On 11/14, Alexis Lothoré (eBPF Foundation) wrote:
network_helpers.c provides some helpers to generate ip checksums or ip pseudo-header checksums, but not for upper layers (eg: udp checksums)
Add helpers for udp checksum to allow manually building udp packets.
Signed-off-by: Alexis Lothoré (eBPF Foundation) alexis.lothore@bootlin.com
Changes in v2:
- new patch
tools/testing/selftests/bpf/network_helpers.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h index 6d1ae56080c56a65c437899c32566f0e4c496c33..fa82269f7a169a518ba210fa8641eba02f262333 100644 --- a/tools/testing/selftests/bpf/network_helpers.h +++ b/tools/testing/selftests/bpf/network_helpers.h @@ -161,6 +161,33 @@ build_ipv6_pseudo_header_csum(const struct in6_addr *saddr, return csum_fold((__u32)s); } +static inline __sum16 build_udp_v4_csum(const struct iphdr *iph, __u8 l4_proto,
__u16 l4_len, const void *l4_start,int num_words)+{
- unsigned long pseudo_sum;
- int num_u16 = sizeof(iph->saddr); /* halfwords: twice byte len */
- pseudo_sum = add_csum_hword((void *)&iph->saddr, num_u16);
- pseudo_sum += htons(l4_proto);
- pseudo_sum += l4_len;
- pseudo_sum += add_csum_hword(l4_start, num_words);
- return csum_fold(pseudo_sum);
I was expecting to see a call to csum_tcpudp_magic here. And csum_ipv6_magic down below. These build pseudo header csum, so no need to manually do it again.
+}
+static inline __sum16 build_udp_v6_csum(const struct ipv6hdr *ip6h,
const void *l4_start, int num_words)+{
- unsigned long pseudo_sum;
- int num_u16 = sizeof(ip6h->saddr); /* halfwords: twice byte len */
- pseudo_sum = add_csum_hword((void *)&ip6h->saddr, num_u16);
- pseudo_sum += htons(ip6h->nexthdr);
- pseudo_sum += ip6h->payload_len;
- pseudo_sum += add_csum_hword(l4_start, num_words);
- return csum_fold(pseudo_sum);
+}
struct tmonitor_ctx; #ifdef TRAFFIC_MONITOR
-- 2.47.0