tools/bpf: move bpf/lib netlink related functions into a new file
There are no functionality change for this patch.
In the subsequent patches, more netlink related library functions
will be added and a separate file is better than cluttering bpf.c.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c
new file mode 100644
index 0000000..ccaa991
--- /dev/null
+++ b/tools/lib/bpf/netlink.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: LGPL-2.1
+/* Copyright (c) 2018 Facebook */
+
+#include <stdlib.h>
+#include <memory.h>
+#include <unistd.h>
+#include <linux/bpf.h>
+#include <linux/rtnetlink.h>
+#include <sys/socket.h>
+#include <errno.h>
+#include <time.h>
+
+#include "bpf.h"
+#include "libbpf.h"
+#include "nlattr.h"
+
+#ifndef SOL_NETLINK
+#define SOL_NETLINK 270
+#endif
+
+static int bpf_netlink_open(__u32 *nl_pid)
+{
+ struct sockaddr_nl sa;
+ socklen_t addrlen;
+ int one = 1, ret;
+ int sock;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.nl_family = AF_NETLINK;
+
+ sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+ if (sock < 0)
+ return -errno;
+
+ if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
+ &one, sizeof(one)) < 0) {
+ fprintf(stderr, "Netlink error reporting not supported\n");
+ }
+
+ if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
+ ret = -errno;
+ goto cleanup;
+ }
+
+ addrlen = sizeof(sa);
+ if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
+ ret = -errno;
+ goto cleanup;
+ }
+
+ if (addrlen != sizeof(sa)) {
+ ret = -LIBBPF_ERRNO__INTERNAL;
+ goto cleanup;
+ }
+
+ *nl_pid = sa.nl_pid;
+ return sock;
+
+cleanup:
+ close(sock);
+ return ret;
+}
+
+static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq)
+{
+ struct nlmsgerr *err;
+ struct nlmsghdr *nh;
+ char buf[4096];
+ int len, ret;
+
+ while (1) {
+ len = recv(sock, buf, sizeof(buf), 0);
+ if (len < 0) {
+ ret = -errno;
+ goto done;
+ }
+
+ for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
+ nh = NLMSG_NEXT(nh, len)) {
+ if (nh->nlmsg_pid != nl_pid) {
+ ret = -LIBBPF_ERRNO__WRNGPID;
+ goto done;
+ }
+ if (nh->nlmsg_seq != seq) {
+ ret = -LIBBPF_ERRNO__INVSEQ;
+ goto done;
+ }
+ switch (nh->nlmsg_type) {
+ case NLMSG_ERROR:
+ err = (struct nlmsgerr *)NLMSG_DATA(nh);
+ if (!err->error)
+ continue;
+ ret = err->error;
+ nla_dump_errormsg(nh);
+ goto done;
+ case NLMSG_DONE:
+ return 0;
+ default:
+ break;
+ }
+ }
+ }
+ ret = 0;
+done:
+ return ret;
+}
+
+int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
+{
+ int sock, seq = 0, ret;
+ struct nlattr *nla, *nla_xdp;
+ struct {
+ struct nlmsghdr nh;
+ struct ifinfomsg ifinfo;
+ char attrbuf[64];
+ } req;
+ __u32 nl_pid;
+
+ sock = bpf_netlink_open(&nl_pid);
+ if (sock < 0)
+ return sock;
+
+ memset(&req, 0, sizeof(req));
+ req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+ req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+ req.nh.nlmsg_type = RTM_SETLINK;
+ req.nh.nlmsg_pid = 0;
+ req.nh.nlmsg_seq = ++seq;
+ req.ifinfo.ifi_family = AF_UNSPEC;
+ req.ifinfo.ifi_index = ifindex;
+
+ /* started nested attribute for XDP */
+ nla = (struct nlattr *)(((char *)&req)
+ + NLMSG_ALIGN(req.nh.nlmsg_len));
+ nla->nla_type = NLA_F_NESTED | IFLA_XDP;
+ nla->nla_len = NLA_HDRLEN;
+
+ /* add XDP fd */
+ nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
+ nla_xdp->nla_type = IFLA_XDP_FD;
+ nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
+ memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
+ nla->nla_len += nla_xdp->nla_len;
+
+ /* if user passed in any flags, add those too */
+ if (flags) {
+ nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
+ nla_xdp->nla_type = IFLA_XDP_FLAGS;
+ nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags);
+ memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags));
+ 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) {
+ ret = -errno;
+ goto cleanup;
+ }
+ ret = bpf_netlink_recv(sock, nl_pid, seq);
+
+cleanup:
+ close(sock);
+ return ret;
+}