linux/net/core/sock.c

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/*
* 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
* 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/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 <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 if (valbool)
sock_set_flag(sk, SOCK_DBG);
else
sock_reset_flag(sk, SOCK_DBG);
break;
case SO_REUSEADDR:
sk->sk_reuse = valbool;
break;
case SO_TYPE:
case SO_ERROR:
ret = -ENOPROTOOPT;
break;
case SO_DONTROUTE:
if (valbool)
sock_set_flag(sk, SOCK_LOCALROUTE);
else
sock_reset_flag(sk, SOCK_LOCALROUTE);
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:
if (valbool)
set_bit(SOCK_PASSCRED, &sock->flags);
else
clear_bit(SOCK_PASSCRED, &sock->flags);
break;
case SO_TIMESTAMP:
if (valbool) {
sock_set_flag(sk, SOCK_RCVTSTAMP);
sock_enable_timestamp(sk);
} else
sock_reset_flag(sk, SOCK_RCVTSTAMP);
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 = 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);
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_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;
}
/**
* sk_alloc - All socket objects are allocated here
[PATCH] DocBook: changes and extensions to the kernel documentation I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed <pid> to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:59:25 +00:00
* @family: protocol family
* @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
* @prot: struct proto associated with this new sock instance
* @zero_it: if we should zero the newly allocated sock
*/
struct sock *sk_alloc(int family, int priority, struct proto *prot, int zero_it)
{
struct sock *sk = NULL;
kmem_cache_t *slab = prot->slab;
if (slab != NULL)
sk = kmem_cache_alloc(slab, priority);
else
sk = kmalloc(prot->obj_size, priority);
if (sk) {
if (zero_it) {
memset(sk, 0, prot->obj_size);
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);
}
if (security_sk_alloc(sk, family, priority)) {
if (slab != NULL)
kmem_cache_free(slab, sk);
else
kfree(sk);
sk = NULL;
} else
__module_get(prot->owner);
}
return sk;
}
void sk_free(struct sock *sk)
{
struct sk_filter *filter;
struct module *owner = sk->sk_prot_creator->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);
if (sk->sk_prot_creator->slab != NULL)
kmem_cache_free(sk->sk_prot_creator->slab, sk);
else
kfree(sk);
module_put(owner);
}
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;
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
[PATCH] DocBook: changes and extensions to the kernel documentation I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed <pid> to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:59:25 +00:00
* @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_socket = 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);
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.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);
static DEFINE_RWLOCK(proto_list_lock);
static LIST_HEAD(proto_list);
int proto_register(struct proto *prot, int alloc_slab)
{
int rc = -ENOBUFS;
if (alloc_slab) {
prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
SLAB_HWCACHE_ALIGN, NULL, NULL);
if (prot->slab == NULL) {
printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
prot->name);
goto out;
}
}
write_lock(&proto_list_lock);
list_add(&prot->node, &proto_list);
write_unlock(&proto_list_lock);
rc = 0;
out:
return rc;
}
EXPORT_SYMBOL(proto_register);
void proto_unregister(struct proto *prot)
{
write_lock(&proto_list_lock);
if (prot->slab != NULL) {
kmem_cache_destroy(prot->slab);
prot->slab = NULL;
}
list_del(&prot->node);
write_unlock(&proto_list_lock);
}
EXPORT_SYMBOL(proto_unregister);
#ifdef CONFIG_PROC_FS
static inline struct proto *__proto_head(void)
{
return list_entry(proto_list.next, struct proto, node);
}
static inline struct proto *proto_head(void)
{
return list_empty(&proto_list) ? NULL : __proto_head();
}
static inline struct proto *proto_next(struct proto *proto)
{
return proto->node.next == &proto_list ? NULL :
list_entry(proto->node.next, struct proto, node);
}
static inline struct proto *proto_get_idx(loff_t pos)
{
struct proto *proto;
loff_t i = 0;
list_for_each_entry(proto, &proto_list, node)
if (i++ == pos)
goto out;
proto = NULL;
out:
return proto;
}
static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
{
read_lock(&proto_list_lock);
return *pos ? proto_get_idx(*pos - 1) : SEQ_START_TOKEN;
}
static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
++*pos;
return v == SEQ_START_TOKEN ? proto_head() : proto_next(v);
}
static void proto_seq_stop(struct seq_file *seq, void *v)
{
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 == SEQ_START_TOKEN)
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, v);
return 0;
}
static 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 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("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);
#ifdef CONFIG_SYSCTL
EXPORT_SYMBOL(sysctl_optmem_max);
EXPORT_SYMBOL(sysctl_rmem_max);
EXPORT_SYMBOL(sysctl_wmem_max);
#endif