access-control : validating context of access control translator

By introduction of new acl conversion from http://review.gluster.org/#/c/9627/,
an acl can be set using GF_POSIX_ACL_*_KEY xattrs without notifying the
access-control translator. So evenif an acl is set correctly at the backend, it
might not work properly because access-control holds wrong acl information in
its context about that file.

Note : This is a simple workaround. The actual solution consists of three steps:
1.) Use new acl api's for acl conversion.
2.) Move the acl conversion part from access-control translator
3.) Introduces standard acl structures and libaries in access-translator
for caching, enforcing purposes.

Change-Id: Iacb6b323810ebe82f7f171f20be16429463cbcf0
BUG: 1229860
Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>
Reviewed-on: http://review.gluster.org/11144
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>

4 files changed, 227 insertions, 7 deletions

diff --git a/xlators/storage/posix/src/posix-messages.h b/xlators/storage/posix/src/posix-messages.h
index 9916aed92cd..9f267dfe0d9 100644
--- a/xlators/storage/posix/src/posix-messages.h
+++ b/xlators/storage/posix/src/posix-messages.h
@@ -893,6 +893,14 @@
  *
  */
 
+#define P_MSG_BUFFER_OVERFLOW                   (POSIX_COMP_BASE + 105)
+/*!
+ * @messageid
+ * @diagnosis
+ * @recommendedaction
+ *
+ */
+
 /*------------*/
 #define glfs_msg_end_x GLFS_MSGID_END, "Invalid: End of messages"
 
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 5e9dbf7ee5c..36d2c857835 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -3266,8 +3266,10 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
         int32_t       op_ret                  = -1;
         int32_t       op_errno                = 0;
         char *        real_path               = NULL;
+        char         *acl_xattr               = NULL;
         struct iatt   stbuf                   = {0};
         int32_t       ret                     = 0;
+        size_t        acl_size                = 0;
         dict_t       *xattr                   = NULL;
         posix_xattr_filler_t filler = {0,};
 
@@ -3306,6 +3308,10 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
                 goto out;
         }
 
+        xattr = dict_new();
+        if (!xattr)
+                goto out;
+
 /*
  * FIXFIX: Send the stbuf info in the xdata for now
  * This is used by DHT to redirect FOPs if the file is being migrated
@@ -3316,10 +3322,98 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
                 if (ret)
                         goto out;
 
-                xattr = dict_new();
-                if (!xattr)
+               ret = posix_set_iatt_in_dict (xattr, &stbuf);
+        }
+
+/*
+ * ACL can be set on a file/folder using GF_POSIX_ACL_*_KEY xattrs which
+ * won't aware of access-control xlator. To update its context correctly,
+ * POSIX_ACL_*_XATTR stored in xdata which is send in the call_back path.
+ */
+        if (dict_get (dict, GF_POSIX_ACL_ACCESS)) {
+
+                /*
+                 * The size of buffer will be know after calling sys_lgetxattr,
+                 * so first we allocate buffer with large size(~4k), then we
+                 * reduced into required size using GF_REALLO().
+                 */
+                acl_xattr = GF_CALLOC (1, ACL_BUFFER_MAX, gf_posix_mt_char);
+                if (!acl_xattr) {
+                        ret = -1;
                         goto out;
-                ret = posix_set_iatt_in_dict (xattr, &stbuf);
+                }
+
+                acl_size = sys_lgetxattr (real_path, POSIX_ACL_ACCESS_XATTR,
+                                          acl_xattr, ACL_BUFFER_MAX);
+
+                if (acl_size < 0) {
+                        gf_msg (this->name, GF_LOG_WARNING, errno,
+                                P_MSG_XATTR_FAILED, "Posix acl is not set "
+                                "properly at the backend");
+                        ret = -1;
+                        goto out;
+                }
+
+                /* If acl_size is more than max buffer size, just ignore it */
+                if (acl_size >= ACL_BUFFER_MAX) {
+                        gf_msg (this->name, GF_LOG_WARNING, ENOMEM,
+                                P_MSG_BUFFER_OVERFLOW, "size of acl is more"
+                                "than the buffer");
+                        ret = -1;
+                        goto out;
+                }
+
+                acl_xattr = GF_REALLOC (acl_xattr, acl_size);
+                ret = dict_set_bin (xattr, POSIX_ACL_ACCESS_XATTR,
+                                    acl_xattr, acl_size);
+                if (ret) {
+                        gf_msg (this->name, GF_LOG_WARNING, 0,
+                                P_MSG_SET_XDATA_FAIL, "failed to set"
+                                "xdata for acl");
+                        ret = -1;
+                        goto out;
+                }
+        }
+
+        GF_FREE (acl_xattr);
+        acl_xattr = NULL;
+
+        if (dict_get (dict, GF_POSIX_ACL_DEFAULT)) {
+
+                acl_xattr = GF_CALLOC (1, ACL_BUFFER_MAX, gf_posix_mt_char);
+                if (!acl_xattr) {
+                        ret = -1;
+                        goto out;
+                }
+                acl_size = sys_lgetxattr (real_path, POSIX_ACL_DEFAULT_XATTR,
+                                          acl_xattr, ACL_BUFFER_MAX);
+
+                if (acl_size < 0) {
+                        gf_msg (this->name, GF_LOG_WARNING, errno,
+                                P_MSG_XATTR_FAILED, "Posix acl is not set "
+                                "properly at the backend");
+                        ret = -1;
+                        goto out;
+                }
+
+                if (acl_size >= ACL_BUFFER_MAX) {
+                        gf_msg (this->name, GF_LOG_WARNING, ENOMEM,
+                                P_MSG_BUFFER_OVERFLOW, "size of acl is more"
+                                "than the buffer");
+                        ret = -1;
+                        goto out;
+                }
+
+                acl_xattr = GF_REALLOC (acl_xattr, acl_size);
+                ret = dict_set_bin (xattr, POSIX_ACL_DEFAULT_XATTR,
+                                    acl_xattr, acl_size);
+                if (ret) {
+                        gf_msg (this->name, GF_LOG_WARNING, 0,
+                                P_MSG_SET_XDATA_FAIL, "failed to set"
+                                "xdata for acl");
+                        ret = -1;
+                        goto out;
+                }
         }
 out:
         SET_TO_OLD_FS_ID ();
@@ -3329,6 +3423,9 @@ out:
         if (xattr)
                 dict_unref(xattr);
 
+        if (acl_xattr)
+                GF_FREE (acl_xattr);
+
         return 0;
 }
 
diff --git a/xlators/storage/posix/src/posix.h b/xlators/storage/posix/src/posix.h
index b85338e930e..cc7ed0402fe 100644
--- a/xlators/storage/posix/src/posix.h
+++ b/xlators/storage/posix/src/posix.h
@@ -48,6 +48,8 @@
 #define VECTOR_SIZE 64 * 1024 /* vector size 64KB*/
 #define MAX_NO_VECT 1024
 
+#define ACL_BUFFER_MAX 4096 /* size of character buffer */
+
 #define LINKTO "trusted.glusterfs.dht.linkto"
 
 #define POSIX_GFID_HANDLE_SIZE(base_path_len) (base_path_len + SLEN("/") \
diff --git a/xlators/system/posix-acl/src/posix-acl.c b/xlators/system/posix-acl/src/posix-acl.c
index 05608696ea6..da2ccbd1c54 100644
--- a/xlators/system/posix-acl/src/posix-acl.c
+++ b/xlators/system/posix-acl/src/posix-acl.c
@@ -306,6 +306,26 @@ posix_acl_ctx_get (inode_t *inode, xlator_t *this)
         return ctx;
 }
 
+int
+__posix_acl_set_specific (inode_t *inode, xlator_t *this,
+                          gf_boolean_t is_access, struct posix_acl *acl)
+{
+        int                    ret = 0;
+        struct posix_acl_ctx  *ctx = NULL;
+
+        ctx = posix_acl_ctx_get (inode, this);
+        if (!ctx) {
+                ret = -1;
+                goto out;
+        }
+
+        if (is_access)
+                ctx->acl_access = acl;
+        else
+                ctx->acl_default = acl;
+out:
+        return ret;
+}
 
 int
 __posix_acl_set (inode_t *inode, xlator_t *this, struct posix_acl *acl_access,
@@ -426,6 +446,36 @@ posix_acl_unref (xlator_t *this, struct posix_acl *acl)
                 posix_acl_destroy (this, acl);
 }
 
+int
+posix_acl_set_specific (inode_t *inode, xlator_t *this, struct posix_acl *acl,
+                        gf_boolean_t is_access)
+{
+        int                     ret = 0;
+        int                     oldret = 0;
+        struct posix_acl       *old_acl = NULL;
+        struct posix_acl_conf  *conf = NULL;
+
+        conf = this->private;
+
+        LOCK (&conf->acl_lock);
+        {
+                if (is_access)
+                        oldret = __posix_acl_get (inode, this, &old_acl, NULL);
+                else
+                        oldret = __posix_acl_get (inode, this, NULL, &old_acl);
+                if (acl)
+                        acl->refcnt++;
+                ret = __posix_acl_set_specific (inode, this, is_access, acl);
+        }
+        UNLOCK (&conf->acl_lock);
+
+        if (oldret == 0) {
+                if (old_acl)
+                        posix_acl_unref (this, old_acl);
+        }
+
+        return ret;
+}
 
 int
 posix_acl_set (inode_t *inode, xlator_t *this, struct posix_acl *acl_access,
@@ -497,7 +547,6 @@ unlock:
         return ret;
 }
 
-
 mode_t
 posix_acl_inherit_mode (struct posix_acl *acl, mode_t modein)
 {
@@ -1883,11 +1932,71 @@ posix_acl_setxattr_update (xlator_t *this, inode_t *inode, dict_t *xattr)
         return ret;
 }
 
+/* *
+ * Posix acl can be set using other xattr such as GF_POSIX_ACL_ACCESS/
+ * GF_POSIX_ACL_DEFAULT  which requires to update the context of
+ * access-control translator
+ */
+int
+handling_other_acl_related_xattr (xlator_t *this, inode_t *inode, dict_t *xattr)
+{
+        struct posix_acl       *acl      = NULL;
+        struct posix_acl_ctx   *ctx      = NULL;
+        data_t                 *data     = NULL;
+        int                     ret      = 0;
+
+        ctx = posix_acl_ctx_get (inode, this);
+        if (!ctx) {
+                ret = -1;
+                goto out;
+        }
+
+        data = dict_get (xattr, POSIX_ACL_ACCESS_XATTR);
+        if (data) {
+                ctx = posix_acl_ctx_get (inode, this);
+                if (!ctx) {
+                        ret = -1;
+                        goto out;
+                }
+
+                acl = posix_acl_from_xattr (this, data->data, data->len);
 
+                ret = posix_acl_set_specific (inode, this, acl, _gf_true);
+                if (ret)
+                        goto out;
+
+                if (acl)
+                        posix_acl_access_set_mode (acl, ctx);
+
+        }
+
+        if (acl)
+                posix_acl_unref (this, acl);
+
+        data = dict_get (xattr, POSIX_ACL_DEFAULT_XATTR);
+        if (data) {
+                acl = posix_acl_from_xattr (this, data->data, data->len);
+
+                ret = posix_acl_set_specific (inode, this, acl, _gf_false);
+        }
+
+out:
+        if (acl)
+                posix_acl_unref (this, acl);
+
+        return ret;
+}
 int
 posix_acl_setxattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                         int op_ret, int op_errno, dict_t *xdata)
 {
+
+        /*
+         * Update the context of posix_acl_translator, if any of
+         * POSIX_ACL_*_XATTR set in the call back
+         */
+        handling_other_acl_related_xattr (this, (inode_t *)cookie, xdata);
+
         STACK_UNWIND_STRICT (setxattr, frame, op_ret, op_errno, xdata);
 
         return 0;
@@ -1907,9 +2016,13 @@ posix_acl_setxattr (call_frame_t *frame, xlator_t *this, loc_t *loc,
 
         posix_acl_setxattr_update (this, loc->inode, xattr);
 
-        STACK_WIND (frame, posix_acl_setxattr_cbk,
-                    FIRST_CHILD(this), FIRST_CHILD(this)->fops->setxattr,
-                    loc, xattr, flags, xdata);
+        /*
+         * inode is required in call back function to update the context
+         * this translator
+         */
+        STACK_WIND_COOKIE (frame, posix_acl_setxattr_cbk, loc->inode,
+                           FIRST_CHILD(this), FIRST_CHILD(this)->fops->setxattr,
+                           loc, xattr, flags, xdata);
         return 0;
 red:
         STACK_UNWIND_STRICT (setxattr, frame, -1, op_errno, xdata);