tcp: accept socket after TCP_DEFER_ACCEPT period
[safe/jmp/linux-2.6] / net / ipv4 / udp.c
index 383d173..d0d436d 100644 (file)
@@ -8,7 +8,7 @@
  * 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:
@@ -81,6 +81,8 @@
 #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 <net/xfrm.h>
 #include "udp_impl.h"
 
-/*
- *     Snmp MIB for the UDP layer
- */
-
-DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;
-EXPORT_SYMBOL(udp_stats_in6);
-
-struct hlist_head udp_hash[UDP_HTABLE_SIZE];
-DEFINE_RWLOCK(udp_hash_lock);
+struct udp_table udp_table;
+EXPORT_SYMBOL(udp_table);
 
 int sysctl_udp_mem[3] __read_mostly;
-int sysctl_udp_rmem_min __read_mostly;
-int sysctl_udp_wmem_min __read_mostly;
-
 EXPORT_SYMBOL(sysctl_udp_mem);
+
+int sysctl_udp_rmem_min __read_mostly;
 EXPORT_SYMBOL(sysctl_udp_rmem_min);
+
+int sysctl_udp_wmem_min __read_mostly;
 EXPORT_SYMBOL(sysctl_udp_wmem_min);
 
 atomic_t udp_memory_allocated;
 EXPORT_SYMBOL(udp_memory_allocated);
 
-static inline int __udp_lib_lport_inuse(struct net *net, __u16 num,
-                                       const struct hlist_head udptable[])
-{
-       struct sock *sk;
-       struct hlist_node *node;
+#define PORTS_PER_CHAIN (65536 / UDP_HTABLE_SIZE)
 
-       sk_for_each(sk, node, &udptable[udp_hashfn(net, num)])
-               if (net_eq(sock_net(sk), net) && sk->sk_hash == num)
-                       return 1;
+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 *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;
 }
 
@@ -146,101 +159,78 @@ static inline int __udp_lib_lport_inuse(struct net *net, __u16 num,
  */
 int udp_lib_get_port(struct sock *sk, unsigned short snum,
                       int (*saddr_comp)(const struct sock *sk1,
-                                        const struct sock *sk2 )    )
+                                        const struct sock *sk2))
 {
-       struct hlist_head *udptable = sk->sk_prot->h.udp_hash;
-       struct hlist_node *node;
-       struct hlist_head *head;
-       struct sock *sk2;
+       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) {
-               int i, low, high, remaining;
-               unsigned rover, best, best_size_so_far;
+               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;
 
-               best_size_so_far = UINT_MAX;
-               best = rover = net_random() % remaining + low;
-
-               /* 1st pass: look for empty (or shortest) hash chain */
-               for (i = 0; i < UDP_HTABLE_SIZE; i++) {
-                       int size = 0;
-
-                       head = &udptable[udp_hashfn(net, rover)];
-                       if (hlist_empty(head))
-                               goto gotit;
-
-                       sk_for_each(sk2, node, head) {
-                               if (++size >= best_size_so_far)
-                                       goto next;
-                       }
-                       best_size_so_far = size;
-                       best = rover;
-               next:
-                       /* fold back if end of range */
-                       if (++rover > high)
-                               rover = low + ((rover - low)
-                                              & (UDP_HTABLE_SIZE - 1));
-
-
-               }
-
-               /* 2nd pass: find hole in shortest hash chain */
-               rover = best;
-               for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++) {
-                       if (! __udp_lib_lport_inuse(net, rover, udptable))
-                               goto gotit;
-                       rover += UDP_HTABLE_SIZE;
-                       if (rover > high)
-                               rover = low + ((rover - low)
-                                              & (UDP_HTABLE_SIZE - 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);
                }
-
-
-               /* All ports in use! */
                goto fail;
-
-gotit:
-               snum = rover;
        } else {
-               head = &udptable[udp_hashfn(net, snum)];
-
-               sk_for_each(sk2, node, head)
-                       if (sk2->sk_hash == snum                             &&
-                           sk2 != sk                                        &&
-                           net_eq(sock_net(sk2), net)                       &&
-                           (!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 = snum;
        if (sk_unhashed(sk)) {
-               head = &udptable[udp_hashfn(net, snum)];
-               sk_add_node(sk, head);
+               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;
 }
+EXPORT_SYMBOL(udp_lib_get_port);
 
 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);
 
-       return  ( !ipv6_only_sock(sk2)  &&
-                 (!inet1->rcv_saddr || !inet2->rcv_saddr ||
-                  inet1->rcv_saddr == inet2->rcv_saddr      ));
+       return  (!ipv6_only_sock(sk2)  &&
+                (!inet1->rcv_saddr || !inet2->rcv_saddr ||
+                  inet1->rcv_saddr == inet2->rcv_saddr));
 }
 
 int udp_v4_get_port(struct sock *sk, unsigned short snum)
@@ -248,73 +238,124 @@ int udp_v4_get_port(struct sock *sk, unsigned short snum)
        return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
 }
 
+static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
+                        unsigned short hnum,
+                        __be16 sport, __be32 daddr, __be16 dport, int dif)
+{
+       int score = -1;
+
+       if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
+                       !ipv6_only_sock(sk)) {
+               struct inet_sock *inet = inet_sk(sk);
+
+               score = (sk->sk_family == PF_INET ? 1 : 0);
+               if (inet->rcv_saddr) {
+                       if (inet->rcv_saddr != daddr)
+                               return -1;
+                       score += 2;
+               }
+               if (inet->daddr) {
+                       if (inet->daddr != saddr)
+                               return -1;
+                       score += 2;
+               }
+               if (inet->dport) {
+                       if (inet->dport != sport)
+                               return -1;
+                       score += 2;
+               }
+               if (sk->sk_bound_dev_if) {
+                       if (sk->sk_bound_dev_if != dif)
+                               return -1;
+                       score += 2;
+               }
+       }
+       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 hlist_head udptable[])
+               int dif, struct udp_table *udptable)
 {
-       struct sock *sk, *result = NULL;
-       struct hlist_node *node;
+       struct sock *sk, *result;
+       struct hlist_nulls_node *node;
        unsigned short hnum = ntohs(dport);
-       int badness = -1;
-
-       read_lock(&udp_hash_lock);
-       sk_for_each(sk, node, &udptable[udp_hashfn(net, hnum)]) {
-               struct inet_sock *inet = inet_sk(sk);
-
-               if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
-                               !ipv6_only_sock(sk)) {
-                       int score = (sk->sk_family == PF_INET ? 1 : 0);
-                       if (inet->rcv_saddr) {
-                               if (inet->rcv_saddr != daddr)
-                                       continue;
-                               score+=2;
-                       }
-                       if (inet->daddr) {
-                               if (inet->daddr != saddr)
-                                       continue;
-                               score+=2;
-                       }
-                       if (inet->dport) {
-                               if (inet->dport != sport)
-                                       continue;
-                               score+=2;
-                       }
-                       if (sk->sk_bound_dev_if) {
-                               if (sk->sk_bound_dev_if != dif)
-                                       continue;
-                               score+=2;
-                       }
-                       if (score == 9) {
-                               result = sk;
-                               break;
-                       } else if (score > badness) {
-                               result = sk;
-                               badness = score;
-                       }
+       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;
+                       badness = score;
                }
        }
-       if (result)
-               sock_hold(result);
-       read_unlock(&udp_hash_lock);
+       /*
+        * 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;
+               }
+       }
+       rcu_read_unlock();
        return result;
 }
 
-static inline struct sock *udp_v4_mcast_next(struct sock *sk,
+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(skb)->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                                  ||
+               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)    ||
@@ -341,11 +382,11 @@ 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;
-       struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
+       struct iphdr *iph = (struct iphdr *)skb->data;
+       struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
        const int type = icmp_hdr(skb)->type;
        const int code = icmp_hdr(skb)->code;
        struct sock *sk;
@@ -400,7 +441,7 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
                if (!harderr || sk->sk_state != TCP_ESTABLISHED)
                        goto out;
        } else {
-               ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
+               ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
        }
        sk->sk_err = err;
        sk->sk_error_report(sk);
@@ -410,7 +451,7 @@ out:
 
 void udp_err(struct sk_buff *skb, u32 info)
 {
-       __udp4_lib_err(skb, info, udp_hash);
+       __udp4_lib_err(skb, info, &udp_table);
 }
 
 /*
@@ -435,7 +476,7 @@ EXPORT_SYMBOL(udp_flush_pending_frames);
  *             (checksum field must be zeroed out)
  */
 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
-                                __be32 src, __be32 dst, int len      )
+                                __be32 src, __be32 dst, int len)
 {
        unsigned int offset;
        struct udphdr *uh = udp_hdr(skb);
@@ -506,7 +547,7 @@ static int udp_push_pending_frames(struct sock *sk)
 
        } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
 
-               udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
+               udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len);
                goto send;
 
        } else                                           /*   `normal' UDP    */
@@ -514,18 +555,24 @@ static int udp_push_pending_frames(struct sock *sk)
 
        /* add protocol-dependent pseudo-header */
        uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
-                                     sk->sk_protocol, csum             );
+                                     sk->sk_protocol, csum);
        if (uh->check == 0)
                uh->check = CSUM_MANGLED_0;
 
 send:
        err = ip_push_pending_frames(sk);
+       if (err) {
+               if (err == -ENOBUFS && !inet->recverr) {
+                       UDP_INC_STATS_USER(sock_net(sk),
+                                          UDP_MIB_SNDBUFERRORS, is_udplite);
+                       err = 0;
+               }
+       } else
+               UDP_INC_STATS_USER(sock_net(sk),
+                                  UDP_MIB_OUTDATAGRAMS, is_udplite);
 out:
        up->len = 0;
        up->pending = 0;
-       if (!err)
-               UDP_INC_STATS_USER(sock_net(sk),
-                               UDP_MIB_OUTDATAGRAMS, is_udplite);
        return err;
 }
 
@@ -553,10 +600,11 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
         *      Check the flags.
         */
 
-       if (msg->msg_flags&MSG_OOB)     /* Mirror BSD error message compatibility */
+       if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
                return -EOPNOTSUPP;
 
        ipc.opt = NULL;
+       ipc.shtx.flags = 0;
 
        if (up->pending) {
                /*
@@ -579,7 +627,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
         *      Get and verify the address.
         */
        if (msg->msg_name) {
-               struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
+               struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
                if (msg->msg_namelen < sizeof(*usin))
                        return -EINVAL;
                if (usin->sin_family != AF_INET) {
@@ -604,6 +652,9 @@ 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(sock_net(sk), msg, &ipc);
                if (err)
@@ -641,15 +692,17 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
        }
 
        if (connected)
-               rt = (struct rtable*)sk_dst_check(sk, 0);
+               rt = (struct rtable *)sk_dst_check(sk, 0);
 
        if (rt == NULL) {
                struct flowi fl = { .oif = ipc.oif,
+                                   .mark = sk->sk_mark,
                                    .nl_u = { .ip4_u =
                                              { .daddr = faddr,
                                                .saddr = saddr,
                                                .tos = tos } },
                                    .proto = sk->sk_protocol,
+                                   .flags = inet_sk_flowi_flags(sk),
                                    .uli_u = { .ports =
                                               { .sport = inet->sport,
                                                 .dport = dport } } };
@@ -702,7 +755,7 @@ 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);
@@ -738,6 +791,7 @@ do_confirm:
        err = 0;
        goto out;
 }
+EXPORT_SYMBOL(udp_sendmsg);
 
 int udp_sendpage(struct sock *sk, struct page *page, int offset,
                 size_t size, int flags)
@@ -787,6 +841,42 @@ out:
        return ret;
 }
 
+
+/**
+ *     first_packet_length     - return length of first packet in receive queue
+ *     @sk: socket
+ *
+ *     Drops all bad checksum frames, until a valid one is found.
+ *     Returns the length of found skb, or 0 if none is found.
+ */
+static unsigned int first_packet_length(struct sock *sk)
+{
+       struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
+       struct sk_buff *skb;
+       unsigned int res;
+
+       __skb_queue_head_init(&list_kill);
+
+       spin_lock_bh(&rcvq->lock);
+       while ((skb = skb_peek(rcvq)) != NULL &&
+               udp_lib_checksum_complete(skb)) {
+               UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
+                                IS_UDPLITE(sk));
+               __skb_unlink(skb, rcvq);
+               __skb_queue_tail(&list_kill, skb);
+       }
+       res = skb ? skb->len : 0;
+       spin_unlock_bh(&rcvq->lock);
+
+       if (!skb_queue_empty(&list_kill)) {
+               lock_sock(sk);
+               __skb_queue_purge(&list_kill);
+               sk_mem_reclaim_partial(sk);
+               release_sock(sk);
+       }
+       return res;
+}
+
 /*
  *     IOCTL requests applicable to the UDP protocol
  */
@@ -796,27 +886,23 @@ int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
        switch (cmd) {
        case SIOCOUTQ:
        {
-               int amount = atomic_read(&sk->sk_wmem_alloc);
+               int amount = sk_wmem_alloc_get(sk);
+
                return put_user(amount, (int __user *)arg);
        }
 
        case SIOCINQ:
        {
-               struct sk_buff *skb;
-               unsigned long amount;
+               unsigned int amount = first_packet_length(sk);
 
-               amount = 0;
-               spin_lock_bh(&sk->sk_receive_queue.lock);
-               skb = skb_peek(&sk->sk_receive_queue);
-               if (skb != NULL) {
+               if (amount)
                        /*
                         * We will only return the amount
                         * of this packet since that is all
                         * that will be read.
                         */
-                       amount = skb->len - sizeof(struct udphdr);
-               }
-               spin_unlock_bh(&sk->sk_receive_queue.lock);
+                       amount -= sizeof(struct udphdr);
+
                return put_user(amount, (int __user *)arg);
        }
 
@@ -826,6 +912,7 @@ int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 
        return 0;
 }
+EXPORT_SYMBOL(udp_ioctl);
 
 /*
  *     This should be easy, if there is something there we
@@ -847,7 +934,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
         *      Check any passed addresses
         */
        if (addr_len)
-               *addr_len=sizeof(*sin);
+               *addr_len = sizeof(*sin);
 
        if (flags & MSG_ERRQUEUE)
                return ip_recv_error(sk, msg, len);
@@ -878,9 +965,11 @@ try_again:
 
        if (skb_csum_unnecessary(skb))
                err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
-                                             msg->msg_iov, copied       );
+                                             msg->msg_iov, copied);
        else {
-               err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
+               err = skb_copy_and_csum_datagram_iovec(skb,
+                                                      sizeof(struct udphdr),
+                                                      msg->msg_iov);
 
                if (err == -EINVAL)
                        goto csum_copy_err;
@@ -896,8 +985,7 @@ try_again:
        sock_recv_timestamp(msg, sk, skb);
 
        /* Copy the address. */
-       if (sin)
-       {
+       if (sin) {
                sin->sin_family = AF_INET;
                sin->sin_port = udp_hdr(skb)->source;
                sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
@@ -950,6 +1038,47 @@ int udp_disconnect(struct sock *sk, int flags)
        sk_dst_reset(sk);
        return 0;
 }
+EXPORT_SYMBOL(udp_disconnect);
+
+void udp_lib_unhash(struct sock *sk)
+{
+       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);
+
+static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+       int is_udplite = IS_UDPLITE(sk);
+       int rc;
+
+       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;
+       }
+
+       return 0;
+
+drop:
+       UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+       kfree_skb(skb);
+       return -1;
+}
 
 /* returns:
  *  -1: error
@@ -959,7 +1088,7 @@ int udp_disconnect(struct sock *sk, int flags)
  * Note that in the success and error cases, the skb is assumed to
  * have either been requeued or freed.
  */
-int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
+int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
        struct udp_sock *up = udp_sk(sk);
        int rc;
@@ -1042,17 +1171,16 @@ 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(sock_net(sk),
-                                       UDP_MIB_RCVBUFERRORS, is_udplite);
-                       atomic_inc(&sk->sk_drops);
-               }
-               goto drop;
-       }
+       rc = 0;
 
-       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(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
@@ -1069,36 +1197,30 @@ drop:
 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;
+       struct udp_hslot *hslot = &udptable->hash[udp_hashfn(net, ntohs(uh->dest))];
        int dif;
 
-       read_lock(&udp_hash_lock);
-       sk = sk_head(&udptable[udp_hashfn(net, ntohs(uh->dest))]);
+       spin_lock(&hslot->lock);
+       sk = sk_nulls_head(&hslot->head);
        dif = skb->dev->ifindex;
-       sk = udp_v4_mcast_next(sk, uh->dest, 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), uh->dest, 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 = 0;
-
-                               bh_lock_sock_nested(sk);
-                               if (!sock_owned_by_user(sk))
-                                       ret = udp_queue_rcv_skb(sk, skb1);
-                               else
-                                       sk_add_backlog(sk, skb1);
-                               bh_unlock_sock(sk);
-
+                               int ret = udp_queue_rcv_skb(sk, skb1);
                                if (ret > 0)
                                        /* we should probably re-process instead
                                         * of dropping packets here. */
@@ -1107,8 +1229,8 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
                        sk = sknext;
                } while (sknext);
        } else
-               kfree_skb(skb);
-       read_unlock(&udp_hash_lock);
+               consume_skb(skb);
+       spin_unlock(&hslot->lock);
        return 0;
 }
 
@@ -1136,7 +1258,7 @@ static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
        if (uh->check == 0) {
                skb->ip_summed = CHECKSUM_UNNECESSARY;
        } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
-              if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
+               if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
                                      proto, skb->csum))
                        skb->ip_summed = CHECKSUM_UNNECESSARY;
        }
@@ -1154,15 +1276,14 @@ 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;
+       struct rtable *rt = skb_rtable(skb);
+       __be32 saddr, daddr;
        struct net *net = dev_net(skb->dev);
 
        /*
@@ -1171,6 +1292,7 @@ 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;
@@ -1185,21 +1307,17 @@ 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(net, skb, uh,
                                saddr, daddr, udptable);
 
-       sk = __udp4_lib_lookup(net, saddr, uh->source, daddr,
-                       uh->dest, inet_iif(skb), udptable);
+       sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 
        if (sk != NULL) {
-               int ret = 0;
-               bh_lock_sock_nested(sk);
-               if (!sock_owned_by_user(sk))
-                       ret = udp_queue_rcv_skb(sk, skb);
-               else
-                       sk_add_backlog(sk, skb);
-               bh_unlock_sock(sk);
+               int ret = udp_queue_rcv_skb(sk, skb);
                sock_put(sk);
 
                /* a return value > 0 means to resubmit the input, but
@@ -1229,13 +1347,13 @@ 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 " NIPQUAD_FMT ":%u %d/%d to " NIPQUAD_FMT ":%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;
 
@@ -1244,11 +1362,11 @@ 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 " NIPQUAD_FMT ":%u to " NIPQUAD_FMT ":%u 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:
@@ -1259,7 +1377,7 @@ drop:
 
 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);
 }
 
 void udp_destroy_sock(struct sock *sk)
@@ -1273,7 +1391,7 @@ void udp_destroy_sock(struct sock *sk)
  *     Socket option code for UDP
  */
 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
-                      char __user *optval, int optlen,
+                      char __user *optval, unsigned int optlen,
                       int (*push_pending_frames)(struct sock *))
 {
        struct udp_sock *up = udp_sk(sk);
@@ -1281,7 +1399,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
        int err = 0;
        int is_udplite = IS_UDPLITE(sk);
 
-       if (optlen<sizeof(int))
+       if (optlen < sizeof(int))
                return -EINVAL;
 
        if (get_user(val, (int __user *)optval))
@@ -1352,9 +1470,10 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 
        return err;
 }
+EXPORT_SYMBOL(udp_lib_setsockopt);
 
 int udp_setsockopt(struct sock *sk, int level, int optname,
-                  char __user *optval, int optlen)
+                  char __user *optval, unsigned int optlen)
 {
        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
@@ -1364,7 +1483,7 @@ int udp_setsockopt(struct sock *sk, int level, int optname,
 
 #ifdef CONFIG_COMPAT
 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
-                         char __user *optval, int optlen)
+                         char __user *optval, unsigned int optlen)
 {
        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
@@ -1379,7 +1498,7 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname,
        struct udp_sock *up = udp_sk(sk);
        int val, len;
 
-       if (get_user(len,optlen))
+       if (get_user(len, optlen))
                return -EFAULT;
 
        len = min_t(unsigned int, len, sizeof(int));
@@ -1412,10 +1531,11 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname,
 
        if (put_user(len, optlen))
                return -EFAULT;
-       if (copy_to_user(optval, &val,len))
+       if (copy_to_user(optval, &val, len))
                return -EFAULT;
        return 0;
 }
+EXPORT_SYMBOL(udp_lib_getsockopt);
 
 int udp_getsockopt(struct sock *sk, int level, int optname,
                   char __user *optval, int __user *optlen)
@@ -1451,33 +1571,16 @@ unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
 {
        unsigned int mask = datagram_poll(file, sock, wait);
        struct sock *sk = sock->sk;
-       int     is_lite = IS_UDPLITE(sk);
 
        /* Check for false positives due to checksum errors */
-       if ( (mask & POLLRDNORM) &&
-            !(file->f_flags & O_NONBLOCK) &&
-            !(sk->sk_shutdown & RCV_SHUTDOWN)){
-               struct sk_buff_head *rcvq = &sk->sk_receive_queue;
-               struct sk_buff *skb;
-
-               spin_lock_bh(&rcvq->lock);
-               while ((skb = skb_peek(rcvq)) != NULL &&
-                      udp_lib_checksum_complete(skb)) {
-                       UDP_INC_STATS_BH(sock_net(sk),
-                                       UDP_MIB_INERRORS, is_lite);
-                       __skb_unlink(skb, rcvq);
-                       kfree_skb(skb);
-               }
-               spin_unlock_bh(&rcvq->lock);
-
-               /* nothing to see, move along */
-               if (skb == NULL)
-                       mask &= ~(POLLIN | POLLRDNORM);
-       }
+       if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
+           !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
+               mask &= ~(POLLIN | POLLRDNORM);
 
        return mask;
 
 }
+EXPORT_SYMBOL(udp_poll);
 
 struct proto udp_prot = {
        .name              = "UDP",
@@ -1492,7 +1595,7 @@ 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,
@@ -1501,30 +1604,35 @@ struct proto udp_prot = {
        .sysctl_wmem       = &sysctl_udp_wmem_min,
        .sysctl_rmem       = &sysctl_udp_rmem_min,
        .obj_size          = sizeof(struct udp_sock),
-       .h.udp_hash        = udp_hash,
+       .slab_flags        = SLAB_DESTROY_BY_RCU,
+       .h.udp_table       = &udp_table,
 #ifdef CONFIG_COMPAT
        .compat_setsockopt = compat_udp_setsockopt,
        .compat_getsockopt = compat_udp_getsockopt,
 #endif
 };
+EXPORT_SYMBOL(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;
        struct net *net = seq_file_net(seq);
 
-       for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
-               struct hlist_node *node;
-               sk_for_each(sk, node, state->hashtable + state->bucket) {
+       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:
@@ -1537,21 +1645,20 @@ static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
        struct net *net = seq_file_net(seq);
 
        do {
-               sk = sk_next(sk);
-try_again:
-               ;
+               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) {
+               if (state->bucket < UDP_HTABLE_SIZE)
+                       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)
@@ -1560,9 +1667,10 @@ 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)
-       __acquires(udp_hash_lock)
 {
-       read_lock(&udp_hash_lock);
+       struct udp_iter_state *state = seq->private;
+       state->bucket = UDP_HTABLE_SIZE;
+
        return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
 }
 
@@ -1580,9 +1688,11 @@ 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)
-       __releases(udp_hash_lock)
 {
-       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)
@@ -1598,7 +1708,7 @@ static int udp_seq_open(struct inode *inode, struct file *file)
 
        s = ((struct seq_file *)file->private_data)->private;
        s->family               = afinfo->family;
-       s->hashtable            = afinfo->hashtable;
+       s->udp_table            = afinfo->udp_table;
        return err;
 }
 
@@ -1623,11 +1733,13 @@ int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
                rc = -ENOMEM;
        return rc;
 }
+EXPORT_SYMBOL(udp_proc_register);
 
 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
 {
        proc_net_remove(net, afinfo->name);
 }
+EXPORT_SYMBOL(udp_proc_unregister);
 
 /* ------------------------------------------------------------------------ */
 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
@@ -1642,8 +1754,8 @@ static void udp4_format_sock(struct sock *sp, struct seq_file *f,
        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),
+               sk_wmem_alloc_get(sp),
+               sk_rmem_alloc_get(sp),
                0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
                atomic_read(&sp->sk_refcnt), sp,
                atomic_read(&sp->sk_drops), len);
@@ -1661,7 +1773,7 @@ int udp4_seq_show(struct seq_file *seq, void *v)
                int len;
 
                udp4_format_sock(v, seq, state->bucket, &len);
-               seq_printf(seq, "%*s\n", 127 - len ,"");
+               seq_printf(seq, "%*s\n", 127 - len"");
        }
        return 0;
 }
@@ -1670,7 +1782,7 @@ int udp4_seq_show(struct seq_file *seq, void *v)
 static struct udp_seq_afinfo udp4_seq_afinfo = {
        .name           = "udp",
        .family         = AF_INET,
-       .hashtable      = udp_hash,
+       .udp_table      = &udp_table,
        .seq_fops       = {
                .owner  =       THIS_MODULE,
        },
@@ -1705,16 +1817,28 @@ void udp4_proc_exit(void)
 }
 #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 limit;
+       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.
         */
-       limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
-       limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
+       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;
@@ -1724,18 +1848,64 @@ void __init udp_init(void)
        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_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);
+int udp4_ufo_send_check(struct sk_buff *skb)
+{
+       const struct iphdr *iph;
+       struct udphdr *uh;
+
+       if (!pskb_may_pull(skb, sizeof(*uh)))
+               return -EINVAL;
+
+       iph = ip_hdr(skb);
+       uh = udp_hdr(skb);
+
+       uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
+                                      IPPROTO_UDP, 0);
+       skb->csum_start = skb_transport_header(skb) - skb->head;
+       skb->csum_offset = offsetof(struct udphdr, check);
+       skb->ip_summed = CHECKSUM_PARTIAL;
+       return 0;
+}
+
+struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
+{
+       struct sk_buff *segs = ERR_PTR(-EINVAL);
+       unsigned int mss;
+       int offset;
+       __wsum csum;
+
+       mss = skb_shinfo(skb)->gso_size;
+       if (unlikely(skb->len <= mss))
+               goto out;
+
+       if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
+               /* Packet is from an untrusted source, reset gso_segs. */
+               int type = skb_shinfo(skb)->gso_type;
+
+               if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
+                            !(type & (SKB_GSO_UDP))))
+                       goto out;
+
+               skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
+
+               segs = NULL;
+               goto out;
+       }
+
+       /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
+        * do checksum of UDP packets sent as multiple IP fragments.
+        */
+       offset = skb->csum_start - skb_headroom(skb);
+       csum = skb_checksum(skb, offset, skb->len - offset, 0);
+       offset += skb->csum_offset;
+       *(__sum16 *)(skb->data + offset) = csum_fold(csum);
+       skb->ip_summed = CHECKSUM_NONE;
+
+       /* Fragment the skb. IP headers of the fragments are updated in
+        * inet_gso_segment()
+        */
+       segs = skb_segment(skb, features);
+out:
+       return segs;
+}
 
-#ifdef CONFIG_PROC_FS
-EXPORT_SYMBOL(udp_proc_register);
-EXPORT_SYMBOL(udp_proc_unregister);
-#endif