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3d74982f
RS
1/*
2 * Copyright (c) 2005, 2006 Rene Scharfe
3 */
3d74982f 4#include "cache.h"
b2141fc1 5#include "config.h"
3d74982f 6#include "tar.h"
3d74982f 7#include "archive.h"
cbd53a21 8#include "object-store.h"
5544049d 9#include "streaming.h"
767cf457 10#include "run-command.h"
3d74982f
RS
11
12#define RECORDSIZE (512)
13#define BLOCKSIZE (RECORDSIZE * 20)
14
15static char block[BLOCKSIZE];
16static unsigned long offset;
17
f08b3b0e 18static int tar_umask = 002;
3d74982f 19
767cf457
JK
20static int write_tar_filter_archive(const struct archiver *ar,
21 struct archiver_args *args);
22
d1657b57
JK
23/*
24 * This is the max value that a ustar size header can specify, as it is fixed
25 * at 11 octal digits. POSIX specifies that we switch to extended headers at
26 * this size.
6e8e0991
JK
27 *
28 * Likewise for the mtime (which happens to use a buffer of the same size).
d1657b57 29 */
29493589
JH
30#if ULONG_MAX == 0xFFFFFFFF
31#define USTAR_MAX_SIZE ULONG_MAX
29493589 32#else
3f789719 33#define USTAR_MAX_SIZE 077777777777UL
dddbad72
JS
34#endif
35#if TIME_MAX == 0xFFFFFFFF
36#define USTAR_MAX_MTIME TIME_MAX
37#else
3f789719 38#define USTAR_MAX_MTIME 077777777777ULL
29493589 39#endif
d1657b57 40
3d74982f
RS
41/* writes out the whole block, but only if it is full */
42static void write_if_needed(void)
43{
44 if (offset == BLOCKSIZE) {
45 write_or_die(1, block, BLOCKSIZE);
46 offset = 0;
47 }
48}
49
50/*
51 * queues up writes, so that all our write(2) calls write exactly one
52 * full block; pads writes to RECORDSIZE
53 */
5544049d 54static void do_write_blocked(const void *data, unsigned long size)
3d74982f
RS
55{
56 const char *buf = data;
3d74982f
RS
57
58 if (offset) {
59 unsigned long chunk = BLOCKSIZE - offset;
60 if (size < chunk)
61 chunk = size;
62 memcpy(block + offset, buf, chunk);
63 size -= chunk;
64 offset += chunk;
65 buf += chunk;
66 write_if_needed();
67 }
68 while (size >= BLOCKSIZE) {
69 write_or_die(1, buf, BLOCKSIZE);
70 size -= BLOCKSIZE;
71 buf += BLOCKSIZE;
72 }
73 if (size) {
74 memcpy(block + offset, buf, size);
75 offset += size;
76 }
5544049d
NTND
77}
78
79static void finish_record(void)
80{
81 unsigned long tail;
3d74982f
RS
82 tail = offset % RECORDSIZE;
83 if (tail) {
84 memset(block + offset, 0, RECORDSIZE - tail);
85 offset += RECORDSIZE - tail;
86 }
87 write_if_needed();
88}
89
5544049d
NTND
90static void write_blocked(const void *data, unsigned long size)
91{
92 do_write_blocked(data, size);
93 finish_record();
94}
95
3d74982f
RS
96/*
97 * The end of tar archives is marked by 2*512 nul bytes and after that
98 * follows the rest of the block (if any).
99 */
100static void write_trailer(void)
101{
102 int tail = BLOCKSIZE - offset;
103 memset(block + offset, 0, tail);
104 write_or_die(1, block, BLOCKSIZE);
105 if (tail < 2 * RECORDSIZE) {
106 memset(block, 0, offset);
107 write_or_die(1, block, BLOCKSIZE);
108 }
109}
110
5544049d
NTND
111/*
112 * queues up writes, so that all our write(2) calls write exactly one
113 * full block; pads writes to RECORDSIZE
114 */
c8123e72 115static int stream_blocked(struct repository *r, const struct object_id *oid)
5544049d
NTND
116{
117 struct git_istream *st;
118 enum object_type type;
119 unsigned long sz;
120 char buf[BLOCKSIZE];
121 ssize_t readlen;
122
c8123e72 123 st = open_istream(r, oid, &type, &sz, NULL);
5544049d 124 if (!st)
d0482e69 125 return error(_("cannot stream blob %s"), oid_to_hex(oid));
5544049d
NTND
126 for (;;) {
127 readlen = read_istream(st, buf, sizeof(buf));
128 if (readlen <= 0)
129 break;
130 do_write_blocked(buf, readlen);
131 }
132 close_istream(st);
133 if (!readlen)
134 finish_record();
135 return readlen;
136}
137
3d74982f
RS
138/*
139 * pax extended header records have the format "%u %s=%s\n". %u contains
140 * the size of the whole string (including the %u), the first %s is the
141 * keyword, the second one is the value. This function constructs such a
142 * string and appends it to a struct strbuf.
143 */
144static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
17e9ef00 145 const char *value, size_t valuelen)
3d74982f 146{
4060c199 147 size_t orig_len = sb->len;
17e9ef00 148 size_t len, tmp;
3d74982f
RS
149
150 /* "%u %s=%s\n" */
151 len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
82a46af1 152 for (tmp = 1; len / 10 >= tmp; tmp *= 10)
3d74982f
RS
153 len++;
154
7a604f16 155 strbuf_grow(sb, len);
17e9ef00 156 strbuf_addf(sb, "%"PRIuMAX" %s=", (uintmax_t)len, keyword);
7a604f16
PH
157 strbuf_add(sb, value, valuelen);
158 strbuf_addch(sb, '\n');
4060c199
RS
159
160 if (len != sb->len - orig_len)
71d41ff6
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161 BUG("pax extended header length miscalculated as %"PRIuMAX
162 ", should be %"PRIuMAX,
163 (uintmax_t)len, (uintmax_t)(sb->len - orig_len));
3d74982f
RS
164}
165
d1657b57
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166/*
167 * Like strbuf_append_ext_header, but for numeric values.
168 */
169static void strbuf_append_ext_header_uint(struct strbuf *sb,
170 const char *keyword,
171 uintmax_t value)
172{
173 char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
174 int len;
175
176 len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
177 strbuf_append_ext_header(sb, keyword, buf, len);
178}
179
3d74982f
RS
180static unsigned int ustar_header_chksum(const struct ustar_header *header)
181{
a5a46eb9 182 const unsigned char *p = (const unsigned char *)header;
3d74982f 183 unsigned int chksum = 0;
a5a46eb9 184 while (p < (const unsigned char *)header->chksum)
3d74982f
RS
185 chksum += *p++;
186 chksum += sizeof(header->chksum) * ' ';
187 p += sizeof(header->chksum);
a5a46eb9 188 while (p < (const unsigned char *)header + sizeof(struct ustar_header))
3d74982f
RS
189 chksum += *p++;
190 return chksum;
191}
192
562e25ab 193static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
3d74982f 194{
562e25ab 195 size_t i = pathlen;
22f0dcd9
RS
196 if (i > 1 && path[i - 1] == '/')
197 i--;
3d74982f
RS
198 if (i > maxlen)
199 i = maxlen;
200 do {
201 i--;
562e25ab 202 } while (i > 0 && path[i] != '/');
3d74982f
RS
203 return i;
204}
205
d240d410
NTND
206static void prepare_header(struct archiver_args *args,
207 struct ustar_header *header,
208 unsigned int mode, unsigned long size)
209{
f2f02675 210 xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
ca473cef 211 xsnprintf(header->size, sizeof(header->size), "%011"PRIoMAX , S_ISREG(mode) ? (uintmax_t)size : (uintmax_t)0);
f2f02675 212 xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
d240d410 213
f2f02675
JK
214 xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
215 xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
d240d410
NTND
216 strlcpy(header->uname, "root", sizeof(header->uname));
217 strlcpy(header->gname, "root", sizeof(header->gname));
f2f02675
JK
218 xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
219 xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
d240d410
NTND
220
221 memcpy(header->magic, "ustar", 6);
222 memcpy(header->version, "00", 2);
223
9e6c1e91 224 xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
d240d410
NTND
225}
226
560b0e8f 227static void write_extended_header(struct archiver_args *args,
015ff4f8 228 const struct object_id *oid,
560b0e8f 229 const void *buffer, unsigned long size)
d240d410
NTND
230{
231 struct ustar_header header;
232 unsigned int mode;
233 memset(&header, 0, sizeof(header));
234 *header.typeflag = TYPEFLAG_EXT_HEADER;
15c6ef7b 235 mode = 0100666;
015ff4f8 236 xsnprintf(header.name, sizeof(header.name), "%s.paxheader", oid_to_hex(oid));
d240d410
NTND
237 prepare_header(args, &header, mode, size);
238 write_blocked(&header, sizeof(header));
239 write_blocked(buffer, size);
d240d410
NTND
240}
241
562e25ab 242static int write_tar_entry(struct archiver_args *args,
015ff4f8 243 const struct object_id *oid,
9cb513b7 244 const char *path, size_t pathlen,
200589ab
RS
245 unsigned int mode,
246 void *buffer, unsigned long size)
3d74982f
RS
247{
248 struct ustar_header header;
f285a2d7 249 struct strbuf ext_header = STRBUF_INIT;
200589ab 250 unsigned long size_in_header;
562e25ab 251 int err = 0;
3d74982f
RS
252
253 memset(&header, 0, sizeof(header));
3d74982f 254
85390709
NTND
255 if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
256 *header.typeflag = TYPEFLAG_DIR;
257 mode = (mode | 0777) & ~tar_umask;
258 } else if (S_ISLNK(mode)) {
259 *header.typeflag = TYPEFLAG_LNK;
260 mode |= 0777;
261 } else if (S_ISREG(mode)) {
262 *header.typeflag = TYPEFLAG_REG;
263 mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
3d74982f 264 } else {
d0482e69 265 return error(_("unsupported file mode: 0%o (SHA1: %s)"),
015ff4f8 266 mode, oid_to_hex(oid));
85390709
NTND
267 }
268 if (pathlen > sizeof(header.name)) {
269 size_t plen = get_path_prefix(path, pathlen,
270 sizeof(header.prefix));
271 size_t rest = pathlen - plen - 1;
272 if (plen > 0 && rest <= sizeof(header.name)) {
273 memcpy(header.prefix, path, plen);
108332c7 274 memcpy(header.name, path + plen + 1, rest);
3d74982f 275 } else {
f2f02675 276 xsnprintf(header.name, sizeof(header.name), "%s.data",
015ff4f8 277 oid_to_hex(oid));
85390709
NTND
278 strbuf_append_ext_header(&ext_header, "path",
279 path, pathlen);
3d74982f 280 }
85390709
NTND
281 } else
282 memcpy(header.name, path, pathlen);
3d74982f 283
9cb513b7 284 if (S_ISLNK(mode)) {
3d74982f 285 if (size > sizeof(header.linkname)) {
f2f02675 286 xsnprintf(header.linkname, sizeof(header.linkname),
015ff4f8 287 "see %s.paxheader", oid_to_hex(oid));
3d74982f
RS
288 strbuf_append_ext_header(&ext_header, "linkpath",
289 buffer, size);
290 } else
291 memcpy(header.linkname, buffer, size);
292 }
293
d1657b57
JK
294 size_in_header = size;
295 if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
296 size_in_header = 0;
297 strbuf_append_ext_header_uint(&ext_header, "size", size);
298 }
299
300 prepare_header(args, &header, mode, size_in_header);
3d74982f
RS
301
302 if (ext_header.len > 0) {
015ff4f8 303 write_extended_header(args, oid, ext_header.buf,
560b0e8f 304 ext_header.len);
3d74982f 305 }
7a604f16 306 strbuf_release(&ext_header);
3d74982f 307 write_blocked(&header, sizeof(header));
5544049d
NTND
308 if (S_ISREG(mode) && size > 0) {
309 if (buffer)
310 write_blocked(buffer, size);
311 else
c8123e72 312 err = stream_blocked(args->repo, oid);
5544049d 313 }
562e25ab 314 return err;
3d74982f
RS
315}
316
5caeeb83 317static void write_global_extended_header(struct archiver_args *args)
3d74982f 318{
bbf05cf7 319 const struct object_id *oid = args->commit_oid;
f285a2d7 320 struct strbuf ext_header = STRBUF_INIT;
d240d410
NTND
321 struct ustar_header header;
322 unsigned int mode;
7a604f16 323
bbf05cf7 324 if (oid)
6e8e0991 325 strbuf_append_ext_header(&ext_header, "comment",
bbf05cf7 326 oid_to_hex(oid),
327 the_hash_algo->hexsz);
6e8e0991
JK
328 if (args->time > USTAR_MAX_MTIME) {
329 strbuf_append_ext_header_uint(&ext_header, "mtime",
330 args->time);
331 args->time = USTAR_MAX_MTIME;
332 }
333
334 if (!ext_header.len)
5caeeb83 335 return;
6e8e0991 336
d240d410
NTND
337 memset(&header, 0, sizeof(header));
338 *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
15c6ef7b 339 mode = 0100666;
5096d490 340 xsnprintf(header.name, sizeof(header.name), "pax_global_header");
d240d410
NTND
341 prepare_header(args, &header, mode, ext_header.len);
342 write_blocked(&header, sizeof(header));
343 write_blocked(ext_header.buf, ext_header.len);
7a604f16 344 strbuf_release(&ext_header);
3d74982f
RS
345}
346
767cf457
JK
347static struct archiver **tar_filters;
348static int nr_tar_filters;
349static int alloc_tar_filters;
350
f5914f4b 351static struct archiver *find_tar_filter(const char *name, size_t len)
767cf457
JK
352{
353 int i;
354 for (i = 0; i < nr_tar_filters; i++) {
355 struct archiver *ar = tar_filters[i];
356 if (!strncmp(ar->name, name, len) && !ar->name[len])
357 return ar;
358 }
359 return NULL;
360}
361
362static int tar_filter_config(const char *var, const char *value, void *data)
363{
364 struct archiver *ar;
767cf457
JK
365 const char *name;
366 const char *type;
f5914f4b 367 size_t namelen;
767cf457 368
785a0429 369 if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 || !name)
767cf457 370 return 0;
767cf457
JK
371
372 ar = find_tar_filter(name, namelen);
373 if (!ar) {
ca56dadb 374 CALLOC_ARRAY(ar, 1);
767cf457
JK
375 ar->name = xmemdupz(name, namelen);
376 ar->write_archive = write_tar_filter_archive;
cde8ea9c
RS
377 ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS |
378 ARCHIVER_HIGH_COMPRESSION_LEVELS;
767cf457
JK
379 ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
380 tar_filters[nr_tar_filters++] = ar;
381 }
382
383 if (!strcmp(type, "command")) {
384 if (!value)
385 return config_error_nonbool(var);
386 free(ar->data);
387 ar->data = xstrdup(value);
388 return 0;
389 }
7b97730b
JK
390 if (!strcmp(type, "remote")) {
391 if (git_config_bool(var, value))
392 ar->flags |= ARCHIVER_REMOTE;
393 else
394 ar->flags &= ~ARCHIVER_REMOTE;
395 return 0;
396 }
767cf457
JK
397
398 return 0;
399}
400
ef90d6d4 401static int git_tar_config(const char *var, const char *value, void *cb)
3d74982f
RS
402{
403 if (!strcmp(var, "tar.umask")) {
cc1816b0 404 if (value && !strcmp(value, "user")) {
3d74982f
RS
405 tar_umask = umask(0);
406 umask(tar_umask);
407 } else {
408 tar_umask = git_config_int(var, value);
409 }
410 return 0;
411 }
767cf457
JK
412
413 return tar_filter_config(var, value, cb);
3d74982f
RS
414}
415
4d7c9898
JK
416static int write_tar_archive(const struct archiver *ar,
417 struct archiver_args *args)
3d74982f 418{
562e25ab 419 int err = 0;
3d74982f 420
5caeeb83
JK
421 write_global_extended_header(args);
422 err = write_archive_entries(args, write_tar_entry);
562e25ab
RS
423 if (!err)
424 write_trailer();
425 return err;
3d74982f 426}
13e0f88d 427
767cf457
JK
428static int write_tar_filter_archive(const struct archiver *ar,
429 struct archiver_args *args)
430{
431 struct strbuf cmd = STRBUF_INIT;
d3180279 432 struct child_process filter = CHILD_PROCESS_INIT;
767cf457
JK
433 const char *argv[2];
434 int r;
435
436 if (!ar->data)
033abf97 437 BUG("tar-filter archiver called with no filter defined");
767cf457
JK
438
439 strbuf_addstr(&cmd, ar->data);
440 if (args->compression_level >= 0)
441 strbuf_addf(&cmd, " -%d", args->compression_level);
442
767cf457
JK
443 argv[0] = cmd.buf;
444 argv[1] = NULL;
445 filter.argv = argv;
446 filter.use_shell = 1;
447 filter.in = -1;
448
449 if (start_command(&filter) < 0)
d0482e69 450 die_errno(_("unable to start '%s' filter"), argv[0]);
767cf457
JK
451 close(1);
452 if (dup2(filter.in, 1) < 0)
d0482e69 453 die_errno(_("unable to redirect descriptor"));
767cf457
JK
454 close(filter.in);
455
456 r = write_tar_archive(ar, args);
457
458 close(1);
459 if (finish_command(&filter) != 0)
d0482e69 460 die(_("'%s' filter reported error"), argv[0]);
767cf457
JK
461
462 strbuf_release(&cmd);
463 return r;
464}
465
13e0f88d
JK
466static struct archiver tar_archiver = {
467 "tar",
468 write_tar_archive,
7b97730b 469 ARCHIVER_REMOTE
13e0f88d
JK
470};
471
472void init_tar_archiver(void)
473{
767cf457 474 int i;
13e0f88d 475 register_archiver(&tar_archiver);
767cf457 476
0e804e09 477 tar_filter_config("tar.tgz.command", "gzip -cn", NULL);
7b97730b 478 tar_filter_config("tar.tgz.remote", "true", NULL);
0e804e09 479 tar_filter_config("tar.tar.gz.command", "gzip -cn", NULL);
7b97730b 480 tar_filter_config("tar.tar.gz.remote", "true", NULL);
13e0f88d 481 git_config(git_tar_config, NULL);
767cf457
JK
482 for (i = 0; i < nr_tar_filters; i++) {
483 /* omit any filters that never had a command configured */
484 if (tar_filters[i]->data)
485 register_archiver(tar_filters[i]);
486 }
13e0f88d 487}