bond: remove port from members on destroy

When deleting a port interface which is part of a bond, a dangling
pointer is left in the bond members array. This causes crashes when
destroying the bond:

  Program terminated with signal SIGSEGV, Segmentation fault.
  error reading variable: Cannot access memory at address 0xc
  Thread 1 (Thread 0x7f2f5cb51bc0 (LWP 657645)):
  #0  rte_arch_bswap16 at ../subprojects/dpdk/lib/eal/x86/include/rte_byteorder.h:30
  #1  bond_update_active_members at ../modules/infra/control/bond.c:248
  DPDK#2  gr_event_push at ../main/event.c:26
  DPDK#3  iface_destroy at ../modules/infra/control/iface.c:409
  DPDK#4  iface_del at ../modules/infra/api/iface.c:60

Make sure to remove the member when a port is deleted. Update the
primary index accordingly.

Signed-off-by: Robin Jarry <[email protected]>

Author: rjarry

modules/infra/control/bond.c

@@ -426,7 +426,7 @@ static struct iface_type iface_type_bond = {
 	.to_api = bond_to_api,
 };
 
-static void bond_event(uint32_t, const void *obj) {
+static void bond_event(uint32_t event, const void *obj) {
 	const struct iface_info_port *port;
 	const struct iface *iface = obj;
 	struct iface *b;
@@ -441,15 +441,41 @@ static void bond_event(uint32_t, const void *obj) {
 	b = iface_from_id(port->bond_iface_id);
 	if (b == NULL)
 		return;
-	assert(b->type == GR_IFACE_TYPE_BOND);
+
+	if (event == GR_EVENT_IFACE_PRE_REMOVE) {
+		// Remove port from bond
+		struct iface_info_bond *bond = iface_info_bond(b);
+		const struct iface *primary = bond->members[bond->primary_member].iface;
+
+		for (uint8_t i = 0; i < bond->n_members; i++) {
+			struct bond_member *member = &bond->members[i];
+			if (member->iface == iface && i != bond->n_members - 1) {
+				struct bond_member *next = &bond->members[i + 1];
+				memmove(member, next, sizeof(*next) * (bond->n_members - (i + 1)));
+				break;
+			}
+		}
+
+		bond->n_members--;
+		bond->primary_member = 0;
+
+		for (uint8_t i = 0; i < bond->n_members; i++) {
+			struct bond_member *member = &bond->members[i];
+			if (member->iface == primary) {
+				bond->primary_member = i;
+				break;
+			}
+		}
+	}
 
 	bond_update_active_members(b);
 }
 
 static struct gr_event_subscription bond_event_handler = {
 	.callback = bond_event,
-	.ev_count = 2,
+	.ev_count = 3,
 	.ev_types = {
+		GR_EVENT_IFACE_PRE_REMOVE,
 		GR_EVENT_IFACE_STATUS_UP,
 		GR_EVENT_IFACE_STATUS_DOWN,
 	},