Update UDP csum field at runtime if:
1) UDP field was changed.
2) IPv4/6 source/destination addresses were changed
(which is a part of UDP pseudo header), this is
handled by IPv4/6 protocols.
Signed-off-by: Vadim Kochan <vadi...@gmail.com>
---
trafgen_l3.c | 18 ++++++++++++++++++
trafgen_l4.c | 37 +++++++++++++++++++++++++++++--------
2 files changed, 47 insertions(+), 8 deletions(-)
diff --git a/trafgen_l3.c b/trafgen_l3.c
index 9bb0de9..91052a0 100644
--- a/trafgen_l3.c
+++ b/trafgen_l3.c
@@ -46,6 +46,13 @@ static void ipv4_header_init(struct proto_hdr *hdr)
static void ipv4_field_changed(struct proto_field *field)
{
field->hdr->is_csum_valid = false;
+
+ if (field->id == IP4_SADDR || field->id == IP4_DADDR) {
+ struct proto_hdr *upper = proto_upper_header(field->hdr);
+
+ if (upper && upper->ops->id == PROTO_UDP)
+ upper->is_csum_valid = false;
+ }
}
static void ipv4_csum_update(struct proto_hdr *hdr)
@@ -136,6 +143,16 @@ static void ipv6_header_init(struct proto_hdr *hdr)
proto_field_set_default_dev_ipv6(hdr, IP6_SADDR);
}
+static void ipv6_field_changed(struct proto_field *field)
+{
+ if (field->id == IP6_SADDR || field->id == IP6_DADDR) {
+ struct proto_hdr *upper = proto_upper_header(field->hdr);
+
+ if (upper && upper->ops->id == PROTO_UDP)
+ upper->is_csum_valid = false;
+ }
+}
+
#define IPV6_HDR_LEN 40
static void ipv6_packet_finish(struct proto_hdr *hdr)
@@ -171,6 +188,7 @@ static const struct proto_ops ipv6_proto_ops = {
.id = PROTO_IP6,
.layer = PROTO_L3,
.header_init = ipv6_header_init,
+ .field_changed = ipv6_field_changed,
.packet_finish = ipv6_packet_finish,
.set_next_proto = ipv6_set_next_proto,
};
diff --git a/trafgen_l4.c b/trafgen_l4.c
index 7ec017e..ee8deb4 100644
--- a/trafgen_l4.c
+++ b/trafgen_l4.c
@@ -28,22 +28,29 @@ static void udp_header_init(struct proto_hdr *hdr)
proto_header_fields_add(hdr, udp_fields, array_size(udp_fields));
}
-static void udp_packet_finish(struct proto_hdr *hdr)
+static void udp_field_changed(struct proto_field *field)
{
- struct proto_hdr *lower = proto_lower_header(hdr);
- struct packet *pkt = current_packet();
+ field->hdr->is_csum_valid = false;
+}
+
+static void udp_csum_update(struct proto_hdr *hdr)
+{
+ struct proto_hdr *lower;
uint16_t total_len;
uint16_t csum;
- total_len = pkt->len - hdr->pkt_offset;
- proto_field_set_default_be16(hdr, UDP_LEN, total_len);
-
+ if (hdr->is_csum_valid)
+ return;
if (proto_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_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),
@@ -58,14 +65,28 @@ static void udp_packet_finish(struct proto_hdr *hdr)
break;
}
- proto_field_set_be16(hdr, UDP_CSUM, bswap_16(csum));
+ proto_field_set_default_be16(hdr, UDP_CSUM, bswap_16(csum));
+ hdr->is_csum_valid = true;
+}
+
+static void udp_packet_finish(struct proto_hdr *hdr)
+{
+ struct packet *pkt = current_packet();
+ uint16_t total_len;
+
+ total_len = pkt->len - hdr->pkt_offset;
+ proto_field_set_default_be16(hdr, UDP_LEN, total_len);
+
+ udp_csum_update(hdr);
}
static const struct proto_ops udp_proto_ops = {
.id = PROTO_UDP,
.layer = PROTO_L4,
.header_init = udp_header_init,
+ .packet_update = udp_csum_update,
.packet_finish = udp_packet_finish,
+ .field_changed = udp_field_changed,
};
static struct proto_field tcp_fields[] = {
--
2.9.2
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