git/path.c
Junio C Hamano 77933f4449 Sync with v2.1.4
* maint-2.1:
  Git 2.1.4
  Git 2.0.5
  Git 1.9.5
  Git 1.8.5.6
  fsck: complain about NTFS ".git" aliases in trees
  read-cache: optionally disallow NTFS .git variants
  path: add is_ntfs_dotgit() helper
  fsck: complain about HFS+ ".git" aliases in trees
  read-cache: optionally disallow HFS+ .git variants
  utf8: add is_hfs_dotgit() helper
  fsck: notice .git case-insensitively
  t1450: refactor ".", "..", and ".git" fsck tests
  verify_dotfile(): reject .git case-insensitively
  read-tree: add tests for confusing paths like ".." and ".git"
  unpack-trees: propagate errors adding entries to the index
2014-12-17 11:46:57 -08:00

859 lines
18 KiB
C

/*
* Utilities for paths and pathnames
*/
#include "cache.h"
#include "strbuf.h"
#include "string-list.h"
static int get_st_mode_bits(const char *path, int *mode)
{
struct stat st;
if (lstat(path, &st) < 0)
return -1;
*mode = st.st_mode;
return 0;
}
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 *mksnpath(char *buf, size_t n, const char *fmt, ...)
{
va_list args;
unsigned len;
va_start(args, fmt);
len = vsnprintf(buf, n, fmt, args);
va_end(args);
if (len >= n) {
strlcpy(buf, bad_path, n);
return buf;
}
return cleanup_path(buf);
}
static char *vsnpath(char *buf, size_t n, const char *fmt, va_list args)
{
const char *git_dir = get_git_dir();
size_t len;
len = strlen(git_dir);
if (n < len + 1)
goto bad;
memcpy(buf, git_dir, len);
if (len && !is_dir_sep(git_dir[len-1]))
buf[len++] = '/';
len += vsnprintf(buf + len, n - len, fmt, args);
if (len >= n)
goto bad;
return cleanup_path(buf);
bad:
strlcpy(buf, bad_path, n);
return buf;
}
char *git_snpath(char *buf, size_t n, const char *fmt, ...)
{
char *ret;
va_list args;
va_start(args, fmt);
ret = vsnpath(buf, n, fmt, args);
va_end(args);
return ret;
}
char *git_pathdup(const char *fmt, ...)
{
char path[PATH_MAX], *ret;
va_list args;
va_start(args, fmt);
ret = vsnpath(path, sizeof(path), fmt, args);
va_end(args);
return xstrdup(ret);
}
char *mkpathdup(const char *fmt, ...)
{
char *path;
struct strbuf sb = STRBUF_INIT;
va_list args;
va_start(args, fmt);
strbuf_vaddf(&sb, fmt, args);
va_end(args);
path = xstrdup(cleanup_path(sb.buf));
strbuf_release(&sb);
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, ...)
{
char *pathname = get_pathname();
va_list args;
char *ret;
va_start(args, fmt);
ret = vsnpath(pathname, PATH_MAX, fmt, args);
va_end(args);
return ret;
}
void home_config_paths(char **global, char **xdg, char *file)
{
char *xdg_home = getenv("XDG_CONFIG_HOME");
char *home = getenv("HOME");
char *to_free = NULL;
if (!home) {
if (global)
*global = NULL;
} else {
if (!xdg_home) {
to_free = mkpathdup("%s/.config", home);
xdg_home = to_free;
}
if (global)
*global = mkpathdup("%s/.gitconfig", home);
}
if (xdg) {
if (!xdg_home)
*xdg = NULL;
else
*xdg = mkpathdup("%s/git/%s", xdg_home, file);
}
free(to_free);
}
char *git_path_submodule(const char *path, const char *fmt, ...)
{
char *pathname = get_pathname();
struct strbuf buf = STRBUF_INIT;
const char *git_dir;
va_list args;
unsigned len;
len = strlen(path);
if (len > PATH_MAX-100)
return bad_path;
strbuf_addstr(&buf, path);
if (len && path[len-1] != '/')
strbuf_addch(&buf, '/');
strbuf_addstr(&buf, ".git");
git_dir = read_gitfile(buf.buf);
if (git_dir) {
strbuf_reset(&buf);
strbuf_addstr(&buf, git_dir);
}
strbuf_addch(&buf, '/');
if (buf.len >= PATH_MAX)
return bad_path;
memcpy(pathname, buf.buf, buf.len + 1);
strbuf_release(&buf);
len = strlen(pathname);
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);
}
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 struct passwd *getpw_str(const char *username, size_t len)
{
struct passwd *pw;
char *username_z = xmemdupz(username, len);
pw = getpwnam(username_z);
free(username_z);
return pw;
}
/*
* Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
* then it is a newly allocated string. Returns NULL on getpw failure or
* if path is NULL.
*/
char *expand_user_path(const char *path)
{
struct strbuf user_path = STRBUF_INIT;
const char *to_copy = path;
if (path == NULL)
goto return_null;
if (path[0] == '~') {
const char *first_slash = strchrnul(path, '/');
const char *username = path + 1;
size_t username_len = first_slash - username;
if (username_len == 0) {
const char *home = getenv("HOME");
if (!home)
goto return_null;
strbuf_addstr(&user_path, home);
} else {
struct passwd *pw = getpw_str(username, username_len);
if (!pw)
goto return_null;
strbuf_addstr(&user_path, pw->pw_dir);
}
to_copy = first_slash;
}
strbuf_addstr(&user_path, to_copy);
return strbuf_detach(&user_path, NULL);
return_null:
strbuf_release(&user_path);
return NULL;
}
/*
* 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.
*/
const char *enter_repo(const 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,
};
const char *gitfile;
int len = strlen(path);
int i;
while ((1 < len) && (path[len-1] == '/'))
len--;
if (PATH_MAX <= len)
return NULL;
strncpy(used_path, path, len); used_path[len] = 0 ;
strcpy(validated_path, used_path);
if (used_path[0] == '~') {
char *newpath = expand_user_path(used_path);
if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
free(newpath);
return NULL;
}
/*
* Copy back into the static buffer. A pity
* since newpath was not bounded, but other
* branches of the if are limited by PATH_MAX
* anyway.
*/
strcpy(used_path, newpath); free(newpath);
}
else if (PATH_MAX - 10 < len)
return NULL;
len = strlen(used_path);
for (i = 0; suffix[i]; i++) {
struct stat st;
strcpy(used_path + len, suffix[i]);
if (!stat(used_path, &st) &&
(S_ISREG(st.st_mode) ||
(S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
strcat(validated_path, suffix[i]);
break;
}
}
if (!suffix[i])
return NULL;
gitfile = read_gitfile(used_path) ;
if (gitfile)
strcpy(used_path, gitfile);
if (chdir(used_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) {
set_git_dir(".");
check_repository_format();
return path;
}
return NULL;
}
static int calc_shared_perm(int mode)
{
int tweak;
if (shared_repository < 0)
tweak = -shared_repository;
else
tweak = shared_repository;
if (!(mode & S_IWUSR))
tweak &= ~0222;
if (mode & S_IXUSR)
/* Copy read bits to execute bits */
tweak |= (tweak & 0444) >> 2;
if (shared_repository < 0)
mode = (mode & ~0777) | tweak;
else
mode |= tweak;
return mode;
}
int adjust_shared_perm(const char *path)
{
int old_mode, new_mode;
if (!shared_repository)
return 0;
if (get_st_mode_bits(path, &old_mode) < 0)
return -1;
new_mode = calc_shared_perm(old_mode);
if (S_ISDIR(old_mode)) {
/* Copy read bits to execute bits */
new_mode |= (new_mode & 0444) >> 2;
new_mode |= FORCE_DIR_SET_GID;
}
if (((old_mode ^ new_mode) & ~S_IFMT) &&
chmod(path, (new_mode & ~S_IFMT)) < 0)
return -2;
return 0;
}
static int have_same_root(const char *path1, const char *path2)
{
int is_abs1, is_abs2;
is_abs1 = is_absolute_path(path1);
is_abs2 = is_absolute_path(path2);
return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
(!is_abs1 && !is_abs2);
}
/*
* Give path as relative to prefix.
*
* The strbuf may or may not be used, so do not assume it contains the
* returned path.
*/
const char *relative_path(const char *in, const char *prefix,
struct strbuf *sb)
{
int in_len = in ? strlen(in) : 0;
int prefix_len = prefix ? strlen(prefix) : 0;
int in_off = 0;
int prefix_off = 0;
int i = 0, j = 0;
if (!in_len)
return "./";
else if (!prefix_len)
return in;
if (have_same_root(in, prefix)) {
/* bypass dos_drive, for "c:" is identical to "C:" */
if (has_dos_drive_prefix(in)) {
i = 2;
j = 2;
}
} else {
return in;
}
while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
if (is_dir_sep(prefix[i])) {
while (is_dir_sep(prefix[i]))
i++;
while (is_dir_sep(in[j]))
j++;
prefix_off = i;
in_off = j;
} else {
i++;
j++;
}
}
if (
/* "prefix" seems like prefix of "in" */
i >= prefix_len &&
/*
* but "/foo" is not a prefix of "/foobar"
* (i.e. prefix not end with '/')
*/
prefix_off < prefix_len) {
if (j >= in_len) {
/* in="/a/b", prefix="/a/b" */
in_off = in_len;
} else if (is_dir_sep(in[j])) {
/* in="/a/b/c", prefix="/a/b" */
while (is_dir_sep(in[j]))
j++;
in_off = j;
} else {
/* in="/a/bbb/c", prefix="/a/b" */
i = prefix_off;
}
} else if (
/* "in" is short than "prefix" */
j >= in_len &&
/* "in" not end with '/' */
in_off < in_len) {
if (is_dir_sep(prefix[i])) {
/* in="/a/b", prefix="/a/b/c/" */
while (is_dir_sep(prefix[i]))
i++;
in_off = in_len;
}
}
in += in_off;
in_len -= in_off;
if (i >= prefix_len) {
if (!in_len)
return "./";
else
return in;
}
strbuf_reset(sb);
strbuf_grow(sb, in_len);
while (i < prefix_len) {
if (is_dir_sep(prefix[i])) {
strbuf_addstr(sb, "../");
while (is_dir_sep(prefix[i]))
i++;
continue;
}
i++;
}
if (!is_dir_sep(prefix[prefix_len - 1]))
strbuf_addstr(sb, "../");
strbuf_addstr(sb, in);
return sb->buf;
}
/*
* A simpler implementation of relative_path
*
* Get relative path by removing "prefix" from "in". This function
* first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
* to increase performance when traversing the path to work_tree.
*/
const char *remove_leading_path(const char *in, const char *prefix)
{
static char buf[PATH_MAX + 1];
int i = 0, j = 0;
if (!prefix || !prefix[0])
return in;
while (prefix[i]) {
if (is_dir_sep(prefix[i])) {
if (!is_dir_sep(in[j]))
return in;
while (is_dir_sep(prefix[i]))
i++;
while (is_dir_sep(in[j]))
j++;
continue;
} else if (in[j] != prefix[i]) {
return in;
}
i++;
j++;
}
if (
/* "/foo" is a prefix of "/foo" */
in[j] &&
/* "/foo" is not a prefix of "/foobar" */
!is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
)
return in;
while (is_dir_sep(in[j]))
j++;
if (!in[j])
strcpy(buf, ".");
else
strcpy(buf, in + j);
return buf;
}
/*
* It is okay if dst == src, but they should not overlap otherwise.
*
* Performs the following normalizations on src, storing the result in dst:
* - Ensures that components are separated by '/' (Windows only)
* - Squashes sequences of '/'.
* - Removes "." components.
* - Removes ".." components, and the components the precede them.
* Returns failure (non-zero) if a ".." component appears as first path
* component anytime during the normalization. Otherwise, returns success (0).
*
* Note that this function is purely textual. It does not follow symlinks,
* verify the existence of the path, or make any system calls.
*
* prefix_len != NULL is for a specific case of prefix_pathspec():
* assume that src == dst and src[0..prefix_len-1] is already
* normalized, any time "../" eats up to the prefix_len part,
* prefix_len is reduced. In the end prefix_len is the remaining
* prefix that has not been overridden by user pathspec.
*/
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
{
char *dst0;
if (has_dos_drive_prefix(src)) {
*dst++ = *src++;
*dst++ = *src++;
}
dst0 = dst;
if (is_dir_sep(*src)) {
*dst++ = '/';
while (is_dir_sep(*src))
src++;
}
for (;;) {
char c = *src;
/*
* A path component that begins with . could be
* special:
* (1) "." and ends -- ignore and terminate.
* (2) "./" -- ignore them, eat slash and continue.
* (3) ".." and ends -- strip one and terminate.
* (4) "../" -- strip one, eat slash and continue.
*/
if (c == '.') {
if (!src[1]) {
/* (1) */
src++;
} else if (is_dir_sep(src[1])) {
/* (2) */
src += 2;
while (is_dir_sep(*src))
src++;
continue;
} else if (src[1] == '.') {
if (!src[2]) {
/* (3) */
src += 2;
goto up_one;
} else if (is_dir_sep(src[2])) {
/* (4) */
src += 3;
while (is_dir_sep(*src))
src++;
goto up_one;
}
}
}
/* copy up to the next '/', and eat all '/' */
while ((c = *src++) != '\0' && !is_dir_sep(c))
*dst++ = c;
if (is_dir_sep(c)) {
*dst++ = '/';
while (is_dir_sep(c))
c = *src++;
src--;
} else if (!c)
break;
continue;
up_one:
/*
* dst0..dst is prefix portion, and dst[-1] is '/';
* go up one level.
*/
dst--; /* go to trailing '/' */
if (dst <= dst0)
return -1;
/* Windows: dst[-1] cannot be backslash anymore */
while (dst0 < dst && dst[-1] != '/')
dst--;
if (prefix_len && *prefix_len > dst - dst0)
*prefix_len = dst - dst0;
}
*dst = '\0';
return 0;
}
int normalize_path_copy(char *dst, const char *src)
{
return normalize_path_copy_len(dst, src, NULL);
}
/*
* path = Canonical absolute path
* prefixes = string_list containing normalized, absolute paths without
* trailing slashes (except for the root directory, which is denoted by "/").
*
* Determines, for each path in prefixes, whether the "prefix"
* is an ancestor directory of path. Returns the length of the longest
* ancestor directory, excluding any trailing slashes, or -1 if no prefix
* is an ancestor. (Note that this means 0 is returned if prefixes is
* ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
* are not considered to be their own ancestors. path must be in a
* canonical form: empty components, or "." or ".." components are not
* allowed.
*/
int longest_ancestor_length(const char *path, struct string_list *prefixes)
{
int i, max_len = -1;
if (!strcmp(path, "/"))
return -1;
for (i = 0; i < prefixes->nr; i++) {
const char *ceil = prefixes->items[i].string;
int len = strlen(ceil);
if (len == 1 && ceil[0] == '/')
len = 0; /* root matches anything, with length 0 */
else if (!strncmp(path, ceil, len) && path[len] == '/')
; /* match of length len */
else
continue; /* no match */
if (len > max_len)
max_len = len;
}
return max_len;
}
/* strip arbitrary amount of directory separators at end of path */
static inline int chomp_trailing_dir_sep(const char *path, int len)
{
while (len && is_dir_sep(path[len - 1]))
len--;
return len;
}
/*
* If path ends with suffix (complete path components), returns the
* part before suffix (sans trailing directory separators).
* Otherwise returns NULL.
*/
char *strip_path_suffix(const char *path, const char *suffix)
{
int path_len = strlen(path), suffix_len = strlen(suffix);
while (suffix_len) {
if (!path_len)
return NULL;
if (is_dir_sep(path[path_len - 1])) {
if (!is_dir_sep(suffix[suffix_len - 1]))
return NULL;
path_len = chomp_trailing_dir_sep(path, path_len);
suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
}
else if (path[--path_len] != suffix[--suffix_len])
return NULL;
}
if (path_len && !is_dir_sep(path[path_len - 1]))
return NULL;
return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
}
int daemon_avoid_alias(const char *p)
{
int sl, ndot;
/*
* This resurrects the belts and suspenders paranoia check by HPA
* done in <435560F7.4080006@zytor.com> thread, now enter_repo()
* does not do getcwd() based path canonicalization.
*
* sl becomes true immediately after seeing '/' and continues to
* be true as long as dots continue after that without intervening
* non-dot character.
*/
if (!p || (*p != '/' && *p != '~'))
return -1;
sl = 1; ndot = 0;
p++;
while (1) {
char ch = *p++;
if (sl) {
if (ch == '.')
ndot++;
else if (ch == '/') {
if (ndot < 3)
/* reject //, /./ and /../ */
return -1;
ndot = 0;
}
else if (ch == 0) {
if (0 < ndot && ndot < 3)
/* reject /.$ and /..$ */
return -1;
return 0;
}
else
sl = ndot = 0;
}
else if (ch == 0)
return 0;
else if (ch == '/') {
sl = 1;
ndot = 0;
}
}
}
static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
{
if (len < skip)
return 0;
len -= skip;
path += skip;
while (len-- > 0) {
char c = *(path++);
if (c != ' ' && c != '.')
return 0;
}
return 1;
}
int is_ntfs_dotgit(const char *name)
{
int len;
for (len = 0; ; len++)
if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
if (only_spaces_and_periods(name, len, 4) &&
!strncasecmp(name, ".git", 4))
return 1;
if (only_spaces_and_periods(name, len, 5) &&
!strncasecmp(name, "git~1", 5))
return 1;
if (name[len] != '\\')
return 0;
name += len + 1;
len = -1;
}
}