mtrace.c

mtrace源码

#define STATS_MISSING(x)	((x) == 0xFFFFFFFF)

    if (!STATS_MISSING(s->tr_vifout) && !STATS_MISSING(r->tr_vifout))
	    vhave |= OUTS;
    if (STATS_MISSING(s->tr_pktcnt) || STATS_MISSING(r->tr_pktcnt))
	    gmissing |= OUTS;
    if (!(*rst & BUG_NOPRINT))
	    ghave |= OUTS;

    if (have_next) {
	--r,  --s,  --rst;
	if (!STATS_MISSING(s->tr_vifin) && !STATS_MISSING(r->tr_vifin))
	    vhave |= INS;
	if (STATS_MISSING(s->tr_pktcnt) || STATS_MISSING(r->tr_pktcnt))
	    gmissing |= INS;
	if (!(*rst & BUG_NOPRINT))
	    ghave |= INS;
    }

    /*
     * Stats can be missing for any number of reasons:
     * - The hop may not be capable of collecting stats
     * - Traffic may be getting dropped at the previous hop
     *   and so this hop may not have any state
     *
     * We need a stronger heuristic to tell between these
     * two cases; in case 1 we don't want to print the stats
     * and in case 2 we want to print 100% loss.  We used to
     * err on the side of not printing, which is less useful
     * than printing 100% loss and dealing with it.
     */
#if 0
    /*
     * If both hops report as missing, then it's likely that there's just
     * no traffic flowing.
     *
     * If just one hop is missing, then we really don't have it.
     */
    if (gmissing != BOTH)
	ghave &= ~gmissing;
#endif

    whochar = have_next ? '^' : ' ';
    switch (vhave) {
      case BOTH:
	v_lost = v_out - (ntohl(s->tr_vifin) - ntohl(r->tr_vifin));
	if (v_out) v_pct = v_lost * 100 / v_out;
	else v_pct = 0;
	if (-20 < v_pct && v_pct < 101 && v_out > 10)
	  sprintf(v_str, "%3d%%", v_pct);
	else if (v_pct < -900 && v_out > 10)
	  sprintf(v_str, "%3dx", (int)(-v_pct / 100. + 1.));
	else if (v_pct <= -20 && v_out > 10)
	  sprintf(v_str, "%1.1fx", -v_pct / 100. + 1.);
	else
	  memcpy(v_str, " -- ", 5);

	if (tunstats)
	    printf("%6d/%-5d=%s", v_lost, v_out, v_str);
	else
	    printf("   ");
	printf("%4d pps", v_pps);
	if (v_pps && badtime)
	    printf("?");

	break;

      case INS:
	v_out = ntohl(s->tr_vifin) - ntohl(r->tr_vifin);
	v_pps = v_out / timediff;
	whochar = 'v';
	/* Fall through */

      case OUTS:
	if (tunstats)
	    printf("      %c%-5d     ", whochar, v_out);
	else
	    printf("  %c", whochar);
	printf("%4d pps", v_pps);
	if (v_pps && badtime)
	    printf("?");

	break;

      case NEITHER:
	if (ghave != NEITHER)
	    if (tunstats)
		printf("                         ");
	    else
		printf("           ");

	break;
    }

    whochar = have_next ? '^' : ' ';
    switch (ghave) {
      case BOTH:
	g_lost = g_out - (ntohl(s->tr_pktcnt) - ntohl(r->tr_pktcnt));
	if (g_out) g_pct = g_lost * 100 / g_out;
	else g_pct = 0;
	if (-20 < g_pct && g_pct < 101 && g_out > 10)
	  sprintf(g_str, "%3d%%", g_pct);
	else if (g_pct < -900 && g_out > 10)
	  sprintf(g_str, "%3dx", (int)(-g_pct / 100. + 1.));
	else if (g_pct <= -20 && g_out > 10)
	  sprintf(g_str, "%1.1fx", -g_pct / 100. + 1.);
	else
	  memcpy(g_str, " -- ", 5);

	printf("%s%6d/%-5d=%s%4d pps",
	       tunstats ? "" : "   ", g_lost, g_out, g_str, g_pps);
	if (g_pps && badtime)
	    printf("?");
	printf("\n");
	break;

#if 0
      case INS:
	g_out = ntohl(s->tr_pktcnt) - ntohl(r->tr_pktcnt);
	g_pps = g_out / timediff;
	whochar = 'v';
	/* Fall through */
#endif

      case OUTS:
	printf("%s     ?/%-5d     %4d pps",
	       tunstats ? "" : "   ", g_out, g_pps);
	if (badtime)
	    printf("?");
	printf("\n");
	break;

      case INS:
      case NEITHER:
	printf("\n");
	break;
    }


    if (debug > 2) {
	printf("\t\t\t\tv_in: %ld ", ntohl(s->tr_vifin));
	printf("v_out: %ld ", ntohl(s->tr_vifout));
	printf("pkts: %ld\n", ntohl(s->tr_pktcnt));
	printf("\t\t\t\tv_in: %ld ", ntohl(r->tr_vifin));
	printf("v_out: %ld ", ntohl(r->tr_vifout));
	printf("pkts: %ld\n", ntohl(r->tr_pktcnt));
	printf("\t\t\t\tv_in: %ld ",ntohl(s->tr_vifin)-ntohl(r->tr_vifin));
	printf("v_out: %ld ", ntohl(s->tr_vifout) - ntohl(r->tr_vifout));
	printf("pkts: %ld ", ntohl(s->tr_pktcnt) - ntohl(r->tr_pktcnt));
	printf("time: %d\n", timediff);
	printf("\t\t\t\treset: %x hoptime: %lx\n", *rst, ntohl(s->tr_qarr));
    }
}

/*
 * A fixup to check if any pktcnt has been reset, and to fix the
 * byteorder bugs in mrouted 3.6 on little-endian machines.
 *
 * XXX Since periodic traffic sources are likely to have their
 *     pktcnt periodically reset, should we save old values when
 *     the reset occurs to keep slightly better statistics over
 *     the long term?  (e.g. SAP)
 */
void
fixup_stats(base, prev, new, bugs)
    struct resp_buf *base, *prev, *new;
    int *bugs;
{
    int rno = base->len;
    struct tr_resp *b = base->resps + rno;
    struct tr_resp *p = prev->resps + rno;
    struct tr_resp *n = new->resps + rno;
    int *r = bugs + rno;
    int res;
    int cleanup = 0;

    /* Check for byte-swappers.  Only check on the first trace,
     * since long-running traces can wrap around and falsely trigger. */
    while (--rno >= 0) {
#ifdef TEST_ONLY
	u_int32 nvifout = ntohl(n->tr_vifout);
	u_int32 pvifout = ntohl(p->tr_vifout);
#endif
	--n; --p; --b;
#ifdef TEST_ONLY	/*XXX this is still buggy, so disable it for release */
	if ((*r & BUG_SWAP) ||
	    ((base == prev) &&
	     (nvifout - pvifout) > (byteswap(nvifout) - byteswap(pvifout)))) {
	    if (1 || debug > 2) {
		printf("ip %s swaps; b %08x p %08x n %08x\n",
			inet_fmt(n->tr_inaddr, s1),
			ntohl(b->tr_vifout), pvifout, nvifout);
	    }
	    /* This host sends byteswapped reports; swap 'em */
	    if (!(*r & BUG_SWAP)) {
		*r |= BUG_SWAP;
		b->tr_qarr = byteswap(b->tr_qarr);
		b->tr_vifin = byteswap(b->tr_vifin);
		b->tr_vifout = byteswap(b->tr_vifout);
		b->tr_pktcnt = byteswap(b->tr_pktcnt);
	    }

	    n->tr_qarr = byteswap(n->tr_qarr);
	    n->tr_vifin = byteswap(n->tr_vifin);
	    n->tr_vifout = byteswap(n->tr_vifout);
	    n->tr_pktcnt = byteswap(n->tr_pktcnt);
	}
#endif
	/*
	 * A missing parenthesis in mrouted 3.5-3.8's prune.c
	 * causes extremely bogus time diff's.
	 * One half of the time calculation was
	 * inside an htonl() and one half wasn't.  Therefore, on
	 * a little-endian machine, both halves of the calculation
	 * would get added together in the little end.  Thus, the
	 * low-order 2 bytes are either 0000 (no overflow) or
	 * 0100 (overflow from the addition).
	 *
	 * Odds are against these particular bit patterns
	 * happening in both prev and new for actual time values.
	 */
	if ((*r & BUG_BOGUSTIME) || (((ntohl(n->tr_qarr) & 0xfeff) == 0x0000) &&
	    ((ntohl(p->tr_qarr) & 0xfeff) == 0x0000))) {
	    *r |= BUG_BOGUSTIME;
	    n->tr_qarr = new->rtime;
	    p->tr_qarr = prev->rtime;
	    b->tr_qarr = base->rtime;
	}
    }

    rno = base->len;
    b = base->resps + rno;
    p = prev->resps + rno;
    n = new->resps + rno;
    r = bugs + rno;

    while (--rno >= 0) {
	--n; --p; --b; --r;
	/*
	 * This hop has reset if:
	 * - There were statistics in the base AND previous pass, AND
	 *   - There are less packets this time than the first time and
	 *     we didn't reset last time, OR
	 *   - There are less packets this time than last time, OR
	 *   - There are no statistics on this pass.
	 *
	 * The "and we didn't reset last time" is necessary in the
	 * first branch of the OR because if the base is large and
	 * we reset last time but the constant-resetter-avoidance
	 * code kicked in so we delayed the copy of prev to base,
	 * new could still be below base so we trigger the
	 * constant-resetter code even though it was really only
	 * a single reset.
	 */
	res = ((b->tr_pktcnt != 0xFFFFFFFF) && (p->tr_pktcnt != 0xFFFFFFFF) &&
	       ((!(*r & BUG_RESET) && ntohl(n->tr_pktcnt) < ntohl(b->tr_pktcnt)) ||
	        (ntohl(n->tr_pktcnt) < ntohl(p->tr_pktcnt)) ||
		(n->tr_pktcnt == 0xFFFFFFFF)));
	if (debug > 2) {
    	    printf("\t\tip=%s, r=%d, res=%d\n", inet_fmt(b->tr_inaddr, s1), *r, res);
	    if (res)
		printf("\t\tbase=%ld, prev=%ld, new=%ld\n", ntohl(b->tr_pktcnt),
			    ntohl(p->tr_pktcnt), ntohl(n->tr_pktcnt));
	}
	if (*r & BUG_RESET) {
	    if (res || (*r & BUG_RESET2X)) {
		/*
		 * This router appears to be a 3.4 with that nasty ol'
		 * neighbor version bug, which causes it to constantly
		 * reset.  Just nuke the statistics for this node, and
		 * don't even bother giving it the benefit of the
		 * doubt from now on.
		 */
		p->tr_pktcnt = b->tr_pktcnt = n->tr_pktcnt;
		*r |= BUG_RESET2X;
	    } else {
		/*
		 * This is simply the situation that the original
		 * fixup_stats was meant to deal with -- that a
		 * 3.3 or 3.4 router deleted a cache entry while
		 * traffic was still active.
		 */
		*r &= ~BUG_RESET;
		cleanup = 1;
	    }
	} else
	    if (res)
		*r |= BUG_RESET;
    }

    if (cleanup == 0) return;

    /*
     * If some hop reset its counters and didn't continue to
     * reset, then we pretend that the previous
     * trace was the first one.
     */
    rno = base->len;
    b = base->resps + rno;
    p = prev->resps + rno;

    while (--rno >= 0) (--b)->tr_pktcnt = (--p)->tr_pktcnt;
    base->qtime = prev->qtime;
    base->rtime = prev->rtime;
}

/*
 * Check per-source losses along path and compare with threshold.
 */
int
check_thresh(thresh, base, prev, new)
    int thresh;
    struct resp_buf *base, *prev, *new;
{
    int rno = base->len - 1;
    struct tr_resp *b = base->resps + rno;
    struct tr_resp *p = prev->resps + rno;
    struct tr_resp *n = new->resps + rno;
    int g_out, g_lost;

    while (TRUE) {
	if ((n->tr_inaddr != b->tr_inaddr) ||
	    (n->tr_outaddr != b->tr_outaddr) ||
	    (n->tr_rmtaddr != b->tr_rmtaddr))
	  return 1;		/* Route changed */

	if (rno-- < 1) break;
    	g_out = ntohl(n->tr_pktcnt) - ntohl(p->tr_pktcnt);
	b--; n--; p--;
	g_lost = g_out - (ntohl(n->tr_pktcnt) - ntohl(p->tr_pktcnt));
	if (g_out && ((g_lost * 100 + (g_out >> 1))/ g_out) > thresh) {
	    return TRUE;
	}
    }
    return FALSE;
}

/*
 * Print responses with statistics for forward path (from src to dst)
 */
int
print_stats(base, prev, new, bugs, names)
    struct resp_buf *base, *prev, *new;
    int *bugs;
    char **names;
{
    int rtt, hop;
    char *ms;
    u_int32 smask;
    int rno = base->len - 1;
    struct tr_resp *b = base->resps + rno;
    struct tr_resp *p = prev->resps + rno;
    struct tr_resp *n = new->resps + rno;
    int *r = bugs + rno;
    u_long resptime = new->rtime;
    u_long qarrtime = ntohl(n->tr_qarr);
    u_int ttl = MaX(1, n->tr_fttl) + 1;
    int first = (base == prev);

    VAL_TO_MASK(smask, b->tr_smask);
    printf("  Source        Response Dest    ");
    if (tunstats)
	printf("Packet Statistics For     Only For Traffic\n");
    else
	printf("Overall     Packet Statistics For Traffic From\n");
    (void)inet_fmt(base->qhdr.tr_src, s1);
    printf("%-15s %-15s  ",
	   ((b->tr_inaddr & smask) == (base->qhdr.tr_src & smask)) ?
		s1 : "   * * *       ",
	   inet_fmt(base->qhdr.tr_raddr, s2));
    (void)inet_fmt(base->igmp.igmp_group.s_addr, s2);
    if (tunstats)
	printf("All Multicast Traffic     From %s\n", s1);
    else
	printf("Packet      %s To %s\n", s1, s2);
    rtt = t_diff(resptime, new->qtime);
    ms = scale(&rtt);
    printf("     %c       __/  rtt%5d%s    ",
	   (first && !verbose) ? 'v' : '|', rtt, ms);
    if (tunstats)
	printf("Lost/Sent = Pct  Rate       To %s\n", s2);
    else
	printf(" Rate       Lost/Sent = Pct  Rate\n");
    if (!first || verbose) {
	hop = t_diff(resptime, qarrtime);
	ms = scale(&hop);
	printf("     v      /     hop%5d%s    ", hop, ms);
	if (tunstats)
	    printf("---------------------     --------------------\n");
	else
	    printf("-------     ---------------------\n");
    }
    if ((b->tr_inaddr & smask) != (base->qhdr.tr_src & smask) &&
	    b->tr_rmtaddr != 0) {
	printf("%-15s %-14s is the previous hop\n", inet_fmt(b->tr_rmtaddr, s1),
		inet_name(b->tr_rmtaddr));
	printf("     v     ^\n");
    }
    if (debug > 2) {
	printf("\t\t\t\tv_in: %ld ", ntohl(n->tr_vifin));
	printf("v_out: %ld ", ntohl(n->tr_vifout));
	printf("pkts: %ld\n", ntohl(n->tr_pktcnt));
	printf("\t\t\t\tv_in: %ld ", ntohl(b->tr_vifin));
	printf("v_out: %ld ", ntohl(b->tr_vifout));
	printf("pkts: %ld\n", ntohl(b->tr_pktcnt));
	printf("\t\t\t\tv_in: %ld ", ntohl(n->tr_vifin) - ntohl(b->tr_vifin));
	printf("v_out: %ld ", ntohl(n->tr_vifout) - ntohl(b->tr_vifout));
	printf("pkts: %ld\n", ntohl(n->tr_pktcnt) - ntohl(b->tr_pktcnt));
	printf("\t\t\t\treset: %x hoptime: %lx\n", *r, ntohl(n->tr_qarr));
    }

    while (TRUE) {
	if ((n->tr_inaddr != b->tr_inaddr) ||
	    (n->tr_outaddr != b->tr_outaddr) ||
	    (n->tr_rmtaddr != b->tr_rmtaddr))
	  return 1;		/* Route changed */

	if ((n->tr_inaddr != n->tr_outaddr) && n->tr_inaddr)
	  printf("%-15s\n", inet_fmt(n->tr_inaddr, s1));
	printf("%-15s %-14s %s%s\n", inet_fmt(n->tr_outaddr, s1), names[rno],
		 flag_type(n->tr_rflags),
		 (*r & BUG_NOPRINT) ? " [reset counters]" : "");

	if (rno-- < 1) break;

	printf("     %c     ^      ttl%5d   ", (first && !verbose) ? 'v' : '|',
								ttl);
	stat_line(p, n, TRUE, r);
	if (!first || verbose) {
	    resptime = qarrtime;
	    qarrtime = ntohl((n-1)->tr_qarr);
	    hop = t_diff(resptime, qarrtime);
	    ms = scale(&hop);
	    printf("     v     |      hop%5d%s", hop, ms);
	    if (first)
		printf("\n");
	    else
		stat_line(b, n, TRUE, r);
	}

	--b, --p, --n, --r;
	ttl = MaX(ttl, MaX(1, n->tr_fttl) + base->len - rno);
    }
	   
    printf("     %c      \\__   ttl%5d   ", (first && !verbose) ? 'v' : '|',
							ttl);
    stat_line(p, n, FALSE, r);
    if (!first || verbose) {
	hop = t_diff(qarrtime, new->qtime);
	ms = scale(&hop);
	printf("     v         \\  hop%5d%s", hop, ms);
	if (first)
	    printf("\n");
	else
	    stat_line(b, n, FALSE, r);
    }
    printf("%-15s %s\n", inet_fmt(base->qhdr.tr_dst, s1),
			!passive ? inet_fmt(lcl_addr, s2) : "   * * *       ");
    printf("  Receiver      Query Source\n\n");
    return 0;
}

/*
 * Determine whether or not the path has changed.
 */
int
path_changed(base, new)
    struct resp_buf *base, *new;
{
    int r