PERFORCE change 171326 for review

[Jonathan Anderson]

http://p4web.freebsd.org/chv.cgi?CH=171326

Change 171326 by jona at jona-capsicum-kent64 on 2009/12/03 14:03:05

	Enable fchmodat(2)

Affected files ...

.. //depot/projects/trustedbsd/capabilities/src/sys/kern/capabilities.conf#24 edit
.. //depot/projects/trustedbsd/capabilities/src/sys/kern/init_sysent.c#44 edit
.. //depot/projects/trustedbsd/capabilities/src/sys/kern/vfs_syscalls.c#21 edit

Differences ...

==== //depot/projects/trustedbsd/capabilities/src/sys/kern/capabilities.conf#24 (text+ko) ====

@@ -38,7 +38,7 @@
 ## - sys_exit(2), abort2(2) and close(2) are very important.
 ## - Sorted alphabetically, please keep it that way.
 ##
-## $P4: //depot/projects/trustedbsd/capabilities/src/sys/kern/capabilities.conf#23 $
+## $P4: //depot/projects/trustedbsd/capabilities/src/sys/kern/capabilities.conf#24 $
 ##
 
 ##
@@ -453,10 +453,11 @@
 olio_listio
 
 ##
-## Allow faccessat(2) and openat(2), which we have constrained to prevent accessing
+## Allow some of the *at(2) calls, which we have constrained to prevent accessing
 ## files which are not "under" the directory FD given to the syscall.
 ##
 faccessat
+fchmodat
 openat
 
 ##

==== //depot/projects/trustedbsd/capabilities/src/sys/kern/init_sysent.c#44 (text+ko) ====

@@ -524,7 +524,7 @@
 	{ AS(cpuset_getaffinity_args), (sy_call_t *)cpuset_getaffinity, AUE_NULL, NULL, 0, 0, 0 },	/* 487 = cpuset_getaffinity */
 	{ AS(cpuset_setaffinity_args), (sy_call_t *)cpuset_setaffinity, AUE_NULL, NULL, 0, 0, 0 },	/* 488 = cpuset_setaffinity */
 	{ AS(faccessat_args), (sy_call_t *)faccessat, AUE_FACCESSAT, NULL, 0, 0, SYF_CAPENABLED },	/* 489 = faccessat */
-	{ AS(fchmodat_args), (sy_call_t *)fchmodat, AUE_FCHMODAT, NULL, 0, 0, 0 },	/* 490 = fchmodat */
+	{ AS(fchmodat_args), (sy_call_t *)fchmodat, AUE_FCHMODAT, NULL, 0, 0, SYF_CAPENABLED },	/* 490 = fchmodat */
 	{ AS(fchownat_args), (sy_call_t *)fchownat, AUE_FCHOWNAT, NULL, 0, 0, 0 },	/* 491 = fchownat */
 	{ AS(fexecve_args), (sy_call_t *)fexecve, AUE_FEXECVE, NULL, 0, 0, SYF_CAPENABLED },	/* 492 = fexecve */
 	{ AS(fstatat_args), (sy_call_t *)fstatat, AUE_FSTATAT, NULL, 0, 0, 0 },	/* 493 = fstatat */

==== //depot/projects/trustedbsd/capabilities/src/sys/kern/vfs_syscalls.c#21 (text+ko) ====

@@ -3042,13 +3042,20 @@
 	struct nameidata nd;
 	int vfslocked;
 	int follow;
+	struct vnode *base;
 
 	AUDIT_ARG_MODE(mode);
 	follow = (flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
-	NDINIT_AT(&nd, LOOKUP,  follow | MPSAFE | AUDITVNODE1, pathseg, path,
-	    fd, td);
-	if ((error = namei(&nd)) != 0)
+	if ((error = fgetbase(td, fd, CAP_FCHMOD, &base)))
+		return (error);
+
+	NDINIT_ATBASE(&nd, LOOKUP,  follow | MPSAFE | AUDITVNODE1, pathseg, path,
+	    fd, base, td);
+	error = namei(&nd);
+	if (base) vput(base);
+	if (error)
 		return (error);
+
 	vfslocked = NDHASGIANT(&nd);
 	NDFREE(&nd, NDF_ONLY_PNBUF);
 	error = setfmode(td, nd.ni_vp, mode);