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// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <linux/types.h>
#include <sched.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syscall.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/wait.h>
#include <unistd.h>
#include "pidfd.h"
#include "../kselftest.h"
#ifndef PIDFS_IOCTL_MAGIC
#define PIDFS_IOCTL_MAGIC 0xFF
#endif
#ifndef PIDFD_GET_INFO
#define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
#define PIDFD_INFO_CGROUPID (1UL << 0)
struct pidfd_info {
__u64 request_mask;
__u64 cgroupid;
__u32 pid;
__u32 tgid;
__u32 ppid;
__u32 ruid;
__u32 rgid;
__u32 euid;
__u32 egid;
__u32 suid;
__u32 sgid;
__u32 fsuid;
__u32 fsgid;
__u32 spare0[1];
};
#endif
static int safe_int(const char *numstr, int *converted)
{
char *err = NULL;
long sli;
errno = 0;
sli = strtol(numstr, &err, 0);
if (errno == ERANGE && (sli == LONG_MAX || sli == LONG_MIN))
return -ERANGE;
if (errno != 0 && sli == 0)
return -EINVAL;
if (err == numstr || *err != '\0')
return -EINVAL;
if (sli > INT_MAX || sli < INT_MIN)
return -ERANGE;
*converted = (int)sli;
return 0;
}
static int char_left_gc(const char *buffer, size_t len)
{
size_t i;
for (i = 0; i < len; i++) {
if (buffer[i] == ' ' ||
buffer[i] == '\t')
continue;
return i;
}
return 0;
}
static int char_right_gc(const char *buffer, size_t len)
{
int i;
for (i = len - 1; i >= 0; i--) {
if (buffer[i] == ' ' ||
buffer[i] == '\t' ||
buffer[i] == '\n' ||
buffer[i] == '\0')
continue;
return i + 1;
}
return 0;
}
static char *trim_whitespace_in_place(char *buffer)
{
buffer += char_left_gc(buffer, strlen(buffer));
buffer[char_right_gc(buffer, strlen(buffer))] = '\0';
return buffer;
}
static pid_t get_pid_from_fdinfo_file(int pidfd, const char *key, size_t keylen)
{
int ret;
char path[512];
FILE *f;
size_t n = 0;
pid_t result = -1;
char *line = NULL;
snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", pidfd);
f = fopen(path, "re");
if (!f)
return -1;
while (getline(&line, &n, f) != -1) {
char *numstr;
if (strncmp(line, key, keylen))
continue;
numstr = trim_whitespace_in_place(line + 4);
ret = safe_int(numstr, &result);
if (ret < 0)
goto out;
break;
}
out:
free(line);
fclose(f);
return result;
}
int main(int argc, char **argv)
{
struct pidfd_info info = {
.request_mask = PIDFD_INFO_CGROUPID,
};
int pidfd = -1, ret = 1;
pid_t pid;
ksft_set_plan(4);
pidfd = sys_pidfd_open(-1, 0);
if (pidfd >= 0) {
ksft_print_msg(
"%s - succeeded to open pidfd for invalid pid -1\n",
strerror(errno));
goto on_error;
}
ksft_test_result_pass("do not allow invalid pid test: passed\n");
pidfd = sys_pidfd_open(getpid(), 1);
if (pidfd >= 0) {
ksft_print_msg(
"%s - succeeded to open pidfd with invalid flag value specified\n",
strerror(errno));
goto on_error;
}
ksft_test_result_pass("do not allow invalid flag test: passed\n");
pidfd = sys_pidfd_open(getpid(), 0);
if (pidfd < 0) {
ksft_print_msg("%s - failed to open pidfd\n", strerror(errno));
goto on_error;
}
ksft_test_result_pass("open a new pidfd test: passed\n");
pid = get_pid_from_fdinfo_file(pidfd, "Pid:", sizeof("Pid:") - 1);
ksft_print_msg("pidfd %d refers to process with pid %d\n", pidfd, pid);
if (ioctl(pidfd, PIDFD_GET_INFO, &info) < 0) {
ksft_print_msg("%s - failed to get info from pidfd\n", strerror(errno));
goto on_error;
}
if (info.pid != pid) {
ksft_print_msg("pid from fdinfo file %d does not match pid from ioctl %d\n",
pid, info.pid);
goto on_error;
}
if (info.ppid != getppid()) {
ksft_print_msg("ppid %d does not match ppid from ioctl %d\n",
pid, info.pid);
goto on_error;
}
if (info.ruid != getuid()) {
ksft_print_msg("uid %d does not match uid from ioctl %d\n",
getuid(), info.ruid);
goto on_error;
}
if (info.rgid != getgid()) {
ksft_print_msg("gid %d does not match gid from ioctl %d\n",
getgid(), info.rgid);
goto on_error;
}
if (info.euid != geteuid()) {
ksft_print_msg("euid %d does not match euid from ioctl %d\n",
geteuid(), info.euid);
goto on_error;
}
if (info.egid != getegid()) {
ksft_print_msg("egid %d does not match egid from ioctl %d\n",
getegid(), info.egid);
goto on_error;
}
if (info.suid != geteuid()) {
ksft_print_msg("suid %d does not match suid from ioctl %d\n",
geteuid(), info.suid);
goto on_error;
}
if (info.sgid != getegid()) {
ksft_print_msg("sgid %d does not match sgid from ioctl %d\n",
getegid(), info.sgid);
goto on_error;
}
if ((info.request_mask & PIDFD_INFO_CGROUPID) && info.cgroupid == 0) {
ksft_print_msg("cgroupid should not be 0 when PIDFD_INFO_CGROUPID is set\n");
goto on_error;
}
ksft_test_result_pass("get info from pidfd test: passed\n");
ret = 0;
on_error:
if (pidfd >= 0)
close(pidfd);
if (ret)
ksft_exit_fail();
ksft_exit_pass();
}
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