--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <linux/audit.h>
+#include <linux/netlink.h>
+
+static int fd;
+
+#define MAX_AUDIT_MESSAGE_LENGTH 8970
+struct audit_message {
+ struct nlmsghdr nlh;
+ union {
+ struct audit_status s;
+ char data[MAX_AUDIT_MESSAGE_LENGTH];
+ } u;
+};
+
+int audit_recv(int fd, struct audit_message *rep)
+{
+ struct sockaddr_nl addr;
+ socklen_t addrlen = sizeof(addr);
+ int ret;
+
+ do {
+ ret = recvfrom(fd, rep, sizeof(*rep), 0,
+ (struct sockaddr *)&addr, &addrlen);
+ } while (ret < 0 && errno == EINTR);
+
+ if (ret < 0 ||
+ addrlen != sizeof(addr) ||
+ addr.nl_pid != 0 ||
+ rep->nlh.nlmsg_type == NLMSG_ERROR) /* short-cut for now */
+ return -1;
+
+ return ret;
+}
+
+int audit_send(int fd, uint16_t type, uint32_t key, uint32_t val)
+{
+ static int seq = 0;
+ struct audit_message msg = {
+ .nlh = {
+ .nlmsg_len = NLMSG_SPACE(sizeof(msg.u.s)),
+ .nlmsg_type = type,
+ .nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK,
+ .nlmsg_seq = ++seq,
+ },
+ .u.s = {
+ .mask = key,
+ .enabled = key == AUDIT_STATUS_ENABLED ? val : 0,
+ .pid = key == AUDIT_STATUS_PID ? val : 0,
+ }
+ };
+ struct sockaddr_nl addr = {
+ .nl_family = AF_NETLINK,
+ };
+ int ret;
+
+ do {
+ ret = sendto(fd, &msg, msg.nlh.nlmsg_len, 0,
+ (struct sockaddr *)&addr, sizeof(addr));
+ } while (ret < 0 && errno == EINTR);
+
+ if (ret != (int)msg.nlh.nlmsg_len)
+ return -1;
+ return 0;
+}
+
+int audit_set(int fd, uint32_t key, uint32_t val)
+{
+ struct audit_message rep = { 0 };
+ int ret;
+
+ ret = audit_send(fd, AUDIT_SET, key, val);
+ if (ret)
+ return ret;
+
+ ret = audit_recv(fd, &rep);
+ if (ret < 0)
+ return ret;
+ return 0;
+}
+
+int readlog(int fd)
+{
+ struct audit_message rep = { 0 };
+ int ret = audit_recv(fd, &rep);
+ const char *sep = "";
+ char *k, *v;
+
+ if (ret < 0)
+ return ret;
+
+ if (rep.nlh.nlmsg_type != AUDIT_NETFILTER_CFG)
+ return 0;
+
+ /* skip the initial "audit(...): " part */
+ strtok(rep.u.data, " ");
+
+ while ((k = strtok(NULL, "="))) {
+ v = strtok(NULL, " ");
+
+ /* these vary and/or are uninteresting, ignore */
+ if (!strcmp(k, "pid") ||
+ !strcmp(k, "comm") ||
+ !strcmp(k, "subj"))
+ continue;
+
+ /* strip the varying sequence number */
+ if (!strcmp(k, "table"))
+ *strchrnul(v, ':') = '\0';
+
+ printf("%s%s=%s", sep, k, v);
+ sep = " ";
+ }
+ if (*sep) {
+ printf("\n");
+ fflush(stdout);
+ }
+ return 0;
+}
+
+void cleanup(int sig)
+{
+ audit_set(fd, AUDIT_STATUS_ENABLED, 0);
+ close(fd);
+ if (sig)
+ exit(0);
+}
+
+int main(int argc, char **argv)
+{
+ struct sigaction act = {
+ .sa_handler = cleanup,
+ };
+
+ fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_AUDIT);
+ if (fd < 0) {
+ perror("Can't open netlink socket");
+ return -1;
+ }
+
+ if (sigaction(SIGTERM, &act, NULL) < 0 ||
+ sigaction(SIGINT, &act, NULL) < 0) {
+ perror("Can't set signal handler");
+ close(fd);
+ return -1;
+ }
+
+ audit_set(fd, AUDIT_STATUS_ENABLED, 1);
+ audit_set(fd, AUDIT_STATUS_PID, getpid());
+
+ while (1)
+ readlog(fd);
+}
--- /dev/null
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Check that audit logs generated for nft commands are as expected.
+
+SKIP_RC=4
+RC=0
+
+nft --version >/dev/null 2>&1 || {
+ echo "SKIP: missing nft tool"
+ exit $SKIP_RC
+}
+
+logfile=$(mktemp)
+echo "logging into $logfile"
+./audit_logread >"$logfile" &
+logread_pid=$!
+trap 'kill $logread_pid; rm -f $logfile' EXIT
+exec 3<"$logfile"
+
+do_test() { # (cmd, log)
+ echo -n "testing for cmd: $1 ... "
+ cat <&3 >/dev/null
+ $1 >/dev/null || exit 1
+ sleep 0.1
+ res=$(diff -a -u <(echo "$2") - <&3)
+ [ $? -eq 0 ] && { echo "OK"; return; }
+ echo "FAIL"
+ echo "$res"
+ ((RC++))
+}
+
+nft flush ruleset
+
+for table in t1 t2; do
+ do_test "nft add table $table" \
+ "table=$table family=2 entries=1 op=nft_register_table"
+
+ do_test "nft add chain $table c1" \
+ "table=$table family=2 entries=1 op=nft_register_chain"
+
+ do_test "nft add chain $table c2; add chain $table c3" \
+ "table=$table family=2 entries=2 op=nft_register_chain"
+
+ cmd="add rule $table c1 counter"
+
+ do_test "nft $cmd" \
+ "table=$table family=2 entries=1 op=nft_register_rule"
+
+ do_test "nft $cmd; $cmd" \
+ "table=$table family=2 entries=2 op=nft_register_rule"
+
+ cmd=""
+ sep=""
+ for chain in c2 c3; do
+ for i in {1..3}; do
+ cmd+="$sep add rule $table $chain counter"
+ sep=";"
+ done
+ done
+ do_test "nft $cmd" \
+ "table=$table family=2 entries=6 op=nft_register_rule"
+done
+
+do_test 'nft reset rules t1 c2' \
+'table=t1 family=2 entries=3 op=nft_reset_rule'
+
+do_test 'nft reset rules table t1' \
+'table=t1 family=2 entries=3 op=nft_reset_rule
+table=t1 family=2 entries=3 op=nft_reset_rule
+table=t1 family=2 entries=3 op=nft_reset_rule'
+
+do_test 'nft reset rules' \
+'table=t1 family=2 entries=3 op=nft_reset_rule
+table=t1 family=2 entries=3 op=nft_reset_rule
+table=t1 family=2 entries=3 op=nft_reset_rule
+table=t2 family=2 entries=3 op=nft_reset_rule
+table=t2 family=2 entries=3 op=nft_reset_rule
+table=t2 family=2 entries=3 op=nft_reset_rule'
+
+for ((i = 0; i < 500; i++)); do
+ echo "add rule t2 c3 counter accept comment \"rule $i\""
+done | do_test 'nft -f -' \
+'table=t2 family=2 entries=500 op=nft_register_rule'
+
+do_test 'nft reset rules t2 c3' \
+'table=t2 family=2 entries=189 op=nft_reset_rule
+table=t2 family=2 entries=188 op=nft_reset_rule
+table=t2 family=2 entries=126 op=nft_reset_rule'
+
+do_test 'nft reset rules t2' \
+'table=t2 family=2 entries=3 op=nft_reset_rule
+table=t2 family=2 entries=3 op=nft_reset_rule
+table=t2 family=2 entries=186 op=nft_reset_rule
+table=t2 family=2 entries=188 op=nft_reset_rule
+table=t2 family=2 entries=129 op=nft_reset_rule'
+
+do_test 'nft reset rules' \
+'table=t1 family=2 entries=3 op=nft_reset_rule
+table=t1 family=2 entries=3 op=nft_reset_rule
+table=t1 family=2 entries=3 op=nft_reset_rule
+table=t2 family=2 entries=3 op=nft_reset_rule
+table=t2 family=2 entries=3 op=nft_reset_rule
+table=t2 family=2 entries=180 op=nft_reset_rule
+table=t2 family=2 entries=188 op=nft_reset_rule
+table=t2 family=2 entries=135 op=nft_reset_rule'
+
+exit $RC