1 files changed, 38 insertions, 4 deletions

diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c
index 431bd25c6cdb..312f887570b2 100644
--- a/tools/lib/bpf/netlink.c
+++ b/tools/lib/bpf/netlink.c
@@ -132,7 +132,8 @@ done:
 	return ret;
 }
 
-int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
+static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd,
+					 __u32 flags)
 {
 	int sock, seq = 0, ret;
 	struct nlattr *nla, *nla_xdp;
@@ -141,7 +142,7 @@ int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
 		struct ifinfomsg ifinfo;
 		char             attrbuf[64];
 	} req;
-	__u32 nl_pid;
+	__u32 nl_pid = 0;
 
 	sock = libbpf_netlink_open(&nl_pid);
 	if (sock < 0)
@@ -178,6 +179,14 @@ int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
 		nla->nla_len += nla_xdp->nla_len;
 	}
 
+	if (flags & XDP_FLAGS_REPLACE) {
+		nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
+		nla_xdp->nla_type = IFLA_XDP_EXPECTED_FD;
+		nla_xdp->nla_len = NLA_HDRLEN + sizeof(old_fd);
+		memcpy((char *)nla_xdp + NLA_HDRLEN, &old_fd, sizeof(old_fd));
+		nla->nla_len += nla_xdp->nla_len;
+	}
+
 	req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
 
 	if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
@@ -191,6 +200,29 @@ cleanup:
 	return ret;
 }
 
+int bpf_set_link_xdp_fd_opts(int ifindex, int fd, __u32 flags,
+			     const struct bpf_xdp_set_link_opts *opts)
+{
+	int old_fd = -1;
+
+	if (!OPTS_VALID(opts, bpf_xdp_set_link_opts))
+		return -EINVAL;
+
+	if (OPTS_HAS(opts, old_fd)) {
+		old_fd = OPTS_GET(opts, old_fd, -1);
+		flags |= XDP_FLAGS_REPLACE;
+	}
+
+	return __bpf_set_link_xdp_fd_replace(ifindex, fd,
+					     old_fd,
+					     flags);
+}
+
+int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
+{
+	return __bpf_set_link_xdp_fd_replace(ifindex, fd, 0, flags);
+}
+
 static int __dump_link_nlmsg(struct nlmsghdr *nlh,
 			     libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
 {
@@ -256,7 +288,7 @@ int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
 {
 	struct xdp_id_md xdp_id = {};
 	int sock, ret;
-	__u32 nl_pid;
+	__u32 nl_pid = 0;
 	__u32 mask;
 
 	if (flags & ~XDP_FLAGS_MASK || !info_size)
@@ -289,7 +321,9 @@ int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
 
 static __u32 get_xdp_id(struct xdp_link_info *info, __u32 flags)
 {
-	if (info->attach_mode != XDP_ATTACHED_MULTI)
+	flags &= XDP_FLAGS_MODES;
+
+	if (info->attach_mode != XDP_ATTACHED_MULTI && !flags)
 		return info->prog_id;
 	if (flags & XDP_FLAGS_DRV_MODE)
 		return info->drv_prog_id;