net/ipv4/af_inet.c
/*
* 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.
*
* AF_INET protocol family socket handler.
*
* Version: @(#)af_inet.c (from sock.c) 1.0.17 06/02/93
*
* Authors: Ross Biro, <bir7@leland.Stanford.Edu>
* 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)
*
* 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.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/arp.h>
#include <net/rarp.h>
#include <net/route.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 <linux/ip_fw.h>
#ifdef CONFIG_IP_MASQUERADE
#include <net/ip_masq.h>
#endif
#ifdef CONFIG_IP_ALIAS
#include <net/ip_alias.h>
#endif
#ifdef CONFIG_BRIDGE
#include <net/br.h>
#endif
#ifdef CONFIG_KERNELD
#include <linux/kerneld.h>
#endif
#define min(a,b) ((a)<(b)?(a):(b))
extern struct proto packet_prot;
extern int raw_get_info(char *, char **, off_t, int, int);
extern int snmp_get_info(char *, char **, off_t, int, int);
extern int afinet_get_info(char *, char **, off_t, int, int);
extern int tcp_get_info(char *, char **, off_t, int, int);
extern int udp_get_info(char *, char **, off_t, int, int);
#ifdef CONFIG_DLCI
extern int dlci_ioctl(unsigned int, void*);
#endif
#ifdef CONFIG_DLCI_MODULE
int (*dlci_ioctl_hook)(unsigned int, void *) = NULL;
#endif
int (*rarp_ioctl_hook)(unsigned int,void*) = NULL;
/*
* See if a socket number is in use.
*/
static int sk_inuse(struct proto *prot, int num)
{
struct sock *sk;
for(sk = prot->sock_array[num & (SOCK_ARRAY_SIZE -1 )];
sk != NULL; sk=sk->next)
{
if (sk->num == num)
return(1);
}
return(0);
}
/*
* Pick a new socket number
*/
unsigned short get_new_socknum(struct proto *prot, unsigned short base)
{
static int start=0;
/*
* Used to cycle through the port numbers so the
* chances of a confused connection drop.
*/
int i, j;
int best = 0;
int size = 32767; /* a big num. */
struct sock *sk;
if (base == 0)
base = PROT_SOCK+1+(start & 1023);
if (base <= PROT_SOCK)
{
base += PROT_SOCK+(start & 1023);
}
/*
* Now look through the entire array and try to find an empty ptr.
*/
for(i=0; i < SOCK_ARRAY_SIZE; i++)
{
j = 0;
sk = prot->sock_array[(i+base+1) &(SOCK_ARRAY_SIZE -1)];
while(sk != NULL)
{
sk = sk->next;
j++;
}
if (j == 0)
{
start =(i+1+start )&1023;
return(i+base+1);
}
if (j < size)
{
best = i;
size = j;
}
}
/* Now make sure the one we want is not in use. */
while(sk_inuse(prot, base +best+1))
{
best += SOCK_ARRAY_SIZE;
}
return(best+base+1);
}
/*
* Add a socket into the socket tables by number.
*/
void put_sock(unsigned short num, struct sock *sk)
{
struct sock **skp, *tmp;
int mask;
unsigned long flags;
if(sk->type==SOCK_PACKET)
return;
sk->num = num;
sk->next = NULL;
num = num &(SOCK_ARRAY_SIZE -1);
/*
* We can't have an interrupt re-enter here.
*/
save_flags(flags);
cli();
sk->prot->inuse += 1;
if (sk->prot->highestinuse < sk->prot->inuse)
sk->prot->highestinuse = sk->prot->inuse;
if (sk->prot->sock_array[num] == NULL)
{
sk->prot->sock_array[num] = sk;
restore_flags(flags);
return;
}
restore_flags(flags);
for(mask = 0xff000000; mask != 0xffffffff; mask = (mask >> 8) | mask)
{
if ((mask & sk->rcv_saddr) &&
(mask & sk->rcv_saddr) != (mask & 0xffffffff))
{
mask = mask << 8;
break;
}
}
/*
* add the socket to the sock_array[]..
*/
skp = sk->prot->sock_array + num;
cli();
while ((tmp = *skp) != NULL) {
if (!(tmp->rcv_saddr & mask))
break;
skp = &tmp->next;
}
sk->next = tmp;
*skp = sk;
sti();
}
/*
* Remove a socket from the socket tables.
*/
static void remove_sock(struct sock *sk1)
{
struct sock **p;
unsigned long flags;
if (sk1->type==SOCK_PACKET)
return;
if (!sk1->prot)
{
NETDEBUG(printk("sock.c: remove_sock: sk1->prot == NULL\n"));
return;
}
/* We can't have this changing out from under us. */
save_flags(flags);
cli();
p=&(sk1->prot->sock_array[sk1->num & (SOCK_ARRAY_SIZE -1)]);
while(*p!=NULL)
{
if(*p==sk1)
{
sk1->prot->inuse--;
*p=sk1->next;
break;
}
p=&((*p)->next);
}
restore_flags(flags);
}
/*
* Destroy an AF_INET socket
*/
void destroy_sock(struct sock *sk)
{
struct sk_buff *skb;
lock_sock(sk); /* just to be safe. */
remove_sock(sk);
/*
* Now we can no longer get new packets or once the
* timers are killed, send them.
*/
delete_timer(sk);
del_timer(&sk->delack_timer);
del_timer(&sk->retransmit_timer);
/*
* Drain any partial frames
*/
while ((skb = tcp_dequeue_partial(sk)) != NULL)
{
IS_SKB(skb);
kfree_skb(skb, FREE_WRITE);
}
/*
* Cleanup up the write buffer.
*/
while((skb = skb_dequeue(&sk->write_queue)) != NULL) {
IS_SKB(skb);
kfree_skb(skb, FREE_WRITE);
}
/*
* Clean up the read buffer.
*/
while((skb=skb_dequeue(&sk->receive_queue))!=NULL)
{
/*
* This will take care of closing sockets that were
* listening and didn't accept everything.
*/
if (skb->sk != NULL && skb->sk != sk)
{
IS_SKB(skb);
skb->sk->prot->close(skb->sk, 0);
}
IS_SKB(skb);
kfree_skb(skb, FREE_READ);
}
/*
* Now we need to clean up the send head.
*/
cli();
for(skb = sk->send_head; skb != NULL; )
{
struct sk_buff *skb2;
/*
* We need to remove skb from the transmit queue,
* or maybe the arp queue.
*/
if (skb->next && skb->prev)
{
IS_SKB(skb);
skb_unlink(skb);
}
skb->dev = NULL;
skb2 = skb->link3;
kfree_skb(skb, FREE_WRITE);
skb = skb2;
}
sk->send_head = NULL;
sk->send_tail = NULL;
sk->send_next = NULL;
sti();
/*
* Now the backlog.
*/
while((skb=skb_dequeue(&sk->back_log))!=NULL)
{
/* this should [almost] never happen. */
skb->sk = NULL;
kfree_skb(skb, FREE_READ);
}
/*
* Now if it has a half accepted/ closed socket.
*/
if (sk->pair)
{
sk->pair->prot->close(sk->pair, 0);
sk->pair = NULL;
}
/*
* Now if everything is gone we can free the socket
* structure, otherwise we need to keep it around until
* everything is gone.
*/
if (sk->rmem_alloc == 0 && sk->wmem_alloc == 0)
{
if(sk->opt)
kfree(sk->opt);
ip_rt_put(sk->ip_route_cache);
/*
* This one is pure paranoia. I'll take it out
* later once I know the bug is buried.
*/
tcp_cache_zap();
sk_free(sk);
}
else
{
/* this should never happen. */
/* actually it can if an ack has just been sent. */
NETDEBUG(printk("Socket destroy delayed (r=%d w=%d)\n",
sk->rmem_alloc, sk->wmem_alloc));
sk->destroy = 1;
sk->ack_backlog = 0;
release_sock(sk);
reset_timer(sk, TIME_DESTROY, SOCK_DESTROY_TIME);
}
}
/*
* 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.
*/
static int inet_fcntl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
struct sock *sk;
sk = (struct sock *) sock->data;
switch(cmd)
{
case F_SETOWN:
/*
* This is a little restrictive, but it's the only
* way to make sure that you can't send a sigurg to
* another process.
*/
if (!suser() && current->pgrp != -arg &&
current->pid != arg) return(-EPERM);
sk->proc = arg;
return(0);
case F_GETOWN:
return(sk->proc);
default:
return(-EINVAL);
}
}
/*
* Set socket options on an inet socket.
*/
static int inet_setsockopt(struct socket *sock, int level, int optname,
char *optval, int optlen)
{
struct sock *sk = (struct sock *) sock->data;
if (level == SOL_SOCKET)
return sock_setsockopt(sk,level,optname,optval,optlen);
if (sk->prot->setsockopt==NULL)
return(-EOPNOTSUPP);
else
return sk->prot->setsockopt(sk,level,optname,optval,optlen);
}
/*
* Get a socket option on an AF_INET socket.
*/
static int inet_getsockopt(struct socket *sock, int level, int optname,
char *optval, int *optlen)
{
struct sock *sk = (struct sock *) sock->data;
if (level == SOL_SOCKET)
return sock_getsockopt(sk,level,optname,optval,optlen);
if(sk->prot->getsockopt==NULL)
return(-EOPNOTSUPP);
else
return sk->prot->getsockopt(sk,level,optname,optval,optlen);
}
/*
* Automatically bind an unbound socket.
*/
static int inet_autobind(struct sock *sk)
{
/* We may need to bind the socket. */
if (sk->num == 0)
{
sk->num = get_new_socknum(sk->prot, 0);
if (sk->num == 0)
return(-EAGAIN);
udp_cache_zap();
tcp_cache_zap();
put_sock(sk->num, sk);
sk->dummy_th.source = ntohs(sk->num);
}
return 0;
}
/*
* Move a socket into listening state.
*/
static int inet_listen(struct socket *sock, int backlog)
{
struct sock *sk = (struct sock *) sock->data;
if(inet_autobind(sk)!=0)
return -EAGAIN;
/* We might as well re use these. */
/*
* note that the backlog is "unsigned char", so truncate it
* somewhere. We might as well truncate it to what everybody
* else does..
* Now truncate to 128 not 5.
*/
if ((unsigned) backlog == 0) /* BSDism */
backlog = 1;
if ((unsigned) backlog > SOMAXCONN)
backlog = SOMAXCONN;
sk->max_ack_backlog = backlog;
if (sk->state != TCP_LISTEN)
{
sk->ack_backlog = 0;
sk->state = TCP_LISTEN;
}
return(0);
}
/*
* Default callbacks for user INET sockets. These just wake up
* the user owning the socket.
*/
static void def_callback1(struct sock *sk)
{
if(!sk->dead)
wake_up_interruptible(sk->sleep);
}
static void def_callback2(struct sock *sk,int len)
{
if(!sk->dead)
{
wake_up_interruptible(sk->sleep);
sock_wake_async(sk->socket, 1);
}
}
static void def_callback3(struct sock *sk)
{
if(!sk->dead && sk->wmem_alloc*2 <= sk->sndbuf)
{
wake_up_interruptible(sk->sleep);
sock_wake_async(sk->socket, 2);
}
}
/*
* Create an inet socket.
*
* FIXME: Gcc would generate much better code if we set the parameters
* up in in-memory structure order. Gcc68K even more so
*/
static int inet_create(struct socket *sock, int protocol)
{
struct sock *sk;
struct proto *prot;
int err;
sk = sk_alloc(GFP_KERNEL);
if (sk == NULL)
return(-ENOBUFS);
memset(sk,0,sizeof(*sk)); /* Efficient way to set most fields to zero */
/*
* Note for tcp that also wiped the dummy_th block for us.
*/
switch(sock->type)
{
case SOCK_STREAM:
case SOCK_SEQPACKET:
if (protocol && protocol != IPPROTO_TCP)
{
sk_free(sk);
return(-EPROTONOSUPPORT);
}
protocol = IPPROTO_TCP;
sk->no_check = TCP_NO_CHECK;
prot = &tcp_prot;
break;
case SOCK_DGRAM:
if (protocol && protocol != IPPROTO_UDP)
{
sk_free(sk);
return(-EPROTONOSUPPORT);
}
protocol = IPPROTO_UDP;
sk->no_check = UDP_NO_CHECK;
prot=&udp_prot;
break;
case SOCK_RAW:
if (!suser())
{
sk_free(sk);
return(-EPERM);
}
if (!protocol)
{
sk_free(sk);
return(-EPROTONOSUPPORT);
}
prot = &raw_prot;
sk->reuse = 1;
sk->num = protocol;
break;
case SOCK_PACKET:
if (!suser())
{
sk_free(sk);
return(-EPERM);
}
if (!protocol)
{
sk_free(sk);
return(-EPROTONOSUPPORT);
}
prot = &packet_prot;
sk->reuse = 1;
sk->num = protocol;
break;
default:
sk_free(sk);
return(-ESOCKTNOSUPPORT);
}
sk->socket = sock;
#ifdef CONFIG_TCP_NAGLE_OFF
sk->nonagle = 1;
#endif
sk->type = sock->type;
sk->protocol = protocol;
sk->allocation = GFP_KERNEL;
sk->sndbuf = SK_WMEM_MAX;
sk->rcvbuf = SK_RMEM_MAX;
sk->rto = TCP_TIMEOUT_INIT; /*TCP_WRITE_TIME*/
sk->cong_window = 1; /* start with only sending one packet at a time. */
sk->priority = 1;
sk->state = TCP_CLOSE;
/* this is how many unacked bytes we will accept for this socket. */
sk->max_unacked = 2048; /* needs to be at most 2 full packets. */
sk->delay_acks = 1;
sk->max_ack_backlog = SOMAXCONN;
skb_queue_head_init(&sk->write_queue);
skb_queue_head_init(&sk->receive_queue);
sk->mtu = 576;
sk->prot = prot;
sk->sleep = sock->wait;
init_timer(&sk->timer);
init_timer(&sk->delack_timer);
init_timer(&sk->retransmit_timer);
sk->timer.data = (unsigned long)sk;
sk->timer.function = &net_timer;
skb_queue_head_init(&sk->back_log);
sock->data =(void *) sk;
sk->dummy_th.doff = sizeof(sk->dummy_th)/4;
sk->ip_ttl=ip_statistics.IpDefaultTTL;
if(sk->type==SOCK_RAW && protocol==IPPROTO_RAW)
sk->ip_hdrincl=1;
else
sk->ip_hdrincl=0;
#ifdef CONFIG_IP_MULTICAST
sk->ip_mc_loop=1;
sk->ip_mc_ttl=1;
*sk->ip_mc_name=0;
sk->ip_mc_list=NULL;
#endif
/*
* Speed up by setting some standard state for the dummy_th
* if TCP uses it (maybe move to tcp_init later)
*/
sk->dummy_th.ack=1;
sk->dummy_th.doff=sizeof(struct tcphdr)>>2;
sk->state_change = def_callback1;
sk->data_ready = def_callback2;
sk->write_space = def_callback3;
sk->error_report = def_callback1;
if (sk->num)
{
/*
* It assumes that any protocol which allows
* the user to assign a number at socket
* creation time automatically
* shares.
*/
put_sock(sk->num, sk);
sk->dummy_th.source = ntohs(sk->num);
}
if (sk->prot->init)
{
err = sk->prot->init(sk);
if (err != 0)
{
destroy_sock(sk);
return(err);
}
}
return(0);
}
/*
* Duplicate a socket.
*/
static int inet_dup(struct socket *newsock, struct socket *oldsock)
{
return(inet_create(newsock,((struct sock *)(oldsock->data))->protocol));
}
/*
* 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.
*/
static int inet_release(struct socket *sock, struct socket *peer)
{
unsigned long timeout;
struct sock *sk = (struct sock *) sock->data;
if (sk == NULL)
return(0);
sk->state_change(sk);
/* Start closing the connection. This may take a while. */
#ifdef CONFIG_IP_MULTICAST
/* Applications forget to leave groups before exiting */
ip_mc_drop_socket(sk);
#endif
/*
* 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 (sk->linger) {
timeout = ~0UL;
if (!sk->lingertime)
timeout = jiffies + HZ*sk->lingertime;
}
if (current->flags & PF_EXITING)
timeout = 0;
sock->data = NULL;
sk->socket = NULL;
sk->prot->close(sk, timeout);
return(0);
}
static int inet_bind(struct socket *sock, struct sockaddr *uaddr,
int addr_len)
{
struct sockaddr_in *addr=(struct sockaddr_in *)uaddr;
struct sock *sk=(struct sock *)sock->data, *sk2;
unsigned short snum = 0 /* Stoopid compiler.. this IS ok */;
int chk_addr_ret;
/*
* If the socket has its own bind function then use it.
*/
if(sk->prot->bind)
return sk->prot->bind(sk,uaddr, addr_len);
/* check this error. */
if (sk->state != TCP_CLOSE)
return(-EIO);
if(addr_len<sizeof(struct sockaddr_in))
return -EINVAL;
if(sock->type != SOCK_RAW)
{
if (sk->num != 0)
return(-EINVAL);
snum = ntohs(addr->sin_port);
#ifdef CONFIG_IP_MASQUERADE
/*
* The kernel masquerader needs some ports
*/
if(snum>=PORT_MASQ_BEGIN && snum<=PORT_MASQ_END)
return -EADDRINUSE;
#endif
if (snum == 0)
snum = get_new_socknum(sk->prot, 0);
if (snum < PROT_SOCK && !suser())
return(-EACCES);
}
chk_addr_ret = ip_chk_addr(addr->sin_addr.s_addr);
#ifdef CONFIG_IP_TRANSPARENT_PROXY
/*
* Superuser may bind to any address to allow transparent proxying.
*/
if (addr->sin_addr.s_addr != 0 && chk_addr_ret != IS_MYADDR && chk_addr_ret != IS_MULTICAST && chk_addr_ret != IS_BROADCAST && !suser())
#else
if (addr->sin_addr.s_addr != 0 && chk_addr_ret != IS_MYADDR && chk_addr_ret != IS_MULTICAST && chk_addr_ret != IS_BROADCAST)
#endif
return(-EADDRNOTAVAIL); /* Source address MUST be ours! */
#ifndef CONFIG_IP_TRANSPARENT_PROXY
/*
* Am I just thick or is this test really always true after the one
* above? Just taking the test out appears to be the easiest way to
* make binds to remote addresses for transparent proxying work.
*/
if (chk_addr_ret || addr->sin_addr.s_addr == 0)
{
#endif
/*
* We keep a pair of addresses. rcv_saddr is the one
* used by get_sock_*(), 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.
*/
sk->rcv_saddr = addr->sin_addr.s_addr;
if(chk_addr_ret==IS_MULTICAST||chk_addr_ret==IS_BROADCAST)
sk->saddr = 0; /* Use device */
else
sk->saddr = addr->sin_addr.s_addr;
#ifndef CONFIG_IP_TRANSPARENT_PROXY
}
#endif
if(sock->type != SOCK_RAW)
{
/* Make sure we are allowed to bind here. */
cli();
for(sk2 = sk->prot->sock_array[snum & (SOCK_ARRAY_SIZE -1)];
sk2 != NULL; sk2 = sk2->next)
{
/*
* Hash collision or real match ?
*/
if (sk2->num != snum)
continue;
/*
* Either bind on the port is wildcard means
* they will overlap and thus be in error
*/
if (!sk2->rcv_saddr || !sk->rcv_saddr)
{
/*
* Allow only if both are setting reuse.
*/
if(sk2->reuse && sk->reuse && sk2->state!=TCP_LISTEN)
continue;
sti();
return(-EADDRINUSE);
}
/*
* Two binds match ?
*/
if (sk2->rcv_saddr != sk->rcv_saddr)
continue;
/*
* Reusable port ?
*/
if (!sk->reuse)
{
sti();
return(-EADDRINUSE);
}
/*
* Reuse ?
*/
if (!sk2->reuse || sk2->state==TCP_LISTEN)
{
sti();
return(-EADDRINUSE);
}
}
sti();
remove_sock(sk);
if(sock->type==SOCK_DGRAM)
udp_cache_zap();
if(sock->type==SOCK_STREAM)
tcp_cache_zap();
put_sock(snum, sk);
sk->dummy_th.source = ntohs(sk->num);
sk->daddr = 0;
sk->dummy_th.dest = 0;
}
ip_rt_put(sk->ip_route_cache);
sk->ip_route_cache=NULL;
return(0);
}
/*
* Connect to a remote host. There is regrettably still a little
* TCP 'magic' in here.
*/
static int inet_connect(struct socket *sock, struct sockaddr * uaddr,
int addr_len, int flags)
{
struct sock *sk=(struct sock *)sock->data;
int err;
sock->conn = NULL;
if (sock->state == SS_CONNECTING && tcp_connected(sk->state))
{
sock->state = SS_CONNECTED;
/* Connection completing after a connect/EINPROGRESS/select/connect */
return 0; /* Rock and roll */
}
if (sock->state == SS_CONNECTING && sk->protocol == IPPROTO_TCP && (flags & O_NONBLOCK))
{
if(sk->err!=0)
return sock_error(sk);
return -EALREADY; /* Connecting is currently in progress */
}
if (sock->state != SS_CONNECTING)
{
/* We may need to bind the socket. */
if(inet_autobind(sk)!=0)
return(-EAGAIN);
if (sk->prot->connect == NULL)
return(-EOPNOTSUPP);
err = sk->prot->connect(sk, (struct sockaddr_in *)uaddr, addr_len);
if (err < 0)
return(err);
sock->state = SS_CONNECTING;
}
if (sk->state > TCP_FIN_WAIT2 && sock->state==SS_CONNECTING)
{
sock->state=SS_UNCONNECTED;
return sock_error(sk);
}
if (sk->state != TCP_ESTABLISHED &&(flags & O_NONBLOCK))
return(-EINPROGRESS);
cli(); /* avoid the race condition */
while(sk->state == TCP_SYN_SENT || sk->state == TCP_SYN_RECV)
{
interruptible_sleep_on(sk->sleep);
if (current->signal & ~current->blocked)
{
sti();
return(-ERESTARTSYS);
}
/* This fixes a nasty in the tcp/ip code. There is a hideous hassle with
icmp error packets wanting to close a tcp or udp socket. */
if(sk->err && sk->protocol == IPPROTO_TCP)
{
sock->state = SS_UNCONNECTED;
sti();
return sock_error(sk); /* set by tcp_err() */
}
}
sti();
sock->state = SS_CONNECTED;
if (sk->state != TCP_ESTABLISHED && sk->err)
{
sock->state = SS_UNCONNECTED;
return sock_error(sk);
}
return(0);
}
static int inet_socketpair(struct socket *sock1, struct socket *sock2)
{
return(-EOPNOTSUPP);
}
/*
* Accept a pending connection. The TCP layer now gives BSD semantics.
*/
static int inet_accept(struct socket *sock, struct socket *newsock, int flags)
{
struct sock *sk1, *sk2;
int err;
sk1 = (struct sock *) sock->data;
/*
* We've been passed an extra socket.
* We need to free it up because the tcp module creates
* its own when it accepts one.
*/
if (newsock->data)
{
struct sock *sk=(struct sock *)newsock->data;
newsock->data=NULL;
destroy_sock(sk);
}
if (sk1->prot->accept == NULL)
return(-EOPNOTSUPP);
/*
* Restore the state if we have been interrupted, and then returned.
*/
if (sk1->pair != NULL )
{
sk2 = sk1->pair;
sk1->pair = NULL;
}
else
{
sk2 = sk1->prot->accept(sk1,flags);
if (sk2 == NULL)
{
return sock_error(sk1);
}
}
newsock->data = (void *)sk2;
sk2->sleep = newsock->wait;
sk2->socket = newsock;
newsock->conn = NULL;
if (flags & O_NONBLOCK)
return(0);
cli(); /* avoid the race. */
while(sk2->state == TCP_SYN_RECV)
{
interruptible_sleep_on(sk2->sleep);
if (current->signal & ~current->blocked)
{
sti();
sk1->pair = sk2;
sk2->sleep = NULL;
sk2->socket=NULL;
newsock->data = NULL;
return(-ERESTARTSYS);
}
}
sti();
if (sk2->state != TCP_ESTABLISHED && sk2->err > 0)
{
err = sock_error(sk2);
destroy_sock(sk2);
newsock->data = NULL;
return err;
}
newsock->state = SS_CONNECTED;
return(0);
}
/*
* This does both peername and sockname.
*/
static int inet_getname(struct socket *sock, struct sockaddr *uaddr,
int *uaddr_len, int peer)
{
struct sockaddr_in *sin=(struct sockaddr_in *)uaddr;
struct sock *sk;
sin->sin_family = AF_INET;
sk = (struct sock *) sock->data;
if (peer)
{
if (!tcp_connected(sk->state))
return(-ENOTCONN);
sin->sin_port = sk->dummy_th.dest;
sin->sin_addr.s_addr = sk->daddr;
}
else
{
__u32 addr = sk->rcv_saddr;
if (!addr) {
addr = sk->saddr;
if (!addr)
addr = ip_my_addr();
}
sin->sin_port = sk->dummy_th.source;
sin->sin_addr.s_addr = addr;
}
*uaddr_len = sizeof(*sin);
return(0);
}
static int inet_recvmsg(struct socket *sock, struct msghdr *ubuf, int size, int noblock,
int flags, int *addr_len )
{
struct sock *sk = (struct sock *) sock->data;
if (sk->prot->recvmsg == NULL)
return(-EOPNOTSUPP);
if(sk->err)
return sock_error(sk);
/* We may need to bind the socket. */
if(inet_autobind(sk)!=0)
return(-EAGAIN);
return(sk->prot->recvmsg(sk, ubuf, size, noblock, flags,addr_len));
}
static int inet_sendmsg(struct socket *sock, struct msghdr *msg, int size, int noblock,
int flags)
{
struct sock *sk = (struct sock *) sock->data;
if (sk->shutdown & SEND_SHUTDOWN)
{
send_sig(SIGPIPE, current, 1);
return(-EPIPE);
}
if (sk->prot->sendmsg == NULL)
return(-EOPNOTSUPP);
if(sk->err)
return sock_error(sk);
/* We may need to bind the socket. */
if(inet_autobind(sk)!=0)
return -EAGAIN;
return(sk->prot->sendmsg(sk, msg, size, noblock, flags));
}
static int inet_shutdown(struct socket *sock, int how)
{
struct sock *sk=(struct sock*)sock->data;
/*
* 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==0) /* MAXINT->0 */
return(-EINVAL);
if (sock->state == SS_CONNECTING && sk->state == TCP_ESTABLISHED)
sock->state = SS_CONNECTED;
if (!sk || !tcp_connected(sk->state))
return(-ENOTCONN);
sk->shutdown |= how;
if (sk->prot->shutdown)
sk->prot->shutdown(sk, how);
return(0);
}
static int inet_select(struct socket *sock, int sel_type, select_table *wait )
{
struct sock *sk=(struct sock *) sock->data;
if (sk->prot->select == NULL)
{
return(0);
}
return(sk->prot->select(sk, sel_type, wait));
}
/*
* 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.
*/
static int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
struct sock *sk=(struct sock *)sock->data;
int err;
int pid;
switch(cmd)
{
case FIOSETOWN:
case SIOCSPGRP:
err=verify_area(VERIFY_READ,(int *)arg,sizeof(long));
if(err)
return err;
pid = get_user((int *) arg);
/* see inet_fcntl */
if (current->pid != pid && current->pgrp != -pid && !suser())
return -EPERM;
sk->proc = pid;
return(0);
case FIOGETOWN:
case SIOCGPGRP:
err=verify_area(VERIFY_WRITE,(void *) arg, sizeof(long));
if(err)
return err;
put_fs_long(sk->proc,(int *)arg);
return(0);
case SIOCGSTAMP:
if(sk->stamp.tv_sec==0)
return -ENOENT;
err=verify_area(VERIFY_WRITE,(void *)arg,sizeof(struct timeval));
if(err)
return err;
memcpy_tofs((void *)arg,&sk->stamp,sizeof(struct timeval));
return 0;
case SIOCADDRT:
case SIOCDELRT:
return(ip_rt_ioctl(cmd,(void *) arg));
case SIOCDARP:
case SIOCGARP:
case SIOCSARP:
case OLD_SIOCDARP:
case OLD_SIOCGARP:
case OLD_SIOCSARP:
return(arp_ioctl(cmd,(void *) arg));
case SIOCDRARP:
case SIOCGRARP:
case SIOCSRARP:
#ifdef CONFIG_KERNELD
if (rarp_ioctl_hook == NULL)
request_module("rarp");
#endif
if (rarp_ioctl_hook != NULL)
return(rarp_ioctl_hook(cmd,(void *) arg));
case SIOCGIFCONF:
case SIOCGIFFLAGS:
case SIOCSIFFLAGS:
case SIOCGIFADDR:
case SIOCSIFADDR:
case SIOCADDMULTI:
case SIOCDELMULTI:
case SIOCGIFDSTADDR:
case SIOCSIFDSTADDR:
case SIOCGIFBRDADDR:
case SIOCSIFBRDADDR:
case SIOCGIFNETMASK:
case SIOCSIFNETMASK:
case SIOCGIFMETRIC:
case SIOCSIFMETRIC:
case SIOCGIFMEM:
case SIOCSIFMEM:
case SIOCGIFMTU:
case SIOCSIFMTU:
case SIOCSIFLINK:
case SIOCGIFHWADDR:
case SIOCSIFHWADDR:
case SIOCSIFMAP:
case SIOCGIFMAP:
case SIOCSIFSLAVE:
case SIOCGIFSLAVE:
return(dev_ioctl(cmd,(void *) arg));
case SIOCGIFBR:
case SIOCSIFBR:
#ifdef CONFIG_BRIDGE
return(br_ioctl(cmd,(void *) arg));
#else
return -ENOPKG;
#endif
case SIOCADDDLCI:
case SIOCDELDLCI:
#ifdef CONFIG_DLCI
return(dlci_ioctl(cmd, (void *) arg));
#endif
#ifdef CONFIG_DLCI_MODULE
#ifdef CONFIG_KERNELD
if (dlci_ioctl_hook == NULL)
request_module("dlci");
#endif
if (dlci_ioctl_hook)
return((*dlci_ioctl_hook)(cmd, (void *) arg));
#endif
return -ENOPKG;
default:
if ((cmd >= SIOCDEVPRIVATE) &&
(cmd <= (SIOCDEVPRIVATE + 15)))
return(dev_ioctl(cmd,(void *) arg));
if (sk->prot->ioctl==NULL)
return(-EINVAL);
return(sk->prot->ioctl(sk, cmd, arg));
}
/*NOTREACHED*/
return(0);
}
#ifdef CONFIG_IP_TRANSPARENT_PROXY
/*
* Some routines for the for loop in get_sock which sometimes needs to walk
* two linked lists in sequence. Could use macros as well.
* Does anyone know a nicer way to code this?
*/
static __inline__ struct sock *secondlist(unsigned short hpnum, struct sock *s,
int *pfirstpass, struct proto *prot)
{
if (hpnum && s == NULL && (*pfirstpass)-- )
return prot->sock_array[hpnum & (SOCK_ARRAY_SIZE - 1)];
else
return s;
}
static __inline__ struct sock *get_sock_loop_init(unsigned short hnum,
unsigned short hpnum, struct sock *s,
int *pfirstpass, struct proto *prot)
{
s = prot->sock_array[hnum & (SOCK_ARRAY_SIZE - 1)];
return secondlist(hpnum, s, pfirstpass, prot);
}
static __inline__ struct sock *get_sock_loop_next(unsigned short hnum,
unsigned short hpnum, struct sock *s,
int *pfirstpass, struct proto *prot)
{
s = s->next;
return secondlist(hpnum, s, pfirstpass, prot);
}
#endif
/*
* This routine must find a socket given a TCP or UDP header.
* Everything is assumed to be in net order.
*
* We give priority to more closely bound ports: if some socket
* is bound to a particular foreign address, it will get the packet
* rather than somebody listening to any address..
*/
struct sock *get_sock(struct proto *prot, unsigned short num,
unsigned long raddr,
unsigned short rnum, unsigned long laddr,
unsigned long paddr, unsigned short pnum)
{
struct sock *s = 0;
struct sock *result = NULL;
int badness = -1;
unsigned short hnum;
#ifdef CONFIG_IP_TRANSPARENT_PROXY
unsigned short hpnum;
int firstpass = 1;
#endif
hnum = ntohs(num);
#ifdef CONFIG_IP_TRANSPARENT_PROXY
hpnum = ntohs(pnum);
#endif
/*
* SOCK_ARRAY_SIZE must be a power of two. This will work better
* than a prime unless 3 or more sockets end up using the same
* array entry. This should not be a problem because most
* well known sockets don't overlap that much, and for
* the other ones, we can just be careful about picking our
* socket number when we choose an arbitrary one.
*/
#ifdef CONFIG_IP_TRANSPARENT_PROXY
for(s = get_sock_loop_init(hnum, hpnum, s, &firstpass, prot);
s != NULL;
s = get_sock_loop_next(hnum, hpnum, s, &firstpass, prot))
#else
for(s = prot->sock_array[hnum & (SOCK_ARRAY_SIZE - 1)];
s != NULL; s = s->next)
#endif
{
int score = 0;
#ifdef CONFIG_IP_TRANSPARENT_PROXY
/* accept the addressed port or the redirect (proxy) port */
if (s->num != hnum && (hpnum == 0 || s->num != hpnum))
#else
if (s->num != hnum)
#endif
continue;
if(s->dead && (s->state == TCP_CLOSE))
continue;
/* local address matches? */
if (s->rcv_saddr) {
#ifdef CONFIG_IP_TRANSPARENT_PROXY
/*
* If this is redirected traffic, it must either
* match on the redirected port/ip-address or on
* the actual destination, not on a mixture.
* There must be a simpler way to express this...
*/
if (hpnum
? ((s->num != hpnum || s->rcv_saddr != paddr)
&& (s->num != hnum || s->rcv_saddr != laddr))
: (s->rcv_saddr != laddr))
#else
if (s->rcv_saddr != laddr)
#endif
continue;
score++;
}
/* remote address matches? */
if (s->daddr) {
if (s->daddr != raddr)
continue;
score++;
}
/* remote port matches? */
if (s->dummy_th.dest) {
if (s->dummy_th.dest != rnum)
continue;
score++;
}
/* perfect match? */
#ifdef CONFIG_IP_TRANSPARENT_PROXY
if (score == 3 && s->num == hnum)
#else
if (score == 3)
#endif
return s;
/* no, check if this is the best so far.. */
if (score <= badness)
continue;
#ifdef CONFIG_IP_TRANSPARENT_PROXY
/* don't accept near matches on the actual destination
* port with IN_ADDR_ANY for redirected traffic, but do
* allow explicit remote address listens. (disputable)
*/
if (hpnum && s->num != hpnum && !s->rcv_saddr)
continue;
#endif
result = s;
badness = score;
}
return result;
}
/*
* Deliver a datagram to raw sockets.
*/
struct sock *get_sock_raw(struct sock *sk,
unsigned short num,
unsigned long raddr,
unsigned long laddr)
{
struct sock *s;
s=sk;
for(; s != NULL; s = s->next)
{
if (s->num != num)
continue;
if(s->dead && (s->state == TCP_CLOSE))
continue;
if(s->daddr && s->daddr!=raddr)
continue;
if(s->rcv_saddr && s->rcv_saddr != laddr)
continue;
return(s);
}
return(NULL);
}
#ifdef CONFIG_IP_MULTICAST
/*
* Deliver a datagram to broadcast/multicast sockets.
*/
struct sock *get_sock_mcast(struct sock *sk,
unsigned short num,
unsigned long raddr,
unsigned short rnum, unsigned long laddr)
{
struct sock *s;
unsigned short hnum;
hnum = ntohs(num);
/*
* SOCK_ARRAY_SIZE must be a power of two. This will work better
* than a prime unless 3 or more sockets end up using the same
* array entry. This should not be a problem because most
* well known sockets don't overlap that much, and for
* the other ones, we can just be careful about picking our
* socket number when we choose an arbitrary one.
*/
s=sk;
for(; s != NULL; s = s->next)
{
if (s->num != hnum)
continue;
if(s->dead && (s->state == TCP_CLOSE))
continue;
if(s->daddr && s->daddr!=raddr)
continue;
if (s->dummy_th.dest != rnum && s->dummy_th.dest != 0)
continue;
if(s->rcv_saddr && s->rcv_saddr != laddr)
continue;
return(s);
}
return(NULL);
}
#endif
static struct proto_ops inet_proto_ops = {
AF_INET,
inet_create,
inet_dup,
inet_release,
inet_bind,
inet_connect,
inet_socketpair,
inet_accept,
inet_getname,
inet_select,
inet_ioctl,
inet_listen,
inet_shutdown,
inet_setsockopt,
inet_getsockopt,
inet_fcntl,
inet_sendmsg,
inet_recvmsg
};
extern unsigned long seq_offset;
/*
* Called by socket.c on kernel startup.
*/
void inet_proto_init(struct net_proto *pro)
{
struct inet_protocol *p;
int i;
printk("Swansea University Computer Society TCP/IP for NET3.034\n");
/*
* Tell SOCKET that we are alive...
*/
(void) sock_register(inet_proto_ops.family, &inet_proto_ops);
seq_offset = CURRENT_TIME*250;
/*
* Add all the protocols.
*/
for(i = 0; i < SOCK_ARRAY_SIZE; i++)
{
tcp_prot.sock_array[i] = NULL;
udp_prot.sock_array[i] = NULL;
raw_prot.sock_array[i] = NULL;
}
tcp_prot.inuse = 0;
tcp_prot.highestinuse = 0;
udp_prot.inuse = 0;
udp_prot.highestinuse = 0;
raw_prot.inuse = 0;
raw_prot.highestinuse = 0;
printk("IP Protocols: ");
for(p = inet_protocol_base; p != NULL;)
{
struct inet_protocol *tmp = (struct inet_protocol *) p->next;
inet_add_protocol(p);
printk("%s%s",p->name,tmp?", ":"\n");
p = tmp;
}
/*
* Set the ARP module up
*/
arp_init();
/*
* Set the IP module up
*/
ip_init();
/*
* Set the ICMP layer up
*/
icmp_init(&inet_proto_ops);
/*
* Set the firewalling up
*/
#if defined(CONFIG_IP_ACCT)||defined(CONFIG_IP_FIREWALL)|| \
defined(CONFIG_IP_MASQUERADE)
ip_fw_init();
#endif
/*
* Initialise the multicast router
*/
#if defined(CONFIG_IP_MROUTE)
ip_mr_init();
#endif
/*
* Initialise AF_INET alias type (register net_alias_type)
*/
#if defined(CONFIG_IP_ALIAS)
ip_alias_init();
#endif
#ifdef CONFIG_INET_RARP
rarp_ioctl_hook = rarp_ioctl;
#endif
/*
* Create all the /proc entries.
*/
#ifdef CONFIG_PROC_FS
#ifdef CONFIG_INET_RARP
proc_net_register(&(struct proc_dir_entry) {
PROC_NET_RARP, 4, "rarp",
S_IFREG | S_IRUGO, 1, 0, 0,
0, &proc_net_inode_operations,
rarp_get_info
});
#endif /* RARP */
proc_net_register(&(struct proc_dir_entry) {
PROC_NET_RAW, 3, "raw",
S_IFREG | S_IRUGO, 1, 0, 0,
0, &proc_net_inode_operations,
raw_get_info
});
proc_net_register(&(struct proc_dir_entry) {
PROC_NET_SNMP, 4, "snmp",
S_IFREG | S_IRUGO, 1, 0, 0,
0, &proc_net_inode_operations,
snmp_get_info
});
proc_net_register(&(struct proc_dir_entry) {
PROC_NET_SOCKSTAT, 8, "sockstat",
S_IFREG | S_IRUGO, 1, 0, 0,
0, &proc_net_inode_operations,
afinet_get_info
});
proc_net_register(&(struct proc_dir_entry) {
PROC_NET_TCP, 3, "tcp",
S_IFREG | S_IRUGO, 1, 0, 0,
0, &proc_net_inode_operations,
tcp_get_info
});
proc_net_register(&(struct proc_dir_entry) {
PROC_NET_UDP, 3, "udp",
S_IFREG | S_IRUGO, 1, 0, 0,
0, &proc_net_inode_operations,
udp_get_info
});
proc_net_register(&(struct proc_dir_entry) {
PROC_NET_ROUTE, 5, "route",
S_IFREG | S_IRUGO, 1, 0, 0,
0, &proc_net_inode_operations,
rt_get_info
});
proc_net_register(&(struct proc_dir_entry) {
PROC_NET_RTCACHE, 8, "rt_cache",
S_IFREG | S_IRUGO, 1, 0, 0,
0, &proc_net_inode_operations,
rt_cache_get_info
});
#endif /* CONFIG_PROC_FS */
}
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