Commit | Line | Data |
---|---|---|
794f2398 SE |
1 | /* The 'ipset' data structure and related algorithms in this file were |
2 | inspired by the 'ipaddr.py' library from Cendio Systems AB. */ | |
c215a4bc IJ |
3 | /* |
4 | * This file is part of secnet. | |
5 | * See README for full list of copyright holders. | |
6 | * | |
7 | * secnet is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version d of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * secnet is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * version 3 along with secnet; if not, see | |
19 | * https://www.gnu.org/licenses/gpl.html. | |
20 | */ | |
794f2398 | 21 | |
7138d0c5 | 22 | #include "secnet.h" |
59230b9b IJ |
23 | #include <limits.h> |
24 | #include <assert.h> | |
7138d0c5 | 25 | #include <stdio.h> |
3b83c932 | 26 | #include <string.h> |
794f2398 | 27 | #include "ipaddr.h" |
c9c047dc | 28 | #include "util.h" |
794f2398 SE |
29 | |
30 | #define DEFAULT_ALLOC 2 | |
31 | #define EXTEND_ALLOC_BY 4 | |
32 | ||
33 | struct subnet_list *subnet_list_new(void) | |
34 | { | |
35 | struct subnet_list *r; | |
b7886fd4 | 36 | NEW(r); |
794f2398 SE |
37 | r->entries=0; |
38 | r->alloc=DEFAULT_ALLOC; | |
b4ececfc | 39 | NEW_ARY(r->list,r->alloc); |
794f2398 SE |
40 | return r; |
41 | } | |
42 | ||
43 | void subnet_list_free(struct subnet_list *a) | |
44 | { | |
45 | if (a->list) free(a->list); | |
46 | free(a); | |
47 | } | |
48 | ||
1caa23ff | 49 | static void subnet_list_set_len(struct subnet_list *a, int32_t l) |
794f2398 | 50 | { |
1caa23ff | 51 | int32_t na; |
794f2398 SE |
52 | |
53 | if (l>a->alloc) { | |
2f9fa75f | 54 | assert(a->alloc < INT_MAX-EXTEND_ALLOC_BY); |
794f2398 | 55 | na=a->alloc+EXTEND_ALLOC_BY; |
2f9fa75f | 56 | REALLOC_ARY(a->list,na); |
794f2398 | 57 | a->alloc=na; |
794f2398 SE |
58 | } |
59 | a->entries=l; | |
60 | } | |
61 | ||
1caa23ff | 62 | void subnet_list_append(struct subnet_list *a, uint32_t prefix, int len) |
794f2398 SE |
63 | { |
64 | struct subnet *sn; | |
59230b9b | 65 | assert(a->entries < INT_MAX); |
794f2398 SE |
66 | subnet_list_set_len(a,a->entries+1); |
67 | sn=&a->list[a->entries-1]; | |
68 | sn->prefix=prefix; | |
69 | sn->len=len; | |
70 | sn->mask=len?(0xffffffff << (32-len)):0; | |
71 | } | |
7138d0c5 | 72 | |
794f2398 SE |
73 | struct ipset *ipset_new(void) |
74 | { | |
75 | struct ipset *r; | |
b7886fd4 | 76 | NEW(r); |
794f2398 SE |
77 | r->l=0; |
78 | r->a=DEFAULT_ALLOC; | |
952f601f | 79 | NEW_ARY(r->d,r->a); |
794f2398 SE |
80 | return r; |
81 | } | |
7138d0c5 | 82 | |
794f2398 | 83 | void ipset_free(struct ipset *a) |
7138d0c5 | 84 | { |
794f2398 SE |
85 | if (a->d) free(a->d); |
86 | free(a); | |
7138d0c5 SE |
87 | } |
88 | ||
794f2398 SE |
89 | #ifdef DEBUG |
90 | static void ipset_dump(struct ipset *a, string_t name) | |
7138d0c5 | 91 | { |
1caa23ff | 92 | int32_t i; |
794f2398 SE |
93 | |
94 | printf("%s: ",name); | |
95 | for (i=0; i<a->l; i++) { | |
96 | printf("[%08x-%08x] ",a->d[i].a,a->d[i].b); | |
7138d0c5 | 97 | } |
794f2398 | 98 | printf("\n"); |
7138d0c5 | 99 | } |
794f2398 | 100 | #endif |
7138d0c5 | 101 | |
794f2398 | 102 | struct ipset *ipset_from_subnet(struct subnet s) |
7138d0c5 | 103 | { |
794f2398 SE |
104 | struct ipset *r; |
105 | ||
106 | r=ipset_new(); | |
107 | r->l=1; | |
108 | r->d[0].a=s.prefix; | |
109 | r->d[0].b=s.prefix | (~s.mask); | |
110 | return r; | |
7138d0c5 SE |
111 | } |
112 | ||
794f2398 | 113 | struct ipset *ipset_from_subnet_list(struct subnet_list *l) |
7138d0c5 | 114 | { |
794f2398 | 115 | struct ipset *r, *a, *b; |
1caa23ff | 116 | int32_t i; |
7138d0c5 | 117 | |
794f2398 SE |
118 | r=ipset_new(); |
119 | for (i=0; i<l->entries; i++) { | |
120 | a=ipset_from_subnet(l->list[i]); | |
121 | b=ipset_union(r,a); | |
122 | ipset_free(a); | |
123 | ipset_free(r); | |
124 | r=b; | |
7138d0c5 | 125 | } |
794f2398 | 126 | return r; |
7138d0c5 SE |
127 | } |
128 | ||
1caa23ff | 129 | static void ipset_set_len(struct ipset *a, int32_t l) |
794f2398 | 130 | { |
1caa23ff | 131 | int32_t na; |
794f2398 SE |
132 | |
133 | if (l>a->a) { | |
59230b9b | 134 | assert(a->a < INT_MAX-EXTEND_ALLOC_BY); |
794f2398 | 135 | na=a->a+EXTEND_ALLOC_BY; |
2f9fa75f | 136 | REALLOC_ARY(a->d,na); |
794f2398 | 137 | a->a=na; |
794f2398 SE |
138 | } |
139 | a->l=l; | |
140 | } | |
141 | ||
142 | static void ipset_append_range(struct ipset *a, struct iprange r) | |
143 | { | |
144 | ipset_set_len(a,a->l+1); | |
145 | a->d[a->l-1]=r; | |
146 | } | |
147 | ||
794f2398 SE |
148 | struct ipset *ipset_union(struct ipset *a, struct ipset *b) |
149 | { | |
150 | struct ipset *c; | |
151 | struct iprange r; | |
1caa23ff | 152 | int32_t ia,ib; |
794f2398 SE |
153 | |
154 | c=ipset_new(); | |
155 | ia=0; ib=0; | |
156 | while (ia<a->l || ib<b->l) { | |
157 | if (ia<a->l) | |
158 | if (ib<b->l) | |
159 | if (a->d[ia].a < b->d[ib].a) | |
160 | r=a->d[ia++]; | |
161 | else | |
162 | r=b->d[ib++]; | |
163 | else | |
164 | r=a->d[ia++]; | |
165 | else | |
166 | r=b->d[ib++]; | |
167 | ||
168 | if (c->l==0) | |
169 | ipset_append_range(c,r); | |
170 | else if (r.a <= c->d[c->l-1].b+1) | |
171 | /* Extends (or is consumed by) the last range */ | |
c9c047dc | 172 | c->d[c->l-1].b=MAX(c->d[c->l-1].b, r.b); |
794f2398 SE |
173 | else |
174 | ipset_append_range(c,r); | |
175 | } | |
176 | return c; | |
177 | } | |
178 | ||
179 | struct ipset *ipset_intersection(struct ipset *a, struct ipset *b) | |
180 | { | |
181 | struct ipset *r; | |
182 | struct iprange ra, rb; | |
1caa23ff | 183 | int32_t ia,ib; |
794f2398 SE |
184 | |
185 | r=ipset_new(); | |
186 | ia=0; ib=0; | |
187 | ||
188 | while (ia<a->l && ib<b->l) { | |
189 | ra=a->d[ia]; | |
190 | rb=b->d[ib]; | |
191 | if (ra.b < rb.a) | |
192 | /* The first entry of a doesn't overlap with any part of b */ | |
193 | ia++; | |
194 | else if (ra.a > rb.b) | |
195 | /* The first entry of b doesn't overlap with any part of a */ | |
196 | ib++; | |
197 | else { | |
198 | /* Trim away any leading edges */ | |
199 | if (ra.a < rb.a) | |
200 | /* a starts before b */ | |
201 | ra.a=rb.a; | |
202 | else if (ra.a > rb.a) | |
203 | /* b starts before a */ | |
204 | rb.a=ra.a; | |
205 | ||
206 | /* Now the ranges start at the same point */ | |
207 | if (ra.b == rb.b) { | |
208 | /* The ranges are equal */ | |
209 | ipset_append_range(r,ra); | |
210 | ia++; | |
211 | ib++; | |
212 | } else if (ra.b < rb.b) { | |
213 | /* a is the smaller range */ | |
214 | ipset_append_range(r,ra); | |
215 | ia++; | |
216 | } else { | |
217 | /* y is the smaller range */ | |
218 | ipset_append_range(r,rb); | |
219 | ib++; | |
220 | } | |
221 | } | |
222 | } | |
223 | return r; | |
224 | } | |
225 | ||
226 | struct ipset *ipset_complement(struct ipset *a) | |
227 | { | |
228 | struct ipset *r; | |
229 | struct iprange n; | |
230 | int64_t pre; | |
1caa23ff IJ |
231 | int32_t i; |
232 | uint32_t lo,hi; | |
794f2398 SE |
233 | |
234 | r=ipset_new(); | |
235 | pre=-1; | |
236 | for (i=0; i<a->l; i++) { | |
237 | lo=a->d[i].a; | |
238 | hi=a->d[i].b; | |
239 | if (lo!=0) { | |
240 | n.a=pre+1; | |
241 | n.b=lo-1; | |
242 | ipset_append_range(r,n); | |
243 | } | |
244 | pre=hi; | |
245 | } | |
246 | if (pre!=0xffffffff) { | |
247 | n.a=pre+1; | |
248 | n.b=0xffffffff; | |
249 | ipset_append_range(r,n); | |
250 | } | |
251 | return r; | |
252 | } | |
253 | ||
254 | /* Return a-b */ | |
255 | struct ipset *ipset_subtract(struct ipset *a, struct ipset *b) | |
256 | { | |
257 | struct ipset *c, *r; | |
258 | c=ipset_complement(b); | |
259 | r=ipset_intersection(a,c); | |
260 | ipset_free(c); | |
261 | return r; | |
262 | } | |
263 | ||
264 | bool_t ipset_is_empty(struct ipset *a) | |
265 | { | |
266 | return (a->l==0); | |
267 | } | |
268 | ||
269 | bool_t ipset_contains_addr(struct ipset *a, uint32_t addr) | |
7138d0c5 | 270 | { |
1caa23ff | 271 | int32_t i; |
794f2398 SE |
272 | struct iprange r; |
273 | ||
274 | for (i=0; i<a->l; i++) { | |
275 | r=a->d[i]; | |
276 | if (addr>=r.a && addr<=r.b) return True; | |
277 | if (addr<r.a) return False; | |
7138d0c5 SE |
278 | } |
279 | return False; | |
280 | } | |
281 | ||
794f2398 SE |
282 | /* sub is a subset of super if it does not intersect with the complement |
283 | of super */ | |
284 | bool_t ipset_is_subset(struct ipset *super, struct ipset *sub) | |
285 | { | |
286 | struct ipset *superc; | |
287 | struct ipset *inter; | |
288 | bool_t empty; | |
289 | ||
290 | superc=ipset_complement(super); | |
291 | inter=ipset_intersection(superc,sub); | |
292 | empty=ipset_is_empty(inter); | |
293 | ipset_free(inter); | |
294 | ipset_free(superc); | |
295 | return empty; | |
296 | } | |
297 | ||
298 | struct subnet_list *ipset_to_subnet_list(struct ipset *is) | |
299 | { | |
300 | struct subnet_list *r; | |
ff05a229 | 301 | int64_t a,b,lobit,himask,lomask; |
1caa23ff IJ |
302 | int bits; |
303 | int32_t i; | |
794f2398 SE |
304 | |
305 | r=subnet_list_new(); | |
306 | for (i=0; i<is->l; i++) { | |
307 | a=is->d[i].a; | |
308 | b=is->d[i].b; | |
309 | ||
310 | lomask=1; | |
311 | lobit=1; | |
312 | himask=0xfffffffe; | |
313 | bits=32; | |
314 | while (a<=b) { | |
315 | if ((a & lomask) != 0) { | |
316 | subnet_list_append(r,a,bits); | |
317 | a=a+lobit; | |
318 | } else if ((b & lomask) != lomask) { | |
319 | subnet_list_append(r,b&himask,bits); | |
320 | b=b-lobit; | |
321 | } else { | |
322 | lomask = (lomask << 1) | 1; | |
323 | lobit = (lobit << 1); | |
324 | himask = himask ^ lobit; | |
325 | bits = bits - 1; | |
326 | ASSERT(bits>=0); | |
327 | } | |
328 | } | |
329 | } | |
330 | /* Sort the list? */ | |
331 | return r; | |
332 | } | |
333 | ||
5540bab7 IJ |
334 | #define IPADDR_BUFLEN 20 |
335 | ||
336 | static char *ipaddr_getbuf(void) | |
337 | { | |
5e7a63be | 338 | SBUF_DEFINE(16, IPADDR_BUFLEN); |
5f37eb10 | 339 | return SBUF; |
5540bab7 IJ |
340 | } |
341 | ||
7138d0c5 SE |
342 | /* The string buffer must be at least 16 bytes long */ |
343 | string_t ipaddr_to_string(uint32_t addr) | |
344 | { | |
345 | uint8_t a,b,c,d; | |
346 | string_t s; | |
347 | ||
5540bab7 | 348 | s=ipaddr_getbuf(); |
7138d0c5 SE |
349 | a=addr>>24; |
350 | b=addr>>16; | |
351 | c=addr>>8; | |
352 | d=addr; | |
353 | snprintf(s, 16, "%d.%d.%d.%d", a, b, c, d); | |
354 | return s; | |
355 | } | |
356 | ||
794f2398 | 357 | string_t subnet_to_string(struct subnet sn) |
7138d0c5 | 358 | { |
794f2398 | 359 | uint32_t addr=sn.prefix; |
7138d0c5 SE |
360 | uint8_t a,b,c,d; |
361 | string_t s; | |
7138d0c5 | 362 | |
322a0105 | 363 | s=ipaddr_getbuf(); |
7138d0c5 SE |
364 | a=addr>>24; |
365 | b=addr>>16; | |
366 | c=addr>>8; | |
367 | d=addr; | |
794f2398 SE |
368 | snprintf(s, 19, "%d.%d.%d.%d/%d", a, b, c, d, sn.len); |
369 | return s; | |
370 | } | |
371 | ||
fe5e9cc4 | 372 | static struct subnet string_item_to_subnet(item_t *i, cstring_t desc, |
794f2398 SE |
373 | bool_t *invert) |
374 | { | |
375 | struct subnet s; | |
376 | uint32_t a, b, c, d, n; | |
1caa23ff | 377 | int match; |
fe5e9cc4 | 378 | cstring_t in; |
794f2398 SE |
379 | |
380 | *invert=False; | |
381 | ||
382 | /* i is not guaranteed to be a string */ | |
383 | if (i->type!=t_string) { | |
384 | cfgfatal(i->loc,desc,"expecting a string (subnet specification)\n"); | |
385 | } | |
386 | in=i->data.string; | |
387 | ||
388 | if (strcmp(in,"default")==0) { | |
389 | s.prefix=0; | |
390 | s.mask=0; | |
391 | s.len=0; | |
392 | return s; | |
393 | } | |
394 | ||
395 | if (*in=='!') { | |
396 | *invert=True; | |
397 | in++; | |
398 | } | |
399 | /* We expect strings of the form "a.b.c.d[/n]", i.e. the dots are | |
400 | NOT optional. The subnet mask is optional; if missing it is assumed | |
401 | to be /32. */ | |
402 | match=sscanf(in,"%u.%u.%u.%u/%u", &a, &b, &c, &d, &n); | |
403 | if (match<4) { | |
404 | cfgfatal(i->loc,desc,"\"%s\" is not a valid " | |
405 | "subnet specification\n",in); | |
406 | } | |
407 | if (match<5) { | |
408 | n=32; | |
7138d0c5 | 409 | } |
794f2398 SE |
410 | if (a>255 || b>255 || c>255 || d>255 || n>32) { |
411 | cfgfatal(i->loc,desc,"\"%s\": range error\n",in); | |
412 | } | |
413 | s.prefix=(a<<24)|(b<<16)|(c<<8)|(d); | |
414 | s.mask=n?(~0UL << (32-n)):0; | |
415 | s.len=n; | |
416 | if (s.prefix & ~s.mask) { | |
417 | cfgfatal(i->loc,desc,"\"%s\": prefix not fully contained " | |
418 | "in mask\n",in); | |
7138d0c5 | 419 | } |
7138d0c5 SE |
420 | return s; |
421 | } | |
794f2398 | 422 | |
a094a1ba | 423 | uint32_t string_item_to_ipaddr(const item_t *i, cstring_t desc) |
794f2398 SE |
424 | { |
425 | uint32_t a, b, c, d; | |
1caa23ff | 426 | int match; |
794f2398 SE |
427 | |
428 | /* i is not guaranteed to be a string */ | |
429 | if (i->type!=t_string) { | |
430 | cfgfatal(i->loc,desc,"expecting a string (IP address)\n"); | |
431 | } | |
432 | ||
433 | match=sscanf(i->data.string,"%u.%u.%u.%u", &a, &b, &c, &d); | |
434 | if (match<4) { | |
435 | cfgfatal(i->loc,desc,"\"%s\" is not a valid " | |
436 | "IP address\n",i->data.string); | |
437 | } | |
438 | if (a>255 || b>255 || c>255 || d>255) { | |
439 | cfgfatal(i->loc,desc,"\"%s\": range error\n",i->data.string); | |
440 | } | |
441 | return (a<<24)|(b<<16)|(c<<8)|(d); | |
442 | } | |
443 | ||
444 | struct ipset *string_list_to_ipset(list_t *l, struct cloc loc, | |
fe5e9cc4 | 445 | cstring_t module, cstring_t param) |
794f2398 SE |
446 | { |
447 | struct ipset *r, *n, *isn; | |
448 | uint32_t e,i; | |
449 | item_t *item; | |
450 | bool_t inv; | |
451 | ||
452 | r=ipset_new(); | |
453 | e=list_length(l); | |
454 | for (i=0; i<e; i++) { | |
455 | item=list_elem(l,i); | |
456 | isn=ipset_from_subnet(string_item_to_subnet(item,param,&inv)); | |
457 | if (inv) { | |
458 | n=ipset_subtract(r,isn); | |
459 | } else { | |
460 | n=ipset_union(r,isn); | |
461 | } | |
462 | ipset_free(r); | |
463 | ipset_free(isn); | |
464 | r=n; | |
465 | } | |
466 | return r; | |
467 | } |