923 lines · c
1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)2/* Copyright (c) 2018 Facebook */3 4#include <stdlib.h>5#include <memory.h>6#include <unistd.h>7#include <arpa/inet.h>8#include <linux/bpf.h>9#include <linux/if_ether.h>10#include <linux/pkt_cls.h>11#include <linux/rtnetlink.h>12#include <linux/netdev.h>13#include <sys/socket.h>14#include <errno.h>15#include <time.h>16 17#include "bpf.h"18#include "libbpf.h"19#include "libbpf_internal.h"20#include "nlattr.h"21 22#ifndef SOL_NETLINK23#define SOL_NETLINK 27024#endif25 26typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);27 28typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,29 void *cookie);30 31struct xdp_link_info {32 __u32 prog_id;33 __u32 drv_prog_id;34 __u32 hw_prog_id;35 __u32 skb_prog_id;36 __u8 attach_mode;37};38 39struct xdp_id_md {40 int ifindex;41 __u32 flags;42 struct xdp_link_info info;43 __u64 feature_flags;44};45 46struct xdp_features_md {47 int ifindex;48 __u32 xdp_zc_max_segs;49 __u64 flags;50};51 52static int libbpf_netlink_open(__u32 *nl_pid, int proto)53{54 struct sockaddr_nl sa;55 socklen_t addrlen;56 int one = 1, ret;57 int sock;58 59 memset(&sa, 0, sizeof(sa));60 sa.nl_family = AF_NETLINK;61 62 sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, proto);63 if (sock < 0)64 return -errno;65 66 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,67 &one, sizeof(one)) < 0) {68 pr_warn("Netlink error reporting not supported\n");69 }70 71 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {72 ret = -errno;73 goto cleanup;74 }75 76 addrlen = sizeof(sa);77 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {78 ret = -errno;79 goto cleanup;80 }81 82 if (addrlen != sizeof(sa)) {83 ret = -LIBBPF_ERRNO__INTERNAL;84 goto cleanup;85 }86 87 *nl_pid = sa.nl_pid;88 return sock;89 90cleanup:91 close(sock);92 return ret;93}94 95static void libbpf_netlink_close(int sock)96{97 close(sock);98}99 100enum {101 NL_CONT,102 NL_NEXT,103 NL_DONE,104};105 106static int netlink_recvmsg(int sock, struct msghdr *mhdr, int flags)107{108 int len;109 110 do {111 len = recvmsg(sock, mhdr, flags);112 } while (len < 0 && (errno == EINTR || errno == EAGAIN));113 114 if (len < 0)115 return -errno;116 return len;117}118 119static int alloc_iov(struct iovec *iov, int len)120{121 void *nbuf;122 123 nbuf = realloc(iov->iov_base, len);124 if (!nbuf)125 return -ENOMEM;126 127 iov->iov_base = nbuf;128 iov->iov_len = len;129 return 0;130}131 132static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq,133 __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,134 void *cookie)135{136 struct iovec iov = {};137 struct msghdr mhdr = {138 .msg_iov = &iov,139 .msg_iovlen = 1,140 };141 bool multipart = true;142 struct nlmsgerr *err;143 struct nlmsghdr *nh;144 int len, ret;145 146 ret = alloc_iov(&iov, 4096);147 if (ret)148 goto done;149 150 while (multipart) {151start:152 multipart = false;153 len = netlink_recvmsg(sock, &mhdr, MSG_PEEK | MSG_TRUNC);154 if (len < 0) {155 ret = len;156 goto done;157 }158 159 if (len > iov.iov_len) {160 ret = alloc_iov(&iov, len);161 if (ret)162 goto done;163 }164 165 len = netlink_recvmsg(sock, &mhdr, 0);166 if (len < 0) {167 ret = len;168 goto done;169 }170 171 if (len == 0)172 break;173 174 for (nh = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(nh, len);175 nh = NLMSG_NEXT(nh, len)) {176 if (nh->nlmsg_pid != nl_pid) {177 ret = -LIBBPF_ERRNO__WRNGPID;178 goto done;179 }180 if (nh->nlmsg_seq != seq) {181 ret = -LIBBPF_ERRNO__INVSEQ;182 goto done;183 }184 if (nh->nlmsg_flags & NLM_F_MULTI)185 multipart = true;186 switch (nh->nlmsg_type) {187 case NLMSG_ERROR:188 err = (struct nlmsgerr *)NLMSG_DATA(nh);189 if (!err->error)190 continue;191 ret = err->error;192 libbpf_nla_dump_errormsg(nh);193 goto done;194 case NLMSG_DONE:195 ret = 0;196 goto done;197 default:198 break;199 }200 if (_fn) {201 ret = _fn(nh, fn, cookie);202 switch (ret) {203 case NL_CONT:204 break;205 case NL_NEXT:206 goto start;207 case NL_DONE:208 ret = 0;209 goto done;210 default:211 goto done;212 }213 }214 }215 }216 ret = 0;217done:218 free(iov.iov_base);219 return ret;220}221 222static int libbpf_netlink_send_recv(struct libbpf_nla_req *req,223 int proto, __dump_nlmsg_t parse_msg,224 libbpf_dump_nlmsg_t parse_attr,225 void *cookie)226{227 __u32 nl_pid = 0;228 int sock, ret;229 230 sock = libbpf_netlink_open(&nl_pid, proto);231 if (sock < 0)232 return sock;233 234 req->nh.nlmsg_pid = 0;235 req->nh.nlmsg_seq = time(NULL);236 237 if (send(sock, req, req->nh.nlmsg_len, 0) < 0) {238 ret = -errno;239 goto out;240 }241 242 ret = libbpf_netlink_recv(sock, nl_pid, req->nh.nlmsg_seq,243 parse_msg, parse_attr, cookie);244out:245 libbpf_netlink_close(sock);246 return ret;247}248 249static int parse_genl_family_id(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,250 void *cookie)251{252 struct genlmsghdr *gnl = NLMSG_DATA(nh);253 struct nlattr *na = (struct nlattr *)((void *)gnl + GENL_HDRLEN);254 struct nlattr *tb[CTRL_ATTR_FAMILY_ID + 1];255 __u16 *id = cookie;256 257 libbpf_nla_parse(tb, CTRL_ATTR_FAMILY_ID, na,258 NLMSG_PAYLOAD(nh, sizeof(*gnl)), NULL);259 if (!tb[CTRL_ATTR_FAMILY_ID])260 return NL_CONT;261 262 *id = libbpf_nla_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);263 return NL_DONE;264}265 266static int libbpf_netlink_resolve_genl_family_id(const char *name,267 __u16 len, __u16 *id)268{269 struct libbpf_nla_req req = {270 .nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN),271 .nh.nlmsg_type = GENL_ID_CTRL,272 .nh.nlmsg_flags = NLM_F_REQUEST,273 .gnl.cmd = CTRL_CMD_GETFAMILY,274 .gnl.version = 2,275 };276 int err;277 278 err = nlattr_add(&req, CTRL_ATTR_FAMILY_NAME, name, len);279 if (err < 0)280 return err;281 282 return libbpf_netlink_send_recv(&req, NETLINK_GENERIC,283 parse_genl_family_id, NULL, id);284}285 286static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd,287 __u32 flags)288{289 struct nlattr *nla;290 int ret;291 struct libbpf_nla_req req;292 293 memset(&req, 0, sizeof(req));294 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));295 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;296 req.nh.nlmsg_type = RTM_SETLINK;297 req.ifinfo.ifi_family = AF_UNSPEC;298 req.ifinfo.ifi_index = ifindex;299 300 nla = nlattr_begin_nested(&req, IFLA_XDP);301 if (!nla)302 return -EMSGSIZE;303 ret = nlattr_add(&req, IFLA_XDP_FD, &fd, sizeof(fd));304 if (ret < 0)305 return ret;306 if (flags) {307 ret = nlattr_add(&req, IFLA_XDP_FLAGS, &flags, sizeof(flags));308 if (ret < 0)309 return ret;310 }311 if (flags & XDP_FLAGS_REPLACE) {312 ret = nlattr_add(&req, IFLA_XDP_EXPECTED_FD, &old_fd,313 sizeof(old_fd));314 if (ret < 0)315 return ret;316 }317 nlattr_end_nested(&req, nla);318 319 return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);320}321 322int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, const struct bpf_xdp_attach_opts *opts)323{324 int old_prog_fd, err;325 326 if (!OPTS_VALID(opts, bpf_xdp_attach_opts))327 return libbpf_err(-EINVAL);328 329 old_prog_fd = OPTS_GET(opts, old_prog_fd, 0);330 if (old_prog_fd)331 flags |= XDP_FLAGS_REPLACE;332 else333 old_prog_fd = -1;334 335 err = __bpf_set_link_xdp_fd_replace(ifindex, prog_fd, old_prog_fd, flags);336 return libbpf_err(err);337}338 339int bpf_xdp_detach(int ifindex, __u32 flags, const struct bpf_xdp_attach_opts *opts)340{341 return bpf_xdp_attach(ifindex, -1, flags, opts);342}343 344static int __dump_link_nlmsg(struct nlmsghdr *nlh,345 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)346{347 struct nlattr *tb[IFLA_MAX + 1], *attr;348 struct ifinfomsg *ifi = NLMSG_DATA(nlh);349 int len;350 351 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));352 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));353 354 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)355 return -LIBBPF_ERRNO__NLPARSE;356 357 return dump_link_nlmsg(cookie, ifi, tb);358}359 360static int get_xdp_info(void *cookie, void *msg, struct nlattr **tb)361{362 struct nlattr *xdp_tb[IFLA_XDP_MAX + 1];363 struct xdp_id_md *xdp_id = cookie;364 struct ifinfomsg *ifinfo = msg;365 int ret;366 367 if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index)368 return 0;369 370 if (!tb[IFLA_XDP])371 return 0;372 373 ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL);374 if (ret)375 return ret;376 377 if (!xdp_tb[IFLA_XDP_ATTACHED])378 return 0;379 380 xdp_id->info.attach_mode = libbpf_nla_getattr_u8(381 xdp_tb[IFLA_XDP_ATTACHED]);382 383 if (xdp_id->info.attach_mode == XDP_ATTACHED_NONE)384 return 0;385 386 if (xdp_tb[IFLA_XDP_PROG_ID])387 xdp_id->info.prog_id = libbpf_nla_getattr_u32(388 xdp_tb[IFLA_XDP_PROG_ID]);389 390 if (xdp_tb[IFLA_XDP_SKB_PROG_ID])391 xdp_id->info.skb_prog_id = libbpf_nla_getattr_u32(392 xdp_tb[IFLA_XDP_SKB_PROG_ID]);393 394 if (xdp_tb[IFLA_XDP_DRV_PROG_ID])395 xdp_id->info.drv_prog_id = libbpf_nla_getattr_u32(396 xdp_tb[IFLA_XDP_DRV_PROG_ID]);397 398 if (xdp_tb[IFLA_XDP_HW_PROG_ID])399 xdp_id->info.hw_prog_id = libbpf_nla_getattr_u32(400 xdp_tb[IFLA_XDP_HW_PROG_ID]);401 402 return 0;403}404 405static int parse_xdp_features(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,406 void *cookie)407{408 struct genlmsghdr *gnl = NLMSG_DATA(nh);409 struct nlattr *na = (struct nlattr *)((void *)gnl + GENL_HDRLEN);410 struct nlattr *tb[NETDEV_CMD_MAX + 1];411 struct xdp_features_md *md = cookie;412 __u32 ifindex;413 414 libbpf_nla_parse(tb, NETDEV_CMD_MAX, na,415 NLMSG_PAYLOAD(nh, sizeof(*gnl)), NULL);416 417 if (!tb[NETDEV_A_DEV_IFINDEX] || !tb[NETDEV_A_DEV_XDP_FEATURES])418 return NL_CONT;419 420 ifindex = libbpf_nla_getattr_u32(tb[NETDEV_A_DEV_IFINDEX]);421 if (ifindex != md->ifindex)422 return NL_CONT;423 424 md->flags = libbpf_nla_getattr_u64(tb[NETDEV_A_DEV_XDP_FEATURES]);425 if (tb[NETDEV_A_DEV_XDP_ZC_MAX_SEGS])426 md->xdp_zc_max_segs =427 libbpf_nla_getattr_u32(tb[NETDEV_A_DEV_XDP_ZC_MAX_SEGS]);428 return NL_DONE;429}430 431int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)432{433 struct libbpf_nla_req req = {434 .nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),435 .nh.nlmsg_type = RTM_GETLINK,436 .nh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,437 .ifinfo.ifi_family = AF_PACKET,438 };439 struct xdp_id_md xdp_id = {};440 struct xdp_features_md md = {441 .ifindex = ifindex,442 };443 __u16 id;444 int err;445 446 if (!OPTS_VALID(opts, bpf_xdp_query_opts))447 return libbpf_err(-EINVAL);448 449 if (xdp_flags & ~XDP_FLAGS_MASK)450 return libbpf_err(-EINVAL);451 452 /* Check whether the single {HW,DRV,SKB} mode is set */453 xdp_flags &= XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE;454 if (xdp_flags & (xdp_flags - 1))455 return libbpf_err(-EINVAL);456 457 xdp_id.ifindex = ifindex;458 xdp_id.flags = xdp_flags;459 460 err = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, __dump_link_nlmsg,461 get_xdp_info, &xdp_id);462 if (err)463 return libbpf_err(err);464 465 OPTS_SET(opts, prog_id, xdp_id.info.prog_id);466 OPTS_SET(opts, drv_prog_id, xdp_id.info.drv_prog_id);467 OPTS_SET(opts, hw_prog_id, xdp_id.info.hw_prog_id);468 OPTS_SET(opts, skb_prog_id, xdp_id.info.skb_prog_id);469 OPTS_SET(opts, attach_mode, xdp_id.info.attach_mode);470 471 if (!OPTS_HAS(opts, feature_flags))472 return 0;473 474 err = libbpf_netlink_resolve_genl_family_id("netdev", sizeof("netdev"), &id);475 if (err < 0) {476 if (err == -ENOENT) {477 opts->feature_flags = 0;478 goto skip_feature_flags;479 }480 return libbpf_err(err);481 }482 483 memset(&req, 0, sizeof(req));484 req.nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);485 req.nh.nlmsg_flags = NLM_F_REQUEST;486 req.nh.nlmsg_type = id;487 req.gnl.cmd = NETDEV_CMD_DEV_GET;488 req.gnl.version = 2;489 490 err = nlattr_add(&req, NETDEV_A_DEV_IFINDEX, &ifindex, sizeof(ifindex));491 if (err < 0)492 return libbpf_err(err);493 494 err = libbpf_netlink_send_recv(&req, NETLINK_GENERIC,495 parse_xdp_features, NULL, &md);496 if (err)497 return libbpf_err(err);498 499 OPTS_SET(opts, feature_flags, md.flags);500 OPTS_SET(opts, xdp_zc_max_segs, md.xdp_zc_max_segs);501 502skip_feature_flags:503 return 0;504}505 506int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id)507{508 LIBBPF_OPTS(bpf_xdp_query_opts, opts);509 int ret;510 511 ret = bpf_xdp_query(ifindex, flags, &opts);512 if (ret)513 return libbpf_err(ret);514 515 flags &= XDP_FLAGS_MODES;516 517 if (opts.attach_mode != XDP_ATTACHED_MULTI && !flags)518 *prog_id = opts.prog_id;519 else if (flags & XDP_FLAGS_DRV_MODE)520 *prog_id = opts.drv_prog_id;521 else if (flags & XDP_FLAGS_HW_MODE)522 *prog_id = opts.hw_prog_id;523 else if (flags & XDP_FLAGS_SKB_MODE)524 *prog_id = opts.skb_prog_id;525 else526 *prog_id = 0;527 528 return 0;529}530 531 532typedef int (*qdisc_config_t)(struct libbpf_nla_req *req);533 534static int clsact_config(struct libbpf_nla_req *req)535{536 req->tc.tcm_parent = TC_H_CLSACT;537 req->tc.tcm_handle = TC_H_MAKE(TC_H_CLSACT, 0);538 539 return nlattr_add(req, TCA_KIND, "clsact", sizeof("clsact"));540}541 542static int attach_point_to_config(struct bpf_tc_hook *hook,543 qdisc_config_t *config)544{545 switch (OPTS_GET(hook, attach_point, 0)) {546 case BPF_TC_INGRESS:547 case BPF_TC_EGRESS:548 case BPF_TC_INGRESS | BPF_TC_EGRESS:549 if (OPTS_GET(hook, parent, 0))550 return -EINVAL;551 *config = &clsact_config;552 return 0;553 case BPF_TC_CUSTOM:554 return -EOPNOTSUPP;555 default:556 return -EINVAL;557 }558}559 560static int tc_get_tcm_parent(enum bpf_tc_attach_point attach_point,561 __u32 *parent)562{563 switch (attach_point) {564 case BPF_TC_INGRESS:565 case BPF_TC_EGRESS:566 if (*parent)567 return -EINVAL;568 *parent = TC_H_MAKE(TC_H_CLSACT,569 attach_point == BPF_TC_INGRESS ?570 TC_H_MIN_INGRESS : TC_H_MIN_EGRESS);571 break;572 case BPF_TC_CUSTOM:573 if (!*parent)574 return -EINVAL;575 break;576 default:577 return -EINVAL;578 }579 return 0;580}581 582static int tc_qdisc_modify(struct bpf_tc_hook *hook, int cmd, int flags)583{584 qdisc_config_t config;585 int ret;586 struct libbpf_nla_req req;587 588 ret = attach_point_to_config(hook, &config);589 if (ret < 0)590 return ret;591 592 memset(&req, 0, sizeof(req));593 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));594 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;595 req.nh.nlmsg_type = cmd;596 req.tc.tcm_family = AF_UNSPEC;597 req.tc.tcm_ifindex = OPTS_GET(hook, ifindex, 0);598 599 ret = config(&req);600 if (ret < 0)601 return ret;602 603 return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);604}605 606static int tc_qdisc_create_excl(struct bpf_tc_hook *hook)607{608 return tc_qdisc_modify(hook, RTM_NEWQDISC, NLM_F_CREATE | NLM_F_EXCL);609}610 611static int tc_qdisc_delete(struct bpf_tc_hook *hook)612{613 return tc_qdisc_modify(hook, RTM_DELQDISC, 0);614}615 616int bpf_tc_hook_create(struct bpf_tc_hook *hook)617{618 int ret;619 620 if (!hook || !OPTS_VALID(hook, bpf_tc_hook) ||621 OPTS_GET(hook, ifindex, 0) <= 0)622 return libbpf_err(-EINVAL);623 624 ret = tc_qdisc_create_excl(hook);625 return libbpf_err(ret);626}627 628static int __bpf_tc_detach(const struct bpf_tc_hook *hook,629 const struct bpf_tc_opts *opts,630 const bool flush);631 632int bpf_tc_hook_destroy(struct bpf_tc_hook *hook)633{634 if (!hook || !OPTS_VALID(hook, bpf_tc_hook) ||635 OPTS_GET(hook, ifindex, 0) <= 0)636 return libbpf_err(-EINVAL);637 638 switch (OPTS_GET(hook, attach_point, 0)) {639 case BPF_TC_INGRESS:640 case BPF_TC_EGRESS:641 return libbpf_err(__bpf_tc_detach(hook, NULL, true));642 case BPF_TC_INGRESS | BPF_TC_EGRESS:643 return libbpf_err(tc_qdisc_delete(hook));644 case BPF_TC_CUSTOM:645 return libbpf_err(-EOPNOTSUPP);646 default:647 return libbpf_err(-EINVAL);648 }649}650 651struct bpf_cb_ctx {652 struct bpf_tc_opts *opts;653 bool processed;654};655 656static int __get_tc_info(void *cookie, struct tcmsg *tc, struct nlattr **tb,657 bool unicast)658{659 struct nlattr *tbb[TCA_BPF_MAX + 1];660 struct bpf_cb_ctx *info = cookie;661 662 if (!info || !info->opts)663 return -EINVAL;664 if (unicast && info->processed)665 return -EINVAL;666 if (!tb[TCA_OPTIONS])667 return NL_CONT;668 669 libbpf_nla_parse_nested(tbb, TCA_BPF_MAX, tb[TCA_OPTIONS], NULL);670 if (!tbb[TCA_BPF_ID])671 return -EINVAL;672 673 OPTS_SET(info->opts, prog_id, libbpf_nla_getattr_u32(tbb[TCA_BPF_ID]));674 OPTS_SET(info->opts, handle, tc->tcm_handle);675 OPTS_SET(info->opts, priority, TC_H_MAJ(tc->tcm_info) >> 16);676 677 info->processed = true;678 return unicast ? NL_NEXT : NL_DONE;679}680 681static int get_tc_info(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,682 void *cookie)683{684 struct tcmsg *tc = NLMSG_DATA(nh);685 struct nlattr *tb[TCA_MAX + 1];686 687 libbpf_nla_parse(tb, TCA_MAX,688 (struct nlattr *)((void *)tc + NLMSG_ALIGN(sizeof(*tc))),689 NLMSG_PAYLOAD(nh, sizeof(*tc)), NULL);690 if (!tb[TCA_KIND])691 return NL_CONT;692 return __get_tc_info(cookie, tc, tb, nh->nlmsg_flags & NLM_F_ECHO);693}694 695static int tc_add_fd_and_name(struct libbpf_nla_req *req, int fd)696{697 struct bpf_prog_info info;698 __u32 info_len = sizeof(info);699 char name[256];700 int len, ret;701 702 memset(&info, 0, info_len);703 ret = bpf_prog_get_info_by_fd(fd, &info, &info_len);704 if (ret < 0)705 return ret;706 707 ret = nlattr_add(req, TCA_BPF_FD, &fd, sizeof(fd));708 if (ret < 0)709 return ret;710 len = snprintf(name, sizeof(name), "%s:[%u]", info.name, info.id);711 if (len < 0)712 return -errno;713 if (len >= sizeof(name))714 return -ENAMETOOLONG;715 return nlattr_add(req, TCA_BPF_NAME, name, len + 1);716}717 718int bpf_tc_attach(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts)719{720 __u32 protocol, bpf_flags, handle, priority, parent, prog_id, flags;721 int ret, ifindex, attach_point, prog_fd;722 struct bpf_cb_ctx info = {};723 struct libbpf_nla_req req;724 struct nlattr *nla;725 726 if (!hook || !opts ||727 !OPTS_VALID(hook, bpf_tc_hook) ||728 !OPTS_VALID(opts, bpf_tc_opts))729 return libbpf_err(-EINVAL);730 731 ifindex = OPTS_GET(hook, ifindex, 0);732 parent = OPTS_GET(hook, parent, 0);733 attach_point = OPTS_GET(hook, attach_point, 0);734 735 handle = OPTS_GET(opts, handle, 0);736 priority = OPTS_GET(opts, priority, 0);737 prog_fd = OPTS_GET(opts, prog_fd, 0);738 prog_id = OPTS_GET(opts, prog_id, 0);739 flags = OPTS_GET(opts, flags, 0);740 741 if (ifindex <= 0 || !prog_fd || prog_id)742 return libbpf_err(-EINVAL);743 if (priority > UINT16_MAX)744 return libbpf_err(-EINVAL);745 if (flags & ~BPF_TC_F_REPLACE)746 return libbpf_err(-EINVAL);747 748 flags = (flags & BPF_TC_F_REPLACE) ? NLM_F_REPLACE : NLM_F_EXCL;749 protocol = ETH_P_ALL;750 751 memset(&req, 0, sizeof(req));752 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));753 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_CREATE |754 NLM_F_ECHO | flags;755 req.nh.nlmsg_type = RTM_NEWTFILTER;756 req.tc.tcm_family = AF_UNSPEC;757 req.tc.tcm_ifindex = ifindex;758 req.tc.tcm_handle = handle;759 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));760 761 ret = tc_get_tcm_parent(attach_point, &parent);762 if (ret < 0)763 return libbpf_err(ret);764 req.tc.tcm_parent = parent;765 766 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));767 if (ret < 0)768 return libbpf_err(ret);769 nla = nlattr_begin_nested(&req, TCA_OPTIONS);770 if (!nla)771 return libbpf_err(-EMSGSIZE);772 ret = tc_add_fd_and_name(&req, prog_fd);773 if (ret < 0)774 return libbpf_err(ret);775 bpf_flags = TCA_BPF_FLAG_ACT_DIRECT;776 ret = nlattr_add(&req, TCA_BPF_FLAGS, &bpf_flags, sizeof(bpf_flags));777 if (ret < 0)778 return libbpf_err(ret);779 nlattr_end_nested(&req, nla);780 781 info.opts = opts;782 783 ret = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, get_tc_info, NULL,784 &info);785 if (ret < 0)786 return libbpf_err(ret);787 if (!info.processed)788 return libbpf_err(-ENOENT);789 return ret;790}791 792static int __bpf_tc_detach(const struct bpf_tc_hook *hook,793 const struct bpf_tc_opts *opts,794 const bool flush)795{796 __u32 protocol = 0, handle, priority, parent, prog_id, flags;797 int ret, ifindex, attach_point, prog_fd;798 struct libbpf_nla_req req;799 800 if (!hook ||801 !OPTS_VALID(hook, bpf_tc_hook) ||802 !OPTS_VALID(opts, bpf_tc_opts))803 return -EINVAL;804 805 ifindex = OPTS_GET(hook, ifindex, 0);806 parent = OPTS_GET(hook, parent, 0);807 attach_point = OPTS_GET(hook, attach_point, 0);808 809 handle = OPTS_GET(opts, handle, 0);810 priority = OPTS_GET(opts, priority, 0);811 prog_fd = OPTS_GET(opts, prog_fd, 0);812 prog_id = OPTS_GET(opts, prog_id, 0);813 flags = OPTS_GET(opts, flags, 0);814 815 if (ifindex <= 0 || flags || prog_fd || prog_id)816 return -EINVAL;817 if (priority > UINT16_MAX)818 return -EINVAL;819 if (!flush) {820 if (!handle || !priority)821 return -EINVAL;822 protocol = ETH_P_ALL;823 } else {824 if (handle || priority)825 return -EINVAL;826 }827 828 memset(&req, 0, sizeof(req));829 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));830 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;831 req.nh.nlmsg_type = RTM_DELTFILTER;832 req.tc.tcm_family = AF_UNSPEC;833 req.tc.tcm_ifindex = ifindex;834 if (!flush) {835 req.tc.tcm_handle = handle;836 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));837 }838 839 ret = tc_get_tcm_parent(attach_point, &parent);840 if (ret < 0)841 return ret;842 req.tc.tcm_parent = parent;843 844 if (!flush) {845 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));846 if (ret < 0)847 return ret;848 }849 850 return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);851}852 853int bpf_tc_detach(const struct bpf_tc_hook *hook,854 const struct bpf_tc_opts *opts)855{856 int ret;857 858 if (!opts)859 return libbpf_err(-EINVAL);860 861 ret = __bpf_tc_detach(hook, opts, false);862 return libbpf_err(ret);863}864 865int bpf_tc_query(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts)866{867 __u32 protocol, handle, priority, parent, prog_id, flags;868 int ret, ifindex, attach_point, prog_fd;869 struct bpf_cb_ctx info = {};870 struct libbpf_nla_req req;871 872 if (!hook || !opts ||873 !OPTS_VALID(hook, bpf_tc_hook) ||874 !OPTS_VALID(opts, bpf_tc_opts))875 return libbpf_err(-EINVAL);876 877 ifindex = OPTS_GET(hook, ifindex, 0);878 parent = OPTS_GET(hook, parent, 0);879 attach_point = OPTS_GET(hook, attach_point, 0);880 881 handle = OPTS_GET(opts, handle, 0);882 priority = OPTS_GET(opts, priority, 0);883 prog_fd = OPTS_GET(opts, prog_fd, 0);884 prog_id = OPTS_GET(opts, prog_id, 0);885 flags = OPTS_GET(opts, flags, 0);886 887 if (ifindex <= 0 || flags || prog_fd || prog_id ||888 !handle || !priority)889 return libbpf_err(-EINVAL);890 if (priority > UINT16_MAX)891 return libbpf_err(-EINVAL);892 893 protocol = ETH_P_ALL;894 895 memset(&req, 0, sizeof(req));896 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));897 req.nh.nlmsg_flags = NLM_F_REQUEST;898 req.nh.nlmsg_type = RTM_GETTFILTER;899 req.tc.tcm_family = AF_UNSPEC;900 req.tc.tcm_ifindex = ifindex;901 req.tc.tcm_handle = handle;902 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));903 904 ret = tc_get_tcm_parent(attach_point, &parent);905 if (ret < 0)906 return libbpf_err(ret);907 req.tc.tcm_parent = parent;908 909 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));910 if (ret < 0)911 return libbpf_err(ret);912 913 info.opts = opts;914 915 ret = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, get_tc_info, NULL,916 &info);917 if (ret < 0)918 return libbpf_err(ret);919 if (!info.processed)920 return libbpf_err(-ENOENT);921 return ret;922}923