Fix bug #7067 - Linux asynchronous IO (aio) can cause smbd to fail to respond to...
[amitay/samba.git] / source3 / smbd / notify.c
index 5c1143a28e2dbce448b1fc6f5d6a19f4e44417d3..0c75769594f6e350ebe7930df0b9edb3d35d684d 100644 (file)
@@ -7,7 +7,7 @@
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
+   the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "includes.h"
+#include "smbd/globals.h"
+
+struct notify_change_request {
+       struct notify_change_request *prev, *next;
+       struct files_struct *fsp;       /* backpointer for cancel by mid */
+       struct smb_request *req;
+       uint32 filter;
+       uint32 max_param;
+       void (*reply_fn)(struct smb_request *req,
+                        NTSTATUS error_code,
+                        uint8_t *buf, size_t len);
+       struct notify_mid_map *mid_map;
+       void *backend_data;
+};
 
-static struct notify_mid_map *notify_changes_by_mid;
+static void notify_fsp(files_struct *fsp, uint32 action, const char *name);
 
 /*
  * For NTCancel, we need to find the notify_change_request indexed by
@@ -35,23 +48,49 @@ struct notify_mid_map {
        uint16 mid;
 };
 
-static BOOL notify_marshall_changes(int num_changes,
-                                   struct notify_change *changes,
-                                   prs_struct *ps)
+static bool notify_change_record_identical(struct notify_change *c1,
+                                       struct notify_change *c2)
+{
+       /* Note this is deliberately case sensitive. */
+       if (c1->action == c2->action &&
+                       strcmp(c1->name, c2->name) == 0) {
+               return True;
+       }
+       return False;
+}
+
+static bool notify_marshall_changes(int num_changes,
+                               uint32 max_offset,
+                               struct notify_change *changes,
+                               prs_struct *ps)
 {
        int i;
        UNISTR uni_name;
 
+       if (num_changes == -1) {
+               return false;
+       }
+
+       uni_name.buffer = NULL;
+
        for (i=0; i<num_changes; i++) {
-               struct notify_change *c = &changes[i];
+               struct notify_change *c;
                size_t namelen;
                uint32 u32_tmp; /* Temp arg to prs_uint32 to avoid
                                 * signed/unsigned issues */
 
-               namelen = convert_string_allocate(
-                       NULL, CH_UNIX, CH_UTF16LE, c->name, strlen(c->name)+1,
-                       &uni_name.buffer, True);
-               if ((namelen == -1) || (uni_name.buffer == NULL)) {
+               /* Coalesce any identical records. */
+               while (i+1 < num_changes &&
+                       notify_change_record_identical(&changes[i],
+                                               &changes[i+1])) {
+                       i++;
+               }
+
+               c = &changes[i];
+
+               if (!convert_string_talloc(talloc_tos(), CH_UNIX, CH_UTF16LE,
+                       c->name, strlen(c->name)+1, &uni_name.buffer,
+                       &namelen, True) || (uni_name.buffer == NULL)) {
                        goto fail;
                }
 
@@ -77,13 +116,21 @@ static BOOL notify_marshall_changes(int num_changes,
                 */
                prs_set_offset(ps, prs_offset(ps)-2);
 
-               SAFE_FREE(uni_name.buffer);
+               TALLOC_FREE(uni_name.buffer);
+
+               if (prs_offset(ps) > max_offset) {
+                       /* Too much data for client. */
+                       DEBUG(10, ("Client only wanted %d bytes, trying to "
+                                  "marshall %d bytes\n", (int)max_offset,
+                                  (int)prs_offset(ps)));
+                       return False;
+               }
        }
 
        return True;
 
  fail:
-       SAFE_FREE(uni_name.buffer);
+       TALLOC_FREE(uni_name.buffer);
        return False;
 }
 
@@ -91,102 +138,128 @@ static BOOL notify_marshall_changes(int num_changes,
  Setup the common parts of the return packet and send it.
 *****************************************************************************/
 
-static void change_notify_reply_packet(const char *request_buf,
-                                      NTSTATUS error_code)
+void change_notify_reply(connection_struct *conn,
+                        struct smb_request *req,
+                        NTSTATUS error_code,
+                        uint32_t max_param,
+                        struct notify_change_buf *notify_buf,
+                        void (*reply_fn)(struct smb_request *req,
+                               NTSTATUS error_code,
+                               uint8_t *buf, size_t len))
 {
-       char outbuf[smb_size+38];
-
-       memset(outbuf, '\0', sizeof(outbuf));
-       construct_reply_common(request_buf, outbuf);
-
-       ERROR_NT(error_code);
-
-       /*
-        * Seems NT needs a transact command with an error code
-        * in it. This is a longer packet than a simple error.
-        */
-       set_message(outbuf,18,0,False);
-
-       show_msg(outbuf);
-       if (!send_smb(smbd_server_fd(),outbuf))
-               exit_server_cleanly("change_notify_reply_packet: send_smb "
-                                   "failed.");
-}
-
-void change_notify_reply(const char *request_buf, uint32 max_param_count,
-                        int num_changes, struct notify_change *changes)
-{
-       char *outbuf = NULL;
        prs_struct ps;
-       size_t buflen = smb_size+38+max_param_count;
 
-       if (num_changes == -1) {
-               change_notify_reply_packet(request_buf, NT_STATUS_OK);
+       if (!NT_STATUS_IS_OK(error_code)) {
+               reply_fn(req, error_code, NULL, 0);
                return;
        }
 
-       if (!prs_init(&ps, 0, NULL, False)
-           || !notify_marshall_changes(num_changes, changes, &ps)) {
-               change_notify_reply_packet(request_buf, NT_STATUS_NO_MEMORY);
-               goto done;
+       if (max_param == 0 || notify_buf == NULL) {
+               reply_fn(req, NT_STATUS_OK, NULL, 0);
+               return;
        }
 
-       if (prs_offset(&ps) > max_param_count) {
+       prs_init_empty(&ps, NULL, MARSHALL);
+
+       if (!notify_marshall_changes(notify_buf->num_changes, max_param,
+                                       notify_buf->changes, &ps)) {
                /*
                 * We exceed what the client is willing to accept. Send
                 * nothing.
                 */
-               change_notify_reply_packet(request_buf, NT_STATUS_OK);
-               goto done;
+               prs_mem_free(&ps);
+               prs_init_empty(&ps, NULL, MARSHALL);
        }
 
-       if (!(outbuf = SMB_MALLOC_ARRAY(char, buflen))) {
-               change_notify_reply_packet(request_buf, NT_STATUS_NO_MEMORY);
-               goto done;
+       reply_fn(req, NT_STATUS_OK, (uint8_t *)prs_data_p(&ps), prs_offset(&ps));
+
+       prs_mem_free(&ps);
+
+       TALLOC_FREE(notify_buf->changes);
+       notify_buf->num_changes = 0;
+}
+
+static void notify_callback(void *private_data, const struct notify_event *e)
+{
+       files_struct *fsp = (files_struct *)private_data;
+       DEBUG(10, ("notify_callback called for %s\n", fsp_str_dbg(fsp)));
+       notify_fsp(fsp, e->action, e->path);
+}
+
+NTSTATUS change_notify_create(struct files_struct *fsp, uint32 filter,
+                             bool recursive)
+{
+       char *fullpath;
+       struct notify_entry e;
+       NTSTATUS status;
+
+       SMB_ASSERT(fsp->notify == NULL);
+
+       if (!(fsp->notify = TALLOC_ZERO_P(NULL, struct notify_change_buf))) {
+               DEBUG(0, ("talloc failed\n"));
+               return NT_STATUS_NO_MEMORY;
        }
 
-       construct_reply_common(request_buf, outbuf);
+       /* Do notify operations on the base_name. */
+       if (asprintf(&fullpath, "%s/%s", fsp->conn->connectpath,
+                    fsp->fsp_name->base_name) == -1) {
+               DEBUG(0, ("asprintf failed\n"));
+               TALLOC_FREE(fsp->notify);
+               return NT_STATUS_NO_MEMORY;
+       }
 
-       if (send_nt_replies(outbuf, buflen, NT_STATUS_OK, prs_data_p(&ps),
-                           prs_offset(&ps), NULL, 0) == -1) {
-               exit_server("change_notify_reply_packet: send_smb failed.");
+       ZERO_STRUCT(e);
+       e.path = fullpath;
+       e.dir_fd = fsp->fh->fd;
+       e.dir_id = fsp->file_id;
+       e.filter = filter;
+       e.subdir_filter = 0;
+       if (recursive) {
+               e.subdir_filter = filter;
        }
 
- done:
-       SAFE_FREE(outbuf);
-       prs_mem_free(&ps);
+       status = notify_add(fsp->conn->notify_ctx, &e, notify_callback, fsp);
+       SAFE_FREE(fullpath);
+
+       return status;
 }
 
-NTSTATUS change_notify_add_request(const char *inbuf, uint32 max_param_count,
-                                  uint32 filter, BOOL recursive,
-                                  struct files_struct *fsp)
+NTSTATUS change_notify_add_request(struct smb_request *req,
+                               uint32 max_param,
+                               uint32 filter, bool recursive,
+                               struct files_struct *fsp,
+                               void (*reply_fn)(struct smb_request *req,
+                                       NTSTATUS error_code,
+                                       uint8_t *buf, size_t len))
 {
        struct notify_change_request *request = NULL;
        struct notify_mid_map *map = NULL;
+       struct smbd_server_connection *sconn = smbd_server_conn;
+
+       DEBUG(10, ("change_notify_add_request: Adding request for %s: "
+                  "max_param = %d\n", fsp_str_dbg(fsp), (int)max_param));
 
-       if (!(request = SMB_MALLOC_P(struct notify_change_request))
-           || !(map = SMB_MALLOC_P(struct notify_mid_map))) {
-               SAFE_FREE(request);
+       if (!(request = talloc(NULL, struct notify_change_request))
+           || !(map = talloc(request, struct notify_mid_map))) {
+               TALLOC_FREE(request);
                return NT_STATUS_NO_MEMORY;
        }
 
        request->mid_map = map;
        map->req = request;
 
-       memcpy(request->request_buf, inbuf, sizeof(request->request_buf));
-       request->max_param_count = max_param_count;
+       request->req = talloc_move(request, &req);
+       request->max_param = max_param;
        request->filter = filter;
        request->fsp = fsp;
+       request->reply_fn = reply_fn;
        request->backend_data = NULL;
-       
+
        DLIST_ADD_END(fsp->notify->requests, request,
                      struct notify_change_request *);
 
-       map->mid = SVAL(inbuf, smb_mid);
-       DLIST_ADD(notify_changes_by_mid, map);
-
-       /* Push the MID of this packet on the signing queue. */
-       srv_defer_sign_response(SVAL(inbuf,smb_mid));
+       map->mid = request->req->mid;
+       DLIST_ADD(sconn->smb1.notify_mid_maps, map);
 
        return NT_STATUS_OK;
 }
@@ -195,6 +268,7 @@ static void change_notify_remove_request(struct notify_change_request *remove_re
 {
        files_struct *fsp;
        struct notify_change_request *req;
+       struct smbd_server_connection *sconn = smbd_server_conn;
 
        /*
         * Paranoia checks, the fsp referenced must must have the request in
@@ -211,14 +285,12 @@ static void change_notify_remove_request(struct notify_change_request *remove_re
        }
 
        if (req == NULL) {
-               smb_panic("notify_req not found in fsp's requests\n");
+               smb_panic("notify_req not found in fsp's requests");
        }
 
        DLIST_REMOVE(fsp->notify->requests, req);
-       DLIST_REMOVE(notify_changes_by_mid, req->mid_map);
-       SAFE_FREE(req->mid_map);
-       TALLOC_FREE(req->backend_data);
-       SAFE_FREE(req);
+       DLIST_REMOVE(sconn->smb1.notify_mid_maps, req->mid_map);
+       TALLOC_FREE(req);
 }
 
 /****************************************************************************
@@ -228,8 +300,9 @@ static void change_notify_remove_request(struct notify_change_request *remove_re
 void remove_pending_change_notify_requests_by_mid(uint16 mid)
 {
        struct notify_mid_map *map;
+       struct smbd_server_connection *sconn = smbd_server_conn;
 
-       for (map = notify_changes_by_mid; map; map = map->next) {
+       for (map = sconn->smb1.notify_mid_maps; map; map = map->next) {
                if (map->mid == mid) {
                        break;
                }
@@ -239,7 +312,28 @@ void remove_pending_change_notify_requests_by_mid(uint16 mid)
                return;
        }
 
-       change_notify_reply_packet(map->req->request_buf, NT_STATUS_CANCELLED);
+       change_notify_reply(map->req->fsp->conn, map->req->req,
+                           NT_STATUS_CANCELLED, 0, NULL, map->req->reply_fn);
+       change_notify_remove_request(map->req);
+}
+
+void smbd_notify_cancel_by_smbreq(struct smbd_server_connection *sconn,
+                                 const struct smb_request *smbreq)
+{
+       struct notify_mid_map *map;
+
+       for (map = sconn->smb1.notify_mid_maps; map; map = map->next) {
+               if (map->req->req == smbreq) {
+                       break;
+               }
+       }
+
+       if (map == NULL) {
+               return;
+       }
+
+       change_notify_reply(map->req->fsp->conn, map->req->req,
+                           NT_STATUS_CANCELLED, 0, NULL, map->req->reply_fn);
        change_notify_remove_request(map->req);
 }
 
@@ -255,8 +349,9 @@ void remove_pending_change_notify_requests_by_fid(files_struct *fsp,
        }
 
        while (fsp->notify->requests != NULL) {
-               change_notify_reply_packet(
-                       fsp->notify->requests->request_buf, status);
+               change_notify_reply(fsp->conn, fsp->notify->requests->req,
+                                   status, 0, NULL,
+                                   fsp->notify->requests->reply_fn);
                change_notify_remove_request(fsp->notify->requests);
        }
 }
@@ -265,20 +360,39 @@ void notify_fname(connection_struct *conn, uint32 action, uint32 filter,
                  const char *path)
 {
        char *fullpath;
+       char *parent;
+       const char *name;
 
-       if (asprintf(&fullpath, "%s/%s", conn->connectpath, path) == -1) {
+       if (path[0] == '.' && path[1] == '/') {
+               path += 2;
+       }
+       if (parent_dirname(talloc_tos(), path, &parent, &name)) {
+               struct smb_filename smb_fname_parent;
+
+               ZERO_STRUCT(smb_fname_parent);
+               smb_fname_parent.base_name = parent;
+
+               if (SMB_VFS_STAT(conn, &smb_fname_parent) != -1) {
+                       notify_onelevel(conn->notify_ctx, action, filter,
+                           SMB_VFS_FILE_ID_CREATE(conn, &smb_fname_parent.st),
+                           name);
+               }
+       }
+
+       fullpath = talloc_asprintf(talloc_tos(), "%s/%s", conn->connectpath,
+                                  path);
+       if (fullpath == NULL) {
                DEBUG(0, ("asprintf failed\n"));
                return;
        }
-
        notify_trigger(conn->notify_ctx, action, filter, fullpath);
-       SAFE_FREE(fullpath);
+       TALLOC_FREE(fullpath);
 }
 
-void notify_fsp(files_struct *fsp, uint32 action, const char *name)
+static void notify_fsp(files_struct *fsp, uint32 action, const char *name)
 {
        struct notify_change *change, *changes;
-       char *name2;
+       char *tmp;
 
        if (fsp->notify == NULL) {
                /*
@@ -287,29 +401,36 @@ void notify_fsp(files_struct *fsp, uint32 action, const char *name)
                return;
        }
 
-       if (!(name2 = talloc_strdup(fsp->notify, name))) {
-               DEBUG(0, ("talloc_strdup failed\n"));
-                       return;
-               }
-
-       string_replace(name2, '/', '\\');
-
        /*
         * Someone has triggered a notify previously, queue the change for
-        * later. TODO: Limit the number of changes queued, test how filters
-        * apply here. Do we have to store them?
+        * later.
         */
 
-       if ((fsp->notify->num_changes > 30) || (name == NULL)) {
+       if ((fsp->notify->num_changes > 1000) || (name == NULL)) {
                /*
-                * W2k3 seems to store at most 30 changes.
+                * The real number depends on the client buf, just provide a
+                * guard against a DoS here.  If name == NULL the CN backend is
+                * alerting us to a problem.  Possibly dropped events.  Clear
+                * queued changes and send the catch-all response to the client
+                * if a request is pending.
                 */
                TALLOC_FREE(fsp->notify->changes);
-               TALLOC_FREE(name2);
                fsp->notify->num_changes = -1;
+               if (fsp->notify->requests != NULL) {
+                       change_notify_reply(fsp->conn,
+                                           fsp->notify->requests->req,
+                                           NT_STATUS_OK,
+                                           fsp->notify->requests->max_param,
+                                           fsp->notify,
+                                           fsp->notify->requests->reply_fn);
+                       change_notify_remove_request(fsp->notify->requests);
+               }
                return;
        }
 
+       /* If we've exceeded the server side queue or received a NULL name
+        * from the underlying CN implementation, don't queue up any more
+        * requests until we can send a catch-all response to the client */
        if (fsp->notify->num_changes == -1) {
                return;
        }
@@ -318,7 +439,6 @@ void notify_fsp(files_struct *fsp, uint32 action, const char *name)
                      fsp->notify, fsp->notify->changes,
                      struct notify_change, fsp->notify->num_changes+1))) {
                DEBUG(0, ("talloc_realloc failed\n"));
-               TALLOC_FREE(name2);
                return;
        }
 
@@ -326,7 +446,14 @@ void notify_fsp(files_struct *fsp, uint32 action, const char *name)
 
        change = &(fsp->notify->changes[fsp->notify->num_changes]);
 
-       change->name = talloc_move(changes, &name2);
+       if (!(tmp = talloc_strdup(changes, name))) {
+               DEBUG(0, ("talloc_strdup failed\n"));
+               return;
+       }
+
+       string_replace(tmp, '/', '\\');
+       change->name = tmp;     
+
        change->action = action;
        fsp->notify->num_changes += 1;
 
@@ -342,7 +469,7 @@ void notify_fsp(files_struct *fsp, uint32 action, const char *name)
                 * We have to send the two rename events in one reply. So hold
                 * the first part back.
                 */
-       return;
+               return;
        }
 
        /*
@@ -351,15 +478,14 @@ void notify_fsp(files_struct *fsp, uint32 action, const char *name)
         * TODO: do we have to walk the lists of requests pending?
         */
 
-       change_notify_reply(fsp->notify->requests->request_buf,
-                           fsp->notify->requests->max_param_count,
-                           fsp->notify->num_changes,
-                           fsp->notify->changes);
+       change_notify_reply(fsp->conn,
+                           fsp->notify->requests->req,
+                           NT_STATUS_OK,
+                           fsp->notify->requests->max_param,
+                           fsp->notify,
+                           fsp->notify->requests->reply_fn);
 
        change_notify_remove_request(fsp->notify->requests);
-
-       TALLOC_FREE(fsp->notify->changes);
-       fsp->notify->num_changes = 0;
 }
 
 char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32 filter)
@@ -400,7 +526,7 @@ char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32 filter)
        return result;
 }
 
-struct sys_notify_context *sys_notify_context_create(struct share_params *scfg,
+struct sys_notify_context *sys_notify_context_create(connection_struct *conn,
                                                     TALLOC_CTX *mem_ctx, 
                                                     struct event_context *ev)
 {
@@ -412,6 +538,7 @@ struct sys_notify_context *sys_notify_context_create(struct share_params *scfg,
        }
 
        ctx->ev = ev;
+       ctx->conn = conn;
        ctx->private_data = NULL;
        return ctx;
 }
@@ -423,10 +550,7 @@ NTSTATUS sys_notify_watch(struct sys_notify_context *ctx,
                                           struct notify_event *ev),
                          void *private_data, void *handle)
 {
-#ifdef HAVE_INOTIFY
-       return inotify_watch(ctx, e, callback, private_data, handle);
-#else
-       return NT_STATUS_OK;
-#endif
+       return SMB_VFS_NOTIFY_WATCH(ctx->conn, ctx, e, callback, private_data,
+                                   handle);
 }