[NetworkManager-openvpn] helper: cleanup parsing foreign_option_* environment variables

[Thomas Haller <thaller src gnome org>]

commit 67d9ebb4f2b58287162284619168224afc04d9e0
Author: Thomas Haller <thaller redhat com>
Date:   Thu Apr 23 09:47:26 2020 +0200

    helper: cleanup parsing foreign_option_* environment variables
    
    There is no need to restrict parsing to 256 variables. Just continue
    iterating until we find a variable that is missing.
    
    Also, don't use magical numbers
    
      -         tmp += 12; /* strlen ("dhcp-option ") */
      +         tmp += NM_STRLEN ("dhcp-option ");

 src/nm-openvpn-service-openvpn-helper.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)
---
diff --git a/src/nm-openvpn-service-openvpn-helper.c b/src/nm-openvpn-service-openvpn-helper.c
index 1e02cf7..1bcf517 100644
--- a/src/nm-openvpn-service-openvpn-helper.c
+++ b/src/nm-openvpn-service-openvpn-helper.c
@@ -213,7 +213,12 @@ parse_addr_list (GPtrArray *array4, GPtrArray *array6, const char *str)
 static inline gboolean
 is_domain_valid (const char *str)
 {
-       return (str && (strlen(str) >= 1) && (strlen(str) <= 255));
+       gsize l;
+
+       if (!str)
+               return FALSE;
+       l = strlen (str);
+       return (l >= 1 && l <= 255);
 }
 
 static GVariant *
@@ -673,27 +678,29 @@ main (int argc, char *argv[])
        dns6_list = g_ptr_array_new ();
        nbns_list = g_ptr_array_new ();
 
-       for (i = 1; i < 256; i++) {
-               char *env_name;
+       for (i = 1; TRUE; i++) {
+               char env_name[NM_STRLEN ("foreign_option_") + 1 + 40];
+
+               nm_sprintf_buf (env_name, "foreign_option_%d", i);
 
-               env_name = g_strdup_printf ("foreign_option_%d", i);
                tmp = getenv (env_name);
-               g_free (env_name);
 
-               if (!tmp || strlen (tmp) < 1)
+               if (   !tmp
+                   || !tmp[0])
                        break;
 
                if (!g_str_has_prefix (tmp, "dhcp-option "))
                        continue;
 
-               tmp += 12; /* strlen ("dhcp-option ") */
+               tmp += NM_STRLEN ("dhcp-option ");
 
                if (g_str_has_prefix (tmp, "DNS "))
-                       parse_addr_list (dns4_list, dns6_list, tmp + 4);
+                       parse_addr_list (dns4_list, dns6_list, &tmp[NM_STRLEN ("DNS ")]);
                else if (g_str_has_prefix (tmp, "WINS "))
-                       parse_addr_list (nbns_list, NULL, tmp + 5);
-               else if (g_str_has_prefix (tmp, "DOMAIN ") && is_domain_valid (tmp + 7))
-                       g_ptr_array_add (dns_domains, tmp + 7);
+                       parse_addr_list (nbns_list, NULL, &tmp[NM_STRLEN ("WINS ")]);
+               else if (   g_str_has_prefix (tmp, "DOMAIN ")
+                        && is_domain_valid (&tmp[NM_STRLEN ("DOMAIN ")]))
+                       g_ptr_array_add (dns_domains, &tmp[NM_STRLEN ("DOMAIN ")]);
        }
 
        if (dns4_list->len) {