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Date: Sat, 13 Dec 2008 21:59:34 +0200 (EET)
From: "Ilpo Järvinen" <ilpo.jarvinen@...sinki.fi>
To: David Miller <davem@...emloft.net>
cc: Netdev <netdev@...r.kernel.org>
Subject: [PATCH] ipmr: merge common code
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@...sinki.fi>
---
net/ipv4/ipmr.c | 103 +++++++++++++++++++++----------------------------------
1 files changed, 39 insertions(+), 64 deletions(-)
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 244a624..1466644 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1482,29 +1482,13 @@ dont_forward:
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;
-
- if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
- goto drop;
+ struct net_device *reg_dev = NULL;
+ struct iphdr *encap;
- 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
--
1.5.2.2
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