On 17 July 2021 13:16:59 CEST, Bjorn Ketelaars <b...@openbsd.org> wrote:
>An inconsistency exists between dhclient(8) and dhcpleased(8) when
>receiving the Classless Static Routes option: dhcpleased creates a
>default route, while dhclient does not.
>
>If I'm not mistaken, the behaviour of dhclient is correct. From
>rfc3442:
>"If the DHCP server returns both a Classless Static Routes option and a
>Router option, the DHCP client MUST ignore the Router option."
>
Correct. But you are fixing it in the wrong place. It doesn't say to ignore a
default route, which can be transmitted via classless static routes option
(it's 0/0).
You need to fix this in parse_dhcp in engine.c
>Comments?
>
>
>diff --git sbin/dhcpleased/dhcpleased.c sbin/dhcpleased/dhcpleased.c
>index 2157406e71a..93df9f55e7f 100644
>--- sbin/dhcpleased/dhcpleased.c
>+++ sbin/dhcpleased/dhcpleased.c
>@@ -819,7 +819,7 @@ configure_routes(uint8_t rtm_type, struct
>imsg_configure_interface *imsg)
> {
> struct sockaddr_in dst, mask, gw, ifa;
> in_addr_t addrnet, gwnet;
>- int i;
>+ int csr = 0, i;
>
> memset(&ifa, 0, sizeof(ifa));
> ifa.sin_family = AF_INET;
>@@ -840,6 +840,13 @@ configure_routes(uint8_t rtm_type, struct
>imsg_configure_interface *imsg)
>
> addrnet = imsg->addr.s_addr & imsg->mask.s_addr;
>
>+ for (i = 0; i < imsg->routes_len; i++) {
>+ if (imsg->routes[i].dst.s_addr != INADDR_ANY) {
>+ csr = 1;
>+ break;
>+ }
>+ }
>+
> for (i = 0; i < imsg->routes_len; i++) {
> dst.sin_addr.s_addr = imsg->routes[i].dst.s_addr;
> mask.sin_addr.s_addr = imsg->routes[i].mask.s_addr;
>@@ -872,6 +879,15 @@ configure_routes(uint8_t rtm_type, struct
>imsg_configure_interface *imsg)
> /* directly connected default */
> configure_route(rtm_type, imsg->if_index,
> imsg->rdomain, &dst, &mask, &gw, NULL, 0);
>+ } else if (csr) {
>+ /*
>+ * RFC3442 states that if the DHCP server returns
>+ * both a Classless Static Routes option and a
>+ * Router option, the DHCP client MUST ignore the
>+ * Router option.
>+ */
>+ log_warnx("%s: ignoring router option",
>+ __func__);
> } else {
> /* default route via gateway */
> configure_route(rtm_type, imsg->if_index,
--
Sent from a mobile device. Please excuse poor formatting.
