MEDIUM: actions: Add standard return code for the action API

Action function can return 3 status:
 - error if the action encounter fatal error (like out of memory)
 - yield if the action must terminate his work later
 - continue in other cases
diff --git a/include/types/action.h b/include/types/action.h
index 09c14c5..713631e 100644
--- a/include/types/action.h
+++ b/include/types/action.h
@@ -32,6 +32,12 @@
 	ACT_F_HTTP_RES,    /* http-response */
 };
 
+enum act_return {
+	ACT_RET_CONT,  /* continue processing. */
+	ACT_RET_YIELD, /* call me again. */
+	ACT_RET_ERR,   /* processing error. */
+};
+
 enum act_name {
 	ACT_ACTION_CONT = 0,
 	ACT_ACTION_STOP,
@@ -78,8 +84,8 @@
 	enum act_name action;                  /* ACT_ACTION_* */
 	enum act_from from;                    /* ACT_F_* */
 	short deny_status;                     /* HTTP status to return to user when denying */
-	int (*action_ptr)(struct act_rule *rule, struct proxy *px,
-	                  struct session *sess, struct stream *s); /* ptr to custom action */
+	enum act_return (*action_ptr)(struct act_rule *rule, struct proxy *px,
+	                              struct session *sess, struct stream *s); /* ptr to custom action */
 	union {
 		struct {
 			char *realm;
diff --git a/src/hlua.c b/src/hlua.c
index 16ebc8d..5395b6d 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -4270,8 +4270,8 @@
  * return 0 if the function must be called again because the LUA
  * returns a yield.
  */
-static int hlua_request_act_wrapper(struct hlua_rule *rule, struct proxy *px,
-                                    struct stream *s, unsigned int analyzer)
+static enum act_return hlua_request_act_wrapper(struct hlua_rule *rule, struct proxy *px,
+                                                struct stream *s, unsigned int analyzer)
 {
 	char **arg;
 
@@ -4284,7 +4284,7 @@
 		send_log(px, LOG_ERR, "Lua action '%s': can't initialize Lua context.", rule->fcn.name);
 		if (!(global.mode & MODE_QUIET) || (global.mode & MODE_VERBOSE))
 			Alert("Lua action '%s': can't initialize Lua context.\n", rule->fcn.name);
-		return 1;
+		return ACT_RET_CONT;
 	}
 
 	/* If it is the first run, initialize the data for the call. */
@@ -4294,7 +4294,7 @@
 			send_log(px, LOG_ERR, "Lua function '%s': full stack.", rule->fcn.name);
 			if (!(global.mode & MODE_QUIET) || (global.mode & MODE_VERBOSE))
 				Alert("Lua function '%s': full stack.\n", rule->fcn.name);
-			return 1;
+			return ACT_RET_CONT;
 		}
 
 		/* Restore the function in the stack. */
@@ -4305,7 +4305,7 @@
 			send_log(px, LOG_ERR, "Lua function '%s': full stack.", rule->fcn.name);
 			if (!(global.mode & MODE_QUIET) || (global.mode & MODE_VERBOSE))
 				Alert("Lua function '%s': full stack.\n", rule->fcn.name);
-			return 1;
+			return ACT_RET_CONT;
 		}
 		s->hlua.nargs = 1;
 
@@ -4315,7 +4315,7 @@
 				send_log(px, LOG_ERR, "Lua function '%s': full stack.", rule->fcn.name);
 				if (!(global.mode & MODE_QUIET) || (global.mode & MODE_VERBOSE))
 					Alert("Lua function '%s': full stack.\n", rule->fcn.name);
-				return 1;
+				return ACT_RET_CONT;
 			}
 			lua_pushstring(s->hlua.T, *arg);
 			s->hlua.nargs++;
@@ -4332,7 +4332,7 @@
 	switch (hlua_ctx_resume(&s->hlua, 1)) {
 	/* finished. */
 	case HLUA_E_OK:
-		return 1;
+		return ACT_RET_CONT;
 
 	/* yield. */
 	case HLUA_E_AGAIN:
@@ -4354,7 +4354,7 @@
 		}
 		if (HLUA_IS_WAKEREQWR(&s->hlua))
 			s->req.flags |= CF_WAKE_WRITE;
-		return 0;
+		return ACT_RET_YIELD;
 
 	/* finished with error. */
 	case HLUA_E_ERRMSG:
@@ -4363,7 +4363,7 @@
 		if (!(global.mode & MODE_QUIET) || (global.mode & MODE_VERBOSE))
 			Alert("Lua function '%s': %s.\n", rule->fcn.name, lua_tostring(s->hlua.T, -1));
 		lua_pop(s->hlua.T, 1);
-		return 1;
+		return ACT_RET_CONT;
 
 	case HLUA_E_ERR:
 		/* Display log. */
@@ -4372,15 +4372,15 @@
 			Alert("Lua function '%s' return an unknown error.\n", rule->fcn.name);
 
 	default:
-		return 1;
+		return ACT_RET_CONT;
 	}
 }
 
 /* Lua execution wrapper for "tcp-request". This function uses
  * "hlua_request_act_wrapper" for executing the LUA code.
  */
-int hlua_tcp_req_act_wrapper(struct act_rule *act_rule, struct proxy *px,
-                             struct session *sess, struct stream *s)
+enum act_return hlua_tcp_req_act_wrapper(struct act_rule *act_rule, struct proxy *px,
+                                         struct session *sess, struct stream *s)
 {
 	return hlua_request_act_wrapper(act_rule->arg.hlua_rule, px, s, AN_REQ_INSPECT_FE);
 }
@@ -4388,8 +4388,8 @@
 /* Lua execution wrapper for "tcp-response". This function uses
  * "hlua_request_act_wrapper" for executing the LUA code.
  */
-int hlua_tcp_res_act_wrapper(struct act_rule *act_rule, struct proxy *px,
-                             struct session *sess, struct stream *s)
+enum act_return hlua_tcp_res_act_wrapper(struct act_rule *act_rule, struct proxy *px,
+                                         struct session *sess, struct stream *s)
 {
 	return hlua_request_act_wrapper(act_rule->arg.hlua_rule, px, s, AN_RES_INSPECT);
 }
@@ -4398,8 +4398,8 @@
  * This function uses "hlua_request_act_wrapper" for executing
  * the LUA code.
  */
-int hlua_http_req_act_wrapper(struct act_rule *rule, struct proxy *px,
-                              struct session *sess, struct stream *s)
+enum act_return hlua_http_req_act_wrapper(struct act_rule *rule, struct proxy *px,
+                                          struct session *sess, struct stream *s)
 {
 	return hlua_request_act_wrapper(rule->arg.hlua_rule, px, s, AN_REQ_HTTP_PROCESS_FE);
 }
@@ -4408,8 +4408,8 @@
  * This function uses "hlua_request_act_wrapper" for executing
  * the LUA code.
  */
-int hlua_http_res_act_wrapper(struct act_rule *rule, struct proxy *px,
-                              struct session *sess, struct stream *s)
+enum act_return hlua_http_res_act_wrapper(struct act_rule *rule, struct proxy *px,
+                                          struct session *sess, struct stream *s)
 {
 	return hlua_request_act_wrapper(rule->arg.hlua_rule, px, s, AN_RES_HTTP_PROCESS_BE);
 }
diff --git a/src/proto_http.c b/src/proto_http.c
index 6bd73b1..ce43ec5 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -3627,15 +3627,24 @@
 			}
 
 		case ACT_ACTION_CONT:
-			if (!rule->action_ptr(rule, px, s->sess, s)) {
+			switch (rule->action_ptr(rule, px, s->sess, s)) {
+			case ACT_RET_ERR:
+			case ACT_RET_CONT:
+				break;
+			case ACT_RET_YIELD:
 				s->current_rule = rule;
 				return HTTP_RULE_RES_YIELD;
 			}
 			break;
 
 		case ACT_ACTION_STOP:
-			rule->action_ptr(rule, px, s->sess, s);
-			return HTTP_RULE_RES_DONE;
+			switch (rule->action_ptr(rule, px, s->sess, s)) {
+			case ACT_RET_YIELD:
+			case ACT_RET_ERR:
+			case ACT_RET_CONT:
+				return HTTP_RULE_RES_DONE;
+			}
+			break;
 
 		case ACT_ACTION_TRK_SC0 ... ACT_ACTION_TRK_SCMAX:
 			/* Note: only the first valid tracking parameter of each
@@ -3907,7 +3916,11 @@
 			return HTTP_RULE_RES_DONE;
 
 		case ACT_ACTION_CONT:
-			if (!rule->action_ptr(rule, px, s->sess, s)) {
+			switch (rule->action_ptr(rule, px, s->sess, s)) {
+			case ACT_RET_ERR:
+			case ACT_RET_CONT:
+				break;
+			case ACT_RET_YIELD:
 				s->current_rule = rule;
 				return HTTP_RULE_RES_YIELD;
 			}
@@ -12246,8 +12259,8 @@
  * http_action_set_req_line_exec(). It always returns 1. If an error occurs
  * the action is canceled, but the rule processing continue.
  */
-int http_action_set_req_line(struct act_rule *rule, struct proxy *px,
-                             struct session *sess, struct stream *s)
+enum act_return http_action_set_req_line(struct act_rule *rule, struct proxy *px,
+                                         struct session *sess, struct stream *s)
 {
 	chunk_reset(&trash);
 
@@ -12257,7 +12270,7 @@
 	trash.len += build_logline(s, trash.str + trash.len, trash.size - trash.len, &rule->arg.http.logfmt);
 
 	http_replace_req_line(rule->arg.http.action, trash.str, trash.len, px, s);
-	return 1;
+	return ACT_RET_CONT;
 }
 
 /* parse an http-request action among :
@@ -12320,8 +12333,8 @@
  * returns 1. If an error occurs the action is cancelled, but the rule
  * processing continues.
  */
-int http_action_req_capture(struct act_rule *rule, struct proxy *px,
-                            struct session *sess, struct stream *s)
+enum act_return http_action_req_capture(struct act_rule *rule, struct proxy *px,
+                                        struct session *sess, struct stream *s)
 {
 	struct sample *key;
 	struct cap_hdr *h = rule->arg.cap.hdr;
@@ -12330,13 +12343,13 @@
 
 	key = sample_fetch_as_type(s->be, sess, s, SMP_OPT_DIR_REQ|SMP_OPT_FINAL, rule->arg.cap.expr, SMP_T_STR);
 	if (!key)
-		return 1;
+		return ACT_RET_CONT;
 
 	if (cap[h->index] == NULL)
 		cap[h->index] = pool_alloc2(h->pool);
 
 	if (cap[h->index] == NULL) /* no more capture memory */
-		return 1;
+		return ACT_RET_CONT;
 
 	len = key->data.u.str.len;
 	if (len > h->len)
@@ -12344,7 +12357,7 @@
 
 	memcpy(cap[h->index], key->data.u.str.str, len);
 	cap[h->index][len] = 0;
-	return 1;
+	return ACT_RET_CONT;
 }
 
 /* This function executes the "capture" action and store the result in a
@@ -12352,8 +12365,8 @@
  * into a string and puts it in a capture slot. It always returns 1. If an
  * error occurs the action is cancelled, but the rule processing continues.
  */
-int http_action_req_capture_by_id(struct act_rule *rule, struct proxy *px,
-                                  struct session *sess, struct stream *s)
+enum act_return http_action_req_capture_by_id(struct act_rule *rule, struct proxy *px,
+                                              struct session *sess, struct stream *s)
 {
 	struct sample *key;
 	struct cap_hdr *h;
@@ -12367,17 +12380,17 @@
 	     h != NULL && i != rule->arg.capid.idx ;
 	     i--, h = h->next);
 	if (!h)
-		return 1;
+		return ACT_RET_CONT;
 
 	key = sample_fetch_as_type(s->be, sess, s, SMP_OPT_DIR_REQ|SMP_OPT_FINAL, rule->arg.capid.expr, SMP_T_STR);
 	if (!key)
-		return 1;
+		return ACT_RET_CONT;
 
 	if (cap[h->index] == NULL)
 		cap[h->index] = pool_alloc2(h->pool);
 
 	if (cap[h->index] == NULL) /* no more capture memory */
-		return 1;
+		return ACT_RET_CONT;
 
 	len = key->data.u.str.len;
 	if (len > h->len)
@@ -12385,7 +12398,7 @@
 
 	memcpy(cap[h->index], key->data.u.str.str, len);
 	cap[h->index][len] = 0;
-	return 1;
+	return ACT_RET_CONT;
 }
 
 /* parse an "http-request capture" action. It takes a single argument which is
@@ -12519,8 +12532,8 @@
  * into a string and puts it in a capture slot. It always returns 1. If an
  * error occurs the action is cancelled, but the rule processing continues.
  */
-int http_action_res_capture_by_id(struct act_rule *rule, struct proxy *px,
-                                  struct session *sess, struct stream *s)
+enum act_return http_action_res_capture_by_id(struct act_rule *rule, struct proxy *px,
+                                              struct session *sess, struct stream *s)
 {
 	struct sample *key;
 	struct cap_hdr *h;
@@ -12534,17 +12547,17 @@
 	     h != NULL && i != rule->arg.capid.idx ;
 	     i--, h = h->next);
 	if (!h)
-		return 1;
+		return ACT_RET_CONT;
 
 	key = sample_fetch_as_type(s->be, sess, s, SMP_OPT_DIR_RES|SMP_OPT_FINAL, rule->arg.capid.expr, SMP_T_STR);
 	if (!key)
-		return 1;
+		return ACT_RET_CONT;
 
 	if (cap[h->index] == NULL)
 		cap[h->index] = pool_alloc2(h->pool);
 
 	if (cap[h->index] == NULL) /* no more capture memory */
-		return 1;
+		return ACT_RET_CONT;
 
 	len = key->data.u.str.len;
 	if (len > h->len)
@@ -12552,7 +12565,7 @@
 
 	memcpy(cap[h->index], key->data.u.str.str, len);
 	cap[h->index][len] = 0;
-	return 1;
+	return ACT_RET_CONT;
 }
 
 /* parse an "http-response capture" action. It takes a single argument which is
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index 3c70357..f797042 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -1231,9 +1231,15 @@
 			}
 			else {
 				/* Custom keywords. */
-				if (rule->action_ptr && !rule->action_ptr(rule, s->be, s->sess, s)) {
-					s->current_rule = rule;
-					goto missing_data;
+				if (rule->action_ptr) {
+					switch (rule->action_ptr(rule, s->be, s->sess, s)) {
+					case ACT_RET_ERR:
+					case ACT_RET_CONT:
+						break;
+					case ACT_RET_YIELD:
+						s->current_rule = rule;
+						goto missing_data;
+					}
 				}
 
 				/* accept */
@@ -1356,10 +1362,16 @@
 			}
 			else {
 				/* Custom keywords. */
-				if (rule->action_ptr && !rule->action_ptr(rule, s->be, s->sess, s)) {
-					channel_dont_close(rep);
-					s->current_rule = rule;
-					return 0;
+				if (rule->action_ptr) {
+					switch (rule->action_ptr(rule, s->be, s->sess, s)) {
+					case ACT_RET_ERR:
+					case ACT_RET_CONT:
+						break;
+					case ACT_RET_YIELD:
+						channel_dont_close(rep);
+						s->current_rule = rule;
+						return 0;
+					}
 				}
 
 				/* accept */
@@ -1441,7 +1453,19 @@
 			else {
 				/* Custom keywords. */
 				if (rule->action_ptr) {
-					rule->action_ptr(rule, sess->fe, sess, NULL);
+					switch (rule->action_ptr(rule, sess->fe, sess, NULL)) {
+					case ACT_RET_YIELD:
+						/* yield is not allowed at this point. If this return code is
+						 * used it is a bug, so I prefer to abort the process.
+						 */
+						send_log(sess->fe, LOG_WARNING,
+						         "Internal error: yield not allowed with tcp-request connection actions.");
+					case ACT_RET_CONT:
+						break;
+					case ACT_RET_ERR:
+						result = 0;
+						break;
+					}
 					if (rule->action == ACT_ACTION_CONT)
 						continue;
 				}
diff --git a/src/vars.c b/src/vars.c
index 86ac93b..4308012 100644
--- a/src/vars.c
+++ b/src/vars.c
@@ -482,49 +482,49 @@
 /* Returns 0 if we need to come back later to complete the sample's retrieval,
  * otherwise 1. For now all processing is considered final so we only return 1.
  */
-static inline int action_store(struct sample_expr *expr, const char *name,
-                               enum vars_scope scope, struct proxy *px,
-                               struct stream *s, int sens)
+static inline enum act_return action_store(struct sample_expr *expr, const char *name,
+                                           enum vars_scope scope, struct proxy *px,
+                                           struct stream *s, int sens)
 {
 	struct sample smp;
 
 	/* Process the expression. */
 	memset(&smp, 0, sizeof(smp));
 	if (!sample_process(px, s->sess, s, sens|SMP_OPT_FINAL, expr, &smp))
-		return 1;
+		return ACT_RET_CONT;
 
 	/* Store the sample, and ignore errors. */
 	sample_store_stream(name, scope, s, &smp);
-	return 1;
+	return ACT_RET_CONT;
 }
 
 /* Wrapper for action_store */
-static int action_tcp_req_store(struct act_rule *rule, struct proxy *px,
-                                struct session *sess, struct stream *s)
+static enum act_return action_tcp_req_store(struct act_rule *rule, struct proxy *px,
+                                            struct session *sess, struct stream *s)
 {
 	return action_store(rule->arg.vars.expr, rule->arg.vars.name,
 	                    rule->arg.vars.scope, px, s, SMP_OPT_DIR_REQ);
 }
 
 /* Wrapper for action_store */
-static int action_tcp_res_store(struct act_rule *rule, struct proxy *px,
-                                struct session *sess, struct stream *s)
+static enum act_return action_tcp_res_store(struct act_rule *rule, struct proxy *px,
+                                            struct session *sess, struct stream *s)
 {
 	return action_store(rule->arg.vars.expr, rule->arg.vars.name,
 	                    rule->arg.vars.scope, px, s, SMP_OPT_DIR_RES);
 }
 
 /* Wrapper for action_store */
-static int action_http_req_store(struct act_rule *rule, struct proxy *px,
-                                 struct session *sess, struct stream *s)
+static enum act_return action_http_req_store(struct act_rule *rule, struct proxy *px,
+                                             struct session *sess, struct stream *s)
 {
 	return action_store(rule->arg.vars.expr, rule->arg.vars.name,
 	                    rule->arg.vars.scope, px, s, SMP_OPT_DIR_REQ);
 }
 
 /* Wrapper for action_store */
-static int action_http_res_store(struct act_rule *rule, struct proxy *px,
-                                 struct session *sess, struct stream *s)
+static enum act_return action_http_res_store(struct act_rule *rule, struct proxy *px,
+                                             struct session *sess, struct stream *s)
 {
 	return action_store(rule->arg.vars.expr, rule->arg.vars.name,
 	                    rule->arg.vars.scope, px, s, SMP_OPT_DIR_RES);