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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 | /* * Spanning tree protocol; BPDU handling * Linux ethernet bridge * * Authors: * Lennert Buytenhek <buytenh@gnu.org> * * $Id: br_stp_bpdu.c,v 1.2 2000/02/21 15:51:34 davem Exp $ * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/kernel.h> #include <linux/if_bridge.h> #include "br_private.h" #include "br_private_stp.h" #define JIFFIES_TO_TICKS(j) (((j) << 8) / HZ) #define TICKS_TO_JIFFIES(j) (((j) * HZ) >> 8) static void br_send_bpdu(struct net_bridge_port *p, unsigned char *data, int length) { struct net_device *dev; struct sk_buff *skb; int size; if (!p->br->stp_enabled) return; size = length + 2*ETH_ALEN + 2; if (size < 60) size = 60; dev = p->dev; if ((skb = dev_alloc_skb(size)) == NULL) { printk(KERN_INFO "br: memory squeeze!\n"); return; } skb->dev = dev; skb->mac.raw = skb_put(skb, size); memcpy(skb->mac.raw, bridge_ula, ETH_ALEN); memcpy(skb->mac.raw+ETH_ALEN, dev->dev_addr, ETH_ALEN); skb->mac.raw[2*ETH_ALEN] = 0; skb->mac.raw[2*ETH_ALEN+1] = length; skb->nh.raw = skb->mac.raw + 2*ETH_ALEN + 2; memcpy(skb->nh.raw, data, length); memset(skb->nh.raw + length, 0xa5, size - length - 2*ETH_ALEN - 2); dev_queue_xmit(skb); } static __inline__ void br_set_ticks(unsigned char *dest, int jiff) { __u16 ticks; ticks = JIFFIES_TO_TICKS(jiff); dest[0] = (ticks >> 8) & 0xFF; dest[1] = ticks & 0xFF; } static __inline__ int br_get_ticks(unsigned char *dest) { return TICKS_TO_JIFFIES((dest[0] << 8) | dest[1]); } /* called under bridge lock */ void br_send_config_bpdu(struct net_bridge_port *p, struct br_config_bpdu *bpdu) { unsigned char buf[38]; buf[0] = 0x42; buf[1] = 0x42; buf[2] = 0x03; buf[3] = 0; buf[4] = 0; buf[5] = 0; buf[6] = BPDU_TYPE_CONFIG; buf[7] = (bpdu->topology_change ? 0x01 : 0) | (bpdu->topology_change_ack ? 0x80 : 0); buf[8] = bpdu->root.prio[0]; buf[9] = bpdu->root.prio[1]; buf[10] = bpdu->root.addr[0]; buf[11] = bpdu->root.addr[1]; buf[12] = bpdu->root.addr[2]; buf[13] = bpdu->root.addr[3]; buf[14] = bpdu->root.addr[4]; buf[15] = bpdu->root.addr[5]; buf[16] = (bpdu->root_path_cost >> 24) & 0xFF; buf[17] = (bpdu->root_path_cost >> 16) & 0xFF; buf[18] = (bpdu->root_path_cost >> 8) & 0xFF; buf[19] = bpdu->root_path_cost & 0xFF; buf[20] = bpdu->bridge_id.prio[0]; buf[21] = bpdu->bridge_id.prio[1]; buf[22] = bpdu->bridge_id.addr[0]; buf[23] = bpdu->bridge_id.addr[1]; buf[24] = bpdu->bridge_id.addr[2]; buf[25] = bpdu->bridge_id.addr[3]; buf[26] = bpdu->bridge_id.addr[4]; buf[27] = bpdu->bridge_id.addr[5]; buf[28] = (bpdu->port_id >> 8) & 0xFF; buf[29] = bpdu->port_id & 0xFF; br_set_ticks(buf+30, bpdu->message_age); br_set_ticks(buf+32, bpdu->max_age); br_set_ticks(buf+34, bpdu->hello_time); br_set_ticks(buf+36, bpdu->forward_delay); br_send_bpdu(p, buf, 38); } /* called under bridge lock */ void br_send_tcn_bpdu(struct net_bridge_port *p) { unsigned char buf[7]; buf[0] = 0x42; buf[1] = 0x42; buf[2] = 0x03; buf[3] = 0; buf[4] = 0; buf[5] = 0; buf[6] = BPDU_TYPE_TCN; br_send_bpdu(p, buf, 7); } static unsigned char header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00}; /* called under bridge lock */ void br_stp_handle_bpdu(struct sk_buff *skb) { unsigned char *buf; struct net_bridge_port *p; buf = skb->mac.raw + 14; p = skb->dev->br_port; if (!p->br->stp_enabled || memcmp(buf, header, 6)) { kfree_skb(skb); return; } if (buf[6] == BPDU_TYPE_CONFIG) { struct br_config_bpdu bpdu; bpdu.topology_change = (buf[7] & 0x01) ? 1 : 0; bpdu.topology_change_ack = (buf[7] & 0x80) ? 1 : 0; bpdu.root.prio[0] = buf[8]; bpdu.root.prio[1] = buf[9]; bpdu.root.addr[0] = buf[10]; bpdu.root.addr[1] = buf[11]; bpdu.root.addr[2] = buf[12]; bpdu.root.addr[3] = buf[13]; bpdu.root.addr[4] = buf[14]; bpdu.root.addr[5] = buf[15]; bpdu.root_path_cost = (buf[16] << 24) | (buf[17] << 16) | (buf[18] << 8) | buf[19]; bpdu.bridge_id.prio[0] = buf[20]; bpdu.bridge_id.prio[1] = buf[21]; bpdu.bridge_id.addr[0] = buf[22]; bpdu.bridge_id.addr[1] = buf[23]; bpdu.bridge_id.addr[2] = buf[24]; bpdu.bridge_id.addr[3] = buf[25]; bpdu.bridge_id.addr[4] = buf[26]; bpdu.bridge_id.addr[5] = buf[27]; bpdu.port_id = (buf[28] << 8) | buf[29]; bpdu.message_age = br_get_ticks(buf+30); bpdu.max_age = br_get_ticks(buf+32); bpdu.hello_time = br_get_ticks(buf+34); bpdu.forward_delay = br_get_ticks(buf+36); kfree_skb(skb); br_received_config_bpdu(p, &bpdu); return; } if (buf[6] == BPDU_TYPE_TCN) { br_received_tcn_bpdu(p); kfree_skb(skb); return; } kfree_skb(skb); } |