Projects/Incomplete/Webserver/Lib/uip/psock.c

   1 /*
   2  * Copyright (c) 2004, Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the Institute nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * This file is part of the uIP TCP/IP stack
  30  *
  31  * Author: Adam Dunkels <adam@sics.se>
  32  *
  33  * $Id: psock.c,v 1.2 2006/06/12 08:00:30 adam Exp $
  34  */
  35
  36 #include <stdio.h>
  37 #include <string.h>
  38
  39 #include "uipopt.h"
  40 #include "psock.h"
  41 #include "uip.h"
  42
  43 #define STATE_NONE 0
  44 #define STATE_ACKED 1
  45 #define STATE_READ 2
  46 #define STATE_BLOCKED_NEWDATA 3
  47 #define STATE_BLOCKED_CLOSE 4
  48 #define STATE_BLOCKED_SEND 5
  49 #define STATE_DATA_SENT 6
  50
  51 /*
  52  * Return value of the buffering functions that indicates that a
  53  * buffer was not filled by incoming data.
  54  *
  55  */
  56 #define BUF_NOT_FULL 0
  57 #define BUF_NOT_FOUND 0
  58
  59 /*
  60  * Return value of the buffering functions that indicates that a
  61  * buffer was completely filled by incoming data.
  62  *
  63  */
  64 #define BUF_FULL 1
  65
  66 /*
  67  * Return value of the buffering functions that indicates that an
  68  * end-marker byte was found.
  69  *
  70  */
  71 #define BUF_FOUND 2
  72
  73 /*---------------------------------------------------------------------------*/
  74 static void
  75 buf_setup(struct psock_buf *buf,
  76           u8_t *bufptr, u16_t bufsize)
  77 {
  78   buf->ptr = bufptr;
  79   buf->left = bufsize;
  80 }
  81 /*---------------------------------------------------------------------------*/
  82 static u8_t
  83 buf_bufdata(struct psock_buf *buf, u16_t len,
  84             u8_t **dataptr, u16_t *datalen)
  85 {
  86   if(*datalen < buf->left) {
  87     memcpy(buf->ptr, *dataptr, *datalen);
  88     buf->ptr += *datalen;
  89     buf->left -= *datalen;
  90     *dataptr += *datalen;
  91     *datalen = 0;
  92     return BUF_NOT_FULL;
  93   } else if(*datalen == buf->left) {
  94     memcpy(buf->ptr, *dataptr, *datalen);
  95     buf->ptr += *datalen;
  96     buf->left = 0;
  97     *dataptr += *datalen;
  98     *datalen = 0;
  99     return BUF_FULL;
 100   } else {
 101     memcpy(buf->ptr, *dataptr, buf->left);
 102     buf->ptr += buf->left;
 103     *datalen -= buf->left;
 104     *dataptr += buf->left;
 105     buf->left = 0;
 106     return BUF_FULL;
 107   }
 108 }
 109 /*---------------------------------------------------------------------------*/
 110 static u8_t
 111 buf_bufto(register struct psock_buf *buf, u8_t endmarker,
 112           register u8_t **dataptr, register u16_t *datalen)
 113 {
 114   u8_t c;
 115   while(buf->left > 0 && *datalen > 0) {
 116     c = *buf->ptr = **dataptr;
 117     ++*dataptr;
 118     ++buf->ptr;
 119     --*datalen;
 120     --buf->left;
 121
 122     if(c == endmarker) {
 123       return BUF_FOUND;
 124     }
 125   }
 126
 127   if(*datalen == 0) {
 128     return BUF_NOT_FOUND;
 129   }
 130
 131   while(*datalen > 0) {
 132     c = **dataptr;
 133     --*datalen;
 134     ++*dataptr;
 135
 136     if(c == endmarker) {
 137       return BUF_FOUND | BUF_FULL;
 138     }
 139   }
 140
 141   return BUF_FULL;
 142 }
 143 /*---------------------------------------------------------------------------*/
 144 static char
 145 send_data(register struct psock *s)
 146 {
 147   if(s->state != STATE_DATA_SENT || uip_rexmit()) {
 148     if(s->sendlen > uip_mss()) {
 149       uip_send(s->sendptr, uip_mss());
 150     } else {
 151       uip_send(s->sendptr, s->sendlen);
 152     }
 153     s->state = STATE_DATA_SENT;
 154     return 1;
 155   }
 156   return 0;
 157 }
 158 /*---------------------------------------------------------------------------*/
 159 static char
 160 data_acked(register struct psock *s)
 161 {
 162   if(s->state == STATE_DATA_SENT && uip_acked()) {
 163     if(s->sendlen > uip_mss()) {
 164       s->sendlen -= uip_mss();
 165       s->sendptr += uip_mss();
 166     } else {
 167       s->sendptr += s->sendlen;
 168       s->sendlen = 0;
 169     }
 170     s->state = STATE_ACKED;
 171     return 1;
 172   }
 173   return 0;
 174 }
 175 /*---------------------------------------------------------------------------*/
 176 PT_THREAD(psock_send(register struct psock *s, const char *buf,
 177                      unsigned int len))
 178 {
 179   PT_BEGIN(&s->psockpt);
 180
 181   /* If there is no data to send, we exit immediately. */
 182   if(len == 0) {
 183     PT_EXIT(&s->psockpt);
 184   }
 185
 186   /* Save the length of and a pointer to the data that is to be
 187      sent. */
 188   s->sendptr = buf;
 189   s->sendlen = len;
 190
 191   s->state = STATE_NONE;
 192
 193   /* We loop here until all data is sent. The s->sendlen variable is
 194      updated by the data_sent() function. */
 195   while(s->sendlen > 0) {
 196
 197     /*
 198      * The condition for this PT_WAIT_UNTIL is a little tricky: the
 199      * protothread will wait here until all data has been acknowledged
 200      * (data_acked() returns true) and until all data has been sent
 201      * (send_data() returns true). The two functions data_acked() and
 202      * send_data() must be called in succession to ensure that all
 203      * data is sent. Therefore the & operator is used instead of the
 204      * && operator, which would cause only the data_acked() function
 205      * to be called when it returns false.
 206      */
 207     PT_WAIT_UNTIL(&s->psockpt, data_acked(s) & send_data(s));
 208   }
 209
 210   s->state = STATE_NONE;
 211
 212   PT_END(&s->psockpt);
 213 }
 214 /*---------------------------------------------------------------------------*/
 215 PT_THREAD(psock_generator_send(register struct psock *s,
 216                                unsigned short (*generate)(void *), void *arg))
 217 {
 218   PT_BEGIN(&s->psockpt);
 219
 220   /* Ensure that there is a generator function to call. */
 221   if(generate == NULL) {
 222     PT_EXIT(&s->psockpt);
 223   }
 224
 225   /* Call the generator function to generate the data in the
 226      uip_appdata buffer. */
 227   s->sendlen = generate(arg);
 228   s->sendptr = uip_appdata;
 229
 230   s->state = STATE_NONE;
 231   do {
 232     /* Call the generator function again if we are called to perform a
 233        retransmission. */
 234     if(uip_rexmit()) {
 235       generate(arg);
 236     }
 237     /* Wait until all data is sent and acknowledged. */
 238     PT_WAIT_UNTIL(&s->psockpt, data_acked(s) & send_data(s));
 239   } while(s->sendlen > 0);
 240
 241   s->state = STATE_NONE;
 242
 243   PT_END(&s->psockpt);
 244 }
 245 /*---------------------------------------------------------------------------*/
 246 u16_t
 247 psock_datalen(struct psock *psock)
 248 {
 249   return psock->bufsize - psock->buf.left;
 250 }
 251 /*---------------------------------------------------------------------------*/
 252 char
 253 psock_newdata(struct psock *s)
 254 {
 255   if(s->readlen > 0) {
 256     /* There is data in the uip_appdata buffer that has not yet been
 257        read with the PSOCK_READ functions. */
 258     return 1;
 259   } else if(s->state == STATE_READ) {
 260     /* All data in uip_appdata buffer already consumed. */
 261     s->state = STATE_BLOCKED_NEWDATA;
 262     return 0;
 263   } else if(uip_newdata()) {
 264     /* There is new data that has not been consumed. */
 265     return 1;
 266   } else {
 267     /* There is no new data. */
 268     return 0;
 269   }
 270 }
 271 /*---------------------------------------------------------------------------*/
 272 PT_THREAD(psock_readto(register struct psock *psock, unsigned char c))
 273 {
 274   PT_BEGIN(&psock->psockpt);
 275
 276   buf_setup(&psock->buf, psock->bufptr, psock->bufsize);
 277
 278   /* XXX: Should add buf_checkmarker() before do{} loop, if
 279      incoming data has been handled while waiting for a write. */
 280
 281   do {
 282     if(psock->readlen == 0) {
 283       PT_WAIT_UNTIL(&psock->psockpt, psock_newdata(psock));
 284       psock->state = STATE_READ;
 285       psock->readptr = (u8_t *)uip_appdata;
 286       psock->readlen = uip_datalen();
 287     }
 288   } while((buf_bufto(&psock->buf, c,
 289                      &psock->readptr,
 290                      &psock->readlen) & BUF_FOUND) == 0);
 291
 292   if(psock_datalen(psock) == 0) {
 293     psock->state = STATE_NONE;
 294     PT_RESTART(&psock->psockpt);
 295   }
 296   PT_END(&psock->psockpt);
 297 }
 298 /*---------------------------------------------------------------------------*/
 299 PT_THREAD(psock_readbuf(register struct psock *psock))
 300 {
 301   PT_BEGIN(&psock->psockpt);
 302
 303   buf_setup(&psock->buf, psock->bufptr, psock->bufsize);
 304
 305   /* XXX: Should add buf_checkmarker() before do{} loop, if
 306      incoming data has been handled while waiting for a write. */
 307
 308   do {
 309     if(psock->readlen == 0) {
 310       PT_WAIT_UNTIL(&psock->psockpt, psock_newdata(psock));
 311       printf("Waited for newdata\n");
 312       psock->state = STATE_READ;
 313       psock->readptr = (u8_t *)uip_appdata;
 314       psock->readlen = uip_datalen();
 315     }
 316   } while(buf_bufdata(&psock->buf, psock->bufsize,
 317                          &psock->readptr,
 318                          &psock->readlen) != BUF_FULL);
 319
 320   if(psock_datalen(psock) == 0) {
 321     psock->state = STATE_NONE;
 322     PT_RESTART(&psock->psockpt);
 323   }
 324   PT_END(&psock->psockpt);
 325 }
 326 /*---------------------------------------------------------------------------*/
 327 void
 328 psock_init(register struct psock *psock, char *buffer, unsigned int buffersize)
 329 {
 330   psock->state = STATE_NONE;
 331   psock->readlen = 0;
 332   psock->bufptr = buffer;
 333   psock->bufsize = buffersize;
 334   buf_setup(&psock->buf, buffer, buffersize);
 335   PT_INIT(&psock->pt);
 336   PT_INIT(&psock->psockpt);
 337 }
 338 /*---------------------------------------------------------------------------*/