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 /*
  40  * ctdb gives us 64-bit server ids for messaging_send. This is done to avoid
  41  * pid clashes and to be able to register for special messages like "all
  42  * smbds".
  43  *
  44  * Normal individual server id's have the upper 32 bits to 0, I picked "1" for
  45  * Samba, other subsystems might use something else.
  46  */
  47
  48 #define MSG_SRVID_SAMBA 0x0000000100000000LL
  49
  50 #include "librpc/gen_ndr/server_id.h"
  51 #include "lib/util/data_blob.h"
  52 #include "system/network.h"
  53
  54 #define MSG_BROADCAST_PID_STR   "0:0"
  55
  56 struct messaging_context;
  57 struct messaging_rec;
  58
  59 struct messaging_backend {
  60         int (*send_fn)(struct server_id src,
  61                        struct server_id pid, int msg_type,
  62                        const struct iovec *iov, int iovlen,
  63                        const int *fds, size_t num_fds,
  64                        struct messaging_backend *backend);
  65         void *private_data;
  66 };
  67
  68 int messaging_ctdbd_init(struct messaging_context *msg_ctx,
  69                          TALLOC_CTX *mem_ctx,
  70                          struct messaging_backend **presult);
  71 int messaging_ctdbd_reinit(struct messaging_context *msg_ctx,
  72                            TALLOC_CTX *mem_ctx,
  73                            struct messaging_backend *backend);
  74 struct ctdbd_connection *messaging_ctdbd_connection(void);
  75
  76 struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx,
  77                                          struct tevent_context *ev);
  78 NTSTATUS messaging_init_client(TALLOC_CTX *mem_ctx,
  79                                struct tevent_context *ev,
  80                                struct messaging_context **pmsg_ctx);
  81
  82 struct server_id messaging_server_id(const struct messaging_context *msg_ctx);
  83 struct tevent_context *messaging_tevent_context(
  84         struct messaging_context *msg_ctx);
  85 struct server_id_db *messaging_names_db(struct messaging_context *msg_ctx);
  86
  87 /*
  88  * re-init after a fork
  89  */
  90 NTSTATUS messaging_reinit(struct messaging_context *msg_ctx);
  91
  92 NTSTATUS messaging_register(struct messaging_context *msg_ctx,
  93                             void *private_data,
  94                             uint32_t msg_type,
  95                             void (*fn)(struct messaging_context *msg,
  96                                        void *private_data,
  97                                        uint32_t msg_type,
  98                                        struct server_id server_id,
  99                                        DATA_BLOB *data));
 100 void messaging_deregister(struct messaging_context *ctx, uint32_t msg_type,
 101                           void *private_data);
 102
 103 /**
 104  * CAVEAT:
 105  *
 106  * While the messaging_send*() functions are synchronuous by API,
 107  * they trigger a tevent-based loop upon sending bigger messages.
 108  *
 109  * Hence callers should not use these in purely synchonous code,
 110  * but run a tevent_loop instead.
 111  */
 112 NTSTATUS messaging_send(struct messaging_context *msg_ctx,
 113                         struct server_id server,
 114                         uint32_t msg_type, const DATA_BLOB *data);
 115
 116 NTSTATUS messaging_send_buf(struct messaging_context *msg_ctx,
 117                             struct server_id server, uint32_t msg_type,
 118                             const uint8_t *buf, size_t len);
 119 int messaging_send_iov_from(struct messaging_context *msg_ctx,
 120                             struct server_id src, struct server_id dst,
 121                             uint32_t msg_type,
 122                             const struct iovec *iov, int iovlen,
 123                             const int *fds, size_t num_fds);
 124 NTSTATUS messaging_send_iov(struct messaging_context *msg_ctx,
 125                             struct server_id server, uint32_t msg_type,
 126                             const struct iovec *iov, int iovlen,
 127                             const int *fds, size_t num_fds);
 128
 129 struct tevent_req *messaging_filtered_read_send(
 130         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 131         struct messaging_context *msg_ctx,
 132         bool (*filter)(struct messaging_rec *rec, void *private_data),
 133         void *private_data);
 134 int messaging_filtered_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 135                                  struct messaging_rec **presult);
 136
 137 struct tevent_req *messaging_read_send(TALLOC_CTX *mem_ctx,
 138                                        struct tevent_context *ev,
 139                                        struct messaging_context *msg,
 140                                        uint32_t msg_type);
 141 int messaging_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 142                         struct messaging_rec **presult);
 143
 144 struct tevent_req *messaging_handler_send(
 145         TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 146         struct messaging_context *msg_ctx, uint32_t msg_type,
 147         bool (*handler)(struct messaging_context *msg_ctx,
 148                         struct messaging_rec **rec, void *private_data),
 149         void *private_data);
 150 int messaging_handler_recv(struct tevent_req *req);
 151
 152 int messaging_cleanup(struct messaging_context *msg_ctx, pid_t pid);
 153
 154 bool messaging_parent_dgm_cleanup_init(struct messaging_context *msg);
 155
 156 #include "librpc/gen_ndr/ndr_messaging.h"
 157
 158 #endif