1204591Sluigi/*- 2204591Sluigi * Copyright (c) 2010 Luigi Rizzo, Riccardo Panicucci, Universita` di Pisa 3204591Sluigi * All rights reserved 4204591Sluigi * 5204591Sluigi * Redistribution and use in source and binary forms, with or without 6204591Sluigi * modification, are permitted provided that the following conditions 7204591Sluigi * are met: 8204591Sluigi * 1. Redistributions of source code must retain the above copyright 9204591Sluigi * notice, this list of conditions and the following disclaimer. 10204591Sluigi * 2. Redistributions in binary form must reproduce the above copyright 11204591Sluigi * notice, this list of conditions and the following disclaimer in the 12204591Sluigi * documentation and/or other materials provided with the distribution. 13204591Sluigi * 14204591Sluigi * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15204591Sluigi * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16204591Sluigi * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17204591Sluigi * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18204591Sluigi * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19204591Sluigi * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20204591Sluigi * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21204591Sluigi * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22204591Sluigi * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23204591Sluigi * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24204591Sluigi * SUCH DAMAGE. 25204591Sluigi */ 26204591Sluigi 27204591Sluigi/* 28204591Sluigi * Dummynet portions related to packet handling. 29204591Sluigi */ 30204591Sluigi#include <sys/cdefs.h> 31204591Sluigi__FBSDID("$FreeBSD: stable/10/sys/netpfil/ipfw/ip_dn_io.c 325731 2017-11-12 01:28:20Z truckman $"); 32204591Sluigi 33204591Sluigi#include "opt_inet6.h" 34204591Sluigi 35204591Sluigi#include <sys/param.h> 36204591Sluigi#include <sys/systm.h> 37204591Sluigi#include <sys/malloc.h> 38204591Sluigi#include <sys/mbuf.h> 39204591Sluigi#include <sys/kernel.h> 40204591Sluigi#include <sys/lock.h> 41204591Sluigi#include <sys/module.h> 42204591Sluigi#include <sys/priv.h> 43204591Sluigi#include <sys/proc.h> 44204591Sluigi#include <sys/rwlock.h> 45204591Sluigi#include <sys/socket.h> 46204591Sluigi#include <sys/time.h> 47204591Sluigi#include <sys/sysctl.h> 48206461Sbz 49204591Sluigi#include <net/if.h> /* IFNAMSIZ, struct ifaddr, ifq head, lock.h mutex.h */ 50204591Sluigi#include <net/netisr.h> 51206461Sbz#include <net/vnet.h> 52206461Sbz 53204591Sluigi#include <netinet/in.h> 54204591Sluigi#include <netinet/ip.h> /* ip_len, ip_off */ 55204591Sluigi#include <netinet/ip_var.h> /* ip_output(), IP_FORWARDING */ 56204591Sluigi#include <netinet/ip_fw.h> 57204591Sluigi#include <netinet/ip_dummynet.h> 58204591Sluigi#include <netinet/if_ether.h> /* various ether_* routines */ 59204591Sluigi#include <netinet/ip6.h> /* for ip6_input, ip6_output prototypes */ 60204591Sluigi#include <netinet6/ip6_var.h> 61204591Sluigi 62240494Sglebius#include <netpfil/ipfw/ip_fw_private.h> 63240494Sglebius#include <netpfil/ipfw/dn_heap.h> 64240494Sglebius#include <netpfil/ipfw/ip_dn_private.h> 65301772Struckman#ifdef NEW_AQM 66301772Struckman#include <netpfil/ipfw/dn_aqm.h> 67301772Struckman#endif 68240494Sglebius#include <netpfil/ipfw/dn_sched.h> 69240494Sglebius 70204591Sluigi/* 71204591Sluigi * We keep a private variable for the simulation time, but we could 72204591Sluigi * probably use an existing one ("softticks" in sys/kern/kern_timeout.c) 73204591Sluigi * instead of dn_cfg.curr_time 74204591Sluigi */ 75204591Sluigi 76204591Sluigistruct dn_parms dn_cfg; 77206428Sluigi//VNET_DEFINE(struct dn_parms, _base_dn_cfg); 78204591Sluigi 79204591Sluigistatic long tick_last; /* Last tick duration (usec). */ 80204591Sluigistatic long tick_delta; /* Last vs standard tick diff (usec). */ 81204591Sluigistatic long tick_delta_sum; /* Accumulated tick difference (usec).*/ 82204591Sluigistatic long tick_adjustment; /* Tick adjustments done. */ 83204591Sluigistatic long tick_lost; /* Lost(coalesced) ticks number. */ 84204591Sluigi/* Adjusted vs non-adjusted curr_time difference (ticks). */ 85204591Sluigistatic long tick_diff; 86204591Sluigi 87204591Sluigistatic unsigned long io_pkt; 88204591Sluigistatic unsigned long io_pkt_fast; 89301772Struckman 90301772Struckman#ifdef NEW_AQM 91301772Struckmanunsigned long io_pkt_drop; 92301772Struckman#else 93204591Sluigistatic unsigned long io_pkt_drop; 94301772Struckman#endif 95204591Sluigi/* 96204591Sluigi * We use a heap to store entities for which we have pending timer events. 97204591Sluigi * The heap is checked at every tick and all entities with expired events 98204591Sluigi * are extracted. 99204591Sluigi */ 100204591Sluigi 101204591SluigiMALLOC_DEFINE(M_DUMMYNET, "dummynet", "dummynet heap"); 102204591Sluigi 103204591Sluigiextern void (*bridge_dn_p)(struct mbuf *, struct ifnet *); 104204591Sluigi 105204591Sluigi#ifdef SYSCTL_NODE 106204591Sluigi 107239093Sluigi/* 108239093Sluigi * Because of the way the SYSBEGIN/SYSEND macros work on other 109239093Sluigi * platforms, there should not be functions between them. 110239093Sluigi * So keep the handlers outside the block. 111239093Sluigi */ 112220832Saestatic int 113220832Saesysctl_hash_size(SYSCTL_HANDLER_ARGS) 114220832Sae{ 115220832Sae int error, value; 116220832Sae 117220832Sae value = dn_cfg.hash_size; 118220832Sae error = sysctl_handle_int(oidp, &value, 0, req); 119220832Sae if (error != 0 || req->newptr == NULL) 120220832Sae return (error); 121220832Sae if (value < 16 || value > 65536) 122220832Sae return (EINVAL); 123220832Sae dn_cfg.hash_size = value; 124220832Sae return (0); 125220832Sae} 126220832Sae 127220832Saestatic int 128220832Saesysctl_limits(SYSCTL_HANDLER_ARGS) 129220832Sae{ 130220832Sae int error; 131220832Sae long value; 132220832Sae 133220832Sae if (arg2 != 0) 134220832Sae value = dn_cfg.slot_limit; 135220832Sae else 136220832Sae value = dn_cfg.byte_limit; 137220832Sae error = sysctl_handle_long(oidp, &value, 0, req); 138220832Sae 139220832Sae if (error != 0 || req->newptr == NULL) 140220832Sae return (error); 141220832Sae if (arg2 != 0) { 142220832Sae if (value < 1) 143220832Sae return (EINVAL); 144220832Sae dn_cfg.slot_limit = value; 145220832Sae } else { 146220832Sae if (value < 1500) 147220832Sae return (EINVAL); 148220832Sae dn_cfg.byte_limit = value; 149220832Sae } 150220832Sae return (0); 151220832Sae} 152220832Sae 153239093SluigiSYSBEGIN(f4) 154239093Sluigi 155239093SluigiSYSCTL_DECL(_net_inet); 156239093SluigiSYSCTL_DECL(_net_inet_ip); 157301772Struckman#ifdef NEW_AQM 158301772StruckmanSYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW, 0, "Dummynet"); 159301772Struckman#else 160239093Sluigistatic SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW, 0, "Dummynet"); 161301772Struckman#endif 162239093Sluigi 163239093Sluigi/* wrapper to pass dn_cfg fields to SYSCTL_* */ 164239093Sluigi//#define DC(x) (&(VNET_NAME(_base_dn_cfg).x)) 165239093Sluigi#define DC(x) (&(dn_cfg.x)) 166239093Sluigi/* parameters */ 167239093Sluigi 168239093Sluigi 169239093SluigiSYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, hash_size, 170239093Sluigi CTLTYPE_INT | CTLFLAG_RW, 0, 0, sysctl_hash_size, 171239093Sluigi "I", "Default hash table size"); 172239093Sluigi 173239093Sluigi 174220832SaeSYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_slot_limit, 175220832Sae CTLTYPE_LONG | CTLFLAG_RW, 0, 1, sysctl_limits, 176220832Sae "L", "Upper limit in slots for pipe queue."); 177220832SaeSYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_byte_limit, 178220832Sae CTLTYPE_LONG | CTLFLAG_RW, 0, 0, sysctl_limits, 179220832Sae "L", "Upper limit in bytes for pipe queue."); 180204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, io_fast, 181206428Sluigi CTLFLAG_RW, DC(io_fast), 0, "Enable fast dummynet io."); 182204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug, 183206428Sluigi CTLFLAG_RW, DC(debug), 0, "Dummynet debug level"); 184204591Sluigi 185204591Sluigi/* RED parameters */ 186204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_lookup_depth, 187206428Sluigi CTLFLAG_RD, DC(red_lookup_depth), 0, "Depth of RED lookup table"); 188204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_avg_pkt_size, 189206428Sluigi CTLFLAG_RD, DC(red_avg_pkt_size), 0, "RED Medium packet size"); 190204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_max_pkt_size, 191206428Sluigi CTLFLAG_RD, DC(red_max_pkt_size), 0, "RED Max packet size"); 192204591Sluigi 193204591Sluigi/* time adjustment */ 194204591SluigiSYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta, 195204591Sluigi CTLFLAG_RD, &tick_delta, 0, "Last vs standard tick difference (usec)."); 196204591SluigiSYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta_sum, 197204591Sluigi CTLFLAG_RD, &tick_delta_sum, 0, "Accumulated tick difference (usec)."); 198204591SluigiSYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_adjustment, 199204591Sluigi CTLFLAG_RD, &tick_adjustment, 0, "Tick adjustments done."); 200204591SluigiSYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_diff, 201204591Sluigi CTLFLAG_RD, &tick_diff, 0, 202204591Sluigi "Adjusted vs non-adjusted curr_time difference (ticks)."); 203204591SluigiSYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_lost, 204204591Sluigi CTLFLAG_RD, &tick_lost, 0, 205204591Sluigi "Number of ticks coalesced by dummynet taskqueue."); 206204591Sluigi 207213267Sluigi/* Drain parameters */ 208217322SmdfSYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire, 209213267Sluigi CTLFLAG_RW, DC(expire), 0, "Expire empty queues/pipes"); 210217322SmdfSYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire_cycle, 211213267Sluigi CTLFLAG_RD, DC(expire_cycle), 0, "Expire cycle for queues/pipes"); 212213267Sluigi 213204591Sluigi/* statistics */ 214204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, schk_count, 215206428Sluigi CTLFLAG_RD, DC(schk_count), 0, "Number of schedulers"); 216204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, si_count, 217206428Sluigi CTLFLAG_RD, DC(si_count), 0, "Number of scheduler instances"); 218204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, fsk_count, 219206428Sluigi CTLFLAG_RD, DC(fsk_count), 0, "Number of flowsets"); 220204591SluigiSYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, queue_count, 221206428Sluigi CTLFLAG_RD, DC(queue_count), 0, "Number of queues"); 222204591SluigiSYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt, 223204591Sluigi CTLFLAG_RD, &io_pkt, 0, 224204591Sluigi "Number of packets passed to dummynet."); 225204591SluigiSYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_fast, 226204591Sluigi CTLFLAG_RD, &io_pkt_fast, 0, 227204591Sluigi "Number of packets bypassed dummynet scheduler."); 228204591SluigiSYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_drop, 229204591Sluigi CTLFLAG_RD, &io_pkt_drop, 0, 230204591Sluigi "Number of packets dropped by dummynet."); 231206428Sluigi#undef DC 232204591SluigiSYSEND 233204591Sluigi 234204591Sluigi#endif 235204591Sluigi 236204591Sluigistatic void dummynet_send(struct mbuf *); 237204591Sluigi 238204591Sluigi/* 239204591Sluigi * Return the mbuf tag holding the dummynet state (it should 240204591Sluigi * be the first one on the list). 241204591Sluigi */ 242325731Struckmanstruct dn_pkt_tag * 243204591Sluigidn_tag_get(struct mbuf *m) 244204591Sluigi{ 245204591Sluigi struct m_tag *mtag = m_tag_first(m); 246301772Struckman#ifdef NEW_AQM 247301772Struckman /* XXX: to skip ts m_tag. For Debugging only*/ 248301772Struckman if (mtag != NULL && mtag->m_tag_id == DN_AQM_MTAG_TS) { 249301772Struckman m_tag_delete(m,mtag); 250301772Struckman mtag = m_tag_first(m); 251301772Struckman D("skip TS tag"); 252301772Struckman } 253301772Struckman#endif 254204591Sluigi KASSERT(mtag != NULL && 255204591Sluigi mtag->m_tag_cookie == MTAG_ABI_COMPAT && 256204591Sluigi mtag->m_tag_id == PACKET_TAG_DUMMYNET, 257204591Sluigi ("packet on dummynet queue w/o dummynet tag!")); 258204591Sluigi return (struct dn_pkt_tag *)(mtag+1); 259204591Sluigi} 260204591Sluigi 261301772Struckman#ifndef NEW_AQM 262204591Sluigistatic inline void 263204591Sluigimq_append(struct mq *q, struct mbuf *m) 264204591Sluigi{ 265204591Sluigi if (q->head == NULL) 266204591Sluigi q->head = m; 267204591Sluigi else 268204591Sluigi q->tail->m_nextpkt = m; 269204591Sluigi q->tail = m; 270204591Sluigi m->m_nextpkt = NULL; 271204591Sluigi} 272301772Struckman#endif 273204591Sluigi 274204591Sluigi/* 275204591Sluigi * Dispose a list of packet. Use a functions so if we need to do 276204591Sluigi * more work, this is a central point to do it. 277204591Sluigi */ 278204591Sluigivoid dn_free_pkts(struct mbuf *mnext) 279204591Sluigi{ 280204591Sluigi struct mbuf *m; 281204591Sluigi 282204591Sluigi while ((m = mnext) != NULL) { 283204591Sluigi mnext = m->m_nextpkt; 284204591Sluigi FREE_PKT(m); 285204591Sluigi } 286204591Sluigi} 287204591Sluigi 288204591Sluigistatic int 289204591Sluigired_drops (struct dn_queue *q, int len) 290204591Sluigi{ 291204591Sluigi /* 292204591Sluigi * RED algorithm 293204591Sluigi * 294204591Sluigi * RED calculates the average queue size (avg) using a low-pass filter 295204591Sluigi * with an exponential weighted (w_q) moving average: 296204591Sluigi * avg <- (1-w_q) * avg + w_q * q_size 297204591Sluigi * where q_size is the queue length (measured in bytes or * packets). 298204591Sluigi * 299204591Sluigi * If q_size == 0, we compute the idle time for the link, and set 300204591Sluigi * avg = (1 - w_q)^(idle/s) 301204591Sluigi * where s is the time needed for transmitting a medium-sized packet. 302204591Sluigi * 303204591Sluigi * Now, if avg < min_th the packet is enqueued. 304204591Sluigi * If avg > max_th the packet is dropped. Otherwise, the packet is 305204591Sluigi * dropped with probability P function of avg. 306204591Sluigi */ 307204591Sluigi 308204591Sluigi struct dn_fsk *fs = q->fs; 309204591Sluigi int64_t p_b = 0; 310204591Sluigi 311204591Sluigi /* Queue in bytes or packets? */ 312204591Sluigi uint32_t q_size = (fs->fs.flags & DN_QSIZE_BYTES) ? 313204591Sluigi q->ni.len_bytes : q->ni.length; 314204591Sluigi 315204591Sluigi /* Average queue size estimation. */ 316204591Sluigi if (q_size != 0) { 317204591Sluigi /* Queue is not empty, avg <- avg + (q_size - avg) * w_q */ 318204591Sluigi int diff = SCALE(q_size) - q->avg; 319204591Sluigi int64_t v = SCALE_MUL((int64_t)diff, (int64_t)fs->w_q); 320204591Sluigi 321204591Sluigi q->avg += (int)v; 322204591Sluigi } else { 323204591Sluigi /* 324204591Sluigi * Queue is empty, find for how long the queue has been 325204591Sluigi * empty and use a lookup table for computing 326204591Sluigi * (1 - * w_q)^(idle_time/s) where s is the time to send a 327204591Sluigi * (small) packet. 328204591Sluigi * XXX check wraps... 329204591Sluigi */ 330204591Sluigi if (q->avg) { 331204591Sluigi u_int t = div64((dn_cfg.curr_time - q->q_time), fs->lookup_step); 332204591Sluigi 333204591Sluigi q->avg = (t < fs->lookup_depth) ? 334204591Sluigi SCALE_MUL(q->avg, fs->w_q_lookup[t]) : 0; 335204591Sluigi } 336204591Sluigi } 337204591Sluigi 338204591Sluigi /* Should i drop? */ 339204591Sluigi if (q->avg < fs->min_th) { 340204591Sluigi q->count = -1; 341204591Sluigi return (0); /* accept packet */ 342204591Sluigi } 343204591Sluigi if (q->avg >= fs->max_th) { /* average queue >= max threshold */ 344301231Struckman if (fs->fs.flags & DN_IS_ECN) 345301231Struckman return (1); 346204591Sluigi if (fs->fs.flags & DN_IS_GENTLE_RED) { 347204591Sluigi /* 348204591Sluigi * According to Gentle-RED, if avg is greater than 349204591Sluigi * max_th the packet is dropped with a probability 350204591Sluigi * p_b = c_3 * avg - c_4 351204591Sluigi * where c_3 = (1 - max_p) / max_th 352204591Sluigi * c_4 = 1 - 2 * max_p 353204591Sluigi */ 354204591Sluigi p_b = SCALE_MUL((int64_t)fs->c_3, (int64_t)q->avg) - 355204591Sluigi fs->c_4; 356204591Sluigi } else { 357204591Sluigi q->count = -1; 358204591Sluigi return (1); 359204591Sluigi } 360204591Sluigi } else if (q->avg > fs->min_th) { 361301231Struckman if (fs->fs.flags & DN_IS_ECN) 362301231Struckman return (1); 363204591Sluigi /* 364204591Sluigi * We compute p_b using the linear dropping function 365204591Sluigi * p_b = c_1 * avg - c_2 366204591Sluigi * where c_1 = max_p / (max_th - min_th) 367204591Sluigi * c_2 = max_p * min_th / (max_th - min_th) 368204591Sluigi */ 369204591Sluigi p_b = SCALE_MUL((int64_t)fs->c_1, (int64_t)q->avg) - fs->c_2; 370204591Sluigi } 371204591Sluigi 372204591Sluigi if (fs->fs.flags & DN_QSIZE_BYTES) 373204591Sluigi p_b = div64((p_b * len) , fs->max_pkt_size); 374204591Sluigi if (++q->count == 0) 375204591Sluigi q->random = random() & 0xffff; 376204591Sluigi else { 377204591Sluigi /* 378204591Sluigi * q->count counts packets arrived since last drop, so a greater 379204591Sluigi * value of q->count means a greater packet drop probability. 380204591Sluigi */ 381204591Sluigi if (SCALE_MUL(p_b, SCALE((int64_t)q->count)) > q->random) { 382204591Sluigi q->count = 0; 383204591Sluigi /* After a drop we calculate a new random value. */ 384204591Sluigi q->random = random() & 0xffff; 385204591Sluigi return (1); /* drop */ 386204591Sluigi } 387204591Sluigi } 388204591Sluigi /* End of RED algorithm. */ 389204591Sluigi 390204591Sluigi return (0); /* accept */ 391204591Sluigi 392204591Sluigi} 393204591Sluigi 394204591Sluigi/* 395301231Struckman * ECN/ECT Processing (partially adopted from altq) 396301231Struckman */ 397301772Struckman#ifndef NEW_AQM 398301772Struckmanstatic 399301772Struckman#endif 400301772Struckmanint 401301231Struckmanecn_mark(struct mbuf* m) 402301231Struckman{ 403301231Struckman struct ip *ip; 404325731Struckman ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off); 405301231Struckman 406301231Struckman switch (ip->ip_v) { 407301231Struckman case IPVERSION: 408301231Struckman { 409301231Struckman u_int8_t otos; 410301231Struckman int sum; 411301231Struckman 412301231Struckman if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT) 413301231Struckman return (0); /* not-ECT */ 414301231Struckman if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_CE) 415301231Struckman return (1); /* already marked */ 416301231Struckman 417301231Struckman /* 418301231Struckman * ecn-capable but not marked, 419301231Struckman * mark CE and update checksum 420301231Struckman */ 421301231Struckman otos = ip->ip_tos; 422301231Struckman ip->ip_tos |= IPTOS_ECN_CE; 423301231Struckman /* 424301231Struckman * update checksum (from RFC1624) 425301231Struckman * HC' = ~(~HC + ~m + m') 426301231Struckman */ 427301231Struckman sum = ~ntohs(ip->ip_sum) & 0xffff; 428301231Struckman sum += (~otos & 0xffff) + ip->ip_tos; 429301231Struckman sum = (sum >> 16) + (sum & 0xffff); 430301231Struckman sum += (sum >> 16); /* add carry */ 431301231Struckman ip->ip_sum = htons(~sum & 0xffff); 432301231Struckman return (1); 433301231Struckman } 434301231Struckman#ifdef INET6 435301231Struckman case (IPV6_VERSION >> 4): 436301231Struckman { 437325731Struckman struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 438301231Struckman u_int32_t flowlabel; 439301231Struckman 440301231Struckman flowlabel = ntohl(ip6->ip6_flow); 441301231Struckman if ((flowlabel >> 28) != 6) 442301231Struckman return (0); /* version mismatch! */ 443301231Struckman if ((flowlabel & (IPTOS_ECN_MASK << 20)) == 444301231Struckman (IPTOS_ECN_NOTECT << 20)) 445301231Struckman return (0); /* not-ECT */ 446301231Struckman if ((flowlabel & (IPTOS_ECN_MASK << 20)) == 447301231Struckman (IPTOS_ECN_CE << 20)) 448301231Struckman return (1); /* already marked */ 449301231Struckman /* 450301231Struckman * ecn-capable but not marked, mark CE 451301231Struckman */ 452301231Struckman flowlabel |= (IPTOS_ECN_CE << 20); 453301231Struckman ip6->ip6_flow = htonl(flowlabel); 454301231Struckman return (1); 455301231Struckman } 456301231Struckman#endif 457301231Struckman } 458301231Struckman return (0); 459301231Struckman} 460301231Struckman 461301231Struckman/* 462204591Sluigi * Enqueue a packet in q, subject to space and queue management policy 463204591Sluigi * (whose parameters are in q->fs). 464204591Sluigi * Update stats for the queue and the scheduler. 465204591Sluigi * Return 0 on success, 1 on drop. The packet is consumed anyways. 466204591Sluigi */ 467204591Sluigiint 468204591Sluigidn_enqueue(struct dn_queue *q, struct mbuf* m, int drop) 469204591Sluigi{ 470204591Sluigi struct dn_fs *f; 471204591Sluigi struct dn_flow *ni; /* stats for scheduler instance */ 472204591Sluigi uint64_t len; 473204591Sluigi 474204591Sluigi if (q->fs == NULL || q->_si == NULL) { 475204591Sluigi printf("%s fs %p si %p, dropping\n", 476204591Sluigi __FUNCTION__, q->fs, q->_si); 477204591Sluigi FREE_PKT(m); 478204591Sluigi return 1; 479204591Sluigi } 480204591Sluigi f = &(q->fs->fs); 481204591Sluigi ni = &q->_si->ni; 482204591Sluigi len = m->m_pkthdr.len; 483204591Sluigi /* Update statistics, then check reasons to drop pkt. */ 484204591Sluigi q->ni.tot_bytes += len; 485204591Sluigi q->ni.tot_pkts++; 486204591Sluigi ni->tot_bytes += len; 487204591Sluigi ni->tot_pkts++; 488204591Sluigi if (drop) 489204591Sluigi goto drop; 490204591Sluigi if (f->plr && random() < f->plr) 491204591Sluigi goto drop; 492301772Struckman#ifdef NEW_AQM 493301772Struckman /* Call AQM enqueue function */ 494301772Struckman if (q->fs->aqmfp) 495301772Struckman return q->fs->aqmfp->enqueue(q ,m); 496301772Struckman#endif 497301231Struckman if (f->flags & DN_IS_RED && red_drops(q, m->m_pkthdr.len)) { 498301231Struckman if (!(f->flags & DN_IS_ECN) || !ecn_mark(m)) 499301231Struckman goto drop; 500301231Struckman } 501204591Sluigi if (f->flags & DN_QSIZE_BYTES) { 502204591Sluigi if (q->ni.len_bytes > f->qsize) 503204591Sluigi goto drop; 504204591Sluigi } else if (q->ni.length >= f->qsize) { 505204591Sluigi goto drop; 506204591Sluigi } 507204591Sluigi mq_append(&q->mq, m); 508204591Sluigi q->ni.length++; 509204591Sluigi q->ni.len_bytes += len; 510204591Sluigi ni->length++; 511204591Sluigi ni->len_bytes += len; 512301231Struckman return (0); 513204591Sluigi 514204591Sluigidrop: 515204591Sluigi io_pkt_drop++; 516204591Sluigi q->ni.drops++; 517204591Sluigi ni->drops++; 518204591Sluigi FREE_PKT(m); 519301231Struckman return (1); 520204591Sluigi} 521204591Sluigi 522204591Sluigi/* 523204591Sluigi * Fetch packets from the delay line which are due now. If there are 524204591Sluigi * leftover packets, reinsert the delay line in the heap. 525204591Sluigi * Runs under scheduler lock. 526204591Sluigi */ 527204591Sluigistatic void 528204591Sluigitransmit_event(struct mq *q, struct delay_line *dline, uint64_t now) 529204591Sluigi{ 530204591Sluigi struct mbuf *m; 531204591Sluigi struct dn_pkt_tag *pkt = NULL; 532204591Sluigi 533204591Sluigi dline->oid.subtype = 0; /* not in heap */ 534204591Sluigi while ((m = dline->mq.head) != NULL) { 535204591Sluigi pkt = dn_tag_get(m); 536204591Sluigi if (!DN_KEY_LEQ(pkt->output_time, now)) 537204591Sluigi break; 538204591Sluigi dline->mq.head = m->m_nextpkt; 539204591Sluigi mq_append(q, m); 540204591Sluigi } 541204591Sluigi if (m != NULL) { 542204591Sluigi dline->oid.subtype = 1; /* in heap */ 543204591Sluigi heap_insert(&dn_cfg.evheap, pkt->output_time, dline); 544204591Sluigi } 545204591Sluigi} 546204591Sluigi 547204591Sluigi/* 548204591Sluigi * Convert the additional MAC overheads/delays into an equivalent 549204591Sluigi * number of bits for the given data rate. The samples are 550204591Sluigi * in milliseconds so we need to divide by 1000. 551204591Sluigi */ 552204591Sluigistatic uint64_t 553204591Sluigiextra_bits(struct mbuf *m, struct dn_schk *s) 554204591Sluigi{ 555204591Sluigi int index; 556204591Sluigi uint64_t bits; 557204591Sluigi struct dn_profile *pf = s->profile; 558204591Sluigi 559204591Sluigi if (!pf || pf->samples_no == 0) 560204591Sluigi return 0; 561204591Sluigi index = random() % pf->samples_no; 562204591Sluigi bits = div64((uint64_t)pf->samples[index] * s->link.bandwidth, 1000); 563204591Sluigi if (index >= pf->loss_level) { 564204591Sluigi struct dn_pkt_tag *dt = dn_tag_get(m); 565204591Sluigi if (dt) 566204591Sluigi dt->dn_dir = DIR_DROP; 567204591Sluigi } 568204591Sluigi return bits; 569204591Sluigi} 570204591Sluigi 571204591Sluigi/* 572204591Sluigi * Send traffic from a scheduler instance due by 'now'. 573204591Sluigi * Return a pointer to the head of the queue. 574204591Sluigi */ 575204591Sluigistatic struct mbuf * 576204591Sluigiserve_sched(struct mq *q, struct dn_sch_inst *si, uint64_t now) 577204591Sluigi{ 578204591Sluigi struct mq def_q; 579204591Sluigi struct dn_schk *s = si->sched; 580204591Sluigi struct mbuf *m = NULL; 581204591Sluigi int delay_line_idle = (si->dline.mq.head == NULL); 582204591Sluigi int done, bw; 583204591Sluigi 584204591Sluigi if (q == NULL) { 585204591Sluigi q = &def_q; 586204591Sluigi q->head = NULL; 587204591Sluigi } 588204591Sluigi 589204591Sluigi bw = s->link.bandwidth; 590204591Sluigi si->kflags &= ~DN_ACTIVE; 591204591Sluigi 592204591Sluigi if (bw > 0) 593204591Sluigi si->credit += (now - si->sched_time) * bw; 594204591Sluigi else 595204591Sluigi si->credit = 0; 596204591Sluigi si->sched_time = now; 597204591Sluigi done = 0; 598204591Sluigi while (si->credit >= 0 && (m = s->fp->dequeue(si)) != NULL) { 599204591Sluigi uint64_t len_scaled; 600213267Sluigi 601204591Sluigi done++; 602204591Sluigi len_scaled = (bw == 0) ? 0 : hz * 603213267Sluigi (m->m_pkthdr.len * 8 + extra_bits(m, s)); 604204591Sluigi si->credit -= len_scaled; 605204591Sluigi /* Move packet in the delay line */ 606218360Sluigi dn_tag_get(m)->output_time = dn_cfg.curr_time + s->link.delay ; 607204591Sluigi mq_append(&si->dline.mq, m); 608204591Sluigi } 609213267Sluigi 610204591Sluigi /* 611204591Sluigi * If credit >= 0 the instance is idle, mark time. 612204591Sluigi * Otherwise put back in the heap, and adjust the output 613204591Sluigi * time of the last inserted packet, m, which was too early. 614204591Sluigi */ 615204591Sluigi if (si->credit >= 0) { 616204591Sluigi si->idle_time = now; 617204591Sluigi } else { 618204591Sluigi uint64_t t; 619204591Sluigi KASSERT (bw > 0, ("bw=0 and credit<0 ?")); 620204591Sluigi t = div64(bw - 1 - si->credit, bw); 621204591Sluigi if (m) 622204591Sluigi dn_tag_get(m)->output_time += t; 623204591Sluigi si->kflags |= DN_ACTIVE; 624204591Sluigi heap_insert(&dn_cfg.evheap, now + t, si); 625204591Sluigi } 626204591Sluigi if (delay_line_idle && done) 627204591Sluigi transmit_event(q, &si->dline, now); 628204591Sluigi return q->head; 629204591Sluigi} 630204591Sluigi 631204591Sluigi/* 632204591Sluigi * The timer handler for dummynet. Time is computed in ticks, but 633204591Sluigi * but the code is tolerant to the actual rate at which this is called. 634204591Sluigi * Once complete, the function reschedules itself for the next tick. 635204591Sluigi */ 636204591Sluigivoid 637204591Sluigidummynet_task(void *context, int pending) 638204591Sluigi{ 639204591Sluigi struct timeval t; 640204591Sluigi struct mq q = { NULL, NULL }; /* queue to accumulate results */ 641204591Sluigi 642206461Sbz CURVNET_SET((struct vnet *)context); 643206428Sluigi 644204591Sluigi DN_BH_WLOCK(); 645204591Sluigi 646204591Sluigi /* Update number of lost(coalesced) ticks. */ 647204591Sluigi tick_lost += pending - 1; 648204591Sluigi 649204591Sluigi getmicrouptime(&t); 650204591Sluigi /* Last tick duration (usec). */ 651204591Sluigi tick_last = (t.tv_sec - dn_cfg.prev_t.tv_sec) * 1000000 + 652204591Sluigi (t.tv_usec - dn_cfg.prev_t.tv_usec); 653204591Sluigi /* Last tick vs standard tick difference (usec). */ 654204591Sluigi tick_delta = (tick_last * hz - 1000000) / hz; 655204591Sluigi /* Accumulated tick difference (usec). */ 656204591Sluigi tick_delta_sum += tick_delta; 657204591Sluigi 658204591Sluigi dn_cfg.prev_t = t; 659204591Sluigi 660204591Sluigi /* 661204591Sluigi * Adjust curr_time if the accumulated tick difference is 662204591Sluigi * greater than the 'standard' tick. Since curr_time should 663204591Sluigi * be monotonically increasing, we do positive adjustments 664204591Sluigi * as required, and throttle curr_time in case of negative 665204591Sluigi * adjustment. 666204591Sluigi */ 667204591Sluigi dn_cfg.curr_time++; 668204591Sluigi if (tick_delta_sum - tick >= 0) { 669204591Sluigi int diff = tick_delta_sum / tick; 670204591Sluigi 671204591Sluigi dn_cfg.curr_time += diff; 672204591Sluigi tick_diff += diff; 673204591Sluigi tick_delta_sum %= tick; 674204591Sluigi tick_adjustment++; 675204591Sluigi } else if (tick_delta_sum + tick <= 0) { 676204591Sluigi dn_cfg.curr_time--; 677204591Sluigi tick_diff--; 678204591Sluigi tick_delta_sum += tick; 679204591Sluigi tick_adjustment++; 680204591Sluigi } 681204591Sluigi 682204591Sluigi /* serve pending events, accumulate in q */ 683204591Sluigi for (;;) { 684204591Sluigi struct dn_id *p; /* generic parameter to handler */ 685204591Sluigi 686204591Sluigi if (dn_cfg.evheap.elements == 0 || 687204591Sluigi DN_KEY_LT(dn_cfg.curr_time, HEAP_TOP(&dn_cfg.evheap)->key)) 688204591Sluigi break; 689204591Sluigi p = HEAP_TOP(&dn_cfg.evheap)->object; 690204591Sluigi heap_extract(&dn_cfg.evheap, NULL); 691204591Sluigi 692204591Sluigi if (p->type == DN_SCH_I) { 693204591Sluigi serve_sched(&q, (struct dn_sch_inst *)p, dn_cfg.curr_time); 694204591Sluigi } else { /* extracted a delay line */ 695204591Sluigi transmit_event(&q, (struct delay_line *)p, dn_cfg.curr_time); 696204591Sluigi } 697204591Sluigi } 698205173Sluigi if (dn_cfg.expire && ++dn_cfg.expire_cycle >= dn_cfg.expire) { 699205173Sluigi dn_cfg.expire_cycle = 0; 700205173Sluigi dn_drain_scheduler(); 701205173Sluigi dn_drain_queue(); 702205173Sluigi } 703204591Sluigi 704297228Shselasky dn_reschedule(); 705204591Sluigi DN_BH_WUNLOCK(); 706204591Sluigi if (q.head != NULL) 707204591Sluigi dummynet_send(q.head); 708206428Sluigi CURVNET_RESTORE(); 709204591Sluigi} 710204591Sluigi 711204591Sluigi/* 712204591Sluigi * forward a chain of packets to the proper destination. 713204591Sluigi * This runs outside the dummynet lock. 714204591Sluigi */ 715204591Sluigistatic void 716204591Sluigidummynet_send(struct mbuf *m) 717204591Sluigi{ 718204591Sluigi struct mbuf *n; 719204591Sluigi 720204591Sluigi for (; m != NULL; m = n) { 721204591Sluigi struct ifnet *ifp = NULL; /* gcc 3.4.6 complains */ 722204591Sluigi struct m_tag *tag; 723204591Sluigi int dst; 724204591Sluigi 725204591Sluigi n = m->m_nextpkt; 726204591Sluigi m->m_nextpkt = NULL; 727204591Sluigi tag = m_tag_first(m); 728204591Sluigi if (tag == NULL) { /* should not happen */ 729204591Sluigi dst = DIR_DROP; 730204591Sluigi } else { 731204591Sluigi struct dn_pkt_tag *pkt = dn_tag_get(m); 732204591Sluigi /* extract the dummynet info, rename the tag 733204591Sluigi * to carry reinject info. 734204591Sluigi */ 735204591Sluigi dst = pkt->dn_dir; 736204591Sluigi ifp = pkt->ifp; 737204591Sluigi tag->m_tag_cookie = MTAG_IPFW_RULE; 738204591Sluigi tag->m_tag_id = 0; 739204591Sluigi } 740204591Sluigi 741204591Sluigi switch (dst) { 742204591Sluigi case DIR_OUT: 743204591Sluigi ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL); 744204591Sluigi break ; 745204591Sluigi 746204591Sluigi case DIR_IN : 747204591Sluigi netisr_dispatch(NETISR_IP, m); 748204591Sluigi break; 749204591Sluigi 750204591Sluigi#ifdef INET6 751204591Sluigi case DIR_IN | PROTO_IPV6: 752204591Sluigi netisr_dispatch(NETISR_IPV6, m); 753204591Sluigi break; 754204591Sluigi 755204591Sluigi case DIR_OUT | PROTO_IPV6: 756204591Sluigi ip6_output(m, NULL, NULL, IPV6_FORWARDING, NULL, NULL, NULL); 757204591Sluigi break; 758204591Sluigi#endif 759204591Sluigi 760204591Sluigi case DIR_FWD | PROTO_IFB: /* DN_TO_IFB_FWD: */ 761204591Sluigi if (bridge_dn_p != NULL) 762204591Sluigi ((*bridge_dn_p)(m, ifp)); 763204591Sluigi else 764204591Sluigi printf("dummynet: if_bridge not loaded\n"); 765204591Sluigi 766204591Sluigi break; 767204591Sluigi 768204591Sluigi case DIR_IN | PROTO_LAYER2: /* DN_TO_ETH_DEMUX: */ 769204591Sluigi /* 770204591Sluigi * The Ethernet code assumes the Ethernet header is 771204591Sluigi * contiguous in the first mbuf header. 772204591Sluigi * Insure this is true. 773204591Sluigi */ 774204591Sluigi if (m->m_len < ETHER_HDR_LEN && 775204591Sluigi (m = m_pullup(m, ETHER_HDR_LEN)) == NULL) { 776204591Sluigi printf("dummynet/ether: pullup failed, " 777204591Sluigi "dropping packet\n"); 778204591Sluigi break; 779204591Sluigi } 780204591Sluigi ether_demux(m->m_pkthdr.rcvif, m); 781204591Sluigi break; 782204591Sluigi 783204591Sluigi case DIR_OUT | PROTO_LAYER2: /* N_TO_ETH_OUT: */ 784204591Sluigi ether_output_frame(ifp, m); 785204591Sluigi break; 786204591Sluigi 787204591Sluigi case DIR_DROP: 788204591Sluigi /* drop the packet after some time */ 789204591Sluigi FREE_PKT(m); 790204591Sluigi break; 791204591Sluigi 792204591Sluigi default: 793204591Sluigi printf("dummynet: bad switch %d!\n", dst); 794204591Sluigi FREE_PKT(m); 795204591Sluigi break; 796204591Sluigi } 797204591Sluigi } 798204591Sluigi} 799204591Sluigi 800204591Sluigistatic inline int 801204591Sluigitag_mbuf(struct mbuf *m, int dir, struct ip_fw_args *fwa) 802204591Sluigi{ 803204591Sluigi struct dn_pkt_tag *dt; 804204591Sluigi struct m_tag *mtag; 805204591Sluigi 806204591Sluigi mtag = m_tag_get(PACKET_TAG_DUMMYNET, 807204591Sluigi sizeof(*dt), M_NOWAIT | M_ZERO); 808204591Sluigi if (mtag == NULL) 809204591Sluigi return 1; /* Cannot allocate packet header. */ 810204591Sluigi m_tag_prepend(m, mtag); /* Attach to mbuf chain. */ 811204591Sluigi dt = (struct dn_pkt_tag *)(mtag + 1); 812204591Sluigi dt->rule = fwa->rule; 813204591Sluigi dt->rule.info &= IPFW_ONEPASS; /* only keep this info */ 814204591Sluigi dt->dn_dir = dir; 815204591Sluigi dt->ifp = fwa->oif; 816204591Sluigi /* dt->output tame is updated as we move through */ 817204591Sluigi dt->output_time = dn_cfg.curr_time; 818325731Struckman dt->iphdr_off = (dir & PROTO_LAYER2) ? ETHER_HDR_LEN : 0; 819204591Sluigi return 0; 820204591Sluigi} 821204591Sluigi 822204591Sluigi 823204591Sluigi/* 824204591Sluigi * dummynet hook for packets. 825204591Sluigi * We use the argument to locate the flowset fs and the sched_set sch 826204591Sluigi * associated to it. The we apply flow_mask and sched_mask to 827204591Sluigi * determine the queue and scheduler instances. 828204591Sluigi * 829204591Sluigi * dir where shall we send the packet after dummynet. 830204591Sluigi * *m0 the mbuf with the packet 831204591Sluigi * ifp the 'ifp' parameter from the caller. 832204591Sluigi * NULL in ip_input, destination interface in ip_output, 833204591Sluigi */ 834204591Sluigiint 835204591Sluigidummynet_io(struct mbuf **m0, int dir, struct ip_fw_args *fwa) 836204591Sluigi{ 837204591Sluigi struct mbuf *m = *m0; 838204591Sluigi struct dn_fsk *fs = NULL; 839204591Sluigi struct dn_sch_inst *si; 840204591Sluigi struct dn_queue *q = NULL; /* default */ 841204591Sluigi 842204591Sluigi int fs_id = (fwa->rule.info & IPFW_INFO_MASK) + 843204591Sluigi ((fwa->rule.info & IPFW_IS_PIPE) ? 2*DN_MAX_ID : 0); 844204591Sluigi DN_BH_WLOCK(); 845204591Sluigi io_pkt++; 846204591Sluigi /* we could actually tag outside the lock, but who cares... */ 847204591Sluigi if (tag_mbuf(m, dir, fwa)) 848204591Sluigi goto dropit; 849204591Sluigi if (dn_cfg.busy) { 850204591Sluigi /* if the upper half is busy doing something expensive, 851204591Sluigi * lets queue the packet and move forward 852204591Sluigi */ 853204591Sluigi mq_append(&dn_cfg.pending, m); 854204591Sluigi m = *m0 = NULL; /* consumed */ 855204591Sluigi goto done; /* already active, nothing to do */ 856204591Sluigi } 857204591Sluigi /* XXX locate_flowset could be optimised with a direct ref. */ 858204591Sluigi fs = dn_ht_find(dn_cfg.fshash, fs_id, 0, NULL); 859204591Sluigi if (fs == NULL) 860204591Sluigi goto dropit; /* This queue/pipe does not exist! */ 861204591Sluigi if (fs->sched == NULL) /* should not happen */ 862204591Sluigi goto dropit; 863204591Sluigi /* find scheduler instance, possibly applying sched_mask */ 864204591Sluigi si = ipdn_si_find(fs->sched, &(fwa->f_id)); 865204591Sluigi if (si == NULL) 866204591Sluigi goto dropit; 867204591Sluigi /* 868204591Sluigi * If the scheduler supports multiple queues, find the right one 869204591Sluigi * (otherwise it will be ignored by enqueue). 870204591Sluigi */ 871204591Sluigi if (fs->sched->fp->flags & DN_MULTIQUEUE) { 872204591Sluigi q = ipdn_q_find(fs, si, &(fwa->f_id)); 873204591Sluigi if (q == NULL) 874204591Sluigi goto dropit; 875204591Sluigi } 876204591Sluigi if (fs->sched->fp->enqueue(si, q, m)) { 877204591Sluigi /* packet was dropped by enqueue() */ 878204591Sluigi m = *m0 = NULL; 879301772Struckman 880301772Struckman /* dn_enqueue already increases io_pkt_drop */ 881301772Struckman io_pkt_drop--; 882301772Struckman 883204591Sluigi goto dropit; 884204591Sluigi } 885204591Sluigi 886204591Sluigi if (si->kflags & DN_ACTIVE) { 887204591Sluigi m = *m0 = NULL; /* consumed */ 888204591Sluigi goto done; /* already active, nothing to do */ 889204591Sluigi } 890204591Sluigi 891204591Sluigi /* compute the initial allowance */ 892213265Sluigi if (si->idle_time < dn_cfg.curr_time) { 893213265Sluigi /* Do this only on the first packet on an idle pipe */ 894204591Sluigi struct dn_link *p = &fs->sched->link; 895213265Sluigi 896213329Sluigi si->sched_time = dn_cfg.curr_time; 897204591Sluigi si->credit = dn_cfg.io_fast ? p->bandwidth : 0; 898204591Sluigi if (p->burst) { 899204591Sluigi uint64_t burst = (dn_cfg.curr_time - si->idle_time) * p->bandwidth; 900204591Sluigi if (burst > p->burst) 901204591Sluigi burst = p->burst; 902204591Sluigi si->credit += burst; 903204591Sluigi } 904204591Sluigi } 905204591Sluigi /* pass through scheduler and delay line */ 906204591Sluigi m = serve_sched(NULL, si, dn_cfg.curr_time); 907204591Sluigi 908204591Sluigi /* optimization -- pass it back to ipfw for immediate send */ 909204591Sluigi /* XXX Don't call dummynet_send() if scheduler return the packet 910204591Sluigi * just enqueued. This avoid a lock order reversal. 911204591Sluigi * 912204591Sluigi */ 913204591Sluigi if (/*dn_cfg.io_fast &&*/ m == *m0 && (dir & PROTO_LAYER2) == 0 ) { 914205602Sluigi /* fast io, rename the tag * to carry reinject info. */ 915205602Sluigi struct m_tag *tag = m_tag_first(m); 916205602Sluigi 917205602Sluigi tag->m_tag_cookie = MTAG_IPFW_RULE; 918205602Sluigi tag->m_tag_id = 0; 919204591Sluigi io_pkt_fast++; 920204591Sluigi if (m->m_nextpkt != NULL) { 921204591Sluigi printf("dummynet: fast io: pkt chain detected!\n"); 922204591Sluigi m->m_nextpkt = NULL; 923204591Sluigi } 924204591Sluigi m = NULL; 925204591Sluigi } else { 926204591Sluigi *m0 = NULL; 927204591Sluigi } 928204591Sluigidone: 929204591Sluigi DN_BH_WUNLOCK(); 930204591Sluigi if (m) 931204591Sluigi dummynet_send(m); 932204591Sluigi return 0; 933204591Sluigi 934204591Sluigidropit: 935204591Sluigi io_pkt_drop++; 936204591Sluigi DN_BH_WUNLOCK(); 937204591Sluigi if (m) 938204591Sluigi FREE_PKT(m); 939204591Sluigi *m0 = NULL; 940204591Sluigi return (fs && (fs->fs.flags & DN_NOERROR)) ? 0 : ENOBUFS; 941204591Sluigi} 942