print-atalk.c

来自「TCPDUMP的C语言源代码,是在数据链路层的应用」· C语言 代码 · 共 628 行 · 第 1/2 页

		/* length should be zero */
		if (length)
			(void)printf(" [len=%d]", length);

		/* there shouldn't be any control flags */
		if (ap->control & (atpXO|atpEOM|atpSTS)) {
			c = '[';
			if (ap->control & atpXO) {
				(void)printf("%cXO", c);
				c = ',';
			}
			if (ap->control & atpEOM) {
				(void)printf("%cEOM", c);
				c = ',';
			}
			if (ap->control & atpSTS) {
				(void)printf("%cSTS", c);
				c = ',';
			}
			(void)printf("]");
		}
		break;

	default:
		(void)printf(" atp-0x%x  %d (%d)", ap->control,
			     EXTRACT_16BITS(&ap->transID), length);
		break;
	}
	data = EXTRACT_32BITS(&ap->userData);
	if (data != 0)
		(void)printf(" 0x%x", data);
}

static void
atp_bitmap_print(register u_char bm)
{
	register char c;
	register int i;

	/*
	 * The '& 0xff' below is needed for compilers that want to sign
	 * extend a u_char, which is the case with the Ultrix compiler.
	 * (gcc is smart enough to eliminate it, at least on the Sparc).
	 */
	if ((bm + 1) & (bm & 0xff)) {
		c = '<';
		for (i = 0; bm; ++i) {
			if (bm & 1) {
				(void)printf("%c%d", c, i);
				c = ',';
			}
			bm >>= 1;
		}
		(void)printf(">");
	} else {
		for (i = 0; bm; ++i)
			bm >>= 1;
		if (i > 1)
			(void)printf("<0-%d>", i - 1);
		else
			(void)printf("<0>");
	}
}

static void
nbp_print(register const struct atNBP *np, u_int length, register u_short snet,
	  register u_char snode, register u_char skt)
{
	register const struct atNBPtuple *tp =
		(const struct atNBPtuple *)((u_char *)np + nbpHeaderSize);
	int i;
	const u_char *ep;

	if (length < nbpHeaderSize) {
		(void)printf(" truncated-nbp %d", length);
		return;
	}

	length -= nbpHeaderSize;
	if (length < 8) {
		/* must be room for at least one tuple */
		(void)printf(" truncated-nbp %d", length + nbpHeaderSize);
		return;
	}
	/* ep points to end of available data */
	ep = snapend;
	if ((const u_char *)tp > ep) {
		fputs(tstr, stdout);
		return;
	}
	switch (i = np->control & 0xf0) {

	case nbpBrRq:
	case nbpLkUp:
		(void)printf(i == nbpLkUp? " nbp-lkup %d:":" nbp-brRq %d:",
			     np->id);
		if ((const u_char *)(tp + 1) > ep) {
			fputs(tstr, stdout);
			return;
		}
		(void)nbp_name_print(tp, ep);
		/*
		 * look for anomalies: the spec says there can only
		 * be one tuple, the address must match the source
		 * address and the enumerator should be zero.
		 */
		if ((np->control & 0xf) != 1)
			(void)printf(" [ntup=%d]", np->control & 0xf);
		if (tp->enumerator)
			(void)printf(" [enum=%d]", tp->enumerator);
		if (EXTRACT_16BITS(&tp->net) != snet ||
		    tp->node != snode || tp->skt != skt)
			(void)printf(" [addr=%s.%d]",
			    ataddr_string(EXTRACT_16BITS(&tp->net),
			    tp->node), tp->skt);
		break;

	case nbpLkUpReply:
		(void)printf(" nbp-reply %d:", np->id);

		/* print each of the tuples in the reply */
		for (i = np->control & 0xf; --i >= 0 && tp; )
			tp = nbp_tuple_print(tp, ep, snet, snode, skt);
		break;

	default:
		(void)printf(" nbp-0x%x  %d (%d)", np->control, np->id,
				length);
		break;
	}
}

/* print a counted string */
static const char *
print_cstring(register const char *cp, register const u_char *ep)
{
	register u_int length;

	if (cp >= (const char *)ep) {
		fputs(tstr, stdout);
		return (0);
	}
	length = *cp++;

	/* Spec says string can be at most 32 bytes long */
	if (length > 32) {
		(void)printf("[len=%u]", length);
		return (0);
	}
	while ((int)--length >= 0) {
		if (cp >= (const char *)ep) {
			fputs(tstr, stdout);
			return (0);
		}
		putchar(*cp++);
	}
	return (cp);
}

static const struct atNBPtuple *
nbp_tuple_print(register const struct atNBPtuple *tp,
		register const u_char *ep,
		register u_short snet, register u_char snode,
		register u_char skt)
{
	register const struct atNBPtuple *tpn;

	if ((const u_char *)(tp + 1) > ep) {
		fputs(tstr, stdout);
		return 0;
	}
	tpn = nbp_name_print(tp, ep);

	/* if the enumerator isn't 1, print it */
	if (tp->enumerator != 1)
		(void)printf("(%d)", tp->enumerator);

	/* if the socket doesn't match the src socket, print it */
	if (tp->skt != skt)
		(void)printf(" %d", tp->skt);

	/* if the address doesn't match the src address, it's an anomaly */
	if (EXTRACT_16BITS(&tp->net) != snet || tp->node != snode)
		(void)printf(" [addr=%s]",
		    ataddr_string(EXTRACT_16BITS(&tp->net), tp->node));

	return (tpn);
}

static const struct atNBPtuple *
nbp_name_print(const struct atNBPtuple *tp, register const u_char *ep)
{
	register const char *cp = (const char *)tp + nbpTupleSize;

	putchar(' ');

	/* Object */
	putchar('"');
	if ((cp = print_cstring(cp, ep)) != NULL) {
		/* Type */
		putchar(':');
		if ((cp = print_cstring(cp, ep)) != NULL) {
			/* Zone */
			putchar('@');
			if ((cp = print_cstring(cp, ep)) != NULL)
				putchar('"');
		}
	}
	return ((const struct atNBPtuple *)cp);
}


#define HASHNAMESIZE 4096

struct hnamemem {
	int addr;
	char *name;
	struct hnamemem *nxt;
};

static struct hnamemem hnametable[HASHNAMESIZE];

static const char *
ataddr_string(u_short atnet, u_char athost)
{
	register struct hnamemem *tp, *tp2;
	register int i = (atnet << 8) | athost;
	char nambuf[MAXHOSTNAMELEN + 20];
	static int first = 1;
	FILE *fp;

	/*
	 * if this is the first call, see if there's an AppleTalk
	 * number to name map file.
	 */
	if (first && (first = 0, !nflag)
	    && (fp = fopen("/etc/atalk.names", "r"))) {
		char line[256];
		int i1, i2, i3;

		while (fgets(line, sizeof(line), fp)) {
			if (line[0] == '\n' || line[0] == 0 || line[0] == '#')
				continue;
			if (sscanf(line, "%d.%d.%d %256s", &i1, &i2, &i3,
				     nambuf) == 4)
				/* got a hostname. */
				i3 |= ((i1 << 8) | i2) << 8;
			else if (sscanf(line, "%d.%d %256s", &i1, &i2,
					nambuf) == 3)
				/* got a net name */
				i3 = (((i1 << 8) | i2) << 8) | 255;
			else
				continue;

			for (tp = &hnametable[i3 & (HASHNAMESIZE-1)];
			     tp->nxt; tp = tp->nxt)
				;
			tp->addr = i3;
			tp->nxt = newhnamemem();
			tp->name = strdup(nambuf);
		}
		fclose(fp);
	}

	for (tp = &hnametable[i & (HASHNAMESIZE-1)]; tp->nxt; tp = tp->nxt)
		if (tp->addr == i)
			return (tp->name);

	/* didn't have the node name -- see if we've got the net name */
	i |= 255;
	for (tp2 = &hnametable[i & (HASHNAMESIZE-1)]; tp2->nxt; tp2 = tp2->nxt)
		if (tp2->addr == i) {
			tp->addr = (atnet << 8) | athost;
			tp->nxt = newhnamemem();
			(void)snprintf(nambuf, sizeof(nambuf), "%s.%d",
			    tp2->name, athost);
			tp->name = strdup(nambuf);
			return (tp->name);
		}

	tp->addr = (atnet << 8) | athost;
	tp->nxt = newhnamemem();
	if (athost != 255)
		(void)snprintf(nambuf, sizeof(nambuf), "%d.%d.%d",
		    atnet >> 8, atnet & 0xff, athost);
	else
		(void)snprintf(nambuf, sizeof(nambuf), "%d.%d", atnet >> 8,
		    atnet & 0xff);
	tp->name = strdup(nambuf);

	return (tp->name);
}

static struct tok skt2str[] = {
	{ rtmpSkt,	"rtmp" },	/* routing table maintenance */
	{ nbpSkt,	"nis" },	/* name info socket */
	{ echoSkt,	"echo" },	/* AppleTalk echo protocol */
	{ zipSkt,	"zip" },	/* zone info protocol */
	{ 0,		NULL }
};

static const char *
ddpskt_string(register int skt)
{
	static char buf[8];

	if (nflag) {
		(void)snprintf(buf, sizeof(buf), "%d", skt);
		return (buf);
	}
	return (tok2str(skt2str, "%d", skt));
}