Commit ded092cd authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller

bpf: add bpf_set_hash helper for tc progs

Allow for tc BPF programs to set a skb->hash, apart from clearing
and triggering a recalc that we have right now. It allows for BPF
to implement a custom hashing routine for skb_get_hash().
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 966789fb
...@@ -513,6 +513,11 @@ union bpf_attr { ...@@ -513,6 +513,11 @@ union bpf_attr {
* Get the owner uid of the socket stored inside sk_buff. * Get the owner uid of the socket stored inside sk_buff.
* @skb: pointer to skb * @skb: pointer to skb
* Return: uid of the socket owner on success or overflowuid if failed. * Return: uid of the socket owner on success or overflowuid if failed.
*
* u32 bpf_set_hash(skb, hash)
* Set full skb->hash.
* @skb: pointer to skb
* @hash: hash to set
*/ */
#define __BPF_FUNC_MAPPER(FN) \ #define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \ FN(unspec), \
...@@ -562,7 +567,8 @@ union bpf_attr { ...@@ -562,7 +567,8 @@ union bpf_attr {
FN(xdp_adjust_head), \ FN(xdp_adjust_head), \
FN(probe_read_str), \ FN(probe_read_str), \
FN(get_socket_cookie), \ FN(get_socket_cookie), \
FN(get_socket_uid), FN(get_socket_uid), \
FN(set_hash),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper /* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call * function eBPF program intends to call
......
...@@ -1874,6 +1874,24 @@ static const struct bpf_func_proto bpf_set_hash_invalid_proto = { ...@@ -1874,6 +1874,24 @@ static const struct bpf_func_proto bpf_set_hash_invalid_proto = {
.arg1_type = ARG_PTR_TO_CTX, .arg1_type = ARG_PTR_TO_CTX,
}; };
BPF_CALL_2(bpf_set_hash, struct sk_buff *, skb, u32, hash)
{
/* Set user specified hash as L4(+), so that it gets returned
* on skb_get_hash() call unless BPF prog later on triggers a
* skb_clear_hash().
*/
__skb_set_sw_hash(skb, hash, true);
return 0;
}
static const struct bpf_func_proto bpf_set_hash_proto = {
.func = bpf_set_hash,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_skb_vlan_push, struct sk_buff *, skb, __be16, vlan_proto, BPF_CALL_3(bpf_skb_vlan_push, struct sk_buff *, skb, __be16, vlan_proto,
u16, vlan_tci) u16, vlan_tci)
{ {
...@@ -2744,6 +2762,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id) ...@@ -2744,6 +2762,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id)
return &bpf_get_hash_recalc_proto; return &bpf_get_hash_recalc_proto;
case BPF_FUNC_set_hash_invalid: case BPF_FUNC_set_hash_invalid:
return &bpf_set_hash_invalid_proto; return &bpf_set_hash_invalid_proto;
case BPF_FUNC_set_hash:
return &bpf_set_hash_proto;
case BPF_FUNC_perf_event_output: case BPF_FUNC_perf_event_output:
return &bpf_skb_event_output_proto; return &bpf_skb_event_output_proto;
case BPF_FUNC_get_smp_processor_id: case BPF_FUNC_get_smp_processor_id:
......
...@@ -513,6 +513,11 @@ union bpf_attr { ...@@ -513,6 +513,11 @@ union bpf_attr {
* Get the owner uid of the socket stored inside sk_buff. * Get the owner uid of the socket stored inside sk_buff.
* @skb: pointer to skb * @skb: pointer to skb
* Return: uid of the socket owner on success or overflowuid if failed. * Return: uid of the socket owner on success or overflowuid if failed.
*
* u32 bpf_set_hash(skb, hash)
* Set full skb->hash.
* @skb: pointer to skb
* @hash: hash to set
*/ */
#define __BPF_FUNC_MAPPER(FN) \ #define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \ FN(unspec), \
...@@ -562,7 +567,8 @@ union bpf_attr { ...@@ -562,7 +567,8 @@ union bpf_attr {
FN(xdp_adjust_head), \ FN(xdp_adjust_head), \
FN(probe_read_str), \ FN(probe_read_str), \
FN(get_socket_cookie), \ FN(get_socket_cookie), \
FN(get_socket_uid), FN(get_socket_uid), \
FN(set_hash),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper /* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call * function eBPF program intends to call
......
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