2 efd2a263 2018-01-19 stsp * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
4 efd2a263 2018-01-19 stsp * Permission to use, copy, modify, and distribute this software for any
5 efd2a263 2018-01-19 stsp * purpose with or without fee is hereby granted, provided that the above
6 efd2a263 2018-01-19 stsp * copyright notice and this permission notice appear in all copies.
8 efd2a263 2018-01-19 stsp * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 efd2a263 2018-01-19 stsp * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 efd2a263 2018-01-19 stsp * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 efd2a263 2018-01-19 stsp * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 efd2a263 2018-01-19 stsp * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 efd2a263 2018-01-19 stsp * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 efd2a263 2018-01-19 stsp * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 efd2a263 2018-01-19 stsp #include <sys/queue.h>
19 efd2a263 2018-01-19 stsp #include <stdio.h>
20 96f5e8b3 2018-01-23 stsp #include <stdlib.h>
21 96f5e8b3 2018-01-23 stsp #include <string.h>
22 efd2a263 2018-01-19 stsp #include <zlib.h>
23 efd2a263 2018-01-19 stsp #include <sha1.h>
25 efd2a263 2018-01-19 stsp #include "got_error.h"
26 efd2a263 2018-01-19 stsp #include "got_repository.h"
27 efd2a263 2018-01-19 stsp #include "got_object.h"
29 efd2a263 2018-01-19 stsp #include "delta.h"
30 3606d7fc 2018-02-11 stsp #include "path.h"
31 885d3e02 2018-01-27 stsp #include "zb.h"
34 885d3e02 2018-01-27 stsp #define MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
37 c3703302 2018-01-23 stsp struct got_delta *
38 0e22967e 2018-02-11 stsp got_delta_open(const char *path_packfile, off_t offset, size_t tslen,
39 0e22967e 2018-02-11 stsp int type, size_t size)
41 c3703302 2018-01-23 stsp struct got_delta *delta;
43 c3703302 2018-01-23 stsp delta = calloc(1, sizeof(*delta));
44 c3703302 2018-01-23 stsp if (delta == NULL)
45 96f5e8b3 2018-01-23 stsp return NULL;
47 c3703302 2018-01-23 stsp delta->path_packfile = strdup(path_packfile);
48 c3703302 2018-01-23 stsp if (delta->path_packfile == NULL) {
49 c3703302 2018-01-23 stsp free(delta);
50 96f5e8b3 2018-01-23 stsp return NULL;
52 c3703302 2018-01-23 stsp delta->type = type;
53 c3703302 2018-01-23 stsp delta->offset = offset;
54 0e22967e 2018-02-11 stsp delta->tslen = tslen;
55 c3703302 2018-01-23 stsp delta->size = size;
56 c3703302 2018-01-23 stsp return delta;
60 c3703302 2018-01-23 stsp got_delta_close(struct got_delta *delta)
62 c3703302 2018-01-23 stsp free(delta->path_packfile);
63 c3703302 2018-01-23 stsp free(delta);
67 efd2a263 2018-01-19 stsp const struct got_error *
68 96f5e8b3 2018-01-23 stsp got_delta_chain_get_base_type(int *type, struct got_delta_chain *deltas)
70 c3703302 2018-01-23 stsp struct got_delta *delta;
72 6691714a 2018-01-23 stsp /* The first delta in the chain should represent the base object. */
73 6691714a 2018-01-23 stsp delta = SIMPLEQ_FIRST(&deltas->entries);
74 6691714a 2018-01-23 stsp if (delta->type == GOT_OBJ_TYPE_COMMIT ||
75 6691714a 2018-01-23 stsp delta->type == GOT_OBJ_TYPE_TREE ||
76 6691714a 2018-01-23 stsp delta->type == GOT_OBJ_TYPE_BLOB ||
77 6691714a 2018-01-23 stsp delta->type == GOT_OBJ_TYPE_TAG) {
78 6691714a 2018-01-23 stsp *type = delta->type;
79 6691714a 2018-01-23 stsp return NULL;
82 96f5e8b3 2018-01-23 stsp return got_error(GOT_ERR_BAD_DELTA_CHAIN);
85 885d3e02 2018-01-27 stsp /* Fetch another (required) byte from the delta stream. */
86 885d3e02 2018-01-27 stsp static const struct got_error *
87 885d3e02 2018-01-27 stsp next_delta_byte(const uint8_t **p, size_t *remain)
89 885d3e02 2018-01-27 stsp if (--(*remain) == 0)
90 885d3e02 2018-01-27 stsp return got_error(GOT_ERR_BAD_DELTA);
92 885d3e02 2018-01-27 stsp return NULL;
95 885d3e02 2018-01-27 stsp static const struct got_error *
96 885d3e02 2018-01-27 stsp parse_size(uint64_t *size, const uint8_t **p, size_t *remain)
98 885d3e02 2018-01-27 stsp const struct got_error *err = NULL;
103 885d3e02 2018-01-27 stsp /* We do not support size values which don't fit in 64 bit. */
105 885d3e02 2018-01-27 stsp return got_error(GOT_ERR_NO_SPACE);
107 885d3e02 2018-01-27 stsp if (i == 0)
108 885d3e02 2018-01-27 stsp *size = ((**p) & GOT_DELTA_SIZE_VAL_MASK);
110 885d3e02 2018-01-27 stsp size_t shift = GOT_DELTA_SIZE_SHIFT * i;
111 885d3e02 2018-01-27 stsp *size |= (((**p) & GOT_DELTA_SIZE_VAL_MASK) << shift);
114 885d3e02 2018-01-27 stsp if (((**p) & GOT_DELTA_SIZE_MORE) == 0)
117 885d3e02 2018-01-27 stsp err = next_delta_byte(p, remain);
118 885d3e02 2018-01-27 stsp } while (err == NULL);
120 885d3e02 2018-01-27 stsp return err;
123 885d3e02 2018-01-27 stsp static const struct got_error *
124 885d3e02 2018-01-27 stsp parse_opcode(off_t *offset, size_t *len, const uint8_t **p, size_t *remain)
126 885d3e02 2018-01-27 stsp const struct got_error *err = NULL;
127 885d3e02 2018-01-27 stsp off_t o = 0;
128 885d3e02 2018-01-27 stsp size_t l = 0;
129 885d3e02 2018-01-27 stsp uint8_t opcode = **p;
131 885d3e02 2018-01-27 stsp if (opcode & GOT_DELTA_COPY_OFF1) {
132 885d3e02 2018-01-27 stsp err = next_delta_byte(p, remain);
134 885d3e02 2018-01-27 stsp return err;
135 885d3e02 2018-01-27 stsp o = (off_t)(**p);
137 885d3e02 2018-01-27 stsp if (opcode & GOT_DELTA_COPY_OFF2) {
138 885d3e02 2018-01-27 stsp err = next_delta_byte(p, remain);
140 885d3e02 2018-01-27 stsp return err;
141 885d3e02 2018-01-27 stsp o |= ((off_t)(**p)) << 8;
143 885d3e02 2018-01-27 stsp if (opcode & GOT_DELTA_COPY_OFF3) {
144 885d3e02 2018-01-27 stsp err = next_delta_byte(p, remain);
146 885d3e02 2018-01-27 stsp return err;
147 885d3e02 2018-01-27 stsp o |= ((off_t)(**p)) << 16;
149 885d3e02 2018-01-27 stsp if (opcode & GOT_DELTA_COPY_OFF4) {
150 885d3e02 2018-01-27 stsp err = next_delta_byte(p, remain);
152 885d3e02 2018-01-27 stsp return err;
153 885d3e02 2018-01-27 stsp o |= ((off_t)(**p)) << 24;
156 885d3e02 2018-01-27 stsp if (opcode & GOT_DELTA_COPY_LEN1) {
157 885d3e02 2018-01-27 stsp err = next_delta_byte(p, remain);
159 885d3e02 2018-01-27 stsp return err;
160 885d3e02 2018-01-27 stsp l = (off_t)(**p);
162 885d3e02 2018-01-27 stsp if (opcode & GOT_DELTA_COPY_LEN2) {
163 885d3e02 2018-01-27 stsp err = next_delta_byte(p, remain);
165 885d3e02 2018-01-27 stsp return err;
166 885d3e02 2018-01-27 stsp l |= ((off_t)(**p)) << 8;
168 885d3e02 2018-01-27 stsp if (opcode & GOT_DELTA_COPY_LEN3) {
169 885d3e02 2018-01-27 stsp err = next_delta_byte(p, remain);
171 885d3e02 2018-01-27 stsp return err;
172 885d3e02 2018-01-27 stsp l |= ((off_t)(**p)) << 16;
175 885d3e02 2018-01-27 stsp if (o == 0)
176 885d3e02 2018-01-27 stsp o = GOT_DELTA_COPY_DEFAULT_OFF;
177 885d3e02 2018-01-27 stsp if (l == 0)
178 885d3e02 2018-01-27 stsp l = GOT_DELTA_COPY_DEFAULT_LEN;
180 885d3e02 2018-01-27 stsp *offset = o;
182 885d3e02 2018-01-27 stsp return NULL;
185 885d3e02 2018-01-27 stsp static const struct got_error *
186 885d3e02 2018-01-27 stsp copy_from_base(FILE *base_file, off_t offset, size_t size, FILE *outfile)
188 885d3e02 2018-01-27 stsp if (fseeko(base_file, offset, SEEK_SET) != 0)
189 885d3e02 2018-01-27 stsp return got_error_from_errno();
191 885d3e02 2018-01-27 stsp while (size > 0) {
192 885d3e02 2018-01-27 stsp uint8_t data[2048];
193 885d3e02 2018-01-27 stsp size_t len = MIN(size, sizeof(data));
196 885d3e02 2018-01-27 stsp n = fread(data, len, 1, base_file);
197 885d3e02 2018-01-27 stsp if (n != 1)
198 885d3e02 2018-01-27 stsp return got_ferror(base_file, GOT_ERR_IO);
200 885d3e02 2018-01-27 stsp n = fwrite(data, len, 1, outfile);
201 885d3e02 2018-01-27 stsp if (n != 1)
202 885d3e02 2018-01-27 stsp return got_ferror(outfile, GOT_ERR_IO);
204 885d3e02 2018-01-27 stsp size -= len;
207 885d3e02 2018-01-27 stsp return NULL;
210 885d3e02 2018-01-27 stsp static const struct got_error *
211 885d3e02 2018-01-27 stsp copy_from_delta(const uint8_t **p, size_t *remain, size_t len, FILE *outfile)
215 885d3e02 2018-01-27 stsp if (*remain < len)
216 885d3e02 2018-01-27 stsp return got_error(GOT_ERR_BAD_DELTA);
218 885d3e02 2018-01-27 stsp n = fwrite(*p, len, 1, outfile);
219 885d3e02 2018-01-27 stsp if (n != 1)
220 885d3e02 2018-01-27 stsp return got_ferror(outfile, GOT_ERR_IO);
223 885d3e02 2018-01-27 stsp *remain -= len;
224 885d3e02 2018-01-27 stsp return NULL;
227 885d3e02 2018-01-27 stsp const struct got_error *
228 0e22967e 2018-02-11 stsp got_delta_apply(FILE *base_file, const uint8_t *delta_buf,
229 885d3e02 2018-01-27 stsp size_t delta_len, FILE *outfile)
231 885d3e02 2018-01-27 stsp const struct got_error *err = NULL;
232 885d3e02 2018-01-27 stsp uint64_t base_size, result_size;
233 885d3e02 2018-01-27 stsp size_t remain, outsize = 0;
234 885d3e02 2018-01-27 stsp const uint8_t *p;
236 885d3e02 2018-01-27 stsp if (delta_len < GOT_DELTA_STREAM_LENGTH_MIN)
237 885d3e02 2018-01-27 stsp return got_error(GOT_ERR_BAD_DELTA);
239 885d3e02 2018-01-27 stsp p = delta_buf;
240 885d3e02 2018-01-27 stsp remain = delta_len;
242 885d3e02 2018-01-27 stsp /* Read the two size fields at the beginning of the stream. */
243 885d3e02 2018-01-27 stsp err = parse_size(&base_size, &p, &remain);
245 885d3e02 2018-01-27 stsp return err;
246 885d3e02 2018-01-27 stsp err = next_delta_byte(&p, &remain);
248 885d3e02 2018-01-27 stsp return err;
249 885d3e02 2018-01-27 stsp err = parse_size(&result_size, &p, &remain);
251 885d3e02 2018-01-27 stsp return err;
253 885d3e02 2018-01-27 stsp /* Decode and execute copy instructions from the delta stream. */
254 885d3e02 2018-01-27 stsp err = next_delta_byte(&p, &remain);
255 885d3e02 2018-01-27 stsp while (err == NULL) {
256 824801e7 2018-01-27 stsp if (*p & GOT_DELTA_BASE_COPY) {
257 885d3e02 2018-01-27 stsp off_t offset = 0;
258 885d3e02 2018-01-27 stsp size_t len = 0;
259 885d3e02 2018-01-27 stsp err = parse_opcode(&offset, &len, &p, &remain);
262 885d3e02 2018-01-27 stsp err = copy_from_base(base_file, offset, len, outfile);
263 885d3e02 2018-01-27 stsp if (err == NULL)
264 885d3e02 2018-01-27 stsp outsize += len;
266 885d3e02 2018-01-27 stsp size_t len = (size_t)*p;
267 885d3e02 2018-01-27 stsp if (len == 0) {
268 885d3e02 2018-01-27 stsp err = got_error(GOT_ERR_BAD_DELTA);
271 885d3e02 2018-01-27 stsp err = next_delta_byte(&p, &remain);
273 885d3e02 2018-01-27 stsp return err;
274 885d3e02 2018-01-27 stsp err = copy_from_delta(&p, &remain, len, outfile);
275 885d3e02 2018-01-27 stsp if (err == NULL)
276 885d3e02 2018-01-27 stsp outsize += len;
279 885d3e02 2018-01-27 stsp if (err == NULL) {
280 885d3e02 2018-01-27 stsp if (remain == 0)
282 885d3e02 2018-01-27 stsp /* Fetch the next instruction. */
288 885d3e02 2018-01-27 stsp if (outsize != result_size)
289 885d3e02 2018-01-27 stsp err = got_error(GOT_ERR_BAD_DELTA);
291 885d3e02 2018-01-27 stsp if (err == NULL)
292 885d3e02 2018-01-27 stsp rewind(outfile);
293 885d3e02 2018-01-27 stsp return err;
