1 files changed, 99 insertions, 0 deletions
diff --git a/src/network/gethostbyname2_r.c b/src/network/gethostbyname2_r.c
new file mode 100644
index 00000000..c2ed75b4
--- /dev/null
+++ b/src/network/gethostbyname2_r.c
@@ -0,0 +1,99 @@
+#define _GNU_SOURCE
+
+#include <sys/socket.h>
+#include <netdb.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <errno.h>
+#include <inttypes.h>
+
+int gethostbyname2_r(const char *name, int af,
+	struct hostent *h, char *buf, size_t buflen,
+	struct hostent **res, int *err)
+{
+	struct addrinfo hint = {
+		.ai_family = af==AF_INET6 ? af : AF_INET,
+		.ai_flags = AI_CANONNAME
+	};
+	struct addrinfo *ai, *p;
+	int i;
+	size_t need;
+	const char *canon;
+
+	af = hint.ai_family;
+
+	/* Align buffer */
+	i = (uintptr_t)buf & sizeof(char *)-1;
+	if (i) {
+		if (buflen < sizeof(char *)-i) {
+			errno = ERANGE;
+			return -1;
+		}
+		buf += sizeof(char *)-i;
+		buflen -= sizeof(char *)-i;
+	}
+
+	getaddrinfo(name, 0, &hint, &ai);
+	switch (getaddrinfo(name, 0, &hint, &ai)) {
+	case EAI_NONAME:
+		*err = HOST_NOT_FOUND;
+		return -1;
+	case EAI_AGAIN:
+		*err = TRY_AGAIN;
+		return -1;
+	default:
+	case EAI_MEMORY:
+	case EAI_SYSTEM:
+	case EAI_FAIL:
+		*err = NO_RECOVERY;
+		return -1;
+	case 0:
+		break;
+	}
+
+	h->h_addrtype = af;
+	h->h_length = af==AF_INET6 ? 16 : 4;
+
+	canon = ai->ai_canonname ? ai->ai_canonname : name;
+	need = 4*sizeof(char *);
+	for (i=0, p=ai; p; i++, p=p->ai_next)
+		need += sizeof(char *) + h->h_length;
+	need += strlen(name)+1;
+	need += strlen(canon)+1;
+
+	if (need > buflen) {
+		freeaddrinfo(ai);
+		errno = ERANGE;
+		return -1;
+	}
+
+	h->h_aliases = (void *)buf;
+	buf += 3*sizeof(char *);
+	h->h_addr_list = (void *)buf;
+	buf += (i+1)*sizeof(char *);
+
+	h->h_name = h->h_aliases[0] = buf;
+	strcpy(h->h_name, canon);
+	buf += strlen(h->h_name)+1;
+
+	if (strcmp(h->h_name, name)) {
+		h->h_aliases[1] = buf;
+		strcpy(h->h_aliases[1], name);
+		buf += strlen(h->h_aliases[1])+1;
+	} else h->h_aliases[1] = 0;
+
+	h->h_aliases[2] = 0;
+
+	for (i=0, p=ai; p; i++, p=p->ai_next) {
+		h->h_addr_list[i] = (void *)buf;
+		buf += h->h_length;
+		memcpy(h->h_addr_list[i],
+			&((struct sockaddr_in *)p->ai_addr)->sin_addr,
+			h->h_length);
+	}
+	h->h_addr_list[i] = 0;
+
+	*res = h;
+	freeaddrinfo(ai);
+	return 0;
+}