there are two versions of this structure: the BSD version and the GNU
version. previously only the GNU version was supported. the only way
to support both simultaneously is with an anonymous union, which was a
nonstandard extension prior to C11, so some effort is made to avoid
breakage with compilers which do not support anonymous unions.
this commit is based on a patch by Timo Teräs, but with some changes.
in particular, the GNU version of the structure is not exposed unless
_GNU_SOURCE is defined; this both avoids namespace pollution and
dependency on anonymous unions in the default feature profile.
#define SOL_TCP 6
#include <sys/types.h>
#include <sys/socket.h>
#define SOL_TCP 6
#include <sys/types.h>
#include <sys/socket.h>
+#include <endian.h>
+
+typedef u_int32_t tcp_seq;
+#define TH_FIN 0x01
+#define TH_SYN 0x02
+#define TH_RST 0x04
+#define TH_PUSH 0x08
+#define TH_ACK 0x10
+#define TH_URG 0x20
+
+struct tcphdr {
-#include <endian.h>
-struct tcphdr
-{
+#ifdef __GNUC__
+ __extension__
+#endif
+ union { struct {
+
u_int16_t source;
u_int16_t dest;
u_int32_t seq;
u_int16_t source;
u_int16_t dest;
u_int32_t seq;
u_int16_t window;
u_int16_t check;
u_int16_t urg_ptr;
u_int16_t window;
u_int16_t check;
u_int16_t urg_ptr;
+
+ }; struct {
+#endif
+
+ u_int16_t th_sport;
+ u_int16_t th_dport;
+ u_int32_t th_seq;
+ u_int32_t th_ack;
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ u_int8_t th_x2:4;
+ u_int8_t th_off:4;
+#else
+ u_int8_t th_off:4;
+ u_int8_t th_x2:4;
+#endif
+ u_int8_t th_flags;
+ u_int16_t th_win;
+ u_int16_t th_sum;
+ u_int16_t th_urp;
+
+#ifdef _GNU_SOURCE
+ }; };
+#endif
#define TCPI_OPT_TIMESTAMPS 1
#define TCPI_OPT_SACK 2
#define TCPI_OPT_WSCALE 4
#define TCPI_OPT_TIMESTAMPS 1
#define TCPI_OPT_SACK 2
#define TCPI_OPT_WSCALE 4