* add draft of ipset backend

src/backends/ipset.c

@@ -0,0 +1,170 @@
+/* Copyright 2017 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 <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <libipset/session.h>
+#include <libipset/types.h>
+#include <libipset/ui.h>
+
+#include "../strlcpy.h"
+
+#include "backend.h"
+#include "shared.c"
+
+struct _config {
+  char name[ID_MAX + 1];
+  char error[256];
+  bool shared;
+  struct ipset_session *sess;
+};
+
+inline static bool
+my_ipset_error(cfg_t *cfg) {
+  snprintf(cfg->error, sizeof(cfg->error), "ipset: %s",
+    ipset_session_error(cfg->sess));
+  return false;
+}
+
+static bool
+my_ipset_cmd(cfg_t *cfg, enum ipset_cmd cmd, const char *ip) {
+  const struct ipset_type *type = NULL;
+
+  if ((type = ipset_type_get(cfg->sess, cmd)) == NULL)
+    return my_ipset_error(cfg);
+
+  if (ipset_parse_elem(cfg->sess, type->last_elem_optional, ip) < 0)
+    return my_ipset_error(cfg);
+
+  if (ipset_cmd(cfg->sess, cmd, 0) < 0)
+    return my_ipset_error(cfg);
+
+  return true;
+}
+
+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));
+
+  return cfg;
+}
+
+bool
+config(cfg_t *cfg, const char *key, const char *value) {
+  assert(cfg != NULL);
+  assert(key != NULL);
+  assert(value != NULL);
+
+  (void)(cfg);
+  (void)(key);
+  (void)(value);
+
+  return false;
+}
+
+bool
+ready(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  if (cfg->name[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;
+
+  ipset_load_types();
+
+  if ((cfg->sess = ipset_session_init(printf)) == NULL) {
+    strlcpy(cfg->error, "can't init ipset session", sizeof(cfg->error));
+    return false;
+  }
+
+  if (ipset_envopt_parse(cfg->sess, IPSET_ENV_EXIST, NULL) < 0)
+    return my_ipset_error(cfg);
+
+  if (ipset_parse_setname(cfg->sess, IPSET_SETNAME, cfg->name) < 0)
+    return my_ipset_error(cfg);
+
+  return true;
+}
+
+bool
+stop(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  if (cfg->shared && usage_dec(cfg->name) > 0)
+    return true;
+
+  if (cfg->sess) {
+    ipset_session_fini(cfg->sess);
+    cfg->sess = NULL;
+  }
+
+  return true;
+}
+
+bool
+ban(cfg_t *cfg, const char *ip) {
+  assert(cfg != NULL);
+
+  return my_ipset_cmd(cfg, IPSET_CMD_ADD, ip);
+}
+
+bool
+unban(cfg_t *cfg, const char *ip) {
+  assert(cfg != NULL);
+
+  return my_ipset_cmd(cfg, IPSET_CMD_DEL, ip);
+}
+
+bool
+check(cfg_t *cfg, const char *ip) {
+  assert(cfg != NULL);
+
+  return my_ipset_cmd(cfg, IPSET_CMD_TEST, ip);
+}
+
+bool
+ping(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  (void)(cfg); /* silence warning about unused variable */
+
+  return true;
+}
+
+void
+destroy(cfg_t *cfg) {
+  assert(cfg != NULL);
+
+  free(cfg);
+}