chiark / gitweb /
libude: remove special handling of "device" link, it should not be used
[elogind.git] / src / libudev / libudev-device.c
index 08476e6..6bb2e41 100644 (file)
@@ -1,13 +1,21 @@
-/*
- * libudev - interface to udev device information
- *
- * Copyright (C) 2008-2010 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.
- */
+/***
+  This file is part of systemd.
+
+  Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
+
+  systemd 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.
+
+  systemd 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -52,6 +60,8 @@ struct udev_device {
         const char *sysnum;
         char *devnode;
         mode_t devnode_mode;
+        uid_t devnode_uid;
+        gid_t devnode_gid;
         char *subsystem;
         char *devtype;
         char *driver;
@@ -67,7 +77,7 @@ struct udev_device {
         struct udev_list sysattr_list;
         struct udev_list tags_list;
         unsigned long long int seqnum;
-        unsigned long long int usec_initialized;
+        usec_t usec_initialized;
         int devlink_priority;
         int refcount;
         dev_t devnum;
@@ -246,7 +256,7 @@ static int udev_device_set_devtype(struct udev_device *udev_device, const char *
         return 0;
 }
 
-static int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
+int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
 {
         free(udev_device->subsystem);
         udev_device->subsystem = strdup(subsystem);
@@ -315,6 +325,40 @@ static int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t
         return 0;
 }
 
+uid_t udev_device_get_devnode_uid(struct udev_device *udev_device)
+{
+        if (!udev_device->info_loaded)
+                udev_device_read_uevent_file(udev_device);
+        return udev_device->devnode_uid;
+}
+
+static int udev_device_set_devnode_uid(struct udev_device *udev_device, uid_t uid)
+{
+        char num[32];
+
+        udev_device->devnode_uid = uid;
+        snprintf(num, sizeof(num), "%u", uid);
+        udev_device_add_property(udev_device, "DEVUID", num);
+        return 0;
+}
+
+gid_t udev_device_get_devnode_gid(struct udev_device *udev_device)
+{
+        if (!udev_device->info_loaded)
+                udev_device_read_uevent_file(udev_device);
+        return udev_device->devnode_gid;
+}
+
+static int udev_device_set_devnode_gid(struct udev_device *udev_device, gid_t gid)
+{
+        char num[32];
+
+        udev_device->devnode_gid = gid;
+        snprintf(num, sizeof(num), "%u", gid);
+        udev_device_add_property(udev_device, "DEVGID", num);
+        return 0;
+}
+
 struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
 {
         udev_device->envp_uptodate = false;
@@ -335,7 +379,7 @@ static struct udev_list_entry *udev_device_add_property_from_string(struct udev_
         char name[UTIL_LINE_SIZE];
         char *val;
 
-        util_strscpy(name, sizeof(name), property);
+        strscpy(name, sizeof(name), property);
         val = strchr(name, '=');
         if (val == NULL)
                 return NULL;
@@ -360,7 +404,7 @@ void udev_device_add_property_from_string_parse(struct udev_device *udev_device,
         if (startswith(property, "DEVPATH=")) {
                 char path[UTIL_PATH_SIZE];
 
-                util_strscpyl(path, sizeof(path), "/sys", &property[8], NULL);
+                strscpyl(path, sizeof(path), "/sys", &property[8], NULL);
                 udev_device_set_syspath(udev_device, path);
         } else if (startswith(property, "SUBSYSTEM=")) {
                 udev_device_set_subsystem(udev_device, &property[10]);
@@ -373,7 +417,7 @@ void udev_device_add_property_from_string_parse(struct udev_device *udev_device,
                 char *slink;
                 char *next;
 
-                util_strscpy(devlinks, sizeof(devlinks), &property[9]);
+                strscpy(devlinks, sizeof(devlinks), &property[9]);
                 slink = devlinks;
                 next = strchr(slink, ' ');
                 while (next != NULL) {
@@ -388,7 +432,7 @@ void udev_device_add_property_from_string_parse(struct udev_device *udev_device,
                 char tags[UTIL_PATH_SIZE];
                 char *next;
 
-                util_strscpy(tags, sizeof(tags), &property[5]);
+                strscpy(tags, sizeof(tags), &property[5]);
                 next = strchr(tags, ':');
                 if (next != NULL) {
                         next++;
@@ -422,6 +466,10 @@ void udev_device_add_property_from_string_parse(struct udev_device *udev_device,
                 udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
         } else if (startswith(property, "DEVMODE=")) {
                 udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8));
+        } else if (startswith(property, "DEVUID=")) {
+                udev_device_set_devnode_uid(udev_device, strtoul(&property[7], NULL, 10));
+        } else if (startswith(property, "DEVGID=")) {
+                udev_device_set_devnode_gid(udev_device, strtoul(&property[7], NULL, 10));
         } else {
                 udev_device_add_property_from_string(udev_device, property);
         }
@@ -479,7 +527,7 @@ int udev_device_read_db(struct udev_device *udev_device, const char *dbfile)
                 id = udev_device_get_id_filename(udev_device);
                 if (id == NULL)
                         return -1;
-                util_strscpyl(filename, sizeof(filename), "/run/udev/data/", id, NULL);
+                strscpyl(filename, sizeof(filename), "/run/udev/data/", id, NULL);
                 dbfile = filename;
         }
 
@@ -502,7 +550,7 @@ int udev_device_read_db(struct udev_device *udev_device, const char *dbfile)
                 val = &line[2];
                 switch(line[0]) {
                 case 'S':
-                        util_strscpyl(filename, sizeof(filename), "/dev/", val, NULL);
+                        strscpyl(filename, sizeof(filename), "/dev/", val, NULL);
                         udev_device_add_devlink(udev_device, filename);
                         break;
                 case 'L':
@@ -540,7 +588,7 @@ int udev_device_read_uevent_file(struct udev_device *udev_device)
         if (udev_device->uevent_loaded)
                 return 0;
 
-        util_strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
+        strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
         f = fopen(filename, "re");
         if (f == NULL)
                 return -1;
@@ -654,14 +702,14 @@ _public_ struct udev_device *udev_device_new_from_syspath(struct udev *udev, con
                 return NULL;
 
         /* resolve possible symlink to real path */
-        util_strscpy(path, sizeof(path), syspath);
+        strscpy(path, sizeof(path), syspath);
         util_resolve_sys_link(udev, path, sizeof(path));
 
         if (startswith(path + strlen("/sys"), "/devices/")) {
                 char file[UTIL_PATH_SIZE];
 
                 /* all "devices" require a "uevent" file */
-                util_strscpyl(file, sizeof(file), path, "/uevent", NULL);
+                strscpyl(file, sizeof(file), path, "/uevent", NULL);
                 if (stat(file, &statbuf) != 0)
                         return NULL;
         } else {
@@ -775,7 +823,7 @@ _public_ struct udev_device *udev_device_new_from_device_id(struct udev *udev, c
                 return NULL;
         }
         case '+':
-                util_strscpy(subsys, sizeof(subsys), &id[1]);
+                strscpy(subsys, sizeof(subsys), &id[1]);
                 sysname = strchr(subsys, ':');
                 if (sysname == NULL)
                         return NULL;
@@ -808,22 +856,22 @@ _public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev
         struct stat statbuf;
 
         if (streq(subsystem, "subsystem")) {
-                util_strscpyl(path, sizeof(path), "/sys/subsystem/", sysname, NULL);
+                strscpyl(path, sizeof(path), "/sys/subsystem/", sysname, NULL);
                 if (stat(path, &statbuf) == 0)
                         goto found;
 
-                util_strscpyl(path, sizeof(path), "/sys/bus/", sysname, NULL);
+                strscpyl(path, sizeof(path), "/sys/bus/", sysname, NULL);
                 if (stat(path, &statbuf) == 0)
                         goto found;
 
-                util_strscpyl(path, sizeof(path), "/sys/class/", sysname, NULL);
+                strscpyl(path, sizeof(path), "/sys/class/", sysname, NULL);
                 if (stat(path, &statbuf) == 0)
                         goto found;
                 goto out;
         }
 
         if (streq(subsystem, "module")) {
-                util_strscpyl(path, sizeof(path), "/sys/module/", sysname, NULL);
+                strscpyl(path, sizeof(path), "/sys/module/", sysname, NULL);
                 if (stat(path, &statbuf) == 0)
                         goto found;
                 goto out;
@@ -833,32 +881,32 @@ _public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev
                 char subsys[UTIL_NAME_SIZE];
                 char *driver;
 
-                util_strscpy(subsys, sizeof(subsys), sysname);
+                strscpy(subsys, sizeof(subsys), sysname);
                 driver = strchr(subsys, ':');
                 if (driver != NULL) {
                         driver[0] = '\0';
                         driver = &driver[1];
 
-                        util_strscpyl(path, sizeof(path), "/sys/subsystem/", subsys, "/drivers/", driver, NULL);
+                        strscpyl(path, sizeof(path), "/sys/subsystem/", subsys, "/drivers/", driver, NULL);
                         if (stat(path, &statbuf) == 0)
                                 goto found;
 
-                        util_strscpyl(path, sizeof(path), "/sys/bus/", subsys, "/drivers/", driver, NULL);
+                        strscpyl(path, sizeof(path), "/sys/bus/", subsys, "/drivers/", driver, NULL);
                         if (stat(path, &statbuf) == 0)
                                 goto found;
                 }
                 goto out;
         }
 
-        util_strscpyl(path, sizeof(path), "/sys/subsystem/", subsystem, "/devices/", sysname, NULL);
+        strscpyl(path, sizeof(path), "/sys/subsystem/", subsystem, "/devices/", sysname, NULL);
         if (stat(path, &statbuf) == 0)
                 goto found;
 
-        util_strscpyl(path, sizeof(path), "/sys/bus/", subsystem, "/devices/", sysname, NULL);
+        strscpyl(path, sizeof(path), "/sys/bus/", subsystem, "/devices/", sysname, NULL);
         if (stat(path, &statbuf) == 0)
                 goto found;
 
-        util_strscpyl(path, sizeof(path), "/sys/class/", subsystem, "/", sysname, NULL);
+        strscpyl(path, sizeof(path), "/sys/class/", subsystem, "/", sysname, NULL);
         if (stat(path, &statbuf) == 0)
                 goto found;
 out:
@@ -909,7 +957,7 @@ static struct udev_device *device_new_from_parent(struct udev_device *udev_devic
         char path[UTIL_PATH_SIZE];
         const char *subdir;
 
-        util_strscpy(path, sizeof(path), udev_device->syspath);
+        strscpy(path, sizeof(path), udev_device->syspath);
         subdir = path + strlen("/sys/");
         for (;;) {
                 char *pos;
@@ -1212,9 +1260,9 @@ _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct ud
                         size_t l;
 
                         s = symlinks;
-                        l = util_strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
+                        l = strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
                         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), NULL);
+                                l = strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
                         udev_device_add_property(udev_device, "DEVLINKS", symlinks);
                 }
         }
@@ -1227,9 +1275,9 @@ _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct ud
                         size_t l;
 
                         s = tags;
-                        l = util_strpcpyl(&s, sizeof(tags), ":", NULL);
+                        l = strpcpyl(&s, sizeof(tags), ":", NULL);
                         udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
-                                l = util_strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
+                                l = strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
                         udev_device_add_property(udev_device, "TAGS", tags);
                 }
         }
@@ -1267,7 +1315,7 @@ _public_ const char *udev_device_get_action(struct udev_device *udev_device)
  **/
 _public_ unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
 {
-        unsigned long long now_ts;
+        usec_t now_ts;
 
         if (udev_device == NULL)
                 return 0;
@@ -1275,23 +1323,23 @@ _public_ unsigned long long int udev_device_get_usec_since_initialized(struct ud
                 udev_device_read_db(udev_device, NULL);
         if (udev_device->usec_initialized == 0)
                 return 0;
-        now_ts = now_usec();
+        now_ts = now(CLOCK_MONOTONIC);
         if (now_ts == 0)
                 return 0;
         return now_ts - udev_device->usec_initialized;
 }
 
-unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device)
+usec_t udev_device_get_usec_initialized(struct udev_device *udev_device)
 {
         return udev_device->usec_initialized;
 }
 
-void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized)
+void udev_device_set_usec_initialized(struct udev_device *udev_device, usec_t usec_initialized)
 {
         char num[32];
 
         udev_device->usec_initialized = usec_initialized;
-        snprintf(num, sizeof(num), "%llu", usec_initialized);
+        snprintf(num, sizeof(num), "%llu", (unsigned long long)usec_initialized);
         udev_device_add_property(udev_device, "USEC_INITIALIZED", num);
 }
 
@@ -1326,15 +1374,13 @@ _public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_devi
         if (list_entry != NULL)
                 return udev_list_entry_get_value(list_entry);
 
-        util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
+        strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
         if (lstat(path, &statbuf) != 0) {
                 udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL);
                 goto out;
         }
 
         if (S_ISLNK(statbuf.st_mode)) {
-                struct udev_device *dev;
-
                 /*
                  * Some core links return only the last element of the target path,
                  * these are just values, the paths should not be exposed.
@@ -1350,16 +1396,6 @@ _public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_devi
                         goto out;
                 }
 
-                /* resolve link to a device and return its syspath */
-                util_strscpyl(path, sizeof(path), udev_device->syspath, "/", sysattr, NULL);
-                dev = udev_device_new_from_syspath(udev_device->udev, path);
-                if (dev != NULL) {
-                        list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr,
-                                                         udev_device_get_syspath(dev));
-                        val = udev_list_entry_get_value(list_entry);
-                        udev_device_unref(dev);
-                }
-
                 goto out;
         }
 
@@ -1391,6 +1427,91 @@ out:
         return val;
 }
 
+/**
+ * udev_device_set_sysattr_value:
+ * @udev_device: udev device
+ * @sysattr: attribute name
+ * @value: new value to be set
+ *
+ * Update the contents of the sys attribute and the cached value of the device.
+ *
+ * Returns: Negative error code on failure or 0 on success.
+ **/
+_public_ int udev_device_set_sysattr_value(struct udev_device *udev_device, const char *sysattr, char *value)
+{
+        struct udev_device *dev;
+        char path[UTIL_PATH_SIZE];
+        struct stat statbuf;
+        int fd;
+        ssize_t size, value_len;
+        int ret = 0;
+
+        if (udev_device == NULL)
+                return -EINVAL;
+        dev = udev_device;
+        if (sysattr == NULL)
+                return -EINVAL;
+        if (value == NULL)
+                value_len = 0;
+        else
+                value_len = strlen(value);
+
+        strscpyl(path, sizeof(path), udev_device_get_syspath(dev), "/", sysattr, NULL);
+        if (lstat(path, &statbuf) != 0) {
+                udev_list_entry_add(&dev->sysattr_value_list, sysattr, NULL);
+                ret = -ENXIO;
+                goto out;
+        }
+
+        if (S_ISLNK(statbuf.st_mode)) {
+                ret = -EINVAL;
+                goto out;
+        }
+
+        /* skip directories */
+        if (S_ISDIR(statbuf.st_mode)) {
+                ret = -EISDIR;
+                goto out;
+        }
+
+        /* skip non-readable files */
+        if ((statbuf.st_mode & S_IRUSR) == 0) {
+                ret = -EACCES;
+                goto out;
+        }
+
+        /* Value is limited to 4k */
+        if (value_len > 4096) {
+                ret = -EINVAL;
+                goto out;
+        }
+        util_remove_trailing_chars(value, '\n');
+
+        /* write attribute value */
+        fd = open(path, O_WRONLY|O_CLOEXEC);
+        if (fd < 0) {
+                ret = -errno;
+                goto out;
+        }
+        size = write(fd, value, value_len);
+        close(fd);
+        if (size < 0) {
+                ret = -errno;
+                goto out;
+        }
+        if (size < value_len) {
+                ret = -EIO;
+                goto out;
+        }
+
+        /* wrote a valid value, store it in cache and return it */
+        udev_list_entry_add(&dev->sysattr_value_list, sysattr, value);
+out:
+        if (dev != udev_device)
+                udev_device_unref(dev);
+        return ret;
+}
+
 static int udev_device_sysattr_list_read(struct udev_device *udev_device)
 {
         struct dirent *dent;
@@ -1414,7 +1535,7 @@ static int udev_device_sysattr_list_read(struct udev_device *udev_device)
                 if (dent->d_type != DT_LNK && dent->d_type != DT_REG)
                         continue;
 
-                util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
+                strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
                 if (lstat(path, &statbuf) != 0)
                         continue;
                 if ((statbuf.st_mode & S_IRUSR) == 0)
@@ -1673,10 +1794,10 @@ static int update_envp_monitor_buf(struct udev_device *udev_device)
                         return -EINVAL;
 
                 /* add property string to monitor buffer */
-                l = util_strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
+                l = strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
                 if (l == 0)
                         return -EINVAL;
-                /* advance past the trailing '\0' that util_strpcpyl() guarantees */
+                /* advance past the trailing '\0' that strpcpyl() guarantees */
                 s++;
                 l--;
         }