gitweb: Allow arbitrary strings to be dug with pickaxe
[git/git.git] / archive-tar.c
CommitLineData
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1/*
2 * Copyright (c) 2005, 2006 Rene Scharfe
3 */
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4#include "cache.h"
5#include "commit.h"
6#include "strbuf.h"
7#include "tar.h"
8#include "builtin.h"
9#include "archive.h"
10
11#define RECORDSIZE (512)
12#define BLOCKSIZE (RECORDSIZE * 20)
13
14static char block[BLOCKSIZE];
15static unsigned long offset;
16
17static time_t archive_time;
f08b3b0e 18static int tar_umask = 002;
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19static int verbose;
20
21/* writes out the whole block, but only if it is full */
22static void write_if_needed(void)
23{
24 if (offset == BLOCKSIZE) {
25 write_or_die(1, block, BLOCKSIZE);
26 offset = 0;
27 }
28}
29
30/*
31 * queues up writes, so that all our write(2) calls write exactly one
32 * full block; pads writes to RECORDSIZE
33 */
34static void write_blocked(const void *data, unsigned long size)
35{
36 const char *buf = data;
37 unsigned long tail;
38
39 if (offset) {
40 unsigned long chunk = BLOCKSIZE - offset;
41 if (size < chunk)
42 chunk = size;
43 memcpy(block + offset, buf, chunk);
44 size -= chunk;
45 offset += chunk;
46 buf += chunk;
47 write_if_needed();
48 }
49 while (size >= BLOCKSIZE) {
50 write_or_die(1, buf, BLOCKSIZE);
51 size -= BLOCKSIZE;
52 buf += BLOCKSIZE;
53 }
54 if (size) {
55 memcpy(block + offset, buf, size);
56 offset += size;
57 }
58 tail = offset % RECORDSIZE;
59 if (tail) {
60 memset(block + offset, 0, RECORDSIZE - tail);
61 offset += RECORDSIZE - tail;
62 }
63 write_if_needed();
64}
65
66/*
67 * The end of tar archives is marked by 2*512 nul bytes and after that
68 * follows the rest of the block (if any).
69 */
70static void write_trailer(void)
71{
72 int tail = BLOCKSIZE - offset;
73 memset(block + offset, 0, tail);
74 write_or_die(1, block, BLOCKSIZE);
75 if (tail < 2 * RECORDSIZE) {
76 memset(block, 0, offset);
77 write_or_die(1, block, BLOCKSIZE);
78 }
79}
80
81static void strbuf_append_string(struct strbuf *sb, const char *s)
82{
83 int slen = strlen(s);
84 int total = sb->len + slen;
85 if (total > sb->alloc) {
86 sb->buf = xrealloc(sb->buf, total);
87 sb->alloc = total;
88 }
89 memcpy(sb->buf + sb->len, s, slen);
90 sb->len = total;
91}
92
93/*
94 * pax extended header records have the format "%u %s=%s\n". %u contains
95 * the size of the whole string (including the %u), the first %s is the
96 * keyword, the second one is the value. This function constructs such a
97 * string and appends it to a struct strbuf.
98 */
99static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
100 const char *value, unsigned int valuelen)
101{
102 char *p;
103 int len, total, tmp;
104
105 /* "%u %s=%s\n" */
106 len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
107 for (tmp = len; tmp > 9; tmp /= 10)
108 len++;
109
110 total = sb->len + len;
111 if (total > sb->alloc) {
112 sb->buf = xrealloc(sb->buf, total);
113 sb->alloc = total;
114 }
115
116 p = sb->buf;
117 p += sprintf(p, "%u %s=", len, keyword);
118 memcpy(p, value, valuelen);
119 p += valuelen;
120 *p = '\n';
121 sb->len = total;
122}
123
124static unsigned int ustar_header_chksum(const struct ustar_header *header)
125{
126 char *p = (char *)header;
127 unsigned int chksum = 0;
128 while (p < header->chksum)
129 chksum += *p++;
130 chksum += sizeof(header->chksum) * ' ';
131 p += sizeof(header->chksum);
132 while (p < (char *)header + sizeof(struct ustar_header))
133 chksum += *p++;
134 return chksum;
135}
136
137static int get_path_prefix(const struct strbuf *path, int maxlen)
138{
139 int i = path->len;
140 if (i > maxlen)
141 i = maxlen;
142 do {
143 i--;
144 } while (i > 0 && path->buf[i] != '/');
145 return i;
146}
147
148static void write_entry(const unsigned char *sha1, struct strbuf *path,
149 unsigned int mode, void *buffer, unsigned long size)
150{
151 struct ustar_header header;
152 struct strbuf ext_header;
153
154 memset(&header, 0, sizeof(header));
155 ext_header.buf = NULL;
156 ext_header.len = ext_header.alloc = 0;
157
158 if (!sha1) {
159 *header.typeflag = TYPEFLAG_GLOBAL_HEADER;
160 mode = 0100666;
161 strcpy(header.name, "pax_global_header");
162 } else if (!path) {
163 *header.typeflag = TYPEFLAG_EXT_HEADER;
164 mode = 0100666;
165 sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
166 } else {
167 if (verbose)
168 fprintf(stderr, "%.*s\n", path->len, path->buf);
02851e0b 169 if (S_ISDIR(mode) || S_ISDIRLNK(mode)) {
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170 *header.typeflag = TYPEFLAG_DIR;
171 mode = (mode | 0777) & ~tar_umask;
172 } else if (S_ISLNK(mode)) {
173 *header.typeflag = TYPEFLAG_LNK;
174 mode |= 0777;
175 } else if (S_ISREG(mode)) {
176 *header.typeflag = TYPEFLAG_REG;
177 mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
178 } else {
179 error("unsupported file mode: 0%o (SHA1: %s)",
180 mode, sha1_to_hex(sha1));
181 return;
182 }
183 if (path->len > sizeof(header.name)) {
184 int plen = get_path_prefix(path, sizeof(header.prefix));
185 int rest = path->len - plen - 1;
186 if (plen > 0 && rest <= sizeof(header.name)) {
187 memcpy(header.prefix, path->buf, plen);
188 memcpy(header.name, path->buf + plen + 1, rest);
189 } else {
190 sprintf(header.name, "%s.data",
191 sha1_to_hex(sha1));
192 strbuf_append_ext_header(&ext_header, "path",
193 path->buf, path->len);
194 }
195 } else
196 memcpy(header.name, path->buf, path->len);
197 }
198
199 if (S_ISLNK(mode) && buffer) {
200 if (size > sizeof(header.linkname)) {
201 sprintf(header.linkname, "see %s.paxheader",
202 sha1_to_hex(sha1));
203 strbuf_append_ext_header(&ext_header, "linkpath",
204 buffer, size);
205 } else
206 memcpy(header.linkname, buffer, size);
207 }
208
209 sprintf(header.mode, "%07o", mode & 07777);
210 sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
211 sprintf(header.mtime, "%011lo", archive_time);
212
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213 sprintf(header.uid, "%07o", 0);
214 sprintf(header.gid, "%07o", 0);
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215 strlcpy(header.uname, "root", sizeof(header.uname));
216 strlcpy(header.gname, "root", sizeof(header.gname));
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217 sprintf(header.devmajor, "%07o", 0);
218 sprintf(header.devminor, "%07o", 0);
219
220 memcpy(header.magic, "ustar", 6);
221 memcpy(header.version, "00", 2);
222
223 sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
224
225 if (ext_header.len > 0) {
226 write_entry(sha1, NULL, 0, ext_header.buf, ext_header.len);
227 free(ext_header.buf);
228 }
229 write_blocked(&header, sizeof(header));
230 if (S_ISREG(mode) && buffer && size > 0)
231 write_blocked(buffer, size);
232}
233
234static void write_global_extended_header(const unsigned char *sha1)
235{
236 struct strbuf ext_header;
237 ext_header.buf = NULL;
238 ext_header.len = ext_header.alloc = 0;
239 strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
240 write_entry(NULL, NULL, 0, ext_header.buf, ext_header.len);
241 free(ext_header.buf);
242}
243
244static int git_tar_config(const char *var, const char *value)
245{
246 if (!strcmp(var, "tar.umask")) {
247 if (!strcmp(value, "user")) {
248 tar_umask = umask(0);
249 umask(tar_umask);
250 } else {
251 tar_umask = git_config_int(var, value);
252 }
253 return 0;
254 }
255 return git_default_config(var, value);
256}
257
258static int write_tar_entry(const unsigned char *sha1,
259 const char *base, int baselen,
260 const char *filename, unsigned mode, int stage)
261{
262 static struct strbuf path;
263 int filenamelen = strlen(filename);
264 void *buffer;
21666f1a 265 enum object_type type;
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266 unsigned long size;
267
268 if (!path.alloc) {
269 path.buf = xmalloc(PATH_MAX);
270 path.alloc = PATH_MAX;
271 path.len = path.eof = 0;
272 }
273 if (path.alloc < baselen + filenamelen) {
274 free(path.buf);
275 path.buf = xmalloc(baselen + filenamelen);
276 path.alloc = baselen + filenamelen;
277 }
278 memcpy(path.buf, base, baselen);
279 memcpy(path.buf + baselen, filename, filenamelen);
280 path.len = baselen + filenamelen;
02851e0b 281 if (S_ISDIR(mode) || S_ISDIRLNK(mode)) {
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282 strbuf_append_string(&path, "/");
283 buffer = NULL;
284 size = 0;
285 } else {
21666f1a 286 buffer = read_sha1_file(sha1, &type, &size);
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287 if (!buffer)
288 die("cannot read %s", sha1_to_hex(sha1));
289 }
290
291 write_entry(sha1, &path, mode, buffer, size);
292 free(buffer);
293
294 return READ_TREE_RECURSIVE;
295}
296
297int write_tar_archive(struct archiver_args *args)
298{
299 int plen = args->base ? strlen(args->base) : 0;
300
301 git_config(git_tar_config);
302
303 archive_time = args->time;
304 verbose = args->verbose;
305
306 if (args->commit_sha1)
307 write_global_extended_header(args->commit_sha1);
308
309 if (args->base && plen > 0 && args->base[plen - 1] == '/') {
310 char *base = xstrdup(args->base);
311 int baselen = strlen(base);
312
313 while (baselen > 0 && base[baselen - 1] == '/')
314 base[--baselen] = '\0';
315 write_tar_entry(args->tree->object.sha1, "", 0, base, 040777, 0);
316 free(base);
317 }
318 read_tree_recursive(args->tree, args->base, plen, 0,
319 args->pathspec, write_tar_entry);
320 write_trailer();
321
322 return 0;
323}