read_write.c

ssl的客户端和服务端源代码

#include "common.h"

/* Read from the keyboard and write to the server
   Read from the server and write to the keyboard

   we use select() to multiplex
*/
void read_write(ssl,sock)
  SSL *ssl;
  {
    int width;
    int r,c2sl=0,c2s_offset=0;
    fd_set readfds,writefds;
    int shutdown_wait=0;
    char c2s[BUFSIZZ],s2c[BUFSIZZ];
    int ofcmode;
    
    /*First we make the socket nonblocking*/
    ofcmode=fcntl(sock,F_GETFL,0);
    ofcmode|=O_NDELAY;
    if(fcntl(sock,F_SETFL,ofcmode))
      err_exit("Couldn't make socket nonblocking");
    

    width=sock+1;
    
    while(1){
      FD_ZERO(&readfds);
      FD_ZERO(&writefds);

      FD_SET(sock,&readfds);

      /*If we've still got data to write then don't try to read*/
      if(c2sl)
        FD_SET(sock,&writefds);
      else
        FD_SET(fileno(stdin),&readfds);

      r=select(width,&readfds,&writefds,0,0);
      if(r==0)
        continue;

      /* Now check if there's data to read */
      if(FD_ISSET(sock,&readfds)){
        do {
          r=SSL_read(ssl,s2c,BUFSIZZ);
          
          switch(SSL_get_error(ssl,r)){
            case SSL_ERROR_NONE:
              fwrite(s2c,1,r,stdout);
              break;
            case SSL_ERROR_ZERO_RETURN:
              /* End of data */
              if(!shutdown_wait)
                SSL_shutdown(ssl);
              goto end;
              break;
            case SSL_ERROR_WANT_READ:
              break;
            default:
              berr_exit("SSL read problem");
          }
        } while (SSL_pending(ssl));
      }
      
      /* Check for input on the console*/
      if(FD_ISSET(fileno(stdin),&readfds)){
        c2sl=read(fileno(stdin),c2s,BUFSIZZ);
        if(c2sl==0){
          shutdown_wait=1;
          if(SSL_shutdown(ssl))
            return;
        }
        c2s_offset=0;
      }

      /* If we've got data to write then try to write it*/
      if(c2sl && FD_ISSET(sock,&writefds)){
        r=SSL_write(ssl,c2s+c2s_offset,c2sl);

        switch(SSL_get_error(ssl,r)){
          /* We wrote something*/
          case SSL_ERROR_NONE:
            c2sl-=r;
            c2s_offset+=r;
            break;
            
            /* We would have blocked */
          case SSL_ERROR_WANT_WRITE:
            break;

            /* Some other error */
          default:	      
            berr_exit("SSL write problem");
        }
      }

      
    }
  end:
    SSL_free(ssl);
    close(sock);
    return;
  }