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Diffstat (limited to 'src/libsystemd-network/dhcp-identifier.c')
-rw-r--r--src/libsystemd-network/dhcp-identifier.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/src/libsystemd-network/dhcp-identifier.c b/src/libsystemd-network/dhcp-identifier.c
new file mode 100644
index 0000000000..1d9ec7be82
--- /dev/null
+++ b/src/libsystemd-network/dhcp-identifier.c
@@ -0,0 +1,98 @@
+/***
+ This file is part of systemd.
+
+ Copyright (C) 2015 Tom Gundersen <teg@jklmen>
+
+ 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 "libudev.h"
+#include "sd-id128.h"
+
+#include "dhcp-identifier.h"
+#include "dhcp6-protocol.h"
+#include "network-internal.h"
+#include "siphash24.h"
+#include "sparse-endian.h"
+#include "udev-util.h"
+#include "virt.h"
+
+#define SYSTEMD_PEN 43793
+#define HASH_KEY SD_ID128_MAKE(80,11,8c,c2,fe,4a,03,ee,3e,d6,0c,6f,36,39,14,09)
+
+int dhcp_identifier_set_duid_en(struct duid *duid, size_t *len) {
+ sd_id128_t machine_id;
+ uint64_t hash;
+ int r;
+
+ assert(duid);
+ assert(len);
+
+ r = sd_id128_get_machine(&machine_id);
+ if (r < 0)
+ return r;
+
+ unaligned_write_be16(&duid->type, DHCP6_DUID_EN);
+ unaligned_write_be32(&duid->en.pen, SYSTEMD_PEN);
+
+ *len = sizeof(duid->type) + sizeof(duid->en);
+
+ /* a bit of snake-oil perhaps, but no need to expose the machine-id
+ directly; duid->en.id might not be aligned, so we need to copy */
+ hash = htole64(siphash24(&machine_id, sizeof(machine_id), HASH_KEY.bytes));
+ memcpy(duid->en.id, &hash, sizeof(duid->en.id));
+
+ return 0;
+}
+
+int dhcp_identifier_set_iaid(int ifindex, uint8_t *mac, size_t mac_len, void *_id) {
+ /* name is a pointer to memory in the udev_device struct, so must
+ have the same scope */
+ _cleanup_udev_device_unref_ struct udev_device *device = NULL;
+ const char *name = NULL;
+ uint64_t id;
+
+ if (detect_container() <= 0) {
+ /* not in a container, udev will be around */
+ _cleanup_udev_unref_ struct udev *udev;
+ char ifindex_str[2 + DECIMAL_STR_MAX(int)];
+
+ udev = udev_new();
+ if (!udev)
+ return -ENOMEM;
+
+ sprintf(ifindex_str, "n%d", ifindex);
+ device = udev_device_new_from_device_id(udev, ifindex_str);
+ if (device) {
+ if (udev_device_get_is_initialized(device) <= 0)
+ /* not yet ready */
+ return -EBUSY;
+
+ name = net_get_name(device);
+ }
+ }
+
+ if (name)
+ id = siphash24(name, strlen(name), HASH_KEY.bytes);
+ else
+ /* fall back to MAC address if no predictable name available */
+ id = siphash24(mac, mac_len, HASH_KEY.bytes);
+
+ id = htole64(id);
+
+ /* fold into 32 bits */
+ unaligned_write_be32(_id, (id & 0xffffffff) ^ (id >> 32));
+
+ return 0;
+}