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#define _LARGEFILE64_SOURCE
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <fcntl.h>
#include <limits.h>
#include <errno.h>
#include <stdint.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/syscall.h>
/* Our own declaration taken from the kernel since glibc does not have it... */
struct linux_dirent64 {
uint64_t d_ino;
int64_t d_off;
unsigned short d_reclen;
unsigned char d_type;
char d_name[];
};
#define MIN_NAME_LEN 8
#define MAX_NAME_LEN 70
static DIR *dir;
static int dfd;
static int ignore_error;
struct dir_ops {
loff_t (*getpos)(void);
void (*setpos)(loff_t pos);
void (*getentry)(struct dirent *entry);
};
static off64_t libc_getpos(void)
{
return telldir(dir);
}
static void libc_setpos(off64_t pos)
{
seekdir(dir, pos);
}
static void libc_getentry(struct dirent *entry)
{
struct dirent *ret;
errno = 0;
ret = readdir(dir);
if (!ret) {
if (errno == 0) {
fprintf(stderr, "Unexpected EOF while reading dir.\n");
exit(1);
}
if (ignore_error)
return;
perror("readdir");
exit(1);
}
memcpy(entry, ret, sizeof(struct dirent));
}
static off64_t kernel_getpos(void)
{
return lseek64(dfd, 0, SEEK_CUR);
}
static void kernel_setpos(off64_t pos)
{
lseek64(dfd, pos, SEEK_SET);
}
static void kernel_getentry(struct dirent *entry)
{
char dirbuf[NAME_MAX + 1 + sizeof(struct linux_dirent64)];
struct linux_dirent64 *lentry = (struct linux_dirent64 *)dirbuf;
int ret;
ret = syscall(SYS_getdents64, dfd, lentry, sizeof(dirbuf));
if (ret < 0) {
if (ignore_error)
return;
perror("getdents64");
exit(1);
}
if (ret == 0) {
fprintf(stderr, "Unexpected EOF while reading dir.\n");
exit(1);
}
entry->d_ino = lentry->d_ino;
entry->d_off = lentry->d_off;
entry->d_reclen = lentry->d_reclen;
entry->d_type = lentry->d_type;
strcpy(entry->d_name, lentry->d_name);
}
struct dir_ops libc_ops = {
.getpos = libc_getpos,
.setpos = libc_setpos,
.getentry = libc_getentry,
};
struct dir_ops kernel_ops = {
.getpos = kernel_getpos,
.setpos = kernel_setpos,
.getentry = kernel_getentry,
};
static void create_dir(char *dir, int count)
{
int i, j, len;
char namebuf[MAX_NAME_LEN];
int dfd, fd;
dfd = open(dir, O_RDONLY | O_DIRECTORY);
if (dfd < 0) {
perror("Cannot open dir");
exit(1);
}
for (i = 0; i < count; i++) {
len = random() % (MAX_NAME_LEN - MIN_NAME_LEN) + MIN_NAME_LEN;
for (j = 0; j < len; j++)
namebuf[j] = random() % 26 + 'a';
namebuf[len] = 0;
fd = openat(dfd, namebuf, O_RDWR | O_CREAT | O_EXCL, 0644);
if (fd < 0) {
if (errno == EEXIST) {
/* Try again */
i--;
continue;
}
perror("File creation failed");
exit(1);
}
close(fd);
}
close(dfd);
}
static void test(int count, struct dir_ops *ops)
{
struct dirent *dbuf;
struct dirent entry;
loff_t *pbuf;
loff_t dpos, maxpos = 0;
int i, pos;
dbuf = calloc(count, sizeof(struct dirent));
pbuf = calloc(count, sizeof(loff_t));
if (!dbuf || !pbuf) {
fprintf(stderr, "Out of memory for buffers.\n");
exit(1);
}
for (i = 0; i < count; i++) {
pbuf[i] = ops->getpos();
if (pbuf[i] > maxpos)
maxpos = pbuf[i];
ops->getentry(dbuf + i);
ops->setpos(dbuf[i].d_off);
}
for (i = 0; i < count; i++) {
pos = random() % count;
ops->setpos(pbuf[pos]);
ops->getentry(&entry);
if (dbuf[pos].d_ino != entry.d_ino ||
dbuf[pos].d_type != entry.d_type ||
strcmp(dbuf[pos].d_name, entry.d_name)) {
fprintf(stderr,
"Mismatch in dir entry %u at pos %llu\n", pos,
(unsigned long long)pbuf[pos]);
exit(1);
}
}
puts("Reading valid entries passed.");
ignore_error = 1;
for (i = 0; i < count; i++) {
dpos = random() % maxpos;
ops->setpos(dpos);
/*
* We don't care about the result but the kernel should not
* crash.
*/
ops->getentry(&entry);
}
ignore_error = 0;
puts("Reading random positions passed.");
free(dbuf);
free(pbuf);
}
int main(int argc, char *argv[])
{
int count;
unsigned long seed;
if (argc != 4) {
fprintf(stderr, "Usage: t_seekdir_3 <dir> <count> <seed>\n");
return 1;
}
count = atoi(argv[2]);
seed = atol(argv[3]);
srandom(seed);
create_dir(argv[1], count);
puts("Testing readdir...");
dir = opendir(argv[1]);
if (!dir) {
perror("Cannot open dir");
exit(1);
}
test(count, &libc_ops);
closedir(dir);
dir = NULL;
puts("Testing getdents...");
dfd = open(argv[1], O_DIRECTORY | O_RDONLY);
if (dfd < 0) {
perror("Cannot open dir");
exit(1);
}
test(count, &kernel_ops);
close(dfd);
dfd = 0;
fprintf(stderr, "All tests passed\n");
return 0;
}
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