commit 5575daae5099e779bb860b566b4d608418a5b832

Author: Florian Weimer <fweimer@redhat.com>

Date:   Mon Jan 17 10:21:34 2022 +0100

    socket: Add the __sockaddr_un_set function

    Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

    (cherry picked from commit e368b12f6c16b6888dda99ba641e999b9c9643c8)

diff --git a/include/sys/un.h b/include/sys/un.h

index bdbee999806930f4..152afd9fc7426d8b 100644

--- a/include/sys/un.h

+++ b/include/sys/un.h

@@ -1 +1,13 @@

 #include <socket/sys/un.h>

+

+#ifndef _ISOMAC

+

+/* Set ADDR->sun_family to AF_UNIX and ADDR->sun_path to PATHNAME.

+   Return 0 on success or -1 on failure (due to overlong PATHNAME).

+   The caller should always use sizeof (struct sockaddr_un) as the

+   socket address length, disregaring the length of PATHNAME.

+   Only concrete (non-abstract) pathnames are supported.  */

+int __sockaddr_un_set (struct sockaddr_un *addr, const char *pathname)

+  attribute_hidden;

+

+#endif /* _ISOMAC */

diff --git a/socket/Makefile b/socket/Makefile

index 375957601024c12e..c2de11d73ca1e324 100644

--- a/socket/Makefile

+++ b/socket/Makefile

@@ -29,13 +29,17 @@ headers	:= sys/socket.h sys/un.h bits/sockaddr.h bits/socket.h \

 routines := accept bind connect getpeername getsockname getsockopt	\

 	    listen recv recvfrom recvmsg send sendmsg sendto		\

 	    setsockopt shutdown socket socketpair isfdtype opensock	\

-	    sockatmark accept4 recvmmsg sendmmsg

+	    sockatmark accept4 recvmmsg sendmmsg sockaddr_un_set

 tests := \

   tst-accept4 \

   tst-sockopt \

   # tests

+tests-internal := \

+  tst-sockaddr_un_set \

+  # tests-internal

+

 tests-time64 := \

   tst-sockopt-time64 \

   # tests

diff --git a/socket/sockaddr_un_set.c b/socket/sockaddr_un_set.c

new file mode 100644

index 0000000000000000..0bd40dc34e3d7efc

--- /dev/null

+++ b/socket/sockaddr_un_set.c

@@ -0,0 +1,41 @@

+/* Set the sun_path member of struct sockaddr_un.

+   Copyright (C) 2022 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

+   <https://www.gnu.org/licenses/>.  */

+

+#include <errno.h>

+#include <string.h>

+#include <sys/socket.h>

+#include <sys/un.h>

+

+int

+__sockaddr_un_set (struct sockaddr_un *addr, const char *pathname)

+{

+  size_t name_length = strlen (pathname);

+

+  /* The kernel supports names of exactly sizeof (addr->sun_path)

+     bytes, without a null terminator, but userspace does not; see the

+     SUN_LEN macro.  */

+  if (name_length >= sizeof (addr->sun_path))

+    {

+      __set_errno (EINVAL);     /* Error code used by the kernel.  */

+      return -1;

+    }

+

+  addr->sun_family = AF_UNIX;

+  memcpy (addr->sun_path, pathname, name_length + 1);

+  return 0;

+}

diff --git a/socket/tst-sockaddr_un_set.c b/socket/tst-sockaddr_un_set.c

new file mode 100644

index 0000000000000000..29c2a81afda81b5e

--- /dev/null

+++ b/socket/tst-sockaddr_un_set.c

@@ -0,0 +1,62 @@

+/* Test the __sockaddr_un_set function.

+   Copyright (C) 2022 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

+   <https://www.gnu.org/licenses/>.  */

+

+/* Re-compile the function because the version in libc is not

+   exported.  */

+#include "sockaddr_un_set.c"

+

+#include <support/check.h>

+

+static int

+do_test (void)

+{

+  struct sockaddr_un sun;

+

+  memset (&sun, 0xcc, sizeof (sun));

+  __sockaddr_un_set (&sun, "");

+  TEST_COMPARE (sun.sun_family, AF_UNIX);

+  TEST_COMPARE (__sockaddr_un_set (&sun, ""), 0);

+

+  memset (&sun, 0xcc, sizeof (sun));

+  TEST_COMPARE (__sockaddr_un_set (&sun, "/example"), 0);

+  TEST_COMPARE_STRING (sun.sun_path, "/example");

+

+  {

+    char pathname[108];         /* Length of sun_path (ABI constant).  */

+    memset (pathname, 'x', sizeof (pathname));

+    pathname[sizeof (pathname) - 1] = '\0';

+    memset (&sun, 0xcc, sizeof (sun));

+    TEST_COMPARE (__sockaddr_un_set (&sun, pathname), 0);

+    TEST_COMPARE (sun.sun_family, AF_UNIX);

+    TEST_COMPARE_STRING (sun.sun_path, pathname);

+  }

+

+  {

+    char pathname[109];

+    memset (pathname, 'x', sizeof (pathname));

+    pathname[sizeof (pathname) - 1] = '\0';

+    memset (&sun, 0xcc, sizeof (sun));

+    errno = 0;

+    TEST_COMPARE (__sockaddr_un_set (&sun, pathname), -1);

+    TEST_COMPARE (errno, EINVAL);

+  }

+

+  return 0;

+}

+

+#include <support/test-driver.c>