mirror_lxc/src/lxc/utils.c
Sidnei da Silva 055af165ef Assume a default thin pool named 'lxc'.
Will fallback to no thinpool if not present or if thin pool provided on the command line does not exist.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2013-10-21 16:12:19 -05:00

979 lines
20 KiB
C

/*
* lxc: linux Container library
*
* (C) Copyright IBM Corp. 2007, 2008
*
* Authors:
* Daniel Lezcano <daniel.lezcano at free.fr>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define _GNU_SOURCE
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <dirent.h>
#include <fcntl.h>
#include <libgen.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <assert.h>
#ifndef HAVE_GETLINE
#ifdef HAVE_FGETLN
#include <../include/getline.h>
#endif
#endif
#include "utils.h"
#include "log.h"
#include "lxclock.h"
lxc_log_define(lxc_utils, lxc);
static int _recursive_rmdir_onedev(char *dirname, dev_t pdev)
{
struct dirent dirent, *direntp;
DIR *dir;
int ret, failed=0;
char pathname[MAXPATHLEN];
process_lock();
dir = opendir(dirname);
process_unlock();
if (!dir) {
ERROR("%s: failed to open %s", __func__, dirname);
return 0;
}
while (!readdir_r(dir, &dirent, &direntp)) {
struct stat mystat;
int rc;
if (!direntp)
break;
if (!strcmp(direntp->d_name, ".") ||
!strcmp(direntp->d_name, ".."))
continue;
rc = snprintf(pathname, MAXPATHLEN, "%s/%s", dirname, direntp->d_name);
if (rc < 0 || rc >= MAXPATHLEN) {
ERROR("pathname too long");
failed=1;
continue;
}
ret = lstat(pathname, &mystat);
if (ret) {
ERROR("%s: failed to stat %s", __func__, pathname);
failed=1;
continue;
}
if (mystat.st_dev != pdev)
continue;
if (S_ISDIR(mystat.st_mode)) {
if (!_recursive_rmdir_onedev(pathname, pdev))
failed=1;
} else {
if (unlink(pathname) < 0) {
ERROR("%s: failed to delete %s", __func__, pathname);
failed=1;
}
}
}
if (rmdir(dirname) < 0) {
ERROR("%s: failed to delete %s", __func__, dirname);
failed=1;
}
process_lock();
ret = closedir(dir);
process_unlock();
if (ret) {
ERROR("%s: failed to close directory %s", __func__, dirname);
failed=1;
}
return !failed;
}
/* returns 1 on success, 0 if there were any failures */
extern int lxc_rmdir_onedev(char *path)
{
struct stat mystat;
if (lstat(path, &mystat) < 0) {
ERROR("%s: failed to stat %s", __func__, path);
return 0;
}
return _recursive_rmdir_onedev(path, mystat.st_dev);
}
static int mount_fs(const char *source, const char *target, const char *type)
{
/* the umount may fail */
if (umount(target))
WARN("failed to unmount %s : %s", target, strerror(errno));
if (mount(source, target, type, 0, NULL)) {
ERROR("failed to mount %s : %s", target, strerror(errno));
return -1;
}
DEBUG("'%s' mounted on '%s'", source, target);
return 0;
}
extern int lxc_setup_fs(void)
{
if (mount_fs("proc", "/proc", "proc"))
return -1;
/* if we can't mount /dev/shm, continue anyway */
if (mount_fs("shmfs", "/dev/shm", "tmpfs"))
INFO("failed to mount /dev/shm");
/* If we were able to mount /dev/shm, then /dev exists */
/* Sure, but it's read-only per config :) */
if (access("/dev/mqueue", F_OK) && mkdir("/dev/mqueue", 0666)) {
DEBUG("failed to create '/dev/mqueue'");
return 0;
}
/* continue even without posix message queue support */
if (mount_fs("mqueue", "/dev/mqueue", "mqueue"))
INFO("failed to mount /dev/mqueue");
return 0;
}
/* borrowed from iproute2 */
extern int get_u16(unsigned short *val, const char *arg, int base)
{
unsigned long res;
char *ptr;
if (!arg || !*arg)
return -1;
res = strtoul(arg, &ptr, base);
if (!ptr || ptr == arg || *ptr || res > 0xFFFF)
return -1;
*val = res;
return 0;
}
extern int mkdir_p(const char *dir, mode_t mode)
{
const char *tmp = dir;
const char *orig = dir;
char *makeme;
do {
dir = tmp + strspn(tmp, "/");
tmp = dir + strcspn(dir, "/");
makeme = strndup(orig, dir - orig);
if (*makeme) {
if (mkdir(makeme, mode) && errno != EEXIST) {
SYSERROR("failed to create directory '%s'\n", makeme);
free(makeme);
return -1;
}
}
free(makeme);
} while(tmp != dir);
return 0;
}
extern void remove_trailing_slashes(char *p)
{
int l = strlen(p);
while (--l >= 0 && (p[l] == '/' || p[l] == '\n'))
p[l] = '\0';
}
static char *copy_global_config_value(char *p)
{
int len = strlen(p);
char *retbuf;
if (len < 1)
return NULL;
if (p[len-1] == '\n') {
p[len-1] = '\0';
len--;
}
retbuf = malloc(len+1);
if (!retbuf)
return NULL;
strcpy(retbuf, p);
return retbuf;
}
#define DEFAULT_VG "lxc"
#define DEFAULT_THIN_POOL "lxc"
#define DEFAULT_ZFSROOT "lxc"
const char *lxc_global_config_value(const char *option_name)
{
static const char *options[][2] = {
{ "lvm_vg", DEFAULT_VG },
{ "lvm_thin_pool", DEFAULT_THIN_POOL },
{ "zfsroot", DEFAULT_ZFSROOT },
{ "lxcpath", LXCPATH },
{ "cgroup.pattern", DEFAULT_CGROUP_PATTERN },
{ "cgroup.use", NULL },
{ NULL, NULL },
};
static const char *values[sizeof(options) / sizeof(options[0])] = { 0 };
const char *(*ptr)[2];
size_t i;
char buf[1024], *p, *p2;
FILE *fin = NULL;
for (i = 0, ptr = options; (*ptr)[0]; ptr++, i++) {
if (!strcmp(option_name, (*ptr)[0]))
break;
}
if (!(*ptr)[0]) {
errno = EINVAL;
return NULL;
}
if (values[i])
return values[i];
process_lock();
fin = fopen_cloexec(LXC_GLOBAL_CONF, "r");
process_unlock();
if (fin) {
while (fgets(buf, 1024, fin)) {
if (buf[0] == '#')
continue;
p = strstr(buf, option_name);
if (!p)
continue;
/* see if there was just white space in front
* of the option name
*/
for (p2 = buf; p2 < p; p2++) {
if (*p2 != ' ' && *p2 != '\t')
break;
}
if (p2 < p)
continue;
p = strchr(p, '=');
if (!p)
continue;
/* see if there was just white space after
* the option name
*/
for (p2 += strlen(option_name); p2 < p; p2++) {
if (*p2 != ' ' && *p2 != '\t')
break;
}
if (p2 < p)
continue;
p++;
while (*p && (*p == ' ' || *p == '\t')) p++;
if (!*p)
continue;
values[i] = copy_global_config_value(p);
goto out;
}
}
/* could not find value, use default */
values[i] = (*ptr)[1];
/* special case: if default value is NULL,
* and there is no config, don't view that
* as an error... */
if (!values[i])
errno = 0;
out:
process_lock();
if (fin)
fclose(fin);
process_unlock();
return values[i];
}
const char *default_lvm_vg(void)
{
return lxc_global_config_value("lvm_vg");
}
const char *default_lvm_thin_pool(void)
{
return lxc_global_config_value("lvm_thin_pool");
}
const char *default_zfs_root(void)
{
return lxc_global_config_value("zfsroot");
}
const char *default_lxc_path(void)
{
return lxc_global_config_value("lxcpath");
}
const char *get_rundir()
{
const char *rundir;
rundir = getenv("XDG_RUNTIME_DIR");
if (geteuid() == 0 || rundir == NULL)
rundir = "/run";
return rundir;
}
int wait_for_pid(pid_t pid)
{
int status, ret;
again:
ret = waitpid(pid, &status, 0);
if (ret == -1) {
if (errno == EINTR)
goto again;
return -1;
}
if (ret != pid)
goto again;
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
return -1;
return 0;
}
int lxc_wait_for_pid_status(pid_t pid)
{
int status, ret;
again:
ret = waitpid(pid, &status, 0);
if (ret == -1) {
if (errno == EINTR)
goto again;
return -1;
}
if (ret != pid)
goto again;
return status;
}
ssize_t lxc_write_nointr(int fd, const void* buf, size_t count)
{
ssize_t ret;
again:
ret = write(fd, buf, count);
if (ret < 0 && errno == EINTR)
goto again;
return ret;
}
ssize_t lxc_read_nointr(int fd, void* buf, size_t count)
{
ssize_t ret;
again:
ret = read(fd, buf, count);
if (ret < 0 && errno == EINTR)
goto again;
return ret;
}
ssize_t lxc_read_nointr_expect(int fd, void* buf, size_t count, const void* expected_buf)
{
ssize_t ret;
ret = lxc_read_nointr(fd, buf, count);
if (ret <= 0)
return ret;
if ((size_t)ret != count)
return -1;
if (expected_buf && memcmp(buf, expected_buf, count) != 0) {
errno = EINVAL;
return -1;
}
return ret;
}
static inline int lock_fclose(FILE *f)
{
int ret;
process_lock();
ret = fclose(f);
process_unlock();
return ret;
}
#if HAVE_LIBGNUTLS
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
__attribute__((constructor))
static void gnutls_lxc_init(void)
{
gnutls_global_init();
}
int sha1sum_file(char *fnam, unsigned char *digest)
{
char *buf;
int ret;
FILE *f;
long flen;
if (!fnam)
return -1;
process_lock();
f = fopen_cloexec(fnam, "r");
process_unlock();
if (f < 0) {
SYSERROR("Error opening template");
return -1;
}
if (fseek(f, 0, SEEK_END) < 0) {
SYSERROR("Error seeking to end of template");
lock_fclose(f);
return -1;
}
if ((flen = ftell(f)) < 0) {
SYSERROR("Error telling size of template");
lock_fclose(f);
return -1;
}
if (fseek(f, 0, SEEK_SET) < 0) {
SYSERROR("Error seeking to start of template");
lock_fclose(f);
return -1;
}
if ((buf = malloc(flen+1)) == NULL) {
SYSERROR("Out of memory");
lock_fclose(f);
return -1;
}
if (fread(buf, 1, flen, f) != flen) {
SYSERROR("Failure reading template");
free(buf);
lock_fclose(f);
return -1;
}
if (lock_fclose(f) < 0) {
SYSERROR("Failre closing template");
free(buf);
return -1;
}
buf[flen] = '\0';
ret = gnutls_hash_fast(GNUTLS_DIG_SHA1, buf, flen, (void *)digest);
free(buf);
return ret;
}
#endif
char** lxc_va_arg_list_to_argv(va_list ap, size_t skip, int do_strdup)
{
va_list ap2;
size_t count = 1 + skip;
char **result;
/* first determine size of argument list, we don't want to reallocate
* constantly...
*/
va_copy(ap2, ap);
while (1) {
char* arg = va_arg(ap2, char*);
if (!arg)
break;
count++;
}
va_end(ap2);
result = calloc(count, sizeof(char*));
if (!result)
return NULL;
count = skip;
while (1) {
char* arg = va_arg(ap, char*);
if (!arg)
break;
arg = do_strdup ? strdup(arg) : arg;
if (!arg)
goto oom;
result[count++] = arg;
}
/* calloc has already set last element to NULL*/
return result;
oom:
free(result);
return NULL;
}
const char** lxc_va_arg_list_to_argv_const(va_list ap, size_t skip)
{
return (const char**)lxc_va_arg_list_to_argv(ap, skip, 0);
}
/*
* fopen_cloexec: must be called with process_lock() held
* if it is needed.
*/
FILE *fopen_cloexec(const char *path, const char *mode)
{
int open_mode = 0;
int step = 0;
int fd;
int saved_errno = 0;
FILE *ret;
if (!strncmp(mode, "r+", 2)) {
open_mode = O_RDWR;
step = 2;
} else if (!strncmp(mode, "r", 1)) {
open_mode = O_RDONLY;
step = 1;
} else if (!strncmp(mode, "w+", 2)) {
open_mode = O_RDWR | O_TRUNC | O_CREAT;
step = 2;
} else if (!strncmp(mode, "w", 1)) {
open_mode = O_WRONLY | O_TRUNC | O_CREAT;
step = 1;
} else if (!strncmp(mode, "a+", 2)) {
open_mode = O_RDWR | O_CREAT | O_APPEND;
step = 2;
} else if (!strncmp(mode, "a", 1)) {
open_mode = O_WRONLY | O_CREAT | O_APPEND;
step = 1;
}
for (; mode[step]; step++)
if (mode[step] == 'x')
open_mode |= O_EXCL;
open_mode |= O_CLOEXEC;
fd = open(path, open_mode, 0666);
if (fd < 0)
return NULL;
ret = fdopen(fd, mode);
saved_errno = errno;
if (!ret)
close(fd);
errno = saved_errno;
return ret;
}
char *lxc_string_replace(const char *needle, const char *replacement, const char *haystack)
{
ssize_t len = -1, saved_len = -1;
char *result = NULL;
size_t replacement_len = strlen(replacement);
size_t needle_len = strlen(needle);
/* should be executed exactly twice */
while (len == -1 || result == NULL) {
char *p;
char *last_p;
ssize_t part_len;
if (len != -1) {
result = calloc(1, len + 1);
if (!result)
return NULL;
saved_len = len;
}
len = 0;
for (last_p = (char *)haystack, p = strstr(last_p, needle); p; last_p = p, p = strstr(last_p, needle)) {
part_len = (ssize_t)(p - last_p);
if (result && part_len > 0)
memcpy(&result[len], last_p, part_len);
len += part_len;
if (result && replacement_len > 0)
memcpy(&result[len], replacement, replacement_len);
len += replacement_len;
p += needle_len;
}
part_len = strlen(last_p);
if (result && part_len > 0)
memcpy(&result[len], last_p, part_len);
len += part_len;
}
/* make sure we did the same thing twice,
* once for calculating length, the other
* time for copying data */
assert(saved_len == len);
/* make sure we didn't overwrite any buffer,
* due to calloc the string should be 0-terminated */
assert(result[len] == '\0');
return result;
}
bool lxc_string_in_array(const char *needle, const char **haystack)
{
for (; haystack && *haystack; haystack++)
if (!strcmp(needle, *haystack))
return true;
return false;
}
char *lxc_string_join(const char *sep, const char **parts, bool use_as_prefix)
{
char *result;
char **p;
size_t sep_len = strlen(sep);
size_t result_len = use_as_prefix * sep_len;
/* calculate new string length */
for (p = (char **)parts; *p; p++)
result_len += (p > (char **)parts) * sep_len + strlen(*p);
result = calloc(result_len + 1, 1);
if (!result)
return NULL;
if (use_as_prefix)
strcpy(result, sep);
for (p = (char **)parts; *p; p++) {
if (p > (char **)parts)
strcat(result, sep);
strcat(result, *p);
}
return result;
}
char **lxc_normalize_path(const char *path)
{
char **components;
char **p;
size_t components_len = 0;
size_t pos = 0;
components = lxc_string_split(path, '/');
if (!components)
return NULL;
for (p = components; *p; p++)
components_len++;
/* resolve '.' and '..' */
for (pos = 0; pos < components_len; ) {
if (!strcmp(components[pos], ".") || (!strcmp(components[pos], "..") && pos == 0)) {
/* eat this element */
free(components[pos]);
memmove(&components[pos], &components[pos+1], sizeof(char *) * (components_len - pos));
components_len--;
} else if (!strcmp(components[pos], "..")) {
/* eat this and the previous element */
free(components[pos - 1]);
free(components[pos]);
memmove(&components[pos-1], &components[pos+1], sizeof(char *) * (components_len - pos));
components_len -= 2;
pos--;
} else {
pos++;
}
}
return components;
}
char *lxc_append_paths(const char *first, const char *second)
{
size_t len = strlen(first) + strlen(second) + 1;
const char *pattern = "%s%s";
char *result = NULL;
if (second[0] != '/') {
len += 1;
pattern = "%s/%s";
}
result = calloc(1, len);
if (!result)
return NULL;
snprintf(result, len, pattern, first, second);
return result;
}
bool lxc_string_in_list(const char *needle, const char *haystack, char _sep)
{
char *token, *str, *saveptr = NULL;
char sep[2] = { _sep, '\0' };
if (!haystack || !needle)
return 0;
str = alloca(strlen(haystack)+1);
strcpy(str, haystack);
for (; (token = strtok_r(str, sep, &saveptr)); str = NULL) {
if (strcmp(needle, token) == 0)
return 1;
}
return 0;
}
char **lxc_string_split(const char *string, char _sep)
{
char *token, *str, *saveptr = NULL;
char sep[2] = { _sep, '\0' };
char **result = NULL;
size_t result_capacity = 0;
size_t result_count = 0;
int r, saved_errno;
if (!string)
return calloc(1, sizeof(char *));
str = alloca(strlen(string)+1);
strcpy(str, string);
for (; (token = strtok_r(str, sep, &saveptr)); str = NULL) {
r = lxc_grow_array((void ***)&result, &result_capacity, result_count + 1, 16);
if (r < 0)
goto error_out;
result[result_count] = strdup(token);
if (!result[result_count])
goto error_out;
result_count++;
}
/* if we allocated too much, reduce it */
return realloc(result, (result_count + 1) * sizeof(char *));
error_out:
saved_errno = errno;
lxc_free_array((void **)result, free);
errno = saved_errno;
return NULL;
}
char **lxc_string_split_and_trim(const char *string, char _sep)
{
char *token, *str, *saveptr = NULL;
char sep[2] = { _sep, '\0' };
char **result = NULL;
size_t result_capacity = 0;
size_t result_count = 0;
int r, saved_errno;
size_t i = 0;
if (!string)
return calloc(1, sizeof(char *));
str = alloca(strlen(string)+1);
strcpy(str, string);
for (; (token = strtok_r(str, sep, &saveptr)); str = NULL) {
while (token[0] == ' ' || token[0] == '\t')
token++;
i = strlen(token);
while (i > 0 && (token[i - 1] == ' ' || token[i - 1] == '\t')) {
token[i - 1] = '\0';
i--;
}
r = lxc_grow_array((void ***)&result, &result_capacity, result_count + 1, 16);
if (r < 0)
goto error_out;
result[result_count] = strdup(token);
if (!result[result_count])
goto error_out;
result_count++;
}
/* if we allocated too much, reduce it */
return realloc(result, (result_count + 1) * sizeof(char *));
error_out:
saved_errno = errno;
lxc_free_array((void **)result, free);
errno = saved_errno;
return NULL;
}
void lxc_free_array(void **array, lxc_free_fn element_free_fn)
{
void **p;
for (p = array; p && *p; p++)
element_free_fn(*p);
free((void*)array);
}
int lxc_grow_array(void ***array, size_t* capacity, size_t new_size, size_t capacity_increment)
{
size_t new_capacity;
void **new_array;
/* first time around, catch some trivial mistakes of the user
* only initializing one of these */
if (!*array || !*capacity) {
*array = NULL;
*capacity = 0;
}
new_capacity = *capacity;
while (new_size + 1 > new_capacity)
new_capacity += capacity_increment;
if (new_capacity != *capacity) {
/* we have to reallocate */
new_array = realloc(*array, new_capacity * sizeof(void *));
if (!new_array)
return -1;
memset(&new_array[*capacity], 0, (new_capacity - (*capacity)) * sizeof(void *));
*array = new_array;
*capacity = new_capacity;
}
/* array has sufficient elements */
return 0;
}
size_t lxc_array_len(void **array)
{
void **p;
size_t result = 0;
for (p = array; p && *p; p++)
result++;
return result;
}
void **lxc_dup_array(void **array, lxc_dup_fn element_dup_fn, lxc_free_fn element_free_fn)
{
size_t l = lxc_array_len(array);
void **result = calloc(l + 1, sizeof(void *));
void **pp;
void *p;
int saved_errno = 0;
if (!result)
return NULL;
for (l = 0, pp = array; pp && *pp; pp++, l++) {
p = element_dup_fn(*pp);
if (!p) {
saved_errno = errno;
lxc_free_array(result, element_free_fn);
errno = saved_errno;
return NULL;
}
result[l] = p;
}
return result;
}
int lxc_write_to_file(const char *filename, const void* buf, size_t count, bool add_newline)
{
int fd, saved_errno;
ssize_t ret;
process_lock();
fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, 0666);
process_unlock();
if (fd < 0)
return -1;
ret = lxc_write_nointr(fd, buf, count);
if (ret < 0)
goto out_error;
if ((size_t)ret != count)
goto out_error;
if (add_newline) {
ret = lxc_write_nointr(fd, "\n", 1);
if (ret != 1)
goto out_error;
}
process_lock();
close(fd);
process_unlock();
return 0;
out_error:
saved_errno = errno;
process_lock();
close(fd);
process_unlock();
errno = saved_errno;
return -1;
}
int lxc_read_from_file(const char *filename, void* buf, size_t count)
{
int fd = -1, saved_errno;
ssize_t ret;
process_lock();
fd = open(filename, O_RDONLY | O_CLOEXEC);
process_unlock();
if (fd < 0)
return -1;
if (!buf || !count) {
char buf2[100];
size_t count2 = 0;
while ((ret = read(fd, buf2, 100)) > 0)
count2 += ret;
if (ret >= 0)
ret = count2;
} else {
memset(buf, 0, count);
ret = read(fd, buf, count);
}
if (ret < 0)
ERROR("read %s: %s", filename, strerror(errno));
saved_errno = errno;
process_lock();
close(fd);
process_unlock();
errno = saved_errno;
return ret;
}
void **lxc_append_null_to_array(void **array, size_t count)
{
void **temp;
/* Append NULL to the array */
if (count) {
temp = realloc(array, (count + 1) * sizeof(*array));
if (!temp) {
int i;
for (i = 0; i < count; i++)
free(array[i]);
free(array);
return NULL;
}
array = temp;
array[count] = NULL;
}
return array;
}