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/*
* libudev - interface to udev device information
*
* Copyright (C) 2003-2009 Kay Sievers <kay.sievers@vrfy.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*/
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <pwd.h>
#include <grp.h>
#include <sys/param.h>
#include "libudev.h"
#include "libudev-private.h"
static int create_path(struct udev *udev, const char *path, bool selinux)
{
char p[UTIL_PATH_SIZE];
char *pos;
struct stat stats;
int err;
util_strscpy(p, sizeof(p), path);
pos = strrchr(p, '/');
if (pos == NULL)
return 0;
while (pos != p && pos[-1] == '/')
pos--;
if (pos == p)
return 0;
pos[0] = '\0';
dbg(udev, "stat '%s'\n", p);
if (stat(p, &stats) == 0) {
if ((stats.st_mode & S_IFMT) == S_IFDIR)
return 0;
else
return -ENOTDIR;
}
err = util_create_path(udev, p);
if (err != 0)
return err;
dbg(udev, "mkdir '%s'\n", p);
if (selinux)
udev_selinux_setfscreatecon(udev, p, S_IFDIR|0755);
err = mkdir(p, 0755);
if (err != 0) {
err = -errno;
if (err == -EEXIST && stat(p, &stats) == 0) {
if ((stats.st_mode & S_IFMT) == S_IFDIR)
err = 0;
else
err = -ENOTDIR;
}
}
if (selinux)
udev_selinux_resetfscreatecon(udev);
return err;
}
int util_create_path(struct udev *udev, const char *path)
{
return create_path(udev, path, false);
}
int util_create_path_selinux(struct udev *udev, const char *path)
{
return create_path(udev, path, true);
}
int util_delete_path(struct udev *udev, const char *path)
{
char p[UTIL_PATH_SIZE];
char *pos;
int err = 0;
if (path[0] == '/')
while(path[1] == '/')
path++;
util_strscpy(p, sizeof(p), path);
pos = strrchr(p, '/');
if (pos == p || pos == NULL)
return 0;
for (;;) {
*pos = '\0';
pos = strrchr(p, '/');
/* don't remove the last one */
if ((pos == p) || (pos == NULL))
break;
err = rmdir(p);
if (err < 0) {
if (errno == ENOENT)
err = 0;
break;
}
}
return err;
}
/* Reset permissions on the device node, before unlinking it to make sure,
* that permissions of possible hard links will be removed too.
*/
int util_unlink_secure(struct udev *udev, const char *filename)
{
int err;
chown(filename, 0, 0);
chmod(filename, 0000);
err = unlink(filename);
if (errno == ENOENT)
err = 0;
if (err)
err(udev, "unlink(%s) failed: %m\n", filename);
return err;
}
uid_t util_lookup_user(struct udev *udev, const char *user)
{
char *endptr;
size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
char buf[buflen];
struct passwd pwbuf;
struct passwd *pw;
uid_t uid;
if (strcmp(user, "root") == 0)
return 0;
uid = strtoul(user, &endptr, 10);
if (endptr[0] == '\0')
return uid;
errno = getpwnam_r(user, &pwbuf, buf, buflen, &pw);
if (pw != NULL)
return pw->pw_uid;
if (errno == 0 || errno == ENOENT || errno == ESRCH)
err(udev, "specified user '%s' unknown\n", user);
else
err(udev, "error resolving user '%s': %m\n", user);
return 0;
}
gid_t util_lookup_group(struct udev *udev, const char *group)
{
char *endptr;
size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
char *buf;
struct group grbuf;
struct group *gr;
gid_t gid = 0;
if (strcmp(group, "root") == 0)
return 0;
gid = strtoul(group, &endptr, 10);
if (endptr[0] == '\0')
return gid;
buf = NULL;
gid = 0;
for (;;) {
char *newbuf;
newbuf = realloc(buf, buflen);
if (!newbuf)
break;
buf = newbuf;
errno = getgrnam_r(group, &grbuf, buf, buflen, &gr);
if (gr != NULL) {
gid = gr->gr_gid;
} else if (errno == ERANGE) {
buflen *= 2;
continue;
} else if (errno == 0 || errno == ENOENT || errno == ESRCH) {
err(udev, "specified group '%s' unknown\n", group);
} else {
err(udev, "error resolving group '%s': %m\n", group);
}
break;
}
free(buf);
return gid;
}
/* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
int util_resolve_subsys_kernel(struct udev *udev, const char *string,
char *result, size_t maxsize, int read_value)
{
char temp[UTIL_PATH_SIZE];
char *subsys;
char *sysname;
struct udev_device *dev;
char *attr;
if (string[0] != '[')
return -1;
util_strscpy(temp, sizeof(temp), string);
subsys = &temp[1];
sysname = strchr(subsys, '/');
if (sysname == NULL)
return -1;
sysname[0] = '\0';
sysname = &sysname[1];
attr = strchr(sysname, ']');
if (attr == NULL)
return -1;
attr[0] = '\0';
attr = &attr[1];
if (attr[0] == '/')
attr = &attr[1];
if (attr[0] == '\0')
attr = NULL;
if (read_value && attr == NULL)
return -1;
dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
if (dev == NULL)
return -1;
if (read_value) {
const char *val;
val = udev_device_get_sysattr_value(dev, attr);
if (val != NULL)
util_strscpy(result, maxsize, val);
else
result[0] = '\0';
info(udev, "value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
} else {
size_t l;
char *s;
s = result;
l = util_strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
if (attr != NULL)
util_strpcpyl(&s, l, "/", attr, NULL);
info(udev, "path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
}
udev_device_unref(dev);
return 0;
}
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