ueventd: Break devices.cpp into discrete classes

devices.cpp handles too many things for creating one class.  This
change breaks it up into various files and classes.

* Parsing is moved to ueventd_parser.cpp
* Reading from the uevent socket and Cold booting is moved to a
  UeventListener class, in uevent_listener.cpp
* Firmware handling is moved to firmware_handler.cpp
* The remaining contents form a DeviceHandler class within devices.cpp

Bug: 33785894

Test: boot bullhead x40, observe no major differences in /dev and /sys
Test: boot sailfish x40, observe no major differences in /dev and /sys
Test: init unit tests

Change-Id: I846a2e5995fbb344c7a8e349065c18a934fa6aba

1 files changed, 145 insertions, 0 deletions

diff --git a/init/ueventd_parser.cpp b/init/ueventd_parser.cpp
new file mode 100644
index 000000000..7156e766f
--- /dev/null
+++ b/init/ueventd_parser.cpp
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2017 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 "ueventd_parser.h"
+
+#include <grp.h>
+#include <pwd.h>
+
+#include "keyword_map.h"
+
+bool ParsePermissionsLine(std::vector<std::string>&& args, std::string* err,
+                          std::vector<SysfsPermissions>* out_sysfs_permissions,
+                          std::vector<Permissions>* out_dev_permissions) {
+    bool is_sysfs = out_sysfs_permissions != nullptr;
+    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) {
+        out_sysfs_permissions->emplace_back(name, sysfs_attribute, perm, uid, gid);
+    } else {
+        out_dev_permissions->emplace_back(name, perm, uid, gid);
+    }
+    return true;
+}
+
+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_));
+}