133 lines
3.1 KiB
C
133 lines
3.1 KiB
C
/*
|
|
* Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
// Test
|
|
// 1) read of every file in /proc
|
|
// 2) readlink of every symlink in /proc
|
|
// 3) recursively (1) + (2) for every directory in /proc
|
|
// 4) write to /proc/*/clear_refs and /proc/*/task/*/clear_refs
|
|
// 5) write to /proc/sysrq-trigger
|
|
#undef NDEBUG
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <sys/types.h>
|
|
#include <dirent.h>
|
|
#include <stdbool.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
|
|
#include "proc.h"
|
|
|
|
static void f_reg(DIR *d, const char *filename)
|
|
{
|
|
char buf[4096];
|
|
int fd;
|
|
ssize_t rv;
|
|
|
|
/* read from /proc/kmsg can block */
|
|
fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK);
|
|
if (fd == -1)
|
|
return;
|
|
rv = read(fd, buf, sizeof(buf));
|
|
assert((0 <= rv && rv <= sizeof(buf)) || rv == -1);
|
|
close(fd);
|
|
}
|
|
|
|
static void f_reg_write(DIR *d, const char *filename, const char *buf, size_t len)
|
|
{
|
|
int fd;
|
|
ssize_t rv;
|
|
|
|
fd = openat(dirfd(d), filename, O_WRONLY);
|
|
if (fd == -1)
|
|
return;
|
|
rv = write(fd, buf, len);
|
|
assert((0 <= rv && rv <= len) || rv == -1);
|
|
close(fd);
|
|
}
|
|
|
|
static void f_lnk(DIR *d, const char *filename)
|
|
{
|
|
char buf[4096];
|
|
ssize_t rv;
|
|
|
|
rv = readlinkat(dirfd(d), filename, buf, sizeof(buf));
|
|
assert((0 <= rv && rv <= sizeof(buf)) || rv == -1);
|
|
}
|
|
|
|
static void f(DIR *d, unsigned int level)
|
|
{
|
|
struct dirent *de;
|
|
|
|
de = xreaddir(d);
|
|
assert(de->d_type == DT_DIR);
|
|
assert(streq(de->d_name, "."));
|
|
|
|
de = xreaddir(d);
|
|
assert(de->d_type == DT_DIR);
|
|
assert(streq(de->d_name, ".."));
|
|
|
|
while ((de = xreaddir(d))) {
|
|
assert(!streq(de->d_name, "."));
|
|
assert(!streq(de->d_name, ".."));
|
|
|
|
switch (de->d_type) {
|
|
DIR *dd;
|
|
int fd;
|
|
|
|
case DT_REG:
|
|
if (level == 0 && streq(de->d_name, "sysrq-trigger")) {
|
|
f_reg_write(d, de->d_name, "h", 1);
|
|
} else if (level == 1 && streq(de->d_name, "clear_refs")) {
|
|
f_reg_write(d, de->d_name, "1", 1);
|
|
} else if (level == 3 && streq(de->d_name, "clear_refs")) {
|
|
f_reg_write(d, de->d_name, "1", 1);
|
|
} else {
|
|
f_reg(d, de->d_name);
|
|
}
|
|
break;
|
|
case DT_DIR:
|
|
fd = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY);
|
|
if (fd == -1)
|
|
continue;
|
|
dd = fdopendir(fd);
|
|
if (!dd)
|
|
continue;
|
|
f(dd, level + 1);
|
|
closedir(dd);
|
|
break;
|
|
case DT_LNK:
|
|
f_lnk(d, de->d_name);
|
|
break;
|
|
default:
|
|
assert(0);
|
|
}
|
|
}
|
|
}
|
|
|
|
int main(void)
|
|
{
|
|
DIR *d;
|
|
|
|
d = opendir("/proc");
|
|
if (!d)
|
|
return 2;
|
|
f(d, 0);
|
|
return 0;
|
|
}
|