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 | 44 +++++++++++++++++++++++++++++++++++++------- 1 file changed, 37 insertions(+), 7 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index 209ee9f35275..8a8fd74110e2 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -1007,10 +1007,12 @@ 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; @@ -1021,10 +1023,42 @@ 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)) { - if (md_dst && md_dst->type == METADATA_MACSEC && - (!find_rx_sc(&macsec->secy, md_dst->u.macsec_info.sci))) + const struct macsec_ops *ops; + + ops = macsec_get_ops(macsec, NULL); + + 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 */ @@ -1040,11 +1074,7 @@ 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); }

On Mon, Apr 29, 2024 at 05:44:21PM -0700, Rahul Rameshbabu wrote:

commit 475747a19316b08e856c666a20503e73d7ed67ed upstream.

Omit rx_use_md_dst comment in upstream commit since macsec_ops is not documented.

Cannot know whether a Rx skb missing md_dst is intended for MACsec or not without knowing whether the device is able to update this field during an offload. Assume that an offload to a MACsec device cannot support updating md_dst by default. Capable devices can advertise that they do indicate that an skb is related to a MACsec offloaded packet using the md_dst.

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/20240423181319.115860-2-rrameshbabu@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org

---

include/net/macsec.h | 1 + 1 file changed, 1 insertion(+)

diff --git a/include/net/macsec.h b/include/net/macsec.h index 65c93959c2dc..dd578d193f9a 100644 --- a/include/net/macsec.h +++ b/include/net/macsec.h @@ -302,6 +302,7 @@ struct macsec_ops { int (*mdo_get_tx_sa_stats)(struct macsec_context *ctx); int (*mdo_get_rx_sc_stats)(struct macsec_context *ctx); int (*mdo_get_rx_sa_stats)(struct macsec_context *ctx);

• bool rx_uses_md_dst;

}; void macsec_pn_wrapped(struct macsec_secy *secy, struct macsec_tx_sa *tx_sa); -- 2.42.0

All backports now queued up, thanks!

greg k-h