From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (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 20D293749E8 for ; Thu, 11 Jun 2026 08:09:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781165364; cv=none; b=sMXKzGOHSukB71dw07VCpee9QobXinluI/42MM3Uwe9PD2JOlvOY4Yipp9SdPpbVzbb+pHl7FYotNrNccY0fMOQ4jf+enf5xYO+7I7NkzQX8mB8OwcN6P/2cqcxwJNjEQovmlWK0HYw7L+z4EJhUUu3MtjB/psBdD9zj9qM9jWQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781165364; c=relaxed/simple; bh=fLiLl3V0CgYI1k2r0nXl+Hv1z/JdJstVhTKAWntg5NE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Uy3pW01Gm+/VHYhdXKvEybZYmad7L2ROFnVdjcoHYgzycONRTKzkFPOk88nyFALQNaT13DeCaxmlxlavClQd2Sll4bve9xgJXVfRyqluXhCg9UxM5iwjOolwS7OyPuUbekgD2Mi/E8TiPJ8yRCOOvS4BWKxaakRzAfwCEUL7ImQ= 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=WqHPd6bz; arc=none smtp.client-ip=209.85.214.182 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="WqHPd6bz" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-2bf0ddaf50fso53026455ad.1 for ; Thu, 11 Jun 2026 01:09:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1781165362; x=1781770162; 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; bh=fSWHG/fZwGNdDcsSNE8Dmg90eYdiDIo5tjPEs/CIw8s=; b=WqHPd6bza4PNBcUQKM4KGJvPh1Q/Lvce0KCR+I0jBnuF7RAX9NQZH4zCTsqvxg0jY/ fEIy1fcdaeOH9w2iuC4phUO+ddSBO7f+i3LI9qDbL1gWqRkiDjuHJ5n5tG7gb/Yzn2eN FnuEmHNeXBWr+AEkRd6wNj2PdI1Ki7Kk7lfRrdAJtgXQYa+aZ8uOeIwBPesG/OJseYf8 069OA9kOjMVWXOCgY1ZpVwsA5pSxVnxF1U4vmA5JXRc+HiGcBYLR96T9KWJZWJwOd4Vm rhiXNJ30eY+IrcNq5nXhXppGcqLEEnpdmmOleGVDPLhT85aS0UeV3VOA2UCmZ2higr/0 xNKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781165362; x=1781770162; 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; bh=fSWHG/fZwGNdDcsSNE8Dmg90eYdiDIo5tjPEs/CIw8s=; b=N/5YtODowExwXg5VrHllo9sePM6F1nget2iMTUS7j7PyqRi998i1DZRIMhZSNI1QZt 6ka+4bnUEH4dUHgu1Cb+Y4UYvYqFCEYPKaef/Htmzha0G6MXVix3x3wgMXjejX7y+kUf 58dzp5Xp3fPFssTKtouh6q0jZznL9C1BPF4N7RvPmUQmzz+P36yl6pzfUvkYfhStHA7c kKDdXJTMYMcGUIcD18SU40Fowh2+SqZELQBRLQ6Fy2YslzFrYfNHxtp0Qec/o95gmo58 RfBUJckuxRC9Lcs1qKRF5C3DSeUaEbVL/Ay636NH/5y0RyHrBCHIQTgC7acGMTJPgzTn 7H+w== X-Gm-Message-State: AOJu0YyuojaS8bQsppM4GID7UIqSP1O3IkqL8HJ2YrXS5HwHAB+whciS 0zVKtMLdMhpBjgOGyaPsdReK4omQLzuknN+HeevCs9spadHUE0jiJ1I7 X-Gm-Gg: Acq92OHUyVOaSp5YXPFWXX2eD9Lr6JeqrbHeinuCwTRxrPOvytXeFKQ4mfQaVsE12zX pSgrpymCyI7vOFiKwtoeAUE8jwk/Lq08GZRZmaBmR+h+WUUM89x7Nxh6xiBfZxeTg8W2EH/hs0+ OV8Su28TBZzoMhijz1YWmbWwBnbRwbXuMb4tWUtJoQCbb45EHogwJ3FePVrecFyWTLVV2m+0N1A Ppj4ihCWNgzFbjKTiutAFUM/VLGfrYBIsemLM6c48QCIodIHluiPen/Y/OoxZ8APsIRaILE3TpR /vC4uHbAvRrNFBClUCyRav8SBwmYqo93rin9rYcr4Yu1lpI1SBk6qfZ84mHo30NP+pMdujkvkRW sbPGwf60MIvenvN8Vq5FVA2vR6lF/as1N1R8pKJzYNmG5u2/gOiTHC+Pza7e0uD18t035N1OnzO 8XSLY7nqJwNQW/4KjXS/3BmIAN6UBEU2LON7qqf23IZB+j3mpzth5cIfVEqewMvE15+JpLZxJ5b OJ8y8FoTKESgmJbjX5TX1q26QYN X-Received: by 2002:a17:903:2408:b0:2ba:7881:948d with SMTP id d9443c01a7336-2c2f18e2accmr20789065ad.1.1781165362432; Thu, 11 Jun 2026 01:09:22 -0700 (PDT) Received: from u2404-VMware-Virtual-Platform.localdomain ([2a12:a304:100::109f]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2c1664ad138sm277591035ad.82.2026.06.11.01.09.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Jun 2026 01:09:22 -0700 (PDT) From: Sun Jian To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, davem@davemloft.net, kuba@kernel.org, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, shuah@kernel.org, jiayuan.chen@linux.dev, toke@redhat.com, menglong.dong@linux.dev, emil@etsalapatis.com, Sun Jian Subject: [PATCH bpf v4 2/2] selftests/bpf: Cover generic devmap egress last-dst rewrite Date: Thu, 11 Jun 2026 16:08:49 +0800 Message-ID: <20260611080850.536996-3-sun.jian.kdev@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260611080850.536996-1-sun.jian.kdev@gmail.com> References: <20260611080850.536996-1-sun.jian.kdev@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Strengthen xdp_veth_egress to check that each destination observes the MAC selected for its own egress ifindex, instead of only checking that the observed MAC differs from a single magic value. Add a generic XDP last-destination test where earlier destinations do not have a devmap egress program while the final destination does. This covers the case where the final destination runs on the original skb and could otherwise rewrite packet data still shared with earlier cloned skbs. Use deterministic DEVMAP_HASH keys for the egress map so the intended last destination is stable. Suggested-by: Jiayuan Chen Signed-off-by: Sun Jian --- .../selftests/bpf/prog_tests/test_xdp_veth.c | 152 +++++++++++++++++- 1 file changed, 149 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c b/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c index 3e98a1665936..0fa2cf835c62 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c +++ b/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c @@ -456,7 +456,11 @@ static void xdp_veth_egress(u32 flags) .remote_flags = flags, } }; - const char magic_mac[6] = { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF}; + const unsigned char egress_macs[VETH_PAIRS_COUNT][ETH_ALEN] = { + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x01 }, + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x02 }, + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x03 }, + }; struct xdp_redirect_multi_kern *xdp_redirect_multi_kern; struct bpf_object *bpf_objs[VETH_EGRESS_SKEL_NB]; struct xdp_redirect_map *xdp_redirect_map; @@ -512,7 +516,7 @@ static void xdp_veth_egress(u32 flags) &net_config, prog_cfg, i)) goto destroy_xdp_redirect_map; - err = bpf_map_update_elem(mac_map, &ifindex, magic_mac, 0); + err = bpf_map_update_elem(mac_map, &ifindex, egress_macs[i], 0); if (!ASSERT_OK(err, "bpf_map_update_elem")) goto destroy_xdp_redirect_map; @@ -530,16 +534,155 @@ static void xdp_veth_egress(u32 flags) goto destroy_xdp_redirect_map; for (i = 0; i < 2; i++) { + u32 key = i; + __be64 expected = 0; + u64 res; + + err = bpf_map_lookup_elem(res_map, &key, &res); + if (!ASSERT_OK(err, "get MAC res")) + goto destroy_xdp_redirect_map; + + /* store_mac_1/2 run on the second/third remote veths. */ + memcpy(&expected, egress_macs[i + 1], ETH_ALEN); + ASSERT_EQ(res, expected, "compare mac"); + } + +destroy_xdp_redirect_map: + close_netns(nstoken); + xdp_redirect_map__destroy(xdp_redirect_map); +destroy_xdp_redirect_multi_kern: + xdp_redirect_multi_kern__destroy(xdp_redirect_multi_kern); +destroy_xdp_dummy: + xdp_dummy__destroy(xdp_dummy); + + cleanup_network(&net_config); +} + +static void xdp_veth_egress_last_dst(u32 flags) +{ + struct prog_configuration prog_cfg[VETH_PAIRS_COUNT] = { + { + .local_name = "xdp_redirect_map_all_prog", + .remote_name = "store_mac_1", + .local_flags = flags, + .remote_flags = flags, + }, + { + .local_name = "xdp_redirect_map_all_prog", + .remote_name = "store_mac_2", + .local_flags = flags, + .remote_flags = flags, + }, + { + .local_name = "xdp_redirect_map_all_prog", + .remote_name = "xdp_dummy_prog", + .local_flags = flags, + .remote_flags = flags, + } + }; + const unsigned char egress_macs[VETH_PAIRS_COUNT][ETH_ALEN] = { + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x01 }, + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x02 }, + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x03 }, + }; + struct xdp_redirect_multi_kern *xdp_redirect_multi_kern; + struct bpf_object *bpf_objs[VETH_EGRESS_SKEL_NB]; + struct xdp_redirect_map *xdp_redirect_map; + struct net_configuration net_config = {}; + int mac_map, egress_map, res_map; + struct nstoken *nstoken = NULL; + struct xdp_dummy *xdp_dummy; + __be64 last_mac = 0; + bool found = false; + int err; + int i; + + xdp_dummy = xdp_dummy__open_and_load(); + if (!ASSERT_OK_PTR(xdp_dummy, "xdp_dummy__open_and_load")) + return; + + xdp_redirect_multi_kern = xdp_redirect_multi_kern__open_and_load(); + if (!ASSERT_OK_PTR(xdp_redirect_multi_kern, "xdp_redirect_multi_kern__open_and_load")) + goto destroy_xdp_dummy; + + xdp_redirect_map = xdp_redirect_map__open_and_load(); + if (!ASSERT_OK_PTR(xdp_redirect_map, "xdp_redirect_map__open_and_load")) + goto destroy_xdp_redirect_multi_kern; + + if (!ASSERT_OK(create_network(&net_config), "create network")) + goto destroy_xdp_redirect_map; + + mac_map = bpf_map__fd(xdp_redirect_multi_kern->maps.mac_map); + if (!ASSERT_OK_FD(mac_map, "open mac_map")) + goto destroy_xdp_redirect_map; + + egress_map = bpf_map__fd(xdp_redirect_multi_kern->maps.map_egress); + if (!ASSERT_OK_FD(egress_map, "open map_egress")) + goto destroy_xdp_redirect_map; + + bpf_objs[0] = xdp_dummy->obj; + bpf_objs[1] = xdp_redirect_multi_kern->obj; + bpf_objs[2] = xdp_redirect_map->obj; + + nstoken = open_netns(net_config.ns0_name); + if (!ASSERT_OK_PTR(nstoken, "open NS0")) + goto destroy_xdp_redirect_map; + + for (i = 0; i < VETH_PAIRS_COUNT; i++) { + struct bpf_devmap_val devmap_val = {}; + int ifindex = if_nametoindex(net_config.veth_cfg[i].local_veth); + u32 key = i; + + SYS(destroy_xdp_redirect_map, + "ip -n %s neigh add %s lladdr 00:00:00:00:00:01 dev %s", + net_config.veth_cfg[i].namespace, IP_NEIGH, + net_config.veth_cfg[i].remote_veth); + + if (attach_programs_to_veth_pair(bpf_objs, VETH_EGRESS_SKEL_NB, + &net_config, prog_cfg, i)) + goto destroy_xdp_redirect_map; + + err = bpf_map_update_elem(mac_map, &ifindex, egress_macs[i], 0); + if (!ASSERT_OK(err, "bpf_map_update_elem")) + goto destroy_xdp_redirect_map; + + devmap_val.ifindex = ifindex; + devmap_val.bpf_prog.fd = -1; + + if (i == VETH_PAIRS_COUNT - 1) + devmap_val.bpf_prog.fd = + bpf_program__fd(xdp_redirect_multi_kern->progs.xdp_devmap_prog); + + err = bpf_map_update_elem(egress_map, &key, &devmap_val, 0); + if (!ASSERT_OK(err, "bpf_map_update_elem")) + goto destroy_xdp_redirect_map; + } + + SYS_NOFAIL("ip netns exec %s ping %s -i 0.1 -c 4 -W1 > /dev/null ", + net_config.veth_cfg[0].namespace, IP_NEIGH); + + res_map = bpf_map__fd(xdp_redirect_map->maps.rx_mac); + if (!ASSERT_OK_FD(res_map, "open rx_map")) + goto destroy_xdp_redirect_map; + + memcpy(&last_mac, egress_macs[VETH_PAIRS_COUNT - 1], ETH_ALEN); + + for (i = 0; i < VETH_PAIRS_COUNT - 1; i++) { u32 key = i; u64 res; err = bpf_map_lookup_elem(res_map, &key, &res); + if (err == -ENOENT) + continue; if (!ASSERT_OK(err, "get MAC res")) goto destroy_xdp_redirect_map; - ASSERT_STRNEQ((const char *)&res, magic_mac, ETH_ALEN, "compare mac"); + found = true; + ASSERT_NEQ(res, last_mac, "compare last dst mac"); } + ASSERT_TRUE(found, "found earlier dst mac"); + destroy_xdp_redirect_map: close_netns(nstoken); xdp_redirect_map__destroy(xdp_redirect_map); @@ -596,4 +739,7 @@ void test_xdp_veth_egress(void) if (test__start_subtest("SKB_MODE/egress")) xdp_veth_egress(XDP_FLAGS_SKB_MODE); + + if (test__start_subtest("SKB_MODE/egress_last_dst")) + xdp_veth_egress_last_dst(XDP_FLAGS_SKB_MODE); } -- 2.43.0