git.distorted.org.uk Git - u/mdw/putty/blob - proxy.h

   1 /*
   2  * Network proxy abstraction in PuTTY
   3  *
   4  * A proxy layer, if necessary, wedges itself between the
   5  * network code and the higher level backend.
   6  *
   7  * Supported proxies: HTTP CONNECT, generic telnet
   8  * In progress: SOCKS
   9  */
  10
  11 #ifndef PUTTY_PROXY_H
  12 #define PUTTY_PROXY_H
  13
  14 #define PROXY_ERROR_GENERAL 8000
  15 #define PROXY_ERROR_UNEXPECTED 8001
  16
  17 typedef struct Socket_proxy_tag * Proxy_Socket;
  18
  19 struct Socket_proxy_tag {
  20     struct socket_function_table *fn;
  21     /* the above variable absolutely *must* be the first in this structure */
  22
  23     char * error;
  24
  25     Socket sub_socket;
  26     Plug plug;
  27     SockAddr remote_addr;
  28     int remote_port;
  29
  30     bufchain pending_output_data;
  31     bufchain pending_oob_output_data;
  32     int pending_flush;
  33     bufchain pending_input_data;
  34
  35 #define PROXY_STATE_NEW    -1
  36 #define PROXY_STATE_ACTIVE  0
  37
  38     int state; /* proxy states greater than 0 are implementation
  39                 * dependent, but represent various stages/states
  40                 * of the initialization/setup/negotiation with the
  41                 * proxy server.
  42                 */
  43     int freeze; /* should we freeze the underlying socket when
  44                  * we are done with the proxy negotiation? this
  45                  * simply caches the value of sk_set_frozen calls.
  46                  */
  47
  48 #define PROXY_CHANGE_NEW      -1
  49 #define PROXY_CHANGE_CLOSING   0
  50 #define PROXY_CHANGE_SENT      1
  51 #define PROXY_CHANGE_RECEIVE   2
  52 #define PROXY_CHANGE_ACCEPTING 3
  53
  54     /* something has changed (a call from the sub socket
  55      * layer into our Proxy Plug layer, or we were just
  56      * created, etc), so the proxy layer needs to handle
  57      * this change (the type of which is the second argument)
  58      * and further the proxy negotiation process.
  59      */
  60
  61     int (*negotiate) (Proxy_Socket /* this */, int /* change type */);
  62
  63     /* current arguments of plug handlers
  64      * (for use by proxy's negotiate function)
  65      */
  66
  67     /* closing */
  68     char *closing_error_msg;
  69     int closing_error_code;
  70     int closing_calling_back;
  71
  72     /* receive */
  73     int receive_urgent;
  74     char *receive_data;
  75     int receive_len;
  76
  77     /* sent */
  78     int sent_bufsize;
  79
  80     /* accepting */
  81     void *accepting_sock;
  82
  83     /* spin locks, for the critical switch from negotiating
  84      * to active state. we have to dump all of our pending
  85      * buffers without new events (read, writes, etc) corrupting
  86      * things. we should not have built up a large amount of
  87      * pending data during negotiation, so hopefully this will
  88      * not have a large effect on performance.
  89      */
  90
  91     char lock_close;
  92     char lock_write;
  93     char lock_write_oob;
  94     char lock_receive;
  95     char lock_flush;
  96     char lock_closing;
  97     char lock_sent;
  98     char lock_accepting;
  99     char lock_freeze;
 100
 101 };
 102
 103 typedef struct Plug_proxy_tag * Proxy_Plug;
 104
 105 struct Plug_proxy_tag {
 106     struct plug_function_table *fn;
 107     /* the above variable absolutely *must* be the first in this structure */
 108
 109     Proxy_Socket proxy_socket;
 110
 111 };
 112
 113 extern void proxy_activate (Proxy_Socket);
 114
 115 extern int proxy_http_negotiate (Proxy_Socket, int);
 116 extern int proxy_telnet_negotiate (Proxy_Socket, int);
 117 extern int proxy_socks_negotiate (Proxy_Socket, int);
 118
 119 #endif