C PCAP library unknown types error

Question

I installed the pcap library on my linux system but when including it I get the errors

 /usr/include/pcap/bpf.h:88:1: error: unknown type name ‘u_int’
 /usr/include/pcap/bpf.h:108:2: error: unknown type name ‘u_int’
 /usr/include/pcap/bpf.h:1260:2: error: unknown type name ‘u_short’
 /usr/include/pcap/bpf.h:1261:2: error: unknown type name ‘u_char’
 /usr/include/pcap/bpf.h:1262:2: error: unknown type name ‘u_char’
 In file included from ../src/test.c:1:0:
 /usr/include/pcap/pcap.h:125:2: error: unknown type name ‘u_short’
 /usr/include/pcap/pcap.h:126:2: error: unknown type name ‘u_short’
 /usr/include/pcap/pcap.h:171:2: error: unknown type name ‘u_int’
 ...
 make: *** [src/test.o] Error 1

I included

 #include <pcap/pcap.h>
 #include <sys/types.h>
 #include <pcap-bpf.h>

in the program, what am I missing?

Answer 1

Make sure you do NOT define any of:

• __STRICT_ANSI__
• _ISOC99_SOURCE
• _POSIX_SOURCE
• _POSIX_C_SOURCE
• _XOPEN_SOURCE
• _SVID_SOURCE

when building your program; they may prevent the BSD data types, such as the ones the compile is complaining about, from being defined.

Answer 2

Try adding

     -D_BSD_SOURCE

az a CFLAG to your Makefile.