upstream commit

avoid fatal() calls in packet code makes ssh-keyscan more
 reliable against server failures ok dtucker@ markus@

7 files changed, 54 insertions, 29 deletions

diff --git a/opacket.c b/opacket.c
index 63b419d5c..a137b5a8a 100644
--- a/opacket.c
+++ b/opacket.c
@@ -255,8 +255,20 @@ packet_read_seqnr(u_int32_t *seqnr)
         u_char type;
         int r;
 
-        if ((r = ssh_packet_read_seqnr(active_state, &type, seqnr)))
-                fatal("%s: %s", __func__, ssh_err(r));
+        if ((r = ssh_packet_read_seqnr(active_state, &type, seqnr)) != 0) {
+                switch (r) {
+                case SSH_ERR_CONN_CLOSED:
+                        logit("Connection closed by %.200s",
+                            ssh_remote_ipaddr(active_state));
+                        cleanup_exit(255);
+                case SSH_ERR_CONN_TIMEOUT:
+                        logit("Connection to %.200s timed out while "
+                            "waiting to read", ssh_remote_ipaddr(active_state));
+                        cleanup_exit(255);
+                default:
+                        fatal("%s: %s", __func__, ssh_err(r));
+                }
+        }
         return type;
 }
 
@@ -277,3 +289,12 @@ packet_close(void)
         ssh_packet_close(active_state);
         active_state = NULL;
 }
+
+void
+packet_process_incoming(const char *buf, u_int len)
+{
+        int r;
+
+        if ((r = ssh_packet_process_incoming(active_state, buf, len)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
+}
diff --git a/opacket.h b/opacket.h
index 1e15626eb..261ed1f81 100644
--- a/opacket.h
+++ b/opacket.h
@@ -44,6 +44,7 @@ void	 packet_restore_state(void);
 void     packet_set_connection(int, int);
 int      packet_read_seqnr(u_int32_t *);
 int      packet_read_poll_seqnr(u_int32_t *);
+void     packet_process_incoming(const char *buf, u_int len);
 #define packet_set_timeout(timeout, count) \
         ssh_packet_set_timeout(active_state, (timeout), (count))
 #define packet_connection_is_on_socket() \
@@ -86,8 +87,6 @@ int	 packet_read_poll_seqnr(u_int32_t *);
         ssh_packet_read(active_state)
 #define packet_read_expect(expected_type) \
         ssh_packet_read_expect(active_state, (expected_type))
-#define packet_process_incoming(buf, len) \
-        ssh_packet_process_incoming(active_state, (buf), (len))
 #define packet_get_int64() \
         ssh_packet_get_int64(active_state)
 #define packet_get_bignum(value) \
diff --git a/packet.c b/packet.c
index 2c8d8aa9b..eb178f149 100644
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.203 2015/01/20 23:14:00 deraadt Exp $ */
+/* $OpenBSD: packet.c,v 1.204 2015/01/28 21:15:47 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1314,26 +1314,22 @@ ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
                                 break;
                         }
                 }
-                if (r == 0) {
-                        logit("Connection to %.200s timed out while "
-                            "waiting to read", ssh_remote_ipaddr(ssh));
-                        cleanup_exit(255);
-                }
+                if (r == 0)
+                        return SSH_ERR_CONN_TIMEOUT;
                 /* Read data from the socket. */
                 do {
                         cont = 0;
                         len = roaming_read(state->connection_in, buf,
                             sizeof(buf), &cont);
                 } while (len == 0 && cont);
-                if (len == 0) {
-                        logit("Connection closed by %.200s",
-                            ssh_remote_ipaddr(ssh));
-                        cleanup_exit(255);
-                }
+                if (len == 0)
+                        return SSH_ERR_CONN_CLOSED;
                 if (len < 0)
-                        fatal("Read from socket failed: %.100s", strerror(errno));
+                        return SSH_ERR_SYSTEM_ERROR;
+
                 /* Append it to the buffer. */
-                ssh_packet_process_incoming(ssh, buf, len);
+                if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
+                        return r;
         }
         free(setp);
         return r;
@@ -1787,7 +1783,7 @@ ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
  * together with packet_read_poll.
  */
 
-void
+int
 ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
 {
         struct session_state *state = ssh->state;
@@ -1797,14 +1793,15 @@ ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
                 state->keep_alive_timeouts = 0; /* ?? */
                 if (len >= state->packet_discard) {
                         if ((r = ssh_packet_stop_discard(ssh)) != 0)
-                                fatal("%s: %s", __func__, ssh_err(r));
-                        cleanup_exit(255);
+                                return r;
                 }
                 state->packet_discard -= len;
-                return;
+                return 0;
         }
         if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
-                fatal("%s: %s", __func__, ssh_err(r));
+                return r;
+
+        return 0;
 }
 
 int
diff --git a/packet.h b/packet.h
index 069af2eae..8a9d0f6c6 100644
--- a/packet.h
+++ b/packet.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.h,v 1.64 2015/01/19 20:30:23 markus Exp $ */
+/* $OpenBSD: packet.h,v 1.65 2015/01/28 21:15:47 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -94,7 +94,7 @@ void     ssh_packet_read_expect(struct ssh *, int type);
 int      ssh_packet_read_poll(struct ssh *);
 int ssh_packet_read_poll1(struct ssh *, u_char *);
 int ssh_packet_read_poll2(struct ssh *, u_char *, u_int32_t *seqnr_p);
-void     ssh_packet_process_incoming(struct ssh *, const char *buf, u_int len);
+int      ssh_packet_process_incoming(struct ssh *, const char *buf, u_int len);
 int      ssh_packet_read_seqnr(struct ssh *, u_char *, u_int32_t *seqnr_p);
 int      ssh_packet_read_poll_seqnr(struct ssh *, u_char *, u_int32_t *seqnr_p);
 
diff --git a/ssh-keyscan.c b/ssh-keyscan.c
index 25a257cc2..e59eacace 100644
--- a/ssh-keyscan.c
+++ b/ssh-keyscan.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keyscan.c,v 1.96 2015/01/20 23:14:00 deraadt Exp $ */
+/* $OpenBSD: ssh-keyscan.c,v 1.97 2015/01/28 21:15:47 djm Exp $ */
 /*
  * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
  *
@@ -319,8 +319,10 @@ tcpconnect(char *host)
         memset(&hints, 0, sizeof(hints));
         hints.ai_family = IPv4or6;
         hints.ai_socktype = SOCK_STREAM;
-        if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
-                fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
+        if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
+                error("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
+                return -1;
+        }
         for (ai = aitop; ai; ai = ai->ai_next) {
                 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                 if (s < 0) {
diff --git a/ssherr.c b/ssherr.c
index 49fbb71de..0b79fbb00 100644
--- a/ssherr.c
+++ b/ssherr.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ssherr.c,v 1.1 2014/04/30 05:29:56 djm Exp $  */
+/*      $OpenBSD: ssherr.c,v 1.2 2015/01/28 21:15:47 djm Exp $  */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -125,6 +125,10 @@ ssh_err(int n)
                 return "KRL file has invalid magic number";
         case SSH_ERR_KEY_REVOKED:
                 return "Key is revoked";
+        case SSH_ERR_CONN_CLOSED:
+                return "Connection closed";
+        case SSH_ERR_CONN_TIMEOUT:
+                return "Connection timed out";
         default:
                 return "unknown error";
         }
diff --git a/ssherr.h b/ssherr.h
index 106f786ea..ac5cd159a 100644
--- a/ssherr.h
+++ b/ssherr.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ssherr.h,v 1.1 2014/04/30 05:29:56 djm Exp $  */
+/*      $OpenBSD: ssherr.h,v 1.2 2015/01/28 21:15:47 djm Exp $  */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -73,6 +73,8 @@
 #define SSH_ERR_BUFFER_READ_ONLY                -49
 #define SSH_ERR_KRL_BAD_MAGIC                   -50
 #define SSH_ERR_KEY_REVOKED                     -51
+#define SSH_ERR_CONN_CLOSED                     -52
+#define SSH_ERR_CONN_TIMEOUT                    -53
 
 /* Translate a numeric error code to a human-readable error string */
 const char *ssh_err(int n);