windows版tinyhttpd

单线程，同步阻塞的socket。去掉了cgi的功能，只处理静态文件请求，改了accept_request中的几处bug。

/* J. David's webserver */
/* This is a simple webserver.
 * Created November 1999 by J. David Blackstone.
 * CSE 4344 (Network concepts), Prof. Zeigler
 * University of Texas at Arlington
 */
/* This program compiles for Sparc Solaris 2.6.
 * To compile for Linux:
 *  1) Comment out the #include <pthread.h> line.
 *  2) Comment out the line that defines the variable newthread.
 *  3) Comment out the two lines that run pthread_create().
 *  4) Uncomment the line that runs accept_request().
 *  5) Remove -lsocket from the Makefile.
 */
#include <WinSock2.h>
#include <stdio.h>
#include <sys/types.h>
#include <ctype.h>
#include <string.h>
#include <sys/stat.h>
#include <stdlib.h>

#pragma warning(disable : 4267)

#define ISspace(x) isspace((int)(x))

#define SERVER_STRING "Server: bdsoftmgr httpd/0.1.0\r\n"

void accept_request(SOCKET);
void bad_request(int);
void cat(SOCKET, FILE *);
void cannot_execute(int);
void error_die(const char *);
void execute_cgi(int, const char *, const char *, const char *);
int get_line(SOCKET, char *, int);
void headers(SOCKET, const char *);
void not_found(SOCKET);
void serve_file(SOCKET, const char *);
SOCKET startup(u_short *);
void unimplemented(SOCKET);
void discardheaders(SOCKET);

/**********************************************************************/
/* A request has caused a call to accept() on the server port to
 * return.  Process the request appropriately.
 * Parameters: the socket connected to the client */
/**********************************************************************/
void accept_request(SOCKET client)
{
 char buf[1024];
 int numchars;
 char method[255];
 char url[255];
 char path[512];
 size_t i, j;
 struct stat st;

 char *query_string = NULL;

 numchars = get_line(client, buf, sizeof(buf));
 i = 0; j = 0; 
 while (j < numchars && !ISspace(buf[j]) && (i < sizeof(method) - 1))
 {
  method[i] = buf[j];
  i++; j++;
 }
 method[i] = '\0';

 if (_stricmp(method, "GET") != 0)		// 只处理GET请求
 {
  if (numchars > 0)
	  discardheaders(client);
  
  unimplemented(client);
  closesocket(client);
  return;
 }

 i = 0;
 while (ISspace(buf[j]) && (j < sizeof(buf)))
  j++;
 while (!ISspace(buf[j]) && (i < sizeof(url) - 1) && (j < sizeof(buf)))
 {
  url[i] = buf[j];
  i++; j++;
 }
 url[i] = '\0';

 if (_stricmp(method, "GET") == 0)
 {
  query_string = url;
  while ((*query_string != '?') && (*query_string != '\0'))
   query_string++;
  if (*query_string == '?')
  {
   *query_string = '\0';
   query_string++;
  }
 }

 sprintf_s(path, 512, "htdocs%s", url);
 if (path[strlen(path) - 1] == '/')
  strcat_s(path, 512, "index.html");
 if (stat(path, &st) == -1) {
  if (numchars > 0)
   discardheaders(client);
  not_found(client);
 }
 else
 {
  if ((st.st_mode & S_IFMT) == S_IFDIR)
   strcat_s(path, 512, "/index.html");
  serve_file(client, path);
 }

 closesocket(client);
}

/**********************************************************************/
/* Inform the client that a request it has made has a problem.
 * Parameters: client socket */
/**********************************************************************/
void bad_request(int client)
{
 char buf[1024];

 sprintf_s(buf, 1024, "HTTP/1.0 400 BAD REQUEST\r\n");
 send(client, buf, sizeof(buf), 0);
 sprintf_s(buf, 1024, "Content-type: text/html\r\n");
 send(client, buf, sizeof(buf), 0);
 sprintf_s(buf, 1024, "\r\n");
 send(client, buf, sizeof(buf), 0);
 sprintf_s(buf, 1024, "<P>Your browser sent a bad request, ");
 send(client, buf, sizeof(buf), 0);
 sprintf_s(buf, 1024, "such as a POST without a Content-Length.\r\n");
 send(client, buf, sizeof(buf), 0);
}

/**********************************************************************/
/* Put the entire contents of a file out on a socket.  This function
 * is named after the UNIX "cat" command, because it might have been
 * easier just to do something like pipe, fork, and exec("cat").
 * Parameters: the client socket descriptor
 *             FILE pointer for the file to cat */
/**********************************************************************/
void cat(SOCKET client, FILE *resource)
{
 char buf[1024];

 fgets(buf, sizeof(buf), resource);
 while (!feof(resource))
 {
  send(client, buf, strlen(buf), 0);
  fgets(buf, sizeof(buf), resource);
 }
}

/**********************************************************************/
/* Inform the client that a CGI script could not be executed.
 * Parameter: the client socket descriptor. */
/**********************************************************************/
void cannot_execute(int client)
{
 char buf[1024];

 sprintf_s(buf, 1024, "HTTP/1.0 500 Internal Server Error\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "Content-type: text/html\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "<P>Error prohibited CGI execution.\r\n");
 send(client, buf, strlen(buf), 0);
}

/**********************************************************************/
/* Print out an error message with perror() (for system errors; based
 * on value of errno, which indicates system call errors) and exit the
 * program indicating an error. */
/**********************************************************************/
void error_die(const char *sc)
{
 perror(sc);
 exit(1);
}

/**********************************************************************/
/* Get a line from a socket, whether the line ends in a newline,
 * carriage return, or a CRLF combination.  Terminates the string read
 * with a null character.  If no newline indicator is found before the
 * end of the buffer, the string is terminated with a null.  If any of
 * the above three line terminators is read, the last character of the
 * string will be a linefeed and the string will be terminated with a
 * null character.
 * Parameters: the socket descriptor
 *             the buffer to save the data in
 *             the size of the buffer
 * Returns: the number of bytes stored (excluding null) */
/**********************************************************************/
int get_line(SOCKET sock, char *buf, int size)
{
 int i = 0;
 char c = '\0';
 int n;

 while ((i < size - 1) && (c != '\n'))
 {
  n = recv(sock, &c, 1, 0);
  /* DEBUG printf("%02X\n", c); */
  if (n > 0)
  {
   if (c == '\r')
   {
    n = recv(sock, &c, 1, MSG_PEEK);
    /* DEBUG printf("%02X\n", c); */
    if ((n > 0) && (c == '\n'))
     recv(sock, &c, 1, 0);
    else
     c = '\n';
   }
   buf[i] = c;
   i++;
  }
  else
   c = '\n';
 }
 buf[i] = '\0';
 
 return(i);
}

/**********************************************************************/
/* Return the informational HTTP headers about a file. */
/* Parameters: the socket to print the headers on
 *             the name of the file */
/**********************************************************************/
void headers(SOCKET client, const char *filename)
{
 char buf[1024];
 (void)filename;  /* could use filename to determine file type */

 strcpy_s(buf, 1024, "HTTP/1.0 200 OK\r\n");
 send(client, buf, strlen(buf), 0);
 strcpy_s(buf, 1024, SERVER_STRING);
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "Content-Type: text/html\r\n");
 send(client, buf, strlen(buf), 0);
 strcpy_s(buf, 1024, "\r\n");
 send(client, buf, strlen(buf), 0);
}

/**********************************************************************/
/* Give a client a 404 not found status message. */
/**********************************************************************/
void not_found(SOCKET client)
{
 char buf[1024];

 sprintf_s(buf, 1024, "HTTP/1.0 404 NOT FOUND\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, SERVER_STRING);
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "Content-Type: text/html\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "<HTML><TITLE>Not Found</TITLE>\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "<BODY><P>The server could not fulfill\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "your request because the resource specified\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "is unavailable or nonexistent.\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "</BODY></HTML>\r\n");
 send(client, buf, strlen(buf), 0);
}

/**********************************************************************/
/* Send a regular file to the client.  Use headers, and report
 * errors to client if they occur.
 * Parameters: a pointer to a file structure produced from the socket
 *              file descriptor
 *             the name of the file to serve */
/**********************************************************************/
void serve_file(SOCKET client, const char *filename)
{
 FILE *resource = NULL;
 char buf[1024];

 discardheaders(client);
 fopen_s(&resource, filename, "r");
 if (resource == NULL)
  not_found(client);
 else
 {
  headers(client, filename);
  cat(client, resource);
 }
 fclose(resource);
}


/**********************************************************************/
/* Send a regular file to the client.  Use headers, and report
 * errors to client if they occur.
 * Parameters: a pointer to a file structure produced from the socket
 *              file descriptor
 *             the name of the file to serve */
/**********************************************************************/
void discardheaders(SOCKET client)
{
	char buf[1024];
	int numchars = 1;
	while ((numchars > 0) && strcmp("\n", buf))  /* read & discard headers */
		numchars = get_line(client, buf, sizeof(buf));
}

/**********************************************************************/
/* This function starts the process of listening for web connections
 * on a specified port.  If the port is 0, then dynamically allocate a
 * port and modify the original port variable to reflect the actual
 * port.
 * Parameters: pointer to variable containing the port to connect on
 * Returns: the socket */
/**********************************************************************/
SOCKET startup(u_short *port)
{
 SOCKET httpd = 0;
 struct sockaddr_in name;

 httpd = socket(AF_INET, SOCK_STREAM, 0);
 if (httpd == INVALID_SOCKET)
  error_die("socket");
 memset(&name, 0, sizeof(name));
 name.sin_family = AF_INET;
 name.sin_port = htons(*port);
 name.sin_addr.s_addr = inet_addr("127.0.0.1");
 if (bind(httpd, (struct sockaddr *)&name, sizeof(name)) < 0)
  error_die("bind");
 if (*port == 0)  /* if dynamically allocating a port */
 {
  int namelen = sizeof(name);
  if (getsockname(httpd, (struct sockaddr *)&name, &namelen) == -1)
   error_die("getsockname");
  *port = ntohs(name.sin_port);
 }
 if (listen(httpd, 5) < 0)
  error_die("listen");
 return(httpd);
}

/**********************************************************************/
/* Inform the client that the requested web method has not been
 * implemented.
 * Parameter: the client socket */
/**********************************************************************/
void unimplemented(SOCKET client)
{
 char buf[1024];

 sprintf_s(buf, 1024, "HTTP/1.0 501 Method Not Implemented\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, SERVER_STRING);
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "Content-Type: text/html\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "<HTML><HEAD><TITLE>Method Not Implemented\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "</TITLE></HEAD>\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "<BODY><P>HTTP request method not supported.\r\n");
 send(client, buf, strlen(buf), 0);
 sprintf_s(buf, 1024, "</BODY></HTML>\r\n");
 send(client, buf, strlen(buf), 0);
}

/**********************************************************************/
int main(void)
{
 SOCKET server_sock = INVALID_SOCKET;
 u_short port = 0;
 SOCKET client_sock = -1;
 struct sockaddr_in client_name;
 int client_name_len = sizeof(client_name);

 // 初始化socket
 WSADATA wsaData;
 WSAStartup(MAKEWORD(2,2), &wsaData);

 server_sock = startup(&port);
 printf("httpd running on port %d\n", port);

 while (1)
 {
  client_sock = accept(server_sock,
                       (struct sockaddr *)&client_name,
                       &client_name_len);
  if (client_sock == INVALID_SOCKET)
   error_die("accept");
  accept_request(client_sock);		// 单线程模式
 }

 closesocket(server_sock);

 WSACleanup();
 return(0);
}