From d7c75c7a20590cab729c3d653aaa91a4960d6165 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Wed, 6 May 2009 16:57:44 -0700
Subject: [PATCH] fstest regression fixes - POSIX error codes.

Deal with most of the issues found by FreeBSD's fstest regression test:
    * Limit path components to 255 characters.  Return ENAMETOOLONG if
      the limit is exceeded.

    * Return EEXIST, EINVAL, and ENOTEMPTY as appropriate when the user
      attempts to create, delete, or rename "." or "..", instead of EINVAL.

    * Return EISDIR if an attempt is made to open a directory for writing,
      instead of EINVAL.

    * Return EACCES if an attempt is made to open a file O_TRUNC without
      O_RDWR or O_WRONLY, instead of silently dropping the O_TRUNC.

    * Implement O_NOFOLLOW semantics generally instead of just with O_EXCL.

Not dealt with:
    * DragonFly clears SGID AND SUID on uid or gid change, if not root.
      If root is doing the operation SGID/SUID is not cleared.

    * HAMMER cannot modify the ctime without rolling a new inode, which
      is very expensive, and does not do so when entries are added or
      removed from a directory.  mtime is modified.
---
 sys/kern/vfs_helper.c  |  6 ++++++
 sys/kern/vfs_nlookup.c | 23 ++++++++++++++++++++---
 sys/kern/vfs_vnops.c   | 10 ++++++++--
 3 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/sys/kern/vfs_helper.c b/sys/kern/vfs_helper.c
index 531fd3e28d..1b2f6a53a2 100644
--- a/sys/kern/vfs_helper.c
+++ b/sys/kern/vfs_helper.c
@@ -247,6 +247,12 @@ vop_helper_chown(struct vnode *vp, uid_t new_uid, gid_t new_gid,
 	*cur_uidp = new_uid;
 	*cur_gidp = new_gid;
 	/* XXX QUOTA CODE */
+
+	/*
+	 * DragonFly clears both SUID and SGID if either the owner or
+	 * group is changed and root isn't doing it.  If root is doing
+	 * it we do not clear SUID/SGID.
+	 */
 	if (cred->cr_uid != 0 && (ouid != new_uid || ogid != new_gid))
 		*cur_modep &= ~(S_ISUID | S_ISGID);
 	return(0);
diff --git a/sys/kern/vfs_nlookup.c b/sys/kern/vfs_nlookup.c
index ab783b8333..09758a6c19 100644
--- a/sys/kern/vfs_nlookup.c
+++ b/sys/kern/vfs_nlookup.c
@@ -375,12 +375,17 @@ nlookup(struct nlookupdata *nd)
 	    break;
 
 	/*
-	 * Extract the path component
+	 * Extract the path component.  Path components are limited to
+	 * 255 characters.
 	 */
 	nlc.nlc_nameptr = ptr;
 	while (*ptr && *ptr != '/')
 	    ++ptr;
 	nlc.nlc_namelen = ptr - nlc.nlc_nameptr;
+	if (nlc.nlc_namelen >= 256) {
+	    error = ENAMETOOLONG;
+	    break;
+	}
 
 	/*
 	 * Lookup the path component in the cache, creating an unresolved
@@ -424,7 +429,7 @@ nlookup(struct nlookupdata *nd)
 		KKASSERT(nch.ncp != NULL);
 		cache_get(&nch, &nch);
 	    }
-	    wasdotordotdot = 1;
+	    wasdotordotdot = 2;
 	} else {
 	    nch = cache_nlookup(&nd->nl_nch, &nlc);
 	    while ((error = cache_resolve(&nch, nd->nl_cred)) == EAGAIN) {
@@ -496,7 +501,15 @@ nlookup(struct nlookupdata *nd)
 	    if (error == 0 && wasdotordotdot &&
 		(nd->nl_flags & (NLC_CREATE | NLC_DELETE |
 				 NLC_RENAME_SRC | NLC_RENAME_DST))) {
-		error = EINVAL;
+		/*
+		 * POSIX junk
+		 */
+		if (nd->nl_flags & NLC_CREATE)
+			error = EEXIST;
+		else if (nd->nl_flags & NLC_DELETE)
+			error = (wasdotordotdot == 1) ? EINVAL : ENOTEMPTY;
+		else
+			error = EINVAL;
 	    }
 	}
 
@@ -854,6 +867,9 @@ naccess(struct nchandle *nch, int nflags, struct ucred *cred, int *nflagsp)
 		case VCHR:
 		case VBLK:
 		    break;
+		case VDIR:
+		    error = EISDIR;
+		    break;
 		default:
 		    error = EINVAL;
 		    break;
@@ -943,6 +959,7 @@ naccess_va(struct vattr *va, int nflags, struct ucred *cred)
 	if (nflags & (NLC_WRITE | NLC_TRUNCATE)) {
 	    switch(va->va_type) {
 	    case VDIR:
+		return (EISDIR);
 	    case VLNK:
 	    case VREG:
 	    case VDATABASE:
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 4bdf93396f..89c30f8962 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -133,6 +133,12 @@ vn_open(struct nlookupdata *nd, struct file *fp, int fmode, int cmode)
 	struct vattr *vap = &vat;
 	int error;
 
+	/*
+	 * Certain combinations are illegal
+	 */
+	if ((fmode & (FWRITE | O_TRUNC)) == O_TRUNC)
+		return(EACCES);
+
 	/*
 	 * Lookup the path and create or obtain the vnode.  After a
 	 * successful lookup a locked nd->nl_nch will be returned.
@@ -151,6 +157,8 @@ vn_open(struct nlookupdata *nd, struct file *fp, int fmode, int cmode)
 		nd->nl_flags |= NLC_READ;
 	if (fmode & FWRITE)
 		nd->nl_flags |= NLC_WRITE;
+	if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
+		nd->nl_flags |= NLC_FOLLOW;
 
 	if (fmode & O_CREAT) {
 		/*
@@ -163,8 +171,6 @@ vn_open(struct nlookupdata *nd, struct file *fp, int fmode, int cmode)
 		 * write permission on the governing directory or EPERM
 		 * is returned.
 		 */
-		if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
-			nd->nl_flags |= NLC_FOLLOW;
 		nd->nl_flags |= NLC_CREATE;
 		nd->nl_flags |= NLC_REFDVP;
 		bwillinode(1);
-- 
2.41.0