Re: CVS commit: src/sys/net

[christos%zoulas.com@localhost (Christos Zoulas)]

On Dec 29, 11:56pm, alnsn%yandex.ru@localhost (Alexander Nasonov) wrote:
-- Subject: Re: CVS commit: src/sys/net

| Christos Zoulas wrote:
| > On Dec 29, 10:09pm, alnsn%yandex.ru@localhost (Alexander Nasonov) wrote:
| > | Not sure FreeBSD got BPF_IND case right. They basically disabled using
| > | big positive values of pc->k for small negative values. They could just
| > | copy code from BPF_ABS case:
| > | 
| > | > +                       if (k > buflen || sizeof(int16_t) > buflen - k) 
{
| > | 
| > | but they didn't. Can we assume that loads with negative offsets relative
| > | to X (e.g. P[X-1:4]) are not allowed by bpf?
| > 
| > I suppose by turning k unsigned, they really want to disable negative 
offsets.
| > We could allow them if needed, but at that point it is better to make k 
signed.
| 
| I wish they stated it explicitly in bpf(4). Can I document it in our
| bpf(4)?

Sure, please do.

christos