2f75bae1 |
1 | /* |
2 | * Networking abstraction in PuTTY. |
3 | * |
4 | * The way this works is: a back end can choose to open any number |
5 | * of sockets - including zero, which might be necessary in some. |
6 | * It can register a function to be called when data comes in on |
7 | * any given one, and it can call the networking abstraction to |
8 | * send data without having to worry about blocking. The stuff |
9 | * behind the abstraction takes care of selects and nonblocking |
10 | * writes and all that sort of painful gubbins. |
11 | * |
12 | * If urgent data comes in on a socket, the back end will read and |
13 | * discard up to the urgent pointer, then read the urgent byte and |
14 | * send _that_ to the receiver function with `urgent' set. |
15 | */ |
16 | |
17 | typedef struct Socket_tag *Socket; |
18 | typedef struct SockAddr_tag *SockAddr; |
19 | typedef int (*sk_receiver_t)(Socket s, int urgent, char *data, int len); |
20 | |
21 | void sk_init(void); /* called once at program startup */ |
22 | |
23 | SockAddr sk_namelookup(char *host, char **canonicalname); |
24 | void sk_addr_free(SockAddr addr); |
25 | |
26 | Socket sk_new(SockAddr addr, int port, sk_receiver_t receiver); |
27 | void sk_close(Socket s); |
28 | void sk_write(Socket s, char *buf, int len); |
29 | void sk_write_oob(Socket s, char *buf, int len); |
30 | |
31 | /* |
32 | * Each socket abstraction contains a `void *' private field in |
33 | * which the client can keep state. |
34 | */ |
35 | void sk_set_private_ptr(Socket s, void *ptr); |
36 | void *sk_get_private_ptr(Socket s); |
37 | |
38 | /* |
39 | * Special error values are returned from sk_namelookup and sk_new |
40 | * if there's a problem. These functions extract an error message, |
41 | * or return NULL if there's no problem. |
42 | */ |
43 | char *sk_addr_error(SockAddr addr); |
44 | char *sk_socket_error(Socket addr); |