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ipmr: merge common code

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Also removes redundant skb->len < x check which can't
be true once pskb_may_pull(skb, x) succeeded.

$ diff-funcs pim_rcv ipmr.c ipmr.c pim_rcv_v1
  --- ipmr.c:pim_rcv()
  +++ ipmr.c:pim_rcv_v1()
@@ -1,22 +1,27 @@
-static int pim_rcv(struct sk_buff * skb)
+int pim_rcv_v1(struct sk_buff * skb)
 {
-	struct pimreghdr *pim;
+	struct igmphdr *pim;
 	struct iphdr   *encap;
 	struct net_device  *reg_dev = NULL;

 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
 		goto drop;

-	pim = (struct pimreghdr *)skb_transport_header(skb);
-	if (pim->type != ((PIM_VERSION<<4)|(PIM_REGISTER)) ||
-	    (pim->flags&PIM_NULL_REGISTER) ||
-	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
-	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
+	pim = igmp_hdr(skb);
+
+	if (!mroute_do_pim ||
+	    skb->len < sizeof(*pim) + sizeof(*encap) ||
+	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
 		goto drop;

-	/* check if the inner packet is destined to mcast group */
 	encap = (struct iphdr *)(skb_transport_header(skb) +
-				 sizeof(struct pimreghdr));
+				 sizeof(struct igmphdr));
+	/*
+	   Check that:
+	   a. packet is really destinted to a multicast group
+	   b. packet is not a NULL-REGISTER
+	   c. packet is not truncated
+	 */
 	if (!ipv4_is_multicast(encap->daddr) ||
 	    encap->tot_len == 0 ||
 	    ntohs(encap->tot_len) + sizeof(*pim) > skb->len)
@@ -40,9 +45,9 @@
 	skb->ip_summed = 0;
 	skb->pkt_type = PACKET_HOST;
 	dst_release(skb->dst);
+	skb->dst = NULL;
 	reg_dev->stats.rx_bytes += skb->len;
 	reg_dev->stats.rx_packets++;
-	skb->dst = NULL;
 	nf_reset(skb);
 	netif_rx(skb);
 	dev_put(reg_dev);

$ codiff net/ipv4/ipmr.o.old net/ipv4/ipmr.o.new

net/ipv4/ipmr.c:
  pim_rcv_v1 | -283
  pim_rcv    | -284
 2 functions changed, 567 bytes removed

net/ipv4/ipmr.c:
  __pim_rcv | +307
 1 function changed, 307 bytes added

net/ipv4/ipmr.o.new:
 3 functions changed, 307 bytes added, 567 bytes removed, diff: -260

(Tested on x86_64).

It seems that pimlen arg could be left out as well and
eq-sizedness of structs trapped with BUILD_BUG_ON but
I don't think that's more than a cosmetic flaw since there
aren't that many args anyway.

Compile tested.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ilpo Järvinen 2008-12-16 01:15:11 -08:00 committed by David S. Miller
parent c40cf519f0
commit b1879204dd
1 changed files with 39 additions and 64 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

103
net/ipv4/ipmr.c
View file

@ -1482,29 +1482,13 @@ int ip_mr_input(struct sk_buff *skb)
return 0;
}
#ifdef CONFIG_IP_PIMSM_V1
/*
* Handle IGMP messages of PIMv1
*/
int pim_rcv_v1(struct sk_buff * skb)
#ifdef CONFIG_IP_PIMSM
static int __pim_rcv(struct sk_buff *skb, unsigned int pimlen)
{
struct igmphdr *pim;
struct iphdr *encap;
struct net_device *reg_dev = NULL;
struct net_device *reg_dev = NULL;
struct iphdr *encap;
if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
goto drop;
pim = igmp_hdr(skb);
if (!mroute_do_pim ||
skb->len < sizeof(*pim) + sizeof(*encap) ||
pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
goto drop;
encap = (struct iphdr *)(skb_transport_header(skb) +
sizeof(struct igmphdr));
encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
/*
Check that:
a. packet is really destinted to a multicast group
@ -1513,8 +1497,8 @@ int pim_rcv_v1(struct sk_buff * skb)
*/
if (!ipv4_is_multicast(encap->daddr) ||
encap->tot_len == 0 ||
ntohs(encap->tot_len) + sizeof(*pim) > skb->len)
goto drop;
ntohs(encap->tot_len) + pimlen > skb->len)
return 1;
read_lock(&mrt_lock);
if (reg_vif_num >= 0)
@ -1524,7 +1508,7 @@ int pim_rcv_v1(struct sk_buff * skb)
read_unlock(&mrt_lock);
if (reg_dev == NULL)
goto drop;
return 1;
skb->mac_header = skb->network_header;
skb_pull(skb, (u8*)encap - skb->data);
@ -1540,9 +1524,33 @@ int pim_rcv_v1(struct sk_buff * skb)
nf_reset(skb);
netif_rx(skb);
dev_put(reg_dev);
return 0;
drop:
kfree_skb(skb);
}
#endif
#ifdef CONFIG_IP_PIMSM_V1
/*
* Handle IGMP messages of PIMv1
*/
int pim_rcv_v1(struct sk_buff * skb)
{
struct igmphdr *pim;
if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
goto drop;
pim = igmp_hdr(skb);
if (!mroute_do_pim ||
pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
goto drop;
if (__pim_rcv(skb, sizeof(*pim))) {
drop:
kfree_skb(skb);
}
return 0;
}
#endif
@ -1551,10 +1559,8 @@ int pim_rcv_v1(struct sk_buff * skb)
static int pim_rcv(struct sk_buff * skb)
{
struct pimreghdr *pim;
struct iphdr *encap;
struct net_device *reg_dev = NULL;
if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
goto drop;
pim = (struct pimreghdr *)skb_transport_header(skb);
@ -1564,41 +1570,10 @@ static int pim_rcv(struct sk_buff * skb)
csum_fold(skb_checksum(skb, 0, skb->len, 0))))
goto drop;
/* check if the inner packet is destined to mcast group */
encap = (struct iphdr *)(skb_transport_header(skb) +
sizeof(struct pimreghdr));
if (!ipv4_is_multicast(encap->daddr) ||
encap->tot_len == 0 ||
ntohs(encap->tot_len) + sizeof(*pim) > skb->len)
goto drop;
read_lock(&mrt_lock);
if (reg_vif_num >= 0)
reg_dev = vif_table[reg_vif_num].dev;
if (reg_dev)
dev_hold(reg_dev);
read_unlock(&mrt_lock);
if (reg_dev == NULL)
goto drop;
skb->mac_header = skb->network_header;
skb_pull(skb, (u8*)encap - skb->data);
skb_reset_network_header(skb);
skb->dev = reg_dev;
skb->protocol = htons(ETH_P_IP);
skb->ip_summed = 0;
skb->pkt_type = PACKET_HOST;
dst_release(skb->dst);
reg_dev->stats.rx_bytes += skb->len;
reg_dev->stats.rx_packets++;
skb->dst = NULL;
nf_reset(skb);
netif_rx(skb);
dev_put(reg_dev);
return 0;
drop:
kfree_skb(skb);
if (__pim_rcv(skb, sizeof(*pim))) {
drop:
kfree_skb(skb);
}
return 0;
}
#endif