httpd.c

来自「最新版IAR FOR ARM（EWARM）5.11中的代码例子」· C语言 代码 · 共 294 行

/*
 * Copyright (c) 2001-2003 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <[e-mail]>
 *
 */

#include "lwip/opt.h"

#include "lwip/debug.h"

#include "lwip/stats.h"

#include "httpd.h"

#include "lwip/tcp.h"

#include "fs.h"

#include <string.h>

struct http_state {
  struct fs_file *handle;
  char *file;
  u32_t left;
  u8_t retries;
};

/*-----------------------------------------------------------------------------------*/
static void
conn_err(void *arg, err_t err)
{
  struct http_state *hs;

  if(arg)
  {
      hs = arg;
      if(hs->handle) {
        fs_close(hs->handle);
        hs->handle = NULL;
      }
      mem_free(hs);
  }
}
/*-----------------------------------------------------------------------------------*/
static void
close_conn(struct tcp_pcb *pcb, struct http_state *hs)
{
  tcp_arg(pcb, NULL);
  tcp_sent(pcb, NULL);
  tcp_recv(pcb, NULL);
  if(hs->handle) {
    fs_close(hs->handle);
    hs->handle = NULL;
  }
  mem_free(hs);
  tcp_close(pcb);
}
/*-----------------------------------------------------------------------------------*/
static void
send_data(struct tcp_pcb *pcb, struct http_state *hs)
{
  err_t err;
  u16_t len;

  if(hs->left == 0)
  {
    int count;
    static char buf[3][2*TCP_MSS];
    static int index = 0;

    count = 2*TCP_MSS;
    hs->file = buf[index];
    index++;
    if(index > 2) {
      index = 0;
    }
    if(count > (2*pcb->mss)) {
      count = 2*pcb->mss;
    }
    count = fs_read(hs->handle, hs->file, count);
    if(count < 0)
    {
      fs_close(hs->handle);
      hs->handle = NULL;
      close_conn(pcb, hs);
      return;
    }
    hs->left = count;
  }

  /* We cannot send more data than space available in the send
     buffer. */
  if (tcp_sndbuf(pcb) < hs->left) {
    len = tcp_sndbuf(pcb);
  } else {
    len = hs->left;
  }
  if(len > (2*pcb->mss))
  {
    len = 2*pcb->mss;
  }

  do {
    err = tcp_write(pcb, hs->file, len, 0);
    if (err == ERR_MEM) {
      len /= 2;
    }
  } while (err == ERR_MEM && len > 1);

  if (err == ERR_OK) {
    tcp_output(pcb);
    hs->file += len;
    hs->left -= len;
  /*  } else {
    printf("send_data: error %s len %d %d\n", lwip_strerr(err), len, tcp_sndbuf(pcb));*/
  }
}
/*-----------------------------------------------------------------------------------*/
static err_t
http_poll(void *arg, struct tcp_pcb *pcb)
{
  struct http_state *hs;

  hs = arg;

  /*  printf("Polll\n");*/
  if (hs == NULL) {
    /*    printf("Null, close\n");*/
    tcp_abort(pcb);
    return ERR_ABRT;
  } else {
    ++hs->retries;
    if (hs->retries == 4) {
      tcp_abort(pcb);
      return ERR_ABRT;
    }
    send_data(pcb, hs);
  }

  return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
static err_t
http_sent(void *arg, struct tcp_pcb *pcb, u16_t len)
{
  struct http_state *hs;

  hs = arg;

  hs->retries = 0;

  send_data(pcb, hs);

  return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
static err_t
http_recv(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err)
{
  int i;
  char *data;
  struct fs_file *file;
  struct http_state *hs;

  hs = arg;

  if (err == ERR_OK && p != NULL) {

    /* Inform TCP that we have taken the data. */
    tcp_recved(pcb, p->tot_len);

    if (hs->handle == NULL) {
      data = p->payload;

      if (strncmp(data, "GET ", 4) == 0) {
    for(i = 0; i < 40; i++) {
      if (((char *)data + 4)[i] == ' ' ||
         ((char *)data + 4)[i] == '\r' ||
         ((char *)data + 4)[i] == '\n') {
        ((char *)data + 4)[i] = 0;
      }
    }

    if (*(char *)(data + 4) == '/' &&
       *(char *)(data + 5) == 0) {
      file = fs_open("/index.html");
    } else {
        file = fs_open((char *)data + 4);
        if(file == NULL) {
          file = fs_open("/404.html");
        }
    }
    hs->handle = file;
    hs->file = file->data;
    hs->left = file->len;
    hs->retries = 0;
    /*    printf("data %p len %ld\n", hs->file, hs->left);*/

    pbuf_free(p);
    send_data(pcb, hs);

    /* Tell TCP that we wish be to informed of data that has been
       successfully sent by a call to the http_sent() function. */
    tcp_sent(pcb, http_sent);
      } else {
    pbuf_free(p);
    close_conn(pcb, hs);
      }
    } else {
      pbuf_free(p);
    }
  }

  if (err == ERR_OK && p == NULL) {
    close_conn(pcb, hs);
  }
  return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
static err_t
http_accept(void *arg, struct tcp_pcb *pcb, err_t err)
{
  struct http_state *hs;

  tcp_setprio(pcb, TCP_PRIO_MIN);

  /* Allocate memory for the structure that holds the state of the
     connection. */
  hs = mem_malloc(sizeof(struct http_state));

  if (hs == NULL) {
    //printf("http_accept: Out of memory\n");
    return ERR_MEM;
  }

  /* Initialize the structure. */
  hs->handle = NULL;
  hs->file = NULL;
  hs->left = 0;
  hs->retries = 0;

  /* Tell TCP that this is the structure we wish to be passed for our
     callbacks. */
  tcp_arg(pcb, hs);

  /* Tell TCP that we wish to be informed of incoming data by a call
     to the http_recv() function. */
  tcp_recv(pcb, http_recv);

  tcp_err(pcb, conn_err);

  tcp_poll(pcb, http_poll, 4);
  return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
void
httpd_init(void)
{
  struct tcp_pcb *pcb;

  pcb = tcp_new();
  tcp_bind(pcb, IP_ADDR_ANY, 80);
  pcb = tcp_listen(pcb);
  tcp_accept(pcb, http_accept);
}
/*-----------------------------------------------------------------------------------*/