/path.c
C | 823 lines | 586 code | 90 blank | 147 comment | 201 complexity | 4015d6a60e9b67345d92b32b9e6ff217 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.1, Apache-2.0, BSD-2-Clause
- /*
- * 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_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;
- }
- }
- }