eliminate bpf_progs/netd.h (via cut'n'paste into netd.c)

This file isn't used anywhere else, and the things it contains
should either be in the netd.c implementation or in a different
header file shared with netd's C++ code.

Step one eliminates it, and moves its content into the .c program.

Test: builds, atest
Bug: 146787904
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I53348bda8c8e84210735a3324fbb6f48396c8427
diff --git a/bpf_progs/netd.c b/bpf_progs/netd.c
index 3212314..c018e5d 100644
--- a/bpf_progs/netd.c
+++ b/bpf_progs/netd.c
@@ -14,9 +14,232 @@
  * limitations under the License.
  */
 
-#include "netd.h"
+#include <bpf_helpers.h>
 #include <linux/bpf.h>
+#include <linux/if.h>
+#include <linux/if_ether.h>
 #include <linux/if_packet.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include "bpf_net_helpers.h"
+#include "netdbpf/bpf_shared.h"
+
+typedef struct {
+    uint32_t uid;
+    uint32_t tag;
+} uid_tag;
+
+typedef struct {
+    uint32_t uid;
+    uint32_t tag;
+    uint32_t counterSet;
+    uint32_t ifaceIndex;
+} stats_key;
+
+typedef struct {
+    uint64_t rxPackets;
+    uint64_t rxBytes;
+    uint64_t txPackets;
+    uint64_t txBytes;
+} stats_value;
+
+typedef struct {
+    char name[IFNAMSIZ];
+} IfaceValue;
+
+// This is defined for cgroup bpf filter only.
+#define BPF_PASS 1
+#define BPF_DROP 0
+
+// This is used for xt_bpf program only.
+#define BPF_NOMATCH 0
+#define BPF_MATCH 1
+
+#define BPF_EGRESS 0
+#define BPF_INGRESS 1
+
+#define IP_PROTO_OFF offsetof(struct iphdr, protocol)
+#define IPV6_PROTO_OFF offsetof(struct ipv6hdr, nexthdr)
+#define IPPROTO_IHL_OFF 0
+#define TCP_FLAG_OFF 13
+#define RST_OFFSET 2
+
+DEFINE_BPF_MAP(cookie_tag_map, HASH, uint64_t, uid_tag, COOKIE_UID_MAP_SIZE)
+DEFINE_BPF_MAP(uid_counterset_map, HASH, uint32_t, uint8_t, UID_COUNTERSET_MAP_SIZE)
+DEFINE_BPF_MAP(app_uid_stats_map, HASH, uint32_t, stats_value, APP_STATS_MAP_SIZE)
+DEFINE_BPF_MAP(stats_map_A, HASH, stats_key, stats_value, STATS_MAP_SIZE)
+DEFINE_BPF_MAP(stats_map_B, HASH, stats_key, stats_value, STATS_MAP_SIZE)
+DEFINE_BPF_MAP(iface_stats_map, HASH, uint32_t, stats_value, IFACE_STATS_MAP_SIZE)
+DEFINE_BPF_MAP(configuration_map, HASH, uint32_t, uint8_t, CONFIGURATION_MAP_SIZE)
+DEFINE_BPF_MAP(uid_owner_map, HASH, uint32_t, UidOwnerValue, UID_OWNER_MAP_SIZE)
+
+/* never actually used from ebpf */
+DEFINE_BPF_MAP_NO_ACCESSORS(iface_index_name_map, HASH, uint32_t, IfaceValue,
+                            IFACE_INDEX_NAME_MAP_SIZE)
+
+static __always_inline int is_system_uid(uint32_t uid) {
+    return (uid <= MAX_SYSTEM_UID) && (uid >= MIN_SYSTEM_UID);
+}
+
+#define DEFINE_UPDATE_STATS(the_stats_map, TypeOfKey)                                          \
+    static __always_inline inline void update_##the_stats_map(struct __sk_buff* skb,           \
+                                                              int direction, TypeOfKey* key) { \
+        stats_value* value;                                                                    \
+        value = bpf_##the_stats_map##_lookup_elem(key);                                        \
+        if (!value) {                                                                          \
+            stats_value newValue = {};                                                         \
+            bpf_##the_stats_map##_update_elem(key, &newValue, BPF_NOEXIST);                    \
+            value = bpf_##the_stats_map##_lookup_elem(key);                                    \
+        }                                                                                      \
+        if (value) {                                                                           \
+            if (direction == BPF_EGRESS) {                                                     \
+                __sync_fetch_and_add(&value->txPackets, 1);                                    \
+                __sync_fetch_and_add(&value->txBytes, skb->len);                               \
+            } else if (direction == BPF_INGRESS) {                                             \
+                __sync_fetch_and_add(&value->rxPackets, 1);                                    \
+                __sync_fetch_and_add(&value->rxBytes, skb->len);                               \
+            }                                                                                  \
+        }                                                                                      \
+    }
+
+DEFINE_UPDATE_STATS(app_uid_stats_map, uint32_t)
+DEFINE_UPDATE_STATS(iface_stats_map, uint32_t)
+DEFINE_UPDATE_STATS(stats_map_A, stats_key)
+DEFINE_UPDATE_STATS(stats_map_B, stats_key)
+
+static inline bool skip_owner_match(struct __sk_buff* skb) {
+    int offset = -1;
+    int ret = 0;
+    if (skb->protocol == htons(ETH_P_IP)) {
+        offset = IP_PROTO_OFF;
+        uint8_t proto, ihl;
+        uint16_t flag;
+        ret = bpf_skb_load_bytes(skb, offset, &proto, 1);
+        if (!ret) {
+            if (proto == IPPROTO_ESP) {
+                return true;
+            } else if (proto == IPPROTO_TCP) {
+                ret = bpf_skb_load_bytes(skb, IPPROTO_IHL_OFF, &ihl, 1);
+                ihl = ihl & 0x0F;
+                ret = bpf_skb_load_bytes(skb, ihl * 4 + TCP_FLAG_OFF, &flag, 1);
+                if (ret == 0 && (flag >> RST_OFFSET & 1)) {
+                    return true;
+                }
+            }
+        }
+    } else if (skb->protocol == htons(ETH_P_IPV6)) {
+        offset = IPV6_PROTO_OFF;
+        uint8_t proto;
+        ret = bpf_skb_load_bytes(skb, offset, &proto, 1);
+        if (!ret) {
+            if (proto == IPPROTO_ESP) {
+                return true;
+            } else if (proto == IPPROTO_TCP) {
+                uint16_t flag;
+                ret = bpf_skb_load_bytes(skb, sizeof(struct ipv6hdr) + TCP_FLAG_OFF, &flag, 1);
+                if (ret == 0 && (flag >> RST_OFFSET & 1)) {
+                    return true;
+                }
+            }
+        }
+    }
+    return false;
+}
+
+static __always_inline BpfConfig getConfig(uint32_t configKey) {
+    uint32_t mapSettingKey = configKey;
+    BpfConfig* config = bpf_configuration_map_lookup_elem(&mapSettingKey);
+    if (!config) {
+        // Couldn't read configuration entry. Assume everything is disabled.
+        return DEFAULT_CONFIG;
+    }
+    return *config;
+}
+
+static inline int bpf_owner_match(struct __sk_buff* skb, uint32_t uid, int direction) {
+    if (skip_owner_match(skb)) return BPF_PASS;
+
+    if ((uid <= MAX_SYSTEM_UID) && (uid >= MIN_SYSTEM_UID)) return BPF_PASS;
+
+    BpfConfig enabledRules = getConfig(UID_RULES_CONFIGURATION_KEY);
+
+    UidOwnerValue* uidEntry = bpf_uid_owner_map_lookup_elem(&uid);
+    uint8_t uidRules = uidEntry ? uidEntry->rule : 0;
+    uint32_t allowed_iif = uidEntry ? uidEntry->iif : 0;
+
+    if (enabledRules) {
+        if ((enabledRules & DOZABLE_MATCH) && !(uidRules & DOZABLE_MATCH)) {
+            return BPF_DROP;
+        }
+        if ((enabledRules & STANDBY_MATCH) && (uidRules & STANDBY_MATCH)) {
+            return BPF_DROP;
+        }
+        if ((enabledRules & POWERSAVE_MATCH) && !(uidRules & POWERSAVE_MATCH)) {
+            return BPF_DROP;
+        }
+    }
+    if (direction == BPF_INGRESS && (uidRules & IIF_MATCH)) {
+        // Drops packets not coming from lo nor the whitelisted interface
+        if (allowed_iif && skb->ifindex != 1 && skb->ifindex != allowed_iif) {
+            return BPF_DROP;
+        }
+    }
+    return BPF_PASS;
+}
+
+static __always_inline inline void update_stats_with_config(struct __sk_buff* skb, int direction,
+                                                            stats_key* key, uint8_t selectedMap) {
+    if (selectedMap == SELECT_MAP_A) {
+        update_stats_map_A(skb, direction, key);
+    } else if (selectedMap == SELECT_MAP_B) {
+        update_stats_map_B(skb, direction, key);
+    }
+}
+
+static __always_inline inline int bpf_traffic_account(struct __sk_buff* skb, int direction) {
+    uint32_t sock_uid = bpf_get_socket_uid(skb);
+    int match = bpf_owner_match(skb, sock_uid, direction);
+    if ((direction == BPF_EGRESS) && (match == BPF_DROP)) {
+        // If an outbound packet is going to be dropped, we do not count that
+        // traffic.
+        return match;
+    }
+
+    uint64_t cookie = bpf_get_socket_cookie(skb);
+    uid_tag* utag = bpf_cookie_tag_map_lookup_elem(&cookie);
+    uint32_t uid, tag;
+    if (utag) {
+        uid = utag->uid;
+        tag = utag->tag;
+    } else {
+        uid = sock_uid;
+        tag = 0;
+    }
+
+    stats_key key = {.uid = uid, .tag = tag, .counterSet = 0, .ifaceIndex = skb->ifindex};
+
+    uint8_t* counterSet = bpf_uid_counterset_map_lookup_elem(&uid);
+    if (counterSet) key.counterSet = (uint32_t)*counterSet;
+
+    uint32_t mapSettingKey = CURRENT_STATS_MAP_CONFIGURATION_KEY;
+    uint8_t* selectedMap = bpf_configuration_map_lookup_elem(&mapSettingKey);
+    if (!selectedMap) {
+        return match;
+    }
+
+    if (key.tag) {
+        update_stats_with_config(skb, direction, &key, *selectedMap);
+        key.tag = 0;
+    }
+
+    update_stats_with_config(skb, direction, &key, *selectedMap);
+    update_app_uid_stats_map(skb, direction, &uid);
+    return match;
+}
 
 SEC("cgroupskb/ingress/stats")
 int bpf_cgroup_ingress(struct __sk_buff* skb) {