messaging3: Introduce messaging_local_backend()
[samba.git] / source3 / lib / messages.c
index f4d62279d935cedbb328dc7d941b685b6169d3a8..db7257dba54fd7ff8803046343ddaaa023725215 100644 (file)
@@ -49,6 +49,8 @@
 #include "dbwrap/dbwrap.h"
 #include "serverid.h"
 #include "messages.h"
+#include "lib/util/tevent_unix.h"
+#include "lib/background.h"
 
 struct messaging_callback {
        struct messaging_callback *prev, *next;
@@ -196,16 +198,15 @@ struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx,
        ctx->id = procid_self();
        ctx->event_ctx = ev;
 
-       status = messaging_tdb_init(ctx, ctx, &ctx->local);
+       status = messaging_dgm_init(ctx, ctx, &ctx->local);
 
        if (!NT_STATUS_IS_OK(status)) {
-               DEBUG(2, ("messaging_tdb_init failed: %s\n",
+               DEBUG(2, ("messaging_dgm_init failed: %s\n",
                          nt_errstr(status)));
                TALLOC_FREE(ctx);
                return NULL;
        }
 
-#ifdef CLUSTER_SUPPORT
        if (lp_clustering()) {
                status = messaging_ctdbd_init(ctx, ctx, &ctx->remote);
 
@@ -217,7 +218,6 @@ struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx,
                }
        }
        ctx->id.vnn = get_my_vnn();
-#endif
 
        messaging_register(ctx, NULL, MSG_PING, ping_message);
 
@@ -246,14 +246,13 @@ NTSTATUS messaging_reinit(struct messaging_context *msg_ctx)
 
        msg_ctx->id = procid_self();
 
-       status = messaging_tdb_init(msg_ctx, msg_ctx, &msg_ctx->local);
+       status = messaging_dgm_init(msg_ctx, msg_ctx, &msg_ctx->local);
        if (!NT_STATUS_IS_OK(status)) {
-               DEBUG(0, ("messaging_tdb_init failed: %s\n",
+               DEBUG(0, ("messaging_dgm_init failed: %s\n",
                          nt_errstr(status)));
                return status;
        }
 
-#ifdef CLUSTER_SUPPORT
        TALLOC_FREE(msg_ctx->remote);
 
        if (lp_clustering()) {
@@ -267,8 +266,6 @@ NTSTATUS messaging_reinit(struct messaging_context *msg_ctx)
                }
        }
 
-#endif
-
        return NT_STATUS_OK;
 }
 
@@ -344,34 +341,394 @@ void messaging_deregister(struct messaging_context *ctx, uint32_t msg_type,
        }
 }
 
+static bool messaging_is_self_send(const struct messaging_context *msg_ctx,
+                                  const struct server_id *dst)
+{
+       return ((msg_ctx->id.vnn == dst->vnn) &&
+               (msg_ctx->id.pid == dst->pid));
+}
+
 /*
   Send a message to a particular server
 */
 NTSTATUS messaging_send(struct messaging_context *msg_ctx,
                        struct server_id server, uint32_t msg_type,
                        const DATA_BLOB *data)
+{
+       struct iovec iov;
+
+       iov.iov_base = data->data;
+       iov.iov_len = data->length;
+
+       return messaging_send_iov(msg_ctx, server, msg_type, &iov, 1);
+}
+
+NTSTATUS messaging_send_buf(struct messaging_context *msg_ctx,
+                           struct server_id server, uint32_t msg_type,
+                           const uint8_t *buf, size_t len)
+{
+       DATA_BLOB blob = data_blob_const(buf, len);
+       return messaging_send(msg_ctx, server, msg_type, &blob);
+}
+
+NTSTATUS messaging_send_iov(struct messaging_context *msg_ctx,
+                           struct server_id server, uint32_t msg_type,
+                           const struct iovec *iov, int iovlen)
 {
        if (server_id_is_disconnected(&server)) {
                return NT_STATUS_INVALID_PARAMETER_MIX;
        }
 
-#ifdef CLUSTER_SUPPORT
        if (!procid_is_local(&server)) {
-               return msg_ctx->remote->send_fn(msg_ctx, server,
-                                               msg_type, data,
+               return msg_ctx->remote->send_fn(msg_ctx->id, server,
+                                               msg_type, iov, iovlen,
                                                msg_ctx->remote);
        }
-#endif
-       return msg_ctx->local->send_fn(msg_ctx, server, msg_type, data,
-                                      msg_ctx->local);
+
+       if (messaging_is_self_send(msg_ctx, &server)) {
+               struct messaging_rec rec;
+               uint8_t *buf;
+               DATA_BLOB data;
+
+               buf = iov_buf(talloc_tos(), iov, iovlen);
+               if (buf == NULL) {
+                       return NT_STATUS_NO_MEMORY;
+               }
+
+               data = data_blob_const(buf, talloc_get_size(buf));
+
+               rec.msg_version = MESSAGE_VERSION;
+               rec.msg_type = msg_type & MSG_TYPE_MASK;
+               rec.dest = server;
+               rec.src = msg_ctx->id;
+               rec.buf = data;
+               messaging_dispatch_rec(msg_ctx, &rec);
+               TALLOC_FREE(buf);
+               return NT_STATUS_OK;
+       }
+
+       return msg_ctx->local->send_fn(msg_ctx->id, server, msg_type,
+                                      iov, iovlen, msg_ctx->local);
 }
 
-NTSTATUS messaging_send_buf(struct messaging_context *msg_ctx,
-                           struct server_id server, uint32_t msg_type,
-                           const uint8_t *buf, size_t len)
+static struct messaging_rec *messaging_rec_dup(TALLOC_CTX *mem_ctx,
+                                              struct messaging_rec *rec)
 {
-       DATA_BLOB blob = data_blob_const(buf, len);
-       return messaging_send(msg_ctx, server, msg_type, &blob);
+       struct messaging_rec *result;
+
+       result = talloc_pooled_object(mem_ctx, struct messaging_rec,
+                                     1, rec->buf.length);
+       if (result == NULL) {
+               return NULL;
+       }
+       *result = *rec;
+
+       /* Doesn't fail, see talloc_pooled_object */
+
+       result->buf.data = talloc_memdup(result, rec->buf.data,
+                                        rec->buf.length);
+       return result;
+}
+
+struct messaging_filtered_read_state {
+       struct tevent_context *ev;
+       struct messaging_context *msg_ctx;
+       void *tevent_handle;
+
+       bool (*filter)(struct messaging_rec *rec, void *private_data);
+       void *private_data;
+
+       struct messaging_rec *rec;
+};
+
+static void messaging_filtered_read_cleanup(struct tevent_req *req,
+                                           enum tevent_req_state req_state);
+
+struct tevent_req *messaging_filtered_read_send(
+       TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+       struct messaging_context *msg_ctx,
+       bool (*filter)(struct messaging_rec *rec, void *private_data),
+       void *private_data)
+{
+       struct tevent_req *req;
+       struct messaging_filtered_read_state *state;
+       size_t new_waiters_len;
+
+       req = tevent_req_create(mem_ctx, &state,
+                               struct messaging_filtered_read_state);
+       if (req == NULL) {
+               return NULL;
+       }
+       state->ev = ev;
+       state->msg_ctx = msg_ctx;
+       state->filter = filter;
+       state->private_data = private_data;
+
+       /*
+        * We have to defer the callback here, as we might be called from
+        * within a different tevent_context than state->ev
+        */
+       tevent_req_defer_callback(req, state->ev);
+
+       state->tevent_handle = messaging_dgm_register_tevent_context(
+               state, msg_ctx, ev);
+       if (tevent_req_nomem(state, req)) {
+               return tevent_req_post(req, ev);
+       }
+
+       /*
+        * We add ourselves to the "new_waiters" array, not the "waiters"
+        * array. If we are called from within messaging_read_done,
+        * messaging_dispatch_rec will be in an active for-loop on
+        * "waiters". We must be careful not to mess with this array, because
+        * it could mean that a single event is being delivered twice.
+        */
+
+       new_waiters_len = talloc_array_length(msg_ctx->new_waiters);
+
+       if (new_waiters_len == msg_ctx->num_new_waiters) {
+               struct tevent_req **tmp;
+
+               tmp = talloc_realloc(msg_ctx, msg_ctx->new_waiters,
+                                    struct tevent_req *, new_waiters_len+1);
+               if (tevent_req_nomem(tmp, req)) {
+                       return tevent_req_post(req, ev);
+               }
+               msg_ctx->new_waiters = tmp;
+       }
+
+       msg_ctx->new_waiters[msg_ctx->num_new_waiters] = req;
+       msg_ctx->num_new_waiters += 1;
+       tevent_req_set_cleanup_fn(req, messaging_filtered_read_cleanup);
+
+       return req;
+}
+
+static void messaging_filtered_read_cleanup(struct tevent_req *req,
+                                           enum tevent_req_state req_state)
+{
+       struct messaging_filtered_read_state *state = tevent_req_data(
+               req, struct messaging_filtered_read_state);
+       struct messaging_context *msg_ctx = state->msg_ctx;
+       unsigned i;
+
+       tevent_req_set_cleanup_fn(req, NULL);
+
+       TALLOC_FREE(state->tevent_handle);
+
+       /*
+        * Just set the [new_]waiters entry to NULL, be careful not to mess
+        * with the other "waiters" array contents. We are often called from
+        * within "messaging_dispatch_rec", which loops over
+        * "waiters". Messing with the "waiters" array will mess up that
+        * for-loop.
+        */
+
+       for (i=0; i<msg_ctx->num_waiters; i++) {
+               if (msg_ctx->waiters[i] == req) {
+                       msg_ctx->waiters[i] = NULL;
+                       return;
+               }
+       }
+
+       for (i=0; i<msg_ctx->num_new_waiters; i++) {
+               if (msg_ctx->new_waiters[i] == req) {
+                       msg_ctx->new_waiters[i] = NULL;
+                       return;
+               }
+       }
+}
+
+static void messaging_filtered_read_done(struct tevent_req *req,
+                                        struct messaging_rec *rec)
+{
+       struct messaging_filtered_read_state *state = tevent_req_data(
+               req, struct messaging_filtered_read_state);
+
+       state->rec = messaging_rec_dup(state, rec);
+       if (tevent_req_nomem(state->rec, req)) {
+               return;
+       }
+       tevent_req_done(req);
+}
+
+int messaging_filtered_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
+                                struct messaging_rec **presult)
+{
+       struct messaging_filtered_read_state *state = tevent_req_data(
+               req, struct messaging_filtered_read_state);
+       int err;
+
+       if (tevent_req_is_unix_error(req, &err)) {
+               tevent_req_received(req);
+               return err;
+       }
+       *presult = talloc_move(mem_ctx, &state->rec);
+       return 0;
+}
+
+struct messaging_read_state {
+       uint32_t msg_type;
+       struct messaging_rec *rec;
+};
+
+static bool messaging_read_filter(struct messaging_rec *rec,
+                                 void *private_data);
+static void messaging_read_done(struct tevent_req *subreq);
+
+struct tevent_req *messaging_read_send(TALLOC_CTX *mem_ctx,
+                                      struct tevent_context *ev,
+                                      struct messaging_context *msg,
+                                      uint32_t msg_type)
+{
+       struct tevent_req *req, *subreq;
+       struct messaging_read_state *state;
+
+       req = tevent_req_create(mem_ctx, &state,
+                               struct messaging_read_state);
+       if (req == NULL) {
+               return NULL;
+       }
+       state->msg_type = msg_type;
+
+       subreq = messaging_filtered_read_send(state, ev, msg,
+                                             messaging_read_filter, state);
+       if (tevent_req_nomem(subreq, req)) {
+               return tevent_req_post(req, ev);
+       }
+       tevent_req_set_callback(subreq, messaging_read_done, req);
+       return req;
+}
+
+static bool messaging_read_filter(struct messaging_rec *rec,
+                                 void *private_data)
+{
+       struct messaging_read_state *state = talloc_get_type_abort(
+               private_data, struct messaging_read_state);
+
+       return rec->msg_type == state->msg_type;
+}
+
+static void messaging_read_done(struct tevent_req *subreq)
+{
+       struct tevent_req *req = tevent_req_callback_data(
+               subreq, struct tevent_req);
+       struct messaging_read_state *state = tevent_req_data(
+               req, struct messaging_read_state);
+       int ret;
+
+       ret = messaging_filtered_read_recv(subreq, state, &state->rec);
+       TALLOC_FREE(subreq);
+       if (tevent_req_error(req, ret)) {
+               return;
+       }
+       tevent_req_done(req);
+}
+
+int messaging_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
+                       struct messaging_rec **presult)
+{
+       struct messaging_read_state *state = tevent_req_data(
+               req, struct messaging_read_state);
+       int err;
+
+       if (tevent_req_is_unix_error(req, &err)) {
+               return err;
+       }
+       if (presult != NULL) {
+               *presult = talloc_move(mem_ctx, &state->rec);
+       }
+       return 0;
+}
+
+static bool messaging_append_new_waiters(struct messaging_context *msg_ctx)
+{
+       if (msg_ctx->num_new_waiters == 0) {
+               return true;
+       }
+
+       if (talloc_array_length(msg_ctx->waiters) <
+           (msg_ctx->num_waiters + msg_ctx->num_new_waiters)) {
+               struct tevent_req **tmp;
+               tmp = talloc_realloc(
+                       msg_ctx, msg_ctx->waiters, struct tevent_req *,
+                       msg_ctx->num_waiters + msg_ctx->num_new_waiters);
+               if (tmp == NULL) {
+                       DEBUG(1, ("%s: talloc failed\n", __func__));
+                       return false;
+               }
+               msg_ctx->waiters = tmp;
+       }
+
+       memcpy(&msg_ctx->waiters[msg_ctx->num_waiters], msg_ctx->new_waiters,
+              sizeof(struct tevent_req *) * msg_ctx->num_new_waiters);
+
+       msg_ctx->num_waiters += msg_ctx->num_new_waiters;
+       msg_ctx->num_new_waiters = 0;
+
+       return true;
+}
+
+struct messaging_defer_callback_state {
+       struct messaging_context *msg_ctx;
+       struct messaging_rec *rec;
+       void (*fn)(struct messaging_context *msg, void *private_data,
+                  uint32_t msg_type, struct server_id server_id,
+                  DATA_BLOB *data);
+       void *private_data;
+};
+
+static void messaging_defer_callback_trigger(struct tevent_context *ev,
+                                            struct tevent_immediate *im,
+                                            void *private_data);
+
+static void messaging_defer_callback(
+       struct messaging_context *msg_ctx, struct messaging_rec *rec,
+       void (*fn)(struct messaging_context *msg, void *private_data,
+                  uint32_t msg_type, struct server_id server_id,
+                  DATA_BLOB *data),
+       void *private_data)
+{
+       struct messaging_defer_callback_state *state;
+       struct tevent_immediate *im;
+
+       state = talloc(msg_ctx, struct messaging_defer_callback_state);
+       if (state == NULL) {
+               DEBUG(1, ("talloc failed\n"));
+               return;
+       }
+       state->msg_ctx = msg_ctx;
+       state->fn = fn;
+       state->private_data = private_data;
+
+       state->rec = messaging_rec_dup(state, rec);
+       if (state->rec == NULL) {
+               DEBUG(1, ("talloc failed\n"));
+               TALLOC_FREE(state);
+               return;
+       }
+
+       im = tevent_create_immediate(state);
+       if (im == NULL) {
+               DEBUG(1, ("tevent_create_immediate failed\n"));
+               TALLOC_FREE(state);
+               return;
+       }
+       tevent_schedule_immediate(im, msg_ctx->event_ctx,
+                                 messaging_defer_callback_trigger, state);
+}
+
+static void messaging_defer_callback_trigger(struct tevent_context *ev,
+                                            struct tevent_immediate *im,
+                                            void *private_data)
+{
+       struct messaging_defer_callback_state *state = talloc_get_type_abort(
+               private_data, struct messaging_defer_callback_state);
+       struct messaging_rec *rec = state->rec;
+
+       state->fn(state->msg_ctx, state->private_data, rec->msg_type, rec->src,
+                 &rec->buf);
+       TALLOC_FREE(state);
 }
 
 /*
@@ -381,20 +738,134 @@ void messaging_dispatch_rec(struct messaging_context *msg_ctx,
                            struct messaging_rec *rec)
 {
        struct messaging_callback *cb, *next;
+       unsigned i;
 
        for (cb = msg_ctx->callbacks; cb != NULL; cb = next) {
                next = cb->next;
-               if (cb->msg_type == rec->msg_type) {
+               if (cb->msg_type != rec->msg_type) {
+                       continue;
+               }
+
+               if (messaging_is_self_send(msg_ctx, &rec->dest)) {
+                       /*
+                        * This is a self-send. We are called here from
+                        * messaging_send(), and we don't want to directly
+                        * recurse into the callback but go via a
+                        * tevent_loop_once
+                        */
+                       messaging_defer_callback(msg_ctx, rec, cb->fn,
+                                                cb->private_data);
+               } else {
+                       /*
+                        * This comes from a different process. we are called
+                        * from the event loop, so we should call back
+                        * directly.
+                        */
                        cb->fn(msg_ctx, cb->private_data, rec->msg_type,
                               rec->src, &rec->buf);
-                       /* we continue looking for matching messages
-                          after finding one. This matters for
-                          subsystems like the internal notify code
-                          which register more than one handler for
-                          the same message type */
                }
+               /*
+                * we continue looking for matching messages after finding
+                * one. This matters for subsystems like the internal notify
+                * code which register more than one handler for the same
+                * message type
+                */
+       }
+
+       if (!messaging_append_new_waiters(msg_ctx)) {
+               return;
+       }
+
+       i = 0;
+       while (i < msg_ctx->num_waiters) {
+               struct tevent_req *req;
+               struct messaging_filtered_read_state *state;
+
+               req = msg_ctx->waiters[i];
+               if (req == NULL) {
+                       /*
+                        * This got cleaned up. In the meantime,
+                        * move everything down one. We need
+                        * to keep the order of waiters, as
+                        * other code may depend on this.
+                        */
+                       if (i < msg_ctx->num_waiters - 1) {
+                               memmove(&msg_ctx->waiters[i],
+                                       &msg_ctx->waiters[i+1],
+                                       sizeof(struct tevent_req *) *
+                                           (msg_ctx->num_waiters - i - 1));
+                       }
+                       msg_ctx->num_waiters -= 1;
+                       continue;
+               }
+
+               state = tevent_req_data(
+                       req, struct messaging_filtered_read_state);
+               if (state->filter(rec, state->private_data)) {
+                       messaging_filtered_read_done(req, rec);
+               }
+
+               i += 1;
        }
-       return;
+}
+
+static int mess_parent_dgm_cleanup(void *private_data);
+static void mess_parent_dgm_cleanup_done(struct tevent_req *req);
+
+bool messaging_parent_dgm_cleanup_init(struct messaging_context *msg)
+{
+       struct tevent_req *req;
+
+       req = background_job_send(
+               msg, msg->event_ctx, msg, NULL, 0,
+               lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
+                           60*15),
+               mess_parent_dgm_cleanup, msg);
+       if (req == NULL) {
+               return false;
+       }
+       tevent_req_set_callback(req, mess_parent_dgm_cleanup_done, msg);
+       return true;
+}
+
+static int mess_parent_dgm_cleanup(void *private_data)
+{
+       struct messaging_context *msg_ctx = talloc_get_type_abort(
+               private_data, struct messaging_context);
+       NTSTATUS status;
+
+       status = messaging_dgm_wipe(msg_ctx);
+       DEBUG(10, ("messaging_dgm_wipe returned %s\n", nt_errstr(status)));
+       return lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
+                          60*15);
+}
+
+static void mess_parent_dgm_cleanup_done(struct tevent_req *req)
+{
+       struct messaging_context *msg = tevent_req_callback_data(
+               req, struct messaging_context);
+       NTSTATUS status;
+
+       status = background_job_recv(req);
+       TALLOC_FREE(req);
+       DEBUG(1, ("messaging dgm cleanup job ended with %s\n",
+                 nt_errstr(status)));
+
+       req = background_job_send(
+               msg, msg->event_ctx, msg, NULL, 0,
+               lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
+                           60*15),
+               mess_parent_dgm_cleanup, msg);
+       if (req == NULL) {
+               DEBUG(1, ("background_job_send failed\n"));
+       }
+       tevent_req_set_callback(req, mess_parent_dgm_cleanup_done, msg);
+}
+
+struct messaging_backend *messaging_local_backend(
+       struct messaging_context *msg_ctx)
+{
+       return msg_ctx->local;
 }
 
 /** @} **/