net/dsa/tag.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * DSA tagging protocol handling
   4  *
   5  * Copyright (c) 2008-2009 Marvell Semiconductor
   6  * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
   7  * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
   8  */
   9
  10 #include <linux/netdevice.h>
  11 #include <linux/ptp_classify.h>
  12 #include <linux/skbuff.h>
  13 #include <net/dsa.h>
  14 #include <net/dst_metadata.h>
  15
  16 #include "tag.h"
  17 #include "user.h"
  18
  19 static LIST_HEAD(dsa_tag_drivers_list);
  20 static DEFINE_MUTEX(dsa_tag_drivers_lock);
  21
  22 /* Determine if we should defer delivery of skb until we have a rx timestamp.
  23  *
  24  * Called from dsa_switch_rcv. For now, this will only work if tagging is
  25  * enabled on the switch. Normally the MAC driver would retrieve the hardware
  26  * timestamp when it reads the packet out of the hardware. However in a DSA
  27  * switch, the DSA driver owning the interface to which the packet is
  28  * delivered is never notified unless we do so here.
  29  */
  30 static bool dsa_skb_defer_rx_timestamp(struct dsa_user_priv *p,
  31                                        struct sk_buff *skb)
  32 {
  33         struct dsa_switch *ds = p->dp->ds;
  34         unsigned int type;
  35
  36         if (!ds->ops->port_rxtstamp)
  37                 return false;
  38
  39         if (skb_headroom(skb) < ETH_HLEN)
  40                 return false;
  41
  42         __skb_push(skb, ETH_HLEN);
  43
  44         type = ptp_classify_raw(skb);
  45
  46         __skb_pull(skb, ETH_HLEN);
  47
  48         if (type == PTP_CLASS_NONE)
  49                 return false;
  50
  51         return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
  52 }
  53
  54 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
  55                           struct packet_type *pt, struct net_device *unused)
  56 {
  57         struct metadata_dst *md_dst = skb_metadata_dst(skb);
  58         struct dsa_port *cpu_dp = dev->dsa_ptr;
  59         struct sk_buff *nskb = NULL;
  60         struct dsa_user_priv *p;
  61
  62         if (unlikely(!cpu_dp)) {
  63                 kfree_skb(skb);
  64                 return 0;
  65         }
  66
  67         skb = skb_unshare(skb, GFP_ATOMIC);
  68         if (!skb)
  69                 return 0;
  70
  71         if (md_dst && md_dst->type == METADATA_HW_PORT_MUX) {
  72                 unsigned int port = md_dst->u.port_info.port_id;
  73
  74                 skb_dst_drop(skb);
  75                 if (!skb_has_extensions(skb))
  76                         skb->slow_gro = 0;
  77
  78                 skb->dev = dsa_conduit_find_user(dev, 0, port);
  79                 if (likely(skb->dev)) {
  80                         dsa_default_offload_fwd_mark(skb);
  81                         nskb = skb;
  82                 }
  83         } else {
  84                 nskb = cpu_dp->rcv(skb, dev);
  85         }
  86
  87         if (!nskb) {
  88                 kfree_skb(skb);
  89                 return 0;
  90         }
  91
  92         skb = nskb;
  93         skb_push(skb, ETH_HLEN);
  94         skb->pkt_type = PACKET_HOST;
  95         skb->protocol = eth_type_trans(skb, skb->dev);
  96
  97         if (unlikely(!dsa_user_dev_check(skb->dev))) {
  98                 /* Packet is to be injected directly on an upper
  99                  * device, e.g. a team/bond, so skip all DSA-port
 100                  * specific actions.
 101                  */
 102                 netif_rx(skb);
 103                 return 0;
 104         }
 105
 106         p = netdev_priv(skb->dev);
 107
 108         if (unlikely(cpu_dp->ds->untag_bridge_pvid ||
 109                      cpu_dp->ds->untag_vlan_aware_bridge_pvid)) {
 110                 nskb = dsa_software_vlan_untag(skb);
 111                 if (!nskb) {
 112                         kfree_skb(skb);
 113                         return 0;
 114                 }
 115                 skb = nskb;
 116         }
 117
 118         dev_sw_netstats_rx_add(skb->dev, skb->len + ETH_HLEN);
 119
 120         if (dsa_skb_defer_rx_timestamp(p, skb))
 121                 return 0;
 122
 123         gro_cells_receive(&p->gcells, skb);
 124
 125         return 0;
 126 }
 127
 128 struct packet_type dsa_pack_type __read_mostly = {
 129         .type   = cpu_to_be16(ETH_P_XDSA),
 130         .func   = dsa_switch_rcv,
 131 };
 132
 133 static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
 134                                     struct module *owner)
 135 {
 136         dsa_tag_driver->owner = owner;
 137
 138         mutex_lock(&dsa_tag_drivers_lock);
 139         list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
 140         mutex_unlock(&dsa_tag_drivers_lock);
 141 }
 142
 143 void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
 144                               unsigned int count, struct module *owner)
 145 {
 146         unsigned int i;
 147
 148         for (i = 0; i < count; i++)
 149                 dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
 150 }
 151
 152 static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
 153 {
 154         mutex_lock(&dsa_tag_drivers_lock);
 155         list_del(&dsa_tag_driver->list);
 156         mutex_unlock(&dsa_tag_drivers_lock);
 157 }
 158 EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
 159
 160 void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
 161                                 unsigned int count)
 162 {
 163         unsigned int i;
 164
 165         for (i = 0; i < count; i++)
 166                 dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
 167 }
 168 EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
 169
 170 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
 171 {
 172         return ops->name;
 173 };
 174
 175 /* Function takes a reference on the module owning the tagger,
 176  * so dsa_tag_driver_put must be called afterwards.
 177  */
 178 const struct dsa_device_ops *dsa_tag_driver_get_by_name(const char *name)
 179 {
 180         const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);
 181         struct dsa_tag_driver *dsa_tag_driver;
 182
 183         request_module("%s%s", DSA_TAG_DRIVER_ALIAS, name);
 184
 185         mutex_lock(&dsa_tag_drivers_lock);
 186         list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
 187                 const struct dsa_device_ops *tmp = dsa_tag_driver->ops;
 188
 189                 if (strcmp(name, tmp->name))
 190                         continue;
 191
 192                 if (!try_module_get(dsa_tag_driver->owner))
 193                         break;
 194
 195                 ops = tmp;
 196                 break;
 197         }
 198         mutex_unlock(&dsa_tag_drivers_lock);
 199
 200         return ops;
 201 }
 202
 203 const struct dsa_device_ops *dsa_tag_driver_get_by_id(int tag_protocol)
 204 {
 205         struct dsa_tag_driver *dsa_tag_driver;
 206         const struct dsa_device_ops *ops;
 207         bool found = false;
 208
 209         request_module("%sid-%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
 210
 211         mutex_lock(&dsa_tag_drivers_lock);
 212         list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
 213                 ops = dsa_tag_driver->ops;
 214                 if (ops->proto == tag_protocol) {
 215                         found = true;
 216                         break;
 217                 }
 218         }
 219
 220         if (found) {
 221                 if (!try_module_get(dsa_tag_driver->owner))
 222                         ops = ERR_PTR(-ENOPROTOOPT);
 223         } else {
 224                 ops = ERR_PTR(-ENOPROTOOPT);
 225         }
 226
 227         mutex_unlock(&dsa_tag_drivers_lock);
 228
 229         return ops;
 230 }
 231
 232 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
 233 {
 234         struct dsa_tag_driver *dsa_tag_driver;
 235
 236         mutex_lock(&dsa_tag_drivers_lock);
 237         list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
 238                 if (dsa_tag_driver->ops == ops) {
 239                         module_put(dsa_tag_driver->owner);
 240                         break;
 241                 }
 242         }
 243         mutex_unlock(&dsa_tag_drivers_lock);
 244 }