net: ptp: do not reimplement PTP/BPF classifier

There are currently pch_gbe, cpts, and ixp4xx_eth drivers that open-code
and reimplement a BPF classifier for the PTP protocol. Since all of them
effectively do the very same thing and load the very same PTP/BPF filter,
we can just consolidate that code by introducing ptp_classify_raw() in
the time-stamping core framework which can be used in drivers.

As drivers get initialized after bootstrapping the core networking
subsystem, they can make use of ptp_insns wrapped through
ptp_classify_raw(), which allows to simplify and remove PTP classifier
setup code in drivers.

Joint work with Alexei Starovoitov.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Richard Cochran <richard.cochran@omicron.at>
Cc: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 8 deletions

diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h
index 3decfa4d3732..6d3b0a2ef9ce 100644
--- a/include/linux/ptp_classify.h
+++ b/include/linux/ptp_classify.h
@@ -80,14 +80,6 @@
 #define OP_RETA (BPF_RET | BPF_A)
 #define OP_RETK (BPF_RET | BPF_K)
 
-static inline int ptp_filter_init(struct sock_filter *f, int len)
-{
-        if (OP_LDH == f[0].code)
-                return sk_chk_filter(f, len);
-        else
-                return 0;
-}
-
 #define PTP_FILTER \
         {OP_LDH,        0,   0, OFF_ETYPE               }, /*              */ \
         {OP_JEQ,        0,  12, ETH_P_IP                }, /* f goto L20   */ \
@@ -133,4 +125,6 @@ static inline int ptp_filter_init(struct sock_filter *f, int len)
         {OP_RETA,       0,   0, 0                       }, /*              */ \
 /*L6x*/ {OP_RETK,       0,   0, PTP_CLASS_NONE          },
 
+unsigned int ptp_classify_raw(const struct sk_buff *skb);
+
 #endif