From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masatake YAMATO Subject: [PATCH v2] tun: add device name(iff) field to proc fdinfo entry Date: Wed, 29 Jan 2014 14:33:34 +0900 Message-ID: <1390973614-3929-1-git-send-email-yamato@redhat.com> References: <20140128.180819.623844973390653379.davem@davemloft.net> Cc: netdev@vger.kernel.org, yamato@redhat.com To: davem@davemloft.net Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57482 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750929AbaA2Fdv (ORCPT ); Wed, 29 Jan 2014 00:33:51 -0500 In-Reply-To: <20140128.180819.623844973390653379.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: 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. Suggested by David Miller . Signed-off-by: Masatake YAMATO --- drivers/net/tun.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index bcf01af..8651c31 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -69,6 +69,7 @@ #include #include #include +#include #include @@ -2228,6 +2229,28 @@ 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; + int ret; + + 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 +2265,10 @@ 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 = { -- 1.8.5.3