commit fa45f1d06c46ce7d88a0205e08a3ed4df124aea1
author Thierry FOURNIER <tfournier@exceliance.fr> Tue Mar 18 13:54:18 2014 +0100
committer Willy Tarreau <w@1wt.eu> Mon Mar 31 09:56:40 2014 +0200
tree b1a064cfa1e23f39b4b0aa2e93da2167fa23187b
parent 9f95e4084c1ace3c01fa7a892278ac13df477a1c

MEDIUM: config: Dynamic sections.

This patch permit to register new sections in the haproxy's
configuration file. This run like all the "keyword" registration, it is
used during the haproxy initialization, typically with the
"__attribute__((constructor))" functions.

src/cfgparse.c

diff --git a/src/cfgparse.c b/src/cfgparse.c
index 5635c57..9f91f28 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -111,6 +111,18 @@
 	KWM_DEF,      /* "default" prefixed before the keyword */
 };
 
+/* permit to store configuration section */
+struct cfg_section {
+	struct list list;
+	char *section_name;
+	int (*section_parser)(const char *, int, char **, int);
+};
+
+/* Used to chain configuration sections definitions. This list
+ * stores struct cfg_section
+ */
+struct list sections = LIST_HEAD_INIT(sections);
+
 /* some of the most common options which are also the easiest to handle */
 struct cfg_opt {
 	const char *name;
@@ -6401,8 +6413,20 @@
 	char thisline[LINESIZE];
 	FILE *f;
 	int linenum = 0;
-	int confsect = CFG_NONE;
 	int err_code = 0;
+	struct cfg_section *cs = NULL;
+	struct cfg_section *ics;
+
+	/* Register internal sections */
+	if (!cfg_register_section("listen",   cfg_parse_listen) ||
+	    !cfg_register_section("frontend", cfg_parse_listen) ||
+	    !cfg_register_section("backend",  cfg_parse_listen) ||
+	    !cfg_register_section("ruleset",  cfg_parse_listen) ||
+	    !cfg_register_section("defaults", cfg_parse_listen) ||
+	    !cfg_register_section("global",   cfg_parse_global) ||
+	    !cfg_register_section("userlist", cfg_parse_users)  ||
+	    !cfg_register_section("peers",    cfg_parse_peers))
+		return -1;
 
 	if ((f=fopen(file,"r")) == NULL)
 		return -1;
@@ -6542,47 +6566,19 @@
 			err_code |= ERR_ALERT | ERR_FATAL;
 		}
 
-		if (!strcmp(args[0], "listen") ||
-		    !strcmp(args[0], "frontend") ||
-		    !strcmp(args[0], "backend") ||
-		    !strcmp(args[0], "ruleset") ||
-		    !strcmp(args[0], "defaults")) { /* new proxy */
-			confsect = CFG_LISTEN;
-			free(cursection);
-			cursection = strdup(args[0]);
-		}
-		else if (!strcmp(args[0], "global")) { /* global config */
-			confsect = CFG_GLOBAL;
-			free(cursection);
-			cursection = strdup(args[0]);
-		}
-		else if (!strcmp(args[0], "userlist")) {
-			confsect = CFG_USERLIST;
-			free(cursection);
-			cursection = strdup(args[0]);
-		}
-		else if (!strcmp(args[0], "peers")) {
-			confsect = CFG_PEERS;
-			free(cursection);
-			cursection = strdup(args[0]);
+		/* detect section start */
+		list_for_each_entry(ics, &sections, list) {
+			if (strcmp(args[0], ics->section_name) == 0) {
+				cursection = ics->section_name;
+				cs = ics;
+				break;
+			}
 		}
 
 		/* else it's a section keyword */
-
-		switch (confsect) {
-		case CFG_LISTEN:
-			err_code |= cfg_parse_listen(file, linenum, args, kwm);
-			break;
-		case CFG_GLOBAL:
-			err_code |= cfg_parse_global(file, linenum, args, kwm);
-			break;
-		case CFG_USERLIST:
-			err_code |= cfg_parse_users(file, linenum, args, kwm);
-			break;
-		case CFG_PEERS:
-			err_code |= cfg_parse_peers(file, linenum, args, kwm);
-			break;
-		default:
+		if (cs)
+			err_code |= cs->section_parser(file, linenum, args, kwm);
+		else {
 			Alert("parsing [%s:%d]: unknown keyword '%s' out of section.\n", file, linenum, args[0]);
 			err_code |= ERR_ALERT | ERR_FATAL;
 		}
@@ -6590,7 +6586,6 @@
 		if (err_code & ERR_ABORT)
 			break;
 	}
-	free(cursection);
 	cursection = NULL;
 	fclose(f);
 	return err_code;
@@ -7856,6 +7851,30 @@
 	LIST_INIT(&kwl->list);
 }
 
+/* this function register new section in the haproxy configuration file.
+ * <section_name> is the name of this new section and <section_parser>
+ * is the called parser. If two section declaration have the same name,
+ * only the first declared is used.
+ */
+int cfg_register_section(char *section_name,
+                         int (*section_parser)(const char *, int, char **, int))
+{
+	struct cfg_section *cs;
+
+	cs = calloc(1, sizeof(*cs));
+	if (!cs) {
+		Alert("register section '%s': out of memory.\n", section_name);
+		return 0;
+	}
+
+	cs->section_name = section_name;
+	cs->section_parser = section_parser;
+
+	LIST_ADDQ(&sections, &cs->list);
+
+	return 1;
+}
+
 /*
  * Local variables:
  *  c-indent-level: 8