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70726640b

Denys Vlasenko

2020-12-12

SUCCESS Duration: 152s

Subject

traceroute: code shrink

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 +35 -49

networking/traceroute.c+35 -49

@@ -389,6 +389,8 @@ struct globals {
	struct outdata_t *outdata;

	len_and_sockaddr *dest_lsa;
+	len_and_sockaddr from_lsa; / response came from this address */
+	struct sockaddr to; / response came to this (local) address */
	int packlen; /* total length of packet */
	int pmtu; /* Path MTU Discovery (RFC1191) */
	uint32_t ident;
@@ -442,7 +444,7 @@ struct globals {
	*/

	static int
-	wait_for_reply(len_and_sockaddr from_lsa, struct sockaddr to, unsigned timestamp_us, int left_ms)
+	wait_for_reply(unsigned timestamp_us, int left_ms)
	{
	struct pollfd pfd[1];
	int read_len = 0;
@@ -455,7 +457,7 @@ wait_for_reply(len_and_sockaddr from_lsa, struct sockaddr to, unsigned *timest
	read_len = recv_from_to(rcvsock,
	recv_pkt, sizeof(recv_pkt),
	/flags:/ MSG_DONTWAIT,
-	&from_lsa->u.sa, to, from_lsa->len);
+	&G.from_lsa->u.sa, G.to, G.from_lsa->len);
	t = monotonic_us();
	left_ms -= (t - timestamp_us) / 1000;
	*timestamp_us = t;
@@ -598,7 +600,7 @@ pr_type(unsigned char t)
	packet4_ok(read_len, seq)
	#endif
	static int
-	packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
+	packet4_ok(int read_len, int seq)
	{
	const struct icmp *icp;
	unsigned char type, code;
@@ -616,7 +618,7 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
	#if ENABLE_FEATURE_TRACEROUTE_VERBOSE
	if (verbose)
	printf("packet too short (%d bytes) from %s\n", read_len,
-	inet_ntoa(from->sin_addr));
+	inet_ntoa(G.from_lsa->u.sin.sin_addr));
	#endif
	return 0;
	}
@@ -680,7 +682,7 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
	uint32_t lp = (uint32_t )&icp->icmp_ip;

	printf("\n%d bytes from %s",
-	read_len, inet_ntoa(from->sin_addr));
+	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",
	inet_ntoa(ip->ip_dst),
@@ -694,14 +696,8 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq)

	#if ENABLE_TRACEROUTE6

-	# if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
-	#define packet6_ok(read_len, from_lsa, to, seq) \
-	packet6_ok(read_len, from_lsa, seq)
-	# endif
	static int
-	packet6_ok(int read_len, const struct sockaddr_in6 *from,
-	struct sockaddr *to,
-	int seq)
+	packet6_ok(int read_len, int seq)
	{
	const struct icmp6_hdr *icp;
	unsigned char type, code;
@@ -757,21 +753,18 @@ packet6_ok(int read_len, const struct sockaddr_in6 *from,

	# if ENABLE_FEATURE_TRACEROUTE_VERBOSE
	if (verbose) {
-	# ifndef MAXHOSTNAMELEN
-	# define MAXHOSTNAMELEN 80
-	# endif
	unsigned char *p;
-	char pa[MAXHOSTNAMELEN];
+	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",
	read_len,
-	inet_ntop(AF_INET6, &from->sin6_addr, pa, sizeof(pa)));
+	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*)to)->sin6_addr, pa, sizeof(pa)),
+	inet_ntop(AF_INET6, &((struct sockaddr_in6*)G.to)->sin6_addr, pa, sizeof(pa)),
	type, pr_type(type), icp->icmp6_code);

	read_len -= sizeof(struct icmp6_hdr);
@@ -790,29 +783,21 @@ packet6_ok(int read_len, const struct sockaddr_in6 *from,

	return 0;
	}
-	# if !ENABLE_FEATURE_TRACEROUTE_VERBOSE
-	#define packet_ok(read_len, from_lsa, to, seq) \
-	packet_ok(read_len, from_lsa, seq)
-	# endif
+
	static int
-	packet_ok(int read_len, len_and_sockaddr *from_lsa,
-	struct sockaddr *to,
-	int seq)
+	packet_ok(int read_len, int seq)
	{
-	if (from_lsa->u.sa.sa_family == AF_INET)
-	return packet4_ok(read_len, &from_lsa->u.sin, seq);
-	return packet6_ok(read_len, &from_lsa->u.sin6, to, seq);
+	if (G.from_lsa->u.sa.sa_family == AF_INET)
+	return packet4_ok(read_len, seq);
+	return packet6_ok(read_len, seq);
	}

	#else /* !ENABLE_TRACEROUTE6 */

	static ALWAYS_INLINE int
-	packet_ok(int read_len,
-	len_and_sockaddr *from_lsa IF_NOT_FEATURE_TRACEROUTE_VERBOSE(UNUSED_PARAM),
-	struct sockaddr *to UNUSED_PARAM,
-	int seq)
+	packet_ok(int read_len, int seq)
	{
-	return packet4_ok(read_len, &from_lsa->u.sin, seq);
+	return packet4_ok(read_len, seq);
	}

	#endif
@@ -845,19 +830,19 @@ print_inetname(const struct sockaddr *from)
	}

	static void
-	print(int read_len, const struct sockaddr from, const struct sockaddr to)
+	print(int read_len)
	{
-	print_inetname(from);
+	print_inetname(&G.from_lsa->u.sa);

	if (verbose) {
-	char *ina = xmalloc_sockaddr2dotted_noport(to);
+	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 (to->sa_family == AF_INET6) {
+	if (G.to->sa_family == AF_INET6) {
	/* read_len -= sizeof(struct ip6_hdr); - WRONG! */
	} else
	#endif
@@ -910,9 +895,7 @@ common_traceroute_main(int op, char **argv)
	#endif
	int ttl;
	int seq;
-	len_and_sockaddr *from_lsa;
	struct sockaddr *lastaddr;
-	struct sockaddr *to;

	/* Ensure the socket fds won't be 0, 1 or 2 */
	bb_sanitize_stdio();
@@ -1121,9 +1104,9 @@ common_traceroute_main(int op, char **argv)
	printf(" from %s", source);
	printf(", %d hops max, %d byte packets\n", max_ttl, packlen);

-	from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len);
	lastaddr = xzalloc(dest_lsa->len);
-	to = xzalloc(dest_lsa->len);
+	G.from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len);
+	G.to = xzalloc(dest_lsa->len);
	seq = 0;
	for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
	int probe;
@@ -1146,7 +1129,10 @@ common_traceroute_main(int op, char **argv)
	t2 = t1 = monotonic_us();

	left_ms = waittime * 1000;
-	while ((read_len = wait_for_reply(from_lsa, to, &t2, &left_ms)) != 0) {
+	/* NB: wait_for_reply() fills "G.from_lsa" and "G.to"
+	* with "where it came from" and "to which local address it arrived".
+	*/
+	while ((read_len = wait_for_reply(&t2, &left_ms)) != 0) {
	int icmp_code;

	/* Recv'ed a packet, or read error */
@@ -1154,22 +1140,22 @@ common_traceroute_main(int op, char **argv)

	if (read_len < 0)
	continue;
-	icmp_code = packet_ok(read_len, from_lsa, to, seq);
+	icmp_code = packet_ok(read_len, seq);
	/* Skip short packet */
	if (icmp_code == 0)
	continue;

	if (!gotlastaddr
-	\|\| (memcmp(lastaddr, &from_lsa->u.sa, from_lsa->len) != 0)
+	\|\| (memcmp(lastaddr, &G.from_lsa->u.sa, G.from_lsa->len) != 0)
	) {
-	print(read_len, &from_lsa->u.sa, to);
-	memcpy(lastaddr, &from_lsa->u.sa, from_lsa->len);
+	print(read_len);
+	memcpy(lastaddr, &G.from_lsa->u.sa, G.from_lsa->len);
	gotlastaddr = 1;
	}

	print_delta_ms(t1, t2);

-	if (from_lsa->u.sa.sa_family == AF_INET) {
+	if (G.from_lsa->u.sa.sa_family == AF_INET) {
	if (op & OPT_TTL_FLAG) {
	struct ip ip = (struct ip )recv_pkt;
	printf(" (%d)", ip->ip_ttl);
@@ -1276,9 +1262,9 @@ common_traceroute_main(int op, char **argv)
	}

	if (ENABLE_FEATURE_CLEAN_UP) {
-	free(to);
+	free(G.to);
	free(lastaddr);
-	free(from_lsa);
+	free(G.from_lsa);
	}

	return 0;