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author | Martin KaFai Lau <martin.lau@kernel.org> | 2024-01-20 09:05:18 +0300 |
---|---|---|
committer | Sasha Levin <sashal@kernel.org> | 2024-03-27 01:16:33 +0300 |
commit | 1508baac0b258f9349a7bbb2b843b15555386e7e (patch) | |
tree | 01b6822588be14f762397de99234b0738eb1ab05 /tools | |
parent | 2c2e391d2db8fb6659e20cf42a879c94042eb666 (diff) | |
download | linux-1508baac0b258f9349a7bbb2b843b15555386e7e.tar.xz |
selftests/bpf: Wait for the netstamp_needed_key static key to be turned on
[ Upstream commit ce6f6cffaeaa0a3bcdafcae7fe03c68c3afae631 ]
After the previous patch that speeded up the test (by avoiding neigh
discovery in IPv6), the BPF CI occasionally hits this error:
rcv tstamp unexpected pkt rcv tstamp: actual 0 == expected 0
The test complains about the cmsg returned from the recvmsg() does not
have the rcv timestamp. Setting skb->tstamp or not is
controlled by a kernel static key "netstamp_needed_key". The static
key is enabled whenever this is at least one sk with the SOCK_TIMESTAMP
set.
The test_redirect_dtime does use setsockopt() to turn on
the SOCK_TIMESTAMP for the reading sk. In the kernel
net_enable_timestamp() has a delay to enable the "netstamp_needed_key"
when CONFIG_JUMP_LABEL is set. This potential delay is the likely reason
for packet missing rcv timestamp occasionally.
This patch is to create udp sockets with SOCK_TIMESTAMP set.
It sends and receives some packets until the received packet
has a rcv timestamp. It currently retries at most 5 times with 1s
in between. This should be enough to wait for the "netstamp_needed_key".
It then holds on to the socket and only closes it at the end of the test.
This guarantees that the test has the "netstamp_needed_key" key turned
on from the beginning.
To simplify the udp sockets setup, they are sending/receiving packets
in the same netns (ns_dst is used) and communicate over the "lo" dev.
Hence, the patch enables the "lo" dev in the ns_dst.
Fixes: c803475fd8dd ("bpf: selftests: test skb->tstamp in redirect_neigh")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240120060518.3604920-2-martin.lau@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/tc_redirect.c | 79 |
1 files changed, 75 insertions, 4 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c index 610887157fd8..dbe06aeaa2b2 100644 --- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c +++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c @@ -291,6 +291,7 @@ static int netns_setup_links_and_routes(struct netns_setup_result *result) SYS(fail, "ip addr add " IP4_DST "/32 dev dst"); SYS(fail, "ip addr add " IP6_DST "/128 dev dst nodad"); SYS(fail, "ip link set dev dst up"); + SYS(fail, "ip link set dev lo up"); SYS(fail, "ip route add " IP4_SRC "/32 dev dst scope global"); SYS(fail, "ip route add " IP4_NET "/16 dev dst scope global"); @@ -468,7 +469,7 @@ static int set_forwarding(bool enable) return 0; } -static void rcv_tstamp(int fd, const char *expected, size_t s) +static int __rcv_tstamp(int fd, const char *expected, size_t s, __u64 *tstamp) { struct __kernel_timespec pkt_ts = {}; char ctl[CMSG_SPACE(sizeof(pkt_ts))]; @@ -489,7 +490,7 @@ static void rcv_tstamp(int fd, const char *expected, size_t s) ret = recvmsg(fd, &msg, 0); if (!ASSERT_EQ(ret, s, "recvmsg")) - return; + return -1; ASSERT_STRNEQ(data, expected, s, "expected rcv data"); cmsg = CMSG_FIRSTHDR(&msg); @@ -498,6 +499,12 @@ static void rcv_tstamp(int fd, const char *expected, size_t s) memcpy(&pkt_ts, CMSG_DATA(cmsg), sizeof(pkt_ts)); pkt_ns = pkt_ts.tv_sec * NSEC_PER_SEC + pkt_ts.tv_nsec; + if (tstamp) { + /* caller will check the tstamp itself */ + *tstamp = pkt_ns; + return 0; + } + ASSERT_NEQ(pkt_ns, 0, "pkt rcv tstamp"); ret = clock_gettime(CLOCK_REALTIME, &now_ts); @@ -507,6 +514,60 @@ static void rcv_tstamp(int fd, const char *expected, size_t s) if (ASSERT_GE(now_ns, pkt_ns, "check rcv tstamp")) ASSERT_LT(now_ns - pkt_ns, 5 * NSEC_PER_SEC, "check rcv tstamp"); + return 0; +} + +static void rcv_tstamp(int fd, const char *expected, size_t s) +{ + __rcv_tstamp(fd, expected, s, NULL); +} + +static int wait_netstamp_needed_key(void) +{ + int opt = 1, srv_fd = -1, cli_fd = -1, nretries = 0, err, n; + char buf[] = "testing testing"; + struct nstoken *nstoken; + __u64 tstamp = 0; + + nstoken = open_netns(NS_DST); + if (!nstoken) + return -1; + + srv_fd = start_server(AF_INET6, SOCK_DGRAM, "::1", 0, 0); + if (!ASSERT_GE(srv_fd, 0, "start_server")) + goto done; + + err = setsockopt(srv_fd, SOL_SOCKET, SO_TIMESTAMPNS_NEW, + &opt, sizeof(opt)); + if (!ASSERT_OK(err, "setsockopt(SO_TIMESTAMPNS_NEW)")) + goto done; + + cli_fd = connect_to_fd(srv_fd, TIMEOUT_MILLIS); + if (!ASSERT_GE(cli_fd, 0, "connect_to_fd")) + goto done; + +again: + n = write(cli_fd, buf, sizeof(buf)); + if (!ASSERT_EQ(n, sizeof(buf), "send to server")) + goto done; + err = __rcv_tstamp(srv_fd, buf, sizeof(buf), &tstamp); + if (!ASSERT_OK(err, "__rcv_tstamp")) + goto done; + if (!tstamp && nretries++ < 5) { + sleep(1); + printf("netstamp_needed_key retry#%d\n", nretries); + goto again; + } + +done: + if (!tstamp && srv_fd != -1) { + close(srv_fd); + srv_fd = -1; + } + if (cli_fd != -1) + close(cli_fd); + close_netns(nstoken); + return srv_fd; } static void snd_tstamp(int fd, char *b, size_t s) @@ -843,11 +904,20 @@ static void test_tc_redirect_dtime(struct netns_setup_result *setup_result) { struct test_tc_dtime *skel; struct nstoken *nstoken; - int err; + int hold_tstamp_fd, err; + + /* Hold a sk with the SOCK_TIMESTAMP set to ensure there + * is no delay in the kernel net_enable_timestamp(). + * This ensures the following tests must have + * non zero rcv tstamp in the recvmsg(). + */ + hold_tstamp_fd = wait_netstamp_needed_key(); + if (!ASSERT_GE(hold_tstamp_fd, 0, "wait_netstamp_needed_key")) + return; skel = test_tc_dtime__open(); if (!ASSERT_OK_PTR(skel, "test_tc_dtime__open")) - return; + goto done; skel->rodata->IFINDEX_SRC = setup_result->ifindex_src_fwd; skel->rodata->IFINDEX_DST = setup_result->ifindex_dst_fwd; @@ -892,6 +962,7 @@ static void test_tc_redirect_dtime(struct netns_setup_result *setup_result) done: test_tc_dtime__destroy(skel); + close(hold_tstamp_fd); } static void test_tc_redirect_neigh_fib(struct netns_setup_result *setup_result) |