diff options
Diffstat (limited to 'net/dsa/tag_dsa.c')
| -rw-r--r-- | net/dsa/tag_dsa.c | 305 |
1 files changed, 246 insertions, 59 deletions
diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c index af340a4945dc..04646dd71c6c 100644 --- a/net/dsa/tag_dsa.c +++ b/net/dsa/tag_dsa.c @@ -1,7 +1,48 @@ // SPDX-License-Identifier: GPL-2.0+ /* - * net/dsa/tag_dsa.c - (Non-ethertype) DSA tagging + * Regular and Ethertype DSA tagging * Copyright (c) 2008-2009 Marvell Semiconductor + * + * Regular DSA + * ----------- + + * For untagged (in 802.1Q terms) packets, the switch will splice in + * the tag between the SA and the ethertype of the original + * packet. Tagged frames will instead have their outermost .1Q tag + * converted to a DSA tag. It expects the same layout when receiving + * packets from the CPU. + * + * Example: + * + * .----.----.----.--------- + * Pu: | DA | SA | ET | Payload ... + * '----'----'----'--------- + * 6 6 2 N + * .----.----.--------.-----.----.--------- + * Pt: | DA | SA | 0x8100 | TCI | ET | Payload ... + * '----'----'--------'-----'----'--------- + * 6 6 2 2 2 N + * .----.----.-----.----.--------- + * Pd: | DA | SA | DSA | ET | Payload ... + * '----'----'-----'----'--------- + * 6 6 4 2 N + * + * No matter if a packet is received untagged (Pu) or tagged (Pt), + * they will both have the same layout (Pd) when they are sent to the + * CPU. This is done by ignoring 802.3, replacing the ethertype field + * with more metadata, among which is a bit to signal if the original + * packet was tagged or not. + * + * Ethertype DSA + * ------------- + * Uses the exact same tag format as regular DSA, but also includes a + * proper ethertype field (which the mv88e6xxx driver sets to + * ETH_P_EDSA/0xdada) followed by two zero bytes: + * + * .----.----.--------.--------.-----.----.--------- + * | DA | SA | 0xdada | 0x0000 | DSA | ET | Payload ... + * '----'----'--------'--------'-----'----'--------- + * 6 6 2 2 4 2 N */ #include <linux/etherdevice.h> @@ -12,27 +53,92 @@ #define DSA_HLEN 4 -#define FRAME_TYPE_TO_CPU 0x00 -#define FRAME_TYPE_FORWARD 0x03 +/** + * enum dsa_cmd - DSA Command + * @DSA_CMD_TO_CPU: Set on packets that were trapped or mirrored to + * the CPU port. This is needed to implement control protocols, + * e.g. STP and LLDP, that must not allow those control packets to + * be switched according to the normal rules. + * @DSA_CMD_FROM_CPU: Used by the CPU to send a packet to a specific + * port, ignoring all the barriers that the switch normally + * enforces (VLANs, STP port states etc.). No source address + * learning takes place. "sudo send packet" + * @DSA_CMD_TO_SNIFFER: Set on the copies of packets that matched some + * user configured ingress or egress monitor criteria. These are + * forwarded by the switch tree to the user configured ingress or + * egress monitor port, which can be set to the CPU port or a + * regular port. If the destination is a regular port, the tag + * will be removed before egressing the port. If the destination + * is the CPU port, the tag will not be removed. + * @DSA_CMD_FORWARD: This tag is used on all bulk traffic passing + * through the switch tree, including the flows that are directed + * towards the CPU. Its device/port tuple encodes the original + * source port on which the packet ingressed. It can also be used + * on transmit by the CPU to defer the forwarding decision to the + * hardware, based on the current config of PVT/VTU/ATU + * etc. Source address learning takes places if enabled on the + * receiving DSA/CPU port. + */ +enum dsa_cmd { + DSA_CMD_TO_CPU = 0, + DSA_CMD_FROM_CPU = 1, + DSA_CMD_TO_SNIFFER = 2, + DSA_CMD_FORWARD = 3 +}; -#define TO_CPU_CODE_IGMP_MLD_TRAP 0x02 +/** + * enum dsa_code - TO_CPU Code + * + * @DSA_CODE_MGMT_TRAP: DA was classified as a management + * address. Typical examples include STP BPDUs and LLDP. + * @DSA_CODE_FRAME2REG: Response to a "remote management" request. + * @DSA_CODE_IGMP_MLD_TRAP: IGMP/MLD signaling. + * @DSA_CODE_POLICY_TRAP: Frame matched some policy configuration on + * the device. Typical examples are matching on DA/SA/VID and DHCP + * snooping. + * @DSA_CODE_ARP_MIRROR: The name says it all really. + * @DSA_CODE_POLICY_MIRROR: Same as @DSA_CODE_POLICY_TRAP, but the + * particular policy was set to trigger a mirror instead of a + * trap. + * @DSA_CODE_RESERVED_6: Unused on all devices up to at least 6393X. + * @DSA_CODE_RESERVED_7: Unused on all devices up to at least 6393X. + * + * A 3-bit code is used to relay why a particular frame was sent to + * the CPU. We only use this to determine if the packet was mirrored + * or trapped, i.e. whether the packet has been forwarded by hardware + * or not. + * + * This is the superset of all possible codes. Any particular device + * may only implement a subset. + */ +enum dsa_code { + DSA_CODE_MGMT_TRAP = 0, + DSA_CODE_FRAME2REG = 1, + DSA_CODE_IGMP_MLD_TRAP = 2, + DSA_CODE_POLICY_TRAP = 3, + DSA_CODE_ARP_MIRROR = 4, + DSA_CODE_POLICY_MIRROR = 5, + DSA_CODE_RESERVED_6 = 6, + DSA_CODE_RESERVED_7 = 7 +}; -static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev) +static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev, + u8 extra) { struct dsa_port *dp = dsa_slave_to_port(dev); u8 *dsa_header; - /* - * Convert the outermost 802.1q tag to a DSA tag for tagged - * packets, or insert a DSA tag between the addresses and - * the ethertype field for untagged packets. - */ if (skb->protocol == htons(ETH_P_8021Q)) { /* * Construct tagged FROM_CPU DSA tag from 802.1q tag. */ - dsa_header = skb->data + 2 * ETH_ALEN; - dsa_header[0] = 0x60 | dp->ds->index; + if (extra) { + skb_push(skb, extra); + memmove(skb->data, skb->data + extra, 2 * ETH_ALEN); + } + + dsa_header = skb->data + 2 * ETH_ALEN + extra; + dsa_header[0] = (DSA_CMD_FROM_CPU << 6) | 0x20 | dp->ds->index; dsa_header[1] = dp->index << 3; /* @@ -43,15 +149,14 @@ static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev) dsa_header[2] &= ~0x10; } } else { - skb_push(skb, DSA_HLEN); - - memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN); + skb_push(skb, DSA_HLEN + extra); + memmove(skb->data, skb->data + DSA_HLEN + extra, 2 * ETH_ALEN); /* * Construct untagged FROM_CPU DSA tag. */ - dsa_header = skb->data + 2 * ETH_ALEN; - dsa_header[0] = 0x40 | dp->ds->index; + dsa_header = skb->data + 2 * ETH_ALEN + extra; + dsa_header[0] = (DSA_CMD_FROM_CPU << 6) | dp->ds->index; dsa_header[1] = dp->index << 3; dsa_header[2] = 0x00; dsa_header[3] = 0x00; @@ -60,53 +165,62 @@ static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev) return skb; } -static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev, - struct packet_type *pt) +static struct sk_buff *dsa_rcv_ll(struct sk_buff *skb, struct net_device *dev, + u8 extra) { + int source_device, source_port; + enum dsa_code code; + enum dsa_cmd cmd; u8 *dsa_header; - int source_device; - int source_port; - int frame_type; - int code; - - if (unlikely(!pskb_may_pull(skb, DSA_HLEN))) - return NULL; /* * The ethertype field is part of the DSA header. */ dsa_header = skb->data - 2; - /* - * Check that frame type is either TO_CPU or FORWARD. - */ - frame_type = dsa_header[0] >> 6; + cmd = dsa_header[0] >> 6; + switch (cmd) { + case DSA_CMD_FORWARD: + skb->offload_fwd_mark = 1; + break; - switch (frame_type) { - case FRAME_TYPE_TO_CPU: + case DSA_CMD_TO_CPU: code = (dsa_header[1] & 0x6) | ((dsa_header[2] >> 4) & 1); - /* - * Mark the frame to never egress on any port of the same switch - * unless it's a trapped IGMP/MLD packet, in which case the - * bridge might want to forward it. - */ - if (code != TO_CPU_CODE_IGMP_MLD_TRAP) + switch (code) { + case DSA_CODE_FRAME2REG: + /* Remote management is not implemented yet, + * drop. + */ + return NULL; + case DSA_CODE_ARP_MIRROR: + case DSA_CODE_POLICY_MIRROR: + /* Mark mirrored packets to notify any upper + * device (like a bridge) that forwarding has + * already been done by hardware. + */ skb->offload_fwd_mark = 1; + break; + case DSA_CODE_MGMT_TRAP: + case DSA_CODE_IGMP_MLD_TRAP: + case DSA_CODE_POLICY_TRAP: + /* Traps have, by definition, not been + * forwarded by hardware, so don't mark them. + */ + break; + default: + /* Reserved code, this could be anything. Drop + * seems like the safest option. + */ + return NULL; + } break; - case FRAME_TYPE_FORWARD: - skb->offload_fwd_mark = 1; - break; - default: return NULL; } - /* - * Determine source device and port. - */ source_device = dsa_header[0] & 0x1f; source_port = (dsa_header[1] >> 3) & 0x1f; @@ -114,10 +228,10 @@ static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev, if (!skb->dev) return NULL; - /* - * Convert the DSA header to an 802.1q header if the 'tagged' - * bit in the DSA header is set. If the 'tagged' bit is clear, - * delete the DSA header entirely. + /* If the 'tagged' bit is set; convert the DSA tag to a 802.1Q + * tag, and delete the ethertype (extra) if applicable. If the + * 'tagged' bit is cleared; delete the DSA tag, and ethertype + * if applicable. */ if (dsa_header[0] & 0x20) { u8 new_header[4]; @@ -150,28 +264,101 @@ static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev, } memcpy(dsa_header, new_header, DSA_HLEN); + + if (extra) + memmove(skb->data - ETH_HLEN, + skb->data - ETH_HLEN - extra, + 2 * ETH_ALEN); } else { - /* - * Remove DSA tag and update checksum. - */ skb_pull_rcsum(skb, DSA_HLEN); memmove(skb->data - ETH_HLEN, - skb->data - ETH_HLEN - DSA_HLEN, + skb->data - ETH_HLEN - DSA_HLEN - extra, 2 * ETH_ALEN); } return skb; } +#if IS_ENABLED(CONFIG_NET_DSA_TAG_DSA) + +static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev) +{ + return dsa_xmit_ll(skb, dev, 0); +} + +static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt) +{ + if (unlikely(!pskb_may_pull(skb, DSA_HLEN))) + return NULL; + + return dsa_rcv_ll(skb, dev, 0); +} + static const struct dsa_device_ops dsa_netdev_ops = { - .name = "dsa", - .proto = DSA_TAG_PROTO_DSA, - .xmit = dsa_xmit, - .rcv = dsa_rcv, + .name = "dsa", + .proto = DSA_TAG_PROTO_DSA, + .xmit = dsa_xmit, + .rcv = dsa_rcv, .overhead = DSA_HLEN, }; -MODULE_LICENSE("GPL"); +DSA_TAG_DRIVER(dsa_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_DSA); +#endif /* CONFIG_NET_DSA_TAG_DSA */ + +#if IS_ENABLED(CONFIG_NET_DSA_TAG_EDSA) + +#define EDSA_HLEN 8 + +static struct sk_buff *edsa_xmit(struct sk_buff *skb, struct net_device *dev) +{ + u8 *edsa_header; + + skb = dsa_xmit_ll(skb, dev, EDSA_HLEN - DSA_HLEN); + if (!skb) + return NULL; -module_dsa_tag_driver(dsa_netdev_ops); + edsa_header = skb->data + 2 * ETH_ALEN; + edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff; + edsa_header[1] = ETH_P_EDSA & 0xff; + edsa_header[2] = 0x00; + edsa_header[3] = 0x00; + return skb; +} + +static struct sk_buff *edsa_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt) +{ + if (unlikely(!pskb_may_pull(skb, EDSA_HLEN))) + return NULL; + + skb_pull_rcsum(skb, EDSA_HLEN - DSA_HLEN); + + return dsa_rcv_ll(skb, dev, EDSA_HLEN - DSA_HLEN); +} + +static const struct dsa_device_ops edsa_netdev_ops = { + .name = "edsa", + .proto = DSA_TAG_PROTO_EDSA, + .xmit = edsa_xmit, + .rcv = edsa_rcv, + .overhead = EDSA_HLEN, +}; + +DSA_TAG_DRIVER(edsa_netdev_ops); +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_EDSA); +#endif /* CONFIG_NET_DSA_TAG_EDSA */ + +static struct dsa_tag_driver *dsa_tag_drivers[] = { +#if IS_ENABLED(CONFIG_NET_DSA_TAG_DSA) + &DSA_TAG_DRIVER_NAME(dsa_netdev_ops), +#endif +#if IS_ENABLED(CONFIG_NET_DSA_TAG_EDSA) + &DSA_TAG_DRIVER_NAME(edsa_netdev_ops), +#endif +}; + +module_dsa_tag_drivers(dsa_tag_drivers); + +MODULE_LICENSE("GPL"); |