On Mon, Feb 18, 2008 at 03:20:37PM +0100, Jim Meyering wrote:
> "Daniel P. Berrange" <berrange@xxxxxxxxxx> wrote:
> > +static int virStorageSize(virConnectPtr conn,
> > + const char *unit,
> > + const char *val,
> > + unsigned long long *ret) {
> > + unsigned long long mult;
> > + char *end;
> > +
> > + if (!unit) {
> > + mult = 1;
> > + } else {
> > + switch (unit[0]) {
> > + case 'k':
> > + case 'K':
> > + mult = 1024ull;
> > + break;
> > +
> > + case 'm':
> > + case 'M':
> > + mult = 1024ull * 1024ull;
> > + break;
> > +
> > + case 'g':
> > + case 'G':
> > + mult = 1024ull * 1024ull * 1024ull;
> > + break;
> > +
> > + case 't':
> > + case 'T':
> > + mult = 1024ull * 1024ull * 1024ull * 1024ull;
> > + break;
>
> From our current perspective, 'T' looks big enough, but you might want
> to add 'P', 'Y', and 'Z', if only so the code doesn't seem clueless
> when reporting "unknown size units" :-)
Yeah, might as well.
> > + *ret = strtoull(val, &end, 10);
> > + if (end && *end) {
> > + virStorageReportError(conn, VIR_ERR_XML_ERROR, "malformed capacity element");
> > + return -1;
> > + }
> > + *ret *= mult;
>
> If you change the guard to e.g.,
>
> if (*end || *ret > ULLONG_MAX / mult) {
> virStorageReportError(conn, VIR_ERR_XML_ERROR,
> "malformed capacity element");
>
> you avoid risk of overflow.
Ok, thanks
Dan.
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