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authorEric Dumazet <edumazet@google.com>2012-10-27 06:26:17 +0400
committerDavid S. Miller <davem@davemloft.net>2012-10-31 22:00:15 +0400
commitf3335031b9452baebfe49b8b5e55d3fe0c4677d1 (patch)
treec73f4d2827d3b58b4866488a35b4b462e52713ba
parent0f6ae8f14e7a6a068e9a98a0d3484ffa6bf2c6bb (diff)
downloadlinux-f3335031b9452baebfe49b8b5e55d3fe0c4677d1.tar.xz
net: filter: add vlan tag access
BPF filters lack ability to access skb->vlan_tci This patch adds two new ancillary accessors : SKF_AD_VLAN_TAG (44) mapped to vlan_tx_tag_get(skb) SKF_AD_VLAN_TAG_PRESENT (48) mapped to vlan_tx_tag_present(skb) This allows libpcap/tcpdump to use a kernel filter instead of having to fallback to accept all packets, then filter them in user space. Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Ani Sinha <ani@aristanetworks.com> Suggested-by: Daniel Borkmann <danborkmann@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/filter.h2
-rw-r--r--include/uapi/linux/filter.h4
-rw-r--r--net/core/filter.c9
3 files changed, 14 insertions, 1 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 24d251f3bab0..c9f0005c35e2 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -123,6 +123,8 @@ enum {
BPF_S_ANC_CPU,
BPF_S_ANC_ALU_XOR_X,
BPF_S_ANC_SECCOMP_LD_W,
+ BPF_S_ANC_VLAN_TAG,
+ BPF_S_ANC_VLAN_TAG_PRESENT,
};
#endif /* __LINUX_FILTER_H__ */
diff --git a/include/uapi/linux/filter.h b/include/uapi/linux/filter.h
index 3d7922433aba..9cfde6941099 100644
--- a/include/uapi/linux/filter.h
+++ b/include/uapi/linux/filter.h
@@ -127,7 +127,9 @@ struct sock_fprog { /* Required for SO_ATTACH_FILTER. */
#define SKF_AD_RXHASH 32
#define SKF_AD_CPU 36
#define SKF_AD_ALU_XOR_X 40
-#define SKF_AD_MAX 44
+#define SKF_AD_VLAN_TAG 44
+#define SKF_AD_VLAN_TAG_PRESENT 48
+#define SKF_AD_MAX 52
#define SKF_NET_OFF (-0x100000)
#define SKF_LL_OFF (-0x200000)
diff --git a/net/core/filter.c b/net/core/filter.c
index 3d92ebb7fbcf..5a114d41bf11 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -39,6 +39,7 @@
#include <linux/reciprocal_div.h>
#include <linux/ratelimit.h>
#include <linux/seccomp.h>
+#include <linux/if_vlan.h>
/* No hurry in this branch
*
@@ -341,6 +342,12 @@ load_b:
case BPF_S_ANC_CPU:
A = raw_smp_processor_id();
continue;
+ case BPF_S_ANC_VLAN_TAG:
+ A = vlan_tx_tag_get(skb);
+ continue;
+ case BPF_S_ANC_VLAN_TAG_PRESENT:
+ A = !!vlan_tx_tag_present(skb);
+ continue;
case BPF_S_ANC_NLATTR: {
struct nlattr *nla;
@@ -600,6 +607,8 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen)
ANCILLARY(RXHASH);
ANCILLARY(CPU);
ANCILLARY(ALU_XOR_X);
+ ANCILLARY(VLAN_TAG);
+ ANCILLARY(VLAN_TAG_PRESENT);
}
}
ftest->code = code;