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-rw-r--r--tools/lib/bpf/netlink.c337
1 files changed, 337 insertions, 0 deletions
diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c
new file mode 100644
index 000000000000..0ce67aea8f3b
--- /dev/null
+++ b/tools/lib/bpf/netlink.c
@@ -0,0 +1,337 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* 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
+
+typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
+ void *cookie);
+
+int libbpf_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,
+ __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
+ void *cookie)
+{
+ bool multipart = true;
+ struct nlmsgerr *err;
+ struct nlmsghdr *nh;
+ char buf[4096];
+ int len, ret;
+
+ while (multipart) {
+ multipart = false;
+ len = recv(sock, buf, sizeof(buf), 0);
+ if (len < 0) {
+ ret = -errno;
+ goto done;
+ }
+
+ if (len == 0)
+ break;
+
+ 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;
+ }
+ if (nh->nlmsg_flags & NLM_F_MULTI)
+ multipart = true;
+ switch (nh->nlmsg_type) {
+ case NLMSG_ERROR:
+ err = (struct nlmsgerr *)NLMSG_DATA(nh);
+ if (!err->error)
+ continue;
+ ret = err->error;
+ libbpf_nla_dump_errormsg(nh);
+ goto done;
+ case NLMSG_DONE:
+ return 0;
+ default:
+ break;
+ }
+ if (_fn) {
+ ret = _fn(nh, fn, cookie);
+ if (ret)
+ return ret;
+ }
+ }
+ }
+ 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 = libbpf_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, NULL, NULL, NULL);
+
+cleanup:
+ close(sock);
+ return ret;
+}
+
+static int __dump_link_nlmsg(struct nlmsghdr *nlh,
+ libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
+{
+ struct nlattr *tb[IFLA_MAX + 1], *attr;
+ struct ifinfomsg *ifi = NLMSG_DATA(nlh);
+ int len;
+
+ len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
+ attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
+ if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
+ return -LIBBPF_ERRNO__NLPARSE;
+
+ return dump_link_nlmsg(cookie, ifi, tb);
+}
+
+int libbpf_nl_get_link(int sock, unsigned int nl_pid,
+ libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
+{
+ struct {
+ struct nlmsghdr nlh;
+ struct ifinfomsg ifm;
+ } req = {
+ .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+ .nlh.nlmsg_type = RTM_GETLINK,
+ .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+ .ifm.ifi_family = AF_PACKET,
+ };
+ int seq = time(NULL);
+
+ req.nlh.nlmsg_seq = seq;
+ if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
+ return -errno;
+
+ return bpf_netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
+ dump_link_nlmsg, cookie);
+}
+
+static int __dump_class_nlmsg(struct nlmsghdr *nlh,
+ libbpf_dump_nlmsg_t dump_class_nlmsg,
+ void *cookie)
+{
+ struct nlattr *tb[TCA_MAX + 1], *attr;
+ struct tcmsg *t = NLMSG_DATA(nlh);
+ int len;
+
+ len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
+ attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
+ if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
+ return -LIBBPF_ERRNO__NLPARSE;
+
+ return dump_class_nlmsg(cookie, t, tb);
+}
+
+int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
+ libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie)
+{
+ struct {
+ struct nlmsghdr nlh;
+ struct tcmsg t;
+ } req = {
+ .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
+ .nlh.nlmsg_type = RTM_GETTCLASS,
+ .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+ .t.tcm_family = AF_UNSPEC,
+ .t.tcm_ifindex = ifindex,
+ };
+ int seq = time(NULL);
+
+ req.nlh.nlmsg_seq = seq;
+ if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
+ return -errno;
+
+ return bpf_netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
+ dump_class_nlmsg, cookie);
+}
+
+static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
+ libbpf_dump_nlmsg_t dump_qdisc_nlmsg,
+ void *cookie)
+{
+ struct nlattr *tb[TCA_MAX + 1], *attr;
+ struct tcmsg *t = NLMSG_DATA(nlh);
+ int len;
+
+ len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
+ attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
+ if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
+ return -LIBBPF_ERRNO__NLPARSE;
+
+ return dump_qdisc_nlmsg(cookie, t, tb);
+}
+
+int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
+ libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
+{
+ struct {
+ struct nlmsghdr nlh;
+ struct tcmsg t;
+ } req = {
+ .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
+ .nlh.nlmsg_type = RTM_GETQDISC,
+ .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+ .t.tcm_family = AF_UNSPEC,
+ .t.tcm_ifindex = ifindex,
+ };
+ int seq = time(NULL);
+
+ req.nlh.nlmsg_seq = seq;
+ if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
+ return -errno;
+
+ return bpf_netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
+ dump_qdisc_nlmsg, cookie);
+}
+
+static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
+ libbpf_dump_nlmsg_t dump_filter_nlmsg,
+ void *cookie)
+{
+ struct nlattr *tb[TCA_MAX + 1], *attr;
+ struct tcmsg *t = NLMSG_DATA(nlh);
+ int len;
+
+ len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
+ attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
+ if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
+ return -LIBBPF_ERRNO__NLPARSE;
+
+ return dump_filter_nlmsg(cookie, t, tb);
+}
+
+int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
+ libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie)
+{
+ struct {
+ struct nlmsghdr nlh;
+ struct tcmsg t;
+ } req = {
+ .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
+ .nlh.nlmsg_type = RTM_GETTFILTER,
+ .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+ .t.tcm_family = AF_UNSPEC,
+ .t.tcm_ifindex = ifindex,
+ .t.tcm_parent = handle,
+ };
+ int seq = time(NULL);
+
+ req.nlh.nlmsg_seq = seq;
+ if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
+ return -errno;
+
+ return bpf_netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
+ dump_filter_nlmsg, cookie);
+}
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