drivers/s390/net/smsgiucv.c

   1 /*
   2  * IUCV special message driver
   3  *
   4  * Copyright (C) 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 <asm/cpcmd.h>
  27 #include <asm/ebcdic.h>
  28
  29 #include "iucv.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 iucv_handle_t smsg_handle;
  43 static unsigned short smsg_pathid;
  44 static DEFINE_SPINLOCK(smsg_list_lock);
  45 static struct list_head smsg_list = LIST_HEAD_INIT(smsg_list);
  46
  47 static void
  48 smsg_connection_complete(iucv_ConnectionComplete *eib, void *pgm_data)
  49 {
  50 }
  51
  52
  53 static void
  54 smsg_message_pending(iucv_MessagePending *eib, void *pgm_data)
  55 {
  56         struct smsg_callback *cb;
  57         unsigned char *msg;
  58         unsigned char sender[9];
  59         unsigned short len;
  60         int rc, i;
  61
  62         len = eib->ln1msg2.ipbfln1f;
  63         msg = kmalloc(len + 1, GFP_ATOMIC|GFP_DMA);
  64         if (!msg) {
  65                 iucv_reject(eib->ippathid, eib->ipmsgid, eib->iptrgcls);
  66                 return;
  67         }
  68         rc = iucv_receive(eib->ippathid, eib->ipmsgid, eib->iptrgcls,
  69                           msg, len, NULL, NULL, NULL);
  70         if (rc == 0) {
  71                 msg[len] = 0;
  72                 EBCASC(msg, len);
  73                 memcpy(sender, msg, 8);
  74                 sender[8] = 0;
  75                 /* Remove trailing whitespace from the sender name. */
  76                 for (i = 7; i >= 0; i--) {
  77                         if (sender[i] != ' ' && sender[i] != '\t')
  78                                 break;
  79                         sender[i] = 0;
  80                 }
  81                 spin_lock(&smsg_list_lock);
  82                 list_for_each_entry(cb, &smsg_list, list)
  83                         if (strncmp(msg + 8, cb->prefix, cb->len) == 0) {
  84                                 cb->callback(sender, msg + 8);
  85                                 break;
  86                         }
  87                 spin_unlock(&smsg_list_lock);
  88         }
  89         kfree(msg);
  90 }
  91
  92 static iucv_interrupt_ops_t smsg_ops = {
  93         .ConnectionComplete = smsg_connection_complete,
  94         .MessagePending     = smsg_message_pending,
  95 };
  96
  97 static struct device_driver smsg_driver = {
  98         .name = "SMSGIUCV",
  99         .bus  = &iucv_bus,
 100 };
 101
 102 int
 103 smsg_register_callback(char *prefix, void (*callback)(char *from, char *str))
 104 {
 105         struct smsg_callback *cb;
 106
 107         cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);
 108         if (!cb)
 109                 return -ENOMEM;
 110         cb->prefix = prefix;
 111         cb->len = strlen(prefix);
 112         cb->callback = callback;
 113         spin_lock(&smsg_list_lock);
 114         list_add_tail(&cb->list, &smsg_list);
 115         spin_unlock(&smsg_list_lock);
 116         return 0;
 117 }
 118
 119 void
 120 smsg_unregister_callback(char *prefix, void (*callback)(char *from, char *str))
 121 {
 122         struct smsg_callback *cb, *tmp;
 123
 124         spin_lock(&smsg_list_lock);
 125         cb = NULL;
 126         list_for_each_entry(tmp, &smsg_list, list)
 127                 if (tmp->callback == callback &&
 128                     strcmp(tmp->prefix, prefix) == 0) {
 129                         cb = tmp;
 130                         list_del(&cb->list);
 131                         break;
 132                 }
 133         spin_unlock(&smsg_list_lock);
 134         kfree(cb);
 135 }
 136
 137 static void __exit
 138 smsg_exit(void)
 139 {
 140         if (smsg_handle > 0) {
 141                 cpcmd("SET SMSG OFF", NULL, 0, NULL);
 142                 iucv_sever(smsg_pathid, NULL);
 143                 iucv_unregister_program(smsg_handle);
 144                 driver_unregister(&smsg_driver);
 145         }
 146         return;
 147 }
 148
 149 static int __init
 150 smsg_init(void)
 151 {
 152         static unsigned char pgmmask[24] = {
 153                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 154                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 155                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 156         };
 157         int rc;
 158
 159         rc = driver_register(&smsg_driver);
 160         if (rc != 0) {
 161                 printk(KERN_ERR "SMSGIUCV: failed to register driver.\n");
 162                 return rc;
 163         }
 164         smsg_handle = iucv_register_program("SMSGIUCV        ", "*MSG    ",
 165                                             pgmmask, &smsg_ops, NULL);
 166         if (!smsg_handle) {
 167                 printk(KERN_ERR "SMSGIUCV: failed to register to iucv");
 168                 driver_unregister(&smsg_driver);
 169                 return -EIO;    /* better errno ? */
 170         }
 171         rc = iucv_connect (&smsg_pathid, 255, NULL, "*MSG    ", NULL, 0,
 172                            NULL, NULL, smsg_handle, NULL);
 173         if (rc) {
 174                 printk(KERN_ERR "SMSGIUCV: failed to connect to *MSG");
 175                 iucv_unregister_program(smsg_handle);
 176                 driver_unregister(&smsg_driver);
 177                 smsg_handle = NULL;
 178                 return -EIO;
 179         }
 180         cpcmd("SET SMSG IUCV", NULL, 0, NULL);
 181         return 0;
 182 }
 183
 184 module_init(smsg_init);
 185 module_exit(smsg_exit);
 186 MODULE_LICENSE("GPL");
 187
 188 EXPORT_SYMBOL(smsg_register_callback);
 189 EXPORT_SYMBOL(smsg_unregister_callback);