bean/src/chroot.c
2023-09-28 21:38:37 +03:00

102 lines
2.1 KiB
C

#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include "types.h"
#include "chroot.h"
#ifndef DT_DIR
#define DT_DIR 4
#endif
static const Mount mounts[] = {
{"none", "proc", "proc", 0, "failed to create a procfs"},
{"none", "sys", "sysfs", 0, "failed to create a sysfs"},
{"/dev", "dev", NULL, MS_BIND, "failed to bind /dev to dev in chroot"},
};
static const size_t mounts_sz = sizeof(mounts) / sizeof(mounts[0]);
void remove_directory(String path) {
DIR *dir;
struct dirent *entry;
char *filepath;
size_t fp_len, dn_len;
if ((dir = opendir(path)) == NULL)
return;
while ((entry = readdir(dir)) != NULL) {
if (strcmp(entry->d_name, ".") == 0 ||
strcmp(entry->d_name, "..") == 0) {
continue;
}
fp_len = strlen(path);
dn_len = strlen(entry->d_name);
filepath = malloc(fp_len + dn_len + 2); /* +2 for `/` and `\0` */
strncpy(filepath, path, fp_len);
filepath[fp_len] = '/';
strncat(filepath, entry->d_name, dn_len);
if (entry->d_type == DT_DIR)
remove_directory(filepath);
else
unlink(filepath);
free(filepath);
}
closedir(dir);
rmdir(path);
}
MString chroot_setup(String name) {
UChar idx;
const Mount *m;
if (mkdir(name, 0700) == -1)
return "failed to make the chroot environment directory";
chdir(name);
for (idx = 0; idx < mounts_sz; ++idx) {
m = &mounts[idx];
if (mkdir(m->to, 0700) == -1 ||
mount(m->from, m->to, m->fs, m->flags, NULL) == -1)
return m->msg;
}
chdir("..");
return NULL;
}
MString chroot_destroy(String name) {
UChar idx;
const Mount *m;
if (access(name, F_OK) != 0)
return "no such chroot environment found";
chdir(name);
for (idx = 0; idx < mounts_sz; ++idx) {
m = &mounts[idx];
if (umount(m->to) == -1)
return m->to;
}
chdir("..");
remove_directory(name);
return NULL;
}