1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * IUCV special message driver
4 *
5 * Copyright IBM Corp. 2003, 2009
6 *
7 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
8 */
9
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/errno.h>
13#include <linux/device.h>
14#include <linux/slab.h>
15#include <net/iucv/iucv.h>
16#include <asm/cpcmd.h>
17#include <asm/ebcdic.h>
18#include "smsgiucv.h"
19
20struct smsg_callback {
21 struct list_head list;
22 const char *prefix;
23 int len;
24 void (*callback)(const char *from, char *str);
25};
26
27MODULE_AUTHOR
28 ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");
29MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");
30
31static struct iucv_path *smsg_path;
32
33static DEFINE_SPINLOCK(smsg_list_lock);
34static LIST_HEAD(smsg_list);
35
36static int smsg_path_pending(struct iucv_path *, u8 *, u8 *);
37static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
38
39static struct iucv_handler smsg_handler = {
40 .path_pending = smsg_path_pending,
41 .message_pending = smsg_message_pending,
42};
43
44static int smsg_path_pending(struct iucv_path *path, u8 *ipvmid, u8 *ipuser)
45{
46 if (strncmp(ipvmid, "*MSG ", 8) != 0)
47 return -EINVAL;
48 /* Path pending from *MSG. */
49 return iucv_path_accept(path, handler: &smsg_handler, userdata: "SMSGIUCV ", NULL);
50}
51
52static void smsg_message_pending(struct iucv_path *path,
53 struct iucv_message *msg)
54{
55 struct smsg_callback *cb;
56 unsigned char *buffer;
57 unsigned char sender[9];
58 int rc, i;
59
60 buffer = kmalloc(size: msg->length + 1, GFP_ATOMIC | GFP_DMA);
61 if (!buffer) {
62 iucv_message_reject(path, msg);
63 return;
64 }
65 rc = iucv_message_receive(path, msg, flags: 0, buffer, size: msg->length, NULL);
66 if (rc == 0) {
67 buffer[msg->length] = 0;
68 EBCASC(buffer, msg->length);
69 memcpy(sender, buffer, 8);
70 sender[8] = 0;
71 /* Remove trailing whitespace from the sender name. */
72 for (i = 7; i >= 0; i--) {
73 if (sender[i] != ' ' && sender[i] != '\t')
74 break;
75 sender[i] = 0;
76 }
77 spin_lock(lock: &smsg_list_lock);
78 list_for_each_entry(cb, &smsg_list, list)
79 if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {
80 cb->callback(sender, buffer + 8);
81 break;
82 }
83 spin_unlock(lock: &smsg_list_lock);
84 }
85 kfree(objp: buffer);
86}
87
88int smsg_register_callback(const char *prefix,
89 void (*callback)(const char *from, char *str))
90{
91 struct smsg_callback *cb;
92
93 cb = kmalloc(size: sizeof(struct smsg_callback), GFP_KERNEL);
94 if (!cb)
95 return -ENOMEM;
96 cb->prefix = prefix;
97 cb->len = strlen(prefix);
98 cb->callback = callback;
99 spin_lock_bh(lock: &smsg_list_lock);
100 list_add_tail(new: &cb->list, head: &smsg_list);
101 spin_unlock_bh(lock: &smsg_list_lock);
102 return 0;
103}
104
105void smsg_unregister_callback(const char *prefix,
106 void (*callback)(const char *from,
107 char *str))
108{
109 struct smsg_callback *cb, *tmp;
110
111 spin_lock_bh(lock: &smsg_list_lock);
112 cb = NULL;
113 list_for_each_entry(tmp, &smsg_list, list)
114 if (tmp->callback == callback &&
115 strcmp(tmp->prefix, prefix) == 0) {
116 cb = tmp;
117 list_del(entry: &cb->list);
118 break;
119 }
120 spin_unlock_bh(lock: &smsg_list_lock);
121 kfree(objp: cb);
122}
123
124static struct device_driver smsg_driver = {
125 .owner = THIS_MODULE,
126 .name = SMSGIUCV_DRV_NAME,
127 .bus = &iucv_bus,
128};
129
130static void __exit smsg_exit(void)
131{
132 cpcmd("SET SMSG OFF", NULL, 0, NULL);
133 iucv_unregister(handle: &smsg_handler, smp: 1);
134 driver_unregister(drv: &smsg_driver);
135}
136
137static int __init smsg_init(void)
138{
139 int rc;
140
141 if (!MACHINE_IS_VM) {
142 rc = -EPROTONOSUPPORT;
143 goto out;
144 }
145 rc = driver_register(drv: &smsg_driver);
146 if (rc != 0)
147 goto out;
148 rc = iucv_register(handler: &smsg_handler, smp: 1);
149 if (rc)
150 goto out_driver;
151 smsg_path = iucv_path_alloc(msglim: 255, flags: 0, GFP_KERNEL);
152 if (!smsg_path) {
153 rc = -ENOMEM;
154 goto out_register;
155 }
156 rc = iucv_path_connect(path: smsg_path, handler: &smsg_handler, userid: "*MSG ",
157 NULL, NULL, NULL);
158 if (rc)
159 goto out_free_path;
160
161 cpcmd("SET SMSG IUCV", NULL, 0, NULL);
162 return 0;
163
164out_free_path:
165 iucv_path_free(path: smsg_path);
166 smsg_path = NULL;
167out_register:
168 iucv_unregister(handle: &smsg_handler, smp: 1);
169out_driver:
170 driver_unregister(drv: &smsg_driver);
171out:
172 return rc;
173}
174
175module_init(smsg_init);
176module_exit(smsg_exit);
177MODULE_LICENSE("GPL");
178
179EXPORT_SYMBOL(smsg_register_callback);
180EXPORT_SYMBOL(smsg_unregister_callback);
181

source code of linux/drivers/s390/net/smsgiucv.c