xmkstemp(): avoid showing truncated template more carefully
[git/git.git] / wrapper.c
CommitLineData
112db553
LT
1/*
2 * Various trivial helper wrappers around standard functions
3 */
4#include "cache.h"
5
e0500293 6static void do_nothing(size_t size)
a9a74636 7{
a9a74636
NP
8}
9
e0500293 10static void (*try_to_free_routine)(size_t size) = do_nothing;
a9a74636 11
d41489a6
NTND
12static void memory_limit_check(size_t size)
13{
14 static int limit = -1;
15 if (limit == -1) {
16 const char *env = getenv("GIT_ALLOC_LIMIT");
17 limit = env ? atoi(env) * 1024 : 0;
18 }
19 if (limit && size > limit)
20 die("attempting to allocate %"PRIuMAX" over limit %d",
21 (intmax_t)size, limit);
22}
23
851c34b0 24try_to_free_t set_try_to_free_routine(try_to_free_t routine)
a9a74636 25{
851c34b0 26 try_to_free_t old = try_to_free_routine;
00b0d7f7
JH
27 if (!routine)
28 routine = do_nothing;
851c34b0
JS
29 try_to_free_routine = routine;
30 return old;
a9a74636
NP
31}
32
112db553
LT
33char *xstrdup(const char *str)
34{
35 char *ret = strdup(str);
36 if (!ret) {
a9a74636 37 try_to_free_routine(strlen(str) + 1);
112db553
LT
38 ret = strdup(str);
39 if (!ret)
40 die("Out of memory, strdup failed");
41 }
42 return ret;
43}
44
45void *xmalloc(size_t size)
46{
d41489a6
NTND
47 void *ret;
48
49 memory_limit_check(size);
50 ret = malloc(size);
112db553
LT
51 if (!ret && !size)
52 ret = malloc(1);
53 if (!ret) {
a9a74636 54 try_to_free_routine(size);
112db553
LT
55 ret = malloc(size);
56 if (!ret && !size)
57 ret = malloc(1);
58 if (!ret)
8bd9fd50
MM
59 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
60 (unsigned long)size);
112db553
LT
61 }
62#ifdef XMALLOC_POISON
63 memset(ret, 0xA5, size);
64#endif
65 return ret;
66}
67
5bf9219d
IL
68void *xmallocz(size_t size)
69{
70 void *ret;
1368f650 71 if (unsigned_add_overflows(size, 1))
5bf9219d
IL
72 die("Data too large to fit into virtual memory space.");
73 ret = xmalloc(size + 1);
74 ((char*)ret)[size] = 0;
75 return ret;
76}
77
112db553
LT
78/*
79 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
80 * "data" to the allocated memory, zero terminates the allocated memory,
81 * and returns a pointer to the allocated memory. If the allocation fails,
82 * the program dies.
83 */
84void *xmemdupz(const void *data, size_t len)
85{
5bf9219d 86 return memcpy(xmallocz(len), data, len);
112db553
LT
87}
88
89char *xstrndup(const char *str, size_t len)
90{
91 char *p = memchr(str, '\0', len);
92 return xmemdupz(str, p ? p - str : len);
93}
94
95void *xrealloc(void *ptr, size_t size)
96{
d41489a6
NTND
97 void *ret;
98
99 memory_limit_check(size);
100 ret = realloc(ptr, size);
112db553
LT
101 if (!ret && !size)
102 ret = realloc(ptr, 1);
103 if (!ret) {
a9a74636 104 try_to_free_routine(size);
112db553
LT
105 ret = realloc(ptr, size);
106 if (!ret && !size)
107 ret = realloc(ptr, 1);
108 if (!ret)
109 die("Out of memory, realloc failed");
110 }
111 return ret;
112}
113
114void *xcalloc(size_t nmemb, size_t size)
115{
d41489a6
NTND
116 void *ret;
117
118 memory_limit_check(size * nmemb);
119 ret = calloc(nmemb, size);
112db553
LT
120 if (!ret && (!nmemb || !size))
121 ret = calloc(1, 1);
122 if (!ret) {
a9a74636 123 try_to_free_routine(nmemb * size);
112db553
LT
124 ret = calloc(nmemb, size);
125 if (!ret && (!nmemb || !size))
126 ret = calloc(1, 1);
127 if (!ret)
128 die("Out of memory, calloc failed");
129 }
130 return ret;
131}
132
112db553
LT
133/*
134 * xread() is the same a read(), but it automatically restarts read()
135 * operations with a recoverable error (EAGAIN and EINTR). xread()
136 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
137 */
138ssize_t xread(int fd, void *buf, size_t len)
139{
140 ssize_t nr;
141 while (1) {
142 nr = read(fd, buf, len);
143 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
144 continue;
145 return nr;
146 }
147}
148
149/*
150 * xwrite() is the same a write(), but it automatically restarts write()
151 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
152 * GUARANTEE that "len" bytes is written even if the operation is successful.
153 */
154ssize_t xwrite(int fd, const void *buf, size_t len)
155{
156 ssize_t nr;
157 while (1) {
158 nr = write(fd, buf, len);
159 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
160 continue;
161 return nr;
162 }
163}
164
559e840b
JH
165ssize_t read_in_full(int fd, void *buf, size_t count)
166{
167 char *p = buf;
168 ssize_t total = 0;
169
170 while (count > 0) {
171 ssize_t loaded = xread(fd, p, count);
56d7c27a
JK
172 if (loaded < 0)
173 return -1;
174 if (loaded == 0)
175 return total;
559e840b
JH
176 count -= loaded;
177 p += loaded;
178 total += loaded;
179 }
180
181 return total;
182}
183
184ssize_t write_in_full(int fd, const void *buf, size_t count)
185{
186 const char *p = buf;
187 ssize_t total = 0;
188
189 while (count > 0) {
190 ssize_t written = xwrite(fd, p, count);
191 if (written < 0)
192 return -1;
193 if (!written) {
194 errno = ENOSPC;
195 return -1;
196 }
197 count -= written;
198 p += written;
199 total += written;
200 }
201
202 return total;
203}
204
112db553
LT
205int xdup(int fd)
206{
207 int ret = dup(fd);
208 if (ret < 0)
d824cbba 209 die_errno("dup failed");
112db553
LT
210 return ret;
211}
212
213FILE *xfdopen(int fd, const char *mode)
214{
215 FILE *stream = fdopen(fd, mode);
216 if (stream == NULL)
d824cbba 217 die_errno("Out of memory? fdopen failed");
112db553
LT
218 return stream;
219}
220
221int xmkstemp(char *template)
222{
223 int fd;
6cf6bb3e
AE
224 char origtemplate[PATH_MAX];
225 strlcpy(origtemplate, template, sizeof(origtemplate));
112db553
LT
226
227 fd = mkstemp(template);
6cf6bb3e
AE
228 if (fd < 0) {
229 int saved_errno = errno;
230 const char *nonrelative_template;
231
f7be59b4 232 if (strlen(template) != strlen(origtemplate))
6cf6bb3e
AE
233 template = origtemplate;
234
e2a57aac 235 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
236 errno = saved_errno;
237 die_errno("Unable to create temporary file '%s'",
238 nonrelative_template);
239 }
112db553
LT
240 return fd;
241}
39c68542 242
33f23936
JN
243/* git_mkstemp() - create tmp file honoring TMPDIR variable */
244int git_mkstemp(char *path, size_t len, const char *template)
245{
246 const char *tmp;
247 size_t n;
248
249 tmp = getenv("TMPDIR");
250 if (!tmp)
251 tmp = "/tmp";
252 n = snprintf(path, len, "%s/%s", tmp, template);
253 if (len <= n) {
254 errno = ENAMETOOLONG;
255 return -1;
256 }
257 return mkstemp(path);
258}
259
260/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
261int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
262{
263 const char *tmp;
264 size_t n;
265
266 tmp = getenv("TMPDIR");
267 if (!tmp)
268 tmp = "/tmp";
269 n = snprintf(path, len, "%s/%s", tmp, template);
270 if (len <= n) {
271 errno = ENAMETOOLONG;
272 return -1;
273 }
274 return mkstemps(path, suffix_len);
275}
276
277/* Adapted from libiberty's mkstemp.c. */
278
279#undef TMP_MAX
280#define TMP_MAX 16384
281
282int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
283{
284 static const char letters[] =
285 "abcdefghijklmnopqrstuvwxyz"
286 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
287 "0123456789";
288 static const int num_letters = 62;
289 uint64_t value;
290 struct timeval tv;
291 char *template;
292 size_t len;
293 int fd, count;
294
295 len = strlen(pattern);
296
297 if (len < 6 + suffix_len) {
298 errno = EINVAL;
299 return -1;
300 }
301
302 if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
303 errno = EINVAL;
304 return -1;
305 }
306
307 /*
308 * Replace pattern's XXXXXX characters with randomness.
309 * Try TMP_MAX different filenames.
310 */
311 gettimeofday(&tv, NULL);
312 value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
313 template = &pattern[len - 6 - suffix_len];
314 for (count = 0; count < TMP_MAX; ++count) {
315 uint64_t v = value;
316 /* Fill in the random bits. */
317 template[0] = letters[v % num_letters]; v /= num_letters;
318 template[1] = letters[v % num_letters]; v /= num_letters;
319 template[2] = letters[v % num_letters]; v /= num_letters;
320 template[3] = letters[v % num_letters]; v /= num_letters;
321 template[4] = letters[v % num_letters]; v /= num_letters;
322 template[5] = letters[v % num_letters]; v /= num_letters;
323
324 fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
325 if (fd > 0)
326 return fd;
327 /*
328 * Fatal error (EPERM, ENOSPC etc).
329 * It doesn't make sense to loop.
330 */
331 if (errno != EEXIST)
332 break;
333 /*
334 * This is a random value. It is only necessary that
335 * the next TMP_MAX values generated by adding 7777 to
336 * VALUE are different with (module 2^32).
337 */
338 value += 7777;
339 }
340 /* We return the null string if we can't find a unique file name. */
341 pattern[0] = '\0';
342 return -1;
343}
344
345int git_mkstemp_mode(char *pattern, int mode)
346{
347 /* mkstemp is just mkstemps with no suffix */
348 return git_mkstemps_mode(pattern, 0, mode);
349}
350
351int gitmkstemps(char *pattern, int suffix_len)
352{
353 return git_mkstemps_mode(pattern, suffix_len, 0600);
354}
355
b862b61c
MM
356int xmkstemp_mode(char *template, int mode)
357{
358 int fd;
6cf6bb3e
AE
359 char origtemplate[PATH_MAX];
360 strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c
MM
361
362 fd = git_mkstemp_mode(template, mode);
6cf6bb3e
AE
363 if (fd < 0) {
364 int saved_errno = errno;
365 const char *nonrelative_template;
366
367 if (!template[0])
368 template = origtemplate;
369
e2a57aac 370 nonrelative_template = absolute_path(template);
6cf6bb3e
AE
371 errno = saved_errno;
372 die_errno("Unable to create temporary file '%s'",
373 nonrelative_template);
374 }
b862b61c
MM
375 return fd;
376}
377
10e13ec8 378static int warn_if_unremovable(const char *op, const char *file, int rc)
fc71db39 379{
fc71db39
AR
380 if (rc < 0) {
381 int err = errno;
382 if (ENOENT != err) {
10e13ec8
PC
383 warning("unable to %s %s: %s",
384 op, file, strerror(errno));
fc71db39
AR
385 errno = err;
386 }
387 }
388 return rc;
389}
390
10e13ec8
PC
391int unlink_or_warn(const char *file)
392{
393 return warn_if_unremovable("unlink", file, unlink(file));
394}
d1723296
PC
395
396int rmdir_or_warn(const char *file)
397{
398 return warn_if_unremovable("rmdir", file, rmdir(file));
399}
80d706af
PC
400
401int remove_or_warn(unsigned int mode, const char *file)
402{
403 return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
404}
2f705875 405
55b38a48
JH
406void warn_on_inaccessible(const char *path)
407{
408 warning(_("unable to access '%s': %s"), path, strerror(errno));
409}
410
ba8bd830
JK
411int access_or_warn(const char *path, int mode)
412{
413 int ret = access(path, mode);
414 if (ret && errno != ENOENT)
55b38a48 415 warn_on_inaccessible(path);
ba8bd830
JK
416 return ret;
417}
418
2f705875
JK
419struct passwd *xgetpwuid_self(void)
420{
421 struct passwd *pw;
422
423 errno = 0;
424 pw = getpwuid(getuid());
425 if (!pw)
426 die(_("unable to look up current user in the passwd file: %s"),
427 errno ? strerror(errno) : _("no such user"));
428 return pw;
429}