commit e55acfd1a11b2891e8bb467ac8e147ef58a82ce1
Author: Dmitry Marakasov <amdmi3@amdmi3.ru>
Date:   Fri Oct 7 17:22:12 2016 +0300

commit 8afbeacfce52d43b7ffb92eead2fccfab7f575ba
Author: Dmitry Marakasov <amdmi3@amdmi3.ru>
Date:   Fri Oct 7 17:19:05 2016 +0300

only available with uClibc if the C library is build with NPTL support (sets
__UCLIBC_HAS_THREADS_NATIVE__) and __UCLIBC_HAS_ADVANCED_REALTIME__ set.

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>

Defining _GNU_SOURCE is required to get proper member names in `struct udphdr`
when building against musl. Build error:

  util.c: In function 'RawFillHeaders':
  util.c:481:9: error: 'struct udphdr' has no member named 'source'
       udph->source = htons(portsrc);
           ^
  util.c:482:9: error: 'struct udphdr' has no member named 'dest'
       udph->dest   = htons(portdst);
           ^
  util.c:483:9: error: 'struct udphdr' has no member named 'len'
       udph->len    = htons(sizeof(struct udphdr) + len);
           ^
  util.c:484:9: error: 'struct udphdr' has no member named 'check'
       udph->check  = 0;

Including <sys/types.h> in needed for mode_t, otherwise musl build fails:
  util.h:91:1: error: unknown type name 'mode_t'

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>

Otherwise building multicat in a static context fails:
  aggregartp.c:381: undefined reference to `pthread_self'

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>

Under Linux, the socket will receive all packets for a given multicast
address, from any interface, even if the interface address is specified.
SO_BINDTODEVICE requires the CAP_NET_ADMIN capability.

Patch courtesy of Benjamin Cohen bcohen AT openheadend DOT tv.

reopen everything).

by Benjamin Cohen.