netifd: add segment routing support

seg6_enabled - Bool
  Accept or drop SR-enabled IPv6 packets on this interface.

More Information:
https://www.kernel.org/doc/html/latest/networking/seg6-sysctl.html

Now you can set as interface option
  option ip6segmentrouting '1'

It is not enough to turn on "seg6_enabled" on the interface. Further,
we have to enable "/all/seg6_enabled". This means that a working config
is "interface + all".

Signed-off-by: Nick Hainke <vincent@systemli.org>
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com> [style fixes]

3 files changed, 51 insertions, 0 deletions

diff --git a/device.c b/device.c
index 73cc4bf..4243c18 100644
--- a/device.c
+++ b/device.c
@@ -36,6 +36,7 @@ static const struct blobmsg_policy dev_attrs[__DEV_ATTR_MAX] = {
 	[DEV_ATTR_TXQUEUELEN] = { .name = "txqueuelen", .type = BLOBMSG_TYPE_INT32 },
 	[DEV_ATTR_ENABLED] = { .name = "enabled", .type = BLOBMSG_TYPE_BOOL },
 	[DEV_ATTR_IPV6] = { .name = "ipv6", .type = BLOBMSG_TYPE_BOOL },
+	[DEV_ATTR_IP6SEGMENTROUTING] = { .name = "ip6segmentrouting", .type = BLOBMSG_TYPE_BOOL },
 	[DEV_ATTR_PROMISC] = { .name = "promisc", .type = BLOBMSG_TYPE_BOOL },
 	[DEV_ATTR_RPFILTER] = { .name = "rpfilter", .type = BLOBMSG_TYPE_STRING },
 	[DEV_ATTR_ACCEPTLOCAL] = { .name = "acceptlocal", .type = BLOBMSG_TYPE_BOOL },
@@ -230,6 +231,7 @@ device_merge_settings(struct device *dev, struct device_settings *n)
 		(s->flags & (DEV_OPT_MACADDR|DEV_OPT_DEFAULT_MACADDR) ? s->macaddr : os->macaddr),
 		sizeof(n->macaddr));
 	n->ipv6 = s->flags & DEV_OPT_IPV6 ? s->ipv6 : os->ipv6;
+	n->ip6segmentrouting = s->flags & DEV_OPT_IP6SEGMENTROUTING ? s->ip6segmentrouting : os->ip6segmentrouting;
 	n->promisc = s->flags & DEV_OPT_PROMISC ? s->promisc : os->promisc;
 	n->rpfilter = s->flags & DEV_OPT_RPFILTER ? s->rpfilter : os->rpfilter;
 	n->acceptlocal = s->flags & DEV_OPT_ACCEPTLOCAL ? s->acceptlocal : os->acceptlocal;
@@ -299,6 +301,11 @@ device_init_settings(struct device *dev, struct blob_attr **tb)
 		s->flags |= DEV_OPT_IPV6;
 	}
 
+	if ((cur = tb[DEV_ATTR_IP6SEGMENTROUTING])) {
+		s->ip6segmentrouting = blobmsg_get_bool(cur);
+		s->flags |= DEV_OPT_IP6SEGMENTROUTING;
+	}
+
 	if ((cur = tb[DEV_ATTR_PROMISC])) {
 		s->promisc = blobmsg_get_bool(cur);
 		s->flags |= DEV_OPT_PROMISC;
@@ -844,6 +851,18 @@ device_init_pending(void)
 	}
 }
 
+bool
+device_check_ip6segmentrouting(void)
+{
+	struct device *dev;
+	bool ip6segmentrouting = false;
+
+	avl_for_each_element(&devices, dev, avl)
+		ip6segmentrouting |= dev->settings.ip6segmentrouting;
+
+	return ip6segmentrouting;
+}
+
 static enum dev_change_type
 device_set_config(struct device *dev, struct device_type *type,
 		  struct blob_attr *attr)
@@ -1053,6 +1072,8 @@ device_dump_status(struct blob_buf *b, struct device *dev)
 			blobmsg_add_u32(b, "txqueuelen", st.txqueuelen);
 		if (st.flags & DEV_OPT_IPV6)
 			blobmsg_add_u8(b, "ipv6", st.ipv6);
+		if (st.flags & DEV_OPT_IP6SEGMENTROUTING)
+			blobmsg_add_u8(b, "ip6segmentrouting", st.ip6segmentrouting);
 		if (st.flags & DEV_OPT_PROMISC)
 			blobmsg_add_u8(b, "promisc", st.promisc);
 		if (st.flags & DEV_OPT_RPFILTER)
diff --git a/device.h b/device.h
index ab5a162..dc410b4 100644
--- a/device.h
+++ b/device.h
@@ -53,6 +53,7 @@ enum {
 	DEV_ATTR_SENDREDIRECTS,
 	DEV_ATTR_NEIGHLOCKTIME,
 	DEV_ATTR_ISOLATE,
+	DEV_ATTR_IP6SEGMENTROUTING,
 	__DEV_ATTR_MAX,
 };
 
@@ -107,6 +108,7 @@ enum {
 	DEV_OPT_SENDREDIRECTS		= (1 << 21),
 	DEV_OPT_NEIGHLOCKTIME		= (1 << 22),
 	DEV_OPT_ISOLATE			= (1 << 23),
+	DEV_OPT_IP6SEGMENTROUTING	= (1 << 24),
 };
 
 /* events broadcasted to all users of a device */
@@ -173,6 +175,7 @@ struct device_settings {
 	bool learning;
 	bool unicast_flood;
 	bool sendredirects;
+	bool ip6segmentrouting;
 	bool isolate;
 };
 
@@ -320,4 +323,6 @@ device_set_disabled(struct device *dev, bool value)
 	device_refresh_present(dev);
 }
 
+bool device_check_ip6segmentrouting(void);
+
 #endif
diff --git a/system-linux.c b/system-linux.c
index bf746f9..c57ecab 100644
--- a/system-linux.c
+++ b/system-linux.c
@@ -304,6 +304,11 @@ static void system_set_disable_ipv6(struct device *dev, const char *val)
 	system_set_dev_sysctl("/proc/sys/net/ipv6/conf/%s/disable_ipv6", dev->ifname, val);
 }
 
+static void system_set_ip6segmentrouting(struct device *dev, const char *val)
+{
+	system_set_dev_sysctl("/proc/sys/net/ipv6/conf/%s/seg6_enabled", dev->ifname, val);
+}
+
 static void system_set_rpfilter(struct device *dev, const char *val)
 {
 	system_set_dev_sysctl("/proc/sys/net/ipv4/conf/%s/rp_filter", dev->ifname, val);
@@ -509,6 +514,12 @@ static int system_get_disable_ipv6(struct device *dev, char *buf, const size_t b
 			dev->ifname, buf, buf_sz);
 }
 
+static int system_get_ip6segmentrouting(struct device *dev, char *buf, const size_t buf_sz)
+{
+	return system_get_dev_sysctl("/proc/sys/net/ipv6/conf/%s/seg6_enabled",
+			dev->ifname, buf, buf_sz);
+}
+
 static int system_get_rpfilter(struct device *dev, char *buf, const size_t buf_sz)
 {
 	return system_get_dev_sysctl("/proc/sys/net/ipv4/conf/%s/rp_filter",
@@ -1572,6 +1583,11 @@ system_if_get_settings(struct device *dev, struct device_settings *s)
 		s->flags |= DEV_OPT_IPV6;
 	}
 
+	if (!system_get_ip6segmentrouting(dev, buf, sizeof(buf))) {
+		s->ip6segmentrouting = strtoul(buf, NULL, 0);
+		s->flags |= DEV_OPT_IP6SEGMENTROUTING;
+	}
+
 	if (ioctl(sock_ioctl, SIOCGIFFLAGS, &ifr) == 0) {
 		s->promisc = ifr.ifr_flags & IFF_PROMISC;
 		s->flags |= DEV_OPT_PROMISC;
@@ -1667,6 +1683,15 @@ system_if_apply_settings(struct device *dev, struct device_settings *s, unsigned
 	}
 	if (apply_mask & DEV_OPT_IPV6)
 		system_set_disable_ipv6(dev, s->ipv6 ? "0" : "1");
+	if (s->flags & DEV_OPT_IP6SEGMENTROUTING & apply_mask) {
+		struct device dummy = {
+			.ifname = "all",
+		};
+		bool ip6segmentrouting = device_check_ip6segmentrouting();
+
+		system_set_ip6segmentrouting(dev, s->ip6segmentrouting ? "1" : "0");
+		system_set_ip6segmentrouting(&dummy, ip6segmentrouting ? "1" : "0");
+	}
 	if (apply_mask & DEV_OPT_PROMISC) {
 		if (system_if_flags(dev->ifname, s->promisc ? IFF_PROMISC : 0,
 				    !s->promisc ? IFF_PROMISC : 0) < 0)