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df5c5394b

Denys Vlasenko

2020-12-12

SUCCESS Duration: 150s

Subject

traceroute: set IP_PKTINFO to see correct local IP of received pkt (fixes -v display)

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

networking/traceroute.c +41 -64

networking/traceroute.c+41 -64

@@ -413,7 +413,6 @@ struct globals {
	#define port (G.port )
	#define waittime (G.waittime )
	#define recv_pkt (G.recv_pkt )
-	#define gwlist (G.gwlist )
	#define INIT_G() do { \
	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
	} while (0)
@@ -683,12 +682,15 @@ packet4_ok(int read_len, int seq)
	int i;
	uint32_t lp = (uint32_t )&icp->icmp_ip;

-	printf("\n%d bytes from %s",
-	read_len, inet_ntoa(G.from_lsa->u.sin.sin_addr));
-	/* Two separate printf() because inet_ntoa() returns static string */
-	printf(" to %s: icmp type %d (%s) code %d\n",
+	printf("\n%d bytes from %s to %s: icmp type %d (%s) code %d\n",
+	read_len,
+	/* inet_ntoa(G.from_lsa->u.sin.sin_addr) - two calls of inet_ntoa()
+	* are unsafe (use the same buffer), using this instead:
+	*/
+	auto_string(xmalloc_sockaddr2dotted_noport(&G.from_lsa->u.sa)),
	inet_ntoa(ip->ip_dst),
-	type, pr_type(type), icp->icmp_code);
+	type, pr_type(type), icp->icmp_code
+	);
	for (i = 4; i < read_len; i += sizeof(*lp))
	printf("%2d: x%8.8x\n", i, *lp++);
	}
@@ -756,19 +758,16 @@ packet6_ok(int read_len, int seq)
	# if ENABLE_FEATURE_TRACEROUTE_VERBOSE
	if (verbose) {
	unsigned char *p;
-	char pa[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff") + 4];
	int i;

	p = (unsigned char *) (icp + 1);

-	printf("\n%d bytes from %s",
+	printf("\n%d bytes from %s to %s: icmp type %d (%s) code %d\n",
	read_len,
-	inet_ntop(AF_INET6, &G.from_lsa->u.sin6.sin6_addr, pa, sizeof(pa)));
-	/* Two printf() instead of one - reuse string constants */
-	printf(" to %s: icmp type %d (%s) code %d\n",
-	inet_ntop(AF_INET6, &((struct sockaddr_in6*)G.to)->sin6_addr, pa, sizeof(pa)),
-	type, pr_type(type), icp->icmp6_code);
-
+	auto_string(xmalloc_sockaddr2dotted_noport(&G.from_lsa->u.sa)),
+	auto_string(xmalloc_sockaddr2dotted_noport(G.to)),
+	type, pr_type(type), icp->icmp6_code
+	);
	read_len -= sizeof(struct icmp6_hdr);
	for (i = 0; i < read_len; i++) {
	if (i % 16 == 0)
@@ -796,55 +795,36 @@ packet_ok(int read_len, int seq)

	#else /* !ENABLE_TRACEROUTE6 */

-	static ALWAYS_INLINE int
-	packet_ok(int read_len, int seq)
-	{
-	return packet4_ok(read_len, seq);
-	}
+	# define packet_ok(read_len, seq) packet4_ok(read_len, seq)

	#endif

-	/*
-	* Construct an Internet address representation.
-	* If the -n flag has been supplied, give
-	* numeric value, otherwise try for symbolic name.
-	*/
	static void
-	print_inetname(const struct sockaddr *from)
+	print(int read_len)
	{
-	char *ina = xmalloc_sockaddr2dotted_noport(from);
+	char *ina = auto_string(xmalloc_sockaddr2dotted_noport(&G.from_lsa->u.sa));

	if (option_mask32 & OPT_ADDR_NUM) {
	printf(" %s", ina);
	} else {
	char *n = NULL;
-
-	if (from->sa_family != AF_INET
-	\|\| ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
+	if (G.from_lsa->u.sa.sa_family != AF_INET
+	\|\| G.from_lsa->u.sin.sin_addr.s_addr != INADDR_ANY
	) {
	/* Try to reverse resolve if it is not 0.0.0.0 */
-	n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
+	n = auto_string(xmalloc_sockaddr2host_noport(&G.from_lsa->u.sa));
	}
	printf(" %s (%s)", (n ? n : ina), ina);
-	free(n);
	}
-	free(ina);
-	}
-
-	static void
-	print(int read_len)
-	{
-	print_inetname(&G.from_lsa->u.sa);

	if (verbose) {
-	char *ina = xmalloc_sockaddr2dotted_noport(G.to);
	#if ENABLE_TRACEROUTE6
	/* NB: reads from (AF_INET, SOCK_RAW, IPPROTO_ICMP) socket
	* return the entire IP packet (IOW: they do not strip IP header).
	* Reads from (AF_INET6, SOCK_RAW, IPPROTO_ICMPV6) do strip IPv6
	* header and return only ICMP6 packet. Weird.
	*/
-	if (G.to->sa_family == AF_INET6) {
+	if (G.from_lsa->u.sa.sa_family == AF_INET6) {
	/* read_len -= sizeof(struct ip6_hdr); - WRONG! */
	} else
	#endif
@@ -852,8 +832,9 @@ print(int read_len)
	struct ip ip4packet = (struct ip)recv_pkt;
	read_len -= ip4packet->ip_hl << 2;
	}
-	printf(" %d bytes to %s", read_len, ina);
-	free(ina);
+	printf(" %d bytes to %s", read_len,
+	auto_string(xmalloc_sockaddr2dotted_noport(G.to))
+	);
	}
	}

@@ -870,10 +851,6 @@ print_delta_ms(unsigned t1p, unsigned t2p)
	static NOINLINE void
	traceroute_init(int op, char **argv)
	{
-	int minpacket;
-	#ifdef IP_TOS
-	int tos = 0;
-	#endif
	char *source;
	char *device;
	char *tos_str;
@@ -911,10 +888,6 @@ traceroute_init(int op, char **argv)
	#if 0 /* IGNORED */
	if (op & OPT_IP_CHKSUM)
	bb_error_msg("warning: ip checksums disabled");
-	#endif
-	#ifdef IP_TOS
-	if (op & OPT_TOS)
-	tos = xatou_range(tos_str, 0, 255);
	#endif
	if (op & OPT_MAX_TTL)
	G.max_ttl = xatou_range(max_ttl_str, 1, 255);
@@ -930,11 +903,11 @@ traceroute_init(int op, char **argv)
	G.first_ttl = xatou_range(first_ttl_str, 1, G.max_ttl);

	/* Process destination and optional packet size */
-	minpacket = sizeof(struct ip)
+	packlen = sizeof(struct ip)
	+ sizeof(struct udphdr)
	+ sizeof(struct outdata_t);
	if (op & OPT_USE_ICMP) {
-	minpacket = sizeof(struct ip)
+	packlen = sizeof(struct ip)
	+ SIZEOF_ICMP_HDR
	+ sizeof(struct outdata_t);
	port = 0; /* on ICMP6 sockets, sendto(ipv6.nonzero_port) throws EINVAL */
@@ -948,11 +921,11 @@ traceroute_init(int op, char **argv)
	dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
	af = dest_lsa->u.sa.sa_family;
	if (af == AF_INET6) {
-	minpacket = sizeof(struct ip6_hdr)
+	packlen = sizeof(struct ip6_hdr)
	+ sizeof(struct udphdr)
	+ sizeof(struct outdata6_t);
	if (op & OPT_USE_ICMP)
-	minpacket = sizeof(struct ip6_hdr)
+	packlen = sizeof(struct ip6_hdr)
	+ SIZEOF_ICMP_HDR
	+ sizeof(struct outdata6_t);
	}
@@ -961,19 +934,20 @@ traceroute_init(int op, char **argv)
	#endif
	G.from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len);
	G.to = xzalloc(dest_lsa->len);
-
-	packlen = minpacket;
	if (argv[1])
-	packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
+	packlen = xatoul_range(argv[1], packlen, 32 * 1024);

	#if ENABLE_TRACEROUTE6
	if (af == AF_INET6) {
	xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
-	setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO); //why?
+	/* want recvmsg to report target local address (for -v) */
+	setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO);
	} else
	#endif
	{
	xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
+	/* want recvmsg to report target local address (for -v) */
+	setsockopt_1(rcvsock, IPPROTO_IP, IP_PKTINFO);
	}

	#if TRACEROUTE_SO_DEBUG
@@ -1010,8 +984,10 @@ traceroute_init(int op, char **argv)
	}
	#endif
	#ifdef IP_TOS
-	if ((op & OPT_TOS) && setsockopt_int(sndsock, IPPROTO_IP, IP_TOS, tos) != 0) {
-	bb_perror_msg_and_die("setsockopt(%s) %d", "TOS", tos);
+	if (op & OPT_TOS) {
+	int tos = xatou_range(tos_str, 0, 255);
+	if (setsockopt_int(sndsock, IPPROTO_IP, IP_TOS, tos) != 0)
+	bb_perror_msg_and_die("setsockopt(%s,%d)", "TOS", tos);
	}
	#endif
	#ifdef IP_DONTFRAG
@@ -1070,7 +1046,8 @@ traceroute_init(int op, char **argv)
	//TODO: we can query source port we bound to,
	// and check it in replies... if we care enough
	xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
-	free(source_lsa);
+	if (ENABLE_FEATURE_CLEAN_UP)
+	free(source_lsa);
	}
	#if ENABLE_TRACEROUTE6
	else if (af == AF_INET6) {
@@ -1087,7 +1064,8 @@ traceroute_init(int op, char **argv)
	/* bind our recv socket to this IP (but not port) */
	set_nport(&source_lsa->u.sa, 0);
	xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
-	free(source_lsa);
+	if (ENABLE_FEATURE_CLEAN_UP)
+	free(source_lsa);
	}
	#endif

@@ -1097,9 +1075,8 @@ traceroute_init(int op, char **argv)

	dest_str = xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa);
	printf("traceroute to %s (%s)", argv[0], dest_str);
-	if (ENABLE_FEATURE_CLEAN_UP) {
+	if (ENABLE_FEATURE_CLEAN_UP)
	free(dest_str);
-	}

	if (op & OPT_SOURCE)
	printf(" from %s", source);