1 files changed, 243 insertions, 0 deletions
diff --git a/src/lib-storage/list/mailbox-list-fs-flags.c b/src/lib-storage/list/mailbox-list-fs-flags.c
new file mode 100644
index 0000000..3f3bd94
--- /dev/null
+++ b/src/lib-storage/list/mailbox-list-fs-flags.c
@@ -0,0 +1,243 @@
+/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "mailbox-list-fs.h"
+
+#include <sys/stat.h>
+
+/* Assume that if atime < mtime, there are new mails. If it's good enough for
+   UW-IMAP, it's good enough for us. */
+#define STAT_GET_MARKED_FILE(st) \
+	((st).st_size == 0 ? MAILBOX_UNMARKED : \
+	 (st).st_atime < (st).st_mtime ? MAILBOX_MARKED : MAILBOX_UNMARKED)
+
+static int
+list_is_maildir_mailbox(struct mailbox_list *list, const char *dir,
+			const char *fname, enum mailbox_list_file_type type,
+			enum mailbox_info_flags *flags_r)
+{
+	const char *path, *maildir_path;
+	struct stat st, st2;
+	bool mailbox_files;
+
+	switch (type) {
+	case MAILBOX_LIST_FILE_TYPE_FILE:
+	case MAILBOX_LIST_FILE_TYPE_OTHER:
+		/* non-directories aren't valid */
+		*flags_r |= MAILBOX_NOSELECT | MAILBOX_NOINFERIORS;
+		return 0;
+
+	case MAILBOX_LIST_FILE_TYPE_DIR:
+	case MAILBOX_LIST_FILE_TYPE_UNKNOWN:
+	case MAILBOX_LIST_FILE_TYPE_SYMLINK:
+		break;
+	}
+
+	path = t_strdup_printf("%s/%s", dir, fname);
+	if (stat(path, &st) < 0) {
+		if (errno == ENOENT) {
+			*flags_r |= MAILBOX_NONEXISTENT;
+			return 0;
+		} else {
+			/* non-selectable. probably either access denied, or
+			   symlink destination not found. don't bother logging
+			   errors. */
+			*flags_r |= MAILBOX_NOSELECT;
+			return 1;
+		}
+	}
+	if (!S_ISDIR(st.st_mode)) {
+		if (str_begins(fname, ".nfs")) {
+			/* temporary NFS file */
+			*flags_r |= MAILBOX_NONEXISTENT;
+		} else {
+			*flags_r |= MAILBOX_NOSELECT | MAILBOX_NOINFERIORS;
+		}
+		return 0;
+	}
+
+	/* ok, we've got a directory. see what we can do about it. */
+
+	/* 1st link is "."
+	   2nd link is ".."
+	   3rd link is either child mailbox or mailbox dir
+	   rest of the links are child mailboxes
+
+	   if mailboxes are files, then 3+ links are all child mailboxes.
+	*/
+	mailbox_files = (list->flags & MAILBOX_LIST_FLAG_MAILBOX_FILES) != 0;
+	if (st.st_nlink == 2 && !mailbox_files) {
+		*flags_r |= MAILBOX_NOSELECT;
+		return 1;
+	}
+
+	/* we have at least one directory. see if this mailbox is selectable */
+	maildir_path = t_strconcat(path, "/", list->set.maildir_name, NULL);
+	if (stat(maildir_path, &st2) < 0)
+		*flags_r |= MAILBOX_NOSELECT | MAILBOX_CHILDREN;
+	else if (!S_ISDIR(st2.st_mode)) {
+		if (mailbox_files) {
+			*flags_r |= st.st_nlink == 2 ?
+				MAILBOX_NOCHILDREN : MAILBOX_CHILDREN;
+		} else {
+			*flags_r |= MAILBOX_NOSELECT | MAILBOX_CHILDREN;
+		}
+	} else {
+		/* now we know what link count 3 means. */
+		if (st.st_nlink == 3)
+			*flags_r |= MAILBOX_NOCHILDREN;
+		else
+			*flags_r |= MAILBOX_CHILDREN;
+	}
+	*flags_r |= MAILBOX_SELECT;
+	return 1;
+}
+
+static bool
+is_inbox_file(struct mailbox_list *list, const char *path, const char *fname)
+{
+	const char *inbox_path;
+
+	if (strcasecmp(fname, "INBOX") != 0)
+		return FALSE;
+
+	if (mailbox_list_get_path(list, "INBOX",
+				  MAILBOX_LIST_PATH_TYPE_MAILBOX,
+				  &inbox_path) <= 0)
+		i_unreached();
+	return strcmp(inbox_path, path) == 0;
+}
+
+int fs_list_get_mailbox_flags(struct mailbox_list *list,
+			      const char *dir, const char *fname,
+			      enum mailbox_list_file_type type,
+			      enum mailbox_info_flags *flags_r)
+{
+	struct stat st;
+	const char *path;
+
+	*flags_r = 0;
+
+	if (*list->set.maildir_name != '\0' && !list->set.iter_from_index_dir) {
+		/* maildir_name is set: This is the simple case that works for
+		   all mail storage formats, because the only thing that
+		   matters for existence or child checks is whether the
+		   maildir_name exists or not. For example with Maildir this
+		   doesn't care whether the "cur" directory exists; as long
+		   as the parent maildir_name exists, the Maildir is
+		   selectable. */
+		return list_is_maildir_mailbox(list, dir, fname, type, flags_r);
+	}
+	/* maildir_name is not set: Now we (may) need to use storage-specific
+	   code to determine whether the mailbox is selectable or if it has
+	   children.
+
+	   We're here also when iterating from index directory, because even
+	   though maildir_name is set, it's not used for index directory.
+	*/
+
+	if (!list->set.iter_from_index_dir &&
+	    list->v.is_internal_name != NULL &&
+	    list->v.is_internal_name(list, fname)) {
+		/* skip internal dirs. For example Maildir's cur/new/tmp */
+		*flags_r |= MAILBOX_NOSELECT;
+		return 0;
+	}
+
+	switch (type) {
+	case MAILBOX_LIST_FILE_TYPE_DIR:
+		/* We know that we're looking at a directory. If the storage
+		   uses files, it has to be a \NoSelect directory. */
+		if ((list->flags & MAILBOX_LIST_FLAG_MAILBOX_FILES) != 0) {
+			*flags_r |= MAILBOX_NOSELECT;
+			return 1;
+		}
+		break;
+	case MAILBOX_LIST_FILE_TYPE_FILE:
+		/* We know that we're looking at a file. If the storage
+		   doesn't use files, it's not a mailbox and we want to skip
+		   it. */
+		if ((list->flags & MAILBOX_LIST_FLAG_MAILBOX_FILES) == 0) {
+			*flags_r |= MAILBOX_NOSELECT | MAILBOX_NOINFERIORS;
+			return 0;
+		}
+		break;
+	default:
+		break;
+	}
+
+	/* we've done all filtering we can before stat()ing */
+	path = t_strconcat(dir, "/", fname, NULL);
+	if (stat(path, &st) < 0) {
+		if (ENOTFOUND(errno)) {
+			*flags_r |= MAILBOX_NONEXISTENT;
+			return 0;
+		} else if (ENOACCESS(errno)) {
+			*flags_r |= MAILBOX_NOSELECT;
+			return 1;
+		} else {
+			/* non-selectable. probably either access denied, or
+			   symlink destination not found. don't bother logging
+			   errors. */
+			mailbox_list_set_critical(list, "stat(%s) failed: %m",
+						  path);
+			return -1;
+		}
+	}
+
+	if (!S_ISDIR(st.st_mode)) {
+		if (str_begins(fname, ".nfs")) {
+			/* temporary NFS file */
+			*flags_r |= MAILBOX_NONEXISTENT;
+			return 0;
+		}
+
+		if ((list->flags & MAILBOX_LIST_FLAG_MAILBOX_FILES) == 0) {
+			*flags_r |= MAILBOX_NOSELECT | MAILBOX_NOINFERIORS;
+			return 0;
+		}
+		/* looks like a valid mailbox file */
+		if (is_inbox_file(list, path, fname) &&
+		    strcmp(fname, "INBOX") != 0) {
+			/* it's possible for INBOX to have child
+			   mailboxes as long as the inbox file itself
+			   isn't in <mail root>/INBOX */
+		} else {
+			*flags_r |= MAILBOX_NOINFERIORS;
+		}
+		/* Return mailbox files as always existing. The current
+		   mailbox_exists() code would do the same stat() anyway
+		   without further checks, so might as well avoid the second
+		   stat(). */
+		*flags_r |= MAILBOX_SELECT;
+		*flags_r |= STAT_GET_MARKED_FILE(st);
+		return 1;
+	}
+
+	/* This is a directory */
+	if ((list->flags & MAILBOX_LIST_FLAG_MAILBOX_FILES) != 0) {
+		/* We should get here only if type is
+		   MAILBOX_LIST_FILE_TYPE_UNKNOWN because the filesystem didn't
+		   return the type. Normally this should have already been
+		   handled by the MAILBOX_LIST_FILE_TYPE_DIR check above. */
+		*flags_r |= MAILBOX_NOSELECT;
+		return 1;
+	}
+
+	if (list->v.is_internal_name == NULL || list->set.iter_from_index_dir) {
+		/* This mailbox format doesn't use any special directories
+		   (e.g. Maildir's cur/new/tmp). In that case we can look at
+		   the directory's link count to determine whether there are
+		   children or not. The directory's link count equals the
+		   number of subdirectories it has. The first two links are
+		   for "." and "..".
+
+		   link count < 2 can happen with filesystems that don't
+		   support link counts. we'll just ignore them for now.. */
+		if (st.st_nlink == 2)
+			*flags_r |= MAILBOX_NOCHILDREN;
+		else if (st.st_nlink > 2)
+			*flags_r |= MAILBOX_CHILDREN;
+	}
+	return 1;
+}