drivers/s390/net/smsgiucv.c

   1 /*
   2  * IUCV special message driver
   3  *
   4  * Copyright 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
   5  * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2, or (at your option)
  10  * any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <linux/errno.h>
  25 #include <linux/device.h>
  26 #include <net/iucv/iucv.h>
  27 #include <asm/cpcmd.h>
  28 #include <asm/ebcdic.h>
  29 #include "smsgiucv.h"
  30
  31 struct smsg_callback {
  32         struct list_head list;
  33         char *prefix;
  34         int len;
  35         void (*callback)(char *from, char *str);
  36 };
  37
  38 MODULE_AUTHOR
  39    ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");
  40 MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");
  41
  42 static struct iucv_path *smsg_path;
  43
  44 static DEFINE_SPINLOCK(smsg_list_lock);
  45 static struct list_head smsg_list = LIST_HEAD_INIT(smsg_list);
  46
  47 static int smsg_path_pending(struct iucv_path *, u8 ipvmid[8], u8 ipuser[16]);
  48 static void smsg_message_pending(struct iucv_path *, struct iucv_message *);
  49
  50 static struct iucv_handler smsg_handler = {
  51         .path_pending    = smsg_path_pending,
  52         .message_pending = smsg_message_pending,
  53 };
  54
  55 static int smsg_path_pending(struct iucv_path *path, u8 ipvmid[8],
  56                              u8 ipuser[16])
  57 {
  58         if (strncmp(ipvmid, "*MSG    ", sizeof(ipvmid)) != 0)
  59                 return -EINVAL;
  60         /* Path pending from *MSG. */
  61         return iucv_path_accept(path, &smsg_handler, "SMSGIUCV        ", NULL);
  62 }
  63
  64 static void smsg_message_pending(struct iucv_path *path,
  65                                  struct iucv_message *msg)
  66 {
  67         struct smsg_callback *cb;
  68         unsigned char *buffer;
  69         unsigned char sender[9];
  70         int rc, i;
  71
  72         buffer = kmalloc(msg->length + 1, GFP_ATOMIC | GFP_DMA);
  73         if (!buffer) {
  74                 iucv_message_reject(path, msg);
  75                 return;
  76         }
  77         rc = iucv_message_receive(path, msg, 0, buffer, msg->length, NULL);
  78         if (rc == 0) {
  79                 buffer[msg->length] = 0;
  80                 EBCASC(buffer, msg->length);
  81                 memcpy(sender, buffer, 8);
  82                 sender[8] = 0;
  83                 /* Remove trailing whitespace from the sender name. */
  84                 for (i = 7; i >= 0; i--) {
  85                         if (sender[i] != ' ' && sender[i] != '\t')
  86                                 break;
  87                         sender[i] = 0;
  88                 }
  89                 spin_lock(&smsg_list_lock);
  90                 list_for_each_entry(cb, &smsg_list, list)
  91                         if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {
  92                                 cb->callback(sender, buffer + 8);
  93                                 break;
  94                         }
  95                 spin_unlock(&smsg_list_lock);
  96         }
  97         kfree(buffer);
  98 }
  99
 100 int smsg_register_callback(char *prefix,
 101                            void (*callback)(char *from, char *str))
 102 {
 103         struct smsg_callback *cb;
 104
 105         cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
 106         if (!cb)
 107                 return -ENOMEM;
 108         cb->prefix = prefix;
 109         cb->len = strlen(prefix);
 110         cb->callback = callback;
 111         spin_lock_bh(&smsg_list_lock);
 112         list_add_tail(&cb->list, &smsg_list);
 113         spin_unlock_bh(&smsg_list_lock);
 114         return 0;
 115 }
 116
 117 void smsg_unregister_callback(char *prefix,
 118                               void (*callback)(char *from, char *str))
 119 {
 120         struct smsg_callback *cb, *tmp;
 121
 122         spin_lock_bh(&smsg_list_lock);
 123         cb = NULL;
 124         list_for_each_entry(tmp, &smsg_list, list)
 125                 if (tmp->callback == callback &&
 126                     strcmp(tmp->prefix, prefix) == 0) {
 127                         cb = tmp;
 128                         list_del(&cb->list);
 129                         break;
 130                 }
 131         spin_unlock_bh(&smsg_list_lock);
 132         kfree(cb);
 133 }
 134
 135 static struct device_driver smsg_driver = {
 136         .name = "SMSGIUCV",
 137         .bus  = &iucv_bus,
 138 };
 139
 140 static void __exit smsg_exit(void)
 141 {
 142         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 143         iucv_unregister(&smsg_handler, 1);
 144         driver_unregister(&smsg_driver);
 145 }
 146
 147 static int __init smsg_init(void)
 148 {
 149         int rc;
 150
 151         if (!MACHINE_IS_VM) {
 152                 rc = -EPROTONOSUPPORT;
 153                 goto out;
 154         }
 155         rc = driver_register(&smsg_driver);
 156         if (rc != 0)
 157                 goto out;
 158         rc = iucv_register(&smsg_handler, 1);
 159         if (rc) {
 160                 printk(KERN_ERR "SMSGIUCV: failed to register to iucv");
 161                 rc = -EIO;      /* better errno ? */
 162                 goto out_driver;
 163         }
 164         smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);
 165         if (!smsg_path) {
 166                 rc = -ENOMEM;
 167                 goto out_register;
 168         }
 169         rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG    ",
 170                                NULL, NULL, NULL);
 171         if (rc) {
 172                 printk(KERN_ERR "SMSGIUCV: failed to connect to *MSG");
 173                 rc = -EIO;      /* better errno ? */
 174                 goto out_free;
 175         }
 176         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 177         return 0;
 178
 179 out_free:
 180         iucv_path_free(smsg_path);
 181 out_register:
 182         iucv_unregister(&smsg_handler, 1);
 183 out_driver:
 184         driver_unregister(&smsg_driver);
 185 out:
 186         return rc;
 187 }
 188
 189 module_init(smsg_init);
 190 module_exit(smsg_exit);
 191 MODULE_LICENSE("GPL");
 192
 193 EXPORT_SYMBOL(smsg_register_callback);
 194 EXPORT_SYMBOL(smsg_unregister_callback);