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 57531e491..e41993796 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 0addda157..188837e36 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 5a08844f0..af0816215 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:");
 }
-