add IP stack simulator

2022-03-07 19:45:18 -08:00
parent b2437b085c
commit 951b6085ab
19 changed files with 1745 additions and 96 deletions
@@ -0,0 +1,144 @@
+#include <stdint.h>
+#include <netinet/in.h>
+
+#include <deque>
+#include <string>
+#include <phosg/Process.hh>
+#include <phosg/Filesystem.hh>
+#include <event-async/Task.hh>
+#include <event-async/Base.hh>
+
+#include "IPFrameInfo.hh"
+#include "Server.hh"
+#include "ProxyServer.hh"
+#include "ServerState.hh"
+
+
+
+class IPStackSimulator {
+public:
+  IPStackSimulator(
+      std::shared_ptr<struct event_base> base,
+      std::shared_ptr<Server> game_server,
+      std::shared_ptr<ProxyServer> proxy_server,
+      std::shared_ptr<ServerState> state);
+  ~IPStackSimulator();
+
+  void listen(const std::string& socket_path);
+  void listen(const std::string& addr, int port);
+  void listen(int port);
+  void add_socket(int fd);
+
+  static uint32_t connect_address_for_remote_address(uint32_t remote_addr);
+
+private:
+  std::shared_ptr<struct event_base> base;
+  std::shared_ptr<Server> game_server;
+  std::shared_ptr<ProxyServer> proxy_server;
+  std::shared_ptr<ServerState> state;
+
+  using unique_listener = std::unique_ptr<struct evconnlistener, void(*)(struct evconnlistener*)>;
+  using unique_bufferevent = std::unique_ptr<struct bufferevent, void(*)(struct bufferevent*)>;
+  using unique_evbuffer = std::unique_ptr<struct evbuffer, void(*)(struct evbuffer*)>;
+  using unique_event = std::unique_ptr<struct event, void(*)(struct event*)>;
+
+  struct IPClient {
+    IPStackSimulator* sim;
+
+    unique_bufferevent bev;
+    uint8_t mac_addr[6];
+    uint32_t ipv4_addr;
+
+    struct TCPConnection {
+      std::weak_ptr<IPClient> client;
+
+      // The PSO protocol begins with the server sending a command, but we
+      // shouldn't send a PSH immediately after the SYN+ACK, so the connection
+      // isn't handed to the Server object until after the 3-way handshake
+      // (receive SYN, send SYN+ACK, receive ACK). This means server_bev is null
+      // during the first part of the connection phase.
+      unique_bufferevent server_bev;
+      // TODO: Get rid of pending_data and just use server_bev's input buffer in
+      // its place
+      unique_evbuffer pending_data;
+      unique_event resend_push_event;
+
+      bool awaiting_first_ack;
+
+      uint32_t server_addr;
+      uint16_t server_port;
+      uint16_t client_port;
+      uint32_t next_client_seq;
+      uint32_t acked_server_seq;
+      size_t resend_push_usecs;
+      size_t max_frame_size;
+      size_t bytes_received;
+      size_t bytes_sent;
+
+      TCPConnection();
+    };
+    std::unordered_map<uint64_t, TCPConnection> tcp_connections;
+
+    IPClient(struct bufferevent* bev);
+  };
+
+  std::unordered_set<unique_listener> listeners;
+  std::unordered_map<struct bufferevent*, std::shared_ptr<IPClient>> bev_to_client;
+
+  uint8_t host_mac_address_bytes[6];
+  uint8_t broadcast_mac_address_bytes[6];
+
+  FILE* pcap_text_log_file;
+
+  static uint64_t tcp_conn_key_for_connection(
+      const IPClient::TCPConnection& conn);
+  static uint64_t tcp_conn_key_for_client_frame(
+      const IPv4Header& ipv4, const TCPHeader& tcp);
+  static uint64_t tcp_conn_key_for_client_frame(const FrameInfo& fi);
+
+  static std::string str_for_ipv4_netloc(uint32_t addr, uint16_t port);
+  static std::string str_for_tcp_connection(std::shared_ptr<const IPClient> c,
+      const IPClient::TCPConnection& conn);
+
+  static void dispatch_on_listen_accept(struct evconnlistener* listener,
+      evutil_socket_t fd, struct sockaddr *address, int socklen, void* ctx);
+  void on_listen_accept(struct evconnlistener* listener, evutil_socket_t fd,
+      struct sockaddr *address, int socklen);
+  static void dispatch_on_listen_error(struct evconnlistener* listener, void* ctx);
+  void on_listen_error(struct evconnlistener* listener);
+
+  static void dispatch_on_client_input(struct bufferevent* bev, void* ctx);
+  void on_client_input(struct bufferevent* bev);
+  static void dispatch_on_client_error(struct bufferevent* bev, short events,
+      void* ctx);
+  void on_client_error(struct bufferevent* bev, short events);
+
+  void on_client_frame(std::shared_ptr<IPClient> c, const std::string& frame);
+  void on_client_arp_frame(std::shared_ptr<IPClient> c, const FrameInfo& fi);
+  void on_client_udp_frame(std::shared_ptr<IPClient> c, const FrameInfo& fi);
+  void on_client_tcp_frame(std::shared_ptr<IPClient> c, const FrameInfo& fi);
+
+  static void dispatch_on_resend_push(evutil_socket_t fd, short events,
+      void* ctx);
+  void on_resend_push(std::shared_ptr<IPClient> c, IPClient::TCPConnection& conn);
+
+  static void dispatch_on_server_input(struct bufferevent* bev, void* ctx);
+  void on_server_input(std::shared_ptr<IPClient> c, IPClient::TCPConnection& conn);
+  static void dispatch_on_server_error(struct bufferevent* bev, short events,
+      void* ctx);
+  void on_server_error(std::shared_ptr<IPClient> c, IPClient::TCPConnection& conn, short events);
+
+  void send_pending_push_frame(
+      std::shared_ptr<IPClient> c, IPClient::TCPConnection& conn);
+  void send_tcp_frame(
+      std::shared_ptr<IPClient> c,
+      IPClient::TCPConnection& conn,
+      uint16_t flags = 0,
+      struct evbuffer* src_buf = nullptr,
+      size_t src_bytes = 0);
+
+  void open_server_connection(
+      std::shared_ptr<IPClient> c, IPClient::TCPConnection& conn);
+
+  void log_frame(const std::string& data) const;
+};