MINOR: proxy: simplify parsing 'backend/server'

Several CLI handlers use a server argument specified with the format
'<backend>/<server>'. The parsing of this arguement is done in two
steps, first splitting the string with '/' delimiter and then use
get_backend_server() to retrieve the server instance.

Refactor this code sections with the following changes :
* splitting is reimplented using ist API
* get_backend_server() is removed. Instead use the already existing
  proxy_be_by_name() then server_find_by_name() which contains
  duplicated code with the now removed function.

No functional change occurs with this commit. However, it will be useful
to add new configuration options reusing the same '<backend>/<server>'
for reverse connect.

include/haproxy/proxy.h

@@ -74,8 +74,6 @@ struct proxy *alloc_new_proxy(const char *name, unsigned int cap,
 struct proxy *parse_new_proxy(const char *name, unsigned int cap,
                               const char *file, int linenum,
                               const struct proxy *defproxy);
-int get_backend_server(const char *bk_name, const char *sv_name,
-		       struct proxy **bk, struct server **sv);
 void proxy_capture_error(struct proxy *proxy, int is_back,
 			 struct proxy *other_end, enum obj_type *target,
 			 const struct session *sess,

src/proxy.c

@@ -450,42 +450,6 @@ const char *proxy_find_best_option(const char *word, const char **extra)
 	return best_ptr;
 }
 
-/*
- * This function scans the list of backends and servers to retrieve the first
- * backend and the first server with the given names, and sets them in both
- * parameters. It returns zero if either is not found, or non-zero and sets
- * the ones it did not found to NULL. If a NULL pointer is passed for the
- * backend, only the pointer to the server will be updated.
- */
-int get_backend_server(const char *bk_name, const char *sv_name,
-		       struct proxy **bk, struct server **sv)
-{
-	struct proxy *p;
-	struct server *s;
-	int sid;
-
-	*sv = NULL;
-
-	sid = -1;
-	if (*sv_name == '#')
-		sid = atoi(sv_name + 1);
-
-	p = proxy_be_by_name(bk_name);
-	if (bk)
-		*bk = p;
-	if (!p)
-		return 0;
-
-	for (s = p->srv; s; s = s->next)
-		if ((sid >= 0 && s->puid == sid) ||
-		    (sid < 0 && strcmp(s->id, sv_name) == 0))
-			break;
-	*sv = s;
-	if (!s)
-		return 0;
-	return 1;
-}
-
 /* This function parses a "timeout" statement in a proxy section. It returns
  * -1 if there is any error, 1 for a warning, otherwise zero. If it does not
  * return zero, it will write an error or warning message into a preallocated

src/server.c

@@ -4204,22 +4204,20 @@ struct server *cli_find_server(struct appctx *appctx, char *arg)
 {
 	struct proxy *px;
 	struct server *sv;
-	char *line;
+	struct ist be_name, sv_name = ist(arg);
 
-	/* split "backend/server" and make <line> point to server */
-	for (line = arg; *line; line++)
-		if (*line == '/') {
-			*line++ = '\0';
-			break;
-		}
-
-	if (!*line || !*arg) {
-		cli_err(appctx, "Require 'backend/server'.\n");
+	be_name = istsplit(&sv_name, '/');
+	if (!istlen(sv_name)) {
+		cli_err(appctx, "Require 'backend/server'.");
 		return NULL;
 	}
 
-	if (!get_backend_server(arg, line, &px, &sv)) {
-		cli_err(appctx, px ? "No such server.\n" : "No such backend.\n");
+	if (!(px = proxy_be_by_name(ist0(be_name)))) {
+		cli_err(appctx, "No such backend.");
+		return NULL;
+	}
+	if (!(sv = server_find_by_name(px, ist0(sv_name)))) {
+		cli_err(appctx, "No such server.");
 		return NULL;
 	}
 
@@ -4459,23 +4457,18 @@ static int cli_parse_set_server(char **args, char *payload, struct appctx *appct
 
 static int cli_parse_get_weight(char **args, char *payload, struct appctx *appctx, void *private)
 {
-	struct proxy *px;
+	struct proxy *be;
 	struct server *sv;
-	char *line;
+	struct ist be_name, sv_name = ist(args[2]);
 
+	be_name = istsplit(&sv_name, '/');
+	if (!istlen(sv_name))
+		return cli_err(appctx, "Require 'backend/server'.");
 
-	/* split "backend/server" and make <line> point to server */
-	for (line = args[2]; *line; line++)
-		if (*line == '/') {
-			*line++ = '\0';
-			break;
-		}
-
-	if (!*line)
-		return cli_err(appctx, "Require 'backend/server'.\n");
-
-	if (!get_backend_server(args[2], line, &px, &sv))
-		return cli_err(appctx, px ? "No such server.\n" : "No such backend.\n");
+	if (!(be = proxy_be_by_name(ist0(be_name))))
+		return cli_err(appctx, "No such backend.");
+	if (!(sv = server_find_by_name(be, ist0(sv_name))))
+		return cli_err(appctx, "No such server.");
 
 	/* return server's effective weight at the moment */
 	snprintf(trash.area, trash.size, "%d (initial %d)\n", sv->uweight,
@@ -5067,27 +5060,14 @@ static int cli_parse_delete_server(char **args, char *payload, struct appctx *ap
 {
 	struct proxy *be;
 	struct server *srv;
-	char *be_name, *sv_name;
 	struct server *prev_del;
+	struct ist be_name, sv_name;
 
 	if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
 		return 1;
 
 	++args;
 
-	sv_name = be_name = args[1];
-	/* split backend/server arg */
-	while (*sv_name && *(++sv_name)) {
-		if (*sv_name == '/') {
-			*sv_name = '\0';
-			++sv_name;
-			break;
-		}
-	}
-
-	if (!*sv_name)
-		return cli_err(appctx, "Require 'backend/server'.");
-
 	/* The proxy servers list is currently not protected by a lock so this
 	 * requires thread isolation. In addition, any place referencing the
 	 * server about to be deleted would be unsafe after our operation, so
@@ -5096,13 +5076,18 @@ static int cli_parse_delete_server(char **args, char *payload, struct appctx *ap
 	 */
 	thread_isolate_full();
 
-	get_backend_server(be_name, sv_name, &be, &srv);
-	if (!be) {
-		cli_err(appctx, "No such backend.");
+	sv_name = ist(args[1]);
+	be_name = istsplit(&sv_name, '/');
+	if (!istlen(sv_name)) {
+		cli_err(appctx, "Require 'backend/server'.");
 		goto out;
 	}
 
-	if (!srv) {
+	if (!(be = proxy_be_by_name(ist0(be_name)))) {
+		cli_err(appctx, "No such backend.");
+		goto out;
+	}
+	if (!(srv = server_find_by_name(be, ist0(sv_name)))) {
 		cli_err(appctx, "No such server.");
 		goto out;
 	}