1 /** @file
2  @brief IPv6 data handler
3 
4  This is not to be included by the application.
5  */
6 
7 /*
8  * Copyright (c) 2016 Intel Corporation
9  *
10  * SPDX-License-Identifier: Apache-2.0
11  */
12 
13 #ifndef __IPV6_H
14 #define __IPV6_H
15 
16 #include <zephyr/types.h>
17 
18 #include <zephyr/net/net_ip.h>
19 #include <zephyr/net/net_pkt.h>
20 #include <zephyr/net/net_if.h>
21 #include <zephyr/net/net_context.h>
22 
23 #include "icmpv6.h"
24 #include "nbr.h"
25 
26 #define NET_IPV6_ND_HOP_LIMIT 255
27 #define NET_IPV6_ND_INFINITE_LIFETIME 0xFFFFFFFF
28 
29 #define NET_IPV6_DEFAULT_PREFIX_LEN 64
30 
31 #define NET_MAX_RS_COUNT 3
32 
33 #define NET_IPV6_DSCP_MASK 0xFC
34 #define NET_IPV6_DSCP_OFFSET 2
35 #define NET_IPV6_ECN_MASK 0x03
36 
37 /**
38  * @brief Bitmaps for IPv6 extension header processing
39  *
40  * When processing extension headers, we record which one we have seen.
41  * This is done as the network packet cannot have twice the same header,
42  * except for destination option.
43  * This information is stored in bitfield variable.
44  * The order of the bitmap is the order recommended in RFC 2460.
45  */
46 #define NET_IPV6_EXT_HDR_BITMAP_HBHO   0x01
47 #define NET_IPV6_EXT_HDR_BITMAP_DESTO1 0x02
48 #define NET_IPV6_EXT_HDR_BITMAP_ROUTING        0x04
49 #define NET_IPV6_EXT_HDR_BITMAP_FRAG   0x08
50 #define NET_IPV6_EXT_HDR_BITMAP_AH     0x10
51 #define NET_IPV6_EXT_HDR_BITMAP_ESP    0x20
52 #define NET_IPV6_EXT_HDR_BITMAP_DESTO2 0x40
53 
54 /**
55  * @brief Destination and Hop By Hop extension headers option types
56  */
57 #define NET_IPV6_EXT_HDR_OPT_PAD1  0
58 #define NET_IPV6_EXT_HDR_OPT_PADN  1
59 #define NET_IPV6_EXT_HDR_OPT_RPL   0x63
60 
61 /**
62  * @brief Multicast Listener Record v2 record types.
63  */
64 #define NET_IPV6_MLDv2_MODE_IS_INCLUDE        1
65 #define NET_IPV6_MLDv2_MODE_IS_EXCLUDE        2
66 #define NET_IPV6_MLDv2_CHANGE_TO_INCLUDE_MODE 3
67 #define NET_IPV6_MLDv2_CHANGE_TO_EXCLUDE_MODE 4
68 #define NET_IPV6_MLDv2_ALLOW_NEW_SOURCES      5
69 #define NET_IPV6_MLDv2_BLOCK_OLD_SOURCES      6
70 
71 /* State of the neighbor */
72 enum net_ipv6_nbr_state {
73 	NET_IPV6_NBR_STATE_INCOMPLETE,
74 	NET_IPV6_NBR_STATE_REACHABLE,
75 	NET_IPV6_NBR_STATE_STALE,
76 	NET_IPV6_NBR_STATE_DELAY,
77 	NET_IPV6_NBR_STATE_PROBE,
78 	NET_IPV6_NBR_STATE_STATIC,
79 };
80 
81 const char *net_ipv6_nbr_state2str(enum net_ipv6_nbr_state state);
82 
83 /**
84  * @brief IPv6 neighbor information.
85  */
86 struct net_ipv6_nbr_data {
87 	/** Any pending packet waiting ND to finish. */
88 	struct net_pkt *pending;
89 
90 	/** IPv6 address. */
91 	struct in6_addr addr;
92 
93 	/** Reachable timer. */
94 	int64_t reachable;
95 
96 	/** Reachable timeout */
97 	int32_t reachable_timeout;
98 
99 	/** Neighbor Solicitation reply timer */
100 	int64_t send_ns;
101 
102 	/** State of the neighbor discovery */
103 	enum net_ipv6_nbr_state state;
104 
105 	/** Link metric for the neighbor */
106 	uint16_t link_metric;
107 
108 	/** How many times we have sent NS */
109 	uint8_t ns_count;
110 
111 	/** Is the neighbor a router */
112 	bool is_router;
113 
114 #if defined(CONFIG_NET_IPV6_NBR_CACHE) || defined(CONFIG_NET_IPV6_ND)
115 	/** Stale counter used to removed oldest nbr in STALE state,
116 	 *  when table is full.
117 	 */
118 	uint32_t stale_counter;
119 #endif
120 };
121 
net_ipv6_nbr_data(struct net_nbr * nbr)122 static inline struct net_ipv6_nbr_data *net_ipv6_nbr_data(struct net_nbr *nbr)
123 {
124 	return (struct net_ipv6_nbr_data *)nbr->data;
125 }
126 
127 #if defined(CONFIG_NET_IPV6_DAD)
128 int net_ipv6_start_dad(struct net_if *iface, struct net_if_addr *ifaddr);
129 #endif
130 
131 int net_ipv6_send_ns(struct net_if *iface, struct net_pkt *pending,
132 		     const struct in6_addr *src, const struct in6_addr *dst,
133 		     const struct in6_addr *tgt, bool is_my_address);
134 
135 int net_ipv6_send_rs(struct net_if *iface);
136 int net_ipv6_start_rs(struct net_if *iface);
137 
138 int net_ipv6_send_na(struct net_if *iface, const struct in6_addr *src,
139 		     const struct in6_addr *dst, const struct in6_addr *tgt,
140 		     uint8_t flags);
141 
142 
net_ipv6_is_nexthdr_upper_layer(uint8_t nexthdr)143 static inline bool net_ipv6_is_nexthdr_upper_layer(uint8_t nexthdr)
144 {
145 	return (nexthdr == IPPROTO_ICMPV6 || nexthdr == IPPROTO_UDP ||
146 		nexthdr == IPPROTO_TCP ||
147 		(IS_ENABLED(CONFIG_NET_L2_VIRTUAL) &&
148 		 ((nexthdr == IPPROTO_IPV6) || (nexthdr == IPPROTO_IPIP))));
149 }
150 
151 /**
152  * @brief Create IPv6 packet in provided net_pkt.
153  *
154  * @param pkt Network packet
155  * @param src Source IPv6 address
156  * @param dst Destination IPv6 address
157  *
158  * @return 0 on success, negative errno otherwise.
159  */
160 #if defined(CONFIG_NET_NATIVE_IPV6)
161 int net_ipv6_create(struct net_pkt *pkt,
162 		    const struct in6_addr *src,
163 		    const struct in6_addr *dst);
164 #else
net_ipv6_create(struct net_pkt * pkt,const struct in6_addr * src,const struct in6_addr * dst)165 static inline int net_ipv6_create(struct net_pkt *pkt,
166 				  const struct in6_addr *src,
167 				  const struct in6_addr *dst)
168 {
169 	ARG_UNUSED(pkt);
170 	ARG_UNUSED(src);
171 	ARG_UNUSED(dst);
172 
173 	return -ENOTSUP;
174 }
175 #endif
176 
177 /**
178  * @brief Finalize IPv6 packet. It should be called right before
179  * sending the packet and after all the data has been added into
180  * the packet. This function will set the length of the
181  * packet and calculate the higher protocol checksum if needed.
182  *
183  * @param pkt Network packet
184  * @param next_header_proto Protocol type of the next header after IPv6 header.
185  *
186  * @return 0 on success, negative errno otherwise.
187  */
188 #if defined(CONFIG_NET_NATIVE_IPV6)
189 int net_ipv6_finalize(struct net_pkt *pkt, uint8_t next_header_proto);
190 #else
net_ipv6_finalize(struct net_pkt * pkt,uint8_t next_header_proto)191 static inline int net_ipv6_finalize(struct net_pkt *pkt,
192 				    uint8_t next_header_proto)
193 {
194 	ARG_UNUSED(pkt);
195 	ARG_UNUSED(next_header_proto);
196 
197 	return -ENOTSUP;
198 }
199 #endif
200 
201 /**
202  * @brief Join a given multicast group.
203  *
204  * @param iface Network interface where join message is sent
205  * @param addr Multicast group to join
206  *
207  * @return Return 0 if joining was done, <0 otherwise.
208  */
209 #if defined(CONFIG_NET_IPV6_MLD)
210 int net_ipv6_mld_join(struct net_if *iface, const struct in6_addr *addr);
211 #else
212 static inline int
net_ipv6_mld_join(struct net_if * iface,const struct in6_addr * addr)213 net_ipv6_mld_join(struct net_if *iface, const struct in6_addr *addr)
214 {
215 	ARG_UNUSED(iface);
216 	ARG_UNUSED(addr);
217 
218 	return -ENOTSUP;
219 }
220 #endif /* CONFIG_NET_IPV6_MLD */
221 
222 /**
223  * @brief Leave a given multicast group.
224  *
225  * @param iface Network interface where leave message is sent
226  * @param addr Multicast group to leave
227  *
228  * @return Return 0 if leaving is done, <0 otherwise.
229  */
230 #if defined(CONFIG_NET_IPV6_MLD)
231 int net_ipv6_mld_leave(struct net_if *iface, const struct in6_addr *addr);
232 #else
233 static inline int
net_ipv6_mld_leave(struct net_if * iface,const struct in6_addr * addr)234 net_ipv6_mld_leave(struct net_if *iface, const struct in6_addr *addr)
235 {
236 	ARG_UNUSED(iface);
237 	ARG_UNUSED(addr);
238 
239 	return -ENOTSUP;
240 }
241 #endif /* CONFIG_NET_IPV6_MLD */
242 
243 /**
244  * @typedef net_nbr_cb_t
245  * @brief Callback used while iterating over neighbors.
246  *
247  * @param nbr A valid pointer on current neighbor.
248  * @param user_data A valid pointer on some user data or NULL
249  */
250 typedef void (*net_nbr_cb_t)(struct net_nbr *nbr, void *user_data);
251 
252 /**
253  * @brief Make sure the link layer address is set according to
254  * destination address. If the ll address is not yet known, then
255  * start neighbor discovery to find it out. If ND needs to be done
256  * then the returned packet is the Neighbor Solicitation message
257  * and the original message is sent after Neighbor Advertisement
258  * message is received.
259  *
260  * @param pkt Network packet
261  *
262  * @return Return a verdict.
263  */
264 #if defined(CONFIG_NET_IPV6_NBR_CACHE) && defined(CONFIG_NET_NATIVE_IPV6)
265 enum net_verdict net_ipv6_prepare_for_send(struct net_pkt *pkt);
266 #else
net_ipv6_prepare_for_send(struct net_pkt * pkt)267 static inline enum net_verdict net_ipv6_prepare_for_send(struct net_pkt *pkt)
268 {
269 	return NET_OK;
270 }
271 #endif
272 
273 /**
274  * @brief Look for a neighbor from it's address on an iface
275  *
276  * @param iface A valid pointer on a network interface
277  * @param addr The IPv6 address to match
278  *
279  * @return A valid pointer on a neighbor on success, NULL otherwise
280  */
281 #if defined(CONFIG_NET_IPV6_NBR_CACHE) && defined(CONFIG_NET_NATIVE_IPV6)
282 struct net_nbr *net_ipv6_nbr_lookup(struct net_if *iface,
283 				    struct in6_addr *addr);
284 #else
net_ipv6_nbr_lookup(struct net_if * iface,struct in6_addr * addr)285 static inline struct net_nbr *net_ipv6_nbr_lookup(struct net_if *iface,
286 						  struct in6_addr *addr)
287 {
288 	return NULL;
289 }
290 #endif
291 
292 /**
293  * @brief Get neighbor from its index.
294  *
295  * @param iface Network interface to match. If NULL, then use
296  * whatever interface there is configured for the neighbor address.
297  * @param idx Index of the link layer address in the address array
298  *
299  * @return A valid pointer on a neighbor on success, NULL otherwise
300  */
301 struct net_nbr *net_ipv6_get_nbr(struct net_if *iface, uint8_t idx);
302 
303 /**
304  * @brief Look for a neighbor from it's link local address index
305  *
306  * @param iface Network interface to match. If NULL, then use
307  * whatever interface there is configured for the neighbor address.
308  * @param idx Index of the link layer address in the address array
309  *
310  * @return A valid pointer on a neighbor on success, NULL otherwise
311  */
312 #if defined(CONFIG_NET_IPV6_NBR_CACHE) && defined(CONFIG_NET_NATIVE_IPV6)
313 struct in6_addr *net_ipv6_nbr_lookup_by_index(struct net_if *iface,
314 					      uint8_t idx);
315 #else
316 static inline
net_ipv6_nbr_lookup_by_index(struct net_if * iface,uint8_t idx)317 struct in6_addr *net_ipv6_nbr_lookup_by_index(struct net_if *iface,
318 					      uint8_t idx)
319 {
320 	return NULL;
321 }
322 #endif
323 
324 /**
325  * @brief Add a neighbor to neighbor cache
326  *
327  * Add a neighbor to the cache after performing a lookup and in case
328  * there exists an entry in the cache update its state and lladdr.
329  *
330  * @param iface A valid pointer on a network interface
331  * @param addr Neighbor IPv6 address
332  * @param lladdr Neighbor link layer address
333  * @param is_router Set to true if the neighbor is a router, false
334  * otherwise
335  * @param state Initial state of the neighbor entry in the cache
336  *
337  * @return A valid pointer on a neighbor on success, NULL otherwise
338  */
339 #if defined(CONFIG_NET_IPV6_NBR_CACHE) && defined(CONFIG_NET_NATIVE_IPV6)
340 struct net_nbr *net_ipv6_nbr_add(struct net_if *iface,
341 				 const struct in6_addr *addr,
342 				 const struct net_linkaddr *lladdr,
343 				 bool is_router,
344 				 enum net_ipv6_nbr_state state);
345 #else
net_ipv6_nbr_add(struct net_if * iface,const struct in6_addr * addr,const struct net_linkaddr * lladdr,bool is_router,enum net_ipv6_nbr_state state)346 static inline struct net_nbr *net_ipv6_nbr_add(struct net_if *iface,
347 					       const struct in6_addr *addr,
348 					       const struct net_linkaddr *lladdr,
349 					       bool is_router,
350 					       enum net_ipv6_nbr_state state)
351 {
352 	return NULL;
353 }
354 #endif
355 
356 /**
357  * @brief Remove a neighbor from neighbor cache.
358  *
359  * @param iface A valid pointer on a network interface
360  * @param addr Neighbor IPv6 address
361  *
362  * @return True if neighbor could be removed, False otherwise
363  */
364 #if defined(CONFIG_NET_IPV6_NBR_CACHE) && defined(CONFIG_NET_NATIVE_IPV6)
365 bool net_ipv6_nbr_rm(struct net_if *iface, struct in6_addr *addr);
366 #else
net_ipv6_nbr_rm(struct net_if * iface,struct in6_addr * addr)367 static inline bool net_ipv6_nbr_rm(struct net_if *iface, struct in6_addr *addr)
368 {
369 	return true;
370 }
371 #endif
372 
373 /**
374  * @brief Go through all the neighbors and call callback for each of them.
375  *
376  * @param cb User supplied callback function to call.
377  * @param user_data User specified data.
378  */
379 #if defined(CONFIG_NET_IPV6_NBR_CACHE) && defined(CONFIG_NET_NATIVE_IPV6)
380 void net_ipv6_nbr_foreach(net_nbr_cb_t cb, void *user_data);
381 #else /* CONFIG_NET_IPV6_NBR_CACHE */
net_ipv6_nbr_foreach(net_nbr_cb_t cb,void * user_data)382 static inline void net_ipv6_nbr_foreach(net_nbr_cb_t cb, void *user_data)
383 {
384 	return;
385 }
386 #endif /* CONFIG_NET_IPV6_NBR_CACHE */
387 
388 /**
389  * @brief Set the neighbor reachable timer.
390  *
391  * @param iface A valid pointer on a network interface
392  * @param nbr Neighbor struct pointer
393  */
394 #if defined(CONFIG_NET_IPV6_ND) && defined(CONFIG_NET_NATIVE_IPV6)
395 void net_ipv6_nbr_set_reachable_timer(struct net_if *iface,
396 				      struct net_nbr *nbr);
397 
398 #else /* CONFIG_NET_IPV6_ND */
net_ipv6_nbr_set_reachable_timer(struct net_if * iface,struct net_nbr * nbr)399 static inline void net_ipv6_nbr_set_reachable_timer(struct net_if *iface,
400 						    struct net_nbr *nbr)
401 {
402 }
403 #endif
404 
405 #if defined(CONFIG_NET_IPV6_FRAGMENT)
406 /** Store pending IPv6 fragment information that is needed for reassembly. */
407 struct net_ipv6_reassembly {
408 	/** IPv6 source address of the fragment */
409 	struct in6_addr src;
410 
411 	/** IPv6 destination address of the fragment */
412 	struct in6_addr dst;
413 
414 	/**
415 	 * Timeout for cancelling the reassembly. The timer is used
416 	 * also to detect if this reassembly slot is used or not.
417 	 */
418 	struct k_work_delayable timer;
419 
420 	/** Pointers to pending fragments */
421 	struct net_pkt *pkt[CONFIG_NET_IPV6_FRAGMENT_MAX_PKT];
422 
423 	/** IPv6 fragment identification */
424 	uint32_t id;
425 };
426 #else
427 struct net_ipv6_reassembly;
428 #endif
429 
430 /**
431  * @typedef net_ipv6_frag_cb_t
432  * @brief Callback used while iterating over pending IPv6 fragments.
433  *
434  * @param reass IPv6 fragment reassembly struct
435  * @param user_data A valid pointer on some user data or NULL
436  */
437 typedef void (*net_ipv6_frag_cb_t)(struct net_ipv6_reassembly *reass,
438 				   void *user_data);
439 
440 /**
441  * @brief Go through all the currently pending IPv6 fragments.
442  *
443  * @param cb Callback to call for each pending IPv6 fragment.
444  * @param user_data User specified data or NULL.
445  */
446 void net_ipv6_frag_foreach(net_ipv6_frag_cb_t cb, void *user_data);
447 
448 /**
449  * @brief Find the last IPv6 extension header in the network packet.
450  *
451  * @param pkt Network head packet.
452  * @param next_hdr_off Offset of the next header field that points
453  * to last header. This is returned to caller.
454  * @param last_hdr_off Offset of the last header field in the packet.
455  * This is returned to caller.
456  *
457  * @return 0 on success, a negative errno otherwise.
458  */
459 int net_ipv6_find_last_ext_hdr(struct net_pkt *pkt, uint16_t *next_hdr_off,
460 			       uint16_t *last_hdr_off);
461 
462 /**
463  * @brief Handles IPv6 fragmented packets.
464  *
465  * @param pkt     Network head packet.
466  * @param hdr     The IPv6 header of the current packet
467  * @param nexthdr IPv6 next header after fragment header part
468  *
469  * @return Return verdict about the packet
470  */
471 #if defined(CONFIG_NET_IPV6_FRAGMENT) && defined(CONFIG_NET_NATIVE_IPV6)
472 enum net_verdict net_ipv6_handle_fragment_hdr(struct net_pkt *pkt,
473 					      struct net_ipv6_hdr *hdr,
474 					      uint8_t nexthdr);
475 #else
476 static inline
net_ipv6_handle_fragment_hdr(struct net_pkt * pkt,struct net_ipv6_hdr * hdr,uint8_t nexthdr)477 enum net_verdict net_ipv6_handle_fragment_hdr(struct net_pkt *pkt,
478 					      struct net_ipv6_hdr *hdr,
479 					      uint8_t nexthdr)
480 {
481 	ARG_UNUSED(pkt);
482 	ARG_UNUSED(hdr);
483 	ARG_UNUSED(nexthdr);
484 
485 	return NET_DROP;
486 }
487 #endif /* CONFIG_NET_IPV6_FRAGMENT */
488 
489 #if defined(CONFIG_NET_NATIVE_IPV6)
490 void net_ipv6_init(void);
491 void net_ipv6_nbr_init(void);
492 #if defined(CONFIG_NET_IPV6_MLD)
493 void net_ipv6_mld_init(void);
494 #else
495 #define net_ipv6_mld_init(...)
496 #endif
497 #else
498 #define net_ipv6_init(...)
499 #define net_ipv6_nbr_init(...)
500 #endif
501 
502 /**
503  * @brief Decode DSCP value from TC field.
504  *
505  * @param tc TC field value from the IPv6 header.
506  *
507  * @return Decoded DSCP value.
508  */
net_ipv6_get_dscp(uint8_t tc)509 static inline uint8_t net_ipv6_get_dscp(uint8_t tc)
510 {
511 	return (tc & NET_IPV6_DSCP_MASK) >> NET_IPV6_DSCP_OFFSET;
512 }
513 
514 /**
515  * @brief Encode DSCP value into TC field.
516  *
517  * @param tc A pointer to the TC field.
518  * @param dscp DSCP value to set.
519  */
net_ipv6_set_dscp(uint8_t * tc,uint8_t dscp)520 static inline void net_ipv6_set_dscp(uint8_t *tc, uint8_t dscp)
521 {
522 	*tc &= ~NET_IPV6_DSCP_MASK;
523 	*tc |= (dscp << NET_IPV6_DSCP_OFFSET) & NET_IPV6_DSCP_MASK;
524 }
525 
526 /**
527  * @brief Convert DSCP value to priority.
528  *
529  * @param dscp DSCP value.
530  */
net_ipv6_dscp_to_priority(uint8_t dscp)531 static inline uint8_t net_ipv6_dscp_to_priority(uint8_t dscp)
532 {
533 	return dscp >> 3;
534 }
535 
536 /**
537  * @brief Decode ECN value from TC field.
538  *
539  * @param tc TC field value from the IPv6 header.
540  *
541  * @return Decoded ECN value.
542  */
net_ipv6_get_ecn(uint8_t tc)543 static inline uint8_t net_ipv6_get_ecn(uint8_t tc)
544 {
545 	return tc & NET_IPV6_ECN_MASK;
546 }
547 
548 /**
549  * @brief Encode ECN value into TC field.
550  *
551  * @param tc A pointer to the TC field.
552  * @param ecn ECN value to set.
553  */
net_ipv6_set_ecn(uint8_t * tc,uint8_t ecn)554 static inline void net_ipv6_set_ecn(uint8_t *tc, uint8_t ecn)
555 {
556 	*tc &= ~NET_IPV6_ECN_MASK;
557 	*tc |= ecn & NET_IPV6_ECN_MASK;
558 }
559 
560 
561 #endif /* __IPV6_H */
562