1 // Copyright (c) 2008 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 // Written in NSPR style to also be suitable for adding to the NSS demo suite 5 6 #ifndef __MEMIO_H 7 #define __MEMIO_H 8 #pragma once 9 10 #include <stddef.h> 11 12 #ifdef __cplusplus 13 extern "C" { 14 #endif 15 16 #include "prio.h" 17 18 /* Opaque structure. Really just a more typesafe alias for PRFilePrivate. */ 19 struct memio_Private; 20 typedef struct memio_Private memio_Private; 21 22 /*---------------------------------------------------------------------- 23 NSPR I/O layer that terminates in a pair of circular buffers 24 rather than talking to the real network. 25 To use this with NSS: 26 1) call memio_CreateIOLayer to create a fake NSPR socket 27 2) call SSL_ImportFD to ssl-ify the socket 28 3) Do your own networking calls to set up a TCP connection 29 4) call memio_SetPeerName to tell NSS about the other end of the connection 30 5) While at the same time doing plaintext nonblocking NSPR I/O as 31 usual to the nspr file descriptor returned by SSL_ImportFD, 32 your app must shuttle encrypted data between 33 the real network and memio's network buffers. 34 memio_GetReadParams/memio_PutReadResult 35 are the hooks you need to pump data into memio's input buffer, 36 and memio_GetWriteParams/memio_PutWriteResult 37 are the hooks you need to pump data out of memio's output buffer. 38 ----------------------------------------------------------------------*/ 39 40 /* Create the I/O layer and its two circular buffers. */ 41 PRFileDesc *memio_CreateIOLayer(int bufsize); 42 43 /* Must call before trying to make an ssl connection */ 44 void memio_SetPeerName(PRFileDesc *fd, const PRNetAddr *peername); 45 46 /* Return a private pointer needed by the following 47 * four functions. (We could have passed a PRFileDesc to 48 * them, but that would be slower. Better for the caller 49 * to grab the pointer once and cache it. 50 * This may be a premature optimization.) 51 */ 52 memio_Private *memio_GetSecret(PRFileDesc *fd); 53 54 /* Ask memio where to put bytes from the network, and how many it can handle. 55 * Returns bytes available to write, or 0 if none available. 56 * Puts current buffer position into *buf. 57 */ 58 int memio_GetReadParams(memio_Private *secret, char **buf); 59 60 /* Tell memio how many bytes were read from the network. 61 * If bytes_read is 0, causes EOF to be reported to 62 * NSS after it reads the last byte from the circular buffer. 63 * If bytes_read is < 0, it is treated as an NSPR error code. 64 * See nspr/pr/src/md/unix/unix_errors.c for how to 65 * map from Unix errors to NSPR error codes. 66 * On EWOULDBLOCK or the equivalent, don't call this function. 67 */ 68 void memio_PutReadResult(memio_Private *secret, int bytes_read); 69 70 /* Ask memio what data it has to send to the network. 71 * Returns up to two buffers of data by writing the positions and lengths into 72 * |buf1|, |len1| and |buf2|, |len2|. 73 */ 74 void memio_GetWriteParams(memio_Private *secret, 75 const char **buf1, unsigned int *len1, 76 const char **buf2, unsigned int *len2); 77 78 /* Tell memio how many bytes were sent to the network. 79 * If bytes_written is < 0, it is treated as an NSPR error code. 80 * See nspr/pr/src/md/unix/unix_errors.c for how to 81 * map from Unix errors to NSPR error codes. 82 * On EWOULDBLOCK or the equivalent, don't call this function. 83 */ 84 void memio_PutWriteResult(memio_Private *secret, int bytes_written); 85 86 87 #ifdef __cplusplus 88 } 89 #endif 90 91 #endif 92