print-domain.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 752 行 · 第 1/2 页

	i = EXTRACT_16BITS(cp);
	cp += 2;
	if (is_mdns)
		class = (i & ~C_CACHE_FLUSH);
	else
		class = i;
	if (class != C_IN && typ != T_OPT)
		printf(" %s", tok2str(ns_class2str, "(Class %d)", class));
	if (is_mdns) {
		if (i & C_CACHE_FLUSH)
			printf(" (Cache flush)");
	}

	if (typ == T_OPT) {
		/* get opt flags */
		cp += 2;
		opt_flags = EXTRACT_16BITS(cp);
		/* ignore rest of ttl field */
		cp += 2;
	} else if (vflag > 2) {
		/* print ttl */
		printf(" [");
		relts_print(EXTRACT_32BITS(cp));
		printf("]");
		cp += 4;
	} else {
		/* ignore ttl */
		cp += 4;
	}

	len = EXTRACT_16BITS(cp);
	cp += 2;

	rp = cp + len;

	printf(" %s", tok2str(ns_type2str, "Type%d", typ));
	if (rp > snapend)
		return(NULL);

	switch (typ) {
	case T_A:
		if (!TTEST2(*cp, sizeof(struct in_addr)))
			return(NULL);
		printf(" %s", intoa(htonl(EXTRACT_32BITS(cp))));
		break;

	case T_NS:
	case T_CNAME:
	case T_PTR:
#ifdef T_DNAME
	case T_DNAME:
#endif
		putchar(' ');
		if (ns_nprint(cp, bp) == NULL)
			return(NULL);
		break;

	case T_SOA:
		if (!vflag)
			break;
		putchar(' ');
		if ((cp = ns_nprint(cp, bp)) == NULL)
			return(NULL);
		putchar(' ');
		if ((cp = ns_nprint(cp, bp)) == NULL)
			return(NULL);
		if (!TTEST2(*cp, 5 * 4))
			return(NULL);
		printf(" %u", EXTRACT_32BITS(cp));
		cp += 4;
		printf(" %u", EXTRACT_32BITS(cp));
		cp += 4;
		printf(" %u", EXTRACT_32BITS(cp));
		cp += 4;
		printf(" %u", EXTRACT_32BITS(cp));
		cp += 4;
		printf(" %u", EXTRACT_32BITS(cp));
		cp += 4;
		break;
	case T_MX:
		putchar(' ');
		if (!TTEST2(*cp, 2))
			return(NULL);
		if (ns_nprint(cp + 2, bp) == NULL)
			return(NULL);
		printf(" %d", EXTRACT_16BITS(cp));
		break;

	case T_TXT:
		while (cp < rp) {
			printf(" \"");
			cp = ns_cprint(cp);
			if (cp == NULL)
				return(NULL);
			putchar('"');
		}
		break;

	case T_SRV:
		putchar(' ');
		if (!TTEST2(*cp, 6))
			return(NULL);
		if (ns_nprint(cp + 6, bp) == NULL)
			return(NULL);
		printf(":%d %d %d", EXTRACT_16BITS(cp + 4),
			EXTRACT_16BITS(cp), EXTRACT_16BITS(cp + 2));
		break;

#ifdef INET6
	case T_AAAA:
	    {
		struct in6_addr addr;
		char ntop_buf[INET6_ADDRSTRLEN];

		if (!TTEST2(*cp, sizeof(struct in6_addr)))
			return(NULL);
		memcpy(&addr, cp, sizeof(struct in6_addr));
		printf(" %s",
		    inet_ntop(AF_INET6, &addr, ntop_buf, sizeof(ntop_buf)));

		break;
	    }

	case T_A6:
	    {
		struct in6_addr a;
		int pbit, pbyte;
		char ntop_buf[INET6_ADDRSTRLEN];

		if (!TTEST2(*cp, 1))
			return(NULL);
		pbit = *cp;
		pbyte = (pbit & ~7) / 8;
		if (pbit > 128) {
			printf(" %u(bad plen)", pbit);
			break;
		} else if (pbit < 128) {
			if (!TTEST2(*(cp + 1), sizeof(a) - pbyte))
				return(NULL);
			memset(&a, 0, sizeof(a));
			memcpy(&a.s6_addr[pbyte], cp + 1, sizeof(a) - pbyte);
			printf(" %u %s", pbit,
			    inet_ntop(AF_INET6, &a, ntop_buf, sizeof(ntop_buf)));
		}
		if (pbit > 0) {
			putchar(' ');
			if (ns_nprint(cp + 1 + sizeof(a) - pbyte, bp) == NULL)
				return(NULL);
		}
		break;
	    }
#endif /*INET6*/

	case T_OPT:
		printf(" UDPsize=%u", class);
		if (opt_flags & 0x8000)
			printf(" OK");
		break;

	case T_UNSPECA:		/* One long string */
		if (!TTEST2(*cp, len))
			return(NULL);
		if (fn_printn(cp, len, snapend))
			return(NULL);
		break;

	case T_TSIG:
	    {
		if (cp + len > snapend)
			return(NULL);
		if (!vflag)
			break;
		putchar(' ');
		if ((cp = ns_nprint(cp, bp)) == NULL)
			return(NULL);
		cp += 6;
		if (!TTEST2(*cp, 2))
			return(NULL);
		printf(" fudge=%u", EXTRACT_16BITS(cp));
		cp += 2;
		if (!TTEST2(*cp, 2))
			return(NULL);
		printf(" maclen=%u", EXTRACT_16BITS(cp));
		cp += 2 + EXTRACT_16BITS(cp);
		if (!TTEST2(*cp, 2))
			return(NULL);
		printf(" origid=%u", EXTRACT_16BITS(cp));
		cp += 2;
		if (!TTEST2(*cp, 2))
			return(NULL);
		printf(" error=%u", EXTRACT_16BITS(cp));
		cp += 2;
		if (!TTEST2(*cp, 2))
			return(NULL);
		printf(" otherlen=%u", EXTRACT_16BITS(cp));
		cp += 2;
	    }
	}
	return (rp);		/* XXX This isn't always right */
}

void
ns_print(register const u_char *bp, u_int length, int is_mdns)
{
	register const HEADER *np;
	register int qdcount, ancount, nscount, arcount;
	register const u_char *cp;
	u_int16_t b2;

	np = (const HEADER *)bp;
	TCHECK(*np);
	/* get the byte-order right */
	qdcount = EXTRACT_16BITS(&np->qdcount);
	ancount = EXTRACT_16BITS(&np->ancount);
	nscount = EXTRACT_16BITS(&np->nscount);
	arcount = EXTRACT_16BITS(&np->arcount);

	if (DNS_QR(np)) {
		/* this is a response */
		printf("%d%s%s%s%s%s%s",
			EXTRACT_16BITS(&np->id),
			ns_ops[DNS_OPCODE(np)],
			ns_resp[DNS_RCODE(np)],
			DNS_AA(np)? "*" : "",
			DNS_RA(np)? "" : "-",
			DNS_TC(np)? "|" : "",
			DNS_AD(np)? "$" : "");

		if (qdcount != 1)
			printf(" [%dq]", qdcount);
		/* Print QUESTION section on -vv */
		cp = (const u_char *)(np + 1);
		while (qdcount--) {
			if (qdcount < EXTRACT_16BITS(&np->qdcount) - 1)
				putchar(',');
			if (vflag > 1) {
				fputs(" q:", stdout);
				if ((cp = ns_qprint(cp, bp, is_mdns)) == NULL)
					goto trunc;
			} else {
				if ((cp = ns_nskip(cp)) == NULL)
					goto trunc;
				cp += 4;	/* skip QTYPE and QCLASS */
			}
		}
		printf(" %d/%d/%d", ancount, nscount, arcount);
		if (ancount--) {
			if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
				goto trunc;
			while (cp < snapend && ancount--) {
				putchar(',');
				if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
					goto trunc;
			}
		}
		if (ancount > 0)
			goto trunc;
		/* Print NS and AR sections on -vv */
		if (vflag > 1) {
			if (cp < snapend && nscount--) {
				fputs(" ns:", stdout);
				if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (cp < snapend && nscount--) {
					putchar(',');
					if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (nscount > 0)
				goto trunc;
			if (cp < snapend && arcount--) {
				fputs(" ar:", stdout);
				if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (cp < snapend && arcount--) {
					putchar(',');
					if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (arcount > 0)
				goto trunc;
		}
	}
	else {
		/* this is a request */
		printf("%d%s%s%s", EXTRACT_16BITS(&np->id), ns_ops[DNS_OPCODE(np)],
		    DNS_RD(np) ? "+" : "",
		    DNS_CD(np) ? "%" : "");

		/* any weirdness? */
		b2 = EXTRACT_16BITS(((u_short *)np)+1);
		if (b2 & 0x6cf)
			printf(" [b2&3=0x%x]", b2);

		if (DNS_OPCODE(np) == IQUERY) {
			if (qdcount)
				printf(" [%dq]", qdcount);
			if (ancount != 1)
				printf(" [%da]", ancount);
		}
		else {
			if (ancount)
				printf(" [%da]", ancount);
			if (qdcount != 1)
				printf(" [%dq]", qdcount);
		}
		if (nscount)
			printf(" [%dn]", nscount);
		if (arcount)
			printf(" [%dau]", arcount);

		cp = (const u_char *)(np + 1);
		if (qdcount--) {
			cp = ns_qprint(cp, (const u_char *)np, is_mdns);
			if (!cp)
				goto trunc;
			while (cp < snapend && qdcount--) {
				cp = ns_qprint((const u_char *)cp,
					       (const u_char *)np,
					       is_mdns);
				if (!cp)
					goto trunc;
			}
		}
		if (qdcount > 0)
			goto trunc;

		/* Print remaining sections on -vv */
		if (vflag > 1) {
			if (ancount--) {
				if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (cp < snapend && ancount--) {
					putchar(',');
					if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (ancount > 0)
				goto trunc;
			if (cp < snapend && nscount--) {
				fputs(" ns:", stdout);
				if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (nscount-- && cp < snapend) {
					putchar(',');
					if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (nscount > 0)
				goto trunc;
			if (cp < snapend && arcount--) {
				fputs(" ar:", stdout);
				if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (cp < snapend && arcount--) {
					putchar(',');
					if ((cp = ns_rprint(cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (arcount > 0)
				goto trunc;
		}
	}
	printf(" (%d)", length);
	return;

  trunc:
	printf("[|domain]");
	return;
}