diff options
author | 2016-10-27 11:17:02 -0400 | |
---|---|---|
committer | 2016-10-27 17:29:10 +0000 | |
commit | 0fc9bc1206cd71da79c6cf22e1633eedde2eeeac (patch) | |
tree | 6bc7c9f2d529b4e5978d7e00fec62a09ce6c29fa /vnet | |
parent | 218170be70aee7e26e327392af9b637354c33b2a (diff) |
Fix potential L2 forwarding crash with stale L2FIB entry (VPP-516)
On moving interface between L2 and L3 forwarding modes, adjust the
l2-output node next index for the sw_if_index of the interface so
packet output via stale MAC entries in L2 FIB will be dropped.
Change-Id: I25afd7a617edb4ae35ce296bac33e62683edad9a
Signed-off-by: John Lo <loj@cisco.com>
Diffstat (limited to 'vnet')
-rw-r--r-- | vnet/vnet/l2/l2_input.c | 21 | ||||
-rw-r--r-- | vnet/vnet/l2/l2_output.c | 58 | ||||
-rw-r--r-- | vnet/vnet/l2/l2_output.h | 2 | ||||
-rw-r--r-- | vnet/vnet/vxlan/vxlan.c | 13 |
4 files changed, 44 insertions, 50 deletions
diff --git a/vnet/vnet/l2/l2_input.c b/vnet/vnet/l2/l2_input.c index 171ba734..9515250d 100644 --- a/vnet/vnet/l2/l2_input.c +++ b/vnet/vnet/l2/l2_input.c @@ -606,22 +606,29 @@ set_int_l2_mode (vlib_main_t * vm, vnet_main_t * vnet_main, u32 mode, u32 sw_if_ l2_if_adjust--; } + /* + * Directs the l2 output path to work out the interface + * output next-arc itself. Needed when recycling a sw_if_index. + */ + vec_validate_init_empty (l2om->next_nodes.output_node_index_vec, + sw_if_index, ~0); + l2om->next_nodes.output_node_index_vec[sw_if_index] = ~0; + /* Initialize the l2-input configuration for the interface */ if (mode == MODE_L3) { + /* Set L2 config to BD index 0 so that if any packet accidentally + * came in on L2 path, it will be dropped in BD 0 */ config->xconnect = 0; config->bridge = 0; config->shg = 0; config->bd_index = 0; config->feature_bitmap = L2INPUT_FEAT_DROP; - /* - * Directs the l2 output path to work out the interface - * output next-arc itself. Needed when recycling a sw_if_index. - */ - vec_validate_init_empty (l2om->next_nodes.output_node_index_vec, - sw_if_index, ~0); - l2om->next_nodes.output_node_index_vec[sw_if_index] = ~0; + /* Make sure any L2-output packet to this interface now in L3 mode is + * dropped. This may happen if L2 FIB MAC entry is stale */ + l2om->next_nodes.output_node_index_vec[sw_if_index] = + L2OUTPUT_NEXT_BAD_INTF; } else if (mode == MODE_L2_CLASSIFY) { diff --git a/vnet/vnet/l2/l2_output.c b/vnet/vnet/l2/l2_output.c index b84501aa..f8ebe146 100644 --- a/vnet/vnet/l2/l2_output.c +++ b/vnet/vnet/l2/l2_output.c @@ -469,46 +469,46 @@ VLIB_REGISTER_NODE (l2output_node,static) = { /* edit / add dispositions here */ .next_nodes = { [L2OUTPUT_NEXT_DROP] = "error-drop", - [L2OUTPUT_NEXT_DEL_TUNNEL] = "l2-output-del-tunnel", + [L2OUTPUT_NEXT_BAD_INTF] = "l2-output-bad-intf", }, }; /* *INDENT-ON* */ -#define foreach_l2output_del_tunnel_error \ -_(DROP, "L2 output to deleted tunnel") +#define foreach_l2output_bad_intf_error \ +_(DROP, "L2 output to interface not in L2 mode or deleted") -static char *l2output_del_tunnel_error_strings[] = { +static char *l2output_bad_intf_error_strings[] = { #define _(sym,string) string, - foreach_l2output_del_tunnel_error + foreach_l2output_bad_intf_error #undef _ }; typedef enum { -#define _(sym,str) L2OUTPUT_DEL_TUNNEL_ERROR_##sym, - foreach_l2output_del_tunnel_error +#define _(sym,str) L2OUTPUT_BAD_INTF_ERROR_##sym, + foreach_l2output_bad_intf_error #undef _ - L2OUTPUT_DEL_TUNNEL_N_ERROR, -} l2output_del_tunnel_error_t; + L2OUTPUT_BAD_INTF_N_ERROR, +} l2output_bad_intf_error_t; /** - * Output node for tunnels which was in L2 BD's but were deleted. - * On deletion of any tunnel which was on a L2 BD, its entry in - * l2_output_main table next_nodes.output_node_index_vec[sw_if_index] - * MUST be set to the value of L2OUTPUT_NEXT_DEL_TUNNEL. Thus, if there - * are stale entries in the L2FIB for this tunnel sw_if_index, l2-output - * will send packets for this sw_if_index to the l2-output-tunnel-del - * node which just setup the proper drop reason before sending packets - * to the error-drop node to drop the packet. Then, stale L2FIB entries - * for delted tunnels won't cause possible packet or memory corrpution. + * Output node for interfaces/tunnels which was in L2 mode but were changed + * to L3 mode or possibly deleted thereafter. On changing forwarding mode + * of any tunnel/interface from L2 to L3, its entry in l2_output_main table + * next_nodes.output_node_index_vec[sw_if_index] MUST be set to the value of + * L2OUTPUT_NEXT_BAD_INTF. Thus, if there are stale entries in the L2FIB for + * this sw_if_index, l2-output will send packets for this sw_if_index to the + * l2-output-bad-intf node which just setup the proper drop reason before + * sending packets to the error-drop node to drop the packet. Then, stale L2FIB + * entries for delted tunnels won't cause possible packet or memory corrpution. */ -static vlib_node_registration_t l2output_del_tunnel_node; +static vlib_node_registration_t l2output_bad_intf_node; static uword -l2output_del_tunnel_node_fn (vlib_main_t * vm, - vlib_node_runtime_t * node, vlib_frame_t * frame) +l2output_bad_intf_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 n_left_from, *from, *to_next; l2output_next_t next_index = 0; @@ -536,8 +536,8 @@ l2output_del_tunnel_node_fn (vlib_main_t * vm, n_left_to_next -= 2; b0 = vlib_get_buffer (vm, bi0); b1 = vlib_get_buffer (vm, bi1); - b0->error = node->errors[L2OUTPUT_DEL_TUNNEL_ERROR_DROP]; - b1->error = node->errors[L2OUTPUT_DEL_TUNNEL_ERROR_DROP]; + b0->error = node->errors[L2OUTPUT_BAD_INTF_ERROR_DROP]; + b1->error = node->errors[L2OUTPUT_BAD_INTF_ERROR_DROP]; } while (n_left_from > 0 && n_left_to_next > 0) @@ -552,7 +552,7 @@ l2output_del_tunnel_node_fn (vlib_main_t * vm, n_left_from -= 1; n_left_to_next -= 1; b0 = vlib_get_buffer (vm, bi0); - b0->error = node->errors[L2OUTPUT_DEL_TUNNEL_ERROR_DROP]; + b0->error = node->errors[L2OUTPUT_BAD_INTF_ERROR_DROP]; } vlib_put_next_frame (vm, node, next_index, n_left_to_next); @@ -562,14 +562,14 @@ l2output_del_tunnel_node_fn (vlib_main_t * vm, } /* *INDENT-OFF* */ -VLIB_REGISTER_NODE (l2output_del_tunnel_node,static) = { - .function = l2output_del_tunnel_node_fn, - .name = "l2-output-del-tunnel", +VLIB_REGISTER_NODE (l2output_bad_intf_node,static) = { + .function = l2output_bad_intf_node_fn, + .name = "l2-output-bad-intf", .vector_size = sizeof (u32), .type = VLIB_NODE_TYPE_INTERNAL, - .n_errors = ARRAY_LEN(l2output_del_tunnel_error_strings), - .error_strings = l2output_del_tunnel_error_strings, + .n_errors = ARRAY_LEN(l2output_bad_intf_error_strings), + .error_strings = l2output_bad_intf_error_strings, .n_next_nodes = 1, diff --git a/vnet/vnet/l2/l2_output.h b/vnet/vnet/l2/l2_output.h index 2e049148..c683b1ad 100644 --- a/vnet/vnet/l2/l2_output.h +++ b/vnet/vnet/l2/l2_output.h @@ -134,7 +134,7 @@ _(MAPPING_DROP, "L2 Output interface mapping in progress") typedef enum { L2OUTPUT_NEXT_DROP, - L2OUTPUT_NEXT_DEL_TUNNEL, + L2OUTPUT_NEXT_BAD_INTF, L2OUTPUT_N_NEXT, } l2output_next_t; diff --git a/vnet/vnet/vxlan/vxlan.c b/vnet/vnet/vxlan/vxlan.c index b90704aa..9ec4c741 100644 --- a/vnet/vnet/vxlan/vxlan.c +++ b/vnet/vnet/vxlan/vxlan.c @@ -214,7 +214,6 @@ int vnet_vxlan_add_del_tunnel int rv; vxlan4_tunnel_key_t key4; vxlan6_tunnel_key_t key6; - l2output_main_t * l2om = &l2output_main; if (!a->is_ip6) { key4.src = a->dst.ip4.as_u32; /* decap src in key is encap dst in config */ @@ -327,14 +326,6 @@ int vnet_vxlan_add_del_tunnel l2im->configs[sw_if_index].bd_index = 0; } - /* - * Directs the l2 output path to work out the interface - * output next-arc itself. Needed when recycling a tunnel. - */ - vec_validate_init_empty(l2om->next_nodes.output_node_index_vec, - sw_if_index, ~0); - l2om->next_nodes.output_node_index_vec[t->sw_if_index] - = ~0; vnet_sw_interface_set_flags (vnm, sw_if_index, VNET_SW_INTERFACE_FLAG_ADMIN_UP); if (!a->is_ip6) { @@ -362,10 +353,6 @@ int vnet_vxlan_add_del_tunnel vxm->tunnel_index_by_sw_if_index[t->sw_if_index] = ~0; - /* Directs the l2 path to turf packets sent to this sw_if_index */ - l2om->next_nodes.output_node_index_vec[t->sw_if_index] - = L2OUTPUT_NEXT_DEL_TUNNEL; - if (!a->is_ip6) { hash_unset (vxm->vxlan4_tunnel_by_key, key4.as_u64); |