session.c

   1 /*
   2  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   3  *                    All rights reserved
   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  *
  11  * SSH2 support by Markus Friedl.
  12  * Copyright (c) 2000 Markus Friedl. All rights reserved.
  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.
  33  */
  34
  35 #include "includes.h"
  36 RCSID("$OpenBSD: session.c,v 1.52 2001/02/03 10:08:37 markus Exp $");
  37
  38 #include "ssh.h"
  39 #include "ssh1.h"
  40 #include "ssh2.h"
  41 #include "xmalloc.h"
  42 #include "pty.h"
  43 #include "packet.h"
  44 #include "buffer.h"
  45 #include "mpaux.h"
  46 #include "uidswap.h"
  47 #include "compat.h"
  48 #include "channels.h"
  49 #include "nchan.h"
  50 #include "bufaux.h"
  51 #include "auth.h"
  52 #include "auth-options.h"
  53 #include "pathnames.h"
  54 #include "log.h"
  55 #include "servconf.h"
  56 #include "login.h"
  57 #include "serverloop.h"
  58 #include "canohost.h"
  59
  60 #ifdef WITH_IRIX_PROJECT
  61 #include <proj.h>
  62 #endif /* WITH_IRIX_PROJECT */
  63 #ifdef WITH_IRIX_JOBS
  64 #include <sys/resource.h>
  65 #endif
  66 #ifdef WITH_IRIX_AUDIT
  67 #include <sat.h>
  68 #endif /* WITH_IRIX_AUDIT */
  69
  70 #if defined(HAVE_USERSEC_H)
  71 #include <usersec.h>
  72 #endif
  73
  74 #ifdef HAVE_OSF_SIA
  75 # include <sia.h>
  76 # include <siad.h>
  77 #endif
  78
  79 #ifdef HAVE_CYGWIN
  80 #include <windows.h>
  81 #include <sys/cygwin.h>
  82 #define is_winnt       (GetVersion() < 0x80000000)
  83 #endif
  84
  85 /* AIX limits */
  86 #if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE)
  87 # define S_UFSIZE_HARD  S_UFSIZE "_hard"
  88 # define S_UCPU_HARD  S_UCPU "_hard"
  89 # define S_UDATA_HARD  S_UDATA "_hard"
  90 # define S_USTACK_HARD  S_USTACK "_hard"
  91 # define S_URSS_HARD  S_URSS "_hard"
  92 # define S_UCORE_HARD  S_UCORE "_hard"
  93 # define S_UNOFILE_HARD S_UNOFILE "_hard"
  94 #endif
  95
  96 #ifdef HAVE_LOGIN_CAP
  97 #include <login_cap.h>
  98 #endif
  99
 100 /* types */
 101
 102 #define TTYSZ 64
 103 typedef struct Session Session;
 104 struct Session {
 105         int     used;
 106         int     self;
 107         int     extended;
 108         struct  passwd *pw;
 109         pid_t   pid;
 110         /* tty */
 111         char    *term;
 112         int     ptyfd, ttyfd, ptymaster;
 113         int     row, col, xpixel, ypixel;
 114         char    tty[TTYSZ];
 115         /* X11 */
 116         char    *display;
 117         int     screen;
 118         char    *auth_proto;
 119         char    *auth_data;
 120         int     single_connection;
 121         /* proto 2 */
 122         int     chanid;
 123 };
 124
 125 /* func */
 126
 127 Session *session_new(void);
 128 void    session_set_fds(Session *s, int fdin, int fdout, int fderr);
 129 void    session_pty_cleanup(Session *s);
 130 void    session_proctitle(Session *s);
 131 void    do_exec_pty(Session *s, const char *command, struct passwd * pw);
 132 void    do_exec_no_pty(Session *s, const char *command, struct passwd * pw);
 133 void    do_login(Session *s, const char *command);
 134
 135 void
 136 do_child(const char *command, struct passwd * pw, const char *term,
 137     const char *display, const char *auth_proto,
 138     const char *auth_data, const char *ttyname);
 139
 140 /* import */
 141 extern ServerOptions options;
 142 extern char *__progname;
 143 extern int log_stderr;
 144 extern int debug_flag;
 145 extern u_int utmp_len;
 146
 147 extern int startup_pipe;
 148
 149 /* Local Xauthority file. */
 150 static char *xauthfile;
 151
 152 /* original command from peer. */
 153 char *original_command = NULL;
 154
 155 /* data */
 156 #define MAX_SESSIONS 10
 157 Session sessions[MAX_SESSIONS];
 158
 159 #ifdef WITH_AIXAUTHENTICATE
 160 /* AIX's lastlogin message, set in auth1.c */
 161 char *aixloginmsg;
 162 #endif /* WITH_AIXAUTHENTICATE */
 163
 164 #ifdef HAVE_LOGIN_CAP
 165 static login_cap_t *lc;
 166 #endif
 167
 168 /*
 169  * Remove local Xauthority file.
 170  */
 171 void
 172 xauthfile_cleanup_proc(void *ignore)
 173 {
 174         debug("xauthfile_cleanup_proc called");
 175
 176         if (xauthfile != NULL) {
 177                 char *p;
 178                 unlink(xauthfile);
 179                 p = strrchr(xauthfile, '/');
 180                 if (p != NULL) {
 181                         *p = '\0';
 182                         rmdir(xauthfile);
 183                 }
 184                 xfree(xauthfile);
 185                 xauthfile = NULL;
 186         }
 187 }
 188
 189 /*
 190  * Function to perform cleanup if we get aborted abnormally (e.g., due to a
 191  * dropped connection).
 192  */
 193 void
 194 pty_cleanup_proc(void *session)
 195 {
 196         Session *s=session;
 197         if (s == NULL)
 198                 fatal("pty_cleanup_proc: no session");
 199         debug("pty_cleanup_proc: %s", s->tty);
 200
 201         if (s->pid != 0) {
 202                 /* Record that the user has logged out. */
 203                 record_logout(s->pid, s->tty);
 204         }
 205
 206         /* Release the pseudo-tty. */
 207         pty_release(s->tty);
 208 }
 209
 210 /*
 211  * Prepares for an interactive session.  This is called after the user has
 212  * been successfully authenticated.  During this message exchange, pseudo
 213  * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
 214  * are requested, etc.
 215  */
 216 void
 217 do_authenticated(struct passwd * pw)
 218 {
 219         Session *s;
 220         int type, fd;
 221         int compression_level = 0, enable_compression_after_reply = 0;
 222         int have_pty = 0;
 223         char *command;
 224         int n_bytes;
 225         int plen;
 226         u_int proto_len, data_len, dlen;
 227
 228         /*
 229          * Cancel the alarm we set to limit the time taken for
 230          * authentication.
 231          */
 232         alarm(0);
 233         if (startup_pipe != -1) {
 234                 close(startup_pipe);
 235                 startup_pipe = -1;
 236         }
 237
 238         /*
 239          * Inform the channel mechanism that we are the server side and that
 240          * the client may request to connect to any port at all. (The user
 241          * could do it anyway, and we wouldn\'t know what is permitted except
 242          * by the client telling us, so we can equally well trust the client
 243          * not to request anything bogus.)
 244          */
 245         if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
 246                 channel_permit_all_opens();
 247
 248         s = session_new();
 249         s->pw = pw;
 250
 251 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
 252         if ((lc = login_getclass(pw->pw_class)) == NULL) {
 253                 error("unable to get login class");
 254                 return;
 255         }
 256 #endif
 257
 258         /*
 259          * We stay in this loop until the client requests to execute a shell
 260          * or a command.
 261          */
 262         for (;;) {
 263                 int success = 0;
 264
 265                 /* Get a packet from the client. */
 266                 type = packet_read(&plen);
 267
 268                 /* Process the packet. */
 269                 switch (type) {
 270                 case SSH_CMSG_REQUEST_COMPRESSION:
 271                         packet_integrity_check(plen, 4, type);
 272                         compression_level = packet_get_int();
 273                         if (compression_level < 1 || compression_level > 9) {
 274                                 packet_send_debug("Received illegal compression level %d.",
 275                                      compression_level);
 276                                 break;
 277                         }
 278                         /* Enable compression after we have responded with SUCCESS. */
 279                         enable_compression_after_reply = 1;
 280                         success = 1;
 281                         break;
 282
 283                 case SSH_CMSG_REQUEST_PTY:
 284                         if (no_pty_flag) {
 285                                 debug("Allocating a pty not permitted for this authentication.");
 286                                 break;
 287                         }
 288                         if (have_pty)
 289                                 packet_disconnect("Protocol error: you already have a pty.");
 290
 291                         debug("Allocating pty.");
 292
 293                         /* Allocate a pty and open it. */
 294                         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
 295                             sizeof(s->tty))) {
 296                                 error("Failed to allocate pty.");
 297                                 break;
 298                         }
 299                         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
 300                         pty_setowner(pw, s->tty);
 301
 302                         /* Get TERM from the packet.  Note that the value may be of arbitrary length. */
 303                         s->term = packet_get_string(&dlen);
 304                         packet_integrity_check(dlen, strlen(s->term), type);
 305                         /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
 306                         /* Remaining bytes */
 307                         n_bytes = plen - (4 + dlen + 4 * 4);
 308
 309                         if (strcmp(s->term, "") == 0) {
 310                                 xfree(s->term);
 311                                 s->term = NULL;
 312                         }
 313                         /* Get window size from the packet. */
 314                         s->row = packet_get_int();
 315                         s->col = packet_get_int();
 316                         s->xpixel = packet_get_int();
 317                         s->ypixel = packet_get_int();
 318                         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
 319
 320                         /* Get tty modes from the packet. */
 321                         tty_parse_modes(s->ttyfd, &n_bytes);
 322                         packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
 323
 324                         session_proctitle(s);
 325
 326                         /* Indicate that we now have a pty. */
 327                         success = 1;
 328                         have_pty = 1;
 329                         break;
 330
 331                 case SSH_CMSG_X11_REQUEST_FORWARDING:
 332                         if (!options.x11_forwarding) {
 333                                 packet_send_debug("X11 forwarding disabled in server configuration file.");
 334                                 break;
 335                         }
 336                         if (!options.xauth_location) {
 337                                 packet_send_debug("No xauth program; cannot forward with spoofing.");
 338                                 break;
 339                         }
 340                         if (no_x11_forwarding_flag) {
 341                                 packet_send_debug("X11 forwarding not permitted for this authentication.");
 342                                 break;
 343                         }
 344                         debug("Received request for X11 forwarding with auth spoofing.");
 345                         if (s->display != NULL)
 346                                 packet_disconnect("Protocol error: X11 display already set.");
 347
 348                         s->auth_proto = packet_get_string(&proto_len);
 349                         s->auth_data = packet_get_string(&data_len);
 350                         packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type);
 351
 352                         if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER)
 353                                 s->screen = packet_get_int();
 354                         else
 355                                 s->screen = 0;
 356                         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
 357
 358                         if (s->display == NULL)
 359                                 break;
 360
 361                         /* Setup to always have a local .Xauthority. */
 362                         xauthfile = xmalloc(MAXPATHLEN);
 363                         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
 364                         temporarily_use_uid(pw->pw_uid);
 365                         if (mkdtemp(xauthfile) == NULL) {
 366                                 restore_uid();
 367                                 error("private X11 dir: mkdtemp %s failed: %s",
 368                                     xauthfile, strerror(errno));
 369                                 xfree(xauthfile);
 370                                 xauthfile = NULL;
 371                                 /* XXXX remove listening channels */
 372                                 break;
 373                         }
 374                         strlcat(xauthfile, "/cookies", MAXPATHLEN);
 375                         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
 376                         if (fd >= 0)
 377                                 close(fd);
 378                         restore_uid();
 379                         fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
 380                         success = 1;
 381                         break;
 382
 383                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
 384                         if (no_agent_forwarding_flag || compat13) {
 385                                 debug("Authentication agent forwarding not permitted for this authentication.");
 386                                 break;
 387                         }
 388                         debug("Received authentication agent forwarding request.");
 389                         success = auth_input_request_forwarding(pw);
 390                         break;
 391
 392                 case SSH_CMSG_PORT_FORWARD_REQUEST:
 393                         if (no_port_forwarding_flag) {
 394                                 debug("Port forwarding not permitted for this authentication.");
 395                                 break;
 396                         }
 397                         if (!options.allow_tcp_forwarding) {
 398                                 debug("Port forwarding not permitted.");
 399                                 break;
 400                         }
 401                         debug("Received TCP/IP port forwarding request.");
 402                         channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports);
 403                         success = 1;
 404                         break;
 405
 406                 case SSH_CMSG_MAX_PACKET_SIZE:
 407                         if (packet_set_maxsize(packet_get_int()) > 0)
 408                                 success = 1;
 409                         break;
 410
 411                 case SSH_CMSG_EXEC_SHELL:
 412                 case SSH_CMSG_EXEC_CMD:
 413                         if (type == SSH_CMSG_EXEC_CMD) {
 414                                 command = packet_get_string(&dlen);
 415                                 debug("Exec command '%.500s'", command);
 416                                 packet_integrity_check(plen, 4 + dlen, type);
 417                         } else {
 418                                 command = NULL;
 419                                 packet_integrity_check(plen, 0, type);
 420                         }
 421                         if (forced_command != NULL) {
 422                                 original_command = command;
 423                                 command = forced_command;
 424                                 debug("Forced command '%.500s'", forced_command);
 425                         }
 426                         if (have_pty)
 427                                 do_exec_pty(s, command, pw);
 428                         else
 429                                 do_exec_no_pty(s, command, pw);
 430
 431                         if (command != NULL)
 432                                 xfree(command);
 433                         /* Cleanup user's local Xauthority file. */
 434                         if (xauthfile)
 435                                 xauthfile_cleanup_proc(NULL);
 436                         return;
 437
 438                 default:
 439                         /*
 440                          * Any unknown messages in this phase are ignored,
 441                          * and a failure message is returned.
 442                          */
 443                         log("Unknown packet type received after authentication: %d", type);
 444                 }
 445                 packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
 446                 packet_send();
 447                 packet_write_wait();
 448
 449                 /* Enable compression now that we have replied if appropriate. */
 450                 if (enable_compression_after_reply) {
 451                         enable_compression_after_reply = 0;
 452                         packet_start_compression(compression_level);
 453                 }
 454         }
 455 }
 456
 457 /*
 458  * This is called to fork and execute a command when we have no tty.  This
 459  * will call do_child from the child, and server_loop from the parent after
 460  * setting up file descriptors and such.
 461  */
 462 void
 463 do_exec_no_pty(Session *s, const char *command, struct passwd * pw)
 464 {
 465         int pid;
 466
 467 #ifdef USE_PIPES
 468         int pin[2], pout[2], perr[2];
 469         /* Allocate pipes for communicating with the program. */
 470         if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
 471                 packet_disconnect("Could not create pipes: %.100s",
 472                                   strerror(errno));
 473 #else /* USE_PIPES */
 474         int inout[2], err[2];
 475         /* Uses socket pairs to communicate with the program. */
 476         if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
 477             socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
 478                 packet_disconnect("Could not create socket pairs: %.100s",
 479                                   strerror(errno));
 480 #endif /* USE_PIPES */
 481         if (s == NULL)
 482                 fatal("do_exec_no_pty: no session");
 483
 484         session_proctitle(s);
 485
 486 #ifdef USE_PAM
 487                         do_pam_setcred();
 488 #endif /* USE_PAM */
 489
 490         /* Fork the child. */
 491         if ((pid = fork()) == 0) {
 492                 /* Child.  Reinitialize the log since the pid has changed. */
 493                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 494
 495                 signal(SIGPIPE, SIG_DFL);
 496
 497                 /*
 498                  * Create a new session and process group since the 4.4BSD
 499                  * setlogin() affects the entire process group.
 500                  */
 501                 if (setsid() < 0)
 502                         error("setsid failed: %.100s", strerror(errno));
 503
 504 #ifdef USE_PIPES
 505                 /*
 506                  * Redirect stdin.  We close the parent side of the socket
 507                  * pair, and make the child side the standard input.
 508                  */
 509                 close(pin[1]);
 510                 if (dup2(pin[0], 0) < 0)
 511                         perror("dup2 stdin");
 512                 close(pin[0]);
 513
 514                 /* Redirect stdout. */
 515                 close(pout[0]);
 516                 if (dup2(pout[1], 1) < 0)
 517                         perror("dup2 stdout");
 518                 close(pout[1]);
 519
 520                 /* Redirect stderr. */
 521                 close(perr[0]);
 522                 if (dup2(perr[1], 2) < 0)
 523                         perror("dup2 stderr");
 524                 close(perr[1]);
 525 #else /* USE_PIPES */
 526                 /*
 527                  * Redirect stdin, stdout, and stderr.  Stdin and stdout will
 528                  * use the same socket, as some programs (particularly rdist)
 529                  * seem to depend on it.
 530                  */
 531                 close(inout[1]);
 532                 close(err[1]);
 533                 if (dup2(inout[0], 0) < 0)      /* stdin */
 534                         perror("dup2 stdin");
 535                 if (dup2(inout[0], 1) < 0)      /* stdout.  Note: same socket as stdin. */
 536                         perror("dup2 stdout");
 537                 if (dup2(err[0], 2) < 0)        /* stderr */
 538                         perror("dup2 stderr");
 539 #endif /* USE_PIPES */
 540
 541                 /* Do processing for the child (exec command etc). */
 542                 do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL);
 543                 /* NOTREACHED */
 544         }
 545 #ifdef HAVE_CYGWIN
 546         if (is_winnt)
 547                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 548 #endif
 549         if (pid < 0)
 550                 packet_disconnect("fork failed: %.100s", strerror(errno));
 551         s->pid = pid;
 552         /* Set interactive/non-interactive mode. */
 553         packet_set_interactive(s->display != NULL);
 554 #ifdef USE_PIPES
 555         /* We are the parent.  Close the child sides of the pipes. */
 556         close(pin[0]);
 557         close(pout[1]);
 558         close(perr[1]);
 559
 560         if (compat20) {
 561                 session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1);
 562         } else {
 563                 /* Enter the interactive session. */
 564                 server_loop(pid, pin[1], pout[0], perr[0]);
 565                 /* server_loop has closed pin[1], pout[1], and perr[1]. */
 566         }
 567 #else /* USE_PIPES */
 568         /* We are the parent.  Close the child sides of the socket pairs. */
 569         close(inout[0]);
 570         close(err[0]);
 571
 572         /*
 573          * Enter the interactive session.  Note: server_loop must be able to
 574          * handle the case that fdin and fdout are the same.
 575          */
 576         if (compat20) {
 577                 session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1);
 578         } else {
 579                 server_loop(pid, inout[1], inout[1], err[1]);
 580                 /* server_loop has closed inout[1] and err[1]. */
 581         }
 582 #endif /* USE_PIPES */
 583 }
 584
 585 /*
 586  * This is called to fork and execute a command when we have a tty.  This
 587  * will call do_child from the child, and server_loop from the parent after
 588  * setting up file descriptors, controlling tty, updating wtmp, utmp,
 589  * lastlog, and other such operations.
 590  */
 591 void
 592 do_exec_pty(Session *s, const char *command, struct passwd * pw)
 593 {
 594         int fdout, ptyfd, ttyfd, ptymaster;
 595         pid_t pid;
 596
 597         if (s == NULL)
 598                 fatal("do_exec_pty: no session");
 599         ptyfd = s->ptyfd;
 600         ttyfd = s->ttyfd;
 601
 602 #ifdef USE_PAM
 603                         do_pam_session(pw->pw_name, s->tty);
 604                         do_pam_setcred();
 605 #endif /* USE_PAM */
 606
 607         /* Fork the child. */
 608         if ((pid = fork()) == 0) {
 609                 /* Child.  Reinitialize the log because the pid has changed. */
 610                 log_init(__progname, options.log_level, options.log_facility, log_stderr);
 611
 612                 signal(SIGPIPE, SIG_DFL);
 613
 614                 /* Close the master side of the pseudo tty. */
 615                 close(ptyfd);
 616
 617                 /* Make the pseudo tty our controlling tty. */
 618                 pty_make_controlling_tty(&ttyfd, s->tty);
 619
 620                 /* Redirect stdin from the pseudo tty. */
 621                 if (dup2(ttyfd, fileno(stdin)) < 0)
 622                         error("dup2 stdin failed: %.100s", strerror(errno));
 623
 624                 /* Redirect stdout to the pseudo tty. */
 625                 if (dup2(ttyfd, fileno(stdout)) < 0)
 626                         error("dup2 stdin failed: %.100s", strerror(errno));
 627
 628                 /* Redirect stderr to the pseudo tty. */
 629                 if (dup2(ttyfd, fileno(stderr)) < 0)
 630                         error("dup2 stdin failed: %.100s", strerror(errno));
 631
 632                 /* Close the extra descriptor for the pseudo tty. */
 633                 close(ttyfd);
 634
 635                 /* record login, etc. similar to login(1) */
 636                 if (!(options.use_login && command == NULL))
 637                         do_login(s, command);
 638
 639                 /* Do common processing for the child, such as execing the command. */
 640                 do_child(command, pw, s->term, s->display, s->auth_proto,
 641                     s->auth_data, s->tty);
 642                 /* NOTREACHED */
 643         }
 644 #ifdef HAVE_CYGWIN
 645         if (is_winnt)
 646                 cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
 647 #endif
 648         if (pid < 0)
 649                 packet_disconnect("fork failed: %.100s", strerror(errno));
 650         s->pid = pid;
 651
 652         /* Parent.  Close the slave side of the pseudo tty. */
 653         close(ttyfd);
 654
 655         /*
 656          * Create another descriptor of the pty master side for use as the
 657          * standard input.  We could use the original descriptor, but this
 658          * simplifies code in server_loop.  The descriptor is bidirectional.
 659          */
 660         fdout = dup(ptyfd);
 661         if (fdout < 0)
 662                 packet_disconnect("dup #1 failed: %.100s", strerror(errno));
 663
 664         /* we keep a reference to the pty master */
 665         ptymaster = dup(ptyfd);
 666         if (ptymaster < 0)
 667                 packet_disconnect("dup #2 failed: %.100s", strerror(errno));
 668         s->ptymaster = ptymaster;
 669
 670         /* Enter interactive session. */
 671         packet_set_interactive(1);
 672         if (compat20) {
 673                 session_set_fds(s, ptyfd, fdout, -1);
 674         } else {
 675                 server_loop(pid, ptyfd, fdout, -1);
 676                 /* server_loop _has_ closed ptyfd and fdout. */
 677                 session_pty_cleanup(s);
 678         }
 679 }
 680
 681 const char *
 682 get_remote_name_or_ip(void)
 683 {
 684         static const char *remote = "";
 685         if (utmp_len > 0)
 686                 remote = get_canonical_hostname(options.reverse_mapping_check);
 687         if (utmp_len == 0 || strlen(remote) > utmp_len)
 688                 remote = get_remote_ipaddr();
 689         return remote;
 690 }
 691
 692 /* administrative, login(1)-like work */
 693 void
 694 do_login(Session *s, const char *command)
 695 {
 696         FILE *f;
 697         char *time_string;
 698         char buf[256];
 699         char hostname[MAXHOSTNAMELEN];
 700         socklen_t fromlen;
 701         struct sockaddr_storage from;
 702         struct stat st;
 703         time_t last_login_time;
 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         if (packet_connection_is_on_socket()) {
 713                 fromlen = sizeof(from);
 714                 if (getpeername(packet_get_connection_in(),
 715                      (struct sockaddr *) & from, &fromlen) < 0) {
 716                         debug("getpeername: %.100s", strerror(errno));
 717                         fatal_cleanup();
 718                 }
 719         }
 720
 721         /* Get the time and hostname when the user last logged in. */
 722         hostname[0] = '\0';
 723         last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
 724             hostname, sizeof(hostname));
 725
 726         /* Record that there was a login on that tty from the remote host. */
 727         record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
 728             get_remote_name_or_ip(), (struct sockaddr *)&from);
 729
 730 #ifdef USE_PAM
 731         /*
 732          * If password change is needed, do it now.
 733          * This needs to occur before the ~/.hushlogin check.
 734          */
 735         if (pam_password_change_required()) {
 736                 print_pam_messages();
 737                 do_pam_chauthtok();
 738         }
 739 #endif
 740
 741         /* Done if .hushlogin exists or a command given. */
 742         if (command != NULL)
 743                 return;
 744         snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
 745 #ifdef HAVE_LOGIN_CAP
 746         if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
 747 #else
 748         if (stat(buf, &st) >= 0)
 749 #endif
 750                 return;
 751
 752 #ifdef USE_PAM
 753         if (!pam_password_change_required())
 754                 print_pam_messages();
 755 #endif /* USE_PAM */
 756 #ifdef WITH_AIXAUTHENTICATE
 757         if (aixloginmsg && *aixloginmsg)
 758                 printf("%s\n", aixloginmsg);
 759 #endif /* WITH_AIXAUTHENTICATE */
 760
 761         if (last_login_time != 0) {
 762                 time_string = ctime(&last_login_time);
 763                 if (strchr(time_string, '\n'))
 764                         *strchr(time_string, '\n') = 0;
 765                 if (strcmp(hostname, "") == 0)
 766                         printf("Last login: %s\r\n", time_string);
 767                 else
 768                         printf("Last login: %s from %s\r\n", time_string, hostname);
 769         }
 770         if (options.print_motd) {
 771 #ifdef HAVE_LOGIN_CAP
 772                 f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
 773                     "/etc/motd"), "r");
 774 #else
 775                 f = fopen("/etc/motd", "r");
 776 #endif
 777                 if (f) {
 778                         while (fgets(buf, sizeof(buf), f))
 779                                 fputs(buf, stdout);
 780                         fclose(f);
 781                 }
 782         }
 783 }
 784
 785 /*
 786  * Sets the value of the given variable in the environment.  If the variable
 787  * already exists, its value is overriden.
 788  */
 789 void
 790 child_set_env(char ***envp, u_int *envsizep, const char *name,
 791               const char *value)
 792 {
 793         u_int i, namelen;
 794         char **env;
 795
 796         /*
 797          * Find the slot where the value should be stored.  If the variable
 798          * already exists, we reuse the slot; otherwise we append a new slot
 799          * at the end of the array, expanding if necessary.
 800          */
 801         env = *envp;
 802         namelen = strlen(name);
 803         for (i = 0; env[i]; i++)
 804                 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
 805                         break;
 806         if (env[i]) {
 807                 /* Reuse the slot. */
 808                 xfree(env[i]);
 809         } else {
 810                 /* New variable.  Expand if necessary. */
 811                 if (i >= (*envsizep) - 1) {
 812                         (*envsizep) += 50;
 813                         env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
 814                 }
 815                 /* Need to set the NULL pointer at end of array beyond the new slot. */
 816                 env[i + 1] = NULL;
 817         }
 818
 819         /* Allocate space and format the variable in the appropriate slot. */
 820         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
 821         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 822 }
 823
 824 /*
 825  * Reads environment variables from the given file and adds/overrides them
 826  * into the environment.  If the file does not exist, this does nothing.
 827  * Otherwise, it must consist of empty lines, comments (line starts with '#')
 828  * and assignments of the form name=value.  No other forms are allowed.
 829  */
 830 void
 831 read_environment_file(char ***env, u_int *envsize,
 832                       const char *filename)
 833 {
 834         FILE *f;
 835         char buf[4096];
 836         char *cp, *value;
 837
 838         f = fopen(filename, "r");
 839         if (!f)
 840                 return;
 841
 842         while (fgets(buf, sizeof(buf), f)) {
 843                 for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
 844                         ;
 845                 if (!*cp || *cp == '#' || *cp == '\n')
 846                         continue;
 847                 if (strchr(cp, '\n'))
 848                         *strchr(cp, '\n') = '\0';
 849                 value = strchr(cp, '=');
 850                 if (value == NULL) {
 851                         fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 852                         continue;
 853                 }
 854                 /*
 855                  * Replace the equals sign by nul, and advance value to
 856                  * the value string.
 857                  */
 858                 *value = '\0';
 859                 value++;
 860                 child_set_env(env, envsize, cp, value);
 861         }
 862         fclose(f);
 863 }
 864
 865 #ifdef USE_PAM
 866 /*
 867  * Sets any environment variables which have been specified by PAM
 868  */
 869 void do_pam_environment(char ***env, int *envsize)
 870 {
 871         char *equals, var_name[512], var_val[512];
 872         char **pam_env;
 873         int i;
 874
 875         if ((pam_env = fetch_pam_environment()) == NULL)
 876                 return;
 877
 878         for(i = 0; pam_env[i] != NULL; i++) {
 879                 if ((equals = strstr(pam_env[i], "=")) == NULL)
 880                         continue;
 881
 882                 if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) {
 883                         memset(var_name, '\0', sizeof(var_name));
 884                         memset(var_val, '\0', sizeof(var_val));
 885
 886                         strncpy(var_name, pam_env[i], equals - pam_env[i]);
 887                         strcpy(var_val, equals + 1);
 888
 889                         debug3("PAM environment: %s=%s", var_name, var_val);
 890
 891                         child_set_env(env, envsize, var_name, var_val);
 892                 }
 893         }
 894 }
 895 #endif /* USE_PAM */
 896
 897
 898 #ifdef HAVE_CYGWIN
 899 void copy_environment(char ***env, int *envsize)
 900 {
 901         char *equals, var_name[512], var_val[512];
 902         int i;
 903
 904         for(i = 0; environ[i] != NULL; i++) {
 905                 if ((equals = strstr(environ[i], "=")) == NULL)
 906                         continue;
 907
 908                 if (strlen(environ[i]) < (sizeof(var_name) - 1)) {
 909                         memset(var_name, '\0', sizeof(var_name));
 910                         memset(var_val, '\0', sizeof(var_val));
 911
 912                         strncpy(var_name, environ[i], equals - environ[i]);
 913                         strcpy(var_val, equals + 1);
 914
 915                         debug3("Copy environment: %s=%s", var_name, var_val);
 916
 917                         child_set_env(env, envsize, var_name, var_val);
 918                 }
 919         }
 920 }
 921 #endif
 922
 923 #if defined(HAVE_GETUSERATTR)
 924 /*
 925  * AIX-specific login initialisation
 926  */
 927 void set_limit(char *user, char *soft, char *hard, int resource, int mult)
 928 {
 929         struct rlimit rlim;
 930         int slim, hlim;
 931
 932         getrlimit(resource, &rlim);
 933
 934         slim = 0;
 935         if (getuserattr(user, soft, &slim, SEC_INT) != -1) {
 936                 if (slim < 0) {
 937                         rlim.rlim_cur = RLIM_INFINITY;
 938                 } else if (slim != 0) {
 939                         /* See the wackiness below */
 940                         if (rlim.rlim_cur == slim * mult)
 941                                 slim = 0;
 942                         else
 943                                 rlim.rlim_cur = slim * mult;
 944                 }
 945         }
 946
 947         hlim = 0;
 948         if (getuserattr(user, hard, &hlim, SEC_INT) != -1) {
 949                 if (hlim < 0) {
 950                         rlim.rlim_max = RLIM_INFINITY;
 951                 } else if (hlim != 0) {
 952                         rlim.rlim_max = hlim * mult;
 953                 }
 954         }
 955
 956         /*
 957          * XXX For cpu and fsize the soft limit is set to the hard limit
 958          * if the hard limit is left at its default value and the soft limit
 959          * is changed from its default value, either by requesting it
 960          * (slim == 0) or by setting it to the current default.  At least
 961          * that's how rlogind does it.  If you're confused you're not alone.
 962          * Bug or feature? AIX 4.3.1.2
 963          */
 964         if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu"))
 965             && hlim == 0 && slim != 0)
 966                 rlim.rlim_max = rlim.rlim_cur;
 967         /* A specified hard limit limits the soft limit */
 968         else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max)
 969                 rlim.rlim_cur = rlim.rlim_max;
 970         /* A soft limit can increase a hard limit */
 971         else if (rlim.rlim_cur > rlim.rlim_max)
 972                 rlim.rlim_max = rlim.rlim_cur;
 973
 974         if (setrlimit(resource, &rlim) != 0)
 975                 error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno));
 976 }
 977
 978 void set_limits_from_userattr(char *user)
 979 {
 980         int mask;
 981         char buf[16];
 982
 983         set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512);
 984         set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1);
 985         set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512);
 986         set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512);
 987         set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512);
 988         set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512);
 989 #if defined(S_UNOFILE)
 990         set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1);
 991 #endif
 992
 993         if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) {
 994                 /* Convert decimal to octal */
 995                 (void) snprintf(buf, sizeof(buf), "%d", mask);
 996                 if (sscanf(buf, "%o", &mask) == 1)
 997                         umask(mask);
 998         }
 999 }
1000 #endif /* defined(HAVE_GETUSERATTR) */
1001
1002 /*
1003  * Performs common processing for the child, such as setting up the
1004  * environment, closing extra file descriptors, setting the user and group
1005  * ids, and executing the command or shell.
1006  */
1007 void
1008 do_child(const char *command, struct passwd * pw, const char *term,
1009          const char *display, const char *auth_proto,
1010          const char *auth_data, const char *ttyname)
1011 {
1012         const char *shell, *hostname = NULL, *cp = NULL;
1013         char buf[256];
1014         char cmd[1024];
1015         FILE *f = NULL;
1016         u_int envsize, i;
1017         char **env;
1018         extern char **environ;
1019         struct stat st;
1020         char *argv[10];
1021 #ifdef WITH_IRIX_PROJECT
1022         prid_t projid;
1023 #endif /* WITH_IRIX_PROJECT */
1024 #ifdef WITH_IRIX_JOBS
1025         jid_t jid = 0;
1026 #else
1027 #ifdef WITH_IRIX_ARRAY
1028         int jid = 0;
1029 #endif /* WITH_IRIX_ARRAY */
1030 #endif /* WITH_IRIX_JOBS */
1031
1032
1033         /* login(1) is only called if we execute the login shell */
1034         if (options.use_login && command != NULL)
1035                 options.use_login = 0;
1036
1037 #ifndef USE_PAM /* pam_nologin handles this */
1038         if (!options.use_login) {
1039 # ifdef HAVE_LOGIN_CAP
1040                 if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid)
1041                         f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN,
1042                             _PATH_NOLOGIN), "r");
1043 # else /* HAVE_LOGIN_CAP */
1044                 if (pw->pw_uid)
1045                         f = fopen(_PATH_NOLOGIN, "r");
1046 # endif /* HAVE_LOGIN_CAP */
1047                 if (f) {
1048                         /* /etc/nologin exists.  Print its contents and exit. */
1049                         while (fgets(buf, sizeof(buf), f))
1050                                 fputs(buf, stderr);
1051                         fclose(f);
1052                         exit(254);
1053                 }
1054         }
1055 #endif /* USE_PAM */
1056
1057         /* Set login name, uid, gid, and groups. */
1058         /* Login(1) does this as well, and it needs uid 0 for the "-h"
1059            switch, so we let login(1) to this for us. */
1060         if (!options.use_login) {
1061 #ifdef HAVE_OSF_SIA
1062                 extern char **saved_argv;
1063                 extern int saved_argc;
1064                 char *host = get_canonical_hostname(options.reverse_mapping_check);
1065
1066                 if (sia_become_user(NULL, saved_argc, saved_argv, host,
1067                     pw->pw_name, ttyname, 0, NULL, NULL, SIA_BEU_SETLUID) !=
1068                     SIASUCCESS) {
1069                         perror("sia_become_user");
1070                         exit(1);
1071                 }
1072                 if (setreuid(geteuid(), geteuid()) < 0) {
1073                         perror("setreuid");
1074                         exit(1);
1075                 }
1076 #else /* HAVE_OSF_SIA */
1077 #ifdef HAVE_CYGWIN
1078                 if (is_winnt) {
1079 #else
1080                 if (getuid() == 0 || geteuid() == 0) {
1081 #endif
1082 # ifdef HAVE_GETUSERATTR
1083                         set_limits_from_userattr(pw->pw_name);
1084 # endif /* HAVE_GETUSERATTR */
1085 # ifdef HAVE_LOGIN_CAP
1086                         if (setusercontext(lc, pw, pw->pw_uid,
1087                             (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
1088                                 perror("unable to set user context");
1089                                 exit(1);
1090                         }
1091 # else /* HAVE_LOGIN_CAP */
1092                         if (setlogin(pw->pw_name) < 0)
1093                                 error("setlogin failed: %s", strerror(errno));
1094                         if (setgid(pw->pw_gid) < 0) {
1095                                 perror("setgid");
1096                                 exit(1);
1097                         }
1098                         /* Initialize the group list. */
1099                         if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
1100                                 perror("initgroups");
1101                                 exit(1);
1102                         }
1103                         endgrent();
1104 #  ifdef WITH_IRIX_JOBS
1105                         jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive");
1106                         if (jid == -1) {
1107                                 fatal("Failed to create job container: %.100s",
1108                                       strerror(errno));
1109                         }
1110 #  endif /* WITH_IRIX_JOBS */
1111 #  ifdef WITH_IRIX_ARRAY
1112                         /* initialize array session */
1113                         if (jid == 0) {
1114                                 if (newarraysess() != 0)
1115                                         fatal("Failed to set up new array session: %.100s",
1116                                               strerror(errno));
1117                         }
1118 #  endif /* WITH_IRIX_ARRAY */
1119 #  ifdef WITH_IRIX_PROJECT
1120                         /* initialize irix project info */
1121                         if ((projid = getdfltprojuser(pw->pw_name)) == -1) {
1122                           debug("Failed to get project id, using projid 0");
1123                           projid = 0;
1124                         }
1125                         if (setprid(projid))
1126                           fatal("Failed to initialize project %d for %s: %.100s",
1127                                 (int)projid, pw->pw_name, strerror(errno));
1128 #  endif /* WITH_IRIX_PROJECT */
1129 #ifdef WITH_IRIX_AUDIT
1130                         if (sysconf(_SC_AUDIT)) {
1131                                 debug("Setting sat id to %d", (int) pw->pw_uid);
1132                                 if (satsetid(pw->pw_uid))
1133                                         debug("error setting satid: %.100s", strerror(errno));
1134                         }
1135 #endif /* WITH_IRIX_AUDIT */
1136
1137                         /* Permanently switch to the desired uid. */
1138                         permanently_set_uid(pw->pw_uid);
1139 # endif /* HAVE_LOGIN_CAP */
1140                 }
1141 #endif /* HAVE_OSF_SIA */
1142
1143 #ifdef HAVE_CYGWIN
1144                 if (is_winnt)
1145 #endif
1146                 if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
1147                         fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
1148         }
1149         /*
1150          * Get the shell from the password data.  An empty shell field is
1151          * legal, and means /bin/sh.
1152          */
1153         shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
1154 #ifdef HAVE_LOGIN_CAP
1155         shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
1156 #endif
1157
1158 #ifdef AFS
1159         /* Try to get AFS tokens for the local cell. */
1160         if (k_hasafs()) {
1161                 char cell[64];
1162
1163                 if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
1164                         krb_afslog(cell, 0);
1165
1166                 krb_afslog(0, 0);
1167         }
1168 #endif /* AFS */
1169
1170         /* Initialize the environment. */
1171         envsize = 100;
1172         env = xmalloc(envsize * sizeof(char *));
1173         env[0] = NULL;
1174
1175 #ifdef HAVE_CYGWIN
1176         /*
1177          * The Windows environment contains some setting which are
1178          * important for a running system. They must not be dropped.
1179          */
1180         copy_environment(&env, &envsize);
1181 #endif
1182
1183         if (!options.use_login) {
1184                 /* Set basic environment. */
1185                 child_set_env(&env, &envsize, "USER", pw->pw_name);
1186                 child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
1187                 child_set_env(&env, &envsize, "HOME", pw->pw_dir);
1188 #ifdef HAVE_LOGIN_CAP
1189                 (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
1190                 child_set_env(&env, &envsize, "PATH", getenv("PATH"));
1191 #else /* HAVE_LOGIN_CAP */
1192 # ifndef HAVE_CYGWIN
1193                 /*
1194                  * There's no standard path on Windows. The path contains
1195                  * important components pointing to the system directories,
1196                  * needed for loading shared libraries. So the path better
1197                  * remains intact here.
1198                  */
1199                 child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
1200 # endif /* HAVE_CYGWIN */
1201 #endif /* HAVE_LOGIN_CAP */
1202
1203                 snprintf(buf, sizeof buf, "%.200s/%.50s",
1204                          _PATH_MAILDIR, pw->pw_name);
1205                 child_set_env(&env, &envsize, "MAIL", buf);
1206
1207                 /* Normal systems set SHELL by default. */
1208                 child_set_env(&env, &envsize, "SHELL", shell);
1209         }
1210         if (getenv("TZ"))
1211                 child_set_env(&env, &envsize, "TZ", getenv("TZ"));
1212
1213         /* Set custom environment options from RSA authentication. */
1214         while (custom_environment) {
1215                 struct envstring *ce = custom_environment;
1216                 char *s = ce->s;
1217                 int i;
1218                 for (i = 0; s[i] != '=' && s[i]; i++);
1219                 if (s[i] == '=') {
1220                         s[i] = 0;
1221                         child_set_env(&env, &envsize, s, s + i + 1);
1222                 }
1223                 custom_environment = ce->next;
1224                 xfree(ce->s);
1225                 xfree(ce);
1226         }
1227
1228         snprintf(buf, sizeof buf, "%.50s %d %d",
1229                  get_remote_ipaddr(), get_remote_port(), get_local_port());
1230         child_set_env(&env, &envsize, "SSH_CLIENT", buf);
1231
1232         if (ttyname)
1233                 child_set_env(&env, &envsize, "SSH_TTY", ttyname);
1234         if (term)
1235                 child_set_env(&env, &envsize, "TERM", term);
1236         if (display)
1237                 child_set_env(&env, &envsize, "DISPLAY", display);
1238         if (original_command)
1239                 child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
1240                     original_command);
1241
1242 #ifdef _AIX
1243         if ((cp = getenv("AUTHSTATE")) != NULL)
1244                 child_set_env(&env, &envsize, "AUTHSTATE", cp);
1245         if ((cp = getenv("KRB5CCNAME")) != NULL)
1246                 child_set_env(&env, &envsize, "KRB5CCNAME", cp);
1247         read_environment_file(&env, &envsize, "/etc/environment");
1248 #endif
1249
1250 #ifdef KRB4
1251         {
1252                 extern char *ticket;
1253
1254                 if (ticket)
1255                         child_set_env(&env, &envsize, "KRBTKFILE", ticket);
1256         }
1257 #endif /* KRB4 */
1258
1259 #ifdef USE_PAM
1260         /* Pull in any environment variables that may have been set by PAM. */
1261         do_pam_environment(&env, &envsize);
1262 #endif /* USE_PAM */
1263
1264         if (xauthfile)
1265                 child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
1266         if (auth_get_socket_name() != NULL)
1267                 child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
1268                               auth_get_socket_name());
1269
1270         /* read $HOME/.ssh/environment. */
1271         if (!options.use_login) {
1272                 snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
1273                     pw->pw_dir);
1274                 read_environment_file(&env, &envsize, buf);
1275         }
1276         if (debug_flag) {
1277                 /* dump the environment */
1278                 fprintf(stderr, "Environment:\n");
1279                 for (i = 0; env[i]; i++)
1280                         fprintf(stderr, "  %.200s\n", env[i]);
1281         }
1282         /* we have to stash the hostname before we close our socket. */
1283         if (options.use_login)
1284                 hostname = get_remote_name_or_ip();
1285         /*
1286          * Close the connection descriptors; note that this is the child, and
1287          * the server will still have the socket open, and it is important
1288          * that we do not shutdown it.  Note that the descriptors cannot be
1289          * closed before building the environment, as we call
1290          * get_remote_ipaddr there.
1291          */
1292         if (packet_get_connection_in() == packet_get_connection_out())
1293                 close(packet_get_connection_in());
1294         else {
1295                 close(packet_get_connection_in());
1296                 close(packet_get_connection_out());
1297         }
1298         /*
1299          * Close all descriptors related to channels.  They will still remain
1300          * open in the parent.
1301          */
1302         /* XXX better use close-on-exec? -markus */
1303         channel_close_all();
1304
1305         /*
1306          * Close any extra file descriptors.  Note that there may still be
1307          * descriptors left by system functions.  They will be closed later.
1308          */
1309         endpwent();
1310
1311         /*
1312          * Close any extra open file descriptors so that we don\'t have them
1313          * hanging around in clients.  Note that we want to do this after
1314          * initgroups, because at least on Solaris 2.3 it leaves file
1315          * descriptors open.
1316          */
1317         for (i = 3; i < 64; i++)
1318                 close(i);
1319
1320         /* Change current directory to the user\'s home directory. */
1321         if (chdir(pw->pw_dir) < 0) {
1322                 fprintf(stderr, "Could not chdir to home directory %s: %s\n",
1323                         pw->pw_dir, strerror(errno));
1324 #ifdef HAVE_LOGIN_CAP
1325                 if (login_getcapbool(lc, "requirehome", 0))
1326                         exit(1);
1327 #endif
1328         }
1329
1330         /*
1331          * Must take new environment into use so that .ssh/rc, /etc/sshrc and
1332          * xauth are run in the proper environment.
1333          */
1334         environ = env;
1335
1336         /*
1337          * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
1338          * in this order).
1339          */
1340         if (!options.use_login) {
1341                 if (stat(_PATH_SSH_USER_RC, &st) >= 0) {
1342                         if (debug_flag)
1343                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_USER_RC);
1344
1345                         f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w");
1346                         if (f) {
1347                                 if (auth_proto != NULL && auth_data != NULL)
1348                                         fprintf(f, "%s %s\n", auth_proto, auth_data);
1349                                 pclose(f);
1350                         } else
1351                                 fprintf(stderr, "Could not run %s\n", _PATH_SSH_USER_RC);
1352                 } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
1353                         if (debug_flag)
1354                                 fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, _PATH_SSH_SYSTEM_RC);
1355
1356                         f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
1357                         if (f) {
1358                                 if (auth_proto != NULL && auth_data != NULL)
1359                                         fprintf(f, "%s %s\n", auth_proto, auth_data);
1360                                 pclose(f);
1361                         } else
1362                                 fprintf(stderr, "Could not run %s\n", _PATH_SSH_SYSTEM_RC);
1363                 } else if (options.xauth_location != NULL) {
1364                         /* Add authority data to .Xauthority if appropriate. */
1365                         if (auth_proto != NULL && auth_data != NULL) {
1366                                 char *screen = strchr(display, ':');
1367                                 if (debug_flag) {
1368                                         fprintf(stderr,
1369                                             "Running %.100s add %.100s %.100s %.100s\n",
1370                                             options.xauth_location, display,
1371                                             auth_proto, auth_data);
1372 #ifndef HAVE_CYGWIN /* Unix sockets are not supported */
1373                                         if (screen != NULL)
1374                                                 fprintf(stderr,
1375                                                     "Adding %.*s/unix%s %s %s\n",
1376                                                     (int)(screen-display), display,
1377                                                     screen, auth_proto, auth_data);
1378 #endif
1379                                 }
1380                                 snprintf(cmd, sizeof cmd, "%s -q -",
1381                                     options.xauth_location);
1382                                 f = popen(cmd, "w");
1383                                 if (f) {
1384                                         fprintf(f, "add %s %s %s\n", display,
1385                                             auth_proto, auth_data);
1386 #ifndef HAVE_CYGWIN /* Unix sockets are not supported */
1387                                         if (screen != NULL)
1388                                                 fprintf(f, "add %.*s/unix%s %s %s\n",
1389                                                     (int)(screen-display), display,
1390                                                     screen, auth_proto, auth_data);
1391 #endif
1392                                         pclose(f);
1393                                 } else {
1394                                         fprintf(stderr, "Could not run %s\n",
1395                                             cmd);
1396                                 }
1397                         }
1398                 }
1399                 /* Get the last component of the shell name. */
1400                 cp = strrchr(shell, '/');
1401                 if (cp)
1402                         cp++;
1403                 else
1404                         cp = shell;
1405         }
1406         /*
1407          * If we have no command, execute the shell.  In this case, the shell
1408          * name to be passed in argv[0] is preceded by '-' to indicate that
1409          * this is a login shell.
1410          */
1411         if (!command) {
1412                 if (!options.use_login) {
1413                         char buf[256];
1414
1415                         /*
1416                          * Check for mail if we have a tty and it was enabled
1417                          * in server options.
1418                          */
1419                         if (ttyname && options.check_mail) {
1420                                 char *mailbox;
1421                                 struct stat mailstat;
1422                                 mailbox = getenv("MAIL");
1423                                 if (mailbox != NULL) {
1424                                         if (stat(mailbox, &mailstat) != 0 ||
1425                                             mailstat.st_size == 0)
1426                                                 printf("No mail.\n");
1427                                         else if (mailstat.st_mtime < mailstat.st_atime)
1428                                                 printf("You have mail.\n");
1429                                         else
1430                                                 printf("You have new mail.\n");
1431                                 }
1432                         }
1433                         /* Start the shell.  Set initial character to '-'. */
1434                         buf[0] = '-';
1435                         strncpy(buf + 1, cp, sizeof(buf) - 1);
1436                         buf[sizeof(buf) - 1] = 0;
1437
1438                         /* Execute the shell. */
1439                         argv[0] = buf;
1440                         argv[1] = NULL;
1441                         execve(shell, argv, env);
1442
1443                         /* Executing the shell failed. */
1444                         perror(shell);
1445                         exit(1);
1446
1447                 } else {
1448                         /* Launch login(1). */
1449
1450                         execl(LOGIN_PROGRAM, "login", "-h", hostname,
1451                              "-p", "-f", "--", pw->pw_name, NULL);
1452
1453                         /* Login couldn't be executed, die. */
1454
1455                         perror("login");
1456                         exit(1);
1457                 }
1458         }
1459         /*
1460          * Execute the command using the user's shell.  This uses the -c
1461          * option to execute the command.
1462          */
1463         argv[0] = (char *) cp;
1464         argv[1] = "-c";
1465         argv[2] = (char *) command;
1466         argv[3] = NULL;
1467         execve(shell, argv, env);
1468         perror(shell);
1469         exit(1);
1470 }
1471
1472 Session *
1473 session_new(void)
1474 {
1475         int i;
1476         static int did_init = 0;
1477         if (!did_init) {
1478                 debug("session_new: init");
1479                 for(i = 0; i < MAX_SESSIONS; i++) {
1480                         sessions[i].used = 0;
1481                         sessions[i].self = i;
1482                 }
1483                 did_init = 1;
1484         }
1485         for(i = 0; i < MAX_SESSIONS; i++) {
1486                 Session *s = &sessions[i];
1487                 if (! s->used) {
1488                         s->pid = 0;
1489                         s->extended = 0;
1490                         s->chanid = -1;
1491                         s->ptyfd = -1;
1492                         s->ttyfd = -1;
1493                         s->term = NULL;
1494                         s->pw = NULL;
1495                         s->display = NULL;
1496                         s->screen = 0;
1497                         s->auth_data = NULL;
1498                         s->auth_proto = NULL;
1499                         s->used = 1;
1500                         s->pw = NULL;
1501                         debug("session_new: session %d", i);
1502                         return s;
1503                 }
1504         }
1505         return NULL;
1506 }
1507
1508 void
1509 session_dump(void)
1510 {
1511         int i;
1512         for(i = 0; i < MAX_SESSIONS; i++) {
1513                 Session *s = &sessions[i];
1514                 debug("dump: used %d session %d %p channel %d pid %d",
1515                     s->used,
1516                     s->self,
1517                     s,
1518                     s->chanid,
1519                     s->pid);
1520         }
1521 }
1522
1523 int
1524 session_open(int chanid)
1525 {
1526         Session *s = session_new();
1527         debug("session_open: channel %d", chanid);
1528         if (s == NULL) {
1529                 error("no more sessions");
1530                 return 0;
1531         }
1532         s->pw = auth_get_user();
1533         if (s->pw == NULL)
1534                 fatal("no user for session %i", s->self);
1535         debug("session_open: session %d: link with channel %d", s->self, chanid);
1536         s->chanid = chanid;
1537         return 1;
1538 }
1539
1540 Session *
1541 session_by_channel(int id)
1542 {
1543         int i;
1544         for(i = 0; i < MAX_SESSIONS; i++) {
1545                 Session *s = &sessions[i];
1546                 if (s->used && s->chanid == id) {
1547                         debug("session_by_channel: session %d channel %d", i, id);
1548                         return s;
1549                 }
1550         }
1551         debug("session_by_channel: unknown channel %d", id);
1552         session_dump();
1553         return NULL;
1554 }
1555
1556 Session *
1557 session_by_pid(pid_t pid)
1558 {
1559         int i;
1560         debug("session_by_pid: pid %d", pid);
1561         for(i = 0; i < MAX_SESSIONS; i++) {
1562                 Session *s = &sessions[i];
1563                 if (s->used && s->pid == pid)
1564                         return s;
1565         }
1566         error("session_by_pid: unknown pid %d", pid);
1567         session_dump();
1568         return NULL;
1569 }
1570
1571 int
1572 session_window_change_req(Session *s)
1573 {
1574         s->col = packet_get_int();
1575         s->row = packet_get_int();
1576         s->xpixel = packet_get_int();
1577         s->ypixel = packet_get_int();
1578         packet_done();
1579         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1580         return 1;
1581 }
1582
1583 int
1584 session_pty_req(Session *s)
1585 {
1586         u_int len;
1587         char *term_modes;       /* encoded terminal modes */
1588
1589         if (no_pty_flag)
1590                 return 0;
1591         if (s->ttyfd != -1)
1592                 return 0;
1593         s->term = packet_get_string(&len);
1594         s->col = packet_get_int();
1595         s->row = packet_get_int();
1596         s->xpixel = packet_get_int();
1597         s->ypixel = packet_get_int();
1598         term_modes = packet_get_string(&len);
1599         packet_done();
1600
1601         if (strcmp(s->term, "") == 0) {
1602                 xfree(s->term);
1603                 s->term = NULL;
1604         }
1605         /* Allocate a pty and open it. */
1606         if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) {
1607                 xfree(s->term);
1608                 s->term = NULL;
1609                 s->ptyfd = -1;
1610                 s->ttyfd = -1;
1611                 error("session_pty_req: session %d alloc failed", s->self);
1612                 xfree(term_modes);
1613                 return 0;
1614         }
1615         debug("session_pty_req: session %d alloc %s", s->self, s->tty);
1616         /*
1617          * Add a cleanup function to clear the utmp entry and record logout
1618          * time in case we call fatal() (e.g., the connection gets closed).
1619          */
1620         fatal_add_cleanup(pty_cleanup_proc, (void *)s);
1621         pty_setowner(s->pw, s->tty);
1622         /* Get window size from the packet. */
1623         pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
1624
1625         session_proctitle(s);
1626
1627         /* XXX parse and set terminal modes */
1628         xfree(term_modes);
1629         return 1;
1630 }
1631
1632 int
1633 session_subsystem_req(Session *s)
1634 {
1635         u_int len;
1636         int success = 0;
1637         char *subsys = packet_get_string(&len);
1638         int i;
1639
1640         packet_done();
1641         log("subsystem request for %s", subsys);
1642
1643         for (i = 0; i < options.num_subsystems; i++) {
1644                 if(strcmp(subsys, options.subsystem_name[i]) == 0) {
1645                         debug("subsystem: exec() %s", options.subsystem_command[i]);
1646                         do_exec_no_pty(s, options.subsystem_command[i], s->pw);
1647                         success = 1;
1648                 }
1649         }
1650
1651         if (!success)
1652                 log("subsystem request for %s failed, subsystem not found", subsys);
1653
1654         xfree(subsys);
1655         return success;
1656 }
1657
1658 int
1659 session_x11_req(Session *s)
1660 {
1661         int fd;
1662         if (no_x11_forwarding_flag) {
1663                 debug("X11 forwarding disabled in user configuration file.");
1664                 return 0;
1665         }
1666         if (!options.x11_forwarding) {
1667                 debug("X11 forwarding disabled in server configuration file.");
1668                 return 0;
1669         }
1670         if (xauthfile != NULL) {
1671                 debug("X11 fwd already started.");
1672                 return 0;
1673         }
1674
1675         debug("Received request for X11 forwarding with auth spoofing.");
1676         if (s->display != NULL)
1677                 packet_disconnect("Protocol error: X11 display already set.");
1678
1679         s->single_connection = packet_get_char();
1680         s->auth_proto = packet_get_string(NULL);
1681         s->auth_data = packet_get_string(NULL);
1682         s->screen = packet_get_int();
1683         packet_done();
1684
1685         s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
1686         if (s->display == NULL) {
1687                 xfree(s->auth_proto);
1688                 xfree(s->auth_data);
1689                 return 0;
1690         }
1691         xauthfile = xmalloc(MAXPATHLEN);
1692         strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
1693         temporarily_use_uid(s->pw->pw_uid);
1694         if (mkdtemp(xauthfile) == NULL) {
1695                 restore_uid();
1696                 error("private X11 dir: mkdtemp %s failed: %s",
1697                     xauthfile, strerror(errno));
1698                 xfree(xauthfile);
1699                 xauthfile = NULL;
1700                 xfree(s->auth_proto);
1701                 xfree(s->auth_data);
1702                 /* XXXX remove listening channels */
1703                 return 0;
1704         }
1705         strlcat(xauthfile, "/cookies", MAXPATHLEN);
1706         fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
1707         if (fd >= 0)
1708                 close(fd);
1709         restore_uid();
1710         fatal_add_cleanup(xauthfile_cleanup_proc, s);
1711         return 1;
1712 }
1713
1714 int
1715 session_shell_req(Session *s)
1716 {
1717         /* if forced_command == NULL, the shell is execed */
1718         char *shell = forced_command;
1719         packet_done();
1720         s->extended = 1;
1721         if (s->ttyfd == -1)
1722                 do_exec_no_pty(s, shell, s->pw);
1723         else
1724                 do_exec_pty(s, shell, s->pw);
1725         return 1;
1726 }
1727
1728 int
1729 session_exec_req(Session *s)
1730 {
1731         u_int len;
1732         char *command = packet_get_string(&len);
1733         packet_done();
1734         if (forced_command) {
1735                 original_command = command;
1736                 command = forced_command;
1737                 debug("Forced command '%.500s'", forced_command);
1738         }
1739         s->extended = 1;
1740         if (s->ttyfd == -1)
1741                 do_exec_no_pty(s, command, s->pw);
1742         else
1743                 do_exec_pty(s, command, s->pw);
1744         if (forced_command == NULL)
1745                 xfree(command);
1746         return 1;
1747 }
1748
1749 int
1750 session_auth_agent_req(Session *s)
1751 {
1752         static int called = 0;
1753         packet_done();
1754         if (no_agent_forwarding_flag) {
1755                 debug("session_auth_agent_req: no_agent_forwarding_flag");
1756                 return 0;
1757         }
1758         if (called) {
1759                 return 0;
1760         } else {
1761                 called = 1;
1762                 return auth_input_request_forwarding(s->pw);
1763         }
1764 }
1765
1766 void
1767 session_input_channel_req(int id, void *arg)
1768 {
1769         u_int len;
1770         int reply;
1771         int success = 0;
1772         char *rtype;
1773         Session *s;
1774         Channel *c;
1775
1776         rtype = packet_get_string(&len);
1777         reply = packet_get_char();
1778
1779         s = session_by_channel(id);
1780         if (s == NULL)
1781                 fatal("session_input_channel_req: channel %d: no session", id);
1782         c = channel_lookup(id);
1783         if (c == NULL)
1784                 fatal("session_input_channel_req: channel %d: bad channel", id);
1785
1786         debug("session_input_channel_req: session %d channel %d request %s reply %d",
1787             s->self, id, rtype, reply);
1788
1789         /*
1790          * a session is in LARVAL state until a shell
1791          * or programm is executed
1792          */
1793         if (c->type == SSH_CHANNEL_LARVAL) {
1794                 if (strcmp(rtype, "shell") == 0) {
1795                         success = session_shell_req(s);
1796                 } else if (strcmp(rtype, "exec") == 0) {
1797                         success = session_exec_req(s);
1798                 } else if (strcmp(rtype, "pty-req") == 0) {
1799                         success =  session_pty_req(s);
1800                 } else if (strcmp(rtype, "x11-req") == 0) {
1801                         success = session_x11_req(s);
1802                 } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
1803                         success = session_auth_agent_req(s);
1804                 } else if (strcmp(rtype, "subsystem") == 0) {
1805                         success = session_subsystem_req(s);
1806                 }
1807         }
1808         if (strcmp(rtype, "window-change") == 0) {
1809                 success = session_window_change_req(s);
1810         }
1811
1812         if (reply) {
1813                 packet_start(success ?
1814                     SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1815                 packet_put_int(c->remote_id);
1816                 packet_send();
1817         }
1818         xfree(rtype);
1819 }
1820
1821 void
1822 session_set_fds(Session *s, int fdin, int fdout, int fderr)
1823 {
1824         if (!compat20)
1825                 fatal("session_set_fds: called for proto != 2.0");
1826         /*
1827          * now that have a child and a pipe to the child,
1828          * we can activate our channel and register the fd's
1829          */
1830         if (s->chanid == -1)
1831                 fatal("no channel for session %d", s->self);
1832         channel_set_fds(s->chanid,
1833             fdout, fdin, fderr,
1834             fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
1835             1);
1836 }
1837
1838 void
1839 session_pty_cleanup(Session *s)
1840 {
1841         if (s == NULL || s->ttyfd == -1)
1842                 return;
1843
1844         debug("session_pty_cleanup: session %i release %s", s->self, s->tty);
1845
1846         /* Cancel the cleanup function. */
1847         fatal_remove_cleanup(pty_cleanup_proc, (void *)s);
1848
1849         /* Record that the user has logged out. */
1850         record_logout(s->pid, s->tty);
1851
1852         /* Release the pseudo-tty. */
1853         pty_release(s->tty);
1854
1855         /*
1856          * Close the server side of the socket pairs.  We must do this after
1857          * the pty cleanup, so that another process doesn't get this pty
1858          * while we're still cleaning up.
1859          */
1860         if (close(s->ptymaster) < 0)
1861                 error("close(s->ptymaster): %s", strerror(errno));
1862 }
1863
1864 void
1865 session_exit_message(Session *s, int status)
1866 {
1867         Channel *c;
1868         if (s == NULL)
1869                 fatal("session_close: no session");
1870         c = channel_lookup(s->chanid);
1871         if (c == NULL)
1872                 fatal("session_close: session %d: no channel %d",
1873                     s->self, s->chanid);
1874         debug("session_exit_message: session %d channel %d pid %d",
1875             s->self, s->chanid, s->pid);
1876
1877         if (WIFEXITED(status)) {
1878                 channel_request_start(s->chanid,
1879                     "exit-status", 0);
1880                 packet_put_int(WEXITSTATUS(status));
1881                 packet_send();
1882         } else if (WIFSIGNALED(status)) {
1883                 channel_request_start(s->chanid,
1884                     "exit-signal", 0);
1885                 packet_put_int(WTERMSIG(status));
1886 #ifdef WCOREDUMP
1887                 packet_put_char(WCOREDUMP(status));
1888 #else /* WCOREDUMP */
1889                 packet_put_char(0);
1890 #endif /* WCOREDUMP */
1891                 packet_put_cstring("");
1892                 packet_put_cstring("");
1893                 packet_send();
1894         } else {
1895                 /* Some weird exit cause.  Just exit. */
1896                 packet_disconnect("wait returned status %04x.", status);
1897         }
1898
1899         /* disconnect channel */
1900         debug("session_exit_message: release channel %d", s->chanid);
1901         channel_cancel_cleanup(s->chanid);
1902         /*
1903          * emulate a write failure with 'chan_write_failed', nobody will be
1904          * interested in data we write.
1905          * Note that we must not call 'chan_read_failed', since there could
1906          * be some more data waiting in the pipe.
1907          */
1908         if (c->ostate != CHAN_OUTPUT_CLOSED)
1909                 chan_write_failed(c);
1910         s->chanid = -1;
1911 }
1912
1913 void
1914 session_free(Session *s)
1915 {
1916         debug("session_free: session %d pid %d", s->self, s->pid);
1917         if (s->term)
1918                 xfree(s->term);
1919         if (s->display)
1920                 xfree(s->display);
1921         if (s->auth_data)
1922                 xfree(s->auth_data);
1923         if (s->auth_proto)
1924                 xfree(s->auth_proto);
1925         s->used = 0;
1926 }
1927
1928 void
1929 session_close(Session *s)
1930 {
1931         session_pty_cleanup(s);
1932         session_free(s);
1933         session_proctitle(s);
1934 }
1935
1936 void
1937 session_close_by_pid(pid_t pid, int status)
1938 {
1939         Session *s = session_by_pid(pid);
1940         if (s == NULL) {
1941                 debug("session_close_by_pid: no session for pid %d", s->pid);
1942                 return;
1943         }
1944         if (s->chanid != -1)
1945                 session_exit_message(s, status);
1946         session_close(s);
1947 }
1948
1949 /*
1950  * this is called when a channel dies before
1951  * the session 'child' itself dies
1952  */
1953 void
1954 session_close_by_channel(int id, void *arg)
1955 {
1956         Session *s = session_by_channel(id);
1957         if (s == NULL) {
1958                 debug("session_close_by_channel: no session for channel %d", id);
1959                 return;
1960         }
1961         /* disconnect channel */
1962         channel_cancel_cleanup(s->chanid);
1963         s->chanid = -1;
1964
1965         debug("session_close_by_channel: channel %d kill %d", id, s->pid);
1966         if (s->pid == 0) {
1967                 /* close session immediately */
1968                 session_close(s);
1969         } else {
1970                 /* notify child, delay session cleanup */
1971                 if (s->pid <= 1)
1972                         fatal("session_close_by_channel: Unsafe s->pid = %d", s->pid);
1973                 if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0)
1974                         error("session_close_by_channel: kill %d: %s",
1975                             s->pid, strerror(errno));
1976         }
1977 }
1978
1979 char *
1980 session_tty_list(void)
1981 {
1982         static char buf[1024];
1983         int i;
1984         buf[0] = '\0';
1985         for(i = 0; i < MAX_SESSIONS; i++) {
1986                 Session *s = &sessions[i];
1987                 if (s->used && s->ttyfd != -1) {
1988                         if (buf[0] != '\0')
1989                                 strlcat(buf, ",", sizeof buf);
1990                         strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf);
1991                 }
1992         }
1993         if (buf[0] == '\0')
1994                 strlcpy(buf, "notty", sizeof buf);
1995         return buf;
1996 }
1997
1998 void
1999 session_proctitle(Session *s)
2000 {
2001         if (s->pw == NULL)
2002                 error("no user for session %d", s->self);
2003         else
2004                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
2005 }
2006
2007 void
2008 do_authenticated2(Authctxt *authctxt)
2009 {
2010
2011         /*
2012          * Cancel the alarm we set to limit the time taken for
2013          * authentication.
2014          */
2015         alarm(0);
2016         if (startup_pipe != -1) {
2017                 close(startup_pipe);
2018                 startup_pipe = -1;
2019         }
2020 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
2021         if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
2022                 error("unable to get login class");
2023                 return;
2024         }
2025 #endif
2026         server_loop2();
2027         if (xauthfile)
2028                 xauthfile_cleanup_proc(NULL);
2029 }