Code

Update jk/maint-strbuf-missing-init to builtin/ rename
[git.git] / path.c
diff --git a/path.c b/path.c
index 4b9107fed10c1f3551acf1f14d2ba5d1ba8a0b84..d1fccbde7f5ba08ba9876b12e1dbabf87f44b4e9 100644 (file)
--- a/path.c
+++ b/path.c
@@ -11,6 +11,7 @@
  * which is what it's designed for.
  */
 #include "cache.h"
+#include "strbuf.h"
 
 static char bad_path[] = "/bad-path/";
 
@@ -139,6 +140,22 @@ int git_mkstemp(char *path, size_t len, const char *template)
        return mkstemp(path);
 }
 
+/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
+int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
+{
+       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 mkstemps(path, suffix_len);
+}
 
 int validate_headref(const char *path)
 {
@@ -191,43 +208,49 @@ int validate_headref(const char *path)
        return -1;
 }
 
-static char *user_path(char *buf, char *path, int sz)
+static struct passwd *getpw_str(const char *username, size_t len)
 {
        struct passwd *pw;
-       char *slash;
-       int len, baselen;
+       char *username_z = xmalloc(len + 1);
+       memcpy(username_z, username, len);
+       username_z[len] = '\0';
+       pw = getpwnam(username_z);
+       free(username_z);
+       return pw;
+}
 
-       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 = '/';
+/*
+ * 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 *first_slash = strchrnul(path, '/');
+       const char *to_copy = path;
+
+       if (path == NULL)
+               goto return_null;
+       if (path[0] == '~') {
+               const char *username = path + 1;
+               size_t username_len = first_slash - username;
+               if (username_len == 0) {
+                       const char *home = getenv("HOME");
+                       strbuf_add(&user_path, home, strlen(home));
+               } else {
+                       struct passwd *pw = getpw_str(username, username_len);
+                       if (!pw)
+                               goto return_null;
+                       strbuf_add(&user_path, pw->pw_dir, strlen(pw->pw_dir));
                }
-               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);
+               to_copy = first_slash;
        }
-       return buf;
+       strbuf_add(&user_path, to_copy, strlen(to_copy));
+       return strbuf_detach(&user_path, NULL);
+return_null:
+       strbuf_release(&user_path);
+       return NULL;
 }
 
 /*
@@ -275,8 +298,18 @@ char *enter_repo(char *path, int strict)
                if (PATH_MAX <= len)
                        return NULL;
                if (path[0] == '~') {
-                       if (!user_path(used_path, path, PATH_MAX))
+                       char *newpath = expand_user_path(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);
                        strcpy(validated_path, path);
                        path = used_path;
                }
@@ -303,7 +336,7 @@ char *enter_repo(char *path, int strict)
 
        if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
            validate_headref("HEAD") == 0) {
-               setenv(GIT_DIR_ENVIRONMENT, ".", 1);
+               set_git_dir(".");
                check_repository_format();
                return path;
        }
@@ -311,36 +344,49 @@ char *enter_repo(char *path, int strict)
        return NULL;
 }
 
-int adjust_shared_perm(const char *path)
+int set_shared_perm(const char *path, int mode)
 {
        struct stat st;
-       int mode;
+       int tweak, shared, orig_mode;
 
-       if (!shared_repository)
+       if (!shared_repository) {
+               if (mode)
+                       return chmod(path, mode & ~S_IFMT);
                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 (!mode) {
+               if (lstat(path, &st) < 0)
+                       return -1;
+               mode = st.st_mode;
+               orig_mode = mode;
+       } else
+               orig_mode = 0;
+       if (shared_repository < 0)
+               shared = -shared_repository;
+       else
+               shared = shared_repository;
+       tweak = shared;
+
+       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;
 
        if (S_ISDIR(mode)) {
-               mode |= FORCE_DIR_SET_GID;
-
                /* Copy read bits to execute bits */
-               mode |= (shared_repository & 0444) >> 2;
+               mode |= (shared & 0444) >> 2;
+               mode |= FORCE_DIR_SET_GID;
        }
 
-       if ((mode & st.st_mode) != mode && chmod(path, mode) < 0)
+       if (((shared_repository < 0
+             ? (orig_mode & (FORCE_DIR_SET_GID | 0777))
+             : (orig_mode & mode)) != mode) &&
+           chmod(path, (mode & ~S_IFMT)) < 0)
                return -2;
        return 0;
 }
@@ -348,17 +394,38 @@ int adjust_shared_perm(const char *path)
 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))
+       int i = 0, j = 0;
+
+       if (!base || !base[0])
                return abs;
-       if (abs[baselen] == '/')
-               baselen++;
-       else if (base[baselen - 1] != '/')
+       while (base[i]) {
+               if (is_dir_sep(base[i])) {
+                       if (!is_dir_sep(abs[j]))
+                               return abs;
+                       while (is_dir_sep(base[i]))
+                               i++;
+                       while (is_dir_sep(abs[j]))
+                               j++;
+                       continue;
+               } else if (abs[j] != base[i]) {
+                       return abs;
+               }
+               i++;
+               j++;
+       }
+       if (
+           /* "/foo" is a prefix of "/foo" */
+           abs[j] &&
+           /* "/foo" is not a prefix of "/foobar" */
+           !is_dir_sep(base[i-1]) && !is_dir_sep(abs[j])
+          )
                return abs;
-       strcpy(buf, abs + baselen);
+       while (is_dir_sep(abs[j]))
+               j++;
+       if (!abs[j])
+               strcpy(buf, ".");
+       else
+               strcpy(buf, abs + j);
        return buf;
 }
 
@@ -499,3 +566,86 @@ int longest_ancestor_length(const char *path, const char *prefix_list)
 
        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;
+               }
+       }
+}