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