Commit 0ba98502 authored by Shmulik Ladkani's avatar Shmulik Ladkani Committed by Daniel Borkmann
Browse files

flow_dissector: Make 'bpf_flow_dissect' return the bpf program retcode 



Let 'bpf_flow_dissect' callers know the BPF program's retcode and act
accordingly.

Signed-off-by: default avatarShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarStanislav Fomichev <sdf@google.com>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220821113519.116765-2-shmulik.ladkani@gmail.com
parent b979f005

include/linux/skbuff.h

+2 −2
Original line number Diff line number Diff line
@@ -1460,7 +1460,7 @@ void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 
			     unsigned int key_count);



struct bpf_flow_dissector;

bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,

u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,

		     __be16 proto, int nhoff, int hlen, unsigned int flags);



bool __skb_flow_dissect(const struct net *net,

net/bpf/test_run.c

+1 −1
Original line number Diff line number Diff line
@@ -1445,7 +1445,7 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, 
	bpf_test_timer_enter(&t);

	do {

		retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,

					  size, flags);

					  size, flags) == BPF_OK;

	} while (bpf_test_timer_continue(&t, 1, repeat, &ret, &duration));

	bpf_test_timer_leave(&t);

net/core/flow_dissector.c

+7 −6
Original line number Diff line number Diff line
@@ -866,7 +866,7 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, 
	}

}



bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,

u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,

		     __be16 proto, int nhoff, int hlen, unsigned int flags)

{

	struct bpf_flow_keys *flow_keys = ctx->flow_keys;
@@ -892,7 +892,7 @@ bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, 
	flow_keys->thoff = clamp_t(u16, flow_keys->thoff,

				   flow_keys->nhoff, hlen);



	return result == BPF_OK;

	return result;

}



static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr)
@@ -1008,6 +1008,7 @@ bool __skb_flow_dissect(const struct net *net, 
			};

			__be16 n_proto = proto;

			struct bpf_prog *prog;

			u32 result;



			if (skb) {

				ctx.skb = skb;
@@ -1019,12 +1020,12 @@ bool __skb_flow_dissect(const struct net *net, 
			}



			prog = READ_ONCE(run_array->items[0].prog);

			ret = bpf_flow_dissect(prog, &ctx, n_proto, nhoff,

			result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff,

						  hlen, flags);

			__skb_flow_bpf_to_target(&flow_keys, flow_dissector,

						 target_container);

			rcu_read_unlock();

			return ret;

			return result == BPF_OK;

		}

		rcu_read_unlock();

	}