From 8ee391bbd0610c376e914ddbf236dbd68d5f40cb Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl@samba.org>
Date: Mon, 3 May 2021 22:03:47 +0200
Subject: [PATCH] tevent: Remove single-use ev_str_list_[length|add]

This also adds proper error checks, the previous code could (very
theoretically) have leaked memory if an intermediate _add had failed.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
---
 lib/tevent/tevent.c      | 18 ++++++++++++++++--
 lib/tevent/tevent_util.c | 30 ------------------------------
 lib/tevent/tevent_util.h |  2 --
 3 files changed, 16 insertions(+), 34 deletions(-)

diff --git a/lib/tevent/tevent.c b/lib/tevent/tevent.c
index dbec1821e41..a94bb440b9b 100644
--- a/lib/tevent/tevent.c
+++ b/lib/tevent/tevent.c
@@ -166,14 +166,28 @@ const char **tevent_backend_list(TALLOC_CTX *mem_ctx)
 {
 	const char **list = NULL;
 	struct tevent_ops_list *e;
+	size_t idx = 0;
 
 	tevent_backend_init();
 
 	for (e=tevent_backends;e;e=e->next) {
-		list = ev_str_list_add(list, e->name);
+		idx += 1;
 	}
 
-	talloc_steal(mem_ctx, list);
+	list = talloc_zero_array(mem_ctx, const char *, idx+1);
+	if (list == NULL) {
+		return NULL;
+	}
+
+	idx = 0;
+	for (e=tevent_backends;e;e=e->next) {
+		list[idx] = talloc_strdup(list, e->name);
+		if (list[idx] == NULL) {
+			TALLOC_FREE(list);
+			return NULL;
+		}
+		idx += 1;
+	}
 
 	return list;
 }
diff --git a/lib/tevent/tevent_util.c b/lib/tevent/tevent_util.c
index 16af8f3b908..7519e118ab9 100644
--- a/lib/tevent/tevent_util.c
+++ b/lib/tevent/tevent_util.c
@@ -29,36 +29,6 @@
 #include "tevent_util.h"
 #include <fcntl.h>
 
-/**
-  return the number of elements in a string list
-*/
-size_t ev_str_list_length(const char **list)
-{
-	size_t ret;
-	for (ret=0;list && list[ret];ret++) /* noop */ ;
-	return ret;
-}
-
-/**
-  add an entry to a string list
-*/
-const char **ev_str_list_add(const char **list, const char *s)
-{
-	size_t len = ev_str_list_length(list);
-	const char **ret;
-
-	ret = talloc_realloc(NULL, list, const char *, len+2);
-	if (ret == NULL) return NULL;
-
-	ret[len] = talloc_strdup(ret, s);
-	if (ret[len] == NULL) return NULL;
-
-	ret[len+1] = NULL;
-
-	return ret;
-}
-
-
 /**
  Set a fd into blocking/nonblocking mode. Uses POSIX O_NONBLOCK if available,
  else
diff --git a/lib/tevent/tevent_util.h b/lib/tevent/tevent_util.h
index eef4a00f98b..128c231e25c 100644
--- a/lib/tevent/tevent_util.h
+++ b/lib/tevent/tevent_util.h
@@ -173,9 +173,7 @@ do { \
 
 #endif /* _DLINKLIST_H */
 
-const char **ev_str_list_add(const char **list, const char *s);
 int ev_set_blocking(int fd, bool set);
-size_t ev_str_list_length(const char **list);
 bool ev_set_close_on_exec(int fd);
 
 /* Defined here so we can build against older talloc versions that don't