commit 642c984dd0e37dbaec9f87bd1211e5fac1f142bf upstream.
Can now correctly identify where the packets should be delivered by using md_dst or its absence on devices that provide it.
This detection is not possible without device drivers that update md_dst. A fallback pattern should be used for supporting such device drivers. This fallback mode causes multicast messages to be cloned to both the non-macsec and macsec ports, independent of whether the multicast message received was encrypted over MACsec or not. Other non-macsec traffic may also fail to be handled correctly for devices in promiscuous mode.
Link: https://lore.kernel.org/netdev/ZULRxX9eIbFiVi7v@hog/ Cc: Sabrina Dubroca sd@queasysnail.net Cc: stable@vger.kernel.org Fixes: 860ead89b851 ("net/macsec: Add MACsec skb_metadata_dst Rx Data path support") Signed-off-by: Rahul Rameshbabu rrameshbabu@nvidia.com Reviewed-by: Benjamin Poirier bpoirier@nvidia.com Reviewed-by: Cosmin Ratiu cratiu@nvidia.com Reviewed-by: Sabrina Dubroca sd@queasysnail.net Link: https://lore.kernel.org/r/20240423181319.115860-4-rrameshbabu@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org --- drivers/net/macsec.c | 46 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 36 insertions(+), 10 deletions(-)
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index 9663050a852d..778fb77c5a93 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -996,10 +996,12 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb) struct metadata_dst *md_dst; struct macsec_rxh_data *rxd; struct macsec_dev *macsec; + bool is_macsec_md_dst;
rcu_read_lock(); rxd = macsec_data_rcu(skb->dev); md_dst = skb_metadata_dst(skb); + is_macsec_md_dst = md_dst && md_dst->type == METADATA_MACSEC;
list_for_each_entry_rcu(macsec, &rxd->secys, secys) { struct sk_buff *nskb; @@ -1010,14 +1012,42 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb) * the SecTAG, so we have to deduce which port to deliver to. */ if (macsec_is_offloaded(macsec) && netif_running(ndev)) { - struct macsec_rx_sc *rx_sc = NULL; + const struct macsec_ops *ops;
- if (md_dst && md_dst->type == METADATA_MACSEC) - rx_sc = find_rx_sc(&macsec->secy, md_dst->u.macsec_info.sci); + ops = macsec_get_ops(macsec, NULL);
- if (md_dst && md_dst->type == METADATA_MACSEC && !rx_sc) + if (ops->rx_uses_md_dst && !is_macsec_md_dst) continue;
+ if (is_macsec_md_dst) { + struct macsec_rx_sc *rx_sc; + + /* All drivers that implement MACsec offload + * support using skb metadata destinations must + * indicate that they do so. + */ + DEBUG_NET_WARN_ON_ONCE(!ops->rx_uses_md_dst); + rx_sc = find_rx_sc(&macsec->secy, + md_dst->u.macsec_info.sci); + if (!rx_sc) + continue; + /* device indicated macsec offload occurred */ + skb->dev = ndev; + skb->pkt_type = PACKET_HOST; + eth_skb_pkt_type(skb, ndev); + ret = RX_HANDLER_ANOTHER; + goto out; + } + + /* This datapath is insecure because it is unable to + * enforce isolation of broadcast/multicast traffic and + * unicast traffic with promiscuous mode on the macsec + * netdev. Since the core stack has no mechanism to + * check that the hardware did indeed receive MACsec + * traffic, it is possible that the response handling + * done by the MACsec port was to a plaintext packet. + * This violates the MACsec protocol standard. + */ if (ether_addr_equal_64bits(hdr->h_dest, ndev->dev_addr)) { /* exact match, divert skb to this port */ @@ -1033,14 +1063,10 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb) break;
nskb->dev = ndev; - if (ether_addr_equal_64bits(hdr->h_dest, - ndev->broadcast)) - nskb->pkt_type = PACKET_BROADCAST; - else - nskb->pkt_type = PACKET_MULTICAST; + eth_skb_pkt_type(nskb, ndev);
__netif_rx(nskb); - } else if (rx_sc || ndev->flags & IFF_PROMISC) { + } else if (ndev->flags & IFF_PROMISC) { skb->dev = ndev; skb->pkt_type = PACKET_HOST; ret = RX_HANDLER_ANOTHER;