From 66eac1201a9c1596f5901f8dbbf24bda7e350878 Mon Sep 17 00:00:00 2001

From: Dan Williams <dcbw@redhat.com>

Date: Fri, 26 Sep 2014 15:12:36 -0500

Subject: [PATCH] sd-dhcp6-client: support custom DUIDs

The caller may have an existing DUID that it wants to use, and may

want to use some other DUID generation scheme than systemd's

default DUID-EN.

[tomegun: whitespace - we never use tabs]

---

 src/libsystemd-network/sd-dhcp6-client.c | 43 +++++++++++++++++++++++---------

 src/systemd/sd-dhcp6-client.h            |  2 ++

 2 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c

index c190b560ea..130fe43cf2 100644

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

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

@@ -39,6 +39,8 @@

 #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)

+#define MAX_DUID_LEN 32

+

 struct sd_dhcp6_client {

         RefCount n_ref;

@@ -62,12 +64,8 @@ struct sd_dhcp6_client {

         sd_event_source *timeout_resend_expire;

         sd_dhcp6_client_cb_t cb;

         void *userdata;

-

-        struct duid_en {

-                uint16_t type; /* DHCP6_DUID_EN */

-                uint32_t pen;

-                uint8_t id[8];

-        } _packed_ duid;

+        uint8_t duid[MAX_DUID_LEN];

+        size_t duid_len;

 };

 static const uint16_t default_req_opts[] = {

@@ -147,6 +145,19 @@ int sd_dhcp6_client_set_mac(sd_dhcp6_client *client,

         return 0;

 }

+int sd_dhcp6_client_set_duid(sd_dhcp6_client *client, uint8_t *duid,

+                             size_t duid_len)

+{

+        assert_return(client, -EINVAL);

+        assert_return(duid, -EINVAL);

+        assert_return(duid_len > 0 && duid_len <= MAX_DUID_LEN, -EINVAL);

+

+        memcpy(&client->duid, duid, duid_len);

+        client->duid_len = duid_len;

+

+        return 0;

+}

+

 int sd_dhcp6_client_set_request_option(sd_dhcp6_client *client,

                                        uint16_t option) {

         size_t t;

@@ -308,7 +319,7 @@ static int client_send_message(sd_dhcp6_client *client, usec_t time_now) {

                 return r;

         r = dhcp6_option_append(&opt, &optlen, DHCP6_OPTION_CLIENTID,

-                                sizeof(client->duid), &client->duid);

+                                client->duid_len, &client->duid);

         if (r < 0)

                 return r;

@@ -616,7 +627,7 @@ static int client_parse_message(sd_dhcp6_client *client,

                                 return -EINVAL;

                         }

-                        if (optlen != sizeof(client->duid) ||

+                        if (optlen != client->duid_len ||

                             memcmp(&client->duid, optval, optlen) != 0) {

                                 log_dhcp6_client(client, "%s DUID does not match",

                                                  dhcp6_message_type_to_string(message->type));

@@ -1116,9 +1127,16 @@ sd_dhcp6_client *sd_dhcp6_client_unref(sd_dhcp6_client *client) {

         return client;

 }

+struct duid_en {

+        uint16_t type; /* DHCP6_DUID_EN */

+        uint32_t pen;

+        uint8_t id[8];

+} _packed_;

+

 int sd_dhcp6_client_new(sd_dhcp6_client **ret)

 {

         _cleanup_dhcp6_client_unref_ sd_dhcp6_client *client = NULL;

+        struct duid_en *duid;

         sd_id128_t machine_id;

         int r;

         size_t t;

@@ -1138,8 +1156,9 @@ int sd_dhcp6_client_new(sd_dhcp6_client **ret)

         client->fd = -1;

         /* initialize DUID */

-        client->duid.type = htobe16(DHCP6_DUID_EN);

-        client->duid.pen = htobe32(SYSTEMD_PEN);

+        duid = (struct duid_en *) &client->duid;

+        duid->type = htobe16(DHCP6_DUID_EN);

+        duid->pen = htobe32(SYSTEMD_PEN);

         r = sd_id128_get_machine(&machine_id);

         if (r < 0)

@@ -1147,8 +1166,8 @@ int sd_dhcp6_client_new(sd_dhcp6_client **ret)

         /* a bit of snake-oil perhaps, but no need to expose the machine-id

            directly */

-        siphash24(client->duid.id, &machine_id, sizeof(machine_id),

-                  HASH_KEY.bytes);

+        siphash24(duid->id, &machine_id, sizeof(machine_id), HASH_KEY.bytes);

+        client->duid_len = sizeof (struct duid_en);

         client->req_opts_len = ELEMENTSOF(default_req_opts);

diff --git a/src/systemd/sd-dhcp6-client.h b/src/systemd/sd-dhcp6-client.h

index 93edcc41fc..7b7f098b0c 100644

--- a/src/systemd/sd-dhcp6-client.h

+++ b/src/systemd/sd-dhcp6-client.h

@@ -45,6 +45,8 @@ int sd_dhcp6_client_set_callback(sd_dhcp6_client *client,

 int sd_dhcp6_client_set_index(sd_dhcp6_client *client, int interface_index);

 int sd_dhcp6_client_set_mac(sd_dhcp6_client *client,

                             const struct ether_addr *mac_addr);

+int sd_dhcp6_client_set_duid(sd_dhcp6_client *client, uint8_t *duid,

+                             size_t duid_len);

 int sd_dhcp6_client_set_request_option(sd_dhcp6_client *client,

                                        uint16_t option);