make libconfig optionnal again

Makefile

@@ -1,6 +1,8 @@
-# Configuration
 
 VERSION=$(shell ./genver.sh -r)
+
+# Configuration -- you probably need to `make clean` if you
+# change any of these
 ENABLE_REGEX=1  # Enable regex probes
 USELIBCONFIG=1	# Use libconfig? (necessary to use configuration files)
 USELIBPCRE=1	# Use libpcre? (needed for regex on musl)

doc/INSTALL.md

@@ -42,7 +42,7 @@ For Fedora, you'll need packages `libconfig` and
 If you want to rebuild `sslh-conf.c` (after a `make
 distclean` for example), you will also need to add
 [conf2struct](https://www.rutschle.net/tech/conf2struct/README.html)
-(v1.3) to your path.
+(v1.4) to your path.
 
 Compilation
 -----------

sslh-conf.c

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Sun Jul 19 16:59:51 2020. 
+ * on Fri Jul 24 16:29:39 2020. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2019  Yves Rutschle
@@ -30,9 +30,12 @@
 
 #define _GNU_SOURCE
 #include <string.h>
-#include <libconfig.h>
+#ifdef LIBCONFIG
+#    include <libconfig.h>
+#endif
 #include <stdlib.h>
 #include <stddef.h>
+#include <stdio.h>
 #include "sslh-conf.h"
 #include "argtable3.h"
 #ifdef LIBPCRE
@@ -56,18 +59,7 @@ typedef enum {
     CFG_ARRAY,
     CFG_LIST,
 } config_type;
-
-typedef int (*lookup_fn)(const config_setting_t*, const char*, void*);
-lookup_fn lookup_fns[] = {
-    (lookup_fn)config_setting_lookup_bool,
-    (lookup_fn)config_setting_lookup_int,
-    (lookup_fn)config_setting_lookup_int64,
-    (lookup_fn)config_setting_lookup_float,
-    (lookup_fn)config_setting_lookup_string,
-    NULL,  /* CFG_GROUP */
-    NULL,  /* CFG_ARRAY */
-    NULL,  /* CFG_LIST */
-};
+/* /config_type */
 
 const char* type2str[] = {
     "boolean",
@@ -80,8 +72,6 @@ const char* type2str[] = {
     "list",
 };
 
-/* /config_type */
-
 typedef union {
     int def_bool;
     int def_int;
@@ -90,6 +80,97 @@ typedef union {
     char* def_string;
 } any_val;
 
+struct config_desc {
+    const char* name;
+    int type;
+    struct config_desc * sub_group; /* Table for compound types (list and group) */
+    void* arg_cl; /* command-line argument for this setting */
+    void* base_addr; /* Base of the structure (filled at runtime). Probably not useable for list elements */
+    size_t offset;  /* Offset of setting in the structure */
+    size_t offset_len; /* Offset of *_len field, for arrays and lists */
+    size_t offset_present; /* offset of *_is_present field, for optional settings */
+    size_t size;   /* Size of element, or size of group for groups and lists */
+    int array_type; /* type of array elements, when type == CFG_ARRAY */
+    int mandatory;
+    int optional;
+    any_val default_val;
+};
+
+#ifndef LIBCONFIG
+/* Stubs in case you don't want libconfig */
+
+typedef void config_setting_t;
+typedef int config_t;
+#define CONFIG_TRUE 1
+#define CONFIG_FALSE 0
+
+#define make_config_setting_lookup(type) \
+    int config_setting_lookup_##type(const config_setting_t* a, const char* b, void* c) { \
+        return 0; \
+    }
+
+#define make_config_setting_get(type, ret_type) \
+    ret_type config_setting_get_##type(const config_setting_t* a) { \
+        return 0; \
+    }
+
+make_config_setting_lookup(bool);
+make_config_setting_lookup(int);
+make_config_setting_lookup(int64);
+make_config_setting_lookup(float);
+make_config_setting_lookup(string);
+
+make_config_setting_get(bool, int);
+make_config_setting_get(int, int);
+make_config_setting_get(int64, int);
+make_config_setting_get(float, double);
+make_config_setting_get(string, char*);
+
+config_setting_t* config_lookup(config_t* c, const char* b) {
+    return NULL;
+}
+
+void config_init(config_t* c) {
+    return;
+}
+
+config_setting_t* config_setting_lookup(config_setting_t* a, char* b) {
+    return NULL;
+}
+
+int config_setting_length(config_setting_t* a) {
+    return 0;
+}
+
+config_setting_t* config_setting_get_elem(config_setting_t* a, int i) {
+    return NULL;
+}
+
+int config_read_file(config_t* a, const char* b) {
+    return CONFIG_TRUE;
+}
+
+int config_error_line(config_t* c) {
+    return 0;
+}
+
+char* config_error_text(config_t* c) {
+    return NULL;
+}
+#endif
+
+typedef int (*lookup_fn)(const config_setting_t*, const char*, void*);
+lookup_fn lookup_fns[] = {
+    (lookup_fn)config_setting_lookup_bool,
+    (lookup_fn)config_setting_lookup_int,
+    (lookup_fn)config_setting_lookup_int64,
+    (lookup_fn)config_setting_lookup_float,
+    (lookup_fn)config_setting_lookup_string,
+    NULL,  /* CFG_GROUP */
+    NULL,  /* CFG_ARRAY */
+    NULL,  /* CFG_LIST */
+};
+
 /* Copy an any_val to arbitrary memory location */
 /* 0: success
  * <0: error */
@@ -253,22 +334,6 @@ static int stringcpy(config_type type, void* target, char* from)
 }
 
 
-struct config_desc {
-    const char* name;
-    int type;
-    struct config_desc * sub_group; /* Table for compound types (list and group) */
-    void* arg_cl; /* command-line argument for this setting */
-    void* base_addr; /* Base of the structure (filled at runtime). Probably not useable for list elements */
-    size_t offset;  /* Offset of setting in the structure */
-    size_t offset_len; /* Offset of *_len field, for arrays and lists */
-    size_t offset_present; /* offset of *_is_present field, for optional settings */
-    size_t size;   /* Size of element, or size of group for groups and lists */
-    int array_type; /* type of array elements, when type == CFG_ARRAY */
-    int mandatory;
-    int optional;
-    any_val default_val;
-};
-
 /* Element to describe the target of a compound element
 * element: which config entry is being changed
 * match: if >0, index in pmatch to set
@@ -1488,7 +1553,9 @@ int sslhcfg_cl_parse(int argc, char* argv[], struct sslhcfg_item* cfg)
     char* errmsg;
     config_setting_t* s;
     void* argtable[] = {
-                sslhcfg_conffile = arg_filen("F", "config", "<file>", 0, 1, "Specify configuration file"),
+            #ifdef LIBCONFIG
+        sslhcfg_conffile = arg_filen("F", "config", "<file>", 0, 1, "Specify configuration file"),
+    #endif
          sslhcfg_verbose = arg_intn("v", "verbose", "<n>", 0, 1, ""),
          sslhcfg_foreground = arg_litn("f", "foreground", 0, 1, "Run in foreground instead of as a daemon"),
          sslhcfg_inetd = arg_litn("i", "inetd", 0, 1, "Run in inetd mode: use stdin/stdout instead of network listen"),

sslh-conf.h

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Sun Jul 19 16:59:51 2020. 
+ * on Fri Jul 24 16:29:39 2020. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2019  Yves Rutschle
@@ -30,7 +30,9 @@
 
 #ifndef C2S_SSLHCFG_H
 #define C2S_SSLHCFG_H
-#include <libconfig.h>
+#ifdef LIBCONFIG
+#    include <libconfig.h>
+#endif
 
 
 #include "probe.h"

sslh-main.c

@@ -144,7 +144,6 @@ void cmd_ssl_to_tls(int argc, char* argv[])
 /* Extract configuration on addresses and ports on which to listen.
  * out: newly allocated list of addrinfo to listen to
  */
-#ifdef LIBCONFIG
 static int config_resolve_listen(struct addrinfo **listen)
 {
     int i, res;
@@ -164,12 +163,11 @@ static int config_resolve_listen(struct addrinfo **listen)
     }
     return 0;
 }
-#endif
 
 
 
-#ifdef LIBCONFIG
 static void setup_regex_probe(struct sslhcfg_protocols_item *p)
+#ifdef LIBCONFIG
 {
     int num_patterns, i, res;
     regex_t** pattern_list;
@@ -196,6 +194,10 @@ static void setup_regex_probe(struct sslhcfg_protocols_item *p)
         }
     }
 }
+#else
+{
+    return;
+}
 #endif
 
 /* For each protocol in the configuration, resolve address and set up protocol