source/include/messages.h

   1 /*
   2    Unix SMB/CIFS implementation.
   3    messages.c header
   4    Copyright (C) Andrew Tridgell 2000
   5    Copyright (C) 2001, 2002 by Martin Pool
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #ifndef _MESSAGES_H_
  22 #define _MESSAGES_H_
  23
  24 /* change the message version with any incompatible changes in the protocol */
  25 #define MESSAGE_VERSION 2
  26
  27 /*
  28  * Special flags passed to message_send. Allocated from the top, lets see when
  29  * it collides with the message types in the lower 16 bits :-)
  30  */
  31
  32 /*
  33  * Under high load, this message can be dropped. Use for notify-style
  34  * messages that are not critical for correct operation.
  35  */
  36 #define MSG_FLAG_LOWPRIORITY            0x80000000
  37
  38
  39 /* Flags to classify messages - used in message_send_all() */
  40 /* Sender will filter by flag. */
  41
  42 #define FLAG_MSG_GENERAL                0x0001
  43 #define FLAG_MSG_SMBD                   0x0002
  44 #define FLAG_MSG_NMBD                   0x0004
  45 #define FLAG_MSG_PRINT_NOTIFY           0x0008
  46 #define FLAG_MSG_PRINT_GENERAL          0x0010
  47 /* dbwrap messages 4001-4999 */
  48 #define FLAG_MSG_DBWRAP                 0x0020
  49
  50
  51 /*
  52  * Virtual Node Numbers are identifying a node within a cluster. Ctdbd sets
  53  * this, we retrieve our vnn from it.
  54  */
  55
  56 #define NONCLUSTER_VNN (0xFFFFFFFF)
  57
  58 /*
  59  * ctdb gives us 64-bit server ids for messaging_send. This is done to avoid
  60  * pid clashes and to be able to register for special messages like "all
  61  * smbds".
  62  *
  63  * Normal individual server id's have the upper 32 bits to 0, I picked "1" for
  64  * Samba, other subsystems might use something else.
  65  */
  66
  67 #define MSG_SRVID_SAMBA 0x0000000100000000LL
  68
  69
  70 struct server_id {
  71         pid_t pid;
  72 #ifdef CLUSTER_SUPPORT
  73         uint32 vnn;
  74 #endif
  75 };
  76
  77 #ifdef CLUSTER_SUPPORT
  78 #define MSG_BROADCAST_PID_STR   "0:0"
  79 #else
  80 #define MSG_BROADCAST_PID_STR   "0"
  81 #endif
  82
  83 struct messaging_context;
  84 struct messaging_rec;
  85 struct data_blob;
  86
  87 /*
  88  * struct messaging_context belongs to messages.c, but because we still have
  89  * messaging_dispatch, we need it here. Once we get rid of signals for
  90  * notifying processes, this will go.
  91  */
  92
  93 struct messaging_context {
  94         struct server_id id;
  95         struct event_context *event_ctx;
  96         struct messaging_callback *callbacks;
  97
  98         struct messaging_backend *local;
  99         struct messaging_backend *remote;
 100 };
 101
 102 struct messaging_backend {
 103         NTSTATUS (*send_fn)(struct messaging_context *msg_ctx,
 104                             struct server_id pid, int msg_type,
 105                             const struct data_blob *data,
 106                             struct messaging_backend *backend);
 107         void *private_data;
 108 };
 109
 110 NTSTATUS messaging_tdb_init(struct messaging_context *msg_ctx,
 111                             TALLOC_CTX *mem_ctx,
 112                             struct messaging_backend **presult);
 113 void message_dispatch(struct messaging_context *msg_ctx);
 114
 115 NTSTATUS messaging_ctdbd_init(struct messaging_context *msg_ctx,
 116                               TALLOC_CTX *mem_ctx,
 117                               struct messaging_backend **presult);
 118 struct ctdbd_connection *messaging_ctdbd_connection(void);
 119
 120 bool message_send_all(struct messaging_context *msg_ctx,
 121                       int msg_type,
 122                       const void *buf, size_t len,
 123                       int *n_sent);
 124 struct event_context *messaging_event_context(struct messaging_context *msg_ctx);
 125 struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx,
 126                                          struct server_id server_id,
 127                                          struct event_context *ev);
 128
 129 /*
 130  * re-init after a fork
 131  */
 132 NTSTATUS messaging_reinit(struct messaging_context *msg_ctx);
 133
 134 NTSTATUS messaging_register(struct messaging_context *msg_ctx,
 135                             void *private_data,
 136                             uint32_t msg_type,
 137                             void (*fn)(struct messaging_context *msg,
 138                                        void *private_data,
 139                                        uint32_t msg_type,
 140                                        struct server_id server_id,
 141                                        struct data_blob *data));
 142 void messaging_deregister(struct messaging_context *ctx, uint32_t msg_type,
 143                           void *private_data);
 144 NTSTATUS messaging_send(struct messaging_context *msg_ctx,
 145                         struct server_id server,
 146                         uint32_t msg_type, const struct data_blob *data);
 147 NTSTATUS messaging_send_buf(struct messaging_context *msg_ctx,
 148                             struct server_id server, uint32_t msg_type,
 149                             const uint8 *buf, size_t len);
 150 void messaging_dispatch_rec(struct messaging_context *msg_ctx,
 151                             struct messaging_rec *rec);
 152
 153 #endif