tcp: fix corner case issue in segmentation during rexmitting
[safe/jmp/linux-2.6] / net / ipv4 / udp.c
index db313d9..4bd178a 100644 (file)
@@ -5,12 +5,10 @@
  *
  *             The User Datagram Protocol (UDP).
  *
- * Version:    $Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $
- *
  * Authors:    Ross Biro
  *             Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  *             Arnt Gulbrandsen, <agulbra@nvg.unit.no>
- *             Alan Cox, <Alan.Cox@linux.org>
+ *             Alan Cox, <alan@lxorguk.ukuu.org.uk>
  *             Hirokazu Takahashi, <taka@valinux.co.jp>
  *
  * Fixes:
@@ -70,6 +68,7 @@
  *     Alexey Kuznetsov:               allow both IPv4 and IPv6 sockets to bind
  *                                     a single port at the same time.
  *     Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
+ *     James Chapman           :       Add L2TP encapsulation type.
  *
  *
  *             This program is free software; you can redistribute it and/or
@@ -81,6 +80,9 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/swap.h>
 #include <linux/types.h>
 #include <linux/fcntl.h>
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <net/net_namespace.h>
 #include <net/icmp.h>
 #include <net/route.h>
 #include <net/checksum.h>
 #include <net/xfrm.h>
 #include "udp_impl.h"
 
-/*
- *     Snmp MIB for the UDP layer
- */
+struct udp_table udp_table;
+EXPORT_SYMBOL(udp_table);
 
-DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly;
+int sysctl_udp_mem[3] __read_mostly;
+int sysctl_udp_rmem_min __read_mostly;
+int sysctl_udp_wmem_min __read_mostly;
 
-struct hlist_head udp_hash[UDP_HTABLE_SIZE];
-DEFINE_RWLOCK(udp_hash_lock);
+EXPORT_SYMBOL(sysctl_udp_mem);
+EXPORT_SYMBOL(sysctl_udp_rmem_min);
+EXPORT_SYMBOL(sysctl_udp_wmem_min);
 
-static int udp_port_rover;
+atomic_t udp_memory_allocated;
+EXPORT_SYMBOL(udp_memory_allocated);
 
-/*
- * Note about this hash function :
- * Typical use is probably daddr = 0, only dport is going to vary hash
- */
-static inline unsigned int hash_port_and_addr(__u16 port, __be32 addr)
-{
-       addr ^= addr >> 16;
-       addr ^= addr >> 8;
-       return port ^ addr;
-}
+#define PORTS_PER_CHAIN (65536 / UDP_HTABLE_SIZE)
 
-static inline int __udp_lib_port_inuse(unsigned int hash, int port,
-       __be32 daddr, struct hlist_head udptable[])
+static int udp_lib_lport_inuse(struct net *net, __u16 num,
+                              const struct udp_hslot *hslot,
+                              unsigned long *bitmap,
+                              struct sock *sk,
+                              int (*saddr_comp)(const struct sock *sk1,
+                                                const struct sock *sk2))
 {
-       struct sock *sk;
-       struct hlist_node *node;
-       struct inet_sock *inet;
-
-       sk_for_each(sk, node, &udptable[hash & (UDP_HTABLE_SIZE - 1)]) {
-               if (sk->sk_hash != hash)
-                       continue;
-               inet = inet_sk(sk);
-               if (inet->num != port)
-                       continue;
-               if (inet->rcv_saddr == daddr)
-                       return 1;
-       }
+       struct sock *sk2;
+       struct hlist_nulls_node *node;
+
+       sk_nulls_for_each(sk2, node, &hslot->head)
+               if (net_eq(sock_net(sk2), net)                  &&
+                   sk2 != sk                                   &&
+                   (bitmap || sk2->sk_hash == num)             &&
+                   (!sk2->sk_reuse || !sk->sk_reuse)           &&
+                   (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
+                       || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+                   (*saddr_comp)(sk, sk2)) {
+                       if (bitmap)
+                               __set_bit(sk2->sk_hash / UDP_HTABLE_SIZE,
+                                         bitmap);
+                       else
+                               return 1;
+               }
        return 0;
 }
 
 /**
- *  __udp_lib_get_port  -  UDP/-Lite port lookup for IPv4 and IPv6
+ *  udp_lib_get_port  -  UDP/-Lite port lookup for IPv4 and IPv6
  *
  *  @sk:          socket struct in question
  *  @snum:        port number to look up
- *  @udptable:    hash list table, must be of UDP_HTABLE_SIZE
- *  @port_rover:  pointer to record of last unallocated port
  *  @saddr_comp:  AF-dependent comparison of bound local IP addresses
  */
-int __udp_lib_get_port(struct sock *sk, unsigned short snum,
-                      struct hlist_head udptable[], int *port_rover,
+int udp_lib_get_port(struct sock *sk, unsigned short snum,
                       int (*saddr_comp)(const struct sock *sk1,
                                         const struct sock *sk2 )    )
 {
-       struct hlist_node *node;
-       struct hlist_head *head;
-       struct sock *sk2;
-       unsigned int hash;
+       struct udp_hslot *hslot;
+       struct udp_table *udptable = sk->sk_prot->h.udp_table;
        int    error = 1;
+       struct net *net = sock_net(sk);
 
-       write_lock_bh(&udp_hash_lock);
-       if (snum == 0) {
-               int best_size_so_far, best, result, i;
-
-               if (*port_rover > sysctl_local_port_range[1] ||
-                   *port_rover < sysctl_local_port_range[0])
-                       *port_rover = sysctl_local_port_range[0];
-               best_size_so_far = 32767;
-               best = result = *port_rover;
-               for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
-                       int size;
-
-                       hash = hash_port_and_addr(result,
-                                       inet_sk(sk)->rcv_saddr);
-                       head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
-                       if (hlist_empty(head)) {
-                               if (result > sysctl_local_port_range[1])
-                                       result = sysctl_local_port_range[0] +
-                                               ((result - sysctl_local_port_range[0]) &
-                                                (UDP_HTABLE_SIZE - 1));
-                               goto gotit;
-                       }
-                       size = 0;
-                       sk_for_each(sk2, node, head) {
-                               if (++size >= best_size_so_far)
-                                       goto next;
-                       }
-                       best_size_so_far = size;
-                       best = result;
-               next:
-                       ;
-               }
-               result = best;
-               for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE;
-                    i++, result += UDP_HTABLE_SIZE) {
-                       if (result > sysctl_local_port_range[1])
-                               result = sysctl_local_port_range[0]
-                                       + ((result - sysctl_local_port_range[0]) &
-                                          (UDP_HTABLE_SIZE - 1));
-                       hash = hash_port_and_addr(result,
-                                       inet_sk(sk)->rcv_saddr);
-                       if (! __udp_lib_port_inuse(hash, result,
-                               inet_sk(sk)->rcv_saddr, udptable))
-                               break;
+       if (!snum) {
+               int low, high, remaining;
+               unsigned rand;
+               unsigned short first, last;
+               DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
+
+               inet_get_local_port_range(&low, &high);
+               remaining = (high - low) + 1;
+
+               rand = net_random();
+               first = (((u64)rand * remaining) >> 32) + low;
+               /*
+                * force rand to be an odd multiple of UDP_HTABLE_SIZE
+                */
+               rand = (rand | 1) * UDP_HTABLE_SIZE;
+               for (last = first + UDP_HTABLE_SIZE; first != last; first++) {
+                       hslot = &udptable->hash[udp_hashfn(net, first)];
+                       bitmap_zero(bitmap, PORTS_PER_CHAIN);
+                       spin_lock_bh(&hslot->lock);
+                       udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
+                                           saddr_comp);
+
+                       snum = first;
+                       /*
+                        * Iterate on all possible values of snum for this hash.
+                        * Using steps of an odd multiple of UDP_HTABLE_SIZE
+                        * give us randomization and full range coverage.
+                        */
+                       do {
+                               if (low <= snum && snum <= high &&
+                                   !test_bit(snum / UDP_HTABLE_SIZE, bitmap))
+                                       goto found;
+                               snum += rand;
+                       } while (snum != first);
+                       spin_unlock_bh(&hslot->lock);
                }
-               if (i >= (1 << 16) / UDP_HTABLE_SIZE)
-                       goto fail;
-gotit:
-               *port_rover = snum = result;
+               goto fail;
        } else {
-               hash = hash_port_and_addr(snum, inet_sk(sk)->rcv_saddr);
-               head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
-
-               sk_for_each(sk2, node, head)
-                       if (sk2->sk_hash == hash                             &&
-                           sk2 != sk                                        &&
-                           inet_sk(sk2)->num == snum                        &&
-                           (!sk2->sk_reuse        || !sk->sk_reuse)         &&
-                           (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
-                            || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
-                           (*saddr_comp)(sk, sk2)                             )
-                               goto fail;
+               hslot = &udptable->hash[udp_hashfn(net, snum)];
+               spin_lock_bh(&hslot->lock);
+               if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, saddr_comp))
+                       goto fail_unlock;
        }
+found:
        inet_sk(sk)->num = snum;
-       sk->sk_hash = hash;
+       sk->sk_hash = snum;
        if (sk_unhashed(sk)) {
-               head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
-               sk_add_node(sk, head);
-               sock_prot_inc_use(sk->sk_prot);
+               sk_nulls_add_node_rcu(sk, &hslot->head);
+               sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
        }
        error = 0;
+fail_unlock:
+       spin_unlock_bh(&hslot->lock);
 fail:
-       write_unlock_bh(&udp_hash_lock);
        return error;
 }
 
-int udp_get_port(struct sock *sk, unsigned short snum,
-                       int (*scmp)(const struct sock *, const struct sock *))
-{
-       return  __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, scmp);
-}
-
-int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
+static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
 {
        struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
 
@@ -255,91 +231,129 @@ int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
                   inet1->rcv_saddr == inet2->rcv_saddr      ));
 }
 
-static inline int udp_v4_get_port(struct sock *sk, unsigned short snum)
+int udp_v4_get_port(struct sock *sk, unsigned short snum)
 {
-       return udp_get_port(sk, snum, ipv4_rcv_saddr_equal);
+       return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
 }
 
-/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
- * harder than this. -DaveM
- */
-static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport,
-                                     __be32 daddr, __be16 dport,
-                                     int dif, struct hlist_head udptable[])
+static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
+                        unsigned short hnum,
+                        __be16 sport, __be32 daddr, __be16 dport, int dif)
 {
-       struct sock *sk, *result = NULL;
-       struct hlist_node *node;
-       unsigned int hash, hashwild;
-       int score, best = -1, hport = ntohs(dport);
+       int score = -1;
 
-       hash = hash_port_and_addr(hport, daddr);
-       hashwild = hash_port_and_addr(hport, 0);
-
-       read_lock(&udp_hash_lock);
-
-lookup:
-
-       sk_for_each(sk, node, &udptable[hash & (UDP_HTABLE_SIZE - 1)]) {
+       if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
+                       !ipv6_only_sock(sk)) {
                struct inet_sock *inet = inet_sk(sk);
 
-               if (sk->sk_hash != hash || ipv6_only_sock(sk) ||
-                       inet->num != hport)
-                       continue;
-
                score = (sk->sk_family == PF_INET ? 1 : 0);
                if (inet->rcv_saddr) {
                        if (inet->rcv_saddr != daddr)
-                               continue;
-                       score+=2;
+                               return -1;
+                       score += 2;
                }
                if (inet->daddr) {
                        if (inet->daddr != saddr)
-                               continue;
-                       score+=2;
+                               return -1;
+                       score += 2;
                }
                if (inet->dport) {
                        if (inet->dport != sport)
-                               continue;
-                       score+=2;
+                               return -1;
+                       score += 2;
                }
                if (sk->sk_bound_dev_if) {
                        if (sk->sk_bound_dev_if != dif)
-                               continue;
-                       score+=2;
+                               return -1;
+                       score += 2;
                }
-               if (score == 9) {
-                       result = sk;
-                       goto found;
-               } else if (score > best) {
+       }
+       return score;
+}
+
+/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
+ * harder than this. -DaveM
+ */
+static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
+               __be16 sport, __be32 daddr, __be16 dport,
+               int dif, struct udp_table *udptable)
+{
+       struct sock *sk, *result;
+       struct hlist_nulls_node *node;
+       unsigned short hnum = ntohs(dport);
+       unsigned int hash = udp_hashfn(net, hnum);
+       struct udp_hslot *hslot = &udptable->hash[hash];
+       int score, badness;
+
+       rcu_read_lock();
+begin:
+       result = NULL;
+       badness = -1;
+       sk_nulls_for_each_rcu(sk, node, &hslot->head) {
+               score = compute_score(sk, net, saddr, hnum, sport,
+                                     daddr, dport, dif);
+               if (score > badness) {
                        result = sk;
-                       best = score;
+                       badness = score;
                }
        }
-
-       if (hash != hashwild) {
-               hash = hashwild;
-               goto lookup;
+       /*
+        * if the nulls value we got at the end of this lookup is
+        * not the expected one, we must restart lookup.
+        * We probably met an item that was moved to another chain.
+        */
+       if (get_nulls_value(node) != hash)
+               goto begin;
+
+       if (result) {
+               if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
+                       result = NULL;
+               else if (unlikely(compute_score(result, net, saddr, hnum, sport,
+                                 daddr, dport, dif) < badness)) {
+                       sock_put(result);
+                       goto begin;
+               }
        }
-found:
-       if (result)
-               sock_hold(result);
-       read_unlock(&udp_hash_lock);
+       rcu_read_unlock();
        return result;
 }
 
-static inline struct sock *udp_v4_mcast_next(struct sock *sk, unsigned int hnum,
-                                            int hport, __be32 loc_addr,
+static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
+                                                __be16 sport, __be16 dport,
+                                                struct udp_table *udptable)
+{
+       struct sock *sk;
+       const struct iphdr *iph = ip_hdr(skb);
+
+       if (unlikely(sk = skb_steal_sock(skb)))
+               return sk;
+       else
+               return __udp4_lib_lookup(dev_net(skb->dst->dev), iph->saddr, sport,
+                                        iph->daddr, dport, inet_iif(skb),
+                                        udptable);
+}
+
+struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
+                            __be32 daddr, __be16 dport, int dif)
+{
+       return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
+}
+EXPORT_SYMBOL_GPL(udp4_lib_lookup);
+
+static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
+                                            __be16 loc_port, __be32 loc_addr,
                                             __be16 rmt_port, __be32 rmt_addr,
                                             int dif)
 {
-       struct hlist_node *node;
+       struct hlist_nulls_node *node;
        struct sock *s = sk;
+       unsigned short hnum = ntohs(loc_port);
 
-       sk_for_each_from(s, node) {
+       sk_nulls_for_each_from(s, node) {
                struct inet_sock *inet = inet_sk(s);
 
-               if (s->sk_hash != hnum                                  ||
-                   inet->num != hport                                  ||
+               if (!net_eq(sock_net(s), net)                           ||
+                   s->sk_hash != hnum                                  ||
                    (inet->daddr && inet->daddr != rmt_addr)            ||
                    (inet->dport != rmt_port && inet->dport)            ||
                    (inet->rcv_saddr && inet->rcv_saddr != loc_addr)    ||
@@ -366,7 +380,7 @@ found:
  * to find the appropriate port.
  */
 
-void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
+void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
 {
        struct inet_sock *inet;
        struct iphdr *iph = (struct iphdr*)skb->data;
@@ -376,11 +390,12 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
        struct sock *sk;
        int harderr;
        int err;
+       struct net *net = dev_net(skb->dev);
 
-       sk = __udp4_lib_lookup(iph->daddr, uh->dest, iph->saddr, uh->source,
-                              skb->dev->ifindex, udptable                  );
+       sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
+                       iph->saddr, uh->source, skb->dev->ifindex, udptable);
        if (sk == NULL) {
-               ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+               ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
                return; /* No socket for error */
        }
 
@@ -434,13 +449,13 @@ out:
 
 void udp_err(struct sk_buff *skb, u32 info)
 {
-       return __udp4_lib_err(skb, info, udp_hash);
+       __udp4_lib_err(skb, info, &udp_table);
 }
 
 /*
  * Throw away all pending data and cancel the corking. Socket is locked.
  */
-static void udp_flush_pending_frames(struct sock *sk)
+void udp_flush_pending_frames(struct sock *sk)
 {
        struct udp_sock *up = udp_sk(sk);
 
@@ -450,6 +465,7 @@ static void udp_flush_pending_frames(struct sock *sk)
                ip_flush_pending_frames(sk);
        }
 }
+EXPORT_SYMBOL(udp_flush_pending_frames);
 
 /**
  *     udp4_hwcsum_outgoing  -  handle outgoing HW checksumming
@@ -503,6 +519,7 @@ static int udp_push_pending_frames(struct sock *sk)
        struct sk_buff *skb;
        struct udphdr *uh;
        int err = 0;
+       int is_udplite = IS_UDPLITE(sk);
        __wsum csum = 0;
 
        /* Grab the skbuff where UDP header space exists. */
@@ -518,7 +535,7 @@ static int udp_push_pending_frames(struct sock *sk)
        uh->len = htons(up->len);
        uh->check = 0;
 
-       if (up->pcflag)                                  /*     UDP-Lite      */
+       if (is_udplite)                                  /*     UDP-Lite      */
                csum  = udplite_csum_outgoing(sk, skb);
 
        else if (sk->sk_no_check == UDP_CSUM_NOXMIT) {   /* UDP csum disabled */
@@ -545,6 +562,9 @@ send:
 out:
        up->len = 0;
        up->pending = 0;
+       if (!err)
+               UDP_INC_STATS_USER(sock_net(sk),
+                               UDP_MIB_OUTDATAGRAMS, is_udplite);
        return err;
 }
 
@@ -561,7 +581,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
        __be32 daddr, faddr, saddr;
        __be16 dport;
        u8  tos;
-       int err, is_udplite = up->pcflag;
+       int err, is_udplite = IS_UDPLITE(sk);
        int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
        int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
 
@@ -576,6 +596,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                return -EOPNOTSUPP;
 
        ipc.opt = NULL;
+       ipc.shtx.flags = 0;
 
        if (up->pending) {
                /*
@@ -623,8 +644,11 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
        ipc.addr = inet->saddr;
 
        ipc.oif = sk->sk_bound_dev_if;
+       err = sock_tx_timestamp(msg, sk, &ipc.shtx);
+       if (err)
+               return err;
        if (msg->msg_controllen) {
-               err = ip_cmsg_send(msg, &ipc);
+               err = ip_cmsg_send(sock_net(sk), msg, &ipc);
                if (err)
                        return err;
                if (ipc.opt)
@@ -651,7 +675,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                connected = 0;
        }
 
-       if (MULTICAST(daddr)) {
+       if (ipv4_is_multicast(daddr)) {
                if (!ipc.oif)
                        ipc.oif = inet->mc_index;
                if (!saddr)
@@ -669,13 +693,19 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                                                .saddr = saddr,
                                                .tos = tos } },
                                    .proto = sk->sk_protocol,
+                                   .flags = inet_sk_flowi_flags(sk),
                                    .uli_u = { .ports =
                                               { .sport = inet->sport,
                                                 .dport = dport } } };
+               struct net *net = sock_net(sk);
+
                security_sk_classify_flow(sk, &fl);
-               err = ip_route_output_flow(&rt, &fl, sk, 1);
-               if (err)
+               err = ip_route_output_flow(net, &rt, &fl, sk, 1);
+               if (err) {
+                       if (err == -ENETUNREACH)
+                               IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
                        goto out;
+               }
 
                err = -EACCES;
                if ((rt->rt_flags & RTCF_BROADCAST) &&
@@ -716,7 +746,7 @@ do_append_data:
        up->len += ulen;
        getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
        err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
-                       sizeof(struct udphdr), &ipc, rt,
+                       sizeof(struct udphdr), &ipc, &rt,
                        corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
        if (err)
                udp_flush_pending_frames(sk);
@@ -730,10 +760,8 @@ out:
        ip_rt_put(rt);
        if (free)
                kfree(ipc.opt);
-       if (!err) {
-               UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
+       if (!err)
                return len;
-       }
        /*
         * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
         * ENOBUFS might not be good (it's not tunable per se), but otherwise
@@ -742,7 +770,8 @@ out:
         * seems like overkill.
         */
        if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
-               UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
+               UDP_INC_STATS_USER(sock_net(sk),
+                               UDP_MIB_SNDBUFERRORS, is_udplite);
        }
        return err;
 
@@ -854,6 +883,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
        struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
        struct sk_buff *skb;
        unsigned int ulen, copied;
+       int peeked;
        int err;
        int is_udplite = IS_UDPLITE(sk);
 
@@ -867,7 +897,8 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                return ip_recv_error(sk, msg, len);
 
 try_again:
-       skb = skb_recv_datagram(sk, flags, noblock, &err);
+       skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
+                                 &peeked, &err);
        if (!skb)
                goto out;
 
@@ -902,6 +933,10 @@ try_again:
        if (err)
                goto out_free;
 
+       if (!peeked)
+               UDP_INC_STATS_USER(sock_net(sk),
+                               UDP_MIB_INDATAGRAMS, is_udplite);
+
        sock_recv_timestamp(msg, sk, skb);
 
        /* Copy the address. */
@@ -920,14 +955,17 @@ try_again:
                err = ulen;
 
 out_free:
+       lock_sock(sk);
        skb_free_datagram(sk, skb);
+       release_sock(sk);
 out:
        return err;
 
 csum_copy_err:
-       UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
-
-       skb_kill_datagram(sk, skb, flags);
+       lock_sock(sk);
+       if (!skb_kill_datagram(sk, skb, flags))
+               UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+       release_sock(sk);
 
        if (noblock)
                return -EAGAIN;
@@ -957,102 +995,44 @@ int udp_disconnect(struct sock *sk, int flags)
        return 0;
 }
 
-/* return:
- *     1  if the the UDP system should process it
- *     0  if we should drop this packet
- *     -1 if it should get processed by xfrm4_rcv_encap
- */
-static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
+void udp_lib_unhash(struct sock *sk)
 {
-#ifndef CONFIG_XFRM
-       return 1;
-#else
-       struct udp_sock *up = udp_sk(sk);
-       struct udphdr *uh;
-       struct iphdr *iph;
-       int iphlen, len;
-
-       __u8 *udpdata;
-       __be32 *udpdata32;
-       __u16 encap_type = up->encap_type;
-
-       /* if we're overly short, let UDP handle it */
-       len = skb->len - sizeof(struct udphdr);
-       if (len <= 0)
-               return 1;
-
-       /* if this is not encapsulated socket, then just return now */
-       if (!encap_type)
-               return 1;
-
-       /* If this is a paged skb, make sure we pull up
-        * whatever data we need to look at. */
-       if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
-               return 1;
-
-       /* Now we can get the pointers */
-       uh = udp_hdr(skb);
-       udpdata = (__u8 *)uh + sizeof(struct udphdr);
-       udpdata32 = (__be32 *)udpdata;
-
-       switch (encap_type) {
-       default:
-       case UDP_ENCAP_ESPINUDP:
-               /* Check if this is a keepalive packet.  If so, eat it. */
-               if (len == 1 && udpdata[0] == 0xff) {
-                       return 0;
-               } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
-                       /* ESP Packet without Non-ESP header */
-                       len = sizeof(struct udphdr);
-               } else
-                       /* Must be an IKE packet.. pass it through */
-                       return 1;
-               break;
-       case UDP_ENCAP_ESPINUDP_NON_IKE:
-               /* Check if this is a keepalive packet.  If so, eat it. */
-               if (len == 1 && udpdata[0] == 0xff) {
-                       return 0;
-               } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
-                          udpdata32[0] == 0 && udpdata32[1] == 0) {
-
-                       /* ESP Packet with Non-IKE marker */
-                       len = sizeof(struct udphdr) + 2 * sizeof(u32);
-               } else
-                       /* Must be an IKE packet.. pass it through */
-                       return 1;
-               break;
+       if (sk_hashed(sk)) {
+               struct udp_table *udptable = sk->sk_prot->h.udp_table;
+               unsigned int hash = udp_hashfn(sock_net(sk), sk->sk_hash);
+               struct udp_hslot *hslot = &udptable->hash[hash];
+
+               spin_lock_bh(&hslot->lock);
+               if (sk_nulls_del_node_init_rcu(sk)) {
+                       inet_sk(sk)->num = 0;
+                       sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+               }
+               spin_unlock_bh(&hslot->lock);
        }
+}
+EXPORT_SYMBOL(udp_lib_unhash);
 
-       /* At this point we are sure that this is an ESPinUDP packet,
-        * so we need to remove 'len' bytes from the packet (the UDP
-        * header and optional ESP marker bytes) and then modify the
-        * protocol to ESP, and then call into the transform receiver.
-        */
-       if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
-               return 0;
+static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+       int is_udplite = IS_UDPLITE(sk);
+       int rc;
 
-       /* Now we can update and verify the packet length... */
-       iph = ip_hdr(skb);
-       iphlen = iph->ihl << 2;
-       iph->tot_len = htons(ntohs(iph->tot_len) - len);
-       if (skb->len < iphlen + len) {
-               /* packet is too small!?! */
-               return 0;
+       if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) {
+               /* Note that an ENOMEM error is charged twice */
+               if (rc == -ENOMEM) {
+                       UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
+                                        is_udplite);
+                       atomic_inc(&sk->sk_drops);
+               }
+               goto drop;
        }
 
-       /* pull the data buffer up to the ESP header and set the
-        * transport header to point to ESP.  Keep UDP on the stack
-        * for later.
-        */
-       __skb_pull(skb, len);
-       skb_reset_transport_header(skb);
-
-       /* modify the protocol (it's ESP!) */
-       iph->protocol = IPPROTO_ESP;
+       return 0;
 
-       /* and let the caller know to send this into the ESP processor... */
+drop:
+       UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+       kfree_skb(skb);
        return -1;
-#endif
 }
 
 /* returns:
@@ -1067,6 +1047,7 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
 {
        struct udp_sock *up = udp_sk(sk);
        int rc;
+       int is_udplite = IS_UDPLITE(sk);
 
        /*
         *      Charge it to the socket, dropping if the queue is full.
@@ -1077,35 +1058,37 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
 
        if (up->encap_type) {
                /*
-                * This is an encapsulation socket, so let's see if this is
-                * an encapsulated packet.
-                * If it's a keepalive packet, then just eat it.
-                * If it's an encapsulateed packet, then pass it to the
-                * IPsec xfrm input and return the response
-                * appropriately.  Otherwise, just fall through and
-                * pass this up the UDP socket.
+                * This is an encapsulation socket so pass the skb to
+                * the socket's udp_encap_rcv() hook. Otherwise, just
+                * fall through and pass this up the UDP socket.
+                * up->encap_rcv() returns the following value:
+                * =0 if skb was successfully passed to the encap
+                *    handler or was discarded by it.
+                * >0 if skb should be passed on to UDP.
+                * <0 if skb should be resubmitted as proto -N
                 */
-               int ret;
 
-               ret = udp_encap_rcv(sk, skb);
-               if (ret == 0) {
-                       /* Eat the packet .. */
-                       kfree_skb(skb);
-                       return 0;
-               }
-               if (ret < 0) {
-                       /* process the ESP packet */
-                       ret = xfrm4_rcv_encap(skb, up->encap_type);
-                       UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
-                       return -ret;
+               /* if we're overly short, let UDP handle it */
+               if (skb->len > sizeof(struct udphdr) &&
+                   up->encap_rcv != NULL) {
+                       int ret;
+
+                       ret = (*up->encap_rcv)(sk, skb);
+                       if (ret <= 0) {
+                               UDP_INC_STATS_BH(sock_net(sk),
+                                                UDP_MIB_INDATAGRAMS,
+                                                is_udplite);
+                               return -ret;
+                       }
                }
+
                /* FALLTHROUGH -- it's a UDP Packet */
        }
 
        /*
         *      UDP-Lite specific tests, ignored on UDP sockets
         */
-       if ((up->pcflag & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
+       if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
 
                /*
                 * MIB statistics other than incrementing the error count are
@@ -1143,18 +1126,19 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
                        goto drop;
        }
 
-       if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
-               /* Note that an ENOMEM error is charged twice */
-               if (rc == -ENOMEM)
-                       UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
-               goto drop;
-       }
+       rc = 0;
 
-       UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
-       return 0;
+       bh_lock_sock(sk);
+       if (!sock_owned_by_user(sk))
+               rc = __udp_queue_rcv_skb(sk, skb);
+       else
+               sk_add_backlog(sk, skb);
+       bh_unlock_sock(sk);
+
+       return rc;
 
 drop:
-       UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
+       UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
        kfree_skb(skb);
        return -1;
 }
@@ -1165,57 +1149,43 @@ drop:
  *     Note: called only from the BH handler context,
  *     so we don't need to lock the hashes.
  */
-static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
+static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
                                    struct udphdr  *uh,
                                    __be32 saddr, __be32 daddr,
-                                   struct hlist_head udptable[])
+                                   struct udp_table *udptable)
 {
-       struct sock *sk, *skw, *sknext;
+       struct sock *sk;
+       struct udp_hslot *hslot = &udptable->hash[udp_hashfn(net, ntohs(uh->dest))];
        int dif;
-       int hport = ntohs(uh->dest);
-       unsigned int hash = hash_port_and_addr(hport, daddr);
-       unsigned int hashwild = hash_port_and_addr(hport, 0);
 
+       spin_lock(&hslot->lock);
+       sk = sk_nulls_head(&hslot->head);
        dif = skb->dev->ifindex;
-
-       read_lock(&udp_hash_lock);
-
-       sk = sk_head(&udptable[hash & (UDP_HTABLE_SIZE - 1)]);
-       skw = sk_head(&udptable[hashwild & (UDP_HTABLE_SIZE - 1)]);
-
-       sk = udp_v4_mcast_next(sk, hash, hport, daddr, uh->source, saddr, dif);
-       if (!sk) {
-               hash = hashwild;
-               sk = udp_v4_mcast_next(skw, hash, hport, daddr, uh->source,
-                       saddr, dif);
-       }
+       sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
        if (sk) {
+               struct sock *sknext = NULL;
+
                do {
                        struct sk_buff *skb1 = skb;
-                       sknext = udp_v4_mcast_next(sk_next(sk), hash, hport,
-                                               daddr, uh->source, saddr, dif);
-                       if (!sknext && hash != hashwild) {
-                               hash = hashwild;
-                               sknext = udp_v4_mcast_next(skw, hash, hport,
-                                       daddr, uh->source, saddr, dif);
-                       }
+
+                       sknext = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
+                                                  daddr, uh->source, saddr,
+                                                  dif);
                        if (sknext)
                                skb1 = skb_clone(skb, GFP_ATOMIC);
 
                        if (skb1) {
                                int ret = udp_queue_rcv_skb(sk, skb1);
                                if (ret > 0)
-                                       /*
-                                        * we should probably re-process
-                                        * instead of dropping packets here.
-                                        */
+                                       /* we should probably re-process instead
+                                        * of dropping packets here. */
                                        kfree_skb(skb1);
                        }
                        sk = sknext;
                } while (sknext);
        } else
                kfree_skb(skb);
-       read_unlock(&udp_hash_lock);
+       spin_unlock(&hslot->lock);
        return 0;
 }
 
@@ -1261,15 +1231,15 @@ static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
  *     All we need to do is get the socket, and then do a checksum.
  */
 
-int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
+int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
                   int proto)
 {
        struct sock *sk;
-       struct udphdr *uh = udp_hdr(skb);
+       struct udphdr *uh;
        unsigned short ulen;
        struct rtable *rt = (struct rtable*)skb->dst;
-       __be32 saddr = ip_hdr(skb)->saddr;
-       __be32 daddr = ip_hdr(skb)->daddr;
+       __be32 saddr, daddr;
+       struct net *net = dev_net(skb->dev);
 
        /*
         *  Validate the packet.
@@ -1277,6 +1247,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
        if (!pskb_may_pull(skb, sizeof(struct udphdr)))
                goto drop;              /* No space for header. */
 
+       uh   = udp_hdr(skb);
        ulen = ntohs(uh->len);
        if (ulen > skb->len)
                goto short_packet;
@@ -1291,11 +1262,14 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
        if (udp4_csum_init(skb, uh, proto))
                goto csum_error;
 
+       saddr = ip_hdr(skb)->saddr;
+       daddr = ip_hdr(skb)->daddr;
+
        if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
-               return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);
+               return __udp4_lib_mcast_deliver(net, skb, uh,
+                               saddr, daddr, udptable);
 
-       sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest,
-                              skb->dev->ifindex, udptable);
+       sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 
        if (sk != NULL) {
                int ret = udp_queue_rcv_skb(sk, skb);
@@ -1317,7 +1291,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
        if (udp_lib_checksum_complete(skb))
                goto csum_error;
 
-       UDP_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
+       UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 
        /*
@@ -1328,13 +1302,13 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
        return 0;
 
 short_packet:
-       LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
+       LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
                       proto == IPPROTO_UDPLITE ? "-Lite" : "",
-                      NIPQUAD(saddr),
+                      &saddr,
                       ntohs(uh->source),
                       ulen,
                       skb->len,
-                      NIPQUAD(daddr),
+                      &daddr,
                       ntohs(uh->dest));
        goto drop;
 
@@ -1343,30 +1317,29 @@ csum_error:
         * RFC1122: OK.  Discards the bad packet silently (as far as
         * the network is concerned, anyway) as per 4.1.3.4 (MUST).
         */
-       LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
+       LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
                       proto == IPPROTO_UDPLITE ? "-Lite" : "",
-                      NIPQUAD(saddr),
+                      &saddr,
                       ntohs(uh->source),
-                      NIPQUAD(daddr),
+                      &daddr,
                       ntohs(uh->dest),
                       ulen);
 drop:
-       UDP_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
+       UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
        kfree_skb(skb);
        return 0;
 }
 
 int udp_rcv(struct sk_buff *skb)
 {
-       return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
+       return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
 }
 
-int udp_destroy_sock(struct sock *sk)
+void udp_destroy_sock(struct sock *sk)
 {
        lock_sock(sk);
        udp_flush_pending_frames(sk);
        release_sock(sk);
-       return 0;
 }
 
 /*
@@ -1379,6 +1352,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
        struct udp_sock *up = udp_sk(sk);
        int val;
        int err = 0;
+       int is_udplite = IS_UDPLITE(sk);
 
        if (optlen<sizeof(int))
                return -EINVAL;
@@ -1403,6 +1377,9 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
                case 0:
                case UDP_ENCAP_ESPINUDP:
                case UDP_ENCAP_ESPINUDP_NON_IKE:
+                       up->encap_rcv = xfrm4_udp_encap_rcv;
+                       /* FALLTHROUGH */
+               case UDP_ENCAP_L2TPINUDP:
                        up->encap_type = val;
                        break;
                default:
@@ -1417,10 +1394,12 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
        /* The sender sets actual checksum coverage length via this option.
         * The case coverage > packet length is handled by send module. */
        case UDPLITE_SEND_CSCOV:
-               if (!up->pcflag)         /* Disable the option on UDP sockets */
+               if (!is_udplite)         /* Disable the option on UDP sockets */
                        return -ENOPROTOOPT;
                if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
                        val = 8;
+               else if (val > USHORT_MAX)
+                       val = USHORT_MAX;
                up->pcslen = val;
                up->pcflag |= UDPLITE_SEND_CC;
                break;
@@ -1429,10 +1408,12 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
         * sense, this should be set to at least 8 (as done below). If zero is
         * used, this again means full checksum coverage.                     */
        case UDPLITE_RECV_CSCOV:
-               if (!up->pcflag)         /* Disable the option on UDP sockets */
+               if (!is_udplite)         /* Disable the option on UDP sockets */
                        return -ENOPROTOOPT;
                if (val != 0 && val < 8) /* Avoid silly minimal values.       */
                        val = 8;
+               else if (val > USHORT_MAX)
+                       val = USHORT_MAX;
                up->pcrlen = val;
                up->pcflag |= UDPLITE_RECV_CC;
                break;
@@ -1555,7 +1536,8 @@ unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
                spin_lock_bh(&rcvq->lock);
                while ((skb = skb_peek(rcvq)) != NULL &&
                       udp_lib_checksum_complete(skb)) {
-                       UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite);
+                       UDP_INC_STATS_BH(sock_net(sk),
+                                       UDP_MIB_INERRORS, is_lite);
                        __skb_unlink(skb, rcvq);
                        kfree_skb(skb);
                }
@@ -1583,11 +1565,17 @@ struct proto udp_prot = {
        .sendmsg           = udp_sendmsg,
        .recvmsg           = udp_recvmsg,
        .sendpage          = udp_sendpage,
-       .backlog_rcv       = udp_queue_rcv_skb,
+       .backlog_rcv       = __udp_queue_rcv_skb,
        .hash              = udp_lib_hash,
        .unhash            = udp_lib_unhash,
        .get_port          = udp_v4_get_port,
+       .memory_allocated  = &udp_memory_allocated,
+       .sysctl_mem        = sysctl_udp_mem,
+       .sysctl_wmem       = &sysctl_udp_wmem_min,
+       .sysctl_rmem       = &sysctl_udp_rmem_min,
        .obj_size          = sizeof(struct udp_sock),
+       .slab_flags        = SLAB_DESTROY_BY_RCU,
+       .h.udp_table       = &udp_table,
 #ifdef CONFIG_COMPAT
        .compat_setsockopt = compat_udp_setsockopt,
        .compat_getsockopt = compat_udp_getsockopt,
@@ -1597,17 +1585,23 @@ struct proto udp_prot = {
 /* ------------------------------------------------------------------------ */
 #ifdef CONFIG_PROC_FS
 
-static struct sock *udp_get_first(struct seq_file *seq)
+static struct sock *udp_get_first(struct seq_file *seq, int start)
 {
        struct sock *sk;
        struct udp_iter_state *state = seq->private;
-
-       for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
-               struct hlist_node *node;
-               sk_for_each(sk, node, state->hashtable + state->bucket) {
+       struct net *net = seq_file_net(seq);
+
+       for (state->bucket = start; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
+               struct hlist_nulls_node *node;
+               struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
+               spin_lock_bh(&hslot->lock);
+               sk_nulls_for_each(sk, node, &hslot->head) {
+                       if (!net_eq(sock_net(sk), net))
+                               continue;
                        if (sk->sk_family == state->family)
                                goto found;
                }
+               spin_unlock_bh(&hslot->lock);
        }
        sk = NULL;
 found:
@@ -1617,23 +1611,22 @@ found:
 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
 {
        struct udp_iter_state *state = seq->private;
+       struct net *net = seq_file_net(seq);
 
        do {
-               sk = sk_next(sk);
-try_again:
-               ;
-       } while (sk && sk->sk_family != state->family);
+               sk = sk_nulls_next(sk);
+       } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
 
-       if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
-               sk = sk_head(state->hashtable + state->bucket);
-               goto try_again;
+       if (!sk) {
+               spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
+               return udp_get_first(seq, state->bucket + 1);
        }
        return sk;
 }
 
 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
 {
-       struct sock *sk = udp_get_first(seq);
+       struct sock *sk = udp_get_first(seq, 0);
 
        if (sk)
                while (pos && (sk = udp_get_next(seq, sk)) != NULL)
@@ -1643,15 +1636,14 @@ static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
 
 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
 {
-       read_lock(&udp_hash_lock);
-       return *pos ? udp_get_idx(seq, *pos-1) : (void *)1;
+       return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
 }
 
 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
        struct sock *sk;
 
-       if (v == (void *)1)
+       if (v == SEQ_START_TOKEN)
                sk = udp_get_idx(seq, 0);
        else
                sk = udp_get_next(seq, v);
@@ -1662,70 +1654,59 @@ static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 
 static void udp_seq_stop(struct seq_file *seq, void *v)
 {
-       read_unlock(&udp_hash_lock);
+       struct udp_iter_state *state = seq->private;
+
+       if (state->bucket < UDP_HTABLE_SIZE)
+               spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
 }
 
 static int udp_seq_open(struct inode *inode, struct file *file)
 {
        struct udp_seq_afinfo *afinfo = PDE(inode)->data;
-       struct seq_file *seq;
-       int rc = -ENOMEM;
-       struct udp_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
+       struct udp_iter_state *s;
+       int err;
 
-       if (!s)
-               goto out;
+       err = seq_open_net(inode, file, &afinfo->seq_ops,
+                          sizeof(struct udp_iter_state));
+       if (err < 0)
+               return err;
+
+       s = ((struct seq_file *)file->private_data)->private;
        s->family               = afinfo->family;
-       s->hashtable            = afinfo->hashtable;
-       s->seq_ops.start        = udp_seq_start;
-       s->seq_ops.next         = udp_seq_next;
-       s->seq_ops.show         = afinfo->seq_show;
-       s->seq_ops.stop         = udp_seq_stop;
-
-       rc = seq_open(file, &s->seq_ops);
-       if (rc)
-               goto out_kfree;
-
-       seq          = file->private_data;
-       seq->private = s;
-out:
-       return rc;
-out_kfree:
-       kfree(s);
-       goto out;
+       s->udp_table            = afinfo->udp_table;
+       return err;
 }
 
 /* ------------------------------------------------------------------------ */
-int udp_proc_register(struct udp_seq_afinfo *afinfo)
+int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
 {
        struct proc_dir_entry *p;
        int rc = 0;
 
-       if (!afinfo)
-               return -EINVAL;
-       afinfo->seq_fops->owner         = afinfo->owner;
-       afinfo->seq_fops->open          = udp_seq_open;
-       afinfo->seq_fops->read          = seq_read;
-       afinfo->seq_fops->llseek        = seq_lseek;
-       afinfo->seq_fops->release       = seq_release_private;
-
-       p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops);
-       if (p)
-               p->data = afinfo;
-       else
+       afinfo->seq_fops.open           = udp_seq_open;
+       afinfo->seq_fops.read           = seq_read;
+       afinfo->seq_fops.llseek         = seq_lseek;
+       afinfo->seq_fops.release        = seq_release_net;
+
+       afinfo->seq_ops.start           = udp_seq_start;
+       afinfo->seq_ops.next            = udp_seq_next;
+       afinfo->seq_ops.stop            = udp_seq_stop;
+
+       p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
+                            &afinfo->seq_fops, afinfo);
+       if (!p)
                rc = -ENOMEM;
        return rc;
 }
 
-void udp_proc_unregister(struct udp_seq_afinfo *afinfo)
+void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
 {
-       if (!afinfo)
-               return;
-       proc_net_remove(afinfo->name);
-       memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
+       proc_net_remove(net, afinfo->name);
 }
 
 /* ------------------------------------------------------------------------ */
-static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
+static void udp4_format_sock(struct sock *sp, struct seq_file *f,
+               int bucket, int *len)
 {
        struct inet_sock *inet = inet_sk(sp);
        __be32 dest = inet->daddr;
@@ -1733,13 +1714,14 @@ static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
        __u16 destp       = ntohs(inet->dport);
        __u16 srcp        = ntohs(inet->sport);
 
-       sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
-               " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
+       seq_printf(f, "%4d: %08X:%04X %08X:%04X"
+               " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
                bucket, src, srcp, dest, destp, sp->sk_state,
                atomic_read(&sp->sk_wmem_alloc),
                atomic_read(&sp->sk_rmem_alloc),
                0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
-               atomic_read(&sp->sk_refcnt), sp);
+               atomic_read(&sp->sk_refcnt), sp,
+               atomic_read(&sp->sk_drops), len);
 }
 
 int udp4_seq_show(struct seq_file *seq, void *v)
@@ -1748,49 +1730,95 @@ int udp4_seq_show(struct seq_file *seq, void *v)
                seq_printf(seq, "%-127s\n",
                           "  sl  local_address rem_address   st tx_queue "
                           "rx_queue tr tm->when retrnsmt   uid  timeout "
-                          "inode");
+                          "inode ref pointer drops");
        else {
-               char tmpbuf[129];
                struct udp_iter_state *state = seq->private;
+               int len;
 
-               udp4_format_sock(v, tmpbuf, state->bucket);
-               seq_printf(seq, "%-127s\n", tmpbuf);
+               udp4_format_sock(v, seq, state->bucket, &len);
+               seq_printf(seq, "%*s\n", 127 - len ,"");
        }
        return 0;
 }
 
 /* ------------------------------------------------------------------------ */
-static struct file_operations udp4_seq_fops;
 static struct udp_seq_afinfo udp4_seq_afinfo = {
-       .owner          = THIS_MODULE,
        .name           = "udp",
        .family         = AF_INET,
-       .hashtable      = udp_hash,
-       .seq_show       = udp4_seq_show,
-       .seq_fops       = &udp4_seq_fops,
+       .udp_table      = &udp_table,
+       .seq_fops       = {
+               .owner  =       THIS_MODULE,
+       },
+       .seq_ops        = {
+               .show           = udp4_seq_show,
+       },
+};
+
+static int udp4_proc_init_net(struct net *net)
+{
+       return udp_proc_register(net, &udp4_seq_afinfo);
+}
+
+static void udp4_proc_exit_net(struct net *net)
+{
+       udp_proc_unregister(net, &udp4_seq_afinfo);
+}
+
+static struct pernet_operations udp4_net_ops = {
+       .init = udp4_proc_init_net,
+       .exit = udp4_proc_exit_net,
 };
 
 int __init udp4_proc_init(void)
 {
-       return udp_proc_register(&udp4_seq_afinfo);
+       return register_pernet_subsys(&udp4_net_ops);
 }
 
 void udp4_proc_exit(void)
 {
-       udp_proc_unregister(&udp4_seq_afinfo);
+       unregister_pernet_subsys(&udp4_net_ops);
 }
 #endif /* CONFIG_PROC_FS */
 
+void __init udp_table_init(struct udp_table *table)
+{
+       int i;
+
+       for (i = 0; i < UDP_HTABLE_SIZE; i++) {
+               INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
+               spin_lock_init(&table->hash[i].lock);
+       }
+}
+
+void __init udp_init(void)
+{
+       unsigned long nr_pages, limit;
+
+       udp_table_init(&udp_table);
+       /* Set the pressure threshold up by the same strategy of TCP. It is a
+        * fraction of global memory that is up to 1/2 at 256 MB, decreasing
+        * toward zero with the amount of memory, with a floor of 128 pages.
+        */
+       nr_pages = totalram_pages - totalhigh_pages;
+       limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
+       limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
+       limit = max(limit, 128UL);
+       sysctl_udp_mem[0] = limit / 4 * 3;
+       sysctl_udp_mem[1] = limit;
+       sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
+
+       sysctl_udp_rmem_min = SK_MEM_QUANTUM;
+       sysctl_udp_wmem_min = SK_MEM_QUANTUM;
+}
+
 EXPORT_SYMBOL(udp_disconnect);
-EXPORT_SYMBOL(udp_hash);
-EXPORT_SYMBOL(udp_hash_lock);
 EXPORT_SYMBOL(udp_ioctl);
-EXPORT_SYMBOL(udp_get_port);
 EXPORT_SYMBOL(udp_prot);
 EXPORT_SYMBOL(udp_sendmsg);
 EXPORT_SYMBOL(udp_lib_getsockopt);
 EXPORT_SYMBOL(udp_lib_setsockopt);
 EXPORT_SYMBOL(udp_poll);
+EXPORT_SYMBOL(udp_lib_get_port);
 
 #ifdef CONFIG_PROC_FS
 EXPORT_SYMBOL(udp_proc_register);