1 /* $OpenBSD: rcsnum.c,v 1.59 2017/08/28 19:33:20 otto Exp $ */
2 /*
3 * Copyright (c) 2004 Jean-Francois Brousseau <jfb@openbsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. The name of the author may not be used to endorse or promote products
13 * derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <ctype.h>
28 #include <stdlib.h>
29 #include <string.h>
30
31 #include "cvs.h"
32
33 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
34
35 static void rcsnum_setsize(RCSNUM *, u_int);
36 static char *rcsnum_itoa(u_int16_t, char *, size_t);
37
38 /*
39 * rcsnum_alloc()
40 *
41 * Allocate an RCS number structure and return a pointer to it.
42 */
43 RCSNUM *
rcsnum_alloc(void)44 rcsnum_alloc(void)
45 {
46 RCSNUM *rnp;
47
48 rnp = xcalloc(1, sizeof(*rnp));
49 rnp->rn_len = 0;
50
51 return (rnp);
52 }
53
54 /*
55 * rcsnum_addmagic()
56 *
57 * Adds a magic branch number to an RCS number.
58 * Returns 0 on success, or -1 on failure.
59 */
60 int
rcsnum_addmagic(RCSNUM * rn)61 rcsnum_addmagic(RCSNUM *rn)
62 {
63 if (!rn->rn_len || rn->rn_len > RCSNUM_MAXLEN - 1)
64 return -1;
65 rcsnum_setsize(rn, rn->rn_len + 1);
66 rn->rn_id[rn->rn_len - 1] = rn->rn_id[rn->rn_len - 2];
67 rn->rn_id[rn->rn_len - 2] = 0;
68
69 return 0;
70 }
71
72 /*
73 * rcsnum_parse()
74 *
75 * Parse a string specifying an RCS number and return the corresponding RCSNUM.
76 */
77 RCSNUM *
rcsnum_parse(const char * str)78 rcsnum_parse(const char *str)
79 {
80 const char *ep;
81 RCSNUM *num;
82
83 num = rcsnum_alloc();
84 if (rcsnum_aton(str, &ep, num) < 0 || *ep != '\0') {
85 free(num);
86 num = NULL;
87 }
88
89 return (num);
90 }
91
92 /*
93 * rcsnum_tostr()
94 *
95 * Format the RCS number <nump> into a human-readable dot-separated
96 * representation and store the resulting string in <buf>, which is of size
97 * <blen>.
98 * Returns a pointer to the start of <buf>. On failure <buf> is set to
99 * an empty string.
100 */
101 char *
rcsnum_tostr(const RCSNUM * nump,char * buf,size_t blen)102 rcsnum_tostr(const RCSNUM *nump, char *buf, size_t blen)
103 {
104 u_int i;
105 char tmp[8];
106
107 if (nump == NULL || nump->rn_len == 0) {
108 buf[0] = '\0';
109 return (buf);
110 }
111
112 if (strlcpy(buf, rcsnum_itoa(nump->rn_id[0], buf, blen), blen) >= blen)
113 fatal("rcsnum_tostr: truncation");
114 for (i = 1; i < nump->rn_len; i++) {
115 const char *str;
116
117 str = rcsnum_itoa(nump->rn_id[i], tmp, sizeof(tmp));
118 if (strlcat(buf, ".", blen) >= blen ||
119 strlcat(buf, str, blen) >= blen)
120 fatal("rcsnum_tostr: truncation");
121 }
122 return (buf);
123 }
124
125 static char *
rcsnum_itoa(u_int16_t num,char * buf,size_t len)126 rcsnum_itoa(u_int16_t num, char *buf, size_t len)
127 {
128 u_int16_t i;
129 char *p;
130
131 if (num == 0)
132 return "0";
133
134 p = buf + len - 1;
135 i = num;
136 bzero(buf, len);
137 while (i) {
138 *--p = '0' + (i % 10);
139 i /= 10;
140 }
141 return (p);
142 }
143
144 /*
145 * rcsnum_cpy()
146 *
147 * Copy the number stored in <nsrc> in the destination <ndst> up to <depth>
148 * numbers deep. If <depth> is 0, there is no depth limit.
149 */
150 void
rcsnum_cpy(const RCSNUM * nsrc,RCSNUM * ndst,u_int depth)151 rcsnum_cpy(const RCSNUM *nsrc, RCSNUM *ndst, u_int depth)
152 {
153 u_int len;
154
155 len = nsrc->rn_len;
156 if (depth != 0 && len > depth)
157 len = depth;
158
159 rcsnum_setsize(ndst, len);
160 memcpy(ndst->rn_id, nsrc->rn_id, len * sizeof(*(nsrc->rn_id)));
161 }
162
163 /*
164 * rcsnum_cmp()
165 *
166 * Compare the two numbers <n1> and <n2>. Returns -1 if <n1> is larger than
167 * <n2>, 0 if they are both the same, and 1 if <n2> is larger than <n1>.
168 * The <depth> argument specifies how many numbers deep should be checked for
169 * the result. A value of 0 means that the depth will be the maximum of the
170 * two numbers, so that a longer number is considered greater than a shorter
171 * number if they are equal up to the minimum length.
172 */
173 int
rcsnum_cmp(RCSNUM * n1,RCSNUM * n2,u_int depth)174 rcsnum_cmp(RCSNUM *n1, RCSNUM *n2, u_int depth)
175 {
176 int res;
177 u_int i;
178 size_t slen;
179
180 if (!rcsnum_differ(n1, n2))
181 return (0);
182
183 slen = MINIMUM(n1->rn_len, n2->rn_len);
184 if (depth != 0 && slen > depth)
185 slen = depth;
186
187 for (i = 0; i < slen; i++) {
188 res = n1->rn_id[i] - n2->rn_id[i];
189 if (res < 0)
190 return (1);
191 else if (res > 0)
192 return (-1);
193 }
194
195 /* If an explicit depth was specified, and we've
196 * already checked up to depth, consider the
197 * revision numbers equal. */
198 if (depth != 0 && slen == depth)
199 return (0);
200 else if (n1->rn_len > n2->rn_len)
201 return (-1);
202 else if (n2->rn_len > n1->rn_len)
203 return (1);
204
205 return (0);
206 }
207
208 /*
209 * rcsnum_aton()
210 *
211 * Translate the string <str> containing a sequence of digits and periods into
212 * its binary representation, which is stored in <nump>. The address of the
213 * first byte not part of the number is stored in <ep> on return, if it is not
214 * NULL.
215 * Returns 0 on success, or -1 on failure.
216 */
217 int
rcsnum_aton(const char * str,const char ** ep,RCSNUM * nump)218 rcsnum_aton(const char *str, const char **ep, RCSNUM *nump)
219 {
220 u_int32_t val;
221 const char *sp;
222 char *s;
223
224 nump->rn_len = 0;
225 nump->rn_id[0] = 0;
226
227 for (sp = str;; sp++) {
228 if (!isdigit((unsigned char)*sp) && (*sp != '.'))
229 break;
230
231 if (*sp == '.') {
232 if (nump->rn_len >= RCSNUM_MAXLEN - 1)
233 goto rcsnum_aton_failed;
234
235 nump->rn_len++;
236 nump->rn_id[nump->rn_len] = 0;
237 continue;
238 }
239
240 val = (nump->rn_id[nump->rn_len] * 10) + (*sp - '0');
241 if (val > RCSNUM_MAXNUM)
242 fatal("RCSNUM overflow!");
243
244 nump->rn_id[nump->rn_len] = val;
245 }
246
247 if (ep != NULL)
248 *ep = sp;
249
250 /*
251 * Handle "magic" RCS branch numbers.
252 *
253 * What are they?
254 *
255 * Magic branch numbers have an extra .0. at the second farmost
256 * rightside of the branch number, so instead of having an odd
257 * number of dot-separated decimals, it will have an even number.
258 *
259 * Now, according to all the documentation I've found on the net
260 * about this, cvs does this for "efficiency reasons", I'd like
261 * to hear one.
262 *
263 * We just make sure we remove the .0. from in the branch number.
264 *
265 * XXX - for compatibility reasons with GNU cvs we _need_
266 * to skip this part for the 'log' command, apparently it does
267 * show the magic branches for an unknown and probably
268 * completely insane and not understandable reason in that output.
269 *
270 */
271 if (nump->rn_len > 2 && nump->rn_id[nump->rn_len - 1] == 0) {
272 /*
273 * Look for ".0.x" at the end of the branch number.
274 */
275 if ((s = strrchr(str, '.')) != NULL) {
276 s--;
277 while (*s != '.')
278 s--;
279
280 /*
281 * If we have a "magic" branch, adjust it
282 * so the .0. is removed.
283 */
284 if (!strncmp(s, RCS_MAGIC_BRANCH,
285 sizeof(RCS_MAGIC_BRANCH) - 1)) {
286 nump->rn_id[nump->rn_len - 1] =
287 nump->rn_id[nump->rn_len];
288 nump->rn_len--;
289 }
290 }
291 }
292
293 /* We can't have a single-digit rcs number. */
294 if (nump->rn_len == 0) {
295 nump->rn_len++;
296 nump->rn_id[nump->rn_len] = 0;
297 }
298
299 nump->rn_len++;
300 return (nump->rn_len);
301
302 rcsnum_aton_failed:
303 nump->rn_len = 0;
304 return (-1);
305 }
306
307 /*
308 * rcsnum_inc()
309 *
310 * Increment the revision number specified in <num>.
311 * Returns a pointer to the <num> on success, or NULL on failure.
312 */
313 RCSNUM *
rcsnum_inc(RCSNUM * num)314 rcsnum_inc(RCSNUM *num)
315 {
316 if (num->rn_id[num->rn_len - 1] == RCSNUM_MAXNUM)
317 return (NULL);
318 num->rn_id[num->rn_len - 1]++;
319 return (num);
320 }
321
322 /*
323 * rcsnum_dec()
324 *
325 * Decreases the revision number specified in <num>, if doing so will not
326 * result in an ending value below 1. E.g. 4.2 will go to 4.1 but 4.1 will
327 * be returned as 4.1.
328 */
329 RCSNUM *
rcsnum_dec(RCSNUM * num)330 rcsnum_dec(RCSNUM *num)
331 {
332 /* XXX - Is it an error for the number to be 0? */
333 if (num->rn_id[num->rn_len - 1] <= 1)
334 return (num);
335 num->rn_id[num->rn_len - 1]--;
336 return (num);
337 }
338
339 /*
340 * rcsnum_revtobr()
341 *
342 * Retrieve the branch number associated with the revision number <num>.
343 * If <num> is a branch revision, the returned value will be the same
344 * number as the argument.
345 */
346 RCSNUM *
rcsnum_revtobr(const RCSNUM * num)347 rcsnum_revtobr(const RCSNUM *num)
348 {
349 RCSNUM *brnum;
350
351 if (num->rn_len < 2)
352 return (NULL);
353
354 brnum = rcsnum_alloc();
355 rcsnum_cpy(num, brnum, 0);
356
357 if (!RCSNUM_ISBRANCH(brnum))
358 brnum->rn_len--;
359
360 return (brnum);
361 }
362
363 /*
364 * rcsnum_brtorev()
365 *
366 * Retrieve the initial revision number associated with the branch number <num>.
367 * If <num> is a revision number, an error will be returned.
368 */
369 RCSNUM *
rcsnum_brtorev(const RCSNUM * brnum)370 rcsnum_brtorev(const RCSNUM *brnum)
371 {
372 RCSNUM *num;
373
374 if (!RCSNUM_ISBRANCH(brnum)) {
375 return (NULL);
376 }
377
378 num = rcsnum_alloc();
379 rcsnum_setsize(num, brnum->rn_len + 1);
380 rcsnum_cpy(brnum, num, brnum->rn_len);
381 num->rn_id[num->rn_len++] = 1;
382
383 return (num);
384 }
385
386 RCSNUM *
rcsnum_new_branch(RCSNUM * rev)387 rcsnum_new_branch(RCSNUM *rev)
388 {
389 RCSNUM *branch;
390
391 if (rev->rn_len > RCSNUM_MAXLEN - 1)
392 return NULL;
393
394 branch = rcsnum_alloc();
395 rcsnum_cpy(rev, branch, 0);
396 rcsnum_setsize(branch, rev->rn_len + 1);
397 branch->rn_id[branch->rn_len - 1] = 2;
398
399 return branch;
400 }
401
402 RCSNUM *
rcsnum_branch_root(RCSNUM * brev)403 rcsnum_branch_root(RCSNUM *brev)
404 {
405 RCSNUM *root;
406
407 if (!RCSNUM_ISBRANCHREV(brev))
408 fatal("rcsnum_branch_root: no revision on branch specified");
409
410 root = rcsnum_alloc();
411 rcsnum_cpy(brev, root, 0);
412 root->rn_len -= 2;
413 return (root);
414 }
415
416 static void
rcsnum_setsize(RCSNUM * num,u_int len)417 rcsnum_setsize(RCSNUM *num, u_int len)
418 {
419 num->rn_len = len;
420 }
421
422 int
rcsnum_differ(RCSNUM * r1,RCSNUM * r2)423 rcsnum_differ(RCSNUM *r1, RCSNUM *r2)
424 {
425 int i, len;
426
427 if (r1->rn_len != r2->rn_len)
428 return (1);
429
430 len = MINIMUM(r1->rn_len, r2->rn_len);
431 for (i = 0; i < len; i++) {
432 if (r1->rn_id[i] != r2->rn_id[i])
433 return (1);
434 }
435
436 return (0);
437 }
438