static void apply_csum16(int csum_id)
{
int j, i = csum_id;
size_t csum_max = packet_dyn[i].slen;
for (j = 0; j < csum_max; ++j) {
uint16_t sum = 0;
struct csum16 *csum = &packet_dyn[i].csum[j];
fmemset(&packets[i].payload[csum->off], 0, sizeof(sum));
switch (csum->which) {
case CSUM_IP:
if (csum->to >= packets[i].len)
csum->to = packets[i].len - 1;
sum = calc_csum(packets[i].payload + csum->from,
csum->to - csum->from + 1, 0);
break;
case CSUM_UDP:
sum = p4_csum((void *) packets[i].payload + csum->from,
packets[i].payload + csum->to,
(packets[i].len - csum->to),
IPPROTO_UDP);
break;
case CSUM_TCP:
sum = p4_csum((void *) packets[i].payload + csum->from,
packets[i].payload + csum->to,
(packets[i].len - csum->to),
IPPROTO_TCP);
break;
}
fmemcpy(&packets[i].payload[csum->off], &sum, sizeof(sum));
}
}
static void udp_csum_update(struct proto_hdr *hdr)
{
struct proto_hdr *lower;
uint16_t total_len;
uint16_t csum;
if (hdr->is_csum_valid)
return;
if (proto_hdr_field_is_set(hdr, UDP_CSUM))
return;
lower = proto_lower_header(hdr);
if (!lower)
return;
total_len = packet_get(hdr->pkt_id)->len - hdr->pkt_offset;
proto_hdr_field_set_default_be16(hdr, UDP_CSUM, 0);
switch (lower->ops->id) {
case PROTO_IP4:
csum = p4_csum((void *) proto_header_ptr(lower), proto_header_ptr(hdr),
total_len, IPPROTO_UDP);
break;
case PROTO_IP6:
csum = p6_csum((void *) proto_header_ptr(lower), proto_header_ptr(hdr),
total_len, IPPROTO_UDP);
break;
default:
csum = 0;
break;
}
proto_hdr_field_set_default_be16(hdr, UDP_CSUM, bswap_16(csum));
hdr->is_csum_valid = true;
}
