*
* The IP fragmentation functionality.
*
- * Version: $Id: ip_fragment.c,v 1.59 2002/01/12 07:54:56 davem Exp $
- *
* Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
- * Alan Cox <Alan.Cox@linux.org>
+ * Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* Fixes:
* Alan Cox : Split from ip.c , see ip_input.c for history.
* as well. Or notify me, at least. --ANK
*/
-int sysctl_ipfrag_max_dist __read_mostly = 64;
+static int sysctl_ipfrag_max_dist __read_mostly = 64;
struct ipfrag_skb_cb
{
int offset;
};
-#define FRAG_CB(skb) ((struct ipfrag_skb_cb*)((skb)->cb))
+#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb))
/* Describe an entry in the "incomplete datagrams" queue. */
struct ipq {
struct inet_peer *peer;
};
-struct inet_frags_ctl ip4_frags_ctl __read_mostly = {
- /*
- * Fragment cache limits. We will commit 256K at one time. Should we
- * cross that limit we will prune down to 192K. This should cope with
- * even the most extreme cases without allowing an attacker to
- * measurably harm machine performance.
- */
- .high_thresh = 256 * 1024,
- .low_thresh = 192 * 1024,
-
- /*
- * Important NOTE! Fragment queue must be destroyed before MSL expires.
- * RFC791 is wrong proposing to prolongate timer each fragment arrival
- * by TTL.
- */
- .timeout = IP_FRAG_TIME,
- .secret_interval = 10 * 60 * HZ,
-};
-
static struct inet_frags ip4_frags;
-int ip_frag_nqueues(void)
+int ip_frag_nqueues(struct net *net)
{
- return ip4_frags.nqueues;
+ return net->ipv4.frags.nqueues;
}
-int ip_frag_mem(void)
+int ip_frag_mem(struct net *net)
{
- return atomic_read(&ip4_frags.mem);
+ return atomic_read(&net->ipv4.frags.mem);
}
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
struct net_device *dev);
+struct ip4_create_arg {
+ struct iphdr *iph;
+ u32 user;
+};
+
static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
{
return jhash_3words((__force u32)id << 16 | prot,
return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol);
}
+static int ip4_frag_match(struct inet_frag_queue *q, void *a)
+{
+ struct ipq *qp;
+ struct ip4_create_arg *arg = a;
+
+ qp = container_of(q, struct ipq, q);
+ return (qp->id == arg->iph->id &&
+ qp->saddr == arg->iph->saddr &&
+ qp->daddr == arg->iph->daddr &&
+ qp->protocol == arg->iph->protocol &&
+ qp->user == arg->user);
+}
+
/* Memory Tracking Functions. */
-static __inline__ void frag_kfree_skb(struct sk_buff *skb, int *work)
+static __inline__ void frag_kfree_skb(struct netns_frags *nf,
+ struct sk_buff *skb, int *work)
{
if (work)
*work -= skb->truesize;
- atomic_sub(skb->truesize, &ip4_frags.mem);
+ atomic_sub(skb->truesize, &nf->mem);
kfree_skb(skb);
}
+static void ip4_frag_init(struct inet_frag_queue *q, void *a)
+{
+ struct ipq *qp = container_of(q, struct ipq, q);
+ struct ip4_create_arg *arg = a;
+
+ qp->protocol = arg->iph->protocol;
+ qp->id = arg->iph->id;
+ qp->saddr = arg->iph->saddr;
+ qp->daddr = arg->iph->daddr;
+ qp->user = arg->user;
+ qp->peer = sysctl_ipfrag_max_dist ?
+ inet_getpeer(arg->iph->saddr, 1) : NULL;
+}
+
static __inline__ void ip4_frag_free(struct inet_frag_queue *q)
{
struct ipq *qp;
qp = container_of(q, struct ipq, q);
if (qp->peer)
inet_putpeer(qp->peer);
- kfree(qp);
-}
-
-static __inline__ struct ipq *frag_alloc_queue(void)
-{
- struct ipq *qp = kmalloc(sizeof(struct ipq), GFP_ATOMIC);
-
- if (!qp)
- return NULL;
- atomic_add(sizeof(struct ipq), &ip4_frags.mem);
- return qp;
}
/* Memory limiting on fragments. Evictor trashes the oldest
* fragment queue until we are back under the threshold.
*/
-static void ip_evictor(void)
+static void ip_evictor(struct net *net)
{
int evicted;
- evicted = inet_frag_evictor(&ip4_frags);
+ evicted = inet_frag_evictor(&net->ipv4.frags, &ip4_frags);
if (evicted)
- IP_ADD_STATS_BH(IPSTATS_MIB_REASMFAILS, evicted);
+ IP_ADD_STATS_BH(net, IPSTATS_MIB_REASMFAILS, evicted);
}
/*
*/
static void ip_expire(unsigned long arg)
{
- struct ipq *qp = (struct ipq *) arg;
+ struct ipq *qp;
+ struct net *net;
+
+ qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
+ net = container_of(qp->q.net, struct net, ipv4.frags);
spin_lock(&qp->q.lock);
- if (qp->q.last_in & COMPLETE)
+ if (qp->q.last_in & INET_FRAG_COMPLETE)
goto out;
ipq_kill(qp);
- IP_INC_STATS_BH(IPSTATS_MIB_REASMTIMEOUT);
- IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
- if ((qp->q.last_in&FIRST_IN) && qp->q.fragments != NULL) {
+ if ((qp->q.last_in & INET_FRAG_FIRST_IN) && qp->q.fragments != NULL) {
struct sk_buff *head = qp->q.fragments;
+
/* Send an ICMP "Fragment Reassembly Timeout" message. */
- if ((head->dev = dev_get_by_index(&init_net, qp->iif)) != NULL) {
+ rcu_read_lock();
+ head->dev = dev_get_by_index_rcu(net, qp->iif);
+ if (head->dev)
icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
- dev_put(head->dev);
- }
+ rcu_read_unlock();
}
out:
spin_unlock(&qp->q.lock);
ipq_put(qp);
}
-/* Creation primitives. */
-
-static struct ipq *ip_frag_intern(struct ipq *qp_in)
+/* 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 net *net, struct iphdr *iph, u32 user)
{
- struct ipq *qp;
-#ifdef CONFIG_SMP
- struct hlist_node *n;
-#endif
+ struct inet_frag_queue *q;
+ struct ip4_create_arg arg;
unsigned int hash;
- write_lock(&ip4_frags.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.
- */
- hlist_for_each_entry(qp, n, &ip4_frags.hash[hash], q.list) {
- if (qp->id == qp_in->id &&
- qp->saddr == qp_in->saddr &&
- qp->daddr == qp_in->daddr &&
- qp->protocol == qp_in->protocol &&
- qp->user == qp_in->user) {
- atomic_inc(&qp->q.refcnt);
- write_unlock(&ip4_frags.lock);
- qp_in->q.last_in |= COMPLETE;
- ipq_put(qp_in);
- return qp;
- }
- }
-#endif
- qp = qp_in;
-
- if (!mod_timer(&qp->q.timer, jiffies + ip4_frags_ctl.timeout))
- atomic_inc(&qp->q.refcnt);
-
- atomic_inc(&qp->q.refcnt);
- hlist_add_head(&qp->q.list, &ip4_frags.hash[hash]);
- INIT_LIST_HEAD(&qp->q.lru_list);
- list_add_tail(&qp->q.lru_list, &ip4_frags.lru_list);
- ip4_frags.nqueues++;
- write_unlock(&ip4_frags.lock);
- return qp;
-}
+ arg.iph = iph;
+ arg.user = user;
-/* Add an entry to the 'ipq' queue for a newly received IP datagram. */
-static struct ipq *ip_frag_create(struct iphdr *iph, u32 user)
-{
- struct ipq *qp;
+ read_lock(&ip4_frags.lock);
+ hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
- if ((qp = frag_alloc_queue()) == NULL)
+ q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash);
+ if (q == NULL)
goto out_nomem;
- qp->protocol = iph->protocol;
- qp->q.last_in = 0;
- qp->id = iph->id;
- qp->saddr = iph->saddr;
- qp->daddr = iph->daddr;
- qp->user = user;
- qp->q.len = 0;
- qp->q.meat = 0;
- qp->q.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->q.timer);
- qp->q.timer.data = (unsigned long) qp; /* pointer to queue */
- qp->q.timer.function = ip_expire; /* expire function */
- spin_lock_init(&qp->q.lock);
- atomic_set(&qp->q.refcnt, 1);
-
- return ip_frag_intern(qp);
+ return container_of(q, struct ipq, q);
out_nomem:
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, u32 user)
-{
- __be16 id = iph->id;
- __be32 saddr = iph->saddr;
- __be32 daddr = iph->daddr;
- __u8 protocol = iph->protocol;
- unsigned int hash;
- struct ipq *qp;
- struct hlist_node *n;
-
- read_lock(&ip4_frags.lock);
- hash = ipqhashfn(id, saddr, daddr, protocol);
- hlist_for_each_entry(qp, n, &ip4_frags.hash[hash], q.list) {
- if (qp->id == id &&
- qp->saddr == saddr &&
- qp->daddr == daddr &&
- qp->protocol == protocol &&
- qp->user == user) {
- atomic_inc(&qp->q.refcnt);
- read_unlock(&ip4_frags.lock);
- return qp;
- }
- }
- read_unlock(&ip4_frags.lock);
-
- 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)
{
rc = qp->q.fragments && (end - start) > max;
if (rc) {
- IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ struct net *net;
+
+ net = container_of(qp->q.net, struct net, ipv4.frags);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
}
return rc;
{
struct sk_buff *fp;
- if (!mod_timer(&qp->q.timer, jiffies + ip4_frags_ctl.timeout)) {
+ if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
atomic_inc(&qp->q.refcnt);
return -ETIMEDOUT;
}
fp = qp->q.fragments;
do {
struct sk_buff *xp = fp->next;
- frag_kfree_skb(fp, NULL);
+ frag_kfree_skb(qp->q.net, fp, NULL);
fp = xp;
} while (fp);
int ihl, end;
int err = -ENOENT;
- if (qp->q.last_in & COMPLETE)
+ if (qp->q.last_in & INET_FRAG_COMPLETE)
goto err;
if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
* or have different end, the segment is corrrupted.
*/
if (end < qp->q.len ||
- ((qp->q.last_in & LAST_IN) && end != qp->q.len))
+ ((qp->q.last_in & INET_FRAG_LAST_IN) && end != qp->q.len))
goto err;
- qp->q.last_in |= LAST_IN;
+ qp->q.last_in |= INET_FRAG_LAST_IN;
qp->q.len = end;
} else {
if (end&7) {
}
if (end > qp->q.len) {
/* Some bits beyond end -> corruption. */
- if (qp->q.last_in & LAST_IN)
+ if (qp->q.last_in & INET_FRAG_LAST_IN)
goto err;
qp->q.len = end;
}
qp->q.fragments = next;
qp->q.meat -= free_it->len;
- frag_kfree_skb(free_it, NULL);
+ frag_kfree_skb(qp->q.net, free_it, NULL);
}
}
}
qp->q.stamp = skb->tstamp;
qp->q.meat += skb->len;
- atomic_add(skb->truesize, &ip4_frags.mem);
+ atomic_add(skb->truesize, &qp->q.net->mem);
if (offset == 0)
- qp->q.last_in |= FIRST_IN;
+ qp->q.last_in |= INET_FRAG_FIRST_IN;
- if (qp->q.last_in == (FIRST_IN | LAST_IN) && qp->q.meat == qp->q.len)
+ if (qp->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
+ qp->q.meat == qp->q.len)
return ip_frag_reasm(qp, prev, dev);
write_lock(&ip4_frags.lock);
- list_move_tail(&qp->q.lru_list, &ip4_frags.lru_list);
+ list_move_tail(&qp->q.lru_list, &qp->q.net->lru_list);
write_unlock(&ip4_frags.lock);
return -EINPROGRESS;
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
struct net_device *dev)
{
+ struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
struct iphdr *iph;
struct sk_buff *fp, *head = qp->q.fragments;
int len;
if (prev) {
head = prev->next;
fp = skb_clone(head, GFP_ATOMIC);
-
if (!fp)
goto out_nomem;
qp->q.fragments = head;
}
- BUG_TRAP(head != NULL);
- BUG_TRAP(FRAG_CB(head)->offset == 0);
+ WARN_ON(head == NULL);
+ WARN_ON(FRAG_CB(head)->offset != 0);
/* Allocate a new buffer for the datagram. */
ihlen = ip_hdrlen(head);
goto out_oversize;
/* Head of list must not be cloned. */
- err = -ENOMEM;
if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
goto out_nomem;
/* If the first fragment is fragmented itself, we split
* it to two chunks: the first with data and paged part
* and the second, holding only fragments. */
- if (skb_shinfo(head)->frag_list) {
+ if (skb_has_frags(head)) {
struct sk_buff *clone;
int i, plen = 0;
clone->next = head->next;
head->next = clone;
skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
- skb_shinfo(head)->frag_list = NULL;
+ skb_frag_list_init(head);
for (i=0; i<skb_shinfo(head)->nr_frags; i++)
plen += skb_shinfo(head)->frags[i].size;
clone->len = clone->data_len = head->data_len - plen;
head->len -= clone->len;
clone->csum = 0;
clone->ip_summed = head->ip_summed;
- atomic_add(clone->truesize, &ip4_frags.mem);
+ atomic_add(clone->truesize, &qp->q.net->mem);
}
skb_shinfo(head)->frag_list = head->next;
skb_push(head, head->data - skb_network_header(head));
- atomic_sub(head->truesize, &ip4_frags.mem);
+ atomic_sub(head->truesize, &qp->q.net->mem);
for (fp=head->next; fp; fp = fp->next) {
head->data_len += fp->len;
else if (head->ip_summed == CHECKSUM_COMPLETE)
head->csum = csum_add(head->csum, fp->csum);
head->truesize += fp->truesize;
- atomic_sub(fp->truesize, &ip4_frags.mem);
+ atomic_sub(fp->truesize, &qp->q.net->mem);
}
head->next = NULL;
iph = ip_hdr(head);
iph->frag_off = 0;
iph->tot_len = htons(len);
- IP_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);
qp->q.fragments = NULL;
return 0;
out_nomem:
LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing "
"queue %p\n", qp);
+ err = -ENOMEM;
goto out_fail;
out_oversize:
if (net_ratelimit())
- printk(KERN_INFO
- "Oversized IP packet from %d.%d.%d.%d.\n",
- NIPQUAD(qp->saddr));
+ printk(KERN_INFO "Oversized IP packet from %pI4.\n",
+ &qp->saddr);
out_fail:
- IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
return err;
}
int ip_defrag(struct sk_buff *skb, u32 user)
{
struct ipq *qp;
+ struct net *net;
- IP_INC_STATS_BH(IPSTATS_MIB_REASMREQDS);
+ net = skb->dev ? dev_net(skb->dev) : dev_net(skb_dst(skb)->dev);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS);
/* Start by cleaning up the memory. */
- if (atomic_read(&ip4_frags.mem) > ip4_frags_ctl.high_thresh)
- ip_evictor();
+ if (atomic_read(&net->ipv4.frags.mem) > net->ipv4.frags.high_thresh)
+ ip_evictor(net);
/* Lookup (or create) queue header */
- if ((qp = ip_find(ip_hdr(skb), user)) != NULL) {
+ if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
int ret;
spin_lock(&qp->q.lock);
return ret;
}
- IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
kfree_skb(skb);
return -ENOMEM;
}
+#ifdef CONFIG_SYSCTL
+static int zero;
+
+static struct ctl_table ip4_frags_ns_ctl_table[] = {
+ {
+ .procname = "ipfrag_high_thresh",
+ .data = &init_net.ipv4.frags.high_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ {
+ .procname = "ipfrag_low_thresh",
+ .data = &init_net.ipv4.frags.low_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ {
+ .procname = "ipfrag_time",
+ .data = &init_net.ipv4.frags.timeout,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ { }
+};
+
+static struct ctl_table ip4_frags_ctl_table[] = {
+ {
+ .procname = "ipfrag_secret_interval",
+ .data = &ip4_frags.secret_interval,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_jiffies,
+ },
+ {
+ .procname = "ipfrag_max_dist",
+ .data = &sysctl_ipfrag_max_dist,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero
+ },
+ { }
+};
+
+static int ip4_frags_ns_ctl_register(struct net *net)
+{
+ struct ctl_table *table;
+ struct ctl_table_header *hdr;
+
+ table = ip4_frags_ns_ctl_table;
+ if (!net_eq(net, &init_net)) {
+ table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
+ if (table == NULL)
+ goto err_alloc;
+
+ table[0].data = &net->ipv4.frags.high_thresh;
+ table[1].data = &net->ipv4.frags.low_thresh;
+ table[2].data = &net->ipv4.frags.timeout;
+ }
+
+ hdr = register_net_sysctl_table(net, net_ipv4_ctl_path, table);
+ if (hdr == NULL)
+ goto err_reg;
+
+ net->ipv4.frags_hdr = hdr;
+ return 0;
+
+err_reg:
+ if (!net_eq(net, &init_net))
+ kfree(table);
+err_alloc:
+ return -ENOMEM;
+}
+
+static void ip4_frags_ns_ctl_unregister(struct net *net)
+{
+ struct ctl_table *table;
+
+ table = net->ipv4.frags_hdr->ctl_table_arg;
+ unregister_net_sysctl_table(net->ipv4.frags_hdr);
+ kfree(table);
+}
+
+static void ip4_frags_ctl_register(void)
+{
+ register_net_sysctl_rotable(net_ipv4_ctl_path, ip4_frags_ctl_table);
+}
+#else
+static inline int ip4_frags_ns_ctl_register(struct net *net)
+{
+ return 0;
+}
+
+static inline void ip4_frags_ns_ctl_unregister(struct net *net)
+{
+}
+
+static inline void ip4_frags_ctl_register(void)
+{
+}
+#endif
+
+static int ipv4_frags_init_net(struct net *net)
+{
+ /*
+ * Fragment cache limits. We will commit 256K at one time. Should we
+ * cross that limit we will prune down to 192K. This should cope with
+ * even the most extreme cases without allowing an attacker to
+ * measurably harm machine performance.
+ */
+ net->ipv4.frags.high_thresh = 256 * 1024;
+ net->ipv4.frags.low_thresh = 192 * 1024;
+ /*
+ * Important NOTE! Fragment queue must be destroyed before MSL expires.
+ * RFC791 is wrong proposing to prolongate timer each fragment arrival
+ * by TTL.
+ */
+ net->ipv4.frags.timeout = IP_FRAG_TIME;
+
+ inet_frags_init_net(&net->ipv4.frags);
+
+ return ip4_frags_ns_ctl_register(net);
+}
+
+static void ipv4_frags_exit_net(struct net *net)
+{
+ ip4_frags_ns_ctl_unregister(net);
+ inet_frags_exit_net(&net->ipv4.frags, &ip4_frags);
+}
+
+static struct pernet_operations ip4_frags_ops = {
+ .init = ipv4_frags_init_net,
+ .exit = ipv4_frags_exit_net,
+};
+
void __init ipfrag_init(void)
{
- ip4_frags.ctl = &ip4_frags_ctl;
+ ip4_frags_ctl_register();
+ register_pernet_subsys(&ip4_frags_ops);
ip4_frags.hashfn = ip4_hashfn;
+ ip4_frags.constructor = ip4_frag_init;
ip4_frags.destructor = ip4_frag_free;
ip4_frags.skb_free = NULL;
ip4_frags.qsize = sizeof(struct ipq);
+ ip4_frags.match = ip4_frag_match;
+ ip4_frags.frag_expire = ip_expire;
+ ip4_frags.secret_interval = 10 * 60 * HZ;
inet_frags_init(&ip4_frags);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff