ping6.c

IPv6环境中的ping实现

			goto fqdnend;
		case ICMP6_NI_UNKNOWN:
			printf("unknown, type 0x%x", ntohs(ni->ni_type));
			goto fqdnend;
		default:
			printf("unknown code 0x%x, type 0x%x",
			    ntohs(ni->ni_code), ntohs(ni->ni_type));
			goto fqdnend;
		}

		switch (ntohs(ni->ni_qtype)) {
		case NI_QTYPE_NOOP:
			printf("NodeInfo NOOP");
			break;
		case NI_QTYPE_SUPTYPES:
			pr_suptypes(ni, end - (u_char *)ni);
			break;
		case NI_QTYPE_NODEADDR:
			pr_nodeaddr(ni, end - (u_char *)ni);
			break;
		case NI_QTYPE_FQDN:
		default:	/* XXX: for backward compatibility */
			cp = (u_char *)ni + ICMP6_NIRLEN;
			if (buf[off + ICMP6_NIRLEN] ==
			    cc - off - ICMP6_NIRLEN - 1)
				oldfqdn = 1;
			else
				oldfqdn = 0;
			if (oldfqdn) {
				cp++;	/* skip length */
				while (cp < end) {
					safeputc(*cp & 0xff);
					cp++;
				}
			} else {
				i = 0;
				while (cp < end) {
					if (dnsdecode((const u_char **)&cp, end,
					    (const u_char *)(ni + 1), dnsname,
					    sizeof(dnsname)) == NULL) {
						printf("???");
						break;
					}
					/*
					 * name-lookup special handling for
					 * truncated name
					 */
					if (cp + 1 <= end && !*cp &&
					    strlen(dnsname) > 0) {
						dnsname[strlen(dnsname) - 1] = '\0';
						cp++;
					}
					printf("%s%s", i > 0 ? "," : "",
					    dnsname);
				}
			}
			if (options & F_VERBOSE) {
				int32_t ttl;
				int comma = 0;

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

				switch (ni->ni_code) {
				case ICMP6_NI_REFUSED:
					(void)printf("refused");
					comma++;
					break;
				case ICMP6_NI_UNKNOWN:
					(void)printf("unknown qtype");
					comma++;
					break;
				}

				if ((end - (u_char *)ni) < ICMP6_NIRLEN) {
					/* case of refusion, unknown */
					/*(*/
					putchar(')');
					goto fqdnend;
				}
				ttl = (int32_t)ntohl(*(u_long *)&buf[off+ICMP6ECHOLEN+8]);
				if (comma)
					printf(",");
				if (!(ni->ni_flags & NI_FQDN_FLAG_VALIDTTL)) {
					(void)printf("TTL=%d:meaningless",
					    (int)ttl);
				} else {
					if (ttl < 0) {
						(void)printf("TTL=%d:invalid",
						   ttl);
					} else
						(void)printf("TTL=%d", ttl);
				}
				comma++;

				if (oldfqdn) {
					if (comma)
						printf(",");
					printf("03 draft");
					comma++;
				} else {
					cp = (u_char *)ni + ICMP6_NIRLEN;
					if (cp == end) {
						if (comma)
							printf(",");
						printf("no name");
						comma++;
					}
				}

				if (buf[off + ICMP6_NIRLEN] !=
				    cc - off - ICMP6_NIRLEN - 1 && oldfqdn) {
					if (comma)
						printf(",");
					(void)printf("invalid namelen:%d/%lu",
					    buf[off + ICMP6_NIRLEN],
					    (u_long)cc - off - ICMP6_NIRLEN - 1);
					comma++;
				}
				/*(*/
				putchar(')');
			}
		fqdnend:
			;
		}
	} else {
		/* We've got something other than an ECHOREPLY */
		if (!(options & F_VERBOSE))
			return;
		(void)printf("%d bytes from %s: ", cc, pr_addr(from, fromlen));
		pr_icmph(icp, end);
	}

	if (!(options & F_FLOOD)) {
		(void)putchar('\n');
		if (options & F_VERBOSE)
			pr_exthdrs(mhdr);
		(void)fflush(stdout);
	}
#undef safeputc
}

void
pr_exthdrs(mhdr)
	struct msghdr *mhdr;
{
	struct cmsghdr *cm;

	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
	     cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
		if (cm->cmsg_level != IPPROTO_IPV6)
			continue;

		switch (cm->cmsg_type) {
		case IPV6_HOPOPTS:
			printf("  HbH Options: ");
			pr_ip6opt(CMSG_DATA(cm));
			break;
		case IPV6_DSTOPTS:
#ifdef IPV6_RTHDRDSTOPTS
		case IPV6_RTHDRDSTOPTS:
#endif
			printf("  Dst Options: ");
			pr_ip6opt(CMSG_DATA(cm));
			break;
		case IPV6_RTHDR:
			printf("  Routing: ");
			pr_rthdr(CMSG_DATA(cm));
			break;
		}
	}
}

#ifdef USE_RFC2292BIS
void
pr_ip6opt(void *extbuf)
{
	struct ip6_hbh *ext;
	int currentlen;
	u_int8_t type;
	size_t extlen, len;
	void *databuf;
	size_t offset;
	u_int16_t value2;
	u_int32_t value4;

	ext = (struct ip6_hbh *)extbuf;
	extlen = (ext->ip6h_len + 1) * 8;
	printf("nxt %u, len %u (%lu bytes)\n", ext->ip6h_nxt,
	    (unsigned int)ext->ip6h_len, (unsigned long)extlen);

	currentlen = 0;
	while (1) {
		currentlen = inet6_opt_next(extbuf, extlen, currentlen,
		    &type, &len, &databuf);
		if (currentlen == -1)
			break;
		switch (type) {
		/*
		 * Note that inet6_opt_next automatically skips any padding
		 * optins.
		 */
		case IP6OPT_JUMBO:
			offset = 0;
			offset = inet6_opt_get_val(databuf, offset,
			    &value4, sizeof(value4));
			printf("    Jumbo Payload Opt: Length %u\n",
			    (u_int32_t)ntohl(value4));
			break;
		case IP6OPT_ROUTER_ALERT:
			offset = 0;
			offset = inet6_opt_get_val(databuf, offset,
						   &value2, sizeof(value2));
			printf("    Router Alert Opt: Type %u\n",
			    ntohs(value2));
			break;
		default:
			printf("    Received Opt %u len %lu\n",
			    type, (unsigned long)len);
			break;
		}
	}
	return;
}
#else  /* !USE_RFC2292BIS */
/* ARGSUSED */
void
pr_ip6opt(void *extbuf)
{
	putchar('\n');
	return;
}
#endif /* USE_RFC2292BIS */

#ifdef USE_RFC2292BIS
void
pr_rthdr(void *extbuf)
{
	struct in6_addr *in6;
	char ntopbuf[INET6_ADDRSTRLEN];
	struct ip6_rthdr *rh = (struct ip6_rthdr *)extbuf;
	int i, segments;

	/* print fixed part of the header */
	printf("nxt %u, len %u (%d bytes), type %u, ", rh->ip6r_nxt,
	    rh->ip6r_len, (rh->ip6r_len + 1) << 3, rh->ip6r_type);
	if ((segments = inet6_rth_segments(extbuf)) >= 0)
		printf("%d segments, ", segments);
	else
		printf("segments unknown, ");
	printf("%d left\n", rh->ip6r_segleft);

	for (i = 0; i < segments; i++) {
		in6 = inet6_rth_getaddr(extbuf, i);
		if (in6 == NULL)
			printf("   [%d]<NULL>\n", i);
		else {
			if (!inet_ntop(AF_INET6, in6, ntopbuf,
			    sizeof(ntopbuf)))
				strncpy(ntopbuf, "?", sizeof(ntopbuf));
			printf("   [%d]%s\n", i, ntopbuf);
		}
	}

	return;

}

#else  /* !USE_RFC2292BIS */
/* ARGSUSED */
void
pr_rthdr(void *extbuf)
{
	putchar('\n');
	return;
}
#endif /* USE_RFC2292BIS */

int
pr_bitrange(v, soff, ii)
	u_int32_t v;
	int soff;
	int ii;
{
	int off;
	int i;

	off = 0;
	while (off < 32) {
		/* shift till we have 0x01 */
		if ((v & 0x01) == 0) {
			if (ii > 1)
				printf("-%u", soff + off - 1);
			ii = 0;
			switch (v & 0x0f) {
			case 0x00:
				v >>= 4;
				off += 4;
				continue;
			case 0x08:
				v >>= 3;
				off += 3;
				continue;
			case 0x04: case 0x0c:
				v >>= 2;
				off += 2;
				continue;
			default:
				v >>= 1;
				off += 1;
				continue;
			}
		}

		/* we have 0x01 with us */
		for (i = 0; i < 32 - off; i++) {
			if ((v & (0x01 << i)) == 0)
				break;
		}
		if (!ii)
			printf(" %u", soff + off);
		ii += i;
		v >>= i; off += i;
	}
	return ii;
}

void
pr_suptypes(ni, nilen)
	struct icmp6_nodeinfo *ni; /* ni->qtype must be SUPTYPES */
	size_t nilen;
{
	size_t clen;
	u_int32_t v;
	const u_char *cp, *end;
	u_int16_t cur;
	struct cbit {
		u_int16_t words;	/*32bit count*/
		u_int16_t skip;
	} cbit;
#define MAXQTYPES	(1 << 16)
	size_t off;
	int b;

	cp = (u_char *)(ni + 1);
	end = ((u_char *)ni) + nilen;
	cur = 0;
	b = 0;

	printf("NodeInfo Supported Qtypes");
	if (options & F_VERBOSE) {
		if (ni->ni_flags & NI_SUPTYPE_FLAG_COMPRESS)
			printf(", compressed bitmap");
		else
			printf(", raw bitmap");
	}

	while (cp < end) {
		clen = (size_t)(end - cp);
		if ((ni->ni_flags & NI_SUPTYPE_FLAG_COMPRESS) == 0) {
			if (clen == 0 || clen > MAXQTYPES / 8 ||
			    clen % sizeof(v)) {
				printf("???");
				return;
			}
		} else {
			if (clen < sizeof(cbit) || clen % sizeof(v))
				return;
			memcpy(&cbit, cp, sizeof(cbit));
			if (sizeof(cbit) + ntohs(cbit.words) * sizeof(v) >
			    clen)
				return;
			cp += sizeof(cbit);
			clen = ntohs(cbit.words) * sizeof(v);
			if (cur + clen * 8 + (u_long)ntohs(cbit.skip) * 32 >
			    MAXQTYPES)
				return;
		}

		for (off = 0; off < clen; off += sizeof(v)) {
			memcpy(&v, cp + off, sizeof(v));
			v = (u_int32_t)ntohl(v);
			b = pr_bitrange(v, (int)(cur + off * 8), b);
		}
		/* flush the remaining bits */
		b = pr_bitrange(0, (int)(cur + off * 8), b);

		cp += clen;
		cur += clen * 8;
		if ((ni->ni_flags & NI_SUPTYPE_FLAG_COMPRESS) != 0)
			cur += ntohs(cbit.skip) * 32;
	}
}

void
pr_nodeaddr(ni, nilen)
	struct icmp6_nodeinfo *ni; /* ni->qtype must be NODEADDR */
	int nilen;
{
	u_char *cp = (u_char *)(ni + 1);
	char ntop_buf[INET6_ADDRSTRLEN];
	int withttl = 0;

	nilen -= sizeof(struct icmp6_nodeinfo);

	if (options & F_VERBOSE) {
		switch (ni->ni_code) {
		case ICMP6_NI_REFUSED:
			(void)printf("refused");
			break;
		case ICMP6_NI_UNKNOWN:
			(void)printf("unknown qtype");
			break;
		}
		if (ni->ni_flags & NI_NODEADDR_FLAG_TRUNCATE)
			(void)printf(" truncated");
	}
	putchar('\n');
	if (nilen <= 0)
		printf("  no address\n");

	/*
	 * In icmp-name-lookups 05 and later, TTL of each returned address
	 * is contained in the resposne. We try to detect the version
	 * by the length of the data, but note that the detection algorithm
	 * is incomplete. We assume the latest draft by default.
	 */
	if (nilen % (sizeof(u_int32_t) + sizeof(struct in6_addr)) == 0)
		withttl = 1;
	while (nilen > 0) {
		u_int32_t ttl;

		if (withttl) {
			/* XXX: alignment? */
			ttl = (u_int32_t)ntohl(*(u_int32_t *)cp);
			cp += sizeof(u_int32_t);
			nilen -= sizeof(u_int32_t);
		}

		if (inet_ntop(AF_INET6, cp, ntop_buf, sizeof(ntop_buf)) ==
		    NULL)
			strncpy(ntop_buf, "?", sizeof(ntop_buf));
		printf("  %s", ntop_buf);
		if (withttl) {
			if (ttl == 0xffffffff) {
				/*
				 * XXX: can this convention be applied to all
				 * type of TTL (i.e. non-ND TTL)?
				 */
				printf("(TTL=infty)");
			}
			else
				printf("(TTL=%u)", ttl);
		}
		putchar('\n');

		nilen -= sizeof(struct in6_addr);
		cp += sizeof(struct in6_addr);
	}
}

int
get_hoplim(mhdr)
	struct msghdr *mhdr;
{
	struct cmsghdr *cm;

	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
	     cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
		if (cm->cmsg_len == 0)
			return(-1);

		if (cm->cmsg_level == IPPROTO_IPV6 &&
		    cm->cmsg_type == IPV6_HOPLIMIT &&
		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
			return(*(int *)CMSG_DATA(cm));
	}

	return(-1);
}

struct in6_pktinfo *
get_rcvpktinfo(mhdr)
	struct msghdr *mhdr;
{
	struct cmsghdr *cm;

	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
	     cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
		if (cm->cmsg_len == 0)
			return(NULL);

		if (cm->cmsg_level == IPPROTO_IPV6 &&
		    cm->cmsg_type == IPV6_PKTINFO &&
		    cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo)))
			return((struct in6_pktinfo *)CMSG_DATA(cm));
	}

	return(NULL);
}

int
get_pathmtu(mhdr)
	struct msghdr *mhdr;
{
#ifdef IPV6_RECVPATHMTU
	struct cmsghdr *cm;
	struct ip6_mtuinfo *mtuctl = NULL;

	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
	     cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
		if (cm->cmsg_len == 0)
			return(0);

		if (cm->cmsg_level == IPPROTO_IPV6 &&
		    cm->cmsg_type == IPV6_PATHMTU &&
		    cm->cmsg_len == CMSG_LEN(sizeof(struct ip6_mtuinfo))) {
			mtuctl = (struct ip6_mtuinfo *)CMSG_DATA(cm);

			/*
			 * If the notified destination is different from
			 * the one we are pinging, just ignore the info.
			 * We check the scope ID only when both notified value
			 * and our own value have non-0 values, because we may
			 * have used the default scope zone ID for sending,
			 * in which case the scope ID value is 0.
			 */
			if (!IN6_ARE_ADDR_EQUAL(&mtuctl->ip6m_addr.sin6_addr,
						&dst.sin6_addr) ||