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systemd-stable/namedev.c

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/*
* namedev.c
*
* Userspace devfs
*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
*
*
* 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.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 filename[NAME_SIZE];
int num = 0;
struct udevice db_udev;
strfieldcpy(filename, name);
while (1) {
dbg("look for existing node '%s'", filename);
memset(&db_udev, 0x00, sizeof(struct udevice));
if (udev_db_get_device_byname(&db_udev, 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, NAME_SIZE, "%s%d", name, num);
filename[NAME_SIZE-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[NAME_SIZE];
char temp2[NAME_SIZE];
char *tail;
char *pos;
char *attr;
int len;
int i;
char c;
char *spos;
char *rest;
int slen;
struct sysfs_attribute *tmpattr;
unsigned int next_free_number;
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];
strfieldcpy(temp, tail+1);
tail = temp;
dbg("format=%c, string='%s', tail='%s'",c , string, tail);
attr = get_format_attribute(&tail);
switch (c) {
case 'b':
if (strlen(udev->bus_id) == 0)
break;
strfieldcatmax(string, udev->bus_id, maxsize);
dbg("substitute bus_id '%s'", udev->bus_id);
break;
case 'k':
if (strlen(udev->kernel_name) == 0)
break;
strfieldcatmax(string, udev->kernel_name, maxsize);
dbg("substitute kernel name '%s'", udev->kernel_name);
break;
case 'n':
if (strlen(udev->kernel_number) == 0)
break;
strfieldcatmax(string, udev->kernel_number, maxsize);
dbg("substitute kernel number '%s'", udev->kernel_number);
break;
case 'm':
strintcatmax(string, udev->minor, maxsize);
dbg("substitute minor number '%u'", udev->minor);
break;
case 'M':
strintcatmax(string, udev->major, maxsize);
dbg("substitute major number '%u'", udev->major);
break;
case 'c':
if (strlen(udev->program_result) == 0)
break;
/* get part part of the result string */
i = 0;
if (attr != NULL)
i = strtoul(attr, &rest, 10);
if (i > 0) {
foreach_strpart(udev->program_result, " \n\r", spos, slen) {
i--;
if (i == 0)
break;
}
if (i > 0) {
dbg("requested part of result string not found");
break;
}
if (rest[0] == '+')
strfieldcpy(temp2, spos);
else
strfieldcpymax(temp2, spos, slen+1);
strfieldcatmax(string, temp2, maxsize);
dbg("substitute part of result string '%s'", temp2);
} else {
strfieldcatmax(string, udev->program_result, maxsize);
dbg("substitute result string '%s'", udev->program_result);
}
break;
case 's':
if (attr != NULL) {
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);
}
}
strfieldcatmax(string, tmpattr->value, maxsize);
dbg("substitute sysfs value '%s'", tmpattr->value);
} else {
dbg("missing attribute");
}
break;
case '%':
strfieldcatmax(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);
strfieldcatmax(string, temp2, maxsize);
}
break;
default:
dbg("unknown substitution type '%%%c'", c);
break;
}
/* truncate to specified length */
if (len > 0)
pos[len] = '\0';
strfieldcatmax(string, tail, maxsize);
}
}
static void fix_kernel_name(struct udevice *udev)
{
char *temp = udev->kernel_name;
while (*temp != 0x00) {
/* Some block devices have a ! in their name,
* we need to change that to / */
if (*temp == '!')
*temp = '/';
++temp;
}
}
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[PROGRAM_SIZE];
char *argv[(PROGRAM_SIZE / 2) + 1];
int i;
strfieldcpy(arg, path);
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_class_device *class_dev, struct sysfs_device *sysfs_device)
{
char path[SYSFS_PATH_MAX];
char *temp = NULL;
/* we have to have a sysfs device for ID to work */
if (!sysfs_device)
return -ENODEV;
strfieldcpy(path, sysfs_device->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;
else
return 0;
}
static int match_place(struct config_device *dev, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
{
char path[SYSFS_PATH_MAX];
int found;
char *temp = NULL;
/* we have to have a sysfs device for PLACE to work */
if (!sysfs_device)
return -ENODEV;
found = 0;
strfieldcpy(path, sysfs_device->path);
temp = strrchr(path, '/');
dbg("search '%s' in '%s', path='%s'", dev->place, temp, path);
if (strstr(temp, dev->place) != NULL) {
found = 1;
} else {
*temp = 0x00;
temp = strrchr(path, '/');
dbg("search '%s' in '%s', path='%s'", dev->place, temp, path);
if (strstr(temp, dev->place) != NULL)
found = 1;
}
if (!found) {
dbg("place doesn't match");
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)
{
while (1) {
/* check for matching bus value */
if (dev->bus[0] != '\0') {
if (sysfs_device == NULL) {
dbg("device has no bus");
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;
} else {
dbg(FIELD_BUS " matches");
}
}
/* check for matching kernel name */
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 try_parent;
} else {
dbg(FIELD_KERNEL " matches");
}
}
/* check for matching subsystem */
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 try_parent;
} else {
dbg(FIELD_SUBSYSTEM " matches");
}
}
/* check for matching driver */
if (dev->driver[0] != '\0') {
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;
} else {
dbg(FIELD_DRIVER " matches");
}
}
/* check for matching bus id */
if (dev->id[0] != '\0') {
dbg("check " FIELD_ID);
if (match_id(dev, class_dev, sysfs_device) != 0) {
dbg(FIELD_ID " is not matching");
goto try_parent;
} else {
dbg(FIELD_ID " matches");
}
}
/* check for matching place of device */
if (dev->place[0] != '\0') {
dbg("check " FIELD_PLACE);
if (match_place(dev, class_dev, sysfs_device) != 0) {
dbg(FIELD_PLACE " is not matching");
goto try_parent;
} else {
dbg(FIELD_PLACE " 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;
} else {
dbg(FIELD_SYSFS " matches");
}
}
/* execute external program */
if (dev->program[0] != '\0') {
char program[PROGRAM_SIZE];
dbg("check " FIELD_PROGRAM);
strfieldcpy(program, dev->program);
apply_format(udev, program, sizeof(program), class_dev, sysfs_device);
if (execute_program(udev, program, udev->program_result, NAME_SIZE) != 0) {
dbg(FIELD_PROGRAM " returned nonzero");
goto try_parent;
} else {
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;
} else {
dbg(FIELD_RESULT " matches");
}
}
/* Yeah, we matched! */
return 0;
try_parent:
dbg("try parent sysfs device");
sysfs_device = sysfs_get_device_parent(sysfs_device);
if (sysfs_device == NULL)
return -ENODEV;
dbg("sysfs_device->path='%s'", sysfs_device->path);
dbg("sysfs_device->bus_id='%s'", sysfs_device->bus_id);
}
}
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;
char *pos;
udev->mode = 0;
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);
strfieldcpy(udev->bus_id, sysfs_device->bus_id);
}
strfieldcpy(udev->kernel_name, class_dev->name);
fix_kernel_name(udev);
dbg("udev->kernel_name = '%s'", udev->kernel_name);
/* get kernel number */
pos = class_dev->name + strlen(class_dev->name);
while (isdigit(*(pos-1)))
pos--;
strfieldcpy(udev->kernel_number, pos);
dbg("kernel_number='%s'", udev->kernel_number);
/* 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) {
/* empty name and symlink will not create any node */
if (dev->name[0] == '\0' && dev->symlink[0] == '\0') {
info("configured rule in '%s' at line %i applied, '%s' is ignored",
dev->config_file, dev->config_line, udev->kernel_name);
return -1;
}
/* collect symlinks for the final matching rule */
if (dev->symlink[0] != '\0') {
char temp[NAME_SIZE];
info("configured rule in '%s' at line %i applied, added symlink '%s'",
dev->config_file, dev->config_line, dev->symlink);
strfieldcpy(temp, dev->symlink);
apply_format(udev, temp, sizeof(temp), class_dev, sysfs_device);
if (udev->symlink[0] != '\0')
strfieldcat(udev->symlink, " ");
strfieldcat(udev->symlink, temp);
}
/* rule matches */
if (dev->name[0] != '\0') {
/* apply all_partitions flag only at a main block device */
if (dev->partitions > 0 &&
(udev->type != 'b' || udev->kernel_number[0] != '\0'))
continue;
info("configured rule in '%s' at line %i applied, '%s' becomes '%s'",
dev->config_file, dev->config_line, udev->kernel_name, dev->name);
strfieldcpy(udev->name, dev->name);
apply_format(udev, udev->name, sizeof(udev->name), class_dev, sysfs_device);
strfieldcpy(udev->config_file, dev->config_file);
udev->config_line = dev->config_line;
udev->ignore_remove = dev->ignore_remove;
if (udev->type == 'n')
goto exit;
udev->partitions = dev->partitions;
udev->mode = dev->mode;
strfieldcpy(udev->owner, dev->owner);
apply_format(udev, udev->owner, sizeof(udev->owner), class_dev, sysfs_device);
strfieldcpy(udev->group, dev->group);
apply_format(udev, udev->group, sizeof(udev->group), class_dev, sysfs_device);
goto perms;
}
}
}
/* no rule matched, so we use the kernel name */
strfieldcpy(udev->name, udev->kernel_name);
if (udev->type == 'n')
goto exit;
perms:
/* apply default permissions to empty fields */
if (udev->mode == 0000)
udev->mode = default_mode;
if (udev->owner[0] == '\0')
strfieldcpy(udev->owner, default_owner);
if (udev->group[0] == '\0')
strfieldcpy(udev->group, default_group);
dbg("name, '%s' is going to have owner='%s', group='%s', mode = %#o",
udev->name, udev->owner, udev->group, udev->mode);
exit:
return 0;
}
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