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/*
* Network proxy abstraction in PuTTY
*
* A proxy layer, if necessary, wedges itself between the
* network code and the higher level backend.
*
* Supported proxies: HTTP CONNECT, generic telnet, SOCKS 4 & 5
*/
#ifndef PUTTY_PROXY_H
#define PUTTY_PROXY_H
#define PROXY_ERROR_GENERAL 8000
#define PROXY_ERROR_UNEXPECTED 8001
typedef struct ProxySocket ProxySocket;
struct ProxySocket {
const char *error;
Socket *sub_socket;
Plug *plug;
SockAddr *remote_addr;
int remote_port;
bufchain pending_output_data;
bufchain pending_oob_output_data;
bufchain pending_input_data;
bool pending_eof;
#define PROXY_STATE_NEW -1
#define PROXY_STATE_ACTIVE 0
int state; /* proxy states greater than 0 are implementation
* dependent, but represent various stages/states
* of the initialization/setup/negotiation with the
* proxy server.
*/
bool freeze; /* should we freeze the underlying socket when
* we are done with the proxy negotiation? this
* simply caches the value of sk_set_frozen calls.
*/
#define PROXY_CHANGE_NEW -1
#define PROXY_CHANGE_CLOSING 0
#define PROXY_CHANGE_SENT 1
#define PROXY_CHANGE_RECEIVE 2
#define PROXY_CHANGE_ACCEPTING 3
/* something has changed (a call from the sub socket
* layer into our Proxy Plug layer, or we were just
* created, etc), so the proxy layer needs to handle
* this change (the type of which is the second argument)
* and further the proxy negotiation process.
*/
int (*negotiate) (ProxySocket * /* this */, int /* change type */);
/* current arguments of plug handlers
* (for use by proxy's negotiate function)
*/
/* closing */
const char *closing_error_msg;
int closing_error_code;
bool closing_calling_back;
/* receive */
bool receive_urgent;
const char *receive_data;
int receive_len;
/* accepting */
accept_fn_t accepting_constructor;
accept_ctx_t accepting_ctx;
/* configuration, used to look up proxy settings */
Conf *conf;
/* CHAP transient data */
int chap_num_attributes;
int chap_num_attributes_processed;
int chap_current_attribute;
int chap_current_datalen;
Socket sock;
Plug plugimpl;
};
extern void proxy_activate (ProxySocket *);
extern int proxy_http_negotiate (ProxySocket *, int);
extern int proxy_telnet_negotiate (ProxySocket *, int);
extern int proxy_socks4_negotiate (ProxySocket *, int);
extern int proxy_socks5_negotiate (ProxySocket *, int);
/*
* This may be reused by local-command proxies on individual
* platforms.
*/
char *format_telnet_command(SockAddr *addr, int port, Conf *conf);
/*
* These are implemented in cproxy.c or nocproxy.c, depending on
* whether encrypted proxy authentication is available.
*/
extern void proxy_socks5_offerencryptedauth(BinarySink *);
extern int proxy_socks5_handlechap (ProxySocket *);
extern int proxy_socks5_selectchap(ProxySocket *);
#endif
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