From patchwork Thu Apr 30 23:31:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 220112 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=DKIMWL_WL_MED, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46D30C4724C for ; Thu, 30 Apr 2020 23:31:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24704208DB for ; Thu, 30 Apr 2020 23:31:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="hTeDcqou" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726598AbgD3Xb4 (ORCPT ); Thu, 30 Apr 2020 19:31:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726435AbgD3Xb4 (ORCPT ); Thu, 30 Apr 2020 19:31:56 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7C21C035495 for ; Thu, 30 Apr 2020 16:31:54 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id s8so9823644ybj.9 for ; Thu, 30 Apr 2020 16:31:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=P/ZkVzy8srGzpdc1wH5VQEZkZ6K0ju1bsjqWwmQKNss=; b=hTeDcqouG+d0dbaPopxWRL9v5H+pDW896PfOfBdGYdbNP9Hi+DVaN/xECgJXq2UzDK y5TLjKliiu/s7JhzrAmXuMJ8uiRIaQVgKvdr+W087d/8N73VSVwIuGCyfPfu35jis87k bMrHKNhOjE0AB1tbRXOGBWKqdWhGoflMQWCLvUUnud2qu16ziDXNolkVAvdZhvEEnZgS wcg5IL6M3puCOSgqAHuBXoe4B7/HRc1UuI+U/itG4M18mUV7HiAXJbXS0Y3zFVb5mc/9 D18TsyTGU7TXcJ8IVU6rYOxsAQHy1TNWpCmnf42JgCb+X5eOl07XOc34VjcZRHDZsMm1 f6NA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=P/ZkVzy8srGzpdc1wH5VQEZkZ6K0ju1bsjqWwmQKNss=; b=BUIPcDAFQEZ3DQsfiZEjrwXWuppFHvSvHN5XILAzOxsS96pAiAGuK1Lz51VXFaUZbs Hrzloure/0MAqgYIOR1kMwYPrhrvlPGNh00MA36i/K1s2H/RHACFfh7gmFzPU3yBGLPP Gtt+x631q3i0KbIKnIgSHlcJ0HDAuUpcVzgReec+2XVApxVS3zB84b/4zZC89OIiAKeB Q+Ji9cE43oVDBlyY6H0df3F/IU/+mu3rjl7nJNS8ByXbSV/ALk9xTiSrenkTjl7D1mPP 7GZjcdErWZXz3mUVDz9Qz6saU3yzau97AD8vJGTnRsH5R9lc9vEEsTdmN6eecNZnh5Fw D9hA== X-Gm-Message-State: AGi0PubUesy0EEtXxkeWL81VWWaqbZkPaN/OA4C5om/eBtOxC7nFv3Cr Y4ZU3r9Pq2ABbIAjfwsGzbMe8MhYD2RsRZID8rbh/XbnMsessuKKC7r4MAlukwijLvWrpg6mvSp 25oyo5fJisrQmR/ed/+PJ33HjJpQ3sRB4+nyk4YpiDxZ1YUfTJ0La/A== X-Google-Smtp-Source: APiQypJDNBJ855fNpoNoY05VbLvgyoLzn31gX6fJ9xeOZgattsasn8f/HoyVf1dnFhAofOhu+j24ppo= X-Received: by 2002:a25:448:: with SMTP id 69mr2151763ybe.187.1588289513703; Thu, 30 Apr 2020 16:31:53 -0700 (PDT) Date: Thu, 30 Apr 2020 16:31:52 -0700 Message-Id: <20200430233152.199403-1-sdf@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.26.2.526.g744177e7f7-goog Subject: [PATCH bpf-next v3] bpf: bpf_{g, s}etsockopt for struct bpf_sock_addr From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev , John Fastabend , Martin KaFai Lau Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Currently, bpf_getsockopt and bpf_setsockopt helpers operate on the 'struct bpf_sock_ops' context in BPF_PROG_TYPE_SOCK_OPS program. Let's generalize them and make them available for 'struct bpf_sock_addr'. That way, in the future, we can allow those helpers in more places. As an example, let's expose those 'struct bpf_sock_addr' based helpers to BPF_CGROUP_INET{4,6}_CONNECT hooks. That way we can override CC before the connection is made. v3: * Expose custom helpers for bpf_sock_addr context instead of doing generic bpf_sock argument (as suggested by Daniel). Even with try_socket_lock that doesn't sleep we have a problem where context sk is already locked and socket lock is non-nestable. v2: * s/BPF_PROG_TYPE_CGROUP_SOCKOPT/BPF_PROG_TYPE_SOCK_OPS/ Cc: John Fastabend Cc: Martin KaFai Lau Signed-off-by: Stanislav Fomichev --- include/uapi/linux/bpf.h | 14 ++- net/core/filter.c | 118 ++++++++++++++---- tools/include/uapi/linux/bpf.h | 14 ++- tools/testing/selftests/bpf/config | 1 + .../selftests/bpf/progs/connect4_prog.c | 46 +++++++ 5 files changed, 166 insertions(+), 27 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 4a6c47f3febe..761db1aed891 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1564,7 +1564,7 @@ union bpf_attr { * Return * 0 * - * int bpf_setsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, void *optval, int optlen) + * int bpf_setsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen) * Description * Emulate a call to **setsockopt()** on the socket associated to * *bpf_socket*, which must be a full socket. The *level* at @@ -1572,6 +1572,11 @@ union bpf_attr { * must be specified, see **setsockopt(2)** for more information. * The option value of length *optlen* is pointed by *optval*. * + * *bpf_socket* should be one of the following: + * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. + * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT** + * and **BPF_CGROUP_INET6_CONNECT**. + * * This helper actually implements a subset of **setsockopt()**. * It supports the following *level*\ s: * @@ -1766,7 +1771,7 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * - * int bpf_getsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, void *optval, int optlen) + * int bpf_getsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen) * Description * Emulate a call to **getsockopt()** on the socket associated to * *bpf_socket*, which must be a full socket. The *level* at @@ -1775,6 +1780,11 @@ union bpf_attr { * The retrieved value is stored in the structure pointed by * *opval* and of length *optlen*. * + * *bpf_socket* should be one of the following: + * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. + * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT** + * and **BPF_CGROUP_INET6_CONNECT**. + * * This helper actually implements a subset of **getsockopt()**. * It supports the following *level*\ s: * diff --git a/net/core/filter.c b/net/core/filter.c index da3b7a72c37c..437bb74dd9a9 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4194,16 +4194,19 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = { .arg1_type = ARG_PTR_TO_CTX, }; -BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, - int, level, int, optname, char *, optval, int, optlen) +#define SOCKOPT_CC_REINIT (1 << 0) + +static int _bpf_setsockopt(struct sock *sk, int level, int optname, + char *optval, int optlen, u32 flags) { - struct sock *sk = bpf_sock->sk; int ret = 0; int val; if (!sk_fullsock(sk)) return -EINVAL; + sock_owned_by_me(sk); + if (level == SOL_SOCKET) { if (optlen != sizeof(int)) return -EINVAL; @@ -4298,7 +4301,7 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, sk->sk_prot->setsockopt == tcp_setsockopt) { if (optname == TCP_CONGESTION) { char name[TCP_CA_NAME_MAX]; - bool reinit = bpf_sock->op > BPF_SOCK_OPS_NEEDS_ECN; + bool reinit = flags & SOCKOPT_CC_REINIT; strncpy(name, optval, min_t(long, optlen, TCP_CA_NAME_MAX-1)); @@ -4345,24 +4348,14 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, return ret; } -static const struct bpf_func_proto bpf_setsockopt_proto = { - .func = bpf_setsockopt, - .gpl_only = false, - .ret_type = RET_INTEGER, - .arg1_type = ARG_PTR_TO_CTX, - .arg2_type = ARG_ANYTHING, - .arg3_type = ARG_ANYTHING, - .arg4_type = ARG_PTR_TO_MEM, - .arg5_type = ARG_CONST_SIZE, -}; - -BPF_CALL_5(bpf_getsockopt, struct bpf_sock_ops_kern *, bpf_sock, - int, level, int, optname, char *, optval, int, optlen) +static int _bpf_getsockopt(struct sock *sk, int level, int optname, + char *optval, int optlen) { - struct sock *sk = bpf_sock->sk; - if (!sk_fullsock(sk)) goto err_clear; + + sock_owned_by_me(sk); + #ifdef CONFIG_INET if (level == SOL_TCP && sk->sk_prot->getsockopt == tcp_getsockopt) { struct inet_connection_sock *icsk; @@ -4428,8 +4421,71 @@ BPF_CALL_5(bpf_getsockopt, struct bpf_sock_ops_kern *, bpf_sock, return -EINVAL; } -static const struct bpf_func_proto bpf_getsockopt_proto = { - .func = bpf_getsockopt, +BPF_CALL_5(bpf_sock_addr_setsockopt, struct bpf_sock_addr_kern *, ctx, + int, level, int, optname, char *, optval, int, optlen) +{ + u32 flags = 0; + return _bpf_setsockopt(ctx->sk, level, optname, optval, optlen, + flags); +} + +static const struct bpf_func_proto bpf_sock_addr_setsockopt_proto = { + .func = bpf_sock_addr_setsockopt, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_MEM, + .arg5_type = ARG_CONST_SIZE, +}; + +BPF_CALL_5(bpf_sock_addr_getsockopt, struct bpf_sock_addr_kern *, ctx, + int, level, int, optname, char *, optval, int, optlen) +{ + return _bpf_getsockopt(ctx->sk, level, optname, optval, optlen); +} + +static const struct bpf_func_proto bpf_sock_addr_getsockopt_proto = { + .func = bpf_sock_addr_getsockopt, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_UNINIT_MEM, + .arg5_type = ARG_CONST_SIZE, +}; + +BPF_CALL_5(bpf_sock_ops_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, + int, level, int, optname, char *, optval, int, optlen) +{ + u32 flags = 0; + if (bpf_sock->op > BPF_SOCK_OPS_NEEDS_ECN) + flags |= SOCKOPT_CC_REINIT; + return _bpf_setsockopt(bpf_sock->sk, level, optname, optval, optlen, + flags); +} + +static const struct bpf_func_proto bpf_sock_ops_setsockopt_proto = { + .func = bpf_sock_ops_setsockopt, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_MEM, + .arg5_type = ARG_CONST_SIZE, +}; + +BPF_CALL_5(bpf_sock_ops_getsockopt, struct bpf_sock_ops_kern *, bpf_sock, + int, level, int, optname, char *, optval, int, optlen) +{ + return _bpf_getsockopt(bpf_sock->sk, level, optname, optval, optlen); +} + +static const struct bpf_func_proto bpf_sock_ops_getsockopt_proto = { + .func = bpf_sock_ops_getsockopt, .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_CTX, @@ -6043,6 +6099,22 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_sk_storage_get_proto; case BPF_FUNC_sk_storage_delete: return &bpf_sk_storage_delete_proto; + case BPF_FUNC_setsockopt: + switch (prog->expected_attach_type) { + case BPF_CGROUP_INET4_CONNECT: + case BPF_CGROUP_INET6_CONNECT: + return &bpf_sock_addr_setsockopt_proto; + default: + return NULL; + } + case BPF_FUNC_getsockopt: + switch (prog->expected_attach_type) { + case BPF_CGROUP_INET4_CONNECT: + case BPF_CGROUP_INET6_CONNECT: + return &bpf_sock_addr_getsockopt_proto; + default: + return NULL; + } default: return bpf_base_func_proto(func_id); } @@ -6261,9 +6333,9 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { switch (func_id) { case BPF_FUNC_setsockopt: - return &bpf_setsockopt_proto; + return &bpf_sock_ops_setsockopt_proto; case BPF_FUNC_getsockopt: - return &bpf_getsockopt_proto; + return &bpf_sock_ops_getsockopt_proto; case BPF_FUNC_sock_ops_cb_flags_set: return &bpf_sock_ops_cb_flags_set_proto; case BPF_FUNC_sock_map_update: diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 4a6c47f3febe..761db1aed891 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1564,7 +1564,7 @@ union bpf_attr { * Return * 0 * - * int bpf_setsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, void *optval, int optlen) + * int bpf_setsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen) * Description * Emulate a call to **setsockopt()** on the socket associated to * *bpf_socket*, which must be a full socket. The *level* at @@ -1572,6 +1572,11 @@ union bpf_attr { * must be specified, see **setsockopt(2)** for more information. * The option value of length *optlen* is pointed by *optval*. * + * *bpf_socket* should be one of the following: + * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. + * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT** + * and **BPF_CGROUP_INET6_CONNECT**. + * * This helper actually implements a subset of **setsockopt()**. * It supports the following *level*\ s: * @@ -1766,7 +1771,7 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * - * int bpf_getsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, void *optval, int optlen) + * int bpf_getsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen) * Description * Emulate a call to **getsockopt()** on the socket associated to * *bpf_socket*, which must be a full socket. The *level* at @@ -1775,6 +1780,11 @@ union bpf_attr { * The retrieved value is stored in the structure pointed by * *opval* and of length *optlen*. * + * *bpf_socket* should be one of the following: + * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. + * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT** + * and **BPF_CGROUP_INET6_CONNECT**. + * * This helper actually implements a subset of **getsockopt()**. * It supports the following *level*\ s: * diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index 60e3ae5d4e48..6e5b94c036ca 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -37,3 +37,4 @@ CONFIG_IPV6_SIT=m CONFIG_BPF_JIT=y CONFIG_BPF_LSM=y CONFIG_SECURITY=y +CONFIG_TCP_CONG_DCTCP=y diff --git a/tools/testing/selftests/bpf/progs/connect4_prog.c b/tools/testing/selftests/bpf/progs/connect4_prog.c index ad3c498a8150..972918cd2d7f 100644 --- a/tools/testing/selftests/bpf/progs/connect4_prog.c +++ b/tools/testing/selftests/bpf/progs/connect4_prog.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include @@ -16,6 +17,10 @@ #define DST_REWRITE_IP4 0x7f000001U #define DST_REWRITE_PORT4 4444 +#ifndef TCP_CA_NAME_MAX +#define TCP_CA_NAME_MAX 16 +#endif + int _version SEC("version") = 1; __attribute__ ((noinline)) @@ -33,6 +38,43 @@ int do_bind(struct bpf_sock_addr *ctx) return 1; } +static __inline int verify_cc(struct bpf_sock_addr *ctx, + char expected[TCP_CA_NAME_MAX]) +{ + char buf[TCP_CA_NAME_MAX]; + int i; + + if (bpf_getsockopt(ctx, SOL_TCP, TCP_CONGESTION, &buf, sizeof(buf))) + return 1; + + for (i = 0; i < TCP_CA_NAME_MAX; i++) { + if (buf[i] != expected[i]) + return 1; + if (buf[i] == 0) + break; + } + + return 0; +} + +static __inline int set_cc(struct bpf_sock_addr *ctx) +{ + char dctcp[TCP_CA_NAME_MAX] = "dctcp"; + char cubic[TCP_CA_NAME_MAX] = "cubic"; + + if (bpf_setsockopt(ctx, SOL_TCP, TCP_CONGESTION, &dctcp, sizeof(dctcp))) + return 1; + if (verify_cc(ctx, dctcp)) + return 1; + + if (bpf_setsockopt(ctx, SOL_TCP, TCP_CONGESTION, &cubic, sizeof(cubic))) + return 1; + if (verify_cc(ctx, cubic)) + return 1; + + return 0; +} + SEC("cgroup/connect4") int connect_v4_prog(struct bpf_sock_addr *ctx) { @@ -66,6 +108,10 @@ int connect_v4_prog(struct bpf_sock_addr *ctx) bpf_sk_release(sk); + /* Rewrite congestion control. */ + if (ctx->type == SOCK_STREAM && set_cc(ctx)) + return 0; + /* Rewrite destination. */ ctx->user_ip4 = bpf_htonl(DST_REWRITE_IP4); ctx->user_port = bpf_htons(DST_REWRITE_PORT4);