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git/path.c
Petr Baudis 8c6202d869 Fix backwards-incompatible handling of core.sharedRepository
06cbe85 (Make core.sharedRepository more generic, 2008-04-16) broke the
traditional setting of core.sharedRepository to true, which was to make
the repository group writable: with umask 022, it would clear the
permission bits for 'other'. (umask 002 did not exhibit this behaviour
since pre-chmod() check in adjust_shared_perm() fails in that case.)

The call to adjust_shared_perm() should only loosen the permission.
If the user has umask like 022 or 002 that allow others to read, the
resulting files should be made readable and writable by group, without
restricting the readability by others.

This patch fixes the adjust_shared_perm() mode tweak based on Junio's
suggestion and adds the appropriate tests to t/t1301-shared-repo.sh.

Cc: Heikki Orsila <heikki.orsila@iki.fi>
Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-11 20:38:30 -07:00

412 lines
8.8 KiB
C

/*
* I'm tired of doing "vsnprintf()" etc just to open a
* file, so here's a "return static buffer with printf"
* interface for paths.
*
* It's obviously not thread-safe. Sue me. But it's quite
* useful for doing things like
*
* f = open(mkpath("%s/%s.git", base, name), O_RDONLY);
*
* which is what it's designed for.
*/
#include "cache.h"
static char bad_path[] = "/bad-path/";
static char *get_pathname(void)
{
static char pathname_array[4][PATH_MAX];
static int index;
return pathname_array[3 & ++index];
}
static char *cleanup_path(char *path)
{
/* Clean it up */
if (!memcmp(path, "./", 2)) {
path += 2;
while (*path == '/')
path++;
}
return path;
}
char *mkpath(const char *fmt, ...)
{
va_list args;
unsigned len;
char *pathname = get_pathname();
va_start(args, fmt);
len = vsnprintf(pathname, PATH_MAX, fmt, args);
va_end(args);
if (len >= PATH_MAX)
return bad_path;
return cleanup_path(pathname);
}
char *git_path(const char *fmt, ...)
{
const char *git_dir = get_git_dir();
char *pathname = get_pathname();
va_list args;
unsigned len;
len = strlen(git_dir);
if (len > PATH_MAX-100)
return bad_path;
memcpy(pathname, git_dir, len);
if (len && git_dir[len-1] != '/')
pathname[len++] = '/';
va_start(args, fmt);
len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
va_end(args);
if (len >= PATH_MAX)
return bad_path;
return cleanup_path(pathname);
}
/* git_mkstemp() - create tmp file honoring TMPDIR variable */
int git_mkstemp(char *path, size_t len, const char *template)
{
const char *tmp;
size_t n;
tmp = getenv("TMPDIR");
if (!tmp)
tmp = "/tmp";
n = snprintf(path, len, "%s/%s", tmp, template);
if (len <= n) {
errno = ENAMETOOLONG;
return -1;
}
return mkstemp(path);
}
int validate_headref(const char *path)
{
struct stat st;
char *buf, buffer[256];
unsigned char sha1[20];
int fd;
ssize_t len;
if (lstat(path, &st) < 0)
return -1;
/* Make sure it is a "refs/.." symlink */
if (S_ISLNK(st.st_mode)) {
len = readlink(path, buffer, sizeof(buffer)-1);
if (len >= 5 && !memcmp("refs/", buffer, 5))
return 0;
return -1;
}
/*
* Anything else, just open it and try to see if it is a symbolic ref.
*/
fd = open(path, O_RDONLY);
if (fd < 0)
return -1;
len = read_in_full(fd, buffer, sizeof(buffer)-1);
close(fd);
/*
* Is it a symbolic ref?
*/
if (len < 4)
return -1;
if (!memcmp("ref:", buffer, 4)) {
buf = buffer + 4;
len -= 4;
while (len && isspace(*buf))
buf++, len--;
if (len >= 5 && !memcmp("refs/", buf, 5))
return 0;
}
/*
* Is this a detached HEAD?
*/
if (!get_sha1_hex(buffer, sha1))
return 0;
return -1;
}
static char *user_path(char *buf, char *path, int sz)
{
struct passwd *pw;
char *slash;
int len, baselen;
if (!path || path[0] != '~')
return NULL;
path++;
slash = strchr(path, '/');
if (path[0] == '/' || !path[0]) {
pw = getpwuid(getuid());
}
else {
if (slash) {
*slash = 0;
pw = getpwnam(path);
*slash = '/';
}
else
pw = getpwnam(path);
}
if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir))
return NULL;
baselen = strlen(pw->pw_dir);
memcpy(buf, pw->pw_dir, baselen);
while ((1 < baselen) && (buf[baselen-1] == '/')) {
buf[baselen-1] = 0;
baselen--;
}
if (slash && slash[1]) {
len = strlen(slash);
if (sz <= baselen + len)
return NULL;
memcpy(buf + baselen, slash, len + 1);
}
return buf;
}
/*
* First, one directory to try is determined by the following algorithm.
*
* (0) If "strict" is given, the path is used as given and no DWIM is
* done. Otherwise:
* (1) "~/path" to mean path under the running user's home directory;
* (2) "~user/path" to mean path under named user's home directory;
* (3) "relative/path" to mean cwd relative directory; or
* (4) "/absolute/path" to mean absolute directory.
*
* Unless "strict" is given, we try access() for existence of "%s.git/.git",
* "%s/.git", "%s.git", "%s" in this order. The first one that exists is
* what we try.
*
* Second, we try chdir() to that. Upon failure, we return NULL.
*
* Then, we try if the current directory is a valid git repository.
* Upon failure, we return NULL.
*
* If all goes well, we return the directory we used to chdir() (but
* before ~user is expanded), avoiding getcwd() resolving symbolic
* links. User relative paths are also returned as they are given,
* except DWIM suffixing.
*/
char *enter_repo(char *path, int strict)
{
static char used_path[PATH_MAX];
static char validated_path[PATH_MAX];
if (!path)
return NULL;
if (!strict) {
static const char *suffix[] = {
".git/.git", "/.git", ".git", "", NULL,
};
int len = strlen(path);
int i;
while ((1 < len) && (path[len-1] == '/')) {
path[len-1] = 0;
len--;
}
if (PATH_MAX <= len)
return NULL;
if (path[0] == '~') {
if (!user_path(used_path, path, PATH_MAX))
return NULL;
strcpy(validated_path, path);
path = used_path;
}
else if (PATH_MAX - 10 < len)
return NULL;
else {
path = strcpy(used_path, path);
strcpy(validated_path, path);
}
len = strlen(path);
for (i = 0; suffix[i]; i++) {
strcpy(path + len, suffix[i]);
if (!access(path, F_OK)) {
strcat(validated_path, suffix[i]);
break;
}
}
if (!suffix[i] || chdir(path))
return NULL;
path = validated_path;
}
else if (chdir(path))
return NULL;
if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
validate_headref("HEAD") == 0) {
setenv(GIT_DIR_ENVIRONMENT, ".", 1);
check_repository_format();
return path;
}
return NULL;
}
int adjust_shared_perm(const char *path)
{
struct stat st;
int mode;
if (!shared_repository)
return 0;
if (lstat(path, &st) < 0)
return -1;
mode = st.st_mode;
if (shared_repository) {
int tweak = shared_repository;
if (!(mode & S_IWUSR))
tweak &= ~0222;
mode |= tweak;
} else {
/* Preserve old PERM_UMASK behaviour */
if (mode & S_IWUSR)
mode |= S_IWGRP;
}
if (S_ISDIR(mode)) {
mode |= FORCE_DIR_SET_GID;
/* Copy read bits to execute bits */
mode |= (shared_repository & 0444) >> 2;
}
if ((mode & st.st_mode) != mode && chmod(path, mode) < 0)
return -2;
return 0;
}
static const char *get_pwd_cwd(void)
{
static char cwd[PATH_MAX + 1];
char *pwd;
struct stat cwd_stat, pwd_stat;
if (getcwd(cwd, PATH_MAX) == NULL)
return NULL;
pwd = getenv("PWD");
if (pwd && strcmp(pwd, cwd)) {
stat(cwd, &cwd_stat);
if (!stat(pwd, &pwd_stat) &&
pwd_stat.st_dev == cwd_stat.st_dev &&
pwd_stat.st_ino == cwd_stat.st_ino) {
strlcpy(cwd, pwd, PATH_MAX);
}
}
return cwd;
}
const char *make_nonrelative_path(const char *path)
{
static char buf[PATH_MAX + 1];
if (is_absolute_path(path)) {
if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
die ("Too long path: %.*s", 60, path);
} else {
const char *cwd = get_pwd_cwd();
if (!cwd)
die("Cannot determine the current working directory");
if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
die ("Too long path: %.*s", 60, path);
}
return buf;
}
/* We allow "recursive" symbolic links. Only within reason, though. */
#define MAXDEPTH 5
const char *make_relative_path(const char *abs, const char *base)
{
static char buf[PATH_MAX + 1];
int baselen;
if (!base)
return abs;
baselen = strlen(base);
if (prefixcmp(abs, base))
return abs;
if (abs[baselen] == '/')
baselen++;
else if (base[baselen - 1] != '/')
return abs;
strcpy(buf, abs + baselen);
return buf;
}
const char *make_absolute_path(const char *path)
{
static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
char cwd[1024] = "";
int buf_index = 1, len;
int depth = MAXDEPTH;
char *last_elem = NULL;
struct stat st;
if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
die ("Too long path: %.*s", 60, path);
while (depth--) {
if (stat(buf, &st) || !S_ISDIR(st.st_mode)) {
char *last_slash = strrchr(buf, '/');
if (last_slash) {
*last_slash = '\0';
last_elem = xstrdup(last_slash + 1);
} else {
last_elem = xstrdup(buf);
*buf = '\0';
}
}
if (*buf) {
if (!*cwd && !getcwd(cwd, sizeof(cwd)))
die ("Could not get current working directory");
if (chdir(buf))
die ("Could not switch to '%s'", buf);
}
if (!getcwd(buf, PATH_MAX))
die ("Could not get current working directory");
if (last_elem) {
int len = strlen(buf);
if (len + strlen(last_elem) + 2 > PATH_MAX)
die ("Too long path name: '%s/%s'",
buf, last_elem);
buf[len] = '/';
strcpy(buf + len + 1, last_elem);
free(last_elem);
last_elem = NULL;
}
if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
len = readlink(buf, next_buf, PATH_MAX);
if (len < 0)
die ("Invalid symlink: %s", buf);
next_buf[len] = '\0';
buf = next_buf;
buf_index = 1 - buf_index;
next_buf = bufs[buf_index];
} else
break;
}
if (*cwd && chdir(cwd))
die ("Could not change back to '%s'", cwd);
return buf;
}