* add draft for backend/mcast

src/backends/mcast.c

@@ -0,0 +1,164 @@
+/* Copyright 2016 Alex 'AdUser' Z (ad_user@runbox.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <netdb.h>
+
+#include "../strlcpy.h"
+#include "../commands.h"
+#include "../cmsg.h"
+#include "../csocket.h"
+
+#include "backend.h"
+#include "shared.c"
+
+#define DEFAULT_MCAST_ADDR "239.255.186.1"
+#define DEFAULT_MCAST_PORT "3370"
+
+struct _config {
+  char name[ID_MAX + 1];
+  char error[256];
+  bool shared;
+  char maddr[INET_ADDRSTRLEN];  /**< multicast address */
+  char mport[6];                /**< multicast port */
+  char iface[IF_NAMESIZE];      /**< bind interface */
+  int sock;
+};
+
+cfg_t *
+create(const char *id) {
+  cfg_t *cfg = NULL;
+
+  assert(id != NULL);
+
+  if ((cfg = calloc(1, sizeof(cfg_t))) == NULL)
+    return NULL;
+  strlcpy(cfg->name, id, sizeof(cfg->name));
+  strlcpy(cfg->maddr, DEFAULT_MCAST_ADDR, sizeof(cfg->maddr));
+  strlcpy(cfg->mport, DEFAULT_MCAST_PORT, sizeof(cfg->mport));
+
+  return cfg;
+}
+
+bool
+config(cfg_t *cfg, const char *key, const char *value) {
+  assert(cfg != NULL);
+  assert(key != NULL);
+  assert(value != NULL);
+
+  if (strcmp(key, "group") == 0) {
+    if (strncmp(value, "239.255.", 8) != 0) {
+      strlcpy(cfg->error, "mcast group address should be inside 239.255.0.0/16 block", sizeof(cfg->error));
+      return false;
+    }
+    strlcpy(cfg->maddr, value, sizeof(cfg->maddr));
+    return true;
+  }
+  if (strcmp(key, "port") == 0) {
+    strlcpy(cfg->mport, value, sizeof(cfg->mport));
+    return true;
+  }
+  if (strcmp(key, "iface") == 0) {
+    strlcpy(cfg->iface, value, sizeof(cfg->iface));
+    return true;
+  }
+
+  return false;
+}
+
+bool
+ready(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  if (cfg->maddr[0] && cfg->mport[0])
+    return true;
+
+  return false;
+}
+
+char *
+error(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  return cfg->error;
+}
+
+bool
+start(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  if (cfg->shared && usage_inc(cfg->name) > 1)
+    return true;
+
+  /* TODO */
+
+  return true;
+}
+
+bool
+stop(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  if (cfg->shared && usage_dec(cfg->name) > 0)
+    return true;
+
+  close(cfg->sock);
+  cfg->sock = -1;
+
+  return true;
+}
+
+bool
+ban(cfg_t *cfg, const char *ip) {
+  assert(cfg != NULL);
+
+  /* TODO */
+
+  return false;
+}
+
+bool
+unban(cfg_t *cfg, const char *ip) {
+  assert(cfg != NULL);
+
+  (void)(ip); /* suppress warning for unused variable 'ip' */
+  return true;
+}
+
+bool
+check(cfg_t *cfg, const char *ip) {
+  assert(cfg != NULL);
+
+  (void)(ip); /* suppress warning for unused variable 'ip' */
+  return false;
+}
+
+bool
+ping(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  /* TODO */
+
+  return false;
+}
+
+void
+destroy(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  free(cfg);
+}