diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0401f40973a5..975c9a6ffb4a 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4267,6 +4267,7 @@ static void skb_ts_finish(struct ts_config *conf, struct ts_state *state) unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, unsigned int to, struct ts_config *config) { + unsigned int patlen = config->ops->get_pattern_len(config); struct ts_state state; unsigned int ret; @@ -4278,7 +4279,7 @@ unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, skb_prepare_seq_read(skb, from, to, TS_SKB_CB(&state)); ret = textsearch_find(config, &state); - return (ret <= to - from ? ret : UINT_MAX); + return (ret + patlen <= to - from ? ret : UINT_MAX); } EXPORT_SYMBOL(skb_find_text); diff --git a/tools/testing/selftests/netfilter/Makefile b/tools/testing/selftests/netfilter/Makefile index ef90aca4cc96..bced422b78f7 100644 --- a/tools/testing/selftests/netfilter/Makefile +++ b/tools/testing/selftests/netfilter/Makefile @@ -7,7 +7,7 @@ TEST_PROGS := nft_trans_stress.sh nft_fib.sh nft_nat.sh bridge_brouter.sh \ nft_queue.sh nft_meta.sh nf_nat_edemux.sh \ ipip-conntrack-mtu.sh conntrack_tcp_unreplied.sh \ conntrack_vrf.sh nft_synproxy.sh rpath.sh nft_audit.sh \ - conntrack_sctp_collision.sh + conntrack_sctp_collision.sh xt_string.sh HOSTPKG_CONFIG := pkg-config diff --git a/tools/testing/selftests/netfilter/xt_string.sh b/tools/testing/selftests/netfilter/xt_string.sh new file mode 100755 index 000000000000..1802653a4728 --- /dev/null +++ b/tools/testing/selftests/netfilter/xt_string.sh @@ -0,0 +1,128 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +# return code to signal skipped test +ksft_skip=4 +rc=0 + +if ! iptables --version >/dev/null 2>&1; then + echo "SKIP: Test needs iptables" + exit $ksft_skip +fi +if ! ip -V >/dev/null 2>&1; then + echo "SKIP: Test needs iproute2" + exit $ksft_skip +fi +if ! nc -h >/dev/null 2>&1; then + echo "SKIP: Test needs netcat" + exit $ksft_skip +fi + +pattern="foo bar baz" +patlen=11 +hdrlen=$((20 + 8)) # IPv4 + UDP +ns="ns-$(mktemp -u XXXXXXXX)" +trap 'ip netns del $ns' EXIT +ip netns add "$ns" +ip -net "$ns" link add d0 type dummy +ip -net "$ns" link set d0 up +ip -net "$ns" addr add 10.1.2.1/24 dev d0 + +#ip netns exec "$ns" tcpdump -npXi d0 & +#tcpdump_pid=$! +#trap 'kill $tcpdump_pid; ip netns del $ns' EXIT + +add_rule() { # (alg, from, to) + ip netns exec "$ns" \ + iptables -A OUTPUT -o d0 -m string \ + --string "$pattern" --algo $1 --from $2 --to $3 +} +showrules() { # () + ip netns exec "$ns" iptables -v -S OUTPUT | grep '^-A' +} +zerorules() { + ip netns exec "$ns" iptables -Z OUTPUT +} +countrule() { # (pattern) + showrules | grep -c -- "$*" +} +send() { # (offset) + ( for ((i = 0; i < $1 - $hdrlen; i++)); do + printf " " + done + printf "$pattern" + ) | ip netns exec "$ns" nc -w 1 -u 10.1.2.2 27374 +} + +add_rule bm 1000 1500 +add_rule bm 1400 1600 +add_rule kmp 1000 1500 +add_rule kmp 1400 1600 + +zerorules +send 0 +send $((1000 - $patlen)) +if [ $(countrule -c 0 0) -ne 4 ]; then + echo "FAIL: rules match data before --from" + showrules + ((rc--)) +fi + +zerorules +send 1000 +send $((1400 - $patlen)) +if [ $(countrule -c 2) -ne 2 ]; then + echo "FAIL: only two rules should match at low offset" + showrules + ((rc--)) +fi + +zerorules +send $((1500 - $patlen)) +if [ $(countrule -c 1) -ne 4 ]; then + echo "FAIL: all rules should match at end of packet" + showrules + ((rc--)) +fi + +zerorules +send 1495 +if [ $(countrule -c 1) -ne 1 ]; then + echo "FAIL: only kmp with proper --to should match pattern spanning fragments" + showrules + ((rc--)) +fi + +zerorules +send 1500 +if [ $(countrule -c 1) -ne 2 ]; then + echo "FAIL: two rules should match pattern at start of second fragment" + showrules + ((rc--)) +fi + +zerorules +send $((1600 - $patlen)) +if [ $(countrule -c 1) -ne 2 ]; then + echo "FAIL: two rules should match pattern at end of largest --to" + showrules + ((rc--)) +fi + +zerorules +send $((1600 - $patlen + 1)) +if [ $(countrule -c 1) -ne 0 ]; then + echo "FAIL: no rules should match pattern extending largest --to" + showrules + ((rc--)) +fi + +zerorules +send 1600 +if [ $(countrule -c 1) -ne 0 ]; then + echo "FAIL: no rule should match pattern past largest --to" + showrules + ((rc--)) +fi + +exit $rc