Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2094 insertions, 0 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
new file mode 100644
index 000000000..acb488735
--- /dev/null
+++ b/net/ipv4/af_inet.c
@@ -0,0 +1,2094 @@
+// 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.
+ *
+ *		PF_INET protocol family socket 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>
+ *
+ * Changes (see also sock.c)
+ *
+ *		piggy,
+ *		Karl Knutson	:	Socket protocol table
+ *		A.N.Kuznetsov	:	Socket death error in accept().
+ *		John Richardson :	Fix non blocking error in connect()
+ *					so sockets that fail to connect
+ *					don't return -EINPROGRESS.
+ *		Alan Cox	:	Asynchronous I/O support
+ *		Alan Cox	:	Keep correct socket pointer on sock
+ *					structures
+ *					when accept() ed
+ *		Alan Cox	:	Semantics of SO_LINGER aren't state
+ *					moved to close when you look carefully.
+ *					With this fixed and the accept bug fixed
+ *					some RPC stuff seems happier.
+ *		Niibe Yutaka	:	4.4BSD style write async I/O
+ *		Alan Cox,
+ *		Tony Gale 	:	Fixed reuse semantics.
+ *		Alan Cox	:	bind() shouldn't abort existing but dead
+ *					sockets. Stops FTP netin:.. I hope.
+ *		Alan Cox	:	bind() works correctly for RAW sockets.
+ *					Note that FreeBSD at least was broken
+ *					in this respect so be careful with
+ *					compatibility tests...
+ *		Alan Cox	:	routing cache support
+ *		Alan Cox	:	memzero the socket structure for
+ *					compactness.
+ *		Matt Day	:	nonblock connect error handler
+ *		Alan Cox	:	Allow large numbers of pending sockets
+ *					(eg for big web sites), but only if
+ *					specifically application requested.
+ *		Alan Cox	:	New buffering throughout IP. Used
+ *					dumbly.
+ *		Alan Cox	:	New buffering now used smartly.
+ *		Alan Cox	:	BSD rather than common sense
+ *					interpretation of listen.
+ *		Germano Caronni	:	Assorted small races.
+ *		Alan Cox	:	sendmsg/recvmsg basic support.
+ *		Alan Cox	:	Only sendmsg/recvmsg now supported.
+ *		Alan Cox	:	Locked down bind (see security list).
+ *		Alan Cox	:	Loosened bind a little.
+ *		Mike McLagan	:	ADD/DEL DLCI Ioctls
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *		David S. Miller	:	New socket lookup architecture.
+ *					Some other random speedups.
+ *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
+ *		Andi Kleen	:	Fix inet_stream_connect TCP race.
+ */
+
+#define pr_fmt(fmt) "IPv4: " fmt
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/capability.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+
+#include <linux/uaccess.h>
+
+#include <linux/inet.h>
+#include <linux/igmp.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <net/checksum.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/arp.h>
+#include <net/route.h>
+#include <net/ip_fib.h>
+#include <net/inet_connection_sock.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <net/ping.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/raw.h>
+#include <net/icmp.h>
+#include <net/inet_common.h>
+#include <net/ip_tunnels.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/secure_seq.h>
+#ifdef CONFIG_IP_MROUTE
+#include <linux/mroute.h>
+#endif
+#include <net/l3mdev.h>
+#include <net/compat.h>
+
+#include <trace/events/sock.h>
+
+/* The inetsw table contains everything that inet_create needs to
+ * build a new socket.
+ */
+static struct list_head inetsw[SOCK_MAX];
+static DEFINE_SPINLOCK(inetsw_lock);
+
+/* New destruction routine */
+
+void inet_sock_destruct(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+
+	__skb_queue_purge(&sk->sk_receive_queue);
+	if (sk->sk_rx_skb_cache) {
+		__kfree_skb(sk->sk_rx_skb_cache);
+		sk->sk_rx_skb_cache = NULL;
+	}
+	__skb_queue_purge(&sk->sk_error_queue);
+
+	sk_mem_reclaim(sk);
+
+	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
+		pr_err("Attempt to release TCP socket in state %d %p\n",
+		       sk->sk_state, sk);
+		return;
+	}
+	if (!sock_flag(sk, SOCK_DEAD)) {
+		pr_err("Attempt to release alive inet socket %p\n", sk);
+		return;
+	}
+
+	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
+	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
+	WARN_ON(sk->sk_wmem_queued);
+	WARN_ON(sk->sk_forward_alloc);
+
+	kfree(rcu_dereference_protected(inet->inet_opt, 1));
+	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
+	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
+	sk_refcnt_debug_dec(sk);
+}
+EXPORT_SYMBOL(inet_sock_destruct);
+
+/*
+ *	The routines beyond this point handle the behaviour of an AF_INET
+ *	socket object. Mostly it punts to the subprotocols of IP to do
+ *	the work.
+ */
+
+/*
+ *	Automatically bind an unbound socket.
+ */
+
+static int inet_autobind(struct sock *sk)
+{
+	struct inet_sock *inet;
+	/* We may need to bind the socket. */
+	lock_sock(sk);
+	inet = inet_sk(sk);
+	if (!inet->inet_num) {
+		if (sk->sk_prot->get_port(sk, 0)) {
+			release_sock(sk);
+			return -EAGAIN;
+		}
+		inet->inet_sport = htons(inet->inet_num);
+	}
+	release_sock(sk);
+	return 0;
+}
+
+/*
+ *	Move a socket into listening state.
+ */
+int inet_listen(struct socket *sock, int backlog)
+{
+	struct sock *sk = sock->sk;
+	unsigned char old_state;
+	int err, tcp_fastopen;
+
+	lock_sock(sk);
+
+	err = -EINVAL;
+	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
+		goto out;
+
+	old_state = sk->sk_state;
+	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
+		goto out;
+
+	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
+	/* Really, if the socket is already in listen state
+	 * we can only allow the backlog to be adjusted.
+	 */
+	if (old_state != TCP_LISTEN) {
+		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
+		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
+		 * Also fastopen backlog may already been set via the option
+		 * because the socket was in TCP_LISTEN state previously but
+		 * was shutdown() rather than close().
+		 */
+		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
+		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
+		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
+		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
+			fastopen_queue_tune(sk, backlog);
+			tcp_fastopen_init_key_once(sock_net(sk));
+		}
+
+		err = inet_csk_listen_start(sk, backlog);
+		if (err)
+			goto out;
+		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
+	}
+	err = 0;
+
+out:
+	release_sock(sk);
+	return err;
+}
+EXPORT_SYMBOL(inet_listen);
+
+/*
+ *	Create an inet socket.
+ */
+
+static int inet_create(struct net *net, struct socket *sock, int protocol,
+		       int kern)
+{
+	struct sock *sk;
+	struct inet_protosw *answer;
+	struct inet_sock *inet;
+	struct proto *answer_prot;
+	unsigned char answer_flags;
+	int try_loading_module = 0;
+	int err;
+
+	if (protocol < 0 || protocol >= IPPROTO_MAX)
+		return -EINVAL;
+
+	sock->state = SS_UNCONNECTED;
+
+	/* Look for the requested type/protocol pair. */
+lookup_protocol:
+	err = -ESOCKTNOSUPPORT;
+	rcu_read_lock();
+	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
+
+		err = 0;
+		/* Check the non-wild match. */
+		if (protocol == answer->protocol) {
+			if (protocol != IPPROTO_IP)
+				break;
+		} else {
+			/* Check for the two wild cases. */
+			if (IPPROTO_IP == protocol) {
+				protocol = answer->protocol;
+				break;
+			}
+			if (IPPROTO_IP == answer->protocol)
+				break;
+		}
+		err = -EPROTONOSUPPORT;
+	}
+
+	if (unlikely(err)) {
+		if (try_loading_module < 2) {
+			rcu_read_unlock();
+			/*
+			 * Be more specific, e.g. net-pf-2-proto-132-type-1
+			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
+			 */
+			if (++try_loading_module == 1)
+				request_module("net-pf-%d-proto-%d-type-%d",
+					       PF_INET, protocol, sock->type);
+			/*
+			 * Fall back to generic, e.g. net-pf-2-proto-132
+			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
+			 */
+			else
+				request_module("net-pf-%d-proto-%d",
+					       PF_INET, protocol);
+			goto lookup_protocol;
+		} else
+			goto out_rcu_unlock;
+	}
+
+	err = -EPERM;
+	if (sock->type == SOCK_RAW && !kern &&
+	    !ns_capable(net->user_ns, CAP_NET_RAW))
+		goto out_rcu_unlock;
+
+	sock->ops = answer->ops;
+	answer_prot = answer->prot;
+	answer_flags = answer->flags;
+	rcu_read_unlock();
+
+	WARN_ON(!answer_prot->slab);
+
+	err = -ENOBUFS;
+	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
+	if (!sk)
+		goto out;
+
+	err = 0;
+	if (INET_PROTOSW_REUSE & answer_flags)
+		sk->sk_reuse = SK_CAN_REUSE;
+
+	inet = inet_sk(sk);
+	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
+
+	inet->nodefrag = 0;
+
+	if (SOCK_RAW == sock->type) {
+		inet->inet_num = protocol;
+		if (IPPROTO_RAW == protocol)
+			inet->hdrincl = 1;
+	}
+
+	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
+		inet->pmtudisc = IP_PMTUDISC_DONT;
+	else
+		inet->pmtudisc = IP_PMTUDISC_WANT;
+
+	inet->inet_id = 0;
+
+	sock_init_data(sock, sk);
+
+	sk->sk_destruct	   = inet_sock_destruct;
+	sk->sk_protocol	   = protocol;
+	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
+
+	inet->uc_ttl	= -1;
+	inet->mc_loop	= 1;
+	inet->mc_ttl	= 1;
+	inet->mc_all	= 1;
+	inet->mc_index	= 0;
+	inet->mc_list	= NULL;
+	inet->rcv_tos	= 0;
+
+	sk_refcnt_debug_inc(sk);
+
+	if (inet->inet_num) {
+		/* It assumes that any protocol which allows
+		 * the user to assign a number at socket
+		 * creation time automatically
+		 * shares.
+		 */
+		inet->inet_sport = htons(inet->inet_num);
+		/* Add to protocol hash chains. */
+		err = sk->sk_prot->hash(sk);
+		if (err) {
+			sk_common_release(sk);
+			goto out;
+		}
+	}
+
+	if (sk->sk_prot->init) {
+		err = sk->sk_prot->init(sk);
+		if (err) {
+			sk_common_release(sk);
+			goto out;
+		}
+	}
+
+	if (!kern) {
+		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
+		if (err) {
+			sk_common_release(sk);
+			goto out;
+		}
+	}
+out:
+	return err;
+out_rcu_unlock:
+	rcu_read_unlock();
+	goto out;
+}
+
+
+/*
+ *	The peer socket should always be NULL (or else). When we call this
+ *	function we are destroying the object and from then on nobody
+ *	should refer to it.
+ */
+int inet_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	if (sk) {
+		long timeout;
+
+		if (!sk->sk_kern_sock)
+			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
+
+		/* Applications forget to leave groups before exiting */
+		ip_mc_drop_socket(sk);
+
+		/* If linger is set, we don't return until the close
+		 * is complete.  Otherwise we return immediately. The
+		 * actually closing is done the same either way.
+		 *
+		 * If the close is due to the process exiting, we never
+		 * linger..
+		 */
+		timeout = 0;
+		if (sock_flag(sk, SOCK_LINGER) &&
+		    !(current->flags & PF_EXITING))
+			timeout = sk->sk_lingertime;
+		sk->sk_prot->close(sk, timeout);
+		sock->sk = NULL;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(inet_release);
+
+int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
+{
+	struct sock *sk = sock->sk;
+	int err;
+
+	/* If the socket has its own bind function then use it. (RAW) */
+	if (sk->sk_prot->bind) {
+		return sk->sk_prot->bind(sk, uaddr, addr_len);
+	}
+	if (addr_len < sizeof(struct sockaddr_in))
+		return -EINVAL;
+
+	/* BPF prog is run before any checks are done so that if the prog
+	 * changes context in a wrong way it will be caught.
+	 */
+	err = BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr);
+	if (err)
+		return err;
+
+	return __inet_bind(sk, uaddr, addr_len, BIND_WITH_LOCK);
+}
+EXPORT_SYMBOL(inet_bind);
+
+int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
+		u32 flags)
+{
+	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
+	struct inet_sock *inet = inet_sk(sk);
+	struct net *net = sock_net(sk);
+	unsigned short snum;
+	int chk_addr_ret;
+	u32 tb_id = RT_TABLE_LOCAL;
+	int err;
+
+	if (addr->sin_family != AF_INET) {
+		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
+		 * only if s_addr is INADDR_ANY.
+		 */
+		err = -EAFNOSUPPORT;
+		if (addr->sin_family != AF_UNSPEC ||
+		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
+			goto out;
+	}
+
+	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
+	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
+
+	/* Not specified by any standard per-se, however it breaks too
+	 * many applications when removed.  It is unfortunate since
+	 * allowing applications to make a non-local bind solves
+	 * several problems with systems using dynamic addressing.
+	 * (ie. your servers still start up even if your ISDN link
+	 *  is temporarily down)
+	 */
+	err = -EADDRNOTAVAIL;
+	if (!inet_can_nonlocal_bind(net, inet) &&
+	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
+	    chk_addr_ret != RTN_LOCAL &&
+	    chk_addr_ret != RTN_MULTICAST &&
+	    chk_addr_ret != RTN_BROADCAST)
+		goto out;
+
+	snum = ntohs(addr->sin_port);
+	err = -EACCES;
+	if (snum && inet_port_requires_bind_service(net, snum) &&
+	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
+		goto out;
+
+	/*      We keep a pair of addresses. rcv_saddr is the one
+	 *      used by hash lookups, and saddr is used for transmit.
+	 *
+	 *      In the BSD API these are the same except where it
+	 *      would be illegal to use them (multicast/broadcast) in
+	 *      which case the sending device address is used.
+	 */
+	if (flags & BIND_WITH_LOCK)
+		lock_sock(sk);
+
+	/* Check these errors (active socket, double bind). */
+	err = -EINVAL;
+	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
+		goto out_release_sock;
+
+	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
+	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
+		inet->inet_saddr = 0;  /* Use device */
+
+	/* Make sure we are allowed to bind here. */
+	if (snum || !(inet->bind_address_no_port ||
+		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
+		if (sk->sk_prot->get_port(sk, snum)) {
+			inet->inet_saddr = inet->inet_rcv_saddr = 0;
+			err = -EADDRINUSE;
+			goto out_release_sock;
+		}
+		if (!(flags & BIND_FROM_BPF)) {
+			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
+			if (err) {
+				inet->inet_saddr = inet->inet_rcv_saddr = 0;
+				goto out_release_sock;
+			}
+		}
+	}
+
+	if (inet->inet_rcv_saddr)
+		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
+	if (snum)
+		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
+	inet->inet_sport = htons(inet->inet_num);
+	inet->inet_daddr = 0;
+	inet->inet_dport = 0;
+	sk_dst_reset(sk);
+	err = 0;
+out_release_sock:
+	if (flags & BIND_WITH_LOCK)
+		release_sock(sk);
+out:
+	return err;
+}
+
+int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
+		       int addr_len, int flags)
+{
+	struct sock *sk = sock->sk;
+	int err;
+
+	if (addr_len < sizeof(uaddr->sa_family))
+		return -EINVAL;
+	if (uaddr->sa_family == AF_UNSPEC)
+		return sk->sk_prot->disconnect(sk, flags);
+
+	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
+		err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
+		if (err)
+			return err;
+	}
+
+	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
+		return -EAGAIN;
+	return sk->sk_prot->connect(sk, uaddr, addr_len);
+}
+EXPORT_SYMBOL(inet_dgram_connect);
+
+static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	sk->sk_write_pending += writebias;
+	sk->sk_wait_pending++;
+
+	/* Basic assumption: if someone sets sk->sk_err, he _must_
+	 * change state of the socket from TCP_SYN_*.
+	 * Connect() does not allow to get error notifications
+	 * without closing the socket.
+	 */
+	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+		release_sock(sk);
+		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
+		lock_sock(sk);
+		if (signal_pending(current) || !timeo)
+			break;
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+	sk->sk_write_pending -= writebias;
+	sk->sk_wait_pending--;
+	return timeo;
+}
+
+/*
+ *	Connect to a remote host. There is regrettably still a little
+ *	TCP 'magic' in here.
+ */
+int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
+			  int addr_len, int flags, int is_sendmsg)
+{
+	struct sock *sk = sock->sk;
+	int err;
+	long timeo;
+
+	/*
+	 * uaddr can be NULL and addr_len can be 0 if:
+	 * sk is a TCP fastopen active socket and
+	 * TCP_FASTOPEN_CONNECT sockopt is set and
+	 * we already have a valid cookie for this socket.
+	 * In this case, user can call write() after connect().
+	 * write() will invoke tcp_sendmsg_fastopen() which calls
+	 * __inet_stream_connect().
+	 */
+	if (uaddr) {
+		if (addr_len < sizeof(uaddr->sa_family))
+			return -EINVAL;
+
+		if (uaddr->sa_family == AF_UNSPEC) {
+			err = sk->sk_prot->disconnect(sk, flags);
+			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
+			goto out;
+		}
+	}
+
+	switch (sock->state) {
+	default:
+		err = -EINVAL;
+		goto out;
+	case SS_CONNECTED:
+		err = -EISCONN;
+		goto out;
+	case SS_CONNECTING:
+		if (inet_sk(sk)->defer_connect)
+			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
+		else
+			err = -EALREADY;
+		/* Fall out of switch with err, set for this state */
+		break;
+	case SS_UNCONNECTED:
+		err = -EISCONN;
+		if (sk->sk_state != TCP_CLOSE)
+			goto out;
+
+		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
+			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
+			if (err)
+				goto out;
+		}
+
+		err = sk->sk_prot->connect(sk, uaddr, addr_len);
+		if (err < 0)
+			goto out;
+
+		sock->state = SS_CONNECTING;
+
+		if (!err && inet_sk(sk)->defer_connect)
+			goto out;
+
+		/* Just entered SS_CONNECTING state; the only
+		 * difference is that return value in non-blocking
+		 * case is EINPROGRESS, rather than EALREADY.
+		 */
+		err = -EINPROGRESS;
+		break;
+	}
+
+	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
+
+	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
+				tcp_sk(sk)->fastopen_req &&
+				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
+
+		/* Error code is set above */
+		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
+			goto out;
+
+		err = sock_intr_errno(timeo);
+		if (signal_pending(current))
+			goto out;
+	}
+
+	/* Connection was closed by RST, timeout, ICMP error
+	 * or another process disconnected us.
+	 */
+	if (sk->sk_state == TCP_CLOSE)
+		goto sock_error;
+
+	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
+	 * and error was received after socket entered established state.
+	 * Hence, it is handled normally after connect() return successfully.
+	 */
+
+	sock->state = SS_CONNECTED;
+	err = 0;
+out:
+	return err;
+
+sock_error:
+	err = sock_error(sk) ? : -ECONNABORTED;
+	sock->state = SS_UNCONNECTED;
+	if (sk->sk_prot->disconnect(sk, flags))
+		sock->state = SS_DISCONNECTING;
+	goto out;
+}
+EXPORT_SYMBOL(__inet_stream_connect);
+
+int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
+			int addr_len, int flags)
+{
+	int err;
+
+	lock_sock(sock->sk);
+	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
+	release_sock(sock->sk);
+	return err;
+}
+EXPORT_SYMBOL(inet_stream_connect);
+
+/*
+ *	Accept a pending connection. The TCP layer now gives BSD semantics.
+ */
+
+int inet_accept(struct socket *sock, struct socket *newsock, int flags,
+		bool kern)
+{
+	struct sock *sk1 = sock->sk;
+	int err = -EINVAL;
+	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err, kern);
+
+	if (!sk2)
+		goto do_err;
+
+	lock_sock(sk2);
+
+	sock_rps_record_flow(sk2);
+	WARN_ON(!((1 << sk2->sk_state) &
+		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
+		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
+
+	sock_graft(sk2, newsock);
+
+	newsock->state = SS_CONNECTED;
+	err = 0;
+	release_sock(sk2);
+do_err:
+	return err;
+}
+EXPORT_SYMBOL(inet_accept);
+
+/*
+ *	This does both peername and sockname.
+ */
+int inet_getname(struct socket *sock, struct sockaddr *uaddr,
+		 int peer)
+{
+	struct sock *sk		= sock->sk;
+	struct inet_sock *inet	= inet_sk(sk);
+	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
+
+	sin->sin_family = AF_INET;
+	if (peer) {
+		if (!inet->inet_dport ||
+		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
+		     peer == 1))
+			return -ENOTCONN;
+		sin->sin_port = inet->inet_dport;
+		sin->sin_addr.s_addr = inet->inet_daddr;
+	} else {
+		__be32 addr = inet->inet_rcv_saddr;
+		if (!addr)
+			addr = inet->inet_saddr;
+		sin->sin_port = inet->inet_sport;
+		sin->sin_addr.s_addr = addr;
+	}
+	if (cgroup_bpf_enabled)
+		BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin,
+					    peer ? BPF_CGROUP_INET4_GETPEERNAME :
+						   BPF_CGROUP_INET4_GETSOCKNAME,
+					    NULL);
+	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+	return sizeof(*sin);
+}
+EXPORT_SYMBOL(inet_getname);
+
+int inet_send_prepare(struct sock *sk)
+{
+	sock_rps_record_flow(sk);
+
+	/* We may need to bind the socket. */
+	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
+	    inet_autobind(sk))
+		return -EAGAIN;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(inet_send_prepare);
+
+int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+	struct sock *sk = sock->sk;
+
+	if (unlikely(inet_send_prepare(sk)))
+		return -EAGAIN;
+
+	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
+			       sk, msg, size);
+}
+EXPORT_SYMBOL(inet_sendmsg);
+
+ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
+		      size_t size, int flags)
+{
+	struct sock *sk = sock->sk;
+
+	if (unlikely(inet_send_prepare(sk)))
+		return -EAGAIN;
+
+	if (sk->sk_prot->sendpage)
+		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
+	return sock_no_sendpage(sock, page, offset, size, flags);
+}
+EXPORT_SYMBOL(inet_sendpage);
+
+INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
+					  size_t, int, int, int *));
+int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+		 int flags)
+{
+	struct sock *sk = sock->sk;
+	int addr_len = 0;
+	int err;
+
+	if (likely(!(flags & MSG_ERRQUEUE)))
+		sock_rps_record_flow(sk);
+
+	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
+			      sk, msg, size, flags & MSG_DONTWAIT,
+			      flags & ~MSG_DONTWAIT, &addr_len);
+	if (err >= 0)
+		msg->msg_namelen = addr_len;
+	return err;
+}
+EXPORT_SYMBOL(inet_recvmsg);
+
+int inet_shutdown(struct socket *sock, int how)
+{
+	struct sock *sk = sock->sk;
+	int err = 0;
+
+	/* This should really check to make sure
+	 * the socket is a TCP socket. (WHY AC...)
+	 */
+	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
+		       1->2 bit 2 snds.
+		       2->3 */
+	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
+		return -EINVAL;
+
+	lock_sock(sk);
+	if (sock->state == SS_CONNECTING) {
+		if ((1 << sk->sk_state) &
+		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
+			sock->state = SS_DISCONNECTING;
+		else
+			sock->state = SS_CONNECTED;
+	}
+
+	switch (sk->sk_state) {
+	case TCP_CLOSE:
+		err = -ENOTCONN;
+		/* Hack to wake up other listeners, who can poll for
+		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
+		fallthrough;
+	default:
+		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
+		if (sk->sk_prot->shutdown)
+			sk->sk_prot->shutdown(sk, how);
+		break;
+
+	/* Remaining two branches are temporary solution for missing
+	 * close() in multithreaded environment. It is _not_ a good idea,
+	 * but we have no choice until close() is repaired at VFS level.
+	 */
+	case TCP_LISTEN:
+		if (!(how & RCV_SHUTDOWN))
+			break;
+		fallthrough;
+	case TCP_SYN_SENT:
+		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
+		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
+		break;
+	}
+
+	/* Wake up anyone sleeping in poll. */
+	sk->sk_state_change(sk);
+	release_sock(sk);
+	return err;
+}
+EXPORT_SYMBOL(inet_shutdown);
+
+/*
+ *	ioctl() calls you can issue on an INET socket. Most of these are
+ *	device configuration and stuff and very rarely used. Some ioctls
+ *	pass on to the socket itself.
+ *
+ *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
+ *	loads the devconfigure module does its configuring and unloads it.
+ *	There's a good 20K of config code hanging around the kernel.
+ */
+
+int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	struct sock *sk = sock->sk;
+	int err = 0;
+	struct net *net = sock_net(sk);
+	void __user *p = (void __user *)arg;
+	struct ifreq ifr;
+	struct rtentry rt;
+
+	switch (cmd) {
+	case SIOCADDRT:
+	case SIOCDELRT:
+		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
+			return -EFAULT;
+		err = ip_rt_ioctl(net, cmd, &rt);
+		break;
+	case SIOCRTMSG:
+		err = -EINVAL;
+		break;
+	case SIOCDARP:
+	case SIOCGARP:
+	case SIOCSARP:
+		err = arp_ioctl(net, cmd, (void __user *)arg);
+		break;
+	case SIOCGIFADDR:
+	case SIOCGIFBRDADDR:
+	case SIOCGIFNETMASK:
+	case SIOCGIFDSTADDR:
+	case SIOCGIFPFLAGS:
+		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
+			return -EFAULT;
+		err = devinet_ioctl(net, cmd, &ifr);
+		if (!err && copy_to_user(p, &ifr, sizeof(struct ifreq)))
+			err = -EFAULT;
+		break;
+
+	case SIOCSIFADDR:
+	case SIOCSIFBRDADDR:
+	case SIOCSIFNETMASK:
+	case SIOCSIFDSTADDR:
+	case SIOCSIFPFLAGS:
+	case SIOCSIFFLAGS:
+		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
+			return -EFAULT;
+		err = devinet_ioctl(net, cmd, &ifr);
+		break;
+	default:
+		if (sk->sk_prot->ioctl)
+			err = sk->sk_prot->ioctl(sk, cmd, arg);
+		else
+			err = -ENOIOCTLCMD;
+		break;
+	}
+	return err;
+}
+EXPORT_SYMBOL(inet_ioctl);
+
+#ifdef CONFIG_COMPAT
+static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
+		struct compat_rtentry __user *ur)
+{
+	compat_uptr_t rtdev;
+	struct rtentry rt;
+
+	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
+			3 * sizeof(struct sockaddr)) ||
+	    get_user(rt.rt_flags, &ur->rt_flags) ||
+	    get_user(rt.rt_metric, &ur->rt_metric) ||
+	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
+	    get_user(rt.rt_window, &ur->rt_window) ||
+	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
+	    get_user(rtdev, &ur->rt_dev))
+		return -EFAULT;
+
+	rt.rt_dev = compat_ptr(rtdev);
+	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
+}
+
+static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = compat_ptr(arg);
+	struct sock *sk = sock->sk;
+
+	switch (cmd) {
+	case SIOCADDRT:
+	case SIOCDELRT:
+		return inet_compat_routing_ioctl(sk, cmd, argp);
+	default:
+		if (!sk->sk_prot->compat_ioctl)
+			return -ENOIOCTLCMD;
+		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
+	}
+}
+#endif /* CONFIG_COMPAT */
+
+const struct proto_ops inet_stream_ops = {
+	.family		   = PF_INET,
+	.owner		   = THIS_MODULE,
+	.release	   = inet_release,
+	.bind		   = inet_bind,
+	.connect	   = inet_stream_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = inet_accept,
+	.getname	   = inet_getname,
+	.poll		   = tcp_poll,
+	.ioctl		   = inet_ioctl,
+	.gettstamp	   = sock_gettstamp,
+	.listen		   = inet_listen,
+	.shutdown	   = inet_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = inet_sendmsg,
+	.recvmsg	   = inet_recvmsg,
+#ifdef CONFIG_MMU
+	.mmap		   = tcp_mmap,
+#endif
+	.sendpage	   = inet_sendpage,
+	.splice_read	   = tcp_splice_read,
+	.read_sock	   = tcp_read_sock,
+	.sendmsg_locked    = tcp_sendmsg_locked,
+	.sendpage_locked   = tcp_sendpage_locked,
+	.peek_len	   = tcp_peek_len,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	   = inet_compat_ioctl,
+#endif
+	.set_rcvlowat	   = tcp_set_rcvlowat,
+};
+EXPORT_SYMBOL(inet_stream_ops);
+
+const struct proto_ops inet_dgram_ops = {
+	.family		   = PF_INET,
+	.owner		   = THIS_MODULE,
+	.release	   = inet_release,
+	.bind		   = inet_bind,
+	.connect	   = inet_dgram_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = sock_no_accept,
+	.getname	   = inet_getname,
+	.poll		   = udp_poll,
+	.ioctl		   = inet_ioctl,
+	.gettstamp	   = sock_gettstamp,
+	.listen		   = sock_no_listen,
+	.shutdown	   = inet_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = inet_sendmsg,
+	.recvmsg	   = inet_recvmsg,
+	.mmap		   = sock_no_mmap,
+	.sendpage	   = inet_sendpage,
+	.set_peek_off	   = sk_set_peek_off,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	   = inet_compat_ioctl,
+#endif
+};
+EXPORT_SYMBOL(inet_dgram_ops);
+
+/*
+ * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
+ * udp_poll
+ */
+static const struct proto_ops inet_sockraw_ops = {
+	.family		   = PF_INET,
+	.owner		   = THIS_MODULE,
+	.release	   = inet_release,
+	.bind		   = inet_bind,
+	.connect	   = inet_dgram_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = sock_no_accept,
+	.getname	   = inet_getname,
+	.poll		   = datagram_poll,
+	.ioctl		   = inet_ioctl,
+	.gettstamp	   = sock_gettstamp,
+	.listen		   = sock_no_listen,
+	.shutdown	   = inet_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = inet_sendmsg,
+	.recvmsg	   = inet_recvmsg,
+	.mmap		   = sock_no_mmap,
+	.sendpage	   = inet_sendpage,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	   = inet_compat_ioctl,
+#endif
+};
+
+static const struct net_proto_family inet_family_ops = {
+	.family = PF_INET,
+	.create = inet_create,
+	.owner	= THIS_MODULE,
+};
+
+/* Upon startup we insert all the elements in inetsw_array[] into
+ * the linked list inetsw.
+ */
+static struct inet_protosw inetsw_array[] =
+{
+	{
+		.type =       SOCK_STREAM,
+		.protocol =   IPPROTO_TCP,
+		.prot =       &tcp_prot,
+		.ops =        &inet_stream_ops,
+		.flags =      INET_PROTOSW_PERMANENT |
+			      INET_PROTOSW_ICSK,
+	},
+
+	{
+		.type =       SOCK_DGRAM,
+		.protocol =   IPPROTO_UDP,
+		.prot =       &udp_prot,
+		.ops =        &inet_dgram_ops,
+		.flags =      INET_PROTOSW_PERMANENT,
+       },
+
+       {
+		.type =       SOCK_DGRAM,
+		.protocol =   IPPROTO_ICMP,
+		.prot =       &ping_prot,
+		.ops =        &inet_sockraw_ops,
+		.flags =      INET_PROTOSW_REUSE,
+       },
+
+       {
+	       .type =       SOCK_RAW,
+	       .protocol =   IPPROTO_IP,	/* wild card */
+	       .prot =       &raw_prot,
+	       .ops =        &inet_sockraw_ops,
+	       .flags =      INET_PROTOSW_REUSE,
+       }
+};
+
+#define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
+
+void inet_register_protosw(struct inet_protosw *p)
+{
+	struct list_head *lh;
+	struct inet_protosw *answer;
+	int protocol = p->protocol;
+	struct list_head *last_perm;
+
+	spin_lock_bh(&inetsw_lock);
+
+	if (p->type >= SOCK_MAX)
+		goto out_illegal;
+
+	/* If we are trying to override a permanent protocol, bail. */
+	last_perm = &inetsw[p->type];
+	list_for_each(lh, &inetsw[p->type]) {
+		answer = list_entry(lh, struct inet_protosw, list);
+		/* Check only the non-wild match. */
+		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
+			break;
+		if (protocol == answer->protocol)
+			goto out_permanent;
+		last_perm = lh;
+	}
+
+	/* Add the new entry after the last permanent entry if any, so that
+	 * the new entry does not override a permanent entry when matched with
+	 * a wild-card protocol. But it is allowed to override any existing
+	 * non-permanent entry.  This means that when we remove this entry, the
+	 * system automatically returns to the old behavior.
+	 */
+	list_add_rcu(&p->list, last_perm);
+out:
+	spin_unlock_bh(&inetsw_lock);
+
+	return;
+
+out_permanent:
+	pr_err("Attempt to override permanent protocol %d\n", protocol);
+	goto out;
+
+out_illegal:
+	pr_err("Ignoring attempt to register invalid socket type %d\n",
+	       p->type);
+	goto out;
+}
+EXPORT_SYMBOL(inet_register_protosw);
+
+void inet_unregister_protosw(struct inet_protosw *p)
+{
+	if (INET_PROTOSW_PERMANENT & p->flags) {
+		pr_err("Attempt to unregister permanent protocol %d\n",
+		       p->protocol);
+	} else {
+		spin_lock_bh(&inetsw_lock);
+		list_del_rcu(&p->list);
+		spin_unlock_bh(&inetsw_lock);
+
+		synchronize_net();
+	}
+}
+EXPORT_SYMBOL(inet_unregister_protosw);
+
+static int inet_sk_reselect_saddr(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	__be32 old_saddr = inet->inet_saddr;
+	__be32 daddr = inet->inet_daddr;
+	struct flowi4 *fl4;
+	struct rtable *rt;
+	__be32 new_saddr;
+	struct ip_options_rcu *inet_opt;
+
+	inet_opt = rcu_dereference_protected(inet->inet_opt,
+					     lockdep_sock_is_held(sk));
+	if (inet_opt && inet_opt->opt.srr)
+		daddr = inet_opt->opt.faddr;
+
+	/* Query new route. */
+	fl4 = &inet->cork.fl.u.ip4;
+	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
+			      sk->sk_bound_dev_if, sk->sk_protocol,
+			      inet->inet_sport, inet->inet_dport, sk);
+	if (IS_ERR(rt))
+		return PTR_ERR(rt);
+
+	sk_setup_caps(sk, &rt->dst);
+
+	new_saddr = fl4->saddr;
+
+	if (new_saddr == old_saddr)
+		return 0;
+
+	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
+		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
+			__func__, &old_saddr, &new_saddr);
+	}
+
+	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
+
+	/*
+	 * XXX The only one ugly spot where we need to
+	 * XXX really change the sockets identity after
+	 * XXX it has entered the hashes. -DaveM
+	 *
+	 * Besides that, it does not check for connection
+	 * uniqueness. Wait for troubles.
+	 */
+	return __sk_prot_rehash(sk);
+}
+
+int inet_sk_rebuild_header(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
+	__be32 daddr;
+	struct ip_options_rcu *inet_opt;
+	struct flowi4 *fl4;
+	int err;
+
+	/* Route is OK, nothing to do. */
+	if (rt)
+		return 0;
+
+	/* Reroute. */
+	rcu_read_lock();
+	inet_opt = rcu_dereference(inet->inet_opt);
+	daddr = inet->inet_daddr;
+	if (inet_opt && inet_opt->opt.srr)
+		daddr = inet_opt->opt.faddr;
+	rcu_read_unlock();
+	fl4 = &inet->cork.fl.u.ip4;
+	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
+				   inet->inet_dport, inet->inet_sport,
+				   sk->sk_protocol, RT_CONN_FLAGS(sk),
+				   sk->sk_bound_dev_if);
+	if (!IS_ERR(rt)) {
+		err = 0;
+		sk_setup_caps(sk, &rt->dst);
+	} else {
+		err = PTR_ERR(rt);
+
+		/* Routing failed... */
+		sk->sk_route_caps = 0;
+		/*
+		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
+		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
+		 */
+		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
+		    sk->sk_state != TCP_SYN_SENT ||
+		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
+		    (err = inet_sk_reselect_saddr(sk)) != 0)
+			sk->sk_err_soft = -err;
+	}
+
+	return err;
+}
+EXPORT_SYMBOL(inet_sk_rebuild_header);
+
+void inet_sk_set_state(struct sock *sk, int state)
+{
+	trace_inet_sock_set_state(sk, sk->sk_state, state);
+	sk->sk_state = state;
+}
+EXPORT_SYMBOL(inet_sk_set_state);
+
+void inet_sk_state_store(struct sock *sk, int newstate)
+{
+	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
+	smp_store_release(&sk->sk_state, newstate);
+}
+
+struct sk_buff *inet_gso_segment(struct sk_buff *skb,
+				 netdev_features_t features)
+{
+	bool udpfrag = false, fixedid = false, gso_partial, encap;
+	struct sk_buff *segs = ERR_PTR(-EINVAL);
+	const struct net_offload *ops;
+	unsigned int offset = 0;
+	struct iphdr *iph;
+	int proto, tot_len;
+	int nhoff;
+	int ihl;
+	int id;
+
+	skb_reset_network_header(skb);
+	nhoff = skb_network_header(skb) - skb_mac_header(skb);
+	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
+		goto out;
+
+	iph = ip_hdr(skb);
+	ihl = iph->ihl * 4;
+	if (ihl < sizeof(*iph))
+		goto out;
+
+	id = ntohs(iph->id);
+	proto = iph->protocol;
+
+	/* Warning: after this point, iph might be no longer valid */
+	if (unlikely(!pskb_may_pull(skb, ihl)))
+		goto out;
+	__skb_pull(skb, ihl);
+
+	encap = SKB_GSO_CB(skb)->encap_level > 0;
+	if (encap)
+		features &= skb->dev->hw_enc_features;
+	SKB_GSO_CB(skb)->encap_level += ihl;
+
+	skb_reset_transport_header(skb);
+
+	segs = ERR_PTR(-EPROTONOSUPPORT);
+
+	if (!skb->encapsulation || encap) {
+		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
+		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
+
+		/* fixed ID is invalid if DF bit is not set */
+		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
+			goto out;
+	}
+
+	ops = rcu_dereference(inet_offloads[proto]);
+	if (likely(ops && ops->callbacks.gso_segment)) {
+		segs = ops->callbacks.gso_segment(skb, features);
+		if (!segs)
+			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
+	}
+
+	if (IS_ERR_OR_NULL(segs))
+		goto out;
+
+	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
+
+	skb = segs;
+	do {
+		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
+		if (udpfrag) {
+			iph->frag_off = htons(offset >> 3);
+			if (skb->next)
+				iph->frag_off |= htons(IP_MF);
+			offset += skb->len - nhoff - ihl;
+			tot_len = skb->len - nhoff;
+		} else if (skb_is_gso(skb)) {
+			if (!fixedid) {
+				iph->id = htons(id);
+				id += skb_shinfo(skb)->gso_segs;
+			}
+
+			if (gso_partial)
+				tot_len = skb_shinfo(skb)->gso_size +
+					  SKB_GSO_CB(skb)->data_offset +
+					  skb->head - (unsigned char *)iph;
+			else
+				tot_len = skb->len - nhoff;
+		} else {
+			if (!fixedid)
+				iph->id = htons(id++);
+			tot_len = skb->len - nhoff;
+		}
+		iph->tot_len = htons(tot_len);
+		ip_send_check(iph);
+		if (encap)
+			skb_reset_inner_headers(skb);
+		skb->network_header = (u8 *)iph - skb->head;
+		skb_reset_mac_len(skb);
+	} while ((skb = skb->next));
+
+out:
+	return segs;
+}
+EXPORT_SYMBOL(inet_gso_segment);
+
+static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
+					netdev_features_t features)
+{
+	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
+		return ERR_PTR(-EINVAL);
+
+	return inet_gso_segment(skb, features);
+}
+
+struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
+{
+	const struct net_offload *ops;
+	struct sk_buff *pp = NULL;
+	const struct iphdr *iph;
+	struct sk_buff *p;
+	unsigned int hlen;
+	unsigned int off;
+	unsigned int id;
+	int flush = 1;
+	int proto;
+
+	off = skb_gro_offset(skb);
+	hlen = off + sizeof(*iph);
+	iph = skb_gro_header_fast(skb, off);
+	if (skb_gro_header_hard(skb, hlen)) {
+		iph = skb_gro_header_slow(skb, hlen, off);
+		if (unlikely(!iph))
+			goto out;
+	}
+
+	proto = iph->protocol;
+
+	rcu_read_lock();
+	ops = rcu_dereference(inet_offloads[proto]);
+	if (!ops || !ops->callbacks.gro_receive)
+		goto out_unlock;
+
+	if (*(u8 *)iph != 0x45)
+		goto out_unlock;
+
+	if (ip_is_fragment(iph))
+		goto out_unlock;
+
+	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
+		goto out_unlock;
+
+	id = ntohl(*(__be32 *)&iph->id);
+	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
+	id >>= 16;
+
+	list_for_each_entry(p, head, list) {
+		struct iphdr *iph2;
+		u16 flush_id;
+
+		if (!NAPI_GRO_CB(p)->same_flow)
+			continue;
+
+		iph2 = (struct iphdr *)(p->data + off);
+		/* The above works because, with the exception of the top
+		 * (inner most) layer, we only aggregate pkts with the same
+		 * hdr length so all the hdrs we'll need to verify will start
+		 * at the same offset.
+		 */
+		if ((iph->protocol ^ iph2->protocol) |
+		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
+		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
+			NAPI_GRO_CB(p)->same_flow = 0;
+			continue;
+		}
+
+		/* All fields must match except length and checksum. */
+		NAPI_GRO_CB(p)->flush |=
+			(iph->ttl ^ iph2->ttl) |
+			(iph->tos ^ iph2->tos) |
+			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
+
+		NAPI_GRO_CB(p)->flush |= flush;
+
+		/* We need to store of the IP ID check to be included later
+		 * when we can verify that this packet does in fact belong
+		 * to a given flow.
+		 */
+		flush_id = (u16)(id - ntohs(iph2->id));
+
+		/* This bit of code makes it much easier for us to identify
+		 * the cases where we are doing atomic vs non-atomic IP ID
+		 * checks.  Specifically an atomic check can return IP ID
+		 * values 0 - 0xFFFF, while a non-atomic check can only
+		 * return 0 or 0xFFFF.
+		 */
+		if (!NAPI_GRO_CB(p)->is_atomic ||
+		    !(iph->frag_off & htons(IP_DF))) {
+			flush_id ^= NAPI_GRO_CB(p)->count;
+			flush_id = flush_id ? 0xFFFF : 0;
+		}
+
+		/* If the previous IP ID value was based on an atomic
+		 * datagram we can overwrite the value and ignore it.
+		 */
+		if (NAPI_GRO_CB(skb)->is_atomic)
+			NAPI_GRO_CB(p)->flush_id = flush_id;
+		else
+			NAPI_GRO_CB(p)->flush_id |= flush_id;
+	}
+
+	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
+	NAPI_GRO_CB(skb)->flush |= flush;
+	skb_set_network_header(skb, off);
+	/* The above will be needed by the transport layer if there is one
+	 * immediately following this IP hdr.
+	 */
+
+	/* Note : No need to call skb_gro_postpull_rcsum() here,
+	 * as we already checked checksum over ipv4 header was 0
+	 */
+	skb_gro_pull(skb, sizeof(*iph));
+	skb_set_transport_header(skb, skb_gro_offset(skb));
+
+	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
+				       ops->callbacks.gro_receive, head, skb);
+
+out_unlock:
+	rcu_read_unlock();
+
+out:
+	skb_gro_flush_final(skb, pp, flush);
+
+	return pp;
+}
+EXPORT_SYMBOL(inet_gro_receive);
+
+static struct sk_buff *ipip_gro_receive(struct list_head *head,
+					struct sk_buff *skb)
+{
+	if (NAPI_GRO_CB(skb)->encap_mark) {
+		NAPI_GRO_CB(skb)->flush = 1;
+		return NULL;
+	}
+
+	NAPI_GRO_CB(skb)->encap_mark = 1;
+
+	return inet_gro_receive(head, skb);
+}
+
+#define SECONDS_PER_DAY	86400
+
+/* inet_current_timestamp - Return IP network timestamp
+ *
+ * Return milliseconds since midnight in network byte order.
+ */
+__be32 inet_current_timestamp(void)
+{
+	u32 secs;
+	u32 msecs;
+	struct timespec64 ts;
+
+	ktime_get_real_ts64(&ts);
+
+	/* Get secs since midnight. */
+	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
+	/* Convert to msecs. */
+	msecs = secs * MSEC_PER_SEC;
+	/* Convert nsec to msec. */
+	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
+
+	/* Convert to network byte order. */
+	return htonl(msecs);
+}
+EXPORT_SYMBOL(inet_current_timestamp);
+
+int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
+{
+	if (sk->sk_family == AF_INET)
+		return ip_recv_error(sk, msg, len, addr_len);
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == AF_INET6)
+		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
+#endif
+	return -EINVAL;
+}
+
+int inet_gro_complete(struct sk_buff *skb, int nhoff)
+{
+	__be16 newlen = htons(skb->len - nhoff);
+	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
+	const struct net_offload *ops;
+	int proto = iph->protocol;
+	int err = -ENOSYS;
+
+	if (skb->encapsulation) {
+		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
+		skb_set_inner_network_header(skb, nhoff);
+	}
+
+	csum_replace2(&iph->check, iph->tot_len, newlen);
+	iph->tot_len = newlen;
+
+	rcu_read_lock();
+	ops = rcu_dereference(inet_offloads[proto]);
+	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
+		goto out_unlock;
+
+	/* Only need to add sizeof(*iph) to get to the next hdr below
+	 * because any hdr with option will have been flushed in
+	 * inet_gro_receive().
+	 */
+	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
+			      tcp4_gro_complete, udp4_gro_complete,
+			      skb, nhoff + sizeof(*iph));
+
+out_unlock:
+	rcu_read_unlock();
+
+	return err;
+}
+EXPORT_SYMBOL(inet_gro_complete);
+
+static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
+{
+	skb->encapsulation = 1;
+	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
+	return inet_gro_complete(skb, nhoff);
+}
+
+int inet_ctl_sock_create(struct sock **sk, unsigned short family,
+			 unsigned short type, unsigned char protocol,
+			 struct net *net)
+{
+	struct socket *sock;
+	int rc = sock_create_kern(net, family, type, protocol, &sock);
+
+	if (rc == 0) {
+		*sk = sock->sk;
+		(*sk)->sk_allocation = GFP_ATOMIC;
+		/*
+		 * Unhash it so that IP input processing does not even see it,
+		 * we do not wish this socket to see incoming packets.
+		 */
+		(*sk)->sk_prot->unhash(*sk);
+	}
+	return rc;
+}
+EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
+
+u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
+{
+	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
+}
+EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
+
+unsigned long snmp_fold_field(void __percpu *mib, int offt)
+{
+	unsigned long res = 0;
+	int i;
+
+	for_each_possible_cpu(i)
+		res += snmp_get_cpu_field(mib, i, offt);
+	return res;
+}
+EXPORT_SYMBOL_GPL(snmp_fold_field);
+
+#if BITS_PER_LONG==32
+
+u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
+			 size_t syncp_offset)
+{
+	void *bhptr;
+	struct u64_stats_sync *syncp;
+	u64 v;
+	unsigned int start;
+
+	bhptr = per_cpu_ptr(mib, cpu);
+	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
+	do {
+		start = u64_stats_fetch_begin_irq(syncp);
+		v = *(((u64 *)bhptr) + offt);
+	} while (u64_stats_fetch_retry_irq(syncp, start));
+
+	return v;
+}
+EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
+
+u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
+{
+	u64 res = 0;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
+	}
+	return res;
+}
+EXPORT_SYMBOL_GPL(snmp_fold_field64);
+#endif
+
+#ifdef CONFIG_IP_MULTICAST
+static const struct net_protocol igmp_protocol = {
+	.handler =	igmp_rcv,
+	.netns_ok =	1,
+};
+#endif
+
+static const struct net_protocol tcp_protocol = {
+	.handler	=	tcp_v4_rcv,
+	.err_handler	=	tcp_v4_err,
+	.no_policy	=	1,
+	.netns_ok	=	1,
+	.icmp_strict_tag_validation = 1,
+};
+
+static const struct net_protocol udp_protocol = {
+	.handler =	udp_rcv,
+	.err_handler =	udp_err,
+	.no_policy =	1,
+	.netns_ok =	1,
+};
+
+static const struct net_protocol icmp_protocol = {
+	.handler =	icmp_rcv,
+	.err_handler =	icmp_err,
+	.no_policy =	1,
+	.netns_ok =	1,
+};
+
+static __net_init int ipv4_mib_init_net(struct net *net)
+{
+	int i;
+
+	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
+	if (!net->mib.tcp_statistics)
+		goto err_tcp_mib;
+	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
+	if (!net->mib.ip_statistics)
+		goto err_ip_mib;
+
+	for_each_possible_cpu(i) {
+		struct ipstats_mib *af_inet_stats;
+		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
+		u64_stats_init(&af_inet_stats->syncp);
+	}
+
+	net->mib.net_statistics = alloc_percpu(struct linux_mib);
+	if (!net->mib.net_statistics)
+		goto err_net_mib;
+	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
+	if (!net->mib.udp_statistics)
+		goto err_udp_mib;
+	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
+	if (!net->mib.udplite_statistics)
+		goto err_udplite_mib;
+	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
+	if (!net->mib.icmp_statistics)
+		goto err_icmp_mib;
+	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
+					      GFP_KERNEL);
+	if (!net->mib.icmpmsg_statistics)
+		goto err_icmpmsg_mib;
+
+	tcp_mib_init(net);
+	return 0;
+
+err_icmpmsg_mib:
+	free_percpu(net->mib.icmp_statistics);
+err_icmp_mib:
+	free_percpu(net->mib.udplite_statistics);
+err_udplite_mib:
+	free_percpu(net->mib.udp_statistics);
+err_udp_mib:
+	free_percpu(net->mib.net_statistics);
+err_net_mib:
+	free_percpu(net->mib.ip_statistics);
+err_ip_mib:
+	free_percpu(net->mib.tcp_statistics);
+err_tcp_mib:
+	return -ENOMEM;
+}
+
+static __net_exit void ipv4_mib_exit_net(struct net *net)
+{
+	kfree(net->mib.icmpmsg_statistics);
+	free_percpu(net->mib.icmp_statistics);
+	free_percpu(net->mib.udplite_statistics);
+	free_percpu(net->mib.udp_statistics);
+	free_percpu(net->mib.net_statistics);
+	free_percpu(net->mib.ip_statistics);
+	free_percpu(net->mib.tcp_statistics);
+#ifdef CONFIG_MPTCP
+	/* allocated on demand, see mptcp_init_sock() */
+	free_percpu(net->mib.mptcp_statistics);
+#endif
+}
+
+static __net_initdata struct pernet_operations ipv4_mib_ops = {
+	.init = ipv4_mib_init_net,
+	.exit = ipv4_mib_exit_net,
+};
+
+static int __init init_ipv4_mibs(void)
+{
+	return register_pernet_subsys(&ipv4_mib_ops);
+}
+
+static __net_init int inet_init_net(struct net *net)
+{
+	/*
+	 * Set defaults for local port range
+	 */
+	seqlock_init(&net->ipv4.ip_local_ports.lock);
+	net->ipv4.ip_local_ports.range[0] =  32768;
+	net->ipv4.ip_local_ports.range[1] =  60999;
+
+	seqlock_init(&net->ipv4.ping_group_range.lock);
+	/*
+	 * Sane defaults - nobody may create ping sockets.
+	 * Boot scripts should set this to distro-specific group.
+	 */
+	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
+	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
+
+	/* Default values for sysctl-controlled parameters.
+	 * We set them here, in case sysctl is not compiled.
+	 */
+	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
+	net->ipv4.sysctl_ip_fwd_update_priority = 1;
+	net->ipv4.sysctl_ip_dynaddr = 0;
+	net->ipv4.sysctl_ip_early_demux = 1;
+	net->ipv4.sysctl_udp_early_demux = 1;
+	net->ipv4.sysctl_tcp_early_demux = 1;
+	net->ipv4.sysctl_nexthop_compat_mode = 1;
+#ifdef CONFIG_SYSCTL
+	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
+#endif
+
+	/* Some igmp sysctl, whose values are always used */
+	net->ipv4.sysctl_igmp_max_memberships = 20;
+	net->ipv4.sysctl_igmp_max_msf = 10;
+	/* IGMP reports for link-local multicast groups are enabled by default */
+	net->ipv4.sysctl_igmp_llm_reports = 1;
+	net->ipv4.sysctl_igmp_qrv = 2;
+
+	return 0;
+}
+
+static __net_initdata struct pernet_operations af_inet_ops = {
+	.init = inet_init_net,
+};
+
+static int __init init_inet_pernet_ops(void)
+{
+	return register_pernet_subsys(&af_inet_ops);
+}
+
+static int ipv4_proc_init(void);
+
+/*
+ *	IP protocol layer initialiser
+ */
+
+static struct packet_offload ip_packet_offload __read_mostly = {
+	.type = cpu_to_be16(ETH_P_IP),
+	.callbacks = {
+		.gso_segment = inet_gso_segment,
+		.gro_receive = inet_gro_receive,
+		.gro_complete = inet_gro_complete,
+	},
+};
+
+static const struct net_offload ipip_offload = {
+	.callbacks = {
+		.gso_segment	= ipip_gso_segment,
+		.gro_receive	= ipip_gro_receive,
+		.gro_complete	= ipip_gro_complete,
+	},
+};
+
+static int __init ipip_offload_init(void)
+{
+	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
+}
+
+static int __init ipv4_offload_init(void)
+{
+	/*
+	 * Add offloads
+	 */
+	if (udpv4_offload_init() < 0)
+		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
+	if (tcpv4_offload_init() < 0)
+		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
+	if (ipip_offload_init() < 0)
+		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
+
+	dev_add_offload(&ip_packet_offload);
+	return 0;
+}
+
+fs_initcall(ipv4_offload_init);
+
+static struct packet_type ip_packet_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_IP),
+	.func = ip_rcv,
+	.list_func = ip_list_rcv,
+};
+
+static int __init inet_init(void)
+{
+	struct inet_protosw *q;
+	struct list_head *r;
+	int rc;
+
+	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
+
+	rc = proto_register(&tcp_prot, 1);
+	if (rc)
+		goto out;
+
+	rc = proto_register(&udp_prot, 1);
+	if (rc)
+		goto out_unregister_tcp_proto;
+
+	rc = proto_register(&raw_prot, 1);
+	if (rc)
+		goto out_unregister_udp_proto;
+
+	rc = proto_register(&ping_prot, 1);
+	if (rc)
+		goto out_unregister_raw_proto;
+
+	/*
+	 *	Tell SOCKET that we are alive...
+	 */
+
+	(void)sock_register(&inet_family_ops);
+
+#ifdef CONFIG_SYSCTL
+	ip_static_sysctl_init();
+#endif
+
+	/*
+	 *	Add all the base protocols.
+	 */
+
+	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
+		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
+	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
+		pr_crit("%s: Cannot add UDP protocol\n", __func__);
+	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
+		pr_crit("%s: Cannot add TCP protocol\n", __func__);
+#ifdef CONFIG_IP_MULTICAST
+	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
+		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
+#endif
+
+	/* Register the socket-side information for inet_create. */
+	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
+		INIT_LIST_HEAD(r);
+
+	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
+		inet_register_protosw(q);
+
+	/*
+	 *	Set the ARP module up
+	 */
+
+	arp_init();
+
+	/*
+	 *	Set the IP module up
+	 */
+
+	ip_init();
+
+	/* Initialise per-cpu ipv4 mibs */
+	if (init_ipv4_mibs())
+		panic("%s: Cannot init ipv4 mibs\n", __func__);
+
+	/* Setup TCP slab cache for open requests. */
+	tcp_init();
+
+	/* Setup UDP memory threshold */
+	udp_init();
+
+	/* Add UDP-Lite (RFC 3828) */
+	udplite4_register();
+
+	raw_init();
+
+	ping_init();
+
+	/*
+	 *	Set the ICMP layer up
+	 */
+
+	if (icmp_init() < 0)
+		panic("Failed to create the ICMP control socket.\n");
+
+	/*
+	 *	Initialise the multicast router
+	 */
+#if defined(CONFIG_IP_MROUTE)
+	if (ip_mr_init())
+		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
+#endif
+
+	if (init_inet_pernet_ops())
+		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
+
+	ipv4_proc_init();
+
+	ipfrag_init();
+
+	dev_add_pack(&ip_packet_type);
+
+	ip_tunnel_core_init();
+
+	rc = 0;
+out:
+	return rc;
+out_unregister_raw_proto:
+	proto_unregister(&raw_prot);
+out_unregister_udp_proto:
+	proto_unregister(&udp_prot);
+out_unregister_tcp_proto:
+	proto_unregister(&tcp_prot);
+	goto out;
+}
+
+fs_initcall(inet_init);
+
+/* ------------------------------------------------------------------------ */
+
+#ifdef CONFIG_PROC_FS
+static int __init ipv4_proc_init(void)
+{
+	int rc = 0;
+
+	if (raw_proc_init())
+		goto out_raw;
+	if (tcp4_proc_init())
+		goto out_tcp;
+	if (udp4_proc_init())
+		goto out_udp;
+	if (ping_proc_init())
+		goto out_ping;
+	if (ip_misc_proc_init())
+		goto out_misc;
+out:
+	return rc;
+out_misc:
+	ping_proc_exit();
+out_ping:
+	udp4_proc_exit();
+out_udp:
+	tcp4_proc_exit();
+out_tcp:
+	raw_proc_exit();
+out_raw:
+	rc = -ENOMEM;
+	goto out;
+}
+
+#else /* CONFIG_PROC_FS */
+static int __init ipv4_proc_init(void)
+{
+	return 0;
+}
+#endif /* CONFIG_PROC_FS */