xdp_metadata test has a small helper computing ipv4 checksums to allow
manually building packets.
Move this helper to network_helpers to share it with other tests.
Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
---
Changes in v3:
- use csum_partial for intermediate helper name to keep sync with the
corresponding kernel helper
- provide byte count instead of half-word count to csum_partial
Changes in v2:
- new patch
---
tools/testing/selftests/bpf/network_helpers.h | 24 ++++++++++++++++++++++
.../selftests/bpf/prog_tests/xdp_metadata.c | 19 +----------------
2 files changed, 25 insertions(+), 18 deletions(-)
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index c72c16e1aff825439896b38e59962ffafe92dc71..5ef909f766eb9ac2dd5be67b99245b4676ce4f5f 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -104,6 +104,30 @@ static __u16 csum_fold(__u32 csum)
return (__u16)~csum;
}
+static __wsum csum_partial(const void *buf, int len, __wsum sum)
+{
+ __u16 *p = (__u16 *)buf;
+ int num_u16 = len >> 1;
+ int i;
+
+ for (i = 0; i < num_u16; i++)
+ sum += p[i];
+
+ return sum;
+}
+
+static inline __sum16 build_ip_csum(struct iphdr *iph)
+{
+ __u32 sum = 0;
+ __u16 *p;
+
+ iph->check = 0;
+ p = (void *)iph;
+ sum = csum_partial(p, iph->ihl << 2, 0);
+
+ return csum_fold(sum);
+}
+
static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum csum)
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
index c87ee2bf558c1a7fb726cae0aa7b3d3735fb1aac..7f8e161655336127e5bd7a573d1a09db85a92f53 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
@@ -133,23 +133,6 @@ static void close_xsk(struct xsk *xsk)
munmap(xsk->umem_area, UMEM_SIZE);
}
-static void ip_csum(struct iphdr *iph)
-{
- __u32 sum = 0;
- __u16 *p;
- int i;
-
- iph->check = 0;
- p = (void *)iph;
- for (i = 0; i < sizeof(*iph) / sizeof(*p); i++)
- sum += p[i];
-
- while (sum >> 16)
- sum = (sum & 0xffff) + (sum >> 16);
-
- iph->check = ~sum;
-}
-
static int generate_packet(struct xsk *xsk, __u16 dst_port)
{
struct xsk_tx_metadata *meta;
@@ -192,7 +175,7 @@ static int generate_packet(struct xsk *xsk, __u16 dst_port)
iph->protocol = IPPROTO_UDP;
ASSERT_EQ(inet_pton(FAMILY, TX_ADDR, &iph->saddr), 1, "inet_pton(TX_ADDR)");
ASSERT_EQ(inet_pton(FAMILY, RX_ADDR, &iph->daddr), 1, "inet_pton(RX_ADDR)");
- ip_csum(iph);
+ iph->check = build_ip_csum(iph);
udph->source = htons(UDP_SOURCE_PORT);
udph->dest = htons(dst_port);
--
2.47.0