tools/bpf/bpftool/net.c

   1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 // Copyright (C) 2018 Facebook
   3
   4 #ifndef _GNU_SOURCE
   5 #define _GNU_SOURCE
   6 #endif
   7 #include <errno.h>
   8 #include <fcntl.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <time.h>
  12 #include <unistd.h>
  13 #include <bpf/bpf.h>
  14 #include <bpf/libbpf.h>
  15 #include <net/if.h>
  16 #include <linux/rtnetlink.h>
  17 #include <linux/socket.h>
  18 #include <linux/tc_act/tc_bpf.h>
  19 #include <sys/socket.h>
  20 #include <sys/stat.h>
  21 #include <sys/types.h>
  22
  23 #include "bpf/nlattr.h"
  24 #include "main.h"
  25 #include "netlink_dumper.h"
  26
  27 #ifndef SOL_NETLINK
  28 #define SOL_NETLINK 270
  29 #endif
  30
  31 struct ip_devname_ifindex {
  32         char    devname[64];
  33         int     ifindex;
  34 };
  35
  36 struct bpf_netdev_t {
  37         struct ip_devname_ifindex *devices;
  38         int     used_len;
  39         int     array_len;
  40         int     filter_idx;
  41 };
  42
  43 struct tc_kind_handle {
  44         char    kind[64];
  45         int     handle;
  46 };
  47
  48 struct bpf_tcinfo_t {
  49         struct tc_kind_handle   *handle_array;
  50         int                     used_len;
  51         int                     array_len;
  52         bool                    is_qdisc;
  53 };
  54
  55 struct bpf_filter_t {
  56         const char      *kind;
  57         const char      *devname;
  58         int             ifindex;
  59 };
  60
  61 struct bpf_attach_info {
  62         __u32 flow_dissector_id;
  63 };
  64
  65 enum net_attach_type {
  66         NET_ATTACH_TYPE_XDP,
  67         NET_ATTACH_TYPE_XDP_GENERIC,
  68         NET_ATTACH_TYPE_XDP_DRIVER,
  69         NET_ATTACH_TYPE_XDP_OFFLOAD,
  70 };
  71
  72 static const char * const attach_type_strings[] = {
  73         [NET_ATTACH_TYPE_XDP]           = "xdp",
  74         [NET_ATTACH_TYPE_XDP_GENERIC]   = "xdpgeneric",
  75         [NET_ATTACH_TYPE_XDP_DRIVER]    = "xdpdrv",
  76         [NET_ATTACH_TYPE_XDP_OFFLOAD]   = "xdpoffload",
  77 };
  78
  79 static const char * const attach_loc_strings[] = {
  80         [BPF_TCX_INGRESS]               = "tcx/ingress",
  81         [BPF_TCX_EGRESS]                = "tcx/egress",
  82         [BPF_NETKIT_PRIMARY]            = "netkit/primary",
  83         [BPF_NETKIT_PEER]               = "netkit/peer",
  84 };
  85
  86 const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings);
  87
  88 static enum net_attach_type parse_attach_type(const char *str)
  89 {
  90         enum net_attach_type type;
  91
  92         for (type = 0; type < net_attach_type_size; type++) {
  93                 if (attach_type_strings[type] &&
  94                     is_prefix(str, attach_type_strings[type]))
  95                         return type;
  96         }
  97
  98         return net_attach_type_size;
  99 }
 100
 101 typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
 102
 103 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie);
 104
 105 static int netlink_open(__u32 *nl_pid)
 106 {
 107         struct sockaddr_nl sa;
 108         socklen_t addrlen;
 109         int one = 1, ret;
 110         int sock;
 111
 112         memset(&sa, 0, sizeof(sa));
 113         sa.nl_family = AF_NETLINK;
 114
 115         sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 116         if (sock < 0)
 117                 return -errno;
 118
 119         if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
 120                        &one, sizeof(one)) < 0) {
 121                 p_err("Netlink error reporting not supported");
 122         }
 123
 124         if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
 125                 ret = -errno;
 126                 goto cleanup;
 127         }
 128
 129         addrlen = sizeof(sa);
 130         if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
 131                 ret = -errno;
 132                 goto cleanup;
 133         }
 134
 135         if (addrlen != sizeof(sa)) {
 136                 ret = -LIBBPF_ERRNO__INTERNAL;
 137                 goto cleanup;
 138         }
 139
 140         *nl_pid = sa.nl_pid;
 141         return sock;
 142
 143 cleanup:
 144         close(sock);
 145         return ret;
 146 }
 147
 148 static int netlink_recv(int sock, __u32 nl_pid, __u32 seq,
 149                             __dump_nlmsg_t _fn, dump_nlmsg_t fn,
 150                             void *cookie)
 151 {
 152         bool multipart = true;
 153         struct nlmsgerr *err;
 154         struct nlmsghdr *nh;
 155         char buf[4096];
 156         int len, ret;
 157
 158         while (multipart) {
 159                 multipart = false;
 160                 len = recv(sock, buf, sizeof(buf), 0);
 161                 if (len < 0) {
 162                         ret = -errno;
 163                         goto done;
 164                 }
 165
 166                 if (len == 0)
 167                         break;
 168
 169                 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, (unsigned int)len);
 170                      nh = NLMSG_NEXT(nh, len)) {
 171                         if (nh->nlmsg_pid != nl_pid) {
 172                                 ret = -LIBBPF_ERRNO__WRNGPID;
 173                                 goto done;
 174                         }
 175                         if (nh->nlmsg_seq != seq) {
 176                                 ret = -LIBBPF_ERRNO__INVSEQ;
 177                                 goto done;
 178                         }
 179                         if (nh->nlmsg_flags & NLM_F_MULTI)
 180                                 multipart = true;
 181                         switch (nh->nlmsg_type) {
 182                         case NLMSG_ERROR:
 183                                 err = (struct nlmsgerr *)NLMSG_DATA(nh);
 184                                 if (!err->error)
 185                                         continue;
 186                                 ret = err->error;
 187                                 libbpf_nla_dump_errormsg(nh);
 188                                 goto done;
 189                         case NLMSG_DONE:
 190                                 return 0;
 191                         default:
 192                                 break;
 193                         }
 194                         if (_fn) {
 195                                 ret = _fn(nh, fn, cookie);
 196                                 if (ret)
 197                                         return ret;
 198                         }
 199                 }
 200         }
 201         ret = 0;
 202 done:
 203         return ret;
 204 }
 205
 206 static int __dump_class_nlmsg(struct nlmsghdr *nlh,
 207                               dump_nlmsg_t dump_class_nlmsg,
 208                               void *cookie)
 209 {
 210         struct nlattr *tb[TCA_MAX + 1], *attr;
 211         struct tcmsg *t = NLMSG_DATA(nlh);
 212         int len;
 213
 214         len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
 215         attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
 216         if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
 217                 return -LIBBPF_ERRNO__NLPARSE;
 218
 219         return dump_class_nlmsg(cookie, t, tb);
 220 }
 221
 222 static int netlink_get_class(int sock, unsigned int nl_pid, int ifindex,
 223                              dump_nlmsg_t dump_class_nlmsg, void *cookie)
 224 {
 225         struct {
 226                 struct nlmsghdr nlh;
 227                 struct tcmsg t;
 228         } req = {
 229                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
 230                 .nlh.nlmsg_type = RTM_GETTCLASS,
 231                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 232                 .t.tcm_family = AF_UNSPEC,
 233                 .t.tcm_ifindex = ifindex,
 234         };
 235         int seq = time(NULL);
 236
 237         req.nlh.nlmsg_seq = seq;
 238         if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
 239                 return -errno;
 240
 241         return netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
 242                             dump_class_nlmsg, cookie);
 243 }
 244
 245 static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
 246                               dump_nlmsg_t dump_qdisc_nlmsg,
 247                               void *cookie)
 248 {
 249         struct nlattr *tb[TCA_MAX + 1], *attr;
 250         struct tcmsg *t = NLMSG_DATA(nlh);
 251         int len;
 252
 253         len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
 254         attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
 255         if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
 256                 return -LIBBPF_ERRNO__NLPARSE;
 257
 258         return dump_qdisc_nlmsg(cookie, t, tb);
 259 }
 260
 261 static int netlink_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
 262                              dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
 263 {
 264         struct {
 265                 struct nlmsghdr nlh;
 266                 struct tcmsg t;
 267         } req = {
 268                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
 269                 .nlh.nlmsg_type = RTM_GETQDISC,
 270                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 271                 .t.tcm_family = AF_UNSPEC,
 272                 .t.tcm_ifindex = ifindex,
 273         };
 274         int seq = time(NULL);
 275
 276         req.nlh.nlmsg_seq = seq;
 277         if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
 278                 return -errno;
 279
 280         return netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
 281                             dump_qdisc_nlmsg, cookie);
 282 }
 283
 284 static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
 285                                dump_nlmsg_t dump_filter_nlmsg,
 286                                void *cookie)
 287 {
 288         struct nlattr *tb[TCA_MAX + 1], *attr;
 289         struct tcmsg *t = NLMSG_DATA(nlh);
 290         int len;
 291
 292         len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
 293         attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
 294         if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
 295                 return -LIBBPF_ERRNO__NLPARSE;
 296
 297         return dump_filter_nlmsg(cookie, t, tb);
 298 }
 299
 300 static int netlink_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
 301                               dump_nlmsg_t dump_filter_nlmsg, void *cookie)
 302 {
 303         struct {
 304                 struct nlmsghdr nlh;
 305                 struct tcmsg t;
 306         } req = {
 307                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
 308                 .nlh.nlmsg_type = RTM_GETTFILTER,
 309                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 310                 .t.tcm_family = AF_UNSPEC,
 311                 .t.tcm_ifindex = ifindex,
 312                 .t.tcm_parent = handle,
 313         };
 314         int seq = time(NULL);
 315
 316         req.nlh.nlmsg_seq = seq;
 317         if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
 318                 return -errno;
 319
 320         return netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
 321                             dump_filter_nlmsg, cookie);
 322 }
 323
 324 static int __dump_link_nlmsg(struct nlmsghdr *nlh,
 325                              dump_nlmsg_t dump_link_nlmsg, void *cookie)
 326 {
 327         struct nlattr *tb[IFLA_MAX + 1], *attr;
 328         struct ifinfomsg *ifi = NLMSG_DATA(nlh);
 329         int len;
 330
 331         len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
 332         attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
 333         if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
 334                 return -LIBBPF_ERRNO__NLPARSE;
 335
 336         return dump_link_nlmsg(cookie, ifi, tb);
 337 }
 338
 339 static int netlink_get_link(int sock, unsigned int nl_pid,
 340                             dump_nlmsg_t dump_link_nlmsg, void *cookie)
 341 {
 342         struct {
 343                 struct nlmsghdr nlh;
 344                 struct ifinfomsg ifm;
 345         } req = {
 346                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
 347                 .nlh.nlmsg_type = RTM_GETLINK,
 348                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 349                 .ifm.ifi_family = AF_PACKET,
 350         };
 351         int seq = time(NULL);
 352
 353         req.nlh.nlmsg_seq = seq;
 354         if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
 355                 return -errno;
 356
 357         return netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
 358                             dump_link_nlmsg, cookie);
 359 }
 360
 361 static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb)
 362 {
 363         struct bpf_netdev_t *netinfo = cookie;
 364         struct ifinfomsg *ifinfo = msg;
 365
 366         if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index)
 367                 return 0;
 368
 369         if (netinfo->used_len == netinfo->array_len) {
 370                 netinfo->devices = realloc(netinfo->devices,
 371                         (netinfo->array_len + 16) *
 372                         sizeof(struct ip_devname_ifindex));
 373                 if (!netinfo->devices)
 374                         return -ENOMEM;
 375
 376                 netinfo->array_len += 16;
 377         }
 378         netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index;
 379         snprintf(netinfo->devices[netinfo->used_len].devname,
 380                  sizeof(netinfo->devices[netinfo->used_len].devname),
 381                  "%s",
 382                  tb[IFLA_IFNAME]
 383                          ? libbpf_nla_getattr_str(tb[IFLA_IFNAME])
 384                          : "");
 385         netinfo->used_len++;
 386
 387         return do_xdp_dump(ifinfo, tb);
 388 }
 389
 390 static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb)
 391 {
 392         struct bpf_tcinfo_t *tcinfo = cookie;
 393         struct tcmsg *info = msg;
 394
 395         if (tcinfo->is_qdisc) {
 396                 /* skip clsact qdisc */
 397                 if (tb[TCA_KIND] &&
 398                     strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0)
 399                         return 0;
 400                 if (info->tcm_handle == 0)
 401                         return 0;
 402         }
 403
 404         if (tcinfo->used_len == tcinfo->array_len) {
 405                 tcinfo->handle_array = realloc(tcinfo->handle_array,
 406                         (tcinfo->array_len + 16) * sizeof(struct tc_kind_handle));
 407                 if (!tcinfo->handle_array)
 408                         return -ENOMEM;
 409
 410                 tcinfo->array_len += 16;
 411         }
 412         tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle;
 413         snprintf(tcinfo->handle_array[tcinfo->used_len].kind,
 414                  sizeof(tcinfo->handle_array[tcinfo->used_len].kind),
 415                  "%s",
 416                  tb[TCA_KIND]
 417                          ? libbpf_nla_getattr_str(tb[TCA_KIND])
 418                          : "unknown");
 419         tcinfo->used_len++;
 420
 421         return 0;
 422 }
 423
 424 static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb)
 425 {
 426         const struct bpf_filter_t *filter_info = cookie;
 427
 428         return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind,
 429                               filter_info->devname, filter_info->ifindex);
 430 }
 431
 432 static int __show_dev_tc_bpf_name(__u32 id, char *name, size_t len)
 433 {
 434         struct bpf_prog_info info = {};
 435         __u32 ilen = sizeof(info);
 436         int fd, ret;
 437
 438         fd = bpf_prog_get_fd_by_id(id);
 439         if (fd < 0)
 440                 return fd;
 441         ret = bpf_obj_get_info_by_fd(fd, &info, &ilen);
 442         if (ret < 0)
 443                 goto out;
 444         ret = -ENOENT;
 445         if (info.name[0]) {
 446                 get_prog_full_name(&info, fd, name, len);
 447                 ret = 0;
 448         }
 449 out:
 450         close(fd);
 451         return ret;
 452 }
 453
 454 static void __show_dev_tc_bpf(const struct ip_devname_ifindex *dev,
 455                               const enum bpf_attach_type loc)
 456 {
 457         __u32 prog_flags[64] = {}, link_flags[64] = {}, i, j;
 458         __u32 prog_ids[64] = {}, link_ids[64] = {};
 459         LIBBPF_OPTS(bpf_prog_query_opts, optq);
 460         char prog_name[MAX_PROG_FULL_NAME];
 461         int ret;
 462
 463         optq.prog_ids = prog_ids;
 464         optq.prog_attach_flags = prog_flags;
 465         optq.link_ids = link_ids;
 466         optq.link_attach_flags = link_flags;
 467         optq.count = ARRAY_SIZE(prog_ids);
 468
 469         ret = bpf_prog_query_opts(dev->ifindex, loc, &optq);
 470         if (ret)
 471                 return;
 472         for (i = 0; i < optq.count; i++) {
 473                 NET_START_OBJECT;
 474                 NET_DUMP_STR("devname", "%s", dev->devname);
 475                 NET_DUMP_UINT("ifindex", "(%u)", dev->ifindex);
 476                 NET_DUMP_STR("kind", " %s", attach_loc_strings[loc]);
 477                 ret = __show_dev_tc_bpf_name(prog_ids[i], prog_name,
 478                                              sizeof(prog_name));
 479                 if (!ret)
 480                         NET_DUMP_STR("name", " %s", prog_name);
 481                 NET_DUMP_UINT("prog_id", " prog_id %u ", prog_ids[i]);
 482                 if (prog_flags[i] || json_output) {
 483                         NET_START_ARRAY("prog_flags", "%s ");
 484                         for (j = 0; prog_flags[i] && j < 32; j++) {
 485                                 if (!(prog_flags[i] & (1 << j)))
 486                                         continue;
 487                                 NET_DUMP_UINT_ONLY(1 << j);
 488                         }
 489                         NET_END_ARRAY("");
 490                 }
 491                 if (link_ids[i] || json_output) {
 492                         NET_DUMP_UINT("link_id", "link_id %u ", link_ids[i]);
 493                         if (link_flags[i] || json_output) {
 494                                 NET_START_ARRAY("link_flags", "%s ");
 495                                 for (j = 0; link_flags[i] && j < 32; j++) {
 496                                         if (!(link_flags[i] & (1 << j)))
 497                                                 continue;
 498                                         NET_DUMP_UINT_ONLY(1 << j);
 499                                 }
 500                                 NET_END_ARRAY("");
 501                         }
 502                 }
 503                 NET_END_OBJECT_FINAL;
 504         }
 505 }
 506
 507 static void show_dev_tc_bpf(struct ip_devname_ifindex *dev)
 508 {
 509         __show_dev_tc_bpf(dev, BPF_TCX_INGRESS);
 510         __show_dev_tc_bpf(dev, BPF_TCX_EGRESS);
 511
 512         __show_dev_tc_bpf(dev, BPF_NETKIT_PRIMARY);
 513         __show_dev_tc_bpf(dev, BPF_NETKIT_PEER);
 514 }
 515
 516 static int show_dev_tc_bpf_classic(int sock, unsigned int nl_pid,
 517                                    struct ip_devname_ifindex *dev)
 518 {
 519         struct bpf_filter_t filter_info;
 520         struct bpf_tcinfo_t tcinfo;
 521         int i, handle, ret = 0;
 522
 523         tcinfo.handle_array = NULL;
 524         tcinfo.used_len = 0;
 525         tcinfo.array_len = 0;
 526
 527         tcinfo.is_qdisc = false;
 528         ret = netlink_get_class(sock, nl_pid, dev->ifindex,
 529                                 dump_class_qdisc_nlmsg, &tcinfo);
 530         if (ret)
 531                 goto out;
 532
 533         tcinfo.is_qdisc = true;
 534         ret = netlink_get_qdisc(sock, nl_pid, dev->ifindex,
 535                                 dump_class_qdisc_nlmsg, &tcinfo);
 536         if (ret)
 537                 goto out;
 538
 539         filter_info.devname = dev->devname;
 540         filter_info.ifindex = dev->ifindex;
 541         for (i = 0; i < tcinfo.used_len; i++) {
 542                 filter_info.kind = tcinfo.handle_array[i].kind;
 543                 ret = netlink_get_filter(sock, nl_pid, dev->ifindex,
 544                                          tcinfo.handle_array[i].handle,
 545                                          dump_filter_nlmsg, &filter_info);
 546                 if (ret)
 547                         goto out;
 548         }
 549
 550         /* root, ingress and egress handle */
 551         handle = TC_H_ROOT;
 552         filter_info.kind = "root";
 553         ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
 554                                  dump_filter_nlmsg, &filter_info);
 555         if (ret)
 556                 goto out;
 557
 558         handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
 559         filter_info.kind = "clsact/ingress";
 560         ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
 561                                  dump_filter_nlmsg, &filter_info);
 562         if (ret)
 563                 goto out;
 564
 565         handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS);
 566         filter_info.kind = "clsact/egress";
 567         ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
 568                                  dump_filter_nlmsg, &filter_info);
 569         if (ret)
 570                 goto out;
 571
 572 out:
 573         free(tcinfo.handle_array);
 574         return 0;
 575 }
 576
 577 static int query_flow_dissector(struct bpf_attach_info *attach_info)
 578 {
 579         __u32 attach_flags;
 580         __u32 prog_ids[1];
 581         __u32 prog_cnt;
 582         int err;
 583         int fd;
 584
 585         fd = open("/proc/self/ns/net", O_RDONLY);
 586         if (fd < 0) {
 587                 p_err("can't open /proc/self/ns/net: %s",
 588                       strerror(errno));
 589                 return -1;
 590         }
 591         prog_cnt = ARRAY_SIZE(prog_ids);
 592         err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0,
 593                              &attach_flags, prog_ids, &prog_cnt);
 594         close(fd);
 595         if (err) {
 596                 if (errno == EINVAL) {
 597                         /* Older kernel's don't support querying
 598                          * flow dissector programs.
 599                          */
 600                         errno = 0;
 601                         return 0;
 602                 }
 603                 p_err("can't query prog: %s", strerror(errno));
 604                 return -1;
 605         }
 606
 607         if (prog_cnt == 1)
 608                 attach_info->flow_dissector_id = prog_ids[0];
 609
 610         return 0;
 611 }
 612
 613 static int net_parse_dev(int *argc, char ***argv)
 614 {
 615         int ifindex;
 616
 617         if (is_prefix(**argv, "dev")) {
 618                 NEXT_ARGP();
 619
 620                 ifindex = if_nametoindex(**argv);
 621                 if (!ifindex)
 622                         p_err("invalid devname %s", **argv);
 623
 624                 NEXT_ARGP();
 625         } else {
 626                 p_err("expected 'dev', got: '%s'?", **argv);
 627                 return -1;
 628         }
 629
 630         return ifindex;
 631 }
 632
 633 static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type,
 634                                 int ifindex, bool overwrite)
 635 {
 636         __u32 flags = 0;
 637
 638         if (!overwrite)
 639                 flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 640         if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC)
 641                 flags |= XDP_FLAGS_SKB_MODE;
 642         if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER)
 643                 flags |= XDP_FLAGS_DRV_MODE;
 644         if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD)
 645                 flags |= XDP_FLAGS_HW_MODE;
 646
 647         return bpf_xdp_attach(ifindex, progfd, flags, NULL);
 648 }
 649
 650 static int do_attach(int argc, char **argv)
 651 {
 652         enum net_attach_type attach_type;
 653         int progfd, ifindex, err = 0;
 654         bool overwrite = false;
 655
 656         /* parse attach args */
 657         if (!REQ_ARGS(5))
 658                 return -EINVAL;
 659
 660         attach_type = parse_attach_type(*argv);
 661         if (attach_type == net_attach_type_size) {
 662                 p_err("invalid net attach/detach type: %s", *argv);
 663                 return -EINVAL;
 664         }
 665         NEXT_ARG();
 666
 667         progfd = prog_parse_fd(&argc, &argv);
 668         if (progfd < 0)
 669                 return -EINVAL;
 670
 671         ifindex = net_parse_dev(&argc, &argv);
 672         if (ifindex < 1) {
 673                 err = -EINVAL;
 674                 goto cleanup;
 675         }
 676
 677         if (argc) {
 678                 if (is_prefix(*argv, "overwrite")) {
 679                         overwrite = true;
 680                 } else {
 681                         p_err("expected 'overwrite', got: '%s'?", *argv);
 682                         err = -EINVAL;
 683                         goto cleanup;
 684                 }
 685         }
 686
 687         /* attach xdp prog */
 688         if (is_prefix("xdp", attach_type_strings[attach_type]))
 689                 err = do_attach_detach_xdp(progfd, attach_type, ifindex,
 690                                            overwrite);
 691         if (err) {
 692                 p_err("interface %s attach failed: %s",
 693                       attach_type_strings[attach_type], strerror(-err));
 694                 goto cleanup;
 695         }
 696
 697         if (json_output)
 698                 jsonw_null(json_wtr);
 699 cleanup:
 700         close(progfd);
 701         return err;
 702 }
 703
 704 static int do_detach(int argc, char **argv)
 705 {
 706         enum net_attach_type attach_type;
 707         int progfd, ifindex, err = 0;
 708
 709         /* parse detach args */
 710         if (!REQ_ARGS(3))
 711                 return -EINVAL;
 712
 713         attach_type = parse_attach_type(*argv);
 714         if (attach_type == net_attach_type_size) {
 715                 p_err("invalid net attach/detach type: %s", *argv);
 716                 return -EINVAL;
 717         }
 718         NEXT_ARG();
 719
 720         ifindex = net_parse_dev(&argc, &argv);
 721         if (ifindex < 1)
 722                 return -EINVAL;
 723
 724         /* detach xdp prog */
 725         progfd = -1;
 726         if (is_prefix("xdp", attach_type_strings[attach_type]))
 727                 err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL);
 728
 729         if (err < 0) {
 730                 p_err("interface %s detach failed: %s",
 731                       attach_type_strings[attach_type], strerror(-err));
 732                 return err;
 733         }
 734
 735         if (json_output)
 736                 jsonw_null(json_wtr);
 737
 738         return 0;
 739 }
 740
 741 static int netfilter_link_compar(const void *a, const void *b)
 742 {
 743         const struct bpf_link_info *nfa = a;
 744         const struct bpf_link_info *nfb = b;
 745         int delta;
 746
 747         delta = nfa->netfilter.pf - nfb->netfilter.pf;
 748         if (delta)
 749                 return delta;
 750
 751         delta = nfa->netfilter.hooknum - nfb->netfilter.hooknum;
 752         if (delta)
 753                 return delta;
 754
 755         if (nfa->netfilter.priority < nfb->netfilter.priority)
 756                 return -1;
 757         if (nfa->netfilter.priority > nfb->netfilter.priority)
 758                 return 1;
 759
 760         return nfa->netfilter.flags - nfb->netfilter.flags;
 761 }
 762
 763 static void show_link_netfilter(void)
 764 {
 765         unsigned int nf_link_len = 0, nf_link_count = 0;
 766         struct bpf_link_info *nf_link_info = NULL;
 767         __u32 id = 0;
 768
 769         while (true) {
 770                 struct bpf_link_info info;
 771                 int fd, err;
 772                 __u32 len;
 773
 774                 err = bpf_link_get_next_id(id, &id);
 775                 if (err) {
 776                         if (errno == ENOENT)
 777                                 break;
 778                         p_err("can't get next link: %s (id %d)", strerror(errno), id);
 779                         break;
 780                 }
 781
 782                 fd = bpf_link_get_fd_by_id(id);
 783                 if (fd < 0) {
 784                         p_err("can't get link by id (%u): %s", id, strerror(errno));
 785                         continue;
 786                 }
 787
 788                 memset(&info, 0, sizeof(info));
 789                 len = sizeof(info);
 790
 791                 err = bpf_link_get_info_by_fd(fd, &info, &len);
 792
 793                 close(fd);
 794
 795                 if (err) {
 796                         p_err("can't get link info for fd %d: %s", fd, strerror(errno));
 797                         continue;
 798                 }
 799
 800                 if (info.type != BPF_LINK_TYPE_NETFILTER)
 801                         continue;
 802
 803                 if (nf_link_count >= nf_link_len) {
 804                         static const unsigned int max_link_count = INT_MAX / sizeof(info);
 805                         struct bpf_link_info *expand;
 806
 807                         if (nf_link_count > max_link_count) {
 808                                 p_err("cannot handle more than %u links\n", max_link_count);
 809                                 break;
 810                         }
 811
 812                         nf_link_len += 16;
 813
 814                         expand = realloc(nf_link_info, nf_link_len * sizeof(info));
 815                         if (!expand) {
 816                                 p_err("realloc: %s",  strerror(errno));
 817                                 break;
 818                         }
 819
 820                         nf_link_info = expand;
 821                 }
 822
 823                 nf_link_info[nf_link_count] = info;
 824                 nf_link_count++;
 825         }
 826
 827         qsort(nf_link_info, nf_link_count, sizeof(*nf_link_info), netfilter_link_compar);
 828
 829         for (id = 0; id < nf_link_count; id++) {
 830                 NET_START_OBJECT;
 831                 if (json_output)
 832                         netfilter_dump_json(&nf_link_info[id], json_wtr);
 833                 else
 834                         netfilter_dump_plain(&nf_link_info[id]);
 835
 836                 NET_DUMP_UINT("id", " prog_id %u", nf_link_info[id].prog_id);
 837                 NET_END_OBJECT;
 838         }
 839
 840         free(nf_link_info);
 841 }
 842
 843 static int do_show(int argc, char **argv)
 844 {
 845         struct bpf_attach_info attach_info = {};
 846         int i, sock, ret, filter_idx = -1;
 847         struct bpf_netdev_t dev_array;
 848         unsigned int nl_pid = 0;
 849         char err_buf[256];
 850
 851         if (argc == 2) {
 852                 filter_idx = net_parse_dev(&argc, &argv);
 853                 if (filter_idx < 1)
 854                         return -1;
 855         } else if (argc != 0) {
 856                 usage();
 857         }
 858
 859         ret = query_flow_dissector(&attach_info);
 860         if (ret)
 861                 return -1;
 862
 863         sock = netlink_open(&nl_pid);
 864         if (sock < 0) {
 865                 fprintf(stderr, "failed to open netlink sock\n");
 866                 return -1;
 867         }
 868
 869         dev_array.devices = NULL;
 870         dev_array.used_len = 0;
 871         dev_array.array_len = 0;
 872         dev_array.filter_idx = filter_idx;
 873
 874         if (json_output)
 875                 jsonw_start_array(json_wtr);
 876         NET_START_OBJECT;
 877         NET_START_ARRAY("xdp", "%s:\n");
 878         ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);
 879         NET_END_ARRAY("\n");
 880
 881         if (!ret) {
 882                 NET_START_ARRAY("tc", "%s:\n");
 883                 for (i = 0; i < dev_array.used_len; i++) {
 884                         show_dev_tc_bpf(&dev_array.devices[i]);
 885                         ret = show_dev_tc_bpf_classic(sock, nl_pid,
 886                                                       &dev_array.devices[i]);
 887                         if (ret)
 888                                 break;
 889                 }
 890                 NET_END_ARRAY("\n");
 891         }
 892
 893         NET_START_ARRAY("flow_dissector", "%s:\n");
 894         if (attach_info.flow_dissector_id > 0)
 895                 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id);
 896         NET_END_ARRAY("\n");
 897
 898         NET_START_ARRAY("netfilter", "%s:\n");
 899         show_link_netfilter();
 900         NET_END_ARRAY("\n");
 901
 902         NET_END_OBJECT;
 903         if (json_output)
 904                 jsonw_end_array(json_wtr);
 905
 906         if (ret) {
 907                 if (json_output)
 908                         jsonw_null(json_wtr);
 909                 libbpf_strerror(ret, err_buf, sizeof(err_buf));
 910                 fprintf(stderr, "Error: %s\n", err_buf);
 911         }
 912         free(dev_array.devices);
 913         close(sock);
 914         return ret;
 915 }
 916
 917 static int do_help(int argc, char **argv)
 918 {
 919         if (json_output) {
 920                 jsonw_null(json_wtr);
 921                 return 0;
 922         }
 923
 924         fprintf(stderr,
 925                 "Usage: %1$s %2$s { show | list } [dev <devname>]\n"
 926                 "       %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n"
 927                 "       %1$s %2$s detach ATTACH_TYPE dev <devname>\n"
 928                 "       %1$s %2$s help\n"
 929                 "\n"
 930                 "       " HELP_SPEC_PROGRAM "\n"
 931                 "       ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n"
 932                 "       " HELP_SPEC_OPTIONS " }\n"
 933                 "\n"
 934                 "Note: Only xdp, tcx, tc, netkit, flow_dissector and netfilter attachments\n"
 935                 "      are currently supported.\n"
 936                 "      For progs attached to cgroups, use \"bpftool cgroup\"\n"
 937                 "      to dump program attachments. For program types\n"
 938                 "      sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
 939                 "      consult iproute2.\n"
 940                 "",
 941                 bin_name, argv[-2]);
 942
 943         return 0;
 944 }
 945
 946 static const struct cmd cmds[] = {
 947         { "show",       do_show },
 948         { "list",       do_show },
 949         { "attach",     do_attach },
 950         { "detach",     do_detach },
 951         { "help",       do_help },
 952         { 0 }
 953 };
 954
 955 int do_net(int argc, char **argv)
 956 {
 957         return cmd_select(cmds, argc, argv, do_help);
 958 }