mirror of
https://git.tartarus.org/simon/putty.git
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988c1974ea
advantages: - protocol modules can call sk_write() without having to worry about writes blocking, because blocking writes are handled in the abstraction layer and retried later. - `Lost connection while sending' is a thing of the past. - <winsock.h> is no longer needed in most modules, because "putty.h" doesn't have to declare `SOCKET' variables any more, only the abstracted `Socket' type. - select()-equivalent between multiple sockets will now be handled sensibly, which opens the way for things like SSH port forwarding. [originally from svn r745]
45 lines
1.6 KiB
C
45 lines
1.6 KiB
C
/*
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* Networking abstraction in PuTTY.
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*
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* The way this works is: a back end can choose to open any number
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* of sockets - including zero, which might be necessary in some.
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* It can register a function to be called when data comes in on
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* any given one, and it can call the networking abstraction to
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* send data without having to worry about blocking. The stuff
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* behind the abstraction takes care of selects and nonblocking
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* writes and all that sort of painful gubbins.
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*
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* If urgent data comes in on a socket, the back end will read and
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* discard up to the urgent pointer, then read the urgent byte and
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* send _that_ to the receiver function with `urgent' set.
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*/
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typedef struct Socket_tag *Socket;
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typedef struct SockAddr_tag *SockAddr;
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typedef int (*sk_receiver_t)(Socket s, int urgent, char *data, int len);
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void sk_init(void); /* called once at program startup */
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SockAddr sk_namelookup(char *host, char **canonicalname);
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void sk_addr_free(SockAddr addr);
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Socket sk_new(SockAddr addr, int port, sk_receiver_t receiver);
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void sk_close(Socket s);
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void sk_write(Socket s, char *buf, int len);
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void sk_write_oob(Socket s, char *buf, int len);
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/*
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* Each socket abstraction contains a `void *' private field in
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* which the client can keep state.
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*/
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void sk_set_private_ptr(Socket s, void *ptr);
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void *sk_get_private_ptr(Socket s);
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/*
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* Special error values are returned from sk_namelookup and sk_new
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* if there's a problem. These functions extract an error message,
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* or return NULL if there's no problem.
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*/
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char *sk_addr_error(SockAddr addr);
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char *sk_socket_error(Socket addr);
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