Place hostnames and similar information fully under the prison system.

The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex.  Jails may
have their own host information, or they may inherit it from the
parent/system.  The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL.  The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.

The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.

Approved by:	bz (mentor)

1 files changed, 5 insertions, 11 deletions

diff --git a/sys/i386/ibcs2/ibcs2_socksys.c b/sys/i386/ibcs2/ibcs2_socksys.c
index 2dba77d..eb0559e 100644
--- a/sys/i386/ibcs2/ibcs2_socksys.c
+++ b/sys/i386/ibcs2/ibcs2_socksys.c
@@ -31,10 +31,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/sysproto.h>
 #include <sys/jail.h>
 #include <sys/kernel.h>
-#include <sys/lock.h>
-#include <sys/mutex.h>
 #include <sys/sysctl.h>
-#include <sys/vimage.h>
 
 #include <i386/ibcs2/ibcs2_socksys.h>
 #include <i386/ibcs2/ibcs2_util.h>
@@ -152,7 +149,7 @@ ibcs2_getipdomainname(td, uap)
 	char hname[MAXHOSTNAMELEN], *dptr;
 	int len;
 
-	/* Get the domain name */
+	/* Get the domain name. */
 	getcredhostname(td->td_ucred, hname, sizeof(hname));
 
 	dptr = index(hname, '.');
@@ -174,20 +171,17 @@ ibcs2_setipdomainname(td, uap)
         struct thread *td;
         struct setipdomainname_args *uap;
 {
-	INIT_VPROCG(TD_TO_VPROCG(td));
 	char hname[MAXHOSTNAMELEN], *ptr;
 	int error, sctl[2], hlen;
 
+	/* Get the domain name */
+	getcredhostname(td->td_ucred, hname, sizeof(hname));
+
 	/* W/out a hostname a domain-name is nonsense */
-	mtx_lock(&hostname_mtx);
-	if ( strlen(V_hostname) == 0 ) {
-		mtx_unlock(&hostname_mtx);
+	if ( strlen(hname) == 0 )
 		return EINVAL;
-	}
 
 	/* Get the host's unqualified name (strip off the domain) */
-	snprintf(hname, sizeof(hname), "%s", V_hostname);
-	mtx_unlock(&hostname_mtx);
 	ptr = index(hname, '.');
 	if ( ptr != NULL ) {
 		ptr++;