#29 Build failure with GNU libc 2.8

[Jérémie Corbier]

Latest versions of the GNU libc don't provide struct in6_pktinfo by default. One has to #define _GNU_SOURCE so that this structure gets declared. See:

http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc/inet/netinet/in.h.diff?r1=1.55&r2=1.56&cvsroot=glibc

This breaks wide-dhcpv6 builds on systems using latest versions of the GNU libc.

[Jérémie Corbier]

Please also note that defining _GNU_SOURCE globally does not work since there is a name conflict between GNU libc GNU-specific dprintf function and wide-dhcpv6 debug messages function.

[Jérémie Corbier]

I worked around this issue by copying struct in6_pktinfo definition into dhcp6.h in the Debian package.

[retvari]

Here is a patch to detect at configure time whether libc defines "struct in6_pktinfo":

diff --git wide/configure.in wide/configure.in
index 59dd84e..8543b35 100644
--- wide/configure.in
+++ wide/configure.in
@@ -236,4 +236,11 @@ AC_SUBST(group)

AC_CHECK_HEADERS(stdarg.h)

+AC_MSG_CHECKING(whether libc defines struct in6_pktinfo)
+AC_TRY_COMPILE([#include <netinet/in.h>],
+ [struct in6_pktinfo p6;],
+ [AC_MSG_RESULT(yes)
+ CFLAGS="$CFLAGS -DHAVE_IN6_PKTINFO"],
+ [AC_MSG_RESULT(no)])
+
AC_OUTPUT(Makefile)
diff --git wide/dhcp6.h wide/dhcp6.h
index 6afb517..5280a46 100644
--- wide/dhcp6.h
+++ wide/dhcp6.h
@@ -108,6 +108,13 @@ typedef uint64_t u_int64_t;
#define DHCP6_IRT_DEFAULT 86400 /* 1 day */
#define DHCP6_IRT_MINIMUM 600

+#ifndef HAVE_IN6_PKTINFO
+struct in6_pktinfo {
+ struct in6_addr ipi6_addr; /* src/dst IPv6 address */
+ unsigned int ipi6_ifindex; /* send/recv interface index */
+};
+#endif /* HAVE_IN6_PKTINFO */
+
/* DUID: DHCP unique Identifier */
struct duid {
size_t duid_len; /* length */