// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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:
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <asm/unaligned.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/errqueue.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/sched/mm.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 <linux/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/sock_diag.h>

#include <linux/filter.h>
#include <net/sock_reuseport.h>
#include <net/bpf_sk_storage.h>

#include <trace/events/sock.h>

#include <net/tcp.h>
#include <net/busy_poll.h>

static DEFINE_MUTEX(proto_list_mutex);
static LIST_HEAD(proto_list);

static void sock_inuse_add(struct net *net, int val);

/**
 * sk_ns_capable - General socket capability test
 * @sk: Socket to use a capability on or through
 * @user_ns: The user namespace of the capability to use
 * @cap: The capability to use
 *
 * Test to see if the opener of the socket had when the socket was
 * created and the current process has the capability @cap in the user
 * namespace @user_ns.
 */
bool sk_ns_capable(const struct sock *sk,
		   struct user_namespace *user_ns, int cap)
{
	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
		ns_capable(user_ns, cap);
}
EXPORT_SYMBOL(sk_ns_capable);

/**
 * sk_capable - Socket global capability test
 * @sk: Socket to use a capability on or through
 * @cap: The global capability to use
 *
 * Test to see if the opener of the socket had when the socket was
 * created and the current process has the capability @cap in all user
 * namespaces.
 */
bool sk_capable(const struct sock *sk, int cap)
{
	return sk_ns_capable(sk, &init_user_ns, cap);
}
EXPORT_SYMBOL(sk_capable);

/**
 * sk_net_capable - Network namespace socket capability test
 * @sk: Socket to use a capability on or through
 * @cap: The capability to use
 *
 * Test to see if the opener of the socket had when the socket was created
 * and the current process has the capability @cap over the network namespace
 * the socket is a member of.
 */
bool sk_net_capable(const struct sock *sk, int cap)
{
	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
}
EXPORT_SYMBOL(sk_net_capable);

/*
 * Each address family might have different locking rules, so we have
 * one slock key per address family and separate keys for internal and
 * userspace sockets.
 */
static struct lock_class_key af_family_keys[AF_MAX];
static struct lock_class_key af_family_kern_keys[AF_MAX];
static struct lock_class_key af_family_slock_keys[AF_MAX];
static struct lock_class_key af_family_kern_slock_keys[AF_MAX];

/*
 * Make lock validator output more readable. (we pre-construct these
 * strings build-time, so that runtime initialization of socket
 * locks is fast):
 */

#define _sock_locks(x)						  \
  x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
  x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
  x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
  x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
  x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
  x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
  x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
  x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
  x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
  x "27"       ,	x "28"          ,	x "AF_CAN"      , \
  x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
  x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
  x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
  x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
  x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
  x "AF_MAX"

static const char *const af_family_key_strings[AF_MAX+1] = {
	_sock_locks("sk_lock-")
};
static const char *const af_family_slock_key_strings[AF_MAX+1] = {
	_sock_locks("slock-")
};
static const char *const af_family_clock_key_strings[AF_MAX+1] = {
	_sock_locks("clock-")
};

static const char *const af_family_kern_key_strings[AF_MAX+1] = {
	_sock_locks("k-sk_lock-")
};
static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
	_sock_locks("k-slock-")
};
static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
	_sock_locks("k-clock-")
};
static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
	_sock_locks("rlock-")
};
static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
	_sock_locks("wlock-")
};
static const char *const af_family_elock_key_strings[AF_MAX+1] = {
	_sock_locks("elock-")
};

/*
 * sk_callback_lock and sk queues 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];
static struct lock_class_key af_rlock_keys[AF_MAX];
static struct lock_class_key af_wlock_keys[AF_MAX];
static struct lock_class_key af_elock_keys[AF_MAX];
static struct lock_class_key af_kern_callback_keys[AF_MAX];

/* 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);

int sysctl_tstamp_allow_data __read_mostly = 1;

DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
EXPORT_SYMBOL_GPL(memalloc_socks_key);

/**
 * 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_branch_inc(&memalloc_socks_key);
}
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_branch_dec(&memalloc_socks_key);

	/*
	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
	 * progress of swapping. SOCK_MEMALLOC may be cleared while
	 * it has rmem allocations due to the last swapfile being deactivated
	 * but there is a risk that the socket is unusable due to exceeding
	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
	 */
	sk_mem_reclaim(sk);
}
EXPORT_SYMBOL_GPL(sk_clear_memalloc);

int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
	int ret;
	unsigned int noreclaim_flag;

	/* these should have been dropped before queueing */
	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));

	noreclaim_flag = memalloc_noreclaim_save();
	ret = sk->sk_backlog_rcv(sk, skb);
	memalloc_noreclaim_restore(noreclaim_flag);

	return ret;
}
EXPORT_SYMBOL(__sk_backlog_rcv);

static int sock_get_timeout(long timeo, void *optval, bool old_timeval)
{
	struct __kernel_sock_timeval tv;

	if (timeo == MAX_SCHEDULE_TIMEOUT) {
		tv.tv_sec = 0;
		tv.tv_usec = 0;
	} else {
		tv.tv_sec = timeo / HZ;
		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
	}

	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
		*(struct old_timeval32 *)optval = tv32;
		return sizeof(tv32);
	}

	if (old_timeval) {
		struct __kernel_old_timeval old_tv;
		old_tv.tv_sec = tv.tv_sec;
		old_tv.tv_usec = tv.tv_usec;
		*(struct __kernel_old_timeval *)optval = old_tv;
		return sizeof(old_tv);
	}

	*(struct __kernel_sock_timeval *)optval = tv;
	return sizeof(tv);
}

static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen, bool old_timeval)
{
	struct __kernel_sock_timeval tv;

	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
		struct old_timeval32 tv32;

		if (optlen < sizeof(tv32))
			return -EINVAL;

		if (copy_from_user(&tv32, optval, sizeof(tv32)))
			return -EFAULT;
		tv.tv_sec = tv32.tv_sec;
		tv.tv_usec = tv32.tv_usec;
	} else if (old_timeval) {
		struct __kernel_old_timeval old_tv;

		if (optlen < sizeof(old_tv))
			return -EINVAL;
		if (copy_from_user(&old_tv, optval, sizeof(old_tv)))
			return -EFAULT;
		tv.tv_sec = old_tv.tv_sec;
		tv.tv_usec = old_tv.tv_usec;
	} else {
		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 + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / 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++;
	}
}

static bool sock_needs_netstamp(const struct sock *sk)
{
	switch (sk->sk_family) {
	case AF_UNSPEC:
	case AF_UNIX:
		return false;
	default:
		return true;
	}
}

static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
{
	if (sk->sk_flags & flags) {
		sk->sk_flags &= ~flags;
		if (sock_needs_netstamp(sk) &&
		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
			net_disable_timestamp();
	}
}


int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	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;
	}

	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
		atomic_inc(&sk->sk_drops);
		return -ENOBUFS;
	}

	skb->dev = NULL;
	skb_set_owner_r(skb, sk);

	/* we escape from rcu protected region, make sure we dont leak
	 * a norefcounted dst
	 */
	skb_dst_force(skb);

	spin_lock_irqsave(&list->lock, flags);
	sock_skb_set_dropcount(sk, skb);
	__skb_queue_tail(list, skb);
	spin_unlock_irqrestore(&list->lock, flags);

	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_data_ready(sk);
	return 0;
}
EXPORT_SYMBOL(__sock_queue_rcv_skb);

int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	int err;

	err = sk_filter(sk, skb);
	if (err)
		return err;

	return __sock_queue_rcv_skb(sk, skb);
}
EXPORT_SYMBOL(sock_queue_rcv_skb);

int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
		     const int nested, unsigned int trim_cap, bool refcounted)
{
	int rc = NET_RX_SUCCESS;

	if (sk_filter_trim_cap(sk, skb, trim_cap))
		goto discard_and_relse;

	skb->dev = NULL;

	if (sk_rcvqueues_full(sk, 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, _RET_IP_);
	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
		bh_unlock_sock(sk);
		atomic_inc(&sk->sk_drops);
		goto discard_and_relse;
	}

	bh_unlock_sock(sk);
out:
	if (refcounted)
		sock_put(sk);
	return rc;
discard_and_relse:
	kfree_skb(skb);
	goto out;
}
EXPORT_SYMBOL(__sk_receive_skb);

struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
{
	struct dst_entry *dst = __sk_dst_get(sk);

	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
		sk_tx_queue_clear(sk);
		sk->sk_dst_pending_confirm = 0;
		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_locked(struct sock *sk, int ifindex)
{
	int ret = -ENOPROTOOPT;
#ifdef CONFIG_NETDEVICES
	struct net *net = sock_net(sk);

	/* Sorry... */
	ret = -EPERM;
	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
		goto out;

	ret = -EINVAL;
	if (ifindex < 0)
		goto out;

	sk->sk_bound_dev_if = ifindex;
	if (sk->sk_prot->rehash)
		sk->sk_prot->rehash(sk);
	sk_dst_reset(sk);

	ret = 0;

out:
#endif

	return ret;
}

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;

	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);
	ret = sock_setbindtodevice_locked(sk, index);
	release_sock(sk);

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);
	char devname[IFNAMSIZ];

	if (sk->sk_bound_dev_if == 0) {
		len = 0;
		goto zero;
	}

	ret = -EINVAL;
	if (len < IFNAMSIZ)
		goto out;

	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
	if (ret)
		goto out;

	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, enum sock_flags bit,
				     int valbool)
{
	if (valbool)
		sock_set_flag(sk, bit);
	else
		sock_reset_flag(sk, bit);
}

bool sk_mc_loop(struct sock *sk)
{
	if (dev_recursion_level())
		return false;
	if (!sk)
		return true;
	switch (sk->sk_family) {
	case AF_INET:
		return inet_sk(sk)->mc_loop;
#if IS_ENABLED(CONFIG_IPV6)
	case AF_INET6:
		return inet6_sk(sk)->mc_loop;
#endif
	}
	WARN_ON(1);
	return true;
}
EXPORT_SYMBOL(sk_mc_loop);

/*
 *	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_txtime sk_txtime;
	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_REUSEPORT:
		sk->sk_reuseport = valbool;
		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);
		sk_dst_reset(sk);
		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:
		/* Ensure val * 2 fits into an int, to prevent max_t()
		 * from treating it as a negative value.
		 */
		val = min_t(int, val, INT_MAX / 2);
		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
		WRITE_ONCE(sk->sk_sndbuf,
			   max_t(int, 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;
		}

		/* No negative values (to prevent underflow, as val will be
		 * multiplied by 2).
		 */
		if (val < 0)
			val = 0;
		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:
		/* Ensure val * 2 fits into an int, to prevent max_t()
		 * from treating it as a negative value.
		 */
		val = min_t(int, val, INT_MAX / 2);
		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.
		 */
		WRITE_ONCE(sk->sk_rcvbuf,
			   max_t(int, val * 2, SOCK_MIN_RCVBUF));
		break;

	case SO_RCVBUFFORCE:
		if (!capable(CAP_NET_ADMIN)) {
			ret = -EPERM;
			break;
		}

		/* No negative values (to prevent underflow, as val will be
		 * multiplied by 2).
		 */
		if (val < 0)
			val = 0;
		goto set_rcvbuf;

	case SO_KEEPALIVE:
		if (sk->sk_prot->keepalive)
			sk->sk_prot->keepalive(sk, valbool);
		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_tx = 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_OLD:
	case SO_TIMESTAMP_NEW:
	case SO_TIMESTAMPNS_OLD:
	case SO_TIMESTAMPNS_NEW:
		if (valbool)  {
			if (optname == SO_TIMESTAMP_NEW || optname == SO_TIMESTAMPNS_NEW)
				sock_set_flag(sk, SOCK_TSTAMP_NEW);
			else
				sock_reset_flag(sk, SOCK_TSTAMP_NEW);

			if (optname == SO_TIMESTAMP_OLD || optname == SO_TIMESTAMP_NEW)
				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);
			sock_reset_flag(sk, SOCK_TSTAMP_NEW);
		}
		break;

	case SO_TIMESTAMPING_NEW:
		sock_set_flag(sk, SOCK_TSTAMP_NEW);
		/* fall through */
	case SO_TIMESTAMPING_OLD:
		if (val & ~SOF_TIMESTAMPING_MASK) {
			ret = -EINVAL;
			break;
		}

		if (val & SOF_TIMESTAMPING_OPT_ID &&
		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
			if (sk->sk_protocol == IPPROTO_TCP &&
			    sk->sk_type == SOCK_STREAM) {
				if ((1 << sk->sk_state) &
				    (TCPF_CLOSE | TCPF_LISTEN)) {
					ret = -EINVAL;
					break;
				}
				sk->sk_tskey = tcp_sk(sk)->snd_una;
			} else {
				sk->sk_tskey = 0;
			}
		}

		if (val & SOF_TIMESTAMPING_OPT_STATS &&
		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
			ret = -EINVAL;
			break;
		}

		sk->sk_tsflags = val;
		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
			sock_enable_timestamp(sk,
					      SOCK_TIMESTAMPING_RX_SOFTWARE);
		else {
			if (optname == SO_TIMESTAMPING_NEW)
				sock_reset_flag(sk, SOCK_TSTAMP_NEW);

			sock_disable_timestamp(sk,
					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
		}
		break;

	case SO_RCVLOWAT:
		if (val < 0)
			val = INT_MAX;
		if (sock->ops->set_rcvlowat)
			ret = sock->ops->set_rcvlowat(sk, val);
		else
			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
		break;

	case SO_RCVTIMEO_OLD:
	case SO_RCVTIMEO_NEW:
		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen, optname == SO_RCVTIMEO_OLD);
		break;

	case SO_SNDTIMEO_OLD:
	case SO_SNDTIMEO_NEW:
		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen, optname == SO_SNDTIMEO_OLD);
		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_ATTACH_BPF:
		ret = -EINVAL;
		if (optlen == sizeof(u32)) {
			u32 ufd;

			ret = -EFAULT;
			if (copy_from_user(&ufd, optval, sizeof(ufd)))
				break;

			ret = sk_attach_bpf(ufd, sk);
		}
		break;

	case SO_ATTACH_REUSEPORT_CBPF:
		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_reuseport_attach_filter(&fprog, sk);
		}
		break;

	case SO_ATTACH_REUSEPORT_EBPF:
		ret = -EINVAL;
		if (optlen == sizeof(u32)) {
			u32 ufd;

			ret = -EFAULT;
			if (copy_from_user(&ufd, optval, sizeof(ufd)))
				break;

			ret = sk_reuseport_attach_bpf(ufd, sk);
		}
		break;

	case SO_DETACH_REUSEPORT_BPF:
		ret = reuseport_detach_prog(sk);
		break;

	case SO_DETACH_FILTER:
		ret = sk_detach_filter(sk);
		break;

	case SO_LOCK_FILTER:
		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
			ret = -EPERM;
		else
			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
		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 if (val != sk->sk_mark) {
			sk->sk_mark = val;
			sk_dst_reset(sk);
		}
		break;

	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)
			ret = sock->ops->set_peek_off(sk, val);
		else
			ret = -EOPNOTSUPP;
		break;

	case SO_NOFCS:
		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
		break;

	case SO_SELECT_ERR_QUEUE:
		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
		break;

#ifdef CONFIG_NET_RX_BUSY_POLL
	case SO_BUSY_POLL:
		/* allow unprivileged users to decrease the value */
		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
			ret = -EPERM;
		else {
			if (val < 0)
				ret = -EINVAL;
			else
				sk->sk_ll_usec = val;
		}
		break;
#endif

	case SO_MAX_PACING_RATE:
		{
		unsigned long ulval = (val == ~0U) ? ~0UL : val;

		if (sizeof(ulval) != sizeof(val) &&
		    optlen >= sizeof(ulval) &&
		    get_user(ulval, (unsigned long __user *)optval)) {
			ret = -EFAULT;
			break;
		}
		if (ulval != ~0UL)
			cmpxchg(&sk->sk_pacing_status,
				SK_PACING_NONE,
				SK_PACING_NEEDED);
		sk->sk_max_pacing_rate = ulval;
		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
		break;
		}
	case SO_INCOMING_CPU:
		WRITE_ONCE(sk->sk_incoming_cpu, val);
		break;

	case SO_CNX_ADVICE:
		if (val == 1)
			dst_negative_advice(sk);
		break;

	case SO_ZEROCOPY:
		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
			if (!((sk->sk_type == SOCK_STREAM &&
			       sk->sk_protocol == IPPROTO_TCP) ||
			      (sk->sk_type == SOCK_DGRAM &&
			       sk->sk_protocol == IPPROTO_UDP)))
				ret = -ENOTSUPP;
		} else if (sk->sk_family != PF_RDS) {
			ret = -ENOTSUPP;
		}
		if (!ret) {
			if (val < 0 || val > 1)
				ret = -EINVAL;
			else
				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
		}
		break;

	case SO_TXTIME:
		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
			ret = -EPERM;
		} else if (optlen != sizeof(struct sock_txtime)) {
			ret = -EINVAL;
		} else if (copy_from_user(&sk_txtime, optval,
			   sizeof(struct sock_txtime))) {
			ret = -EFAULT;
		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
			ret = -EINVAL;
		} else {
			sock_valbool_flag(sk, SOCK_TXTIME, true);
			sk->sk_clockid = sk_txtime.clockid;
			sk->sk_txtime_deadline_mode =
				!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
			sk->sk_txtime_report_errors =
				!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
		}
		break;

	case SO_BINDTOIFINDEX:
		ret = sock_setbindtodevice_locked(sk, val);
		break;

	default:
		ret = -ENOPROTOOPT;
		break;
	}
	release_sock(sk);
	return ret;
}
EXPORT_SYMBOL(sock_setsockopt);


static 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);
	}
}

static int groups_to_user(gid_t __user *dst, const struct group_info *src)
{
	struct user_namespace *user_ns = current_user_ns();
	int i;

	for (i = 0; i < src->ngroups; i++)
		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
			return -EFAULT;

	return 0;
}

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

	union {
		int val;
		u64 val64;
		unsigned long ulval;
		struct linger ling;
		struct old_timeval32 tm32;
		struct __kernel_old_timeval tm;
		struct  __kernel_sock_timeval stm;
		struct sock_txtime txtime;
	} 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_REUSEPORT:
		v.val = sk->sk_reuseport;
		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_tx;
		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_OLD:
		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
				!sock_flag(sk, SOCK_RCVTSTAMPNS);
		break;

	case SO_TIMESTAMPNS_OLD:
		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
		break;

	case SO_TIMESTAMP_NEW:
		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
		break;

	case SO_TIMESTAMPNS_NEW:
		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
		break;

	case SO_TIMESTAMPING_OLD:
		v.val = sk->sk_tsflags;
		break;

	case SO_RCVTIMEO_OLD:
	case SO_RCVTIMEO_NEW:
		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
		break;

	case SO_SNDTIMEO_OLD:
	case SO_SNDTIMEO_NEW:
		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
		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_PEERGROUPS:
	{
		int ret, n;

		if (!sk->sk_peer_cred)
			return -ENODATA;

		n = sk->sk_peer_cred->group_info->ngroups;
		if (len < n * sizeof(gid_t)) {
			len = n * sizeof(gid_t);
			return put_user(len, optlen) ? -EFAULT : -ERANGE;
		}
		len = n * sizeof(gid_t);

		ret = groups_to_user((gid_t __user *)optval,
				     sk->sk_peer_cred->group_info);
		if (ret)
			return ret;
		goto lenout;
	}

	case SO_PEERNAME:
	{
		char address[128];

		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
		if (lv < 0)
			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;

	case SO_LOCK_FILTER:
		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
		break;

	case SO_BPF_EXTENSIONS:
		v.val = bpf_tell_extensions();
		break;

	case SO_SELECT_ERR_QUEUE:
		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
		break;

#ifdef CONFIG_NET_RX_BUSY_POLL
	case SO_BUSY_POLL:
		v.val = sk->sk_ll_usec;
		break;
#endif

	case SO_MAX_PACING_RATE:
		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
			lv = sizeof(v.ulval);
			v.ulval = sk->sk_max_pacing_rate;
		} else {
			/* 32bit version */
			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
		}
		break;

	case SO_INCOMING_CPU:
		v.val = READ_ONCE(sk->sk_incoming_cpu);
		break;

	case SO_MEMINFO:
	{
		u32 meminfo[SK_MEMINFO_VARS];

		sk_get_meminfo(sk, meminfo);

		len = min_t(unsigned int, len, sizeof(meminfo));
		if (copy_to_user(optval, &meminfo, len))
			return -EFAULT;

		goto lenout;
	}

#ifdef CONFIG_NET_RX_BUSY_POLL
	case SO_INCOMING_NAPI_ID:
		v.val = READ_ONCE(sk->sk_napi_id);

		/* aggregate non-NAPI IDs down to 0 */
		if (v.val < MIN_NAPI_ID)
			v.val = 0;

		break;
#endif

	case SO_COOKIE:
		lv = sizeof(u64);
		if (len < lv)
			return -EINVAL;
		v.val64 = sock_gen_cookie(sk);
		break;

	case SO_ZEROCOPY:
		v.val = sock_flag(sk, SOCK_ZEROCOPY);
		break;

	case SO_TXTIME:
		lv = sizeof(v.txtime);
		v.txtime.clockid = sk->sk_clockid;
		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
				  SOF_TXTIME_DEADLINE_MODE : 0;
		v.txtime.flags |= sk->sk_txtime_report_errors ?
				  SOF_TXTIME_REPORT_ERRORS : 0;
		break;

	case SO_BINDTOIFINDEX:
		v.val = sk->sk_bound_dev_if;
		break;

	default:
		/* We implement the SO_SNDLOWAT etc to not be settable
		 * (1003.1g 7).
		 */
		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)
{
	if (sk->sk_kern_sock)
		sock_lock_init_class_and_name(
			sk,
			af_family_kern_slock_key_strings[sk->sk_family],
			af_family_kern_slock_keys + sk->sk_family,
			af_family_kern_key_strings[sk->sk_family],
			af_family_kern_keys + sk->sk_family);
	else
		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)
{
	const struct proto *prot = READ_ONCE(osk->sk_prot);
#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,
	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));

#ifdef CONFIG_SECURITY_NETWORK
	nsk->sk_security = sptr;
	security_sk_clone(osk, nsk);
#endif
}

static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
		int family)
{
	struct sock *sk;
	struct kmem_cache *slab;

	slab = prot->slab;
	if (slab != NULL) {
		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
		if (!sk)
			return sk;
		if (want_init_on_alloc(priority))
			sk_prot_clear_nulls(sk, prot->obj_size);
	} else
		sk = kmalloc(prot->obj_size, priority);

	if (sk != NULL) {
		if (security_sk_alloc(sk, family, priority))
			goto out_free;

		if (!try_module_get(prot->owner))
			goto out_free_sec;
		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;

	cgroup_sk_free(&sk->sk_cgrp_data);
	mem_cgroup_sk_free(sk);
	security_sk_free(sk);
	if (slab != NULL)
		kmem_cache_free(slab, sk);
	else
		kfree(sk);
	module_put(owner);
}

/**
 *	sk_alloc - All socket objects are allocated here
 *	@net: the applicable net namespace
 *	@family: protocol family
 *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
 *	@prot: struct proto associated with this new sock instance
 *	@kern: is this to be a kernel socket?
 */
struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
		      struct proto *prot, int kern)
{
	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;
		sk->sk_kern_sock = kern;
		sock_lock_init(sk);
		sk->sk_net_refcnt = kern ? 0 : 1;
		if (likely(sk->sk_net_refcnt)) {
			get_net(net);
			sock_inuse_add(net, 1);
		}

		sock_net_set(sk, net);
		refcount_set(&sk->sk_wmem_alloc, 1);

		mem_cgroup_sk_alloc(sk);
		cgroup_sk_alloc(&sk->sk_cgrp_data);
		sock_update_classid(&sk->sk_cgrp_data);
		sock_update_netprioidx(&sk->sk_cgrp_data);
	}

	return sk;
}
EXPORT_SYMBOL(sk_alloc);

/* Sockets having SOCK_RCU_FREE will call this function after one RCU
 * grace period. This is the case for UDP sockets and TCP listeners.
 */
static void __sk_destruct(struct rcu_head *head)
{
	struct sock *sk = container_of(head, struct sock, sk_rcu);
	struct sk_filter *filter;

	if (sk->sk_destruct)
		sk->sk_destruct(sk);

	filter = rcu_dereference_check(sk->sk_filter,
				       refcount_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);

#ifdef CONFIG_BPF_SYSCALL
	bpf_sk_storage_free(sk);
#endif

	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_frag.page) {
		put_page(sk->sk_frag.page);
		sk->sk_frag.page = NULL;
	}

	if (sk->sk_peer_cred)
		put_cred(sk->sk_peer_cred);
	put_pid(sk->sk_peer_pid);
	if (likely(sk->sk_net_refcnt))
		put_net(sock_net(sk));
	sk_prot_free(sk->sk_prot_creator, sk);
}

void sk_destruct(struct sock *sk)
{
	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);

	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
		reuseport_detach_sock(sk);
		use_call_rcu = true;
	}

	if (use_call_rcu)
		call_rcu(&sk->sk_rcu, __sk_destruct);
	else
		__sk_destruct(&sk->sk_rcu);
}

static void __sk_free(struct sock *sk)
{
	if (likely(sk->sk_net_refcnt))
		sock_inuse_add(sock_net(sk), -1);

	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
		sock_diag_broadcast_destroy(sk);
	else
		sk_destruct(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 (refcount_dec_and_test(&sk->sk_wmem_alloc))
		__sk_free(sk);
}
EXPORT_SYMBOL(sk_free);

static void sk_init_common(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);

	rwlock_init(&sk->sk_callback_lock);
	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
			af_rlock_keys + sk->sk_family,
			af_family_rlock_key_strings[sk->sk_family]);
	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
			af_wlock_keys + sk->sk_family,
			af_family_wlock_key_strings[sk->sk_family]);
	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
			af_elock_keys + sk->sk_family,
			af_family_elock_key_strings[sk->sk_family]);
	lockdep_set_class_and_name(&sk->sk_callback_lock,
			af_callback_keys + sk->sk_family,
			af_family_clock_key_strings[sk->sk_family]);
}

/**
 *	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 proto *prot = READ_ONCE(sk->sk_prot);
	struct sock *newsk;
	bool is_charged = true;

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

		sock_copy(newsk, sk);

		newsk->sk_prot_creator = prot;

		/* SANITY */
		if (likely(newsk->sk_net_refcnt))
			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())
		 */
		refcount_set(&newsk->sk_wmem_alloc, 1);
		atomic_set(&newsk->sk_omem_alloc, 0);
		sk_init_common(newsk);

		newsk->sk_dst_cache	= NULL;
		newsk->sk_dst_pending_confirm = 0;
		newsk->sk_wmem_queued	= 0;
		newsk->sk_forward_alloc = 0;
		atomic_set(&newsk->sk_drops, 0);
		newsk->sk_send_head	= NULL;
		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
		atomic_set(&newsk->sk_zckey, 0);

		sock_reset_flag(newsk, SOCK_DONE);

		/* sk->sk_memcg will be populated at accept() time */
		newsk->sk_memcg = NULL;

		cgroup_sk_alloc(&newsk->sk_cgrp_data);

		rcu_read_lock();
		filter = rcu_dereference(sk->sk_filter);
		if (filter != NULL)
			/* though it's an empty new sock, the charging may fail
			 * if sysctl_optmem_max was changed between creation of
			 * original socket and cloning
			 */
			is_charged = sk_filter_charge(newsk, filter);
		RCU_INIT_POINTER(newsk->sk_filter, filter);
		rcu_read_unlock();

		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
			/* We need to make sure that we don't uncharge the new
			 * socket if we couldn't charge it in the first place
			 * as otherwise we uncharge the parent's filter.
			 */
			if (!is_charged)
				RCU_INIT_POINTER(newsk->sk_filter, NULL);
			sk_free_unlock_clone(newsk);
			newsk = NULL;
			goto out;
		}
		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);

		if (bpf_sk_storage_clone(sk, newsk)) {
			sk_free_unlock_clone(newsk);
			newsk = NULL;
			goto out;
		}

		/* Clear sk_user_data if parent had the pointer tagged
		 * as not suitable for copying when cloning.
		 */
		if (sk_user_data_is_nocopy(newsk))
			newsk->sk_user_data = NULL;

		newsk->sk_err	   = 0;
		newsk->sk_err_soft = 0;
		newsk->sk_priority = 0;
		newsk->sk_incoming_cpu = raw_smp_processor_id();
		if (likely(newsk->sk_net_refcnt))
			sock_inuse_add(sock_net(newsk), 1);

		/*
		 * Before updating sk_refcnt, we must commit prior changes to memory
		 * (Documentation/RCU/rculist_nulls.txt for details)
		 */
		smp_wmb();
		refcount_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);
		RCU_INIT_POINTER(newsk->sk_wq, NULL);

		if (newsk->sk_prot->sockets_allocated)
			sk_sockets_allocated_inc(newsk);

		if (sock_needs_netstamp(sk) &&
		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
			net_enable_timestamp();
	}
out:
	return newsk;
}
EXPORT_SYMBOL_GPL(sk_clone_lock);

void sk_free_unlock_clone(struct sock *sk)
{
	/* It is still raw copy of parent, so invalidate
	 * destructor and make plain sk_free() */
	sk->sk_destruct = NULL;
	bh_unlock_sock(sk);
	sk_free(sk);
}
EXPORT_SYMBOL_GPL(sk_free_unlock_clone);

void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
{
	u32 max_segs = 1;

	sk_dst_set(sk, dst);
	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
	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 && !xfrm_dst_offload_ok(dst)) {
			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;
			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
		}
	}
	sk->sk_gso_max_segs = 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
		 */
		WARN_ON(refcount_sub_and_test(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 (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
		__sk_free(sk);
}
EXPORT_SYMBOL(sock_wfree);

/* This variant of sock_wfree() is used by TCP,
 * since it sets SOCK_USE_WRITE_QUEUE.
 */
void __sock_wfree(struct sk_buff *skb)
{
	struct sock *sk = skb->sk;

	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
		__sk_free(sk);
}

void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
{
	skb_orphan(skb);
	skb->sk = sk;
#ifdef CONFIG_INET
	if (unlikely(!sk_fullsock(sk))) {
		skb->destructor = sock_edemux;
		sock_hold(sk);
		return;
	}
#endif
	skb->destructor = sock_wfree;
	skb_set_hash_from_sk(skb, sk);
	/*
	 * We used to take a refcount on sk, but following operation
	 * is enough to guarantee sk_free() wont free this sock until
	 * all in-flight packets are completed
	 */
	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
}
EXPORT_SYMBOL(skb_set_owner_w);

static bool can_skb_orphan_partial(const struct sk_buff *skb)
{
#ifdef CONFIG_TLS_DEVICE
	/* Drivers depend on in-order delivery for crypto offload,
	 * partial orphan breaks out-of-order-OK logic.
	 */
	if (skb->decrypted)
		return false;
#endif
	return (skb->destructor == sock_wfree ||
		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
}

/* This helper is used by netem, as it can hold packets i…