af_decnet.c

linux 内核源代码

static void dn_destroy_sock(struct sock *sk)
{
	struct dn_scp *scp = DN_SK(sk);

	scp->nsp_rxtshift = 0; /* reset back off */

	if (sk->sk_socket) {
		if (sk->sk_socket->state != SS_UNCONNECTED)
			sk->sk_socket->state = SS_DISCONNECTING;
	}

	sk->sk_state = TCP_CLOSE;

	switch(scp->state) {
		case DN_DN:
			dn_nsp_send_disc(sk, NSP_DISCCONF, NSP_REASON_DC,
					 sk->sk_allocation);
			scp->persist_fxn = dn_destroy_timer;
			scp->persist = dn_nsp_persist(sk);
			break;
		case DN_CR:
			scp->state = DN_DR;
			goto disc_reject;
		case DN_RUN:
			scp->state = DN_DI;
		case DN_DI:
		case DN_DR:
disc_reject:
			dn_nsp_send_disc(sk, NSP_DISCINIT, 0, sk->sk_allocation);
		case DN_NC:
		case DN_NR:
		case DN_RJ:
		case DN_DIC:
		case DN_CN:
		case DN_DRC:
		case DN_CI:
		case DN_CD:
			scp->persist_fxn = dn_destroy_timer;
			scp->persist = dn_nsp_persist(sk);
			break;
		default:
			printk(KERN_DEBUG "DECnet: dn_destroy_sock passed socket in invalid state\n");
		case DN_O:
			dn_stop_slow_timer(sk);

			dn_unhash_sock_bh(sk);
			sock_put(sk);

			break;
	}
}

char *dn_addr2asc(__u16 addr, char *buf)
{
	unsigned short node, area;

	node = addr & 0x03ff;
	area = addr >> 10;
	sprintf(buf, "%hd.%hd", area, node);

	return buf;
}



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

	if (net != &init_net)
		return -EAFNOSUPPORT;

	switch(sock->type) {
		case SOCK_SEQPACKET:
			if (protocol != DNPROTO_NSP)
				return -EPROTONOSUPPORT;
			break;
		case SOCK_STREAM:
			break;
		default:
			return -ESOCKTNOSUPPORT;
	}


	if ((sk = dn_alloc_sock(net, sock, GFP_KERNEL)) == NULL)
		return -ENOBUFS;

	sk->sk_protocol = protocol;

	return 0;
}


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

	if (sk) {
		sock_orphan(sk);
		sock_hold(sk);
		lock_sock(sk);
		dn_destroy_sock(sk);
		release_sock(sk);
		sock_put(sk);
	}

	return 0;
}

static int dn_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
	struct sock *sk = sock->sk;
	struct dn_scp *scp = DN_SK(sk);
	struct sockaddr_dn *saddr = (struct sockaddr_dn *)uaddr;
	struct net_device *dev, *ldev;
	int rv;

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

	if (saddr->sdn_family != AF_DECnet)
		return -EINVAL;

	if (dn_ntohs(saddr->sdn_nodeaddrl) && (dn_ntohs(saddr->sdn_nodeaddrl) != 2))
		return -EINVAL;

	if (dn_ntohs(saddr->sdn_objnamel) > DN_MAXOBJL)
		return -EINVAL;

	if (saddr->sdn_flags & ~SDF_WILD)
		return -EINVAL;

	if (!capable(CAP_NET_BIND_SERVICE) && (saddr->sdn_objnum ||
	    (saddr->sdn_flags & SDF_WILD)))
		return -EACCES;

	if (!(saddr->sdn_flags & SDF_WILD)) {
		if (dn_ntohs(saddr->sdn_nodeaddrl)) {
			read_lock(&dev_base_lock);
			ldev = NULL;
			for_each_netdev(&init_net, dev) {
				if (!dev->dn_ptr)
					continue;
				if (dn_dev_islocal(dev, dn_saddr2dn(saddr))) {
					ldev = dev;
					break;
				}
			}
			read_unlock(&dev_base_lock);
			if (ldev == NULL)
				return -EADDRNOTAVAIL;
		}
	}

	rv = -EINVAL;
	lock_sock(sk);
	if (sock_flag(sk, SOCK_ZAPPED)) {
		memcpy(&scp->addr, saddr, addr_len);
		sock_reset_flag(sk, SOCK_ZAPPED);

		rv = dn_hash_sock(sk);
		if (rv)
			sock_set_flag(sk, SOCK_ZAPPED);
	}
	release_sock(sk);

	return rv;
}


static int dn_auto_bind(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct dn_scp *scp = DN_SK(sk);
	int rv;

	sock_reset_flag(sk, SOCK_ZAPPED);

	scp->addr.sdn_flags  = 0;
	scp->addr.sdn_objnum = 0;

	/*
	 * This stuff is to keep compatibility with Eduardo's
	 * patch. I hope I can dispense with it shortly...
	 */
	if ((scp->accessdata.acc_accl != 0) &&
		(scp->accessdata.acc_accl <= 12)) {

		scp->addr.sdn_objnamel = dn_htons(scp->accessdata.acc_accl);
		memcpy(scp->addr.sdn_objname, scp->accessdata.acc_acc, dn_ntohs(scp->addr.sdn_objnamel));

		scp->accessdata.acc_accl = 0;
		memset(scp->accessdata.acc_acc, 0, 40);
	}
	/* End of compatibility stuff */

	scp->addr.sdn_add.a_len = dn_htons(2);
	rv = dn_dev_bind_default((__le16 *)scp->addr.sdn_add.a_addr);
	if (rv == 0) {
		rv = dn_hash_sock(sk);
		if (rv)
			sock_set_flag(sk, SOCK_ZAPPED);
	}

	return rv;
}

static int dn_confirm_accept(struct sock *sk, long *timeo, gfp_t allocation)
{
	struct dn_scp *scp = DN_SK(sk);
	DEFINE_WAIT(wait);
	int err;

	if (scp->state != DN_CR)
		return -EINVAL;

	scp->state = DN_CC;
	scp->segsize_loc = dst_metric(__sk_dst_get(sk), RTAX_ADVMSS);
	dn_send_conn_conf(sk, allocation);

	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
	for(;;) {
		release_sock(sk);
		if (scp->state == DN_CC)
			*timeo = schedule_timeout(*timeo);
		lock_sock(sk);
		err = 0;
		if (scp->state == DN_RUN)
			break;
		err = sock_error(sk);
		if (err)
			break;
		err = sock_intr_errno(*timeo);
		if (signal_pending(current))
			break;
		err = -EAGAIN;
		if (!*timeo)
			break;
		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
	}
	finish_wait(sk->sk_sleep, &wait);
	if (err == 0) {
		sk->sk_socket->state = SS_CONNECTED;
	} else if (scp->state != DN_CC) {
		sk->sk_socket->state = SS_UNCONNECTED;
	}
	return err;
}

static int dn_wait_run(struct sock *sk, long *timeo)
{
	struct dn_scp *scp = DN_SK(sk);
	DEFINE_WAIT(wait);
	int err = 0;

	if (scp->state == DN_RUN)
		goto out;

	if (!*timeo)
		return -EALREADY;

	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
	for(;;) {
		release_sock(sk);
		if (scp->state == DN_CI || scp->state == DN_CC)
			*timeo = schedule_timeout(*timeo);
		lock_sock(sk);
		err = 0;
		if (scp->state == DN_RUN)
			break;
		err = sock_error(sk);
		if (err)
			break;
		err = sock_intr_errno(*timeo);
		if (signal_pending(current))
			break;
		err = -ETIMEDOUT;
		if (!*timeo)
			break;
		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
	}
	finish_wait(sk->sk_sleep, &wait);
out:
	if (err == 0) {
		sk->sk_socket->state = SS_CONNECTED;
	} else if (scp->state != DN_CI && scp->state != DN_CC) {
		sk->sk_socket->state = SS_UNCONNECTED;
	}
	return err;
}

static int __dn_connect(struct sock *sk, struct sockaddr_dn *addr, int addrlen, long *timeo, int flags)
{
	struct socket *sock = sk->sk_socket;
	struct dn_scp *scp = DN_SK(sk);
	int err = -EISCONN;
	struct flowi fl;

	if (sock->state == SS_CONNECTED)
		goto out;

	if (sock->state == SS_CONNECTING) {
		err = 0;
		if (scp->state == DN_RUN) {
			sock->state = SS_CONNECTED;
			goto out;
		}
		err = -ECONNREFUSED;
		if (scp->state != DN_CI && scp->state != DN_CC) {
			sock->state = SS_UNCONNECTED;
			goto out;
		}
		return dn_wait_run(sk, timeo);
	}

	err = -EINVAL;
	if (scp->state != DN_O)
		goto out;

	if (addr == NULL || addrlen != sizeof(struct sockaddr_dn))
		goto out;
	if (addr->sdn_family != AF_DECnet)
		goto out;
	if (addr->sdn_flags & SDF_WILD)
		goto out;

	if (sock_flag(sk, SOCK_ZAPPED)) {
		err = dn_auto_bind(sk->sk_socket);
		if (err)
			goto out;
	}

	memcpy(&scp->peer, addr, sizeof(struct sockaddr_dn));

	err = -EHOSTUNREACH;
	memset(&fl, 0, sizeof(fl));
	fl.oif = sk->sk_bound_dev_if;
	fl.fld_dst = dn_saddr2dn(&scp->peer);
	fl.fld_src = dn_saddr2dn(&scp->addr);
	dn_sk_ports_copy(&fl, scp);
	fl.proto = DNPROTO_NSP;
	if (dn_route_output_sock(&sk->sk_dst_cache, &fl, sk, flags) < 0)
		goto out;
	sk->sk_route_caps = sk->sk_dst_cache->dev->features;
	sock->state = SS_CONNECTING;
	scp->state = DN_CI;
	scp->segsize_loc = dst_metric(sk->sk_dst_cache, RTAX_ADVMSS);

	dn_nsp_send_conninit(sk, NSP_CI);
	err = -EINPROGRESS;
	if (*timeo) {
		err = dn_wait_run(sk, timeo);
	}
out:
	return err;
}

static int dn_connect(struct socket *sock, struct sockaddr *uaddr, int addrlen, int flags)
{
	struct sockaddr_dn *addr = (struct sockaddr_dn *)uaddr;
	struct sock *sk = sock->sk;
	int err;
	long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);

	lock_sock(sk);
	err = __dn_connect(sk, addr, addrlen, &timeo, 0);
	release_sock(sk);

	return err;
}

static inline int dn_check_state(struct sock *sk, struct sockaddr_dn *addr, int addrlen, long *timeo, int flags)
{
	struct dn_scp *scp = DN_SK(sk);

	switch(scp->state) {
		case DN_RUN:
			return 0;
		case DN_CR:
			return dn_confirm_accept(sk, timeo, sk->sk_allocation);
		case DN_CI:
		case DN_CC:
			return dn_wait_run(sk, timeo);
		case DN_O:
			return __dn_connect(sk, addr, addrlen, timeo, flags);
	}

	return -EINVAL;
}


static void dn_access_copy(struct sk_buff *skb, struct accessdata_dn *acc)
{
	unsigned char *ptr = skb->data;

	acc->acc_userl = *ptr++;
	memcpy(&acc->acc_user, ptr, acc->acc_userl);
	ptr += acc->acc_userl;

	acc->acc_passl = *ptr++;
	memcpy(&acc->acc_pass, ptr, acc->acc_passl);
	ptr += acc->acc_passl;

	acc->acc_accl = *ptr++;
	memcpy(&acc->acc_acc, ptr, acc->acc_accl);

	skb_pull(skb, acc->acc_accl + acc->acc_passl + acc->acc_userl + 3);

}

static void dn_user_copy(struct sk_buff *skb, struct optdata_dn *opt)
{
	unsigned char *ptr = skb->data;
	u16 len = *ptr++; /* yes, it's 8bit on the wire */

	BUG_ON(len > 16); /* we've checked the contents earlier */
	opt->opt_optl   = dn_htons(len);
	opt->opt_status = 0;
	memcpy(opt->opt_data, ptr, len);
	skb_pull(skb, len + 1);
}

static struct sk_buff *dn_wait_for_connect(struct sock *sk, long *timeo)
{
	DEFINE_WAIT(wait);
	struct sk_buff *skb = NULL;
	int err = 0;

	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
	for(;;) {
		release_sock(sk);
		skb = skb_dequeue(&sk->sk_receive_queue);
		if (skb == NULL) {
			*timeo = schedule_timeout(*timeo);
			skb = skb_dequeue(&sk->sk_receive_queue);
		}
		lock_sock(sk);
		if (skb != NULL)
			break;
		err = -EINVAL;
		if (sk->sk_state != TCP_LISTEN)
			break;
		err = sock_intr_errno(*timeo);
		if (signal_pending(current))
			break;
		err = -EAGAIN;
		if (!*timeo)
			break;
		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
	}
	finish_wait(sk->sk_sleep, &wait);

	return skb == NULL ? ERR_PTR(err) : skb;
}

static int dn_accept(struct socket *sock, struct socket *newsock, int flags)
{
	struct sock *sk = sock->sk, *newsk;
	struct sk_buff *skb = NULL;
	struct dn_skb_cb *cb;
	unsigned char menuver;
	int err = 0;
	unsigned char type;
	long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);

	lock_sock(sk);

	if (sk->sk_state != TCP_LISTEN || DN_SK(sk)->state != DN_O) {
		release_sock(sk);
		return -EINVAL;
	}

	skb = skb_dequeue(&sk->sk_receive_queue);
	if (skb == NULL) {
		skb = dn_wait_for_connect(sk, &timeo);
		if (IS_ERR(skb)) {
			release_sock(sk);
			return PTR_ERR(skb);
		}
	}

	cb = DN_SKB_CB(skb);
	sk->sk_ack_backlog--;
	newsk = dn_alloc_sock(sk->sk_net, newsock, sk->sk_allocation);
	if (newsk == NULL) {
		release_sock(sk);
		kfree_skb(skb);
		return -ENOBUFS;
	}
	release_sock(sk);

	dst_release(xchg(&newsk->sk_dst_cache, skb->dst));
	skb->dst = NULL;

	DN_SK(newsk)->state        = DN_CR;
	DN_SK(newsk)->addrrem      = cb->src_port;
	DN_SK(newsk)->services_rem = cb->services;
	DN_SK(newsk)->info_rem     = cb->info;
	DN_SK(newsk)->segsize_rem  = cb->segsize;
	DN_SK(newsk)->accept_mode  = DN_SK(sk)->accept_mode;

	if (DN_SK(newsk)->segsize_rem < 230)
		DN_SK(newsk)->segsize_rem = 230;

	if ((DN_SK(newsk)->services_rem & NSP_FC_MASK) == NSP_FC_NONE)
		DN_SK(newsk)->max_window = decnet_no_fc_max_cwnd;

	newsk->sk_state  = TCP_LISTEN;
	memcpy(&(DN_SK(newsk)->addr), &(DN_SK(sk)->addr), sizeof(struct sockaddr_dn));

	/*
	 * If we are listening on a wild socket, we don't want
	 * the newly created socket on the wrong hash queue.
	 */
	DN_SK(newsk)->addr.sdn_flags &= ~SDF_WILD;

	skb_pull(skb, dn_username2sockaddr(skb->data, skb->len, &(DN_SK(newsk)->addr), &type));
	skb_pull(skb, dn_username2sockaddr(skb->data, skb->len, &(DN_SK(newsk)->peer), &type));
	*(__le16 *)(DN_SK(newsk)->peer.sdn_add.a_addr) = cb->src;
	*(__le16 *)(DN_SK(newsk)->addr.sdn_add.a_addr) = cb->dst;

	menuver = *skb->data;
	skb_pull(skb, 1);

	if (menuver & DN_MENUVER_ACC)
		dn_access_copy(skb, &(DN_SK(newsk)->accessdata));

	if (menuver & DN_MENUVER_USR)
		dn_user_copy(skb, &(DN_SK(newsk)->conndata_in));

	if (menuver & DN_MENUVER_PRX)
		DN_SK(newsk)->peer.sdn_flags |= SDF_PROXY;

	if (menuver & DN_MENUVER_UIC)
		DN_SK(newsk)->peer.sdn_flags |= SDF_UICPROXY;

	kfree_skb(skb);

	memcpy(&(DN_SK(newsk)->conndata_out), &(DN_SK(sk)->conndata_out),
		sizeof(struct optdata_dn));
	memcpy(&(DN_SK(newsk)->discdata_out), &(DN_SK(sk)->discdata_out),
		sizeof(struct optdata_dn));

	lock_sock(newsk);
	err = dn_hash_sock(newsk);
	if (err == 0) {
		sock_reset_flag(newsk, SOCK_ZAPPED);
		dn_send_conn_ack(newsk);

		/*
		 * Here we use sk->sk_allocation since although the conn conf is
		 * for the newsk, the context is the old socket.
		 */
		if (DN_SK(newsk)->accept_mode == ACC_IMMED)
			err = dn_confirm_accept(newsk, &timeo,
						sk->sk_allocation);
	}
	release_sock(newsk);
	return err;
}


static int dn_getname(struct socket *sock, struct sockaddr *uaddr,int *uaddr_len,int peer)
{
	struct sockaddr_dn *sa = (struct sockaddr_dn *)uaddr;
	struct sock *sk = sock->sk;
	struct dn_scp *scp = DN_SK(sk);

	*uaddr_len = sizeof(struct sockaddr_dn);

	lock_sock(sk);

	if (peer) {
		if ((sock->state != SS_CONNECTED &&
		     sock->state != SS_CONNECTING) &&
		    scp->accept_mode == ACC_IMMED) {
			release_sock(sk);
			return -ENOTCONN;
		}

		memcpy(sa, &scp->peer, sizeof(struct sockaddr_dn));
	} else {
		memcpy(sa, &scp->addr, sizeof(struct sockaddr_dn));
	}

	release_sock(sk);

	return 0;
}


static unsigned int dn_poll(struct file *file, struct socket *sock, poll_table  *wait)
{
	struct sock *sk = sock->sk;
	struct dn_scp *scp = DN_SK(sk);
	int mask = datagram_poll(file, sock, wait);

	if (!skb_queue_empty(&scp->other_receive_queue))
		mask |= POLLRDBAND;

	return mask;
}

static int dn_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;
	struct dn_scp *scp = DN_SK(sk);
	int err = -EOPNOTSUPP;
	long amount = 0;