From 5e997388ba19e84764601d147ffb3bfb6cc455d1 Mon Sep 17 00:00:00 2001 From: Hans Dedecker Date: Mon, 31 Dec 2018 17:06:40 +0100 Subject: [PATCH] router: make announcing DNS info configurable (FS#2020) Make announcing options Recursive DNS server and DNS search list configurable via the ra_dns config option. This allows to disable sending RA based DNS info if such info is already provided by DHCPv6. Signed-off-by: Hans Dedecker --- README | 2 ++ src/config.c | 6 ++++++ src/odhcpd.h | 1 + src/router.c | 39 ++++++++++++++++++++++++--------------- 4 files changed, 33 insertions(+), 15 deletions(-) diff --git a/README b/README index 0c562e6..158b5b8 100644 --- a/README +++ b/README @@ -132,6 +132,8 @@ ra_hoplimit integer 0 Current hoplimit to be advertised in RA messages ra_mtu integer 0 MTU to be advertised in RA messages +ra_dns bool 1 Announce DNS configuration in + RA messages (RFC8106) ndproxy_routing bool 1 Learn routes from NDP ndproxy_slave bool 0 NDProxy external slave prefix_filter string ::/0 Only advertise on-link prefixes within diff --git a/src/config.c b/src/config.c index 9ffe1ac..29d7181 100644 --- a/src/config.c +++ b/src/config.c @@ -58,6 +58,7 @@ enum { IFACE_ATTR_RA_RETRANSTIME, IFACE_ATTR_RA_HOPLIMIT, IFACE_ATTR_RA_MTU, + IFACE_ATTR_RA_DNS, IFACE_ATTR_PD_MANAGER, IFACE_ATTR_PD_CER, IFACE_ATTR_NDPROXY_ROUTING, @@ -103,6 +104,7 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = { [IFACE_ATTR_RA_RETRANSTIME] = { .name = "ra_retranstime", .type = BLOBMSG_TYPE_INT32 }, [IFACE_ATTR_RA_HOPLIMIT] = { .name = "ra_hoplimit", .type = BLOBMSG_TYPE_INT32 }, [IFACE_ATTR_RA_MTU] = { .name = "ra_mtu", .type = BLOBMSG_TYPE_INT32 }, + [IFACE_ATTR_RA_DNS] = { .name = "ra_dns", .type = BLOBMSG_TYPE_BOOL }, [IFACE_ATTR_NDPROXY_ROUTING] = { .name = "ndproxy_routing", .type = BLOBMSG_TYPE_BOOL }, [IFACE_ATTR_NDPROXY_SLAVE] = { .name = "ndproxy_slave", .type = BLOBMSG_TYPE_BOOL }, [IFACE_ATTR_PREFIX_FILTER] = { .name = "prefix_filter", .type = BLOBMSG_TYPE_STRING }, @@ -218,6 +220,7 @@ static void set_interface_defaults(struct interface *iface) iface->ra_maxinterval = 600; iface->ra_mininterval = iface->ra_maxinterval/3; iface->ra_lifetime = -1; + iface->ra_dns = true; } static void clean_interface(struct interface *iface) @@ -704,6 +707,9 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr if ((c = tb[IFACE_ATTR_RA_USELEASETIME])) iface->ra_useleasetime = blobmsg_get_bool(c); + if ((c = tb[IFACE_ATTR_RA_DNS])) + iface->ra_dns = blobmsg_get_bool(c); + if ((c = tb[IFACE_ATTR_RA_PREFERENCE])) { const char *prio = blobmsg_get_string(c); diff --git a/src/odhcpd.h b/src/odhcpd.h index 80dbb40..10f26b1 100644 --- a/src/odhcpd.h +++ b/src/odhcpd.h @@ -193,6 +193,7 @@ struct interface { bool ra_not_onlink; bool ra_advrouter; bool ra_useleasetime; + bool ra_dns; bool no_dynamic_dhcp; uint8_t pio_filter_length; struct in6_addr pio_filter_addr; diff --git a/src/router.c b/src/router.c index f45ecab..f8a83a6 100644 --- a/src/router.c +++ b/src/router.c @@ -428,12 +428,14 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add struct in6_addr dns_pref, *dns_addr = NULL; size_t dns_cnt = 0; - if (iface->dns_cnt > 0) { - dns_addr = iface->dns; - dns_cnt = iface->dns_cnt; - } else if (!odhcpd_get_interface_dns_addr(iface, &dns_pref)) { - dns_addr = &dns_pref; - dns_cnt = 1; + if (iface->ra_dns) { + if (iface->dns_cnt > 0) { + dns_addr = iface->dns; + dns_cnt = iface->dns_cnt; + } else if (!odhcpd_get_interface_dns_addr(iface, &dns_pref)) { + dns_addr = &dns_pref; + dns_cnt = 1; + } } /* Construct Prefix Information options */ @@ -541,15 +543,22 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add } dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, 0}; /* DNS Search options */ - uint8_t search_buf[256], *search_domain = iface->search; - size_t search_len = iface->search_len, search_padded = 0; - - if (!search_domain && !res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) { - int len = dn_comp(_res.dnsrch[0], search_buf, - sizeof(search_buf), NULL, NULL); - if (len > 0) { - search_domain = search_buf; - search_len = len; + uint8_t *search_domain = NULL; + size_t search_len = 0, search_padded = 0; + + if (iface->ra_dns) { + search_len = iface->search_len; + search_domain = iface->search; + + if (!search_domain && !res_init() && _res.dnsrch[0] && _res.dnsrch[0][0]) { + uint8_t search_buf[256]; + + int len = dn_comp(_res.dnsrch[0], search_buf, + sizeof(search_buf), NULL, NULL); + if (len > 0) { + search_domain = search_buf; + search_len = len; + } } } -- 2.25.1