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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/net/ipv4/af_inet.c

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33 KiB
C
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/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* PF_INET protocol family socket handler.
*
* Version: $Id: af_inet.c,v 1.137 2002/02/01 22:01:03 davem Exp $
*
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Florian La Roche, <flla@stud.uni-sb.de>
* Alan Cox, <A.Cox@swansea.ac.uk>
*
* 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.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/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 <asm/uaccess.h>
#include <asm/system.h>
#include <linux/smp_lock.h>
#include <linux/inet.h>
#include <linux/igmp.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.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 <linux/skbuff.h>
#include <net/sock.h>
#include <net/raw.h>
#include <net/icmp.h>
#include <net/ipip.h>
#include <net/inet_common.h>
#include <net/xfrm.h>
#ifdef CONFIG_IP_MROUTE
#include <linux/mroute.h>
#endif
DEFINE_SNMP_STAT(struct linux_mib, net_statistics) __read_mostly;
extern void ip_mc_drop_socket(struct sock *sk);
/* 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);
__skb_queue_purge(&sk->sk_error_queue);
if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
printk("Attempt to release TCP socket in state %d %p\n",
sk->sk_state, sk);
return;
}
if (!sock_flag(sk, SOCK_DEAD)) {
printk("Attempt to release alive inet socket %p\n", sk);
return;
}
BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
BUG_TRAP(!sk->sk_wmem_queued);
BUG_TRAP(!sk->sk_forward_alloc);
kfree(inet->opt);
dst_release(sk->sk_dst_cache);
sk_refcnt_debug_dec(sk);
}
/*
* 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->num) {
if (sk->sk_prot->get_port(sk, 0)) {
release_sock(sk);
return -EAGAIN;
}
inet->sport = htons(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;
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;
/* Really, if the socket is already in listen state
* we can only allow the backlog to be adjusted.
*/
if (old_state != TCP_LISTEN) {
err = inet_csk_listen_start(sk, backlog);
if (err)
goto out;
}
sk->sk_max_ack_backlog = backlog;
err = 0;
out:
release_sock(sk);
return err;
}
/*
* Create an inet socket.
*/
static int inet_create(struct socket *sock, int protocol)
{
struct sock *sk;
struct list_head *p;
struct inet_protosw *answer;
struct inet_sock *inet;
struct proto *answer_prot;
unsigned char answer_flags;
char answer_no_check;
int try_loading_module = 0;
int err;
sock->state = SS_UNCONNECTED;
/* Look for the requested type/protocol pair. */
answer = NULL;
lookup_protocol:
err = -ESOCKTNOSUPPORT;
rcu_read_lock();
list_for_each_rcu(p, &inetsw[sock->type]) {
answer = list_entry(p, struct inet_protosw, list);
/* 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;
answer = NULL;
}
if (unlikely(answer == NULL)) {
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 (answer->capability > 0 && !capable(answer->capability))
goto out_rcu_unlock;
sock->ops = answer->ops;
answer_prot = answer->prot;
answer_no_check = answer->no_check;
answer_flags = answer->flags;
rcu_read_unlock();
BUG_TRAP(answer_prot->slab != NULL);
err = -ENOBUFS;
sk = sk_alloc(PF_INET, GFP_KERNEL, answer_prot, 1);
if (sk == NULL)
goto out;
err = 0;
sk->sk_no_check = answer_no_check;
if (INET_PROTOSW_REUSE & answer_flags)
sk->sk_reuse = 1;
inet = inet_sk(sk);
inet->is_icsk = INET_PROTOSW_ICSK & answer_flags;
if (SOCK_RAW == sock->type) {
inet->num = protocol;
if (IPPROTO_RAW == protocol)
inet->hdrincl = 1;
}
if (ipv4_config.no_pmtu_disc)
inet->pmtudisc = IP_PMTUDISC_DONT;
else
inet->pmtudisc = IP_PMTUDISC_WANT;
inet->id = 0;
sock_init_data(sock, sk);
sk->sk_destruct = inet_sock_destruct;
sk->sk_family = PF_INET;
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_index = 0;
inet->mc_list = NULL;
sk_refcnt_debug_inc(sk);
if (inet->num) {
/* It assumes that any protocol which allows
* the user to assign a number at socket
* creation time automatically
* shares.
*/
inet->sport = htons(inet->num);
/* Add to protocol hash chains. */
sk->sk_prot->hash(sk);
}
if (sk->sk_prot->init) {
err = sk->sk_prot->init(sk);
if (err)
sk_common_release(sk);
}
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;
/* 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;
sock->sk = NULL;
sk->sk_prot->close(sk, timeout);
}
return 0;
}
/* It is off by default, see below. */
int sysctl_ip_nonlocal_bind __read_mostly;
int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
struct sock *sk = sock->sk;
struct inet_sock *inet = inet_sk(sk);
unsigned short snum;
int chk_addr_ret;
int err;
/* If the socket has its own bind function then use it. (RAW) */
if (sk->sk_prot->bind) {
err = sk->sk_prot->bind(sk, uaddr, addr_len);
goto out;
}
err = -EINVAL;
if (addr_len < sizeof(struct sockaddr_in))
goto out;
chk_addr_ret = inet_addr_type(addr->sin_addr.s_addr);
/* 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 (!sysctl_ip_nonlocal_bind &&
!inet->freebind &&
addr->sin_addr.s_addr != 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 && snum < PROT_SOCK && !capable(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.
*/
lock_sock(sk);
/* Check these errors (active socket, double bind). */
err = -EINVAL;
if (sk->sk_state != TCP_CLOSE || inet->num)
goto out_release_sock;
inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr;
if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
inet->saddr = 0; /* Use device */
/* Make sure we are allowed to bind here. */
if (sk->sk_prot->get_port(sk, snum)) {
inet->saddr = inet->rcv_saddr = 0;
err = -EADDRINUSE;
goto out_release_sock;
}
if (inet->rcv_saddr)
sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
if (snum)
sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
inet->sport = htons(inet->num);
inet->daddr = 0;
inet->dport = 0;
sk_dst_reset(sk);
err = 0;
out_release_sock:
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;
if (uaddr->sa_family == AF_UNSPEC)
return sk->sk_prot->disconnect(sk, flags);
if (!inet_sk(sk)->num && inet_autobind(sk))
return -EAGAIN;
return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
}
static long inet_wait_for_connect(struct sock *sk, long timeo)
{
DEFINE_WAIT(wait);
prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
/* 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 = schedule_timeout(timeo);
lock_sock(sk);
if (signal_pending(current) || !timeo)
break;
prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
}
finish_wait(sk->sk_sleep, &wait);
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)
{
struct sock *sk = sock->sk;
int err;
long timeo;
lock_sock(sk);
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:
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;
err = sk->sk_prot->connect(sk, uaddr, addr_len);
if (err < 0)
goto out;
sock->state = SS_CONNECTING;
/* 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)) {
/* Error code is set above */
if (!timeo || !inet_wait_for_connect(sk, timeo))
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:
release_sock(sk);
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;
}
/*
* Accept a pending connection. The TCP layer now gives BSD semantics.
*/
int inet_accept(struct socket *sock, struct socket *newsock, int flags)
{
struct sock *sk1 = sock->sk;
int err = -EINVAL;
struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
if (!sk2)
goto do_err;
lock_sock(sk2);
BUG_TRAP((1 << sk2->sk_state) &
(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE));
sock_graft(sk2, newsock);
newsock->state = SS_CONNECTED;
err = 0;
release_sock(sk2);
do_err:
return err;
}
/*
* This does both peername and sockname.
*/
int inet_getname(struct socket *sock, struct sockaddr *uaddr,
int *uaddr_len, int peer)
{
struct sock *sk = sock->sk;
struct inet_sock *inet = inet_sk(sk);
struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
sin->sin_family = AF_INET;
if (peer) {
if (!inet->dport ||
(((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
peer == 1))
return -ENOTCONN;
sin->sin_port = inet->dport;
sin->sin_addr.s_addr = inet->daddr;
} else {
__u32 addr = inet->rcv_saddr;
if (!addr)
addr = inet->saddr;
sin->sin_port = inet->sport;
sin->sin_addr.s_addr = addr;
}
memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
*uaddr_len = sizeof(*sin);
return 0;
}
int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
size_t size)
{
struct sock *sk = sock->sk;
/* We may need to bind the socket. */
if (!inet_sk(sk)->num && inet_autobind(sk))
return -EAGAIN;
return sk->sk_prot->sendmsg(iocb, sk, msg, size);
}
static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
{
struct sock *sk = sock->sk;
/* We may need to bind the socket. */
if (!inet_sk(sk)->num && inet_autobind(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);
}
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
POLLHUP, even on eg. unconnected UDP sockets -- RR */
default:
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;
/* Fall through */
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;
}
/*
* 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;
switch (cmd) {
case SIOCGSTAMP:
err = sock_get_timestamp(sk, (struct timeval __user *)arg);
break;
case SIOCADDRT:
case SIOCDELRT:
case SIOCRTMSG:
err = ip_rt_ioctl(cmd, (void __user *)arg);
break;
case SIOCDARP:
case SIOCGARP:
case SIOCSARP:
err = arp_ioctl(cmd, (void __user *)arg);
break;
case SIOCGIFADDR:
case SIOCSIFADDR:
case SIOCGIFBRDADDR:
case SIOCSIFBRDADDR:
case SIOCGIFNETMASK:
case SIOCSIFNETMASK:
case SIOCGIFDSTADDR:
case SIOCSIFDSTADDR:
case SIOCSIFPFLAGS:
case SIOCGIFPFLAGS:
case SIOCSIFFLAGS:
err = devinet_ioctl(cmd, (void __user *)arg);
break;
default:
if (sk->sk_prot->ioctl)
err = sk->sk_prot->ioctl(sk, cmd, arg);
else
err = -ENOIOCTLCMD;
break;
}
return err;
}
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,
.listen = inet_listen,
.shutdown = inet_shutdown,
.setsockopt = sock_common_setsockopt,
.getsockopt = sock_common_getsockopt,
.sendmsg = inet_sendmsg,
.recvmsg = sock_common_recvmsg,
.mmap = sock_no_mmap,
.sendpage = tcp_sendpage,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_sock_common_setsockopt,
.compat_getsockopt = compat_sock_common_getsockopt,
#endif
};
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,
.listen = sock_no_listen,
.shutdown = inet_shutdown,
.setsockopt = sock_common_setsockopt,
.getsockopt = sock_common_getsockopt,
.sendmsg = inet_sendmsg,
.recvmsg = sock_common_recvmsg,
.mmap = sock_no_mmap,
.sendpage = inet_sendpage,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_sock_common_setsockopt,
.compat_getsockopt = compat_sock_common_getsockopt,
#endif
};
/*
* 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,
.listen = sock_no_listen,
.shutdown = inet_shutdown,
.setsockopt = sock_common_setsockopt,
.getsockopt = sock_common_getsockopt,
.sendmsg = inet_sendmsg,
.recvmsg = sock_common_recvmsg,
.mmap = sock_no_mmap,
.sendpage = inet_sendpage,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_sock_common_setsockopt,
.compat_getsockopt = compat_sock_common_getsockopt,
#endif
};
static 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,
.capability = -1,
.no_check = 0,
.flags = INET_PROTOSW_PERMANENT |
INET_PROTOSW_ICSK,
},
{
.type = SOCK_DGRAM,
.protocol = IPPROTO_UDP,
.prot = &udp_prot,
.ops = &inet_dgram_ops,
.capability = -1,
.no_check = UDP_CSUM_DEFAULT,
.flags = INET_PROTOSW_PERMANENT,
},
{
.type = SOCK_RAW,
.protocol = IPPROTO_IP, /* wild card */
.prot = &raw_prot,
.ops = &inet_sockraw_ops,
.capability = CAP_NET_RAW,
.no_check = UDP_CSUM_DEFAULT,
.flags = INET_PROTOSW_REUSE,
}
};
#define INETSW_ARRAY_LEN (sizeof(inetsw_array) / sizeof(struct inet_protosw))
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. */
answer = NULL;
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) {
if (protocol == answer->protocol)
break;
last_perm = lh;
}
answer = NULL;
}
if (answer)
goto out_permanent;
/* 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);
synchronize_net();
return;
out_permanent:
printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
protocol);
goto out;
out_illegal:
printk(KERN_ERR
"Ignoring attempt to register invalid socket type %d.\n",
p->type);
goto out;
}
void inet_unregister_protosw(struct inet_protosw *p)
{
if (INET_PROTOSW_PERMANENT & p->flags) {
printk(KERN_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();
}
}
/*
* Shall we try to damage output packets if routing dev changes?
*/
int sysctl_ip_dynaddr __read_mostly;
static int inet_sk_reselect_saddr(struct sock *sk)
{
struct inet_sock *inet = inet_sk(sk);
int err;
struct rtable *rt;
__u32 old_saddr = inet->saddr;
__u32 new_saddr;
__be32 daddr = inet->daddr;
if (inet->opt && inet->opt->srr)
daddr = inet->opt->faddr;
/* Query new route. */
err = ip_route_connect(&rt, daddr, 0,
RT_CONN_FLAGS(sk),
sk->sk_bound_dev_if,
sk->sk_protocol,
inet->sport, inet->dport, sk);
if (err)
return err;
sk_setup_caps(sk, &rt->u.dst);
new_saddr = rt->rt_src;
if (new_saddr == old_saddr)
return 0;
if (sysctl_ip_dynaddr > 1) {
printk(KERN_INFO "%s(): shifting inet->"
"saddr from %d.%d.%d.%d to %d.%d.%d.%d\n",
__FUNCTION__,
NIPQUAD(old_saddr),
NIPQUAD(new_saddr));
}
inet->saddr = 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.
*/
__sk_prot_rehash(sk);
return 0;
}
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;
int err;
/* Route is OK, nothing to do. */
if (rt)
return 0;
/* Reroute. */
daddr = inet->daddr;
if (inet->opt && inet->opt->srr)
daddr = inet->opt->faddr;
{
struct flowi fl = {
.oif = sk->sk_bound_dev_if,
.nl_u = {
.ip4_u = {
.daddr = daddr,
.saddr = inet->saddr,
.tos = RT_CONN_FLAGS(sk),
},
},
.proto = sk->sk_protocol,
.uli_u = {
.ports = {
.sport = inet->sport,
.dport = inet->dport,
},
},
};
security_sk_classify_flow(sk, &fl);
err = ip_route_output_flow(&rt, &fl, sk, 0);
}
if (!err)
sk_setup_caps(sk, &rt->u.dst);
else {
/* 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 (!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);
static int inet_gso_send_check(struct sk_buff *skb)
{
struct iphdr *iph;
struct net_protocol *ops;
int proto;
int ihl;
int err = -EINVAL;
if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
goto out;
iph = skb->nh.iph;
ihl = iph->ihl * 4;
if (ihl < sizeof(*iph))
goto out;
if (unlikely(!pskb_may_pull(skb, ihl)))
goto out;
skb->h.raw = __skb_pull(skb, ihl);
iph = skb->nh.iph;
proto = iph->protocol & (MAX_INET_PROTOS - 1);
err = -EPROTONOSUPPORT;
rcu_read_lock();
ops = rcu_dereference(inet_protos[proto]);
if (likely(ops && ops->gso_send_check))
err = ops->gso_send_check(skb);
rcu_read_unlock();
out:
return err;
}
static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
struct iphdr *iph;
struct net_protocol *ops;
int proto;
int ihl;
int id;
if (unlikely(skb_shinfo(skb)->gso_type &
~(SKB_GSO_TCPV4 |
SKB_GSO_UDP |
SKB_GSO_DODGY |
SKB_GSO_TCP_ECN |
0)))
goto out;
if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
goto out;
iph = skb->nh.iph;
ihl = iph->ihl * 4;
if (ihl < sizeof(*iph))
goto out;
if (unlikely(!pskb_may_pull(skb, ihl)))
goto out;
skb->h.raw = __skb_pull(skb, ihl);
iph = skb->nh.iph;
id = ntohs(iph->id);
proto = iph->protocol & (MAX_INET_PROTOS - 1);
segs = ERR_PTR(-EPROTONOSUPPORT);
rcu_read_lock();
ops = rcu_dereference(inet_protos[proto]);
if (likely(ops && ops->gso_segment))
segs = ops->gso_segment(skb, features);
rcu_read_unlock();
if (!segs || unlikely(IS_ERR(segs)))
goto out;
skb = segs;
do {
iph = skb->nh.iph;
iph->id = htons(id++);
iph->tot_len = htons(skb->len - skb->mac_len);
iph->check = 0;
iph->check = ip_fast_csum(skb->nh.raw, iph->ihl);
} while ((skb = skb->next));
out:
return segs;
}
#ifdef CONFIG_IP_MULTICAST
static struct net_protocol igmp_protocol = {
.handler = igmp_rcv,
};
#endif
static struct net_protocol tcp_protocol = {
.handler = tcp_v4_rcv,
.err_handler = tcp_v4_err,
.gso_send_check = tcp_v4_gso_send_check,
.gso_segment = tcp_tso_segment,
.no_policy = 1,
};
static struct net_protocol udp_protocol = {
.handler = udp_rcv,
.err_handler = udp_err,
.no_policy = 1,
};
static struct net_protocol icmp_protocol = {
.handler = icmp_rcv,
};
static int __init init_ipv4_mibs(void)
{
net_statistics[0] = alloc_percpu(struct linux_mib);
net_statistics[1] = alloc_percpu(struct linux_mib);
ip_statistics[0] = alloc_percpu(struct ipstats_mib);
ip_statistics[1] = alloc_percpu(struct ipstats_mib);
icmp_statistics[0] = alloc_percpu(struct icmp_mib);
icmp_statistics[1] = alloc_percpu(struct icmp_mib);
tcp_statistics[0] = alloc_percpu(struct tcp_mib);
tcp_statistics[1] = alloc_percpu(struct tcp_mib);
udp_statistics[0] = alloc_percpu(struct udp_mib);
udp_statistics[1] = alloc_percpu(struct udp_mib);
if (!
(net_statistics[0] && net_statistics[1] && ip_statistics[0]
&& ip_statistics[1] && tcp_statistics[0] && tcp_statistics[1]
&& udp_statistics[0] && udp_statistics[1]))
return -ENOMEM;
(void) tcp_mib_init();
return 0;
}
static int ipv4_proc_init(void);
/*
* IP protocol layer initialiser
*/
static struct packet_type ip_packet_type = {
.type = __constant_htons(ETH_P_IP),
.func = ip_rcv,
.gso_send_check = inet_gso_send_check,
.gso_segment = inet_gso_segment,
};
static int __init inet_init(void)
{
struct sk_buff *dummy_skb;
struct inet_protosw *q;
struct list_head *r;
int rc = -EINVAL;
BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
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;
/*
* Tell SOCKET that we are alive...
*/
(void)sock_register(&inet_family_ops);
/*
* Add all the base protocols.
*/
if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
#ifdef CONFIG_IP_MULTICAST
if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
#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();
tcp_v4_init(&inet_family_ops);
/* Setup TCP slab cache for open requests. */
tcp_init();
/*
* Set the ICMP layer up
*/
icmp_init(&inet_family_ops);
/*
* Initialise the multicast router
*/
#if defined(CONFIG_IP_MROUTE)
ip_mr_init();
#endif
/*
* Initialise per-cpu ipv4 mibs
*/
if(init_ipv4_mibs())
printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n"); ;
ipv4_proc_init();
ipfrag_init();
dev_add_pack(&ip_packet_type);
rc = 0;
out:
return rc;
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 (fib_proc_init())
goto out_fib;
if (ip_misc_proc_init())
goto out_misc;
out:
return rc;
out_misc:
fib_proc_exit();
out_fib:
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 */
MODULE_ALIAS_NETPROTO(PF_INET);
EXPORT_SYMBOL(inet_accept);
EXPORT_SYMBOL(inet_bind);
EXPORT_SYMBOL(inet_dgram_connect);
EXPORT_SYMBOL(inet_dgram_ops);
EXPORT_SYMBOL(inet_getname);
EXPORT_SYMBOL(inet_ioctl);
EXPORT_SYMBOL(inet_listen);
EXPORT_SYMBOL(inet_register_protosw);
EXPORT_SYMBOL(inet_release);
EXPORT_SYMBOL(inet_sendmsg);
EXPORT_SYMBOL(inet_shutdown);
EXPORT_SYMBOL(inet_sock_destruct);
EXPORT_SYMBOL(inet_stream_connect);
EXPORT_SYMBOL(inet_stream_ops);
EXPORT_SYMBOL(inet_unregister_protosw);
EXPORT_SYMBOL(net_statistics);
EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
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