mtr-0.85 fails to build with musl libc

[traviscross]

mtr-0.85 fails to build with musl libc

[James-TR]

I'm going to have a look at how to fix this code along with some people from the musl project, are there any suggestions as to how you would want this handled?

[ncopa]

I'd suggest using the library c-ares for DNS resolution. Possibly making it compile time optional with --disable-dns.

[rewolff]

Could you test the branch "newdns"?

Today three or four reports of "things going wrong" with the self-written internal DNS resolver. I'm getting a bit tired of that....

[James-TR]

@rewolff thanks, I'll happily have a look. Been busy getting patches for a lot of the stuff I'm using upstreamed :)

[James-TR]

checking whether __res_state_ext needs to be defined... yes
checking whether provided __res_state_ext definition can be compiled... no
configure: error: Need definition for struct __res_state_ext but unable to define it.

^ this is as far as I got with the newdns branch, same error as before due to musl not having a resolver like that of glibc

[ncopa]

I get this error:

checking whether provided __res_state_ext definition can be compiled... no
configure: error: Need definition for struct __res_state_ext but unable to define it.

As I understand __anything is for internal libc use only and should not be used (or even exposed) to applications.

That said, it compiles with --disable-ipv6

[ncopa]

the __res_state_ext is apparently not needed for the 'newdns' branch. After removing it it builds and appears to work just fine.

diff --git a/configure.ac b/configure.ac
index d50c253..708db4f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -139,57 +139,6 @@ AC_CHECK_FUNC(getaddrinfo,
        USES_IPV6=yes
 fi])

-AC_DEFUN([NEED_RES_STATE_EXT_TEST_SRC], [
-AC_LANG_PROGRAM([[
-#include <netinet/in.h>
-#include <resolv.h>
-#ifdef __GLIBC__
-#define RESEXTIN6(r,i) (*(r._u._ext.nsaddrs[i]))
-#else
-#define RESEXTIN6(r,i) (r._u._ext.ext->nsaddrs[i].sin6)
-#endif
-]], [[
-struct __res_state res;
-return RESEXTIN6(res,0).sin6_addr.s6_addr[0];
-]])])
-AC_DEFUN([DEFINE_RES_STATE_EXT_TEST_SRC], [
-AC_LANG_PROGRAM([[
-#include <netinet/in.h>
-#include <resolv.h>
-#ifdef __GLIBC__
-#define RESEXTIN6(r,i) (*(r._u._ext.nsaddrs[i]))
-#else
-#define RESEXTIN6(r,i) (r._u._ext.ext->nsaddrs[i].sin6)
-struct __res_state_ext {
-       union res_sockaddr_union nsaddrs[MAXNS];
-       struct sort_list {
-               int     af;
-               union {
-                       struct in_addr  ina;
-                       struct in6_addr in6a;
-               } addr, mask;
-       } sort_list[MAXRESOLVSORT];
-       char nsuffix[64];
-       char nsuffix2[64];
-};
-#endif
-]], [[
-struct __res_state res;
-return RESEXTIN6(res,0).sin6_addr.s6_addr[0];
-]])])
-if test "x$USES_IPV6" = "xyes"; then
-       AC_MSG_CHECKING([whether __res_state_ext needs to be defined])
-       AC_COMPILE_IFELSE([NEED_RES_STATE_EXT_TEST_SRC],
-               [AC_MSG_RESULT([no])],
-               [AC_MSG_RESULT([yes])
-               AC_MSG_CHECKING([whether provided __res_state_ext definition can be compiled])
-               AC_COMPILE_IFELSE([DEFINE_RES_STATE_EXT_TEST_SRC],
-                       [AC_MSG_RESULT([yes])
-                       AC_DEFINE(NEED_RES_STATE_EXT, 1, [Define if struct __res_state_ext needs to be defined.])],
-                       [AC_MSG_RESULT([no])
-                       AC_MSG_ERROR(Need definition for struct __res_state_ext but unable to define it.)])])
-fi
-
 AC_CHECK_DECLS(errno, , , [[
 #include <errno.h>
 #include <sys/errno.h>

[aquerubin]

On Fri, 19 Dec 2014, James Taylor wrote:

checking whether __res_state_ext needs to be defined... yes
checking whether provided __res_state_ext definition can be compiled... no
configure: error: Need definition for struct __res_state_ext but unable to define it.
^ this is as far as I got with the newdns branch, same error as before due to musl not having a resolver like that of glibc

I don't think those checks are needed for the newdns branch any more.

Antonio Querubin
e-mail: [email protected]
xmpp: [email protected]

[rewolff]

yeah. removed and uploaded.