181 lines · c
1// SPDX-License-Identifier: GPL-2.0+2/*3 * IUCV special message driver4 *5 * Copyright IBM Corp. 2003, 20096 *7 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)8 */9 10#include <linux/module.h>11#include <linux/init.h>12#include <linux/errno.h>13#include <linux/device.h>14#include <linux/slab.h>15#include <net/iucv/iucv.h>16#include <asm/cpcmd.h>17#include <asm/ebcdic.h>18#include "smsgiucv.h"19 20struct smsg_callback {21 struct list_head list;22 const char *prefix;23 int len;24 void (*callback)(const char *from, char *str);25};26 27MODULE_AUTHOR28 ("(C) 2003 IBM Corporation by Martin Schwidefsky (schwidefsky@de.ibm.com)");29MODULE_DESCRIPTION ("Linux for S/390 IUCV special message driver");30 31static struct iucv_path *smsg_path;32 33static DEFINE_SPINLOCK(smsg_list_lock);34static LIST_HEAD(smsg_list);35 36static int smsg_path_pending(struct iucv_path *, u8 *, u8 *);37static void smsg_message_pending(struct iucv_path *, struct iucv_message *);38 39static struct iucv_handler smsg_handler = {40 .path_pending = smsg_path_pending,41 .message_pending = smsg_message_pending,42};43 44static int smsg_path_pending(struct iucv_path *path, u8 *ipvmid, u8 *ipuser)45{46 if (strncmp(ipvmid, "*MSG ", 8) != 0)47 return -EINVAL;48 /* Path pending from *MSG. */49 return iucv_path_accept(path, &smsg_handler, "SMSGIUCV ", NULL);50}51 52static void smsg_message_pending(struct iucv_path *path,53 struct iucv_message *msg)54{55 struct smsg_callback *cb;56 unsigned char *buffer;57 unsigned char sender[9];58 int rc, i;59 60 buffer = kmalloc(msg->length + 1, GFP_ATOMIC | GFP_DMA);61 if (!buffer) {62 iucv_message_reject(path, msg);63 return;64 }65 rc = iucv_message_receive(path, msg, 0, buffer, msg->length, NULL);66 if (rc == 0) {67 buffer[msg->length] = 0;68 EBCASC(buffer, msg->length);69 memcpy(sender, buffer, 8);70 sender[8] = 0;71 /* Remove trailing whitespace from the sender name. */72 for (i = 7; i >= 0; i--) {73 if (sender[i] != ' ' && sender[i] != '\t')74 break;75 sender[i] = 0;76 }77 spin_lock(&smsg_list_lock);78 list_for_each_entry(cb, &smsg_list, list)79 if (strncmp(buffer + 8, cb->prefix, cb->len) == 0) {80 cb->callback(sender, buffer + 8);81 break;82 }83 spin_unlock(&smsg_list_lock);84 }85 kfree(buffer);86}87 88int smsg_register_callback(const char *prefix,89 void (*callback)(const char *from, char *str))90{91 struct smsg_callback *cb;92 93 cb = kmalloc(sizeof(struct smsg_callback), GFP_KERNEL);94 if (!cb)95 return -ENOMEM;96 cb->prefix = prefix;97 cb->len = strlen(prefix);98 cb->callback = callback;99 spin_lock_bh(&smsg_list_lock);100 list_add_tail(&cb->list, &smsg_list);101 spin_unlock_bh(&smsg_list_lock);102 return 0;103}104 105void smsg_unregister_callback(const char *prefix,106 void (*callback)(const char *from,107 char *str))108{109 struct smsg_callback *cb, *tmp;110 111 spin_lock_bh(&smsg_list_lock);112 cb = NULL;113 list_for_each_entry(tmp, &smsg_list, list)114 if (tmp->callback == callback &&115 strcmp(tmp->prefix, prefix) == 0) {116 cb = tmp;117 list_del(&cb->list);118 break;119 }120 spin_unlock_bh(&smsg_list_lock);121 kfree(cb);122}123 124static struct device_driver smsg_driver = {125 .owner = THIS_MODULE,126 .name = SMSGIUCV_DRV_NAME,127 .bus = &iucv_bus,128};129 130static void __exit smsg_exit(void)131{132 cpcmd("SET SMSG OFF", NULL, 0, NULL);133 iucv_unregister(&smsg_handler, 1);134 driver_unregister(&smsg_driver);135}136 137static int __init smsg_init(void)138{139 int rc;140 141 if (!MACHINE_IS_VM) {142 rc = -EPROTONOSUPPORT;143 goto out;144 }145 rc = driver_register(&smsg_driver);146 if (rc != 0)147 goto out;148 rc = iucv_register(&smsg_handler, 1);149 if (rc)150 goto out_driver;151 smsg_path = iucv_path_alloc(255, 0, GFP_KERNEL);152 if (!smsg_path) {153 rc = -ENOMEM;154 goto out_register;155 }156 rc = iucv_path_connect(smsg_path, &smsg_handler, "*MSG ",157 NULL, NULL, NULL);158 if (rc)159 goto out_free_path;160 161 cpcmd("SET SMSG IUCV", NULL, 0, NULL);162 return 0;163 164out_free_path:165 iucv_path_free(smsg_path);166 smsg_path = NULL;167out_register:168 iucv_unregister(&smsg_handler, 1);169out_driver:170 driver_unregister(&smsg_driver);171out:172 return rc;173}174 175module_init(smsg_init);176module_exit(smsg_exit);177MODULE_LICENSE("GPL");178 179EXPORT_SYMBOL(smsg_register_callback);180EXPORT_SYMBOL(smsg_unregister_callback);181