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nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion
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In struct nfs4_ace remove the member who and replace it with an
anonymous union holding who_uid and who_gid.  Allowing typesafe
storage uids and gids.

Add a helper pace_gt for sorting posix_acl_entries.

In struct posix_user_ace_state to replace uid with a union
of kuid_t uid and kgid_t gid.

Remove all initializations of the deprecated posic_acl_entry
e_id field.  Which is not present when user namespaces are enabled.

Split find_uid into two functions find_uid and find_gid that work
in a typesafe manner.

In nfs4xdr update nfsd4_encode_fattr to deal with the changes
in struct nfs4_ace.

Rewrite nfsd4_encode_name to take a kuid_t and a kgid_t instead
of a generic id and flag if it is a group or a uid.  Replace
the group flag with a test for a valid gid.

Modify nfsd4_encode_user to take a kuid_t and call the modifed
nfsd4_encode_name.

Modify nfsd4_encode_group to take a kgid_t and call the modified
nfsd4_encode_name.

Modify nfsd4_encode_aclname to take an ace instead of taking the
fields of an ace broken out.  This allows it to detect if the ace is
for a user or a group and to pass the appropriate value while still
being typesafe.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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@ebiederm
ebiederm committed Feb 13, 2013
1 parent 7c19723 commit ab8e4ae
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Showing 3 changed files with 76 additions and 34 deletions.
63 changes: 46 additions & 17 deletions fs/nfsd/nfs4acl.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -264,7 +264,7 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
ace->flag = eflag;
ace->access_mask = deny_mask_from_posix(deny, flags);
ace->whotype = NFS4_ACL_WHO_NAMED;
ace->who = pa->e_id;
ace->who_uid = pa->e_uid;
ace++;
acl->naces++;
}
Expand All @@ -273,7 +273,7 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
flags);
ace->whotype = NFS4_ACL_WHO_NAMED;
ace->who = pa->e_id;
ace->who_uid = pa->e_uid;
ace++;
acl->naces++;
pa++;
Expand All @@ -300,7 +300,7 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
flags);
ace->whotype = NFS4_ACL_WHO_NAMED;
ace->who = pa->e_id;
ace->who_gid = pa->e_gid;
ace++;
acl->naces++;
pa++;
Expand Down Expand Up @@ -329,7 +329,7 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
ace->access_mask = deny_mask_from_posix(deny, flags);
ace->whotype = NFS4_ACL_WHO_NAMED;
ace->who = pa->e_id;
ace->who_gid = pa->e_gid;
ace++;
acl->naces++;
}
Expand All @@ -345,6 +345,18 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
acl->naces++;
}

static bool
pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
{
if (pace1->e_tag != pace2->e_tag)
return pace1->e_tag > pace2->e_tag;
if (pace1->e_tag == ACL_USER)
return uid_gt(pace1->e_uid, pace2->e_uid);
if (pace1->e_tag == ACL_GROUP)
return gid_gt(pace1->e_gid, pace2->e_gid);
return false;
}

static void
sort_pacl_range(struct posix_acl *pacl, int start, int end) {
int sorted = 0, i;
Expand All @@ -355,8 +367,8 @@ sort_pacl_range(struct posix_acl *pacl, int start, int end) {
while (!sorted) {
sorted = 1;
for (i = start; i < end; i++) {
if (pacl->a_entries[i].e_id
> pacl->a_entries[i+1].e_id) {
if (pace_gt(&pacl->a_entries[i],
&pacl->a_entries[i+1])) {
sorted = 0;
tmp = pacl->a_entries[i];
pacl->a_entries[i] = pacl->a_entries[i+1];
Expand Down Expand Up @@ -398,7 +410,10 @@ struct posix_ace_state {
};

struct posix_user_ace_state {
uid_t uid;
union {
kuid_t uid;
kgid_t gid;
};
struct posix_ace_state perms;
};

Expand Down Expand Up @@ -521,7 +536,6 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
if (error)
goto out_err;
low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
pace->e_id = ACL_UNDEFINED_ID;

for (i=0; i < state->users->n; i++) {
pace++;
Expand All @@ -531,7 +545,7 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
goto out_err;
low_mode_from_nfs4(state->users->aces[i].perms.allow,
&pace->e_perm, flags);
pace->e_id = state->users->aces[i].uid;
pace->e_uid = state->users->aces[i].uid;
add_to_mask(state, &state->users->aces[i].perms);
}

Expand All @@ -541,7 +555,6 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
if (error)
goto out_err;
low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
pace->e_id = ACL_UNDEFINED_ID;
add_to_mask(state, &state->group);

for (i=0; i < state->groups->n; i++) {
Expand All @@ -552,22 +565,20 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
goto out_err;
low_mode_from_nfs4(state->groups->aces[i].perms.allow,
&pace->e_perm, flags);
pace->e_id = state->groups->aces[i].uid;
pace->e_gid = state->groups->aces[i].gid;
add_to_mask(state, &state->groups->aces[i].perms);
}

pace++;
pace->e_tag = ACL_MASK;
low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
pace->e_id = ACL_UNDEFINED_ID;

pace++;
pace->e_tag = ACL_OTHER;
error = check_deny(state->other.deny, 0);
if (error)
goto out_err;
low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
pace->e_id = ACL_UNDEFINED_ID;

return pacl;
out_err:
Expand All @@ -587,12 +598,13 @@ static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
astate->deny |= mask & ~astate->allow;
}

static int find_uid(struct posix_acl_state *state, struct posix_ace_state_array *a, uid_t uid)
static int find_uid(struct posix_acl_state *state, kuid_t uid)
{
struct posix_ace_state_array *a = state->users;
int i;

for (i = 0; i < a->n; i++)
if (a->aces[i].uid == uid)
if (uid_eq(a->aces[i].uid, uid))
return i;
/* Not found: */
a->n++;
Expand All @@ -603,6 +615,23 @@ static int find_uid(struct posix_acl_state *state, struct posix_ace_state_array
return i;
}

static int find_gid(struct posix_acl_state *state, kgid_t gid)
{
struct posix_ace_state_array *a = state->groups;
int i;

for (i = 0; i < a->n; i++)
if (gid_eq(a->aces[i].gid, gid))
return i;
/* Not found: */
a->n++;
a->aces[i].gid = gid;
a->aces[i].perms.allow = state->everyone.allow;
a->aces[i].perms.deny = state->everyone.deny;

return i;
}

static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
{
int i;
Expand Down Expand Up @@ -636,7 +665,7 @@ static void process_one_v4_ace(struct posix_acl_state *state,
}
break;
case ACL_USER:
i = find_uid(state, state->users, ace->who);
i = find_uid(state, ace->who_uid);
if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
allow_bits(&state->users->aces[i].perms, mask);
} else {
Expand All @@ -658,7 +687,7 @@ static void process_one_v4_ace(struct posix_acl_state *state,
}
break;
case ACL_GROUP:
i = find_uid(state, state->groups, ace->who);
i = find_gid(state, ace->who_gid);
if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
allow_bits(&state->groups->aces[i].perms, mask);
} else {
Expand Down
41 changes: 25 additions & 16 deletions fs/nfsd/nfs4xdr.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -293,13 +293,13 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
ace->whotype = nfs4_acl_get_whotype(buf, dummy32);
status = nfs_ok;
if (ace->whotype != NFS4_ACL_WHO_NAMED)
ace->who = 0;
;
else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
status = nfsd_map_name_to_gid(argp->rqstp,
buf, dummy32, &ace->who);
buf, dummy32, &ace->who_gid);
else
status = nfsd_map_name_to_uid(argp->rqstp,
buf, dummy32, &ace->who);
buf, dummy32, &ace->who_uid);
if (status)
return status;
}
Expand Down Expand Up @@ -1926,7 +1926,7 @@ static u32 nfs4_file_type(umode_t mode)
}

static __be32
nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, kuid_t uid, kgid_t gid,
__be32 **p, int *buflen)
{
int status;
Expand All @@ -1935,10 +1935,10 @@ nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
return nfserr_resource;
if (whotype != NFS4_ACL_WHO_NAMED)
status = nfs4_acl_write_who(whotype, (u8 *)(*p + 1));
else if (group)
status = nfsd_map_gid_to_name(rqstp, id, (u8 *)(*p + 1));
else if (gid_valid(gid))
status = nfsd_map_gid_to_name(rqstp, gid, (u8 *)(*p + 1));
else
status = nfsd_map_uid_to_name(rqstp, id, (u8 *)(*p + 1));
status = nfsd_map_uid_to_name(rqstp, uid, (u8 *)(*p + 1));
if (status < 0)
return nfserrno(status);
*p = xdr_encode_opaque(*p, NULL, status);
Expand All @@ -1948,22 +1948,33 @@ nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
}

static inline __be32
nfsd4_encode_user(struct svc_rqst *rqstp, uid_t uid, __be32 **p, int *buflen)
nfsd4_encode_user(struct svc_rqst *rqstp, kuid_t user, __be32 **p, int *buflen)
{
return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, uid, 0, p, buflen);
return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, user, INVALID_GID,
p, buflen);
}

static inline __be32
nfsd4_encode_group(struct svc_rqst *rqstp, uid_t gid, __be32 **p, int *buflen)
nfsd4_encode_group(struct svc_rqst *rqstp, kgid_t group, __be32 **p, int *buflen)
{
return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, gid, 1, p, buflen);
return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, INVALID_UID, group,
p, buflen);
}

static inline __be32
nfsd4_encode_aclname(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
nfsd4_encode_aclname(struct svc_rqst *rqstp, struct nfs4_ace *ace,
__be32 **p, int *buflen)
{
return nfsd4_encode_name(rqstp, whotype, id, group, p, buflen);
kuid_t uid = INVALID_UID;
kgid_t gid = INVALID_GID;

if (ace->whotype == NFS4_ACL_WHO_NAMED) {
if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
gid = ace->who_gid;
else
uid = ace->who_uid;
}
return nfsd4_encode_name(rqstp, ace->whotype, uid, gid, p, buflen);
}

#define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
Expand Down Expand Up @@ -2224,9 +2235,7 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
WRITE32(ace->type);
WRITE32(ace->flag);
WRITE32(ace->access_mask & NFS4_ACE_MASK_ALL);
status = nfsd4_encode_aclname(rqstp, ace->whotype,
ace->who, ace->flag & NFS4_ACE_IDENTIFIER_GROUP,
&p, &buflen);
status = nfsd4_encode_aclname(rqstp, ace, &p, &buflen);
if (status == nfserr_resource)
goto out_resource;
if (status)
Expand Down
6 changes: 5 additions & 1 deletion include/linux/nfs4.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,14 +13,18 @@
#define _LINUX_NFS4_H

#include <linux/list.h>
#include <linux/uidgid.h>
#include <uapi/linux/nfs4.h>

struct nfs4_ace {
uint32_t type;
uint32_t flag;
uint32_t access_mask;
int whotype;
uid_t who;
union {
kuid_t who_uid;
kgid_t who_gid;
};
};

struct nfs4_acl {
Expand Down

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