X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/cfd794827e3243c681590845063309fa628cfef4..211cd6277e10a6402a4f7abb41dc8b0829b04ada:/netlink.c

diff --git a/netlink.c b/netlink.c
index 87b6671..0dd4450 100644
--- a/netlink.c
+++ b/netlink.c
@@ -120,7 +120,7 @@ their use.
 #define ICMP_CODE_TTL_EXCEEDED           0
 
 /* Generic IP checksum routine */
-static inline uint16_t ip_csum(uint8_t *iph,int32_t count)
+static inline uint16_t ip_csum(const uint8_t *iph,int32_t count)
 {
     register uint32_t sum=0;
 
@@ -144,7 +144,7 @@ static inline uint16_t ip_csum(uint8_t *iph,int32_t count)
  *      By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
  *      Arnt Gulbrandsen.
  */
-static inline uint16_t ip_fast_csum(uint8_t *iph, int32_t ihl) {
+static inline uint16_t ip_fast_csum(const uint8_t *iph, int32_t ihl) {
     uint32_t sum;
 
     __asm__ __volatile__(
@@ -304,9 +304,17 @@ static bool_t netlink_icmp_may_reply(struct buffer_if *buf)
     icmph=(struct icmphdr *)buf->start;
     if (iph->protocol==1) {
 	switch(icmph->type) {
-	case 3: /* Destination unreachable */
-	case 11: /* Time Exceeded */
-	case 12: /* Parameter Problem */
+	    /* Based on http://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml#icmp-parameters-types
+	     * as retrieved Thu, 20 Mar 2014 00:16:44 +0000.
+	     * Deprecated, reserved, unassigned and experimental
+	     * options are treated as not safe to reply to.
+	     */
+	case 0: /* Echo Reply */
+	case 8: /* Echo */
+	case 13: /* Timestamp */
+	case 14: /* Timestamp Reply */
+	    return True;
+	default:
 	    return False;
 	}
     }