udev_rules_parse.c revision 319c6700165dc38d7f813ff646bff0196f2aafe6
/*
* udev_rules_parse.c
*
* Userspace devfs
*
* Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2003-2005 Kay Sievers <kay.sievers@vrfy.org>
*
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation version 2 of the License.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <sys/stat.h>
#include <errno.h>
#include "udev_libc_wrapper.h"
#include "udev.h"
#include "udev_utils.h"
#include "logging.h"
#include "udev_rules.h"
/* rules parsed from .rules files*/
static LIST_HEAD(rules_list);
static struct list_head *rules_list_current;
/* mapped compiled rules stored on disk */
static struct udev_rule *rules_array = NULL;
static size_t rules_array_current;
static size_t rules_array_size = 0;
static size_t rules_count = 0;
int udev_rules_iter_init(void)
{
rules_list_current = rules_list.next;
rules_array_current = 0;
return 0;
}
struct udev_rule *udev_rules_iter_next(void)
{
static struct udev_rule *rule;
if (rules_array) {
if (rules_array_current >= rules_count)
return NULL;
rule = &rules_array[rules_array_current];
rules_array_current++;
} else {
dbg("head=%p current=%p next=%p", &rules_list, rules_list_current, rules_list_current->next);
if (rules_list_current == &rules_list)
return NULL;
rule = list_entry(rules_list_current, struct udev_rule, node);
rules_list_current = rules_list_current->next;
}
return rule;
}
static int add_rule_to_list(struct udev_rule *rule)
{
struct udev_rule *tmp_rule;
tmp_rule = malloc(sizeof(*tmp_rule));
if (tmp_rule == NULL)
return -ENOMEM;
memcpy(tmp_rule, rule, sizeof(struct udev_rule));
list_add_tail(&tmp_rule->node, &rules_list);
dbg("name='%s', symlink='%s', bus='%s', id='%s', "
"sysfs_file[0]='%s', sysfs_value[0]='%s', "
"kernel='%s', program='%s', result='%s', "
"owner='%s', group='%s', mode=%#o, "
"all_partions=%u, ignore_remove=%u, ignore_device=%u, last_rule=%u",
rule->name, rule->symlink, rule->bus, rule->id,
rule->sysfs_pair[0].name, rule->sysfs_pair[0].value,
rule->kernel, rule->program, rule->result, rule->owner, rule->group, rule->mode,
rule->partitions, rule->ignore_remove, rule->ignore_device, rule->last_rule);
return 0;
}
static int get_key(char **line, char **key, enum key_operation *operation, char **value)
{
char *linepos;
char *temp;
linepos = *line;
if (!linepos)
return -1;
/* skip whitespace */
while (isspace(linepos[0]) || linepos[0] == ',')
linepos++;
/* get the key */
*key = linepos;
while (1) {
linepos++;
if (linepos[0] == '\0')
return -1;
if (isspace(linepos[0]))
break;
if (linepos[0] == '=')
break;
if (linepos[0] == '+')
break;
if (linepos[0] == '!')
break;
if (linepos[0] == ':')
break;
}
/* remember end of key */
temp = linepos;
/* skip whitespace after key */
while (isspace(linepos[0]))
linepos++;
/* get operation type */
if (linepos[0] == '=' && linepos[1] == '=') {
*operation = KEY_OP_MATCH;
linepos += 2;
dbg("operator=match");
} else if (linepos[0] == '!' && linepos[1] == '=') {
*operation = KEY_OP_NOMATCH;
linepos += 2;
dbg("operator=nomatch");
} else if (linepos[0] == '+' && linepos[1] == '=') {
*operation = KEY_OP_ADD;
linepos += 2;
dbg("operator=add");
} else if (linepos[0] == '=') {
*operation = KEY_OP_ASSIGN;
linepos++;
dbg("operator=assign");
} else if (linepos[0] == ':' && linepos[1] == '=') {
*operation = KEY_OP_ASSIGN_FINAL;
linepos += 2;
dbg("operator=assign_final");
} else
return -1;
/* terminate key */
temp[0] = '\0';
dbg("key='%s'", *key);
/* skip whitespace after operator */
while (isspace(linepos[0]))
linepos++;
/* get the value*/
if (linepos[0] == '"')
linepos++;
else
return -1;
*value = linepos;
temp = strchr(linepos, '"');
if (!temp)
return -1;
temp[0] = '\0';
temp++;
dbg("value='%s'", *value);
/* move line to next key */
*line = temp;
return 0;
}
/* extract possible KEY{attr} */
static char *get_key_attribute(char *str)
{
char *pos;
char *attr;
attr = strchr(str, '{');
if (attr != NULL) {
attr++;
pos = strchr(attr, '}');
if (pos == NULL) {
err("missing closing brace for format");
return NULL;
}
pos[0] = '\0';
dbg("attribute='%s'", attr);
return attr;
}
return NULL;
}
static int rules_parse(const char *filename)
{
char line[LINE_SIZE];
char *bufline;
int lineno;
char *linepos;
char *attr;
char *buf;
size_t bufsize;
size_t cur;
size_t count;
int program_given = 0;
int valid;
int retval = 0;
struct udev_rule rule;
if (file_map(filename, &buf, &bufsize) != 0) {
err("can't open '%s' as rules file", filename);
return -1;
}
dbg("reading '%s' as rules file", filename);
/* loop through the whole file */
cur = 0;
lineno = 0;
while (cur < bufsize) {
unsigned int i, j;
count = buf_get_line(buf, bufsize, cur);
bufline = &buf[cur];
cur += count+1;
lineno++;
if (count >= sizeof(line)) {
info("line too long, rule skipped %s, line %d", filename, lineno);
continue;
}
/* eat the whitespace */
while ((count > 0) && isspace(bufline[0])) {
bufline++;
count--;
}
if (count == 0)
continue;
/* see if this is a comment */
if (bufline[0] == COMMENT_CHARACTER)
continue;
/* skip backslash and newline from multi line rules */
for (i = j = 0; i < count; i++) {
if (bufline[i] == '\\' && bufline[i+1] == '\n')
continue;
line[j++] = bufline[i];
}
line[j] = '\0';
dbg("read '%s'", line);
/* get all known keys */
memset(&rule, 0x00, sizeof(struct udev_rule));
linepos = line;
valid = 0;
while (1) {
char *key;
char *value;
enum key_operation operation = KEY_OP_UNSET;
retval = get_key(&linepos, &key, &operation, &value);
if (retval)
break;
if (strcasecmp(key, KEY_KERNEL) == 0) {
strlcpy(rule.kernel, value, sizeof(rule.kernel));
rule.kernel_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_SUBSYSTEM) == 0) {
strlcpy(rule.subsystem, value, sizeof(rule.subsystem));
rule.subsystem_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_ACTION) == 0) {
strlcpy(rule.action, value, sizeof(rule.action));
rule.action_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_DEVPATH) == 0) {
strlcpy(rule.devpath, value, sizeof(rule.devpath));
rule.devpath_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_BUS) == 0) {
strlcpy(rule.bus, value, sizeof(rule.bus));
rule.bus_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_ID) == 0) {
strlcpy(rule.id, value, sizeof(rule.id));
rule.id_operation = operation;
valid = 1;
continue;
}
if (strncasecmp(key, KEY_SYSFS, sizeof(KEY_SYSFS)-1) == 0) {
struct key_pair *pair;
if (rule.sysfs_pair_count >= KEY_SYSFS_PAIRS_MAX) {
err("skip rule, to many " KEY_SYSFS " keys in a single rule");
goto error;
}
pair = &rule.sysfs_pair[rule.sysfs_pair_count];
attr = get_key_attribute(key + sizeof(KEY_SYSFS)-1);
if (attr == NULL) {
err("error parsing " KEY_SYSFS " attribute");
goto error;
}
strlcpy(pair->name, attr, sizeof(pair->name));
strlcpy(pair->value, value, sizeof(pair->value));
pair->operation = operation;
rule.sysfs_pair_count++;
valid = 1;
continue;
}
if (strncasecmp(key, KEY_ENV, sizeof(KEY_ENV)-1) == 0) {
struct key_pair *pair;
if (rule.env_pair_count >= KEY_ENV_PAIRS_MAX) {
err("skip rule, to many " KEY_ENV " keys in a single rule");
goto error;
}
pair = &rule.env_pair[rule.env_pair_count];
attr = get_key_attribute(key + sizeof(KEY_ENV)-1);
if (attr == NULL) {
err("error parsing " KEY_ENV " attribute");
continue;
}
strlcpy(pair->name, attr, sizeof(pair->name));
strlcpy(pair->value, value, sizeof(pair->value));
pair->operation = operation;
rule.env_pair_count++;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_MODALIAS) == 0) {
strlcpy(rule.modalias, value, sizeof(rule.modalias));
rule.modalias_operation = operation;
valid = 1;
continue;
}
if (strncasecmp(key, KEY_IMPORT, sizeof(KEY_IMPORT)-1) == 0) {
attr = get_key_attribute(key + sizeof(KEY_IMPORT)-1);
if (attr && strstr(attr, "exec")) {
dbg(KEY_IMPORT" will be executed");
rule.import_exec = 1;
}
strlcpy(rule.import, value, sizeof(rule.import));
rule.import_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_DRIVER) == 0) {
strlcpy(rule.driver, value, sizeof(rule.driver));
rule.driver_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_RESULT) == 0) {
strlcpy(rule.result, value, sizeof(rule.result));
rule.result_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_PROGRAM) == 0) {
strlcpy(rule.program, value, sizeof(rule.program));
rule.program_operation = operation;
program_given = 1;
valid = 1;
continue;
}
if (strncasecmp(key, KEY_NAME, sizeof(KEY_NAME)-1) == 0) {
attr = get_key_attribute(key + sizeof(KEY_NAME)-1);
if (attr != NULL) {
if (strstr(attr, OPTION_PARTITIONS) != NULL) {
dbg("creation of partition nodes requested");
rule.partitions = DEFAULT_PARTITIONS_COUNT;
}
if (strstr(attr, OPTION_IGNORE_REMOVE) != NULL) {
dbg("remove event should be ignored");
rule.ignore_remove = 1;
}
}
rule.name_operation = operation;
strlcpy(rule.name, value, sizeof(rule.name));
valid = 1;
continue;
}
if (strcasecmp(key, KEY_SYMLINK) == 0) {
strlcpy(rule.symlink, value, sizeof(rule.symlink));
rule.symlink_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_OWNER) == 0) {
strlcpy(rule.owner, value, sizeof(rule.owner));
rule.owner_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_GROUP) == 0) {
strlcpy(rule.group, value, sizeof(rule.group));
rule.group_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_MODE) == 0) {
rule.mode = strtol(value, NULL, 8);
rule.mode_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_RUN) == 0) {
strlcpy(rule.run, value, sizeof(rule.run));
rule.run_operation = operation;
valid = 1;
continue;
}
if (strcasecmp(key, KEY_OPTIONS) == 0) {
if (strstr(value, OPTION_LAST_RULE) != NULL) {
dbg("last rule to be applied");
rule.last_rule = 1;
}
if (strstr(value, OPTION_IGNORE_DEVICE) != NULL) {
dbg("device should be ignored");
rule.ignore_device = 1;
}
if (strstr(value, OPTION_IGNORE_REMOVE) != NULL) {
dbg("remove event should be ignored");
rule.ignore_remove = 1;
}
if (strstr(value, OPTION_PARTITIONS) != NULL) {
dbg("creation of partition nodes requested");
rule.partitions = DEFAULT_PARTITIONS_COUNT;
}
valid = 1;
continue;
}
err("unknown key '%s'", key);
goto error;
}
/* skip line if not any valid key was found */
if (!valid)
goto error;
if ((rule.result[0] != '\0') && (program_given == 0)) {
info(KEY_RESULT " is only useful when " KEY_PROGRAM " is called in any rule before");
goto error;
}
rule.config_line = lineno;
strlcpy(rule.config_file, filename, sizeof(rule.config_file));
retval = add_rule_to_list(&rule);
if (retval) {
dbg("add_rule_to_list returned with error %d", retval);
continue;
error:
err("parse error %s, line %d:%d, rule skipped",
filename, lineno, (int) (linepos - line));
}
}
file_unmap(buf, bufsize);
return retval;
}
static int rules_map(const char *filename)
{
char *buf;
size_t size;
if (file_map(filename, &buf, &size))
return -1;
if (size == 0)
return -1;
rules_array = (struct udev_rule *) buf;
rules_array_size = size;
rules_count = size / sizeof(struct udev_rule);
dbg("found %zi compiled rules", rules_count);
return 0;
}
int udev_rules_init(void)
{
char comp[PATH_SIZE];
struct stat stats;
int retval;
strlcpy(comp, udev_rules_filename, sizeof(comp));
strlcat(comp, ".compiled", sizeof(comp));
if (stat(comp, &stats) == 0) {
dbg("parse compiled rules '%s'", comp);
return rules_map(comp);
}
if (stat(udev_rules_filename, &stats) != 0)
return -1;
if ((stats.st_mode & S_IFMT) != S_IFDIR) {
dbg("parse single rules file '%s'", udev_rules_filename);
retval = rules_parse(udev_rules_filename);
} else {
struct name_entry *name_loop, *name_tmp;
LIST_HEAD(name_list);
dbg("parse rules directory '%s'", udev_rules_filename);
retval = add_matching_files(&name_list, udev_rules_filename, RULEFILE_SUFFIX);
list_for_each_entry_safe(name_loop, name_tmp, &name_list, node) {
rules_parse(name_loop->name);
list_del(&name_loop->node);
}
}
return retval;
}
void udev_rules_close(void)
{
struct udev_rule *rule;
struct udev_rule *temp_rule;
if (rules_array)
file_unmap(rules_array, rules_array_size);
else
list_for_each_entry_safe(rule, temp_rule, &rules_list, node) {
list_del(&rule->node);
free(rule);
}
}