dynamically allocate storage for gethostby* buffers

this change shaves ~1k off libc.so bss size, and also avoids hard
errors in the case where the static buffer was not large enough to
hold the result.

this whole framework is really ugly and might should be replaced or at
least heavily overhauled when some changes/factorizations are made to
getaddrinfo internals in the future.

1 files changed, 16 insertions, 5 deletions

diff --git a/src/network/gethostbyname2.c b/src/network/gethostbyname2.c
index 9fbe2647..c9f90da2 100644
--- a/src/network/gethostbyname2.c
+++ b/src/network/gethostbyname2.c
@@ -4,13 +4,24 @@
 #include <netdb.h>
 #include <string.h>
 #include <netinet/in.h>
+#include <errno.h>
+#include <stdlib.h>
 
 struct hostent *gethostbyname2(const char *name, int af)
 {
-	static struct hostent h;
-	static long buf[512/sizeof(long)];
+	static struct hostent *h;
+	size_t size = 63;
 	struct hostent *res;
-	if (gethostbyname2_r(name, af, &h,
-		(void *)buf, sizeof buf, &res, &h_errno)) return 0;
-	return &h;
+	int err;
+	do {
+		free(h);
+		h = malloc(size+=size+1);
+		if (!h) {
+			h_errno = NO_RECOVERY;
+			return 0;
+		}
+		err = gethostbyname2_r(name, af, h,
+			(void *)(h+1), size-sizeof *h, &res, &h_errno);
+	} while (err == ERANGE);
+	return err ? 0 : h;
 }