* Patrick McHardy : LRU queue of frag heads for evictor.
*/
-#include <linux/config.h>
+#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.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>
* even the most extreme cases without allowing an attacker to measurably
* harm machine performance.
*/
-int sysctl_ipfrag_high_thresh = 256*1024;
-int sysctl_ipfrag_low_thresh = 192*1024;
+int sysctl_ipfrag_high_thresh __read_mostly = 256*1024;
+int sysctl_ipfrag_low_thresh __read_mostly = 192*1024;
+
+int sysctl_ipfrag_max_dist __read_mostly = 64;
/* Important NOTE! Fragment queue must be destroyed before MSL expires.
* RFC791 is wrong proposing to prolongate timer each fragment arrival by TTL.
*/
-int sysctl_ipfrag_time = IP_FRAG_TIME;
+int sysctl_ipfrag_time __read_mostly = IP_FRAG_TIME;
struct ipfrag_skb_cb
{
/* 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 saddr;
- u32 daddr;
- u16 id;
+ u32 user;
+ __be32 saddr;
+ __be32 daddr;
+ __be16 id;
u8 protocol;
u8 last_in;
#define COMPLETE 4
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 rwlock_t ipfrag_lock = RW_LOCK_UNLOCKED;
+static struct hlist_head ipq_hash[IPQ_HASHSZ];
+static DEFINE_RWLOCK(ipfrag_lock);
static u32 ipfrag_hash_rnd;
static LIST_HEAD(ipq_lru_list);
int ip_frag_nqueues = 0;
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--;
}
write_unlock(&ipfrag_lock);
}
-static unsigned int ipqhashfn(u16 id, u32 saddr, u32 daddr, u8 prot)
+static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
{
- return jhash_3words((u32)id << 16 | prot, saddr, daddr,
+ return jhash_3words((__force u32)id << 16 | prot,
+ (__force u32)saddr, (__force u32)daddr,
ipfrag_hash_rnd) & (IPQ_HASHSZ - 1);
}
static struct timer_list ipfrag_secret_timer;
-int sysctl_ipfrag_secret_interval = 10 * 60 * HZ;
+int sysctl_ipfrag_secret_interval __read_mostly = 10 * 60 * HZ;
static void ipfrag_secret_rebuild(unsigned long dummy)
{
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);
atomic_t ip_frag_mem = ATOMIC_INIT(0); /* Memory used for fragments */
/* Memory Tracking Functions. */
-static __inline__ void frag_kfree_skb(struct sk_buff *skb)
+static __inline__ void frag_kfree_skb(struct sk_buff *skb, int *work)
{
+ if (work)
+ *work -= skb->truesize;
atomic_sub(skb->truesize, &ip_frag_mem);
kfree_skb(skb);
}
-static __inline__ void frag_free_queue(struct ipq *qp)
+static __inline__ void frag_free_queue(struct ipq *qp, int *work)
{
+ if (work)
+ *work -= sizeof(struct ipq);
atomic_sub(sizeof(struct ipq), &ip_frag_mem);
kfree(qp);
}
/* Destruction primitives. */
/* Complete destruction of ipq. */
-static void ip_frag_destroy(struct ipq *qp)
+static void ip_frag_destroy(struct ipq *qp, int *work)
{
struct sk_buff *fp;
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) {
struct sk_buff *xp = fp->next;
- frag_kfree_skb(fp);
+ frag_kfree_skb(fp, work);
fp = xp;
}
/* Finally, release the queue descriptor itself. */
- frag_free_queue(qp);
+ frag_free_queue(qp, work);
}
-static __inline__ void ipq_put(struct ipq *ipq)
+static __inline__ void ipq_put(struct ipq *ipq, int *work)
{
if (atomic_dec_and_test(&ipq->refcnt))
- ip_frag_destroy(ipq);
+ ip_frag_destroy(ipq, work);
}
/* Kill ipq entry. It is not destroyed immediately,
}
/* Memory limiting on fragments. Evictor trashes the oldest
- * fragment queue until we are back under the low threshold.
+ * fragment queue until we are back under the threshold.
*/
static void ip_evictor(void)
{
struct ipq *qp;
struct list_head *tmp;
+ int work;
- for(;;) {
- if (atomic_read(&ip_frag_mem) <= sysctl_ipfrag_low_thresh)
- return;
+ work = atomic_read(&ip_frag_mem) - sysctl_ipfrag_low_thresh;
+ if (work <= 0)
+ return;
+
+ while (work > 0) {
read_lock(&ipfrag_lock);
if (list_empty(&ipq_lru_list)) {
read_unlock(&ipfrag_lock);
ipq_kill(qp);
spin_unlock(&qp->lock);
- ipq_put(qp);
- IP_INC_STATS_BH(ReasmFails);
+ ipq_put(qp, &work);
+ IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
}
}
ipq_kill(qp);
- IP_INC_STATS_BH(ReasmTimeout);
- IP_INC_STATS_BH(ReasmFails);
+ IP_INC_STATS_BH(IPSTATS_MIB_REASMTIMEOUT);
+ IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
if ((qp->last_in&FIRST_IN) && qp->fragments != NULL) {
struct sk_buff *head = qp->fragments;
}
out:
spin_unlock(&qp->lock);
- ipq_put(qp);
+ ipq_put(qp, NULL);
}
/* 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 &&
- qp->protocol == qp_in->protocol) {
+ qp->protocol == qp_in->protocol &&
+ qp->user == qp_in->user) {
atomic_inc(&qp->refcnt);
write_unlock(&ipfrag_lock);
qp_in->last_in |= COMPLETE;
- ipq_put(qp_in);
+ ipq_put(qp_in, NULL);
return qp;
}
}
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)
+static struct ipq *ip_frag_create(struct iphdr *iph, u32 user)
{
struct ipq *qp;
qp->id = iph->id;
qp->saddr = iph->saddr;
qp->daddr = iph->daddr;
+ qp->user = user;
qp->len = 0;
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);
qp->timer.data = (unsigned long) qp; /* pointer to queue */
qp->timer.function = ip_expire; /* expire function */
- qp->lock = SPIN_LOCK_UNLOCKED;
+ 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;
}
/* Find the correct entry in the "incomplete datagrams" queue for
* this IP datagram, and create new one, if nothing is found.
*/
-static inline struct ipq *ip_find(struct iphdr *iph)
+static inline struct ipq *ip_find(struct iphdr *iph, u32 user)
{
- __u16 id = iph->id;
- __u32 saddr = iph->saddr;
- __u32 daddr = iph->daddr;
+ __be16 id = iph->id;
+ __be32 saddr = iph->saddr;
+ __be32 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 &&
- qp->protocol == protocol) {
+ qp->protocol == protocol &&
+ qp->user == user) {
atomic_inc(&qp->refcnt);
read_unlock(&ipfrag_lock);
return qp;
}
read_unlock(&ipfrag_lock);
- return ip_frag_create(hash, iph);
+ 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
} else {
struct sk_buff *free_it = next;
- /* Old fragmnet is completely overridden with
+ /* Old fragment is completely overridden with
* new one drop it.
*/
next = next->next;
qp->fragments = next;
qp->meat -= free_it->len;
- frag_kfree_skb(free_it);
+ frag_kfree_skb(free_it, NULL);
}
}
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->len += fp->len;
if (head->ip_summed != fp->ip_summed)
head->ip_summed = CHECKSUM_NONE;
- else if (head->ip_summed == CHECKSUM_HW)
+ else if (head->ip_summed == CHECKSUM_COMPLETE)
head->csum = csum_add(head->csum, fp->csum);
head->truesize += fp->truesize;
atomic_sub(fp->truesize, &ip_frag_mem);
head->next = NULL;
head->dev = dev;
- head->stamp = qp->stamp;
+ skb_set_timestamp(head, &qp->stamp);
iph = head->nh.iph;
iph->frag_off = 0;
iph->tot_len = htons(len);
- IP_INC_STATS_BH(ReasmOKs);
+ IP_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
qp->fragments = NULL;
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())
"Oversized IP packet from %d.%d.%d.%d.\n",
NIPQUAD(qp->saddr));
out_fail:
- IP_INC_STATS_BH(ReasmFails);
+ IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
return NULL;
}
/* Process an incoming IP datagram fragment. */
-struct sk_buff *ip_defrag(struct sk_buff *skb)
+struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user)
{
struct iphdr *iph = skb->nh.iph;
struct ipq *qp;
struct net_device *dev;
- IP_INC_STATS_BH(ReasmReqds);
+ IP_INC_STATS_BH(IPSTATS_MIB_REASMREQDS);
/* Start by cleaning up the memory. */
if (atomic_read(&ip_frag_mem) > sysctl_ipfrag_high_thresh)
dev = skb->dev;
/* Lookup (or create) queue header */
- if ((qp = ip_find(iph)) != NULL) {
+ if ((qp = ip_find(iph, user)) != NULL) {
struct sk_buff *ret = NULL;
spin_lock(&qp->lock);
ret = ip_frag_reasm(qp, dev);
spin_unlock(&qp->lock);
- ipq_put(qp);
+ ipq_put(qp, NULL);
return ret;
}
- IP_INC_STATS_BH(ReasmFails);
+ IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
kfree_skb(skb);
return NULL;
}
git://git.onelab.eu / linux-2.6.git / blobdiff