (do_xauth)
1027: fprintf(f, "%s %s\n", s->auth_proto,
1028: s->auth_data);
1.1 markus 1029: pclose(f);
1030: } else
1.60 markus 1031: fprintf(stderr, "Could not run %s\n",
1032: _PATH_SSH_USER_RC);
1.50 markus 1033: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 1034: if (debug_flag)
1.60 markus 1035: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1036: _PATH_SSH_SYSTEM_RC);
1.50 markus 1037: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 1038: if (f) {
1.60 markus 1039: if (do_xauth)
1040: fprintf(f, "%s %s\n", s->auth_proto,
1041: s->auth_data);
1.1 markus 1042: pclose(f);
1043: } else
1.60 markus 1044: fprintf(stderr, "Could not run %s\n",
1045: _PATH_SSH_SYSTEM_RC);
1046: } else if (do_xauth && options.xauth_location != NULL) {
1.1 markus 1047: /* Add authority data to .Xauthority if appropriate. */
1.60 markus 1048: char *screen = strchr(s->display, ':');
1049:
1050: if (debug_flag) {
1051: fprintf(stderr,
1052: "Running %.100s add "
1053: "%.100s %.100s %.100s\n",
1054: options.xauth_location, s->display,
1055: s->auth_proto, s->auth_data);
1056: if (screen != NULL)
1.14 deraadt 1057: fprintf(stderr,
1.60 markus 1058: "Adding %.*s/unix%s %s %s\n",
1059: (int)(screen - s->display),
1060: s->display, screen,
1061: s->auth_proto, s->auth_data);
1062: }
1063: snprintf(cmd, sizeof cmd, "%s -q -",
1064: options.xauth_location);
1065: f = popen(cmd, "w");
1066: if (f) {
1067: fprintf(f, "add %s %s %s\n", s->display,
1068: s->auth_proto, s->auth_data);
1069: if (screen != NULL)
1070: fprintf(f, "add %.*s/unix%s %s %s\n",
1071: (int)(screen - s->display),
1072: s->display, screen,
1073: s->auth_proto,
1074: s->auth_data);
1075: pclose(f);
1076: } else {
1077: fprintf(stderr, "Could not run %s\n",
1078: cmd);
1.1 markus 1079: }
1080: }
1081: /* Get the last component of the shell name. */
1082: cp = strrchr(shell, '/');
1083: if (cp)
1084: cp++;
1085: else
1086: cp = shell;
1087: }
1088: /*
1089: * If we have no command, execute the shell. In this case, the shell
1090: * name to be passed in argv[0] is preceded by '-' to indicate that
1091: * this is a login shell.
1092: */
1093: if (!command) {
1094: if (!options.use_login) {
1095: char buf[256];
1096:
1097: /*
1098: * Check for mail if we have a tty and it was enabled
1099: * in server options.
1100: */
1.60 markus 1101: if (s->ttyfd != -1 && options.check_mail) {
1.1 markus 1102: char *mailbox;
1103: struct stat mailstat;
1.60 markus 1104:
1.1 markus 1105: mailbox = getenv("MAIL");
1106: if (mailbox != NULL) {
1.14 deraadt 1107: if (stat(mailbox, &mailstat) != 0 ||
1108: mailstat.st_size == 0)
1.1 markus 1109: printf("No mail.\n");
1110: else if (mailstat.st_mtime < mailstat.st_atime)
1111: printf("You have mail.\n");
1112: else
1113: printf("You have new mail.\n");
1114: }
1115: }
1116: /* Start the shell. Set initial character to '-'. */
1117: buf[0] = '-';
1118: strncpy(buf + 1, cp, sizeof(buf) - 1);
1119: buf[sizeof(buf) - 1] = 0;
1120:
1121: /* Execute the shell. */
1122: argv[0] = buf;
1123: argv[1] = NULL;
1124: execve(shell, argv, env);
1125:
1126: /* Executing the shell failed. */
1127: perror(shell);
1128: exit(1);
1129:
1130: } else {
1131: /* Launch login(1). */
1132:
1.26 millert 1133: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1134: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1135:
1136: /* Login couldn't be executed, die. */
1137:
1138: perror("login");
1139: exit(1);
1140: }
1141: }
1142: /*
1143: * Execute the command using the user's shell. This uses the -c
1144: * option to execute the command.
1145: */
1146: argv[0] = (char *) cp;
1147: argv[1] = "-c";
1148: argv[2] = (char *) command;
1149: argv[3] = NULL;
1150: execve(shell, argv, env);
1151: perror(shell);
1152: exit(1);
1153: }
1154:
1155: Session *
1156: session_new(void)
1157: {
1158: int i;
1159: static int did_init = 0;
1160: if (!did_init) {
1161: debug("session_new: init");
1162: for(i = 0; i < MAX_SESSIONS; i++) {
1163: sessions[i].used = 0;
1164: sessions[i].self = i;
1165: }
1166: did_init = 1;
1167: }
1168: for(i = 0; i < MAX_SESSIONS; i++) {
1169: Session *s = &sessions[i];
1170: if (! s->used) {
1171: s->pid = 0;
1.7 markus 1172: s->extended = 0;
1.1 markus 1173: s->chanid = -1;
1174: s->ptyfd = -1;
1175: s->ttyfd = -1;
1176: s->term = NULL;
1177: s->pw = NULL;
1178: s->display = NULL;
1179: s->screen = 0;
1180: s->auth_data = NULL;
1181: s->auth_proto = NULL;
1182: s->used = 1;
1.7 markus 1183: s->pw = NULL;
1.1 markus 1184: debug("session_new: session %d", i);
1185: return s;
1186: }
1187: }
1188: return NULL;
1189: }
1190:
1191: void
1192: session_dump(void)
1193: {
1194: int i;
1195: for(i = 0; i < MAX_SESSIONS; i++) {
1196: Session *s = &sessions[i];
1197: debug("dump: used %d session %d %p channel %d pid %d",
1198: s->used,
1199: s->self,
1200: s,
1201: s->chanid,
1202: s->pid);
1203: }
1204: }
1205:
1.2 markus 1206: int
1207: session_open(int chanid)
1208: {
1209: Session *s = session_new();
1210: debug("session_open: channel %d", chanid);
1211: if (s == NULL) {
1212: error("no more sessions");
1213: return 0;
1214: }
1.7 markus 1215: s->pw = auth_get_user();
1216: if (s->pw == NULL)
1.54 stevesk 1217: fatal("no user for session %d", s->self);
1.2 markus 1218: debug("session_open: session %d: link with channel %d", s->self, chanid);
1219: s->chanid = chanid;
1220: return 1;
1221: }
1222:
1223: Session *
1224: session_by_channel(int id)
1225: {
1226: int i;
1227: for(i = 0; i < MAX_SESSIONS; i++) {
1228: Session *s = &sessions[i];
1229: if (s->used && s->chanid == id) {
1230: debug("session_by_channel: session %d channel %d", i, id);
1231: return s;
1232: }
1233: }
1234: debug("session_by_channel: unknown channel %d", id);
1235: session_dump();
1236: return NULL;
1237: }
1238:
1239: Session *
1240: session_by_pid(pid_t pid)
1241: {
1242: int i;
1243: debug("session_by_pid: pid %d", pid);
1244: for(i = 0; i < MAX_SESSIONS; i++) {
1245: Session *s = &sessions[i];
1246: if (s->used && s->pid == pid)
1247: return s;
1248: }
1249: error("session_by_pid: unknown pid %d", pid);
1250: session_dump();
1251: return NULL;
1252: }
1253:
1254: int
1255: session_window_change_req(Session *s)
1256: {
1257: s->col = packet_get_int();
1258: s->row = packet_get_int();
1259: s->xpixel = packet_get_int();
1260: s->ypixel = packet_get_int();
1.3 markus 1261: packet_done();
1.2 markus 1262: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1263: return 1;
1264: }
1265:
1266: int
1267: session_pty_req(Session *s)
1268: {
1.45 markus 1269: u_int len;
1.3 markus 1270: char *term_modes; /* encoded terminal modes */
1.2 markus 1271:
1.19 markus 1272: if (no_pty_flag)
1273: return 0;
1.2 markus 1274: if (s->ttyfd != -1)
1.3 markus 1275: return 0;
1.2 markus 1276: s->term = packet_get_string(&len);
1277: s->col = packet_get_int();
1278: s->row = packet_get_int();
1279: s->xpixel = packet_get_int();
1280: s->ypixel = packet_get_int();
1.3 markus 1281: term_modes = packet_get_string(&len);
1282: packet_done();
1.2 markus 1283:
1284: if (strcmp(s->term, "") == 0) {
1285: xfree(s->term);
1286: s->term = NULL;
1287: }
1288: /* Allocate a pty and open it. */
1289: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1290: xfree(s->term);
1291: s->term = NULL;
1292: s->ptyfd = -1;
1293: s->ttyfd = -1;
1294: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1295: xfree(term_modes);
1296: return 0;
1.2 markus 1297: }
1298: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1299: /*
1300: * Add a cleanup function to clear the utmp entry and record logout
1301: * time in case we call fatal() (e.g., the connection gets closed).
1302: */
1303: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1304: pty_setowner(s->pw, s->tty);
1305: /* Get window size from the packet. */
1306: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1307:
1.9 markus 1308: session_proctitle(s);
1309:
1.3 markus 1310: /* XXX parse and set terminal modes */
1311: xfree(term_modes);
1.2 markus 1312: return 1;
1313: }
1314:
1.7 markus 1315: int
1316: session_subsystem_req(Session *s)
1317: {
1.45 markus 1318: u_int len;
1.7 markus 1319: int success = 0;
1320: char *subsys = packet_get_string(&len);
1.18 jakob 1321: int i;
1.7 markus 1322:
1323: packet_done();
1324: log("subsystem request for %s", subsys);
1.18 jakob 1325:
1326: for (i = 0; i < options.num_subsystems; i++) {
1327: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1328: debug("subsystem: exec() %s", options.subsystem_command[i]);
1329: do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1330: success = 1;
1331: }
1332: }
1333:
1334: if (!success)
1335: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1336:
1337: xfree(subsys);
1338: return success;
1339: }
1340:
1341: int
1342: session_x11_req(Session *s)
1343: {
1.33 markus 1344: int fd;
1.22 deraadt 1345: if (no_x11_forwarding_flag) {
1.19 markus 1346: debug("X11 forwarding disabled in user configuration file.");
1347: return 0;
1348: }
1.7 markus 1349: if (!options.x11_forwarding) {
1350: debug("X11 forwarding disabled in server configuration file.");
1351: return 0;
1352: }
1353: if (xauthfile != NULL) {
1354: debug("X11 fwd already started.");
1355: return 0;
1356: }
1357:
1358: debug("Received request for X11 forwarding with auth spoofing.");
1359: if (s->display != NULL)
1360: packet_disconnect("Protocol error: X11 display already set.");
1361:
1362: s->single_connection = packet_get_char();
1363: s->auth_proto = packet_get_string(NULL);
1364: s->auth_data = packet_get_string(NULL);
1365: s->screen = packet_get_int();
1366: packet_done();
1367:
1368: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1369: if (s->display == NULL) {
1370: xfree(s->auth_proto);
1371: xfree(s->auth_data);
1372: return 0;
1373: }
1374: xauthfile = xmalloc(MAXPATHLEN);
1375: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1376: temporarily_use_uid(s->pw->pw_uid);
1377: if (mkdtemp(xauthfile) == NULL) {
1378: restore_uid();
1379: error("private X11 dir: mkdtemp %s failed: %s",
1380: xauthfile, strerror(errno));
1381: xfree(xauthfile);
1382: xauthfile = NULL;
1383: xfree(s->auth_proto);
1384: xfree(s->auth_data);
1385: /* XXXX remove listening channels */
1386: return 0;
1387: }
1388: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 1389: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1390: if (fd >= 0)
1391: close(fd);
1.7 markus 1392: restore_uid();
1393: fatal_add_cleanup(xauthfile_cleanup_proc, s);
1394: return 1;
1395: }
1396:
1.19 markus 1397: int
1398: session_shell_req(Session *s)
1399: {
1400: /* if forced_command == NULL, the shell is execed */
1401: char *shell = forced_command;
1402: packet_done();
1403: s->extended = 1;
1404: if (s->ttyfd == -1)
1405: do_exec_no_pty(s, shell, s->pw);
1406: else
1407: do_exec_pty(s, shell, s->pw);
1408: return 1;
1409: }
1410:
1411: int
1412: session_exec_req(Session *s)
1413: {
1.45 markus 1414: u_int len;
1.19 markus 1415: char *command = packet_get_string(&len);
1416: packet_done();
1417: if (forced_command) {
1.34 markus 1418: original_command = command;
1.19 markus 1419: command = forced_command;
1420: debug("Forced command '%.500s'", forced_command);
1421: }
1422: s->extended = 1;
1423: if (s->ttyfd == -1)
1424: do_exec_no_pty(s, command, s->pw);
1425: else
1426: do_exec_pty(s, command, s->pw);
1427: if (forced_command == NULL)
1428: xfree(command);
1429: return 1;
1430: }
1431:
1.43 markus 1432: int
1433: session_auth_agent_req(Session *s)
1434: {
1435: static int called = 0;
1436: packet_done();
1.44 markus 1437: if (no_agent_forwarding_flag) {
1438: debug("session_auth_agent_req: no_agent_forwarding_flag");
1439: return 0;
1440: }
1.43 markus 1441: if (called) {
1442: return 0;
1443: } else {
1444: called = 1;
1445: return auth_input_request_forwarding(s->pw);
1446: }
1447: }
1448:
1.2 markus 1449: void
1450: session_input_channel_req(int id, void *arg)
1451: {
1.45 markus 1452: u_int len;
1.2 markus 1453: int reply;
1454: int success = 0;
1455: char *rtype;
1456: Session *s;
1457: Channel *c;
1458:
1459: rtype = packet_get_string(&len);
1460: reply = packet_get_char();
1461:
1462: s = session_by_channel(id);
1463: if (s == NULL)
1464: fatal("session_input_channel_req: channel %d: no session", id);
1465: c = channel_lookup(id);
1466: if (c == NULL)
1467: fatal("session_input_channel_req: channel %d: bad channel", id);
1468:
1469: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1470: s->self, id, rtype, reply);
1471:
1472: /*
1473: * a session is in LARVAL state until a shell
1474: * or programm is executed
1475: */
1476: if (c->type == SSH_CHANNEL_LARVAL) {
1477: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1478: success = session_shell_req(s);
1.2 markus 1479: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1480: success = session_exec_req(s);
1.2 markus 1481: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1482: success = session_pty_req(s);
1.7 markus 1483: } else if (strcmp(rtype, "x11-req") == 0) {
1484: success = session_x11_req(s);
1.43 markus 1485: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1486: success = session_auth_agent_req(s);
1.7 markus 1487: } else if (strcmp(rtype, "subsystem") == 0) {
1488: success = session_subsystem_req(s);
1.2 markus 1489: }
1490: }
1491: if (strcmp(rtype, "window-change") == 0) {
1492: success = session_window_change_req(s);
1493: }
1494:
1495: if (reply) {
1496: packet_start(success ?
1497: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1498: packet_put_int(c->remote_id);
1499: packet_send();
1500: }
1501: xfree(rtype);
1502: }
1503:
1504: void
1505: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1506: {
1507: if (!compat20)
1508: fatal("session_set_fds: called for proto != 2.0");
1509: /*
1510: * now that have a child and a pipe to the child,
1511: * we can activate our channel and register the fd's
1512: */
1513: if (s->chanid == -1)
1514: fatal("no channel for session %d", s->self);
1515: channel_set_fds(s->chanid,
1516: fdout, fdin, fderr,
1.42 markus 1517: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1518: 1);
1.2 markus 1519: }
1520:
1.1 markus 1521: void
1522: session_pty_cleanup(Session *s)
1523: {
1524: if (s == NULL || s->ttyfd == -1)
1525: return;
1526:
1.54 stevesk 1527: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1528:
1529: /* Cancel the cleanup function. */
1530: fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1531:
1532: /* Record that the user has logged out. */
1533: record_logout(s->pid, s->tty);
1534:
1535: /* Release the pseudo-tty. */
1536: pty_release(s->tty);
1537:
1538: /*
1539: * Close the server side of the socket pairs. We must do this after
1540: * the pty cleanup, so that another process doesn't get this pty
1541: * while we're still cleaning up.
1542: */
1543: if (close(s->ptymaster) < 0)
1544: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1545: }
1546:
1547: void
1548: session_exit_message(Session *s, int status)
1549: {
1550: Channel *c;
1551: if (s == NULL)
1552: fatal("session_close: no session");
1553: c = channel_lookup(s->chanid);
1554: if (c == NULL)
1555: fatal("session_close: session %d: no channel %d",
1556: s->self, s->chanid);
1557: debug("session_exit_message: session %d channel %d pid %d",
1558: s->self, s->chanid, s->pid);
1559:
1560: if (WIFEXITED(status)) {
1561: channel_request_start(s->chanid,
1562: "exit-status", 0);
1563: packet_put_int(WEXITSTATUS(status));
1564: packet_send();
1565: } else if (WIFSIGNALED(status)) {
1566: channel_request_start(s->chanid,
1567: "exit-signal", 0);
1568: packet_put_int(WTERMSIG(status));
1569: packet_put_char(WCOREDUMP(status));
1570: packet_put_cstring("");
1571: packet_put_cstring("");
1572: packet_send();
1573: } else {
1574: /* Some weird exit cause. Just exit. */
1575: packet_disconnect("wait returned status %04x.", status);
1576: }
1577:
1578: /* disconnect channel */
1579: debug("session_exit_message: release channel %d", s->chanid);
1580: channel_cancel_cleanup(s->chanid);
1.5 markus 1581: /*
1582: * emulate a write failure with 'chan_write_failed', nobody will be
1583: * interested in data we write.
1584: * Note that we must not call 'chan_read_failed', since there could
1585: * be some more data waiting in the pipe.
1586: */
1.8 markus 1587: if (c->ostate != CHAN_OUTPUT_CLOSED)
1588: chan_write_failed(c);
1.2 markus 1589: s->chanid = -1;
1590: }
1591:
1592: void
1593: session_free(Session *s)
1594: {
1595: debug("session_free: session %d pid %d", s->self, s->pid);
1596: if (s->term)
1597: xfree(s->term);
1598: if (s->display)
1599: xfree(s->display);
1600: if (s->auth_data)
1601: xfree(s->auth_data);
1602: if (s->auth_proto)
1603: xfree(s->auth_proto);
1604: s->used = 0;
1605: }
1606:
1607: void
1608: session_close(Session *s)
1609: {
1610: session_pty_cleanup(s);
1611: session_free(s);
1.9 markus 1612: session_proctitle(s);
1.2 markus 1613: }
1614:
1615: void
1616: session_close_by_pid(pid_t pid, int status)
1617: {
1618: Session *s = session_by_pid(pid);
1619: if (s == NULL) {
1620: debug("session_close_by_pid: no session for pid %d", s->pid);
1621: return;
1622: }
1623: if (s->chanid != -1)
1624: session_exit_message(s, status);
1625: session_close(s);
1626: }
1627:
1628: /*
1629: * this is called when a channel dies before
1630: * the session 'child' itself dies
1631: */
1632: void
1633: session_close_by_channel(int id, void *arg)
1634: {
1635: Session *s = session_by_channel(id);
1636: if (s == NULL) {
1637: debug("session_close_by_channel: no session for channel %d", id);
1638: return;
1639: }
1640: /* disconnect channel */
1641: channel_cancel_cleanup(s->chanid);
1642: s->chanid = -1;
1643:
1644: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1645: if (s->pid == 0) {
1646: /* close session immediately */
1647: session_close(s);
1648: } else {
1649: /* notify child, delay session cleanup */
1650: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1651: error("session_close_by_channel: kill %d: %s",
1652: s->pid, strerror(errno));
1653: }
1.9 markus 1654: }
1655:
1656: char *
1657: session_tty_list(void)
1658: {
1659: static char buf[1024];
1660: int i;
1661: buf[0] = '\0';
1662: for(i = 0; i < MAX_SESSIONS; i++) {
1663: Session *s = &sessions[i];
1664: if (s->used && s->ttyfd != -1) {
1665: if (buf[0] != '\0')
1666: strlcat(buf, ",", sizeof buf);
1667: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1668: }
1669: }
1670: if (buf[0] == '\0')
1671: strlcpy(buf, "notty", sizeof buf);
1672: return buf;
1673: }
1674:
1675: void
1676: session_proctitle(Session *s)
1677: {
1678: if (s->pw == NULL)
1679: error("no user for session %d", s->self);
1680: else
1681: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1682: }
1683:
1684: void
1.49 markus 1685: do_authenticated2(Authctxt *authctxt)
1.2 markus 1686: {
1687: /*
1688: * Cancel the alarm we set to limit the time taken for
1689: * authentication.
1690: */
1691: alarm(0);
1.23 deraadt 1692: if (startup_pipe != -1) {
1693: close(startup_pipe);
1694: startup_pipe = -1;
1695: }
1.61 ! markus 1696: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
! 1697: channel_permit_all_opens();
1.28 millert 1698: #ifdef HAVE_LOGIN_CAP
1.49 markus 1699: if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
1.28 millert 1700: error("unable to get login class");
1701: return;
1702: }
1703: #endif
1.2 markus 1704: server_loop2();
1.7 markus 1705: if (xauthfile)
1706: xauthfile_cleanup_proc(NULL);
1.1 markus 1707: }
![[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