1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2 /* Copyright (c) 2018 Facebook */
8 #include <linux/rtnetlink.h>
9 #include <sys/socket.h>
15 #include "libbpf_internal.h"
19 #define SOL_NETLINK 270
22 typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
24 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
30 struct xdp_link_info info;
33 static int libbpf_netlink_open(__u32 *nl_pid)
35 struct sockaddr_nl sa;
40 memset(&sa, 0, sizeof(sa));
41 sa.nl_family = AF_NETLINK;
43 sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
47 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
48 &one, sizeof(one)) < 0) {
49 pr_warn("Netlink error reporting not supported\n");
52 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
58 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
63 if (addrlen != sizeof(sa)) {
64 ret = -LIBBPF_ERRNO__INTERNAL;
76 static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq,
77 __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
80 bool multipart = true;
88 len = recv(sock, buf, sizeof(buf), 0);
97 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
98 nh = NLMSG_NEXT(nh, len)) {
99 if (nh->nlmsg_pid != nl_pid) {
100 ret = -LIBBPF_ERRNO__WRNGPID;
103 if (nh->nlmsg_seq != seq) {
104 ret = -LIBBPF_ERRNO__INVSEQ;
107 if (nh->nlmsg_flags & NLM_F_MULTI)
109 switch (nh->nlmsg_type) {
111 err = (struct nlmsgerr *)NLMSG_DATA(nh);
115 libbpf_nla_dump_errormsg(nh);
123 ret = _fn(nh, fn, cookie);
134 static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd,
137 int sock, seq = 0, ret;
138 struct nlattr *nla, *nla_xdp;
141 struct ifinfomsg ifinfo;
146 sock = libbpf_netlink_open(&nl_pid);
150 memset(&req, 0, sizeof(req));
151 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
152 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
153 req.nh.nlmsg_type = RTM_SETLINK;
154 req.nh.nlmsg_pid = 0;
155 req.nh.nlmsg_seq = ++seq;
156 req.ifinfo.ifi_family = AF_UNSPEC;
157 req.ifinfo.ifi_index = ifindex;
159 /* started nested attribute for XDP */
160 nla = (struct nlattr *)(((char *)&req)
161 + NLMSG_ALIGN(req.nh.nlmsg_len));
162 nla->nla_type = NLA_F_NESTED | IFLA_XDP;
163 nla->nla_len = NLA_HDRLEN;
166 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
167 nla_xdp->nla_type = IFLA_XDP_FD;
168 nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
169 memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
170 nla->nla_len += nla_xdp->nla_len;
172 /* if user passed in any flags, add those too */
174 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
175 nla_xdp->nla_type = IFLA_XDP_FLAGS;
176 nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags);
177 memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags));
178 nla->nla_len += nla_xdp->nla_len;
181 if (flags & XDP_FLAGS_REPLACE) {
182 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
183 nla_xdp->nla_type = IFLA_XDP_EXPECTED_FD;
184 nla_xdp->nla_len = NLA_HDRLEN + sizeof(old_fd);
185 memcpy((char *)nla_xdp + NLA_HDRLEN, &old_fd, sizeof(old_fd));
186 nla->nla_len += nla_xdp->nla_len;
189 req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
191 if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
195 ret = bpf_netlink_recv(sock, nl_pid, seq, NULL, NULL, NULL);
202 int bpf_set_link_xdp_fd_opts(int ifindex, int fd, __u32 flags,
203 const struct bpf_xdp_set_link_opts *opts)
207 if (!OPTS_VALID(opts, bpf_xdp_set_link_opts))
210 if (OPTS_HAS(opts, old_fd)) {
211 old_fd = OPTS_GET(opts, old_fd, -1);
212 flags |= XDP_FLAGS_REPLACE;
215 return __bpf_set_link_xdp_fd_replace(ifindex, fd,
220 int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
222 return __bpf_set_link_xdp_fd_replace(ifindex, fd, 0, flags);
225 static int __dump_link_nlmsg(struct nlmsghdr *nlh,
226 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
228 struct nlattr *tb[IFLA_MAX + 1], *attr;
229 struct ifinfomsg *ifi = NLMSG_DATA(nlh);
232 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
233 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
234 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
235 return -LIBBPF_ERRNO__NLPARSE;
237 return dump_link_nlmsg(cookie, ifi, tb);
240 static int get_xdp_info(void *cookie, void *msg, struct nlattr **tb)
242 struct nlattr *xdp_tb[IFLA_XDP_MAX + 1];
243 struct xdp_id_md *xdp_id = cookie;
244 struct ifinfomsg *ifinfo = msg;
247 if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index)
253 ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL);
257 if (!xdp_tb[IFLA_XDP_ATTACHED])
260 xdp_id->info.attach_mode = libbpf_nla_getattr_u8(
261 xdp_tb[IFLA_XDP_ATTACHED]);
263 if (xdp_id->info.attach_mode == XDP_ATTACHED_NONE)
266 if (xdp_tb[IFLA_XDP_PROG_ID])
267 xdp_id->info.prog_id = libbpf_nla_getattr_u32(
268 xdp_tb[IFLA_XDP_PROG_ID]);
270 if (xdp_tb[IFLA_XDP_SKB_PROG_ID])
271 xdp_id->info.skb_prog_id = libbpf_nla_getattr_u32(
272 xdp_tb[IFLA_XDP_SKB_PROG_ID]);
274 if (xdp_tb[IFLA_XDP_DRV_PROG_ID])
275 xdp_id->info.drv_prog_id = libbpf_nla_getattr_u32(
276 xdp_tb[IFLA_XDP_DRV_PROG_ID]);
278 if (xdp_tb[IFLA_XDP_HW_PROG_ID])
279 xdp_id->info.hw_prog_id = libbpf_nla_getattr_u32(
280 xdp_tb[IFLA_XDP_HW_PROG_ID]);
285 static int libbpf_nl_get_link(int sock, unsigned int nl_pid,
286 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie);
288 int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
289 size_t info_size, __u32 flags)
291 struct xdp_id_md xdp_id = {};
296 if (flags & ~XDP_FLAGS_MASK || !info_size)
299 /* Check whether the single {HW,DRV,SKB} mode is set */
300 flags &= (XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE);
302 if (flags && flags & mask)
305 sock = libbpf_netlink_open(&nl_pid);
309 xdp_id.ifindex = ifindex;
310 xdp_id.flags = flags;
312 ret = libbpf_nl_get_link(sock, nl_pid, get_xdp_info, &xdp_id);
314 size_t sz = min(info_size, sizeof(xdp_id.info));
316 memcpy(info, &xdp_id.info, sz);
317 memset((void *) info + sz, 0, info_size - sz);
324 static __u32 get_xdp_id(struct xdp_link_info *info, __u32 flags)
326 flags &= XDP_FLAGS_MODES;
328 if (info->attach_mode != XDP_ATTACHED_MULTI && !flags)
329 return info->prog_id;
330 if (flags & XDP_FLAGS_DRV_MODE)
331 return info->drv_prog_id;
332 if (flags & XDP_FLAGS_HW_MODE)
333 return info->hw_prog_id;
334 if (flags & XDP_FLAGS_SKB_MODE)
335 return info->skb_prog_id;
340 int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags)
342 struct xdp_link_info info;
345 ret = bpf_get_link_xdp_info(ifindex, &info, sizeof(info), flags);
347 *prog_id = get_xdp_id(&info, flags);
352 int libbpf_nl_get_link(int sock, unsigned int nl_pid,
353 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
357 struct ifinfomsg ifm;
359 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
360 .nlh.nlmsg_type = RTM_GETLINK,
361 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
362 .ifm.ifi_family = AF_PACKET,
364 int seq = time(NULL);
366 req.nlh.nlmsg_seq = seq;
367 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
370 return bpf_netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
371 dump_link_nlmsg, cookie);