On Tue, May 23, 2017 at 03:00:57AM +0200, Alexander Bluhm wrote:
> Hi,
>
> I would like to move the common length check in pf_pull_hdr() after
> the address family switch. This makes the specific calculation
> more obvious.
>
> ok?
OK
> bluhm
>
> Index: net/pf.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/sys/net/pf.c,v
> retrieving revision 1.1026
> diff -u -p -r1.1026 pf.c
> --- net/pf.c 20 May 2017 22:56:43 -0000 1.1026
> +++ net/pf.c 23 May 2017 00:48:35 -0000
> @@ -5611,6 +5611,8 @@ void *
> pf_pull_hdr(struct mbuf *m, int off, void *p, int len,
> u_short *actionp, u_short *reasonp, sa_family_t af)
> {
> + int iplen = 0;
> +
> switch (af) {
> case AF_INET: {
> struct ip *h = mtod(m, struct ip *);
> @@ -5625,28 +5627,22 @@ pf_pull_hdr(struct mbuf *m, int off, voi
> }
> return (NULL);
> }
> - if (m->m_pkthdr.len < off + len ||
> - ntohs(h->ip_len) < off + len) {
> - ACTION_SET(actionp, PF_DROP);
> - REASON_SET(reasonp, PFRES_SHORT);
> - return (NULL);
> - }
> + iplen = ntohs(h->ip_len);
> break;
> }
> #ifdef INET6
> case AF_INET6: {
> struct ip6_hdr *h = mtod(m, struct ip6_hdr *);
>
> - if (m->m_pkthdr.len < off + len ||
> - (ntohs(h->ip6_plen) + sizeof(struct ip6_hdr)) <
> - (unsigned)(off + len)) {
> - ACTION_SET(actionp, PF_DROP);
> - REASON_SET(reasonp, PFRES_SHORT);
> - return (NULL);
> - }
> + iplen = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr);
> break;
> }
> #endif /* INET6 */
> + }
> + if (m->m_pkthdr.len < off + len || iplen < off + len) {
> + ACTION_SET(actionp, PF_DROP);
> + REASON_SET(reasonp, PFRES_SHORT);
> + return (NULL);
> }
> m_copydata(m, off, len, p);
> return (p);
>
--
:wq Claudio
