Reintegrate tools from trunk

1 files changed, 247 insertions, 0 deletions

diff --git a/tools/plink/network.h b/tools/plink/network.h
new file mode 100644
index 000000000..b1b559047
--- /dev/null
+++ b/tools/plink/network.h
@@ -0,0 +1,247 @@
+/*

+ * Networking abstraction in PuTTY.

+ *

+ * The way this works is: a back end can choose to open any number

+ * of sockets - including zero, which might be necessary in some.

+ * It can register a bunch of callbacks (most notably for when 

+ * data is received) for each socket, and it can call the networking

+ * abstraction to send data without having to worry about blocking.

+ * The stuff behind the abstraction takes care of selects and

+ * nonblocking writes and all that sort of painful gubbins.

+ */

+

+#ifndef PUTTY_NETWORK_H

+#define PUTTY_NETWORK_H

+

+#ifndef DONE_TYPEDEFS

+#define DONE_TYPEDEFS

+typedef struct config_tag Config;

+typedef struct backend_tag Backend;

+typedef struct terminal_tag Terminal;

+#endif

+

+typedef struct SockAddr_tag *SockAddr;

+/* pay attention to levels of indirection */

+typedef struct socket_function_table **Socket;

+typedef struct plug_function_table **Plug;

+

+#ifndef OSSOCKET_DEFINED

+typedef void *OSSocket;

+#endif

+

+struct socket_function_table {

+    Plug(*plug) (Socket s, Plug p);

+    /* use a different plug (return the old one) */

+    /* if p is NULL, it doesn't change the plug */

+    /* but it does return the one it's using */

+    void (*close) (Socket s);

+    int (*write) (Socket s, const char *data, int len);

+    int (*write_oob) (Socket s, const 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 */

+    const char *(*socket_error) (Socket s);

+};

+

+struct plug_function_table {

+    void (*log)(Plug p, int type, SockAddr addr, int port,

+		const char *error_msg, int error_code);

+    /*

+     * Passes the client progress reports on the process of setting

+     * up the connection.

+     * 

+     * 	- type==0 means we are about to try to connect to address

+     * 	  `addr' (error_msg and error_code are ignored)

+     * 	- type==1 means we have failed to connect to address `addr'

+     * 	  (error_msg and error_code are supplied). This is not a

+     * 	  fatal error - we may well have other candidate addresses

+     * 	  to fall back to. When it _is_ fatal, the closing()

+     * 	  function will be called.

+     */

+    int (*closing)

+     (Plug p, const char *error_msg, int error_code, int calling_back);

+    /* error_msg is NULL iff it is not an error (ie it closed normally) */

+    /* calling_back != 0 iff there is a Plug function */

+    /* currently running (would cure the fixme in try_send()) */

+    int (*receive) (Plug p, int urgent, char *data, int len);

+    /*

+     *  - urgent==0. `data' points to `len' bytes of perfectly

+     *    ordinary data.

+     * 

+     *  - urgent==1. `data' points to `len' bytes of data,

+     *    which were read from before an Urgent pointer.

+     * 

+     *  - 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, OSSocket sock);

+    /*

+     * returns 0 if the host at address addr is a valid host for connecting or error

+     */

+};

+

+/* proxy indirection layer */

+/* NB, control of 'addr' is passed via new_connection, which takes

+ * responsibility for freeing it */

+Socket new_connection(SockAddr addr, char *hostname,

+		      int port, int privport,

+		      int oobinline, int nodelay, int keepalive,

+		      Plug plug, const Config *cfg);

+Socket new_listener(char *srcaddr, int port, Plug plug, int local_host_only,

+		    const Config *cfg, int addressfamily);

+SockAddr name_lookup(char *host, int port, char **canonicalname,

+		     const Config *cfg, int addressfamily);

+

+/* platform-dependent callback from new_connection() */

+/* (same caveat about addr as new_connection()) */

+Socket platform_new_connection(SockAddr addr, char *hostname,

+			       int port, int privport,

+			       int oobinline, int nodelay, int keepalive,

+			       Plug plug, const Config *cfg);

+

+/* socket functions */

+

+void sk_init(void);		       /* called once at program startup */

+void sk_cleanup(void);		       /* called just before program exit */

+

+SockAddr sk_namelookup(const char *host, char **canonicalname, int address_family);

+SockAddr sk_nonamelookup(const 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);

+int sk_addrtype(SockAddr addr);

+void sk_addrcopy(SockAddr addr, char *buf);

+void sk_addr_free(SockAddr addr);

+/* sk_addr_dup generates another SockAddr which contains the same data

+ * as the original one and can be freed independently. May not actually

+ * physically _duplicate_ it: incrementing a reference count so that

+ * one more free is required before it disappears is an acceptable

+ * implementation. */

+SockAddr sk_addr_dup(SockAddr addr);

+

+/* NB, control of 'addr' is passed via sk_new, which takes responsibility

+ * for freeing it, as for new_connection() */

+Socket sk_new(SockAddr addr, int port, int privport, int oobinline,

+	      int nodelay, int keepalive, Plug p);

+

+Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only, int address_family);

+

+Socket sk_register(OSSocket sock, Plug plug);

+

+#define sk_plug(s,p) (((*s)->plug) (s, p))

+#define sk_close(s) (((*s)->close) (s))

+#define sk_write(s,buf,len) (((*s)->write) (s, buf, len))

+#define sk_write_oob(s,buf,len) (((*s)->write_oob) (s, buf, len))

+#define sk_flush(s) (((*s)->flush) (s))

+

+#ifdef DEFINE_PLUG_METHOD_MACROS

+#define plug_log(p,type,addr,port,msg,code) (((*p)->log) (p, type, addr, port, msg, code))

+#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

+

+/*

+ * Each socket abstraction contains a `void *' private field in

+ * which the client can keep state.

+ *

+ * 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.

+ */

+#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

+ * if there's a problem. These functions extract an error message,

+ * or return NULL if there's no problem.

+ */

+const 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);

+

+/*

+ * Look up the local hostname; return value needs freeing.

+ * May return NULL.

+ */

+char *get_hostname(void);

+

+/********** SSL stuff **********/

+

+/*

+ * This section is subject to change, but you get the general idea

+ * of what it will eventually look like.

+ */

+

+typedef struct certificate *Certificate;

+typedef struct our_certificate *Our_Certificate;

+    /* to be defined somewhere else, somehow */

+

+typedef struct ssl_client_socket_function_table **SSL_Client_Socket;

+typedef struct ssl_client_plug_function_table **SSL_Client_Plug;

+

+struct ssl_client_socket_function_table {

+    struct socket_function_table base;

+    void (*renegotiate) (SSL_Client_Socket s);

+    /* renegotiate the cipher spec */

+};

+

+struct ssl_client_plug_function_table {

+    struct plug_function_table base;

+    int (*refuse_cert) (SSL_Client_Plug p, Certificate cert[]);

+    /* do we accept this certificate chain?  If not, why not? */

+    /* cert[0] is the server's certificate, cert[] is NULL-terminated */

+    /* the last certificate may or may not be the root certificate */

+     Our_Certificate(*client_cert) (SSL_Client_Plug p);

+    /* the server wants us to identify ourselves */

+    /* may return NULL if we want anonymity */

+};

+

+SSL_Client_Socket sk_ssl_client_over(Socket s,	/* pre-existing (tcp) connection */

+				     SSL_Client_Plug p);

+

+#define sk_renegotiate(s) (((*s)->renegotiate) (s))

+

+#endif