add compile-time check for correct DHCP packet size

This commit is contained in:
Denis Vlasenko 2006-11-20 01:13:09 +00:00
parent 4a5cf16a36
commit c9cdeaa3fe

View File

@ -109,6 +109,7 @@ uint16_t udhcp_checksum(void *addr, int count)
/* Construct a ip/udp header for a packet, and specify the source and dest hardware address */ /* Construct a ip/udp header for a packet, and specify the source and dest hardware address */
void BUG_sizeof_struct_udp_dhcp_packet_must_be_576(void);
int udhcp_raw_packet(struct dhcpMessage *payload, int udhcp_raw_packet(struct dhcpMessage *payload,
uint32_t source_ip, int source_port, uint32_t source_ip, int source_port,
uint32_t dest_ip, int dest_port, uint8_t *dest_arp, int ifindex) uint32_t dest_ip, int dest_port, uint8_t *dest_arp, int ifindex)
@ -154,6 +155,9 @@ int udhcp_raw_packet(struct dhcpMessage *payload,
packet.ip.ttl = IPDEFTTL; packet.ip.ttl = IPDEFTTL;
packet.ip.check = udhcp_checksum(&(packet.ip), sizeof(packet.ip)); packet.ip.check = udhcp_checksum(&(packet.ip), sizeof(packet.ip));
if (sizeof(struct udp_dhcp_packet) != 576)
BUG_sizeof_struct_udp_dhcp_packet_must_be_576();
result = sendto(fd, &packet, sizeof(struct udp_dhcp_packet), 0, result = sendto(fd, &packet, sizeof(struct udp_dhcp_packet), 0,
(struct sockaddr *) &dest, sizeof(dest)); (struct sockaddr *) &dest, sizeof(dest));
if (result <= 0) { if (result <= 0) {