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/raw.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/dhcp.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(DHCP_CLIENT_PORT)) \
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(DHCP_CLIENT_PORT))
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 he parameters.
127 */
128 struct netif *
ip4_route_src(const ip4_addr_t * dest,const ip4_addr_t * src)129 ip4_route_src(const ip4_addr_t *dest, const ip4_addr_t *src)
130 {
131 if (src != NULL) {
132 /* when src==NULL, the hook is called from ip4_route(dest) */
133 struct netif *netif = LWIP_HOOK_IP4_ROUTE_SRC(dest, src);
134 if (netif != NULL) {
135 return netif;
136 }
137 }
138 return ip4_route(dest);
139 }
140 #endif /* LWIP_HOOK_IP4_ROUTE_SRC */
141
142 /**
143 * Finds the appropriate network interface for a given IP address. It
144 * searches the list of network interfaces linearly. A match is found
145 * if the masked IP address of the network interface equals the masked
146 * IP address given to the function.
147 *
148 * @param dest the destination IP address for which to find the route
149 * @return the netif on which to send to reach dest
150 */
151 struct netif *
152 __weak
ip4_route(const ip4_addr_t * dest)153 ip4_route(const ip4_addr_t *dest)
154 {
155 #if !LWIP_SINGLE_NETIF
156 struct netif *netif;
157
158 #if LWIP_MULTICAST_TX_OPTIONS
159 /* Use administratively selected interface for multicast by default */
160 if (ip4_addr_ismulticast(dest) && ip4_default_multicast_netif) {
161 return ip4_default_multicast_netif;
162 }
163 #endif /* LWIP_MULTICAST_TX_OPTIONS */
164
165 /* iterate through netifs */
166 for (netif = netif_list; netif != NULL; netif = netif->next) {
167 /* is the netif up, does it have a link and a valid address? */
168 if (netif_is_up(netif) && netif_is_link_up(netif) && !ip4_addr_isany_val(*netif_ip4_addr(netif))) {
169 /* network mask matches? */
170 if (ip4_addr_netcmp(dest, netif_ip4_addr(netif), netif_ip4_netmask(netif))) {
171 /* return netif on which to forward IP packet */
172 return netif;
173 }
174 /* gateway matches on a non broadcast interface? (i.e. peer in a point to point interface) */
175 if (((netif->flags & NETIF_FLAG_BROADCAST) == 0) && ip4_addr_cmp(dest, netif_ip4_gw(netif))) {
176 /* return netif on which to forward IP packet */
177 return netif;
178 }
179 }
180 }
181
182 #if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF
183 /* loopif is disabled, looopback traffic is passed through any netif */
184 if (ip4_addr_isloopback(dest)) {
185 /* don't check for link on loopback traffic */
186 if (netif_default != NULL && netif_is_up(netif_default)) {
187 return netif_default;
188 }
189 /* default netif is not up, just use any netif for loopback traffic */
190 for (netif = netif_list; netif != NULL; netif = netif->next) {
191 if (netif_is_up(netif)) {
192 return netif;
193 }
194 }
195 return NULL;
196 }
197 #endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */
198
199 #ifdef LWIP_HOOK_IP4_ROUTE_SRC
200 netif = LWIP_HOOK_IP4_ROUTE_SRC(dest, NULL);
201 if (netif != NULL) {
202 return netif;
203 }
204 #elif defined(LWIP_HOOK_IP4_ROUTE)
205 netif = LWIP_HOOK_IP4_ROUTE(dest);
206 if (netif != NULL) {
207 return netif;
208 }
209 #endif
210 #endif /* !LWIP_SINGLE_NETIF */
211
212 if ((netif_default == NULL) || !netif_is_up(netif_default) || !netif_is_link_up(netif_default) ||
213 ip4_addr_isany_val(*netif_ip4_addr(netif_default))) {
214 /* No matching netif found and default netif is not usable.
215 If this is not good enough for you, use LWIP_HOOK_IP4_ROUTE() */
216 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
217 ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
218 IP_STATS_INC(ip.rterr);
219 MIB2_STATS_INC(mib2.ipoutnoroutes);
220 return NULL;
221 }
222
223 return netif_default;
224 }
225
226 #if IP_FORWARD
227 /**
228 * Determine whether an IP address is in a reserved set of addresses
229 * that may not be forwarded, or whether datagrams to that destination
230 * may be forwarded.
231 * @param p the packet to forward
232 * @return 1: can forward 0: discard
233 */
234 static int
ip4_canforward(struct pbuf * p)235 ip4_canforward(struct pbuf *p)
236 {
237 u32_t addr = lwip_htonl(ip4_addr_get_u32(ip4_current_dest_addr()));
238
239 if (p->flags & PBUF_FLAG_LLBCAST) {
240 /* don't route link-layer broadcasts */
241 return 0;
242 }
243 if ((p->flags & PBUF_FLAG_LLMCAST) && !IP_MULTICAST(addr)) {
244 /* don't route link-layer multicasts unless the destination address is an IP
245 multicast address */
246 return 0;
247 }
248 if (IP_EXPERIMENTAL(addr)) {
249 return 0;
250 }
251 if (IP_CLASSA(addr)) {
252 u32_t net = addr & IP_CLASSA_NET;
253 if ((net == 0) || (net == ((u32_t)IP_LOOPBACKNET << IP_CLASSA_NSHIFT))) {
254 /* don't route loopback packets */
255 return 0;
256 }
257 }
258 return 1;
259 }
260
261 /**
262 * Forwards an IP packet. It finds an appropriate route for the
263 * packet, decrements the TTL value of the packet, adjusts the
264 * checksum and outputs the packet on the appropriate interface.
265 *
266 * @param p the packet to forward (p->payload points to IP header)
267 * @param iphdr the IP header of the input packet
268 * @param inp the netif on which this packet was received
269 */
270 static void
ip4_forward(struct pbuf * p,struct ip_hdr * iphdr,struct netif * inp)271 ip4_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
272 {
273 struct netif *netif;
274
275 #if defined(__minix)
276 /* MINIX 3 only: forward packets only when enabled through configuration. */
277 if (!lwip_ip4_forward) {
278 return;
279 }
280 #endif /* defined(__minix) */
281
282 PERF_START;
283 LWIP_UNUSED_ARG(inp);
284
285 if (!ip4_canforward(p)) {
286 goto return_noroute;
287 }
288
289 /* RFC3927 2.7: do not forward link-local addresses */
290 if (ip4_addr_islinklocal(ip4_current_dest_addr())) {
291 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
292 ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
293 ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
294 goto return_noroute;
295 }
296
297 /* Find network interface where to forward this IP packet to. */
298 netif = ip4_route_src(ip4_current_dest_addr(), ip4_current_src_addr());
299 if (netif == NULL) {
300 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
301 ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
302 ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
303 /* @todo: send ICMP_DUR_NET? */
304 goto return_noroute;
305 }
306 #if !IP_FORWARD_ALLOW_TX_ON_RX_NETIF
307 /* Do not forward packets onto the same network interface on which
308 * they arrived. */
309 if (netif == inp) {
310 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: not bouncing packets back on incoming interface.\n"));
311 goto return_noroute;
312 }
313 #endif /* IP_FORWARD_ALLOW_TX_ON_RX_NETIF */
314
315 /* decrement TTL */
316 IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
317 /* send ICMP if TTL == 0 */
318 if (IPH_TTL(iphdr) == 0) {
319 MIB2_STATS_INC(mib2.ipinhdrerrors);
320 #if LWIP_ICMP
321 /* Don't send ICMP messages in response to ICMP messages */
322 if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
323 icmp_time_exceeded(p, ICMP_TE_TTL);
324 }
325 #endif /* LWIP_ICMP */
326 return;
327 }
328
329 /* Incrementally update the IP checksum. */
330 if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffffU - 0x100)) {
331 IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1);
332 } else {
333 IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100));
334 }
335
336 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\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
340 IP_STATS_INC(ip.fw);
341 MIB2_STATS_INC(mib2.ipforwdatagrams);
342 IP_STATS_INC(ip.xmit);
343
344 PERF_STOP("ip4_forward");
345 /* don't fragment if interface has mtu set to 0 [loopif] */
346 if (netif->mtu && (p->tot_len > netif->mtu)) {
347 if ((IPH_OFFSET(iphdr) & PP_NTOHS(IP_DF)) == 0) {
348 #if IP_FRAG
349 ip4_frag(p, netif, ip4_current_dest_addr());
350 #else /* IP_FRAG */
351 /* @todo: send ICMP Destination Unreachable code 13 "Communication administratively prohibited"? */
352 #endif /* IP_FRAG */
353 } else {
354 #if LWIP_ICMP
355 /* send ICMP Destination Unreachable code 4: "Fragmentation Needed and DF Set" */
356 icmp_dest_unreach(p, ICMP_DUR_FRAG);
357 #endif /* LWIP_ICMP */
358 }
359 return;
360 }
361 /* transmit pbuf on chosen interface */
362 netif->output(netif, p, ip4_current_dest_addr());
363 return;
364 return_noroute:
365 MIB2_STATS_INC(mib2.ipoutnoroutes);
366 }
367 #endif /* IP_FORWARD */
368
369 /** Return true if the current input packet should be accepted on this netif */
370 static int
ip4_input_accept(struct netif * netif)371 ip4_input_accept(struct netif *netif)
372 {
373 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",
374 ip4_addr_get_u32(ip4_current_dest_addr()), ip4_addr_get_u32(netif_ip4_addr(netif)),
375 ip4_addr_get_u32(ip4_current_dest_addr()) & ip4_addr_get_u32(netif_ip4_netmask(netif)),
376 ip4_addr_get_u32(netif_ip4_addr(netif)) & ip4_addr_get_u32(netif_ip4_netmask(netif)),
377 ip4_addr_get_u32(ip4_current_dest_addr()) & ~ip4_addr_get_u32(netif_ip4_netmask(netif))));
378
379 /* interface is up and configured? */
380 if ((netif_is_up(netif)) && (!ip4_addr_isany_val(*netif_ip4_addr(netif)))) {
381 /* unicast to this interface address? */
382 if (ip4_addr_cmp(ip4_current_dest_addr(), netif_ip4_addr(netif)) ||
383 /* or broadcast on this interface network address? */
384 ip4_addr_isbroadcast(ip4_current_dest_addr(), netif)
385 #if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF
386 || (ip4_addr_get_u32(ip4_current_dest_addr()) == PP_HTONL(IPADDR_LOOPBACK))
387 #endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */
388 ) {
389 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: packet accepted on interface %c%c\n",
390 netif->name[0], netif->name[1]));
391 /* accept on this netif */
392 return 1;
393 }
394 #if LWIP_AUTOIP
395 /* connections to link-local addresses must persist after changing
396 the netif's address (RFC3927 ch. 1.9) */
397 if (autoip_accept_packet(netif, ip4_current_dest_addr())) {
398 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: LLA packet accepted on interface %c%c\n",
399 netif->name[0], netif->name[1]));
400 /* accept on this netif */
401 return 1;
402 }
403 #endif /* LWIP_AUTOIP */
404 }
405 return 0;
406 }
407
408 /**
409 * This function is called by the network interface device driver when
410 * an IP packet is received. The function does the basic checks of the
411 * IP header such as packet size being at least larger than the header
412 * size etc. If the packet was not destined for us, the packet is
413 * forwarded (using ip_forward). The IP checksum is always checked.
414 *
415 * Finally, the packet is sent to the upper layer protocol input function.
416 *
417 * @param p the received IP packet (p->payload points to IP header)
418 * @param inp the netif on which this packet was received
419 * @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
420 * processed, but currently always returns ERR_OK)
421 */
422 err_t
ip4_input(struct pbuf * p,struct netif * inp)423 ip4_input(struct pbuf *p, struct netif *inp)
424 {
425 struct ip_hdr *iphdr;
426 struct netif *netif;
427 u16_t iphdr_hlen;
428 u16_t iphdr_len;
429 #if IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP
430 int check_ip_src = 1;
431 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP */
432
433 IP_STATS_INC(ip.recv);
434 MIB2_STATS_INC(mib2.ipinreceives);
435
436 /* identify the IP header */
437 iphdr = (struct ip_hdr *)p->payload;
438 if (IPH_V(iphdr) != 4) {
439 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", (u16_t)IPH_V(iphdr)));
440 ip4_debug_print(p);
441 pbuf_free(p);
442 IP_STATS_INC(ip.err);
443 IP_STATS_INC(ip.drop);
444 MIB2_STATS_INC(mib2.ipinhdrerrors);
445 return ERR_OK;
446 }
447
448 #ifdef LWIP_HOOK_IP4_INPUT
449 if (LWIP_HOOK_IP4_INPUT(p, inp)) {
450 /* the packet has been eaten */
451 return ERR_OK;
452 }
453 #endif
454
455 /* obtain IP header length in number of 32-bit words */
456 iphdr_hlen = IPH_HL(iphdr);
457 /* calculate IP header length in bytes */
458 iphdr_hlen *= 4;
459 /* obtain ip length in bytes */
460 iphdr_len = lwip_ntohs(IPH_LEN(iphdr));
461
462 /* Trim pbuf. This is especially required for packets < 60 bytes. */
463 if (iphdr_len < p->tot_len) {
464 pbuf_realloc(p, iphdr_len);
465 }
466
467 /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
468 if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len) || (iphdr_hlen < IP_HLEN)) {
469 if (iphdr_hlen < IP_HLEN) {
470 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
471 ("ip4_input: short IP header (%"U16_F" bytes) received, IP packet dropped\n", iphdr_hlen));
472 }
473 if (iphdr_hlen > p->len) {
474 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
475 ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
476 iphdr_hlen, p->len));
477 }
478 if (iphdr_len > p->tot_len) {
479 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
480 ("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
481 iphdr_len, p->tot_len));
482 }
483 /* free (drop) packet pbufs */
484 pbuf_free(p);
485 IP_STATS_INC(ip.lenerr);
486 IP_STATS_INC(ip.drop);
487 MIB2_STATS_INC(mib2.ipindiscards);
488 return ERR_OK;
489 }
490
491 /* verify checksum */
492 #if CHECKSUM_CHECK_IP
493 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_IP) {
494 if (inet_chksum(iphdr, iphdr_hlen) != 0) {
495
496 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
497 ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
498 ip4_debug_print(p);
499 pbuf_free(p);
500 IP_STATS_INC(ip.chkerr);
501 IP_STATS_INC(ip.drop);
502 MIB2_STATS_INC(mib2.ipinhdrerrors);
503 return ERR_OK;
504 }
505 }
506 #endif
507
508 /* copy IP addresses to aligned ip_addr_t */
509 ip_addr_copy_from_ip4(ip_data.current_iphdr_dest, iphdr->dest);
510 ip_addr_copy_from_ip4(ip_data.current_iphdr_src, iphdr->src);
511
512 /* match packet against an interface, i.e. is this packet for us? */
513 if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
514 #if LWIP_IGMP
515 if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, ip4_current_dest_addr()))) {
516 /* IGMP snooping switches need 0.0.0.0 to be allowed as source address (RFC 4541) */
517 ip4_addr_t allsystems;
518 IP4_ADDR(&allsystems, 224, 0, 0, 1);
519 if (ip4_addr_cmp(ip4_current_dest_addr(), &allsystems) &&
520 ip4_addr_isany(ip4_current_src_addr())) {
521 check_ip_src = 0;
522 }
523 netif = inp;
524 } else {
525 netif = NULL;
526 }
527 #else /* LWIP_IGMP */
528 if ((netif_is_up(inp)) && (!ip4_addr_isany_val(*netif_ip4_addr(inp)))) {
529 netif = inp;
530 } else {
531 netif = NULL;
532 }
533 #endif /* LWIP_IGMP */
534 } else {
535 /* start trying with inp. if that's not acceptable, start walking the
536 list of configured netifs. */
537 if (ip4_input_accept(inp)) {
538 netif = inp;
539 } else {
540 netif = NULL;
541 #if !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF
542 /* Packets sent to the loopback address must not be accepted on an
543 * interface that does not have the loopback address assigned to it,
544 * unless a non-loopback interface is used for loopback traffic. */
545 if (!ip4_addr_isloopback(ip4_current_dest_addr()))
546 #endif /* !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF */
547 {
548 #if !LWIP_SINGLE_NETIF
549 NETIF_FOREACH(netif) {
550 if (netif == inp) {
551 /* we checked that before already */
552 continue;
553 }
554 if (ip4_input_accept(netif)) {
555 break;
556 }
557 }
558 #endif /* !LWIP_SINGLE_NETIF */
559 }
560 }
561 }
562
563 #if IP_ACCEPT_LINK_LAYER_ADDRESSING
564 /* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
565 * using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
566 * According to RFC 1542 section 3.1.1, referred by RFC 2131).
567 *
568 * If you want to accept private broadcast communication while a netif is down,
569 * define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
570 *
571 * #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
572 */
573 if (netif == NULL) {
574 /* remote port is DHCP server? */
575 if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
576 struct udp_hdr *udphdr = (struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen);
577 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: UDP packet to DHCP client port %"U16_F"\n",
578 lwip_ntohs(udphdr->dest)));
579 if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
580 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: DHCP packet accepted.\n"));
581 netif = inp;
582 check_ip_src = 0;
583 }
584 }
585 }
586 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
587
588 /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
589 #if LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING
590 if (check_ip_src
591 #if IP_ACCEPT_LINK_LAYER_ADDRESSING
592 /* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
593 && !ip4_addr_isany_val(*ip4_current_src_addr())
594 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
595 )
596 #endif /* LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING */
597 {
598 if ((ip4_addr_isbroadcast(ip4_current_src_addr(), inp)) ||
599 (ip4_addr_ismulticast(ip4_current_src_addr()))) {
600 /* packet source is not valid */
601 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("ip4_input: packet source is not valid.\n"));
602 /* free (drop) packet pbufs */
603 pbuf_free(p);
604 IP_STATS_INC(ip.drop);
605 MIB2_STATS_INC(mib2.ipinaddrerrors);
606 MIB2_STATS_INC(mib2.ipindiscards);
607 return ERR_OK;
608 }
609 }
610
611 /* packet not for us? */
612 if (netif == NULL) {
613 /* packet not for us, route or discard */
614 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: packet not for us.\n"));
615 #if IP_FORWARD
616 /* non-broadcast packet? */
617 if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), inp)) {
618 /* try to forward IP packet on (other) interfaces */
619 ip4_forward(p, iphdr, inp);
620 } else
621 #endif /* IP_FORWARD */
622 {
623 IP_STATS_INC(ip.drop);
624 MIB2_STATS_INC(mib2.ipinaddrerrors);
625 MIB2_STATS_INC(mib2.ipindiscards);
626 }
627 pbuf_free(p);
628 return ERR_OK;
629 }
630 /* packet consists of multiple fragments? */
631 if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK | IP_MF)) != 0) {
632 #if IP_REASSEMBLY /* packet fragment reassembly code present? */
633 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",
634 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)));
635 /* reassemble the packet*/
636 p = ip4_reass(p);
637 /* packet not fully reassembled yet? */
638 if (p == NULL) {
639 return ERR_OK;
640 }
641 iphdr = (struct ip_hdr *)p->payload;
642 #else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
643 pbuf_free(p);
644 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
645 lwip_ntohs(IPH_OFFSET(iphdr))));
646 IP_STATS_INC(ip.opterr);
647 IP_STATS_INC(ip.drop);
648 /* unsupported protocol feature */
649 MIB2_STATS_INC(mib2.ipinunknownprotos);
650 return ERR_OK;
651 #endif /* IP_REASSEMBLY */
652 }
653
654 #if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
655
656 #if LWIP_IGMP
657 /* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
658 if ((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
659 #else
660 if (iphdr_hlen > IP_HLEN) {
661 #endif /* LWIP_IGMP */
662 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
663 pbuf_free(p);
664 IP_STATS_INC(ip.opterr);
665 IP_STATS_INC(ip.drop);
666 /* unsupported protocol feature */
667 MIB2_STATS_INC(mib2.ipinunknownprotos);
668 return ERR_OK;
669 }
670 #endif /* IP_OPTIONS_ALLOWED == 0 */
671
672 /* send to upper layers */
673 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: \n"));
674 ip4_debug_print(p);
675 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
676
677 ip_data.current_netif = netif;
678 ip_data.current_input_netif = inp;
679 ip_data.current_ip4_header = iphdr;
680 ip_data.current_ip_header_tot_len = IPH_HL(iphdr) * 4;
681
682 #if LWIP_RAW
683 /* raw input did not eat the packet? */
684 if (raw_input(p, inp) == 0)
685 #endif /* LWIP_RAW */
686 {
687 pbuf_header(p, -(s16_t)iphdr_hlen); /* Move to payload, no check necessary. */
688
689 switch (IPH_PROTO(iphdr)) {
690 #if LWIP_UDP
691 case IP_PROTO_UDP:
692 #if LWIP_UDPLITE
693 case IP_PROTO_UDPLITE:
694 #endif /* LWIP_UDPLITE */
695 MIB2_STATS_INC(mib2.ipindelivers);
696 udp_input(p, inp);
697 break;
698 #endif /* LWIP_UDP */
699 #if LWIP_TCP
700 case IP_PROTO_TCP:
701 MIB2_STATS_INC(mib2.ipindelivers);
702 tcp_input(p, inp);
703 break;
704 #endif /* LWIP_TCP */
705 #if LWIP_ICMP
706 case IP_PROTO_ICMP:
707 MIB2_STATS_INC(mib2.ipindelivers);
708 icmp_input(p, inp);
709 break;
710 #endif /* LWIP_ICMP */
711 #if LWIP_IGMP
712 case IP_PROTO_IGMP:
713 igmp_input(p, inp, ip4_current_dest_addr());
714 break;
715 #endif /* LWIP_IGMP */
716 default:
717 #if LWIP_ICMP
718 /* send ICMP destination protocol unreachable unless is was a broadcast */
719 if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), netif) &&
720 !ip4_addr_ismulticast(ip4_current_dest_addr())) {
721 pbuf_header_force(p, iphdr_hlen); /* Move to ip header, no check necessary. */
722 p->payload = iphdr;
723 icmp_dest_unreach(p, ICMP_DUR_PROTO);
724 }
725 #endif /* LWIP_ICMP */
726 pbuf_free(p);
727
728 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", (u16_t)IPH_PROTO(iphdr)));
729
730 IP_STATS_INC(ip.proterr);
731 IP_STATS_INC(ip.drop);
732 MIB2_STATS_INC(mib2.ipinunknownprotos);
733 }
734 }
735
736 /* @todo: this is not really necessary... */
737 ip_data.current_netif = NULL;
738 ip_data.current_input_netif = NULL;
739 ip_data.current_ip4_header = NULL;
740 ip_data.current_ip_header_tot_len = 0;
741 ip4_addr_set_any(ip4_current_src_addr());
742 ip4_addr_set_any(ip4_current_dest_addr());
743
744 return ERR_OK;
745 }
746
747 /**
748 * Sends an IP packet on a network interface. This function constructs
749 * the IP header and calculates the IP header checksum. If the source
750 * IP address is NULL, the IP address of the outgoing network
751 * interface is filled in as source address.
752 * If the destination IP address is LWIP_IP_HDRINCL, p is assumed to already
753 * include an IP header and p->payload points to it instead of the data.
754 *
755 * @param p the packet to send (p->payload points to the data, e.g. next
756 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
757 IP header and p->payload points to that IP header)
758 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
759 * IP address of the netif used to send is used as source address)
760 * @param dest the destination IP address to send the packet to
761 * @param ttl the TTL value to be set in the IP header
762 * @param tos the TOS value to be set in the IP header
763 * @param proto the PROTOCOL to be set in the IP header
764 * @param netif the netif on which to send this packet
765 * @return ERR_OK if the packet was sent OK
766 * ERR_BUF if p doesn't have enough space for IP/LINK headers
767 * returns errors returned by netif->output
768 *
769 * @note ip_id: RFC791 "some host may be able to simply use
770 * unique identifiers independent of destination"
771 */
772 err_t
773 ip4_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
774 u8_t ttl, u8_t tos,
775 u8_t proto, struct netif *netif)
776 {
777 #if IP_OPTIONS_SEND
778 return ip4_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
779 }
780
781 /**
782 * Same as ip_output_if() but with the possibility to include IP options:
783 *
784 * @ param ip_options pointer to the IP options, copied into the IP header
785 * @ param optlen length of ip_options
786 */
787 err_t
788 ip4_output_if_opt(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
789 u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
790 u16_t optlen)
791 {
792 #endif /* IP_OPTIONS_SEND */
793 const ip4_addr_t *src_used = src;
794 if (dest != LWIP_IP_HDRINCL) {
795 if (ip4_addr_isany(src)) {
796 src_used = netif_ip4_addr(netif);
797 }
798 }
799
800 #if IP_OPTIONS_SEND
801 return ip4_output_if_opt_src(p, src_used, dest, ttl, tos, proto, netif,
802 ip_options, optlen);
803 #else /* IP_OPTIONS_SEND */
804 return ip4_output_if_src(p, src_used, dest, ttl, tos, proto, netif);
805 #endif /* IP_OPTIONS_SEND */
806 }
807
808 /**
809 * Same as ip_output_if() but 'src' address is not replaced by netif address
810 * when it is 'any'.
811 */
812 err_t
813 ip4_output_if_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
814 u8_t ttl, u8_t tos,
815 u8_t proto, struct netif *netif)
816 {
817 #if IP_OPTIONS_SEND
818 return ip4_output_if_opt_src(p, src, dest, ttl, tos, proto, netif, NULL, 0);
819 }
820
821 /**
822 * Same as ip_output_if_opt() but 'src' address is not replaced by netif address
823 * when it is 'any'.
824 */
825 err_t
826 ip4_output_if_opt_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
827 u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
828 u16_t optlen)
829 {
830 #endif /* IP_OPTIONS_SEND */
831 struct ip_hdr *iphdr;
832 ip4_addr_t dest_addr;
833 #if CHECKSUM_GEN_IP_INLINE
834 u32_t chk_sum = 0;
835 #endif /* CHECKSUM_GEN_IP_INLINE */
836
837 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
838
839 MIB2_STATS_INC(mib2.ipoutrequests);
840
841 /* Should the IP header be generated or is it already included in p? */
842 if (dest != LWIP_IP_HDRINCL) {
843 u16_t ip_hlen = IP_HLEN;
844 #if IP_OPTIONS_SEND
845 u16_t optlen_aligned = 0;
846 if (optlen != 0) {
847 #if CHECKSUM_GEN_IP_INLINE
848 int i;
849 #endif /* CHECKSUM_GEN_IP_INLINE */
850 /* round up to a multiple of 4 */
851 optlen_aligned = ((optlen + 3) & ~3);
852 ip_hlen += optlen_aligned;
853 /* First write in the IP options */
854 if (pbuf_header(p, optlen_aligned)) {
855 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: not enough room for IP options in pbuf\n"));
856 IP_STATS_INC(ip.err);
857 MIB2_STATS_INC(mib2.ipoutdiscards);
858 return ERR_BUF;
859 }
860 MEMCPY(p->payload, ip_options, optlen);
861 if (optlen < optlen_aligned) {
862 /* zero the remaining bytes */
863 memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
864 }
865 #if CHECKSUM_GEN_IP_INLINE
866 for (i = 0; i < optlen_aligned/2; i++) {
867 chk_sum += ((u16_t*)p->payload)[i];
868 }
869 #endif /* CHECKSUM_GEN_IP_INLINE */
870 }
871 #endif /* IP_OPTIONS_SEND */
872 /* generate IP header */
873 if (pbuf_header(p, IP_HLEN)) {
874 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: not enough room for IP header in pbuf\n"));
875
876 IP_STATS_INC(ip.err);
877 MIB2_STATS_INC(mib2.ipoutdiscards);
878 return ERR_BUF;
879 }
880
881 iphdr = (struct ip_hdr *)p->payload;
882 LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
883 (p->len >= sizeof(struct ip_hdr)));
884
885 IPH_TTL_SET(iphdr, ttl);
886 IPH_PROTO_SET(iphdr, proto);
887 #if CHECKSUM_GEN_IP_INLINE
888 chk_sum += PP_NTOHS(proto | (ttl << 8));
889 #endif /* CHECKSUM_GEN_IP_INLINE */
890
891 /* dest cannot be NULL here */
892 ip4_addr_copy(iphdr->dest, *dest);
893 #if CHECKSUM_GEN_IP_INLINE
894 chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
895 chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
896 #endif /* CHECKSUM_GEN_IP_INLINE */
897
898 IPH_VHL_SET(iphdr, 4, ip_hlen / 4);
899 IPH_TOS_SET(iphdr, tos);
900 #if CHECKSUM_GEN_IP_INLINE
901 chk_sum += PP_NTOHS(tos | (iphdr->_v_hl << 8));
902 #endif /* CHECKSUM_GEN_IP_INLINE */
903 IPH_LEN_SET(iphdr, lwip_htons(p->tot_len));
904 #if CHECKSUM_GEN_IP_INLINE
905 chk_sum += iphdr->_len;
906 #endif /* CHECKSUM_GEN_IP_INLINE */
907 IPH_OFFSET_SET(iphdr, 0);
908 IPH_ID_SET(iphdr, lwip_htons(ip_id));
909 #if CHECKSUM_GEN_IP_INLINE
910 chk_sum += iphdr->_id;
911 #endif /* CHECKSUM_GEN_IP_INLINE */
912 ++ip_id;
913
914 if (src == NULL) {
915 ip4_addr_copy(iphdr->src, *IP4_ADDR_ANY4);
916 } else {
917 /* src cannot be NULL here */
918 ip4_addr_copy(iphdr->src, *src);
919 }
920
921 #if CHECKSUM_GEN_IP_INLINE
922 chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
923 chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
924 chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
925 chk_sum = (chk_sum >> 16) + chk_sum;
926 chk_sum = ~chk_sum;
927 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
928 iphdr->_chksum = (u16_t)chk_sum; /* network order */
929 }
930 #if LWIP_CHECKSUM_CTRL_PER_NETIF
931 else {
932 IPH_CHKSUM_SET(iphdr, 0);
933 }
934 #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF*/
935 #else /* CHECKSUM_GEN_IP_INLINE */
936 IPH_CHKSUM_SET(iphdr, 0);
937 #if CHECKSUM_GEN_IP
938 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
939 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
940 }
941 #endif /* CHECKSUM_GEN_IP */
942 #endif /* CHECKSUM_GEN_IP_INLINE */
943 } else {
944 /* IP header already included in p */
945 iphdr = (struct ip_hdr *)p->payload;
946 ip4_addr_copy(dest_addr, iphdr->dest);
947 dest = &dest_addr;
948 }
949
950 IP_STATS_INC(ip.xmit);
951
952 LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], (u16_t)netif->num));
953 ip4_debug_print(p);
954
955 #if ENABLE_LOOPBACK
956 if (ip4_addr_cmp(dest, netif_ip4_addr(netif))
957 #if !LWIP_HAVE_LOOPIF
958 || ip4_addr_isloopback(dest)
959 #endif /* !LWIP_HAVE_LOOPIF */
960 ) {
961 /* Packet to self, enqueue it for loopback */
962 LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
963 return netif_loop_output(netif, p);
964 }
965 #if LWIP_MULTICAST_TX_OPTIONS
966 if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
967 netif_loop_output(netif, p);
968 }
969 #endif /* LWIP_MULTICAST_TX_OPTIONS */
970 #endif /* ENABLE_LOOPBACK */
971 #if IP_FRAG
972 /* don't fragment if interface has mtu set to 0 [loopif] */
973 if (netif->mtu && (p->tot_len > netif->mtu)) {
974 return ip4_frag(p, netif, dest);
975 }
976 #endif /* IP_FRAG */
977
978 LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: call netif->output()\n"));
979 return netif->output(netif, p, dest);
980 }
981
982 /**
983 * Simple interface to ip_output_if. It finds the outgoing network
984 * interface and calls upon ip_output_if to do the actual work.
985 *
986 * @param p the packet to send (p->payload points to the data, e.g. next
987 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
988 IP header and p->payload points to that IP header)
989 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
990 * IP address of the netif used to send is used as source address)
991 * @param dest the destination IP address to send the packet to
992 * @param ttl the TTL value to be set in the IP header
993 * @param tos the TOS value to be set in the IP header
994 * @param proto the PROTOCOL to be set in the IP header
995 *
996 * @return ERR_RTE if no route is found
997 * see ip_output_if() for more return values
998 */
999 err_t
1000 ip4_output(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
1001 u8_t ttl, u8_t tos, u8_t proto)
1002 {
1003 struct netif *netif;
1004
1005 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
1006
1007 if ((netif = ip4_route_src(dest, src)) == NULL) {
1008 LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
1009 ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
1010 IP_STATS_INC(ip.rterr);
1011 return ERR_RTE;
1012 }
1013
1014 return ip4_output_if(p, src, dest, ttl, tos, proto, netif);
1015 }
1016
1017 #if LWIP_NETIF_HWADDRHINT
1018 /** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
1019 * before calling ip_output_if.
1020 *
1021 * @param p the packet to send (p->payload points to the data, e.g. next
1022 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
1023 IP header and p->payload points to that IP header)
1024 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
1025 * IP address of the netif used to send is used as source address)
1026 * @param dest the destination IP address to send the packet to
1027 * @param ttl the TTL value to be set in the IP header
1028 * @param tos the TOS value to be set in the IP header
1029 * @param proto the PROTOCOL to be set in the IP header
1030 * @param addr_hint address hint pointer set to netif->addr_hint before
1031 * calling ip_output_if()
1032 *
1033 * @return ERR_RTE if no route is found
1034 * see ip_output_if() for more return values
1035 */
1036 err_t
1037 ip4_output_hinted(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
1038 u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
1039 {
1040 struct netif *netif;
1041 err_t err;
1042
1043 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
1044
1045 if ((netif = ip4_route_src(dest, src)) == NULL) {
1046 LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
1047 ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
1048 IP_STATS_INC(ip.rterr);
1049 return ERR_RTE;
1050 }
1051
1052 NETIF_SET_HWADDRHINT(netif, addr_hint);
1053 err = ip4_output_if(p, src, dest, ttl, tos, proto, netif);
1054 NETIF_SET_HWADDRHINT(netif, NULL);
1055
1056 return err;
1057 }
1058 #endif /* LWIP_NETIF_HWADDRHINT*/
1059
1060 #if IP_DEBUG
1061 /* Print an IP header by using LWIP_DEBUGF
1062 * @param p an IP packet, p->payload pointing to the IP header
1063 */
1064 void
1065 ip4_debug_print(struct pbuf *p)
1066 {
1067 struct ip_hdr *iphdr = (struct ip_hdr *)p->payload;
1068
1069 LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
1070 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1071 LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" | 0x%02"X16_F" | %5"U16_F" | (v, hl, tos, len)\n",
1072 (u16_t)IPH_V(iphdr),
1073 (u16_t)IPH_HL(iphdr),
1074 (u16_t)IPH_TOS(iphdr),
1075 lwip_ntohs(IPH_LEN(iphdr))));
1076 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1077 LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" |%"U16_F"%"U16_F"%"U16_F"| %4"U16_F" | (id, flags, offset)\n",
1078 lwip_ntohs(IPH_ID(iphdr)),
1079 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 15 & 1),
1080 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 14 & 1),
1081 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 13 & 1),
1082 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)));
1083 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1084 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | 0x%04"X16_F" | (ttl, proto, chksum)\n",
1085 (u16_t)IPH_TTL(iphdr),
1086 (u16_t)IPH_PROTO(iphdr),
1087 lwip_ntohs(IPH_CHKSUM(iphdr))));
1088 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1089 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (src)\n",
1090 ip4_addr1_16(&iphdr->src),
1091 ip4_addr2_16(&iphdr->src),
1092 ip4_addr3_16(&iphdr->src),
1093 ip4_addr4_16(&iphdr->src)));
1094 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1095 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (dest)\n",
1096 ip4_addr1_16(&iphdr->dest),
1097 ip4_addr2_16(&iphdr->dest),
1098 ip4_addr3_16(&iphdr->dest),
1099 ip4_addr4_16(&iphdr->dest)));
1100 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1101 }
1102 #endif /* IP_DEBUG */
1103
1104 #endif /* LWIP_IPV4 */
1105