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-rw-r--r--nss/bug-erange.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/nss/bug-erange.c b/nss/bug-erange.c
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index 0000000000..5e535a0fe4
--- /dev/null
+++ b/nss/bug-erange.c
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+/* Test case for gethostbyname_r bug when buffer expansion required.  */
+
+#include <netdb.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int
+main (void)
+{
+  const char *host = "www.gnu.org";
+
+  /* This code approximates the example code in the library manual.  */
+
+  struct hostent hostbuf, *hp;
+  size_t hstbuflen;
+  char *tmphstbuf;
+  int res;
+  int herr;
+
+  hstbuflen = 16;		/* Make it way small to ensure ERANGE.  */
+  /* Allocate buffer, remember to free it to avoid memory leakage.  */
+  tmphstbuf = malloc (hstbuflen);
+
+  while ((res = gethostbyname_r (host, &hostbuf, tmphstbuf, hstbuflen,
+                                 &hp, &herr)) == ERANGE)
+    {
+      /* Enlarge the buffer.  */
+      hstbuflen *= 2;
+      tmphstbuf = realloc (tmphstbuf, hstbuflen);
+    }
+
+  if (res != 0 || hp == NULL)
+    {
+      printf ("gethostbyname_r failed: %s (errno: %m)\n", strerror (res));
+      return 1;
+    }
+
+  printf ("Got: %s %s\n", hp->h_name,
+	  inet_ntoa (*(struct in_addr *) hp->h_addr));
+  return 0;
+}