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, SOCKS 4 & 5
   8  */
   9
  10 #ifndef PUTTY_PROXY_H
  11 #define PUTTY_PROXY_H
  12
  13 #define PROXY_ERROR_GENERAL 8000
  14 #define PROXY_ERROR_UNEXPECTED 8001
  15
  16 typedef struct Socket_proxy_tag * Proxy_Socket;
  17
  18 struct Socket_proxy_tag {
  19     const struct socket_function_table *fn;
  20     /* the above variable absolutely *must* be the first in this structure */
  21
  22     char * error;
  23
  24     Socket sub_socket;
  25     Plug plug;
  26     SockAddr remote_addr;
  27     int remote_port;
  28
  29     bufchain pending_output_data;
  30     bufchain pending_oob_output_data;
  31     int pending_flush;
  32     bufchain pending_input_data;
  33     int pending_eof;
  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     const 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     OSSocket accepting_sock;
  82
  83     /* configuration, used to look up proxy settings */
  84     Conf *conf;
  85
  86     /* CHAP transient data */
  87     int chap_num_attributes;
  88     int chap_num_attributes_processed;
  89     int chap_current_attribute;
  90     int chap_current_datalen;
  91 };
  92
  93 typedef struct Plug_proxy_tag * Proxy_Plug;
  94
  95 struct Plug_proxy_tag {
  96     const struct plug_function_table *fn;
  97     /* the above variable absolutely *must* be the first in this structure */
  98
  99     Proxy_Socket proxy_socket;
 100
 101 };
 102
 103 extern void proxy_activate (Proxy_Socket);
 104
 105 extern int proxy_http_negotiate (Proxy_Socket, int);
 106 extern int proxy_telnet_negotiate (Proxy_Socket, int);
 107 extern int proxy_socks4_negotiate (Proxy_Socket, int);
 108 extern int proxy_socks5_negotiate (Proxy_Socket, int);
 109
 110 /*
 111  * This may be reused by local-command proxies on individual
 112  * platforms.
 113  */
 114 char *format_telnet_command(SockAddr addr, int port, Conf *conf);
 115
 116 /*
 117  * These are implemented in cproxy.c or nocproxy.c, depending on
 118  * whether encrypted proxy authentication is available.
 119  */
 120 extern void proxy_socks5_offerencryptedauth(char *command, int *len);
 121 extern int proxy_socks5_handlechap (Proxy_Socket p);
 122 extern int proxy_socks5_selectchap(Proxy_Socket p);
 123
 124 #endif