diff options
Diffstat (limited to 'trafgen_l4.c')
| -rw-r--r-- | trafgen_l4.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/trafgen_l4.c b/trafgen_l4.c index ee8deb4..b3b0775 100644 --- a/trafgen_l4.c +++ b/trafgen_l4.c @@ -118,13 +118,20 @@ static void tcp_header_init(struct proto_hdr *hdr) proto_field_set_default_be16(hdr, TCP_DOFF, 5); } -static void tcp_packet_finish(struct proto_hdr *hdr) +static void tcp_field_changed(struct proto_field *field) +{ + field->hdr->is_csum_valid = false; +} + +static void tcp_csum_update(struct proto_hdr *hdr) { struct proto_hdr *lower = proto_lower_header(hdr); struct packet *pkt = current_packet(); uint16_t total_len; uint16_t csum; + if (hdr->is_csum_valid) + return; if (proto_field_is_set(hdr, TCP_CSUM)) return; @@ -133,6 +140,8 @@ static void tcp_packet_finish(struct proto_hdr *hdr) total_len = pkt->len - hdr->pkt_offset; + proto_field_set_default_be16(hdr, TCP_CSUM, 0); + switch (lower->ops->id) { case PROTO_IP4: csum = p4_csum((void *) proto_header_ptr(lower), proto_header_ptr(hdr), @@ -147,14 +156,17 @@ static void tcp_packet_finish(struct proto_hdr *hdr) break; } - proto_field_set_be16(hdr, TCP_CSUM, bswap_16(csum)); + proto_field_set_default_be16(hdr, TCP_CSUM, bswap_16(csum)); + hdr->is_csum_valid = true; } static const struct proto_ops tcp_proto_ops = { .id = PROTO_TCP, .layer = PROTO_L4, .header_init = tcp_header_init, - .packet_finish = tcp_packet_finish, + .packet_update = tcp_csum_update, + .packet_finish = tcp_csum_update, + .field_changed = tcp_field_changed, }; static struct proto_field icmpv4_fields[] = { |