+#ifndef HAVE_ASPRINTF
+extern int asprintf(char **, const char *, ...);
+#endif
+
+#ifndef HAVE_STRUCT_ADDRINFO
+struct addrinfo {
+ int ai_flags; /* AI_PASSIVE, AI_CANONNAME */
+ int ai_family; /* PF_xxx */
+ int ai_socktype; /* SOCK_xxx */
+ int ai_protocol; /* 0 or IPPROTO_xxx for IPv4 and IPv6 */
+ size_t ai_addrlen; /* length of ai_addr */
+ char *ai_canonname; /* canonical name for hostname */
+ struct sockaddr *ai_addr; /* binary address */
+ struct addrinfo *ai_next; /* next structure in linked list */
+};
+#endif /* !HAVE_STRUCT_ADDRINFO */
+
+#ifndef HAVE_GETADDRINFO
+int getaddrinfo(const char *hostname, const char *servname,
+ const struct addrinfo *hints, struct addrinfo **res);
+#endif /* !HAVE_GETADDRINFO */
+
+#ifndef HAVE_GAI_STRERROR
+char *gai_strerror(int ecode);
+#endif /* !HAVE_GAI_STRERROR */
+
+#ifndef HAVE_FREEADDRINFO
+void freeaddrinfo(struct addrinfo *ai);
+#endif /* !HAVE_FREEADDRINFO */
+
+#ifndef HAVE_GETNAMEINFO
+int getnameinfo(const struct sockaddr *sa, size_t salen, char *host,
+ size_t hostlen, char *serv, size_t servlen, int flags);
+#endif /* !HAVE_GETNAMEINFO */
+
+#ifndef NI_MAXSERV
+# define NI_MAXSERV 32
+#endif /* !NI_MAXSERV */
+#ifndef NI_MAXHOST
+# define NI_MAXHOST 1025
+#endif /* !NI_MAXHOST */
+
+#ifndef AI_PASSIVE
+# define AI_PASSIVE 1
+# define AI_CANONNAME 2
+#endif
+
+#ifndef NI_NUMERICHOST
+# define NI_NUMERICHOST 2
+# define NI_NAMEREQD 4
+# define NI_NUMERICSERV 8
+#endif
+