router: make RA flags configurable (FS#2019)

Replace the config option ra_management by the config options ra_flags
and ra_slaac. The latter allows to configure the autonomous-address
config flag used for stateless address configuration while the former
allows to configure the RA flags in the form of a list.
The list can hold the following values :
	managed-config
	other-config
	home-agent
	none

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

README

@@ -111,8 +111,10 @@ limit			integer	150			DHCPv4 pool size
 
 ra_default		integer	0			Override default route
 			0: default, 1: ignore no public address, 2: ignore all
-ra_management		integer	1			RA management mode
-			0: no M-Flag but A-Flag, 1: both M and A, 2: M but not A
+ra_flags		list	other-config		List of RA flags to be
+							advertised in RA messages
+			[managed-config other-config home-agent none]
+ra_slaac		bool	1			Announce slaac for a prefix
 ra_offlink		bool	0			Announce prefixes off-link
 ra_preference		string	medium			Route(r) preference
 			[medium|high|low]

src/config.c

@@ -59,7 +59,8 @@ enum {
 	IFACE_ATTR_DHCPV6_PD,
 	IFACE_ATTR_DHCPV6_NA,
 	IFACE_ATTR_RA_DEFAULT,
-	IFACE_ATTR_RA_MANAGEMENT,
+	IFACE_ATTR_RA_FLAGS,
+	IFACE_ATTR_RA_SLAAC,
 	IFACE_ATTR_RA_OFFLINK,
 	IFACE_ATTR_RA_PREFERENCE,
 	IFACE_ATTR_RA_ADVROUTER,
@@ -106,7 +107,8 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
 	[IFACE_ATTR_PD_MANAGER] = { .name = "pd_manager", .type = BLOBMSG_TYPE_STRING },
 	[IFACE_ATTR_PD_CER] = { .name = "pd_cer", .type = BLOBMSG_TYPE_STRING },
 	[IFACE_ATTR_RA_DEFAULT] = { .name = "ra_default", .type = BLOBMSG_TYPE_INT32 },
-	[IFACE_ATTR_RA_MANAGEMENT] = { .name = "ra_management", .type = BLOBMSG_TYPE_INT32 },
+	[IFACE_ATTR_RA_FLAGS] = { .name = "ra_flags", . type = BLOBMSG_TYPE_ARRAY },
+	[IFACE_ATTR_RA_SLAAC] = { .name = "ra_slaac", .type = BLOBMSG_TYPE_BOOL },
 	[IFACE_ATTR_RA_OFFLINK] = { .name = "ra_offlink", .type = BLOBMSG_TYPE_BOOL },
 	[IFACE_ATTR_RA_PREFERENCE] = { .name = "ra_preference", .type = BLOBMSG_TYPE_STRING },
 	[IFACE_ATTR_RA_ADVROUTER] = { .name = "ra_advrouter", .type = BLOBMSG_TYPE_BOOL },
@@ -182,6 +184,14 @@ const struct uci_blob_param_list odhcpd_attr_list = {
 	.params = odhcpd_attrs,
 };
 
+static const struct { const char *name; uint8_t flag; } ra_flags[] = {
+	{ .name = "managed-config", .flag = ND_RA_FLAG_MANAGED },
+	{ .name = "other-config", .flag = ND_RA_FLAG_OTHER },
+	{ .name = "home-agent", .flag = ND_RA_FLAG_HOME_AGENT },
+	{ .name = "none", . flag = 0 },
+	{ .name = NULL, },
+};
+
 static int mkdir_p(char *dir, mode_t mask)
 {
 	char *l = strrchr(dir, '/');
@@ -221,7 +231,8 @@ static void set_interface_defaults(struct interface *iface)
 	iface->dhcpv6_assignall = true;
 	iface->dhcpv6_pd = true;
 	iface->dhcpv6_na = true;
-	iface->ra_managed = RA_MANAGED_MFLAG;
+	iface->ra_flags = ND_RA_FLAG_OTHER;
+	iface->ra_slaac = true;
 	iface->ra_maxinterval = 600;
 	iface->ra_mininterval = iface->ra_maxinterval/3;
 	iface->ra_lifetime = -1;
@@ -273,6 +284,34 @@ static int parse_mode(const char *mode)
 		return -1;
 }
 
+static int parse_ra_flags(uint8_t *flags, struct blob_attr *attr)
+{
+	struct blob_attr *cur;
+	unsigned rem;
+
+	blobmsg_for_each_attr(cur, attr, rem) {
+		int i;
+
+		if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
+			continue;
+
+                if (!blobmsg_check_attr(cur, false))
+                        continue;
+
+		for (i = 0; ra_flags[i].name; i++) {
+			if (!strcmp(ra_flags[i].name, blobmsg_get_string(cur))) {
+				*flags |= ra_flags[i].flag;
+				break;
+			}
+		}
+
+		if (!ra_flags[i].name)
+			return -1;
+	}
+
+	return 0;
+}
+
 static void set_config(struct uci_section *s)
 {
 	struct blob_attr *tb[ODHCPD_ATTR_MAX], *c;
@@ -695,8 +734,11 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 	if ((c = tb[IFACE_ATTR_RA_DEFAULT]))
 		iface->default_router = blobmsg_get_u32(c);
 
-	if ((c = tb[IFACE_ATTR_RA_MANAGEMENT]))
-		iface->ra_managed = blobmsg_get_u32(c);
+	if ((c = tb[IFACE_ATTR_RA_FLAGS])) {
+		iface->ra_flags = 0;
+		if (parse_ra_flags(&iface->ra_flags, c) < 0)
+			goto err;
+	}
 
 	if ((c = tb[IFACE_ATTR_RA_REACHABLETIME])) {
 		uint32_t ra_reachabletime = blobmsg_get_u32(c);
@@ -730,6 +772,9 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 		iface->ra_mtu = ra_mtu;
 	}
 
+	if ((c = tb[IFACE_ATTR_RA_SLAAC]))
+		iface->ra_slaac = blobmsg_get_bool(c);
+
 	if ((c = tb[IFACE_ATTR_RA_OFFLINK]))
 		iface->ra_not_onlink = blobmsg_get_bool(c);
 

src/dhcpv6-ia.c

@@ -687,7 +687,7 @@ static void handle_addrlist_change(struct netevent_handler_info *info)
 	time_t now = odhcpd_time();
 
 	list_for_each_entry(c, &iface->ia_assignments, head) {
-		if (c != border && iface->ra_managed == RA_MANAGED_NO_MFLAG
+		if (c != border && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
 				&& (c->flags & OAF_BOUND))
 			__apply_lease(iface, c, info->addrs_old.addrs,
 					info->addrs_old.len, false);

src/odhcpd.h

@@ -246,6 +246,13 @@ struct interface {
 	bool master;
 	bool ignore;
 	bool always_rewrite_dns;
+
+	// NDP
+	int learn_routes;
+
+	// RA
+	uint8_t ra_flags;
+	bool ra_slaac;
 	bool ra_not_onlink;
 	bool ra_advrouter;
 	bool ra_useleasetime;
@@ -253,11 +260,7 @@ struct interface {
 	bool no_dynamic_dhcp;
 	uint8_t pio_filter_length;
 	struct in6_addr pio_filter_addr;
-
-	// RA
-	int learn_routes;
 	int default_router;
-	int ra_managed;
 	int route_preference;
 	int ra_maxinterval;
 	int ra_mininterval;
@@ -303,10 +306,6 @@ struct interface {
 
 extern struct avl_tree interfaces;
 
-#define RA_MANAGED_NO_MFLAG	0
-#define RA_MANAGED_MFLAG	1
-#define RA_MANAGED_NO_AFLAG	2
-
 inline static void free_assignment(struct dhcp_assignment *a)
 {
 	list_del(&a->head);

src/router.c

@@ -436,12 +436,7 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 	if (hlim > 0)
 		adv.h.nd_ra_curhoplimit = hlim;
 
-	if (iface->dhcpv6 != MODE_DISABLED) {
-		adv.h.nd_ra_flags_reserved = ND_RA_FLAG_OTHER;
-
-		if (iface->ra_managed >= RA_MANAGED_MFLAG)
-			adv.h.nd_ra_flags_reserved |= ND_RA_FLAG_MANAGED;
-	}
+	adv.h.nd_ra_flags_reserved = iface->ra_flags;
 
 	if (iface->route_preference < 0)
 		adv.h.nd_ra_flags_reserved |= ND_RA_PREF_LOW;
@@ -558,7 +553,7 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 		p->nd_opt_pi_flags_reserved = 0;
 		if (!iface->ra_not_onlink)
 			p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
-		if (iface->ra_managed < RA_MANAGED_NO_AFLAG && addr->prefix <= 64)
+		if (iface->ra_slaac && addr->prefix <= 64)
 			p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
 		if (iface->ra_advrouter)
 			p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_RADDR;