M2: live netfilter data path (pf_test per direction), pfattach bring-up, NET_LOCK reentrancy fix, static pfctl

- pfk_hooks: PRE→PF_IN, LOCAL_OUT/POST→PF_OUT v4+v6; replacement/buffer
  handling with NF_STOLEN + re-injection (documented divergence: re-entry)
- pfk_mod: pf_status_init/pfattach + pfi attach via pfk_if event callback
- pfk_kern: NET_LOCK holder reentrancy (fix deadlock when notifier fires
  under the write lock — observed as full-VM network hang)
- tools: static pfctl link for musl VMs

tools/include/sys/ioctl.h

@@ -0,0 +1,45 @@
+/* PFLINUX: <sys/ioctl.h> — OpenBSD 8.0 ioctl encoding for userland pfctl.
+ *
+ * net/pfvar.h builds every DIOC* number with _IO/_IOW/_IOR/_IOWR.  pf.ko
+ * (see module/include/pfk.h) interprets ioctl commands using the OpenBSD
+ * sys/ioccom.h bit layout, NOT Linux asm/ioctl.h, so this header must
+ * reproduce pfk.h's PFKXIOC_* encoding byte-for-byte.  We pull in the real
+ * glibc <sys/ioctl.h> first (ioctl(2) prototype, Linux SIOC* constants used
+ * by <net/if.h>) and then redefine the _IO family.
+ *
+ * Values copied from module/include/pfk.h lines 135-152.
+ */
+#ifndef _PFLINUX_SYS_IOCTL_H
+#define _PFLINUX_SYS_IOCTL_H
+
+#include_next <sys/ioctl.h>
+
+#include <sys/types.h>
+
+#undef _IO
+#undef _IOR
+#undef _IOW
+#undef _IOWR
+
+#define PFKXIOC_NRBITS     8
+#define PFKXIOC_TYPEBITS   8
+#define PFKXIOC_SIZEBITS   13
+#define PFKXIOC_DIRBITS    2
+#define PFKXIOC_NRSHIFT    0
+#define PFKXIOC_TYPESHIFT  (PFKXIOC_NRSHIFT + PFKXIOC_NRBITS)
+#define PFKXIOC_SIZESHIFT  (PFKXIOC_TYPESHIFT + PFKXIOC_TYPEBITS)
+#define PFKXIOC_DIRSHIFT   (PFKXIOC_SIZESHIFT + PFKXIOC_SIZEBITS + 1)
+#define PFKXIOC_NONE       0U
+#define PFKXIOC_WRITE      1U	/* OpenBSD IOC_IN  (copyin)  */
+#define PFKXIOC_READ       2U	/* OpenBSD IOC_OUT (copyout) */
+
+#define PFKXIOC(dir,type,nr,size) \
+	(((dir)  << PFKXIOC_DIRSHIFT) | ((type) << PFKXIOC_TYPESHIFT) | \
+	 ((nr)   << PFKXIOC_NRSHIFT) | ((size) << PFKXIOC_SIZESHIFT))
+
+#define _IO(t, n)           PFKXIOC(PFKXIOC_NONE, (t), (n), 0)
+#define _IOWR(t, n, s)      PFKXIOC(PFKXIOC_WRITE|PFKXIOC_READ, (t), (n), sizeof(s))
+#define _IOW(t, n, s)       PFKXIOC(PFKXIOC_WRITE, (t), (n), sizeof(s))
+#define _IOR(t, n, s)       PFKXIOC(PFKXIOC_READ, (t), (n), sizeof(s))
+
+#endif /* _PFLINUX_SYS_IOCTL_H */