^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * STP SAP demux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/etherdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/llc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <net/llc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <net/llc_pdu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <net/stp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) /* 01:80:c2:00:00:20 - 01:80:c2:00:00:2F */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #define GARP_ADDR_MIN 0x20
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #define GARP_ADDR_MAX 0x2F
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #define GARP_ADDR_RANGE (GARP_ADDR_MAX - GARP_ADDR_MIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) static const struct stp_proto __rcu *garp_protos[GARP_ADDR_RANGE + 1] __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) static const struct stp_proto __rcu *stp_proto __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static struct llc_sap *sap __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) static unsigned int sap_registered;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) static DEFINE_MUTEX(stp_proto_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) /* Called under rcu_read_lock from LLC */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) static int stp_pdu_rcv(struct sk_buff *skb, struct net_device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct packet_type *pt, struct net_device *orig_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) const struct ethhdr *eh = eth_hdr(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) const struct stp_proto *proto;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) if (pdu->ssap != LLC_SAP_BSPAN ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) pdu->dsap != LLC_SAP_BSPAN ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) pdu->ctrl_1 != LLC_PDU_TYPE_U)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) if (eh->h_dest[5] >= GARP_ADDR_MIN && eh->h_dest[5] <= GARP_ADDR_MAX) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) proto = rcu_dereference(garp_protos[eh->h_dest[5] -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) GARP_ADDR_MIN]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if (proto &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) !ether_addr_equal(eh->h_dest, proto->group_address))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) proto = rcu_dereference(stp_proto);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) if (!proto)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) proto->rcv(proto, skb, dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) int stp_proto_register(const struct stp_proto *proto)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) mutex_lock(&stp_proto_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) if (sap_registered++ == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) sap = llc_sap_open(LLC_SAP_BSPAN, stp_pdu_rcv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) if (!sap) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (is_zero_ether_addr(proto->group_address))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) rcu_assign_pointer(stp_proto, proto);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) rcu_assign_pointer(garp_protos[proto->group_address[5] -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) GARP_ADDR_MIN], proto);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) mutex_unlock(&stp_proto_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) EXPORT_SYMBOL_GPL(stp_proto_register);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) void stp_proto_unregister(const struct stp_proto *proto)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) mutex_lock(&stp_proto_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) if (is_zero_ether_addr(proto->group_address))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) RCU_INIT_POINTER(stp_proto, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) RCU_INIT_POINTER(garp_protos[proto->group_address[5] -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) GARP_ADDR_MIN], NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) synchronize_rcu();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) if (--sap_registered == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) llc_sap_put(sap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) mutex_unlock(&stp_proto_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) EXPORT_SYMBOL_GPL(stp_proto_unregister);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) MODULE_LICENSE("GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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