Annotation of src/usr.bin/ssh/session.c, Revision 1.79
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"
1.79 ! markus 36: RCSID("$OpenBSD: session.c,v 1.78 2001/05/31 10:30:16 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"
1.78 markus 48: #include "channels.h"
1.2 markus 49: #include "bufaux.h"
50: #include "auth.h"
1.19 markus 51: #include "auth-options.h"
1.50 markus 52: #include "pathnames.h"
1.51 markus 53: #include "log.h"
54: #include "servconf.h"
1.59 djm 55: #include "sshlogin.h"
1.51 markus 56: #include "serverloop.h"
57: #include "canohost.h"
1.55 itojun 58: #include "session.h"
1.2 markus 59:
1.1 markus 60: /* types */
61:
62: #define TTYSZ 64
63: typedef struct Session Session;
64: struct Session {
65: int used;
66: int self;
67: struct passwd *pw;
68: pid_t pid;
69: /* tty */
70: char *term;
71: int ptyfd, ttyfd, ptymaster;
72: int row, col, xpixel, ypixel;
73: char tty[TTYSZ];
74: /* X11 */
75: char *display;
76: int screen;
77: char *auth_proto;
78: char *auth_data;
1.7 markus 79: int single_connection;
1.1 markus 80: /* proto 2 */
81: int chanid;
1.64 markus 82: int is_subsystem;
1.1 markus 83: };
84:
85: /* func */
86:
87: Session *session_new(void);
88: void session_set_fds(Session *s, int fdin, int fdout, int fderr);
89: void session_pty_cleanup(Session *s);
1.9 markus 90: void session_proctitle(Session *s);
1.63 markus 91: void do_exec_pty(Session *s, const char *command);
92: void do_exec_no_pty(Session *s, const char *command);
1.41 markus 93: void do_login(Session *s, const char *command);
1.60 markus 94: void do_child(Session *s, const char *command);
1.73 djm 95: void do_motd(void);
96: int check_quietlogin(Session *s, const char *command);
1.79 ! markus 97: void xauthfile_cleanup_proc(void *ignore);
1.1 markus 98:
1.65 markus 99: void do_authenticated1(Authctxt *authctxt);
100: void do_authenticated2(Authctxt *authctxt);
101:
1.1 markus 102: /* import */
103: extern ServerOptions options;
104: extern char *__progname;
105: extern int log_stderr;
106: extern int debug_flag;
1.45 markus 107: extern u_int utmp_len;
1.21 markus 108: extern int startup_pipe;
1.74 markus 109: extern void destroy_sensitive_data(void);
1.21 markus 110:
1.1 markus 111: /* Local Xauthority file. */
112: static char *xauthfile;
113:
1.34 markus 114: /* original command from peer. */
1.53 stevesk 115: char *original_command = NULL;
1.34 markus 116:
1.1 markus 117: /* data */
118: #define MAX_SESSIONS 10
119: Session sessions[MAX_SESSIONS];
120:
1.28 millert 121: #ifdef HAVE_LOGIN_CAP
122: static login_cap_t *lc;
123: #endif
124:
1.65 markus 125: void
126: do_authenticated(Authctxt *authctxt)
127: {
128: /*
129: * Cancel the alarm we set to limit the time taken for
130: * authentication.
131: */
132: alarm(0);
133: if (startup_pipe != -1) {
134: close(startup_pipe);
135: startup_pipe = -1;
136: }
137: #ifdef HAVE_LOGIN_CAP
138: if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
139: error("unable to get login class");
140: return;
141: }
1.74 markus 142: #ifdef BSD_AUTH
143: if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
144: packet_disconnect("Approval failure for %s",
145: authctxt->pw->pw_name);
146: }
147: #endif
1.65 markus 148: #endif
149: /* setup the channel layer */
150: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
151: channel_permit_all_opens();
152:
153: if (compat20)
154: do_authenticated2(authctxt);
155: else
156: do_authenticated1(authctxt);
1.79 ! markus 157:
! 158: /* remote user's local Xauthority file and agent socket */
! 159: if (xauthfile)
! 160: xauthfile_cleanup_proc(NULL);
! 161: if (auth_get_socket_name())
! 162: auth_sock_cleanup_proc(NULL);
1.65 markus 163: }
164:
1.1 markus 165: /*
166: * Remove local Xauthority file.
167: */
168: void
169: xauthfile_cleanup_proc(void *ignore)
170: {
171: debug("xauthfile_cleanup_proc called");
172:
173: if (xauthfile != NULL) {
174: char *p;
175: unlink(xauthfile);
176: p = strrchr(xauthfile, '/');
177: if (p != NULL) {
178: *p = '\0';
179: rmdir(xauthfile);
180: }
181: xfree(xauthfile);
182: xauthfile = NULL;
183: }
184: }
185:
186: /*
187: * Function to perform cleanup if we get aborted abnormally (e.g., due to a
188: * dropped connection).
189: */
1.4 markus 190: void
1.1 markus 191: pty_cleanup_proc(void *session)
192: {
193: Session *s=session;
194: if (s == NULL)
195: fatal("pty_cleanup_proc: no session");
196: debug("pty_cleanup_proc: %s", s->tty);
197:
198: if (s->pid != 0) {
199: /* Record that the user has logged out. */
200: record_logout(s->pid, s->tty);
201: }
202:
203: /* Release the pseudo-tty. */
204: pty_release(s->tty);
205: }
206:
207: /*
208: * Prepares for an interactive session. This is called after the user has
209: * been successfully authenticated. During this message exchange, pseudo
210: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
211: * are requested, etc.
212: */
1.4 markus 213: void
1.65 markus 214: do_authenticated1(Authctxt *authctxt)
1.1 markus 215: {
216: Session *s;
1.65 markus 217: char *command;
218: int success, type, fd, n_bytes, plen, screen_flag, have_pty = 0;
1.1 markus 219: int compression_level = 0, enable_compression_after_reply = 0;
1.45 markus 220: u_int proto_len, data_len, dlen;
1.76 djm 221: struct stat st;
1.1 markus 222:
1.61 markus 223: s = session_new();
1.65 markus 224: s->pw = authctxt->pw;
1.28 millert 225:
1.1 markus 226: /*
227: * We stay in this loop until the client requests to execute a shell
228: * or a command.
229: */
230: for (;;) {
1.65 markus 231: success = 0;
1.1 markus 232:
233: /* Get a packet from the client. */
234: type = packet_read(&plen);
235:
236: /* Process the packet. */
237: switch (type) {
238: case SSH_CMSG_REQUEST_COMPRESSION:
239: packet_integrity_check(plen, 4, type);
240: compression_level = packet_get_int();
241: if (compression_level < 1 || compression_level > 9) {
242: packet_send_debug("Received illegal compression level %d.",
243: compression_level);
244: break;
245: }
246: /* Enable compression after we have responded with SUCCESS. */
247: enable_compression_after_reply = 1;
248: success = 1;
249: break;
250:
251: case SSH_CMSG_REQUEST_PTY:
252: if (no_pty_flag) {
253: debug("Allocating a pty not permitted for this authentication.");
254: break;
255: }
256: if (have_pty)
257: packet_disconnect("Protocol error: you already have a pty.");
258:
259: debug("Allocating pty.");
260:
261: /* Allocate a pty and open it. */
262: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
263: sizeof(s->tty))) {
264: error("Failed to allocate pty.");
265: break;
266: }
267: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1.65 markus 268: pty_setowner(s->pw, s->tty);
1.1 markus 269:
270: /* Get TERM from the packet. Note that the value may be of arbitrary length. */
271: s->term = packet_get_string(&dlen);
272: packet_integrity_check(dlen, strlen(s->term), type);
273: /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
274: /* Remaining bytes */
275: n_bytes = plen - (4 + dlen + 4 * 4);
276:
277: if (strcmp(s->term, "") == 0) {
278: xfree(s->term);
279: s->term = NULL;
280: }
281: /* Get window size from the packet. */
282: s->row = packet_get_int();
283: s->col = packet_get_int();
284: s->xpixel = packet_get_int();
285: s->ypixel = packet_get_int();
286: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
287:
288: /* Get tty modes from the packet. */
289: tty_parse_modes(s->ttyfd, &n_bytes);
290: packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
1.10 markus 291:
292: session_proctitle(s);
1.1 markus 293:
294: /* Indicate that we now have a pty. */
295: success = 1;
296: have_pty = 1;
297: break;
298:
299: case SSH_CMSG_X11_REQUEST_FORWARDING:
300: if (!options.x11_forwarding) {
301: packet_send_debug("X11 forwarding disabled in server configuration file.");
302: break;
303: }
1.76 djm 304: if (!options.xauth_location ||
305: (stat(options.xauth_location, &st) == -1)) {
1.16 markus 306: packet_send_debug("No xauth program; cannot forward with spoofing.");
307: break;
308: }
1.1 markus 309: if (no_x11_forwarding_flag) {
310: packet_send_debug("X11 forwarding not permitted for this authentication.");
311: break;
312: }
313: debug("Received request for X11 forwarding with auth spoofing.");
314: if (s->display != NULL)
315: packet_disconnect("Protocol error: X11 display already set.");
316:
317: s->auth_proto = packet_get_string(&proto_len);
318: s->auth_data = packet_get_string(&data_len);
319:
1.57 markus 320: screen_flag = packet_get_protocol_flags() &
321: SSH_PROTOFLAG_SCREEN_NUMBER;
322: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
323:
324: if (packet_remaining() == 4) {
325: if (!screen_flag)
326: debug2("Buggy client: "
327: "X11 screen flag missing");
1.56 markus 328: packet_integrity_check(plen,
329: 4 + proto_len + 4 + data_len + 4, type);
1.1 markus 330: s->screen = packet_get_int();
1.56 markus 331: } else {
332: packet_integrity_check(plen,
333: 4 + proto_len + 4 + data_len, type);
1.1 markus 334: s->screen = 0;
1.56 markus 335: }
1.1 markus 336: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
337:
338: if (s->display == NULL)
339: break;
340:
341: /* Setup to always have a local .Xauthority. */
342: xauthfile = xmalloc(MAXPATHLEN);
343: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.71 markus 344: temporarily_use_uid(s->pw);
1.1 markus 345: if (mkdtemp(xauthfile) == NULL) {
346: restore_uid();
347: error("private X11 dir: mkdtemp %s failed: %s",
348: xauthfile, strerror(errno));
349: xfree(xauthfile);
350: xauthfile = NULL;
1.7 markus 351: /* XXXX remove listening channels */
1.1 markus 352: break;
353: }
354: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 355: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
356: if (fd >= 0)
357: close(fd);
1.1 markus 358: restore_uid();
359: fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
360: success = 1;
361: break;
362:
363: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
364: if (no_agent_forwarding_flag || compat13) {
365: debug("Authentication agent forwarding not permitted for this authentication.");
366: break;
367: }
368: debug("Received authentication agent forwarding request.");
1.65 markus 369: success = auth_input_request_forwarding(s->pw);
1.1 markus 370: break;
371:
372: case SSH_CMSG_PORT_FORWARD_REQUEST:
373: if (no_port_forwarding_flag) {
374: debug("Port forwarding not permitted for this authentication.");
1.39 markus 375: break;
376: }
377: if (!options.allow_tcp_forwarding) {
378: debug("Port forwarding not permitted.");
1.1 markus 379: break;
380: }
381: debug("Received TCP/IP port forwarding request.");
1.65 markus 382: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 383: success = 1;
384: break;
385:
386: case SSH_CMSG_MAX_PACKET_SIZE:
387: if (packet_set_maxsize(packet_get_int()) > 0)
388: success = 1;
389: break;
390:
391: case SSH_CMSG_EXEC_SHELL:
392: case SSH_CMSG_EXEC_CMD:
393: if (type == SSH_CMSG_EXEC_CMD) {
394: command = packet_get_string(&dlen);
395: debug("Exec command '%.500s'", command);
396: packet_integrity_check(plen, 4 + dlen, type);
397: } else {
398: command = NULL;
399: packet_integrity_check(plen, 0, type);
400: }
401: if (forced_command != NULL) {
1.34 markus 402: original_command = command;
1.1 markus 403: command = forced_command;
404: debug("Forced command '%.500s'", forced_command);
405: }
406: if (have_pty)
1.63 markus 407: do_exec_pty(s, command);
1.1 markus 408: else
1.63 markus 409: do_exec_no_pty(s, command);
1.1 markus 410:
411: if (command != NULL)
412: xfree(command);
413: return;
414:
415: default:
416: /*
417: * Any unknown messages in this phase are ignored,
418: * and a failure message is returned.
419: */
420: log("Unknown packet type received after authentication: %d", type);
421: }
422: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
423: packet_send();
424: packet_write_wait();
425:
426: /* Enable compression now that we have replied if appropriate. */
427: if (enable_compression_after_reply) {
428: enable_compression_after_reply = 0;
429: packet_start_compression(compression_level);
430: }
431: }
432: }
433:
434: /*
435: * This is called to fork and execute a command when we have no tty. This
436: * will call do_child from the child, and server_loop from the parent after
437: * setting up file descriptors and such.
438: */
1.4 markus 439: void
1.63 markus 440: do_exec_no_pty(Session *s, const char *command)
1.1 markus 441: {
442: int pid;
443:
444: #ifdef USE_PIPES
445: int pin[2], pout[2], perr[2];
446: /* Allocate pipes for communicating with the program. */
447: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
448: packet_disconnect("Could not create pipes: %.100s",
449: strerror(errno));
450: #else /* USE_PIPES */
451: int inout[2], err[2];
452: /* Uses socket pairs to communicate with the program. */
453: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
454: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
455: packet_disconnect("Could not create socket pairs: %.100s",
456: strerror(errno));
457: #endif /* USE_PIPES */
458: if (s == NULL)
459: fatal("do_exec_no_pty: no session");
460:
1.9 markus 461: session_proctitle(s);
1.1 markus 462:
463: /* Fork the child. */
464: if ((pid = fork()) == 0) {
465: /* Child. Reinitialize the log since the pid has changed. */
466: log_init(__progname, options.log_level, options.log_facility, log_stderr);
467:
468: /*
469: * Create a new session and process group since the 4.4BSD
470: * setlogin() affects the entire process group.
471: */
472: if (setsid() < 0)
473: error("setsid failed: %.100s", strerror(errno));
474:
475: #ifdef USE_PIPES
476: /*
477: * Redirect stdin. We close the parent side of the socket
478: * pair, and make the child side the standard input.
479: */
480: close(pin[1]);
481: if (dup2(pin[0], 0) < 0)
482: perror("dup2 stdin");
483: close(pin[0]);
484:
485: /* Redirect stdout. */
486: close(pout[0]);
487: if (dup2(pout[1], 1) < 0)
488: perror("dup2 stdout");
489: close(pout[1]);
490:
491: /* Redirect stderr. */
492: close(perr[0]);
493: if (dup2(perr[1], 2) < 0)
494: perror("dup2 stderr");
495: close(perr[1]);
496: #else /* USE_PIPES */
497: /*
498: * Redirect stdin, stdout, and stderr. Stdin and stdout will
499: * use the same socket, as some programs (particularly rdist)
500: * seem to depend on it.
501: */
502: close(inout[1]);
503: close(err[1]);
504: if (dup2(inout[0], 0) < 0) /* stdin */
505: perror("dup2 stdin");
506: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
507: perror("dup2 stdout");
508: if (dup2(err[0], 2) < 0) /* stderr */
509: perror("dup2 stderr");
510: #endif /* USE_PIPES */
511:
512: /* Do processing for the child (exec command etc). */
1.60 markus 513: do_child(s, command);
1.1 markus 514: /* NOTREACHED */
515: }
516: if (pid < 0)
517: packet_disconnect("fork failed: %.100s", strerror(errno));
518: s->pid = pid;
1.47 markus 519: /* Set interactive/non-interactive mode. */
1.48 markus 520: packet_set_interactive(s->display != NULL);
1.1 markus 521: #ifdef USE_PIPES
522: /* We are the parent. Close the child sides of the pipes. */
523: close(pin[0]);
524: close(pout[1]);
525: close(perr[1]);
526:
1.2 markus 527: if (compat20) {
1.64 markus 528: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 529: } else {
530: /* Enter the interactive session. */
531: server_loop(pid, pin[1], pout[0], perr[0]);
1.64 markus 532: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 533: }
1.1 markus 534: #else /* USE_PIPES */
535: /* We are the parent. Close the child sides of the socket pairs. */
536: close(inout[0]);
537: close(err[0]);
538:
539: /*
540: * Enter the interactive session. Note: server_loop must be able to
541: * handle the case that fdin and fdout are the same.
542: */
1.2 markus 543: if (compat20) {
1.64 markus 544: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 545: } else {
546: server_loop(pid, inout[1], inout[1], err[1]);
547: /* server_loop has closed inout[1] and err[1]. */
548: }
1.1 markus 549: #endif /* USE_PIPES */
550: }
551:
552: /*
553: * This is called to fork and execute a command when we have a tty. This
554: * will call do_child from the child, and server_loop from the parent after
555: * setting up file descriptors, controlling tty, updating wtmp, utmp,
556: * lastlog, and other such operations.
557: */
1.4 markus 558: void
1.63 markus 559: do_exec_pty(Session *s, const char *command)
1.1 markus 560: {
561: int fdout, ptyfd, ttyfd, ptymaster;
562: pid_t pid;
563:
564: if (s == NULL)
565: fatal("do_exec_pty: no session");
566: ptyfd = s->ptyfd;
567: ttyfd = s->ttyfd;
568:
569: /* Fork the child. */
570: if ((pid = fork()) == 0) {
1.24 markus 571: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 572: log_init(__progname, options.log_level, options.log_facility, log_stderr);
573:
574: /* Close the master side of the pseudo tty. */
575: close(ptyfd);
576:
577: /* Make the pseudo tty our controlling tty. */
578: pty_make_controlling_tty(&ttyfd, s->tty);
579:
580: /* Redirect stdin from the pseudo tty. */
581: if (dup2(ttyfd, fileno(stdin)) < 0)
582: error("dup2 stdin failed: %.100s", strerror(errno));
583:
584: /* Redirect stdout to the pseudo tty. */
585: if (dup2(ttyfd, fileno(stdout)) < 0)
586: error("dup2 stdin failed: %.100s", strerror(errno));
587:
588: /* Redirect stderr to the pseudo tty. */
589: if (dup2(ttyfd, fileno(stderr)) < 0)
590: error("dup2 stdin failed: %.100s", strerror(errno));
591:
592: /* Close the extra descriptor for the pseudo tty. */
593: close(ttyfd);
594:
1.24 markus 595: /* record login, etc. similar to login(1) */
1.41 markus 596: if (!(options.use_login && command == NULL))
597: do_login(s, command);
1.1 markus 598:
599: /* Do common processing for the child, such as execing the command. */
1.60 markus 600: do_child(s, command);
1.1 markus 601: /* NOTREACHED */
602: }
603: if (pid < 0)
604: packet_disconnect("fork failed: %.100s", strerror(errno));
605: s->pid = pid;
606:
607: /* Parent. Close the slave side of the pseudo tty. */
608: close(ttyfd);
609:
610: /*
611: * Create another descriptor of the pty master side for use as the
612: * standard input. We could use the original descriptor, but this
613: * simplifies code in server_loop. The descriptor is bidirectional.
614: */
615: fdout = dup(ptyfd);
616: if (fdout < 0)
617: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
618:
619: /* we keep a reference to the pty master */
620: ptymaster = dup(ptyfd);
621: if (ptymaster < 0)
622: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
623: s->ptymaster = ptymaster;
624:
625: /* Enter interactive session. */
1.47 markus 626: packet_set_interactive(1);
1.2 markus 627: if (compat20) {
628: session_set_fds(s, ptyfd, fdout, -1);
629: } else {
630: server_loop(pid, ptyfd, fdout, -1);
631: /* server_loop _has_ closed ptyfd and fdout. */
632: session_pty_cleanup(s);
1.24 markus 633: }
634: }
635:
636: /* administrative, login(1)-like work */
637: void
1.41 markus 638: do_login(Session *s, const char *command)
1.24 markus 639: {
640: char *time_string;
1.35 markus 641: char hostname[MAXHOSTNAMELEN];
1.24 markus 642: socklen_t fromlen;
643: struct sockaddr_storage from;
644: time_t last_login_time;
645: struct passwd * pw = s->pw;
646: pid_t pid = getpid();
647:
648: /*
649: * Get IP address of client. If the connection is not a socket, let
650: * the address be 0.0.0.0.
651: */
652: memset(&from, 0, sizeof(from));
653: if (packet_connection_is_on_socket()) {
654: fromlen = sizeof(from);
655: if (getpeername(packet_get_connection_in(),
656: (struct sockaddr *) & from, &fromlen) < 0) {
657: debug("getpeername: %.100s", strerror(errno));
658: fatal_cleanup();
659: }
660: }
1.25 markus 661:
1.35 markus 662: /* Get the time and hostname when the user last logged in. */
1.69 stevesk 663: if (options.print_lastlog) {
664: hostname[0] = '\0';
665: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
666: hostname, sizeof(hostname));
667: }
1.35 markus 668:
1.24 markus 669: /* Record that there was a login on that tty from the remote host. */
670: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.70 stevesk 671: get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
672: (struct sockaddr *)&from);
1.24 markus 673:
1.73 djm 674: if (check_quietlogin(s, command))
1.24 markus 675: return;
1.73 djm 676:
1.69 stevesk 677: if (options.print_lastlog && last_login_time != 0) {
1.24 markus 678: time_string = ctime(&last_login_time);
679: if (strchr(time_string, '\n'))
680: *strchr(time_string, '\n') = 0;
1.40 markus 681: if (strcmp(hostname, "") == 0)
1.24 markus 682: printf("Last login: %s\r\n", time_string);
683: else
1.36 markus 684: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 685: }
1.73 djm 686:
687: do_motd();
688: }
689:
690: /*
691: * Display the message of the day.
692: */
693: void
694: do_motd(void)
695: {
696: FILE *f;
697: char buf[256];
698:
1.24 markus 699: if (options.print_motd) {
1.28 millert 700: #ifdef HAVE_LOGIN_CAP
701: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
702: "/etc/motd"), "r");
703: #else
1.24 markus 704: f = fopen("/etc/motd", "r");
1.28 millert 705: #endif
1.24 markus 706: if (f) {
707: while (fgets(buf, sizeof(buf), f))
708: fputs(buf, stdout);
709: fclose(f);
710: }
1.2 markus 711: }
1.73 djm 712: }
713:
714:
715: /*
716: * Check for quiet login, either .hushlogin or command given.
717: */
718: int
719: check_quietlogin(Session *s, const char *command)
720: {
721: char buf[256];
722: struct passwd * pw = s->pw;
723: struct stat st;
724:
725: /* Return 1 if .hushlogin exists or a command given. */
726: if (command != NULL)
727: return 1;
728: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
729: #ifdef HAVE_LOGIN_CAP
730: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
731: return 1;
732: #else
733: if (stat(buf, &st) >= 0)
734: return 1;
735: #endif
736: return 0;
1.1 markus 737: }
738:
739: /*
740: * Sets the value of the given variable in the environment. If the variable
741: * already exists, its value is overriden.
742: */
1.4 markus 743: void
1.45 markus 744: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 745: const char *value)
746: {
1.45 markus 747: u_int i, namelen;
1.1 markus 748: char **env;
749:
750: /*
751: * Find the slot where the value should be stored. If the variable
752: * already exists, we reuse the slot; otherwise we append a new slot
753: * at the end of the array, expanding if necessary.
754: */
755: env = *envp;
756: namelen = strlen(name);
757: for (i = 0; env[i]; i++)
758: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
759: break;
760: if (env[i]) {
761: /* Reuse the slot. */
762: xfree(env[i]);
763: } else {
764: /* New variable. Expand if necessary. */
765: if (i >= (*envsizep) - 1) {
766: (*envsizep) += 50;
767: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
768: }
769: /* Need to set the NULL pointer at end of array beyond the new slot. */
770: env[i + 1] = NULL;
771: }
772:
773: /* Allocate space and format the variable in the appropriate slot. */
774: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
775: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
776: }
777:
778: /*
779: * Reads environment variables from the given file and adds/overrides them
780: * into the environment. If the file does not exist, this does nothing.
781: * Otherwise, it must consist of empty lines, comments (line starts with '#')
782: * and assignments of the form name=value. No other forms are allowed.
783: */
1.4 markus 784: void
1.45 markus 785: read_environment_file(char ***env, u_int *envsize,
1.1 markus 786: const char *filename)
787: {
788: FILE *f;
789: char buf[4096];
790: char *cp, *value;
791:
792: f = fopen(filename, "r");
793: if (!f)
794: return;
795:
796: while (fgets(buf, sizeof(buf), f)) {
797: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
798: ;
799: if (!*cp || *cp == '#' || *cp == '\n')
800: continue;
801: if (strchr(cp, '\n'))
802: *strchr(cp, '\n') = '\0';
803: value = strchr(cp, '=');
804: if (value == NULL) {
805: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
806: continue;
807: }
1.14 deraadt 808: /*
809: * Replace the equals sign by nul, and advance value to
810: * the value string.
811: */
1.1 markus 812: *value = '\0';
813: value++;
814: child_set_env(env, envsize, cp, value);
815: }
816: fclose(f);
817: }
818:
819: /*
820: * Performs common processing for the child, such as setting up the
821: * environment, closing extra file descriptors, setting the user and group
822: * ids, and executing the command or shell.
823: */
1.4 markus 824: void
1.60 markus 825: do_child(Session *s, const char *command)
1.1 markus 826: {
1.32 markus 827: const char *shell, *hostname = NULL, *cp = NULL;
1.60 markus 828: struct passwd * pw = s->pw;
1.1 markus 829: char buf[256];
1.16 markus 830: char cmd[1024];
1.27 millert 831: FILE *f = NULL;
1.45 markus 832: u_int envsize, i;
1.1 markus 833: char **env;
834: extern char **environ;
835: struct stat st;
836: char *argv[10];
1.60 markus 837: int do_xauth = s->auth_proto != NULL && s->auth_data != NULL;
1.17 markus 838:
1.74 markus 839: /* remove hostkey from the child's memory */
840: destroy_sensitive_data();
841:
1.17 markus 842: /* login(1) is only called if we execute the login shell */
843: if (options.use_login && command != NULL)
844: options.use_login = 0;
1.1 markus 845:
1.27 millert 846: if (!options.use_login) {
1.28 millert 847: #ifdef HAVE_LOGIN_CAP
848: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
849: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
850: _PATH_NOLOGIN), "r");
851: #else
1.27 millert 852: if (pw->pw_uid)
853: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 854: #endif
1.27 millert 855: if (f) {
856: /* /etc/nologin exists. Print its contents and exit. */
857: while (fgets(buf, sizeof(buf), f))
858: fputs(buf, stderr);
859: fclose(f);
1.1 markus 860: exit(254);
1.27 millert 861: }
1.1 markus 862: }
1.28 millert 863: /* Set login name, uid, gid, and groups. */
1.1 markus 864: /* Login(1) does this as well, and it needs uid 0 for the "-h"
865: switch, so we let login(1) to this for us. */
866: if (!options.use_login) {
867: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 868: #ifdef HAVE_LOGIN_CAP
869: if (setusercontext(lc, pw, pw->pw_uid,
870: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
871: perror("unable to set user context");
872: exit(1);
873: }
874: #else
875: if (setlogin(pw->pw_name) < 0)
876: error("setlogin failed: %s", strerror(errno));
1.1 markus 877: if (setgid(pw->pw_gid) < 0) {
878: perror("setgid");
879: exit(1);
880: }
881: /* Initialize the group list. */
882: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
883: perror("initgroups");
884: exit(1);
885: }
886: endgrent();
887:
888: /* Permanently switch to the desired uid. */
1.71 markus 889: permanently_set_uid(pw);
1.28 millert 890: #endif
1.1 markus 891: }
892: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 893: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 894: }
895: /*
896: * Get the shell from the password data. An empty shell field is
897: * legal, and means /bin/sh.
898: */
899: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 900: #ifdef HAVE_LOGIN_CAP
901: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
902: #endif
1.1 markus 903:
904: #ifdef AFS
905: /* Try to get AFS tokens for the local cell. */
906: if (k_hasafs()) {
907: char cell[64];
908:
909: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
910: krb_afslog(cell, 0);
911:
912: krb_afslog(0, 0);
913: }
914: #endif /* AFS */
915:
916: /* Initialize the environment. */
917: envsize = 100;
918: env = xmalloc(envsize * sizeof(char *));
919: env[0] = NULL;
920:
921: if (!options.use_login) {
922: /* Set basic environment. */
923: child_set_env(&env, &envsize, "USER", pw->pw_name);
924: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
925: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 926: #ifdef HAVE_LOGIN_CAP
1.29 millert 927: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
928: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 929: #else
1.29 millert 930: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 931: #endif
1.1 markus 932:
933: snprintf(buf, sizeof buf, "%.200s/%.50s",
934: _PATH_MAILDIR, pw->pw_name);
935: child_set_env(&env, &envsize, "MAIL", buf);
936:
937: /* Normal systems set SHELL by default. */
938: child_set_env(&env, &envsize, "SHELL", shell);
939: }
940: if (getenv("TZ"))
941: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
942:
943: /* Set custom environment options from RSA authentication. */
944: while (custom_environment) {
945: struct envstring *ce = custom_environment;
946: char *s = ce->s;
947: int i;
948: for (i = 0; s[i] != '=' && s[i]; i++);
949: if (s[i] == '=') {
950: s[i] = 0;
951: child_set_env(&env, &envsize, s, s + i + 1);
952: }
953: custom_environment = ce->next;
954: xfree(ce->s);
955: xfree(ce);
956: }
957:
958: snprintf(buf, sizeof buf, "%.50s %d %d",
959: get_remote_ipaddr(), get_remote_port(), get_local_port());
960: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
961:
1.60 markus 962: if (s->ttyfd != -1)
963: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
964: if (s->term)
965: child_set_env(&env, &envsize, "TERM", s->term);
966: if (s->display)
967: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 968: if (original_command)
969: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
970: original_command);
1.1 markus 971:
972: #ifdef KRB4
973: {
974: extern char *ticket;
975:
976: if (ticket)
977: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
978: }
979: #endif /* KRB4 */
980:
981: if (xauthfile)
982: child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
983: if (auth_get_socket_name() != NULL)
984: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
985: auth_get_socket_name());
986:
987: /* read $HOME/.ssh/environment. */
988: if (!options.use_login) {
1.14 deraadt 989: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
990: pw->pw_dir);
1.1 markus 991: read_environment_file(&env, &envsize, buf);
992: }
993: if (debug_flag) {
994: /* dump the environment */
995: fprintf(stderr, "Environment:\n");
996: for (i = 0; env[i]; i++)
997: fprintf(stderr, " %.200s\n", env[i]);
998: }
1.26 millert 999: /* we have to stash the hostname before we close our socket. */
1000: if (options.use_login)
1.70 stevesk 1001: hostname = get_remote_name_or_ip(utmp_len,
1002: options.reverse_mapping_check);
1.1 markus 1003: /*
1004: * Close the connection descriptors; note that this is the child, and
1005: * the server will still have the socket open, and it is important
1006: * that we do not shutdown it. Note that the descriptors cannot be
1007: * closed before building the environment, as we call
1008: * get_remote_ipaddr there.
1009: */
1010: if (packet_get_connection_in() == packet_get_connection_out())
1011: close(packet_get_connection_in());
1012: else {
1013: close(packet_get_connection_in());
1014: close(packet_get_connection_out());
1015: }
1016: /*
1017: * Close all descriptors related to channels. They will still remain
1018: * open in the parent.
1019: */
1020: /* XXX better use close-on-exec? -markus */
1021: channel_close_all();
1022:
1023: /*
1024: * Close any extra file descriptors. Note that there may still be
1025: * descriptors left by system functions. They will be closed later.
1026: */
1027: endpwent();
1028:
1029: /*
1030: * Close any extra open file descriptors so that we don\'t have them
1031: * hanging around in clients. Note that we want to do this after
1032: * initgroups, because at least on Solaris 2.3 it leaves file
1033: * descriptors open.
1034: */
1035: for (i = 3; i < 64; i++)
1036: close(i);
1037:
1038: /* Change current directory to the user\'s home directory. */
1.28 millert 1039: if (chdir(pw->pw_dir) < 0) {
1.1 markus 1040: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1041: pw->pw_dir, strerror(errno));
1.28 millert 1042: #ifdef HAVE_LOGIN_CAP
1043: if (login_getcapbool(lc, "requirehome", 0))
1044: exit(1);
1045: #endif
1046: }
1.1 markus 1047:
1048: /*
1049: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1050: * xauth are run in the proper environment.
1051: */
1052: environ = env;
1053:
1054: /*
1055: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1056: * in this order).
1057: */
1058: if (!options.use_login) {
1.74 markus 1059: /* ignore _PATH_SSH_USER_RC for subsystems */
1060: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1.75 markus 1061: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
1062: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1.1 markus 1063: if (debug_flag)
1.75 markus 1064: fprintf(stderr, "Running %s\n", cmd);
1065: f = popen(cmd, "w");
1.1 markus 1066: if (f) {
1.60 markus 1067: if (do_xauth)
1068: fprintf(f, "%s %s\n", s->auth_proto,
1069: s->auth_data);
1.1 markus 1070: pclose(f);
1071: } else
1.60 markus 1072: fprintf(stderr, "Could not run %s\n",
1073: _PATH_SSH_USER_RC);
1.50 markus 1074: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 1075: if (debug_flag)
1.60 markus 1076: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
1077: _PATH_SSH_SYSTEM_RC);
1.50 markus 1078: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 1079: if (f) {
1.60 markus 1080: if (do_xauth)
1081: fprintf(f, "%s %s\n", s->auth_proto,
1082: s->auth_data);
1.1 markus 1083: pclose(f);
1084: } else
1.60 markus 1085: fprintf(stderr, "Could not run %s\n",
1086: _PATH_SSH_SYSTEM_RC);
1087: } else if (do_xauth && options.xauth_location != NULL) {
1.1 markus 1088: /* Add authority data to .Xauthority if appropriate. */
1.60 markus 1089: char *screen = strchr(s->display, ':');
1090:
1091: if (debug_flag) {
1092: fprintf(stderr,
1093: "Running %.100s add "
1094: "%.100s %.100s %.100s\n",
1095: options.xauth_location, s->display,
1096: s->auth_proto, s->auth_data);
1097: if (screen != NULL)
1.14 deraadt 1098: fprintf(stderr,
1.60 markus 1099: "Adding %.*s/unix%s %s %s\n",
1100: (int)(screen - s->display),
1101: s->display, screen,
1102: s->auth_proto, s->auth_data);
1103: }
1104: snprintf(cmd, sizeof cmd, "%s -q -",
1105: options.xauth_location);
1106: f = popen(cmd, "w");
1107: if (f) {
1108: fprintf(f, "add %s %s %s\n", s->display,
1109: s->auth_proto, s->auth_data);
1110: if (screen != NULL)
1111: fprintf(f, "add %.*s/unix%s %s %s\n",
1112: (int)(screen - s->display),
1113: s->display, screen,
1114: s->auth_proto,
1115: s->auth_data);
1116: pclose(f);
1117: } else {
1118: fprintf(stderr, "Could not run %s\n",
1119: cmd);
1.1 markus 1120: }
1121: }
1122: /* Get the last component of the shell name. */
1123: cp = strrchr(shell, '/');
1124: if (cp)
1125: cp++;
1126: else
1127: cp = shell;
1128: }
1.67 markus 1129:
1130: /* restore SIGPIPE for child */
1131: signal(SIGPIPE, SIG_DFL);
1132:
1.1 markus 1133: /*
1134: * If we have no command, execute the shell. In this case, the shell
1135: * name to be passed in argv[0] is preceded by '-' to indicate that
1136: * this is a login shell.
1137: */
1138: if (!command) {
1139: if (!options.use_login) {
1140: char buf[256];
1141:
1142: /*
1143: * Check for mail if we have a tty and it was enabled
1144: * in server options.
1145: */
1.60 markus 1146: if (s->ttyfd != -1 && options.check_mail) {
1.1 markus 1147: char *mailbox;
1148: struct stat mailstat;
1.60 markus 1149:
1.1 markus 1150: mailbox = getenv("MAIL");
1151: if (mailbox != NULL) {
1.14 deraadt 1152: if (stat(mailbox, &mailstat) != 0 ||
1153: mailstat.st_size == 0)
1.1 markus 1154: printf("No mail.\n");
1155: else if (mailstat.st_mtime < mailstat.st_atime)
1156: printf("You have mail.\n");
1157: else
1158: printf("You have new mail.\n");
1159: }
1160: }
1161: /* Start the shell. Set initial character to '-'. */
1162: buf[0] = '-';
1163: strncpy(buf + 1, cp, sizeof(buf) - 1);
1164: buf[sizeof(buf) - 1] = 0;
1165:
1166: /* Execute the shell. */
1167: argv[0] = buf;
1168: argv[1] = NULL;
1169: execve(shell, argv, env);
1170:
1171: /* Executing the shell failed. */
1172: perror(shell);
1173: exit(1);
1174:
1175: } else {
1176: /* Launch login(1). */
1177:
1.26 millert 1178: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1179: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1180:
1181: /* Login couldn't be executed, die. */
1182:
1183: perror("login");
1184: exit(1);
1185: }
1186: }
1187: /*
1188: * Execute the command using the user's shell. This uses the -c
1189: * option to execute the command.
1190: */
1191: argv[0] = (char *) cp;
1192: argv[1] = "-c";
1193: argv[2] = (char *) command;
1194: argv[3] = NULL;
1195: execve(shell, argv, env);
1196: perror(shell);
1197: exit(1);
1198: }
1199:
1200: Session *
1201: session_new(void)
1202: {
1203: int i;
1204: static int did_init = 0;
1205: if (!did_init) {
1206: debug("session_new: init");
1207: for(i = 0; i < MAX_SESSIONS; i++) {
1208: sessions[i].used = 0;
1209: sessions[i].self = i;
1210: }
1211: did_init = 1;
1212: }
1213: for(i = 0; i < MAX_SESSIONS; i++) {
1214: Session *s = &sessions[i];
1215: if (! s->used) {
1.68 djm 1216: memset(s, 0, sizeof(*s));
1.1 markus 1217: s->chanid = -1;
1218: s->ptyfd = -1;
1219: s->ttyfd = -1;
1220: s->used = 1;
1221: debug("session_new: session %d", i);
1222: return s;
1223: }
1224: }
1225: return NULL;
1226: }
1227:
1228: void
1229: session_dump(void)
1230: {
1231: int i;
1232: for(i = 0; i < MAX_SESSIONS; i++) {
1233: Session *s = &sessions[i];
1234: debug("dump: used %d session %d %p channel %d pid %d",
1235: s->used,
1236: s->self,
1237: s,
1238: s->chanid,
1239: s->pid);
1240: }
1241: }
1242:
1.2 markus 1243: int
1244: session_open(int chanid)
1245: {
1246: Session *s = session_new();
1247: debug("session_open: channel %d", chanid);
1248: if (s == NULL) {
1249: error("no more sessions");
1250: return 0;
1251: }
1.7 markus 1252: s->pw = auth_get_user();
1253: if (s->pw == NULL)
1.54 stevesk 1254: fatal("no user for session %d", s->self);
1.2 markus 1255: debug("session_open: session %d: link with channel %d", s->self, chanid);
1256: s->chanid = chanid;
1257: return 1;
1258: }
1259:
1260: Session *
1261: session_by_channel(int id)
1262: {
1263: int i;
1264: for(i = 0; i < MAX_SESSIONS; i++) {
1265: Session *s = &sessions[i];
1266: if (s->used && s->chanid == id) {
1267: debug("session_by_channel: session %d channel %d", i, id);
1268: return s;
1269: }
1270: }
1271: debug("session_by_channel: unknown channel %d", id);
1272: session_dump();
1273: return NULL;
1274: }
1275:
1276: Session *
1277: session_by_pid(pid_t pid)
1278: {
1279: int i;
1280: debug("session_by_pid: pid %d", pid);
1281: for(i = 0; i < MAX_SESSIONS; i++) {
1282: Session *s = &sessions[i];
1283: if (s->used && s->pid == pid)
1284: return s;
1285: }
1286: error("session_by_pid: unknown pid %d", pid);
1287: session_dump();
1288: return NULL;
1289: }
1290:
1291: int
1292: session_window_change_req(Session *s)
1293: {
1294: s->col = packet_get_int();
1295: s->row = packet_get_int();
1296: s->xpixel = packet_get_int();
1297: s->ypixel = packet_get_int();
1.3 markus 1298: packet_done();
1.2 markus 1299: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1300: return 1;
1301: }
1302:
1303: int
1304: session_pty_req(Session *s)
1305: {
1.45 markus 1306: u_int len;
1.72 stevesk 1307: int n_bytes;
1.2 markus 1308:
1.19 markus 1309: if (no_pty_flag)
1310: return 0;
1.2 markus 1311: if (s->ttyfd != -1)
1.3 markus 1312: return 0;
1.2 markus 1313: s->term = packet_get_string(&len);
1314: s->col = packet_get_int();
1315: s->row = packet_get_int();
1316: s->xpixel = packet_get_int();
1317: s->ypixel = packet_get_int();
1318:
1319: if (strcmp(s->term, "") == 0) {
1320: xfree(s->term);
1321: s->term = NULL;
1322: }
1323: /* Allocate a pty and open it. */
1324: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1325: xfree(s->term);
1326: s->term = NULL;
1327: s->ptyfd = -1;
1328: s->ttyfd = -1;
1329: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1330: return 0;
1.2 markus 1331: }
1332: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1333: /*
1334: * Add a cleanup function to clear the utmp entry and record logout
1335: * time in case we call fatal() (e.g., the connection gets closed).
1336: */
1337: fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1338: pty_setowner(s->pw, s->tty);
1339: /* Get window size from the packet. */
1340: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1341:
1.72 stevesk 1342: /* Get tty modes from the packet. */
1343: tty_parse_modes(s->ttyfd, &n_bytes);
1344: packet_done();
1345:
1.9 markus 1346: session_proctitle(s);
1347:
1.2 markus 1348: return 1;
1349: }
1350:
1.7 markus 1351: int
1352: session_subsystem_req(Session *s)
1353: {
1.45 markus 1354: u_int len;
1.7 markus 1355: int success = 0;
1356: char *subsys = packet_get_string(&len);
1.18 jakob 1357: int i;
1.7 markus 1358:
1359: packet_done();
1360: log("subsystem request for %s", subsys);
1.18 jakob 1361:
1362: for (i = 0; i < options.num_subsystems; i++) {
1363: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1364: debug("subsystem: exec() %s", options.subsystem_command[i]);
1.64 markus 1365: s->is_subsystem = 1;
1.63 markus 1366: do_exec_no_pty(s, options.subsystem_command[i]);
1.18 jakob 1367: success = 1;
1368: }
1369: }
1370:
1371: if (!success)
1372: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1373:
1374: xfree(subsys);
1375: return success;
1376: }
1377:
1378: int
1379: session_x11_req(Session *s)
1380: {
1.33 markus 1381: int fd;
1.76 djm 1382: struct stat st;
1.22 deraadt 1383: if (no_x11_forwarding_flag) {
1.19 markus 1384: debug("X11 forwarding disabled in user configuration file.");
1385: return 0;
1386: }
1.7 markus 1387: if (!options.x11_forwarding) {
1388: debug("X11 forwarding disabled in server configuration file.");
1.76 djm 1389: return 0;
1390: }
1391: if (!options.xauth_location ||
1392: (stat(options.xauth_location, &st) == -1)) {
1393: packet_send_debug("No xauth program; cannot forward with spoofing.");
1.7 markus 1394: return 0;
1395: }
1396: if (xauthfile != NULL) {
1397: debug("X11 fwd already started.");
1398: return 0;
1399: }
1400:
1401: debug("Received request for X11 forwarding with auth spoofing.");
1402: if (s->display != NULL)
1403: packet_disconnect("Protocol error: X11 display already set.");
1404:
1405: s->single_connection = packet_get_char();
1406: s->auth_proto = packet_get_string(NULL);
1407: s->auth_data = packet_get_string(NULL);
1408: s->screen = packet_get_int();
1409: packet_done();
1410:
1411: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1412: if (s->display == NULL) {
1413: xfree(s->auth_proto);
1414: xfree(s->auth_data);
1415: return 0;
1416: }
1417: xauthfile = xmalloc(MAXPATHLEN);
1418: strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1.71 markus 1419: temporarily_use_uid(s->pw);
1.7 markus 1420: if (mkdtemp(xauthfile) == NULL) {
1421: restore_uid();
1422: error("private X11 dir: mkdtemp %s failed: %s",
1423: xauthfile, strerror(errno));
1424: xfree(xauthfile);
1425: xauthfile = NULL;
1426: xfree(s->auth_proto);
1427: xfree(s->auth_data);
1428: /* XXXX remove listening channels */
1429: return 0;
1430: }
1431: strlcat(xauthfile, "/cookies", MAXPATHLEN);
1.33 markus 1432: fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1433: if (fd >= 0)
1434: close(fd);
1.7 markus 1435: restore_uid();
1436: fatal_add_cleanup(xauthfile_cleanup_proc, s);
1437: return 1;
1438: }
1439:
1.19 markus 1440: int
1441: session_shell_req(Session *s)
1442: {
1443: /* if forced_command == NULL, the shell is execed */
1444: char *shell = forced_command;
1445: packet_done();
1446: if (s->ttyfd == -1)
1.63 markus 1447: do_exec_no_pty(s, shell);
1.19 markus 1448: else
1.63 markus 1449: do_exec_pty(s, shell);
1.19 markus 1450: return 1;
1451: }
1452:
1453: int
1454: session_exec_req(Session *s)
1455: {
1.45 markus 1456: u_int len;
1.19 markus 1457: char *command = packet_get_string(&len);
1458: packet_done();
1459: if (forced_command) {
1.34 markus 1460: original_command = command;
1.19 markus 1461: command = forced_command;
1462: debug("Forced command '%.500s'", forced_command);
1463: }
1464: if (s->ttyfd == -1)
1.63 markus 1465: do_exec_no_pty(s, command);
1.19 markus 1466: else
1.63 markus 1467: do_exec_pty(s, command);
1.19 markus 1468: if (forced_command == NULL)
1469: xfree(command);
1470: return 1;
1471: }
1472:
1.43 markus 1473: int
1474: session_auth_agent_req(Session *s)
1475: {
1476: static int called = 0;
1477: packet_done();
1.44 markus 1478: if (no_agent_forwarding_flag) {
1479: debug("session_auth_agent_req: no_agent_forwarding_flag");
1480: return 0;
1481: }
1.43 markus 1482: if (called) {
1483: return 0;
1484: } else {
1485: called = 1;
1486: return auth_input_request_forwarding(s->pw);
1487: }
1488: }
1489:
1.2 markus 1490: void
1491: session_input_channel_req(int id, void *arg)
1492: {
1.45 markus 1493: u_int len;
1.2 markus 1494: int reply;
1495: int success = 0;
1496: char *rtype;
1497: Session *s;
1498: Channel *c;
1499:
1500: rtype = packet_get_string(&len);
1501: reply = packet_get_char();
1502:
1503: s = session_by_channel(id);
1504: if (s == NULL)
1505: fatal("session_input_channel_req: channel %d: no session", id);
1506: c = channel_lookup(id);
1507: if (c == NULL)
1508: fatal("session_input_channel_req: channel %d: bad channel", id);
1509:
1510: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1511: s->self, id, rtype, reply);
1512:
1513: /*
1.64 markus 1514: * a session is in LARVAL state until a shell, a command
1515: * or a subsystem is executed
1.2 markus 1516: */
1517: if (c->type == SSH_CHANNEL_LARVAL) {
1518: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1519: success = session_shell_req(s);
1.2 markus 1520: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1521: success = session_exec_req(s);
1.2 markus 1522: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1523: success = session_pty_req(s);
1.7 markus 1524: } else if (strcmp(rtype, "x11-req") == 0) {
1525: success = session_x11_req(s);
1.43 markus 1526: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1527: success = session_auth_agent_req(s);
1.7 markus 1528: } else if (strcmp(rtype, "subsystem") == 0) {
1529: success = session_subsystem_req(s);
1.2 markus 1530: }
1531: }
1532: if (strcmp(rtype, "window-change") == 0) {
1533: success = session_window_change_req(s);
1534: }
1535:
1536: if (reply) {
1537: packet_start(success ?
1538: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1539: packet_put_int(c->remote_id);
1540: packet_send();
1541: }
1542: xfree(rtype);
1543: }
1544:
1545: void
1546: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1547: {
1548: if (!compat20)
1549: fatal("session_set_fds: called for proto != 2.0");
1550: /*
1551: * now that have a child and a pipe to the child,
1552: * we can activate our channel and register the fd's
1553: */
1554: if (s->chanid == -1)
1555: fatal("no channel for session %d", s->self);
1556: channel_set_fds(s->chanid,
1557: fdout, fdin, fderr,
1.42 markus 1558: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1559: 1);
1.2 markus 1560: }
1561:
1.1 markus 1562: void
1563: session_pty_cleanup(Session *s)
1564: {
1565: if (s == NULL || s->ttyfd == -1)
1566: return;
1567:
1.54 stevesk 1568: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1569:
1570: /* Cancel the cleanup function. */
1571: fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1572:
1573: /* Record that the user has logged out. */
1574: record_logout(s->pid, s->tty);
1575:
1576: /* Release the pseudo-tty. */
1577: pty_release(s->tty);
1578:
1579: /*
1580: * Close the server side of the socket pairs. We must do this after
1581: * the pty cleanup, so that another process doesn't get this pty
1582: * while we're still cleaning up.
1583: */
1584: if (close(s->ptymaster) < 0)
1585: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1586: }
1587:
1588: void
1589: session_exit_message(Session *s, int status)
1590: {
1591: Channel *c;
1592: if (s == NULL)
1593: fatal("session_close: no session");
1594: c = channel_lookup(s->chanid);
1595: if (c == NULL)
1596: fatal("session_close: session %d: no channel %d",
1597: s->self, s->chanid);
1598: debug("session_exit_message: session %d channel %d pid %d",
1599: s->self, s->chanid, s->pid);
1600:
1601: if (WIFEXITED(status)) {
1602: channel_request_start(s->chanid,
1603: "exit-status", 0);
1604: packet_put_int(WEXITSTATUS(status));
1605: packet_send();
1606: } else if (WIFSIGNALED(status)) {
1607: channel_request_start(s->chanid,
1608: "exit-signal", 0);
1609: packet_put_int(WTERMSIG(status));
1610: packet_put_char(WCOREDUMP(status));
1611: packet_put_cstring("");
1612: packet_put_cstring("");
1613: packet_send();
1614: } else {
1615: /* Some weird exit cause. Just exit. */
1616: packet_disconnect("wait returned status %04x.", status);
1617: }
1618:
1619: /* disconnect channel */
1620: debug("session_exit_message: release channel %d", s->chanid);
1621: channel_cancel_cleanup(s->chanid);
1.5 markus 1622: /*
1623: * emulate a write failure with 'chan_write_failed', nobody will be
1624: * interested in data we write.
1625: * Note that we must not call 'chan_read_failed', since there could
1626: * be some more data waiting in the pipe.
1627: */
1.8 markus 1628: if (c->ostate != CHAN_OUTPUT_CLOSED)
1629: chan_write_failed(c);
1.2 markus 1630: s->chanid = -1;
1631: }
1632:
1633: void
1634: session_free(Session *s)
1635: {
1636: debug("session_free: session %d pid %d", s->self, s->pid);
1637: if (s->term)
1638: xfree(s->term);
1639: if (s->display)
1640: xfree(s->display);
1641: if (s->auth_data)
1642: xfree(s->auth_data);
1643: if (s->auth_proto)
1644: xfree(s->auth_proto);
1645: s->used = 0;
1646: }
1647:
1648: void
1649: session_close(Session *s)
1650: {
1651: session_pty_cleanup(s);
1652: session_free(s);
1.9 markus 1653: session_proctitle(s);
1.2 markus 1654: }
1655:
1656: void
1657: session_close_by_pid(pid_t pid, int status)
1658: {
1659: Session *s = session_by_pid(pid);
1660: if (s == NULL) {
1661: debug("session_close_by_pid: no session for pid %d", s->pid);
1662: return;
1663: }
1664: if (s->chanid != -1)
1665: session_exit_message(s, status);
1666: session_close(s);
1667: }
1668:
1669: /*
1670: * this is called when a channel dies before
1671: * the session 'child' itself dies
1672: */
1673: void
1674: session_close_by_channel(int id, void *arg)
1675: {
1676: Session *s = session_by_channel(id);
1677: if (s == NULL) {
1678: debug("session_close_by_channel: no session for channel %d", id);
1679: return;
1680: }
1681: /* disconnect channel */
1682: channel_cancel_cleanup(s->chanid);
1683: s->chanid = -1;
1684:
1685: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1686: if (s->pid == 0) {
1687: /* close session immediately */
1688: session_close(s);
1689: } else {
1690: /* notify child, delay session cleanup */
1691: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1692: error("session_close_by_channel: kill %d: %s",
1693: s->pid, strerror(errno));
1694: }
1.9 markus 1695: }
1696:
1697: char *
1698: session_tty_list(void)
1699: {
1700: static char buf[1024];
1701: int i;
1702: buf[0] = '\0';
1703: for(i = 0; i < MAX_SESSIONS; i++) {
1704: Session *s = &sessions[i];
1705: if (s->used && s->ttyfd != -1) {
1706: if (buf[0] != '\0')
1707: strlcat(buf, ",", sizeof buf);
1708: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1709: }
1710: }
1711: if (buf[0] == '\0')
1712: strlcpy(buf, "notty", sizeof buf);
1713: return buf;
1714: }
1715:
1716: void
1717: session_proctitle(Session *s)
1718: {
1719: if (s->pw == NULL)
1720: error("no user for session %d", s->self);
1721: else
1722: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1723: }
1724:
1725: void
1.49 markus 1726: do_authenticated2(Authctxt *authctxt)
1.2 markus 1727: {
1.65 markus 1728:
1.2 markus 1729: server_loop2();
1.1 markus 1730: }
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