udev-event.c revision 75cb1ac51ea0176926c749bd0f22c19ce8b20e5f
/*
* Copyright (C) 2003-2010 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, either version 2 of the License, or
* (at your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/sockios.h>
#include "udev.h"
struct udev_event *udev_event_new(struct udev_device *dev)
{
struct udev_event *event;
event = calloc(1, sizeof(struct udev_event));
if (event == NULL)
return NULL;
event->dev = dev;
event->udev = udev_device_get_udev(dev);
udev_list_init(&event->run_list);
event->mode = 0660;
dbg(event->udev, "allocated event %p\n", event);
return event;
}
void udev_event_unref(struct udev_event *event)
{
if (event == NULL)
return;
udev_list_cleanup_entries(event->udev, &event->run_list);
free(event->tmp_node);
free(event->program_result);
free(event->name);
dbg(event->udev, "free event %p\n", event);
free(event);
}
size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size)
{
struct udev_device *dev = event->dev;
enum subst_type {
SUBST_UNKNOWN,
SUBST_TEMP_NODE,
SUBST_ATTR,
SUBST_ENV,
SUBST_KERNEL,
SUBST_KERNEL_NUMBER,
SUBST_DRIVER,
SUBST_DEVPATH,
SUBST_ID,
SUBST_MAJOR,
SUBST_MINOR,
SUBST_RESULT,
SUBST_PARENT,
SUBST_NAME,
SUBST_LINKS,
SUBST_ROOT,
SUBST_SYS,
};
static const struct subst_map {
char *name;
char fmt;
enum subst_type type;
} map[] = {
{ .name = "tempnode", .fmt = 'N', .type = SUBST_TEMP_NODE },
{ .name = "attr", .fmt = 's', .type = SUBST_ATTR },
{ .name = "sysfs", .fmt = 's', .type = SUBST_ATTR },
{ .name = "env", .fmt = 'E', .type = SUBST_ENV },
{ .name = "kernel", .fmt = 'k', .type = SUBST_KERNEL },
{ .name = "number", .fmt = 'n', .type = SUBST_KERNEL_NUMBER },
{ .name = "driver", .fmt = 'd', .type = SUBST_DRIVER },
{ .name = "devpath", .fmt = 'p', .type = SUBST_DEVPATH },
{ .name = "id", .fmt = 'b', .type = SUBST_ID },
{ .name = "major", .fmt = 'M', .type = SUBST_MAJOR },
{ .name = "minor", .fmt = 'm', .type = SUBST_MINOR },
{ .name = "result", .fmt = 'c', .type = SUBST_RESULT },
{ .name = "parent", .fmt = 'P', .type = SUBST_PARENT },
{ .name = "name", .fmt = 'D', .type = SUBST_NAME },
{ .name = "links", .fmt = 'L', .type = SUBST_LINKS },
{ .name = "root", .fmt = 'r', .type = SUBST_ROOT },
{ .name = "sys", .fmt = 'S', .type = SUBST_SYS },
};
const char *from;
char *s;
size_t l;
from = src;
s = dest;
l = size;
while (1) {
enum subst_type type = SUBST_UNKNOWN;
char attrbuf[UTIL_PATH_SIZE];
char *attr = NULL;
while (from[0] != '\0') {
if (from[0] == '$') {
/* substitute named variable */
unsigned int i;
if (from[1] == '$') {
from++;
goto copy;
}
for (i = 0; i < ARRAY_SIZE(map); i++) {
if (strncmp(&from[1], map[i].name, strlen(map[i].name)) == 0) {
type = map[i].type;
from += strlen(map[i].name)+1;
dbg(event->udev, "will substitute format name '%s'\n", map[i].name);
goto subst;
}
}
} else if (from[0] == '%') {
/* substitute format char */
unsigned int i;
if (from[1] == '%') {
from++;
goto copy;
}
for (i = 0; i < ARRAY_SIZE(map); i++) {
if (from[1] == map[i].fmt) {
type = map[i].type;
from += 2;
dbg(event->udev, "will substitute format char '%c'\n", map[i].fmt);
goto subst;
}
}
}
copy:
/* copy char */
if (l == 0)
goto out;
s[0] = from[0];
from++;
s++;
l--;
}
goto out;
subst:
/* extract possible $format{attr} */
if (from[0] == '{') {
unsigned int i;
from++;
for (i = 0; from[i] != '}'; i++) {
if (from[i] == '\0') {
err(event->udev, "missing closing brace for format '%s'\n", src);
goto out;
}
}
if (i >= sizeof(attrbuf))
goto out;
memcpy(attrbuf, from, i);
attrbuf[i] = '\0';
from += i+1;
attr = attrbuf;
} else {
attr = NULL;
}
switch (type) {
case SUBST_DEVPATH:
l = util_strpcpy(&s, l, udev_device_get_devpath(dev));
dbg(event->udev, "substitute devpath '%s'\n", udev_device_get_devpath(dev));
break;
case SUBST_KERNEL:
l = util_strpcpy(&s, l, udev_device_get_sysname(dev));
dbg(event->udev, "substitute kernel name '%s'\n", udev_device_get_sysname(dev));
break;
case SUBST_KERNEL_NUMBER:
if (udev_device_get_sysnum(dev) == NULL)
break;
l = util_strpcpy(&s, l, udev_device_get_sysnum(dev));
dbg(event->udev, "substitute kernel number '%s'\n", udev_device_get_sysnum(dev));
break;
case SUBST_ID:
if (event->dev_parent == NULL)
break;
l = util_strpcpy(&s, l, udev_device_get_sysname(event->dev_parent));
dbg(event->udev, "substitute id '%s'\n", udev_device_get_sysname(event->dev_parent));
break;
case SUBST_DRIVER: {
const char *driver;
if (event->dev_parent == NULL)
break;
driver = udev_device_get_driver(event->dev_parent);
if (driver == NULL)
break;
l = util_strpcpy(&s, l, driver);
dbg(event->udev, "substitute driver '%s'\n", driver);
break;
}
case SUBST_MAJOR: {
char num[UTIL_PATH_SIZE];
sprintf(num, "%d", major(udev_device_get_devnum(dev)));
l = util_strpcpy(&s, l, num);
dbg(event->udev, "substitute major number '%s'\n", num);
break;
}
case SUBST_MINOR: {
char num[UTIL_PATH_SIZE];
sprintf(num, "%d", minor(udev_device_get_devnum(dev)));
l = util_strpcpy(&s, l, num);
dbg(event->udev, "substitute minor number '%s'\n", num);
break;
}
case SUBST_RESULT: {
char *rest;
int i;
if (event->program_result == NULL)
break;
/* get part part of the result string */
i = 0;
if (attr != NULL)
i = strtoul(attr, &rest, 10);
if (i > 0) {
char result[UTIL_PATH_SIZE];
char tmp[UTIL_PATH_SIZE];
char *cpos;
dbg(event->udev, "request part #%d of result string\n", i);
util_strscpy(result, sizeof(result), event->program_result);
cpos = result;
while (--i) {
while (cpos[0] != '\0' && !isspace(cpos[0]))
cpos++;
while (isspace(cpos[0]))
cpos++;
}
if (i > 0) {
err(event->udev, "requested part of result string not found\n");
break;
}
util_strscpy(tmp, sizeof(tmp), cpos);
/* %{2+}c copies the whole string from the second part on */
if (rest[0] != '+') {
cpos = strchr(tmp, ' ');
if (cpos)
cpos[0] = '\0';
}
l = util_strpcpy(&s, l, tmp);
dbg(event->udev, "substitute part of result string '%s'\n", tmp);
} else {
l = util_strpcpy(&s, l, event->program_result);
dbg(event->udev, "substitute result string '%s'\n", event->program_result);
}
break;
}
case SUBST_ATTR: {
const char *value = NULL;
char vbuf[UTIL_NAME_SIZE];
size_t len;
int count;
if (attr == NULL) {
err(event->udev, "missing file parameter for attr\n");
break;
}
/* try to read the value specified by "[dmi/id]product_name" */
if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0)
value = vbuf;
/* try to read the attribute the device */
if (value == NULL)
value = udev_device_get_sysattr_value(event->dev, attr);
/* try to read the attribute of the parent device, other matches have selected */
if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev)
value = udev_device_get_sysattr_value(event->dev_parent, attr);
if (value == NULL)
break;
/* strip trailing whitespace, and replace unwanted characters */
if (value != vbuf)
util_strscpy(vbuf, sizeof(vbuf), value);
len = strlen(vbuf);
while (len > 0 && isspace(vbuf[--len]))
vbuf[len] = '\0';
count = udev_util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
if (count > 0)
info(event->udev, "%i character(s) replaced\n" , count);
l = util_strpcpy(&s, l, vbuf);
dbg(event->udev, "substitute sysfs value '%s'\n", vbuf);
break;
}
case SUBST_PARENT: {
struct udev_device *dev_parent;
const char *devnode;
dev_parent = udev_device_get_parent(event->dev);
if (dev_parent == NULL)
break;
devnode = udev_device_get_devnode(dev_parent);
if (devnode != NULL) {
size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
l = util_strpcpy(&s, l, &devnode[devlen]);
dbg(event->udev, "found parent '%s', got node name '%s'\n",
udev_device_get_syspath(dev_parent), &devnode[devlen]);
}
break;
}
case SUBST_TEMP_NODE: {
dev_t devnum;
struct stat statbuf;
char filename[UTIL_PATH_SIZE];
const char *devtype;
if (event->tmp_node != NULL) {
l = util_strpcpy(&s, l, event->tmp_node);
dbg(event->udev, "tempnode: return earlier created one\n");
break;
}
devnum = udev_device_get_devnum(dev);
if (major(devnum) == 0)
break;
/* lookup kernel provided node */
if (udev_device_get_knodename(dev) != NULL) {
util_strscpyl(filename, sizeof(filename),
udev_get_dev_path(event->udev), "/", udev_device_get_knodename(dev), NULL);
if (stat(filename, &statbuf) == 0 && statbuf.st_rdev == devnum) {
l = util_strpcpy(&s, l, filename);
dbg(event->udev, "tempnode: return kernel node\n");
break;
}
}
/* lookup /dev/{char,block}/<maj>:<min> */
if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
devtype = "block";
else
devtype = "char";
snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
udev_get_dev_path(event->udev), devtype,
major(udev_device_get_devnum(dev)),
minor(udev_device_get_devnum(dev)));
if (stat(filename, &statbuf) == 0 && statbuf.st_rdev == devnum) {
l = util_strpcpy(&s, l, filename);
dbg(event->udev, "tempnode: return maj:min node\n");
break;
}
/* create temporary node */
dbg(event->udev, "tempnode: create temp node\n");
asprintf(&event->tmp_node, "%s/.tmp-%s-%u:%u",
udev_get_dev_path(event->udev), devtype,
major(udev_device_get_devnum(dev)),
minor(udev_device_get_devnum(dev)));
if (event->tmp_node == NULL)
break;
udev_node_mknod(dev, event->tmp_node, 0600, 0, 0);
l = util_strpcpy(&s, l, event->tmp_node);
break;
}
case SUBST_NAME:
if (event->name != NULL) {
l = util_strpcpy(&s, l, event->name);
dbg(event->udev, "substitute name '%s'\n", event->name);
} else {
l = util_strpcpy(&s, l, udev_device_get_sysname(dev));
dbg(event->udev, "substitute sysname '%s'\n", udev_device_get_sysname(dev));
}
break;
case SUBST_LINKS: {
size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
struct udev_list_entry *list_entry;
list_entry = udev_device_get_devlinks_list_entry(dev);
if (list_entry == NULL)
break;
l = util_strpcpy(&s, l, &udev_list_entry_get_name(list_entry)[devlen]);
udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
l = util_strpcpyl(&s, l, " ", &udev_list_entry_get_name(list_entry)[devlen], NULL);
break;
}
case SUBST_ROOT:
l = util_strpcpy(&s, l, udev_get_dev_path(event->udev));
dbg(event->udev, "substitute udev_root '%s'\n", udev_get_dev_path(event->udev));
break;
case SUBST_SYS:
l = util_strpcpy(&s, l, udev_get_sys_path(event->udev));
dbg(event->udev, "substitute sys_path '%s'\n", udev_get_sys_path(event->udev));
break;
case SUBST_ENV:
if (attr == NULL) {
dbg(event->udev, "missing attribute\n");
break;
} else {
const char *value;
value = udev_device_get_property_value(event->dev, attr);
if (value == NULL)
break;
dbg(event->udev, "substitute env '%s=%s'\n", attr, value);
l = util_strpcpy(&s, l, value);
break;
}
default:
err(event->udev, "unknown substitution type=%i\n", type);
break;
}
}
out:
s[0] = '\0';
dbg(event->udev, "'%s' -> '%s' (%zu)\n", src, dest, l);
return l;
}
static void rename_netif_kernel_log(struct ifreq ifr)
{
int klog;
FILE *f;
klog = open("/dev/kmsg", O_WRONLY);
if (klog < 0)
return;
f = fdopen(klog, "w");
if (f == NULL) {
close(klog);
return;
}
fprintf(f, "<6>udev: renamed network interface %s to %s\n",
ifr.ifr_name, ifr.ifr_newname);
fclose(f);
}
static int rename_netif(struct udev_event *event)
{
struct udev_device *dev = event->dev;
int sk;
struct ifreq ifr;
int err;
info(event->udev, "changing net interface name from '%s' to '%s'\n",
udev_device_get_sysname(dev), event->name);
sk = socket(PF_INET, SOCK_DGRAM, 0);
if (sk < 0) {
err(event->udev, "error opening socket: %m\n");
return -1;
}
memset(&ifr, 0x00, sizeof(struct ifreq));
util_strscpy(ifr.ifr_name, IFNAMSIZ, udev_device_get_sysname(dev));
util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
err = ioctl(sk, SIOCSIFNAME, &ifr);
if (err == 0)
rename_netif_kernel_log(ifr);
else {
int loop;
/* see if the destination interface name already exists */
if (errno != EEXIST) {
err(event->udev, "error changing netif name %s to %s: %m\n",
ifr.ifr_name, ifr.ifr_newname);
goto exit;
}
/* free our own name, another process may wait for us */
util_strscpyl(ifr.ifr_newname, IFNAMSIZ, udev_device_get_sysname(dev), "_rename", NULL);
err = ioctl(sk, SIOCSIFNAME, &ifr);
if (err != 0) {
err(event->udev, "error changing netif name %s to %s: %m\n",
ifr.ifr_name, ifr.ifr_newname);
goto exit;
}
/* wait 90 seconds for our target to become available */
util_strscpy(ifr.ifr_name, IFNAMSIZ, ifr.ifr_newname);
util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
loop = 90 * 20;
while (loop--) {
const struct timespec duration = { 0, 1000 * 1000 * 1000 / 20 };
err = ioctl(sk, SIOCSIFNAME, &ifr);
if (err == 0) {
rename_netif_kernel_log(ifr);
break;
}
if (errno != EEXIST) {
err(event->udev, "error changing net interface name %s to %s: %m\n",
ifr.ifr_name, ifr.ifr_newname);
break;
}
dbg(event->udev, "wait for netif '%s' to become free, loop=%i\n",
event->name, (90 * 20) - loop);
nanosleep(&duration, NULL);
}
}
exit:
close(sk);
return err;
}
int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules)
{
struct udev_device *dev = event->dev;
int err = 0;
if (udev_device_get_sysname_old(dev) != NULL &&
strcmp(udev_device_get_sysname_old(dev), udev_device_get_sysname(dev)) != 0) {
udev_device_rename_db(dev);
info(event->udev, "moved database from '%s:%s' to '%s:%s'\n",
udev_device_get_subsystem(dev), udev_device_get_sysname_old(dev),
udev_device_get_subsystem(dev), udev_device_get_sysname(dev));
}
if (strcmp(udev_device_get_action(dev), "remove") == 0) {
udev_device_read_db(dev);
udev_device_delete_db(dev);
udev_device_tag_index(dev, NULL, false);
if (major(udev_device_get_devnum(dev)) != 0)
udev_watch_end(event->udev, dev);
udev_rules_apply_to_event(rules, event);
if (major(udev_device_get_devnum(dev)) != 0)
err = udev_node_remove(dev);
} else {
event->dev_db = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
if (event->dev_db != NULL) {
udev_device_read_db(event->dev_db);
udev_device_set_info_loaded(event->dev_db);
/* disable watch during event processing */
if (major(udev_device_get_devnum(dev)) != 0)
udev_watch_end(event->udev, event->dev_db);
}
udev_rules_apply_to_event(rules, event);
/* rename a new network interface, if needed */
if (strcmp(udev_device_get_subsystem(dev), "net") == 0 && strcmp(udev_device_get_action(dev), "add") == 0 &&
event->name != NULL && strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
char syspath[UTIL_PATH_SIZE];
char *pos;
err = rename_netif(event);
if (err == 0) {
info(event->udev, "renamed netif to '%s'\n", event->name);
/* delete stale db file */
udev_device_delete_db(dev);
udev_device_tag_index(dev, NULL, false);
/* remember old name */
udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
/* now change the devpath, because the kernel device name has changed */
util_strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
pos = strrchr(syspath, '/');
if (pos != NULL) {
pos++;
util_strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
udev_device_set_syspath(event->dev, syspath);
udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
info(event->udev, "changed devpath to '%s'\n", udev_device_get_devpath(dev));
}
}
}
if (major(udev_device_get_devnum(dev)) != 0) {
char filename[UTIL_PATH_SIZE];
if (event->tmp_node != NULL) {
info(event->udev, "cleanup temporary device node\n");
util_unlink_secure(event->udev, event->tmp_node);
free(event->tmp_node);
event->tmp_node = NULL;
}
/* no rule, use kernel provided name */
if (event->name == NULL) {
if (udev_device_get_knodename(dev) != NULL) {
event->name = strdup(udev_device_get_knodename(dev));
info(event->udev, "no node name set, will use kernel supplied name '%s'\n", event->name);
} else {
event->name = strdup(udev_device_get_sysname(event->dev));
info(event->udev, "no node name set, will use device name '%s'\n", event->name);
}
}
if (event->name == NULL || event->name[0] == '\0') {
udev_device_delete_db(dev);
udev_device_tag_index(dev, NULL, false);
udev_device_unref(event->dev_db);
err = -ENOMEM;
err(event->udev, "no node name, something went wrong, ignoring\n");
goto out;
}
if (udev_device_get_knodename(dev) != NULL && strcmp(udev_device_get_knodename(dev), event->name) != 0)
err(event->udev, "kernel-provided name '%s' and NAME= '%s' disagree, "
"please use SYMLINK+= or change the kernel to provide the proper name\n",
udev_device_get_knodename(dev), event->name);
/* set device node name */
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(event->udev), "/", event->name, NULL);
udev_device_set_devnode(dev, filename);
}
udev_device_update_db(dev);
udev_device_tag_index(dev, event->dev_db, true);
if (major(udev_device_get_devnum(dev)) != 0) {
/* remove/update possible left-over symlinks from old database entry */
if (event->dev_db != NULL)
udev_node_update_old_links(dev, event->dev_db);
err = udev_node_add(dev, event->mode, event->uid, event->gid);
}
udev_device_unref(event->dev_db);
event->dev_db = NULL;
}
out:
return err;
}
int udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask)
{
struct udev_list_entry *list_entry;
int err = 0;
dbg(event->udev, "executing run list\n");
udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
const char *cmd = udev_list_entry_get_name(list_entry);
if (strncmp(cmd, "socket:", strlen("socket:")) == 0) {
struct udev_monitor *monitor;
monitor = udev_monitor_new_from_socket(event->udev, &cmd[strlen("socket:")]);
if (monitor == NULL)
continue;
udev_monitor_send_device(monitor, NULL, event->dev);
udev_monitor_unref(monitor);
} else {
char program[UTIL_PATH_SIZE];
char **envp;
udev_event_apply_format(event, cmd, program, sizeof(program));
envp = udev_device_get_properties_envp(event->dev);
if (util_run_program(event->udev, program, envp, NULL, 0, NULL, sigmask) != 0) {
if (udev_list_entry_get_flags(list_entry))
err = -1;
}
}
}
return err;
}