diff options
Diffstat (limited to 'sshd.c')
| -rw-r--r-- | sshd.c | 249 |
1 files changed, 168 insertions, 81 deletions
@@ -11,7 +11,7 @@ */ #include "includes.h" -RCSID("$Id: sshd.c,v 1.49 1999/12/30 04:08:44 damien Exp $"); +RCSID("$Id: sshd.c,v 1.50 2000/01/14 04:45:52 damien Exp $"); #include "xmalloc.h" #include "rsa.h" @@ -45,6 +45,12 @@ ServerOptions options; /* Name of the server configuration file. */ char *config_file_name = SERVER_CONFIG_FILE; +/* + * Flag indicating whether IPv4 or IPv6. This can be set on the command line. + * Default value is AF_UNSPEC means both IPv4 and IPv6. + */ +int IPv4or6 = AF_UNSPEC; + /* * Debug mode flag. This can be set on the command line. If debug * mode is enabled, extra debugging output will be sent to the system @@ -66,10 +72,12 @@ char *av0; char **saved_argv; /* - * This is set to the socket that the server is listening; this is used in - * the SIGHUP signal handler. + * The sockets that the server is listening; this is used in the SIGHUP + * signal handler. */ -int listen_sock; +#define MAX_LISTEN_SOCKS 16 +int listen_socks[MAX_LISTEN_SOCKS]; +int num_listen_socks = 0; /* * the client's version string, passed by sshd2 in compat mode. if != NULL, @@ -136,6 +144,18 @@ void do_child(const char *command, struct passwd * pw, const char *term, const char *auth_data, const char *ttyname); /* + * Close all listening sockets + */ +void +close_listen_socks(void) +{ + int i; + for (i = 0; i < num_listen_socks; i++) + close(listen_socks[i]); + num_listen_socks = -1; +} + +/* * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; * the effect is to reread the configuration file (and to regenerate * the server key). @@ -155,7 +175,7 @@ void sighup_restart() { log("Received SIGHUP; restarting."); - close(listen_sock); + close_listen_socks(); execv(saved_argv[0], saved_argv); log("RESTART FAILED: av0='%s', error: %s.", av0, strerror(errno)); exit(1); @@ -170,7 +190,7 @@ void sigterm_handler(int sig) { log("Received signal %d; terminating.", sig); - close(listen_sock); + close_listen_socks(); exit(255); } @@ -277,11 +297,12 @@ main(int ac, char **av) { extern char *optarg; extern int optind; - int opt, aux, sock_in, sock_out, newsock, i, pid, on = 1; + int opt, sock_in = 0, sock_out = 0, newsock, i, fdsetsz, pid, on = 1; + socklen_t fromlen; int remote_major, remote_minor; int silentrsa = 0; - struct pollfd fds; - struct sockaddr_in sin; + fd_set *fdset; + struct sockaddr_storage from; char buf[100]; /* Must not be larger than remote_version. */ char remote_version[100]; /* Must be at least as big as buf. */ const char *remote_ip; @@ -289,6 +310,9 @@ main(int ac, char **av) char *comment; FILE *f; struct linger linger; + struct addrinfo *ai; + char ntop[NI_MAXHOST], strport[NI_MAXSERV]; + int listen_sock, maxfd; /* Save argv[0]. */ saved_argv = av; @@ -301,8 +325,14 @@ main(int ac, char **av) initialize_server_options(&options); /* Parse command-line arguments. */ - while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:diqQ")) != EOF) { + while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:diqQ46")) != EOF) { switch (opt) { + case '4': + IPv4or6 = AF_INET; + break; + case '6': + IPv4or6 = AF_INET6; + break; case 'f': config_file_name = optarg; break; @@ -323,7 +353,10 @@ main(int ac, char **av) options.server_key_bits = atoi(optarg); break; case 'p': - options.port = atoi(optarg); + options.ports_from_cmdline = 1; + if (options.num_ports >= MAX_PORTS) + fatal("too many ports.\n"); + options.ports[options.num_ports++] = atoi(optarg); break; case 'g': options.login_grace_time = atoi(optarg); @@ -356,11 +389,22 @@ main(int ac, char **av) fprintf(stderr, " -g seconds Grace period for authentication (default: 300)\n"); fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n"); fprintf(stderr, " -h file File from which to read host key (default: %s)\n", - HOST_KEY_FILE); + HOST_KEY_FILE); + fprintf(stderr, " -4 Use IPv4 only\n"); + fprintf(stderr, " -6 Use IPv6 only\n"); exit(1); } } + /* + * Force logging to stderr until we have loaded the private host + * key (unless started from inetd) + */ + log_init(av0, + options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, + options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility, + !inetd_flag); + /* check if RSA support exists */ if (rsa_alive() == 0) { if (silentrsa == 0) @@ -380,18 +424,11 @@ main(int ac, char **av) fprintf(stderr, "Bad server key size.\n"); exit(1); } - if (options.port < 1 || options.port > 65535) { - fprintf(stderr, "Bad port number.\n"); - exit(1); - } /* Check that there are no remaining arguments. */ if (optind < ac) { fprintf(stderr, "Extra argument %s.\n", av[optind]); exit(1); } - /* Force logging to stderr while loading the private host key - unless started from inetd */ - log_init(av0, options.log_level, options.log_facility, !inetd_flag); debug("sshd version %.100s", SSH_VERSION); @@ -480,32 +517,66 @@ main(int ac, char **av) arc4random_stir(); log("RSA key generation complete."); } else { - /* Create socket for listening. */ - listen_sock = socket(AF_INET, SOCK_STREAM, 0); - if (listen_sock < 0) - fatal("socket: %.100s", strerror(errno)); - - /* Set socket options. We try to make the port reusable - and have it close as fast as possible without waiting - in unnecessary wait states on close. */ - setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, (void *) &on, - sizeof(on)); - linger.l_onoff = 1; - linger.l_linger = 5; - setsockopt(listen_sock, SOL_SOCKET, SO_LINGER, (void *) &linger, - sizeof(linger)); - - memset(&sin, 0, sizeof(sin)); - sin.sin_family = AF_INET; - sin.sin_addr = options.listen_addr; - sin.sin_port = htons(options.port); - - if (bind(listen_sock, (struct sockaddr *) & sin, sizeof(sin)) < 0) { - error("bind: %.100s", strerror(errno)); - shutdown(listen_sock, SHUT_RDWR); - close(listen_sock); - fatal("Bind to port %d failed.", options.port); + 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 (getnameinfo(ai->ai_addr, ai->ai_addrlen, + ntop, sizeof(ntop), strport, sizeof(strport), + NI_NUMERICHOST|NI_NUMERICSERV) != 0) { + error("getnameinfo failed"); + continue; + } + /* Create socket for listening. */ + listen_sock = socket(ai->ai_family, SOCK_STREAM, 0); + if (listen_sock < 0) { + /* kernel may not support ipv6 */ + verbose("socket: %.100s", strerror(errno)); + continue; + } + if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) { + error("listen_sock O_NONBLOCK: %s", strerror(errno)); + close(listen_sock); + continue; + } + /* + * Set socket options. We try to make the port + * reusable and have it close as fast as possible + * without waiting in unnecessary wait states on + * close. + */ + setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, + (void *) &on, sizeof(on)); + linger.l_onoff = 1; + linger.l_linger = 5; + setsockopt(listen_sock, SOL_SOCKET, SO_LINGER, + (void *) &linger, sizeof(linger)); + + 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. */ + log("Server listening on %s port %s.", ntop, strport); + if (listen(listen_sock, 5) < 0) + fatal("listen: %.100s", strerror(errno)); + } + freeaddrinfo(options.listen_addrs); + + if (!num_listen_socks) + fatal("Cannot bind any address."); + if (!debug_flag) { /* * Record our pid in /etc/sshd_pid to make it easier @@ -521,10 +592,6 @@ main(int ac, char **av) } } - log("Server listening on port %d.", options.port); - if (listen(listen_sock, 5) < 0) - fatal("listen: %.100s", strerror(errno)); - public_key = RSA_new(); sensitive_data.private_key = RSA_new(); @@ -546,6 +613,14 @@ main(int ac, char **av) /* Arrange SIGCHLD to be caught. */ signal(SIGCHLD, main_sigchld_handler); + /* setup fd set for listen */ + maxfd = 0; + for (i = 0; i < num_listen_socks; i++) + if (listen_socks[i] > maxfd) + maxfd = listen_socks[i]; + fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask); + fdset = (fd_set *)xmalloc(fdsetsz); + /* * Stay listening for connections until the system crashes or * the daemon is killed with a signal. @@ -553,26 +628,28 @@ main(int ac, char **av) for (;;) { if (received_sighup) sighup_restart(); - /* Wait in poll until there is a connection. */ - memset(&fds, 0, sizeof(fds)); - fds.fd = listen_sock; - fds.events = POLLIN; - if (poll(&fds, 1, -1) == -1) { - if (errno == EINTR) - continue; - fatal("poll: %.100s", strerror(errno)); - /*NOTREACHED*/ - } - if (fds.revents == 0) + /* Wait in select until there is a connection. */ + memset(fdset, 0, fdsetsz); + for (i = 0; i < num_listen_socks; i++) + FD_SET(listen_socks[i], fdset); + if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) { + if (errno != EINTR) + error("select: %.100s", strerror(errno)); continue; - aux = sizeof(sin); - newsock = accept(listen_sock, (struct sockaddr *) & sin, &aux); - if (received_sighup) - sighup_restart(); - if (newsock < 0) { - if (errno == EINTR) + } + for (i = 0; i < num_listen_socks; i++) { + if (!FD_ISSET(listen_socks[i], fdset)) continue; - error("accept: %.100s", strerror(errno)); + 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 (fcntl(newsock, F_SETFL, 0) < 0) { + error("newsock del O_NONBLOCK: %s", strerror(errno)); continue; } /* @@ -586,7 +663,7 @@ main(int ac, char **av) * connection without forking. */ debug("Server will not fork when running in debugging mode."); - close(listen_sock); + close_listen_socks(); sock_in = newsock; sock_out = newsock; pid = getpid(); @@ -603,7 +680,7 @@ main(int ac, char **av) * accepted socket. Reinitialize logging (since our pid has * changed). We break out of the loop to handle the connection. */ - close(listen_sock); + close_listen_socks(); sock_in = newsock; sock_out = newsock; log_init(av0, options.log_level, options.log_facility, log_stderr); @@ -624,6 +701,10 @@ main(int ac, char **av) /* Close the new socket (the child is now taking care of it). */ close(newsock); + } /* for (i = 0; i < num_listen_socks; i++) */ + /* child process check (or debug mode) */ + if (num_listen_socks < 0) + break; } } @@ -662,6 +743,7 @@ main(int ac, char **av) /* Check whether logins are denied from this host. */ #ifdef LIBWRAP + /* XXX LIBWRAP noes not know about IPv6 */ { struct request_info req; @@ -673,12 +755,11 @@ main(int ac, char **av) close(sock_out); refuse(&req); } - verbose("Connection from %.500s port %d", eval_client(&req), remote_port); +/*XXX IPv6 verbose("Connection from %.500s port %d", eval_client(&req), remote_port); */ } -#else +#endif /* LIBWRAP */ /* Log the connection. */ verbose("Connection from %.500s port %d", remote_ip, remote_port); -#endif /* LIBWRAP */ /* * We don\'t want to listen forever unless the other side @@ -700,12 +781,12 @@ main(int ac, char **av) snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", PROTOCOL_MAJOR, PROTOCOL_MINOR, SSH_VERSION); if (atomicio(write, sock_out, buf, strlen(buf)) != strlen(buf)) - fatal("Could not write ident string to %s.", get_remote_ipaddr()); + fatal("Could not write ident string to %s.", remote_ip); /* Read other side\'s version identification. */ for (i = 0; i < sizeof(buf) - 1; i++) { if (read(sock_in, &buf[i], 1) != 1) - fatal("Did not receive ident string from %s.", get_remote_ipaddr()); + fatal("Did not receive ident string from %s.", remote_ip); if (buf[i] == '\r') { buf[i] = '\n'; buf[i + 1] = 0; @@ -732,7 +813,7 @@ main(int ac, char **av) close(sock_in); close(sock_out); fatal("Bad protocol version identification '%.100s' from %s", - buf, get_remote_ipaddr()); + buf, remote_ip); } debug("Client protocol version %d.%d; client software version %.100s", remote_major, remote_minor, remote_version); @@ -743,8 +824,7 @@ main(int ac, char **av) close(sock_in); close(sock_out); fatal("Protocol major versions differ for %s: %d vs. %d", - get_remote_ipaddr(), - PROTOCOL_MAJOR, remote_major); + remote_ip, PROTOCOL_MAJOR, remote_major); } /* Check that the client has sufficiently high software version. */ if (remote_major == 1 && remote_minor < 3) @@ -769,6 +849,14 @@ main(int ac, char **av) options.rhosts_authentication = 0; options.rhosts_rsa_authentication = 0; } +#ifdef KRB4 + if (!packet_connection_is_ipv4() && + options.kerberos_authentication) { + debug("Kerberos Authentication disabled, only available for IPv4."); + options.kerberos_authentication = 0; + } +#endif /* KRB4 */ + packet_set_nonblocking(); /* Handle the connection. */ @@ -1935,8 +2023,8 @@ do_exec_pty(const char *command, int ptyfd, int ttyfd, char line[256]; struct stat st; int quiet_login; - struct sockaddr_in from; - int fromlen; + struct sockaddr_storage from; + socklen_t fromlen; struct pty_cleanup_context cleanup_context; /* Get remote host name. */ @@ -1997,7 +2085,7 @@ do_exec_pty(const char *command, int ptyfd, int ttyfd, } /* Record that there was a login on that terminal. */ record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname, - &from); + (struct sockaddr *)&from); /* Check if .hushlogin exists. */ snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir); @@ -2318,7 +2406,7 @@ do_child(const char *command, struct passwd * pw, const char *term, } snprintf(buf, sizeof buf, "%.50s %d %d", - get_remote_ipaddr(), get_remote_port(), options.port); + get_remote_ipaddr(), get_remote_port(), get_local_port()); child_set_env(&env, &envsize, "SSH_CLIENT", buf); if (ttyname) @@ -2385,7 +2473,6 @@ do_child(const char *command, struct passwd * pw, const char *term, * descriptors left by system functions. They will be closed later. */ endpwent(); - endhostent(); /* * Close any extra open file descriptors so that we don\'t have them |