svn commit: r229000 - head/sbin/dhclient

[Jean-Sebastien Pedron]

Author: dumbbell
Date: Fri Dec 30 14:33:08 2011
New Revision: 229000
URL: http://svn.freebsd.org/changeset/base/229000

Log:
  Invalid Domain Search option isn't considered as a fatal error
  
  In the original Domain Search option patch, an invalid option value
  would cause the whole lease to be rejected. However, DHCP servers who
  emit such an invalid value are more common than I thought. With this new
  patch, just the option is rejected, not the entire lease.
  
  PR:		bin/163431
  Submitted by:	Fabian Keil <fk at fabiankeil.de> (earlier version)
  Reviewed by:	Fabian Keil <fk at fabiankeil.de>
  Sponsored by:	Yakaz (http://www.yakaz.com)

Modified:
  head/sbin/dhclient/options.c

Modified: head/sbin/dhclient/options.c
==============================================================================
--- head/sbin/dhclient/options.c	Fri Dec 30 14:30:16 2011	(r228999)
+++ head/sbin/dhclient/options.c	Fri Dec 30 14:33:08 2011	(r229000)
@@ -211,7 +211,7 @@ parse_option_buffer(struct packet *packe
 void
 expand_domain_search(struct packet *packet)
 {
-	int offset, expanded_len;
+	int offset, expanded_len, next_domain_len;
 	struct option_data *option;
 	unsigned char *domain_search, *cursor;
 
@@ -224,9 +224,13 @@ expand_domain_search(struct packet *pack
 	expanded_len = 0;
 	offset = 0;
 	while (offset < option->len) {
+		next_domain_len = find_search_domain_name_len(option, &offset);
+		if (next_domain_len < 0)
+			/* The Domain Search option value is invalid. */
+			return;
+
 		/* We add 1 for the space between domain names. */
-		expanded_len +=
-		    find_search_domain_name_len(option, &offset) + 1;
+		expanded_len += next_domain_len + 1;
 	}
 	if (expanded_len > 0)
 		/* Remove 1 for the superfluous trailing space. */
@@ -271,8 +275,9 @@ find_search_domain_name_len(struct optio
 			/* This is a pointer to another list of labels. */
 			if (i + 1 >= option->len) {
 				/* The pointer is truncated. */
-				error("Truncated pointer in DHCP Domain "
+				warning("Truncated pointer in DHCP Domain "
 				    "Search option.");
+				return (-1);
 			}
 
 			pointer = ((label_len & ~(0xC0)) << 8) +
@@ -282,8 +287,9 @@ find_search_domain_name_len(struct optio
 				 * The pointer must indicates a prior
 				 * occurance.
 				 */
-				error("Invalid forward pointer in DHCP Domain "
-				    "Search option compression.");
+				warning("Invalid forward pointer in DHCP "
+				    "Domain Search option compression.");
+				return (-1);
 			}
 
 			pointed_len = find_search_domain_name_len(option,
@@ -295,7 +301,9 @@ find_search_domain_name_len(struct optio
 		}
 
 		if (i + label_len >= option->len) {
-			error("Truncated label in DHCP Domain Search option.");
+			warning("Truncated label in DHCP Domain Search "
+			    "option.");
+			return (-1);
 		}
 
 		/*
@@ -308,9 +316,9 @@ find_search_domain_name_len(struct optio
 		i += label_len + 1;
 	}
 
-	error("Truncated DHCP Domain Search option.");
+	warning("Truncated DHCP Domain Search option.");
 
-	return (0);
+	return (-1);
 }
 
 void