Rev 351: paranoid checks for bad packets in tcp layer. Close the socket if it gets a bad packet in http://samba.org/~tridge/ctdb

[tridge at samba.org]

------------------------------------------------------------
revno: 351
revision-id: tridge at samba.org-20070526063232-f11jm7mw39jlmq8o
parent: tridge at samba.org-20070526044612-v0alyob7oxnvdun3
committer: Andrew Tridgell <tridge at samba.org>
branch nick: tridge
timestamp: Sat 2007-05-26 16:32:32 +1000
message:
  paranoid checks for bad packets in tcp layer. Close the socket if it gets a bad packet
modified:
  common/ctdb.c                  ctdb.c-20061127094323-t50f58d65iaao5of-2
  tcp/tcp_io.c                   tcp_io.c-20061128004937-x70q1cu5xzg5g2tm-3
=== modified file 'common/ctdb.c'
--- a/common/ctdb.c	2007-05-25 07:04:13 +0000
+++ b/common/ctdb.c	2007-05-26 06:32:32 +0000
@@ -347,26 +347,6 @@
 
 	ctdb->status.node_packets_recv++;
 
-	if (length < sizeof(*hdr)) {
-		ctdb_set_error(ctdb, "Bad packet length %u\n", length);
-		return;
-	}
-	if (length != hdr->length) {
-		ctdb_set_error(ctdb, "Bad header length %u expected %u\n", 
-			       hdr->length, length);
-		return;
-	}
-
-	if (hdr->ctdb_magic != CTDB_MAGIC) {
-		ctdb_set_error(ctdb, "Non CTDB packet rejected\n");
-		return;
-	}
-
-	if (hdr->ctdb_version != CTDB_VERSION) {
-		ctdb_set_error(ctdb, "Bad CTDB version 0x%x rejected\n", hdr->ctdb_version);
-		return;
-	}
-
 	/* up the counter for this source node, so we know its alive */
 	if (ctdb_validate_vnn(ctdb, hdr->srcnode)) {
 		/* as a special case, redirected calls don't increment the rx_cnt */

=== modified file 'tcp/tcp_io.c'
--- a/tcp/tcp_io.c	2007-04-28 09:35:49 +0000
+++ b/tcp/tcp_io.c	2007-05-26 06:32:32 +0000
@@ -34,38 +34,48 @@
 void ctdb_tcp_read_cb(uint8_t *data, size_t cnt, void *args)
 {
 	struct ctdb_incoming *in = talloc_get_type(args, struct ctdb_incoming);
-	struct ctdb_req_header *hdr;
+	struct ctdb_req_header *hdr = (struct ctdb_req_header *)data;
 
 	if (data == NULL) {
 		/* incoming socket has died */
-		talloc_free(in);
-		return;
+		goto failed;
 	}
 
 	if (cnt < sizeof(*hdr)) {
-		ctdb_set_error(in->ctdb, "Bad packet length %u\n", (unsigned)cnt);
-		return;
-	}
-	hdr = (struct ctdb_req_header *)data;
+		DEBUG(0,(__location__ " Bad packet length %u\n", (unsigned)cnt));
+		goto failed;
+	}
+
+	if (cnt & (CTDB_TCP_ALIGNMENT-1)) {
+		DEBUG(0,(__location__ " Length 0x%x not multiple of alignment\n", cnt));
+		goto failed;
+	}
+
+
 	if (cnt != hdr->length) {
-		ctdb_set_error(in->ctdb, "Bad header length %u expected %u\n", 
-			       (unsigned)hdr->length, (unsigned)cnt);
-		return;
+		DEBUG(0,(__location__ " Bad header length %u expected %u\n", 
+			 (unsigned)hdr->length, (unsigned)cnt));
+		goto failed;
 	}
 
 	if (hdr->ctdb_magic != CTDB_MAGIC) {
-		ctdb_set_error(in->ctdb, "Non CTDB packet rejected\n");
-		return;
+		DEBUG(0,(__location__ " Non CTDB packet 0x%x rejected\n", 
+			 hdr->ctdb_magic));
+		goto failed;
 	}
 
 	if (hdr->ctdb_version != CTDB_VERSION) {
-		ctdb_set_error(in->ctdb, "Bad CTDB version 0x%x rejected\n", hdr->ctdb_version);
-		return;
+		DEBUG(0, (__location__ " Bad CTDB version 0x%x rejected\n", 
+			  hdr->ctdb_version));
+		goto failed;
 	}
 
-	/* most common case - we got a whole packet in one go
-	   tell the ctdb layer above that we have a packet */
+	/* tell the ctdb layer above that we have a packet */
 	in->ctdb->upcalls->recv_pkt(in->ctdb, data, cnt);
+	return;
+
+failed:
+	talloc_free(in);
 }
 
 /*