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         struct tevent_fd *fde;
  32 };
  33
  34 /*
  35  * This is a Samba3 hack/optimization. Routines like process_exists need to
  36  * talk to ctdbd, and they don't get handed a messaging context.
  37  */
  38 static struct ctdbd_connection *global_ctdbd_connection;
  39 static int global_ctdb_connection_pid;
  40
  41 struct ctdbd_connection *messaging_ctdbd_connection(void)
  42 {
  43         if (!lp_clustering()) {
  44                 return NULL;
  45         }
  46
  47         if (global_ctdb_connection_pid == 0 &&
  48             global_ctdbd_connection == NULL) {
  49                 struct tevent_context *ev;
  50                 struct messaging_context *msg;
  51
  52                 ev = samba_tevent_context_init(NULL);
  53                 if (!ev) {
  54                         DEBUG(0,("samba_tevent_context_init failed\n"));
  55                         return NULL;
  56                 }
  57
  58                 msg = messaging_init(NULL, ev);
  59                 if (!msg) {
  60                         DEBUG(0,("messaging_init failed\n"));
  61                         return NULL;
  62                 }
  63         }
  64
  65         if (global_ctdb_connection_pid != getpid()) {
  66                 DEBUG(0,("messaging_ctdbd_connection():"
  67                          "valid for pid[%jd] but it's [%jd]\n",
  68                          (intmax_t)global_ctdb_connection_pid,
  69                          (intmax_t)getpid()));
  70                 smb_panic("messaging_ctdbd_connection() invalid process\n");
  71         }
  72
  73         return global_ctdbd_connection;
  74 }
  75
  76 static int messaging_ctdb_send(struct server_id src,
  77                                struct server_id pid, int msg_type,
  78                                const struct iovec *iov, int iovlen,
  79                                const int *fds, size_t num_fds,
  80                                struct messaging_backend *backend)
  81 {
  82         struct messaging_ctdbd_context *ctx = talloc_get_type_abort(
  83                 backend->private_data, struct messaging_ctdbd_context);
  84         uint8_t hdr[MESSAGE_HDR_LENGTH];
  85         struct iovec iov2[iovlen+1];
  86
  87         if (num_fds > 0) {
  88                 return ENOSYS;
  89         }
  90
  91         message_hdr_put(hdr, msg_type, src, pid);
  92         iov2[0] = (struct iovec){ .iov_base = hdr, .iov_len = sizeof(hdr) };
  93         memcpy(&iov2[1], iov, iovlen * sizeof(*iov));
  94
  95         return ctdbd_messaging_send_iov(ctx->conn, pid.vnn, pid.pid,
  96                                         iov2, iovlen+1);
  97 }
  98
  99 static int messaging_ctdbd_destructor(struct messaging_ctdbd_context *ctx)
 100 {
 101         /*
 102          * The global connection just went away
 103          */
 104         global_ctdb_connection_pid = 0;
 105         global_ctdbd_connection = NULL;
 106         return 0;
 107 }
 108
 109 static int messaging_ctdb_recv(
 110         uint32_t src_vnn, uint32_t dst_vnn, uint64_t dst_srvid,
 111         const uint8_t *msg, size_t msg_len, void *private_data)
 112 {
 113         struct messaging_context *msg_ctx = talloc_get_type_abort(
 114                 private_data, struct messaging_context);
 115         struct server_id me = messaging_server_id(msg_ctx);
 116         int ret;
 117         struct iovec iov;
 118         struct server_id src, dst;
 119         enum messaging_type msg_type;
 120         struct server_id_buf idbuf;
 121
 122         if (msg_len < MESSAGE_HDR_LENGTH) {
 123                 DEBUG(1, ("%s: message too short: %u\n", __func__,
 124                           (unsigned)msg_len));
 125                 return 0;
 126         }
 127
 128         message_hdr_get(&msg_type, &src, &dst, msg);
 129
 130         iov = (struct iovec) {
 131                 .iov_base = discard_const_p(uint8_t, msg) + MESSAGE_HDR_LENGTH,
 132                 .iov_len = msg_len - MESSAGE_HDR_LENGTH
 133         };
 134
 135         DEBUG(10, ("%s: Received message 0x%x len %u from %s\n",
 136                    __func__, (unsigned)msg_type, (unsigned)msg_len,
 137                    server_id_str_buf(src, &idbuf)));
 138
 139         if (!server_id_same_process(&me, &dst)) {
 140                 struct server_id_buf id1, id2;
 141
 142                 DEBUG(10, ("%s: I'm %s, ignoring msg to %s\n", __func__,
 143                            server_id_str_buf(me, &id1),
 144                            server_id_str_buf(dst, &id2)));
 145                 return 0;
 146         }
 147
 148         /*
 149          * Go through the event loop
 150          */
 151
 152         ret = messaging_send_iov_from(msg_ctx, src, dst, msg_type,
 153                                       &iov, 1, NULL, 0);
 154
 155         if (ret != 0) {
 156                 DEBUG(10, ("%s: messaging_send_iov_from failed: %s\n",
 157                            __func__, strerror(ret)));
 158         }
 159
 160         return 0;
 161 }
 162
 163 static void messaging_ctdbd_readable(struct tevent_context *ev,
 164                                      struct tevent_fd *fde,
 165                                      uint16_t flags,
 166                                      void *private_data)
 167 {
 168         struct ctdbd_connection *conn = talloc_get_type_abort(
 169                 private_data, struct ctdbd_connection);
 170
 171         if ((flags & TEVENT_FD_READ) == 0) {
 172                 return;
 173         }
 174         ctdbd_socket_readable(conn);
 175 }
 176
 177 static int messaging_ctdbd_init_internal(struct messaging_context *msg_ctx,
 178                                          TALLOC_CTX *mem_ctx,
 179                                          struct messaging_ctdbd_context *ctx,
 180                                          bool reinit)
 181 {
 182         struct tevent_context *ev;
 183         int ret, ctdb_fd;
 184
 185         if (reinit) {
 186                 TALLOC_FREE(ctx->fde);
 187
 188                 ret = ctdbd_reinit_connection(ctx,
 189                                               lp_ctdbd_socket(),
 190                                               lp_ctdb_timeout(),
 191                                               ctx->conn);
 192                 if (ret != 0) {
 193                         DBG_ERR("ctdbd_reinit_connection failed: %s\n",
 194                                 strerror(ret));
 195                         return ret;
 196                 }
 197         } else {
 198                 ret = ctdbd_init_connection(ctx,
 199                                             lp_ctdbd_socket(),
 200                                             lp_ctdb_timeout(),
 201                                             &ctx->conn);
 202                 if (ret != 0) {
 203                         DBG_ERR("ctdbd_init_connection failed: %s\n",
 204                                 strerror(ret));
 205                         return ret;
 206                 }
 207         }
 208
 209         ret = register_with_ctdbd(ctx->conn, MSG_SRVID_SAMBA, NULL, NULL);
 210         if (ret != 0) {
 211                 DBG_DEBUG("Could not register MSG_SRVID_SAMBA: %s\n",
 212                           strerror(ret));
 213                 return ret;
 214         }
 215
 216         ret = register_with_ctdbd(ctx->conn, getpid(),
 217                                   messaging_ctdb_recv, msg_ctx);
 218         if (ret != 0) {
 219                 DEBUG(10, ("register_with_ctdbd failed: %s\n",
 220                            strerror(ret)));
 221                 return ret;
 222         }
 223
 224         ctdb_fd = ctdbd_conn_get_fd(ctx->conn);
 225         ev = messaging_tevent_context(msg_ctx);
 226
 227         ctx->fde = tevent_add_fd(ev, ctx, ctdb_fd, TEVENT_FD_READ,
 228                                  messaging_ctdbd_readable, ctx->conn);
 229         if (ctx->fde == NULL) {
 230                 return ENOMEM;
 231         }
 232
 233         global_ctdb_connection_pid = getpid();
 234         global_ctdbd_connection = ctx->conn;
 235         talloc_set_destructor(ctx, messaging_ctdbd_destructor);
 236
 237         set_my_vnn(ctdbd_vnn(ctx->conn));
 238
 239         return 0;
 240 }
 241
 242 int messaging_ctdbd_init(struct messaging_context *msg_ctx,
 243                          TALLOC_CTX *mem_ctx,
 244                          struct messaging_backend **presult)
 245 {
 246         struct messaging_backend *result;
 247         struct messaging_ctdbd_context *ctx;
 248         int ret;
 249
 250         if (!(result = talloc(mem_ctx, struct messaging_backend))) {
 251                 DEBUG(0, ("talloc failed\n"));
 252                 return ENOMEM;
 253         }
 254
 255         if (!(ctx = talloc(result, struct messaging_ctdbd_context))) {
 256                 DEBUG(0, ("talloc failed\n"));
 257                 TALLOC_FREE(result);
 258                 return ENOMEM;
 259         }
 260
 261         ret = messaging_ctdbd_init_internal(msg_ctx, mem_ctx, ctx, false);
 262         if (ret != 0) {
 263                 TALLOC_FREE(result);
 264                 return ret;
 265         }
 266
 267         result->send_fn = messaging_ctdb_send;
 268         result->private_data = (void *)ctx;
 269
 270         *presult = result;
 271         return 0;
 272 }
 273
 274 int messaging_ctdbd_reinit(struct messaging_context *msg_ctx,
 275                            TALLOC_CTX *mem_ctx,
 276                            struct messaging_backend *backend)
 277 {
 278         struct messaging_ctdbd_context *ctx = talloc_get_type_abort(
 279                 backend->private_data, struct messaging_ctdbd_context);
 280         int ret;
 281
 282         ret = messaging_ctdbd_init_internal(msg_ctx, mem_ctx, ctx, true);
 283         if (ret != 0) {
 284                 return ret;
 285         }
 286
 287         return 0;
 288 }