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 <string.h>
  17 #include <stdlib.h>
  18 #include <stdio.h>
  19
  20 #include <arpa/inet.h>
  21
  22 #include "netifd.h"
  23 #include "device.h"
  24 #include "interface.h"
  25 #include "iprule.h"
  26 #include "proto.h"
  27 #include "ubus.h"
  28 #include "system.h"
  29
  30 struct vlist_tree iprules;
  31 static bool iprules_flushed = false;
  32 static unsigned int iprules_counter[2];
  33
  34 enum {
  35         RULE_INTERFACE_IN,
  36         RULE_INTERFACE_OUT,
  37         RULE_INVERT,
  38         RULE_SRC,
  39         RULE_DEST,
  40         RULE_PRIORITY,
  41         RULE_TOS,
  42         RULE_FWMARK,
  43         RULE_LOOKUP,
  44         RULE_ACTION,
  45         RULE_GOTO,
  46         RULE_SUP_PREFIXLEN,
  47         __RULE_MAX
  48 };
  49
  50 static const struct blobmsg_policy rule_attr[__RULE_MAX] = {
  51         [RULE_INTERFACE_IN] = { .name = "in", .type = BLOBMSG_TYPE_STRING },
  52         [RULE_INTERFACE_OUT] = { .name = "out", .type = BLOBMSG_TYPE_STRING },
  53         [RULE_INVERT] = { .name = "invert", .type = BLOBMSG_TYPE_BOOL },
  54         [RULE_SRC] = { .name = "src", .type = BLOBMSG_TYPE_STRING },
  55         [RULE_DEST] = { .name = "dest", .type = BLOBMSG_TYPE_STRING },
  56         [RULE_PRIORITY] = { .name = "priority", .type = BLOBMSG_TYPE_INT32 },
  57         [RULE_TOS] = { .name = "tos", .type = BLOBMSG_TYPE_INT32 },
  58         [RULE_FWMARK] = { .name = "mark", .type = BLOBMSG_TYPE_STRING },
  59         [RULE_LOOKUP] = { .name = "lookup", .type = BLOBMSG_TYPE_STRING },
  60         [RULE_SUP_PREFIXLEN] = { .name = "suppress_prefixlength", .type = BLOBMSG_TYPE_INT32 },
  61         [RULE_ACTION] = { .name = "action", .type = BLOBMSG_TYPE_STRING },
  62         [RULE_GOTO]   = { .name = "goto", .type = BLOBMSG_TYPE_INT32 },
  63 };
  64
  65 const struct uci_blob_param_list rule_attr_list = {
  66         .n_params = __RULE_MAX,
  67         .params = rule_attr,
  68 };
  69
  70 /* interface based rules are dynamic. */
  71 static bool
  72 rule_ready(struct iprule *rule)
  73 {
  74         if (rule->flags & IPRULE_OUT && !rule->out_dev[0])
  75                 return false;
  76
  77         if (rule->flags & IPRULE_IN && !rule->in_dev[0])
  78                 return false;
  79
  80         return true;
  81 }
  82
  83 static bool
  84 iprule_parse_mark(const char *mark, struct iprule *rule)
  85 {
  86         char *s, *e;
  87         unsigned int n;
  88
  89         if ((s = strchr(mark, '/')) != NULL)
  90                 *s++ = 0;
  91
  92         n = strtoul(mark, &e, 0);
  93
  94         if (e == mark || *e)
  95                 return false;
  96
  97         rule->fwmark = n;
  98         rule->flags |= IPRULE_FWMARK;
  99
 100         if (s) {
 101                 n = strtoul(s, &e, 0);
 102
 103                 if (e == s || *e)
 104                         return false;
 105
 106                 rule->fwmask = n;
 107                 rule->flags |= IPRULE_FWMASK;
 108         }
 109
 110         return true;
 111 }
 112
 113 /* called on interface changes of the incoming interface */
 114 static void
 115 rule_in_cb(struct interface_user *dep, struct interface *iface, enum interface_event ev)
 116 {
 117         struct iprule *rule = container_of(dep, struct iprule, in_iface_user);
 118
 119         switch (ev) {
 120         case IFEV_UP:
 121                 if (!iface->l3_dev.dev)
 122                         break;
 123
 124                 strcpy(rule->in_dev, iface->l3_dev.dev->ifname);
 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
 134                 rule->in_dev[0] = 0;
 135                 break;
 136         default:
 137                 break;
 138         }
 139 }
 140
 141 /* called on interface changes of the outgoing interface */
 142 static void
 143 rule_out_cb(struct interface_user *dep, struct interface *iface, enum interface_event ev)
 144 {
 145         struct iprule *rule = container_of(dep, struct iprule, out_iface_user);
 146
 147         switch (ev) {
 148         case IFEV_UP:
 149                 if (!iface->l3_dev.dev)
 150                         break;
 151
 152                 strcpy(rule->out_dev, iface->l3_dev.dev->ifname);
 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
 162                 rule->out_dev[0] = 0;
 163                 break;
 164         default:
 165                 break;
 166         }
 167 }
 168
 169 /* called on all interface events */
 170 static void
 171 generic_interface_cb(struct interface_user *dep,
 172                         struct interface *iface, 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 ((rule->flags & IPRULE_OUT) && !strcmp(rule->out_iface, iface->name))
 185                         interface_add_user(&rule->out_iface_user, iface);
 186
 187                 if ((rule->flags & IPRULE_IN) && !strcmp(rule->in_iface, iface->name))
 188                         interface_add_user(&rule->in_iface_user, iface);
 189         }
 190 }
 191
 192 struct interface_user generic_listener = {
 193         .cb = generic_interface_cb
 194 };
 195
 196 void
 197 iprule_add(struct blob_attr *attr, bool v6)
 198 {
 199         struct blob_attr *tb[__RULE_MAX], *cur;
 200         struct iprule *rule;
 201         char *iface_name;
 202         int af = v6 ? AF_INET6 : AF_INET;
 203
 204         blobmsg_parse(rule_attr, __RULE_MAX, tb, blobmsg_data(attr), blobmsg_data_len(attr));
 205
 206         rule = calloc(1, sizeof(*rule));
 207         if (!rule)
 208                 return;
 209
 210         rule->flags = v6 ? IPRULE_INET6 : IPRULE_INET4;
 211         rule->order = iprules_counter[rule->flags]++;
 212
 213         if ((cur = tb[RULE_INVERT]) != NULL)
 214                 rule->invert = blobmsg_get_bool(cur);
 215
 216         if ((cur = tb[RULE_INTERFACE_IN]) != NULL) {
 217                 iface_name = calloc(1, strlen(blobmsg_data(cur)) + 1);
 218                 rule->in_iface = strcpy(iface_name, blobmsg_data(cur));
 219                 rule->in_iface_user.cb = &rule_in_cb;
 220                 rule->flags |= IPRULE_IN;
 221         }
 222
 223         if ((cur = tb[RULE_INTERFACE_OUT]) != NULL) {
 224                 iface_name = calloc(1, strlen(blobmsg_data(cur)) + 1);
 225                 rule->out_iface = strcpy(iface_name, blobmsg_data(cur));
 226                 rule->out_iface_user.cb = &rule_out_cb;
 227                 rule->flags |= IPRULE_OUT;
 228         }
 229
 230         if ((cur = tb[RULE_SRC]) != NULL) {
 231                 if (!parse_ip_and_netmask(af, blobmsg_data(cur), &rule->src_addr, &rule->src_mask)) {
 232                         DPRINTF("Failed to parse rule source: %s\n", (char *) blobmsg_data(cur));
 233                         goto error;
 234                 }
 235                 rule->flags |= IPRULE_SRC;
 236         }
 237
 238         if ((cur = tb[RULE_DEST]) != NULL) {
 239                 if (!parse_ip_and_netmask(af, blobmsg_data(cur), &rule->dest_addr, &rule->dest_mask)) {
 240                         DPRINTF("Failed to parse rule destination: %s\n", (char *) blobmsg_data(cur));
 241                         goto error;
 242                 }
 243                 rule->flags |= IPRULE_DEST;
 244         }
 245
 246         if ((cur = tb[RULE_PRIORITY]) != NULL) {
 247                 rule->priority = blobmsg_get_u32(cur);
 248                 rule->flags |= IPRULE_PRIORITY;
 249         }
 250
 251         if ((cur = tb[RULE_TOS]) != NULL) {
 252                 if ((rule->tos = blobmsg_get_u32(cur)) > 255) {
 253                         DPRINTF("Invalid TOS value: %u\n", blobmsg_get_u32(cur));
 254                         goto error;
 255                 }
 256                 rule->flags |= IPRULE_TOS;
 257         }
 258
 259         if ((cur = tb[RULE_FWMARK]) != NULL) {
 260                 if (!iprule_parse_mark(blobmsg_data(cur), rule)) {
 261                         DPRINTF("Failed to parse rule fwmark: %s\n", (char *) blobmsg_data(cur));
 262                         goto error;
 263                 }
 264                 /* flags set by iprule_parse_mark() */
 265         }
 266
 267         if ((cur = tb[RULE_LOOKUP]) != NULL) {
 268                 if (!system_resolve_rt_table(blobmsg_data(cur), &rule->lookup)) {
 269                         DPRINTF("Failed to parse rule lookup table: %s\n", (char *) blobmsg_data(cur));
 270                         goto error;
 271                 }
 272                 rule->flags |= IPRULE_LOOKUP;
 273         }
 274
 275         if ((cur = tb[RULE_SUP_PREFIXLEN]) != NULL) {
 276                 rule->sup_prefixlen = blobmsg_get_u32(cur);
 277                 rule->flags |= IPRULE_SUP_PREFIXLEN;
 278         }
 279
 280         if ((cur = tb[RULE_ACTION]) != NULL) {
 281                 if (!system_resolve_iprule_action(blobmsg_data(cur), &rule->action)) {
 282                         DPRINTF("Failed to parse rule action: %s\n", (char *) blobmsg_data(cur));
 283                         goto error;
 284                 }
 285                 rule->flags |= IPRULE_ACTION;
 286         }
 287
 288         if ((cur = tb[RULE_GOTO]) != NULL) {
 289                 rule->gotoid = blobmsg_get_u32(cur);
 290                 rule->flags |= IPRULE_GOTO;
 291         }
 292
 293         vlist_add(&iprules, &rule->node, rule);
 294         return;
 295
 296 error:
 297         free(rule);
 298 }
 299
 300 void
 301 iprule_update_start(void)
 302 {
 303         if (!iprules_flushed) {
 304                 system_flush_iprules();
 305                 iprules_flushed = true;
 306         }
 307
 308         iprules_counter[0] = 1;
 309         iprules_counter[1] = 1;
 310         vlist_update(&iprules);
 311 }
 312
 313 void
 314 iprule_update_complete(void)
 315 {
 316         vlist_flush(&iprules);
 317 }
 318
 319
 320 static int
 321 rule_cmp(const void *k1, const void *k2, void *ptr)
 322 {
 323         const struct iprule *r1 = k1, *r2 = k2;
 324         int ret;
 325
 326         /* First compare the interface names */
 327         if (r1->flags & IPRULE_IN || r2->flags & IPRULE_IN) {
 328                 char *str1 = r1->flags & IPRULE_IN ? r1->in_iface : "";
 329                 char *str2 = r2->flags & IPRULE_IN ? r2->in_iface : "";
 330
 331                 ret = strcmp(str1, str2);
 332                 if (ret)
 333                         return ret;
 334         }
 335
 336         if (r1->flags & IPRULE_OUT || r2->flags & IPRULE_OUT) {
 337                 char *str1 = r1->flags & IPRULE_OUT ? r1->out_iface : "";
 338                 char *str2 = r2->flags & IPRULE_OUT ? r2->out_iface : "";
 339
 340                 ret = strcmp(str1, str2);
 341                 if (ret)
 342                         return ret;
 343         }
 344
 345         /* Next compare everything after the flags field */
 346         return memcmp(k1 + offsetof(struct iprule, flags),
 347                       k2 + offsetof(struct iprule, flags),
 348                       sizeof(struct iprule) - offsetof(struct iprule, flags));
 349 }
 350
 351 static void deregister_interfaces(struct iprule *rule)
 352 {
 353         if (rule->flags & IPRULE_IN && rule->in_iface_user.iface)
 354                 interface_remove_user(&rule->in_iface_user);
 355
 356         if (rule->flags & IPRULE_OUT && rule->out_iface_user.iface)
 357                 interface_remove_user(&rule->out_iface_user);
 358 }
 359
 360 static void register_interfaces(struct iprule *rule)
 361 {
 362         struct interface *iface, *tmp;
 363
 364         if (rule->flags & IPRULE_IN) {
 365                 tmp = vlist_find(&interfaces, rule->in_iface, iface, node);
 366                 if (tmp)
 367                         interface_add_user(&rule->in_iface_user, tmp);
 368         }
 369         if (rule->flags & IPRULE_OUT) {
 370                 tmp = vlist_find(&interfaces, rule->out_iface, iface, node);
 371                 if (tmp)
 372                         interface_add_user(&rule->out_iface_user, tmp);
 373         }
 374 }
 375
 376 static void
 377 iprule_update_rule(struct vlist_tree *tree,
 378                         struct vlist_node *node_new, struct vlist_node *node_old)
 379 {
 380         struct iprule *rule_old, *rule_new;
 381
 382         rule_old = container_of(node_old, struct iprule, node);
 383         rule_new = container_of(node_new, struct iprule, node);
 384
 385         if (node_old) {
 386                 if (rule_ready(rule_old))
 387                         system_del_iprule(rule_old);
 388
 389                 if (rule_old->flags & (IPRULE_IN | IPRULE_OUT))
 390                         deregister_interfaces(rule_old);
 391
 392                 if (rule_old->in_iface)
 393                         free(rule_old->in_iface);
 394
 395                 if (rule_old->out_iface)
 396                         free(rule_old->out_iface);
 397
 398                 free(rule_old);
 399         }
 400
 401         if (node_new) {
 402                 /* interface based rules calls system_add_iprule over the event cb */
 403                 if (rule_new->flags & (IPRULE_IN | IPRULE_OUT)) {
 404                         register_interfaces(rule_new);
 405                 } else {
 406                         system_add_iprule(rule_new);
 407                 }
 408         }
 409 }
 410
 411 static void __init
 412 iprule_init_list(void)
 413 {
 414         vlist_init(&iprules, rule_cmp, iprule_update_rule);
 415         interface_add_user(&generic_listener, NULL);
 416 }