busybox: add musl compatible nslookup replacement
Add an alternative nslookup applet implementation which is compatible with musl libc wrt. name server selection and which supports a number of additional features such as query type selection. Signed-off-by: Jo-Philipp Wich <jo@mein.io>
This commit is contained in:
parent
ac388ad83a
commit
de5b8e5d2f
3 changed files with 931 additions and 1 deletions
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@ -2270,6 +2270,9 @@ config BUSYBOX_DEFAULT_FEATURE_NETSTAT_PRG
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bool
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default y
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config BUSYBOX_DEFAULT_NSLOOKUP
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bool
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default n
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config BUSYBOX_DEFAULT_NSLOOKUP_LEDE
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bool
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default y
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config BUSYBOX_DEFAULT_NTPD
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@ -704,6 +704,19 @@ config BUSYBOX_CONFIG_NSLOOKUP
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default BUSYBOX_DEFAULT_NSLOOKUP
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help
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nslookup is a tool to query Internet name servers.
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config BUSYBOX_CONFIG_NSLOOKUP_LEDE
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bool "nslookup_lede"
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depends on !BUSYBOX_CONFIG_NSLOOKUP
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default BUSYBOX_DEFAULT_NSLOOKUP_LEDE
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help
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nslookup is a tool to query Internet name servers (LEDE flavor).
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config BUSYBOX_CONFIG_FEATURE_NSLOOKUP_LEDE_LONG_OPTIONS
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bool "Enable long options"
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default BUSYBOX_DEFAULT_FEATURE_NSLOOKUP_LEDE_LONG_OPTIONS
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depends on BUSYBOX_CONFIG_NSLOOKUP_LEDE && BUSYBOX_CONFIG_LONG_OPTS
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help
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Support long options for the nslookup applet.
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config BUSYBOX_CONFIG_NTPD
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bool "ntpd"
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default BUSYBOX_DEFAULT_NTPD
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@ -1091,7 +1104,7 @@ source udhcp/Config.in
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config BUSYBOX_CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS
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string "ifup udhcpc command line options"
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default BUSYBOX_DEFAULT_IFUPDOWN_UDHCPC_CMD_OPTIONS
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depends on BUSYBOX_CONFIG_IFUPDOWN && BUSYBOX_CONFIG_UDHCPC
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depends on BUSYBOX_CONFIG_IFUP || BUSYBOX_CONFIG_IFDOWN
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help
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Command line options to pass to udhcpc from ifup.
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Intended to alter options not available in /etc/network/interfaces.
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914
package/utils/busybox/patches/230-add_nslookup_lede.patch
Normal file
914
package/utils/busybox/patches/230-add_nslookup_lede.patch
Normal file
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@ -0,0 +1,914 @@
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From 8c1440a0934dd8b3ad6aae48d6653b5ba6fce8a1 Mon Sep 17 00:00:00 2001
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From: Jo-Philipp Wich <jo@mein.io>
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Date: Tue, 14 Mar 2017 22:21:34 +0100
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Subject: [PATCH] networking: add LEDE nslookup applet
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Add a new LEDE nslookup applet which is compatible with musl libc
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and providing more features like ability to specify query type.
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In contrast to busybox' builtin nslookup applet, this variant does
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not rely on libc resolver internals but uses explicit send logic
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and the libresolv primitives to parse received DNS responses.
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Signed-off-by: Jo-Philipp Wich <jo@mein.io>
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---
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Makefile.flags | 6 +
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networking/nslookup_lede.c | 869 +++++++++++++++++++++++++++++++++++++++++++++
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2 files changed, 875 insertions(+)
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create mode 100644 networking/nslookup_lede.c
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diff --git a/Makefile.flags b/Makefile.flags
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index 65021de..096ab77 100644
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--- a/Makefile.flags
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+++ b/Makefile.flags
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@@ -134,6 +134,12 @@ else
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LDLIBS += m
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endif
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+# nslookup_lede might need the resolv library
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+RESOLV_AVAILABLE := $(shell echo 'int main(void){res_init();return 0;}' >resolvtest.c; $(CC) $(CFLAGS) -include resolv.h -lresolv -o /dev/null resolvtest.c >/dev/null 2>&1 && echo "y"; rm resolvtest.c)
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+ifeq ($(RESOLV_AVAILABLE),y)
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+LDLIBS += resolv
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+endif
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+
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# libpam may use libpthread, libdl and/or libaudit.
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# On some platforms that requires an explicit -lpthread, -ldl, -laudit.
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# However, on *other platforms* it fails when some of those flags
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diff --git a/networking/nslookup_lede.c b/networking/nslookup_lede.c
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new file mode 100644
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index 0000000..fe927ad
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--- /dev/null
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+++ b/networking/nslookup_lede.c
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@@ -0,0 +1,869 @@
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+/*
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+ * nslookup_lede - musl compatible replacement for busybox nslookup
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+ *
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+ * Copyright (C) 2017 Jo-Philipp Wich <jo@mein.io>
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+ *
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+ * Permission to use, copy, modify, and/or distribute this software for any
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+ * purpose with or without fee is hereby granted, provided that the above
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+ * copyright notice and this permission notice appear in all copies.
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+ *
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+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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+ */
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+
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+//config:config NSLOOKUP_LEDE
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+//config: bool "nslookup_lede"
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+//config: depends on !NSLOOKUP
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+//config: default y
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+//config: help
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+//config: nslookup is a tool to query Internet name servers (LEDE flavor).
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+//config:
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+//config:config FEATURE_NSLOOKUP_LEDE_LONG_OPTIONS
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+//config: bool "Enable long options"
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+//config: default y
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+//config: depends on NSLOOKUP_LEDE && LONG_OPTS
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+//config: help
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+//config: Support long options for the nslookup applet.
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+
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+//applet:IF_NSLOOKUP_LEDE(APPLET(nslookup, BB_DIR_USR_BIN, BB_SUID_DROP))
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+
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+//kbuild:lib-$(CONFIG_NSLOOKUP_LEDE) += nslookup_lede.o
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+
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+//usage:#define nslookup_lede_trivial_usage
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+//usage: "[HOST] [SERVER]"
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+//usage:#define nslookup_lede_full_usage "\n\n"
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+//usage: "Query the nameserver for the IP address of the given HOST\n"
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+//usage: "optionally using a specified DNS server"
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+//usage:
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+//usage:#define nslookup_lede_example_usage
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+//usage: "$ nslookup localhost\n"
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+//usage: "Server: default\n"
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+//usage: "Address: default\n"
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+//usage: "\n"
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+//usage: "Name: debian\n"
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+//usage: "Address: 127.0.0.1\n"
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+
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+#include <stdio.h>
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+#include <resolv.h>
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+#include <string.h>
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+#include <errno.h>
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+#include <time.h>
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+#include <poll.h>
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+#include <unistd.h>
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+#include <stdlib.h>
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+#include <sys/socket.h>
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+#include <arpa/inet.h>
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+#include <net/if.h>
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+#include <netdb.h>
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+
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+#include "libbb.h"
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+
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+struct ns {
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+ const char *name;
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+ len_and_sockaddr addr;
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+ int failures;
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+ int replies;
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+};
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+
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+struct query {
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+ const char *name;
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+ size_t qlen, rlen;
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+ unsigned char query[512], reply[512];
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+ unsigned long latency;
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+ int rcode, n_ns;
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+};
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+
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+static struct {
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+ int type;
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+ const char *name;
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+} qtypes[] = {
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+ { ns_t_soa, "SOA" },
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+ { ns_t_ns, "NS" },
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+ { ns_t_a, "A" },
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+ { ns_t_aaaa, "AAAA" },
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+ { ns_t_cname, "CNAME" },
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+ { ns_t_mx, "MX" },
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+ { ns_t_txt, "TXT" },
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+ { ns_t_ptr, "PTR" },
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+ { ns_t_any, "ANY" },
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+ { }
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+};
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+
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+static const char *rcodes[] = {
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+ "NOERROR",
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+ "FORMERR",
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+ "SERVFAIL",
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+ "NXDOMAIN",
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+ "NOTIMP",
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+ "REFUSED",
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+ "YXDOMAIN",
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+ "YXRRSET",
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+ "NXRRSET",
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+ "NOTAUTH",
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+ "NOTZONE",
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+ "RESERVED11",
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+ "RESERVED12",
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+ "RESERVED13",
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+ "RESERVED14",
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+ "RESERVED15",
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+ "BADVERS"
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+};
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+
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+static unsigned int default_port = 53;
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+static unsigned int default_retry = 2;
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+static unsigned int default_timeout = 5;
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+
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+
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+static int parse_reply(const unsigned char *msg, size_t len)
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+{
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+ ns_msg handle;
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+ ns_rr rr;
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+ int i, n, rdlen;
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+ const char *format = NULL;
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+ char astr[INET6_ADDRSTRLEN], dname[MAXDNAME];
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+ const unsigned char *cp;
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+
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+ if (ns_initparse(msg, len, &handle) != 0) {
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+ //fprintf(stderr, "Unable to parse reply: %s\n", strerror(errno));
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+ return -1;
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+ }
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+
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+ for (i = 0; i < ns_msg_count(handle, ns_s_an); i++) {
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+ if (ns_parserr(&handle, ns_s_an, i, &rr) != 0) {
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+ //fprintf(stderr, "Unable to parse resource record: %s\n", strerror(errno));
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+ return -1;
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+ }
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+
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+ rdlen = ns_rr_rdlen(rr);
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+
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+ switch (ns_rr_type(rr))
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+ {
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+ case ns_t_a:
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+ if (rdlen != 4) {
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+ //fprintf(stderr, "Unexpected A record length\n");
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+ return -1;
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+ }
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+ inet_ntop(AF_INET, ns_rr_rdata(rr), astr, sizeof(astr));
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+ printf("Name:\t%s\nAddress: %s\n", ns_rr_name(rr), astr);
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+ break;
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+
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+ case ns_t_aaaa:
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+ if (rdlen != 16) {
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+ //fprintf(stderr, "Unexpected AAAA record length\n");
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+ return -1;
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+ }
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+ inet_ntop(AF_INET6, ns_rr_rdata(rr), astr, sizeof(astr));
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+ printf("%s\thas AAAA address %s\n", ns_rr_name(rr), astr);
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+ break;
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+
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+ case ns_t_ns:
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+ if (!format)
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+ format = "%s\tnameserver = %s\n";
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+ /* fall through */
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+
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+ case ns_t_cname:
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+ if (!format)
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+ format = "%s\tcanonical name = %s\n";
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+ /* fall through */
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+
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+ case ns_t_ptr:
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+ if (!format)
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+ format = "%s\tname = %s\n";
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+ if (ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
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+ ns_rr_rdata(rr), dname, sizeof(dname)) < 0) {
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+ //fprintf(stderr, "Unable to uncompress domain: %s\n", strerror(errno));
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+ return -1;
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+ }
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+ printf(format, ns_rr_name(rr), dname);
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+ break;
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+
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+ case ns_t_mx:
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+ if (rdlen < 2) {
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+ fprintf(stderr, "MX record too short\n");
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+ return -1;
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+ }
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+ n = ns_get16(ns_rr_rdata(rr));
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+ if (ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
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+ ns_rr_rdata(rr) + 2, dname, sizeof(dname)) < 0) {
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+ //fprintf(stderr, "Cannot uncompress MX domain: %s\n", strerror(errno));
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+ return -1;
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+ }
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+ printf("%s\tmail exchanger = %d %s\n", ns_rr_name(rr), n, dname);
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+ break;
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+
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+ case ns_t_txt:
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+ if (rdlen < 1) {
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+ //fprintf(stderr, "TXT record too short\n");
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+ return -1;
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+ }
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+ n = *(unsigned char *)ns_rr_rdata(rr);
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+ if (n > 0) {
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+ memset(dname, 0, sizeof(dname));
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+ memcpy(dname, ns_rr_rdata(rr) + 1, n);
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+ printf("%s\ttext = \"%s\"\n", ns_rr_name(rr), dname);
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+ }
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+ break;
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+
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+ case ns_t_soa:
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+ if (rdlen < 20) {
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+ //fprintf(stderr, "SOA record too short\n");
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+ return -1;
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+ }
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+
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+ printf("%s\n", ns_rr_name(rr));
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+
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+ cp = ns_rr_rdata(rr);
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+ n = ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
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+ cp, dname, sizeof(dname));
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+
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+ if (n < 0) {
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+ //fprintf(stderr, "Unable to uncompress domain: %s\n", strerror(errno));
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+ return -1;
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+ }
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+
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+ printf("\torigin = %s\n", dname);
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+ cp += n;
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+
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+ n = ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
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+ cp, dname, sizeof(dname));
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+
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+ if (n < 0) {
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+ //fprintf(stderr, "Unable to uncompress domain: %s\n", strerror(errno));
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+ return -1;
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+ }
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+
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+ printf("\tmail addr = %s\n", dname);
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+ cp += n;
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+
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+ printf("\tserial = %lu\n", ns_get32(cp));
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+ cp += 4;
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+
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+ printf("\trefresh = %lu\n", ns_get32(cp));
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+ cp += 4;
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+
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+ printf("\tretry = %lu\n", ns_get32(cp));
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+ cp += 4;
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+
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+ printf("\texpire = %lu\n", ns_get32(cp));
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+ cp += 4;
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+
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+ printf("\tminimum = %lu\n", ns_get32(cp));
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+ break;
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+
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+ default:
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+ break;
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+ }
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+ }
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+
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+ return i;
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+}
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+
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+static int parse_nsaddr(const char *addrstr, len_and_sockaddr *lsa)
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+{
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+ char *eptr, *hash, ifname[IFNAMSIZ];
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+ unsigned int port = default_port;
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+ unsigned int scope = 0;
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+
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+ hash = strchr(addrstr, '#');
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+
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+ if (hash) {
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+ *hash++ = '\0';
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+ port = strtoul(hash, &eptr, 10);
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+
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+ if (eptr == hash || *eptr != '\0' || port > 65535) {
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+ errno = EINVAL;
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+ return -1;
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+ }
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+ }
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+
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+ hash = strchr(addrstr, '%');
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+
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+ if (hash) {
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+ for (eptr = ++hash; *eptr != '\0' && *eptr != '#'; eptr++) {
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+ if ((eptr - hash) >= IFNAMSIZ) {
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+ errno = ENODEV;
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+ return -1;
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+ }
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+
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+ ifname[eptr - hash] = *eptr;
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+ }
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+
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+ ifname[eptr - hash] = '\0';
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+ scope = if_nametoindex(ifname);
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+
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+ if (scope == 0) {
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+ errno = ENODEV;
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+ return -1;
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+ }
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+ }
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+
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+ if (inet_pton(AF_INET6, addrstr, &lsa->u.sin6.sin6_addr)) {
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+ lsa->u.sin6.sin6_family = AF_INET6;
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+ lsa->u.sin6.sin6_port = htons(port);
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+ lsa->u.sin6.sin6_scope_id = scope;
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+ lsa->len = sizeof(lsa->u.sin6);
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+ return 0;
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+ }
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+
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+ if (!scope && inet_pton(AF_INET, addrstr, &lsa->u.sin.sin_addr)) {
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+ lsa->u.sin.sin_family = AF_INET;
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+ lsa->u.sin.sin_port = htons(port);
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+ lsa->len = sizeof(lsa->u.sin);
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+ return 0;
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+ }
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+
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+ errno = EINVAL;
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+ return -1;
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+}
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+
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+static char *make_ptr(const char *addrstr)
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+{
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+ const char *hexdigit = "0123456789abcdef";
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+ static char ptrstr[73];
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+ unsigned char addr[16];
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+ char *ptr = ptrstr;
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+ int i;
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+
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+ if (inet_pton(AF_INET6, addrstr, addr)) {
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+ if (memcmp(addr, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12) != 0) {
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+ for (i = 0; i < 16; i++) {
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+ *ptr++ = hexdigit[(unsigned char)addr[15 - i] & 0xf];
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+ *ptr++ = '.';
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+ *ptr++ = hexdigit[(unsigned char)addr[15 - i] >> 4];
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+ *ptr++ = '.';
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+ }
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+ strcpy(ptr, "ip6.arpa");
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+ }
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+ else {
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+ sprintf(ptr, "%u.%u.%u.%u.in-addr.arpa",
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+ addr[15], addr[14], addr[13], addr[12]);
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+ }
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+
|
||||
+ return ptrstr;
|
||||
+ }
|
||||
+
|
||||
+ if (inet_pton(AF_INET, addrstr, addr)) {
|
||||
+ sprintf(ptr, "%u.%u.%u.%u.in-addr.arpa",
|
||||
+ addr[3], addr[2], addr[1], addr[0]);
|
||||
+ return ptrstr;
|
||||
+ }
|
||||
+
|
||||
+ return NULL;
|
||||
+}
|
||||
+
|
||||
+static unsigned long mtime(void)
|
||||
+{
|
||||
+ struct timespec ts;
|
||||
+ clock_gettime(CLOCK_REALTIME, &ts);
|
||||
+ return (unsigned long)ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
|
||||
+}
|
||||
+
|
||||
+static void to_v4_mapped(len_and_sockaddr *a)
|
||||
+{
|
||||
+ if (a->u.sa.sa_family != AF_INET)
|
||||
+ return;
|
||||
+
|
||||
+ memcpy(a->u.sin6.sin6_addr.s6_addr + 12,
|
||||
+ &a->u.sin.sin_addr, 4);
|
||||
+
|
||||
+ memcpy(a->u.sin6.sin6_addr.s6_addr,
|
||||
+ "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
|
||||
+
|
||||
+ a->u.sin6.sin6_family = AF_INET6;
|
||||
+ a->u.sin6.sin6_flowinfo = 0;
|
||||
+ a->u.sin6.sin6_scope_id = 0;
|
||||
+ a->len = sizeof(a->u.sin6);
|
||||
+}
|
||||
+
|
||||
+
|
||||
+/*
|
||||
+ * Function logic borrowed & modified from musl libc, res_msend.c
|
||||
+ */
|
||||
+
|
||||
+static int send_queries(struct ns *ns, int n_ns, struct query *queries, int n_queries)
|
||||
+{
|
||||
+ int fd;
|
||||
+ int timeout = default_timeout * 1000, retry_interval, servfail_retry = 0;
|
||||
+ len_and_sockaddr from = { };
|
||||
+ int one = 1;
|
||||
+ int recvlen = 0;
|
||||
+ int n_replies = 0;
|
||||
+ struct pollfd pfd;
|
||||
+ unsigned long t0, t1, t2;
|
||||
+ int nn, qn, next_query = 0;
|
||||
+
|
||||
+ from.u.sa.sa_family = AF_INET;
|
||||
+ from.len = sizeof(from.u.sin);
|
||||
+
|
||||
+ for (nn = 0; nn < n_ns; nn++) {
|
||||
+ if (ns[nn].addr.u.sa.sa_family == AF_INET6) {
|
||||
+ from.u.sa.sa_family = AF_INET6;
|
||||
+ from.len = sizeof(from.u.sin6);
|
||||
+ break;
|
||||
+ }
|
||||
+ }
|
||||
+
|
||||
+ /* Get local address and open/bind a socket */
|
||||
+ fd = socket(from.u.sa.sa_family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
|
||||
+
|
||||
+ /* Handle case where system lacks IPv6 support */
|
||||
+ if (fd < 0 && from.u.sa.sa_family == AF_INET6 && errno == EAFNOSUPPORT) {
|
||||
+ fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
|
||||
+ from.u.sa.sa_family = AF_INET;
|
||||
+ }
|
||||
+
|
||||
+ if (fd < 0)
|
||||
+ return -1;
|
||||
+
|
||||
+ if (bind(fd, &from.u.sa, from.len) < 0) {
|
||||
+ close(fd);
|
||||
+ return -1;
|
||||
+ }
|
||||
+
|
||||
+ /* Convert any IPv4 addresses in a mixed environment to v4-mapped */
|
||||
+ if (from.u.sa.sa_family == AF_INET6) {
|
||||
+ setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
|
||||
+
|
||||
+ for (nn = 0; nn < n_ns; nn++)
|
||||
+ to_v4_mapped(&ns[nn].addr);
|
||||
+ }
|
||||
+
|
||||
+ pfd.fd = fd;
|
||||
+ pfd.events = POLLIN;
|
||||
+ retry_interval = timeout / default_retry;
|
||||
+ t0 = t2 = mtime();
|
||||
+ t1 = t2 - retry_interval;
|
||||
+
|
||||
+ for (; t2 - t0 < timeout; t2 = mtime()) {
|
||||
+ if (t2 - t1 >= retry_interval) {
|
||||
+ for (qn = 0; qn < n_queries; qn++) {
|
||||
+ if (queries[qn].rlen)
|
||||
+ continue;
|
||||
+
|
||||
+ for (nn = 0; nn < n_ns; nn++) {
|
||||
+ sendto(fd, queries[qn].query, queries[qn].qlen,
|
||||
+ MSG_NOSIGNAL, &ns[nn].addr.u.sa, ns[nn].addr.len);
|
||||
+ }
|
||||
+ }
|
||||
+
|
||||
+ t1 = t2;
|
||||
+ servfail_retry = 2 * n_queries;
|
||||
+ }
|
||||
+
|
||||
+ /* Wait for a response, or until time to retry */
|
||||
+ if (poll(&pfd, 1, t1+retry_interval-t2) <= 0)
|
||||
+ continue;
|
||||
+
|
||||
+ while (1) {
|
||||
+ recvlen = recvfrom(fd, queries[next_query].reply,
|
||||
+ sizeof(queries[next_query].reply), 0,
|
||||
+ &from.u.sa, &from.len);
|
||||
+
|
||||
+ /* read error */
|
||||
+ if (recvlen < 0)
|
||||
+ break;
|
||||
+
|
||||
+ /* Ignore non-identifiable packets */
|
||||
+ if (recvlen < 4)
|
||||
+ continue;
|
||||
+
|
||||
+ /* Ignore replies from addresses we didn't send to */
|
||||
+ for (nn = 0; nn < n_ns; nn++)
|
||||
+ if (memcmp(&from.u.sa, &ns[nn].addr.u.sa, from.len) == 0)
|
||||
+ break;
|
||||
+
|
||||
+ if (nn >= n_ns)
|
||||
+ continue;
|
||||
+
|
||||
+ /* Find which query this answer goes with, if any */
|
||||
+ for (qn = next_query; qn < n_queries; qn++)
|
||||
+ if (!memcmp(queries[next_query].reply, queries[qn].query, 2))
|
||||
+ break;
|
||||
+
|
||||
+ if (qn >= n_queries || queries[qn].rlen)
|
||||
+ continue;
|
||||
+
|
||||
+ queries[qn].rcode = queries[next_query].reply[3] & 15;
|
||||
+ queries[qn].latency = mtime() - t0;
|
||||
+ queries[qn].n_ns = nn;
|
||||
+
|
||||
+ ns[nn].replies++;
|
||||
+
|
||||
+ /* Only accept positive or negative responses;
|
||||
+ * retry immediately on server failure, and ignore
|
||||
+ * all other codes such as refusal. */
|
||||
+ switch (queries[qn].rcode) {
|
||||
+ case 0:
|
||||
+ case 3:
|
||||
+ break;
|
||||
+
|
||||
+ case 2:
|
||||
+ if (servfail_retry && servfail_retry--) {
|
||||
+ ns[nn].failures++;
|
||||
+ sendto(fd, queries[qn].query, queries[qn].qlen,
|
||||
+ MSG_NOSIGNAL, &ns[nn].addr.u.sa, ns[nn].addr.len);
|
||||
+ }
|
||||
+ /* fall through */
|
||||
+
|
||||
+ default:
|
||||
+ continue;
|
||||
+ }
|
||||
+
|
||||
+ /* Store answer */
|
||||
+ n_replies++;
|
||||
+
|
||||
+ queries[qn].rlen = recvlen;
|
||||
+
|
||||
+ if (qn == next_query) {
|
||||
+ while (next_query < n_queries) {
|
||||
+ if (!queries[next_query].rlen)
|
||||
+ break;
|
||||
+
|
||||
+ next_query++;
|
||||
+ }
|
||||
+ }
|
||||
+ else {
|
||||
+ memcpy(queries[qn].reply, queries[next_query].reply, recvlen);
|
||||
+ }
|
||||
+
|
||||
+ if (next_query >= n_queries)
|
||||
+ return n_replies;
|
||||
+ }
|
||||
+ }
|
||||
+
|
||||
+ return n_replies;
|
||||
+}
|
||||
+
|
||||
+static struct ns *add_ns(struct ns **ns, int *n_ns, const char *addr)
|
||||
+{
|
||||
+ char portstr[sizeof("65535")], *p;
|
||||
+ len_and_sockaddr a = { };
|
||||
+ struct ns *tmp;
|
||||
+ struct addrinfo *ai, *aip, hints = {
|
||||
+ .ai_flags = AI_NUMERICSERV,
|
||||
+ .ai_socktype = SOCK_DGRAM
|
||||
+ };
|
||||
+
|
||||
+ if (parse_nsaddr(addr, &a)) {
|
||||
+ /* Maybe we got a domain name, attempt to resolve it using the standard
|
||||
+ * resolver routines */
|
||||
+
|
||||
+ p = strchr(addr, '#');
|
||||
+ snprintf(portstr, sizeof(portstr), "%hu",
|
||||
+ (unsigned short)(p ? strtoul(p, NULL, 10) : default_port));
|
||||
+
|
||||
+ if (!getaddrinfo(addr, portstr, &hints, &ai)) {
|
||||
+ for (aip = ai; aip; aip = aip->ai_next) {
|
||||
+ if (aip->ai_addr->sa_family != AF_INET &&
|
||||
+ aip->ai_addr->sa_family != AF_INET6)
|
||||
+ continue;
|
||||
+
|
||||
+ tmp = realloc(*ns, sizeof(**ns) * (*n_ns + 1));
|
||||
+
|
||||
+ if (!tmp)
|
||||
+ return NULL;
|
||||
+
|
||||
+ *ns = tmp;
|
||||
+
|
||||
+ (*ns)[*n_ns].name = addr;
|
||||
+ (*ns)[*n_ns].replies = 0;
|
||||
+ (*ns)[*n_ns].failures = 0;
|
||||
+ (*ns)[*n_ns].addr.len = aip->ai_addrlen;
|
||||
+
|
||||
+ memcpy(&(*ns)[*n_ns].addr.u.sa, aip->ai_addr, aip->ai_addrlen);
|
||||
+
|
||||
+ (*n_ns)++;
|
||||
+ }
|
||||
+
|
||||
+ freeaddrinfo(ai);
|
||||
+
|
||||
+ return &(*ns)[*n_ns];
|
||||
+ }
|
||||
+
|
||||
+ return NULL;
|
||||
+ }
|
||||
+
|
||||
+ tmp = realloc(*ns, sizeof(**ns) * (*n_ns + 1));
|
||||
+
|
||||
+ if (!tmp)
|
||||
+ return NULL;
|
||||
+
|
||||
+ *ns = tmp;
|
||||
+
|
||||
+ (*ns)[*n_ns].addr = a;
|
||||
+ (*ns)[*n_ns].name = addr;
|
||||
+ (*ns)[*n_ns].replies = 0;
|
||||
+ (*ns)[*n_ns].failures = 0;
|
||||
+
|
||||
+ return &(*ns)[(*n_ns)++];
|
||||
+}
|
||||
+
|
||||
+static int parse_resolvconf(struct ns **ns, int *n_ns)
|
||||
+{
|
||||
+ int prev_n_ns = *n_ns;
|
||||
+ char line[128], *p;
|
||||
+ FILE *resolv;
|
||||
+
|
||||
+ if ((resolv = fopen("/etc/resolv.conf", "r")) != NULL) {
|
||||
+ while (fgets(line, sizeof(line), resolv)) {
|
||||
+ p = strtok(line, " \t\n");
|
||||
+
|
||||
+ if (!p || strcmp(p, "nameserver"))
|
||||
+ continue;
|
||||
+
|
||||
+ p = strtok(NULL, " \t\n");
|
||||
+
|
||||
+ if (!p)
|
||||
+ continue;
|
||||
+
|
||||
+ if (!add_ns(ns, n_ns, strdup(p))) {
|
||||
+ free(p);
|
||||
+ break;
|
||||
+ }
|
||||
+ }
|
||||
+
|
||||
+ fclose(resolv);
|
||||
+ }
|
||||
+
|
||||
+ return *n_ns - prev_n_ns;
|
||||
+}
|
||||
+
|
||||
+static struct query *add_query(struct query **queries, int *n_queries,
|
||||
+ int type, const char *dname)
|
||||
+{
|
||||
+ struct query *tmp;
|
||||
+ ssize_t qlen;
|
||||
+
|
||||
+ tmp = realloc(*queries, sizeof(**queries) * (*n_queries + 1));
|
||||
+
|
||||
+ if (!tmp)
|
||||
+ return NULL;
|
||||
+
|
||||
+ memset(&tmp[*n_queries], 0, sizeof(*tmp));
|
||||
+
|
||||
+ qlen = res_mkquery(QUERY, dname, C_IN, type, NULL, 0, NULL,
|
||||
+ tmp[*n_queries].query, sizeof(tmp[*n_queries].query));
|
||||
+
|
||||
+ tmp[*n_queries].qlen = qlen;
|
||||
+ tmp[*n_queries].name = dname;
|
||||
+ *queries = tmp;
|
||||
+
|
||||
+ return &tmp[(*n_queries)++];
|
||||
+}
|
||||
+
|
||||
+static char *sal2str(len_and_sockaddr *a)
|
||||
+{
|
||||
+ static char buf[INET6_ADDRSTRLEN + 1 + IFNAMSIZ + 1 + 5 + 1];
|
||||
+ char *p = buf;
|
||||
+
|
||||
+ if (a->u.sa.sa_family == AF_INET6) {
|
||||
+ inet_ntop(AF_INET6, &a->u.sin6.sin6_addr, buf, sizeof(buf));
|
||||
+ p += strlen(p);
|
||||
+
|
||||
+ if (a->u.sin6.sin6_scope_id) {
|
||||
+ if (if_indextoname(a->u.sin6.sin6_scope_id, p + 1)) {
|
||||
+ *p++ = '%';
|
||||
+ p += strlen(p);
|
||||
+ }
|
||||
+ }
|
||||
+ }
|
||||
+ else {
|
||||
+ inet_ntop(AF_INET, &a->u.sin.sin_addr, buf, sizeof(buf));
|
||||
+ p += strlen(p);
|
||||
+ }
|
||||
+
|
||||
+ sprintf(p, "#%hu", ntohs(a->u.sin6.sin6_port));
|
||||
+
|
||||
+ return buf;
|
||||
+}
|
||||
+
|
||||
+
|
||||
+#if ENABLE_FEATURE_NSLOOKUP_LEDE_LONG_OPTIONS
|
||||
+static const char nslookup_longopts[] ALIGN1 =
|
||||
+ "type\0" Required_argument "q"
|
||||
+ "querytype\0" Required_argument "q"
|
||||
+ "port\0" Required_argument "p"
|
||||
+ "retry\0" Required_argument "r"
|
||||
+ "timeout\0" Required_argument "t"
|
||||
+ "stats\0" Required_argument "s"
|
||||
+ ;
|
||||
+#endif
|
||||
+
|
||||
+int nslookup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
+int nslookup_main(int argc, char **argv)
|
||||
+{
|
||||
+ int rc = 1;
|
||||
+ char *ptr, *chr;
|
||||
+ struct ns *ns = NULL;
|
||||
+ struct query *queries = NULL;
|
||||
+ llist_t *type_strings = NULL;
|
||||
+ int n_ns = 0, n_queries = 0;
|
||||
+ int c, opts, option_index = 0;
|
||||
+ int stats = 0;
|
||||
+ unsigned int types = 0;
|
||||
+ HEADER *header;
|
||||
+
|
||||
+#if ENABLE_FEATURE_NSLOOKUP_LEDE_LONG_OPTIONS
|
||||
+ applet_long_options = nslookup_longopts;
|
||||
+#endif
|
||||
+
|
||||
+ opts = getopt32(argv, "+q:*p:+r:+t:+s",
|
||||
+ &type_strings, &default_port,
|
||||
+ &default_retry, &default_timeout);
|
||||
+
|
||||
+ while (type_strings) {
|
||||
+ ptr = llist_pop(&type_strings);
|
||||
+
|
||||
+ /* skip leading text, e.g. when invoked with -querytype=AAAA */
|
||||
+ if ((chr = strchr(ptr, '=')) != NULL) {
|
||||
+ ptr = chr;
|
||||
+ *ptr++ = 0;
|
||||
+ }
|
||||
+
|
||||
+ for (c = 0; qtypes[c].name; c++)
|
||||
+ if (!strcmp(qtypes[c].name, ptr))
|
||||
+ break;
|
||||
+
|
||||
+ if (!qtypes[c].name) {
|
||||
+ fprintf(stderr, "Invalid query type \"%s\"\n", ptr);
|
||||
+ goto out;
|
||||
+ }
|
||||
+
|
||||
+ types |= (1 << c);
|
||||
+ }
|
||||
+
|
||||
+ if (default_port > 65535) {
|
||||
+ fprintf(stderr, "Invalid server port\n");
|
||||
+ goto out;
|
||||
+ }
|
||||
+
|
||||
+ if (!default_retry) {
|
||||
+ fprintf(stderr, "Invalid retry value\n");
|
||||
+ goto out;
|
||||
+ }
|
||||
+
|
||||
+ if (!default_timeout) {
|
||||
+ fprintf(stderr, "Invalid timeout value\n");
|
||||
+ goto out;
|
||||
+ }
|
||||
+
|
||||
+ stats = (opts & 16);
|
||||
+
|
||||
+ if (optind >= argc)
|
||||
+ bb_show_usage();
|
||||
+
|
||||
+ for (option_index = optind;
|
||||
+ option_index < ((argc - optind) > 1 ? argc - 1 : argc);
|
||||
+ option_index++) {
|
||||
+
|
||||
+ /* No explicit type given, guess query type.
|
||||
+ * If we can convert the domain argument into a ptr (means that
|
||||
+ * inet_pton() could read it) we assume a PTR request, else
|
||||
+ * we issue A queries. */
|
||||
+ if (types == 0) {
|
||||
+ ptr = make_ptr(argv[option_index]);
|
||||
+
|
||||
+ if (ptr)
|
||||
+ add_query(&queries, &n_queries, T_PTR, ptr);
|
||||
+ else
|
||||
+ add_query(&queries, &n_queries, T_A, argv[option_index]);
|
||||
+ }
|
||||
+ else {
|
||||
+ for (c = 0; qtypes[c].name; c++)
|
||||
+ if (types & (1 << c))
|
||||
+ add_query(&queries, &n_queries, qtypes[c].type,
|
||||
+ argv[option_index]);
|
||||
+ }
|
||||
+ }
|
||||
+
|
||||
+ /* Use given DNS server if present */
|
||||
+ if (option_index < argc) {
|
||||
+ if (!add_ns(&ns, &n_ns, argv[option_index])) {
|
||||
+ fprintf(stderr, "Invalid NS server address \"%s\": %s\n",
|
||||
+ argv[option_index], strerror(errno));
|
||||
+ goto out;
|
||||
+ }
|
||||
+ }
|
||||
+ else {
|
||||
+ parse_resolvconf(&ns, &n_ns);
|
||||
+ }
|
||||
+
|
||||
+ /* Fall back to localhost if we could not find NS in resolv.conf */
|
||||
+ if (n_ns == 0) {
|
||||
+ add_ns(&ns, &n_ns, "127.0.0.1");
|
||||
+ }
|
||||
+
|
||||
+ for (c = 0; c < n_ns; c++) {
|
||||
+ rc = send_queries(&ns[c], 1, queries, n_queries);
|
||||
+
|
||||
+ if (rc < 0) {
|
||||
+ fprintf(stderr, "Failed to send queries: %s\n", strerror(errno));
|
||||
+ goto out;
|
||||
+ } else if (rc > 0) {
|
||||
+ break;
|
||||
+ }
|
||||
+ }
|
||||
+
|
||||
+ if (c >= n_ns) {
|
||||
+ fprintf(stderr,
|
||||
+ ";; connection timed out; no servers could be reached\n\n");
|
||||
+
|
||||
+ return 1;
|
||||
+ }
|
||||
+
|
||||
+ printf("Server:\t\t%s\n", ns[c].name);
|
||||
+ printf("Address:\t%s\n", sal2str(&ns[c].addr));
|
||||
+
|
||||
+ if (stats) {
|
||||
+ printf("Replies:\t%d\n", ns[c].replies);
|
||||
+ printf("Failures:\t%d\n", ns[c].failures);
|
||||
+ }
|
||||
+
|
||||
+ printf("\n");
|
||||
+
|
||||
+ for (rc = 0; rc < n_queries; rc++) {
|
||||
+ if (stats) {
|
||||
+ printf("Query #%d completed in %lums:\n", rc, queries[rc].latency);
|
||||
+ }
|
||||
+
|
||||
+ if (queries[rc].rcode != 0) {
|
||||
+ printf("** server can't find %s: %s\n", queries[rc].name,
|
||||
+ rcodes[queries[rc].rcode]);
|
||||
+ continue;
|
||||
+ }
|
||||
+
|
||||
+ c = 0;
|
||||
+
|
||||
+ if (queries[rc].rlen) {
|
||||
+ header = (HEADER *)queries[rc].reply;
|
||||
+
|
||||
+ if (!header->aa)
|
||||
+ printf("Non-authoritative answer:\n");
|
||||
+
|
||||
+ c = parse_reply(queries[rc].reply, queries[rc].rlen);
|
||||
+ }
|
||||
+
|
||||
+ if (c == 0)
|
||||
+ printf("*** Can't find %s: No answer\n", queries[rc].name);
|
||||
+ else if (c < 0)
|
||||
+ printf("*** Can't find %s: Parse error\n", queries[rc].name);
|
||||
+
|
||||
+ printf("\n");
|
||||
+ }
|
||||
+
|
||||
+ rc = 0;
|
||||
+
|
||||
+out:
|
||||
+ if (n_ns)
|
||||
+ free(ns);
|
||||
+
|
||||
+ if (n_queries)
|
||||
+ free(queries);
|
||||
+
|
||||
+ return rc;
|
||||
+}
|
||||
--
|
||||
2.1.4
|
||||
|
Loading…
Reference in a new issue