string-util: add common implementation of function that converts sized character buffers to NUL terminated C strings

2 files changed, 9 insertions, 13 deletions

diff --git a/src/libsystemd-network/dhcp-option.c b/src/libsystemd-network/dhcp-option.c
index 7f49da7c2d..a52259c238 100644
--- a/src/libsystemd-network/dhcp-option.c
+++ b/src/libsystemd-network/dhcp-option.c
@@ -279,6 +279,7 @@ static int parse_options(const uint8_t options[], size_t buflen, uint8_t *overlo
         uint8_t code, len;
         const uint8_t *option;
         size_t offset = 0;
+        int r;
 
         while (offset < buflen) {
                 code = options[offset ++];
@@ -318,13 +319,9 @@ static int parse_options(const uint8_t options[], size_t buflen, uint8_t *overlo
                         if (error_message) {
                                 _cleanup_free_ char *string = NULL;
 
-                                /* Accept a trailing NUL byte */
-                                if (memchr(option, 0, len - 1))
-                                        return -EINVAL;
-
-                                string = memdup_suffix0((const char *) option, len);
-                                if (!string)
-                                        return -ENOMEM;
+                                r = make_cstring((const char*) option, len, MAKE_CSTRING_ALLOW_TRAILING_NUL, &string);
+                                if (r < 0)
+                                        return r;
 
                                 if (!ascii_is_valid(string))
                                         return -EINVAL;
diff --git a/src/libsystemd-network/sd-dhcp-lease.c b/src/libsystemd-network/sd-dhcp-lease.c
index b14ad57071..02c6a6e0d7 100644
--- a/src/libsystemd-network/sd-dhcp-lease.c
+++ b/src/libsystemd-network/sd-dhcp-lease.c
@@ -376,6 +376,8 @@ static int lease_parse_be32(const uint8_t *option, size_t len, be32_t *ret) {
 }
 
 static int lease_parse_string(const uint8_t *option, size_t len, char **ret) {
+        int r;
+
         assert(option);
         assert(ret);
 
@@ -388,12 +390,9 @@ static int lease_parse_string(const uint8_t *option, size_t len, char **ret) {
                  * One trailing NUL byte is OK, we don't mind. See:
                  * https://github.com/systemd/systemd/issues/1337
                  */
-                if (memchr(option, 0, len - 1))
-                        return -EINVAL;
-
-                string = memdup_suffix0((const char *) option, len);
-                if (!string)
-                        return -ENOMEM;
+                r = make_cstring((const char*) option, len, MAKE_CSTRING_ALLOW_TRAILING_NUL, &string);
+                if (r < 0)
+                        return r;
 
                 free_and_replace(*ret, string);
         }