Contiki-NG
ip64-addrmap.c
1 /*
2  * Copyright (c) 2012, Thingsquare, http://www.thingsquare.com/.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  *
14  * 3. Neither the name of the copyright holder nor the names of its
15  * contributors may be used to endorse or promote products derived
16  * from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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27  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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29  * OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  */
32 #include "ip64/ip64-addrmap.h"
33 
34 #include "lib/memb.h"
35 #include "lib/list.h"
36 
37 #include "ip64-conf.h"
38 
39 #include "lib/random.h"
40 
41 #include <string.h>
42 
43 #ifdef IP64_ADDRMAP_CONF_ENTRIES
44 #define NUM_ENTRIES IP64_ADDRMAP_CONF_ENTRIES
45 #else /* IP64_ADDRMAP_CONF_ENTRIES */
46 #define NUM_ENTRIES 32
47 #endif /* IP64_ADDRMAP_CONF_ENTRIES */
48 
49 MEMB(entrymemb, struct ip64_addrmap_entry, NUM_ENTRIES);
50 LIST(entrylist);
51 
52 #define FIRST_MAPPED_PORT 10000
53 #define LAST_MAPPED_PORT 20000
54 static uint16_t mapped_port = FIRST_MAPPED_PORT;
55 
56 #define printf(...)
57 
58 /*---------------------------------------------------------------------------*/
59 struct ip64_addrmap_entry *
60 ip64_addrmap_list(void)
61 {
62  return list_head(entrylist);
63 }
64 /*---------------------------------------------------------------------------*/
65 void
66 ip64_addrmap_init(void)
67 {
68  memb_init(&entrymemb);
69  list_init(entrylist);
70  mapped_port = FIRST_MAPPED_PORT;
71 }
72 /*---------------------------------------------------------------------------*/
73 static void
74 check_age(void)
75 {
76  struct ip64_addrmap_entry *m;
77 
78  /* Walk through the list of address mappings, throw away the ones
79  that are too old. */
80  m = list_head(entrylist);
81  while(m != NULL) {
82  if(timer_expired(&m->timer)) {
83  list_remove(entrylist, m);
84  memb_free(&entrymemb, m);
85  m = list_head(entrylist);
86  } else {
87  m = list_item_next(m);
88  }
89  }
90 }
91 /*---------------------------------------------------------------------------*/
92 static int
93 recycle(void)
94 {
95  /* Find the oldest recyclable mapping and remove it. */
96  struct ip64_addrmap_entry *m, *oldest;
97 
98  /* Walk through the list of address mappings, throw away the ones
99  that are too old. */
100 
101  oldest = NULL;
102  for(m = list_head(entrylist);
103  m != NULL;
104  m = list_item_next(m)) {
105  if(m->flags & FLAGS_RECYCLABLE) {
106  if(oldest == NULL) {
107  oldest = m;
108  } else {
109  if(timer_remaining(&m->timer) <
110  timer_remaining(&oldest->timer)) {
111  oldest = m;
112  }
113  }
114  }
115  }
116 
117  /* If we found an oldest recyclable entry, remove it and return
118  non-zero. */
119  if(oldest != NULL) {
120  list_remove(entrylist, oldest);
121  memb_free(&entrymemb, oldest);
122  return 1;
123  }
124 
125  return 0;
126 }
127 /*---------------------------------------------------------------------------*/
128 struct ip64_addrmap_entry *
129 ip64_addrmap_lookup(const uip_ip6addr_t *ip6addr,
130  uint16_t ip6port,
131  const uip_ip4addr_t *ip4addr,
132  uint16_t ip4port,
133  uint8_t protocol)
134 {
135  struct ip64_addrmap_entry *m;
136 
137  printf("lookup ip4port %d ip6port %d\n", uip_htons(ip4port),
138  uip_htons(ip6port));
139  check_age();
140  for(m = list_head(entrylist); m != NULL; m = list_item_next(m)) {
141  printf("protocol %d %d, ip4port %d %d, ip6port %d %d, ip4 %d ip6 %d\n",
142  m->protocol, protocol,
143  m->ip4port, ip4port,
144  m->ip6port, ip6port,
145  uip_ip4addr_cmp(&m->ip4addr, ip4addr),
146  uip_ip6addr_cmp(&m->ip6addr, ip6addr));
147  if(m->protocol == protocol &&
148  m->ip4port == ip4port &&
149  m->ip6port == ip6port &&
150  uip_ip4addr_cmp(&m->ip4addr, ip4addr) &&
151  uip_ip6addr_cmp(&m->ip6addr, ip6addr)) {
152  m->ip6to4++;
153  return m;
154  }
155  }
156  return NULL;
157 }
158 /*---------------------------------------------------------------------------*/
159 struct ip64_addrmap_entry *
160 ip64_addrmap_lookup_port(uint16_t mapped_port, uint8_t protocol)
161 {
162  struct ip64_addrmap_entry *m;
163 
164  check_age();
165  for(m = list_head(entrylist); m != NULL; m = list_item_next(m)) {
166  printf("mapped port %d %d, protocol %d %d\n",
167  m->mapped_port, mapped_port,
168  m->protocol, protocol);
169  if(m->mapped_port == mapped_port &&
170  m->protocol == protocol) {
171  m->ip4to6++;
172  return m;
173  }
174  }
175  return NULL;
176 }
177 /*---------------------------------------------------------------------------*/
178 static void
179 increase_mapped_port(void)
180 {
181  mapped_port = (random_rand() % (LAST_MAPPED_PORT - FIRST_MAPPED_PORT)) +
182  FIRST_MAPPED_PORT;
183 }
184 /*---------------------------------------------------------------------------*/
185 struct ip64_addrmap_entry *
186 ip64_addrmap_create(const uip_ip6addr_t *ip6addr,
187  uint16_t ip6port,
188  const uip_ip4addr_t *ip4addr,
189  uint16_t ip4port,
190  uint8_t protocol)
191 {
192  struct ip64_addrmap_entry *m;
193 
194  check_age();
195  m = memb_alloc(&entrymemb);
196  if(m == NULL) {
197  /* We could not allocate an entry, try to recycle one and try to
198  allocate again. */
199  if(recycle()) {
200  m = memb_alloc(&entrymemb);
201  }
202  }
203  if(m != NULL) {
204  uip_ip4addr_copy(&m->ip4addr, ip4addr);
205  m->ip4port = ip4port;
206  uip_ip6addr_copy(&m->ip6addr, ip6addr);
207  m->ip6port = ip6port;
208  m->protocol = protocol;
209  m->flags = FLAGS_NONE;
210  m->ip6to4 = 1;
211  m->ip4to6 = 0;
212  timer_set(&m->timer, 0);
213 
214  /* Pick a new, unused local port. First make sure that the
215  mapped_port number does not belong to any active connection. If
216  so, we keep increasing the mapped_port until we're free. */
217  {
218  struct ip64_addrmap_entry *n;
219  n = list_head(entrylist);
220  while(n != NULL) {
221  if(n->mapped_port == mapped_port) {
222  increase_mapped_port();
223  n = list_head(entrylist);
224  } else {
225  n = list_item_next(m);
226  }
227  }
228  }
229  m->mapped_port = mapped_port;
230  increase_mapped_port();
231 
232  list_add(entrylist, m);
233  return m;
234  }
235  return NULL;
236 }
237 /*---------------------------------------------------------------------------*/
238 void
239 ip64_addrmap_set_lifetime(struct ip64_addrmap_entry *e,
240  clock_time_t time)
241 {
242  if(e != NULL) {
243  timer_set(&e->timer, time);
244  }
245 }
246 /*---------------------------------------------------------------------------*/
247 void
248 ip64_addrmap_set_recycleble(struct ip64_addrmap_entry *e)
249 {
250  if(e != NULL) {
251  e->flags |= FLAGS_RECYCLABLE;
252  }
253 }
254 /*---------------------------------------------------------------------------*/
#define uip_ip4addr_cmp(addr1, addr2)
Compare two IP addresses.
Definition: uip.h:1044
void timer_set(struct timer *t, clock_time_t interval)
Set a timer.
Definition: timer.c:64
clock_time_t timer_remaining(struct timer *t)
The time until the timer expires.
Definition: timer.c:143
int memb_free(struct memb *m, void *ptr)
Deallocate a memory block from a memory block previously declared with MEMB().
Definition: memb.c:78
Representation of an IP address.
Definition: uip.h:95
uint16_t uip_htons(uint16_t val)
Convert a 16-bit quantity from host byte order to network byte order.
Definition: uip6.c:2334
Linked list manipulation routines.
void * list_head(list_t list)
Get a pointer to the first element of a list.
Definition: list.c:82
int timer_expired(struct timer *t)
Check if a timer has expired.
Definition: timer.c:123
Memory block allocation routines.
void list_add(list_t list, void *item)
Add an item at the end of a list.
Definition: list.c:142
void list_init(list_t list)
Initialize a list.
Definition: list.c:65
#define LIST(name)
Declare a linked list.
Definition: list.h:89
void * memb_alloc(struct memb *m)
Allocate a memory block from a block of memory declared with MEMB().
Definition: memb.c:59
void memb_init(struct memb *m)
Initialize a memory block that was declared with MEMB().
Definition: memb.c:52
unsigned short random_rand(void)
Generates a new random number using the cc2538 RNG.
Definition: random.c:58
void list_remove(list_t list, void *item)
Remove a specific element from a list.
Definition: list.c:237
void * list_item_next(void *item)
Get the next item following this item.
Definition: list.c:322
#define MEMB(name, structure, num)
Declare a memory block.
Definition: memb.h:90