Staging
v0.5.1
v0.5.1
https://github.com/torvalds/linux
sock.c
/*
* 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.
*
*
* Version: $Id: sock.c,v 1.117 2002/02/01 22:01:03 davem Exp $
*
* Authors: Ross Biro, <bir7@leland.Stanford.Edu>
* 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/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/module.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 <asm/uaccess.h>
#include <asm/system.h>
#include <linux/netdevice.h>
#include <net/protocol.h>
#include <linux/skbuff.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
/* 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 = SK_WMEM_MAX;
__u32 sysctl_rmem_max = SK_RMEM_MAX;
__u32 sysctl_wmem_default = SK_WMEM_MAX;
__u32 sysctl_rmem_default = SK_RMEM_MAX;
/* Maximal space eaten by iovec or ancilliary data plus some space */
int sysctl_optmem_max = 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;
*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();
}
}
/*
* 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;
struct sk_filter *filter;
int val;
int valbool;
struct linger ling;
int ret = 0;
/*
* Options without arguments
*/
#ifdef SO_DONTLINGER /* Compatibility item... */
switch (optname) {
case SO_DONTLINGER:
sock_reset_flag(sk, SOCK_LINGER);
return 0;
}
#endif
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
sk->sk_debug = valbool;
break;
case SO_REUSEADDR:
sk->sk_reuse = valbool;
break;
case SO_TYPE:
case SO_ERROR:
ret = -ENOPROTOOPT;
break;
case SO_DONTROUTE:
sk->sk_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;
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_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;
sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
/* FIXME: is this lower bound the right one? */
if ((val * 2) < SOCK_MIN_RCVBUF)
sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
else
sk->sk_rcvbuf = val * 2;
break;
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 (ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
else
#endif
sk->sk_lingertime = ling.l_linger * HZ;
sock_set_flag(sk, SOCK_LINGER);
}
break;
case SO_BSDCOMPAT:
sock_warn_obsolete_bsdism("setsockopt");
break;
case SO_PASSCRED:
sock->passcred = valbool;
break;
case SO_TIMESTAMP:
sk->sk_rcvtstamp = valbool;
if (valbool)
sock_enable_timestamp(sk);
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;
#ifdef CONFIG_NETDEVICES
case SO_BINDTODEVICE:
{
char devname[IFNAMSIZ];
/* Sorry... */
if (!capable(CAP_NET_RAW)) {
ret = -EPERM;
break;
}
/* 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 (!valbool) {
sk->sk_bound_dev_if = 0;
} else {
if (optlen > IFNAMSIZ)
optlen = IFNAMSIZ;
if (copy_from_user(devname, optval, optlen)) {
ret = -EFAULT;
break;
}
/* Remove any cached route for this socket. */
sk_dst_reset(sk);
if (devname[0] == '\0') {
sk->sk_bound_dev_if = 0;
} else {
struct net_device *dev = dev_get_by_name(devname);
if (!dev) {
ret = -ENODEV;
break;
}
sk->sk_bound_dev_if = dev->ifindex;
dev_put(dev);
}
}
break;
}
#endif
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:
spin_lock_bh(&sk->sk_lock.slock);
filter = sk->sk_filter;
if (filter) {
sk->sk_filter = NULL;
spin_unlock_bh(&sk->sk_lock.slock);
sk_filter_release(sk, filter);
break;
}
spin_unlock_bh(&sk->sk_lock.slock);
ret = -ENONET;
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 = sk->sk_debug;
break;
case SO_DONTROUTE:
v.val = sk->sk_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 = sk->sk_rcvtstamp;
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 = sock->passcred;
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_PEERSEC:
return security_socket_getpeersec(sock, optval, optlen, len);
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;
}
static kmem_cache_t *sk_cachep;
/**
* sk_alloc - All socket objects are allocated here
* @family - protocol family
* @priority - for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
* @zero_it - zeroes the allocated sock
* @slab - alternate slab
*
* All socket objects are allocated here. If @zero_it is non-zero
* it should have the size of the are to be zeroed, because the
* private slabcaches have different sizes of the generic struct sock.
* 1 has been kept as a way to say sizeof(struct sock).
*/
struct sock *sk_alloc(int family, int priority, int zero_it, kmem_cache_t *slab)
{
struct sock *sk = NULL;
if (!slab)
slab = sk_cachep;
sk = kmem_cache_alloc(slab, priority);
if (sk) {
if (zero_it) {
memset(sk, 0,
zero_it == 1 ? sizeof(struct sock) : zero_it);
sk->sk_family = family;
sock_lock_init(sk);
}
sk->sk_slab = slab;
if (security_sk_alloc(sk, family, priority)) {
kmem_cache_free(slab, sk);
sk = NULL;
}
}
return sk;
}
void sk_free(struct sock *sk)
{
struct sk_filter *filter;
struct module *owner = sk->sk_owner;
if (sk->sk_destruct)
sk->sk_destruct(sk);
filter = sk->sk_filter;
if (filter) {
sk_filter_release(sk, filter);
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",
__FUNCTION__, atomic_read(&sk->sk_omem_alloc));
security_sk_free(sk);
kmem_cache_free(sk->sk_slab, sk);
module_put(owner);
}
void __init sk_init(void)
{
sk_cachep = kmem_cache_create("sock", sizeof(struct sock), 0,
SLAB_HWCACHE_ALIGN, NULL, NULL);
if (!sk_cachep)
printk(KERN_CRIT "sk_init: Cannot create sock SLAB cache!");
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 (!sk->sk_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;
atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
}
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, int 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, int 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, int 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;
unsigned int 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, sk->sk_allocation);
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->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);
/*
* 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,0,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(sk->sk_sleep);
sk_wake_async(sk,1,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(sk->sk_sleep);
/* Should agree with poll, otherwise some programs break */
if (sock_writeable(sk))
sk_wake_async(sk, 2, POLL_OUT);
}
read_unlock(&sk->sk_callback_lock);
}
static void sock_def_destruct(struct sock *sk)
{
if (sk->sk_protinfo)
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, 3, 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);
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->sk_zapped = 1;
sk->sk_socket = sock;
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);
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_owner = NULL;
sk->sk_stamp.tv_sec = -1L;
sk->sk_stamp.tv_usec = -1L;
atomic_set(&sk->sk_refcnt, 1);
}
void fastcall lock_sock(struct sock *sk)
{
might_sleep();
spin_lock_bh(&(sk->sk_lock.slock));
if (sk->sk_lock.owner)
__lock_sock(sk);
sk->sk_lock.owner = (void *)1;
spin_unlock_bh(&(sk->sk_lock.slock));
}
EXPORT_SYMBOL(lock_sock);
void fastcall release_sock(struct sock *sk)
{
spin_lock_bh(&(sk->sk_lock.slock));
if (sk->sk_backlog.tail)
__release_sock(sk);
sk->sk_lock.owner = NULL;
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)
{
if (!sock_flag(sk, SOCK_TIMESTAMP))
sock_enable_timestamp(sk);
if (sk->sk_stamp.tv_sec == -1)
return -ENOENT;
if (sk->sk_stamp.tv_sec == 0)
do_gettimeofday(&sk->sk_stamp);
return copy_to_user(userstamp, &sk->sk_stamp, sizeof(struct timeval)) ?
-EFAULT : 0;
}
EXPORT_SYMBOL(sock_get_timestamp);
void sock_enable_timestamp(struct sock *sk)
{
if (!sock_flag(sk, SOCK_TIMESTAMP)) {
sock_set_flag(sk, SOCK_TIMESTAMP);
net_enable_timestamp();
}
}
EXPORT_SYMBOL(sock_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);
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);
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);
#ifdef INET_REFCNT_DEBUG
if (atomic_read(&sk->sk_refcnt) != 1)
printk(KERN_DEBUG "Destruction of the socket %p delayed, c=%d\n",
sk, atomic_read(&sk->sk_refcnt));
#endif
sock_put(sk);
}
EXPORT_SYMBOL(sk_common_release);
int sk_alloc_slab(struct proto *prot, char *name)
{
prot->slab = kmem_cache_create(name,
prot->slab_obj_size, 0,
SLAB_HWCACHE_ALIGN, NULL, NULL);
return prot->slab != NULL ? 0 : -ENOBUFS;
}
EXPORT_SYMBOL(sk_alloc_slab);
void sk_free_slab(struct proto *prot)
{
if (prot->slab != NULL) {
kmem_cache_destroy(prot->slab);
prot->slab = NULL;
}
}
EXPORT_SYMBOL(sk_free_slab);
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);
#ifdef CONFIG_SYSCTL
EXPORT_SYMBOL(sysctl_optmem_max);
EXPORT_SYMBOL(sysctl_rmem_max);
EXPORT_SYMBOL(sysctl_wmem_max);
#endif
