slirp: drop <Vista compatibility

Since commit 12f8def0e0 (v2.9), qemu
requires Vista. Let's remove some conditional code.

Note that this introduces a missing declaration warning with mingw.
warning: implicit declaration of function 'inet_ntop'

See also: https://sourceforge.net/p/mingw-w64/mailman/message/36473782/

We could workaround it by declaring it ourself depending on __MINGW64_VERSION_*:
WINSOCK_API_LINKAGE INT WSAAPI inet_pton(int Family, PCTSTR pszAddrString, PVOID pAddrBuf);

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

net/slirp.c

@@ -290,17 +290,6 @@ static int net_slirp_init(NetClientState *peer, const char *model,
     }
 #endif
 
-#if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
-    /* No inet_pton helper before Vista... */
-    if (vprefix6) {
-        /* Unsupported */
-        error_setg(errp, "IPv6 prefix not supported");
-        return -1;
-    }
-    memset(&ip6_prefix, 0, sizeof(ip6_prefix));
-    ip6_prefix.s6_addr[0] = 0xfe;
-    ip6_prefix.s6_addr[1] = 0xc0;
-#else
     if (!vprefix6) {
         vprefix6 = "fec0::";
     }
@@ -308,7 +297,6 @@ static int net_slirp_init(NetClientState *peer, const char *model,
         error_setg(errp, "Failed to parse IPv6 prefix");
         return -1;
     }
-#endif
 
     if (!vprefix6_len) {
         vprefix6_len = 64;
@@ -320,10 +308,6 @@ static int net_slirp_init(NetClientState *peer, const char *model,
     }
 
     if (vhost6) {
-#if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
-        error_setg(errp, "IPv6 host not supported");
-        return -1;
-#else
         if (!inet_pton(AF_INET6, vhost6, &ip6_host)) {
             error_setg(errp, "Failed to parse IPv6 host");
             return -1;
@@ -332,17 +316,12 @@ static int net_slirp_init(NetClientState *peer, const char *model,
             error_setg(errp, "IPv6 Host doesn't belong to network");
             return -1;
         }
-#endif
     } else {
         ip6_host = ip6_prefix;
         ip6_host.s6_addr[15] |= 2;
     }
 
     if (vnameserver6) {
-#if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
-        error_setg(errp, "IPv6 DNS not supported");
-        return -1;
-#else
         if (!inet_pton(AF_INET6, vnameserver6, &ip6_dns)) {
             error_setg(errp, "Failed to parse IPv6 DNS");
             return -1;
@@ -351,7 +330,6 @@ static int net_slirp_init(NetClientState *peer, const char *model,
             error_setg(errp, "IPv6 DNS doesn't belong to network");
             return -1;
         }
-#endif
     } else {
         ip6_dns = ip6_prefix;
         ip6_dns.s6_addr[15] |= 3;

slirp/ip6_icmp.c

@@ -74,6 +74,7 @@ void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code)
     Slirp *slirp = m->slirp;
     struct mbuf *t;
     struct ip6 *ip = mtod(m, struct ip6 *);
+    char addrstr[INET6_ADDRSTRLEN];
 
     DEBUG_CALL("icmp6_send_error");
     DEBUG_ARGS(" type = %d, code = %d\n", type, code);
@@ -90,11 +91,8 @@ void icmp6_send_error(struct mbuf *m, uint8_t type, uint8_t code)
     struct ip6 *rip = mtod(t, struct ip6 *);
     rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
     rip->ip_dst = ip->ip_src;
-#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
-    char addrstr[INET6_ADDRSTRLEN];
     inet_ntop(AF_INET6, &rip->ip_dst, addrstr, INET6_ADDRSTRLEN);
     DEBUG_ARG("target = %s", addrstr);
-#endif
 
     rip->ip_nh = IPPROTO_ICMPV6;
     const int error_data_len = MIN(m->m_len,
@@ -222,12 +220,12 @@ void ndp_send_ra(Slirp *slirp)
  */
 void ndp_send_ns(Slirp *slirp, struct in6_addr addr)
 {
-    DEBUG_CALL("ndp_send_ns");
-#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
     char addrstr[INET6_ADDRSTRLEN];
+
     inet_ntop(AF_INET6, &addr, addrstr, INET6_ADDRSTRLEN);
+
+    DEBUG_CALL("ndp_send_ns");
     DEBUG_ARG("target = %s", addrstr);
-#endif
 
     /* Build IPv6 packet */
     struct mbuf *t = m_get(slirp);

slirp/ndp_table.c

@@ -10,15 +10,14 @@
 void ndp_table_add(Slirp *slirp, struct in6_addr ip_addr,
                     uint8_t ethaddr[ETH_ALEN])
 {
+    char addrstr[INET6_ADDRSTRLEN];
     NdpTable *ndp_table = &slirp->ndp_table;
     int i;
 
-    DEBUG_CALL("ndp_table_add");
-#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
-    char addrstr[INET6_ADDRSTRLEN];
     inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
+
+    DEBUG_CALL("ndp_table_add");
     DEBUG_ARG("ip = %s", addrstr);
-#endif
     DEBUG_ARGS(" hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
                ethaddr[0], ethaddr[1], ethaddr[2],
                ethaddr[3], ethaddr[4], ethaddr[5]);
@@ -50,15 +49,14 @@ void ndp_table_add(Slirp *slirp, struct in6_addr ip_addr,
 bool ndp_table_search(Slirp *slirp, struct in6_addr ip_addr,
                       uint8_t out_ethaddr[ETH_ALEN])
 {
+    char addrstr[INET6_ADDRSTRLEN];
     NdpTable *ndp_table = &slirp->ndp_table;
     int i;
 
-    DEBUG_CALL("ndp_table_search");
-#if !defined(_WIN32) || (_WIN32_WINNT >= 0x0600)
-    char addrstr[INET6_ADDRSTRLEN];
     inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
+
+    DEBUG_CALL("ndp_table_search");
     DEBUG_ARG("ip = %s", addrstr);
-#endif
 
     assert(!in6_zero(&ip_addr));