bpf: Add setsockopt helper function to bpf
Added support for calling a subset of socket setsockopts from
BPF_PROG_TYPE_SOCK_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 <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 94d7ded..dd43b22 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -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