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authorDamien Miller <djm@mindrot.org>2000-07-11 17:31:38 +1000
committerDamien Miller <djm@mindrot.org>2000-07-11 17:31:38 +1000
commit3702396526a2569402696ff7d7c6d0fe2e5a447b (patch)
tree3ab056c59cd0c732ec179bd91be88d4e05b087fa /sshd.c
parentbc33bd44a2ef165dea1d974fc2d80b822ae08c2a (diff)
- (djm) OpenBSD CVS updates:
- markus@cvs.openbsd.org 2000/06/26 03:22:29 [authfd.c] cleanup, less cut&paste - markus@cvs.openbsd.org 2000/06/26 15:59:19 [servconf.c servconf.h session.c sshd.8 sshd.c] MaxStartups: limit number of unauthenticated connections, work by theo and me - deraadt@cvs.openbsd.org 2000/07/05 14:18:07 [session.c] use no_x11_forwarding_flag correctly; provos ok - provos@cvs.openbsd.org 2000/07/05 15:35:57 [sshd.c] typo - aaron@cvs.openbsd.org 2000/07/05 22:06:58 [scp.1 ssh-agent.1 ssh-keygen.1 sshd.8] Insert more missing .El directives. Our troff really should identify these and spit out a warning. - todd@cvs.openbsd.org 2000/07/06 21:55:04 [auth-rsa.c auth2.c ssh-keygen.c] clean code is good code - deraadt@cvs.openbsd.org 2000/07/07 02:14:29 [serverloop.c] sense of port forwarding flag test was backwards - provos@cvs.openbsd.org 2000/07/08 17:17:31 [compat.c readconf.c] replace strtok with strsep; from David Young <dyoung@onthejob.net> - deraadt@cvs.openbsd.org 2000/07/08 19:21:15 [auth.h] KNF - ho@cvs.openbsd.org 2000/07/08 19:27:33 [compat.c readconf.c] Better conditions for strsep() ending. - ho@cvs.openbsd.org 2000/07/10 10:27:05 [readconf.c] Get the correct message on errors. (niels@ ok) - ho@cvs.openbsd.org 2000/07/10 10:30:25 [cipher.c kex.c servconf.c] strtok() --> strsep(). (niels@ ok)
Diffstat (limited to 'sshd.c')
-rw-r--r--sshd.c167
1 files changed, 112 insertions, 55 deletions
diff --git a/sshd.c b/sshd.c
index 93d68404..fc8b17b9 100644
--- a/sshd.c
+++ b/sshd.c
@@ -14,7 +14,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.119 2000/06/22 16:32:27 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.121 2000/07/05 21:35:56 provos Exp $");
#include "xmalloc.h"
#include "rsa.h"
@@ -350,7 +350,7 @@ sshd_exchange_identification(int sock_in, int sock_out)
break;
}
if (remote_minor < 3) {
- packet_disconnect("Your ssh version is too old and"
+ packet_disconnect("Your ssh version is too old and "
"is no longer supported. Please install a newer version.");
} else if (remote_minor == 3) {
/* note that this disables agent-forwarding */
@@ -400,6 +400,9 @@ destroy_sensitive_data(void)
key_free(sensitive_data.dsa_host_key);
}
+int *startup_pipes = NULL; /* options.max_startup sized array of fd ints */
+int startup_pipe; /* in child */
+
/*
* Main program for the daemon.
*/
@@ -408,7 +411,7 @@ main(int ac, char **av)
{
extern char *optarg;
extern int optind;
- int opt, sock_in = 0, sock_out = 0, newsock, i, fdsetsz, on = 1;
+ int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
pid_t pid;
socklen_t fromlen;
int silent = 0;
@@ -421,6 +424,8 @@ main(int ac, char **av)
struct addrinfo *ai;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
int listen_sock, maxfd;
+ int startup_p[2];
+ int startups = 0;
init_rng();
@@ -746,6 +751,7 @@ main(int ac, char **av)
/* Arrange to restart on SIGHUP. The handler needs listen_sock. */
signal(SIGHUP, sighup_handler);
+
signal(SIGTERM, sigterm_handler);
signal(SIGQUIT, sigterm_handler);
@@ -753,12 +759,15 @@ main(int ac, char **av)
signal(SIGCHLD, main_sigchld_handler);
/* 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];
- fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
- fdset = (fd_set *)xmalloc(fdsetsz);
+ /* pipes connected to unauthenticated childs */
+ startup_pipes = xmalloc(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
@@ -767,80 +776,128 @@ main(int ac, char **av)
for (;;) {
if (received_sighup)
sighup_restart();
- /* Wait in select until there is a connection. */
+ if (fdset != NULL)
+ xfree(fdset);
+ fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
+ fdset = (fd_set *)xmalloc(fdsetsz);
memset(fdset, 0, fdsetsz);
+
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. */
if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) {
if (errno != EINTR)
error("select: %.100s", strerror(errno));
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 successfull 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 (fcntl(newsock, F_SETFL, 0) < 0) {
- error("newsock del O_NONBLOCK: %s", strerror(errno));
- continue;
- }
- /*
- * 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;
- pid = getpid();
- break;
- } else {
+ 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;
+ }
+ if (startups >= options.max_startups) {
+ close(newsock);
+ continue;
+ }
+ if (pipe(startup_p) == -1) {
+ close(newsock);
+ 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;
+ }
+
/*
- * Normal production daemon. Fork, and have
- * the child process the connection. The
- * parent continues listening.
+ * Got connection. Fork a child to handle it, unless
+ * we are in debugging mode.
*/
- if ((pid = fork()) == 0) {
+ if (debug_flag) {
/*
- * Child. Close the listening socket, and start using the
- * accepted socket. Reinitialize logging (since our pid has
- * changed). We break out of the loop to handle the connection.
+ * 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;
- log_init(av0, options.log_level, options.log_facility, log_stderr);
+ pid = getpid();
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];
+ for (j = 0; j < options.max_startups; j++)
+ if (startup_pipes[j] != -1)
+ close(startup_pipes[j]);
+ close_listen_socks();
+ sock_in = newsock;
+ sock_out = newsock;
+ log_init(av0, options.log_level, options.log_facility, log_stderr);
+ break;
+ }
}
- }
- /* Parent. Stay in the loop. */
- if (pid < 0)
- error("fork: %.100s", strerror(errno));
- else
- debug("Forked child %d.", pid);
+ /* Parent. Stay in the loop. */
+ if (pid < 0)
+ error("fork: %.100s", strerror(errno));
+ else
+ debug("Forked child %d.", pid);
- /* Mark that the key has been used (it was "given" to the child). */
- key_used = 1;
+ close(startup_p[1]);
- arc4random_stir();
+ /* Mark that the key has been used (it was "given" to the child). */
+ key_used = 1;
- /* Close the new socket (the child is now taking care of it). */
- close(newsock);
- } /* for (i = 0; i < num_listen_socks; i++) */
+ arc4random_stir();
+
+ /* Close the new socket (the child is now taking care of it). */
+ close(newsock);
+ }
/* child process check (or debug mode) */
if (num_listen_socks < 0)
break;