ip_fragment.c revision c5346fe396f5e22bbfb3ec037c43891c3c57d3e6
11da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 21da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * INET An implementation of the TCP/IP protocol suite for the LINUX 31da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * operating system. INET is implemented using the BSD Socket 41da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * interface as the means of communication with the user level. 51da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 61da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * The IP fragmentation functionality. 7e905a9edab7f4f14f9213b52234e4a346c690911YOSHIFUJI Hideaki * 81da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG> 91da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Alan Cox <Alan.Cox@linux.org> 101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Fixes: 121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Alan Cox : Split from ip.c , see ip_input.c for history. 131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * David S. Miller : Begin massive cleanup... 141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Andi Kleen : Add sysctls. 151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * xxxx : Overlapfrag bug. 161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Ultima : ip_expire() kernel panic. 171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Bill Hawes : Frag accounting and evictor fixes. 181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * John McDonald : 0 length frag bug. 191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Alexey Kuznetsov: SMP races, threading, cleanup. 201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Patrick McHardy : LRU queue of frag heads for evictor. 211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2389cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu#include <linux/compiler.h> 241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/module.h> 251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/types.h> 261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/mm.h> 271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/jiffies.h> 281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/skbuff.h> 291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/list.h> 301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/ip.h> 311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/icmp.h> 321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/netdevice.h> 331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/jhash.h> 341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/random.h> 351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <net/sock.h> 361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <net/ip.h> 371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <net/icmp.h> 381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <net/checksum.h> 3989cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu#include <net/inetpeer.h> 405ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov#include <net/inet_frag.h> 411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/tcp.h> 421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/udp.h> 431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/inet.h> 441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/netfilter_ipv4.h> 451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6 471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c 481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * as well. Or notify me, at least. --ANK 491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 518d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanovstatic int sysctl_ipfrag_max_dist __read_mostly = 64; 5289cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstruct ipfrag_skb_cb 541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct inet_skb_parm h; 561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int offset; 571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#define FRAG_CB(skb) ((struct ipfrag_skb_cb*)((skb)->cb)) 601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* Describe an entry in the "incomplete datagrams" queue. */ 621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstruct ipq { 635ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov struct inet_frag_queue q; 645ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov 651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds u32 user; 66182777700d912a69824245e9ee99148ac0aa57d7Al Viro __be32 saddr; 67182777700d912a69824245e9ee99148ac0aa57d7Al Viro __be32 daddr; 68182777700d912a69824245e9ee99148ac0aa57d7Al Viro __be16 id; 691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds u8 protocol; 7089cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu int iif; 7189cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu unsigned int rid; 7289cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu struct inet_peer *peer; 731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds}; 741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 757eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanovstatic struct inet_frags ip4_frags; 761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 77e5a2bb842cd9681d00d4ca963e63e4d3647e66f8Pavel Emelyanovint ip_frag_nqueues(struct net *net) 787eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanov{ 79e5a2bb842cd9681d00d4ca963e63e4d3647e66f8Pavel Emelyanov return net->ipv4.frags.nqueues; 807eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanov} 811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 826ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanovint ip_frag_mem(struct net *net) 837eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanov{ 846ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov return atomic_read(&net->ipv4.frags.mem); 857eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanov} 861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 871706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xustatic int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, 881706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu struct net_device *dev); 891706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu 90c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanovstruct ip4_create_arg { 91c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov struct iphdr *iph; 92c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov u32 user; 93c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov}; 94c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov 95182777700d912a69824245e9ee99148ac0aa57d7Al Virostatic unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot) 961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 97182777700d912a69824245e9ee99148ac0aa57d7Al Viro return jhash_3words((__force u32)id << 16 | prot, 98182777700d912a69824245e9ee99148ac0aa57d7Al Viro (__force u32)saddr, (__force u32)daddr, 997eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanov ip4_frags.rnd) & (INETFRAGS_HASHSZ - 1); 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 102321a3a99e4717b960e21c62fc6a140d21453df7fPavel Emelyanovstatic unsigned int ip4_hashfn(struct inet_frag_queue *q) 1031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 104321a3a99e4717b960e21c62fc6a140d21453df7fPavel Emelyanov struct ipq *ipq; 1051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 106321a3a99e4717b960e21c62fc6a140d21453df7fPavel Emelyanov ipq = container_of(q, struct ipq, q); 107321a3a99e4717b960e21c62fc6a140d21453df7fPavel Emelyanov return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol); 1081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 110abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanovstatic int ip4_frag_match(struct inet_frag_queue *q, void *a) 111abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov{ 112abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov struct ipq *qp; 113abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov struct ip4_create_arg *arg = a; 114abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov 115abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov qp = container_of(q, struct ipq, q); 116abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov return (qp->id == arg->iph->id && 117abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov qp->saddr == arg->iph->saddr && 118abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov qp->daddr == arg->iph->daddr && 119abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov qp->protocol == arg->iph->protocol && 120abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov qp->user == arg->user); 121abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov} 122abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov 1231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* Memory Tracking Functions. */ 1246ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanovstatic __inline__ void frag_kfree_skb(struct netns_frags *nf, 1256ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov struct sk_buff *skb, int *work) 1261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (work) 1281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds *work -= skb->truesize; 1296ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov atomic_sub(skb->truesize, &nf->mem); 1301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds kfree_skb(skb); 1311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 133c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanovstatic void ip4_frag_init(struct inet_frag_queue *q, void *a) 134c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov{ 135c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov struct ipq *qp = container_of(q, struct ipq, q); 136c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov struct ip4_create_arg *arg = a; 137c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov 138c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov qp->protocol = arg->iph->protocol; 139c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov qp->id = arg->iph->id; 140c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov qp->saddr = arg->iph->saddr; 141c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov qp->daddr = arg->iph->daddr; 142c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov qp->user = arg->user; 143c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov qp->peer = sysctl_ipfrag_max_dist ? 144c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov inet_getpeer(arg->iph->saddr, 1) : NULL; 145c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov} 146c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov 1471e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanovstatic __inline__ void ip4_frag_free(struct inet_frag_queue *q) 1481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1491e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanov struct ipq *qp; 1501e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanov 1511e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanov qp = container_of(q, struct ipq, q); 1521e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanov if (qp->peer) 1531e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanov inet_putpeer(qp->peer); 1541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1571da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* Destruction primitives. */ 1581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1594b6cb5d8e3f5707d7a2e55cf7b05f1ea8bfc7a6dPavel Emelyanovstatic __inline__ void ipq_put(struct ipq *ipq) 1601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 161762cc40801ad757a34527d5e548816cf3b6fc606Pavel Emelyanov inet_frag_put(&ipq->q, &ip4_frags); 1621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* Kill ipq entry. It is not destroyed immediately, 1651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * because caller (and someone more) holds reference count. 1661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void ipq_kill(struct ipq *ipq) 1681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 169277e650ddfc6944ef5f5466fd898b8da7f06cd82Pavel Emelyanov inet_frag_kill(&ipq->q, &ip4_frags); 1701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 172e905a9edab7f4f14f9213b52234e4a346c690911YOSHIFUJI Hideaki/* Memory limiting on fragments. Evictor trashes the oldest 1731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * fragment queue until we are back under the threshold. 1741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1756ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanovstatic void ip_evictor(struct net *net) 1761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1778e7999c44ee95e1e90ac91c83557a04e2948f160Pavel Emelyanov int evicted; 1788e7999c44ee95e1e90ac91c83557a04e2948f160Pavel Emelyanov 1796ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov evicted = inet_frag_evictor(&net->ipv4.frags, &ip4_frags); 1808e7999c44ee95e1e90ac91c83557a04e2948f160Pavel Emelyanov if (evicted) 181c5346fe396f5e22bbfb3ec037c43891c3c57d3e6Pavel Emelyanov IP_ADD_STATS_BH(net, IPSTATS_MIB_REASMFAILS, evicted); 1821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 1851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Oops, a fragment queue timed out. Kill it and send an ICMP reply. 1861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 1871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic void ip_expire(unsigned long arg) 1881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 189e521db9d790aaa60ae8920e21cb7faedc280fc36Pavel Emelyanov struct ipq *qp; 19084a3aa000eacbaf841d745b07ef3a3280899056bPavel Emelyanov struct net *net; 191e521db9d790aaa60ae8920e21cb7faedc280fc36Pavel Emelyanov 192e521db9d790aaa60ae8920e21cb7faedc280fc36Pavel Emelyanov qp = container_of((struct inet_frag_queue *) arg, struct ipq, q); 19384a3aa000eacbaf841d745b07ef3a3280899056bPavel Emelyanov net = container_of(qp->q.net, struct net, ipv4.frags); 1941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1955ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov spin_lock(&qp->q.lock); 1961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 197bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches if (qp->q.last_in & INET_FRAG_COMPLETE) 1981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto out; 1991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ipq_kill(qp); 2011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2027c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT); 2037c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 2041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 205bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches if ((qp->q.last_in & INET_FRAG_FIRST_IN) && qp->q.fragments != NULL) { 2065ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov struct sk_buff *head = qp->q.fragments; 207cb84663e4d239f23f0d872bc6463c272e74daad8Denis V. Lunev 2081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Send an ICMP "Fragment Reassembly Timeout" message. */ 209cb84663e4d239f23f0d872bc6463c272e74daad8Denis V. Lunev if ((head->dev = dev_get_by_index(net, qp->iif)) != NULL) { 2101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0); 2111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds dev_put(head->dev); 2121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 2141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsout: 2155ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov spin_unlock(&qp->q.lock); 2164b6cb5d8e3f5707d7a2e55cf7b05f1ea8bfc7a6dPavel Emelyanov ipq_put(qp); 2171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 219abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov/* Find the correct entry in the "incomplete datagrams" queue for 220abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov * this IP datagram, and create new one, if nothing is found. 221abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov */ 222ac18e7509e7df327e30d6e073a787d922eaf211dPavel Emelyanovstatic inline struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user) 2231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 224c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov struct inet_frag_queue *q; 225c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov struct ip4_create_arg arg; 226abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov unsigned int hash; 2271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 228c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov arg.iph = iph; 229c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov arg.user = user; 2309a375803feaadb6c34e0807bd9325885dcca5c00Pavel Emelyanov 2319a375803feaadb6c34e0807bd9325885dcca5c00Pavel Emelyanov read_lock(&ip4_frags.lock); 232abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol); 2331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 234ac18e7509e7df327e30d6e073a787d922eaf211dPavel Emelyanov q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash); 235c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov if (q == NULL) 236c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov goto out_nomem; 2371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 238c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov return container_of(q, struct ipq, q); 2391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 2401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsout_nomem: 24164ce207306debd7157f47282be94770407bec01cPatrick McHardy LIMIT_NETDEBUG(KERN_ERR "ip_frag_create: no memory left !\n"); 2421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return NULL; 2431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 2441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 24589cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu/* Is the fragment too far ahead to be part of ipq? */ 24689cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xustatic inline int ip_frag_too_far(struct ipq *qp) 24789cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu{ 24889cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu struct inet_peer *peer = qp->peer; 24989cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu unsigned int max = sysctl_ipfrag_max_dist; 25089cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu unsigned int start, end; 25189cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 25289cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu int rc; 25389cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 25489cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu if (!peer || !max) 25589cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu return 0; 25689cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 25789cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu start = qp->rid; 25889cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu end = atomic_inc_return(&peer->rid); 25989cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu qp->rid = end; 26089cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 2615ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov rc = qp->q.fragments && (end - start) > max; 26289cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 26389cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu if (rc) { 2647c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov struct net *net; 2657c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov 2667c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov net = container_of(qp->q.net, struct net, ipv4.frags); 2677c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 26889cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu } 26989cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 27089cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu return rc; 27189cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu} 27289cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 27389cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xustatic int ip_frag_reinit(struct ipq *qp) 27489cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu{ 27589cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu struct sk_buff *fp; 27689cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 277b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) { 2785ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov atomic_inc(&qp->q.refcnt); 27989cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu return -ETIMEDOUT; 28089cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu } 28189cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 2825ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov fp = qp->q.fragments; 28389cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu do { 28489cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu struct sk_buff *xp = fp->next; 2856ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov frag_kfree_skb(qp->q.net, fp, NULL); 28689cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu fp = xp; 28789cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu } while (fp); 28889cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 2895ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.last_in = 0; 2905ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.len = 0; 2915ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.meat = 0; 2925ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.fragments = NULL; 29389cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu qp->iif = 0; 29489cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 29589cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu return 0; 29689cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu} 29789cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 2981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* Add new segment to existing queue. */ 2991706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xustatic int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) 3001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 3011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct sk_buff *prev, *next; 3021706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu struct net_device *dev; 3031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int flags, offset; 3041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int ihl, end; 3051706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu int err = -ENOENT; 3061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 307bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches if (qp->q.last_in & INET_FRAG_COMPLETE) 3081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 3091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 31089cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) && 3111706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu unlikely(ip_frag_too_far(qp)) && 3121706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu unlikely(err = ip_frag_reinit(qp))) { 31389cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu ipq_kill(qp); 31489cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu goto err; 31589cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu } 31689cee8b1cbb9dac40c92ef1968aea2b45f82fd18Herbert Xu 317eddc9ec53be2ecdbf4efe0efd4a83052594f0ac0Arnaldo Carvalho de Melo offset = ntohs(ip_hdr(skb)->frag_off); 3181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds flags = offset & ~IP_OFFSET; 3191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds offset &= IP_OFFSET; 3201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds offset <<= 3; /* offset is in 8-byte chunks */ 321c9bdd4b5257406b0608385d19c40b5511decf4f6Arnaldo Carvalho de Melo ihl = ip_hdrlen(skb); 3221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Determine the position of this fragment. */ 324e905a9edab7f4f14f9213b52234e4a346c690911YOSHIFUJI Hideaki end = offset + skb->len - ihl; 3251706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu err = -EINVAL; 3261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Is this the final fragment? */ 3281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if ((flags & IP_MF) == 0) { 3291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* If we already have some bits beyond end 3301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * or have different end, the segment is corrrupted. 3311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3325ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov if (end < qp->q.len || 333bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches ((qp->q.last_in & INET_FRAG_LAST_IN) && end != qp->q.len)) 3341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 335bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches qp->q.last_in |= INET_FRAG_LAST_IN; 3365ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.len = end; 3371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } else { 3381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (end&7) { 3391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds end &= ~7; 3401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (skb->ip_summed != CHECKSUM_UNNECESSARY) 3411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 3421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3435ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov if (end > qp->q.len) { 3441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Some bits beyond end -> corruption. */ 345bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches if (qp->q.last_in & INET_FRAG_LAST_IN) 3461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 3475ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.len = end; 3481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (end == offset) 3511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 3521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3531706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu err = -ENOMEM; 3541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (pskb_pull(skb, ihl) == NULL) 3551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 3561706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu 3571706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu err = pskb_trim_rcsum(skb, end - offset); 3581706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu if (err) 3591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 3601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Find out which fragments are in front and at the back of us 3621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * in the chain of fragments so far. We must know where to put 3631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * this fragment, right? 3641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds prev = NULL; 3665ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov for (next = qp->q.fragments; next != NULL; next = next->next) { 3671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (FRAG_CB(next)->offset >= offset) 3681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds break; /* bingo! */ 3691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds prev = next; 3701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* We found where to put this one. Check for overlap with 3731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * preceding fragment, and, if needed, align things so that 3741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * any overlaps are eliminated. 3751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 3761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (prev) { 3771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int i = (FRAG_CB(prev)->offset + prev->len) - offset; 3781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (i > 0) { 3801da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds offset += i; 3811706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu err = -EINVAL; 3821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (end <= offset) 3831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 3841706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu err = -ENOMEM; 3851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!pskb_pull(skb, i)) 3861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 3871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (skb->ip_summed != CHECKSUM_UNNECESSARY) 3881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 3891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 3911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3921706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu err = -ENOMEM; 3931706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu 3941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds while (next && FRAG_CB(next)->offset < end) { 3951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */ 3961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 3971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (i < next->len) { 3981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Eat head of the next overlapped fragment 3991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * and leave the loop. The next ones cannot overlap. 4001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 4011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!pskb_pull(next, i)) 4021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto err; 4031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds FRAG_CB(next)->offset += i; 4045ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.meat -= i; 4051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (next->ip_summed != CHECKSUM_UNNECESSARY) 4061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds next->ip_summed = CHECKSUM_NONE; 4071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds break; 4081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } else { 4091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct sk_buff *free_it = next; 4101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 41147c6bf7760bb8021bf7782f05bcd3b9f73ed2c2ePeter Zijlstra /* Old fragment is completely overridden with 4121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * new one drop it. 4131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 4141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds next = next->next; 4151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (prev) 4171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds prev->next = next; 4181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds else 4195ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.fragments = next; 4201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4215ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.meat -= free_it->len; 4226ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov frag_kfree_skb(qp->q.net, free_it, NULL); 4231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 4241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 4251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds FRAG_CB(skb)->offset = offset; 4271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Insert this fragment in the chain of fragments. */ 4291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds skb->next = next; 4301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (prev) 4311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds prev->next = skb; 4321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds else 4335ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.fragments = skb; 4341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4351706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu dev = skb->dev; 4361706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu if (dev) { 4371706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu qp->iif = dev->ifindex; 4381706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu skb->dev = NULL; 4391706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu } 4405ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.stamp = skb->tstamp; 4415ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.meat += skb->len; 4426ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov atomic_add(skb->truesize, &qp->q.net->mem); 4431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (offset == 0) 444bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches qp->q.last_in |= INET_FRAG_FIRST_IN; 4451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 446bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches if (qp->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 447bc578a54f0fd489d0722303f9a52508495ccaf9aJoe Perches qp->q.meat == qp->q.len) 4481706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu return ip_frag_reasm(qp, prev, dev); 4491706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu 4507eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanov write_lock(&ip4_frags.lock); 4513140c25c82106645a6b1fc469dab7006a1d09fd0Pavel Emelyanov list_move_tail(&qp->q.lru_list, &qp->q.net->lru_list); 4527eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanov write_unlock(&ip4_frags.lock); 4531706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu return -EINPROGRESS; 4541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldserr: 4561da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds kfree_skb(skb); 4571706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu return err; 4581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 4591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* Build a new IP datagram from all its fragments. */ 4621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4631706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xustatic int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, 4641706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu struct net_device *dev) 4651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 4661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct iphdr *iph; 4675ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov struct sk_buff *fp, *head = qp->q.fragments; 4681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int len; 4691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int ihlen; 4701706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu int err; 4711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ipq_kill(qp); 4731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4741706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu /* Make the one we just received the head. */ 4751706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu if (prev) { 4761706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu head = prev->next; 4771706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu fp = skb_clone(head, GFP_ATOMIC); 4781706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu if (!fp) 4791706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu goto out_nomem; 4801706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu 4811706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu fp->next = head->next; 4821706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu prev->next = fp; 4831706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu 4845ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov skb_morph(head, qp->q.fragments); 4855ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov head->next = qp->q.fragments->next; 4861706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu 4875ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov kfree_skb(qp->q.fragments); 4885ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.fragments = head; 4891706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu } 4901706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu 4911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds BUG_TRAP(head != NULL); 4921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds BUG_TRAP(FRAG_CB(head)->offset == 0); 4931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Allocate a new buffer for the datagram. */ 495c9bdd4b5257406b0608385d19c40b5511decf4f6Arnaldo Carvalho de Melo ihlen = ip_hdrlen(head); 4965ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov len = ihlen + qp->q.len; 4971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 4981706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu err = -E2BIG; 499132adf54639cf7dd9315e8df89c2faa59f6e46d9Stephen Hemminger if (len > 65535) 5001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto out_oversize; 5011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Head of list must not be cloned. */ 5031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) 5041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto out_nomem; 5051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* If the first fragment is fragmented itself, we split 5071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * it to two chunks: the first with data and paged part 5081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * and the second, holding only fragments. */ 5091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (skb_shinfo(head)->frag_list) { 5101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct sk_buff *clone; 5111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int i, plen = 0; 5121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 5141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto out_nomem; 5151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds clone->next = head->next; 5161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->next = clone; 5171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 5181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds skb_shinfo(head)->frag_list = NULL; 5191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds for (i=0; i<skb_shinfo(head)->nr_frags; i++) 5201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds plen += skb_shinfo(head)->frags[i].size; 5211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds clone->len = clone->data_len = head->data_len - plen; 5221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->data_len -= clone->len; 5231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->len -= clone->len; 5241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds clone->csum = 0; 5251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds clone->ip_summed = head->ip_summed; 5266ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov atomic_add(clone->truesize, &qp->q.net->mem); 5271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 5281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds skb_shinfo(head)->frag_list = head->next; 530d56f90a7c96da5187f0cdf07ee7434fe6aa78bbcArnaldo Carvalho de Melo skb_push(head, head->data - skb_network_header(head)); 5316ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov atomic_sub(head->truesize, &qp->q.net->mem); 5321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds for (fp=head->next; fp; fp = fp->next) { 5341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->data_len += fp->len; 5351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->len += fp->len; 5361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (head->ip_summed != fp->ip_summed) 5371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->ip_summed = CHECKSUM_NONE; 53884fa7933a33f806bbbaae6775e87459b1ec584c0Patrick McHardy else if (head->ip_summed == CHECKSUM_COMPLETE) 5391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->csum = csum_add(head->csum, fp->csum); 5401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->truesize += fp->truesize; 5416ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov atomic_sub(fp->truesize, &qp->q.net->mem); 5421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 5431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->next = NULL; 5451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds head->dev = dev; 5465ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov head->tstamp = qp->q.stamp; 5471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 548eddc9ec53be2ecdbf4efe0efd4a83052594f0ac0Arnaldo Carvalho de Melo iph = ip_hdr(head); 5491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds iph->frag_off = 0; 5501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds iph->tot_len = htons(len); 5517c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_REASMOKS); 5525ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov qp->q.fragments = NULL; 5531706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu return 0; 5541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsout_nomem: 556e905a9edab7f4f14f9213b52234e4a346c690911YOSHIFUJI Hideaki LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing " 55764ce207306debd7157f47282be94770407bec01cPatrick McHardy "queue %p\n", qp); 55845542479fb261342d5244869cf3ca4636b7ffd43David Howells err = -ENOMEM; 5591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds goto out_fail; 5601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsout_oversize: 5611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (net_ratelimit()) 5621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO 563a7d632b6b4ad1c92746ed409e41f9dc571ec04e2YOSHIFUJI Hideaki "Oversized IP packet from " NIPQUAD_FMT ".\n", 5641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds NIPQUAD(qp->saddr)); 5651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsout_fail: 5667c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_REASMFAILS); 5671706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu return err; 5681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 5691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* Process an incoming IP datagram fragment. */ 571776c729e8d91b2740583a2169678f2d3f383458bHerbert Xuint ip_defrag(struct sk_buff *skb, u32 user) 5721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 5731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct ipq *qp; 574ac18e7509e7df327e30d6e073a787d922eaf211dPavel Emelyanov struct net *net; 575e905a9edab7f4f14f9213b52234e4a346c690911YOSHIFUJI Hideaki 57684a3aa000eacbaf841d745b07ef3a3280899056bPavel Emelyanov net = skb->dev ? dev_net(skb->dev) : dev_net(skb->dst->dev); 5777c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS); 5781da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5791da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Start by cleaning up the memory. */ 580e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov if (atomic_read(&net->ipv4.frags.mem) > net->ipv4.frags.high_thresh) 5816ddc082223ef0f73717b4133fa7e648842bbfd02Pavel Emelyanov ip_evictor(net); 5821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds /* Lookup (or create) queue header */ 584ac18e7509e7df327e30d6e073a787d922eaf211dPavel Emelyanov if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) { 5851706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu int ret; 5861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5875ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov spin_lock(&qp->q.lock); 5881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5891706d58763c36133d7fce6cc78b1444fd40db28cHerbert Xu ret = ip_frag_queue(qp, skb); 5901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5915ab11c98d3a950faf6922b6166e5f8fc874590e7Pavel Emelyanov spin_unlock(&qp->q.lock); 5924b6cb5d8e3f5707d7a2e55cf7b05f1ea8bfc7a6dPavel Emelyanov ipq_put(qp); 593776c729e8d91b2740583a2169678f2d3f383458bHerbert Xu return ret; 5941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 5951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 5967c73a6faffae0bfae70639113aecf06af666e714Pavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 5971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds kfree_skb(skb); 598776c729e8d91b2740583a2169678f2d3f383458bHerbert Xu return -ENOMEM; 5991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 6001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 6018d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov#ifdef CONFIG_SYSCTL 6028d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanovstatic int zero; 6038d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov 6040a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanovstatic struct ctl_table ip4_frags_ns_ctl_table[] = { 6058d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov { 6068d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .ctl_name = NET_IPV4_IPFRAG_HIGH_THRESH, 6078d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .procname = "ipfrag_high_thresh", 608e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov .data = &init_net.ipv4.frags.high_thresh, 6098d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .maxlen = sizeof(int), 6108d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .mode = 0644, 6118d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .proc_handler = &proc_dointvec 6128d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov }, 6138d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov { 6148d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .ctl_name = NET_IPV4_IPFRAG_LOW_THRESH, 6158d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .procname = "ipfrag_low_thresh", 616e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov .data = &init_net.ipv4.frags.low_thresh, 6178d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .maxlen = sizeof(int), 6188d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .mode = 0644, 6198d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .proc_handler = &proc_dointvec 6208d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov }, 6218d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov { 6228d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .ctl_name = NET_IPV4_IPFRAG_TIME, 6238d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .procname = "ipfrag_time", 624b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov .data = &init_net.ipv4.frags.timeout, 6258d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .maxlen = sizeof(int), 6268d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .mode = 0644, 6278d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .proc_handler = &proc_dointvec_jiffies, 6288d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .strategy = &sysctl_jiffies 6298d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov }, 6307d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov { } 6317d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov}; 6327d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov 6337d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanovstatic struct ctl_table ip4_frags_ctl_table[] = { 6348d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov { 6358d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .ctl_name = NET_IPV4_IPFRAG_SECRET_INTERVAL, 6368d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .procname = "ipfrag_secret_interval", 6373b4bc4a2bfe80d01ebd4f2b6dcc58986c970ed16Pavel Emelyanov .data = &ip4_frags.secret_interval, 6388d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .maxlen = sizeof(int), 6398d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .mode = 0644, 6408d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .proc_handler = &proc_dointvec_jiffies, 6418d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .strategy = &sysctl_jiffies 6428d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov }, 6438d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov { 6448d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .procname = "ipfrag_max_dist", 6458d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .data = &sysctl_ipfrag_max_dist, 6468d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .maxlen = sizeof(int), 6478d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .mode = 0644, 6488d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .proc_handler = &proc_dointvec_minmax, 6498d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov .extra1 = &zero 6508d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov }, 6518d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov { } 6528d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov}; 6538d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov 6540a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanovstatic int ip4_frags_ns_ctl_register(struct net *net) 6558d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov{ 656e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov struct ctl_table *table; 6578d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov struct ctl_table_header *hdr; 6588d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov 6590a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanov table = ip4_frags_ns_ctl_table; 660e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov if (net != &init_net) { 6610a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanov table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL); 662e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov if (table == NULL) 663e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov goto err_alloc; 664e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov 665e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov table[0].data = &net->ipv4.frags.high_thresh; 666e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov table[1].data = &net->ipv4.frags.low_thresh; 667b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov table[2].data = &net->ipv4.frags.timeout; 668e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov } 669e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov 670e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov hdr = register_net_sysctl_table(net, net_ipv4_ctl_path, table); 671e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov if (hdr == NULL) 672e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov goto err_reg; 673e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov 674e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov net->ipv4.frags_hdr = hdr; 675e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov return 0; 676e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov 677e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanoverr_reg: 678e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov if (net != &init_net) 679e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov kfree(table); 680e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanoverr_alloc: 681e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov return -ENOMEM; 682e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov} 683e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov 6840a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanovstatic void ip4_frags_ns_ctl_unregister(struct net *net) 685e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov{ 686e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov struct ctl_table *table; 687e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov 688e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov table = net->ipv4.frags_hdr->ctl_table_arg; 689e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov unregister_net_sysctl_table(net->ipv4.frags_hdr); 690e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov kfree(table); 6918d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov} 6927d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov 6937d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanovstatic void ip4_frags_ctl_register(void) 6947d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov{ 6957d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov register_net_sysctl_rotable(net_ipv4_ctl_path, ip4_frags_ctl_table); 6967d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov} 6978d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov#else 6980a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanovstatic inline int ip4_frags_ns_ctl_register(struct net *net) 6998d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov{ 7008d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov return 0; 7018d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov} 702e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov 7030a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanovstatic inline void ip4_frags_ns_ctl_unregister(struct net *net) 704e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov{ 705e4a2d5c2bccd5bd29de5ae4f14ff4448fac9cfc8Pavel Emelyanov} 7067d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov 7077d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanovstatic inline void ip4_frags_ctl_register(void) 7087d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov{ 7097d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov} 7108d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov#endif 7118d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov 7128d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanovstatic int ipv4_frags_init_net(struct net *net) 7138d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov{ 714b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov /* 715e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov * Fragment cache limits. We will commit 256K at one time. Should we 716e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov * cross that limit we will prune down to 192K. This should cope with 717e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov * even the most extreme cases without allowing an attacker to 718e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov * measurably harm machine performance. 719e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov */ 720e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov net->ipv4.frags.high_thresh = 256 * 1024; 721e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov net->ipv4.frags.low_thresh = 192 * 1024; 722e31e0bdc7e7fb9a4b09d2f3266c035a18fdcee9dPavel Emelyanov /* 723b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov * Important NOTE! Fragment queue must be destroyed before MSL expires. 724b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov * RFC791 is wrong proposing to prolongate timer each fragment arrival 725b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov * by TTL. 726b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov */ 727b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov net->ipv4.frags.timeout = IP_FRAG_TIME; 728b2fd5321dd160ef309dfb6cfc78ed8de4a830659Pavel Emelyanov 729e5a2bb842cd9681d00d4ca963e63e4d3647e66f8Pavel Emelyanov inet_frags_init_net(&net->ipv4.frags); 730e5a2bb842cd9681d00d4ca963e63e4d3647e66f8Pavel Emelyanov 7310a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanov return ip4_frags_ns_ctl_register(net); 7328d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov} 7338d8354d2fb9277f165715a6e1cb92bcc89259975Pavel Emelyanov 73481566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanovstatic void ipv4_frags_exit_net(struct net *net) 73581566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov{ 7360a64b4b811025ce0386ad84d81504e4ff7985856Pavel Emelyanov ip4_frags_ns_ctl_unregister(net); 73781566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov inet_frags_exit_net(&net->ipv4.frags, &ip4_frags); 73881566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov} 73981566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov 74081566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanovstatic struct pernet_operations ip4_frags_ops = { 74181566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov .init = ipv4_frags_init_net, 74281566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov .exit = ipv4_frags_exit_net, 74381566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov}; 74481566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov 745b7aa0bf70c4afb9e38be25f5c0922498d0f8684cEric Dumazetvoid __init ipfrag_init(void) 7461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 7477d291ebb834278e30c211b26fb7076adcb636ad9Pavel Emelyanov ip4_frags_ctl_register(); 74881566e8322c3f6c6f9a2277fe0e440fee8d917bdPavel Emelyanov register_pernet_subsys(&ip4_frags_ops); 749321a3a99e4717b960e21c62fc6a140d21453df7fPavel Emelyanov ip4_frags.hashfn = ip4_hashfn; 750c6fda282294da882f8d8cc4c513940277dd380f5Pavel Emelyanov ip4_frags.constructor = ip4_frag_init; 7511e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanov ip4_frags.destructor = ip4_frag_free; 7521e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanov ip4_frags.skb_free = NULL; 7531e4b82873af0f21002e37a81ef063d2e5410deb3Pavel Emelyanov ip4_frags.qsize = sizeof(struct ipq); 754abd6523d15f40bfee14652619a31a7f65f77f581Pavel Emelyanov ip4_frags.match = ip4_frag_match; 755e521db9d790aaa60ae8920e21cb7faedc280fc36Pavel Emelyanov ip4_frags.frag_expire = ip_expire; 7563b4bc4a2bfe80d01ebd4f2b6dcc58986c970ed16Pavel Emelyanov ip4_frags.secret_interval = 10 * 60 * HZ; 7577eb95156d9dce2f59794264db336ce007d71638bPavel Emelyanov inet_frags_init(&ip4_frags); 7581da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 7591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 7601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsEXPORT_SYMBOL(ip_defrag); 761