/* * Copyright (C) 2005-2008 Kay Sievers * * 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 . */ #include #include #include #include #include #include #include #include #include #include "udev.h" /* device cache */ static LIST_HEAD(dev_list); /* attribute value cache */ static LIST_HEAD(attr_list); struct sysfs_attr { struct list_head node; char path[UTIL_PATH_SIZE]; char *value; /* points to value_local if value is cached */ char value_local[UTIL_NAME_SIZE]; }; static int resolve_sys_link(struct udev *udev, char *path, size_t size) { char link_path[UTIL_PATH_SIZE]; char link_target[UTIL_PATH_SIZE]; int len; int i; int back; util_strlcpy(link_path, udev_get_sys_path(udev), sizeof(link_path)); util_strlcat(link_path, path, sizeof(link_path)); len = readlink(link_path, link_target, sizeof(link_target)); if (len <= 0) return -1; link_target[len] = '\0'; dbg(udev, "path link '%s' points to '%s'\n", path, link_target); for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++) ; dbg(udev, "base '%s', tail '%s', back %i\n", path, &link_target[back * 3], back); for (i = 0; i <= back; i++) { char *pos = strrchr(path, '/'); if (pos == NULL) return -1; pos[0] = '\0'; } dbg(udev, "after moving back '%s'\n", path); util_strlcat(path, "/", size); util_strlcat(path, &link_target[back * 3], size); return 0; } int sysfs_init(void) { INIT_LIST_HEAD(&dev_list); INIT_LIST_HEAD(&attr_list); return 0; } void sysfs_cleanup(void) { struct sysfs_attr *attr_loop; struct sysfs_attr *attr_temp; struct sysfs_device *dev_loop; struct sysfs_device *dev_temp; list_for_each_entry_safe(attr_loop, attr_temp, &attr_list, node) { list_del(&attr_loop->node); free(attr_loop); } list_for_each_entry_safe(dev_loop, dev_temp, &dev_list, node) { list_del(&dev_loop->node); free(dev_loop); } } void sysfs_device_set_values(struct udev *udev, struct sysfs_device *dev, const char *devpath, const char *subsystem, const char *driver) { char *pos; util_strlcpy(dev->devpath, devpath, sizeof(dev->devpath)); if (subsystem != NULL) util_strlcpy(dev->subsystem, subsystem, sizeof(dev->subsystem)); if (driver != NULL) util_strlcpy(dev->driver, driver, sizeof(dev->driver)); /* set kernel name */ pos = strrchr(dev->devpath, '/'); if (pos == NULL) return; util_strlcpy(dev->kernel, &pos[1], sizeof(dev->kernel)); dbg(udev, "kernel='%s'\n", dev->kernel); /* some devices have '!' in their name, change that to '/' */ pos = dev->kernel; while (pos[0] != '\0') { if (pos[0] == '!') pos[0] = '/'; pos++; } /* get kernel number */ pos = &dev->kernel[strlen(dev->kernel)]; while (isdigit(pos[-1])) pos--; util_strlcpy(dev->kernel_number, pos, sizeof(dev->kernel_number)); dbg(udev, "kernel_number='%s'\n", dev->kernel_number); } struct sysfs_device *sysfs_device_get(struct udev *udev, const char *devpath) { char path[UTIL_PATH_SIZE]; char devpath_real[UTIL_PATH_SIZE]; struct sysfs_device *dev; struct sysfs_device *dev_loop; struct stat statbuf; char link_path[UTIL_PATH_SIZE]; char link_target[UTIL_PATH_SIZE]; int len; char *pos; /* we handle only these devpathes */ if (devpath != NULL && strncmp(devpath, "/devices/", 9) != 0 && strncmp(devpath, "/subsystem/", 11) != 0 && strncmp(devpath, "/module/", 8) != 0 && strncmp(devpath, "/bus/", 5) != 0 && strncmp(devpath, "/class/", 7) != 0 && strncmp(devpath, "/block/", 7) != 0) return NULL; dbg(udev, "open '%s'\n", devpath); util_strlcpy(devpath_real, devpath, sizeof(devpath_real)); util_remove_trailing_chars(devpath_real, '/'); if (devpath[0] == '\0' ) return NULL; /* look for device already in cache (we never put an untranslated path in the cache) */ list_for_each_entry(dev_loop, &dev_list, node) { if (strcmp(dev_loop->devpath, devpath_real) == 0) { dbg(udev, "found in cache '%s'\n", dev_loop->devpath); return dev_loop; } } /* if we got a link, resolve it to the real device */ util_strlcpy(path, udev_get_sys_path(udev), sizeof(path)); util_strlcat(path, devpath_real, sizeof(path)); if (lstat(path, &statbuf) != 0) { dbg(udev, "stat '%s' failed: %s\n", path, strerror(errno)); return NULL; } if (S_ISLNK(statbuf.st_mode)) { if (resolve_sys_link(udev, devpath_real, sizeof(devpath_real)) != 0) return NULL; /* now look for device in cache after path translation */ list_for_each_entry(dev_loop, &dev_list, node) { if (strcmp(dev_loop->devpath, devpath_real) == 0) { dbg(udev, "found in cache '%s'\n", dev_loop->devpath); return dev_loop; } } } /* it is a new device */ dbg(udev, "new uncached device '%s'\n", devpath_real); dev = malloc(sizeof(struct sysfs_device)); if (dev == NULL) return NULL; memset(dev, 0x00, sizeof(struct sysfs_device)); sysfs_device_set_values(udev, dev, devpath_real, NULL, NULL); /* get subsystem name */ util_strlcpy(link_path, udev_get_sys_path(udev), sizeof(link_path)); util_strlcat(link_path, dev->devpath, sizeof(link_path)); util_strlcat(link_path, "/subsystem", sizeof(link_path)); len = readlink(link_path, link_target, sizeof(link_target)); if (len > 0) { /* get subsystem from "subsystem" link */ link_target[len] = '\0'; dbg(udev, "subsystem link '%s' points to '%s'\n", link_path, link_target); pos = strrchr(link_target, '/'); if (pos != NULL) util_strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem)); } else if (strstr(dev->devpath, "/drivers/") != NULL) { util_strlcpy(dev->subsystem, "drivers", sizeof(dev->subsystem)); } else if (strncmp(dev->devpath, "/module/", 8) == 0) { util_strlcpy(dev->subsystem, "module", sizeof(dev->subsystem)); } else if (strncmp(dev->devpath, "/subsystem/", 11) == 0) { pos = strrchr(dev->devpath, '/'); if (pos == &dev->devpath[10]) util_strlcpy(dev->subsystem, "subsystem", sizeof(dev->subsystem)); } else if (strncmp(dev->devpath, "/class/", 7) == 0) { pos = strrchr(dev->devpath, '/'); if (pos == &dev->devpath[6]) util_strlcpy(dev->subsystem, "subsystem", sizeof(dev->subsystem)); } else if (strncmp(dev->devpath, "/bus/", 5) == 0) { pos = strrchr(dev->devpath, '/'); if (pos == &dev->devpath[4]) util_strlcpy(dev->subsystem, "subsystem", sizeof(dev->subsystem)); } /* get driver name */ util_strlcpy(link_path, udev_get_sys_path(udev), sizeof(link_path)); util_strlcat(link_path, dev->devpath, sizeof(link_path)); util_strlcat(link_path, "/driver", sizeof(link_path)); len = readlink(link_path, link_target, sizeof(link_target)); if (len > 0) { link_target[len] = '\0'; dbg(udev, "driver link '%s' points to '%s'\n", link_path, link_target); pos = strrchr(link_target, '/'); if (pos != NULL) util_strlcpy(dev->driver, &pos[1], sizeof(dev->driver)); } dbg(udev, "add to cache 'devpath=%s', subsystem='%s', driver='%s'\n", dev->devpath, dev->subsystem, dev->driver); list_add(&dev->node, &dev_list); return dev; } struct sysfs_device *sysfs_device_get_parent(struct udev *udev, struct sysfs_device *dev) { char parent_devpath[UTIL_PATH_SIZE]; char *pos; dbg(udev, "open '%s'\n", dev->devpath); /* look if we already know the parent */ if (dev->parent != NULL) return dev->parent; util_strlcpy(parent_devpath, dev->devpath, sizeof(parent_devpath)); dbg(udev, "'%s'\n", parent_devpath); /* strip last element */ pos = strrchr(parent_devpath, '/'); if (pos == NULL || pos == parent_devpath) return NULL; pos[0] = '\0'; if (strncmp(parent_devpath, "/class", 6) == 0) { pos = strrchr(parent_devpath, '/'); if (pos == &parent_devpath[6] || pos == parent_devpath) { dbg(udev, "/class top level, look for device link\n"); goto device_link; } } if (strcmp(parent_devpath, "/block") == 0) { dbg(udev, "/block top level, look for device link\n"); goto device_link; } /* are we at the top level? */ pos = strrchr(parent_devpath, '/'); if (pos == NULL || pos == parent_devpath) return NULL; /* get parent and remember it */ dev->parent = sysfs_device_get(udev, parent_devpath); return dev->parent; device_link: util_strlcpy(parent_devpath, dev->devpath, sizeof(parent_devpath)); util_strlcat(parent_devpath, "/device", sizeof(parent_devpath)); if (resolve_sys_link(udev, parent_devpath, sizeof(parent_devpath)) != 0) return NULL; /* get parent and remember it */ dev->parent = sysfs_device_get(udev, parent_devpath); return dev->parent; } struct sysfs_device *sysfs_device_get_parent_with_subsystem(struct udev *udev, struct sysfs_device *dev, const char *subsystem) { struct sysfs_device *dev_parent; dev_parent = sysfs_device_get_parent(udev, dev); while (dev_parent != NULL) { if (strcmp(dev_parent->subsystem, subsystem) == 0) return dev_parent; dev_parent = sysfs_device_get_parent(udev, dev_parent); } return NULL; } char *sysfs_attr_get_value(struct udev *udev, const char *devpath, const char *attr_name) { char path_full[UTIL_PATH_SIZE]; const char *path; char value[UTIL_NAME_SIZE]; struct sysfs_attr *attr_loop; struct sysfs_attr *attr; struct stat statbuf; int fd; ssize_t size; size_t sysfs_len; dbg(udev, "open '%s'/'%s'\n", devpath, attr_name); sysfs_len = util_strlcpy(path_full, udev_get_sys_path(udev), sizeof(path_full)); if(sysfs_len >= sizeof(path_full)) sysfs_len = sizeof(path_full) - 1; path = &path_full[sysfs_len]; util_strlcat(path_full, devpath, sizeof(path_full)); util_strlcat(path_full, "/", sizeof(path_full)); util_strlcat(path_full, attr_name, sizeof(path_full)); /* look for attribute in cache */ list_for_each_entry(attr_loop, &attr_list, node) { if (strcmp(attr_loop->path, path) == 0) { dbg(udev, "found in cache '%s'\n", attr_loop->path); return attr_loop->value; } } /* store attribute in cache (also negatives are kept in cache) */ dbg(udev, "new uncached attribute '%s'\n", path_full); attr = malloc(sizeof(struct sysfs_attr)); if (attr == NULL) return NULL; memset(attr, 0x00, sizeof(struct sysfs_attr)); util_strlcpy(attr->path, path, sizeof(attr->path)); dbg(udev, "add to cache '%s'\n", path_full); list_add(&attr->node, &attr_list); if (lstat(path_full, &statbuf) != 0) { dbg(udev, "stat '%s' failed: %s\n", path_full, strerror(errno)); goto out; } if (S_ISLNK(statbuf.st_mode)) { /* links return the last element of the target path */ char link_target[UTIL_PATH_SIZE]; int len; const char *pos; len = readlink(path_full, link_target, sizeof(link_target)); if (len > 0) { link_target[len] = '\0'; pos = strrchr(link_target, '/'); if (pos != NULL) { dbg(udev, "cache '%s' with link value '%s'\n", path_full, value); util_strlcpy(attr->value_local, &pos[1], sizeof(attr->value_local)); attr->value = attr->value_local; } } goto out; } /* skip directories */ if (S_ISDIR(statbuf.st_mode)) goto out; /* skip non-readable files */ if ((statbuf.st_mode & S_IRUSR) == 0) goto out; /* read attribute value */ fd = open(path_full, O_RDONLY); if (fd < 0) { dbg(udev, "attribute '%s' can not be opened\n", path_full); goto out; } size = read(fd, value, sizeof(value)); close(fd); if (size < 0) goto out; if (size == sizeof(value)) goto out; /* got a valid value, store and return it */ value[size] = '\0'; util_remove_trailing_chars(value, '\n'); dbg(udev, "cache '%s' with attribute value '%s'\n", path_full, value); util_strlcpy(attr->value_local, value, sizeof(attr->value_local)); attr->value = attr->value_local; out: return attr->value; } int sysfs_lookup_devpath_by_subsys_id(struct udev *udev, char *devpath_full, size_t len, const char *subsystem, const char *id) { size_t sysfs_len; char path_full[UTIL_PATH_SIZE]; char *path; struct stat statbuf; sysfs_len = util_strlcpy(path_full, udev_get_sys_path(udev), sizeof(path_full)); path = &path_full[sysfs_len]; if (strcmp(subsystem, "subsystem") == 0) { util_strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len); util_strlcat(path, id, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; util_strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len); util_strlcat(path, id, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; goto out; util_strlcpy(path, "/class/", sizeof(path_full) - sysfs_len); util_strlcat(path, id, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; } if (strcmp(subsystem, "module") == 0) { util_strlcpy(path, "/module/", sizeof(path_full) - sysfs_len); util_strlcat(path, id, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; goto out; } if (strcmp(subsystem, "drivers") == 0) { char subsys[UTIL_NAME_SIZE]; char *driver; util_strlcpy(subsys, id, sizeof(subsys)); driver = strchr(subsys, ':'); if (driver != NULL) { driver[0] = '\0'; driver = &driver[1]; util_strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len); util_strlcat(path, subsys, sizeof(path_full) - sysfs_len); util_strlcat(path, "/drivers/", sizeof(path_full) - sysfs_len); util_strlcat(path, driver, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; util_strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len); util_strlcat(path, subsys, sizeof(path_full) - sysfs_len); util_strlcat(path, "/drivers/", sizeof(path_full) - sysfs_len); util_strlcat(path, driver, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; } goto out; } util_strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len); util_strlcat(path, subsystem, sizeof(path_full) - sysfs_len); util_strlcat(path, "/devices/", sizeof(path_full) - sysfs_len); util_strlcat(path, id, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; util_strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len); util_strlcat(path, subsystem, sizeof(path_full) - sysfs_len); util_strlcat(path, "/devices/", sizeof(path_full) - sysfs_len); util_strlcat(path, id, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; util_strlcpy(path, "/class/", sizeof(path_full) - sysfs_len); util_strlcat(path, subsystem, sizeof(path_full) - sysfs_len); util_strlcat(path, "/", sizeof(path_full) - sysfs_len); util_strlcat(path, id, sizeof(path_full) - sysfs_len); if (stat(path_full, &statbuf) == 0) goto found; out: return 0; found: if (S_ISLNK(statbuf.st_mode)) resolve_sys_link(udev, path, sizeof(path_full) - sysfs_len); util_strlcpy(devpath_full, path, len); return 1; }