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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-01-22 22:43:05 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-01-22 22:43:05 +0000
commit448f0241e06e7df2003b7f8afcf01e7406762b4e (patch)
treebc4a002a534b4c0fb8bba09dbd46f93cea5a38c6 /networking
parentfdcd7c4237a99682724ffbf4e40ab50a40197c56 (diff)
downloadbusybox-448f0241e06e7df2003b7f8afcf01e7406762b4e.tar.gz
busybox-448f0241e06e7df2003b7f8afcf01e7406762b4e.tar.bz2
nslookup: full circle. Here we started IPv6 work. Use "new API"
and thus save a few bytes.
Diffstat (limited to 'networking')
-rw-r--r--networking/nslookup.c117
1 files changed, 88 insertions, 29 deletions
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:");
}
-