From patchwork Sat Jan 20 06:05:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 13524324 X-Patchwork-Delegate: bpf@iogearbox.net Received: from out-183.mta1.migadu.com (out-183.mta1.migadu.com [95.215.58.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 840B517D4 for ; Sat, 20 Jan 2024 06:05:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.183 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705730743; cv=none; b=tFCphGLUr9c1EihvSKvZWmQOC2rb4X0EO7XVDeprwkkXBTRQsmbclBTZJ9FHjQ5f54X68N9o6i4q0cGEXVEgCxTgztegQLNIBjCIUN4Icb22sbbeT46sGzGVB+HBfXAhgAlDv+b6+VW3KOM6jKefORaFroaxF0Z+irtKl1ZTSjE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705730743; c=relaxed/simple; bh=07zpB7nhlm+UulAI8Cl5kQNS8f0PfVi/8BdWRIDof08=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=oEBSJU3TQjkthXiOT0E1arhhHLgBdBCtIuvcEKkdcR6wHriwhCwxuI5mKBdHgvzFHkB6xxV2oFZd0ZYARKLkECgxCDisWSPYsCUYrAPo+c85K+AI5ilQNfJJfamPA4ZOr/2mXExr8tKG0I7oPDjlnK90XogYXmJgYJi5QhsJlHw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=wy6nwEBW; arc=none smtp.client-ip=95.215.58.183 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="wy6nwEBW" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1705730739; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6QBqTwly3G8u9OnviOfAfWIPij/IRbieYJZLSR9SLic=; b=wy6nwEBWJ3OC7wRMTqlvNhT273er9HO+v5zQNq76LuOaKdaj/KHK34MtnUuOCFD+j7IuHL x5yAjUIsHMzx769Tc5Ro3ZVcfdTrxbdg3xgsutrEozwe47r/XKgBJWgN9AqRwcPATAO2k5 yn+gRkH/ueX/xe2n8nj2C8/6UW4Vxas= From: Martin KaFai Lau To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@meta.com Subject: [PATCH v2 bpf-next 2/2] selftests/bpf: Wait for the netstamp_needed_key static key to be turned on Date: Fri, 19 Jan 2024 22:05:18 -0800 Message-Id: <20240120060518.3604920-2-martin.lau@linux.dev> In-Reply-To: <20240120060518.3604920-1-martin.lau@linux.dev> References: <20240120060518.3604920-1-martin.lau@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Patchwork-Delegate: bpf@iogearbox.net From: Martin KaFai Lau 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 --- v2: It is a new patch in v2 to address occasionally missing skb->tstamp in the recvmesg(). .../selftests/bpf/prog_tests/tc_redirect.c | 79 ++++++++++++++++++- 1 file 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)