From: Daniel Borkmann daniel@iogearbox.net

[ Upstream commit 5f1d18de79180deac2822c93e431bbe547f7d3ce ]

Add a test case which replaces an active ingress qdisc while keeping the miniq in-tact during the transition period to the new clsact qdisc.

# ./vmtest.sh -- ./test_progs -t tc_link [...] ./test_progs -t tc_link [ 3.412871] bpf_testmod: loading out-of-tree module taints kernel. [ 3.413343] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #332 tc_links_after:OK #333 tc_links_append:OK #334 tc_links_basic:OK #335 tc_links_before:OK #336 tc_links_chain_classic:OK #337 tc_links_chain_mixed:OK #338 tc_links_dev_chain0:OK #339 tc_links_dev_cleanup:OK #340 tc_links_dev_mixed:OK #341 tc_links_ingress:OK #342 tc_links_invalid:OK #343 tc_links_prepend:OK #344 tc_links_replace:OK #345 tc_links_revision:OK Summary: 14/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann daniel@iogearbox.net Cc: Martin KaFai Lau martin.lau@kernel.org Link: https://lore.kernel.org/r/20240708133130.11609-2-daniel@iogearbox.net Signed-off-by: Martin KaFai Lau martin.lau@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/bpf/config | 3 + .../selftests/bpf/prog_tests/tc_links.c | 61 +++++++++++++++++++ 2 files changed, 64 insertions(+)

diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index 01f241ea2c67b..dec9fd7ebba7f 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -53,9 +53,12 @@ CONFIG_MPLS=y CONFIG_MPLS_IPTUNNEL=y CONFIG_MPLS_ROUTING=y CONFIG_MPTCP=y +CONFIG_NET_ACT_SKBMOD=y +CONFIG_NET_CLS=y CONFIG_NET_CLS_ACT=y CONFIG_NET_CLS_BPF=y CONFIG_NET_CLS_FLOWER=y +CONFIG_NET_CLS_MATCHALL=y CONFIG_NET_FOU=y CONFIG_NET_FOU_IP_TUNNELS=y CONFIG_NET_IPGRE=y diff --git a/tools/testing/selftests/bpf/prog_tests/tc_links.c b/tools/testing/selftests/bpf/prog_tests/tc_links.c index bc98411446855..1af9ec1149aab 100644 --- a/tools/testing/selftests/bpf/prog_tests/tc_links.c +++ b/tools/testing/selftests/bpf/prog_tests/tc_links.c @@ -9,6 +9,8 @@ #define ping_cmd "ping -q -c1 -w1 127.0.0.1 > /dev/null"

#include "test_tc_link.skel.h" + +#include "netlink_helpers.h" #include "tc_helpers.h"

void serial_test_tc_links_basic(void) @@ -1787,6 +1789,65 @@ void serial_test_tc_links_ingress(void) test_tc_links_ingress(BPF_TCX_INGRESS, false, false); }

+struct qdisc_req { + struct nlmsghdr n; + struct tcmsg t; + char buf[1024]; +}; + +static int qdisc_replace(int ifindex, const char *kind, bool block) +{ + struct rtnl_handle rth = { .fd = -1 }; + struct qdisc_req req; + int err; + + err = rtnl_open(&rth, 0); + if (!ASSERT_OK(err, "open_rtnetlink")) + return err; + + memset(&req, 0, sizeof(req)); + req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); + req.n.nlmsg_flags = NLM_F_CREATE | NLM_F_REPLACE | NLM_F_REQUEST; + req.n.nlmsg_type = RTM_NEWQDISC; + req.t.tcm_family = AF_UNSPEC; + req.t.tcm_ifindex = ifindex; + req.t.tcm_parent = 0xfffffff1; + + addattr_l(&req.n, sizeof(req), TCA_KIND, kind, strlen(kind) + 1); + if (block) + addattr32(&req.n, sizeof(req), TCA_INGRESS_BLOCK, 1); + + err = rtnl_talk(&rth, &req.n, NULL); + ASSERT_OK(err, "talk_rtnetlink"); + rtnl_close(&rth); + return err; +} + +void serial_test_tc_links_dev_chain0(void) +{ + int err, ifindex; + + ASSERT_OK(system("ip link add dev foo type veth peer name bar"), "add veth"); + ifindex = if_nametoindex("foo"); + ASSERT_NEQ(ifindex, 0, "non_zero_ifindex"); + err = qdisc_replace(ifindex, "ingress", true); + if (!ASSERT_OK(err, "attaching ingress")) + goto cleanup; + ASSERT_OK(system("tc filter add block 1 matchall action skbmod swap mac"), "add block"); + err = qdisc_replace(ifindex, "clsact", false); + if (!ASSERT_OK(err, "attaching clsact")) + goto cleanup; + /* Heuristic: kern_sync_rcu() alone does not work; a wait-time of ~5s + * triggered the issue without the fix reliably 100% of the time. + */ + sleep(5); + ASSERT_OK(system("tc filter add dev foo ingress matchall action skbmod swap mac"), "add filter"); +cleanup: + ASSERT_OK(system("ip link del dev foo"), "del veth"); + ASSERT_EQ(if_nametoindex("foo"), 0, "foo removed"); + ASSERT_EQ(if_nametoindex("bar"), 0, "bar removed"); +} + static void test_tc_links_dev_mixed(int target) { LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);