source3/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_WINBIND                0x0008
  46 #define FLAG_MSG_PRINT_GENERAL          0x0010
  47 /* dbwrap messages 4001-4999 */
  48 #define FLAG_MSG_DBWRAP                 0x0020
  49
  50 /*
  51  * ctdb gives us 64-bit server ids for messaging_send. This is done to avoid
  52  * pid clashes and to be able to register for special messages like "all
  53  * smbds".
  54  *
  55  * Normal individual server id's have the upper 32 bits to 0, I picked "1" for
  56  * Samba, other subsystems might use something else.
  57  */
  58
  59 #define MSG_SRVID_SAMBA 0x0000000100000000LL
  60
  61 #include "librpc/gen_ndr/server_id.h"
  62
  63 #define MSG_BROADCAST_PID_STR   "0:0"
  64
  65 struct messaging_context;
  66 struct messaging_rec;
  67
  68 struct messaging_backend {
  69         int (*send_fn)(struct server_id src,
  70                        struct server_id pid, int msg_type,
  71                        const struct iovec *iov, int iovlen,
  72                        const int *fds, size_t num_fds,
  73                        struct messaging_backend *backend);
  74         void *private_data;
  75 };
  76
  77 NTSTATUS messaging_ctdbd_init(struct messaging_context *msg_ctx,
  78                               TALLOC_CTX *mem_ctx,
  79                               struct messaging_backend **presult);
  80 struct ctdbd_connection *messaging_ctdbd_connection(void);
  81
  82 bool message_send_all(struct messaging_context *msg_ctx,
  83                       int msg_type,
  84                       const void *buf, size_t len,
  85                       int *n_sent);
  86 struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx,
  87                                          struct tevent_context *ev);
  88
  89 struct server_id messaging_server_id(const struct messaging_context *msg_ctx);
  90 struct tevent_context *messaging_tevent_context(
  91         struct messaging_context *msg_ctx);
  92 struct server_id_db *messaging_names_db(struct messaging_context *msg_ctx);
  93
  94 /*
  95  * re-init after a fork
  96  */
  97 NTSTATUS messaging_reinit(struct messaging_context *msg_ctx);
  98
  99 NTSTATUS messaging_register(struct messaging_context *msg_ctx,
 100                             void *private_data,
 101                             uint32_t msg_type,
 102                             void (*fn)(struct messaging_context *msg,
 103                                        void *private_data,
 104                                        uint32_t msg_type,
 105                                        struct server_id server_id,
 106                                        DATA_BLOB *data));
 107 void messaging_deregister(struct messaging_context *ctx, uint32_t msg_type,
 108                           void *private_data);
 109
 110 /**
 111  * CAVEAT:
 112  *
 113  * While the messaging_send*() functions are synchronuous by API,
 114  * they trigger a tevent-based loop upon sending bigger messages.
 115  *
 116  * Hence callers should not use these in purely synchonous code,
 117  * but run a tevent_loop instead.
 118  */
 119 NTSTATUS messaging_send(struct messaging_context *msg_ctx,
 120                         struct server_id server,
 121                         uint32_t msg_type, const DATA_BLOB *data);
 122
 123 NTSTATUS messaging_send_buf(struct messaging_context *msg_ctx,
 124                             struct server_id server, uint32_t msg_type,
 125                             const uint8_t *buf, size_t len);
 126 NTSTATUS messaging_send_iov_from(struct messaging_context *msg_ctx,
 127                                  struct server_id src, struct server_id dst,
 128                                  uint32_t msg_type,
 129                                  const struct iovec *iov, int iovlen,
 130                                  const int *fds, size_t num_fds);
 131 NTSTATUS messaging_send_iov(struct messaging_context *msg_ctx,
 132                             struct server_id server, uint32_t msg_type,
 133                             const struct iovec *iov, int iovlen,
 134                             const int *fds, size_t num_fds);
 135 void messaging_dispatch_rec(struct messaging_context *msg_ctx,
 136                             struct messaging_rec *rec);
 137
 138 struct tevent_req *messaging_filtered_read_send(
 139         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 140         struct messaging_context *msg_ctx,
 141         bool (*filter)(struct messaging_rec *rec, void *private_data),
 142         void *private_data);
 143 int messaging_filtered_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 144                                  struct messaging_rec **presult);
 145
 146 struct tevent_req *messaging_read_send(TALLOC_CTX *mem_ctx,
 147                                        struct tevent_context *ev,
 148                                        struct messaging_context *msg,
 149                                        uint32_t msg_type);
 150 int messaging_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 151                         struct messaging_rec **presult);
 152
 153 struct tevent_req *messaging_handler_send(
 154         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 155         struct messaging_context *msg_ctx, uint32_t msg_type,
 156         bool (*handler)(struct messaging_context *msg_ctx,
 157                         struct messaging_rec **rec, void *private_data),
 158         void *private_data);
 159 int messaging_handler_recv(struct tevent_req *req);
 160
 161 int messaging_cleanup(struct messaging_context *msg_ctx, pid_t pid);
 162
 163 bool messaging_parent_dgm_cleanup_init(struct messaging_context *msg);
 164
 165 #include "librpc/gen_ndr/ndr_messaging.h"
 166
 167 #endif