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mirror of git://sourceware.org/git/lvm2.git synced 2024-12-22 17:35:59 +03:00
lvm2/lib/config/config.c
2011-12-18 21:56:03 +00:00

495 lines
11 KiB
C

/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "lib.h"
#include "config.h"
#include "crc.h"
#include "device.h"
#include "str_list.h"
#include "toolcontext.h"
#include "lvm-string.h"
#include "lvm-file.h"
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <ctype.h>
#include <assert.h>
struct config_file {
time_t timestamp;
off_t st_size;
char *filename;
int exists;
int keep_open;
struct device *dev;
};
/*
* public interface
*/
struct dm_config_tree *config_file_open(const char *filename, int keep_open)
{
struct dm_config_tree *cft = dm_config_create();
struct config_file *cf;
if (!cft)
return NULL;
cf = dm_pool_zalloc(cft->mem, sizeof(struct config_file));
if (!cf) goto fail;
cf->timestamp = 0;
cf->exists = 0;
cf->keep_open = keep_open;
dm_config_set_custom(cft, cf);
if (filename &&
!(cf->filename = dm_pool_strdup(cft->mem, filename))) {
log_error("Failed to duplicate filename.");
goto fail;
}
return cft;
fail:
dm_config_destroy(cft);
return NULL;
}
/*
* Doesn't populate filename if the file is empty.
*/
int config_file_check(struct dm_config_tree *cft, const char **filename, struct stat *info)
{
struct config_file *cf = dm_config_get_custom(cft);
struct stat _info;
if (!info)
info = &_info;
if (stat(cf->filename, info)) {
log_sys_error("stat", cf->filename);
cf->exists = 0;
return 0;
}
if (!S_ISREG(info->st_mode)) {
log_error("%s is not a regular file", cf->filename);
cf->exists = 0;
return 0;
}
cf->exists = 1;
cf->timestamp = info->st_ctime;
cf->st_size = info->st_size;
if (info->st_size == 0)
log_verbose("%s is empty", cf->filename);
else if (filename)
*filename = cf->filename;
return 1;
}
/*
* Return 1 if config files ought to be reloaded
*/
int config_file_changed(struct dm_config_tree *cft)
{
struct config_file *cf = dm_config_get_custom(cft);
struct stat info;
if (!cf->filename)
return 0;
if (stat(cf->filename, &info) == -1) {
/* Ignore a deleted config file: still use original data */
if (errno == ENOENT) {
if (!cf->exists)
return 0;
log_very_verbose("Config file %s has disappeared!",
cf->filename);
goto reload;
}
log_sys_error("stat", cf->filename);
log_error("Failed to reload configuration files");
return 0;
}
if (!S_ISREG(info.st_mode)) {
log_error("Configuration file %s is not a regular file",
cf->filename);
goto reload;
}
/* Unchanged? */
if (cf->timestamp == info.st_ctime && cf->st_size == info.st_size)
return 0;
reload:
log_verbose("Detected config file change to %s", cf->filename);
return 1;
}
void config_file_destroy(struct dm_config_tree *cft)
{
struct config_file *cf = dm_config_get_custom(cft);
if (cf && cf->dev)
dev_close(cf->dev);
dm_config_destroy(cft);
}
/*
* Returns config tree if it was removed.
*/
struct dm_config_tree *remove_overridden_config_tree(struct cmd_context *cmd)
{
// FIXME Replace cmd->cft with clean copy of merged lvm*.conf tree
struct dm_config_tree *old_cft = cmd->cft;
struct dm_config_tree *cft = dm_config_remove_cascaded_tree(cmd->cft);
if (!cft)
return NULL;
cmd->cft = cft;
return old_cft;
}
// FIXME Retain a copy of the string (or tree?) in cmd->cft_cmdline
// FIXME and merge into cmd->cft
int override_config_tree_from_string(struct cmd_context *cmd,
const char *config_settings)
{
struct dm_config_tree *cft_new;
if (!(cft_new = dm_config_from_string(config_settings))) {
log_error("Failed to set overridden configuration entries.");
return 1;
}
cmd->cft = dm_config_insert_cascaded_tree(cft_new, cmd->cft);
return 0;
}
int config_file_read_fd(struct dm_config_tree *cft, struct device *dev,
off_t offset, size_t size, off_t offset2, size_t size2,
checksum_fn_t checksum_fn, uint32_t checksum)
{
const char *fb, *fe;
int r = 0;
int use_mmap = 1;
off_t mmap_offset = 0;
char *buf = NULL;
/* Only use mmap with regular files */
if (!(dev->flags & DEV_REGULAR) || size2)
use_mmap = 0;
if (use_mmap) {
mmap_offset = offset % lvm_getpagesize();
/* memory map the file */
fb = mmap((caddr_t) 0, size + mmap_offset, PROT_READ,
MAP_PRIVATE, dev_fd(dev), offset - mmap_offset);
if (fb == (caddr_t) (-1)) {
log_sys_error("mmap", dev_name(dev));
goto out;
}
fb = fb + mmap_offset;
} else {
if (!(buf = dm_malloc(size + size2))) {
log_error("Failed to allocate circular buffer.");
return 0;
}
if (!dev_read_circular(dev, (uint64_t) offset, size,
(uint64_t) offset2, size2, buf)) {
goto out;
}
fb = buf;
}
if (checksum_fn && checksum !=
(checksum_fn(checksum_fn(INITIAL_CRC, (const uint8_t *)fb, size),
(const uint8_t *)(fb + size), size2))) {
log_error("%s: Checksum error", dev_name(dev));
goto out;
}
fe = fb + size + size2;
if (!dm_config_parse(cft, fb, fe))
goto_out;
r = 1;
out:
if (!use_mmap)
dm_free(buf);
else {
/* unmap the file */
if (munmap((char *) (fb - mmap_offset), size + mmap_offset)) {
log_sys_error("munmap", dev_name(dev));
r = 0;
}
}
return r;
}
int config_file_read(struct dm_config_tree *cft)
{
const char *filename = NULL;
struct config_file *cf = dm_config_get_custom(cft);
struct stat info;
int r;
if (!config_file_check(cft, &filename, &info))
return_0;
/* Nothing to do. E.g. empty file. */
if (!filename)
return 1;
if (!cf->dev) {
if (!(cf->dev = dev_create_file(filename, NULL, NULL, 1)))
return_0;
if (!dev_open_readonly_buffered(cf->dev))
return_0;
}
r = config_file_read_fd(cft, cf->dev, 0, (size_t) info.st_size, 0, 0,
(checksum_fn_t) NULL, 0);
if (!cf->keep_open) {
dev_close(cf->dev);
cf->dev = NULL;
}
return r;
}
time_t config_file_timestamp(struct dm_config_tree *cft)
{
struct config_file *cf = dm_config_get_custom(cft);
assert(cf);
return cf->timestamp;
}
const struct dm_config_node *find_config_tree_node(struct cmd_context *cmd,
const char *path)
{
return dm_config_tree_find_node(cmd->cft, path);
}
const char *find_config_tree_str(struct cmd_context *cmd,
const char *path, const char *fail)
{
return dm_config_tree_find_str(cmd->cft, path, fail);
}
const char *find_config_tree_str_allow_empty(struct cmd_context *cmd,
const char *path, const char *fail)
{
return dm_config_tree_find_str_allow_empty(cmd->cft, path, fail);
}
int find_config_tree_int(struct cmd_context *cmd, const char *path,
int fail)
{
return dm_config_tree_find_int(cmd->cft, path, fail);
}
int64_t find_config_tree_int64(struct cmd_context *cmd, const char *path, int64_t fail)
{
return dm_config_tree_find_int64(cmd->cft, path, fail);
}
float find_config_tree_float(struct cmd_context *cmd, const char *path,
float fail)
{
return dm_config_tree_find_float(cmd->cft, path, fail);
}
int find_config_tree_bool(struct cmd_context *cmd, const char *path, int fail)
{
return dm_config_tree_find_bool(cmd->cft, path, fail);
}
/* Insert cn2 after cn1 */
static void _insert_config_node(struct dm_config_node **cn1,
struct dm_config_node *cn2)
{
if (!*cn1) {
*cn1 = cn2;
cn2->sib = NULL;
} else {
cn2->sib = (*cn1)->sib;
(*cn1)->sib = cn2;
}
}
/*
* Merge section cn2 into section cn1 (which has the same name)
* overwriting any existing cn1 nodes with matching names.
*/
static void _merge_section(struct dm_config_node *cn1, struct dm_config_node *cn2)
{
struct dm_config_node *cn, *nextn, *oldn;
struct dm_config_value *cv;
for (cn = cn2->child; cn; cn = nextn) {
nextn = cn->sib;
/* Skip "tags" */
if (!strcmp(cn->key, "tags"))
continue;
/* Subsection? */
if (!cn->v)
/* Ignore - we don't have any of these yet */
continue;
/* Not already present? */
if (!(oldn = dm_config_find_node(cn1->child, cn->key))) {
_insert_config_node(&cn1->child, cn);
continue;
}
/* Merge certain value lists */
if ((!strcmp(cn1->key, "activation") &&
!strcmp(cn->key, "volume_list")) ||
(!strcmp(cn1->key, "devices") &&
(!strcmp(cn->key, "filter") || !strcmp(cn->key, "types")))) {
cv = cn->v;
while (cv->next)
cv = cv->next;
cv->next = oldn->v;
}
/* Replace values */
oldn->v = cn->v;
}
}
static int _match_host_tags(struct dm_list *tags, const struct dm_config_node *tn)
{
const struct dm_config_value *tv;
const char *str;
for (tv = tn->v; tv; tv = tv->next) {
if (tv->type != DM_CFG_STRING)
continue;
str = tv->v.str;
if (*str == '@')
str++;
if (!*str)
continue;
if (str_list_match_item(tags, str))
return 1;
}
return 0;
}
/* Destructively merge a new config tree into an existing one */
int merge_config_tree(struct cmd_context *cmd, struct dm_config_tree *cft,
struct dm_config_tree *newdata)
{
struct dm_config_node *root = cft->root;
struct dm_config_node *cn, *nextn, *oldn, *cn2;
const struct dm_config_node *tn;
for (cn = newdata->root; cn; cn = nextn) {
nextn = cn->sib;
/* Ignore tags section */
if (!strcmp(cn->key, "tags"))
continue;
/* If there's a tags node, skip if host tags don't match */
if ((tn = dm_config_find_node(cn->child, "tags"))) {
if (!_match_host_tags(&cmd->tags, tn))
continue;
}
if (!(oldn = dm_config_find_node(root, cn->key))) {
_insert_config_node(&cft->root, cn);
/* Remove any "tags" nodes */
for (cn2 = cn->child; cn2; cn2 = cn2->sib) {
if (!strcmp(cn2->key, "tags")) {
cn->child = cn2->sib;
continue;
}
if (cn2->sib && !strcmp(cn2->sib->key, "tags")) {
cn2->sib = cn2->sib->sib;
continue;
}
}
continue;
}
_merge_section(oldn, cn);
}
return 1;
}
static int _putline_fn(const char *line, void *baton) {
FILE *fp = baton;
fprintf(fp, "%s\n", line);
return 1;
};
int config_write(struct dm_config_tree *cft, const char *file,
int argc, char **argv)
{
const struct dm_config_node *cn;
int r = 1;
FILE *fp = NULL;
if (!file) {
fp = stdout;
file = "stdout";
} else if (!(fp = fopen(file, "w"))) {
log_sys_error("open", file);
return 0;
}
log_verbose("Dumping configuration to %s", file);
if (!argc) {
if (!dm_config_write_node(cft->root, _putline_fn, fp)) {
log_error("Failure while writing to %s", file);
r = 0;
}
} else while (argc--) {
if ((cn = dm_config_find_node(cft->root, *argv))) {
if (!dm_config_write_node(cn, _putline_fn, fp)) {
log_error("Failure while writing to %s", file);
r = 0;
}
} else {
log_error("Configuration node %s not found", *argv);
r = 0;
}
argv++;
}
if (fp && dm_fclose(fp)) {
stack;
r = 0;
}
return r;
}