api_lib.c

lwIP是瑞士计算机科学院（Swedish Institute of Computer Science）的Adam Dunkels等开发的一套用于嵌入式系统的开放源代码TCP/IP协议栈。Lwip既可

/*
 * Copyright (c) 2001-2004 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. 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]>
 *
 */

/* This is the part of the API that is linked with
   the application */

#include "lwip/opt.h"
#include "lwip/api.h"
#include "lwip/api_msg.h"
#include "lwip/memp.h"


struct
netbuf *netbuf_new(void)
{
  struct netbuf *buf;

  buf = memp_malloc(MEMP_NETBUF);
  if (buf != NULL) {
    buf->p = NULL;
    buf->ptr = NULL;
    return buf;
  } else {
    return NULL;
  }
}

void
netbuf_delete(struct netbuf *buf)
{
  if (buf != NULL) {
    if (buf->p != NULL) {
      pbuf_free(buf->p);
      buf->p = buf->ptr = NULL;
    }
    memp_free(MEMP_NETBUF, buf);
  }
}

void *
netbuf_alloc(struct netbuf *buf, u16_t size)
{
  /* Deallocate any previously allocated memory. */
  if (buf->p != NULL) {
    pbuf_free(buf->p);
  }
  buf->p = pbuf_alloc(PBUF_TRANSPORT, size, PBUF_RAM);
  if (buf->p == NULL) {
     return NULL;
  }
  buf->ptr = buf->p;
  return buf->p->payload;
}

void
netbuf_free(struct netbuf *buf)
{
  if (buf->p != NULL) {
    pbuf_free(buf->p);
  }
  buf->p = buf->ptr = NULL;
}

void
netbuf_ref(struct netbuf *buf, void *dataptr, u16_t size)
{
  if (buf->p != NULL) {
    pbuf_free(buf->p);
  }
  buf->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_REF);
  buf->p->payload = dataptr;
  buf->p->len = buf->p->tot_len = size;
  buf->ptr = buf->p;
}

void
netbuf_chain(struct netbuf *head, struct netbuf *tail)
{
  pbuf_chain(head->p, tail->p);
  head->ptr = head->p;
  memp_free(MEMP_NETBUF, tail);
}

u16_t
netbuf_len(struct netbuf *buf)
{
  return buf->p->tot_len;
}

err_t
netbuf_data(struct netbuf *buf, void **dataptr, u16_t *len)
{
  if (buf->ptr == NULL) {
    return ERR_BUF;
  }
  *dataptr = buf->ptr->payload;
  *len = buf->ptr->len;
  return ERR_OK;
}

s8_t
netbuf_next(struct netbuf *buf)
{
  if (buf->ptr->next == NULL) {
    return -1;
  }
  buf->ptr = buf->ptr->next;
  if (buf->ptr->next == NULL) {
    return 1;
  }
  return 0;
}

void
netbuf_first(struct netbuf *buf)
{
  buf->ptr = buf->p;
}

void
netbuf_copy_partial(struct netbuf *buf, void *dataptr, u16_t len, u16_t offset)
{
  struct pbuf *p;
  u16_t i, left;

  left = 0;

  if(buf == NULL || dataptr == NULL) {
    return;
  }
  
  /* This implementation is bad. It should use bcopy
     instead. */
  for(p = buf->p; left < len && p != NULL; p = p->next) {
    if (offset != 0 && offset >= p->len) {
      offset -= p->len;
    } else {    
      for(i = offset; i < p->len; ++i) {
  ((char *)dataptr)[left] = ((char *)p->payload)[i];
  if (++left >= len) {
    return;
  }
      }
      offset = 0;
    }
  }
}

void
netbuf_copy(struct netbuf *buf, void *dataptr, u16_t len)
{
  netbuf_copy_partial(buf, dataptr, len, 0);
}

struct ip_addr *
netbuf_fromaddr(struct netbuf *buf)
{
  return buf->fromaddr;
}

u16_t
netbuf_fromport(struct netbuf *buf)
{
  return buf->fromport;
}

struct
netconn *netconn_new_with_proto_and_callback(enum netconn_type t, u16_t proto,
                                   void (*callback)(struct netconn *, enum netconn_evt, u16_t len))
{
  struct netconn *conn;
  struct api_msg *msg;

  conn = memp_malloc(MEMP_NETCONN);
  if (conn == NULL) {
    return NULL;
  }
  
  conn->err = ERR_OK;
  conn->type = t;
  conn->pcb.tcp = NULL;

  if ((conn->mbox = sys_mbox_new()) == SYS_MBOX_NULL) {
    memp_free(MEMP_NETCONN, conn);
    return NULL;
  }
  conn->recvmbox = SYS_MBOX_NULL;
  conn->acceptmbox = SYS_MBOX_NULL;
  conn->sem = SYS_SEM_NULL;
  conn->state = NETCONN_NONE;
  conn->socket = 0;
  conn->callback = callback;
  conn->recv_avail = 0;

  if((msg = memp_malloc(MEMP_API_MSG)) == NULL) {
    memp_free(MEMP_NETCONN, conn);
    return NULL;
  }
  
  msg->type = API_MSG_NEWCONN;
  msg->msg.msg.bc.port = proto; /* misusing the port field */
  msg->msg.conn = conn;
  api_msg_post(msg);  
  sys_mbox_fetch(conn->mbox, NULL);
  memp_free(MEMP_API_MSG, msg);

  if ( conn->err != ERR_OK ) {
    memp_free(MEMP_NETCONN, conn);
    return NULL;
  }

  return conn;
}


struct
netconn *netconn_new(enum netconn_type t)
{
  return netconn_new_with_proto_and_callback(t,0,NULL);
}

struct
netconn *netconn_new_with_callback(enum netconn_type t,
                                   void (*callback)(struct netconn *, enum netconn_evt, u16_t len))
{
  return netconn_new_with_proto_and_callback(t,0,callback);
}


err_t
netconn_delete(struct netconn *conn)
{
  struct api_msg *msg;
  void *mem;
  
  if (conn == NULL) {
    return ERR_OK;
  }
  
  if ((msg = memp_malloc(MEMP_API_MSG)) == NULL) {
    return ERR_MEM;
  }
  
  msg->type = API_MSG_DELCONN;
  msg->msg.conn = conn;
  api_msg_post(msg);  
  sys_mbox_fetch(conn->mbox, NULL);
  memp_free(MEMP_API_MSG, msg);

  /* Drain the recvmbox. */
  if (conn->recvmbox != SYS_MBOX_NULL) {
    while (sys_arch_mbox_fetch(conn->recvmbox, &mem, 1) != SYS_ARCH_TIMEOUT) {
      if (conn->type == NETCONN_TCP) {
        if(mem != NULL)
          pbuf_free((struct pbuf *)mem);
      } else {
        netbuf_delete((struct netbuf *)mem);
      }
    }
    sys_mbox_free(conn->recvmbox);
    conn->recvmbox = SYS_MBOX_NULL;
  }
 

  /* Drain the acceptmbox. */
  if (conn->acceptmbox != SYS_MBOX_NULL) {
    while (sys_arch_mbox_fetch(conn->acceptmbox, &mem, 1) != SYS_ARCH_TIMEOUT) {
      netconn_delete((struct netconn *)mem);
    }
    
    sys_mbox_free(conn->acceptmbox);
    conn->acceptmbox = SYS_MBOX_NULL;
  }

  sys_mbox_free(conn->mbox);
  conn->mbox = SYS_MBOX_NULL;
  if (conn->sem != SYS_SEM_NULL) {
    sys_sem_free(conn->sem);
  }
  /*  conn->sem = SYS_SEM_NULL;*/
  memp_free(MEMP_NETCONN, conn);
  return ERR_OK;
}

enum netconn_type
netconn_type(struct netconn *conn)
{
  return conn->type;
}

err_t
netconn_peer(struct netconn *conn, struct ip_addr *addr,
       u16_t *port)
{
  switch (conn->type) {
  case NETCONN_RAW:
    /* return an error as connecting is only a helper for upper layers */
    return ERR_CONN;
  case NETCONN_UDPLITE:
  case NETCONN_UDPNOCHKSUM:
  case NETCONN_UDP:
    if (conn->pcb.udp == NULL ||
  ((conn->pcb.udp->flags & UDP_FLAGS_CONNECTED) == 0))
     return ERR_CONN;
    *addr = (conn->pcb.udp->remote_ip);
    *port = conn->pcb.udp->remote_port;
    break;
  case NETCONN_TCP:
    if (conn->pcb.tcp == NULL)
      return ERR_CONN;
    *addr = (conn->pcb.tcp->remote_ip);
    *port = conn->pcb.tcp->remote_port;
    break;
  }
  return (conn->err = ERR_OK);
}

err_t
netconn_addr(struct netconn *conn, struct ip_addr **addr,
       u16_t *port)
{
  switch (conn->type) {
  case NETCONN_RAW:
    *addr = &(conn->pcb.raw->local_ip);
    *port = conn->pcb.raw->protocol;
    break;
  case NETCONN_UDPLITE:
  case NETCONN_UDPNOCHKSUM:
  case NETCONN_UDP:
    *addr = &(conn->pcb.udp->local_ip);
    *port = conn->pcb.udp->local_port;
    break;
  case NETCONN_TCP:
    *addr = &(conn->pcb.tcp->local_ip);
    *port = conn->pcb.tcp->local_port;
    break;