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authorAndreas Baumann <mail@andreasbaumann.cc>2015-01-03 12:04:58 +0100
committerAndreas Baumann <mail@andreasbaumann.cc>2015-01-03 12:04:58 +0100
commit008d0be72b2f160382c6e880765e96b64a050c65 (patch)
tree36f48a98a3815a408e2ce1693dd182af90f80305 /release/src/router/busybox/networking/nslookup.c
parent611becfb8726c60cb060368541ad98191d4532f5 (diff)
downloadtomato-008d0be72b2f160382c6e880765e96b64a050c65.tar.gz
tomato-008d0be72b2f160382c6e880765e96b64a050c65.tar.bz2
imported original firmware WRT54GL_v4.30.11_11_US
Diffstat (limited to 'release/src/router/busybox/networking/nslookup.c')
-rw-r--r--release/src/router/busybox/networking/nslookup.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/release/src/router/busybox/networking/nslookup.c b/release/src/router/busybox/networking/nslookup.c
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+++ b/release/src/router/busybox/networking/nslookup.c
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+/* vi: set sw=4 ts=4: */
+/*
+ * Mini nslookup implementation for busybox
+ *
+ * Copyright (C) 1999,2000 by Lineo, inc. and John Beppu
+ * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org>
+ *
+ * Correct default name server display and explicit name server option
+ * added by Ben Zeckel <bzeckel@hmc.edu> June 2001
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.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.
+ */
+
+/* only works for IPv4 */
+static int addr_fprint(char *addr)
+{
+ u_int8_t split[4];
+ u_int32_t ip;
+ u_int32_t *x = (u_int32_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
+ */
+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(", ");
+ }
+ }
+
+ }
+ printf("\n");
+ return 0;
+}
+
+/* print the results as nslookup would */
+static struct hostent *hostent_fprint(struct hostent *host, const char *server_host)
+{
+ if (host) {
+ printf("%s %s\n", server_host, host->h_name);
+ addr_list_fprint(host->h_addr_list);
+ } else {
+ printf("*** Unknown host\n");
+ }
+ return host;
+}
+
+/* changes a c-string matching the perl regex \d+\.\d+\.\d+\.\d+
+ * into a u_int32_t
+ */
+static u_int32_t str_to_addr(const char *addr)
+{
+ u_int32_t split[4];
+ u_int32_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 */
+}
+
+/* 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:");
+ printf("\n");
+}
+
+/* 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)
+{
+ struct in_addr server_in_addr;
+
+ if(inet_aton(server,&server_in_addr))
+ {
+ _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)
+{
+ while (*s) {
+ if ((isdigit(*s)) || (*s == '.')) {
+ s++;
+ continue;
+ }
+ return 0;
+ }
+ return 1;
+}
+
+/* ________________________________________________________________________ */
+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.
+ */
+
+ 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
+ */
+
+ 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: ");
+ return EXIT_SUCCESS;
+}
+
+/* $Id: nslookup.c,v 1.1.3.1 2004/12/29 07:07:46 honor Exp $ */