interface.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2021 Felix Fietkau <nbd@nbd.name>
   4  */
   5 #include <sys/types.h>
   6 #include <sys/socket.h>
   7 #include <sys/ioctl.h>
   8 #include <net/if_arp.h>
   9 #include <net/if.h>
  10
  11 #include <unistd.h>
  12 #include <errno.h>
  13
  14 #include <libubox/vlist.h>
  15 #include <libubox/avl-cmp.h>
  16 #include <libubox/uloop.h>
  17
  18 #include "qosify.h"
  19
  20 static void interface_update_cb(struct vlist_tree *tree,
  21                                 struct vlist_node *node_new,
  22                                 struct vlist_node *node_old);
  23
  24 static VLIST_TREE(devices, avl_strcmp, interface_update_cb, true, false);
  25 static VLIST_TREE(interfaces, avl_strcmp, interface_update_cb, true, false);
  26 static int socket_fd;
  27
  28 #define APPEND(_buf, _ofs, _format, ...) _ofs += snprintf(_buf + _ofs, sizeof(_buf) - _ofs, _format, ##__VA_ARGS__)
  29
  30 struct qosify_iface_config {
  31         struct blob_attr *data;
  32
  33         bool ingress;
  34         bool egress;
  35         bool nat;
  36         bool host_isolate;
  37         bool autorate_ingress;
  38
  39         const char *bandwidth_up;
  40         const char *bandwidth_down;
  41         const char *mode;
  42         const char *common_opts;
  43         const char *ingress_opts;
  44         const char *egress_opts;
  45 };
  46
  47
  48 struct qosify_iface {
  49         struct vlist_node node;
  50
  51         char ifname[IFNAMSIZ];
  52         bool active;
  53
  54         bool device;
  55         struct blob_attr *config_data;
  56         struct qosify_iface_config config;
  57 };
  58
  59 enum {
  60         IFACE_ATTR_BW_UP,
  61         IFACE_ATTR_BW_DOWN,
  62         IFACE_ATTR_INGRESS,
  63         IFACE_ATTR_EGRESS,
  64         IFACE_ATTR_MODE,
  65         IFACE_ATTR_NAT,
  66         IFACE_ATTR_HOST_ISOLATE,
  67         IFACE_ATTR_AUTORATE_IN,
  68         IFACE_ATTR_INGRESS_OPTS,
  69         IFACE_ATTR_EGRESS_OPTS,
  70         IFACE_ATTR_OPTS,
  71         __IFACE_ATTR_MAX
  72 };
  73
  74 static inline const char *qosify_iface_name(struct qosify_iface *iface)
  75 {
  76         return iface->node.avl.key;
  77 }
  78
  79 static void
  80 iface_config_parse(struct blob_attr *attr, struct blob_attr **tb)
  81 {
  82         static const struct blobmsg_policy policy[__IFACE_ATTR_MAX] = {
  83                 [IFACE_ATTR_BW_UP] = { "bandwidth_up", BLOBMSG_TYPE_STRING },
  84                 [IFACE_ATTR_BW_DOWN] = { "bandwidth_down", BLOBMSG_TYPE_STRING },
  85                 [IFACE_ATTR_INGRESS] = { "ingress", BLOBMSG_TYPE_BOOL },
  86                 [IFACE_ATTR_EGRESS] = { "egress", BLOBMSG_TYPE_BOOL },
  87                 [IFACE_ATTR_MODE] = { "mode", BLOBMSG_TYPE_STRING },
  88                 [IFACE_ATTR_NAT] = { "nat", BLOBMSG_TYPE_BOOL },
  89                 [IFACE_ATTR_HOST_ISOLATE] = { "host_isolate", BLOBMSG_TYPE_BOOL },
  90                 [IFACE_ATTR_AUTORATE_IN] = { "autorate_ingress", BLOBMSG_TYPE_BOOL },
  91                 [IFACE_ATTR_INGRESS_OPTS] = { "ingress_options", BLOBMSG_TYPE_STRING },
  92                 [IFACE_ATTR_EGRESS_OPTS] = { "egress_options", BLOBMSG_TYPE_STRING },
  93                 [IFACE_ATTR_OPTS] = { "options", BLOBMSG_TYPE_STRING },
  94         };
  95
  96         blobmsg_parse(policy, __IFACE_ATTR_MAX, tb, blobmsg_data(attr), blobmsg_len(attr));
  97 }
  98
  99 static bool
 100 iface_config_equal(struct qosify_iface *if1, struct qosify_iface *if2)
 101 {
 102         struct blob_attr *tb1[__IFACE_ATTR_MAX], *tb2[__IFACE_ATTR_MAX];
 103         int i;
 104
 105         iface_config_parse(if1->config_data, tb1);
 106         iface_config_parse(if2->config_data, tb2);
 107
 108         for (i = 0; i < __IFACE_ATTR_MAX; i++) {
 109                 if (!!tb1[i] != !!tb2[i])
 110                         return false;
 111
 112                 if (!tb1[i])
 113                         continue;
 114
 115                 if (blob_raw_len(tb1[i]) != blob_raw_len(tb2[i]))
 116                         return false;
 117
 118                 if (memcmp(tb1[i], tb2[i], blob_raw_len(tb1[i])) != 0)
 119                         return false;
 120         }
 121
 122         return true;
 123 }
 124
 125 static const char *check_str(struct blob_attr *attr)
 126 {
 127         const char *str = blobmsg_get_string(attr);
 128
 129         if (strchr(str, '\''))
 130                 return NULL;
 131
 132         return str;
 133 }
 134
 135 static void
 136 iface_config_set(struct qosify_iface *iface, struct blob_attr *attr)
 137 {
 138         struct qosify_iface_config *cfg = &iface->config;
 139         struct blob_attr *tb[__IFACE_ATTR_MAX];
 140         struct blob_attr *cur;
 141
 142         iface_config_parse(attr, tb);
 143
 144         memset(cfg, 0, sizeof(*cfg));
 145
 146         /* defaults */
 147         cfg->mode = "diffserv4";
 148         cfg->ingress = true;
 149         cfg->egress = true;
 150         cfg->host_isolate = true;
 151         cfg->autorate_ingress = false;
 152         cfg->nat = !iface->device;
 153
 154         if ((cur = tb[IFACE_ATTR_BW_UP]) != NULL)
 155                 cfg->bandwidth_up = check_str(cur);
 156         if ((cur = tb[IFACE_ATTR_BW_DOWN]) != NULL)
 157                 cfg->bandwidth_down = check_str(cur);
 158         if ((cur = tb[IFACE_ATTR_MODE]) != NULL)
 159                 cfg->mode = check_str(cur);
 160         if ((cur = tb[IFACE_ATTR_OPTS]) != NULL)
 161                 cfg->common_opts = check_str(cur);
 162         if ((cur = tb[IFACE_ATTR_EGRESS_OPTS]) != NULL)
 163                 cfg->egress_opts = check_str(cur);
 164         if ((cur = tb[IFACE_ATTR_INGRESS_OPTS]) != NULL)
 165                 cfg->ingress_opts = check_str(cur);
 166         if ((cur = tb[IFACE_ATTR_INGRESS]) != NULL)
 167                 cfg->ingress = blobmsg_get_bool(cur);
 168         if ((cur = tb[IFACE_ATTR_EGRESS]) != NULL)
 169                 cfg->egress = blobmsg_get_bool(cur);
 170         if ((cur = tb[IFACE_ATTR_NAT]) != NULL)
 171                 cfg->nat = blobmsg_get_bool(cur);
 172         if ((cur = tb[IFACE_ATTR_HOST_ISOLATE]) != NULL)
 173                 cfg->host_isolate = blobmsg_get_bool(cur);
 174         if ((cur = tb[IFACE_ATTR_AUTORATE_IN]) != NULL)
 175                 cfg->autorate_ingress = blobmsg_get_bool(cur);
 176 }
 177
 178 static const char *
 179 interface_ifb_name(struct qosify_iface *iface)
 180 {
 181         static char ifname[IFNAMSIZ + 1] = "ifb-";
 182         int len = strlen(iface->ifname);
 183
 184         if (len + 4 < IFNAMSIZ) {
 185                 snprintf(ifname + 4, IFNAMSIZ - 4, "%s", iface->ifname);
 186
 187                 return ifname;
 188         }
 189
 190         ifname[4] = iface->ifname[0];
 191         ifname[5] = iface->ifname[1];
 192         snprintf(ifname + 6, IFNAMSIZ - 6, "%s", iface->ifname + len - (IFNAMSIZ + 6) - 1);
 193
 194         return ifname;
 195 }
 196
 197 static int
 198 prepare_qdisc_cmd(char *buf, int len, const char *dev, bool add, const char *type)
 199 {
 200         return snprintf(buf, len, "tc qdisc %s dev '%s' %s",
 201                         add ? "add" : "del", dev, type);
 202 }
 203
 204 static int
 205 prepare_filter_cmd(char *buf, int len, const char *dev, int prio, bool add, bool egress)
 206 {
 207         return snprintf(buf, len, "tc filter %s dev '%s' %sgress prio %d",
 208                         add ? "add" : "del", dev, egress ? "e" : "in", prio);
 209 }
 210
 211 static int
 212 cmd_add_bpf_filter(const char *ifname, int prio, bool egress, bool eth)
 213 {
 214         char buf[512];
 215         int ofs;
 216
 217         ofs = prepare_filter_cmd(buf, sizeof(buf), ifname, prio, true, egress);
 218         APPEND(buf, ofs, " bpf object-pinned /sys/fs/bpf/qosify_%sgress_%s verbose direct-action",
 219                egress ? "e" : "in",
 220                    eth ? "eth" : "ip");
 221
 222         return qosify_run_cmd(buf, false);
 223 }
 224
 225 static int
 226 cmd_add_qdisc(struct qosify_iface *iface, const char *ifname, bool egress, bool eth)
 227 {
 228         struct qosify_iface_config *cfg = &iface->config;
 229         const char *bw = egress ? cfg->bandwidth_up : cfg->bandwidth_down;
 230         const char *dir_opts = egress ? cfg->egress_opts : cfg->ingress_opts;
 231         char buf[512];
 232         int ofs;
 233
 234         ofs = prepare_qdisc_cmd(buf, sizeof(buf), ifname, true, "clsact");
 235         qosify_run_cmd(buf, true);
 236
 237         ofs = prepare_qdisc_cmd(buf, sizeof(buf), ifname, true, "root cake");
 238         if (bw)
 239                 APPEND(buf, ofs, " bandwidth %s", bw);
 240
 241         APPEND(buf, ofs, " %s %sgress", cfg->mode, egress ? "e" : "in");
 242         if (!egress && cfg->autorate_ingress)
 243                 APPEND(buf, ofs, " autorate-ingress");
 244
 245         if (cfg->host_isolate)
 246                 APPEND(buf, ofs, " %snat dual-%shost",
 247                         cfg->nat ? "" : "no",
 248                         egress ? "src" : "dst");
 249         else
 250                 APPEND(buf, ofs, " flows");
 251
 252         APPEND(buf, ofs, " %s %s",
 253                cfg->common_opts ? cfg->common_opts : "",
 254                dir_opts ? dir_opts : "");
 255
 256         return qosify_run_cmd(buf, false);
 257 }
 258
 259 static int
 260 cmd_add_ingress(struct qosify_iface *iface, bool eth)
 261 {
 262         const char *ifbdev = interface_ifb_name(iface);
 263         char buf[256];
 264         int prio = QOSIFY_PRIO_BASE;
 265         int ofs;
 266
 267         cmd_add_bpf_filter(iface->ifname, prio++, false, eth);
 268
 269         ofs = prepare_filter_cmd(buf, sizeof(buf), iface->ifname, prio++, true, false);
 270         APPEND(buf, ofs, " protocol ip u32 match ip sport 53 0xffff "
 271                          "flowid 1:1 action mirred egress redirect dev " QOSIFY_DNS_IFNAME);
 272         qosify_run_cmd(buf, false);
 273
 274         ofs = prepare_filter_cmd(buf, sizeof(buf), iface->ifname, prio++, true, false);
 275         APPEND(buf, ofs, " protocol 802.1Q u32 offset plus 4 match ip sport 53 0xffff "
 276                          "flowid 1:1 action mirred egress redirect dev " QOSIFY_DNS_IFNAME);
 277         qosify_run_cmd(buf, false);
 278
 279         ofs = prepare_filter_cmd(buf, sizeof(buf), iface->ifname, prio++, true, false);
 280         APPEND(buf, ofs, " protocol ipv6 u32 match ip6 sport 53 0xffff "
 281                          "flowid 1:1 action mirred egress redirect dev " QOSIFY_DNS_IFNAME);
 282         qosify_run_cmd(buf, false);
 283
 284         ofs = prepare_filter_cmd(buf, sizeof(buf), iface->ifname, prio++, true, false);
 285         APPEND(buf, ofs, " protocol ipv6 u32 offset plus 4 match ip6 sport 53 0xffff "
 286                          "flowid 1:1 action mirred egress redirect dev " QOSIFY_DNS_IFNAME);
 287         qosify_run_cmd(buf, false);
 288
 289
 290         if (!iface->config.ingress)
 291                 return 0;
 292
 293         snprintf(buf, sizeof(buf), "ip link add '%s' type ifb", ifbdev);
 294         qosify_run_cmd(buf, false);
 295
 296         cmd_add_qdisc(iface, ifbdev, false, eth);
 297
 298         snprintf(buf, sizeof(buf), "ip link set dev '%s' up", ifbdev);
 299         qosify_run_cmd(buf, false);
 300
 301         ofs = prepare_filter_cmd(buf, sizeof(buf), iface->ifname, prio++, true, false);
 302         APPEND(buf, ofs, " protocol all u32 match u32 0 0 flowid 1:1"
 303                          " action mirred egress redirect dev '%s'", ifbdev);
 304         return qosify_run_cmd(buf, false);
 305 }
 306
 307 static int cmd_add_egress(struct qosify_iface *iface, bool eth)
 308 {
 309         if (!iface->config.egress)
 310                 return 0;
 311
 312         cmd_add_qdisc(iface, iface->ifname, true, eth);
 313
 314         return cmd_add_bpf_filter(iface->ifname, QOSIFY_PRIO_BASE, true, eth);
 315 }
 316
 317 static void
 318 interface_clear_qdisc(struct qosify_iface *iface)
 319 {
 320         char buf[64];
 321         int i;
 322
 323         prepare_qdisc_cmd(buf, sizeof(buf), iface->ifname, false, "root");
 324         qosify_run_cmd(buf, true);
 325
 326         for (i = 0; i < 6; i++) {
 327                 prepare_filter_cmd(buf, sizeof(buf), iface->ifname, QOSIFY_PRIO_BASE + i, false, false);
 328                 qosify_run_cmd(buf, true);
 329         }
 330
 331         prepare_filter_cmd(buf, sizeof(buf), iface->ifname, QOSIFY_PRIO_BASE, false, true);
 332         qosify_run_cmd(buf, true);
 333
 334         snprintf(buf, sizeof(buf), "ip link del '%s'", interface_ifb_name(iface));
 335         qosify_run_cmd(buf, true);
 336 }
 337
 338 static void
 339 interface_start(struct qosify_iface *iface)
 340 {
 341         struct ifreq ifr = {};
 342         bool eth;
 343
 344         if (!iface->ifname[0] || iface->active)
 345                 return;
 346
 347         ULOG_INFO("start interface %s\n", iface->ifname);
 348
 349         strncpy(ifr.ifr_name, iface->ifname, sizeof(ifr.ifr_name));
 350         if (ioctl(socket_fd, SIOCGIFHWADDR, &ifr) < 0) {
 351                 ULOG_ERR("ioctl(SIOCGIFHWADDR, %s) failed: %s\n", iface->ifname, strerror(errno));
 352                 return;
 353         }
 354
 355         eth = ifr.ifr_hwaddr.sa_family == ARPHRD_ETHER;
 356
 357         interface_clear_qdisc(iface);
 358         cmd_add_egress(iface, eth);
 359         cmd_add_ingress(iface, eth);
 360
 361         iface->active = true;
 362 }
 363
 364 static void
 365 interface_stop(struct qosify_iface *iface)
 366 {
 367         if (!iface->ifname[0] || !iface->active)
 368                 return;
 369
 370         ULOG_INFO("stop interface %s\n", iface->ifname);
 371         iface->active = false;
 372
 373         interface_clear_qdisc(iface);
 374 }
 375
 376 static void
 377 interface_set_config(struct qosify_iface *iface, struct blob_attr *config)
 378 {
 379         iface->config_data = blob_memdup(config);
 380         iface_config_set(iface, iface->config_data);
 381         interface_start(iface);
 382 }
 383
 384 static void
 385 interface_update_cb(struct vlist_tree *tree,
 386                     struct vlist_node *node_new, struct vlist_node *node_old)
 387 {
 388         struct qosify_iface *if_new = NULL, *if_old = NULL;
 389
 390         if (node_new)
 391                 if_new = container_of(node_new, struct qosify_iface, node);
 392         if (node_old)
 393                 if_old = container_of(node_old, struct qosify_iface, node);
 394
 395         if (if_new && if_old) {
 396                 if (!iface_config_equal(if_old, if_new)) {
 397                         interface_stop(if_old);
 398                         free(if_old->config_data);
 399                         interface_set_config(if_old, if_new->config_data);
 400                 }
 401
 402                 free(if_new);
 403                 return;
 404         }
 405
 406         if (if_old) {
 407                 interface_stop(if_old);
 408                 free(if_old->config_data);
 409                 free(if_old);
 410         }
 411
 412         if (if_new)
 413                 interface_set_config(if_new, if_new->config_data);
 414 }
 415
 416 static void
 417 interface_create(struct blob_attr *attr, bool device)
 418 {
 419         struct qosify_iface *iface;
 420         const char *name = blobmsg_name(attr);
 421         int name_len = strlen(name);
 422         char *name_buf;
 423
 424         if (strchr(name, '\''))
 425                 return;
 426
 427         if (name_len >= IFNAMSIZ)
 428                 return;
 429
 430         if (blobmsg_type(attr) != BLOBMSG_TYPE_TABLE)
 431                 return;
 432
 433         iface = calloc_a(sizeof(*iface), &name_buf, name_len + 1);
 434         strcpy(name_buf, blobmsg_name(attr));
 435         iface->config_data = attr;
 436         iface->device = device;
 437         vlist_add(device ? &devices : &interfaces, &iface->node, name_buf);
 438 }
 439
 440 void qosify_iface_config_update(struct blob_attr *ifaces, struct blob_attr *devs)
 441 {
 442         struct blob_attr *cur;
 443         int rem;
 444
 445         vlist_update(&devices);
 446         blobmsg_for_each_attr(cur, devs, rem)
 447                 interface_create(cur, true);
 448         vlist_flush(&devices);
 449
 450         vlist_update(&interfaces);
 451         blobmsg_for_each_attr(cur, ifaces, rem)
 452                 interface_create(cur, false);
 453         vlist_flush(&interfaces);
 454 }
 455
 456 static void
 457 qosify_iface_check_device(struct qosify_iface *iface)
 458 {
 459         const char *name = qosify_iface_name(iface);
 460         int ifindex;
 461
 462         ifindex = if_nametoindex(name);
 463         if (!ifindex) {
 464                 interface_stop(iface);
 465                 iface->ifname[0] = 0;
 466         } else {
 467                 snprintf(iface->ifname, sizeof(iface->ifname), "%s", name);
 468                 interface_start(iface);
 469         }
 470 }
 471
 472 static void
 473 qosify_iface_check_interface(struct qosify_iface *iface)
 474 {
 475         const char *name = qosify_iface_name(iface);
 476         char ifname[IFNAMSIZ];
 477
 478         if (qosify_ubus_check_interface(name, ifname, sizeof(ifname)) == 0) {
 479                 snprintf(iface->ifname, sizeof(iface->ifname), "%s", ifname);
 480                 interface_start(iface);
 481         } else {
 482                 interface_stop(iface);
 483                 iface->ifname[0] = 0;
 484         }
 485 }
 486
 487 static void qos_iface_check_cb(struct uloop_timeout *t)
 488 {
 489         struct qosify_iface *iface;
 490
 491         vlist_for_each_element(&devices, iface, node)
 492                 qosify_iface_check_device(iface);
 493         vlist_for_each_element(&interfaces, iface, node)
 494                 qosify_iface_check_interface(iface);
 495 }
 496
 497 void qosify_iface_check(void)
 498 {
 499         static struct uloop_timeout timer = {
 500                 .cb = qos_iface_check_cb,
 501         };
 502
 503         uloop_timeout_set(&timer, 10);
 504 }
 505
 506 static void
 507 __qosify_iface_status(struct blob_buf *b, struct qosify_iface *iface)
 508 {
 509         void *c;
 510
 511         c = blobmsg_open_table(b, qosify_iface_name(iface));
 512         blobmsg_add_u8(b, "active", iface->active);
 513         if (iface->ifname)
 514                 blobmsg_add_string(b, "ifname", iface->ifname);
 515         blobmsg_add_u8(b, "egress", iface->config.egress);
 516         blobmsg_add_u8(b, "ingress", iface->config.ingress);
 517         blobmsg_close_table(b, c);
 518
 519 }
 520
 521 void qosify_iface_status(struct blob_buf *b)
 522 {
 523         struct qosify_iface *iface;
 524         void *c;
 525
 526         c = blobmsg_open_table(b, "devices");
 527         vlist_for_each_element(&devices, iface, node)
 528                 __qosify_iface_status(b, iface);
 529         blobmsg_close_table(b, c);
 530
 531         c = blobmsg_open_table(b, "interfaces");
 532         vlist_for_each_element(&interfaces, iface, node)
 533                 __qosify_iface_status(b, iface);
 534         blobmsg_close_table(b, c);
 535 }
 536
 537 int qosify_iface_init(void)
 538 {
 539         socket_fd = socket(AF_UNIX, SOCK_DGRAM, 0);
 540         if (socket < 0)
 541                 return -1;
 542
 543         return 0;
 544 }
 545
 546 void qosify_iface_stop(void)
 547 {
 548         struct qosify_iface *iface;
 549
 550         vlist_for_each_element(&interfaces, iface, node)
 551                 interface_stop(iface);
 552         vlist_for_each_element(&devices, iface, node)
 553                 interface_stop(iface);
 554 }
 555