- /* Get TERM from the packet. Note that the value may be of arbitrary length. */
- term = packet_get_string(&dlen);
- packet_integrity_check(dlen, strlen(term), type);
-
- /* Remaining bytes */
- n_bytes = plen - (4 + dlen + 4 * 4);
-
- if (strcmp(term, "") == 0) {
- xfree(term);
- term = NULL;
- }
-
- /* Get window size from the packet. */
- row = packet_get_int();
- col = packet_get_int();
- xpixel = packet_get_int();
- ypixel = packet_get_int();
- pty_change_window_size(ptyfd, row, col, xpixel, ypixel);
-
- /* Get tty modes from the packet. */
- tty_parse_modes(ttyfd, &n_bytes);
- packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
-
- /* Indicate that we now have a pty. */
- have_pty = 1;
- break;
-
- case SSH_CMSG_X11_REQUEST_FORWARDING:
- if (!options.x11_forwarding) {
- packet_send_debug("X11 forwarding disabled in server configuration file.");
- goto fail;
- }
-#ifdef XAUTH_PATH
- if (no_x11_forwarding_flag) {
- packet_send_debug("X11 forwarding not permitted for this authentication.");
- goto fail;
- }
- debug("Received request for X11 forwarding with auth spoofing.");
- if (display)
- packet_disconnect("Protocol error: X11 display already set.");
- {
- unsigned int proto_len, data_len;
- proto = packet_get_string(&proto_len);
- data = packet_get_string(&data_len);
- packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type);
- }
- if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER)
- screen = packet_get_int();
- else
- screen = 0;
- display = x11_create_display_inet(screen, options.x11_display_offset);
- if (!display)
- goto fail;
-
- /* Setup to always have a local .Xauthority. */
- xauthfile = xmalloc(MAXPATHLEN);
- strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
- temporarily_use_uid(pw->pw_uid);
- if (mkdtemp(xauthfile) == NULL) {
- restore_uid();
- error("private X11 dir: mkdtemp %s failed: %s",
- xauthfile, strerror(errno));
- xfree(xauthfile);
- xauthfile = NULL;
- goto fail;
- }
- strlcat(xauthfile, "/cookies", MAXPATHLEN);
- open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
- restore_uid();
- fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
- break;
-#else /* XAUTH_PATH */
- packet_send_debug("No xauth program; cannot forward with spoofing.");
- goto fail;
-#endif /* XAUTH_PATH */
-
- case SSH_CMSG_AGENT_REQUEST_FORWARDING:
- if (no_agent_forwarding_flag || compat13) {
- debug("Authentication agent forwarding not permitted for this authentication.");
- goto fail;
- }
- debug("Received authentication agent forwarding request.");
- auth_input_request_forwarding(pw);
- break;
-
- case SSH_CMSG_PORT_FORWARD_REQUEST:
- if (no_port_forwarding_flag) {
- debug("Port forwarding not permitted for this authentication.");
- goto fail;
- }
- debug("Received TCP/IP port forwarding request.");
- channel_input_port_forward_request(pw->pw_uid == 0);
- break;
-
- case SSH_CMSG_MAX_PACKET_SIZE:
- if (packet_set_maxsize(packet_get_int()) < 0)
- goto fail;
- break;
-
- case SSH_CMSG_EXEC_SHELL:
- /* Set interactive/non-interactive mode. */
- packet_set_interactive(have_pty || display != NULL,
- options.keepalives);
-
- if (forced_command != NULL)
- goto do_forced_command;
- debug("Forking shell.");
- packet_integrity_check(plen, 0, type);
- if (have_pty)
- do_exec_pty(NULL, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
- else
- do_exec_no_pty(NULL, pw, display, proto, data);
- return;
-
- case SSH_CMSG_EXEC_CMD:
- /* Set interactive/non-interactive mode. */
- packet_set_interactive(have_pty || display != NULL,
- options.keepalives);
-
- if (forced_command != NULL)
- goto do_forced_command;
- /* Get command from the packet. */
- {
- unsigned int dlen;
- command = packet_get_string(&dlen);
- debug("Executing command '%.500s'", command);
- packet_integrity_check(plen, 4 + dlen, type);
- }
- if (have_pty)
- do_exec_pty(command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
- else
- do_exec_no_pty(command, pw, display, proto, data);
- xfree(command);
- 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);
- goto fail;
- }
-
- /* The request was successfully processed. */
- packet_start(SSH_SMSG_SUCCESS);
- 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);
- }
- continue;
-
-fail:
- /* The request failed. */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- continue;
-
-do_forced_command:
- /*
- * There is a forced command specified for this login.
- * Execute it.
- */
- debug("Executing forced command: %.900s", forced_command);
- if (have_pty)
- do_exec_pty(forced_command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
- else
- do_exec_no_pty(forced_command, pw, display, proto, data);
- return;
- }
-}
-
-/*
- * 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(const char *command, struct passwd * pw,
- const char *display, const char *auth_proto,
- const char *auth_data)
-{
- 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 */
-
- setproctitle("%s@notty", pw->pw_name);
-
-#ifdef USE_PAM
- do_pam_setcred();
-#endif /* USE_PAM */
-
- /* Fork the child. */
- if ((pid = fork()) == 0) {
- /* Child. Reinitialize the log since the pid has changed. */
- log_init(av0, 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(command, pw, NULL, display, auth_proto, auth_data, NULL);
- /* NOTREACHED */
- }
- if (pid < 0)
- packet_disconnect("fork failed: %.100s", strerror(errno));
-#ifdef USE_PIPES
- /* We are the parent. Close the child sides of the pipes. */
- close(pin[0]);
- close(pout[1]);
- close(perr[1]);
-
- /* Enter the interactive session. */
- server_loop(pid, pin[1], pout[0], perr[0]);
- /* server_loop has closed pin[1], pout[1], and perr[1]. */
-#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.
- */
- 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(const char *command, int ptyfd, int ttyfd,
- const char *ttyname, struct passwd * pw, const char *term,
- const char *display, const char *auth_proto,
- const char *auth_data)
-{
- int pid, fdout;
- int ptymaster;
- const char *hostname;
- time_t last_login_time;
- char buf[100], *time_string;
- FILE *f;
- char line[256];
- struct stat st;
- int quiet_login;
- struct sockaddr_storage from;
- socklen_t fromlen;
- struct pty_cleanup_context cleanup_context;
-
- /* Get remote host name. */
- hostname = get_canonical_hostname();
-
- /*
- * Get the time when the user last logged in. Buf will be set to
- * contain the hostname the last login was from.
- */
- if (!options.use_login) {
- last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
- buf, sizeof(buf));
- }
- setproctitle("%s@%s", pw->pw_name, strrchr(ttyname, '/') + 1);
-
-#ifdef USE_PAM
- do_pam_session(pw->pw_name, ttyname);
- do_pam_setcred();
-#endif /* USE_PAM */
-
- /* Fork the child. */
- if ((pid = fork()) == 0) {
- pid = getpid();
-
- /* Child. Reinitialize the log because the pid has
- changed. */
- log_init(av0, 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, ttyname);
-
- /* 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);
-
- /*
- * Get IP address of client. This is needed because we want
- * to record where the user logged in from. If the
- * connection is not a socket, let the ip address be 0.0.0.0.
- */
- memset(&from, 0, sizeof(from));
- if (packet_get_connection_in() == packet_get_connection_out()) {
- fromlen = sizeof(from);
- if (getpeername(packet_get_connection_in(),
- (struct sockaddr *) & from, &fromlen) < 0) {
- debug("getpeername: %.100s", strerror(errno));
- fatal_cleanup();
- }
- }
- /* Record that there was a login on that terminal. */
- record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname,
- (struct sockaddr *)&from);
-
- /* Check if .hushlogin exists. */
- snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir);
- quiet_login = stat(line, &st) >= 0;
-
-#ifdef USE_PAM
- if (!quiet_login)
- print_pam_messages();
-#endif /* USE_PAM */
-
- /*
- * If the user has logged in before, display the time of last
- * login. However, don't display anything extra if a command
- * has been specified (so that ssh can be used to execute
- * commands on a remote machine without users knowing they
- * are going to another machine). Login(1) will do this for
- * us as well, so check if login(1) is used
- */
- if (command == NULL && last_login_time != 0 && !quiet_login &&
- !options.use_login) {
- /* Convert the date to a string. */
- time_string = ctime(&last_login_time);
- /* Remove the trailing newline. */
- if (strchr(time_string, '\n'))
- *strchr(time_string, '\n') = 0;
- /* Display the last login time. Host if displayed
- if known. */
- if (strcmp(buf, "") == 0)
- printf("Last login: %s\r\n", time_string);
- else
- printf("Last login: %s from %s\r\n", time_string, buf);
- }
- /*
- * Print /etc/motd unless a command was specified or printing
- * it was disabled in server options or login(1) will be
- * used. Note that some machines appear to print it in
- * /etc/profile or similar.
- */
- if (command == NULL && options.print_motd && !quiet_login &&
- !options.use_login) {
- /* Print /etc/motd if it exists. */
- f = fopen("/etc/motd", "r");
- if (f) {
- while (fgets(line, sizeof(line), f))
- fputs(line, stdout);
- fclose(f);
- }
- }
- /* Do common processing for the child, such as execing the command. */
- do_child(command, pw, term, display, auth_proto, auth_data, ttyname);
- /* NOTREACHED */
- }
- if (pid < 0)
- packet_disconnect("fork failed: %.100s", strerror(errno));
- /* Parent. Close the slave side of the pseudo tty. */
- close(ttyfd);
-
- /*
- * Add a cleanup function to clear the utmp entry and record logout
- * time in case we call fatal() (e.g., the connection gets closed).
- */
- cleanup_context.pid = pid;
- cleanup_context.ttyname = ttyname;
- fatal_add_cleanup(pty_cleanup_proc, (void *) &cleanup_context);
- fatal_remove_cleanup(pty_release_proc, (void *) ttyname);
-
- /*
- * 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));
-
- /* Enter interactive session. */
- server_loop(pid, ptyfd, fdout, -1);
- /* server_loop _has_ closed ptyfd and fdout. */
-
- /* Cancel the cleanup function. */
- fatal_remove_cleanup(pty_cleanup_proc, (void *) &cleanup_context);
-
- /* Record that the user has logged out. */
- record_logout(pid, ttyname);
-
- /* Release the pseudo-tty. */
- pty_release(ttyname);
-
- /*
- * 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(ptymaster) < 0)
- error("close(ptymaster): %s", strerror(errno));
-}
-
-/*
- * Sets the value of the given variable in the environment. If the variable
- * already exists, its value is overriden.
- */
-void
-child_set_env(char ***envp, unsigned int *envsizep, const char *name,
- const char *value)
-{
- unsigned int i, namelen;
- char **env;
-
- /*
- * Find the slot where the value should be stored. If the variable
- * already exists, we reuse the slot; otherwise we append a new slot
- * at the end of the array, expanding if necessary.
- */
- env = *envp;
- namelen = strlen(name);
- for (i = 0; env[i]; i++)
- if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
- break;
- if (env[i]) {
- /* Reuse the slot. */
- xfree(env[i]);
- } else {
- /* New variable. Expand if necessary. */
- if (i >= (*envsizep) - 1) {
- (*envsizep) += 50;
- env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
- }
- /* Need to set the NULL pointer at end of array beyond the new slot. */
- env[i + 1] = NULL;
- }
-
- /* Allocate space and format the variable in the appropriate slot. */
- env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
- snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
-}
-
-/*
- * Reads environment variables from the given file and adds/overrides them
- * into the environment. If the file does not exist, this does nothing.
- * Otherwise, it must consist of empty lines, comments (line starts with '#')
- * and assignments of the form name=value. No other forms are allowed.
- */
-void
-read_environment_file(char ***env, unsigned int *envsize,
- const char *filename)
-{
- FILE *f;
- char buf[4096];
- char *cp, *value;
-
- f = fopen(filename, "r");
- if (!f)
- return;
-
- while (fgets(buf, sizeof(buf), f)) {
- for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
- ;
- if (!*cp || *cp == '#' || *cp == '\n')
- continue;
- if (strchr(cp, '\n'))
- *strchr(cp, '\n') = '\0';
- value = strchr(cp, '=');
- if (value == NULL) {
- fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
- continue;
- }
- /* Replace the equals sign by nul, and advance value to the value string. */
- *value = '\0';
- value++;
- child_set_env(env, envsize, cp, value);
- }
- fclose(f);
-}
-
-#ifdef USE_PAM
-/*
- * Sets any environment variables which have been specified by PAM
- */
-void do_pam_environment(char ***env, int *envsize)