[#71] Fix dhcrelay agent option buffer pointer logic

relay/dhcrelay.c
    Added UNIT_TEST conditionals and such for unit test support

    strip_relay_agent_options()
    strip_relay_agent_options()
    - corrected buffer pointer logic

relay/tests/Atffile
relay/tests/Kyuafile
relay/tests/Makefile.am
relay/tests/relay_unittests.c
    - new unit test files

configure.ac-base
    added relay/tests/Makefile

regenerated configure files
	configure
    configure.ac
    configure.ac+lt
    configure.ac-lt

1 files changed, 47 insertions, 25 deletions

diff --git a/relay/dhcrelay.c b/relay/dhcrelay.c
index 896e1e2e..980dacae 100644
--- a/relay/dhcrelay.c
+++ b/relay/dhcrelay.c
@@ -114,9 +114,11 @@ struct stream_list {
 	int id;
 } *downstreams, *upstreams;
 
+#ifndef UNIT_TEST
 static struct stream_list *parse_downstream(char *);
 static struct stream_list *parse_upstream(char *);
 static void setup_streams(void);
+#endif /* UNIT_TEST */
 
 /*
  * A pointer to a subscriber id to add to the message we forward.
@@ -127,18 +129,23 @@ static void setup_streams(void);
 char *dhcrelay_sub_id = NULL;
 #endif
 
+#ifndef UNIT_TEST
 static void do_relay4(struct interface_info *, struct dhcp_packet *,
 	              unsigned int, unsigned int, struct iaddr,
 		      struct hardware *);
-static int add_relay_agent_options(struct interface_info *,
-				   struct dhcp_packet *, unsigned,
-				   struct in_addr);
-static int find_interface_by_agent_option(struct dhcp_packet *,
-			       struct interface_info **, u_int8_t *, int);
-static int strip_relay_agent_options(struct interface_info *,
-				     struct interface_info **,
-				     struct dhcp_packet *, unsigned);
+#endif /* UNIT_TEST */
 
+extern int add_relay_agent_options(struct interface_info *,
+				            struct dhcp_packet *, unsigned,
+				            struct in_addr);
+extern int find_interface_by_agent_option(struct dhcp_packet *,
+			                       struct interface_info **, u_int8_t *, int);
+
+extern int strip_relay_agent_options(struct interface_info *,
+				              struct interface_info **,
+				              struct dhcp_packet *, unsigned);
+
+#ifndef UNIT_TEST
 static void request_v4_interface(const char* name, int flags);
 
 static const char copyright[] =
@@ -269,7 +276,7 @@ usage(const char *sfmt, const char *sarg) {
 		  isc_file_basename(progname));
 }
 
-int 
+int
 main(int argc, char **argv) {
 	isc_result_t status;
 	struct servent *ent;
@@ -310,7 +317,7 @@ main(int argc, char **argv) {
 
 #if !defined(DEBUG)
 	setlogmask(LOG_UPTO(LOG_INFO));
-#endif	
+#endif
 
 	/* Parse arguments changing no_daemon */
 	for (i = 1; i < argc; i++) {
@@ -524,7 +531,7 @@ main(int argc, char **argv) {
 				log_fatal("%s: uplink interface_allocate: %s",
 					 argv[i], isc_result_totext(status));
 			}
-		
+
 			if (strlen(argv[i]) >= sizeof(uplink->name)) {
 				log_fatal("%s: uplink name too long,"
 					  " it cannot exceed: %ld characters",
@@ -665,7 +672,7 @@ main(int argc, char **argv) {
 		log_info(copyright);
 		log_info(arr);
 		log_info(url);
-	} else 
+	} else
 		log_perror = 0;
 
 	/* Set default port */
@@ -789,7 +796,7 @@ main(int argc, char **argv) {
 				else {
 					fprintf(pf, "%ld\n",(long)getpid());
 					fclose(pf);
-				}	
+				}
 			}
 		}
 
@@ -968,14 +975,16 @@ do_relay4(struct interface_info *ip, struct dhcp_packet *packet,
 			++client_packets_relayed;
 		}
 	}
-				 
+
 }
 
+#endif /* UNIT_TEST */
+
 /* Strip any Relay Agent Information options from the DHCP packet
    option buffer.   If there is a circuit ID suboption, look up the
    outgoing interface based upon it. */
 
-static int
+int
 strip_relay_agent_options(struct interface_info *in,
 			  struct interface_info **out,
 			  struct dhcp_packet *packet,
@@ -1055,8 +1064,13 @@ strip_relay_agent_options(struct interface_info *in,
 				return (0);
 
 			if (sp != op) {
-				memmove(sp, op, op[1] + 2);
-				sp += op[1] + 2;
+				size_t mlen = op[1] + 2;
+				memmove(sp, op, mlen);
+				sp += mlen;
+				if (sp > max) {
+					return (0);
+				}
+
 				op = nextop;
 			} else
 				op = sp = nextop;
@@ -1107,7 +1121,7 @@ strip_relay_agent_options(struct interface_info *in,
    we find a circuit ID that matches an existing interface do we tell
    the caller to go ahead and process the packet. */
 
-static int
+int
 find_interface_by_agent_option(struct dhcp_packet *packet,
 			       struct interface_info **out,
 			       u_int8_t *buf, int len) {
@@ -1171,7 +1185,7 @@ find_interface_by_agent_option(struct dhcp_packet *packet,
  * Agent Information option tacked onto its tail.   If it is, tack
  * the option on.
  */
-static int
+int
 add_relay_agent_options(struct interface_info *ip, struct dhcp_packet *packet,
 			unsigned length, struct in_addr giaddr) {
 	int is_dhcp = 0, mms;
@@ -1284,8 +1298,13 @@ add_relay_agent_options(struct interface_info *ip, struct dhcp_packet *packet,
 			end_pad = NULL;
 
 			if (sp != op) {
-				memmove(sp, op, op[1] + 2);
-				sp += op[1] + 2;
+				size_t mlen = op[1] + 2;
+				memmove(sp, op, mlen);
+				sp += mlen;
+				if (sp > max) {
+					return (0);
+				}
+
 				op = nextop;
 			} else
 				op = sp = nextop;
@@ -1414,6 +1433,8 @@ add_relay_agent_options(struct interface_info *ip, struct dhcp_packet *packet,
 	return (length);
 }
 
+#ifndef UNIT_TEST
+
 #ifdef DHCPv6
 /*
  * Parse a downstream argument: [address%]interface[#index].
@@ -1726,7 +1747,7 @@ process_up6(struct packet *packet, struct stream_list *dp) {
 	if (!option_state_allocate(&opts, MDL)) {
 		log_fatal("No memory for upwards options.");
 	}
-	
+
 	/* Add an interface-id (if used). */
 	if (use_if_id) {
 		int if_id;
@@ -1763,7 +1784,7 @@ process_up6(struct packet *packet, struct stream_list *dp) {
 			return;
 		}
 	}
-		
+
 
 #if defined(RELAY_PORT)
 	/*
@@ -1802,7 +1823,7 @@ process_up6(struct packet *packet, struct stream_list *dp) {
 	/* Finish the relay-forward message. */
 	cursor += store_options6(forw_data + cursor,
 				 sizeof(forw_data) - cursor,
-				 opts, packet, 
+				 opts, packet,
 				 required_forw_opts, NULL);
 	option_state_dereference(&opts, MDL);
 
@@ -1812,7 +1833,7 @@ process_up6(struct packet *packet, struct stream_list *dp) {
 			     (size_t) cursor, &up->link);
 	}
 }
-			     
+
 /*
  * Process a packet downwards, i.e., from server to client.
  */
@@ -2126,3 +2147,4 @@ void request_v4_interface(const char* name, int flags) {
         interface_snorf(tmp, (INTERFACE_REQUESTED | flags));
         interface_dereference(&tmp, MDL);
 }
+#endif /* UNIT_TEST */