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| author | Masatake YAMATO <yamato@redhat.com> | 2014-01-29 08:43:31 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-01-29 08:46:56 +0100 |
| commit | 93e14b6d776e850a371fe4234a06088f210d8651 (patch) | |
| tree | 18422336d2b25bc595dfea498d553e0d71ae3130 | |
| parent | Merge branch 'DT' (diff) | |
| download | linux-93e14b6d776e850a371fe4234a06088f210d8651.tar.xz linux-93e14b6d776e850a371fe4234a06088f210d8651.zip | |
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>
| -rw-r--r-- | drivers/net/tun.c | 27 |
1 files changed, 26 insertions, 1 deletions
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 <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 = { |