Add compact regression coverage to the existing LWT IP encapsulation test. Send an IPv4 ping with a Record Route option through an ingress LWT program which prepends a TTL-one IPv4 header, then observe __icmp_send() with fentry and verify that the restored protocol control block no longer contains the inner header's cached option offsets.
Read ctx->cb[0] in the LWT program so the test exercises bpf_prog_run_save_cb()'s save/restore path before the post-run check. Link: https://lore.kernel.org/bpf/[email protected]/ Signed-off-by: Weiming Shi <[email protected]> --- .../selftests/bpf/prog_tests/lwt_ip_encap.c | 45 ++++++++++++++++++ .../selftests/bpf/progs/test_lwt_ip_encap.c | 47 +++++++++++++++++++ 2 files changed, 92 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/lwt_ip_encap.c b/tools/testing/selftests/bpf/prog_tests/lwt_ip_encap.c index 39e8a3b8b6af..14ba33eaeb96 100644 --- a/tools/testing/selftests/bpf/prog_tests/lwt_ip_encap.c +++ b/tools/testing/selftests/bpf/prog_tests/lwt_ip_encap.c @@ -686,3 +686,48 @@ void test_lwt_ip_encap_vxlan_ipv6(void) { lwt_ip_encap_vxlan(IPV6_ENCAP); } + +void test_lwt_ip_encap_stale_cb(void) +{ + char ns1[NETNS_NAME_SIZE] = NETNS_BASE "-1-"; + char ns2[NETNS_NAME_SIZE] = NETNS_BASE "-2-"; + char ns3[NETNS_NAME_SIZE] = NETNS_BASE "-3-"; + struct test_lwt_ip_encap *skel = NULL; + + if (!ASSERT_OK(create_ns(ns1, NETNS_NAME_SIZE), "create ns1")) + goto out; + if (!ASSERT_OK(create_ns(ns2, NETNS_NAME_SIZE), "create ns2")) + goto out; + if (!ASSERT_OK(create_ns(ns3, NETNS_NAME_SIZE), "create ns3")) + goto out; + if (!ASSERT_OK(setup_network(ns1, ns2, ns3, ""), "setup network")) + goto out; + + skel = test_lwt_ip_encap__open(); + if (!ASSERT_OK_PTR(skel, "open")) + goto out; + bpf_program__set_autoload(skel->progs.bpf_lwt_encap_gre, false); + bpf_program__set_autoload(skel->progs.bpf_lwt_encap_gre6, false); + bpf_program__set_autoload(skel->progs.bpf_lwt_encap_vxlan, false); + bpf_program__set_autoload(skel->progs.bpf_lwt_encap_vxlan6, false); + bpf_program__set_autoload(skel->progs.bpf_lwt_encap_stale, false); + if (!ASSERT_OK(test_lwt_ip_encap__load(skel), "load")) + goto out; + if (!ASSERT_OK(test_lwt_ip_encap__attach(skel), "attach")) + goto out; + + SYS(out, "ip -n %s route replace %s/32 encap bpf in obj %s sec encap_stale dev veth3", + ns2, IP4_ADDR_DST, BPF_FILE); + skel->bss->stale_cb_seen = false; + skel->bss->stale_cb_cleared = false; + SYS_NOFAIL("ip netns exec %s ping -q -R -c 1 -W 1 -I veth1 %s >/dev/null 2>&1", + ns1, IP4_ADDR_DST); + ASSERT_TRUE(skel->bss->stale_cb_seen, "stale_cb_seen"); + ASSERT_TRUE(skel->bss->stale_cb_cleared, "stale_cb_cleared"); + +out: + test_lwt_ip_encap__destroy(skel); + SYS_NOFAIL("ip netns del %s", ns1); + SYS_NOFAIL("ip netns del %s", ns2); + SYS_NOFAIL("ip netns del %s", ns3); +} diff --git a/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c b/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c index 4a934fccf8f5..8b57c7fb7fa8 100644 --- a/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c +++ b/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include "vmlinux.h" #include <string.h> +#include <bpf/bpf_core_read.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_endian.h> #include <bpf/bpf_tracing.h> @@ -10,6 +11,8 @@ struct grehdr { __be16 protocol; }; +#define ICMP_TIME_EXCEEDED 11 + SEC("encap_gre") int bpf_lwt_encap_gre(struct __sk_buff *skb) { @@ -80,6 +83,29 @@ int bpf_lwt_encap_gre6(struct __sk_buff *skb) return BPF_LWT_REROUTE; } +SEC("encap_stale") +int bpf_lwt_encap_stale(struct __sk_buff *skb) +{ + struct iphdr iph = {}; + + /* Exercise CB restore before post-run invalidation. */ + if (skb->cb[0]) + return BPF_DROP; + + iph.version = 4; + iph.ihl = 5; + iph.ttl = 1; + iph.protocol = IPPROTO_IPIP; + iph.tot_len = bpf_htons(skb->len + sizeof(iph)); + iph.saddr = bpf_htonl(0xac100264); /* 172.16.2.100 */ + iph.daddr = bpf_htonl(0xac100464); /* 172.16.4.100 */ + + if (bpf_lwt_push_encap(skb, BPF_LWT_ENCAP_IP, &iph, sizeof(iph))) + return BPF_DROP; + + return BPF_OK; +} + #define VXLAN_PORT 4789 #define VXLAN_FLAGS 0x08000000 #define VXLAN_VNI 1 @@ -194,6 +220,27 @@ volatile const int tgt_ip_version; __u16 transport_hdr = 0; __u16 network_hdr = 0; bool fexit_triggered = false; +bool stale_cb_cleared = false; +bool stale_cb_seen = false; + +SEC("fentry/__icmp_send") +int BPF_PROG(fentry_icmp_send, struct sk_buff *skb, int type, int code, + __be32 info, const struct inet_skb_parm *parm) +{ + struct iphdr *iph; + + if (type != ICMP_TIME_EXCEEDED) + return 0; + + iph = (void *)BPF_CORE_READ(skb, head) + BPF_CORE_READ(skb, network_header); + if (BPF_CORE_READ(iph, daddr) != bpf_htonl(0xac100464)) + return 0; + + stale_cb_seen = true; + stale_cb_cleared = !BPF_CORE_READ(parm, opt.optlen) && + !BPF_CORE_READ(parm, opt.rr); + return 0; +} SEC("?fexit/bpf_lwt_push_ip_encap") int BPF_PROG(fexit_lwt_push_ip_encap, struct sk_buff *skb, void *hdr, u32 len, bool ingress, -- 2.55.0
