udev-event.c revision dc4c7e463df35776631150e4e18a4ba41749843c
/*
* Copyright (C) 2004-2008 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 <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.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);
}
/* extract possible {attr} and move str behind it */
static char *get_format_attribute(struct udev *udev, char **str)
{
char *pos;
char *attr = NULL;
if (*str[0] == '{') {
pos = strchr(*str, '}');
if (pos == NULL) {
err(udev, "missing closing brace for format\n");
return NULL;
}
pos[0] = '\0';
attr = *str+1;
*str = pos+1;
dbg(udev, "attribute='%s', str='%s'\n", attr, *str);
}
return attr;
}
/* extract possible format length and move str behind it*/
static int get_format_len(struct udev *udev, char **str)
{
int num;
char *tail;
if (isdigit(*str[0])) {
num = (int) strtoul(*str, &tail, 10);
if (num > 0) {
*str = tail;
dbg(udev, "format length=%i\n", num);
return num;
} else {
err(udev, "format parsing error '%s'\n", *str);
}
}
return -1;
}
void udev_event_apply_format(struct udev_event *event, char *string, size_t maxsize)
{
struct udev_device *dev = event->dev;
char temp[UTIL_PATH_SIZE];
char temp2[UTIL_PATH_SIZE];
char *head, *tail, *cpos, *attr, *rest;
int len;
int i;
int count;
enum subst_type {
SUBST_UNKNOWN,
SUBST_DEVPATH,
SUBST_KERNEL,
SUBST_KERNEL_NUMBER,
SUBST_ID,
SUBST_DRIVER,
SUBST_MAJOR,
SUBST_MINOR,
SUBST_RESULT,
SUBST_ATTR,
SUBST_PARENT,
SUBST_TEMP_NODE,
SUBST_NAME,
SUBST_LINKS,
SUBST_ROOT,
SUBST_SYS,
SUBST_ENV,
};
static const struct subst_map {
char *name;
char fmt;
enum subst_type type;
} map[] = {
{ .name = "devpath", .fmt = 'p', .type = SUBST_DEVPATH },
{ .name = "number", .fmt = 'n', .type = SUBST_KERNEL_NUMBER },
{ .name = "kernel", .fmt = 'k', .type = SUBST_KERNEL },
{ .name = "id", .fmt = 'b', .type = SUBST_ID },
{ .name = "driver", .fmt = 'd', .type = SUBST_DRIVER },
{ .name = "major", .fmt = 'M', .type = SUBST_MAJOR },
{ .name = "minor", .fmt = 'm', .type = SUBST_MINOR },
{ .name = "result", .fmt = 'c', .type = SUBST_RESULT },
{ .name = "attr", .fmt = 's', .type = SUBST_ATTR },
{ .name = "sysfs", .fmt = 's', .type = SUBST_ATTR },
{ .name = "parent", .fmt = 'P', .type = SUBST_PARENT },
{ .name = "tempnode", .fmt = 'N', .type = SUBST_TEMP_NODE },
{ .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 },
{ .name = "env", .fmt = 'E', .type = SUBST_ENV },
{ NULL, '\0', 0 }
};
enum subst_type type;
const struct subst_map *subst;
head = string;
while (1) {
len = -1;
while (head[0] != '\0') {
if (head[0] == '$') {
/* substitute named variable */
if (head[1] == '\0')
break;
if (head[1] == '$') {
util_strlcpy(temp, head+2, sizeof(temp));
util_strlcpy(head+1, temp, maxsize);
head++;
continue;
}
head[0] = '\0';
for (subst = map; subst->name; subst++) {
if (strncasecmp(&head[1], subst->name, strlen(subst->name)) == 0) {
type = subst->type;
tail = head + strlen(subst->name)+1;
dbg(event->udev, "will substitute format name '%s'\n", subst->name);
goto found;
}
}
head[0] = '$';
err(event->udev, "unknown format variable '%s'\n", head);
} else if (head[0] == '%') {
/* substitute format char */
if (head[1] == '\0')
break;
if (head[1] == '%') {
util_strlcpy(temp, head+2, sizeof(temp));
util_strlcpy(head+1, temp, maxsize);
head++;
continue;
}
head[0] = '\0';
tail = head+1;
len = get_format_len(event->udev, &tail);
for (subst = map; subst->name; subst++) {
if (tail[0] == subst->fmt) {
type = subst->type;
tail++;
dbg(event->udev, "will substitute format char '%c'\n", subst->fmt);
goto found;
}
}
head[0] = '%';
err(event->udev, "unknown format char '%c'\n", tail[0]);
}
head++;
}
break;
found:
attr = get_format_attribute(event->udev, &tail);
util_strlcpy(temp, tail, sizeof(temp));
dbg(event->udev, "format=%i, string='%s', tail='%s'\n", type ,string, tail);
switch (type) {
case SUBST_DEVPATH:
util_strlcat(string, udev_device_get_devpath(dev), maxsize);
dbg(event->udev, "substitute devpath '%s'\n", udev_device_get_devpath(dev));
break;
case SUBST_KERNEL:
util_strlcat(string, udev_device_get_sysname(dev), maxsize);
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;
util_strlcat(string, udev_device_get_sysnum(dev), maxsize);
dbg(event->udev, "substitute kernel number '%s'\n", udev_device_get_sysnum(dev));
break;
case SUBST_ID:
if (event->dev_parent != NULL) {
util_strlcat(string, udev_device_get_sysname(event->dev_parent), maxsize);
dbg(event->udev, "substitute id '%s'\n", udev_device_get_sysname(event->dev_parent));
}
break;
case SUBST_DRIVER:
if (event->dev_parent != NULL) {
const char *driver = udev_device_get_driver(event->dev_parent);
if (driver == NULL)
break;
util_strlcat(string, driver, maxsize);
dbg(event->udev, "substitute driver '%s'\n", driver);
}
break;
case SUBST_MAJOR:
sprintf(temp2, "%d", major(udev_device_get_devnum(dev)));
util_strlcat(string, temp2, maxsize);
dbg(event->udev, "substitute major number '%s'\n", temp2);
break;
case SUBST_MINOR:
sprintf(temp2, "%d", minor(udev_device_get_devnum(dev)));
util_strlcat(string, temp2, maxsize);
dbg(event->udev, "substitute minor number '%s'\n", temp2);
break;
case SUBST_RESULT:
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];
dbg(event->udev, "request part #%d of result string\n", i);
util_strlcpy(result, event->program_result, sizeof(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_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';
}
util_strlcat(string, temp2, maxsize);
dbg(event->udev, "substitute part of result string '%s'\n", temp2);
} else {
util_strlcat(string, event->program_result, maxsize);
dbg(event->udev, "substitute result string '%s'\n", event->program_result);
}
break;
case SUBST_ATTR:
if (attr == NULL)
err(event->udev, "missing file parameter for attr\n");
else {
const char *val;
char value[UTIL_NAME_SIZE];
size_t size;
value[0] = '\0';
/* read the value specified by [usb/]*/
util_resolve_subsys_kernel(event->udev, attr, value, sizeof(value), 1);
/* try to read attribute of the current device */
if (value[0] == '\0') {
val = udev_device_get_sysattr_value(event->dev, attr);
if (val != NULL)
util_strlcpy(value, val, sizeof(value));
}
/* try to read the attribute of the parent device, other matches have selected */
if (value[0] == '\0' && event->dev_parent != NULL && event->dev_parent != event->dev) {
val = udev_device_get_sysattr_value(event->dev_parent, attr);
if (val != NULL)
util_strlcpy(value, val, sizeof(value));
}
if (value[0]=='\0')
break;
/* strip trailing whitespace, and replace unwanted characters */
size = strlen(value);
while (size > 0 && isspace(value[--size]))
value[size] = '\0';
count = util_replace_chars(value, ALLOWED_CHARS_INPUT);
if (count > 0)
info(event->udev, "%i character(s) replaced\n" , count);
util_strlcat(string, value, maxsize);
dbg(event->udev, "substitute sysfs value '%s'\n", value);
}
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;
util_strlcat(string, &devnode[devlen], maxsize);
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) {
util_strlcat(string, event->tmp_node, maxsize);
dbg(event->udev, "return existing temporary node\n");
break;
}
devnum = udev_device_get_devnum(dev);
if (major(udev_device_get_devnum(dev) == 0))
break;
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) {
util_strlcat(string, filename, maxsize);
dbg(event->udev, "return existing temporary node\n");
break;
}
dbg(event->udev, "create temporary 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, makedev(0, 0), 0600, 0, 0);
util_strlcat(string, event->tmp_node, maxsize);
}
break;
case SUBST_NAME:
if (event->name != NULL) {
util_strlcat(string, event->name, maxsize);
dbg(event->udev, "substitute name '%s'\n", event->name);
} else {
util_strlcat(string, udev_device_get_sysname(dev), maxsize);
dbg(event->udev, "substitute sysname '%s'\n", udev_device_get_sysname(dev));
}
break;
case SUBST_LINKS:
{
struct udev_list_entry *list_entry;
list_entry = udev_device_get_properties_list_entry(dev);
util_strlcpy(string, udev_list_entry_get_name(list_entry), maxsize);
udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry)) {
util_strlcat(string, " ", maxsize);
util_strlcat(string, udev_list_entry_get_name(list_entry), maxsize);
}
}
break;
case SUBST_ROOT:
util_strlcat(string, udev_get_dev_path(event->udev), maxsize);
dbg(event->udev, "substitute udev_root '%s'\n", udev_get_dev_path(event->udev));
break;
case SUBST_SYS:
util_strlcat(string, udev_get_sys_path(event->udev), maxsize);
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 {
struct udev_list_entry *list_entry;
const char *value;
list_entry = udev_device_get_properties_list_entry(event->dev);
list_entry = udev_list_entry_get_by_name(list_entry, attr);
if (list_entry == NULL)
break;
value = udev_list_entry_get_value(list_entry);
dbg(event->udev, "substitute env '%s=%s'\n", attr, value);
util_strlcat(string, value, maxsize);
break;
}
default:
err(event->udev, "unknown substitution type=%i\n", type);
break;
}
/* possibly truncate to format-char specified length */
if (len >= 0 && len < (int)strlen(head)) {
head[len] = '\0';
dbg(event->udev, "truncate to %i chars, subtitution string becomes '%s'\n", len, head);
}
util_strlcat(string, temp, maxsize);
}
}
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);
if (event->test)
return 0;
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_strlcpy(ifr.ifr_name, udev_device_get_sysname(dev), IFNAMSIZ);
util_strlcpy(ifr.ifr_newname, event->name, IFNAMSIZ);
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_strlcpy(ifr.ifr_newname, udev_device_get_sysname(dev), IFNAMSIZ);
util_strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
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 30 seconds for our target to become available */
util_strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
util_strlcpy(ifr.ifr_newname, udev_device_get_devnode(dev), IFNAMSIZ);
loop = 30 * 20;
while (loop--) {
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",
udev_device_get_devnode(dev), (30 * 20) - loop);
usleep(1000 * 1000 / 20);
}
}
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_devpath_old(dev) != NULL) {
if (udev_device_rename_db(dev, udev_device_get_devpath(dev)) == 0)
info(event->udev, "moved database from '%s' to '%s'\n",
udev_device_get_devpath_old(dev), udev_device_get_devpath(dev));
}
/* add device node */
if (major(udev_device_get_devnum(dev)) != 0 &&
(strcmp(udev_device_get_action(dev), "add") == 0 || strcmp(udev_device_get_action(dev), "change") == 0)) {
char filename[UTIL_PATH_SIZE];
struct udev_device *dev_old;
dbg(event->udev, "device node add '%s'\n", udev_device_get_devpath(dev));
udev_rules_apply_to_event(rules, event);
if (event->tmp_node != NULL) {
dbg(event->udev, "removing temporary device node\n");
util_unlink_secure(event->udev, event->tmp_node);
free(event->tmp_node);
event->tmp_node = NULL;
}
if (event->ignore_device) {
info(event->udev, "device event will be ignored\n");
goto exit;
}
if (event->name != NULL && event->name[0] == '\0') {
info(event->udev, "device node creation supressed\n");
goto exit;
}
if (event->name == NULL) {
info(event->udev, "no node name set, will use kernel name '%s'\n",
udev_device_get_sysname(event->dev));
event->name = strdup(udev_device_get_sysname(event->dev));
if (event->name == NULL)
goto exit;
}
/* set device node name */
util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
util_strlcat(filename, "/", sizeof(filename));
util_strlcat(filename, event->name, sizeof(filename));
udev_device_set_devnode(dev, filename);
/* read current database entry; cleanup, if it is known device */
dev_old = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
if (dev_old != NULL) {
if (udev_device_get_devnode(dev_old) != NULL) {
info(event->udev, "device node '%s' already in database, updating\n",
udev_device_get_devnode(dev_old));
udev_node_update_old_links(dev, dev_old, event->test);
}
udev_device_unref(dev_old);
}
udev_device_update_db(dev);
err = udev_node_add(dev, event->mode, event->uid, event->gid, event->test);
if (err != 0)
goto exit;
goto exit;
}
/* add netif */
if (strcmp(udev_device_get_subsystem(dev), "net") == 0 && strcmp(udev_device_get_action(dev), "add") == 0) {
dbg(event->udev, "netif add '%s'\n", udev_device_get_devpath(dev));
udev_rules_apply_to_event(rules, event);
if (event->ignore_device) {
info(event->udev, "device event will be ignored\n");
goto exit;
}
if (event->name == NULL)
goto exit;
/* look if we want to change the name of the netif */
if (strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
char syspath[UTIL_PATH_SIZE];
char *pos;
err = rename_netif(event);
if (err != 0)
goto exit;
info(event->udev, "renamed netif to '%s'\n", event->name);
/* 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_strlcpy(syspath, udev_device_get_syspath(dev), sizeof(syspath));
pos = strrchr(syspath, '/');
if (pos != NULL) {
pos[1] = '\0';
util_strlcat(syspath, event->name, sizeof(syspath));
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));
}
}
goto exit;
}
/* remove device node */
if (major(udev_device_get_devnum(dev)) != 0 && strcmp(udev_device_get_action(dev), "remove") == 0) {
/* import database entry and delete it */
udev_device_read_db(dev);
if (!event->test)
udev_device_delete_db(dev);
if (udev_device_get_devnode(dev) == NULL) {
char devnode[UTIL_PATH_SIZE];
info(event->udev, "'%s' not found in database, using kernel name '%s'\n",
udev_device_get_syspath(dev), udev_device_get_sysname(dev));
util_strlcpy(devnode, udev_get_dev_path(event->udev), sizeof(devnode));
util_strlcat(devnode, "/", sizeof(devnode));
util_strlcat(devnode, udev_device_get_sysname(dev), sizeof(devnode));
udev_device_set_devnode(dev, devnode);
}
udev_rules_apply_to_event(rules, event);
if (event->ignore_device) {
info(event->udev, "device event will be ignored\n");
goto exit;
}
if (udev_device_get_ignore_remove(dev)) {
info(event->udev, "ignore_remove for '%s'\n", udev_device_get_devnode(dev));
goto exit;
}
err = udev_node_remove(dev, event->test);
goto exit;
}
/* default devices */
udev_rules_apply_to_event(rules, event);
if (event->ignore_device)
info(event->udev, "device event will be ignored\n");
exit:
return err;
}
int udev_event_execute_run(struct udev_event *event)
{
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, event->dev);
udev_monitor_unref(monitor);
} else {
char program[UTIL_PATH_SIZE];
char **envp;
util_strlcpy(program, cmd, sizeof(program));
udev_event_apply_format(event, program, sizeof(program));
envp = udev_device_get_properties_envp(event->dev);
if (util_run_program(event->udev, program, envp, NULL, 0, NULL) != 0) {
if (!udev_list_entry_get_flag(list_entry))
err = -1;
}
}
}
return err;
}