diff options
Diffstat (limited to 'dnsmasq-2.86-alternative-lease.patch')
| -rw-r--r-- | dnsmasq-2.86-alternative-lease.patch | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/dnsmasq-2.86-alternative-lease.patch b/dnsmasq-2.86-alternative-lease.patch new file mode 100644 index 0000000..e51d2b3 --- /dev/null +++ b/dnsmasq-2.86-alternative-lease.patch @@ -0,0 +1,107 @@ +From 268080fc19990711a1d1e1acd68a50aa2f6cb5fb Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com> +Date: Fri, 17 Sep 2021 20:12:21 +0200 +Subject: [PATCH] Offer alternative DHCPv6 address if requested is taken + +In some cases multiple requests might arrive from single DUID. It may +happen just one address is offered to different IAID requests. When +the first request confirms lease, another would be offered alternative +address instead of address in use error. + +Includes check on such Rapid commit equivalents and returns NotOnLink +error, required by RFC 8145, if requested address were not on any +supported prefix. +--- + src/rfc3315.c | 39 ++++++++++++++++++++++++++++----------- + 1 file changed, 28 insertions(+), 11 deletions(-) + +diff --git a/src/rfc3315.c b/src/rfc3315.c +index 5c2ff97..d1534ad 100644 +--- a/src/rfc3315.c ++++ b/src/rfc3315.c +@@ -614,7 +614,7 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_ + + case DHCP6SOLICIT: + { +- int address_assigned = 0; ++ int address_assigned = 0, ia_invalid = 0; + /* tags without all prefix-class tags */ + struct dhcp_netid *solicit_tags; + struct dhcp_context *c; +@@ -697,6 +697,8 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_ + get_context_tag(state, c); + address_assigned = 1; + } ++ else ++ ia_invalid++; + } + + /* Suggest configured address(es) */ +@@ -782,11 +784,26 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_ + tagif = add_options(state, 0); + } + else +- { ++ { ++ char *errmsg; + /* no address, return error */ + o1 = new_opt6(OPTION6_STATUS_CODE); +- put_opt6_short(DHCP6NOADDRS); +- put_opt6_string(_("no addresses available")); ++ if (state->lease_allocate && ia_invalid) ++ { ++ /* RFC 8415, Section 18.3.2: ++ If any of the prefixes of the included addresses are not ++ appropriate for the link to which the client is connected, ++ the server MUST return the IA to the client with a Status ++ Code option with the value NotOnLink. */ ++ put_opt6_short(DHCP6NOTONLINK); ++ errmsg = _("not on link"); ++ } ++ else ++ { ++ put_opt6_short(DHCP6NOADDRS); ++ errmsg = _("no addresses available"); ++ } ++ put_opt6_string(errmsg); + end_opt6(o1); + + /* Some clients will ask repeatedly when we're not giving +@@ -795,7 +812,7 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_ + for (c = state->context; c; c = c->current) + if (!(c->flags & CONTEXT_RA_STATELESS)) + { +- log6_packet(state, state->lease_allocate ? "DHCPREPLY" : "DHCPADVERTISE", NULL, _("no addresses available")); ++ log6_packet(state, state->lease_allocate ? "DHCPREPLY" : "DHCPADVERTISE", NULL, errmsg); + break; + } + } +@@ -831,7 +848,7 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_ + /* If we get a request with an IA_*A without addresses, treat it exactly like + a SOLICT with rapid commit set. */ + save_counter(start); +- goto request_no_address; ++ goto request_no_address; + } + + o = build_ia(state, &t1cntr); +@@ -861,11 +878,11 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_ + } + else if (!check_address(state, &req_addr)) + { +- /* Address leased to another DUID/IAID */ +- o1 = new_opt6(OPTION6_STATUS_CODE); +- put_opt6_short(DHCP6UNSPEC); +- put_opt6_string(_("address in use")); +- end_opt6(o1); ++ /* Address leased to another DUID/IAID. ++ Find another address for the client, treat it exactly like ++ a SOLICT with rapid commit set. */ ++ save_counter(start); ++ goto request_no_address; + } + else + { +-- +2.31.1 + |