xref: /openbmc/linux/drivers/s390/net/smsgiucv.c (revision 93dc544c)
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 
31 struct smsg_callback {
32 	struct list_head list;
33 	char *prefix;
34 	int len;
35 	void (*callback)(char *from, char *str);
36 };
37 
38 MODULE_AUTHOR
39    ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");
40 MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");
41 
42 static struct iucv_path *smsg_path;
43 
44 static DEFINE_SPINLOCK(smsg_list_lock);
45 static LIST_HEAD(smsg_list);
46 
47 static int smsg_path_pending(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
48 static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
49 
50 static struct iucv_handler smsg_handler = {
51 	.path_pending	 = smsg_path_pending,
52 	.message_pending = smsg_message_pending,
53 };
54 
55 static 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 
64 static 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 
100 int 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 
117 void 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 
135 static struct device_driver smsg_driver = {
136 	.name = "SMSGIUCV",
137 	.bus  = &iucv_bus,
138 };
139 
140 static 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 
147 static int __init smsg_init(void)
148 {
149 	int rc;
150 
151 	if (!MACHINE_IS_VM) {
152 		rc = -EPROTONOSUPPORT;
153 		goto out;
154 	}
155 	rc = driver_register(&smsg_driver);
156 	if (rc != 0)
157 		goto out;
158 	rc = iucv_register(&smsg_handler, 1);
159 	if (rc)
160 		goto out_driver;
161 	smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
162 	if (!smsg_path) {
163 		rc = -ENOMEM;
164 		goto out_register;
165 	}
166 	rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
167 			       NULL, NULL, NULL);
168 	if (rc)
169 		goto out_free;
170 	cpcmd("SET SMSG IUCV", NULL, 0, NULL);
171 	return 0;
172 
173 out_free:
174 	iucv_path_free(smsg_path);
175 out_register:
176 	iucv_unregister(&smsg_handler, 1);
177 out_driver:
178 	driver_unregister(&smsg_driver);
179 out:
180 	return rc;
181 }
182 
183 module_init(smsg_init);
184 module_exit(smsg_exit);
185 MODULE_LICENSE("GPL");
186 
187 EXPORT_SYMBOL(smsg_register_callback);
188 EXPORT_SYMBOL(smsg_unregister_callback);
189