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, 116 insertions, 0 deletions

diff --git a/init/firmware_handler.cpp b/init/firmware_handler.cpp
new file mode 100644
index 000000000..1471aeb47
--- /dev/null
+++ b/init/firmware_handler.cpp
@@ -0,0 +1,116 @@
+/*
+ * 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 "firmware_handler.h"
+
+#include <fcntl.h>
+#include <sys/sendfile.h>
+#include <unistd.h>
+
+#include <string>
+#include <thread>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+
+#include "util.h"
+
+static void LoadFirmware(const 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 bool IsBooting() {
+    return access("/dev/.booting", F_OK) == 0;
+}
+
+static void ProcessFirmwareEvent(const Uevent& uevent) {
+    int booting = IsBooting();
+
+    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) {
+            LoadFirmware(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 = IsBooting();
+        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);
+}
+
+void HandleFirmwareEvent(const 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;
+        ProcessFirmwareEvent(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;
+    }
+}