From: Pali Rohár <pali@kernel.org>
Date: Sat, 9 Jan 2021 13:37:00 +0000 (+0100)
Subject: ipv6cp: Allow to use demand mode without specifying IPv6 address/identifier
X-Git-Tag: ppp-2.5.0~92^2~2
X-Git-Url: https://git.ozlabs.org/?a=commitdiff_plain;h=8945d9b7679bb4f83d096db3caae4749e44886d8;hp=8ebe7550b2a4525afcf3adee3411250fb32be769;p=ppp.git

ipv6cp: Allow to use demand mode without specifying IPv6 address/identifier

Support is similar as in IPv4, pppd generates random temporary identifier
for LL address and after connection is established then LL address is
changed to the real one.

Signed-off-by: Pali Rohár <pali@kernel.org>
---

diff --git a/pppd/ipv6cp.c b/pppd/ipv6cp.c
index 431cb62..98b9e95 100644
--- a/pppd/ipv6cp.c
+++ b/pppd/ipv6cp.c
@@ -528,7 +528,8 @@ ipv6cp_resetci(fsm *f)
     
     if (!wo->opt_local) {
 	wo->accept_local = 1;
-	eui64_magic_nz(wo->ourid);
+	if (!demand)
+	    eui64_magic_nz(wo->ourid);
     }
     if (!wo->opt_remote)
 	wo->accept_remote = 1;
@@ -1140,11 +1141,6 @@ ipv6_check_options(void)
 		wo->opt_remote = 1;
 	}
     }
-
-    if (demand && (eui64_iszero(wo->ourid) || eui64_iszero(wo->hisid))) {
-	option_error("local/remote LL address required for demand-dialling\n");
-	exit(EXIT_OPTION_ERROR);
-    }
 }
 
 
@@ -1157,6 +1153,15 @@ ipv6_demand_conf(int u)
 {
     ipv6cp_options *wo = &ipv6cp_wantoptions[u];
 
+    if (eui64_iszero(wo->hisid)) {
+	/* make up an arbitrary identifier for the peer */
+	eui64_magic_nz(wo->hisid);
+    }
+    if (eui64_iszero(wo->ourid)) {
+	/* make up an arbitrary identifier for us */
+	eui64_magic_nz(wo->ourid);
+    }
+
     if (!sif6up(u))
 	return 0;
     if (!sif6addr(u, wo->ourid, wo->hisid))