[Dnsmasq-discuss] integer overflow in src/dnsmasq.h ?!

Stefan Krüger stadtkind2 at gmx.de
Tue Jun 17 17:23:49 BST 2008

hello list,

I'm trying to compile dnsmasq (2.43test4) with Sun Studio 12 on

I got some warnings, like:

cc -g -errtags=yes     -DSUNOS_VER=10  -c rfc1035.c
"rfc1035.c", line 779: warning: integer overflow detected: op "<<"

line 779 in rfc1035.c is

if ((daemon->options & OPT_NO_REBIND) &&
     (flags & F_IPV4) &&
	return 1;

I checked OPT_NO_REBIND which is defined in src/dnsmasq.h

#define OPT_NO_REBIND      (1<<31)

which looks indeed like an integer overflow.

So my question, is this warning serious? Could I fix it like:

#define OPT_NO_REBIND      (1u<<31)


The next error was:

cc -g -errtags=yes -errwarn=%all     -DSUNOS_VER=10  -c option.c
"option.c", line 302: warning: initializer does not fit or is out of
range: 0x80000000 (E_INIT_DOES_NOT_FIT)

I fixed this by changing int to unsigned in src/option.c (line 209):

static struct {
   unsigned int opt, rept;

I also had some problems with __sun__ #defines, which don't work with 
Sun Studio 12's cc, I had to replace them with __sun


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