-/* $OpenBSD: sshd.c,v 1.344 2006/08/05 07:52:52 dtucker Exp $ */
+/* $OpenBSD: sshd.c,v 1.345 2006/08/16 11:47:15 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
debug3("%s: done", __func__);
}
+/* Accept a connection from inetd */
+static void
+server_accept_inetd(int *sock_in, int *sock_out)
+{
+ int fd;
+
+ startup_pipe = -1;
+ if (rexeced_flag) {
+ close(REEXEC_CONFIG_PASS_FD);
+ *sock_in = *sock_out = dup(STDIN_FILENO);
+ if (!debug_flag) {
+ startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
+ close(REEXEC_STARTUP_PIPE_FD);
+ }
+ } else {
+ *sock_in = dup(STDIN_FILENO);
+ *sock_out = dup(STDOUT_FILENO);
+ }
+ /*
+ * We intentionally do not close the descriptors 0, 1, and 2
+ * as our code for setting the descriptors won't work if
+ * ttyfd happens to be one of those.
+ */
+ if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
+ dup2(fd, STDIN_FILENO);
+ dup2(fd, STDOUT_FILENO);
+ if (fd > STDOUT_FILENO)
+ close(fd);
+ }
+ debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out);
+}
+
+/*
+ * Listen for TCP connections
+ */
+static void
+server_listen(void)
+{
+ int ret, listen_sock, on = 1;
+ struct addrinfo *ai;
+ char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+
+ for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
+ if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
+ continue;
+ if (num_listen_socks >= MAX_LISTEN_SOCKS)
+ fatal("Too many listen sockets. "
+ "Enlarge MAX_LISTEN_SOCKS");
+ if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
+ ntop, sizeof(ntop), strport, sizeof(strport),
+ NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
+ error("getnameinfo failed: %.100s",
+ (ret != EAI_SYSTEM) ? gai_strerror(ret) :
+ strerror(errno));
+ continue;
+ }
+ /* Create socket for listening. */
+ listen_sock = socket(ai->ai_family, ai->ai_socktype,
+ ai->ai_protocol);
+ if (listen_sock < 0) {
+ /* kernel may not support ipv6 */
+ verbose("socket: %.100s", strerror(errno));
+ continue;
+ }
+ if (set_nonblock(listen_sock) == -1) {
+ close(listen_sock);
+ continue;
+ }
+ /*
+ * Set socket options.
+ * Allow local port reuse in TIME_WAIT.
+ */
+ if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
+ &on, sizeof(on)) == -1)
+ error("setsockopt SO_REUSEADDR: %s", strerror(errno));
+
+ debug("Bind to port %s on %s.", strport, ntop);
+
+ /* Bind the socket to the desired port. */
+ if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+ error("Bind to port %s on %s failed: %.200s.",
+ strport, ntop, strerror(errno));
+ close(listen_sock);
+ continue;
+ }
+ listen_socks[num_listen_socks] = listen_sock;
+ num_listen_socks++;
+
+ /* Start listening on the port. */
+ if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
+ fatal("listen on [%s]:%s: %.100s",
+ ntop, strport, strerror(errno));
+ logit("Server listening on %s port %s.", ntop, strport);
+ }
+ freeaddrinfo(options.listen_addrs);
+
+ if (!num_listen_socks)
+ fatal("Cannot bind any address.");
+}
+
+/*
+ * The main TCP accept loop. Note that, for the non-debug case, returns
+ * from this function are in a forked subprocess.
+ */
+static void
+server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
+{
+ fd_set *fdset;
+ int i, j, ret, maxfd;
+ int key_used = 0, startups = 0;
+ int startup_p[2] = { -1 , -1 };
+ struct sockaddr_storage from;
+ socklen_t fromlen;
+ pid_t pid;
+
+ /* setup fd set for accept */
+ fdset = NULL;
+ maxfd = 0;
+ for (i = 0; i < num_listen_socks; i++)
+ if (listen_socks[i] > maxfd)
+ maxfd = listen_socks[i];
+ /* pipes connected to unauthenticated childs */
+ startup_pipes = xcalloc(options.max_startups, sizeof(int));
+ for (i = 0; i < options.max_startups; i++)
+ startup_pipes[i] = -1;
+
+ /*
+ * Stay listening for connections until the system crashes or
+ * the daemon is killed with a signal.
+ */
+ for (;;) {
+ if (received_sighup)
+ sighup_restart();
+ if (fdset != NULL)
+ xfree(fdset);
+ fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS),
+ sizeof(fd_mask));
+
+ for (i = 0; i < num_listen_socks; i++)
+ FD_SET(listen_socks[i], fdset);
+ for (i = 0; i < options.max_startups; i++)
+ if (startup_pipes[i] != -1)
+ FD_SET(startup_pipes[i], fdset);
+
+ /* Wait in select until there is a connection. */
+ ret = select(maxfd+1, fdset, NULL, NULL, NULL);
+ if (ret < 0 && errno != EINTR)
+ error("select: %.100s", strerror(errno));
+ if (received_sigterm) {
+ logit("Received signal %d; terminating.",
+ (int) received_sigterm);
+ close_listen_socks();
+ unlink(options.pid_file);
+ exit(255);
+ }
+ if (key_used && key_do_regen) {
+ generate_ephemeral_server_key();
+ key_used = 0;
+ key_do_regen = 0;
+ }
+ if (ret < 0)
+ continue;
+
+ for (i = 0; i < options.max_startups; i++)
+ if (startup_pipes[i] != -1 &&
+ FD_ISSET(startup_pipes[i], fdset)) {
+ /*
+ * the read end of the pipe is ready
+ * if the child has closed the pipe
+ * after successful authentication
+ * or if the child has died
+ */
+ close(startup_pipes[i]);
+ startup_pipes[i] = -1;
+ startups--;
+ }
+ for (i = 0; i < num_listen_socks; i++) {
+ if (!FD_ISSET(listen_socks[i], fdset))
+ continue;
+ fromlen = sizeof(from);
+ *newsock = accept(listen_socks[i],
+ (struct sockaddr *)&from, &fromlen);
+ if (*newsock < 0) {
+ if (errno != EINTR && errno != EWOULDBLOCK)
+ error("accept: %.100s", strerror(errno));
+ continue;
+ }
+ if (unset_nonblock(*newsock) == -1) {
+ close(*newsock);
+ continue;
+ }
+ if (drop_connection(startups) == 1) {
+ debug("drop connection #%d", startups);
+ close(*newsock);
+ continue;
+ }
+ if (pipe(startup_p) == -1) {
+ close(*newsock);
+ continue;
+ }
+
+ if (rexec_flag && socketpair(AF_UNIX,
+ SOCK_STREAM, 0, config_s) == -1) {
+ error("reexec socketpair: %s",
+ strerror(errno));
+ close(*newsock);
+ close(startup_p[0]);
+ close(startup_p[1]);
+ continue;
+ }
+
+ for (j = 0; j < options.max_startups; j++)
+ if (startup_pipes[j] == -1) {
+ startup_pipes[j] = startup_p[0];
+ if (maxfd < startup_p[0])
+ maxfd = startup_p[0];
+ startups++;
+ break;
+ }
+
+ /*
+ * Got connection. Fork a child to handle it, unless
+ * we are in debugging mode.
+ */
+ if (debug_flag) {
+ /*
+ * In debugging mode. Close the listening
+ * socket, and start processing the
+ * connection without forking.
+ */
+ debug("Server will not fork when running in debugging mode.");
+ close_listen_socks();
+ *sock_in = *newsock;
+ *sock_out = *newsock;
+ close(startup_p[0]);
+ close(startup_p[1]);
+ startup_pipe = -1;
+ pid = getpid();
+ if (rexec_flag) {
+ send_rexec_state(config_s[0],
+ &cfg);
+ close(config_s[0]);
+ }
+ break;
+ }
+
+ /*
+ * Normal production daemon. Fork, and have
+ * the child process the connection. The
+ * parent continues listening.
+ */
+ if ((pid = fork()) == 0) {
+ /*
+ * Child. Close the listening and
+ * max_startup sockets. Start using
+ * the accepted socket. Reinitialize
+ * logging (since our pid has changed).
+ * We break out of the loop to handle
+ * the connection.
+ */
+ startup_pipe = startup_p[1];
+ close_startup_pipes();
+ close_listen_socks();
+ *sock_in = *newsock;
+ *sock_out = *newsock;
+ log_init(__progname,
+ options.log_level,
+ options.log_facility,
+ log_stderr);
+ if (rexec_flag)
+ close(config_s[0]);
+ break;
+ }
+
+ /* Parent. Stay in the loop. */
+ if (pid < 0)
+ error("fork: %.100s", strerror(errno));
+ else
+ debug("Forked child %ld.", (long)pid);
+
+ close(startup_p[1]);
+
+ if (rexec_flag) {
+ send_rexec_state(config_s[0], &cfg);
+ close(config_s[0]);
+ close(config_s[1]);
+ }
+
+ /*
+ * Mark that the key has been used (it
+ * was "given" to the child).
+ */
+ if ((options.protocol & SSH_PROTO_1) &&
+ key_used == 0) {
+ /* Schedule server key regeneration alarm. */
+ signal(SIGALRM, key_regeneration_alarm);
+ alarm(options.key_regeneration_time);
+ key_used = 1;
+ }
+
+ close(*newsock);
+
+ /*
+ * Ensure that our random state differs
+ * from that of the child
+ */
+ arc4random_stir();
+ }
+
+ /* child process check (or debug mode) */
+ if (num_listen_socks < 0)
+ break;
+ }
+}
+
+
/*
* Main program for the daemon.
*/
{
extern char *optarg;
extern int optind;
- int opt, j, i, on = 1;
+ int opt, i, on = 1;
int sock_in = -1, sock_out = -1, newsock = -1;
- pid_t pid;
- socklen_t fromlen;
- fd_set *fdset;
- struct sockaddr_storage from;
const char *remote_ip;
int remote_port;
- FILE *f;
- struct addrinfo *ai;
- char ntop[NI_MAXHOST], strport[NI_MAXSERV];
char *line;
- int listen_sock, maxfd;
- int startup_p[2] = { -1 , -1 }, config_s[2] = { -1 , -1 };
- int startups = 0;
+ int config_s[2] = { -1 , -1 };
Key *key;
Authctxt *authctxt;
- int ret, key_used = 0;
#ifdef HAVE_SECUREWARE
(void)set_auth_parameters(ac, av);
/* ignore SIGPIPE */
signal(SIGPIPE, SIG_IGN);
- /* Start listening for a socket, unless started from inetd. */
+ /* Get a connection, either from inetd or a listening TCP socket */
if (inetd_flag) {
- int fd;
+ server_accept_inetd(&sock_in, &sock_out);
- startup_pipe = -1;
- if (rexeced_flag) {
- close(REEXEC_CONFIG_PASS_FD);
- sock_in = sock_out = dup(STDIN_FILENO);
- if (!debug_flag) {
- startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
- close(REEXEC_STARTUP_PIPE_FD);
- }
- } else {
- sock_in = dup(STDIN_FILENO);
- sock_out = dup(STDOUT_FILENO);
- }
- /*
- * We intentionally do not close the descriptors 0, 1, and 2
- * as our code for setting the descriptors won't work if
- * ttyfd happens to be one of those.
- */
- if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
- dup2(fd, STDIN_FILENO);
- dup2(fd, STDOUT_FILENO);
- if (fd > STDOUT_FILENO)
- close(fd);
- }
- debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
if ((options.protocol & SSH_PROTO_1) &&
sensitive_data.server_key == NULL)
generate_ephemeral_server_key();
} else {
- for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
- if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
- continue;
- if (num_listen_socks >= MAX_LISTEN_SOCKS)
- fatal("Too many listen sockets. "
- "Enlarge MAX_LISTEN_SOCKS");
- if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
- ntop, sizeof(ntop), strport, sizeof(strport),
- NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
- error("getnameinfo failed: %.100s",
- (ret != EAI_SYSTEM) ? gai_strerror(ret) :
- strerror(errno));
- continue;
- }
- /* Create socket for listening. */
- listen_sock = socket(ai->ai_family, ai->ai_socktype,
- ai->ai_protocol);
- if (listen_sock < 0) {
- /* kernel may not support ipv6 */
- verbose("socket: %.100s", strerror(errno));
- continue;
- }
- if (set_nonblock(listen_sock) == -1) {
- close(listen_sock);
- continue;
- }
- /*
- * Set socket options.
- * Allow local port reuse in TIME_WAIT.
- */
- if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
- &on, sizeof(on)) == -1)
- error("setsockopt SO_REUSEADDR: %s", strerror(errno));
-
- debug("Bind to port %s on %s.", strport, ntop);
-
- /* Bind the socket to the desired port. */
- if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
- if (!ai->ai_next)
- error("Bind to port %s on %s failed: %.200s.",
- strport, ntop, strerror(errno));
- close(listen_sock);
- continue;
- }
- listen_socks[num_listen_socks] = listen_sock;
- num_listen_socks++;
-
- /* Start listening on the port. */
- if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
- fatal("listen on [%s]:%s: %.100s",
- ntop, strport, strerror(errno));
- logit("Server listening on %s port %s.", ntop, strport);
- }
- freeaddrinfo(options.listen_addrs);
-
- if (!num_listen_socks)
- fatal("Cannot bind any address.");
+ server_listen();
if (options.protocol & SSH_PROTO_1)
generate_ephemeral_server_key();
- /*
- * Arrange to restart on SIGHUP. The handler needs
- * listen_sock.
- */
signal(SIGHUP, sighup_handler);
-
+ signal(SIGCHLD, main_sigchld_handler);
signal(SIGTERM, sigterm_handler);
signal(SIGQUIT, sigterm_handler);
- /* Arrange SIGCHLD to be caught. */
- signal(SIGCHLD, main_sigchld_handler);
-
- /* Write out the pid file after the sigterm handler is setup */
+ /*
+ * Write out the pid file after the sigterm handler
+ * is setup and the listen sockets are bound
+ */
if (!debug_flag) {
- /*
- * Record our pid in /var/run/sshd.pid to make it
- * easier to kill the correct sshd. We don't want to
- * do this before the bind above because the bind will
- * fail if there already is a daemon, and this will
- * overwrite any old pid in the file.
- */
- f = fopen(options.pid_file, "wb");
+ FILE *f = fopen(options.pid_file, "w");
+
if (f == NULL) {
error("Couldn't create pid file \"%s\": %s",
options.pid_file, strerror(errno));
}
}
- /* setup fd set for listen */
- fdset = NULL;
- maxfd = 0;
- for (i = 0; i < num_listen_socks; i++)
- if (listen_socks[i] > maxfd)
- maxfd = listen_socks[i];
- /* pipes connected to unauthenticated childs */
- startup_pipes = xcalloc(options.max_startups, sizeof(int));
- for (i = 0; i < options.max_startups; i++)
- startup_pipes[i] = -1;
-
- /*
- * Stay listening for connections until the system crashes or
- * the daemon is killed with a signal.
- */
- for (;;) {
- if (received_sighup)
- sighup_restart();
- if (fdset != NULL)
- xfree(fdset);
- fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS),
- sizeof(fd_mask));
-
- for (i = 0; i < num_listen_socks; i++)
- FD_SET(listen_socks[i], fdset);
- for (i = 0; i < options.max_startups; i++)
- if (startup_pipes[i] != -1)
- FD_SET(startup_pipes[i], fdset);
-
- /* Wait in select until there is a connection. */
- ret = select(maxfd+1, fdset, NULL, NULL, NULL);
- if (ret < 0 && errno != EINTR)
- error("select: %.100s", strerror(errno));
- if (received_sigterm) {
- logit("Received signal %d; terminating.",
- (int) received_sigterm);
- close_listen_socks();
- unlink(options.pid_file);
- exit(255);
- }
- if (key_used && key_do_regen) {
- generate_ephemeral_server_key();
- key_used = 0;
- key_do_regen = 0;
- }
- if (ret < 0)
- continue;
-
- for (i = 0; i < options.max_startups; i++)
- if (startup_pipes[i] != -1 &&
- FD_ISSET(startup_pipes[i], fdset)) {
- /*
- * the read end of the pipe is ready
- * if the child has closed the pipe
- * after successful authentication
- * or if the child has died
- */
- close(startup_pipes[i]);
- startup_pipes[i] = -1;
- startups--;
- }
- for (i = 0; i < num_listen_socks; i++) {
- if (!FD_ISSET(listen_socks[i], fdset))
- continue;
- fromlen = sizeof(from);
- newsock = accept(listen_socks[i],
- (struct sockaddr *)&from, &fromlen);
- if (newsock < 0) {
- if (errno != EINTR && errno != EWOULDBLOCK)
- error("accept: %.100s", strerror(errno));
- continue;
- }
- if (unset_nonblock(newsock) == -1) {
- close(newsock);
- continue;
- }
- if (drop_connection(startups) == 1) {
- debug("drop connection #%d", startups);
- close(newsock);
- continue;
- }
- if (pipe(startup_p) == -1) {
- close(newsock);
- continue;
- }
-
- if (rexec_flag && socketpair(AF_UNIX,
- SOCK_STREAM, 0, config_s) == -1) {
- error("reexec socketpair: %s",
- strerror(errno));
- close(newsock);
- close(startup_p[0]);
- close(startup_p[1]);
- continue;
- }
-
- for (j = 0; j < options.max_startups; j++)
- if (startup_pipes[j] == -1) {
- startup_pipes[j] = startup_p[0];
- if (maxfd < startup_p[0])
- maxfd = startup_p[0];
- startups++;
- break;
- }
-
- /*
- * Got connection. Fork a child to handle it, unless
- * we are in debugging mode.
- */
- if (debug_flag) {
- /*
- * In debugging mode. Close the listening
- * socket, and start processing the
- * connection without forking.
- */
- debug("Server will not fork when running in debugging mode.");
- close_listen_socks();
- sock_in = newsock;
- sock_out = newsock;
- close(startup_p[0]);
- close(startup_p[1]);
- startup_pipe = -1;
- pid = getpid();
- if (rexec_flag) {
- send_rexec_state(config_s[0],
- &cfg);
- close(config_s[0]);
- }
- break;
- } else {
- /*
- * Normal production daemon. Fork, and have
- * the child process the connection. The
- * parent continues listening.
- */
- if ((pid = fork()) == 0) {
- /*
- * Child. Close the listening and
- * max_startup sockets. Start using
- * the accepted socket. Reinitialize
- * logging (since our pid has changed).
- * We break out of the loop to handle
- * the connection.
- */
- startup_pipe = startup_p[1];
- close_startup_pipes();
- close_listen_socks();
- sock_in = newsock;
- sock_out = newsock;
- log_init(__progname,
- options.log_level,
- options.log_facility,
- log_stderr);
- if (rexec_flag)
- close(config_s[0]);
- break;
- }
- }
-
- /* Parent. Stay in the loop. */
- if (pid < 0)
- error("fork: %.100s", strerror(errno));
- else
- debug("Forked child %ld.", (long)pid);
-
- close(startup_p[1]);
-
- if (rexec_flag) {
- send_rexec_state(config_s[0], &cfg);
- close(config_s[0]);
- close(config_s[1]);
- }
-
- /*
- * Mark that the key has been used (it
- * was "given" to the child).
- */
- if ((options.protocol & SSH_PROTO_1) &&
- key_used == 0) {
- /* Schedule server key regeneration alarm. */
- signal(SIGALRM, key_regeneration_alarm);
- alarm(options.key_regeneration_time);
- key_used = 1;
- }
-
- arc4random_stir();
- close(newsock);
- }
- /* child process check (or debug mode) */
- if (num_listen_socks < 0)
- break;
- }
+ /* Accept a connection and return in a forked child */
+ server_accept_loop(&sock_in, &sock_out,
+ &newsock, config_s);
}
/* This is the child processing a new connection. */
andersk / openssh.git / blobdiff