utils/pxelinux-options

   1 #!/usr/bin/perl
   2 #
   3 # Set PXELINUX hard-coded options
   4 #
   5
   6 use Socket;                     # For gethostbyname
   7 use Fcntl;
   8 use bytes;
   9
  10 %option_names = (
  11       6 => 'domain-name-servers',
  12      15 => 'domain-name',
  13      54 => 'next-server',
  14     209 => 'config-file',
  15     210 => 'path-prefix',
  16     211 => 'reboottime'
  17     );
  18
  19 @fmt_oneip   = ("ip-address", \&parse_oneip, \&show_ip);
  20 @fmt_multiip = ("ip-address-list", \&parse_multiip, \&show_ip);
  21 @fmt_string  = ("string", \&parse_string, \&show_string);
  22 @fmt_uint32  = ("uint32", \&parse_uint32, \&show_uint32);
  23
  24 %option_format = (
  25       6 => \@fmt_multiip,
  26      15 => \@fmt_string,
  27      54 => \@fmt_oneip,
  28      67 => \@fmt_string,
  29     209 => \@fmt_string,
  30     210 => \@fmt_string,
  31     211 => \@fmt_uint32
  32     );
  33
  34 sub parse_oneip($)
  35 {
  36     my($s) = @_;
  37     my($name,$aliases,$addrtype,$length,@addrs) = gethostbyname($s);
  38
  39     return ($addrtype == AF_INET) ? $addrs[0] : undef;
  40 }
  41
  42 sub parse_multiip($)
  43 {
  44     my($l) = @_;
  45     my $s;
  46     my @a = ();
  47     my $addr;
  48     my $d = '';
  49
  50     foreach $s (split(/,/, $l)) {
  51         my($name,$aliases,$addrtype,$length,@addrs)
  52             = gethostbyname($s);
  53         if ($addrtype == AF_INET) {
  54             foreach $addr (@addrs) {
  55                 $d .= $addr;
  56             }
  57         }
  58     }
  59
  60     return $d ne '' ? $d : undef;
  61 }
  62
  63 sub show_ip($)
  64 {
  65     my($l) = @_;
  66
  67     if (length($l) & 3) {
  68         return undef;
  69     } else {
  70         my @h = ();
  71         my $i;
  72
  73         for ($i = 0; $i < length($l); $i += 4) {
  74             push(@h, inet_ntoa(substr($l, $i, 4)));
  75         }
  76
  77         return join(',', @h);
  78     }
  79 }
  80
  81 sub parse_string($)
  82 {
  83     return $_[0];
  84 }
  85
  86 sub show_string($)
  87 {
  88     my($s) = @_;
  89     my $o, $i, $c;
  90
  91     $o = "\'";
  92     for ($i = 0; $i < length($s); $i++) {
  93         $c = substr($s, $i, 1);
  94         if ($c eq "\'" || $c eq '!') {
  95             $o .= "\'\\$c\'";
  96         } else {
  97             $o .= $c;
  98         }
  99     }
 100     $o .= "\'";
 101
 102     return $o;
 103 }
 104
 105 sub parse_uint32($)
 106 {
 107     my($s) = @_;
 108
 109     if ($s =~ /^[0-9]+$/) {
 110         return pack("N", $s);
 111     } else {
 112         return undef;
 113     }
 114 }
 115
 116 sub show_uint32($)
 117 {
 118     my($l) = @_;
 119
 120     if (length($l) == 4) {
 121         return unpack("N", $l);
 122     } else {
 123         return undef;
 124     }
 125 }
 126
 127 sub parse_generic($)
 128 {
 129     my($s) = @_;
 130
 131     if ($s =~ /^[0-9a-f]{1,2}(:[0-9a-f]{1,2})*$/) {
 132         my $h;
 133         my @b = ();
 134
 135         foreach $h (split(/\:/, $s)) {
 136             push(@b, hex $h);
 137         }
 138
 139         return pack("C", @b);
 140     } else {
 141         return undef;
 142     }
 143 }
 144
 145 sub show_generic($)
 146 {
 147     my($l) = @_;
 148     my $i;
 149     my @h;
 150
 151     for ($i = 0; $i < length($l); $i++) {
 152         push(@h, sprintf("%02x", unpack("C", substr($l, $i, $1))));
 153     }
 154
 155     return join(':', @h);
 156 }
 157
 158 sub parse_option($$)
 159 {
 160     my($opt, $arg) = @_;
 161     my $v;
 162
 163     if (defined($option_format{$opt})) {
 164         $v = $option_format{$opt}[1]($arg);
 165         return $v if (defined($v));
 166     }
 167
 168     return parse_generic($arg);
 169 }
 170
 171 sub show_option($$)
 172 {
 173     my($opt, $arg) = @_;
 174     my $v;
 175
 176     if (defined($option_format{$opt})) {
 177         $v = $option_format{$opt}[2]($arg);
 178         return $v if (defined($v));
 179     }
 180
 181     return show_generic($arg);
 182 }
 183
 184 sub option_number($)
 185 {
 186     my($n) = @_;
 187
 188     if (defined($option_rnames{$n})) {
 189         return $option_rnames{$n};
 190     } elsif ($n =~ /^[0-9]+$/ && $n >= 1 && $n <= 254) {
 191         return $n+0;
 192     } else {
 193         return undef;
 194     }
 195 }
 196
 197 sub read_optsets($)
 198 {
 199     my($file) = @_;
 200     my $data, $bdata, $adata;
 201     my $patch_start = (stat($file))[7];
 202     my $hdroffset = 0;          # 0 means non-deep-embedded
 203     my $bufsize = 0;
 204     my $junk;
 205     my %hdr;
 206
 207     return undef unless (seek($file, 0, SEEK_SET));
 208     return undef unless (read($file, $data, 48) == 48);
 209
 210     my($mzmagic, $junk, $magic, $len, $flags, $boff, $blen, $aoff, $alen)
 211         = unpack("va[6]VVVVVVV", $data);
 212
 213     if ($mzmagic == 0x5a4d) {
 214         # It is an EFI file... search for the magic number
 215         $hdroffset = 48;
 216         my $magic = pack("VVVV", 0x2a171ead, 0x0600e65e,
 217                          0x4025a4e4, 0x42388fc8);
 218
 219         while (1) {
 220             return undef unless (read($file, $data, 16) == 16);
 221             last if ($data eq $magic);
 222
 223             $hdroffset += 16;
 224         }
 225
 226         return undef unless (read($file, $data, 16) == 16);
 227         ($blen, $alen, $bufsize, $junk) = unpack("VVVV", $data);
 228
 229         printf STDERR "EFI: offset = 0x%x, blen = %d, alen = %d, bufsize = %d\n", $hdroffset, $blen, $alen, $bufsize;
 230
 231         $patch_start = $boff = $hdroffset + 32;
 232         $aoff = $boff + $blen;
 233
 234         $hdr{'deep'} = 1;
 235         $hdr{'bufsize'} = $bufsize;
 236         $hdr{'hdroffset'} = $hdroffset;
 237     } else {
 238         # It is a BIOS PXE file
 239
 240         return undef if ($magic != 0x2983c8ac);
 241         return undef if ($len < 7*4);
 242
 243         $hdr{'deep'} = 0;
 244     }
 245
 246     if ($blen == 0) {
 247         $bdata = '';
 248     } else {
 249         return undef unless (seek($file, $boff, SEEK_SET));
 250         return undef unless (read($file, $bdata, $blen) == $blen);
 251         $patch_start = $boff if ($boff < patch_start);
 252     }
 253
 254     if ($alen == 0) {
 255         $adata = '';
 256     } else {
 257         return undef unless (seek($file, $aoff, SEEK_SET));
 258         return undef unless (read($file, $adata, $alen) == $alen);
 259         $patch_start = $aoff if ($aoff < $patch_start);
 260     }
 261
 262     $hdr{'patch_start'} = $patch_start;
 263
 264     return (\%hdr, $bdata, $adata);
 265 }
 266
 267 sub write_optsets($$$@)
 268 {
 269     my($file, $hdr, $bdata, $adata) = @_;
 270     my $boff = 0;
 271     my $aoff = 0;
 272     my $bufsize = 0;
 273     my $patch_start = $hdr->{'patch_start'};
 274     my $len;
 275
 276     $bdata .= "\xff" unless ($bdata eq '');
 277     $adata .= "\xff" unless ($adata eq '');
 278
 279     $len = length($bdata) + length($adata);
 280
 281     if (defined($hdr->{'bufsize'})) {
 282         return undef unless ($len <= $hdr->{'bufsize'});
 283     }
 284
 285     return undef unless (seek($file, $patch_start, SEEK_SET));
 286
 287     if (length($bdata)) {
 288         $boff = $patch_start;
 289         return undef unless (print $file $bdata);
 290         $patch_start += length($bdata);
 291     }
 292
 293     if (length($adata)) {
 294         $aoff = $patch_start;
 295         return undef unless (print $file $adata);
 296         $patch_start += length($adata);
 297     }
 298
 299     if ($hdr->{'deep'}) {
 300         return undef unless (print $file "\0" x ($hdr->{'bufsize'} - $len));
 301         return undef unless (seek($file, $hdr->{'hdroffset'} + 16, SEEK_SET));
 302         my $hdr = pack("VV", length($bdata), length($adata));
 303         return undef unless (print $file $hdr);
 304     } else {
 305         my $hdr = pack("VVVV", $boff, length($bdata), $aoff, length($adata));
 306
 307         return undef unless (seek($file, 8+3*4, SEEK_SET));
 308         return undef unless (print $file $hdr);
 309
 310         truncate($file, $patch_start);
 311     }
 312
 313     return 1;
 314 }
 315
 316 sub delete_option($$)
 317 {
 318     my ($num, $block) = @_;
 319     my $o, $l, $c, $x;
 320
 321     $x = 0;
 322     while ($x < length($block)) {
 323         ($o, $l) = unpack("CC", substr($block, $x, 2));
 324         if ($o == $num) {
 325             # Delete this option
 326             substr($block, $x, $l+2) = '';
 327         } elsif ($o == 0) {
 328             # Delete a null option
 329             substr($block, $x, 1) = '';
 330         } elsif ($o == 255) {
 331             # End marker - truncate block
 332             $block = substr($block, 0, $x);
 333             last;
 334         } else {
 335             # Skip to the next option
 336             $x += $l+2;
 337         }
 338     }
 339
 340     return $block;
 341 }
 342
 343 sub add_option($$$)
 344 {
 345     my ($num, $data, $block) = @_;
 346
 347     $block = delete_option($num, $block);
 348
 349     if (length($data) == 0) {
 350         return $block;
 351     } elsif (length($data) > 255) {
 352         die "$0: option $num has too much data (max 255 bytes)\n";
 353     } else {
 354         return $block . pack("CC", $num, length($data)) . $data;
 355     }
 356 }
 357
 358 sub list_options($$)
 359 {
 360     my($pfx, $data) = @_;
 361     my $x, $o, $l;
 362
 363     while ($x < length($data)) {
 364         ($o, $l) = unpack("CC", substr($data, $x, 2));
 365
 366         if ($o == 0) {
 367             $x++;
 368         } elsif ($o == 255) {
 369             last;
 370         } else {
 371             my $odata = substr($data, $x+2, $l);
 372             last if (length($odata) != $l); # Incomplete option
 373
 374             printf "%s%-20s %s\n", $pfx,
 375                 $option_names{$o} || sprintf("%d", $o),
 376                 show_option($o, $odata);
 377
 378             $x += $l+2;
 379         }
 380     }
 381 }
 382
 383 sub usage()
 384 {
 385     my $i;
 386
 387     print STDERR "Usage: $0 options pxelinux.0\n";
 388     print STDERR "Options:\n";
 389     print STDERR "--before option value   -b   Add an option before DHCP data\n";
 390     print STDERR "--after  option value   -a   Add an option after DHCP data\n";
 391     print STDERR "--delete option         -d   Delete an option\n";
 392     print STDERR "--list                  -l   List set options\n";
 393     print STDERR "--dry-run               -n   Don't modify the target file\n";
 394     print STDERR "--help                  -h   Display this help text\n";
 395     print STDERR "\n";
 396     print STDERR "The following DHCP options are currently recognized:\n";
 397     printf STDERR "%-23s %-3s  %s\n", 'Name', 'Num', 'Value Format';
 398
 399     foreach $i (sort { $a <=> $b } keys(%option_names)) {
 400         printf STDERR "%-23s %3d  %s\n",
 401                 $option_names{$i}, $i, $option_format{$i}[0];
 402     }
 403 }
 404
 405 %option_rnames = ();
 406 foreach $opt (keys(%option_names)) {
 407     $option_rnames{$option_names{$opt}} = $opt;
 408 }
 409
 410 %before   = ();
 411 %after    = ();
 412 @clear    = ();
 413 $usage    = 0;
 414 $err      = 0;
 415 $list     = 0;
 416 $no_write = 0;
 417 undef $file;
 418
 419 while (defined($opt = shift(@ARGV))) {
 420     if ($opt !~ /^-/) {
 421         if (defined($file)) {
 422             $err = $usage = 1;
 423             last;
 424         }
 425         $file = $opt;
 426     } elsif ($opt eq '-b' || $opt eq '--before') {
 427         $oname = shift(@ARGV);
 428         $odata = shift(@ARGV);
 429
 430         if (!defined($odata)) {
 431             $err = $usage = 1;
 432             last;
 433         }
 434
 435         $onum = option_number($oname);
 436         if (!defined($onum)) {
 437             print STDERR "$0: unknown option name: $oname\n";
 438             $err = 1;
 439             next;
 440         }
 441
 442         $odata = parse_option($onum, $odata);
 443         if (!defined($odata)) {
 444             print STDERR "$0: unable to parse data for option $oname\n";
 445             $err = 1;
 446             next;
 447         }
 448
 449         delete $after{$onum};
 450         $before{$onum} = $odata;
 451         push(@clear, $onum);
 452     } elsif ($opt eq '-a' || $opt eq '--after') {
 453         $oname = shift(@ARGV);
 454         $odata = shift(@ARGV);
 455
 456         if (!defined($odata)) {
 457             $err = $usage = 1;
 458             last;
 459         }
 460
 461         $onum = option_number($oname);
 462         if (!defined($onum)) {
 463             print STDERR "$0: unknown option name: $oname\n";
 464             $err = 1;
 465             next;
 466         }
 467
 468         $odata = parse_option($onum, $odata);
 469         if (!defined($odata)) {
 470             print STDERR "$0: unable to parse data for option $oname\n";
 471             $err = 1;
 472             next;
 473         }
 474
 475         delete $before{$onum};
 476         $after{$onum} = $odata;
 477         push(@clear, $onum);
 478     } elsif ($opt eq '-d' || $opt eq '--delete') {
 479         $oname = shift(@ARGV);
 480
 481         if (!defined($oname)) {
 482             $err = $usage = 1;
 483             last;
 484         }
 485
 486         $onum = option_number($oname);
 487         if (!defined($onum)) {
 488             print STDERR "$0: unknown option name: $oname\n";
 489             $err = 1;
 490             next;
 491         }
 492
 493         push(@clear, $onum);
 494         delete $before{$onum};
 495         delete $after{$onum};
 496     } elsif ($opt eq '-n' || $opt eq '--no-write' || $opt eq '--dry-run') {
 497         $no_write = 1;
 498     } elsif ($opt eq '-l' || $opt eq '--list') {
 499         $list = 1;
 500     } elsif ($opt eq '-h' || $opt eq '--help') {
 501         $usage = 1;
 502     } else {
 503         print STDERR "Invalid option: $opt\n";
 504         $err = $usage = 1;
 505     }
 506 }
 507
 508 if (!defined($file) && !$usage) {
 509     $err = $usage = 1;
 510 }
 511 if ($usage) {
 512     usage();
 513 }
 514 if ($err || $usage) {
 515     exit($err);
 516 }
 517
 518 if (!scalar(@clear)) {
 519     $no_write = 1;              # No modifications requested
 520 }
 521
 522 $mode = $no_write ? '<' : '+<';
 523
 524 open(FILE, $mode, $file)
 525     or die "$0: cannot open: $file: $!\n";
 526 ($hdrinfo, @data) = read_optsets(\*FILE);
 527 if (!defined($hdrinfo)) {
 528     die "$0: $file: patch block not found or file corrupt\n";
 529 }
 530
 531 foreach $o (@clear) {
 532     $data[0] = delete_option($o, $data[0]);
 533     $data[1] = delete_option($o, $data[1]);
 534 }
 535 foreach $o (keys(%before)) {
 536     $data[0] = add_option($o, $before{$o}, $data[0]);
 537 }
 538 foreach $o (keys(%after)) {
 539     $data[1] = add_option($o, $after{$o}, $data[1]);
 540 }
 541
 542 if ($list) {
 543     list_options('-b ', $data[0]);
 544     list_options('-a ', $data[1]);
 545 }
 546
 547 if (!$no_write) {
 548     if (!write_optsets(\*FILE, $hdrinfo, @data)) {
 549         die "$0: $file: failed to write options: $!\n";
 550     }
 551 }
 552
 553 close(FILE);
 554 exit 0;