Annotation of src/usr.bin/ssh/session.c, Revision 1.42.2.8
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.
1.42.2.6 miod 12: * Copyright (c) 2000, 2001 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"
1.42.2.8! brad 36: RCSID("$OpenBSD: session.c,v 1.128 2002/02/16 00:51:44 markus Exp $");
1.1 markus 37:
38: #include "ssh.h"
1.42.2.1 jason 39: #include "ssh1.h"
40: #include "ssh2.h"
41: #include "xmalloc.h"
1.42.2.3 jason 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"
1.2 markus 49: #include "bufaux.h"
50: #include "auth.h"
1.19 markus 51: #include "auth-options.h"
1.42.2.1 jason 52: #include "pathnames.h"
53: #include "log.h"
54: #include "servconf.h"
1.42.2.3 jason 55: #include "sshlogin.h"
1.42.2.1 jason 56: #include "serverloop.h"
57: #include "canohost.h"
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;
1.42.2.6 miod 67: struct passwd *pw;
68: Authctxt *authctxt;
1.1 markus 69: pid_t pid;
70: /* tty */
71: char *term;
72: int ptyfd, ttyfd, ptymaster;
73: int row, col, xpixel, ypixel;
74: char tty[TTYSZ];
75: /* X11 */
1.42.2.8! brad 76: int display_number;
1.1 markus 77: char *display;
78: int screen;
1.42.2.8! brad 79: char *auth_display;
1.1 markus 80: char *auth_proto;
81: char *auth_data;
1.7 markus 82: int single_connection;
1.1 markus 83: /* proto 2 */
84: int chanid;
1.42.2.4 jason 85: int is_subsystem;
1.1 markus 86: };
87:
88: /* func */
89:
90: Session *session_new(void);
1.42.2.6 miod 91: void session_set_fds(Session *, int, int, int);
92: static void session_pty_cleanup(void *);
93: void session_proctitle(Session *);
94: int session_setup_x11fwd(Session *);
95: void do_exec_pty(Session *, const char *);
96: void do_exec_no_pty(Session *, const char *);
97: void do_exec(Session *, const char *);
98: void do_login(Session *, const char *);
99: void do_child(Session *, const char *);
1.42.2.4 jason 100: void do_motd(void);
1.42.2.6 miod 101: int check_quietlogin(Session *, const char *);
1.42.2.4 jason 102:
1.42.2.6 miod 103: static void do_authenticated1(Authctxt *);
104: static void do_authenticated2(Authctxt *);
105:
106: static void session_close(Session *);
107: static int session_pty_req(Session *);
1.1 markus 108:
109: /* import */
110: extern ServerOptions options;
111: extern char *__progname;
112: extern int log_stderr;
113: extern int debug_flag;
1.42.2.1 jason 114: extern u_int utmp_len;
1.21 markus 115: extern int startup_pipe;
1.42.2.4 jason 116: extern void destroy_sensitive_data(void);
1.21 markus 117:
1.34 markus 118: /* original command from peer. */
1.42.2.6 miod 119: const char *original_command = NULL;
1.34 markus 120:
1.1 markus 121: /* data */
122: #define MAX_SESSIONS 10
123: Session sessions[MAX_SESSIONS];
124:
1.28 millert 125: #ifdef HAVE_LOGIN_CAP
126: static login_cap_t *lc;
127: #endif
128:
1.42.2.4 jason 129: void
130: do_authenticated(Authctxt *authctxt)
131: {
132: /*
133: * Cancel the alarm we set to limit the time taken for
134: * authentication.
135: */
136: alarm(0);
137: if (startup_pipe != -1) {
138: close(startup_pipe);
139: startup_pipe = -1;
140: }
141: #ifdef HAVE_LOGIN_CAP
142: if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
143: error("unable to get login class");
144: return;
145: }
146: #ifdef BSD_AUTH
147: if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) {
148: packet_disconnect("Approval failure for %s",
149: authctxt->pw->pw_name);
150: }
151: #endif
152: #endif
153: /* setup the channel layer */
154: if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
155: channel_permit_all_opens();
156:
157: if (compat20)
158: do_authenticated2(authctxt);
159: else
160: do_authenticated1(authctxt);
161:
1.42.2.5 miod 162: /* remove agent socket */
163: if (auth_get_socket_name())
164: auth_sock_cleanup_proc(authctxt->pw);
1.42.2.6 miod 165: #ifdef KRB4
166: if (options.kerberos_ticket_cleanup)
167: krb4_cleanup_proc(authctxt);
168: #endif
169: #ifdef KRB5
170: if (options.kerberos_ticket_cleanup)
171: krb5_cleanup_proc(authctxt);
172: #endif
1.1 markus 173: }
174:
175: /*
176: * Prepares for an interactive session. This is called after the user has
177: * been successfully authenticated. During this message exchange, pseudo
178: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
179: * are requested, etc.
180: */
1.42.2.6 miod 181: static void
1.42.2.4 jason 182: do_authenticated1(Authctxt *authctxt)
1.1 markus 183: {
184: Session *s;
185: char *command;
1.42.2.8! brad 186: int success, type, screen_flag;
1.42.2.4 jason 187: int compression_level = 0, enable_compression_after_reply = 0;
1.42.2.1 jason 188: u_int proto_len, data_len, dlen;
1.1 markus 189:
190: s = session_new();
1.42.2.6 miod 191: s->authctxt = authctxt;
1.42.2.4 jason 192: s->pw = authctxt->pw;
1.28 millert 193:
1.1 markus 194: /*
195: * We stay in this loop until the client requests to execute a shell
196: * or a command.
197: */
198: for (;;) {
1.42.2.4 jason 199: success = 0;
1.1 markus 200:
201: /* Get a packet from the client. */
1.42.2.8! brad 202: type = packet_read();
1.1 markus 203:
204: /* Process the packet. */
205: switch (type) {
206: case SSH_CMSG_REQUEST_COMPRESSION:
207: compression_level = packet_get_int();
1.42.2.8! brad 208: packet_check_eom();
1.1 markus 209: if (compression_level < 1 || compression_level > 9) {
210: packet_send_debug("Received illegal compression level %d.",
1.42.2.8! brad 211: compression_level);
1.1 markus 212: break;
213: }
214: /* Enable compression after we have responded with SUCCESS. */
215: enable_compression_after_reply = 1;
216: success = 1;
217: break;
218:
219: case SSH_CMSG_REQUEST_PTY:
1.42.2.6 miod 220: success = session_pty_req(s);
1.1 markus 221: break;
222:
223: case SSH_CMSG_X11_REQUEST_FORWARDING:
224: s->auth_proto = packet_get_string(&proto_len);
225: s->auth_data = packet_get_string(&data_len);
226:
1.42.2.3 jason 227: screen_flag = packet_get_protocol_flags() &
228: SSH_PROTOFLAG_SCREEN_NUMBER;
229: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
230:
231: if (packet_remaining() == 4) {
232: if (!screen_flag)
233: debug2("Buggy client: "
234: "X11 screen flag missing");
1.1 markus 235: s->screen = packet_get_int();
1.42.2.1 jason 236: } else {
1.1 markus 237: s->screen = 0;
1.42.2.1 jason 238: }
1.42.2.8! brad 239: packet_check_eom();
1.42.2.6 miod 240: success = session_setup_x11fwd(s);
241: if (!success) {
242: xfree(s->auth_proto);
243: xfree(s->auth_data);
244: s->auth_proto = NULL;
245: s->auth_data = NULL;
246: }
1.1 markus 247: break;
248:
249: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
250: if (no_agent_forwarding_flag || compat13) {
251: debug("Authentication agent forwarding not permitted for this authentication.");
252: break;
253: }
254: debug("Received authentication agent forwarding request.");
1.42.2.4 jason 255: success = auth_input_request_forwarding(s->pw);
1.1 markus 256: break;
257:
258: case SSH_CMSG_PORT_FORWARD_REQUEST:
259: if (no_port_forwarding_flag) {
260: debug("Port forwarding not permitted for this authentication.");
1.39 markus 261: break;
262: }
263: if (!options.allow_tcp_forwarding) {
264: debug("Port forwarding not permitted.");
1.1 markus 265: break;
266: }
267: debug("Received TCP/IP port forwarding request.");
1.42.2.4 jason 268: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 269: success = 1;
270: break;
271:
272: case SSH_CMSG_MAX_PACKET_SIZE:
273: if (packet_set_maxsize(packet_get_int()) > 0)
274: success = 1;
275: break;
1.42.2.8! brad 276:
1.42.2.6 miod 277: #if defined(AFS) || defined(KRB5)
278: case SSH_CMSG_HAVE_KERBEROS_TGT:
279: if (!options.kerberos_tgt_passing) {
280: verbose("Kerberos TGT passing disabled.");
281: } else {
282: char *kdata = packet_get_string(&dlen);
1.42.2.8! brad 283: packet_check_eom();
! 284:
1.42.2.6 miod 285: /* XXX - 0x41, see creds_to_radix version */
286: if (kdata[0] != 0x41) {
287: #ifdef KRB5
288: krb5_data tgt;
289: tgt.data = kdata;
290: tgt.length = dlen;
1.42.2.8! brad 291:
1.42.2.6 miod 292: if (auth_krb5_tgt(s->authctxt, &tgt))
293: success = 1;
294: else
295: verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user);
296: #endif /* KRB5 */
297: } else {
298: #ifdef AFS
299: if (auth_krb4_tgt(s->authctxt, kdata))
300: success = 1;
301: else
302: verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user);
303: #endif /* AFS */
304: }
305: xfree(kdata);
306: }
307: break;
308: #endif /* AFS || KRB5 */
1.42.2.8! brad 309:
1.42.2.6 miod 310: #ifdef AFS
311: case SSH_CMSG_HAVE_AFS_TOKEN:
312: if (!options.afs_token_passing || !k_hasafs()) {
313: verbose("AFS token passing disabled.");
314: } else {
315: /* Accept AFS token. */
316: char *token = packet_get_string(&dlen);
1.42.2.8! brad 317: packet_check_eom();
! 318:
1.42.2.6 miod 319: if (auth_afs_token(s->authctxt, token))
320: success = 1;
321: else
322: verbose("AFS token refused for %.100s",
323: s->authctxt->user);
324: xfree(token);
325: }
326: break;
327: #endif /* AFS */
1.1 markus 328:
329: case SSH_CMSG_EXEC_SHELL:
330: case SSH_CMSG_EXEC_CMD:
331: if (type == SSH_CMSG_EXEC_CMD) {
332: command = packet_get_string(&dlen);
333: debug("Exec command '%.500s'", command);
1.42.2.6 miod 334: do_exec(s, command);
335: xfree(command);
1.1 markus 336: } else {
1.42.2.6 miod 337: do_exec(s, NULL);
1.1 markus 338: }
1.42.2.8! brad 339: packet_check_eom();
1.42.2.6 miod 340: session_close(s);
1.1 markus 341: return;
342:
343: default:
344: /*
345: * Any unknown messages in this phase are ignored,
346: * and a failure message is returned.
347: */
348: log("Unknown packet type received after authentication: %d", type);
349: }
350: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
351: packet_send();
352: packet_write_wait();
353:
354: /* Enable compression now that we have replied if appropriate. */
355: if (enable_compression_after_reply) {
356: enable_compression_after_reply = 0;
357: packet_start_compression(compression_level);
358: }
359: }
360: }
361:
362: /*
363: * This is called to fork and execute a command when we have no tty. This
364: * will call do_child from the child, and server_loop from the parent after
365: * setting up file descriptors and such.
366: */
1.4 markus 367: void
1.42.2.4 jason 368: do_exec_no_pty(Session *s, const char *command)
1.1 markus 369: {
370: int pid;
371:
372: #ifdef USE_PIPES
373: int pin[2], pout[2], perr[2];
374: /* Allocate pipes for communicating with the program. */
375: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
376: packet_disconnect("Could not create pipes: %.100s",
377: strerror(errno));
378: #else /* USE_PIPES */
379: int inout[2], err[2];
380: /* Uses socket pairs to communicate with the program. */
381: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
382: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
383: packet_disconnect("Could not create socket pairs: %.100s",
384: strerror(errno));
385: #endif /* USE_PIPES */
386: if (s == NULL)
387: fatal("do_exec_no_pty: no session");
388:
1.9 markus 389: session_proctitle(s);
1.1 markus 390:
391: /* Fork the child. */
392: if ((pid = fork()) == 0) {
393: /* Child. Reinitialize the log since the pid has changed. */
394: log_init(__progname, options.log_level, options.log_facility, log_stderr);
395:
396: /*
397: * Create a new session and process group since the 4.4BSD
398: * setlogin() affects the entire process group.
399: */
400: if (setsid() < 0)
401: error("setsid failed: %.100s", strerror(errno));
402:
403: #ifdef USE_PIPES
404: /*
405: * Redirect stdin. We close the parent side of the socket
406: * pair, and make the child side the standard input.
407: */
408: close(pin[1]);
409: if (dup2(pin[0], 0) < 0)
410: perror("dup2 stdin");
411: close(pin[0]);
412:
413: /* Redirect stdout. */
414: close(pout[0]);
415: if (dup2(pout[1], 1) < 0)
416: perror("dup2 stdout");
417: close(pout[1]);
418:
419: /* Redirect stderr. */
420: close(perr[0]);
421: if (dup2(perr[1], 2) < 0)
422: perror("dup2 stderr");
423: close(perr[1]);
424: #else /* USE_PIPES */
425: /*
426: * Redirect stdin, stdout, and stderr. Stdin and stdout will
427: * use the same socket, as some programs (particularly rdist)
428: * seem to depend on it.
429: */
430: close(inout[1]);
431: close(err[1]);
432: if (dup2(inout[0], 0) < 0) /* stdin */
433: perror("dup2 stdin");
434: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
435: perror("dup2 stdout");
436: if (dup2(err[0], 2) < 0) /* stderr */
437: perror("dup2 stderr");
438: #endif /* USE_PIPES */
439:
440: /* Do processing for the child (exec command etc). */
1.42.2.3 jason 441: do_child(s, command);
1.1 markus 442: /* NOTREACHED */
443: }
444: if (pid < 0)
445: packet_disconnect("fork failed: %.100s", strerror(errno));
446: s->pid = pid;
1.42.2.1 jason 447: /* Set interactive/non-interactive mode. */
448: packet_set_interactive(s->display != NULL);
1.1 markus 449: #ifdef USE_PIPES
450: /* We are the parent. Close the child sides of the pipes. */
451: close(pin[0]);
452: close(pout[1]);
453: close(perr[1]);
454:
1.2 markus 455: if (compat20) {
1.42.2.4 jason 456: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 457: } else {
458: /* Enter the interactive session. */
459: server_loop(pid, pin[1], pout[0], perr[0]);
1.42.2.4 jason 460: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 461: }
1.1 markus 462: #else /* USE_PIPES */
463: /* We are the parent. Close the child sides of the socket pairs. */
464: close(inout[0]);
465: close(err[0]);
466:
467: /*
468: * Enter the interactive session. Note: server_loop must be able to
469: * handle the case that fdin and fdout are the same.
470: */
1.2 markus 471: if (compat20) {
1.42.2.4 jason 472: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 473: } else {
474: server_loop(pid, inout[1], inout[1], err[1]);
475: /* server_loop has closed inout[1] and err[1]. */
476: }
1.1 markus 477: #endif /* USE_PIPES */
478: }
479:
480: /*
481: * This is called to fork and execute a command when we have a tty. This
482: * will call do_child from the child, and server_loop from the parent after
483: * setting up file descriptors, controlling tty, updating wtmp, utmp,
484: * lastlog, and other such operations.
485: */
1.4 markus 486: void
1.42.2.4 jason 487: do_exec_pty(Session *s, const char *command)
1.1 markus 488: {
489: int fdout, ptyfd, ttyfd, ptymaster;
490: pid_t pid;
491:
492: if (s == NULL)
493: fatal("do_exec_pty: no session");
494: ptyfd = s->ptyfd;
495: ttyfd = s->ttyfd;
496:
497: /* Fork the child. */
498: if ((pid = fork()) == 0) {
1.42.2.6 miod 499:
1.24 markus 500: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 501: log_init(__progname, options.log_level, options.log_facility, log_stderr);
502: /* Close the master side of the pseudo tty. */
503: close(ptyfd);
504:
505: /* Make the pseudo tty our controlling tty. */
506: pty_make_controlling_tty(&ttyfd, s->tty);
507:
1.42.2.7 miod 508: /* Redirect stdin/stdout/stderr from the pseudo tty. */
509: if (dup2(ttyfd, 0) < 0)
510: error("dup2 stdin: %s", strerror(errno));
511: if (dup2(ttyfd, 1) < 0)
512: error("dup2 stdout: %s", strerror(errno));
513: if (dup2(ttyfd, 2) < 0)
514: error("dup2 stderr: %s", strerror(errno));
1.1 markus 515:
516: /* Close the extra descriptor for the pseudo tty. */
517: close(ttyfd);
518:
1.24 markus 519: /* record login, etc. similar to login(1) */
1.41 markus 520: if (!(options.use_login && command == NULL))
521: do_login(s, command);
1.1 markus 522:
523: /* Do common processing for the child, such as execing the command. */
1.42.2.3 jason 524: do_child(s, command);
1.1 markus 525: /* NOTREACHED */
526: }
527: if (pid < 0)
528: packet_disconnect("fork failed: %.100s", strerror(errno));
529: s->pid = pid;
530:
531: /* Parent. Close the slave side of the pseudo tty. */
532: close(ttyfd);
533:
534: /*
535: * Create another descriptor of the pty master side for use as the
536: * standard input. We could use the original descriptor, but this
537: * simplifies code in server_loop. The descriptor is bidirectional.
538: */
539: fdout = dup(ptyfd);
540: if (fdout < 0)
541: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
542:
543: /* we keep a reference to the pty master */
544: ptymaster = dup(ptyfd);
545: if (ptymaster < 0)
546: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
547: s->ptymaster = ptymaster;
548:
549: /* Enter interactive session. */
1.42.2.1 jason 550: packet_set_interactive(1);
1.2 markus 551: if (compat20) {
552: session_set_fds(s, ptyfd, fdout, -1);
553: } else {
554: server_loop(pid, ptyfd, fdout, -1);
555: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 556: }
557: }
558:
1.42.2.6 miod 559: /*
560: * This is called to fork and execute a command. If another command is
561: * to be forced, execute that instead.
562: */
563: void
564: do_exec(Session *s, const char *command)
565: {
566: if (forced_command) {
567: original_command = command;
568: command = forced_command;
569: debug("Forced command '%.900s'", command);
570: }
571:
572: if (s->ttyfd != -1)
573: do_exec_pty(s, command);
574: else
575: do_exec_no_pty(s, command);
576:
577: original_command = NULL;
578: }
579:
580:
1.24 markus 581: /* administrative, login(1)-like work */
582: void
1.41 markus 583: do_login(Session *s, const char *command)
1.24 markus 584: {
585: char *time_string;
1.35 markus 586: char hostname[MAXHOSTNAMELEN];
1.24 markus 587: socklen_t fromlen;
588: struct sockaddr_storage from;
589: time_t last_login_time;
590: struct passwd * pw = s->pw;
591: pid_t pid = getpid();
592:
593: /*
594: * Get IP address of client. If the connection is not a socket, let
595: * the address be 0.0.0.0.
596: */
597: memset(&from, 0, sizeof(from));
598: if (packet_connection_is_on_socket()) {
599: fromlen = sizeof(from);
600: if (getpeername(packet_get_connection_in(),
1.42.2.8! brad 601: (struct sockaddr *) & from, &fromlen) < 0) {
1.24 markus 602: debug("getpeername: %.100s", strerror(errno));
603: fatal_cleanup();
604: }
605: }
1.25 markus 606:
1.35 markus 607: /* Get the time and hostname when the user last logged in. */
1.42.2.4 jason 608: if (options.print_lastlog) {
609: hostname[0] = '\0';
610: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
611: hostname, sizeof(hostname));
612: }
1.35 markus 613:
1.24 markus 614: /* Record that there was a login on that tty from the remote host. */
615: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.42.2.8! brad 616: get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping),
1.42.2.4 jason 617: (struct sockaddr *)&from);
1.24 markus 618:
1.42.2.4 jason 619: if (check_quietlogin(s, command))
1.24 markus 620: return;
1.42.2.4 jason 621:
622: if (options.print_lastlog && last_login_time != 0) {
1.24 markus 623: time_string = ctime(&last_login_time);
624: if (strchr(time_string, '\n'))
625: *strchr(time_string, '\n') = 0;
1.40 markus 626: if (strcmp(hostname, "") == 0)
1.24 markus 627: printf("Last login: %s\r\n", time_string);
628: else
1.36 markus 629: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 630: }
1.42.2.4 jason 631:
632: do_motd();
633: }
634:
635: /*
636: * Display the message of the day.
637: */
638: void
639: do_motd(void)
640: {
641: FILE *f;
642: char buf[256];
643:
1.24 markus 644: if (options.print_motd) {
1.28 millert 645: #ifdef HAVE_LOGIN_CAP
646: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
647: "/etc/motd"), "r");
648: #else
1.24 markus 649: f = fopen("/etc/motd", "r");
1.28 millert 650: #endif
1.24 markus 651: if (f) {
652: while (fgets(buf, sizeof(buf), f))
653: fputs(buf, stdout);
654: fclose(f);
655: }
1.2 markus 656: }
1.1 markus 657: }
658:
1.42.2.4 jason 659:
660: /*
661: * Check for quiet login, either .hushlogin or command given.
662: */
663: int
664: check_quietlogin(Session *s, const char *command)
665: {
666: char buf[256];
1.42.2.6 miod 667: struct passwd *pw = s->pw;
1.42.2.4 jason 668: struct stat st;
669:
670: /* Return 1 if .hushlogin exists or a command given. */
671: if (command != NULL)
672: return 1;
673: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
674: #ifdef HAVE_LOGIN_CAP
675: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
676: return 1;
677: #else
678: if (stat(buf, &st) >= 0)
679: return 1;
680: #endif
681: return 0;
682: }
683:
1.1 markus 684: /*
685: * Sets the value of the given variable in the environment. If the variable
686: * already exists, its value is overriden.
687: */
1.42.2.6 miod 688: static void
1.42.2.1 jason 689: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.42.2.8! brad 690: const char *value)
1.1 markus 691: {
1.42.2.1 jason 692: u_int i, namelen;
1.1 markus 693: char **env;
694:
695: /*
696: * Find the slot where the value should be stored. If the variable
697: * already exists, we reuse the slot; otherwise we append a new slot
698: * at the end of the array, expanding if necessary.
699: */
700: env = *envp;
701: namelen = strlen(name);
702: for (i = 0; env[i]; i++)
703: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
704: break;
705: if (env[i]) {
706: /* Reuse the slot. */
707: xfree(env[i]);
708: } else {
709: /* New variable. Expand if necessary. */
710: if (i >= (*envsizep) - 1) {
711: (*envsizep) += 50;
712: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
713: }
714: /* Need to set the NULL pointer at end of array beyond the new slot. */
715: env[i + 1] = NULL;
716: }
717:
718: /* Allocate space and format the variable in the appropriate slot. */
719: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
720: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
721: }
722:
723: /*
724: * Reads environment variables from the given file and adds/overrides them
725: * into the environment. If the file does not exist, this does nothing.
726: * Otherwise, it must consist of empty lines, comments (line starts with '#')
727: * and assignments of the form name=value. No other forms are allowed.
728: */
1.42.2.6 miod 729: static void
1.42.2.1 jason 730: read_environment_file(char ***env, u_int *envsize,
1.42.2.8! brad 731: const char *filename)
1.1 markus 732: {
733: FILE *f;
734: char buf[4096];
735: char *cp, *value;
736:
737: f = fopen(filename, "r");
738: if (!f)
739: return;
740:
741: while (fgets(buf, sizeof(buf), f)) {
742: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
743: ;
744: if (!*cp || *cp == '#' || *cp == '\n')
745: continue;
746: if (strchr(cp, '\n'))
747: *strchr(cp, '\n') = '\0';
748: value = strchr(cp, '=');
749: if (value == NULL) {
750: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
751: continue;
752: }
1.14 deraadt 753: /*
754: * Replace the equals sign by nul, and advance value to
755: * the value string.
756: */
1.1 markus 757: *value = '\0';
758: value++;
759: child_set_env(env, envsize, cp, value);
760: }
761: fclose(f);
762: }
763:
1.42.2.8! brad 764: static char **
! 765: do_setup_env(Session *s, const char *shell)
1.1 markus 766: {
767: char buf[256];
1.42.2.8! brad 768: u_int i, envsize;
1.1 markus 769: char **env;
1.42.2.8! brad 770: struct passwd *pw = s->pw;
1.1 markus 771:
772: /* Initialize the environment. */
773: envsize = 100;
774: env = xmalloc(envsize * sizeof(char *));
775: env[0] = NULL;
776:
777: if (!options.use_login) {
778: /* Set basic environment. */
779: child_set_env(&env, &envsize, "USER", pw->pw_name);
780: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
781: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 782: #ifdef HAVE_LOGIN_CAP
1.29 millert 783: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
784: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 785: #else
1.29 millert 786: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 787: #endif
1.1 markus 788:
789: snprintf(buf, sizeof buf, "%.200s/%.50s",
790: _PATH_MAILDIR, pw->pw_name);
791: child_set_env(&env, &envsize, "MAIL", buf);
792:
793: /* Normal systems set SHELL by default. */
794: child_set_env(&env, &envsize, "SHELL", shell);
795: }
796: if (getenv("TZ"))
797: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
798:
799: /* Set custom environment options from RSA authentication. */
1.42.2.8! brad 800: if (!options.use_login) {
! 801: while (custom_environment) {
! 802: struct envstring *ce = custom_environment;
! 803: char *s = ce->s;
! 804:
! 805: for (i = 0; s[i] != '=' && s[i]; i++)
! 806: ;
! 807: if (s[i] == '=') {
! 808: s[i] = 0;
! 809: child_set_env(&env, &envsize, s, s + i + 1);
! 810: }
! 811: custom_environment = ce->next;
! 812: xfree(ce->s);
! 813: xfree(ce);
1.1 markus 814: }
815: }
816:
817: snprintf(buf, sizeof buf, "%.50s %d %d",
1.42.2.8! brad 818: get_remote_ipaddr(), get_remote_port(), get_local_port());
1.1 markus 819: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
820:
1.42.2.3 jason 821: if (s->ttyfd != -1)
822: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
823: if (s->term)
824: child_set_env(&env, &envsize, "TERM", s->term);
825: if (s->display)
826: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 827: if (original_command)
828: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
829: original_command);
1.1 markus 830: #ifdef KRB4
1.42.2.6 miod 831: if (s->authctxt->krb4_ticket_file)
832: child_set_env(&env, &envsize, "KRBTKFILE",
1.42.2.8! brad 833: s->authctxt->krb4_ticket_file);
1.42.2.6 miod 834: #endif
835: #ifdef KRB5
836: if (s->authctxt->krb5_ticket_file)
837: child_set_env(&env, &envsize, "KRB5CCNAME",
1.42.2.8! brad 838: s->authctxt->krb5_ticket_file);
1.42.2.6 miod 839: #endif
1.1 markus 840: if (auth_get_socket_name() != NULL)
841: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1.42.2.8! brad 842: auth_get_socket_name());
1.1 markus 843:
844: /* read $HOME/.ssh/environment. */
845: if (!options.use_login) {
1.14 deraadt 846: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
847: pw->pw_dir);
1.1 markus 848: read_environment_file(&env, &envsize, buf);
849: }
850: if (debug_flag) {
851: /* dump the environment */
852: fprintf(stderr, "Environment:\n");
853: for (i = 0; env[i]; i++)
854: fprintf(stderr, " %.200s\n", env[i]);
855: }
1.42.2.8! brad 856: return env;
! 857: }
! 858:
! 859: /*
! 860: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found
! 861: * first in this order).
! 862: */
! 863: static void
! 864: do_rc_files(Session *s, const char *shell)
! 865: {
! 866: FILE *f = NULL;
! 867: char cmd[1024];
! 868: int do_xauth;
! 869: struct stat st;
! 870:
! 871: do_xauth =
! 872: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
! 873:
! 874: /* ignore _PATH_SSH_USER_RC for subsystems */
! 875: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
! 876: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
! 877: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
! 878: if (debug_flag)
! 879: fprintf(stderr, "Running %s\n", cmd);
! 880: f = popen(cmd, "w");
! 881: if (f) {
! 882: if (do_xauth)
! 883: fprintf(f, "%s %s\n", s->auth_proto,
! 884: s->auth_data);
! 885: pclose(f);
! 886: } else
! 887: fprintf(stderr, "Could not run %s\n",
! 888: _PATH_SSH_USER_RC);
! 889: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
! 890: if (debug_flag)
! 891: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
! 892: _PATH_SSH_SYSTEM_RC);
! 893: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
! 894: if (f) {
! 895: if (do_xauth)
! 896: fprintf(f, "%s %s\n", s->auth_proto,
! 897: s->auth_data);
! 898: pclose(f);
! 899: } else
! 900: fprintf(stderr, "Could not run %s\n",
! 901: _PATH_SSH_SYSTEM_RC);
! 902: } else if (do_xauth && options.xauth_location != NULL) {
! 903: /* Add authority data to .Xauthority if appropriate. */
! 904: if (debug_flag) {
! 905: fprintf(stderr,
! 906: "Running %.100s add "
! 907: "%.100s %.100s %.100s\n",
! 908: options.xauth_location, s->auth_display,
! 909: s->auth_proto, s->auth_data);
! 910: }
! 911: snprintf(cmd, sizeof cmd, "%s -q -",
! 912: options.xauth_location);
! 913: f = popen(cmd, "w");
! 914: if (f) {
! 915: fprintf(f, "add %s %s %s\n",
! 916: s->auth_display, s->auth_proto,
! 917: s->auth_data);
! 918: pclose(f);
! 919: } else {
! 920: fprintf(stderr, "Could not run %s\n",
! 921: cmd);
! 922: }
! 923: }
! 924: }
! 925:
! 926: static void
! 927: do_nologin(struct passwd *pw)
! 928: {
! 929: FILE *f = NULL;
! 930: char buf[1024];
! 931:
! 932: #ifdef HAVE_LOGIN_CAP
! 933: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
! 934: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
! 935: _PATH_NOLOGIN), "r");
! 936: #else
! 937: if (pw->pw_uid)
! 938: f = fopen(_PATH_NOLOGIN, "r");
! 939: #endif
! 940: if (f) {
! 941: /* /etc/nologin exists. Print its contents and exit. */
! 942: while (fgets(buf, sizeof(buf), f))
! 943: fputs(buf, stderr);
! 944: fclose(f);
! 945: exit(254);
! 946: }
! 947: }
! 948:
! 949: /* Set login name, uid, gid, and groups. */
! 950: static void
! 951: do_setusercontext(struct passwd *pw)
! 952: {
! 953: if (getuid() == 0 || geteuid() == 0) {
! 954: #ifdef HAVE_LOGIN_CAP
! 955: if (setusercontext(lc, pw, pw->pw_uid,
! 956: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
! 957: perror("unable to set user context");
! 958: exit(1);
! 959: }
! 960: #else
! 961: if (setlogin(pw->pw_name) < 0)
! 962: error("setlogin failed: %s", strerror(errno));
! 963: if (setgid(pw->pw_gid) < 0) {
! 964: perror("setgid");
! 965: exit(1);
! 966: }
! 967: /* Initialize the group list. */
! 968: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
! 969: perror("initgroups");
! 970: exit(1);
! 971: }
! 972: endgrent();
! 973:
! 974: /* Permanently switch to the desired uid. */
! 975: permanently_set_uid(pw);
! 976: #endif
! 977: }
! 978: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
! 979: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
! 980: }
! 981:
! 982: /*
! 983: * Performs common processing for the child, such as setting up the
! 984: * environment, closing extra file descriptors, setting the user and group
! 985: * ids, and executing the command or shell.
! 986: */
! 987: void
! 988: do_child(Session *s, const char *command)
! 989: {
! 990: extern char **environ;
! 991: char **env;
! 992: char *argv[10];
! 993: const char *shell, *shell0, *hostname = NULL;
! 994: struct passwd *pw = s->pw;
! 995: u_int i;
! 996:
! 997: /* remove hostkey from the child's memory */
! 998: destroy_sensitive_data();
! 999:
! 1000: /* login(1) is only called if we execute the login shell */
! 1001: if (options.use_login && command != NULL)
! 1002: options.use_login = 0;
! 1003:
! 1004: /*
! 1005: * Login(1) does this as well, and it needs uid 0 for the "-h"
! 1006: * switch, so we let login(1) to this for us.
! 1007: */
! 1008: if (!options.use_login) {
! 1009: do_nologin(pw);
! 1010: do_setusercontext(pw);
! 1011: }
! 1012:
! 1013: /*
! 1014: * Get the shell from the password data. An empty shell field is
! 1015: * legal, and means /bin/sh.
! 1016: */
! 1017: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
! 1018: #ifdef HAVE_LOGIN_CAP
! 1019: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
! 1020: #endif
! 1021:
! 1022: env = do_setup_env(s, shell);
! 1023:
1.26 millert 1024: /* we have to stash the hostname before we close our socket. */
1025: if (options.use_login)
1.42.2.4 jason 1026: hostname = get_remote_name_or_ip(utmp_len,
1.42.2.8! brad 1027: options.verify_reverse_mapping);
1.1 markus 1028: /*
1029: * Close the connection descriptors; note that this is the child, and
1030: * the server will still have the socket open, and it is important
1031: * that we do not shutdown it. Note that the descriptors cannot be
1032: * closed before building the environment, as we call
1033: * get_remote_ipaddr there.
1034: */
1035: if (packet_get_connection_in() == packet_get_connection_out())
1036: close(packet_get_connection_in());
1037: else {
1038: close(packet_get_connection_in());
1039: close(packet_get_connection_out());
1040: }
1041: /*
1042: * Close all descriptors related to channels. They will still remain
1043: * open in the parent.
1044: */
1045: /* XXX better use close-on-exec? -markus */
1046: channel_close_all();
1047:
1048: /*
1049: * Close any extra file descriptors. Note that there may still be
1050: * descriptors left by system functions. They will be closed later.
1051: */
1052: endpwent();
1053:
1054: /*
1055: * Close any extra open file descriptors so that we don\'t have them
1056: * hanging around in clients. Note that we want to do this after
1057: * initgroups, because at least on Solaris 2.3 it leaves file
1058: * descriptors open.
1059: */
1060: for (i = 3; i < 64; i++)
1061: close(i);
1062:
1063: /*
1.42.2.8! brad 1064: * Must take new environment into use so that .ssh/rc,
! 1065: * /etc/sshrc and xauth are run in the proper environment.
1.1 markus 1066: */
1067: environ = env;
1068:
1.42.2.6 miod 1069: #ifdef AFS
1070: /* Try to get AFS tokens for the local cell. */
1071: if (k_hasafs()) {
1072: char cell[64];
1.42.2.8! brad 1073:
1.42.2.6 miod 1074: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1075: krb_afslog(cell, 0);
1.42.2.8! brad 1076:
1.42.2.6 miod 1077: krb_afslog(0, 0);
1078: }
1079: #endif /* AFS */
1080:
1.42.2.7 miod 1081: /* Change current directory to the user\'s home directory. */
1082: if (chdir(pw->pw_dir) < 0) {
1083: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1084: pw->pw_dir, strerror(errno));
1085: #ifdef HAVE_LOGIN_CAP
1086: if (login_getcapbool(lc, "requirehome", 0))
1087: exit(1);
1088: #endif
1089: }
1090:
1.42.2.8! brad 1091: if (!options.use_login)
! 1092: do_rc_files(s, shell);
1.42.2.4 jason 1093:
1094: /* restore SIGPIPE for child */
1095: signal(SIGPIPE, SIG_DFL);
1096:
1.42.2.8! brad 1097: if (options.use_login) {
! 1098: /* Launch login(1). */
! 1099:
! 1100: execl("/usr/bin/login", "login", "-h", hostname,
! 1101: "-p", "-f", "--", pw->pw_name, (char *)NULL);
! 1102:
! 1103: /* Login couldn't be executed, die. */
! 1104:
! 1105: perror("login");
! 1106: exit(1);
! 1107: }
! 1108:
! 1109: /* Get the last component of the shell name. */
! 1110: if ((shell0 = strrchr(shell, '/')) != NULL)
! 1111: shell0++;
! 1112: else
! 1113: shell0 = shell;
! 1114:
1.1 markus 1115: /*
1116: * If we have no command, execute the shell. In this case, the shell
1117: * name to be passed in argv[0] is preceded by '-' to indicate that
1118: * this is a login shell.
1119: */
1120: if (!command) {
1.42.2.8! brad 1121: char argv0[256];
1.1 markus 1122:
1.42.2.8! brad 1123: /* Start the shell. Set initial character to '-'. */
! 1124: argv0[0] = '-';
1.1 markus 1125:
1.42.2.8! brad 1126: if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
! 1127: >= sizeof(argv0) - 1) {
! 1128: errno = EINVAL;
1.1 markus 1129: perror(shell);
1130: exit(1);
1131: }
1.42.2.8! brad 1132:
! 1133: /* Execute the shell. */
! 1134: argv[0] = argv0;
! 1135: argv[1] = NULL;
! 1136: execve(shell, argv, env);
! 1137:
! 1138: /* Executing the shell failed. */
! 1139: perror(shell);
! 1140: exit(1);
1.1 markus 1141: }
1142: /*
1143: * Execute the command using the user's shell. This uses the -c
1144: * option to execute the command.
1145: */
1.42.2.8! brad 1146: argv[0] = (char *) shell0;
1.1 markus 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");
1.42.2.8! brad 1162: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1163: sessions[i].used = 0;
1164: }
1165: did_init = 1;
1166: }
1.42.2.8! brad 1167: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1168: Session *s = &sessions[i];
1169: if (! s->used) {
1.42.2.4 jason 1170: memset(s, 0, sizeof(*s));
1.1 markus 1171: s->chanid = -1;
1172: s->ptyfd = -1;
1173: s->ttyfd = -1;
1174: s->used = 1;
1.42.2.6 miod 1175: s->self = i;
1.1 markus 1176: debug("session_new: session %d", i);
1177: return s;
1178: }
1179: }
1180: return NULL;
1181: }
1182:
1.42.2.6 miod 1183: static void
1.1 markus 1184: session_dump(void)
1185: {
1186: int i;
1.42.2.8! brad 1187: for (i = 0; i < MAX_SESSIONS; i++) {
1.1 markus 1188: Session *s = &sessions[i];
1189: debug("dump: used %d session %d %p channel %d pid %d",
1190: s->used,
1191: s->self,
1192: s,
1193: s->chanid,
1194: s->pid);
1195: }
1196: }
1197:
1.2 markus 1198: int
1.42.2.6 miod 1199: session_open(Authctxt *authctxt, int chanid)
1.2 markus 1200: {
1201: Session *s = session_new();
1202: debug("session_open: channel %d", chanid);
1203: if (s == NULL) {
1204: error("no more sessions");
1205: return 0;
1206: }
1.42.2.6 miod 1207: s->authctxt = authctxt;
1208: s->pw = authctxt->pw;
1.7 markus 1209: if (s->pw == NULL)
1.42.2.1 jason 1210: fatal("no user for session %d", s->self);
1.2 markus 1211: debug("session_open: session %d: link with channel %d", s->self, chanid);
1212: s->chanid = chanid;
1213: return 1;
1214: }
1215:
1.42.2.6 miod 1216: static Session *
1.2 markus 1217: session_by_channel(int id)
1218: {
1219: int i;
1.42.2.8! brad 1220: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1221: Session *s = &sessions[i];
1222: if (s->used && s->chanid == id) {
1223: debug("session_by_channel: session %d channel %d", i, id);
1224: return s;
1225: }
1226: }
1227: debug("session_by_channel: unknown channel %d", id);
1228: session_dump();
1229: return NULL;
1230: }
1231:
1.42.2.6 miod 1232: static Session *
1.2 markus 1233: session_by_pid(pid_t pid)
1234: {
1235: int i;
1236: debug("session_by_pid: pid %d", pid);
1.42.2.8! brad 1237: for (i = 0; i < MAX_SESSIONS; i++) {
1.2 markus 1238: Session *s = &sessions[i];
1239: if (s->used && s->pid == pid)
1240: return s;
1241: }
1242: error("session_by_pid: unknown pid %d", pid);
1243: session_dump();
1244: return NULL;
1245: }
1246:
1.42.2.6 miod 1247: static int
1.2 markus 1248: session_window_change_req(Session *s)
1249: {
1250: s->col = packet_get_int();
1251: s->row = packet_get_int();
1252: s->xpixel = packet_get_int();
1253: s->ypixel = packet_get_int();
1.42.2.8! brad 1254: packet_check_eom();
1.2 markus 1255: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1256: return 1;
1257: }
1258:
1.42.2.6 miod 1259: static int
1.2 markus 1260: session_pty_req(Session *s)
1261: {
1.42.2.1 jason 1262: u_int len;
1.42.2.4 jason 1263: int n_bytes;
1.2 markus 1264:
1.42.2.6 miod 1265: if (no_pty_flag) {
1266: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1267: return 0;
1.42.2.6 miod 1268: }
1269: if (s->ttyfd != -1) {
1270: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1271: return 0;
1.42.2.6 miod 1272: }
1273:
1.2 markus 1274: s->term = packet_get_string(&len);
1.42.2.6 miod 1275:
1276: if (compat20) {
1277: s->col = packet_get_int();
1278: s->row = packet_get_int();
1279: } else {
1280: s->row = packet_get_int();
1281: s->col = packet_get_int();
1282: }
1.2 markus 1283: s->xpixel = packet_get_int();
1284: s->ypixel = packet_get_int();
1285:
1286: if (strcmp(s->term, "") == 0) {
1287: xfree(s->term);
1288: s->term = NULL;
1289: }
1.42.2.6 miod 1290:
1.2 markus 1291: /* Allocate a pty and open it. */
1.42.2.6 miod 1292: debug("Allocating pty.");
1.2 markus 1293: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1.42.2.6 miod 1294: if (s->term)
1295: xfree(s->term);
1.2 markus 1296: s->term = NULL;
1297: s->ptyfd = -1;
1298: s->ttyfd = -1;
1299: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1300: return 0;
1.2 markus 1301: }
1302: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.42.2.6 miod 1303:
1304: /* for SSH1 the tty modes length is not given */
1305: if (!compat20)
1306: n_bytes = packet_remaining();
1307: tty_parse_modes(s->ttyfd, &n_bytes);
1308:
1.2 markus 1309: /*
1310: * Add a cleanup function to clear the utmp entry and record logout
1311: * time in case we call fatal() (e.g., the connection gets closed).
1312: */
1.42.2.6 miod 1313: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.2 markus 1314: pty_setowner(s->pw, s->tty);
1.42.2.6 miod 1315:
1316: /* Set window size from the packet. */
1.2 markus 1317: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1318:
1.42.2.8! brad 1319: packet_check_eom();
1.9 markus 1320: session_proctitle(s);
1.2 markus 1321: return 1;
1322: }
1323:
1.42.2.6 miod 1324: static int
1.7 markus 1325: session_subsystem_req(Session *s)
1326: {
1.42.2.7 miod 1327: struct stat st;
1.42.2.1 jason 1328: u_int len;
1.7 markus 1329: int success = 0;
1.42.2.7 miod 1330: char *cmd, *subsys = packet_get_string(&len);
1.18 jakob 1331: int i;
1.7 markus 1332:
1.42.2.8! brad 1333: packet_check_eom();
! 1334: log("subsystem request for %.100s", subsys);
1.18 jakob 1335:
1336: for (i = 0; i < options.num_subsystems; i++) {
1.42.2.7 miod 1337: if (strcmp(subsys, options.subsystem_name[i]) == 0) {
1338: cmd = options.subsystem_command[i];
1339: if (stat(cmd, &st) < 0) {
1340: error("subsystem: cannot stat %s: %s", cmd,
1341: strerror(errno));
1342: break;
1343: }
1344: debug("subsystem: exec() %s", cmd);
1.42.2.4 jason 1345: s->is_subsystem = 1;
1.42.2.7 miod 1346: do_exec(s, cmd);
1.18 jakob 1347: success = 1;
1.42.2.8! brad 1348: break;
1.18 jakob 1349: }
1350: }
1351:
1352: if (!success)
1.42.2.8! brad 1353: log("subsystem request for %.100s failed, subsystem not found",
1.42.2.7 miod 1354: subsys);
1.7 markus 1355:
1356: xfree(subsys);
1357: return success;
1358: }
1359:
1.42.2.6 miod 1360: static int
1.7 markus 1361: session_x11_req(Session *s)
1362: {
1.42.2.6 miod 1363: int success;
1.7 markus 1364:
1365: s->single_connection = packet_get_char();
1366: s->auth_proto = packet_get_string(NULL);
1367: s->auth_data = packet_get_string(NULL);
1368: s->screen = packet_get_int();
1.42.2.8! brad 1369: packet_check_eom();
1.7 markus 1370:
1.42.2.6 miod 1371: success = session_setup_x11fwd(s);
1372: if (!success) {
1.7 markus 1373: xfree(s->auth_proto);
1374: xfree(s->auth_data);
1.42.2.6 miod 1375: s->auth_proto = NULL;
1376: s->auth_data = NULL;
1.7 markus 1377: }
1.42.2.6 miod 1378: return success;
1.7 markus 1379: }
1380:
1.42.2.6 miod 1381: static int
1.19 markus 1382: session_shell_req(Session *s)
1383: {
1.42.2.8! brad 1384: packet_check_eom();
1.42.2.6 miod 1385: do_exec(s, NULL);
1.19 markus 1386: return 1;
1387: }
1388:
1.42.2.6 miod 1389: static int
1.19 markus 1390: session_exec_req(Session *s)
1391: {
1.42.2.1 jason 1392: u_int len;
1.19 markus 1393: char *command = packet_get_string(&len);
1.42.2.8! brad 1394: packet_check_eom();
1.42.2.6 miod 1395: do_exec(s, command);
1396: xfree(command);
1.19 markus 1397: return 1;
1398: }
1399:
1.42.2.6 miod 1400: static int
1.42.2.1 jason 1401: session_auth_agent_req(Session *s)
1402: {
1403: static int called = 0;
1.42.2.8! brad 1404: packet_check_eom();
1.42.2.1 jason 1405: if (no_agent_forwarding_flag) {
1406: debug("session_auth_agent_req: no_agent_forwarding_flag");
1407: return 0;
1408: }
1409: if (called) {
1410: return 0;
1411: } else {
1412: called = 1;
1413: return auth_input_request_forwarding(s->pw);
1414: }
1415: }
1416:
1.42.2.8! brad 1417: int
! 1418: session_input_channel_req(Channel *c, const char *rtype)
1.2 markus 1419: {
1420: int success = 0;
1421: Session *s;
1422:
1.42.2.8! brad 1423: if ((s = session_by_channel(c->self)) == NULL) {
! 1424: log("session_input_channel_req: no session %d req %.100s",
! 1425: c->self, rtype);
! 1426: return 0;
! 1427: }
! 1428: debug("session_input_channel_req: session %d req %s", s->self, rtype);
1.2 markus 1429:
1430: /*
1.42.2.4 jason 1431: * a session is in LARVAL state until a shell, a command
1432: * or a subsystem is executed
1.2 markus 1433: */
1434: if (c->type == SSH_CHANNEL_LARVAL) {
1435: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1436: success = session_shell_req(s);
1.2 markus 1437: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1438: success = session_exec_req(s);
1.2 markus 1439: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1440: success = session_pty_req(s);
1.7 markus 1441: } else if (strcmp(rtype, "x11-req") == 0) {
1442: success = session_x11_req(s);
1.42.2.1 jason 1443: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1444: success = session_auth_agent_req(s);
1.7 markus 1445: } else if (strcmp(rtype, "subsystem") == 0) {
1446: success = session_subsystem_req(s);
1.2 markus 1447: }
1448: }
1449: if (strcmp(rtype, "window-change") == 0) {
1450: success = session_window_change_req(s);
1451: }
1.42.2.8! brad 1452: return success;
1.2 markus 1453: }
1454:
1455: void
1456: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1457: {
1458: if (!compat20)
1459: fatal("session_set_fds: called for proto != 2.0");
1460: /*
1461: * now that have a child and a pipe to the child,
1462: * we can activate our channel and register the fd's
1463: */
1464: if (s->chanid == -1)
1465: fatal("no channel for session %d", s->self);
1466: channel_set_fds(s->chanid,
1467: fdout, fdin, fderr,
1.42 markus 1468: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1.42.2.8! brad 1469: 1,
! 1470: CHAN_SES_WINDOW_DEFAULT);
1.2 markus 1471: }
1472:
1.42.2.6 miod 1473: /*
1474: * Function to perform pty cleanup. Also called if we get aborted abnormally
1475: * (e.g., due to a dropped connection).
1476: */
1477: static void
1478: session_pty_cleanup(void *session)
1.1 markus 1479: {
1.42.2.6 miod 1480: Session *s = session;
1481:
1482: if (s == NULL) {
1483: error("session_pty_cleanup: no session");
1484: return;
1485: }
1486: if (s->ttyfd == -1)
1.1 markus 1487: return;
1488:
1.42.2.1 jason 1489: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1490:
1491: /* Record that the user has logged out. */
1.42.2.6 miod 1492: if (s->pid != 0)
1493: record_logout(s->pid, s->tty);
1.1 markus 1494:
1495: /* Release the pseudo-tty. */
1496: pty_release(s->tty);
1497:
1498: /*
1499: * Close the server side of the socket pairs. We must do this after
1500: * the pty cleanup, so that another process doesn't get this pty
1501: * while we're still cleaning up.
1502: */
1503: if (close(s->ptymaster) < 0)
1504: error("close(s->ptymaster): %s", strerror(errno));
1.42.2.7 miod 1505:
1506: /* unlink pty from session */
1507: s->ttyfd = -1;
1.2 markus 1508: }
1509:
1.42.2.6 miod 1510: static void
1.2 markus 1511: session_exit_message(Session *s, int status)
1512: {
1513: Channel *c;
1.42.2.8! brad 1514:
! 1515: if ((c = channel_lookup(s->chanid)) == NULL)
1.42.2.6 miod 1516: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1517: s->self, s->chanid);
1518: debug("session_exit_message: session %d channel %d pid %d",
1519: s->self, s->chanid, s->pid);
1520:
1521: if (WIFEXITED(status)) {
1.42.2.8! brad 1522: channel_request_start(s->chanid, "exit-status", 0);
1.2 markus 1523: packet_put_int(WEXITSTATUS(status));
1524: packet_send();
1525: } else if (WIFSIGNALED(status)) {
1.42.2.8! brad 1526: channel_request_start(s->chanid, "exit-signal", 0);
1.2 markus 1527: packet_put_int(WTERMSIG(status));
1528: packet_put_char(WCOREDUMP(status));
1529: packet_put_cstring("");
1530: packet_put_cstring("");
1531: packet_send();
1532: } else {
1533: /* Some weird exit cause. Just exit. */
1534: packet_disconnect("wait returned status %04x.", status);
1535: }
1536:
1537: /* disconnect channel */
1538: debug("session_exit_message: release channel %d", s->chanid);
1539: channel_cancel_cleanup(s->chanid);
1.5 markus 1540: /*
1541: * emulate a write failure with 'chan_write_failed', nobody will be
1542: * interested in data we write.
1543: * Note that we must not call 'chan_read_failed', since there could
1544: * be some more data waiting in the pipe.
1545: */
1.8 markus 1546: if (c->ostate != CHAN_OUTPUT_CLOSED)
1547: chan_write_failed(c);
1.2 markus 1548: s->chanid = -1;
1549: }
1550:
1.42.2.6 miod 1551: static void
1552: session_close(Session *s)
1.2 markus 1553: {
1.42.2.6 miod 1554: debug("session_close: session %d pid %d", s->self, s->pid);
1555: if (s->ttyfd != -1) {
1556: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1557: session_pty_cleanup(s);
1558: }
1.2 markus 1559: if (s->term)
1560: xfree(s->term);
1561: if (s->display)
1562: xfree(s->display);
1.42.2.8! brad 1563: if (s->auth_display)
! 1564: xfree(s->auth_display);
1.2 markus 1565: if (s->auth_data)
1566: xfree(s->auth_data);
1567: if (s->auth_proto)
1568: xfree(s->auth_proto);
1569: s->used = 0;
1.9 markus 1570: session_proctitle(s);
1.2 markus 1571: }
1572:
1573: void
1574: session_close_by_pid(pid_t pid, int status)
1575: {
1576: Session *s = session_by_pid(pid);
1577: if (s == NULL) {
1.42.2.6 miod 1578: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1579: return;
1580: }
1581: if (s->chanid != -1)
1582: session_exit_message(s, status);
1583: session_close(s);
1584: }
1585:
1586: /*
1587: * this is called when a channel dies before
1588: * the session 'child' itself dies
1589: */
1590: void
1591: session_close_by_channel(int id, void *arg)
1592: {
1593: Session *s = session_by_channel(id);
1594: if (s == NULL) {
1.42.2.7 miod 1595: debug("session_close_by_channel: no session for id %d", id);
1.2 markus 1596: return;
1597: }
1.42.2.7 miod 1598: debug("session_close_by_channel: channel %d child %d", id, s->pid);
1599: if (s->pid != 0) {
1600: debug("session_close_by_channel: channel %d: has child", id);
1601: /*
1602: * delay detach of session, but release pty, since
1603: * the fd's to the child are already closed
1604: */
1605: if (s->ttyfd != -1) {
1606: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1607: session_pty_cleanup(s);
1608: }
1609: return;
1610: }
1611: /* detach by removing callback */
1.2 markus 1612: channel_cancel_cleanup(s->chanid);
1613: s->chanid = -1;
1.42.2.7 miod 1614: session_close(s);
1615: }
1.2 markus 1616:
1.42.2.7 miod 1617: void
1618: session_destroy_all(void)
1619: {
1620: int i;
1.42.2.8! brad 1621: for (i = 0; i < MAX_SESSIONS; i++) {
1.42.2.7 miod 1622: Session *s = &sessions[i];
1.42.2.8! brad 1623: if (s->used)
1.42.2.7 miod 1624: session_close(s);
1.2 markus 1625: }
1.9 markus 1626: }
1627:
1.42.2.6 miod 1628: static char *
1.9 markus 1629: session_tty_list(void)
1630: {
1631: static char buf[1024];
1632: int i;
1633: buf[0] = '\0';
1.42.2.8! brad 1634: for (i = 0; i < MAX_SESSIONS; i++) {
1.9 markus 1635: Session *s = &sessions[i];
1636: if (s->used && s->ttyfd != -1) {
1637: if (buf[0] != '\0')
1638: strlcat(buf, ",", sizeof buf);
1639: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1640: }
1641: }
1642: if (buf[0] == '\0')
1643: strlcpy(buf, "notty", sizeof buf);
1644: return buf;
1645: }
1646:
1647: void
1648: session_proctitle(Session *s)
1649: {
1650: if (s->pw == NULL)
1651: error("no user for session %d", s->self);
1652: else
1653: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.2 markus 1654: }
1655:
1.42.2.6 miod 1656: int
1657: session_setup_x11fwd(Session *s)
1.2 markus 1658: {
1.42.2.6 miod 1659: struct stat st;
1.42.2.8! brad 1660: char display[512], auth_display[512];
! 1661: char hostname[MAXHOSTNAMELEN];
1.42.2.4 jason 1662:
1.42.2.6 miod 1663: if (no_x11_forwarding_flag) {
1664: packet_send_debug("X11 forwarding disabled in user configuration file.");
1665: return 0;
1666: }
1667: if (!options.x11_forwarding) {
1668: debug("X11 forwarding disabled in server configuration file.");
1669: return 0;
1670: }
1671: if (!options.xauth_location ||
1672: (stat(options.xauth_location, &st) == -1)) {
1673: packet_send_debug("No xauth program; cannot forward with spoofing.");
1674: return 0;
1675: }
1676: if (options.use_login) {
1677: packet_send_debug("X11 forwarding disabled; "
1678: "not compatible with UseLogin=yes.");
1679: return 0;
1680: }
1681: if (s->display != NULL) {
1682: debug("X11 display already set.");
1683: return 0;
1684: }
1.42.2.8! brad 1685: s->display_number = x11_create_display_inet(options.x11_display_offset,
! 1686: options.x11_use_localhost, s->single_connection);
! 1687: if (s->display_number == -1) {
1.42.2.6 miod 1688: debug("x11_create_display_inet failed.");
1689: return 0;
1690: }
1.42.2.8! brad 1691:
! 1692: /* Set up a suitable value for the DISPLAY variable. */
! 1693: if (gethostname(hostname, sizeof(hostname)) < 0)
! 1694: fatal("gethostname: %.100s", strerror(errno));
! 1695: /*
! 1696: * auth_display must be used as the displayname when the
! 1697: * authorization entry is added with xauth(1). This will be
! 1698: * different than the DISPLAY string for localhost displays.
! 1699: */
! 1700: if (options.x11_use_localhost) {
! 1701: snprintf(display, sizeof display, "localhost:%d.%d",
! 1702: s->display_number, s->screen);
! 1703: snprintf(auth_display, sizeof auth_display, "unix:%d.%d",
! 1704: s->display_number, s->screen);
! 1705: s->display = xstrdup(display);
! 1706: s->auth_display = xstrdup(auth_display);
! 1707: } else {
! 1708: snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
! 1709: s->display_number, s->screen);
! 1710: s->display = xstrdup(display);
! 1711: s->auth_display = xstrdup(display);
! 1712: }
! 1713:
1.42.2.6 miod 1714: return 1;
1715: }
1716:
1717: static void
1718: do_authenticated2(Authctxt *authctxt)
1719: {
1720: server_loop2(authctxt);
1.1 markus 1721: }
![[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