af_ipx.c

讲述linux的初始化过程

	sg = (struct sockaddr_ipx *)&rt.rt_gateway;
	st = (struct sockaddr_ipx *)&rt.rt_dst;

	if(!(rt.rt_flags & RTF_GATEWAY))
		return (-EINVAL);	/* Direct routes are fixed */
	if(sg->sipx_family != AF_IPX)
		return (-EINVAL);
	if(st->sipx_family != AF_IPX)
		return (-EINVAL);

	switch(cmd)
	{
		case SIOCDELRT:
			return (ipxrtr_delete(st->sipx_network));

		case SIOCADDRT:
		{
			struct ipx_route_definition f;
			f.ipx_network=st->sipx_network;
			f.ipx_router_network=sg->sipx_network;
			memcpy(f.ipx_router_node, sg->sipx_node, IPX_NODE_LEN);
			return (ipxrtr_create(&f));
		}

		default:
			return (-EINVAL);
	}
}

static const char *ipx_frame_name(unsigned short frame)
{
	switch(ntohs(frame)) 
	{
		case ETH_P_IPX:
			return ("EtherII");

		case ETH_P_802_2:
			return ("802.2");

		case ETH_P_SNAP:
			return ("SNAP");

		case ETH_P_802_3:
			return ("802.3");

		case ETH_P_TR_802_2:
			return ("802.2TR");

		default:
			return ("None");
	}
}

static const char *ipx_device_name(ipx_interface *intrfc)
{
	return (intrfc->if_internal ? "Internal" :
		(intrfc->if_dev ? intrfc->if_dev->name : "Unknown"));
}

/* Called from proc fs */
static int ipx_interface_get_info(char *buffer, char **start, off_t offset,
				  int length)
{
	ipx_interface *i;
	off_t begin = 0, pos = 0;
	int len = 0;

	/* Theory.. Keep printing in the same place until we pass offset */

	len += sprintf(buffer,"%-11s%-15s%-9s%-11s%s", "Network",
		"Node_Address", "Primary", "Device", "Frame_Type");
#ifdef IPX_REFCNT_DEBUG
	len += sprintf(buffer + len, "  refcnt");
#endif
	strcat(buffer+len++, "\n");
	spin_lock_bh(&ipx_interfaces_lock);
	for(i = ipx_interfaces; i != NULL; i = i->if_next)
	{
		len += sprintf(buffer+len, "%08lX   ", (long unsigned int)ntohl(i->if_netnum));
		len += sprintf(buffer+len,"%02X%02X%02X%02X%02X%02X   ",
				i->if_node[0], i->if_node[1], i->if_node[2],
				i->if_node[3], i->if_node[4], i->if_node[5]);
		len += sprintf(buffer+len, "%-9s", (i == ipx_primary_net) ?
			"Yes" : "No");
		len += sprintf(buffer+len, "%-11s", ipx_device_name(i));
		len += sprintf(buffer+len, "%-9s",
			ipx_frame_name(i->if_dlink_type));
#ifdef IPX_REFCNT_DEBUG
		len += sprintf(buffer+len,"%6d",atomic_read(&i->refcnt));
#endif
		strcat(buffer+len++, "\n");
		/* Are we still dumping unwanted data then discard the record */
		pos = begin + len;

		if(pos < offset)
		{
			len   = 0;	/* Keep dumping into the buffer start */
			begin = pos;
		}
		if(pos > offset + length)	/* We have dumped enough */
			break;
	}
	spin_unlock_bh(&ipx_interfaces_lock);

	/* The data in question runs from begin to begin+len */
	*start = buffer + (offset - begin);	/* Start of wanted data */
	len -= (offset - begin); /* Remove unwanted header data from length */
	if(len > length)
		len = length;	/* Remove unwanted tail data from length */

	return (len);
}

static int ipx_get_info(char *buffer, char **start, off_t offset, int length)
{
	struct sock *s;
	ipx_interface *i;
	off_t begin = 0, pos = 0;
	int len = 0;

	/* Theory.. Keep printing in the same place until we pass offset */

#ifdef CONFIG_IPX_INTERN
	len += sprintf(buffer,"%-28s%-28s%-10s%-10s%-7s%s\n", "Local_Address",
#else
	len += sprintf(buffer,"%-15s%-28s%-10s%-10s%-7s%s\n", "Local_Address",
#endif	/* CONFIG_IPX_INTERN */
			"Remote_Address", "Tx_Queue", "Rx_Queue",
			"State", "Uid");

	spin_lock_bh(&ipx_interfaces_lock);
	for(i = ipx_interfaces; i != NULL; i = i->if_next)
	{
		ipxitf_hold(i);
		spin_lock_bh(&i->if_sklist_lock);
		for(s = i->if_sklist; s != NULL; s = s->next)
		{
#ifdef CONFIG_IPX_INTERN
			len += sprintf(buffer+len,
				       "%08lX:%02X%02X%02X%02X%02X%02X:%04X  ",
                                       (unsigned long) htonl(s->protinfo.af_ipx.intrfc->if_netnum),
				       s->protinfo.af_ipx.node[0],
				       s->protinfo.af_ipx.node[1],
				       s->protinfo.af_ipx.node[2],
				       s->protinfo.af_ipx.node[3],
				       s->protinfo.af_ipx.node[4],
				       s->protinfo.af_ipx.node[5],
				       htons(s->protinfo.af_ipx.port));
#else
			len += sprintf(buffer+len,"%08lX:%04X  ",
				       (unsigned long)htonl(i->if_netnum),
				       htons(s->protinfo.af_ipx.port));
#endif	/* CONFIG_IPX_INTERN */

			if(s->state != TCP_ESTABLISHED)
				len += sprintf(buffer+len, "%-28s", "Not_Connected");
			else
			{
				len += sprintf(buffer+len,
					"%08lX:%02X%02X%02X%02X%02X%02X:%04X  ",
					(unsigned long) htonl(s->protinfo.af_ipx.dest_addr.net),
					s->protinfo.af_ipx.dest_addr.node[0],
					s->protinfo.af_ipx.dest_addr.node[1],
					s->protinfo.af_ipx.dest_addr.node[2],
					s->protinfo.af_ipx.dest_addr.node[3],
					s->protinfo.af_ipx.dest_addr.node[4],
					s->protinfo.af_ipx.dest_addr.node[5],
					htons(s->protinfo.af_ipx.dest_addr.sock));
			}

			len += sprintf(buffer+len,"%08X  %08X  ",
				atomic_read(&s->wmem_alloc),
				atomic_read(&s->rmem_alloc));
			len += sprintf(buffer+len,"%02X     %03d\n",
				s->state, SOCK_INODE(s->socket)->i_uid);

			pos = begin + len;
			if(pos < offset)
			{
				len   = 0;
				begin = pos;
			}

			if(pos > offset + length)  /* We have dumped enough */
				break;
		}
		spin_unlock_bh(&i->if_sklist_lock);
		ipxitf_put(i);
	}
	spin_unlock_bh(&ipx_interfaces_lock);

	/* The data in question runs from begin to begin+len */
	*start = buffer + (offset-begin);
	len -= (offset - begin);
	if(len > length)
		len = length;

	return (len);
}

static int ipx_rt_get_info(char *buffer, char **start, off_t offset, int length)
{
	ipx_route *rt;
	off_t begin = 0, pos = 0;
	int len = 0;

	len += sprintf(buffer,"%-11s%-13s%s\n",
			"Network", "Router_Net", "Router_Node");
	read_lock_bh(&ipx_routes_lock);
	for(rt = ipx_routes; rt != NULL; rt = rt->ir_next)
	{
		len += sprintf(buffer+len,"%08lX   ", (long unsigned int) ntohl(rt->ir_net));
		if(rt->ir_routed)
		{
			len += sprintf(buffer+len,"%08lX     %02X%02X%02X%02X%02X%02X\n",
				(long unsigned int) ntohl(rt->ir_intrfc->if_netnum),
				rt->ir_router_node[0], rt->ir_router_node[1],
				rt->ir_router_node[2], rt->ir_router_node[3],
				rt->ir_router_node[4], rt->ir_router_node[5]);
		}
		else
		{
			len += sprintf(buffer+len, "%-13s%s\n",
					"Directly", "Connected");
		}

		pos = begin + len;
		if(pos < offset)
		{
			len   = 0;
			begin = pos;
		}

		if(pos > offset + length)
			break;
	}
	read_unlock_bh(&ipx_routes_lock);

	*start = buffer + (offset - begin);
	len -= (offset - begin);
	if(len > length)
		len = length;

	return (len);
}

/**************************************************************************\
*                                                                          *
* Handling for system calls applied via the various interfaces to an       *
* IPX socket object.                                                       *
*                                                                          *
\**************************************************************************/

static int ipx_setsockopt(struct socket *sock, int level, int optname, char *optval, int optlen)
{
	struct sock *sk;
	int err, opt;

	sk = sock->sk;

	if(optlen != sizeof(int))
		return (-EINVAL);

	err = get_user(opt, (unsigned int *)optval);
	if(err)
		return (err);

	switch(level)
	{
		case SOL_IPX:
			switch(optname)
			{
				case IPX_TYPE:
					sk->protinfo.af_ipx.type = opt;
					return (0);

				default:
					return (-ENOPROTOOPT);
			}
			break;

		default:
			return (-ENOPROTOOPT);
	}
}

static int ipx_getsockopt(struct socket *sock, int level, int optname,
	char *optval, int *optlen)
{
	struct sock *sk;
	int val=0;
	int len;

	sk = sock->sk;

	switch(level)
	{
		case SOL_IPX:
			switch(optname)
			{
				case IPX_TYPE:
					val = sk->protinfo.af_ipx.type;
					break;

				default:
					return (-ENOPROTOOPT);
			}
			break;

		default:
			return (-ENOPROTOOPT);
	}

	if(get_user(len, optlen))
		return (-EFAULT);

	len = min(len, sizeof(int));
	if(put_user(len, optlen))
		return (-EFAULT);

	if(copy_to_user(optval, &val, len))
		return (-EFAULT);

	return (0);
}

static int ipx_create(struct socket *sock, int protocol)
{
	struct sock *sk;

	switch(sock->type)
	{
		case SOCK_DGRAM:
			sk = sk_alloc(PF_IPX, GFP_KERNEL, 1);
			if(sk == NULL)
                		return (-ENOMEM);
                        sock->ops = &ipx_dgram_ops;
                        break;

		case SOCK_SEQPACKET:
			/*
			 * From this point on SPX sockets are handled
			 * by af_spx.c and the methods replaced.
			 */
			if(spx_family_ops)
				return (spx_family_ops->create(sock,protocol));
			/* Fall through if SPX is not loaded */
		case SOCK_STREAM:       /* Allow higher levels to piggyback */
		default:
			return (-ESOCKTNOSUPPORT);
	}
#ifdef IPX_REFCNT_DEBUG
        atomic_inc(&ipx_sock_nr);
        printk(KERN_DEBUG "IPX socket %p created, now we have %d alive\n", sk,
			atomic_read(&ipx_sock_nr));
#endif
	sock_init_data(sock, sk);
	sk->destruct	= NULL;
	sk->no_check 	= 1;		/* Checksum off by default */

	MOD_INC_USE_COUNT;

	return (0);
}

static int ipx_release(struct socket *sock)
{
	struct sock *sk = sock->sk;

	if(sk == NULL)
		return (0);

	if(!sk->dead)
		sk->state_change(sk);

	sk->dead = 1;
	sock->sk = NULL;
	ipx_destroy_socket(sk);

	if(sock->type == SOCK_DGRAM)
		MOD_DEC_USE_COUNT;

	return (0);
}

/* caller must hold a referente to intrfc */

static unsigned short ipx_first_free_socketnum(ipx_interface *intrfc)
{
	unsigned short socketNum = intrfc->if_sknum;

	spin_lock_bh(&intrfc->if_sklist_lock);

	if(socketNum < IPX_MIN_EPHEMERAL_SOCKET)
		socketNum = IPX_MIN_EPHEMERAL_SOCKET;

	while(__ipxitf_find_socket(intrfc, ntohs(socketNum)) != NULL)
	{
		if(socketNum > IPX_MAX_EPHEMERAL_SOCKET)
			socketNum = IPX_MIN_EPHEMERAL_SOCKET;
		else
			socketNum++;
	}

	spin_unlock_bh(&intrfc->if_sklist_lock);
	intrfc->if_sknum = socketNum;

	return (ntohs(socketNum));
}

static int ipx_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
	struct sock *sk;
	ipx_interface *intrfc;
	struct sockaddr_ipx *addr = (struct sockaddr_ipx *)uaddr;
	int ret;

	sk = sock->sk;

	if(sk->zapped == 0)
		return (-EINVAL);

	if(addr_len != sizeof(struct sockaddr_ipx))
		return (-EINVAL);

	intrfc = ipxitf_find_using_net(addr->sipx_network);
	if(intrfc == NULL)
		return (-EADDRNOTAVAIL);

	if(addr->sipx_port == 0)
	{
		addr->sipx_port = ipx_first_free_socketnum(intrfc);
		ret = -EINVAL;
		if(addr->sipx_port == 0)
			goto out;
	}

	/* protect IPX system stuff like routing/sap */
	ret = -EACCES;
	if(ntohs(addr->sipx_port) < IPX_MIN_EPHEMERAL_SOCKET && !capable(CAP_NET_ADMIN))
		goto out;

	sk->protinfo.af_ipx.port = addr->sipx_port;

#ifdef CONFIG_IPX_INTERN
	if(intrfc == ipx_internal_net)
	{
		/* The source address is to be set explicitly if the
		 * socket is to be bound on the internal network. If a
		 * node number 0 was specified, the default is used.
		 */

		ret = -EINVAL;
		if(memcmp(addr->sipx_node,ipx_broadcast_node,IPX_NODE_LEN) == 0)
			goto out;
		if(memcmp(addr->sipx_node, ipx_this_node, IPX_NODE_LEN) == 0)
		{
			memcpy(sk->protinfo.af_ipx.node, intrfc->if_node,
			       IPX_NODE_LEN);
		}
		else
		{
			memcpy(sk->protinfo.af_ipx.node, addr->sipx_node, IPX_NODE_LEN);
		}

		ret = -EADDRINUSE;
		if(ipxitf_find_internal_socket(intrfc,
			sk->protinfo.af_ipx.node,
			sk->protinfo.af_ipx.port) != NULL)
		{
			SOCK_DEBUG(sk,
				"IPX: bind failed because port %X in use.\n",
				ntohs((int)addr->sipx_port));
			goto out;
		}
	}
	else
	{
		/* Source addresses are easy. It must be our
		 * network:node pair for an interface routed to IPX
		 * with the ipx routing ioctl()
		 */

		memcpy(sk->protinfo.af_ipx.node, intrfc->if_node,
			IPX_NODE_LEN);

		ret = -EADDRINUSE;
		if(ipxitf_find_socket(intrfc, addr->sipx_port) != NULL)
		{
			SOCK_DEBUG(sk,
				"IPX: bind failed because port %X in use.\n",
				ntohs((int)addr->sipx_port));
			goto out;
		}
	}

#else	/* !def CONFIG_IPX_INTERN */

	/* Source addresses are easy. It must be our network:node pair for
	   an interface routed to IPX with the ipx routing ioctl() */

	ret = -EADDRINUSE;
	if(ipxitf_find_socket(intrfc, addr->sipx_port) != NULL)
	{
		SOCK_DEBUG(sk, "IPX: bind failed because port %X in use.\n",
				ntohs((int)addr->sipx_port));
		goto out;
	}

#endif	/* CONFIG_IPX_INTERN */

	ipxitf_insert_socket(intrfc, sk);
	sk->zapped = 0;
	SOCK_DEBUG(sk, "IPX: bound socket 0x%04X.\n", ntohs(addr->sipx_port) );

	ret = 0;
out:	ipxitf_put(intrfc);
	return ret;
}

static int ipx_connect(struct socket *sock, struct sockaddr *uaddr,
	int addr_len, int flags)
{
	struct sock *sk = sock->sk;
	struct sockaddr_ipx *addr;

	sk->state	= TCP_CLOSE;
	sock->state 	= SS_UNCONNECTED;

	if(addr_len != sizeof(*addr))
		return (-EINVAL);
	addr = (struct sockaddr_ipx *)uaddr;

	/* put the autobinding in */
	if(sk->protinfo.af_ipx.port == 0)
	{
		struct sockaddr_ipx uaddr;
		int ret;

		uaddr.sipx_port		= 0;
		uaddr.sipx_network 	= 0;