Re: [PATCH 4/4] util: use uint32 instead of char[4] for several virSocketAddrIPv4 operations

On a Thursday in 2024, Laine Stump wrote: > [...] > +        startHost = ntohl(startv4.val); > +        endHost = ntohl(endv4.val); > + > +        if (endHost - startHost > 65535) { > +            virReportError(VIR_ERR_INTERNAL_ERROR, > +                           _("range %1$s - %2$s is too large (> > 65535)"), > +                           startStr, endStr); > +            return -1; >         } > -        ret = (t2.bytes[2] - t1.bytes[2]) * 256 + (t2.bytes[3] - > t1.bytes[3]); > -        if (ret < 0) { > + > +        if (endHost < startHost) { This check needs to happen before you subtract two unsigned integers, otherwise the substraction above overflows and this is essentially dead code. Before this patch: $ VIR_TEST_RANGE=48 VIR_TEST_DEBUG=1 ./run tests/sockettest TEST: sockettest 48) Test range 192.168.122.20 -> 192.168.122.1(192.168.122.1/24) size -1 ... libvirt:  error : internal error: range 192.168.122.20 - 192.168.122.1 is reversed OK After: $ VIR_TEST_RANGE=48 VIR_TEST_DEBUG=1 ./run tests/sockettest TEST: sockettest 48) Test range 192.168.122.20 -> 192.168.122.1(192.168.122.1/24) size -1 ... libvirt:  error : internal error: range 192.168.122.20 - 192.168.122.1 is too large (> 65535) OK