1 d71d75ad 2017-11-05 stsp /*
  2 d71d75ad 2017-11-05 stsp  * Copyright (c) 2017 Stefan Sperling <stsp@openbsd.org>
  3 d71d75ad 2017-11-05 stsp  *
  4 d71d75ad 2017-11-05 stsp  * Permission to use, copy, modify, and distribute this software for any
  5 d71d75ad 2017-11-05 stsp  * purpose with or without fee is hereby granted, provided that the above
  6 d71d75ad 2017-11-05 stsp  * copyright notice and this permission notice appear in all copies.
  7 d71d75ad 2017-11-05 stsp  *
  8 d71d75ad 2017-11-05 stsp  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9 d71d75ad 2017-11-05 stsp  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10 d71d75ad 2017-11-05 stsp  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11 d71d75ad 2017-11-05 stsp  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12 d71d75ad 2017-11-05 stsp  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13 d71d75ad 2017-11-05 stsp  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14 d71d75ad 2017-11-05 stsp  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15 d71d75ad 2017-11-05 stsp  */
 16 d71d75ad 2017-11-05 stsp 
 17 d71d75ad 2017-11-05 stsp #include <stdio.h>
 18 ab9a70b2 2017-11-06 stsp #include <stdlib.h>
 19 ab9a70b2 2017-11-06 stsp #include <string.h>
 20 d71d75ad 2017-11-05 stsp #include <sha1.h>
 21 ab9a70b2 2017-11-06 stsp #include <zlib.h>
 22 ab9a70b2 2017-11-06 stsp #include <ctype.h>
 23 ab9a70b2 2017-11-06 stsp #include <limits.h>
 24 d71d75ad 2017-11-05 stsp 
 25 ab9a70b2 2017-11-06 stsp #include "got_error.h"
 26 d71d75ad 2017-11-05 stsp #include "got_object.h"
 27 ab9a70b2 2017-11-06 stsp #include "got_repository.h"
 28 d71d75ad 2017-11-05 stsp 
 29 ab9a70b2 2017-11-06 stsp #ifndef MIN
 30 ab9a70b2 2017-11-06 stsp #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
 31 ab9a70b2 2017-11-06 stsp #endif
 32 ab9a70b2 2017-11-06 stsp 
 33 ab9a70b2 2017-11-06 stsp #ifndef nitems
 34 ab9a70b2 2017-11-06 stsp #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
 35 ab9a70b2 2017-11-06 stsp #endif
 36 ab9a70b2 2017-11-06 stsp 
 37 ab9a70b2 2017-11-06 stsp #define GOT_OBJ_TAG_COMMIT	"commit"
 38 ab9a70b2 2017-11-06 stsp #define GOT_OBJ_TAG_TREE	"tree"
 39 ab9a70b2 2017-11-06 stsp #define GOT_OBJ_TAG_BLOB	"blob"
 40 ab9a70b2 2017-11-06 stsp 
 41 d71d75ad 2017-11-05 stsp const char *
 42 d71d75ad 2017-11-05 stsp got_object_id_str(struct got_object_id *id, char *buf, size_t size)
 43 d71d75ad 2017-11-05 stsp {
 44 d71d75ad 2017-11-05 stsp 	char *p = buf;
 45 d71d75ad 2017-11-05 stsp 	char hex[3];
 46 d71d75ad 2017-11-05 stsp 	int i;
 47 d71d75ad 2017-11-05 stsp 
 48 d71d75ad 2017-11-05 stsp 	if (size < SHA1_DIGEST_STRING_LENGTH)
 49 d71d75ad 2017-11-05 stsp 		return NULL;
 50 d71d75ad 2017-11-05 stsp 
 51 d71d75ad 2017-11-05 stsp 	for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
 52 d71d75ad 2017-11-05 stsp 		snprintf(hex, sizeof(hex), "%.2x", id->sha1[i]);
 53 d71d75ad 2017-11-05 stsp 		p[0] = hex[0];
 54 d71d75ad 2017-11-05 stsp 		p[1] = hex[1];
 55 d71d75ad 2017-11-05 stsp 		p += 2;
 56 d71d75ad 2017-11-05 stsp 	}
 57 d71d75ad 2017-11-05 stsp 	p[0] = '\0';
 58 d71d75ad 2017-11-05 stsp 
 59 d71d75ad 2017-11-05 stsp 	return buf;
 60 d71d75ad 2017-11-05 stsp }
 61 ab9a70b2 2017-11-06 stsp 
 62 ab9a70b2 2017-11-06 stsp struct got_zstream_buf {
 63 ab9a70b2 2017-11-06 stsp 	z_stream z;
 64 ab9a70b2 2017-11-06 stsp 	char *inbuf;
 65 ab9a70b2 2017-11-06 stsp 	size_t inlen;
 66 ab9a70b2 2017-11-06 stsp 	char *outbuf;
 67 ab9a70b2 2017-11-06 stsp 	size_t outlen;
 68 ab9a70b2 2017-11-06 stsp 	int flags;
 69 ab9a70b2 2017-11-06 stsp #define GOT_ZSTREAM_F_HAVE_MORE 0x01
 70 ab9a70b2 2017-11-06 stsp };
 71 ab9a70b2 2017-11-06 stsp 
 72 ab9a70b2 2017-11-06 stsp static void
 73 ab9a70b2 2017-11-06 stsp inflate_end(struct got_zstream_buf *zb)
 74 ab9a70b2 2017-11-06 stsp {
 75 ab9a70b2 2017-11-06 stsp 	free(zb->inbuf);
 76 ab9a70b2 2017-11-06 stsp 	free(zb->outbuf);
 77 ab9a70b2 2017-11-06 stsp 	inflateEnd(&zb->z);
 78 ab9a70b2 2017-11-06 stsp }
 79 ab9a70b2 2017-11-06 stsp 
 80 ab9a70b2 2017-11-06 stsp static const struct got_error *
 81 ab9a70b2 2017-11-06 stsp inflate_init(struct got_zstream_buf *zb, size_t bufsize)
 82 ab9a70b2 2017-11-06 stsp {
 83 ab9a70b2 2017-11-06 stsp 	const struct got_error *err = NULL;
 84 ab9a70b2 2017-11-06 stsp 
 85 ab9a70b2 2017-11-06 stsp 	memset(zb, 0, sizeof(*zb));
 86 ab9a70b2 2017-11-06 stsp 
 87 ab9a70b2 2017-11-06 stsp 	zb->z.zalloc = Z_NULL;
 88 ab9a70b2 2017-11-06 stsp 	zb->z.zfree = Z_NULL;
 89 ab9a70b2 2017-11-06 stsp 	if (inflateInit(&zb->z) != Z_OK) {
 90 ab9a70b2 2017-11-06 stsp 		err = got_error(GOT_ERR_IO);
 91 ab9a70b2 2017-11-06 stsp 		goto done;
 92 ab9a70b2 2017-11-06 stsp 	}
 93 ab9a70b2 2017-11-06 stsp 
 94 ab9a70b2 2017-11-06 stsp 	zb->inlen = zb->outlen = bufsize;
 95 ab9a70b2 2017-11-06 stsp 
 96 ab9a70b2 2017-11-06 stsp 	zb->inbuf = calloc(1, zb->inlen);
 97 ab9a70b2 2017-11-06 stsp 	if (zb->inbuf == NULL) {
 98 ab9a70b2 2017-11-06 stsp 		err = got_error(GOT_ERR_NO_MEM);
 99 ab9a70b2 2017-11-06 stsp 		goto done;
100 ab9a70b2 2017-11-06 stsp 	}
101 ab9a70b2 2017-11-06 stsp 
102 ab9a70b2 2017-11-06 stsp 	zb->outbuf = calloc(1, zb->outlen);
103 ab9a70b2 2017-11-06 stsp 	if (zb->outbuf == NULL) {
104 ab9a70b2 2017-11-06 stsp 		err = got_error(GOT_ERR_NO_MEM);
105 ab9a70b2 2017-11-06 stsp 		goto done;
106 ab9a70b2 2017-11-06 stsp 	}
107 ab9a70b2 2017-11-06 stsp 
108 ab9a70b2 2017-11-06 stsp done:
109 ab9a70b2 2017-11-06 stsp 	if (err)
110 ab9a70b2 2017-11-06 stsp 		inflate_end(zb);
111 ab9a70b2 2017-11-06 stsp 	return err;
112 ab9a70b2 2017-11-06 stsp }
113 ab9a70b2 2017-11-06 stsp 
114 ab9a70b2 2017-11-06 stsp static const struct got_error *
115 ab9a70b2 2017-11-06 stsp inflate_read(struct got_zstream_buf *zb, FILE *f, size_t *outlenp)
116 ab9a70b2 2017-11-06 stsp {
117 ab9a70b2 2017-11-06 stsp 	size_t last_total_out = zb->z.total_out;
118 ab9a70b2 2017-11-06 stsp 	z_stream *z = &zb->z;
119 ab9a70b2 2017-11-06 stsp 	int n, ret;
120 ab9a70b2 2017-11-06 stsp 
121 ab9a70b2 2017-11-06 stsp 	z->next_out = zb->outbuf;
122 ab9a70b2 2017-11-06 stsp 	z->avail_out = zb->outlen;
123 ab9a70b2 2017-11-06 stsp 
124 ab9a70b2 2017-11-06 stsp 	if (z->avail_in == 0 && (zb->flags & GOT_ZSTREAM_F_HAVE_MORE) == 0) {
125 ab9a70b2 2017-11-06 stsp 		int i;
126 ab9a70b2 2017-11-06 stsp 		n = fread(zb->inbuf, 1, zb->inlen, f);
127 ab9a70b2 2017-11-06 stsp 		if (n == 0) {
128 ab9a70b2 2017-11-06 stsp 			if (ferror(f))
129 ab9a70b2 2017-11-06 stsp 				return got_error(GOT_ERR_IO);
130 ab9a70b2 2017-11-06 stsp 			*outlenp = 0;
131 ab9a70b2 2017-11-06 stsp 			return NULL;
132 ab9a70b2 2017-11-06 stsp 		}
133 ab9a70b2 2017-11-06 stsp 		z->next_in = zb->inbuf;
134 ab9a70b2 2017-11-06 stsp 		z->avail_in = n;
135 ab9a70b2 2017-11-06 stsp 	}
136 ab9a70b2 2017-11-06 stsp 
137 ab9a70b2 2017-11-06 stsp 	ret = inflate(z, Z_SYNC_FLUSH);
138 ab9a70b2 2017-11-06 stsp 	if (ret == Z_OK) {
139 ab9a70b2 2017-11-06 stsp 		if (z->avail_out == 0)
140 ab9a70b2 2017-11-06 stsp 			zb->flags |= GOT_ZSTREAM_F_HAVE_MORE;
141 ab9a70b2 2017-11-06 stsp 		else
142 ab9a70b2 2017-11-06 stsp 			zb->flags &= ~GOT_ZSTREAM_F_HAVE_MORE;
143 ab9a70b2 2017-11-06 stsp 	} else if (ret != Z_STREAM_END)
144 ab9a70b2 2017-11-06 stsp 		return got_error(GOT_ERR_DECOMPRESSION);
145 ab9a70b2 2017-11-06 stsp 
146 ab9a70b2 2017-11-06 stsp 	*outlenp = z->total_out - last_total_out;
147 ab9a70b2 2017-11-06 stsp 	return NULL;
148 ab9a70b2 2017-11-06 stsp }
149 ab9a70b2 2017-11-06 stsp 
150 ab9a70b2 2017-11-06 stsp static const struct got_error *
151 ab9a70b2 2017-11-06 stsp parse_obj_header(struct got_object **obj, char *buf, size_t len)
152 ab9a70b2 2017-11-06 stsp {
153 ab9a70b2 2017-11-06 stsp 	const char *obj_tags[] = {
154 ab9a70b2 2017-11-06 stsp 		GOT_OBJ_TAG_COMMIT,
155 ab9a70b2 2017-11-06 stsp 		GOT_OBJ_TAG_TREE,
156 ab9a70b2 2017-11-06 stsp 		GOT_OBJ_TAG_BLOB
157 ab9a70b2 2017-11-06 stsp 	};
158 ab9a70b2 2017-11-06 stsp 	const int obj_types[] = {
159 ab9a70b2 2017-11-06 stsp 		GOT_OBJ_TYPE_COMMIT,
160 ab9a70b2 2017-11-06 stsp 		GOT_OBJ_TYPE_TREE,
161 ab9a70b2 2017-11-06 stsp 		GOT_OBJ_TYPE_BLOB,
162 ab9a70b2 2017-11-06 stsp 	};
163 ab9a70b2 2017-11-06 stsp 	int type = 0;
164 ab9a70b2 2017-11-06 stsp 	size_t size = 0;
165 ab9a70b2 2017-11-06 stsp 	int i;
166 ab9a70b2 2017-11-06 stsp 	char *p = strchr(buf, '\0');
167 ab9a70b2 2017-11-06 stsp 
168 ab9a70b2 2017-11-06 stsp 	if (p == NULL)
169 ab9a70b2 2017-11-06 stsp 		return got_error(GOT_ERR_BAD_OBJ_HDR);
170 ab9a70b2 2017-11-06 stsp 
171 ab9a70b2 2017-11-06 stsp 	for (i = 0; i < nitems(obj_tags); i++) {
172 ab9a70b2 2017-11-06 stsp 		const char *tag = obj_tags[i];
173 ab9a70b2 2017-11-06 stsp 		const char *errstr;
174 ab9a70b2 2017-11-06 stsp 
175 ab9a70b2 2017-11-06 stsp 		if (strncmp(buf, tag, strlen(tag)) != 0)
176 ab9a70b2 2017-11-06 stsp 			continue;
177 ab9a70b2 2017-11-06 stsp 
178 ab9a70b2 2017-11-06 stsp 		type = obj_types[i];
179 ab9a70b2 2017-11-06 stsp 		if (len <= strlen(tag))
180 ab9a70b2 2017-11-06 stsp 			return got_error(GOT_ERR_BAD_OBJ_HDR);
181 ab9a70b2 2017-11-06 stsp 		size = strtonum(buf + strlen(tag), 0, LONG_MAX, &errstr);
182 ab9a70b2 2017-11-06 stsp 		if (errstr != NULL)
183 ab9a70b2 2017-11-06 stsp 			return got_error(GOT_ERR_BAD_OBJ_HDR);
184 ab9a70b2 2017-11-06 stsp 		break;
185 ab9a70b2 2017-11-06 stsp 	}
186 ab9a70b2 2017-11-06 stsp 
187 ab9a70b2 2017-11-06 stsp 	if (type == 0)
188 ab9a70b2 2017-11-06 stsp 		return got_error(GOT_ERR_BAD_OBJ_HDR);
189 ab9a70b2 2017-11-06 stsp 
190 ab9a70b2 2017-11-06 stsp 	*obj = calloc(1, sizeof(**obj));
191 ab9a70b2 2017-11-06 stsp 	(*obj)->type = type;
192 ab9a70b2 2017-11-06 stsp 	(*obj)->size = size;
193 ab9a70b2 2017-11-06 stsp 	return NULL;
194 ab9a70b2 2017-11-06 stsp }
195 ab9a70b2 2017-11-06 stsp 
196 ab9a70b2 2017-11-06 stsp static const struct got_error *
197 ab9a70b2 2017-11-06 stsp read_object_header(struct got_object **obj, struct got_repository *repo,
198 ab9a70b2 2017-11-06 stsp     const char *path)
199 ab9a70b2 2017-11-06 stsp {
200 ab9a70b2 2017-11-06 stsp 	const struct got_error *err;
201 ab9a70b2 2017-11-06 stsp 	FILE *f;
202 ab9a70b2 2017-11-06 stsp 	struct got_zstream_buf zb;
203 ab9a70b2 2017-11-06 stsp 	char *p;
204 ab9a70b2 2017-11-06 stsp 	size_t outlen;
205 ab9a70b2 2017-11-06 stsp 	int i, ret;
206 ab9a70b2 2017-11-06 stsp 
207 ab9a70b2 2017-11-06 stsp 	f = fopen(path, "rb");
208 ab9a70b2 2017-11-06 stsp 	if (f == NULL)
209 ab9a70b2 2017-11-06 stsp 		return got_error(GOT_ERR_BAD_PATH);
210 ab9a70b2 2017-11-06 stsp 
211 ab9a70b2 2017-11-06 stsp 	err = inflate_init(&zb, 64);
212 ab9a70b2 2017-11-06 stsp 	if (err) {
213 ab9a70b2 2017-11-06 stsp 		fclose(f);
214 ab9a70b2 2017-11-06 stsp 		return err;
215 ab9a70b2 2017-11-06 stsp 	}
216 ab9a70b2 2017-11-06 stsp 
217 ab9a70b2 2017-11-06 stsp 	err = inflate_read(&zb, f, &outlen);
218 ab9a70b2 2017-11-06 stsp 	if (err)
219 ab9a70b2 2017-11-06 stsp 		goto done;
220 ab9a70b2 2017-11-06 stsp 
221 ab9a70b2 2017-11-06 stsp 	err = parse_obj_header(obj, zb.outbuf, outlen);
222 ab9a70b2 2017-11-06 stsp done:
223 ab9a70b2 2017-11-06 stsp 	inflate_end(&zb);
224 ab9a70b2 2017-11-06 stsp 	fclose(f);
225 ab9a70b2 2017-11-06 stsp 	return err;
226 ab9a70b2 2017-11-06 stsp }
227 ab9a70b2 2017-11-06 stsp 
228 ab9a70b2 2017-11-06 stsp const struct got_error *
229 ab9a70b2 2017-11-06 stsp got_object_open(struct got_object **obj, struct got_repository *repo,
230 ab9a70b2 2017-11-06 stsp     struct got_object_id *id)
231 ab9a70b2 2017-11-06 stsp {
232 ab9a70b2 2017-11-06 stsp 	const struct got_error *err = NULL;
233 ab9a70b2 2017-11-06 stsp 	char *path_objects = got_repo_get_path_objects(repo);
234 ab9a70b2 2017-11-06 stsp 	char hex[SHA1_DIGEST_STRING_LENGTH];
235 ab9a70b2 2017-11-06 stsp 	char *path = NULL;
236 ab9a70b2 2017-11-06 stsp 
237 ab9a70b2 2017-11-06 stsp 	if (path_objects == NULL)
238 ab9a70b2 2017-11-06 stsp 		return got_error(GOT_ERR_NO_MEM);
239 ab9a70b2 2017-11-06 stsp 
240 ab9a70b2 2017-11-06 stsp 	got_object_id_str(id, hex, sizeof(hex));
241 ab9a70b2 2017-11-06 stsp 
242 ab9a70b2 2017-11-06 stsp 	if (asprintf(&path, "%s/%.2x/%s",
243 ab9a70b2 2017-11-06 stsp 	    path_objects, id->sha1[0], hex + 2) == -1) {
244 ab9a70b2 2017-11-06 stsp 		err = got_error(GOT_ERR_NO_MEM);
245 ab9a70b2 2017-11-06 stsp 		goto done;
246 ab9a70b2 2017-11-06 stsp 	}
247 ab9a70b2 2017-11-06 stsp 
248 ab9a70b2 2017-11-06 stsp 	err = read_object_header(obj, repo, path);
249 ab9a70b2 2017-11-06 stsp 	if (err == NULL)
250 ab9a70b2 2017-11-06 stsp 		memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
251 ab9a70b2 2017-11-06 stsp 
252 ab9a70b2 2017-11-06 stsp done:
253 ab9a70b2 2017-11-06 stsp 	free(path);
254 ab9a70b2 2017-11-06 stsp 	free(path_objects);
255 ab9a70b2 2017-11-06 stsp 	return err;
256 ab9a70b2 2017-11-06 stsp }
257 ab9a70b2 2017-11-06 stsp 
258 ab9a70b2 2017-11-06 stsp void
259 ab9a70b2 2017-11-06 stsp got_object_close(struct got_object *obj)
260 ab9a70b2 2017-11-06 stsp {
261 ab9a70b2 2017-11-06 stsp 	free(obj);
262 ab9a70b2 2017-11-06 stsp }