udp.c

非常不错的网管开发包

    /*
     *        Get the UDP statistics from the kernel...
     */

    auto_nlist(UDPSTAT_SYMBOL, (char *)&udpstat, sizeof (udpstat));
    auto_nlist(MIB_UDPCOUNTER_SYMBOL, (char *)&MIB_udpcounter,
	(MIB_udpMAXCTR+1)*sizeof (counter));

    switch (vp->magic){
	case UDPINDATAGRAMS:
	    long_return = MIB_udpcounter[1];
	    return (u_char *) &long_return;
	case UDPNOPORTS:
	    long_return = MIB_udpcounter[2];
	    return (u_char *) &long_return;
	case UDPOUTDATAGRAMS:
	    long_return = MIB_udpcounter[3];
	    return (u_char *) &long_return;
	case UDPINERRORS:
	    long_return = udpstat.udps_hdrops + udpstat.udps_badsum +
#ifdef STRUCT_UDPSTAT_HAS_UDPS_DISCARD
                      + udpstat.udps_discard +
#endif
			  udpstat.udps_badlen;
	    return (u_char *) &long_return;

	default:
	    DEBUGMSGTL(("snmpd", "unknown sub-id %d in var_udp\n", vp->magic));
    }
    return NULL;
}

#endif /* hpux */



u_char *
var_udpEntry(struct variable *vp,
	     oid *name,
	     size_t *length,
	     int exact,
	     size_t *var_len,
	     WriteMethod **write_method)
{
    int i;
    oid newname[MAX_OID_LEN], lowest[MAX_OID_LEN], *op;
    u_char *cp;
    int LowState;
    static struct inpcb inpcb, Lowinpcb;

    memcpy( (char *)newname,(char *)vp->name, (int)vp->namelen * sizeof(oid));
		/* find the "next" pseudo-connection */
Again:
LowState = -1;		/* UDP doesn't have 'State', but it's a useful flag */
	UDP_Scan_Init();
	for (;;) {
	    if ((i = UDP_Scan_Next(&inpcb)) < 0) goto Again;
	    if (i == 0) break;	    /* Done */
	    cp = (u_char *)&inpcb.inp_laddr.s_addr;
	    op = newname + 10;
	    *op++ = *cp++;
	    *op++ = *cp++;
	    *op++ = *cp++;
	    *op++ = *cp++;
	    
	    newname[14] = ntohs(inpcb.inp_lport);

	    if (exact){
		if (snmp_oid_compare(newname, 15, name, *length) == 0){
		    memcpy( (char *)lowest,(char *)newname, 15 * sizeof(oid));
		    LowState = 0;
		    Lowinpcb = inpcb;
		    break;  /* no need to search further */
		}
	    } else {
		if ((snmp_oid_compare(newname, 15, name, *length) > 0) &&
		     ((LowState < 0) || (snmp_oid_compare(newname, 15, lowest, 15) < 0))){
		    /*
		     * if new one is greater than input and closer to input than
		     * previous lowest, save this one as the "next" one.
		     */
		    memcpy( (char *)lowest,(char *)newname, 15 * sizeof(oid));
		    LowState = 0;
		    Lowinpcb = inpcb;
		}
	    }
	}
	if (LowState < 0) return(NULL);
	memcpy( (char *)name,(char *)lowest, ((int)vp->namelen + 10) * sizeof(oid));
	*length = vp->namelen + 5;
	*write_method = 0;
	*var_len = sizeof(long);
	switch (vp->magic) {
	    case UDPLOCALADDRESS:
		return (u_char *) &Lowinpcb.inp_laddr.s_addr;
	    case UDPLOCALPORT:
		long_return = ntohs(Lowinpcb.inp_lport);
		return (u_char *) &long_return;
	    default:
		DEBUGMSGTL(("snmpd", "unknown sub-id %d in var_udpEntry\n", vp->magic));
	}
    return  NULL;
}

#else /* solaris2 - udp */

u_char *
var_udp(struct variable *vp,
	oid *name,
	size_t *length,
	int exact,
	size_t *var_len,
	WriteMethod **write_method)
{
    mib2_udp_t udpstat;
    mib2_ip_t ipstat;
    u_char *ret = (u_char *)&long_return;	/* Successful completion */

    if (header_udp(vp, name, length, exact, var_len, write_method) == MATCH_FAILED )
	return NULL;


    /*
     *	Get the UDP statistics from the kernel...
     */
    if (getMibstat(MIB_UDP, &udpstat, sizeof(mib2_udp_t), GET_FIRST, &Get_everything, NULL) < 0)
      return (NULL);		/* Things are ugly ... */

    switch (vp->magic){
	case UDPNOPORTS:
		if (getMibstat(MIB_IP, &ipstat, sizeof(mib2_ip_t), GET_FIRST, &Get_everything, NULL) < 0)
		  return (NULL);		/* Things are ugly ... */
		long_return = ipstat.udpNoPorts;
		break;
	case UDPINDATAGRAMS:
      		long_return = udpstat.udpInDatagrams;
      		break;
	case UDPOUTDATAGRAMS:
      		long_return = udpstat.udpOutDatagrams;
      		break;
	case UDPINERRORS:
      		long_return = udpstat.udpInErrors;
      		break;
	default:
		ret = NULL;
		DEBUGMSGTL(("snmpd", "unknown sub-id %d in var_udp\n", vp->magic));
    }
    return (ret);
}

u_char *
var_udpEntry(struct variable *vp,
	     oid *name,
	     size_t *length,
	     int exact,
	     size_t *var_len,
	     WriteMethod **write_method)
{
    return NULL;
}
#endif /* solaris2 - udp */


	/*********************
	 *
	 *  Internal implementation functions
	 *
	 *********************/

#ifdef linux
static struct inpcb *udp_inpcb_list;
#endif

#ifndef solaris2
static struct inpcb udp_inpcb, *udp_prev;
#ifdef PCB_TABLE
static struct inpcb *udp_head, *udp_next;
#endif
#if defined(CAN_USE_SYSCTL) && defined(UDPCTL_PCBLIST)
static char *udpcb_buf = NULL;
static struct xinpgen *xig = NULL;
#endif /* !defined(CAN_USE_SYSCTL) || !define(UDPCTL_PCBLIST) */


static void UDP_Scan_Init(void)
{
#if !defined(CAN_USE_SYSCTL) || !defined(UDPCTL_PCBLIST)
#ifdef PCB_TABLE
    struct inpcbtable table;
#endif
#ifndef linux
#ifdef PCB_TABLE
    auto_nlist(UDB_SYMBOL, (char *)&table, sizeof(table));
    udp_next = table.inpt_queue.cqh_first;
    udp_head = udp_prev = (struct inpcb *)&((struct inpcbtable *)auto_nlist_value(UDB_SYMBOL))->inpt_queue.cqh_first;
#else
    auto_nlist(UDB_SYMBOL, (char *)&udp_inpcb, sizeof(udp_inpcb));
#if !(defined(freebsd2) || defined(netbsd1) || defined(openbsd2))
    udp_prev = (struct inpcb *) auto_nlist_value(UDB_SYMBOL);
#endif
#endif
#else /* linux */
    FILE *in;
    char line [256];
    struct inpcb **pp;
    struct timeval now;
    static unsigned long Time_Of_Last_Reload = 0;

    /*
     * save some cpu-cycles, and reload after 5 secs...
     */
    gettimeofday (&now, (struct timezone *) 0);
    if (Time_Of_Last_Reload + 5 > now.tv_sec)
      {
	udp_prev = udp_inpcb_list;
	return;
      }
    Time_Of_Last_Reload = now.tv_sec;


    if (! (in = fopen ("/proc/net/udp", "r")))
      {
 snmp_log(LOG_ERR, "snmpd: cannot open /proc/net/udp ...\n");
	udp_prev = 0;
	return;
      }

    /* free old chain: */
    while (udp_inpcb_list)
      {
	struct inpcb *p = udp_inpcb_list;
	udp_inpcb_list = udp_inpcb_list->inp_next;
	free (p);
      }

    /* scan proc-file and append: */

    pp = &udp_inpcb_list;
    
    while (line == fgets (line, sizeof(line), in))
      {
	struct inpcb pcb, *nnew;
	unsigned int state, lport;

	if (3 != sscanf (line, "%*d: %x:%x %*x:%*x %x", 
			 &pcb.inp_laddr.s_addr, &lport, &state))
	  continue;

	if (state != 7)		/* fix me:  UDP_LISTEN ??? */
	  continue;

	pcb.inp_lport = htons ((unsigned short) (lport));
	pcb.inp_fport = htons (pcb.inp_fport);

	nnew = (struct inpcb *) malloc (sizeof (struct inpcb));
	if (nnew == NULL) break;
	*nnew = pcb;
	nnew->inp_next = 0;

	*pp = nnew;
	pp = & nnew->inp_next;
      }

    fclose (in);

    /* first entry to go: */
    udp_prev = udp_inpcb_list;
#endif /*linux */
#else /*  !defined(CAN_USE_SYSCTL) || !defined(UDPCTL_PCBLIST) */
    {
	size_t len;
	int cc;
	int sname[] = { CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_PCBLIST };

	if (udpcb_buf) {
	    free(udpcb_buf);
	    udpcb_buf = NULL;
	}
	xig = NULL;

	len = 0;
	if (sysctl(sname, 4, 0, &len, 0, 0) < 0) {
	    return;
	}
	if ((udpcb_buf = malloc(len)) == NULL) {
	    return;
	}
	if (sysctl(sname, 4, udpcb_buf, &len, 0, 0) < 0) {
	    free(udpcb_buf);
	    udpcb_buf = NULL;
	    return;
	}

	xig = (struct xinpgen *)udpcb_buf;
	xig = (struct xinpgen *)((char *)xig + xig->xig_len);
	return;
    }
#endif /*  !defined(CAN_USE_SYSCTL) || !defined(UDPCTL_PCBLIST) */
}

static int UDP_Scan_Next(struct inpcb *RetInPcb)
{
#if !defined(CAN_USE_SYSCTL) || !defined(UDPCTL_PCBLIST)
	register struct inpcb *next;

#ifndef linux
#ifdef PCB_TABLE
	if (udp_next == udp_head) return 0;
#else
	if ((udp_inpcb.INP_NEXT_SYMBOL == NULL) ||
	    (udp_inpcb.INP_NEXT_SYMBOL ==
             (struct inpcb *) auto_nlist_value(UDB_SYMBOL))) {
	    return(0);	    /* "EOF" */
	}
#endif

#ifdef PCB_TABLE
	klookup((unsigned long)udp_next, (char *)&udp_inpcb, sizeof(udp_inpcb));	udp_next = udp_inpcb.inp_queue.cqe_next;
#else
        next = udp_inpcb.INP_NEXT_SYMBOL;

	klookup((unsigned long)next, (char *)&udp_inpcb, sizeof (udp_inpcb));
#if !(defined(netbsd1) || defined(freebsd2) || defined(linux) || defined(openbsd2))
	if (udp_inpcb.INP_PREV_SYMBOL != udp_prev)	   /* ??? */
          return(-1); /* "FAILURE" */
#endif
#endif
	*RetInPcb = udp_inpcb;
#if !(defined(netbsd1) || defined(freebsd2) || defined(openbsd2))
	udp_prev = next;
#endif
#else /* linux */
	if (!udp_prev) return 0;

	udp_inpcb = *udp_prev;
	next = udp_inpcb.inp_next;
	*RetInPcb = udp_inpcb;
	udp_prev = next;
#endif /* linux */
#else /*  !defined(CAN_USE_SYSCTL) || !defined(UDPCTL_PCBLIST) */
	/* Are we done? */
	if ((xig == NULL) ||
	    (xig->xig_len <= sizeof(struct xinpgen)))
	    return(0);  
	    
	*RetInPcb = ((struct xinpcb *)xig)->xi_inp;
	
	/* Prepare for Next read */
	xig = (struct xinpgen *)((char *)xig + xig->xig_len);
#endif /*  !defined(CAN_USE_SYSCTL) || !defined(UDPCTL_PCBLIST) */
	return(1);	/* "OK" */
}
#endif /* solaris2 */

#ifdef linux

static void
linux_read_udp_stat (struct udp_mib *udpstat)
{
  FILE *in = fopen ("/proc/net/snmp", "r");
  char line [1024];

  memset ((char *) udpstat,(0), sizeof (*udpstat));

  if (! in)
    return;

  while (line == fgets (line, sizeof(line), in))
    {
      if (4 == sscanf (line, "Udp: %lu %lu %lu %lu\n",
			&udpstat->UdpInDatagrams, &udpstat->UdpNoPorts,
			&udpstat->UdpInErrors, &udpstat->UdpOutDatagrams))
	break;
    }
  fclose (in);
}

#endif /* linux */