From 3ebbd0bf4f154ea9ea668d11b3a8d3a702552b6b Mon Sep 17 00:00:00 2001
From: Joachim Wiberg <troglobit@gmail.com>
Date: Thu, 21 Mar 2024 05:47:49 +0100
Subject: [PATCH] confd: handle small changes to bridge port properties

This patch adds support for small incremental changes to bridge ports.
Changes where the libyang diff does not include a bridge reference so
that it will have to be synthesized from the current configuration.

For example, forgetting to set a port's PVID in a VLAN filtering bridge
setup, changing a bridge port's multicast flooding properties, or any
other per-bridge-port setting after the fact.

Fixes #349.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
---
 src/confd/src/ietf-interfaces.c | 93 +++++++++++++++++++++++++++++++--
 1 file changed, 88 insertions(+), 5 deletions(-)

diff --git a/src/confd/src/ietf-interfaces.c b/src/confd/src/ietf-interfaces.c
index c22ad4b8..b7ed76e6 100644
--- a/src/confd/src/ietf-interfaces.c
+++ b/src/confd/src/ietf-interfaces.c
@@ -745,6 +745,57 @@ static int netdag_gen_ethtool(struct dagger *net, struct lyd_node *cif, struct l
 	return 0;
 }
 
+static void brport_pvid_adjust(FILE *br, struct lyd_node *vlan, int vid, const char *brport,
+			       struct lydx_diff *pvidiff, int tagged)
+{
+	const char *type = tagged ? "tagged" : "untagged";
+	struct lyd_node *port;
+
+	LYX_LIST_FOR_EACH(lyd_child(vlan), port, type) {
+		if (strcmp(brport, lyd_get_value(port)))
+			continue;
+
+		if (pvidiff->old && atoi(pvidiff->old) == vid)
+			fprintf(br, "vlan add vid %d dev %s %s\n", vid, brport, type);
+		if (pvidiff->new && atoi(pvidiff->new) == vid)
+			fprintf(br, "vlan add vid %d dev %s pvid %s\n", vid, brport, type);
+	}
+}
+
+/*
+ * Called when only pvid is changed for a bridge-port.  Then we use the
+ * cif data to iterate over all known VLANS for the given port.
+ */
+static int bridge_port_vlans(struct dagger *net, struct lyd_node *cif, const char *brname,
+			     const char *brport, struct lydx_diff *pvidiff)
+{
+	struct lyd_node *bridge = lydx_find_by_name(lyd_parent(cif), "interface", brname);
+	struct lyd_node *vlan, *vlans;
+	int err = 0;
+	FILE *br;
+
+	vlans  = lydx_get_descendant(lyd_child(bridge), "bridge", "vlans", NULL);
+	if (!vlans)
+		goto done;
+
+	br = dagger_fopen_next(net, "init", brname, 60, "init.bridge");
+	if (!br) {
+		err = -EIO;
+		goto done;
+	}
+
+	LYX_LIST_FOR_EACH(lyd_child(vlans), vlan, "vlan") {
+		int vid = atoi(lydx_get_cattr(vlan, "vid"));
+
+		brport_pvid_adjust(br, vlan, vid, brport, pvidiff, 0);
+		brport_pvid_adjust(br, vlan, vid, brport, pvidiff, 1);
+	}
+
+	fclose(br);
+done:
+	return err;
+}
+
 static int bridge_diff_vlan_port(struct dagger *net, FILE *br, const char *brname, int vid,
 				       const char *brport, int tagged, enum lydx_op op)
 {
@@ -877,20 +928,52 @@ static void bridge_port_settings(FILE *next, const char *ifname, struct lyd_node
 
 static int bridge_gen_ports(struct dagger *net, struct lyd_node *dif, struct lyd_node *cif, FILE *ip)
 {
+	const char *ifname = lydx_get_cattr(cif, "name");
 	struct lyd_node *node, *bridge;
 	struct lydx_diff brdiff;
-	const char *ifname;
 	int err = 0;
 
 	if (!is_bridge_port(cif))
 		return 0;
 
 	node = lydx_get_descendant(lyd_child(dif), "bridge-port", NULL);
-	bridge = lydx_get_child(node, "bridge");
-	if (!node || !bridge)
-		return 0;	/* bridge port but no diff, skip */
+	if (!node)
+		goto fail;
 
-	ifname = lydx_get_cattr(cif, "name");
+	/*
+	 * If bridge is not in dif, then we only have bridge-port
+	 * settings and can use cif instead for any new settings
+	 * since we always set *all* port settings anyway.
+	 */
+	bridge = lydx_get_child(node, "bridge");
+	if (!bridge) {
+		struct lyd_node *pvid = lydx_get_child(node, "pvid");
+		struct lydx_diff pvidiff;
+		const char *brname;
+		FILE *next;
+
+		node = lydx_get_descendant(lyd_child(cif), "bridge-port", NULL);
+		brname = lydx_get_cattr(node, "bridge");
+		if (!node || !brname)
+			goto fail;
+
+		next = dagger_fopen_next(net, "init", ifname, 56, "init.ip");
+		if (!next) {
+			err = -EIO;
+			goto fail;
+		}
+		bridge_port_settings(next, ifname, cif);
+		fclose(next);
+
+		/* Change in bridge port's PVID => change in VLAN port memberships */
+		if (lydx_get_diff(pvid, &pvidiff))
+			bridge_port_vlans(net, cif, brname, ifname, &pvidiff);
+
+		err = dagger_add_dep(net, brname, ifname);
+		if (err)
+			return ERR_IFACE(cif, err, "Unable to add dep \"%s\" to %s", ifname, brdiff);
+		goto fail;
+	}
 
 	if (lydx_get_diff(bridge, &brdiff) && brdiff.old) {
 		FILE *prev;