git/setup.c
Johannes Schindelin 3a3c3fc42a Fix crash when GIT_DIR is invalid
We used to test if a pointer was NULL, and if it was, try to access it.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-04 11:30:19 -07:00

265 lines
6.1 KiB
C

#include "cache.h"
const char *prefix_path(const char *prefix, int len, const char *path)
{
const char *orig = path;
for (;;) {
char c;
if (*path != '.')
break;
c = path[1];
/* "." */
if (!c) {
path++;
break;
}
/* "./" */
if (c == '/') {
path += 2;
continue;
}
if (c != '.')
break;
c = path[2];
if (!c)
path += 2;
else if (c == '/')
path += 3;
else
break;
/* ".." and "../" */
/* Remove last component of the prefix */
do {
if (!len)
die("'%s' is outside repository", orig);
len--;
} while (len && prefix[len-1] != '/');
continue;
}
if (len) {
int speclen = strlen(path);
char *n = xmalloc(speclen + len + 1);
memcpy(n, prefix, len);
memcpy(n + len, path, speclen+1);
path = n;
}
return path;
}
/*
* Unlike prefix_path, this should be used if the named file does
* not have to interact with index entry; i.e. name of a random file
* on the filesystem.
*/
const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
{
static char path[PATH_MAX];
if (!pfx || !*pfx || arg[0] == '/')
return arg;
memcpy(path, pfx, pfx_len);
strcpy(path + pfx_len, arg);
return path;
}
/*
* Verify a filename that we got as an argument for a pathspec
* entry. Note that a filename that begins with "-" never verifies
* as true, because even if such a filename were to exist, we want
* it to be preceded by the "--" marker (or we want the user to
* use a format like "./-filename")
*/
void verify_filename(const char *prefix, const char *arg)
{
const char *name;
struct stat st;
if (*arg == '-')
die("bad flag '%s' used after filename", arg);
name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
if (!lstat(name, &st))
return;
if (errno == ENOENT)
die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
"Use '--' to separate paths from revisions", arg);
die("'%s': %s", arg, strerror(errno));
}
/*
* Opposite of the above: the command line did not have -- marker
* and we parsed the arg as a refname. It should not be interpretable
* as a filename.
*/
void verify_non_filename(const char *prefix, const char *arg)
{
const char *name;
struct stat st;
if (*arg == '-')
return; /* flag */
name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
if (!lstat(name, &st))
die("ambiguous argument '%s': both revision and filename\n"
"Use '--' to separate filenames from revisions", arg);
if (errno != ENOENT)
die("'%s': %s", arg, strerror(errno));
}
const char **get_pathspec(const char *prefix, const char **pathspec)
{
const char *entry = *pathspec;
const char **p;
int prefixlen;
if (!prefix && !entry)
return NULL;
if (!entry) {
static const char *spec[2];
spec[0] = prefix;
spec[1] = NULL;
return spec;
}
/* Otherwise we have to re-write the entries.. */
p = pathspec;
prefixlen = prefix ? strlen(prefix) : 0;
do {
*p = prefix_path(prefix, prefixlen, entry);
} while ((entry = *++p) != NULL);
return (const char **) pathspec;
}
/*
* Test if it looks like we're at the top level git directory.
* We want to see:
*
* - either a .git/objects/ directory _or_ the proper
* GIT_OBJECT_DIRECTORY environment variable
* - a refs/ directory under ".git"
* - either a HEAD symlink or a HEAD file that is formatted as
* a proper "ref:".
*/
static int is_toplevel_directory(void)
{
if (access(".git/refs/", X_OK) ||
access(getenv(DB_ENVIRONMENT) ?
getenv(DB_ENVIRONMENT) : ".git/objects/", X_OK) ||
validate_symref(".git/HEAD"))
return 0;
return 1;
}
const char *setup_git_directory_gently(int *nongit_ok)
{
static char cwd[PATH_MAX+1];
int len, offset;
/*
* If GIT_DIR is set explicitly, we're not going
* to do any discovery, but we still do repository
* validation.
*/
if (getenv(GIT_DIR_ENVIRONMENT)) {
char path[PATH_MAX];
int len = strlen(getenv(GIT_DIR_ENVIRONMENT));
if (sizeof(path) - 40 < len)
die("'$%s' too big", GIT_DIR_ENVIRONMENT);
memcpy(path, getenv(GIT_DIR_ENVIRONMENT), len);
strcpy(path + len, "/refs");
if (access(path, X_OK))
goto bad_dir_environ;
strcpy(path + len, "/HEAD");
if (validate_symref(path))
goto bad_dir_environ;
if (getenv(DB_ENVIRONMENT)) {
if (access(getenv(DB_ENVIRONMENT), X_OK))
goto bad_dir_environ;
}
else {
strcpy(path + len, "/objects");
if (access(path, X_OK))
goto bad_dir_environ;
}
return NULL;
bad_dir_environ:
if (nongit_ok) {
*nongit_ok = 1;
return NULL;
}
path[len] = 0;
die("Not a git repository: '%s'", path);
}
if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
die("Unable to read current working directory");
offset = len = strlen(cwd);
for (;;) {
if (is_toplevel_directory())
break;
chdir("..");
do {
if (!offset) {
if (nongit_ok) {
if (chdir(cwd))
die("Cannot come back to cwd");
*nongit_ok = 1;
return NULL;
}
die("Not a git repository");
}
} while (cwd[--offset] != '/');
}
if (offset == len)
return NULL;
/* Make "offset" point to past the '/', and add a '/' at the end */
offset++;
cwd[len++] = '/';
cwd[len] = 0;
return cwd + offset;
}
int git_config_perm(const char *var, const char *value)
{
if (value) {
if (!strcmp(value, "umask"))
return PERM_UMASK;
if (!strcmp(value, "group"))
return PERM_GROUP;
if (!strcmp(value, "all") ||
!strcmp(value, "world") ||
!strcmp(value, "everybody"))
return PERM_EVERYBODY;
}
return git_config_bool(var, value);
}
int check_repository_format_version(const char *var, const char *value)
{
if (strcmp(var, "core.repositoryformatversion") == 0)
repository_format_version = git_config_int(var, value);
else if (strcmp(var, "core.sharedrepository") == 0)
shared_repository = git_config_perm(var, value);
return 0;
}
int check_repository_format(void)
{
git_config(check_repository_format_version);
if (GIT_REPO_VERSION < repository_format_version)
die ("Expected git repo version <= %d, found %d",
GIT_REPO_VERSION, repository_format_version);
return 0;
}
const char *setup_git_directory(void)
{
const char *retval = setup_git_directory_gently(NULL);
check_repository_format();
return retval;
}