| 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 | #ifndef PUTTY_NETWORK_H |
| 18 | #define PUTTY_NETWORK_H |
| 19 | |
| 20 | typedef struct Socket_tag *Socket; |
| 21 | typedef struct SockAddr_tag *SockAddr; |
| 22 | typedef int (*sk_receiver_t)(Socket s, int urgent, char *data, int len); |
| 23 | |
| 24 | void sk_init(void); /* called once at program startup */ |
| 25 | |
| 26 | SockAddr sk_namelookup(char *host, char **canonicalname); |
| 27 | void sk_addr_free(SockAddr addr); |
| 28 | |
| 29 | Socket sk_new(SockAddr addr, int port, sk_receiver_t receiver); |
| 30 | void sk_close(Socket s); |
| 31 | void sk_write(Socket s, char *buf, int len); |
| 32 | void sk_write_oob(Socket s, char *buf, int len); |
| 33 | |
| 34 | /* |
| 35 | * Each socket abstraction contains a `void *' private field in |
| 36 | * which the client can keep state. |
| 37 | */ |
| 38 | void sk_set_private_ptr(Socket s, void *ptr); |
| 39 | void *sk_get_private_ptr(Socket s); |
| 40 | |
| 41 | /* |
| 42 | * Special error values are returned from sk_namelookup and sk_new |
| 43 | * if there's a problem. These functions extract an error message, |
| 44 | * or return NULL if there's no problem. |
| 45 | */ |
| 46 | char *sk_addr_error(SockAddr addr); |
| 47 | char *sk_socket_error(Socket addr); |
| 48 | |
| 49 | #endif |