Support 'nft -f -' to read from stdin

In libnftables, detect if given filename is '-' and treat it as the
common way of requesting to read from stdin, then open /dev/stdin
instead. (Calling 'nft -f /dev/stdin' worked before as well, but this
makes it official.)

With this in place and bash's support for here strings, review all tests
in tests/shell for needless use of temp files. Note that two categories
of test cases were intentionally left unchanged:

- Tests creating potentially large rulesets to avoid running into shell
  parameter length limits.
- Tests for 'include' directive for obvious reasons.

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

1 files changed, 3 insertions, 11 deletions

diff --git a/tests/shell/testcases/sets/0001named_interval_0 b/tests/shell/testcases/sets/0001named_interval_0
index 8d08b755..74098125 100755
--- a/tests/shell/testcases/sets/0001named_interval_0
+++ b/tests/shell/testcases/sets/0001named_interval_0
@@ -4,15 +4,7 @@
 # * creating a valid interval set
 # * referencing it from a valid rule
 
-tmpfile=$(mktemp)
-if [ ! -w $tmpfile ] ; then
-	echo "Failed to create tmp file" >&2
-	exit 0
-fi
-
-trap "rm -rf $tmpfile" EXIT # cleanup if aborted
-
-echo "
+RULESET="
 table inet t {
 	set s1 {
 		type ipv4_addr
@@ -41,7 +33,7 @@ table inet t {
 		ip6 nexthdr @s3 accept
 		tcp dport @s4 accept
 	}
-}" > $tmpfile
+}"
 
 set -e
-$NFT -f $tmpfile
+$NFT -f - <<< $RULESET