- dtucker@cvs.openbsd.org 2008/06/12 20:38:28

     [sshd.c sshconnect.c packet.h misc.c misc.h packet.c]
     Make keepalive timeouts apply while waiting for a packet, particularly
     during key renegotiation (bz #1363).  With djm and Matt Day, ok djm@

1 files changed, 76 insertions, 9 deletions

diff --git a/packet.c b/packet.c
index c0e91b2d6..9fd43ec68 100644
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.153 2008/05/19 06:14:02 djm Exp $ */
+/* $OpenBSD: packet.c,v 1.154 2008/06/12 20:38:28 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -138,6 +138,9 @@ static int after_authentication = 0;
 
 int keep_alive_timeouts = 0;
 
+/* Set to the maximum time that we will wait to send or receive a packet */
+static int packet_timeout_ms = -1;
+
 /* Session key information for Encryption and MAC */
 Newkeys *newkeys[MODE_MAX];
 static struct packet_state {
@@ -191,6 +194,19 @@ packet_set_connection(int fd_in, int fd_out)
         }
 }
 
+void
+packet_set_timeout(int timeout, int count)
+{
+        if (timeout == 0 || count == 0) {
+                packet_timeout_ms = -1;
+                return;
+        }
+        if ((INT_MAX / 1000) / count < timeout)
+                packet_timeout_ms = INT_MAX;
+        else
+                packet_timeout_ms = timeout * count * 1000;
+}
+
 /* Returns 1 if remote host is connected via socket, 0 if not. */
 
 int
@@ -891,10 +907,11 @@ packet_send(void)
 int
 packet_read_seqnr(u_int32_t *seqnr_p)
 {
-        int type, len;
+        int type, len, ret, ms_remain;
         fd_set *setp;
         char buf[8192];
         DBG(debug("packet_read()"));
+        struct timeval timeout, start, *timeoutp = NULL;
 
         setp = (fd_set *)xcalloc(howmany(connection_in+1, NFDBITS),
             sizeof(fd_mask));
@@ -925,11 +942,34 @@ packet_read_seqnr(u_int32_t *seqnr_p)
                     sizeof(fd_mask));
                 FD_SET(connection_in, setp);
 
+                if (packet_timeout_ms > 0) {
+                        ms_remain = packet_timeout_ms;
+                        timeoutp = &timeout;
+                }
                 /* Wait for some data to arrive. */
-                while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 &&
-                    (errno == EAGAIN || errno == EINTR))
-                        ;
-
+                for (;;) {
+                        if (packet_timeout_ms != -1) {
+                                ms_to_timeval(&timeout, ms_remain);
+                                gettimeofday(&start, NULL);
+                        }
+                        if ((ret = select(connection_in + 1, setp, NULL,
+                            NULL, timeoutp)) >= 0)
+                                break;
+                        if (errno != EAGAIN && errno != EINTR)
+                                break;
+                        if (packet_timeout_ms == -1)
+                                continue;
+                        ms_subtract_diff(&start, &ms_remain);
+                        if (ms_remain <= 0) {
+                                ret = 0;
+                                break;
+                        }
+                }
+                if (ret == 0) {
+                        logit("Connection to %.200s timed out while "
+                            "waiting to read", get_remote_ipaddr());
+                        cleanup_exit(255);
+                }
                 /* Read data from the socket. */
                 len = read(connection_in, buf, sizeof(buf));
                 if (len == 0) {
@@ -1452,6 +1492,8 @@ void
 packet_write_wait(void)
 {
         fd_set *setp;
+        int ret, ms_remain;
+        struct timeval start, timeout, *timeoutp = NULL;
 
         setp = (fd_set *)xcalloc(howmany(connection_out + 1, NFDBITS),
             sizeof(fd_mask));
@@ -1460,9 +1502,34 @@ packet_write_wait(void)
                 memset(setp, 0, howmany(connection_out + 1, NFDBITS) *
                     sizeof(fd_mask));
                 FD_SET(connection_out, setp);
-                while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 &&
-                    (errno == EAGAIN || errno == EINTR))
-                        ;
+
+                if (packet_timeout_ms > 0) {
+                        ms_remain = packet_timeout_ms;
+                        timeoutp = &timeout;
+                }
+                for (;;) {
+                        if (packet_timeout_ms != -1) {
+                                ms_to_timeval(&timeout, ms_remain);
+                                gettimeofday(&start, NULL);
+                        }
+                        if ((ret = select(connection_out + 1, NULL, setp,
+                            NULL, timeoutp)) >= 0)
+                                break;
+                        if (errno != EAGAIN && errno != EINTR)
+                                break;
+                        if (packet_timeout_ms == -1)
+                                continue;
+                        ms_subtract_diff(&start, &ms_remain);
+                        if (ms_remain <= 0) {
+                                ret = 0;
+                                break;
+                        }
+                }
+                if (ret == 0) {
+                        logit("Connection to %.200s timed out while "
+                            "waiting to write", get_remote_ipaddr());
+                        cleanup_exit(255);
+                }
                 packet_write_poll();
         }
         xfree(setp);