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 23afd46503SJoe Perches #define pr_fmt(fmt) "IPv4: " fmt 24afd46503SJoe Perches 2589cee8b1SHerbert Xu #include <linux/compiler.h> 261da177e4SLinus Torvalds #include <linux/module.h> 271da177e4SLinus Torvalds #include <linux/types.h> 281da177e4SLinus Torvalds #include <linux/mm.h> 291da177e4SLinus Torvalds #include <linux/jiffies.h> 301da177e4SLinus Torvalds #include <linux/skbuff.h> 311da177e4SLinus Torvalds #include <linux/list.h> 321da177e4SLinus Torvalds #include <linux/ip.h> 331da177e4SLinus Torvalds #include <linux/icmp.h> 341da177e4SLinus Torvalds #include <linux/netdevice.h> 351da177e4SLinus Torvalds #include <linux/jhash.h> 361da177e4SLinus Torvalds #include <linux/random.h> 375a0e3ad6STejun Heo #include <linux/slab.h> 38e9017b55SShan Wei #include <net/route.h> 39e9017b55SShan Wei #include <net/dst.h> 401da177e4SLinus Torvalds #include <net/sock.h> 411da177e4SLinus Torvalds #include <net/ip.h> 421da177e4SLinus Torvalds #include <net/icmp.h> 431da177e4SLinus Torvalds #include <net/checksum.h> 4489cee8b1SHerbert Xu #include <net/inetpeer.h> 455ab11c98SPavel Emelyanov #include <net/inet_frag.h> 461da177e4SLinus Torvalds #include <linux/tcp.h> 471da177e4SLinus Torvalds #include <linux/udp.h> 481da177e4SLinus Torvalds #include <linux/inet.h> 491da177e4SLinus Torvalds #include <linux/netfilter_ipv4.h> 506623e3b2SEric Dumazet #include <net/inet_ecn.h> 51385add90SDavid Ahern #include <net/l3mdev.h> 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds /* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6 541da177e4SLinus Torvalds * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c 551da177e4SLinus Torvalds * as well. Or notify me, at least. --ANK 561da177e4SLinus Torvalds */ 571da177e4SLinus Torvalds 588d8354d2SPavel Emelyanov static int sysctl_ipfrag_max_dist __read_mostly = 64; 59d4ad4d22SNikolay Aleksandrov static const char ip_frag_cache_name[] = "ip4-frags"; 6089cee8b1SHerbert Xu 611da177e4SLinus Torvalds struct ipfrag_skb_cb 621da177e4SLinus Torvalds { 631da177e4SLinus Torvalds struct inet_skb_parm h; 641da177e4SLinus Torvalds int offset; 651da177e4SLinus Torvalds }; 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds #define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb)) 681da177e4SLinus Torvalds 691da177e4SLinus Torvalds /* Describe an entry in the "incomplete datagrams" queue. */ 701da177e4SLinus Torvalds struct ipq { 715ab11c98SPavel Emelyanov struct inet_frag_queue q; 725ab11c98SPavel Emelyanov 731da177e4SLinus Torvalds u32 user; 7418277770SAl Viro __be32 saddr; 7518277770SAl Viro __be32 daddr; 7618277770SAl Viro __be16 id; 771da177e4SLinus Torvalds u8 protocol; 786623e3b2SEric Dumazet u8 ecn; /* RFC3168 support */ 79d6b915e2SFlorian Westphal u16 max_df_size; /* largest frag with DF set seen */ 8089cee8b1SHerbert Xu int iif; 81385add90SDavid Ahern int vif; /* L3 master device index */ 8289cee8b1SHerbert Xu unsigned int rid; 8389cee8b1SHerbert Xu struct inet_peer *peer; 841da177e4SLinus Torvalds }; 851da177e4SLinus Torvalds 86aa1f731eSFabian Frederick static u8 ip4_frag_ecn(u8 tos) 876623e3b2SEric Dumazet { 885173cc05SEric Dumazet return 1 << (tos & INET_ECN_MASK); 896623e3b2SEric Dumazet } 906623e3b2SEric Dumazet 917eb95156SPavel Emelyanov static struct inet_frags ip4_frags; 921da177e4SLinus Torvalds 936ddc0822SPavel Emelyanov int ip_frag_mem(struct net *net) 947eb95156SPavel Emelyanov { 95d433673eSJesper Dangaard Brouer return sum_frag_mem_limit(&net->ipv4.frags); 967eb95156SPavel Emelyanov } 971da177e4SLinus Torvalds 981706d587SHerbert Xu static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, 991706d587SHerbert Xu struct net_device *dev); 1001706d587SHerbert Xu 101c6fda282SPavel Emelyanov struct ip4_create_arg { 102c6fda282SPavel Emelyanov struct iphdr *iph; 103c6fda282SPavel Emelyanov u32 user; 1049972f134SDavid Ahern int vif; 105c6fda282SPavel Emelyanov }; 106c6fda282SPavel Emelyanov 10718277770SAl Viro static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot) 1081da177e4SLinus Torvalds { 109e7b519baSHannes Frederic Sowa net_get_random_once(&ip4_frags.rnd, sizeof(ip4_frags.rnd)); 11018277770SAl Viro return jhash_3words((__force u32)id << 16 | prot, 11118277770SAl Viro (__force u32)saddr, (__force u32)daddr, 112fb3cfe6eSFlorian Westphal ip4_frags.rnd); 1131da177e4SLinus Torvalds } 1141da177e4SLinus Torvalds 11536c77782SFlorian Westphal static unsigned int ip4_hashfn(const struct inet_frag_queue *q) 1161da177e4SLinus Torvalds { 11736c77782SFlorian Westphal const struct ipq *ipq; 1181da177e4SLinus Torvalds 119321a3a99SPavel Emelyanov ipq = container_of(q, struct ipq, q); 120321a3a99SPavel Emelyanov return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol); 1211da177e4SLinus Torvalds } 1221da177e4SLinus Torvalds 12336c77782SFlorian Westphal static bool ip4_frag_match(const struct inet_frag_queue *q, const void *a) 124abd6523dSPavel Emelyanov { 12536c77782SFlorian Westphal const struct ipq *qp; 12636c77782SFlorian Westphal const struct ip4_create_arg *arg = a; 127abd6523dSPavel Emelyanov 128abd6523dSPavel Emelyanov qp = container_of(q, struct ipq, q); 129a02cec21SEric Dumazet return qp->id == arg->iph->id && 130abd6523dSPavel Emelyanov qp->saddr == arg->iph->saddr && 131abd6523dSPavel Emelyanov qp->daddr == arg->iph->daddr && 132abd6523dSPavel Emelyanov qp->protocol == arg->iph->protocol && 1339972f134SDavid Ahern qp->user == arg->user && 1349972f134SDavid Ahern qp->vif == arg->vif; 135abd6523dSPavel Emelyanov } 136abd6523dSPavel Emelyanov 13736c77782SFlorian Westphal static void ip4_frag_init(struct inet_frag_queue *q, const void *a) 138c6fda282SPavel Emelyanov { 139c6fda282SPavel Emelyanov struct ipq *qp = container_of(q, struct ipq, q); 14054db0cc2SGao feng struct netns_ipv4 *ipv4 = container_of(q->net, struct netns_ipv4, 14154db0cc2SGao feng frags); 14254db0cc2SGao feng struct net *net = container_of(ipv4, struct net, ipv4); 14354db0cc2SGao feng 14436c77782SFlorian Westphal const struct ip4_create_arg *arg = a; 145c6fda282SPavel Emelyanov 146c6fda282SPavel Emelyanov qp->protocol = arg->iph->protocol; 147c6fda282SPavel Emelyanov qp->id = arg->iph->id; 1486623e3b2SEric Dumazet qp->ecn = ip4_frag_ecn(arg->iph->tos); 149c6fda282SPavel Emelyanov qp->saddr = arg->iph->saddr; 150c6fda282SPavel Emelyanov qp->daddr = arg->iph->daddr; 1519972f134SDavid Ahern qp->vif = arg->vif; 152c6fda282SPavel Emelyanov qp->user = arg->user; 153c6fda282SPavel Emelyanov qp->peer = sysctl_ipfrag_max_dist ? 154192132b9SDavid Ahern inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, arg->vif, 1) : 155192132b9SDavid Ahern NULL; 156c6fda282SPavel Emelyanov } 157c6fda282SPavel Emelyanov 158aa1f731eSFabian Frederick static void ip4_frag_free(struct inet_frag_queue *q) 1591da177e4SLinus Torvalds { 1601e4b8287SPavel Emelyanov struct ipq *qp; 1611e4b8287SPavel Emelyanov 1621e4b8287SPavel Emelyanov qp = container_of(q, struct ipq, q); 1631e4b8287SPavel Emelyanov if (qp->peer) 1641e4b8287SPavel Emelyanov inet_putpeer(qp->peer); 1651da177e4SLinus Torvalds } 1661da177e4SLinus Torvalds 1671da177e4SLinus Torvalds 1681da177e4SLinus Torvalds /* Destruction primitives. */ 1691da177e4SLinus Torvalds 170aa1f731eSFabian Frederick static void ipq_put(struct ipq *ipq) 1711da177e4SLinus Torvalds { 172762cc408SPavel Emelyanov inet_frag_put(&ipq->q, &ip4_frags); 1731da177e4SLinus Torvalds } 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds /* Kill ipq entry. It is not destroyed immediately, 1761da177e4SLinus Torvalds * because caller (and someone more) holds reference count. 1771da177e4SLinus Torvalds */ 1781da177e4SLinus Torvalds static void ipq_kill(struct ipq *ipq) 1791da177e4SLinus Torvalds { 180277e650dSPavel Emelyanov inet_frag_kill(&ipq->q, &ip4_frags); 1811da177e4SLinus Torvalds } 1821da177e4SLinus Torvalds 1835cf42280SAndy Zhou static bool frag_expire_skip_icmp(u32 user) 1845cf42280SAndy Zhou { 1855cf42280SAndy Zhou return user == IP_DEFRAG_AF_PACKET || 1865cf42280SAndy Zhou ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN, 1878bc04864SAndy Zhou __IP_DEFRAG_CONNTRACK_IN_END) || 1888bc04864SAndy Zhou ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN, 1898bc04864SAndy Zhou __IP_DEFRAG_CONNTRACK_BRIDGE_IN); 1905cf42280SAndy Zhou } 1915cf42280SAndy Zhou 1921da177e4SLinus Torvalds /* 1931da177e4SLinus Torvalds * Oops, a fragment queue timed out. Kill it and send an ICMP reply. 1941da177e4SLinus Torvalds */ 1951da177e4SLinus Torvalds static void ip_expire(unsigned long arg) 1961da177e4SLinus Torvalds { 197e521db9dSPavel Emelyanov struct ipq *qp; 19884a3aa00SPavel Emelyanov struct net *net; 199e521db9dSPavel Emelyanov 200e521db9dSPavel Emelyanov qp = container_of((struct inet_frag_queue *) arg, struct ipq, q); 20184a3aa00SPavel Emelyanov net = container_of(qp->q.net, struct net, ipv4.frags); 2021da177e4SLinus Torvalds 2035ab11c98SPavel Emelyanov spin_lock(&qp->q.lock); 2041da177e4SLinus Torvalds 20506aa8b8aSNikolay Aleksandrov if (qp->q.flags & INET_FRAG_COMPLETE) 2061da177e4SLinus Torvalds goto out; 2071da177e4SLinus Torvalds 2081da177e4SLinus Torvalds ipq_kill(qp); 2097c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 2101da177e4SLinus Torvalds 211caaecdd3SNikolay Aleksandrov if (!inet_frag_evicting(&qp->q)) { 2125ab11c98SPavel Emelyanov struct sk_buff *head = qp->q.fragments; 21364f3b9e2SEric Dumazet const struct iphdr *iph; 21464f3b9e2SEric Dumazet int err; 215cb84663eSDenis V. Lunev 2162e404f63SNikolay Aleksandrov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT); 2172e404f63SNikolay Aleksandrov 2182e404f63SNikolay Aleksandrov if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !qp->q.fragments) 2192e404f63SNikolay Aleksandrov goto out; 2202e404f63SNikolay Aleksandrov 22169df9d59SEric Dumazet rcu_read_lock(); 22269df9d59SEric Dumazet head->dev = dev_get_by_index_rcu(net, qp->iif); 223e9017b55SShan Wei if (!head->dev) 224e9017b55SShan Wei goto out_rcu_unlock; 225e9017b55SShan Wei 22697599dc7SEric Dumazet /* skb has no dst, perform route lookup again */ 22764f3b9e2SEric Dumazet iph = ip_hdr(head); 228c6cffba4SDavid S. Miller err = ip_route_input_noref(head, iph->daddr, iph->saddr, 229c10237e0SDavid S. Miller iph->tos, head->dev); 23064f3b9e2SEric Dumazet if (err) 231e9017b55SShan Wei goto out_rcu_unlock; 232e9017b55SShan Wei 2332e404f63SNikolay Aleksandrov /* Only an end host needs to send an ICMP 234e9017b55SShan Wei * "Fragment Reassembly Timeout" message, per RFC792. 235e9017b55SShan Wei */ 2365cf42280SAndy Zhou if (frag_expire_skip_icmp(qp->user) && 2375cf42280SAndy Zhou (skb_rtable(head)->rt_type != RTN_LOCAL)) 238e9017b55SShan Wei goto out_rcu_unlock; 239e9017b55SShan Wei 240e9017b55SShan Wei /* Send an ICMP "Fragment Reassembly Timeout" message. */ 241e9017b55SShan Wei icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0); 242e9017b55SShan Wei out_rcu_unlock: 243e9017b55SShan Wei rcu_read_unlock(); 244d1c9ae6dSPatrick McHardy } 2451da177e4SLinus Torvalds out: 2465ab11c98SPavel Emelyanov spin_unlock(&qp->q.lock); 2474b6cb5d8SPavel Emelyanov ipq_put(qp); 2481da177e4SLinus Torvalds } 2491da177e4SLinus Torvalds 250abd6523dSPavel Emelyanov /* Find the correct entry in the "incomplete datagrams" queue for 251abd6523dSPavel Emelyanov * this IP datagram, and create new one, if nothing is found. 252abd6523dSPavel Emelyanov */ 2539972f134SDavid Ahern static struct ipq *ip_find(struct net *net, struct iphdr *iph, 2549972f134SDavid Ahern u32 user, int vif) 2551da177e4SLinus Torvalds { 256c6fda282SPavel Emelyanov struct inet_frag_queue *q; 257c6fda282SPavel Emelyanov struct ip4_create_arg arg; 258abd6523dSPavel Emelyanov unsigned int hash; 2591da177e4SLinus Torvalds 260c6fda282SPavel Emelyanov arg.iph = iph; 261c6fda282SPavel Emelyanov arg.user = user; 2629972f134SDavid Ahern arg.vif = vif; 2639a375803SPavel Emelyanov 264abd6523dSPavel Emelyanov hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol); 265c6fda282SPavel Emelyanov 266ac18e750SPavel Emelyanov q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash); 2675a3da1feSHannes Frederic Sowa if (IS_ERR_OR_NULL(q)) { 2685a3da1feSHannes Frederic Sowa inet_frag_maybe_warn_overflow(q, pr_fmt()); 2691da177e4SLinus Torvalds return NULL; 2701da177e4SLinus Torvalds } 2715a3da1feSHannes Frederic Sowa return container_of(q, struct ipq, q); 2725a3da1feSHannes Frederic Sowa } 2731da177e4SLinus Torvalds 27489cee8b1SHerbert Xu /* Is the fragment too far ahead to be part of ipq? */ 275aa1f731eSFabian Frederick static int ip_frag_too_far(struct ipq *qp) 27689cee8b1SHerbert Xu { 27789cee8b1SHerbert Xu struct inet_peer *peer = qp->peer; 27889cee8b1SHerbert Xu unsigned int max = sysctl_ipfrag_max_dist; 27989cee8b1SHerbert Xu unsigned int start, end; 28089cee8b1SHerbert Xu 28189cee8b1SHerbert Xu int rc; 28289cee8b1SHerbert Xu 28389cee8b1SHerbert Xu if (!peer || !max) 28489cee8b1SHerbert Xu return 0; 28589cee8b1SHerbert Xu 28689cee8b1SHerbert Xu start = qp->rid; 28789cee8b1SHerbert Xu end = atomic_inc_return(&peer->rid); 28889cee8b1SHerbert Xu qp->rid = end; 28989cee8b1SHerbert Xu 2905ab11c98SPavel Emelyanov rc = qp->q.fragments && (end - start) > max; 29189cee8b1SHerbert Xu 29289cee8b1SHerbert Xu if (rc) { 2937c73a6faSPavel Emelyanov struct net *net; 2947c73a6faSPavel Emelyanov 2957c73a6faSPavel Emelyanov net = container_of(qp->q.net, struct net, ipv4.frags); 2967c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 29789cee8b1SHerbert Xu } 29889cee8b1SHerbert Xu 29989cee8b1SHerbert Xu return rc; 30089cee8b1SHerbert Xu } 30189cee8b1SHerbert Xu 30289cee8b1SHerbert Xu static int ip_frag_reinit(struct ipq *qp) 30389cee8b1SHerbert Xu { 30489cee8b1SHerbert Xu struct sk_buff *fp; 305d433673eSJesper Dangaard Brouer unsigned int sum_truesize = 0; 30689cee8b1SHerbert Xu 307b2fd5321SPavel Emelyanov if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) { 3085ab11c98SPavel Emelyanov atomic_inc(&qp->q.refcnt); 30989cee8b1SHerbert Xu return -ETIMEDOUT; 31089cee8b1SHerbert Xu } 31189cee8b1SHerbert Xu 3125ab11c98SPavel Emelyanov fp = qp->q.fragments; 31389cee8b1SHerbert Xu do { 31489cee8b1SHerbert Xu struct sk_buff *xp = fp->next; 315d433673eSJesper Dangaard Brouer 316d433673eSJesper Dangaard Brouer sum_truesize += fp->truesize; 317d433673eSJesper Dangaard Brouer kfree_skb(fp); 31889cee8b1SHerbert Xu fp = xp; 31989cee8b1SHerbert Xu } while (fp); 3200e60d245SFlorian Westphal sub_frag_mem_limit(qp->q.net, sum_truesize); 32189cee8b1SHerbert Xu 32206aa8b8aSNikolay Aleksandrov qp->q.flags = 0; 3235ab11c98SPavel Emelyanov qp->q.len = 0; 3245ab11c98SPavel Emelyanov qp->q.meat = 0; 3255ab11c98SPavel Emelyanov qp->q.fragments = NULL; 326d6bebca9SChangli Gao qp->q.fragments_tail = NULL; 32789cee8b1SHerbert Xu qp->iif = 0; 3286623e3b2SEric Dumazet qp->ecn = 0; 32989cee8b1SHerbert Xu 33089cee8b1SHerbert Xu return 0; 33189cee8b1SHerbert Xu } 33289cee8b1SHerbert Xu 3331da177e4SLinus Torvalds /* Add new segment to existing queue. */ 3341706d587SHerbert Xu static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) 3351da177e4SLinus Torvalds { 3361da177e4SLinus Torvalds struct sk_buff *prev, *next; 3371706d587SHerbert Xu struct net_device *dev; 338d6b915e2SFlorian Westphal unsigned int fragsize; 3391da177e4SLinus Torvalds int flags, offset; 3401da177e4SLinus Torvalds int ihl, end; 3411706d587SHerbert Xu int err = -ENOENT; 3426623e3b2SEric Dumazet u8 ecn; 3431da177e4SLinus Torvalds 34406aa8b8aSNikolay Aleksandrov if (qp->q.flags & INET_FRAG_COMPLETE) 3451da177e4SLinus Torvalds goto err; 3461da177e4SLinus Torvalds 34789cee8b1SHerbert Xu if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) && 3481706d587SHerbert Xu unlikely(ip_frag_too_far(qp)) && 3491706d587SHerbert Xu unlikely(err = ip_frag_reinit(qp))) { 35089cee8b1SHerbert Xu ipq_kill(qp); 35189cee8b1SHerbert Xu goto err; 35289cee8b1SHerbert Xu } 35389cee8b1SHerbert Xu 3546623e3b2SEric Dumazet ecn = ip4_frag_ecn(ip_hdr(skb)->tos); 355eddc9ec5SArnaldo Carvalho de Melo offset = ntohs(ip_hdr(skb)->frag_off); 3561da177e4SLinus Torvalds flags = offset & ~IP_OFFSET; 3571da177e4SLinus Torvalds offset &= IP_OFFSET; 3581da177e4SLinus Torvalds offset <<= 3; /* offset is in 8-byte chunks */ 359c9bdd4b5SArnaldo Carvalho de Melo ihl = ip_hdrlen(skb); 3601da177e4SLinus Torvalds 3611da177e4SLinus Torvalds /* Determine the position of this fragment. */ 3620848f642SEdward Hyunkoo Jee end = offset + skb->len - skb_network_offset(skb) - ihl; 3631706d587SHerbert Xu err = -EINVAL; 3641da177e4SLinus Torvalds 3651da177e4SLinus Torvalds /* Is this the final fragment? */ 3661da177e4SLinus Torvalds if ((flags & IP_MF) == 0) { 3671da177e4SLinus Torvalds /* If we already have some bits beyond end 36842b2aa86SJustin P. Mattock * or have different end, the segment is corrupted. 3691da177e4SLinus Torvalds */ 3705ab11c98SPavel Emelyanov if (end < qp->q.len || 37106aa8b8aSNikolay Aleksandrov ((qp->q.flags & INET_FRAG_LAST_IN) && end != qp->q.len)) 3721da177e4SLinus Torvalds goto err; 37306aa8b8aSNikolay Aleksandrov qp->q.flags |= INET_FRAG_LAST_IN; 3745ab11c98SPavel Emelyanov qp->q.len = end; 3751da177e4SLinus Torvalds } else { 3761da177e4SLinus Torvalds if (end&7) { 3771da177e4SLinus Torvalds end &= ~7; 3781da177e4SLinus Torvalds if (skb->ip_summed != CHECKSUM_UNNECESSARY) 3791da177e4SLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 3801da177e4SLinus Torvalds } 3815ab11c98SPavel Emelyanov if (end > qp->q.len) { 3821da177e4SLinus Torvalds /* Some bits beyond end -> corruption. */ 38306aa8b8aSNikolay Aleksandrov if (qp->q.flags & INET_FRAG_LAST_IN) 3841da177e4SLinus Torvalds goto err; 3855ab11c98SPavel Emelyanov qp->q.len = end; 3861da177e4SLinus Torvalds } 3871da177e4SLinus Torvalds } 3881da177e4SLinus Torvalds if (end == offset) 3891da177e4SLinus Torvalds goto err; 3901da177e4SLinus Torvalds 3911706d587SHerbert Xu err = -ENOMEM; 3920848f642SEdward Hyunkoo Jee if (!pskb_pull(skb, skb_network_offset(skb) + ihl)) 3931da177e4SLinus Torvalds goto err; 3941706d587SHerbert Xu 3951706d587SHerbert Xu err = pskb_trim_rcsum(skb, end - offset); 3961706d587SHerbert Xu if (err) 3971da177e4SLinus Torvalds goto err; 3981da177e4SLinus Torvalds 3991da177e4SLinus Torvalds /* Find out which fragments are in front and at the back of us 4001da177e4SLinus Torvalds * in the chain of fragments so far. We must know where to put 4011da177e4SLinus Torvalds * this fragment, right? 4021da177e4SLinus Torvalds */ 403d6bebca9SChangli Gao prev = qp->q.fragments_tail; 404d6bebca9SChangli Gao if (!prev || FRAG_CB(prev)->offset < offset) { 405d6bebca9SChangli Gao next = NULL; 406d6bebca9SChangli Gao goto found; 407d6bebca9SChangli Gao } 4081da177e4SLinus Torvalds prev = NULL; 4095ab11c98SPavel Emelyanov for (next = qp->q.fragments; next != NULL; next = next->next) { 4101da177e4SLinus Torvalds if (FRAG_CB(next)->offset >= offset) 4111da177e4SLinus Torvalds break; /* bingo! */ 4121da177e4SLinus Torvalds prev = next; 4131da177e4SLinus Torvalds } 4141da177e4SLinus Torvalds 415d6bebca9SChangli Gao found: 4161da177e4SLinus Torvalds /* We found where to put this one. Check for overlap with 4171da177e4SLinus Torvalds * preceding fragment, and, if needed, align things so that 4181da177e4SLinus Torvalds * any overlaps are eliminated. 4191da177e4SLinus Torvalds */ 4201da177e4SLinus Torvalds if (prev) { 4211da177e4SLinus Torvalds int i = (FRAG_CB(prev)->offset + prev->len) - offset; 4221da177e4SLinus Torvalds 4231da177e4SLinus Torvalds if (i > 0) { 4241da177e4SLinus Torvalds offset += i; 4251706d587SHerbert Xu err = -EINVAL; 4261da177e4SLinus Torvalds if (end <= offset) 4271da177e4SLinus Torvalds goto err; 4281706d587SHerbert Xu err = -ENOMEM; 4291da177e4SLinus Torvalds if (!pskb_pull(skb, i)) 4301da177e4SLinus Torvalds goto err; 4311da177e4SLinus Torvalds if (skb->ip_summed != CHECKSUM_UNNECESSARY) 4321da177e4SLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 4331da177e4SLinus Torvalds } 4341da177e4SLinus Torvalds } 4351da177e4SLinus Torvalds 4361706d587SHerbert Xu err = -ENOMEM; 4371706d587SHerbert Xu 4381da177e4SLinus Torvalds while (next && FRAG_CB(next)->offset < end) { 4391da177e4SLinus Torvalds int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */ 4401da177e4SLinus Torvalds 4411da177e4SLinus Torvalds if (i < next->len) { 4421da177e4SLinus Torvalds /* Eat head of the next overlapped fragment 4431da177e4SLinus Torvalds * and leave the loop. The next ones cannot overlap. 4441da177e4SLinus Torvalds */ 4451da177e4SLinus Torvalds if (!pskb_pull(next, i)) 4461da177e4SLinus Torvalds goto err; 4471da177e4SLinus Torvalds FRAG_CB(next)->offset += i; 4485ab11c98SPavel Emelyanov qp->q.meat -= i; 4491da177e4SLinus Torvalds if (next->ip_summed != CHECKSUM_UNNECESSARY) 4501da177e4SLinus Torvalds next->ip_summed = CHECKSUM_NONE; 4511da177e4SLinus Torvalds break; 4521da177e4SLinus Torvalds } else { 4531da177e4SLinus Torvalds struct sk_buff *free_it = next; 4541da177e4SLinus Torvalds 45547c6bf77SPeter Zijlstra /* Old fragment is completely overridden with 4561da177e4SLinus Torvalds * new one drop it. 4571da177e4SLinus Torvalds */ 4581da177e4SLinus Torvalds next = next->next; 4591da177e4SLinus Torvalds 4601da177e4SLinus Torvalds if (prev) 4611da177e4SLinus Torvalds prev->next = next; 4621da177e4SLinus Torvalds else 4635ab11c98SPavel Emelyanov qp->q.fragments = next; 4641da177e4SLinus Torvalds 4655ab11c98SPavel Emelyanov qp->q.meat -= free_it->len; 4660e60d245SFlorian Westphal sub_frag_mem_limit(qp->q.net, free_it->truesize); 467d433673eSJesper Dangaard Brouer kfree_skb(free_it); 4681da177e4SLinus Torvalds } 4691da177e4SLinus Torvalds } 4701da177e4SLinus Torvalds 4711da177e4SLinus Torvalds FRAG_CB(skb)->offset = offset; 4721da177e4SLinus Torvalds 4731da177e4SLinus Torvalds /* Insert this fragment in the chain of fragments. */ 4741da177e4SLinus Torvalds skb->next = next; 475d6bebca9SChangli Gao if (!next) 476d6bebca9SChangli Gao qp->q.fragments_tail = skb; 4771da177e4SLinus Torvalds if (prev) 4781da177e4SLinus Torvalds prev->next = skb; 4791da177e4SLinus Torvalds else 4805ab11c98SPavel Emelyanov qp->q.fragments = skb; 4811da177e4SLinus Torvalds 4821706d587SHerbert Xu dev = skb->dev; 4831706d587SHerbert Xu if (dev) { 4841706d587SHerbert Xu qp->iif = dev->ifindex; 4851da177e4SLinus Torvalds skb->dev = NULL; 4861706d587SHerbert Xu } 4875ab11c98SPavel Emelyanov qp->q.stamp = skb->tstamp; 4885ab11c98SPavel Emelyanov qp->q.meat += skb->len; 4896623e3b2SEric Dumazet qp->ecn |= ecn; 4900e60d245SFlorian Westphal add_frag_mem_limit(qp->q.net, skb->truesize); 4911da177e4SLinus Torvalds if (offset == 0) 49206aa8b8aSNikolay Aleksandrov qp->q.flags |= INET_FRAG_FIRST_IN; 4931da177e4SLinus Torvalds 494d6b915e2SFlorian Westphal fragsize = skb->len + ihl; 495d6b915e2SFlorian Westphal 496d6b915e2SFlorian Westphal if (fragsize > qp->q.max_size) 497d6b915e2SFlorian Westphal qp->q.max_size = fragsize; 498d6b915e2SFlorian Westphal 4995f2d04f1SPatrick McHardy if (ip_hdr(skb)->frag_off & htons(IP_DF) && 500d6b915e2SFlorian Westphal fragsize > qp->max_df_size) 501d6b915e2SFlorian Westphal qp->max_df_size = fragsize; 5025f2d04f1SPatrick McHardy 50306aa8b8aSNikolay Aleksandrov if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 50497599dc7SEric Dumazet qp->q.meat == qp->q.len) { 50597599dc7SEric Dumazet unsigned long orefdst = skb->_skb_refdst; 5061706d587SHerbert Xu 50797599dc7SEric Dumazet skb->_skb_refdst = 0UL; 50897599dc7SEric Dumazet err = ip_frag_reasm(qp, prev, dev); 50997599dc7SEric Dumazet skb->_skb_refdst = orefdst; 51097599dc7SEric Dumazet return err; 51197599dc7SEric Dumazet } 51297599dc7SEric Dumazet 51397599dc7SEric Dumazet skb_dst_drop(skb); 5141706d587SHerbert Xu return -EINPROGRESS; 5151da177e4SLinus Torvalds 5161da177e4SLinus Torvalds err: 5171da177e4SLinus Torvalds kfree_skb(skb); 5181706d587SHerbert Xu return err; 5191da177e4SLinus Torvalds } 5201da177e4SLinus Torvalds 5211da177e4SLinus Torvalds 5221da177e4SLinus Torvalds /* Build a new IP datagram from all its fragments. */ 5231da177e4SLinus Torvalds 5241706d587SHerbert Xu static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, 5251706d587SHerbert Xu struct net_device *dev) 5261da177e4SLinus Torvalds { 5272bad35b7SJorge Boncompte [DTI2] struct net *net = container_of(qp->q.net, struct net, ipv4.frags); 5281da177e4SLinus Torvalds struct iphdr *iph; 5295ab11c98SPavel Emelyanov struct sk_buff *fp, *head = qp->q.fragments; 5301da177e4SLinus Torvalds int len; 5311da177e4SLinus Torvalds int ihlen; 5321706d587SHerbert Xu int err; 5335173cc05SEric Dumazet u8 ecn; 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds ipq_kill(qp); 5361da177e4SLinus Torvalds 537be991971SHannes Frederic Sowa ecn = ip_frag_ecn_table[qp->ecn]; 5385173cc05SEric Dumazet if (unlikely(ecn == 0xff)) { 5395173cc05SEric Dumazet err = -EINVAL; 5405173cc05SEric Dumazet goto out_fail; 5415173cc05SEric Dumazet } 5421706d587SHerbert Xu /* Make the one we just received the head. */ 5431706d587SHerbert Xu if (prev) { 5441706d587SHerbert Xu head = prev->next; 5451706d587SHerbert Xu fp = skb_clone(head, GFP_ATOMIC); 5461706d587SHerbert Xu if (!fp) 5471706d587SHerbert Xu goto out_nomem; 5481706d587SHerbert Xu 5491706d587SHerbert Xu fp->next = head->next; 550d6bebca9SChangli Gao if (!fp->next) 551d6bebca9SChangli Gao qp->q.fragments_tail = fp; 5521706d587SHerbert Xu prev->next = fp; 5531706d587SHerbert Xu 5545ab11c98SPavel Emelyanov skb_morph(head, qp->q.fragments); 5555ab11c98SPavel Emelyanov head->next = qp->q.fragments->next; 5561706d587SHerbert Xu 557cbf8f7bbSEric Dumazet consume_skb(qp->q.fragments); 5585ab11c98SPavel Emelyanov qp->q.fragments = head; 5591706d587SHerbert Xu } 5601706d587SHerbert Xu 56151456b29SIan Morris WARN_ON(!head); 562547b792cSIlpo Järvinen WARN_ON(FRAG_CB(head)->offset != 0); 5631da177e4SLinus Torvalds 5641da177e4SLinus Torvalds /* Allocate a new buffer for the datagram. */ 565c9bdd4b5SArnaldo Carvalho de Melo ihlen = ip_hdrlen(head); 5665ab11c98SPavel Emelyanov len = ihlen + qp->q.len; 5671da177e4SLinus Torvalds 5681706d587SHerbert Xu err = -E2BIG; 5691da177e4SLinus Torvalds if (len > 65535) 5701da177e4SLinus Torvalds goto out_oversize; 5711da177e4SLinus Torvalds 5721da177e4SLinus Torvalds /* Head of list must not be cloned. */ 57314bbd6a5SPravin B Shelar if (skb_unclone(head, GFP_ATOMIC)) 5741da177e4SLinus Torvalds goto out_nomem; 5751da177e4SLinus Torvalds 5761da177e4SLinus Torvalds /* If the first fragment is fragmented itself, we split 5771da177e4SLinus Torvalds * it to two chunks: the first with data and paged part 5781da177e4SLinus Torvalds * and the second, holding only fragments. */ 57921dc3301SDavid S. Miller if (skb_has_frag_list(head)) { 5801da177e4SLinus Torvalds struct sk_buff *clone; 5811da177e4SLinus Torvalds int i, plen = 0; 5821da177e4SLinus Torvalds 58351456b29SIan Morris clone = alloc_skb(0, GFP_ATOMIC); 58451456b29SIan Morris if (!clone) 5851da177e4SLinus Torvalds goto out_nomem; 5861da177e4SLinus Torvalds clone->next = head->next; 5871da177e4SLinus Torvalds head->next = clone; 5881da177e4SLinus Torvalds skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 589d7fcf1a5SDavid S. Miller skb_frag_list_init(head); 5901da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(head)->nr_frags; i++) 5919e903e08SEric Dumazet plen += skb_frag_size(&skb_shinfo(head)->frags[i]); 5921da177e4SLinus Torvalds clone->len = clone->data_len = head->data_len - plen; 5931da177e4SLinus Torvalds head->data_len -= clone->len; 5941da177e4SLinus Torvalds head->len -= clone->len; 5951da177e4SLinus Torvalds clone->csum = 0; 5961da177e4SLinus Torvalds clone->ip_summed = head->ip_summed; 5970e60d245SFlorian Westphal add_frag_mem_limit(qp->q.net, clone->truesize); 5981da177e4SLinus Torvalds } 5991da177e4SLinus Torvalds 60014fe22e3SFlorian Westphal skb_shinfo(head)->frag_list = head->next; 601d56f90a7SArnaldo Carvalho de Melo skb_push(head, head->data - skb_network_header(head)); 6021da177e4SLinus Torvalds 60314fe22e3SFlorian Westphal for (fp=head->next; fp; fp = fp->next) { 60414fe22e3SFlorian Westphal head->data_len += fp->len; 60514fe22e3SFlorian Westphal head->len += fp->len; 6061da177e4SLinus Torvalds if (head->ip_summed != fp->ip_summed) 6071da177e4SLinus Torvalds head->ip_summed = CHECKSUM_NONE; 60884fa7933SPatrick McHardy else if (head->ip_summed == CHECKSUM_COMPLETE) 6091da177e4SLinus Torvalds head->csum = csum_add(head->csum, fp->csum); 6101da177e4SLinus Torvalds head->truesize += fp->truesize; 6111da177e4SLinus Torvalds } 6125510b3c2SDavid S. Miller sub_frag_mem_limit(qp->q.net, head->truesize); 6131da177e4SLinus Torvalds 6141da177e4SLinus Torvalds head->next = NULL; 6151da177e4SLinus Torvalds head->dev = dev; 6165ab11c98SPavel Emelyanov head->tstamp = qp->q.stamp; 617d6b915e2SFlorian Westphal IPCB(head)->frag_max_size = max(qp->max_df_size, qp->q.max_size); 6181da177e4SLinus Torvalds 619eddc9ec5SArnaldo Carvalho de Melo iph = ip_hdr(head); 6201da177e4SLinus Torvalds iph->tot_len = htons(len); 6215173cc05SEric Dumazet iph->tos |= ecn; 622d6b915e2SFlorian Westphal 623d6b915e2SFlorian Westphal /* When we set IP_DF on a refragmented skb we must also force a 624d6b915e2SFlorian Westphal * call to ip_fragment to avoid forwarding a DF-skb of size s while 625d6b915e2SFlorian Westphal * original sender only sent fragments of size f (where f < s). 626d6b915e2SFlorian Westphal * 627d6b915e2SFlorian Westphal * We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest 628d6b915e2SFlorian Westphal * frag seen to avoid sending tiny DF-fragments in case skb was built 629d6b915e2SFlorian Westphal * from one very small df-fragment and one large non-df frag. 630d6b915e2SFlorian Westphal */ 631d6b915e2SFlorian Westphal if (qp->max_df_size == qp->q.max_size) { 632d6b915e2SFlorian Westphal IPCB(head)->flags |= IPSKB_FRAG_PMTU; 633d6b915e2SFlorian Westphal iph->frag_off = htons(IP_DF); 634d6b915e2SFlorian Westphal } else { 635d6b915e2SFlorian Westphal iph->frag_off = 0; 636d6b915e2SFlorian Westphal } 637d6b915e2SFlorian Westphal 6380848f642SEdward Hyunkoo Jee ip_send_check(iph); 6390848f642SEdward Hyunkoo Jee 6402bad35b7SJorge Boncompte [DTI2] IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS); 6415ab11c98SPavel Emelyanov qp->q.fragments = NULL; 642d6bebca9SChangli Gao qp->q.fragments_tail = NULL; 6431706d587SHerbert Xu return 0; 6441da177e4SLinus Torvalds 6451da177e4SLinus Torvalds out_nomem: 646ba7a46f1SJoe Perches net_dbg_ratelimited("queue_glue: no memory for gluing queue %p\n", qp); 64745542479SDavid Howells err = -ENOMEM; 6481da177e4SLinus Torvalds goto out_fail; 6491da177e4SLinus Torvalds out_oversize: 650e87cc472SJoe Perches net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->saddr); 6511da177e4SLinus Torvalds out_fail: 652bbf31bf1SDavid Ford IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 6531706d587SHerbert Xu return err; 6541da177e4SLinus Torvalds } 6551da177e4SLinus Torvalds 6561da177e4SLinus Torvalds /* Process an incoming IP datagram fragment. */ 65719bcf9f2SEric W. Biederman int ip_defrag(struct net *net, struct sk_buff *skb, u32 user) 6581da177e4SLinus Torvalds { 6599972f134SDavid Ahern struct net_device *dev = skb->dev ? : skb_dst(skb)->dev; 660385add90SDavid Ahern int vif = l3mdev_master_ifindex_rcu(dev); 6611da177e4SLinus Torvalds struct ipq *qp; 6621da177e4SLinus Torvalds 6637c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS); 6648282f274SJoe Stringer skb_orphan(skb); 6651da177e4SLinus Torvalds 6661da177e4SLinus Torvalds /* Lookup (or create) queue header */ 6679972f134SDavid Ahern qp = ip_find(net, ip_hdr(skb), user, vif); 66800db4124SIan Morris if (qp) { 6691706d587SHerbert Xu int ret; 6701da177e4SLinus Torvalds 6715ab11c98SPavel Emelyanov spin_lock(&qp->q.lock); 6721da177e4SLinus Torvalds 6731706d587SHerbert Xu ret = ip_frag_queue(qp, skb); 6741da177e4SLinus Torvalds 6755ab11c98SPavel Emelyanov spin_unlock(&qp->q.lock); 6764b6cb5d8SPavel Emelyanov ipq_put(qp); 677776c729eSHerbert Xu return ret; 6781da177e4SLinus Torvalds } 6791da177e4SLinus Torvalds 6807c73a6faSPavel Emelyanov IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); 6811da177e4SLinus Torvalds kfree_skb(skb); 682776c729eSHerbert Xu return -ENOMEM; 6831da177e4SLinus Torvalds } 6844bc2f18bSEric Dumazet EXPORT_SYMBOL(ip_defrag); 6851da177e4SLinus Torvalds 68619bcf9f2SEric W. Biederman struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) 687bc416d97SEric Dumazet { 6881bf3751eSJohannes Berg struct iphdr iph; 6893e32e733SAlexander Drozdov int netoff; 690bc416d97SEric Dumazet u32 len; 691bc416d97SEric Dumazet 692bc416d97SEric Dumazet if (skb->protocol != htons(ETH_P_IP)) 693bc416d97SEric Dumazet return skb; 694bc416d97SEric Dumazet 6953e32e733SAlexander Drozdov netoff = skb_network_offset(skb); 6963e32e733SAlexander Drozdov 6973e32e733SAlexander Drozdov if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0) 698bc416d97SEric Dumazet return skb; 699bc416d97SEric Dumazet 7001bf3751eSJohannes Berg if (iph.ihl < 5 || iph.version != 4) 701bc416d97SEric Dumazet return skb; 702bc416d97SEric Dumazet 7031bf3751eSJohannes Berg len = ntohs(iph.tot_len); 7043e32e733SAlexander Drozdov if (skb->len < netoff + len || len < (iph.ihl * 4)) 7051bf3751eSJohannes Berg return skb; 7061bf3751eSJohannes Berg 7071bf3751eSJohannes Berg if (ip_is_fragment(&iph)) { 708bc416d97SEric Dumazet skb = skb_share_check(skb, GFP_ATOMIC); 709bc416d97SEric Dumazet if (skb) { 7103e32e733SAlexander Drozdov if (!pskb_may_pull(skb, netoff + iph.ihl * 4)) 7111bf3751eSJohannes Berg return skb; 7123e32e733SAlexander Drozdov if (pskb_trim_rcsum(skb, netoff + len)) 713bc416d97SEric Dumazet return skb; 714bc416d97SEric Dumazet memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); 71519bcf9f2SEric W. Biederman if (ip_defrag(net, skb, user)) 716bc416d97SEric Dumazet return NULL; 7177539fadcSTom Herbert skb_clear_hash(skb); 718bc416d97SEric Dumazet } 719bc416d97SEric Dumazet } 720bc416d97SEric Dumazet return skb; 721bc416d97SEric Dumazet } 722bc416d97SEric Dumazet EXPORT_SYMBOL(ip_check_defrag); 723bc416d97SEric Dumazet 7248d8354d2SPavel Emelyanov #ifdef CONFIG_SYSCTL 7258d8354d2SPavel Emelyanov static int zero; 7268d8354d2SPavel Emelyanov 7270a64b4b8SPavel Emelyanov static struct ctl_table ip4_frags_ns_ctl_table[] = { 7288d8354d2SPavel Emelyanov { 7298d8354d2SPavel Emelyanov .procname = "ipfrag_high_thresh", 730e31e0bdcSPavel Emelyanov .data = &init_net.ipv4.frags.high_thresh, 7318d8354d2SPavel Emelyanov .maxlen = sizeof(int), 7328d8354d2SPavel Emelyanov .mode = 0644, 7331bab4c75SNikolay Aleksandrov .proc_handler = proc_dointvec_minmax, 7341bab4c75SNikolay Aleksandrov .extra1 = &init_net.ipv4.frags.low_thresh 7358d8354d2SPavel Emelyanov }, 7368d8354d2SPavel Emelyanov { 7378d8354d2SPavel Emelyanov .procname = "ipfrag_low_thresh", 738e31e0bdcSPavel Emelyanov .data = &init_net.ipv4.frags.low_thresh, 7398d8354d2SPavel Emelyanov .maxlen = sizeof(int), 7408d8354d2SPavel Emelyanov .mode = 0644, 7411bab4c75SNikolay Aleksandrov .proc_handler = proc_dointvec_minmax, 7421bab4c75SNikolay Aleksandrov .extra1 = &zero, 7431bab4c75SNikolay Aleksandrov .extra2 = &init_net.ipv4.frags.high_thresh 7448d8354d2SPavel Emelyanov }, 7458d8354d2SPavel Emelyanov { 7468d8354d2SPavel Emelyanov .procname = "ipfrag_time", 747b2fd5321SPavel Emelyanov .data = &init_net.ipv4.frags.timeout, 7488d8354d2SPavel Emelyanov .maxlen = sizeof(int), 7498d8354d2SPavel Emelyanov .mode = 0644, 7506d9f239aSAlexey Dobriyan .proc_handler = proc_dointvec_jiffies, 7518d8354d2SPavel Emelyanov }, 7527d291ebbSPavel Emelyanov { } 7537d291ebbSPavel Emelyanov }; 7547d291ebbSPavel Emelyanov 755e3a57d18SFlorian Westphal /* secret interval has been deprecated */ 756e3a57d18SFlorian Westphal static int ip4_frags_secret_interval_unused; 7577d291ebbSPavel Emelyanov static struct ctl_table ip4_frags_ctl_table[] = { 7588d8354d2SPavel Emelyanov { 7598d8354d2SPavel Emelyanov .procname = "ipfrag_secret_interval", 760e3a57d18SFlorian Westphal .data = &ip4_frags_secret_interval_unused, 7618d8354d2SPavel Emelyanov .maxlen = sizeof(int), 7628d8354d2SPavel Emelyanov .mode = 0644, 7636d9f239aSAlexey Dobriyan .proc_handler = proc_dointvec_jiffies, 7648d8354d2SPavel Emelyanov }, 7658d8354d2SPavel Emelyanov { 7668d8354d2SPavel Emelyanov .procname = "ipfrag_max_dist", 7678d8354d2SPavel Emelyanov .data = &sysctl_ipfrag_max_dist, 7688d8354d2SPavel Emelyanov .maxlen = sizeof(int), 7698d8354d2SPavel Emelyanov .mode = 0644, 7706d9f239aSAlexey Dobriyan .proc_handler = proc_dointvec_minmax, 7718d8354d2SPavel Emelyanov .extra1 = &zero 7728d8354d2SPavel Emelyanov }, 7738d8354d2SPavel Emelyanov { } 7748d8354d2SPavel Emelyanov }; 7758d8354d2SPavel Emelyanov 7762c8c1e72SAlexey Dobriyan static int __net_init ip4_frags_ns_ctl_register(struct net *net) 7778d8354d2SPavel Emelyanov { 778e4a2d5c2SPavel Emelyanov struct ctl_table *table; 7798d8354d2SPavel Emelyanov struct ctl_table_header *hdr; 7808d8354d2SPavel Emelyanov 7810a64b4b8SPavel Emelyanov table = ip4_frags_ns_ctl_table; 78209ad9bc7SOctavian Purdila if (!net_eq(net, &init_net)) { 7830a64b4b8SPavel Emelyanov table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL); 78451456b29SIan Morris if (!table) 785e4a2d5c2SPavel Emelyanov goto err_alloc; 786e4a2d5c2SPavel Emelyanov 787e31e0bdcSPavel Emelyanov table[0].data = &net->ipv4.frags.high_thresh; 7881bab4c75SNikolay Aleksandrov table[0].extra1 = &net->ipv4.frags.low_thresh; 7891bab4c75SNikolay Aleksandrov table[0].extra2 = &init_net.ipv4.frags.high_thresh; 790e31e0bdcSPavel Emelyanov table[1].data = &net->ipv4.frags.low_thresh; 7911bab4c75SNikolay Aleksandrov table[1].extra2 = &net->ipv4.frags.high_thresh; 792b2fd5321SPavel Emelyanov table[2].data = &net->ipv4.frags.timeout; 793464dc801SEric W. Biederman 794464dc801SEric W. Biederman /* Don't export sysctls to unprivileged users */ 795464dc801SEric W. Biederman if (net->user_ns != &init_user_ns) 796464dc801SEric W. Biederman table[0].procname = NULL; 797e4a2d5c2SPavel Emelyanov } 798e4a2d5c2SPavel Emelyanov 799ec8f23ceSEric W. Biederman hdr = register_net_sysctl(net, "net/ipv4", table); 80051456b29SIan Morris if (!hdr) 801e4a2d5c2SPavel Emelyanov goto err_reg; 802e4a2d5c2SPavel Emelyanov 803e4a2d5c2SPavel Emelyanov net->ipv4.frags_hdr = hdr; 804e4a2d5c2SPavel Emelyanov return 0; 805e4a2d5c2SPavel Emelyanov 806e4a2d5c2SPavel Emelyanov err_reg: 80709ad9bc7SOctavian Purdila if (!net_eq(net, &init_net)) 808e4a2d5c2SPavel Emelyanov kfree(table); 809e4a2d5c2SPavel Emelyanov err_alloc: 810e4a2d5c2SPavel Emelyanov return -ENOMEM; 811e4a2d5c2SPavel Emelyanov } 812e4a2d5c2SPavel Emelyanov 8132c8c1e72SAlexey Dobriyan static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net) 814e4a2d5c2SPavel Emelyanov { 815e4a2d5c2SPavel Emelyanov struct ctl_table *table; 816e4a2d5c2SPavel Emelyanov 817e4a2d5c2SPavel Emelyanov table = net->ipv4.frags_hdr->ctl_table_arg; 818e4a2d5c2SPavel Emelyanov unregister_net_sysctl_table(net->ipv4.frags_hdr); 819e4a2d5c2SPavel Emelyanov kfree(table); 8208d8354d2SPavel Emelyanov } 8217d291ebbSPavel Emelyanov 82257a02c39SFabian Frederick static void __init ip4_frags_ctl_register(void) 8237d291ebbSPavel Emelyanov { 82443444757SEric W. Biederman register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table); 8257d291ebbSPavel Emelyanov } 8268d8354d2SPavel Emelyanov #else 827aa1f731eSFabian Frederick static int ip4_frags_ns_ctl_register(struct net *net) 8288d8354d2SPavel Emelyanov { 8298d8354d2SPavel Emelyanov return 0; 8308d8354d2SPavel Emelyanov } 831e4a2d5c2SPavel Emelyanov 832aa1f731eSFabian Frederick static void ip4_frags_ns_ctl_unregister(struct net *net) 833e4a2d5c2SPavel Emelyanov { 834e4a2d5c2SPavel Emelyanov } 8357d291ebbSPavel Emelyanov 836aa1f731eSFabian Frederick static void __init ip4_frags_ctl_register(void) 8377d291ebbSPavel Emelyanov { 8387d291ebbSPavel Emelyanov } 8398d8354d2SPavel Emelyanov #endif 8408d8354d2SPavel Emelyanov 8412c8c1e72SAlexey Dobriyan static int __net_init ipv4_frags_init_net(struct net *net) 8428d8354d2SPavel Emelyanov { 8431d6119baSEric Dumazet int res; 8441d6119baSEric Dumazet 845c2a93660SJesper Dangaard Brouer /* Fragment cache limits. 846c2a93660SJesper Dangaard Brouer * 847c2a93660SJesper Dangaard Brouer * The fragment memory accounting code, (tries to) account for 848c2a93660SJesper Dangaard Brouer * the real memory usage, by measuring both the size of frag 849c2a93660SJesper Dangaard Brouer * queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue)) 850c2a93660SJesper Dangaard Brouer * and the SKB's truesize. 851c2a93660SJesper Dangaard Brouer * 852c2a93660SJesper Dangaard Brouer * A 64K fragment consumes 129736 bytes (44*2944)+200 853c2a93660SJesper Dangaard Brouer * (1500 truesize == 2944, sizeof(struct ipq) == 200) 854c2a93660SJesper Dangaard Brouer * 855c2a93660SJesper Dangaard Brouer * We will commit 4MB at one time. Should we cross that limit 856c2a93660SJesper Dangaard Brouer * we will prune down to 3MB, making room for approx 8 big 64K 857c2a93660SJesper Dangaard Brouer * fragments 8x128k. 858e31e0bdcSPavel Emelyanov */ 859c2a93660SJesper Dangaard Brouer net->ipv4.frags.high_thresh = 4 * 1024 * 1024; 860c2a93660SJesper Dangaard Brouer net->ipv4.frags.low_thresh = 3 * 1024 * 1024; 861e31e0bdcSPavel Emelyanov /* 862b2fd5321SPavel Emelyanov * Important NOTE! Fragment queue must be destroyed before MSL expires. 863b2fd5321SPavel Emelyanov * RFC791 is wrong proposing to prolongate timer each fragment arrival 864b2fd5321SPavel Emelyanov * by TTL. 865b2fd5321SPavel Emelyanov */ 866b2fd5321SPavel Emelyanov net->ipv4.frags.timeout = IP_FRAG_TIME; 867b2fd5321SPavel Emelyanov 8681d6119baSEric Dumazet res = inet_frags_init_net(&net->ipv4.frags); 8691d6119baSEric Dumazet if (res) 8701d6119baSEric Dumazet return res; 8711d6119baSEric Dumazet res = ip4_frags_ns_ctl_register(net); 8721d6119baSEric Dumazet if (res) 8731d6119baSEric Dumazet inet_frags_uninit_net(&net->ipv4.frags); 8741d6119baSEric Dumazet return res; 8758d8354d2SPavel Emelyanov } 8768d8354d2SPavel Emelyanov 8772c8c1e72SAlexey Dobriyan static void __net_exit ipv4_frags_exit_net(struct net *net) 87881566e83SPavel Emelyanov { 8790a64b4b8SPavel Emelyanov ip4_frags_ns_ctl_unregister(net); 88081566e83SPavel Emelyanov inet_frags_exit_net(&net->ipv4.frags, &ip4_frags); 88181566e83SPavel Emelyanov } 88281566e83SPavel Emelyanov 88381566e83SPavel Emelyanov static struct pernet_operations ip4_frags_ops = { 88481566e83SPavel Emelyanov .init = ipv4_frags_init_net, 88581566e83SPavel Emelyanov .exit = ipv4_frags_exit_net, 88681566e83SPavel Emelyanov }; 88781566e83SPavel Emelyanov 888b7aa0bf7SEric Dumazet void __init ipfrag_init(void) 8891da177e4SLinus Torvalds { 8907d291ebbSPavel Emelyanov ip4_frags_ctl_register(); 89181566e83SPavel Emelyanov register_pernet_subsys(&ip4_frags_ops); 892321a3a99SPavel Emelyanov ip4_frags.hashfn = ip4_hashfn; 893c6fda282SPavel Emelyanov ip4_frags.constructor = ip4_frag_init; 8941e4b8287SPavel Emelyanov ip4_frags.destructor = ip4_frag_free; 8951e4b8287SPavel Emelyanov ip4_frags.qsize = sizeof(struct ipq); 896abd6523dSPavel Emelyanov ip4_frags.match = ip4_frag_match; 897e521db9dSPavel Emelyanov ip4_frags.frag_expire = ip_expire; 898d4ad4d22SNikolay Aleksandrov ip4_frags.frags_cache_name = ip_frag_cache_name; 899d4ad4d22SNikolay Aleksandrov if (inet_frags_init(&ip4_frags)) 900d4ad4d22SNikolay Aleksandrov panic("IP: failed to allocate ip4_frags cache\n"); 9011da177e4SLinus Torvalds } 902