nslookup: full circle. Here we started IPv6 work. Use "new API"

and thus save a few bytes.

3 files changed, 132 insertions, 48 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 57531e4..e419937 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -278,12 +278,12 @@ extern off_t xlseek(int fd, off_t offset, int whence);
 extern off_t fdlength(int fd);
 
 
-extern int xsocket(int domain, int type, int protocol);
-extern void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen);
-extern void xlisten(int s, int backlog);
-extern void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen);
-extern int setsockopt_reuseaddr(int fd);
-extern int setsockopt_broadcast(int fd);
+int xsocket(int domain, int type, int protocol);
+void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen);
+void xlisten(int s, int backlog);
+void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen);
+int setsockopt_reuseaddr(int fd);
+int setsockopt_broadcast(int fd);
 /* NB: returns port in host byte order */
 unsigned bb_lookup_port(const char *port, const char *protocol, unsigned default_port);
 typedef struct len_and_sockaddr {
@@ -303,34 +303,39 @@ int xsocket_stream(len_and_sockaddr **lsap);
  * numeric IP ("N.N.N.N") or numeric IPv6 address,
  * and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT").
  * If there is no suffix, port argument is used */
-extern int create_and_bind_stream_or_die(const char *bindaddr, int port);
+int create_and_bind_stream_or_die(const char *bindaddr, int port);
 /* Create client TCP socket connected to peer:port. Peer cannot be NULL.
  * Peer can be numeric IP ("N.N.N.N"), numeric IPv6 address or hostname,
  * and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT").
  * If there is no suffix, port argument is used */
-extern int create_and_connect_stream_or_die(const char *peer, int port);
+int create_and_connect_stream_or_die(const char *peer, int port);
 /* Connect to peer identified by lsa */
-extern int xconnect_stream(const len_and_sockaddr *lsa);
+int xconnect_stream(const len_and_sockaddr *lsa);
 /* Return malloc'ed len_and_sockaddr with socket address of host:port
  * Currently will return IPv4 or IPv6 sockaddrs only
  * (depending on host), but in theory nothing prevents e.g.
  * UNIX socket address being returned, IPX sockaddr etc... */
-extern len_and_sockaddr* host2sockaddr(const char *host, int port);
+len_and_sockaddr* host2sockaddr(const char *host, int port);
 /* Assign sin[6]_port member if the socket is of corresponding type,
  * otherwise no-op. Useful for ftp.
  * NB: does NOT do htons() internally, just direct assignment. */
-extern void set_nport(len_and_sockaddr *lsa, unsigned port);
+void set_nport(len_and_sockaddr *lsa, unsigned port);
 /* Retrieve sin[6]_port or return -1 for non-INET[6] lsa's */
-extern int get_nport(len_and_sockaddr *lsa);
-extern char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen);
-extern char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen);
+int get_nport(len_and_sockaddr *lsa);
+/* Reverse DNS */
+char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen);
+/* This one deosn't fall back to dotted IP and do not append :PORTNUM */
+char* xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa, socklen_t salen);
+/* inet_[ap]ton on steroids */
+char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen);
+char* xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa, socklen_t salen);
 // "old" (ipv4 only) API
 //void bb_lookup_host(struct sockaddr_in *s_in, const char *host);
-//extern int xconnect_tcp_v4(struct sockaddr_in *s_addr);
+//int xconnect_tcp_v4(struct sockaddr_in *s_addr);
 // users: traceroute.c hostname.c ifconfig.c ping.c
-extern struct hostent *xgethostbyname(const char *name);
+struct hostent *xgethostbyname(const char *name);
 // ping6 is the only user - convert to new API
-extern struct hostent *xgethostbyname2(const char *name, int af);
+struct hostent *xgethostbyname2(const char *name, int af);
 
 
 extern char *xstrdup(const char *s);
diff --git a/libbb/xconnect.c b/libbb/xconnect.c
index 0addda1..188837e 100644
--- a/libbb/xconnect.c
+++ b/libbb/xconnect.c
@@ -245,25 +245,36 @@ int xconnect_stream(const len_and_sockaddr *lsa)
 	return fd;
 }
 
+/* We hijack this constant to mean something else */
+/* It doesn't hurt because we will add this bit anyway */
+#define IGNORE_PORT NI_NUMERICSERV
 static char* sockaddr2str(const struct sockaddr *sa, socklen_t salen, int flags)
 {
 	char host[128];
 	char serv[16];
 	int rc = getnameinfo(sa, salen,
 			host, sizeof(host),
+	/* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */
 			serv, sizeof(serv),
 			/* do not resolve port# into service _name_ */
 			flags | NI_NUMERICSERV
 	);
 	if (rc)
 		return NULL;
+	if (flags & IGNORE_PORT)
+		return xstrdup(host);
 #if ENABLE_FEATURE_IPV6
-	if (sa->sa_family == AF_INET6)
-		return xasprintf("[%s]:%s", host, serv);
+	if (sa->sa_family == AF_INET6) {
+		if (strchr(host, ':')) /* heh, it's not a resolved hostname */
+			return xasprintf("[%s]:%s", host, serv);
+		/*return xasprintf("%s:%s", host, serv);*/
+		/* - fall through instead */
+	}
 #endif
 	/* For now we don't support anything else, so it has to be INET */
 	/*if (sa->sa_family == AF_INET)*/
 		return xasprintf("%s:%s", host, serv);
+	/*return xstrdup(host);*/
 }
 
 char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen)
@@ -271,7 +282,16 @@ char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen)
 	return sockaddr2str(sa, salen, 0);
 }
 
+char* xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa, socklen_t salen)
+{
+	return sockaddr2str(sa, salen, NI_NAMEREQD | IGNORE_PORT);
+}
 char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen)
 {
 	return sockaddr2str(sa, salen, NI_NUMERICHOST);
 }
+
+char* xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa, socklen_t salen)
+{
+	return sockaddr2str(sa, salen, NI_NUMERICHOST | IGNORE_PORT);
+}
diff --git a/networking/nslookup.c b/networking/nslookup.c
index 5a08844..af08162 100644
--- a/networking/nslookup.c
+++ b/networking/nslookup.c
@@ -47,7 +47,7 @@
  * ns3.kernel.org  internet address = 204.152.191.36
  */
 
-static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
+/*static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
 {
 	if (buflen <= 0) return -1;
 	buf[0] = '\0';
@@ -61,9 +61,11 @@ static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
 	}
 	return -1;
 }
+*/
 
 static int print_host(const char *hostname, const char *header)
 {
+#if 0
 	char str[128];	/* IPv6 address will fit, hostnames hopefully too */
 	struct addrinfo *result = NULL;
 	int rc;
@@ -76,6 +78,7 @@ static int print_host(const char *hostname, const char *header)
 	hint.ai_socktype = SOCK_STREAM;
 	// hint.ai_flags = AI_CANONNAME;
 	rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result);
+
 	if (!rc) {
 		struct addrinfo *cur = result;
 		// printf("%s\n", cur->ai_canonname); ?
@@ -93,6 +96,75 @@ static int print_host(const char *hostname, const char *header)
 	}
 	freeaddrinfo(result);
 	return (rc != 0);
+
+#else
+	/* We can't use host2sockaddr() - we want to get ALL addresses,
+	 * not just one */
+
+	struct addrinfo *result = NULL;
+	int rc;
+	struct addrinfo hint;
+
+	memset(&hint, 0 , sizeof(hint));
+	/* hint.ai_family = AF_UNSPEC; - zero anyway */
+	/* Needed. Or else we will get each address thrice (or more)
+	 * for each possible socket type (tcp,udp,raw...): */
+	hint.ai_socktype = SOCK_STREAM;
+	// hint.ai_flags = AI_CANONNAME;
+	rc = getaddrinfo(hostname, NULL /*service*/, &hint, &result);
+
+	if (!rc) {
+		struct addrinfo *cur = result;
+		unsigned cnt = 0;
+
+		printf("%-10s %s\n", header, hostname);
+		// printf("%s\n", cur->ai_canonname); ?
+		while (cur) {
+			char *dotted, *revhost;
+			dotted = xmalloc_sockaddr2dotted_noport(cur->ai_addr, cur->ai_addrlen);
+			revhost = xmalloc_sockaddr2hostonly_noport(cur->ai_addr, cur->ai_addrlen);
+
+			printf("Address %u: %s%c", ++cnt, dotted, revhost ? ' ' : '\n');
+			if (revhost) {
+				puts(revhost);
+				if (ENABLE_FEATURE_CLEAN_UP)
+					free(revhost);
+			}
+			if (ENABLE_FEATURE_CLEAN_UP)
+				free(dotted);
+			cur = cur->ai_next;
+		}
+	} else {
+#if ENABLE_VERBOSE_RESOLUTION_ERRORS
+		bb_error_msg("getaddrinfo('%s') failed: %s", hostname, gai_strerror(rc));
+#else
+		bb_error_msg("can't resolve '%s'", hostname);
+#endif
+	}
+	if (ENABLE_FEATURE_CLEAN_UP)
+		freeaddrinfo(result);
+	return (rc != 0);
+#endif
+}
+
+
+/* lookup the default nameserver and display it */
+static void server_print(void)
+{
+	char *server;
+
+	server = xmalloc_sockaddr2dotted_noport((struct sockaddr*)&_res.nsaddr_list[0],
+			sizeof(struct sockaddr_in));
+	/* I honestly don't know what to do if DNS server has _IPv6 address_.
+	 * Probably it is listed in
+	 * _res._u._ext_.nsaddrs[MAXNS] (of type "struct sockaddr_in6*" each)
+	 * but how to find out whether resolver uses
+	 * _res.nsaddr_list[] or _res._u._ext_.nsaddrs[], or both?
+	 * Looks like classic design from hell, BIND-grade. Hard to surpass. */
+	print_host(server, "Server:");
+	if (ENABLE_FEATURE_CLEAN_UP)
+		free(server);
+	puts("");
 }
 
 
@@ -109,40 +181,27 @@ static void set_default_dns(char *server)
 }
 
 
-/* lookup the default nameserver and display it */
-static void server_print(void)
-{
-	char str[INET6_ADDRSTRLEN];
-
-	sockaddr_to_dotted((struct sockaddr*)&_res.nsaddr_list[0], str, sizeof(str));
-	print_host(str, "Server:");
-	puts("");
-}
-
-
 int nslookup_main(int argc, char **argv)
 {
-	/*
-	* initialize DNS structure _res used in printing the default
-	* name server and in the explicit name server option feature.
-	*/
-
-	res_init();
-
-	/*
-	* We allow 1 or 2 arguments.
-	* The first is the name to be looked up and the second is an
-	* optional DNS server with which to do the lookup.
-	* More than 3 arguments is an error to follow the pattern of the
-	* standard nslookup
-	*/
+	/* We allow 1 or 2 arguments.
+	 * The first is the name to be looked up and the second is an
+	 * optional DNS server with which to do the lookup.
+	 * More than 3 arguments is an error to follow the pattern of the
+	 * standard nslookup */
 
 	if (argc < 2 || *argv[1] == '-' || argc > 3)
 		bb_show_usage();
-	else if(argc == 3)
+
+	/* initialize DNS structure _res used in printing the default
+	 * name server and in the explicit name server option feature. */
+	res_init();
+	/* rfc2133 says this enables IPv6 lookups */
+	/* (but it also says "may be enabled in /etc/resolv.conf|) */
+	/*_res.options |= RES_USE_INET6;*/
+
+	if(argc == 3)
 		set_default_dns(argv[2]);
 
 	server_print();
-	return print_host(argv[1], "Name:  ");
+	return print_host(argv[1], "Name:");
 }
-