Defined in 2 files as a macro:

• crypto/openssh/defines.h, line 79 (as a macro)
• sys/netinet/ip.h, line 115 (as a macro)

Referenced in 4 files:

• contrib/netcat/netcat.c, line 1250
• crypto/openssh/misc.c, line 1423
• crypto/openssh/regress/netcat.c, line 1216
• sbin/ipfw/ipfw2.c, line 179