network: dhcp - split out the duid structure into a new header file

We will use the same in both dhcp4 and dhcp6.

src/libsystemd-network/dhcp-identifier.h

@@ -0,0 +1,61 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  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 <net/ethernet.h>
+
+#include "sparse-endian.h"
+#include "sd-id128.h"
+
+/* RFC 3315 section 9.1:
+ *      A DUID can be no more than 128 octets long (not including the type code).
+ */
+#define MAX_DUID_LEN 128
+
+struct duid {
+        uint16_t type;
+        union {
+                struct {
+                        /* DHCP6_DUID_LLT */
+                        uint16_t htype;
+                        uint32_t time;
+                        uint8_t haddr[0];
+                } _packed_ llt;
+                struct {
+                        /* DHCP6_DUID_EN */
+                        uint32_t pen;
+                        uint8_t id[8];
+                } _packed_ en;
+                struct {
+                        /* DHCP6_DUID_LL */
+                        int16_t htype;
+                        uint8_t haddr[0];
+                } _packed_ ll;
+                struct {
+                        /* DHCP6_DUID_UUID */
+                        sd_id128_t uuid;
+                } _packed_ uuid;
+                struct {
+                        uint8_t data[MAX_DUID_LEN];
+                } _packed_ raw;
+        };
+} _packed_;

src/libsystemd-network/sd-dhcp6-client.c

@@ -36,15 +36,11 @@
 #include "dhcp6-protocol.h"
 #include "dhcp6-internal.h"
 #include "dhcp6-lease-internal.h"
+#include "dhcp-identifier.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)
 
-/* RFC 3315 section 9.1:
- *      A DUID can be no more than 128 octets long (not including the type code).
- */
-#define MAX_DUID_LEN 128
-
 #define MAX_MAC_ADDR_LEN INFINIBAND_ALEN
 
 struct sd_dhcp6_client {
@@ -73,32 +69,7 @@ struct sd_dhcp6_client {
         sd_event_source *timeout_resend_expire;
         sd_dhcp6_client_cb_t cb;
         void *userdata;
-        union {
+        struct duid duid;
-                struct {
-                        uint16_t type; /* DHCP6_DUID_LLT */
-                        uint16_t htype;
-                        uint32_t time;
-                        uint8_t haddr[0];
-                } _packed_ llt;
-                struct {
-                        uint16_t type; /* DHCP6_DUID_EN */
-                        uint32_t pen;
-                        uint8_t id[8];
-                } _packed_ en;
-                struct {
-                        uint16_t type; /* DHCP6_DUID_LL */
-                        uint16_t htype;
-                        uint8_t haddr[0];
-                } _packed_ ll;
-                struct {
-                        uint16_t type; /* DHCP6_DUID_UUID */
-                        sd_id128_t uuid;
-                } _packed_ uuid;
-                struct {
-                        uint16_t type;
-                        uint8_t data[MAX_DUID_LEN];
-                } _packed_ raw;
-        } duid;
         size_t duid_len;
 };
 
@@ -201,19 +172,19 @@ int sd_dhcp6_client_set_duid(sd_dhcp6_client *client, uint16_t type, uint8_t *du
 
         switch (type) {
         case DHCP6_DUID_LLT:
-                if (duid_len <= sizeof(client->duid.llt) - 2)
+                if (duid_len <= sizeof(client->duid.llt))
                         return -EINVAL;
                 break;
         case DHCP6_DUID_EN:
-                if (duid_len != sizeof(client->duid.en) - 2)
+                if (duid_len != sizeof(client->duid.en))
                         return -EINVAL;
                 break;
         case DHCP6_DUID_LL:
-                if (duid_len <= sizeof(client->duid.ll) - 2)
+                if (duid_len <= sizeof(client->duid.ll))
                         return -EINVAL;
                 break;
         case DHCP6_DUID_UUID:
-                if (duid_len != sizeof(client->duid.uuid) - 2)
+                if (duid_len != sizeof(client->duid.uuid))
                         return -EINVAL;
                 break;
         default:
@@ -221,9 +192,9 @@ int sd_dhcp6_client_set_duid(sd_dhcp6_client *client, uint16_t type, uint8_t *du
                 break;
         }
 
-        client->duid.raw.type = htobe16(type);
+        client->duid.type = htobe16(type);
         memcpy(&client->duid.raw.data, duid, duid_len);
-        client->duid_len = duid_len + 2;  /* +2 for sizeof(type) */
+        client->duid_len = duid_len + sizeof(client->duid.type);
 
         return 0;
 }
@@ -1289,7 +1260,7 @@ int sd_dhcp6_client_new(sd_dhcp6_client **ret)
         client->fd = -1;
 
         /* initialize DUID */
-        client->duid.en.type = htobe16(DHCP6_DUID_EN);
+        client->duid.type = htobe16(DHCP6_DUID_EN);
         client->duid.en.pen = htobe32(SYSTEMD_PEN);
         client->duid_len = sizeof(client->duid.en);