Update filter_udphdr to use bpf_dynptr_slice to read the packet headers
instead of accessing them directly.
The function previously returned a pointer to the UDP header, which
was then used to calculate Ethernet and IP header lengths by
subtracting xdp->data. Since this only works when the UDP header is in
the linear region, rework the function to return the total header
length instead of a pointer. Rename filter_udphdr() to check_udphdr()
to reflect the new behavior.
This makes the test viable for drivers that do not store any
packet data in the linear part when in multi-buffer mode.
Signed-off-by: Nimrod Oren <noren@xxxxxxxxxx>
Reviewed-by: Carolina Jubran <cjubran@xxxxxxxxxx>
Reviewed-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
---
.../selftests/net/lib/xdp_native.bpf.c | 80 +++++++------------
1 file changed, 31 insertions(+), 49 deletions(-)
diff --git a/tools/testing/selftests/net/lib/xdp_native.bpf.c b/tools/testing/selftests/net/lib/xdp_native.bpf.c
index ff63f572552b..6df5164e3791 100644
--- a/tools/testing/selftests/net/lib/xdp_native.bpf.c
+++ b/tools/testing/selftests/net/lib/xdp_native.bpf.c
@@ -63,53 +63,49 @@ static void record_stats(struct xdp_md *ctx, __u32 stat_type)
__sync_fetch_and_add(count, 1);
}
-static struct udphdr *filter_udphdr(struct xdp_md *ctx, __u16 port)
+static __u32 check_udphdr(struct xdp_md *ctx, __u16 port)
{
- void *data_end = (void *)(long)ctx->data_end;
- void *data = (void *)(long)ctx->data;
struct udphdr *udph = NULL;
- struct ethhdr *eth = data;
+ struct ethhdr *eth = NULL;
+ struct bpf_dynptr ptr;
- if (data + sizeof(*eth) > data_end)
- return NULL;
+ bpf_dynptr_from_xdp(ctx, 0, &ptr);
+ eth = bpf_dynptr_slice(&ptr, 0, NULL, sizeof(*eth));
+ if (!eth)
+ return 0;
if (eth->h_proto == bpf_htons(ETH_P_IP)) {
- struct iphdr *iph = data + sizeof(*eth);
+ struct iphdr *iph = bpf_dynptr_slice(&ptr, sizeof(*eth),
+ NULL, sizeof(*iph));
- if (iph + 1 > (struct iphdr *)data_end ||
- iph->protocol != IPPROTO_UDP)
- return NULL;
+ if (!iph || iph->protocol != IPPROTO_UDP)
+ return 0;
- udph = (void *)eth + sizeof(*iph) + sizeof(*eth);
- } else if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
- struct ipv6hdr *ipv6h = data + sizeof(*eth);
+ udph = bpf_dynptr_slice(&ptr, sizeof(*iph) + sizeof(*eth),
+ NULL, sizeof(*udph));
+ } else if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
+ struct ipv6hdr *ipv6h = bpf_dynptr_slice(&ptr, sizeof(*eth),
+ NULL, sizeof(*ipv6h));
- if (ipv6h + 1 > (struct ipv6hdr *)data_end ||
- ipv6h->nexthdr != IPPROTO_UDP)
- return NULL;
+ if (!ipv6h || ipv6h->nexthdr != IPPROTO_UDP)
+ return 0;
- udph = (void *)eth + sizeof(*ipv6h) + sizeof(*eth);
+ udph = bpf_dynptr_slice(&ptr, sizeof(*ipv6h) + sizeof(*eth),
+ NULL, sizeof(*udph));
} else {
- return NULL;
+ return 0;
}
- if (udph + 1 > (struct udphdr *)data_end)
- return NULL;
-
- if (udph->dest != bpf_htons(port))
- return NULL;
+ if (!udph || udph->dest != bpf_htons(port))
+ return 0;
record_stats(ctx, STATS_RX);
-
- return udph;
+ return (void *)udph - (void *)eth + sizeof(*udph);
}
static int xdp_mode_pass(struct xdp_md *ctx, __u16 port)
{
- struct udphdr *udph = NULL;
-
- udph = filter_udphdr(ctx, port);
- if (!udph)
+ if (!check_udphdr(ctx, port))
return XDP_PASS;
record_stats(ctx, STATS_PASS);
@@ -119,10 +115,7 @@ static int xdp_mode_pass(struct xdp_md *ctx, __u16 port)
static int xdp_mode_drop_handler(struct xdp_md *ctx, __u16 port)
{
- struct udphdr *udph = NULL;
-
- udph = filter_udphdr(ctx, port);
- if (!udph)
+ if (!check_udphdr(ctx, port))
return XDP_PASS;
record_stats(ctx, STATS_DROP);
@@ -363,19 +356,14 @@ static int xdp_adjst_tail_grow_data(struct xdp_md *ctx, __u16 offset)
static int xdp_adjst_tail(struct xdp_md *ctx, __u16 port)
{
- void *data = (void *)(long)ctx->data;
- struct udphdr *udph = NULL;
- __s32 *adjust_offset, *val;
+ __s32 *adjust_offset;
__u32 key, hdr_len;
- void *offset_ptr;
- __u8 tag;
int ret;
- udph = filter_udphdr(ctx, port);
- if (!udph)
+ hdr_len = check_udphdr(ctx, port);
+ if (!hdr_len)
return XDP_PASS;
- hdr_len = (void *)udph - data + sizeof(struct udphdr);
key = XDP_ADJST_OFFSET;
adjust_offset = bpf_map_lookup_elem(&map_xdp_setup, &key);
if (!adjust_offset)
@@ -504,20 +492,14 @@ static int xdp_adjst_head_grow_data(struct xdp_md *ctx, __u64 hdr_len,
static int xdp_head_adjst(struct xdp_md *ctx, __u16 port)
{
- void *data_end = (void *)(long)ctx->data_end;
- void *data = (void *)(long)ctx->data;
- struct udphdr *udph_ptr = NULL;
__u32 key, size, hdr_len;
__s32 *val;
int res;
- /* Filter packets based on UDP port */
- udph_ptr = filter_udphdr(ctx, port);
- if (!udph_ptr)
+ hdr_len = check_udphdr(ctx, port);
+ if (!hdr_len)
return XDP_PASS;
- hdr_len = (void *)udph_ptr - data + sizeof(struct udphdr);
-
key = XDP_ADJST_OFFSET;
val = bpf_map_lookup_elem(&map_xdp_setup, &key);
if (!val)
--
2.45.0
