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Diffstat (limited to 'net/ipv4/ip_fragment.c')
-rw-r--r--net/ipv4/ip_fragment.c377
1 files changed, 257 insertions, 120 deletions
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 3b2e5adca83..ed32313e307 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -5,10 +5,8 @@
*
* 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.
@@ -22,6 +20,8 @@
* Patrick McHardy : LRU queue of frag heads for evictor.
*/
+#define pr_fmt(fmt) "IPv4: " fmt
+
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/types.h>
@@ -34,6 +34,9 @@
#include <linux/netdevice.h>
#include <linux/jhash.h>
#include <linux/random.h>
+#include <linux/slab.h>
+#include <net/route.h>
+#include <net/dst.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/icmp.h>
@@ -44,6 +47,7 @@
#include <linux/udp.h>
#include <linux/inet.h>
#include <linux/netfilter_ipv4.h>
+#include <net/inet_ecn.h>
/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
* code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
@@ -58,7 +62,7 @@ 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 {
@@ -69,11 +73,17 @@ struct ipq {
__be32 daddr;
__be16 id;
u8 protocol;
+ u8 ecn; /* RFC3168 support */
int iif;
unsigned int rid;
struct inet_peer *peer;
};
+static inline u8 ip4_frag_ecn(u8 tos)
+{
+ return 1 << (tos & INET_ECN_MASK);
+}
+
static struct inet_frags ip4_frags;
int ip_frag_nqueues(struct net *net)
@@ -83,7 +93,7 @@ int ip_frag_nqueues(struct net *net)
int ip_frag_mem(struct net *net)
{
- return atomic_read(&net->ipv4.frags.mem);
+ return sum_frag_mem_limit(&net->ipv4.frags);
}
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
@@ -96,6 +106,7 @@ struct ip4_create_arg {
static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
{
+ net_get_random_once(&ip4_frags.rnd, sizeof(ip4_frags.rnd));
return jhash_3words((__force u32)id << 16 | prot,
(__force u32)saddr, (__force u32)daddr,
ip4_frags.rnd) & (INETFRAGS_HASHSZ - 1);
@@ -109,41 +120,36 @@ static unsigned int ip4_hashfn(struct inet_frag_queue *q)
return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol);
}
-static int ip4_frag_match(struct inet_frag_queue *q, void *a)
+static bool 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 netns_frags *nf,
- struct sk_buff *skb, int *work)
-{
- if (work)
- *work -= skb->truesize;
- atomic_sub(skb->truesize, &nf->mem);
- kfree_skb(skb);
+ 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;
}
static void ip4_frag_init(struct inet_frag_queue *q, void *a)
{
struct ipq *qp = container_of(q, struct ipq, q);
+ struct netns_ipv4 *ipv4 = container_of(q->net, struct netns_ipv4,
+ frags);
+ struct net *net = container_of(ipv4, struct net, ipv4);
+
struct ip4_create_arg *arg = a;
qp->protocol = arg->iph->protocol;
qp->id = arg->iph->id;
+ qp->ecn = ip4_frag_ecn(arg->iph->tos);
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;
+ inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, 1) : NULL;
}
static __inline__ void ip4_frag_free(struct inet_frag_queue *q)
@@ -178,9 +184,9 @@ static void ip_evictor(struct net *net)
{
int evicted;
- evicted = inet_frag_evictor(&net->ipv4.frags, &ip4_frags);
+ evicted = inet_frag_evictor(&net->ipv4.frags, &ip4_frags, false);
if (evicted)
- IP_ADD_STATS_BH(IPSTATS_MIB_REASMFAILS, evicted);
+ IP_ADD_STATS_BH(net, IPSTATS_MIB_REASMFAILS, evicted);
}
/*
@@ -189,26 +195,53 @@ static void ip_evictor(struct net *net)
static void ip_expire(unsigned long 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;
+ const struct iphdr *iph;
+ int err;
+
+ rcu_read_lock();
+ head->dev = dev_get_by_index_rcu(net, qp->iif);
+ if (!head->dev)
+ goto out_rcu_unlock;
+
+ /* skb has no dst, perform route lookup again */
+ iph = ip_hdr(head);
+ err = ip_route_input_noref(head, iph->daddr, iph->saddr,
+ iph->tos, head->dev);
+ if (err)
+ goto out_rcu_unlock;
+
+ /*
+ * Only an end host needs to send an ICMP
+ * "Fragment Reassembly Timeout" message, per RFC792.
+ */
+ if (qp->user == IP_DEFRAG_AF_PACKET ||
+ ((qp->user >= IP_DEFRAG_CONNTRACK_IN) &&
+ (qp->user <= __IP_DEFRAG_CONNTRACK_IN_END) &&
+ (skb_rtable(head)->rt_type != RTN_LOCAL)))
+ goto out_rcu_unlock;
+
+
/* Send an ICMP "Fragment Reassembly Timeout" message. */
- if ((head->dev = dev_get_by_index(&init_net, qp->iif)) != NULL) {
- icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
- dev_put(head->dev);
- }
+ icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
+out_rcu_unlock:
+ rcu_read_unlock();
}
out:
spin_unlock(&qp->q.lock);
@@ -226,17 +259,16 @@ static inline struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user)
arg.iph = iph;
arg.user = user;
+
+ read_lock(&ip4_frags.lock);
hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash);
- if (q == NULL)
- goto out_nomem;
-
+ if (IS_ERR_OR_NULL(q)) {
+ inet_frag_maybe_warn_overflow(q, pr_fmt());
+ return NULL;
+ }
return container_of(q, struct ipq, q);
-
-out_nomem:
- LIMIT_NETDEBUG(KERN_ERR "ip_frag_create: no memory left !\n");
- return NULL;
}
/* Is the fragment too far ahead to be part of ipq? */
@@ -258,7 +290,10 @@ 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;
@@ -267,6 +302,7 @@ static inline int ip_frag_too_far(struct ipq *qp)
static int ip_frag_reinit(struct ipq *qp)
{
struct sk_buff *fp;
+ unsigned int sum_truesize = 0;
if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
atomic_inc(&qp->q.refcnt);
@@ -276,15 +312,20 @@ static int ip_frag_reinit(struct ipq *qp)
fp = qp->q.fragments;
do {
struct sk_buff *xp = fp->next;
- frag_kfree_skb(qp->q.net, fp, NULL);
+
+ sum_truesize += fp->truesize;
+ kfree_skb(fp);
fp = xp;
} while (fp);
+ sub_frag_mem_limit(&qp->q, sum_truesize);
qp->q.last_in = 0;
qp->q.len = 0;
qp->q.meat = 0;
qp->q.fragments = NULL;
+ qp->q.fragments_tail = NULL;
qp->iif = 0;
+ qp->ecn = 0;
return 0;
}
@@ -297,8 +338,9 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
int flags, offset;
int ihl, end;
int err = -ENOENT;
+ u8 ecn;
- if (qp->q.last_in & COMPLETE)
+ if (qp->q.last_in & INET_FRAG_COMPLETE)
goto err;
if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
@@ -308,6 +350,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
goto err;
}
+ ecn = ip4_frag_ecn(ip_hdr(skb)->tos);
offset = ntohs(ip_hdr(skb)->frag_off);
flags = offset & ~IP_OFFSET;
offset &= IP_OFFSET;
@@ -321,12 +364,12 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
/* Is this the final fragment? */
if ((flags & IP_MF) == 0) {
/* If we already have some bits beyond end
- * or have different end, the segment is corrrupted.
+ * or have different end, the segment is corrupted.
*/
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) {
@@ -336,7 +379,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
}
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;
}
@@ -356,6 +399,11 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
* in the chain of fragments so far. We must know where to put
* this fragment, right?
*/
+ prev = qp->q.fragments_tail;
+ if (!prev || FRAG_CB(prev)->offset < offset) {
+ next = NULL;
+ goto found;
+ }
prev = NULL;
for (next = qp->q.fragments; next != NULL; next = next->next) {
if (FRAG_CB(next)->offset >= offset)
@@ -363,6 +411,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
prev = next;
}
+found:
/* We found where to put this one. Check for overlap with
* preceding fragment, and, if needed, align things so that
* any overlaps are eliminated.
@@ -413,7 +462,8 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
qp->q.fragments = next;
qp->q.meat -= free_it->len;
- frag_kfree_skb(qp->q.net, free_it, NULL);
+ sub_frag_mem_limit(&qp->q, free_it->truesize);
+ kfree_skb(free_it);
}
}
@@ -421,6 +471,8 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
/* Insert this fragment in the chain of fragments. */
skb->next = next;
+ if (!next)
+ qp->q.fragments_tail = skb;
if (prev)
prev->next = skb;
else
@@ -433,16 +485,27 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
}
qp->q.stamp = skb->tstamp;
qp->q.meat += skb->len;
- atomic_add(skb->truesize, &qp->q.net->mem);
+ qp->ecn |= ecn;
+ add_frag_mem_limit(&qp->q, skb->truesize);
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)
- return ip_frag_reasm(qp, prev, dev);
+ if (ip_hdr(skb)->frag_off & htons(IP_DF) &&
+ skb->len + ihl > qp->q.max_size)
+ qp->q.max_size = skb->len + ihl;
+
+ if (qp->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
+ qp->q.meat == qp->q.len) {
+ unsigned long orefdst = skb->_skb_refdst;
+
+ skb->_skb_refdst = 0UL;
+ err = ip_frag_reasm(qp, prev, dev);
+ skb->_skb_refdst = orefdst;
+ return err;
+ }
- write_lock(&ip4_frags.lock);
- list_move_tail(&qp->q.lru_list, &qp->q.net->lru_list);
- write_unlock(&ip4_frags.lock);
+ skb_dst_drop(skb);
+ inet_frag_lru_move(&qp->q);
return -EINPROGRESS;
err:
@@ -456,14 +519,22 @@ err:
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;
int ihlen;
int err;
+ int sum_truesize;
+ u8 ecn;
ipq_kill(qp);
+ ecn = ip_frag_ecn_table[qp->ecn];
+ if (unlikely(ecn == 0xff)) {
+ err = -EINVAL;
+ goto out_fail;
+ }
/* Make the one we just received the head. */
if (prev) {
head = prev->next;
@@ -472,17 +543,19 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
goto out_nomem;
fp->next = head->next;
+ if (!fp->next)
+ qp->q.fragments_tail = fp;
prev->next = fp;
skb_morph(head, qp->q.fragments);
head->next = qp->q.fragments->next;
- kfree_skb(qp->q.fragments);
+ consume_skb(qp->q.fragments);
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);
@@ -493,13 +566,13 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
goto out_oversize;
/* Head of list must not be cloned. */
- if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
+ if (skb_unclone(head, 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_frag_list(head)) {
struct sk_buff *clone;
int i, plen = 0;
@@ -508,55 +581,68 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
clone->next = head->next;
head->next = clone;
skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
- skb_shinfo(head)->frag_list = NULL;
- for (i=0; i<skb_shinfo(head)->nr_frags; i++)
- plen += skb_shinfo(head)->frags[i].size;
+ skb_frag_list_init(head);
+ for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
+ plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
clone->len = clone->data_len = head->data_len - plen;
head->data_len -= clone->len;
head->len -= clone->len;
clone->csum = 0;
clone->ip_summed = head->ip_summed;
- atomic_add(clone->truesize, &qp->q.net->mem);
+ add_frag_mem_limit(&qp->q, clone->truesize);
}
- skb_shinfo(head)->frag_list = head->next;
skb_push(head, head->data - skb_network_header(head));
- atomic_sub(head->truesize, &qp->q.net->mem);
- for (fp=head->next; fp; fp = fp->next) {
- head->data_len += fp->len;
- head->len += fp->len;
+ sum_truesize = head->truesize;
+ for (fp = head->next; fp;) {
+ bool headstolen;
+ int delta;
+ struct sk_buff *next = fp->next;
+
+ sum_truesize += fp->truesize;
if (head->ip_summed != fp->ip_summed)
head->ip_summed = CHECKSUM_NONE;
else if (head->ip_summed == CHECKSUM_COMPLETE)
head->csum = csum_add(head->csum, fp->csum);
- head->truesize += fp->truesize;
- atomic_sub(fp->truesize, &qp->q.net->mem);
+
+ if (skb_try_coalesce(head, fp, &headstolen, &delta)) {
+ kfree_skb_partial(fp, headstolen);
+ } else {
+ if (!skb_shinfo(head)->frag_list)
+ skb_shinfo(head)->frag_list = fp;
+ head->data_len += fp->len;
+ head->len += fp->len;
+ head->truesize += fp->truesize;
+ }
+ fp = next;
}
+ sub_frag_mem_limit(&qp->q, sum_truesize);
head->next = NULL;
head->dev = dev;
head->tstamp = qp->q.stamp;
+ IPCB(head)->frag_max_size = qp->q.max_size;
iph = ip_hdr(head);
- iph->frag_off = 0;
+ /* max_size != 0 implies at least one fragment had IP_DF set */
+ iph->frag_off = qp->q.max_size ? htons(IP_DF) : 0;
iph->tot_len = htons(len);
- IP_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
+ iph->tos |= ecn;
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);
qp->q.fragments = NULL;
+ qp->q.fragments_tail = NULL;
return 0;
out_nomem:
- LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing "
- "queue %p\n", qp);
+ LIMIT_NETDEBUG(KERN_ERR pr_fmt("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));
+ net_info_ratelimited("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;
}
@@ -566,12 +652,11 @@ 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);
- net = skb->dev ? skb->dev->nd_net : skb->dst->dev->nd_net;
/* Start by cleaning up the memory. */
- if (atomic_read(&net->ipv4.frags.mem) > net->ipv4.frags.high_thresh)
- ip_evictor(net);
+ ip_evictor(net);
/* Lookup (or create) queue header */
if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
@@ -586,79 +671,115 @@ int ip_defrag(struct sk_buff *skb, u32 user)
return ret;
}
- IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
kfree_skb(skb);
return -ENOMEM;
}
+EXPORT_SYMBOL(ip_defrag);
+
+struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
+{
+ struct iphdr iph;
+ u32 len;
+
+ if (skb->protocol != htons(ETH_P_IP))
+ return skb;
+
+ if (!skb_copy_bits(skb, 0, &iph, sizeof(iph)))
+ return skb;
+
+ if (iph.ihl < 5 || iph.version != 4)
+ return skb;
+
+ len = ntohs(iph.tot_len);
+ if (skb->len < len || len < (iph.ihl * 4))
+ return skb;
+
+ if (ip_is_fragment(&iph)) {
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (skb) {
+ if (!pskb_may_pull(skb, iph.ihl*4))
+ return skb;
+ if (pskb_trim_rcsum(skb, len))
+ return skb;
+ memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
+ if (ip_defrag(skb, user))
+ return NULL;
+ skb_clear_hash(skb);
+ }
+ }
+ return skb;
+}
+EXPORT_SYMBOL(ip_check_defrag);
#ifdef CONFIG_SYSCTL
static int zero;
-static struct ctl_table ip4_frags_ctl_table[] = {
+static struct ctl_table ip4_frags_ns_ctl_table[] = {
{
- .ctl_name = NET_IPV4_IPFRAG_HIGH_THRESH,
.procname = "ipfrag_high_thresh",
.data = &init_net.ipv4.frags.high_thresh,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec
+ .proc_handler = proc_dointvec
},
{
- .ctl_name = NET_IPV4_IPFRAG_LOW_THRESH,
.procname = "ipfrag_low_thresh",
.data = &init_net.ipv4.frags.low_thresh,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec
+ .proc_handler = proc_dointvec
},
{
- .ctl_name = NET_IPV4_IPFRAG_TIME,
.procname = "ipfrag_time",
.data = &init_net.ipv4.frags.timeout,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec_jiffies,
- .strategy = &sysctl_jiffies
+ .proc_handler = proc_dointvec_jiffies,
},
+ { }
+};
+
+static struct ctl_table ip4_frags_ctl_table[] = {
{
- .ctl_name = NET_IPV4_IPFRAG_SECRET_INTERVAL,
.procname = "ipfrag_secret_interval",
.data = &ip4_frags.secret_interval,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec_jiffies,
- .strategy = &sysctl_jiffies
+ .proc_handler = proc_dointvec_jiffies,
},
{
.procname = "ipfrag_max_dist",
.data = &sysctl_ipfrag_max_dist,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
+ .proc_handler = proc_dointvec_minmax,
.extra1 = &zero
},
{ }
};
-static int ip4_frags_ctl_register(struct net *net)
+static int __net_init ip4_frags_ns_ctl_register(struct net *net)
{
struct ctl_table *table;
struct ctl_table_header *hdr;
- table = ip4_frags_ctl_table;
- if (net != &init_net) {
- table = kmemdup(table, sizeof(ip4_frags_ctl_table), GFP_KERNEL);
+ 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;
- table[3].mode &= ~0222;
- table[4].mode &= ~0222;
+
+ /* Don't export sysctls to unprivileged users */
+ if (net->user_ns != &init_user_ns)
+ table[0].procname = NULL;
}
- hdr = register_net_sysctl_table(net, net_ipv4_ctl_path, table);
+ hdr = register_net_sysctl(net, "net/ipv4", table);
if (hdr == NULL)
goto err_reg;
@@ -666,13 +787,13 @@ static int ip4_frags_ctl_register(struct net *net)
return 0;
err_reg:
- if (net != &init_net)
+ if (!net_eq(net, &init_net))
kfree(table);
err_alloc:
return -ENOMEM;
}
-static void ip4_frags_ctl_unregister(struct net *net)
+static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
{
struct ctl_table *table;
@@ -680,27 +801,44 @@ static void ip4_frags_ctl_unregister(struct net *net)
unregister_net_sysctl_table(net->ipv4.frags_hdr);
kfree(table);
}
+
+static void ip4_frags_ctl_register(void)
+{
+ register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table);
+}
#else
-static inline int ip4_frags_ctl_register(struct net *net)
+static inline int ip4_frags_ns_ctl_register(struct net *net)
{
return 0;
}
-static inline void ip4_frags_ctl_unregister(struct net *net)
+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)
+static int __net_init 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.
+ /* Fragment cache limits.
+ *
+ * The fragment memory accounting code, (tries to) account for
+ * the real memory usage, by measuring both the size of frag
+ * queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue))
+ * and the SKB's truesize.
+ *
+ * A 64K fragment consumes 129736 bytes (44*2944)+200
+ * (1500 truesize == 2944, sizeof(struct ipq) == 200)
+ *
+ * We will commit 4MB at one time. Should we cross that limit
+ * we will prune down to 3MB, making room for approx 8 big 64K
+ * fragments 8x128k.
*/
- net->ipv4.frags.high_thresh = 256 * 1024;
- net->ipv4.frags.low_thresh = 192 * 1024;
+ net->ipv4.frags.high_thresh = 4 * 1024 * 1024;
+ net->ipv4.frags.low_thresh = 3 * 1024 * 1024;
/*
* Important NOTE! Fragment queue must be destroyed before MSL expires.
* RFC791 is wrong proposing to prolongate timer each fragment arrival
@@ -710,12 +848,12 @@ static int ipv4_frags_init_net(struct net *net)
inet_frags_init_net(&net->ipv4.frags);
- return ip4_frags_ctl_register(net);
+ return ip4_frags_ns_ctl_register(net);
}
-static void ipv4_frags_exit_net(struct net *net)
+static void __net_exit ipv4_frags_exit_net(struct net *net)
{
- ip4_frags_ctl_unregister(net);
+ ip4_frags_ns_ctl_unregister(net);
inet_frags_exit_net(&net->ipv4.frags, &ip4_frags);
}
@@ -726,6 +864,7 @@ static struct pernet_operations ip4_frags_ops = {
void __init ipfrag_init(void)
{
+ ip4_frags_ctl_register();
register_pernet_subsys(&ip4_frags_ops);
ip4_frags.hashfn = ip4_hashfn;
ip4_frags.constructor = ip4_frag_init;
@@ -737,5 +876,3 @@ void __init ipfrag_init(void)
ip4_frags.secret_interval = 10 * 60 * HZ;
inet_frags_init(&ip4_frags);
}
-
-EXPORT_SYMBOL(ip_defrag);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 07:18:00 +0000