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Systemd/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 "list.h"
#include "udev.h"
#include "udev_version.h"
#include "namedev.h"
#include "libsysfs/libsysfs.h"
#include "klibc_fixups.h"
LIST_HEAD(config_device_list);
LIST_HEAD(perm_device_list);
/* compare string with pattern (supports * ? [0-9] [!A-Z]) */
static int strcmp_pattern(const char *p, const char *s)
{
if (*s == '\0') {
while (*p == '*')
p++;
return (*p != '\0');
}
switch (*p) {
case '[':
{
int not = 0;
p++;
if (*p == '!') {
not = 1;
p++;
}
while (*p && (*p != ']')) {
int match = 0;
if (p[1] == '-') {
if ((*s >= *p) && (*s <= p[2]))
match = 1;
p += 3;
} else {
match = (*p == *s);
p++;
}
if (match ^ not) {
while (*p && (*p != ']'))
p++;
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') {
return 0;
}
break;
default:
if ((*p == *s) || (*p == '?'))
return strcmp_pattern(p+1, s+1);
break;
}
return 1;
}
#define copy_var(a, b, var) \
if (b->var) \
a->var = b->var;
#define copy_string(a, b, var) \
if (strlen(b->var)) \
strcpy(a->var, b->var);
int add_perm_dev(struct perm_device *new_dev)
{
struct list_head *tmp;
struct perm_device *tmp_dev;
/* update the values if we already have the device */
list_for_each(tmp, &perm_device_list) {
struct perm_device *dev = list_entry(tmp, struct perm_device, node);
if (strcmp_pattern(new_dev->name, dev->name))
continue;
copy_var(dev, new_dev, mode);
copy_string(dev, new_dev, owner);
copy_string(dev, new_dev, group);
return 0;
}
/* not found, add new structure to the perm list */
tmp_dev = malloc(sizeof(*tmp_dev));
if (!tmp_dev)
return -ENOMEM;
memcpy(tmp_dev, new_dev, sizeof(*tmp_dev));
list_add_tail(&tmp_dev->node, &perm_device_list);
//dump_perm_dev(tmp_dev);
return 0;
}
static struct perm_device *find_perm(char *name)
{
struct list_head *tmp;
struct perm_device *perm = NULL;
list_for_each(tmp, &perm_device_list) {
perm = list_entry(tmp, struct perm_device, node);
if (strcmp_pattern(perm->name, name))
continue;
return perm;
}
return NULL;
}
static mode_t get_default_mode(struct sysfs_class_device *class_dev)
{
mode_t mode = 0600; /* default to owner rw only */
if (strlen(default_mode_str) != 0) {
mode = strtol(default_mode_str, NULL, 8);
}
return mode;
}
static void apply_format(struct udevice *udev, unsigned char *string)
{
char name[NAME_SIZE];
char temp[NAME_SIZE];
char *tail;
char *pos;
char *pos2;
char *pos3;
int num;
while (1) {
num = 0;
pos = strchr(string, '%');
if (pos) {
*pos = '\0';
tail = pos+1;
if (isdigit(tail[0])) {
num = (int) strtoul(&pos[1], &tail, 10);
if (tail == NULL) {
dbg("format parsing error '%s'", pos+1);
break;
}
}
strfieldcpy(name, tail+1);
switch (tail[0]) {
case 'b':
if (strlen(udev->bus_id) == 0)
break;
strcat(pos, udev->bus_id);
dbg("substitute bus_id '%s'", udev->bus_id);
break;
case 'k':
if (strlen(udev->kernel_name) == 0)
break;
strcat(pos, udev->kernel_name);
dbg("substitute kernel name '%s'", udev->kernel_name);
break;
case 'n':
if (strlen(udev->kernel_number) == 0)
break;
strcat(pos, udev->kernel_number);
dbg("substitute kernel number '%s'", udev->kernel_number);
break;
case 'D':
if (strlen(udev->kernel_number) == 0) {
strcat(pos, "disc");
dbg("substitute devfs disc");
break;
}
strcat(pos, "part");
strcat(pos, udev->kernel_number);
dbg("substitute devfs part '%s'", udev->kernel_number);
break;
case 'm':
sprintf(pos, "%u", udev->minor);
dbg("substitute minor number '%u'", udev->minor);
break;
case 'M':
sprintf(pos, "%u", udev->major);
dbg("substitute major number '%u'", udev->major);
break;
case 'c':
if (strlen(udev->callout_value) == 0)
break;
if (num) {
/* get part of return string */
strncpy(temp, udev->callout_value, sizeof(temp));
pos2 = temp;
while (num) {
num--;
pos3 = strsep(&pos2, " ");
if (pos3 == NULL) {
dbg("requested part of callout string not found");
break;
}
}
if (pos3) {
strcat(pos, pos3);
dbg("substitute partial callout output '%s'", pos3);
}
} else {
strcat(pos, udev->callout_value);
dbg("substitute callout output '%s'", udev->callout_value);
}
break;
default:
dbg("unknown substitution type '%%%c'", pos[1]);
break;
}
strcat(string, name);
} else
break;
}
}
static struct bus_file {
char *bus;
char *file;
} bus_files[] = {
{ .bus = "scsi", .file = "vendor" },
{ .bus = "usb", .file = "idVendor" },
{ .bus = "ide", .file = "detach_state" },
{ .bus = "pci", .file = "vendor" },
{}
};
#define SECONDS_TO_WAIT_FOR_FILE 10
static void wait_for_device_to_initialize(struct sysfs_device *sysfs_device)
{
/* sleep until we see the file for this specific bus type show up this
* is needed because we can easily out-run the kernel in looking for
* these files before the paticular subsystem has created them in the
* sysfs tree properly.
*
* And people thought that the /sbin/hotplug event system was going to
* be slow, poo on you for arguing that before even testing it...
*/
struct bus_file *b = &bus_files[0];
struct sysfs_attribute *tmpattr;
int loop;
while (1) {
if (b->bus == NULL)
break;
if (strcmp(sysfs_device->bus, b->bus) == 0) {
tmpattr = NULL;
loop = SECONDS_TO_WAIT_FOR_FILE;
while (loop--) {
dbg("looking for file '%s' on bus '%s'", b->file, b->bus);
tmpattr = sysfs_get_device_attr(sysfs_device, b->file);
if (tmpattr) {
/* found it! */
goto exit;
}
/* sleep to give the kernel a chance to create the file */
sleep(1);
}
dbg("Timed out waiting for '%s' file, continuing on anyway...", b->file);
goto exit;
}
b++;
}
dbg("Did not find bus type '%s' on list of bus_id_files, contact greg@kroah.com", sysfs_device->bus);
exit:
return; /* here to prevent compiler warning... */
}
static int exec_callout(struct config_device *dev, char *value, int len)
{
int retval;
int res;
int status;
int fds[2];
pid_t pid;
int value_set = 0;
char buffer[256];
char *pos;
char *args[CALLOUT_MAXARG];
int i;
dbg("callout to '%s'", dev->exec_program);
retval = pipe(fds);
if (retval != 0) {
dbg("pipe failed");
return -1;
}
pid = fork();
if (pid == -1) {
dbg("fork failed");
return -1;
}
if (pid == 0) {
/* child */
close(STDOUT_FILENO);
dup(fds[1]); /* dup write side of pipe to STDOUT */
if (strchr(dev->exec_program, ' ')) {
/* callout with arguments */
pos = dev->exec_program;
for (i=0; i < CALLOUT_MAXARG-1; i++) {
args[i] = strsep(&pos, " ");
if (args[i] == NULL)
break;
}
if (args[i]) {
dbg("too many args - %d", i);
args[i] = NULL;
}
retval = execve(args[0], args, main_envp);
} else {
retval = execve(dev->exec_program, main_argv, main_envp);
}
if (retval != 0) {
dbg("child execve failed");
exit(1);
}
return -1; /* avoid compiler warning */
} else {
/* parent reads from fds[0] */
close(fds[1]);
retval = 0;
while (1) {
res = read(fds[0], buffer, sizeof(buffer) - 1);
if (res <= 0)
break;
buffer[res] = '\0';
if (res > len) {
dbg("callout len %d too short", len);
retval = -1;
}
if (value_set) {
dbg("callout value already set");
retval = -1;
} else {
value_set = 1;
strncpy(value, buffer, len);
pos = value + strlen(value)-1;
if (pos[0] == '\n')
pos[0] = '\0';
dbg("callout returned '%s'", value);
}
}
close(fds[0]);
res = wait(&status);
if (res < 0) {
dbg("wait failed result %d", res);
retval = -1;
}
#ifndef __KLIBC__
if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
dbg("callout program status 0x%x", status);
retval = -1;
}
#endif
}
return retval;
}
static int do_callout(struct sysfs_class_device *class_dev, struct udevice *udev, struct sysfs_device *sysfs_device)
{
struct config_device *dev;
struct list_head *tmp;
list_for_each(tmp, &config_device_list) {
dev = list_entry(tmp, struct config_device, node);
if (dev->type != CALLOUT)
continue;
if (dev->bus[0] != '\0') {
/* as the user specified a bus, we must match it up */
if (!sysfs_device)
continue;
dbg("dev->bus='%s' sysfs_device->bus='%s'", dev->bus, sysfs_device->bus);
if (strcasecmp(dev->bus, sysfs_device->bus) != 0)
continue;
}
/* substitute anything that needs to be in the program name */
apply_format(udev, dev->exec_program);
if (exec_callout(dev, udev->callout_value, NAME_SIZE))
continue;
if (strcmp_pattern(dev->id, udev->callout_value) != 0)
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("callout returned matching value '%s', '%s' becomes '%s'",
dev->id, class_dev->name, udev->name);
return 0;
}
return -ENODEV;
}
static int match_pair(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct sysfs_pair *pair)
{
struct sysfs_attribute *tmpattr = NULL;
char *c;
if ((pair == NULL) || (pair->file[0] == '\0') || (pair->value == '\0'))
return -ENODEV;
dbg("look for device attribute '%s'", pair->file);
/* try to find the attribute in the class device directory */
tmpattr = sysfs_get_classdev_attr(class_dev, pair->file);
if (tmpattr)
goto label_found;
/* look in the class device directory if present */
if (sysfs_device) {
tmpattr = sysfs_get_device_attr(sysfs_device, pair->file);
if (tmpattr)
goto label_found;
}
return -ENODEV;
label_found:
c = tmpattr->value + strlen(tmpattr->value)-1;
if (*c == '\n')
*c = 0x00;
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 do_label(struct sysfs_class_device *class_dev, struct udevice *udev, struct sysfs_device *sysfs_device)
{
struct sysfs_pair *pair;
struct config_device *dev;
struct list_head *tmp;
int i;
int match;
list_for_each(tmp, &config_device_list) {
dev = list_entry(tmp, struct config_device, node);
if (dev->type != LABEL)
continue;
if (dev->bus[0] != '\0') {
/* as the user specified a bus, we must match it up */
if (!sysfs_device)
continue;
dbg("dev->bus='%s' sysfs_device->bus='%s'", dev->bus, sysfs_device->bus);
if (strcasecmp(dev->bus, sysfs_device->bus) != 0)
continue;
}
match = 1;
for (i = 0; i < MAX_SYSFS_PAIRS; ++i) {
pair = &dev->sysfs_pair[i];
if ((pair->file[0] == '\0') || (pair->value[0] == '\0'))
break;
if (match_pair(class_dev, sysfs_device, pair) != 0) {
match = 0;
break;
}
}
if (match == 0)
continue;
/* found match */
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("found matching attribute, '%s' becomes '%s' ",
class_dev->name, udev->name);
return 0;
}
return -ENODEV;
}
static int do_number(struct sysfs_class_device *class_dev, struct udevice *udev, struct sysfs_device *sysfs_device)
{
struct config_device *dev;
struct list_head *tmp;
char path[SYSFS_PATH_MAX];
int found;
char *temp = NULL;
/* we have to have a sysfs device for NUMBER to work */
if (!sysfs_device)
return -ENODEV;
list_for_each(tmp, &config_device_list) {
dev = list_entry(tmp, struct config_device, node);
if (dev->type != NUMBER)
continue;
dbg("dev->bus='%s' sysfs_device->bus='%s'", dev->bus, sysfs_device->bus);
if (strcasecmp(dev->bus, sysfs_device->bus) != 0)
continue;
found = 0;
strfieldcpy(path, sysfs_device->path);
temp = strrchr(path, '/');
dbg("search '%s' in '%s', path='%s'", dev->id, temp, path);
if (strstr(temp, dev->id) != NULL) {
found = 1;
} else {
*temp = 0x00;
temp = strrchr(path, '/');
dbg("search '%s' in '%s', path='%s'", dev->id, temp, path);
if (strstr(temp, dev->id) != NULL)
found = 1;
}
if (!found)
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("found matching id '%s', '%s' becomes '%s'",
dev->id, class_dev->name, udev->name);
return 0;
}
return -ENODEV;
}
static int do_topology(struct sysfs_class_device *class_dev, struct udevice *udev, struct sysfs_device *sysfs_device)
{
struct config_device *dev;
struct list_head *tmp;
char path[SYSFS_PATH_MAX];
int found;
char *temp = NULL;
/* we have to have a sysfs device for TOPOLOGY to work */
if (!sysfs_device)
return -ENODEV;
list_for_each(tmp, &config_device_list) {
dev = list_entry(tmp, struct config_device, node);
if (dev->type != TOPOLOGY)
continue;
dbg("dev->bus='%s' sysfs_device->bus='%s'", dev->bus, sysfs_device->bus);
if (strcasecmp(dev->bus, sysfs_device->bus) != 0)
continue;
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)
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("found matching place '%s', '%s' becomes '%s'",
dev->place, class_dev->name, udev->name);
return 0;
}
return -ENODEV;
}
static int do_replace(struct sysfs_class_device *class_dev, struct udevice *udev, struct sysfs_device *sysfs_device)
{
struct config_device *dev;
struct list_head *tmp;
list_for_each(tmp, &config_device_list) {
dev = list_entry(tmp, struct config_device, node);
if (dev->type != REPLACE)
continue;
dbg("compare name '%s' with '%s'", dev->kernel_name, class_dev->name);
if (strcmp_pattern(dev->kernel_name, class_dev->name) != 0)
continue;
strfieldcpy(udev->name, dev->name);
strfieldcpy(udev->symlink, dev->symlink);
dbg("found name, '%s' becomes '%s'", dev->kernel_name, udev->name);
return 0;
}
return -ENODEV;
}
static void do_kernelname(struct sysfs_class_device *class_dev, struct udevice *udev)
{
/* heh, this is pretty simple... */
strfieldcpy(udev->name, class_dev->name);
}
static struct sysfs_device *get_sysfs_device(struct sysfs_class_device *class_dev)
{
struct sysfs_device *sysfs_device;
struct sysfs_class_device *class_dev_parent;
int loop;
char filename[SYSFS_PATH_MAX + 6];
int retval;
char *temp;
int partition = 0;
/* Figure out where the device symlink is at. For char devices this will
* always be in the class_dev->path. But for block devices, it's different.
* The main block device will have the device symlink in it's path, but
* all partitions have the symlink in its parent directory.
* But we need to watch out for block devices that do not have parents, yet
* look like a partition (fd0, loop0, etc.) They all do not have a device
* symlink yet. We do sit and spin on waiting for them right now, we should
* possibly have a whitelist for these devices here...
*/
strcpy(filename, class_dev->path);
dbg("filename = %s", filename);
if (strcmp(class_dev->classname, SYSFS_BLOCK_NAME) == 0) {
if (isdigit(class_dev->path[strlen(class_dev->path)-1])) {
temp = strrchr(filename, '/');
if (temp) {
char *temp2 = strrchr(filename, '/');
partition = 1;
*temp = 0x00;
dbg("temp2 = %s", temp2);
if (temp2 && (strcmp(temp2, "/block") == 0)) {
/* oops, we have no parent block device, so go back to original directory */
strcpy(filename, class_dev->path);
partition = 0;
}
}
}
}
strcat(filename, "/device");
loop = 2;
while (loop--) {
struct stat buf;
dbg("looking for '%s'", filename);
retval = stat(filename, &buf);
if (!retval)
break;
/* sleep to give the kernel a chance to create the device file */
sleep(1);
}
loop = 1; /* FIXME put a real value in here for when everything is fixed... */
while (loop--) {
/* find the sysfs_device for this class device */
/* Wouldn't it really be nice if libsysfs could do this for us? */
sysfs_device = sysfs_get_classdev_device(class_dev);
if (sysfs_device != NULL)
goto exit;
/* if it's a partition, we need to get the parent device */
if (partition) {
/* FIXME HACK HACK HACK HACK
* for some reason partitions need this extra sleep here, in order
* to wait for the device properly. Once the libsysfs code is
* fixed properly, this sleep should go away, and we can just loop above.
*/
sleep(1);
dbg("really is a partition");
class_dev_parent = sysfs_get_classdev_parent(class_dev);
if (class_dev_parent == NULL) {
dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name);
} else {
dbg("class_dev_parent->name='%s'", class_dev_parent->name);
sysfs_device = sysfs_get_classdev_device(class_dev_parent);
if (sysfs_device != NULL)
goto exit;
}
}
/* sleep to give the kernel a chance to create the link */
/* FIXME remove comment...
sleep(1); */
}
dbg("Timed out waiting for device symlink, continuing on anyway...");
exit:
return sysfs_device;
}
int namedev_name_device(struct sysfs_class_device *class_dev, struct udevice *udev)
{
struct sysfs_device *sysfs_device = NULL;
int retval = 0;
struct perm_device *perm;
char *pos;
udev->mode = 0;
/* find the sysfs_device associated with this class device */
sysfs_device = get_sysfs_device(class_dev);
if (sysfs_device) {
dbg("sysfs_device->path='%s'", sysfs_device->path);
dbg("sysfs_device->bus_id='%s'", sysfs_device->bus_id);
dbg("sysfs_device->bus='%s'", sysfs_device->bus);
strfieldcpy(udev->bus_id, sysfs_device->bus_id);
wait_for_device_to_initialize(sysfs_device);
} else {
dbg("class_dev->name = '%s'", class_dev->name);
}
strfieldcpy(udev->kernel_name, class_dev->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);
/* rules are looked at in priority order */
retval = do_callout(class_dev, udev, sysfs_device);
if (retval == 0)
goto found;
retval = do_label(class_dev, udev, sysfs_device);
if (retval == 0)
goto found;
retval = do_number(class_dev, udev, sysfs_device);
if (retval == 0)
goto found;
retval = do_topology(class_dev, udev, sysfs_device);
if (retval == 0)
goto found;
retval = do_replace(class_dev, udev, sysfs_device);
if (retval == 0)
goto found;
do_kernelname(class_dev, udev);
goto done;
found:
/* substitute placeholder */
apply_format(udev, udev->name);
apply_format(udev, udev->symlink);
done:
perm = find_perm(udev->name);
if (perm) {
udev->mode = perm->mode;
strfieldcpy(udev->owner, perm->owner);
strfieldcpy(udev->group, perm->group);
} else {
/* no matching perms found :( */
udev->mode = get_default_mode(class_dev);
udev->owner[0] = 0x00;
udev->group[0] = 0x00;
}
dbg("name, '%s' is going to have owner='%s', group='%s', mode = %#o",
udev->name, udev->owner, udev->group, udev->mode);
return 0;
}
int namedev_init(void)
{
int retval;
retval = namedev_init_rules();
if (retval)
return retval;
retval = namedev_init_permissions();
if (retval)
return retval;
dump_config_dev_list();
dump_perm_dev_list();
return retval;
}
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