From patchwork Wed Jan 5 13:18:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 530579 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FE7BC433FE for ; Wed, 5 Jan 2022 13:21:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240214AbiAENVA (ORCPT ); Wed, 5 Jan 2022 08:21:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240158AbiAENU6 (ORCPT ); Wed, 5 Jan 2022 08:20:58 -0500 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30C8FC061761; Wed, 5 Jan 2022 05:20:58 -0800 (PST) Received: by mail-pl1-x643.google.com with SMTP id x15so29312501plg.1; Wed, 05 Jan 2022 05:20:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=E2ecUMplQVNC6A29lLi9+Ao3qvZ6ZTpS/L9NYSl/HFs=; b=gXp7y1SUFRjKk40Aju1cnY1ZFzkEXo3JDEbGjXR9+3QXBnD/elCayClb74JuLOYHBp nmA7afYZ68oVCKv2UqQiBXjpToCD8ghyJPoiQQ+D+PWY5Ru+ZJcI8HNotqG0QLqqm/3W Ijxjwi1KDUGjQZ3ifVD6WrVsFpZUXYncs+Bf7juEaPJpcIIUxxeybJknfh7ILdQfnQMz aZ4FIvt2S1YZIOc9XX2jCx1HDqJaY4ZNEmmV13jTFmYR5Z9nf+6QviYTMl4NKEkPh3kk VWmhd3NFCbxqDjXr1rQ3sUvY6NF6B/cx6WhAckDJ78UUPh5yPP1gfexBriTVB9longxC Yl6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=E2ecUMplQVNC6A29lLi9+Ao3qvZ6ZTpS/L9NYSl/HFs=; b=Zv+tApnj9zXJUkyZ/cURbcu1gVoJuGJjc1ylBAchFLI1Oy3RgWpYNxGOtVVKPEiLqD pNqxoW1BaAadcw+x7wzUSmcPUtHMlAzPOXdB5hTazTMRIWv/3zIsp9pGe1MfXjyC58bq 9yZOEdNmAcce/rMy04If+KQhW4uB33Aa9Vmdgr4IoIcfPzpWQ78pGxGnugswO4BE0a/y VMfkGME6mRGv7CngoaTXz33Q0K8pK3qPui/pYFkaNCn01hlmWsZsGUnKG/GrHEbDTsV8 m6Dn1vEdJ8ZFn4mZ/edK/eiESHeJMcX1aQONYK3IOEhTQJC/yUR39FA5AucNA0Ydsupu +kpw== X-Gm-Message-State: AOAM533634cfLpaMaRjlS36q7xdUSIe89Cz5S4QU3tCEwibz1ihSAQLp lXl9rP5YdPYndN8YOmYUuqo= X-Google-Smtp-Source: ABdhPJwtoPBJeP24Kmnv/qQpt8hOFgwv+81/+PVtP5ABlEzeKYVG76uvWA9JCS0o1sNPUtVhr+6cQA== X-Received: by 2002:a17:90b:350b:: with SMTP id ls11mr4015871pjb.134.1641388857784; Wed, 05 Jan 2022 05:20:57 -0800 (PST) Received: from localhost.localdomain ([43.132.141.9]) by smtp.gmail.com with ESMTPSA id q17sm16227771pfj.119.2022.01.05.05.20.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jan 2022 05:20:57 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org, daniel@iogearbox.net Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, edumazet@google.com, shuah@kernel.org, ast@kernel.org, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, bpf@vger.kernel.org, Menglong Dong Subject: [PATCH v3 net-next 1/2] net: bpf: handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() Date: Wed, 5 Jan 2022 21:18:48 +0800 Message-Id: <20220105131849.2559506-2-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220105131849.2559506-1-imagedong@tencent.com> References: <20220105131849.2559506-1-imagedong@tencent.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Menglong Dong The return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() in __inet_bind() is not handled properly. While the return value is non-zero, it will set inet_saddr and inet_rcv_saddr to 0 and exit: err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); if (err) { inet->inet_saddr = inet->inet_rcv_saddr = 0; goto out_release_sock; } Let's take UDP for example and see what will happen. For UDP socket, it will be added to 'udp_prot.h.udp_table->hash' and 'udp_prot.h.udp_table->hash2' after the sk->sk_prot->get_port() called success. If 'inet->inet_rcv_saddr' is specified here, then 'sk' will be in the 'hslot2' of 'hash2' that it don't belong to (because inet_saddr is changed to 0), and UDP packet received will not be passed to this sock. If 'inet->inet_rcv_saddr' is not specified here, the sock will work fine, as it can receive packet properly, which is wired, as the 'bind()' is already failed. To undo the get_port() operation, introduce the 'put_port' field for 'struct proto'. For TCP proto, it is inet_put_port(); For UDP proto, it is udp_lib_unhash(); For icmp proto, it is ping_unhash(). Therefore, after sys_bind() fail caused by BPF_CGROUP_RUN_PROG_INET4_POST_BIND(), it will be unbinded, which means that it can try to be binded to another port. Signed-off-by: Menglong Dong --- v3: - NULL check for sk->sk_prot->put_port v2: - introduce 'put_port' field for 'struct proto' --- include/net/sock.h | 1 + net/ipv4/af_inet.c | 2 ++ net/ipv4/ping.c | 1 + net/ipv4/tcp_ipv4.c | 1 + net/ipv4/udp.c | 1 + net/ipv6/af_inet6.c | 2 ++ net/ipv6/ping.c | 1 + net/ipv6/tcp_ipv6.c | 1 + net/ipv6/udp.c | 1 + 9 files changed, 11 insertions(+) diff --git a/include/net/sock.h b/include/net/sock.h index 7b4b4237e6e0..ff9b508d9c5f 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1209,6 +1209,7 @@ struct proto { void (*unhash)(struct sock *sk); void (*rehash)(struct sock *sk); int (*get_port)(struct sock *sk, unsigned short snum); + void (*put_port)(struct sock *sk); #ifdef CONFIG_BPF_SYSCALL int (*psock_update_sk_prot)(struct sock *sk, struct sk_psock *psock, diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index f53184767ee7..9c465bac1eb0 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -531,6 +531,8 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); if (err) { inet->inet_saddr = inet->inet_rcv_saddr = 0; + if (sk->sk_prot->put_port) + sk->sk_prot->put_port(sk); goto out_release_sock; } } diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index e540b0dcf085..0e56df3a45e2 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -994,6 +994,7 @@ struct proto ping_prot = { .hash = ping_hash, .unhash = ping_unhash, .get_port = ping_get_port, + .put_port = ping_unhash, .obj_size = sizeof(struct inet_sock), }; EXPORT_SYMBOL(ping_prot); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index ac10e4cdd8d0..9861786b8336 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3076,6 +3076,7 @@ struct proto tcp_prot = { .hash = inet_hash, .unhash = inet_unhash, .get_port = inet_csk_get_port, + .put_port = inet_put_port, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = tcp_bpf_update_proto, #endif diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 7b18a6f42f18..c2a4411d2b04 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2927,6 +2927,7 @@ struct proto udp_prot = { .unhash = udp_lib_unhash, .rehash = udp_v4_rehash, .get_port = udp_v4_get_port, + .put_port = udp_lib_unhash, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = udp_bpf_update_proto, #endif diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index d1636425654e..8fe7900f1949 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -413,6 +413,8 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, if (err) { sk->sk_ipv6only = saved_ipv6only; inet_reset_saddr(sk); + if (sk->sk_prot->put_port) + sk->sk_prot->put_port(sk); goto out; } } diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index 6ac88fe24a8e..9256f6ba87ef 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -177,6 +177,7 @@ struct proto pingv6_prot = { .hash = ping_hash, .unhash = ping_unhash, .get_port = ping_get_port, + .put_port = ping_unhash, .obj_size = sizeof(struct raw6_sock), }; EXPORT_SYMBOL_GPL(pingv6_prot); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 1ac243d18c2b..075ee8a2df3b 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2181,6 +2181,7 @@ struct proto tcpv6_prot = { .hash = inet6_hash, .unhash = inet_unhash, .get_port = inet_csk_get_port, + .put_port = inet_put_port, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = tcp_bpf_update_proto, #endif diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 1accc06abc54..90718a924ca8 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1732,6 +1732,7 @@ struct proto udpv6_prot = { .unhash = udp_lib_unhash, .rehash = udp_v6_rehash, .get_port = udp_v6_get_port, + .put_port = udp_lib_unhash, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = udp_bpf_update_proto, #endif From patchwork Wed Jan 5 13:18:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 530263 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C5F7C433FE for ; Wed, 5 Jan 2022 13:21:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240258AbiAENVJ (ORCPT ); Wed, 5 Jan 2022 08:21:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240256AbiAENVG (ORCPT ); Wed, 5 Jan 2022 08:21:06 -0500 Received: from mail-pj1-x1042.google.com (mail-pj1-x1042.google.com [IPv6:2607:f8b0:4864:20::1042]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBA7CC061785; Wed, 5 Jan 2022 05:21:05 -0800 (PST) Received: by mail-pj1-x1042.google.com with SMTP id o63-20020a17090a0a4500b001b1c2db8145so3897386pjo.5; Wed, 05 Jan 2022 05:21:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=tjEyxmzWv+vv0x7VIz02gdNHRKgdP8+rFV7YB5P7KbE=; b=mYk+y+w4AIW+78UWSIucnzC0QUFLIoQVQJtglOo4dUvbyn7WGpNXu4AYbLpKdeKB/r GyUeFIRJCeQu5WNC2Sip5GyQoxJ9LZj1IWJVss0jakFQPOlEsCxwKHiORqyTSSWTCoOa 9wVL6m4rhdGozZGLjmy+/36zyvQUzruwKEE5NICffhEOareoB6KQfPc6sSw8+3/C6YYN 6/eSKH/X+7YXYcX6f1NqvYPplZ2LkdOrqZDjvQzxTCpXR1GJoY2SNt2dALSJOsWzyu4i TdkzOB/FrmQ0bbna2/0IJ/MOAxRuDl37aSs2H1yQHVbTRxNINddT1SVhWDbfEMTqLCIX DghA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=tjEyxmzWv+vv0x7VIz02gdNHRKgdP8+rFV7YB5P7KbE=; b=pk0LHfoRfePWcSYdIg9lVUNO75N3ftHb1JAN+o/GwiHm+32qFWjMJB7KW2ROC339K9 rWdlF/IUOKxebvATTFe7lVyXFyZ2bOHHKBVuHMKPubnaGHpv3Evrtr+DS3VmkTTXxR31 Ze5sZqJTOlriAyH7tQ8dQqgxySM+Es4Ups2qgAi5aZ/8YsX38/DIwtlIU/YyBJaWKjf/ Psm356aH2qjUrVLIfJYDZvORm7097h+vB00pTkPxmdfnTbs6RopqliK33xjxSuC2C/k7 6t4+n9j+Iu5pnIQh7rF78bJooPnSIsoqmrdJvUnuNyMJcLpiA1ALacgt+YSrrFGtb0CR QJJg== X-Gm-Message-State: AOAM532a5Or7HHygROjGOgheQMoJ8uNp/B148Z6SRFWjbIWcCLzRFR8S blpVzXkTcUodUhlWr6h8MAs= X-Google-Smtp-Source: ABdhPJyR/iNoetr6xBbPlII+t3j2e5I/ciGMz1YraVh53zGGVh+Zs9aZWa5Ect+Cb+5ukiLEevOZwQ== X-Received: by 2002:a17:902:bd86:b0:149:5e5e:3857 with SMTP id q6-20020a170902bd8600b001495e5e3857mr49979581pls.36.1641388865442; Wed, 05 Jan 2022 05:21:05 -0800 (PST) Received: from localhost.localdomain ([43.132.141.9]) by smtp.gmail.com with ESMTPSA id q17sm16227771pfj.119.2022.01.05.05.21.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jan 2022 05:21:05 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org, daniel@iogearbox.net Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, edumazet@google.com, shuah@kernel.org, ast@kernel.org, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, bpf@vger.kernel.org, Menglong Dong Subject: [PATCH v3 net-next 2/2] bpf: selftests: add bind retry for post_bind{4, 6} Date: Wed, 5 Jan 2022 21:18:49 +0800 Message-Id: <20220105131849.2559506-3-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220105131849.2559506-1-imagedong@tencent.com> References: <20220105131849.2559506-1-imagedong@tencent.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Menglong Dong With previous patch, kernel is able to 'put_port' after sys_bind() fails. Add the test for that case: rebind another port after sys_bind() fails. If the bind success, it means previous bind operation is already undoed. Signed-off-by: Menglong Dong --- tools/testing/selftests/bpf/test_sock.c | 166 +++++++++++++++++++++--- 1 file changed, 146 insertions(+), 20 deletions(-) diff --git a/tools/testing/selftests/bpf/test_sock.c b/tools/testing/selftests/bpf/test_sock.c index e8edd3dd3ec2..68525d68d4e5 100644 --- a/tools/testing/selftests/bpf/test_sock.c +++ b/tools/testing/selftests/bpf/test_sock.c @@ -35,12 +35,15 @@ struct sock_test { /* Endpoint to bind() to */ const char *ip; unsigned short port; + unsigned short port_retry; /* Expected test result */ enum { LOAD_REJECT, ATTACH_REJECT, BIND_REJECT, SUCCESS, + RETRY_SUCCESS, + RETRY_REJECT } result; }; @@ -60,6 +63,7 @@ static struct sock_test tests[] = { 0, NULL, 0, + 0, LOAD_REJECT, }, { @@ -77,6 +81,7 @@ static struct sock_test tests[] = { 0, NULL, 0, + 0, LOAD_REJECT, }, { @@ -94,6 +99,7 @@ static struct sock_test tests[] = { 0, NULL, 0, + 0, LOAD_REJECT, }, { @@ -111,6 +117,7 @@ static struct sock_test tests[] = { 0, NULL, 0, + 0, LOAD_REJECT, }, { @@ -125,6 +132,7 @@ static struct sock_test tests[] = { SOCK_STREAM, "127.0.0.1", 8097, + 0, SUCCESS, }, { @@ -139,6 +147,7 @@ static struct sock_test tests[] = { SOCK_STREAM, "127.0.0.1", 8097, + 0, SUCCESS, }, { @@ -153,6 +162,7 @@ static struct sock_test tests[] = { 0, NULL, 0, + 0, ATTACH_REJECT, }, { @@ -167,6 +177,7 @@ static struct sock_test tests[] = { 0, NULL, 0, + 0, ATTACH_REJECT, }, { @@ -181,6 +192,7 @@ static struct sock_test tests[] = { 0, NULL, 0, + 0, ATTACH_REJECT, }, { @@ -195,6 +207,7 @@ static struct sock_test tests[] = { 0, NULL, 0, + 0, ATTACH_REJECT, }, { @@ -209,6 +222,7 @@ static struct sock_test tests[] = { SOCK_STREAM, "0.0.0.0", 0, + 0, BIND_REJECT, }, { @@ -223,6 +237,7 @@ static struct sock_test tests[] = { SOCK_STREAM, "::", 0, + 0, BIND_REJECT, }, { @@ -253,6 +268,7 @@ static struct sock_test tests[] = { SOCK_STREAM, "::1", 8193, + 0, BIND_REJECT, }, { @@ -283,8 +299,102 @@ static struct sock_test tests[] = { SOCK_STREAM, "127.0.0.1", 4098, + 0, SUCCESS, }, + { + "bind4 deny specific IP & port of TCP, and retry", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + + /* if (ip == expected && port == expected) */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock, src_ip4)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, + __bpf_constant_ntohl(0x7F000001), 4), + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock, src_port)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2), + + /* return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_A(1), + + /* else return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + BPF_CGROUP_INET4_POST_BIND, + BPF_CGROUP_INET4_POST_BIND, + AF_INET, + SOCK_STREAM, + "127.0.0.1", + 4098, + 5000, + RETRY_SUCCESS, + }, + { + "bind4 deny specific IP & port of UDP, and retry", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + + /* if (ip == expected && port == expected) */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock, src_ip4)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, + __bpf_constant_ntohl(0x7F000001), 4), + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock, src_port)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2), + + /* return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_A(1), + + /* else return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + BPF_CGROUP_INET4_POST_BIND, + BPF_CGROUP_INET4_POST_BIND, + AF_INET, + SOCK_DGRAM, + "127.0.0.1", + 4098, + 5000, + RETRY_SUCCESS, + }, + { + "bind6 deny specific IP & port, and retry", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + + /* if (ip == expected && port == expected) */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock, src_ip6[3])), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, + __bpf_constant_ntohl(0x00000001), 4), + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock, src_port)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2), + + /* return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_A(1), + + /* else return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + BPF_CGROUP_INET6_POST_BIND, + BPF_CGROUP_INET6_POST_BIND, + AF_INET6, + SOCK_STREAM, + "::1", + 8193, + 9000, + RETRY_SUCCESS, + }, { "bind4 allow all", .insns = { @@ -297,6 +407,7 @@ static struct sock_test tests[] = { SOCK_STREAM, "0.0.0.0", 0, + 0, SUCCESS, }, { @@ -311,6 +422,7 @@ static struct sock_test tests[] = { SOCK_STREAM, "::", 0, + 0, SUCCESS, }, }; @@ -351,14 +463,15 @@ static int attach_sock_prog(int cgfd, int progfd, return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE); } -static int bind_sock(int domain, int type, const char *ip, unsigned short port) +static int bind_sock(int domain, int type, const char *ip, + unsigned short port, unsigned short port_retry) { struct sockaddr_storage addr; struct sockaddr_in6 *addr6; struct sockaddr_in *addr4; int sockfd = -1; socklen_t len; - int err = 0; + int res = SUCCESS; sockfd = socket(domain, type, 0); if (sockfd < 0) @@ -384,21 +497,44 @@ static int bind_sock(int domain, int type, const char *ip, unsigned short port) goto err; } - if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) - goto err; + if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) { + /* sys_bind() may fail for different reasons, errno has to be + * checked to confirm that BPF program rejected it. + */ + if (errno != EPERM) + goto err; + if (port_retry) + goto retry; + res = BIND_REJECT; + goto out; + } + goto out; +retry: + if (domain == AF_INET) + addr4->sin_port = htons(port_retry); + else + addr6->sin6_port = htons(port_retry); + if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) { + if (errno != EPERM) + goto err; + res = RETRY_REJECT; + } else { + res = RETRY_SUCCESS; + } goto out; err: - err = -1; + res = -1; out: close(sockfd); - return err; + return res; } static int run_test_case(int cgfd, const struct sock_test *test) { int progfd = -1; int err = 0; + int res; printf("Test case: %s .. ", test->descr); progfd = load_sock_prog(test->insns, test->expected_attach_type); @@ -416,21 +552,11 @@ static int run_test_case(int cgfd, const struct sock_test *test) goto err; } - if (bind_sock(test->domain, test->type, test->ip, test->port) == -1) { - /* sys_bind() may fail for different reasons, errno has to be - * checked to confirm that BPF program rejected it. - */ - if (test->result == BIND_REJECT && errno == EPERM) - goto out; - else - goto err; - } - + res = bind_sock(test->domain, test->type, test->ip, test->port, + test->port_retry); + if (res > 0 && test->result == res) + goto out; - if (test->result != SUCCESS) - goto err; - - goto out; err: err = -1; out: