r22846: Chunk one to replace message_send_pid with messaging_send: Deep inside
[sfrench/samba-autobuild/.git] / source / lib / messages.c
index d2313734752e9155cf4c7b33d10ac700b9b2876c..7805f3c6d9ac77f37359545491c91a95a0636295 100644 (file)
@@ -57,8 +57,8 @@ static int received_signal;
 struct message_rec {
        int msg_version;
        int msg_type;
-       struct process_id dest;
-       struct process_id src;
+       struct server_id dest;
+       struct server_id src;
        size_t len;
 };
 
@@ -66,7 +66,7 @@ struct message_rec {
 static struct dispatch_fns {
        struct dispatch_fns *next, *prev;
        int msg_type;
-       void (*fn)(int msg_type, struct process_id pid, void *buf, size_t len,
+       void (*fn)(int msg_type, struct server_id pid, void *buf, size_t len,
                   void *private_data);
        void *private_data;
 } *dispatch_fns;
@@ -103,7 +103,7 @@ static void sig_usr1(void)
  A useful function for testing the message system.
 ****************************************************************************/
 
-static void ping_message(int msg_type, struct process_id src,
+static void ping_message(int msg_type, struct server_id src,
                         void *buf, size_t len, void *private_data)
 {
        const char *msg = buf ? (const char *)buf : "none";
@@ -133,6 +133,9 @@ BOOL message_init(void)
                return False;
        }
 
+       /* Activate the per-hashchain freelist */
+       tdb_set_max_dead(tdb, 5);
+
        CatchSignal(SIGUSR1, SIGNAL_CAST sig_usr1);
 
        message_register(MSG_PING, ping_message, NULL);
@@ -149,14 +152,14 @@ BOOL message_init(void)
  Form a static tdb key from a pid.
 ******************************************************************/
 
-static TDB_DATA message_key_pid(struct process_id pid)
+static TDB_DATA message_key_pid(struct server_id pid)
 {
        static char key[20];
        TDB_DATA kbuf;
 
        slprintf(key, sizeof(key)-1, "PID/%s", procid_str_static(&pid));
        
-       kbuf.dptr = (char *)key;
+       kbuf.dptr = (uint8 *)key;
        kbuf.dsize = strlen(key)+1;
        return kbuf;
 }
@@ -166,7 +169,7 @@ static TDB_DATA message_key_pid(struct process_id pid)
  then delete its record in the database.
 ****************************************************************************/
 
-static BOOL message_notify(struct process_id procid)
+static NTSTATUS message_notify(struct server_id procid)
 {
        pid_t pid = procid.pid;
        int ret;
@@ -180,42 +183,62 @@ static BOOL message_notify(struct process_id procid)
        SMB_ASSERT(pid > 0);
 
        if (euid != 0) {
-               become_root_uid_only();
+               /* If we're not root become so to send the message. */
+               save_re_uid();
+               set_effective_uid(0);
        }
 
        ret = kill(pid, SIGUSR1);
 
        if (euid != 0) {
-               unbecome_root_uid_only();
+               /* Go back to who we were. */
+               int saved_errno = errno;
+               restore_re_uid_fromroot();
+               errno = saved_errno;
        }
 
        if (ret == -1) {
                if (errno == ESRCH) {
-                       DEBUG(2,("pid %d doesn't exist - deleting messages record\n", (int)pid));
+                       DEBUG(2,("pid %d doesn't exist - deleting messages record\n",
+                                (int)pid));
                        tdb_delete(tdb, message_key_pid(procid));
-               } else {
-                       DEBUG(2,("message to process %d failed - %s\n", (int)pid, strerror(errno)));
+
+                       /*
+                        * INVALID_HANDLE is the closest I can think of -- vl
+                        */
+                       return NT_STATUS_INVALID_HANDLE;
                }
-               return False;
+
+               DEBUG(2,("message to process %d failed - %s\n", (int)pid,
+                        strerror(errno)));
+
+               /*
+                * No call to map_nt_error_from_unix -- don't want to link in
+                * errormap.o into lots of utils.
+                */
+
+               if (errno == EINVAL) return NT_STATUS_INVALID_PARAMETER;
+               if (errno == EPERM)  return NT_STATUS_ACCESS_DENIED;
+               return NT_STATUS_UNSUCCESSFUL;
        }
 
-       return True;
+       return NT_STATUS_OK;
 }
 
 /****************************************************************************
  Send a message to a particular pid.
 ****************************************************************************/
 
-static BOOL message_send_pid_internal(struct process_id pid, int msg_type,
-                                     const void *buf, size_t len,
-                                     BOOL duplicates_allowed,
-                                     unsigned int timeout)
+static NTSTATUS message_send_pid_internal(struct server_id pid, int msg_type,
+                                         const void *buf, size_t len,
+                                         BOOL duplicates_allowed,
+                                         unsigned int timeout)
 {
        TDB_DATA kbuf;
        TDB_DATA dbuf;
        TDB_DATA old_dbuf;
        struct message_rec rec;
-       char *ptr;
+       uint8 *ptr;
        struct message_rec prec;
 
        /* NULL pointer means implicit length zero. */
@@ -238,9 +261,10 @@ static BOOL message_send_pid_internal(struct process_id pid, int msg_type,
 
        kbuf = message_key_pid(pid);
 
-       dbuf.dptr = (char *)SMB_MALLOC(len + sizeof(rec));
-       if (!dbuf.dptr)
-               return False;
+       dbuf.dptr = (uint8 *)SMB_MALLOC(len + sizeof(rec));
+       if (!dbuf.dptr) {
+               return NT_STATUS_NO_MEMORY;
+       }
 
        memcpy(dbuf.dptr, &rec, sizeof(rec));
        if (len > 0 && buf)
@@ -255,13 +279,15 @@ static BOOL message_send_pid_internal(struct process_id pid, int msg_type,
                /* lock the record for the destination */
                if (timeout) {
                        if (tdb_chainlock_with_timeout(tdb, kbuf, timeout) == -1) {
-                               DEBUG(0,("message_send_pid_internal: failed to get chainlock with timeout %ul.\n", timeout));
-                               return False;
+                               DEBUG(0,("message_send_pid_internal: failed to get "
+                                        "chainlock with timeout %ul.\n", timeout));
+                               return NT_STATUS_IO_TIMEOUT;
                        }
                } else {
                        if (tdb_chainlock(tdb, kbuf) == -1) {
-                               DEBUG(0,("message_send_pid_internal: failed to get chainlock.\n"));
-                               return False;
+                               DEBUG(0,("message_send_pid_internal: failed to get "
+                                        "chainlock.\n"));
+                               return NT_STATUS_LOCK_NOT_GRANTED;
                        }
                }       
                tdb_append(tdb, kbuf, dbuf);
@@ -275,13 +301,15 @@ static BOOL message_send_pid_internal(struct process_id pid, int msg_type,
        /* lock the record for the destination */
        if (timeout) {
                if (tdb_chainlock_with_timeout(tdb, kbuf, timeout) == -1) {
-                       DEBUG(0,("message_send_pid_internal: failed to get chainlock with timeout %ul.\n", timeout));
-                       return False;
+                       DEBUG(0,("message_send_pid_internal: failed to get chainlock "
+                                "with timeout %ul.\n", timeout));
+                       return NT_STATUS_IO_TIMEOUT;
                }
        } else {
                if (tdb_chainlock(tdb, kbuf) == -1) {
-                       DEBUG(0,("message_send_pid_internal: failed to get chainlock.\n"));
-                       return False;
+                       DEBUG(0,("message_send_pid_internal: failed to get "
+                                "chainlock.\n"));
+                       return NT_STATUS_LOCK_NOT_GRANTED;
                }
        }       
 
@@ -300,7 +328,7 @@ static BOOL message_send_pid_internal(struct process_id pid, int msg_type,
 
        /* Not a new record. Check for duplicates. */
 
-       for(ptr = (char *)old_dbuf.dptr; ptr < old_dbuf.dptr + old_dbuf.dsize; ) {
+       for(ptr = old_dbuf.dptr; ptr < old_dbuf.dptr + old_dbuf.dsize; ) {
                /*
                 * First check if the message header matches, then, if it's a non-zero
                 * sized message, check if the data matches. If so it's a duplicate and
@@ -310,10 +338,11 @@ static BOOL message_send_pid_internal(struct process_id pid, int msg_type,
                if (!memcmp(ptr, &rec, sizeof(rec))) {
                        if (!len || (len && !memcmp( ptr + sizeof(rec), buf, len))) {
                                tdb_chainunlock(tdb, kbuf);
-                               DEBUG(10,("message_send_pid_internal: discarding duplicate message.\n"));
+                               DEBUG(10,("message_send_pid_internal: discarding "
+                                         "duplicate message.\n"));
                                SAFE_FREE(dbuf.dptr);
                                SAFE_FREE(old_dbuf.dptr);
-                               return True;
+                               return NT_STATUS_OK;
                        }
                }
                memcpy(&prec, ptr, sizeof(prec));
@@ -336,30 +365,34 @@ static BOOL message_send_pid_internal(struct process_id pid, int msg_type,
  Send a message to a particular pid - no timeout.
 ****************************************************************************/
 
-BOOL message_send_pid(struct process_id pid, int msg_type, const void *buf, size_t len, BOOL duplicates_allowed)
+NTSTATUS message_send_pid(struct server_id pid, int msg_type, const void *buf,
+                         size_t len, BOOL duplicates_allowed)
 {
-       return message_send_pid_internal(pid, msg_type, buf, len, duplicates_allowed, 0);
+       return message_send_pid_internal(pid, msg_type, buf, len,
+                                        duplicates_allowed, 0);
 }
 
 /****************************************************************************
  Send a message to a particular pid, with timeout in seconds.
 ****************************************************************************/
 
-BOOL message_send_pid_with_timeout(struct process_id pid, int msg_type, const void *buf, size_t len,
-               BOOL duplicates_allowed, unsigned int timeout)
+NTSTATUS message_send_pid_with_timeout(struct server_id pid, int msg_type,
+                                      const void *buf, size_t len,
+                                      BOOL duplicates_allowed, unsigned int timeout)
 {
-       return message_send_pid_internal(pid, msg_type, buf, len, duplicates_allowed, timeout);
+       return message_send_pid_internal(pid, msg_type, buf, len, duplicates_allowed,
+                                        timeout);
 }
 
 /****************************************************************************
  Count the messages pending for a particular pid. Expensive....
 ****************************************************************************/
 
-unsigned int messages_pending_for_pid(struct process_id pid)
+unsigned int messages_pending_for_pid(struct server_id pid)
 {
        TDB_DATA kbuf;
        TDB_DATA dbuf;
-       char *buf;
+       uint8 *buf;
        unsigned int message_count = 0;
 
        kbuf = message_key_pid(pid);
@@ -415,7 +448,7 @@ static BOOL retrieve_all_messages(char **msgs_buf, size_t *total_len)
                return False;
        }
 
-       *msgs_buf = dbuf.dptr;
+       *msgs_buf = (char *)dbuf.dptr;
        *total_len = dbuf.dsize;
 
        return True;
@@ -426,7 +459,7 @@ static BOOL retrieve_all_messages(char **msgs_buf, size_t *total_len)
 ****************************************************************************/
 
 static BOOL message_recv(char *msgs_buf, size_t total_len, int *msg_type,
-                        struct process_id *src, char **buf, size_t *len)
+                        struct server_id *src, char **buf, size_t *len)
 {
        struct message_rec rec;
        char *ret_buf = *buf;
@@ -468,7 +501,7 @@ static BOOL message_recv(char *msgs_buf, size_t total_len, int *msg_type,
 void message_dispatch(void)
 {
        int msg_type;
-       struct process_id src;
+       struct server_id src;
        char *buf;
        char *msgs_buf;
        size_t len, total_len;
@@ -519,7 +552,7 @@ void message_dispatch(void)
 ****************************************************************************/
 
 void message_register(int msg_type, 
-                     void (*fn)(int msg_type, struct process_id pid,
+                     void (*fn)(int msg_type, struct server_id pid,
                                 void *buf, size_t len,
                                 void *private_data),
                      void *private_data)
@@ -586,6 +619,7 @@ static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void
 {
        struct connections_data crec;
        struct msg_all *msg_all = (struct msg_all *)state;
+       NTSTATUS status;
 
        if (dbuf.dsize != sizeof(crec))
                return 0;
@@ -603,18 +637,17 @@ static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void
        /* If the msg send fails because the pid was not found (i.e. smbd died), 
         * the msg has already been deleted from the messages.tdb.*/
 
-       if (!message_send_pid(crec.pid, msg_all->msg_type,
-                             msg_all->buf, msg_all->len,
-                             msg_all->duplicates)) {
+       status = message_send_pid(crec.pid, msg_all->msg_type,
+                                 msg_all->buf, msg_all->len,
+                                 msg_all->duplicates);
+
+       if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
                
                /* If the pid was not found delete the entry from connections.tdb */
 
-               if (errno == ESRCH) {
-                       DEBUG(2,("pid %s doesn't exist - deleting connections %d [%s]\n",
-                                procid_str_static(&crec.pid),
-                                crec.cnum, crec.name));
-                       tdb_delete(the_tdb, kbuf);
-               }
+               DEBUG(2,("pid %s doesn't exist - deleting connections %d [%s]\n",
+                        procid_str_static(&crec.pid), crec.cnum, crec.servicename));
+               tdb_delete(the_tdb, kbuf);
        }
        msg_all->n_sent++;
        return 0;
@@ -632,7 +665,7 @@ static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void
  *
  * @retval True for success.
  **/
-BOOL message_send_all(TDB_CONTEXT *conn_tdb, int msg_type,
+BOOL message_send_all(int msg_type,
                      const void *buf, size_t len,
                      BOOL duplicates_allowed,
                      int *n_sent)
@@ -658,7 +691,7 @@ BOOL message_send_all(TDB_CONTEXT *conn_tdb, int msg_type,
        msg_all.duplicates = duplicates_allowed;
        msg_all.n_sent = 0;
 
-       tdb_traverse(conn_tdb, traverse_fn, &msg_all);
+       connections_traverse(traverse_fn, &msg_all);
        if (n_sent)
                *n_sent = msg_all.n_sent;
        return True;
@@ -678,4 +711,133 @@ void message_unblock(void)
 {
        BlockSignals(False, SIGUSR1);
 }
+
+/*
+ * Samba4 API wrapper around the Samba3 implementation. Yes, I know, we could
+ * import the whole Samba4 thing, but I want notify.c from Samba4 in first.
+ */
+
+struct messaging_callback {
+       struct messaging_callback *prev, *next;
+       uint32 msg_type;
+       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_context {
+       struct server_id id;
+       struct messaging_callback *callbacks;
+};
+
+static int messaging_context_destructor(struct messaging_context *ctx)
+{
+       struct messaging_callback *cb;
+
+       for (cb = ctx->callbacks; cb; cb = cb->next) {
+               /*
+                * We unconditionally remove all instances of our callback
+                * from the tdb basis.
+                */
+               message_deregister(cb->msg_type);
+       }
+       return 0;
+}
+
+struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx, 
+                                        struct server_id server_id, 
+                                        struct event_context *ev)
+{
+       struct messaging_context *ctx;
+
+       if (!(ctx = TALLOC_ZERO_P(mem_ctx, struct messaging_context))) {
+               return NULL;
+       }
+
+       ctx->id = server_id;
+       talloc_set_destructor(ctx, messaging_context_destructor);
+       return ctx;
+}
+
+static void messaging_callback(int msg_type, struct server_id pid,
+                              void *buf, size_t len, void *private_data)
+{
+       struct messaging_context *ctx = talloc_get_type_abort(
+               private_data, struct messaging_context);
+       struct messaging_callback *cb, *next;
+
+       for (cb = ctx->callbacks; cb; cb = next) {
+               /*
+                * Allow a callback to remove itself
+                */
+               next = cb->next;
+
+               if (msg_type == cb->msg_type) {
+                       DATA_BLOB blob;
+
+                       blob.data = (uint8 *)buf;
+                       blob.length = len;
+
+                       cb->fn(ctx, cb->private_data, msg_type, pid, &blob);
+               }
+       }
+}
+
+/*
+ * Register a dispatch function for a particular message type. Allow multiple
+ * registrants
+*/
+NTSTATUS messaging_register(struct messaging_context *ctx, void *private_data,
+                           uint32_t msg_type,
+                           void (*fn)(struct messaging_context *msg,
+                                      void *private_data, 
+                                      uint32_t msg_type, 
+                                      struct server_id server_id,
+                                      DATA_BLOB *data))
+{
+       struct messaging_callback *cb;
+
+       if (!(cb = talloc(ctx, struct messaging_callback))) {
+               return NT_STATUS_NO_MEMORY;
+       }
+
+       cb->msg_type = msg_type;
+       cb->fn = fn;
+       cb->private_data = private_data;
+
+       DLIST_ADD(ctx->callbacks, cb);
+       message_register(msg_type, messaging_callback, ctx);
+       return NT_STATUS_OK;
+}
+
+/*
+  De-register the function for a particular message type.
+*/
+void messaging_deregister(struct messaging_context *ctx, uint32_t msg_type,
+                         void *private_data)
+{
+       struct messaging_callback *cb, *next;
+
+       for (cb = ctx->callbacks; cb; cb = next) {
+               next = cb->next;
+               if ((cb->msg_type == msg_type)
+                   && (cb->private_data == private_data)) {
+                       DLIST_REMOVE(ctx->callbacks, cb);
+                       TALLOC_FREE(cb);
+               }
+       }
+}
+
+/*
+  Send a message to a particular server
+*/
+NTSTATUS messaging_send(struct messaging_context *msg,
+                       struct server_id server, 
+                       uint32_t msg_type, const DATA_BLOB *data)
+{
+       return message_send_pid_internal(server, msg_type, data->data,
+                                        data->length, True, 0);
+}
+
 /** @} **/