From 3c0c42d2319f3b8aeeafa96fa0202602c376c0be Mon Sep 17 00:00:00 2001
From: Alex 'AdUser' Z <ad_user@runbox.com>
Date: Wed, 2 Mar 2016 15:44:10 +1000
Subject: [PATCH] + src/backend.[ch] : add draft of code

---
 src/backend.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/backend.h | 19 +++++++++++++++
 2 files changed, 85 insertions(+)
 create mode 100644 src/backend.c
 create mode 100644 src/backend.h

diff --git a/src/backend.c b/src/backend.c
new file mode 100644
index 0000000..7463391
--- /dev/null
+++ b/src/backend.c
@@ -0,0 +1,66 @@
+#include "common.h"
+#include "backend.h"
+
+#define BACKEND_LIBRARY_PARAM "load"
+
+f2b_backend_t *
+f2b_backend_create(f2b_config_section_t *config) {
+  f2b_config_param_t *param = NULL;
+  f2b_backend_t *backend = NULL;
+  int flags = RTLD_NOW | RTLD_LOCAL;
+
+  assert(config != NULL);
+  assert(config->type == t_backend);
+
+  f2b_config_find_param(config->param, BACKEND_LIBRARY_PARAM);
+  if (!param)
+    return NULL;
+
+  if ((backend = calloc(1, sizeof(f2b_backend_t))) == NULL)
+    return NULL;
+
+  if ((backend->h = dlopen(param->value, flags)) == NULL)
+     goto cleanup;
+  if ((*(void **) (&backend->init)   = dlsym(backend->h, "init"))   == NULL)
+    goto cleanup;
+  if ((*(void **) (&backend->ready)  = dlsym(backend->h, "ready"))  == NULL)
+    goto cleanup;
+  if ((*(void **) (&backend->ban)    = dlsym(backend->h, "ban"))    == NULL)
+    goto cleanup;
+  if ((*(void **) (&backend->unban)  = dlsym(backend->h, "unban"))  == NULL)
+    goto cleanup;
+  if ((*(void **) (&backend->exists) = dlsym(backend->h, "exists")) == NULL)
+    goto cleanup;
+
+  if (backend->ready)
+    return backend;
+
+  /* try init */
+  for (; param != NULL; param = param->next) {
+    if (strcmp(param->name, BACKEND_LIBRARY_PARAM) == 0)
+      continue;
+    if (!backend->init(param->name, param->value)) {
+      f2b_log_msg(log_warn, "param pair not accepted by backend '%s': %s=%s",
+        config->name, param->name, param->value);
+    }
+  }
+
+  if (backend->ready)
+    return backend;
+
+  /* still not ready */
+  f2b_log_msg(log_error, "backend '%s' not fully configured", config->name);
+
+  cleanup:
+  if (backend->h)
+    dlclose(backend->h);
+  free(backend);
+  return NULL;
+}
+
+void
+f2b_backend_destroy(f2b_backend_t *backend) {
+  assert(backend != NULL);
+  dlclose(backend->h);
+  free(backend);
+}
diff --git a/src/backend.h b/src/backend.h
new file mode 100644
index 0000000..3edbb11
--- /dev/null
+++ b/src/backend.h
@@ -0,0 +1,19 @@
+#ifndef BACKEND_H_
+#define BACKEND_H_
+
+#include "config.h"
+#include "log.h"
+
+typedef struct f2b_backend_t {
+  void *h;
+  bool (*init)  (const char *key, const char *value);
+  bool (*ready) (void);
+  bool (*ban)   (const char *ip);
+  bool (*unban) (const char *ip);
+  bool (*exists)(const char *ip);
+} f2b_backend_t;
+
+f2b_backend_t * f2b_backend_create (f2b_config_section_t *config);
+void            f2b_backend_destroy(f2b_backend_t *backend);
+
+#endif /* BACKEND_H_ */