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authorMasatake YAMATO <yamato@redhat.com>2014-01-29 16:43:31 +0900
committerDavid S. Miller <davem@davemloft.net>2014-01-28 23:46:56 -0800
commit93e14b6d776e850a371fe4234a06088f210d8651 (patch)
tree18422336d2b25bc595dfea498d553e0d71ae3130 /drivers/net/tun.c
parent52efcea59eeae9f850e544c41764954273b0912c (diff)
tun: add device name(iff) field to proc fdinfo entry
A file descriptor opened for /dev/net/tun and a tun device are connected with ioctl. Though understanding the connection is important for trouble shooting, no way is given to a user to know the connected device for a given file descriptor at userland. This patch adds a new fdinfo field for the device name connected to a file descriptor opened for /dev/net/tun. Here is an example of the field: # lsof | grep tun qemu-syst 4565 qemu 25u CHR 10,200 0t138 12921 /dev/net/tun ... # cat /proc/4565/fdinfo/25 pos: 138 flags: 0104002 iff: vnet0 # ip link show dev vnet0 8: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 ... changelog: v2: indent iff just like the other fdinfo fields are. v3: remove unused variable. Both are suggested by David Miller <davem@davemloft.net>. Signed-off-by: Masatake YAMATO <yamato@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c27
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index bcf01af4b87..44c4db8450f 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -69,6 +69,7 @@
#include <net/netns/generic.h>
#include <net/rtnetlink.h>
#include <net/sock.h>
+#include <linux/seq_file.h>
#include <asm/uaccess.h>
@@ -2228,6 +2229,27 @@ static int tun_chr_close(struct inode *inode, struct file *file)
return 0;
}
+#ifdef CONFIG_PROC_FS
+static int tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
+{
+ struct tun_struct *tun;
+ struct ifreq ifr;
+
+ memset(&ifr, 0, sizeof(ifr));
+
+ rtnl_lock();
+ tun = tun_get(f);
+ if (tun)
+ tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
+ rtnl_unlock();
+
+ if (tun)
+ tun_put(tun);
+
+ return seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
+}
+#endif
+
static const struct file_operations tun_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
@@ -2242,7 +2264,10 @@ static const struct file_operations tun_fops = {
#endif
.open = tun_chr_open,
.release = tun_chr_close,
- .fasync = tun_chr_fasync
+ .fasync = tun_chr_fasync,
+#ifdef CONFIG_PROC_FS
+ .show_fdinfo = tun_chr_show_fdinfo,
+#endif
};
static struct miscdevice tun_miscdev = {