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