* The IP fragmentation functionality.
*
* 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.
#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>
#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
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 {
__be32 daddr;
__be16 id;
u8 protocol;
+ u8 ecn; /* RFC3168 support */
int iif;
unsigned int rid;
struct inet_peer *peer;
};
+/* RFC 3168 support :
+ * We want to check ECN values of all fragments, do detect invalid combinations.
+ * In ipq->ecn, we store the OR value of each ip4_frag_ecn() fragment value.
+ */
+#define IPFRAG_ECN_NOT_ECT 0x01 /* one frag had ECN_NOT_ECT */
+#define IPFRAG_ECN_ECT_1 0x02 /* one frag had ECN_ECT_1 */
+#define IPFRAG_ECN_ECT_0 0x04 /* one frag had ECN_ECT_0 */
+#define IPFRAG_ECN_CE 0x08 /* one frag had ECN_CE */
+
+static inline u8 ip4_frag_ecn(u8 tos)
+{
+ return 1 << (tos & INET_ECN_MASK);
+}
+
+/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
+ * Value : 0xff if frame should be dropped.
+ * 0 or INET_ECN_CE value, to be ORed in to final iph->tos field
+ */
+static const u8 ip4_frag_ecn_table[16] = {
+ /* at least one fragment had CE, and others ECT_0 or ECT_1 */
+ [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = INET_ECN_CE,
+ [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
+ [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
+
+ /* invalid combinations : drop frame */
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
+};
+
static struct inet_frags ip4_frags;
int ip_frag_nqueues(struct net *net)
struct ip4_create_arg *arg = a;
qp = container_of(q, struct ipq, q);
- return (qp->id == arg->iph->id &&
+ 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);
+ qp->user == arg->user;
}
/* Memory Tracking Functions. */
-static __inline__ void frag_kfree_skb(struct netns_frags *nf,
- struct sk_buff *skb, int *work)
+static void frag_kfree_skb(struct netns_frags *nf, struct sk_buff *skb)
{
- if (work)
- *work -= skb->truesize;
atomic_sub(skb->truesize, &nf->mem);
kfree_skb(skb);
}
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(arg->iph->saddr, 1) : NULL;
}
static __inline__ void ip4_frag_free(struct inet_frag_queue *q)
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);
}
/*
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 dst is stale, drop it, and perform route lookup again */
+ skb_dst_drop(head);
+ 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 &&
+ 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(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);
fp = qp->q.fragments;
do {
struct sk_buff *xp = fp->next;
- frag_kfree_skb(qp->q.net, fp, NULL);
+ frag_kfree_skb(qp->q.net, fp);
fp = xp;
} while (fp);
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;
}
int flags, offset;
int ihl, end;
int err = -ENOENT;
+ u8 ecn;
if (qp->q.last_in & INET_FRAG_COMPLETE)
goto err;
goto err;
}
+ ecn = ip4_frag_ecn(ip_hdr(skb)->tos);
offset = ntohs(ip_hdr(skb)->frag_off);
flags = offset & ~IP_OFFSET;
offset &= IP_OFFSET;
* 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)
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.
qp->q.fragments = next;
qp->q.meat -= free_it->len;
- frag_kfree_skb(qp->q.net, free_it, NULL);
+ frag_kfree_skb(qp->q.net, free_it);
}
}
/* Insert this fragment in the chain of fragments. */
skb->next = next;
+ if (!next)
+ qp->q.fragments_tail = skb;
if (prev)
prev->next = skb;
else
}
qp->q.stamp = skb->tstamp;
qp->q.meat += skb->len;
+ qp->ecn |= ecn;
atomic_add(skb->truesize, &qp->q.net->mem);
if (offset == 0)
qp->q.last_in |= INET_FRAG_FIRST_IN;
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;
+ u8 ecn;
ipq_kill(qp);
+ ecn = ip4_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;
goto out_nomem;
fp->next = head->next;
+ if (!fp->next)
+ qp->q.fragments_tail = fp;
prev->next = fp;
skb_morph(head, 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);
/* 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;
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;
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;
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);
}
+ atomic_sub(head->truesize, &qp->q.net->mem);
head->next = NULL;
head->dev = dev;
iph = ip_hdr(head);
iph->frag_off = 0;
iph->tot_len = htons(len);
- IP_INC_STATS_BH(dev_net(dev), 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:
goto out_fail;
out_oversize:
if (net_ratelimit())
- printk(KERN_INFO
- "Oversized IP packet from " NIPQUAD_FMT ".\n",
- NIPQUAD(qp->saddr));
+ printk(KERN_INFO "Oversized IP packet from %pI4.\n",
+ &qp->saddr);
out_fail:
- IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_REASMFAILS);
+ IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
return err;
}
struct ipq *qp;
struct net *net;
- net = skb->dev ? dev_net(skb->dev) : dev_net(skb->dst->dev);
+ 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. */
kfree_skb(skb);
return -ENOMEM;
}
+EXPORT_SYMBOL(ip_defrag);
+
+struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
+{
+ const struct iphdr *iph;
+ u32 len;
+
+ if (skb->protocol != htons(ETH_P_IP))
+ return skb;
+
+ if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+ return skb;
+
+ iph = ip_hdr(skb);
+ if (iph->ihl < 5 || iph->version != 4)
+ return skb;
+ if (!pskb_may_pull(skb, iph->ihl*4))
+ return skb;
+ iph = ip_hdr(skb);
+ len = ntohs(iph->tot_len);
+ if (skb->len < len || len < (iph->ihl * 4))
+ return skb;
+
+ if (ip_is_fragment(ip_hdr(skb))) {
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (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->rxhash = 0;
+ }
+ }
+ return skb;
+}
+EXPORT_SYMBOL(ip_check_defrag);
#ifdef CONFIG_SYSCTL
static int zero;
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_ns_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_ns_ctl_table;
- if (net != &init_net) {
+ if (!net_eq(net, &init_net)) {
table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
if (table == NULL)
goto err_alloc;
return 0;
err_reg:
- if (net != &init_net)
+ if (!net_eq(net, &init_net))
kfree(table);
err_alloc:
return -ENOMEM;
}
-static void ip4_frags_ns_ctl_unregister(struct net *net)
+static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
{
struct ctl_table *table;
}
#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
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_ns_ctl_unregister(net);
inet_frags_exit_net(&net->ipv4.frags, &ip4_frags);
ip4_frags.secret_interval = 10 * 60 * HZ;
inet_frags_init(&ip4_frags);
}
-
-EXPORT_SYMBOL(ip_defrag);
projects / linux-2.6.git / blobdiff