Add IPv6 Handling for DSCP Policies and Support Interfaces with MAC Addresses

Add bpf functionality to handle IPv6 packets and apply
DSCP value.
Also support DSCP policy rules on multiple interfaces
simultaneously.

Test: atest DscpPolicyTest

Bug: 217166486
Change-Id: I452a87355fd0382a4c38b84aa3465505951d9bf0
diff --git a/bpf_progs/dscp_policy.c b/bpf_progs/dscp_policy.c
index 9989e6b..d5df7ef 100644
--- a/bpf_progs/dscp_policy.c
+++ b/bpf_progs/dscp_policy.c
@@ -16,6 +16,7 @@
 
 #include <linux/types.h>
 #include <linux/bpf.h>
+#include <linux/if_packet.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/if_ether.h>
@@ -27,249 +28,294 @@
 #include <string.h>
 
 #include "bpf_helpers.h"
+#include "dscp_policy.h"
 
-#define MAX_POLICIES 16
-#define MAP_A 1
-#define MAP_B 2
-
-#define STRUCT_SIZE(name, size) _Static_assert(sizeof(name) == (size), "Incorrect struct size.")
-
-// TODO: these are already defined in /system/netd/bpf_progs/bpf_net_helpers.h
-// should they be moved to common location?
-static uint64_t (*bpf_get_socket_cookie)(struct __sk_buff* skb) =
-        (void*)BPF_FUNC_get_socket_cookie;
-static int (*bpf_skb_store_bytes)(struct __sk_buff* skb, __u32 offset, const void* from, __u32 len,
-                                  __u64 flags) = (void*)BPF_FUNC_skb_store_bytes;
-static int (*bpf_l3_csum_replace)(struct __sk_buff* skb, __u32 offset, __u64 from, __u64 to,
-                                  __u64 flags) = (void*)BPF_FUNC_l3_csum_replace;
-
-typedef struct {
-    // Add family here to match __sk_buff ?
-    struct in_addr srcIp;
-    struct in_addr dstIp;
-    __be16 srcPort;
-    __be16 dstPort;
-    uint8_t proto;
-    uint8_t dscpVal;
-    uint8_t pad[2];
-} Ipv4RuleEntry;
-STRUCT_SIZE(Ipv4RuleEntry, 2 * 4 + 2 * 2 + 2 * 1 + 2);  // 16, 4 for in_addr
-
-#define SRC_IP_MASK     1
-#define DST_IP_MASK     2
-#define SRC_PORT_MASK   4
-#define DST_PORT_MASK   8
-#define PROTO_MASK      16
-
-typedef struct {
-    struct in6_addr srcIp;
-    struct in6_addr dstIp;
-    __be16 srcPort;
-    __be16 dstPortStart;
-    __be16 dstPortEnd;
-    uint8_t proto;
-    uint8_t dscpVal;
-    uint8_t mask;
-    uint8_t pad[3];
-} Ipv4Policy;
-STRUCT_SIZE(Ipv4Policy, 2 * 16 + 3 * 2 + 3 * 1 + 3);  // 44
-
-typedef struct {
-    struct in6_addr srcIp;
-    struct in6_addr dstIp;
-    __be16 srcPort;
-    __be16 dstPortStart;
-    __be16 dstPortEnd;
-    uint8_t proto;
-    uint8_t dscpVal;
-    uint8_t mask;
-    // should we override this struct to include the param bitmask for linear search?
-    // For mapping socket to policies, all the params should match exactly since we can
-    // pull any missing from the sock itself.
-} Ipv6RuleEntry;
-STRUCT_SIZE(Ipv6RuleEntry, 2 * 16 + 3 * 2 + 3 * 1 + 3);  // 44
-
-// TODO: move to using 1 map. Map v4 address to 0xffff::v4
-DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map_A, HASH, uint64_t, Ipv4RuleEntry, MAX_POLICIES,
-        AID_SYSTEM)
-DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map_B, HASH, uint64_t, Ipv4RuleEntry, MAX_POLICIES,
-        AID_SYSTEM)
-DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map_A, HASH, uint64_t, Ipv6RuleEntry, MAX_POLICIES,
-        AID_SYSTEM)
-DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map_B, HASH, uint64_t, Ipv6RuleEntry, MAX_POLICIES,
-        AID_SYSTEM)
 DEFINE_BPF_MAP_GRW(switch_comp_map, ARRAY, int, uint64_t, 1, AID_SYSTEM)
 
-DEFINE_BPF_MAP_GRW(ipv4_dscp_policies_map, ARRAY, uint32_t, Ipv4Policy, MAX_POLICIES,
+DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map_A, HASH, uint64_t, RuleEntry, MAX_POLICIES,
         AID_SYSTEM)
-DEFINE_BPF_MAP_GRW(ipv6_dscp_policies_map, ARRAY, uint32_t, Ipv6RuleEntry, MAX_POLICIES,
+DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map_B, HASH, uint64_t, RuleEntry, MAX_POLICIES,
+        AID_SYSTEM)
+DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map_A, HASH, uint64_t, RuleEntry, MAX_POLICIES,
+        AID_SYSTEM)
+DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map_B, HASH, uint64_t, RuleEntry, MAX_POLICIES,
         AID_SYSTEM)
 
-DEFINE_BPF_PROG_KVER("schedcls/set_dscp", AID_ROOT, AID_SYSTEM,
-                     schedcls_set_dscp, KVER(5, 4, 0))
-(struct __sk_buff* skb) {
-    int one = 0;
-    uint64_t* selectedMap = bpf_switch_comp_map_lookup_elem(&one);
+DEFINE_BPF_MAP_GRW(ipv4_dscp_policies_map, ARRAY, uint32_t, DscpPolicy, MAX_POLICIES,
+        AID_SYSTEM)
+DEFINE_BPF_MAP_GRW(ipv6_dscp_policies_map, ARRAY, uint32_t, DscpPolicy, MAX_POLICIES,
+        AID_SYSTEM)
+
+static inline __always_inline void match_policy(struct __sk_buff* skb, bool ipv4, bool is_eth) {
+    void* data = (void*)(long)skb->data;
+    const void* data_end = (void*)(long)skb->data_end;
+
+    const int l2_header_size = is_eth ? sizeof(struct ethhdr) : 0;
+    struct ethhdr* eth = is_eth ? data : NULL;
+
+    if (data + l2_header_size > data_end) return;
+
+    int zero = 0;
+    int hdr_size = 0;
+    uint64_t* selectedMap = bpf_switch_comp_map_lookup_elem(&zero);
 
     // use this with HASH map so map lookup only happens once policies have been added?
     if (!selectedMap) {
-        return TC_ACT_PIPE;
+        return;
     }
 
     // used for map lookup
     uint64_t cookie = bpf_get_socket_cookie(skb);
+    if (!cookie)
+        return;
 
-    // Do we need separate maps for ipv4/ipv6
-    if (skb->protocol == htons(ETH_P_IP)) { //maybe bpf_htons()
-        Ipv4RuleEntry* v4Policy;
-        if (*selectedMap == MAP_A) {
-            v4Policy = bpf_ipv4_socket_to_policies_map_A_lookup_elem(&cookie);
-        } else {
-            v4Policy = bpf_ipv4_socket_to_policies_map_B_lookup_elem(&cookie);
-        }
-
-        // How to use bitmask here to compare params efficiently?
-        // TODO: add BPF_PROG_TYPE_SK_SKB prog type to Loader?
-
-        void* data = (void*)(long)skb->data;
-        const void* data_end = (void*)(long)skb->data_end;
-        const struct iphdr* const iph = data;
-
+    uint16_t sport = 0;
+    uint16_t dport = 0;
+    uint8_t protocol = 0; // TODO: Use are reserved value? Or int (-1) and cast to uint below?
+    struct in6_addr srcIp = {};
+    struct in6_addr dstIp = {};
+    uint8_t tos = 0; // Only used for IPv4
+    uint8_t priority = 0; // Only used for IPv6
+    uint8_t flow_lbl = 0; // Only used for IPv6
+    if (ipv4) {
+        const struct iphdr* const iph = is_eth ? (void*)(eth + 1) : data;
         // Must have ipv4 header
-        if (data + sizeof(*iph) > data_end) return TC_ACT_PIPE;
+        if (data + l2_header_size + sizeof(*iph) > data_end) return;
 
         // IP version must be 4
-        if (iph->version != 4) return TC_ACT_PIPE;
+        if (iph->version != 4) return;
 
         // We cannot handle IP options, just standard 20 byte == 5 dword minimal IPv4 header
-        if (iph->ihl != 5) return TC_ACT_PIPE;
+        if (iph->ihl != 5) return;
 
-        if (iph->protocol != IPPROTO_UDP) return TC_ACT_PIPE;
+        // V4 mapped address in in6_addr sets 10/11 position to 0xff.
+        srcIp.s6_addr32[2] = htonl(0x0000ffff);
+        dstIp.s6_addr32[2] = htonl(0x0000ffff);
 
-        struct udphdr *udp;
-        udp = data + sizeof(struct iphdr); //sizeof(struct ethhdr)
+        // Copy IPv4 address into in6_addr for easy comparison below.
+        srcIp.s6_addr32[3] = iph->saddr;
+        dstIp.s6_addr32[3] = iph->daddr;
+        protocol = iph->protocol;
+        tos = iph->tos;
+        hdr_size = sizeof(struct iphdr);
+    } else {
+        struct ipv6hdr* ip6h = is_eth ? (void*)(eth + 1) : data;
+        // Must have ipv6 header
+        if (data + l2_header_size + sizeof(*ip6h) > data_end) return;
 
-        if ((void*)(udp + 1) > data_end) return TC_ACT_PIPE;
+        if (ip6h->version != 6) return;
 
-        // Source/destination port in udphdr are stored in be16, need to convert to le16.
-        // This can be done via ntohs or htons. Is there a more preferred way?
-        // Cached policy was found.
-        if (v4Policy && iph->saddr == v4Policy->srcIp.s_addr &&
-                    iph->daddr == v4Policy->dstIp.s_addr &&
-                    ntohs(udp->source) == v4Policy->srcPort &&
-                    ntohs(udp->dest) == v4Policy->dstPort &&
-                    iph->protocol == v4Policy->proto) {
-            // set dscpVal in packet. Least sig 2 bits of TOS
-            // reference ipv4_change_dsfield()
+        srcIp = ip6h->saddr;
+        dstIp = ip6h->daddr;
+        protocol = ip6h->nexthdr;
+        priority = ip6h->priority;
+        flow_lbl = ip6h->flow_lbl[0];
+        hdr_size = sizeof(struct ipv6hdr);
+    }
 
-            // TODO: fix checksum...
-            int ecn = iph->tos & 3;
-            uint8_t newDscpVal = (v4Policy->dscpVal << 2) + ecn;
-            int oldDscpVal = iph->tos >> 2;
+    switch (protocol) {
+        case IPPROTO_UDP:
+        case IPPROTO_UDPLITE:
+        {
+            struct udphdr *udp;
+            udp = data + hdr_size;
+            if ((void*)(udp + 1) > data_end) return;
+            sport = udp->source;
+            dport = udp->dest;
+        }
+        break;
+        case IPPROTO_TCP:
+        {
+            struct tcphdr *tcp;
+            tcp = data + hdr_size;
+            if ((void*)(tcp + 1) > data_end) return;
+            sport = tcp->source;
+            dport = tcp->dest;
+        }
+        break;
+        default:
+            return;
+    }
+
+    RuleEntry* existingRule;
+    if (ipv4) {
+        if (*selectedMap == MAP_A) {
+            existingRule = bpf_ipv4_socket_to_policies_map_A_lookup_elem(&cookie);
+        } else {
+            existingRule = bpf_ipv4_socket_to_policies_map_B_lookup_elem(&cookie);
+        }
+    } else {
+        if (*selectedMap == MAP_A) {
+            existingRule = bpf_ipv6_socket_to_policies_map_A_lookup_elem(&cookie);
+        } else {
+            existingRule = bpf_ipv6_socket_to_policies_map_B_lookup_elem(&cookie);
+        }
+    }
+
+    if (existingRule && v6_equal(srcIp, existingRule->srcIp) &&
+                v6_equal(dstIp, existingRule->dstIp) &&
+                skb->ifindex == existingRule->ifindex &&
+                ntohs(sport) == htons(existingRule->srcPort) &&
+                ntohs(dport) == htons(existingRule->dstPort) &&
+                protocol == existingRule->proto) {
+        if (ipv4) {
+            int ecn = tos & 3;
+            uint8_t newDscpVal = (existingRule->dscpVal << 2) + ecn;
+            int oldDscpVal = tos >> 2;
             bpf_l3_csum_replace(skb, 1, oldDscpVal, newDscpVal, sizeof(uint8_t));
             bpf_skb_store_bytes(skb, 1, &newDscpVal, sizeof(uint8_t), 0);
-            return TC_ACT_PIPE;
+        } else {
+            uint8_t new_priority = (existingRule->dscpVal >> 2) + 0x60;
+            uint8_t new_flow_label = ((existingRule->dscpVal & 0xf) << 6) + (priority >> 6);
+            bpf_skb_store_bytes(skb, 0, &new_priority, sizeof(uint8_t), 0);
+            bpf_skb_store_bytes(skb, 1, &new_flow_label, sizeof(uint8_t), 0);
+        }
+        return;
+    }
+
+    // Linear scan ipv4_dscp_policies_map since no stored params match skb.
+    int bestScore = -1;
+    uint32_t bestMatch = 0;
+
+    for (register uint64_t i = 0; i < MAX_POLICIES; i++) {
+        int score = 0;
+        uint8_t tempMask = 0;
+        // Using a uint64 in for loop prevents infinite loop during BPF load,
+        // but the key is uint32, so convert back.
+        uint32_t key = i;
+
+        DscpPolicy* policy;
+        if (ipv4) {
+            policy = bpf_ipv4_dscp_policies_map_lookup_elem(&key);
+        } else {
+            policy = bpf_ipv6_dscp_policies_map_lookup_elem(&key);
         }
 
-        // linear scan ipv4_dscp_policies_map, stored socket params do not match actual
-        int bestScore = -1;
-        uint32_t bestMatch = 0;
+        // If the policy lookup failed, presentFields is 0, or iface index does not match
+        // index on skb buff, then we can continue to next policy.
+        if (!policy || policy->presentFields == 0 || policy->ifindex != skb->ifindex)
+            continue;
 
-        for (register uint64_t i = 0; i < MAX_POLICIES; i++) {
-            int score = 0;
-            uint8_t tempMask = 0;
-            // Using a uint62 in for loop prevents infinite loop during BPF load,
-            // but the key is uint32, so convert back.
-            uint32_t key = i;
-            Ipv4Policy* policy = bpf_ipv4_dscp_policies_map_lookup_elem(&key);
+        if ((policy->presentFields & SRC_IP_MASK_FLAG) == SRC_IP_MASK_FLAG &&
+                v6_equal(srcIp, policy->srcIp)) {
+            score++;
+            tempMask |= SRC_IP_MASK_FLAG;
+        }
+        if ((policy->presentFields & DST_IP_MASK_FLAG) == DST_IP_MASK_FLAG &&
+                v6_equal(dstIp, policy->dstIp)) {
+            score++;
+            tempMask |= DST_IP_MASK_FLAG;
+        }
+        if ((policy->presentFields & SRC_PORT_MASK_FLAG) == SRC_PORT_MASK_FLAG &&
+                ntohs(sport) == htons(policy->srcPort)) {
+            score++;
+            tempMask |= SRC_PORT_MASK_FLAG;
+        }
+        if ((policy->presentFields & DST_PORT_MASK_FLAG) == DST_PORT_MASK_FLAG &&
+                ntohs(dport) >= htons(policy->dstPortStart) &&
+                ntohs(dport) <= htons(policy->dstPortEnd)) {
+            score++;
+            tempMask |= DST_PORT_MASK_FLAG;
+        }
+        if ((policy->presentFields & PROTO_MASK_FLAG) == PROTO_MASK_FLAG &&
+                protocol == policy->proto) {
+            score++;
+            tempMask |= PROTO_MASK_FLAG;
+        }
 
-            // if mask is 0 continue, key does not have corresponding policy value
-            if (policy && policy->mask != 0) {
-                if ((policy->mask & SRC_IP_MASK) == SRC_IP_MASK &&
-                        iph->saddr == policy->srcIp.s6_addr32[3]) {
-                    score++;
-                    tempMask |= SRC_IP_MASK;
-                }
-                if ((policy->mask & DST_IP_MASK) == DST_IP_MASK &&
-                        iph->daddr == policy->dstIp.s6_addr32[3]) {
-                    score++;
-                    tempMask |= DST_IP_MASK;
-                }
-                if ((policy->mask & SRC_PORT_MASK) == SRC_PORT_MASK &&
-                        ntohs(udp->source) == htons(policy->srcPort)) {
-                    score++;
-                    tempMask |= SRC_PORT_MASK;
-                }
-                if ((policy->mask & DST_PORT_MASK) == DST_PORT_MASK &&
-                        ntohs(udp->dest) >= htons(policy->dstPortStart) &&
-                        ntohs(udp->dest) <= htons(policy->dstPortEnd)) {
-                    score++;
-                    tempMask |= DST_PORT_MASK;
-                }
-                if ((policy->mask & PROTO_MASK) == PROTO_MASK &&
-                        iph->protocol == policy->proto) {
-                    score++;
-                    tempMask |= PROTO_MASK;
-                }
+        if (score > bestScore && tempMask == policy->presentFields) {
+            bestMatch = i;
+            bestScore = score;
+        }
+    }
 
-                if (score > bestScore && tempMask == policy->mask) {
-                    bestMatch = i;
-                    bestScore = score;
-                }
+    uint8_t new_tos= 0; // Can 0 be used as default forwarding value?
+    uint8_t new_priority = 0;
+    uint8_t new_flow_lbl = 0;
+    if (bestScore > 0) {
+        DscpPolicy* policy;
+        if (ipv4) {
+            policy = bpf_ipv4_dscp_policies_map_lookup_elem(&bestMatch);
+        } else {
+            policy = bpf_ipv6_dscp_policies_map_lookup_elem(&bestMatch);
+        }
+
+        if (policy) {
+            // TODO: if DSCP value is already set ignore?
+            if (ipv4) {
+                int ecn = tos & 3;
+                new_tos = (policy->dscpVal << 2) + ecn;
+            } else {
+                new_priority = (policy->dscpVal >> 2) + 0x60;
+                new_flow_lbl = ((policy->dscpVal & 0xf) << 6) + (flow_lbl >> 6);
+
+                // Set IPv6 curDscp value to stored value and recalulate priority
+                // and flow label during next use.
+                new_tos = policy->dscpVal;
             }
         }
+    } else return;
 
-        uint8_t newDscpVal = 0; // Can 0 be used as default forwarding value?
-        uint8_t curDscp = iph->tos & 252;
-        if (bestScore > 0) {
-            Ipv4Policy* policy = bpf_ipv4_dscp_policies_map_lookup_elem(&bestMatch);
-            if (policy) {
-                // TODO: if DSCP value is already set ignore?
-                // TODO: update checksum, for testing increment counter...
-                int ecn = iph->tos & 3;
-                newDscpVal = (policy->dscpVal << 2) + ecn;
-            }
-        }
+    RuleEntry value = {
+        .srcIp = srcIp,
+        .dstIp = dstIp,
+        .ifindex = skb->ifindex,
+        .srcPort = sport,
+        .dstPort = dport,
+        .proto = protocol,
+        .dscpVal = new_tos,
+    };
 
-        Ipv4RuleEntry value = {
-            .srcIp.s_addr = iph->saddr,
-            .dstIp.s_addr = iph->daddr,
-            .srcPort = udp->source,
-            .dstPort = udp->dest,
-            .proto = iph->protocol,
-            .dscpVal = newDscpVal,
-        };
-
-        if (!cookie)
-            return TC_ACT_PIPE;
-
-        // Update map
+    //Update map with new policy.
+    if (ipv4) {
         if (*selectedMap == MAP_A) {
             bpf_ipv4_socket_to_policies_map_A_update_elem(&cookie, &value, BPF_ANY);
         } else {
             bpf_ipv4_socket_to_policies_map_B_update_elem(&cookie, &value, BPF_ANY);
         }
-
-        // Need to store bytes after updating map or program will not load.
-        if (newDscpVal != curDscp) {
-            // 1 is the offset (Version/Header length)
-            int oldDscpVal = iph->tos >> 2;
-            bpf_l3_csum_replace(skb, 1, oldDscpVal, newDscpVal, sizeof(uint8_t));
-            bpf_skb_store_bytes(skb, 1, &newDscpVal, sizeof(uint8_t), 0);
-        }
-
-    } else if (skb->protocol == htons(ETH_P_IPV6)) { //maybe bpf_htons()
-        Ipv6RuleEntry* v6Policy;
+    } else {
         if (*selectedMap == MAP_A) {
-            v6Policy = bpf_ipv6_socket_to_policies_map_A_lookup_elem(&cookie);
+            bpf_ipv6_socket_to_policies_map_A_update_elem(&cookie, &value, BPF_ANY);
         } else {
-            v6Policy = bpf_ipv6_socket_to_policies_map_B_lookup_elem(&cookie);
+            bpf_ipv6_socket_to_policies_map_B_update_elem(&cookie, &value, BPF_ANY);
         }
+    }
 
-        if (!v6Policy)
-            return TC_ACT_PIPE;
+    // Need to store bytes after updating map or program will not load.
+    if (ipv4 && new_tos != (tos & 252)) {
+        int oldDscpVal = tos >> 2;
+        bpf_l3_csum_replace(skb, 1, oldDscpVal, new_tos, sizeof(uint8_t));
+        bpf_skb_store_bytes(skb, 1, &new_tos, sizeof(uint8_t), 0);
+    } else if (!ipv4 && (new_priority != priority || new_flow_lbl != flow_lbl)) {
+        bpf_skb_store_bytes(skb, 0, &new_priority, sizeof(uint8_t), 0);
+        bpf_skb_store_bytes(skb, 1, &new_flow_lbl, sizeof(uint8_t), 0);
+    }
+    return;
+}
 
-        // TODO: Add code to process IPv6 packet.
+DEFINE_BPF_PROG_KVER("schedcls/set_dscp_ether", AID_ROOT, AID_SYSTEM,
+                     schedcls_set_dscp_ether, KVER(5, 4, 0))
+(struct __sk_buff* skb) {
+
+    if (skb->pkt_type != PACKET_HOST) return TC_ACT_PIPE;
+
+    if (skb->protocol == htons(ETH_P_IP)) {
+        match_policy(skb, true, true);
+    } else if (skb->protocol == htons(ETH_P_IPV6)) {
+        match_policy(skb, false, true);
+    }
+
+    // Always return TC_ACT_PIPE
+    return TC_ACT_PIPE;
+}
+
+DEFINE_BPF_PROG_KVER("schedcls/set_dscp_raw_ip", AID_ROOT, AID_SYSTEM,
+                     schedcls_set_dscp_raw_ip, KVER(5, 4, 0))
+(struct __sk_buff* skb) {
+    if (skb->protocol == htons(ETH_P_IP)) {
+        match_policy(skb, true, false);
+    } else if (skb->protocol == htons(ETH_P_IPV6)) {
+        match_policy(skb, false, false);
     }
 
     // Always return TC_ACT_PIPE
diff --git a/bpf_progs/dscp_policy.h b/bpf_progs/dscp_policy.h
new file mode 100644
index 0000000..777c4ff
--- /dev/null
+++ b/bpf_progs/dscp_policy.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2022 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 MAX_POLICIES 16
+#define MAP_A 1
+#define MAP_B 2
+
+#define SRC_IP_MASK_FLAG     1
+#define DST_IP_MASK_FLAG     2
+#define SRC_PORT_MASK_FLAG   4
+#define DST_PORT_MASK_FLAG   8
+#define PROTO_MASK_FLAG      16
+
+#define STRUCT_SIZE(name, size) _Static_assert(sizeof(name) == (size), "Incorrect struct size.")
+
+#ifndef v6_equal
+#define v6_equal(a, b)    (a.s6_addr32[0] == b.s6_addr32[0] && \
+                 a.s6_addr32[1] == b.s6_addr32[1] && \
+                 a.s6_addr32[2] == b.s6_addr32[2] && \
+                 a.s6_addr32[3] == b.s6_addr32[3])
+#endif
+
+// TODO: these are already defined in packages/modules/Connectivity/bpf_progs/bpf_net_helpers.h.
+// smove to common location in future.
+static uint64_t (*bpf_get_socket_cookie)(struct __sk_buff* skb) =
+        (void*)BPF_FUNC_get_socket_cookie;
+static int (*bpf_skb_store_bytes)(struct __sk_buff* skb, __u32 offset, const void* from, __u32 len,
+                                  __u64 flags) = (void*)BPF_FUNC_skb_store_bytes;
+static int (*bpf_l3_csum_replace)(struct __sk_buff* skb, __u32 offset, __u64 from, __u64 to,
+                                  __u64 flags) = (void*)BPF_FUNC_l3_csum_replace;
+static long (*bpf_skb_ecn_set_ce)(struct __sk_buff* skb) =
+        (void*)BPF_FUNC_skb_ecn_set_ce;
+
+typedef struct {
+    struct in6_addr srcIp;
+    struct in6_addr dstIp;
+    uint32_t ifindex;
+    __be16 srcPort;
+    __be16 dstPortStart;
+    __be16 dstPortEnd;
+    uint8_t proto;
+    uint8_t dscpVal;
+    uint8_t presentFields;
+    uint8_t pad[3];
+} DscpPolicy;
+STRUCT_SIZE(DscpPolicy, 2 * 16 + 4 + 3 * 2 + 3 * 1 + 3);  // 48
+
+typedef struct {
+    struct in6_addr srcIp;
+    struct in6_addr dstIp;
+    __u32 ifindex;
+    __be16 srcPort;
+    __be16 dstPort;
+    __u8 proto;
+    __u8 dscpVal;
+    __u8 pad[2];
+} RuleEntry;
+STRUCT_SIZE(RuleEntry, 2 * 16 + 1 * 4 + 2 * 2 + 2 * 1 + 2);  // 44
\ No newline at end of file
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index d79bdb8..a0e75ec 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -3669,7 +3669,7 @@
                 }
                 case NetworkAgent.EVENT_REMOVE_ALL_DSCP_POLICIES: {
                     if (mDscpPolicyTracker != null) {
-                        mDscpPolicyTracker.removeAllDscpPolicies(nai);
+                        mDscpPolicyTracker.removeAllDscpPolicies(nai, true);
                     }
                     break;
                 }
@@ -4410,6 +4410,9 @@
     }
 
     private void destroyNativeNetwork(@NonNull NetworkAgentInfo nai) {
+        if (mDscpPolicyTracker != null) {
+            mDscpPolicyTracker.removeAllDscpPolicies(nai, false);
+        }
         try {
             mNetd.networkDestroy(nai.network.getNetId());
         } catch (RemoteException | ServiceSpecificException e) {
diff --git a/service/src/com/android/server/connectivity/DscpPolicyTracker.java b/service/src/com/android/server/connectivity/DscpPolicyTracker.java
index 53b276e..de9dfe3 100644
--- a/service/src/com/android/server/connectivity/DscpPolicyTracker.java
+++ b/service/src/com/android/server/connectivity/DscpPolicyTracker.java
@@ -19,6 +19,7 @@
 import static android.net.NetworkAgent.DSCP_POLICY_STATUS_DELETED;
 import static android.net.NetworkAgent.DSCP_POLICY_STATUS_INSUFFICIENT_PROCESSING_RESOURCES;
 import static android.net.NetworkAgent.DSCP_POLICY_STATUS_POLICY_NOT_FOUND;
+import static android.net.NetworkAgent.DSCP_POLICY_STATUS_REQUEST_DECLINED;
 import static android.net.NetworkAgent.DSCP_POLICY_STATUS_SUCCESS;
 import static android.system.OsConstants.ETH_P_ALL;
 
@@ -37,6 +38,7 @@
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.net.NetworkInterface;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -66,30 +68,68 @@
 
     private final BpfMap<Struct.U32, DscpPolicyValue> mBpfDscpIpv4Policies;
     private final BpfMap<Struct.U32, DscpPolicyValue> mBpfDscpIpv6Policies;
-    private final SparseIntArray mPolicyIdToBpfMapIndex;
+
+    // The actual policy rules used by the BPF code to process packets
+    // are in mBpfDscpIpv4Policies and mBpfDscpIpv4Policies. Both of
+    // these can contain up to MAX_POLICIES rules.
+    //
+    // A given policy always consumes one entry in both the IPv4 and
+    // IPv6 maps even if if's an IPv4-only or IPv6-only policy.
+    //
+    // Each interface index has a SparseIntArray of rules which maps a
+    // policy ID to the index of the corresponding rule in the maps.
+    // mIfaceIndexToPolicyIdBpfMapIndex maps the interface index to
+    // the per-interface SparseIntArray.
+    private final HashMap<Integer, SparseIntArray> mIfaceIndexToPolicyIdBpfMapIndex;
 
     public DscpPolicyTracker() throws ErrnoException {
         mAttachedIfaces = new HashSet<String>();
-
-        mPolicyIdToBpfMapIndex = new SparseIntArray(MAX_POLICIES);
+        mIfaceIndexToPolicyIdBpfMapIndex = new HashMap<Integer, SparseIntArray>();
         mBpfDscpIpv4Policies = new BpfMap<Struct.U32, DscpPolicyValue>(IPV4_POLICY_MAP_PATH,
                 BpfMap.BPF_F_RDWR, Struct.U32.class, DscpPolicyValue.class);
         mBpfDscpIpv6Policies = new BpfMap<Struct.U32, DscpPolicyValue>(IPV6_POLICY_MAP_PATH,
                 BpfMap.BPF_F_RDWR, Struct.U32.class, DscpPolicyValue.class);
     }
 
+    private boolean isUnusedIndex(int index) {
+        for (SparseIntArray ifacePolicies : mIfaceIndexToPolicyIdBpfMapIndex.values()) {
+            if (ifacePolicies.indexOfValue(index) >= 0) return false;
+        }
+        return true;
+    }
+
     private int getFirstFreeIndex() {
+        if (mIfaceIndexToPolicyIdBpfMapIndex.size() == 0) return 0;
         for (int i = 0; i < MAX_POLICIES; i++) {
-            if (mPolicyIdToBpfMapIndex.indexOfValue(i) < 0) return i;
+            if (isUnusedIndex(i)) {
+                return i;
+            }
         }
         return MAX_POLICIES;
     }
 
+    private int findIndex(int policyId, int ifIndex) {
+        SparseIntArray ifacePolicies = mIfaceIndexToPolicyIdBpfMapIndex.get(ifIndex);
+        if (ifacePolicies != null) {
+            final int existingIndex = ifacePolicies.get(policyId, -1);
+            if (existingIndex != -1) {
+                return existingIndex;
+            }
+        }
+
+        final int firstIndex = getFirstFreeIndex();
+        if (firstIndex >= MAX_POLICIES) {
+            // New policy is being added, but max policies has already been reached.
+            return -1;
+        }
+        return firstIndex;
+    }
+
     private void sendStatus(NetworkAgentInfo nai, int policyId, int status) {
         try {
             nai.networkAgent.onDscpPolicyStatusUpdated(policyId, status);
         } catch (RemoteException e) {
-            Log.d(TAG, "Failed update policy status: ", e);
+            Log.e(TAG, "Failed update policy status: ", e);
         }
     }
 
@@ -107,37 +147,43 @@
                         || policy.getSourceAddress() instanceof Inet6Address));
     }
 
-    private int addDscpPolicyInternal(DscpPolicy policy) {
+    private int getIfaceIndex(NetworkAgentInfo nai) {
+        String iface = nai.linkProperties.getInterfaceName();
+        NetworkInterface netIface;
+        try {
+            netIface = NetworkInterface.getByName(iface);
+        } catch (IOException e) {
+            Log.e(TAG, "Unable to get iface index for " + iface + ": " + e);
+            netIface = null;
+        }
+        return (netIface != null) ? netIface.getIndex() : 0;
+    }
+
+    private int addDscpPolicyInternal(DscpPolicy policy, int ifIndex) {
         // If there is no existing policy with a matching ID, and we are already at
         // the maximum number of policies then return INSUFFICIENT_PROCESSING_RESOURCES.
-        final int existingIndex = mPolicyIdToBpfMapIndex.get(policy.getPolicyId(), -1);
-        if (existingIndex == -1 && mPolicyIdToBpfMapIndex.size() >= MAX_POLICIES) {
-            return DSCP_POLICY_STATUS_INSUFFICIENT_PROCESSING_RESOURCES;
+        SparseIntArray ifacePolicies = mIfaceIndexToPolicyIdBpfMapIndex.get(ifIndex);
+        if (ifacePolicies == null) {
+            ifacePolicies = new SparseIntArray(MAX_POLICIES);
         }
 
         // Currently all classifiers are supported, if any are removed return
         // DSCP_POLICY_STATUS_REQUESTED_CLASSIFIER_NOT_SUPPORTED,
         // and for any other generic error DSCP_POLICY_STATUS_REQUEST_DECLINED
 
-        int addIndex = 0;
-        // If a policy with a matching ID exists, replace it, otherwise use the next free
-        // index for the policy.
-        if (existingIndex != -1) {
-            addIndex = mPolicyIdToBpfMapIndex.get(policy.getPolicyId());
-        } else {
-            addIndex = getFirstFreeIndex();
+        final int addIndex = findIndex(policy.getPolicyId(), ifIndex);
+        if (addIndex == -1) {
+            return DSCP_POLICY_STATUS_INSUFFICIENT_PROCESSING_RESOURCES;
         }
 
         try {
-            mPolicyIdToBpfMapIndex.put(policy.getPolicyId(), addIndex);
-
             // Add v4 policy to mBpfDscpIpv4Policies if source and destination address
-            // are both null or if they are both instances of Inet6Address.
+            // are both null or if they are both instances of Inet4Address.
             if (matchesIpv4(policy)) {
                 mBpfDscpIpv4Policies.insertOrReplaceEntry(
                         new Struct.U32(addIndex),
                         new DscpPolicyValue(policy.getSourceAddress(),
-                            policy.getDestinationAddress(),
+                            policy.getDestinationAddress(), ifIndex,
                             policy.getSourcePort(), policy.getDestinationPortRange(),
                             (short) policy.getProtocol(), (short) policy.getDscpValue()));
             }
@@ -148,10 +194,16 @@
                 mBpfDscpIpv6Policies.insertOrReplaceEntry(
                         new Struct.U32(addIndex),
                         new DscpPolicyValue(policy.getSourceAddress(),
-                                policy.getDestinationAddress(),
+                                policy.getDestinationAddress(), ifIndex,
                                 policy.getSourcePort(), policy.getDestinationPortRange(),
                                 (short) policy.getProtocol(), (short) policy.getDscpValue()));
             }
+
+            ifacePolicies.put(policy.getPolicyId(), addIndex);
+            // Only add the policy to the per interface map if the policy was successfully
+            // added to both bpf maps above. It is safe to assume that if insert fails for
+            // one map then it fails for both.
+            mIfaceIndexToPolicyIdBpfMapIndex.put(ifIndex, ifacePolicies);
         } catch (ErrnoException e) {
             Log.e(TAG, "Failed to insert policy into map: ", e);
             return DSCP_POLICY_STATUS_INSUFFICIENT_PROCESSING_RESOURCES;
@@ -166,6 +218,7 @@
      *
      * DSCP_POLICY_STATUS_SUCCESS - if policy was added successfully
      * DSCP_POLICY_STATUS_INSUFFICIENT_PROCESSING_RESOURCES - if max policies were already set
+     * DSCP_POLICY_STATUS_REQUEST_DECLINED - Interface index was invalid
      */
     public void addDscpPolicy(NetworkAgentInfo nai, DscpPolicy policy) {
         if (!mAttachedIfaces.contains(nai.linkProperties.getInterfaceName())) {
@@ -177,11 +230,19 @@
             }
         }
 
-        int status = addDscpPolicyInternal(policy);
+        final int ifIndex = getIfaceIndex(nai);
+        if (ifIndex == 0) {
+            Log.e(TAG, "Iface index is invalid");
+            sendStatus(nai, policy.getPolicyId(), DSCP_POLICY_STATUS_REQUEST_DECLINED);
+            return;
+        }
+
+        int status = addDscpPolicyInternal(policy, ifIndex);
         sendStatus(nai, policy.getPolicyId(), status);
     }
 
-    private void removePolicyFromMap(NetworkAgentInfo nai, int policyId, int index) {
+    private void removePolicyFromMap(NetworkAgentInfo nai, int policyId, int index,
+            boolean sendCallback) {
         int status = DSCP_POLICY_STATUS_POLICY_NOT_FOUND;
         try {
             mBpfDscpIpv4Policies.replaceEntry(new Struct.U32(index), DscpPolicyValue.NONE);
@@ -191,7 +252,9 @@
             Log.e(TAG, "Failed to delete policy from map: ", e);
         }
 
-        sendStatus(nai, policyId, status);
+        if (sendCallback) {
+            sendStatus(nai, policyId, status);
+        }
     }
 
     /**
@@ -204,36 +267,44 @@
             return;
         }
 
-        if (mPolicyIdToBpfMapIndex.get(policyId, -1) != -1) {
-            removePolicyFromMap(nai, policyId, mPolicyIdToBpfMapIndex.get(policyId));
-            mPolicyIdToBpfMapIndex.delete(policyId);
+        SparseIntArray ifacePolicies = mIfaceIndexToPolicyIdBpfMapIndex.get(getIfaceIndex(nai));
+        if (ifacePolicies == null) return;
+
+        final int existingIndex = ifacePolicies.get(policyId, -1);
+        if (existingIndex == -1) {
+            Log.e(TAG, "Policy " + policyId + " does not exist in map.");
+            sendStatus(nai, policyId, DSCP_POLICY_STATUS_POLICY_NOT_FOUND);
+            return;
         }
 
-        // TODO: detach should only occur if no more policies are present on the nai's iface.
-        if (mPolicyIdToBpfMapIndex.size() == 0) {
+        removePolicyFromMap(nai, policyId, existingIndex, true);
+        ifacePolicies.delete(policyId);
+
+        if (ifacePolicies.size() == 0) {
             detachProgram(nai.linkProperties.getInterfaceName());
         }
     }
 
     /**
-     * Remove all DSCP policies and detach program.
+     * Remove all DSCP policies and detach program. Send callback if requested.
      */
-    // TODO: Remove all should only remove policies from corresponding nai iface.
-    public void removeAllDscpPolicies(NetworkAgentInfo nai) {
+    public void removeAllDscpPolicies(NetworkAgentInfo nai, boolean sendCallback) {
         if (!mAttachedIfaces.contains(nai.linkProperties.getInterfaceName())) {
             // Nothing to remove since program is not attached. Send update for policy
             // id 0. The status update must contain a policy ID, and 0 is an invalid id.
-            sendStatus(nai, 0, DSCP_POLICY_STATUS_SUCCESS);
+            if (sendCallback) {
+                sendStatus(nai, 0, DSCP_POLICY_STATUS_SUCCESS);
+            }
             return;
         }
 
-        for (int i = 0; i < mPolicyIdToBpfMapIndex.size(); i++) {
-            removePolicyFromMap(nai, mPolicyIdToBpfMapIndex.keyAt(i),
-                    mPolicyIdToBpfMapIndex.valueAt(i));
+        SparseIntArray ifacePolicies = mIfaceIndexToPolicyIdBpfMapIndex.get(getIfaceIndex(nai));
+        if (ifacePolicies == null) return;
+        for (int i = 0; i < ifacePolicies.size(); i++) {
+            removePolicyFromMap(nai, ifacePolicies.keyAt(i), ifacePolicies.valueAt(i),
+                    sendCallback);
         }
-        mPolicyIdToBpfMapIndex.clear();
-
-        // Can detach program since no policies are active.
+        ifacePolicies.clear();
         detachProgram(nai.linkProperties.getInterfaceName());
     }
 
@@ -241,12 +312,12 @@
      * Attach BPF program
      */
     private boolean attachProgram(@NonNull String iface) {
-        // TODO: attach needs to be per iface not program.
-
         try {
             NetworkInterface netIface = NetworkInterface.getByName(iface);
+            boolean isEth = TcUtils.isEthernet(iface);
+            String path = PROG_PATH + (isEth ? "_ether" : "_raw_ip");
             TcUtils.tcFilterAddDevBpf(netIface.getIndex(), false, PRIO_DSCP, (short) ETH_P_ALL,
-                    PROG_PATH);
+                    path);
         } catch (IOException e) {
             Log.e(TAG, "Unable to attach to TC on " + iface + ": " + e);
             return false;
@@ -264,9 +335,9 @@
             if (netIface != null) {
                 TcUtils.tcFilterDelDev(netIface.getIndex(), false, PRIO_DSCP, (short) ETH_P_ALL);
             }
+            mAttachedIfaces.remove(iface);
         } catch (IOException e) {
             Log.e(TAG, "Unable to detach to TC on " + iface + ": " + e);
         }
-        mAttachedIfaces.remove(iface);
     }
 }
diff --git a/service/src/com/android/server/connectivity/DscpPolicyValue.java b/service/src/com/android/server/connectivity/DscpPolicyValue.java
index cb40306..6e4e7eb 100644
--- a/service/src/com/android/server/connectivity/DscpPolicyValue.java
+++ b/service/src/com/android/server/connectivity/DscpPolicyValue.java
@@ -31,29 +31,31 @@
 public class DscpPolicyValue extends Struct {
     private static final String TAG = DscpPolicyValue.class.getSimpleName();
 
-    // TODO: add the interface index.
     @Field(order = 0, type = Type.ByteArray, arraysize = 16)
     public final byte[] src46;
 
     @Field(order = 1, type = Type.ByteArray, arraysize = 16)
     public final byte[] dst46;
 
-    @Field(order = 2, type = Type.UBE16)
-    public final int srcPort;
+    @Field(order = 2, type = Type.U32)
+    public final long ifIndex;
 
     @Field(order = 3, type = Type.UBE16)
-    public final int dstPortStart;
+    public final int srcPort;
 
     @Field(order = 4, type = Type.UBE16)
+    public final int dstPortStart;
+
+    @Field(order = 5, type = Type.UBE16)
     public final int dstPortEnd;
 
-    @Field(order = 5, type = Type.U8)
+    @Field(order = 6, type = Type.U8)
     public final short proto;
 
-    @Field(order = 6, type = Type.U8)
+    @Field(order = 7, type = Type.U8)
     public final short dscp;
 
-    @Field(order = 7, type = Type.U8, padding = 3)
+    @Field(order = 8, type = Type.U8, padding = 3)
     public final short mask;
 
     private static final int SRC_IP_MASK = 0x1;
@@ -69,6 +71,7 @@
         return true;
     }
 
+    // TODO:  move to frameworks/libs/net and have this and BpfCoordinator import it.
     private byte[] toIpv4MappedAddressBytes(InetAddress ia) {
         final byte[] addr6 = new byte[16];
         if (ia != null) {
@@ -117,13 +120,12 @@
         return mask;
     }
 
-    // This constructor is necessary for BpfMap#getValue since all values must be
-    // in the constructor.
-    public DscpPolicyValue(final InetAddress src46, final InetAddress dst46, final int srcPort,
-            final int dstPortStart, final int dstPortEnd, final short proto,
+    private DscpPolicyValue(final InetAddress src46, final InetAddress dst46, final long ifIndex,
+            final int srcPort, final int dstPortStart, final int dstPortEnd, final short proto,
             final short dscp) {
         this.src46 = toAddressField(src46);
         this.dst46 = toAddressField(dst46);
+        this.ifIndex = ifIndex;
 
         // These params need to be stored as 0 because uints are used in BpfMap.
         // If they are -1 BpfMap write will throw errors.
@@ -138,15 +140,15 @@
         this.mask = makeMask(this.src46, this.dst46, srcPort, dstPortStart, proto, dscp);
     }
 
-    public DscpPolicyValue(final InetAddress src46, final InetAddress dst46, final int srcPort,
-            final Range<Integer> dstPort, final short proto,
+    public DscpPolicyValue(final InetAddress src46, final InetAddress dst46, final long ifIndex,
+            final int srcPort, final Range<Integer> dstPort, final short proto,
             final short dscp) {
-        this(src46, dst46, srcPort, dstPort != null ? dstPort.getLower() : -1,
+        this(src46, dst46, ifIndex, srcPort, dstPort != null ? dstPort.getLower() : -1,
                 dstPort != null ? dstPort.getUpper() : -1, proto, dscp);
     }
 
     public static final DscpPolicyValue NONE = new DscpPolicyValue(
-            null /* src46 */, null /* dst46 */, -1 /* srcPort */,
+            null /* src46 */, null /* dst46 */, 0 /* ifIndex */, -1 /* srcPort */,
             -1 /* dstPortStart */, -1 /* dstPortEnd */, (short) -1 /* proto */,
             (short) 0 /* dscp */);
 
@@ -170,9 +172,9 @@
 
         try {
             return String.format(
-                    "src46: %s, dst46: %s, srcPort: %d, dstPortStart: %d, dstPortEnd: %d,"
-                    + " protocol: %d, dscp %s", srcIpString, dstIpString, srcPort, dstPortStart,
-                    dstPortEnd, proto, dscp);
+                    "src46: %s, dst46: %s, ifIndex: %d, srcPort: %d, dstPortStart: %d,"
+                    + " dstPortEnd: %d, protocol: %d, dscp %s", srcIpString, dstIpString,
+                    ifIndex, srcPort, dstPortStart, dstPortEnd, proto, dscp);
         } catch (IllegalArgumentException e) {
             return String.format("String format error: " + e);
         }
diff --git a/tests/cts/net/src/android/net/cts/DscpPolicyTest.kt b/tests/cts/net/src/android/net/cts/DscpPolicyTest.kt
index e8add6b..1e42fe6 100644
--- a/tests/cts/net/src/android/net/cts/DscpPolicyTest.kt
+++ b/tests/cts/net/src/android/net/cts/DscpPolicyTest.kt
@@ -48,9 +48,11 @@
 import android.platform.test.annotations.AppModeFull
 import android.system.Os
 import android.system.OsConstants.AF_INET
+import android.system.OsConstants.AF_INET6
 import android.system.OsConstants.IPPROTO_UDP
 import android.system.OsConstants.SOCK_DGRAM
 import android.system.OsConstants.SOCK_NONBLOCK
+import android.util.Log
 import android.util.Range
 import androidx.test.InstrumentationRegistry
 import androidx.test.runner.AndroidJUnit4
@@ -71,6 +73,8 @@
 import org.junit.Test
 import org.junit.runner.RunWith
 import java.net.Inet4Address
+import java.net.Inet6Address
+import java.net.InetAddress
 import java.nio.ByteBuffer
 import java.nio.ByteOrder
 import java.util.regex.Pattern
@@ -81,6 +85,9 @@
 
 private const val MAX_PACKET_LENGTH = 1500
 
+private const val IP4_PREFIX_LEN = 32
+private const val IP6_PREFIX_LEN = 128
+
 private val instrumentation: Instrumentation
     get() = InstrumentationRegistry.getInstrumentation()
 
@@ -97,6 +104,9 @@
     private val LOCAL_IPV4_ADDRESS = InetAddresses.parseNumericAddress("192.0.2.1")
     private val TEST_TARGET_IPV4_ADDR =
             InetAddresses.parseNumericAddress("8.8.8.8") as Inet4Address
+    private val LOCAL_IPV6_ADDRESS = InetAddresses.parseNumericAddress("2001:db8::1")
+    private val TEST_TARGET_IPV6_ADDR =
+            InetAddresses.parseNumericAddress("2001:4860:4860::8888") as Inet6Address
 
     private val realContext = InstrumentationRegistry.getContext()
     private val cm = realContext.getSystemService(ConnectivityManager::class.java)
@@ -132,7 +142,9 @@
         runAsShell(MANAGE_TEST_NETWORKS) {
             val tnm = realContext.getSystemService(TestNetworkManager::class.java)
 
-            iface = tnm.createTunInterface(Array(1) { LinkAddress(LOCAL_IPV4_ADDRESS, 32) })
+            iface = tnm.createTunInterface(arrayOf(
+                    LinkAddress(LOCAL_IPV4_ADDRESS, IP4_PREFIX_LEN),
+                    LinkAddress(LOCAL_IPV6_ADDRESS, IP6_PREFIX_LEN)))
             assertNotNull(iface)
         }
 
@@ -154,6 +166,8 @@
 
         // reader.stop() cleans up tun fd
         reader.handler.post { reader.stop() }
+        if (iface.fileDescriptor.fileDescriptor != null)
+            Os.close(iface.fileDescriptor.fileDescriptor)
         handlerThread.quitSafely()
     }
 
@@ -196,9 +210,11 @@
             }
         }
         val lp = LinkProperties().apply {
-            addLinkAddress(LinkAddress(LOCAL_IPV4_ADDRESS, 32))
+            addLinkAddress(LinkAddress(LOCAL_IPV4_ADDRESS, IP4_PREFIX_LEN))
+            addLinkAddress(LinkAddress(LOCAL_IPV6_ADDRESS, IP6_PREFIX_LEN))
             addRoute(RouteInfo(IpPrefix("0.0.0.0/0"), null, null))
-            setInterfaceName(iface.getInterfaceName())
+            addRoute(RouteInfo(InetAddress.getByName("fe80::1234")))
+            setInterfaceName(specifier)
         }
         val config = NetworkAgentConfig.Builder().build()
         val agent = TestableNetworkAgent(context, handlerThread.looper, nc, lp, config)
@@ -218,47 +234,114 @@
         eachByte -> "%02x".format(eachByte)
     }
 
-    fun checkDscpValue(
+    fun sendPacket(
         agent: TestableNetworkAgent,
-        callback: TestableNetworkCallback,
-        dscpValue: Int = 0,
-        dstPort: Int = 0
+        sendV6: Boolean,
+        dstPort: Int = 0,
     ) {
         val testString = "test string"
         val testPacket = ByteBuffer.wrap(testString.toByteArray(Charsets.UTF_8))
         var packetFound = false
 
-        val socket = Os.socket(AF_INET, SOCK_DGRAM or SOCK_NONBLOCK, IPPROTO_UDP)
+        val socket = Os.socket(if (sendV6) AF_INET6 else AF_INET, SOCK_DGRAM or SOCK_NONBLOCK,
+                IPPROTO_UDP)
         agent.network.bindSocket(socket)
 
         val originalPacket = testPacket.readAsArray()
-        Os.sendto(socket, originalPacket, 0 /* bytesOffset */, originalPacket.size,
-                0 /* flags */, TEST_TARGET_IPV4_ADDR, dstPort)
-
+        Os.sendto(socket, originalPacket, 0 /* bytesOffset */, originalPacket.size, 0 /* flags */,
+                if(sendV6) TEST_TARGET_IPV6_ADDR else TEST_TARGET_IPV4_ADDR, dstPort)
         Os.close(socket)
+    }
+
+    fun parseV4PacketDscp(buffer : ByteBuffer) : Int {
+        val ip_ver = buffer.get()
+        val tos = buffer.get()
+        val length = buffer.getShort()
+        val id = buffer.getShort()
+        val offset = buffer.getShort()
+        val ttl = buffer.get()
+        val ipType = buffer.get()
+        val checksum = buffer.getShort()
+        return tos.toInt().shr(2)
+    }
+
+    fun parseV6PacketDscp(buffer : ByteBuffer) : Int {
+        val ip_ver = buffer.get()
+        val tc = buffer.get()
+        val fl = buffer.getShort()
+        val length = buffer.getShort()
+        val proto = buffer.get()
+        val hop = buffer.get()
+        // DSCP is bottom 4 bits of ip_ver and top 2 of tc.
+        val ip_ver_bottom = ip_ver.toInt().and(0xf)
+        val tc_dscp = tc.toInt().shr(6)
+        return ip_ver_bottom.toInt().shl(2) + tc_dscp
+    }
+
+    fun parsePacketIp(
+        buffer : ByteBuffer,
+        sendV6 : Boolean,
+    ) : Boolean {
+        val ipAddr = if (sendV6) ByteArray(16) else ByteArray(4)
+        buffer.get(ipAddr)
+        val srcIp = if (sendV6) Inet6Address.getByAddress(ipAddr)
+                else Inet4Address.getByAddress(ipAddr)
+        buffer.get(ipAddr)
+        val dstIp = if (sendV6) Inet6Address.getByAddress(ipAddr)
+                else Inet4Address.getByAddress(ipAddr)
+
+        Log.e(TAG, "IP Src:" + srcIp + " dst: " + dstIp)
+
+        if ((sendV6 && srcIp == LOCAL_IPV6_ADDRESS && dstIp == TEST_TARGET_IPV6_ADDR) ||
+                (!sendV6 && srcIp == LOCAL_IPV4_ADDRESS && dstIp == TEST_TARGET_IPV4_ADDR)) {
+            Log.e(TAG, "IP return true");
+            return true
+        }
+        Log.e(TAG, "IP return false");
+        return false
+    }
+
+    fun parsePacketPort(
+        buffer : ByteBuffer,
+        srcPort : Int,
+        dstPort : Int
+    ) : Boolean {
+        if (srcPort == 0 && dstPort == 0) return true
+
+        val packetSrcPort = buffer.getShort().toInt()
+        val packetDstPort = buffer.getShort().toInt()
+
+        Log.e(TAG, "Port Src:" + packetSrcPort + " dst: " + packetDstPort)
+
+        if ((srcPort == 0 || (srcPort != 0 && srcPort == packetSrcPort)) &&
+                (dstPort == 0 || (dstPort != 0 && dstPort == packetDstPort))) {
+            Log.e(TAG, "Port return true");
+            return true
+        }
+        Log.e(TAG, "Port return false");
+        return false
+    }
+
+    fun validatePacket(
+        agent : TestableNetworkAgent,
+        sendV6 : Boolean = false,
+        dscpValue : Int = 0,
+        dstPort : Int = 0,
+    ) {
+        var packetFound = false;
+        sendPacket(agent, sendV6, dstPort)
+        // TODO: grab source port from socket in sendPacket
+
+        Log.e(TAG, "find DSCP value:" + dscpValue)
         generateSequence { reader.poll(PACKET_TIMEOUT_MS) }.forEach { packet ->
             val buffer = ByteBuffer.wrap(packet, 0, packet.size).order(ByteOrder.BIG_ENDIAN)
-            val ip_ver = buffer.get()
-            val tos = buffer.get()
-            val length = buffer.getShort()
-            val id = buffer.getShort()
-            val offset = buffer.getShort()
-            val ttl = buffer.get()
-            val ipType = buffer.get()
-            val checksum = buffer.getShort()
+            val dscp = if (sendV6) parseV6PacketDscp(buffer) else parseV4PacketDscp(buffer)
+            Log.e(TAG, "DSCP value:" + dscp)
 
-            val ipAddr = ByteArray(4)
-            buffer.get(ipAddr)
-            val srcIp = Inet4Address.getByAddress(ipAddr)
-            buffer.get(ipAddr)
-            val dstIp = Inet4Address.getByAddress(ipAddr)
-            val packetSrcPort = buffer.getShort().toInt()
-            val packetDstPort = buffer.getShort().toInt()
-
-            // TODO: Add source port comparison.
-            if (srcIp == LOCAL_IPV4_ADDRESS && dstIp == TEST_TARGET_IPV4_ADDR &&
-                    packetDstPort == dstPort) {
-                assertEquals(dscpValue, (tos.toInt().shr(2)))
+            // TODO: Add source port comparison. Use 0 for now.
+            if (parsePacketIp(buffer, sendV6) && parsePacketPort(buffer, 0, dstPort)) {
+                Log.e(TAG, "DSCP value found")
+                assertEquals(dscpValue, dscp)
                 packetFound = true
             }
         }
@@ -275,12 +358,12 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(policyId, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_DELETED, it.status)
-            checkDscpValue(agent, callback, dstPort = portNumber)
         }
     }
 
     @Test
-    fun testDscpPolicyAddPolicies(): Unit = createConnectedNetworkAgent().let { (agent, callback) ->
+    fun testDscpPolicyAddPolicies(): Unit = createConnectedNetworkAgent().let {
+                (agent, callback) ->
         val policy = DscpPolicy.Builder(1, 1)
                 .setDestinationPortRange(Range(4444, 4444)).build()
         agent.sendAddDscpPolicy(policy)
@@ -288,8 +371,7 @@
             assertEquals(1, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
         }
-
-        checkDscpValue(agent, callback, dscpValue = 1, dstPort = 4444)
+        validatePacket(agent, dscpValue = 1, dstPort = 4444)
 
         agent.sendRemoveDscpPolicy(1)
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
@@ -298,15 +380,54 @@
         }
 
         val policy2 = DscpPolicy.Builder(1, 4)
-                .setDestinationPortRange(Range(5555, 5555)).setSourceAddress(LOCAL_IPV4_ADDRESS)
-                .setDestinationAddress(TEST_TARGET_IPV4_ADDR).setProtocol(IPPROTO_UDP).build()
+                .setDestinationPortRange(Range(5555, 5555))
+                .setDestinationAddress(TEST_TARGET_IPV4_ADDR)
+                .setSourceAddress(LOCAL_IPV4_ADDRESS)
+                .setProtocol(IPPROTO_UDP).build()
         agent.sendAddDscpPolicy(policy2)
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(1, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
         }
 
-        checkDscpValue(agent, callback, dscpValue = 4, dstPort = 5555)
+        validatePacket(agent, dscpValue = 4, dstPort = 5555)
+
+        agent.sendRemoveDscpPolicy(1)
+        agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
+            assertEquals(1, it.policyId)
+            assertEquals(DSCP_POLICY_STATUS_DELETED, it.status)
+        }
+    }
+
+    @Test
+    fun testDscpPolicyAddV6Policies(): Unit = createConnectedNetworkAgent().let {
+                (agent, callback) ->
+        val policy = DscpPolicy.Builder(1, 1)
+                .setDestinationPortRange(Range(4444, 4444)).build()
+        agent.sendAddDscpPolicy(policy)
+        agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
+            assertEquals(1, it.policyId)
+            assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
+        }
+        validatePacket(agent, true, dscpValue = 1, dstPort = 4444)
+
+        agent.sendRemoveDscpPolicy(1)
+        agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
+            assertEquals(1, it.policyId)
+            assertEquals(DSCP_POLICY_STATUS_DELETED, it.status)
+        }
+
+        val policy2 = DscpPolicy.Builder(1, 4)
+                .setDestinationPortRange(Range(5555, 5555))
+                .setDestinationAddress(TEST_TARGET_IPV6_ADDR)
+                .setSourceAddress(LOCAL_IPV6_ADDRESS)
+                .setProtocol(IPPROTO_UDP).build()
+        agent.sendAddDscpPolicy(policy2)
+        agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
+            assertEquals(1, it.policyId)
+            assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
+        }
+        validatePacket(agent, true, dscpValue = 4, dstPort = 5555)
 
         agent.sendRemoveDscpPolicy(1)
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
@@ -324,7 +445,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(1, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 1111)
+            validatePacket(agent, dscpValue = 1, dstPort = 1111)
         }
 
         val policy2 = DscpPolicy.Builder(2, 1).setDestinationPortRange(Range(2222, 2222)).build()
@@ -332,7 +453,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(2, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 2222)
+            validatePacket(agent, dscpValue = 1, dstPort = 2222)
         }
 
         val policy3 = DscpPolicy.Builder(3, 1).setDestinationPortRange(Range(3333, 3333)).build()
@@ -340,13 +461,16 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(3, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 3333)
+            validatePacket(agent, dscpValue = 1, dstPort = 3333)
         }
 
         /* Remove Policies and check CE is no longer set */
         doRemovePolicyTest(agent, callback, 1)
+        validatePacket(agent, dscpValue = 0, dstPort = 1111)
         doRemovePolicyTest(agent, callback, 2)
+        validatePacket(agent, dscpValue = 0, dstPort = 2222)
         doRemovePolicyTest(agent, callback, 3)
+        validatePacket(agent, dscpValue = 0, dstPort = 3333)
     }
 
     @Test
@@ -357,7 +481,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(1, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 1111)
+            validatePacket(agent, dscpValue = 1, dstPort = 1111)
         }
         doRemovePolicyTest(agent, callback, 1)
 
@@ -366,7 +490,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(2, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 2222)
+            validatePacket(agent, dscpValue = 1, dstPort = 2222)
         }
         doRemovePolicyTest(agent, callback, 2)
 
@@ -375,7 +499,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(3, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 3333)
+            validatePacket(agent, dscpValue = 1, dstPort = 3333)
         }
         doRemovePolicyTest(agent, callback, 3)
     }
@@ -389,7 +513,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(1, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 1111)
+            validatePacket(agent, dscpValue = 1, dstPort = 1111)
         }
 
         val policy2 = DscpPolicy.Builder(2, 1).setDestinationPortRange(Range(2222, 2222)).build()
@@ -397,7 +521,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(2, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 2222)
+            validatePacket(agent, dscpValue = 1, dstPort = 2222)
         }
 
         val policy3 = DscpPolicy.Builder(3, 1).setDestinationPortRange(Range(3333, 3333)).build()
@@ -405,7 +529,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(3, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 3333)
+            validatePacket(agent, dscpValue = 1, dstPort = 3333)
         }
 
         /* Remove Policies and check CE is no longer set */
@@ -423,14 +547,15 @@
     }
 
     @Test
-    fun testRemoveAllDscpPolicies(): Unit = createConnectedNetworkAgent().let { (agent, callback) ->
+    fun testRemoveAllDscpPolicies(): Unit = createConnectedNetworkAgent().let {
+                (agent, callback) ->
         val policy = DscpPolicy.Builder(1, 1)
                 .setDestinationPortRange(Range(1111, 1111)).build()
         agent.sendAddDscpPolicy(policy)
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(1, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 1111)
+            validatePacket(agent, dscpValue = 1, dstPort = 1111)
         }
 
         val policy2 = DscpPolicy.Builder(2, 1)
@@ -439,7 +564,7 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(2, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 2222)
+            validatePacket(agent, dscpValue = 1, dstPort = 2222)
         }
 
         val policy3 = DscpPolicy.Builder(3, 1)
@@ -448,24 +573,24 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(3, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 3333)
+            validatePacket(agent, dscpValue = 1, dstPort = 3333)
         }
 
         agent.sendRemoveAllDscpPolicies()
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(1, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_DELETED, it.status)
-            checkDscpValue(agent, callback, dstPort = 1111)
+            validatePacket(agent, false, dstPort = 1111)
         }
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(2, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_DELETED, it.status)
-            checkDscpValue(agent, callback, dstPort = 2222)
+            validatePacket(agent, false, dstPort = 2222)
         }
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(3, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_DELETED, it.status)
-            checkDscpValue(agent, callback, dstPort = 3333)
+            validatePacket(agent, false, dstPort = 3333)
         }
     }
 
@@ -477,12 +602,9 @@
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
             assertEquals(1, it.policyId)
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 4444)
+            validatePacket(agent, dscpValue = 1, dstPort = 4444)
         }
 
-        // TODO: send packet on socket and confirm that changing the DSCP policy
-        // updates the mark to the new value.
-
         val policy2 = DscpPolicy.Builder(1, 1).setDestinationPortRange(Range(5555, 5555)).build()
         agent.sendAddDscpPolicy(policy2)
         agent.expectCallback<OnDscpPolicyStatusUpdated>().let {
@@ -490,8 +612,8 @@
             assertEquals(DSCP_POLICY_STATUS_SUCCESS, it.status)
 
             // Sending packet with old policy should fail
-            checkDscpValue(agent, callback, dstPort = 4444)
-            checkDscpValue(agent, callback, dscpValue = 1, dstPort = 5555)
+            validatePacket(agent, dscpValue = 0, dstPort = 4444)
+            validatePacket(agent, dscpValue = 1, dstPort = 5555)
         }
 
         agent.sendRemoveDscpPolicy(1)