* refactor filter modules for new library interface

src/filters/filter.c

@@ -0,0 +1,36 @@
+/* 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.
+ */
+
+static void
+logcb_stub(enum loglevel lvl, const char *str) {
+  assert(str != NULL);
+  (void)(lvl);
+  (void)(str);
+}
+
+__attribute__ ((format (printf, 3, 4)))
+static void
+log_msg(const cfg_t *cfg, enum loglevel lvl, const char *format, ...) {
+  char buf[4096] = "";
+  va_list args;
+  size_t len;
+
+  len = snprintf(buf, sizeof(buf), "filter/%s ", MODNAME);
+  va_start(args, format);
+  vsnprintf(buf + len, sizeof(buf) - len, format, args);
+  va_end(args);
+
+  cfg->logcb(lvl, buf);
+}
+
+void
+logcb(cfg_t *cfg, void (*cb)(enum loglevel lvl, const char *msg)) {
+  assert(cfg != NULL);
+  assert(cb  != NULL);
+
+  cfg->logcb = cb;
+}

src/filters/filter.h

@@ -11,10 +11,20 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdarg.h>
 #include <string.h>
 
 #include "../strlcpy.h"
 
+enum loglevel {
+  debug  = 0,
+  info   = 1,
+  notice = 2,
+  warn   = 3,
+  error  = 4,
+  fatal  = 5,
+}; /* see log.h */
+
 /**
  * @file
  * This header describes module API of type 'filter'
@@ -31,16 +41,14 @@
  *   f2b =>  filter [label="config(cfg, param, value)"];
  *   f2b <<  filter [label="true"];
  *   f2b =>  filter [label="config(cfg, param, value)"];
+ *   f2b <<= filter [label="logcb(level, char *msg)"];
  *   f2b <<  filter [label="false"];
- *   f2b =>  filter [label="error(cfg)"];
- *   f2b <<  filter [label="const char *error"];
  *       ---        [label="filter is ready for append()"];
  *   f2b =>  filter [label="append(cfg, pattern)"];
  *   f2b <<  filter [label="true"];
  *   f2b =>  filter [label="append(cfg, pattern)"];
+ *   f2b <<= filter [label="logcb(level, char *msg)"];
  *   f2b <<  filter [label="false"];
- *   f2b =>  filter [label="error(cfg)"];
- *   f2b <<  filter [label="const char *error"];
  *       |||        [label="more calls of append()"];
  *   f2b =>  filter [label="ready(cfg)"];
  *   f2b <<  filter [label="true"];
@@ -92,27 +100,19 @@ typedef struct _config cfg_t;
  * @returns Opaque module handler or NULL on failure
  */
 extern cfg_t *create(const char *id);
-/**
- * @brief Returns last error description
- * @param cfg Module handler
- * @returns Pointer to string with description of last error
- * @note Returned pointer not marked with const, because libdl complains,
- *       but contents on pointer should not be modified or written in any way
- */
-extern const char *error(cfg_t *cfg);
 /**
  * @brief Contigure module instance
  * @param cfg Module handler
  * @param key Parameter name
  * @param value Parameter value
- * @returns true on success, false on error with setting intenal error buffer
+ * @returns true on success, false on error
  */
 extern bool   config(cfg_t *cfg, const char *key, const char *value);
 /**
  * @brief Add match pattern
  * @param cfg Module handler
  * @param pattern Regex expression
- * @returns true on success, false on error with setting intenal error buffer
+ * @returns true on success, false on error
  */
 extern bool   append(cfg_t *cfg, const char *pattern);
 /**
@@ -121,6 +121,13 @@ extern bool   append(cfg_t *cfg, const char *pattern);
  * @returns true if ready, false if not
  */
 extern bool    ready(cfg_t *cfg);
+/**
+ * @brief Sets the log callback
+ * @param cfg Module handler
+ * @param cb Logging callback
+ * @note Optional, if this function is not called, warnings/errors of module will be suppressed
+ */
+extern void    logcb(cfg_t *cfg, void (*cb)(enum loglevel l, const char *msg));
 /**
  * @brief Fetch match stats by-pattern
  * @param cfg Module handler

src/filters/pcre.c

@@ -4,10 +4,10 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-#include "filter.h"
-
 #include <pcre.h>
 
+#include "filter.h"
+#define MODNAME "pcre"
 #define HOST_REGEX "(?<host>[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3})"
 
 typedef struct f2b_regex_t {
@@ -20,7 +20,7 @@ typedef struct f2b_regex_t {
 
 struct _config {
   char id[ID_MAX];
-  char error[256];
+  void (*logcb)(enum loglevel lvl, const char *msg);
   bool icase;
   bool study;
   bool usejit;
@@ -28,6 +28,8 @@ struct _config {
   f2b_regex_t *statp;
 };
 
+#include "filter.c"
+
 cfg_t *
 create(const char *id) {
   cfg_t *cfg = NULL;
@@ -36,6 +38,7 @@ create(const char *id) {
     return NULL;
   strlcpy(cfg->id, id, sizeof(cfg->id));
 
+  cfg->logcb = &logcb_stub;
   return cfg;
 }
 
@@ -58,7 +61,7 @@ config(cfg_t *cfg, const char *key, const char *value) {
 #ifndef PCRE_CONFIG_JIT
     if (cfg->usejit) {
       cfg->usejit = false;
-      strlcpy(cfg->error, "seems like your pcre library doesn't support jit")
+      log_msg(cfg, error, "seems like your pcre library doesn't support jit");
       return false;
     }
 #endif
@@ -99,7 +102,7 @@ append(cfg_t *cfg, const char *pattern) {
     return false;
 
   if ((regex->regex = pcre_compile(buf, flags, &errptr, &erroffset, NULL)) == NULL) {
-    snprintf(cfg->error, sizeof(cfg->error), "regex compilation failed at %d: %s", erroffset, errptr);
+    log_msg(cfg, error, "regex compilation failed at %d: %s", erroffset, errptr);
     free(regex);
     return false;
   }
@@ -111,7 +114,7 @@ append(cfg_t *cfg, const char *pattern) {
       flags |= PCRE_STUDY_JIT_COMPILE;
 #endif
     if ((regex->data = pcre_study(regex->regex, 0, &errptr)) == NULL) {
-      snprintf(cfg->error, sizeof(cfg->error), "regex learn failed: %s", errptr);
+      log_msg(cfg, error, "regex learn failed: %s", errptr);
       pcre_free(regex->regex);
       free(regex);
       return false;
@@ -149,13 +152,6 @@ stats(cfg_t *cfg, int *matches, char **pattern, bool reset) {
   return false;
 }
 
-const char *
-error(cfg_t *cfg) {
-  assert(cfg != NULL);
-
-  return cfg->error;
-}
-
 bool
 match(cfg_t *cfg, const char *line, char *buf, size_t buf_size) {
   f2b_regex_t *r = NULL;
@@ -173,7 +169,7 @@ match(cfg_t *cfg, const char *line, char *buf, size_t buf_size) {
     if (rc < 0 && rc == PCRE_ERROR_NOMATCH)
       continue;
     if (rc < 0) {
-      snprintf(cfg->error, sizeof(cfg->error), "matched failed with error: %d", rc);
+      log_msg(cfg, error, "matched failed with error: %d", rc);
       continue;
     }
     /* matched */
@@ -181,7 +177,7 @@ match(cfg_t *cfg, const char *line, char *buf, size_t buf_size) {
     sc = (rc) ? rc : OVECSIZE / 3;
     rc = pcre_copy_named_substring(r->regex, line, ovector, sc, "host", buf, buf_size);
     if (rc < 0) {
-      snprintf(cfg->error, sizeof(cfg->error), "can't copy matched string: %d", rc);
+      log_msg(cfg, error, "can't copy matched string: %d", rc);
       continue;
     }
     return true;

src/filters/preg.c

@@ -4,10 +4,11 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-#include "filter.h"
-
 #include <regex.h>
 
+#include "filter.h"
+
+#define MODNAME "preg"
 /* draft */
 #define HOST_REGEX "([0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3})"
 
@@ -20,12 +21,14 @@ typedef struct f2b_regex_t {
 
 struct _config {
   char id[ID_MAX];
-  char error[256];
   bool icase;
+  void (*logcb)(enum loglevel lvl, const char *msg);
   f2b_regex_t *regexps;
   f2b_regex_t *statp;
 };
 
+#include "filter.c"
+
 cfg_t *
 create(const char *id) {
   cfg_t *cfg = NULL;
@@ -34,6 +37,7 @@ create(const char *id) {
     return NULL;
   strlcpy(cfg->id, id, sizeof(cfg->id));
 
+  cfg->logcb = &logcb_stub;
   return cfg;
 }
 
@@ -58,6 +62,7 @@ append(cfg_t *cfg, const char *pattern) {
   size_t bufsize;
   char *buf = NULL;
   char *token = NULL;
+  int ret;
 
   assert(pattern != NULL);
 
@@ -79,11 +84,15 @@ append(cfg_t *cfg, const char *pattern) {
   if ((regex = calloc(1, sizeof(f2b_regex_t))) == NULL)
     return false;
 
-  if (regcomp(&regex->regex, buf, flags) == 0) {
+  if ((ret = regcomp(&regex->regex, buf, flags)) == 0) {
     regex->next = cfg->regexps;
     cfg->regexps = regex;
     strlcpy(regex->pattern, pattern, sizeof(regex->pattern));
     return true;
+  } else {
+    char buf[256] = "";
+    regerror(ret, &regex->regex, buf, sizeof(buf));
+    log_msg(cfg, error, "regex compile error: %s", buf);
   }
 
   free(regex);
@@ -115,13 +124,6 @@ stats(cfg_t *cfg, int *matches, char **pattern, bool reset) {
   return false;
 }
 
-const char *
-error(cfg_t *cfg) {
-  assert(cfg != NULL);
-
-  return cfg->error;
-}
-
 bool
 match(cfg_t *cfg, const char *line, char *buf, size_t buf_size) {
   f2b_regex_t *r = NULL;