Linux 6.1 adds a define IPPROTO_L2TP to its include/uapi/linux/in.h
(not strictly a new constant, since it's moved from
include/uapi/linux/l2tp.h). Add this constant to glibc's
netinet/in.h.
Tested for x86_64.
#define IPPROTO_PIM IPPROTO_PIM
IPPROTO_COMP = 108, /* Compression Header Protocol. */
#define IPPROTO_COMP IPPROTO_COMP
+ IPPROTO_L2TP = 115, /* Layer 2 Tunnelling Protocol. */
+#define IPPROTO_L2TP IPPROTO_L2TP
IPPROTO_SCTP = 132, /* Stream Control Transmission Protocol. */
#define IPPROTO_SCTP IPPROTO_SCTP
IPPROTO_UDPLITE = 136, /* UDP-Lite protocol. */