bpf: Adding helper function bpf_getsockops

Adding support for helper function bpf_getsockops to socket_ops BPF
programs. This patch only supports TCP_CONGESTION.

Signed-off-by: Vlad Vysotsky <vlad@cs.ucla.edu>
Acked-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lawrence Brakmo 2017-10-20 11:05:40 -07:00 committed by David S. Miller
parent e6546ef6d8
commit cd86d1fd21
3 changed files with 63 additions and 5 deletions

View File

@ -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

View File

@ -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:

View File

@ -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,