- Merged OpenBSD IPv6 patch:

   - [sshd.c sshd.8 sshconnect.c ssh.h ssh.c servconf.h servconf.c scp.1]
     [scp.c packet.h packet.c login.c log.c canohost.c channels.c]
     [hostfile.c sshd_config]
     ipv6 support: mostly gethostbyname->getaddrinfo/getnameinfo, new
     features: sshd allows multiple ListenAddress and Port options. note
     that libwrap is not IPv6-ready. (based on patches from
     fujiwara@rcac.tdi.co.jp)
   - [ssh.c canohost.c]
     more hints (hints.ai_socktype=SOCK_STREAM) for getaddrinfo,
     from itojun@
   - [channels.c]
     listen on _all_ interfaces for X11-Fwd (hints.ai_flags = AI_PASSIVE)
   - [packet.h]
     allow auth-kerberos for IPv4 only
   - [scp.1 sshd.8 servconf.h scp.c]
     document -4, -6, and 'ssh -L 2022/::1/22'
   - [ssh.c]
     'ssh @host' is illegal (null user name), from
     karsten@gedankenpolizei.de
   - [sshconnect.c]
     better error message
   - [sshd.c]
     allow auth-kerberos for IPv4 only
 - Big IPv6 merge:
   - Cleanup overrun in sockaddr copying on RHL 6.1
   - Replacements for getaddrinfo, getnameinfo, etc based on versions
     from patch from KIKUCHI Takahiro <kick@kyoto.wide.ad.jp>
   - Replacement for missing structures on systems that lack IPv6
   - record_login needed to know about AF_INET6 addresses
   - Borrowed more code from OpenBSD: rresvport_af and requisites

1 files changed, 168 insertions, 81 deletions

diff --git a/sshd.c b/sshd.c
index 0cf664087..316723a83 100644
--- a/sshd.c
+++ b/sshd.c
@@ -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