ctdb/event/event_daemon.c

   1 /*
   2    CTDB event daemon
   3
   4    Copyright (C) Amitay Isaacs  2018
   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 "replace.h"
  21 #include "system/filesys.h"
  22
  23 #include <popt.h>
  24 #include <talloc.h>
  25 #include <tevent.h>
  26
  27 #include "lib/util/tevent_unix.h"
  28
  29 #include "common/logging.h"
  30 #include "common/path.h"
  31 #include "common/sock_daemon.h"
  32
  33 #include "event/event_private.h"
  34
  35 struct event_daemon_state {
  36         TALLOC_CTX *mem_ctx;
  37         char *socket;
  38         char *pidfile;
  39         struct tevent_context *ev;
  40         struct event_config *config;
  41         struct sock_daemon_context *sockd;
  42         struct event_context *eventd;
  43 };
  44
  45 static int event_daemon_startup(void *private_data)
  46 {
  47         struct event_daemon_state *e_state = talloc_get_type_abort(
  48                 private_data, struct event_daemon_state);
  49         int ret;
  50
  51         ret = event_context_init(e_state,
  52                                  e_state->ev,
  53                                  e_state->config,
  54                                  &e_state->eventd);
  55         if (ret != 0) {
  56                 D_ERR("Failed to initialize event context\n");
  57                 return ret;
  58         }
  59
  60         return 0;
  61 }
  62
  63 static int event_daemon_reconfigure(void *private_data)
  64 {
  65         struct event_daemon_state *e_state = talloc_get_type_abort(
  66                 private_data, struct event_daemon_state);
  67         int ret;
  68
  69         ret = event_config_reload(e_state->config);
  70         if (ret != 0) {
  71                 D_WARNING("Configuration reload failed\n");
  72         }
  73
  74         return 0;
  75 }
  76
  77 static void event_daemon_shutdown(void *private_data)
  78 {
  79         struct event_daemon_state *e_state = talloc_get_type_abort(
  80                 private_data, struct event_daemon_state);
  81
  82         TALLOC_FREE(e_state->eventd);
  83 }
  84
  85 static bool event_client_connect(struct sock_client_context *client,
  86                                  pid_t pid,
  87                                  void *private_data)
  88 {
  89         struct event_daemon_state *e_state = talloc_get_type_abort(
  90                 private_data, struct event_daemon_state);
  91         int ret;
  92
  93         ret = eventd_client_add(e_state->eventd, client);
  94         if (ret != 0) {
  95                 D_ERR("Failed to register client, ret=%d\n", ret);
  96                 return false;
  97         }
  98
  99         return true;
 100 }
 101
 102 static void event_client_disconnect(struct sock_client_context *client,
 103                                     void *private_data)
 104 {
 105         struct event_daemon_state *e_state = talloc_get_type_abort(
 106                 private_data, struct event_daemon_state);
 107
 108         eventd_client_del(e_state->eventd, client);
 109 }
 110
 111 struct event_client_state {
 112         struct tevent_context *ev;
 113         struct event_context *eventd;
 114         struct sock_client_context *client;
 115         uint8_t *buf;
 116         size_t buflen;
 117 };
 118
 119 static void event_client_request_done(struct tevent_req *subreq);
 120 static void event_client_reply_done(struct tevent_req *subreq);
 121
 122 static struct tevent_req *event_client_send(TALLOC_CTX *mem_ctx,
 123                                             struct tevent_context *ev,
 124                                             struct sock_client_context *client,
 125                                             uint8_t *buf,
 126                                             size_t buflen,
 127                                             void *private_data)
 128 {
 129         struct event_daemon_state *e_state = talloc_get_type_abort(
 130                 private_data, struct event_daemon_state);
 131         struct tevent_req *req, *subreq;
 132         struct event_client_state *state;
 133
 134         req = tevent_req_create(mem_ctx, &state, struct event_client_state);
 135         if (req == NULL) {
 136                 return NULL;
 137         }
 138
 139         state->ev = ev;
 140         state->eventd = e_state->eventd;
 141         state->client = client;
 142
 143         subreq = event_pkt_send(state, ev, e_state->eventd, buf, buflen);
 144         if (tevent_req_nomem(subreq, req)) {
 145                 return tevent_req_post(req, ev);
 146         }
 147         tevent_req_set_callback(subreq, event_client_request_done, req);
 148
 149         return req;
 150 }
 151
 152 static void event_client_request_done(struct tevent_req *subreq)
 153 {
 154         struct tevent_req *req = tevent_req_callback_data(
 155                 subreq, struct tevent_req);
 156         struct event_client_state *state = tevent_req_data(
 157                 req, struct event_client_state);
 158         int ret = 0;
 159         bool ok;
 160
 161         ok = event_pkt_recv(subreq, &ret, state, &state->buf, &state->buflen);
 162         TALLOC_FREE(subreq);
 163         if (!ok) {
 164                 tevent_req_error(req, ret);
 165                 return;
 166         }
 167
 168         ok = eventd_client_exists(state->eventd, state->client);
 169         if (!ok) {
 170                 /* Client has already disconnected */
 171                 talloc_free(state->buf);
 172                 tevent_req_done(req);
 173                 return;
 174         }
 175
 176         subreq = sock_socket_write_send(state,
 177                                         state->ev,
 178                                         state->client,
 179                                         state->buf,
 180                                         state->buflen);
 181         if (tevent_req_nomem(subreq, req)) {
 182                 talloc_free(state->buf);
 183                 return;
 184         }
 185         tevent_req_set_callback(subreq, event_client_reply_done, req);
 186 }
 187
 188 static void event_client_reply_done(struct tevent_req *subreq)
 189 {
 190         struct tevent_req *req = tevent_req_callback_data(
 191                 subreq, struct tevent_req);
 192         struct event_client_state *state = tevent_req_data(
 193                 req, struct event_client_state);
 194         int ret = 0;
 195         bool ok;
 196
 197         talloc_free(state->buf);
 198
 199         ok = sock_socket_write_recv(subreq, &ret);
 200         TALLOC_FREE(subreq);
 201         if (!ok) {
 202                 D_ERR("Sending reply failed\n");
 203                 tevent_req_error(req, ret);
 204                 return;
 205         }
 206
 207         tevent_req_done(req);
 208 }
 209
 210 static bool event_client_recv(struct tevent_req *req, int *perr)
 211 {
 212         if (tevent_req_is_unix_error(req, perr)) {
 213                 return false;
 214         }
 215
 216         return true;
 217 }
 218
 219 static struct {
 220         int pid;
 221         int startup_fd;
 222 } options = {
 223         .pid = -1,
 224         .startup_fd = -1,
 225 };
 226
 227 struct poptOption cmdline_options[] = {
 228         POPT_AUTOHELP
 229         { "pid", 'P', POPT_ARG_INT, &options.pid, 0,
 230                 "pid to wait for", "PID" },
 231         { "startup-fd", 'S', POPT_ARG_INT, &options.startup_fd, 0,
 232                 "file descriptor to notify of successful start", "FD" },
 233         POPT_TABLEEND
 234 };
 235
 236 int main(int argc, const char **argv)
 237 {
 238         poptContext pc;
 239         struct event_daemon_state *e_state;
 240         struct sock_daemon_funcs daemon_funcs;
 241         struct sock_socket_funcs socket_funcs;
 242         const char *log_location = "file:";
 243         const char *log_level = "NOTICE";
 244         const char *t;
 245         int interactive = 0;
 246         int opt, ret;
 247         bool ok;
 248
 249         pc = poptGetContext(argv[0],
 250                             argc,
 251                             argv,
 252                             cmdline_options,
 253                             0);
 254         while ((opt = poptGetNextOpt(pc)) != -1) {
 255                 D_ERR("Invalid options %s: %s\n",
 256                       poptBadOption(pc, 0),
 257                       poptStrerror(opt));
 258                 exit(1);
 259         }
 260
 261         t = getenv("CTDB_INTERACTIVE");
 262         if (t != NULL) {
 263                 interactive = 1;
 264         }
 265
 266         e_state = talloc_zero(NULL, struct event_daemon_state);
 267         if (e_state == NULL) {
 268                 D_ERR("Memory allocation error\n");
 269                 ret = 1;
 270                 goto fail;
 271         }
 272
 273         e_state->mem_ctx = talloc_new(e_state);
 274         if (e_state->mem_ctx == NULL) {
 275                 D_ERR("Memory allocation error\n");
 276                 ret = 1;
 277                 goto fail;
 278         }
 279
 280         e_state->socket = path_socket(e_state, "eventd");
 281         if (e_state->socket == NULL) {
 282                 D_ERR("Memory allocation error\n");
 283                 ret = 1;
 284                 goto fail;
 285         }
 286
 287         e_state->pidfile = path_pidfile(e_state, "eventd");
 288         if (e_state->pidfile == NULL) {
 289                 D_ERR("Memory allocation error\n");
 290                 ret = 1;
 291                 goto fail;
 292         }
 293
 294         ret = event_config_init(e_state, &e_state->config);
 295         if (ret != 0) {
 296                 D_ERR("Failed to initialize event config\n");
 297                 goto fail;
 298         }
 299
 300         e_state->ev = tevent_context_init(e_state->mem_ctx);
 301         if (e_state->ev == NULL) {
 302                 D_ERR("Failed to initialize tevent\n");
 303                 ret = 1;
 304                 goto fail;
 305         }
 306
 307         daemon_funcs = (struct sock_daemon_funcs) {
 308                 .startup = event_daemon_startup,
 309                 .reconfigure = event_daemon_reconfigure,
 310                 .shutdown = event_daemon_shutdown,
 311         };
 312
 313         if (interactive == 0) {
 314                 log_location = event_config_log_location(e_state->config);
 315                 log_level = event_config_log_level(e_state->config);
 316         }
 317
 318         ret = sock_daemon_setup(e_state->mem_ctx,
 319                                 "ctdb-eventd",
 320                                 log_location,
 321                                 log_level,
 322                                 &daemon_funcs,
 323                                 e_state,
 324                                 &e_state->sockd);
 325         if (ret != 0) {
 326                 D_ERR("Failed to setup sock daemon\n");
 327                 goto fail;
 328         }
 329
 330         socket_funcs = (struct sock_socket_funcs) {
 331                 .connect = event_client_connect,
 332                 .disconnect = event_client_disconnect,
 333                 .read_send = event_client_send,
 334                 .read_recv = event_client_recv,
 335         };
 336
 337         ret = sock_daemon_add_unix(e_state->sockd,
 338                                    e_state->socket,
 339                                    &socket_funcs,
 340                                    e_state);
 341         if (ret != 0) {
 342                 D_ERR("Failed to setup socket %s\n", e_state->socket);
 343                 goto fail;
 344         }
 345
 346         if (options.startup_fd != -1) {
 347                 ok = sock_daemon_set_startup_fd(e_state->sockd,
 348                                                 options.startup_fd);
 349                 if (!ok) {
 350                         goto fail;
 351                 }
 352         }
 353
 354         ret = sock_daemon_run(e_state->ev,
 355                               e_state->sockd,
 356                               e_state->pidfile,
 357                               false,
 358                               false,
 359                               options.pid);
 360         if (ret == EINTR) {
 361                 ret = 0;
 362         }
 363
 364         if (t != NULL) {
 365                 talloc_report_full(e_state->mem_ctx, stderr);
 366         }
 367
 368 fail:
 369         talloc_free(e_state);
 370         (void)poptFreeContext(pc);
 371         exit(ret);
 372 }