* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-#include <ctype.h>
-#include <errno.h>
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-
-#include <stdint.h>
-#include <netdb.h>
-#include <sys/socket.h>
-#include <sys/types.h>
-#include <netinet/in.h>
#include <resolv.h>
-#include <arpa/inet.h>
#include "busybox.h"
/*
- | I'm only implementing non-interactive mode;
- | I totally forgot nslookup even had an interactive mode.
+ * I'm only implementing non-interactive mode;
+ * I totally forgot nslookup even had an interactive mode.
*/
-/* only works for IPv4 */
-static int addr_fprint(char *addr)
-{
- uint8_t split[4];
- uint32_t ip;
- uint32_t *x = (uint32_t *) addr;
-
- ip = ntohl(*x);
- split[0] = (ip & 0xff000000) >> 24;
- split[1] = (ip & 0x00ff0000) >> 16;
- split[2] = (ip & 0x0000ff00) >> 8;
- split[3] = (ip & 0x000000ff);
- printf("%d.%d.%d.%d", split[0], split[1], split[2], split[3]);
- return 0;
-}
-
-/* takes the NULL-terminated array h_addr_list, and
- * prints its contents appropriately
+/* Examples of 'standard' nslookup output
+ * $ nslookup yahoo.com
+ * Server: 128.193.0.10
+ * Address: 128.193.0.10#53
+ *
+ * Non-authoritative answer:
+ * Name: yahoo.com
+ * Address: 216.109.112.135
+ * Name: yahoo.com
+ * Address: 66.94.234.13
+ *
+ * $ nslookup 204.152.191.37
+ * Server: 128.193.4.20
+ * Address: 128.193.4.20#53
+ *
+ * Non-authoritative answer:
+ * 37.191.152.204.in-addr.arpa canonical name = 37.32-27.191.152.204.in-addr.arpa.
+ * 37.32-27.191.152.204.in-addr.arpa name = zeus-pub2.kernel.org.
+ *
+ * Authoritative answers can be found from:
+ * 32-27.191.152.204.in-addr.arpa nameserver = ns1.kernel.org.
+ * 32-27.191.152.204.in-addr.arpa nameserver = ns2.kernel.org.
+ * 32-27.191.152.204.in-addr.arpa nameserver = ns3.kernel.org.
+ * ns1.kernel.org internet address = 140.211.167.34
+ * ns2.kernel.org internet address = 204.152.191.4
+ * ns3.kernel.org internet address = 204.152.191.36
*/
-static int addr_list_fprint(char **h_addr_list)
-{
- int i, j;
- char *addr_string = (h_addr_list[1])
- ? "Addresses: " : "Address: ";
-
- printf("%s ", addr_string);
- for (i = 0, j = 0; h_addr_list[i]; i++, j++) {
- addr_fprint(h_addr_list[i]);
-
- /* real nslookup does this */
- if (j == 4) {
- if (h_addr_list[i + 1]) {
- printf("\n ");
- }
- j = 0;
- } else {
- if (h_addr_list[i + 1]) {
- printf(", ");
- }
- }
+static int sockaddr_to_dotted(struct sockaddr *saddr, char *buf, int buflen)
+{
+ if (buflen <= 0) return -1;
+ buf[0] = '\0';
+ if (saddr->sa_family == AF_INET) {
+ inet_ntop(AF_INET, &((struct sockaddr_in*)saddr)->sin_addr, buf, buflen);
+ return 0;
}
- puts("");
- return 0;
+ if (saddr->sa_family == AF_INET6) {
+ inet_ntop(AF_INET6, &((struct sockaddr_in6*)saddr)->sin6_addr, buf, buflen);
+ return 0;
+ }
+ return -1;
}
-/* print the results as nslookup would */
-static struct hostent *hostent_fprint(struct hostent *host, const char *server_host)
+static int print_host(const char *hostname, const char *header)
{
- if (host) {
- printf("%s %s\n", server_host, host->h_name);
- addr_list_fprint(host->h_addr_list);
+ char str[128]; /* IPv6 address will fit, hostnames hopefully too */
+ 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;
+ // printf("%s\n", cur->ai_canonname); ?
+ while (cur) {
+ sockaddr_to_dotted(cur->ai_addr, str, sizeof(str));
+ printf("%s %s\nAddress: %s", header, hostname, str);
+ if (getnameinfo(cur->ai_addr, cur->ai_addrlen, str, sizeof(str), NULL, 0, NI_NAMEREQD))
+ str[0] = '\0';
+ printf(" %s\n", str);
+ cur = cur->ai_next;
+ }
} else {
- printf("*** Unknown host\n");
+ bb_error_msg("getaddrinfo('%s') failed: %s", hostname, gai_strerror(rc));
}
- return host;
-}
-
-/* changes a c-string matching the perl regex \d+\.\d+\.\d+\.\d+
- * into a uint32_t
- */
-static uint32_t str_to_addr(const char *addr)
-{
- uint32_t split[4];
- uint32_t ip;
-
- sscanf(addr, "%d.%d.%d.%d",
- &split[0], &split[1], &split[2], &split[3]);
-
- /* assuming sscanf worked */
- ip = (split[0] << 24) |
- (split[1] << 16) | (split[2] << 8) | (split[3]);
-
- return htonl(ip);
-}
-
-/* gethostbyaddr wrapper */
-static struct hostent *gethostbyaddr_wrapper(const char *address)
-{
- struct in_addr addr;
-
- addr.s_addr = str_to_addr(address);
- return gethostbyaddr((char *) &addr, 4, AF_INET); /* IPv4 only for now */
+ freeaddrinfo(result);
+ return (rc != 0);
}
-/* lookup the default nameserver and display it */
-static inline void server_print(void)
-{
- struct sockaddr_in def = _res.nsaddr_list[0];
- char *ip = inet_ntoa(def.sin_addr);
-
- hostent_fprint(gethostbyaddr_wrapper(ip), "Server:");
- puts("");
-}
/* alter the global _res nameserver structure to use
an explicit dns server instead of what is in /etc/resolv.h */
-static inline void set_default_dns(char *server)
+static void set_default_dns(char *server)
{
struct in_addr server_in_addr;
- if(inet_aton(server,&server_in_addr))
- {
+ if (inet_pton(AF_INET, server, &server_in_addr) > 0) {
_res.nscount = 1;
_res.nsaddr_list[0].sin_addr = server_in_addr;
}
}
-/* naive function to check whether char *s is an ip address */
-static int is_ip_address(const char *s)
+
+/* lookup the default nameserver and display it */
+static void server_print(void)
{
- while (*s) {
- if ((isdigit(*s)) || (*s == '.')) {
- s++;
- continue;
- }
- return 0;
- }
- return 1;
+ 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)
{
- struct hostent *host;
-
/*
* initialize DNS structure _res used in printing the default
* name server and in the explicit name server option feature.
* standard nslookup
*/
- if (argc < 2 || *argv[1]=='-' || argc > 3)
+ if (argc < 2 || *argv[1] == '-' || argc > 3)
bb_show_usage();
else if(argc == 3)
set_default_dns(argv[2]);
server_print();
- if (is_ip_address(argv[1])) {
- host = gethostbyaddr_wrapper(argv[1]);
- } else {
- host = xgethostbyname(argv[1]);
- }
- hostent_fprint(host, "Name: ");
- if (host) {
- return EXIT_SUCCESS;
- }
- return EXIT_FAILURE;
+ return print_host(argv[1], "Name: ");
}
/* $Id: nslookup.c,v 1.33 2004/10/13 07:25:01 andersen Exp $ */
projects / oweals / busybox.git / commitdiff