src/usr/nslookup.c

   1 /*
   2  * Copyright (C) 2012 Patrick Plenefisch <phplenefisch@wpi.edu>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA.
  18  */
  19
  20 FILE_LICENCE ( GPL2_OR_LATER );
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <ipxe/resolv.h>
  27 #include <ipxe/tcpip.h>
  28 #include <ipxe/monojob.h>
  29 #include <ipxe/settings.h>
  30 #include <usr/nslookup.h>
  31
  32 /** @file
  33  *
  34  * Standalone name resolution
  35  *
  36  */
  37
  38 /** A name resolution request */
  39 struct nslookup {
  40         /** Reference count for this object */
  41         struct refcnt refcnt;
  42
  43         /** Job control interface */
  44         struct interface job;
  45         /** Data transfer interface */
  46         struct interface resolver;
  47
  48         /** Setting name */
  49         char *setting_name;
  50 };
  51
  52 /**
  53  * Terminate name resolution
  54  *
  55  * @v nslookup          Name resolution request
  56  * @v rc                Reason for termination
  57  */
  58 static void nslookup_close ( struct nslookup *nslookup, int rc ) {
  59
  60         /* Shut down interfaces */
  61         intf_shutdown ( &nslookup->resolver, rc );
  62         intf_shutdown ( &nslookup->job, rc );
  63 }
  64
  65 /**
  66  * Handle resolved name
  67  *
  68  * @v nslookup          Name resolution request
  69  * @v sa                Completed socket address
  70  */
  71 static void nslookup_resolv_done ( struct nslookup *nslookup,
  72                                    struct sockaddr *sa ) {
  73         struct sockaddr_in *sin;
  74         struct sockaddr_in6 *sin6;
  75         const struct setting_type *default_type;
  76         struct settings *settings;
  77         struct setting setting;
  78         void *data;
  79         size_t len;
  80         int rc;
  81
  82         /* Extract address */
  83         switch ( sa->sa_family ) {
  84         case AF_INET:
  85                 sin = ( ( struct sockaddr_in * ) sa );
  86                 data = &sin->sin_addr;
  87                 len = sizeof ( sin->sin_addr );
  88                 default_type = &setting_type_ipv4;
  89                 break;
  90         case AF_INET6:
  91                 sin6 = ( ( struct sockaddr_in6 * ) sa );
  92                 data = &sin6->sin6_addr;
  93                 len = sizeof ( sin6->sin6_addr );
  94                 default_type = &setting_type_ipv6;
  95                 break;
  96         default:
  97                 rc = -ENOTSUP;
  98                 goto err;
  99         }
 100
 101         /* Parse specified setting name */
 102         if ( ( rc = parse_setting_name ( nslookup->setting_name,
 103                                          autovivify_child_settings, &settings,
 104                                          &setting ) ) != 0 )
 105                 goto err;
 106
 107         /* Apply default type if necessary */
 108         if ( ! setting.type )
 109                 setting.type = default_type;
 110
 111         /* Store in specified setting */
 112         if ( ( rc = store_setting ( settings, &setting, data, len ) ) != 0 )
 113                 goto err;
 114
 115  err:
 116         /* Terminate name resolution */
 117         nslookup_close ( nslookup, rc );
 118 }
 119
 120 /** Name resolution resolver interface operations */
 121 static struct interface_operation nslookup_resolver_operations[] = {
 122         INTF_OP ( resolv_done, struct nslookup *, nslookup_resolv_done ),
 123         INTF_OP ( intf_close, struct nslookup *, nslookup_close ),
 124 };
 125
 126 /** Name resolution resolver interface descriptor */
 127 static struct interface_descriptor nslookup_resolver_desc =
 128         INTF_DESC_PASSTHRU ( struct nslookup, resolver,
 129                              nslookup_resolver_operations, job );
 130
 131 /** Name resolution job control interface operations */
 132 static struct interface_operation nslookup_job_operations[] = {
 133         INTF_OP ( intf_close, struct nslookup *, nslookup_close ),
 134 };
 135
 136 /** Name resolution job control interface descriptor */
 137 static struct interface_descriptor nslookup_job_desc =
 138         INTF_DESC_PASSTHRU ( struct nslookup, job,
 139                              nslookup_job_operations, resolver );
 140
 141 /**
 142  * Initiate standalone name resolution
 143  *
 144  * @v job               Parent interface
 145  * @v name              Name to resolve
 146  * @v setting_name      Setting name
 147  * @ret rc              Return status code
 148  */
 149 static int resolv_setting ( struct interface *job, const char *name,
 150                             const char *setting_name ) {
 151         struct nslookup *nslookup;
 152         struct sockaddr sa;
 153         char *setting_name_copy;
 154         int rc;
 155
 156         /* Allocate and initialise structure */
 157         nslookup = zalloc ( sizeof ( *nslookup ) + strlen ( setting_name )
 158                             + 1 /* NUL */ );
 159         if ( ! nslookup )
 160                 return -ENOMEM;
 161         ref_init ( &nslookup->refcnt, NULL );
 162         intf_init ( &nslookup->job, &nslookup_job_desc, &nslookup->refcnt );
 163         intf_init ( &nslookup->resolver, &nslookup_resolver_desc,
 164                     &nslookup->refcnt );
 165         setting_name_copy = ( ( void * ) ( nslookup + 1 ) );
 166         strcpy ( setting_name_copy, setting_name );
 167         nslookup->setting_name = setting_name_copy;
 168
 169         /* Start name resolution */
 170         memset ( &sa, 0, sizeof ( sa ) );
 171         if ( ( rc = resolv ( &nslookup->resolver, name, &sa ) ) != 0 )
 172                 goto err_resolv;
 173
 174         /* Attach parent interface, mortalise self, and return */
 175         intf_plug_plug ( &nslookup->job, job );
 176         ref_put ( &nslookup->refcnt );
 177         return 0;
 178
 179  err_resolv:
 180         ref_put ( &nslookup->refcnt );
 181         return rc;
 182 }
 183
 184 /**
 185  * Perform (blocking) standalone name resolution
 186  *
 187  * @v name              Name to resolve
 188  * @v setting_name      Setting name
 189  * @ret rc              Return status code
 190  */
 191 int nslookup ( const char *name, const char *setting_name ) {
 192         int rc;
 193
 194         /* Perform name resolution */
 195         if ( ( rc = resolv_setting ( &monojob, name, setting_name ) ) == 0 )
 196                 rc = monojob_wait ( NULL, 0 );
 197         if ( rc != 0 ) {
 198                 printf ( "Could not resolve %s: %s\n", name, strerror ( rc ) );
 199                 return rc;
 200         }
 201
 202         return 0;
 203 }