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authorEric Dumazet <edumazet@google.com>2012-07-04 22:30:09 +0000
committerDavid S. Miller <davem@davemloft.net>2012-07-05 03:03:32 -0700
commitbf5e53e3717ed28be69d0663c65962d1731e7ee4 (patch)
tree7211c0114426ece185d27e3d7c637ecf354fba72 /net/ipv4/ip_options.c
parent36bdbcae2fa2a6dfa99344d4190fcea0aa7b7c25 (diff)
ipv4: defer fib_compute_spec_dst() call
ip_options_compile() can avoid calling fib_compute_spec_dst() by default, and perform the call only if needed. David suggested to add a helper to make the call only once. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_options.c')
-rw-r--r--net/ipv4/ip_options.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index 1f022510abe3..a19d6471a318 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -242,6 +242,15 @@ void ip_options_fragment(struct sk_buff *skb)
opt->ts_needtime = 0;
}
+/* helper used by ip_options_compile() to call fib_compute_spec_dst()
+ * at most one time.
+ */
+static void spec_dst_fill(__be32 *spec_dst, struct sk_buff *skb)
+{
+ if (*spec_dst == htonl(INADDR_ANY))
+ *spec_dst = fib_compute_spec_dst(skb);
+}
+
/*
* Verify options and fill pointers in struct options.
* Caller should clear *opt, and set opt->data.
@@ -251,7 +260,7 @@ void ip_options_fragment(struct sk_buff *skb)
int ip_options_compile(struct net *net,
struct ip_options *opt, struct sk_buff *skb)
{
- __be32 spec_dst = (__force __be32) 0;
+ __be32 spec_dst = htonl(INADDR_ANY);
unsigned char *pp_ptr = NULL;
struct rtable *rt = NULL;
unsigned char *optptr;
@@ -260,8 +269,6 @@ int ip_options_compile(struct net *net,
if (skb != NULL) {
rt = skb_rtable(skb);
- if (rt)
- spec_dst = fib_compute_spec_dst(skb);
optptr = (unsigned char *)&(ip_hdr(skb)[1]);
} else
optptr = opt->__data;
@@ -334,6 +341,7 @@ int ip_options_compile(struct net *net,
goto error;
}
if (rt) {
+ spec_dst_fill(&spec_dst, skb);
memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
opt->is_changed = 1;
}
@@ -376,6 +384,7 @@ int ip_options_compile(struct net *net,
}
opt->ts = optptr - iph;
if (rt) {
+ spec_dst_fill(&spec_dst, skb);
memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
timeptr = &optptr[optptr[2]+3];
}