1 /* $OpenBSD: session.c,v 1.300 2018/06/09 03:03:10 djm Exp $ */ 2 /* 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * 6 * As far as I am concerned, the code I have written for this software 7 * can be used freely for any purpose. Any derived versions of this 8 * software must be clearly marked as such, and if the derived work is 9 * incompatible with the protocol description in the RFC file, it must be 10 * called by a name other than "ssh" or "Secure Shell". 11 * 12 * SSH2 support by Markus Friedl. 13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #include <sys/types.h> 37 #include <sys/wait.h> 38 #include <sys/un.h> 39 #include <sys/stat.h> 40 #include <sys/socket.h> 41 #include <sys/queue.h> 42 43 #include <ctype.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <grp.h> 47 #include <login_cap.h> 48 #include <netdb.h> 49 #include <paths.h> 50 #include <pwd.h> 51 #include <signal.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 #include <limits.h> 57 58 #include "xmalloc.h" 59 #include "ssh.h" 60 #include "ssh2.h" 61 #include "sshpty.h" 62 #include "packet.h" 63 #include "buffer.h" 64 #include "match.h" 65 #include "uidswap.h" 66 #include "compat.h" 67 #include "channels.h" 68 #include "key.h" 69 #include "cipher.h" 70 #include "kex.h" 71 #include "hostfile.h" 72 #include "auth.h" 73 #include "auth-options.h" 74 #include "authfd.h" 75 #include "pathnames.h" 76 #include "log.h" 77 #include "misc.h" 78 #include "servconf.h" 79 #include "sshlogin.h" 80 #include "serverloop.h" 81 #include "canohost.h" 82 #include "session.h" 83 #ifdef GSSAPI 84 #include "ssh-gss.h" 85 #endif 86 #include "monitor_wrap.h" 87 #include "sftp.h" 88 #include "atomicio.h" 89 90 #ifdef KRB5 91 #include <kafs.h> 92 #endif 93 94 #define IS_INTERNAL_SFTP(c) \ 95 (!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \ 96 (c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \ 97 c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \ 98 c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t')) 99 100 /* func */ 101 102 Session *session_new(void); 103 void session_set_fds(struct ssh *, Session *, int, int, int, int, int); 104 void session_pty_cleanup(Session *); 105 void session_proctitle(Session *); 106 int session_setup_x11fwd(struct ssh *, Session *); 107 int do_exec_pty(struct ssh *, Session *, const char *); 108 int do_exec_no_pty(struct ssh *, Session *, const char *); 109 int do_exec(struct ssh *, Session *, const char *); 110 void do_login(struct ssh *, Session *, const char *); 111 void do_child(struct ssh *, Session *, const char *); 112 void do_motd(void); 113 int check_quietlogin(Session *, const char *); 114 115 static void do_authenticated2(struct ssh *, Authctxt *); 116 117 static int session_pty_req(struct ssh *, Session *); 118 119 /* import */ 120 extern ServerOptions options; 121 extern char *__progname; 122 extern int debug_flag; 123 extern u_int utmp_len; 124 extern int startup_pipe; 125 extern void destroy_sensitive_data(void); 126 extern Buffer loginmsg; 127 extern struct sshauthopt *auth_opts; 128 char *tun_fwd_ifnames; /* serverloop.c */ 129 130 /* original command from peer. */ 131 const char *original_command = NULL; 132 133 /* data */ 134 static int sessions_first_unused = -1; 135 static int sessions_nalloc = 0; 136 static Session *sessions = NULL; 137 138 #define SUBSYSTEM_NONE 0 139 #define SUBSYSTEM_EXT 1 140 #define SUBSYSTEM_INT_SFTP 2 141 #define SUBSYSTEM_INT_SFTP_ERROR 3 142 143 login_cap_t *lc; 144 145 static int is_child = 0; 146 static int in_chroot = 0; 147 148 /* File containing userauth info, if ExposeAuthInfo set */ 149 static char *auth_info_file = NULL; 150 151 /* Name and directory of socket for authentication agent forwarding. */ 152 static char *auth_sock_name = NULL; 153 static char *auth_sock_dir = NULL; 154 155 /* removes the agent forwarding socket */ 156 157 static void 158 auth_sock_cleanup_proc(struct passwd *pw) 159 { 160 if (auth_sock_name != NULL) { 161 temporarily_use_uid(pw); 162 unlink(auth_sock_name); 163 rmdir(auth_sock_dir); 164 auth_sock_name = NULL; 165 restore_uid(); 166 } 167 } 168 169 static int 170 auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw) 171 { 172 Channel *nc; 173 int sock = -1; 174 175 if (auth_sock_name != NULL) { 176 error("authentication forwarding requested twice."); 177 return 0; 178 } 179 180 /* Temporarily drop privileged uid for mkdir/bind. */ 181 temporarily_use_uid(pw); 182 183 /* Allocate a buffer for the socket name, and format the name. */ 184 auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX"); 185 186 /* Create private directory for socket */ 187 if (mkdtemp(auth_sock_dir) == NULL) { 188 packet_send_debug("Agent forwarding disabled: " 189 "mkdtemp() failed: %.100s", strerror(errno)); 190 restore_uid(); 191 free(auth_sock_dir); 192 auth_sock_dir = NULL; 193 goto authsock_err; 194 } 195 196 xasprintf(&auth_sock_name, "%s/agent.%ld", 197 auth_sock_dir, (long) getpid()); 198 199 /* Start a Unix listener on auth_sock_name. */ 200 sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0); 201 202 /* Restore the privileged uid. */ 203 restore_uid(); 204 205 /* Check for socket/bind/listen failure. */ 206 if (sock < 0) 207 goto authsock_err; 208 209 /* Allocate a channel for the authentication agent socket. */ 210 nc = channel_new(ssh, "auth socket", 211 SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, 212 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 213 0, "auth socket", 1); 214 nc->path = xstrdup(auth_sock_name); 215 return 1; 216 217 authsock_err: 218 free(auth_sock_name); 219 if (auth_sock_dir != NULL) { 220 rmdir(auth_sock_dir); 221 free(auth_sock_dir); 222 } 223 if (sock != -1) 224 close(sock); 225 auth_sock_name = NULL; 226 auth_sock_dir = NULL; 227 return 0; 228 } 229 230 static void 231 display_loginmsg(void) 232 { 233 if (buffer_len(&loginmsg) > 0) { 234 buffer_append(&loginmsg, "\0", 1); 235 printf("%s", (char *)buffer_ptr(&loginmsg)); 236 buffer_clear(&loginmsg); 237 } 238 } 239 240 static void 241 prepare_auth_info_file(struct passwd *pw, struct sshbuf *info) 242 { 243 int fd = -1, success = 0; 244 245 if (!options.expose_userauth_info || info == NULL) 246 return; 247 248 temporarily_use_uid(pw); 249 auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX"); 250 if ((fd = mkstemp(auth_info_file)) == -1) { 251 error("%s: mkstemp: %s", __func__, strerror(errno)); 252 goto out; 253 } 254 if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info), 255 sshbuf_len(info)) != sshbuf_len(info)) { 256 error("%s: write: %s", __func__, strerror(errno)); 257 goto out; 258 } 259 if (close(fd) != 0) { 260 error("%s: close: %s", __func__, strerror(errno)); 261 goto out; 262 } 263 success = 1; 264 out: 265 if (!success) { 266 if (fd != -1) 267 close(fd); 268 free(auth_info_file); 269 auth_info_file = NULL; 270 } 271 restore_uid(); 272 } 273 274 static void 275 set_fwdpermit_from_authopts(struct ssh *ssh, const struct sshauthopt *opts) 276 { 277 char *tmp, *cp, *host; 278 int port; 279 size_t i; 280 281 if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0) { 282 channel_clear_permission(ssh, FORWARD_USER, FORWARD_LOCAL); 283 for (i = 0; i < auth_opts->npermitopen; i++) { 284 tmp = cp = xstrdup(auth_opts->permitopen[i]); 285 /* This shouldn't fail as it has already been checked */ 286 if ((host = hpdelim(&cp)) == NULL) 287 fatal("%s: internal error: hpdelim", __func__); 288 host = cleanhostname(host); 289 if (cp == NULL || (port = permitopen_port(cp)) < 0) 290 fatal("%s: internal error: permitopen port", 291 __func__); 292 channel_add_permission(ssh, 293 FORWARD_USER, FORWARD_LOCAL, host, port); 294 free(tmp); 295 } 296 } 297 if ((options.allow_tcp_forwarding & FORWARD_REMOTE) != 0) { 298 channel_clear_permission(ssh, FORWARD_USER, FORWARD_REMOTE); 299 for (i = 0; i < auth_opts->npermitlisten; i++) { 300 tmp = cp = xstrdup(auth_opts->permitlisten[i]); 301 /* This shouldn't fail as it has already been checked */ 302 if ((host = hpdelim(&cp)) == NULL) 303 fatal("%s: internal error: hpdelim", __func__); 304 host = cleanhostname(host); 305 if (cp == NULL || (port = permitopen_port(cp)) < 0) 306 fatal("%s: internal error: permitlisten port", 307 __func__); 308 channel_add_permission(ssh, 309 FORWARD_USER, FORWARD_REMOTE, host, port); 310 free(tmp); 311 } 312 } 313 } 314 315 void 316 do_authenticated(struct ssh *ssh, Authctxt *authctxt) 317 { 318 setproctitle("%s", authctxt->pw->pw_name); 319 320 auth_log_authopts("active", auth_opts, 0); 321 322 /* setup the channel layer */ 323 /* XXX - streamlocal? */ 324 set_fwdpermit_from_authopts(ssh, auth_opts); 325 326 if (!auth_opts->permit_port_forwarding_flag || 327 options.disable_forwarding) { 328 channel_disable_admin(ssh, FORWARD_LOCAL); 329 channel_disable_admin(ssh, FORWARD_REMOTE); 330 } else { 331 if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0) 332 channel_disable_admin(ssh, FORWARD_LOCAL); 333 else 334 channel_permit_all(ssh, FORWARD_LOCAL); 335 if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0) 336 channel_disable_admin(ssh, FORWARD_REMOTE); 337 else 338 channel_permit_all(ssh, FORWARD_REMOTE); 339 } 340 auth_debug_send(); 341 342 prepare_auth_info_file(authctxt->pw, authctxt->session_info); 343 344 do_authenticated2(ssh, authctxt); 345 346 do_cleanup(ssh, authctxt); 347 } 348 349 /* Check untrusted xauth strings for metacharacters */ 350 static int 351 xauth_valid_string(const char *s) 352 { 353 size_t i; 354 355 for (i = 0; s[i] != '\0'; i++) { 356 if (!isalnum((u_char)s[i]) && 357 s[i] != '.' && s[i] != ':' && s[i] != '/' && 358 s[i] != '-' && s[i] != '_') 359 return 0; 360 } 361 return 1; 362 } 363 364 #define USE_PIPES 1 365 /* 366 * This is called to fork and execute a command when we have no tty. This 367 * will call do_child from the child, and server_loop from the parent after 368 * setting up file descriptors and such. 369 */ 370 int 371 do_exec_no_pty(struct ssh *ssh, Session *s, const char *command) 372 { 373 pid_t pid; 374 #ifdef USE_PIPES 375 int pin[2], pout[2], perr[2]; 376 377 if (s == NULL) 378 fatal("do_exec_no_pty: no session"); 379 380 /* Allocate pipes for communicating with the program. */ 381 if (pipe(pin) < 0) { 382 error("%s: pipe in: %.100s", __func__, strerror(errno)); 383 return -1; 384 } 385 if (pipe(pout) < 0) { 386 error("%s: pipe out: %.100s", __func__, strerror(errno)); 387 close(pin[0]); 388 close(pin[1]); 389 return -1; 390 } 391 if (pipe(perr) < 0) { 392 error("%s: pipe err: %.100s", __func__, 393 strerror(errno)); 394 close(pin[0]); 395 close(pin[1]); 396 close(pout[0]); 397 close(pout[1]); 398 return -1; 399 } 400 #else 401 int inout[2], err[2]; 402 403 if (s == NULL) 404 fatal("do_exec_no_pty: no session"); 405 406 /* Uses socket pairs to communicate with the program. */ 407 if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0) { 408 error("%s: socketpair #1: %.100s", __func__, strerror(errno)); 409 return -1; 410 } 411 if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) { 412 error("%s: socketpair #2: %.100s", __func__, 413 strerror(errno)); 414 close(inout[0]); 415 close(inout[1]); 416 return -1; 417 } 418 #endif 419 420 session_proctitle(s); 421 422 /* Fork the child. */ 423 switch ((pid = fork())) { 424 case -1: 425 error("%s: fork: %.100s", __func__, strerror(errno)); 426 #ifdef USE_PIPES 427 close(pin[0]); 428 close(pin[1]); 429 close(pout[0]); 430 close(pout[1]); 431 close(perr[0]); 432 close(perr[1]); 433 #else 434 close(inout[0]); 435 close(inout[1]); 436 close(err[0]); 437 close(err[1]); 438 #endif 439 return -1; 440 case 0: 441 is_child = 1; 442 443 /* 444 * Create a new session and process group since the 4.4BSD 445 * setlogin() affects the entire process group. 446 */ 447 if (setsid() < 0) 448 error("setsid failed: %.100s", strerror(errno)); 449 450 #ifdef USE_PIPES 451 /* 452 * Redirect stdin. We close the parent side of the socket 453 * pair, and make the child side the standard input. 454 */ 455 close(pin[1]); 456 if (dup2(pin[0], 0) < 0) 457 perror("dup2 stdin"); 458 close(pin[0]); 459 460 /* Redirect stdout. */ 461 close(pout[0]); 462 if (dup2(pout[1], 1) < 0) 463 perror("dup2 stdout"); 464 close(pout[1]); 465 466 /* Redirect stderr. */ 467 close(perr[0]); 468 if (dup2(perr[1], 2) < 0) 469 perror("dup2 stderr"); 470 close(perr[1]); 471 #else 472 /* 473 * Redirect stdin, stdout, and stderr. Stdin and stdout will 474 * use the same socket, as some programs (particularly rdist) 475 * seem to depend on it. 476 */ 477 close(inout[1]); 478 close(err[1]); 479 if (dup2(inout[0], 0) < 0) /* stdin */ 480 perror("dup2 stdin"); 481 if (dup2(inout[0], 1) < 0) /* stdout (same as stdin) */ 482 perror("dup2 stdout"); 483 close(inout[0]); 484 if (dup2(err[0], 2) < 0) /* stderr */ 485 perror("dup2 stderr"); 486 close(err[0]); 487 #endif 488 489 /* Do processing for the child (exec command etc). */ 490 do_child(ssh, s, command); 491 /* NOTREACHED */ 492 default: 493 break; 494 } 495 496 s->pid = pid; 497 /* Set interactive/non-interactive mode. */ 498 packet_set_interactive(s->display != NULL, 499 options.ip_qos_interactive, options.ip_qos_bulk); 500 501 #ifdef USE_PIPES 502 /* We are the parent. Close the child sides of the pipes. */ 503 close(pin[0]); 504 close(pout[1]); 505 close(perr[1]); 506 507 session_set_fds(ssh, s, pin[1], pout[0], perr[0], 508 s->is_subsystem, 0); 509 #else 510 /* We are the parent. Close the child sides of the socket pairs. */ 511 close(inout[0]); 512 close(err[0]); 513 514 /* 515 * Enter the interactive session. Note: server_loop must be able to 516 * handle the case that fdin and fdout are the same. 517 */ 518 session_set_fds(s, inout[1], inout[1], err[1], 519 s->is_subsystem, 0); 520 #endif 521 return 0; 522 } 523 524 /* 525 * This is called to fork and execute a command when we have a tty. This 526 * will call do_child from the child, and server_loop from the parent after 527 * setting up file descriptors, controlling tty, updating wtmp, utmp, 528 * lastlog, and other such operations. 529 */ 530 int 531 do_exec_pty(struct ssh *ssh, Session *s, const char *command) 532 { 533 int fdout, ptyfd, ttyfd, ptymaster; 534 pid_t pid; 535 536 if (s == NULL) 537 fatal("do_exec_pty: no session"); 538 ptyfd = s->ptyfd; 539 ttyfd = s->ttyfd; 540 541 /* 542 * Create another descriptor of the pty master side for use as the 543 * standard input. We could use the original descriptor, but this 544 * simplifies code in server_loop. The descriptor is bidirectional. 545 * Do this before forking (and cleanup in the child) so as to 546 * detect and gracefully fail out-of-fd conditions. 547 */ 548 if ((fdout = dup(ptyfd)) < 0) { 549 error("%s: dup #1: %s", __func__, strerror(errno)); 550 close(ttyfd); 551 close(ptyfd); 552 return -1; 553 } 554 /* we keep a reference to the pty master */ 555 if ((ptymaster = dup(ptyfd)) < 0) { 556 error("%s: dup #2: %s", __func__, strerror(errno)); 557 close(ttyfd); 558 close(ptyfd); 559 close(fdout); 560 return -1; 561 } 562 563 /* Fork the child. */ 564 switch ((pid = fork())) { 565 case -1: 566 error("%s: fork: %.100s", __func__, strerror(errno)); 567 close(fdout); 568 close(ptymaster); 569 close(ttyfd); 570 close(ptyfd); 571 return -1; 572 case 0: 573 is_child = 1; 574 575 close(fdout); 576 close(ptymaster); 577 578 /* Close the master side of the pseudo tty. */ 579 close(ptyfd); 580 581 /* Make the pseudo tty our controlling tty. */ 582 pty_make_controlling_tty(&ttyfd, s->tty); 583 584 /* Redirect stdin/stdout/stderr from the pseudo tty. */ 585 if (dup2(ttyfd, 0) < 0) 586 error("dup2 stdin: %s", strerror(errno)); 587 if (dup2(ttyfd, 1) < 0) 588 error("dup2 stdout: %s", strerror(errno)); 589 if (dup2(ttyfd, 2) < 0) 590 error("dup2 stderr: %s", strerror(errno)); 591 592 /* Close the extra descriptor for the pseudo tty. */ 593 close(ttyfd); 594 595 /* record login, etc. similar to login(1) */ 596 do_login(ssh, s, command); 597 598 /* 599 * Do common processing for the child, such as execing 600 * the command. 601 */ 602 do_child(ssh, s, command); 603 /* NOTREACHED */ 604 default: 605 break; 606 } 607 s->pid = pid; 608 609 /* Parent. Close the slave side of the pseudo tty. */ 610 close(ttyfd); 611 612 /* Enter interactive session. */ 613 s->ptymaster = ptymaster; 614 packet_set_interactive(1, 615 options.ip_qos_interactive, options.ip_qos_bulk); 616 session_set_fds(ssh, s, ptyfd, fdout, -1, 1, 1); 617 return 0; 618 } 619 620 /* 621 * This is called to fork and execute a command. If another command is 622 * to be forced, execute that instead. 623 */ 624 int 625 do_exec(struct ssh *ssh, Session *s, const char *command) 626 { 627 int ret; 628 const char *forced = NULL, *tty = NULL; 629 char session_type[1024]; 630 631 if (options.adm_forced_command) { 632 original_command = command; 633 command = options.adm_forced_command; 634 forced = "(config)"; 635 } else if (auth_opts->force_command != NULL) { 636 original_command = command; 637 command = auth_opts->force_command; 638 forced = "(key-option)"; 639 } 640 if (forced != NULL) { 641 if (IS_INTERNAL_SFTP(command)) { 642 s->is_subsystem = s->is_subsystem ? 643 SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR; 644 } else if (s->is_subsystem) 645 s->is_subsystem = SUBSYSTEM_EXT; 646 snprintf(session_type, sizeof(session_type), 647 "forced-command %s '%.900s'", forced, command); 648 } else if (s->is_subsystem) { 649 snprintf(session_type, sizeof(session_type), 650 "subsystem '%.900s'", s->subsys); 651 } else if (command == NULL) { 652 snprintf(session_type, sizeof(session_type), "shell"); 653 } else { 654 /* NB. we don't log unforced commands to preserve privacy */ 655 snprintf(session_type, sizeof(session_type), "command"); 656 } 657 658 if (s->ttyfd != -1) { 659 tty = s->tty; 660 if (strncmp(tty, "/dev/", 5) == 0) 661 tty += 5; 662 } 663 664 verbose("Starting session: %s%s%s for %s from %.200s port %d id %d", 665 session_type, 666 tty == NULL ? "" : " on ", 667 tty == NULL ? "" : tty, 668 s->pw->pw_name, 669 ssh_remote_ipaddr(ssh), 670 ssh_remote_port(ssh), 671 s->self); 672 673 #ifdef GSSAPI 674 if (options.gss_authentication) { 675 temporarily_use_uid(s->pw); 676 ssh_gssapi_storecreds(); 677 restore_uid(); 678 } 679 #endif 680 if (s->ttyfd != -1) 681 ret = do_exec_pty(ssh, s, command); 682 else 683 ret = do_exec_no_pty(ssh, s, command); 684 685 original_command = NULL; 686 687 /* 688 * Clear loginmsg: it's the child's responsibility to display 689 * it to the user, otherwise multiple sessions may accumulate 690 * multiple copies of the login messages. 691 */ 692 buffer_clear(&loginmsg); 693 694 return ret; 695 } 696 697 698 /* administrative, login(1)-like work */ 699 void 700 do_login(struct ssh *ssh, Session *s, const char *command) 701 { 702 socklen_t fromlen; 703 struct sockaddr_storage from; 704 struct passwd * pw = s->pw; 705 pid_t pid = getpid(); 706 707 /* 708 * Get IP address of client. If the connection is not a socket, let 709 * the address be 0.0.0.0. 710 */ 711 memset(&from, 0, sizeof(from)); 712 fromlen = sizeof(from); 713 if (packet_connection_is_on_socket()) { 714 if (getpeername(packet_get_connection_in(), 715 (struct sockaddr *)&from, &fromlen) < 0) { 716 debug("getpeername: %.100s", strerror(errno)); 717 cleanup_exit(255); 718 } 719 } 720 721 /* Record that there was a login on that tty from the remote host. */ 722 if (!use_privsep) 723 record_login(pid, s->tty, pw->pw_name, pw->pw_uid, 724 session_get_remote_name_or_ip(ssh, utmp_len, 725 options.use_dns), 726 (struct sockaddr *)&from, fromlen); 727 728 if (check_quietlogin(s, command)) 729 return; 730 731 display_loginmsg(); 732 733 do_motd(); 734 } 735 736 /* 737 * Display the message of the day. 738 */ 739 void 740 do_motd(void) 741 { 742 FILE *f; 743 char buf[256]; 744 745 if (options.print_motd) { 746 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", 747 "/etc/motd"), "r"); 748 if (f) { 749 while (fgets(buf, sizeof(buf), f)) 750 fputs(buf, stdout); 751 fclose(f); 752 } 753 } 754 } 755 756 757 /* 758 * Check for quiet login, either .hushlogin or command given. 759 */ 760 int 761 check_quietlogin(Session *s, const char *command) 762 { 763 char buf[256]; 764 struct passwd *pw = s->pw; 765 struct stat st; 766 767 /* Return 1 if .hushlogin exists or a command given. */ 768 if (command != NULL) 769 return 1; 770 snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); 771 if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) 772 return 1; 773 return 0; 774 } 775 776 /* 777 * Reads environment variables from the given file and adds/overrides them 778 * into the environment. If the file does not exist, this does nothing. 779 * Otherwise, it must consist of empty lines, comments (line starts with '#') 780 * and assignments of the form name=value. No other forms are allowed. 781 */ 782 static void 783 read_environment_file(char ***env, u_int *envsize, 784 const char *filename) 785 { 786 FILE *f; 787 char *line = NULL, *cp, *value; 788 size_t linesize = 0; 789 u_int lineno = 0; 790 791 f = fopen(filename, "r"); 792 if (!f) 793 return; 794 795 while (getline(&line, &linesize, f) != -1) { 796 if (++lineno > 1000) 797 fatal("Too many lines in environment file %s", filename); 798 for (cp = line; *cp == ' ' || *cp == '\t'; cp++) 799 ; 800 if (!*cp || *cp == '#' || *cp == '\n') 801 continue; 802 803 cp[strcspn(cp, "\n")] = '\0'; 804 805 value = strchr(cp, '='); 806 if (value == NULL) { 807 fprintf(stderr, "Bad line %u in %.100s\n", lineno, 808 filename); 809 continue; 810 } 811 /* 812 * Replace the equals sign by nul, and advance value to 813 * the value string. 814 */ 815 *value = '\0'; 816 value++; 817 child_set_env(env, envsize, cp, value); 818 } 819 free(line); 820 fclose(f); 821 } 822 823 static char ** 824 do_setup_env(struct ssh *ssh, Session *s, const char *shell) 825 { 826 char buf[256]; 827 size_t n; 828 u_int i, envsize; 829 char *ocp, *cp, *value, **env, *laddr; 830 struct passwd *pw = s->pw; 831 832 /* Initialize the environment. */ 833 envsize = 100; 834 env = xcalloc(envsize, sizeof(char *)); 835 env[0] = NULL; 836 837 #ifdef GSSAPI 838 /* Allow any GSSAPI methods that we've used to alter 839 * the childs environment as they see fit 840 */ 841 ssh_gssapi_do_child(&env, &envsize); 842 #endif 843 844 /* Set basic environment. */ 845 for (i = 0; i < s->num_env; i++) 846 child_set_env(&env, &envsize, s->env[i].name, s->env[i].val); 847 848 child_set_env(&env, &envsize, "USER", pw->pw_name); 849 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); 850 child_set_env(&env, &envsize, "HOME", pw->pw_dir); 851 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) 852 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); 853 else 854 child_set_env(&env, &envsize, "PATH", getenv("PATH")); 855 856 snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name); 857 child_set_env(&env, &envsize, "MAIL", buf); 858 859 /* Normal systems set SHELL by default. */ 860 child_set_env(&env, &envsize, "SHELL", shell); 861 862 if (getenv("TZ")) 863 child_set_env(&env, &envsize, "TZ", getenv("TZ")); 864 if (s->term) 865 child_set_env(&env, &envsize, "TERM", s->term); 866 if (s->display) 867 child_set_env(&env, &envsize, "DISPLAY", s->display); 868 #ifdef KRB5 869 if (s->authctxt->krb5_ticket_file) 870 child_set_env(&env, &envsize, "KRB5CCNAME", 871 s->authctxt->krb5_ticket_file); 872 #endif 873 if (auth_sock_name != NULL) 874 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, 875 auth_sock_name); 876 877 878 /* Set custom environment options from pubkey authentication. */ 879 if (options.permit_user_env) { 880 for (n = 0 ; n < auth_opts->nenv; n++) { 881 ocp = xstrdup(auth_opts->env[n]); 882 cp = strchr(ocp, '='); 883 if (*cp == '=') { 884 *cp = '\0'; 885 child_set_env(&env, &envsize, ocp, cp + 1); 886 } 887 free(ocp); 888 } 889 } 890 891 /* read $HOME/.ssh/environment. */ 892 if (options.permit_user_env) { 893 snprintf(buf, sizeof buf, "%.200s/.ssh/environment", 894 pw->pw_dir); 895 read_environment_file(&env, &envsize, buf); 896 } 897 898 /* Environment specified by admin */ 899 for (i = 0; i < options.num_setenv; i++) { 900 cp = xstrdup(options.setenv[i]); 901 if ((value = strchr(cp, '=')) == NULL) { 902 /* shouldn't happen; vars are checked in servconf.c */ 903 fatal("Invalid config SetEnv: %s", options.setenv[i]); 904 } 905 *value++ = '\0'; 906 child_set_env(&env, &envsize, cp, value); 907 } 908 909 /* SSH_CLIENT deprecated */ 910 snprintf(buf, sizeof buf, "%.50s %d %d", 911 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), 912 ssh_local_port(ssh)); 913 child_set_env(&env, &envsize, "SSH_CLIENT", buf); 914 915 laddr = get_local_ipaddr(packet_get_connection_in()); 916 snprintf(buf, sizeof buf, "%.50s %d %.50s %d", 917 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), 918 laddr, ssh_local_port(ssh)); 919 free(laddr); 920 child_set_env(&env, &envsize, "SSH_CONNECTION", buf); 921 922 if (tun_fwd_ifnames != NULL) 923 child_set_env(&env, &envsize, "SSH_TUNNEL", tun_fwd_ifnames); 924 if (auth_info_file != NULL) 925 child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file); 926 if (s->ttyfd != -1) 927 child_set_env(&env, &envsize, "SSH_TTY", s->tty); 928 if (original_command) 929 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", 930 original_command); 931 932 if (debug_flag) { 933 /* dump the environment */ 934 fprintf(stderr, "Environment:\n"); 935 for (i = 0; env[i]; i++) 936 fprintf(stderr, " %.200s\n", env[i]); 937 } 938 return env; 939 } 940 941 /* 942 * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found 943 * first in this order). 944 */ 945 static void 946 do_rc_files(struct ssh *ssh, Session *s, const char *shell) 947 { 948 FILE *f = NULL; 949 char cmd[1024]; 950 int do_xauth; 951 struct stat st; 952 953 do_xauth = 954 s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; 955 956 /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */ 957 if (!s->is_subsystem && options.adm_forced_command == NULL && 958 auth_opts->permit_user_rc && options.permit_user_rc && 959 stat(_PATH_SSH_USER_RC, &st) >= 0) { 960 snprintf(cmd, sizeof cmd, "%s -c '%s %s'", 961 shell, _PATH_BSHELL, _PATH_SSH_USER_RC); 962 if (debug_flag) 963 fprintf(stderr, "Running %s\n", cmd); 964 f = popen(cmd, "w"); 965 if (f) { 966 if (do_xauth) 967 fprintf(f, "%s %s\n", s->auth_proto, 968 s->auth_data); 969 pclose(f); 970 } else 971 fprintf(stderr, "Could not run %s\n", 972 _PATH_SSH_USER_RC); 973 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { 974 if (debug_flag) 975 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, 976 _PATH_SSH_SYSTEM_RC); 977 f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); 978 if (f) { 979 if (do_xauth) 980 fprintf(f, "%s %s\n", s->auth_proto, 981 s->auth_data); 982 pclose(f); 983 } else 984 fprintf(stderr, "Could not run %s\n", 985 _PATH_SSH_SYSTEM_RC); 986 } else if (do_xauth && options.xauth_location != NULL) { 987 /* Add authority data to .Xauthority if appropriate. */ 988 if (debug_flag) { 989 fprintf(stderr, 990 "Running %.500s remove %.100s\n", 991 options.xauth_location, s->auth_display); 992 fprintf(stderr, 993 "%.500s add %.100s %.100s %.100s\n", 994 options.xauth_location, s->auth_display, 995 s->auth_proto, s->auth_data); 996 } 997 snprintf(cmd, sizeof cmd, "%s -q -", 998 options.xauth_location); 999 f = popen(cmd, "w"); 1000 if (f) { 1001 fprintf(f, "remove %s\n", 1002 s->auth_display); 1003 fprintf(f, "add %s %s %s\n", 1004 s->auth_display, s->auth_proto, 1005 s->auth_data); 1006 pclose(f); 1007 } else { 1008 fprintf(stderr, "Could not run %s\n", 1009 cmd); 1010 } 1011 } 1012 } 1013 1014 static void 1015 do_nologin(struct passwd *pw) 1016 { 1017 FILE *f = NULL; 1018 char buf[1024], *nl, *def_nl = _PATH_NOLOGIN; 1019 struct stat sb; 1020 1021 if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0) 1022 return; 1023 nl = login_getcapstr(lc, "nologin", def_nl, def_nl); 1024 1025 if (stat(nl, &sb) == -1) { 1026 if (nl != def_nl) 1027 free(nl); 1028 return; 1029 } 1030 1031 /* /etc/nologin exists. Print its contents if we can and exit. */ 1032 logit("User %.100s not allowed because %s exists", pw->pw_name, nl); 1033 if ((f = fopen(nl, "r")) != NULL) { 1034 while (fgets(buf, sizeof(buf), f)) 1035 fputs(buf, stderr); 1036 fclose(f); 1037 } 1038 exit(254); 1039 } 1040 1041 /* 1042 * Chroot into a directory after checking it for safety: all path components 1043 * must be root-owned directories with strict permissions. 1044 */ 1045 static void 1046 safely_chroot(const char *path, uid_t uid) 1047 { 1048 const char *cp; 1049 char component[PATH_MAX]; 1050 struct stat st; 1051 1052 if (*path != '/') 1053 fatal("chroot path does not begin at root"); 1054 if (strlen(path) >= sizeof(component)) 1055 fatal("chroot path too long"); 1056 1057 /* 1058 * Descend the path, checking that each component is a 1059 * root-owned directory with strict permissions. 1060 */ 1061 for (cp = path; cp != NULL;) { 1062 if ((cp = strchr(cp, '/')) == NULL) 1063 strlcpy(component, path, sizeof(component)); 1064 else { 1065 cp++; 1066 memcpy(component, path, cp - path); 1067 component[cp - path] = '\0'; 1068 } 1069 1070 debug3("%s: checking '%s'", __func__, component); 1071 1072 if (stat(component, &st) != 0) 1073 fatal("%s: stat(\"%s\"): %s", __func__, 1074 component, strerror(errno)); 1075 if (st.st_uid != 0 || (st.st_mode & 022) != 0) 1076 fatal("bad ownership or modes for chroot " 1077 "directory %s\"%s\"", 1078 cp == NULL ? "" : "component ", component); 1079 if (!S_ISDIR(st.st_mode)) 1080 fatal("chroot path %s\"%s\" is not a directory", 1081 cp == NULL ? "" : "component ", component); 1082 1083 } 1084 1085 if (chdir(path) == -1) 1086 fatal("Unable to chdir to chroot path \"%s\": " 1087 "%s", path, strerror(errno)); 1088 if (chroot(path) == -1) 1089 fatal("chroot(\"%s\"): %s", path, strerror(errno)); 1090 if (chdir("/") == -1) 1091 fatal("%s: chdir(/) after chroot: %s", 1092 __func__, strerror(errno)); 1093 verbose("Changed root directory to \"%s\"", path); 1094 } 1095 1096 /* Set login name, uid, gid, and groups. */ 1097 void 1098 do_setusercontext(struct passwd *pw) 1099 { 1100 char uidstr[32], *chroot_path, *tmp; 1101 1102 if (getuid() == 0 || geteuid() == 0) { 1103 /* Prepare groups */ 1104 if (setusercontext(lc, pw, pw->pw_uid, 1105 (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) { 1106 perror("unable to set user context"); 1107 exit(1); 1108 } 1109 1110 if (!in_chroot && options.chroot_directory != NULL && 1111 strcasecmp(options.chroot_directory, "none") != 0) { 1112 tmp = tilde_expand_filename(options.chroot_directory, 1113 pw->pw_uid); 1114 snprintf(uidstr, sizeof(uidstr), "%llu", 1115 (unsigned long long)pw->pw_uid); 1116 chroot_path = percent_expand(tmp, "h", pw->pw_dir, 1117 "u", pw->pw_name, "U", uidstr, (char *)NULL); 1118 safely_chroot(chroot_path, pw->pw_uid); 1119 free(tmp); 1120 free(chroot_path); 1121 /* Make sure we don't attempt to chroot again */ 1122 free(options.chroot_directory); 1123 options.chroot_directory = NULL; 1124 in_chroot = 1; 1125 } 1126 1127 /* Set UID */ 1128 if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) { 1129 perror("unable to set user context (setuser)"); 1130 exit(1); 1131 } 1132 } else if (options.chroot_directory != NULL && 1133 strcasecmp(options.chroot_directory, "none") != 0) { 1134 fatal("server lacks privileges to chroot to ChrootDirectory"); 1135 } 1136 1137 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) 1138 fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); 1139 } 1140 1141 static void 1142 do_pwchange(Session *s) 1143 { 1144 fflush(NULL); 1145 fprintf(stderr, "WARNING: Your password has expired.\n"); 1146 if (s->ttyfd != -1) { 1147 fprintf(stderr, 1148 "You must change your password now and login again!\n"); 1149 execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); 1150 perror("passwd"); 1151 } else { 1152 fprintf(stderr, 1153 "Password change required but no TTY available.\n"); 1154 } 1155 exit(1); 1156 } 1157 1158 static void 1159 child_close_fds(struct ssh *ssh) 1160 { 1161 extern int auth_sock; 1162 1163 if (auth_sock != -1) { 1164 close(auth_sock); 1165 auth_sock = -1; 1166 } 1167 1168 if (packet_get_connection_in() == packet_get_connection_out()) 1169 close(packet_get_connection_in()); 1170 else { 1171 close(packet_get_connection_in()); 1172 close(packet_get_connection_out()); 1173 } 1174 /* 1175 * Close all descriptors related to channels. They will still remain 1176 * open in the parent. 1177 */ 1178 /* XXX better use close-on-exec? -markus */ 1179 channel_close_all(ssh); 1180 1181 /* 1182 * Close any extra file descriptors. Note that there may still be 1183 * descriptors left by system functions. They will be closed later. 1184 */ 1185 endpwent(); 1186 1187 /* 1188 * Close any extra open file descriptors so that we don't have them 1189 * hanging around in clients. Note that we want to do this after 1190 * initgroups, because at least on Solaris 2.3 it leaves file 1191 * descriptors open. 1192 */ 1193 closefrom(STDERR_FILENO + 1); 1194 } 1195 1196 /* 1197 * Performs common processing for the child, such as setting up the 1198 * environment, closing extra file descriptors, setting the user and group 1199 * ids, and executing the command or shell. 1200 */ 1201 #define ARGV_MAX 10 1202 void 1203 do_child(struct ssh *ssh, Session *s, const char *command) 1204 { 1205 extern char **environ; 1206 char **env; 1207 char *argv[ARGV_MAX]; 1208 const char *shell, *shell0; 1209 struct passwd *pw = s->pw; 1210 int r = 0; 1211 1212 /* remove hostkey from the child's memory */ 1213 destroy_sensitive_data(); 1214 packet_clear_keys(); 1215 1216 /* Force a password change */ 1217 if (s->authctxt->force_pwchange) { 1218 do_setusercontext(pw); 1219 child_close_fds(ssh); 1220 do_pwchange(s); 1221 exit(1); 1222 } 1223 1224 /* 1225 * Login(1) does this as well, and it needs uid 0 for the "-h" 1226 * switch, so we let login(1) to this for us. 1227 */ 1228 do_nologin(pw); 1229 do_setusercontext(pw); 1230 1231 /* 1232 * Get the shell from the password data. An empty shell field is 1233 * legal, and means /bin/sh. 1234 */ 1235 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; 1236 1237 /* 1238 * Make sure $SHELL points to the shell from the password file, 1239 * even if shell is overridden from login.conf 1240 */ 1241 env = do_setup_env(ssh, s, shell); 1242 1243 shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); 1244 1245 /* 1246 * Close the connection descriptors; note that this is the child, and 1247 * the server will still have the socket open, and it is important 1248 * that we do not shutdown it. Note that the descriptors cannot be 1249 * closed before building the environment, as we call 1250 * ssh_remote_ipaddr there. 1251 */ 1252 child_close_fds(ssh); 1253 1254 /* 1255 * Must take new environment into use so that .ssh/rc, 1256 * /etc/ssh/sshrc and xauth are run in the proper environment. 1257 */ 1258 environ = env; 1259 1260 #ifdef KRB5 1261 /* 1262 * At this point, we check to see if AFS is active and if we have 1263 * a valid Kerberos 5 TGT. If so, it seems like a good idea to see 1264 * if we can (and need to) extend the ticket into an AFS token. If 1265 * we don't do this, we run into potential problems if the user's 1266 * home directory is in AFS and it's not world-readable. 1267 */ 1268 1269 if (options.kerberos_get_afs_token && k_hasafs() && 1270 (s->authctxt->krb5_ctx != NULL)) { 1271 char cell[64]; 1272 1273 debug("Getting AFS token"); 1274 1275 k_setpag(); 1276 1277 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) 1278 krb5_afslog(s->authctxt->krb5_ctx, 1279 s->authctxt->krb5_fwd_ccache, cell, NULL); 1280 1281 krb5_afslog_home(s->authctxt->krb5_ctx, 1282 s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); 1283 } 1284 #endif 1285 1286 /* Change current directory to the user's home directory. */ 1287 if (chdir(pw->pw_dir) < 0) { 1288 /* Suppress missing homedir warning for chroot case */ 1289 r = login_getcapbool(lc, "requirehome", 0); 1290 if (r || !in_chroot) { 1291 fprintf(stderr, "Could not chdir to home " 1292 "directory %s: %s\n", pw->pw_dir, 1293 strerror(errno)); 1294 } 1295 if (r) 1296 exit(1); 1297 } 1298 1299 closefrom(STDERR_FILENO + 1); 1300 1301 do_rc_files(ssh, s, shell); 1302 1303 /* restore SIGPIPE for child */ 1304 signal(SIGPIPE, SIG_DFL); 1305 1306 if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) { 1307 printf("This service allows sftp connections only.\n"); 1308 fflush(NULL); 1309 exit(1); 1310 } else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) { 1311 extern int optind, optreset; 1312 int i; 1313 char *p, *args; 1314 1315 setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME); 1316 args = xstrdup(command ? command : "sftp-server"); 1317 for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " "))) 1318 if (i < ARGV_MAX - 1) 1319 argv[i++] = p; 1320 argv[i] = NULL; 1321 optind = optreset = 1; 1322 __progname = argv[0]; 1323 exit(sftp_server_main(i, argv, s->pw)); 1324 } 1325 1326 fflush(NULL); 1327 1328 /* Get the last component of the shell name. */ 1329 if ((shell0 = strrchr(shell, '/')) != NULL) 1330 shell0++; 1331 else 1332 shell0 = shell; 1333 1334 /* 1335 * If we have no command, execute the shell. In this case, the shell 1336 * name to be passed in argv[0] is preceded by '-' to indicate that 1337 * this is a login shell. 1338 */ 1339 if (!command) { 1340 char argv0[256]; 1341 1342 /* Start the shell. Set initial character to '-'. */ 1343 argv0[0] = '-'; 1344 1345 if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) 1346 >= sizeof(argv0) - 1) { 1347 errno = EINVAL; 1348 perror(shell); 1349 exit(1); 1350 } 1351 1352 /* Execute the shell. */ 1353 argv[0] = argv0; 1354 argv[1] = NULL; 1355 execve(shell, argv, env); 1356 1357 /* Executing the shell failed. */ 1358 perror(shell); 1359 exit(1); 1360 } 1361 /* 1362 * Execute the command using the user's shell. This uses the -c 1363 * option to execute the command. 1364 */ 1365 argv[0] = (char *) shell0; 1366 argv[1] = "-c"; 1367 argv[2] = (char *) command; 1368 argv[3] = NULL; 1369 execve(shell, argv, env); 1370 perror(shell); 1371 exit(1); 1372 } 1373 1374 void 1375 session_unused(int id) 1376 { 1377 debug3("%s: session id %d unused", __func__, id); 1378 if (id >= options.max_sessions || 1379 id >= sessions_nalloc) { 1380 fatal("%s: insane session id %d (max %d nalloc %d)", 1381 __func__, id, options.max_sessions, sessions_nalloc); 1382 } 1383 memset(&sessions[id], 0, sizeof(*sessions)); 1384 sessions[id].self = id; 1385 sessions[id].used = 0; 1386 sessions[id].chanid = -1; 1387 sessions[id].ptyfd = -1; 1388 sessions[id].ttyfd = -1; 1389 sessions[id].ptymaster = -1; 1390 sessions[id].x11_chanids = NULL; 1391 sessions[id].next_unused = sessions_first_unused; 1392 sessions_first_unused = id; 1393 } 1394 1395 Session * 1396 session_new(void) 1397 { 1398 Session *s, *tmp; 1399 1400 if (sessions_first_unused == -1) { 1401 if (sessions_nalloc >= options.max_sessions) 1402 return NULL; 1403 debug2("%s: allocate (allocated %d max %d)", 1404 __func__, sessions_nalloc, options.max_sessions); 1405 tmp = xrecallocarray(sessions, sessions_nalloc, 1406 sessions_nalloc + 1, sizeof(*sessions)); 1407 if (tmp == NULL) { 1408 error("%s: cannot allocate %d sessions", 1409 __func__, sessions_nalloc + 1); 1410 return NULL; 1411 } 1412 sessions = tmp; 1413 session_unused(sessions_nalloc++); 1414 } 1415 1416 if (sessions_first_unused >= sessions_nalloc || 1417 sessions_first_unused < 0) { 1418 fatal("%s: insane first_unused %d max %d nalloc %d", 1419 __func__, sessions_first_unused, options.max_sessions, 1420 sessions_nalloc); 1421 } 1422 1423 s = &sessions[sessions_first_unused]; 1424 if (s->used) { 1425 fatal("%s: session %d already used", 1426 __func__, sessions_first_unused); 1427 } 1428 sessions_first_unused = s->next_unused; 1429 s->used = 1; 1430 s->next_unused = -1; 1431 debug("session_new: session %d", s->self); 1432 1433 return s; 1434 } 1435 1436 static void 1437 session_dump(void) 1438 { 1439 int i; 1440 for (i = 0; i < sessions_nalloc; i++) { 1441 Session *s = &sessions[i]; 1442 1443 debug("dump: used %d next_unused %d session %d %p " 1444 "channel %d pid %ld", 1445 s->used, 1446 s->next_unused, 1447 s->self, 1448 s, 1449 s->chanid, 1450 (long)s->pid); 1451 } 1452 } 1453 1454 int 1455 session_open(Authctxt *authctxt, int chanid) 1456 { 1457 Session *s = session_new(); 1458 debug("session_open: channel %d", chanid); 1459 if (s == NULL) { 1460 error("no more sessions"); 1461 return 0; 1462 } 1463 s->authctxt = authctxt; 1464 s->pw = authctxt->pw; 1465 if (s->pw == NULL || !authctxt->valid) 1466 fatal("no user for session %d", s->self); 1467 debug("session_open: session %d: link with channel %d", s->self, chanid); 1468 s->chanid = chanid; 1469 return 1; 1470 } 1471 1472 Session * 1473 session_by_tty(char *tty) 1474 { 1475 int i; 1476 for (i = 0; i < sessions_nalloc; i++) { 1477 Session *s = &sessions[i]; 1478 if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { 1479 debug("session_by_tty: session %d tty %s", i, tty); 1480 return s; 1481 } 1482 } 1483 debug("session_by_tty: unknown tty %.100s", tty); 1484 session_dump(); 1485 return NULL; 1486 } 1487 1488 static Session * 1489 session_by_channel(int id) 1490 { 1491 int i; 1492 for (i = 0; i < sessions_nalloc; i++) { 1493 Session *s = &sessions[i]; 1494 if (s->used && s->chanid == id) { 1495 debug("session_by_channel: session %d channel %d", 1496 i, id); 1497 return s; 1498 } 1499 } 1500 debug("session_by_channel: unknown channel %d", id); 1501 session_dump(); 1502 return NULL; 1503 } 1504 1505 static Session * 1506 session_by_x11_channel(int id) 1507 { 1508 int i, j; 1509 1510 for (i = 0; i < sessions_nalloc; i++) { 1511 Session *s = &sessions[i]; 1512 1513 if (s->x11_chanids == NULL || !s->used) 1514 continue; 1515 for (j = 0; s->x11_chanids[j] != -1; j++) { 1516 if (s->x11_chanids[j] == id) { 1517 debug("session_by_x11_channel: session %d " 1518 "channel %d", s->self, id); 1519 return s; 1520 } 1521 } 1522 } 1523 debug("session_by_x11_channel: unknown channel %d", id); 1524 session_dump(); 1525 return NULL; 1526 } 1527 1528 static Session * 1529 session_by_pid(pid_t pid) 1530 { 1531 int i; 1532 debug("session_by_pid: pid %ld", (long)pid); 1533 for (i = 0; i < sessions_nalloc; i++) { 1534 Session *s = &sessions[i]; 1535 if (s->used && s->pid == pid) 1536 return s; 1537 } 1538 error("session_by_pid: unknown pid %ld", (long)pid); 1539 session_dump(); 1540 return NULL; 1541 } 1542 1543 static int 1544 session_window_change_req(struct ssh *ssh, Session *s) 1545 { 1546 s->col = packet_get_int(); 1547 s->row = packet_get_int(); 1548 s->xpixel = packet_get_int(); 1549 s->ypixel = packet_get_int(); 1550 packet_check_eom(); 1551 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); 1552 return 1; 1553 } 1554 1555 static int 1556 session_pty_req(struct ssh *ssh, Session *s) 1557 { 1558 u_int len; 1559 int n_bytes; 1560 1561 if (!auth_opts->permit_pty_flag || !options.permit_tty) { 1562 debug("Allocating a pty not permitted for this connection."); 1563 return 0; 1564 } 1565 if (s->ttyfd != -1) { 1566 packet_disconnect("Protocol error: you already have a pty."); 1567 return 0; 1568 } 1569 1570 s->term = packet_get_string(&len); 1571 s->col = packet_get_int(); 1572 s->row = packet_get_int(); 1573 s->xpixel = packet_get_int(); 1574 s->ypixel = packet_get_int(); 1575 1576 if (strcmp(s->term, "") == 0) { 1577 free(s->term); 1578 s->term = NULL; 1579 } 1580 1581 /* Allocate a pty and open it. */ 1582 debug("Allocating pty."); 1583 if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, 1584 sizeof(s->tty)))) { 1585 free(s->term); 1586 s->term = NULL; 1587 s->ptyfd = -1; 1588 s->ttyfd = -1; 1589 error("session_pty_req: session %d alloc failed", s->self); 1590 return 0; 1591 } 1592 debug("session_pty_req: session %d alloc %s", s->self, s->tty); 1593 1594 n_bytes = packet_remaining(); 1595 tty_parse_modes(s->ttyfd, &n_bytes); 1596 1597 if (!use_privsep) 1598 pty_setowner(s->pw, s->tty); 1599 1600 /* Set window size from the packet. */ 1601 pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); 1602 1603 packet_check_eom(); 1604 session_proctitle(s); 1605 return 1; 1606 } 1607 1608 static int 1609 session_subsystem_req(struct ssh *ssh, Session *s) 1610 { 1611 struct stat st; 1612 u_int len; 1613 int success = 0; 1614 char *prog, *cmd; 1615 u_int i; 1616 1617 s->subsys = packet_get_string(&len); 1618 packet_check_eom(); 1619 debug2("subsystem request for %.100s by user %s", s->subsys, 1620 s->pw->pw_name); 1621 1622 for (i = 0; i < options.num_subsystems; i++) { 1623 if (strcmp(s->subsys, options.subsystem_name[i]) == 0) { 1624 prog = options.subsystem_command[i]; 1625 cmd = options.subsystem_args[i]; 1626 if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) { 1627 s->is_subsystem = SUBSYSTEM_INT_SFTP; 1628 debug("subsystem: %s", prog); 1629 } else { 1630 if (stat(prog, &st) < 0) 1631 debug("subsystem: cannot stat %s: %s", 1632 prog, strerror(errno)); 1633 s->is_subsystem = SUBSYSTEM_EXT; 1634 debug("subsystem: exec() %s", cmd); 1635 } 1636 success = do_exec(ssh, s, cmd) == 0; 1637 break; 1638 } 1639 } 1640 1641 if (!success) 1642 logit("subsystem request for %.100s by user %s failed, " 1643 "subsystem not found", s->subsys, s->pw->pw_name); 1644 1645 return success; 1646 } 1647 1648 static int 1649 session_x11_req(struct ssh *ssh, Session *s) 1650 { 1651 int success; 1652 1653 if (s->auth_proto != NULL || s->auth_data != NULL) { 1654 error("session_x11_req: session %d: " 1655 "x11 forwarding already active", s->self); 1656 return 0; 1657 } 1658 s->single_connection = packet_get_char(); 1659 s->auth_proto = packet_get_string(NULL); 1660 s->auth_data = packet_get_string(NULL); 1661 s->screen = packet_get_int(); 1662 packet_check_eom(); 1663 1664 if (xauth_valid_string(s->auth_proto) && 1665 xauth_valid_string(s->auth_data)) 1666 success = session_setup_x11fwd(ssh, s); 1667 else { 1668 success = 0; 1669 error("Invalid X11 forwarding data"); 1670 } 1671 if (!success) { 1672 free(s->auth_proto); 1673 free(s->auth_data); 1674 s->auth_proto = NULL; 1675 s->auth_data = NULL; 1676 } 1677 return success; 1678 } 1679 1680 static int 1681 session_shell_req(struct ssh *ssh, Session *s) 1682 { 1683 packet_check_eom(); 1684 return do_exec(ssh, s, NULL) == 0; 1685 } 1686 1687 static int 1688 session_exec_req(struct ssh *ssh, Session *s) 1689 { 1690 u_int len, success; 1691 1692 char *command = packet_get_string(&len); 1693 packet_check_eom(); 1694 success = do_exec(ssh, s, command) == 0; 1695 free(command); 1696 return success; 1697 } 1698 1699 static int 1700 session_break_req(struct ssh *ssh, Session *s) 1701 { 1702 1703 packet_get_int(); /* ignored */ 1704 packet_check_eom(); 1705 1706 if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) < 0) 1707 return 0; 1708 return 1; 1709 } 1710 1711 static int 1712 session_env_req(struct ssh *ssh, Session *s) 1713 { 1714 char *name, *val; 1715 u_int name_len, val_len, i; 1716 1717 name = packet_get_cstring(&name_len); 1718 val = packet_get_cstring(&val_len); 1719 packet_check_eom(); 1720 1721 /* Don't set too many environment variables */ 1722 if (s->num_env > 128) { 1723 debug2("Ignoring env request %s: too many env vars", name); 1724 goto fail; 1725 } 1726 1727 for (i = 0; i < options.num_accept_env; i++) { 1728 if (match_pattern(name, options.accept_env[i])) { 1729 debug2("Setting env %d: %s=%s", s->num_env, name, val); 1730 s->env = xrecallocarray(s->env, s->num_env, 1731 s->num_env + 1, sizeof(*s->env)); 1732 s->env[s->num_env].name = name; 1733 s->env[s->num_env].val = val; 1734 s->num_env++; 1735 return (1); 1736 } 1737 } 1738 debug2("Ignoring env request %s: disallowed name", name); 1739 1740 fail: 1741 free(name); 1742 free(val); 1743 return (0); 1744 } 1745 1746 static int 1747 session_auth_agent_req(struct ssh *ssh, Session *s) 1748 { 1749 static int called = 0; 1750 1751 packet_check_eom(); 1752 if (!auth_opts->permit_agent_forwarding_flag || 1753 !options.allow_agent_forwarding) { 1754 debug("%s: agent forwarding disabled", __func__); 1755 return 0; 1756 } 1757 if (called) { 1758 return 0; 1759 } else { 1760 called = 1; 1761 return auth_input_request_forwarding(ssh, s->pw); 1762 } 1763 } 1764 1765 int 1766 session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype) 1767 { 1768 int success = 0; 1769 Session *s; 1770 1771 if ((s = session_by_channel(c->self)) == NULL) { 1772 logit("%s: no session %d req %.100s", __func__, c->self, rtype); 1773 return 0; 1774 } 1775 debug("%s: session %d req %s", __func__, s->self, rtype); 1776 1777 /* 1778 * a session is in LARVAL state until a shell, a command 1779 * or a subsystem is executed 1780 */ 1781 if (c->type == SSH_CHANNEL_LARVAL) { 1782 if (strcmp(rtype, "shell") == 0) { 1783 success = session_shell_req(ssh, s); 1784 } else if (strcmp(rtype, "exec") == 0) { 1785 success = session_exec_req(ssh, s); 1786 } else if (strcmp(rtype, "pty-req") == 0) { 1787 success = session_pty_req(ssh, s); 1788 } else if (strcmp(rtype, "x11-req") == 0) { 1789 success = session_x11_req(ssh, s); 1790 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { 1791 success = session_auth_agent_req(ssh, s); 1792 } else if (strcmp(rtype, "subsystem") == 0) { 1793 success = session_subsystem_req(ssh, s); 1794 } else if (strcmp(rtype, "env") == 0) { 1795 success = session_env_req(ssh, s); 1796 } 1797 } 1798 if (strcmp(rtype, "window-change") == 0) { 1799 success = session_window_change_req(ssh, s); 1800 } else if (strcmp(rtype, "break") == 0) { 1801 success = session_break_req(ssh, s); 1802 } 1803 1804 return success; 1805 } 1806 1807 void 1808 session_set_fds(struct ssh *ssh, Session *s, 1809 int fdin, int fdout, int fderr, int ignore_fderr, int is_tty) 1810 { 1811 /* 1812 * now that have a child and a pipe to the child, 1813 * we can activate our channel and register the fd's 1814 */ 1815 if (s->chanid == -1) 1816 fatal("no channel for session %d", s->self); 1817 channel_set_fds(ssh, s->chanid, 1818 fdout, fdin, fderr, 1819 ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, 1820 1, is_tty, CHAN_SES_WINDOW_DEFAULT); 1821 } 1822 1823 /* 1824 * Function to perform pty cleanup. Also called if we get aborted abnormally 1825 * (e.g., due to a dropped connection). 1826 */ 1827 void 1828 session_pty_cleanup2(Session *s) 1829 { 1830 if (s == NULL) { 1831 error("session_pty_cleanup: no session"); 1832 return; 1833 } 1834 if (s->ttyfd == -1) 1835 return; 1836 1837 debug("session_pty_cleanup: session %d release %s", s->self, s->tty); 1838 1839 /* Record that the user has logged out. */ 1840 if (s->pid != 0) 1841 record_logout(s->pid, s->tty); 1842 1843 /* Release the pseudo-tty. */ 1844 if (getuid() == 0) 1845 pty_release(s->tty); 1846 1847 /* 1848 * Close the server side of the socket pairs. We must do this after 1849 * the pty cleanup, so that another process doesn't get this pty 1850 * while we're still cleaning up. 1851 */ 1852 if (s->ptymaster != -1 && close(s->ptymaster) < 0) 1853 error("close(s->ptymaster/%d): %s", 1854 s->ptymaster, strerror(errno)); 1855 1856 /* unlink pty from session */ 1857 s->ttyfd = -1; 1858 } 1859 1860 void 1861 session_pty_cleanup(Session *s) 1862 { 1863 PRIVSEP(session_pty_cleanup2(s)); 1864 } 1865 1866 static char * 1867 sig2name(int sig) 1868 { 1869 #define SSH_SIG(x) if (sig == SIG ## x) return #x 1870 SSH_SIG(ABRT); 1871 SSH_SIG(ALRM); 1872 SSH_SIG(FPE); 1873 SSH_SIG(HUP); 1874 SSH_SIG(ILL); 1875 SSH_SIG(INT); 1876 SSH_SIG(KILL); 1877 SSH_SIG(PIPE); 1878 SSH_SIG(QUIT); 1879 SSH_SIG(SEGV); 1880 SSH_SIG(TERM); 1881 SSH_SIG(USR1); 1882 SSH_SIG(USR2); 1883 #undef SSH_SIG 1884 return "SIG@openssh.com"; 1885 } 1886 1887 static void 1888 session_close_x11(struct ssh *ssh, int id) 1889 { 1890 Channel *c; 1891 1892 if ((c = channel_by_id(ssh, id)) == NULL) { 1893 debug("%s: x11 channel %d missing", __func__, id); 1894 } else { 1895 /* Detach X11 listener */ 1896 debug("%s: detach x11 channel %d", __func__, id); 1897 channel_cancel_cleanup(ssh, id); 1898 if (c->ostate != CHAN_OUTPUT_CLOSED) 1899 chan_mark_dead(ssh, c); 1900 } 1901 } 1902 1903 static void 1904 session_close_single_x11(struct ssh *ssh, int id, void *arg) 1905 { 1906 Session *s; 1907 u_int i; 1908 1909 debug3("%s: channel %d", __func__, id); 1910 channel_cancel_cleanup(ssh, id); 1911 if ((s = session_by_x11_channel(id)) == NULL) 1912 fatal("%s: no x11 channel %d", __func__, id); 1913 for (i = 0; s->x11_chanids[i] != -1; i++) { 1914 debug("%s: session %d: closing channel %d", 1915 __func__, s->self, s->x11_chanids[i]); 1916 /* 1917 * The channel "id" is already closing, but make sure we 1918 * close all of its siblings. 1919 */ 1920 if (s->x11_chanids[i] != id) 1921 session_close_x11(ssh, s->x11_chanids[i]); 1922 } 1923 free(s->x11_chanids); 1924 s->x11_chanids = NULL; 1925 free(s->display); 1926 s->display = NULL; 1927 free(s->auth_proto); 1928 s->auth_proto = NULL; 1929 free(s->auth_data); 1930 s->auth_data = NULL; 1931 free(s->auth_display); 1932 s->auth_display = NULL; 1933 } 1934 1935 static void 1936 session_exit_message(struct ssh *ssh, Session *s, int status) 1937 { 1938 Channel *c; 1939 1940 if ((c = channel_lookup(ssh, s->chanid)) == NULL) 1941 fatal("%s: session %d: no channel %d", 1942 __func__, s->self, s->chanid); 1943 debug("%s: session %d channel %d pid %ld", 1944 __func__, s->self, s->chanid, (long)s->pid); 1945 1946 if (WIFEXITED(status)) { 1947 channel_request_start(ssh, s->chanid, "exit-status", 0); 1948 packet_put_int(WEXITSTATUS(status)); 1949 packet_send(); 1950 } else if (WIFSIGNALED(status)) { 1951 channel_request_start(ssh, s->chanid, "exit-signal", 0); 1952 packet_put_cstring(sig2name(WTERMSIG(status))); 1953 packet_put_char(WCOREDUMP(status)? 1 : 0); 1954 packet_put_cstring(""); 1955 packet_put_cstring(""); 1956 packet_send(); 1957 } else { 1958 /* Some weird exit cause. Just exit. */ 1959 packet_disconnect("wait returned status %04x.", status); 1960 } 1961 1962 /* disconnect channel */ 1963 debug("%s: release channel %d", __func__, s->chanid); 1964 1965 /* 1966 * Adjust cleanup callback attachment to send close messages when 1967 * the channel gets EOF. The session will be then be closed 1968 * by session_close_by_channel when the childs close their fds. 1969 */ 1970 channel_register_cleanup(ssh, c->self, session_close_by_channel, 1); 1971 1972 /* 1973 * emulate a write failure with 'chan_write_failed', nobody will be 1974 * interested in data we write. 1975 * Note that we must not call 'chan_read_failed', since there could 1976 * be some more data waiting in the pipe. 1977 */ 1978 if (c->ostate != CHAN_OUTPUT_CLOSED) 1979 chan_write_failed(ssh, c); 1980 } 1981 1982 void 1983 session_close(struct ssh *ssh, Session *s) 1984 { 1985 u_int i; 1986 1987 verbose("Close session: user %s from %.200s port %d id %d", 1988 s->pw->pw_name, 1989 ssh_remote_ipaddr(ssh), 1990 ssh_remote_port(ssh), 1991 s->self); 1992 1993 if (s->ttyfd != -1) 1994 session_pty_cleanup(s); 1995 free(s->term); 1996 free(s->display); 1997 free(s->x11_chanids); 1998 free(s->auth_display); 1999 free(s->auth_data); 2000 free(s->auth_proto); 2001 free(s->subsys); 2002 if (s->env != NULL) { 2003 for (i = 0; i < s->num_env; i++) { 2004 free(s->env[i].name); 2005 free(s->env[i].val); 2006 } 2007 free(s->env); 2008 } 2009 session_proctitle(s); 2010 session_unused(s->self); 2011 } 2012 2013 void 2014 session_close_by_pid(struct ssh *ssh, pid_t pid, int status) 2015 { 2016 Session *s = session_by_pid(pid); 2017 if (s == NULL) { 2018 debug("%s: no session for pid %ld", __func__, (long)pid); 2019 return; 2020 } 2021 if (s->chanid != -1) 2022 session_exit_message(ssh, s, status); 2023 if (s->ttyfd != -1) 2024 session_pty_cleanup(s); 2025 s->pid = 0; 2026 } 2027 2028 /* 2029 * this is called when a channel dies before 2030 * the session 'child' itself dies 2031 */ 2032 void 2033 session_close_by_channel(struct ssh *ssh, int id, void *arg) 2034 { 2035 Session *s = session_by_channel(id); 2036 u_int i; 2037 2038 if (s == NULL) { 2039 debug("%s: no session for id %d", __func__, id); 2040 return; 2041 } 2042 debug("%s: channel %d child %ld", __func__, id, (long)s->pid); 2043 if (s->pid != 0) { 2044 debug("%s: channel %d: has child", __func__, id); 2045 /* 2046 * delay detach of session, but release pty, since 2047 * the fd's to the child are already closed 2048 */ 2049 if (s->ttyfd != -1) 2050 session_pty_cleanup(s); 2051 return; 2052 } 2053 /* detach by removing callback */ 2054 channel_cancel_cleanup(ssh, s->chanid); 2055 2056 /* Close any X11 listeners associated with this session */ 2057 if (s->x11_chanids != NULL) { 2058 for (i = 0; s->x11_chanids[i] != -1; i++) { 2059 session_close_x11(ssh, s->x11_chanids[i]); 2060 s->x11_chanids[i] = -1; 2061 } 2062 } 2063 2064 s->chanid = -1; 2065 session_close(ssh, s); 2066 } 2067 2068 void 2069 session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *)) 2070 { 2071 int i; 2072 for (i = 0; i < sessions_nalloc; i++) { 2073 Session *s = &sessions[i]; 2074 if (s->used) { 2075 if (closefunc != NULL) 2076 closefunc(s); 2077 else 2078 session_close(ssh, s); 2079 } 2080 } 2081 } 2082 2083 static char * 2084 session_tty_list(void) 2085 { 2086 static char buf[1024]; 2087 int i; 2088 buf[0] = '\0'; 2089 for (i = 0; i < sessions_nalloc; i++) { 2090 Session *s = &sessions[i]; 2091 if (s->used && s->ttyfd != -1) { 2092 if (buf[0] != '\0') 2093 strlcat(buf, ",", sizeof buf); 2094 strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf); 2095 } 2096 } 2097 if (buf[0] == '\0') 2098 strlcpy(buf, "notty", sizeof buf); 2099 return buf; 2100 } 2101 2102 void 2103 session_proctitle(Session *s) 2104 { 2105 if (s->pw == NULL) 2106 error("no user for session %d", s->self); 2107 else 2108 setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); 2109 } 2110 2111 int 2112 session_setup_x11fwd(struct ssh *ssh, Session *s) 2113 { 2114 struct stat st; 2115 char display[512], auth_display[512]; 2116 char hostname[NI_MAXHOST]; 2117 u_int i; 2118 2119 if (!auth_opts->permit_x11_forwarding_flag) { 2120 packet_send_debug("X11 forwarding disabled by key options."); 2121 return 0; 2122 } 2123 if (!options.x11_forwarding) { 2124 debug("X11 forwarding disabled in server configuration file."); 2125 return 0; 2126 } 2127 if (options.xauth_location == NULL || 2128 (stat(options.xauth_location, &st) == -1)) { 2129 packet_send_debug("No xauth program; cannot forward X11."); 2130 return 0; 2131 } 2132 if (s->display != NULL) { 2133 debug("X11 display already set."); 2134 return 0; 2135 } 2136 if (x11_create_display_inet(ssh, options.x11_display_offset, 2137 options.x11_use_localhost, s->single_connection, 2138 &s->display_number, &s->x11_chanids) == -1) { 2139 debug("x11_create_display_inet failed."); 2140 return 0; 2141 } 2142 for (i = 0; s->x11_chanids[i] != -1; i++) { 2143 channel_register_cleanup(ssh, s->x11_chanids[i], 2144 session_close_single_x11, 0); 2145 } 2146 2147 /* Set up a suitable value for the DISPLAY variable. */ 2148 if (gethostname(hostname, sizeof(hostname)) < 0) 2149 fatal("gethostname: %.100s", strerror(errno)); 2150 /* 2151 * auth_display must be used as the displayname when the 2152 * authorization entry is added with xauth(1). This will be 2153 * different than the DISPLAY string for localhost displays. 2154 */ 2155 if (options.x11_use_localhost) { 2156 snprintf(display, sizeof display, "localhost:%u.%u", 2157 s->display_number, s->screen); 2158 snprintf(auth_display, sizeof auth_display, "unix:%u.%u", 2159 s->display_number, s->screen); 2160 s->display = xstrdup(display); 2161 s->auth_display = xstrdup(auth_display); 2162 } else { 2163 snprintf(display, sizeof display, "%.400s:%u.%u", hostname, 2164 s->display_number, s->screen); 2165 s->display = xstrdup(display); 2166 s->auth_display = xstrdup(display); 2167 } 2168 2169 return 1; 2170 } 2171 2172 static void 2173 do_authenticated2(struct ssh *ssh, Authctxt *authctxt) 2174 { 2175 server_loop2(ssh, authctxt); 2176 } 2177 2178 void 2179 do_cleanup(struct ssh *ssh, Authctxt *authctxt) 2180 { 2181 static int called = 0; 2182 2183 debug("do_cleanup"); 2184 2185 /* no cleanup if we're in the child for login shell */ 2186 if (is_child) 2187 return; 2188 2189 /* avoid double cleanup */ 2190 if (called) 2191 return; 2192 called = 1; 2193 2194 if (authctxt == NULL || !authctxt->authenticated) 2195 return; 2196 #ifdef KRB5 2197 if (options.kerberos_ticket_cleanup && 2198 authctxt->krb5_ctx) 2199 krb5_cleanup_proc(authctxt); 2200 #endif 2201 2202 #ifdef GSSAPI 2203 if (options.gss_cleanup_creds) 2204 ssh_gssapi_cleanup_creds(); 2205 #endif 2206 2207 /* remove agent socket */ 2208 auth_sock_cleanup_proc(authctxt->pw); 2209 2210 /* remove userauth info */ 2211 if (auth_info_file != NULL) { 2212 temporarily_use_uid(authctxt->pw); 2213 unlink(auth_info_file); 2214 restore_uid(); 2215 free(auth_info_file); 2216 auth_info_file = NULL; 2217 } 2218 2219 /* 2220 * Cleanup ptys/utmp only if privsep is disabled, 2221 * or if running in monitor. 2222 */ 2223 if (!use_privsep || mm_is_monitor()) 2224 session_destroy_all(ssh, session_pty_cleanup2); 2225 } 2226 2227 /* Return a name for the remote host that fits inside utmp_size */ 2228 2229 const char * 2230 session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns) 2231 { 2232 const char *remote = ""; 2233 2234 if (utmp_size > 0) 2235 remote = auth_get_canonical_hostname(ssh, use_dns); 2236 if (utmp_size == 0 || strlen(remote) > utmp_size) 2237 remote = ssh_remote_ipaddr(ssh); 2238 return remote; 2239 } 2240 2241