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mirror of https://git.tartarus.org/simon/putty.git synced 2025-03-14 02:53:51 -05:00
putty-source/proxy.h
Simon Tatham d42f1fe96d Remove 'calling_back' parameter from plug_closing.
It was totally unused. No implementation of the 'closing' method in a
Plug vtable was checking it for any reason at all, except for
ProxySocket which captured it from its client in order to pass on to
its server (which, perhaps after further iterations of ProxySocket,
would have ended up ignoring it similarly). And every caller of
plug_closing set it to 0 (aka false), except for the one in sshproxy.c
which passed true (but it would have made no difference to anyone).

The comment in network.h refers to a FIXME comment which was in
try_send() when that code was written (see winnet.c in commit
7b0e08270058390). That FIXME is long gone, replaced by a use of a
toplevel callback. So I think the aim must have been to avoid
re-entrancy when sk_write called try_send which encountered a socket
error and called back to plug_closing - but that's long since fixed by
other means now.
2021-10-24 09:58:59 +01:00

111 lines
3.0 KiB
C

/*
* 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;
/* 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