linux/drivers/s390/net/smsgiucv_app.c
Greg Kroah-Hartman ab9953ff0f s390: net: add SPDX identifiers to the remaining files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/s390/net/ files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Cc: Ursula Braun <ubraun@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-24 14:28:43 +01:00

220 lines
5.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Deliver z/VM CP special messages (SMSG) as uevents.
*
* The driver registers for z/VM CP special messages with the
* "APP" prefix. Incoming messages are delivered to user space
* as uevents.
*
* Copyright IBM Corp. 2010
* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
*
*/
#define KMSG_COMPONENT "smsgiucv_app"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <net/iucv/iucv.h>
#include "smsgiucv.h"
/* prefix used for SMSG registration */
#define SMSG_PREFIX "APP"
/* SMSG related uevent environment variables */
#define ENV_SENDER_STR "SMSG_SENDER="
#define ENV_SENDER_LEN (strlen(ENV_SENDER_STR) + 8 + 1)
#define ENV_PREFIX_STR "SMSG_ID="
#define ENV_PREFIX_LEN (strlen(ENV_PREFIX_STR) + \
strlen(SMSG_PREFIX) + 1)
#define ENV_TEXT_STR "SMSG_TEXT="
#define ENV_TEXT_LEN(msg) (strlen(ENV_TEXT_STR) + strlen((msg)) + 1)
/* z/VM user ID which is permitted to send SMSGs
* If the value is undefined or empty (""), special messages are
* accepted from any z/VM user ID. */
static char *sender;
module_param(sender, charp, 0400);
MODULE_PARM_DESC(sender, "z/VM user ID from which CP SMSGs are accepted");
/* SMSG device representation */
static struct device *smsg_app_dev;
/* list element for queuing received messages for delivery */
struct smsg_app_event {
struct list_head list;
char *buf;
char *envp[4];
};
/* queue for outgoing uevents */
static LIST_HEAD(smsg_event_queue);
static DEFINE_SPINLOCK(smsg_event_queue_lock);
static void smsg_app_event_free(struct smsg_app_event *ev)
{
kfree(ev->buf);
kfree(ev);
}
static struct smsg_app_event *smsg_app_event_alloc(const char *from,
const char *msg)
{
struct smsg_app_event *ev;
ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
if (!ev)
return NULL;
ev->buf = kzalloc(ENV_SENDER_LEN + ENV_PREFIX_LEN +
ENV_TEXT_LEN(msg), GFP_ATOMIC);
if (!ev->buf) {
kfree(ev);
return NULL;
}
/* setting up environment pointers into buf */
ev->envp[0] = ev->buf;
ev->envp[1] = ev->envp[0] + ENV_SENDER_LEN;
ev->envp[2] = ev->envp[1] + ENV_PREFIX_LEN;
ev->envp[3] = NULL;
/* setting up environment: sender, prefix name, and message text */
snprintf(ev->envp[0], ENV_SENDER_LEN, ENV_SENDER_STR "%s", from);
snprintf(ev->envp[1], ENV_PREFIX_LEN, ENV_PREFIX_STR "%s", SMSG_PREFIX);
snprintf(ev->envp[2], ENV_TEXT_LEN(msg), ENV_TEXT_STR "%s", msg);
return ev;
}
static void smsg_event_work_fn(struct work_struct *work)
{
LIST_HEAD(event_queue);
struct smsg_app_event *p, *n;
struct device *dev;
dev = get_device(smsg_app_dev);
if (!dev)
return;
spin_lock_bh(&smsg_event_queue_lock);
list_splice_init(&smsg_event_queue, &event_queue);
spin_unlock_bh(&smsg_event_queue_lock);
list_for_each_entry_safe(p, n, &event_queue, list) {
list_del(&p->list);
kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, p->envp);
smsg_app_event_free(p);
}
put_device(dev);
}
static DECLARE_WORK(smsg_event_work, smsg_event_work_fn);
static void smsg_app_callback(const char *from, char *msg)
{
struct smsg_app_event *se;
/* check if the originating z/VM user ID matches
* the configured sender. */
if (sender && strlen(sender) > 0 && strcmp(from, sender) != 0)
return;
/* get start of message text (skip prefix and leading blanks) */
msg += strlen(SMSG_PREFIX);
while (*msg && isspace(*msg))
msg++;
if (*msg == '\0')
return;
/* allocate event list element and its environment */
se = smsg_app_event_alloc(from, msg);
if (!se)
return;
/* queue event and schedule work function */
spin_lock(&smsg_event_queue_lock);
list_add_tail(&se->list, &smsg_event_queue);
spin_unlock(&smsg_event_queue_lock);
schedule_work(&smsg_event_work);
return;
}
static int __init smsgiucv_app_init(void)
{
struct device_driver *smsgiucv_drv;
int rc;
if (!MACHINE_IS_VM)
return -ENODEV;
smsg_app_dev = kzalloc(sizeof(*smsg_app_dev), GFP_KERNEL);
if (!smsg_app_dev)
return -ENOMEM;
smsgiucv_drv = driver_find(SMSGIUCV_DRV_NAME, &iucv_bus);
if (!smsgiucv_drv) {
kfree(smsg_app_dev);
return -ENODEV;
}
rc = dev_set_name(smsg_app_dev, KMSG_COMPONENT);
if (rc) {
kfree(smsg_app_dev);
goto fail;
}
smsg_app_dev->bus = &iucv_bus;
smsg_app_dev->parent = iucv_root;
smsg_app_dev->release = (void (*)(struct device *)) kfree;
smsg_app_dev->driver = smsgiucv_drv;
rc = device_register(smsg_app_dev);
if (rc) {
put_device(smsg_app_dev);
goto fail;
}
/* convert sender to uppercase characters */
if (sender) {
int len = strlen(sender);
while (len--)
sender[len] = toupper(sender[len]);
}
/* register with the smsgiucv device driver */
rc = smsg_register_callback(SMSG_PREFIX, smsg_app_callback);
if (rc) {
device_unregister(smsg_app_dev);
goto fail;
}
rc = 0;
fail:
return rc;
}
module_init(smsgiucv_app_init);
static void __exit smsgiucv_app_exit(void)
{
/* unregister callback */
smsg_unregister_callback(SMSG_PREFIX, smsg_app_callback);
/* cancel pending work and flush any queued event work */
cancel_work_sync(&smsg_event_work);
smsg_event_work_fn(&smsg_event_work);
device_unregister(smsg_app_dev);
}
module_exit(smsgiucv_app_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Deliver z/VM CP SMSG as uevents");
MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>");