From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f46.google.com (mail-wm1-f46.google.com [209.85.128.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D67D5365A12 for ; Thu, 9 Jul 2026 14:49:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783608557; cv=none; b=ghGMXs8aMya7Meug7fIAUmDYBeoxV0T1p7TLVLhbaDPwcsUCsnHTLuuy+rBLIxYLFwQPi+JjardaV4eZoePHXdlopybZn58J36XLdhgZzKDz82dvoqmPh+aKHB0OY0T5P2lGV2T3HBkgQ6FfT3FTWiLaSalnvWYLc1LYlSn3qAU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783608557; c=relaxed/simple; bh=9FQXYwGmt4FioywMikvgYSN1ECAwaMBHImy48XF5uQA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=eMEvTgbBWDcgI7tw4WCvEv2+iJg+V3//Geh4hopsDallXfMJv7bR+q0CvppJE2/wBDQwGSd8DV0BVVQTwCNKhjT/AEMaQcdGA9ZyCbexUksfzclZa0Zl8qomnOR+Tg4RnI1Q600P6NeTY1TTjjrGaJAybNSDQAxyJnlbyF7kwWQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Xdaufiqd; arc=none smtp.client-ip=209.85.128.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Xdaufiqd" Received: by mail-wm1-f46.google.com with SMTP id 5b1f17b1804b1-493b1710405so11902925e9.2 for ; Thu, 09 Jul 2026 07:49:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783608554; x=1784213354; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=q6GY6GroFbI4q5Pmm52+Yi7RBYaKaWgF3VvzfzdyKcY=; b=Xdaufiqd5yO9Noz57mi3Kvigw0YoZQR5VBWRMmNeyhMJjAGRPrifVNGDdi00jcZHs6 6z6PyYuagDA6a+YudD6UQ4hEVPMwJO1ZSzu8X1Q8y9gesJZhukqZzx6r/ehgKLUclPXK 68hXeWoGY23AzvPBhw5UNUQPvPyZP6YY2FniHW1x6hYJOh3y61l63K68Vri0XFRWs/yf MRZFx2852CNaawoTQbpFOv171MpBYJUPKW9IkiFK3HvCsCx3y1mYOV/YgnoIKeSPUHXf fUDnyYAg8FUpZugx5NFrNFP1Mx2WOTgTrvVkDVqa852q38Iva1dlIH2NNPbXiDB1EUf3 wA3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783608554; x=1784213354; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=q6GY6GroFbI4q5Pmm52+Yi7RBYaKaWgF3VvzfzdyKcY=; b=L0vSVSIAo/t3uh4e2ER/zs4IcgcoSNXpK2a0Dqxs4fkKfKxUrM6qVMxLqH+6Lu1StH 3+dOQzgmJVOjJ0KnSJmqlY5RcPDwHgfe+NmTa+07NC8q4whsFAHFCGqJ2RzDBz4opRWH TZ4qGGcbHoTX+qBANLINoCBSDDq+koVybi1L+fYogIEJs3zBkCZTWQFDhs2+1SoBIIq7 TLZmgmj41078rPWrNj2DTXhHcbvg2VwyIL9sIhp5sI/rY3CBmY844hkVjtRNMaIcvFdx UtFL5VSpd2GrU8AGezCQ6ozrWnrD77eiThExCxDLEn9kOF6avKbnTNmIX48qOFYIkOaZ HQhw== X-Gm-Message-State: AOJu0Yzt6Y9ZW2azOydN5ZJYMCSBgzkVCGaiERqmwgy6IKkaqNkUNe7z 6niUIcrj02o5/oQz+xGTFIDWjcwJCo8ELM9a8D/zRq/2yXZkZpPzQoGsGg7JYe/Lq3M= X-Gm-Gg: AfdE7clh6NrJ3IJur0RQUCnMoijUx+A9cNbS3SrBIbSybeZfc8eW28AZhn6r9uTRdHy nPA53ExKjxA6r/83f/Xaduf/USB/fxLOW2MVhtyYBilCS57oFg4Vv37zCC6fdjEvmkhThU0GasV 4wFTyKb/C67dThWwolFKLMK1+83PwTLO1r6174+yjLcfFb8Ex0h5GxfpB9eiQGC5JN40tFatg2Y toESJzizkbMLTJKXWSyyEt/2mhz0jFAQrQ1fveZ7IbVbYFQSF58LrKZNCDzzUcftz444smAqyZS zKiBSSxBDnBRW855Scib8SNZebLzAQMuEez1yxxNfaXKP2PVxT2RfBcBuGf4RqaMMe0Qr/TzanJ h1d0XW1OOUuXgOtEPHmfc2hj1QW7ImvSfutftZaGXAJTHUWvq2No1Quh6MMd30TXFTpj7Xnvv7x 9aLA/DBmcBkcbsHbzDsIXLma9drC1UVp5TEYWFEbutg4JNM4QRFstdB9ZT8Q== X-Received: by 2002:a05:600c:4e93:b0:490:e5c1:b8b9 with SMTP id 5b1f17b1804b1-493e67f7c3emr69539015e9.0.1783608553887; Thu, 09 Jul 2026 07:49:13 -0700 (PDT) Received: from mtardy-friendly-lvh-runner.europe-west1-c.c.cilium-dev.internal ([2600:1900:4010:1a8::]) by smtp.googlemail.com with ESMTPSA id 5b1f17b1804b1-493eb6d53absm64357595e9.6.2026.07.09.07.49.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2026 07:49:13 -0700 (PDT) From: Mahe Tardy To: bpf@vger.kernel.org Cc: andrii@kernel.org, ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, jordan@jrife.io, martin.lau@linux.dev, yonghong.song@linux.dev, emil@etsalapatis.com, netdev@vger.kernel.org, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, davem@davemloft.net, horms@kernel.org, sdf.kernel@gmail.com, Mahe Tardy Subject: [PATCH bpf-next v11 2/5] selftests/bpf: add bpf_icmp_send kfunc cgroup_skb tests Date: Thu, 9 Jul 2026 14:48:57 +0000 Message-Id: <20260709144900.245904-3-mahe.tardy@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260709144900.245904-1-mahe.tardy@gmail.com> References: <20260709144900.245904-1-mahe.tardy@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This test opens a server and client, enters a new cgroup, attach a cgroup_skb program on egress and calls the bpf_icmp_send function from the client egress so that an ICMP unreach control message is sent back to the client. It then fetches the message from the error queue to confirm the correct ICMP unreach code has been sent. Note that, for the client, we have to connect in non-blocking mode to let the test execute faster. Otherwise, we need to wait for the TCP three-way handshake to timeout in the kernel before reading the errno. Also note that we don't set IP_RECVERR on the socket in connect_to_fd_nonblock since the error will be transferred anyway in our test because the connection is rejected at the beginning of the TCP handshake. See in net/ipv4/tcp_ipv4.c:tcp_v4_err for more details. Reviewed-by: Jordan Rife Reviewed-by: Emil Tsalapatis Signed-off-by: Mahe Tardy --- .../bpf/prog_tests/icmp_send_kfunc.c | 164 ++++++++++++++++++ tools/testing/selftests/bpf/progs/icmp_send.c | 38 ++++ 2 files changed, 202 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/icmp_send_kfunc.c create mode 100644 tools/testing/selftests/bpf/progs/icmp_send.c diff --git a/tools/testing/selftests/bpf/prog_tests/icmp_send_kfunc.c b/tools/testing/selftests/bpf/prog_tests/icmp_send_kfunc.c new file mode 100644 index 000000000000..b8a98c90053e --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/icmp_send_kfunc.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include "icmp_send.skel.h" + +#define TIMEOUT_MS 1000 + +#define ICMP_DEST_UNREACH 3 + +#define ICMP_FRAG_NEEDED 4 +#define NR_ICMP_UNREACH 15 + +#define KFUNC_RET_UNSET -1 + +static int connect_to_fd_nonblock(int server_fd) +{ + struct sockaddr_storage addr; + socklen_t len = sizeof(addr); + int fd, err; + + if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) + return -1; + + fd = socket(addr.ss_family, SOCK_STREAM | SOCK_NONBLOCK, 0); + if (fd < 0) + return -1; + + err = connect(fd, (struct sockaddr *)&addr, len); + if (err < 0 && errno != EINPROGRESS) { + close(fd); + return -1; + } + + return fd; +} + +static void read_icmp_errqueue(int sockfd, int expected_code) +{ + struct sock_extended_err *sock_err; + char ctrl_buf[512]; + struct msghdr msg = { + .msg_control = ctrl_buf, + .msg_controllen = sizeof(ctrl_buf), + }; + struct pollfd pfd = { + .fd = sockfd, + .events = POLLERR, + }; + struct cmsghdr *cm; + ssize_t n; + + if (!ASSERT_GE(poll(&pfd, 1, TIMEOUT_MS), 1, "poll_errqueue")) + return; + + n = recvmsg(sockfd, &msg, MSG_ERRQUEUE); + if (!ASSERT_GE(n, 0, "recvmsg_errqueue")) + return; + + cm = CMSG_FIRSTHDR(&msg); + if (!ASSERT_NEQ(cm, NULL, "cm_firsthdr_null")) + return; + + for (; cm; cm = CMSG_NXTHDR(&msg, cm)) { + if (cm->cmsg_level != IPPROTO_IP || cm->cmsg_type != IP_RECVERR) + continue; + + sock_err = (struct sock_extended_err *)CMSG_DATA(cm); + + if (!ASSERT_EQ(sock_err->ee_origin, SO_EE_ORIGIN_ICMP, + "sock_err_origin_icmp")) + return; + if (!ASSERT_EQ(sock_err->ee_type, ICMP_DEST_UNREACH, + "sock_err_type_dest_unreach")) + return; + ASSERT_EQ(sock_err->ee_code, expected_code, "sock_err_code"); + return; + } + + ASSERT_FAIL("no IP_RECVERR control message found"); +} + +static bool valid_unreach_code(int code) +{ + if (code < 0) + return false; + + return code <= NR_ICMP_UNREACH && code != ICMP_FRAG_NEEDED; +} + +static void trigger_prog_read_icmp_errqueue(struct icmp_send *skel, int code) +{ + int srv_fd = -1, client_fd = -1; + int port; + + srv_fd = start_server(AF_INET, SOCK_STREAM, "127.0.0.1", 0, TIMEOUT_MS); + if (!ASSERT_OK_FD(srv_fd, "start_server")) + return; + + port = get_socket_local_port(srv_fd); + if (!ASSERT_GE(port, 0, "get_socket_local_port")) { + close(srv_fd); + return; + } + + skel->bss->server_port = ntohs(port); + skel->bss->unreach_code = code; + skel->data->kfunc_ret = KFUNC_RET_UNSET; + + client_fd = connect_to_fd_nonblock(srv_fd); + if (!ASSERT_OK_FD(client_fd, "client_connect_nonblock")) { + close(srv_fd); + return; + } + + if (valid_unreach_code(code)) + read_icmp_errqueue(client_fd, code); + + close(client_fd); + close(srv_fd); +} + +void test_icmp_send_unreach_cgroup(void) +{ + struct icmp_send *skel; + int cgroup_fd = -1; + + skel = icmp_send__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + goto cleanup; + + cgroup_fd = test__join_cgroup("/icmp_send_unreach_cgroup"); + if (!ASSERT_OK_FD(cgroup_fd, "join_cgroup")) + goto cleanup; + + skel->links.egress = + bpf_program__attach_cgroup(skel->progs.egress, cgroup_fd); + if (!ASSERT_OK_PTR(skel->links.egress, "prog_attach_cgroup")) + goto cleanup; + + for (int code = 0; code <= NR_ICMP_UNREACH; code++) { + if (code == ICMP_FRAG_NEEDED) + continue; + + trigger_prog_read_icmp_errqueue(skel, code); + ASSERT_EQ(skel->data->kfunc_ret, 0, "kfunc_ret"); + } + + /* Test invalid codes */ + trigger_prog_read_icmp_errqueue(skel, -1); + ASSERT_EQ(skel->data->kfunc_ret, -EINVAL, "kfunc_ret"); + + trigger_prog_read_icmp_errqueue(skel, NR_ICMP_UNREACH + 1); + ASSERT_EQ(skel->data->kfunc_ret, -EINVAL, "kfunc_ret"); + + trigger_prog_read_icmp_errqueue(skel, ICMP_FRAG_NEEDED); + ASSERT_EQ(skel->data->kfunc_ret, -EINVAL, "kfunc_ret"); + +cleanup: + icmp_send__destroy(skel); + if (cgroup_fd >= 0) + close(cgroup_fd); +} diff --git a/tools/testing/selftests/bpf/progs/icmp_send.c b/tools/testing/selftests/bpf/progs/icmp_send.c new file mode 100644 index 000000000000..6d0be0a9afe1 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/icmp_send.c @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "vmlinux.h" +#include +#include + +/* 127.0.0.1 in host byte order */ +#define SERVER_IP 0x7F000001 + +#define ICMP_DEST_UNREACH 3 + +__u16 server_port = 0; +int unreach_code = 0; +int kfunc_ret = -1; + +SEC("cgroup_skb/egress") +int egress(struct __sk_buff *skb) +{ + void *data = (void *)(long)skb->data; + void *data_end = (void *)(long)skb->data_end; + struct iphdr *iph; + struct tcphdr *tcph; + + iph = data; + if ((void *)(iph + 1) > data_end || iph->version != 4 || + iph->protocol != IPPROTO_TCP || iph->daddr != bpf_htonl(SERVER_IP)) + return SK_PASS; + + tcph = (void *)iph + iph->ihl * 4; + if ((void *)(tcph + 1) > data_end || + tcph->dest != bpf_htons(server_port)) + return SK_PASS; + + kfunc_ret = bpf_icmp_send(skb, ICMP_DEST_UNREACH, unreach_code); + + return SK_DROP; +} + +char LICENSE[] SEC("license") = "Dual BSD/GPL"; -- 2.34.1