From: Masatake YAMATO <yamato@redhat.com>
Date: Sun, 25 Jun 2023 17:41:33 +0000 (+0900)
Subject: lsfd: add TUN.IFFACE, a column for interfaces behind tun devices
X-Git-Tag: v2.40-rc1~352^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7cbec02a4768a9e2e49a0cf0c6e3c85e8bff9c14;p=thirdparty%2Futil-linux.git

lsfd: add TUN.IFFACE, a column for interfaces behind tun devices

An example output:

  # ./lsfd -Q '(SOURCE == "misc:tun")'  -o+TUN.IFACE
  COMMAND             PID       USER ASSOC MODE TYPE   SOURCE MNTID INODE NAME          TUN.IFACE
  qemu-system-x86 2846033       qemu    48  rw-  CHR misc:tun    23   306 iface=vnet89     vnet89
  qemu-system-x86 2865022       qemu    56  rw-  CHR misc:tun    23   306 iface=vnet103   vnet103
  openvpn         3113730 nm-openvpn     7  rw-  CHR misc:tun   588   306 iface=tun0         tun0
  qemu-system-x86 3608136       qemu    36  rw-  CHR misc:tun    23   306 iface=vnet104   vnet104
  qemu-system-x86 3608136       qemu    39  rw-  CHR misc:tun    23   306 iface=vnet105   vnet105
  qemu-system-x86 3608238       qemu    40  rw-  CHR misc:tun    23   306 iface=vnet106   vnet106
  qemu-system-x86 3608238       qemu    43  rw-  CHR misc:tun    23   306 iface=vnet107   vnet107
  qemu-system-x86 3608338       qemu    54  rw-  CHR misc:tun    23   306 iface=vnet108   vnet108
  qemu-system-x86 3608338       qemu    60  rw-  CHR misc:tun    23   306 iface=vnet109   vnet109

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---

diff --git a/misc-utils/lsfd-cdev.c b/misc-utils/lsfd-cdev.c
index 4b37b128ad..5f0f306500 100644
--- a/misc-utils/lsfd-cdev.c
+++ b/misc-utils/lsfd-cdev.c
@@ -255,7 +255,82 @@ static struct cdev_ops cdev_misc_ops = {
 	.fill_column = cdev_misc_fill_column,
 };
 
+/*
+ * tun devcie driver
+ */
+static bool cdev_tun_probe(const struct cdev *cdev)
+{
+	const char *miscdev;
+
+	if ((!cdev->devdrv) || strcmp(cdev->devdrv, "misc"))
+		return false;
+
+	miscdev = get_miscdev(minor(cdev->file.stat.st_rdev));
+	if (miscdev && strcmp(miscdev, "tun") == 0)
+		return true;
+	return false;
+}
+
+static void cdev_tun_free(const struct cdev *cdev)
+{
+	if (cdev->cdev_data)
+		free(cdev->cdev_data);
+}
+
+static char * cdev_tun_get_name(struct cdev *cdev)
+{
+	char *str = NULL;
+
+	if (cdev->cdev_data == NULL)
+		return NULL;
+
+	xasprintf(&str, "iface=%s", (const char *)cdev->cdev_data);
+	return str;
+}
+
+static bool cdev_tun_fill_column(struct proc *proc  __attribute__((__unused__)),
+				 struct cdev *cdev,
+				 struct libscols_line *ln __attribute__((__unused__)),
+				 int column_id,
+				 size_t column_index __attribute__((__unused__)),
+				 char **str)
+{
+	switch(column_id) {
+	case COL_MISCDEV:
+		*str = xstrdup("tun");
+		return true;
+	case COL_SOURCE:
+		*str = xstrdup("misc:tun");
+		return true;
+	case COL_TUN_IFACE:
+		if (cdev->cdev_data) {
+			*str = xstrdup(cdev->cdev_data);
+			return true;
+		}
+	}
+	return false;
+}
+
+static int cdev_tun_handle_fdinfo(struct cdev *cdev, const char *key, const char *val)
+{
+	if (strcmp(key, "iff") == 0 && cdev->cdev_data == NULL) {
+		cdev->cdev_data = xstrdup(val);
+		return 1;
+	}
+	return false;
+}
+
+static struct cdev_ops cdev_tun_ops = {
+	.parent = &cdev_misc_ops,
+	.probe = cdev_tun_probe,
+	.free  = cdev_tun_free,
+	.get_name = cdev_tun_get_name,
+	.fill_column = cdev_tun_fill_column,
+	.handle_fdinfo = cdev_tun_handle_fdinfo,
+};
+
 static const struct cdev_ops *cdev_ops[] = {
+	&cdev_tun_ops,
 	&cdev_misc_ops,
 	&cdev_generic_ops		  /* This must be at the end. */
 };
diff --git a/misc-utils/lsfd.1.adoc b/misc-utils/lsfd.1.adoc
index ee53cec499..8a78d8e233 100644
--- a/misc-utils/lsfd.1.adoc
+++ b/misc-utils/lsfd.1.adoc
@@ -247,6 +247,9 @@ id=_EVENTFD.ID_
 inotify:::
 inodes=_INOTIFY.INODES_
 +
+misc:tun:::
+iface=_TUN.IFACE_
++
 NETLINK:::
 protocol=_NETLINK.PROTOCOL_[ lport=_NETLINK.LPORT_[ group=_NETLINK.GROUPS_]]
 +
@@ -426,6 +429,9 @@ Interval.
 TIMERFD.REMAINING <``number``>::
 Remaining time.
 
+TUN.IFACE <``string``>::
+Network intrface behind the tun device.
+
 TYPE <``string``>::
 Cooked version of STTYPE. It is same as STTYPE with exceptions.
 For SOCK, print the value for SOCK.PROTONAME.
diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index 7672a026aa..520fe182c9 100644
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -312,6 +312,9 @@ static const struct colinfo infos[] = {
 	[COL_TIMERFD_REMAINING]= { "TIMERFD.REMAINING",
 				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_NUMBER,
 				   N_("remaining time") },
+	[COL_TUN_IFACE]        = { "TUN.IFACE",
+				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
+				   N_("network interface behind the tun device") },
 	[COL_TYPE]             = { "TYPE",
 				   0,   SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
 				   N_("file type (cooked)") },
diff --git a/misc-utils/lsfd.h b/misc-utils/lsfd.h
index 1b86b625b3..f2c4c0e973 100644
--- a/misc-utils/lsfd.h
+++ b/misc-utils/lsfd.h
@@ -101,6 +101,7 @@ enum {
 	COL_TIMERFD_CLOCKID,
 	COL_TIMERFD_INTERVAL,
 	COL_TIMERFD_REMAINING,
+	COL_TUN_IFACE,
 	COL_TYPE,
 	COL_UDP_LADDR,
 	COL_UDP_RADDR,