From a51e573de1800142f3573b3c973879ee351f1a3d Mon Sep 17 00:00:00 2001 From: bodea Date: Sat, 4 Jun 2005 15:42:06 +0000 Subject: [PATCH 1/1] use router address --- icmp.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/icmp.c b/icmp.c index e0913ab..aefd768 100644 --- 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 #include @@ -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)); -- 2.20.1