drivers/s390/net/smsgiucv.c

   1 /*
   2  * IUCV special message driver
   3  *
   4  * Copyright IBM Corp. 2003, 2009
   5  *
   6  * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/errno.h>
  26 #include <linux/device.h>
  27 #include <net/iucv/iucv.h>
  28 #include <asm/cpcmd.h>
  29 #include <asm/ebcdic.h>
  30 #include "smsgiucv.h"
  31
  32 struct smsg_callback {
  33         struct list_head list;
  34         const char *prefix;
  35         int len;
  36         void (*callback)(const char *from, char *str);
  37 };
  38
  39 MODULE_AUTHOR
  40    ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");
  41 MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");
  42
  43 static struct iucv_path *smsg_path;
  44 /* dummy device used as trigger for PM functions */
  45 static struct device *smsg_dev;
  46
  47 static DEFINE_SPINLOCK(smsg_list_lock);
  48 static LIST_HEAD(smsg_list);
  49
  50 static int smsg_path_pending(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
  51 static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
  52
  53 static struct iucv_handler smsg_handler = {
  54         .path_pending    = smsg_path_pending,
  55         .message_pending = smsg_message_pending,
  56 };
  57
  58 static int smsg_path_pending(struct iucv_path *path, u8 ipvmid[8],
  59                              u8 ipuser[16])
  60 {
  61         if (strncmp(ipvmid, "*MSG    ", sizeof(ipvmid)) != 0)
  62                 return -EINVAL;
  63         /* Path pending from *MSG. */
  64         return iucv_path_accept(path, &smsg_handler, "SMSGIUCV        ", NULL);
  65 }
  66
  67 static void smsg_message_pending(struct iucv_path *path,
  68                                  struct iucv_message *msg)
  69 {
  70         struct smsg_callback *cb;
  71         unsigned char *buffer;
  72         unsigned char sender[9];
  73         int rc, i;
  74
  75         buffer = kmalloc(msg->length + 1, GFP_ATOMIC | GFP_DMA);
  76         if (!buffer) {
  77                 iucv_message_reject(path, msg);
  78                 return;
  79         }
  80         rc = iucv_message_receive(path, msg, 0, buffer, msg->length, NULL);
  81         if (rc == 0) {
  82                 buffer[msg->length] = 0;
  83                 EBCASC(buffer, msg->length);
  84                 memcpy(sender, buffer, 8);
  85                 sender[8] = 0;
  86                 /* Remove trailing whitespace from the sender name. */
  87                 for (i = 7; i >= 0; i--) {
  88                         if (sender[i] != ' ' && sender[i] != '\t')
  89                                 break;
  90                         sender[i] = 0;
  91                 }
  92                 spin_lock(&smsg_list_lock);
  93                 list_for_each_entry(cb, &smsg_list, list)
  94                         if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {
  95                                 cb->callback(sender, buffer + 8);
  96                                 break;
  97                         }
  98                 spin_unlock(&smsg_list_lock);
  99         }
 100         kfree(buffer);
 101 }
 102
 103 int smsg_register_callback(const char *prefix,
 104                            void (*callback)(const char *from, char *str))
 105 {
 106         struct smsg_callback *cb;
 107
 108         cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
 109         if (!cb)
 110                 return -ENOMEM;
 111         cb->prefix = prefix;
 112         cb->len = strlen(prefix);
 113         cb->callback = callback;
 114         spin_lock_bh(&smsg_list_lock);
 115         list_add_tail(&cb->list, &smsg_list);
 116         spin_unlock_bh(&smsg_list_lock);
 117         return 0;
 118 }
 119
 120 void smsg_unregister_callback(const char *prefix,
 121                               void (*callback)(const char *from,
 122                                                char *str))
 123 {
 124         struct smsg_callback *cb, *tmp;
 125
 126         spin_lock_bh(&smsg_list_lock);
 127         cb = NULL;
 128         list_for_each_entry(tmp, &smsg_list, list)
 129                 if (tmp->callback == callback &&
 130                     strcmp(tmp->prefix, prefix) == 0) {
 131                         cb = tmp;
 132                         list_del(&cb->list);
 133                         break;
 134                 }
 135         spin_unlock_bh(&smsg_list_lock);
 136         kfree(cb);
 137 }
 138
 139 static int smsg_pm_freeze(struct device *dev)
 140 {
 141 #ifdef CONFIG_PM_DEBUG
 142         printk(KERN_WARNING "smsg_pm_freeze\n");
 143 #endif
 144         if (smsg_path)
 145                 iucv_path_sever(smsg_path, NULL);
 146         return 0;
 147 }
 148
 149 static int smsg_pm_restore_thaw(struct device *dev)
 150 {
 151         int rc;
 152
 153 #ifdef CONFIG_PM_DEBUG
 154         printk(KERN_WARNING "smsg_pm_restore_thaw\n");
 155 #endif
 156         if (smsg_path) {
 157                 memset(smsg_path, 0, sizeof(*smsg_path));
 158                 smsg_path->msglim = 255;
 159                 smsg_path->flags = 0;
 160                 rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 161                                        NULL, NULL, NULL);
 162 #ifdef CONFIG_PM_DEBUG
 163                 if (rc)
 164                         printk(KERN_ERR
 165                                "iucv_path_connect returned with rc %i\n", rc);
 166 #endif
 167                 cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 168         }
 169         return 0;
 170 }
 171
 172 static const struct dev_pm_ops smsg_pm_ops = {
 173         .freeze = smsg_pm_freeze,
 174         .thaw = smsg_pm_restore_thaw,
 175         .restore = smsg_pm_restore_thaw,
 176 };
 177
 178 static struct device_driver smsg_driver = {
 179         .owner = THIS_MODULE,
 180         .name = SMSGIUCV_DRV_NAME,
 181         .bus  = &iucv_bus,
 182         .pm = &smsg_pm_ops,
 183 };
 184
 185 static void __exit smsg_exit(void)
 186 {
 187         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 188         device_unregister(smsg_dev);
 189         iucv_unregister(&smsg_handler, 1);
 190         driver_unregister(&smsg_driver);
 191 }
 192
 193 static int __init smsg_init(void)
 194 {
 195         int rc;
 196
 197         if (!MACHINE_IS_VM) {
 198                 rc = -EPROTONOSUPPORT;
 199                 goto out;
 200         }
 201         rc = driver_register(&smsg_driver);
 202         if (rc != 0)
 203                 goto out;
 204         rc = iucv_register(&smsg_handler, 1);
 205         if (rc)
 206                 goto out_driver;
 207         smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
 208         if (!smsg_path) {
 209                 rc = -ENOMEM;
 210                 goto out_register;
 211         }
 212         rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 213                                NULL, NULL, NULL);
 214         if (rc)
 215                 goto out_free_path;
 216         smsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 217         if (!smsg_dev) {
 218                 rc = -ENOMEM;
 219                 goto out_free_path;
 220         }
 221         dev_set_name(smsg_dev, "smsg_iucv");
 222         smsg_dev->bus = &iucv_bus;
 223         smsg_dev->parent = iucv_root;
 224         smsg_dev->release = (void (*)(struct device *))kfree;
 225         smsg_dev->driver = &smsg_driver;
 226         rc = device_register(smsg_dev);
 227         if (rc)
 228                 goto out_put;
 229
 230         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 231         return 0;
 232
 233 out_put:
 234         put_device(smsg_dev);
 235 out_free_path:
 236         iucv_path_free(smsg_path);
 237         smsg_path = NULL;
 238 out_register:
 239         iucv_unregister(&smsg_handler, 1);
 240 out_driver:
 241         driver_unregister(&smsg_driver);
 242 out:
 243         return rc;
 244 }
 245
 246 module_init(smsg_init);
 247 module_exit(smsg_exit);
 248 MODULE_LICENSE("GPL");
 249
 250 EXPORT_SYMBOL(smsg_register_callback);
 251 EXPORT_SYMBOL(smsg_unregister_callback);