diff options
Diffstat (limited to 'crypto/openssh/session.c')
| -rw-r--r-- | crypto/openssh/session.c | 1516 |
1 files changed, 0 insertions, 1516 deletions
diff --git a/crypto/openssh/session.c b/crypto/openssh/session.c deleted file mode 100644 index 53d20c59cf25..000000000000 --- a/crypto/openssh/session.c +++ /dev/null @@ -1,1516 +0,0 @@ -/* - * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland - * All rights reserved - */ -/* - * SSH2 support by Markus Friedl. - * Copyright (c) 2000 Markus Friedl. All rights reserved. - */ - -#include "includes.h" -RCSID("$OpenBSD: session.c,v 1.12 2000/05/03 18:03:07 markus Exp $"); - -#include "xmalloc.h" -#include "ssh.h" -#include "pty.h" -#include "packet.h" -#include "buffer.h" -#include "cipher.h" -#include "mpaux.h" -#include "servconf.h" -#include "uidswap.h" -#include "compat.h" -#include "channels.h" -#include "nchan.h" - -#include "bufaux.h" -#include "ssh2.h" -#include "auth.h" - -/* types */ - -#define TTYSZ 64 -typedef struct Session Session; -struct Session { - int used; - int self; - int extended; - 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; -}; - -/* 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, struct passwd * pw); -void do_exec_no_pty(Session *s, const char *command, struct passwd * pw); - -void -do_child(const char *command, struct passwd * pw, const char *term, - const char *display, const char *auth_proto, - const char *auth_data, const char *ttyname); - -/* import */ -extern ServerOptions options; -extern char *__progname; -extern int log_stderr; -extern int debug_flag; - -/* Local Xauthority file. */ -static char *xauthfile; - -/* data */ -#define MAX_SESSIONS 10 -Session sessions[MAX_SESSIONS]; - -/* Flags set in auth-rsa from authorized_keys flags. These are set in auth-rsa.c. */ -int no_port_forwarding_flag = 0; -int no_agent_forwarding_flag = 0; -int no_x11_forwarding_flag = 0; -int no_pty_flag = 0; - -/* RSA authentication "command=" option. */ -char *forced_command = NULL; - -/* RSA authentication "environment=" options. */ -struct envstring *custom_environment = NULL; - -/* - * 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_authenticated(struct passwd * pw) -{ - Session *s; - int type; - int compression_level = 0, enable_compression_after_reply = 0; - int have_pty = 0; - char *command; - int n_bytes; - int plen; - unsigned int proto_len, data_len, dlen; - - /* - * Cancel the alarm we set to limit the time taken for - * authentication. - */ - alarm(0); - - /* - * Inform the channel mechanism that we are the server side and that - * the client may request to connect to any port at all. (The user - * could do it anyway, and we wouldn\'t know what is permitted except - * by the client telling us, so we can equally well trust the client - * not to request anything bogus.) - */ - if (!no_port_forwarding_flag) - channel_permit_all_opens(); - - s = session_new(); - s->pw = pw; - - /* - * We stay in this loop until the client requests to execute a shell - * or a command. - */ - for (;;) { - int 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 (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(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); - - session_proctitle(s); - - /* Indicate that we now have a pty. */ - success = 1; - have_pty = 1; - break; - - case SSH_CMSG_X11_REQUEST_FORWARDING: - if (!options.x11_forwarding) { - packet_send_debug("X11 forwarding disabled in server configuration file."); - break; - } -#ifdef XAUTH_PATH - if (no_x11_forwarding_flag) { - packet_send_debug("X11 forwarding not permitted for this authentication."); - break; - } - debug("Received request for X11 forwarding with auth spoofing."); - if (s->display != NULL) - packet_disconnect("Protocol error: X11 display already set."); - - s->auth_proto = packet_get_string(&proto_len); - s->auth_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) - s->screen = packet_get_int(); - else - s->screen = 0; - s->display = x11_create_display_inet(s->screen, options.x11_display_offset); - - if (s->display == NULL) - break; - - /* 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; - /* XXXX remove listening channels */ - break; - } - strlcat(xauthfile, "/cookies", MAXPATHLEN); - open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); - restore_uid(); - fatal_add_cleanup(xauthfile_cleanup_proc, NULL); - success = 1; - break; -#else /* XAUTH_PATH */ - packet_send_debug("No xauth program; cannot forward with spoofing."); - break; -#endif /* XAUTH_PATH */ - - case SSH_CMSG_AGENT_REQUEST_FORWARDING: - if (no_agent_forwarding_flag || compat13) { - debug("Authentication agent forwarding not permitted for this authentication."); - break; - } - debug("Received authentication agent forwarding request."); - auth_input_request_forwarding(pw); - success = 1; - break; - - case SSH_CMSG_PORT_FORWARD_REQUEST: - if (no_port_forwarding_flag) { - debug("Port forwarding not permitted for this authentication."); - break; - } - debug("Received TCP/IP port forwarding request."); - channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports); - success = 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: - /* Set interactive/non-interactive mode. */ - packet_set_interactive(have_pty || s->display != NULL, - options.keepalives); - - 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); - } - if (forced_command != NULL) { - command = forced_command; - debug("Forced command '%.500s'", forced_command); - } - if (have_pty) - do_exec_pty(s, command, pw); - else - do_exec_no_pty(s, command, pw); - - 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, struct passwd * pw) -{ - 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); - - /* 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(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL); - /* NOTREACHED */ - } - if (pid < 0) - packet_disconnect("fork failed: %.100s", strerror(errno)); - s->pid = pid; -#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->extended ? perr[0] : -1); - } else { - /* 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. - */ - if (compat20) { - session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -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, struct passwd * pw) -{ - FILE *f; - char buf[100], *time_string; - char line[256]; - const char *hostname; - int fdout, ptyfd, ttyfd, ptymaster; - int quiet_login; - pid_t pid; - socklen_t fromlen; - struct sockaddr_storage from; - struct stat st; - time_t last_login_time; - - if (s == NULL) - fatal("do_exec_pty: no session"); - ptyfd = s->ptyfd; - ttyfd = s->ttyfd; - - /* 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)); - } - - /* Fork the child. */ - if ((pid = fork()) == 0) { - pid = getpid(); - - /* 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); - -/* XXXX ? move to do_child() ??*/ - /* - * 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_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(); - } - } - /* Record that there was a login on that terminal. */ - record_login(pid, s->tty, 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; - - /* - * 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, s->term, s->display, s->auth_proto, s->auth_data, s->tty); - /* NOTREACHED */ - } - 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. */ - 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); - } -} - -/* - * 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); -} - -/* - * 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(const char *command, struct passwd * pw, const char *term, - const char *display, const char *auth_proto, - const char *auth_data, const char *ttyname) -{ - const char *shell, *cp = NULL; - char buf[256]; - FILE *f; - unsigned int envsize, i; - char **env; - extern char **environ; - struct stat st; - char *argv[10]; - - f = fopen("/etc/nologin", "r"); - if (f) { - /* /etc/nologin exists. Print its contents and exit. */ - while (fgets(buf, sizeof(buf), f)) - fputs(buf, stderr); - fclose(f); - if (pw->pw_uid != 0) - exit(254); - } - /* Set login name in the kernel. */ - if (setlogin(pw->pw_name) < 0) - error("setlogin failed: %s", strerror(errno)); - - /* Set uid, gid, and groups. */ - /* Login(1) does this as well, and it needs uid 0 for the "-h" - switch, so we let login(1) to this for us. */ - if (!options.use_login) { - if (getuid() == 0 || geteuid() == 0) { - if (setgid(pw->pw_gid) < 0) { - perror("setgid"); - exit(1); - } - /* Initialize the group list. */ - if (initgroups(pw->pw_name, pw->pw_gid) < 0) { - perror("initgroups"); - exit(1); - } - endgrent(); - - /* Permanently switch to the desired uid. */ - permanently_set_uid(pw->pw_uid); - } - if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) - fatal("Failed to set uids to %d.", (int) pw->pw_uid); - } - /* - * Get the shell from the password data. An empty shell field is - * legal, and means /bin/sh. - */ - shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; - -#ifdef AFS - /* Try to get AFS tokens for the local cell. */ - if (k_hasafs()) { - char cell[64]; - - if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) - krb_afslog(cell, 0); - - krb_afslog(0, 0); - } -#endif /* AFS */ - - /* Initialize the environment. */ - envsize = 100; - env = xmalloc(envsize * sizeof(char *)); - env[0] = NULL; - - if (!options.use_login) { - /* Set basic environment. */ - child_set_env(&env, &envsize, "USER", pw->pw_name); - child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); - child_set_env(&env, &envsize, "HOME", pw->pw_dir); - child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); - - snprintf(buf, sizeof buf, "%.200s/%.50s", - _PATH_MAILDIR, pw->pw_name); - child_set_env(&env, &envsize, "MAIL", buf); - - /* Normal systems set SHELL by default. */ - child_set_env(&env, &envsize, "SHELL", shell); - } - if (getenv("TZ")) - child_set_env(&env, &envsize, "TZ", getenv("TZ")); - - /* Set custom environment options from RSA authentication. */ - while (custom_environment) { - struct envstring *ce = custom_environment; - char *s = ce->s; - int i; - for (i = 0; s[i] != '=' && s[i]; i++); - if (s[i] == '=') { - s[i] = 0; - child_set_env(&env, &envsize, s, s + i + 1); - } - custom_environment = ce->next; - xfree(ce->s); - xfree(ce); - } - - snprintf(buf, sizeof buf, "%.50s %d %d", - get_remote_ipaddr(), get_remote_port(), get_local_port()); - child_set_env(&env, &envsize, "SSH_CLIENT", buf); - - if (ttyname) - child_set_env(&env, &envsize, "SSH_TTY", ttyname); - if (term) - child_set_env(&env, &envsize, "TERM", term); - if (display) - child_set_env(&env, &envsize, "DISPLAY", display); - -#ifdef KRB4 - { - extern char *ticket; - - if (ticket) - child_set_env(&env, &envsize, "KRBTKFILE", ticket); - } -#endif /* KRB4 */ - - if (xauthfile) - child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); - if (auth_get_socket_name() != NULL) - child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, - auth_get_socket_name()); - - /* read $HOME/.ssh/environment. */ - if (!options.use_login) { - snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir); - read_environment_file(&env, &envsize, buf); - } - if (debug_flag) { - /* dump the environment */ - fprintf(stderr, "Environment:\n"); - for (i = 0; env[i]; i++) - fprintf(stderr, " %.200s\n", env[i]); - } - /* - * 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); - - /* Change current directory to the user\'s home directory. */ - if (chdir(pw->pw_dir) < 0) - fprintf(stderr, "Could not chdir to home directory %s: %s\n", - pw->pw_dir, strerror(errno)); - - /* - * Must take new environment into use so that .ssh/rc, /etc/sshrc and - * xauth are run in the proper environment. - */ - environ = env; - - /* - * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first - * in this order). - */ - if (!options.use_login) { - if (stat(SSH_USER_RC, &st) >= 0) { - if (debug_flag) - fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC); - - f = popen("/bin/sh " SSH_USER_RC, "w"); - if (f) { - if (auth_proto != NULL && auth_data != NULL) - fprintf(f, "%s %s\n", auth_proto, auth_data); - pclose(f); - } else - fprintf(stderr, "Could not run %s\n", SSH_USER_RC); - } else if (stat(SSH_SYSTEM_RC, &st) >= 0) { - if (debug_flag) - fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC); - - f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); - if (f) { - if (auth_proto != NULL && auth_data != NULL) - fprintf(f, "%s %s\n", auth_proto, auth_data); - pclose(f); - } else - fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); - } -#ifdef XAUTH_PATH - else { - /* Add authority data to .Xauthority if appropriate. */ - if (auth_proto != NULL && auth_data != NULL) { - if (debug_flag) - fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n", - XAUTH_PATH, display, auth_proto, auth_data); - - f = popen(XAUTH_PATH " -q -", "w"); - if (f) { - fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data); - pclose(f); - } else - fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH); - } - } -#endif /* XAUTH_PATH */ - - /* Get the last component of the shell name. */ - cp = strrchr(shell, '/'); - if (cp) - cp++; - else - cp = shell; - } - /* - * If we have no command, execute the shell. In this case, the shell - * name to be passed in argv[0] is preceded by '-' to indicate that - * this is a login shell. - */ - if (!command) { - if (!options.use_login) { - char buf[256]; - - /* - * Check for mail if we have a tty and it was enabled - * in server options. - */ - if (ttyname && options.check_mail) { - char *mailbox; - struct stat mailstat; - mailbox = getenv("MAIL"); - if (mailbox != NULL) { - if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0) - printf("No mail.\n"); - else if (mailstat.st_mtime < mailstat.st_atime) - printf("You have mail.\n"); - else - printf("You have new mail.\n"); - } - } - /* Start the shell. Set initial character to '-'. */ - buf[0] = '-'; - strncpy(buf + 1, cp, sizeof(buf) - 1); - buf[sizeof(buf) - 1] = 0; - - /* Execute the shell. */ - argv[0] = buf; - argv[1] = NULL; - execve(shell, argv, env); - - /* Executing the shell failed. */ - perror(shell); - exit(1); - - } else { - /* Launch login(1). */ - - execl("/usr/bin/login", "login", "-h", get_remote_ipaddr(), - "-p", "-f", "--", pw->pw_name, NULL); - - /* Login couldn't be executed, die. */ - - perror("login"); - exit(1); - } - } - /* - * Execute the command using the user's shell. This uses the -c - * option to execute the command. - */ - argv[0] = (char *) cp; - argv[1] = "-c"; - argv[2] = (char *) command; - argv[3] = NULL; - execve(shell, argv, env); - perror(shell); - 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) { - s->pid = 0; - s->extended = 0; - s->chanid = -1; - s->ptyfd = -1; - s->ttyfd = -1; - s->term = NULL; - s->pw = NULL; - s->display = NULL; - s->screen = 0; - s->auth_data = NULL; - s->auth_proto = NULL; - s->used = 1; - s->pw = NULL; - 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; - } - s->pw = auth_get_user(); - if (s->pw == NULL) - fatal("no user for session %i", 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) -{ - unsigned int len; - char *term_modes; /* encoded terminal modes */ - - 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(); - term_modes = packet_get_string(&len); - packet_done(); - - 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); - xfree(term_modes); - 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); - - session_proctitle(s); - - /* XXX parse and set terminal modes */ - xfree(term_modes); - return 1; -} - -int -session_subsystem_req(Session *s) -{ - unsigned int len; - int success = 0; - char *subsys = packet_get_string(&len); - - packet_done(); - log("subsystem request for %s", subsys); - - xfree(subsys); - return success; -} - -int -session_x11_req(Session *s) -{ - 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->pw_uid); - 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); - open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); - restore_uid(); - fatal_add_cleanup(xauthfile_cleanup_proc, s); - return 1; -} - -void -session_input_channel_req(int id, void *arg) -{ - unsigned 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 - * or programm is executed - */ - if (c->type == SSH_CHANNEL_LARVAL) { - if (strcmp(rtype, "shell") == 0) { - packet_done(); - s->extended = 1; - if (s->ttyfd == -1) - do_exec_no_pty(s, NULL, s->pw); - else - do_exec_pty(s, NULL, s->pw); - success = 1; - } else if (strcmp(rtype, "exec") == 0) { - char *command = packet_get_string(&len); - packet_done(); - s->extended = 1; - if (s->ttyfd == -1) - do_exec_no_pty(s, command, s->pw); - else - do_exec_pty(s, command, s->pw); - xfree(command); - success = 1; - } 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, "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); -} - -void -session_pty_cleanup(Session *s) -{ - if (s == NULL || s->ttyfd == -1) - return; - - debug("session_pty_cleanup: session %i 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)); - packet_put_char(WCOREDUMP(status)); - 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(void) -{ - /* - * Cancel the alarm we set to limit the time taken for - * authentication. - */ - alarm(0); - server_loop2(); - if (xauthfile) - xauthfile_cleanup_proc(NULL); -} |