From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lawrence Brakmo Subject: [RFC PATCH net-next 07/15] bpf: Add setsockopt helper function to bpf Date: Tue, 13 Jun 2017 10:59:56 -0700 Message-ID: <20170613180004.3008403-8-brakmo@fb.com> References: <20170613180004.3008403-1-brakmo@fb.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Kernel Team , Blake Matheny , Alexei Starovoitov , Daniel Borkmann , David Ahern To: netdev Return-path: Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:32995 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752489AbdFMSAJ (ORCPT ); Tue, 13 Jun 2017 14:00:09 -0400 Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v5DHxZeY008176 for ; Tue, 13 Jun 2017 11:00:09 -0700 Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2b2m6109tv-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Tue, 13 Jun 2017 11:00:09 -0700 Received: from facebook.com (2401:db00:11:d025:face:0:13:0) by mx-out.facebook.com (10.102.107.97) with ESMTP id 232f1462506211e79a800002c99331b0-78d3a8f0 for ; Tue, 13 Jun 2017 11:00:08 -0700 In-Reply-To: <20170613180004.3008403-1-brakmo@fb.com> Sender: netdev-owner@vger.kernel.org List-ID: Added support for calling a subset of socket setsockopts from BPF_PROG_TYPE_SOCKET_OPS programs. The code was duplicated rather than making the changes to call the socket setsockopt function because the changes required would have been larger. The ops supported are: SO_RCVBUF SO_SNDBUF SO_MAX_PACING_RATE SO_PRIORITY SO_RCVLOWAT SO_MARK Signed-off-by: Lawrence Brakmo --- include/uapi/linux/bpf.h | 14 ++++++++- net/core/filter.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++- samples/bpf/bpf_helpers.h | 3 ++ 3 files changed, 92 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index b2af839..e229d61 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -495,6 +495,17 @@ union bpf_attr { * Get the owner uid of the socket stored inside sk_buff. * @skb: pointer to skb * Return: uid of the socket owner on success or overflowuid if failed. + * + * int bpf_setsockopt(sk, level, optname, optval, optlen) + * Calls setsockopt. Not all opts are available, only those with + * integer optvals plus TCP_CONGESTION. + * Supported levels: SOL_SOCKET and IPROTO_TCP + * @sk: pointer to bpf_socket + * @level: SOL_SOCKET or IPROTO_TCP + * @optname: option name + * @optval: pointer to option value + * @optlen: length of optval in byes + * Return: 0 or negative error */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -544,7 +555,8 @@ union bpf_attr { FN(xdp_adjust_head), \ FN(probe_read_str), \ FN(get_socket_cookie), \ - FN(get_socket_uid), + FN(get_socket_uid), \ + FN(setsockopt), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/net/core/filter.c b/net/core/filter.c index 7b61690..6bc8d57 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -54,6 +54,7 @@ #include #include #include +#include /** * sk_filter_trim_cap - run a packet through a socket filter @@ -2653,6 +2654,69 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_5(bpf_setsockopt, struct bpf_socket_ops_kern *, bpf_socket, + int, level, int, optname, char *, optval, int, optlen) +{ + int val; + int ret = 0; + struct sock *sk = bpf_socket->sk; + + if (bpf_socket->is_req_sock) + return -EINVAL; + + if (level == SOL_SOCKET) { + // Only some socketops are supported + val = *((int *)optval); + + switch (optname) { + case SO_RCVBUF: + sk->sk_userlocks |= SOCK_RCVBUF_LOCK; + sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF); + break; + case SO_SNDBUF: + sk->sk_userlocks |= SOCK_SNDBUF_LOCK; + sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF); + break; + case SO_MAX_PACING_RATE: + sk->sk_max_pacing_rate = val; + sk->sk_pacing_rate = min(sk->sk_pacing_rate, + sk->sk_max_pacing_rate); + break; + case SO_PRIORITY: + sk->sk_priority = val; + break; + case SO_RCVLOWAT: + if (val < 0) + val = INT_MAX; + sk->sk_rcvlowat = val ? : 1; + break; + case SO_MARK: + sk->sk_mark = val; + break; + default: + ret = -EINVAL; + } + } else if (level == SOL_TCP && + bpf_socket->sk->sk_prot->setsockopt == tcp_setsockopt) { + // Place holder + ret = -EINVAL; + } else { + ret = -EINVAL; + } + return ret; +} + +static const struct bpf_func_proto bpf_setsockopt_proto = { + .func = bpf_setsockopt, + .gpl_only = true, + .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_OR_ZERO, +}; + static const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) { @@ -2808,6 +2872,17 @@ lwt_inout_func_proto(enum bpf_func_id func_id) } static const struct bpf_func_proto * + socket_ops_func_proto(enum bpf_func_id func_id) +{ + switch (func_id) { + case BPF_FUNC_setsockopt: + return &bpf_setsockopt_proto; + default: + return bpf_base_func_proto(func_id); + } +} + +static const struct bpf_func_proto * lwt_xmit_func_proto(enum bpf_func_id func_id) { switch (func_id) { @@ -3523,7 +3598,7 @@ const struct bpf_verifier_ops cg_sock_prog_ops = { }; const struct bpf_verifier_ops socket_ops_prog_ops = { - .get_func_proto = bpf_base_func_proto, + .get_func_proto = socket_ops_func_proto, .is_valid_access = socket_ops_is_valid_access, .convert_ctx_access = socket_ops_convert_ctx_access, }; diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h index 51e567b..d7514c0 100644 --- a/samples/bpf/bpf_helpers.h +++ b/samples/bpf/bpf_helpers.h @@ -60,6 +60,9 @@ static unsigned long long (*bpf_get_prandom_u32)(void) = (void *) BPF_FUNC_get_prandom_u32; static int (*bpf_xdp_adjust_head)(void *ctx, int offset) = (void *) BPF_FUNC_xdp_adjust_head; +static int (*bpf_setsockopt)(void *ctx, int level, int optname, void *optval, + int optlen) = + (void *) BPF_FUNC_setsockopt; /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions -- 2.9.3