[linux-block.git] / net / atm / signaling.c

// SPDX-License-Identifier: GPL-2.0
/* net/atm/signaling.c - ATM signaling */

/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#include <linux/errno.h>	/* error codes */
#include <linux/kernel.h>	/* printk */
#include <linux/skbuff.h>
#include <linux/wait.h>
#include <linux/sched.h>	/* jiffies and HZ */
#include <linux/atm.h>		/* ATM stuff */
#include <linux/atmsap.h>
#include <linux/atmsvc.h>
#include <linux/atmdev.h>
#include <linux/bitops.h>
#include <linux/slab.h>

#include "resources.h"
#include "signaling.h"

struct atm_vcc *sigd = NULL;

static void sigd_put_skb(struct sk_buff *skb)
{
	if (!sigd) {
		pr_debug("atmsvc: no signaling daemon\n");
		kfree_skb(skb);
		return;
	}
	atm_force_charge(sigd, skb->truesize);
	skb_queue_tail(&sk_atm(sigd)->sk_receive_queue, skb);
	sk_atm(sigd)->sk_data_ready(sk_atm(sigd));
}

static void modify_qos(struct atm_vcc *vcc, struct atmsvc_msg *msg)
{
	struct sk_buff *skb;

	if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
	    !test_bit(ATM_VF_READY, &vcc->flags))
		return;
	msg->type = as_error;
	if (!vcc->dev->ops->change_qos)
		msg->reply = -EOPNOTSUPP;
	else {
		/* should lock VCC */
		msg->reply = vcc->dev->ops->change_qos(vcc, &msg->qos,
						       msg->reply);
		if (!msg->reply)
			msg->type = as_okay;
	}
	/*
	 * Should probably just turn around the old skb. But the, the buffer
	 * space accounting needs to follow the change too. Maybe later.
	 */
	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
		schedule();
	*(struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)) = *msg;
	sigd_put_skb(skb);
}

static int sigd_send(struct atm_vcc *vcc, struct sk_buff *skb)
{
	struct atmsvc_msg *msg;
	struct atm_vcc *session_vcc;
	struct sock *sk;

	msg = (struct atmsvc_msg *) skb->data;
	WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc));
	vcc = *(struct atm_vcc **) &msg->vcc;
	pr_debug("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc);
	sk = sk_atm(vcc);

	switch (msg->type) {
	case as_okay:
		sk->sk_err = -msg->reply;
		clear_bit(ATM_VF_WAITING, &vcc->flags);
		if (!*vcc->local.sas_addr.prv && !*vcc->local.sas_addr.pub) {
			vcc->local.sas_family = AF_ATMSVC;
			memcpy(vcc->local.sas_addr.prv,
			       msg->local.sas_addr.prv, ATM_ESA_LEN);
			memcpy(vcc->local.sas_addr.pub,
			       msg->local.sas_addr.pub, ATM_E164_LEN + 1);
		}
		session_vcc = vcc->session ? vcc->session : vcc;
		if (session_vcc->vpi || session_vcc->vci)
			break;
		session_vcc->itf = msg->pvc.sap_addr.itf;
		session_vcc->vpi = msg->pvc.sap_addr.vpi;
		session_vcc->vci = msg->pvc.sap_addr.vci;
		if (session_vcc->vpi || session_vcc->vci)
			session_vcc->qos = msg->qos;
		break;
	case as_error:
		clear_bit(ATM_VF_REGIS, &vcc->flags);
		clear_bit(ATM_VF_READY, &vcc->flags);
		sk->sk_err = -msg->reply;
		clear_bit(ATM_VF_WAITING, &vcc->flags);
		break;
	case as_indicate:
		vcc = *(struct atm_vcc **)&msg->listen_vcc;
		sk = sk_atm(vcc);
		pr_debug("as_indicate!!!\n");
		lock_sock(sk);
		if (sk_acceptq_is_full(sk)) {
			sigd_enq(NULL, as_reject, vcc, NULL, NULL);
			dev_kfree_skb(skb);
			goto as_indicate_complete;
		}
		sk->sk_ack_backlog++;
		skb_queue_tail(&sk->sk_receive_queue, skb);
		pr_debug("waking sk_sleep(sk) 0x%p\n", sk_sleep(sk));
		sk->sk_state_change(sk);
as_indicate_complete:
		release_sock(sk);
		return 0;
	case as_close:
		set_bit(ATM_VF_RELEASED, &vcc->flags);
		vcc_release_async(vcc, msg->reply);
		goto out;
	case as_modify:
		modify_qos(vcc, msg);
		break;
	case as_addparty:
	case as_dropparty:
		sk->sk_err_soft = -msg->reply;
					/* < 0 failure, otherwise ep_ref */
		clear_bit(ATM_VF_WAITING, &vcc->flags);
		break;
	default:
		pr_alert("bad message type %d\n", (int)msg->type);
		return -EINVAL;
	}
	sk->sk_state_change(sk);
out:
	dev_kfree_skb(skb);
	return 0;
}

void sigd_enq2(struct atm_vcc *vcc, enum atmsvc_msg_type type,
	       struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc,
	       const struct sockaddr_atmsvc *svc, const struct atm_qos *qos,
	       int reply)
{
	struct sk_buff *skb;
	struct atmsvc_msg *msg;
	static unsigned int session = 0;

	pr_debug("%d (0x%p)\n", (int)type, vcc);
	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
		schedule();
	msg = skb_put_zero(skb, sizeof(struct atmsvc_msg));
	msg->type = type;
	*(struct atm_vcc **) &msg->vcc = vcc;
	*(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
	msg->reply = reply;
	if (qos)
		msg->qos = *qos;
	if (vcc)
		msg->sap = vcc->sap;
	if (svc)
		msg->svc = *svc;
	if (vcc)
		msg->local = vcc->local;
	if (pvc)
		msg->pvc = *pvc;
	if (vcc) {
		if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
			msg->session = ++session;
			/* every new pmp connect gets the next session number */
	}
	sigd_put_skb(skb);
	if (vcc)
		set_bit(ATM_VF_REGIS, &vcc->flags);
}

void sigd_enq(struct atm_vcc *vcc, enum atmsvc_msg_type type,
	      struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc,
	      const struct sockaddr_atmsvc *svc)
{
	sigd_enq2(vcc, type, listen_vcc, pvc, svc, vcc ? &vcc->qos : NULL, 0);
	/* other ISP applications may use "reply" */
}

static void purge_vcc(struct atm_vcc *vcc)
{
	if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
	    !test_bit(ATM_VF_META, &vcc->flags)) {
		set_bit(ATM_VF_RELEASED, &vcc->flags);
		clear_bit(ATM_VF_REGIS, &vcc->flags);
		vcc_release_async(vcc, -EUNATCH);
	}
}

static void sigd_close(struct atm_vcc *vcc)
{
	struct sock *s;
	int i;

	pr_debug("\n");
	sigd = NULL;
	if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
		pr_err("closing with requests pending\n");
	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);

	read_lock(&vcc_sklist_lock);
	for (i = 0; i < VCC_HTABLE_SIZE; ++i) {
		struct hlist_head *head = &vcc_hash[i];

		sk_for_each(s, head) {
			vcc = atm_sk(s);

			purge_vcc(vcc);
		}
	}
	read_unlock(&vcc_sklist_lock);
}

static const struct atmdev_ops sigd_dev_ops = {
	.close = sigd_close,
	.send =	sigd_send
};

static struct atm_dev sigd_dev = {
	.ops =		&sigd_dev_ops,
	.type =		"sig",
	.number =	999,
	.lock =		__SPIN_LOCK_UNLOCKED(sigd_dev.lock)
};

int sigd_attach(struct atm_vcc *vcc)
{
	if (sigd)
		return -EADDRINUSE;
	pr_debug("\n");
	sigd = vcc;
	vcc->dev = &sigd_dev;
	vcc_insert_socket(sk_atm(vcc));
	set_bit(ATM_VF_META, &vcc->flags);
	set_bit(ATM_VF_READY, &vcc->flags);
	return 0;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/* net/atm/signaling.c - ATM signaling */
	3
	4	/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
	5
99824461	6	#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
1da177e4 LT	7
	8	#include <linux/errno.h> /* error codes */
	9	#include <linux/kernel.h> /* printk */
	10	#include <linux/skbuff.h>
	11	#include <linux/wait.h>
	12	#include <linux/sched.h> /* jiffies and HZ */
	13	#include <linux/atm.h> /* ATM stuff */
	14	#include <linux/atmsap.h>
	15	#include <linux/atmsvc.h>
	16	#include <linux/atmdev.h>
	17	#include <linux/bitops.h>
5a0e3ad6	18	#include <linux/slab.h>
1da177e4 LT	19
	20	#include "resources.h"
	21	#include "signaling.h"
	22
1da177e4	23	struct atm_vcc *sigd = NULL;
1da177e4	24
1da177e4 LT	25	static void sigd_put_skb(struct sk_buff *skb)
1da177e4 LT	26	{
1da177e4	27	if (!sigd) {
99824461	28	pr_debug("atmsvc: no signaling daemon\n");
1da177e4 LT	29	kfree_skb(skb);
	30	return;
	31	}
0ec96e65 JP	32	atm_force_charge(sigd, skb->truesize);
0ec96e65 JP	33	skb_queue_tail(&sk_atm(sigd)->sk_receive_queue, skb);
676d2369	34	sk_atm(sigd)->sk_data_ready(sk_atm(sigd));
1da177e4 LT	35	}
1da177e4 LT	36
0ec96e65	37	static void modify_qos(struct atm_vcc vcc, struct atmsvc_msg msg)
1da177e4 LT	38	{
	39	struct sk_buff *skb;
	40
0ec96e65 JP	41	if (test_bit(ATM_VF_RELEASED, &vcc->flags) \|\|
0ec96e65 JP	42	!test_bit(ATM_VF_READY, &vcc->flags))
1da177e4 LT	43	return;
1da177e4 LT	44	msg->type = as_error;
0ec96e65 JP	45	if (!vcc->dev->ops->change_qos)
0ec96e65 JP	46	msg->reply = -EOPNOTSUPP;
1da177e4 LT	47	else {
1da177e4 LT	48	/* should lock VCC */
0ec96e65 JP	49	msg->reply = vcc->dev->ops->change_qos(vcc, &msg->qos,
	50	msg->reply);
	51	if (!msg->reply)
	52	msg->type = as_okay;
1da177e4 LT	53	}
	54	/*
	55	* Should probably just turn around the old skb. But the, the buffer
	56	* space accounting needs to follow the change too. Maybe later.
	57	*/
0ec96e65	58	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
1da177e4	59	schedule();
0ec96e65	60	(struct atmsvc_msg )skb_put(skb, sizeof(struct atmsvc_msg)) = *msg;
1da177e4 LT	61	sigd_put_skb(skb);
	62	}
	63
0ec96e65	64	static int sigd_send(struct atm_vcc vcc, struct sk_buff skb)
1da177e4 LT	65	{
	66	struct atmsvc_msg *msg;
	67	struct atm_vcc *session_vcc;
	68	struct sock *sk;
	69
	70	msg = (struct atmsvc_msg *) skb->data;
14afee4b	71	WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc));
1da177e4	72	vcc = (struct atm_vcc *) &msg->vcc;
99824461	73	pr_debug("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc);
1da177e4 LT	74	sk = sk_atm(vcc);
	75
	76	switch (msg->type) {
0ec96e65 JP	77	case as_okay:
	78	sk->sk_err = -msg->reply;
	79	clear_bit(ATM_VF_WAITING, &vcc->flags);
	80	if (!vcc->local.sas_addr.prv && !vcc->local.sas_addr.pub) {
	81	vcc->local.sas_family = AF_ATMSVC;
	82	memcpy(vcc->local.sas_addr.prv,
	83	msg->local.sas_addr.prv, ATM_ESA_LEN);
	84	memcpy(vcc->local.sas_addr.pub,
	85	msg->local.sas_addr.pub, ATM_E164_LEN + 1);
	86	}
	87	session_vcc = vcc->session ? vcc->session : vcc;
	88	if (session_vcc->vpi \|\| session_vcc->vci)
1da177e4	89	break;
0ec96e65 JP	90	session_vcc->itf = msg->pvc.sap_addr.itf;
	91	session_vcc->vpi = msg->pvc.sap_addr.vpi;
	92	session_vcc->vci = msg->pvc.sap_addr.vci;
	93	if (session_vcc->vpi \|\| session_vcc->vci)
	94	session_vcc->qos = msg->qos;
	95	break;
	96	case as_error:
	97	clear_bit(ATM_VF_REGIS, &vcc->flags);
	98	clear_bit(ATM_VF_READY, &vcc->flags);
	99	sk->sk_err = -msg->reply;
	100	clear_bit(ATM_VF_WAITING, &vcc->flags);
	101	break;
	102	case as_indicate:
	103	vcc = (struct atm_vcc *)&msg->listen_vcc;
	104	sk = sk_atm(vcc);
	105	pr_debug("as_indicate!!!\n");
	106	lock_sock(sk);
	107	if (sk_acceptq_is_full(sk)) {
	108	sigd_enq(NULL, as_reject, vcc, NULL, NULL);
	109	dev_kfree_skb(skb);
	110	goto as_indicate_complete;
	111	}
	112	sk->sk_ack_backlog++;
	113	skb_queue_tail(&sk->sk_receive_queue, skb);
aa395145	114	pr_debug("waking sk_sleep(sk) 0x%p\n", sk_sleep(sk));
0ec96e65	115	sk->sk_state_change(sk);
1da177e4	116	as_indicate_complete:
0ec96e65 JP	117	release_sock(sk);
	118	return 0;
	119	case as_close:
	120	set_bit(ATM_VF_RELEASED, &vcc->flags);
	121	vcc_release_async(vcc, msg->reply);
	122	goto out;
	123	case as_modify:
	124	modify_qos(vcc, msg);
	125	break;
	126	case as_addparty:
	127	case as_dropparty:
c685293a	128	sk->sk_err_soft = -msg->reply;
0ec96e65 JP	129	/* < 0 failure, otherwise ep_ref */
	130	clear_bit(ATM_VF_WAITING, &vcc->flags);
	131	break;
	132	default:
	133	pr_alert("bad message type %d\n", (int)msg->type);
	134	return -EINVAL;
1da177e4 LT	135	}
	136	sk->sk_state_change(sk);
	137	out:
	138	dev_kfree_skb(skb);
	139	return 0;
	140	}
	141
0ec96e65 JP	142	void sigd_enq2(struct atm_vcc *vcc, enum atmsvc_msg_type type,
	143	struct atm_vcc listen_vcc, const struct sockaddr_atmpvc pvc,
	144	const struct sockaddr_atmsvc svc, const struct atm_qos qos,
	145	int reply)
1da177e4 LT	146	{
	147	struct sk_buff *skb;
	148	struct atmsvc_msg *msg;
95c96174	149	static unsigned int session = 0;
1da177e4	150
99824461	151	pr_debug("%d (0x%p)\n", (int)type, vcc);
0ec96e65	152	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
1da177e4	153	schedule();
b080db58	154	msg = skb_put_zero(skb, sizeof(struct atmsvc_msg));
1da177e4 LT	155	msg->type = type;
	156	(struct atm_vcc *) &msg->vcc = vcc;
	157	(struct atm_vcc *) &msg->listen_vcc = listen_vcc;
	158	msg->reply = reply;
0ec96e65 JP	159	if (qos)
	160	msg->qos = *qos;
	161	if (vcc)
	162	msg->sap = vcc->sap;
	163	if (svc)
	164	msg->svc = *svc;
	165	if (vcc)
	166	msg->local = vcc->local;
	167	if (pvc)
	168	msg->pvc = *pvc;
1da177e4 LT	169	if (vcc) {
	170	if (type == as_connect && test_bit(ATM_VF_SESSION, &vcc->flags))
	171	msg->session = ++session;
	172	/* every new pmp connect gets the next session number */
	173	}
	174	sigd_put_skb(skb);
0ec96e65 JP	175	if (vcc)
0ec96e65 JP	176	set_bit(ATM_VF_REGIS, &vcc->flags);
1da177e4 LT	177	}
1da177e4 LT	178
0ec96e65 JP	179	void sigd_enq(struct atm_vcc *vcc, enum atmsvc_msg_type type,
	180	struct atm_vcc listen_vcc, const struct sockaddr_atmpvc pvc,
	181	const struct sockaddr_atmsvc *svc)
1da177e4	182	{
0ec96e65	183	sigd_enq2(vcc, type, listen_vcc, pvc, svc, vcc ? &vcc->qos : NULL, 0);
1da177e4 LT	184	/* other ISP applications may use "reply" */
	185	}
	186
1da177e4 LT	187	static void purge_vcc(struct atm_vcc *vcc)
	188	{
	189	if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
9301e320 CW	190	!test_bit(ATM_VF_META, &vcc->flags)) {
	191	set_bit(ATM_VF_RELEASED, &vcc->flags);
	192	clear_bit(ATM_VF_REGIS, &vcc->flags);
1da177e4 LT	193	vcc_release_async(vcc, -EUNATCH);
	194	}
	195	}
	196
1da177e4 LT	197	static void sigd_close(struct atm_vcc *vcc)
1da177e4 LT	198	{
1da177e4 LT	199	struct sock *s;
	200	int i;
	201
99824461	202	pr_debug("\n");
1da177e4 LT	203	sigd = NULL;
1da177e4 LT	204	if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
99824461	205	pr_err("closing with requests pending\n");
1da177e4 LT	206	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
	207
	208	read_lock(&vcc_sklist_lock);
0ec96e65	209	for (i = 0; i < VCC_HTABLE_SIZE; ++i) {
1da177e4 LT	210	struct hlist_head *head = &vcc_hash[i];
1da177e4 LT	211
b67bfe0d	212	sk_for_each(s, head) {
cfcabdcc	213	vcc = atm_sk(s);
1da177e4	214
9301e320	215	purge_vcc(vcc);
1da177e4 LT	216	}
	217	}
	218	read_unlock(&vcc_sklist_lock);
	219	}
	220
800bb47e	221	static const struct atmdev_ops sigd_dev_ops = {
1da177e4 LT	222	.close = sigd_close,
	223	.send = sigd_send
	224	};
	225
1da177e4 LT	226	static struct atm_dev sigd_dev = {
	227	.ops = &sigd_dev_ops,
	228	.type = "sig",
	229	.number = 999,
4ef8d0ae	230	.lock = __SPIN_LOCK_UNLOCKED(sigd_dev.lock)
1da177e4 LT	231	};
1da177e4 LT	232
1da177e4 LT	233	int sigd_attach(struct atm_vcc *vcc)
1da177e4 LT	234	{
0ec96e65 JP	235	if (sigd)
0ec96e65 JP	236	return -EADDRINUSE;
99824461	237	pr_debug("\n");
1da177e4 LT	238	sigd = vcc;
	239	vcc->dev = &sigd_dev;
	240	vcc_insert_socket(sk_atm(vcc));
0ec96e65 JP	241	set_bit(ATM_VF_META, &vcc->flags);
0ec96e65 JP	242	set_bit(ATM_VF_READY, &vcc->flags);
1da177e4 LT	243	return 0;
1da177e4 LT	244	}