s3:smbd: add lease related helper functions to open.c

Pair-Programmed-With: Jeremy Allison <jra@samba.org>
Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

Signed-off-by: Volker Lendecke <vl@samba.org>
Signed-off-by: Jeremy Allison <jra@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>

diff --git a/source3/smbd/open.c b/source3/smbd/open.c
index c14d2ebf59bfd67307bc7a5473d91c09c809658d..1055c94b47ee69ee4758535b150ed040ef9dc6b6 100644 (file)
--- a/source3/smbd/open.c
+++ b/source3/smbd/open.c
@@ -35,6 +35,7 @@
 #include "serverid.h"
 #include "messages.h"
 #include "source3/lib/dbwrap/dbwrap_watch.h"
+#include "locking/leases_db.h"
 
 extern const struct generic_mapping file_generic_mapping;
 
@@ -1490,6 +1491,213 @@ static bool file_has_brlocks(files_struct *fsp)
        return (brl_num_locks(br_lck) > 0);
 }
 
+int find_share_mode_lease(struct share_mode_data *d,
+                         const struct GUID *client_guid,
+                         const struct smb2_lease_key *key)
+{
+       uint32_t i;
+
+       for (i=0; i<d->num_leases; i++) {
+               struct share_mode_lease *l = &d->leases[i];
+
+               if (smb2_lease_equal(client_guid,
+                                    key,
+                                    &l->client_guid,
+                                    &l->lease_key)) {
+                       return i;
+               }
+       }
+
+       return -1;
+}
+
+struct fsp_lease *find_fsp_lease(struct files_struct *new_fsp,
+                                const struct smb2_lease_key *key,
+                                const struct share_mode_lease *l)
+{
+       struct files_struct *fsp;
+
+       /*
+        * TODO: Measure how expensive this loop is with thousands of open
+        * handles...
+        */
+
+       for (fsp = file_find_di_first(new_fsp->conn->sconn, new_fsp->file_id);
+            fsp != NULL;
+            fsp = file_find_di_next(fsp)) {
+
+               if (fsp == new_fsp) {
+                       continue;
+               }
+               if (fsp->oplock_type != LEASE_OPLOCK) {
+                       continue;
+               }
+               if (smb2_lease_key_equal(&fsp->lease->lease.lease_key, key)) {
+                       fsp->lease->ref_count += 1;
+                       return fsp->lease;
+               }
+       }
+
+       /* Not found - must be leased in another smbd. */
+       new_fsp->lease = talloc_zero(new_fsp->conn->sconn, struct fsp_lease);
+       if (new_fsp->lease == NULL) {
+               return NULL;
+       }
+       new_fsp->lease->ref_count = 1;
+       new_fsp->lease->sconn = new_fsp->conn->sconn;
+       new_fsp->lease->lease.lease_key = *key;
+       new_fsp->lease->lease.lease_state = l->current_state;
+       /*
+        * We internally treat all leases as V2 and update
+        * the epoch, but when sending breaks it matters if
+        * the requesting lease was v1 or v2.
+        */
+       new_fsp->lease->lease.lease_version = l->lease_version;
+       new_fsp->lease->lease.lease_epoch = l->epoch;
+       return new_fsp->lease;
+}
+
+#if 0
+static NTSTATUS grant_fsp_lease(struct files_struct *fsp,
+                               struct share_mode_lock *lck,
+                               const struct smb2_lease *lease,
+                               uint32_t *p_lease_idx,
+                               uint32_t granted)
+{
+       struct share_mode_data *d = lck->data;
+       const struct GUID *client_guid = fsp_client_guid(fsp);
+       struct share_mode_lease *tmp;
+       NTSTATUS status;
+       int idx;
+
+       idx = find_share_mode_lease(d, client_guid, &lease->lease_key);
+
+       if (idx != -1) {
+               struct share_mode_lease *l = &d->leases[idx];
+               bool do_upgrade;
+               uint32_t existing, requested;
+
+               fsp->lease = find_fsp_lease(fsp, &lease->lease_key, l);
+               if (fsp->lease == NULL) {
+                       DEBUG(1, ("Did not find existing lease for file %s\n",
+                                 fsp_str_dbg(fsp)));
+                       return NT_STATUS_NO_MEMORY;
+               }
+
+               *p_lease_idx = idx;
+
+               /*
+                * Upgrade only if the requested lease is a strict upgrade.
+                */
+               existing = l->current_state;
+               requested = lease->lease_state;
+
+               /*
+                * Tricky: This test makes sure that "requested" is a
+                * strict bitwise superset of "existing".
+                */
+               do_upgrade = ((existing & requested) == existing);
+
+               /*
+                * Upgrade only if there's a change.
+                */
+               do_upgrade &= (granted != existing);
+
+               /*
+                * Upgrade only if other leases don't prevent what was asked
+                * for.
+                */
+               do_upgrade &= (granted == requested);
+
+               /*
+                * only upgrade if we are not in breaking state
+                */
+               do_upgrade &= !l->breaking;
+
+               DEBUG(10, ("existing=%"PRIu32", requested=%"PRIu32", "
+                          "granted=%"PRIu32", do_upgrade=%d\n",
+                          existing, requested, granted, (int)do_upgrade));
+
+               if (do_upgrade) {
+                       l->current_state = granted;
+                       l->epoch += 1;
+               }
+
+               /* Ensure we're in sync with current lease state. */
+               fsp_lease_update(lck, fsp_client_guid(fsp), fsp->lease);
+               return NT_STATUS_OK;
+       }
+
+       /*
+        * Create new lease
+        */
+
+       tmp = talloc_realloc(d, d->leases, struct share_mode_lease,
+                            d->num_leases+1);
+       if (tmp == NULL) {
+               /*
+                * See [MS-SMB2]
+                */
+               return NT_STATUS_INSUFFICIENT_RESOURCES;
+       }
+       d->leases = tmp;
+
+       fsp->lease = talloc_zero(fsp->conn->sconn, struct fsp_lease);
+       if (fsp->lease == NULL) {
+               return NT_STATUS_INSUFFICIENT_RESOURCES;
+       }
+       fsp->lease->ref_count = 1;
+       fsp->lease->sconn = fsp->conn->sconn;
+       fsp->lease->lease.lease_version = lease->lease_version;
+       fsp->lease->lease.lease_key = lease->lease_key;
+       fsp->lease->lease.lease_state = granted;
+       fsp->lease->lease.lease_epoch = lease->lease_epoch + 1;
+
+       *p_lease_idx = d->num_leases;
+
+       d->leases[d->num_leases] = (struct share_mode_lease) {
+               .client_guid = *client_guid,
+               .lease_key = fsp->lease->lease.lease_key,
+               .current_state = fsp->lease->lease.lease_state,
+               .lease_version = fsp->lease->lease.lease_version,
+               .epoch = fsp->lease->lease.lease_epoch,
+       };
+
+       status = leases_db_add(client_guid, &lease->lease_key,
+                              &fsp->file_id, fsp->fsp_name->base_name,
+                              fsp->fsp_name->stream_name);
+       if (!NT_STATUS_IS_OK(status)) {
+               DEBUG(10, ("%s: leases_db_add failed: %s\n", __func__,
+                          nt_errstr(status)));
+               TALLOC_FREE(fsp->lease);
+               return NT_STATUS_INSUFFICIENT_RESOURCES;
+       }
+
+       d->num_leases += 1;
+       d->modified = true;
+
+       return NT_STATUS_OK;
+}
+
+static bool is_same_lease(const files_struct *fsp,
+                         const struct share_mode_data *d,
+                         const struct share_mode_entry *e,
+                         const struct smb2_lease *lease)
+{
+       if (e->op_type != LEASE_OPLOCK) {
+               return false;
+       }
+       if (lease == NULL) {
+               return false;
+       }
+
+       return smb2_lease_equal(fsp_client_guid(fsp),
+                               &lease->lease_key,
+                               &d->leases[e->lease_idx].client_guid,
+                               &d->leases[e->lease_idx].lease_key);
+}
+#endif
+
 static NTSTATUS grant_fsp_oplock_type(struct smb_request *req,
                                      struct files_struct *fsp,
                                      struct share_mode_lock *lck,

diff --git a/source3/smbd/proto.h b/source3/smbd/proto.h
index 7a4b4c972c10a17d08295bde2060c2def2f21391..55fbd3bfac7df558499776fd091f7f6a8d930244 100644 (file)
--- a/source3/smbd/proto.h
+++ b/source3/smbd/proto.h
@@ -626,6 +626,13 @@ void msg_file_was_renamed(struct messaging_context *msg,
                          DATA_BLOB *data);
 NTSTATUS open_streams_for_delete(connection_struct *conn,
                                 const char *fname);
+int find_share_mode_lease(struct share_mode_data *d,
+                         const struct GUID *client_guid,
+                         const struct smb2_lease_key *key);
+struct share_mode_lease;
+struct fsp_lease *find_fsp_lease(files_struct *new_fsp,
+                                const struct smb2_lease_key *key,
+                                const struct share_mode_lease *l);
 NTSTATUS create_file_default(connection_struct *conn,
                             struct smb_request *req,
                             uint16_t root_dir_fid,