* refactor backend modules library interface

src/backend-test.c

@@ -90,7 +90,7 @@ int main(int argc, char *argv[]) {
   }
 
   if (!f2b_backend_start(backend)) {
-    f2b_log_msg(log_error, "action 'ban' failed: %s", f2b_backend_error(backend));
+    f2b_log_msg(log_error, "action 'ban' failed");
     goto cleanup;
   }
 
@@ -120,9 +120,7 @@ int main(int argc, char *argv[]) {
     if (handler(backend, addr)) {
       fputs("ok\n", stdout);
     } else {
-      fputs("failure: ", stdout);
-      fputs(f2b_backend_error(backend), stdout);
-      fputc('\n', stdout);
+      fputs("failure\n", stdout);
     }
   } /* while */
 

src/backend.c

@@ -36,7 +36,7 @@ f2b_backend_create(f2b_config_section_t *config, const char *id) {
     goto cleanup;
   if ((*(void **) (&backend->ready)   = dlsym(backend->h, "ready"))   == NULL)
     goto cleanup;
-  if ((*(void **) (&backend->error)   = dlsym(backend->h, "error"))   == NULL)
+  if ((*(void **) (&backend->logcb)   = dlsym(backend->h, "logcb"))   == NULL)
     goto cleanup;
   if ((*(void **) (&backend->start)   = dlsym(backend->h, "start"))   == NULL)
     goto cleanup;
@@ -58,6 +58,8 @@ f2b_backend_create(f2b_config_section_t *config, const char *id) {
     goto cleanup;
   }
 
+  backend->logcb(backend->cfg, f2b_log_mod_cb);
+
   /* try init */
   for (param = config->param; param != NULL; param = param->next) {
     if (strcmp(param->name, BACKEND_LIBRARY_PARAM) == 0)
@@ -109,7 +111,6 @@ f2b_backend_ ## CMD(f2b_backend_t *backend, const char *ip) { \
   return backend->CMD(backend->cfg, ip); \
 }
 
-BACKEND_CMD_ARG0(error, const char *)
 BACKEND_CMD_ARG0(start, bool)
 BACKEND_CMD_ARG0(stop,  bool)
 BACKEND_CMD_ARG0(ping,  bool)

src/backend.h

@@ -27,7 +27,7 @@ typedef struct f2b_backend_t {
   /** dlsym pointer to handler of @a ready command */
   bool  (*ready)   (void *cfg);
   /** dlsym pointer to handler of @a error command */
-  char *(*error)   (void *cfg);
+  void  (*logcb)   (void *cfg, void (*cb)(log_msgtype_t lvl, const char *msg));
   /** dlsym pointer to handler of @a start command */
   bool  (*start)   (void *cfg);
   /** dlsym pointer to handler of @a stop command */
@@ -58,13 +58,6 @@ f2b_backend_t * f2b_backend_create (f2b_config_section_t *config, const char *id
 void f2b_backend_destroy(f2b_backend_t *b);
 
 /* helpers */
-/**
- * @brief Get last backend error
- * @param b Pointer to backend struct
- * @returns Pointer to string with description of last error
- */
-const char *
-     f2b_backend_error (f2b_backend_t *b);
 /**
  * @brief Start given backend
  * @param b Pointer to backend struct

src/jail.c

@@ -170,8 +170,7 @@ f2b_jail_ban(f2b_jail_t *jail, f2b_ipaddr_t *addr) {
     return true;
   }
 
-  f2b_log_msg(log_error, "jail '%s': can't ban ip %s -- %s",
-    jail->name, addr->text, f2b_backend_error(jail->backend));
+  f2b_log_msg(log_error, "jail '%s': can't ban ip %s", jail->name, addr->text);
   return false;
 }
 
@@ -189,8 +188,7 @@ f2b_jail_unban(f2b_jail_t *jail, f2b_ipaddr_t *addr) {
     return true;
   }
 
-  f2b_log_msg(log_error, "jail '%s': can't release ip %s -- %s",
-    jail->name, addr->text, f2b_backend_error(jail->backend));
+  f2b_log_msg(log_error, "jail '%s': can't release ip %s", jail->name, addr->text);
   return false;
 }
 
@@ -383,8 +381,7 @@ f2b_jail_init(f2b_jail_t *jail, f2b_config_t *config) {
     goto cleanup;
   }
   if (!f2b_backend_start(jail->backend)) {
-    f2b_log_msg(log_warn, "jail '%s': backend action 'start' failed -- %s",
-      jail->name, f2b_backend_error(jail->backend));
+    f2b_log_msg(log_warn, "jail '%s': backend action 'start' failed", jail->name);
     goto cleanup;
   }
 
@@ -433,8 +430,7 @@ f2b_jail_start(f2b_jail_t *jail) {
       f2b_log_msg(log_note, "jail '%s': restored ban of ip %s (%.1fhrs remain)",
         jail->name, addr->text, (float) remains / 3600);
     } else {
-      f2b_log_msg(log_error, "jail '%s': can't ban ip %s -- %s",
-        jail->name, addr->text, f2b_backend_error(jail->backend));
+      f2b_log_msg(log_error, "jail '%s': can't ban ip %s", jail->name, addr->text);
     }
   }
 
@@ -469,8 +465,7 @@ f2b_jail_stop(f2b_jail_t *jail) {
   f2b_addrlist_destroy(jail->ipaddrs);
 
   if (!f2b_backend_stop(jail->backend)) {
-    f2b_log_msg(log_error, "jail '%s': action 'stop' for backend failed: %s",
-      jail->name, f2b_backend_error(jail->backend));
+    f2b_log_msg(log_error, "jail '%s': action 'stop' for backend failed", jail->name);
     errors = true;
   }