bus: rework sd_bus_error APIs

All calls that set a sd_bus_error structure will now return the same
error converted to a negative errno. This may be used as syntactic sugar
to return from a function and setting a bus_error structure in one go.

Also, translate all Linux Exyz (EIO, EINVAL, EUCLEAN, EPIPE, ...)
automatically into counterparts in the (new) "Posix.Error." namespace.

If we fail to allocate memory for the components of a sd_bus_error
automatically reset it to an OOM error which we always can write.

3 files changed, 90 insertions, 0 deletions

diff --git a/src/shared/.gitignore b/src/shared/.gitignore
new file mode 100644
index 0000000000..c9b5f81719
--- /dev/null
+++ b/src/shared/.gitignore
@@ -0,0 +1,4 @@
+/errno-from-name.gperf
+/errno-from-name.h
+/errno-list.txt
+/errno-to-name.h
diff --git a/src/shared/errno-list.c b/src/shared/errno-list.c
new file mode 100644
index 0000000000..c63296f292
--- /dev/null
+++ b/src/shared/errno-list.c
@@ -0,0 +1,59 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <string.h>
+
+#include "util.h"
+#include "errno-list.h"
+
+static const struct errno_name* lookup_errno(register const char *str,
+                                                 register unsigned int len);
+
+#include "errno-to-name.h"
+#include "errno-from-name.h"
+
+const char *errno_to_name(int id) {
+
+        if (id < 0)
+                id = -id;
+
+        if (id >= (int) ELEMENTSOF(errno_names))
+                return NULL;
+
+        return errno_names[id];
+}
+
+int errno_from_name(const char *name) {
+        const struct errno_name *sc;
+
+        assert(name);
+
+        sc = lookup_errno(name, strlen(name));
+        if (!sc)
+                return 0;
+
+        return sc->id;
+}
+
+int errno_max(void) {
+        return ELEMENTSOF(errno_names);
+}
diff --git a/src/shared/errno-list.h b/src/shared/errno-list.h
new file mode 100644
index 0000000000..ba533294e6
--- /dev/null
+++ b/src/shared/errno-list.h
@@ -0,0 +1,27 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+const char *errno_to_name(int id);
+int errno_from_name(const char *name);
+
+int errno_max(void);