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. */ | |
3 | ||
7138d0c5 | 4 | #include "secnet.h" |
59230b9b IJ |
5 | #include <limits.h> |
6 | #include <assert.h> | |
7138d0c5 | 7 | #include <stdio.h> |
3b83c932 | 8 | #include <string.h> |
794f2398 | 9 | #include "ipaddr.h" |
c9c047dc | 10 | #include "util.h" |
794f2398 SE |
11 | |
12 | #define DEFAULT_ALLOC 2 | |
13 | #define EXTEND_ALLOC_BY 4 | |
14 | ||
15 | struct subnet_list *subnet_list_new(void) | |
16 | { | |
17 | struct subnet_list *r; | |
18 | r=safe_malloc(sizeof(*r),"subnet_list_new:list"); | |
19 | r->entries=0; | |
20 | r->alloc=DEFAULT_ALLOC; | |
bb9d0561 | 21 | r->list=safe_malloc_ary(sizeof(*r->list),r->alloc,"subnet_list_new:data"); |
794f2398 SE |
22 | return r; |
23 | } | |
24 | ||
25 | void subnet_list_free(struct subnet_list *a) | |
26 | { | |
27 | if (a->list) free(a->list); | |
28 | free(a); | |
29 | } | |
30 | ||
1caa23ff | 31 | static void subnet_list_set_len(struct subnet_list *a, int32_t l) |
794f2398 SE |
32 | { |
33 | struct subnet *nd; | |
1caa23ff | 34 | int32_t na; |
794f2398 SE |
35 | |
36 | if (l>a->alloc) { | |
59230b9b | 37 | assert(a->alloc < (int)(INT_MAX/sizeof(*nd))-EXTEND_ALLOC_BY); |
794f2398 | 38 | na=a->alloc+EXTEND_ALLOC_BY; |
c921f0c5 | 39 | nd=safe_realloc_ary(a->list,sizeof(*nd),na,"subnet_list_set_len"); |
794f2398 SE |
40 | a->alloc=na; |
41 | a->list=nd; | |
42 | } | |
43 | a->entries=l; | |
44 | } | |
45 | ||
1caa23ff | 46 | void subnet_list_append(struct subnet_list *a, uint32_t prefix, int len) |
794f2398 SE |
47 | { |
48 | struct subnet *sn; | |
59230b9b | 49 | assert(a->entries < INT_MAX); |
794f2398 SE |
50 | subnet_list_set_len(a,a->entries+1); |
51 | sn=&a->list[a->entries-1]; | |
52 | sn->prefix=prefix; | |
53 | sn->len=len; | |
54 | sn->mask=len?(0xffffffff << (32-len)):0; | |
55 | } | |
7138d0c5 | 56 | |
794f2398 SE |
57 | struct ipset *ipset_new(void) |
58 | { | |
59 | struct ipset *r; | |
60 | r=safe_malloc(sizeof(*r),"ipset_new:set"); | |
61 | r->l=0; | |
62 | r->a=DEFAULT_ALLOC; | |
63 | r->d=safe_malloc(sizeof(*r->d)*r->a,"ipset_new:data"); | |
64 | return r; | |
65 | } | |
7138d0c5 | 66 | |
794f2398 | 67 | void ipset_free(struct ipset *a) |
7138d0c5 | 68 | { |
794f2398 SE |
69 | if (a->d) free(a->d); |
70 | free(a); | |
7138d0c5 SE |
71 | } |
72 | ||
794f2398 SE |
73 | #ifdef DEBUG |
74 | static void ipset_dump(struct ipset *a, string_t name) | |
7138d0c5 | 75 | { |
1caa23ff | 76 | int32_t i; |
794f2398 SE |
77 | |
78 | printf("%s: ",name); | |
79 | for (i=0; i<a->l; i++) { | |
80 | printf("[%08x-%08x] ",a->d[i].a,a->d[i].b); | |
7138d0c5 | 81 | } |
794f2398 | 82 | printf("\n"); |
7138d0c5 | 83 | } |
794f2398 | 84 | #endif |
7138d0c5 | 85 | |
794f2398 | 86 | struct ipset *ipset_from_subnet(struct subnet s) |
7138d0c5 | 87 | { |
794f2398 SE |
88 | struct ipset *r; |
89 | ||
90 | r=ipset_new(); | |
91 | r->l=1; | |
92 | r->d[0].a=s.prefix; | |
93 | r->d[0].b=s.prefix | (~s.mask); | |
94 | return r; | |
7138d0c5 SE |
95 | } |
96 | ||
794f2398 | 97 | struct ipset *ipset_from_subnet_list(struct subnet_list *l) |
7138d0c5 | 98 | { |
794f2398 | 99 | struct ipset *r, *a, *b; |
1caa23ff | 100 | int32_t i; |
7138d0c5 | 101 | |
794f2398 SE |
102 | r=ipset_new(); |
103 | for (i=0; i<l->entries; i++) { | |
104 | a=ipset_from_subnet(l->list[i]); | |
105 | b=ipset_union(r,a); | |
106 | ipset_free(a); | |
107 | ipset_free(r); | |
108 | r=b; | |
7138d0c5 | 109 | } |
794f2398 | 110 | return r; |
7138d0c5 SE |
111 | } |
112 | ||
1caa23ff | 113 | static void ipset_set_len(struct ipset *a, int32_t l) |
794f2398 SE |
114 | { |
115 | struct iprange *nd; | |
1caa23ff | 116 | int32_t na; |
794f2398 SE |
117 | |
118 | if (l>a->a) { | |
59230b9b | 119 | assert(a->a < INT_MAX-EXTEND_ALLOC_BY); |
794f2398 | 120 | na=a->a+EXTEND_ALLOC_BY; |
c921f0c5 | 121 | nd=safe_realloc_ary(a->d,sizeof(*nd),na,"ipset_set_len"); |
794f2398 SE |
122 | a->a=na; |
123 | a->d=nd; | |
124 | } | |
125 | a->l=l; | |
126 | } | |
127 | ||
128 | static void ipset_append_range(struct ipset *a, struct iprange r) | |
129 | { | |
130 | ipset_set_len(a,a->l+1); | |
131 | a->d[a->l-1]=r; | |
132 | } | |
133 | ||
794f2398 SE |
134 | struct ipset *ipset_union(struct ipset *a, struct ipset *b) |
135 | { | |
136 | struct ipset *c; | |
137 | struct iprange r; | |
1caa23ff | 138 | int32_t ia,ib; |
794f2398 SE |
139 | |
140 | c=ipset_new(); | |
141 | ia=0; ib=0; | |
142 | while (ia<a->l || ib<b->l) { | |
143 | if (ia<a->l) | |
144 | if (ib<b->l) | |
145 | if (a->d[ia].a < b->d[ib].a) | |
146 | r=a->d[ia++]; | |
147 | else | |
148 | r=b->d[ib++]; | |
149 | else | |
150 | r=a->d[ia++]; | |
151 | else | |
152 | r=b->d[ib++]; | |
153 | ||
154 | if (c->l==0) | |
155 | ipset_append_range(c,r); | |
156 | else if (r.a <= c->d[c->l-1].b+1) | |
157 | /* Extends (or is consumed by) the last range */ | |
c9c047dc | 158 | c->d[c->l-1].b=MAX(c->d[c->l-1].b, r.b); |
794f2398 SE |
159 | else |
160 | ipset_append_range(c,r); | |
161 | } | |
162 | return c; | |
163 | } | |
164 | ||
165 | struct ipset *ipset_intersection(struct ipset *a, struct ipset *b) | |
166 | { | |
167 | struct ipset *r; | |
168 | struct iprange ra, rb; | |
1caa23ff | 169 | int32_t ia,ib; |
794f2398 SE |
170 | |
171 | r=ipset_new(); | |
172 | ia=0; ib=0; | |
173 | ||
174 | while (ia<a->l && ib<b->l) { | |
175 | ra=a->d[ia]; | |
176 | rb=b->d[ib]; | |
177 | if (ra.b < rb.a) | |
178 | /* The first entry of a doesn't overlap with any part of b */ | |
179 | ia++; | |
180 | else if (ra.a > rb.b) | |
181 | /* The first entry of b doesn't overlap with any part of a */ | |
182 | ib++; | |
183 | else { | |
184 | /* Trim away any leading edges */ | |
185 | if (ra.a < rb.a) | |
186 | /* a starts before b */ | |
187 | ra.a=rb.a; | |
188 | else if (ra.a > rb.a) | |
189 | /* b starts before a */ | |
190 | rb.a=ra.a; | |
191 | ||
192 | /* Now the ranges start at the same point */ | |
193 | if (ra.b == rb.b) { | |
194 | /* The ranges are equal */ | |
195 | ipset_append_range(r,ra); | |
196 | ia++; | |
197 | ib++; | |
198 | } else if (ra.b < rb.b) { | |
199 | /* a is the smaller range */ | |
200 | ipset_append_range(r,ra); | |
201 | ia++; | |
202 | } else { | |
203 | /* y is the smaller range */ | |
204 | ipset_append_range(r,rb); | |
205 | ib++; | |
206 | } | |
207 | } | |
208 | } | |
209 | return r; | |
210 | } | |
211 | ||
212 | struct ipset *ipset_complement(struct ipset *a) | |
213 | { | |
214 | struct ipset *r; | |
215 | struct iprange n; | |
216 | int64_t pre; | |
1caa23ff IJ |
217 | int32_t i; |
218 | uint32_t lo,hi; | |
794f2398 SE |
219 | |
220 | r=ipset_new(); | |
221 | pre=-1; | |
222 | for (i=0; i<a->l; i++) { | |
223 | lo=a->d[i].a; | |
224 | hi=a->d[i].b; | |
225 | if (lo!=0) { | |
226 | n.a=pre+1; | |
227 | n.b=lo-1; | |
228 | ipset_append_range(r,n); | |
229 | } | |
230 | pre=hi; | |
231 | } | |
232 | if (pre!=0xffffffff) { | |
233 | n.a=pre+1; | |
234 | n.b=0xffffffff; | |
235 | ipset_append_range(r,n); | |
236 | } | |
237 | return r; | |
238 | } | |
239 | ||
240 | /* Return a-b */ | |
241 | struct ipset *ipset_subtract(struct ipset *a, struct ipset *b) | |
242 | { | |
243 | struct ipset *c, *r; | |
244 | c=ipset_complement(b); | |
245 | r=ipset_intersection(a,c); | |
246 | ipset_free(c); | |
247 | return r; | |
248 | } | |
249 | ||
250 | bool_t ipset_is_empty(struct ipset *a) | |
251 | { | |
252 | return (a->l==0); | |
253 | } | |
254 | ||
255 | bool_t ipset_contains_addr(struct ipset *a, uint32_t addr) | |
7138d0c5 | 256 | { |
1caa23ff | 257 | int32_t i; |
794f2398 SE |
258 | struct iprange r; |
259 | ||
260 | for (i=0; i<a->l; i++) { | |
261 | r=a->d[i]; | |
262 | if (addr>=r.a && addr<=r.b) return True; | |
263 | if (addr<r.a) return False; | |
7138d0c5 SE |
264 | } |
265 | return False; | |
266 | } | |
267 | ||
794f2398 SE |
268 | /* sub is a subset of super if it does not intersect with the complement |
269 | of super */ | |
270 | bool_t ipset_is_subset(struct ipset *super, struct ipset *sub) | |
271 | { | |
272 | struct ipset *superc; | |
273 | struct ipset *inter; | |
274 | bool_t empty; | |
275 | ||
276 | superc=ipset_complement(super); | |
277 | inter=ipset_intersection(superc,sub); | |
278 | empty=ipset_is_empty(inter); | |
279 | ipset_free(inter); | |
280 | ipset_free(superc); | |
281 | return empty; | |
282 | } | |
283 | ||
284 | struct subnet_list *ipset_to_subnet_list(struct ipset *is) | |
285 | { | |
286 | struct subnet_list *r; | |
ff05a229 | 287 | int64_t a,b,lobit,himask,lomask; |
1caa23ff IJ |
288 | int bits; |
289 | int32_t i; | |
794f2398 SE |
290 | |
291 | r=subnet_list_new(); | |
292 | for (i=0; i<is->l; i++) { | |
293 | a=is->d[i].a; | |
294 | b=is->d[i].b; | |
295 | ||
296 | lomask=1; | |
297 | lobit=1; | |
298 | himask=0xfffffffe; | |
299 | bits=32; | |
300 | while (a<=b) { | |
301 | if ((a & lomask) != 0) { | |
302 | subnet_list_append(r,a,bits); | |
303 | a=a+lobit; | |
304 | } else if ((b & lomask) != lomask) { | |
305 | subnet_list_append(r,b&himask,bits); | |
306 | b=b-lobit; | |
307 | } else { | |
308 | lomask = (lomask << 1) | 1; | |
309 | lobit = (lobit << 1); | |
310 | himask = himask ^ lobit; | |
311 | bits = bits - 1; | |
312 | ASSERT(bits>=0); | |
313 | } | |
314 | } | |
315 | } | |
316 | /* Sort the list? */ | |
317 | return r; | |
318 | } | |
319 | ||
5540bab7 IJ |
320 | #define IPADDR_NBUFS_SHIFT 4 |
321 | #define IPADDR_NBUFS (1 << IPADDR_NBUFS_SHIFT) | |
322 | #define IPADDR_BUFLEN 20 | |
323 | ||
324 | static char *ipaddr_getbuf(void) | |
325 | { | |
326 | static int ipaddr_bufnum; | |
327 | static char ipaddr_bufs[IPADDR_NBUFS][IPADDR_BUFLEN]; | |
328 | ||
329 | ipaddr_bufnum++; | |
330 | ipaddr_bufnum &= IPADDR_NBUFS-1; | |
331 | return ipaddr_bufs[ipaddr_bufnum]; | |
332 | } | |
333 | ||
7138d0c5 SE |
334 | /* The string buffer must be at least 16 bytes long */ |
335 | string_t ipaddr_to_string(uint32_t addr) | |
336 | { | |
337 | uint8_t a,b,c,d; | |
338 | string_t s; | |
339 | ||
5540bab7 | 340 | s=ipaddr_getbuf(); |
7138d0c5 SE |
341 | a=addr>>24; |
342 | b=addr>>16; | |
343 | c=addr>>8; | |
344 | d=addr; | |
345 | snprintf(s, 16, "%d.%d.%d.%d", a, b, c, d); | |
346 | return s; | |
347 | } | |
348 | ||
794f2398 | 349 | string_t subnet_to_string(struct subnet sn) |
7138d0c5 | 350 | { |
794f2398 | 351 | uint32_t addr=sn.prefix; |
7138d0c5 SE |
352 | uint8_t a,b,c,d; |
353 | string_t s; | |
7138d0c5 | 354 | |
322a0105 | 355 | s=ipaddr_getbuf(); |
7138d0c5 SE |
356 | a=addr>>24; |
357 | b=addr>>16; | |
358 | c=addr>>8; | |
359 | d=addr; | |
794f2398 SE |
360 | snprintf(s, 19, "%d.%d.%d.%d/%d", a, b, c, d, sn.len); |
361 | return s; | |
362 | } | |
363 | ||
fe5e9cc4 | 364 | static struct subnet string_item_to_subnet(item_t *i, cstring_t desc, |
794f2398 SE |
365 | bool_t *invert) |
366 | { | |
367 | struct subnet s; | |
368 | uint32_t a, b, c, d, n; | |
1caa23ff | 369 | int match; |
fe5e9cc4 | 370 | cstring_t in; |
794f2398 SE |
371 | |
372 | *invert=False; | |
373 | ||
374 | /* i is not guaranteed to be a string */ | |
375 | if (i->type!=t_string) { | |
376 | cfgfatal(i->loc,desc,"expecting a string (subnet specification)\n"); | |
377 | } | |
378 | in=i->data.string; | |
379 | ||
380 | if (strcmp(in,"default")==0) { | |
381 | s.prefix=0; | |
382 | s.mask=0; | |
383 | s.len=0; | |
384 | return s; | |
385 | } | |
386 | ||
387 | if (*in=='!') { | |
388 | *invert=True; | |
389 | in++; | |
390 | } | |
391 | /* We expect strings of the form "a.b.c.d[/n]", i.e. the dots are | |
392 | NOT optional. The subnet mask is optional; if missing it is assumed | |
393 | to be /32. */ | |
394 | match=sscanf(in,"%u.%u.%u.%u/%u", &a, &b, &c, &d, &n); | |
395 | if (match<4) { | |
396 | cfgfatal(i->loc,desc,"\"%s\" is not a valid " | |
397 | "subnet specification\n",in); | |
398 | } | |
399 | if (match<5) { | |
400 | n=32; | |
7138d0c5 | 401 | } |
794f2398 SE |
402 | if (a>255 || b>255 || c>255 || d>255 || n>32) { |
403 | cfgfatal(i->loc,desc,"\"%s\": range error\n",in); | |
404 | } | |
405 | s.prefix=(a<<24)|(b<<16)|(c<<8)|(d); | |
406 | s.mask=n?(~0UL << (32-n)):0; | |
407 | s.len=n; | |
408 | if (s.prefix & ~s.mask) { | |
409 | cfgfatal(i->loc,desc,"\"%s\": prefix not fully contained " | |
410 | "in mask\n",in); | |
7138d0c5 | 411 | } |
7138d0c5 SE |
412 | return s; |
413 | } | |
794f2398 | 414 | |
a094a1ba | 415 | uint32_t string_item_to_ipaddr(const item_t *i, cstring_t desc) |
794f2398 SE |
416 | { |
417 | uint32_t a, b, c, d; | |
1caa23ff | 418 | int match; |
794f2398 SE |
419 | |
420 | /* i is not guaranteed to be a string */ | |
421 | if (i->type!=t_string) { | |
422 | cfgfatal(i->loc,desc,"expecting a string (IP address)\n"); | |
423 | } | |
424 | ||
425 | match=sscanf(i->data.string,"%u.%u.%u.%u", &a, &b, &c, &d); | |
426 | if (match<4) { | |
427 | cfgfatal(i->loc,desc,"\"%s\" is not a valid " | |
428 | "IP address\n",i->data.string); | |
429 | } | |
430 | if (a>255 || b>255 || c>255 || d>255) { | |
431 | cfgfatal(i->loc,desc,"\"%s\": range error\n",i->data.string); | |
432 | } | |
433 | return (a<<24)|(b<<16)|(c<<8)|(d); | |
434 | } | |
435 | ||
436 | struct ipset *string_list_to_ipset(list_t *l, struct cloc loc, | |
fe5e9cc4 | 437 | cstring_t module, cstring_t param) |
794f2398 SE |
438 | { |
439 | struct ipset *r, *n, *isn; | |
440 | uint32_t e,i; | |
441 | item_t *item; | |
442 | bool_t inv; | |
443 | ||
444 | r=ipset_new(); | |
445 | e=list_length(l); | |
446 | for (i=0; i<e; i++) { | |
447 | item=list_elem(l,i); | |
448 | isn=ipset_from_subnet(string_item_to_subnet(item,param,&inv)); | |
449 | if (inv) { | |
450 | n=ipset_subtract(r,isn); | |
451 | } else { | |
452 | n=ipset_union(r,isn); | |
453 | } | |
454 | ipset_free(r); | |
455 | ipset_free(isn); | |
456 | r=n; | |
457 | } | |
458 | return r; | |
459 | } |