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
  25 #include "ctdb.h"
  26 #include "ctdb_private.h"
  27 #include "ctdbd_conn.h"
  28
  29
  30 struct messaging_ctdbd_context {
  31         struct ctdbd_connection *conn;
  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                 }
  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         struct messaging_rec msg;
  84         uint8_t *buf;
  85         ssize_t buflen;
  86         NTSTATUS status;
  87
  88         if (num_fds > 0) {
  89                 return ENOSYS;
  90         }
  91
  92         buflen = iov_buflen(iov, iovlen);
  93         if (buflen == -1) {
  94                 return EMSGSIZE;
  95         }
  96
  97         buf = talloc_array(talloc_tos(), uint8_t, buflen);
  98         if (buf == NULL) {
  99                 return ENOMEM;
 100         }
 101         iov_buf(iov, iovlen, buf, buflen);
 102
 103         msg = (struct messaging_rec) {
 104                 .msg_version    = MESSAGE_VERSION,
 105                 .msg_type       = msg_type,
 106                 .dest           = pid,
 107                 .src            = src,
 108                 .buf            = data_blob_const(buf, talloc_get_size(buf)),
 109         };
 110
 111         status = ctdbd_messaging_send(ctx->conn, pid.vnn, pid.pid, &msg);
 112
 113         TALLOC_FREE(buf);
 114
 115         if (NT_STATUS_IS_OK(status)) {
 116                 return 0;
 117         }
 118         return map_errno_from_nt_status(status);
 119 }
 120
 121 static int messaging_ctdbd_destructor(struct messaging_ctdbd_context *ctx)
 122 {
 123         /*
 124          * The global connection just went away
 125          */
 126         global_ctdb_connection_pid = 0;
 127         global_ctdbd_connection = NULL;
 128         return 0;
 129 }
 130
 131 static struct messaging_rec *ctdb_pull_messaging_rec(
 132         TALLOC_CTX *mem_ctx, const struct ctdb_req_message *msg)
 133 {
 134         struct messaging_rec *result;
 135         DATA_BLOB blob;
 136         enum ndr_err_code ndr_err;
 137         size_t len = msg->hdr.length;
 138
 139         if (len < offsetof(struct ctdb_req_message, data)) {
 140                 return NULL;
 141         }
 142         len -= offsetof(struct ctdb_req_message, data);
 143
 144         if (len < msg->datalen) {
 145                 return NULL;
 146         }
 147
 148         result = talloc(mem_ctx, struct messaging_rec);
 149         if (result == NULL) {
 150                 return NULL;
 151         }
 152
 153         blob = data_blob_const(msg->data, msg->datalen);
 154
 155         ndr_err = ndr_pull_struct_blob_all(
 156                 &blob, result, result,
 157                 (ndr_pull_flags_fn_t)ndr_pull_messaging_rec);
 158
 159         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 160                 DEBUG(0, ("ndr_pull_struct_blob failed: %s\n",
 161                           ndr_errstr(ndr_err)));
 162                 TALLOC_FREE(result);
 163                 return NULL;
 164         }
 165
 166         if (DEBUGLEVEL >= 11) {
 167                 DEBUG(11, ("ctdb_pull_messaging_rec:\n"));
 168                 NDR_PRINT_DEBUG(messaging_rec, result);
 169         }
 170
 171         return result;
 172 }
 173
 174 static void messaging_ctdb_recv(struct ctdb_req_message *msg,
 175                                 void *private_data)
 176 {
 177         struct messaging_context *msg_ctx = talloc_get_type_abort(
 178                 private_data, struct messaging_context);
 179         struct server_id me = messaging_server_id(msg_ctx);
 180         struct messaging_rec *rec;
 181         NTSTATUS status;
 182         struct iovec iov;
 183
 184         rec = ctdb_pull_messaging_rec(msg_ctx, msg);
 185         if (rec == NULL) {
 186                 DEBUG(10, ("%s: ctdb_pull_messaging_rec failed\n", __func__));
 187                 return;
 188         }
 189
 190         if (!server_id_same_process(&me, &rec->dest)) {
 191                 struct server_id_buf id1, id2;
 192
 193                 DEBUG(10, ("%s: I'm %s, ignoring msg to %s\n", __func__,
 194                            server_id_str_buf(me, &id1),
 195                            server_id_str_buf(rec->dest, &id2)));
 196                 TALLOC_FREE(rec);
 197                 return;
 198         }
 199
 200         iov = (struct iovec) { .iov_base = rec->buf.data,
 201                                .iov_len = rec->buf.length };
 202
 203         status = messaging_send_iov_from(msg_ctx, rec->src, rec->dest,
 204                                          rec->msg_type, &iov, 1, NULL, 0);
 205         TALLOC_FREE(rec);
 206
 207         if (!NT_STATUS_IS_OK(status)) {
 208                 DEBUG(10, ("%s: messaging_send_iov_from failed: %s\n",
 209                            __func__, nt_errstr(status)));
 210         }
 211 }
 212
 213 NTSTATUS messaging_ctdbd_init(struct messaging_context *msg_ctx,
 214                               TALLOC_CTX *mem_ctx,
 215                               struct messaging_backend **presult)
 216 {
 217         struct messaging_backend *result;
 218         struct messaging_ctdbd_context *ctx;
 219         NTSTATUS status;
 220
 221         if (!(result = talloc(mem_ctx, struct messaging_backend))) {
 222                 DEBUG(0, ("talloc failed\n"));
 223                 return NT_STATUS_NO_MEMORY;
 224         }
 225
 226         if (!(ctx = talloc(result, struct messaging_ctdbd_context))) {
 227                 DEBUG(0, ("talloc failed\n"));
 228                 TALLOC_FREE(result);
 229                 return NT_STATUS_NO_MEMORY;
 230         }
 231
 232         status = ctdbd_messaging_connection(ctx, &ctx->conn);
 233
 234         if (!NT_STATUS_IS_OK(status)) {
 235                 DEBUG(10, ("ctdbd_messaging_connection failed: %s\n",
 236                            nt_errstr(status)));
 237                 TALLOC_FREE(result);
 238                 return status;
 239         }
 240
 241         status = ctdbd_register_msg_ctx(ctx->conn, msg_ctx);
 242
 243         if (!NT_STATUS_IS_OK(status)) {
 244                 DEBUG(10, ("ctdbd_register_msg_ctx failed: %s\n",
 245                            nt_errstr(status)));
 246                 TALLOC_FREE(result);
 247                 return status;
 248         }
 249
 250         status = register_with_ctdbd(ctx->conn, getpid(),
 251                                      messaging_ctdb_recv, msg_ctx);
 252
 253         global_ctdb_connection_pid = getpid();
 254         global_ctdbd_connection = ctx->conn;
 255         talloc_set_destructor(ctx, messaging_ctdbd_destructor);
 256
 257         set_my_vnn(ctdbd_vnn(ctx->conn));
 258
 259         result->send_fn = messaging_ctdb_send;
 260         result->private_data = (void *)ctx;
 261
 262         *presult = result;
 263         return NT_STATUS_OK;
 264 }