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 <linux/slab.h>
  28 #include <net/iucv/iucv.h>
  29 #include <asm/cpcmd.h>
  30 #include <asm/ebcdic.h>
  31 #include "smsgiucv.h"
  32
  33 struct smsg_callback {
  34         struct list_head list;
  35         const char *prefix;
  36         int len;
  37         void (*callback)(const char *from, char *str);
  38 };
  39
  40 MODULE_AUTHOR
  41    ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");
  42 MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");
  43
  44 static struct iucv_path *smsg_path;
  45 /* dummy device used as trigger for PM functions */
  46 static struct device *smsg_dev;
  47
  48 static DEFINE_SPINLOCK(smsg_list_lock);
  49 static LIST_HEAD(smsg_list);
  50
  51 static int smsg_path_pending(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
  52 static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
  53
  54 static struct iucv_handler smsg_handler = {
  55         .path_pending    = smsg_path_pending,
  56         .message_pending = smsg_message_pending,
  57 };
  58
  59 static int smsg_path_pending(struct iucv_path *path, u8 ipvmid[8],
  60                              u8 ipuser[16])
  61 {
  62         if (strncmp(ipvmid, "*MSG    ", sizeof(ipvmid)) != 0)
  63                 return -EINVAL;
  64         /* Path pending from *MSG. */
  65         return iucv_path_accept(path, &smsg_handler, "SMSGIUCV        ", NULL);
  66 }
  67
  68 static void smsg_message_pending(struct iucv_path *path,
  69                                  struct iucv_message *msg)
  70 {
  71         struct smsg_callback *cb;
  72         unsigned char *buffer;
  73         unsigned char sender[9];
  74         int rc, i;
  75
  76         buffer = kmalloc(msg->length + 1, GFP_ATOMIC | GFP_DMA);
  77         if (!buffer) {
  78                 iucv_message_reject(path, msg);
  79                 return;
  80         }
  81         rc = iucv_message_receive(path, msg, 0, buffer, msg->length, NULL);
  82         if (rc == 0) {
  83                 buffer[msg->length] = 0;
  84                 EBCASC(buffer, msg->length);
  85                 memcpy(sender, buffer, 8);
  86                 sender[8] = 0;
  87                 /* Remove trailing whitespace from the sender name. */
  88                 for (i = 7; i >= 0; i--) {
  89                         if (sender[i] != ' ' && sender[i] != '\t')
  90                                 break;
  91                         sender[i] = 0;
  92                 }
  93                 spin_lock(&smsg_list_lock);
  94                 list_for_each_entry(cb, &smsg_list, list)
  95                         if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {
  96                                 cb->callback(sender, buffer + 8);
  97                                 break;
  98                         }
  99                 spin_unlock(&smsg_list_lock);
 100         }
 101         kfree(buffer);
 102 }
 103
 104 int smsg_register_callback(const char *prefix,
 105                            void (*callback)(const char *from, char *str))
 106 {
 107         struct smsg_callback *cb;
 108
 109         cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
 110         if (!cb)
 111                 return -ENOMEM;
 112         cb->prefix = prefix;
 113         cb->len = strlen(prefix);
 114         cb->callback = callback;
 115         spin_lock_bh(&smsg_list_lock);
 116         list_add_tail(&cb->list, &smsg_list);
 117         spin_unlock_bh(&smsg_list_lock);
 118         return 0;
 119 }
 120
 121 void smsg_unregister_callback(const char *prefix,
 122                               void (*callback)(const char *from,
 123                                                char *str))
 124 {
 125         struct smsg_callback *cb, *tmp;
 126
 127         spin_lock_bh(&smsg_list_lock);
 128         cb = NULL;
 129         list_for_each_entry(tmp, &smsg_list, list)
 130                 if (tmp->callback == callback &&
 131                     strcmp(tmp->prefix, prefix) == 0) {
 132                         cb = tmp;
 133                         list_del(&cb->list);
 134                         break;
 135                 }
 136         spin_unlock_bh(&smsg_list_lock);
 137         kfree(cb);
 138 }
 139
 140 static int smsg_pm_freeze(struct device *dev)
 141 {
 142 #ifdef CONFIG_PM_DEBUG
 143         printk(KERN_WARNING "smsg_pm_freeze\n");
 144 #endif
 145         if (smsg_path)
 146                 iucv_path_sever(smsg_path, NULL);
 147         return 0;
 148 }
 149
 150 static int smsg_pm_restore_thaw(struct device *dev)
 151 {
 152         int rc;
 153
 154 #ifdef CONFIG_PM_DEBUG
 155         printk(KERN_WARNING "smsg_pm_restore_thaw\n");
 156 #endif
 157         if (smsg_path) {
 158                 memset(smsg_path, 0, sizeof(*smsg_path));
 159                 smsg_path->msglim = 255;
 160                 smsg_path->flags = 0;
 161                 rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 162                                        NULL, NULL, NULL);
 163 #ifdef CONFIG_PM_DEBUG
 164                 if (rc)
 165                         printk(KERN_ERR
 166                                "iucv_path_connect returned with rc %i\n", rc);
 167 #endif
 168                 cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 169         }
 170         return 0;
 171 }
 172
 173 static const struct dev_pm_ops smsg_pm_ops = {
 174         .freeze = smsg_pm_freeze,
 175         .thaw = smsg_pm_restore_thaw,
 176         .restore = smsg_pm_restore_thaw,
 177 };
 178
 179 static struct device_driver smsg_driver = {
 180         .owner = THIS_MODULE,
 181         .name = SMSGIUCV_DRV_NAME,
 182         .bus  = &iucv_bus,
 183         .pm = &smsg_pm_ops,
 184 };
 185
 186 static void __exit smsg_exit(void)
 187 {
 188         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 189         device_unregister(smsg_dev);
 190         iucv_unregister(&smsg_handler, 1);
 191         driver_unregister(&smsg_driver);
 192 }
 193
 194 static int __init smsg_init(void)
 195 {
 196         int rc;
 197
 198         if (!MACHINE_IS_VM) {
 199                 rc = -EPROTONOSUPPORT;
 200                 goto out;
 201         }
 202         rc = driver_register(&smsg_driver);
 203         if (rc != 0)
 204                 goto out;
 205         rc = iucv_register(&smsg_handler, 1);
 206         if (rc)
 207                 goto out_driver;
 208         smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
 209         if (!smsg_path) {
 210                 rc = -ENOMEM;
 211                 goto out_register;
 212         }
 213         rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 214                                NULL, NULL, NULL);
 215         if (rc)
 216                 goto out_free_path;
 217         smsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 218         if (!smsg_dev) {
 219                 rc = -ENOMEM;
 220                 goto out_free_path;
 221         }
 222         dev_set_name(smsg_dev, "smsg_iucv");
 223         smsg_dev->bus = &iucv_bus;
 224         smsg_dev->parent = iucv_root;
 225         smsg_dev->release = (void (*)(struct device *))kfree;
 226         smsg_dev->driver = &smsg_driver;
 227         rc = device_register(smsg_dev);
 228         if (rc)
 229                 goto out_put;
 230
 231         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 232         return 0;
 233
 234 out_put:
 235         put_device(smsg_dev);
 236 out_free_path:
 237         iucv_path_free(smsg_path);
 238         smsg_path = NULL;
 239 out_register:
 240         iucv_unregister(&smsg_handler, 1);
 241 out_driver:
 242         driver_unregister(&smsg_driver);
 243 out:
 244         return rc;
 245 }
 246
 247 module_init(smsg_init);
 248 module_exit(smsg_exit);
 249 MODULE_LICENSE("GPL");
 250
 251 EXPORT_SYMBOL(smsg_register_callback);
 252 EXPORT_SYMBOL(smsg_unregister_callback);