mirror of
https://github.com/git/git
synced 2024-08-24 18:26:02 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
This allows you to maintain a few filesystem pathnames concurrently, by simply replacing the single static "pathname" buffer with a LRU of four buffers. We did exactly the same thing with sha1_to_hex(), for pretty much exactly the same reason. Sometimes you want to use two pathnames, and while it's easy enough to xstrdup() them, why not just do the LU buffer thing. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
286 lines
6 KiB
C
286 lines
6 KiB
C
/*
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* I'm tired of doing "vsnprintf()" etc just to open a
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* file, so here's a "return static buffer with printf"
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* interface for paths.
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*
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* It's obviously not thread-safe. Sue me. But it's quite
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* useful for doing things like
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*
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* f = open(mkpath("%s/%s.git", base, name), O_RDONLY);
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*
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* which is what it's designed for.
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*/
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#include "cache.h"
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#include <pwd.h>
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static char bad_path[] = "/bad-path/";
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static char *get_pathname(void)
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{
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static char pathname_array[4][PATH_MAX];
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static int index;
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return pathname_array[3 & ++index];
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}
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static char *cleanup_path(char *path)
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{
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/* Clean it up */
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if (!memcmp(path, "./", 2)) {
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path += 2;
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while (*path == '/')
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path++;
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}
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return path;
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}
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char *mkpath(const char *fmt, ...)
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{
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va_list args;
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unsigned len;
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char *pathname = get_pathname();
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va_start(args, fmt);
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len = vsnprintf(pathname, PATH_MAX, fmt, args);
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va_end(args);
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if (len >= PATH_MAX)
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return bad_path;
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return cleanup_path(pathname);
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}
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char *git_path(const char *fmt, ...)
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{
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const char *git_dir = get_git_dir();
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char *pathname = get_pathname();
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va_list args;
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unsigned len;
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len = strlen(git_dir);
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if (len > PATH_MAX-100)
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return bad_path;
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memcpy(pathname, git_dir, len);
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if (len && git_dir[len-1] != '/')
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pathname[len++] = '/';
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va_start(args, fmt);
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len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
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va_end(args);
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if (len >= PATH_MAX)
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return bad_path;
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return cleanup_path(pathname);
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}
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/* git_mkstemp() - create tmp file honoring TMPDIR variable */
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int git_mkstemp(char *path, size_t len, const char *template)
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{
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char *env, *pch = path;
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if ((env = getenv("TMPDIR")) == NULL) {
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strcpy(pch, "/tmp/");
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len -= 5;
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pch += 5;
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} else {
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size_t n = snprintf(pch, len, "%s/", env);
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len -= n;
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pch += n;
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}
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strlcpy(pch, template, len);
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return mkstemp(path);
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}
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int validate_symref(const char *path)
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{
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struct stat st;
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char *buf, buffer[256];
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int len, fd;
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if (lstat(path, &st) < 0)
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return -1;
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/* Make sure it is a "refs/.." symlink */
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if (S_ISLNK(st.st_mode)) {
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len = readlink(path, buffer, sizeof(buffer)-1);
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if (len >= 5 && !memcmp("refs/", buffer, 5))
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return 0;
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return -1;
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}
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/*
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* Anything else, just open it and try to see if it is a symbolic ref.
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*/
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fd = open(path, O_RDONLY);
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if (fd < 0)
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return -1;
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len = read(fd, buffer, sizeof(buffer)-1);
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close(fd);
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/*
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* Is it a symbolic ref?
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*/
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if (len < 4 || memcmp("ref:", buffer, 4))
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return -1;
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buf = buffer + 4;
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len -= 4;
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while (len && isspace(*buf))
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buf++, len--;
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if (len >= 5 && !memcmp("refs/", buf, 5))
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return 0;
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return -1;
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}
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static char *user_path(char *buf, char *path, int sz)
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{
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struct passwd *pw;
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char *slash;
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int len, baselen;
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if (!path || path[0] != '~')
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return NULL;
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path++;
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slash = strchr(path, '/');
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if (path[0] == '/' || !path[0]) {
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pw = getpwuid(getuid());
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}
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else {
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if (slash) {
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*slash = 0;
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pw = getpwnam(path);
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*slash = '/';
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}
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else
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pw = getpwnam(path);
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}
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if (!pw || !pw->pw_dir || sz <= strlen(pw->pw_dir))
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return NULL;
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baselen = strlen(pw->pw_dir);
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memcpy(buf, pw->pw_dir, baselen);
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while ((1 < baselen) && (buf[baselen-1] == '/')) {
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buf[baselen-1] = 0;
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baselen--;
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}
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if (slash && slash[1]) {
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len = strlen(slash);
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if (sz <= baselen + len)
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return NULL;
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memcpy(buf + baselen, slash, len + 1);
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}
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return buf;
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}
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/*
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* First, one directory to try is determined by the following algorithm.
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*
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* (0) If "strict" is given, the path is used as given and no DWIM is
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* done. Otherwise:
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* (1) "~/path" to mean path under the running user's home directory;
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* (2) "~user/path" to mean path under named user's home directory;
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* (3) "relative/path" to mean cwd relative directory; or
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* (4) "/absolute/path" to mean absolute directory.
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*
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* Unless "strict" is given, we try access() for existence of "%s.git/.git",
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* "%s/.git", "%s.git", "%s" in this order. The first one that exists is
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* what we try.
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*
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* Second, we try chdir() to that. Upon failure, we return NULL.
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*
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* Then, we try if the current directory is a valid git repository.
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* Upon failure, we return NULL.
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*
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* If all goes well, we return the directory we used to chdir() (but
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* before ~user is expanded), avoiding getcwd() resolving symbolic
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* links. User relative paths are also returned as they are given,
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* except DWIM suffixing.
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*/
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char *enter_repo(char *path, int strict)
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{
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static char used_path[PATH_MAX];
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static char validated_path[PATH_MAX];
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if (!path)
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return NULL;
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if (!strict) {
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static const char *suffix[] = {
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".git/.git", "/.git", ".git", "", NULL,
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};
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int len = strlen(path);
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int i;
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while ((1 < len) && (path[len-1] == '/')) {
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path[len-1] = 0;
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len--;
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}
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if (PATH_MAX <= len)
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return NULL;
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if (path[0] == '~') {
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if (!user_path(used_path, path, PATH_MAX))
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return NULL;
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strcpy(validated_path, path);
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path = used_path;
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}
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else if (PATH_MAX - 10 < len)
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return NULL;
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else {
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path = strcpy(used_path, path);
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strcpy(validated_path, path);
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}
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len = strlen(path);
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for (i = 0; suffix[i]; i++) {
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strcpy(path + len, suffix[i]);
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if (!access(path, F_OK)) {
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strcat(validated_path, suffix[i]);
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break;
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}
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}
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if (!suffix[i] || chdir(path))
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return NULL;
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path = validated_path;
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}
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else if (chdir(path))
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return NULL;
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if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
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validate_symref("HEAD") == 0) {
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putenv("GIT_DIR=.");
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check_repository_format();
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return path;
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}
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return NULL;
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}
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int adjust_shared_perm(const char *path)
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{
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struct stat st;
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int mode;
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if (!shared_repository)
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return 0;
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if (lstat(path, &st) < 0)
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return -1;
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mode = st.st_mode;
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if (mode & S_IRUSR)
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mode |= (shared_repository == PERM_GROUP
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? S_IRGRP
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: (shared_repository == PERM_EVERYBODY
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? (S_IRGRP|S_IROTH)
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: 0));
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if (mode & S_IWUSR)
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mode |= S_IWGRP;
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if (mode & S_IXUSR)
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mode |= (shared_repository == PERM_GROUP
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? S_IXGRP
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: (shared_repository == PERM_EVERYBODY
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? (S_IXGRP|S_IXOTH)
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: 0));
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if (S_ISDIR(mode))
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mode |= S_ISGID;
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if (chmod(path, mode) < 0)
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return -2;
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return 0;
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}
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