dns: fix discards 'const' qualifier from pointer target type

Since glibc-2.43:

For ISO C23, the functions bsearch, memchr, strchr, strpbrk, strrchr,
strstr, wcschr, wcspbrk, wcsrchr, wcsstr and wmemchr that return pointers
into their input arrays now have definitions as macros that return a
pointer to a const-qualified type when the input argument is a pointer
to a const-qualified type.

fixes:
    src/openvpn/dns.c: In function 'dns_server_addr_parse':
    src/openvpn/dns.c:67:25: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
       67 |     char *first_colon = strchr(addr, ':');
          |                         ^~~~~~
    src/openvpn/dns.c:68:24: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
       68 |     char *last_colon = strrchr(addr, ':');
          |                        ^~~~~~~

Change-Id: I262705189edfbd9aa9a32bcd712840fffa592435
Signed-off-by: Rudi Heitbaum <rudi@heitbaum.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1542
Acked-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20260218214738.27158-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg35730.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 0157e7fb8ae29b637537a6b98ce85217c6daf5a3)

diff --git a/src/openvpn/dns.c b/src/openvpn/dns.c
index 3d24050e3d2cef9dafddaffaf2825262e1e72fbd..747c0db26d13e00827c64a4e5cd735c241d7e107 100644 (file)
--- a/src/openvpn/dns.c
+++ b/src/openvpn/dns.c
@@ -45,7 +45,7 @@
  * @return              True if parsing was successful
  */
 static bool
-dns_server_port_parse(in_port_t *port, char *port_str)
+dns_server_port_parse(in_port_t *port, const char *port_str)
 {
     char *endptr;
     errno = 0;
@@ -71,8 +71,8 @@ dns_server_addr_parse(struct dns_server *server, const char *addr)
     in_port_t port = 0;
     sa_family_t af;
 
-    char *first_colon = strchr(addr, ':');
-    char *last_colon = strrchr(addr, ':');
+    const char *first_colon = strchr(addr, ':');
+    const char *last_colon = strrchr(addr, ':');
 
     if (!first_colon || first_colon == last_colon)
     {
@@ -93,7 +93,7 @@ dns_server_addr_parse(struct dns_server *server, const char *addr)
         if (addr[0] == '[')
         {
             addr += 1;
-            char *bracket = last_colon - 1;
+            const char *bracket = last_colon - 1;
             if (*bracket != ']' || bracket == addr || !dns_server_port_parse(&port, last_colon + 1))
             {
                 return false;