From 93e14b6d776e850a371fe4234a06088f210d8651 Mon Sep 17 00:00:00 2001 From: Masatake YAMATO Date: Wed, 29 Jan 2014 16:43:31 +0900 Subject: [PATCH] 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: mtu 1500 ... changelog: v2: indent iff just like the other fdinfo fields are. v3: remove unused variable. Both are suggested by David Miller . Signed-off-by: Masatake YAMATO Signed-off-by: David S. Miller --- drivers/net/tun.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index bcf01af4b879..44c4db8450f0 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -69,6 +69,7 @@ #include #include #include +#include #include @@ -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 = { -- 2.20.1