/[lwip]/lwip/src/core/raw.c
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revision 1.1 by kieranm, Wed Aug 20 16:46:16 2003 UTC revision 1.2 by likewise, Fri Nov 14 13:19:01 2003 UTC
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1    /**
2     * @file
3     * Raw Access module
4     *
5     */
6    /*
7     * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
8     * All rights reserved.
9     *
10     * Redistribution and use in source and binary forms, with or without modification,
11     * are permitted provided that the following conditions are met:
12     *
13     * 1. Redistributions of source code must retain the above copyright notice,
14     *    this list of conditions and the following disclaimer.
15     * 2. Redistributions in binary form must reproduce the above copyright notice,
16     *    this list of conditions and the following disclaimer in the documentation
17     *    and/or other materials provided with the distribution.
18     * 3. The name of the author may not be used to endorse or promote products
19     *    derived from this software without specific prior written permission.
20     *
21     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
22     * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23     * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
24     * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25     * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
26     * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27     * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28     * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
29     * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
30     * OF SUCH DAMAGE.
31     *
32     * This file is part of the lwIP TCP/IP stack.
33     *
34     * Author: Adam Dunkels <adam@sics.se>
35     *
36     */
37    
38    
39    /* raw.c
40     *
41     * The code for the Raw Access to the IP
42     *
43     */
44    
45    #include "lwip/opt.h"
46    
47    #include "lwip/def.h"
48    #include "lwip/memp.h"
49    #include "lwip/inet.h"
50    #include "lwip/netif.h"
51    #include "lwip/ip_addr.h"
52    #include "lwip/raw.h"
53    
54    #include "lwip/stats.h"
55    
56    #include "arch/perf.h"
57    #include "lwip/snmp.h"
58    
59    #if LWIP_RAW
60    /* The list of RAW PCBs */
61    
62    static struct raw_pcb *raw_pcbs = NULL;
63    
64    
65    void
66    raw_init(void)
67    {
68      raw_pcbs = NULL;
69    }
70    
71    /**
72     * Determine if in incoming IP packet is covered by a RAW pcb and
73     * and process it if possible
74     *
75     * Given an incoming IP datagram (as a chain of pbufs) this function
76     * finds a corresponding RAW PCB and
77     *
78     * @param pbuf pbuf to be demultiplexed to a RAW PCB.
79     * @param netif network interface on which the datagram was received.
80     * @return 0 if packet is not eated (pbuf needs to be freed then)
81     *         or 1 if the packet has been eaten (pbuf needs not to be freed
82     *         then)
83     *
84     */
85    int
86    raw_input(struct pbuf *p, struct netif *inp)
87    {
88      struct raw_pcb *pcb;
89      struct ip_hdr *iphdr;
90      int proto;
91      int rc = 0;
92    
93      iphdr = p->payload;
94      proto = IPH_PROTO(iphdr);
95    
96      for(pcb = raw_pcbs; pcb != NULL; pcb = pcb->next) {
97        if (pcb->protocol == proto) {
98          if (pcb->recv) {
99            if (!pcb->recv(pcb->recv_arg, pcb, p, &(iphdr->src)))
100              return 0;
101          }
102          pbuf_free(p);
103          rc = 1;
104          break;
105        }
106      }
107      return rc;
108    }
109    
110    /**
111     * Bind a RAW PCB.
112     *
113     * @param pcb RAW PCB to be bound with a local address ipaddr.
114     * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to
115     * bind to all local interfaces.
116     *
117     * @return lwIP error code.
118     * - ERR_OK. Successful. No error occured.
119     * - ERR_USE. The specified ipaddr is already bound to by
120     * another RAW PCB.
121     *
122     * @see raw_disconnect()
123     */
124    err_t
125    raw_bind(struct raw_pcb *pcb, struct ip_addr *ipaddr)
126    {
127      ip_addr_set(&pcb->local_ip, ipaddr);
128      return ERR_OK;
129    }
130    
131    /**
132     * Connect an RAW PCB. This function is required by upper layers
133     * of lwip. Using the raw api you could use raw_send_to() instead
134     *
135     * This will associate the RAW PCB with the remote address.
136     *
137     * @param pcb RAW PCB to be connected with remote address ipaddr and port.
138     * @param ipaddr remote IP address to connect with.
139     *
140     * @return lwIP error code
141     *
142     * @see raw_disconnect() and raw_send_to()
143     */
144    err_t
145    raw_connect(struct raw_pcb *pcb, struct ip_addr *ipaddr)
146    {
147      ip_addr_set(&pcb->remote_ip, ipaddr);
148      return ERR_OK;
149    }
150    
151    
152    /**
153     * Set the callback function if a RAW packet with the pcb's protocol
154     * is received. If the callback function returns a value unequal 0
155     * the raw packet is "eaten" and not forwarded to any other raw pcb
156     * including lwip itself
157     */
158    void
159    raw_recv(struct raw_pcb *pcb,
160             int (* recv)(void *arg, struct raw_pcb *upcb, struct pbuf *p,
161                          struct ip_addr *addr),
162             void *recv_arg)
163    {
164      /* remember recv() callback and user data */
165      pcb->recv = recv;
166      pcb->recv_arg = recv_arg;
167    }
168    
169    /**
170     * Send the raw IP packet to the given address. Note that actually you cannot
171     * modify the IP headers (this is inconsitent with the receive callback where
172     * you actually get the IP headers), you can only specifiy the ip payload here.
173     * It requires some more changes in LWIP. (there will be a raw_send() function
174     * then)
175     *
176     * @param pcb the raw pcb which to send
177     * @param p the ip payload to send
178     * @param ipaddr the destination address of the whole IP packet
179     *
180     */
181    err_t
182    raw_send_to(struct raw_pcb *pcb, struct pbuf *p, struct ip_addr *ipaddr)
183    {
184      err_t err;
185      struct netif *netif;
186      struct ip_addr *src_ip;
187      struct pbuf *q; /* q will be sent down the stack */
188      
189      LWIP_DEBUGF(RAW_DEBUG | DBG_TRACE | 3, ("raw_send_to\n"));
190      
191      /* not enough space to add an IP header to first pbuf in given p chain? */
192      if (pbuf_header(p, IP_HLEN)) {
193        /* allocate header in new pbuf */
194        q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
195        /* new header pbuf could not be allocated? */
196        if (q == NULL) {
197          LWIP_DEBUGF(RAW_DEBUG | DBG_TRACE | 2, ("raw_send_to: could not allocate header\n"));
198          return ERR_MEM;
199        }
200        /* chain header q in front of given pbuf p */
201        pbuf_chain(q, p);
202        /* { first pbuf q points to header pbuf } */
203        LWIP_DEBUGF(RAW_DEBUG, ("raw_send_to: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
204      }  else {
205        /* first pbuf q equals given pbuf */
206        q = p;
207        pbuf_header(q, -IP_HLEN);
208      }
209      
210      if ((netif = ip_route(ipaddr)) == NULL) {
211        LWIP_DEBUGF(RAW_DEBUG | 1, ("raw_send_to: No route to 0x%lx\n", ipaddr->addr));
212    #if RAW_STATS
213        /*    ++lwip_stats.raw.rterr;*/
214    #endif /* RAW_STATS */
215        if (q != p) {
216          pbuf_free(q);
217        }
218        return ERR_RTE;
219      }
220    
221      if (ip_addr_isany(&pcb->local_ip)) {
222        /* use outgoing network interface IP address as source address */
223        src_ip = &(netif->ip_addr);
224      } else {
225        /* use RAW PCB local IP address as source address */
226        src_ip = &(pcb->local_ip);
227      }
228    
229      err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif);
230    
231      /* did we chain a header earlier? */
232      if (q != p) {
233        /* free the header */
234        pbuf_free(q);
235      }
236      return err;
237    }
238    
239    /**
240     * Send the raw IP packet to the address given by raw_connect()
241     *
242     * @param pcb the raw pcb which to send
243     * @param p the ip payload to send
244     * @param ipaddr the destination address of the whole IP packet
245     *
246     */
247    err_t
248    raw_send(struct raw_pcb *pcb, struct pbuf *p)
249    {
250      return raw_send_to(pcb,p,&pcb->remote_ip);
251    }
252    
253    /**
254     * Remove an RAW PCB.
255     *
256     * @param pcb RAW PCB to be removed. The PCB is removed from the list of
257     * RAW PCB's and the data structure is freed from memory.
258     *
259     * @see raw_new()
260     */
261    void
262    raw_remove(struct raw_pcb *pcb)
263    {
264      struct raw_pcb *pcb2;
265      /* pcb to be removed is first in list? */
266      if (raw_pcbs == pcb) {
267        /* make list start at 2nd pcb */
268        raw_pcbs = raw_pcbs->next;
269      /* pcb not 1st in list */
270      } else for(pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
271        /* find pcb in raw_pcbs list */
272        if (pcb2->next != NULL && pcb2->next == pcb) {
273          /* remove pcb from list */
274          pcb2->next = pcb->next;
275        }
276      }
277      memp_free(MEMP_RAW_PCB, pcb);
278    }
279    
280    /**
281     * Create a RAW PCB.
282     *
283     * @return The RAW PCB which was created. NULL if the PCB data structure
284     * could not be allocated.
285     *
286     * @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP)
287     *
288     * @see raw_remove()
289     */
290    struct raw_pcb *
291    raw_new(u16_t proto) {
292      struct raw_pcb *pcb;
293    
294      LWIP_DEBUGF(RAW_DEBUG | DBG_TRACE | 3, ("raw_new\n"));
295    
296      pcb = memp_malloc(MEMP_RAW_PCB);
297      /* could allocate RAW PCB? */
298      if (pcb != NULL) {
299        /* initialize PCB to all zeroes */
300        memset(pcb, 0, sizeof(struct raw_pcb));
301        pcb->protocol = proto;
302        pcb->ttl = RAW_TTL;
303        pcb->next = raw_pcbs;
304        raw_pcbs = pcb;
305      }
306    
307      return pcb;
308    }
309    
310    #endif /* LWIP_RAW */

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