bpf: Add setsockopt helper function to bpf (8c4b4c7e) · Commits · 戴 / test

include/uapi/linux/bpf.h

+13 −1

Original line number	Diff line number	Diff line
		@@ -520,6 +520,17 @@ union bpf_attr {
		* Set full skb->hash.
		* @skb: pointer to skb
		* @hash: hash to set
		*
		* int bpf_setsockopt(bpf_socket, 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
		* @bpf_socket: 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), \
		@@ -570,7 +581,8 @@ union bpf_attr {
		FN(probe_read_str), \
		FN(get_socket_cookie), \
		FN(get_socket_uid), \
		FN(set_hash),
		FN(set_hash), \
		FN(setsockopt),

		/* integer value in 'imm' field of BPF_CALL instruction selects which helper
		* function eBPF program intends to call

net/core/filter.c

+78 −1

Original line number	Diff line number	Diff line
		@@ -54,6 +54,7 @@
		#include <net/dst.h>
		#include <net/sock_reuseport.h>
		#include <net/busy_poll.h>
		#include <net/tcp.h>

		/**
		* sk_filter_trim_cap - run a packet through a socket filter
		@@ -2672,6 +2673,71 @@ 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)
		{
		struct sock *sk = bpf_sock->sk;
		int ret = 0;
		int val;

		if (!sk_fullsock(sk))
		return -EINVAL;

		if (level == SOL_SOCKET) {
		if (optlen != sizeof(int))
		return -EINVAL;
		val = ((int )optval);

		/* Only some socketops are supported */
		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 &&
		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,
		};

		static const struct bpf_func_proto *
		bpf_base_func_proto(enum bpf_func_id func_id)
		{
		@@ -2822,6 +2888,17 @@ lwt_inout_func_proto(enum bpf_func_id func_id)
		}
		}

		static const struct bpf_func_proto *
		sock_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)
		{
		@@ -3591,7 +3668,7 @@ const struct bpf_verifier_ops cg_sock_prog_ops = {
		};

		const struct bpf_verifier_ops sock_ops_prog_ops = {
		.get_func_proto = bpf_base_func_proto,
		.get_func_proto = sock_ops_func_proto,
		.is_valid_access = sock_ops_is_valid_access,
		.convert_ctx_access = sock_ops_convert_ctx_access,
		};

samples/bpf/bpf_helpers.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -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

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