From 51ea07d722bb4ddb97fc0ba5616d6e34c58f80ca Mon Sep 17 00:00:00 2001
From: Pawel Jakub Dawidek <pjd@FreeBSD.org>
Date: Thu, 14 Mar 2013 23:14:47 +0000
Subject: [PATCH] Now that ioctl(2) is allowed in capability mode and we can
 limit ioctls for the given descriptors, use Capsicum sandboxing for hastd in
 primary and secondary modes. Allow for DIOCGDELETE and DIOCGFLUSH ioctls on
 provider descriptor and for G_GATE_CMD_MODIFY, G_GATE_CMD_START,
 G_GATE_CMD_DONE and G_GATE_CMD_DESTROY on GEOM Gate descriptor.

Sponsored by:	The FreeBSD Foundation
---
 sbin/hastd/subr.c | 64 +++++++++++++++++++++++++++++++++++------------
 1 file changed, 48 insertions(+), 16 deletions(-)

diff --git a/sbin/hastd/subr.c b/sbin/hastd/subr.c
index ae6f984013c..440061e8c36 100644
--- a/sbin/hastd/subr.c
+++ b/sbin/hastd/subr.c
@@ -31,14 +31,15 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#ifdef HAVE_CAPSICUM
-#include <sys/capability.h>
-#endif
 #include <sys/param.h>
 #include <sys/disk.h>
 #include <sys/ioctl.h>
 #include <sys/jail.h>
 #include <sys/stat.h>
+#ifdef HAVE_CAPSICUM
+#include <sys/capability.h>
+#include <geom/gate/g_gate.h>
+#endif
 
 #include <errno.h>
 #include <fcntl.h>
@@ -224,22 +225,53 @@ drop_privs(const struct hast_resource *res)
 		return (-1);
 	}
 
-	/*
-	 * Until capsicum doesn't allow ioctl(2) we cannot use it to sandbox
-	 * primary and secondary worker processes, as primary uses GGATE
-	 * ioctls and secondary uses ioctls to handle BIO_DELETE and BIO_FLUSH.
-	 * For now capsicum is only used to sandbox hastctl.
-	 */
 #ifdef HAVE_CAPSICUM
-	if (res == NULL) {
-		capsicum = (cap_enter() == 0);
-		if (!capsicum) {
-			pjdlog_common(LOG_DEBUG, 1, errno,
-			    "Unable to sandbox using capsicum");
+	capsicum = (cap_enter() == 0);
+	if (!capsicum) {
+		pjdlog_common(LOG_DEBUG, 1, errno,
+		    "Unable to sandbox using capsicum");
+	} else if (res != NULL) {
+		static const unsigned long geomcmds[] = {
+		    DIOCGDELETE,
+		    DIOCGFLUSH
+		};
+
+		PJDLOG_ASSERT(res->hr_role == HAST_ROLE_PRIMARY ||
+		    res->hr_role == HAST_ROLE_SECONDARY);
+
+		if (cap_rights_limit(res->hr_localfd,
+		    CAP_FLOCK | CAP_IOCTL | CAP_PREAD | CAP_PWRITE) == -1) {
+			pjdlog_errno(LOG_ERR,
+			    "Unable to limit capability rights on local descriptor");
 		}
-	} else
+		if (cap_ioctls_limit(res->hr_localfd, geomcmds,
+		    sizeof(geomcmds) / sizeof(geomcmds[0])) == -1) {
+			pjdlog_errno(LOG_ERR,
+			    "Unable to limit allowed GEOM ioctls");
+		}
+
+		if (res->hr_role == HAST_ROLE_PRIMARY) {
+			static const unsigned long ggatecmds[] = {
+			    G_GATE_CMD_MODIFY,
+			    G_GATE_CMD_START,
+			    G_GATE_CMD_DONE,
+			    G_GATE_CMD_DESTROY
+			};
+
+			if (cap_rights_limit(res->hr_ggatefd, CAP_IOCTL) == -1) {
+				pjdlog_errno(LOG_ERR,
+				    "Unable to limit capability rights to CAP_IOCTL on ggate descriptor");
+			}
+			if (cap_ioctls_limit(res->hr_ggatefd, ggatecmds,
+			    sizeof(ggatecmds) / sizeof(ggatecmds[0])) == -1) {
+				pjdlog_errno(LOG_ERR,
+				    "Unable to limit allowed ggate ioctls");
+			}
+		}
+	}
+#else
+	capsicum = false;
 #endif
-		capsicum = false;
 
 	/*
 	 * Better be sure that everything succeeded.