| /* |
| * 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 "devices.h" |
| |
| #include <dirent.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <fnmatch.h> |
| #include <grp.h> |
| #include <libgen.h> |
| #include <linux/netlink.h> |
| #include <pwd.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/sendfile.h> |
| #include <sys/socket.h> |
| #include <sys/time.h> |
| #include <sys/un.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #include <algorithm> |
| #include <memory> |
| #include <thread> |
| |
| #include <android-base/file.h> |
| #include <android-base/logging.h> |
| #include <android-base/stringprintf.h> |
| #include <android-base/strings.h> |
| #include <android-base/unique_fd.h> |
| #include <cutils/uevent.h> |
| #include <private/android_filesystem_config.h> |
| #include <selinux/android.h> |
| #include <selinux/avc.h> |
| #include <selinux/label.h> |
| #include <selinux/selinux.h> |
| |
| #include "keyword_map.h" |
| #include "ueventd.h" |
| #include "util.h" |
| |
| extern struct selabel_handle *sehandle; |
| |
| static android::base::unique_fd device_fd; |
| |
| Permissions::Permissions(const std::string& name, mode_t perm, uid_t uid, gid_t gid) |
| : name_(name), perm_(perm), uid_(uid), gid_(gid), prefix_(false), wildcard_(false) { |
| // If the first * is the last character, then we'll treat name_ as a prefix |
| // Otherwise, if a * is present, then we do a full fnmatch(). |
| auto wildcard_position = name_.find('*'); |
| if (wildcard_position == name_.length() - 1) { |
| prefix_ = true; |
| name_.pop_back(); |
| } else if (wildcard_position != std::string::npos) { |
| wildcard_ = true; |
| } |
| } |
| |
| bool Permissions::Match(const std::string& path) const { |
| if (prefix_) { |
| return android::base::StartsWith(path, name_.c_str()); |
| } else if (wildcard_) { |
| return fnmatch(name_.c_str(), path.c_str(), FNM_PATHNAME) == 0; |
| } else { |
| return path == name_; |
| } |
| |
| return false; |
| } |
| |
| bool SysfsPermissions::MatchWithSubsystem(const std::string& path, |
| const std::string& subsystem) const { |
| std::string path_basename = android::base::Basename(path); |
| if (name().find(subsystem) != std::string::npos) { |
| if (Match("/sys/class/" + subsystem + "/" + path_basename)) return true; |
| if (Match("/sys/bus/" + subsystem + "/devices/" + path_basename)) return true; |
| } |
| return Match(path); |
| } |
| |
| void SysfsPermissions::SetPermissions(const std::string& path) const { |
| std::string attribute_file = path + "/" + attribute_; |
| LOG(INFO) << "fixup " << attribute_file << " " << uid() << " " << gid() << " " << std::oct |
| << perm(); |
| chown(attribute_file.c_str(), uid(), gid()); |
| chmod(attribute_file.c_str(), perm()); |
| } |
| |
| // TODO: Move these to be member variables of a future devices class. |
| std::vector<Permissions> dev_permissions; |
| std::vector<SysfsPermissions> sysfs_permissions; |
| |
| bool ParsePermissionsLine(std::vector<std::string>&& args, std::string* err, bool is_sysfs) { |
| if (is_sysfs && args.size() != 5) { |
| *err = "/sys/ lines must have 5 entries"; |
| return false; |
| } |
| |
| if (!is_sysfs && args.size() != 4) { |
| *err = "/dev/ lines must have 4 entries"; |
| return false; |
| } |
| |
| auto it = args.begin(); |
| const std::string& name = *it++; |
| |
| std::string sysfs_attribute; |
| if (is_sysfs) sysfs_attribute = *it++; |
| |
| // args is now common to both sys and dev entries and contains: <perm> <uid> <gid> |
| std::string& perm_string = *it++; |
| char* end_pointer = 0; |
| mode_t perm = strtol(perm_string.c_str(), &end_pointer, 8); |
| if (end_pointer == nullptr || *end_pointer != '\0') { |
| *err = "invalid mode '" + perm_string + "'"; |
| return false; |
| } |
| |
| std::string& uid_string = *it++; |
| passwd* pwd = getpwnam(uid_string.c_str()); |
| if (!pwd) { |
| *err = "invalid uid '" + uid_string + "'"; |
| return false; |
| } |
| uid_t uid = pwd->pw_uid; |
| |
| std::string& gid_string = *it++; |
| struct group* grp = getgrnam(gid_string.c_str()); |
| if (!grp) { |
| *err = "invalid gid '" + gid_string + "'"; |
| return false; |
| } |
| gid_t gid = grp->gr_gid; |
| |
| if (is_sysfs) { |
| sysfs_permissions.emplace_back(name, sysfs_attribute, perm, uid, gid); |
| } else { |
| dev_permissions.emplace_back(name, perm, uid, gid); |
| } |
| return true; |
| } |
| |
| // TODO: Move this to be a member variable of a future devices class. |
| static std::vector<Subsystem> subsystems; |
| |
| std::string Subsystem::ParseDevPath(uevent* uevent) const { |
| std::string devname = devname_source_ == DevnameSource::DEVNAME_UEVENT_DEVNAME |
| ? uevent->device_name |
| : android::base::Basename(uevent->path); |
| |
| return dir_name_ + "/" + devname; |
| } |
| |
| bool SubsystemParser::ParseSection(std::vector<std::string>&& args, const std::string& filename, |
| int line, std::string* err) { |
| if (args.size() != 2) { |
| *err = "subsystems must have exactly one name"; |
| return false; |
| } |
| |
| if (std::find(subsystems.begin(), subsystems.end(), args[1]) != subsystems.end()) { |
| *err = "ignoring duplicate subsystem entry"; |
| return false; |
| } |
| |
| subsystem_.name_ = args[1]; |
| |
| return true; |
| } |
| |
| bool SubsystemParser::ParseDevName(std::vector<std::string>&& args, std::string* err) { |
| if (args[1] == "uevent_devname") { |
| subsystem_.devname_source_ = Subsystem::DevnameSource::DEVNAME_UEVENT_DEVNAME; |
| return true; |
| } |
| if (args[1] == "uevent_devpath") { |
| subsystem_.devname_source_ = Subsystem::DevnameSource::DEVNAME_UEVENT_DEVPATH; |
| return true; |
| } |
| |
| *err = "invalid devname '" + args[1] + "'"; |
| return false; |
| } |
| |
| bool SubsystemParser::ParseDirName(std::vector<std::string>&& args, std::string* err) { |
| if (args[1].front() != '/') { |
| *err = "dirname '" + args[1] + " ' does not start with '/'"; |
| return false; |
| } |
| |
| subsystem_.dir_name_ = args[1]; |
| return true; |
| } |
| |
| bool SubsystemParser::ParseLineSection(std::vector<std::string>&& args, int line, std::string* err) { |
| using OptionParser = |
| bool (SubsystemParser::*)(std::vector<std::string> && args, std::string * err); |
| static class OptionParserMap : public KeywordMap<OptionParser> { |
| private: |
| const Map& map() const override { |
| // clang-format off |
| static const Map option_parsers = { |
| {"devname", {1, 1, &SubsystemParser::ParseDevName}}, |
| {"dirname", {1, 1, &SubsystemParser::ParseDirName}}, |
| }; |
| // clang-format on |
| return option_parsers; |
| } |
| } parser_map; |
| |
| auto parser = parser_map.FindFunction(args, err); |
| |
| if (!parser) { |
| return false; |
| } |
| |
| return (this->*parser)(std::move(args), err); |
| } |
| |
| void SubsystemParser::EndSection() { |
| subsystems.emplace_back(std::move(subsystem_)); |
| } |
| |
| static void fixup_sys_permissions(const std::string& upath, const std::string& subsystem) { |
| // upaths omit the "/sys" that paths in this list |
| // contain, so we prepend it... |
| std::string path = "/sys" + upath; |
| |
| for (const auto& s : sysfs_permissions) { |
| if (s.MatchWithSubsystem(path, subsystem)) s.SetPermissions(path); |
| } |
| |
| if (access(path.c_str(), F_OK) == 0) { |
| LOG(VERBOSE) << "restorecon_recursive: " << path; |
| restorecon(path.c_str(), SELINUX_ANDROID_RESTORECON_RECURSE); |
| } |
| } |
| |
| static std::tuple<mode_t, uid_t, gid_t> get_device_permissions( |
| const std::string& path, const std::vector<std::string>& links) { |
| // Search the perms list in reverse so that ueventd.$hardware can override ueventd.rc. |
| for (auto it = dev_permissions.rbegin(); it != dev_permissions.rend(); ++it) { |
| if (it->Match(path) || std::any_of(links.begin(), links.end(), |
| [it](const auto& link) { return it->Match(link); })) { |
| return {it->perm(), it->uid(), it->gid()}; |
| } |
| } |
| /* Default if nothing found. */ |
| return {0600, 0, 0}; |
| } |
| |
| static void make_device(const std::string& path, int block, int major, int minor, |
| const std::vector<std::string>& links) { |
| dev_t dev; |
| char *secontext = NULL; |
| |
| auto [mode, uid, gid] = get_device_permissions(path, links); |
| mode |= (block ? S_IFBLK : S_IFCHR); |
| |
| if (sehandle) { |
| std::vector<const char*> c_links; |
| for (const auto& link : links) { |
| c_links.emplace_back(link.c_str()); |
| } |
| c_links.emplace_back(nullptr); |
| if (selabel_lookup_best_match(sehandle, &secontext, path.c_str(), &c_links[0], 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.c_str(), mode, dev) && (errno == EEXIST) && secontext) { |
| char* fcon = nullptr; |
| int rc = lgetfilecon(path.c_str(), &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.c_str(), secontext)) { |
| PLOG(ERROR) << "Cannot set '" << secontext << "' SELinux label on '" << path << "' device"; |
| } |
| } |
| |
| out: |
| chown(path.c_str(), uid, -1); |
| if (setegid(AID_ROOT)) { |
| PLOG(FATAL) << "setegid(AID_ROOT) failed"; |
| } |
| |
| if (secontext) { |
| freecon(secontext); |
| setfscreatecon(NULL); |
| } |
| } |
| |
| // TODO: Move this to be a member variable of a future devices class. |
| std::vector<std::string> platform_devices; |
| |
| // 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 false |
| bool find_platform_device(const std::string& path, std::string* out_path) { |
| out_path->clear(); |
| // platform_devices is searched backwards, since parents are added before their children, |
| // and we want to match as deep of a child as we can. |
| for (auto it = platform_devices.rbegin(); it != platform_devices.rend(); ++it) { |
| auto platform_device_path_length = it->length(); |
| if (platform_device_path_length < path.length() && |
| path[platform_device_path_length] == '/' && |
| android::base::StartsWith(path, it->c_str())) { |
| *out_path = *it; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /* 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 bool find_pci_device_prefix(const std::string& path, std::string* result) { |
| result->clear(); |
| |
| if (!android::base::StartsWith(path, "/devices/pci")) return false; |
| |
| /* Beginning of the prefix is the initial "pci" after "/devices/" */ |
| std::string::size_type start = 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 */ |
| auto end = path.find('/', start); |
| if (end == std::string::npos) return false; |
| |
| end = path.find('/', end + 1); |
| if (end == std::string::npos) return false; |
| |
| auto length = end - start; |
| if (length <= 4) { |
| // The minimum string that will get to this check is 'pci/', which is malformed, |
| // so return false |
| return false; |
| } |
| |
| *result = path.substr(start, length); |
| return true; |
| } |
| |
| /* 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 bool find_vbd_device_prefix(const std::string& path, std::string* result) { |
| result->clear(); |
| |
| if (!android::base::StartsWith(path, "/devices/vbd-")) return false; |
| |
| /* Beginning of the prefix is the initial "vbd-" after "/devices/" */ |
| std::string::size_type start = 13; |
| |
| /* End of the prefix is one path '/' later, capturing the |
| virtual block device ID. Example: 768 */ |
| auto end = path.find('/', start); |
| if (end == std::string::npos) return false; |
| |
| auto length = end - start; |
| if (length == 0) return false; |
| |
| *result = path.substr(start, length); |
| return true; |
| } |
| |
| void parse_event(const char* msg, uevent* uevent) { |
| uevent->partition_num = -1; |
| uevent->major = -1; |
| uevent->minor = -1; |
| // 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) << "event { '" << uevent->action << "', '" << uevent->path << "', '" |
| << uevent->subsystem << "', '" << uevent->firmware << "', " << uevent->major |
| << ", " << uevent->minor << " }"; |
| } |
| } |
| |
| std::vector<std::string> get_character_device_symlinks(uevent* uevent) { |
| std::string parent_device; |
| if (!find_platform_device(uevent->path, &parent_device)) return {}; |
| |
| // skip path to the parent driver |
| std::string path = uevent->path.substr(parent_device.length()); |
| |
| if (!android::base::StartsWith(path, "/usb")) return {}; |
| |
| // skip root hub name and device. use device interface |
| // skip 3 slashes, including the first / by starting the search at the 1st character, not 0th. |
| // then extract what comes between the 3rd and 4th slash |
| // e.g. "/usb/usb_device/name/tty2-1:1.0" -> "name" |
| |
| std::string::size_type start = 0; |
| start = path.find('/', start + 1); |
| if (start == std::string::npos) return {}; |
| |
| start = path.find('/', start + 1); |
| if (start == std::string::npos) return {}; |
| |
| auto end = path.find('/', start + 1); |
| if (end == std::string::npos) return {}; |
| |
| start++; // Skip the first '/' |
| |
| auto length = end - start; |
| if (length == 0) return {}; |
| |
| auto name_string = path.substr(start, length); |
| |
| std::vector<std::string> links; |
| links.emplace_back("/dev/usb/" + uevent->subsystem + name_string); |
| |
| mkdir("/dev/usb", 0755); |
| |
| return links; |
| } |
| |
| // replaces any unacceptable characters with '_', the |
| // length of the resulting string is equal to the input string |
| void sanitize_partition_name(std::string* string) { |
| const char* accept = |
| "abcdefghijklmnopqrstuvwxyz" |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZ" |
| "0123456789" |
| "_-."; |
| |
| if (!string) return; |
| |
| std::string::size_type pos = 0; |
| while ((pos = string->find_first_not_of(accept, pos)) != std::string::npos) { |
| (*string)[pos] = '_'; |
| } |
| } |
| |
| std::vector<std::string> get_block_device_symlinks(uevent* uevent) { |
| std::string device; |
| std::string type; |
| |
| if (find_platform_device(uevent->path, &device)) { |
| // Skip /devices/platform or /devices/ if present |
| static const std::string devices_platform_prefix = "/devices/platform/"; |
| static const std::string devices_prefix = "/devices/"; |
| |
| if (android::base::StartsWith(device, devices_platform_prefix.c_str())) { |
| device = device.substr(devices_platform_prefix.length()); |
| } else if (android::base::StartsWith(device, devices_prefix.c_str())) { |
| device = device.substr(devices_prefix.length()); |
| } |
| |
| type = "platform"; |
| } else if (find_pci_device_prefix(uevent->path, &device)) { |
| type = "pci"; |
| } else if (find_vbd_device_prefix(uevent->path, &device)) { |
| type = "vbd"; |
| } else { |
| return {}; |
| } |
| |
| std::vector<std::string> links; |
| |
| LOG(VERBOSE) << "found " << type << " device " << device; |
| |
| auto link_path = "/dev/block/" + type + "/" + device; |
| |
| if (!uevent->partition_name.empty()) { |
| std::string partition_name_sanitized(uevent->partition_name); |
| sanitize_partition_name(&partition_name_sanitized); |
| if (partition_name_sanitized != uevent->partition_name) { |
| LOG(VERBOSE) << "Linking partition '" << uevent->partition_name << "' as '" |
| << partition_name_sanitized << "'"; |
| } |
| links.emplace_back(link_path + "/by-name/" + partition_name_sanitized); |
| } |
| |
| if (uevent->partition_num >= 0) { |
| links.emplace_back(link_path + "/by-num/p" + std::to_string(uevent->partition_num)); |
| } |
| |
| auto last_slash = uevent->path.rfind('/'); |
| links.emplace_back(link_path + "/" + uevent->path.substr(last_slash + 1)); |
| |
| return links; |
| } |
| |
| static void make_link_init(const std::string& oldpath, const std::string& newpath) { |
| if (mkdir_recursive(dirname(newpath.c_str()), 0755)) { |
| PLOG(ERROR) << "Failed to create directory " << dirname(newpath.c_str()); |
| } |
| |
| if (symlink(oldpath.c_str(), newpath.c_str()) && errno != EEXIST) { |
| PLOG(ERROR) << "Failed to symlink " << oldpath << " to " << newpath; |
| } |
| } |
| |
| static void remove_link(const std::string& oldpath, const std::string& newpath) { |
| std::string path; |
| if (android::base::Readlink(newpath, &path) && path == oldpath) unlink(newpath.c_str()); |
| } |
| |
| static void handle_device(const std::string& action, const std::string& devpath, int block, |
| int major, int minor, const std::vector<std::string>& links) { |
| if (action == "add") { |
| make_device(devpath, block, major, minor, links); |
| for (const auto& link : links) { |
| make_link_init(devpath, link); |
| } |
| } |
| |
| if (action == "remove") { |
| for (const auto& link : links) { |
| remove_link(devpath, link); |
| } |
| unlink(devpath.c_str()); |
| } |
| } |
| |
| void handle_platform_device_event(uevent* uevent) { |
| if (uevent->action == "add") { |
| platform_devices.emplace_back(uevent->path); |
| } else if (uevent->action == "remove") { |
| auto it = std::find(platform_devices.begin(), platform_devices.end(), uevent->path); |
| if (it != platform_devices.end()) platform_devices.erase(it); |
| } |
| } |
| |
| static void handle_block_device_event(uevent* uevent) { |
| // if it's not a /dev device, nothing to do |
| if (uevent->major < 0 || uevent->minor < 0) return; |
| |
| const char* base = "/dev/block/"; |
| make_dir(base, 0755); |
| |
| std::string name = android::base::Basename(uevent->path); |
| std::string devpath = base + name; |
| |
| std::vector<std::string> links; |
| if (android::base::StartsWith(uevent->path, "/devices")) { |
| links = get_block_device_symlinks(uevent); |
| } |
| |
| handle_device(uevent->action, devpath, 1, uevent->major, uevent->minor, links); |
| } |
| |
| static void handle_generic_device_event(uevent* uevent) { |
| // if it's not a /dev device, nothing to do |
| if (uevent->major < 0 || uevent->minor < 0) return; |
| |
| std::string devpath; |
| |
| if (android::base::StartsWith(uevent->subsystem, "usb")) { |
| if (uevent->subsystem == "usb") { |
| if (!uevent->device_name.empty()) { |
| devpath = "/dev/" + uevent->device_name; |
| } 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; |
| devpath = android::base::StringPrintf("/dev/bus/usb/%03d/%03d", bus_id, device_id); |
| } |
| } else { |
| // ignore other USB events |
| return; |
| } |
| } else if (auto subsystem = std::find(subsystems.begin(), subsystems.end(), uevent->subsystem); |
| subsystem != subsystems.end()) { |
| devpath = subsystem->ParseDevPath(uevent); |
| } else { |
| devpath = "/dev/" + android::base::Basename(uevent->path); |
| } |
| |
| mkdir_recursive(android::base::Dirname(devpath), 0755); |
| |
| auto links = get_character_device_symlinks(uevent); |
| |
| handle_device(uevent->action, devpath, 0, uevent->major, uevent->minor, links); |
| } |
| |
| static void handle_device_event(struct uevent *uevent) |
| { |
| if (uevent->action == "add" || uevent->action == "change" || uevent->action == "online") { |
| fixup_sys_permissions(uevent->path, uevent->subsystem); |
| } |
| |
| if (uevent->subsystem == "block") { |
| handle_block_device_event(uevent); |
| } else if (uevent->subsystem == "platform") { |
| 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 = "/sys" + 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; |
| } |
| |
| static const char* firmware_dirs[] = {"/etc/firmware/", "/vendor/firmware/", |
| "/firmware/image/"}; |
| |
| try_loading_again: |
| for (size_t i = 0; i < arraysize(firmware_dirs); i++) { |
| std::string file = 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 (uevent->subsystem != "firmware" || 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'; |
| |
| 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() { |
| platform_devices.clear(); |
| device_fd.reset(); |
| selinux_status_close(); |
| } |
| |
| int get_device_fd() { |
| return device_fd; |
| } |