1/*
2 * IUCV special message driver
3 *
4 * Copyright 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/errno.h>
25#include <linux/device.h>
26#include <net/iucv/iucv.h>
27#include <asm/cpcmd.h>
28#include <asm/ebcdic.h>
29#include "smsgiucv.h"
30
31struct smsg_callback {
32	struct list_head list;
33	char *prefix;
34	int len;
35	void (*callback)(char *from, char *str);
36};
37
38MODULE_AUTHOR
39   ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");
40MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");
41
42static struct iucv_path *smsg_path;
43
44static DEFINE_SPINLOCK(smsg_list_lock);
45static struct list_head smsg_list = LIST_HEAD_INIT(smsg_list);
46
47static int smsg_path_pending(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
48static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
49
50static struct iucv_handler smsg_handler = {
51	.path_pending	 = smsg_path_pending,
52	.message_pending = smsg_message_pending,
53};
54
55static int smsg_path_pending(struct iucv_path *path, u8 ipvmid[8],
56			     u8 ipuser[16])
57{
58	if (strncmp(ipvmid, "*MSG    ", sizeof(ipvmid)) != 0)
59		return -EINVAL;
60	/* Path pending from *MSG. */
61	return iucv_path_accept(path, &smsg_handler, "SMSGIUCV        ", NULL);
62}
63
64static void smsg_message_pending(struct iucv_path *path,
65				 struct iucv_message *msg)
66{
67	struct smsg_callback *cb;
68	unsigned char *buffer;
69	unsigned char sender[9];
70	int rc, i;
71
72	buffer = kmalloc(msg->length + 1, GFP_ATOMIC | GFP_DMA);
73	if (!buffer) {
74		iucv_message_reject(path, msg);
75		return;
76	}
77	rc = iucv_message_receive(path, msg, 0, buffer, msg->length, NULL);
78	if (rc == 0) {
79		buffer[msg->length] = 0;
80		EBCASC(buffer, msg->length);
81		memcpy(sender, buffer, 8);
82		sender[8] = 0;
83		/* Remove trailing whitespace from the sender name. */
84		for (i = 7; i >= 0; i--) {
85			if (sender[i] != ' ' && sender[i] != '\t')
86				break;
87			sender[i] = 0;
88		}
89		spin_lock(&smsg_list_lock);
90		list_for_each_entry(cb, &smsg_list, list)
91			if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {
92				cb->callback(sender, buffer + 8);
93				break;
94			}
95		spin_unlock(&smsg_list_lock);
96	}
97	kfree(buffer);
98}
99
100int smsg_register_callback(char *prefix,
101			   void (*callback)(char *from, char *str))
102{
103	struct smsg_callback *cb;
104
105	cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
106	if (!cb)
107		return -ENOMEM;
108	cb->prefix = prefix;
109	cb->len = strlen(prefix);
110	cb->callback = callback;
111	spin_lock_bh(&smsg_list_lock);
112	list_add_tail(&cb->list, &smsg_list);
113	spin_unlock_bh(&smsg_list_lock);
114	return 0;
115}
116
117void smsg_unregister_callback(char *prefix,
118			      void (*callback)(char *from, char *str))
119{
120	struct smsg_callback *cb, *tmp;
121
122	spin_lock_bh(&smsg_list_lock);
123	cb = NULL;
124	list_for_each_entry(tmp, &smsg_list, list)
125		if (tmp->callback == callback &&
126		    strcmp(tmp->prefix, prefix) == 0) {
127			cb = tmp;
128			list_del(&cb->list);
129			break;
130		}
131	spin_unlock_bh(&smsg_list_lock);
132	kfree(cb);
133}
134
135static struct device_driver smsg_driver = {
136	.name = "SMSGIUCV",
137	.bus  = &iucv_bus,
138};
139
140static void __exit smsg_exit(void)
141{
142	cpcmd("SET SMSG IUCV", NULL, 0, NULL);
143	iucv_unregister(&smsg_handler, 1);
144	driver_unregister(&smsg_driver);
145}
146
147static int __init smsg_init(void)
148{
149	int rc;
150
151	rc = driver_register(&smsg_driver);
152	if (rc != 0)
153		goto out;
154	rc = iucv_register(&smsg_handler, 1);
155	if (rc) {
156		printk(KERN_ERR "SMSGIUCV: failed to register to iucv");
157		rc = -EIO;	/* better errno ? */
158		goto out_driver;
159	}
160	smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
161	if (!smsg_path) {
162		rc = -ENOMEM;
163		goto out_register;
164	}
165	rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
166			       NULL, NULL, NULL);
167	if (rc) {
168		printk(KERN_ERR "SMSGIUCV: failed to connect to *MSG");
169		rc = -EIO;	/* better errno ? */
170		goto out_free;
171	}
172	cpcmd("SET SMSG IUCV", NULL, 0, NULL);
173	return 0;
174
175out_free:
176	iucv_path_free(smsg_path);
177out_register:
178	iucv_unregister(&smsg_handler, 1);
179out_driver:
180	driver_unregister(&smsg_driver);
181out:
182	return rc;
183}
184
185module_init(smsg_init);
186module_exit(smsg_exit);
187MODULE_LICENSE("GPL");
188
189EXPORT_SYMBOL(smsg_register_callback);
190EXPORT_SYMBOL(smsg_unregister_callback);
191