#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <strings.h>
#include <sys/wait.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include "utils.h"
#include "ctype.h"
#include "username.h"

extern char **argvec;

#define IDENTD_PORT 113

#if defined(USERNAMES)
#if !defined(SYNC_USERNAMES)
static
#endif
const char *run_identd(const struct sockaddr_in *lcl, const struct sockaddr_in *rem)
{
 struct sockaddr_in sin;
 int s;
 static char buf[10240];
 int r;
 char *bp;
 int l;
 fd_set fds;
 fd_set tfds;
 struct timeval end;
 struct timeval d;

 s = socket(AF_INET,SOCK_STREAM,0);
 if (s < 0)
  { sprintf(&buf[0],"(socket: %s)",strerror(errno));
    return(&buf[0]);
  }
 bzero(&sin,sizeof(sin));
 sin.sin_family = AF_INET;
 sin.sin_addr = lcl->sin_addr;
 sin.sin_port = 0;
 if (bind(s,(struct sockaddr *)&sin,sizeof(sin)) < 0)
  { sprintf(&buf[0],"(bind: %s)",strerror(errno));
    close(s);
    return(&buf[0]);
  }
 bzero(&sin,sizeof(sin));
 sin.sin_family = AF_INET;
 sin.sin_addr = rem->sin_addr;
 sin.sin_port = htons(IDENTD_PORT);
 if (connect(s,(struct sockaddr *)&sin,sizeof(sin)) < 0)
  { sprintf(&buf[0],"(connect: %s)",strerror(errno));
    close(s);
    return(&buf[0]);
  }
 sprintf(&buf[0],"%hu,%hu\r\n",ntohs(rem->sin_port),ntohs(lcl->sin_port));
 write(s,&buf[0],strlen(&buf[0]));
 shutdown(s,1);
 bp = &buf[0];
 l = sizeof(buf) - 1;
 gettimeofday(&end,0);
 end.tv_sec += 60;
 FD_ZERO(&tfds);
 FD_SET(s,&tfds);
 while (l > 0)
  { gettimeofday(&d,0);
    if (d.tv_sec > end.tv_sec)
     { if (l < 16) bp -= 16;
       strcpy(bp,"(timeout)");
       close(s);
       return(&buf[0]);
     }
    d.tv_sec = end.tv_sec - d.tv_sec;
    d.tv_usec = 999999 - d.tv_usec;
    fds = tfds;
    r = select(s+1,&fds,0,0,&d);
    if (r < 0)
     { if (errno == EINTR) continue;
       sprintf(&buf[0],"(select: %s)",strerror(errno));
       close(s);
       return(&buf[0]);
     }
    if ((r > 0) && FD_ISSET(s,&fds))
     { r = read(s,bp,l);
       if (r < 0)
	{ sprintf(&buf[0],"(read: %s)",strerror(errno));
	  close(s);
	  return(&buf[0]);
	}
       if (r == 0) break;
       bp += r;
       l -= r;
     }
  }
 close(s);
 r = bp - &buf[0];
 if ((r > 0) && (bp[-1] == '\n'))
  { r --;
    bp --;
  }
 if ((r > 0) && (bp[-1] == '\r'))
  { r --;
    bp --;
  }
 l = bp - &buf[0];
 *bp = '\0';
 l = 0;
 for (bp=&buf[0];*bp;bp++)
  { if ( (*(unsigned char *)bp < 32) ||
	 ( (*(unsigned char *)bp >= 127) &&
	   (*(unsigned char *)bp < 160) ) )
     { l --;
     }
    else if (l != 0)
     { bp[l] = *bp;
     }
  }
 if (l != 0) bp[l] = '\0';
 l = (bp+l) - &buf[0];
 bp = index(&buf[0],':');
 if (! bp)
  { int i;
    fprintf(stderr,"no colon 1:");
    for (i=0;i<l;i++)
     { if (i > 32)
	{ fprintf(stderr," ...");
	  break;
	}
       fprintf(stderr," %02x",((unsigned char *)&buf[0])[i]);
     }
    fprintf(stderr,"\n");
    l = strlen(&buf[0]);
    if (l > 100) l = 100;
    bcopy(&buf[0],&buf[20],l);
    bcopy("(error: no colon 1: ",&buf[0],20);
    buf[l+20] = ')';
    buf[l+21] = '\0';
    return(&buf[0]);
  }
 do bp++; while (*bp && Cisspace(*bp));
 if (!bcmp(bp,"USERID",6))
  { bp = index(bp+6,':');
    if (! bp) return("(error: no colon after USERID)");
    bp = index(bp+1,':');
    if (! bp) return("(error: no colon after OS)");
    return(bp+1);
  }
 else if (!bcmp(bp,"ERROR",5))
  { return(bp);
  }
 return("(error: neither USERID nor ERROR)");
}
#endif

#if defined(USERNAMES) && !defined(SYNC_USERNAMES)
int username_fd;
void fork_username_process(void)
{
 int p[2];
 int pid;
 int npend;
 int pend[1024];
 int i;
 int j;
 fd_set rfds;

 socketpair(AF_UNIX,SOCK_STREAM,0,&p[0]);
 pid = fork();
 if (pid)
  { username_fd = p[0];
    close(p[1]);
    return;
  }
 signal(SIGINT,SIG_IGN);
 username_fd = p[1];
 close(p[0]);
 for (i=getdtablesize()-1;i>=0;i--)
  { if ((i != username_fd) && (i != 2)) close(i);
  }
 npend = 0;
 while (1)
  { while (1)
     { pid = wait3(0,WNOHANG,0);
       if (pid <= 0) break;
     }
    FD_ZERO(&rfds);
    FD_SET(username_fd,&rfds);
    j = 0;
    for (i=0;i<npend;i++)
     { if (pend[i] >= 0)
	{ FD_SET(pend[i],&rfds);
	  if (j != i) pend[j] = pend[i];
	  j ++;
	}
     }
    npend = j;
    i = select(FD_SETSIZE,&rfds,0,0,0);
    if (i < 0)
     { if (errno == EINTR) continue;
       fprintf(stderr,"%s: select: %s\n",argvec[0],strerror(errno));
       exit(0);
     }
    if (FD_ISSET(username_fd,&rfds))
     { struct sockaddr_in sin[2];
       if (Read(username_fd,&sin[0],sizeof(sin)) < 0) exit(0);
       socketpair(AF_UNIX,SOCK_STREAM,0,&p[0]);
       pend[npend++] = p[0];
       pid = fork();
       if (pid == 0)
	{ const char *s;
	  int n;
	  unsigned char len;
	  close(username_fd);
	  for (i=npend-1;i>=0;i--) close(pend[i]);
	  s = run_identd(&sin[0],&sin[1]);
	  n = strlen(s);
	  len = (n > 255) ? 255 : n;
	  write(p[1],&sin[0],sizeof(sin));
	  write(p[1],&len,1);
	  write(p[1],s,len);
	  exit(0);
	}
       close(p[1]);
       continue;
     }
    for (i=npend-1;i>=0;i--)
     { if (FD_ISSET(pend[i],&rfds))
#define SINS sizeof(struct sockaddr_in [2])
	{ unsigned char buf[SINS+1+255];
	  if ( (Read(pend[i],&buf[0],SINS+1) == 0) &&
	       (Read(pend[i],&buf[SINS+1],buf[SINS]) == 0) )
	   { write(username_fd,&buf[0],SINS+1+buf[SINS]);
	   }
#undef SINS
	  close(pend[i]);
	  pend[i] = -1;
	}
     }
  }
}
#endif