diff options
Diffstat (limited to 'fs/cifs/cifsacl.c')
| -rw-r--r-- | fs/cifs/cifsacl.c | 1354 |
1 files changed, 1354 insertions, 0 deletions
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c new file mode 100644 index 00000000..3cc1b251 --- /dev/null +++ b/fs/cifs/cifsacl.c @@ -0,0 +1,1354 @@ +/* + * fs/cifs/cifsacl.c + * + * Copyright (C) International Business Machines Corp., 2007,2008 + * Author(s): Steve French (sfrench@us.ibm.com) + * + * Contains the routines for mapping CIFS/NTFS ACLs + * + * This library is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published + * by the Free Software Foundation; either version 2.1 of the License, or + * (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/keyctl.h> +#include <linux/key-type.h> +#include <keys/user-type.h> +#include "cifspdu.h" +#include "cifsglob.h" +#include "cifsacl.h" +#include "cifsproto.h" +#include "cifs_debug.h" + +/* security id for everyone/world system group */ +static const struct cifs_sid sid_everyone = { + 1, 1, {0, 0, 0, 0, 0, 1}, {0} }; +/* security id for Authenticated Users system group */ +static const struct cifs_sid sid_authusers = { + 1, 1, {0, 0, 0, 0, 0, 5}, {__constant_cpu_to_le32(11)} }; +/* group users */ +static const struct cifs_sid sid_user = {1, 2 , {0, 0, 0, 0, 0, 5}, {} }; + +const struct cred *root_cred; + +static void +shrink_idmap_tree(struct rb_root *root, int nr_to_scan, int *nr_rem, + int *nr_del) +{ + struct rb_node *node; + struct rb_node *tmp; + struct cifs_sid_id *psidid; + + node = rb_first(root); + while (node) { + tmp = node; + node = rb_next(tmp); + psidid = rb_entry(tmp, struct cifs_sid_id, rbnode); + if (nr_to_scan == 0 || *nr_del == nr_to_scan) + ++(*nr_rem); + else { + if (time_after(jiffies, psidid->time + SID_MAP_EXPIRE) + && psidid->refcount == 0) { + rb_erase(tmp, root); + ++(*nr_del); + } else + ++(*nr_rem); + } + } +} + +/* + * Run idmap cache shrinker. + */ +static int +cifs_idmap_shrinker(struct shrinker *shrink, struct shrink_control *sc) +{ + int nr_to_scan = sc->nr_to_scan; + int nr_del = 0; + int nr_rem = 0; + struct rb_root *root; + + root = &uidtree; + spin_lock(&siduidlock); + shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del); + spin_unlock(&siduidlock); + + root = &gidtree; + spin_lock(&sidgidlock); + shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del); + spin_unlock(&sidgidlock); + + root = &siduidtree; + spin_lock(&uidsidlock); + shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del); + spin_unlock(&uidsidlock); + + root = &sidgidtree; + spin_lock(&gidsidlock); + shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del); + spin_unlock(&gidsidlock); + + return nr_rem; +} + +static void +sid_rb_insert(struct rb_root *root, unsigned long cid, + struct cifs_sid_id **psidid, char *typestr) +{ + char *strptr; + struct rb_node *node = root->rb_node; + struct rb_node *parent = NULL; + struct rb_node **linkto = &(root->rb_node); + struct cifs_sid_id *lsidid; + + while (node) { + lsidid = rb_entry(node, struct cifs_sid_id, rbnode); + parent = node; + if (cid > lsidid->id) { + linkto = &(node->rb_left); + node = node->rb_left; + } + if (cid < lsidid->id) { + linkto = &(node->rb_right); + node = node->rb_right; + } + } + + (*psidid)->id = cid; + (*psidid)->time = jiffies - (SID_MAP_RETRY + 1); + (*psidid)->refcount = 0; + + sprintf((*psidid)->sidstr, "%s", typestr); + strptr = (*psidid)->sidstr + strlen((*psidid)->sidstr); + sprintf(strptr, "%ld", cid); + + clear_bit(SID_ID_PENDING, &(*psidid)->state); + clear_bit(SID_ID_MAPPED, &(*psidid)->state); + + rb_link_node(&(*psidid)->rbnode, parent, linkto); + rb_insert_color(&(*psidid)->rbnode, root); +} + +static struct cifs_sid_id * +sid_rb_search(struct rb_root *root, unsigned long cid) +{ + struct rb_node *node = root->rb_node; + struct cifs_sid_id *lsidid; + + while (node) { + lsidid = rb_entry(node, struct cifs_sid_id, rbnode); + if (cid > lsidid->id) + node = node->rb_left; + else if (cid < lsidid->id) + node = node->rb_right; + else /* node found */ + return lsidid; + } + + return NULL; +} + +static struct shrinker cifs_shrinker = { + .shrink = cifs_idmap_shrinker, + .seeks = DEFAULT_SEEKS, +}; + +static int +cifs_idmap_key_instantiate(struct key *key, const void *data, size_t datalen) +{ + char *payload; + + payload = kmalloc(datalen, GFP_KERNEL); + if (!payload) + return -ENOMEM; + + memcpy(payload, data, datalen); + key->payload.data = payload; + key->datalen = datalen; + return 0; +} + +static inline void +cifs_idmap_key_destroy(struct key *key) +{ + kfree(key->payload.data); +} + +struct key_type cifs_idmap_key_type = { + .name = "cifs.idmap", + .instantiate = cifs_idmap_key_instantiate, + .destroy = cifs_idmap_key_destroy, + .describe = user_describe, + .match = user_match, +}; + +static void +sid_to_str(struct cifs_sid *sidptr, char *sidstr) +{ + int i; + unsigned long saval; + char *strptr; + + strptr = sidstr; + + sprintf(strptr, "%s", "S"); + strptr = sidstr + strlen(sidstr); + + sprintf(strptr, "-%d", sidptr->revision); + strptr = sidstr + strlen(sidstr); + + for (i = 0; i < 6; ++i) { + if (sidptr->authority[i]) { + sprintf(strptr, "-%d", sidptr->authority[i]); + strptr = sidstr + strlen(sidstr); + } + } + + for (i = 0; i < sidptr->num_subauth; ++i) { + saval = le32_to_cpu(sidptr->sub_auth[i]); + sprintf(strptr, "-%ld", saval); + strptr = sidstr + strlen(sidstr); + } +} + +static void +id_rb_insert(struct rb_root *root, struct cifs_sid *sidptr, + struct cifs_sid_id **psidid, char *typestr) +{ + int rc; + char *strptr; + struct rb_node *node = root->rb_node; + struct rb_node *parent = NULL; + struct rb_node **linkto = &(root->rb_node); + struct cifs_sid_id *lsidid; + + while (node) { + lsidid = rb_entry(node, struct cifs_sid_id, rbnode); + parent = node; + rc = compare_sids(sidptr, &((lsidid)->sid)); + if (rc > 0) { + linkto = &(node->rb_left); + node = node->rb_left; + } else if (rc < 0) { + linkto = &(node->rb_right); + node = node->rb_right; + } + } + + memcpy(&(*psidid)->sid, sidptr, sizeof(struct cifs_sid)); + (*psidid)->time = jiffies - (SID_MAP_RETRY + 1); + (*psidid)->refcount = 0; + + sprintf((*psidid)->sidstr, "%s", typestr); + strptr = (*psidid)->sidstr + strlen((*psidid)->sidstr); + sid_to_str(&(*psidid)->sid, strptr); + + clear_bit(SID_ID_PENDING, &(*psidid)->state); + clear_bit(SID_ID_MAPPED, &(*psidid)->state); + + rb_link_node(&(*psidid)->rbnode, parent, linkto); + rb_insert_color(&(*psidid)->rbnode, root); +} + +static struct cifs_sid_id * +id_rb_search(struct rb_root *root, struct cifs_sid *sidptr) +{ + int rc; + struct rb_node *node = root->rb_node; + struct cifs_sid_id *lsidid; + + while (node) { + lsidid = rb_entry(node, struct cifs_sid_id, rbnode); + rc = compare_sids(sidptr, &((lsidid)->sid)); + if (rc > 0) { + node = node->rb_left; + } else if (rc < 0) { + node = node->rb_right; + } else /* node found */ + return lsidid; + } + + return NULL; +} + +static int +sidid_pending_wait(void *unused) +{ + schedule(); + return signal_pending(current) ? -ERESTARTSYS : 0; +} + +static int +id_to_sid(unsigned long cid, uint sidtype, struct cifs_sid *ssid) +{ + int rc = 0; + struct key *sidkey; + const struct cred *saved_cred; + struct cifs_sid *lsid; + struct cifs_sid_id *psidid, *npsidid; + struct rb_root *cidtree; + spinlock_t *cidlock; + + if (sidtype == SIDOWNER) { + cidlock = &siduidlock; + cidtree = &uidtree; + } else if (sidtype == SIDGROUP) { + cidlock = &sidgidlock; + cidtree = &gidtree; + } else + return -EINVAL; + + spin_lock(cidlock); + psidid = sid_rb_search(cidtree, cid); + + if (!psidid) { /* node does not exist, allocate one & attempt adding */ + spin_unlock(cidlock); + npsidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL); + if (!npsidid) + return -ENOMEM; + + npsidid->sidstr = kmalloc(SIDLEN, GFP_KERNEL); + if (!npsidid->sidstr) { + kfree(npsidid); + return -ENOMEM; + } + + spin_lock(cidlock); + psidid = sid_rb_search(cidtree, cid); + if (psidid) { /* node happened to get inserted meanwhile */ + ++psidid->refcount; + spin_unlock(cidlock); + kfree(npsidid->sidstr); + kfree(npsidid); + } else { + psidid = npsidid; + sid_rb_insert(cidtree, cid, &psidid, + sidtype == SIDOWNER ? "oi:" : "gi:"); + ++psidid->refcount; + spin_unlock(cidlock); + } + } else { + ++psidid->refcount; + spin_unlock(cidlock); + } + + /* + * If we are here, it is safe to access psidid and its fields + * since a reference was taken earlier while holding the spinlock. + * A reference on the node is put without holding the spinlock + * and it is OK to do so in this case, shrinker will not erase + * this node until all references are put and we do not access + * any fields of the node after a reference is put . + */ + if (test_bit(SID_ID_MAPPED, &psidid->state)) { + memcpy(ssid, &psidid->sid, sizeof(struct cifs_sid)); + psidid->time = jiffies; /* update ts for accessing */ + goto id_sid_out; + } + + if (time_after(psidid->time + SID_MAP_RETRY, jiffies)) { + rc = -EINVAL; + goto id_sid_out; + } + + if (!test_and_set_bit(SID_ID_PENDING, &psidid->state)) { + saved_cred = override_creds(root_cred); + sidkey = request_key(&cifs_idmap_key_type, psidid->sidstr, ""); + if (IS_ERR(sidkey)) { + rc = -EINVAL; + cFYI(1, "%s: Can't map and id to a SID", __func__); + } else { + lsid = (struct cifs_sid *)sidkey->payload.data; + memcpy(&psidid->sid, lsid, + sidkey->datalen < sizeof(struct cifs_sid) ? + sidkey->datalen : sizeof(struct cifs_sid)); + memcpy(ssid, &psidid->sid, + sidkey->datalen < sizeof(struct cifs_sid) ? + sidkey->datalen : sizeof(struct cifs_sid)); + set_bit(SID_ID_MAPPED, &psidid->state); + key_put(sidkey); + kfree(psidid->sidstr); + } + psidid->time = jiffies; /* update ts for accessing */ + revert_creds(saved_cred); + clear_bit(SID_ID_PENDING, &psidid->state); + wake_up_bit(&psidid->state, SID_ID_PENDING); + } else { + rc = wait_on_bit(&psidid->state, SID_ID_PENDING, + sidid_pending_wait, TASK_INTERRUPTIBLE); + if (rc) { + cFYI(1, "%s: sidid_pending_wait interrupted %d", + __func__, rc); + --psidid->refcount; + return rc; + } + if (test_bit(SID_ID_MAPPED, &psidid->state)) + memcpy(ssid, &psidid->sid, sizeof(struct cifs_sid)); + else + rc = -EINVAL; + } +id_sid_out: + --psidid->refcount; + return rc; +} + +static int +sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid, + struct cifs_fattr *fattr, uint sidtype) +{ + int rc; + unsigned long cid; + struct key *idkey; + const struct cred *saved_cred; + struct cifs_sid_id *psidid, *npsidid; + struct rb_root *cidtree; + spinlock_t *cidlock; + + if (sidtype == SIDOWNER) { + cid = cifs_sb->mnt_uid; /* default uid, in case upcall fails */ + cidlock = &siduidlock; + cidtree = &uidtree; + } else if (sidtype == SIDGROUP) { + cid = cifs_sb->mnt_gid; /* default gid, in case upcall fails */ + cidlock = &sidgidlock; + cidtree = &gidtree; + } else + return -ENOENT; + + spin_lock(cidlock); + psidid = id_rb_search(cidtree, psid); + + if (!psidid) { /* node does not exist, allocate one & attempt adding */ + spin_unlock(cidlock); + npsidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL); + if (!npsidid) + return -ENOMEM; + + npsidid->sidstr = kmalloc(SIDLEN, GFP_KERNEL); + if (!npsidid->sidstr) { + kfree(npsidid); + return -ENOMEM; + } + + spin_lock(cidlock); + psidid = id_rb_search(cidtree, psid); + if (psidid) { /* node happened to get inserted meanwhile */ + ++psidid->refcount; + spin_unlock(cidlock); + kfree(npsidid->sidstr); + kfree(npsidid); + } else { + psidid = npsidid; + id_rb_insert(cidtree, psid, &psidid, + sidtype == SIDOWNER ? "os:" : "gs:"); + ++psidid->refcount; + spin_unlock(cidlock); + } + } else { + ++psidid->refcount; + spin_unlock(cidlock); + } + + /* + * If we are here, it is safe to access psidid and its fields + * since a reference was taken earlier while holding the spinlock. + * A reference on the node is put without holding the spinlock + * and it is OK to do so in this case, shrinker will not erase + * this node until all references are put and we do not access + * any fields of the node after a reference is put . + */ + if (test_bit(SID_ID_MAPPED, &psidid->state)) { + cid = psidid->id; + psidid->time = jiffies; /* update ts for accessing */ + goto sid_to_id_out; + } + + if (time_after(psidid->time + SID_MAP_RETRY, jiffies)) + goto sid_to_id_out; + + if (!test_and_set_bit(SID_ID_PENDING, &psidid->state)) { + saved_cred = override_creds(root_cred); + idkey = request_key(&cifs_idmap_key_type, psidid->sidstr, ""); + if (IS_ERR(idkey)) + cFYI(1, "%s: Can't map SID to an id", __func__); + else { + cid = *(unsigned long *)idkey->payload.value; + psidid->id = cid; + set_bit(SID_ID_MAPPED, &psidid->state); + key_put(idkey); + kfree(psidid->sidstr); + } + revert_creds(saved_cred); + psidid->time = jiffies; /* update ts for accessing */ + clear_bit(SID_ID_PENDING, &psidid->state); + wake_up_bit(&psidid->state, SID_ID_PENDING); + } else { + rc = wait_on_bit(&psidid->state, SID_ID_PENDING, + sidid_pending_wait, TASK_INTERRUPTIBLE); + if (rc) { + cFYI(1, "%s: sidid_pending_wait interrupted %d", + __func__, rc); + --psidid->refcount; /* decremented without spinlock */ + return rc; + } + if (test_bit(SID_ID_MAPPED, &psidid->state)) + cid = psidid->id; + } + +sid_to_id_out: + --psidid->refcount; /* decremented without spinlock */ + if (sidtype == SIDOWNER) + fattr->cf_uid = cid; + else + fattr->cf_gid = cid; + + return 0; +} + +int +init_cifs_idmap(void) +{ + struct cred *cred; + struct key *keyring; + int ret; + + cFYI(1, "Registering the %s key type\n", cifs_idmap_key_type.name); + + /* create an override credential set with a special thread keyring in + * which requests are cached + * + * this is used to prevent malicious redirections from being installed + * with add_key(). + */ + cred = prepare_kernel_cred(NULL); + if (!cred) + return -ENOMEM; + + keyring = key_alloc(&key_type_keyring, ".cifs_idmap", 0, 0, cred, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ, + KEY_ALLOC_NOT_IN_QUOTA); + if (IS_ERR(keyring)) { + ret = PTR_ERR(keyring); + goto failed_put_cred; + } + + ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL); + if (ret < 0) + goto failed_put_key; + + ret = register_key_type(&cifs_idmap_key_type); + if (ret < 0) + goto failed_put_key; + + /* instruct request_key() to use this special keyring as a cache for + * the results it looks up */ + set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags); + cred->thread_keyring = keyring; + cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING; + root_cred = cred; + + spin_lock_init(&siduidlock); + uidtree = RB_ROOT; + spin_lock_init(&sidgidlock); + gidtree = RB_ROOT; + + spin_lock_init(&uidsidlock); + siduidtree = RB_ROOT; + spin_lock_init(&gidsidlock); + sidgidtree = RB_ROOT; + register_shrinker(&cifs_shrinker); + + cFYI(1, "cifs idmap keyring: %d\n", key_serial(keyring)); + return 0; + +failed_put_key: + key_put(keyring); +failed_put_cred: + put_cred(cred); + return ret; +} + +void +exit_cifs_idmap(void) +{ + key_revoke(root_cred->thread_keyring); + unregister_key_type(&cifs_idmap_key_type); + put_cred(root_cred); + unregister_shrinker(&cifs_shrinker); + cFYI(1, "Unregistered %s key type\n", cifs_idmap_key_type.name); +} + +void +cifs_destroy_idmaptrees(void) +{ + struct rb_root *root; + struct rb_node *node; + + root = &uidtree; + spin_lock(&siduidlock); + while ((node = rb_first(root))) + rb_erase(node, root); + spin_unlock(&siduidlock); + + root = &gidtree; + spin_lock(&sidgidlock); + while ((node = rb_first(root))) + rb_erase(node, root); + spin_unlock(&sidgidlock); + + root = &siduidtree; + spin_lock(&uidsidlock); + while ((node = rb_first(root))) + rb_erase(node, root); + spin_unlock(&uidsidlock); + + root = &sidgidtree; + spin_lock(&gidsidlock); + while ((node = rb_first(root))) + rb_erase(node, root); + spin_unlock(&gidsidlock); +} + +/* if the two SIDs (roughly equivalent to a UUID for a user or group) are + the same returns 1, if they do not match returns 0 */ +int compare_sids(const struct cifs_sid *ctsid, const struct cifs_sid *cwsid) +{ + int i; + int num_subauth, num_sat, num_saw; + + if ((!ctsid) || (!cwsid)) + return 1; + + /* compare the revision */ + if (ctsid->revision != cwsid->revision) { + if (ctsid->revision > cwsid->revision) + return 1; + else + return -1; + } + + /* compare all of the six auth values */ + for (i = 0; i < 6; ++i) { + if (ctsid->authority[i] != cwsid->authority[i]) { + if (ctsid->authority[i] > cwsid->authority[i]) + return 1; + else + return -1; + } + } + + /* compare all of the subauth values if any */ + num_sat = ctsid->num_subauth; + num_saw = cwsid->num_subauth; + num_subauth = num_sat < num_saw ? num_sat : num_saw; + if (num_subauth) { + for (i = 0; i < num_subauth; ++i) { + if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) { + if (le32_to_cpu(ctsid->sub_auth[i]) > + le32_to_cpu(cwsid->sub_auth[i])) + return 1; + else + return -1; + } + } + } + + return 0; /* sids compare/match */ +} + + +/* copy ntsd, owner sid, and group sid from a security descriptor to another */ +static void copy_sec_desc(const struct cifs_ntsd *pntsd, + struct cifs_ntsd *pnntsd, __u32 sidsoffset) +{ + int i; + + struct cifs_sid *owner_sid_ptr, *group_sid_ptr; + struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr; + + /* copy security descriptor control portion */ + pnntsd->revision = pntsd->revision; + pnntsd->type = pntsd->type; + pnntsd->dacloffset = cpu_to_le32(sizeof(struct cifs_ntsd)); + pnntsd->sacloffset = 0; + pnntsd->osidoffset = cpu_to_le32(sidsoffset); + pnntsd->gsidoffset = cpu_to_le32(sidsoffset + sizeof(struct cifs_sid)); + + /* copy owner sid */ + owner_sid_ptr = (struct cifs_sid *)((char *)pntsd + + le32_to_cpu(pntsd->osidoffset)); + nowner_sid_ptr = (struct cifs_sid *)((char *)pnntsd + sidsoffset); + + nowner_sid_ptr->revision = owner_sid_ptr->revision; + nowner_sid_ptr->num_subauth = owner_sid_ptr->num_subauth; + for (i = 0; i < 6; i++) + nowner_sid_ptr->authority[i] = owner_sid_ptr->authority[i]; + for (i = 0; i < 5; i++) + nowner_sid_ptr->sub_auth[i] = owner_sid_ptr->sub_auth[i]; + + /* copy group sid */ + group_sid_ptr = (struct cifs_sid *)((char *)pntsd + + le32_to_cpu(pntsd->gsidoffset)); + ngroup_sid_ptr = (struct cifs_sid *)((char *)pnntsd + sidsoffset + + sizeof(struct cifs_sid)); + + ngroup_sid_ptr->revision = group_sid_ptr->revision; + ngroup_sid_ptr->num_subauth = group_sid_ptr->num_subauth; + for (i = 0; i < 6; i++) + ngroup_sid_ptr->authority[i] = group_sid_ptr->authority[i]; + for (i = 0; i < 5; i++) + ngroup_sid_ptr->sub_auth[i] = group_sid_ptr->sub_auth[i]; + + return; +} + + +/* + change posix mode to reflect permissions + pmode is the existing mode (we only want to overwrite part of this + bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007 +*/ +static void access_flags_to_mode(__le32 ace_flags, int type, umode_t *pmode, + umode_t *pbits_to_set) +{ + __u32 flags = le32_to_cpu(ace_flags); + /* the order of ACEs is important. The canonical order is to begin with + DENY entries followed by ALLOW, otherwise an allow entry could be + encountered first, making the subsequent deny entry like "dead code" + which would be superflous since Windows stops when a match is made + for the operation you are trying to perform for your user */ + + /* For deny ACEs we change the mask so that subsequent allow access + control entries do not turn on the bits we are denying */ + if (type == ACCESS_DENIED) { + if (flags & GENERIC_ALL) + *pbits_to_set &= ~S_IRWXUGO; + + if ((flags & GENERIC_WRITE) || + ((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS)) + *pbits_to_set &= ~S_IWUGO; + if ((flags & GENERIC_READ) || + ((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS)) + *pbits_to_set &= ~S_IRUGO; + if ((flags & GENERIC_EXECUTE) || + ((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS)) + *pbits_to_set &= ~S_IXUGO; + return; + } else if (type != ACCESS_ALLOWED) { + cERROR(1, "unknown access control type %d", type); + return; + } + /* else ACCESS_ALLOWED type */ + + if (flags & GENERIC_ALL) { + *pmode |= (S_IRWXUGO & (*pbits_to_set)); + cFYI(DBG2, "all perms"); + return; + } + if ((flags & GENERIC_WRITE) || + ((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS)) + *pmode |= (S_IWUGO & (*pbits_to_set)); + if ((flags & GENERIC_READ) || + ((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS)) + *pmode |= (S_IRUGO & (*pbits_to_set)); + if ((flags & GENERIC_EXECUTE) || + ((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS)) + *pmode |= (S_IXUGO & (*pbits_to_set)); + + cFYI(DBG2, "access flags 0x%x mode now 0x%x", flags, *pmode); + return; +} + +/* + Generate access flags to reflect permissions mode is the existing mode. + This function is called for every ACE in the DACL whose SID matches + with either owner or group or everyone. +*/ + +static void mode_to_access_flags(umode_t mode, umode_t bits_to_use, + __u32 *pace_flags) +{ + /* reset access mask */ + *pace_flags = 0x0; + + /* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */ + mode &= bits_to_use; + + /* check for R/W/X UGO since we do not know whose flags + is this but we have cleared all the bits sans RWX for + either user or group or other as per bits_to_use */ + if (mode & S_IRUGO) + *pace_flags |= SET_FILE_READ_RIGHTS; + if (mode & S_IWUGO) + *pace_flags |= SET_FILE_WRITE_RIGHTS; + if (mode & S_IXUGO) + *pace_flags |= SET_FILE_EXEC_RIGHTS; + + cFYI(DBG2, "mode: 0x%x, access flags now 0x%x", mode, *pace_flags); + return; +} + +static __u16 fill_ace_for_sid(struct cifs_ace *pntace, + const struct cifs_sid *psid, __u64 nmode, umode_t bits) +{ + int i; + __u16 size = 0; + __u32 access_req = 0; + + pntace->type = ACCESS_ALLOWED; + pntace->flags = 0x0; + mode_to_access_flags(nmode, bits, &access_req); + if (!access_req) + access_req = SET_MINIMUM_RIGHTS; + pntace->access_req = cpu_to_le32(access_req); + + pntace->sid.revision = psid->revision; + pntace->sid.num_subauth = psid->num_subauth; + for (i = 0; i < 6; i++) + pntace->sid.authority[i] = psid->authority[i]; + for (i = 0; i < psid->num_subauth; i++) + pntace->sid.sub_auth[i] = psid->sub_auth[i]; + + size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth * 4); + pntace->size = cpu_to_le16(size); + + return size; +} + + +#ifdef CONFIG_CIFS_DEBUG2 +static void dump_ace(struct cifs_ace *pace, char *end_of_acl) +{ + int num_subauth; + + /* validate that we do not go past end of acl */ + + if (le16_to_cpu(pace->size) < 16) { + cERROR(1, "ACE too small %d", le16_to_cpu(pace->size)); + return; + } + + if (end_of_acl < (char *)pace + le16_to_cpu(pace->size)) { + cERROR(1, "ACL too small to parse ACE"); + return; + } + + num_subauth = pace->sid.num_subauth; + if (num_subauth) { + int i; + cFYI(1, "ACE revision %d num_auth %d type %d flags %d size %d", + pace->sid.revision, pace->sid.num_subauth, pace->type, + pace->flags, le16_to_cpu(pace->size)); + for (i = 0; i < num_subauth; ++i) { + cFYI(1, "ACE sub_auth[%d]: 0x%x", i, + le32_to_cpu(pace->sid.sub_auth[i])); + } + + /* BB add length check to make sure that we do not have huge + num auths and therefore go off the end */ + } + + return; +} +#endif + + +static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl, + struct cifs_sid *pownersid, struct cifs_sid *pgrpsid, + struct cifs_fattr *fattr) +{ + int i; + int num_aces = 0; + int acl_size; + char *acl_base; + struct cifs_ace **ppace; + + /* BB need to add parm so we can store the SID BB */ + + if (!pdacl) { + /* no DACL in the security descriptor, set + all the permissions for user/group/other */ + fattr->cf_mode |= S_IRWXUGO; + return; + } + + /* validate that we do not go past end of acl */ + if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) { + cERROR(1, "ACL too small to parse DACL"); + return; + } + + cFYI(DBG2, "DACL revision %d size %d num aces %d", + le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size), + le32_to_cpu(pdacl->num_aces)); + + /* reset rwx permissions for user/group/other. + Also, if num_aces is 0 i.e. DACL has no ACEs, + user/group/other have no permissions */ + fattr->cf_mode &= ~(S_IRWXUGO); + + acl_base = (char *)pdacl; + acl_size = sizeof(struct cifs_acl); + + num_aces = le32_to_cpu(pdacl->num_aces); + if (num_aces > 0) { + umode_t user_mask = S_IRWXU; + umode_t group_mask = S_IRWXG; + umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO; + + if (num_aces > ULONG_MAX / sizeof(struct cifs_ace *)) + return; + ppace = kmalloc(num_aces * sizeof(struct cifs_ace *), + GFP_KERNEL); + if (!ppace) { + cERROR(1, "DACL memory allocation error"); + return; + } + + for (i = 0; i < num_aces; ++i) { + ppace[i] = (struct cifs_ace *) (acl_base + acl_size); +#ifdef CONFIG_CIFS_DEBUG2 + dump_ace(ppace[i], end_of_acl); +#endif + if (compare_sids(&(ppace[i]->sid), pownersid) == 0) + access_flags_to_mode(ppace[i]->access_req, + ppace[i]->type, + &fattr->cf_mode, + &user_mask); + if (compare_sids(&(ppace[i]->sid), pgrpsid) == 0) + access_flags_to_mode(ppace[i]->access_req, + ppace[i]->type, + &fattr->cf_mode, + &group_mask); + if (compare_sids(&(ppace[i]->sid), &sid_everyone) == 0) + access_flags_to_mode(ppace[i]->access_req, + ppace[i]->type, + &fattr->cf_mode, + &other_mask); + if (compare_sids(&(ppace[i]->sid), &sid_authusers) == 0) + access_flags_to_mode(ppace[i]->access_req, + ppace[i]->type, + &fattr->cf_mode, + &other_mask); + + +/* memcpy((void *)(&(cifscred->aces[i])), + (void *)ppace[i], + sizeof(struct cifs_ace)); */ + + acl_base = (char *)ppace[i]; + acl_size = le16_to_cpu(ppace[i]->size); + } + + kfree(ppace); + } + + return; +} + + +static int set_chmod_dacl(struct cifs_acl *pndacl, struct cifs_sid *pownersid, + struct cifs_sid *pgrpsid, __u64 nmode) +{ + u16 size = 0; + struct cifs_acl *pnndacl; + + pnndacl = (struct cifs_acl *)((char *)pndacl + sizeof(struct cifs_acl)); + + size += fill_ace_for_sid((struct cifs_ace *) ((char *)pnndacl + size), + pownersid, nmode, S_IRWXU); + size += fill_ace_for_sid((struct cifs_ace *)((char *)pnndacl + size), + pgrpsid, nmode, S_IRWXG); + size += fill_ace_for_sid((struct cifs_ace *)((char *)pnndacl + size), + &sid_everyone, nmode, S_IRWXO); + + pndacl->size = cpu_to_le16(size + sizeof(struct cifs_acl)); + pndacl->num_aces = cpu_to_le32(3); + + return 0; +} + + +static int parse_sid(struct cifs_sid *psid, char *end_of_acl) +{ + /* BB need to add parm so we can store the SID BB */ + + /* validate that we do not go past end of ACL - sid must be at least 8 + bytes long (assuming no sub-auths - e.g. the null SID */ + if (end_of_acl < (char *)psid + 8) { + cERROR(1, "ACL too small to parse SID %p", psid); + return -EINVAL; + } + + if (psid->num_subauth) { +#ifdef CONFIG_CIFS_DEBUG2 + int i; + cFYI(1, "SID revision %d num_auth %d", + psid->revision, psid->num_subauth); + + for (i = 0; i < psid->num_subauth; i++) { + cFYI(1, "SID sub_auth[%d]: 0x%x ", i, + le32_to_cpu(psid->sub_auth[i])); + } + + /* BB add length check to make sure that we do not have huge + num auths and therefore go off the end */ + cFYI(1, "RID 0x%x", + le32_to_cpu(psid->sub_auth[psid->num_subauth-1])); +#endif + } + + return 0; +} + + +/* Convert CIFS ACL to POSIX form */ +static int parse_sec_desc(struct cifs_sb_info *cifs_sb, + struct cifs_ntsd *pntsd, int acl_len, struct cifs_fattr *fattr) +{ + int rc = 0; + struct cifs_sid *owner_sid_ptr, *group_sid_ptr; + struct cifs_acl *dacl_ptr; /* no need for SACL ptr */ + char *end_of_acl = ((char *)pntsd) + acl_len; + __u32 dacloffset; + + if (pntsd == NULL) + return -EIO; + + owner_sid_ptr = (struct cifs_sid *)((char *)pntsd + + le32_to_cpu(pntsd->osidoffset)); + group_sid_ptr = (struct cifs_sid *)((char *)pntsd + + le32_to_cpu(pntsd->gsidoffset)); + dacloffset = le32_to_cpu(pntsd->dacloffset); + dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset); + cFYI(DBG2, "revision %d type 0x%x ooffset 0x%x goffset 0x%x " + "sacloffset 0x%x dacloffset 0x%x", + pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset), + le32_to_cpu(pntsd->gsidoffset), + le32_to_cpu(pntsd->sacloffset), dacloffset); +/* cifs_dump_mem("owner_sid: ", owner_sid_ptr, 64); */ + rc = parse_sid(owner_sid_ptr, end_of_acl); + if (rc) { + cFYI(1, "%s: Error %d parsing Owner SID", __func__, rc); + return rc; + } + rc = sid_to_id(cifs_sb, owner_sid_ptr, fattr, SIDOWNER); + if (rc) { + cFYI(1, "%s: Error %d mapping Owner SID to uid", __func__, rc); + return rc; + } + + rc = parse_sid(group_sid_ptr, end_of_acl); + if (rc) { + cFYI(1, "%s: Error %d mapping Owner SID to gid", __func__, rc); + return rc; + } + rc = sid_to_id(cifs_sb, group_sid_ptr, fattr, SIDGROUP); + if (rc) { + cFYI(1, "%s: Error %d mapping Group SID to gid", __func__, rc); + return rc; + } + + if (dacloffset) + parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr, + group_sid_ptr, fattr); + else + cFYI(1, "no ACL"); /* BB grant all or default perms? */ + + return rc; +} + +/* Convert permission bits from mode to equivalent CIFS ACL */ +static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd, + __u32 secdesclen, __u64 nmode, uid_t uid, gid_t gid, int *aclflag) +{ + int rc = 0; + __u32 dacloffset; + __u32 ndacloffset; + __u32 sidsoffset; + struct cifs_sid *owner_sid_ptr, *group_sid_ptr; + struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr; + struct cifs_acl *dacl_ptr = NULL; /* no need for SACL ptr */ + struct cifs_acl *ndacl_ptr = NULL; /* no need for SACL ptr */ + + if (nmode != NO_CHANGE_64) { /* chmod */ + owner_sid_ptr = (struct cifs_sid *)((char *)pntsd + + le32_to_cpu(pntsd->osidoffset)); + group_sid_ptr = (struct cifs_sid *)((char *)pntsd + + le32_to_cpu(pntsd->gsidoffset)); + dacloffset = le32_to_cpu(pntsd->dacloffset); + dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset); + ndacloffset = sizeof(struct cifs_ntsd); + ndacl_ptr = (struct cifs_acl *)((char *)pnntsd + ndacloffset); + ndacl_ptr->revision = dacl_ptr->revision; + ndacl_ptr->size = 0; + ndacl_ptr->num_aces = 0; + + rc = set_chmod_dacl(ndacl_ptr, owner_sid_ptr, group_sid_ptr, + nmode); + sidsoffset = ndacloffset + le16_to_cpu(ndacl_ptr->size); + /* copy sec desc control portion & owner and group sids */ + copy_sec_desc(pntsd, pnntsd, sidsoffset); + *aclflag = CIFS_ACL_DACL; + } else { + memcpy(pnntsd, pntsd, secdesclen); + if (uid != NO_CHANGE_32) { /* chown */ + owner_sid_ptr = (struct cifs_sid *)((char *)pnntsd + + le32_to_cpu(pnntsd->osidoffset)); + nowner_sid_ptr = kmalloc(sizeof(struct cifs_sid), + GFP_KERNEL); + if (!nowner_sid_ptr) + return -ENOMEM; + rc = id_to_sid(uid, SIDOWNER, nowner_sid_ptr); + if (rc) { + cFYI(1, "%s: Mapping error %d for owner id %d", + __func__, rc, uid); + kfree(nowner_sid_ptr); + return rc; + } + memcpy(owner_sid_ptr, nowner_sid_ptr, + sizeof(struct cifs_sid)); + kfree(nowner_sid_ptr); + *aclflag = CIFS_ACL_OWNER; + } + if (gid != NO_CHANGE_32) { /* chgrp */ + group_sid_ptr = (struct cifs_sid *)((char *)pnntsd + + le32_to_cpu(pnntsd->gsidoffset)); + ngroup_sid_ptr = kmalloc(sizeof(struct cifs_sid), + GFP_KERNEL); + if (!ngroup_sid_ptr) + return -ENOMEM; + rc = id_to_sid(gid, SIDGROUP, ngroup_sid_ptr); + if (rc) { + cFYI(1, "%s: Mapping error %d for group id %d", + __func__, rc, gid); + kfree(ngroup_sid_ptr); + return rc; + } + memcpy(group_sid_ptr, ngroup_sid_ptr, + sizeof(struct cifs_sid)); + kfree(ngroup_sid_ptr); + *aclflag = CIFS_ACL_GROUP; + } + } + + return rc; +} + +static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb, + __u16 fid, u32 *pacllen) +{ + struct cifs_ntsd *pntsd = NULL; + int xid, rc; + struct tcon_link *tlink = cifs_sb_tlink(cifs_sb); + + if (IS_ERR(tlink)) + return ERR_CAST(tlink); + + xid = GetXid(); + rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen); + FreeXid(xid); + + cifs_put_tlink(tlink); + + cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen); + if (rc) + return ERR_PTR(rc); + return pntsd; +} + +static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb, + const char *path, u32 *pacllen) +{ + struct cifs_ntsd *pntsd = NULL; + int oplock = 0; + int xid, rc, create_options = 0; + __u16 fid; + struct cifs_tcon *tcon; + struct tcon_link *tlink = cifs_sb_tlink(cifs_sb); + + if (IS_ERR(tlink)) + return ERR_CAST(tlink); + + tcon = tlink_tcon(tlink); + xid = GetXid(); + + if (backup_cred(cifs_sb)) + create_options |= CREATE_OPEN_BACKUP_INTENT; + + rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, READ_CONTROL, + create_options, &fid, &oplock, NULL, cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); + if (!rc) { + rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen); + CIFSSMBClose(xid, tcon, fid); + } + + cifs_put_tlink(tlink); + FreeXid(xid); + + cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen); + if (rc) + return ERR_PTR(rc); + return pntsd; +} + +/* Retrieve an ACL from the server */ +struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb, + struct inode *inode, const char *path, + u32 *pacllen) +{ + struct cifs_ntsd *pntsd = NULL; + struct cifsFileInfo *open_file = NULL; + + if (inode) + open_file = find_readable_file(CIFS_I(inode), true); + if (!open_file) + return get_cifs_acl_by_path(cifs_sb, path, pacllen); + + pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->netfid, pacllen); + cifsFileInfo_put(open_file); + return pntsd; +} + + /* Set an ACL on the server */ +int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen, + struct inode *inode, const char *path, int aclflag) +{ + int oplock = 0; + int xid, rc, access_flags, create_options = 0; + __u16 fid; + struct cifs_tcon *tcon; + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct tcon_link *tlink = cifs_sb_tlink(cifs_sb); + + if (IS_ERR(tlink)) + return PTR_ERR(tlink); + + tcon = tlink_tcon(tlink); + xid = GetXid(); + + if (backup_cred(cifs_sb)) + create_options |= CREATE_OPEN_BACKUP_INTENT; + + if (aclflag == CIFS_ACL_OWNER || aclflag == CIFS_ACL_GROUP) + access_flags = WRITE_OWNER; + else + access_flags = WRITE_DAC; + + rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, access_flags, + create_options, &fid, &oplock, NULL, cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); + if (rc) { + cERROR(1, "Unable to open file to set ACL"); + goto out; + } + + rc = CIFSSMBSetCIFSACL(xid, tcon, fid, pnntsd, acllen, aclflag); + cFYI(DBG2, "SetCIFSACL rc = %d", rc); + + CIFSSMBClose(xid, tcon, fid); +out: + FreeXid(xid); + cifs_put_tlink(tlink); + return rc; +} + +/* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */ +int +cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr, + struct inode *inode, const char *path, const __u16 *pfid) +{ + struct cifs_ntsd *pntsd = NULL; + u32 acllen = 0; + int rc = 0; + + cFYI(DBG2, "converting ACL to mode for %s", path); + + if (pfid) + pntsd = get_cifs_acl_by_fid(cifs_sb, *pfid, &acllen); + else + pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen); + + /* if we can retrieve the ACL, now parse Access Control Entries, ACEs */ + if (IS_ERR(pntsd)) { + rc = PTR_ERR(pntsd); + cERROR(1, "%s: error %d getting sec desc", __func__, rc); + } else { + rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr); + kfree(pntsd); + if (rc) + cERROR(1, "parse sec desc failed rc = %d", rc); + } + + return rc; +} + +/* Convert mode bits to an ACL so we can update the ACL on the server */ +int +id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode, + uid_t uid, gid_t gid) +{ + int rc = 0; + int aclflag = CIFS_ACL_DACL; /* default flag to set */ + __u32 secdesclen = 0; + struct cifs_ntsd *pntsd = NULL; /* acl obtained from server */ + struct cifs_ntsd *pnntsd = NULL; /* modified acl to be sent to server */ + + cFYI(DBG2, "set ACL from mode for %s", path); + + /* Get the security descriptor */ + pntsd = get_cifs_acl(CIFS_SB(inode->i_sb), inode, path, &secdesclen); + + /* Add three ACEs for owner, group, everyone getting rid of + other ACEs as chmod disables ACEs and set the security descriptor */ + + if (IS_ERR(pntsd)) { + rc = PTR_ERR(pntsd); + cERROR(1, "%s: error %d getting sec desc", __func__, rc); + } else { + /* allocate memory for the smb header, + set security descriptor request security descriptor + parameters, and secuirty descriptor itself */ + + secdesclen = secdesclen < DEFSECDESCLEN ? + DEFSECDESCLEN : secdesclen; + pnntsd = kmalloc(secdesclen, GFP_KERNEL); + if (!pnntsd) { + cERROR(1, "Unable to allocate security descriptor"); + kfree(pntsd); + return -ENOMEM; + } + + rc = build_sec_desc(pntsd, pnntsd, secdesclen, nmode, uid, gid, + &aclflag); + + cFYI(DBG2, "build_sec_desc rc: %d", rc); + + if (!rc) { + /* Set the security descriptor */ + rc = set_cifs_acl(pnntsd, secdesclen, inode, + path, aclflag); + cFYI(DBG2, "set_cifs_acl rc: %d", rc); + } + + kfree(pnntsd); + kfree(pntsd); + } + + return rc; +} |