1/* net/atm/signaling.c - ATM signaling */
2
3/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
4
5#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
6
7#include <linux/errno.h>	/* error codes */
8#include <linux/kernel.h>	/* printk */
9#include <linux/skbuff.h>
10#include <linux/wait.h>
11#include <linux/sched.h>	/* jiffies and HZ */
12#include <linux/atm.h>		/* ATM stuff */
13#include <linux/atmsap.h>
14#include <linux/atmsvc.h>
15#include <linux/atmdev.h>
16#include <linux/bitops.h>
17#include <linux/slab.h>
18
19#include "resources.h"
20#include "signaling.h"
21
22struct atm_vcc *sigd = NULL;
23
24static void sigd_put_skb(struct sk_buff *skb)
25{
26	if (!sigd) {
27		pr_debug("atmsvc: no signaling daemon\n");
28		kfree_skb(skb);
29		return;
30	}
31	atm_force_charge(sigd, skb->truesize);
32	skb_queue_tail(&sk_atm(sigd)->sk_receive_queue, skb);
33	sk_atm(sigd)->sk_data_ready(sk_atm(sigd));
34}
35
36static void modify_qos(struct atm_vcc *vcc, struct atmsvc_msg *msg)
37{
38	struct sk_buff *skb;
39
40	if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
41	    !test_bit(ATM_VF_READY, &vcc->flags))
42		return;
43	msg->type = as_error;
44	if (!vcc->dev->ops->change_qos)
45		msg->reply = -EOPNOTSUPP;
46	else {
47		/* should lock VCC */
48		msg->reply = vcc->dev->ops->change_qos(vcc, &msg->qos,
49						       msg->reply);
50		if (!msg->reply)
51			msg->type = as_okay;
52	}
53	/*
54	 * Should probably just turn around the old skb. But the, the buffer
55	 * space accounting needs to follow the change too. Maybe later.
56	 */
57	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
58		schedule();
59	*(struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg)) = *msg;
60	sigd_put_skb(skb);
61}
62
63static int sigd_send(struct atm_vcc *vcc, struct sk_buff *skb)
64{
65	struct atmsvc_msg *msg;
66	struct atm_vcc *session_vcc;
67	struct sock *sk;
68
69	msg = (struct atmsvc_msg *) skb->data;
70	atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
71	vcc = *(struct atm_vcc **) &msg->vcc;
72	pr_debug("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc);
73	sk = sk_atm(vcc);
74
75	switch (msg->type) {
76	case as_okay:
77		sk->sk_err = -msg->reply;
78		clear_bit(ATM_VF_WAITING, &vcc->flags);
79		if (!*vcc->local.sas_addr.prv && !*vcc->local.sas_addr.pub) {
80			vcc->local.sas_family = AF_ATMSVC;
81			memcpy(vcc->local.sas_addr.prv,
82			       msg->local.sas_addr.prv, ATM_ESA_LEN);
83			memcpy(vcc->local.sas_addr.pub,
84			       msg->local.sas_addr.pub, ATM_E164_LEN + 1);
85		}
86		session_vcc = vcc->session ? vcc->session : vcc;
87		if (session_vcc->vpi || session_vcc->vci)
88			break;
89		session_vcc->itf = msg->pvc.sap_addr.itf;
90		session_vcc->vpi = msg->pvc.sap_addr.vpi;
91		session_vcc->vci = msg->pvc.sap_addr.vci;
92		if (session_vcc->vpi || session_vcc->vci)
93			session_vcc->qos = msg->qos;
94		break;
95	case as_error:
96		clear_bit(ATM_VF_REGIS, &vcc->flags);
97		clear_bit(ATM_VF_READY, &vcc->flags);
98		sk->sk_err = -msg->reply;
99		clear_bit(ATM_VF_WAITING, &vcc->flags);
100		break;
101	case as_indicate:
102		vcc = *(struct atm_vcc **)&msg->listen_vcc;
103		sk = sk_atm(vcc);
104		pr_debug("as_indicate!!!\n");
105		lock_sock(sk);
106		if (sk_acceptq_is_full(sk)) {
107			sigd_enq(NULL, as_reject, vcc, NULL, NULL);
108			dev_kfree_skb(skb);
109			goto as_indicate_complete;
110		}
111		sk->sk_ack_backlog++;
112		skb_queue_tail(&sk->sk_receive_queue, skb);
113		pr_debug("waking sk_sleep(sk) 0x%p\n", sk_sleep(sk));
114		sk->sk_state_change(sk);
115as_indicate_complete:
116		release_sock(sk);
117		return 0;
118	case as_close:
119		set_bit(ATM_VF_RELEASED, &vcc->flags);
120		vcc_release_async(vcc, msg->reply);
121		goto out;
122	case as_modify:
123		modify_qos(vcc, msg);
124		break;
125	case as_addparty:
126	case as_dropparty:
127		sk->sk_err_soft = msg->reply;
128					/* < 0 failure, otherwise ep_ref */
129		clear_bit(ATM_VF_WAITING, &vcc->flags);
130		break;
131	default:
132		pr_alert("bad message type %d\n", (int)msg->type);
133		return -EINVAL;
134	}
135	sk->sk_state_change(sk);
136out:
137	dev_kfree_skb(skb);
138	return 0;
139}
140
141void sigd_enq2(struct atm_vcc *vcc, enum atmsvc_msg_type type,
142	       struct atm_vcc *listen_vcc, const struct sockaddr_atmpvc *pvc,
143	       const struct sockaddr_atmsvc *svc, const struct atm_qos *qos,
144	       int reply)
145{
146	struct sk_buff *skb;
147	struct atmsvc_msg *msg;
148	static unsigned int session = 0;
149
150	pr_debug("%d (0x%p)\n", (int)type, vcc);
151	while (!(skb = alloc_skb(sizeof(struct atmsvc_msg), GFP_KERNEL)))
152		schedule();
153	msg = (struct atmsvc_msg *)skb_put(skb, sizeof(struct atmsvc_msg));
154	memset(msg, 0, sizeof(*msg));
155	msg->type = type;
156	*(struct atm_vcc **) &msg->vcc = vcc;
157	*(struct atm_vcc **) &msg->listen_vcc = listen_vcc;
158	msg->reply = reply;
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;
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);
175	if (vcc)
176		set_bit(ATM_VF_REGIS, &vcc->flags);
177}
178
179void 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)
182{
183	sigd_enq2(vcc, type, listen_vcc, pvc, svc, vcc ? &vcc->qos : NULL, 0);
184	/* other ISP applications may use "reply" */
185}
186
187static void purge_vcc(struct atm_vcc *vcc)
188{
189	if (sk_atm(vcc)->sk_family == PF_ATMSVC &&
190	    !test_bit(ATM_VF_META, &vcc->flags)) {
191		set_bit(ATM_VF_RELEASED, &vcc->flags);
192		clear_bit(ATM_VF_REGIS, &vcc->flags);
193		vcc_release_async(vcc, -EUNATCH);
194	}
195}
196
197static void sigd_close(struct atm_vcc *vcc)
198{
199	struct sock *s;
200	int i;
201
202	pr_debug("\n");
203	sigd = NULL;
204	if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
205		pr_err("closing with requests pending\n");
206	skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
207
208	read_lock(&vcc_sklist_lock);
209	for (i = 0; i < VCC_HTABLE_SIZE; ++i) {
210		struct hlist_head *head = &vcc_hash[i];
211
212		sk_for_each(s, head) {
213			vcc = atm_sk(s);
214
215			purge_vcc(vcc);
216		}
217	}
218	read_unlock(&vcc_sklist_lock);
219}
220
221static struct atmdev_ops sigd_dev_ops = {
222	.close = sigd_close,
223	.send =	sigd_send
224};
225
226static struct atm_dev sigd_dev = {
227	.ops =		&sigd_dev_ops,
228	.type =		"sig",
229	.number =	999,
230	.lock =		__SPIN_LOCK_UNLOCKED(sigd_dev.lock)
231};
232
233int sigd_attach(struct atm_vcc *vcc)
234{
235	if (sigd)
236		return -EADDRINUSE;
237	pr_debug("\n");
238	sigd = vcc;
239	vcc->dev = &sigd_dev;
240	vcc_insert_socket(sk_atm(vcc));
241	set_bit(ATM_VF_META, &vcc->flags);
242	set_bit(ATM_VF_READY, &vcc->flags);
243	return 0;
244}
245