Improve TrafficStats UID APIs.

Deprecate transport layer statistics, leaving only the summarized
network layer statistics.

Improve documentation to be clear about layers where measurements
occur, and their behavior since boot.  Under the hood, move to using
xt_qtaguid UID statistics.

Bug: 6818637, 7013662
Change-Id: I9f26992e5fcdebd88c671e5765bd91229e7b0016

core/java/android/net/TrafficStats.java

@@ -424,161 +424,156 @@ public class TrafficStats {
     }
 
     /**
-     * Get the number of bytes sent through the network for this UID.
+     * Return number of bytes transmitted by the given UID since device boot.
-     * The statistics are across all interfaces.
+     * Counts packets across all network interfaces, and always increases
+     * monotonically since device boot. Statistics are measured at the network
+     * layer, so they include both TCP and UDP usage.
+     * <p>
+     * Before {@link android.os.Build.VERSION_CODES#K}, this may return
+     * {@link #UNSUPPORTED} on devices where statistics aren't available.
      *
-     * {@see android.os.Process#myUid()}.
+     * @see android.os.Process#myUid()
-     *
+     * @see android.content.pm.ApplicationInfo#uid
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidTxBytes(int uid);
+    public static long getUidTxBytes(int uid) {
+        return nativeGetUidStat(uid, TYPE_TX_BYTES);
+    }
 
     /**
-     * Get the number of bytes received through the network for this UID.
+     * Return number of bytes received by the given UID since device boot.
-     * The statistics are across all interfaces.
+     * Counts packets across all network interfaces, and always increases
+     * monotonically since device boot. Statistics are measured at the network
+     * layer, so they include both TCP and UDP usage.
+     * <p>
+     * Before {@link android.os.Build.VERSION_CODES#K}, this may return
+     * {@link #UNSUPPORTED} on devices where statistics aren't available.
      *
-     * {@see android.os.Process#myUid()}.
+     * @see android.os.Process#myUid()
-     *
+     * @see android.content.pm.ApplicationInfo#uid
-     * @param uid The UID of the process to examine.
-     * @return number of bytes
      */
-    public static native long getUidRxBytes(int uid);
+    public static long getUidRxBytes(int uid) {
+        return nativeGetUidStat(uid, TYPE_RX_BYTES);
+    }
 
     /**
-     * Get the number of packets (TCP segments + UDP) sent through
+     * Return number of packets transmitted by the given UID since device boot.
-     * the network for this UID.
+     * Counts packets across all network interfaces, and always increases
-     * The statistics are across all interfaces.
+     * monotonically since device boot. Statistics are measured at the network
+     * layer, so they include both TCP and UDP usage.
+     * <p>
+     * Before {@link android.os.Build.VERSION_CODES#K}, this may return
+     * {@link #UNSUPPORTED} on devices where statistics aren't available.
      *
-     * {@see android.os.Process#myUid()}.
+     * @see android.os.Process#myUid()
-     *
+     * @see android.content.pm.ApplicationInfo#uid
-     * @param uid The UID of the process to examine.
-     * @return number of packets.
-     * If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidTxPackets(int uid);
+    public static long getUidTxPackets(int uid) {
+        return nativeGetUidStat(uid, TYPE_TX_PACKETS);
+    }
 
     /**
-     * Get the number of packets (TCP segments + UDP) received through
+     * Return number of packets received by the given UID since device boot.
-     * the network for this UID.
+     * Counts packets across all network interfaces, and always increases
-     * The statistics are across all interfaces.
+     * monotonically since device boot. Statistics are measured at the network
+     * layer, so they include both TCP and UDP usage.
+     * <p>
+     * Before {@link android.os.Build.VERSION_CODES#K}, this may return
+     * {@link #UNSUPPORTED} on devices where statistics aren't available.
      *
-     * {@see android.os.Process#myUid()}.
+     * @see android.os.Process#myUid()
-     *
+     * @see android.content.pm.ApplicationInfo#uid
-     * @param uid The UID of the process to examine.
-     * @return number of packets
      */
-    public static native long getUidRxPackets(int uid);
+    public static long getUidRxPackets(int uid) {
+        return nativeGetUidStat(uid, TYPE_RX_PACKETS);
+    }
 
     /**
-     * Get the number of TCP payload bytes sent for this UID.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
-     * This total does not include protocol and control overheads at
+     *             transport layer statistics are no longer available, and will
-     * the transport and the lower layers of the networking stack.
+     *             always return {@link #UNSUPPORTED}.
-     * The statistics are across all interfaces.
+     * @see #getUidTxBytes(int)
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidTcpTxBytes(int uid);
+    @Deprecated
+    public static long getUidTcpTxBytes(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of TCP payload bytes received for this UID.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
-     * This total does not include protocol and control overheads at
+     *             transport layer statistics are no longer available, and will
-     * the transport and the lower layers of the networking stack.
+     *             always return {@link #UNSUPPORTED}.
-     * The statistics are across all interfaces.
+     * @see #getUidRxBytes(int)
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidTcpRxBytes(int uid);
+    @Deprecated
+    public static long getUidTcpRxBytes(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of UDP payload bytes sent for this UID.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
-     * This total does not include protocol and control overheads at
+     *             transport layer statistics are no longer available, and will
-     * the transport and the lower layers of the networking stack.
+     *             always return {@link #UNSUPPORTED}.
-     * The statistics are across all interfaces.
+     * @see #getUidTxBytes(int)
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidUdpTxBytes(int uid);
+    @Deprecated
+    public static long getUidUdpTxBytes(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of UDP payload bytes received for this UID.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
-     * This total does not include protocol and control overheads at
+     *             transport layer statistics are no longer available, and will
-     * the transport and the lower layers of the networking stack.
+     *             always return {@link #UNSUPPORTED}.
-     * The statistics are across all interfaces.
+     * @see #getUidRxBytes(int)
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidUdpRxBytes(int uid);
+    @Deprecated
+    public static long getUidUdpRxBytes(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of TCP segments sent for this UID.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
-     * Does not include TCP control packets (SYN/ACKs/FIN/..).
+     *             transport layer statistics are no longer available, and will
-     * The statistics are across all interfaces.
+     *             always return {@link #UNSUPPORTED}.
-     *
+     * @see #getUidTxPackets(int)
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of TCP segments.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidTcpTxSegments(int uid);
+    @Deprecated
+    public static long getUidTcpTxSegments(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of TCP segments received for this UID.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
-     * Does not include TCP control packets (SYN/ACKs/FIN/..).
+     *             transport layer statistics are no longer available, and will
-     * The statistics are across all interfaces.
+     *             always return {@link #UNSUPPORTED}.
-     *
+     * @see #getUidRxPackets(int)
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of TCP segments.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidTcpRxSegments(int uid);
+    @Deprecated
+    public static long getUidTcpRxSegments(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of UDP packets sent for this UID.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
-     * Includes DNS requests.
+     *             transport layer statistics are no longer available, and will
-     * The statistics are across all interfaces.
+     *             always return {@link #UNSUPPORTED}.
-     *
+     * @see #getUidTxPackets(int)
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of packets.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidUdpTxPackets(int uid);
+    @Deprecated
+    public static long getUidUdpTxPackets(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of UDP packets received for this UID.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
-     * Includes DNS responses.
+     *             transport layer statistics are no longer available, and will
-     * The statistics are across all interfaces.
+     *             always return {@link #UNSUPPORTED}.
-     *
+     * @see #getUidRxPackets(int)
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of packets.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
      */
-    public static native long getUidUdpRxPackets(int uid);
+    @Deprecated
+    public static long getUidUdpRxPackets(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
      * Return detailed {@link NetworkStats} for the current UID. Requires no
@@ -616,4 +611,5 @@ public class TrafficStats {
 
     private static native long nativeGetTotalStat(int type);
     private static native long nativeGetIfaceStat(String iface, int type);
+    private static native long nativeGetUidStat(int uid, int type);
 }

core/jni/android_net_TrafficStats.cpp

@@ -32,17 +32,7 @@
 namespace android {
 
 static const char* QTAGUID_IFACE_STATS = "/proc/net/xt_qtaguid/iface_stat_fmt";
-
+static const char* QTAGUID_UID_STATS = "/proc/net/xt_qtaguid/stats";
-enum Tx_Rx {
-    TX,
-    RX
-};
-
-enum Tcp_Udp {
-    TCP,
-    UDP,
-    TCP_AND_UDP
-};
 
 // NOTE: keep these in sync with TrafficStats.java
 static const uint64_t UNKNOWN = -1;
@@ -84,27 +74,6 @@ static uint64_t getStatsType(struct Stats* stats, StatsType type) {
     }
 }
 
-// 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) ALOGE("Can't open %s: %s", filename, strerror(errno));
-        return -1;
-    }
-
-    int len = read(fd, buf, sizeof(buf) - 1);
-    if (len < 0) {
-        ALOGE("Can't read %s: %s", filename, strerror(errno));
-        close(fd);
-        return -1;
-    }
-
-    close(fd);
-    buf[len] = '\0';
-    return atoll(buf);
-}
-
 static int parseIfaceStats(const char* iface, struct Stats* stats) {
     FILE *fp = fopen(QTAGUID_IFACE_STATS, "r");
     if (fp == NULL) {
@@ -149,6 +118,36 @@ static int parseIfaceStats(const char* iface, struct Stats* stats) {
     return 0;
 }
 
+static int parseUidStats(const uint32_t uid, struct Stats* stats) {
+    FILE *fp = fopen(QTAGUID_UID_STATS, "r");
+    if (fp == NULL) {
+        return -1;
+    }
+
+    char buffer[256];
+    char iface[32];
+    uint32_t idx, cur_uid, set;
+    uint64_t tag, rxBytes, rxPackets, txBytes, txPackets;
+
+    while (fgets(buffer, 256, fp) != NULL) {
+        if (sscanf(buffer, "%d %31s 0x%llx %u %u %llu %llu %llu %llu", &idx,
+                iface, &tag, &cur_uid, &set, &rxBytes, &rxPackets, &txBytes,
+                &txPackets) == 9) {
+            if (uid == cur_uid && tag == 0L) {
+                stats->rxBytes += rxBytes;
+                stats->rxPackets += rxPackets;
+                stats->txBytes += txBytes;
+                stats->txPackets += txPackets;
+            }
+        }
+    }
+
+    if (fclose(fp) != 0) {
+        return -1;
+    }
+    return 0;
+}
+
 static jlong getTotalStat(JNIEnv* env, jclass clazz, jint type) {
     struct Stats stats;
     memset(&stats, 0, sizeof(Stats));
@@ -174,160 +173,20 @@ static jlong getIfaceStat(JNIEnv* env, jclass clazz, jstring iface, jint type) {
     }
 }
 
-
+static jlong getUidStat(JNIEnv* env, jclass clazz, jint uid, jint type) {
-// Per-UID stats require reading from a constructed filename.
+    struct Stats stats;
-
+    memset(&stats, 0, sizeof(Stats));
-static jlong getUidBytes(JNIEnv* env, jobject clazz, jint uid,
+    if (parseUidStats(uid, &stats) == 0) {
-                         enum Tx_Rx tx_or_rx, enum Tcp_Udp tcp_or_udp) {
+        return getStatsType(&stats, (StatsType) type);
-    char tcp_filename[80], udp_filename[80];
+    } else {
-    jlong tcp_bytes = -1, udp_bytes = -1, total_bytes = -1;
+        return UNKNOWN;
-
-    switch (tx_or_rx) {
-        case TX:
-            sprintf(tcp_filename, "/proc/uid_stat/%d/tcp_snd", uid);
-            sprintf(udp_filename, "/proc/uid_stat/%d/udp_snd", uid);
-            break;
-        case RX:
-            sprintf(tcp_filename, "/proc/uid_stat/%d/tcp_rcv", uid);
-            sprintf(udp_filename, "/proc/uid_stat/%d/udp_rcv", uid);
-            break;
-        default:
-            return -1;
     }
-
-    switch (tcp_or_udp) {
-        case TCP:
-            tcp_bytes = readNumber(tcp_filename);
-            total_bytes = (tcp_bytes >= 0) ? tcp_bytes : -1;
-            break;
-        case UDP:
-            udp_bytes = readNumber(udp_filename);
-            total_bytes = (udp_bytes >= 0) ? udp_bytes : -1;
-            break;
-        case TCP_AND_UDP:
-            tcp_bytes = readNumber(tcp_filename);
-            total_bytes += (tcp_bytes >= 0 ? tcp_bytes : 0);
-
-            udp_bytes = readNumber(udp_filename);
-            total_bytes += (udp_bytes >= 0 ? udp_bytes : 0);
-            break;
-        default:
-            return -1;
-    }
-
-    return total_bytes;
-}
-
-static jlong getUidPkts(JNIEnv* env, jobject clazz, jint uid,
-                         enum Tx_Rx tx_or_rx, enum Tcp_Udp tcp_or_udp) {
-    char tcp_filename[80], udp_filename[80];
-    jlong tcp_pkts = -1, udp_pkts = -1, total_pkts = -1;
-
-    switch (tx_or_rx) {
-        case TX:
-            sprintf(tcp_filename, "/proc/uid_stat/%d/tcp_snd_pkt", uid);
-            sprintf(udp_filename, "/proc/uid_stat/%d/udp_snd_pkt", uid);
-            break;
-        case RX:
-            sprintf(tcp_filename, "/proc/uid_stat/%d/tcp_rcv_pkt", uid);
-            sprintf(udp_filename, "/proc/uid_stat/%d/udp_rcv_pkt", uid);
-            break;
-        default:
-            return -1;
-    }
-
-    switch (tcp_or_udp) {
-        case TCP:
-            tcp_pkts = readNumber(tcp_filename);
-            total_pkts = (tcp_pkts >= 0) ? tcp_pkts : -1;
-            break;
-        case UDP:
-            udp_pkts = readNumber(udp_filename);
-            total_pkts = (udp_pkts >= 0) ? udp_pkts : -1;
-            break;
-        case TCP_AND_UDP:
-            tcp_pkts = readNumber(tcp_filename);
-            total_pkts += (tcp_pkts >= 0 ? tcp_pkts : 0);
-
-            udp_pkts = readNumber(udp_filename);
-            total_pkts += (udp_pkts >= 0 ? udp_pkts : 0);
-            break;
-        default:
-            return -1;
-    }
-
-    return total_pkts;
-}
-
-static jlong getUidRxBytes(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidBytes(env, clazz, uid, RX, TCP_AND_UDP);
-}
-
-static jlong getUidTxBytes(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidBytes(env, clazz, uid, TX, TCP_AND_UDP);
-}
-
-/* TCP Segments + UDP Packets */
-static jlong getUidTxPackets(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidPkts(env, clazz, uid, TX, TCP_AND_UDP);
-}
-
-/* TCP Segments + UDP Packets */
-static jlong getUidRxPackets(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidPkts(env, clazz, uid, RX, TCP_AND_UDP);
-}
-
-static jlong getUidTcpTxBytes(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidBytes(env, clazz, uid, TX, TCP);
-}
-
-static jlong getUidTcpRxBytes(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidBytes(env, clazz, uid, RX, TCP);
-}
-
-static jlong getUidUdpTxBytes(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidBytes(env, clazz, uid, TX, UDP);
-}
-
-static jlong getUidUdpRxBytes(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidBytes(env, clazz, uid, RX, UDP);
-}
-
-static jlong getUidTcpTxSegments(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidPkts(env, clazz, uid, TX, TCP);
-}
-
-static jlong getUidTcpRxSegments(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidPkts(env, clazz, uid, RX, TCP);
-}
-
-static jlong getUidUdpTxPackets(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidPkts(env, clazz, uid, TX, UDP);
-}
-
-static jlong getUidUdpRxPackets(JNIEnv* env, jobject clazz, jint uid) {
-    return getUidPkts(env, clazz, uid, RX, UDP);
 }
 
 static JNINativeMethod gMethods[] = {
     {"nativeGetTotalStat", "(I)J", (void*) getTotalStat},
     {"nativeGetIfaceStat", "(Ljava/lang/String;I)J", (void*) getIfaceStat},
-
+    {"nativeGetUidStat", "(II)J", (void*) getUidStat},
-    /* Per-UID Stats */
-    {"getUidTxBytes", "(I)J", (void*) getUidTxBytes},
-    {"getUidRxBytes", "(I)J", (void*) getUidRxBytes},
-    {"getUidTxPackets", "(I)J", (void*) getUidTxPackets},
-    {"getUidRxPackets", "(I)J", (void*) getUidRxPackets},
-
-    {"getUidTcpTxBytes", "(I)J", (void*) getUidTcpTxBytes},
-    {"getUidTcpRxBytes", "(I)J", (void*) getUidTcpRxBytes},
-    {"getUidUdpTxBytes", "(I)J", (void*) getUidUdpTxBytes},
-    {"getUidUdpRxBytes", "(I)J", (void*) getUidUdpRxBytes},
-
-    {"getUidTcpTxSegments", "(I)J", (void*) getUidTcpTxSegments},
-    {"getUidTcpRxSegments", "(I)J", (void*) getUidTcpRxSegments},
-    {"getUidUdpTxPackets", "(I)J", (void*) getUidUdpTxPackets},
-    {"getUidUdpRxPackets", "(I)J", (void*) getUidUdpRxPackets},
 };
 
 int register_android_net_TrafficStats(JNIEnv* env) {