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_net_eq(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_eq(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, loopback 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 /* Take care of setting checksums to 0 for checksum offload netifs */
373 if (CHECKSUM_GEN_IP || NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP)) {
374 IPH_CHKSUM_SET(iphdr, 0);
375 }
376 switch (IPH_PROTO(iphdr)) {
377 #if LWIP_UDP
378 #if LWIP_UDPLITE
379 case IP_PROTO_UDPLITE:
380 #endif
381 case IP_PROTO_UDP:
382 if (CHECKSUM_GEN_UDP || NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_UDP)) {
383 ((struct udp_hdr *)((u8_t *)iphdr + IPH_HL_BYTES(iphdr)))->chksum = 0;
384 }
385 break;
386 #endif
387 #if LWIP_TCP
388 case IP_PROTO_TCP:
389 if (CHECKSUM_GEN_TCP || NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_TCP)) {
390 ((struct tcp_hdr *)((u8_t *)iphdr + IPH_HL_BYTES(iphdr)))->chksum = 0;
391 }
392 break;
393 #endif
394 #if LWIP_ICMP
395 case IP_PROTO_ICMP:
396 if (CHECKSUM_GEN_ICMP || NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP)) {
397 ((struct icmp_hdr *)((u8_t *)iphdr + IPH_HL_BYTES(iphdr)))->chksum = 0;
398 }
399 break;
400 #endif
401 default:
402 /* there's really nothing to do here other than satisfying 'switch-default' */
403 break;
404 }
405
406 LWIP_DEBUGF(IP_DEBUG, ("ip4_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
407 ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
408 ip4_addr3_16(ip4_current_dest_addr()), ip4_addr4_16(ip4_current_dest_addr())));
409
410 IP_STATS_INC(ip.fw);
411 MIB2_STATS_INC(mib2.ipforwdatagrams);
412 IP_STATS_INC(ip.xmit);
413
414 PERF_STOP("ip4_forward");
415 /* don't fragment if interface has mtu set to 0 [loopif] */
416 if (netif->mtu && (p->tot_len > netif->mtu)) {
417 if ((IPH_OFFSET(iphdr) & PP_NTOHS(IP_DF)) == 0) {
418 #if IP_FRAG
419 ip4_frag(p, netif, ip4_current_dest_addr());
420 #else /* IP_FRAG */
421 /* @todo: send ICMP Destination Unreachable code 13 "Communication administratively prohibited"? */
422 #endif /* IP_FRAG */
423 } else {
424 #if LWIP_ICMP
425 /* send ICMP Destination Unreachable code 4: "Fragmentation Needed and DF Set" */
426 icmp_dest_unreach(p, ICMP_DUR_FRAG);
427 #endif /* LWIP_ICMP */
428 }
429 return;
430 }
431 /* transmit pbuf on chosen interface */
432 netif->output(netif, p, ip4_current_dest_addr());
433 return;
434 return_noroute:
435 MIB2_STATS_INC(mib2.ipoutnoroutes);
436 }
437 #endif /* IP_FORWARD */
438
439 /** Return true if the current input packet should be accepted on this netif */
440 static int
441 ip4_input_accept(struct netif *netif)
442 {
443 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",
444 ip4_addr_get_u32(ip4_current_dest_addr()), ip4_addr_get_u32(netif_ip4_addr(netif)),
445 ip4_addr_get_u32(ip4_current_dest_addr()) & ip4_addr_get_u32(netif_ip4_netmask(netif)),
446 ip4_addr_get_u32(netif_ip4_addr(netif)) & ip4_addr_get_u32(netif_ip4_netmask(netif)),
447 ip4_addr_get_u32(ip4_current_dest_addr()) & ~ip4_addr_get_u32(netif_ip4_netmask(netif))));
448
449 /* interface is up and configured? */
450 if ((netif_is_up(netif)) && (!ip4_addr_isany_val(*netif_ip4_addr(netif)))) {
451 /* unicast to this interface address? */
452 if (ip4_addr_eq(ip4_current_dest_addr(), netif_ip4_addr(netif)) ||
453 /* or broadcast on this interface network address? */
454 ip4_addr_isbroadcast(ip4_current_dest_addr(), netif)
455 #if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF
456 || (ip4_addr_get_u32(ip4_current_dest_addr()) == PP_HTONL(IPADDR_LOOPBACK))
457 #endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */
458 ) {
459 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: packet accepted on interface %c%c\n",
460 netif->name[0], netif->name[1]));
461 /* accept on this netif */
462 return 1;
463 }
464 #if LWIP_AUTOIP
465 /* connections to link-local addresses must persist after changing
466 the netif's address (RFC3927 ch. 1.9) */
467 if (autoip_accept_packet(netif, ip4_current_dest_addr())) {
468 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: LLA packet accepted on interface %c%c\n",
469 netif->name[0], netif->name[1]));
470 /* accept on this netif */
471 return 1;
472 }
473 #endif /* LWIP_AUTOIP */
474 }
475 return 0;
476 }
477
478 /**
479 * This function is called by the network interface device driver when
480 * an IP packet is received. The function does the basic checks of the
481 * IP header such as packet size being at least larger than the header
482 * size etc. If the packet was not destined for us, the packet is
483 * forwarded (using ip_forward). The IP checksum is always checked.
484 *
485 * Finally, the packet is sent to the upper layer protocol input function.
486 *
487 * @param p the received IP packet (p->payload points to IP header)
488 * @param inp the netif on which this packet was received
489 * @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
490 * processed, but currently always returns ERR_OK)
491 */
492 err_t
493 ip4_input(struct pbuf *p, struct netif *inp)
494 {
495 const struct ip_hdr *iphdr;
496 struct netif *netif;
497 u16_t iphdr_hlen;
498 u16_t iphdr_len;
499 #if IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP
500 int check_ip_src = 1;
501 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING || LWIP_IGMP */
502 #if LWIP_RAW
503 raw_input_state_t raw_status;
504 #endif /* LWIP_RAW */
505
506 LWIP_ASSERT_CORE_LOCKED();
507
508 IP_STATS_INC(ip.recv);
509 MIB2_STATS_INC(mib2.ipinreceives);
510
511 #ifdef LOSCFG_NET_CONTAINER
512 struct net_group *group = get_net_group_from_netif(inp);
513 #endif
514
515 /* identify the IP header */
516 iphdr = (struct ip_hdr *)p->payload;
517 if (IPH_V(iphdr) != 4) {
518 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", (u16_t)IPH_V(iphdr)));
519 ip4_debug_print(p);
520 pbuf_free(p);
521 IP_STATS_INC(ip.err);
522 IP_STATS_INC(ip.drop);
523 MIB2_STATS_INC(mib2.ipinhdrerrors);
524 return ERR_OK;
525 }
526
527 #ifdef LWIP_HOOK_IP4_INPUT
528 if (LWIP_HOOK_IP4_INPUT(p, inp)) {
529 /* the packet has been eaten */
530 return ERR_OK;
531 }
532 #endif
533
534 /* obtain IP header length in bytes */
535 iphdr_hlen = IPH_HL_BYTES(iphdr);
536 /* obtain ip length in bytes */
537 iphdr_len = lwip_ntohs(IPH_LEN(iphdr));
538
539 /* Trim pbuf. This is especially required for packets < 60 bytes. */
540 if (iphdr_len < p->tot_len) {
541 pbuf_realloc(p, iphdr_len);
542 }
543
544 /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
545 if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len) || (iphdr_hlen < IP_HLEN)) {
546 if (iphdr_hlen < IP_HLEN) {
547 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
548 ("ip4_input: short IP header (%"U16_F" bytes) received, IP packet dropped\n", iphdr_hlen));
549 }
550 if (iphdr_hlen > p->len) {
551 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
552 ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
553 iphdr_hlen, p->len));
554 }
555 if (iphdr_len > p->tot_len) {
556 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
557 ("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
558 iphdr_len, p->tot_len));
559 }
560 /* free (drop) packet pbufs */
561 pbuf_free(p);
562 IP_STATS_INC(ip.lenerr);
563 IP_STATS_INC(ip.drop);
564 MIB2_STATS_INC(mib2.ipindiscards);
565 return ERR_OK;
566 }
567
568 /* verify checksum */
569 #if CHECKSUM_CHECK_IP
570 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_IP) {
571 if (inet_chksum(iphdr, iphdr_hlen) != 0) {
572
573 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
574 ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
575 ip4_debug_print(p);
576 pbuf_free(p);
577 IP_STATS_INC(ip.chkerr);
578 IP_STATS_INC(ip.drop);
579 MIB2_STATS_INC(mib2.ipinhdrerrors);
580 return ERR_OK;
581 }
582 }
583 #endif
584
585 /* copy IP addresses to aligned ip_addr_t */
586 ip_addr_copy_from_ip4(ip_data.current_iphdr_dest, iphdr->dest);
587 ip_addr_copy_from_ip4(ip_data.current_iphdr_src, iphdr->src);
588
589 /* match packet against an interface, i.e. is this packet for us? */
590 if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
591 #if LWIP_IGMP
592 if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, ip4_current_dest_addr()))) {
593 /* IGMP snooping switches need 0.0.0.0 to be allowed as source address (RFC 4541) */
594 ip4_addr_t allsystems;
595 IP4_ADDR(&allsystems, 224, 0, 0, 1);
596 if (ip4_addr_eq(ip4_current_dest_addr(), &allsystems) &&
597 ip4_addr_isany(ip4_current_src_addr())) {
598 check_ip_src = 0;
599 }
600 netif = inp;
601 } else {
602 netif = NULL;
603 }
604 #else /* LWIP_IGMP */
605 if ((netif_is_up(inp)) && (!ip4_addr_isany_val(*netif_ip4_addr(inp)))) {
606 netif = inp;
607 } else {
608 netif = NULL;
609 }
610 #endif /* LWIP_IGMP */
611 } else {
612 /* start trying with inp. if that's not acceptable, start walking the
613 list of configured netifs. */
614 if (ip4_input_accept(inp)) {
615 netif = inp;
616 } else {
617 netif = NULL;
618 #if !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF
619 /* Packets sent to the loopback address must not be accepted on an
620 * interface that does not have the loopback address assigned to it,
621 * unless a non-loopback interface is used for loopback traffic. */
622 if (!ip4_addr_isloopback(ip4_current_dest_addr()))
623 #endif /* !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF */
624 {
625 #if !LWIP_SINGLE_NETIF
626 #ifdef LOSCFG_NET_CONTAINER
627 NETIF_FOREACH(netif, group) {
628 #else
629 NETIF_FOREACH(netif) {
630 #endif
631 if (netif == inp) {
632 /* we checked that before already */
633 continue;
634 }
635 if (ip4_input_accept(netif)) {
636 break;
637 }
638 }
639 #endif /* !LWIP_SINGLE_NETIF */
640 }
641 }
642 }
643
644 #if IP_ACCEPT_LINK_LAYER_ADDRESSING
645 /* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
646 * using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
647 * According to RFC 1542 section 3.1.1, referred by RFC 2131).
648 *
649 * If you want to accept private broadcast communication while a netif is down,
650 * define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
651 *
652 * #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
653 */
654 if (netif == NULL) {
655 /* remote port is DHCP server? */
656 if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
657 const struct udp_hdr *udphdr = (const struct udp_hdr *)((const u8_t *)iphdr + iphdr_hlen);
658 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: UDP packet to DHCP client port %"U16_F"\n",
659 lwip_ntohs(udphdr->dest)));
660 if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
661 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: DHCP packet accepted.\n"));
662 netif = inp;
663 check_ip_src = 0;
664 }
665 }
666 }
667 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
668
669 /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
670 #if LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING
671 if (check_ip_src
672 #if IP_ACCEPT_LINK_LAYER_ADDRESSING
673 /* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
674 && !ip4_addr_isany_val(*ip4_current_src_addr())
675 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
676 )
677 #endif /* LWIP_IGMP || IP_ACCEPT_LINK_LAYER_ADDRESSING */
678 {
679 if ((ip4_addr_isbroadcast(ip4_current_src_addr(), inp)) ||
680 (ip4_addr_ismulticast(ip4_current_src_addr()))) {
681 /* packet source is not valid */
682 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("ip4_input: packet source is not valid.\n"));
683 /* free (drop) packet pbufs */
684 pbuf_free(p);
685 IP_STATS_INC(ip.drop);
686 MIB2_STATS_INC(mib2.ipinaddrerrors);
687 MIB2_STATS_INC(mib2.ipindiscards);
688 return ERR_OK;
689 }
690 }
691
692 /* packet not for us? */
693 if (netif == NULL) {
694 /* packet not for us, route or discard */
695 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip4_input: packet not for us.\n"));
696 #if IP_FORWARD
697 /* non-broadcast packet? */
698 if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), inp)) {
699 /* try to forward IP packet on (other) interfaces */
700 ip4_forward(p, (struct ip_hdr *)p->payload, inp);
701 } else
702 #endif /* IP_FORWARD */
703 {
704 IP_STATS_INC(ip.drop);
705 MIB2_STATS_INC(mib2.ipinaddrerrors);
706 MIB2_STATS_INC(mib2.ipindiscards);
707 }
708 pbuf_free(p);
709 return ERR_OK;
710 }
711 /* packet consists of multiple fragments? */
712 if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK | IP_MF)) != 0) {
713 #if IP_REASSEMBLY /* packet fragment reassembly code present? */
714 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",
715 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)));
716 /* reassemble the packet*/
717 p = ip4_reass(p);
718 /* packet not fully reassembled yet? */
719 if (p == NULL) {
720 return ERR_OK;
721 }
722 iphdr = (const struct ip_hdr *)p->payload;
723 #else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
724 pbuf_free(p);
725 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
726 lwip_ntohs(IPH_OFFSET(iphdr))));
727 IP_STATS_INC(ip.opterr);
728 IP_STATS_INC(ip.drop);
729 /* unsupported protocol feature */
730 MIB2_STATS_INC(mib2.ipinunknownprotos);
731 return ERR_OK;
732 #endif /* IP_REASSEMBLY */
733 }
734
735 #if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
736
737 #if LWIP_IGMP
738 /* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
739 if ((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
740 #else
741 if (iphdr_hlen > IP_HLEN) {
742 #endif /* LWIP_IGMP */
743 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
744 pbuf_free(p);
745 IP_STATS_INC(ip.opterr);
746 IP_STATS_INC(ip.drop);
747 /* unsupported protocol feature */
748 MIB2_STATS_INC(mib2.ipinunknownprotos);
749 return ERR_OK;
750 }
751 #endif /* IP_OPTIONS_ALLOWED == 0 */
752
753 /* send to upper layers */
754 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: \n"));
755 ip4_debug_print(p);
756 LWIP_DEBUGF(IP_DEBUG, ("ip4_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
757
758 ip_data.current_netif = netif;
759 ip_data.current_input_netif = inp;
760 ip_data.current_ip4_header = iphdr;
761 ip_data.current_ip_header_tot_len = IPH_HL_BYTES(iphdr);
762
763 #if LWIP_RAW
764 /* raw input did not eat the packet? */
765 raw_status = raw_input(p, inp);
766 if (raw_status != RAW_INPUT_EATEN)
767 #endif /* LWIP_RAW */
768 {
769 pbuf_remove_header(p, iphdr_hlen); /* Move to payload, no check necessary. */
770
771 switch (IPH_PROTO(iphdr)) {
772 #if LWIP_UDP
773 case IP_PROTO_UDP:
774 #if LWIP_UDPLITE
775 case IP_PROTO_UDPLITE:
776 #endif /* LWIP_UDPLITE */
777 MIB2_STATS_INC(mib2.ipindelivers);
778 udp_input(p, inp);
779 break;
780 #endif /* LWIP_UDP */
781 #if LWIP_TCP
782 case IP_PROTO_TCP:
783 MIB2_STATS_INC(mib2.ipindelivers);
784 tcp_input(p, inp);
785 break;
786 #endif /* LWIP_TCP */
787 #if LWIP_ICMP
788 case IP_PROTO_ICMP:
789 MIB2_STATS_INC(mib2.ipindelivers);
790 icmp_input(p, inp);
791 break;
792 #endif /* LWIP_ICMP */
793 #if LWIP_IGMP
794 case IP_PROTO_IGMP:
795 igmp_input(p, inp, ip4_current_dest_addr());
796 break;
797 #endif /* LWIP_IGMP */
798 default:
799 #if LWIP_RAW
800 if (raw_status == RAW_INPUT_DELIVERED) {
801 MIB2_STATS_INC(mib2.ipindelivers);
802 } else
803 #endif /* LWIP_RAW */
804 {
805 #if LWIP_ICMP
806 /* send ICMP destination protocol unreachable unless is was a broadcast */
807 if (!ip4_addr_isbroadcast(ip4_current_dest_addr(), netif) &&
808 !ip4_addr_ismulticast(ip4_current_dest_addr())) {
809 pbuf_header_force(p, (s16_t)iphdr_hlen); /* Move to ip header, no check necessary. */
810 icmp_dest_unreach(p, ICMP_DUR_PROTO);
811 }
812 #endif /* LWIP_ICMP */
813
814 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", (u16_t)IPH_PROTO(iphdr)));
815
816 IP_STATS_INC(ip.proterr);
817 IP_STATS_INC(ip.drop);
818 MIB2_STATS_INC(mib2.ipinunknownprotos);
819 }
820 pbuf_free(p);
821 break;
822 }
823 }
824
825 /* @todo: this is not really necessary... */
826 ip_data.current_netif = NULL;
827 ip_data.current_input_netif = NULL;
828 ip_data.current_ip4_header = NULL;
829 ip_data.current_ip_header_tot_len = 0;
830 ip4_addr_set_any(ip4_current_src_addr());
831 ip4_addr_set_any(ip4_current_dest_addr());
832
833 return ERR_OK;
834 }
835
836 /**
837 * Sends an IP packet on a network interface. This function constructs
838 * the IP header and calculates the IP header checksum. If the source
839 * IP address is NULL, the IP address of the outgoing network
840 * interface is filled in as source address.
841 * If the destination IP address is LWIP_IP_HDRINCL, p is assumed to already
842 * include an IP header and p->payload points to it instead of the data.
843 *
844 * @param p the packet to send (p->payload points to the data, e.g. next
845 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
846 IP header and p->payload points to that IP header)
847 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
848 * IP address of the netif used to send is used as source address)
849 * @param dest the destination IP address to send the packet to
850 * @param ttl the TTL value to be set in the IP header
851 * @param tos the TOS value to be set in the IP header
852 * @param proto the PROTOCOL to be set in the IP header
853 * @param netif the netif on which to send this packet
854 * @return ERR_OK if the packet was sent OK
855 * ERR_BUF if p doesn't have enough space for IP/LINK headers
856 * returns errors returned by netif->output
857 *
858 * @note ip_id: RFC791 "some host may be able to simply use
859 * unique identifiers independent of destination"
860 */
861 err_t
862 ip4_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
863 u8_t ttl, u8_t tos,
864 u8_t proto, struct netif *netif)
865 {
866 #if IP_OPTIONS_SEND
867 return ip4_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
868 }
869
870 /**
871 * Same as ip_output_if() but with the possibility to include IP options:
872 *
873 * @ param ip_options pointer to the IP options, copied into the IP header
874 * @ param optlen length of ip_options
875 */
876 err_t
877 ip4_output_if_opt(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
878 u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
879 u16_t optlen)
880 {
881 #endif /* IP_OPTIONS_SEND */
882 const ip4_addr_t *src_used = src;
883 if (dest != LWIP_IP_HDRINCL) {
884 if (ip4_addr_isany(src)) {
885 src_used = netif_ip4_addr(netif);
886 }
887 }
888
889 #if IP_OPTIONS_SEND
890 return ip4_output_if_opt_src(p, src_used, dest, ttl, tos, proto, netif,
891 ip_options, optlen);
892 #else /* IP_OPTIONS_SEND */
893 return ip4_output_if_src(p, src_used, dest, ttl, tos, proto, netif);
894 #endif /* IP_OPTIONS_SEND */
895 }
896
897 /**
898 * Same as ip_output_if() but 'src' address is not replaced by netif address
899 * when it is 'any'.
900 */
901 err_t
902 ip4_output_if_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
903 u8_t ttl, u8_t tos,
904 u8_t proto, struct netif *netif)
905 {
906 #if IP_OPTIONS_SEND
907 return ip4_output_if_opt_src(p, src, dest, ttl, tos, proto, netif, NULL, 0);
908 }
909
910 /**
911 * Same as ip_output_if_opt() but 'src' address is not replaced by netif address
912 * when it is 'any'.
913 */
914 err_t
915 ip4_output_if_opt_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
916 u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
917 u16_t optlen)
918 {
919 #endif /* IP_OPTIONS_SEND */
920 struct ip_hdr *iphdr;
921 ip4_addr_t dest_addr;
922 #if CHECKSUM_GEN_IP_INLINE
923 u32_t chk_sum = 0;
924 #endif /* CHECKSUM_GEN_IP_INLINE */
925
926 LWIP_ASSERT_CORE_LOCKED();
927 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
928
929 MIB2_STATS_INC(mib2.ipoutrequests);
930
931 /* Should the IP header be generated or is it already included in p? */
932 if (dest != LWIP_IP_HDRINCL) {
933 u16_t ip_hlen = IP_HLEN;
934 #if IP_OPTIONS_SEND
935 u16_t optlen_aligned = 0;
936 if (optlen != 0) {
937 #if CHECKSUM_GEN_IP_INLINE
938 int i;
939 #endif /* CHECKSUM_GEN_IP_INLINE */
940 if (optlen > (IP_HLEN_MAX - IP_HLEN)) {
941 /* optlen too long */
942 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: optlen too long\n"));
943 IP_STATS_INC(ip.err);
944 MIB2_STATS_INC(mib2.ipoutdiscards);
945 return ERR_VAL;
946 }
947 /* round up to a multiple of 4 */
948 optlen_aligned = (u16_t)((optlen + 3) & ~3);
949 ip_hlen = (u16_t)(ip_hlen + optlen_aligned);
950 /* First write in the IP options */
951 if (pbuf_add_header(p, optlen_aligned)) {
952 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output_if_opt: not enough room for IP options in pbuf\n"));
953 IP_STATS_INC(ip.err);
954 MIB2_STATS_INC(mib2.ipoutdiscards);
955 return ERR_BUF;
956 }
957 MEMCPY(p->payload, ip_options, optlen);
958 if (optlen < optlen_aligned) {
959 /* zero the remaining bytes */
960 memset(((char *)p->payload) + optlen, 0, (size_t)(optlen_aligned - optlen));
961 }
962 #if CHECKSUM_GEN_IP_INLINE
963 for (i = 0; i < optlen_aligned / 2; i++) {
964 chk_sum += ((u16_t *)p->payload)[i];
965 }
966 #endif /* CHECKSUM_GEN_IP_INLINE */
967 }
968 #endif /* IP_OPTIONS_SEND */
969 /* generate IP header */
970 if (pbuf_add_header(p, IP_HLEN)) {
971 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: not enough room for IP header in pbuf\n"));
972
973 IP_STATS_INC(ip.err);
974 MIB2_STATS_INC(mib2.ipoutdiscards);
975 return ERR_BUF;
976 }
977
978 iphdr = (struct ip_hdr *)p->payload;
979 LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
980 (p->len >= sizeof(struct ip_hdr)));
981
982 IPH_TTL_SET(iphdr, ttl);
983 IPH_PROTO_SET(iphdr, proto);
984 #if CHECKSUM_GEN_IP_INLINE
985 chk_sum += PP_NTOHS(proto | (ttl << 8));
986 #endif /* CHECKSUM_GEN_IP_INLINE */
987
988 /* dest cannot be NULL here */
989 ip4_addr_copy(iphdr->dest, *dest);
990 #if CHECKSUM_GEN_IP_INLINE
991 chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
992 chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
993 #endif /* CHECKSUM_GEN_IP_INLINE */
994
995 IPH_VHL_SET(iphdr, 4, ip_hlen / 4);
996 IPH_TOS_SET(iphdr, tos);
997 #if CHECKSUM_GEN_IP_INLINE
998 chk_sum += PP_NTOHS(tos | (iphdr->_v_hl << 8));
999 #endif /* CHECKSUM_GEN_IP_INLINE */
1000 IPH_LEN_SET(iphdr, lwip_htons(p->tot_len));
1001 #if CHECKSUM_GEN_IP_INLINE
1002 chk_sum += iphdr->_len;
1003 #endif /* CHECKSUM_GEN_IP_INLINE */
1004 IPH_OFFSET_SET(iphdr, 0);
1005 IPH_ID_SET(iphdr, lwip_htons(ip_id));
1006 #if CHECKSUM_GEN_IP_INLINE
1007 chk_sum += iphdr->_id;
1008 #endif /* CHECKSUM_GEN_IP_INLINE */
1009 ++ip_id;
1010
1011 if (src == NULL) {
1012 ip4_addr_copy(iphdr->src, *IP4_ADDR_ANY4);
1013 } else {
1014 /* src cannot be NULL here */
1015 ip4_addr_copy(iphdr->src, *src);
1016 }
1017
1018 #if CHECKSUM_GEN_IP_INLINE
1019 chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
1020 chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
1021 chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
1022 chk_sum = (chk_sum >> 16) + chk_sum;
1023 chk_sum = ~chk_sum;
1024 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
1025 iphdr->_chksum = (u16_t)chk_sum; /* network order */
1026 }
1027 #if LWIP_CHECKSUM_CTRL_PER_NETIF
1028 else {
1029 IPH_CHKSUM_SET(iphdr, 0);
1030 }
1031 #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF*/
1032 #else /* CHECKSUM_GEN_IP_INLINE */
1033 IPH_CHKSUM_SET(iphdr, 0);
1034 #if CHECKSUM_GEN_IP
1035 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
1036 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
1037 }
1038 #endif /* CHECKSUM_GEN_IP */
1039 #endif /* CHECKSUM_GEN_IP_INLINE */
1040 } else {
1041 /* IP header already included in p */
1042 if (p->len < IP_HLEN) {
1043 LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip4_output: LWIP_IP_HDRINCL but pbuf is too short\n"));
1044 IP_STATS_INC(ip.err);
1045 MIB2_STATS_INC(mib2.ipoutdiscards);
1046 return ERR_BUF;
1047 }
1048 iphdr = (struct ip_hdr *)p->payload;
1049 ip4_addr_copy(dest_addr, iphdr->dest);
1050 dest = &dest_addr;
1051 }
1052
1053 IP_STATS_INC(ip.xmit);
1054
1055 LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], (u16_t)netif->num));
1056 ip4_debug_print(p);
1057
1058 #if ENABLE_LOOPBACK
1059 if (ip4_addr_eq(dest, netif_ip4_addr(netif))
1060 #if !LWIP_HAVE_LOOPIF
1061 || ip4_addr_isloopback(dest)
1062 #endif /* !LWIP_HAVE_LOOPIF */
1063 ) {
1064 /* Packet to self, enqueue it for loopback */
1065 LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()\n"));
1066 return netif_loop_output(netif, p);
1067 }
1068 #if LWIP_MULTICAST_TX_OPTIONS
1069 if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
1070 netif_loop_output(netif, p);
1071 }
1072 #endif /* LWIP_MULTICAST_TX_OPTIONS */
1073 #endif /* ENABLE_LOOPBACK */
1074 #if IP_FRAG
1075 /* don't fragment if interface has mtu set to 0 [loopif] */
1076 if (netif->mtu && (p->tot_len > netif->mtu)) {
1077 return ip4_frag(p, netif, dest);
1078 }
1079 #endif /* IP_FRAG */
1080
1081 LWIP_DEBUGF(IP_DEBUG, ("ip4_output_if: call netif->output()\n"));
1082 return netif->output(netif, p, dest);
1083 }
1084
1085 /**
1086 * Simple interface to ip_output_if. It finds the outgoing network
1087 * interface and calls upon ip_output_if to do the actual work.
1088 *
1089 * @param p the packet to send (p->payload points to the data, e.g. next
1090 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
1091 IP header and p->payload points to that IP header)
1092 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
1093 * IP address of the netif used to send is used as source address)
1094 * @param dest the destination IP address to send the packet to
1095 * @param ttl the TTL value to be set in the IP header
1096 * @param tos the TOS value to be set in the IP header
1097 * @param proto the PROTOCOL to be set in the IP header
1098 *
1099 * @return ERR_RTE if no route is found
1100 * see ip_output_if() for more return values
1101 */
1102 err_t
1103 ip4_output(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
1104 u8_t ttl, u8_t tos, u8_t proto)
1105 {
1106 struct netif *netif;
1107
1108 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
1109 #ifdef LOSCFG_NET_CONTAINER
1110 struct net_group *group = get_curr_process_net_group();
1111
1112 if ((netif = ip4_route_src(src, dest, group)) == NULL) {
1113 #else
1114 if ((netif = ip4_route_src(src, dest)) == NULL) {
1115 #endif
1116 LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
1117 ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
1118 IP_STATS_INC(ip.rterr);
1119 return ERR_RTE;
1120 }
1121
1122 return ip4_output_if(p, src, dest, ttl, tos, proto, netif);
1123 }
1124
1125 #if LWIP_NETIF_USE_HINTS
1126 /** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
1127 * before calling ip_output_if.
1128 *
1129 * @param p the packet to send (p->payload points to the data, e.g. next
1130 protocol header; if dest == LWIP_IP_HDRINCL, p already includes an
1131 IP header and p->payload points to that IP header)
1132 * @param src the source IP address to send from (if src == IP4_ADDR_ANY, the
1133 * IP address of the netif used to send is used as source address)
1134 * @param dest the destination IP address to send the packet to
1135 * @param ttl the TTL value to be set in the IP header
1136 * @param tos the TOS value to be set in the IP header
1137 * @param proto the PROTOCOL to be set in the IP header
1138 * @param netif_hint netif output hint pointer set to netif->hint before
1139 * calling ip_output_if()
1140 *
1141 * @return ERR_RTE if no route is found
1142 * see ip_output_if() for more return values
1143 */
1144 err_t
1145 ip4_output_hinted(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
1146 u8_t ttl, u8_t tos, u8_t proto, struct netif_hint *netif_hint)
1147 {
1148 struct netif *netif;
1149 err_t err;
1150
1151 LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
1152
1153 if ((netif = ip4_route_src(src, dest)) == NULL) {
1154 LWIP_DEBUGF(IP_DEBUG, ("ip4_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
1155 ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
1156 IP_STATS_INC(ip.rterr);
1157 return ERR_RTE;
1158 }
1159
1160 NETIF_SET_HINTS(netif, netif_hint);
1161 err = ip4_output_if(p, src, dest, ttl, tos, proto, netif);
1162 NETIF_RESET_HINTS(netif);
1163
1164 return err;
1165 }
1166 #endif /* LWIP_NETIF_USE_HINTS*/
1167
1168 #if IP_DEBUG
1169 /* Print an IP header by using LWIP_DEBUGF
1170 * @param p an IP packet, p->payload pointing to the IP header
1171 */
1172 void
1173 ip4_debug_print(struct pbuf *p)
1174 {
1175 struct ip_hdr *iphdr = (struct ip_hdr *)p->payload;
1176
1177 LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
1178 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1179 LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" | 0x%02"X16_F" | %5"U16_F" | (v, hl, tos, len)\n",
1180 (u16_t)IPH_V(iphdr),
1181 (u16_t)IPH_HL(iphdr),
1182 (u16_t)IPH_TOS(iphdr),
1183 lwip_ntohs(IPH_LEN(iphdr))));
1184 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1185 LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" |%"U16_F"%"U16_F"%"U16_F"| %4"U16_F" | (id, flags, offset)\n",
1186 lwip_ntohs(IPH_ID(iphdr)),
1187 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 15 & 1),
1188 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 14 & 1),
1189 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) >> 13 & 1),
1190 (u16_t)(lwip_ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)));
1191 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1192 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | 0x%04"X16_F" | (ttl, proto, chksum)\n",
1193 (u16_t)IPH_TTL(iphdr),
1194 (u16_t)IPH_PROTO(iphdr),
1195 lwip_ntohs(IPH_CHKSUM(iphdr))));
1196 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1197 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (src)\n",
1198 ip4_addr1_16_val(iphdr->src),
1199 ip4_addr2_16_val(iphdr->src),
1200 ip4_addr3_16_val(iphdr->src),
1201 ip4_addr4_16_val(iphdr->src)));
1202 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1203 LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (dest)\n",
1204 ip4_addr1_16_val(iphdr->dest),
1205 ip4_addr2_16_val(iphdr->dest),
1206 ip4_addr3_16_val(iphdr->dest),
1207 ip4_addr4_16_val(iphdr->dest)));
1208 LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
1209 }
1210 #endif /* IP_DEBUG */
1211
1212 #endif /* LWIP_IPV4 */
1213