server.c

这是有名的＜＜嵌入式系统TCP/IP应用层协议＞＞,M.Tim Jones 著

/*
 *  Embedded Command Line Interface
 *
 *  ./software/ch5/emcli/server.c
 *
 *  [e-mail]
 *
 */


#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <stdio.h>
#include <sys/un.h>
#include <unistd.h>
#include <time.h>
#include "handlers.h"

const char *salutation={"+OK -- Embedded CLI\n"}; 
const char *ready={"+OK\n"};
const char *notready={"+ERR\n"};

#define MAX_LINE	200

int   verbose = 0;
time_t startTime;
time_t lastConnect = 0;

#define EMCLI_PORT	9999

void handleConnection(int fd)
{
  int len, done=0, numArgs, status;
  char buffer[MAX_LINE+1];

  extern int parseCommand( char * );
  extern int doHelp( int );

  /* Send salutation... */
  len = write(fd, salutation, strlen(salutation));

  while (!done) {

    len = read(fd, buffer, MAX_LINE);
    if (len <= 0) return;
    buffer[len] = 0;

    numArgs = parseCommand(buffer);

    if ((buffer[0] == 0) || (buffer[0] == ' ') || (buffer[0] == '#')) {
      ; // Ignore blank/comment lines
      status = 1;

    } else if ((!strncmp(buffer, "quit", 4)) ||
               (!strncmp(buffer, "exit", 4))) {
      status = 0;
      done = 1;

    } else if (!strncmp(buffer, "help", 4)) {
      doHelp( fd );
      status = 0;

    } else if (!strncmp(buffer, "verbose", 7)) {
      if (verbose) verbose = 0;
      else verbose = 1;
      len = write(fd, (verbose) ? "Verbose=on \n" : "Verbose=off\n", 13);
      status = 0;

    } else if (!strncmp(buffer, "hexof", 5)) {
      status = convdec(fd);

    } else if (!strncmp(buffer, "decof", 5)) {
      status = convhex(fd);

    } else if (!strncmp(buffer, "uptime", 6)) {
      time_t curTime = time(NULL);
      sprintf(buffer, "%ld\n", curTime-startTime);
      len = write(fd, buffer, strlen(buffer));
      status = 0;

    } else if (!strncmp(buffer, "last", 4)) {
      if (lastConnect != (time_t)0) {
        sprintf(buffer, "%s", ctime(&lastConnect));
        len = write(fd, buffer, strlen(buffer));
      } else {
        len = write(fd, "none\n", 5);
      }
      status = 0;

    } else if (!strncmp(buffer, "who", 3)) {
      status = getpeer(fd);

    } else if (!strncmp(buffer, "push", 4)) {
      status = push(fd);

    } else if (!strncmp(buffer, "pop", 3)) {
      status = pop(fd);

    } else if ((!strncmp(buffer, "add", 3)) ||
               (!strncmp(buffer, "sub", 3)) ||
               (!strncmp(buffer, "mul", 3)) ||
               (!strncmp(buffer, "div", 3))) {
      status = mathop(fd, buffer[0]);

    } else {
      status = -1;

    }

    if (status == 0) {
      len = write(fd, ready, strlen(ready));
    } else if (status == -1) {
      len = write(fd, notready, strlen(notready));
    }

  }

  return;
}


int main(int argc, char **argv)
{
  int listenfd, connfd, on=1;
  socklen_t clilen;
  struct sockaddr_in cliaddr, servaddr;

  listenfd = socket(AF_INET, SOCK_STREAM, 0);

  /* Avoid TIME-WAIT on this socket and allow it to be immediately
   * reused.
   */
  setsockopt( listenfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on) );

  bzero(&servaddr, sizeof(servaddr));
  servaddr.sin_family = AF_INET;
  servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  servaddr.sin_port = htons(EMCLI_PORT);

  bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr));

  listen(listenfd, 1);

  startTime = time(NULL);

  for ( ; ; ) {

    clilen = sizeof(cliaddr);

    connfd = accept(listenfd, (struct sockaddr *)&cliaddr, &clilen);

    if (connfd <= 0) {
      break;
    }

    handleConnection(connfd);

    lastConnect = time(NULL);

    close(connfd);

  }

  close(listenfd);

  return 0;
}

/*
 *  Copyright (c) 2002 Charles River Media.  All rights reserved.
 * 
 *  Redistribution and use in source and binary forms, with or 
 *  without modification, is hereby granted without fee 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 Charles River Media 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 CHARLES RIVER MEDIA AND CONTRIBUTERS 
 * 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL CHARLES
 * RIVER MEDIA OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARAY, 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.
 */