diff options
Diffstat (limited to 'fs/nfsd/nfs4acl.c')
| -rw-r--r-- | fs/nfsd/nfs4acl.c | 877 |
1 files changed, 877 insertions, 0 deletions
diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c new file mode 100644 index 0000000000..96e786b5e5 --- /dev/null +++ b/fs/nfsd/nfs4acl.c @@ -0,0 +1,877 @@ +/* + * Common NFSv4 ACL handling code. + * + * Copyright (c) 2002, 2003 The Regents of the University of Michigan. + * All rights reserved. + * + * Marius Aamodt Eriksen <marius@umich.edu> + * Jeff Sedlak <jsedlak@umich.edu> + * J. Bruce Fields <bfields@umich.edu> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/posix_acl.h> + +#include "nfsfh.h" +#include "nfsd.h" +#include "acl.h" +#include "vfs.h" + +#define NFS4_ACL_TYPE_DEFAULT 0x01 +#define NFS4_ACL_DIR 0x02 +#define NFS4_ACL_OWNER 0x04 + +/* mode bit translations: */ +#define NFS4_READ_MODE (NFS4_ACE_READ_DATA) +#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA) +#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE +#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE) +#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL) + +/* flags used to simulate posix default ACLs */ +#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \ + | NFS4_ACE_DIRECTORY_INHERIT_ACE) + +#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \ + | NFS4_ACE_INHERIT_ONLY_ACE \ + | NFS4_ACE_IDENTIFIER_GROUP) + +static u32 +mask_from_posix(unsigned short perm, unsigned int flags) +{ + int mask = NFS4_ANYONE_MODE; + + if (flags & NFS4_ACL_OWNER) + mask |= NFS4_OWNER_MODE; + if (perm & ACL_READ) + mask |= NFS4_READ_MODE; + if (perm & ACL_WRITE) + mask |= NFS4_WRITE_MODE; + if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) + mask |= NFS4_ACE_DELETE_CHILD; + if (perm & ACL_EXECUTE) + mask |= NFS4_EXECUTE_MODE; + return mask; +} + +static u32 +deny_mask_from_posix(unsigned short perm, u32 flags) +{ + u32 mask = 0; + + if (perm & ACL_READ) + mask |= NFS4_READ_MODE; + if (perm & ACL_WRITE) + mask |= NFS4_WRITE_MODE; + if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR)) + mask |= NFS4_ACE_DELETE_CHILD; + if (perm & ACL_EXECUTE) + mask |= NFS4_EXECUTE_MODE; + return mask; +} + +/* XXX: modify functions to return NFS errors; they're only ever + * used by nfs code, after all.... */ + +/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the + * side of being more restrictive, so the mode bit mapping below is + * pessimistic. An optimistic version would be needed to handle DENY's, + * but we expect to coalesce all ALLOWs and DENYs before mapping to mode + * bits. */ + +static void +low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags) +{ + u32 write_mode = NFS4_WRITE_MODE; + + if (flags & NFS4_ACL_DIR) + write_mode |= NFS4_ACE_DELETE_CHILD; + *mode = 0; + if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE) + *mode |= ACL_READ; + if ((perm & write_mode) == write_mode) + *mode |= ACL_WRITE; + if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE) + *mode |= ACL_EXECUTE; +} + +static short ace2type(struct nfs4_ace *); +static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *, + unsigned int); + +int +nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, + struct nfs4_acl **acl) +{ + struct inode *inode = d_inode(dentry); + int error = 0; + struct posix_acl *pacl = NULL, *dpacl = NULL; + unsigned int flags = 0; + int size = 0; + + pacl = get_inode_acl(inode, ACL_TYPE_ACCESS); + if (!pacl) + pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); + + if (IS_ERR(pacl)) + return PTR_ERR(pacl); + + /* allocate for worst case: one (deny, allow) pair each: */ + size += 2 * pacl->a_count; + + if (S_ISDIR(inode->i_mode)) { + flags = NFS4_ACL_DIR; + dpacl = get_inode_acl(inode, ACL_TYPE_DEFAULT); + if (IS_ERR(dpacl)) { + error = PTR_ERR(dpacl); + goto rel_pacl; + } + + if (dpacl) + size += 2 * dpacl->a_count; + } + + *acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL); + if (*acl == NULL) { + error = -ENOMEM; + goto out; + } + (*acl)->naces = 0; + + _posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT); + + if (dpacl) + _posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT); + +out: + posix_acl_release(dpacl); +rel_pacl: + posix_acl_release(pacl); + return error; +} + +struct posix_acl_summary { + unsigned short owner; + unsigned short users; + unsigned short group; + unsigned short groups; + unsigned short other; + unsigned short mask; +}; + +static void +summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas) +{ + struct posix_acl_entry *pa, *pe; + + /* + * Only pas.users and pas.groups need initialization; previous + * posix_acl_valid() calls ensure that the other fields will be + * initialized in the following loop. But, just to placate gcc: + */ + memset(pas, 0, sizeof(*pas)); + pas->mask = 07; + + pe = acl->a_entries + acl->a_count; + + FOREACH_ACL_ENTRY(pa, acl, pe) { + switch (pa->e_tag) { + case ACL_USER_OBJ: + pas->owner = pa->e_perm; + break; + case ACL_GROUP_OBJ: + pas->group = pa->e_perm; + break; + case ACL_USER: + pas->users |= pa->e_perm; + break; + case ACL_GROUP: + pas->groups |= pa->e_perm; + break; + case ACL_OTHER: + pas->other = pa->e_perm; + break; + case ACL_MASK: + pas->mask = pa->e_perm; + break; + } + } + /* We'll only care about effective permissions: */ + pas->users &= pas->mask; + pas->group &= pas->mask; + pas->groups &= pas->mask; +} + +/* We assume the acl has been verified with posix_acl_valid. */ +static void +_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl, + unsigned int flags) +{ + struct posix_acl_entry *pa, *group_owner_entry; + struct nfs4_ace *ace; + struct posix_acl_summary pas; + unsigned short deny; + int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ? + NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0); + + BUG_ON(pacl->a_count < 3); + summarize_posix_acl(pacl, &pas); + + pa = pacl->a_entries; + ace = acl->aces + acl->naces; + + /* We could deny everything not granted by the owner: */ + deny = ~pas.owner; + /* + * but it is equivalent (and simpler) to deny only what is not + * granted by later entries: + */ + deny &= pas.users | pas.group | pas.groups | pas.other; + if (deny) { + ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; + ace->flag = eflag; + ace->access_mask = deny_mask_from_posix(deny, flags); + ace->whotype = NFS4_ACL_WHO_OWNER; + ace++; + acl->naces++; + } + + ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; + ace->flag = eflag; + ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER); + ace->whotype = NFS4_ACL_WHO_OWNER; + ace++; + acl->naces++; + pa++; + + while (pa->e_tag == ACL_USER) { + deny = ~(pa->e_perm & pas.mask); + deny &= pas.groups | pas.group | pas.other; + if (deny) { + ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; + ace->flag = eflag; + ace->access_mask = deny_mask_from_posix(deny, flags); + ace->whotype = NFS4_ACL_WHO_NAMED; + ace->who_uid = pa->e_uid; + ace++; + acl->naces++; + } + ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; + ace->flag = eflag; + ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, + flags); + ace->whotype = NFS4_ACL_WHO_NAMED; + ace->who_uid = pa->e_uid; + ace++; + acl->naces++; + pa++; + } + + /* In the case of groups, we apply allow ACEs first, then deny ACEs, + * since a user can be in more than one group. */ + + /* allow ACEs */ + + group_owner_entry = pa; + + ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; + ace->flag = eflag; + ace->access_mask = mask_from_posix(pas.group, flags); + ace->whotype = NFS4_ACL_WHO_GROUP; + ace++; + acl->naces++; + pa++; + + while (pa->e_tag == ACL_GROUP) { + ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; + ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; + ace->access_mask = mask_from_posix(pa->e_perm & pas.mask, + flags); + ace->whotype = NFS4_ACL_WHO_NAMED; + ace->who_gid = pa->e_gid; + ace++; + acl->naces++; + pa++; + } + + /* deny ACEs */ + + pa = group_owner_entry; + + deny = ~pas.group & pas.other; + if (deny) { + ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; + ace->flag = eflag; + ace->access_mask = deny_mask_from_posix(deny, flags); + ace->whotype = NFS4_ACL_WHO_GROUP; + ace++; + acl->naces++; + } + pa++; + + while (pa->e_tag == ACL_GROUP) { + deny = ~(pa->e_perm & pas.mask); + deny &= pas.other; + if (deny) { + ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE; + ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP; + ace->access_mask = deny_mask_from_posix(deny, flags); + ace->whotype = NFS4_ACL_WHO_NAMED; + ace->who_gid = pa->e_gid; + ace++; + acl->naces++; + } + pa++; + } + + if (pa->e_tag == ACL_MASK) + pa++; + ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE; + ace->flag = eflag; + ace->access_mask = mask_from_posix(pa->e_perm, flags); + ace->whotype = NFS4_ACL_WHO_EVERYONE; + 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; + + /* We just do a bubble sort; easy to do in place, and we're not + * expecting acl's to be long enough to justify anything more. */ + while (!sorted) { + sorted = 1; + for (i = start; i < end; i++) { + if (pace_gt(&pacl->a_entries[i], + &pacl->a_entries[i+1])) { + sorted = 0; + swap(pacl->a_entries[i], + pacl->a_entries[i + 1]); + } + } + } +} + +static void +sort_pacl(struct posix_acl *pacl) +{ + /* posix_acl_valid requires that users and groups be in order + * by uid/gid. */ + int i, j; + + /* no users or groups */ + if (!pacl || pacl->a_count <= 4) + return; + + i = 1; + while (pacl->a_entries[i].e_tag == ACL_USER) + i++; + sort_pacl_range(pacl, 1, i-1); + + BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ); + j = ++i; + while (pacl->a_entries[j].e_tag == ACL_GROUP) + j++; + sort_pacl_range(pacl, i, j-1); + return; +} + +/* + * While processing the NFSv4 ACE, this maintains bitmasks representing + * which permission bits have been allowed and which denied to a given + * entity: */ +struct posix_ace_state { + u32 allow; + u32 deny; +}; + +struct posix_user_ace_state { + union { + kuid_t uid; + kgid_t gid; + }; + struct posix_ace_state perms; +}; + +struct posix_ace_state_array { + int n; + struct posix_user_ace_state aces[]; +}; + +/* + * While processing the NFSv4 ACE, this maintains the partial permissions + * calculated so far: */ + +struct posix_acl_state { + unsigned char valid; + struct posix_ace_state owner; + struct posix_ace_state group; + struct posix_ace_state other; + struct posix_ace_state everyone; + struct posix_ace_state mask; /* Deny unused in this case */ + struct posix_ace_state_array *users; + struct posix_ace_state_array *groups; +}; + +static int +init_state(struct posix_acl_state *state, int cnt) +{ + int alloc; + + memset(state, 0, sizeof(struct posix_acl_state)); + /* + * In the worst case, each individual acl could be for a distinct + * named user or group, but we don't know which, so we allocate + * enough space for either: + */ + alloc = sizeof(struct posix_ace_state_array) + + cnt*sizeof(struct posix_user_ace_state); + state->users = kzalloc(alloc, GFP_KERNEL); + if (!state->users) + return -ENOMEM; + state->groups = kzalloc(alloc, GFP_KERNEL); + if (!state->groups) { + kfree(state->users); + return -ENOMEM; + } + return 0; +} + +static void +free_state(struct posix_acl_state *state) { + kfree(state->users); + kfree(state->groups); +} + +static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate) +{ + state->mask.allow |= astate->allow; +} + +static struct posix_acl * +posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) +{ + struct posix_acl_entry *pace; + struct posix_acl *pacl; + int nace; + int i; + + /* + * ACLs with no ACEs are treated differently in the inheritable + * and effective cases: when there are no inheritable ACEs, + * calls ->set_acl with a NULL ACL structure. + */ + if (!state->valid && (flags & NFS4_ACL_TYPE_DEFAULT)) + return NULL; + + /* + * When there are no effective ACEs, the following will end + * up setting a 3-element effective posix ACL with all + * permissions zero. + */ + if (!state->users->n && !state->groups->n) + nace = 3; + else /* Note we also include a MASK ACE in this case: */ + nace = 4 + state->users->n + state->groups->n; + pacl = posix_acl_alloc(nace, GFP_KERNEL); + if (!pacl) + return ERR_PTR(-ENOMEM); + + pace = pacl->a_entries; + pace->e_tag = ACL_USER_OBJ; + low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags); + + for (i=0; i < state->users->n; i++) { + pace++; + pace->e_tag = ACL_USER; + low_mode_from_nfs4(state->users->aces[i].perms.allow, + &pace->e_perm, flags); + pace->e_uid = state->users->aces[i].uid; + add_to_mask(state, &state->users->aces[i].perms); + } + + pace++; + pace->e_tag = ACL_GROUP_OBJ; + low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags); + add_to_mask(state, &state->group); + + for (i=0; i < state->groups->n; i++) { + pace++; + pace->e_tag = ACL_GROUP; + low_mode_from_nfs4(state->groups->aces[i].perms.allow, + &pace->e_perm, flags); + pace->e_gid = state->groups->aces[i].gid; + add_to_mask(state, &state->groups->aces[i].perms); + } + + if (state->users->n || state->groups->n) { + pace++; + pace->e_tag = ACL_MASK; + low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags); + } + + pace++; + pace->e_tag = ACL_OTHER; + low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags); + + return pacl; +} + +static inline void allow_bits(struct posix_ace_state *astate, u32 mask) +{ + /* Allow all bits in the mask not already denied: */ + astate->allow |= mask & ~astate->deny; +} + +static inline void deny_bits(struct posix_ace_state *astate, u32 mask) +{ + /* Deny all bits in the mask not already allowed: */ + astate->deny |= mask & ~astate->allow; +} + +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 (uid_eq(a->aces[i].uid, uid)) + return i; + /* Not found: */ + a->n++; + a->aces[i].uid = uid; + a->aces[i].perms.allow = state->everyone.allow; + a->aces[i].perms.deny = state->everyone.deny; + + 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; + + for (i=0; i < a->n; i++) + deny_bits(&a->aces[i].perms, mask); +} + +static void allow_bits_array(struct posix_ace_state_array *a, u32 mask) +{ + int i; + + for (i=0; i < a->n; i++) + allow_bits(&a->aces[i].perms, mask); +} + +static void process_one_v4_ace(struct posix_acl_state *state, + struct nfs4_ace *ace) +{ + u32 mask = ace->access_mask; + short type = ace2type(ace); + int i; + + state->valid |= type; + + switch (type) { + case ACL_USER_OBJ: + if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { + allow_bits(&state->owner, mask); + } else { + deny_bits(&state->owner, mask); + } + break; + case ACL_USER: + 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 { + deny_bits(&state->users->aces[i].perms, mask); + mask = state->users->aces[i].perms.deny; + deny_bits(&state->owner, mask); + } + break; + case ACL_GROUP_OBJ: + if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { + allow_bits(&state->group, mask); + } else { + deny_bits(&state->group, mask); + mask = state->group.deny; + deny_bits(&state->owner, mask); + deny_bits(&state->everyone, mask); + deny_bits_array(state->users, mask); + deny_bits_array(state->groups, mask); + } + break; + case ACL_GROUP: + 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 { + deny_bits(&state->groups->aces[i].perms, mask); + mask = state->groups->aces[i].perms.deny; + deny_bits(&state->owner, mask); + deny_bits(&state->group, mask); + deny_bits(&state->everyone, mask); + deny_bits_array(state->users, mask); + deny_bits_array(state->groups, mask); + } + break; + case ACL_OTHER: + if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) { + allow_bits(&state->owner, mask); + allow_bits(&state->group, mask); + allow_bits(&state->other, mask); + allow_bits(&state->everyone, mask); + allow_bits_array(state->users, mask); + allow_bits_array(state->groups, mask); + } else { + deny_bits(&state->owner, mask); + deny_bits(&state->group, mask); + deny_bits(&state->other, mask); + deny_bits(&state->everyone, mask); + deny_bits_array(state->users, mask); + deny_bits_array(state->groups, mask); + } + } +} + +static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, + struct posix_acl **pacl, struct posix_acl **dpacl, + unsigned int flags) +{ + struct posix_acl_state effective_acl_state, default_acl_state; + struct nfs4_ace *ace; + int ret; + + ret = init_state(&effective_acl_state, acl->naces); + if (ret) + return ret; + ret = init_state(&default_acl_state, acl->naces); + if (ret) + goto out_estate; + ret = -EINVAL; + for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) { + if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE && + ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE) + goto out_dstate; + if (ace->flag & ~NFS4_SUPPORTED_FLAGS) + goto out_dstate; + if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) { + process_one_v4_ace(&effective_acl_state, ace); + continue; + } + if (!(flags & NFS4_ACL_DIR)) + goto out_dstate; + /* + * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT + * is set, we're effectively turning on the other. That's OK, + * according to rfc 3530. + */ + process_one_v4_ace(&default_acl_state, ace); + + if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) + process_one_v4_ace(&effective_acl_state, ace); + } + + /* + * At this point, the default ACL may have zeroed-out entries for owner, + * group and other. That usually results in a non-sensical resulting ACL + * that denies all access except to any ACE that was explicitly added. + * + * The setfacl command solves a similar problem with this logic: + * + * "If a Default ACL entry is created, and the Default ACL contains + * no owner, owning group, or others entry, a copy of the ACL + * owner, owning group, or others entry is added to the Default ACL." + * + * Copy any missing ACEs from the effective set, if any ACEs were + * explicitly set. + */ + if (default_acl_state.valid) { + if (!(default_acl_state.valid & ACL_USER_OBJ)) + default_acl_state.owner = effective_acl_state.owner; + if (!(default_acl_state.valid & ACL_GROUP_OBJ)) + default_acl_state.group = effective_acl_state.group; + if (!(default_acl_state.valid & ACL_OTHER)) + default_acl_state.other = effective_acl_state.other; + } + + *pacl = posix_state_to_acl(&effective_acl_state, flags); + if (IS_ERR(*pacl)) { + ret = PTR_ERR(*pacl); + *pacl = NULL; + goto out_dstate; + } + *dpacl = posix_state_to_acl(&default_acl_state, + flags | NFS4_ACL_TYPE_DEFAULT); + if (IS_ERR(*dpacl)) { + ret = PTR_ERR(*dpacl); + *dpacl = NULL; + posix_acl_release(*pacl); + *pacl = NULL; + goto out_dstate; + } + sort_pacl(*pacl); + sort_pacl(*dpacl); + ret = 0; +out_dstate: + free_state(&default_acl_state); +out_estate: + free_state(&effective_acl_state); + return ret; +} + +__be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl, + struct nfsd_attrs *attr) +{ + int host_error; + unsigned int flags = 0; + + if (!acl) + return nfs_ok; + + if (type == NF4DIR) + flags = NFS4_ACL_DIR; + + host_error = nfs4_acl_nfsv4_to_posix(acl, &attr->na_pacl, + &attr->na_dpacl, flags); + if (host_error == -EINVAL) + return nfserr_attrnotsupp; + else + return nfserrno(host_error); +} + +static short +ace2type(struct nfs4_ace *ace) +{ + switch (ace->whotype) { + case NFS4_ACL_WHO_NAMED: + return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ? + ACL_GROUP : ACL_USER); + case NFS4_ACL_WHO_OWNER: + return ACL_USER_OBJ; + case NFS4_ACL_WHO_GROUP: + return ACL_GROUP_OBJ; + case NFS4_ACL_WHO_EVERYONE: + return ACL_OTHER; + } + BUG(); + return -1; +} + +/* + * return the size of the struct nfs4_acl required to represent an acl + * with @entries entries. + */ +int nfs4_acl_bytes(int entries) +{ + return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace); +} + +static struct { + char *string; + int stringlen; + int type; +} s2t_map[] = { + { + .string = "OWNER@", + .stringlen = sizeof("OWNER@") - 1, + .type = NFS4_ACL_WHO_OWNER, + }, + { + .string = "GROUP@", + .stringlen = sizeof("GROUP@") - 1, + .type = NFS4_ACL_WHO_GROUP, + }, + { + .string = "EVERYONE@", + .stringlen = sizeof("EVERYONE@") - 1, + .type = NFS4_ACL_WHO_EVERYONE, + }, +}; + +int +nfs4_acl_get_whotype(char *p, u32 len) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { + if (s2t_map[i].stringlen == len && + 0 == memcmp(s2t_map[i].string, p, len)) + return s2t_map[i].type; + } + return NFS4_ACL_WHO_NAMED; +} + +__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who) +{ + __be32 *p; + int i; + + for (i = 0; i < ARRAY_SIZE(s2t_map); i++) { + if (s2t_map[i].type != who) + continue; + p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4); + if (!p) + return nfserr_resource; + p = xdr_encode_opaque(p, s2t_map[i].string, + s2t_map[i].stringlen); + return 0; + } + WARN_ON_ONCE(1); + return nfserr_serverfault; +} |