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|
#!/usr/bin/perl -w
use strict;
use FileHandle;
my $cmdline = join(' ',$0,@ARGV);
my $out = shift(@ARGV) or die "need output file";
my $in = shift(@ARGV) or die "need input file";
my $inh = new FileHandle $in, "r" or die "could not open file $in";
my $newh="$out.h.perlnew";
open(HEADER,">$newh");
open(SOURCE,">$out.c");
print SOURCE "/* this file was automatically generated by $cmdline */
#include \"base.h\"
\n";
my @funcnames=();
my @lines=<$inh>;
my $funcre=qr/(\w+\s*\*?)\s+(\w+)\s*\((.*)\)\s*;/;
foreach(@lines) {
s"#.*"";
s"//.*"";
if(m"^\s*$") {next}
unless(/$funcre/) {next}
my $rettype=$1;
my $funcname=$2;
my $params=$3;
print HEADER "#if defined(__NR_$funcname)\n";
print HEADER "extern $rettype redirecting_sys_$funcname($params);\n";
print HEADER "extern $rettype (*orig_sys_$funcname)($params);\n";
print HEADER "#endif\n";
print SOURCE "#if defined(__NR_$funcname)\n";
print SOURCE "$rettype (*orig_sys_$funcname)($params);\n";
print SOURCE "#endif\n";
push(@funcnames,$funcname);
}
print SOURCE "
#define redir(a,b,c) b=sys_call_table[a];sys_call_table[a]=c
#define unredir(a,b,c) sys_call_table[a]=b
/* redirect syscalls (save old, install new) */
void init_redir_calltable(void)
{
";
foreach(@funcnames) {
print SOURCE "#if defined( __NR_$_)\n";
print SOURCE "\tredir(__NR_$_, orig_sys_$_, redirecting_sys_$_);\n";
print SOURCE "#endif\n";
}
print SOURCE "}
/* unredirect syscalls
this is problematic when several syscall-redirecting modules are loaded
and not unloaded in reverse order!!!
*/
void restore_redir_calltable(void)
{
";
foreach(@funcnames) {
print SOURCE "#if defined(__NR_$_)\n";
print SOURCE "\tunredir(__NR_$_, orig_sys_$_, redirecting_sys_$_);\n";
print SOURCE "#endif\n";
}
print SOURCE "}\n\n";
foreach(@lines) {
if(m"^\s*$") {next}
my $symfollow=0; while(s/^\^//g) {$symfollow++;}
my $creation=0; while(s/^://g) {$creation++;}
my $headonly=0; while(s/^-//g) {$headonly++;}
my $redirtype=0; while(s/^\+//g) {$redirtype++;}
my $redirflags=("0","LOOKUP_MKDIR","LOOKUP_MKDIR|LOOKUP_CREATE")[$redirtype];
unless(/$funcre/) {next}
if($headonly>1) {next}
my $rettype=$1;
my $funcname=$2;
my $params=$3;
my @params=split(/\s*,\s*/,$params);
my @paramnames=();
my @localparams=();
my @localdefs=();
my @inputcopy=();
my @outputcopy=();
my @redir=();
my $varcount=0;
my $xn;
my $lastresult="rresult";
my $laststr;
my $firststr;
if($creation&1) { $redirflags.="|LOOKUP_CREATES" }
if($symfollow&1) { $redirflags.="|LOOKUP_NOFOLLOW" }
foreach(@params) {
/(\w+)$/;
my $name=$1;push(@paramnames,$name);
if(/(.*)\*\s*\w+$/){
my $n="local$varcount";
local $_=$1;
my $input=s/const//g;s/^\s*//;s/\s*$//;
my $def="\t$_ $n";
my $addr="";
my $pn=$paramnames[$varcount];
my $nn=$params[$varcount+1];
$nn=~s/.*\W// if $nn; # name of following var
if(/char/) {
$def.="[REDIR_BUFSIZE]";
$firststr=$n unless defined $firststr;
if($input) {
my $ispath=($pn=~/path|file/);
push(@inputcopy,"if(strncpy_from_user($n, $pn, REDIR_BUFSIZE)<0) return -EFAULT;");
if($ispath){
$laststr=$n;
if($varcount>=1){push(@localdefs,"\tint rresult2;");$lastresult="rresult2";push(@inputcopy,"if((rresult2=redirect2($n, $redirflags))<0) return rresult2;");}}
push(@redir,[$n,$pn,$lastresult,$redirflags]);
} else {
$xn=$n."size";
splice(@inputcopy,1,0,"size_t $xn=($nn<REDIR_BUFSIZE?$nn:REDIR_BUFSIZE);");
push(@outputcopy,"if(result>=0){if(copy_to_user($pn, $n, result)) return -EFAULT;}")
}
} elsif(/void/) {
$addr="p";
$def=~s/$n/*p$n=NULL/;
push(@inputcopy,"if($nn>0 && $pn) { p$n=kmalloc($nn,GFP_KERNEL); }");
if($input) {
$inputcopy[-1]=~s/}/if(copy_from_user(p$n, $pn, $nn)) {kfree(p$n);return -EFAULT;} }/;
}
else {
push(@outputcopy,"if(p$n && result>=0 && $nn>0 && copy_to_user($paramnames[$varcount], p$n, result)) {kfree(p$n);return -EFAULT;}");
}
push(@outputcopy,"if(p$n) kfree(p$n);");
} else {
if($input) {$addr="p"; $def.=", *p$n=NULL";push(@inputcopy,"if($pn && copy_from_user((p$n=&$n), $pn, sizeof($n))) return -EFAULT;")}
else {$addr="&"; push(@outputcopy,"if(copy_to_user($pn, &$n, sizeof($n))) return -EFAULT;")}
}
push(@localdefs,$def.";");
push(@localparams,"$addr$n");
} else {
if($xn) { $name=$xn; $xn=undef; }
push(@localparams,$name);
}
$varcount++;
}
my $manyargs=$laststr ne $firststr;
if($funcname eq "symlink") {my $h=$inputcopy[1];$inputcopy[1]=$inputcopy[0];$inputcopy[0]=$h;$firststr=$laststr;$inputcopy[2]="";$localdefs[1]="";$lastresult="rresult";}
if($creation&1) {
push(@inputcopy, "if($lastresult&4) BEGIN_KMEM orig_sys_unlink($laststr); END_KMEM");
push(@outputcopy, "if(result<0 && $lastresult&4) translucent_create_whiteout($laststr);");
}
if($creation&2) { push(@outputcopy, "if(result==0 && (rresult&2) && !(translucent_flags&no_whiteout)) translucent_create_whiteout(local0);"); }
# individual patches
if($funcname eq "access") {$redirflags.="|(mode==2/*W_OK*/?LOOKUP_MKDIR|LOOKUP_CREATE:0)"}
if($funcname eq "mkdir") {$inputcopy[0].=" rresult=strlen(local0)-1;if(local0[rresult]=='/'){local0[rresult]=0;}";}
if($funcname eq "link") {$redirflags="0"}
if($funcname eq "rename") {$redirflags=~s/\|LOOKUP_CREATES//}
if($funcname eq "unlink") {$redirflags.="|LOOKUP_TRUNCATE";}
my $paramnames=join(", ", @paramnames);
my $localdefs=join("\n",@localdefs); #"char local0[REDIR_BUFSIZE+1];";
my $localparams=join(", ", @localparams);
my $inputcopy=""; foreach(@inputcopy[1..$#inputcopy]) {$inputcopy.="\n\t\t".$_};
my $outputcopy=""; foreach(@outputcopy) { $outputcopy.="\n\t\t".$_}
print SOURCE "#if defined(__NR_$funcname)
$rettype redirecting_sys_$funcname($params)\n{\n\tint rresult;\n";
unless($headonly) {
print SOURCE "$localdefs
$inputcopy[0]
if((rresult=redirect2($firststr, $redirflags))>0) {
$rettype result;$inputcopy
BEGIN_KMEM
result = orig_sys_$funcname($localparams);
END_KMEM$outputcopy
if(no_fallback(result)) return result;
}
if(rresult<0) return rresult;
return orig_sys_$funcname($paramnames);
";}
print SOURCE "}\n#endif\n\n";
}
print SOURCE "\n/* EOF */\n";
close(SOURCE);
close(HEADER);
# prevent recompiling all files on running makeext.pl with no header changes
system("diff", "--brief", "-N", "$out.h", $newh);
my $diff=$? >> 8;
if($diff) { rename($newh, "$out.h") }
else { unlink($newh); }
|
