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| | 1 | /* Copyright (C) 2012-2016 B.A.T.M.A.N. contributors: |
| | 2 | * |
| | 3 | * Edo Monticelli, Antonio Quartulli |
| | 4 | * |
| | 5 | * This program is free software; you can redistribute it and/or |
| | 6 | * modify it under the terms of version 2 of the GNU General Public |
| | 7 | * License as published by the Free Software Foundation. |
| | 8 | * |
| | 9 | * This program is distributed in the hope that it will be useful, but |
| | 10 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| | 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| | 12 | * General Public License for more details. |
| | 13 | * |
| | 14 | * You should have received a copy of the GNU General Public License |
| | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| | 16 | */ |
| | 17 | |
| | 18 | #include "tp_meter.h" |
| | 19 | #include "main.h" |
| | 20 | |
| | 21 | #include <linux/atomic.h> |
| | 22 | #include <linux/bug.h> |
| | 23 | #include <linux/byteorder/generic.h> |
| | 24 | #include <linux/cache.h> |
| | 25 | #include <linux/compiler.h> |
| | 26 | #include <linux/device.h> |
| | 27 | #include <linux/etherdevice.h> |
| | 28 | #include <linux/fs.h> |
| | 29 | #include <linux/if_ether.h> |
| | 30 | #include <linux/jiffies.h> |
| | 31 | #include <linux/kernel.h> |
| | 32 | #include <linux/kref.h> |
| | 33 | #include <linux/kthread.h> |
| | 34 | #include <linux/list.h> |
| | 35 | #include <linux/netdevice.h> |
| | 36 | #include <linux/param.h> |
| | 37 | #include <linux/printk.h> |
| | 38 | #include <linux/random.h> |
| | 39 | #include <linux/rculist.h> |
| | 40 | #include <linux/rcupdate.h> |
| | 41 | #include <linux/sched.h> |
| | 42 | #include <linux/skbuff.h> |
| | 43 | #include <linux/slab.h> |
| | 44 | #include <linux/spinlock.h> |
| | 45 | #include <linux/stddef.h> |
| | 46 | #include <linux/string.h> |
| | 47 | #include <linux/timer.h> |
| | 48 | #include <linux/wait.h> |
| | 49 | #include <linux/workqueue.h> |
| | 50 | #include <uapi/linux/batman_adv.h> |
| | 51 | |
| | 52 | #include "hard-interface.h" |
| | 53 | #include "log.h" |
| | 54 | #include "netlink.h" |
| | 55 | #include "originator.h" |
| | 56 | #include "packet.h" |
| | 57 | #include "send.h" |
| | 58 | |
| | 59 | /** |
| | 60 | * BATADV_TP_DEF_TEST_LENGTH - Default test length if not specified by the user |
| | 61 | * in milliseconds |
| | 62 | */ |
| | 63 | #define BATADV_TP_DEF_TEST_LENGTH 10000 |
| | 64 | |
| | 65 | /** |
| | 66 | * BATADV_TP_AWND - Advertised window by the receiver (in bytes) |
| | 67 | */ |
| | 68 | #define BATADV_TP_AWND 0x20000000 |
| | 69 | |
| | 70 | /** |
| | 71 | * BATADV_TP_RECV_TIMEOUT - Receiver activity timeout. If the receiver does not |
| | 72 | * get anything for such amount of milliseconds, the connection is killed |
| | 73 | */ |
| | 74 | #define BATADV_TP_RECV_TIMEOUT 1000 |
| | 75 | |
| | 76 | /** |
| | 77 | * BATADV_TP_MAX_RTO - Maximum sender timeout. If the sender RTO gets beyond |
| | 78 | * such amound of milliseconds, the receiver is considered unreachable and the |
| | 79 | * connection is killed |
| | 80 | */ |
| | 81 | #define BATADV_TP_MAX_RTO 30000 |
| | 82 | |
| | 83 | /** |
| | 84 | * BATADV_TP_FIRST_SEQ - First seqno of each session. The number is rather high |
| | 85 | * in order to immediately trigger a wrap around (test purposes) |
| | 86 | */ |
| | 87 | #define BATADV_TP_FIRST_SEQ ((u32)-1 - 2000) |
| | 88 | |
| | 89 | /** |
| | 90 | * BATADV_TP_PLEN - length of the payload (data after the batadv_unicast header) |
| | 91 | * to simulate |
| | 92 | */ |
| | 93 | #define BATADV_TP_PLEN (BATADV_TP_PACKET_LEN - ETH_HLEN - \ |
| | 94 | sizeof(struct batadv_unicast_packet)) |
| | 95 | |
| | 96 | static u8 batadv_tp_prerandom[4096] __read_mostly; |
| | 97 | |
| | 98 | /** |
| | 99 | * batadv_tp_session_cookie - generate session cookie based on session ids |
| | 100 | * @session: TP session identifier |
| | 101 | * @icmp_uid: icmp pseudo uid of the tp session |
| | 102 | * |
| | 103 | * Return: 32 bit tp_meter session cookie |
| | 104 | */ |
| | 105 | static u32 batadv_tp_session_cookie(const u8 session[2], u8 icmp_uid) |
| | 106 | { |
| | 107 | u32 cookie; |
| | 108 | |
| | 109 | cookie = icmp_uid << 16; |
| | 110 | cookie |= session[0] << 8; |
| | 111 | cookie |= session[1]; |
| | 112 | |
| | 113 | return cookie; |
| | 114 | } |
| | 115 | |
| | 116 | /** |
| | 117 | * batadv_tp_cwnd - compute the new cwnd size |
| | 118 | * @base: base cwnd size value |
| | 119 | * @increment: the value to add to base to get the new size |
| | 120 | * @min: minumim cwnd value (usually MSS) |
| | 121 | * |
| | 122 | * Return the new cwnd size and ensures it does not exceed the Advertised |
| | 123 | * Receiver Window size. It is wrap around safe. |
| | 124 | * For details refer to Section 3.1 of RFC5681 |
| | 125 | * |
| | 126 | * Return: new congestion window size in bytes |
| | 127 | */ |
| | 128 | static u32 batadv_tp_cwnd(u32 base, u32 increment, u32 min) |
| | 129 | { |
| | 130 | u32 new_size = base + increment; |
| | 131 | |
| | 132 | /* check for wrap-around */ |
| | 133 | if (new_size < base) |
| | 134 | new_size = (u32)ULONG_MAX; |
| | 135 | |
| | 136 | new_size = min_t(u32, new_size, BATADV_TP_AWND); |
| | 137 | |
| | 138 | return max_t(u32, new_size, min); |
| | 139 | } |
| | 140 | |
| | 141 | /** |
| | 142 | * batadv_tp_updated_cwnd - update the Congestion Windows |
| | 143 | * @tp_vars: the private data of the current TP meter session |
| | 144 | * @mss: maximum segment size of transmission |
| | 145 | * |
| | 146 | * 1) if the session is in Slow Start, the CWND has to be increased by 1 |
| | 147 | * MSS every unique received ACK |
| | 148 | * 2) if the session is in Congestion Avoidance, the CWND has to be |
| | 149 | * increased by MSS * MSS / CWND for every unique received ACK |
| | 150 | */ |
| | 151 | static void batadv_tp_update_cwnd(struct batadv_tp_vars *tp_vars, u32 mss) |
| | 152 | { |
| | 153 | spin_lock_bh(&tp_vars->cwnd_lock); |
| | 154 | |
| | 155 | /* slow start... */ |
| | 156 | if (tp_vars->cwnd <= tp_vars->ss_threshold) { |
| | 157 | tp_vars->dec_cwnd = 0; |
| | 158 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss); |
| | 159 | spin_unlock_bh(&tp_vars->cwnd_lock); |
| | 160 | return; |
| | 161 | } |
| | 162 | |
| | 163 | /* increment CWND at least of 1 (section 3.1 of RFC5681) */ |
| | 164 | tp_vars->dec_cwnd += max_t(u32, 1U << 3, |
| | 165 | ((mss * mss) << 6) / (tp_vars->cwnd << 3)); |
| | 166 | if (tp_vars->dec_cwnd < (mss << 3)) { |
| | 167 | spin_unlock_bh(&tp_vars->cwnd_lock); |
| | 168 | return; |
| | 169 | } |
| | 170 | |
| | 171 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss); |
| | 172 | tp_vars->dec_cwnd = 0; |
| | 173 | |
| | 174 | spin_unlock_bh(&tp_vars->cwnd_lock); |
| | 175 | } |
| | 176 | |
| | 177 | /** |
| | 178 | * batadv_tp_update_rto - calculate new retransmission timeout |
| | 179 | * @tp_vars: the private data of the current TP meter session |
| | 180 | * @new_rtt: new roundtrip time in msec |
| | 181 | */ |
| | 182 | static void batadv_tp_update_rto(struct batadv_tp_vars *tp_vars, |
| | 183 | u32 new_rtt) |
| | 184 | { |
| | 185 | long m = new_rtt; |
| | 186 | |
| | 187 | /* RTT update |
| | 188 | * Details in Section 2.2 and 2.3 of RFC6298 |
| | 189 | * |
| | 190 | * It's tricky to understand. Don't lose hair please. |
| | 191 | * Inspired by tcp_rtt_estimator() tcp_input.c |
| | 192 | */ |
| | 193 | if (tp_vars->srtt != 0) { |
| | 194 | m -= (tp_vars->srtt >> 3); /* m is now error in rtt est */ |
| | 195 | tp_vars->srtt += m; /* rtt = 7/8 srtt + 1/8 new */ |
| | 196 | if (m < 0) |
| | 197 | m = -m; |
| | 198 | |
| | 199 | m -= (tp_vars->rttvar >> 2); |
| | 200 | tp_vars->rttvar += m; /* mdev ~= 3/4 rttvar + 1/4 new */ |
| | 201 | } else { |
| | 202 | /* first measure getting in */ |
| | 203 | tp_vars->srtt = m << 3; /* take the measured time to be srtt */ |
| | 204 | tp_vars->rttvar = m << 1; /* new_rtt / 2 */ |
| | 205 | } |
| | 206 | |
| | 207 | /* rto = srtt + 4 * rttvar. |
| | 208 | * rttvar is scaled by 4, therefore doesn't need to be multiplied |
| | 209 | */ |
| | 210 | tp_vars->rto = (tp_vars->srtt >> 3) + tp_vars->rttvar; |
| | 211 | } |
| | 212 | |
| | 213 | /** |
| | 214 | * batadv_tp_batctl_notify - send client status result to client |
| | 215 | * @reason: reason for tp meter session stop |
| | 216 | * @dst: destination of tp_meter session |
| | 217 | * @bat_priv: the bat priv with all the soft interface information |
| | 218 | * @start_time: start of transmission in jiffies |
| | 219 | * @total_sent: bytes acked to the receiver |
| | 220 | * @cookie: cookie of tp_meter session |
| | 221 | */ |
| | 222 | static void batadv_tp_batctl_notify(enum batadv_tp_meter_reason reason, |
| | 223 | const u8 *dst, struct batadv_priv *bat_priv, |
| | 224 | unsigned long start_time, u64 total_sent, |
| | 225 | u32 cookie) |
| | 226 | { |
| | 227 | u32 test_time; |
| | 228 | u8 result; |
| | 229 | u32 total_bytes; |
| | 230 | |
| | 231 | if (!batadv_tp_is_error(reason)) { |
| | 232 | result = BATADV_TP_REASON_COMPLETE; |
| | 233 | test_time = jiffies_to_msecs(jiffies - start_time); |
| | 234 | total_bytes = total_sent; |
| | 235 | } else { |
| | 236 | result = reason; |
| | 237 | test_time = 0; |
| | 238 | total_bytes = 0; |
| | 239 | } |
| | 240 | |
| | 241 | batadv_netlink_tpmeter_notify(bat_priv, dst, result, test_time, |
| | 242 | total_bytes, cookie); |
| | 243 | } |
| | 244 | |
| | 245 | /** |
| | 246 | * batadv_tp_batctl_error_notify - send client error result to client |
| | 247 | * @reason: reason for tp meter session stop |
| | 248 | * @dst: destination of tp_meter session |
| | 249 | * @bat_priv: the bat priv with all the soft interface information |
| | 250 | * @cookie: cookie of tp_meter session |
| | 251 | */ |
| | 252 | static void batadv_tp_batctl_error_notify(enum batadv_tp_meter_reason reason, |
| | 253 | const u8 *dst, |
| | 254 | struct batadv_priv *bat_priv, |
| | 255 | u32 cookie) |
| | 256 | { |
| | 257 | batadv_tp_batctl_notify(reason, dst, bat_priv, 0, 0, cookie); |
| | 258 | } |
| | 259 | |
| | 260 | /** |
| | 261 | * batadv_tp_list_find - find a tp_vars object in the global list |
| | 262 | * @bat_priv: the bat priv with all the soft interface information |
| | 263 | * @dst: the other endpoint MAC address to look for |
| | 264 | * |
| | 265 | * Look for a tp_vars object matching dst as end_point and return it after |
| | 266 | * having incremented the refcounter. Return NULL is not found |
| | 267 | * |
| | 268 | * Return: matching tp_vars or NULL when no tp_vars with @dst was found |
| | 269 | */ |
| | 270 | static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv, |
| | 271 | const u8 *dst) |
| | 272 | { |
| | 273 | struct batadv_tp_vars *pos, *tp_vars = NULL; |
| | 274 | |
| | 275 | rcu_read_lock(); |
| | 276 | hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) { |
| | 277 | if (!batadv_compare_eth(pos->other_end, dst)) |
| | 278 | continue; |
| | 279 | |
| | 280 | /* most of the time this function is invoked during the normal |
| | 281 | * process..it makes sens to pay more when the session is |
| | 282 | * finished and to speed the process up during the measurement |
| | 283 | */ |
| | 284 | if (unlikely(!kref_get_unless_zero(&pos->refcount))) |
| | 285 | continue; |
| | 286 | |
| | 287 | tp_vars = pos; |
| | 288 | break; |
| | 289 | } |
| | 290 | rcu_read_unlock(); |
| | 291 | |
| | 292 | return tp_vars; |
| | 293 | } |
| | 294 | |
| | 295 | /** |
| | 296 | * batadv_tp_list_find_session - find tp_vars session object in the global list |
| | 297 | * @bat_priv: the bat priv with all the soft interface information |
| | 298 | * @dst: the other endpoint MAC address to look for |
| | 299 | * @session: session identifier |
| | 300 | * |
| | 301 | * Look for a tp_vars object matching dst as end_point, session as tp meter |
| | 302 | * session and return it after having incremented the refcounter. Return NULL |
| | 303 | * is not found |
| | 304 | * |
| | 305 | * Return: matching tp_vars or NULL when no tp_vars was found |
| | 306 | */ |
| | 307 | static struct batadv_tp_vars * |
| | 308 | batadv_tp_list_find_session(struct batadv_priv *bat_priv, const u8 *dst, |
| | 309 | const u8 *session) |
| | 310 | { |
| | 311 | struct batadv_tp_vars *pos, *tp_vars = NULL; |
| | 312 | |
| | 313 | rcu_read_lock(); |
| | 314 | hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) { |
| | 315 | if (!batadv_compare_eth(pos->other_end, dst)) |
| | 316 | continue; |
| | 317 | |
| | 318 | if (memcmp(pos->session, session, sizeof(pos->session)) != 0) |
| | 319 | continue; |
| | 320 | |
| | 321 | /* most of the time this function is invoked during the normal |
| | 322 | * process..it makes sense to pay more when the session is |
| | 323 | * finished and to speed the process up during the measurement |
| | 324 | */ |
| | 325 | if (unlikely(!kref_get_unless_zero(&pos->refcount))) |
| | 326 | continue; |
| | 327 | |
| | 328 | tp_vars = pos; |
| | 329 | break; |
| | 330 | } |
| | 331 | rcu_read_unlock(); |
| | 332 | |
| | 333 | return tp_vars; |
| | 334 | } |
| | 335 | |
| | 336 | /** |
| | 337 | * batadv_tp_vars_release - release batadv_tp_vars from lists and queue for |
| | 338 | * free after rcu grace period |
| | 339 | * @ref: kref pointer of the batadv_tp_vars |
| | 340 | */ |
| | 341 | static void batadv_tp_vars_release(struct kref *ref) |
| | 342 | { |
| | 343 | struct batadv_tp_vars *tp_vars; |
| | 344 | struct batadv_tp_unacked *un, *safe; |
| | 345 | |
| | 346 | tp_vars = container_of(ref, struct batadv_tp_vars, refcount); |
| | 347 | |
| | 348 | /* lock should not be needed because this object is now out of any |
| | 349 | * context! |
| | 350 | */ |
| | 351 | spin_lock_bh(&tp_vars->unacked_lock); |
| | 352 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { |
| | 353 | list_del(&un->list); |
| | 354 | kfree(un); |
| | 355 | } |
| | 356 | spin_unlock_bh(&tp_vars->unacked_lock); |
| | 357 | |
| | 358 | kfree_rcu(tp_vars, rcu); |
| | 359 | } |
| | 360 | |
| | 361 | /** |
| | 362 | * batadv_tp_vars_put - decrement the batadv_tp_vars refcounter and possibly |
| | 363 | * release it |
| | 364 | * @tp_vars: the private data of the current TP meter session to be free'd |
| | 365 | */ |
| | 366 | static void batadv_tp_vars_put(struct batadv_tp_vars *tp_vars) |
| | 367 | { |
| | 368 | kref_put(&tp_vars->refcount, batadv_tp_vars_release); |
| | 369 | } |
| | 370 | |
| | 371 | /** |
| | 372 | * batadv_tp_sender_cleanup - cleanup sender data and drop and timer |
| | 373 | * @bat_priv: the bat priv with all the soft interface information |
| | 374 | * @tp_vars: the private data of the current TP meter session to cleanup |
| | 375 | */ |
| | 376 | static void batadv_tp_sender_cleanup(struct batadv_priv *bat_priv, |
| | 377 | struct batadv_tp_vars *tp_vars) |
| | 378 | { |
| | 379 | cancel_delayed_work(&tp_vars->finish_work); |
| | 380 | |
| | 381 | spin_lock_bh(&tp_vars->bat_priv->tp_list_lock); |
| | 382 | hlist_del_rcu(&tp_vars->list); |
| | 383 | spin_unlock_bh(&tp_vars->bat_priv->tp_list_lock); |
| | 384 | |
| | 385 | /* drop list reference */ |
| | 386 | batadv_tp_vars_put(tp_vars); |
| | 387 | |
| | 388 | atomic_dec(&tp_vars->bat_priv->tp_num); |
| | 389 | |
| | 390 | /* kill the timer and remove its reference */ |
| | 391 | del_timer_sync(&tp_vars->timer); |
| | 392 | /* the worker might have rearmed itself therefore we kill it again. Note |
| | 393 | * that if the worker should run again before invoking the following |
| | 394 | * del_timer(), it would not re-arm itself once again because the status |
| | 395 | * is OFF now |
| | 396 | */ |
| | 397 | del_timer(&tp_vars->timer); |
| | 398 | batadv_tp_vars_put(tp_vars); |
| | 399 | } |
| | 400 | |
| | 401 | /** |
| | 402 | * batadv_tp_sender_end - print info about ended session and inform client |
| | 403 | * @bat_priv: the bat priv with all the soft interface information |
| | 404 | * @tp_vars: the private data of the current TP meter session |
| | 405 | */ |
| | 406 | static void batadv_tp_sender_end(struct batadv_priv *bat_priv, |
| | 407 | struct batadv_tp_vars *tp_vars) |
| | 408 | { |
| | 409 | u32 session_cookie; |
| | 410 | |
| | 411 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 412 | "Test towards %pM finished..shutting down (reason=%d)\n", |
| | 413 | tp_vars->other_end, tp_vars->reason); |
| | 414 | |
| | 415 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 416 | "Last timing stats: SRTT=%ums RTTVAR=%ums RTO=%ums\n", |
| | 417 | tp_vars->srtt >> 3, tp_vars->rttvar >> 2, tp_vars->rto); |
| | 418 | |
| | 419 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 420 | "Final values: cwnd=%u ss_threshold=%u\n", |
| | 421 | tp_vars->cwnd, tp_vars->ss_threshold); |
| | 422 | |
| | 423 | session_cookie = batadv_tp_session_cookie(tp_vars->session, |
| | 424 | tp_vars->icmp_uid); |
| | 425 | |
| | 426 | batadv_tp_batctl_notify(tp_vars->reason, |
| | 427 | tp_vars->other_end, |
| | 428 | bat_priv, |
| | 429 | tp_vars->start_time, |
| | 430 | atomic64_read(&tp_vars->tot_sent), |
| | 431 | session_cookie); |
| | 432 | } |
| | 433 | |
| | 434 | /** |
| | 435 | * batadv_tp_sender_shutdown - let sender thread/timer stop gracefully |
| | 436 | * @tp_vars: the private data of the current TP meter session |
| | 437 | * @reason: reason for tp meter session stop |
| | 438 | */ |
| | 439 | static void batadv_tp_sender_shutdown(struct batadv_tp_vars *tp_vars, |
| | 440 | enum batadv_tp_meter_reason reason) |
| | 441 | { |
| | 442 | if (!atomic_dec_and_test(&tp_vars->sending)) |
| | 443 | return; |
| | 444 | |
| | 445 | tp_vars->reason = reason; |
| | 446 | } |
| | 447 | |
| | 448 | /** |
| | 449 | * batadv_tp_sender_finish - stop sender session after test_length was reached |
| | 450 | * @work: delayed work reference of the related tp_vars |
| | 451 | */ |
| | 452 | static void batadv_tp_sender_finish(struct work_struct *work) |
| | 453 | { |
| | 454 | struct delayed_work *delayed_work; |
| | 455 | struct batadv_tp_vars *tp_vars; |
| | 456 | |
| | 457 | delayed_work = to_delayed_work(work); |
| | 458 | tp_vars = container_of(delayed_work, struct batadv_tp_vars, |
| | 459 | finish_work); |
| | 460 | |
| | 461 | batadv_tp_sender_shutdown(tp_vars, BATADV_TP_REASON_COMPLETE); |
| | 462 | } |
| | 463 | |
| | 464 | /** |
| | 465 | * batadv_tp_reset_sender_timer - reschedule the sender timer |
| | 466 | * @tp_vars: the private TP meter data for this session |
| | 467 | * |
| | 468 | * Reschedule the timer using tp_vars->rto as delay |
| | 469 | */ |
| | 470 | static void batadv_tp_reset_sender_timer(struct batadv_tp_vars *tp_vars) |
| | 471 | { |
| | 472 | /* most of the time this function is invoked while normal packet |
| | 473 | * reception... |
| | 474 | */ |
| | 475 | if (unlikely(atomic_read(&tp_vars->sending) == 0)) |
| | 476 | /* timer ref will be dropped in batadv_tp_sender_cleanup */ |
| | 477 | return; |
| | 478 | |
| | 479 | mod_timer(&tp_vars->timer, jiffies + msecs_to_jiffies(tp_vars->rto)); |
| | 480 | } |
| | 481 | |
| | 482 | /** |
| | 483 | * batadv_tp_sender_timeout - timer that fires in case of packet loss |
| | 484 | * @arg: address of the related tp_vars |
| | 485 | * |
| | 486 | * If fired it means that there was packet loss. |
| | 487 | * Switch to Slow Start, set the ss_threshold to half of the current cwnd and |
| | 488 | * reset the cwnd to 3*MSS |
| | 489 | */ |
| | 490 | static void batadv_tp_sender_timeout(unsigned long arg) |
| | 491 | { |
| | 492 | struct batadv_tp_vars *tp_vars = (struct batadv_tp_vars *)arg; |
| | 493 | struct batadv_priv *bat_priv = tp_vars->bat_priv; |
| | 494 | |
| | 495 | if (atomic_read(&tp_vars->sending) == 0) |
| | 496 | return; |
| | 497 | |
| | 498 | /* if the user waited long enough...shutdown the test */ |
| | 499 | if (unlikely(tp_vars->rto >= BATADV_TP_MAX_RTO)) { |
| | 500 | batadv_tp_sender_shutdown(tp_vars, |
| | 501 | BATADV_TP_REASON_DST_UNREACHABLE); |
| | 502 | return; |
| | 503 | } |
| | 504 | |
| | 505 | /* RTO exponential backoff |
| | 506 | * Details in Section 5.5 of RFC6298 |
| | 507 | */ |
| | 508 | tp_vars->rto <<= 1; |
| | 509 | |
| | 510 | spin_lock_bh(&tp_vars->cwnd_lock); |
| | 511 | |
| | 512 | tp_vars->ss_threshold = tp_vars->cwnd >> 1; |
| | 513 | if (tp_vars->ss_threshold < BATADV_TP_PLEN * 2) |
| | 514 | tp_vars->ss_threshold = BATADV_TP_PLEN * 2; |
| | 515 | |
| | 516 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 517 | "Meter: RTO fired during test towards %pM! cwnd=%u new ss_thr=%u, resetting last_sent to %u\n", |
| | 518 | tp_vars->other_end, tp_vars->cwnd, tp_vars->ss_threshold, |
| | 519 | atomic_read(&tp_vars->last_acked)); |
| | 520 | |
| | 521 | tp_vars->cwnd = BATADV_TP_PLEN * 3; |
| | 522 | |
| | 523 | spin_unlock_bh(&tp_vars->cwnd_lock); |
| | 524 | |
| | 525 | /* resend the non-ACKed packets.. */ |
| | 526 | tp_vars->last_sent = atomic_read(&tp_vars->last_acked); |
| | 527 | wake_up(&tp_vars->more_bytes); |
| | 528 | |
| | 529 | batadv_tp_reset_sender_timer(tp_vars); |
| | 530 | } |
| | 531 | |
| | 532 | /** |
| | 533 | * batadv_tp_fill_prerandom - Fill buffer with prefetched random bytes |
| | 534 | * @tp_vars: the private TP meter data for this session |
| | 535 | * @buf: Buffer to fill with bytes |
| | 536 | * @nbytes: amount of pseudorandom bytes |
| | 537 | */ |
| | 538 | static void batadv_tp_fill_prerandom(struct batadv_tp_vars *tp_vars, |
| | 539 | u8 *buf, size_t nbytes) |
| | 540 | { |
| | 541 | u32 local_offset; |
| | 542 | size_t bytes_inbuf; |
| | 543 | size_t to_copy; |
| | 544 | size_t pos = 0; |
| | 545 | |
| | 546 | spin_lock_bh(&tp_vars->prerandom_lock); |
| | 547 | local_offset = tp_vars->prerandom_offset; |
| | 548 | tp_vars->prerandom_offset += nbytes; |
| | 549 | tp_vars->prerandom_offset %= sizeof(batadv_tp_prerandom); |
| | 550 | spin_unlock_bh(&tp_vars->prerandom_lock); |
| | 551 | |
| | 552 | while (nbytes) { |
| | 553 | local_offset %= sizeof(batadv_tp_prerandom); |
| | 554 | bytes_inbuf = sizeof(batadv_tp_prerandom) - local_offset; |
| | 555 | to_copy = min(nbytes, bytes_inbuf); |
| | 556 | |
| | 557 | memcpy(&buf[pos], &batadv_tp_prerandom[local_offset], to_copy); |
| | 558 | pos += to_copy; |
| | 559 | nbytes -= to_copy; |
| | 560 | local_offset = 0; |
| | 561 | } |
| | 562 | } |
| | 563 | |
| | 564 | /** |
| | 565 | * batadv_tp_send_msg - send a single message |
| | 566 | * @tp_vars: the private TP meter data for this session |
| | 567 | * @src: source mac address |
| | 568 | * @orig_node: the originator of the destination |
| | 569 | * @seqno: sequence number of this packet |
| | 570 | * @len: length of the entire packet |
| | 571 | * @session: session identifier |
| | 572 | * @uid: local ICMP "socket" index |
| | 573 | * @timestamp: timestamp in jiffies which is replied in ack |
| | 574 | * |
| | 575 | * Create and send a single TP Meter message. |
| | 576 | * |
| | 577 | * Return: 0 on success, BATADV_TP_REASON_DST_UNREACHABLE if the destination is |
| | 578 | * not reachable, BATADV_TP_REASON_MEMORY_ERROR if the packet couldn't be |
| | 579 | * allocated |
| | 580 | */ |
| | 581 | static int batadv_tp_send_msg(struct batadv_tp_vars *tp_vars, const u8 *src, |
| | 582 | struct batadv_orig_node *orig_node, |
| | 583 | u32 seqno, size_t len, const u8 *session, |
| | 584 | int uid, u32 timestamp) |
| | 585 | { |
| | 586 | struct batadv_icmp_tp_packet *icmp; |
| | 587 | struct sk_buff *skb; |
| | 588 | int r; |
| | 589 | u8 *data; |
| | 590 | size_t data_len; |
| | 591 | |
| | 592 | skb = netdev_alloc_skb_ip_align(NULL, len + ETH_HLEN); |
| | 593 | if (unlikely(!skb)) |
| | 594 | return BATADV_TP_REASON_MEMORY_ERROR; |
| | 595 | |
| | 596 | skb_reserve(skb, ETH_HLEN); |
| | 597 | icmp = (struct batadv_icmp_tp_packet *)skb_put(skb, sizeof(*icmp)); |
| | 598 | |
| | 599 | /* fill the icmp header */ |
| | 600 | ether_addr_copy(icmp->dst, orig_node->orig); |
| | 601 | ether_addr_copy(icmp->orig, src); |
| | 602 | icmp->version = BATADV_COMPAT_VERSION; |
| | 603 | icmp->packet_type = BATADV_ICMP; |
| | 604 | icmp->ttl = BATADV_TTL; |
| | 605 | icmp->msg_type = BATADV_TP; |
| | 606 | icmp->uid = uid; |
| | 607 | |
| | 608 | icmp->subtype = BATADV_TP_MSG; |
| | 609 | memcpy(icmp->session, session, sizeof(icmp->session)); |
| | 610 | icmp->seqno = htonl(seqno); |
| | 611 | icmp->timestamp = htonl(timestamp); |
| | 612 | |
| | 613 | data_len = len - sizeof(*icmp); |
| | 614 | data = (u8 *)skb_put(skb, data_len); |
| | 615 | batadv_tp_fill_prerandom(tp_vars, data, data_len); |
| | 616 | |
| | 617 | r = batadv_send_skb_to_orig(skb, orig_node, NULL); |
| | 618 | if (r == -1) |
| | 619 | kfree_skb(skb); |
| | 620 | |
| | 621 | if (r == NET_XMIT_SUCCESS) |
| | 622 | return 0; |
| | 623 | |
| | 624 | return BATADV_TP_REASON_CANT_SEND; |
| | 625 | } |
| | 626 | |
| | 627 | /** |
| | 628 | * batadv_tp_recv_ack - ACK receiving function |
| | 629 | * @bat_priv: the bat priv with all the soft interface information |
| | 630 | * @skb: the buffer containing the received packet |
| | 631 | * |
| | 632 | * Process a received TP ACK packet |
| | 633 | */ |
| | 634 | static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, |
| | 635 | const struct sk_buff *skb) |
| | 636 | { |
| | 637 | struct batadv_hard_iface *primary_if = NULL; |
| | 638 | struct batadv_orig_node *orig_node = NULL; |
| | 639 | const struct batadv_icmp_tp_packet *icmp; |
| | 640 | struct batadv_tp_vars *tp_vars; |
| | 641 | size_t packet_len, mss; |
| | 642 | u32 rtt, recv_ack, cwnd; |
| | 643 | unsigned char *dev_addr; |
| | 644 | |
| | 645 | packet_len = BATADV_TP_PLEN; |
| | 646 | mss = BATADV_TP_PLEN; |
| | 647 | packet_len += sizeof(struct batadv_unicast_packet); |
| | 648 | |
| | 649 | icmp = (struct batadv_icmp_tp_packet *)skb->data; |
| | 650 | |
| | 651 | /* find the tp_vars */ |
| | 652 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, |
| | 653 | icmp->session); |
| | 654 | if (unlikely(!tp_vars)) |
| | 655 | return; |
| | 656 | |
| | 657 | if (unlikely(atomic_read(&tp_vars->sending) == 0)) |
| | 658 | goto out; |
| | 659 | |
| | 660 | /* old ACK? silently drop it.. */ |
| | 661 | if (batadv_seq_before(ntohl(icmp->seqno), |
| | 662 | (u32)atomic_read(&tp_vars->last_acked))) |
| | 663 | goto out; |
| | 664 | |
| | 665 | primary_if = batadv_primary_if_get_selected(bat_priv); |
| | 666 | if (unlikely(!primary_if)) |
| | 667 | goto out; |
| | 668 | |
| | 669 | orig_node = batadv_orig_hash_find(bat_priv, icmp->orig); |
| | 670 | if (unlikely(!orig_node)) |
| | 671 | goto out; |
| | 672 | |
| | 673 | /* update RTO with the new sampled RTT, if any */ |
| | 674 | rtt = jiffies_to_msecs(jiffies) - ntohl(icmp->timestamp); |
| | 675 | if (icmp->timestamp && rtt) |
| | 676 | batadv_tp_update_rto(tp_vars, rtt); |
| | 677 | |
| | 678 | /* ACK for new data... reset the timer */ |
| | 679 | batadv_tp_reset_sender_timer(tp_vars); |
| | 680 | |
| | 681 | recv_ack = ntohl(icmp->seqno); |
| | 682 | |
| | 683 | /* check if this ACK is a duplicate */ |
| | 684 | if (atomic_read(&tp_vars->last_acked) == recv_ack) { |
| | 685 | atomic_inc(&tp_vars->dup_acks); |
| | 686 | if (atomic_read(&tp_vars->dup_acks) != 3) |
| | 687 | goto out; |
| | 688 | |
| | 689 | if (recv_ack >= tp_vars->recover) |
| | 690 | goto out; |
| | 691 | |
| | 692 | /* if this is the third duplicate ACK do Fast Retransmit */ |
| | 693 | batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr, |
| | 694 | orig_node, recv_ack, packet_len, |
| | 695 | icmp->session, icmp->uid, |
| | 696 | jiffies_to_msecs(jiffies)); |
| | 697 | |
| | 698 | spin_lock_bh(&tp_vars->cwnd_lock); |
| | 699 | |
| | 700 | /* Fast Recovery */ |
| | 701 | tp_vars->fast_recovery = true; |
| | 702 | /* Set recover to the last outstanding seqno when Fast Recovery |
| | 703 | * is entered. RFC6582, Section 3.2, step 1 |
| | 704 | */ |
| | 705 | tp_vars->recover = tp_vars->last_sent; |
| | 706 | tp_vars->ss_threshold = tp_vars->cwnd >> 1; |
| | 707 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 708 | "Meter: Fast Recovery, (cur cwnd=%u) ss_thr=%u last_sent=%u recv_ack=%u\n", |
| | 709 | tp_vars->cwnd, tp_vars->ss_threshold, |
| | 710 | tp_vars->last_sent, recv_ack); |
| | 711 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->ss_threshold, 3 * mss, |
| | 712 | mss); |
| | 713 | tp_vars->dec_cwnd = 0; |
| | 714 | tp_vars->last_sent = recv_ack; |
| | 715 | |
| | 716 | spin_unlock_bh(&tp_vars->cwnd_lock); |
| | 717 | } else { |
| | 718 | /* count the acked data */ |
| | 719 | atomic64_add(recv_ack - atomic_read(&tp_vars->last_acked), |
| | 720 | &tp_vars->tot_sent); |
| | 721 | /* reset the duplicate ACKs counter */ |
| | 722 | atomic_set(&tp_vars->dup_acks, 0); |
| | 723 | |
| | 724 | if (tp_vars->fast_recovery) { |
| | 725 | /* partial ACK */ |
| | 726 | if (batadv_seq_before(recv_ack, tp_vars->recover)) { |
| | 727 | /* this is another hole in the window. React |
| | 728 | * immediately as specified by NewReno (see |
| | 729 | * Section 3.2 of RFC6582 for details) |
| | 730 | */ |
| | 731 | dev_addr = primary_if->net_dev->dev_addr; |
| | 732 | batadv_tp_send_msg(tp_vars, dev_addr, |
| | 733 | orig_node, recv_ack, |
| | 734 | packet_len, icmp->session, |
| | 735 | icmp->uid, |
| | 736 | jiffies_to_msecs(jiffies)); |
| | 737 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, |
| | 738 | mss, mss); |
| | 739 | } else { |
| | 740 | tp_vars->fast_recovery = false; |
| | 741 | /* set cwnd to the value of ss_threshold at the |
| | 742 | * moment that Fast Recovery was entered. |
| | 743 | * RFC6582, Section 3.2, step 3 |
| | 744 | */ |
| | 745 | cwnd = batadv_tp_cwnd(tp_vars->ss_threshold, 0, |
| | 746 | mss); |
| | 747 | tp_vars->cwnd = cwnd; |
| | 748 | } |
| | 749 | goto move_twnd; |
| | 750 | } |
| | 751 | |
| | 752 | if (recv_ack - atomic_read(&tp_vars->last_acked) >= mss) |
| | 753 | batadv_tp_update_cwnd(tp_vars, mss); |
| | 754 | move_twnd: |
| | 755 | /* move the Transmit Window */ |
| | 756 | atomic_set(&tp_vars->last_acked, recv_ack); |
| | 757 | } |
| | 758 | |
| | 759 | wake_up(&tp_vars->more_bytes); |
| | 760 | out: |
| | 761 | if (likely(primary_if)) |
| | 762 | batadv_hardif_put(primary_if); |
| | 763 | if (likely(orig_node)) |
| | 764 | batadv_orig_node_put(orig_node); |
| | 765 | if (likely(tp_vars)) |
| | 766 | batadv_tp_vars_put(tp_vars); |
| | 767 | } |
| | 768 | |
| | 769 | /** |
| | 770 | * batadv_tp_avail - check if congestion window is not full |
| | 771 | * @tp_vars: the private data of the current TP meter session |
| | 772 | * @payload_len: size of the payload of a single message |
| | 773 | * |
| | 774 | * Return: true when congestion window is not full, false otherwise |
| | 775 | */ |
| | 776 | static bool batadv_tp_avail(struct batadv_tp_vars *tp_vars, |
| | 777 | size_t payload_len) |
| | 778 | { |
| | 779 | u32 win_left, win_limit; |
| | 780 | |
| | 781 | win_limit = atomic_read(&tp_vars->last_acked) + tp_vars->cwnd; |
| | 782 | win_left = win_limit - tp_vars->last_sent; |
| | 783 | |
| | 784 | return win_left >= payload_len; |
| | 785 | } |
| | 786 | |
| | 787 | /** |
| | 788 | * batadv_tp_wait_available - wait until congestion window becomes free or |
| | 789 | * timeout is reached |
| | 790 | * @tp_vars: the private data of the current TP meter session |
| | 791 | * @plen: size of the payload of a single message |
| | 792 | * |
| | 793 | * Return: 0 if the condition evaluated to false after the timeout elapsed, |
| | 794 | * 1 if the condition evaluated to true after the timeout elapsed, the |
| | 795 | * remaining jiffies (at least 1) if the condition evaluated to true before |
| | 796 | * the timeout elapsed, or -ERESTARTSYS if it was interrupted by a signal. |
| | 797 | */ |
| | 798 | static int batadv_tp_wait_available(struct batadv_tp_vars *tp_vars, size_t plen) |
| | 799 | { |
| | 800 | int ret; |
| | 801 | |
| | 802 | ret = wait_event_interruptible_timeout(tp_vars->more_bytes, |
| | 803 | batadv_tp_avail(tp_vars, plen), |
| | 804 | HZ / 10); |
| | 805 | |
| | 806 | return ret; |
| | 807 | } |
| | 808 | |
| | 809 | /** |
| | 810 | * batadv_tp_send - main sending thread of a tp meter session |
| | 811 | * @arg: address of the related tp_vars |
| | 812 | * |
| | 813 | * Return: nothing, this function never returns |
| | 814 | */ |
| | 815 | static int batadv_tp_send(void *arg) |
| | 816 | { |
| | 817 | struct batadv_tp_vars *tp_vars = arg; |
| | 818 | struct batadv_priv *bat_priv = tp_vars->bat_priv; |
| | 819 | struct batadv_hard_iface *primary_if = NULL; |
| | 820 | struct batadv_orig_node *orig_node = NULL; |
| | 821 | size_t payload_len, packet_len; |
| | 822 | int err = 0; |
| | 823 | |
| | 824 | if (unlikely(tp_vars->role != BATADV_TP_SENDER)) { |
| | 825 | err = BATADV_TP_REASON_DST_UNREACHABLE; |
| | 826 | tp_vars->reason = err; |
| | 827 | goto out; |
| | 828 | } |
| | 829 | |
| | 830 | orig_node = batadv_orig_hash_find(bat_priv, tp_vars->other_end); |
| | 831 | if (unlikely(!orig_node)) { |
| | 832 | err = BATADV_TP_REASON_DST_UNREACHABLE; |
| | 833 | tp_vars->reason = err; |
| | 834 | goto out; |
| | 835 | } |
| | 836 | |
| | 837 | primary_if = batadv_primary_if_get_selected(bat_priv); |
| | 838 | if (unlikely(!primary_if)) { |
| | 839 | err = BATADV_TP_REASON_DST_UNREACHABLE; |
| | 840 | goto out; |
| | 841 | } |
| | 842 | |
| | 843 | /* assume that all the hard_interfaces have a correctly |
| | 844 | * configured MTU, so use the soft_iface MTU as MSS. |
| | 845 | * This might not be true and in that case the fragmentation |
| | 846 | * should be used. |
| | 847 | * Now, try to send the packet as it is |
| | 848 | */ |
| | 849 | payload_len = BATADV_TP_PLEN; |
| | 850 | BUILD_BUG_ON(sizeof(struct batadv_icmp_tp_packet) > BATADV_TP_PLEN); |
| | 851 | |
| | 852 | batadv_tp_reset_sender_timer(tp_vars); |
| | 853 | |
| | 854 | /* queue the worker in charge of terminating the test */ |
| | 855 | queue_delayed_work(batadv_event_workqueue, &tp_vars->finish_work, |
| | 856 | msecs_to_jiffies(tp_vars->test_length)); |
| | 857 | |
| | 858 | while (atomic_read(&tp_vars->sending) != 0) { |
| | 859 | if (unlikely(!batadv_tp_avail(tp_vars, payload_len))) { |
| | 860 | batadv_tp_wait_available(tp_vars, payload_len); |
| | 861 | continue; |
| | 862 | } |
| | 863 | |
| | 864 | /* to emulate normal unicast traffic, add to the payload len |
| | 865 | * the size of the unicast header |
| | 866 | */ |
| | 867 | packet_len = payload_len + sizeof(struct batadv_unicast_packet); |
| | 868 | |
| | 869 | err = batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr, |
| | 870 | orig_node, tp_vars->last_sent, |
| | 871 | packet_len, |
| | 872 | tp_vars->session, tp_vars->icmp_uid, |
| | 873 | jiffies_to_msecs(jiffies)); |
| | 874 | |
| | 875 | /* something went wrong during the preparation/transmission */ |
| | 876 | if (unlikely(err && err != BATADV_TP_REASON_CANT_SEND)) { |
| | 877 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 878 | "Meter: batadv_tp_send() cannot send packets (%d)\n", |
| | 879 | err); |
| | 880 | /* ensure nobody else tries to stop the thread now */ |
| | 881 | if (atomic_dec_and_test(&tp_vars->sending)) |
| | 882 | tp_vars->reason = err; |
| | 883 | break; |
| | 884 | } |
| | 885 | |
| | 886 | /* right-shift the TWND */ |
| | 887 | if (!err) |
| | 888 | tp_vars->last_sent += payload_len; |
| | 889 | |
| | 890 | cond_resched(); |
| | 891 | } |
| | 892 | |
| | 893 | out: |
| | 894 | if (likely(primary_if)) |
| | 895 | batadv_hardif_put(primary_if); |
| | 896 | if (likely(orig_node)) |
| | 897 | batadv_orig_node_put(orig_node); |
| | 898 | |
| | 899 | batadv_tp_sender_end(bat_priv, tp_vars); |
| | 900 | batadv_tp_sender_cleanup(bat_priv, tp_vars); |
| | 901 | |
| | 902 | batadv_tp_vars_put(tp_vars); |
| | 903 | |
| | 904 | do_exit(0); |
| | 905 | } |
| | 906 | |
| | 907 | /** |
| | 908 | * batadv_tp_start_kthread - start new thread which manages the tp meter sender |
| | 909 | * @tp_vars: the private data of the current TP meter session |
| | 910 | */ |
| | 911 | static void batadv_tp_start_kthread(struct batadv_tp_vars *tp_vars) |
| | 912 | { |
| | 913 | struct task_struct *kthread; |
| | 914 | struct batadv_priv *bat_priv = tp_vars->bat_priv; |
| | 915 | u32 session_cookie; |
| | 916 | |
| | 917 | kref_get(&tp_vars->refcount); |
| | 918 | kthread = kthread_create(batadv_tp_send, tp_vars, "kbatadv_tp_meter"); |
| | 919 | if (IS_ERR(kthread)) { |
| | 920 | session_cookie = batadv_tp_session_cookie(tp_vars->session, |
| | 921 | tp_vars->icmp_uid); |
| | 922 | pr_err("batadv: cannot create tp meter kthread\n"); |
| | 923 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR, |
| | 924 | tp_vars->other_end, |
| | 925 | bat_priv, session_cookie); |
| | 926 | |
| | 927 | /* drop reserved reference for kthread */ |
| | 928 | batadv_tp_vars_put(tp_vars); |
| | 929 | |
| | 930 | /* cleanup of failed tp meter variables */ |
| | 931 | batadv_tp_sender_cleanup(bat_priv, tp_vars); |
| | 932 | return; |
| | 933 | } |
| | 934 | |
| | 935 | wake_up_process(kthread); |
| | 936 | } |
| | 937 | |
| | 938 | /** |
| | 939 | * batadv_tp_start - start a new tp meter session |
| | 940 | * @bat_priv: the bat priv with all the soft interface information |
| | 941 | * @dst: the receiver MAC address |
| | 942 | * @test_length: test length in milliseconds |
| | 943 | * @cookie: session cookie |
| | 944 | */ |
| | 945 | void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, |
| | 946 | u32 test_length, u32 *cookie) |
| | 947 | { |
| | 948 | struct batadv_tp_vars *tp_vars; |
| | 949 | u8 session_id[2]; |
| | 950 | u8 icmp_uid; |
| | 951 | u32 session_cookie; |
| | 952 | |
| | 953 | get_random_bytes(session_id, sizeof(session_id)); |
| | 954 | get_random_bytes(&icmp_uid, 1); |
| | 955 | session_cookie = batadv_tp_session_cookie(session_id, icmp_uid); |
| | 956 | *cookie = session_cookie; |
| | 957 | |
| | 958 | /* look for an already existing test towards this node */ |
| | 959 | spin_lock_bh(&bat_priv->tp_list_lock); |
| | 960 | tp_vars = batadv_tp_list_find(bat_priv, dst); |
| | 961 | if (tp_vars) { |
| | 962 | spin_unlock_bh(&bat_priv->tp_list_lock); |
| | 963 | batadv_tp_vars_put(tp_vars); |
| | 964 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 965 | "Meter: test to or from the same node already ongoing, aborting\n"); |
| | 966 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_ALREADY_ONGOING, |
| | 967 | dst, bat_priv, session_cookie); |
| | 968 | return; |
| | 969 | } |
| | 970 | |
| | 971 | if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM)) { |
| | 972 | spin_unlock_bh(&bat_priv->tp_list_lock); |
| | 973 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 974 | "Meter: too many ongoing sessions, aborting (SEND)\n"); |
| | 975 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_TOO_MANY, dst, |
| | 976 | bat_priv, session_cookie); |
| | 977 | return; |
| | 978 | } |
| | 979 | |
| | 980 | tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC); |
| | 981 | if (!tp_vars) { |
| | 982 | spin_unlock_bh(&bat_priv->tp_list_lock); |
| | 983 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 984 | "Meter: batadv_tp_start cannot allocate list elements\n"); |
| | 985 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR, |
| | 986 | dst, bat_priv, session_cookie); |
| | 987 | return; |
| | 988 | } |
| | 989 | |
| | 990 | /* initialize tp_vars */ |
| | 991 | ether_addr_copy(tp_vars->other_end, dst); |
| | 992 | kref_init(&tp_vars->refcount); |
| | 993 | tp_vars->role = BATADV_TP_SENDER; |
| | 994 | atomic_set(&tp_vars->sending, 1); |
| | 995 | memcpy(tp_vars->session, session_id, sizeof(session_id)); |
| | 996 | tp_vars->icmp_uid = icmp_uid; |
| | 997 | |
| | 998 | tp_vars->last_sent = BATADV_TP_FIRST_SEQ; |
| | 999 | atomic_set(&tp_vars->last_acked, BATADV_TP_FIRST_SEQ); |
| | 1000 | tp_vars->fast_recovery = false; |
| | 1001 | tp_vars->recover = BATADV_TP_FIRST_SEQ; |
| | 1002 | |
| | 1003 | /* initialise the CWND to 3*MSS (Section 3.1 in RFC5681). |
| | 1004 | * For batman-adv the MSS is the size of the payload received by the |
| | 1005 | * soft_interface, hence its MTU |
| | 1006 | */ |
| | 1007 | tp_vars->cwnd = BATADV_TP_PLEN * 3; |
| | 1008 | /* at the beginning initialise the SS threshold to the biggest possible |
| | 1009 | * window size, hence the AWND size |
| | 1010 | */ |
| | 1011 | tp_vars->ss_threshold = BATADV_TP_AWND; |
| | 1012 | |
| | 1013 | /* RTO initial value is 3 seconds. |
| | 1014 | * Details in Section 2.1 of RFC6298 |
| | 1015 | */ |
| | 1016 | tp_vars->rto = 1000; |
| | 1017 | tp_vars->srtt = 0; |
| | 1018 | tp_vars->rttvar = 0; |
| | 1019 | |
| | 1020 | atomic64_set(&tp_vars->tot_sent, 0); |
| | 1021 | |
| | 1022 | kref_get(&tp_vars->refcount); |
| | 1023 | setup_timer(&tp_vars->timer, batadv_tp_sender_timeout, |
| | 1024 | (unsigned long)tp_vars); |
| | 1025 | |
| | 1026 | tp_vars->bat_priv = bat_priv; |
| | 1027 | tp_vars->start_time = jiffies; |
| | 1028 | |
| | 1029 | init_waitqueue_head(&tp_vars->more_bytes); |
| | 1030 | |
| | 1031 | spin_lock_init(&tp_vars->unacked_lock); |
| | 1032 | INIT_LIST_HEAD(&tp_vars->unacked_list); |
| | 1033 | |
| | 1034 | spin_lock_init(&tp_vars->cwnd_lock); |
| | 1035 | |
| | 1036 | tp_vars->prerandom_offset = 0; |
| | 1037 | spin_lock_init(&tp_vars->prerandom_lock); |
| | 1038 | |
| | 1039 | kref_get(&tp_vars->refcount); |
| | 1040 | hlist_add_head_rcu(&tp_vars->list, &bat_priv->tp_list); |
| | 1041 | spin_unlock_bh(&bat_priv->tp_list_lock); |
| | 1042 | |
| | 1043 | tp_vars->test_length = test_length; |
| | 1044 | if (!tp_vars->test_length) |
| | 1045 | tp_vars->test_length = BATADV_TP_DEF_TEST_LENGTH; |
| | 1046 | |
| | 1047 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1048 | "Meter: starting throughput meter towards %pM (length=%ums)\n", |
| | 1049 | dst, test_length); |
| | 1050 | |
| | 1051 | /* init work item for finished tp tests */ |
| | 1052 | INIT_DELAYED_WORK(&tp_vars->finish_work, batadv_tp_sender_finish); |
| | 1053 | |
| | 1054 | /* start tp kthread. This way the write() call issued from userspace can |
| | 1055 | * happily return and avoid to block |
| | 1056 | */ |
| | 1057 | batadv_tp_start_kthread(tp_vars); |
| | 1058 | |
| | 1059 | /* don't return reference to new tp_vars */ |
| | 1060 | batadv_tp_vars_put(tp_vars); |
| | 1061 | } |
| | 1062 | |
| | 1063 | /** |
| | 1064 | * batadv_tp_stop - stop currently running tp meter session |
| | 1065 | * @bat_priv: the bat priv with all the soft interface information |
| | 1066 | * @dst: the receiver MAC address |
| | 1067 | * @return_value: reason for tp meter session stop |
| | 1068 | */ |
| | 1069 | void batadv_tp_stop(struct batadv_priv *bat_priv, const u8 *dst, |
| | 1070 | u8 return_value) |
| | 1071 | { |
| | 1072 | struct batadv_orig_node *orig_node; |
| | 1073 | struct batadv_tp_vars *tp_vars; |
| | 1074 | |
| | 1075 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1076 | "Meter: stopping test towards %pM\n", dst); |
| | 1077 | |
| | 1078 | orig_node = batadv_orig_hash_find(bat_priv, dst); |
| | 1079 | if (!orig_node) |
| | 1080 | return; |
| | 1081 | |
| | 1082 | tp_vars = batadv_tp_list_find(bat_priv, orig_node->orig); |
| | 1083 | if (!tp_vars) { |
| | 1084 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1085 | "Meter: trying to interrupt an already over connection\n"); |
| | 1086 | goto out; |
| | 1087 | } |
| | 1088 | |
| | 1089 | batadv_tp_sender_shutdown(tp_vars, return_value); |
| | 1090 | batadv_tp_vars_put(tp_vars); |
| | 1091 | out: |
| | 1092 | batadv_orig_node_put(orig_node); |
| | 1093 | } |
| | 1094 | |
| | 1095 | /** |
| | 1096 | * batadv_tp_reset_receiver_timer - reset the receiver shutdown timer |
| | 1097 | * @tp_vars: the private data of the current TP meter session |
| | 1098 | * |
| | 1099 | * start the receiver shutdown timer or reset it if already started |
| | 1100 | */ |
| | 1101 | static void batadv_tp_reset_receiver_timer(struct batadv_tp_vars *tp_vars) |
| | 1102 | { |
| | 1103 | mod_timer(&tp_vars->timer, |
| | 1104 | jiffies + msecs_to_jiffies(BATADV_TP_RECV_TIMEOUT)); |
| | 1105 | } |
| | 1106 | |
| | 1107 | /** |
| | 1108 | * batadv_tp_receiver_shutdown - stop a tp meter receiver when timeout is |
| | 1109 | * reached without received ack |
| | 1110 | * @arg: address of the related tp_vars |
| | 1111 | */ |
| | 1112 | static void batadv_tp_receiver_shutdown(unsigned long arg) |
| | 1113 | { |
| | 1114 | struct batadv_tp_vars *tp_vars = (struct batadv_tp_vars *)arg; |
| | 1115 | struct batadv_tp_unacked *un, *safe; |
| | 1116 | struct batadv_priv *bat_priv; |
| | 1117 | |
| | 1118 | bat_priv = tp_vars->bat_priv; |
| | 1119 | |
| | 1120 | /* if there is recent activity rearm the timer */ |
| | 1121 | if (!batadv_has_timed_out(tp_vars->last_recv_time, |
| | 1122 | BATADV_TP_RECV_TIMEOUT)) { |
| | 1123 | /* reset the receiver shutdown timer */ |
| | 1124 | batadv_tp_reset_receiver_timer(tp_vars); |
| | 1125 | return; |
| | 1126 | } |
| | 1127 | |
| | 1128 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1129 | "Shutting down for inactivity (more than %dms) from %pM\n", |
| | 1130 | BATADV_TP_RECV_TIMEOUT, tp_vars->other_end); |
| | 1131 | |
| | 1132 | spin_lock_bh(&tp_vars->bat_priv->tp_list_lock); |
| | 1133 | hlist_del_rcu(&tp_vars->list); |
| | 1134 | spin_unlock_bh(&tp_vars->bat_priv->tp_list_lock); |
| | 1135 | |
| | 1136 | /* drop list reference */ |
| | 1137 | batadv_tp_vars_put(tp_vars); |
| | 1138 | |
| | 1139 | atomic_dec(&bat_priv->tp_num); |
| | 1140 | |
| | 1141 | spin_lock_bh(&tp_vars->unacked_lock); |
| | 1142 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { |
| | 1143 | list_del(&un->list); |
| | 1144 | kfree(un); |
| | 1145 | } |
| | 1146 | spin_unlock_bh(&tp_vars->unacked_lock); |
| | 1147 | |
| | 1148 | /* drop reference of timer */ |
| | 1149 | batadv_tp_vars_put(tp_vars); |
| | 1150 | } |
| | 1151 | |
| | 1152 | /** |
| | 1153 | * batadv_tp_send_ack - send an ACK packet |
| | 1154 | * @bat_priv: the bat priv with all the soft interface information |
| | 1155 | * @dst: the mac address of the destination originator |
| | 1156 | * @seq: the sequence number to ACK |
| | 1157 | * @timestamp: the timestamp to echo back in the ACK |
| | 1158 | * @session: session identifier |
| | 1159 | * @socket_index: local ICMP socket identifier |
| | 1160 | * |
| | 1161 | * Return: 0 on success, a positive integer representing the reason of the |
| | 1162 | * failure otherwise |
| | 1163 | */ |
| | 1164 | static int batadv_tp_send_ack(struct batadv_priv *bat_priv, const u8 *dst, |
| | 1165 | u32 seq, __be32 timestamp, const u8 *session, |
| | 1166 | int socket_index) |
| | 1167 | { |
| | 1168 | struct batadv_hard_iface *primary_if = NULL; |
| | 1169 | struct batadv_orig_node *orig_node; |
| | 1170 | struct batadv_icmp_tp_packet *icmp; |
| | 1171 | struct sk_buff *skb; |
| | 1172 | int r, ret; |
| | 1173 | |
| | 1174 | orig_node = batadv_orig_hash_find(bat_priv, dst); |
| | 1175 | if (unlikely(!orig_node)) { |
| | 1176 | ret = BATADV_TP_REASON_DST_UNREACHABLE; |
| | 1177 | goto out; |
| | 1178 | } |
| | 1179 | |
| | 1180 | primary_if = batadv_primary_if_get_selected(bat_priv); |
| | 1181 | if (unlikely(!primary_if)) { |
| | 1182 | ret = BATADV_TP_REASON_DST_UNREACHABLE; |
| | 1183 | goto out; |
| | 1184 | } |
| | 1185 | |
| | 1186 | skb = netdev_alloc_skb_ip_align(NULL, sizeof(*icmp) + ETH_HLEN); |
| | 1187 | if (unlikely(!skb)) { |
| | 1188 | ret = BATADV_TP_REASON_MEMORY_ERROR; |
| | 1189 | goto out; |
| | 1190 | } |
| | 1191 | |
| | 1192 | skb_reserve(skb, ETH_HLEN); |
| | 1193 | icmp = (struct batadv_icmp_tp_packet *)skb_put(skb, sizeof(*icmp)); |
| | 1194 | icmp->packet_type = BATADV_ICMP; |
| | 1195 | icmp->version = BATADV_COMPAT_VERSION; |
| | 1196 | icmp->ttl = BATADV_TTL; |
| | 1197 | icmp->msg_type = BATADV_TP; |
| | 1198 | ether_addr_copy(icmp->dst, orig_node->orig); |
| | 1199 | ether_addr_copy(icmp->orig, primary_if->net_dev->dev_addr); |
| | 1200 | icmp->uid = socket_index; |
| | 1201 | |
| | 1202 | icmp->subtype = BATADV_TP_ACK; |
| | 1203 | memcpy(icmp->session, session, sizeof(icmp->session)); |
| | 1204 | icmp->seqno = htonl(seq); |
| | 1205 | icmp->timestamp = timestamp; |
| | 1206 | |
| | 1207 | /* send the ack */ |
| | 1208 | r = batadv_send_skb_to_orig(skb, orig_node, NULL); |
| | 1209 | if (r == -1) |
| | 1210 | kfree_skb(skb); |
| | 1211 | |
| | 1212 | if (unlikely(r < 0) || (r == NET_XMIT_DROP)) { |
| | 1213 | ret = BATADV_TP_REASON_DST_UNREACHABLE; |
| | 1214 | goto out; |
| | 1215 | } |
| | 1216 | ret = 0; |
| | 1217 | |
| | 1218 | out: |
| | 1219 | if (likely(orig_node)) |
| | 1220 | batadv_orig_node_put(orig_node); |
| | 1221 | if (likely(primary_if)) |
| | 1222 | batadv_hardif_put(primary_if); |
| | 1223 | |
| | 1224 | return ret; |
| | 1225 | } |
| | 1226 | |
| | 1227 | /** |
| | 1228 | * batadv_tp_handle_out_of_order - store an out of order packet |
| | 1229 | * @tp_vars: the private data of the current TP meter session |
| | 1230 | * @skb: the buffer containing the received packet |
| | 1231 | * |
| | 1232 | * Store the out of order packet in the unacked list for late processing. This |
| | 1233 | * packets are kept in this list so that they can be ACKed at once as soon as |
| | 1234 | * all the previous packets have been received |
| | 1235 | * |
| | 1236 | * Return: true if the packed has been successfully processed, false otherwise |
| | 1237 | */ |
| | 1238 | static bool batadv_tp_handle_out_of_order(struct batadv_tp_vars *tp_vars, |
| | 1239 | const struct sk_buff *skb) |
| | 1240 | { |
| | 1241 | const struct batadv_icmp_tp_packet *icmp; |
| | 1242 | struct batadv_tp_unacked *un, *new; |
| | 1243 | u32 payload_len; |
| | 1244 | bool added = false; |
| | 1245 | |
| | 1246 | new = kmalloc(sizeof(*new), GFP_ATOMIC); |
| | 1247 | if (unlikely(!new)) |
| | 1248 | return false; |
| | 1249 | |
| | 1250 | icmp = (struct batadv_icmp_tp_packet *)skb->data; |
| | 1251 | |
| | 1252 | new->seqno = ntohl(icmp->seqno); |
| | 1253 | payload_len = skb->len - sizeof(struct batadv_unicast_packet); |
| | 1254 | new->len = payload_len; |
| | 1255 | |
| | 1256 | spin_lock_bh(&tp_vars->unacked_lock); |
| | 1257 | /* if the list is empty immediately attach this new object */ |
| | 1258 | if (list_empty(&tp_vars->unacked_list)) { |
| | 1259 | list_add(&new->list, &tp_vars->unacked_list); |
| | 1260 | goto out; |
| | 1261 | } |
| | 1262 | |
| | 1263 | /* otherwise loop over the list and either drop the packet because this |
| | 1264 | * is a duplicate or store it at the right position. |
| | 1265 | * |
| | 1266 | * The iteration is done in the reverse way because it is likely that |
| | 1267 | * the last received packet (the one being processed now) has a bigger |
| | 1268 | * seqno than all the others already stored. |
| | 1269 | */ |
| | 1270 | list_for_each_entry_reverse(un, &tp_vars->unacked_list, list) { |
| | 1271 | /* check for duplicates */ |
| | 1272 | if (new->seqno == un->seqno) { |
| | 1273 | if (new->len > un->len) |
| | 1274 | un->len = new->len; |
| | 1275 | kfree(new); |
| | 1276 | added = true; |
| | 1277 | break; |
| | 1278 | } |
| | 1279 | |
| | 1280 | /* look for the right position */ |
| | 1281 | if (batadv_seq_before(new->seqno, un->seqno)) |
| | 1282 | continue; |
| | 1283 | |
| | 1284 | /* as soon as an entry having a bigger seqno is found, the new |
| | 1285 | * one is attached _after_ it. In this way the list is kept in |
| | 1286 | * ascending order |
| | 1287 | */ |
| | 1288 | list_add_tail(&new->list, &un->list); |
| | 1289 | added = true; |
| | 1290 | break; |
| | 1291 | } |
| | 1292 | |
| | 1293 | /* received packet with smallest seqno out of order; add it to front */ |
| | 1294 | if (!added) |
| | 1295 | list_add(&new->list, &tp_vars->unacked_list); |
| | 1296 | |
| | 1297 | out: |
| | 1298 | spin_unlock_bh(&tp_vars->unacked_lock); |
| | 1299 | |
| | 1300 | return true; |
| | 1301 | } |
| | 1302 | |
| | 1303 | /** |
| | 1304 | * batadv_tp_ack_unordered - update number received bytes in current stream |
| | 1305 | * without gaps |
| | 1306 | * @tp_vars: the private data of the current TP meter session |
| | 1307 | */ |
| | 1308 | static void batadv_tp_ack_unordered(struct batadv_tp_vars *tp_vars) |
| | 1309 | { |
| | 1310 | struct batadv_tp_unacked *un, *safe; |
| | 1311 | u32 to_ack; |
| | 1312 | |
| | 1313 | /* go through the unacked packet list and possibly ACK them as |
| | 1314 | * well |
| | 1315 | */ |
| | 1316 | spin_lock_bh(&tp_vars->unacked_lock); |
| | 1317 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { |
| | 1318 | /* the list is ordered, therefore it is possible to stop as soon |
| | 1319 | * there is a gap between the last acked seqno and the seqno of |
| | 1320 | * the packet under inspection |
| | 1321 | */ |
| | 1322 | if (batadv_seq_before(tp_vars->last_recv, un->seqno)) |
| | 1323 | break; |
| | 1324 | |
| | 1325 | to_ack = un->seqno + un->len - tp_vars->last_recv; |
| | 1326 | |
| | 1327 | if (batadv_seq_before(tp_vars->last_recv, un->seqno + un->len)) |
| | 1328 | tp_vars->last_recv += to_ack; |
| | 1329 | |
| | 1330 | list_del(&un->list); |
| | 1331 | kfree(un); |
| | 1332 | } |
| | 1333 | spin_unlock_bh(&tp_vars->unacked_lock); |
| | 1334 | } |
| | 1335 | |
| | 1336 | /** |
| | 1337 | * batadv_tp_init_recv - return matching or create new receiver tp_vars |
| | 1338 | * @bat_priv: the bat priv with all the soft interface information |
| | 1339 | * @icmp: received icmp tp msg |
| | 1340 | * |
| | 1341 | * Return: corresponding tp_vars or NULL on errors |
| | 1342 | */ |
| | 1343 | static struct batadv_tp_vars * |
| | 1344 | batadv_tp_init_recv(struct batadv_priv *bat_priv, |
| | 1345 | const struct batadv_icmp_tp_packet *icmp) |
| | 1346 | { |
| | 1347 | struct batadv_tp_vars *tp_vars; |
| | 1348 | |
| | 1349 | spin_lock_bh(&bat_priv->tp_list_lock); |
| | 1350 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, |
| | 1351 | icmp->session); |
| | 1352 | if (tp_vars) |
| | 1353 | goto out_unlock; |
| | 1354 | |
| | 1355 | if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM)) { |
| | 1356 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1357 | "Meter: too many ongoing sessions, aborting (RECV)\n"); |
| | 1358 | goto out_unlock; |
| | 1359 | } |
| | 1360 | |
| | 1361 | tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC); |
| | 1362 | if (!tp_vars) |
| | 1363 | goto out_unlock; |
| | 1364 | |
| | 1365 | ether_addr_copy(tp_vars->other_end, icmp->orig); |
| | 1366 | tp_vars->role = BATADV_TP_RECEIVER; |
| | 1367 | memcpy(tp_vars->session, icmp->session, sizeof(tp_vars->session)); |
| | 1368 | tp_vars->last_recv = BATADV_TP_FIRST_SEQ; |
| | 1369 | tp_vars->bat_priv = bat_priv; |
| | 1370 | kref_init(&tp_vars->refcount); |
| | 1371 | |
| | 1372 | spin_lock_init(&tp_vars->unacked_lock); |
| | 1373 | INIT_LIST_HEAD(&tp_vars->unacked_list); |
| | 1374 | |
| | 1375 | kref_get(&tp_vars->refcount); |
| | 1376 | hlist_add_head_rcu(&tp_vars->list, &bat_priv->tp_list); |
| | 1377 | |
| | 1378 | kref_get(&tp_vars->refcount); |
| | 1379 | setup_timer(&tp_vars->timer, batadv_tp_receiver_shutdown, |
| | 1380 | (unsigned long)tp_vars); |
| | 1381 | |
| | 1382 | batadv_tp_reset_receiver_timer(tp_vars); |
| | 1383 | |
| | 1384 | out_unlock: |
| | 1385 | spin_unlock_bh(&bat_priv->tp_list_lock); |
| | 1386 | |
| | 1387 | return tp_vars; |
| | 1388 | } |
| | 1389 | |
| | 1390 | /** |
| | 1391 | * batadv_tp_recv_msg - process a single data message |
| | 1392 | * @bat_priv: the bat priv with all the soft interface information |
| | 1393 | * @skb: the buffer containing the received packet |
| | 1394 | * |
| | 1395 | * Process a received TP MSG packet |
| | 1396 | */ |
| | 1397 | static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, |
| | 1398 | const struct sk_buff *skb) |
| | 1399 | { |
| | 1400 | const struct batadv_icmp_tp_packet *icmp; |
| | 1401 | struct batadv_tp_vars *tp_vars; |
| | 1402 | size_t packet_size; |
| | 1403 | u32 seqno; |
| | 1404 | |
| | 1405 | icmp = (struct batadv_icmp_tp_packet *)skb->data; |
| | 1406 | |
| | 1407 | seqno = ntohl(icmp->seqno); |
| | 1408 | /* check if this is the first seqno. This means that if the |
| | 1409 | * first packet is lost, the tp meter does not work anymore! |
| | 1410 | */ |
| | 1411 | if (seqno == BATADV_TP_FIRST_SEQ) { |
| | 1412 | tp_vars = batadv_tp_init_recv(bat_priv, icmp); |
| | 1413 | if (!tp_vars) { |
| | 1414 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1415 | "Meter: seqno != BATADV_TP_FIRST_SEQ cannot initiate connection\n"); |
| | 1416 | goto out; |
| | 1417 | } |
| | 1418 | } else { |
| | 1419 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, |
| | 1420 | icmp->session); |
| | 1421 | if (!tp_vars) { |
| | 1422 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1423 | "Unexpected packet from %pM!\n", |
| | 1424 | icmp->orig); |
| | 1425 | goto out; |
| | 1426 | } |
| | 1427 | } |
| | 1428 | |
| | 1429 | if (unlikely(tp_vars->role != BATADV_TP_RECEIVER)) { |
| | 1430 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1431 | "Meter: dropping packet: not expected (role=%u)\n", |
| | 1432 | tp_vars->role); |
| | 1433 | goto out; |
| | 1434 | } |
| | 1435 | |
| | 1436 | tp_vars->last_recv_time = jiffies; |
| | 1437 | |
| | 1438 | /* if the packet is a duplicate, it may be the case that an ACK has been |
| | 1439 | * lost. Resend the ACK |
| | 1440 | */ |
| | 1441 | if (batadv_seq_before(seqno, tp_vars->last_recv)) |
| | 1442 | goto send_ack; |
| | 1443 | |
| | 1444 | /* if the packet is out of order enqueue it */ |
| | 1445 | if (ntohl(icmp->seqno) != tp_vars->last_recv) { |
| | 1446 | /* exit immediately (and do not send any ACK) if the packet has |
| | 1447 | * not been enqueued correctly |
| | 1448 | */ |
| | 1449 | if (!batadv_tp_handle_out_of_order(tp_vars, skb)) |
| | 1450 | goto out; |
| | 1451 | |
| | 1452 | /* send a duplicate ACK */ |
| | 1453 | goto send_ack; |
| | 1454 | } |
| | 1455 | |
| | 1456 | /* if everything was fine count the ACKed bytes */ |
| | 1457 | packet_size = skb->len - sizeof(struct batadv_unicast_packet); |
| | 1458 | tp_vars->last_recv += packet_size; |
| | 1459 | |
| | 1460 | /* check if this ordered message filled a gap.... */ |
| | 1461 | batadv_tp_ack_unordered(tp_vars); |
| | 1462 | |
| | 1463 | send_ack: |
| | 1464 | /* send the ACK. If the received packet was out of order, the ACK that |
| | 1465 | * is going to be sent is a duplicate (the sender will count them and |
| | 1466 | * possibly enter Fast Retransmit as soon as it has reached 3) |
| | 1467 | */ |
| | 1468 | batadv_tp_send_ack(bat_priv, icmp->orig, tp_vars->last_recv, |
| | 1469 | icmp->timestamp, icmp->session, icmp->uid); |
| | 1470 | out: |
| | 1471 | if (likely(tp_vars)) |
| | 1472 | batadv_tp_vars_put(tp_vars); |
| | 1473 | } |
| | 1474 | |
| | 1475 | /** |
| | 1476 | * batadv_tp_meter_recv - main TP Meter receiving function |
| | 1477 | * @bat_priv: the bat priv with all the soft interface information |
| | 1478 | * @skb: the buffer containing the received packet |
| | 1479 | */ |
| | 1480 | void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb) |
| | 1481 | { |
| | 1482 | struct batadv_icmp_tp_packet *icmp; |
| | 1483 | |
| | 1484 | icmp = (struct batadv_icmp_tp_packet *)skb->data; |
| | 1485 | |
| | 1486 | switch (icmp->subtype) { |
| | 1487 | case BATADV_TP_MSG: |
| | 1488 | batadv_tp_recv_msg(bat_priv, skb); |
| | 1489 | break; |
| | 1490 | case BATADV_TP_ACK: |
| | 1491 | batadv_tp_recv_ack(bat_priv, skb); |
| | 1492 | break; |
| | 1493 | default: |
| | 1494 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
| | 1495 | "Received unknown TP Metric packet type %u\n", |
| | 1496 | icmp->subtype); |
| | 1497 | } |
| | 1498 | consume_skb(skb); |
| | 1499 | } |
| | 1500 | |
| | 1501 | /** |
| | 1502 | * batadv_tp_meter_init - initialize global tp_meter structures |
| | 1503 | */ |
| | 1504 | void batadv_tp_meter_init(void) |
| | 1505 | { |
| | 1506 | get_random_bytes(batadv_tp_prerandom, sizeof(batadv_tp_prerandom)); |
| | 1507 | } |