* Patrick McHardy : LRU queue of frag heads for evictor.
*/
+#include <linux/compiler.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/checksum.h>
+#include <net/inetpeer.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/inet.h>
int sysctl_ipfrag_high_thresh = 256*1024;
int sysctl_ipfrag_low_thresh = 192*1024;
+int sysctl_ipfrag_max_dist = 64;
+
/* Important NOTE! Fragment queue must be destroyed before MSL expires.
* RFC791 is wrong proposing to prolongate timer each fragment arrival by TTL.
*/
/* Describe an entry in the "incomplete datagrams" queue. */
struct ipq {
- struct ipq *next; /* linked list pointers */
+ struct hlist_node list;
struct list_head lru_list; /* lru list member */
u32 user;
u32 saddr;
spinlock_t lock;
atomic_t refcnt;
struct timer_list timer; /* when will this queue expire? */
- struct ipq **pprev;
- int iif;
struct timeval stamp;
+ int iif;
+ unsigned int rid;
+ struct inet_peer *peer;
};
/* Hash table. */
#define IPQ_HASHSZ 64
/* Per-bucket lock is easy to add now. */
-static struct ipq *ipq_hash[IPQ_HASHSZ];
+static struct hlist_head ipq_hash[IPQ_HASHSZ];
static DEFINE_RWLOCK(ipfrag_lock);
static u32 ipfrag_hash_rnd;
static LIST_HEAD(ipq_lru_list);
static __inline__ void __ipq_unlink(struct ipq *qp)
{
- if(qp->next)
- qp->next->pprev = qp->pprev;
- *qp->pprev = qp->next;
+ hlist_del(&qp->list);
list_del(&qp->lru_list);
ip_frag_nqueues--;
}
get_random_bytes(&ipfrag_hash_rnd, sizeof(u32));
for (i = 0; i < IPQ_HASHSZ; i++) {
struct ipq *q;
+ struct hlist_node *p, *n;
- q = ipq_hash[i];
- while (q) {
- struct ipq *next = q->next;
+ hlist_for_each_entry_safe(q, p, n, &ipq_hash[i], list) {
unsigned int hval = ipqhashfn(q->id, q->saddr,
q->daddr, q->protocol);
if (hval != i) {
- /* Unlink. */
- if (q->next)
- q->next->pprev = q->pprev;
- *q->pprev = q->next;
+ hlist_del(&q->list);
/* Relink to new hash chain. */
- if ((q->next = ipq_hash[hval]) != NULL)
- q->next->pprev = &q->next;
- ipq_hash[hval] = q;
- q->pprev = &ipq_hash[hval];
+ hlist_add_head(&q->list, &ipq_hash[hval]);
}
-
- q = next;
}
}
write_unlock(&ipfrag_lock);
BUG_TRAP(qp->last_in&COMPLETE);
BUG_TRAP(del_timer(&qp->timer) == 0);
+ if (qp->peer)
+ inet_putpeer(qp->peer);
+
/* Release all fragment data. */
fp = qp->fragments;
while (fp) {
/* 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
* promoted read lock to write lock.
*/
- for(qp = ipq_hash[hash]; qp; qp = qp->next) {
+ hlist_for_each_entry(qp, n, &ipq_hash[hash], list) {
if(qp->id == qp_in->id &&
qp->saddr == qp_in->saddr &&
qp->daddr == qp_in->daddr &&
atomic_inc(&qp->refcnt);
atomic_inc(&qp->refcnt);
- if((qp->next = ipq_hash[hash]) != NULL)
- qp->next->pprev = &qp->next;
- ipq_hash[hash] = qp;
- qp->pprev = &ipq_hash[hash];
+ hlist_add_head(&qp->list, &ipq_hash[hash]);
INIT_LIST_HEAD(&qp->lru_list);
list_add_tail(&qp->lru_list, &ipq_lru_list);
ip_frag_nqueues++;
}
/* 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;
qp->meat = 0;
qp->fragments = NULL;
qp->iif = 0;
+ qp->peer = sysctl_ipfrag_max_dist ? inet_getpeer(iph->saddr, 1) : NULL;
/* Initialize a timer for this entry. */
init_timer(&qp->timer);
spin_lock_init(&qp->lock);
atomic_set(&qp->refcnt, 1);
- return ip_frag_intern(hash, qp);
+ return ip_frag_intern(qp);
out_nomem:
- NETDEBUG(if (net_ratelimit()) printk(KERN_ERR "ip_frag_create: no memory left !\n"));
+ LIMIT_NETDEBUG(KERN_ERR "ip_frag_create: no memory left !\n");
return NULL;
}
*/
static inline struct ipq *ip_find(struct iphdr *iph, u32 user)
{
- __u16 id = iph->id;
+ __be16 id = iph->id;
__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);
- for(qp = ipq_hash[hash]; qp; qp = qp->next) {
+ hash = ipqhashfn(id, saddr, daddr, protocol);
+ hlist_for_each_entry(qp, n, &ipq_hash[hash], list) {
if(qp->id == id &&
qp->saddr == saddr &&
qp->daddr == daddr &&
}
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? */
+static inline int ip_frag_too_far(struct ipq *qp)
+{
+ struct inet_peer *peer = qp->peer;
+ unsigned int max = sysctl_ipfrag_max_dist;
+ unsigned int start, end;
+
+ int rc;
+
+ if (!peer || !max)
+ return 0;
+
+ start = qp->rid;
+ end = atomic_inc_return(&peer->rid);
+ qp->rid = end;
+
+ rc = qp->fragments && (end - start) > max;
+
+ if (rc) {
+ IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ }
+
+ return rc;
+}
+
+static int ip_frag_reinit(struct ipq *qp)
+{
+ struct sk_buff *fp;
+
+ if (!mod_timer(&qp->timer, jiffies + sysctl_ipfrag_time)) {
+ atomic_inc(&qp->refcnt);
+ return -ETIMEDOUT;
+ }
+
+ fp = qp->fragments;
+ do {
+ struct sk_buff *xp = fp->next;
+ frag_kfree_skb(fp, NULL);
+ fp = xp;
+ } while (fp);
+
+ qp->last_in = 0;
+ qp->len = 0;
+ qp->meat = 0;
+ qp->fragments = NULL;
+ qp->iif = 0;
+
+ return 0;
}
/* Add new segment to existing queue. */
if (qp->last_in & COMPLETE)
goto err;
+ if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
+ unlikely(ip_frag_too_far(qp)) && unlikely(ip_frag_reinit(qp))) {
+ ipq_kill(qp);
+ goto err;
+ }
+
offset = ntohs(skb->nh.iph->frag_off);
flags = offset & ~IP_OFFSET;
offset &= IP_OFFSET;
if (pskb_pull(skb, ihl) == NULL)
goto err;
- if (pskb_trim(skb, end-offset))
+ if (pskb_trim_rcsum(skb, end-offset))
goto err;
/* Find out which fragments are in front and at the back of us
if (skb->dev)
qp->iif = skb->dev->ifindex;
skb->dev = NULL;
- qp->stamp = skb->stamp;
+ skb_get_timestamp(skb, &qp->stamp);
qp->meat += skb->len;
atomic_add(skb->truesize, &ip_frag_mem);
if (offset == 0)
head->next = NULL;
head->dev = dev;
- head->stamp = qp->stamp;
+ skb_set_timestamp(head, &qp->stamp);
iph = head->nh.iph;
iph->frag_off = 0;
return head;
out_nomem:
- NETDEBUG(if (net_ratelimit())
- printk(KERN_ERR
- "IP: queue_glue: no memory for gluing queue %p\n",
- qp));
+ LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing "
+ "queue %p\n", qp);
goto out_fail;
out_oversize:
if (net_ratelimit())
git://git.onelab.eu / linux-2.6.git / blobdiff