Andrew Lunn | 5beef3c | 2009-11-09 21:20:10 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2007-2009 B.A.T.M.A.N. contributors: |
| 3 | * |
| 4 | * Marek Lindner, Simon Wunderlich |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of version 2 of the GNU General Public |
| 8 | * License as published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 18 | * 02110-1301, USA |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include "main.h" |
| 23 | #include "aggregation.h" |
| 24 | #include "send.h" |
| 25 | #include "routing.h" |
| 26 | |
| 27 | /* calculate the size of the hna information for a given packet */ |
| 28 | static int hna_len(struct batman_packet *batman_packet) |
| 29 | { |
| 30 | return batman_packet->num_hna * ETH_ALEN; |
| 31 | } |
| 32 | |
| 33 | /* return true if new_packet can be aggregated with forw_packet */ |
| 34 | static bool can_aggregate_with(struct batman_packet *new_batman_packet, |
| 35 | int packet_len, |
| 36 | unsigned long send_time, |
| 37 | bool directlink, |
| 38 | struct batman_if *if_incoming, |
| 39 | struct forw_packet *forw_packet) |
| 40 | { |
| 41 | struct batman_packet *batman_packet = |
| 42 | (struct batman_packet *)forw_packet->packet_buff; |
| 43 | int aggregated_bytes = forw_packet->packet_len + packet_len; |
| 44 | |
| 45 | /** |
| 46 | * we can aggregate the current packet to this aggregated packet |
| 47 | * if: |
| 48 | * |
| 49 | * - the send time is within our MAX_AGGREGATION_MS time |
| 50 | * - the resulting packet wont be bigger than |
| 51 | * MAX_AGGREGATION_BYTES |
| 52 | */ |
| 53 | |
| 54 | if (time_before(send_time, forw_packet->send_time) && |
| 55 | (aggregated_bytes <= MAX_AGGREGATION_BYTES)) { |
| 56 | |
| 57 | /** |
| 58 | * check aggregation compatibility |
| 59 | * -> direct link packets are broadcasted on |
| 60 | * their interface only |
| 61 | * -> aggregate packet if the current packet is |
| 62 | * a "global" packet as well as the base |
| 63 | * packet |
| 64 | */ |
| 65 | |
| 66 | /* packets without direct link flag and high TTL |
| 67 | * are flooded through the net */ |
| 68 | if ((!directlink) && |
| 69 | (!(batman_packet->flags & DIRECTLINK)) && |
| 70 | (batman_packet->ttl != 1) && |
| 71 | |
| 72 | /* own packets originating non-primary |
| 73 | * interfaces leave only that interface */ |
| 74 | ((!forw_packet->own) || |
| 75 | (forw_packet->if_incoming->if_num == 0))) |
| 76 | return true; |
| 77 | |
| 78 | /* if the incoming packet is sent via this one |
| 79 | * interface only - we still can aggregate */ |
| 80 | if ((directlink) && |
| 81 | (new_batman_packet->ttl == 1) && |
| 82 | (forw_packet->if_incoming == if_incoming)) |
| 83 | return true; |
| 84 | |
| 85 | } |
| 86 | |
| 87 | return false; |
| 88 | } |
| 89 | |
| 90 | /* create a new aggregated packet and add this packet to it */ |
| 91 | static void new_aggregated_packet(unsigned char *packet_buff, |
| 92 | int packet_len, |
| 93 | unsigned long send_time, |
| 94 | bool direct_link, |
| 95 | struct batman_if *if_incoming, |
| 96 | int own_packet) |
| 97 | { |
| 98 | struct forw_packet *forw_packet_aggr; |
| 99 | |
| 100 | forw_packet_aggr = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC); |
| 101 | if (!forw_packet_aggr) |
| 102 | return; |
| 103 | |
| 104 | forw_packet_aggr->packet_buff = kmalloc(MAX_AGGREGATION_BYTES, |
| 105 | GFP_ATOMIC); |
| 106 | if (!forw_packet_aggr->packet_buff) { |
| 107 | kfree(forw_packet_aggr); |
| 108 | return; |
| 109 | } |
| 110 | |
| 111 | INIT_HLIST_NODE(&forw_packet_aggr->list); |
| 112 | |
| 113 | forw_packet_aggr->packet_len = packet_len; |
| 114 | memcpy(forw_packet_aggr->packet_buff, |
| 115 | packet_buff, |
| 116 | forw_packet_aggr->packet_len); |
| 117 | |
| 118 | forw_packet_aggr->own = own_packet; |
| 119 | forw_packet_aggr->if_incoming = if_incoming; |
| 120 | forw_packet_aggr->num_packets = 0; |
| 121 | forw_packet_aggr->direct_link_flags = 0; |
| 122 | forw_packet_aggr->send_time = send_time; |
| 123 | |
| 124 | /* save packet direct link flag status */ |
| 125 | if (direct_link) |
| 126 | forw_packet_aggr->direct_link_flags |= 1; |
| 127 | |
| 128 | /* add new packet to packet list */ |
| 129 | spin_lock(&forw_bat_list_lock); |
| 130 | hlist_add_head(&forw_packet_aggr->list, &forw_bat_list); |
| 131 | spin_unlock(&forw_bat_list_lock); |
| 132 | |
| 133 | /* start timer for this packet */ |
| 134 | INIT_DELAYED_WORK(&forw_packet_aggr->delayed_work, |
| 135 | send_outstanding_bat_packet); |
| 136 | queue_delayed_work(bat_event_workqueue, |
| 137 | &forw_packet_aggr->delayed_work, |
| 138 | send_time - jiffies); |
| 139 | } |
| 140 | |
| 141 | /* aggregate a new packet into the existing aggregation */ |
| 142 | static void aggregate(struct forw_packet *forw_packet_aggr, |
| 143 | unsigned char *packet_buff, |
| 144 | int packet_len, |
| 145 | bool direct_link) |
| 146 | { |
| 147 | memcpy((forw_packet_aggr->packet_buff + forw_packet_aggr->packet_len), |
| 148 | packet_buff, packet_len); |
| 149 | forw_packet_aggr->packet_len += packet_len; |
| 150 | forw_packet_aggr->num_packets++; |
| 151 | |
| 152 | /* save packet direct link flag status */ |
| 153 | if (direct_link) |
| 154 | forw_packet_aggr->direct_link_flags |= |
| 155 | (1 << forw_packet_aggr->num_packets); |
| 156 | } |
| 157 | |
| 158 | void add_bat_packet_to_list(unsigned char *packet_buff, int packet_len, |
| 159 | struct batman_if *if_incoming, char own_packet, |
| 160 | unsigned long send_time) |
| 161 | { |
| 162 | /** |
| 163 | * _aggr -> pointer to the packet we want to aggregate with |
| 164 | * _pos -> pointer to the position in the queue |
| 165 | */ |
| 166 | struct forw_packet *forw_packet_aggr = NULL, *forw_packet_pos = NULL; |
| 167 | struct hlist_node *tmp_node; |
| 168 | struct batman_packet *batman_packet = |
| 169 | (struct batman_packet *)packet_buff; |
| 170 | bool direct_link = batman_packet->flags & DIRECTLINK ? 1 : 0; |
| 171 | |
| 172 | /* find position for the packet in the forward queue */ |
| 173 | spin_lock(&forw_bat_list_lock); |
| 174 | /* own packets are not to be aggregated */ |
| 175 | if ((atomic_read(&aggregation_enabled)) && (!own_packet)) { |
| 176 | hlist_for_each_entry(forw_packet_pos, tmp_node, &forw_bat_list, |
| 177 | list) { |
| 178 | if (can_aggregate_with(batman_packet, |
| 179 | packet_len, |
| 180 | send_time, |
| 181 | direct_link, |
| 182 | if_incoming, |
| 183 | forw_packet_pos)) { |
| 184 | forw_packet_aggr = forw_packet_pos; |
| 185 | break; |
| 186 | } |
| 187 | } |
| 188 | } |
| 189 | |
| 190 | /* nothing to aggregate with - either aggregation disabled or no |
| 191 | * suitable aggregation packet found */ |
| 192 | if (forw_packet_aggr == NULL) { |
| 193 | /* the following section can run without the lock */ |
| 194 | spin_unlock(&forw_bat_list_lock); |
| 195 | new_aggregated_packet(packet_buff, packet_len, |
| 196 | send_time, direct_link, |
| 197 | if_incoming, own_packet); |
| 198 | } else { |
| 199 | aggregate(forw_packet_aggr, |
| 200 | packet_buff, packet_len, |
| 201 | direct_link); |
| 202 | spin_unlock(&forw_bat_list_lock); |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | /* unpack the aggregated packets and process them one by one */ |
| 207 | void receive_aggr_bat_packet(struct ethhdr *ethhdr, unsigned char *packet_buff, |
| 208 | int packet_len, struct batman_if *if_incoming) |
| 209 | { |
| 210 | struct batman_packet *batman_packet; |
| 211 | int buff_pos = 0; |
| 212 | unsigned char *hna_buff; |
| 213 | |
| 214 | batman_packet = (struct batman_packet *)packet_buff; |
| 215 | |
| 216 | while (aggregated_packet(buff_pos, packet_len, |
| 217 | batman_packet->num_hna)) { |
| 218 | |
| 219 | /* network to host order for our 16bit seqno, and the |
| 220 | orig_interval. */ |
| 221 | batman_packet->seqno = ntohs(batman_packet->seqno); |
| 222 | |
| 223 | hna_buff = packet_buff + buff_pos + BAT_PACKET_LEN; |
| 224 | receive_bat_packet(ethhdr, batman_packet, |
| 225 | hna_buff, hna_len(batman_packet), |
| 226 | if_incoming); |
| 227 | |
| 228 | buff_pos += BAT_PACKET_LEN + hna_len(batman_packet); |
| 229 | batman_packet = (struct batman_packet *) |
| 230 | (packet_buff + buff_pos); |
| 231 | } |
| 232 | } |