[IPV6] ROUTE: Add support for fwmask in routing rules.

Add support for fwmark masks.
A mask of 0xFFFFFFFF is used when a mark value != 0 is sent without a mask.

Based on patch for net/ipv4/fib_rules.c by Patrick McHardy <kaber@trash.net>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 2 deletions

diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 3d64c71f52de..ee4aa43ad973 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -28,6 +28,7 @@ struct fib6_rule
         struct rt6key           dst;
 #ifdef CONFIG_IPV6_ROUTE_FWMARK
         u32                     fwmark;
+        u32                     fwmask;
 #endif
         u8                      tclass;
 };
@@ -128,7 +129,7 @@ static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
                 return 0;
 
 #ifdef CONFIG_IPV6_ROUTE_FWMARK
-        if (r->fwmark && (r->fwmark != fl->fl6_fwmark))
+        if ((r->fwmark ^ fl->fl6_fwmark) / r->fwmask)
                 return 0;
 #endif
 
@@ -141,6 +142,7 @@ static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = {
         [FRA_SRC]       = { .minlen = sizeof(struct in6_addr) },
         [FRA_DST]       = { .minlen = sizeof(struct in6_addr) },
         [FRA_FWMARK]    = { .type = NLA_U32 },
+        [FRA_FWMASK]    = { .type = NLA_U32 },
         [FRA_TABLE]     = { .type = NLA_U32 },
 };
 
@@ -174,8 +176,20 @@ static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
                            sizeof(struct in6_addr));
 
 #ifdef CONFIG_IPV6_ROUTE_FWMARK
-        if (tb[FRA_FWMARK])
+        if (tb[FRA_FWMARK]) {
                 rule6->fwmark = nla_get_u32(tb[FRA_FWMARK]);
+                if (rule6->fwmark) {
+                        /*
+                         * if the mark value is non-zero,
+                         * all bits are compared by default
+                         * unless a mask is explicitly specified.
+                         */
+                        rule6->fwmask = 0xFFFFFFFF;
+                }
+        }
+
+        if (tb[FRA_FWMASK])
+                rule6->fwmask = nla_get_u32(tb[FRA_FWMASK]);
 #endif
 
         rule6->src.plen = frh->src_len;
@@ -212,6 +226,9 @@ static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
 #ifdef CONFIG_IPV6_ROUTE_FWMARK
         if (tb[FRA_FWMARK] && (rule6->fwmark != nla_get_u32(tb[FRA_FWMARK])))
                 return 0;
+
+        if (tb[FRA_FWMASK] && (rule6->fwmask != nla_get_u32(tb[FRA_FWMASK])))
+                return 0;
 #endif
 
         return 1;
@@ -238,6 +255,9 @@ static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
 #ifdef CONFIG_IPV6_ROUTE_FWMARK
         if (rule6->fwmark)
                 NLA_PUT_U32(skb, FRA_FWMARK, rule6->fwmark);
+
+        if (rule6->fwmask)
+                NLA_PUT_U32(skb, FRA_FWMASK, rule6->fwmask);
 #endif
 
         return 0;