wifiloader: Load kernel module if present

Samsung does this in the macloader service,
but this is the more appropriate place for
our platform.

Change-Id: I6335fea1d73d48f3c3f9938f33b536c5cda52acb

wifiloader/Android.mk

@@ -9,6 +9,14 @@ LOCAL_SRC_FILES := \
 LOCAL_SHARED_LIBRARIES := \
     liblog libutils
 
+ifneq ($(WIFI_DRIVER_MODULE_NAME),)
+LOCAL_CFLAGS += -DWIFI_DRIVER_MODULE_NAME=\"$(WIFI_DRIVER_MODULE_NAME)\"
+endif
+
+ifneq ($(WIFI_DRIVER_MODULE_PATH),)
+LOCAL_CFLAGS += -DWIFI_DRIVER_MODULE_PATH=\"$(WIFI_DRIVER_MODULE_PATH)\"
+endif
+
 LOCAL_MODULE := wifiloader
 LOCAL_MODULE_TAGS := optional
 

wifiloader/wifiloader.c

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2015      Andreas Schneider <asn@cryptomilk.org>
+ * Copyright (c) 2017      Christopher N. Hesse <raymanfx@gmail.com>
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,17 +19,86 @@
 #define LOG_NDEBUG 0
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <cutils/log.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
 
-#define DEFERRED_INITCALLS "/proc/deferred_initcalls"
+#define DEFERRED_INITCALLS        "/proc/deferred_initcalls"
+
+#ifndef WIFI_DRIVER_MODULE_NAME
+#define WIFI_DRIVER_MODULE_NAME   "wlan"
+#endif
+
+#ifndef WIFI_DRIVER_MODULE_PATH
+#define WIFI_DRIVER_MODULE_PATH   "/system/lib/modules/" WIFI_DRIVER_MODULE_NAME ".ko"
+#endif
+
+#define finit_module(fd, params, flags) syscall(__NR_finit_module, fd, params, flags)
+
+
+static int check_module_loaded(char const *tag)
+{
+    FILE *proc;
+    char line[126];
+
+    if ((proc = fopen("/proc/modules", "r")) == NULL) {
+        ALOGW("Could not open %s: %s", "/proc/modules", strerror(errno));
+        return -errno;
+    }
+
+    while ((fgets(line, sizeof(line), proc)) != NULL) {
+        if (strncmp(line, tag, strlen(tag)) == 0) {
+            fclose(proc);
+            return 1;
+        }
+    }
+
+    fclose(proc);
+    return 0;
+}
+
+static int load_module(char const *path)
+{
+    int fd;
+
+    if (check_module_loaded(WIFI_DRIVER_MODULE_NAME) > 0) {
+        ALOGE("Driver: %s already loaded", path);
+        return -1;
+    }
+
+    fd = open(path, O_RDONLY);
+    if (fd == -1) {
+        ALOGE("Failed to open %s - error: %s", path, strerror(errno));
+        return -errno;
+    }
+
+    // load the .ko image
+    if (finit_module(fd, "", 0) != 0) {
+        ALOGE("Failed to load module %s - error: %s", path, strerror(errno));
+        close(fd);
+        return -errno;
+    }
+
+    close(fd);
+    return 0;
+}
 
 int main(void)
 {
     char buf[8] = { '\0' };
     FILE *fp;
     size_t r;
+    int fd;
+    struct stat st;
+
+    if (stat(WIFI_DRIVER_MODULE_PATH, &st) == 0) {
+        ALOGD("Loading WiFi kernel module: %s", WIFI_DRIVER_MODULE_PATH);
+        load_module(WIFI_DRIVER_MODULE_PATH);
+    }
 
     ALOGD("Trigger initcall of deferred modules\n");