On 17/04/23 10:39, Sergey Bugaev via Libc-alpha wrote:
> Signed-off-by: Sergey Bugaev <buga...@gmail.com>
Add some description of what the test is accomplishing here.
Some small nits below, the patch LGTM.
> ---
>
> This is an attempt to write a test, roughly based on
> sysdeps/unix/sysv/linux/tst-scm_rights.c
>
> Please tell me if this needs any changes. For instance, I opted to do
> my own error checking for sendmsg/recvmsg/socketpair, but I could've
> alternatively added xsendmsg/xrecvmsg/xsocketpair. This is also looser
> on the coding style side, e.g. variables are defined mid-function
> instead of upfront, since that's what I saw in tst-scm_rights.c; I can
> get rid of that if that's not intended.
>
> I placed this into the generic socket/ since it should also work on
> Linux (though I only tested it on i686-gnu myself). Please tell me if
> this would be better suited for sysdeps/mach/hurd/ instead.
>
> socket/Makefile | 1 +
> socket/tst-cmsg_cloexec.c | 124 ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 125 insertions(+)
> create mode 100644 socket/tst-cmsg_cloexec.c
>
> diff --git a/socket/Makefile b/socket/Makefile
> index fffed7dd..94951ae3 100644
> --- a/socket/Makefile
> +++ b/socket/Makefile
> @@ -35,6 +35,7 @@ tests := \
> tst-accept4 \
> tst-sockopt \
> tst-cmsghdr \
> + tst-cmsg_cloexec \
> # tests
>
> tests-internal := \
> diff --git a/socket/tst-cmsg_cloexec.c b/socket/tst-cmsg_cloexec.c
> new file mode 100644
> index 00000000..237c3db2
> --- /dev/null
> +++ b/socket/tst-cmsg_cloexec.c
> @@ -0,0 +1,124 @@
> +/* Smoke test for MSG_CMSG_CLOEXEC.
> + Copyright (C) 2021-2023 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 <support/xunistd.h>
> +#include <support/check.h>
> +#include <sys/socket.h>
> +#include <sys/un.h>
> +#include <string.h>
> +#include <fcntl.h>
> +
> +static void
> +send_fd (int sockfd, int fd)
> +{
> + /* const */ char data[] = "hello";
Just remove the 'const' comment here.
> + struct iovec iov = { .iov_base = data, .iov_len = sizeof (data) };
> +
> + union
> + {
> + struct cmsghdr header;
> + char bytes[CMSG_SPACE (sizeof (fd))];
> + } cmsg_storage;
> +
> + struct msghdr msg =
> + {
> + .msg_iov = &iov,
> + .msg_iovlen = 1,
> + .msg_control = cmsg_storage.bytes,
> + .msg_controllen = CMSG_LEN (sizeof (fd))
> + };
> +
> + struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg);
> + cmsg->cmsg_level = SOL_SOCKET;
> + cmsg->cmsg_type = SCM_RIGHTS;
> + cmsg->cmsg_len = CMSG_LEN (sizeof (fd));
> + memcpy (CMSG_DATA (cmsg), &fd, sizeof (fd));
> +
> + ssize_t nsent = sendmsg (sockfd, &msg, 0);
> + if (nsent < 0)
> + FAIL_EXIT1 ("sendmsg (%d): %m", sockfd);
> + TEST_COMPARE (nsent, sizeof (data));
> +}
> +
> +static int
> +recv_fd (int sockfd, int flags)
> +{
> + char buffer[100];
> + struct iovec iov = { .iov_base = buffer, .iov_len = sizeof (buffer) };
> +
> + union
> + {
> + struct cmsghdr header;
> + char bytes[100];
> + } cmsg_storage;
> +
> + struct msghdr msg =
> + {
> + .msg_iov = &iov,
> + .msg_iovlen = 1,
> + .msg_control = cmsg_storage.bytes,
> + .msg_controllen = sizeof (cmsg_storage)
> + };
> +
> + ssize_t nrecv = recvmsg (sockfd, &msg, flags);
> + if (nrecv < 0)
> + FAIL_EXIT1 ("recvmsg (%d): %m", sockfd);
> +
> + TEST_COMPARE (msg.msg_controllen, CMSG_LEN (sizeof (int)));
> + struct cmsghdr *cmsg = CMSG_FIRSTHDR (&msg);
> + TEST_COMPARE (cmsg->cmsg_level, SOL_SOCKET);
> + TEST_COMPARE (cmsg->cmsg_type, SCM_RIGHTS);
> + TEST_COMPARE (cmsg->cmsg_len, CMSG_LEN (sizeof (int)));
> +
> + int fd;
> + memcpy (&fd, CMSG_DATA (cmsg), sizeof (fd));
> + return fd;
> +}
> +
> +static int
> +do_test (void)
> +{
> + int sockfd[2];
> + int newfd;
> + int flags;
> + int rc = socketpair (AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0, sockfd);
> + if (rc < 0)
> + FAIL_EXIT1 ("socketpair: %m");
> +
> + send_fd (sockfd[1], STDIN_FILENO);
> + newfd = recv_fd (sockfd[0], 0);
> + TEST_VERIFY_EXIT (newfd > 0);
> + flags = fcntl (newfd, F_GETFD, 0);
> + TEST_VERIFY_EXIT (flags != -1);
> + TEST_VERIFY (!(flags & FD_CLOEXEC));
> + xclose (newfd);
> +
> + send_fd (sockfd[1], STDIN_FILENO);
> + newfd = recv_fd (sockfd[0], MSG_CMSG_CLOEXEC);
> + TEST_VERIFY_EXIT (newfd > 0);
> + flags = fcntl (newfd, F_GETFD, 0);
> + TEST_VERIFY_EXIT (flags != -1);
> + TEST_VERIFY (flags & FD_CLOEXEC);
> + xclose (newfd);
> +
> + xclose (sockfd[0]);
> + xclose (sockfd[1]);
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
