| 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 | |
| 13 | #ifndef PUTTY_NETWORK_H |
| 14 | #define PUTTY_NETWORK_H |
| 15 | |
| 16 | typedef struct Socket_tag *Socket; |
| 17 | typedef struct SockAddr_tag *SockAddr; |
| 18 | |
| 19 | /* |
| 20 | * This is the function a client must register with each socket, to |
| 21 | * receive data coming in on that socket. The parameter `urgent' |
| 22 | * decides the meaning of `data' and `len': |
| 23 | * |
| 24 | * - urgent==0. `data' points to `len' bytes of perfectly ordinary |
| 25 | * data. |
| 26 | * |
| 27 | * - urgent==1. `data' points to `len' bytes of data, which were |
| 28 | * read from before an Urgent pointer. |
| 29 | * |
| 30 | * - urgent==2. `data' points to `len' bytes of data, the first of |
| 31 | * which was the one at the Urgent mark. |
| 32 | * |
| 33 | * - urgent==3. An error has occurred on the socket. `data' points |
| 34 | * to an error string, and `len' points to an error code. |
| 35 | */ |
| 36 | typedef int (*sk_receiver_t)(Socket s, int urgent, char *data, int len); |
| 37 | |
| 38 | void sk_init(void); /* called once at program startup */ |
| 39 | |
| 40 | SockAddr sk_namelookup(char *host, char **canonicalname); |
| 41 | void sk_addr_free(SockAddr addr); |
| 42 | |
| 43 | Socket sk_new(SockAddr addr, int port, int privport, int oobinline, |
| 44 | sk_receiver_t receiver); |
| 45 | void sk_close(Socket s); |
| 46 | void sk_write(Socket s, char *buf, int len); |
| 47 | void sk_write_oob(Socket s, char *buf, int len); |
| 48 | |
| 49 | /* |
| 50 | * Each socket abstraction contains a `void *' private field in |
| 51 | * which the client can keep state. |
| 52 | */ |
| 53 | void sk_set_private_ptr(Socket s, void *ptr); |
| 54 | void *sk_get_private_ptr(Socket s); |
| 55 | |
| 56 | /* |
| 57 | * Special error values are returned from sk_namelookup and sk_new |
| 58 | * if there's a problem. These functions extract an error message, |
| 59 | * or return NULL if there's no problem. |
| 60 | */ |
| 61 | char *sk_addr_error(SockAddr addr); |
| 62 | char *sk_socket_error(Socket addr); |
| 63 | |
| 64 | #endif |