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         char *prefix;
  35         int len;
  36         void (*callback)(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(char *prefix,
 104                            void (*callback)(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(char *prefix,
 121                               void (*callback)(char *from, char *str))
 122 {
 123         struct smsg_callback *cb, *tmp;
 124
 125         spin_lock_bh(&smsg_list_lock);
 126         cb = NULL;
 127         list_for_each_entry(tmp, &smsg_list, list)
 128                 if (tmp->callback == callback &&
 129                     strcmp(tmp->prefix, prefix) == 0) {
 130                         cb = tmp;
 131                         list_del(&cb->list);
 132                         break;
 133                 }
 134         spin_unlock_bh(&smsg_list_lock);
 135         kfree(cb);
 136 }
 137
 138 static int smsg_pm_freeze(struct device *dev)
 139 {
 140 #ifdef CONFIG_PM_DEBUG
 141         printk(KERN_WARNING "smsg_pm_freeze\n");
 142 #endif
 143         if (smsg_path)
 144                 iucv_path_sever(smsg_path, NULL);
 145         return 0;
 146 }
 147
 148 static int smsg_pm_restore_thaw(struct device *dev)
 149 {
 150         int rc;
 151
 152 #ifdef CONFIG_PM_DEBUG
 153         printk(KERN_WARNING "smsg_pm_restore_thaw\n");
 154 #endif
 155         if (smsg_path) {
 156                 memset(smsg_path, 0, sizeof(*smsg_path));
 157                 smsg_path->msglim = 255;
 158                 smsg_path->flags = 0;
 159                 rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 160                                        NULL, NULL, NULL);
 161                 printk(KERN_ERR "iucv_path_connect returned with rc %i\n", rc);
 162         }
 163         return 0;
 164 }
 165
 166 static struct dev_pm_ops smsg_pm_ops = {
 167         .freeze = smsg_pm_freeze,
 168         .thaw = smsg_pm_restore_thaw,
 169         .restore = smsg_pm_restore_thaw,
 170 };
 171
 172 static struct device_driver smsg_driver = {
 173         .owner = THIS_MODULE,
 174         .name = "SMSGIUCV",
 175         .bus  = &iucv_bus,
 176         .pm = &smsg_pm_ops,
 177 };
 178
 179 static void __exit smsg_exit(void)
 180 {
 181         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 182         device_unregister(smsg_dev);
 183         iucv_unregister(&smsg_handler, 1);
 184         driver_unregister(&smsg_driver);
 185 }
 186
 187 static int __init smsg_init(void)
 188 {
 189         int rc;
 190
 191         if (!MACHINE_IS_VM) {
 192                 rc = -EPROTONOSUPPORT;
 193                 goto out;
 194         }
 195         rc = driver_register(&smsg_driver);
 196         if (rc != 0)
 197                 goto out;
 198         rc = iucv_register(&smsg_handler, 1);
 199         if (rc)
 200                 goto out_driver;
 201         smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
 202         if (!smsg_path) {
 203                 rc = -ENOMEM;
 204                 goto out_register;
 205         }
 206         rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 207                                NULL, NULL, NULL);
 208         if (rc)
 209                 goto out_free_path;
 210         smsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 211         if (!smsg_dev) {
 212                 rc = -ENOMEM;
 213                 goto out_free_path;
 214         }
 215         dev_set_name(smsg_dev, "smsg_iucv");
 216         smsg_dev->bus = &iucv_bus;
 217         smsg_dev->parent = iucv_root;
 218         smsg_dev->release = (void (*)(struct device *))kfree;
 219         smsg_dev->driver = &smsg_driver;
 220         rc = device_register(smsg_dev);
 221         if (rc)
 222                 goto out_free_dev;
 223
 224         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 225         return 0;
 226
 227 out_free_dev:
 228         kfree(smsg_dev);
 229 out_free_path:
 230         iucv_path_free(smsg_path);
 231         smsg_path = NULL;
 232 out_register:
 233         iucv_unregister(&smsg_handler, 1);
 234 out_driver:
 235         driver_unregister(&smsg_driver);
 236 out:
 237         return rc;
 238 }
 239
 240 module_init(smsg_init);
 241 module_exit(smsg_exit);
 242 MODULE_LICENSE("GPL");
 243
 244 EXPORT_SYMBOL(smsg_register_callback);
 245 EXPORT_SYMBOL(smsg_unregister_callback);