warn about unknown settings in the configuration file

ChangeLog

@@ -2,6 +2,9 @@ vNEXT:
 	Added symbol to support libconfig 1.4.9, still in
 	use in CentOS7.
 
+	Warn about unknown settings in the configuration
+	file.
+
 v1.21: 11JUL2020
 	WARNING:
 	Moved configuration and command-line management to

sslh-conf.c

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Tue Aug 11 17:35:54 2020. 
+ * on Sat Aug 29 18:12:55 2020. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2019  Yves Rutschle
@@ -171,13 +171,30 @@ char* config_error_text(config_t* c) {
 }
 #endif
 
+/* This is the same as config_setting_lookup_string() except
+it allocates a new string which belongs to the caller */
+static int myconfig_setting_lookup_stringcpy(
+        const config_setting_t* setting, 
+        const char* name, 
+        char** value)
+{
+    const char* str;
+    *value = NULL;
+    if (config_setting_lookup_string(setting, name, &str) == CONFIG_TRUE) {
+        asprintf(value, "%s", str);
+        return CONFIG_TRUE;
+    } else {
+        return CONFIG_FALSE;
+    }
+}
+
 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,
+    (lookup_fn)myconfig_setting_lookup_stringcpy,
     NULL,  /* CFG_GROUP */
     NULL,  /* CFG_ARRAY */
     NULL,  /* CFG_LIST */
@@ -1120,7 +1137,7 @@ static void print_setting(config_type type, void* val)
 
 /* Changes all dashes to underscores in a string of
 * vice-versa */
-void strswap_ud(const char target, char* str)
+static void strswap_ud(const char target, char* str)
 {
     char* c;
     for (c = str; *c; c++)
@@ -1130,7 +1147,7 @@ void strswap_ud(const char target, char* str)
 
 /* Same as config_setting_lookup() but looks up with dash or
 * underscore so `my_setting` and `my-setting` match the same */
-config_setting_t* config_setting_lookup_ud(config_setting_t* cfg, struct config_desc* desc)
+static config_setting_t* config_setting_lookup_ud(config_setting_t* cfg, struct config_desc* desc)
 {
     config_setting_t* setting;
     char name[strlen(desc->name)+1];;
@@ -1146,7 +1163,7 @@ config_setting_t* config_setting_lookup_ud(config_setting_t* cfg, struct config_
     return setting;
 }
 
-int lookup_typed_ud(config_setting_t* cfg, void* target, struct config_desc *desc)
+static int lookup_typed_ud(config_setting_t* cfg, void* target, struct config_desc *desc)
 {
     lookup_fn lookup_fn = lookup_fns[desc->type];
     char name[strlen(desc->name)+1];;
@@ -1160,6 +1177,22 @@ int lookup_typed_ud(config_setting_t* cfg, void* target, struct config_desc *des
     return lookup_fn(cfg, name, ((char*)target) + desc->offset);
 }
 
+/* Removes a setting, trying both underscores and dashes as
+* name (so deleting 'my-setting' deletes both 'my_setting'
+* and 'my-setting') */
+static int setting_delete_ud(config_setting_t* cfg, struct config_desc *desc)
+{
+    char name[strlen(desc->name)+1];;
+    strcpy(name, desc->name);
+
+    strswap_ud('_', name);
+    if (config_setting_remove(cfg, name) == CONFIG_TRUE)
+        return CONFIG_TRUE;
+
+    strswap_ud('-', name);
+    return config_setting_remove(cfg, name);
+}
+
 /* When traversing configuration, allocate memory for plural
 * types, init for scalars */
 static void read_block_init(void* target, config_setting_t* cfg, struct config_desc* desc)
@@ -1244,6 +1277,7 @@ static int read_block_setval(void* target,
                 TRACE_READ(("[%d] = ", i));
                 print_setting(desc->array_type, (char*)block + desc->size *i); TRACE_READ(("\n"));
             }
+            setting_delete_ud(cfg, desc);
         }
         break;
 
@@ -1265,6 +1299,7 @@ static int read_block_setval(void* target,
                 return 0;
             }
             print_setting(desc->type, (((char*)target) + desc->offset));
+            setting_delete_ud(cfg, desc);
             in_cfg = 1;
         } else {
             TRACE_READ((" not in config file"));
@@ -1556,6 +1591,86 @@ static int c2s_parse_file(const char* filename, config_t* c, char**errmsg)
     return 1;
 }
 
+/* Allocates a new string that represents the setting value, which must be a scalar */
+static void scalar_to_string(char** strp, config_setting_t* s)
+{
+    switch(config_setting_type(s)) {
+    case CONFIG_TYPE_INT:
+        asprintf(strp, "%d\n", config_setting_get_int(s));
+        break;
+
+    case CONFIG_TYPE_BOOL:
+        asprintf(strp, "%s\n", config_setting_get_bool(s) ?  "[true]" : "[false]" );
+        break;
+
+    case CONFIG_TYPE_INT64:
+        asprintf(strp, "%lld\n", config_setting_get_int64(s));
+        break;
+
+    case CONFIG_TYPE_FLOAT:
+        asprintf(strp, "%lf\n", config_setting_get_float(s));
+        break;
+
+    case CONFIG_TYPE_STRING:
+        asprintf(strp, "%s\n", config_setting_get_string(s));
+        break;
+
+    default: /* This means a bug */
+        fprintf(stderr, "Unexpected type %d\n", config_setting_type(s));
+        exit(1);
+    }
+}
+
+/* Typesets all the settings in a configuration as a
+* newly-allocated string. The string management is caller's
+* responsability. 
+* Returns the number of scalars in the configuration */
+static int cfg_as_string(config_setting_t* parent, const char* path, char** strp)
+{
+    int i, len, res = 0;
+    config_setting_t* child;
+    char* subpath, *value, *old;
+    const char* name;
+
+    len = config_setting_length(parent);
+    for (i = 0; i < len; i++) {
+        child = config_setting_get_elem(parent, i);
+        name = config_setting_name(child);
+        if (!name) name = "";
+
+        if(config_setting_is_list(parent) ||
+           config_setting_is_array(parent)) {
+            asprintf(&subpath, "%s[%d]%s", path, config_setting_index(child), name);
+        } else {
+            asprintf(&subpath, "%s/%s", path, name);
+        }
+
+        if (config_setting_is_scalar(child)) {
+            scalar_to_string(&value, child);
+
+            /* Add value to the output string  */
+            if (*strp) {
+                asprintf(&old, "%s", *strp);
+                free(*strp);
+            }  else {
+                asprintf(&old, "%s", "");
+            }
+            asprintf(strp, "%s%s:%s", old, subpath, value);
+            free(value);
+            free(old);
+
+            res++; /* At least one scalar was found */
+        } else {
+            /* It's an aggregate -- descend into it */
+            res += cfg_as_string(child, subpath, strp);
+        }
+
+        free(subpath);
+    }
+    return res;
+}
+
+
 /* 0: success
    <0: error */
 int sslhcfg_cl_parse(int argc, char* argv[], struct sslhcfg_item* cfg)
@@ -1625,6 +1740,11 @@ int sslhcfg_cl_parse(int argc, char* argv[], struct sslhcfg_item* cfg)
         return -1;
     }
 
+    errmsg = NULL;
+    res = cfg_as_string(s, "", &errmsg);
+    if (res)
+        fprintf(stderr, "Unknown settings:\n%s\n", errmsg);
+
     return 0;
 }
 

sslh-conf.h

@@ -1,5 +1,5 @@
 /* Generated by conf2struct (https://www.rutschle.net/tech/conf2struct/README)
- * on Tue Aug 11 17:35:54 2020. 
+ * on Sat Aug 29 18:12:55 2020. 
 
 # conf2struct: generate libconf parsers that read to structs
 # Copyright (C) 2018-2019  Yves Rutschle

test.cfg

@@ -33,7 +33,7 @@ protocols:
      { name: "regex"; host: "localhost"; port: "9011";
         regex_patterns: [ "^foo", "^bar" ];
         minlength: 4; 
-        test_patterns: (
+        test_patterns: (    # this is used by the test script, not by sslh
             { pattern: "foo"; result: "ssh"; },  # After timeout
             { pattern: "fooo"; result: "regex"; },
             { pattern: "bar"; result: "ssh"; },