resolv: Tests for various versions of res_init

14 files changed, 445 insertions, 1 deletions

diff --git a/support/Makefile b/support/Makefile
index 3ce73a6c76..20b0343ade 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -35,8 +35,11 @@ libsupport-routines = \
   oom_error \
   resolv_test \
   set_fortify_handler \
+  support-xstat \
   support_become_root \
+  support_can_chroot \
   support_capture_subprocess \
+  support_capture_subprocess_check \
   support_enter_network_namespace \
   support_format_address_family \
   support_format_addrinfo \
@@ -44,8 +47,11 @@ libsupport-routines = \
   support_format_herrno \
   support_format_hostent \
   support_format_netent \
+  support_isolate_in_subprocess \
   support_record_failure \
   support_run_diff \
+  support_shared_allocate \
+  support_write_file_string \
   support_test_main \
   support_test_verify_impl \
   temp_file \
@@ -55,6 +61,7 @@ libsupport-routines = \
   xasprintf \
   xbind \
   xcalloc \
+  xchroot \
   xclose \
   xconnect \
   xdup2 \
@@ -65,8 +72,10 @@ libsupport-routines = \
   xlisten \
   xmalloc \
   xmemstream \
+  xmkdir \
   xmmap \
   xmunmap \
+  xopen \
   xpipe \
   xpoll \
   xpthread_attr_destroy \
diff --git a/support/capture_subprocess.h b/support/capture_subprocess.h
index be5d34fbe2..43caf9bce4 100644
--- a/support/capture_subprocess.h
+++ b/support/capture_subprocess.h
@@ -39,4 +39,23 @@ struct support_capture_subprocess support_capture_subprocess
    support_capture_subprocess.  */
 void support_capture_subprocess_free (struct support_capture_subprocess *);
 
+enum support_capture_allow
+{
+  /* No output is allowed.  */
+  sc_allow_none = 0x01,
+  /* Output to stdout is permitted.  */
+  sc_allow_stdout = 0x02,
+  /* Output to standard error is permitted.  */
+  sc_allow_stderr = 0x04,
+};
+
+/* Check that the subprocess exited with STATUS and that only the
+   allowed outputs happened.  ALLOWED is a combination of
+   support_capture_allow flags.  Report errors under the CONTEXT
+   message.  */
+void support_capture_subprocess_check (struct support_capture_subprocess *,
+                                       const char *context, int status,
+                                       int allowed)
+  __attribute__ ((nonnull (1, 2)));
+
 #endif /* SUPPORT_CAPTURE_SUBPROCESS_H */
diff --git a/support/namespace.h b/support/namespace.h
index 6bc82d619b..e1ccaa1ef0 100644
--- a/support/namespace.h
+++ b/support/namespace.h
@@ -35,6 +35,13 @@ __BEGIN_DECLS
    single-threaded processes.  */
 bool support_become_root (void);
 
+/* Return true if this process can perform a chroot operation.  In
+   general, this is only possible if support_become_root has been
+   called.  Note that the actual test is performed in a subprocess,
+   after fork, so that the file system root of the original process is
+   not changed.  */
+bool support_can_chroot (void);
+
 /* Enter a network namespace (and a UTS namespace if possible) and
    configure the loopback interface.  Return true if a network
    namespace could be created.  Print diagnostics to standard output.
@@ -48,6 +55,11 @@ bool support_enter_network_namespace (void);
    UTS namespace.  */
 bool support_in_uts_namespace (void);
 
+/* Invoke CALLBACK (CLOSURE) in a subprocess created using fork.
+   Terminate the calling process if the subprocess exits with a
+   non-zero exit status.  */
+void support_isolate_in_subprocess (void (*callback) (void *), void *closure);
+
 __END_DECLS
 
 #endif
diff --git a/support/support-xstat.c b/support/support-xstat.c
new file mode 100644
index 0000000000..86a81ec601
--- /dev/null
+++ b/support/support-xstat.c
@@ -0,0 +1,30 @@
+/* stat64 with error checking.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* NB: Non-standard file name to avoid sysdeps override for xstat.  */
+
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <sys/stat.h>
+
+void
+xstat (const char *path, struct stat64 *result)
+{
+  if (stat64 (path, result) != 0)
+    FAIL_EXIT1 ("stat64 (\"%s\"): %m", path);
+}
diff --git a/support/support.h b/support/support.h
index 7292e2a564..4b5f04c2cc 100644
--- a/support/support.h
+++ b/support/support.h
@@ -44,6 +44,21 @@ void set_fortify_handler (void (*handler) (int sig));
 void oom_error (const char *function, size_t size)
   __attribute__ ((nonnull (1)));
 
+/* Return a pointer to a memory region of SIZE bytes.  The memory is
+   initialized to zero and will be shared with subprocesses (across
+   fork).  The returned pointer must be freed using
+   support_shared_free; it is not compatible with the malloc
+   functions.  */
+void *support_shared_allocate (size_t size);
+
+/* Deallocate a pointer returned by support_shared_allocate.  */
+void support_shared_free (void *);
+
+/* Write CONTENTS to the file PATH.  Create or truncate the file as
+   needed.  The file mode is 0666 masked by the umask.  Terminate the
+   process on error.  */
+void support_write_file_string (const char *path, const char *contents);
+
 /* Error-checking wrapper functions which terminate the process on
    error.  */
 
diff --git a/support/support_can_chroot.c b/support/support_can_chroot.c
new file mode 100644
index 0000000000..0dfd2deb54
--- /dev/null
+++ b/support/support_can_chroot.c
@@ -0,0 +1,65 @@
+/* Return true if the process can perform a chroot operation.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stdio.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/support.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <xunistd.h>
+
+static void
+callback (void *closure)
+{
+  int *result = closure;
+  struct stat64 before;
+  xstat ("/dev", &before);
+  if (chroot ("/dev") != 0)
+    {
+      *result = errno;
+      return;
+    }
+  struct stat64 after;
+  xstat ("/", &after);
+  TEST_VERIFY (before.st_dev == after.st_dev);
+  TEST_VERIFY (before.st_ino == after.st_ino);
+  *result = 0;
+}
+
+bool
+support_can_chroot (void)
+{
+  int *result = support_shared_allocate (sizeof (*result));
+  *result = 0;
+  support_isolate_in_subprocess (callback, result);
+  bool ok = *result == 0;
+  if (!ok)
+    {
+      static bool already_warned;
+      if (!already_warned)
+        {
+          already_warned = true;
+          errno = *result;
+          printf ("warning: this process does not support chroot: %m\n");
+        }
+    }
+  support_shared_free (result);
+  return ok;
+}
diff --git a/support/support_capture_subprocess_check.c b/support/support_capture_subprocess_check.c
new file mode 100644
index 0000000000..708c89f331
--- /dev/null
+++ b/support/support_capture_subprocess_check.c
@@ -0,0 +1,67 @@
+/* Verify capture output from a subprocess.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <support/capture_subprocess.h>
+#include <support/check.h>
+
+static void
+print_context (const char *context, bool *failed)
+{
+  if (*failed)
+    /* Do not duplicate message.  */
+    return;
+  support_record_failure ();
+  printf ("error: subprocess failed: %s\n", context);
+}
+
+void
+support_capture_subprocess_check (struct support_capture_subprocess *proc,
+                                  const char *context, int status,
+                                  int allowed)
+{
+  TEST_VERIFY ((allowed & sc_allow_none)
+               || (allowed & sc_allow_stdout)
+               || (allowed & sc_allow_stderr));
+  TEST_VERIFY (!((allowed & sc_allow_none)
+                 && ((allowed & sc_allow_stdout)
+                     || (allowed & sc_allow_stderr))));
+
+  bool failed = false;
+  if (proc->status != status)
+    {
+      print_context (context, &failed);
+      printf ("error:   expected exit status: %d\n", status);
+      printf ("error:   actual exit status:   %d\n", status);
+    }
+  if (!(allowed & sc_allow_stdout) && proc->out.length != 0)
+    {
+      print_context (context, &failed);
+      printf ("error:   unexpected output from subprocess\n");
+      fwrite (proc->out.buffer, proc->out.length, 1, stdout);
+      puts ("\n");
+    }
+  if (!(allowed & sc_allow_stderr) && proc->err.length != 0)
+    {
+      print_context (context, &failed);
+      printf ("error:   unexpected error output from subprocess\n");
+      fwrite (proc->err.buffer, proc->err.length, 1, stdout);
+      puts ("\n");
+    }
+}
diff --git a/support/support_isolate_in_subprocess.c b/support/support_isolate_in_subprocess.c
new file mode 100644
index 0000000000..cf48614383
--- /dev/null
+++ b/support/support_isolate_in_subprocess.c
@@ -0,0 +1,38 @@
+/* Run a function in a subprocess.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xunistd.h>
+
+void
+support_isolate_in_subprocess (void (*callback) (void *), void *closure)
+{
+  pid_t pid = xfork ();
+  if (pid == 0)
+    {
+      /* Child process.  */
+      callback (closure);
+      _exit (0);
+    }
+
+  /* Parent process.  */
+  int status;
+  xwaitpid (pid, &status, 0);
+  if (status != 0)
+    FAIL_EXIT1 ("child process exited with status %d", status);
+}
diff --git a/support/support_shared_allocate.c b/support/support_shared_allocate.c
new file mode 100644
index 0000000000..61d088e8cf
--- /dev/null
+++ b/support/support_shared_allocate.c
@@ -0,0 +1,57 @@
+/* Allocate a memory region shared across processes.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stddef.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+#include <sys/mman.h>
+
+/* Header for the allocation.  It contains the size of the allocation
+   for subsequent unmapping.  */
+struct header
+{
+  size_t total_size;
+  char data[] __attribute__ ((aligned (__alignof__ (max_align_t))));
+};
+
+void *
+support_shared_allocate (size_t size)
+{
+  size_t total_size = size + offsetof (struct header, data);
+  if (total_size < size)
+    {
+      errno = ENOMEM;
+      oom_error (__func__, size);
+      return NULL;
+    }
+  else
+    {
+      struct header *result = xmmap (NULL, total_size, PROT_READ | PROT_WRITE,
+                                     MAP_ANONYMOUS | MAP_SHARED, -1);
+      result->total_size = total_size;
+      return &result->data;
+    }
+}
+
+void
+support_shared_free (void *data)
+{
+  struct header *header = data - offsetof (struct header, data);
+  xmunmap (header, header->total_size);
+}
diff --git a/support/support_write_file_string.c b/support/support_write_file_string.c
new file mode 100644
index 0000000000..48e89597f3
--- /dev/null
+++ b/support/support_write_file_string.c
@@ -0,0 +1,39 @@
+/* Write a string to a file.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <fcntl.h>
+#include <string.h>
+#include <support/check.h>
+#include <xunistd.h>
+
+void
+support_write_file_string (const char *path, const char *contents)
+{
+  int fd = xopen (path, O_CREAT | O_TRUNC | O_WRONLY, 0666);
+  const char *end = contents + strlen (contents);
+  for (const char *p = contents; p < end; )
+    {
+      ssize_t ret = write (fd, p, end - p);
+      if (ret < 0)
+        FAIL_EXIT1 ("cannot write to \"%s\": %m", path);
+      if (ret == 0)
+        FAIL_EXIT1 ("zero-length write to \"%s\"", path);
+      p += ret;
+    }
+  xclose (fd);
+}
diff --git a/support/xchroot.c b/support/xchroot.c
new file mode 100644
index 0000000000..abcc299e00
--- /dev/null
+++ b/support/xchroot.c
@@ -0,0 +1,28 @@
+/* chroot with error checking.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <sys/stat.h>
+
+void
+xchroot (const char *path)
+{
+  if (chroot (path) != 0)
+    FAIL_EXIT1 ("chroot (\"%s\"): %m", path);
+}
diff --git a/support/xmkdir.c b/support/xmkdir.c
new file mode 100644
index 0000000000..ea17d49391
--- /dev/null
+++ b/support/xmkdir.c
@@ -0,0 +1,28 @@
+/* mkdir with error checking.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <sys/stat.h>
+
+void
+xmkdir (const char *path, mode_t mode)
+{
+  if (mkdir (path, mode) != 0)
+    FAIL_EXIT1 ("mkdir (\"%s\", 0%o): %m", path, mode);
+}
diff --git a/support/xopen.c b/support/xopen.c
new file mode 100644
index 0000000000..7f033a03a7
--- /dev/null
+++ b/support/xopen.c
@@ -0,0 +1,30 @@
+/* open64 with error checking.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <fcntl.h>
+
+int
+xopen (const char *path, int flags, mode_t mode)
+{
+  int ret = open64 (path, flags, mode);
+  if (ret < 0)
+    FAIL_EXIT1 ("open64 (\"%s\", 0x%x, 0%o): %m", path, flags, mode);
+  return ret;
+}
diff --git a/support/xunistd.h b/support/xunistd.h
index 7c14bda7be..151d743e1f 100644
--- a/support/xunistd.h
+++ b/support/xunistd.h
@@ -22,15 +22,22 @@
 #ifndef SUPPORT_XUNISTD_H
 #define SUPPORT_XUNISTD_H
 
-#include <unistd.h>
 #include <sys/cdefs.h>
+#include <sys/types.h>
+#include <unistd.h>
 
 __BEGIN_DECLS
 
+struct stat64;
+
 pid_t xfork (void);
 pid_t xwaitpid (pid_t, int *status, int flags);
 void xpipe (int[2]);
 void xdup2 (int, int);
+int xopen (const char *path, int flags, mode_t);
+void xstat (const char *path, struct stat64 *);
+void xmkdir (const char *path, mode_t);
+void xchroot (const char *path);
 
 /* Close the file descriptor.  Ignore EINTR errors, but terminate the
    process on other errors.  */