tests/py: Use libnftables instead of calling nft binary

This adds a simple nftables Python class in py/nftables.py which gives
access to libnftables API via ctypes module.

nft-test.py is extended to make use of the above class instead of
calling nft binary. Since command line formatting had to be touched
anyway, this patch also streamlines things a bit by introducing
__str__ methods to classes Table and Chain and making extensive use of
format strings instead of onerously adding all string parts together.

Since the called commands don't see a shell anymore, all shell meta
character escaping done in testcases is removed.

The visible effects of this change are:

* Four new warnings in ip/flowtable.t due to changing objref IDs (will
  be addressed later in a patch to libnftnl).

* Reported command line in warning and error messages changed slightly
  for obvious reasons.

* Reduction of a full test run's runtime by a factor of four. Status
  diff after running with 'time':

  < 83 test files, 77 files passed, 1724 unit tests, 0 error, 33 warning
  < 87.23user 696.13system 15:11.82elapsed 85%CPU (0avgtext+0avgdata 9604maxresident)k
  < 8inputs+36800outputs (0major+35171235minor)pagefaults 0swaps

  > 83 test files, 77 files passed, 1724 unit tests, 4 error, 33 warning
  > 6.80user 30.18system 3:45.86elapsed 16%CPU (0avgtext+0avgdata 14064maxresident)k
  > 0inputs+35808outputs (0major+2874minor)pagefaults 0swaps

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/tests/py/any/ct.t.payload b/tests/py/any/ct.t.payload
index 7ebf3f8d..9f288e79 100644
--- a/tests/py/any/ct.t.payload
+++ b/tests/py/any/ct.t.payload
@@ -343,31 +343,31 @@ ip test-ip4 output
   [ lookup reg 1 set __map%d dreg 1 ]
   [ ct set mark with reg 1 ]
 
-# ct original bytes \> 100000
+# ct original bytes > 100000
 ip test-ip4 output
   [ ct load bytes => reg 1 , dir original ]
   [ byteorder reg 1 = hton(reg 1, 8, 8) ]
   [ cmp gt reg 1 0x00000000 0xa0860100 ]
 
-# ct reply packets \< 100
+# ct reply packets < 100
 ip test-ip4 output
   [ ct load packets => reg 1 , dir reply ]
   [ byteorder reg 1 = hton(reg 1, 8, 8) ]
   [ cmp lt reg 1 0x00000000 0x64000000 ]
 
-# ct bytes \> 100000
+# ct bytes > 100000
 ip test-ip4 output
   [ ct load bytes => reg 1 ]
   [ byteorder reg 1 = hton(reg 1, 8, 8) ]
   [ cmp gt reg 1 0x00000000 0xa0860100 ]
 
-# ct avgpkt \> 200
+# ct avgpkt > 200
 ip test-ip4 output
   [ ct load avgpkt => reg 1 ]
   [ byteorder reg 1 = hton(reg 1, 8, 8) ]
   [ cmp gt reg 1 0x00000000 0xc8000000 ]
 
-# ct original avgpkt \< 500
+# ct original avgpkt < 500
 ip test-ip4 output
   [ ct load avgpkt => reg 1 , dir original ]
   [ byteorder reg 1 = hton(reg 1, 8, 8) ]
@@ -396,7 +396,7 @@ ip test-ip4 output
   [ immediate reg 1 0x00000001 ]
   [ ct set event with reg 1 ]
 
-# ct event set 'new | related | destroy | label'
+# ct event set new | related | destroy | label
 ip test-ip4 output
   [ immediate reg 1 0x00000407 ]
   [ ct set event with reg 1 ]