Change TrafficStats to a new JNI implementation.

Also change phone's ConnectionStateTrackers to use it directly,
rather than through the INetStat binder interface.

Bug: 2578938
Change-Id: I8858e2609cbec3be845a0ce5178cb03f67e01b41

1 files changed, 165 insertions, 0 deletions

diff --git a/core/jni/android_net_TrafficStats.cpp b/core/jni/android_net_TrafficStats.cpp
new file mode 100644
index 0000000..db8fdf2
--- /dev/null
+++ b/core/jni/android_net_TrafficStats.cpp
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#define LOG_TAG "TrafficStats"
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <android_runtime/AndroidRuntime.h>
+#include <cutils/logger.h>
+#include <jni.h>
+#include <utils/misc.h>
+#include <utils/Log.h>
+
+namespace android {
+
+// Returns an ASCII decimal number read from the specified file, -1 on error.
+static jlong readNumber(char const* filename) {
+    char buf[80];
+    int fd = open(filename, O_RDONLY);
+    if (fd < 0) {
+        if (errno != ENOENT) LOGE("Can't open %s: %s", filename, strerror(errno));
+        return -1;
+    }
+
+    int len = read(fd, buf, sizeof(buf) - 1);
+    if (len < 0) {
+        LOGE("Can't read %s: %s", filename, strerror(errno));
+        close(fd);
+        return -1;
+    }
+
+    close(fd);
+    buf[len] = '\0';
+    return atoll(buf);
+}
+
+// Return the number from the first file which exists and contains data
+static jlong tryBoth(char const* a, char const* b) {
+    jlong num = readNumber(a);
+    return num >= 0 ? num : readNumber(b);
+}
+
+// Returns the sum of numbers from the specified path under /sys/class/net/*,
+// -1 if no such file exists.
+static jlong readTotal(char const* suffix) {
+    char filename[PATH_MAX] = "/sys/class/net/";
+    DIR *dir = opendir(filename);
+    if (dir == NULL) {
+        LOGE("Can't list %s: %s", filename, strerror(errno));
+        return -1;
+    }
+
+    int len = strlen(filename);
+    jlong total = -1;
+    while (struct dirent *entry = readdir(dir)) {
+        // Skip ., .., and localhost interfaces.
+        if (entry->d_name[0] != '.' && strncmp(entry->d_name, "lo", 2) != 0) {
+            strlcpy(filename + len, entry->d_name, sizeof(filename) - len);
+            strlcat(filename, suffix, sizeof(filename));
+            jlong num = readNumber(filename);
+            if (num >= 0) total = total < 0 ? num : total + num;
+        }
+    }
+
+    closedir(dir);
+    return total;
+}
+
+// Mobile stats get accessed a lot more often than total stats.
+// Note the individual files can come and go at runtime, so we check
+// each file every time (rather than caching which ones exist).
+
+static jlong getMobileTxPackets(JNIEnv* env, jobject clazz) {
+    return tryBoth(
+            "/sys/class/net/rmnet0/statistics/tx_packets",
+            "/sys/class/net/ppp0/statistics/tx_packets");
+}
+
+static jlong getMobileRxPackets(JNIEnv* env, jobject clazz) {
+    return tryBoth(
+            "/sys/class/net/rmnet0/statistics/rx_packets",
+            "/sys/class/net/ppp0/statistics/rx_packets");
+}
+
+static jlong getMobileTxBytes(JNIEnv* env, jobject clazz) {
+    return tryBoth(
+            "/sys/class/net/rmnet0/statistics/tx_bytes",
+            "/sys/class/net/ppp0/statistics/tx_bytes");
+}
+
+static jlong getMobileRxBytes(JNIEnv* env, jobject clazz) {
+    return tryBoth(
+            "/sys/class/net/rmnet0/statistics/rx_bytes",
+            "/sys/class/net/ppp0/statistics/rx_bytes");
+}
+
+// Total stats are read less often, so we're willing to put up
+// with listing the directory and concatenating filenames.
+
+static jlong getTotalTxPackets(JNIEnv* env, jobject clazz) {
+    return readTotal("/statistics/tx_packets");
+}
+
+static jlong getTotalRxPackets(JNIEnv* env, jobject clazz) {
+    return readTotal("/statistics/rx_packets");
+}
+
+static jlong getTotalTxBytes(JNIEnv* env, jobject clazz) {
+    return readTotal("/statistics/tx_bytes");
+}
+
+static jlong getTotalRxBytes(JNIEnv* env, jobject clazz) {
+    return readTotal("/statistics/rx_bytes");
+}
+
+// Per-UID stats require reading from a constructed filename.
+
+static jlong getUidRxBytes(JNIEnv* env, jobject clazz, jint uid) {
+    char filename[80];
+    sprintf(filename, "/proc/uid_stat/%d/tcp_rcv", uid);
+    return readNumber(filename);
+}
+
+static jlong getUidTxBytes(JNIEnv* env, jobject clazz, jint uid) {
+    char filename[80];
+    sprintf(filename, "/proc/uid_stat/%d/tcp_snd", uid);
+    return readNumber(filename);
+}
+
+static JNINativeMethod gMethods[] = {
+    {"getMobileTxPackets", "()J", (void*) getMobileTxPackets},
+    {"getMobileRxPackets", "()J", (void*) getMobileRxPackets},
+    {"getMobileTxBytes", "()J", (void*) getMobileTxBytes},
+    {"getMobileRxBytes", "()J", (void*) getMobileRxBytes},
+    {"getTotalTxPackets", "()J", (void*) getTotalTxPackets},
+    {"getTotalRxPackets", "()J", (void*) getTotalRxPackets},
+    {"getTotalTxBytes", "()J", (void*) getTotalTxBytes},
+    {"getTotalRxBytes", "()J", (void*) getTotalRxBytes},
+    {"getUidTxBytes", "(I)J", (void*) getUidTxBytes},
+    {"getUidRxBytes", "(I)J", (void*) getUidRxBytes},
+};
+
+int register_android_net_TrafficStats(JNIEnv* env) {
+    return AndroidRuntime::registerNativeMethods(env, "android/net/TrafficStats",
+            gMethods, NELEM(gMethods));
+}
+
+}