On Mon, Dec 11, 2023 at 3:49 PM Daniel Xu dxu@dxuuu.xyz wrote:
On Mon, Dec 11, 2023 at 03:13:07PM -0800, Eyal Birger wrote:
On Mon, Dec 11, 2023 at 2:31 PM Daniel Xu dxu@dxuuu.xyz wrote:
On Mon, Dec 11, 2023 at 01:39:25PM -0800, Eyal Birger wrote:
Hi Daniel,
Tiny nits below in case you respin this for other reasons:
On Mon, Dec 11, 2023 at 12:20 PM Daniel Xu dxu@dxuuu.xyz wrote:
This commit extends test_tunnel selftest to test the new XDP xfrm state lookup kfunc.
Co-developed-by: Antony Antony antony.antony@secunet.com Signed-off-by: Antony Antony antony.antony@secunet.com Signed-off-by: Daniel Xu dxu@dxuuu.xyz
.../selftests/bpf/prog_tests/test_tunnel.c | 20 ++++++-- .../selftests/bpf/progs/test_tunnel_kern.c | 51 +++++++++++++++++++ 2 files changed, 67 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/test_tunnel.c b/tools/testing/selftests/bpf/prog_tests/test_tunnel.c index 2d7f8fa82ebd..fc804095d578 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_tunnel.c +++ b/tools/testing/selftests/bpf/prog_tests/test_tunnel.c @@ -278,7 +278,7 @@ static int add_xfrm_tunnel(void) SYS(fail, "ip netns exec at_ns0 " "ip xfrm state add src %s dst %s proto esp "
"spi %d reqid 1 mode tunnel "
"spi %d reqid 1 mode tunnel replay-window 42 " "auth-trunc 'hmac(sha1)' %s 96 enc 'cbc(aes)' %s", IP4_ADDR_VETH0, IP4_ADDR1_VETH1, XFRM_SPI_IN_TO_OUT, XFRM_AUTH, XFRM_ENC); SYS(fail,@@ -292,7 +292,7 @@ static int add_xfrm_tunnel(void) SYS(fail, "ip netns exec at_ns0 " "ip xfrm state add src %s dst %s proto esp "
"spi %d reqid 2 mode tunnel "
"spi %d reqid 2 mode tunnel replay-window 42 "nit: why do you need to set the replay-window in both directions?
No reason - probably just careless here.
"auth-trunc 'hmac(sha1)' %s 96 enc 'cbc(aes)' %s", IP4_ADDR1_VETH1, IP4_ADDR_VETH0, XFRM_SPI_OUT_TO_IN, XFRM_AUTH, XFRM_ENC); SYS(fail,@@ -313,7 +313,7 @@ static int add_xfrm_tunnel(void) */ SYS(fail, "ip xfrm state add src %s dst %s proto esp "
"spi %d reqid 1 mode tunnel "
"spi %d reqid 1 mode tunnel replay-window 42 " "auth-trunc 'hmac(sha1)' %s 96 enc 'cbc(aes)' %s", IP4_ADDR_VETH0, IP4_ADDR1_VETH1, XFRM_SPI_IN_TO_OUT, XFRM_AUTH, XFRM_ENC); SYS(fail,@@ -325,7 +325,7 @@ static int add_xfrm_tunnel(void) /* root -> at_ns0 */ SYS(fail, "ip xfrm state add src %s dst %s proto esp "
"spi %d reqid 2 mode tunnel "
"spi %d reqid 2 mode tunnel replay-window 42 " "auth-trunc 'hmac(sha1)' %s 96 enc 'cbc(aes)' %s", IP4_ADDR1_VETH1, IP4_ADDR_VETH0, XFRM_SPI_OUT_TO_IN, XFRM_AUTH, XFRM_ENC); SYS(fail,@@ -628,8 +628,10 @@ static void test_xfrm_tunnel(void) { DECLARE_LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);
LIBBPF_OPTS(bpf_xdp_attach_opts, opts); struct test_tunnel_kern *skel = NULL; struct nstoken *nstoken;int xdp_prog_fd; int tc_prog_fd; int ifindex; int err;@@ -654,6 +656,14 @@ static void test_xfrm_tunnel(void) if (attach_tc_prog(&tc_hook, tc_prog_fd, -1)) goto done;
/* attach xdp prog to tunnel dev */xdp_prog_fd = bpf_program__fd(skel->progs.xfrm_get_state_xdp);if (!ASSERT_GE(xdp_prog_fd, 0, "bpf_program__fd"))goto done;err = bpf_xdp_attach(ifindex, xdp_prog_fd, XDP_FLAGS_REPLACE, &opts);if (!ASSERT_OK(err, "bpf_xdp_attach"))goto done;/* ping from at_ns0 namespace test */ nstoken = open_netns("at_ns0"); err = test_ping(AF_INET, IP4_ADDR_TUNL_DEV1);@@ -667,6 +677,8 @@ static void test_xfrm_tunnel(void) goto done; if (!ASSERT_EQ(skel->bss->xfrm_remote_ip, 0xac100164, "remote_ip")) goto done;
if (!ASSERT_EQ(skel->bss->xfrm_replay_window, 42, "replay_window"))goto done;done: delete_xfrm_tunnel(); diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c index 3a59eb9c34de..c0dd38616562 100644 --- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c +++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c @@ -30,6 +30,10 @@ int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __ksym; int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __ksym; +struct xfrm_state * +bpf_xdp_get_xfrm_state(struct xdp_md *ctx, struct bpf_xfrm_state_opts *opts,
u32 opts__sz) __ksym;+void bpf_xdp_xfrm_state_release(struct xfrm_state *x) __ksym;
struct { __uint(type, BPF_MAP_TYPE_ARRAY); @@ -950,4 +954,51 @@ int xfrm_get_state(struct __sk_buff *skb) return TC_ACT_OK; }
+volatile int xfrm_replay_window = 0;
+SEC("xdp") +int xfrm_get_state_xdp(struct xdp_md *xdp) +{
struct bpf_xfrm_state_opts opts = {};struct xfrm_state *x = NULL;struct ip_esp_hdr *esph;struct bpf_dynptr ptr;u8 esph_buf[8] = {};u8 iph_buf[20] = {};struct iphdr *iph;u32 off;if (bpf_dynptr_from_xdp(xdp, 0, &ptr))goto out;off = sizeof(struct ethhdr);iph = bpf_dynptr_slice(&ptr, off, iph_buf, sizeof(iph_buf));if (!iph || iph->protocol != IPPROTO_ESP)goto out;off += sizeof(struct iphdr);esph = bpf_dynptr_slice(&ptr, off, esph_buf, sizeof(esph_buf));if (!esph)goto out;opts.netns_id = BPF_F_CURRENT_NETNS;opts.daddr.a4 = iph->daddr;opts.spi = esph->spi;opts.proto = IPPROTO_ESP;opts.family = AF_INET;x = bpf_xdp_get_xfrm_state(xdp, &opts, sizeof(opts));if (!x || opts.error)nit: how can opts.error be non zero if x == NULL?
Ignoring the new -ENOENT case, it can't. Which is why I'm testing that behavior here.
I'm sorry, I don't understand.
AFAICT, regardless of the -ENOENT change, I don't see how (!x) is false and (opt.error) is true, and so "if (!x || opts.error)" is always equivalent to "if (!x)".
What am I missing? Eyal.
The selftests are tests so my intention was to check edge cases here. In normal operation it shouldn't be possible that bpf_xdp_get_xfrm_state() returns non-NULL and also an error. Maybe another way of writing this would be:
if (!x) goto out; assert(opts.error == 0);
I think this would convey the "edge case testing" notion better.
If I'm trying to be too clever (or maybe just wrong) or it's pointless, I can remove the `opts.error` condition.
At least for me the tests also serve as references as to how the API is expected to be used, so I think it'd be clearer without signaling that opts.error could potentially be nonzero on success.
An assertion would indeed make that clear.
Thanks for the explanation, Eyal.