source3/lib/messages_ctdbd.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba internal messaging functions
   4    Copyright (C) 2007 by Volker Lendecke
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "messages.h"
  22 #include "util_tdb.h"
  23 #include "lib/util/iov_buf.h"
  24 #include "lib/messages_util.h"
  25 #include "ctdbd_conn.h"
  26 #include "lib/cluster_support.h"
  27
  28
  29 struct messaging_ctdbd_context {
  30         struct ctdbd_connection *conn;
  31 };
  32
  33 /*
  34  * This is a Samba3 hack/optimization. Routines like process_exists need to
  35  * talk to ctdbd, and they don't get handed a messaging context.
  36  */
  37 static struct ctdbd_connection *global_ctdbd_connection;
  38 static int global_ctdb_connection_pid;
  39
  40 struct ctdbd_connection *messaging_ctdbd_connection(void)
  41 {
  42         if (!lp_clustering()) {
  43                 return NULL;
  44         }
  45
  46         if (global_ctdb_connection_pid == 0 &&
  47             global_ctdbd_connection == NULL) {
  48                 struct tevent_context *ev;
  49                 struct messaging_context *msg;
  50
  51                 ev = samba_tevent_context_init(NULL);
  52                 if (!ev) {
  53                         DEBUG(0,("samba_tevent_context_init failed\n"));
  54                         return NULL;
  55                 }
  56
  57                 msg = messaging_init(NULL, ev);
  58                 if (!msg) {
  59                         DEBUG(0,("messaging_init failed\n"));
  60                         return NULL;
  61                 }
  62         }
  63
  64         if (global_ctdb_connection_pid != getpid()) {
  65                 DEBUG(0,("messaging_ctdbd_connection():"
  66                          "valid for pid[%jd] but it's [%jd]\n",
  67                          (intmax_t)global_ctdb_connection_pid,
  68                          (intmax_t)getpid()));
  69                 smb_panic("messaging_ctdbd_connection() invalid process\n");
  70         }
  71
  72         return global_ctdbd_connection;
  73 }
  74
  75 static int messaging_ctdb_send(struct server_id src,
  76                                struct server_id pid, int msg_type,
  77                                const struct iovec *iov, int iovlen,
  78                                const int *fds, size_t num_fds,
  79                                struct messaging_backend *backend)
  80 {
  81         struct messaging_ctdbd_context *ctx = talloc_get_type_abort(
  82                 backend->private_data, struct messaging_ctdbd_context);
  83         uint8_t hdr[MESSAGE_HDR_LENGTH];
  84         struct iovec iov2[iovlen+1];
  85
  86         if (num_fds > 0) {
  87                 return ENOSYS;
  88         }
  89
  90         message_hdr_put(hdr, msg_type, src, pid);
  91         iov2[0] = (struct iovec){ .iov_base = hdr, .iov_len = sizeof(hdr) };
  92         memcpy(&iov2[1], iov, iovlen * sizeof(*iov));
  93
  94         return ctdbd_messaging_send_iov(ctx->conn, pid.vnn, pid.pid,
  95                                         iov2, iovlen+1);
  96 }
  97
  98 static int messaging_ctdbd_destructor(struct messaging_ctdbd_context *ctx)
  99 {
 100         /*
 101          * The global connection just went away
 102          */
 103         global_ctdb_connection_pid = 0;
 104         global_ctdbd_connection = NULL;
 105         return 0;
 106 }
 107
 108 static int messaging_ctdb_recv(
 109         uint32_t src_vnn, uint32_t dst_vnn, uint64_t dst_srvid,
 110         const uint8_t *msg, size_t msg_len, void *private_data)
 111 {
 112         struct messaging_context *msg_ctx = talloc_get_type_abort(
 113                 private_data, struct messaging_context);
 114         struct server_id me = messaging_server_id(msg_ctx);
 115         NTSTATUS status;
 116         struct iovec iov;
 117         struct server_id src, dst;
 118         enum messaging_type msg_type;
 119         struct server_id_buf idbuf;
 120
 121         if (msg_len < MESSAGE_HDR_LENGTH) {
 122                 DEBUG(1, ("%s: message too short: %u\n", __func__,
 123                           (unsigned)msg_len));
 124                 return 0;
 125         }
 126
 127         message_hdr_get(&msg_type, &src, &dst, msg);
 128
 129         iov = (struct iovec) {
 130                 .iov_base = discard_const_p(uint8_t, msg) + MESSAGE_HDR_LENGTH,
 131                 .iov_len = msg_len - MESSAGE_HDR_LENGTH
 132         };
 133
 134         DEBUG(10, ("%s: Received message 0x%x len %u from %s\n",
 135                    __func__, (unsigned)msg_type, (unsigned)msg_len,
 136                    server_id_str_buf(src, &idbuf)));
 137
 138         if (!server_id_same_process(&me, &dst)) {
 139                 struct server_id_buf id1, id2;
 140
 141                 DEBUG(10, ("%s: I'm %s, ignoring msg to %s\n", __func__,
 142                            server_id_str_buf(me, &id1),
 143                            server_id_str_buf(dst, &id2)));
 144                 return 0;
 145         }
 146
 147         /*
 148          * Go through the event loop
 149          */
 150
 151         status = messaging_send_iov_from(msg_ctx, src, dst, msg_type,
 152                                          &iov, 1, NULL, 0);
 153
 154         if (!NT_STATUS_IS_OK(status)) {
 155                 DEBUG(10, ("%s: messaging_send_iov_from failed: %s\n",
 156                            __func__, nt_errstr(status)));
 157         }
 158
 159         return 0;
 160 }
 161
 162 NTSTATUS messaging_ctdbd_init(struct messaging_context *msg_ctx,
 163                               TALLOC_CTX *mem_ctx,
 164                               struct messaging_backend **presult)
 165 {
 166         struct messaging_backend *result;
 167         struct messaging_ctdbd_context *ctx;
 168         int ret;
 169
 170         if (!(result = talloc(mem_ctx, struct messaging_backend))) {
 171                 DEBUG(0, ("talloc failed\n"));
 172                 return NT_STATUS_NO_MEMORY;
 173         }
 174
 175         if (!(ctx = talloc(result, struct messaging_ctdbd_context))) {
 176                 DEBUG(0, ("talloc failed\n"));
 177                 TALLOC_FREE(result);
 178                 return NT_STATUS_NO_MEMORY;
 179         }
 180
 181         ret = ctdbd_messaging_connection(ctx, lp_ctdbd_socket(),
 182                                          lp_ctdb_timeout(), &ctx->conn);
 183
 184         if (ret != 0) {
 185                 DEBUG(10, ("ctdbd_messaging_connection failed: %s\n",
 186                            strerror(ret)));
 187                 TALLOC_FREE(result);
 188                 return map_nt_error_from_unix(ret);
 189         }
 190
 191         ret = ctdbd_register_msg_ctx(ctx->conn, msg_ctx,
 192                                      messaging_tevent_context(msg_ctx));
 193
 194         if (ret != 0) {
 195                 DEBUG(10, ("ctdbd_register_msg_ctx failed: %s\n",
 196                            strerror(ret)));
 197                 TALLOC_FREE(result);
 198                 return map_nt_error_from_unix(ret);
 199         }
 200
 201         ret = register_with_ctdbd(ctx->conn, getpid(),
 202                                   messaging_ctdb_recv, msg_ctx);
 203         if (ret != 0) {
 204                 DEBUG(10, ("register_with_ctdbd failed: %s\n",
 205                            strerror(ret)));
 206                 TALLOC_FREE(result);
 207                 return map_nt_error_from_unix(ret);
 208         }
 209
 210         global_ctdb_connection_pid = getpid();
 211         global_ctdbd_connection = ctx->conn;
 212         talloc_set_destructor(ctx, messaging_ctdbd_destructor);
 213
 214         set_my_vnn(ctdbd_vnn(ctx->conn));
 215
 216         result->send_fn = messaging_ctdb_send;
 217         result->private_data = (void *)ctx;
 218
 219         *presult = result;
 220         return NT_STATUS_OK;
 221 }