Add hierarchical jails. A jail may further virtualize its environment

by creating a child jail, which is visible to that jail and to any
parent jails.  Child jails may be restricted more than their parents,
but never less.  Jail names reflect this hierarchy, being MIB-style
dot-separated strings.

Every thread now points to a jail, the default being prison0, which
contains information about the physical system.  Prison0's root
directory is the same as rootvnode; its hostname is the same as the
global hostname, and its securelevel replaces the global securelevel.
Note that the variable "securelevel" has actually gone away, which
should not cause any problems for code that properly uses
securelevel_gt() and securelevel_ge().

Some jail-related permissions that were kept in global variables and
set via sysctls are now per-jail settings.  The sysctls still exist for
backward compatibility, used only by the now-deprecated jail(2) system
call.

Approved by:	bz (mentor)

2 files changed, 10 insertions, 0 deletions

diff --git a/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c b/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c
index fee97c5..3e0e633 100644
--- a/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c
+++ b/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c
@@ -318,8 +318,10 @@ int iplioctl(dev, cmd, data, mode
 #  if (__FreeBSD_version >= 500024)
 struct thread *p;
 #   if (__FreeBSD_version >= 500043)
+#    define	p_cred	td_ucred
 #    define	p_uid	td_ucred->cr_ruid
 #   else
+#    define	p_cred	t_proc->p_cred
 #    define	p_uid	t_proc->p_cred->p_ruid
 #   endif
 #  else
@@ -342,7 +344,11 @@ int mode;
 	SPL_INT(s);
 
 #if (BSD >= 199306) && defined(_KERNEL)
+# if (__FreeBSD_version >= 500034)
+	if (securelevel_ge(p->p_cred, 3) && (mode & FWRITE))
+# else
 	if ((securelevel >= 3) && (mode & FWRITE))
+# endif
 		return EPERM;
 #endif
 
diff --git a/sys/contrib/ipfilter/netinet/ip_nat.c b/sys/contrib/ipfilter/netinet/ip_nat.c
index d6f0b55..f790c7d 100644
--- a/sys/contrib/ipfilter/netinet/ip_nat.c
+++ b/sys/contrib/ipfilter/netinet/ip_nat.c
@@ -662,7 +662,11 @@ void *ctx;
 		return EPERM;
 	}
 # else
+#  if defined(__FreeBSD_version) && (__FreeBSD_version >= 500034)
+	if (securelevel_ge(curthread->td_ucred, 3) && (mode & FWRITE)) {
+#  else
 	if ((securelevel >= 3) && (mode & FWRITE)) {
+#  endif
 		return EPERM;
 	}
 # endif