httpd.c

这是一个典型的web的实验

/* httpd.c:  A very simple http server
 * Copyfight (C) 2003      Zou jian guo <[e-mail]>
 * Copyright (C) 2000  	   Lineo, Inc.  (www.lineo.com)
 * Copyright (c) 1997-1999 D. Jeff Dionne <[e-mail]>
 * Copyright (c) 1998      Kenneth Albanowski <[e-mail]>
 * Copyright (c) 1999      Nick Brok <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <sys/stat.h>
#include <dirent.h>
#include <signal.h>
#include <unistd.h>
#include <ctype.h>
#include "pthread.h"

#define DEBUG

int KEY_QUIT=0;
int TIMEOUT=30;

#ifndef O_BINARY
#define O_BINARY 0
#endif

char referrer[128];
int content_length;

#define SERVER_PORT 80

int PrintHeader(FILE *f, int content_type)
{
  alarm(TIMEOUT);
  fprintf(f,"HTTP/1.0 200 OK\n");
  switch (content_type)
  { 
   case 't':
    fprintf(f,"Content-type: text/plain\n");
    break;
   case 'g':
    fprintf(f,"Content-type: image/gif\n");
    break;
   case 'j':
    fprintf(f,"Content-type: image/jpeg\n");
    break;
   case 'h':
    fprintf(f,"Content-type: text/html\n");
    break;
  }
  fprintf(f,"Server: uClinux-httpd 0.2.2\n");
  fprintf(f,"Expires: 0\n");
  fprintf(f,"\n");
  alarm(0);
  return(0);
}

int DoJpeg(FILE *f, char *name)
{
  char *buf;
  FILE * infile;
  int count;
 
  if (!(infile = fopen(name, "r"))) {
    alarm(TIMEOUT);
    fprintf(stderr, "Unable to open JPEG file %s, %d\n", name, errno);
    fflush(f);
    alarm(0);
    return -1;
  }
 
  PrintHeader(f,'j');	

 
  copy(infile,f); /* prints the page */
 
  alarm(TIMEOUT);
  fclose(infile);
  alarm(0);
 
  return 0;
}

int DoGif(FILE *f, char *name)
{
  char *buf;
  FILE * infile;
  int count;

  if (!(infile = fopen(name, "r"))) {
    alarm(TIMEOUT);
    fprintf(stderr, "Unable to open GIF file %s, %d\n", name, errno);
    fflush(f);
    alarm(0);
    return -1;
  }
  
  PrintHeader(f,'g');

  copy(infile,f); /* prints the page */  

  alarm(TIMEOUT);
  fclose(infile);
  alarm(0);
  
  return 0;
}

int DoDir(FILE *f, char *name)
{
  char *buf;
  DIR * dir;
  struct dirent * dirent;

  if ((dir = opendir(name))== 0) {
    fprintf(stderr, "Unable to open directory %s, %d\n", name, errno);
    fflush(f);
    return -1;
  }
  
  PrintHeader(f,'h');
  
  alarm(TIMEOUT);
  fprintf(f, "<H1>Index of %s</H1>\n\n",name);
  alarm(0);

  if (name[strlen(name)-1] != '/') {
	strcat(name, "/");
  }
  
  while(dirent = readdir(dir)) {
	alarm(TIMEOUT);
  
	fprintf(f, "<p><a href=\"/%s%s\">%s</a></p>\n", name, dirent->d_name, dirent->d_name);
	alarm(0);
  }
  
  closedir(dir);
  return 0;
}

int DoHTML(FILE *f, char *name)
{
  char *buf;
  FILE *infile;
  int count;
  char * dir = 0;

  if (!(infile = fopen(name,"r"))) {
    alarm(TIMEOUT);
    fprintf(stderr, "Unable to open HTML file %s, %d\n", name, errno);
    fflush(f);
    alarm(0);
    return -1;
  }

  PrintHeader(f,'h');
  copy(infile,f); /* prints the page */  

  alarm(TIMEOUT);
  fclose(infile);
  alarm(0);

  return 0;
}

int DoText(FILE *f, char *name)
{
  char *buf;
  FILE *infile;
  int count;

  if (!(infile = fopen(name,"r"))) {
    alarm(TIMEOUT);
    fprintf(stderr, "Unable to open text file %s, %d\n", name, errno);
    fflush(f);
    alarm(0);
    return -1;
  }

  PrintHeader(f,'t');
  copy(infile,f); /* prints the page */  

  alarm(TIMEOUT);
  fclose(infile);
  alarm(0);

  return 0;
}

int ParseReq(FILE *f, char *r)
{
  	char *bp;
  	struct stat stbuf;
  	char * arg;
  	char * c;
  	int e;
  	int raw;

#ifdef DEBUG
  	printf("req is '%s'\n", r);
#endif
  
  	while(*(++r) != ' ');  /*skip non-white space*/
  	while(isspace(*r))
  		r++;
  
  	while (*r == '/')
  		r++;
  	bp = r;
  
  	while(*r && (*(r) != ' ') && (*(r) != '?'))
  		r++;
  	
#ifdef DEBUG
  	printf("bp='%s' %x, r='%s' \n", bp, *bp,r);
#endif
  	
  	if (*r == '?')
  	{
  		char * e;
  		*r = 0;
  		arg = r+1;
  		if (e = strchr(arg,' ')) 
		{
  			*e = '\0';
  		}
  	} else 
    {
  		arg = 0;
	  	*r = 0;
    }
  
  	c = bp;

/*zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz*/    
  	if (c[0] == 0x20){
		c[0]='.';
		c[1]='\0'; 
	}
/*zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz*/    
	if(c[0] == '\0') strcat(c,".");
		
	if (c && !stat(c, &stbuf)) 
  	{
    	if (S_ISDIR(stbuf.st_mode)) 
    	{ 
    		char * end = c + strlen(c);
    		strcat(c, "/index.html");
    		if (!stat(c, &stbuf)) 
        	{
    			DoHTML(f, c);
    		} 
        	else 
        	{
  				*end = '\0';
				DoDir(f,c);
			}
    	}
    	else if (!strcmp(r - 4, ".gif"))
      		DoGif(f,c);
        else if (!strcmp(r - 4, ".jpg") || !strcmp(r - 5, ".jpeg"))
          	DoJpeg(f,c);
        else if (!strcmp(r - 4, ".htm") || !strcmp(r - 5, ".html"))
            DoHTML(f,c);
             else
                  DoText(f,c);
	} 
	else{
	  	PrintHeader(f,'h');
  		alarm(TIMEOUT);
	  	fprintf(f, "<html><head><title>404 File Not Found</title></head>\n");
		fprintf(f, "<body>The requested URL was not found on this server</body></html>\n");
	  	alarm(0);
    }
  	return 0;
}

void sigalrm(int signo)
{
	/* got an alarm, exit & recycle */
	exit(0);
}

int HandleConnect(int fd)
{
  FILE *f;

  char buf[160];
  char buf1[160];

  f = fdopen(fd,"a+");
  if (!f) {
    fprintf(stderr, "httpd: Unable to open httpd input fd, error %d\n", errno);
    alarm(TIMEOUT);
    close(fd);
    alarm(0);
    return 0;
  }
  setbuf(f, 0);

  alarm(TIMEOUT);

  if (!fgets(buf, 150, f)) {
    fprintf(stderr, "httpd: Error reading connection, error %d\n", errno);
    fclose(f);
    alarm(0);
    return 0;
  }
#ifdef DEBUG
  	printf("buf = '%s'\n", buf);
#endif
    
  	alarm(0);

  	referrer[0] = '\0';
  	content_length = -1;
    
 	alarm(TIMEOUT);
	//read other line to parse Rrferrer and content_length infomation
	while (fgets(buf1, 150, f) && (strlen(buf1) > 2)) {
  		alarm(TIMEOUT);
		#ifdef DEBUG
	    	printf("Got buf1 '%s'\n", buf1);
		#endif
    	if (!strncasecmp(buf1, "Referer:", 8)) {
	      	char * c = buf1+8;
    	  	while (isspace(*c))
				c++;
		    strcpy(referrer, c);
    	} 
    	else if (!strncasecmp(buf1, "Referrer:", 9)) {
      		char * c = buf1+9;
     		 while (isspace(*c))
				c++;
      		strcpy(referrer, c);
    	} 
    	else if (!strncasecmp(buf1, "Content-length:", 15)) {
      		content_length = atoi(buf1+15);
    	} 
  	}
  	alarm(0);
  
  	if (ferror(f)) {
    	fprintf(stderr, "http: Error continuing reading connection, error %d\n", errno);
	    fclose(f);
    	return 0;
  	}	
    
  	ParseReq(f, buf);

  	alarm(TIMEOUT);
  	fflush(f);
  	fclose(f);
  	alarm(0);
  	return 1;
}



void* key(void* data)
{
	int c;
	for(;;){
		c=getchar();	
		if(c == 'q' || c == 'Q'){
			KEY_QUIT=1;
			exit(10);
			break;
		}
	}
		
}

int main(int argc, char *argv[])
{
  int fd, s;
  int len;
  volatile int true = 1;
  struct sockaddr_in ec;
  struct sockaddr_in server_sockaddr;
	  
  pthread_t th_key;
  void * retval;


  signal(SIGCHLD, SIG_IGN);
  signal(SIGPIPE, SIG_IGN);
  signal(SIGALRM, sigalrm);

  chroot(HTTPD_DOCUMENT_ROOT);
  printf("starting httpd...\n");
  printf("press q to quit.\n");
//  chdir("/");

  if (argc > 1 && !strcmp(argv[1], "-i")) {
    /* I'm running from inetd, handle the request on stdin */
    fclose(stderr);
    HandleConnect(0);
    exit(0);
  }

  if((s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
    perror("Unable to obtain network");
    exit(1);
  }
  
  if((setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (void *)&true, 
		 sizeof(true))) == -1) {
    perror("setsockopt failed");
    exit(1);
  }

  server_sockaddr.sin_family = AF_INET;
  server_sockaddr.sin_port = htons(SERVER_PORT);
  server_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  
  if(bind(s, (struct sockaddr *)&server_sockaddr, 
	  sizeof(server_sockaddr)) == -1)  {
    perror("Unable to bind socket");
    exit(1);
  }

  if(listen(s, 8*3) == -1) { /* Arbitrary, 8 files/page, 3 clients */
    perror("Unable to listen");
    exit(4);
  }

  
   	pthread_create(&th_key, NULL, key, 0);
  /* Wait until producer and consumer finish. */
  printf("wait for connection.\n");	
  while (1) {
	  
    len = sizeof(ec);
    if((fd = accept(s, (void *)&ec, &len)) == -1) {
      exit(5);
      close(s);
    }
    HandleConnect(fd);
	
  }
  pthread_join(th_key, &retval);
}