slirp: clean up conflicts with system headers

Right now, slirp/slirp.h cannot include some system headers and,
indirectly, qemu_socket.h.  Clean this up, and remove a duplicate
prototype that was introduced because of that.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>

slirp/slirp.h

@@ -88,10 +88,6 @@ void *malloc(size_t arg);
 void free(void *ptr);
 #endif
 
-#ifndef HAVE_INET_ATON
-int inet_aton(const char *cp, struct in_addr *ia);
-#endif
-
 #include <fcntl.h>
 #ifndef NO_UNIX_SOCKETS
 #include <sys/un.h>
@@ -144,6 +140,7 @@ int inet_aton(const char *cp, struct in_addr *ia);
 #include "debug.h"
 
 #include "qemu-queue.h"
+#include "qemu_socket.h"
 
 #include "libslirp.h"
 #include "ip.h"
@@ -167,9 +164,6 @@ int inet_aton(const char *cp, struct in_addr *ia);
 #include "bootp.h"
 #include "tftp.h"
 
-/* osdep.c */
-int qemu_socket(int domain, int type, int protocol);
-
 #define ETH_ALEN 6
 #define ETH_HLEN 14
 

slirp/tcp.h

@@ -45,6 +45,7 @@ typedef	uint32_t tcp_seq;
  * TCP header.
  * Per RFC 793, September, 1981.
  */
+#define tcphdr slirp_tcphdr
 struct tcphdr {
 	uint16_t th_sport;              /* source port */
 	uint16_t th_dport;              /* destination port */
@@ -58,12 +59,6 @@ struct tcphdr {
 		th_off:4;		/* data offset */
 #endif
 	uint8_t th_flags;
-#define	TH_FIN	0x01
-#define	TH_SYN	0x02
-#define	TH_RST	0x04
-#define	TH_PUSH	0x08
-#define	TH_ACK	0x10
-#define	TH_URG	0x20
 	uint16_t th_win;                /* window */
 	uint16_t th_sum;                /* checksum */
 	uint16_t th_urp;                /* urgent pointer */
@@ -71,6 +66,16 @@ struct tcphdr {
 
 #include "tcp_var.h"
 
+#ifndef TH_FIN
+#define	TH_FIN	0x01
+#define	TH_SYN	0x02
+#define	TH_RST	0x04
+#define	TH_PUSH	0x08
+#define	TH_ACK	0x10
+#define	TH_URG	0x20
+#endif
+
+#ifndef TCPOPT_EOL
 #define	TCPOPT_EOL		0
 #define	TCPOPT_NOP		1
 #define	TCPOPT_MAXSEG		2
@@ -86,6 +91,7 @@ struct tcphdr {
 
 #define TCPOPT_TSTAMP_HDR	\
     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
+#endif
 
 /*
  * Default maximum segment size for TCP.
@@ -95,10 +101,13 @@ struct tcphdr {
  *
  * We make this 1460 because we only care about Ethernet in the qemu context.
  */
+#undef TCP_MSS
 #define	TCP_MSS	1460
 
+#undef TCP_MAXWIN
 #define	TCP_MAXWIN	65535	/* largest value for (unscaled) window */
 
+#undef TCP_MAX_WINSHIFT
 #define TCP_MAX_WINSHIFT	14	/* maximum window shift */
 
 /*