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authorAlexei Starovoitov <ast@plumgrid.com>2015-04-01 17:12:13 -0700
committerDavid S. Miller <davem@davemloft.net>2015-04-06 16:42:35 -0400
commit91bc4822c3d61b9bb7ef66d3b77948a4f9177954 (patch)
treeca92a811b501957c1e876290d305aaf81c8d9aff /samples/bpf/bpf_helpers.h
parentMerge branch 'nf-hook-compress' (diff)
downloadlinux-dev-91bc4822c3d61b9bb7ef66d3b77948a4f9177954.tar.xz
linux-dev-91bc4822c3d61b9bb7ef66d3b77948a4f9177954.zip
tc: bpf: add checksum helpers
Commit 608cd71a9c7c ("tc: bpf: generalize pedit action") has added the possibility to mangle packet data to BPF programs in the tc pipeline. This patch adds two helpers bpf_l3_csum_replace() and bpf_l4_csum_replace() for fixing up the protocol checksums after the packet mangling. It also adds 'flags' argument to bpf_skb_store_bytes() helper to avoid unnecessary checksum recomputations when BPF programs adjusting l3/l4 checksums and documents all three helpers in uapi header. Moreover, a sample program is added to show how BPF programs can make use of the mangle and csum helpers. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples/bpf/bpf_helpers.h')
-rw-r--r--samples/bpf/bpf_helpers.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h
index ca0333146006..72540ec1f003 100644
--- a/samples/bpf/bpf_helpers.h
+++ b/samples/bpf/bpf_helpers.h
@@ -37,4 +37,11 @@ struct bpf_map_def {
unsigned int max_entries;
};
+static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
+ (void *) BPF_FUNC_skb_store_bytes;
+static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
+ (void *) BPF_FUNC_l3_csum_replace;
+static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
+ (void *) BPF_FUNC_l4_csum_replace;
+
#endif