Rework the credential code to support larger values of NGROUPS and

NGROUPS_MAX, eliminate ABI dependencies on them, and raise the to 1024
and 1023 respectively.  (Previously they were equal, but under a close
reading of POSIX, NGROUPS_MAX was defined to be too large by 1 since it
is the number of supplemental groups, not total number of groups.)

The bulk of the change consists of converting the struct ucred member
cr_groups from a static array to a pointer.  Do the equivalent in
kinfo_proc.

Introduce new interfaces crcopysafe() and crsetgroups() for duplicating
a process credential before modifying it and for setting group lists
respectively.  Both interfaces take care for the details of allocating
groups array. crsetgroups() takes care of truncating the group list
to the current maximum (NGROUPS) if necessary.  In the future,
crsetgroups() may be responsible for insuring invariants such as sorting
the supplemental groups to allow groupmember() to be implemented as a
binary search.

Because we can not change struct xucred without breaking application
ABIs, we leave it alone and introduce a new XU_NGROUPS value which is
always 16 and is to be used or NGRPS as appropriate for things such as
NFS which need to use no more than 16 groups.  When feasible, truncate
the group list rather than generating an error.

Minor changes:
  - Reduce the number of hand rolled versions of groupmember().
  - Do not assign to both cr_gid and cr_groups[0].
  - Modify ipfw to cache ucreds instead of part of their contents since
    they are immutable once referenced by more than one entity.

Submitted by:	Isilon Systems (initial implementation)
X-MFC after:	never
PR:		bin/113398 kern/133867

7 files changed, 18 insertions, 31 deletions

diff --git a/sys/fs/nfs/nfs_commonport.c b/sys/fs/nfs/nfs_commonport.c
index 0369113..bf982aa 100644
--- a/sys/fs/nfs/nfs_commonport.c
+++ b/sys/fs/nfs/nfs_commonport.c
@@ -220,14 +220,9 @@ nfsrv_lookupfilename(struct nameidata *ndp, char *fname, NFSPROC_T *p)
 void
 newnfs_copycred(struct nfscred *nfscr, struct ucred *cr)
 {
-	int ngroups, i;
 
 	cr->cr_uid = nfscr->nfsc_uid;
-	ngroups = (nfscr->nfsc_ngroups < NGROUPS) ?
-	    nfscr->nfsc_ngroups : NGROUPS;
-	for (i = 0; i < ngroups; i++)
-		cr->cr_groups[i] = nfscr->nfsc_groups[i];
-	cr->cr_ngroups = ngroups;
+	crsetgroups(cr, nfscr->nfsc_ngroups, nfscr->nfsc_groups);
 }
 
 /*
diff --git a/sys/fs/nfsclient/nfs_clport.c b/sys/fs/nfsclient/nfs_clport.c
index 3b5e367..5b747c7 100644
--- a/sys/fs/nfsclient/nfs_clport.c
+++ b/sys/fs/nfsclient/nfs_clport.c
@@ -976,14 +976,12 @@ nfscl_getmyip(struct nfsmount *nmp, int *isinet6p)
 void
 newnfs_copyincred(struct ucred *cr, struct nfscred *nfscr)
 {
-	int ngroups, i;
+	int i;
 
 	nfscr->nfsc_uid = cr->cr_uid;
-	ngroups = (cr->cr_ngroups > NGROUPS) ? NGROUPS :
-	    cr->cr_ngroups;
-	for (i = 0; i < ngroups; i++)
+	nfscr->nfsc_ngroups = MIN(cr->cr_ngroups, XU_NGROUPS);
+	for (i = 0; i < nfscr->nfsc_ngroups; i++)
 		nfscr->nfsc_groups[i] = cr->cr_groups[i];
-	nfscr->nfsc_ngroups = ngroups;
 }
 
 
diff --git a/sys/fs/nfsserver/nfs_nfsdport.c b/sys/fs/nfsserver/nfs_nfsdport.c
index 730a750..8f5cc94 100644
--- a/sys/fs/nfsserver/nfs_nfsdport.c
+++ b/sys/fs/nfsserver/nfs_nfsdport.c
@@ -2360,7 +2360,6 @@ int
 nfsd_excred(struct nfsrv_descript *nd, struct nfsexstuff *exp,
     struct ucred *credanon)
 {
-	int i;
 	int error = 0;
 
 	/*
@@ -2403,9 +2402,8 @@ nfsd_excred(struct nfsrv_descript *nd, struct nfsexstuff *exp,
 	     (nd->nd_flag & ND_AUTHNONE))) {
 		nd->nd_cred->cr_uid = credanon->cr_uid;
 		nd->nd_cred->cr_gid = credanon->cr_gid;
-		for (i = 0; i < credanon->cr_ngroups && i < NGROUPS; i++)
-			nd->nd_cred->cr_groups[i] = credanon->cr_groups[i];
-		nd->nd_cred->cr_ngroups = i;
+		crsetgroups(nd->nd_cred, credanon->cr_ngroups,
+		    credanon->cr_groups);
 	}
 	return (0);
 }
diff --git a/sys/fs/nfsserver/nfs_nfsdstate.c b/sys/fs/nfsserver/nfs_nfsdstate.c
index 077ce2a..7794278 100644
--- a/sys/fs/nfsserver/nfs_nfsdstate.c
+++ b/sys/fs/nfsserver/nfs_nfsdstate.c
@@ -3577,7 +3577,6 @@ nfsrv_docallback(struct nfsclient *clp, int procnum,
 	nd->nd_repstat = 0;
 	cred->cr_uid = clp->lc_uid;
 	cred->cr_gid = clp->lc_gid;
-	cred->cr_groups[0] = clp->lc_gid;
 	callback = clp->lc_callback;
 	NFSUNLOCKSTATE();
 	cred->cr_ngroups = 1;
diff --git a/sys/fs/portalfs/portal.h b/sys/fs/portalfs/portal.h
index 6606ccc..1fd2d99 100644
--- a/sys/fs/portalfs/portal.h
+++ b/sys/fs/portalfs/portal.h
@@ -43,7 +43,7 @@ struct portal_cred {
 	int		pcr_flag;		/* File open mode */
 	uid_t		pcr_uid;		/* From ucred */
 	short		pcr_ngroups;		/* From ucred */
-	gid_t		pcr_groups[NGROUPS];	/* From ucred */
+	gid_t		pcr_groups[XU_NGROUPS];	/* From ucred */
 };
 
 #ifdef _KERNEL
diff --git a/sys/fs/portalfs/portal_vnops.c b/sys/fs/portalfs/portal_vnops.c
index 8b49ad3..8d30ebb 100644
--- a/sys/fs/portalfs/portal_vnops.c
+++ b/sys/fs/portalfs/portal_vnops.c
@@ -311,8 +311,9 @@ portal_open(ap)
 
 	pcred.pcr_flag = ap->a_mode;
 	pcred.pcr_uid = ap->a_cred->cr_uid;
-	pcred.pcr_ngroups = ap->a_cred->cr_ngroups;
-	bcopy(ap->a_cred->cr_groups, pcred.pcr_groups, NGROUPS * sizeof(gid_t));
+	pcred.pcr_ngroups = MIN(ap->a_cred->cr_ngroups, XU_NGROUPS);
+	bcopy(ap->a_cred->cr_groups, pcred.pcr_groups,
+	    pcred.pcr_ngroups * sizeof(gid_t));
 	aiov[0].iov_base = (caddr_t) &pcred;
 	aiov[0].iov_len = sizeof(pcred);
 	aiov[1].iov_base = pt->pt_arg;
diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c
index 8505cac..11671cb 100644
--- a/sys/fs/unionfs/union_vnops.c
+++ b/sys/fs/unionfs/union_vnops.c
@@ -638,7 +638,6 @@ unionfs_check_corrected_access(accmode_t accmode,
 	uid_t		uid;	/* upper side vnode's uid */
 	gid_t		gid;	/* upper side vnode's gid */
 	u_short		vmode;	/* upper side vnode's mode */
-	gid_t          *gp;
 	u_short		mask;
 
 	mask = 0;
@@ -659,17 +658,14 @@ unionfs_check_corrected_access(accmode_t accmode,
 
 	/* check group */
 	count = 0;
-	gp = cred->cr_groups;
-	for (; count < cred->cr_ngroups; count++, gp++) {
-		if (gid == *gp) {
-			if (accmode & VEXEC)
-				mask |= S_IXGRP;
-			if (accmode & VREAD)
-				mask |= S_IRGRP;
-			if (accmode & VWRITE)
-				mask |= S_IWGRP;
-			return ((vmode & mask) == mask ? 0 : EACCES);
-		}
+	if (groupmember(gid, cred)) {
+		if (accmode & VEXEC)
+			mask |= S_IXGRP;
+		if (accmode & VREAD)
+			mask |= S_IRGRP;
+		if (accmode & VWRITE)
+			mask |= S_IWGRP;
+		return ((vmode & mask) == mask ? 0 : EACCES);
 	}
 
 	/* check other */