Support for doing DNS at the proxy end. I've invented a new type of

[u/mdw/putty] / network.h

diff --git a/network.h b/network.h
index e4bb578..e9ad518 100644 (file)
--- a/network.h
+++ b/network.h
@@ -24,9 +24,12 @@ struct socket_function_table {
     /* if p is NULL, it doesn't change the plug */
     /* but it does return the one it's using */
     void (*close) (Socket s);
-    void (*write) (Socket s, char *data, int len);
-    void (*write_oob) (Socket s, char *data, int len);
+    int (*write) (Socket s, char *data, int len);
+    int (*write_oob) (Socket s, char *data, int len);
     void (*flush) (Socket s);
+    void (*set_private_ptr) (Socket s, void *ptr);
+    void *(*get_private_ptr) (Socket s);
+    void (*set_frozen) (Socket s, int is_frozen);
     /* ignored by tcp, but vital for ssl */
     char *(*socket_error) (Socket s);
 };
@@ -48,16 +51,46 @@ struct plug_function_table {
      *  - urgent==2. `data' points to `len' bytes of data,
      *    the first of which was the one at the Urgent mark.
      */
+    void (*sent) (Plug p, int bufsize);
+    /*
+     * The `sent' function is called when the pending send backlog
+     * on a socket is cleared or partially cleared. The new backlog
+     * size is passed in the `bufsize' parameter.
+     */
+    int (*accepting)(Plug p, void *sock);
+    /*
+     * returns 0 if the host at address addr is a valid host for connecting or error
+     */
 };
 
+/* proxy indirection layer */
+Socket new_connection(SockAddr addr, char *hostname,
+                     int port, int privport,
+                     int oobinline, int nodelay, Plug plug);
+Socket new_listener(char *srcaddr, int port, Plug plug, int local_host_only);
+SockAddr name_lookup(char *host, int port, char **canonicalname);
+
+/* socket functions */
 
 void sk_init(void);                   /* called once at program startup */
+void sk_cleanup(void);                /* called just before program exit */
 
 SockAddr sk_namelookup(char *host, char **canonicalname);
+SockAddr sk_nonamelookup(char *host);
+void sk_getaddr(SockAddr addr, char *buf, int buflen);
+int sk_hostname_is_local(char *name);
+int sk_address_is_local(SockAddr addr);
+enum { ADDRTYPE_IPV4, ADDRTYPE_IPV6, ADDRTYPE_NAME };
+int sk_addrtype(SockAddr addr);
+void sk_addrcopy(SockAddr addr, char *buf);
 void sk_addr_free(SockAddr addr);
 
 Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
-             Plug p);
+             int nodelay, Plug p);
+
+Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only);
+
+Socket sk_register(void *sock, Plug plug);
 
 #define sk_plug(s,p) (((*s)->plug) (s, p))
 #define sk_close(s) (((*s)->close) (s))
@@ -68,6 +101,8 @@ Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
 #ifdef DEFINE_PLUG_METHOD_MACROS
 #define plug_closing(p,msg,code,callback) (((*p)->closing) (p, msg, code, callback))
 #define plug_receive(p,urgent,buf,len) (((*p)->receive) (p, urgent, buf, len))
+#define plug_sent(p,bufsize) (((*p)->sent) (p, bufsize))
+#define plug_accepting(p, sock) (((*p)->accepting)(p, sock))
 #endif
 
 /*
@@ -77,8 +112,8 @@ Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
  * This is perhaps unnecessary now that we have the notion of a plug,
  * but there is some existing code that uses it, so it stays.
  */
-void sk_set_private_ptr(Socket s, void *ptr);
-void *sk_get_private_ptr(Socket s);
+#define sk_set_private_ptr(s, ptr) (((*s)->set_private_ptr) (s, ptr))
+#define sk_get_private_ptr(s) (((*s)->get_private_ptr) (s))
 
 /*
  * Special error values are returned from sk_namelookup and sk_new
@@ -88,6 +123,39 @@ void *sk_get_private_ptr(Socket s);
 char *sk_addr_error(SockAddr addr);
 #define sk_socket_error(s) (((*s)->socket_error) (s))
 
+/*
+ * Set the `frozen' flag on a socket. A frozen socket is one in
+ * which all READABLE notifications are ignored, so that data is
+ * not accepted from the peer until the socket is unfrozen. This
+ * exists for two purposes:
+ * 
+ *  - Port forwarding: when a local listening port receives a
+ *    connection, we do not want to receive data from the new
+ *    socket until we have somewhere to send it. Hence, we freeze
+ *    the socket until its associated SSH channel is ready; then we
+ *    unfreeze it and pending data is delivered.
+ * 
+ *  - Socket buffering: if an SSH channel (or the whole connection)
+ *    backs up or presents a zero window, we must freeze the
+ *    associated local socket in order to avoid unbounded buffer
+ *    growth.
+ */
+#define sk_set_frozen(s, is_frozen) (((*s)->set_frozen) (s, is_frozen))
+
+/*
+ * Call this after an operation that might have tried to send on a
+ * socket, to clean up any pending network errors.
+ */
+void net_pending_errors(void);
+
+/*
+ * Simple wrapper on getservbyname(), needed by ssh.c. Returns the
+ * port number, in host byte order (suitable for printf and so on).
+ * Returns 0 on failure. Any platform not supporting getservbyname
+ * can just return 0 - this function is not required to handle
+ * numeric port specifications.
+ */
+int net_service_lookup(char *service);
 
 /********** SSL stuff **********/
 
@@ -96,7 +164,6 @@ char *sk_addr_error(SockAddr addr);
  * of what it will eventually look like.
  */
 
-
 typedef struct certificate *Certificate;
 typedef struct our_certificate *Our_Certificate;
     /* to be defined somewhere else, somehow */