ClabureDB: Classified Bug-Reports Database

   /*
    * INET                An implementation of the TCP/IP protocol suite for the LINUX
    *                operating system.  INET is implemented using the  BSD Socket
    *                interface as the means of communication with the user level.
    *
    *                Generic socket support routines. Memory allocators, socket lock/release
    *                handler for protocols to use and generic option handler.
    *
    *
   * Authors:        Ross Biro
   *                Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   *                Florian La Roche, <flla@stud.uni-sb.de>
   *                Alan Cox, <A.Cox@swansea.ac.uk>
   *
   * Fixes:
   *                Alan Cox        :         Numerous verify_area() problems
   *                Alan Cox        :        Connecting on a connecting socket
   *                                        now returns an error for tcp.
   *                Alan Cox        :        sock->protocol is set correctly.
   *                                        and is not sometimes left as 0.
   *                Alan Cox        :        connect handles icmp errors on a
   *                                        connect properly. Unfortunately there
   *                                        is a restart syscall nasty there. I
   *                                        can't match BSD without hacking the C
   *                                        library. Ideas urgently sought!
   *                Alan Cox        :        Disallow bind() to addresses that are
   *                                        not ours - especially broadcast ones!!
   *                Alan Cox        :        Socket 1024 _IS_ ok for users. (fencepost)
   *                Alan Cox        :        sock_wfree/sock_rfree don't destroy sockets,
   *                                        instead they leave that for the DESTROY timer.
   *                Alan Cox        :        Clean up error flag in accept
   *                Alan Cox        :        TCP ack handling is buggy, the DESTROY timer
   *                                        was buggy. Put a remove_sock() in the handler
   *                                        for memory when we hit 0. Also altered the timer
   *                                        code. The ACK stuff can wait and needs major
   *                                        TCP layer surgery.
   *                Alan Cox        :        Fixed TCP ack bug, removed remove sock
   *                                        and fixed timer/inet_bh race.
   *                Alan Cox        :        Added zapped flag for TCP
   *                Alan Cox        :        Move kfree_skb into skbuff.c and tidied up surplus code
   *                Alan Cox        :        for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
   *                Alan Cox        :        kfree_s calls now are kfree_skbmem so we can track skb resources
   *                Alan Cox        :        Supports socket option broadcast now as does udp. Packet and raw need fixing.
   *                Alan Cox        :        Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
   *                Rick Sladkey        :        Relaxed UDP rules for matching packets.
   *                C.E.Hawkins        :        IFF_PROMISC/SIOCGHWADDR support
   *        Pauline Middelink        :        identd support
   *                Alan Cox        :        Fixed connect() taking signals I think.
   *                Alan Cox        :        SO_LINGER supported
   *                Alan Cox        :        Error reporting fixes
   *                Anonymous        :        inet_create tidied up (sk->reuse setting)
   *                Alan Cox        :        inet sockets don't set sk->type!
   *                Alan Cox        :        Split socket option code
   *                Alan Cox        :        Callbacks
   *                Alan Cox        :        Nagle flag for Charles & Johannes stuff
   *                Alex                :        Removed restriction on inet fioctl
   *                Alan Cox        :        Splitting INET from NET core
   *                Alan Cox        :        Fixed bogus SO_TYPE handling in getsockopt()
   *                Adam Caldwell        :        Missing return in SO_DONTROUTE/SO_DEBUG code
   *                Alan Cox        :        Split IP from generic code
   *                Alan Cox        :        New kfree_skbmem()
   *                Alan Cox        :        Make SO_DEBUG superuser only.
   *                Alan Cox        :        Allow anyone to clear SO_DEBUG
   *                                        (compatibility fix)
   *                Alan Cox        :        Added optimistic memory grabbing for AF_UNIX throughput.
   *                Alan Cox        :        Allocator for a socket is settable.
   *                Alan Cox        :        SO_ERROR includes soft errors.
   *                Alan Cox        :        Allow NULL arguments on some SO_ opts
   *                Alan Cox        :         Generic socket allocation to make hooks
   *                                        easier (suggested by Craig Metz).
   *                Michael Pall        :        SO_ERROR returns positive errno again
   *              Steve Whitehouse:       Added default destructor to free
   *                                      protocol private data.
   *              Steve Whitehouse:       Added various other default routines
   *                                      common to several socket families.
   *              Chris Evans     :       Call suser() check last on F_SETOWN
   *                Jay Schulist        :        Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
   *                Andi Kleen        :        Add sock_kmalloc()/sock_kfree_s()
   *                Andi Kleen        :        Fix write_space callback
   *                Chris Evans        :        Security fixes - signedness again
   *                Arnaldo C. Melo :       cleanups, use skb_queue_purge
   *
   * To Fix:
   *
   *
   *                This program is free software; you can redistribute it and/or
   *                modify it under the terms of the GNU General Public License
   *                as published by the Free Software Foundation; either version
   *                2 of the License, or (at your option) any later version.
   */
  
  #include <linux/capability.h>
  #include <linux/errno.h>
  #include <linux/types.h>
  #include <linux/socket.h>
  #include <linux/in.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/sched.h>
 #include <linux/timer.h>
 #include <linux/string.h>
 #include <linux/sockios.h>
 #include <linux/net.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/poll.h>
 #include <linux/tcp.h>
 #include <linux/init.h>
 #include <linux/highmem.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
 #include <linux/netdevice.h>
 #include <net/protocol.h>
 #include <linux/skbuff.h>
 #include <net/net_namespace.h>
 #include <net/request_sock.h>
 #include <net/sock.h>
 #include <net/xfrm.h>
 #include <linux/ipsec.h>
 
 #include <linux/filter.h>
 
 #ifdef CONFIG_INET
 #include <net/tcp.h>
 #endif
 
 /*
  * Each address family might have different locking rules, so we have
  * one slock key per address family:
  */
 static struct lock_class_key af_family_keys[AF_MAX];
 static struct lock_class_key af_family_slock_keys[AF_MAX];
 
 /*
  * Make lock validator output more readable. (we pre-construct these
  * strings build-time, so that runtime initialization of socket
  * locks is fast):
  */
 static const char *af_family_key_strings[AF_MAX+1] = {
   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
   "sk_lock-21"       , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
   "sk_lock-AF_MAX"
 };
 static const char *af_family_slock_key_strings[AF_MAX+1] = {
   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
   "slock-21"       , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
   "slock-AF_MAX"
 };
 static const char *af_family_clock_key_strings[AF_MAX+1] = {
   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
   "clock-21"       , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
   "clock-AF_MAX"
 };
 
 /*
  * sk_callback_lock locking rules are per-address-family,
  * so split the lock classes by using a per-AF key:
  */
 static struct lock_class_key af_callback_keys[AF_MAX];
 
 /* Take into consideration the size of the struct sk_buff overhead in the
  * determination of these values, since that is non-constant across
  * platforms.  This makes socket queueing behavior and performance
  * not depend upon such differences.
  */
 #define _SK_MEM_PACKETS                256
 #define _SK_MEM_OVERHEAD        (sizeof(struct sk_buff) + 256)
 #define SK_WMEM_MAX                (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
 #define SK_RMEM_MAX                (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
 
 /* Run time adjustable parameters. */
 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
 
 /* Maximal space eaten by iovec or ancilliary data plus some space */
 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
 
 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
 {
         struct timeval tv;
 
         if (optlen < sizeof(tv))
                 return -EINVAL;
         if (copy_from_user(&tv, optval, sizeof(tv)))
                 return -EFAULT;
         if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
                 return -EDOM;
 
         if (tv.tv_sec < 0) {
                 static int warned __read_mostly;
 
                 *timeo_p = 0;
                 if (warned < 10 && net_ratelimit()) {
                         warned++;
                         printk(KERN_INFO "sock_set_timeout: `%s' (pid %d) "
                                "tries to set negative timeout\n",
                                 current->comm, task_pid_nr(current));
                 }
                 return 0;
         }
         *timeo_p = MAX_SCHEDULE_TIMEOUT;
         if (tv.tv_sec == 0 && tv.tv_usec == 0)
                 return 0;
         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
                 *timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
         return 0;
 }
 
 static void sock_warn_obsolete_bsdism(const char *name)
 {
         static int warned;
         static char warncomm[TASK_COMM_LEN];
         if (strcmp(warncomm, current->comm) && warned < 5) {
                 strcpy(warncomm,  current->comm);
                 printk(KERN_WARNING "process `%s' is using obsolete "
                        "%s SO_BSDCOMPAT\n", warncomm, name);
                 warned++;
         }
 }
 
 static void sock_disable_timestamp(struct sock *sk)
 {
         if (sock_flag(sk, SOCK_TIMESTAMP)) {
                 sock_reset_flag(sk, SOCK_TIMESTAMP);
                 net_disable_timestamp();
         }
 }
 
 
 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
         int err = 0;
         int skb_len;
 
         /* Cast sk->rcvbuf to unsigned... It's pointless, but reduces
            number of warnings when compiling with -W --ANK
          */
         if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
             (unsigned)sk->sk_rcvbuf) {
                 err = -ENOMEM;
                 goto out;
         }
 
         err = sk_filter(sk, skb);
         if (err)
                 goto out;
 
         if (!sk_rmem_schedule(sk, skb->truesize)) {
                 err = -ENOBUFS;
                 goto out;
         }
 
         skb->dev = NULL;
         skb_set_owner_r(skb, sk);
 
         /* Cache the SKB length before we tack it onto the receive
          * queue.  Once it is added it no longer belongs to us and
          * may be freed by other threads of control pulling packets
          * from the queue.
          */
         skb_len = skb->len;
 
         skb_queue_tail(&sk->sk_receive_queue, skb);
 
         if (!sock_flag(sk, SOCK_DEAD))
                 sk->sk_data_ready(sk, skb_len);
 out:
         return err;
 }
 EXPORT_SYMBOL(sock_queue_rcv_skb);
 
 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
 {
         int rc = NET_RX_SUCCESS;
 
         if (sk_filter(sk, skb))
                 goto discard_and_relse;
 
         skb->dev = NULL;
 
         if (nested)
                 bh_lock_sock_nested(sk);
         else
                 bh_lock_sock(sk);
         if (!sock_owned_by_user(sk)) {
                 /*
                  * trylock + unlock semantics:
                  */
                 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
 
                 rc = sk_backlog_rcv(sk, skb);
 
                 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
         } else
                 sk_add_backlog(sk, skb);
         bh_unlock_sock(sk);
 out:
         sock_put(sk);
         return rc;
 discard_and_relse:
         kfree_skb(skb);
         goto out;
 }
 EXPORT_SYMBOL(sk_receive_skb);
 
 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
 {
         struct dst_entry *dst = sk->sk_dst_cache;
 
         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
                 sk->sk_dst_cache = NULL;
                 dst_release(dst);
                 return NULL;
         }
 
         return dst;
 }
 EXPORT_SYMBOL(__sk_dst_check);
 
 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
 {
         struct dst_entry *dst = sk_dst_get(sk);
 
         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
                 sk_dst_reset(sk);
                 dst_release(dst);
                 return NULL;
         }
 
         return dst;
 }
 EXPORT_SYMBOL(sk_dst_check);
 
 static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
 {
         int ret = -ENOPROTOOPT;
 #ifdef CONFIG_NETDEVICES
         struct net *net = sock_net(sk);
         char devname[IFNAMSIZ];
         int index;
 
         /* Sorry... */
         ret = -EPERM;
         if (!capable(CAP_NET_RAW))
                 goto out;
 
         ret = -EINVAL;
         if (optlen < 0)
                 goto out;
 
         /* Bind this socket to a particular device like "eth0",
          * as specified in the passed interface name. If the
          * name is "" or the option length is zero the socket
          * is not bound.
          */
         if (optlen > IFNAMSIZ - 1)
                 optlen = IFNAMSIZ - 1;
         memset(devname, 0, sizeof(devname));
 
         ret = -EFAULT;
         if (copy_from_user(devname, optval, optlen))
                 goto out;
 
         if (devname[0] == '\0') {
                 index = 0;
         } else {
                 struct net_device *dev = dev_get_by_name(net, devname);
 
                 ret = -ENODEV;
                 if (!dev)
                         goto out;
 
                 index = dev->ifindex;
                 dev_put(dev);
         }
 
         lock_sock(sk);
         sk->sk_bound_dev_if = index;
         sk_dst_reset(sk);
         release_sock(sk);
 
         ret = 0;
 
 out:
 #endif
 
         return ret;
 }
 
 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
 {
         if (valbool)
                 sock_set_flag(sk, bit);
         else
                 sock_reset_flag(sk, bit);
 }
 
 /*
  *        This is meant for all protocols to use and covers goings on
  *        at the socket level. Everything here is generic.
  */
 
 int sock_setsockopt(struct socket *sock, int level, int optname,
                     char __user *optval, int optlen)
 {
         struct sock *sk=sock->sk;
         int val;
         int valbool;
         struct linger ling;
         int ret = 0;
 
         /*
          *        Options without arguments
          */
 
         if (optname == SO_BINDTODEVICE)
                 return sock_bindtodevice(sk, optval, optlen);
 
         if (optlen < sizeof(int))
                 return -EINVAL;
 
         if (get_user(val, (int __user *)optval))
                 return -EFAULT;
 
         valbool = val?1:0;
 
         lock_sock(sk);
 
         switch(optname) {
         case SO_DEBUG:
                 if (val && !capable(CAP_NET_ADMIN)) {
                         ret = -EACCES;
                 } else
                         sock_valbool_flag(sk, SOCK_DBG, valbool);
                 break;
         case SO_REUSEADDR:
                 sk->sk_reuse = valbool;
                 break;
         case SO_TYPE:
         case SO_ERROR:
                 ret = -ENOPROTOOPT;
                 break;
         case SO_DONTROUTE:
                 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
                 break;
         case SO_BROADCAST:
                 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
                 break;
         case SO_SNDBUF:
                 /* Don't error on this BSD doesn't and if you think
                    about it this is right. Otherwise apps have to
                    play 'guess the biggest size' games. RCVBUF/SNDBUF
                    are treated in BSD as hints */
 
                 if (val > sysctl_wmem_max)
                         val = sysctl_wmem_max;
 set_sndbuf:
                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
                 if ((val * 2) < SOCK_MIN_SNDBUF)
                         sk->sk_sndbuf = SOCK_MIN_SNDBUF;
                 else
                         sk->sk_sndbuf = val * 2;
 
                 /*
                  *        Wake up sending tasks if we
                  *        upped the value.
                  */
                 sk->sk_write_space(sk);
                 break;
 
         case SO_SNDBUFFORCE:
                 if (!capable(CAP_NET_ADMIN)) {
                         ret = -EPERM;
                         break;
                 }
                 goto set_sndbuf;
 
         case SO_RCVBUF:
                 /* Don't error on this BSD doesn't and if you think
                    about it this is right. Otherwise apps have to
                    play 'guess the biggest size' games. RCVBUF/SNDBUF
                    are treated in BSD as hints */
 
                 if (val > sysctl_rmem_max)
                         val = sysctl_rmem_max;
 set_rcvbuf:
                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
                 /*
                  * We double it on the way in to account for
                  * "struct sk_buff" etc. overhead.   Applications
                  * assume that the SO_RCVBUF setting they make will
                  * allow that much actual data to be received on that
                  * socket.
                  *
                  * Applications are unaware that "struct sk_buff" and
                  * other overheads allocate from the receive buffer
                  * during socket buffer allocation.
                  *
                  * And after considering the possible alternatives,
                  * returning the value we actually used in getsockopt
                  * is the most desirable behavior.
                  */
                 if ((val * 2) < SOCK_MIN_RCVBUF)
                         sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
                 else
                         sk->sk_rcvbuf = val * 2;
                 break;
 
         case SO_RCVBUFFORCE:
                 if (!capable(CAP_NET_ADMIN)) {
                         ret = -EPERM;
                         break;
                 }
                 goto set_rcvbuf;
 
         case SO_KEEPALIVE:
 #ifdef CONFIG_INET
                 if (sk->sk_protocol == IPPROTO_TCP)
                         tcp_set_keepalive(sk, valbool);
 #endif
                 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
                 break;
 
         case SO_OOBINLINE:
                 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
                 break;
 
         case SO_NO_CHECK:
                 sk->sk_no_check = valbool;
                 break;
 
         case SO_PRIORITY:
                 if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
                         sk->sk_priority = val;
                 else
                         ret = -EPERM;
                 break;
 
         case SO_LINGER:
                 if (optlen < sizeof(ling)) {
                         ret = -EINVAL;        /* 1003.1g */
                         break;
                 }
                 if (copy_from_user(&ling,optval,sizeof(ling))) {
                         ret = -EFAULT;
                         break;
                 }
                 if (!ling.l_onoff)
                         sock_reset_flag(sk, SOCK_LINGER);
                 else {
 #if (BITS_PER_LONG == 32)
                         if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
                                 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
                         else
 #endif
                                 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
                         sock_set_flag(sk, SOCK_LINGER);
                 }
                 break;
 
         case SO_BSDCOMPAT:
                 sock_warn_obsolete_bsdism("setsockopt");
                 break;
 
         case SO_PASSCRED:
                 if (valbool)
                         set_bit(SOCK_PASSCRED, &sock->flags);
                 else
                         clear_bit(SOCK_PASSCRED, &sock->flags);
                 break;
 
         case SO_TIMESTAMP:
         case SO_TIMESTAMPNS:
                 if (valbool)  {
                         if (optname == SO_TIMESTAMP)
                                 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
                         else
                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
                         sock_set_flag(sk, SOCK_RCVTSTAMP);
                         sock_enable_timestamp(sk);
                 } else {
                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
                 }
                 break;
 
         case SO_RCVLOWAT:
                 if (val < 0)
                         val = INT_MAX;
                 sk->sk_rcvlowat = val ? : 1;
                 break;
 
         case SO_RCVTIMEO:
                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
                 break;
 
         case SO_SNDTIMEO:
                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
                 break;
 
         case SO_ATTACH_FILTER:
                 ret = -EINVAL;
                 if (optlen == sizeof(struct sock_fprog)) {
                         struct sock_fprog fprog;
 
                         ret = -EFAULT;
                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
                                 break;
 
                         ret = sk_attach_filter(&fprog, sk);
                 }
                 break;
 
         case SO_DETACH_FILTER:
                 ret = sk_detach_filter(sk);
                 break;
 
         case SO_PASSSEC:
                 if (valbool)
                         set_bit(SOCK_PASSSEC, &sock->flags);
                 else
                         clear_bit(SOCK_PASSSEC, &sock->flags);
                 break;
         case SO_MARK:
                 if (!capable(CAP_NET_ADMIN))
                         ret = -EPERM;
                 else {
                         sk->sk_mark = val;
                 }
                 break;
 
                 /* We implement the SO_SNDLOWAT etc to
                    not be settable (1003.1g 5.3) */
         default:
                 ret = -ENOPROTOOPT;
                 break;
         }
         release_sock(sk);
         return ret;
 }
 
 
 int sock_getsockopt(struct socket *sock, int level, int optname,
                     char __user *optval, int __user *optlen)
 {
         struct sock *sk = sock->sk;
 
         union {
                 int val;
                 struct linger ling;
                 struct timeval tm;
         } v;
 
         unsigned int lv = sizeof(int);
         int len;
 
         if (get_user(len, optlen))
                 return -EFAULT;
         if (len < 0)
                 return -EINVAL;
 
         switch(optname) {
         case SO_DEBUG:
                 v.val = sock_flag(sk, SOCK_DBG);
                 break;
 
         case SO_DONTROUTE:
                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
                 break;
 
         case SO_BROADCAST:
                 v.val = !!sock_flag(sk, SOCK_BROADCAST);
                 break;
 
         case SO_SNDBUF:
                 v.val = sk->sk_sndbuf;
                 break;
 
         case SO_RCVBUF:
                 v.val = sk->sk_rcvbuf;
                 break;
 
         case SO_REUSEADDR:
                 v.val = sk->sk_reuse;
                 break;
 
         case SO_KEEPALIVE:
                 v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
                 break;
 
         case SO_TYPE:
                 v.val = sk->sk_type;
                 break;
 
         case SO_ERROR:
                 v.val = -sock_error(sk);
                 if (v.val==0)
                         v.val = xchg(&sk->sk_err_soft, 0);
                 break;
 
         case SO_OOBINLINE:
                 v.val = !!sock_flag(sk, SOCK_URGINLINE);
                 break;
 
         case SO_NO_CHECK:
                 v.val = sk->sk_no_check;
                 break;
 
         case SO_PRIORITY:
                 v.val = sk->sk_priority;
                 break;
 
         case SO_LINGER:
                 lv                = sizeof(v.ling);
                 v.ling.l_onoff        = !!sock_flag(sk, SOCK_LINGER);
                 v.ling.l_linger        = sk->sk_lingertime / HZ;
                 break;
 
         case SO_BSDCOMPAT:
                 sock_warn_obsolete_bsdism("getsockopt");
                 break;
 
         case SO_TIMESTAMP:
                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
                 break;
 
         case SO_TIMESTAMPNS:
                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
                 break;
 
         case SO_RCVTIMEO:
                 lv=sizeof(struct timeval);
                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
                         v.tm.tv_sec = 0;
                         v.tm.tv_usec = 0;
                 } else {
                         v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
                         v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
                 }
                 break;
 
         case SO_SNDTIMEO:
                 lv=sizeof(struct timeval);
                 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
                         v.tm.tv_sec = 0;
                         v.tm.tv_usec = 0;
                 } else {
                         v.tm.tv_sec = sk->sk_sndtimeo / HZ;
                         v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
                 }
                 break;
 
         case SO_RCVLOWAT:
                 v.val = sk->sk_rcvlowat;
                 break;
 
         case SO_SNDLOWAT:
                 v.val=1;
                 break;
 
         case SO_PASSCRED:
                 v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
                 break;
 
         case SO_PEERCRED:
                 if (len > sizeof(sk->sk_peercred))
                         len = sizeof(sk->sk_peercred);
                 if (copy_to_user(optval, &sk->sk_peercred, len))
                         return -EFAULT;
                 goto lenout;
 
         case SO_PEERNAME:
         {
                 char address[128];
 
                 if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
                         return -ENOTCONN;
                 if (lv < len)
                         return -EINVAL;
                 if (copy_to_user(optval, address, len))
                         return -EFAULT;
                 goto lenout;
         }
 
         /* Dubious BSD thing... Probably nobody even uses it, but
          * the UNIX standard wants it for whatever reason... -DaveM
          */
         case SO_ACCEPTCONN:
                 v.val = sk->sk_state == TCP_LISTEN;
                 break;
 
         case SO_PASSSEC:
                 v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
                 break;
 
         case SO_PEERSEC:
                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
 
         case SO_MARK:
                 v.val = sk->sk_mark;
                 break;
 
         default:
                 return -ENOPROTOOPT;
         }
 
         if (len > lv)
                 len = lv;
         if (copy_to_user(optval, &v, len))
                 return -EFAULT;
 lenout:
         if (put_user(len, optlen))
                 return -EFAULT;
         return 0;
 }
 
 /*
  * Initialize an sk_lock.
  *
  * (We also register the sk_lock with the lock validator.)
  */
 static inline void sock_lock_init(struct sock *sk)
 {
         sock_lock_init_class_and_name(sk,
                         af_family_slock_key_strings[sk->sk_family],
                         af_family_slock_keys + sk->sk_family,
                         af_family_key_strings[sk->sk_family],
                         af_family_keys + sk->sk_family);
 }
 
 static void sock_copy(struct sock *nsk, const struct sock *osk)
 {
 #ifdef CONFIG_SECURITY_NETWORK
         void *sptr = nsk->sk_security;
 #endif
 
         memcpy(nsk, osk, osk->sk_prot->obj_size);
 #ifdef CONFIG_SECURITY_NETWORK
         nsk->sk_security = sptr;
         security_sk_clone(osk, nsk);
 #endif
 }
 
 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
                 int family)
 {
         struct sock *sk;
         struct kmem_cache *slab;
 
         slab = prot->slab;
         if (slab != NULL)
                 sk = kmem_cache_alloc(slab, priority);
         else
                 sk = kmalloc(prot->obj_size, priority);
 
         if (sk != NULL) {
                 if (security_sk_alloc(sk, family, priority))
                         goto out_free;
 
                 if (!try_module_get(prot->owner))
                         goto out_free_sec;
         }
 
         return sk;
 
 out_free_sec:
         security_sk_free(sk);
 out_free:
         if (slab != NULL)
                 kmem_cache_free(slab, sk);
         else
                 kfree(sk);
         return NULL;
 }
 
 static void sk_prot_free(struct proto *prot, struct sock *sk)
 {
         struct kmem_cache *slab;
         struct module *owner;
 
         owner = prot->owner;
         slab = prot->slab;
 
         security_sk_free(sk);
         if (slab != NULL)
                 kmem_cache_free(slab, sk);
         else
                 kfree(sk);
         module_put(owner);
 }
 
 /**
  *        sk_alloc - All socket objects are allocated here
  *        @net: the applicable net namespace
  *        @family: protocol family
  *        @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
  *        @prot: struct proto associated with this new sock instance
  */
 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
                       struct proto *prot)
 {
         struct sock *sk;
 
         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
         if (sk) {
                 sk->sk_family = family;
                 /*
                  * See comment in struct sock definition to understand
                  * why we need sk_prot_creator -acme
                  */
                 sk->sk_prot = sk->sk_prot_creator = prot;
                 sock_lock_init(sk);
                 sock_net_set(sk, get_net(net));
         }
 
         return sk;
 }
 
 void sk_free(struct sock *sk)
 {
         struct sk_filter *filter;
 
         if (sk->sk_destruct)
                 sk->sk_destruct(sk);
 
         filter = rcu_dereference(sk->sk_filter);
         if (filter) {
                 sk_filter_uncharge(sk, filter);
                 rcu_assign_pointer(sk->sk_filter, NULL);
         }
 
         sock_disable_timestamp(sk);
 
         if (atomic_read(&sk->sk_omem_alloc))
                 printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
                        __func__, atomic_read(&sk->sk_omem_alloc));
 
         put_net(sock_net(sk));
         sk_prot_free(sk->sk_prot_creator, sk);
 }
 
 /*
  * Last sock_put should drop referrence to sk->sk_net. It has already
  * been dropped in sk_change_net. Taking referrence to stopping namespace
  * is not an option.
  * Take referrence to a socket to remove it from hash _alive_ and after that
  * destroy it in the context of init_net.
  */
 void sk_release_kernel(struct sock *sk)
 {
         if (sk == NULL || sk->sk_socket == NULL)
                 return;
 
         sock_hold(sk);
         sock_release(sk->sk_socket);
         release_net(sock_net(sk));
         sock_net_set(sk, get_net(&init_net));
         sock_put(sk);
 }
 EXPORT_SYMBOL(sk_release_kernel);
 
struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
{
        struct sock *newsk;

        newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
        if (newsk != NULL) {
                struct sk_filter *filter;

                sock_copy(newsk, sk);

                /* SANITY */
                get_net(sock_net(newsk));
                sk_node_init(&newsk->sk_node);
                sock_lock_init(newsk);
                bh_lock_sock(newsk);
                newsk->sk_backlog.head        = newsk->sk_backlog.tail = NULL;

                atomic_set(&newsk->sk_rmem_alloc, 0);
                atomic_set(&newsk->sk_wmem_alloc, 0);
                atomic_set(&newsk->sk_omem_alloc, 0);
                skb_queue_head_init(&newsk->sk_receive_queue);
                skb_queue_head_init(&newsk->sk_write_queue);
#ifdef CONFIG_NET_DMA
                skb_queue_head_init(&newsk->sk_async_wait_queue);
#endif

                rwlock_init(&newsk->sk_dst_lock);
                rwlock_init(&newsk->sk_callback_lock);
                lockdep_set_class_and_name(&newsk->sk_callback_lock,
                                af_callback_keys + newsk->sk_family,
                                af_family_clock_key_strings[newsk->sk_family]);

                newsk->sk_dst_cache        = NULL;
                newsk->sk_wmem_queued        = 0;
                newsk->sk_forward_alloc = 0;
                newsk->sk_send_head        = NULL;
                newsk->sk_userlocks        = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;

                sock_reset_flag(newsk, SOCK_DONE);
                skb_queue_head_init(&newsk->sk_error_queue);

                filter = newsk->sk_filter;
                if (filter != NULL)
                        sk_filter_charge(newsk, filter);

                if (unlikely(xfrm_sk_clone_policy(newsk))) {
                        /* It is still raw copy of parent, so invalidate
                         * destructor and make plain sk_free() */
                        newsk->sk_destruct = NULL;
                        sk_free(newsk);
                        newsk = NULL;
                        goto out;
                }

                newsk->sk_err           = 0;
                newsk->sk_priority = 0;
                atomic_set(&newsk->sk_refcnt, 2);

                /*
                 * Increment the counter in the same struct proto as the master
                 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
                 * is the same as sk->sk_prot->socks, as this field was copied
                 * with memcpy).
                 *
                 * This _changes_ the previous behaviour, where
                 * tcp_create_openreq_child always was incrementing the
                 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
                 * to be taken into account in all callers. -acme
                 */
                sk_refcnt_debug_inc(newsk);
                sk_set_socket(newsk, NULL);
                newsk->sk_sleep         = NULL;

                if (newsk->sk_prot->sockets_allocated)
                        atomic_inc(newsk->sk_prot->sockets_allocated);
        }
out:
        return newsk;
}

EXPORT_SYMBOL_GPL(sk_clone);

void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
{
        __sk_dst_set(sk, dst);
        sk->sk_route_caps = dst->dev->features;
        if (sk->sk_route_caps & NETIF_F_GSO)
                sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
        if (sk_can_gso(sk)) {
                if (dst->header_len) {
                        sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
                } else {
                        sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
                        sk->sk_gso_max_size = dst->dev->gso_max_size;
                }
        }
}
EXPORT_SYMBOL_GPL(sk_setup_caps);

void __init sk_init(void)
{
        if (num_physpages <= 4096) {
                sysctl_wmem_max = 32767;
                sysctl_rmem_max = 32767;
                sysctl_wmem_default = 32767;
                sysctl_rmem_default = 32767;
        } else if (num_physpages >= 131072) {
                sysctl_wmem_max = 131071;
                sysctl_rmem_max = 131071;
        }
}

/*
 *        Simple resource managers for sockets.
 */


/*
 * Write buffer destructor automatically called from kfree_skb.
 */
void sock_wfree(struct sk_buff *skb)
{
        struct sock *sk = skb->sk;

        /* In case it might be waiting for more memory. */
        atomic_sub(skb->truesize, &sk->sk_wmem_alloc);
        if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE))
                sk->sk_write_space(sk);
        sock_put(sk);
}

/*
 * Read buffer destructor automatically called from kfree_skb.
 */
void sock_rfree(struct sk_buff *skb)
{
        struct sock *sk = skb->sk;

        skb_truesize_check(skb);
        atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
        sk_mem_uncharge(skb->sk, skb->truesize);
}


int sock_i_uid(struct sock *sk)
{
        int uid;

        read_lock(&sk->sk_callback_lock);
        uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
        read_unlock(&sk->sk_callback_lock);
        return uid;
}

unsigned long sock_i_ino(struct sock *sk)
{
        unsigned long ino;

        read_lock(&sk->sk_callback_lock);
        ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
        read_unlock(&sk->sk_callback_lock);
        return ino;
}

/*
 * Allocate a skb from the socket's send buffer.
 */
struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
                             gfp_t priority)
{
        if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
                struct sk_buff * skb = alloc_skb(size, priority);
                if (skb) {
                        skb_set_owner_w(skb, sk);
                        return skb;
                }
        }
        return NULL;
}

/*
 * Allocate a skb from the socket's receive buffer.
 */
struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
                             gfp_t priority)
{
        if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
                struct sk_buff *skb = alloc_skb(size, priority);
                if (skb) {
                        skb_set_owner_r(skb, sk);
                        return skb;
                }
        }
        return NULL;
}

/*
 * Allocate a memory block from the socket's option memory buffer.
 */
void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
{
        if ((unsigned)size <= sysctl_optmem_max &&
            atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
                void *mem;
                /* First do the add, to avoid the race if kmalloc
                 * might sleep.
                 */
                atomic_add(size, &sk->sk_omem_alloc);
                mem = kmalloc(size, priority);
                if (mem)
                        return mem;
                atomic_sub(size, &sk->sk_omem_alloc);
        }
        return NULL;
}

/*
 * Free an option memory block.
 */
void sock_kfree_s(struct sock *sk, void *mem, int size)
{
        kfree(mem);
        atomic_sub(size, &sk->sk_omem_alloc);
}

/* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
   I think, these locks should be removed for datagram sockets.
 */
static long sock_wait_for_wmem(struct sock * sk, long timeo)
{
        DEFINE_WAIT(wait);

        clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
        for (;;) {
                if (!timeo)
                        break;
                if (signal_pending(current))
                        break;
                set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
                prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
                if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
                        break;
                if (sk->sk_shutdown & SEND_SHUTDOWN)
                        break;
                if (sk->sk_err)
                        break;
                timeo = schedule_timeout(timeo);
        }
        finish_wait(sk->sk_sleep, &wait);
        return timeo;
}


/*
 *        Generic send/receive buffer handlers
 */

static struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
                                            unsigned long header_len,
                                            unsigned long data_len,
                                            int noblock, int *errcode)
{
        struct sk_buff *skb;
        gfp_t gfp_mask;
        long timeo;
        int err;

        gfp_mask = sk->sk_allocation;
        if (gfp_mask & __GFP_WAIT)
                gfp_mask |= __GFP_REPEAT;

        timeo = sock_sndtimeo(sk, noblock);
        while (1) {
                err = sock_error(sk);
                if (err != 0)
                        goto failure;

                err = -EPIPE;
                if (sk->sk_shutdown & SEND_SHUTDOWN)
                        goto failure;

                if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
                        skb = alloc_skb(header_len, gfp_mask);
                        if (skb) {
                                int npages;
                                int i;

                                /* No pages, we're done... */
                                if (!data_len)
                                        break;

                                npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
                                skb->truesize += data_len;
                                skb_shinfo(skb)->nr_frags = npages;
                                for (i = 0; i < npages; i++) {
                                        struct page *page;
                                        skb_frag_t *frag;

                                        page = alloc_pages(sk->sk_allocation, 0);
                                        if (!page) {
                                                err = -ENOBUFS;
                                                skb_shinfo(skb)->nr_frags = i;
                                                kfree_skb(skb);
                                                goto failure;
                                        }

                                        frag = &skb_shinfo(skb)->frags[i];
                                        frag->page = page;
                                        frag->page_offset = 0;
                                        frag->size = (data_len >= PAGE_SIZE ?
                                                      PAGE_SIZE :
                                                      data_len);
                                        data_len -= PAGE_SIZE;
                                }

                                /* Full success... */
                                break;
                        }
                        err = -ENOBUFS;
                        goto failure;
                }
                set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
                set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
                err = -EAGAIN;
                if (!timeo)
                        goto failure;
                if (signal_pending(current))
                        goto interrupted;
                timeo = sock_wait_for_wmem(sk, timeo);
        }

        skb_set_owner_w(skb, sk);
        return skb;

interrupted:
        err = sock_intr_errno(timeo);
failure:
        *errcode = err;
        return NULL;
}

struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
                                    int noblock, int *errcode)
{
        return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
}

static void __lock_sock(struct sock *sk)
{
        DEFINE_WAIT(wait);

        for (;;) {
                prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
                                        TASK_UNINTERRUPTIBLE);
                spin_unlock_bh(&sk->sk_lock.slock);
                schedule();
                spin_lock_bh(&sk->sk_lock.slock);
                if (!sock_owned_by_user(sk))
                        break;
        }
        finish_wait(&sk->sk_lock.wq, &wait);
}

static void __release_sock(struct sock *sk)
{
        struct sk_buff *skb = sk->sk_backlog.head;

        do {
                sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
                bh_unlock_sock(sk);

                do {
                        struct sk_buff *next = skb->next;

                        skb->next = NULL;
                        sk_backlog_rcv(sk, skb);

                        /*
                         * We are in process context here with softirqs
                         * disabled, use cond_resched_softirq() to preempt.
                         * This is safe to do because we've taken the backlog
                         * queue private:
                         */
                        cond_resched_softirq();

                        skb = next;
                } while (skb != NULL);

                bh_lock_sock(sk);
        } while ((skb = sk->sk_backlog.head) != NULL);
}

/**
 * sk_wait_data - wait for data to arrive at sk_receive_queue
 * @sk:    sock to wait on
 * @timeo: for how long
 *
 * Now socket state including sk->sk_err is changed only under lock,
 * hence we may omit checks after joining wait queue.
 * We check receive queue before schedule() only as optimization;
 * it is very likely that release_sock() added new data.
 */
int sk_wait_data(struct sock *sk, long *timeo)
{
        int rc;
        DEFINE_WAIT(wait);

        prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
        set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
        rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
        clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
        finish_wait(sk->sk_sleep, &wait);
        return rc;
}

EXPORT_SYMBOL(sk_wait_data);

/**
 *        __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
 *        @sk: socket
 *        @size: memory size to allocate
 *        @kind: allocation type
 *
 *        If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
 *        rmem allocation. This function assumes that protocols which have
 *        memory_pressure use sk_wmem_queued as write buffer accounting.
 */
int __sk_mem_schedule(struct sock *sk, int size, int kind)
{
        struct proto *prot = sk->sk_prot;
        int amt = sk_mem_pages(size);
        int allocated;

        sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
        allocated = atomic_add_return(amt, prot->memory_allocated);

        /* Under limit. */
        if (allocated <= prot->sysctl_mem[0]) {
                if (prot->memory_pressure && *prot->memory_pressure)
                        *prot->memory_pressure = 0;
                return 1;
        }

        /* Under pressure. */
        if (allocated > prot->sysctl_mem[1])
                if (prot->enter_memory_pressure)
                        prot->enter_memory_pressure(sk);

        /* Over hard limit. */
        if (allocated > prot->sysctl_mem[2])
                goto suppress_allocation;

        /* guarantee minimum buffer size under pressure */
        if (kind == SK_MEM_RECV) {
                if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
                        return 1;
        } else { /* SK_MEM_SEND */
                if (sk->sk_type == SOCK_STREAM) {
                        if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
                                return 1;
                } else if (atomic_read(&sk->sk_wmem_alloc) <
                           prot->sysctl_wmem[0])
                                return 1;
        }

        if (prot->memory_pressure) {
                if (!*prot->memory_pressure ||
                    prot->sysctl_mem[2] > atomic_read(prot->sockets_allocated) *
                    sk_mem_pages(sk->sk_wmem_queued +
                                 atomic_read(&sk->sk_rmem_alloc) +
                                 sk->sk_forward_alloc))
                        return 1;
        }

suppress_allocation:

        if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
                sk_stream_moderate_sndbuf(sk);

                /* Fail only if socket is _under_ its sndbuf.
                 * In this case we cannot block, so that we have to fail.
                 */
                if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
                        return 1;
        }

        /* Alas. Undo changes. */
        sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
        atomic_sub(amt, prot->memory_allocated);
        return 0;
}

EXPORT_SYMBOL(__sk_mem_schedule);

/**
 *        __sk_reclaim - reclaim memory_allocated
 *        @sk: socket
 */
void __sk_mem_reclaim(struct sock *sk)
{
        struct proto *prot = sk->sk_prot;

        atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
                   prot->memory_allocated);
        sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;

        if (prot->memory_pressure && *prot->memory_pressure &&
            (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
                *prot->memory_pressure = 0;
}

EXPORT_SYMBOL(__sk_mem_reclaim);


/*
 * Set of default routines for initialising struct proto_ops when
 * the protocol does not support a particular function. In certain
 * cases where it makes no sense for a protocol to have a "do nothing"
 * function, some default processing is provided.
 */

int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
{
        return -EOPNOTSUPP;
}

int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
                    int len, int flags)
{
        return -EOPNOTSUPP;
}

int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
{
        return -EOPNOTSUPP;
}

int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
{
        return -EOPNOTSUPP;
}

int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
                    int *len, int peer)
{
        return -EOPNOTSUPP;
}

unsigned int sock_no_poll(struct file * file, struct socket *sock, poll_table *pt)
{
        return 0;
}

int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
        return -EOPNOTSUPP;
}

int sock_no_listen(struct socket *sock, int backlog)
{
        return -EOPNOTSUPP;
}

int sock_no_shutdown(struct socket *sock, int how)
{
        return -EOPNOTSUPP;
}

int sock_no_setsockopt(struct socket *sock, int level, int optname,
                    char __user *optval, int optlen)
{
        return -EOPNOTSUPP;
}

int sock_no_getsockopt(struct socket *sock, int level, int optname,
                    char __user *optval, int __user *optlen)
{
        return -EOPNOTSUPP;
}

int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
                    size_t len)
{
        return -EOPNOTSUPP;
}

int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
                    size_t len, int flags)
{
        return -EOPNOTSUPP;
}

int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
{
        /* Mirror missing mmap method error code */
        return -ENODEV;
}

ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
{
        ssize_t res;
        struct msghdr msg = {.msg_flags = flags};
        struct kvec iov;
        char *kaddr = kmap(page);
        iov.iov_base = kaddr + offset;
        iov.iov_len = size;
        res = kernel_sendmsg(sock, &msg, &iov, 1, size);
        kunmap(page);
        return res;
}

/*
 *        Default Socket Callbacks
 */

static void sock_def_wakeup(struct sock *sk)
{
        read_lock(&sk->sk_callback_lock);
        if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                wake_up_interruptible_all(sk->sk_sleep);
        read_unlock(&sk->sk_callback_lock);
}

static void sock_def_error_report(struct sock *sk)
{
        read_lock(&sk->sk_callback_lock);
        if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                wake_up_interruptible(sk->sk_sleep);
        sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
        read_unlock(&sk->sk_callback_lock);
}

static void sock_def_readable(struct sock *sk, int len)
{
        read_lock(&sk->sk_callback_lock);
        if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                wake_up_interruptible_sync(sk->sk_sleep);
        sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
        read_unlock(&sk->sk_callback_lock);
}

static void sock_def_write_space(struct sock *sk)
{
        read_lock(&sk->sk_callback_lock);

        /* Do not wake up a writer until he can make "significant"
         * progress.  --DaveM
         */
        if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
                if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                        wake_up_interruptible_sync(sk->sk_sleep);

                /* Should agree with poll, otherwise some programs break */
                if (sock_writeable(sk))
                        sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
        }

        read_unlock(&sk->sk_callback_lock);
}

static void sock_def_destruct(struct sock *sk)
{
        kfree(sk->sk_protinfo);
}

void sk_send_sigurg(struct sock *sk)
{
        if (sk->sk_socket && sk->sk_socket->file)
                if (send_sigurg(&sk->sk_socket->file->f_owner))
                        sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
}

void sk_reset_timer(struct sock *sk, struct timer_list* timer,
                    unsigned long expires)
{
        if (!mod_timer(timer, expires))
                sock_hold(sk);
}

EXPORT_SYMBOL(sk_reset_timer);

void sk_stop_timer(struct sock *sk, struct timer_list* timer)
{
        if (timer_pending(timer) && del_timer(timer))
                __sock_put(sk);
}

EXPORT_SYMBOL(sk_stop_timer);

void sock_init_data(struct socket *sock, struct sock *sk)
{
        skb_queue_head_init(&sk->sk_receive_queue);
        skb_queue_head_init(&sk->sk_write_queue);
        skb_queue_head_init(&sk->sk_error_queue);
#ifdef CONFIG_NET_DMA
        skb_queue_head_init(&sk->sk_async_wait_queue);
#endif

        sk->sk_send_head        =        NULL;

        init_timer(&sk->sk_timer);

        sk->sk_allocation        =        GFP_KERNEL;
        sk->sk_rcvbuf                =        sysctl_rmem_default;
        sk->sk_sndbuf                =        sysctl_wmem_default;
        sk->sk_state                =        TCP_CLOSE;
        sk_set_socket(sk, sock);

        sock_set_flag(sk, SOCK_ZAPPED);

        if (sock) {
                sk->sk_type        =        sock->type;
                sk->sk_sleep        =        &sock->wait;
                sock->sk        =        sk;
        } else
                sk->sk_sleep        =        NULL;

        rwlock_init(&sk->sk_dst_lock);
        rwlock_init(&sk->sk_callback_lock);
        lockdep_set_class_and_name(&sk->sk_callback_lock,
                        af_callback_keys + sk->sk_family,
                        af_family_clock_key_strings[sk->sk_family]);

        sk->sk_state_change        =        sock_def_wakeup;
        sk->sk_data_ready        =        sock_def_readable;
        sk->sk_write_space        =        sock_def_write_space;
        sk->sk_error_report        =        sock_def_error_report;
        sk->sk_destruct                =        sock_def_destruct;

        sk->sk_sndmsg_page        =        NULL;
        sk->sk_sndmsg_off        =        0;

        sk->sk_peercred.pid         =        0;
        sk->sk_peercred.uid        =        -1;
        sk->sk_peercred.gid        =        -1;
        sk->sk_write_pending        =        0;
        sk->sk_rcvlowat                =        1;
        sk->sk_rcvtimeo                =        MAX_SCHEDULE_TIMEOUT;
        sk->sk_sndtimeo                =        MAX_SCHEDULE_TIMEOUT;

        sk->sk_stamp = ktime_set(-1L, 0);

        atomic_set(&sk->sk_refcnt, 1);
        atomic_set(&sk->sk_drops, 0);
}

void lock_sock_nested(struct sock *sk, int subclass)
{
        might_sleep();
        spin_lock_bh(&sk->sk_lock.slock);
        if (sk->sk_lock.owned)
                __lock_sock(sk);
        sk->sk_lock.owned = 1;
        spin_unlock(&sk->sk_lock.slock);
        /*
         * The sk_lock has mutex_lock() semantics here:
         */
        mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
        local_bh_enable();
}

EXPORT_SYMBOL(lock_sock_nested);

void release_sock(struct sock *sk)
{
        /*
         * The sk_lock has mutex_unlock() semantics:
         */
        mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);

        spin_lock_bh(&sk->sk_lock.slock);
        if (sk->sk_backlog.tail)
                __release_sock(sk);
        sk->sk_lock.owned = 0;
        if (waitqueue_active(&sk->sk_lock.wq))
                wake_up(&sk->sk_lock.wq);
        spin_unlock_bh(&sk->sk_lock.slock);
}
EXPORT_SYMBOL(release_sock);

int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
{
        struct timeval tv;
        if (!sock_flag(sk, SOCK_TIMESTAMP))
                sock_enable_timestamp(sk);
        tv = ktime_to_timeval(sk->sk_stamp);
        if (tv.tv_sec == -1)
                return -ENOENT;
        if (tv.tv_sec == 0) {
                sk->sk_stamp = ktime_get_real();
                tv = ktime_to_timeval(sk->sk_stamp);
        }
        return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
}
EXPORT_SYMBOL(sock_get_timestamp);

int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
{
        struct timespec ts;
        if (!sock_flag(sk, SOCK_TIMESTAMP))
                sock_enable_timestamp(sk);
        ts = ktime_to_timespec(sk->sk_stamp);
        if (ts.tv_sec == -1)
                return -ENOENT;
        if (ts.tv_sec == 0) {
                sk->sk_stamp = ktime_get_real();
                ts = ktime_to_timespec(sk->sk_stamp);
        }
        return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
}
EXPORT_SYMBOL(sock_get_timestampns);

void sock_enable_timestamp(struct sock *sk)
{
        if (!sock_flag(sk, SOCK_TIMESTAMP)) {
                sock_set_flag(sk, SOCK_TIMESTAMP);
                net_enable_timestamp();
        }
}

/*
 *        Get a socket option on an socket.
 *
 *        FIX: POSIX 1003.1g is very ambiguous here. It states that
 *        asynchronous errors should be reported by getsockopt. We assume
 *        this means if you specify SO_ERROR (otherwise whats the point of it).
 */
int sock_common_getsockopt(struct socket *sock, int level, int optname,
                           char __user *optval, int __user *optlen)
{
        struct sock *sk = sock->sk;

        return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
}

EXPORT_SYMBOL(sock_common_getsockopt);

#ifdef CONFIG_COMPAT
int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
                                  char __user *optval, int __user *optlen)
{
        struct sock *sk = sock->sk;

        if (sk->sk_prot->compat_getsockopt != NULL)
                return sk->sk_prot->compat_getsockopt(sk, level, optname,
                                                      optval, optlen);
        return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
}
EXPORT_SYMBOL(compat_sock_common_getsockopt);
#endif

int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
                        struct msghdr *msg, size_t size, int flags)
{
        struct sock *sk = sock->sk;
        int addr_len = 0;
        int err;

        err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
                                   flags & ~MSG_DONTWAIT, &addr_len);
        if (err >= 0)
                msg->msg_namelen = addr_len;
        return err;
}

EXPORT_SYMBOL(sock_common_recvmsg);

/*
 *        Set socket options on an inet socket.
 */
int sock_common_setsockopt(struct socket *sock, int level, int optname,
                           char __user *optval, int optlen)
{
        struct sock *sk = sock->sk;

        return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
}

EXPORT_SYMBOL(sock_common_setsockopt);

#ifdef CONFIG_COMPAT
int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
                                  char __user *optval, int optlen)
{
        struct sock *sk = sock->sk;

        if (sk->sk_prot->compat_setsockopt != NULL)
                return sk->sk_prot->compat_setsockopt(sk, level, optname,
                                                      optval, optlen);
        return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
}
EXPORT_SYMBOL(compat_sock_common_setsockopt);
#endif

void sk_common_release(struct sock *sk)
{
        if (sk->sk_prot->destroy)
                sk->sk_prot->destroy(sk);

        /*
         * Observation: when sock_common_release is called, processes have
         * no access to socket. But net still has.
         * Step one, detach it from networking:
         *
         * A. Remove from hash tables.
         */

        sk->sk_prot->unhash(sk);

        /*
         * In this point socket cannot receive new packets, but it is possible
         * that some packets are in flight because some CPU runs receiver and
         * did hash table lookup before we unhashed socket. They will achieve
         * receive queue and will be purged by socket destructor.
         *
         * Also we still have packets pending on receive queue and probably,
         * our own packets waiting in device queues. sock_destroy will drain
         * receive queue, but transmitted packets will delay socket destruction
         * until the last reference will be released.
         */

        sock_orphan(sk);

        xfrm_sk_free_policy(sk);

        sk_refcnt_debug_release(sk);
        sock_put(sk);
}

EXPORT_SYMBOL(sk_common_release);

static DEFINE_RWLOCK(proto_list_lock);
static LIST_HEAD(proto_list);

#ifdef CONFIG_PROC_FS
#define PROTO_INUSE_NR        64        /* should be enough for the first time */
struct prot_inuse {
        int val[PROTO_INUSE_NR];
};

static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);

#ifdef CONFIG_NET_NS
void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
{
        int cpu = smp_processor_id();
        per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
}
EXPORT_SYMBOL_GPL(sock_prot_inuse_add);

int sock_prot_inuse_get(struct net *net, struct proto *prot)
{
        int cpu, idx = prot->inuse_idx;
        int res = 0;

        for_each_possible_cpu(cpu)
                res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];

        return res >= 0 ? res : 0;
}
EXPORT_SYMBOL_GPL(sock_prot_inuse_get);

static int sock_inuse_init_net(struct net *net)
{
        net->core.inuse = alloc_percpu(struct prot_inuse);
        return net->core.inuse ? 0 : -ENOMEM;
}

static void sock_inuse_exit_net(struct net *net)
{
        free_percpu(net->core.inuse);
}

static struct pernet_operations net_inuse_ops = {
        .init = sock_inuse_init_net,
        .exit = sock_inuse_exit_net,
};

static __init int net_inuse_init(void)
{
        if (register_pernet_subsys(&net_inuse_ops))
                panic("Cannot initialize net inuse counters");

        return 0;
}

core_initcall(net_inuse_init);
#else
static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);

void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
{
        __get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
}
EXPORT_SYMBOL_GPL(sock_prot_inuse_add);

int sock_prot_inuse_get(struct net *net, struct proto *prot)
{
        int cpu, idx = prot->inuse_idx;
        int res = 0;

        for_each_possible_cpu(cpu)
                res += per_cpu(prot_inuse, cpu).val[idx];

        return res >= 0 ? res : 0;
}
EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
#endif

static void assign_proto_idx(struct proto *prot)
{
        prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);

        if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
                printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
                return;
        }

        set_bit(prot->inuse_idx, proto_inuse_idx);
}

static void release_proto_idx(struct proto *prot)
{
        if (prot->inuse_idx != PROTO_INUSE_NR - 1)
                clear_bit(prot->inuse_idx, proto_inuse_idx);
}
#else
static inline void assign_proto_idx(struct proto *prot)
{
}

static inline void release_proto_idx(struct proto *prot)
{
}
#endif

int proto_register(struct proto *prot, int alloc_slab)
{
        if (alloc_slab) {
                prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
                                               SLAB_HWCACHE_ALIGN, NULL);

                if (prot->slab == NULL) {
                        printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
                               prot->name);
                        goto out;
                }

                if (prot->rsk_prot != NULL) {
                        static const char mask[] = "request_sock_%s";

                        prot->rsk_prot->slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
                        if (prot->rsk_prot->slab_name == NULL)
                                goto out_free_sock_slab;

                        sprintf(prot->rsk_prot->slab_name, mask, prot->name);
                        prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
                                                                 prot->rsk_prot->obj_size, 0,
                                                                 SLAB_HWCACHE_ALIGN, NULL);

                        if (prot->rsk_prot->slab == NULL) {
                                printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
                                       prot->name);
                                goto out_free_request_sock_slab_name;
                        }
                }

                if (prot->twsk_prot != NULL) {
                        static const char mask[] = "tw_sock_%s";

                        prot->twsk_prot->twsk_slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);

                        if (prot->twsk_prot->twsk_slab_name == NULL)
                                goto out_free_request_sock_slab;

                        sprintf(prot->twsk_prot->twsk_slab_name, mask, prot->name);
                        prot->twsk_prot->twsk_slab =
                                kmem_cache_create(prot->twsk_prot->twsk_slab_name,
                                                  prot->twsk_prot->twsk_obj_size,
                                                  0, SLAB_HWCACHE_ALIGN,
                                                  NULL);
                        if (prot->twsk_prot->twsk_slab == NULL)
                                goto out_free_timewait_sock_slab_name;
                }
        }

        write_lock(&proto_list_lock);
        list_add(&prot->node, &proto_list);
        assign_proto_idx(prot);
        write_unlock(&proto_list_lock);
        return 0;

out_free_timewait_sock_slab_name:
        kfree(prot->twsk_prot->twsk_slab_name);
out_free_request_sock_slab:
        if (prot->rsk_prot && prot->rsk_prot->slab) {
                kmem_cache_destroy(prot->rsk_prot->slab);
                prot->rsk_prot->slab = NULL;
        }
out_free_request_sock_slab_name:
        kfree(prot->rsk_prot->slab_name);
out_free_sock_slab:
        kmem_cache_destroy(prot->slab);
        prot->slab = NULL;
out:
        return -ENOBUFS;
}

EXPORT_SYMBOL(proto_register);

void proto_unregister(struct proto *prot)
{
        write_lock(&proto_list_lock);
        release_proto_idx(prot);
        list_del(&prot->node);
        write_unlock(&proto_list_lock);

        if (prot->slab != NULL) {
                kmem_cache_destroy(prot->slab);
                prot->slab = NULL;
        }

        if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
                kmem_cache_destroy(prot->rsk_prot->slab);
                kfree(prot->rsk_prot->slab_name);
                prot->rsk_prot->slab = NULL;
        }

        if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
                kmem_cache_destroy(prot->twsk_prot->twsk_slab);
                kfree(prot->twsk_prot->twsk_slab_name);
                prot->twsk_prot->twsk_slab = NULL;
        }
}

EXPORT_SYMBOL(proto_unregister);

#ifdef CONFIG_PROC_FS
static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
        __acquires(proto_list_lock)
{
        read_lock(&proto_list_lock);
        return seq_list_start_head(&proto_list, *pos);
}

static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
        return seq_list_next(v, &proto_list, pos);
}

static void proto_seq_stop(struct seq_file *seq, void *v)
        __releases(proto_list_lock)
{
        read_unlock(&proto_list_lock);
}

static char proto_method_implemented(const void *method)
{
        return method == NULL ? 'n' : 'y';
}

static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
{
        seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
                        "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
                   proto->name,
                   proto->obj_size,
                   proto->sockets_allocated != NULL ? atomic_read(proto->sockets_allocated) : -1,
                   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
                   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
                   proto->max_header,
                   proto->slab == NULL ? "no" : "yes",
                   module_name(proto->owner),
                   proto_method_implemented(proto->close),
                   proto_method_implemented(proto->connect),
                   proto_method_implemented(proto->disconnect),
                   proto_method_implemented(proto->accept),
                   proto_method_implemented(proto->ioctl),
                   proto_method_implemented(proto->init),
                   proto_method_implemented(proto->destroy),
                   proto_method_implemented(proto->shutdown),
                   proto_method_implemented(proto->setsockopt),
                   proto_method_implemented(proto->getsockopt),
                   proto_method_implemented(proto->sendmsg),
                   proto_method_implemented(proto->recvmsg),
                   proto_method_implemented(proto->sendpage),
                   proto_method_implemented(proto->bind),
                   proto_method_implemented(proto->backlog_rcv),
                   proto_method_implemented(proto->hash),
                   proto_method_implemented(proto->unhash),
                   proto_method_implemented(proto->get_port),
                   proto_method_implemented(proto->enter_memory_pressure));
}

static int proto_seq_show(struct seq_file *seq, void *v)
{
        if (v == &proto_list)
                seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
                           "protocol",
                           "size",
                           "sockets",
                           "memory",
                           "press",
                           "maxhdr",
                           "slab",
                           "module",
                           "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
        else
                proto_seq_printf(seq, list_entry(v, struct proto, node));
        return 0;
}

static const struct seq_operations proto_seq_ops = {
        .start  = proto_seq_start,
        .next   = proto_seq_next,
        .stop   = proto_seq_stop,
        .show   = proto_seq_show,
};

static int proto_seq_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &proto_seq_ops);
}

static const struct file_operations proto_seq_fops = {
        .owner                = THIS_MODULE,
        .open                = proto_seq_open,
        .read                = seq_read,
        .llseek                = seq_lseek,
        .release        = seq_release,
};

static int __init proto_init(void)
{
        /* register /proc/net/protocols */
        return proc_net_fops_create(&init_net, "protocols", S_IRUGO, &proto_seq_fops) == NULL ? -ENOBUFS : 0;
}

subsys_initcall(proto_init);

#endif /* PROC_FS */

EXPORT_SYMBOL(sk_alloc);
EXPORT_SYMBOL(sk_free);
EXPORT_SYMBOL(sk_send_sigurg);
EXPORT_SYMBOL(sock_alloc_send_skb);
EXPORT_SYMBOL(sock_init_data);
EXPORT_SYMBOL(sock_kfree_s);
EXPORT_SYMBOL(sock_kmalloc);
EXPORT_SYMBOL(sock_no_accept);
EXPORT_SYMBOL(sock_no_bind);
EXPORT_SYMBOL(sock_no_connect);
EXPORT_SYMBOL(sock_no_getname);
EXPORT_SYMBOL(sock_no_getsockopt);
EXPORT_SYMBOL(sock_no_ioctl);
EXPORT_SYMBOL(sock_no_listen);
EXPORT_SYMBOL(sock_no_mmap);
EXPORT_SYMBOL(sock_no_poll);
EXPORT_SYMBOL(sock_no_recvmsg);
EXPORT_SYMBOL(sock_no_sendmsg);
EXPORT_SYMBOL(sock_no_sendpage);
EXPORT_SYMBOL(sock_no_setsockopt);
EXPORT_SYMBOL(sock_no_shutdown);
EXPORT_SYMBOL(sock_no_socketpair);
EXPORT_SYMBOL(sock_rfree);
EXPORT_SYMBOL(sock_setsockopt);
EXPORT_SYMBOL(sock_wfree);
EXPORT_SYMBOL(sock_wmalloc);
EXPORT_SYMBOL(sock_i_uid);
EXPORT_SYMBOL(sock_i_ino);
EXPORT_SYMBOL(sysctl_optmem_max);