netfilter: speed up packet matching by allowing default rules to bypass the common...

SVN-Revision: 15177

diff --git a/target/linux/generic-2.6/patches-2.6.28/110-netfilter_match_speedup.patch b/target/linux/generic-2.6/patches-2.6.28/110-netfilter_match_speedup.patch
new file mode 100644 (file)
index 0000000..a8a49ec
--- /dev/null
+++ b/target/linux/generic-2.6/patches-2.6.28/110-netfilter_match_speedup.patch
@@ -0,0 +1,74 @@
+--- a/include/linux/netfilter_ipv4/ip_tables.h
++++ b/include/linux/netfilter_ipv4/ip_tables.h
+@@ -62,6 +62,7 @@ struct ipt_ip {
+ #define IPT_F_FRAG            0x01    /* Set if rule is a fragment rule */
+ #define IPT_F_GOTO            0x02    /* Set if jump is a goto */
+ #define IPT_F_MASK            0x03    /* All possible flag bits mask. */
++#define IPT_F_NO_DEF_MATCH    0x80    /* Internal: no default match rules present */
+ 
+ /* Values for "inv" field in struct ipt_ip. */
+ #define IPT_INV_VIA_IN                0x01    /* Invert the sense of IN IFACE. */
+--- a/net/ipv4/netfilter/ip_tables.c
++++ b/net/ipv4/netfilter/ip_tables.c
+@@ -88,6 +88,9 @@ ip_packet_match(const struct iphdr *ip,
+ 
+ #define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
+ 
++      if (ipinfo->flags & IPT_F_NO_DEF_MATCH)
++              return true;
++
+       if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
+                 IPT_INV_SRCIP)
+           || FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
+@@ -151,13 +154,32 @@ ip_packet_match(const struct iphdr *ip,
+               return false;
+       }
+ 
++#undef FWINV
+       return true;
+ }
+ 
+ static bool
+-ip_checkentry(const struct ipt_ip *ip)
++ip_checkentry(struct ipt_ip *ip)
+ {
+-      if (ip->flags & ~IPT_F_MASK) {
++#define FWINV(bool, invflg) ((bool) || (ip->invflags & (invflg)))
++
++      if (FWINV(ip->smsk.s_addr, IPT_INV_SRCIP) ||
++              FWINV(ip->dmsk.s_addr, IPT_INV_DSTIP))
++              goto has_match_rules;
++
++      if (FWINV(!!((const unsigned long *)ip->iniface_mask)[0],
++              IPT_INV_VIA_IN) ||
++          FWINV(!!((const unsigned long *)ip->outiface_mask)[0],
++              IPT_INV_VIA_OUT))
++              goto has_match_rules;
++
++      if (FWINV(ip->flags&IPT_F_FRAG, IPT_INV_FRAG))
++              goto has_match_rules;
++
++      ip->flags |= IPT_F_NO_DEF_MATCH;
++
++has_match_rules:
++      if (ip->flags & ~(IPT_F_MASK|IPT_F_NO_DEF_MATCH)) {
+               duprintf("Unknown flag bits set: %08X\n",
+                        ip->flags & ~IPT_F_MASK);
+               return false;
+@@ -167,6 +189,8 @@ ip_checkentry(const struct ipt_ip *ip)
+                        ip->invflags & ~IPT_INV_MASK);
+               return false;
+       }
++
++#undef FWINV
+       return true;
+ }
+ 
+@@ -214,7 +238,6 @@ unconditional(const struct ipt_ip *ip)
+                       return 0;
+ 
+       return 1;
+-#undef FWINV
+ }
+ 
+ #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \