bpf: Permit ingress_ifindex in bpf_prog_test_run_xattr

bpf_prog_test_run_xattr takes a struct __sk_buff, but did not permit
that __skbuff to include an nonzero ingress_ifindex.

This patch updates to allow ingress_ifindex, convert the __sk_buff field to
sk_buff (skb_iif) and back, and tests that the value is present from on BPF
program side. The test sets an unlikely distinct value for ingress_ifindex
(11) from ifindex (1), which is in line with the rest of the synthetic field
tests.

Adding this support allows testing BPF that operates differently on
incoming and outgoing skbs by discriminating on this field.

Signed-off-by: Neil Spring <ntspring@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210831033356.1459316-1-ntspring@fb.com
This commit is contained in:
Neil Spring 2021-08-30 20:33:56 -07:00 committed by Andrii Nakryiko
parent 27151f1778
commit b238290b96
3 changed files with 12 additions and 5 deletions

View file

@ -483,11 +483,7 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
return -EINVAL;
/* priority is allowed */
if (!range_is_zero(__skb, offsetofend(struct __sk_buff, priority),
offsetof(struct __sk_buff, ifindex)))
return -EINVAL;
/* ingress_ifindex is allowed */
/* ifindex is allowed */
if (!range_is_zero(__skb, offsetofend(struct __sk_buff, ifindex),
@ -516,6 +512,7 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
skb->mark = __skb->mark;
skb->priority = __skb->priority;
skb->skb_iif = __skb->ingress_ifindex;
skb->tstamp = __skb->tstamp;
memcpy(&cb->data, __skb->cb, QDISC_CB_PRIV_LEN);
@ -545,6 +542,7 @@ static void convert_skb_to___skb(struct sk_buff *skb, struct __sk_buff *__skb)
__skb->mark = skb->mark;
__skb->priority = skb->priority;
__skb->ingress_ifindex = skb->skb_iif;
__skb->ifindex = skb->dev->ifindex;
__skb->tstamp = skb->tstamp;
memcpy(__skb->cb, &cb->data, QDISC_CB_PRIV_LEN);

View file

@ -11,6 +11,7 @@ void test_skb_ctx(void)
.cb[3] = 4,
.cb[4] = 5,
.priority = 6,
.ingress_ifindex = 11,
.ifindex = 1,
.tstamp = 7,
.wire_len = 100,
@ -97,6 +98,10 @@ void test_skb_ctx(void)
"ctx_out_ifindex",
"skb->ifindex == %d, expected %d\n",
skb.ifindex, 1);
CHECK_ATTR(skb.ingress_ifindex != 11,
"ctx_out_ingress_ifindex",
"skb->ingress_ifindex == %d, expected %d\n",
skb.ingress_ifindex, 11);
CHECK_ATTR(skb.tstamp != 8,
"ctx_out_tstamp",
"skb->tstamp == %lld, expected %d\n",

View file

@ -25,6 +25,10 @@ int process(struct __sk_buff *skb)
return 1;
if (skb->gso_size != 10)
return 1;
if (skb->ingress_ifindex != 11)
return 1;
if (skb->ifindex != 1)
return 1;
return 0;
}