1 /**
2 * @file
3 * This is the IPv4 layer implementation for incoming and outgoing IP traffic.
4 *
5 * @see ip_frag.c
6 *
7 */
8
9 /*
10 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without modification,
14 * are permitted provided that the following conditions are met:
15 *
16 * 1. Redistributions of source code must retain the above copyright notice,
17 * this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright notice,
19 * this list of conditions and the following disclaimer in the documentation
20 * and/or other materials provided with the distribution.
21 * 3. The name of the author may not be used to endorse or promote products
22 * derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
25 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
27 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
28 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
29 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
32 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
33 * OF SUCH DAMAGE.
34 *
35 * This file is part of the lwIP TCP/IP stack.
36 *
37 * Author: Adam Dunkels <adam@sics.se>
38 *
39 */
40
41 #include "lwip/opt.h"
42
43 #if LWIP_IPV4
44
45 #include "lwip/ip.h"
46 #include "lwip/def.h"
47 #include "lwip/mem.h"
48 #include "lwip/ip4_frag.h"
49 #include "lwip/inet_chksum.h"
50 #include "lwip/netif.h"
51 #include "lwip/icmp.h"
52 #include "lwip/igmp.h"
53 #include "lwip/priv/raw_priv.h"
54 #include "lwip/udp.h"
55 #include "lwip/priv/tcp_priv.h"
56 #include "lwip/autoip.h"
57 #include "lwip/stats.h"
58 #include "lwip/prot/iana.h"
59
60 #include <string.h>
61
62 #ifdef LWIP_HOOK_FILENAME
63 #include LWIP_HOOK_FILENAME
64 #endif
65
66 /** Set this to 0 in the rare case of wanting to call an extra function to
67 * generate the IP checksum (in contrast to calculating it on-the-fly). */
68 #ifndef LWIP_INLINE_IP_CHKSUM
69 #if LWIP_CHECKSUM_CTRL_PER_NETIF
70 #define LWIP_INLINE_IP_CHKSUM 0
71 #else /* LWIP_CHECKSUM_CTRL_PER_NETIF */
72 #define LWIP_INLINE_IP_CHKSUM 1
73 #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
74 #endif
75
76 #if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP
77 #define CHECKSUM_GEN_IP_INLINE 1
78 #else
79 #define CHECKSUM_GEN_IP_INLINE 0
80 #endif
81
82 #if LWIP_DHCP || defined(LWIP_IP_ACCEPT_UDP_PORT)
83 #define IP_ACCEPT_LINK_LAYER_ADDRESSING 1
84
85 /** Some defines for DHCP to let link-layer-addressed packets through while the
86 * netif is down.
87 * To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT(port)
88 * to return 1 if the port is accepted and 0 if the port is not accepted.
89 */
90 #if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT)
91 /* accept DHCP client port and custom port */
92 #define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(LWIP_IANA_PORT_DHCP_CLIENT)) \
93 || (LWIP_IP_ACCEPT_UDP_PORT(port)))
94 #elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
95 /* accept custom port only */
96 #define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(port))
97 #else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
98 /* accept DHCP client port only */
99 #define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(LWIP_IANA_PORT_DHCP_CLIENT))
100 #endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
101
102 #else /* LWIP_DHCP */
103 #define IP_ACCEPT_LINK_LAYER_ADDRESSING 0
104 #endif /* LWIP_DHCP */
105
106 /** The IP header ID of the next outgoing IP packet */
107 static u16_t ip_id;
108
109 #if LWIP_MULTICAST_TX_OPTIONS
110 /** The default netif used for multicast */
111 static struct netif *ip4_default_multicast_netif;
112
113 /**
114 * @ingroup ip4
115 * Set a default netif for IPv4 multicast. */
116 void
ip4_set_default_multicast_netif(struct netif * default_multicast_netif)117 ip4_set_default_multicast_netif(struct netif *default_multicast_netif)
118 {
119 ip4_default_multicast_netif = default_multicast_netif;
120 }
121 #endif /* LWIP_MULTICAST_TX_OPTIONS */
122
123 #ifdef LWIP_HOOK_IP4_ROUTE_SRC
124 /**
125 * Source based IPv4 routing must be fully implemented in
126 * LWIP_HOOK_IP4_ROUTE_SRC(). This function only provides the parameters.
127 */
128 struct netif *
129 #ifdef LOSCFG_NET_CONTAINER
ip4_route_src(const ip4_addr_t * src,const ip4_addr_t * dest,struct net_group * group)130 ip4_route_src(const ip4_addr_t *src, const ip4_addr_t *dest, struct net_group *group)
131 #else
132 ip4_route_src(const ip4_addr_t *src, const ip4_addr_t *dest)
133 #endif
134 {
135 if (src != NULL) {
136 /* when src==NULL, the hook is called from ip4_route(dest) */
137 struct netif *netif = LWIP_HOOK_IP4_ROUTE_SRC(src, dest);
138 if (netif != NULL) {
139 return netif;
140 }
141 }
142 #ifdef LOSCFG_NET_CONTAINER
143 return ip4_route(dest, group);
144 #else
145 return ip4_route(dest);
146 #endif
147 }
148 #endif /* LWIP_HOOK_IP4_ROUTE_SRC */
149
150 /**
151 * Finds the appropriate network interface for a given IP address. It
152 * searches the list of network interfaces linearly. A match is found
153 * if the masked IP address of the network interface equals the masked
154 * IP address given to the function.
155 *
156 * @param dest the destination IP address for which to find the route
157 * @return the netif on which to send to reach dest
158 */
159 struct netif *
160 #ifdef LOSCFG_NET_CONTAINER
ip4_route(const ip4_addr_t * dest,struct net_group * group)161 ip4_route(const ip4_addr_t *dest, struct net_group *group)
162 #else
163 ip4_route(const ip4_addr_t *dest)
164 #endif
165 {
166 #if !LWIP_SINGLE_NETIF
167 struct netif *netif;
168
169 LWIP_ASSERT_CORE_LOCKED();
170
171 #if LWIP_MULTICAST_TX_OPTIONS
172 /* Use administratively selected interface for multicast by default */
173 if (ip4_addr_ismulticast(dest) && ip4_default_multicast_netif) {
174 return ip4_default_multicast_netif;
175 }
176 #endif /* LWIP_MULTICAST_TX_OPTIONS */
177
178 /* bug #54569: in case LWIP_SINGLE_NETIF=1 and LWIP_DEBUGF() disabled, the following loop is optimized away */
179 LWIP_UNUSED_ARG(dest);
180
181 /* iterate through netifs */
182 #ifdef LOSCFG_NET_CONTAINER
183 NETIF_FOREACH(netif, group) {
184 #else
185 NETIF_FOREACH(netif) {
186 #endif
187 /* is the netif up, does it have a link and a valid address? */
188 if (netif_is_up(netif) && netif_is_link_up(netif) && !ip4_addr_isany_val(*netif_ip4_addr(netif))) {
189 /* network mask matches? */
190 if (ip4_addr_netcmp(dest, netif_ip4_addr(netif), netif_ip4_netmask(netif))) {
191 /* return netif on which to forward IP packet */
192 return netif;
193 }
194 /* gateway matches on a non broadcast interface? (i.e. peer in a point to point interface) */
195 if (((netif->flags & NETIF_FLAG_BROADCAST) == 0) && ip4_addr_cmp(dest, netif_ip4_gw(netif))) {
196 /* return netif on which to forward IP packet */
197 return netif;
198 }
199 }
200 }
201
202 #if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF
203 /* loopif is disabled, looopback traffic is passed through any netif */
204 if (ip4_addr_isloopback(dest)) {
205 /* don't check for link on loopback traffic */
206 #ifdef LOSCFG_NET_CONTAINER
207 if (group->netif_default != NULL && netif_is_up(group->netif_default)) {
208 return group->netif_default;
209 #else
210 if (netif_default != NULL && netif_is_up(netif_default)) {
211 return netif_default;
212 #endif
213 }
214 /* default netif is not up, just use any netif for loopback traffic */
215 #ifdef LOSCFG_NET_CONTAINER
216 NETIF_FOREACH(netif, group) {
217 #else
218 NETIF_FOREACH(netif) {
219 #endif
220 if (netif_is_up(netif)) {
221 return netif;
222 }
223 }
224 return NULL;
225 }
226 #endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */
227
228 #ifdef LWIP_HOOK_IP4_ROUTE_SRC
229 netif = LWIP_HOOK_IP4_ROUTE_SRC(NULL, dest);
230 if (netif != NULL) {
231 return netif;
232 }
233 #elif defined(LWIP_HOOK_IP4_ROUTE)
234 netif = LWIP_HOOK_IP4_ROUTE(dest);
235 if (netif != NULL) {
236 return netif;
237 }
238 #endif
239 #endif /* !LWIP_SINGLE_NETIF */
240 #ifdef LOSCFG_NET_CONTAINER
241 if ((group->netif_default == NULL) || !netif_is_up(group->netif_default) ||
242 !netif_is_link_up(group->netif_default) ||
243 ip4_addr_isany_val(*netif_ip4_addr(group->netif_default)) || ip4_addr_isloopback(dest)) {
244 #else
245 if ((netif_default == NULL) || !netif_is_up(netif_default) || !netif_is_link_up(netif_default) ||
246 ip4_addr_isany_val(*netif_ip4_addr(netif_default)) || ip4_addr_isloopback(dest)) {
247 #endif
248 /* No matching netif found and default netif is not usable.
249 If this is not good enough for you, use LWIP_HOOK_IP4_ROUTE() */
250 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
251 ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
252 IP_STATS_INC(ip.rterr);
253 MIB2_STATS_INC(mib2.ipoutnoroutes);
254 return NULL;
255 }
256 #ifdef LOSCFG_NET_CONTAINER
257 return group->netif_default;
258 #else
259 return netif_default;
260 #endif
261 }
262
263 #if IP_FORWARD
264 /**
265 * Determine whether an IP address is in a reserved set of addresses
266 * that may not be forwarded, or whether datagrams to that destination
267 * may be forwarded.
268 * @param p the packet to forward
269 * @return 1: can forward 0: discard
270 */
271 static int
272 ip4_canforward(struct pbuf *p)
273 {
274 u32_t addr = lwip_htonl(ip4_addr_get_u32(ip4_current_dest_addr()));
275
276 #ifdef LWIP_HOOK_IP4_CANFORWARD
277 int ret = LWIP_HOOK_IP4_CANFORWARD(p, addr);
278 if (ret >= 0) {
279 return ret;
280 }
281 #endif /* LWIP_HOOK_IP4_CANFORWARD */
282
283 if (p->flags & PBUF_FLAG_LLBCAST) {
284 /* don't route link-layer broadcasts */
285 return 0;
286 }
287 if ((p->flags & PBUF_FLAG_LLMCAST) || IP_MULTICAST(addr)) {
288 /* don't route link-layer multicasts (use LWIP_HOOK_IP4_CANFORWARD instead) */
289 return 0;
290 }
291 if (IP_EXPERIMENTAL(addr)) {
292 return 0;
293 }
294 if (IP_CLASSA(addr)) {
295 u32_t net = addr & IP_CLASSA_NET;
296 if ((net == 0) || (net == ((u32_t)IP_LOOPBACKNET << IP_CLASSA_NSHIFT))) {
297 /* don't route loopback packets */
298 return 0;
299 }
300 }
301 return 1;
302 }
303
304 /**
305 * Forwards an IP packet. It finds an appropriate route for the
306 * packet, decrements the TTL value of the packet, adjusts the
307 * checksum and outputs the packet on the appropriate interface.
308 *
309 * @param p the packet to forward (p->payload points to IP header)
310 * @param iphdr the IP header of the input packet
311 * @param inp the netif on which this packet was received
312 */
313 static void
314 ip4_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
315 {
316 struct netif *netif;
317
318 PERF_START;
319 LWIP_UNUSED_ARG(inp);
320
321 if (!ip4_canforward(p)) {
322 goto return_noroute;
323 }
324
325 /* RFC3927 2.7: do not forward link-local addresses */
326 if (ip4_addr_islinklocal(ip4_current_dest_addr())) {
327 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
328 ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
329 ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
330 goto return_noroute;
331 }
332
333 /* Find network interface where to forward this IP packet to. */
334 netif = ip4_route_src(ip4_current_src_addr(), ip4_current_dest_addr());
335 if (netif == NULL) {
336 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
337 ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
338 ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
339 /* @todo: send ICMP_DUR_NET? */
340 goto return_noroute;
341 }
342 #if !IP_FORWARD_ALLOW_TX_ON_RX_NETIF
343 /* Do not forward packets onto the same network interface on which
344 * they arrived. */
345 if (netif == inp) {
346 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: not bouncing packets back on incoming interface.\n"));
347 goto return_noroute;
348 }
349 #endif /* IP_FORWARD_ALLOW_TX_ON_RX_NETIF */
350
351 /* decrement TTL */
352 IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
353 /* send ICMP if TTL == 0 */
354 if (IPH_TTL(iphdr) == 0) {
355 MIB2_STATS_INC(mib2.ipinhdrerrors);
356 #if LWIP_ICMP
357 /* Don't send ICMP messages in response to ICMP messages */
358 if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
359 icmp_time_exceeded(p, ICMP_TE_TTL);
360 }
361 #endif /* LWIP_ICMP */
362 return;
363 }
364
365 /* Incrementally update the IP checksum. */
366 if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffffU - 0x100)) {
367 IPH_CHKSUM_SET(iphdr, (u16_t)(IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1));
368 } else {
369 IPH_CHKSUM_SET(iphdr, (u16_t)(IPH_CHKSUM(iphdr) + PP_HTONS(0x100)));
370 }
371
372 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
373 ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
374 ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
375
376 IP_STATS_INC(ip.fw);
377 MIB2_STATS_INC(mib2.ipforwdatagrams);
378 IP_STATS_INC(ip.xmit);
379
380 PERF_STOP("ip4_forward");
381 /* don't fragment if interface has mtu set to 0 [loopif] */
382 if (netif->mtu && (p->tot_len > netif->mtu)) {
383 if ((IPH_OFFSET(iphdr) & PP_NTOHS(IP_DF)) == 0) {
384 #if IP_FRAG
385 ip4_frag(p, netif, ip4_current_dest_addr());
386 #else /* IP_FRAG */
387 /* @todo: send ICMP Destination Unreachable code 13 "Communication administratively prohibited"? */
388 #endif /* IP_FRAG */
389 } else {
390 #if LWIP_ICMP
391 /* send ICMP Destination Unreachable code 4: "Fragmentation Needed and DF Set" */
392 icmp_dest_unreach(p, ICMP_DUR_FRAG);
393 #endif /* LWIP_ICMP */
394 }
395 return;
396 }
397 /* transmit pbuf on chosen interface */
398 netif->output(netif, p, ip4_current_dest_addr());
399 return;
400 return_noroute:
401 MIB2_STATS_INC(mib2.ipoutnoroutes);
402 }
403 #endif /* IP_FORWARD */
404
405 /** Return true if the current input packet should be accepted on this netif */
406 static int
407 ip4_input_accept(struct netif *netif)
408 {
409 LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%"X32_F" netif->ip_addr 0x%"X32_F" (0x%"X32_F", 0x%"X32_F", 0x%"X32_F")\n",
410 ip4_addr_get_u32(ip4_current_dest_addr()), ip4_addr_get_u32(netif_ip4_addr(netif)),
411 ip4_addr_get_u32(ip4_current_dest_addr()) & ip4_addr_get_u32(netif_ip4_netmask(netif)),
412 ip4_addr_get_u32(netif_ip4_addr(netif)) & ip4_addr_get_u32(netif_ip4_netmask(netif)),
413 ip4_addr_get_u32(ip4_current_dest_addr()) & ~ip4_addr_get_u32(netif_ip4_netmask(netif))));
414
415 /* interface is up and configured? */
416 if ((netif_is_up(netif)) && (!ip4_addr_isany_val(*netif_ip4_addr(netif)))) {
417 /* unicast to this interface address? */
418 if (ip4_addr_cmp(ip4_current_dest_addr(), netif_ip4_addr(netif)) ||
419 /* or broadcast on this interface network address? */
420 ip4_addr_isbroadcast(ip4_current_dest_addr(), netif)
421 #if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF
422 || (ip4_addr_get_u32(ip4_current_dest_addr()) == PP_HTONL(IPADDR_LOOPBACK))
423 #endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */
424 ) {
425 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: packet accepted on interface %c%c\n",
426 netif->name[0], netif->name[1]));
427 /* accept on this netif */
428 return 1;
429 }
430 #if LWIP_AUTOIP
431 /* connections to link-local addresses must persist after changing
432 the netif's address (RFC3927 ch. 1.9) */
433 if (autoip_accept_packet(netif, ip4_current_dest_addr())) {
434 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: LLA packet accepted on interface %c%c\n",
435 netif->name[0], netif->name[1]));
436 /* accept on this netif */
437 return 1;
438 }
439 #endif /* LWIP_AUTOIP */
440 }
441 return 0;
442 }
443
444 /**
445 * This function is called by the network interface device driver when
446 * an IP packet is received. The function does the basic checks of the
447 * IP header such as packet size being at least larger than the header
448 * size etc. If the packet was not destined for us, the packet is
449 * forwarded (using ip_forward). The IP checksum is always checked.
450 *
451 * Finally, the packet is sent to the upper layer protocol input function.
452 *
453 * @param p the received IP packet (p->payload points to IP header)
454 * @param inp the netif on which this packet was received
455 * @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
456 * processed, but currently always returns ERR_OK)
457 */
458 err_t
459 ip4_input(struct pbuf *p, struct netif *inp)
460 {
461 const struct ip_hdr *iphdr;
462 struct netif *netif;
463 u16_t iphdr_hlen;
464 u16_t iphdr_len;
465 #if IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP
466 int check_ip_src = 1;
467 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP */
468 #if LWIP_RAW
469 raw_input_state_t raw_status;
470 #endif /* LWIP_RAW */
471
472 LWIP_ASSERT_CORE_LOCKED();
473
474 IP_STATS_INC(ip.recv);
475 MIB2_STATS_INC(mib2.ipinreceives);
476
477 #ifdef LOSCFG_NET_CONTAINER
478 struct net_group *group = get_net_group_from_netif(inp);
479 #endif
480
481 /* identify the IP header */
482 iphdr = (struct ip_hdr *)p->payload;
483 if (IPH_V(iphdr) != 4) {
484 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", (u16_t)IPH_V(iphdr)));
485 ip4_debug_print(p);
486 pbuf_free(p);
487 IP_STATS_INC(ip.err);
488 IP_STATS_INC(ip.drop);
489 MIB2_STATS_INC(mib2.ipinhdrerrors);
490 return ERR_OK;
491 }
492
493 #ifdef LWIP_HOOK_IP4_INPUT
494 if (LWIP_HOOK_IP4_INPUT(p, inp)) {
495 /* the packet has been eaten */
496 return ERR_OK;
497 }
498 #endif
499
500 /* obtain IP header length in bytes */
501 iphdr_hlen = IPH_HL_BYTES(iphdr);
502 /* obtain ip length in bytes */
503 iphdr_len = lwip_ntohs(IPH_LEN(iphdr));
504
505 /* Trim pbuf. This is especially required for packets < 60 bytes. */
506 if (iphdr_len < p->tot_len) {
507 pbuf_realloc(p, iphdr_len);
508 }
509
510 /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
511 if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len) || (iphdr_hlen < IP_HLEN)) {
512 if (iphdr_hlen < IP_HLEN) {
513 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
514 ("ip4_input: short IP header (%"U16_F" bytes) received, IP packet dropped\n", iphdr_hlen));
515 }
516 if (iphdr_hlen > p->len) {
517 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
518 ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
519 iphdr_hlen, p->len));
520 }
521 if (iphdr_len > p->tot_len) {
522 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
523 ("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
524 iphdr_len, p->tot_len));
525 }
526 /* free (drop) packet pbufs */
527 pbuf_free(p);
528 IP_STATS_INC(ip.lenerr);
529 IP_STATS_INC(ip.drop);
530 MIB2_STATS_INC(mib2.ipindiscards);
531 return ERR_OK;
532 }
533
534 /* verify checksum */
535 #if CHECKSUM_CHECK_IP
536 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_IP) {
537 if (inet_chksum(iphdr, iphdr_hlen) != 0) {
538
539 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
540 ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
541 ip4_debug_print(p);
542 pbuf_free(p);
543 IP_STATS_INC(ip.chkerr);
544 IP_STATS_INC(ip.drop);
545 MIB2_STATS_INC(mib2.ipinhdrerrors);
546 return ERR_OK;
547 }
548 }
549 #endif
550
551 /* copy IP addresses to aligned ip_addr_t */
552 ip_addr_copy_from_ip4(ip_data.current_iphdr_dest, iphdr->dest);
553 ip_addr_copy_from_ip4(ip_data.current_iphdr_src, iphdr->src);
554
555 /* match packet against an interface, i.e. is this packet for us? */
556 if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
557 #if LWIP_IGMP
558 if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, ip4_current_dest_addr()))) {
559 /* IGMP snooping switches need 0.0.0.0 to be allowed as source address (RFC 4541) */
560 ip4_addr_t allsystems;
561 IP4_ADDR(&allsystems, 224, 0, 0, 1);
562 if (ip4_addr_cmp(ip4_current_dest_addr(), &allsystems) &&
563 ip4_addr_isany(ip4_current_src_addr())) {
564 check_ip_src = 0;
565 }
566 netif = inp;
567 } else {
568 netif = NULL;
569 }
570 #else /* LWIP_IGMP */
571 if ((netif_is_up(inp)) && (!ip4_addr_isany_val(*netif_ip4_addr(inp)))) {
572 netif = inp;
573 } else {
574 netif = NULL;
575 }
576 #endif /* LWIP_IGMP */
577 } else {
578 /* start trying with inp. if that's not acceptable, start walking the
579 list of configured netifs. */
580 if (ip4_input_accept(inp)) {
581 netif = inp;
582 } else {
583 netif = NULL;
584 #if !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF
585 /* Packets sent to the loopback address must not be accepted on an
586 * interface that does not have the loopback address assigned to it,
587 * unless a non-loopback interface is used for loopback traffic. */
588 if (!ip4_addr_isloopback(ip4_current_dest_addr()))
589 #endif /* !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF */
590 {
591 #if !LWIP_SINGLE_NETIF
592 #ifdef LOSCFG_NET_CONTAINER
593 NETIF_FOREACH(netif, group) {
594 #else
595 NETIF_FOREACH(netif) {
596 #endif
597 if (netif == inp) {
598 /* we checked that before already */
599 continue;
600 }
601 if (ip4_input_accept(netif)) {
602 break;
603 }
604 }
605 #endif /* !LWIP_SINGLE_NETIF */
606 }
607 }
608 }
609
610 #if IP_ACCEPT_LINK_LAYER_ADDRESSING
611 /* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
612 * using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
613 * According to RFC 1542 section 3.1.1, referred by RFC 2131).
614 *
615 * If you want to accept private broadcast communication while a netif is down,
616 * define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
617 *
618 * #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
619 */
620 if (netif == NULL) {
621 /* remote port is DHCP server? */
622 if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
623 const struct udp_hdr *udphdr = (const struct udp_hdr *)((const u8_t *)iphdr + iphdr_hlen);
624 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: UDP packet to DHCP client port %"U16_F"\n",
625 lwip_ntohs(udphdr->dest)));
626 if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
627 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: DHCP packet accepted.\n"));
628 netif = inp;
629 check_ip_src = 0;
630 }
631 }
632 }
633 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
634
635 /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
636 #if LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING
637 if (check_ip_src
638 #if IP_ACCEPT_LINK_LAYER_ADDRESSING
639 /* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
640 && !ip4_addr_isany_val(*ip4_current_src_addr())
641 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
642 )
643 #endif /* LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING */
644 {
645 if ((ip4_addr_isbroadcast(ip4_current_src_addr(), inp)) ||
646 (ip4_addr_ismulticast(ip4_current_src_addr()))) {
647 /* packet source is not valid */
648 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("ip4_input: packet source is not valid.\n"));
649 /* free (drop) packet pbufs */
650 pbuf_free(p);
651 IP_STATS_INC(ip.drop);
652 MIB2_STATS_INC(mib2.ipinaddrerrors);
653 MIB2_STATS_INC(mib2.ipindiscards);
654 return ERR_OK;
655 }
656 }
657
658 /* packet not for us? */
659 if (netif == NULL) {
660 /* packet not for us, route or discard */
661 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: packet not for us.\n"));
662 #if IP_FORWARD
663 /* non-broadcast packet? */
664 if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), inp)) {
665 /* try to forward IP packet on (other) interfaces */
666 ip4_forward(p, (struct ip_hdr *)p->payload, inp);
667 } else
668 #endif /* IP_FORWARD */
669 {
670 IP_STATS_INC(ip.drop);
671 MIB2_STATS_INC(mib2.ipinaddrerrors);
672 MIB2_STATS_INC(mib2.ipindiscards);
673 }
674 pbuf_free(p);
675 return ERR_OK;
676 }
677 /* packet consists of multiple fragments? */
678 if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK | IP_MF)) != 0) {
679 #if IP_REASSEMBLY /* packet fragment reassembly code present? */
680 LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04"X16_F" tot_len=%"U16_F" len=%"U16_F" MF=%"U16_F" offset=%"U16_F"), calling ip4_reass()\n",
681 lwip_ntohs(IPH_ID(iphdr)), p->tot_len, lwip_ntohs(IPH_LEN(iphdr)), (u16_t)!!(IPH_OFFSET(iphdr) & PP_HTONS(IP_MF)), (u16_t)((lwip_ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK) * 8)));
682 /* reassemble the packet*/
683 p = ip4_reass(p);
684 /* packet not fully reassembled yet? */
685 if (p == NULL) {
686 return ERR_OK;
687 }
688 iphdr = (const struct ip_hdr *)p->payload;
689 #else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
690 pbuf_free(p);
691 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
692 lwip_ntohs(IPH_OFFSET(iphdr))));
693 IP_STATS_INC(ip.opterr);
694 IP_STATS_INC(ip.drop);
695 /* unsupported protocol feature */
696 MIB2_STATS_INC(mib2.ipinunknownprotos);
697 return ERR_OK;
698 #endif /* IP_REASSEMBLY */
699 }
700
701 #if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
702
703 #if LWIP_IGMP
704 /* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
705 if ((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
706 #else
707 if (iphdr_hlen > IP_HLEN) {
708 #endif /* LWIP_IGMP */
709 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
710 pbuf_free(p);
711 IP_STATS_INC(ip.opterr);
712 IP_STATS_INC(ip.drop);
713 /* unsupported protocol feature */
714 MIB2_STATS_INC(mib2.ipinunknownprotos);
715 return ERR_OK;
716 }
717 #endif /* IP_OPTIONS_ALLOWED == 0 */
718
719 /* send to upper layers */
720 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: \n"));
721 ip4_debug_print(p);
722 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
723
724 ip_data.current_netif = netif;
725 ip_data.current_input_netif = inp;
726 ip_data.current_ip4_header = iphdr;
727 ip_data.current_ip_header_tot_len = IPH_HL_BYTES(iphdr);
728
729 #if LWIP_RAW
730 /* raw input did not eat the packet? */
731 raw_status = raw_input(p, inp);
732 if (raw_status != RAW_INPUT_EATEN)
733 #endif /* LWIP_RAW */
734 {
735 pbuf_remove_header(p, iphdr_hlen); /* Move to payload, no check necessary. */
736
737 switch (IPH_PROTO(iphdr)) {
738 #if LWIP_UDP
739 case IP_PROTO_UDP:
740 #if LWIP_UDPLITE
741 case IP_PROTO_UDPLITE:
742 #endif /* LWIP_UDPLITE */
743 MIB2_STATS_INC(mib2.ipindelivers);
744 udp_input(p, inp);
745 break;
746 #endif /* LWIP_UDP */
747 #if LWIP_TCP
748 case IP_PROTO_TCP:
749 MIB2_STATS_INC(mib2.ipindelivers);
750 tcp_input(p, inp);
751 break;
752 #endif /* LWIP_TCP */
753 #if LWIP_ICMP
754 case IP_PROTO_ICMP:
755 MIB2_STATS_INC(mib2.ipindelivers);
756 icmp_input(p, inp);
757 break;
758 #endif /* LWIP_ICMP */
759 #if LWIP_IGMP
760 case IP_PROTO_IGMP:
761 igmp_input(p, inp, ip4_current_dest_addr());
762 break;
763 #endif /* LWIP_IGMP */
764 default:
765 #if LWIP_RAW
766 if (raw_status == RAW_INPUT_DELIVERED) {
767 MIB2_STATS_INC(mib2.ipindelivers);
768 } else
769 #endif /* LWIP_RAW */
770 {
771 #if LWIP_ICMP
772 /* send ICMP destination protocol unreachable unless is was a broadcast */
773 if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), netif) &&
774 !ip4_addr_ismulticast(ip4_current_dest_addr())) {
775 pbuf_header_force(p, (s16_t)iphdr_hlen); /* Move to ip header, no check necessary. */
776 icmp_dest_unreach(p, ICMP_DUR_PROTO);
777 }
778 #endif /* LWIP_ICMP */
779
780 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", (u16_t)IPH_PROTO(iphdr)));
781
782 IP_STATS_INC(ip.proterr);
783 IP_STATS_INC(ip.drop);
784 MIB2_STATS_INC(mib2.ipinunknownprotos);
785 }
786 pbuf_free(p);
787 break;
788 }
789 }
790
791 /* @todo: this is not really necessary... */
792 ip_data.current_netif = NULL;
793 ip_data.current_input_netif = NULL;
794 ip_data.current_ip4_header = NULL;
795 ip_data.current_ip_header_tot_len = 0;
796 ip4_addr_set_any(ip4_current_src_addr());
797 ip4_addr_set_any(ip4_current_dest_addr());
798
799 return ERR_OK;
800 }
801
802 /**
803 * Sends an IP packet on a network interface. This function constructs
804 * the IP header and calculates the IP header checksum. If the source
805 * IP address is NULL, the IP address of the outgoing network
806 * interface is filled in as source address.
807 * If the destination IP address is LWIP_IP_HDRINCL, p is assumed to already
808 * include an IP header and p->payload points to it instead of the data.
809 *
810 * @param p the packet to send (p->payload points to the data, e.g. next
811 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
812 IP header and p->payload points to that IP header)
813 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
814 * IP address of the netif used to send is used as source address)
815 * @param dest the destination IP address to send the packet to
816 * @param ttl the TTL value to be set in the IP header
817 * @param tos the TOS value to be set in the IP header
818 * @param proto the PROTOCOL to be set in the IP header
819 * @param netif the netif on which to send this packet
820 * @return ERR_OK if the packet was sent OK
821 * ERR_BUF if p doesn't have enough space for IP/LINK headers
822 * returns errors returned by netif->output
823 *
824 * @note ip_id: RFC791 "some host may be able to simply use
825 * unique identifiers independent of destination"
826 */
827 err_t
828 ip4_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
829 u8_t ttl, u8_t tos,
830 u8_t proto, struct netif *netif)
831 {
832 #if IP_OPTIONS_SEND
833 return ip4_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
834 }
835
836 /**
837 * Same as ip_output_if() but with the possibility to include IP options:
838 *
839 * @ param ip_options pointer to the IP options, copied into the IP header
840 * @ param optlen length of ip_options
841 */
842 err_t
843 ip4_output_if_opt(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
844 u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
845 u16_t optlen)
846 {
847 #endif /* IP_OPTIONS_SEND */
848 const ip4_addr_t *src_used = src;
849 if (dest != LWIP_IP_HDRINCL) {
850 if (ip4_addr_isany(src)) {
851 src_used = netif_ip4_addr(netif);
852 }
853 }
854
855 #if IP_OPTIONS_SEND
856 return ip4_output_if_opt_src(p, src_used, dest, ttl, tos, proto, netif,
857 ip_options, optlen);
858 #else /* IP_OPTIONS_SEND */
859 return ip4_output_if_src(p, src_used, dest, ttl, tos, proto, netif);
860 #endif /* IP_OPTIONS_SEND */
861 }
862
863 /**
864 * Same as ip_output_if() but 'src' address is not replaced by netif address
865 * when it is 'any'.
866 */
867 err_t
868 ip4_output_if_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
869 u8_t ttl, u8_t tos,
870 u8_t proto, struct netif *netif)
871 {
872 #if IP_OPTIONS_SEND
873 return ip4_output_if_opt_src(p, src, dest, ttl, tos, proto, netif, NULL, 0);
874 }
875
876 /**
877 * Same as ip_output_if_opt() but 'src' address is not replaced by netif address
878 * when it is 'any'.
879 */
880 err_t
881 ip4_output_if_opt_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
882 u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
883 u16_t optlen)
884 {
885 #endif /* IP_OPTIONS_SEND */
886 struct ip_hdr *iphdr;
887 ip4_addr_t dest_addr;
888 #if CHECKSUM_GEN_IP_INLINE
889 u32_t chk_sum = 0;
890 #endif /* CHECKSUM_GEN_IP_INLINE */
891
892 LWIP_ASSERT_CORE_LOCKED();
893 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
894
895 MIB2_STATS_INC(mib2.ipoutrequests);
896
897 /* Should the IP header be generated or is it already included in p? */
898 if (dest != LWIP_IP_HDRINCL) {
899 u16_t ip_hlen = IP_HLEN;
900 #if IP_OPTIONS_SEND
901 u16_t optlen_aligned = 0;
902 if (optlen != 0) {
903 #if CHECKSUM_GEN_IP_INLINE
904 int i;
905 #endif /* CHECKSUM_GEN_IP_INLINE */
906 if (optlen > (IP_HLEN_MAX - IP_HLEN)) {
907 /* optlen too long */
908 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: optlen too long\n"));
909 IP_STATS_INC(ip.err);
910 MIB2_STATS_INC(mib2.ipoutdiscards);
911 return ERR_VAL;
912 }
913 /* round up to a multiple of 4 */
914 optlen_aligned = (u16_t)((optlen + 3) & ~3);
915 ip_hlen = (u16_t)(ip_hlen + optlen_aligned);
916 /* First write in the IP options */
917 if (pbuf_add_header(p, optlen_aligned)) {
918 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: not enough room for IP options in pbuf\n"));
919 IP_STATS_INC(ip.err);
920 MIB2_STATS_INC(mib2.ipoutdiscards);
921 return ERR_BUF;
922 }
923 MEMCPY(p->payload, ip_options, optlen);
924 if (optlen < optlen_aligned) {
925 /* zero the remaining bytes */
926 memset(((char *)p->payload) + optlen, 0, (size_t)(optlen_aligned - optlen));
927 }
928 #if CHECKSUM_GEN_IP_INLINE
929 for (i = 0; i < optlen_aligned / 2; i++) {
930 chk_sum += ((u16_t *)p->payload)[i];
931 }
932 #endif /* CHECKSUM_GEN_IP_INLINE */
933 }
934 #endif /* IP_OPTIONS_SEND */
935 /* generate IP header */
936 if (pbuf_add_header(p, IP_HLEN)) {
937 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: not enough room for IP header in pbuf\n"));
938
939 IP_STATS_INC(ip.err);
940 MIB2_STATS_INC(mib2.ipoutdiscards);
941 return ERR_BUF;
942 }
943
944 iphdr = (struct ip_hdr *)p->payload;
945 LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
946 (p->len >= sizeof(struct ip_hdr)));
947
948 IPH_TTL_SET(iphdr, ttl);
949 IPH_PROTO_SET(iphdr, proto);
950 #if CHECKSUM_GEN_IP_INLINE
951 chk_sum += PP_NTOHS(proto | (ttl << 8));
952 #endif /* CHECKSUM_GEN_IP_INLINE */
953
954 /* dest cannot be NULL here */
955 ip4_addr_copy(iphdr->dest, *dest);
956 #if CHECKSUM_GEN_IP_INLINE
957 chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
958 chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
959 #endif /* CHECKSUM_GEN_IP_INLINE */
960
961 IPH_VHL_SET(iphdr, 4, ip_hlen / 4);
962 IPH_TOS_SET(iphdr, tos);
963 #if CHECKSUM_GEN_IP_INLINE
964 chk_sum += PP_NTOHS(tos | (iphdr->_v_hl << 8));
965 #endif /* CHECKSUM_GEN_IP_INLINE */
966 IPH_LEN_SET(iphdr, lwip_htons(p->tot_len));
967 #if CHECKSUM_GEN_IP_INLINE
968 chk_sum += iphdr->_len;
969 #endif /* CHECKSUM_GEN_IP_INLINE */
970 IPH_OFFSET_SET(iphdr, 0);
971 IPH_ID_SET(iphdr, lwip_htons(ip_id));
972 #if CHECKSUM_GEN_IP_INLINE
973 chk_sum += iphdr->_id;
974 #endif /* CHECKSUM_GEN_IP_INLINE */
975 ++ip_id;
976
977 if (src == NULL) {
978 ip4_addr_copy(iphdr->src, *IP4_ADDR_ANY4);
979 } else {
980 /* src cannot be NULL here */
981 ip4_addr_copy(iphdr->src, *src);
982 }
983
984 #if CHECKSUM_GEN_IP_INLINE
985 chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
986 chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
987 chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
988 chk_sum = (chk_sum >> 16) + chk_sum;
989 chk_sum = ~chk_sum;
990 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
991 iphdr->_chksum = (u16_t)chk_sum; /* network order */
992 }
993 #if LWIP_CHECKSUM_CTRL_PER_NETIF
994 else {
995 IPH_CHKSUM_SET(iphdr, 0);
996 }
997 #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF*/
998 #else /* CHECKSUM_GEN_IP_INLINE */
999 IPH_CHKSUM_SET(iphdr, 0);
1000 #if CHECKSUM_GEN_IP
1001 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
1002 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
1003 }
1004 #endif /* CHECKSUM_GEN_IP */
1005 #endif /* CHECKSUM_GEN_IP_INLINE */
1006 } else {
1007 /* IP header already included in p */
1008 if (p->len < IP_HLEN) {
1009 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: LWIP_IP_HDRINCL but pbuf is too short\n"));
1010 IP_STATS_INC(ip.err);
1011 MIB2_STATS_INC(mib2.ipoutdiscards);
1012 return ERR_BUF;
1013 }
1014 iphdr = (struct ip_hdr *)p->payload;
1015 ip4_addr_copy(dest_addr, iphdr->dest);
1016 dest = &dest_addr;
1017 }
1018
1019 IP_STATS_INC(ip.xmit);
1020
1021 LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], (u16_t)netif->num));
1022 ip4_debug_print(p);
1023
1024 #if ENABLE_LOOPBACK
1025 if (ip4_addr_cmp(dest, netif_ip4_addr(netif))
1026 #if !LWIP_HAVE_LOOPIF
1027 || ip4_addr_isloopback(dest)
1028 #endif /* !LWIP_HAVE_LOOPIF */
1029 ) {
1030 /* Packet to self, enqueue it for loopback */
1031 LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
1032 return netif_loop_output(netif, p);
1033 }
1034 #if LWIP_MULTICAST_TX_OPTIONS
1035 if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
1036 netif_loop_output(netif, p);
1037 }
1038 #endif /* LWIP_MULTICAST_TX_OPTIONS */
1039 #endif /* ENABLE_LOOPBACK */
1040 #if IP_FRAG
1041 /* don't fragment if interface has mtu set to 0 [loopif] */
1042 if (netif->mtu && (p->tot_len > netif->mtu)) {
1043 return ip4_frag(p, netif, dest);
1044 }
1045 #endif /* IP_FRAG */
1046
1047 LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: call netif->output()\n"));
1048 return netif->output(netif, p, dest);
1049 }
1050
1051 /**
1052 * Simple interface to ip_output_if. It finds the outgoing network
1053 * interface and calls upon ip_output_if to do the actual work.
1054 *
1055 * @param p the packet to send (p->payload points to the data, e.g. next
1056 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
1057 IP header and p->payload points to that IP header)
1058 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
1059 * IP address of the netif used to send is used as source address)
1060 * @param dest the destination IP address to send the packet to
1061 * @param ttl the TTL value to be set in the IP header
1062 * @param tos the TOS value to be set in the IP header
1063 * @param proto the PROTOCOL to be set in the IP header
1064 *
1065 * @return ERR_RTE if no route is found
1066 * see ip_output_if() for more return values
1067 */
1068 err_t
1069 ip4_output(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
1070 u8_t ttl, u8_t tos, u8_t proto)
1071 {
1072 struct netif *netif;
1073
1074 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
1075 #ifdef LOSCFG_NET_CONTAINER
1076 struct net_group *group = get_curr_process_net_group();
1077
1078 if ((netif = ip4_route_src(src, dest, group)) == NULL) {
1079 #else
1080 if ((netif = ip4_route_src(src, dest)) == NULL) {
1081 #endif
1082 LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
1083 ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
1084 IP_STATS_INC(ip.rterr);
1085 return ERR_RTE;
1086 }
1087
1088 return ip4_output_if(p, src, dest, ttl, tos, proto, netif);
1089 }
1090
1091 #if LWIP_NETIF_USE_HINTS
1092 /** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
1093 * before calling ip_output_if.
1094 *
1095 * @param p the packet to send (p->payload points to the data, e.g. next
1096 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
1097 IP header and p->payload points to that IP header)
1098 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
1099 * IP address of the netif used to send is used as source address)
1100 * @param dest the destination IP address to send the packet to
1101 * @param ttl the TTL value to be set in the IP header
1102 * @param tos the TOS value to be set in the IP header
1103 * @param proto the PROTOCOL to be set in the IP header
1104 * @param netif_hint netif output hint pointer set to netif->hint before
1105 * calling ip_output_if()
1106 *
1107 * @return ERR_RTE if no route is found
1108 * see ip_output_if() for more return values
1109 */
1110 err_t
1111 ip4_output_hinted(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
1112 u8_t ttl, u8_t tos, u8_t proto, struct netif_hint *netif_hint)
1113 {
1114 struct netif *netif;
1115 err_t err;
1116
1117 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
1118
1119 if ((netif = ip4_route_src(src, dest)) == NULL) {
1120 LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
1121 ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
1122 IP_STATS_INC(ip.rterr);
1123 return ERR_RTE;
1124 }
1125
1126 NETIF_SET_HINTS(netif, netif_hint);
1127 err = ip4_output_if(p, src, dest, ttl, tos, proto, netif);
1128 NETIF_RESET_HINTS(netif);
1129
1130 return err;
1131 }
1132 #endif /* LWIP_NETIF_USE_HINTS*/
1133
1134 #if IP_DEBUG
1135 /* Print an IP header by using LWIP_DEBUGF
1136 * @param p an IP packet, p->payload pointing to the IP header
1137 */
1138 void
1139 ip4_debug_print(struct pbuf *p)
1140 {
1141 struct ip_hdr *iphdr = (struct ip_hdr *)p->payload;
1142
1143 LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
1144 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1145 LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" | 0x%02"X16_F" | %5"U16_F" | (v, hl, tos, len)\n",
1146 (u16_t)IPH_V(iphdr),
1147 (u16_t)IPH_HL(iphdr),
1148 (u16_t)IPH_TOS(iphdr),
1149 lwip_ntohs(IPH_LEN(iphdr))));
1150 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1151 LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" |%"U16_F"%"U16_F"%"U16_F"| %4"U16_F" | (id, flags, offset)\n",
1152 lwip_ntohs(IPH_ID(iphdr)),
1153 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 15 & 1),
1154 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 14 & 1),
1155 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 13 & 1),
1156 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)));
1157 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1158 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | 0x%04"X16_F" | (ttl, proto, chksum)\n",
1159 (u16_t)IPH_TTL(iphdr),
1160 (u16_t)IPH_PROTO(iphdr),
1161 lwip_ntohs(IPH_CHKSUM(iphdr))));
1162 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1163 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (src)\n",
1164 ip4_addr1_16_val(iphdr->src),
1165 ip4_addr2_16_val(iphdr->src),
1166 ip4_addr3_16_val(iphdr->src),
1167 ip4_addr4_16_val(iphdr->src)));
1168 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1169 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (dest)\n",
1170 ip4_addr1_16_val(iphdr->dest),
1171 ip4_addr2_16_val(iphdr->dest),
1172 ip4_addr3_16_val(iphdr->dest),
1173 ip4_addr4_16_val(iphdr->dest)));
1174 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1175 }
1176 #endif /* IP_DEBUG */
1177
1178 #endif /* LWIP_IPV4 */
1179