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
  27
  28 struct messaging_ctdbd_context {
  29         struct ctdbd_connection *conn;
  30 };
  31
  32 /*
  33  * This is a Samba3 hack/optimization. Routines like process_exists need to
  34  * talk to ctdbd, and they don't get handed a messaging context.
  35  */
  36 static struct ctdbd_connection *global_ctdbd_connection;
  37 static int global_ctdb_connection_pid;
  38
  39 struct ctdbd_connection *messaging_ctdbd_connection(void)
  40 {
  41         if (!lp_clustering()) {
  42                 return NULL;
  43         }
  44
  45         if (global_ctdb_connection_pid == 0 &&
  46             global_ctdbd_connection == NULL) {
  47                 struct tevent_context *ev;
  48                 struct messaging_context *msg;
  49
  50                 ev = samba_tevent_context_init(NULL);
  51                 if (!ev) {
  52                         DEBUG(0,("samba_tevent_context_init failed\n"));
  53                         return NULL;
  54                 }
  55
  56                 msg = messaging_init(NULL, ev);
  57                 if (!msg) {
  58                         DEBUG(0,("messaging_init failed\n"));
  59                         return NULL;
  60                 }
  61         }
  62
  63         if (global_ctdb_connection_pid != getpid()) {
  64                 DEBUG(0,("messaging_ctdbd_connection():"
  65                          "valid for pid[%jd] but it's [%jd]\n",
  66                          (intmax_t)global_ctdb_connection_pid,
  67                          (intmax_t)getpid()));
  68                 smb_panic("messaging_ctdbd_connection() invalid process\n");
  69         }
  70
  71         return global_ctdbd_connection;
  72 }
  73
  74 static int messaging_ctdb_send(struct server_id src,
  75                                struct server_id pid, int msg_type,
  76                                const struct iovec *iov, int iovlen,
  77                                const int *fds, size_t num_fds,
  78                                struct messaging_backend *backend)
  79 {
  80         struct messaging_ctdbd_context *ctx = talloc_get_type_abort(
  81                 backend->private_data, struct messaging_ctdbd_context);
  82         uint8_t hdr[MESSAGE_HDR_LENGTH];
  83         struct iovec iov2[iovlen+1];
  84         NTSTATUS status;
  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         status = ctdbd_messaging_send_iov(ctx->conn, pid.vnn, pid.pid,
  95                                           iov2, iovlen+1);
  96         if (NT_STATUS_IS_OK(status)) {
  97                 return 0;
  98         }
  99         return map_errno_from_nt_status(status);
 100 }
 101
 102 static int messaging_ctdbd_destructor(struct messaging_ctdbd_context *ctx)
 103 {
 104         /*
 105          * The global connection just went away
 106          */
 107         global_ctdb_connection_pid = 0;
 108         global_ctdbd_connection = NULL;
 109         return 0;
 110 }
 111
 112 static void messaging_ctdb_recv(
 113         uint32_t src_vnn, uint32_t dst_vnn, uint64_t dst_srvid,
 114         const uint8_t *msg, size_t msg_len, void *private_data)
 115 {
 116         struct messaging_context *msg_ctx = talloc_get_type_abort(
 117                 private_data, struct messaging_context);
 118         struct server_id me = messaging_server_id(msg_ctx);
 119         NTSTATUS status;
 120         struct iovec iov;
 121         struct server_id src, dst;
 122         enum messaging_type msg_type;
 123         struct server_id_buf idbuf;
 124
 125         if (msg_len < MESSAGE_HDR_LENGTH) {
 126                 DEBUG(1, ("%s: message too short: %u\n", __func__,
 127                           (unsigned)msg_len));
 128                 return;
 129         }
 130
 131         message_hdr_get(&msg_type, &src, &dst, msg);
 132
 133         iov = (struct iovec) {
 134                 .iov_base = discard_const_p(uint8_t, msg) + MESSAGE_HDR_LENGTH,
 135                 .iov_len = msg_len - MESSAGE_HDR_LENGTH
 136         };
 137
 138         DEBUG(10, ("%s: Received message 0x%x len %u from %s\n",
 139                    __func__, (unsigned)msg_type, (unsigned)msg_len,
 140                    server_id_str_buf(src, &idbuf)));
 141
 142         if (!server_id_same_process(&me, &dst)) {
 143                 struct server_id_buf id1, id2;
 144
 145                 DEBUG(10, ("%s: I'm %s, ignoring msg to %s\n", __func__,
 146                            server_id_str_buf(me, &id1),
 147                            server_id_str_buf(dst, &id2)));
 148                 return;
 149         }
 150
 151         /*
 152          * Go through the event loop
 153          */
 154
 155         status = messaging_send_iov_from(msg_ctx, src, dst, msg_type,
 156                                          &iov, 1, NULL, 0);
 157
 158         if (!NT_STATUS_IS_OK(status)) {
 159                 DEBUG(10, ("%s: messaging_send_iov_from failed: %s\n",
 160                            __func__, nt_errstr(status)));
 161         }
 162 }
 163
 164 NTSTATUS messaging_ctdbd_init(struct messaging_context *msg_ctx,
 165                               TALLOC_CTX *mem_ctx,
 166                               struct messaging_backend **presult)
 167 {
 168         struct messaging_backend *result;
 169         struct messaging_ctdbd_context *ctx;
 170         NTSTATUS status;
 171
 172         if (!(result = talloc(mem_ctx, struct messaging_backend))) {
 173                 DEBUG(0, ("talloc failed\n"));
 174                 return NT_STATUS_NO_MEMORY;
 175         }
 176
 177         if (!(ctx = talloc(result, struct messaging_ctdbd_context))) {
 178                 DEBUG(0, ("talloc failed\n"));
 179                 TALLOC_FREE(result);
 180                 return NT_STATUS_NO_MEMORY;
 181         }
 182
 183         status = ctdbd_messaging_connection(ctx, &ctx->conn);
 184
 185         if (!NT_STATUS_IS_OK(status)) {
 186                 DEBUG(10, ("ctdbd_messaging_connection failed: %s\n",
 187                            nt_errstr(status)));
 188                 TALLOC_FREE(result);
 189                 return status;
 190         }
 191
 192         status = ctdbd_register_msg_ctx(ctx->conn, msg_ctx);
 193
 194         if (!NT_STATUS_IS_OK(status)) {
 195                 DEBUG(10, ("ctdbd_register_msg_ctx failed: %s\n",
 196                            nt_errstr(status)));
 197                 TALLOC_FREE(result);
 198                 return status;
 199         }
 200
 201         status = register_with_ctdbd(ctx->conn, getpid(),
 202                                      messaging_ctdb_recv, msg_ctx);
 203
 204         global_ctdb_connection_pid = getpid();
 205         global_ctdbd_connection = ctx->conn;
 206         talloc_set_destructor(ctx, messaging_ctdbd_destructor);
 207
 208         set_my_vnn(ctdbd_vnn(ctx->conn));
 209
 210         result->send_fn = messaging_ctdb_send;
 211         result->private_data = (void *)ctx;
 212
 213         *presult = result;
 214         return NT_STATUS_OK;
 215 }