X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev_sysfs.c;h=7431dd6111692ec0afcd73ff2af56626a6b43747;hp=0b7561f0eba7beb3db5e484cd9376b83e3320f05;hb=2658afdcf147afd384e27f0ac9019e27de7ba397;hpb=492e76c9c1108a28eae356cc8bd7955ccf234980 diff --git a/udev_sysfs.c b/udev_sysfs.c index 0b7561f0e..7431dd611 100644 --- a/udev_sysfs.c +++ b/udev_sysfs.c @@ -112,6 +112,38 @@ void sysfs_device_set_values(struct sysfs_device *dev, const char *devpath, dbg("kernel_number='%s'", dev->kernel_number); } +int sysfs_resolve_link(char *devpath, size_t size) +{ + char link_path[PATH_SIZE]; + char link_target[PATH_SIZE]; + int len; + int i; + int back; + + strlcpy(link_path, sysfs_path, sizeof(link_path)); + strlcat(link_path, devpath, sizeof(link_path)); + len = readlink(link_path, link_target, sizeof(link_target)); + if (len <= 0) + return -1; + link_target[len] = '\0'; + dbg("path link '%s' points to '%s'", devpath, link_target); + + for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++) + ; + dbg("base '%s', tail '%s', back %i", devpath, &link_target[back * 3], back); + for (i = 0; i <= back; i++) { + char *pos = strrchr(devpath, '/'); + + if (pos == NULL) + return -1; + pos[0] = '\0'; + } + dbg("after moving back '%s'", devpath); + strlcat(devpath, "/", size); + strlcat(devpath, &link_target[back * 3], size); + return 0; +} + struct sysfs_device *sysfs_device_get(const char *devpath) { char path[PATH_SIZE]; @@ -144,27 +176,8 @@ struct sysfs_device *sysfs_device_get(const char *devpath) return NULL; } if (S_ISLNK(statbuf.st_mode)) { - int i; - int back; - - len = readlink(path, link_target, sizeof(link_target)); - if (len <= 0) + if (sysfs_resolve_link(devpath_real, sizeof(devpath_real)) != 0) return NULL; - link_target[len] = '\0'; - dbg("devpath link '%s' points to '%s'", path, link_target); - - for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++) - ; - dbg("base '%s', tail '%s', back %i", devpath_real, &link_target[back * 3], back); - for (i = 0; i <= back; i++) { - pos = strrchr(devpath_real, '/'); - if (pos == NULL) - return NULL; - pos[0] = '\0'; - } - dbg("after moving back '%s'", devpath_real); - strlcat(devpath_real, "/", sizeof(devpath_real)); - strlcat(devpath_real, &link_target[back * 3], sizeof(devpath_real)); /* now look for device in cache after path translation */ list_for_each_entry(dev_loop, &dev_list, node) { @@ -184,8 +197,20 @@ struct sysfs_device *sysfs_device_get(const char *devpath) sysfs_device_set_values(dev, devpath_real, NULL, NULL); - /* get subsystem */ - if (strncmp(dev->devpath, "/class/", 7) == 0) { + /* get subsystem name */ + strlcpy(link_path, sysfs_path, sizeof(link_path)); + strlcat(link_path, dev->devpath, sizeof(link_path)); + 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("subsystem link '%s' points to '%s'", link_path, link_target); + pos = strrchr(link_target, '/'); + if (pos != NULL) + strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem)); + } else if (strncmp(dev->devpath, "/class/", 7) == 0) { + /* get subsystem from class dir */ strlcpy(dev->subsystem, &dev->devpath[7], sizeof(dev->subsystem)); pos = strchr(dev->subsystem, '/'); if (pos != NULL) @@ -206,38 +231,26 @@ struct sysfs_device *sysfs_device_get(const char *devpath) pos = strrchr(link_target, '/'); if (pos != NULL) strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem)); - } else { - /* get subsystem from "subsystem" link */ - strlcpy(link_path, sysfs_path, sizeof(link_path)); - strlcat(link_path, dev->devpath, sizeof(link_path)); - strlcat(link_path, "/subsystem", sizeof(link_path)); - len = readlink(link_path, link_target, sizeof(link_target)); - if (len > 0) { - link_target[len] = '\0'; - dbg("subsystem link '%s' points to '%s'", link_path, link_target); - pos = strrchr(link_target, '/'); - if (pos != NULL) - strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem)); - } - } - /* get driver name */ - strlcpy(link_path, sysfs_path, sizeof(link_path)); - strlcat(link_path, dev->devpath, sizeof(link_path)); - strlcat(link_path, "/driver", sizeof(link_path)); - len = readlink(link_path, link_target, sizeof(link_target)); - if (len > 0) { - link_target[len] = '\0'; - dbg("driver link '%s' points to '%s'", link_path, link_target); - pos = strrchr(link_target, '/'); - if (pos != NULL) - strlcpy(dev->driver, &pos[1], sizeof(dev->driver)); } - } else if (strncmp(dev->devpath, "/bus/", 5) == 0 && strstr(dev->devpath, "/drivers/")) { + } else if (strstr(dev->devpath, "/drivers/") != NULL) { strlcpy(dev->subsystem, "drivers", sizeof(dev->subsystem)); } else if (strncmp(dev->devpath, "/module/", 8) == 0) { strlcpy(dev->subsystem, "module", sizeof(dev->subsystem)); } + /* get driver name */ + strlcpy(link_path, sysfs_path, sizeof(link_path)); + strlcat(link_path, dev->devpath, sizeof(link_path)); + strlcat(link_path, "/driver", sizeof(link_path)); + len = readlink(link_path, link_target, sizeof(link_target)); + if (len > 0) { + link_target[len] = '\0'; + dbg("driver link '%s' points to '%s'", link_path, link_target); + pos = strrchr(link_target, '/'); + if (pos != NULL) + strlcpy(dev->driver, &pos[1], sizeof(dev->driver)); + } + dbg("add to cache 'devpath=%s', subsystem='%s', driver='%s'", dev->devpath, dev->subsystem, dev->driver); list_add(&dev->node, &dev_list); @@ -247,12 +260,7 @@ struct sysfs_device *sysfs_device_get(const char *devpath) struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev) { char parent_devpath[PATH_SIZE]; - char device_link[PATH_SIZE]; - char device_link_target[PATH_SIZE]; char *pos; - int i; - int len; - int back; dbg("open '%s'", dev->devpath); @@ -262,6 +270,7 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev) /* requesting a parent is only valid for devices */ if ((strncmp(dev->devpath, "/devices/", 9) != 0) && + (strncmp(dev->devpath, "/subsystem/", 11) != 0) && (strncmp(dev->devpath, "/class/", 7) != 0) && (strncmp(dev->devpath, "/block/", 7) != 0)) return NULL; @@ -281,10 +290,13 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev) return NULL; } - /* at the top level of class/block we want to follow the "device" link */ - if (strcmp(parent_devpath, "/block") == 0) { - dbg("/block top level, look for device link"); - goto device_link; + /* at the subsystems top level we want to follow the old-style "device" link */ + if (strncmp(parent_devpath, "/subsystem", 10) == 0) { + pos = strrchr(parent_devpath, '/'); + if (pos == &parent_devpath[10] || pos == parent_devpath || strcmp(pos, "/devices") == 0) { + dbg("/subsystem top level, look for device link"); + goto device_link; + } } if (strncmp(parent_devpath, "/class", 6) == 0) { pos = strrchr(parent_devpath, '/'); @@ -293,33 +305,20 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev) goto device_link; } } + if (strcmp(parent_devpath, "/block") == 0) { + dbg("/block top level, look for device link"); + goto device_link; + } + /* get parent and remember it */ dev->parent = sysfs_device_get(parent_devpath); return dev->parent; device_link: - strlcpy(device_link, sysfs_path, sizeof(device_link)); - strlcat(device_link, dev->devpath, sizeof(device_link)); - strlcat(device_link, "/device", sizeof(device_link)); - len = readlink(device_link, device_link_target, sizeof(device_link_target)); - if (len < 0) - return NULL; - device_link_target[len] = '\0'; - dbg("device link '%s' points to '%s'", device_link, device_link_target); - - for (back = 0; strncmp(&device_link_target[back * 3], "../", 3) == 0; back++) - ; strlcpy(parent_devpath, dev->devpath, sizeof(parent_devpath)); - dbg("base='%s', tail='%s', back=%i", parent_devpath, &device_link_target[back * 3], back); - for (i = 0; i < back; i++) { - pos = strrchr(parent_devpath, '/'); - if (pos == NULL) - return NULL; - pos[0] = '\0'; - } - dbg("after moving back '%s'", parent_devpath); - strlcat(parent_devpath, "/", sizeof(parent_devpath)); - strlcat(parent_devpath, &device_link_target[back * 3], sizeof(parent_devpath)); + strlcat(parent_devpath, "/device", sizeof(parent_devpath)); + if (sysfs_resolve_link(parent_devpath, sizeof(parent_devpath)) != 0) + return NULL; /* get parent and remember it */ dev->parent = sysfs_device_get(parent_devpath);