freshlybakedca.ke
Git fork
1/*
2 * Copyright (c) 2005, 2006 Rene Scharfe
3 */
4
5#define USE_THE_REPOSITORY_VARIABLE
6
7#include "git-compat-util.h"
8#include "config.h"
9#include "gettext.h"
10#include "git-zlib.h"
11#include "hex.h"
12#include "tar.h"
13#include "archive.h"
14#include "odb.h"
15#include "strbuf.h"
16#include "streaming.h"
17#include "run-command.h"
18#include "write-or-die.h"
19
20#define RECORDSIZE (512)
21#define BLOCKSIZE (RECORDSIZE * 20)
22
23static char block[BLOCKSIZE];
24static unsigned long offset;
25
26static int tar_umask = 002;
27
28static int write_tar_filter_archive(const struct archiver *ar,
29 struct archiver_args *args);
30
31/*
32 * This is the max value that a ustar size header can specify, as it is fixed
33 * at 11 octal digits. POSIX specifies that we switch to extended headers at
34 * this size.
35 *
36 * Likewise for the mtime (which happens to use a buffer of the same size).
37 */
38#if ULONG_MAX == 0xFFFFFFFF
39#define USTAR_MAX_SIZE ULONG_MAX
40#else
41#define USTAR_MAX_SIZE 077777777777UL
42#endif
43#if TIME_MAX == 0xFFFFFFFF
44#define USTAR_MAX_MTIME TIME_MAX
45#else
46#define USTAR_MAX_MTIME 077777777777ULL
47#endif
48
49static void tar_write_block(const void *buf)
50{
51 write_or_die(1, buf, BLOCKSIZE);
52}
53
54static void (*write_block)(const void *) = tar_write_block;
55
56/* writes out the whole block, but only if it is full */
57static void write_if_needed(void)
58{
59 if (offset == BLOCKSIZE) {
60 write_block(block);
61 offset = 0;
62 }
63}
64
65/*
66 * queues up writes, so that all our write(2) calls write exactly one
67 * full block; pads writes to RECORDSIZE
68 */
69static void do_write_blocked(const void *data, unsigned long size)
70{
71 const char *buf = data;
72
73 if (offset) {
74 unsigned long chunk = BLOCKSIZE - offset;
75 if (size < chunk)
76 chunk = size;
77 memcpy(block + offset, buf, chunk);
78 size -= chunk;
79 offset += chunk;
80 buf += chunk;
81 write_if_needed();
82 }
83 while (size >= BLOCKSIZE) {
84 write_block(buf);
85 size -= BLOCKSIZE;
86 buf += BLOCKSIZE;
87 }
88 if (size) {
89 memcpy(block + offset, buf, size);
90 offset += size;
91 }
92}
93
94static void finish_record(void)
95{
96 unsigned long tail;
97 tail = offset % RECORDSIZE;
98 if (tail) {
99 memset(block + offset, 0, RECORDSIZE - tail);
100 offset += RECORDSIZE - tail;
101 }
102 write_if_needed();
103}
104
105static void write_blocked(const void *data, unsigned long size)
106{
107 do_write_blocked(data, size);
108 finish_record();
109}
110
111/*
112 * The end of tar archives is marked by 2*512 nul bytes and after that
113 * follows the rest of the block (if any).
114 */
115static void write_trailer(void)
116{
117 int tail = BLOCKSIZE - offset;
118 memset(block + offset, 0, tail);
119 write_block(block);
120 if (tail < 2 * RECORDSIZE) {
121 memset(block, 0, offset);
122 write_block(block);
123 }
124}
125
126/*
127 * queues up writes, so that all our write(2) calls write exactly one
128 * full block; pads writes to RECORDSIZE
129 */
130static int stream_blocked(struct repository *r, const struct object_id *oid)
131{
132 struct git_istream *st;
133 enum object_type type;
134 unsigned long sz;
135 char buf[BLOCKSIZE];
136 ssize_t readlen;
137
138 st = open_istream(r, oid, &type, &sz, NULL);
139 if (!st)
140 return error(_("cannot stream blob %s"), oid_to_hex(oid));
141 for (;;) {
142 readlen = read_istream(st, buf, sizeof(buf));
143 if (readlen <= 0)
144 break;
145 do_write_blocked(buf, readlen);
146 }
147 close_istream(st);
148 if (!readlen)
149 finish_record();
150 return readlen;
151}
152
153/*
154 * pax extended header records have the format "%u %s=%s\n". %u contains
155 * the size of the whole string (including the %u), the first %s is the
156 * keyword, the second one is the value. This function constructs such a
157 * string and appends it to a struct strbuf.
158 */
159static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
160 const char *value, size_t valuelen)
161{
162 size_t orig_len = sb->len;
163 size_t len, tmp;
164
165 /* "%u %s=%s\n" */
166 len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
167 for (tmp = 1; len / 10 >= tmp; tmp *= 10)
168 len++;
169
170 strbuf_grow(sb, len);
171 strbuf_addf(sb, "%"PRIuMAX" %s=", (uintmax_t)len, keyword);
172 strbuf_add(sb, value, valuelen);
173 strbuf_addch(sb, '\n');
174
175 if (len != sb->len - orig_len)
176 BUG("pax extended header length miscalculated as %"PRIuMAX
177 ", should be %"PRIuMAX,
178 (uintmax_t)len, (uintmax_t)(sb->len - orig_len));
179}
180
181/*
182 * Like strbuf_append_ext_header, but for numeric values.
183 */
184static void strbuf_append_ext_header_uint(struct strbuf *sb,
185 const char *keyword,
186 uintmax_t value)
187{
188 char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
189 int len;
190
191 len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
192 strbuf_append_ext_header(sb, keyword, buf, len);
193}
194
195static unsigned int ustar_header_chksum(const struct ustar_header *header)
196{
197 const unsigned char *p = (const unsigned char *)header;
198 unsigned int chksum = 0;
199 while (p < (const unsigned char *)header->chksum)
200 chksum += *p++;
201 chksum += sizeof(header->chksum) * ' ';
202 p += sizeof(header->chksum);
203 while (p < (const unsigned char *)header + sizeof(struct ustar_header))
204 chksum += *p++;
205 return chksum;
206}
207
208static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
209{
210 size_t i = pathlen;
211 if (i > 1 && path[i - 1] == '/')
212 i--;
213 if (i > maxlen)
214 i = maxlen;
215 do {
216 i--;
217 } while (i > 0 && path[i] != '/');
218 return i;
219}
220
221static void prepare_header(struct archiver_args *args,
222 struct ustar_header *header,
223 unsigned int mode, unsigned long size)
224{
225 xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
226 xsnprintf(header->size, sizeof(header->size), "%011"PRIoMAX , S_ISREG(mode) ? (uintmax_t)size : (uintmax_t)0);
227 xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
228
229 xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
230 xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
231 strlcpy(header->uname, "root", sizeof(header->uname));
232 strlcpy(header->gname, "root", sizeof(header->gname));
233 xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
234 xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
235
236 memcpy(header->magic, "ustar", 6);
237 memcpy(header->version, "00", 2);
238
239 xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
240}
241
242static void write_extended_header(struct archiver_args *args,
243 const struct object_id *oid,
244 const void *buffer, unsigned long size)
245{
246 struct ustar_header header;
247 unsigned int mode;
248 memset(&header, 0, sizeof(header));
249 *header.typeflag = TYPEFLAG_EXT_HEADER;
250 mode = 0100666;
251 xsnprintf(header.name, sizeof(header.name), "%s.paxheader", oid_to_hex(oid));
252 prepare_header(args, &header, mode, size);
253 write_blocked(&header, sizeof(header));
254 write_blocked(buffer, size);
255}
256
257static int write_tar_entry(struct archiver_args *args,
258 const struct object_id *oid,
259 const char *path, size_t pathlen,
260 unsigned int mode,
261 void *buffer, unsigned long size)
262{
263 struct ustar_header header;
264 struct strbuf ext_header = STRBUF_INIT;
265 unsigned long size_in_header;
266 int err = 0;
267
268 memset(&header, 0, sizeof(header));
269
270 if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
271 *header.typeflag = TYPEFLAG_DIR;
272 mode = (mode | 0777) & ~tar_umask;
273 } else if (S_ISLNK(mode)) {
274 *header.typeflag = TYPEFLAG_LNK;
275 mode |= 0777;
276 } else if (S_ISREG(mode)) {
277 *header.typeflag = TYPEFLAG_REG;
278 mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
279 } else {
280 return error(_("unsupported file mode: 0%o (SHA1: %s)"),
281 mode, oid_to_hex(oid));
282 }
283 if (pathlen > sizeof(header.name)) {
284 size_t plen = get_path_prefix(path, pathlen,
285 sizeof(header.prefix));
286 size_t rest = pathlen - plen - 1;
287 if (plen > 0 && rest <= sizeof(header.name)) {
288 memcpy(header.prefix, path, plen);
289 memcpy(header.name, path + plen + 1, rest);
290 } else {
291 xsnprintf(header.name, sizeof(header.name), "%s.data",
292 oid_to_hex(oid));
293 strbuf_append_ext_header(&ext_header, "path",
294 path, pathlen);
295 }
296 } else
297 memcpy(header.name, path, pathlen);
298
299 if (S_ISLNK(mode)) {
300 if (size > sizeof(header.linkname)) {
301 xsnprintf(header.linkname, sizeof(header.linkname),
302 "see %s.paxheader", oid_to_hex(oid));
303 strbuf_append_ext_header(&ext_header, "linkpath",
304 buffer, size);
305 } else
306 memcpy(header.linkname, buffer, size);
307 }
308
309 size_in_header = size;
310 if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
311 size_in_header = 0;
312 strbuf_append_ext_header_uint(&ext_header, "size", size);
313 }
314
315 prepare_header(args, &header, mode, size_in_header);
316
317 if (ext_header.len > 0) {
318 write_extended_header(args, oid, ext_header.buf,
319 ext_header.len);
320 }
321 strbuf_release(&ext_header);
322 write_blocked(&header, sizeof(header));
323 if (S_ISREG(mode) && size > 0) {
324 if (buffer)
325 write_blocked(buffer, size);
326 else
327 err = stream_blocked(args->repo, oid);
328 }
329 return err;
330}
331
332static void write_global_extended_header(struct archiver_args *args)
333{
334 const struct object_id *oid = args->commit_oid;
335 struct strbuf ext_header = STRBUF_INIT;
336 struct ustar_header header;
337 unsigned int mode;
338
339 if (oid)
340 strbuf_append_ext_header(&ext_header, "comment",
341 oid_to_hex(oid),
342 the_hash_algo->hexsz);
343 if (args->time > USTAR_MAX_MTIME) {
344 strbuf_append_ext_header_uint(&ext_header, "mtime",
345 args->time);
346 args->time = USTAR_MAX_MTIME;
347 }
348
349 if (!ext_header.len)
350 return;
351
352 memset(&header, 0, sizeof(header));
353 *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
354 mode = 0100666;
355 xsnprintf(header.name, sizeof(header.name), "pax_global_header");
356 prepare_header(args, &header, mode, ext_header.len);
357 write_blocked(&header, sizeof(header));
358 write_blocked(ext_header.buf, ext_header.len);
359 strbuf_release(&ext_header);
360}
361
362static struct archiver **tar_filters;
363static int nr_tar_filters;
364static int alloc_tar_filters;
365
366static struct archiver *find_tar_filter(const char *name, size_t len)
367{
368 int i;
369 for (i = 0; i < nr_tar_filters; i++) {
370 struct archiver *ar = tar_filters[i];
371 if (!xstrncmpz(ar->name, name, len))
372 return ar;
373 }
374 return NULL;
375}
376
377static int tar_filter_config(const char *var, const char *value,
378 void *data UNUSED)
379{
380 struct archiver *ar;
381 const char *name;
382 const char *type;
383 size_t namelen;
384
385 if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 || !name)
386 return 0;
387
388 ar = find_tar_filter(name, namelen);
389 if (!ar) {
390 CALLOC_ARRAY(ar, 1);
391 ar->name = xmemdupz(name, namelen);
392 ar->write_archive = write_tar_filter_archive;
393 ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS |
394 ARCHIVER_HIGH_COMPRESSION_LEVELS;
395 ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
396 tar_filters[nr_tar_filters++] = ar;
397 }
398
399 if (!strcmp(type, "command")) {
400 if (!value)
401 return config_error_nonbool(var);
402 free(ar->filter_command);
403 ar->filter_command = xstrdup(value);
404 return 0;
405 }
406 if (!strcmp(type, "remote")) {
407 if (git_config_bool(var, value))
408 ar->flags |= ARCHIVER_REMOTE;
409 else
410 ar->flags &= ~ARCHIVER_REMOTE;
411 return 0;
412 }
413
414 return 0;
415}
416
417static int git_tar_config(const char *var, const char *value,
418 const struct config_context *ctx, void *cb)
419{
420 if (!strcmp(var, "tar.umask")) {
421 if (value && !strcmp(value, "user")) {
422 tar_umask = umask(0);
423 umask(tar_umask);
424 } else {
425 tar_umask = git_config_int(var, value, ctx->kvi);
426 }
427 return 0;
428 }
429
430 return tar_filter_config(var, value, cb);
431}
432
433static int write_tar_archive(const struct archiver *ar UNUSED,
434 struct archiver_args *args)
435{
436 int err = 0;
437
438 write_global_extended_header(args);
439 err = write_archive_entries(args, write_tar_entry);
440 if (!err)
441 write_trailer();
442 return err;
443}
444
445static git_zstream gzstream;
446static unsigned char outbuf[16384];
447
448static void tgz_deflate(int flush)
449{
450 while (gzstream.avail_in || flush == Z_FINISH) {
451 int status = git_deflate(&gzstream, flush);
452 if (!gzstream.avail_out || status == Z_STREAM_END) {
453 write_or_die(1, outbuf, gzstream.next_out - outbuf);
454 gzstream.next_out = outbuf;
455 gzstream.avail_out = sizeof(outbuf);
456 if (status == Z_STREAM_END)
457 break;
458 }
459 if (status != Z_OK && status != Z_BUF_ERROR)
460 die(_("deflate error (%d)"), status);
461 }
462}
463
464static void tgz_write_block(const void *data)
465{
466 gzstream.next_in = (void *)data;
467 gzstream.avail_in = BLOCKSIZE;
468 tgz_deflate(Z_NO_FLUSH);
469}
470
471static const char internal_gzip_command[] = "git archive gzip";
472
473static int write_tar_filter_archive(const struct archiver *ar,
474 struct archiver_args *args)
475{
476 struct gz_header_s gzhead = { .os = 3 }; /* Unix, for reproducibility */
477 struct strbuf cmd = STRBUF_INIT;
478 struct child_process filter = CHILD_PROCESS_INIT;
479 int r;
480
481 if (!ar->filter_command)
482 BUG("tar-filter archiver called with no filter defined");
483
484 if (!strcmp(ar->filter_command, internal_gzip_command)) {
485 write_block = tgz_write_block;
486 git_deflate_init_gzip(&gzstream, args->compression_level);
487 if (deflateSetHeader(&gzstream.z, &gzhead) != Z_OK)
488 BUG("deflateSetHeader() called too late");
489 gzstream.next_out = outbuf;
490 gzstream.avail_out = sizeof(outbuf);
491
492 r = write_tar_archive(ar, args);
493
494 tgz_deflate(Z_FINISH);
495 git_deflate_end(&gzstream);
496 return r;
497 }
498
499 strbuf_addstr(&cmd, ar->filter_command);
500 if (args->compression_level >= 0)
501 strbuf_addf(&cmd, " -%d", args->compression_level);
502
503 strvec_push(&filter.args, cmd.buf);
504 filter.use_shell = 1;
505 filter.in = -1;
506 filter.silent_exec_failure = 1;
507
508 if (start_command(&filter) < 0)
509 die_errno(_("unable to start '%s' filter"), cmd.buf);
510 close(1);
511 if (dup2(filter.in, 1) < 0)
512 die_errno(_("unable to redirect descriptor"));
513 close(filter.in);
514
515 r = write_tar_archive(ar, args);
516
517 close(1);
518 if (finish_command(&filter) != 0)
519 die(_("'%s' filter reported error"), cmd.buf);
520
521 strbuf_release(&cmd);
522 return r;
523}
524
525static struct archiver tar_archiver = {
526 .name = "tar",
527 .write_archive = write_tar_archive,
528 .flags = ARCHIVER_REMOTE,
529};
530
531void init_tar_archiver(void)
532{
533 int i;
534 register_archiver(&tar_archiver);
535
536 tar_filter_config("tar.tgz.command", internal_gzip_command, NULL);
537 tar_filter_config("tar.tgz.remote", "true", NULL);
538 tar_filter_config("tar.tar.gz.command", internal_gzip_command, NULL);
539 tar_filter_config("tar.tar.gz.remote", "true", NULL);
540 repo_config(the_repository, git_tar_config, NULL);
541 for (i = 0; i < nr_tar_filters; i++) {
542 /* omit any filters that never had a command configured */
543 if (tar_filters[i]->filter_command)
544 register_archiver(tar_filters[i]);
545 }
546}