[ros-diffs] [reactos] 01/01: [DHCPCSVC] Change automatic address assignment to use hardware address

[Hervé Poussineau]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=1ff3d1c395644af497ccc…

commit 1ff3d1c395644af497cccc56dc1a548136a23ec4
Author:     Hervé Poussineau <hpoussin(a)reactos.org>
AuthorDate: Mon Apr 19 23:21:35 2021 +0200
Commit:     Hervé Poussineau <hpoussin(a)reactos.org>
CommitDate: Tue Apr 20 18:28:36 2021 +0200

    [DHCPCSVC] Change automatic address assignment to use hardware address
    
    According to RFC 3927, the pseudo-random number generation algorithm MUST be chosen
    so that different hosts do not generate the same sequence of numbers, and that the
    pseudo-random number generator SHOULD be seeded using a value derived from the
    IEEE 802 MAC address, so that a host will usually select the same IPv4 Link-Local
    address each time it is booted.
---
 base/services/dhcpcsvc/dhcp/dhclient.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/base/services/dhcpcsvc/dhcp/dhclient.c
b/base/services/dhcpcsvc/dhcp/dhclient.c
index f840f5b876c..81fcd9c5000 100644
--- a/base/services/dhcpcsvc/dhcp/dhclient.c
+++ b/base/services/dhcpcsvc/dhcp/dhclient.c
@@ -1069,6 +1069,8 @@ void
 state_panic(void *ipp)
 {
 	struct interface_info *ip = ipp;
+	uint16_t address_low;
+	int i;
         PDHCP_ADAPTER Adapter = AdapterFindInfo(ip);
 
 	note("No DHCPOFFERS received.");
@@ -1079,7 +1081,11 @@ state_panic(void *ipp)
             DbgPrint("DHCPCSVC: Failed to receive a response from a DHCP server. An
automatic private address will be assigned.\n");
 
             /* FIXME: The address generation code sucks */
-            AddIPAddress(htonl(0xA9FE0000 | (rand() % 0xFFFF)), //169.254.X.X
+            srand(0);
+            address_low = rand();
+            for (i = 0; i < ip->hw_address.hlen; i++)
+                address_low += ip->hw_address.haddr[i];
+            AddIPAddress(htonl(0xA9FE0000 | address_low), //169.254.X.X
                          htonl(0xFFFF0000), //255.255.0.0
                          Adapter->IfMib.dwIndex,
                          &Adapter->NteContext,