putty/network.h

64 строки
2.1 KiB
C

/*
* 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 function to be called when data comes in on
* any given one, 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
typedef struct Socket_tag *Socket;
typedef struct SockAddr_tag *SockAddr;
/*
* This is the function a client must register with each socket, to
* receive data coming in on that socket. The parameter `urgent'
* decides the meaning of `data' and `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.
*
* - urgent==3. An error has occurred on the socket. `data' points
* to an error string, and `len' points to an error code.
*/
typedef int (*sk_receiver_t)(Socket s, int urgent, char *data, int len);
void sk_init(void); /* called once at program startup */
SockAddr sk_namelookup(char *host, char **canonicalname);
void sk_addr_free(SockAddr addr);
Socket sk_new(SockAddr addr, int port, int privport, sk_receiver_t receiver);
void sk_close(Socket s);
void sk_write(Socket s, char *buf, int len);
void sk_write_oob(Socket s, char *buf, int len);
/*
* Each socket abstraction contains a `void *' private field in
* which the client can keep state.
*/
void sk_set_private_ptr(Socket s, void *ptr);
void *sk_get_private_ptr(Socket 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.
*/
char *sk_addr_error(SockAddr addr);
char *sk_socket_error(Socket addr);
#endif