tests: shell: random interval set with size

Generate a random set with intervals to validate set size, try one that
should fit and then subtract one to set size and retry.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/tests/shell/testcases/sets/interval_size_random b/tests/shell/testcases/sets/interval_size_random
new file mode 100755 (executable)
index 0000000..701a1e7
--- /dev/null
+++ b/tests/shell/testcases/sets/interval_size_random
@@ -0,0 +1,113 @@
+#!/bin/bash
+
+generate_ip() {
+       local first=($1)
+       echo -n "$first.$((RANDOM % 256)).$((RANDOM % 256)).$((RANDOM % 256))"
+}
+
+ip_to_int() {
+       local IFS='.'
+       local ip=($1)
+       printf '%d' "$((${ip[0]}<<24 | ${ip[1]}<<16 | ${ip[2]}<<8 | ${ip[3]}))"
+}
+
+compare_ips() {
+       local ip1=$(ip_to_int $1)
+       local ip2=$(ip_to_int $2)
+       if [ "$ip1" -lt "$ip2" ]; then
+               echo "$1"
+       elif [ "$ip1" -gt "$ip2" ]; then
+               echo "$2"
+       else
+               echo "$1"
+       fi
+}
+
+generate_range() {
+       start=$(generate_ip $1)
+       end=$(generate_ip $1)
+       result=$(compare_ips $start $end)
+       if [[ "$result" != "$start" ]]
+       then
+               temp=$start
+               start=$end
+               end=$temp
+       fi
+       echo -n "$start-$end"
+}
+
+generate_prefix() {
+       prefix=$(generate_ip $1 | cut -d. -f1-3)
+       echo -n "$prefix.0/24"
+}
+
+generate_intervals() {
+       echo "define x = {"
+       # not so random, first octet in IP address is $i, this cannot go over 255
+       iter=$((RANDOM % 255 + 1))
+
+       [ $(($RANDOM % 2)) -eq 0 ] && echo "0.0.0.0,"
+
+       for ((i=0; i<iter; i++)); do
+               case $((RANDOM % 3)) in
+               0) generate_ip $i;;
+               1) generate_range $i;;
+               2) generate_prefix $i;;
+               esac
+               echo ","
+       done
+
+       [ $(($RANDOM % 2)) -eq 0 ] && echo "255.255.255.255,"
+
+       echo "}"
+}
+
+run_test() {
+       local count=($1)
+       local elems=($2)
+       local ruleset=($3)
+       echo "table inet x {
+       set y {
+               include \"$elems\"
+               typeof ip saddr
+               flags interval
+               size $count
+               elements = { \$x }
+       }
+      }" > $ruleset
+}
+
+count_elems() {
+       local elems=($2)
+       count=$(wc -l $elems_file | cut -f1 -d' ')
+       # subtract enclosing define lines
+       count=$(($count-2))
+       echo $count
+}
+
+elems_file=$(mktemp /tmp/elems-XXXXX.nft)
+ruleset_file=$(mktemp /tmp/ruleset-XXXXX.nft)
+
+if [ ! -w "$elems_file" ] ; then
+       # cwd might be readonly, mark as skip.
+       echo "Failed to create tmp file" >&2
+       exit 77
+fi
+
+trap "rm -rf $elems_file $ruleset_file" EXIT
+
+generate_intervals > $elems_file
+count=$(count_elems $elems_file)
+
+run_test $count $elems_file $ruleset_file
+$NFT -f $ruleset_file || exit 1
+
+$NFT flush ruleset
+
+# subtract 1 to size, too small, it should fail
+count=$(($count-1))
+
+run_test $count $elems_file $ruleset_file
+$NFT -f $ruleset_file && exit 1
+
+exit 0