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 static int iucv_path_connected;
  51
  52 static int smsg_path_pending(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
  53 static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
  54
  55 static struct iucv_handler smsg_handler = {
  56         .path_pending    = smsg_path_pending,
  57         .message_pending = smsg_message_pending,
  58 };
  59
  60 static int smsg_path_pending(struct iucv_path *path, u8 ipvmid[8],
  61                              u8 ipuser[16])
  62 {
  63         if (strncmp(ipvmid, "*MSG    ", 8) != 0)
  64                 return -EINVAL;
  65         /* Path pending from *MSG. */
  66         return iucv_path_accept(path, &smsg_handler, "SMSGIUCV        ", NULL);
  67 }
  68
  69 static void smsg_message_pending(struct iucv_path *path,
  70                                  struct iucv_message *msg)
  71 {
  72         struct smsg_callback *cb;
  73         unsigned char *buffer;
  74         unsigned char sender[9];
  75         int rc, i;
  76
  77         buffer = kmalloc(msg->length + 1, GFP_ATOMIC | GFP_DMA);
  78         if (!buffer) {
  79                 iucv_message_reject(path, msg);
  80                 return;
  81         }
  82         rc = iucv_message_receive(path, msg, 0, buffer, msg->length, NULL);
  83         if (rc == 0) {
  84                 buffer[msg->length] = 0;
  85                 EBCASC(buffer, msg->length);
  86                 memcpy(sender, buffer, 8);
  87                 sender[8] = 0;
  88                 /* Remove trailing whitespace from the sender name. */
  89                 for (i = 7; i >= 0; i--) {
  90                         if (sender[i] != ' ' && sender[i] != '\t')
  91                                 break;
  92                         sender[i] = 0;
  93                 }
  94                 spin_lock(&smsg_list_lock);
  95                 list_for_each_entry(cb, &smsg_list, list)
  96                         if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {
  97                                 cb->callback(sender, buffer + 8);
  98                                 break;
  99                         }
 100                 spin_unlock(&smsg_list_lock);
 101         }
 102         kfree(buffer);
 103 }
 104
 105 int smsg_register_callback(const char *prefix,
 106                            void (*callback)(const char *from, char *str))
 107 {
 108         struct smsg_callback *cb;
 109
 110         cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
 111         if (!cb)
 112                 return -ENOMEM;
 113         cb->prefix = prefix;
 114         cb->len = strlen(prefix);
 115         cb->callback = callback;
 116         spin_lock_bh(&smsg_list_lock);
 117         list_add_tail(&cb->list, &smsg_list);
 118         spin_unlock_bh(&smsg_list_lock);
 119         return 0;
 120 }
 121
 122 void smsg_unregister_callback(const char *prefix,
 123                               void (*callback)(const char *from,
 124                                                char *str))
 125 {
 126         struct smsg_callback *cb, *tmp;
 127
 128         spin_lock_bh(&smsg_list_lock);
 129         cb = NULL;
 130         list_for_each_entry(tmp, &smsg_list, list)
 131                 if (tmp->callback == callback &&
 132                     strcmp(tmp->prefix, prefix) == 0) {
 133                         cb = tmp;
 134                         list_del(&cb->list);
 135                         break;
 136                 }
 137         spin_unlock_bh(&smsg_list_lock);
 138         kfree(cb);
 139 }
 140
 141 static int smsg_pm_freeze(struct device *dev)
 142 {
 143 #ifdef CONFIG_PM_DEBUG
 144         printk(KERN_WARNING "smsg_pm_freeze\n");
 145 #endif
 146         if (smsg_path && iucv_path_connected) {
 147                 iucv_path_sever(smsg_path, NULL);
 148                 iucv_path_connected = 0;
 149         }
 150         return 0;
 151 }
 152
 153 static int smsg_pm_restore_thaw(struct device *dev)
 154 {
 155         int rc;
 156
 157 #ifdef CONFIG_PM_DEBUG
 158         printk(KERN_WARNING "smsg_pm_restore_thaw\n");
 159 #endif
 160         if (smsg_path && !iucv_path_connected) {
 161                 memset(smsg_path, 0, sizeof(*smsg_path));
 162                 smsg_path->msglim = 255;
 163                 smsg_path->flags = 0;
 164                 rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 165                                        NULL, NULL, NULL);
 166 #ifdef CONFIG_PM_DEBUG
 167                 if (rc)
 168                         printk(KERN_ERR
 169                                "iucv_path_connect returned with rc %i\n", rc);
 170 #endif
 171                 if (!rc)
 172                         iucv_path_connected = 1;
 173                 cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 174         }
 175         return 0;
 176 }
 177
 178 static const struct dev_pm_ops smsg_pm_ops = {
 179         .freeze = smsg_pm_freeze,
 180         .thaw = smsg_pm_restore_thaw,
 181         .restore = smsg_pm_restore_thaw,
 182 };
 183
 184 static struct device_driver smsg_driver = {
 185         .owner = THIS_MODULE,
 186         .name = SMSGIUCV_DRV_NAME,
 187         .bus  = &iucv_bus,
 188         .pm = &smsg_pm_ops,
 189 };
 190
 191 static void __exit smsg_exit(void)
 192 {
 193         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 194         device_unregister(smsg_dev);
 195         iucv_unregister(&smsg_handler, 1);
 196         driver_unregister(&smsg_driver);
 197 }
 198
 199 static int __init smsg_init(void)
 200 {
 201         int rc;
 202
 203         if (!MACHINE_IS_VM) {
 204                 rc = -EPROTONOSUPPORT;
 205                 goto out;
 206         }
 207         rc = driver_register(&smsg_driver);
 208         if (rc != 0)
 209                 goto out;
 210         rc = iucv_register(&smsg_handler, 1);
 211         if (rc)
 212                 goto out_driver;
 213         smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
 214         if (!smsg_path) {
 215                 rc = -ENOMEM;
 216                 goto out_register;
 217         }
 218         rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 219                                NULL, NULL, NULL);
 220         if (rc)
 221                 goto out_free_path;
 222         else
 223                 iucv_path_connected = 1;
 224         smsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 225         if (!smsg_dev) {
 226                 rc = -ENOMEM;
 227                 goto out_free_path;
 228         }
 229         dev_set_name(smsg_dev, "smsg_iucv");
 230         smsg_dev->bus = &iucv_bus;
 231         smsg_dev->parent = iucv_root;
 232         smsg_dev->release = (void (*)(struct device *))kfree;
 233         smsg_dev->driver = &smsg_driver;
 234         rc = device_register(smsg_dev);
 235         if (rc)
 236                 goto out_put;
 237
 238         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 239         return 0;
 240
 241 out_put:
 242         put_device(smsg_dev);
 243 out_free_path:
 244         iucv_path_free(smsg_path);
 245         smsg_path = NULL;
 246 out_register:
 247         iucv_unregister(&smsg_handler, 1);
 248 out_driver:
 249         driver_unregister(&smsg_driver);
 250 out:
 251         return rc;
 252 }
 253
 254 module_init(smsg_init);
 255 module_exit(smsg_exit);
 256 MODULE_LICENSE("GPL");
 257
 258 EXPORT_SYMBOL(smsg_register_callback);
 259 EXPORT_SYMBOL(smsg_unregister_callback);