[PATCH iproute2-next v2 0/6] ip: Use netlink to walk through network device list

[Serhey Popovych <serhe.popovych@gmail.com>]

In this seris I replace /proc/net/dev and /sys/class/net usage for walk
through network device list in iptunnel/ip6tunnel and iptuntap with
netlink dump.

Following changed since RFC was sent:

  1) Treat @struct rtnl_link_stats and @struct rtnl_link_stats64 as
     array with __u32 and __u64 elements respectively in
     copy_rtnl_link_stats64() as suggested by Stephen Hemminger.

  2) Remove @name and @size parameters from @struct tnl_print_nlmsg_info
     since we can get them easily from other data.

Testing.
========

Following script is used to ensure I didn't broke things too much:

\#!/bin/bash

iproute2_dir="$1"
iface='gre1'

pushd "$iproute2_dir" &>/dev/null

for i in new old; do
	DIR="/tmp/$i"
	mkdir -p "$DIR"

	ln -snf ip.$i ip/ip

	for o in '' -s -d; do
		ip/ip $o tunnel show           >"$DIR/ip${o}-tunnel-show"
		ip/ip -4 $o tunnel show        >"$DIR/ip-4${o}-tunnel-show"
		ip/ip -6 $o tunnel show        >"$DIR/ip-6${o}-tunnel-show"
		ip/ip $o tunnel show dev "$iface" \
			>"$DIR/ip${o}-tunnel-show-$iface"
		ip/ip $o tuntap show           >"$DIR/ip${o}-tuntap-show"
	done
done
rm -f ip/ip

diff -urN /tmp/{old,new} |sed -n -Ee'/^(-{3}|\+{3})[[:space:]]+/!p'
rc=$?

popd &>/dev/null
exit $rc

Results:
========

...
fopen /sys/class/net/ipip1/tun_flags: No such file or directory
fopen /sys/class/net/ipip2/tun_flags: No such file or directory
fopen /sys/class/net/gre10/tun_flags: No such file or directory
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note that this comes from ip.old
...
diff -urN /tmp/old/ip-d-tuntap-show /tmp/new/ip-d-tuntap-show
@@ -1,4 +1,4 @@
-tun1: tap user 1004 group 27
-	Attached to processes:
 tun0: tun user 1000 group 27
 	Attached to processes:
+tun1: tap user 1004 group 27
+	Attached to processes:
diff -urN /tmp/old/ip-s-tuntap-show /tmp/new/ip-s-tuntap-show
@@ -1,2 +1,2 @@
-tun1: tap user 1004 group 27
 tun0: tun user 1000 group 27
+tun1: tap user 1004 group 27
diff -urN /tmp/old/ip-tuntap-show /tmp/new/ip-tuntap-show
@@ -1,2 +1,2 @@
-tun1: tap user 1004 group 27
 tun0: tun user 1000 group 27
+tun1: tap user 1004 group 27

So basically only print order for ip tuntap get changes. Rest is intact.

v2
  Fix build failure in 0/4 patch ("iptunnel/ip6tunnel: Code cleanups")
  and update it's description showing why this cleanup is necessary.

  Update cover letter to explain origins of fopen /sys/class/net/...
  error message sources.

Thanks,
Serhii

Serhey Popovych (6):
  ipaddress: Unify print_link_stats() and print_link_stats64()
  ip: Introduce get_rtnl_link_stats_rta() to get link statistics
  tunnel: Split statistic getting and printing
  iptunnel/ip6tunnel: Code cleanups
  iptunnel/ip6tunnel: Use netlink to walk through tunnels list
  tuntap: Use netlink to walk through tuntap list

 include/utils.h |    3 +
 ip/ip6tunnel.c  |  115 +++++++++++----------------------
 ip/ipaddress.c  |  189 ++++---------------------------------------------------
 ip/iptunnel.c   |   93 +++++++++------------------
 ip/iptuntap.c   |  121 ++++++++++++++++++++++++++---------
 ip/tunnel.c     |  114 ++++++++++++++++++++++++++-------
 ip/tunnel.h     |   17 ++++-
 lib/utils.c     |   45 +++++++++++++
 8 files changed, 324 insertions(+), 373 deletions(-)

-- 
1.7.10.4