use router address

[l2tpns.git] / icmp.c

diff --git a/icmp.c b/icmp.c
index f6c3e0d..da04c38 100644 (file)
--- a/icmp.c
+++ b/icmp.c
@@ -1,6 +1,6 @@
 // L2TPNS: icmp
 
-char const *cvs_id_icmp = "$Id: icmp.c,v 1.7 2005-01-25 04:19:05 bodea Exp $";
+char const *cvs_id_icmp = "$Id: icmp.c,v 1.8 2005-06-04 15:42:06 bodea Exp $";
 
 #include <arpa/inet.h>
 #include <netdb.h>
@@ -33,7 +33,6 @@ void host_unreachable(in_addr_t destination, uint16_t id, in_addr_t source, char
        char buf[128] = {0};
        struct iphdr *iph;
        struct icmphdr *icmp;
-       char *data;
        int len = 0, on = 1, icmp_socket;
        struct sockaddr_in whereto = {0};
 
@@ -49,9 +48,13 @@ void host_unreachable(in_addr_t destination, uint16_t id, in_addr_t source, char
        len = sizeof(struct iphdr);
        icmp = (struct icmphdr *)(buf + len);
        len += sizeof(struct icmphdr);
-       data = (char *)(buf + len);
-       len += (packet_len < 64) ? packet_len : 64;
-       memcpy(data, packet, (packet_len < 64) ? packet_len : 64);
+
+       /* ip header + first 8 bytes of payload */
+       if (packet_len > (sizeof(struct iphdr) + 8))
+               packet_len = sizeof(struct iphdr) + 8;
+
+       memcpy(buf + len, packet, packet_len);
+       len += packet_len;
 
        iph->tos = 0;
        iph->id = id;
@@ -69,7 +72,7 @@ void host_unreachable(in_addr_t destination, uint16_t id, in_addr_t source, char
 
        icmp->type = ICMP_DEST_UNREACH;
        icmp->code = ICMP_HOST_UNREACH;
-       icmp->checksum = _checksum((char *) icmp, sizeof(struct icmphdr) + ((packet_len < 64) ? packet_len : 64));
+       icmp->checksum = _checksum((char *) icmp, sizeof(struct icmphdr) + packet_len);
 
        iph->check = _checksum((char *) iph, sizeof(struct iphdr));