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-rw-r--r--sshd.c249
1 files changed, 168 insertions, 81 deletions
diff --git a/sshd.c b/sshd.c
index 0cf66408..316723a8 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