From 44481a8b537839cd9ffead4d261491641f5b5260 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Sat, 30 Aug 2014 18:31:21 -0400

Subject: [PATCH] sd-dhcp6-client: properly calculate buffer size when parsing

 options

Also make pointer calculations more explicit so they are

easier to understand.

---

 src/libsystemd-network/sd-dhcp6-client.c   | 5 ++++-

 src/libsystemd-network/test-dhcp6-client.c | 2 +-

 2 files changed, 5 insertions(+), 2 deletions(-)

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

index 342a231413..6860c66858 100644

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

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

@@ -583,12 +583,15 @@ static int client_parse_message(sd_dhcp6_client *client,

                                 DHCP6Message *message, size_t len,

                                 sd_dhcp6_lease *lease) {

         int r;

-        uint8_t *optval, *option = (uint8_t *)(message + 1), *id = NULL;

+        uint8_t *optval, *option, *id = NULL;

         uint16_t optcode, status;

         size_t optlen, id_len;

         bool clientid = false;

         be32_t iaid_lease;

+        option = (uint8_t *)message + sizeof(DHCP6Message);

+        len -= sizeof(DHCP6Message);

+

         while ((r = dhcp6_option_parse(&option, &len, &optcode, &optlen,

                                        &optval)) >= 0) {

                 switch (optcode) {

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

index 259db33bcd..d102a796b4 100644

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

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

@@ -205,7 +205,7 @@ static uint8_t msg_reply[173] = {

 static int test_advertise_option(sd_event *e) {

         _cleanup_dhcp6_lease_free_ sd_dhcp6_lease *lease = NULL;

         DHCP6Message *advertise = (DHCP6Message *)msg_advertise;

-        uint8_t *optval, *opt = &msg_advertise[sizeof(DHCP6Message)];

+        uint8_t *optval, *opt = msg_advertise + sizeof(DHCP6Message);

         uint16_t optcode;

         size_t optlen, len = sizeof(msg_advertise) - sizeof(DHCP6Message);

         be32_t val;