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Systemd/namedev.c
kay.sievers@vrfy.org 882af735ec [PATCH] remove PLACE key match 
ID should do the same, cause we walk up the chain of devices on the
physical device and can match for the name of every device there with
the ID key.
2005-04-26 23:51:00 -07:00

779 lines
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/*
* namedev.c
*
* Userspace devfs
*
* Copyright (C) 2003 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 <fcntl.h>
#include <ctype.h>
#include <unistd.h>
#include <errno.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include "libsysfs/sysfs/libsysfs.h"
#include "list.h"
#include "udev_libc_wrapper.h"
#include "udev.h"
#include "udev_utils.h"
#include "udev_version.h"
#include "logging.h"
#include "namedev.h"
#include "udev_db.h"
static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, char *attr);
/* compare string with pattern (supports * ? [0-9] [!A-Z]) */
static int strcmp_pattern(const char *p, const char *s)
{
if (s[0] == '\0') {
while (p[0] == '*')
p++;
return (p[0] != '\0');
}
switch (p[0]) {
case '[':
{
int not = 0;
p++;
if (p[0] == '!') {
not = 1;
p++;
}
while ((p[0] != '\0') && (p[0] != ']')) {
int match = 0;
if (p[1] == '-') {
if ((s[0] >= p[0]) && (s[0] <= p[2]))
match = 1;
p += 3;
} else {
match = (p[0] == s[0]);
p++;
}
if (match ^ not) {
while ((p[0] != '\0') && (p[0] != ']'))
p++;
if (p[0] == ']')
return strcmp_pattern(p+1, s+1);
}
}
}
break;
case '*':
if (strcmp_pattern(p, s+1))
return strcmp_pattern(p+1, s);
return 0;
case '\0':
if (s[0] == '\0') {
return 0;
}
break;
default:
if ((p[0] == s[0]) || (p[0] == '?'))
return strcmp_pattern(p+1, s+1);
break;
}
return 1;
}
/* extract possible {attr} and move str behind it */
static char *get_format_attribute(char **str)
{
char *pos;
char *attr = NULL;
if (*str[0] == '{') {
pos = strchr(*str, '}');
if (pos == NULL) {
dbg("missing closing brace for format");
return NULL;
}
pos[0] = '\0';
attr = *str+1;
*str = pos+1;
dbg("attribute='%s', str='%s'", attr, *str);
}
return attr;
}
/* extract possible format length and move str behind it*/
static int get_format_len(char **str)
{
int num;
char *tail;
if (isdigit(*str[0])) {
num = (int) strtoul(*str, &tail, 10);
if (num > 0) {
*str = tail;
dbg("format length=%i", num);
return num;
} else {
dbg("format parsing error '%s'", *str);
}
}
return -1;
}
/** Finds the lowest positive N such that <name>N isn't present in
* $(udevroot) either as a file or a symlink.
*
* @param name Name to check for
* @return 0 if <name> didn't exist and N otherwise.
*/
static int find_free_number(struct udevice *udev, const char *name)
{
char devpath[PATH_SIZE];
char filename[PATH_SIZE];
int num = 0;
strlcpy(filename, name, sizeof(filename));
while (1) {
dbg("look for existing node '%s'", filename);
if (udev_db_search_name(devpath, sizeof(devpath), filename) != 0) {
dbg("free num=%d", num);
return num;
}
num++;
if (num > 1000) {
info("find_free_number gone crazy (num=%d), aborted", num);
return -1;
}
snprintf(filename, sizeof(filename), "%s%d", name, num);
filename[sizeof(filename)-1] = '\0';
}
}
static void apply_format(struct udevice *udev, char *string, size_t maxsize,
struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
{
char temp[PATH_SIZE];
char temp2[PATH_SIZE];
char *tail, *pos, *cpos, *attr, *rest;
int len;
int i;
char c;
struct sysfs_attribute *tmpattr;
unsigned int next_free_number;
struct sysfs_class_device *class_dev_parent;
pos = string;
while (1) {
pos = strchr(pos, '%');
if (pos == NULL)
break;
pos[0] = '\0';
tail = pos+1;
len = get_format_len(&tail);
c = tail[0];
strlcpy(temp, tail+1, sizeof(temp));
tail = temp;
dbg("format=%c, string='%s', tail='%s'",c , string, tail);
attr = get_format_attribute(&tail);
switch (c) {
case 'p':
strlcat(string, udev->devpath, maxsize);
dbg("substitute kernel name '%s'", udev->kernel_name);
break;
case 'b':
strlcat(string, udev->bus_id, maxsize);
dbg("substitute bus_id '%s'", udev->bus_id);
break;
case 'k':
strlcat(string, udev->kernel_name, maxsize);
dbg("substitute kernel name '%s'", udev->kernel_name);
break;
case 'n':
strlcat(string, udev->kernel_number, maxsize);
dbg("substitute kernel number '%s'", udev->kernel_number);
break;
case 'm':
sprintf(temp2, "%d", minor(udev->devt));
strlcat(string, temp2, maxsize);
dbg("substitute minor number '%s'", temp2);
break;
case 'M':
sprintf(temp2, "%d", major(udev->devt));
strlcat(string, temp2, maxsize);
dbg("substitute major number '%s'", temp2);
break;
case 'c':
if (udev->program_result[0] == '\0')
break;
/* get part part of the result string */
i = 0;
if (attr != NULL)
i = strtoul(attr, &rest, 10);
if (i > 0) {
dbg("request part #%d of result string", i);
cpos = udev->program_result;
while (--i) {
while (cpos[0] != '\0' && !isspace(cpos[0]))
cpos++;
while (isspace(cpos[0]))
cpos++;
}
if (i > 0) {
dbg("requested part of result string not found");
break;
}
strlcpy(temp2, cpos, sizeof(temp2));
/* %{2+}c copies the whole string from the second part on */
if (rest[0] != '+') {
cpos = strchr(temp2, ' ');
if (cpos)
cpos[0] = '\0';
}
strlcat(string, temp2, maxsize);
dbg("substitute part of result string '%s'", temp2);
} else {
strlcat(string, udev->program_result, maxsize);
dbg("substitute result string '%s'", udev->program_result);
}
break;
case 's':
if (!class_dev)
break;
if (attr == NULL) {
dbg("missing attribute");
break;
}
tmpattr = find_sysfs_attribute(class_dev, sysfs_device, attr);
if (tmpattr == NULL) {
dbg("sysfa attribute '%s' not found", attr);
break;
}
/* strip trailing whitespace of matching value */
if (isspace(tmpattr->value[strlen(tmpattr->value)-1])) {
i = len = strlen(tmpattr->value);
while (i > 0 && isspace(tmpattr->value[i-1]))
i--;
if (i < len) {
tmpattr->value[i] = '\0';
dbg("remove %i trailing whitespace chars from '%s'",
len - i, tmpattr->value);
}
}
strlcat(string, tmpattr->value, maxsize);
dbg("substitute sysfs value '%s'", tmpattr->value);
break;
case '%':
strlcat(string, "%", maxsize);
pos++;
break;
case 'e':
next_free_number = find_free_number(udev, string);
if (next_free_number > 0) {
sprintf(temp2, "%d", next_free_number);
strlcat(string, temp2, maxsize);
}
break;
case 'P':
if (!class_dev)
break;
class_dev_parent = sysfs_get_classdev_parent(class_dev);
if (class_dev_parent != NULL) {
struct udevice udev_parent;
dbg("found parent '%s', get the node name", class_dev_parent->path);
udev_init_device(&udev_parent, NULL, NULL);
/* lookup the name in the udev_db with the DEVPATH of the parent */
if (udev_db_get_device(&udev_parent, &class_dev_parent->path[strlen(sysfs_path)]) == 0) {
strlcat(string, udev_parent.name, maxsize);
dbg("substitute parent node name'%s'", udev_parent.name);
} else
dbg("parent not found in database");
udev_cleanup_device(&udev_parent);
}
break;
case 'N':
if (udev->tmp_node[0] == '\0') {
dbg("create temporary device node for callout");
snprintf(udev->tmp_node, sizeof(udev->tmp_node), "%s/.tmp-%u-%u",
udev_root, major(udev->devt), minor(udev->devt));
udev->tmp_node[sizeof(udev->tmp_node)-1] = '\0';
udev_make_node(udev, udev->tmp_node, udev->devt, 0600, 0, 0);
}
strlcat(string, udev->tmp_node, maxsize);
dbg("substitute temporary device node name '%s'", udev->tmp_node);
break;
case 'r':
strlcat(string, udev_root, maxsize);
dbg("substitute udev_root '%s'", udev_root);
break;
default:
dbg("unknown substitution type '%%%c'", c);
break;
}
/* truncate to specified length */
if (len > 0)
pos[len] = '\0';
strlcat(string, tail, maxsize);
}
}
static int execute_program(struct udevice *udev, const char *path, char *value, int len)
{
int retval;
int count;
int status;
int fds[2];
pid_t pid;
char *pos;
char arg[PATH_SIZE];
char *argv[(sizeof(arg) / 2) + 1];
int i;
strlcpy(arg, path, sizeof(arg));
i = 0;
if (strchr(path, ' ')) {
pos = arg;
while (pos != NULL) {
if (pos[0] == '\'') {
/* don't separate if in apostrophes */
pos++;
argv[i] = strsep(&pos, "\'");
while (pos && pos[0] == ' ')
pos++;
} else {
argv[i] = strsep(&pos, " ");
}
dbg("arg[%i] '%s'", i, argv[i]);
i++;
}
argv[i] = NULL;
dbg("execute '%s' with parsed arguments", arg);
} else {
argv[0] = arg;
argv[1] = udev->subsystem;
argv[2] = NULL;
dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]);
}
retval = pipe(fds);
if (retval != 0) {
dbg("pipe failed");
return -1;
}
pid = fork();
switch(pid) {
case 0:
/* child */
/* dup2 write side of pipe to STDOUT */
dup2(fds[1], STDOUT_FILENO);
retval = execv(arg, argv);
info(FIELD_PROGRAM " execution of '%s' failed", path);
exit(1);
case -1:
dbg("fork failed");
return -1;
default:
/* parent reads from fds[0] */
close(fds[1]);
retval = 0;
i = 0;
while (1) {
count = read(fds[0], value + i, len - i-1);
if (count <= 0)
break;
i += count;
if (i >= len-1) {
dbg("result len %d too short", len);
retval = -1;
break;
}
}
if (count < 0) {
dbg("read failed with '%s'", strerror(errno));
retval = -1;
}
if (i > 0 && value[i-1] == '\n')
i--;
value[i] = '\0';
dbg("result is '%s'", value);
close(fds[0]);
waitpid(pid, &status, 0);
if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
dbg("exec program status 0x%x", status);
retval = -1;
}
}
return retval;
}
static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, char *attr)
{
struct sysfs_attribute *tmpattr = NULL;
char *c;
dbg("look for device attribute '%s'", attr);
/* try to find the attribute in the class device directory */
tmpattr = sysfs_get_classdev_attr(class_dev, attr);
if (tmpattr)
goto attr_found;
/* look in the class device directory if present */
if (sysfs_device) {
tmpattr = sysfs_get_device_attr(sysfs_device, attr);
if (tmpattr)
goto attr_found;
}
return NULL;
attr_found:
c = strchr(tmpattr->value, '\n');
if (c != NULL)
c[0] = '\0';
dbg("found attribute '%s'", tmpattr->path);
return tmpattr;
}
static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct sysfs_pair *pair)
{
struct sysfs_attribute *tmpattr;
int i;
int len;
if ((pair == NULL) || (pair->file[0] == '\0') || (pair->value == '\0'))
return -ENODEV;
tmpattr = find_sysfs_attribute(class_dev, sysfs_device, pair->file);
if (tmpattr == NULL)
return -ENODEV;
/* strip trailing whitespace of value, if not asked to match for it */
if (! isspace(pair->value[strlen(pair->value)-1])) {
i = len = strlen(tmpattr->value);
while (i > 0 && isspace(tmpattr->value[i-1]))
i--;
if (i < len) {
tmpattr->value[i] = '\0';
dbg("remove %i trailing whitespace chars from '%s'",
len - i, tmpattr->value);
}
}
dbg("compare attribute '%s' value '%s' with '%s'",
pair->file, tmpattr->value, pair->value);
if (strcmp_pattern(pair->value, tmpattr->value) != 0)
return -ENODEV;
dbg("found matching attribute '%s' with value '%s'",
pair->file, pair->value);
return 0;
}
static int match_sysfs_pairs(struct config_device *dev, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
{
struct sysfs_pair *pair;
int i;
for (i = 0; i < MAX_SYSFS_PAIRS; ++i) {
pair = &dev->sysfs_pair[i];
if ((pair->file[0] == '\0') || (pair->value[0] == '\0'))
break;
if (compare_sysfs_attribute(class_dev, sysfs_device, pair) != 0) {
dbg("sysfs attribute doesn't match");
return -ENODEV;
}
}
return 0;
}
static int match_id(struct config_device *dev, struct sysfs_device *sysfs_device)
{
char path[PATH_SIZE];
char *temp;
strlcpy(path, sysfs_device->path, sizeof(path));
temp = strrchr(path, '/');
temp++;
dbg("search '%s' in '%s', path='%s'", dev->id, temp, path);
if (strcmp_pattern(dev->id, temp) != 0)
return -ENODEV;
return 0;
}
static int match_rule(struct udevice *udev, struct config_device *dev,
struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
{
if (dev->kernel[0] != '\0') {
dbg("check for " FIELD_KERNEL " dev->kernel='%s' class_dev->name='%s'",
dev->kernel, class_dev->name);
if (strcmp_pattern(dev->kernel, class_dev->name) != 0) {
dbg(FIELD_KERNEL " is not matching");
goto exit;
}
dbg(FIELD_KERNEL " matches");
}
if (dev->subsystem[0] != '\0') {
dbg("check for " FIELD_SUBSYSTEM " dev->subsystem='%s' class_dev->name='%s'",
dev->subsystem, class_dev->name);
if (strcmp_pattern(dev->subsystem, udev->subsystem) != 0) {
dbg(FIELD_SUBSYSTEM " is not matching");
goto exit;
}
dbg(FIELD_SUBSYSTEM " matches");
}
/* walk up the chain of physical devices and find a match */
while (1) {
/* check for matching driver */
if (dev->driver[0] != '\0') {
if (sysfs_device == NULL) {
dbg("device has no sysfs_device");
goto try_parent;
}
dbg("check for " FIELD_DRIVER " dev->driver='%s' sysfs_device->driver_name='%s'",
dev->driver, sysfs_device->driver_name);
if (strcmp_pattern(dev->driver, sysfs_device->driver_name) != 0) {
dbg(FIELD_DRIVER " is not matching");
goto try_parent;
}
dbg(FIELD_DRIVER " matches");
}
/* check for matching bus value */
if (dev->bus[0] != '\0') {
if (sysfs_device == NULL) {
dbg("device has no sysfs_device");
goto try_parent;
}
dbg("check for " FIELD_BUS " dev->bus='%s' sysfs_device->bus='%s'",
dev->bus, sysfs_device->bus);
if (strcmp_pattern(dev->bus, sysfs_device->bus) != 0) {
dbg(FIELD_BUS " is not matching");
goto try_parent;
}
dbg(FIELD_BUS " matches");
}
/* check for matching bus id */
if (dev->id[0] != '\0') {
if (sysfs_device == NULL) {
dbg("device has no sysfs_device");
goto try_parent;
}
dbg("check " FIELD_ID);
if (match_id(dev, sysfs_device) != 0) {
dbg(FIELD_ID " is not matching");
goto try_parent;
}
dbg(FIELD_ID " matches");
}
/* check for matching sysfs pairs */
if (dev->sysfs_pair[0].file[0] != '\0') {
dbg("check " FIELD_SYSFS " pairs");
if (match_sysfs_pairs(dev, class_dev, sysfs_device) != 0) {
dbg(FIELD_SYSFS " is not matching");
goto try_parent;
}
dbg(FIELD_SYSFS " matches");
}
/* found matching physical device */
break;
try_parent:
dbg("try parent sysfs device");
sysfs_device = sysfs_get_device_parent(sysfs_device);
if (sysfs_device == NULL)
goto exit;
dbg("sysfs_device->path='%s'", sysfs_device->path);
dbg("sysfs_device->bus_id='%s'", sysfs_device->bus_id);
}
/* execute external program */
if (dev->program[0] != '\0') {
char program[PATH_SIZE];
dbg("check " FIELD_PROGRAM);
strlcpy(program, dev->program, sizeof(program));
apply_format(udev, program, sizeof(program), class_dev, sysfs_device);
if (execute_program(udev, program, udev->program_result, sizeof(udev->program_result)) != 0) {
dbg(FIELD_PROGRAM " returned nonzero");
goto try_parent;
}
dbg(FIELD_PROGRAM " returned successful");
}
/* check for matching result of external program */
if (dev->result[0] != '\0') {
dbg("check for " FIELD_RESULT " dev->result='%s', udev->program_result='%s'",
dev->result, udev->program_result);
if (strcmp_pattern(dev->result, udev->program_result) != 0) {
dbg(FIELD_RESULT " is not matching");
goto try_parent;
}
dbg(FIELD_RESULT " matches");
}
/* rule matches */
return 0;
exit:
return -1;
}
int namedev_name_device(struct udevice *udev, struct sysfs_class_device *class_dev)
{
struct sysfs_class_device *class_dev_parent;
struct sysfs_device *sysfs_device = NULL;
struct config_device *dev;
dbg("class_dev->name='%s'", class_dev->name);
/* Figure out where the "device"-symlink is at. For char devices this will
* always be in the class_dev->path. On block devices, only the main block
* device will have the device symlink in it's path. All partition devices
* need to look at the symlink in its parent directory.
*/
class_dev_parent = sysfs_get_classdev_parent(class_dev);
if (class_dev_parent != NULL) {
dbg("given class device has a parent, use this instead");
sysfs_device = sysfs_get_classdev_device(class_dev_parent);
} else {
sysfs_device = sysfs_get_classdev_device(class_dev);
}
if (sysfs_device) {
dbg("found devices device: path='%s', bus_id='%s', bus='%s'",
sysfs_device->path, sysfs_device->bus_id, sysfs_device->bus);
strlcpy(udev->bus_id, sysfs_device->bus_id, sizeof(udev->bus_id));
}
dbg("udev->kernel_name='%s'", udev->kernel_name);
/* look for a matching rule to apply */
list_for_each_entry(dev, &config_device_list, node) {
dbg("process rule");
if (match_rule(udev, dev, class_dev, sysfs_device) == 0) {
/* apply options */
if (dev->ignore_device) {
info("configured rule in '%s[%i]' applied, '%s' is ignored",
dev->config_file, dev->config_line, udev->kernel_name);
return -1;
}
if (dev->ignore_remove) {
udev->ignore_remove = 1;
dbg_parse("remove event should be ignored");
}
/* apply all_partitions option only at a main block device */
if (dev->partitions && udev->type == BLOCK && udev->kernel_number[0] == '\0') {
udev->partitions = dev->partitions;
dbg("creation of partition nodes requested");
}
/* apply permissions */
if (dev->mode != 0000) {
udev->mode = dev->mode;
dbg("applied mode=%#o to '%s'", udev->mode, udev->kernel_name);
}
if (dev->owner[0] != '\0') {
strlcpy(udev->owner, dev->owner, sizeof(udev->owner));
apply_format(udev, udev->owner, sizeof(udev->owner), class_dev, sysfs_device);
dbg("applied owner='%s' to '%s'", udev->owner, udev->kernel_name);
}
if (dev->group[0] != '\0') {
strlcpy(udev->group, dev->group, sizeof(udev->group));
apply_format(udev, udev->group, sizeof(udev->group), class_dev, sysfs_device);
dbg("applied group='%s' to '%s'", udev->group, udev->kernel_name);
}
/* collect symlinks */
if (dev->symlink[0] != '\0') {
char temp[PATH_SIZE];
char *pos, *next;
info("configured rule in '%s[%i]' applied, added symlink '%s'",
dev->config_file, dev->config_line, dev->symlink);
strlcpy(temp, dev->symlink, sizeof(temp));
apply_format(udev, temp, sizeof(temp), class_dev, sysfs_device);
/* add multiple symlinks separated by spaces */
pos = temp;
next = strchr(temp, ' ');
while (next) {
next[0] = '\0';
dbg("add symlink '%s'", pos);
name_list_add(&udev->symlink_list, pos, 0);
pos = &next[1];
next = strchr(pos, ' ');
}
dbg("add symlink '%s'", pos);
name_list_add(&udev->symlink_list, pos, 0);
}
/* rule matches */
if (dev->name[0] != '\0') {
info("configured rule in '%s[%i]' applied, '%s' becomes '%s'",
dev->config_file, dev->config_line, udev->kernel_name, dev->name);
strlcpy(udev->name, dev->name, sizeof(udev->name));
apply_format(udev, udev->name, sizeof(udev->name), class_dev, sysfs_device);
strlcpy(udev->config_file, dev->config_file, sizeof(udev->config_file));
udev->config_line = dev->config_line;
if (udev->type != NET)
dbg("name, '%s' is going to have owner='%s', group='%s', mode=%#o partitions=%i",
udev->name, udev->owner, udev->group, udev->mode, udev->partitions);
break;
}
}
}
if (udev->name[0] == '\0') {
/* no rule matched, so we use the kernel name */
strlcpy(udev->name, udev->kernel_name, sizeof(udev->name));
dbg("no rule found, use kernel name '%s'", udev->name);
}
if (udev->tmp_node[0] != '\0') {
dbg("removing temporary device node");
unlink_secure(udev->tmp_node);
udev->tmp_node[0] = '\0';
}
return 0;
}
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