Annotation of src/usr.bin/ssh/session.c, Revision 1.90
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"
1.90 ! markus 36: RCSID("$OpenBSD: session.c,v 1.89 2001/06/13 09:10:31 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);
1.85 markus 89: void session_pty_cleanup(void *session);
1.86 markus 90: int session_pty_req(Session *s);
1.9 markus 91: void session_proctitle(Session *s);
1.81 markus 92: int session_setup_x11fwd(Session *s);
1.82 markus 93: void session_close(Session *s);
1.63 markus 94: void do_exec_pty(Session *s, const char *command);
95: void do_exec_no_pty(Session *s, const char *command);
1.90 ! markus 96: void do_exec(Session *s, const char *command);
1.41 markus 97: void do_login(Session *s, const char *command);
1.60 markus 98: void do_child(Session *s, const char *command);
1.73 djm 99: void do_motd(void);
100: int check_quietlogin(Session *s, const char *command);
1.1 markus 101:
1.65 markus 102: void do_authenticated1(Authctxt *authctxt);
103: void do_authenticated2(Authctxt *authctxt);
104:
1.1 markus 105: /* import */
106: extern ServerOptions options;
107: extern char *__progname;
108: extern int log_stderr;
109: extern int debug_flag;
1.45 markus 110: extern u_int utmp_len;
1.21 markus 111: extern int startup_pipe;
1.74 markus 112: extern void destroy_sensitive_data(void);
1.21 markus 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:
1.87 markus 158: /* remove agent socket */
1.79 markus 159: if (auth_get_socket_name())
1.80 markus 160: auth_sock_cleanup_proc(authctxt->pw);
1.65 markus 161: }
162:
1.1 markus 163: /*
164: * Prepares for an interactive session. This is called after the user has
165: * been successfully authenticated. During this message exchange, pseudo
166: * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
167: * are requested, etc.
168: */
1.4 markus 169: void
1.65 markus 170: do_authenticated1(Authctxt *authctxt)
1.1 markus 171: {
172: Session *s;
1.65 markus 173: char *command;
1.86 markus 174: int success, type, plen, screen_flag;
1.1 markus 175: int compression_level = 0, enable_compression_after_reply = 0;
1.45 markus 176: u_int proto_len, data_len, dlen;
1.1 markus 177:
1.61 markus 178: s = session_new();
1.65 markus 179: s->pw = authctxt->pw;
1.28 millert 180:
1.1 markus 181: /*
182: * We stay in this loop until the client requests to execute a shell
183: * or a command.
184: */
185: for (;;) {
1.65 markus 186: success = 0;
1.1 markus 187:
188: /* Get a packet from the client. */
189: type = packet_read(&plen);
190:
191: /* Process the packet. */
192: switch (type) {
193: case SSH_CMSG_REQUEST_COMPRESSION:
194: packet_integrity_check(plen, 4, type);
195: compression_level = packet_get_int();
196: if (compression_level < 1 || compression_level > 9) {
197: packet_send_debug("Received illegal compression level %d.",
198: compression_level);
199: break;
200: }
201: /* Enable compression after we have responded with SUCCESS. */
202: enable_compression_after_reply = 1;
203: success = 1;
204: break;
205:
206: case SSH_CMSG_REQUEST_PTY:
1.86 markus 207: success = session_pty_req(s);
1.1 markus 208: break;
209:
210: case SSH_CMSG_X11_REQUEST_FORWARDING:
211: s->auth_proto = packet_get_string(&proto_len);
212: s->auth_data = packet_get_string(&data_len);
213:
1.57 markus 214: screen_flag = packet_get_protocol_flags() &
215: SSH_PROTOFLAG_SCREEN_NUMBER;
216: debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
217:
218: if (packet_remaining() == 4) {
219: if (!screen_flag)
220: debug2("Buggy client: "
221: "X11 screen flag missing");
1.1 markus 222: s->screen = packet_get_int();
1.56 markus 223: } else {
1.1 markus 224: s->screen = 0;
1.56 markus 225: }
1.81 markus 226: packet_done();
227: success = session_setup_x11fwd(s);
228: if (!success) {
229: xfree(s->auth_proto);
230: xfree(s->auth_data);
1.84 markus 231: s->auth_proto = NULL;
232: s->auth_data = NULL;
1.1 markus 233: }
234: break;
235:
236: case SSH_CMSG_AGENT_REQUEST_FORWARDING:
237: if (no_agent_forwarding_flag || compat13) {
238: debug("Authentication agent forwarding not permitted for this authentication.");
239: break;
240: }
241: debug("Received authentication agent forwarding request.");
1.65 markus 242: success = auth_input_request_forwarding(s->pw);
1.1 markus 243: break;
244:
245: case SSH_CMSG_PORT_FORWARD_REQUEST:
246: if (no_port_forwarding_flag) {
247: debug("Port forwarding not permitted for this authentication.");
1.39 markus 248: break;
249: }
250: if (!options.allow_tcp_forwarding) {
251: debug("Port forwarding not permitted.");
1.1 markus 252: break;
253: }
254: debug("Received TCP/IP port forwarding request.");
1.65 markus 255: channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
1.1 markus 256: success = 1;
257: break;
258:
259: case SSH_CMSG_MAX_PACKET_SIZE:
260: if (packet_set_maxsize(packet_get_int()) > 0)
261: success = 1;
262: break;
263:
264: case SSH_CMSG_EXEC_SHELL:
265: case SSH_CMSG_EXEC_CMD:
266: if (type == SSH_CMSG_EXEC_CMD) {
267: command = packet_get_string(&dlen);
268: debug("Exec command '%.500s'", command);
269: packet_integrity_check(plen, 4 + dlen, type);
270: } else {
271: command = NULL;
272: packet_integrity_check(plen, 0, type);
273: }
1.90 ! markus 274: do_exec(s, command);
1.82 markus 275: session_close(s);
1.1 markus 276: return;
277:
278: default:
279: /*
280: * Any unknown messages in this phase are ignored,
281: * and a failure message is returned.
282: */
283: log("Unknown packet type received after authentication: %d", type);
284: }
285: packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
286: packet_send();
287: packet_write_wait();
288:
289: /* Enable compression now that we have replied if appropriate. */
290: if (enable_compression_after_reply) {
291: enable_compression_after_reply = 0;
292: packet_start_compression(compression_level);
293: }
294: }
295: }
296:
297: /*
298: * This is called to fork and execute a command when we have no tty. This
299: * will call do_child from the child, and server_loop from the parent after
300: * setting up file descriptors and such.
301: */
1.4 markus 302: void
1.63 markus 303: do_exec_no_pty(Session *s, const char *command)
1.1 markus 304: {
305: int pid;
306:
307: #ifdef USE_PIPES
308: int pin[2], pout[2], perr[2];
309: /* Allocate pipes for communicating with the program. */
310: if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
311: packet_disconnect("Could not create pipes: %.100s",
312: strerror(errno));
313: #else /* USE_PIPES */
314: int inout[2], err[2];
315: /* Uses socket pairs to communicate with the program. */
316: if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
317: socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
318: packet_disconnect("Could not create socket pairs: %.100s",
319: strerror(errno));
320: #endif /* USE_PIPES */
321: if (s == NULL)
322: fatal("do_exec_no_pty: no session");
323:
1.9 markus 324: session_proctitle(s);
1.1 markus 325:
326: /* Fork the child. */
327: if ((pid = fork()) == 0) {
328: /* Child. Reinitialize the log since the pid has changed. */
329: log_init(__progname, options.log_level, options.log_facility, log_stderr);
330:
331: /*
332: * Create a new session and process group since the 4.4BSD
333: * setlogin() affects the entire process group.
334: */
335: if (setsid() < 0)
336: error("setsid failed: %.100s", strerror(errno));
337:
338: #ifdef USE_PIPES
339: /*
340: * Redirect stdin. We close the parent side of the socket
341: * pair, and make the child side the standard input.
342: */
343: close(pin[1]);
344: if (dup2(pin[0], 0) < 0)
345: perror("dup2 stdin");
346: close(pin[0]);
347:
348: /* Redirect stdout. */
349: close(pout[0]);
350: if (dup2(pout[1], 1) < 0)
351: perror("dup2 stdout");
352: close(pout[1]);
353:
354: /* Redirect stderr. */
355: close(perr[0]);
356: if (dup2(perr[1], 2) < 0)
357: perror("dup2 stderr");
358: close(perr[1]);
359: #else /* USE_PIPES */
360: /*
361: * Redirect stdin, stdout, and stderr. Stdin and stdout will
362: * use the same socket, as some programs (particularly rdist)
363: * seem to depend on it.
364: */
365: close(inout[1]);
366: close(err[1]);
367: if (dup2(inout[0], 0) < 0) /* stdin */
368: perror("dup2 stdin");
369: if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
370: perror("dup2 stdout");
371: if (dup2(err[0], 2) < 0) /* stderr */
372: perror("dup2 stderr");
373: #endif /* USE_PIPES */
374:
375: /* Do processing for the child (exec command etc). */
1.60 markus 376: do_child(s, command);
1.1 markus 377: /* NOTREACHED */
378: }
379: if (pid < 0)
380: packet_disconnect("fork failed: %.100s", strerror(errno));
381: s->pid = pid;
1.47 markus 382: /* Set interactive/non-interactive mode. */
1.48 markus 383: packet_set_interactive(s->display != NULL);
1.1 markus 384: #ifdef USE_PIPES
385: /* We are the parent. Close the child sides of the pipes. */
386: close(pin[0]);
387: close(pout[1]);
388: close(perr[1]);
389:
1.2 markus 390: if (compat20) {
1.64 markus 391: session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]);
1.2 markus 392: } else {
393: /* Enter the interactive session. */
394: server_loop(pid, pin[1], pout[0], perr[0]);
1.64 markus 395: /* server_loop has closed pin[1], pout[0], and perr[0]. */
1.2 markus 396: }
1.1 markus 397: #else /* USE_PIPES */
398: /* We are the parent. Close the child sides of the socket pairs. */
399: close(inout[0]);
400: close(err[0]);
401:
402: /*
403: * Enter the interactive session. Note: server_loop must be able to
404: * handle the case that fdin and fdout are the same.
405: */
1.2 markus 406: if (compat20) {
1.64 markus 407: session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]);
1.2 markus 408: } else {
409: server_loop(pid, inout[1], inout[1], err[1]);
410: /* server_loop has closed inout[1] and err[1]. */
411: }
1.1 markus 412: #endif /* USE_PIPES */
413: }
414:
415: /*
416: * This is called to fork and execute a command when we have a tty. This
417: * will call do_child from the child, and server_loop from the parent after
418: * setting up file descriptors, controlling tty, updating wtmp, utmp,
419: * lastlog, and other such operations.
420: */
1.4 markus 421: void
1.63 markus 422: do_exec_pty(Session *s, const char *command)
1.1 markus 423: {
424: int fdout, ptyfd, ttyfd, ptymaster;
425: pid_t pid;
426:
427: if (s == NULL)
428: fatal("do_exec_pty: no session");
429: ptyfd = s->ptyfd;
430: ttyfd = s->ttyfd;
431:
432: /* Fork the child. */
433: if ((pid = fork()) == 0) {
1.24 markus 434: /* Child. Reinitialize the log because the pid has changed. */
1.1 markus 435: log_init(__progname, options.log_level, options.log_facility, log_stderr);
436:
437: /* Close the master side of the pseudo tty. */
438: close(ptyfd);
439:
440: /* Make the pseudo tty our controlling tty. */
441: pty_make_controlling_tty(&ttyfd, s->tty);
442:
443: /* Redirect stdin from the pseudo tty. */
444: if (dup2(ttyfd, fileno(stdin)) < 0)
445: error("dup2 stdin failed: %.100s", strerror(errno));
446:
447: /* Redirect stdout to the pseudo tty. */
448: if (dup2(ttyfd, fileno(stdout)) < 0)
449: error("dup2 stdin failed: %.100s", strerror(errno));
450:
451: /* Redirect stderr to the pseudo tty. */
452: if (dup2(ttyfd, fileno(stderr)) < 0)
453: error("dup2 stdin failed: %.100s", strerror(errno));
454:
455: /* Close the extra descriptor for the pseudo tty. */
456: close(ttyfd);
457:
1.24 markus 458: /* record login, etc. similar to login(1) */
1.41 markus 459: if (!(options.use_login && command == NULL))
460: do_login(s, command);
1.1 markus 461:
462: /* Do common processing for the child, such as execing the command. */
1.60 markus 463: do_child(s, command);
1.1 markus 464: /* NOTREACHED */
465: }
466: if (pid < 0)
467: packet_disconnect("fork failed: %.100s", strerror(errno));
468: s->pid = pid;
469:
470: /* Parent. Close the slave side of the pseudo tty. */
471: close(ttyfd);
472:
473: /*
474: * Create another descriptor of the pty master side for use as the
475: * standard input. We could use the original descriptor, but this
476: * simplifies code in server_loop. The descriptor is bidirectional.
477: */
478: fdout = dup(ptyfd);
479: if (fdout < 0)
480: packet_disconnect("dup #1 failed: %.100s", strerror(errno));
481:
482: /* we keep a reference to the pty master */
483: ptymaster = dup(ptyfd);
484: if (ptymaster < 0)
485: packet_disconnect("dup #2 failed: %.100s", strerror(errno));
486: s->ptymaster = ptymaster;
487:
488: /* Enter interactive session. */
1.47 markus 489: packet_set_interactive(1);
1.2 markus 490: if (compat20) {
491: session_set_fds(s, ptyfd, fdout, -1);
492: } else {
493: server_loop(pid, ptyfd, fdout, -1);
494: /* server_loop _has_ closed ptyfd and fdout. */
1.24 markus 495: }
496: }
497:
1.90 ! markus 498: /*
! 499: * This is called to fork and execute a command. If another command is
! 500: * to be forced, execute that instead.
! 501: */
! 502: void
! 503: do_exec(Session *s, const char *command)
! 504: {
! 505: if (forced_command) {
! 506: original_command = command;
! 507: command = forced_command;
! 508: forced_command = NULL;
! 509: debug("Forced command '%.900s'", command);
! 510: }
! 511:
! 512: if (s->ttyfd != -1)
! 513: do_exec_pty(s, command);
! 514: else
! 515: do_exec_no_pty(s, command);
! 516:
! 517: if (command != NULL)
! 518: xfree(command);
! 519:
! 520: if (original_command != NULL) {
! 521: xfree(original_command);
! 522: original_command = NULL;
! 523: }
! 524: }
! 525:
! 526:
1.24 markus 527: /* administrative, login(1)-like work */
528: void
1.41 markus 529: do_login(Session *s, const char *command)
1.24 markus 530: {
531: char *time_string;
1.35 markus 532: char hostname[MAXHOSTNAMELEN];
1.24 markus 533: socklen_t fromlen;
534: struct sockaddr_storage from;
535: time_t last_login_time;
536: struct passwd * pw = s->pw;
537: pid_t pid = getpid();
538:
539: /*
540: * Get IP address of client. If the connection is not a socket, let
541: * the address be 0.0.0.0.
542: */
543: memset(&from, 0, sizeof(from));
544: if (packet_connection_is_on_socket()) {
545: fromlen = sizeof(from);
546: if (getpeername(packet_get_connection_in(),
547: (struct sockaddr *) & from, &fromlen) < 0) {
548: debug("getpeername: %.100s", strerror(errno));
549: fatal_cleanup();
550: }
551: }
1.25 markus 552:
1.35 markus 553: /* Get the time and hostname when the user last logged in. */
1.69 stevesk 554: if (options.print_lastlog) {
555: hostname[0] = '\0';
556: last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
557: hostname, sizeof(hostname));
558: }
1.35 markus 559:
1.24 markus 560: /* Record that there was a login on that tty from the remote host. */
561: record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
1.70 stevesk 562: get_remote_name_or_ip(utmp_len, options.reverse_mapping_check),
563: (struct sockaddr *)&from);
1.24 markus 564:
1.73 djm 565: if (check_quietlogin(s, command))
1.24 markus 566: return;
1.73 djm 567:
1.69 stevesk 568: if (options.print_lastlog && last_login_time != 0) {
1.24 markus 569: time_string = ctime(&last_login_time);
570: if (strchr(time_string, '\n'))
571: *strchr(time_string, '\n') = 0;
1.40 markus 572: if (strcmp(hostname, "") == 0)
1.24 markus 573: printf("Last login: %s\r\n", time_string);
574: else
1.36 markus 575: printf("Last login: %s from %s\r\n", time_string, hostname);
1.24 markus 576: }
1.73 djm 577:
578: do_motd();
579: }
580:
581: /*
582: * Display the message of the day.
583: */
584: void
585: do_motd(void)
586: {
587: FILE *f;
588: char buf[256];
589:
1.24 markus 590: if (options.print_motd) {
1.28 millert 591: #ifdef HAVE_LOGIN_CAP
592: f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
593: "/etc/motd"), "r");
594: #else
1.24 markus 595: f = fopen("/etc/motd", "r");
1.28 millert 596: #endif
1.24 markus 597: if (f) {
598: while (fgets(buf, sizeof(buf), f))
599: fputs(buf, stdout);
600: fclose(f);
601: }
1.2 markus 602: }
1.73 djm 603: }
604:
605:
606: /*
607: * Check for quiet login, either .hushlogin or command given.
608: */
609: int
610: check_quietlogin(Session *s, const char *command)
611: {
612: char buf[256];
613: struct passwd * pw = s->pw;
614: struct stat st;
615:
616: /* Return 1 if .hushlogin exists or a command given. */
617: if (command != NULL)
618: return 1;
619: snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
620: #ifdef HAVE_LOGIN_CAP
621: if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
622: return 1;
623: #else
624: if (stat(buf, &st) >= 0)
625: return 1;
626: #endif
627: return 0;
1.1 markus 628: }
629:
630: /*
631: * Sets the value of the given variable in the environment. If the variable
632: * already exists, its value is overriden.
633: */
1.4 markus 634: void
1.45 markus 635: child_set_env(char ***envp, u_int *envsizep, const char *name,
1.1 markus 636: const char *value)
637: {
1.45 markus 638: u_int i, namelen;
1.1 markus 639: char **env;
640:
641: /*
642: * Find the slot where the value should be stored. If the variable
643: * already exists, we reuse the slot; otherwise we append a new slot
644: * at the end of the array, expanding if necessary.
645: */
646: env = *envp;
647: namelen = strlen(name);
648: for (i = 0; env[i]; i++)
649: if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
650: break;
651: if (env[i]) {
652: /* Reuse the slot. */
653: xfree(env[i]);
654: } else {
655: /* New variable. Expand if necessary. */
656: if (i >= (*envsizep) - 1) {
657: (*envsizep) += 50;
658: env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
659: }
660: /* Need to set the NULL pointer at end of array beyond the new slot. */
661: env[i + 1] = NULL;
662: }
663:
664: /* Allocate space and format the variable in the appropriate slot. */
665: env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
666: snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
667: }
668:
669: /*
670: * Reads environment variables from the given file and adds/overrides them
671: * into the environment. If the file does not exist, this does nothing.
672: * Otherwise, it must consist of empty lines, comments (line starts with '#')
673: * and assignments of the form name=value. No other forms are allowed.
674: */
1.4 markus 675: void
1.45 markus 676: read_environment_file(char ***env, u_int *envsize,
1.1 markus 677: const char *filename)
678: {
679: FILE *f;
680: char buf[4096];
681: char *cp, *value;
682:
683: f = fopen(filename, "r");
684: if (!f)
685: return;
686:
687: while (fgets(buf, sizeof(buf), f)) {
688: for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
689: ;
690: if (!*cp || *cp == '#' || *cp == '\n')
691: continue;
692: if (strchr(cp, '\n'))
693: *strchr(cp, '\n') = '\0';
694: value = strchr(cp, '=');
695: if (value == NULL) {
696: fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
697: continue;
698: }
1.14 deraadt 699: /*
700: * Replace the equals sign by nul, and advance value to
701: * the value string.
702: */
1.1 markus 703: *value = '\0';
704: value++;
705: child_set_env(env, envsize, cp, value);
706: }
707: fclose(f);
708: }
709:
710: /*
711: * Performs common processing for the child, such as setting up the
712: * environment, closing extra file descriptors, setting the user and group
713: * ids, and executing the command or shell.
714: */
1.4 markus 715: void
1.60 markus 716: do_child(Session *s, const char *command)
1.1 markus 717: {
1.32 markus 718: const char *shell, *hostname = NULL, *cp = NULL;
1.60 markus 719: struct passwd * pw = s->pw;
1.1 markus 720: char buf[256];
1.16 markus 721: char cmd[1024];
1.27 millert 722: FILE *f = NULL;
1.45 markus 723: u_int envsize, i;
1.1 markus 724: char **env;
725: extern char **environ;
726: struct stat st;
727: char *argv[10];
1.84 markus 728: int do_xauth;
729:
730: do_xauth =
731: s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
1.17 markus 732:
1.74 markus 733: /* remove hostkey from the child's memory */
734: destroy_sensitive_data();
735:
1.17 markus 736: /* login(1) is only called if we execute the login shell */
737: if (options.use_login && command != NULL)
738: options.use_login = 0;
1.1 markus 739:
1.27 millert 740: if (!options.use_login) {
1.28 millert 741: #ifdef HAVE_LOGIN_CAP
742: if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
743: f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
744: _PATH_NOLOGIN), "r");
745: #else
1.27 millert 746: if (pw->pw_uid)
747: f = fopen(_PATH_NOLOGIN, "r");
1.28 millert 748: #endif
1.27 millert 749: if (f) {
750: /* /etc/nologin exists. Print its contents and exit. */
751: while (fgets(buf, sizeof(buf), f))
752: fputs(buf, stderr);
753: fclose(f);
1.1 markus 754: exit(254);
1.27 millert 755: }
1.1 markus 756: }
1.28 millert 757: /* Set login name, uid, gid, and groups. */
1.1 markus 758: /* Login(1) does this as well, and it needs uid 0 for the "-h"
759: switch, so we let login(1) to this for us. */
760: if (!options.use_login) {
761: if (getuid() == 0 || geteuid() == 0) {
1.28 millert 762: #ifdef HAVE_LOGIN_CAP
763: if (setusercontext(lc, pw, pw->pw_uid,
764: (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
765: perror("unable to set user context");
766: exit(1);
767: }
768: #else
769: if (setlogin(pw->pw_name) < 0)
770: error("setlogin failed: %s", strerror(errno));
1.1 markus 771: if (setgid(pw->pw_gid) < 0) {
772: perror("setgid");
773: exit(1);
774: }
775: /* Initialize the group list. */
776: if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
777: perror("initgroups");
778: exit(1);
779: }
780: endgrent();
781:
782: /* Permanently switch to the desired uid. */
1.71 markus 783: permanently_set_uid(pw);
1.28 millert 784: #endif
1.1 markus 785: }
786: if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1.31 deraadt 787: fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1.1 markus 788: }
789: /*
790: * Get the shell from the password data. An empty shell field is
791: * legal, and means /bin/sh.
792: */
793: shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1.28 millert 794: #ifdef HAVE_LOGIN_CAP
795: shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
796: #endif
1.1 markus 797:
798: #ifdef AFS
799: /* Try to get AFS tokens for the local cell. */
800: if (k_hasafs()) {
801: char cell[64];
802:
803: if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
804: krb_afslog(cell, 0);
805:
806: krb_afslog(0, 0);
807: }
808: #endif /* AFS */
809:
810: /* Initialize the environment. */
811: envsize = 100;
812: env = xmalloc(envsize * sizeof(char *));
813: env[0] = NULL;
814:
815: if (!options.use_login) {
816: /* Set basic environment. */
817: child_set_env(&env, &envsize, "USER", pw->pw_name);
818: child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
819: child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1.28 millert 820: #ifdef HAVE_LOGIN_CAP
1.29 millert 821: (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
822: child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1.28 millert 823: #else
1.29 millert 824: child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1.28 millert 825: #endif
1.1 markus 826:
827: snprintf(buf, sizeof buf, "%.200s/%.50s",
828: _PATH_MAILDIR, pw->pw_name);
829: child_set_env(&env, &envsize, "MAIL", buf);
830:
831: /* Normal systems set SHELL by default. */
832: child_set_env(&env, &envsize, "SHELL", shell);
833: }
834: if (getenv("TZ"))
835: child_set_env(&env, &envsize, "TZ", getenv("TZ"));
836:
837: /* Set custom environment options from RSA authentication. */
838: while (custom_environment) {
839: struct envstring *ce = custom_environment;
840: char *s = ce->s;
841: int i;
842: for (i = 0; s[i] != '=' && s[i]; i++);
843: if (s[i] == '=') {
844: s[i] = 0;
845: child_set_env(&env, &envsize, s, s + i + 1);
846: }
847: custom_environment = ce->next;
848: xfree(ce->s);
849: xfree(ce);
850: }
851:
852: snprintf(buf, sizeof buf, "%.50s %d %d",
853: get_remote_ipaddr(), get_remote_port(), get_local_port());
854: child_set_env(&env, &envsize, "SSH_CLIENT", buf);
855:
1.60 markus 856: if (s->ttyfd != -1)
857: child_set_env(&env, &envsize, "SSH_TTY", s->tty);
858: if (s->term)
859: child_set_env(&env, &envsize, "TERM", s->term);
860: if (s->display)
861: child_set_env(&env, &envsize, "DISPLAY", s->display);
1.34 markus 862: if (original_command)
863: child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
864: original_command);
1.1 markus 865:
866: #ifdef KRB4
867: {
868: extern char *ticket;
869:
870: if (ticket)
871: child_set_env(&env, &envsize, "KRBTKFILE", ticket);
872: }
873: #endif /* KRB4 */
874:
875: if (auth_get_socket_name() != NULL)
876: child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
877: auth_get_socket_name());
878:
879: /* read $HOME/.ssh/environment. */
880: if (!options.use_login) {
1.14 deraadt 881: snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
882: pw->pw_dir);
1.1 markus 883: read_environment_file(&env, &envsize, buf);
884: }
885: if (debug_flag) {
886: /* dump the environment */
887: fprintf(stderr, "Environment:\n");
888: for (i = 0; env[i]; i++)
889: fprintf(stderr, " %.200s\n", env[i]);
890: }
1.26 millert 891: /* we have to stash the hostname before we close our socket. */
892: if (options.use_login)
1.70 stevesk 893: hostname = get_remote_name_or_ip(utmp_len,
894: options.reverse_mapping_check);
1.1 markus 895: /*
896: * Close the connection descriptors; note that this is the child, and
897: * the server will still have the socket open, and it is important
898: * that we do not shutdown it. Note that the descriptors cannot be
899: * closed before building the environment, as we call
900: * get_remote_ipaddr there.
901: */
902: if (packet_get_connection_in() == packet_get_connection_out())
903: close(packet_get_connection_in());
904: else {
905: close(packet_get_connection_in());
906: close(packet_get_connection_out());
907: }
908: /*
909: * Close all descriptors related to channels. They will still remain
910: * open in the parent.
911: */
912: /* XXX better use close-on-exec? -markus */
913: channel_close_all();
914:
915: /*
916: * Close any extra file descriptors. Note that there may still be
917: * descriptors left by system functions. They will be closed later.
918: */
919: endpwent();
920:
921: /*
922: * Close any extra open file descriptors so that we don\'t have them
923: * hanging around in clients. Note that we want to do this after
924: * initgroups, because at least on Solaris 2.3 it leaves file
925: * descriptors open.
926: */
927: for (i = 3; i < 64; i++)
928: close(i);
929:
930: /* Change current directory to the user\'s home directory. */
1.28 millert 931: if (chdir(pw->pw_dir) < 0) {
1.1 markus 932: fprintf(stderr, "Could not chdir to home directory %s: %s\n",
933: pw->pw_dir, strerror(errno));
1.28 millert 934: #ifdef HAVE_LOGIN_CAP
935: if (login_getcapbool(lc, "requirehome", 0))
936: exit(1);
937: #endif
938: }
1.1 markus 939:
940: /*
941: * Must take new environment into use so that .ssh/rc, /etc/sshrc and
942: * xauth are run in the proper environment.
943: */
944: environ = env;
945:
946: /*
947: * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
948: * in this order).
949: */
950: if (!options.use_login) {
1.74 markus 951: /* ignore _PATH_SSH_USER_RC for subsystems */
952: if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
1.75 markus 953: snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
954: shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
1.1 markus 955: if (debug_flag)
1.75 markus 956: fprintf(stderr, "Running %s\n", cmd);
957: f = popen(cmd, "w");
1.1 markus 958: if (f) {
1.60 markus 959: if (do_xauth)
960: fprintf(f, "%s %s\n", s->auth_proto,
961: s->auth_data);
1.1 markus 962: pclose(f);
963: } else
1.60 markus 964: fprintf(stderr, "Could not run %s\n",
965: _PATH_SSH_USER_RC);
1.50 markus 966: } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1.1 markus 967: if (debug_flag)
1.60 markus 968: fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
969: _PATH_SSH_SYSTEM_RC);
1.50 markus 970: f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1.1 markus 971: if (f) {
1.60 markus 972: if (do_xauth)
973: fprintf(f, "%s %s\n", s->auth_proto,
974: s->auth_data);
1.1 markus 975: pclose(f);
976: } else
1.60 markus 977: fprintf(stderr, "Could not run %s\n",
978: _PATH_SSH_SYSTEM_RC);
979: } else if (do_xauth && options.xauth_location != NULL) {
1.1 markus 980: /* Add authority data to .Xauthority if appropriate. */
1.60 markus 981: char *screen = strchr(s->display, ':');
982:
983: if (debug_flag) {
984: fprintf(stderr,
985: "Running %.100s add "
986: "%.100s %.100s %.100s\n",
987: options.xauth_location, s->display,
988: s->auth_proto, s->auth_data);
989: if (screen != NULL)
1.14 deraadt 990: fprintf(stderr,
1.60 markus 991: "Adding %.*s/unix%s %s %s\n",
992: (int)(screen - s->display),
993: s->display, screen,
994: s->auth_proto, s->auth_data);
995: }
996: snprintf(cmd, sizeof cmd, "%s -q -",
997: options.xauth_location);
998: f = popen(cmd, "w");
999: if (f) {
1000: fprintf(f, "add %s %s %s\n", s->display,
1001: s->auth_proto, s->auth_data);
1002: if (screen != NULL)
1003: fprintf(f, "add %.*s/unix%s %s %s\n",
1004: (int)(screen - s->display),
1005: s->display, screen,
1006: s->auth_proto,
1007: s->auth_data);
1008: pclose(f);
1009: } else {
1010: fprintf(stderr, "Could not run %s\n",
1011: cmd);
1.1 markus 1012: }
1013: }
1014: /* Get the last component of the shell name. */
1015: cp = strrchr(shell, '/');
1016: if (cp)
1017: cp++;
1018: else
1019: cp = shell;
1020: }
1.67 markus 1021:
1022: /* restore SIGPIPE for child */
1023: signal(SIGPIPE, SIG_DFL);
1024:
1.1 markus 1025: /*
1026: * If we have no command, execute the shell. In this case, the shell
1027: * name to be passed in argv[0] is preceded by '-' to indicate that
1028: * this is a login shell.
1029: */
1030: if (!command) {
1031: if (!options.use_login) {
1032: char buf[256];
1033:
1034: /*
1035: * Check for mail if we have a tty and it was enabled
1036: * in server options.
1037: */
1.60 markus 1038: if (s->ttyfd != -1 && options.check_mail) {
1.1 markus 1039: char *mailbox;
1040: struct stat mailstat;
1.60 markus 1041:
1.1 markus 1042: mailbox = getenv("MAIL");
1043: if (mailbox != NULL) {
1.14 deraadt 1044: if (stat(mailbox, &mailstat) != 0 ||
1045: mailstat.st_size == 0)
1.1 markus 1046: printf("No mail.\n");
1047: else if (mailstat.st_mtime < mailstat.st_atime)
1048: printf("You have mail.\n");
1049: else
1050: printf("You have new mail.\n");
1051: }
1052: }
1053: /* Start the shell. Set initial character to '-'. */
1054: buf[0] = '-';
1055: strncpy(buf + 1, cp, sizeof(buf) - 1);
1056: buf[sizeof(buf) - 1] = 0;
1057:
1058: /* Execute the shell. */
1059: argv[0] = buf;
1060: argv[1] = NULL;
1061: execve(shell, argv, env);
1062:
1063: /* Executing the shell failed. */
1064: perror(shell);
1065: exit(1);
1066:
1067: } else {
1068: /* Launch login(1). */
1069:
1.26 millert 1070: execl("/usr/bin/login", "login", "-h", hostname,
1.25 markus 1071: "-p", "-f", "--", pw->pw_name, NULL);
1.1 markus 1072:
1073: /* Login couldn't be executed, die. */
1074:
1075: perror("login");
1076: exit(1);
1077: }
1078: }
1079: /*
1080: * Execute the command using the user's shell. This uses the -c
1081: * option to execute the command.
1082: */
1083: argv[0] = (char *) cp;
1084: argv[1] = "-c";
1085: argv[2] = (char *) command;
1086: argv[3] = NULL;
1087: execve(shell, argv, env);
1088: perror(shell);
1089: exit(1);
1090: }
1091:
1092: Session *
1093: session_new(void)
1094: {
1095: int i;
1096: static int did_init = 0;
1097: if (!did_init) {
1098: debug("session_new: init");
1099: for(i = 0; i < MAX_SESSIONS; i++) {
1100: sessions[i].used = 0;
1101: }
1102: did_init = 1;
1103: }
1104: for(i = 0; i < MAX_SESSIONS; i++) {
1105: Session *s = &sessions[i];
1106: if (! s->used) {
1.68 djm 1107: memset(s, 0, sizeof(*s));
1.1 markus 1108: s->chanid = -1;
1109: s->ptyfd = -1;
1110: s->ttyfd = -1;
1111: s->used = 1;
1.85 markus 1112: s->self = i;
1.1 markus 1113: debug("session_new: session %d", i);
1114: return s;
1115: }
1116: }
1117: return NULL;
1118: }
1119:
1120: void
1121: session_dump(void)
1122: {
1123: int i;
1124: for(i = 0; i < MAX_SESSIONS; i++) {
1125: Session *s = &sessions[i];
1126: debug("dump: used %d session %d %p channel %d pid %d",
1127: s->used,
1128: s->self,
1129: s,
1130: s->chanid,
1131: s->pid);
1132: }
1133: }
1134:
1.2 markus 1135: int
1136: session_open(int chanid)
1137: {
1138: Session *s = session_new();
1139: debug("session_open: channel %d", chanid);
1140: if (s == NULL) {
1141: error("no more sessions");
1142: return 0;
1143: }
1.7 markus 1144: s->pw = auth_get_user();
1145: if (s->pw == NULL)
1.54 stevesk 1146: fatal("no user for session %d", s->self);
1.2 markus 1147: debug("session_open: session %d: link with channel %d", s->self, chanid);
1148: s->chanid = chanid;
1149: return 1;
1150: }
1151:
1152: Session *
1153: session_by_channel(int id)
1154: {
1155: int i;
1156: for(i = 0; i < MAX_SESSIONS; i++) {
1157: Session *s = &sessions[i];
1158: if (s->used && s->chanid == id) {
1159: debug("session_by_channel: session %d channel %d", i, id);
1160: return s;
1161: }
1162: }
1163: debug("session_by_channel: unknown channel %d", id);
1164: session_dump();
1165: return NULL;
1166: }
1167:
1168: Session *
1169: session_by_pid(pid_t pid)
1170: {
1171: int i;
1172: debug("session_by_pid: pid %d", pid);
1173: for(i = 0; i < MAX_SESSIONS; i++) {
1174: Session *s = &sessions[i];
1175: if (s->used && s->pid == pid)
1176: return s;
1177: }
1178: error("session_by_pid: unknown pid %d", pid);
1179: session_dump();
1180: return NULL;
1181: }
1182:
1183: int
1184: session_window_change_req(Session *s)
1185: {
1186: s->col = packet_get_int();
1187: s->row = packet_get_int();
1188: s->xpixel = packet_get_int();
1189: s->ypixel = packet_get_int();
1.3 markus 1190: packet_done();
1.2 markus 1191: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1192: return 1;
1193: }
1194:
1195: int
1196: session_pty_req(Session *s)
1197: {
1.45 markus 1198: u_int len;
1.72 stevesk 1199: int n_bytes;
1.2 markus 1200:
1.86 markus 1201: if (no_pty_flag) {
1202: debug("Allocating a pty not permitted for this authentication.");
1.19 markus 1203: return 0;
1.86 markus 1204: }
1205: if (s->ttyfd != -1) {
1206: packet_disconnect("Protocol error: you already have a pty.");
1.3 markus 1207: return 0;
1.86 markus 1208: }
1209:
1.2 markus 1210: s->term = packet_get_string(&len);
1.86 markus 1211:
1212: if (compat20) {
1213: s->col = packet_get_int();
1214: s->row = packet_get_int();
1215: } else {
1216: s->row = packet_get_int();
1217: s->col = packet_get_int();
1218: }
1.2 markus 1219: s->xpixel = packet_get_int();
1220: s->ypixel = packet_get_int();
1221:
1222: if (strcmp(s->term, "") == 0) {
1223: xfree(s->term);
1224: s->term = NULL;
1225: }
1.86 markus 1226:
1.2 markus 1227: /* Allocate a pty and open it. */
1.86 markus 1228: debug("Allocating pty.");
1.2 markus 1229: if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1.86 markus 1230: if (s->term)
1231: xfree(s->term);
1.2 markus 1232: s->term = NULL;
1233: s->ptyfd = -1;
1234: s->ttyfd = -1;
1235: error("session_pty_req: session %d alloc failed", s->self);
1.3 markus 1236: return 0;
1.2 markus 1237: }
1238: debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1.86 markus 1239:
1240: /* for SSH1 the tty modes length is not given */
1241: if (!compat20)
1242: n_bytes = packet_remaining();
1243: tty_parse_modes(s->ttyfd, &n_bytes);
1244:
1.2 markus 1245: /*
1246: * Add a cleanup function to clear the utmp entry and record logout
1247: * time in case we call fatal() (e.g., the connection gets closed).
1248: */
1.85 markus 1249: fatal_add_cleanup(session_pty_cleanup, (void *)s);
1.2 markus 1250: pty_setowner(s->pw, s->tty);
1.86 markus 1251:
1252: /* Set window size from the packet. */
1.2 markus 1253: pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1254:
1.72 stevesk 1255: packet_done();
1.9 markus 1256: session_proctitle(s);
1.2 markus 1257: return 1;
1258: }
1259:
1.7 markus 1260: int
1261: session_subsystem_req(Session *s)
1262: {
1.45 markus 1263: u_int len;
1.7 markus 1264: int success = 0;
1265: char *subsys = packet_get_string(&len);
1.18 jakob 1266: int i;
1.7 markus 1267:
1268: packet_done();
1269: log("subsystem request for %s", subsys);
1.18 jakob 1270:
1271: for (i = 0; i < options.num_subsystems; i++) {
1272: if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1273: debug("subsystem: exec() %s", options.subsystem_command[i]);
1.64 markus 1274: s->is_subsystem = 1;
1.63 markus 1275: do_exec_no_pty(s, options.subsystem_command[i]);
1.18 jakob 1276: success = 1;
1277: }
1278: }
1279:
1280: if (!success)
1281: log("subsystem request for %s failed, subsystem not found", subsys);
1.7 markus 1282:
1283: xfree(subsys);
1284: return success;
1285: }
1286:
1287: int
1288: session_x11_req(Session *s)
1289: {
1.81 markus 1290: int success;
1.7 markus 1291:
1292: s->single_connection = packet_get_char();
1293: s->auth_proto = packet_get_string(NULL);
1294: s->auth_data = packet_get_string(NULL);
1295: s->screen = packet_get_int();
1296: packet_done();
1297:
1.81 markus 1298: success = session_setup_x11fwd(s);
1299: if (!success) {
1.7 markus 1300: xfree(s->auth_proto);
1301: xfree(s->auth_data);
1.84 markus 1302: s->auth_proto = NULL;
1303: s->auth_data = NULL;
1.7 markus 1304: }
1.81 markus 1305: return success;
1.7 markus 1306: }
1307:
1.19 markus 1308: int
1309: session_shell_req(Session *s)
1310: {
1311: packet_done();
1.90 ! markus 1312: do_exec(s, NULL);
1.19 markus 1313: return 1;
1314: }
1315:
1316: int
1317: session_exec_req(Session *s)
1318: {
1.45 markus 1319: u_int len;
1.19 markus 1320: char *command = packet_get_string(&len);
1321: packet_done();
1.90 ! markus 1322: do_exec(s, command);
1.19 markus 1323: return 1;
1324: }
1325:
1.43 markus 1326: int
1327: session_auth_agent_req(Session *s)
1328: {
1329: static int called = 0;
1330: packet_done();
1.44 markus 1331: if (no_agent_forwarding_flag) {
1332: debug("session_auth_agent_req: no_agent_forwarding_flag");
1333: return 0;
1334: }
1.43 markus 1335: if (called) {
1336: return 0;
1337: } else {
1338: called = 1;
1339: return auth_input_request_forwarding(s->pw);
1340: }
1341: }
1342:
1.2 markus 1343: void
1344: session_input_channel_req(int id, void *arg)
1345: {
1.45 markus 1346: u_int len;
1.2 markus 1347: int reply;
1348: int success = 0;
1349: char *rtype;
1350: Session *s;
1351: Channel *c;
1352:
1353: rtype = packet_get_string(&len);
1354: reply = packet_get_char();
1355:
1356: s = session_by_channel(id);
1357: if (s == NULL)
1358: fatal("session_input_channel_req: channel %d: no session", id);
1359: c = channel_lookup(id);
1360: if (c == NULL)
1361: fatal("session_input_channel_req: channel %d: bad channel", id);
1362:
1363: debug("session_input_channel_req: session %d channel %d request %s reply %d",
1364: s->self, id, rtype, reply);
1365:
1366: /*
1.64 markus 1367: * a session is in LARVAL state until a shell, a command
1368: * or a subsystem is executed
1.2 markus 1369: */
1370: if (c->type == SSH_CHANNEL_LARVAL) {
1371: if (strcmp(rtype, "shell") == 0) {
1.19 markus 1372: success = session_shell_req(s);
1.2 markus 1373: } else if (strcmp(rtype, "exec") == 0) {
1.19 markus 1374: success = session_exec_req(s);
1.2 markus 1375: } else if (strcmp(rtype, "pty-req") == 0) {
1.3 markus 1376: success = session_pty_req(s);
1.7 markus 1377: } else if (strcmp(rtype, "x11-req") == 0) {
1378: success = session_x11_req(s);
1.43 markus 1379: } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1380: success = session_auth_agent_req(s);
1.7 markus 1381: } else if (strcmp(rtype, "subsystem") == 0) {
1382: success = session_subsystem_req(s);
1.2 markus 1383: }
1384: }
1385: if (strcmp(rtype, "window-change") == 0) {
1386: success = session_window_change_req(s);
1387: }
1388:
1389: if (reply) {
1390: packet_start(success ?
1391: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1392: packet_put_int(c->remote_id);
1393: packet_send();
1394: }
1395: xfree(rtype);
1396: }
1397:
1398: void
1399: session_set_fds(Session *s, int fdin, int fdout, int fderr)
1400: {
1401: if (!compat20)
1402: fatal("session_set_fds: called for proto != 2.0");
1403: /*
1404: * now that have a child and a pipe to the child,
1405: * we can activate our channel and register the fd's
1406: */
1407: if (s->chanid == -1)
1408: fatal("no channel for session %d", s->self);
1409: channel_set_fds(s->chanid,
1410: fdout, fdin, fderr,
1.42 markus 1411: fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1412: 1);
1.2 markus 1413: }
1414:
1.85 markus 1415: /*
1416: * Function to perform pty cleanup. Also called if we get aborted abnormally
1417: * (e.g., due to a dropped connection).
1418: */
1.1 markus 1419: void
1.85 markus 1420: session_pty_cleanup(void *session)
1.1 markus 1421: {
1.85 markus 1422: Session *s = session;
1423:
1424: if (s == NULL) {
1425: error("session_pty_cleanup: no session");
1426: return;
1427: }
1428: if (s->ttyfd == -1)
1.1 markus 1429: return;
1430:
1.54 stevesk 1431: debug("session_pty_cleanup: session %d release %s", s->self, s->tty);
1.1 markus 1432:
1433: /* Record that the user has logged out. */
1.85 markus 1434: if (s->pid != 0)
1435: record_logout(s->pid, s->tty);
1.1 markus 1436:
1437: /* Release the pseudo-tty. */
1438: pty_release(s->tty);
1439:
1440: /*
1441: * Close the server side of the socket pairs. We must do this after
1442: * the pty cleanup, so that another process doesn't get this pty
1443: * while we're still cleaning up.
1444: */
1445: if (close(s->ptymaster) < 0)
1446: error("close(s->ptymaster): %s", strerror(errno));
1.2 markus 1447: }
1448:
1449: void
1450: session_exit_message(Session *s, int status)
1451: {
1452: Channel *c;
1453: if (s == NULL)
1454: fatal("session_close: no session");
1455: c = channel_lookup(s->chanid);
1456: if (c == NULL)
1.85 markus 1457: fatal("session_exit_message: session %d: no channel %d",
1.2 markus 1458: s->self, s->chanid);
1459: debug("session_exit_message: session %d channel %d pid %d",
1460: s->self, s->chanid, s->pid);
1461:
1462: if (WIFEXITED(status)) {
1463: channel_request_start(s->chanid,
1464: "exit-status", 0);
1465: packet_put_int(WEXITSTATUS(status));
1466: packet_send();
1467: } else if (WIFSIGNALED(status)) {
1468: channel_request_start(s->chanid,
1469: "exit-signal", 0);
1470: packet_put_int(WTERMSIG(status));
1471: packet_put_char(WCOREDUMP(status));
1472: packet_put_cstring("");
1473: packet_put_cstring("");
1474: packet_send();
1475: } else {
1476: /* Some weird exit cause. Just exit. */
1477: packet_disconnect("wait returned status %04x.", status);
1478: }
1479:
1480: /* disconnect channel */
1481: debug("session_exit_message: release channel %d", s->chanid);
1482: channel_cancel_cleanup(s->chanid);
1.5 markus 1483: /*
1484: * emulate a write failure with 'chan_write_failed', nobody will be
1485: * interested in data we write.
1486: * Note that we must not call 'chan_read_failed', since there could
1487: * be some more data waiting in the pipe.
1488: */
1.8 markus 1489: if (c->ostate != CHAN_OUTPUT_CLOSED)
1490: chan_write_failed(c);
1.2 markus 1491: s->chanid = -1;
1492: }
1493:
1494: void
1.85 markus 1495: session_close(Session *s)
1.2 markus 1496: {
1.85 markus 1497: debug("session_close: session %d pid %d", s->self, s->pid);
1498: if (s->ttyfd != -1) {
1499: fatal_remove_cleanup(session_pty_cleanup, (void *)s);
1500: session_pty_cleanup(s);
1501: }
1.2 markus 1502: if (s->term)
1503: xfree(s->term);
1504: if (s->display)
1505: xfree(s->display);
1506: if (s->auth_data)
1507: xfree(s->auth_data);
1508: if (s->auth_proto)
1509: xfree(s->auth_proto);
1510: s->used = 0;
1.9 markus 1511: session_proctitle(s);
1.2 markus 1512: }
1513:
1514: void
1515: session_close_by_pid(pid_t pid, int status)
1516: {
1517: Session *s = session_by_pid(pid);
1518: if (s == NULL) {
1.89 markus 1519: debug("session_close_by_pid: no session for pid %d", pid);
1.2 markus 1520: return;
1521: }
1522: if (s->chanid != -1)
1523: session_exit_message(s, status);
1524: session_close(s);
1525: }
1526:
1527: /*
1528: * this is called when a channel dies before
1529: * the session 'child' itself dies
1530: */
1531: void
1532: session_close_by_channel(int id, void *arg)
1533: {
1534: Session *s = session_by_channel(id);
1535: if (s == NULL) {
1536: debug("session_close_by_channel: no session for channel %d", id);
1537: return;
1538: }
1539: /* disconnect channel */
1540: channel_cancel_cleanup(s->chanid);
1541: s->chanid = -1;
1542:
1543: debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1544: if (s->pid == 0) {
1545: /* close session immediately */
1546: session_close(s);
1547: } else {
1548: /* notify child, delay session cleanup */
1549: if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1550: error("session_close_by_channel: kill %d: %s",
1551: s->pid, strerror(errno));
1552: }
1.9 markus 1553: }
1554:
1555: char *
1556: session_tty_list(void)
1557: {
1558: static char buf[1024];
1559: int i;
1560: buf[0] = '\0';
1561: for(i = 0; i < MAX_SESSIONS; i++) {
1562: Session *s = &sessions[i];
1563: if (s->used && s->ttyfd != -1) {
1564: if (buf[0] != '\0')
1565: strlcat(buf, ",", sizeof buf);
1566: strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1567: }
1568: }
1569: if (buf[0] == '\0')
1570: strlcpy(buf, "notty", sizeof buf);
1571: return buf;
1572: }
1573:
1574: void
1575: session_proctitle(Session *s)
1576: {
1577: if (s->pw == NULL)
1578: error("no user for session %d", s->self);
1579: else
1580: setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
1.81 markus 1581: }
1582:
1583: int
1584: session_setup_x11fwd(Session *s)
1585: {
1586: struct stat st;
1587:
1588: if (no_x11_forwarding_flag) {
1589: packet_send_debug("X11 forwarding disabled in user configuration file.");
1590: return 0;
1591: }
1592: if (!options.x11_forwarding) {
1593: debug("X11 forwarding disabled in server configuration file.");
1594: return 0;
1595: }
1596: if (!options.xauth_location ||
1597: (stat(options.xauth_location, &st) == -1)) {
1598: packet_send_debug("No xauth program; cannot forward with spoofing.");
1599: return 0;
1600: }
1.87 markus 1601: if (s->display != NULL) {
1.81 markus 1602: debug("X11 display already set.");
1603: return 0;
1604: }
1605: s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1606: if (s->display == NULL) {
1.87 markus 1607: debug("x11_create_display_inet failed.");
1.81 markus 1608: return 0;
1609: }
1610: return 1;
1.2 markus 1611: }
1612:
1613: void
1.49 markus 1614: do_authenticated2(Authctxt *authctxt)
1.2 markus 1615: {
1616: server_loop2();
1.1 markus 1617: }
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