MINOR: proxy: add proxy_free_common() helper function

As shown by previous patch series, having to free some common proxy
struct members twice (in free_proxy() and proxy_free_defaults()) is
error-prone: we often overlook one of the two free locations when
adding new features.

To prevent such bugs from being introduced in the future, and also avoid
code duplication, we now have a proxy_free_common() function to free all
proxy struct members that are common to all proxy types (either regular or
default ones).

This should greatly improve code maintenance related to proxy freeing
logic.

(cherry picked from commit 005e4ba)
[cf: Required in 3.0 to ease backport of a bug fix]
Signed-off-by: Christopher Faulet <[email protected]>

Author: Darlelet

src/proxy.c

@@ -191,46 +191,87 @@ void free_server_rules(struct list *srules)
 	}
 }
 
+/* Frees proxy members that are common to all proxy types (either regular or
+ * default ones) for a proxy that's about to be destroyed.
+ * This is a subset of the complete proxy or default proxy deinit code.
+ */
+static inline void proxy_free_common(struct proxy *px)
+{
+	struct acl *acl, *aclb;
+	struct logger *log, *logb;
+
+	ha_free(&px->id);
+	ha_free(&px->conf.file);
+	ha_free(&px->check_command);
+	ha_free(&px->check_path);
+	ha_free(&px->cookie_name);
+	ha_free(&px->rdp_cookie_name);
+	ha_free(&px->dyncookie_key);
+	ha_free(&px->cookie_domain);
+	ha_free(&px->cookie_attrs);
+	ha_free(&px->lbprm.arg_str);
+	ha_free(&px->capture_name);
+	istfree(&px->monitor_uri);
+	ha_free(&px->conn_src.iface_name);
+#if defined(CONFIG_HAP_TRANSPARENT)
+	ha_free(&px->conn_src.bind_hdr_name);
+#endif
+	istfree(&px->server_id_hdr_name);
+	istfree(&px->header_unique_id);
+
+	http_ext_clean(px);
+
+	list_for_each_entry_safe(acl, aclb, &px->acl, list) {
+		LIST_DELETE(&acl->list);
+		prune_acl(acl);
+		free(acl);
+	}
+
+	free_act_rules(&px->tcp_req.inspect_rules);
+	free_act_rules(&px->tcp_rep.inspect_rules);
+	free_act_rules(&px->tcp_req.l4_rules);
+	free_act_rules(&px->tcp_req.l5_rules);
+	free_act_rules(&px->http_req_rules);
+	free_act_rules(&px->http_res_rules);
+	free_act_rules(&px->http_after_res_rules);
+
+	lf_expr_deinit(&px->logformat);
+	lf_expr_deinit(&px->logformat_sd);
+	lf_expr_deinit(&px->logformat_error);
+	lf_expr_deinit(&px->format_unique_id);
+
+	list_for_each_entry_safe(log, logb, &px->loggers, list) {
+		LIST_DEL_INIT(&log->list);
+		free_logger(log);
+	}
+
+	chunk_destroy(&px->log_tag);
+
+	free_email_alert(px);
+}
+
 void free_proxy(struct proxy *p)
 {
 	struct server *s;
 	struct cap_hdr *h,*h_next;
 	struct listener *l,*l_next;
 	struct bind_conf *bind_conf, *bind_back;
 	struct acl_cond *cond, *condb;
-	struct acl *acl, *aclb;
 	struct switching_rule *rule, *ruleb;
 	struct redirect_rule *rdr, *rdrb;
-	struct logger *log, *logb;
 	struct proxy_deinit_fct *pxdf;
 	struct server_deinit_fct *srvdf;
 
 	if (!p)
 		return;
 
-	free(p->conf.file);
-	free(p->id);
-	free(p->cookie_name);
-	free(p->cookie_domain);
-	free(p->cookie_attrs);
-	free(p->lbprm.arg_str);
+	proxy_free_common(p);
+
+	/* regular proxy specific cleanup */
 	release_sample_expr(p->lbprm.expr);
 	free(p->server_state_file_name);
-	free(p->capture_name);
-	istfree(&p->monitor_uri);
-	istfree(&p->server_id_hdr_name);
-	ha_free(&p->check_command);
-	ha_free(&p->check_path);
-	ha_free(&p->dyncookie_key);
-	free(p->rdp_cookie_name);
-	free_email_alert(p);
 	free(p->invalid_rep);
 	free(p->invalid_req);
-	ha_free(&p->conn_src.iface_name);
-#if defined(CONFIG_HAP_TRANSPARENT)
-	free(p->conn_src.bind_hdr_name);
-#endif
-	istfree(&p->header_unique_id);
 	if ((p->lbprm.algo & BE_LB_LKUP) == BE_LB_LKUP_MAP)
 		free(p->lbprm.map.srv);
 
@@ -244,12 +285,6 @@ void free_proxy(struct proxy *p)
 	EXTRA_COUNTERS_FREE(p->extra_counters_fe);
 	EXTRA_COUNTERS_FREE(p->extra_counters_be);
 
-	list_for_each_entry_safe(acl, aclb, &p->acl, list) {
-		LIST_DELETE(&acl->list);
-		prune_acl(acl);
-		free(acl);
-	}
-
 	free_server_rules(&p->server_rules);
 
 	list_for_each_entry_safe(rule, ruleb, &p->switching_rules, list) {
@@ -266,26 +301,6 @@ void free_proxy(struct proxy *p)
 		http_free_redirect_rule(rdr);
 	}
 
-	list_for_each_entry_safe(log, logb, &p->loggers, list) {
-		LIST_DEL_INIT(&log->list);
-		free_logger(log);
-	}
-
-	chunk_destroy(&p->log_tag);
-
-	lf_expr_deinit(&p->logformat);
-	lf_expr_deinit(&p->logformat_sd);
-	lf_expr_deinit(&p->format_unique_id);
-	lf_expr_deinit(&p->logformat_error);
-
-	free_act_rules(&p->tcp_req.inspect_rules);
-	free_act_rules(&p->tcp_rep.inspect_rules);
-	free_act_rules(&p->tcp_req.l4_rules);
-	free_act_rules(&p->tcp_req.l5_rules);
-	free_act_rules(&p->http_req_rules);
-	free_act_rules(&p->http_res_rules);
-	free_act_rules(&p->http_after_res_rules);
-
 	free_stick_rules(&p->storersp_rules);
 	free_stick_rules(&p->sticking_rules);
 
@@ -356,8 +371,6 @@ void free_proxy(struct proxy *p)
 
 	free(p->desc);
 
-	http_ext_clean(p);
-
 	task_destroy(p->task);
 
 	pool_destroy(p->req_cap_pool);
@@ -1429,53 +1442,19 @@ void proxy_preset_defaults(struct proxy *defproxy)
 }
 
 /* Frees all dynamic settings allocated on a default proxy that's about to be
- * destroyed. This is a subset of the complete proxy deinit code, but these
- * should probably be merged ultimately. Note that most of the fields are not
- * even reset, so extreme care is required here, and calling
- * proxy_preset_defaults() afterwards would be safer.
+ * destroyed. Note that most of the fields are not even reset, so extreme care
+ * is required here, and calling proxy_preset_defaults() afterwards would be
+ * safer.
  */
 void proxy_free_defaults(struct proxy *defproxy)
 {
-	struct acl *acl, *aclb;
-	struct logger *log, *logb;
 	struct cap_hdr *h,*h_next;
 
-	ha_free(&defproxy->id);
-	ha_free(&defproxy->conf.file);
+	proxy_free_common(defproxy);
+
+	/* default proxy specific cleanup */
 	ha_free((char **)&defproxy->defsrv.conf.file);
-	ha_free(&defproxy->check_command);
-	ha_free(&defproxy->check_path);
-	ha_free(&defproxy->cookie_name);
-	ha_free(&defproxy->rdp_cookie_name);
-	ha_free(&defproxy->dyncookie_key);
-	ha_free(&defproxy->cookie_domain);
-	ha_free(&defproxy->cookie_attrs);
-	ha_free(&defproxy->lbprm.arg_str);
-	ha_free(&defproxy->capture_name);
-	istfree(&defproxy->monitor_uri);
 	ha_free(&defproxy->defbe.name);
-	ha_free(&defproxy->conn_src.iface_name);
-#if defined(CONFIG_HAP_TRANSPARENT)
-	ha_free(&defproxy->conn_src.bind_hdr_name);
-#endif
-	istfree(&defproxy->header_unique_id);
-	istfree(&defproxy->server_id_hdr_name);
-
-	http_ext_clean(defproxy);
-
-	list_for_each_entry_safe(acl, aclb, &defproxy->acl, list) {
-		LIST_DELETE(&acl->list);
-		prune_acl(acl);
-		free(acl);
-	}
-
-	free_act_rules(&defproxy->tcp_req.inspect_rules);
-	free_act_rules(&defproxy->tcp_rep.inspect_rules);
-	free_act_rules(&defproxy->tcp_req.l4_rules);
-	free_act_rules(&defproxy->tcp_req.l5_rules);
-	free_act_rules(&defproxy->http_req_rules);
-	free_act_rules(&defproxy->http_res_rules);
-	free_act_rules(&defproxy->http_after_res_rules);
 
 	h = defproxy->req_cap;
 	while (h) {
@@ -1495,19 +1474,6 @@ void proxy_free_defaults(struct proxy *defproxy)
 		h = h_next;
 	}
 
-	lf_expr_deinit(&defproxy->logformat);
-	lf_expr_deinit(&defproxy->logformat_sd);
-	lf_expr_deinit(&defproxy->logformat_error);
-	lf_expr_deinit(&defproxy->format_unique_id);
-
-	list_for_each_entry_safe(log, logb, &defproxy->loggers, list) {
-		LIST_DEL_INIT(&log->list);
-		free_logger(log);
-	}
-
-	chunk_destroy(&defproxy->log_tag);
-
-	free_email_alert(defproxy);
 	proxy_release_conf_errors(defproxy);
 	deinit_proxy_tcpcheck(defproxy);