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/*
* 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 /proc/*/fd lookup.
#undef NDEBUG
#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <limits.h>
#include <sched.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "proc.h"
/* lstat(2) has more "coverage" in case non-symlink pops up somehow. */
static void test_lookup_pass(const char *pathname)
{
struct stat st;
ssize_t rv;
memset(&st, 0, sizeof(struct stat));
rv = lstat(pathname, &st);
assert(rv == 0);
assert(S_ISLNK(st.st_mode));
}
static void test_lookup_fail(const char *pathname)
{
struct stat st;
ssize_t rv;
rv = lstat(pathname, &st);
assert(rv == -1 && errno == ENOENT);
}
static void test_lookup(unsigned int fd)
{
char buf[64];
unsigned int c;
unsigned int u;
int i;
snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd);
test_lookup_pass(buf);
/* leading junk */
for (c = 1; c <= 255; c++) {
if (c == '/')
continue;
snprintf(buf, sizeof(buf), "/proc/self/fd/%c%u", c, fd);
test_lookup_fail(buf);
}
/* trailing junk */
for (c = 1; c <= 255; c++) {
if (c == '/')
continue;
snprintf(buf, sizeof(buf), "/proc/self/fd/%u%c", fd, c);
test_lookup_fail(buf);
}
for (i = INT_MIN; i < INT_MIN + 1024; i++) {
snprintf(buf, sizeof(buf), "/proc/self/fd/%d", i);
test_lookup_fail(buf);
}
for (i = -1024; i < 0; i++) {
snprintf(buf, sizeof(buf), "/proc/self/fd/%d", i);
test_lookup_fail(buf);
}
for (u = INT_MAX - 1024; u <= (unsigned int)INT_MAX + 1024; u++) {
snprintf(buf, sizeof(buf), "/proc/self/fd/%u", u);
test_lookup_fail(buf);
}
for (u = UINT_MAX - 1024; u != 0; u++) {
snprintf(buf, sizeof(buf), "/proc/self/fd/%u", u);
test_lookup_fail(buf);
}
}
int main(void)
{
struct dirent *de;
unsigned int fd, target_fd;
if (unshare(CLONE_FILES) == -1)
return 1;
/* Wipe fdtable. */
do {
DIR *d;
d = opendir("/proc/self/fd");
if (!d)
return 1;
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, ".."));
next:
de = xreaddir(d);
if (de) {
unsigned long long fd_ull;
unsigned int fd;
char *end;
assert(de->d_type == DT_LNK);
fd_ull = xstrtoull(de->d_name, &end);
assert(*end == '\0');
assert(fd_ull == (unsigned int)fd_ull);
fd = fd_ull;
if (fd == dirfd(d))
goto next;
close(fd);
}
closedir(d);
} while (de);
/* Now fdtable is clean. */
fd = open("/", O_PATH|O_DIRECTORY);
assert(fd == 0);
test_lookup(fd);
close(fd);
/* Clean again! */
fd = open("/", O_PATH|O_DIRECTORY);
assert(fd == 0);
/* Default RLIMIT_NOFILE-1 */
target_fd = 1023;
while (target_fd > 0) {
if (dup2(fd, target_fd) == target_fd)
break;
target_fd /= 2;
}
assert(target_fd > 0);
close(fd);
test_lookup(target_fd);
close(target_fd);
return 0;
}
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