/*
** kernel/unicos6.c	Low level kernel access functions for Cray UNICOS 6
**
** This program is in the public domain and may be used freely by anyone
** who wants to. 
**
** Last update: 17 March 1993
**
** Please send bug fixes/bug reports to: Peter Eriksson <pen@lysator.liu.se>
*/

#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <nlist.h>
#include <pwd.h>
#include <signal.h>
#include <syslog.h>

#include "kvm.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>

#define IP_SECURITY

#include <sys/socketvar.h>

#define KERNEL

#include <sys/file.h>

#include <fcntl.h>

#include <sys/param.h>
#include <sys/sysmacros.h>

#include <sys/wait.h>
  
#undef KERNEL

#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>

#include <netinet/in_pcb.h>

#include <netinet/tcp.h>
#include <netinet/ip_var.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>

#include <arpa/inet.h>


#include "identd.h"
#include "error.h"


extern void *calloc();
extern void *malloc();


struct nlist nl[] =
{
#define N_TCB 0

   { "tcb" },
   { "" }
};

static kvm_t *kd;

static struct file *xfile;
static int nfile;

static struct inpcb tcb;


int k_open()
{
  /*
  ** Open the kernel memory device
  */
  if (!(kd = kvm_open(path_unix, path_kmem, NULL, O_RDONLY, NULL)))
    ERROR("main: kvm_open");
  
  /*
  ** Extract offsets to the needed variables in the kernel
  */
  if (kvm_nlist(kd, nl) != 0)
    ERROR("main: kvm_nlist");

  return 0;
}


/*
** Get a piece of kernel memory with error handling.
** Returns 1 if call succeeded, else 0 (zero).
*/
static int getbuf(addr, buf, len, what)
  long addr;
  char *buf;
  int len;
  char *what;
{
  if (kvm_read(kd, addr, buf, len) < 0)
  {
    if (syslog_flag)
      syslog(LOG_ERR, "getbuf: kvm_read(%08x, %d) - %s : %m",
	     addr, len, what);

    return 0;
  }
  
  return 1;
}



/*
** Traverse the inpcb list until a match is found.
** Returns NULL if no match.
*/
static struct socket *
    getlist(pcbp, faddr, fport, laddr, lport)
  struct inpcb *pcbp;
  struct in_addr *faddr;
  int fport;
  struct in_addr *laddr;
  int lport;
{
  struct inpcb *head;

  if (!pcbp)
    return NULL;

  
  head = pcbp->inp_prev;
  do 
  {
    if ( pcbp->inp_faddr.s_addr == faddr->s_addr &&
	 pcbp->inp_laddr.s_addr == laddr->s_addr &&
	 pcbp->inp_fport        == fport &&
	 pcbp->inp_lport        == lport )
      return pcbp->inp_socket;

  } while (wtob((long) pcbp->inp_next) != (long) head &&
	   getbuf(wtob((long) pcbp->inp_next), /* inp_next is a word ptr */
		  pcbp,
		  sizeof(struct inpcb),
		  "tcblist"));

  return NULL;
}



/*
** Return the user number for the connection owner
*/
int k_getuid(faddr, fport, laddr, lport, uid)
  struct in_addr *faddr;
  int fport;
  struct in_addr *laddr;
  int lport;
  int *uid;
{
  long addr;
  struct socket *sockp;
  int i;
  struct socket sockbuf;
  
  /* -------------------- TCP PCB LIST -------------------- */
  if (!getbuf(nl[N_TCB].n_value, &tcb, sizeof(tcb), "tcb"))
    return -1;
  
  tcb.inp_prev = (struct inpcb *) nl[N_TCB].n_value;
  sockp = getlist(&tcb, faddr, fport, laddr, lport);
  
  if (!sockp)
    return -1;

  /*
    Creator of socket's uid is stored in the socket structure!!!
    No need to walk the file table...
  */
  if(!getbuf(wtob(sockp), &sockbuf, sizeof(sockbuf), "socket"))
       return -1;
  *uid = sockbuf.so_uid;
  return 0;
}