[cmdline] Add standalone "nslookup" command

Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/config/config.c

@@ -247,6 +247,9 @@ REQUIRE_OBJECT ( cpuid_cmd );
 #ifdef SYNC_CMD
 REQUIRE_OBJECT ( sync_cmd );
 #endif
+#ifdef NSLOOKUP_CMD
+REQUIRE_OBJECT ( nslookup_cmd );
+#endif
 
 /*
  * Drag in miscellaneous objects

src/config/general.h

@@ -119,6 +119,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define MENU_CMD		/* Menu commands */
 #define LOGIN_CMD		/* Login command */
 #define SYNC_CMD		/* Sync command */
+//#define NSLOOKUP_CMD		/* DNS resolving command */
 //#define TIME_CMD		/* Time commands */
 //#define DIGEST_CMD		/* Image crypto digest commands */
 //#define LOTEST_CMD		/* Loopback testing commands */

src/hci/commands/nslookup_cmd.c

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2012 Patrick Plenefisch <phplenefisch@wpi.edu>.
+ *
+ * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdio.h>
+#include <getopt.h>
+#include <ipxe/command.h>
+#include <ipxe/parseopt.h>
+#include <usr/nslookup.h>
+
+/** @file
+ *
+ * nslookup command
+ *
+ */
+
+/** "nslookup" options */
+struct nslookup_options {};
+
+/** "nslookup" option list */
+static struct option_descriptor nslookup_opts[] = {};
+
+/** "nslookup" command descriptor */
+static struct command_descriptor nslookup_cmd =
+	COMMAND_DESC ( struct nslookup_options, nslookup_opts, 2, 2,
+		       "<setting> <name>" );
+
+/**
+ * The "nslookup" command
+ *
+ * @v argc		Argument count
+ * @v argv		Argument list
+ * @ret rc		Return status code
+ */
+static int nslookup_exec ( int argc, char **argv ) {
+	struct nslookup_options opts;
+	const char *name;
+	const char *setting_name;
+	int rc;
+
+	/* Parse options */
+	if ( ( rc = parse_options ( argc, argv, &nslookup_cmd, &opts ) ) != 0 )
+		return rc;
+
+	/* Parse setting name */
+	setting_name = argv[optind];
+
+	/* Parse name to be resolved */
+	name = argv[ optind + 1 ];
+
+	/* Look up name */
+	if ( ( rc = nslookup ( name, setting_name ) ) != 0 )
+		return rc;
+
+	return 0;
+}
+
+/** The "nslookup" command */
+struct command nslookup_command __command = {
+	.name = "nslookup",
+	.exec = nslookup_exec,
+};

src/include/ipxe/errfile.h

@@ -262,6 +262,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define ERRFILE_menu_cmd	      ( ERRFILE_OTHER | 0x002d0000 )
 #define ERRFILE_validator	      ( ERRFILE_OTHER | 0x002e0000 )
 #define ERRFILE_ocsp		      ( ERRFILE_OTHER | 0x002f0000 )
+#define ERRFILE_nslookup	      ( ERRFILE_OTHER | 0x00300000 )
 
 /** @} */
 

src/include/usr/nslookup.h

@@ -0,0 +1,14 @@
+#ifndef _USR_NSLOOKUP_H
+#define _USR_NSLOOKUP_H
+
+/** @file
+ *
+ * Standalone name resolution
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+extern int nslookup ( const char *name, const char *setting_name );
+
+#endif /* _USR_NSLOOKUP_H */

src/usr/nslookup.c

@@ -0,0 +1,185 @@
+/*
+ * Copyright (C) 2012 Patrick Plenefisch <phplenefisch@wpi.edu>.
+ *
+ * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <ipxe/resolv.h>
+#include <ipxe/tcpip.h>
+#include <ipxe/monojob.h>
+#include <ipxe/settings.h>
+#include <usr/nslookup.h>
+
+/** @file
+ *
+ * Standalone name resolution
+ *
+ */
+
+/** A name resolution request */
+struct nslookup {
+	/** Reference count for this object */
+	struct refcnt refcnt;
+
+	/** Job control interface */
+	struct interface job;
+	/** Data transfer interface */
+	struct interface resolver;
+
+	/** Setting name */
+	const char *setting_name;
+};
+
+/**
+ * Terminate name resolution
+ *
+ * @v nslookup		Name resolution request
+ * @v rc		Reason for termination
+ */
+static void nslookup_close ( struct nslookup *nslookup, int rc ) {
+
+	/* Shut down interfaces */
+	intf_shutdown ( &nslookup->resolver, rc );
+	intf_shutdown ( &nslookup->job, rc );
+}
+
+/**
+ * Handle resolved name
+ *
+ * @v nslookup		Name resolution request
+ * @v sa		Completed socket address
+ */
+static void nslookup_resolv_done ( struct nslookup *nslookup,
+				   struct sockaddr *sa ) {
+	struct sockaddr_in *sin;
+	struct setting_type *type;
+	void *data;
+	size_t len;
+	int rc;
+
+	/* Extract address */
+	switch ( sa->sa_family ) {
+	case AF_INET:
+		sin = ( ( struct sockaddr_in * ) sa );
+		data = &sin->sin_addr;
+		len = sizeof ( sin->sin_addr );
+		type = &setting_type_ipv4;
+		break;
+	default:
+		rc = -ENOTSUP;
+		goto err;
+	}
+
+	/* Save in specified setting */
+	if ( ( rc = store_named_setting ( nslookup->setting_name, type,
+					  data, len ) ) != 0 )
+		goto err;
+
+ err:
+	/* Terminate name resolution */
+	nslookup_close ( nslookup, rc );
+}
+
+/** Name resolution resolver interface operations */
+static struct interface_operation nslookup_resolver_operations[] = {
+	INTF_OP ( resolv_done, struct nslookup *, nslookup_resolv_done ),
+	INTF_OP ( intf_close, struct nslookup *, nslookup_close ),
+};
+
+/** Name resolution resolver interface descriptor */
+static struct interface_descriptor nslookup_resolver_desc =
+	INTF_DESC_PASSTHRU ( struct nslookup, resolver,
+			     nslookup_resolver_operations, job );
+
+/** Name resolution job control interface operations */
+static struct interface_operation nslookup_job_operations[] = {
+	INTF_OP ( intf_close, struct nslookup *, nslookup_close ),
+};
+
+/** Name resolution job control interface descriptor */
+static struct interface_descriptor nslookup_job_desc =
+	INTF_DESC_PASSTHRU ( struct nslookup, job,
+			     nslookup_job_operations, resolver );
+
+/**
+ * Initiate standalone name resolution
+ *
+ * @v job		Parent interface
+ * @v name		Name to resolve
+ * @v setting_name	Setting name
+ * @ret rc		Return status code
+ */
+static int resolv_setting ( struct interface *job, const char *name,
+			    const char *setting_name ) {
+	struct nslookup *nslookup;
+	struct sockaddr sa;
+	char *setting_name_copy;
+	int rc;
+
+	/* Allocate and initialise structure */
+	nslookup = zalloc ( sizeof ( *nslookup ) + strlen ( setting_name )
+			    + 1 /* NUL */ );
+	if ( ! nslookup )
+		return -ENOMEM;
+	ref_init ( &nslookup->refcnt, NULL );
+	intf_init ( &nslookup->job, &nslookup_job_desc, &nslookup->refcnt );
+	intf_init ( &nslookup->resolver, &nslookup_resolver_desc,
+		    &nslookup->refcnt );
+	setting_name_copy = ( ( void * ) ( nslookup + 1 ) );
+	strcpy ( setting_name_copy, setting_name );
+	nslookup->setting_name = setting_name_copy;
+
+	/* Start name resolution */
+	memset ( &sa, 0, sizeof ( sa ) );
+	if ( ( rc = resolv ( &nslookup->resolver, name, &sa ) ) != 0 )
+		goto err_resolv;
+
+	/* Attach parent interface, mortalise self, and return */
+	intf_plug_plug ( &nslookup->job, job );
+	ref_put ( &nslookup->refcnt );
+	return 0;
+
+ err_resolv:
+	ref_put ( &nslookup->refcnt );
+	return rc;
+}
+
+/**
+ * Perform (blocking) standalone name resolution
+ *
+ * @v name		Name to resolve
+ * @v setting_name	Setting name
+ * @ret rc		Return status code
+ */
+int nslookup ( const char *name, const char *setting_name ) {
+	int rc;
+
+	/* Perform name resolution */
+	if ( ( rc = resolv_setting ( &monojob, name, setting_name ) ) == 0 )
+		rc = monojob_wait ( NULL );
+	if ( rc != 0 ) {
+		printf ( "Could not resolve %s: %s\n", name, strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
+}