nes-proj/core/net/psock.c
Oliver Schmidt 1eda821a75 Fixed severe bug in PSOCK_READTO (?)
Either I found and fixed a severe bug in PSOCK_READTO() or I misunderstood something completely. To me PSOCK_READTO() is supposed to return if either the supplied character was read or if the user supplied buffer is exhausted - sor far so good.

However if the latter occurs up to now PSOCK_READTO() was continuing to process characters already read from the network (aka present in the uIP buffer) in order to check if the supplied character was found there and adjust the return value accordingly. But this means that the character processed this way were lost forever for the caller as the next call to PSOCK_READTO() would continue to read past the characters processed this way.

Therefore I removed that character processing altogether. So now if the user supplied buffer is exhausted before the supplied character is found the next call to PSOCK_READTO() starts exactly where previous call left off.
2013-02-10 15:41:34 +01:00

320 lines
9.2 KiB
C

/*
* Copyright (c) 2004, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* Author: Adam Dunkels <adam@sics.se>
*
*/
#include <string.h>
#include "net/psock.h"
#define STATE_NONE 0
#define STATE_ACKED 1
#define STATE_READ 2
#define STATE_BLOCKED_NEWDATA 3
#define STATE_BLOCKED_CLOSE 4
#define STATE_BLOCKED_SEND 5
#define STATE_DATA_SENT 6
/*
* Return value of the buffering functions that indicates that a
* buffer was not filled by incoming data.
*
*/
#define BUF_NOT_FULL 0
#define BUF_NOT_FOUND 0
/*
* Return value of the buffering functions that indicates that a
* buffer was completely filled by incoming data.
*
*/
#define BUF_FULL 1
/*
* Return value of the buffering functions that indicates that an
* end-marker byte was found.
*
*/
#define BUF_FOUND 2
/*---------------------------------------------------------------------------*/
static void
buf_setup(struct psock_buf *buf,
uint8_t *bufptr, uint16_t bufsize)
{
buf->ptr = bufptr;
buf->left = bufsize;
}
/*---------------------------------------------------------------------------*/
static uint8_t
buf_bufdata(struct psock_buf *buf, uint16_t len,
uint8_t **dataptr, uint16_t *datalen)
{
if(*datalen < buf->left) {
memcpy(buf->ptr, *dataptr, *datalen);
buf->ptr += *datalen;
buf->left -= *datalen;
*dataptr += *datalen;
*datalen = 0;
return BUF_NOT_FULL;
} else if(*datalen == buf->left) {
memcpy(buf->ptr, *dataptr, *datalen);
buf->ptr += *datalen;
buf->left = 0;
*dataptr += *datalen;
*datalen = 0;
return BUF_FULL;
} else {
memcpy(buf->ptr, *dataptr, buf->left);
buf->ptr += buf->left;
*datalen -= buf->left;
*dataptr += buf->left;
buf->left = 0;
return BUF_FULL;
}
}
/*---------------------------------------------------------------------------*/
static uint8_t
buf_bufto(CC_REGISTER_ARG struct psock_buf *buf, uint8_t endmarker,
CC_REGISTER_ARG uint8_t **dataptr, CC_REGISTER_ARG uint16_t *datalen)
{
uint8_t c;
while(buf->left > 0 && *datalen > 0) {
c = *buf->ptr = **dataptr;
++*dataptr;
++buf->ptr;
--*datalen;
--buf->left;
if(c == endmarker) {
return BUF_FOUND;
}
}
if(*datalen == 0) {
return BUF_NOT_FOUND;
}
return BUF_FULL;
}
/*---------------------------------------------------------------------------*/
static char
data_is_sent_and_acked(CC_REGISTER_ARG struct psock *s)
{
/* If data has previously been sent, and the data has been acked, we
increase the send pointer and call send_data() to send more
data. */
if(s->state != STATE_DATA_SENT || uip_rexmit()) {
if(s->sendlen > uip_mss()) {
uip_send(s->sendptr, uip_mss());
} else {
uip_send(s->sendptr, s->sendlen);
}
s->state = STATE_DATA_SENT;
return 0;
} else if(s->state == STATE_DATA_SENT && uip_acked()) {
if(s->sendlen > uip_mss()) {
s->sendlen -= uip_mss();
s->sendptr += uip_mss();
} else {
s->sendptr += s->sendlen;
s->sendlen = 0;
}
s->state = STATE_ACKED;
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
PT_THREAD(psock_send(CC_REGISTER_ARG struct psock *s, const uint8_t *buf,
unsigned int len))
{
PT_BEGIN(&s->psockpt);
/* If there is no data to send, we exit immediately. */
if(len == 0) {
PT_EXIT(&s->psockpt);
}
/* Save the length of and a pointer to the data that is to be
sent. */
s->sendptr = buf;
s->sendlen = len;
s->state = STATE_NONE;
/* We loop here until all data is sent. The s->sendlen variable is
updated by the data_sent() function. */
while(s->sendlen > 0) {
/*
* The protothread will wait here until all data has been
* acknowledged and sent (data_is_acked_and_send() returns 1).
*/
PT_WAIT_UNTIL(&s->psockpt, data_is_sent_and_acked(s));
}
s->state = STATE_NONE;
PT_END(&s->psockpt);
}
/*---------------------------------------------------------------------------*/
PT_THREAD(psock_generator_send(CC_REGISTER_ARG struct psock *s,
unsigned short (*generate)(void *), void *arg))
{
PT_BEGIN(&s->psockpt);
/* Ensure that there is a generator function to call. */
if(generate == NULL) {
PT_EXIT(&s->psockpt);
}
s->state = STATE_NONE;
do {
/* Call the generator function to generate the data in the
uip_appdata buffer. */
s->sendlen = generate(arg);
s->sendptr = uip_appdata;
if(s->sendlen > uip_mss()) {
uip_send(s->sendptr, uip_mss());
} else {
uip_send(s->sendptr, s->sendlen);
}
s->state = STATE_DATA_SENT;
/* Wait until all data is sent and acknowledged. */
// if (!s->sendlen) break; //useful debugging aid
PT_YIELD_UNTIL(&s->psockpt, uip_acked() || uip_rexmit());
} while(!uip_acked());
s->state = STATE_NONE;
PT_END(&s->psockpt);
}
/*---------------------------------------------------------------------------*/
uint16_t
psock_datalen(struct psock *psock)
{
return psock->bufsize - psock->buf.left;
}
/*---------------------------------------------------------------------------*/
char
psock_newdata(struct psock *s)
{
if(s->readlen > 0) {
/* There is data in the uip_appdata buffer that has not yet been
read with the PSOCK_READ functions. */
return 1;
} else if(s->state == STATE_READ) {
/* All data in uip_appdata buffer already consumed. */
s->state = STATE_BLOCKED_NEWDATA;
return 0;
} else if(uip_newdata()) {
/* There is new data that has not been consumed. */
return 1;
} else {
/* There is no new data. */
return 0;
}
}
/*---------------------------------------------------------------------------*/
PT_THREAD(psock_readto(CC_REGISTER_ARG struct psock *psock, unsigned char c))
{
PT_BEGIN(&psock->psockpt);
buf_setup(&psock->buf, psock->bufptr, psock->bufsize);
/* XXX: Should add buf_checkmarker() before do{} loop, if
incoming data has been handled while waiting for a write. */
do {
if(psock->readlen == 0) {
PT_WAIT_UNTIL(&psock->psockpt, psock_newdata(psock));
psock->state = STATE_READ;
psock->readptr = (uint8_t *)uip_appdata;
psock->readlen = uip_datalen();
}
} while(buf_bufto(&psock->buf, c,
&psock->readptr,
&psock->readlen) == BUF_NOT_FOUND);
if(psock_datalen(psock) == 0) {
psock->state = STATE_NONE;
PT_RESTART(&psock->psockpt);
}
PT_END(&psock->psockpt);
}
/*---------------------------------------------------------------------------*/
PT_THREAD(psock_readbuf_len(CC_REGISTER_ARG struct psock *psock, uint16_t len))
{
PT_BEGIN(&psock->psockpt);
buf_setup(&psock->buf, psock->bufptr, psock->bufsize);
/* XXX: Should add buf_checkmarker() before do{} loop, if
incoming data has been handled while waiting for a write. */
/* read len bytes or to end of data */
do {
if(psock->readlen == 0) {
PT_WAIT_UNTIL(&psock->psockpt, psock_newdata(psock));
psock->state = STATE_READ;
psock->readptr = (uint8_t *)uip_appdata;
psock->readlen = uip_datalen();
}
} while(buf_bufdata(&psock->buf, psock->bufsize,
&psock->readptr, &psock->readlen) == BUF_NOT_FULL &&
psock_datalen(psock) < len);
if(psock_datalen(psock) == 0) {
psock->state = STATE_NONE;
PT_RESTART(&psock->psockpt);
}
PT_END(&psock->psockpt);
}
/*---------------------------------------------------------------------------*/
void
psock_init(CC_REGISTER_ARG struct psock *psock,
uint8_t *buffer, unsigned int buffersize)
{
psock->state = STATE_NONE;
psock->readlen = 0;
psock->bufptr = buffer;
psock->bufsize = buffersize;
buf_setup(&psock->buf, buffer, buffersize);
PT_INIT(&psock->pt);
PT_INIT(&psock->psockpt);
}
/*---------------------------------------------------------------------------*/