1 /**
2 * @file
3 * Implementation of raw protocol PCBs for low-level handling of
4 * different types of protocols besides (or overriding) those
5 * already available in lwIP.
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_RAW /* don't build if not configured for use in lwipopts.h */
44
45 #include "lwip/def.h"
46 #include "lwip/memp.h"
47 #include "lwip/ip_addr.h"
48 #include "lwip/netif.h"
49 #include "lwip/raw.h"
50 #include "lwip/stats.h"
51 #include "arch/perf.h"
52
53 #include <string.h>
54
55 /** The list of RAW PCBs */
56 static struct raw_pcb *raw_pcbs;
57
58 /**
59 * Determine if in incoming IP packet is covered by a RAW PCB
60 * and if so, pass it to a user-provided receive callback function.
61 *
62 * Given an incoming IP datagram (as a chain of pbufs) this function
63 * finds a corresponding RAW PCB and calls the corresponding receive
64 * callback function.
65 *
66 * @param p pbuf to be demultiplexed to a RAW PCB.
67 * @param inp network interface on which the datagram was received.
68 * @return - 1 if the packet has been eaten by a RAW PCB receive
69 * callback function. The caller MAY NOT not reference the
70 * packet any longer, and MAY NOT call pbuf_free().
71 * @return - 0 if packet is not eaten (pbuf is still referenced by the
72 * caller).
73 *
74 */
75 u8_t
raw_input(struct pbuf * p,struct netif * inp)76 raw_input(struct pbuf *p, struct netif *inp)
77 {
78 struct raw_pcb *pcb, *prev;
79 struct ip_hdr *iphdr;
80 s16_t proto;
81 u8_t eaten = 0;
82
83 LWIP_UNUSED_ARG(inp);
84
85 iphdr = (struct ip_hdr *)p->payload;
86 proto = IPH_PROTO(iphdr);
87
88 prev = NULL;
89 pcb = raw_pcbs;
90 /* loop through all raw pcbs until the packet is eaten by one */
91 /* this allows multiple pcbs to match against the packet by design */
92 while ((eaten == 0) && (pcb != NULL)) {
93 if ((pcb->protocol == proto) &&
94 (ip_addr_isany(&pcb->local_ip) ||
95 ip_addr_cmp(&(pcb->local_ip), ¤t_iphdr_dest))) {
96 #if IP_SOF_BROADCAST_RECV
97 /* broadcast filter? */
98 if ((pcb->so_options & SOF_BROADCAST) || !ip_addr_isbroadcast(¤t_iphdr_dest, inp))
99 #endif /* IP_SOF_BROADCAST_RECV */
100 {
101 /* receive callback function available? */
102 if (pcb->recv != NULL) {
103 /* the receive callback function did not eat the packet? */
104 if (pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr()) != 0) {
105 /* receive function ate the packet */
106 p = NULL;
107 eaten = 1;
108 if (prev != NULL) {
109 /* move the pcb to the front of raw_pcbs so that is
110 found faster next time */
111 prev->next = pcb->next;
112 pcb->next = raw_pcbs;
113 raw_pcbs = pcb;
114 }
115 }
116 }
117 /* no receive callback function was set for this raw PCB */
118 }
119 /* drop the packet */
120 }
121 prev = pcb;
122 pcb = pcb->next;
123 }
124 return eaten;
125 }
126
127 /**
128 * Bind a RAW PCB.
129 *
130 * @param pcb RAW PCB to be bound with a local address ipaddr.
131 * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to
132 * bind to all local interfaces.
133 *
134 * @return lwIP error code.
135 * - ERR_OK. Successful. No error occured.
136 * - ERR_USE. The specified IP address is already bound to by
137 * another RAW PCB.
138 *
139 * @see raw_disconnect()
140 */
141 err_t
raw_bind(struct raw_pcb * pcb,ip_addr_t * ipaddr)142 raw_bind(struct raw_pcb *pcb, ip_addr_t *ipaddr)
143 {
144 ip_addr_set(&pcb->local_ip, ipaddr);
145 return ERR_OK;
146 }
147
148 /**
149 * Connect an RAW PCB. This function is required by upper layers
150 * of lwip. Using the raw api you could use raw_sendto() instead
151 *
152 * This will associate the RAW PCB with the remote address.
153 *
154 * @param pcb RAW PCB to be connected with remote address ipaddr and port.
155 * @param ipaddr remote IP address to connect with.
156 *
157 * @return lwIP error code
158 *
159 * @see raw_disconnect() and raw_sendto()
160 */
161 err_t
raw_connect(struct raw_pcb * pcb,ip_addr_t * ipaddr)162 raw_connect(struct raw_pcb *pcb, ip_addr_t *ipaddr)
163 {
164 ip_addr_set(&pcb->remote_ip, ipaddr);
165 return ERR_OK;
166 }
167
168
169 /**
170 * Set the callback function for received packets that match the
171 * raw PCB's protocol and binding.
172 *
173 * The callback function MUST either
174 * - eat the packet by calling pbuf_free() and returning non-zero. The
175 * packet will not be passed to other raw PCBs or other protocol layers.
176 * - not free the packet, and return zero. The packet will be matched
177 * against further PCBs and/or forwarded to another protocol layers.
178 *
179 * @return non-zero if the packet was free()d, zero if the packet remains
180 * available for others.
181 */
182 void
raw_recv(struct raw_pcb * pcb,raw_recv_fn recv,void * recv_arg)183 raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg)
184 {
185 /* remember recv() callback and user data */
186 pcb->recv = recv;
187 pcb->recv_arg = recv_arg;
188 }
189
190 /**
191 * Send the raw IP packet to the given address. Note that actually you cannot
192 * modify the IP headers (this is inconsistent with the receive callback where
193 * you actually get the IP headers), you can only specify the IP payload here.
194 * It requires some more changes in lwIP. (there will be a raw_send() function
195 * then.)
196 *
197 * @param pcb the raw pcb which to send
198 * @param p the IP payload to send
199 * @param ipaddr the destination address of the IP packet
200 *
201 */
202 err_t
raw_sendto(struct raw_pcb * pcb,struct pbuf * p,ip_addr_t * ipaddr)203 raw_sendto(struct raw_pcb *pcb, struct pbuf *p, ip_addr_t *ipaddr)
204 {
205 err_t err;
206 struct netif *netif;
207 ip_addr_t *src_ip;
208 struct pbuf *q; /* q will be sent down the stack */
209
210 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n"));
211
212 /* not enough space to add an IP header to first pbuf in given p chain? */
213 if (pbuf_header(p, IP_HLEN)) {
214 /* allocate header in new pbuf */
215 q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
216 /* new header pbuf could not be allocated? */
217 if (q == NULL) {
218 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("raw_sendto: could not allocate header\n"));
219 return ERR_MEM;
220 }
221 if (p->tot_len != 0) {
222 /* chain header q in front of given pbuf p */
223 pbuf_chain(q, p);
224 }
225 /* { first pbuf q points to header pbuf } */
226 LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
227 } else {
228 /* first pbuf q equals given pbuf */
229 q = p;
230 if(pbuf_header(q, -IP_HLEN)) {
231 LWIP_ASSERT("Can't restore header we just removed!", 0);
232 return ERR_MEM;
233 }
234 }
235
236 if ((netif = ip_route(ipaddr)) == NULL) {
237 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
238 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
239 /* free any temporary header pbuf allocated by pbuf_header() */
240 if (q != p) {
241 pbuf_free(q);
242 }
243 return ERR_RTE;
244 }
245
246 #if IP_SOF_BROADCAST
247 /* broadcast filter? */
248 if (((pcb->so_options & SOF_BROADCAST) == 0) && ip_addr_isbroadcast(ipaddr, netif)) {
249 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
250 /* free any temporary header pbuf allocated by pbuf_header() */
251 if (q != p) {
252 pbuf_free(q);
253 }
254 return ERR_VAL;
255 }
256 #endif /* IP_SOF_BROADCAST */
257
258 if (ip_addr_isany(&pcb->local_ip)) {
259 /* use outgoing network interface IP address as source address */
260 src_ip = &(netif->ip_addr);
261 } else {
262 /* use RAW PCB local IP address as source address */
263 src_ip = &(pcb->local_ip);
264 }
265
266 #if LWIP_NETIF_HWADDRHINT
267 netif->addr_hint = &(pcb->addr_hint);
268 #endif /* LWIP_NETIF_HWADDRHINT*/
269 err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif);
270 #if LWIP_NETIF_HWADDRHINT
271 netif->addr_hint = NULL;
272 #endif /* LWIP_NETIF_HWADDRHINT*/
273
274 /* did we chain a header earlier? */
275 if (q != p) {
276 /* free the header */
277 pbuf_free(q);
278 }
279 return err;
280 }
281
282 /**
283 * Send the raw IP packet to the address given by raw_connect()
284 *
285 * @param pcb the raw pcb which to send
286 * @param p the IP payload to send
287 *
288 */
289 err_t
raw_send(struct raw_pcb * pcb,struct pbuf * p)290 raw_send(struct raw_pcb *pcb, struct pbuf *p)
291 {
292 return raw_sendto(pcb, p, &pcb->remote_ip);
293 }
294
295 /**
296 * Remove an RAW PCB.
297 *
298 * @param pcb RAW PCB to be removed. The PCB is removed from the list of
299 * RAW PCB's and the data structure is freed from memory.
300 *
301 * @see raw_new()
302 */
303 void
raw_remove(struct raw_pcb * pcb)304 raw_remove(struct raw_pcb *pcb)
305 {
306 struct raw_pcb *pcb2;
307 /* pcb to be removed is first in list? */
308 if (raw_pcbs == pcb) {
309 /* make list start at 2nd pcb */
310 raw_pcbs = raw_pcbs->next;
311 /* pcb not 1st in list */
312 } else {
313 for(pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
314 /* find pcb in raw_pcbs list */
315 if (pcb2->next != NULL && pcb2->next == pcb) {
316 /* remove pcb from list */
317 pcb2->next = pcb->next;
318 }
319 }
320 }
321 memp_free(MEMP_RAW_PCB, pcb);
322 }
323
324 /**
325 * Create a RAW PCB.
326 *
327 * @return The RAW PCB which was created. NULL if the PCB data structure
328 * could not be allocated.
329 *
330 * @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP)
331 *
332 * @see raw_remove()
333 */
334 struct raw_pcb *
raw_new(u8_t proto)335 raw_new(u8_t proto)
336 {
337 struct raw_pcb *pcb;
338
339 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_new\n"));
340
341 pcb = (struct raw_pcb *)memp_malloc(MEMP_RAW_PCB);
342 /* could allocate RAW PCB? */
343 if (pcb != NULL) {
344 /* initialize PCB to all zeroes */
345 memset(pcb, 0, sizeof(struct raw_pcb));
346 pcb->protocol = proto;
347 pcb->ttl = RAW_TTL;
348 pcb->next = raw_pcbs;
349 raw_pcbs = pcb;
350 }
351 return pcb;
352 }
353
354 #endif /* LWIP_RAW */
355