diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1aca744c220f..f650346aaa1a 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -613,12 +613,22 @@ union bpf_attr { * 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 + * Supported levels: SOL_SOCKET and IPPROTO_TCP * @bpf_socket: pointer to bpf_socket - * @level: SOL_SOCKET or IPROTO_TCP + * @level: SOL_SOCKET or IPPROTO_TCP * @optname: option name * @optval: pointer to option value - * @optlen: length of optval in byes + * @optlen: length of optval in bytes + * Return: 0 or negative error + * + * int bpf_getsockopt(bpf_socket, level, optname, optval, optlen) + * Calls getsockopt. Not all opts are available. + * Supported levels: IPPROTO_TCP + * @bpf_socket: pointer to bpf_socket + * @level: IPPROTO_TCP + * @optname: option name + * @optval: pointer to option value + * @optlen: length of optval in bytes * Return: 0 or negative error * * int bpf_skb_adjust_room(skb, len_diff, mode, flags) @@ -721,7 +731,8 @@ union bpf_attr { FN(sock_map_update), \ FN(xdp_adjust_meta), \ FN(perf_event_read_value), \ - FN(perf_prog_read_value), + FN(perf_prog_read_value), \ + FN(getsockopt), /* 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 09e011f20291..ccf62f44140a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3273,7 +3273,7 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, static const struct bpf_func_proto bpf_setsockopt_proto = { .func = bpf_setsockopt, - .gpl_only = true, + .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_CTX, .arg2_type = ARG_ANYTHING, @@ -3282,6 +3282,48 @@ static const struct bpf_func_proto bpf_setsockopt_proto = { .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) +{ + struct sock *sk = bpf_sock->sk; + int ret = 0; + + if (!sk_fullsock(sk)) + goto err_clear; + +#ifdef CONFIG_INET + if (level == SOL_TCP && sk->sk_prot->getsockopt == tcp_getsockopt) { + if (optname == TCP_CONGESTION) { + struct inet_connection_sock *icsk = inet_csk(sk); + + if (!icsk->icsk_ca_ops || optlen <= 1) + goto err_clear; + strncpy(optval, icsk->icsk_ca_ops->name, optlen); + optval[optlen - 1] = 0; + } else { + goto err_clear; + } + } else { + goto err_clear; + } + return ret; +#endif +err_clear: + memset(optval, 0, optlen); + return -EINVAL; +} + +static const struct bpf_func_proto bpf_getsockopt_proto = { + .func = bpf_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, +}; + static const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) { @@ -3460,6 +3502,8 @@ static const struct bpf_func_proto * switch (func_id) { case BPF_FUNC_setsockopt: return &bpf_setsockopt_proto; + case BPF_FUNC_getsockopt: + return &bpf_getsockopt_proto; case BPF_FUNC_sock_map_update: return &bpf_sock_map_update_proto; default: diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index e25dbf6038cf..609514f74482 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -67,6 +67,9 @@ static int (*bpf_xdp_adjust_meta)(void *ctx, int offset) = static int (*bpf_setsockopt)(void *ctx, int level, int optname, void *optval, int optlen) = (void *) BPF_FUNC_setsockopt; +static int (*bpf_getsockopt)(void *ctx, int level, int optname, void *optval, + int optlen) = + (void *) BPF_FUNC_getsockopt; static int (*bpf_sk_redirect_map)(void *map, int key, int flags) = (void *) BPF_FUNC_sk_redirect_map; static int (*bpf_sock_map_update)(void *map, void *key, void *value,