Merge pull request #48 from pavlix/dualstack

3 files changed, 233 insertions, 670 deletions

diff --git a/Makefile b/Makefile
index e60ed80..3a4198e 100644
--- a/Makefile
+++ b/Makefile
@@ -116,7 +116,7 @@ endif
 endif
 
 # -------------------------------------
-TARGETS=ping tracepath tracepath6 traceroute6 clockdiff rdisc arping tftpd rarpd
+TARGETS=ping tracepath traceroute6 clockdiff rdisc arping tftpd rarpd
 
 LDLIBS=$(LDLIB) $(ADDLIB)
 
@@ -175,10 +175,6 @@ LIB_rdisc =
 DEF_tracepath = $(DEF_IDN)
 LIB_tracepath = $(LIB_IDN)
 
-# tracepath6
-DEF_tracepath6 = $(DEF_IDN)
-LIB_tracepath6 =
-
 # traceroute6
 DEF_traceroute6 = $(DEF_CAP) $(DEF_IDN)
 LIB_traceroute6 = $(LIB_CAP) $(LIB_IDN)
diff --git a/tracepath.c b/tracepath.c
index c57a127..74a829d 100644
--- a/tracepath.c
+++ b/tracepath.c
@@ -13,29 +13,37 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/icmp6.h>
+
 #include <linux/types.h>
+#include <linux/errqueue.h>
 #include <errno.h>
 #include <string.h>
 #include <netdb.h>
 #include <limits.h>
-#include <netinet/in.h>
 #include <resolv.h>
 #include <sys/time.h>
-#include <linux/errqueue.h>
 #include <sys/uio.h>
 #include <arpa/inet.h>
 
 #ifdef USE_IDN
 #include <idna.h>
 #include <locale.h>
-
 #define getnameinfo_flags	NI_IDN
 #else
 #define getnameinfo_flags	0
 #endif
 
-#ifndef IP_PMTUDISC_PROBE
-#define IP_PMTUDISC_PROBE	3
+#ifndef SOL_IPV6
+#define SOL_IPV6 IPPROTO_IPV6
+#endif
+
+#ifndef IP_PMTUDISC_DO
+#define IP_PMTUDISC_DO		3
+#endif
+#ifndef IPV6_PMTUDISC_DO
+#define IPV6_PMTUDISC_DO	3
 #endif
 
 #define MAX_HOPS_LIMIT		255
@@ -50,17 +58,19 @@ struct hhistory
 struct hhistory his[64];
 int hisptr;
 
-struct sockaddr_in target;
+struct sockaddr_storage target;
+socklen_t targetlen;
 __u16 base_port;
 int max_hops = MAX_HOPS_DEFAULT;
 
-const int overhead = 28;
-int mtu = 65535;
+int overhead;
+int mtu;
 void *pktbuf;
 int hops_to = -1;
 int hops_from = -1;
 int no_resolve = 0;
 int show_both = 0;
+int mapped;
 
 #define HOST_COLUMN_SIZE	52
 
@@ -92,7 +102,7 @@ void print_host(const char *a, const char *b, int both)
 	printf("%*s", HOST_COLUMN_SIZE - plen, "");
 }
 
-int recverr(int fd, int ttl)
+int recverr(int fd, struct addrinfo *ai, int ttl)
 {
 	int res;
 	struct probehdr rcvbuf;
@@ -101,10 +111,10 @@ int recverr(int fd, int ttl)
 	struct msghdr msg;
 	struct cmsghdr *cmsg;
 	struct sock_extended_err *e;
-	struct sockaddr_in addr;
+	struct sockaddr_storage addr;
 	struct timeval tv;
 	struct timeval *rettv;
-	int slot;
+	int slot = 0;
 	int rethops;
 	int sndhops;
 	int progress = -1;
@@ -137,30 +147,59 @@ restart:
 	sndhops = -1;
 	e = NULL;
 	rettv = NULL;
-	slot = ntohs(addr.sin_port) - base_port;
-	if (slot>=0 && slot < 63 && his[slot].hops) {
+
+	slot = -base_port;
+	switch (ai->ai_family) {
+	case AF_INET6:
+		slot += ntohs(((struct sockaddr_in6 *)&addr)->sin6_port);
+		break;
+	case AF_INET:
+		slot += ntohs(((struct sockaddr_in *)&addr)->sin_port);
+		break;
+	}
+
+	if (slot >= 0 && slot < 63 && his[slot].hops) {
 		sndhops = his[slot].hops;
 		rettv = &his[slot].sendtime;
 		his[slot].hops = 0;
 	}
 	broken_router = 0;
 	if (res == sizeof(rcvbuf)) {
-		if (rcvbuf.ttl == 0 || rcvbuf.tv.tv_sec == 0) {
+		if (rcvbuf.ttl == 0 || rcvbuf.tv.tv_sec == 0)
 			broken_router = 1;
-		} else {
+		else {
 			sndhops = rcvbuf.ttl;
 			rettv = &rcvbuf.tv;
 		}
 	}
 
 	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-		if (cmsg->cmsg_level == SOL_IP) {
-			if (cmsg->cmsg_type == IP_RECVERR) {
-				e = (struct sock_extended_err *) CMSG_DATA(cmsg);
-			} else if (cmsg->cmsg_type == IP_TTL) {
+		switch (cmsg->cmsg_level) {
+		case SOL_IPV6:
+			switch(cmsg->cmsg_type) {
+			case IPV6_RECVERR:
+				e = (struct sock_extended_err *)CMSG_DATA(cmsg);
+				break;
+			case IPV6_HOPLIMIT:
+#ifdef IPV6_2292HOPLIMIT
+			case IPV6_2292HOPLIMIT:
+#endif
 				memcpy(&rethops, CMSG_DATA(cmsg), sizeof(rethops));
-			} else {
-				printf("cmsg:%d\n ", cmsg->cmsg_type);
+				break;
+			default:
+				printf("cmsg6:%d\n ", cmsg->cmsg_type);
+			}
+			break;
+		case SOL_IP:
+			switch(cmsg->cmsg_type) {
+			case IP_RECVERR:
+				e = (struct sock_extended_err *)CMSG_DATA(cmsg);
+				break;
+			case IP_TTL:
+				rethops = *(__u8*)CMSG_DATA(cmsg);
+				break;
+			default:
+				printf("cmsg4:%d\n ", cmsg->cmsg_type);
 			}
 		}
 	}
@@ -168,23 +207,44 @@ restart:
 		printf("no info\n");
 		return 0;
 	}
-	if (e->ee_origin == SO_EE_ORIGIN_LOCAL) {
-		printf("%2d?: %*s ", ttl, -(HOST_COLUMN_SIZE - 1), "[LOCALHOST]");
-	} else if (e->ee_origin == SO_EE_ORIGIN_ICMP) {
-		char abuf[128];
-		struct sockaddr_in *sin = (struct sockaddr_in*)(e+1);
-
-		inet_ntop(AF_INET, &sin->sin_addr, abuf, sizeof(abuf));
+	if (e->ee_origin == SO_EE_ORIGIN_LOCAL)
+		printf("%2d?: %-32s ", ttl, "[LOCALHOST]");
+	else if (e->ee_origin == SO_EE_ORIGIN_ICMP6 ||
+		 e->ee_origin == SO_EE_ORIGIN_ICMP) {
+		char abuf[NI_MAXHOST];
+		struct sockaddr *sa = (struct sockaddr *)(e + 1);
+		socklen_t salen;
 
 		if (sndhops>0)
 			printf("%2d:  ", sndhops);
 		else
 			printf("%2d?: ", ttl);
 
+		switch (sa->sa_family) {
+		case AF_INET6:
+			salen = sizeof(struct sockaddr_in6);
+			break;
+		case AF_INET:
+			salen = sizeof(struct sockaddr_in);
+			break;
+		default:
+			salen = 0;
+		}
+
+		if (no_resolve || show_both) {
+			if (getnameinfo(sa, salen,
+					abuf, sizeof(abuf), NULL, 0,
+					NI_NUMERICHOST))
+				strcpy(abuf, "???");
+		} else
+			abuf[0] = 0;
+
 		if (!no_resolve || show_both) {
 			fflush(stdout);
-			getnameinfo((struct sockaddr *) sin, sizeof *sin, hnamebuf, sizeof hnamebuf, NULL, 0, getnameinfo_flags);
-		}
+			if (getnameinfo(sa, salen, hnamebuf, sizeof hnamebuf, NULL, 0, getnameinfo_flags))
+				strcpy(hnamebuf, "???");
+		} else
+			hnamebuf[0] = 0;
 
 		if (no_resolve)
 			print_host(abuf, hnamebuf, show_both);
@@ -224,9 +284,12 @@ restart:
 		printf("!P\n");
 		return 0;
 	case EHOSTUNREACH:
-		if (e->ee_origin == SO_EE_ORIGIN_ICMP &&
-		    e->ee_type == 11 &&
-		    e->ee_code == 0) {
+		if ((e->ee_origin == SO_EE_ORIGIN_ICMP &&
+		     e->ee_type == 11 &&
+		     e->ee_code == 0) ||
+		    (e->ee_origin == SO_EE_ORIGIN_ICMP6 &&
+		     e->ee_type == 3 &&
+		     e->ee_code == 0)) {
 			if (rethops>=0) {
 				if (sndhops>=0 && rethops != sndhops)
 					printf("asymm %2d ", rethops);
@@ -253,7 +316,7 @@ restart:
 	goto restart;
 }
 
-int probe_ttl(int fd, int ttl)
+int probe_ttl(int fd, struct addrinfo *ai, int ttl)
 {
 	int i;
 	struct probehdr *hdr = pktbuf;
@@ -264,20 +327,27 @@ restart:
 		int res;
 
 		hdr->ttl = ttl;
-		target.sin_port = htons(base_port + hisptr);
+		switch (ai->ai_family) {
+		case AF_INET6:
+			((struct sockaddr_in6 *)&target)->sin6_port = htons(base_port + hisptr);
+			break;
+		case AF_INET:
+			((struct sockaddr_in *)&target)->sin_port = htons(base_port + hisptr);
+			break;
+		}
 		gettimeofday(&hdr->tv, NULL);
 		his[hisptr].hops = ttl;
 		his[hisptr].sendtime = hdr->tv;
-		if (sendto(fd, pktbuf, mtu-overhead, 0, (struct sockaddr*)&target, sizeof(target)) > 0)
+		if (sendto(fd, pktbuf, mtu-overhead, 0, (struct sockaddr *)&target, targetlen) > 0)
 			break;
-		res = recverr(fd, ttl);
+		res = recverr(fd, ai, ttl);
 		his[hisptr].hops = 0;
 		if (res==0)
 			return 0;
 		if (res > 0)
 			goto restart;
 	}
-	hisptr = (hisptr + 1)&63;
+	hisptr = (hisptr + 1) & 63;
 
 	if (i<10) {
 		data_wait(fd);
@@ -285,7 +355,7 @@ restart:
 			printf("%2d?: reply received 8)\n", ttl);
 			return 0;
 		}
-		return recverr(fd, ttl);
+		return recverr(fd, ai, ttl);
 	}
 
 	printf("%2d:  send failed\n", ttl);
@@ -300,26 +370,46 @@ static void usage(void)
 	exit(-1);
 }
 
-int
-main(int argc, char **argv)
+
+int main(int argc, char **argv)
 {
 	struct addrinfo hints = {
-		.ai_family = AF_INET,
-		.ai_socktype = SOCK_RAW,
+		.ai_family = AF_UNSPEC,
+		.ai_socktype = SOCK_DGRAM,
+		.ai_protocol = IPPROTO_UDP,
 #ifdef USE_IDN
-		.ai_flags = AI_IDN | AI_CANONIDN,
+		.ai_flags = AI_IDN | AI_CANONNAME,
 #endif
 	};
-	struct addrinfo *ai;
+	struct addrinfo *ai, *result;
+	int ch;
 	int status;
 	int fd;
 	int on;
 	int ttl;
 	char *p;
-	int ch;
+	char pbuf[NI_MAXSERV];
+
+#ifdef USE_IDN
+	setlocale(LC_ALL, "");
+#endif
 
-	while ((ch = getopt(argc, argv, "nbh?l:m:p:")) != EOF) {
+	while ((ch = getopt(argc, argv, "46nbh?l:m:p:")) != EOF) {
 		switch(ch) {
+		case '4':
+			if (hints.ai_family != AF_UNSPEC) {
+				fprintf(stderr, "tracepath: Only one -4 or -6 option may be specified\n");
+				exit(2);
+			}
+			hints.ai_family = AF_INET;
+			break;
+		case '6':
+			if (hints.ai_family != AF_UNSPEC) {
+				fprintf(stderr, "tracepath: Only one -4 or -6 option may be specified\n");
+				exit(2);
+			}
+			hints.ai_family = AF_INET6;
+			break;
 		case 'n':
 			no_resolve = 1;
 			break;
@@ -355,13 +445,6 @@ main(int argc, char **argv)
 	if (argc != 1)
 		usage();
 
-	fd = socket(AF_INET, SOCK_DGRAM, 0);
-	if (fd < 0) {
-		perror("socket");
-		exit(1);
-	}
-	target.sin_family = AF_INET;
-
 	/* Backward compatiblity */
 	if (!base_port) {
 		p = strchr(argv[0], '/');
@@ -371,31 +454,87 @@ main(int argc, char **argv)
 		} else
 			base_port = 44444;
 	}
+	sprintf(pbuf, "%u", base_port);
 
-	status = getaddrinfo(argv[0], NULL, &hints, &ai);
+	status = getaddrinfo(argv[0], pbuf, &hints, &result);
 	if (status) {
 		fprintf(stderr, "tracepath: %s: %s\n", argv[0], gai_strerror(status));
 		exit(1);
 	}
 
-	memcpy(&target.sin_addr, &((struct sockaddr_in *) ai->ai_addr)->sin_addr, sizeof target.sin_addr);
-	freeaddrinfo(ai);
-
-	on = IP_PMTUDISC_PROBE;
-	if (setsockopt(fd, SOL_IP, IP_MTU_DISCOVER, &on, sizeof(on)) &&
-	    (on = IP_PMTUDISC_DO,
-	     setsockopt(fd, SOL_IP, IP_MTU_DISCOVER, &on, sizeof(on)))) {
-		perror("IP_MTU_DISCOVER");
-		exit(1);
+	fd = -1;
+	for (ai = result; ai; ai = ai->ai_next) {
+		if (ai->ai_family != AF_INET6 &&
+		    ai->ai_family != AF_INET)
+			continue;
+		fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+		if (fd < 0)
+			continue;
+		memcpy(&target, ai->ai_addr, sizeof(target));
+		targetlen = ai->ai_addrlen;
+		break;
 	}
-	on = 1;
-	if (setsockopt(fd, SOL_IP, IP_RECVERR, &on, sizeof(on))) {
-		perror("IP_RECVERR");
+	if (fd < 0) {
+		perror("socket/connect");
 		exit(1);
 	}
-	if (setsockopt(fd, SOL_IP, IP_RECVTTL, &on, sizeof(on))) {
-		perror("IP_RECVTTL");
-		exit(1);
+
+	switch (ai->ai_family) {
+	case AF_INET6:
+		overhead = 48;
+		if (!mtu)
+			mtu = 128000;
+		if (mtu <= overhead)
+			goto pktlen_error;
+
+		on = IPV6_PMTUDISC_DO;
+		if (setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &on, sizeof(on)) &&
+		    (on = IPV6_PMTUDISC_DO,
+		     setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &on, sizeof(on)))) {
+			perror("IPV6_MTU_DISCOVER");
+			exit(1);
+		}
+		on = 1;
+		if (setsockopt(fd, SOL_IPV6, IPV6_RECVERR, &on, sizeof(on))) {
+			perror("IPV6_RECVERR");
+			exit(1);
+		}
+		if (
+#ifdef IPV6_RECVHOPLIMIT
+		    setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &on, sizeof(on)) &&
+		    setsockopt(fd, SOL_IPV6, IPV6_2292HOPLIMIT, &on, sizeof(on))
+#else
+		    setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &on, sizeof(on))
+#endif
+		    ) {
+			perror("IPV6_HOPLIMIT");
+			exit(1);
+		}
+		if (!IN6_IS_ADDR_V4MAPPED(&(((struct sockaddr_in6 *)&target)->sin6_addr)))
+			break;
+		mapped = 1;
+		/*FALLTHROUGH*/
+	case AF_INET:
+		overhead = 28;
+		if (!mtu)
+			mtu = 65535;
+		if (mtu <= overhead)
+			goto pktlen_error;
+
+		on = IP_PMTUDISC_DO;
+		if (setsockopt(fd, SOL_IP, IP_MTU_DISCOVER, &on, sizeof(on))) {
+			perror("IP_MTU_DISCOVER");
+			exit(1);
+		}
+		on = 1;
+		if (setsockopt(fd, SOL_IP, IP_RECVERR, &on, sizeof(on))) {
+			perror("IP_RECVERR");
+			exit(1);
+		}
+		if (setsockopt(fd, SOL_IP, IP_RECVTTL, &on, sizeof(on))) {
+			perror("IP_RECVTTL");
+			exit(1);
+		}
 	}
 
 	pktbuf = malloc(mtu);
@@ -409,9 +548,20 @@ main(int argc, char **argv)
 		int i;
 
 		on = ttl;
-		if (setsockopt(fd, SOL_IP, IP_TTL, &on, sizeof(on))) {
-			perror("IP_TTL");
-			exit(1);
+		switch (ai->ai_family) {
+		case AF_INET6:
+			if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &on, sizeof(on))) {
+				perror("IPV6_UNICAST_HOPS");
+				exit(1);
+			}
+			if (!mapped)
+				break;
+			/*FALLTHROUGH*/
+		case AF_INET:
+			if (setsockopt(fd, SOL_IP, IP_TTL, &on, sizeof(on))) {
+				perror("IP_TTL");
+				exit(1);
+			}
 		}
 
 restart:
@@ -419,7 +569,7 @@ restart:
 			int old_mtu;
 
 			old_mtu = mtu;
-			res = probe_ttl(fd, ttl);
+			res = probe_ttl(fd, ai, ttl);
 			if (mtu != old_mtu)
 				goto restart;
 			if (res == 0)
@@ -432,7 +582,10 @@ restart:
 			printf("%2d:  no reply\n", ttl);
 	}
 	printf("     Too many hops: pmtu %d\n", mtu);
+
 done:
+	freeaddrinfo(result);
+
 	printf("     Resume: pmtu %d ", mtu);
 	if (hops_to>=0)
 		printf("hops %d ", hops_to);
@@ -440,4 +593,9 @@ done:
 		printf("back %d ", hops_from);
 	printf("\n");
 	exit(0);
+
+pktlen_error:
+	fprintf(stderr, "Error: pktlen must be > %d and <= %d\n",
+		overhead, INT_MAX);
+	exit(1);
 }
diff --git a/tracepath6.c b/tracepath6.c
deleted file mode 100644
index 2db6803..0000000
--- a/tracepath6.c
+++ /dev/null
@@ -1,591 +0,0 @@
-/*
- * tracepath6.c
- *
- *		This program is free software; you can redistribute it and/or
- *		modify it under the terms of the GNU General Public License
- *		as published by the Free Software Foundation; either version
- *		2 of the License, or (at your option) any later version.
- *
- * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <netinet/icmp6.h>
-
-#include <linux/types.h>
-#include <linux/errqueue.h>
-#include <errno.h>
-#include <string.h>
-#include <netdb.h>
-#include <limits.h>
-#include <resolv.h>
-#include <sys/time.h>
-#include <sys/uio.h>
-#include <arpa/inet.h>
-
-#ifdef USE_IDN
-#include <idna.h>
-#include <locale.h>
-#endif
-
-#ifndef SOL_IPV6
-#define SOL_IPV6 IPPROTO_IPV6
-#endif
-
-#ifndef IP_PMTUDISC_DO
-#define IP_PMTUDISC_DO		3
-#endif
-#ifndef IPV6_PMTUDISC_DO
-#define IPV6_PMTUDISC_DO	3
-#endif
-
-#define MAX_HOPS_LIMIT		255
-#define MAX_HOPS_DEFAULT	30
-
-struct hhistory
-{
-	int	hops;
-	struct timeval sendtime;
-};
-
-struct hhistory his[64];
-int hisptr;
-
-sa_family_t family = AF_INET6;
-struct sockaddr_storage target;
-socklen_t targetlen;
-__u16 base_port;
-int max_hops = MAX_HOPS_DEFAULT;
-
-int overhead;
-int mtu;
-void *pktbuf;
-int hops_to = -1;
-int hops_from = -1;
-int no_resolve = 0;
-int show_both = 0;
-int mapped;
-
-#define HOST_COLUMN_SIZE	52
-
-struct probehdr
-{
-	__u32 ttl;
-	struct timeval tv;
-};
-
-void data_wait(int fd)
-{
-	fd_set fds;
-	struct timeval tv;
-	FD_ZERO(&fds);
-	FD_SET(fd, &fds);
-	tv.tv_sec = 1;
-	tv.tv_usec = 0;
-	select(fd+1, &fds, NULL, NULL, &tv);
-}
-
-void print_host(const char *a, const char *b, int both)
-{
-	int plen;
-	plen = printf("%s", a);
-	if (both)
-		plen += printf(" (%s)", b);
-	if (plen >= HOST_COLUMN_SIZE)
-		plen = HOST_COLUMN_SIZE - 1;
-	printf("%*s", HOST_COLUMN_SIZE - plen, "");
-}
-
-int recverr(int fd, int ttl)
-{
-	int res;
-	struct probehdr rcvbuf;
-	char cbuf[512];
-	struct iovec  iov;
-	struct msghdr msg;
-	struct cmsghdr *cmsg;
-	struct sock_extended_err *e;
-	struct sockaddr_storage addr;
-	struct timeval tv;
-	struct timeval *rettv;
-	int slot = 0;
-	int rethops;
-	int sndhops;
-	int progress = -1;
-	int broken_router;
-
-restart:
-	memset(&rcvbuf, -1, sizeof(rcvbuf));
-	iov.iov_base = &rcvbuf;
-	iov.iov_len = sizeof(rcvbuf);
-	msg.msg_name = (caddr_t)&addr;
-	msg.msg_namelen = sizeof(addr);
-	msg.msg_iov = &iov;
-	msg.msg_iovlen = 1;
-	msg.msg_flags = 0;
-	msg.msg_control = cbuf;
-	msg.msg_controllen = sizeof(cbuf);
-
-	gettimeofday(&tv, NULL);
-	res = recvmsg(fd, &msg, MSG_ERRQUEUE);
-	if (res < 0) {
-		if (errno == EAGAIN)
-			return progress;
-		goto restart;
-	}
-
-	progress = mtu;
-
-	rethops = -1;
-	sndhops = -1;
-	e = NULL;
-	rettv = NULL;
-
-	slot = -base_port;
-	switch (family) {
-	case AF_INET6:
-		slot += ntohs(((struct sockaddr_in6 *)&addr)->sin6_port);
-		break;
-	case AF_INET:
-		slot += ntohs(((struct sockaddr_in *)&addr)->sin_port);
-		break;
-	}
-
-	if (slot >= 0 && slot < 63 && his[slot].hops) {
-		sndhops = his[slot].hops;
-		rettv = &his[slot].sendtime;
-		his[slot].hops = 0;
-	}
-	broken_router = 0;
-	if (res == sizeof(rcvbuf)) {
-		if (rcvbuf.ttl == 0 || rcvbuf.tv.tv_sec == 0)
-			broken_router = 1;
-		else {
-			sndhops = rcvbuf.ttl;
-			rettv = &rcvbuf.tv;
-		}
-	}
-
-	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-		switch (cmsg->cmsg_level) {
-		case SOL_IPV6:
-			switch(cmsg->cmsg_type) {
-			case IPV6_RECVERR:
-				e = (struct sock_extended_err *)CMSG_DATA(cmsg);
-				break;
-			case IPV6_HOPLIMIT:
-#ifdef IPV6_2292HOPLIMIT
-			case IPV6_2292HOPLIMIT:
-#endif
-				memcpy(&rethops, CMSG_DATA(cmsg), sizeof(rethops));
-				break;
-			default:
-				printf("cmsg6:%d\n ", cmsg->cmsg_type);
-			}
-			break;
-		case SOL_IP:
-			switch(cmsg->cmsg_type) {
-			case IP_RECVERR:
-				e = (struct sock_extended_err *)CMSG_DATA(cmsg);
-				break;
-			case IP_TTL:
-				rethops = *(__u8*)CMSG_DATA(cmsg);
-				break;
-			default:
-				printf("cmsg4:%d\n ", cmsg->cmsg_type);
-			}
-		}
-	}
-	if (e == NULL) {
-		printf("no info\n");
-		return 0;
-	}
-	if (e->ee_origin == SO_EE_ORIGIN_LOCAL)
-		printf("%2d?: %-32s ", ttl, "[LOCALHOST]");
-	else if (e->ee_origin == SO_EE_ORIGIN_ICMP6 ||
-		 e->ee_origin == SO_EE_ORIGIN_ICMP) {
-		char abuf[NI_MAXHOST], hbuf[NI_MAXHOST];
-		struct sockaddr *sa = (struct sockaddr *)(e + 1);
-		socklen_t salen;
-
-		if (sndhops>0)
-			printf("%2d:  ", sndhops);
-		else
-			printf("%2d?: ", ttl);
-
-		switch (sa->sa_family) {
-		case AF_INET6:
-			salen = sizeof(struct sockaddr_in6);
-			break;
-		case AF_INET:
-			salen = sizeof(struct sockaddr_in);
-			break;
-		default:
-			salen = 0;
-		}
-
-		if (no_resolve || show_both) {
-			if (getnameinfo(sa, salen,
-					abuf, sizeof(abuf), NULL, 0,
-					NI_NUMERICHOST))
-				strcpy(abuf, "???");
-		} else
-			abuf[0] = 0;
-
-		if (!no_resolve || show_both) {
-			fflush(stdout);
-			if (getnameinfo(sa, salen,
-					hbuf, sizeof(hbuf), NULL, 0,
-					0
-#ifdef USE_IDN
-					| NI_IDN
-#endif
-				        ))
-				strcpy(hbuf, "???");
-		} else
-			hbuf[0] = 0;
-
-		if (no_resolve)
-			print_host(abuf, hbuf, show_both);
-		else
-			print_host(hbuf, abuf, show_both);
-	}
-
-	if (rettv) {
-		int diff = (tv.tv_sec-rettv->tv_sec)*1000000+(tv.tv_usec-rettv->tv_usec);
-		printf("%3d.%03dms ", diff/1000, diff%1000);
-		if (broken_router)
-			printf("(This broken router returned corrupted payload) ");
-	}
-
-	if (rethops<=64)
-		rethops = 65-rethops;
-	else if (rethops<=128)
-		rethops = 129-rethops;
-	else
-		rethops = 256-rethops;
-
-	switch (e->ee_errno) {
-	case ETIMEDOUT:
-		printf("\n");
-		break;
-	case EMSGSIZE:
-		printf("pmtu %d\n", e->ee_info);
-		mtu = e->ee_info;
-		progress = mtu;
-		break;
-	case ECONNREFUSED:
-		printf("reached\n");
-		hops_to = sndhops<0 ? ttl : sndhops;
-		hops_from = rethops;
-		return 0;
-	case EPROTO:
-		printf("!P\n");
-		return 0;
-	case EHOSTUNREACH:
-		if ((e->ee_origin == SO_EE_ORIGIN_ICMP &&
-		     e->ee_type == 11 &&
-		     e->ee_code == 0) ||
-		    (e->ee_origin == SO_EE_ORIGIN_ICMP6 &&
-		     e->ee_type == 3 &&
-		     e->ee_code == 0)) {
-			if (rethops>=0) {
-				if (sndhops>=0 && rethops != sndhops)
-					printf("asymm %2d ", rethops);
-				else if (sndhops<0 && rethops != ttl)
-					printf("asymm %2d ", rethops);
-			}
-			printf("\n");
-			break;
-		}
-		printf("!H\n");
-		return 0;
-	case ENETUNREACH:
-		printf("!N\n");
-		return 0;
-	case EACCES:
-		printf("!A\n");
-		return 0;
-	default:
-		printf("\n");
-		errno = e->ee_errno;
-		perror("NET ERROR");
-		return 0;
-	}
-	goto restart;
-}
-
-int probe_ttl(int fd, int ttl)
-{
-	int i;
-	struct probehdr *hdr = pktbuf;
-
-	memset(pktbuf, 0, mtu);
-restart:
-
-	for (i=0; i<10; i++) {
-		int res;
-
-		hdr->ttl = ttl;
-		switch (family) {
-		case AF_INET6:
-			((struct sockaddr_in6 *)&target)->sin6_port = htons(base_port + hisptr);
-			break;
-		case AF_INET:
-			((struct sockaddr_in *)&target)->sin_port = htons(base_port + hisptr);
-			break;
-		}
-		gettimeofday(&hdr->tv, NULL);
-		his[hisptr].hops = ttl;
-		his[hisptr].sendtime = hdr->tv;
-		if (sendto(fd, pktbuf, mtu-overhead, 0, (struct sockaddr *)&target, targetlen) > 0)
-			break;
-		res = recverr(fd, ttl);
-		his[hisptr].hops = 0;
-		if (res==0)
-			return 0;
-		if (res > 0)
-			goto restart;
-	}
-	hisptr = (hisptr + 1) & 63;
-
-	if (i<10) {
-		data_wait(fd);
-		if (recv(fd, pktbuf, mtu, MSG_DONTWAIT) > 0) {
-			printf("%2d?: reply received 8)\n", ttl);
-			return 0;
-		}
-		return recverr(fd, ttl);
-	}
-
-	printf("%2d:  send failed\n", ttl);
-	return 0;
-}
-
-static void usage(void) __attribute((noreturn));
-
-static void usage(void)
-{
-	fprintf(stderr, "Usage: tracepath6 [-n] [-b] [-l <len>] [-p port] <destination>\n");
-	exit(-1);
-}
-
-
-int main(int argc, char **argv)
-{
-	int fd;
-	int on;
-	int ttl;
-	char *p;
-	struct addrinfo hints = {
-		.ai_family = family,
-		.ai_socktype = SOCK_DGRAM,
-		.ai_protocol = IPPROTO_UDP,
-#ifdef USE_IDN
-		.ai_flags = AI_IDN | AI_CANONNAME,
-#endif
-	};
-	struct addrinfo *ai, *result;
-	int ch;
-	int status;
-	char pbuf[NI_MAXSERV];
-
-#ifdef USE_IDN
-	setlocale(LC_ALL, "");
-#endif
-
-	while ((ch = getopt(argc, argv, "nbh?l:m:p:")) != EOF) {
-		switch(ch) {
-		case 'n':
-			no_resolve = 1;
-			break;
-		case 'b':
-			show_both = 1;
-			break;
-		case 'l':
-			mtu = atoi(optarg);
-			break;
-		case 'm':
-			max_hops = atoi(optarg);
-			if (max_hops < 0 || max_hops > MAX_HOPS_LIMIT) {
-				fprintf(stderr,
-					"Error: max hops must be 0 .. %d (inclusive).\n",
-					MAX_HOPS_LIMIT);
-			}
-			break;
-		case 'p':
-			base_port = atoi(optarg);
-			break;
-		default:
-			usage();
-		}
-	}
-
-	argc -= optind;
-	argv += optind;
-
-	if (argc != 1)
-		usage();
-
-	/* Backward compatiblity */
-	if (!base_port) {
-		p = strchr(argv[0], '/');
-		if (p) {
-			*p = 0;
-			base_port = (unsigned)atoi(p+1);
-		} else {
-			base_port = 44444;
-		}
-	}
-	sprintf(pbuf, "%u", base_port);
-
-	status = getaddrinfo(argv[0], pbuf, &hints, &result);
-	if (status) {
-		fprintf(stderr, "tracepath6: %s: %s\n", argv[0], gai_strerror(status));
-		exit(1);
-	}
-
-	fd = -1;
-	for (ai = result; ai; ai = ai->ai_next) {
-		/* sanity check */
-		if (family && ai->ai_family != family)
-			continue;
-		if (ai->ai_family != AF_INET6 &&
-		    ai->ai_family != AF_INET)
-			continue;
-		family = ai->ai_family;
-		fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
-		if (fd < 0)
-			continue;
-		memcpy(&target, ai->ai_addr, sizeof(target));
-		targetlen = ai->ai_addrlen;
-		break;
-	}
-	if (fd < 0) {
-		perror("socket/connect");
-		exit(1);
-	}
-	freeaddrinfo(result);
-
-	switch (family) {
-	case AF_INET6:
-		overhead = 48;
-		if (!mtu)
-			mtu = 128000;
-		if (mtu <= overhead)
-			goto pktlen_error;
-
-		on = IPV6_PMTUDISC_DO;
-		if (setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &on, sizeof(on)) &&
-		    (on = IPV6_PMTUDISC_DO,
-		     setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &on, sizeof(on)))) {
-			perror("IPV6_MTU_DISCOVER");
-			exit(1);
-		}
-		on = 1;
-		if (setsockopt(fd, SOL_IPV6, IPV6_RECVERR, &on, sizeof(on))) {
-			perror("IPV6_RECVERR");
-			exit(1);
-		}
-		if (
-#ifdef IPV6_RECVHOPLIMIT
-		    setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &on, sizeof(on)) &&
-		    setsockopt(fd, SOL_IPV6, IPV6_2292HOPLIMIT, &on, sizeof(on))
-#else
-		    setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &on, sizeof(on))
-#endif
-		    ) {
-			perror("IPV6_HOPLIMIT");
-			exit(1);
-		}
-		if (!IN6_IS_ADDR_V4MAPPED(&(((struct sockaddr_in6 *)&target)->sin6_addr)))
-			break;
-		mapped = 1;
-		/*FALLTHROUGH*/
-	case AF_INET:
-		overhead = 28;
-		if (!mtu)
-			mtu = 65535;
-		if (mtu <= overhead)
-			goto pktlen_error;
-
-		on = IP_PMTUDISC_DO;
-		if (setsockopt(fd, SOL_IP, IP_MTU_DISCOVER, &on, sizeof(on))) {
-			perror("IP_MTU_DISCOVER");
-			exit(1);
-		}
-		on = 1;
-		if (setsockopt(fd, SOL_IP, IP_RECVERR, &on, sizeof(on))) {
-			perror("IP_RECVERR");
-			exit(1);
-		}
-		if (setsockopt(fd, SOL_IP, IP_RECVTTL, &on, sizeof(on))) {
-			perror("IP_RECVTTL");
-			exit(1);
-		}
-	}
-
-	pktbuf = malloc(mtu);
-	if (!pktbuf) {
-		perror("malloc");
-		exit(1);
-	}
-
-	for (ttl = 1; ttl <= max_hops; ttl++) {
-		int res;
-		int i;
-
-		on = ttl;
-		switch (family) {
-		case AF_INET6:
-			if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &on, sizeof(on))) {
-				perror("IPV6_UNICAST_HOPS");
-				exit(1);
-			}
-			if (!mapped)
-				break;
-			/*FALLTHROUGH*/
-		case AF_INET:
-			if (setsockopt(fd, SOL_IP, IP_TTL, &on, sizeof(on))) {
-				perror("IP_TTL");
-				exit(1);
-			}
-		}
-
-restart:
-		for (i=0; i<3; i++) {
-			int old_mtu;
-
-			old_mtu = mtu;
-			res = probe_ttl(fd, ttl);
-			if (mtu != old_mtu)
-				goto restart;
-			if (res == 0)
-				goto done;
-			if (res > 0)
-				break;
-		}
-
-		if (res < 0)
-			printf("%2d:  no reply\n", ttl);
-	}
-	printf("     Too many hops: pmtu %d\n", mtu);
-
-done:
-	printf("     Resume: pmtu %d ", mtu);
-	if (hops_to>=0)
-		printf("hops %d ", hops_to);
-	if (hops_from>=0)
-		printf("back %d ", hops_from);
-	printf("\n");
-	exit(0);
-
-pktlen_error:
-	fprintf(stderr, "Error: pktlen must be > %d and <= %d\n",
-		overhead, INT_MAX);
-	exit(1);
-}