fs-posix: Added mode=auto parameter to copy mode from parent directory if setgid...

diff --git a/src/lib-fs/fs-posix.c b/src/lib-fs/fs-posix.c
index 0eca6e568368817ff18b520dcf650d524e757e0b..e7b48e3da2f8a990c810c7428dfc8dc1d4854e50 100644 (file)
--- a/src/lib-fs/fs-posix.c
+++ b/src/lib-fs/fs-posix.c
@@ -34,6 +34,7 @@ struct posix_fs {
        unsigned int temp_file_prefix_len;
        enum fs_posix_lock_method lock_method;
        mode_t mode;
+       bool mode_auto;
 };
 
 struct posix_fs_file {
@@ -102,6 +103,8 @@ fs_posix_init(struct fs *_fs, const char *args, const struct fs_settings *set)
                                fs->path_prefix = i_strconcat(arg + 7, "/", NULL);
                        else
                                fs->path_prefix = i_strdup(arg + 7);
+               } else if (strcmp(arg, "mode=auto") == 0) {
+                       fs->mode_auto = TRUE;
                } else if (strncmp(arg, "mode=", 5) == 0) {
                        unsigned int mode;
                        if (str_to_uint_oct(arg+5, &mode) < 0) {
@@ -140,21 +143,51 @@ static enum fs_properties fs_posix_get_properties(struct fs *fs ATTR_UNUSED)
                FS_PROPERTY_STAT | FS_PROPERTY_ITER | FS_PROPERTY_RELIABLEITER;
 }
 
+static int
+fs_posix_get_mode(struct posix_fs *fs, const char *path, mode_t *mode_r)
+{
+       struct stat st;
+       const char *p;
+
+       *mode_r = fs->mode;
+
+       while (stat(path, &st) < 0) {
+               if (errno != ENOENT) {
+                       fs_set_error(&fs->fs, "stat(%s) failed: %m", path);
+                       return -1;
+               }
+               p = strrchr(path, '/');
+               if (p != NULL)
+                       path = t_strdup_until(path, p);
+               else if (strcmp(path, ".") != 0)
+                       path = ".";
+               else
+                       return 0;
+       }
+       if ((st.st_mode & S_ISGID) != 0) {
+               /* setgid set - copy mode from parent */
+               *mode_r = st.st_mode & 0666;
+       }
+       return 0;
+}
+
 static int fs_posix_mkdir_parents(struct posix_fs *fs, const char *path)
 {
        const char *dir, *fname;
-       mode_t dir_mode;
+       mode_t mode, dir_mode;
 
        fname = strrchr(path, '/');
        if (fname == NULL)
                return 1;
+       dir = t_strdup_until(path, fname);
 
-       dir_mode = fs->mode;
+       if (fs_posix_get_mode(fs, dir, &mode) < 0)
+               return -1;
+       dir_mode = mode;
        if ((dir_mode & 0600) != 0) dir_mode |= 0100;
        if ((dir_mode & 0060) != 0) dir_mode |= 0010;
        if ((dir_mode & 0006) != 0) dir_mode |= 0001;
 
-       dir = t_strdup_until(path, fname);
        if (mkdir_parents(dir, dir_mode) == 0)
                return 0;
        else if (errno == EEXIST)
@@ -198,20 +231,28 @@ static int fs_posix_create(struct posix_fs_file *file)
        string_t *str = t_str_new(256);
        const char *slash;
        unsigned int try_count = 0;
+       mode_t mode;
        int fd;
 
        i_assert(file->temp_path == NULL);
 
-       if ((slash = strrchr(file->full_path, '/')) != NULL)
-               str_append_n(str, file->full_path, slash - file->full_path + 1);
+       if ((slash = strrchr(file->full_path, '/')) != NULL) {
+               str_append_n(str, file->full_path, slash - file->full_path);
+               if (fs_posix_get_mode(fs, str_c(str), &mode) < 0)
+                       return -1;
+               str_append_c(str, '/');
+       } else {
+               if (fs_posix_get_mode(fs, ".", &mode) < 0)
+                       return -1;
+       }
        str_append(str, fs->temp_file_prefix);
 
-       fd = safe_mkstemp_hostpid(str, fs->mode, (uid_t)-1, (gid_t)-1);
+       fd = safe_mkstemp_hostpid(str, mode, (uid_t)-1, (gid_t)-1);
        while (fd == -1 && errno == ENOENT &&
               try_count <= MAX_MKDIR_RETRY_COUNT) {
                if (fs_posix_mkdir_parents(fs, str_c(str)) < 0)
                        return -1;
-               fd = safe_mkstemp_hostpid(str, fs->mode, (uid_t)-1, (gid_t)-1);
+               fd = safe_mkstemp_hostpid(str, mode, (uid_t)-1, (gid_t)-1);
                try_count++;
        }
        if (fd == -1) {