git: 3267e0815e06 - main - tests/unix: test MSG_PEEK read from a socket that has a descriptor

[Gleb Smirnoff]

The branch main has been updated by glebius:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=3267e0815e0624d6971483b2bd9f3be175771deb

commit 3267e0815e0624d6971483b2bd9f3be175771deb
Author:     Gleb Smirnoff <gleb...@freebsd.org>
AuthorDate: 2025-05-28 19:48:35 +0000
Commit:     Gleb Smirnoff <gleb...@freebsd.org>
CommitDate: 2025-05-29 18:44:52 +0000

    tests/unix: test MSG_PEEK read from a socket that has a descriptor
---
 tests/sys/kern/unix_passfd_test.c | 46 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/tests/sys/kern/unix_passfd_test.c 
b/tests/sys/kern/unix_passfd_test.c
index 74095859d899..8c6a976a0e12 100644
--- a/tests/sys/kern/unix_passfd_test.c
+++ b/tests/sys/kern/unix_passfd_test.c
@@ -544,6 +544,51 @@ ATF_TC_BODY(send_overflow, tc)
        closesocketpair(fd);
 }
 
+/*
+ * Make sure that we do not receive descriptors with MSG_PEEK.
+ */
+ATF_TC_WITHOUT_HEAD(peek);
+ATF_TC_BODY(peek, tc)
+{
+       int fd[2], getfd, putfd, nfds;
+
+       domainsocketpair(fd);
+       tempfile(&putfd);
+       nfds = getnfds();
+       sendfd(fd[0], putfd);
+       ATF_REQUIRE(getnfds() == nfds);
+
+       /* First make MSG_PEEK recvmsg(2)... */
+       char cbuf[CMSG_SPACE(sizeof(int))];
+       char buf[1];
+       struct iovec iov = {
+               .iov_base = buf,
+               .iov_len = sizeof(buf)
+       };
+       struct msghdr msghdr = {
+               .msg_iov = &iov,
+               .msg_iovlen = 1,
+               .msg_control = cbuf,
+               .msg_controllen = sizeof(cbuf),
+       };
+       ATF_REQUIRE(1 == recvmsg(fd[1], &msghdr, MSG_PEEK));
+       for (struct cmsghdr *cmsghdr = CMSG_FIRSTHDR(&msghdr);
+            cmsghdr != NULL; cmsghdr = CMSG_NXTHDR(&msghdr, cmsghdr)) {
+               /* Usually this is some garbage. */
+               printf("level %d type %d len %u\n",
+                   cmsghdr->cmsg_level, cmsghdr->cmsg_type, cmsghdr->cmsg_len);
+       }
+
+       /* ... and make sure we did not receive any descriptors! */
+       ATF_REQUIRE(getnfds() == nfds);
+
+       /* Now really receive a descriptor. */
+       recvfd(fd[1], &getfd, 0);
+       ATF_REQUIRE(getnfds() == nfds + 1);
+       close(putfd);
+       close(getfd);
+       closesocketpair(fd);
+}
 
 /*
  * Send two files.  Then receive them.  Make sure they are returned in the
@@ -997,6 +1042,7 @@ ATF_TP_ADD_TCS(tp)
        ATF_TP_ADD_TC(tp, send_and_shutdown);
        ATF_TP_ADD_TC(tp, send_a_lot);
        ATF_TP_ADD_TC(tp, send_overflow);
+       ATF_TP_ADD_TC(tp, peek);
        ATF_TP_ADD_TC(tp, two_files);
        ATF_TP_ADD_TC(tp, bundle);
        ATF_TP_ADD_TC(tp, bundle_cancel);