M1: compat layer + pf.ko skeleton builds against Linux 7.3.4

- pfk.h: BSD types/ioctl encoding (OpenBSD bit layout), locks (NET_LOCK=rwsem),
  pools, timeouts, mbuf shim over sk_buff, ifnet registry, toeplitz/siphash
- pfk_mod/pfk_hooks: misc /dev/pf (0600), IPv4 netfilter hook skeleton,
  DIOCGETSTATUS answered (M1 skeleton; engine ioctls land with pf_ioctl.c)
- vendorize/stage-port scripts: deterministic upstream staging with seds
  (struct renames, IFF_*->PFIFF_*, sa_len drops) logged to docs/porting-notes
- fixes: modules_prepare+Module.symvers for out-of-tree builds

module/pfsrc/if_pflog.c

@@ -0,0 +1,193 @@
+/* PFLINUX port of OpenBSD 8.0 net/if_pflog.c — see docs/porting-notes.md */
+#include <pfk.h>
+
+#define PFLOGMTU	(32768 + MHLEN + MLEN)
+
+#ifdef PFLOGDEBUG
+#define DPRINTF(x)    do { if (pflogdebug) printf x ; } while (0)
+#else
+#define DPRINTF(x)
+#endif
+
+void	pflogattach(int);
+int	pflogoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
+		       struct rtentry *);
+int	pflogioctl(struct ifnet *, u_long, caddr_t);
+int	pflog_clone_create(struct if_clone *, int);
+int	pflog_clone_destroy(struct ifnet *);
+struct	pflog_softc	*pflog_getif(int);
+
+struct if_clone			pflog_cloner =
+    IF_CLONE_INITIALIZER("pflog", pflog_clone_create, pflog_clone_destroy);
+
+LIST_HEAD(, pflog_softc)	pflog_ifs = LIST_HEAD_INITIALIZER(pflog_ifs);
+
+void
+pflogattach(int npflog)
+{
+	if_clone_attach(&pflog_cloner);
+}
+
+int
+pflog_clone_create(struct if_clone *ifc, int unit)
+{
+	struct ifnet *ifp;
+	struct pflog_softc *pflogif;
+
+	pflogif = malloc(sizeof(*pflogif), M_DEVBUF, M_WAITOK|M_ZERO);
+	pflogif->sc_unit = unit;
+	ifp = &pflogif->sc_if;
+	snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", unit);
+	ifp->if_softc = pflogif;
+	ifp->if_mtu = PFLOGMTU;
+	ifp->if_ioctl = pflogioctl;
+	ifp->if_output = pflogoutput;
+	ifp->if_xflags = IFXF_CLONED;
+	ifp->if_type = IFT_PFLOG;
+	ifp->if_hdrlen = PFLOG_HDRLEN;
+	if_attach(ifp);
+	if_alloc_sadl(ifp);
+
+#if NBPFILTER > 0
+	bpfattach(&pflogif->sc_if.if_bpf, ifp, DLT_PFLOG, PFLOG_HDRLEN);
+#endif
+
+	NET_LOCK();
+	LIST_INSERT_HEAD(&pflog_ifs, pflogif, sc_entry);
+	NET_UNLOCK();
+
+	return (0);
+}
+
+int
+pflog_clone_destroy(struct ifnet *ifp)
+{
+	struct pflog_softc	*pflogif = ifp->if_softc;
+
+	NET_LOCK();
+	LIST_REMOVE(pflogif, sc_entry);
+	NET_UNLOCK();
+
+	if_detach(ifp);
+	free(pflogif, M_DEVBUF, sizeof(*pflogif));
+
+	return (0);
+}
+
+int
+pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
+	struct rtentry *rt)
+{
+	m_freem(m);	/* drop packet */
+	return (EAFNOSUPPORT);
+}
+
+int
+pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
+{
+	switch (cmd) {
+	case SIOCSIFFLAGS:
+		if (ifp->if_flags & PFIFF_UP)
+			ifp->if_flags |= PFIFF_RUNNING;
+		else
+			ifp->if_flags &= ~PFIFF_RUNNING;
+		break;
+	default:
+		return (ENOTTY);
+	}
+
+	return (0);
+}
+
+struct pflog_softc *
+pflog_getif(int unit)
+{
+	struct pflog_softc *pflogif;
+
+	NET_ASSERT_LOCKED();
+
+	LIST_FOREACH(pflogif, &pflog_ifs, sc_entry) {
+		if (pflogif->sc_unit == unit)
+			break;
+	}
+
+	return pflogif;
+}
+
+int
+pflog_packet(struct pf_pdesc *pd, u_int8_t reason, struct pf_rule *rm,
+    struct pf_rule *am, struct pf_ruleset *ruleset, struct pf_rule *trigger)
+{
+#if NBPFILTER > 0
+	struct pflog_softc *pflogif;
+	struct ifnet *ifn;
+	caddr_t if_bpf;
+	struct pfloghdr hdr;
+
+	if (rm == NULL || pd == NULL || pd->kif == NULL || pd->m == NULL)
+		return (-1);
+	if (trigger == NULL)
+		trigger = rm;
+	pflogif = pflog_getif(trigger->logif);
+	if (pflogif == NULL)
+		return (0);
+	ifn = &pflogif->sc_if;
+	if_bpf = ifn->if_bpf;
+	if (!if_bpf)
+		return (0);
+
+	bzero(&hdr, sizeof(hdr));
+	hdr.length = PFLOG_REAL_HDRLEN;
+	/* Default rule does not pass packets dropped for other reasons. */
+	hdr.action = (rm->nr == (u_int32_t)-1 && reason != PFRES_MATCH) ?
+	    PF_DROP : rm->action;
+	hdr.reason = reason;
+	memcpy(hdr.ifname, pd->kif->pfik_name, sizeof(hdr.ifname));
+
+	if (am == NULL) {
+		hdr.rulenr = htonl(rm->nr);
+		hdr.subrulenr = -1;
+	} else {
+		hdr.rulenr = htonl(am->nr);
+		hdr.subrulenr = htonl(rm->nr);
+		if (ruleset != NULL && ruleset->anchor != NULL)
+			strlcpy(hdr.ruleset, ruleset->anchor->name,
+			    sizeof(hdr.ruleset));
+	}
+	if (trigger->log & PF_LOG_USER && !pd->lookup.done)
+		pd->lookup.done = pf_socket_lookup(pd);
+	if (trigger->log & PF_LOG_USER && pd->lookup.done > 0) {
+		hdr.uid = pd->lookup.uid;
+		hdr.pid = pd->lookup.pid;
+	} else {
+		hdr.uid = -1;
+		hdr.pid = NO_PID;
+	}
+	hdr.rule_uid = rm->cuid;
+	hdr.rule_pid = rm->cpid;
+	hdr.dir = pd->dir;
+	hdr.af = pd->af;
+
+	if (pd->src != NULL && pd->dst != NULL) {
+		if (pd->af != pd->naf ||
+		    pf_addr_compare(pd->src, &pd->nsaddr, pd->naf) != 0 ||
+		    pf_addr_compare(pd->dst, &pd->ndaddr, pd->naf) != 0 ||
+		    pd->osport != pd->nsport ||
+		    pd->odport != pd->ndport) {
+			hdr.rewritten = 1;
+		}
+	}
+	hdr.naf = pd->naf;
+	pf_addrcpy(&hdr.saddr, &pd->nsaddr, pd->naf);
+	pf_addrcpy(&hdr.daddr, &pd->ndaddr, pd->naf);
+	hdr.sport = pd->nsport;
+	hdr.dport = pd->ndport;
+
+	ifn->if_opackets++;
+	ifn->if_obytes += pd->m->m_pkthdr.len;
+
+	bpf_mtap_hdr(if_bpf, &hdr, sizeof(hdr), pd->m, BPF_DIRECTION_OUT);
+#endif
+
+	return (0);
+}