mars/mars_proc.c

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2011-03-02 16:20:36 +00:00
// (c) 2011 Thomas Schoebel-Theuer / 1&1 Internet AG
//#define BRICK_DEBUGGING
//#define MARS_DEBUGGING
//#define IO_DEBUGGING
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sysctl.h>
#include <linux/uaccess.h>
#define _STRATEGY
#include "mars.h"
#include "mars_proc.h"
mars_info_fn mars_info = NULL;
static
int mars_sysctl_handler(ctl_table *table,
int write,
void __user *buffer,
size_t *length,
loff_t *ppos)
{
ssize_t res = 0;
size_t len = *length;
MARS_DBG("write = %d len = %ld pos = %lld\n", write, len, *ppos);
if (!len || *ppos > 0) {
goto done;
}
if (write) {
char tmp[8] = {};
int code = 0;
res = len; // fake consumption of all data
if (len > 7)
len = 7;
if (!copy_from_user(tmp, buffer, len)) {
sscanf(tmp, "%d", &code);
if (code) {
mars_trigger();
}
}
} else {
char *answer = "MARS module not loaded\n";
char *tmp = NULL;
int mylen;
if (mars_info) {
answer = "internal error while determining mars_info\n";
tmp = mars_info();
if (tmp)
answer = tmp;
}
mylen = strlen(answer);
if (len > mylen)
len = mylen;
res = len;
if (copy_to_user(buffer, answer, len)) {
MARS_ERR("write %ld bytes at %p failed\n", len, buffer);
res = -EFAULT;
}
if (tmp)
kfree(tmp);
}
done:
MARS_DBG("res = %ld\n", res);
*length = res;
if (res >= 0) {
*ppos += res;
return 0;
}
return res;
}
static
ctl_table mars_table[] = {
{
.ctl_name = CTL_UNNUMBERED,
.procname = "mars",
.mode = 0600,
.proc_handler = &mars_sysctl_handler,
},
{}
};
////////////////// module init stuff /////////////////////////
static struct ctl_table_header *header = NULL;
static int __init _init_proc(void)
{
MARS_INF("init_proc()\n");
header = register_sysctl_table(mars_table);
return 0;
}
static void __exit _exit_proc(void)
{
MARS_INF("exit_proc()\n");
if (header) {
unregister_sysctl_table(header);
header = NULL;
}
}
MODULE_DESCRIPTION("MARS /proc/ infrastructure");
MODULE_AUTHOR("Thomas Schoebel-Theuer <tst@1und1.de>");
MODULE_LICENSE("GPL");
module_init(_init_proc);
module_exit(_exit_proc);