X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Flibsystemd-dhcp%2Fdhcp-client.c;h=68a3b1a1b64c319db8d186091c88530c4c2f1605;hb=0c6a3c888abd720b5ab28162d1ba4eadffde5272;hp=18a6e3c50d725cb93ed06df60cd708267284e9c1;hpb=2ed0375c2db786012842f02b84014a70c4806017;p=elogind.git

diff --git a/src/libsystemd-dhcp/dhcp-client.c b/src/libsystemd-dhcp/dhcp-client.c
index 18a6e3c50..68a3b1a1b 100644
--- a/src/libsystemd-dhcp/dhcp-client.c
+++ b/src/libsystemd-dhcp/dhcp-client.c
@@ -382,10 +382,13 @@ static uint16_t client_checksum(void *buf, int len)
 
         if (len & 0x01) {
                 odd = buf;
-                sum += odd[len];
+                sum += odd[len - 1];
         }
 
-        return ~((sum & 0xffff) + (sum >> 16));
+        while (sum >> 16)
+                sum = (sum & 0xffff) + (sum >> 16);
+
+        return ~sum;
 }
 
 static void client_append_ip_headers(DHCPPacket *packet, uint16_t len)
@@ -731,8 +734,15 @@ static int client_receive_ack(sd_dhcp_client *client, DHCPPacket *offer,
         len = len - DHCP_IP_UDP_SIZE;
         r = dhcp_option_parse(&offer->dhcp, len, client_parse_offer, lease);
 
-        if (r != DHCP_ACK)
+        if (r == DHCP_NAK) {
+                r = DHCP_EVENT_NO_LEASE;
+                goto error;
+        }
+
+        if (r != DHCP_ACK) {
+                r = -ENOMSG;
                 goto error;
+        }
 
         lease->address = offer->dhcp.yiaddr;