From b20ab2779027cf872d857252b7d9f4355701a83f Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Sun, 23 Jul 2023 16:35:20 +0900
Subject: [PATCH 01/15] lsfd: initialize the ipc table before loading lists of
 unix socket peers via netlink diag

Loading the lists is done in initialize_classes().

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index 7d1d381fd8d..13f6282c7e1 100644
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -2290,11 +2290,15 @@ int main(int argc, char *argv[])
 	if (scols_table_get_column_by_name(ctl.tb, "XMODE"))
 		ctl.show_xmode = 1;
 
-	/* collect data */
+	/* collect data
+	 *
+	 * The call initialize_ipc_table() must come before
+	 * initialize_classes.
+	 */
 	initialize_nodevs();
+	initialize_ipc_table();
 	initialize_classes();
 	initialize_devdrvs();
-	initialize_ipc_table();
 
 	collect_processes(&ctl, pids, n_pids);
 	free(pids);

From 046c5d5a2f4b0b8344cf0cad7e05a68a1e313710 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Fri, 4 Aug 2023 00:51:49 +0900
Subject: [PATCH 02/15] lsfd: make the sock_xinfo layer be able to prepare an
 ipc_class for a given socket

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd-sock.c | 21 ++++++++++++++++++++-
 misc-utils/lsfd-sock.h |  2 ++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/misc-utils/lsfd-sock.c b/misc-utils/lsfd-sock.c
index 5ed133e6523..7da2f61e589 100644
--- a/misc-utils/lsfd-sock.c
+++ b/misc-utils/lsfd-sock.c
@@ -28,7 +28,23 @@
 static void attach_sock_xinfo(struct file *file)
 {
 	struct sock *sock = (struct sock *)file;
+
 	sock->xinfo = get_sock_xinfo(file->stat.st_ino);
+	if (sock->xinfo) {
+		struct ipc *ipc = get_ipc(file);
+		if (ipc)
+			add_endpoint(&sock->endpoint, ipc);
+	}
+}
+
+static const struct ipc_class *sock_get_ipc_class(struct file *file)
+{
+	struct sock *sock = (struct sock *)file;
+
+	if (sock->xinfo && sock->xinfo->class->get_ipc_class)
+		return sock->xinfo->class->get_ipc_class(sock->xinfo, sock);
+
+	return NULL;
 }
 
 static bool sock_fill_column(struct proc *proc __attribute__((__unused__)),
@@ -116,13 +132,13 @@ static bool sock_fill_column(struct proc *proc __attribute__((__unused__)),
 static void init_sock_content(struct file *file)
 {
 	int fd;
+	struct sock *sock = (struct sock *)file;
 
 	assert(file);
 
 	fd = file->association;
 
 	if (fd >= 0 || fd == -ASSOC_MEM || fd == -ASSOC_SHM) {
-		struct sock *sock = (struct sock *)file;
 		char path[PATH_MAX] = {'\0'};
 		char buf[256];
 		ssize_t len;
@@ -143,6 +159,8 @@ static void init_sock_content(struct file *file)
 			sock->protoname = xstrdup(buf);
 		}
 	}
+
+	init_endpoint(&sock->endpoint);
 }
 
 static void free_sock_content(struct file *file)
@@ -173,4 +191,5 @@ const struct file_class sock_class = {
 	.free_content = free_sock_content,
 	.initialize_class = initialize_sock_class,
 	.finalize_class = finalize_sock_class,
+	.get_ipc_class = sock_get_ipc_class,
 };
diff --git a/misc-utils/lsfd-sock.h b/misc-utils/lsfd-sock.h
index 61bdaeb7e3a..50360b70351 100644
--- a/misc-utils/lsfd-sock.h
+++ b/misc-utils/lsfd-sock.h
@@ -43,6 +43,7 @@ struct sock {
 	struct file file;
 	char *protoname;
 	struct sock_xinfo *xinfo;
+	struct ipc_endpoint endpoint;
 };
 
 struct sock_xinfo_class {
@@ -60,6 +61,7 @@ struct sock_xinfo_class {
 			    int,
 			    size_t,
 			    char **str);
+	struct ipc_class *(*get_ipc_class)(struct sock_xinfo *, struct sock *);
 
 	void (*free)(struct sock_xinfo *);
 };

From f9771d8d71b1b98f6c30b5c631a2301f0315f440 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Fri, 4 Aug 2023 01:10:58 +0900
Subject: [PATCH 03/15] lsfd: fill ENDPOINTS column of unix socket using
 UNIX_DIAG_PEER information

An example output:

   # ./lsfd -Q '((PID == 1) || (PID == 1896)) && (TYPE == "UNIX-STREAM") && ((FD == 1) || (FD == 278))' -o+ENDPOINTS
   COMMAND        PID USER ASSOC  XMODE        TYPE SOURCE MNTID INODE NAME                                             ENDPOINTS
   systemd          1 root   278 rw---m UNIX-STREAM sockfs     9 37012 state=connected path=/run/systemd/journal/stdout 1896,ModemManager,1
   ModemManager  1896 root     1 rw---- UNIX-STREAM sockfs     9 43126 state=connected                                  1,systemd,278
                                                                                                                        1870458,systemd-journal,68

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd-sock-xinfo.c | 103 ++++++++++++++++++++++++++++++++++-
 1 file changed, 101 insertions(+), 2 deletions(-)

diff --git a/misc-utils/lsfd-sock-xinfo.c b/misc-utils/lsfd-sock-xinfo.c
index 3e7ff94eee4..301da278893 100644
--- a/misc-utils/lsfd-sock-xinfo.c
+++ b/misc-utils/lsfd-sock-xinfo.c
@@ -393,11 +393,18 @@ static void send_diag_request(int diagsd, void *req, size_t req_size,
 /*
  * UNIX
  */
+struct unix_ipc {
+	struct ipc ipc;
+	ino_t inode;
+	ino_t ipeer;
+};
+
 struct unix_xinfo {
 	struct sock_xinfo sock;
 	int acceptcon;	/* flags */
 	uint16_t type;
 	uint8_t  st;
+	struct unix_ipc *unix_ipc;
 	char path[
 		  UNIX_PATH_MAX
 		  + 1		/* for @ */
@@ -475,15 +482,76 @@ static bool unix_get_listening(struct sock_xinfo *sock_xinfo,
 	return ux->acceptcon;
 }
 
+static unsigned int unix_get_hash(struct file *file)
+{
+	return (unsigned int)(file->stat.st_ino % UINT_MAX);
+}
+
+static bool unix_is_suitable_ipc(struct ipc *ipc, struct file *file)
+{
+	return ((struct unix_ipc *)ipc)->inode == file->stat.st_ino;
+}
+
+/* For looking up an ipc struct for a sock inode, we need a sock strcuct
+ * for the inode. See the signature o get_ipc().
+ *
+ * However, there is a case that we have no sock strcuct for the inode;
+ * in the context we know only the sock inode.
+ * For the case, unix_make_dumy_sock() provides the way to make a
+ * dummy sock struct for the inode.
+ */
+static void unix_make_dumy_sock(struct sock *original, ino_t ino, struct sock *dummy)
+{
+	*dummy = *original;
+	dummy->file.stat.st_ino = ino;
+}
+
+static struct ipc_class unix_ipc_class = {
+	.size = sizeof(struct unix_ipc),
+	.get_hash = unix_get_hash,
+	.is_suitable_ipc = unix_is_suitable_ipc,
+	.free = NULL,
+};
+
+static struct ipc_class *unix_get_ipc_class(struct sock_xinfo *sock_xinfo __attribute__((__unused__)),
+					    struct sock *sock __attribute__((__unused__)))
+{
+	return &unix_ipc_class;
+}
+
+static inline char *unix_xstrendpoint(struct sock *sock)
+{
+	char *str = NULL;
+	xasprintf(&str, "%d,%s,%d",
+		  sock->file.proc->pid, sock->file.proc->command, sock->file.association);
+	return str;
+}
+
+static struct ipc *unix_get_peer_ipc(struct unix_xinfo *ux,
+				     struct sock *sock)
+{
+	struct unix_ipc *unix_ipc;
+	struct sock dummy_peer_sock;
+
+	unix_ipc = ux->unix_ipc;
+	if (!unix_ipc)
+		return NULL;
+
+	unix_make_dumy_sock(sock, unix_ipc->ipeer, &dummy_peer_sock);
+	return get_ipc(&dummy_peer_sock.file);
+}
+
 static bool unix_fill_column(struct proc *proc __attribute__((__unused__)),
 			     struct sock_xinfo *sock_xinfo,
-			     struct sock *sock __attribute__((__unused__)),
+			     struct sock *sock,
 			     struct libscols_line *ln __attribute__((__unused__)),
 			     int column_id,
 			     size_t column_index __attribute__((__unused__)),
 			     char **str)
 {
 	struct unix_xinfo *ux = (struct unix_xinfo *)sock_xinfo;
+	struct ipc *peer_ipc;
+	struct list_head *e;
 
 	switch (column_id) {
 	case COL_UNIX_PATH:
@@ -492,6 +560,24 @@ static bool unix_fill_column(struct proc *proc __attribute__((__unused__)),
 			return true;
 		}
 		break;
+	case COL_ENDPOINTS:
+		peer_ipc = unix_get_peer_ipc(ux, sock);
+		if (!peer_ipc)
+			break;
+
+		list_for_each_backwardly(e, &peer_ipc->endpoints) {
+			struct sock *peer_sock = list_entry(e, struct sock, endpoint.endpoints);
+			char *estr;
+
+			if (*str)
+				xstrputc(str, '\n');
+			estr = unix_xstrendpoint(peer_sock);
+			xstrappend(str, estr);
+			free(estr);
+		}
+		if (*str)
+			return true;
+		break;
 	}
 
 	return false;
@@ -503,6 +589,7 @@ static const struct sock_xinfo_class unix_xinfo_class = {
 	.get_state = unix_get_state,
 	.get_listening = unix_get_listening,
 	.fill_column = unix_fill_column,
+	.get_ipc_class = unix_get_ipc_class,
 	.free = NULL,
 };
 
@@ -588,6 +675,7 @@ static bool handle_diag_unix(ino_t netns __attribute__((__unused__)),
 	size_t rta_len;
 	ino_t inode;
 	struct sock_xinfo *xinfo;
+	struct unix_xinfo *unix_xinfo;
 
 	if (diag->udiag_family != AF_UNIX)
 		return false;
@@ -605,6 +693,7 @@ static bool handle_diag_unix(ino_t netns __attribute__((__unused__)),
 
 	if (xinfo->class != &unix_xinfo_class)
 		return true;
+	unix_xinfo = (struct unix_xinfo *)xinfo;
 
 	rta_len = nlmsg_len - NLMSG_LENGTH(sizeof(*diag));
 	for (struct rtattr *attr = (struct rtattr *)(diag + 1);
@@ -616,6 +705,16 @@ static bool handle_diag_unix(ino_t netns __attribute__((__unused__)),
 		case UNIX_DIAG_NAME:
 			unix_refill_name(xinfo, RTA_DATA(attr), len);
 			break;
+
+		case UNIX_DIAG_PEER:
+			if (len < 4)
+				break;
+
+			unix_xinfo->unix_ipc = (struct unix_ipc *)new_ipc(&unix_ipc_class);
+			unix_xinfo->unix_ipc->inode = inode;
+			unix_xinfo->unix_ipc->ipeer = (ino_t)(*(uint32_t *)RTA_DATA(attr));
+			add_ipc(&unix_xinfo->unix_ipc->ipc, inode % UINT_MAX);
+			break;
 		}
 	}
 	return true;
@@ -626,7 +725,7 @@ static void load_xinfo_from_diag_unix(int diagsd, ino_t netns)
 	struct unix_diag_req udr = {
 		.sdiag_family = AF_UNIX,
 		.udiag_states = -1, /* set the all bits. */
-		.udiag_show = UDIAG_SHOW_NAME,
+		.udiag_show = UDIAG_SHOW_NAME | UDIAG_SHOW_PEER,
 	};
 
 	send_diag_request(diagsd, &udr, sizeof(udr), handle_diag_unix, netns);

From 27c7778aeb70047e89a8028d19b5cf001db1a91f Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 21:07:02 +0900
Subject: [PATCH 04/15] lsfd: (man) document the ENDPOINT column for UNIX
 socket

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd.1.adoc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/misc-utils/lsfd.1.adoc b/misc-utils/lsfd.1.adoc
index 0aab4906f45..4149aabdf9f 100644
--- a/misc-utils/lsfd.1.adoc
+++ b/misc-utils/lsfd.1.adoc
@@ -188,6 +188,9 @@ write mode of the endpoint.
 eventfd type:::
 _PID_,_COMMAND_,_ASSOC_
 
+UNIX-STREAM:::
+_PID_,_COMMAND_,_ASSOC_
+
 EVENTFD.ID <``number``>::
 Eventfd ID.
 

From 98d1485de9c5fdc81d424e59eb7da47d21405555 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 9 Oct 2023 15:29:40 +0900
Subject: [PATCH 05/15] tests: (lsfd::mkfds-socketpair) make a case for testing
 DGRAM a subtest and add a subtest for STREAM

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 ...kfds-socketpair => mkfds-socketpair-DGRAM} |  0
 tests/expected/lsfd/mkfds-socketpair-STREAM   |  3 +++
 tests/ts/lsfd/mkfds-socketpair                | 22 +++++++++++++++++--
 3 files changed, 23 insertions(+), 2 deletions(-)
 rename tests/expected/lsfd/{mkfds-socketpair => mkfds-socketpair-DGRAM} (100%)
 create mode 100644 tests/expected/lsfd/mkfds-socketpair-STREAM

diff --git a/tests/expected/lsfd/mkfds-socketpair b/tests/expected/lsfd/mkfds-socketpair-DGRAM
similarity index 100%
rename from tests/expected/lsfd/mkfds-socketpair
rename to tests/expected/lsfd/mkfds-socketpair-DGRAM
diff --git a/tests/expected/lsfd/mkfds-socketpair-STREAM b/tests/expected/lsfd/mkfds-socketpair-STREAM
new file mode 100644
index 00000000000..d8ba4d0bc50
--- /dev/null
+++ b/tests/expected/lsfd/mkfds-socketpair-STREAM
@@ -0,0 +1,3 @@
+3 rw- SOCK sockfs UNIX
+4 rw- SOCK sockfs UNIX
+ASSOC,MODE,STTYPE,SOURCE,SOCK.PROTONAME: 0
diff --git a/tests/ts/lsfd/mkfds-socketpair b/tests/ts/lsfd/mkfds-socketpair
index 64984d94642..e8c9be0be53 100755
--- a/tests/ts/lsfd/mkfds-socketpair
+++ b/tests/ts/lsfd/mkfds-socketpair
@@ -33,6 +33,7 @@ FD0=3
 FD1=4
 EXPR=
 
+ts_init_subtest "DGRAM"
 {
     coproc MKFDS { "$TS_HELPER_MKFDS" socketpair $FD0 $FD1 socktype=DGRAM; }
     if read -u ${MKFDS[0]} PID; then
@@ -42,7 +43,24 @@ EXPR=
 
 	echo DONE >&"${MKFDS[1]}"
     fi
-    wait ${MKFDS_PID}
-} > $TS_OUTPUT 2>&1
+} > "$TS_OUTPUT" 2>&1
+
+wait ${MKFDS_PID}
+ts_finalize_subtest
+
+ts_init_subtest "STREAM"
+{
+    coproc MKFDS { "$TS_HELPER_MKFDS" socketpair $FD0 $FD1 socktype=STREAM; }
+    if read -u ${MKFDS[0]} PID; then
+	EXPR='(PID == '"${PID}"') and ((FD == '"$FD0"') or (FD == '"$FD1"'))'
+	${TS_CMD_LSFD} -n -o ASSOC,MODE,STTYPE,SOURCE,SOCK.PROTONAME -Q "${EXPR}" | sed -e 's/UNIX-STREAM/UNIX/'
+	echo 'ASSOC,MODE,STTYPE,SOURCE,SOCK.PROTONAME': ${PIPESTATUS[0]}
+
+	echo DONE >&"${MKFDS[1]}"
+    fi
+} > "$TS_OUTPUT" 2>&1
+
+wait ${MKFDS_PID}
+ts_finalize_subtest
 
 ts_finalize

From b3563457dbe009628a61e012a6accf7fcca803d2 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Fri, 4 Aug 2023 01:29:53 +0900
Subject: [PATCH 06/15] tests: (lsfd) add a case for testing ENDPOINTS column
 of UNIX-STREAM sockets

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 .../lsfd/mkfds-socketpair-STREAM-ENDPOINT     |  3 +++
 tests/ts/lsfd/mkfds-socketpair                | 24 +++++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT

diff --git a/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT b/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT
new file mode 100644
index 00000000000..ad015d8dec1
--- /dev/null
+++ b/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT
@@ -0,0 +1,3 @@
+3 rw- SOCK sockfs 1,test_mkfds,4
+4 rw- SOCK sockfs 1,test_mkfds,3
+ASSOC,MODE,STTYPE,SOURCE,ENDPOINTS: 0
diff --git a/tests/ts/lsfd/mkfds-socketpair b/tests/ts/lsfd/mkfds-socketpair
index e8c9be0be53..9883f0ac98b 100755
--- a/tests/ts/lsfd/mkfds-socketpair
+++ b/tests/ts/lsfd/mkfds-socketpair
@@ -63,4 +63,28 @@ ts_init_subtest "STREAM"
 wait ${MKFDS_PID}
 ts_finalize_subtest
 
+mkfds_socketpair_stream_endpoint()
+{
+    ts_init_subtest "STREAM-ENDPOINT"
+    if [ "$QEMU_USER" == "1" ]; then
+	ts_skip_subtest "running under qemu-user emulation"
+	return
+    fi
+    {
+	coproc MKFDS { "$TS_HELPER_MKFDS" socketpair $FD0 $FD1 socktype=STREAM; }
+	if read -u ${MKFDS[0]} PID; then
+	    EXPR='(FD == '"$FD0"') or (FD == '"$FD1"')'
+	    ${TS_CMD_LSFD} -p "${PID}" -n -o ASSOC,MODE,STTYPE,SOURCE,ENDPOINTS -Q "${EXPR}" | sed -e "s/${PID}/1/g"
+	    echo 'ASSOC,MODE,STTYPE,SOURCE,ENDPOINTS': ${PIPESTATUS[0]}
+
+	    echo DONE >&"${MKFDS[1]}"
+	fi
+    } > "$TS_OUTPUT" 2>&1
+
+    wait ${MKFDS_PID}
+    ts_finalize_subtest
+}
+
+mkfds_socketpair_stream_endpoint
+
 ts_finalize

From f4479119177f7453b46c6a2180d97f88c9cbe4af Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 23:00:41 +0900
Subject: [PATCH 07/15] lsfd: call xinfo backend method before calling socket
 generic method when filling columns

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd-sock.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/misc-utils/lsfd-sock.c b/misc-utils/lsfd-sock.c
index 7da2f61e589..ee0aa737a65 100644
--- a/misc-utils/lsfd-sock.c
+++ b/misc-utils/lsfd-sock.c
@@ -55,6 +55,15 @@ static bool sock_fill_column(struct proc *proc __attribute__((__unused__)),
 {
 	char *str = NULL;
 	struct sock *sock = (struct sock *)file;
+
+	if (sock->xinfo && sock->xinfo->class
+	    && sock->xinfo->class->fill_column) {
+		if (sock->xinfo->class->fill_column(proc, sock->xinfo, sock, ln,
+						    column_id, column_index,
+						    &str))
+			goto out;
+	}
+
 	switch(column_id) {
 	case COL_TYPE:
 		if (!sock->protoname)
@@ -112,16 +121,10 @@ static bool sock_fill_column(struct proc *proc __attribute__((__unused__)),
 			      : "0");
 		break;
 	default:
-		if (sock->xinfo && sock->xinfo->class
-		    && sock->xinfo->class->fill_column) {
-			if (sock->xinfo->class->fill_column(proc, sock->xinfo, sock, ln,
-							    column_id, column_index,
-							    &str))
-				break;
-		}
 		return false;
 	}
 
+ out:
 	if (!str)
 		err(EXIT_FAILURE, _("failed to add output data"));
 	if (scols_line_refer_data(ln, column_index, str))

From 426ff07f9a54503c5d8646a1589d4d7a7018d740 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 23:03:06 +0900
Subject: [PATCH 08/15] lsfd: add SOCK.SHUTDOWN column

An example output:

   # ./lsfd -p1 -Q '(TYPE == "UNIX-STREAM")' -o+SOCK.SHUTDOWN
   systemd   1 root   443 rw---m UNIX-STREAM sockfs     9 183103884 state=connected path=/run/systemd/journal/stdout r-
   systemd   1 root   462 rw---- UNIX-STREAM sockfs     9  11172039 state=listen path=/run/libvirt/libvirt-sock      rw

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd-sock-xinfo.c | 33 ++++++++++++++++++++++++++++++++-
 misc-utils/lsfd-sock.c       |  3 +++
 misc-utils/lsfd.c            |  3 +++
 misc-utils/lsfd.h            |  1 +
 4 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/misc-utils/lsfd-sock-xinfo.c b/misc-utils/lsfd-sock-xinfo.c
index 301da278893..a0e82026d77 100644
--- a/misc-utils/lsfd-sock-xinfo.c
+++ b/misc-utils/lsfd-sock-xinfo.c
@@ -404,6 +404,9 @@ struct unix_xinfo {
 	int acceptcon;	/* flags */
 	uint16_t type;
 	uint8_t  st;
+#define is_shutdown_mask_set(mask) ((mask) & (1 << 2))
+#define set_shutdown_mask(mask)    ((mask) |= (1 << 2))
+	uint8_t  shutdown_mask:3;
 	struct unix_ipc *unix_ipc;
 	char path[
 		  UNIX_PATH_MAX
@@ -519,6 +522,19 @@ static struct ipc_class *unix_get_ipc_class(struct sock_xinfo *sock_xinfo __attr
 	return &unix_ipc_class;
 }
 
+static bool unix_shutdown_chars(struct unix_xinfo *ux, char rw[2])
+{
+	uint8_t mask = ux->shutdown_mask;
+
+	if (is_shutdown_mask_set(mask)) {
+		rw[0] = ((mask & (1 << 0))? '-': 'r');
+		rw[1] = ((mask & (1 << 1))? '-': 'w');
+		return true;
+	}
+
+	return false;
+}
+
 static inline char *unix_xstrendpoint(struct sock *sock)
 {
 	char *str = NULL;
@@ -552,6 +568,7 @@ static bool unix_fill_column(struct proc *proc __attribute__((__unused__)),
 	struct unix_xinfo *ux = (struct unix_xinfo *)sock_xinfo;
 	struct ipc *peer_ipc;
 	struct list_head *e;
+	char shutdown_chars[3] = { 0 };
 
 	switch (column_id) {
 	case COL_UNIX_PATH:
@@ -578,6 +595,12 @@ static bool unix_fill_column(struct proc *proc __attribute__((__unused__)),
 		if (*str)
 			return true;
 		break;
+	case COL_SOCK_SHUTDOWN:
+		if (unix_shutdown_chars(ux, shutdown_chars)) {
+			*str = xstrdup(shutdown_chars);
+			return true;
+		}
+		break;
 	}
 
 	return false;
@@ -706,6 +729,14 @@ static bool handle_diag_unix(ino_t netns __attribute__((__unused__)),
 			unix_refill_name(xinfo, RTA_DATA(attr), len);
 			break;
 
+		case UNIX_DIAG_SHUTDOWN:
+			if (len < 1)
+				break;
+
+			unix_xinfo->shutdown_mask = *(uint8_t *)RTA_DATA(attr);
+			set_shutdown_mask(unix_xinfo->shutdown_mask);
+			break;
+
 		case UNIX_DIAG_PEER:
 			if (len < 4)
 				break;
@@ -725,7 +756,7 @@ static void load_xinfo_from_diag_unix(int diagsd, ino_t netns)
 	struct unix_diag_req udr = {
 		.sdiag_family = AF_UNIX,
 		.udiag_states = -1, /* set the all bits. */
-		.udiag_show = UDIAG_SHOW_NAME | UDIAG_SHOW_PEER,
+		.udiag_show = UDIAG_SHOW_NAME | UDIAG_SHOW_PEER | UNIX_DIAG_SHUTDOWN,
 	};
 
 	send_diag_request(diagsd, &udr, sizeof(udr), handle_diag_unix, netns);
diff --git a/misc-utils/lsfd-sock.c b/misc-utils/lsfd-sock.c
index ee0aa737a65..4c75e6eaf96 100644
--- a/misc-utils/lsfd-sock.c
+++ b/misc-utils/lsfd-sock.c
@@ -120,6 +120,9 @@ static bool sock_fill_column(struct proc *proc __attribute__((__unused__)),
 			      ? "1"
 			      : "0");
 		break;
+	case COL_SOCK_SHUTDOWN:
+		str = xstrdup("??");
+		break;
 	default:
 		return false;
 	}
diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index 13f6282c7e1..7bd24d26771 100644
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -296,6 +296,9 @@ static const struct colinfo infos[] = {
 	[COL_SOCK_PROTONAME]   = { "SOCK.PROTONAME",
 				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
 				   N_("protocol name") },
+	[COL_SOCK_SHUTDOWN]    = { "SOCK.SHUTDOWN",
+				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
+				   N_("shutdown state of socket ([-r?][-w?])") },
 	[COL_SOCK_STATE]       = { "SOCK.STATE",
 				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
 				   N_("State of socket") },
diff --git a/misc-utils/lsfd.h b/misc-utils/lsfd.h
index 9cf87f83085..c9c975392fc 100644
--- a/misc-utils/lsfd.h
+++ b/misc-utils/lsfd.h
@@ -99,6 +99,7 @@ enum {
 	COL_SOCK_LISTENING,
 	COL_SOCK_NETNS,
 	COL_SOCK_PROTONAME,
+	COL_SOCK_SHUTDOWN,
 	COL_SOCK_STATE,
 	COL_SOCK_TYPE,
 	COL_SOURCE,

From 0536fd829ad21d4d66ec03f2ca883125f306c6f9 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 23:15:59 +0900
Subject: [PATCH 09/15] lsfd: (man) write about SOCK.SHUTDOWN column

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd.1.adoc | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/misc-utils/lsfd.1.adoc b/misc-utils/lsfd.1.adoc
index 4149aabdf9f..02e34e7b574 100644
--- a/misc-utils/lsfd.1.adoc
+++ b/misc-utils/lsfd.1.adoc
@@ -423,6 +423,19 @@ Inode identifying network namespace where the socket belongs to.
 SOCK.PROTONAME <``string``>::
 Protocol name.
 
+SOCK.SHUTDOWN <``string``>::
+Shutdown state of socket.
++
+[-r?]:::
+If the first character is _r_, the receptions are allowed.
+If it is _-_, the receptions are disallowed.
+If it is _?_, the state is unknown.
++
+[-w?]:::
+If the second character is _w_, the transmissions are allowed.
+If it is _-_, the transmissions are disallowed.
+If it is _?_, the state is unknown.
+
 SOCK.STATE <``string``>::
 State of socket.
 

From cd30dd6f86bb0f9a82b618490a2853de8b2ad08a Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 23:19:51 +0900
Subject: [PATCH 10/15] lsfd: don't capitalize the help strings for the columns

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index 7bd24d26771..921216235d7 100644
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -301,10 +301,10 @@ static const struct colinfo infos[] = {
 				   N_("shutdown state of socket ([-r?][-w?])") },
 	[COL_SOCK_STATE]       = { "SOCK.STATE",
 				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
-				   N_("State of socket") },
+				   N_("state of socket") },
 	[COL_SOCK_TYPE]        = { "SOCK.TYPE",
 				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
-				   N_("Type of socket") },
+				   N_("type of socket") },
 	[COL_SOURCE]           = { "SOURCE",
 				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
 				   N_("file system, partition, or device containing file") },

From ef46aa41a12bc34480c305f7d30c8ce2e7fe9781 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 21:44:13 +0900
Subject: [PATCH 11/15] tests: (test_mkfds::socketpair) add "halfclose"
 parameter

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 tests/helpers/test_mkfds.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tests/helpers/test_mkfds.c b/tests/helpers/test_mkfds.c
index db61727e2c5..8a1388adff4 100644
--- a/tests/helpers/test_mkfds.c
+++ b/tests/helpers/test_mkfds.c
@@ -894,6 +894,12 @@ static void *make_socketpair(const struct factory *factory, struct fdesc fdescs[
 	int sd[2];
 	struct arg socktype = decode_arg("socktype", factory->params, argc, argv);
 	int isocktype;
+	struct arg halfclose = decode_arg("halfclose", factory->params, argc, argv);
+	bool bhalfclose;
+
+	bhalfclose = ARG_BOOLEAN(halfclose);
+	free_arg(&halfclose);
+
 	if (strcmp(ARG_STRING(socktype), "STREAM") == 0)
 		isocktype = SOCK_STREAM;
 	else if (strcmp(ARG_STRING(socktype), "DGRAM") == 0)
@@ -909,6 +915,15 @@ static void *make_socketpair(const struct factory *factory, struct fdesc fdescs[
 	if (socketpair(AF_UNIX, isocktype, 0, sd) < 0)
 		err(EXIT_FAILURE, "failed to make socket pair");
 
+	if (bhalfclose) {
+		if (shutdown(sd[0], SHUT_RD) < 0)
+			err(EXIT_FAILURE,
+			    "failed to shutdown the read end of the 1st socket");
+		if (shutdown(sd[1], SHUT_WR) < 0)
+			err(EXIT_FAILURE,
+			    "failed to shutdown the write end of the 2nd socket");
+	}
+
 	for (int i = 0; i < 2; i++) {
 		if (sd[i] != fdescs[i].fd) {
 			if (dup2(sd[i], fdescs[i].fd) < 0) {
@@ -3160,6 +3175,12 @@ static const struct factory factories[] = {
 				.desc = "STREAM, DGRAM, or SEQPACKET",
 				.defv.string = "STREAM",
 			},
+			{
+				.name = "halfclose",
+				.type = PTYPE_BOOLEAN,
+				.desc = "Shutdown the read end of the 1st socket, the write end of the 2nd socket",
+				.defv.boolean = false,
+			},
 			PARAM_END
 		},
 	},

From 750ad7ceb138c759f24adff7e823063df24414fe Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 23:35:46 +0900
Subject: [PATCH 12/15] tests: (lsfd) add a case for testing SOCK.SHUTDOWN
 column

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 .../mkfds-socketpair-STREAM-SHUTDOWN-STATE    |  3 +++
 tests/ts/lsfd/mkfds-socketpair                | 23 +++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 tests/expected/lsfd/mkfds-socketpair-STREAM-SHUTDOWN-STATE

diff --git a/tests/expected/lsfd/mkfds-socketpair-STREAM-SHUTDOWN-STATE b/tests/expected/lsfd/mkfds-socketpair-STREAM-SHUTDOWN-STATE
new file mode 100644
index 00000000000..a7a285ce469
--- /dev/null
+++ b/tests/expected/lsfd/mkfds-socketpair-STREAM-SHUTDOWN-STATE
@@ -0,0 +1,3 @@
+3 rw- SOCK sockfs -w
+4 rw- SOCK sockfs r-
+ASSOC,MODE,STTYPE,SOURCE,SOCK.SHUTDOWN: 0
diff --git a/tests/ts/lsfd/mkfds-socketpair b/tests/ts/lsfd/mkfds-socketpair
index 9883f0ac98b..ef354526bf4 100755
--- a/tests/ts/lsfd/mkfds-socketpair
+++ b/tests/ts/lsfd/mkfds-socketpair
@@ -85,6 +85,29 @@ mkfds_socketpair_stream_endpoint()
     ts_finalize_subtest
 }
 
+mkfds_socketpair_stream_shutdown_state()
+{
+    ts_init_subtest "STREAM-SHUTDOWN-STATE"
+    if [ "$QEMU_USER" == "1" ]; then
+	ts_skip_subtest "running under qemu-user emulation"
+	return
+    fi
+    {
+	coproc MKFDS { "$TS_HELPER_MKFDS" socketpair $FD0 $FD1 socktype=STREAM halfclose=1; }
+	if read -u ${MKFDS[0]} PID; then
+	    EXPR='(FD == '"$FD0"') or (FD == '"$FD1"')'
+	    ${TS_CMD_LSFD} -p "${PID}" -n -o ASSOC,MODE,STTYPE,SOURCE,SOCK.SHUTDOWN -Q "${EXPR}"
+	    echo 'ASSOC,MODE,STTYPE,SOURCE,SOCK.SHUTDOWN': ${PIPESTATUS[0]}
+
+	    echo DONE >&"${MKFDS[1]}"
+	fi
+    } > "$TS_OUTPUT" 2>&1
+
+    wait ${MKFDS_PID}
+    ts_finalize_subtest
+}
+
 mkfds_socketpair_stream_endpoint
+mkfds_socketpair_stream_shutdown_state
 
 ts_finalize

From 3f3da329201d3e30ca01de9d0b24132f7f9f36bc Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 23:50:21 +0900
Subject: [PATCH 13/15] lsfd: append SOCK.SHUTDOWN value to ENDPOINTS column of
 UNIX-STREAM sockets

An example output:

   # ./lsfd -Q '((PID == 1) || (PID == 1896)) && (TYPE == "UNIX-STREAM") && ((FD == 1) || (FD == 278))' -o+ENDPOINTS
   COMMAND        PID USER ASSOC  XMODE        TYPE SOURCE MNTID INODE NAME                                             ENDPOINTS
   systemd          1 root   278 rw---m UNIX-STREAM sockfs     9 37012 state=connected path=/run/systemd/journal/stdout 1896,ModemManager,1-w
   ModemManager  1896 root     1 rw---- UNIX-STREAM sockfs     9 43126 state=connected                                  1,systemd,278r-
                                                                                                                        1870458,systemd-journal,68r-

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd-sock-xinfo.c                         | 12 ++++++++++--
 tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT |  4 ++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/misc-utils/lsfd-sock-xinfo.c b/misc-utils/lsfd-sock-xinfo.c
index a0e82026d77..7ea8f2efe2b 100644
--- a/misc-utils/lsfd-sock-xinfo.c
+++ b/misc-utils/lsfd-sock-xinfo.c
@@ -538,8 +538,16 @@ static bool unix_shutdown_chars(struct unix_xinfo *ux, char rw[2])
 static inline char *unix_xstrendpoint(struct sock *sock)
 {
 	char *str = NULL;
-	xasprintf(&str, "%d,%s,%d",
-		  sock->file.proc->pid, sock->file.proc->command, sock->file.association);
+	char shutdown_chars[3] = { 0 };
+
+	if (!unix_shutdown_chars(((struct unix_xinfo *)sock->xinfo), shutdown_chars)) {
+		shutdown_chars[0] = '?';
+		shutdown_chars[1] = '?';
+	}
+	xasprintf(&str, "%d,%s,%d%c%c",
+		  sock->file.proc->pid, sock->file.proc->command, sock->file.association,
+		  shutdown_chars[0], shutdown_chars[1]);
+
 	return str;
 }
 
diff --git a/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT b/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT
index ad015d8dec1..02f6498a967 100644
--- a/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT
+++ b/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT
@@ -1,3 +1,3 @@
-3 rw- SOCK sockfs 1,test_mkfds,4
-4 rw- SOCK sockfs 1,test_mkfds,3
+3 rw- SOCK sockfs 1,test_mkfds,4rw
+4 rw- SOCK sockfs 1,test_mkfds,3rw
 ASSOC,MODE,STTYPE,SOURCE,ENDPOINTS: 0

From b0dbcec023e7108171c5b6f44556529c82bc1812 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 21:52:00 +0900
Subject: [PATCH 14/15] tests: (lsfd) extend the mkfds-socketpair case to test
 ENDPOINTS with SOCK.SHUTDOWN info

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 ...mkfds-socketpair-STREAM-ENDPOINT-halfclose |  3 +++
 tests/ts/lsfd/mkfds-socketpair                | 23 +++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT-halfclose

diff --git a/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT-halfclose b/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT-halfclose
new file mode 100644
index 00000000000..72fa0525767
--- /dev/null
+++ b/tests/expected/lsfd/mkfds-socketpair-STREAM-ENDPOINT-halfclose
@@ -0,0 +1,3 @@
+3 rw- SOCK sockfs 1,test_mkfds,4r-
+4 rw- SOCK sockfs 1,test_mkfds,3-w
+ASSOC,MODE,STTYPE,SOURCE,ENDPOINTS: 0
diff --git a/tests/ts/lsfd/mkfds-socketpair b/tests/ts/lsfd/mkfds-socketpair
index ef354526bf4..38f9279cebe 100755
--- a/tests/ts/lsfd/mkfds-socketpair
+++ b/tests/ts/lsfd/mkfds-socketpair
@@ -107,7 +107,30 @@ mkfds_socketpair_stream_shutdown_state()
     ts_finalize_subtest
 }
 
+mkfds_socketpair_stream_endpoint_halfclose()
+{
+    ts_init_subtest "STREAM-ENDPOINT-halfclose"
+    if [ "$QEMU_USER" == "1" ]; then
+	ts_skip_subtest "running under qemu-user emulation"
+	return
+    fi
+    {
+	coproc MKFDS { "$TS_HELPER_MKFDS" socketpair $FD0 $FD1 socktype=STREAM halfclose=1; }
+	if read -u ${MKFDS[0]} PID; then
+	    EXPR='(FD == '"$FD0"') or (FD == '"$FD1"')'
+	    ${TS_CMD_LSFD} -p "${PID}" -n -o ASSOC,MODE,STTYPE,SOURCE,ENDPOINTS -Q "${EXPR}" | sed -e "s/${PID}/1/g"
+	    echo 'ASSOC,MODE,STTYPE,SOURCE,ENDPOINTS': ${PIPESTATUS[0]}
+
+	    echo DONE >&"${MKFDS[1]}"
+	fi
+    } > "$TS_OUTPUT" 2>&1
+
+    wait ${MKFDS_PID}
+    ts_finalize_subtest
+}
+
 mkfds_socketpair_stream_endpoint
 mkfds_socketpair_stream_shutdown_state
+mkfds_socketpair_stream_endpoint_halfclose
 
 ts_finalize

From d58cd0f7eac2056ec80fdf9fae60887726d77b1f Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 2 Oct 2023 23:56:47 +0900
Subject: [PATCH 15/15] lsfd: (man) update the description of ENDPOINTS column
 of UNIX-Stream sockets

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 misc-utils/lsfd.1.adoc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/misc-utils/lsfd.1.adoc b/misc-utils/lsfd.1.adoc
index 02e34e7b574..1f7e889d46c 100644
--- a/misc-utils/lsfd.1.adoc
+++ b/misc-utils/lsfd.1.adoc
@@ -189,7 +189,10 @@ eventfd type:::
 _PID_,_COMMAND_,_ASSOC_
 
 UNIX-STREAM:::
-_PID_,_COMMAND_,_ASSOC_
+_PID_,_COMMAND_,_ASSOC_[-r?][-w?]
++
+About the last characters ([-r?][-w?]), see the description
+of _SOCK.SHUTDOWN_.
 
 EVENTFD.ID <``number``>::
 Eventfd ID.