korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-24 20:54:10 +08:00
Code Issues Packages Projects Releases Wiki Activity

[IPV4] ip_fragment: Always compute hash with ipfrag_lock held.

Browse Source 
Otherwise we could compute an inaccurate hash due to the
random seed changing.

Noticed by Zach Brown and patch is based upon some feedback
from Herbert Xu.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2006-04-09 22:43:55 -07:00
parent 19910d1aec
commit 55c0022e53
1 changed files with 10 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
net/ipv4/ip_fragment.c
View File

@ -304,13 +304,17 @@ out:
/* Creation primitives. */
static struct ipq *ip_frag_intern(unsigned int hash, struct ipq *qp_in)
static struct ipq *ip_frag_intern(struct ipq *qp_in)
{
struct ipq *qp;
#ifdef CONFIG_SMP
struct hlist_node *n;
#endif
unsigned int hash;
write_lock(&ipfrag_lock);
hash = ipqhashfn(qp_in->id, qp_in->saddr, qp_in->daddr,
qp_in->protocol);
#ifdef CONFIG_SMP
/* With SMP race we have to recheck hash table, because
* such entry could be created on other cpu, while we
@ -345,7 +349,7 @@ static struct ipq *ip_frag_intern(unsigned int hash, struct ipq *qp_in)
}
/* Add an entry to the 'ipq' queue for a newly received IP datagram. */
static struct ipq *ip_frag_create(unsigned hash, struct iphdr *iph, u32 user)
static struct ipq *ip_frag_create(struct iphdr *iph, u32 user)
{
struct ipq *qp;
@ -371,7 +375,7 @@ static struct ipq *ip_frag_create(unsigned hash, struct iphdr *iph, u32 user)
spin_lock_init(&qp->lock);
atomic_set(&qp->refcnt, 1);
return ip_frag_intern(hash, qp);
return ip_frag_intern(qp);
out_nomem:
LIMIT_NETDEBUG(KERN_ERR "ip_frag_create: no memory left !\n");
@ -387,11 +391,12 @@ static inline struct ipq *ip_find(struct iphdr *iph, u32 user)
__u32 saddr = iph->saddr;
__u32 daddr = iph->daddr;
__u8 protocol = iph->protocol;
unsigned int hash = ipqhashfn(id, saddr, daddr, protocol);
unsigned int hash;
struct ipq *qp;
struct hlist_node *n;
read_lock(&ipfrag_lock);
hash = ipqhashfn(id, saddr, daddr, protocol);
hlist_for_each_entry(qp, n, &ipq_hash[hash], list) {
if(qp->id == id &&
qp->saddr == saddr &&
@ -405,7 +410,7 @@ static inline struct ipq *ip_find(struct iphdr *iph, u32 user)
}
read_unlock(&ipfrag_lock);
return ip_frag_create(hash, iph, user);
return ip_frag_create(iph, user);
}
/* Is the fragment too far ahead to be part of ipq? */