1 7b19e0f1 2017-11-05 stsp /*
  2 7b19e0f1 2017-11-05 stsp  * Copyright (c) 2017 Stefan Sperling <stsp@openbsd.org>
  3 7b19e0f1 2017-11-05 stsp  *
  4 7b19e0f1 2017-11-05 stsp  * Permission to use, copy, modify, and distribute this software for any
  5 7b19e0f1 2017-11-05 stsp  * purpose with or without fee is hereby granted, provided that the above
  6 7b19e0f1 2017-11-05 stsp  * copyright notice and this permission notice appear in all copies.
  7 7b19e0f1 2017-11-05 stsp  *
  8 7b19e0f1 2017-11-05 stsp  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9 7b19e0f1 2017-11-05 stsp  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10 7b19e0f1 2017-11-05 stsp  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11 7b19e0f1 2017-11-05 stsp  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12 7b19e0f1 2017-11-05 stsp  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13 7b19e0f1 2017-11-05 stsp  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14 7b19e0f1 2017-11-05 stsp  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15 7b19e0f1 2017-11-05 stsp  */
 16 7b19e0f1 2017-11-05 stsp 
 17 4027f31a 2017-11-04 stsp #include <sys/types.h>
 18 4027f31a 2017-11-04 stsp #include <sha1.h>
 19 4027f31a 2017-11-04 stsp #include <stdio.h>
 20 4027f31a 2017-11-04 stsp #include <stdlib.h>
 21 4027f31a 2017-11-04 stsp #include <string.h>
 22 4027f31a 2017-11-04 stsp #include <util.h>
 23 11995603 2017-11-05 stsp #include <limits.h>
 24 11995603 2017-11-05 stsp #include <errno.h>
 25 4027f31a 2017-11-04 stsp 
 26 4027f31a 2017-11-04 stsp #include "got_error.h"
 27 11995603 2017-11-05 stsp #include "got_object.h"
 28 11995603 2017-11-05 stsp #include "got_repository.h"
 29 4027f31a 2017-11-04 stsp #include "got_refs.h"
 30 4027f31a 2017-11-04 stsp 
 31 c3f94f68 2017-11-05 stsp #include "path.h"
 32 c3f94f68 2017-11-05 stsp 
 33 11995603 2017-11-05 stsp 
 34 4027f31a 2017-11-04 stsp static const struct got_error *
 35 4027f31a 2017-11-04 stsp parse_symref(struct got_reference **ref, const char *name, const char *line)
 36 4027f31a 2017-11-04 stsp {
 37 4027f31a 2017-11-04 stsp 	struct got_symref *symref;
 38 4027f31a 2017-11-04 stsp 	char *symref_name;
 39 4027f31a 2017-11-04 stsp 	char *symref_ref;
 40 4027f31a 2017-11-04 stsp 
 41 4027f31a 2017-11-04 stsp 	if (line[0] == '\0')
 42 4027f31a 2017-11-04 stsp 		return got_error(GOT_ERR_NOT_REF);
 43 4027f31a 2017-11-04 stsp 
 44 4027f31a 2017-11-04 stsp 	symref_name = strdup(name);
 45 4027f31a 2017-11-04 stsp 	if (symref_name == NULL)
 46 4027f31a 2017-11-04 stsp 		return got_error(GOT_ERR_NO_MEM);
 47 4027f31a 2017-11-04 stsp 	symref_ref = strdup(line);
 48 4027f31a 2017-11-04 stsp 	if (symref_ref == NULL) {
 49 4027f31a 2017-11-04 stsp 		free(symref_name);
 50 4027f31a 2017-11-04 stsp 		return got_error(GOT_ERR_NO_MEM);
 51 4027f31a 2017-11-04 stsp 	}
 52 4027f31a 2017-11-04 stsp 
 53 4027f31a 2017-11-04 stsp 	*ref = calloc(1, sizeof(**ref));
 54 4027f31a 2017-11-04 stsp 	(*ref)->flags |= GOT_REF_IS_SYMBOLIC;
 55 4027f31a 2017-11-04 stsp 	symref = &((*ref)->ref.symref);
 56 4027f31a 2017-11-04 stsp 	symref->name = symref_name;
 57 4027f31a 2017-11-04 stsp 	symref->ref = symref_ref;
 58 4027f31a 2017-11-04 stsp 	return NULL;
 59 4027f31a 2017-11-04 stsp }
 60 4027f31a 2017-11-04 stsp 
 61 4027f31a 2017-11-04 stsp static int
 62 11995603 2017-11-05 stsp parse_xdigit(uint8_t *val, const char *hex)
 63 11995603 2017-11-05 stsp {
 64 11995603 2017-11-05 stsp 	char *ep;
 65 11995603 2017-11-05 stsp 	long lval;
 66 11995603 2017-11-05 stsp 
 67 11995603 2017-11-05 stsp 	errno = 0;
 68 11995603 2017-11-05 stsp 	lval = strtol(hex, &ep, 16);
 69 11995603 2017-11-05 stsp 	if (hex[0] == '\0' || *ep != '\0')
 70 11995603 2017-11-05 stsp 		return 0;
 71 11995603 2017-11-05 stsp 	if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
 72 11995603 2017-11-05 stsp 		return 0;
 73 11995603 2017-11-05 stsp 
 74 11995603 2017-11-05 stsp 	*val = (uint8_t)lval;
 75 11995603 2017-11-05 stsp 	return 1;
 76 11995603 2017-11-05 stsp }
 77 11995603 2017-11-05 stsp 
 78 11995603 2017-11-05 stsp static int
 79 4027f31a 2017-11-04 stsp parse_sha1_digest(uint8_t *digest, const char *line)
 80 4027f31a 2017-11-04 stsp {
 81 11995603 2017-11-05 stsp 	uint8_t b = 0;
 82 11995603 2017-11-05 stsp 	char hex[3] = {'\0', '\0', '\0'};
 83 11995603 2017-11-05 stsp 	int i, j;
 84 4027f31a 2017-11-04 stsp 
 85 4027f31a 2017-11-04 stsp 	for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
 86 11995603 2017-11-05 stsp 		if (line[0] == '\0' || line[1] == '\0')
 87 4027f31a 2017-11-04 stsp 			return 0;
 88 11995603 2017-11-05 stsp 		for (j = 0; j < 2; j++) {
 89 11995603 2017-11-05 stsp 			hex[j] = *line;
 90 11995603 2017-11-05 stsp 			line++;
 91 11995603 2017-11-05 stsp 		}
 92 11995603 2017-11-05 stsp 		if (!parse_xdigit(&b, hex))
 93 11995603 2017-11-05 stsp 			return 0;
 94 11995603 2017-11-05 stsp 		digest[i] = b;
 95 4027f31a 2017-11-04 stsp 	}
 96 4027f31a 2017-11-04 stsp 
 97 4027f31a 2017-11-04 stsp 	return 1;
 98 4027f31a 2017-11-04 stsp }
 99 4027f31a 2017-11-04 stsp 
100 4027f31a 2017-11-04 stsp static const struct got_error *
101 4027f31a 2017-11-04 stsp parse_ref_line(struct got_reference **ref, const char *name, const char *line)
102 4027f31a 2017-11-04 stsp {
103 4027f31a 2017-11-04 stsp 	uint8_t digest[SHA1_DIGEST_LENGTH];
104 4027f31a 2017-11-04 stsp 	char *ref_name;
105 4027f31a 2017-11-04 stsp 
106 4027f31a 2017-11-04 stsp 	if (strncmp(line, "ref: ", 5) == 0) {
107 4027f31a 2017-11-04 stsp 		line += 5;
108 4027f31a 2017-11-04 stsp 		return parse_symref(ref, name, line);
109 4027f31a 2017-11-04 stsp 	}
110 4027f31a 2017-11-04 stsp 
111 4027f31a 2017-11-04 stsp 	ref_name = strdup(name);
112 4027f31a 2017-11-04 stsp 	if (ref_name == NULL)
113 4027f31a 2017-11-04 stsp 		return got_error(GOT_ERR_NO_MEM);
114 4027f31a 2017-11-04 stsp 
115 4027f31a 2017-11-04 stsp 	if (!parse_sha1_digest(digest, line))
116 4027f31a 2017-11-04 stsp 		return got_error(GOT_ERR_NOT_REF);
117 4027f31a 2017-11-04 stsp 
118 4027f31a 2017-11-04 stsp 	*ref = calloc(1, sizeof(**ref));
119 4027f31a 2017-11-04 stsp 	(*ref)->ref.ref.name = ref_name;
120 4027f31a 2017-11-04 stsp 	memcpy(&(*ref)->ref.ref.sha1, digest, SHA1_DIGEST_LENGTH);
121 4027f31a 2017-11-04 stsp 	return NULL;
122 4027f31a 2017-11-04 stsp }
123 4027f31a 2017-11-04 stsp 
124 4027f31a 2017-11-04 stsp static const struct got_error *
125 4027f31a 2017-11-04 stsp parse_ref_file(struct got_reference **ref, const char *name,
126 4027f31a 2017-11-04 stsp     const char *abspath)
127 4027f31a 2017-11-04 stsp {
128 4027f31a 2017-11-04 stsp 	const struct got_error *err = NULL;
129 4027f31a 2017-11-04 stsp 	FILE *f = fopen(abspath, "rb");
130 4027f31a 2017-11-04 stsp 	char *line;
131 4027f31a 2017-11-04 stsp 	size_t len;
132 4027f31a 2017-11-04 stsp 	const char delim[3] = {'\0', '\0', '\0'};
133 4027f31a 2017-11-04 stsp 
134 4027f31a 2017-11-04 stsp 	if (f == NULL)
135 4027f31a 2017-11-04 stsp 		return got_error(GOT_ERR_NOT_REF);
136 4027f31a 2017-11-04 stsp 
137 4027f31a 2017-11-04 stsp 	line = fparseln(f, &len, NULL, delim, 0);
138 4027f31a 2017-11-04 stsp 	if (line == NULL) {
139 4027f31a 2017-11-04 stsp 		err = got_error(GOT_ERR_NOT_REF);
140 4027f31a 2017-11-04 stsp 		goto done;
141 4027f31a 2017-11-04 stsp 	}
142 4027f31a 2017-11-04 stsp 
143 4027f31a 2017-11-04 stsp 	err = parse_ref_line(ref, name, line);
144 4027f31a 2017-11-04 stsp done:
145 4027f31a 2017-11-04 stsp 	free(line);
146 4027f31a 2017-11-04 stsp 	fclose(f);
147 4027f31a 2017-11-04 stsp 	return err;
148 4027f31a 2017-11-04 stsp }
149 4027f31a 2017-11-04 stsp 
150 11995603 2017-11-05 stsp static char *
151 11995603 2017-11-05 stsp get_refs_dir_path(struct got_repository *repo, const char *refname)
152 11995603 2017-11-05 stsp {
153 11995603 2017-11-05 stsp 	/* Some refs live in the .git directory. */
154 11995603 2017-11-05 stsp 	if (strcmp(refname, GOT_REF_HEAD) == 0 ||
155 11995603 2017-11-05 stsp 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
156 11995603 2017-11-05 stsp 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
157 11995603 2017-11-05 stsp 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0)
158 11995603 2017-11-05 stsp 		return got_repo_get_path_git_dir(repo);
159 11995603 2017-11-05 stsp 
160 11995603 2017-11-05 stsp 	/* Is the ref name relative to the .git directory? */
161 11995603 2017-11-05 stsp 	if (strncmp(refname, "refs/", 5) == 0)
162 11995603 2017-11-05 stsp 		return got_repo_get_path_git_dir(repo);
163 11995603 2017-11-05 stsp 
164 11995603 2017-11-05 stsp 	return got_repo_get_path_refs(repo);
165 11995603 2017-11-05 stsp }
166 11995603 2017-11-05 stsp 
167 4027f31a 2017-11-04 stsp const struct got_error *
168 11995603 2017-11-05 stsp got_ref_open(struct got_reference **ref, struct got_repository *repo,
169 4027f31a 2017-11-04 stsp    const char *refname)
170 4027f31a 2017-11-04 stsp {
171 4027f31a 2017-11-04 stsp 	const struct got_error *err = NULL;
172 4027f31a 2017-11-04 stsp 	char *path_ref = NULL;
173 4027f31a 2017-11-04 stsp 	char *normpath = NULL;
174 4027f31a 2017-11-04 stsp 	const char *parent_dir;
175 11995603 2017-11-05 stsp 	char *path_refs = get_refs_dir_path(repo, refname);
176 11995603 2017-11-05 stsp 
177 11995603 2017-11-05 stsp 	if (path_refs == NULL) {
178 11995603 2017-11-05 stsp 		err = got_error(GOT_ERR_NO_MEM);
179 11995603 2017-11-05 stsp 		goto done;
180 11995603 2017-11-05 stsp 	}
181 4027f31a 2017-11-04 stsp 	
182 4027f31a 2017-11-04 stsp 	/* XXX For now, this assumes that refs exist in the filesystem. */
183 4027f31a 2017-11-04 stsp 
184 4027f31a 2017-11-04 stsp 	if (asprintf(&path_ref, "%s/%s", path_refs, refname) == -1) {
185 4027f31a 2017-11-04 stsp 		err = got_error(GOT_ERR_NO_MEM);
186 4027f31a 2017-11-04 stsp 		goto done;
187 4027f31a 2017-11-04 stsp 	}
188 4027f31a 2017-11-04 stsp 
189 4027f31a 2017-11-04 stsp 	normpath = got_path_normalize(path_ref);
190 4027f31a 2017-11-04 stsp 	if (normpath == NULL) {
191 4027f31a 2017-11-04 stsp 		err = got_error(GOT_ERR_NOT_REF);
192 4027f31a 2017-11-04 stsp 		goto done;
193 4027f31a 2017-11-04 stsp 	}
194 4027f31a 2017-11-04 stsp 
195 11995603 2017-11-05 stsp 	err = parse_ref_file(ref, refname, normpath);
196 4027f31a 2017-11-04 stsp done:
197 4027f31a 2017-11-04 stsp 	free(normpath);
198 4027f31a 2017-11-04 stsp 	free(path_ref);
199 11995603 2017-11-05 stsp 	free(path_refs);
200 4027f31a 2017-11-04 stsp 	return err;
201 4027f31a 2017-11-04 stsp }
202 4027f31a 2017-11-04 stsp 
203 4027f31a 2017-11-04 stsp void
204 4027f31a 2017-11-04 stsp got_ref_close(struct got_reference *ref)
205 4027f31a 2017-11-04 stsp {
206 4027f31a 2017-11-04 stsp 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
207 4027f31a 2017-11-04 stsp 		free(ref->ref.symref.name);
208 4027f31a 2017-11-04 stsp 	else
209 4027f31a 2017-11-04 stsp 		free(ref->ref.ref.name);
210 4027f31a 2017-11-04 stsp 	free(ref);
211 4027f31a 2017-11-04 stsp }
212 11995603 2017-11-05 stsp 
213 11995603 2017-11-05 stsp struct got_reference *
214 11995603 2017-11-05 stsp got_ref_dup(struct got_reference *ref)
215 11995603 2017-11-05 stsp {
216 11995603 2017-11-05 stsp 	struct got_reference *ret = calloc(1, sizeof(*ret));
217 11995603 2017-11-05 stsp 	char *name = NULL;
218 11995603 2017-11-05 stsp 	char *symref = NULL;
219 11995603 2017-11-05 stsp 
220 11995603 2017-11-05 stsp 	if (ret == NULL)
221 11995603 2017-11-05 stsp 		return NULL;
222 11995603 2017-11-05 stsp 
223 11995603 2017-11-05 stsp 	ret->flags = ref->flags;
224 11995603 2017-11-05 stsp 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
225 11995603 2017-11-05 stsp 		ret->ref.symref.name = strdup(ref->ref.symref.name);
226 11995603 2017-11-05 stsp 		if (ret->ref.symref.name == NULL) {
227 11995603 2017-11-05 stsp 			free(ret);
228 11995603 2017-11-05 stsp 			return NULL;
229 11995603 2017-11-05 stsp 		}
230 11995603 2017-11-05 stsp 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
231 11995603 2017-11-05 stsp 		if (ret->ref.symref.ref == NULL) {
232 11995603 2017-11-05 stsp 			free(ret->ref.symref.name);
233 11995603 2017-11-05 stsp 			free(ret);
234 11995603 2017-11-05 stsp 			return NULL;
235 11995603 2017-11-05 stsp 		}
236 11995603 2017-11-05 stsp 	} else {
237 11995603 2017-11-05 stsp 		ref->ref.ref.name = strdup(ref->ref.ref.name);
238 11995603 2017-11-05 stsp 		if (ref->ref.ref.name == NULL) {
239 11995603 2017-11-05 stsp 			free(ret);
240 11995603 2017-11-05 stsp 			return NULL;
241 11995603 2017-11-05 stsp 		}
242 11995603 2017-11-05 stsp 		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
243 11995603 2017-11-05 stsp 		    SHA1_DIGEST_LENGTH);
244 11995603 2017-11-05 stsp 	}
245 11995603 2017-11-05 stsp 
246 11995603 2017-11-05 stsp 	return ret;
247 11995603 2017-11-05 stsp }
248 11995603 2017-11-05 stsp 
249 11995603 2017-11-05 stsp static const struct got_error *
250 11995603 2017-11-05 stsp resolve_symbolic_ref(struct got_reference **resolved,
251 11995603 2017-11-05 stsp     struct got_repository *repo, struct got_reference *ref)
252 11995603 2017-11-05 stsp {
253 11995603 2017-11-05 stsp 	struct got_reference *nextref;
254 11995603 2017-11-05 stsp 	const struct got_error *err;
255 11995603 2017-11-05 stsp 
256 11995603 2017-11-05 stsp 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref);
257 11995603 2017-11-05 stsp 	if (err)
258 11995603 2017-11-05 stsp 		return err;
259 11995603 2017-11-05 stsp 
260 11995603 2017-11-05 stsp 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
261 11995603 2017-11-05 stsp 		err = resolve_symbolic_ref(resolved, repo, nextref);
262 11995603 2017-11-05 stsp 	else
263 11995603 2017-11-05 stsp 		*resolved = got_ref_dup(nextref);
264 11995603 2017-11-05 stsp 
265 11995603 2017-11-05 stsp 	got_ref_close(nextref);
266 11995603 2017-11-05 stsp 	return err;
267 11995603 2017-11-05 stsp }
268 11995603 2017-11-05 stsp 
269 11995603 2017-11-05 stsp const struct got_error *
270 11995603 2017-11-05 stsp got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
271 11995603 2017-11-05 stsp     struct got_reference *ref)
272 11995603 2017-11-05 stsp {
273 11995603 2017-11-05 stsp 	const struct got_error *err;
274 11995603 2017-11-05 stsp 
275 11995603 2017-11-05 stsp 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
276 11995603 2017-11-05 stsp 		struct got_reference *resolved = NULL;
277 11995603 2017-11-05 stsp 		err = resolve_symbolic_ref(&resolved, repo, ref);
278 11995603 2017-11-05 stsp 		if (err == NULL)
279 11995603 2017-11-05 stsp 			err = got_ref_resolve(id, repo, resolved);
280 11995603 2017-11-05 stsp 		free(resolved);
281 11995603 2017-11-05 stsp 		return err;
282 11995603 2017-11-05 stsp 	}
283 11995603 2017-11-05 stsp 
284 11995603 2017-11-05 stsp 	*id = calloc(1, sizeof(**id));
285 11995603 2017-11-05 stsp 	if (*id == NULL)
286 11995603 2017-11-05 stsp 		return got_error(GOT_ERR_NO_MEM);
287 11995603 2017-11-05 stsp 	memcpy((*id)->sha1, ref->ref.ref.sha1, SHA1_DIGEST_LENGTH);
288 11995603 2017-11-05 stsp 	return NULL;
289 11995603 2017-11-05 stsp }