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linux/net/core/sock.c
Eric Dumazet 30e6c9fa93 net: devnet_rename_seq should be a seqcount 
Using a seqlock for devnet_rename_seq is not a good idea,
as device_rename() can sleep.

As we hold RTNL, we dont need a protection for writers,
and only need a seqcount so that readers can catch a change done
by a writer.

Bug added in commit c91f6df2db (sockopt: Change getsockopt() of
SO_BINDTODEVICE to return an interface name)

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-21 13:14:01 -08:00

2846 lines
70 KiB
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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.
*
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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 <linux/user_namespace.h>
#include <linux/static_key.h>
#include <linux/memcontrol.h>
#include <linux/prefetch.h>
#include <asm/uaccess.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 <linux/net_tstamp.h>
#include <net/xfrm.h>
#include <linux/ipsec.h>
#include <net/cls_cgroup.h>
#include <net/netprio_cgroup.h>
#include <linux/filter.h>
#include <trace/events/sock.h>
#ifdef CONFIG_INET
#include <net/tcp.h>
#endif
static DEFINE_MUTEX(proto_list_mutex);
static LIST_HEAD(proto_list);
#ifdef CONFIG_MEMCG_KMEM
int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
struct proto *proto;
int ret = 0;
mutex_lock(&proto_list_mutex);
list_for_each_entry(proto, &proto_list, node) {
if (proto->init_cgroup) {
ret = proto->init_cgroup(memcg, ss);
if (ret)
goto out;
}
}
mutex_unlock(&proto_list_mutex);
return ret;
out:
list_for_each_entry_continue_reverse(proto, &proto_list, node)
if (proto->destroy_cgroup)
proto->destroy_cgroup(memcg);
mutex_unlock(&proto_list_mutex);
return ret;
}
void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
{
struct proto *proto;
mutex_lock(&proto_list_mutex);
list_for_each_entry_reverse(proto, &proto_list, node)
if (proto->destroy_cgroup)
proto->destroy_cgroup(memcg);
mutex_unlock(&proto_list_mutex);
}
#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];
struct static_key memcg_socket_limit_enabled;
EXPORT_SYMBOL(memcg_socket_limit_enabled);
/*
* 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 *const 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-AF_RDS" , "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_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG" ,
"sk_lock-AF_NFC" , "sk_lock-AF_MAX"
};
static const char *const 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-AF_RDS" , "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_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG" ,
"slock-AF_NFC" , "slock-AF_MAX"
};
static const char *const 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-AF_RDS" , "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_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG" ,
"clock-AF_NFC" , "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 SKB_TRUESIZE(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;
EXPORT_SYMBOL(sysctl_wmem_max);
__u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
EXPORT_SYMBOL(sysctl_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 ancillary data plus some space */
int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
EXPORT_SYMBOL(sysctl_optmem_max);
struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
EXPORT_SYMBOL_GPL(memalloc_socks);
/**
* sk_set_memalloc - sets %SOCK_MEMALLOC
* @sk: socket to set it on
*
* Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
* It's the responsibility of the admin to adjust min_free_kbytes
* to meet the requirements
*/
void sk_set_memalloc(struct sock *sk)
{
sock_set_flag(sk, SOCK_MEMALLOC);
sk->sk_allocation |= __GFP_MEMALLOC;
static_key_slow_inc(&memalloc_socks);
}
EXPORT_SYMBOL_GPL(sk_set_memalloc);
void sk_clear_memalloc(struct sock *sk)
{
sock_reset_flag(sk, SOCK_MEMALLOC);
sk->sk_allocation &= ~__GFP_MEMALLOC;
static_key_slow_dec(&memalloc_socks);
/*
* SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
* progress of swapping. However, if SOCK_MEMALLOC is cleared while
* it has rmem allocations there is a risk that the user of the
* socket cannot make forward progress due to exceeding the rmem
* limits. By rights, sk_clear_memalloc() should only be called
* on sockets being torn down but warn and reset the accounting if
* that assumption breaks.
*/
if (WARN_ON(sk->sk_forward_alloc))
sk_mem_reclaim(sk);
}
EXPORT_SYMBOL_GPL(sk_clear_memalloc);
int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
int ret;
unsigned long pflags = current->flags;
/* these should have been dropped before queueing */
BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
current->flags |= PF_MEMALLOC;
ret = sk->sk_backlog_rcv(sk, skb);
tsk_restore_flags(current, pflags, PF_MEMALLOC);
return ret;
}
EXPORT_SYMBOL(__sk_backlog_rcv);
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++;
pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
__func__, 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);
pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
warncomm, name);
warned++;
}
}
#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
{
if (sk->sk_flags & flags) {
sk->sk_flags &= ~flags;
if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
net_disable_timestamp();
}
}
int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
int err;
int skb_len;
unsigned long flags;
struct sk_buff_head *list = &sk->sk_receive_queue;
if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
atomic_inc(&sk->sk_drops);
trace_sock_rcvqueue_full(sk, skb);
return -ENOMEM;
}
err = sk_filter(sk, skb);
if (err)
return err;
if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
atomic_inc(&sk->sk_drops);
return -ENOBUFS;
}
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;
/* we escape from rcu protected region, make sure we dont leak
* a norefcounted dst
*/
skb_dst_force(skb);
spin_lock_irqsave(&list->lock, flags);
skb->dropcount = atomic_read(&sk->sk_drops);
__skb_queue_tail(list, skb);
spin_unlock_irqrestore(&list->lock, flags);
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_data_ready(sk, skb_len);
return 0;
}
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 (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) {
atomic_inc(&sk->sk_drops);
goto discard_and_relse;
}
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 if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
bh_unlock_sock(sk);
atomic_inc(&sk->sk_drops);
goto discard_and_relse;
}
bh_unlock_sock(sk);
out:
sock_put(sk);
return rc;
discard_and_relse:
kfree_skb(skb);
goto out;
}
EXPORT_SYMBOL(sk_receive_skb);
void sk_reset_txq(struct sock *sk)
{
sk_tx_queue_clear(sk);
}
EXPORT_SYMBOL(sk_reset_txq);
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_tx_queue_clear(sk);
RCU_INIT_POINTER(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_setbindtodevice(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 (!ns_capable(net->user_ns, 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;
index = 0;
if (devname[0] != '\0') {
struct net_device *dev;
rcu_read_lock();
dev = dev_get_by_name_rcu(net, devname);
if (dev)
index = dev->ifindex;
rcu_read_unlock();
ret = -ENODEV;
if (!dev)
goto out;
}
lock_sock(sk);
sk->sk_bound_dev_if = index;
sk_dst_reset(sk);
release_sock(sk);
ret = 0;
out:
#endif
return ret;
}
static int sock_getbindtodevice(struct sock *sk, char __user *optval,
int __user *optlen, int len)
{
int ret = -ENOPROTOOPT;
#ifdef CONFIG_NETDEVICES
struct net *net = sock_net(sk);
struct net_device *dev;
char devname[IFNAMSIZ];
unsigned seq;
if (sk->sk_bound_dev_if == 0) {
len = 0;
goto zero;
}
ret = -EINVAL;
if (len < IFNAMSIZ)
goto out;
retry:
seq = read_seqcount_begin(&devnet_rename_seq);
rcu_read_lock();
dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
ret = -ENODEV;
if (!dev) {
rcu_read_unlock();
goto out;
}
strcpy(devname, dev->name);
rcu_read_unlock();
if (read_seqcount_retry(&devnet_rename_seq, seq))
goto retry;
len = strlen(devname) + 1;
ret = -EFAULT;
if (copy_to_user(optval, devname, len))
goto out;
zero:
ret = -EFAULT;
if (put_user(len, optlen))
goto out;
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, unsigned 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_setbindtodevice(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 ? SK_CAN_REUSE : SK_NO_REUSE);
break;
case SO_TYPE:
case SO_PROTOCOL:
case SO_DOMAIN:
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
*/
val = min_t(u32, val, sysctl_wmem_max);
set_sndbuf:
sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
/* 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
*/
val = min_t(u32, 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.
*/
sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
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 &&
sk->sk_type == SOCK_STREAM)
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) ||
ns_capable(sock_net(sk)->user_ns, 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, SOCK_TIMESTAMP);
} else {
sock_reset_flag(sk, SOCK_RCVTSTAMP);
sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
}
break;
case SO_TIMESTAMPING:
if (val & ~SOF_TIMESTAMPING_MASK) {
ret = -EINVAL;
break;
}
sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
val & SOF_TIMESTAMPING_TX_HARDWARE);
sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
val & SOF_TIMESTAMPING_TX_SOFTWARE);
sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
val & SOF_TIMESTAMPING_RX_HARDWARE);
if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
sock_enable_timestamp(sk,
SOCK_TIMESTAMPING_RX_SOFTWARE);
else
sock_disable_timestamp(sk,
(1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
val & SOF_TIMESTAMPING_SOFTWARE);
sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
val & SOF_TIMESTAMPING_SYS_HARDWARE);
sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
val & SOF_TIMESTAMPING_RAW_HARDWARE);
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 (!ns_capable(sock_net(sk)->user_ns, 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) */
case SO_RXQ_OVFL:
sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
break;
case SO_WIFI_STATUS:
sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
break;
case SO_PEEK_OFF:
if (sock->ops->set_peek_off)
sock->ops->set_peek_off(sk, val);
else
ret = -EOPNOTSUPP;
break;
case SO_NOFCS:
sock_valbool_flag(sk, SOCK_NOFCS, valbool);
break;
default:
ret = -ENOPROTOOPT;
break;
}
release_sock(sk);
return ret;
}
EXPORT_SYMBOL(sock_setsockopt);
void cred_to_ucred(struct pid *pid, const struct cred *cred,
struct ucred *ucred)
{
ucred->pid = pid_vnr(pid);
ucred->uid = ucred->gid = -1;
if (cred) {
struct user_namespace *current_ns = current_user_ns();
ucred->uid = from_kuid_munged(current_ns, cred->euid);
ucred->gid = from_kgid_munged(current_ns, cred->egid);
}
}
EXPORT_SYMBOL_GPL(cred_to_ucred);
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;
int lv = sizeof(int);
int len;
if (get_user(len, optlen))
return -EFAULT;
if (len < 0)
return -EINVAL;
memset(&v, 0, sizeof(v));
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_PROTOCOL:
v.val = sk->sk_protocol;
break;
case SO_DOMAIN:
v.val = sk->sk_family;
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_TIMESTAMPING:
v.val = 0;
if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
v.val |= SOF_TIMESTAMPING_SOFTWARE;
if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
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);
break;
case SO_PEERCRED:
{
struct ucred peercred;
if (len > sizeof(peercred))
len = sizeof(peercred);
cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
if (copy_to_user(optval, &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);
break;
case SO_PEERSEC:
return security_socket_getpeersec_stream(sock, optval, optlen, len);
case SO_MARK:
v.val = sk->sk_mark;
break;
case SO_RXQ_OVFL:
v.val = sock_flag(sk, SOCK_RXQ_OVFL);
break;
case SO_WIFI_STATUS:
v.val = sock_flag(sk, SOCK_WIFI_STATUS);
break;
case SO_PEEK_OFF:
if (!sock->ops->set_peek_off)
return -EOPNOTSUPP;
v.val = sk->sk_peek_off;
break;
case SO_NOFCS:
v.val = sock_flag(sk, SOCK_NOFCS);
break;
case SO_BINDTODEVICE:
return sock_getbindtodevice(sk, optval, optlen, len);
case SO_GET_FILTER:
len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
if (len < 0)
return len;
goto lenout;
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);
}
/*
* Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
* even temporarly, because of RCU lookups. sk_node should also be left as is.
* We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
*/
static void sock_copy(struct sock *nsk, const struct sock *osk)
{
#ifdef CONFIG_SECURITY_NETWORK
void *sptr = nsk->sk_security;
#endif
memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
#ifdef CONFIG_SECURITY_NETWORK
nsk->sk_security = sptr;
security_sk_clone(osk, nsk);
#endif
}
/*
* caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
* un-modified. Special care is taken when initializing object to zero.
*/
static inline void sk_prot_clear_nulls(struct sock *sk, int size)
{
if (offsetof(struct sock, sk_node.next) != 0)
memset(sk, 0, offsetof(struct sock, sk_node.next));
memset(&sk->sk_node.pprev, 0,
size - offsetof(struct sock, sk_node.pprev));
}
void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
{
unsigned long nulls1, nulls2;
nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
if (nulls1 > nulls2)
swap(nulls1, nulls2);
if (nulls1 != 0)
memset((char *)sk, 0, nulls1);
memset((char *)sk + nulls1 + sizeof(void *), 0,
nulls2 - nulls1 - sizeof(void *));
memset((char *)sk + nulls2 + sizeof(void *), 0,
size - nulls2 - sizeof(void *));
}
EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
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 & ~__GFP_ZERO);
if (!sk)
return sk;
if (priority & __GFP_ZERO) {
if (prot->clear_sk)
prot->clear_sk(sk, prot->obj_size);
else
sk_prot_clear_nulls(sk, prot->obj_size);
}
} else
sk = kmalloc(prot->obj_size, priority);
if (sk != NULL) {
kmemcheck_annotate_bitfield(sk, flags);
if (security_sk_alloc(sk, family, priority))
goto out_free;
if (!try_module_get(prot->owner))
goto out_free_sec;
sk_tx_queue_clear(sk);
}
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);
}
#ifdef CONFIG_CGROUPS
#if IS_ENABLED(CONFIG_NET_CLS_CGROUP)
void sock_update_classid(struct sock *sk, struct task_struct *task)
{
u32 classid;
classid = task_cls_classid(task);
if (classid != sk->sk_classid)
sk->sk_classid = classid;
}
EXPORT_SYMBOL(sock_update_classid);
#endif
#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
{
if (in_interrupt())
return;
sk->sk_cgrp_prioidx = task_netprioidx(task);
}
EXPORT_SYMBOL_GPL(sock_update_netprioidx);
#endif
#endif
/**
* 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));
atomic_set(&sk->sk_wmem_alloc, 1);
sock_update_classid(sk, current);
sock_update_netprioidx(sk, current);
}
return sk;
}
EXPORT_SYMBOL(sk_alloc);
static void __sk_free(struct sock *sk)
{
struct sk_filter *filter;
if (sk->sk_destruct)
sk->sk_destruct(sk);
filter = rcu_dereference_check(sk->sk_filter,
atomic_read(&sk->sk_wmem_alloc) == 0);
if (filter) {
sk_filter_uncharge(sk, filter);
RCU_INIT_POINTER(sk->sk_filter, NULL);
}
sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
if (atomic_read(&sk->sk_omem_alloc))
pr_debug("%s: optmem leakage (%d bytes) detected\n",
__func__, atomic_read(&sk->sk_omem_alloc));
if (sk->sk_peer_cred)
put_cred(sk->sk_peer_cred);
put_pid(sk->sk_peer_pid);
put_net(sock_net(sk));
sk_prot_free(sk->sk_prot_creator, sk);
}
void sk_free(struct sock *sk)
{
/*
* We subtract one from sk_wmem_alloc and can know if
* some packets are still in some tx queue.
* If not null, sock_wfree() will call __sk_free(sk) later
*/
if (atomic_dec_and_test(&sk->sk_wmem_alloc))
__sk_free(sk);
}
EXPORT_SYMBOL(sk_free);
/*
* Last sock_put should drop reference to sk->sk_net. It has already
* been dropped in sk_change_net. Taking reference to stopping namespace
* is not an option.
* Take reference 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);
static void sk_update_clone(const struct sock *sk, struct sock *newsk)
{
if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
sock_update_memcg(newsk);
}
/**
* sk_clone_lock - clone a socket, and lock its clone
* @sk: the socket to clone
* @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
*
* Caller must unlock socket even in error path (bh_unlock_sock(newsk))
*/
struct sock *sk_clone_lock(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;
newsk->sk_backlog.len = 0;
atomic_set(&newsk->sk_rmem_alloc, 0);
/*
* sk_wmem_alloc set to one (see sk_free() and sock_wfree())
*/
atomic_set(&newsk->sk_wmem_alloc, 1);
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
spin_lock_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 = rcu_dereference_protected(newsk->sk_filter, 1);
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;
bh_unlock_sock(newsk);
sk_free(newsk);
newsk = NULL;
goto out;
}
newsk->sk_err = 0;
newsk->sk_priority = 0;
/*
* Before updating sk_refcnt, we must commit prior changes to memory
* (Documentation/RCU/rculist_nulls.txt for details)
*/
smp_wmb();
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_wq = NULL;
sk_update_clone(sk, newsk);
if (newsk->sk_prot->sockets_allocated)
sk_sockets_allocated_inc(newsk);
if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
net_enable_timestamp();
}
out:
return newsk;
}
EXPORT_SYMBOL_GPL(sk_clone_lock);
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;
sk->sk_route_caps &= ~sk->sk_route_nocaps;
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;
sk->sk_gso_max_segs = dst->dev->gso_max_segs;
}
}
}
EXPORT_SYMBOL_GPL(sk_setup_caps);
/*
* 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;
unsigned int len = skb->truesize;
if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
/*
* Keep a reference on sk_wmem_alloc, this will be released
* after sk_write_space() call
*/
atomic_sub(len - 1, &sk->sk_wmem_alloc);
sk->sk_write_space(sk);
len = 1;
}
/*
* if sk_wmem_alloc reaches 0, we must finish what sk_free()
* could not do because of in-flight packets
*/
if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
__sk_free(sk);
}
EXPORT_SYMBOL(sock_wfree);
/*
* Read buffer destructor automatically called from kfree_skb.
*/
void sock_rfree(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
unsigned int len = skb->truesize;
atomic_sub(len, &sk->sk_rmem_alloc);
sk_mem_uncharge(sk, len);
}
EXPORT_SYMBOL(sock_rfree);
void sock_edemux(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
#ifdef CONFIG_INET
if (sk->sk_state == TCP_TIME_WAIT)
inet_twsk_put(inet_twsk(sk));
else
#endif
sock_put(sk);
}
EXPORT_SYMBOL(sock_edemux);
kuid_t sock_i_uid(struct sock *sk)
{
kuid_t uid;
read_lock_bh(&sk->sk_callback_lock);
uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
read_unlock_bh(&sk->sk_callback_lock);
return uid;
}
EXPORT_SYMBOL(sock_i_uid);
unsigned long sock_i_ino(struct sock *sk)
{
unsigned long ino;
read_lock_bh(&sk->sk_callback_lock);
ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
read_unlock_bh(&sk->sk_callback_lock);
return ino;
}
EXPORT_SYMBOL(sock_i_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;
}
EXPORT_SYMBOL(sock_wmalloc);
/*
* 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 int)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;
}
EXPORT_SYMBOL(sock_kmalloc);
/*
* 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);
}
EXPORT_SYMBOL(sock_kfree_s);
/* 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_sleep(sk), &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_sleep(sk), &wait);
return timeo;
}
/*
* Generic send/receive buffer handlers
*/
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;
int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
err = -EMSGSIZE;
if (npages > MAX_SKB_FRAGS)
goto failure;
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 i;
/* No pages, we're done... */
if (!data_len)
break;
skb->truesize += data_len;
skb_shinfo(skb)->nr_frags = npages;
for (i = 0; i < npages; i++) {
struct page *page;
page = alloc_pages(sk->sk_allocation, 0);
if (!page) {
err = -ENOBUFS;
skb_shinfo(skb)->nr_frags = i;
kfree_skb(skb);
goto failure;
}
__skb_fill_page_desc(skb, i,
page, 0,
(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;
}
EXPORT_SYMBOL(sock_alloc_send_pskb);
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);
}
EXPORT_SYMBOL(sock_alloc_send_skb);
/* On 32bit arches, an skb frag is limited to 2^15 */
#define SKB_FRAG_PAGE_ORDER get_order(32768)
bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
{
int order;
if (pfrag->page) {
if (atomic_read(&pfrag->page->_count) == 1) {
pfrag->offset = 0;
return true;
}
if (pfrag->offset < pfrag->size)
return true;
put_page(pfrag->page);
}
/* We restrict high order allocations to users that can afford to wait */
order = (sk->sk_allocation & __GFP_WAIT) ? SKB_FRAG_PAGE_ORDER : 0;
do {
gfp_t gfp = sk->sk_allocation;
if (order)
gfp |= __GFP_COMP | __GFP_NOWARN;
pfrag->page = alloc_pages(gfp, order);
if (likely(pfrag->page)) {
pfrag->offset = 0;
pfrag->size = PAGE_SIZE << order;
return true;
}
} while (--order >= 0);
sk_enter_memory_pressure(sk);
sk_stream_moderate_sndbuf(sk);
return false;
}
EXPORT_SYMBOL(sk_page_frag_refill);
static void __lock_sock(struct sock *sk)
__releases(&sk->sk_lock.slock)
__acquires(&sk->sk_lock.slock)
{
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)
__releases(&sk->sk_lock.slock)
__acquires(&sk->sk_lock.slock)
{
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;
prefetch(next);
WARN_ON_ONCE(skb_dst_is_noref(skb));
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);
/*
* Doing the zeroing here guarantee we can not loop forever
* while a wild producer attempts to flood us.
*/
sk->sk_backlog.len = 0;
}
/**
* 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_sleep(sk), &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_sleep(sk), &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);
long allocated;
int parent_status = UNDER_LIMIT;
sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
allocated = sk_memory_allocated_add(sk, amt, &parent_status);
/* Under limit. */
if (parent_status == UNDER_LIMIT &&
allocated <= sk_prot_mem_limits(sk, 0)) {
sk_leave_memory_pressure(sk);
return 1;
}
/* Under pressure. (we or our parents) */
if ((parent_status > SOFT_LIMIT) ||
allocated > sk_prot_mem_limits(sk, 1))
sk_enter_memory_pressure(sk);
/* Over hard limit (we or our parents) */
if ((parent_status == OVER_LIMIT) ||
(allocated > sk_prot_mem_limits(sk, 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 (sk_has_memory_pressure(sk)) {
int alloc;
if (!sk_under_memory_pressure(sk))
return 1;
alloc = sk_sockets_allocated_read_positive(sk);
if (sk_prot_mem_limits(sk, 2) > alloc *
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;
}
trace_sock_exceed_buf_limit(sk, prot, allocated);
/* Alas. Undo changes. */
sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
sk_memory_allocated_sub(sk, amt);
return 0;
}
EXPORT_SYMBOL(__sk_mem_schedule);
/**
* __sk_reclaim - reclaim memory_allocated
* @sk: socket
*/
void __sk_mem_reclaim(struct sock *sk)
{
sk_memory_allocated_sub(sk,
sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
if (sk_under_memory_pressure(sk) &&
(sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
sk_leave_memory_pressure(sk);
}
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;
}
EXPORT_SYMBOL(sock_no_bind);
int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
int len, int flags)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_connect);
int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_socketpair);
int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_accept);
int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
int *len, int peer)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_getname);
unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
{
return 0;
}
EXPORT_SYMBOL(sock_no_poll);
int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_ioctl);
int sock_no_listen(struct socket *sock, int backlog)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_listen);
int sock_no_shutdown(struct socket *sock, int how)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_shutdown);
int sock_no_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, unsigned int optlen)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_setsockopt);
int sock_no_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_getsockopt);
int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
size_t len)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_sendmsg);
int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
size_t len, int flags)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL(sock_no_recvmsg);
int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
{
/* Mirror missing mmap method error code */
return -ENODEV;
}
EXPORT_SYMBOL(sock_no_mmap);
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;
}
EXPORT_SYMBOL(sock_no_sendpage);
/*
* Default Socket Callbacks
*/
static void sock_def_wakeup(struct sock *sk)
{
struct socket_wq *wq;
rcu_read_lock();
wq = rcu_dereference(sk->sk_wq);
if (wq_has_sleeper(wq))
wake_up_interruptible_all(&wq->wait);
rcu_read_unlock();
}
static void sock_def_error_report(struct sock *sk)
{
struct socket_wq *wq;
rcu_read_lock();
wq = rcu_dereference(sk->sk_wq);
if (wq_has_sleeper(wq))
wake_up_interruptible_poll(&wq->wait, POLLERR);
sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
rcu_read_unlock();
}
static void sock_def_readable(struct sock *sk, int len)
{
struct socket_wq *wq;
rcu_read_lock();
wq = rcu_dereference(sk->sk_wq);
if (wq_has_sleeper(wq))
wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
POLLRDNORM | POLLRDBAND);
sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
rcu_read_unlock();
}
static void sock_def_write_space(struct sock *sk)
{
struct socket_wq *wq;
rcu_read_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) {
wq = rcu_dereference(sk->sk_wq);
if (wq_has_sleeper(wq))
wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
POLLWRNORM | POLLWRBAND);
/* Should agree with poll, otherwise some programs break */
if (sock_writeable(sk))
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
rcu_read_unlock();
}
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);
}
EXPORT_SYMBOL(sk_send_sigurg);
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_wq = sock->wq;
sock->sk = sk;
} else
sk->sk_wq = NULL;
spin_lock_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_frag.page = NULL;
sk->sk_frag.offset = 0;
sk->sk_peek_off = -1;
sk->sk_peer_pid = NULL;
sk->sk_peer_cred = NULL;
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);
/*
* Before updating sk_refcnt, we must commit prior changes to memory
* (Documentation/RCU/rculist_nulls.txt for details)
*/
smp_wmb();
atomic_set(&sk->sk_refcnt, 1);
atomic_set(&sk->sk_drops, 0);
}
EXPORT_SYMBOL(sock_init_data);
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);
if (sk->sk_prot->release_cb)
sk->sk_prot->release_cb(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);
/**
* lock_sock_fast - fast version of lock_sock
* @sk: socket
*
* This version should be used for very small section, where process wont block
* return false if fast path is taken
* sk_lock.slock locked, owned = 0, BH disabled
* return true if slow path is taken
* sk_lock.slock unlocked, owned = 1, BH enabled
*/
bool lock_sock_fast(struct sock *sk)
{
might_sleep();
spin_lock_bh(&sk->sk_lock.slock);
if (!sk->sk_lock.owned)
/*
* Note : We must disable BH
*/
return false;
__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, 0, 0, _RET_IP_);
local_bh_enable();
return true;
}
EXPORT_SYMBOL(lock_sock_fast);
int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
{
struct timeval tv;
if (!sock_flag(sk, SOCK_TIMESTAMP))
sock_enable_timestamp(sk, SOCK_TIMESTAMP);
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, SOCK_TIMESTAMP);
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, int flag)
{
if (!sock_flag(sk, flag)) {
unsigned long previous_flags = sk->sk_flags;
sock_set_flag(sk, flag);
/*
* we just set one of the two flags which require net
* time stamping, but time stamping might have been on
* already because of the other one
*/
if (!(previous_flags & SK_FLAGS_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, unsigned 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, unsigned 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);
if (sk->sk_frag.page) {
put_page(sk->sk_frag.page);
sk->sk_frag.page = NULL;
}
sock_put(sk);
}
EXPORT_SYMBOL(sk_common_release);
#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)
{
__this_cpu_add(net->core.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_ptr(net->core.inuse, cpu)->val[idx];
return res >= 0 ? res : 0;
}
EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
static int __net_init sock_inuse_init_net(struct net *net)
{
net->core.inuse = alloc_percpu(struct prot_inuse);
return net->core.inuse ? 0 : -ENOMEM;
}
static void __net_exit 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)
{
__this_cpu_add(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)) {
pr_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 | prot->slab_flags,
NULL);
if (prot->slab == NULL) {
pr_crit("%s: Can't create sock SLAB cache!\n",
prot->name);
goto out;
}
if (prot->rsk_prot != NULL) {
prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
if (prot->rsk_prot->slab_name == NULL)
goto out_free_sock_slab;
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) {
pr_crit("%s: Can't create request sock SLAB cache!\n",
prot->name);
goto out_free_request_sock_slab_name;
}
}
if (prot->twsk_prot != NULL) {
prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
if (prot->twsk_prot->twsk_slab_name == NULL)
goto out_free_request_sock_slab;
prot->twsk_prot->twsk_slab =
kmem_cache_create(prot->twsk_prot->twsk_slab_name,
prot->twsk_prot->twsk_obj_size,
0,
SLAB_HWCACHE_ALIGN |
prot->slab_flags,
NULL);
if (prot->twsk_prot->twsk_slab == NULL)
goto out_free_timewait_sock_slab_name;
}
}
mutex_lock(&proto_list_mutex);
list_add(&prot->node, &proto_list);
assign_proto_idx(prot);
mutex_unlock(&proto_list_mutex);
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:
if (prot->rsk_prot)
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)
{
mutex_lock(&proto_list_mutex);
release_proto_idx(prot);
list_del(&prot->node);
mutex_unlock(&proto_list_mutex);
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_mutex)
{
mutex_lock(&proto_list_mutex);
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_mutex)
{
mutex_unlock(&proto_list_mutex);
}
static char proto_method_implemented(const void *method)
{
return method == NULL ? 'n' : 'y';
}
static long sock_prot_memory_allocated(struct proto *proto)
{
return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
}
static char *sock_prot_memory_pressure(struct proto *proto)
{
return proto->memory_pressure != NULL ?
proto_memory_pressure(proto) ? "yes" : "no" : "NI";
}
static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
{
seq_printf(seq, "%-9s %4u %6d %6ld %-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,
sock_prot_inuse_get(seq_file_net(seq), proto),
sock_prot_memory_allocated(proto),
sock_prot_memory_pressure(proto),
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_net(inode, file, &proto_seq_ops,
sizeof(struct seq_net_private));
}
static const struct file_operations proto_seq_fops = {
.owner = THIS_MODULE,
.open = proto_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
static __net_init int proto_init_net(struct net *net)
{
if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
return -ENOMEM;
return 0;
}
static __net_exit void proto_exit_net(struct net *net)
{
proc_net_remove(net, "protocols");
}
static __net_initdata struct pernet_operations proto_net_ops = {
.init = proto_init_net,
.exit = proto_exit_net,
};
static int __init proto_init(void)
{
return register_pernet_subsys(&proto_net_ops);
}
subsys_initcall(proto_init);
#endif /* PROC_FS */
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