af_iucv.c

linux 内核源代码

/*
 *  linux/net/iucv/af_iucv.c
 *
 *  IUCV protocol stack for Linux on zSeries
 *
 *  Copyright 2006 IBM Corporation
 *
 *  Author(s):	Jennifer Hunt <[e-mail]>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <net/sock.h>
#include <asm/ebcdic.h>
#include <asm/cpcmd.h>
#include <linux/kmod.h>

#include <net/iucv/iucv.h>
#include <net/iucv/af_iucv.h>

#define CONFIG_IUCV_SOCK_DEBUG 1

#define IPRMDATA 0x80
#define VERSION "1.0"

static char iucv_userid[80];

static struct proto_ops iucv_sock_ops;

static struct proto iucv_proto = {
	.name		= "AF_IUCV",
	.owner		= THIS_MODULE,
	.obj_size	= sizeof(struct iucv_sock),
};

static void iucv_sock_kill(struct sock *sk);
static void iucv_sock_close(struct sock *sk);

/* Call Back functions */
static void iucv_callback_rx(struct iucv_path *, struct iucv_message *);
static void iucv_callback_txdone(struct iucv_path *, struct iucv_message *);
static void iucv_callback_connack(struct iucv_path *, u8 ipuser[16]);
static int iucv_callback_connreq(struct iucv_path *, u8 ipvmid[8],
				 u8 ipuser[16]);
static void iucv_callback_connrej(struct iucv_path *, u8 ipuser[16]);

static struct iucv_sock_list iucv_sk_list = {
	.lock = RW_LOCK_UNLOCKED,
	.autobind_name = ATOMIC_INIT(0)
};

static struct iucv_handler af_iucv_handler = {
	.path_pending	  = iucv_callback_connreq,
	.path_complete	  = iucv_callback_connack,
	.path_severed	  = iucv_callback_connrej,
	.message_pending  = iucv_callback_rx,
	.message_complete = iucv_callback_txdone
};

static inline void high_nmcpy(unsigned char *dst, char *src)
{
       memcpy(dst, src, 8);
}

static inline void low_nmcpy(unsigned char *dst, char *src)
{
       memcpy(&dst[8], src, 8);
}

/* Timers */
static void iucv_sock_timeout(unsigned long arg)
{
	struct sock *sk = (struct sock *)arg;

	bh_lock_sock(sk);
	sk->sk_err = ETIMEDOUT;
	sk->sk_state_change(sk);
	bh_unlock_sock(sk);

	iucv_sock_kill(sk);
	sock_put(sk);
}

static void iucv_sock_clear_timer(struct sock *sk)
{
	sk_stop_timer(sk, &sk->sk_timer);
}

static void iucv_sock_init_timer(struct sock *sk)
{
	init_timer(&sk->sk_timer);
	sk->sk_timer.function = iucv_sock_timeout;
	sk->sk_timer.data = (unsigned long)sk;
}

static struct sock *__iucv_get_sock_by_name(char *nm)
{
	struct sock *sk;
	struct hlist_node *node;

	sk_for_each(sk, node, &iucv_sk_list.head)
		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
			return sk;

	return NULL;
}

static void iucv_sock_destruct(struct sock *sk)
{
	skb_queue_purge(&sk->sk_receive_queue);
	skb_queue_purge(&sk->sk_write_queue);
}

/* Cleanup Listen */
static void iucv_sock_cleanup_listen(struct sock *parent)
{
	struct sock *sk;

	/* Close non-accepted connections */
	while ((sk = iucv_accept_dequeue(parent, NULL))) {
		iucv_sock_close(sk);
		iucv_sock_kill(sk);
	}

	parent->sk_state = IUCV_CLOSED;
	sock_set_flag(parent, SOCK_ZAPPED);
}

/* Kill socket */
static void iucv_sock_kill(struct sock *sk)
{
	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
		return;

	iucv_sock_unlink(&iucv_sk_list, sk);
	sock_set_flag(sk, SOCK_DEAD);
	sock_put(sk);
}

/* Close an IUCV socket */
static void iucv_sock_close(struct sock *sk)
{
	unsigned char user_data[16];
	struct iucv_sock *iucv = iucv_sk(sk);
	int err;
	unsigned long timeo;

	iucv_sock_clear_timer(sk);
	lock_sock(sk);

	switch (sk->sk_state) {
	case IUCV_LISTEN:
		iucv_sock_cleanup_listen(sk);
		break;

	case IUCV_CONNECTED:
	case IUCV_DISCONN:
		err = 0;

		sk->sk_state = IUCV_CLOSING;
		sk->sk_state_change(sk);

		if (!skb_queue_empty(&iucv->send_skb_q)) {
			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
				timeo = sk->sk_lingertime;
			else
				timeo = IUCV_DISCONN_TIMEOUT;
			err = iucv_sock_wait_state(sk, IUCV_CLOSED, 0, timeo);
		}

		sk->sk_state = IUCV_CLOSED;
		sk->sk_state_change(sk);

		if (iucv->path) {
			low_nmcpy(user_data, iucv->src_name);
			high_nmcpy(user_data, iucv->dst_name);
			ASCEBC(user_data, sizeof(user_data));
			err = iucv_path_sever(iucv->path, user_data);
			iucv_path_free(iucv->path);
			iucv->path = NULL;
		}

		sk->sk_err = ECONNRESET;
		sk->sk_state_change(sk);

		skb_queue_purge(&iucv->send_skb_q);
		skb_queue_purge(&iucv->backlog_skb_q);

		sock_set_flag(sk, SOCK_ZAPPED);
		break;

	default:
		sock_set_flag(sk, SOCK_ZAPPED);
		break;
	}

	release_sock(sk);
	iucv_sock_kill(sk);
}

static void iucv_sock_init(struct sock *sk, struct sock *parent)
{
	if (parent)
		sk->sk_type = parent->sk_type;
}

static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
{
	struct sock *sk;

	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto);
	if (!sk)
		return NULL;

	sock_init_data(sock, sk);
	INIT_LIST_HEAD(&iucv_sk(sk)->accept_q);
	spin_lock_init(&iucv_sk(sk)->accept_q_lock);
	skb_queue_head_init(&iucv_sk(sk)->send_skb_q);
	INIT_LIST_HEAD(&iucv_sk(sk)->message_q.list);
	spin_lock_init(&iucv_sk(sk)->message_q.lock);
	skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q);
	iucv_sk(sk)->send_tag = 0;

	sk->sk_destruct = iucv_sock_destruct;
	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
	sk->sk_allocation = GFP_DMA;

	sock_reset_flag(sk, SOCK_ZAPPED);

	sk->sk_protocol = proto;
	sk->sk_state	= IUCV_OPEN;

	iucv_sock_init_timer(sk);

	iucv_sock_link(&iucv_sk_list, sk);
	return sk;
}

/* Create an IUCV socket */
static int iucv_sock_create(struct net *net, struct socket *sock, int protocol)
{
	struct sock *sk;

	if (sock->type != SOCK_STREAM)
		return -ESOCKTNOSUPPORT;

	sock->state = SS_UNCONNECTED;
	sock->ops = &iucv_sock_ops;

	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
	if (!sk)
		return -ENOMEM;

	iucv_sock_init(sk, NULL);

	return 0;
}

void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
{
	write_lock_bh(&l->lock);
	sk_add_node(sk, &l->head);
	write_unlock_bh(&l->lock);
}

void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
{
	write_lock_bh(&l->lock);
	sk_del_node_init(sk);
	write_unlock_bh(&l->lock);
}

void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
{
	unsigned long flags;
	struct iucv_sock *par = iucv_sk(parent);

	sock_hold(sk);
	spin_lock_irqsave(&par->accept_q_lock, flags);
	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
	spin_unlock_irqrestore(&par->accept_q_lock, flags);
	iucv_sk(sk)->parent = parent;
	parent->sk_ack_backlog++;
}

void iucv_accept_unlink(struct sock *sk)
{
	unsigned long flags;
	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);

	spin_lock_irqsave(&par->accept_q_lock, flags);
	list_del_init(&iucv_sk(sk)->accept_q);
	spin_unlock_irqrestore(&par->accept_q_lock, flags);
	iucv_sk(sk)->parent->sk_ack_backlog--;
	iucv_sk(sk)->parent = NULL;
	sock_put(sk);
}

struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock)
{
	struct iucv_sock *isk, *n;
	struct sock *sk;

	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
		sk = (struct sock *) isk;
		lock_sock(sk);

		if (sk->sk_state == IUCV_CLOSED) {
			iucv_accept_unlink(sk);
			release_sock(sk);
			continue;
		}

		if (sk->sk_state == IUCV_CONNECTED ||
		    sk->sk_state == IUCV_SEVERED ||
		    !newsock) {
			iucv_accept_unlink(sk);
			if (newsock)
				sock_graft(sk, newsock);

			if (sk->sk_state == IUCV_SEVERED)
				sk->sk_state = IUCV_DISCONN;

			release_sock(sk);
			return sk;
		}

		release_sock(sk);
	}
	return NULL;
}

int iucv_sock_wait_state(struct sock *sk, int state, int state2,
			 unsigned long timeo)
{
	DECLARE_WAITQUEUE(wait, current);
	int err = 0;

	add_wait_queue(sk->sk_sleep, &wait);
	while (sk->sk_state != state && sk->sk_state != state2) {
		set_current_state(TASK_INTERRUPTIBLE);

		if (!timeo) {
			err = -EAGAIN;
			break;
		}

		if (signal_pending(current)) {
			err = sock_intr_errno(timeo);
			break;
		}

		release_sock(sk);
		timeo = schedule_timeout(timeo);
		lock_sock(sk);

		err = sock_error(sk);
		if (err)
			break;
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(sk->sk_sleep, &wait);
	return err;
}

/* Bind an unbound socket */
static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
			  int addr_len)
{
	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv;
	int err;

	/* Verify the input sockaddr */
	if (!addr || addr->sa_family != AF_IUCV)
		return -EINVAL;

	lock_sock(sk);
	if (sk->sk_state != IUCV_OPEN) {
		err = -EBADFD;
		goto done;
	}

	write_lock_bh(&iucv_sk_list.lock);

	iucv = iucv_sk(sk);
	if (__iucv_get_sock_by_name(sa->siucv_name)) {
		err = -EADDRINUSE;
		goto done_unlock;
	}
	if (iucv->path) {
		err = 0;
		goto done_unlock;
	}

	/* Bind the socket */
	memcpy(iucv->src_name, sa->siucv_name, 8);

	/* Copy the user id */
	memcpy(iucv->src_user_id, iucv_userid, 8);
	sk->sk_state = IUCV_BOUND;
	err = 0;

done_unlock:
	/* Release the socket list lock */
	write_unlock_bh(&iucv_sk_list.lock);
done:
	release_sock(sk);
	return err;
}

/* Automatically bind an unbound socket */
static int iucv_sock_autobind(struct sock *sk)
{
	struct iucv_sock *iucv = iucv_sk(sk);
	char query_buffer[80];
	char name[12];
	int err = 0;

	/* Set the userid and name */
	cpcmd("QUERY USERID", query_buffer, sizeof(query_buffer), &err);
	if (unlikely(err))
		return -EPROTO;

	memcpy(iucv->src_user_id, query_buffer, 8);

	write_lock_bh(&iucv_sk_list.lock);

	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
	while (__iucv_get_sock_by_name(name)) {
		sprintf(name, "%08x",
			atomic_inc_return(&iucv_sk_list.autobind_name));
	}

	write_unlock_bh(&iucv_sk_list.lock);

	memcpy(&iucv->src_name, name, 8);

	return err;
}

/* Connect an unconnected socket */
static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
			     int alen, int flags)
{
	struct sockaddr_iucv *sa = (struct sockaddr_iucv *) addr;
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv;
	unsigned char user_data[16];
	int err;

	if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
		return -EINVAL;

	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
		return -EBADFD;

	if (sk->sk_type != SOCK_STREAM)
		return -EINVAL;

	iucv = iucv_sk(sk);

	if (sk->sk_state == IUCV_OPEN) {
		err = iucv_sock_autobind(sk);
		if (unlikely(err))
			return err;
	}

	lock_sock(sk);

	/* Set the destination information */
	memcpy(iucv_sk(sk)->dst_user_id, sa->siucv_user_id, 8);
	memcpy(iucv_sk(sk)->dst_name, sa->siucv_name, 8);

	high_nmcpy(user_data, sa->siucv_name);
	low_nmcpy(user_data, iucv_sk(sk)->src_name);
	ASCEBC(user_data, sizeof(user_data));

	iucv = iucv_sk(sk);
	/* Create path. */
	iucv->path = iucv_path_alloc(IUCV_QUEUELEN_DEFAULT,
				     IPRMDATA, GFP_KERNEL);
	err = iucv_path_connect(iucv->path, &af_iucv_handler,
				sa->siucv_user_id, NULL, user_data, sk);
	if (err) {
		iucv_path_free(iucv->path);
		iucv->path = NULL;
		err = -ECONNREFUSED;
		goto done;
	}

	if (sk->sk_state != IUCV_CONNECTED) {
		err = iucv_sock_wait_state(sk, IUCV_CONNECTED, IUCV_DISCONN,
				sock_sndtimeo(sk, flags & O_NONBLOCK));
	}

	if (sk->sk_state == IUCV_DISCONN) {
		release_sock(sk);
		return -ECONNREFUSED;
	}
done:
	release_sock(sk);
	return err;
}

/* Move a socket into listening state. */
static int iucv_sock_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;
	int err;

	lock_sock(sk);

	err = -EINVAL;
	if (sk->sk_state != IUCV_BOUND || sock->type != SOCK_STREAM)
		goto done;

	sk->sk_max_ack_backlog = backlog;
	sk->sk_ack_backlog = 0;
	sk->sk_state = IUCV_LISTEN;
	err = 0;

done:
	release_sock(sk);
	return err;
}

/* Accept a pending connection */
static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
			    int flags)
{
	DECLARE_WAITQUEUE(wait, current);
	struct sock *sk = sock->sk, *nsk;
	long timeo;
	int err = 0;

	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);

	if (sk->sk_state != IUCV_LISTEN) {
		err = -EBADFD;
		goto done;
	}

	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);

	/* Wait for an incoming connection */
	add_wait_queue_exclusive(sk->sk_sleep, &wait);
	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (!timeo) {
			err = -EAGAIN;
			break;
		}

		release_sock(sk);
		timeo = schedule_timeout(timeo);
		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);

		if (sk->sk_state != IUCV_LISTEN) {
			err = -EBADFD;
			break;
		}

		if (signal_pending(current)) {
			err = sock_intr_errno(timeo);
			break;
		}
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(sk->sk_sleep, &wait);

	if (err)
		goto done;

	newsock->state = SS_CONNECTED;

done:
	release_sock(sk);
	return err;
}

static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
			     int *len, int peer)
{
	struct sockaddr_iucv *siucv = (struct sockaddr_iucv *) addr;
	struct sock *sk = sock->sk;

	addr->sa_family = AF_IUCV;
	*len = sizeof(struct sockaddr_iucv);

	if (peer) {
		memcpy(siucv->siucv_user_id, iucv_sk(sk)->dst_user_id, 8);
		memcpy(siucv->siucv_name, &iucv_sk(sk)->dst_name, 8);
	} else {
		memcpy(siucv->siucv_user_id, iucv_sk(sk)->src_user_id, 8);
		memcpy(siucv->siucv_name, iucv_sk(sk)->src_name, 8);
	}
	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
	memset(siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));

	return 0;
}

static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
			     struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;