device-nodes: move device node specific code to own file

In the process, rename udev_encode_string which is poorly named for what
it does. It deals specifically with encoding names that udev creates and
has its own rules: utf8 is valid but some ascii is not (e.g. path
separators), and everything else is simply escaped. Rename it to
encode_devnode_name.

1 files changed, 74 insertions, 0 deletions

diff --git a/src/shared/device-nodes.c b/src/shared/device-nodes.c
new file mode 100644
index 0000000000..986553e93f
--- /dev/null
+++ b/src/shared/device-nodes.c
@@ -0,0 +1,74 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 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 <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "device-nodes.h"
+#include "utf8.h"
+
+int whitelisted_char_for_devnode(char c, const char *white) {
+        if ((c >= '0' && c <= '9') ||
+            (c >= 'A' && c <= 'Z') ||
+            (c >= 'a' && c <= 'z') ||
+            strchr("#+-.:=@_", c) != NULL ||
+            (white != NULL && strchr(white, c) != NULL))
+                return 1;
+        return 0;
+}
+
+int encode_devnode_name(const char *str, char *str_enc, size_t len) {
+        size_t i, j;
+
+        if (str == NULL || str_enc == NULL)
+                return -1;
+
+        for (i = 0, j = 0; str[i] != '\0'; i++) {
+                int seqlen;
+
+                seqlen = utf8_encoded_valid_unichar(&str[i]);
+                if (seqlen > 1) {
+                        if (len-j < (size_t)seqlen)
+                                goto err;
+                        memcpy(&str_enc[j], &str[i], seqlen);
+                        j += seqlen;
+                        i += (seqlen-1);
+                } else if (str[i] == '\\' || !whitelisted_char_for_devnode(str[i], NULL)) {
+                        if (len-j < 4)
+                                goto err;
+                        sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]);
+                        j += 4;
+                } else {
+                        if (len-j < 1)
+                                goto err;
+                        str_enc[j] = str[i];
+                        j++;
+                }
+        }
+        if (len-j < 1)
+                goto err;
+        str_enc[j] = '\0';
+        return 0;
+err:
+        return -1;
+}