NTLM tests: boost coverage by forcing the hostname

A shared library tests/libtest/.libs/lihostname.so is preloaded in NTLM
test-cases to override the system implementation of gethostname().  It
makes it possible to test the NTLM authentication for exact match, and
this way test the implementation of MD4 and DES.

If LD_PRELOAD doesn't work, a debug build willl also workk as debug
builds are now made to prefer a specific environment variable and will
then return that content as host name instead of the actual one.

Kamil wrote the bulk of this, Daniel Stenberg polished it.

6 files changed, 100 insertions, 2 deletions

diff --git a/tests/libtest/.gitignore b/tests/libtest/.gitignore
index 3311a821e..cabcb671c 100644
--- a/tests/libtest/.gitignore
+++ b/tests/libtest/.gitignore
@@ -1,2 +1,2 @@
+chkhostname
 lib5[0-9][0-9]
-
diff --git a/tests/libtest/Makefile.am b/tests/libtest/Makefile.am
index 70b0f12a4..2a0e3eaa4 100644
--- a/tests/libtest/Makefile.am
+++ b/tests/libtest/Makefile.am
@@ -53,6 +53,16 @@ endif
 EXTRA_DIST = test75.pl test307.pl test610.pl test613.pl test1013.pl	\
 test1022.pl Makefile.inc
 
+if STATICLIB
+# this means no shared option is enabled so we can disable the LD_PRELOAD
+# attempt
+libhostname_la_CFLAGS = -DDISABLE_PRELOAD
+endif
+
+# we force our own host name, in order to make some tests machine independent
+lib_LTLIBRARIES = libhostname.la
+libhostname_la_SOURCES = sethostname.c
+
 # Dependencies (may need to be overriden)
 LDADD = $(top_builddir)/lib/libcurl.la
 DEPENDENCIES = $(top_builddir)/lib/libcurl.la
diff --git a/tests/libtest/Makefile.inc b/tests/libtest/Makefile.inc
index 814c01e6c..28ed6831c 100644
--- a/tests/libtest/Makefile.inc
+++ b/tests/libtest/Makefile.inc
@@ -12,7 +12,9 @@ noinst_PROGRAMS = lib500 lib501 lib502 lib503 lib504 lib505 lib506	\
   lib529 lib530 lib532 lib533 lib536 lib537 lib540 lib541 lib542 lib543 \
   lib544 lib545 lib547 lib548 lib549 lib552 lib553 lib554 lib555 lib556 \
   lib539 lib557 lib558 lib559 lib560 lib562 lib564 lib565 lib566 lib567 \
-  lib568 lib569 lib570 lib571 lib572 lib573
+  lib568 lib569 lib570 lib571 lib572 lib573 chkhostname
+
+chkhostname_SOURCES = chkhostname.c $(top_srcdir)/lib/curl_gethostname.c
 
 lib500_SOURCES = lib500.c $(SUPPORTFILES)
 
diff --git a/tests/libtest/chkhostname.c b/tests/libtest/chkhostname.c
new file mode 100644
index 000000000..686eb471a
--- /dev/null
+++ b/tests/libtest/chkhostname.c
@@ -0,0 +1,26 @@
+#include "curl_gethostname.h"
+
+#include <stdio.h>
+
+#define HOSTNAME_MAX 1024
+
+int main(int argc, char *argv[])
+{
+  char buff[HOSTNAME_MAX];
+  if (argc != 2) {
+    printf("Usage: %s EXPECTED_HOSTNAME\n", argv[0]);
+    return 1;
+  }
+
+  if (Curl_gethostname(buff, HOSTNAME_MAX)) {
+    printf("Curl_gethostname() failed\n");
+    return 1;
+  }
+
+  /* compare the name returned by Curl_gethostname() with the expected one */
+  if(strncmp(buff, argv[1], HOSTNAME_MAX)) {
+    printf("got unexpected host name back, LD_PRELOAD failed\n");
+    return 1;
+  }
+  return 0;
+}
diff --git a/tests/libtest/hostname.c b/tests/libtest/hostname.c
new file mode 100644
index 000000000..ca7fccaf8
--- /dev/null
+++ b/tests/libtest/hostname.c
@@ -0,0 +1,32 @@
+/*****************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ */
+
+#include <string.h>
+#include <unistd.h>
+
+#define HOSTNAME "curlhost"
+#define HOSTNAME_LEN sizeof(HOSTNAME)
+
+/* 
+ * we force our own host name, in order to make some tests machine independent
+ */
+int gethostname(char *name, size_t namelen) {
+  char buff[HOSTNAME_LEN + /* terminating zero */ 1];
+  size_t max = (namelen < HOSTNAME_LEN)
+    ? namelen
+    : HOSTNAME_LEN;
+
+  if(!name || !namelen)
+    return -1;
+
+  strcpy(buff, HOSTNAME);
+  buff[max - 1] = '\0';
+  strcpy(name, buff);
+  return 0;
+};
diff --git a/tests/libtest/sethostname.c b/tests/libtest/sethostname.c
new file mode 100644
index 000000000..667f689ae
--- /dev/null
+++ b/tests/libtest/sethostname.c
@@ -0,0 +1,28 @@
+/*****************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define GETHOSTNAME_ENV_VAR "CURL_GETHOSTNAME"
+
+/*
+ * we force our own host name, in order to make some tests machine independent
+ */
+int gethostname(char *name, size_t namelen) {
+  const char *force_hostname = getenv(GETHOSTNAME_ENV_VAR);
+  if(force_hostname) {
+    strncpy(name, force_hostname, namelen);
+    return 0;
+  }
+
+  /* LD_PRELOAD used, but no hostname set, we'll just return a failure */
+  return -1;
+};