print-bgp.c

Windump3.6.2源代码

			case BGP_COMMUNITY_NO_EXPORT:
				printf(" NO_EXPORT");
				break;
			case BGP_COMMUNITY_NO_ADVERT:
				printf(" NO_ADVERTISE");
				break;
			case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
				printf(" NO_EXPORT_SUBCONFED");
				break;
			default:
				printf(" (AS #%d value 0x%04x)",
					(comm >> 16) & 0xffff, comm & 0xffff);
				break;
			}
		}
		break;
	case BGPTYPE_MP_REACH_NLRI:
		af = ntohs(*(u_int16_t *)p);
		safi = p[2];
		if (safi >= 128)
			printf(" %s vendor specific,", af_name(af));
		else {
			printf(" %s %s,", af_name(af),
				bgp_attr_nlri_safi(safi));
		}
		p += 3;

		if (af == AFNUM_INET)
			;
#ifdef INET6
		else if (af == AFNUM_INET6)
			;
#endif
		else
			break;

		tlen = p[0];
		if (tlen) {
			printf(" nexthop");
			i = 0;
			while (i < tlen) {
				switch (af) {
				case AFNUM_INET:
					printf(" %s", getname(p + 1 + i));
					i += sizeof(struct in_addr);
					break;
#ifdef INET6
				case AFNUM_INET6:
					printf(" %s", getname6(p + 1 + i));
					i += sizeof(struct in6_addr);
					break;
#endif
				default:
					printf(" (unknown af)");
					i = tlen;	/*exit loop*/
					break;
				}
			}
			printf(",");
		}
		p += 1 + tlen;

		snpa = p[0];
		p++;
		if (snpa) {
			printf(" %u snpa", snpa);
			for (/*nothing*/; snpa > 0; snpa--) {
				printf("(%d bytes)", p[0]);
				p += p[0] + 1;
			}
			printf(",");
		}

		printf(" NLRI");
		while (len - (p - dat) > 0) {
			switch (af) {
			case AFNUM_INET:
				advance = decode_prefix4(p, buf, sizeof(buf));
				printf(" %s", buf);
				break;
#ifdef INET6
			case AFNUM_INET6:
				advance = decode_prefix6(p, buf, sizeof(buf));
				printf(" %s", buf);
				break;
#endif
			default:
				printf(" (unknown af)");
				advance = 0;
				p = dat + len;
				break;
			}

			p += advance;
		}

		break;

	case BGPTYPE_MP_UNREACH_NLRI:
		af = ntohs(*(u_int16_t *)p);
		safi = p[2];
		if (safi >= 128)
			printf(" %s vendor specific,", af_name(af));
		else {
			printf(" %s %s,", af_name(af),
				bgp_attr_nlri_safi(safi));
		}
		p += 3;

		printf(" Withdraw");
		while (len - (p - dat) > 0) {
			switch (af) {
			case AFNUM_INET:
				advance = decode_prefix4(p, buf, sizeof(buf));
				printf(" %s", buf);
				break;
#ifdef INET6
			case AFNUM_INET6:
				advance = decode_prefix6(p, buf, sizeof(buf));
				printf(" %s", buf);
				break;
#endif
			default:
				printf(" (unknown af)");
				advance = 0;
				p = dat + len;
				break;
			}

			p += advance;
		}
		break;
	default:
		break;
	}
}

static void
bgp_open_print(const u_char *dat, int length)
{
	struct bgp_open bgpo;
	struct bgp_opt bgpopt;
	int hlen;
	const u_char *opt;
	int i;

	TCHECK2(dat[0], sizeof(bgpo));
	memcpy(&bgpo, dat, sizeof(bgpo));
	hlen = ntohs(bgpo.bgpo_len);

	printf(": Version %d,", bgpo.bgpo_version);
	printf(" AS #%u,", ntohs(bgpo.bgpo_myas));
	printf(" Holdtime %u,", ntohs(bgpo.bgpo_holdtime));
	printf(" ID %s,", getname((u_char *)&bgpo.bgpo_id));
	printf(" Option length %u", bgpo.bgpo_optlen);

	/* ugly! */
	opt = &((struct bgp_open *)dat)->bgpo_optlen;
	opt++;

	for (i = 0; i < bgpo.bgpo_optlen; i++) {
		memcpy(&bgpopt, &opt[i], sizeof(bgpopt));
		if (i + 2 + bgpopt.bgpopt_len > bgpo.bgpo_optlen) {
			printf(" [|opt %d %d]", bgpopt.bgpopt_len, bgpopt.bgpopt_type);
			break;
		}

		printf(" (option %s, len=%d)", bgp_opttype(bgpopt.bgpopt_type),
			bgpopt.bgpopt_len);
		i += sizeof(bgpopt) + bgpopt.bgpopt_len;
	}
	return;
trunc:
	printf("[|BGP]");
}

static void
bgp_update_print(const u_char *dat, int length)
{
	struct bgp bgp;
	struct bgp_attr bgpa;
	int hlen;
	const u_char *p;
	int len;
	int i;
	int newline;

	TCHECK2(dat[0], sizeof(bgp));
	memcpy(&bgp, dat, sizeof(bgp));
	hlen = ntohs(bgp.bgp_len);
	p = dat + BGP_SIZE;	/*XXX*/
	printf(":");

	/* Unfeasible routes */
	len = EXTRACT_16BITS(p);
	if (len) {
		/*  Without keeping state from the original NLRI message,
		 *  it's not possible to tell if this a v4 or v6 route,
		 *  so only try to decode it if we're not v6 enabled.
	         */
#ifdef INET6
		printf(" (Withdrawn routes: %d bytes)", len);
#else	
		char buf[MAXHOSTNAMELEN + 100];

		TCHECK2(p[2], len);
 		i = 2;

		printf(" (Withdrawn routes:");
			
		while(i < 2 + len) {
			i += decode_prefix4(&p[i], buf, sizeof(buf));
			printf(" %s", buf);
		}
		printf(")\n");
#endif
	}
	p += 2 + len;

	TCHECK2(p[0], 2);
	len = EXTRACT_16BITS(p);
	if (len) {
		/* do something more useful!*/
		i = 2;
		printf(" (Path attributes:");	/* ) */
		newline = 0;
		while (i < 2 + len) {
			int alen, aoff;

			TCHECK2(p[i], sizeof(bgpa));
			memcpy(&bgpa, &p[i], sizeof(bgpa));
			alen = bgp_attr_len(&bgpa);
			aoff = bgp_attr_off(&bgpa);

			if (vflag && newline)
				printf("\n\t\t");
			else
				printf(" ");
			printf("(");		/* ) */
			printf("%s", bgp_attr_type(bgpa.bgpa_type));
			if (bgpa.bgpa_flags) {
				printf("[%s%s%s%s",
					bgpa.bgpa_flags & 0x80 ? "O" : "",
					bgpa.bgpa_flags & 0x40 ? "T" : "",
					bgpa.bgpa_flags & 0x20 ? "P" : "",
					bgpa.bgpa_flags & 0x10 ? "E" : "");
				if (bgpa.bgpa_flags & 0xf)
					printf("+%x", bgpa.bgpa_flags & 0xf);
				printf("]");
			}

			bgp_attr_print(&bgpa, &p[i + aoff], alen);
			newline = 1;

			/* ( */
			printf(")");	

			i += aoff + alen;
		}

		/* ( */
		printf(")");
	}
	p += 2 + len;

	if (len && dat + length > p)
		printf("\n\t\t");
	if (dat + length > p) {
		printf("(NLRI:");	/* ) */
		while (dat + length > p) {
			char buf[MAXHOSTNAMELEN + 100];
			i = decode_prefix4(p, buf, sizeof(buf));
			printf(" %s", buf);
			if (i < 0)
				break;
			p += i;
		}

		/* ( */
		printf(")");
	}
	return;
trunc:
	printf("[|BGP]");
}

static void
bgp_notification_print(const u_char *dat, int length)
{
	struct bgp_notification bgpn;
	int hlen;

	TCHECK2(dat[0], sizeof(bgpn));
	memcpy(&bgpn, dat, sizeof(bgpn));
	hlen = ntohs(bgpn.bgpn_len);

	printf(": error %s,", bgp_notify_major(bgpn.bgpn_major));
	printf(" subcode %s",
		bgp_notify_minor(bgpn.bgpn_major, bgpn.bgpn_minor));
	return;
trunc:
	printf("[|BGP]");
}

static void
bgp_header_print(const u_char *dat, int length)
{
	struct bgp bgp;

	TCHECK2(dat[0], sizeof(bgp));
	memcpy(&bgp, dat, sizeof(bgp));
	printf("(%s", bgp_type(bgp.bgp_type));		/* ) */

	switch (bgp.bgp_type) {
	case BGP_OPEN:
		bgp_open_print(dat, length);
		break;
	case BGP_UPDATE:
		bgp_update_print(dat, length);
		break;
	case BGP_NOTIFICATION:
		bgp_notification_print(dat, length);
		break;
	}

	/* ( */
	printf(")");
	return;
trunc:
	printf("[|BGP]");
}

void
bgp_print(const u_char *dat, int length)
{
	const u_char *p;
	const u_char *ep;
	const u_char *start;
	const u_char marker[] = {
		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 
		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 
	};
	struct bgp bgp;
	u_int16_t hlen;
	int newline;

	ep = dat + length;
	if (snapend < dat + length)
		ep = snapend;

	printf(": BGP");

	p = dat;
	newline = 0;
	start = p;
	while (p < snapend) {
		if (!TTEST2(p[0], 1))
			break;
		if (p[0] != 0xff) {
			p++;
			continue;
		}

		if (!TTEST2(p[0], sizeof(marker)))
			break;
		if (memcmp(p, marker, sizeof(marker)) != 0) {
			p++;
			continue;
		}

		/* found BGP header */
		TCHECK2(p[0], sizeof(bgp));	/*XXX*/
		memcpy(&bgp, p, sizeof(bgp));

		if (start != p)
			printf(" [|BGP]");

		hlen = ntohs(bgp.bgp_len);
		if (vflag && newline)
			printf("\n\t");
		else
			printf(" ");
		if (TTEST2(p[0], hlen)) {
			bgp_header_print(p, hlen);
			newline = 1;
			p += hlen;
			start = p;
		} else {
			printf("[|BGP %s]", bgp_type(bgp.bgp_type));
			break;
		}
	}

	return;

trunc:
	printf(" [|BGP]");
}