| /* |
| * Copyright (C) 2007-2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <dirent.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <fnmatch.h> |
| #include <libgen.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/sendfile.h> |
| #include <sys/socket.h> |
| #include <sys/stat.h> |
| #include <sys/time.h> |
| #include <sys/types.h> |
| #include <sys/un.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #include <linux/netlink.h> |
| |
| #include <memory> |
| #include <thread> |
| |
| #include <selinux/selinux.h> |
| #include <selinux/label.h> |
| #include <selinux/android.h> |
| #include <selinux/avc.h> |
| |
| #include <private/android_filesystem_config.h> |
| |
| #include <android-base/file.h> |
| #include <android-base/stringprintf.h> |
| #include <android-base/unique_fd.h> |
| #include <cutils/list.h> |
| #include <cutils/uevent.h> |
| |
| #include "devices.h" |
| #include "ueventd_parser.h" |
| #include "util.h" |
| #include "log.h" |
| |
| #define SYSFS_PREFIX "/sys" |
| static const char *firmware_dirs[] = { "/etc/firmware", |
| "/vendor/firmware", |
| "/firmware/image" }; |
| |
| extern struct selabel_handle *sehandle; |
| |
| static android::base::unique_fd device_fd; |
| |
| struct perms_ { |
| char *name; |
| char *attr; |
| mode_t perm; |
| unsigned int uid; |
| unsigned int gid; |
| unsigned short prefix; |
| unsigned short wildcard; |
| }; |
| |
| struct perm_node { |
| struct perms_ dp; |
| struct listnode plist; |
| }; |
| |
| struct platform_node { |
| char *name; |
| char *path; |
| int path_len; |
| struct listnode list; |
| }; |
| |
| static list_declare(sys_perms); |
| static list_declare(dev_perms); |
| static list_declare(platform_names); |
| |
| int add_dev_perms(const char *name, const char *attr, |
| mode_t perm, unsigned int uid, unsigned int gid, |
| unsigned short prefix, |
| unsigned short wildcard) { |
| struct perm_node *node = (perm_node*) calloc(1, sizeof(*node)); |
| if (!node) |
| return -ENOMEM; |
| |
| node->dp.name = strdup(name); |
| if (!node->dp.name) { |
| free(node); |
| return -ENOMEM; |
| } |
| |
| if (attr) { |
| node->dp.attr = strdup(attr); |
| if (!node->dp.attr) { |
| free(node->dp.name); |
| free(node); |
| return -ENOMEM; |
| } |
| } |
| |
| node->dp.perm = perm; |
| node->dp.uid = uid; |
| node->dp.gid = gid; |
| node->dp.prefix = prefix; |
| node->dp.wildcard = wildcard; |
| |
| if (attr) |
| list_add_tail(&sys_perms, &node->plist); |
| else |
| list_add_tail(&dev_perms, &node->plist); |
| |
| return 0; |
| } |
| |
| static bool perm_path_matches(const char *path, struct perms_ *dp) |
| { |
| if (dp->prefix) { |
| if (strncmp(path, dp->name, strlen(dp->name)) == 0) |
| return true; |
| } else if (dp->wildcard) { |
| if (fnmatch(dp->name, path, FNM_PATHNAME) == 0) |
| return true; |
| } else { |
| if (strcmp(path, dp->name) == 0) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static bool match_subsystem(perms_* dp, const char* pattern, |
| const char* path, const char* subsystem) { |
| if (!pattern || !subsystem || strstr(dp->name, subsystem) == NULL) { |
| return false; |
| } |
| |
| std::string subsys_path = android::base::StringPrintf(pattern, subsystem, basename(path)); |
| return perm_path_matches(subsys_path.c_str(), dp); |
| } |
| |
| static void fixup_sys_perms(const char* upath, const char* subsystem) { |
| // upaths omit the "/sys" that paths in this list |
| // contain, so we prepend it... |
| std::string path = std::string(SYSFS_PREFIX) + upath; |
| |
| listnode* node; |
| list_for_each(node, &sys_perms) { |
| perms_* dp = &(node_to_item(node, perm_node, plist))->dp; |
| if (match_subsystem(dp, SYSFS_PREFIX "/class/%s/%s", path.c_str(), subsystem)) { |
| ; // matched |
| } else if (match_subsystem(dp, SYSFS_PREFIX "/bus/%s/devices/%s", path.c_str(), subsystem)) { |
| ; // matched |
| } else if (!perm_path_matches(path.c_str(), dp)) { |
| continue; |
| } |
| |
| std::string attr_file = path + "/" + dp->attr; |
| LOG(INFO) << "fixup " << attr_file |
| << " " << dp->uid << " " << dp->gid << " " << std::oct << dp->perm; |
| chown(attr_file.c_str(), dp->uid, dp->gid); |
| chmod(attr_file.c_str(), dp->perm); |
| } |
| |
| if (access(path.c_str(), F_OK) == 0) { |
| LOG(VERBOSE) << "restorecon_recursive: " << path; |
| restorecon(path.c_str(), SELINUX_ANDROID_RESTORECON_RECURSE); |
| } |
| } |
| |
| static mode_t get_device_perm(const char *path, const char **links, |
| unsigned *uid, unsigned *gid) |
| { |
| struct listnode *node; |
| struct perm_node *perm_node; |
| struct perms_ *dp; |
| |
| /* search the perms list in reverse so that ueventd.$hardware can |
| * override ueventd.rc |
| */ |
| list_for_each_reverse(node, &dev_perms) { |
| bool match = false; |
| |
| perm_node = node_to_item(node, struct perm_node, plist); |
| dp = &perm_node->dp; |
| |
| if (perm_path_matches(path, dp)) { |
| match = true; |
| } else { |
| if (links) { |
| int i; |
| for (i = 0; links[i]; i++) { |
| if (perm_path_matches(links[i], dp)) { |
| match = true; |
| break; |
| } |
| } |
| } |
| } |
| |
| if (match) { |
| *uid = dp->uid; |
| *gid = dp->gid; |
| return dp->perm; |
| } |
| } |
| /* Default if nothing found. */ |
| *uid = 0; |
| *gid = 0; |
| return 0600; |
| } |
| |
| static void make_device(const char *path, |
| const char */*upath*/, |
| int block, int major, int minor, |
| const char **links) |
| { |
| unsigned uid; |
| unsigned gid; |
| mode_t mode; |
| dev_t dev; |
| char *secontext = NULL; |
| |
| mode = get_device_perm(path, links, &uid, &gid) | (block ? S_IFBLK : S_IFCHR); |
| |
| if (sehandle) { |
| if (selabel_lookup_best_match(sehandle, &secontext, path, links, mode)) { |
| PLOG(ERROR) << "Device '" << path << "' not created; cannot find SELinux label"; |
| return; |
| } |
| setfscreatecon(secontext); |
| } |
| |
| dev = makedev(major, minor); |
| /* Temporarily change egid to avoid race condition setting the gid of the |
| * device node. Unforunately changing the euid would prevent creation of |
| * some device nodes, so the uid has to be set with chown() and is still |
| * racy. Fixing the gid race at least fixed the issue with system_server |
| * opening dynamic input devices under the AID_INPUT gid. */ |
| if (setegid(gid)) { |
| PLOG(ERROR) << "setegid(" << gid << ") for " << path << " device failed"; |
| goto out; |
| } |
| /* If the node already exists update its SELinux label to handle cases when |
| * it was created with the wrong context during coldboot procedure. */ |
| if (mknod(path, mode, dev) && (errno == EEXIST) && secontext) { |
| |
| char* fcon = nullptr; |
| int rc = lgetfilecon(path, &fcon); |
| if (rc < 0) { |
| PLOG(ERROR) << "Cannot get SELinux label on '" << path << "' device"; |
| goto out; |
| } |
| |
| bool different = strcmp(fcon, secontext) != 0; |
| freecon(fcon); |
| |
| if (different && lsetfilecon(path, secontext)) { |
| PLOG(ERROR) << "Cannot set '" << secontext << "' SELinux label on '" << path << "' device"; |
| } |
| } |
| |
| out: |
| chown(path, uid, -1); |
| if (setegid(AID_ROOT)) { |
| PLOG(FATAL) << "setegid(AID_ROOT) failed"; |
| } |
| |
| if (secontext) { |
| freecon(secontext); |
| setfscreatecon(NULL); |
| } |
| } |
| |
| static void add_platform_device(const char *path) |
| { |
| int path_len = strlen(path); |
| struct platform_node *bus; |
| const char *name = path; |
| |
| if (!strncmp(path, "/devices/", 9)) { |
| name += 9; |
| if (!strncmp(name, "platform/", 9)) |
| name += 9; |
| } |
| |
| LOG(VERBOSE) << "adding platform device " << name << " (" << path << ")"; |
| |
| bus = (platform_node*) calloc(1, sizeof(struct platform_node)); |
| bus->path = strdup(path); |
| bus->path_len = path_len; |
| bus->name = bus->path + (name - path); |
| list_add_tail(&platform_names, &bus->list); |
| } |
| |
| /* |
| * given a path that may start with a platform device, find the length of the |
| * platform device prefix. If it doesn't start with a platform device, return |
| * 0. |
| */ |
| static struct platform_node *find_platform_device(const char *path) |
| { |
| int path_len = strlen(path); |
| struct listnode *node; |
| struct platform_node *bus; |
| |
| list_for_each_reverse(node, &platform_names) { |
| bus = node_to_item(node, struct platform_node, list); |
| if ((bus->path_len < path_len) && |
| (path[bus->path_len] == '/') && |
| !strncmp(path, bus->path, bus->path_len)) |
| return bus; |
| } |
| |
| return NULL; |
| } |
| |
| static void remove_platform_device(const char *path) |
| { |
| struct listnode *node; |
| struct platform_node *bus; |
| |
| list_for_each_reverse(node, &platform_names) { |
| bus = node_to_item(node, struct platform_node, list); |
| if (!strcmp(path, bus->path)) { |
| LOG(INFO) << "removing platform device " << bus->name; |
| free(bus->path); |
| list_remove(node); |
| free(bus); |
| return; |
| } |
| } |
| } |
| |
| static void destroy_platform_devices() { |
| struct listnode* node; |
| struct listnode* n; |
| struct platform_node* bus; |
| |
| list_for_each_safe(node, n, &platform_names) { |
| list_remove(node); |
| bus = node_to_item(node, struct platform_node, list); |
| free(bus->path); |
| free(bus); |
| } |
| } |
| |
| /* Given a path that may start with a PCI device, populate the supplied buffer |
| * with the PCI domain/bus number and the peripheral ID and return 0. |
| * If it doesn't start with a PCI device, or there is some error, return -1 */ |
| static int find_pci_device_prefix(const char *path, char *buf, ssize_t buf_sz) |
| { |
| const char *start, *end; |
| |
| if (strncmp(path, "/devices/pci", 12)) |
| return -1; |
| |
| /* Beginning of the prefix is the initial "pci" after "/devices/" */ |
| start = path + 9; |
| |
| /* End of the prefix is two path '/' later, capturing the domain/bus number |
| * and the peripheral ID. Example: pci0000:00/0000:00:1f.2 */ |
| end = strchr(start, '/'); |
| if (!end) |
| return -1; |
| end = strchr(end + 1, '/'); |
| if (!end) |
| return -1; |
| |
| /* Make sure we have enough room for the string plus null terminator */ |
| if (end - start + 1 > buf_sz) |
| return -1; |
| |
| strncpy(buf, start, end - start); |
| buf[end - start] = '\0'; |
| return 0; |
| } |
| |
| /* Given a path that may start with a virtual block device, populate |
| * the supplied buffer with the virtual block device ID and return 0. |
| * If it doesn't start with a virtual block device, or there is some |
| * error, return -1 */ |
| static int find_vbd_device_prefix(const char *path, char *buf, ssize_t buf_sz) |
| { |
| const char *start, *end; |
| |
| /* Beginning of the prefix is the initial "vbd-" after "/devices/" */ |
| if (strncmp(path, "/devices/vbd-", 13)) |
| return -1; |
| |
| /* End of the prefix is one path '/' later, capturing the |
| virtual block device ID. Example: 768 */ |
| start = path + 13; |
| end = strchr(start, '/'); |
| if (!end) |
| return -1; |
| |
| /* Make sure we have enough room for the string plus null terminator */ |
| if (end - start + 1 > buf_sz) |
| return -1; |
| |
| strncpy(buf, start, end - start); |
| buf[end - start] = '\0'; |
| return 0; |
| } |
| |
| static void parse_event(const char *msg, struct uevent *uevent) |
| { |
| uevent->action = ""; |
| uevent->path = ""; |
| uevent->subsystem = ""; |
| uevent->firmware = ""; |
| uevent->major = -1; |
| uevent->minor = -1; |
| uevent->partition_name = NULL; |
| uevent->partition_num = -1; |
| uevent->device_name = NULL; |
| |
| /* currently ignoring SEQNUM */ |
| while(*msg) { |
| if(!strncmp(msg, "ACTION=", 7)) { |
| msg += 7; |
| uevent->action = msg; |
| } else if(!strncmp(msg, "DEVPATH=", 8)) { |
| msg += 8; |
| uevent->path = msg; |
| } else if(!strncmp(msg, "SUBSYSTEM=", 10)) { |
| msg += 10; |
| uevent->subsystem = msg; |
| } else if(!strncmp(msg, "FIRMWARE=", 9)) { |
| msg += 9; |
| uevent->firmware = msg; |
| } else if(!strncmp(msg, "MAJOR=", 6)) { |
| msg += 6; |
| uevent->major = atoi(msg); |
| } else if(!strncmp(msg, "MINOR=", 6)) { |
| msg += 6; |
| uevent->minor = atoi(msg); |
| } else if(!strncmp(msg, "PARTN=", 6)) { |
| msg += 6; |
| uevent->partition_num = atoi(msg); |
| } else if(!strncmp(msg, "PARTNAME=", 9)) { |
| msg += 9; |
| uevent->partition_name = msg; |
| } else if(!strncmp(msg, "DEVNAME=", 8)) { |
| msg += 8; |
| uevent->device_name = msg; |
| } |
| |
| /* advance to after the next \0 */ |
| while(*msg++) |
| ; |
| } |
| |
| if (LOG_UEVENTS) { |
| LOG(INFO) << android::base::StringPrintf("event { '%s', '%s', '%s', '%s', %d, %d }", |
| uevent->action, uevent->path, uevent->subsystem, |
| uevent->firmware, uevent->major, uevent->minor); |
| } |
| } |
| |
| static char **get_character_device_symlinks(struct uevent *uevent) |
| { |
| const char *parent; |
| const char *slash; |
| char **links; |
| int link_num = 0; |
| int width; |
| struct platform_node *pdev; |
| |
| pdev = find_platform_device(uevent->path); |
| if (!pdev) |
| return NULL; |
| |
| links = (char**) malloc(sizeof(char *) * 2); |
| if (!links) |
| return NULL; |
| memset(links, 0, sizeof(char *) * 2); |
| |
| /* skip "/devices/platform/<driver>" */ |
| parent = strchr(uevent->path + pdev->path_len, '/'); |
| if (!parent) |
| goto err; |
| |
| if (!strncmp(parent, "/usb", 4)) { |
| /* skip root hub name and device. use device interface */ |
| while (*++parent && *parent != '/'); |
| if (*parent) |
| while (*++parent && *parent != '/'); |
| if (!*parent) |
| goto err; |
| slash = strchr(++parent, '/'); |
| if (!slash) |
| goto err; |
| width = slash - parent; |
| if (width <= 0) |
| goto err; |
| |
| if (asprintf(&links[link_num], "/dev/usb/%s%.*s", uevent->subsystem, width, parent) > 0) |
| link_num++; |
| else |
| links[link_num] = NULL; |
| mkdir("/dev/usb", 0755); |
| } |
| else { |
| goto err; |
| } |
| |
| return links; |
| err: |
| free(links); |
| return NULL; |
| } |
| |
| char** get_block_device_symlinks(struct uevent* uevent) { |
| const char *device; |
| struct platform_node *pdev; |
| const char *slash; |
| const char *type; |
| char buf[256]; |
| char link_path[256]; |
| int link_num = 0; |
| char *p; |
| |
| pdev = find_platform_device(uevent->path); |
| if (pdev) { |
| device = pdev->name; |
| type = "platform"; |
| } else if (!find_pci_device_prefix(uevent->path, buf, sizeof(buf))) { |
| device = buf; |
| type = "pci"; |
| } else if (!find_vbd_device_prefix(uevent->path, buf, sizeof(buf))) { |
| device = buf; |
| type = "vbd"; |
| } else { |
| return NULL; |
| } |
| |
| char **links = (char**) malloc(sizeof(char *) * 4); |
| if (!links) |
| return NULL; |
| memset(links, 0, sizeof(char *) * 4); |
| |
| LOG(VERBOSE) << "found " << type << " device " << device; |
| |
| snprintf(link_path, sizeof(link_path), "/dev/block/%s/%s", type, device); |
| |
| if (uevent->partition_name) { |
| p = strdup(uevent->partition_name); |
| sanitize(p); |
| if (strcmp(uevent->partition_name, p)) { |
| LOG(VERBOSE) << "Linking partition '" << uevent->partition_name << "' as '" << p << "'"; |
| } |
| if (asprintf(&links[link_num], "%s/by-name/%s", link_path, p) > 0) |
| link_num++; |
| else |
| links[link_num] = NULL; |
| free(p); |
| } |
| |
| if (uevent->partition_num >= 0) { |
| if (asprintf(&links[link_num], "%s/by-num/p%d", link_path, uevent->partition_num) > 0) |
| link_num++; |
| else |
| links[link_num] = NULL; |
| } |
| |
| slash = strrchr(uevent->path, '/'); |
| if (asprintf(&links[link_num], "%s/%s", link_path, slash + 1) > 0) |
| link_num++; |
| else |
| links[link_num] = NULL; |
| |
| return links; |
| } |
| |
| static void make_link_init(const char* oldpath, const char* newpath) { |
| const char* slash = strrchr(newpath, '/'); |
| if (!slash) return; |
| |
| if (mkdir_recursive(dirname(newpath), 0755)) { |
| PLOG(ERROR) << "Failed to create directory " << dirname(newpath); |
| } |
| |
| if (symlink(oldpath, newpath) && errno != EEXIST) { |
| PLOG(ERROR) << "Failed to symlink " << oldpath << " to " << newpath; |
| } |
| } |
| |
| static void remove_link(const char* oldpath, const char* newpath) { |
| std::string path; |
| if (android::base::Readlink(newpath, &path) && path == oldpath) unlink(newpath); |
| } |
| |
| static void handle_device(const char *action, const char *devpath, |
| const char *path, int block, int major, int minor, char **links) |
| { |
| if(!strcmp(action, "add")) { |
| make_device(devpath, path, block, major, minor, (const char **)links); |
| if (links) { |
| for (int i = 0; links[i]; i++) { |
| make_link_init(devpath, links[i]); |
| } |
| } |
| } |
| |
| if(!strcmp(action, "remove")) { |
| if (links) { |
| for (int i = 0; links[i]; i++) { |
| remove_link(devpath, links[i]); |
| } |
| } |
| unlink(devpath); |
| } |
| |
| if (links) { |
| for (int i = 0; links[i]; i++) { |
| free(links[i]); |
| } |
| free(links); |
| } |
| } |
| |
| static void handle_platform_device_event(struct uevent *uevent) |
| { |
| const char *path = uevent->path; |
| |
| if (!strcmp(uevent->action, "add")) |
| add_platform_device(path); |
| else if (!strcmp(uevent->action, "remove")) |
| remove_platform_device(path); |
| } |
| |
| static const char *parse_device_name(struct uevent *uevent, unsigned int len) |
| { |
| const char *name; |
| |
| /* if it's not a /dev device, nothing else to do */ |
| if((uevent->major < 0) || (uevent->minor < 0)) |
| return NULL; |
| |
| /* do we have a name? */ |
| name = strrchr(uevent->path, '/'); |
| if(!name) |
| return NULL; |
| name++; |
| |
| /* too-long names would overrun our buffer */ |
| if(strlen(name) > len) { |
| LOG(ERROR) << "DEVPATH=" << name << " exceeds " << len << "-character limit on filename; ignoring event"; |
| return NULL; |
| } |
| |
| return name; |
| } |
| |
| #define DEVPATH_LEN 96 |
| #define MAX_DEV_NAME 64 |
| |
| static void handle_block_device_event(struct uevent *uevent) |
| { |
| const char *base = "/dev/block/"; |
| const char *name; |
| char devpath[DEVPATH_LEN]; |
| char **links = NULL; |
| |
| name = parse_device_name(uevent, MAX_DEV_NAME); |
| if (!name) |
| return; |
| |
| snprintf(devpath, sizeof(devpath), "%s%s", base, name); |
| make_dir(base, 0755); |
| |
| if (!strncmp(uevent->path, "/devices/", 9)) |
| links = get_block_device_symlinks(uevent); |
| |
| handle_device(uevent->action, devpath, uevent->path, 1, |
| uevent->major, uevent->minor, links); |
| } |
| |
| static bool assemble_devpath(char *devpath, const char *dirname, |
| const char *devname) |
| { |
| int s = snprintf(devpath, DEVPATH_LEN, "%s/%s", dirname, devname); |
| if (s < 0) { |
| PLOG(ERROR) << "failed to assemble device path; ignoring event"; |
| return false; |
| } else if (s >= DEVPATH_LEN) { |
| LOG(ERROR) << dirname << "/" << devname |
| << " exceeds " << DEVPATH_LEN << "-character limit on path; ignoring event"; |
| return false; |
| } |
| return true; |
| } |
| |
| static void mkdir_recursive_for_devpath(const char *devpath) |
| { |
| char dir[DEVPATH_LEN]; |
| char *slash; |
| |
| strcpy(dir, devpath); |
| slash = strrchr(dir, '/'); |
| *slash = '\0'; |
| mkdir_recursive(dir, 0755); |
| } |
| |
| static void handle_generic_device_event(struct uevent *uevent) |
| { |
| const char *base; |
| const char *name; |
| char devpath[DEVPATH_LEN] = {0}; |
| char **links = NULL; |
| |
| name = parse_device_name(uevent, MAX_DEV_NAME); |
| if (!name) |
| return; |
| |
| struct ueventd_subsystem *subsystem = |
| ueventd_subsystem_find_by_name(uevent->subsystem); |
| |
| if (subsystem) { |
| const char *devname; |
| |
| switch (subsystem->devname_src) { |
| case DEVNAME_UEVENT_DEVNAME: |
| devname = uevent->device_name; |
| break; |
| |
| case DEVNAME_UEVENT_DEVPATH: |
| devname = name; |
| break; |
| |
| default: |
| LOG(ERROR) << uevent->subsystem << " subsystem's devpath option is not set; ignoring event"; |
| return; |
| } |
| |
| if (!assemble_devpath(devpath, subsystem->dirname, devname)) |
| return; |
| mkdir_recursive_for_devpath(devpath); |
| } else if (!strncmp(uevent->subsystem, "usb", 3)) { |
| if (!strcmp(uevent->subsystem, "usb")) { |
| if (uevent->device_name) { |
| if (!assemble_devpath(devpath, "/dev", uevent->device_name)) |
| return; |
| mkdir_recursive_for_devpath(devpath); |
| } |
| else { |
| /* This imitates the file system that would be created |
| * if we were using devfs instead. |
| * Minors are broken up into groups of 128, starting at "001" |
| */ |
| int bus_id = uevent->minor / 128 + 1; |
| int device_id = uevent->minor % 128 + 1; |
| /* build directories */ |
| make_dir("/dev/bus", 0755); |
| make_dir("/dev/bus/usb", 0755); |
| snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d", bus_id); |
| make_dir(devpath, 0755); |
| snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d/%03d", bus_id, device_id); |
| } |
| } else { |
| /* ignore other USB events */ |
| return; |
| } |
| } else if (!strncmp(uevent->subsystem, "graphics", 8)) { |
| base = "/dev/graphics/"; |
| make_dir(base, 0755); |
| } else if (!strncmp(uevent->subsystem, "drm", 3)) { |
| base = "/dev/dri/"; |
| make_dir(base, 0755); |
| } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) { |
| base = "/dev/oncrpc/"; |
| make_dir(base, 0755); |
| } else if (!strncmp(uevent->subsystem, "adsp", 4)) { |
| base = "/dev/adsp/"; |
| make_dir(base, 0755); |
| } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) { |
| base = "/dev/msm_camera/"; |
| make_dir(base, 0755); |
| } else if(!strncmp(uevent->subsystem, "input", 5)) { |
| base = "/dev/input/"; |
| make_dir(base, 0755); |
| } else if(!strncmp(uevent->subsystem, "mtd", 3)) { |
| base = "/dev/mtd/"; |
| make_dir(base, 0755); |
| } else if(!strncmp(uevent->subsystem, "sound", 5)) { |
| base = "/dev/snd/"; |
| make_dir(base, 0755); |
| } else if(!strncmp(uevent->subsystem, "misc", 4) && !strncmp(name, "log_", 4)) { |
| LOG(INFO) << "kernel logger is deprecated"; |
| base = "/dev/log/"; |
| make_dir(base, 0755); |
| name += 4; |
| } else |
| base = "/dev/"; |
| links = get_character_device_symlinks(uevent); |
| |
| if (!devpath[0]) |
| snprintf(devpath, sizeof(devpath), "%s%s", base, name); |
| |
| handle_device(uevent->action, devpath, uevent->path, 0, |
| uevent->major, uevent->minor, links); |
| } |
| |
| static void handle_device_event(struct uevent *uevent) |
| { |
| if (!strcmp(uevent->action,"add") || !strcmp(uevent->action, "change") || !strcmp(uevent->action, "online")) |
| fixup_sys_perms(uevent->path, uevent->subsystem); |
| |
| if (!strncmp(uevent->subsystem, "block", 5)) { |
| handle_block_device_event(uevent); |
| } else if (!strncmp(uevent->subsystem, "platform", 8)) { |
| handle_platform_device_event(uevent); |
| } else { |
| handle_generic_device_event(uevent); |
| } |
| } |
| |
| static void load_firmware(uevent* uevent, const std::string& root, |
| int fw_fd, size_t fw_size, |
| int loading_fd, int data_fd) { |
| // Start transfer. |
| android::base::WriteFully(loading_fd, "1", 1); |
| |
| // Copy the firmware. |
| int rc = sendfile(data_fd, fw_fd, nullptr, fw_size); |
| if (rc == -1) { |
| PLOG(ERROR) << "firmware: sendfile failed { '" << root << "', '" << uevent->firmware << "' }"; |
| } |
| |
| // Tell the firmware whether to abort or commit. |
| const char* response = (rc != -1) ? "0" : "-1"; |
| android::base::WriteFully(loading_fd, response, strlen(response)); |
| } |
| |
| static int is_booting() { |
| return access("/dev/.booting", F_OK) == 0; |
| } |
| |
| static void process_firmware_event(uevent* uevent) { |
| int booting = is_booting(); |
| |
| LOG(INFO) << "firmware: loading '" << uevent->firmware << "' for '" << uevent->path << "'"; |
| |
| std::string root = android::base::StringPrintf("/sys%s", uevent->path); |
| std::string loading = root + "/loading"; |
| std::string data = root + "/data"; |
| |
| android::base::unique_fd loading_fd(open(loading.c_str(), O_WRONLY|O_CLOEXEC)); |
| if (loading_fd == -1) { |
| PLOG(ERROR) << "couldn't open firmware loading fd for " << uevent->firmware; |
| return; |
| } |
| |
| android::base::unique_fd data_fd(open(data.c_str(), O_WRONLY|O_CLOEXEC)); |
| if (data_fd == -1) { |
| PLOG(ERROR) << "couldn't open firmware data fd for " << uevent->firmware; |
| return; |
| } |
| |
| try_loading_again: |
| for (size_t i = 0; i < arraysize(firmware_dirs); i++) { |
| std::string file = android::base::StringPrintf("%s/%s", firmware_dirs[i], uevent->firmware); |
| android::base::unique_fd fw_fd(open(file.c_str(), O_RDONLY|O_CLOEXEC)); |
| struct stat sb; |
| if (fw_fd != -1 && fstat(fw_fd, &sb) != -1) { |
| load_firmware(uevent, root, fw_fd, sb.st_size, loading_fd, data_fd); |
| return; |
| } |
| } |
| |
| if (booting) { |
| // If we're not fully booted, we may be missing |
| // filesystems needed for firmware, wait and retry. |
| std::this_thread::sleep_for(100ms); |
| booting = is_booting(); |
| goto try_loading_again; |
| } |
| |
| LOG(ERROR) << "firmware: could not find firmware for " << uevent->firmware; |
| |
| // Write "-1" as our response to the kernel's firmware request, since we have nothing for it. |
| write(loading_fd, "-1", 2); |
| } |
| |
| static void handle_firmware_event(uevent* uevent) { |
| if (strcmp(uevent->subsystem, "firmware")) return; |
| if (strcmp(uevent->action, "add")) return; |
| |
| // Loading the firmware in a child means we can do that in parallel... |
| // (We ignore SIGCHLD rather than wait for our children.) |
| pid_t pid = fork(); |
| if (pid == 0) { |
| Timer t; |
| process_firmware_event(uevent); |
| LOG(INFO) << "loading " << uevent->path << " took " << t; |
| _exit(EXIT_SUCCESS); |
| } else if (pid == -1) { |
| PLOG(ERROR) << "could not fork to process firmware event for " << uevent->firmware; |
| } |
| } |
| |
| static bool inline should_stop_coldboot(coldboot_action_t act) |
| { |
| return (act == COLDBOOT_STOP || act == COLDBOOT_FINISH); |
| } |
| |
| #define UEVENT_MSG_LEN 2048 |
| |
| static inline coldboot_action_t handle_device_fd_with( |
| std::function<coldboot_action_t(uevent* uevent)> handle_uevent) |
| { |
| char msg[UEVENT_MSG_LEN+2]; |
| int n; |
| while ((n = uevent_kernel_multicast_recv(device_fd, msg, UEVENT_MSG_LEN)) > 0) { |
| if(n >= UEVENT_MSG_LEN) /* overflow -- discard */ |
| continue; |
| |
| msg[n] = '\0'; |
| msg[n+1] = '\0'; |
| |
| struct uevent uevent; |
| parse_event(msg, &uevent); |
| coldboot_action_t act = handle_uevent(&uevent); |
| if (should_stop_coldboot(act)) |
| return act; |
| } |
| |
| return COLDBOOT_CONTINUE; |
| } |
| |
| coldboot_action_t handle_device_fd(coldboot_callback fn) |
| { |
| coldboot_action_t ret = handle_device_fd_with( |
| [&](uevent* uevent) -> coldboot_action_t { |
| if (selinux_status_updated() > 0) { |
| struct selabel_handle *sehandle2; |
| sehandle2 = selinux_android_file_context_handle(); |
| if (sehandle2) { |
| selabel_close(sehandle); |
| sehandle = sehandle2; |
| } |
| } |
| |
| // default is to always create the devices |
| coldboot_action_t act = COLDBOOT_CREATE; |
| if (fn) { |
| act = fn(uevent); |
| } |
| |
| if (act == COLDBOOT_CREATE || act == COLDBOOT_STOP) { |
| handle_device_event(uevent); |
| handle_firmware_event(uevent); |
| } |
| |
| return act; |
| }); |
| |
| return ret; |
| } |
| |
| /* Coldboot walks parts of the /sys tree and pokes the uevent files |
| ** to cause the kernel to regenerate device add events that happened |
| ** before init's device manager was started |
| ** |
| ** We drain any pending events from the netlink socket every time |
| ** we poke another uevent file to make sure we don't overrun the |
| ** socket's buffer. |
| */ |
| |
| static coldboot_action_t do_coldboot(DIR *d, coldboot_callback fn) |
| { |
| struct dirent *de; |
| int dfd, fd; |
| coldboot_action_t act = COLDBOOT_CONTINUE; |
| |
| dfd = dirfd(d); |
| |
| fd = openat(dfd, "uevent", O_WRONLY); |
| if (fd >= 0) { |
| write(fd, "add\n", 4); |
| close(fd); |
| act = handle_device_fd(fn); |
| if (should_stop_coldboot(act)) |
| return act; |
| } |
| |
| while (!should_stop_coldboot(act) && (de = readdir(d))) { |
| DIR *d2; |
| |
| if(de->d_type != DT_DIR || de->d_name[0] == '.') |
| continue; |
| |
| fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY); |
| if(fd < 0) |
| continue; |
| |
| d2 = fdopendir(fd); |
| if(d2 == 0) |
| close(fd); |
| else { |
| act = do_coldboot(d2, fn); |
| closedir(d2); |
| } |
| } |
| |
| // default is always to continue looking for uevents |
| return act; |
| } |
| |
| static coldboot_action_t coldboot(const char *path, coldboot_callback fn) |
| { |
| std::unique_ptr<DIR, decltype(&closedir)> d(opendir(path), closedir); |
| if (d) { |
| return do_coldboot(d.get(), fn); |
| } |
| |
| return COLDBOOT_CONTINUE; |
| } |
| |
| void device_init(const char* path, coldboot_callback fn) { |
| if (!sehandle) { |
| sehandle = selinux_android_file_context_handle(); |
| } |
| // open uevent socket and selinux status only if it hasn't been |
| // done before |
| if (device_fd == -1) { |
| /* is 256K enough? udev uses 16MB! */ |
| device_fd.reset(uevent_open_socket(256 * 1024, true)); |
| if (device_fd == -1) { |
| return; |
| } |
| fcntl(device_fd, F_SETFL, O_NONBLOCK); |
| selinux_status_open(true); |
| } |
| |
| if (access(COLDBOOT_DONE, F_OK) == 0) { |
| LOG(VERBOSE) << "Skipping coldboot, already done!"; |
| return; |
| } |
| |
| Timer t; |
| coldboot_action_t act; |
| if (!path) { |
| act = coldboot("/sys/class", fn); |
| if (!should_stop_coldboot(act)) { |
| act = coldboot("/sys/block", fn); |
| if (!should_stop_coldboot(act)) { |
| act = coldboot("/sys/devices", fn); |
| } |
| } |
| } else { |
| act = coldboot(path, fn); |
| } |
| |
| // If we have a callback, then do as it says. If no, then the default is |
| // to always create COLDBOOT_DONE file. |
| if (!fn || (act == COLDBOOT_FINISH)) { |
| close(open(COLDBOOT_DONE, O_WRONLY|O_CREAT|O_CLOEXEC, 0000)); |
| } |
| |
| LOG(INFO) << "Coldboot took " << t; |
| } |
| |
| void device_close() { |
| destroy_platform_devices(); |
| device_fd.reset(); |
| selinux_status_close(); |
| } |
| |
| int get_device_fd() { |
| return device_fd; |
| } |
