iprule.c

   1 /*
   2  * netifd - network interface daemon
   3  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   4  * Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
   5  * Copyright (C) 2018 Alexander Couzens <lynxis@fe80.eu>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2
   9  * as published by the Free Software Foundation
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16 #include <assert.h>
  17 #include <string.h>
  18 #include <stdlib.h>
  19 #include <stdio.h>
  20
  21 #include <arpa/inet.h>
  22
  23 #include "netifd.h"
  24 #include "device.h"
  25 #include "interface.h"
  26 #include "iprule.h"
  27 #include "proto.h"
  28 #include "ubus.h"
  29 #include "system.h"
  30
  31 struct vlist_tree iprules;
  32 static bool iprules_flushed = false;
  33 static unsigned int iprules_counter[2];
  34
  35 enum {
  36         RULE_INTERFACE_IN,
  37         RULE_INTERFACE_OUT,
  38         RULE_INVERT,
  39         RULE_SRC,
  40         RULE_DEST,
  41         RULE_PRIORITY,
  42         RULE_TOS,
  43         RULE_FWMARK,
  44         RULE_LOOKUP,
  45         RULE_ACTION,
  46         RULE_GOTO,
  47         RULE_SUP_PREFIXLEN,
  48         __RULE_MAX
  49 };
  50
  51 static const struct blobmsg_policy rule_attr[__RULE_MAX] = {
  52         [RULE_INTERFACE_IN] = { .name = "in", .type = BLOBMSG_TYPE_STRING },
  53         [RULE_INTERFACE_OUT] = { .name = "out", .type = BLOBMSG_TYPE_STRING },
  54         [RULE_INVERT] = { .name = "invert", .type = BLOBMSG_TYPE_BOOL },
  55         [RULE_SRC] = { .name = "src", .type = BLOBMSG_TYPE_STRING },
  56         [RULE_DEST] = { .name = "dest", .type = BLOBMSG_TYPE_STRING },
  57         [RULE_PRIORITY] = { .name = "priority", .type = BLOBMSG_TYPE_INT32 },
  58         [RULE_TOS] = { .name = "tos", .type = BLOBMSG_TYPE_INT32 },
  59         [RULE_FWMARK] = { .name = "mark", .type = BLOBMSG_TYPE_STRING },
  60         [RULE_LOOKUP] = { .name = "lookup", .type = BLOBMSG_TYPE_STRING },
  61         [RULE_SUP_PREFIXLEN] = { .name = "suppress_prefixlength", .type = BLOBMSG_TYPE_INT32 },
  62         [RULE_ACTION] = { .name = "action", .type = BLOBMSG_TYPE_STRING },
  63         [RULE_GOTO]   = { .name = "goto", .type = BLOBMSG_TYPE_INT32 },
  64 };
  65
  66 const struct uci_blob_param_list rule_attr_list = {
  67         .n_params = __RULE_MAX,
  68         .params = rule_attr,
  69 };
  70
  71 /* interface based rules are dynamic. */
  72 static bool rule_ready(struct iprule *rule) {
  73         if (rule->flags & IPRULE_OUT && rule->out_dev == NULL)
  74                 return false;
  75
  76         if (rule->flags & IPRULE_IN && rule->in_dev == NULL)
  77                 return false;
  78
  79         return true;
  80 }
  81
  82 static bool
  83 iprule_parse_mark(const char *mark, struct iprule *rule)
  84 {
  85         char *s, *e;
  86         unsigned int n;
  87
  88         if ((s = strchr(mark, '/')) != NULL)
  89                 *s++ = 0;
  90
  91         n = strtoul(mark, &e, 0);
  92
  93         if (e == mark || *e)
  94                 return false;
  95
  96         rule->fwmark = n;
  97         rule->flags |= IPRULE_FWMARK;
  98
  99         if (s) {
 100                 n = strtoul(s, &e, 0);
 101
 102                 if (e == s || *e)
 103                         return false;
 104
 105                 rule->fwmask = n;
 106                 rule->flags |= IPRULE_FWMASK;
 107         }
 108
 109         return true;
 110 }
 111
 112 /* called on interface changes of the incoming interface */
 113 static void rule_in_cb(
 114                 struct interface_user *dep,
 115                 struct interface *iface,
 116                 enum interface_event ev)
 117 {
 118         struct iprule *rule = container_of(dep, struct iprule, in_iface_user);
 119
 120         switch (ev) {
 121         case IFEV_UP:
 122                 if (!iface->l3_dev.dev)
 123                         break;
 124                 memcpy(rule->in_dev, iface->l3_dev.dev->ifname, sizeof(rule->in_dev));
 125                 if (rule_ready(rule))
 126                         system_add_iprule(rule);
 127                 break;
 128         case IFEV_DOWN:
 129         case IFEV_UP_FAILED:
 130         case IFEV_FREE:
 131                 if (rule_ready(rule))
 132                         system_del_iprule(rule);
 133                 rule->in_dev[0] = 0;
 134                 break;
 135         default:
 136                 break;
 137         }
 138 }
 139
 140 /* called on interface changes of the outgoing interface */
 141 static void rule_out_cb(
 142                 struct interface_user *dep,
 143                 struct interface *iface,
 144                 enum interface_event ev)
 145 {
 146         struct iprule *rule = container_of(dep, struct iprule, out_iface_user);
 147
 148         switch (ev) {
 149         case IFEV_UP:
 150                 if (!iface->l3_dev.dev)
 151                         break;
 152                 memcpy(rule->out_dev, iface->l3_dev.dev->ifname, sizeof(rule->out_dev));
 153                 if (rule_ready(rule))
 154                         system_add_iprule(rule);
 155                 break;
 156         case IFEV_DOWN:
 157         case IFEV_UP_FAILED:
 158         case IFEV_FREE:
 159                 if (rule_ready(rule))
 160                         system_del_iprule(rule);
 161                 rule->out_dev[0] = 0;
 162                 break;
 163         default:
 164                 break;
 165         }
 166 }
 167
 168 /* called on all interface events */
 169 static void generic_interface_cb(
 170                 struct interface_user *dep,
 171                 struct interface *iface,
 172                 enum interface_event ev)
 173 {
 174         struct iprule *rule;
 175
 176         if (ev != IFEV_CREATE)
 177                 return;
 178
 179         /* add new interfaces to rules */
 180         vlist_for_each_element(&iprules, rule, node) {
 181                 if (rule_ready(rule))
 182                         continue;
 183
 184                 if (!strcmp(rule->out_iface, iface->name)) {
 185                         assert(!rule->out_dev);
 186                         memcpy(rule->out_dev, iface->l3_dev.dev->ifname, sizeof(rule->out_dev));
 187                         interface_add_user(&rule->out_iface_user, iface);
 188                 }
 189
 190                 if (!strcmp(rule->in_iface, iface->name)) {
 191                         assert(!rule->in_dev);
 192                         memcpy(rule->in_dev, iface->l3_dev.dev->ifname, sizeof(rule->in_dev));
 193                         interface_add_user(&rule->in_iface_user, iface);
 194                 }
 195         }
 196 }
 197
 198 struct interface_user generic_listener = {
 199         .cb = generic_interface_cb
 200 };
 201
 202 void
 203 iprule_add(struct blob_attr *attr, bool v6)
 204 {
 205         struct blob_attr *tb[__RULE_MAX], *cur;
 206         struct iprule *rule;
 207         char *iface_name;
 208         int af = v6 ? AF_INET6 : AF_INET;
 209
 210         blobmsg_parse(rule_attr, __RULE_MAX, tb, blobmsg_data(attr), blobmsg_data_len(attr));
 211
 212         rule = calloc(1, sizeof(*rule));
 213         if (!rule)
 214                 return;
 215
 216         rule->flags = v6 ? IPRULE_INET6 : IPRULE_INET4;
 217         rule->order = iprules_counter[rule->flags]++;
 218
 219         if ((cur = tb[RULE_INVERT]) != NULL)
 220                 rule->invert = blobmsg_get_bool(cur);
 221
 222         if ((cur = tb[RULE_INTERFACE_IN]) != NULL) {
 223                 iface_name = calloc(1, strlen(blobmsg_data(cur)) + 1);
 224                 rule->in_iface = strcpy(iface_name, blobmsg_data(cur));
 225                 rule->in_iface_user.cb = &rule_in_cb;
 226                 rule->flags |= IPRULE_IN;
 227         }
 228
 229         if ((cur = tb[RULE_INTERFACE_OUT]) != NULL) {
 230                 iface_name = calloc(1, strlen(blobmsg_data(cur)) + 1);
 231                 rule->out_iface = strcpy(iface_name, blobmsg_data(cur));
 232                 rule->out_iface_user.cb = &rule_out_cb;
 233                 rule->flags |= IPRULE_OUT;
 234         }
 235
 236         if ((cur = tb[RULE_SRC]) != NULL) {
 237                 if (!parse_ip_and_netmask(af, blobmsg_data(cur), &rule->src_addr, &rule->src_mask)) {
 238                         DPRINTF("Failed to parse rule source: %s\n", (char *) blobmsg_data(cur));
 239                         goto error;
 240                 }
 241                 rule->flags |= IPRULE_SRC;
 242         }
 243
 244         if ((cur = tb[RULE_DEST]) != NULL) {
 245                 if (!parse_ip_and_netmask(af, blobmsg_data(cur), &rule->dest_addr, &rule->dest_mask)) {
 246                         DPRINTF("Failed to parse rule destination: %s\n", (char *) blobmsg_data(cur));
 247                         goto error;
 248                 }
 249                 rule->flags |= IPRULE_DEST;
 250         }
 251
 252         if ((cur = tb[RULE_PRIORITY]) != NULL) {
 253                 rule->priority = blobmsg_get_u32(cur);
 254                 rule->flags |= IPRULE_PRIORITY;
 255         }
 256
 257         if ((cur = tb[RULE_TOS]) != NULL) {
 258                 if ((rule->tos = blobmsg_get_u32(cur)) > 255) {
 259                         DPRINTF("Invalid TOS value: %u\n", blobmsg_get_u32(cur));
 260                         goto error;
 261                 }
 262                 rule->flags |= IPRULE_TOS;
 263         }
 264
 265         if ((cur = tb[RULE_FWMARK]) != NULL) {
 266                 if (!iprule_parse_mark(blobmsg_data(cur), rule)) {
 267                         DPRINTF("Failed to parse rule fwmark: %s\n", (char *) blobmsg_data(cur));
 268                         goto error;
 269                 }
 270                 /* flags set by iprule_parse_mark() */
 271         }
 272
 273         if ((cur = tb[RULE_LOOKUP]) != NULL) {
 274                 if (!system_resolve_rt_table(blobmsg_data(cur), &rule->lookup)) {
 275                         DPRINTF("Failed to parse rule lookup table: %s\n", (char *) blobmsg_data(cur));
 276                         goto error;
 277                 }
 278                 rule->flags |= IPRULE_LOOKUP;
 279         }
 280
 281         if ((cur = tb[RULE_SUP_PREFIXLEN]) != NULL) {
 282                 rule->sup_prefixlen = blobmsg_get_u32(cur);
 283                 rule->flags |= IPRULE_SUP_PREFIXLEN;
 284         }
 285
 286         if ((cur = tb[RULE_ACTION]) != NULL) {
 287                 if (!system_resolve_iprule_action(blobmsg_data(cur), &rule->action)) {
 288                         DPRINTF("Failed to parse rule action: %s\n", (char *) blobmsg_data(cur));
 289                         goto error;
 290                 }
 291                 rule->flags |= IPRULE_ACTION;
 292         }
 293
 294         if ((cur = tb[RULE_GOTO]) != NULL) {
 295                 rule->gotoid = blobmsg_get_u32(cur);
 296                 rule->flags |= IPRULE_GOTO;
 297         }
 298
 299         vlist_add(&iprules, &rule->node, &rule->flags);
 300         return;
 301
 302 error:
 303         free(rule);
 304 }
 305
 306 void
 307 iprule_update_start(void)
 308 {
 309         if (!iprules_flushed) {
 310                 system_flush_iprules();
 311                 iprules_flushed = true;
 312         }
 313
 314         iprules_counter[0] = 1;
 315         iprules_counter[1] = 1;
 316         vlist_update(&iprules);
 317 }
 318
 319 void
 320 iprule_update_complete(void)
 321 {
 322         vlist_flush(&iprules);
 323 }
 324
 325
 326 static int
 327 rule_cmp(const void *k1, const void *k2, void *ptr)
 328 {
 329         return memcmp(k1, k2, sizeof(struct iprule)-offsetof(struct iprule, flags));
 330 }
 331
 332 static void deregister_interfaces(struct iprule *rule)
 333 {
 334         if (rule->flags & IPRULE_IN && rule->in_iface_user.iface)
 335                 interface_remove_user(&rule->in_iface_user);
 336
 337         if (rule->flags & IPRULE_OUT && rule->out_iface_user.iface)
 338                 interface_remove_user(&rule->out_iface_user);
 339 }
 340
 341 static void register_interfaces(struct iprule *rule)
 342 {
 343         struct interface *iface, *tmp;
 344
 345         if (rule->flags & IPRULE_IN) {
 346                 tmp = vlist_find(&interfaces, rule->in_iface, iface, node);
 347                 if (tmp)
 348                         interface_add_user(&rule->in_iface_user, tmp);
 349         }
 350         if (rule->flags & IPRULE_OUT) {
 351                 tmp = vlist_find(&interfaces, rule->out_iface, iface, node);
 352                 if (tmp)
 353                         interface_add_user(&rule->out_iface_user, tmp);
 354         }
 355 }
 356
 357 static void
 358 iprule_update_rule(struct vlist_tree *tree,
 359                         struct vlist_node *node_new, struct vlist_node *node_old)
 360 {
 361         struct iprule *rule_old, *rule_new;
 362
 363         rule_old = container_of(node_old, struct iprule, node);
 364         rule_new = container_of(node_new, struct iprule, node);
 365
 366         if (node_old) {
 367                 if (rule_ready(rule_old))
 368                         system_del_iprule(rule_old);
 369
 370                 if (rule_old->flags & (IPRULE_IN | IPRULE_OUT))
 371                         deregister_interfaces(rule_old);
 372
 373                 if (rule_old->in_iface)
 374                         free(rule_old->in_iface);
 375
 376                 if (rule_old->out_iface)
 377                         free(rule_old->out_iface);
 378
 379                 free(rule_old);
 380         }
 381
 382         if (node_new) {
 383                 /* interface based rules calls system_add_iprule over the event cb */
 384                 if (rule_new->flags & (IPRULE_IN | IPRULE_OUT)) {
 385                         register_interfaces(rule_new);
 386                 } else {
 387                         system_add_iprule(rule_new);
 388                 }
 389         }
 390 }
 391
 392 static void __init
 393 iprule_init_list(void)
 394 {
 395         vlist_init(&iprules, rule_cmp, iprule_update_rule);
 396         interface_add_user(&generic_listener, NULL);
 397 }