11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * INET An implementation of the TCP/IP protocol suite for the LINUX 31da177e4SLinus Torvalds * operating system. INET is implemented using the BSD Socket 41da177e4SLinus Torvalds * interface as the means of communication with the user level. 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * The IP fragmentation functionality. 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG> 9113aa838SAlan Cox * Alan Cox <alan@lxorguk.ukuu.org.uk> 101da177e4SLinus Torvalds * 111da177e4SLinus Torvalds * Fixes: 121da177e4SLinus Torvalds * Alan Cox : Split from ip.c , see ip_input.c for history. 131da177e4SLinus Torvalds * David S. Miller : Begin massive cleanup... 141da177e4SLinus Torvalds * Andi Kleen : Add sysctls. 151da177e4SLinus Torvalds * xxxx : Overlapfrag bug. 161da177e4SLinus Torvalds * Ultima : ip_expire() kernel panic. 171da177e4SLinus Torvalds * Bill Hawes : Frag accounting and evictor fixes. 181da177e4SLinus Torvalds * John McDonald : 0 length frag bug. 191da177e4SLinus Torvalds * Alexey Kuznetsov: SMP races, threading, cleanup. 201da177e4SLinus Torvalds * Patrick McHardy : LRU queue of frag heads for evictor. 211da177e4SLinus Torvalds */ 221da177e4SLinus Torvalds 2389cee8b1SHerbert Xu #include <linux/compiler.h> 241da177e4SLinus Torvalds #include <linux/module.h> 251da177e4SLinus Torvalds #include <linux/types.h> 261da177e4SLinus Torvalds #include <linux/mm.h> 271da177e4SLinus Torvalds #include <linux/jiffies.h> 281da177e4SLinus Torvalds #include <linux/skbuff.h> 291da177e4SLinus Torvalds #include <linux/list.h> 301da177e4SLinus Torvalds #include <linux/ip.h> 311da177e4SLinus Torvalds #include <linux/icmp.h> 321da177e4SLinus Torvalds #include <linux/netdevice.h> 331da177e4SLinus Torvalds #include <linux/jhash.h> 341da177e4SLinus Torvalds #include <linux/random.h> 355a0e3ad6STejun Heo #include <linux/slab.h> 36e9017b55SShan Wei #include <net/route.h> 37e9017b55SShan Wei #include <net/dst.h> 381da177e4SLinus Torvalds #include <net/sock.h> 391da177e4SLinus Torvalds #include <net/ip.h> 401da177e4SLinus Torvalds #include <net/icmp.h> 411da177e4SLinus Torvalds #include <net/checksum.h> 4289cee8b1SHerbert Xu #include <net/inetpeer.h> 435ab11c98SPavel Emelyanov #include <net/inet_frag.h> 441da177e4SLinus Torvalds #include <linux/tcp.h> 451da177e4SLinus Torvalds #include <linux/udp.h> 461da177e4SLinus Torvalds #include <linux/inet.h> 471da177e4SLinus Torvalds #include <linux/netfilter_ipv4.h> 481da177e4SLinus Torvalds 491da177e4SLinus Torvalds /* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6 501da177e4SLinus Torvalds * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c 511da177e4SLinus Torvalds * as well. Or notify me, at least. --ANK 521da177e4SLinus Torvalds */ 531da177e4SLinus Torvalds 548d8354d2SPavel Emelyanov static int sysctl_ipfrag_max_dist __read_mostly = 64; 5589cee8b1SHerbert Xu 561da177e4SLinus Torvalds struct ipfrag_skb_cb 571da177e4SLinus Torvalds { 581da177e4SLinus Torvalds struct inet_skb_parm h; 591da177e4SLinus Torvalds int offset; 601da177e4SLinus Torvalds }; 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds #define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb)) 631da177e4SLinus Torvalds 641da177e4SLinus Torvalds /* Describe an entry in the "incomplete datagrams" queue. */ 651da177e4SLinus Torvalds struct ipq { 665ab11c98SPavel Emelyanov struct inet_frag_queue q; 675ab11c98SPavel Emelyanov 681da177e4SLinus Torvalds u32 user; 6918277770SAl Viro __be32 saddr; 7018277770SAl Viro __be32 daddr; 7118277770SAl Viro __be16 id; 721da177e4SLinus Torvalds u8 protocol; 7389cee8b1SHerbert Xu int iif; 7489cee8b1SHerbert Xu unsigned int rid; 7589cee8b1SHerbert Xu struct inet_peer *peer; 761da177e4SLinus Torvalds }; 771da177e4SLinus Torvalds 787eb95156SPavel Emelyanov static struct inet_frags ip4_frags; 791da177e4SLinus Torvalds 80e5a2bb84SPavel Emelyanov int ip_frag_nqueues(struct net *net) 817eb95156SPavel Emelyanov { 82e5a2bb84SPavel Emelyanov return net->ipv4.frags.nqueues; 837eb95156SPavel Emelyanov } 841da177e4SLinus Torvalds 856ddc0822SPavel Emelyanov int ip_frag_mem(struct net *net) 867eb95156SPavel Emelyanov { 876ddc0822SPavel Emelyanov return atomic_read(&net->ipv4.frags.mem); 887eb95156SPavel Emelyanov } 891da177e4SLinus Torvalds 901706d587SHerbert Xu static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, 911706d587SHerbert Xu struct net_device *dev); 921706d587SHerbert Xu 93c6fda282SPavel Emelyanov struct ip4_create_arg { 94c6fda282SPavel Emelyanov struct iphdr *iph; 95c6fda282SPavel Emelyanov u32 user; 96c6fda282SPavel Emelyanov }; 97c6fda282SPavel Emelyanov 9818277770SAl Viro static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot) 991da177e4SLinus Torvalds { 10018277770SAl Viro return jhash_3words((__force u32)id << 16 | prot, 10118277770SAl Viro (__force u32)saddr, (__force u32)daddr, 1027eb95156SPavel Emelyanov ip4_frags.rnd) & (INETFRAGS_HASHSZ - 1); 1031da177e4SLinus Torvalds } 1041da177e4SLinus Torvalds 105321a3a99SPavel Emelyanov static unsigned int ip4_hashfn(struct inet_frag_queue *q) 1061da177e4SLinus Torvalds { 107321a3a99SPavel Emelyanov struct ipq *ipq; 1081da177e4SLinus Torvalds 109321a3a99SPavel Emelyanov ipq = container_of(q, struct ipq, q); 110321a3a99SPavel Emelyanov return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol); 1111da177e4SLinus Torvalds } 1121da177e4SLinus Torvalds 113abd6523dSPavel Emelyanov static int ip4_frag_match(struct inet_frag_queue *q, void *a) 114abd6523dSPavel Emelyanov { 115abd6523dSPavel Emelyanov struct ipq *qp; 116abd6523dSPavel Emelyanov struct ip4_create_arg *arg = a; 117abd6523dSPavel Emelyanov 118abd6523dSPavel Emelyanov qp = container_of(q, struct ipq, q); 119a02cec21SEric Dumazet return qp->id == arg->iph->id && 120abd6523dSPavel Emelyanov qp->saddr == arg->iph->saddr && 121abd6523dSPavel Emelyanov qp->daddr == arg->iph->daddr && 122abd6523dSPavel Emelyanov qp->protocol == arg->iph->protocol && 123a02cec21SEric Dumazet qp->user == arg->user; 124abd6523dSPavel Emelyanov } 125abd6523dSPavel Emelyanov 1261da177e4SLinus Torvalds /* Memory Tracking Functions. */ 127a95d8c88SEric Dumazet static void frag_kfree_skb(struct netns_frags *nf, struct sk_buff *skb) 1281da177e4SLinus Torvalds { 1296ddc0822SPavel Emelyanov atomic_sub(skb->truesize, &nf->mem); 1301da177e4SLinus Torvalds kfree_skb(skb); 1311da177e4SLinus Torvalds } 1321da177e4SLinus Torvalds 133c6fda282SPavel Emelyanov static void ip4_frag_init(struct inet_frag_queue *q, void *a) 134c6fda282SPavel Emelyanov { 135c6fda282SPavel Emelyanov struct ipq *qp = container_of(q, struct ipq, q); 136c6fda282SPavel Emelyanov struct ip4_create_arg *arg = a; 137c6fda282SPavel Emelyanov 138c6fda282SPavel Emelyanov qp->protocol = arg->iph->protocol; 139c6fda282SPavel Emelyanov qp->id = arg->iph->id; 140c6fda282SPavel Emelyanov qp->saddr = arg->iph->saddr; 141c6fda282SPavel Emelyanov qp->daddr = arg->iph->daddr; 142c6fda282SPavel Emelyanov qp->user = arg->user; 143c6fda282SPavel Emelyanov qp->peer = sysctl_ipfrag_max_dist ? 144b534ecf1SDavid S. Miller inet_getpeer_v4(arg->iph->saddr, 1) : NULL; 145c6fda282SPavel Emelyanov } 146c6fda282SPavel Emelyanov 1471e4b8287SPavel Emelyanov static __inline__ void ip4_frag_free(struct inet_frag_queue *q) 1481da177e4SLinus Torvalds { 1491e4b8287SPavel Emelyanov struct ipq *qp; 1501e4b8287SPavel Emelyanov 1511e4b8287SPavel Emelyanov qp = container_of(q, struct ipq, q); 1521e4b8287SPavel Emelyanov if (qp->peer) 1531e4b8287SPavel Emelyanov inet_putpeer(qp->peer); 1541da177e4SLinus Torvalds } 1551da177e4SLinus Torvalds 1561da177e4SLinus Torvalds 1571da177e4SLinus Torvalds /* Destruction primitives. */ 1581da177e4SLinus Torvalds 1594b6cb5d8SPavel Emelyanov static __inline__ void ipq_put(struct ipq *ipq) 1601da177e4SLinus Torvalds { 161762cc408SPavel Emelyanov inet_frag_put(&ipq->q, &ip4_frags); 1621da177e4SLinus Torvalds } 1631da177e4SLinus Torvalds 1641da177e4SLinus Torvalds /* Kill ipq entry. It is not destroyed immediately, 1651da177e4SLinus Torvalds * because caller (and someone more) holds reference count. 1661da177e4SLinus Torvalds */ 1671da177e4SLinus Torvalds static void ipq_kill(struct ipq *ipq) 1681da177e4SLinus Torvalds { 169277e650dSPavel Emelyanov inet_frag_kill(&ipq->q, &ip4_frags); 1701da177e4SLinus Torvalds } 1711da177e4SLinus Torvalds 1721da177e4SLinus Torvalds /* Memory limiting on fragments. Evictor trashes the oldest 1731da177e4SLinus Torvalds * fragment queue until we are back under the threshold. 1741da177e4SLinus Torvalds */ 1756ddc0822SPavel Emelyanov static void ip_evictor(struct net *net) 1761da177e4SLinus Torvalds { 1778e7999c4SPavel Emelyanov int evicted; 1781da177e4SLinus Torvalds 1796ddc0822SPavel Emelyanov evicted = inet_frag_evictor(&net->ipv4.frags, &ip4_frags); 1808e7999c4SPavel Emelyanov if (evicted) 181c5346fe3SPavel Emelyanov IP_ADD_STATS_BH(net, IPSTATS_MIB_REASMFAILS, evicted); 1821da177e4SLinus Torvalds } 1831da177e4SLinus Torvalds 1841da177e4SLinus Torvalds /* 1851da177e4SLinus Torvalds * Oops, a fragment queue timed out. Kill it and send an ICMP reply. 1861da177e4SLinus Torvalds */ 1871da177e4SLinus Torvalds static void ip_expire(unsigned long arg) 1881da177e4SLinus Torvalds { 189e521db9dSPavel Emelyanov struct ipq *qp; 19084a3aa00SPavel Emelyanov struct net *net; 191e521db9dSPavel Emelyanov 192e521db9dSPavel Emelyanov qp = container_of((struct inet_frag_queue *) arg, struct ipq, q); 19384a3aa00SPavel Emelyanov net = container_of(qp->q.net, struct net, ipv4.frags); 1941da177e4SLinus Torvalds 1955ab11c98SPavel Emelyanov spin_lock(&qp->q.lock); 1961da177e4SLinus Torvalds 197bc578a54SJoe Perches if (qp->q.last_in & INET_FRAG_COMPLETE) 1981da177e4SLinus Torvalds goto out; 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds ipq_kill(qp); 2011da177e4SLinus Torvalds 2027c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT); 2037c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 2041da177e4SLinus Torvalds 205bc578a54SJoe Perches if ((qp->q.last_in & INET_FRAG_FIRST_IN) && qp->q.fragments != NULL) { 2065ab11c98SPavel Emelyanov struct sk_buff *head = qp->q.fragments; 207cb84663eSDenis V. Lunev 20869df9d59SEric Dumazet rcu_read_lock(); 20969df9d59SEric Dumazet head->dev = dev_get_by_index_rcu(net, qp->iif); 210e9017b55SShan Wei if (!head->dev) 211e9017b55SShan Wei goto out_rcu_unlock; 212e9017b55SShan Wei 213e9017b55SShan Wei /* 214e9017b55SShan Wei * Only search router table for the head fragment, 215e9017b55SShan Wei * when defraging timeout at PRE_ROUTING HOOK. 216e9017b55SShan Wei */ 217e9017b55SShan Wei if (qp->user == IP_DEFRAG_CONNTRACK_IN && !skb_dst(head)) { 218e9017b55SShan Wei const struct iphdr *iph = ip_hdr(head); 219e9017b55SShan Wei int err = ip_route_input(head, iph->daddr, iph->saddr, 220e9017b55SShan Wei iph->tos, head->dev); 221e9017b55SShan Wei if (unlikely(err)) 222e9017b55SShan Wei goto out_rcu_unlock; 223e9017b55SShan Wei 224e9017b55SShan Wei /* 225e9017b55SShan Wei * Only an end host needs to send an ICMP 226e9017b55SShan Wei * "Fragment Reassembly Timeout" message, per RFC792. 227e9017b55SShan Wei */ 228e9017b55SShan Wei if (skb_rtable(head)->rt_type != RTN_LOCAL) 229e9017b55SShan Wei goto out_rcu_unlock; 230e9017b55SShan Wei 2311da177e4SLinus Torvalds } 232e9017b55SShan Wei 233e9017b55SShan Wei /* Send an ICMP "Fragment Reassembly Timeout" message. */ 234e9017b55SShan Wei icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0); 235e9017b55SShan Wei out_rcu_unlock: 236e9017b55SShan Wei rcu_read_unlock(); 237d1c9ae6dSPatrick McHardy } 2381da177e4SLinus Torvalds out: 2395ab11c98SPavel Emelyanov spin_unlock(&qp->q.lock); 2404b6cb5d8SPavel Emelyanov ipq_put(qp); 2411da177e4SLinus Torvalds } 2421da177e4SLinus Torvalds 243abd6523dSPavel Emelyanov /* Find the correct entry in the "incomplete datagrams" queue for 244abd6523dSPavel Emelyanov * this IP datagram, and create new one, if nothing is found. 245abd6523dSPavel Emelyanov */ 246ac18e750SPavel Emelyanov static inline struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user) 2471da177e4SLinus Torvalds { 248c6fda282SPavel Emelyanov struct inet_frag_queue *q; 249c6fda282SPavel Emelyanov struct ip4_create_arg arg; 250abd6523dSPavel Emelyanov unsigned int hash; 2511da177e4SLinus Torvalds 252c6fda282SPavel Emelyanov arg.iph = iph; 253c6fda282SPavel Emelyanov arg.user = user; 2549a375803SPavel Emelyanov 2559a375803SPavel Emelyanov read_lock(&ip4_frags.lock); 256abd6523dSPavel Emelyanov hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol); 257c6fda282SPavel Emelyanov 258ac18e750SPavel Emelyanov q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash); 259c6fda282SPavel Emelyanov if (q == NULL) 2601da177e4SLinus Torvalds goto out_nomem; 2611da177e4SLinus Torvalds 262c6fda282SPavel Emelyanov return container_of(q, struct ipq, q); 2631da177e4SLinus Torvalds 2641da177e4SLinus Torvalds out_nomem: 26564ce2073SPatrick McHardy LIMIT_NETDEBUG(KERN_ERR "ip_frag_create: no memory left !\n"); 2661da177e4SLinus Torvalds return NULL; 2671da177e4SLinus Torvalds } 2681da177e4SLinus Torvalds 26989cee8b1SHerbert Xu /* Is the fragment too far ahead to be part of ipq? */ 27089cee8b1SHerbert Xu static inline int ip_frag_too_far(struct ipq *qp) 27189cee8b1SHerbert Xu { 27289cee8b1SHerbert Xu struct inet_peer *peer = qp->peer; 27389cee8b1SHerbert Xu unsigned int max = sysctl_ipfrag_max_dist; 27489cee8b1SHerbert Xu unsigned int start, end; 27589cee8b1SHerbert Xu 27689cee8b1SHerbert Xu int rc; 27789cee8b1SHerbert Xu 27889cee8b1SHerbert Xu if (!peer || !max) 27989cee8b1SHerbert Xu return 0; 28089cee8b1SHerbert Xu 28189cee8b1SHerbert Xu start = qp->rid; 28289cee8b1SHerbert Xu end = atomic_inc_return(&peer->rid); 28389cee8b1SHerbert Xu qp->rid = end; 28489cee8b1SHerbert Xu 2855ab11c98SPavel Emelyanov rc = qp->q.fragments && (end - start) > max; 28689cee8b1SHerbert Xu 28789cee8b1SHerbert Xu if (rc) { 2887c73a6faSPavel Emelyanov struct net *net; 2897c73a6faSPavel Emelyanov 2907c73a6faSPavel Emelyanov net = container_of(qp->q.net, struct net, ipv4.frags); 2917c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 29289cee8b1SHerbert Xu } 29389cee8b1SHerbert Xu 29489cee8b1SHerbert Xu return rc; 29589cee8b1SHerbert Xu } 29689cee8b1SHerbert Xu 29789cee8b1SHerbert Xu static int ip_frag_reinit(struct ipq *qp) 29889cee8b1SHerbert Xu { 29989cee8b1SHerbert Xu struct sk_buff *fp; 30089cee8b1SHerbert Xu 301b2fd5321SPavel Emelyanov if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) { 3025ab11c98SPavel Emelyanov atomic_inc(&qp->q.refcnt); 30389cee8b1SHerbert Xu return -ETIMEDOUT; 30489cee8b1SHerbert Xu } 30589cee8b1SHerbert Xu 3065ab11c98SPavel Emelyanov fp = qp->q.fragments; 30789cee8b1SHerbert Xu do { 30889cee8b1SHerbert Xu struct sk_buff *xp = fp->next; 309a95d8c88SEric Dumazet frag_kfree_skb(qp->q.net, fp); 31089cee8b1SHerbert Xu fp = xp; 31189cee8b1SHerbert Xu } while (fp); 31289cee8b1SHerbert Xu 3135ab11c98SPavel Emelyanov qp->q.last_in = 0; 3145ab11c98SPavel Emelyanov qp->q.len = 0; 3155ab11c98SPavel Emelyanov qp->q.meat = 0; 3165ab11c98SPavel Emelyanov qp->q.fragments = NULL; 317d6bebca9SChangli Gao qp->q.fragments_tail = NULL; 31889cee8b1SHerbert Xu qp->iif = 0; 31989cee8b1SHerbert Xu 32089cee8b1SHerbert Xu return 0; 32189cee8b1SHerbert Xu } 32289cee8b1SHerbert Xu 3231da177e4SLinus Torvalds /* Add new segment to existing queue. */ 3241706d587SHerbert Xu static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) 3251da177e4SLinus Torvalds { 3261da177e4SLinus Torvalds struct sk_buff *prev, *next; 3271706d587SHerbert Xu struct net_device *dev; 3281da177e4SLinus Torvalds int flags, offset; 3291da177e4SLinus Torvalds int ihl, end; 3301706d587SHerbert Xu int err = -ENOENT; 3311da177e4SLinus Torvalds 332bc578a54SJoe Perches if (qp->q.last_in & INET_FRAG_COMPLETE) 3331da177e4SLinus Torvalds goto err; 3341da177e4SLinus Torvalds 33589cee8b1SHerbert Xu if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) && 3361706d587SHerbert Xu unlikely(ip_frag_too_far(qp)) && 3371706d587SHerbert Xu unlikely(err = ip_frag_reinit(qp))) { 33889cee8b1SHerbert Xu ipq_kill(qp); 33989cee8b1SHerbert Xu goto err; 34089cee8b1SHerbert Xu } 34189cee8b1SHerbert Xu 342eddc9ec5SArnaldo Carvalho de Melo offset = ntohs(ip_hdr(skb)->frag_off); 3431da177e4SLinus Torvalds flags = offset & ~IP_OFFSET; 3441da177e4SLinus Torvalds offset &= IP_OFFSET; 3451da177e4SLinus Torvalds offset <<= 3; /* offset is in 8-byte chunks */ 346c9bdd4b5SArnaldo Carvalho de Melo ihl = ip_hdrlen(skb); 3471da177e4SLinus Torvalds 3481da177e4SLinus Torvalds /* Determine the position of this fragment. */ 3491da177e4SLinus Torvalds end = offset + skb->len - ihl; 3501706d587SHerbert Xu err = -EINVAL; 3511da177e4SLinus Torvalds 3521da177e4SLinus Torvalds /* Is this the final fragment? */ 3531da177e4SLinus Torvalds if ((flags & IP_MF) == 0) { 3541da177e4SLinus Torvalds /* If we already have some bits beyond end 3551da177e4SLinus Torvalds * or have different end, the segment is corrrupted. 3561da177e4SLinus Torvalds */ 3575ab11c98SPavel Emelyanov if (end < qp->q.len || 358bc578a54SJoe Perches ((qp->q.last_in & INET_FRAG_LAST_IN) && end != qp->q.len)) 3591da177e4SLinus Torvalds goto err; 360bc578a54SJoe Perches qp->q.last_in |= INET_FRAG_LAST_IN; 3615ab11c98SPavel Emelyanov qp->q.len = end; 3621da177e4SLinus Torvalds } else { 3631da177e4SLinus Torvalds if (end&7) { 3641da177e4SLinus Torvalds end &= ~7; 3651da177e4SLinus Torvalds if (skb->ip_summed != CHECKSUM_UNNECESSARY) 3661da177e4SLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 3671da177e4SLinus Torvalds } 3685ab11c98SPavel Emelyanov if (end > qp->q.len) { 3691da177e4SLinus Torvalds /* Some bits beyond end -> corruption. */ 370bc578a54SJoe Perches if (qp->q.last_in & INET_FRAG_LAST_IN) 3711da177e4SLinus Torvalds goto err; 3725ab11c98SPavel Emelyanov qp->q.len = end; 3731da177e4SLinus Torvalds } 3741da177e4SLinus Torvalds } 3751da177e4SLinus Torvalds if (end == offset) 3761da177e4SLinus Torvalds goto err; 3771da177e4SLinus Torvalds 3781706d587SHerbert Xu err = -ENOMEM; 3791da177e4SLinus Torvalds if (pskb_pull(skb, ihl) == NULL) 3801da177e4SLinus Torvalds goto err; 3811706d587SHerbert Xu 3821706d587SHerbert Xu err = pskb_trim_rcsum(skb, end - offset); 3831706d587SHerbert Xu if (err) 3841da177e4SLinus Torvalds goto err; 3851da177e4SLinus Torvalds 3861da177e4SLinus Torvalds /* Find out which fragments are in front and at the back of us 3871da177e4SLinus Torvalds * in the chain of fragments so far. We must know where to put 3881da177e4SLinus Torvalds * this fragment, right? 3891da177e4SLinus Torvalds */ 390d6bebca9SChangli Gao prev = qp->q.fragments_tail; 391d6bebca9SChangli Gao if (!prev || FRAG_CB(prev)->offset < offset) { 392d6bebca9SChangli Gao next = NULL; 393d6bebca9SChangli Gao goto found; 394d6bebca9SChangli Gao } 3951da177e4SLinus Torvalds prev = NULL; 3965ab11c98SPavel Emelyanov for (next = qp->q.fragments; next != NULL; next = next->next) { 3971da177e4SLinus Torvalds if (FRAG_CB(next)->offset >= offset) 3981da177e4SLinus Torvalds break; /* bingo! */ 3991da177e4SLinus Torvalds prev = next; 4001da177e4SLinus Torvalds } 4011da177e4SLinus Torvalds 402d6bebca9SChangli Gao found: 4031da177e4SLinus Torvalds /* We found where to put this one. Check for overlap with 4041da177e4SLinus Torvalds * preceding fragment, and, if needed, align things so that 4051da177e4SLinus Torvalds * any overlaps are eliminated. 4061da177e4SLinus Torvalds */ 4071da177e4SLinus Torvalds if (prev) { 4081da177e4SLinus Torvalds int i = (FRAG_CB(prev)->offset + prev->len) - offset; 4091da177e4SLinus Torvalds 4101da177e4SLinus Torvalds if (i > 0) { 4111da177e4SLinus Torvalds offset += i; 4121706d587SHerbert Xu err = -EINVAL; 4131da177e4SLinus Torvalds if (end <= offset) 4141da177e4SLinus Torvalds goto err; 4151706d587SHerbert Xu err = -ENOMEM; 4161da177e4SLinus Torvalds if (!pskb_pull(skb, i)) 4171da177e4SLinus Torvalds goto err; 4181da177e4SLinus Torvalds if (skb->ip_summed != CHECKSUM_UNNECESSARY) 4191da177e4SLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 4201da177e4SLinus Torvalds } 4211da177e4SLinus Torvalds } 4221da177e4SLinus Torvalds 4231706d587SHerbert Xu err = -ENOMEM; 4241706d587SHerbert Xu 4251da177e4SLinus Torvalds while (next && FRAG_CB(next)->offset < end) { 4261da177e4SLinus Torvalds int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */ 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds if (i < next->len) { 4291da177e4SLinus Torvalds /* Eat head of the next overlapped fragment 4301da177e4SLinus Torvalds * and leave the loop. The next ones cannot overlap. 4311da177e4SLinus Torvalds */ 4321da177e4SLinus Torvalds if (!pskb_pull(next, i)) 4331da177e4SLinus Torvalds goto err; 4341da177e4SLinus Torvalds FRAG_CB(next)->offset += i; 4355ab11c98SPavel Emelyanov qp->q.meat -= i; 4361da177e4SLinus Torvalds if (next->ip_summed != CHECKSUM_UNNECESSARY) 4371da177e4SLinus Torvalds next->ip_summed = CHECKSUM_NONE; 4381da177e4SLinus Torvalds break; 4391da177e4SLinus Torvalds } else { 4401da177e4SLinus Torvalds struct sk_buff *free_it = next; 4411da177e4SLinus Torvalds 44247c6bf77SPeter Zijlstra /* Old fragment is completely overridden with 4431da177e4SLinus Torvalds * new one drop it. 4441da177e4SLinus Torvalds */ 4451da177e4SLinus Torvalds next = next->next; 4461da177e4SLinus Torvalds 4471da177e4SLinus Torvalds if (prev) 4481da177e4SLinus Torvalds prev->next = next; 4491da177e4SLinus Torvalds else 4505ab11c98SPavel Emelyanov qp->q.fragments = next; 4511da177e4SLinus Torvalds 4525ab11c98SPavel Emelyanov qp->q.meat -= free_it->len; 453a95d8c88SEric Dumazet frag_kfree_skb(qp->q.net, free_it); 4541da177e4SLinus Torvalds } 4551da177e4SLinus Torvalds } 4561da177e4SLinus Torvalds 4571da177e4SLinus Torvalds FRAG_CB(skb)->offset = offset; 4581da177e4SLinus Torvalds 4591da177e4SLinus Torvalds /* Insert this fragment in the chain of fragments. */ 4601da177e4SLinus Torvalds skb->next = next; 461d6bebca9SChangli Gao if (!next) 462d6bebca9SChangli Gao qp->q.fragments_tail = skb; 4631da177e4SLinus Torvalds if (prev) 4641da177e4SLinus Torvalds prev->next = skb; 4651da177e4SLinus Torvalds else 4665ab11c98SPavel Emelyanov qp->q.fragments = skb; 4671da177e4SLinus Torvalds 4681706d587SHerbert Xu dev = skb->dev; 4691706d587SHerbert Xu if (dev) { 4701706d587SHerbert Xu qp->iif = dev->ifindex; 4711da177e4SLinus Torvalds skb->dev = NULL; 4721706d587SHerbert Xu } 4735ab11c98SPavel Emelyanov qp->q.stamp = skb->tstamp; 4745ab11c98SPavel Emelyanov qp->q.meat += skb->len; 4756ddc0822SPavel Emelyanov atomic_add(skb->truesize, &qp->q.net->mem); 4761da177e4SLinus Torvalds if (offset == 0) 477bc578a54SJoe Perches qp->q.last_in |= INET_FRAG_FIRST_IN; 4781da177e4SLinus Torvalds 479bc578a54SJoe Perches if (qp->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 480bc578a54SJoe Perches qp->q.meat == qp->q.len) 4811706d587SHerbert Xu return ip_frag_reasm(qp, prev, dev); 4821706d587SHerbert Xu 4837eb95156SPavel Emelyanov write_lock(&ip4_frags.lock); 4843140c25cSPavel Emelyanov list_move_tail(&qp->q.lru_list, &qp->q.net->lru_list); 4857eb95156SPavel Emelyanov write_unlock(&ip4_frags.lock); 4861706d587SHerbert Xu return -EINPROGRESS; 4871da177e4SLinus Torvalds 4881da177e4SLinus Torvalds err: 4891da177e4SLinus Torvalds kfree_skb(skb); 4901706d587SHerbert Xu return err; 4911da177e4SLinus Torvalds } 4921da177e4SLinus Torvalds 4931da177e4SLinus Torvalds 4941da177e4SLinus Torvalds /* Build a new IP datagram from all its fragments. */ 4951da177e4SLinus Torvalds 4961706d587SHerbert Xu static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, 4971706d587SHerbert Xu struct net_device *dev) 4981da177e4SLinus Torvalds { 4992bad35b7SJorge Boncompte [DTI2] struct net *net = container_of(qp->q.net, struct net, ipv4.frags); 5001da177e4SLinus Torvalds struct iphdr *iph; 5015ab11c98SPavel Emelyanov struct sk_buff *fp, *head = qp->q.fragments; 5021da177e4SLinus Torvalds int len; 5031da177e4SLinus Torvalds int ihlen; 5041706d587SHerbert Xu int err; 5051da177e4SLinus Torvalds 5061da177e4SLinus Torvalds ipq_kill(qp); 5071da177e4SLinus Torvalds 5081706d587SHerbert Xu /* Make the one we just received the head. */ 5091706d587SHerbert Xu if (prev) { 5101706d587SHerbert Xu head = prev->next; 5111706d587SHerbert Xu fp = skb_clone(head, GFP_ATOMIC); 5121706d587SHerbert Xu if (!fp) 5131706d587SHerbert Xu goto out_nomem; 5141706d587SHerbert Xu 5151706d587SHerbert Xu fp->next = head->next; 516d6bebca9SChangli Gao if (!fp->next) 517d6bebca9SChangli Gao qp->q.fragments_tail = fp; 5181706d587SHerbert Xu prev->next = fp; 5191706d587SHerbert Xu 5205ab11c98SPavel Emelyanov skb_morph(head, qp->q.fragments); 5215ab11c98SPavel Emelyanov head->next = qp->q.fragments->next; 5221706d587SHerbert Xu 5235ab11c98SPavel Emelyanov kfree_skb(qp->q.fragments); 5245ab11c98SPavel Emelyanov qp->q.fragments = head; 5251706d587SHerbert Xu } 5261706d587SHerbert Xu 527547b792cSIlpo Järvinen WARN_ON(head == NULL); 528547b792cSIlpo Järvinen WARN_ON(FRAG_CB(head)->offset != 0); 5291da177e4SLinus Torvalds 5301da177e4SLinus Torvalds /* Allocate a new buffer for the datagram. */ 531c9bdd4b5SArnaldo Carvalho de Melo ihlen = ip_hdrlen(head); 5325ab11c98SPavel Emelyanov len = ihlen + qp->q.len; 5331da177e4SLinus Torvalds 5341706d587SHerbert Xu err = -E2BIG; 5351da177e4SLinus Torvalds if (len > 65535) 5361da177e4SLinus Torvalds goto out_oversize; 5371da177e4SLinus Torvalds 5381da177e4SLinus Torvalds /* Head of list must not be cloned. */ 5391da177e4SLinus Torvalds if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) 5401da177e4SLinus Torvalds goto out_nomem; 5411da177e4SLinus Torvalds 5421da177e4SLinus Torvalds /* If the first fragment is fragmented itself, we split 5431da177e4SLinus Torvalds * it to two chunks: the first with data and paged part 5441da177e4SLinus Torvalds * and the second, holding only fragments. */ 54521dc3301SDavid S. Miller if (skb_has_frag_list(head)) { 5461da177e4SLinus Torvalds struct sk_buff *clone; 5471da177e4SLinus Torvalds int i, plen = 0; 5481da177e4SLinus Torvalds 5491da177e4SLinus Torvalds if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 5501da177e4SLinus Torvalds goto out_nomem; 5511da177e4SLinus Torvalds clone->next = head->next; 5521da177e4SLinus Torvalds head->next = clone; 5531da177e4SLinus Torvalds skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 554d7fcf1a5SDavid S. Miller skb_frag_list_init(head); 5551da177e4SLinus Torvalds for (i=0; i<skb_shinfo(head)->nr_frags; i++) 5561da177e4SLinus Torvalds plen += skb_shinfo(head)->frags[i].size; 5571da177e4SLinus Torvalds clone->len = clone->data_len = head->data_len - plen; 5581da177e4SLinus Torvalds head->data_len -= clone->len; 5591da177e4SLinus Torvalds head->len -= clone->len; 5601da177e4SLinus Torvalds clone->csum = 0; 5611da177e4SLinus Torvalds clone->ip_summed = head->ip_summed; 5626ddc0822SPavel Emelyanov atomic_add(clone->truesize, &qp->q.net->mem); 5631da177e4SLinus Torvalds } 5641da177e4SLinus Torvalds 5651da177e4SLinus Torvalds skb_shinfo(head)->frag_list = head->next; 566d56f90a7SArnaldo Carvalho de Melo skb_push(head, head->data - skb_network_header(head)); 5671da177e4SLinus Torvalds 5681da177e4SLinus Torvalds for (fp=head->next; fp; fp = fp->next) { 5691da177e4SLinus Torvalds head->data_len += fp->len; 5701da177e4SLinus Torvalds head->len += fp->len; 5711da177e4SLinus Torvalds if (head->ip_summed != fp->ip_summed) 5721da177e4SLinus Torvalds head->ip_summed = CHECKSUM_NONE; 57384fa7933SPatrick McHardy else if (head->ip_summed == CHECKSUM_COMPLETE) 5741da177e4SLinus Torvalds head->csum = csum_add(head->csum, fp->csum); 5751da177e4SLinus Torvalds head->truesize += fp->truesize; 5761da177e4SLinus Torvalds } 577d27f9b35SEric Dumazet atomic_sub(head->truesize, &qp->q.net->mem); 5781da177e4SLinus Torvalds 5791da177e4SLinus Torvalds head->next = NULL; 5801da177e4SLinus Torvalds head->dev = dev; 5815ab11c98SPavel Emelyanov head->tstamp = qp->q.stamp; 5821da177e4SLinus Torvalds 583eddc9ec5SArnaldo Carvalho de Melo iph = ip_hdr(head); 5841da177e4SLinus Torvalds iph->frag_off = 0; 5851da177e4SLinus Torvalds iph->tot_len = htons(len); 5862bad35b7SJorge Boncompte [DTI2] IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS); 5875ab11c98SPavel Emelyanov qp->q.fragments = NULL; 588d6bebca9SChangli Gao qp->q.fragments_tail = NULL; 5891706d587SHerbert Xu return 0; 5901da177e4SLinus Torvalds 5911da177e4SLinus Torvalds out_nomem: 59264ce2073SPatrick McHardy LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing " 59364ce2073SPatrick McHardy "queue %p\n", qp); 59445542479SDavid Howells err = -ENOMEM; 5951da177e4SLinus Torvalds goto out_fail; 5961da177e4SLinus Torvalds out_oversize: 5971da177e4SLinus Torvalds if (net_ratelimit()) 598673d57e7SHarvey Harrison printk(KERN_INFO "Oversized IP packet from %pI4.\n", 599673d57e7SHarvey Harrison &qp->saddr); 6001da177e4SLinus Torvalds out_fail: 601bbf31bf1SDavid Ford IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 6021706d587SHerbert Xu return err; 6031da177e4SLinus Torvalds } 6041da177e4SLinus Torvalds 6051da177e4SLinus Torvalds /* Process an incoming IP datagram fragment. */ 606776c729eSHerbert Xu int ip_defrag(struct sk_buff *skb, u32 user) 6071da177e4SLinus Torvalds { 6081da177e4SLinus Torvalds struct ipq *qp; 609ac18e750SPavel Emelyanov struct net *net; 6101da177e4SLinus Torvalds 611adf30907SEric Dumazet net = skb->dev ? dev_net(skb->dev) : dev_net(skb_dst(skb)->dev); 6127c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS); 6131da177e4SLinus Torvalds 6141da177e4SLinus Torvalds /* Start by cleaning up the memory. */ 615e31e0bdcSPavel Emelyanov if (atomic_read(&net->ipv4.frags.mem) > net->ipv4.frags.high_thresh) 6166ddc0822SPavel Emelyanov ip_evictor(net); 6171da177e4SLinus Torvalds 6181da177e4SLinus Torvalds /* Lookup (or create) queue header */ 619ac18e750SPavel Emelyanov if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) { 6201706d587SHerbert Xu int ret; 6211da177e4SLinus Torvalds 6225ab11c98SPavel Emelyanov spin_lock(&qp->q.lock); 6231da177e4SLinus Torvalds 6241706d587SHerbert Xu ret = ip_frag_queue(qp, skb); 6251da177e4SLinus Torvalds 6265ab11c98SPavel Emelyanov spin_unlock(&qp->q.lock); 6274b6cb5d8SPavel Emelyanov ipq_put(qp); 628776c729eSHerbert Xu return ret; 6291da177e4SLinus Torvalds } 6301da177e4SLinus Torvalds 6317c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 6321da177e4SLinus Torvalds kfree_skb(skb); 633776c729eSHerbert Xu return -ENOMEM; 6341da177e4SLinus Torvalds } 6354bc2f18bSEric Dumazet EXPORT_SYMBOL(ip_defrag); 6361da177e4SLinus Torvalds 6378d8354d2SPavel Emelyanov #ifdef CONFIG_SYSCTL 6388d8354d2SPavel Emelyanov static int zero; 6398d8354d2SPavel Emelyanov 6400a64b4b8SPavel Emelyanov static struct ctl_table ip4_frags_ns_ctl_table[] = { 6418d8354d2SPavel Emelyanov { 6428d8354d2SPavel Emelyanov .procname = "ipfrag_high_thresh", 643e31e0bdcSPavel Emelyanov .data = &init_net.ipv4.frags.high_thresh, 6448d8354d2SPavel Emelyanov .maxlen = sizeof(int), 6458d8354d2SPavel Emelyanov .mode = 0644, 6466d9f239aSAlexey Dobriyan .proc_handler = proc_dointvec 6478d8354d2SPavel Emelyanov }, 6488d8354d2SPavel Emelyanov { 6498d8354d2SPavel Emelyanov .procname = "ipfrag_low_thresh", 650e31e0bdcSPavel Emelyanov .data = &init_net.ipv4.frags.low_thresh, 6518d8354d2SPavel Emelyanov .maxlen = sizeof(int), 6528d8354d2SPavel Emelyanov .mode = 0644, 6536d9f239aSAlexey Dobriyan .proc_handler = proc_dointvec 6548d8354d2SPavel Emelyanov }, 6558d8354d2SPavel Emelyanov { 6568d8354d2SPavel Emelyanov .procname = "ipfrag_time", 657b2fd5321SPavel Emelyanov .data = &init_net.ipv4.frags.timeout, 6588d8354d2SPavel Emelyanov .maxlen = sizeof(int), 6598d8354d2SPavel Emelyanov .mode = 0644, 6606d9f239aSAlexey Dobriyan .proc_handler = proc_dointvec_jiffies, 6618d8354d2SPavel Emelyanov }, 6627d291ebbSPavel Emelyanov { } 6637d291ebbSPavel Emelyanov }; 6647d291ebbSPavel Emelyanov 6657d291ebbSPavel Emelyanov static struct ctl_table ip4_frags_ctl_table[] = { 6668d8354d2SPavel Emelyanov { 6678d8354d2SPavel Emelyanov .procname = "ipfrag_secret_interval", 6683b4bc4a2SPavel Emelyanov .data = &ip4_frags.secret_interval, 6698d8354d2SPavel Emelyanov .maxlen = sizeof(int), 6708d8354d2SPavel Emelyanov .mode = 0644, 6716d9f239aSAlexey Dobriyan .proc_handler = proc_dointvec_jiffies, 6728d8354d2SPavel Emelyanov }, 6738d8354d2SPavel Emelyanov { 6748d8354d2SPavel Emelyanov .procname = "ipfrag_max_dist", 6758d8354d2SPavel Emelyanov .data = &sysctl_ipfrag_max_dist, 6768d8354d2SPavel Emelyanov .maxlen = sizeof(int), 6778d8354d2SPavel Emelyanov .mode = 0644, 6786d9f239aSAlexey Dobriyan .proc_handler = proc_dointvec_minmax, 6798d8354d2SPavel Emelyanov .extra1 = &zero 6808d8354d2SPavel Emelyanov }, 6818d8354d2SPavel Emelyanov { } 6828d8354d2SPavel Emelyanov }; 6838d8354d2SPavel Emelyanov 6842c8c1e72SAlexey Dobriyan static int __net_init ip4_frags_ns_ctl_register(struct net *net) 6858d8354d2SPavel Emelyanov { 686e4a2d5c2SPavel Emelyanov struct ctl_table *table; 6878d8354d2SPavel Emelyanov struct ctl_table_header *hdr; 6888d8354d2SPavel Emelyanov 6890a64b4b8SPavel Emelyanov table = ip4_frags_ns_ctl_table; 69009ad9bc7SOctavian Purdila if (!net_eq(net, &init_net)) { 6910a64b4b8SPavel Emelyanov table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL); 692e4a2d5c2SPavel Emelyanov if (table == NULL) 693e4a2d5c2SPavel Emelyanov goto err_alloc; 694e4a2d5c2SPavel Emelyanov 695e31e0bdcSPavel Emelyanov table[0].data = &net->ipv4.frags.high_thresh; 696e31e0bdcSPavel Emelyanov table[1].data = &net->ipv4.frags.low_thresh; 697b2fd5321SPavel Emelyanov table[2].data = &net->ipv4.frags.timeout; 698e4a2d5c2SPavel Emelyanov } 699e4a2d5c2SPavel Emelyanov 700e4a2d5c2SPavel Emelyanov hdr = register_net_sysctl_table(net, net_ipv4_ctl_path, table); 701e4a2d5c2SPavel Emelyanov if (hdr == NULL) 702e4a2d5c2SPavel Emelyanov goto err_reg; 703e4a2d5c2SPavel Emelyanov 704e4a2d5c2SPavel Emelyanov net->ipv4.frags_hdr = hdr; 705e4a2d5c2SPavel Emelyanov return 0; 706e4a2d5c2SPavel Emelyanov 707e4a2d5c2SPavel Emelyanov err_reg: 70809ad9bc7SOctavian Purdila if (!net_eq(net, &init_net)) 709e4a2d5c2SPavel Emelyanov kfree(table); 710e4a2d5c2SPavel Emelyanov err_alloc: 711e4a2d5c2SPavel Emelyanov return -ENOMEM; 712e4a2d5c2SPavel Emelyanov } 713e4a2d5c2SPavel Emelyanov 7142c8c1e72SAlexey Dobriyan static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net) 715e4a2d5c2SPavel Emelyanov { 716e4a2d5c2SPavel Emelyanov struct ctl_table *table; 717e4a2d5c2SPavel Emelyanov 718e4a2d5c2SPavel Emelyanov table = net->ipv4.frags_hdr->ctl_table_arg; 719e4a2d5c2SPavel Emelyanov unregister_net_sysctl_table(net->ipv4.frags_hdr); 720e4a2d5c2SPavel Emelyanov kfree(table); 7218d8354d2SPavel Emelyanov } 7227d291ebbSPavel Emelyanov 7237d291ebbSPavel Emelyanov static void ip4_frags_ctl_register(void) 7247d291ebbSPavel Emelyanov { 7257d291ebbSPavel Emelyanov register_net_sysctl_rotable(net_ipv4_ctl_path, ip4_frags_ctl_table); 7267d291ebbSPavel Emelyanov } 7278d8354d2SPavel Emelyanov #else 7280a64b4b8SPavel Emelyanov static inline int ip4_frags_ns_ctl_register(struct net *net) 7298d8354d2SPavel Emelyanov { 7308d8354d2SPavel Emelyanov return 0; 7318d8354d2SPavel Emelyanov } 732e4a2d5c2SPavel Emelyanov 7330a64b4b8SPavel Emelyanov static inline void ip4_frags_ns_ctl_unregister(struct net *net) 734e4a2d5c2SPavel Emelyanov { 735e4a2d5c2SPavel Emelyanov } 7367d291ebbSPavel Emelyanov 7377d291ebbSPavel Emelyanov static inline void ip4_frags_ctl_register(void) 7387d291ebbSPavel Emelyanov { 7397d291ebbSPavel Emelyanov } 7408d8354d2SPavel Emelyanov #endif 7418d8354d2SPavel Emelyanov 7422c8c1e72SAlexey Dobriyan static int __net_init ipv4_frags_init_net(struct net *net) 7438d8354d2SPavel Emelyanov { 744b2fd5321SPavel Emelyanov /* 745e31e0bdcSPavel Emelyanov * Fragment cache limits. We will commit 256K at one time. Should we 746e31e0bdcSPavel Emelyanov * cross that limit we will prune down to 192K. This should cope with 747e31e0bdcSPavel Emelyanov * even the most extreme cases without allowing an attacker to 748e31e0bdcSPavel Emelyanov * measurably harm machine performance. 749e31e0bdcSPavel Emelyanov */ 750e31e0bdcSPavel Emelyanov net->ipv4.frags.high_thresh = 256 * 1024; 751e31e0bdcSPavel Emelyanov net->ipv4.frags.low_thresh = 192 * 1024; 752e31e0bdcSPavel Emelyanov /* 753b2fd5321SPavel Emelyanov * Important NOTE! Fragment queue must be destroyed before MSL expires. 754b2fd5321SPavel Emelyanov * RFC791 is wrong proposing to prolongate timer each fragment arrival 755b2fd5321SPavel Emelyanov * by TTL. 756b2fd5321SPavel Emelyanov */ 757b2fd5321SPavel Emelyanov net->ipv4.frags.timeout = IP_FRAG_TIME; 758b2fd5321SPavel Emelyanov 759e5a2bb84SPavel Emelyanov inet_frags_init_net(&net->ipv4.frags); 760e5a2bb84SPavel Emelyanov 7610a64b4b8SPavel Emelyanov return ip4_frags_ns_ctl_register(net); 7628d8354d2SPavel Emelyanov } 7638d8354d2SPavel Emelyanov 7642c8c1e72SAlexey Dobriyan static void __net_exit ipv4_frags_exit_net(struct net *net) 76581566e83SPavel Emelyanov { 7660a64b4b8SPavel Emelyanov ip4_frags_ns_ctl_unregister(net); 76781566e83SPavel Emelyanov inet_frags_exit_net(&net->ipv4.frags, &ip4_frags); 76881566e83SPavel Emelyanov } 76981566e83SPavel Emelyanov 77081566e83SPavel Emelyanov static struct pernet_operations ip4_frags_ops = { 77181566e83SPavel Emelyanov .init = ipv4_frags_init_net, 77281566e83SPavel Emelyanov .exit = ipv4_frags_exit_net, 77381566e83SPavel Emelyanov }; 77481566e83SPavel Emelyanov 775b7aa0bf7SEric Dumazet void __init ipfrag_init(void) 7761da177e4SLinus Torvalds { 7777d291ebbSPavel Emelyanov ip4_frags_ctl_register(); 77881566e83SPavel Emelyanov register_pernet_subsys(&ip4_frags_ops); 779321a3a99SPavel Emelyanov ip4_frags.hashfn = ip4_hashfn; 780c6fda282SPavel Emelyanov ip4_frags.constructor = ip4_frag_init; 7811e4b8287SPavel Emelyanov ip4_frags.destructor = ip4_frag_free; 7821e4b8287SPavel Emelyanov ip4_frags.skb_free = NULL; 7831e4b8287SPavel Emelyanov ip4_frags.qsize = sizeof(struct ipq); 784abd6523dSPavel Emelyanov ip4_frags.match = ip4_frag_match; 785e521db9dSPavel Emelyanov ip4_frags.frag_expire = ip_expire; 7863b4bc4a2SPavel Emelyanov ip4_frags.secret_interval = 10 * 60 * HZ; 7877eb95156SPavel Emelyanov inet_frags_init(&ip4_frags); 7881da177e4SLinus Torvalds } 789