1 files changed, 116 insertions, 0 deletions
diff --git a/tools/testing/selftests/acct/netlink_helper.c b/tools/testing/selftests/acct/netlink_helper.c
new file mode 100644
index 000000000000..3ed834f0e770
--- /dev/null
+++ b/tools/testing/selftests/acct/netlink_helper.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <linux/genetlink.h>
+
+#include "netlink_helper.h"
+
+int netlink_open(void)
+{
+	struct timeval tv = { .tv_sec = ACCT_RCV_TIMEOUT_SEC };
+	struct sockaddr_nl addr = {
+		.nl_family = AF_NETLINK,
+		.nl_pid = getpid(),
+	};
+	int fd;
+
+	fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);
+	if (fd < 0)
+		return -errno;
+
+	if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) < 0) {
+		int err = -errno;
+
+		close(fd);
+		return err;
+	}
+
+	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+		int err = -errno;
+
+		close(fd);
+		return err;
+	}
+
+	return fd;
+}
+
+int send_request(int fd, void *buf, size_t len)
+{
+	struct sockaddr_nl addr = {
+		.nl_family = AF_NETLINK,
+	};
+
+	if (sendto(fd, buf, len, 0, (struct sockaddr *)&addr, sizeof(addr)) < 0)
+		return -errno;
+
+	return 0;
+}
+
+/*
+ * Resolve the generic netlink family ID for @name.
+ * Returns the family ID (>= 0) on success, negative errno on failure.
+ */
+int get_family_id(int fd, const char *name)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct genlmsghdr genl;
+		char buf[256];
+	} req = { 0 };
+	char resp[8192];
+	struct nlmsghdr *nlh;
+	struct genlmsghdr *genl;
+	struct nlattr *na;
+	int len;
+	int rem;
+	int ret;
+
+	req.nlh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
+	req.nlh.nlmsg_type = GENL_ID_CTRL;
+	req.nlh.nlmsg_flags = NLM_F_REQUEST;
+	req.nlh.nlmsg_seq = 1;
+	req.nlh.nlmsg_pid = getpid();
+
+	req.genl.cmd = CTRL_CMD_GETFAMILY;
+	req.genl.version = 1;
+
+	na = (struct nlattr *)((char *)&req + NLMSG_ALIGN(req.nlh.nlmsg_len));
+	na->nla_type = CTRL_ATTR_FAMILY_NAME;
+	na->nla_len = NLA_HDRLEN + strlen(name) + 1;
+	memcpy(nla_data(na), name, strlen(name) + 1);
+	req.nlh.nlmsg_len = NLMSG_ALIGN(req.nlh.nlmsg_len) + NLA_ALIGN(na->nla_len);
+
+	ret = send_request(fd, &req, req.nlh.nlmsg_len);
+	if (ret)
+		return ret;
+
+	len = recv(fd, resp, sizeof(resp), 0);
+	if (len < 0)
+		return -errno;
+
+	for (nlh = (struct nlmsghdr *)resp; NLMSG_OK(nlh, len);
+	     nlh = NLMSG_NEXT(nlh, len)) {
+		if (nlh->nlmsg_type == NLMSG_ERROR) {
+			struct nlmsgerr *err = NLMSG_DATA(nlh);
+
+			return err->error ? err->error : -ENOENT;
+		}
+
+		genl = (struct genlmsghdr *)NLMSG_DATA(nlh);
+		rem = nlh->nlmsg_len - NLMSG_HDRLEN - GENL_HDRLEN;
+		na = (struct nlattr *)((char *)genl + GENL_HDRLEN);
+		while (nla_ok(na, rem)) {
+			if (na->nla_type == CTRL_ATTR_FAMILY_ID)
+				return *(uint16_t *)nla_data(na);
+			na = nla_next(na, &rem);
+		}
+	}
+
+	return -ENOENT;
+}