[systemd-devel] [PATCH] udev: Add hidraw_id and a rule file to invoke it
Andy Lutomirski
luto at amacapital.net
Tue Oct 28 15:46:16 PDT 2014
So far, hidraw_id detects U2F tokens and sets:
ID_U2F_TOKEN=1
ID_SECURITY_TOKEN=1
This causes the uaccess rules to apply to U2F devices.
---
I've never written any udev code before. Feedback welcome.
If you think this doesn't belong in udev, I can try to find it another home.
.gitignore | 1 +
Makefile.am | 11 ++++
rules/60-hidraw.rules | 7 ++
src/udev/hidraw_id/Makefile | 1 +
src/udev/hidraw_id/hidraw_id.c | 144 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 164 insertions(+)
create mode 100644 rules/60-hidraw.rules
create mode 120000 src/udev/hidraw_id/Makefile
create mode 100644 src/udev/hidraw_id/hidraw_id.c
diff --git a/.gitignore b/.gitignore
index f119b574c777..4bd3cdf08f0d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -34,6 +34,7 @@
/exported
/exported-*
/gtk-doc.make
+/hidraw_id
/hostnamectl
/install-tree
/journalctl
diff --git a/Makefile.am b/Makefile.am
index fae946a388af..9f64687d32b1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3542,6 +3542,17 @@ udevlibexec_PROGRAMS += \
ata_id
# ------------------------------------------------------------------------------
+hidraw_id_SOURCES = \
+ src/udev/hidraw_id/hidraw_id.c
+
+hidraw_id_LDADD = \
+ libudev-internal.la \
+ libsystemd-shared.la
+
+udevlibexec_PROGRAMS += \
+ hidraw_id
+
+# ------------------------------------------------------------------------------
cdrom_id_SOURCES = \
src/udev/cdrom_id/cdrom_id.c
diff --git a/rules/60-hidraw.rules b/rules/60-hidraw.rules
new file mode 100644
index 000000000000..1ee9c812f711
--- /dev/null
+++ b/rules/60-hidraw.rules
@@ -0,0 +1,7 @@
+# do not edit this file, it will be overwritten on update
+
+ACTION=="remove", GOTO="hidraw_end"
+
+SUBSYSTEM=="hidraw", IMPORT{program}="hidraw_id --udev"
+
+LABEL="keyboard_end"
diff --git a/src/udev/hidraw_id/Makefile b/src/udev/hidraw_id/Makefile
new file mode 120000
index 000000000000..d0b0e8e0086f
--- /dev/null
+++ b/src/udev/hidraw_id/Makefile
@@ -0,0 +1 @@
+../Makefile
\ No newline at end of file
diff --git a/src/udev/hidraw_id/hidraw_id.c b/src/udev/hidraw_id/hidraw_id.c
new file mode 100644
index 000000000000..e32f222f22f9
--- /dev/null
+++ b/src/udev/hidraw_id/hidraw_id.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) Andrew Lutomirski, 2014
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "libudev.h"
+#include "libudev-private.h"
+
+_printf_(6,0)
+static void log_fn(struct udev *udev, int priority,
+ const char *file, int line, const char *fn,
+ const char *format, va_list args)
+{
+ log_metav(priority, file, line, fn, format, args);
+}
+
+int main(int argc, char **argv)
+{
+ struct udev *udev;
+ struct udev_device *dev, *hiddev;
+ char path[4096];
+ unsigned char desc[4096];
+ int desclen;
+ int fd = -1;
+ int i;
+ int ret = 1;
+ unsigned int usage_page = 0;
+ int is_u2f_token = 0;
+
+ if (argc != 2) {
+ fprintf(stderr, "Usage: hidraw_id SYSFS_PATH|--udev\n");
+ return 1;
+ }
+
+ log_parse_environment();
+ log_open();
+
+ udev = udev_new();
+
+ udev_set_log_fn(udev, log_fn);
+
+ if (!strcmp(argv[1], "--udev"))
+ dev = udev_device_new_from_environment(udev);
+ else
+ dev = udev_device_new_from_syspath(udev, argv[1]);
+
+ if (!dev)
+ goto out;
+
+ hiddev = udev_device_get_parent(dev);
+ if (!hiddev)
+ goto out;
+
+ if (snprintf(path, sizeof(path), "%s/report_descriptor",
+ udev_device_get_syspath(hiddev)) > (int)sizeof(path))
+ return 1;
+
+ fd = open(path, O_RDONLY | O_NOFOLLOW);
+ if (fd == -1)
+ goto out;
+
+ desclen = read(fd, desc, sizeof(desc));
+ if (desclen <= 0)
+ goto out;
+
+ /* Parse the report descriptor. */
+ for (i = 0; i < desclen; ) {
+ unsigned char tag = desc[i] >> 4;
+ unsigned char type = (desc[i] >> 2) & 0x3;
+ unsigned char sizecode = desc[i] & 0x3;
+ int size, j;
+ unsigned int value = 0;
+
+ if (desc[i] == 0xfe) {
+ /* Long item; skip it. */
+ if (i + 1 >= desclen) {
+ log_error("bad report_descriptor");
+ goto out;
+ }
+ i += (desc[i+1] + 3); /* Can't overflow. */
+ continue;
+ }
+
+ size = (sizecode < 3 ? sizecode : 4);
+ if (i + 1 + size > desclen) {
+ log_error("bad report_descriptor");
+ goto out;
+ }
+
+ for (j = 0; j < size; j++)
+ value |= (desc[i + 1 + j] << 8*j);
+
+ if (type == 1 && tag == 0)
+ usage_page = value;
+
+ /*
+ * Detect U2F tokens. See:
+ * https://fidoalliance.org/specs/fido-u2f-HID-protocol-v1.0-rd-20141008.pdf
+ * http://www.usb.org/developers/hidpage/HUTRR48.pdf
+ */
+
+ if (type == 2 && tag == 0) {
+ if (usage_page == 0xf1d0 && value == 0x1)
+ is_u2f_token = 1;
+ }
+
+ i += 1 + size;
+ }
+
+ if (is_u2f_token)
+ printf("ID_U2F_TOKEN=1\nID_SECURITY_TOKEN=1\n");
+
+ ret = 0;
+
+out:
+ if (fd != -1)
+ close(fd);
+ if (dev)
+ udev_device_unref(dev);
+ udev_unref(udev);
+
+ log_close();
+
+ return ret;
+}
--
1.9.3
More information about the systemd-devel
mailing list