Docs for socket BIO.

doc/crypto/BIO_s_socket.pod

+=pod
+
+=head1 NAME
+
+	BIO_s_socket - socket BIO
+
+=head1 SYNOPSIS
+
+ #include <openssl/bio.h>
+
+ BIO_METHOD *	BIO_s_socket(void);
+
+ #define BIO_set_fd(b,fd,c)	BIO_int_ctrl(b,BIO_C_SET_FD,c,fd)
+ #define BIO_get_fd(b,c)	BIO_ctrl(b,BIO_C_GET_FD,0,(char *)c)
+
+ BIO *BIO_new_socket(int sock, int close_flag);
+
+=head1 DESCRIPTION
+
+BIO_f_socket() returns the socket BIO method. This is a wrapper
+round the platform's socket routines.
+
+BIO_read() and BIO_write() read or write the underlying socket.
+BIO_puts() is supported but BIO_gets() is not.
+
+If the close flag is set then the socket is shut down and closed
+when the BIO is freed.
+
+BIO_set_fd() sets the socket of BIO B<b> to B<fd> and the close
+flag to B<c>.
+
+BIO_get_fd() places the socket in B<c> if it is not NULL, it also
+returns the socket . If B<c> is not NULL it should be of type (int *).
+
+BIO_new_socket() returns a socket BIO using B<sock> and B<close_flag>.
+
+=head1 NOTES
+
+Socket BIOs also support any relevant functionality of file descriptor
+BIOs.
+
+The reason for having separate file descriptor and socket BIOs is that on some
+platforms sockets are not file descriptors and use distinct I/O routines,
+Windows is one such platform. Any code mixing the two will not work on
+all platforms.
+
+=head1 RETURN VALUES
+
+BIO_s_socket() returns the socket BIO method.
+
+BIO_set_fd() always returns 1.
+
+BIO_get_fd() returns the file descriptor or -1 if the BIO has not
+been initialised.
+
+BIO_new_socket() returns the newly allocated BIO or NULL is an error
+occurred.
+
+=head1 SEE ALSO
+
+TBA