git/wrapper.c
Matthieu Moy f80c7ae8fe Use git_mkstemp_mode and xmkstemp_mode in odb_mkstemp, not chmod later.
We used to create 0600 files, and then use chmod to set the group and
other permission bits to the umask. This usually has the same effect
as a normal file creation with a umask.

But in the presence of ACLs, the group permission plays the role of
the ACL mask: the "g" bits of newly created files are chosen according
to default ACL mask of the directory, not according to the umask, and
doing a chmod() on these "g" bits affect the ACL's mask instead of
actual group permission.

In other words, creating files with 0600 and then doing a chmod to the
umask creates files which are unreadable by users allowed in the
default ACL. To create the files without breaking ACLs, we let the
umask do it's job at the file's creation time, and get rid of the
later chmod.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-22 15:24:46 -08:00

329 lines
6.6 KiB
C

/*
* Various trivial helper wrappers around standard functions
*/
#include "cache.h"
char *xstrdup(const char *str)
{
char *ret = strdup(str);
if (!ret) {
release_pack_memory(strlen(str) + 1, -1);
ret = strdup(str);
if (!ret)
die("Out of memory, strdup failed");
}
return ret;
}
void *xmalloc(size_t size)
{
void *ret = malloc(size);
if (!ret && !size)
ret = malloc(1);
if (!ret) {
release_pack_memory(size, -1);
ret = malloc(size);
if (!ret && !size)
ret = malloc(1);
if (!ret)
die("Out of memory, malloc failed");
}
#ifdef XMALLOC_POISON
memset(ret, 0xA5, size);
#endif
return ret;
}
void *xmallocz(size_t size)
{
void *ret;
if (size + 1 < size)
die("Data too large to fit into virtual memory space.");
ret = xmalloc(size + 1);
((char*)ret)[size] = 0;
return ret;
}
/*
* xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
* "data" to the allocated memory, zero terminates the allocated memory,
* and returns a pointer to the allocated memory. If the allocation fails,
* the program dies.
*/
void *xmemdupz(const void *data, size_t len)
{
return memcpy(xmallocz(len), data, len);
}
char *xstrndup(const char *str, size_t len)
{
char *p = memchr(str, '\0', len);
return xmemdupz(str, p ? p - str : len);
}
void *xrealloc(void *ptr, size_t size)
{
void *ret = realloc(ptr, size);
if (!ret && !size)
ret = realloc(ptr, 1);
if (!ret) {
release_pack_memory(size, -1);
ret = realloc(ptr, size);
if (!ret && !size)
ret = realloc(ptr, 1);
if (!ret)
die("Out of memory, realloc failed");
}
return ret;
}
void *xcalloc(size_t nmemb, size_t size)
{
void *ret = calloc(nmemb, size);
if (!ret && (!nmemb || !size))
ret = calloc(1, 1);
if (!ret) {
release_pack_memory(nmemb * size, -1);
ret = calloc(nmemb, size);
if (!ret && (!nmemb || !size))
ret = calloc(1, 1);
if (!ret)
die("Out of memory, calloc failed");
}
return ret;
}
void *xmmap(void *start, size_t length,
int prot, int flags, int fd, off_t offset)
{
void *ret = mmap(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED) {
if (!length)
return NULL;
release_pack_memory(length, fd);
ret = mmap(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED)
die_errno("Out of memory? mmap failed");
}
return ret;
}
/*
* xread() is the same a read(), but it automatically restarts read()
* operations with a recoverable error (EAGAIN and EINTR). xread()
* DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
*/
ssize_t xread(int fd, void *buf, size_t len)
{
ssize_t nr;
while (1) {
nr = read(fd, buf, len);
if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
continue;
return nr;
}
}
/*
* xwrite() is the same a write(), but it automatically restarts write()
* operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
* GUARANTEE that "len" bytes is written even if the operation is successful.
*/
ssize_t xwrite(int fd, const void *buf, size_t len)
{
ssize_t nr;
while (1) {
nr = write(fd, buf, len);
if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
continue;
return nr;
}
}
ssize_t read_in_full(int fd, void *buf, size_t count)
{
char *p = buf;
ssize_t total = 0;
while (count > 0) {
ssize_t loaded = xread(fd, p, count);
if (loaded <= 0)
return total ? total : loaded;
count -= loaded;
p += loaded;
total += loaded;
}
return total;
}
ssize_t write_in_full(int fd, const void *buf, size_t count)
{
const char *p = buf;
ssize_t total = 0;
while (count > 0) {
ssize_t written = xwrite(fd, p, count);
if (written < 0)
return -1;
if (!written) {
errno = ENOSPC;
return -1;
}
count -= written;
p += written;
total += written;
}
return total;
}
int xdup(int fd)
{
int ret = dup(fd);
if (ret < 0)
die_errno("dup failed");
return ret;
}
FILE *xfdopen(int fd, const char *mode)
{
FILE *stream = fdopen(fd, mode);
if (stream == NULL)
die_errno("Out of memory? fdopen failed");
return stream;
}
int xmkstemp(char *template)
{
int fd;
fd = mkstemp(template);
if (fd < 0)
die_errno("Unable to create temporary file");
return fd;
}
int xmkstemp_mode(char *template, int mode)
{
int fd;
fd = git_mkstemp_mode(template, mode);
if (fd < 0)
die_errno("Unable to create temporary file");
return fd;
}
/*
* zlib wrappers to make sure we don't silently miss errors
* at init time.
*/
void git_inflate_init(z_streamp strm)
{
const char *err;
switch (inflateInit(strm)) {
case Z_OK:
return;
case Z_MEM_ERROR:
err = "out of memory";
break;
case Z_VERSION_ERROR:
err = "wrong version";
break;
default:
err = "error";
}
die("inflateInit: %s (%s)", err, strm->msg ? strm->msg : "no message");
}
void git_inflate_end(z_streamp strm)
{
if (inflateEnd(strm) != Z_OK)
error("inflateEnd: %s", strm->msg ? strm->msg : "failed");
}
int git_inflate(z_streamp strm, int flush)
{
int ret = inflate(strm, flush);
const char *err;
switch (ret) {
/* Out of memory is fatal. */
case Z_MEM_ERROR:
die("inflate: out of memory");
/* Data corruption errors: we may want to recover from them (fsck) */
case Z_NEED_DICT:
err = "needs dictionary"; break;
case Z_DATA_ERROR:
err = "data stream error"; break;
case Z_STREAM_ERROR:
err = "stream consistency error"; break;
default:
err = "unknown error"; break;
/* Z_BUF_ERROR: normal, needs more space in the output buffer */
case Z_BUF_ERROR:
case Z_OK:
case Z_STREAM_END:
return ret;
}
error("inflate: %s (%s)", err, strm->msg ? strm->msg : "no message");
return ret;
}
int odb_mkstemp(char *template, size_t limit, const char *pattern)
{
int fd;
/*
* we let the umask do its job, don't try to be more
* restrictive except to remove write permission.
*/
int mode = 0444;
snprintf(template, limit, "%s/%s",
get_object_directory(), pattern);
fd = git_mkstemp_mode(template, mode);
if (0 <= fd)
return fd;
/* slow path */
/* some mkstemp implementations erase template on failure */
snprintf(template, limit, "%s/%s",
get_object_directory(), pattern);
safe_create_leading_directories(template);
return xmkstemp_mode(template, mode);
}
int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1)
{
int fd;
snprintf(name, namesz, "%s/pack/pack-%s.keep",
get_object_directory(), sha1_to_hex(sha1));
fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
if (0 <= fd)
return fd;
/* slow path */
safe_create_leading_directories(name);
return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
}
int unlink_or_warn(const char *file)
{
int rc = unlink(file);
if (rc < 0) {
int err = errno;
if (ENOENT != err) {
warning("unable to unlink %s: %s",
file, strerror(errno));
errno = err;
}
}
return rc;
}