feat(p5-socket): --address, -4/-6, --sockopts, server bind options

src/shared/transport_tcp.h

@@ -1,12 +1,14 @@
 #ifndef TRANSPORT_TCP_H
 #define TRANSPORT_TCP_H
 
+#include "config.h"
+#include <netdb.h>
 #include <netinet/in.h>
 #include <stdbool.h>
 #include <sys/types.h>
 
 typedef struct Server {
-  struct sockaddr_in address;
+  struct sockaddr_storage address;
   unsigned int address_length;
   int file_descriptor;
   void* ssl_ctx;
@@ -23,13 +25,35 @@ typedef struct Client {
   void* ssl_ctx;
 } Client;
 
+/* Options controlling the server's listening bind (/--address, -4/-6).  When
+ * bind_address is NULL and family is AF_UNSPEC the existing default is used:
+ * an IPv4 wildcard (INADDR_ANY). */
+typedef struct {
+  const char* bind_address; /* explicit address to bind, or NULL for wildcard */
+  int family;               /* AF_INET / AF_INET6, or AF_UNSPEC to use the default */
+} ServerBindOptions;
+
+/* Options controlling an outgoing client connect (--address, -4/-6,
+ * --sockopts).  All fields are client/connection-level and never cross the
+ * wire config frame. */
+typedef struct {
+  const char* bind_address; /* --address: local source address to bind, or NULL */
+  int family;               /* AF_INET / AF_INET6 / AF_UNSPEC (from -4 / -6) */
+  const SockOptEntry* sockopts; /* --sockopts allowlist entries */
+  int sockopt_count;
+} TcpConnectOptions;
+
+Server* server_create_ex(int port, const ServerBindOptions* bind_opts);
 Server* server_create(int port);
 bool server_listen(Server* server, void (*handler)(int file_descriptor));
 void server_accept_loop(Server* server, void (*child_fn)(int, void*), void* child_ctx,
                         const char* log_fmt);
 void server_delete(Server** server);
 Client* client_create();
+bool client_connect_ex(Client* client, const char* host, int port, const TcpConnectOptions* opts);
 bool client_connect(Client* client, char* host, int port);
+bool tcp_connect_socket_ex(Client* client, const char* host, int port,
+                           const TcpConnectOptions* opts);
 bool tcp_connect_socket(Client* client, char* host, int port);
 void client_disconnect(Client* client);
 void client_delete(Client* client);
@@ -37,4 +61,10 @@ void tcp_set_timeouts(int timeout_sec, int contimeout_sec);
 int tcp_get_contimeout_sec(void);
 int tcp_get_timeout_sec(void);
 
+/* Resolve -4/-6 flags to a getaddrinfo ai_family value.  ipv4 wins over ipv6;
+ * when neither is set it returns AF_UNSPEC.  0 means "no preference" and is
+ * therefore never returned; callers that need the "no explicit flag" sentinel
+ * compare the flags directly. */
+int tcp_connect_family(bool ipv4, bool ipv6);
+
 #endif