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freebsd-nq/sys/netpfil/ipfw/ip_dn_io.c
Pawel Biernacki 7029da5c36 Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE.  All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by:	kib (mentor, blanket)
Commented by:	kib, gallatin, melifaro
Differential Revision:	https://reviews.freebsd.org/D23718
2020-02-26 14:26:36 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2010 Luigi Rizzo, Riccardo Panicucci, Universita` di Pisa
* All rights reserved
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Dummynet portions related to packet handling.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <net/if.h> /* IFNAMSIZ, struct ifaddr, ifq head, lock.h mutex.h */
#include <net/if_var.h> /* NET_EPOCH_... */
#include <net/netisr.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/ip.h> /* ip_len, ip_off */
#include <netinet/ip_var.h> /* ip_output(), IP_FORWARDING */
#include <netinet/ip_fw.h>
#include <netinet/ip_dummynet.h>
#include <netinet/if_ether.h> /* various ether_* routines */
#include <netinet/ip6.h> /* for ip6_input, ip6_output prototypes */
#include <netinet6/ip6_var.h>
#include <netpfil/ipfw/ip_fw_private.h>
#include <netpfil/ipfw/dn_heap.h>
#include <netpfil/ipfw/ip_dn_private.h>
#ifdef NEW_AQM
#include <netpfil/ipfw/dn_aqm.h>
#endif
#include <netpfil/ipfw/dn_sched.h>
/*
* We keep a private variable for the simulation time, but we could
* probably use an existing one ("softticks" in sys/kern/kern_timeout.c)
* instead of dn_cfg.curr_time
*/
struct dn_parms dn_cfg;
//VNET_DEFINE(struct dn_parms, _base_dn_cfg);
static long tick_last; /* Last tick duration (usec). */
static long tick_delta; /* Last vs standard tick diff (usec). */
static long tick_delta_sum; /* Accumulated tick difference (usec).*/
static long tick_adjustment; /* Tick adjustments done. */
static long tick_lost; /* Lost(coalesced) ticks number. */
/* Adjusted vs non-adjusted curr_time difference (ticks). */
static long tick_diff;
static unsigned long io_pkt;
static unsigned long io_pkt_fast;
#ifdef NEW_AQM
unsigned long io_pkt_drop;
#else
static unsigned long io_pkt_drop;
#endif
/*
* We use a heap to store entities for which we have pending timer events.
* The heap is checked at every tick and all entities with expired events
* are extracted.
*/
MALLOC_DEFINE(M_DUMMYNET, "dummynet", "dummynet heap");
extern void (*bridge_dn_p)(struct mbuf *, struct ifnet *);
#ifdef SYSCTL_NODE
/*
* Because of the way the SYSBEGIN/SYSEND macros work on other
* platforms, there should not be functions between them.
* So keep the handlers outside the block.
*/
static int
sysctl_hash_size(SYSCTL_HANDLER_ARGS)
{
int error, value;
value = dn_cfg.hash_size;
error = sysctl_handle_int(oidp, &value, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (value < 16 || value > 65536)
return (EINVAL);
dn_cfg.hash_size = value;
return (0);
}
static int
sysctl_limits(SYSCTL_HANDLER_ARGS)
{
int error;
long value;
if (arg2 != 0)
value = dn_cfg.slot_limit;
else
value = dn_cfg.byte_limit;
error = sysctl_handle_long(oidp, &value, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (arg2 != 0) {
if (value < 1)
return (EINVAL);
dn_cfg.slot_limit = value;
} else {
if (value < 1500)
return (EINVAL);
dn_cfg.byte_limit = value;
}
return (0);
}
SYSBEGIN(f4)
SYSCTL_DECL(_net_inet);
SYSCTL_DECL(_net_inet_ip);
#ifdef NEW_AQM
SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Dummynet");
#else
static SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Dummynet");
#endif
/* wrapper to pass dn_cfg fields to SYSCTL_* */
//#define DC(x) (&(VNET_NAME(_base_dn_cfg).x))
#define DC(x) (&(dn_cfg.x))
/* parameters */
SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, hash_size,
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
0, 0, sysctl_hash_size, "I",
"Default hash table size");
SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_slot_limit,
CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
0, 1, sysctl_limits, "L",
"Upper limit in slots for pipe queue.");
SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_byte_limit,
CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
0, 0, sysctl_limits, "L",
"Upper limit in bytes for pipe queue.");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, io_fast,
CTLFLAG_RW, DC(io_fast), 0, "Enable fast dummynet io.");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug,
CTLFLAG_RW, DC(debug), 0, "Dummynet debug level");
/* RED parameters */
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_lookup_depth,
CTLFLAG_RD, DC(red_lookup_depth), 0, "Depth of RED lookup table");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_avg_pkt_size,
CTLFLAG_RD, DC(red_avg_pkt_size), 0, "RED Medium packet size");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_max_pkt_size,
CTLFLAG_RD, DC(red_max_pkt_size), 0, "RED Max packet size");
/* time adjustment */
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta,
CTLFLAG_RD, &tick_delta, 0, "Last vs standard tick difference (usec).");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta_sum,
CTLFLAG_RD, &tick_delta_sum, 0, "Accumulated tick difference (usec).");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_adjustment,
CTLFLAG_RD, &tick_adjustment, 0, "Tick adjustments done.");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_diff,
CTLFLAG_RD, &tick_diff, 0,
"Adjusted vs non-adjusted curr_time difference (ticks).");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_lost,
CTLFLAG_RD, &tick_lost, 0,
"Number of ticks coalesced by dummynet taskqueue.");
/* Drain parameters */
SYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire,
CTLFLAG_RW, DC(expire), 0, "Expire empty queues/pipes");
SYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire_cycle,
CTLFLAG_RD, DC(expire_cycle), 0, "Expire cycle for queues/pipes");
/* statistics */
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, schk_count,
CTLFLAG_RD, DC(schk_count), 0, "Number of schedulers");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, si_count,
CTLFLAG_RD, DC(si_count), 0, "Number of scheduler instances");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, fsk_count,
CTLFLAG_RD, DC(fsk_count), 0, "Number of flowsets");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, queue_count,
CTLFLAG_RD, DC(queue_count), 0, "Number of queues");
SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt,
CTLFLAG_RD, &io_pkt, 0,
"Number of packets passed to dummynet.");
SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_fast,
CTLFLAG_RD, &io_pkt_fast, 0,
"Number of packets bypassed dummynet scheduler.");
SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_drop,
CTLFLAG_RD, &io_pkt_drop, 0,
"Number of packets dropped by dummynet.");
#undef DC
SYSEND
#endif
static void dummynet_send(struct mbuf *);
/*
* Return the mbuf tag holding the dummynet state (it should
* be the first one on the list).
*/
struct dn_pkt_tag *
dn_tag_get(struct mbuf *m)
{
struct m_tag *mtag = m_tag_first(m);
#ifdef NEW_AQM
/* XXX: to skip ts m_tag. For Debugging only*/
if (mtag != NULL && mtag->m_tag_id == DN_AQM_MTAG_TS) {
m_tag_delete(m,mtag);
mtag = m_tag_first(m);
D("skip TS tag");
}
#endif
KASSERT(mtag != NULL &&
mtag->m_tag_cookie == MTAG_ABI_COMPAT &&
mtag->m_tag_id == PACKET_TAG_DUMMYNET,
("packet on dummynet queue w/o dummynet tag!"));
return (struct dn_pkt_tag *)(mtag+1);
}
#ifndef NEW_AQM
static inline void
mq_append(struct mq *q, struct mbuf *m)
{
#ifdef USERSPACE
// buffers from netmap need to be copied
// XXX note that the routine is not expected to fail
ND("append %p to %p", m, q);
if (m->m_flags & M_STACK) {
struct mbuf *m_new;
void *p;
int l, ofs;
ofs = m->m_data - m->__m_extbuf;
// XXX allocate
MGETHDR(m_new, M_NOWAIT, MT_DATA);
ND("*** WARNING, volatile buf %p ext %p %d dofs %d m_new %p",
m, m->__m_extbuf, m->__m_extlen, ofs, m_new);
p = m_new->__m_extbuf; /* new pointer */
l = m_new->__m_extlen; /* new len */
if (l <= m->__m_extlen) {
panic("extlen too large");
}
*m_new = *m; // copy
m_new->m_flags &= ~M_STACK;
m_new->__m_extbuf = p; // point to new buffer
_pkt_copy(m->__m_extbuf, p, m->__m_extlen);
m_new->m_data = p + ofs;
m = m_new;
}
#endif /* USERSPACE */
if (q->head == NULL)
q->head = m;
else
q->tail->m_nextpkt = m;
q->count++;
q->tail = m;
m->m_nextpkt = NULL;
}
#endif
/*
* Dispose a list of packet. Use a functions so if we need to do
* more work, this is a central point to do it.
*/
void dn_free_pkts(struct mbuf *mnext)
{
struct mbuf *m;
while ((m = mnext) != NULL) {
mnext = m->m_nextpkt;
FREE_PKT(m);
}
}
static int
red_drops (struct dn_queue *q, int len)
{
/*
* RED algorithm
*
* RED calculates the average queue size (avg) using a low-pass filter
* with an exponential weighted (w_q) moving average:
* avg <- (1-w_q) * avg + w_q * q_size
* where q_size is the queue length (measured in bytes or * packets).
*
* If q_size == 0, we compute the idle time for the link, and set
* avg = (1 - w_q)^(idle/s)
* where s is the time needed for transmitting a medium-sized packet.
*
* Now, if avg < min_th the packet is enqueued.
* If avg > max_th the packet is dropped. Otherwise, the packet is
* dropped with probability P function of avg.
*/
struct dn_fsk *fs = q->fs;
int64_t p_b = 0;
/* Queue in bytes or packets? */
uint32_t q_size = (fs->fs.flags & DN_QSIZE_BYTES) ?
q->ni.len_bytes : q->ni.length;
/* Average queue size estimation. */
if (q_size != 0) {
/* Queue is not empty, avg <- avg + (q_size - avg) * w_q */
int diff = SCALE(q_size) - q->avg;
int64_t v = SCALE_MUL((int64_t)diff, (int64_t)fs->w_q);
q->avg += (int)v;
} else {
/*
* Queue is empty, find for how long the queue has been
* empty and use a lookup table for computing
* (1 - * w_q)^(idle_time/s) where s is the time to send a
* (small) packet.
* XXX check wraps...
*/
if (q->avg) {
u_int t = div64((dn_cfg.curr_time - q->q_time), fs->lookup_step);
q->avg = (t < fs->lookup_depth) ?
SCALE_MUL(q->avg, fs->w_q_lookup[t]) : 0;
}
}
/* Should i drop? */
if (q->avg < fs->min_th) {
q->count = -1;
return (0); /* accept packet */
}
if (q->avg >= fs->max_th) { /* average queue >= max threshold */
if (fs->fs.flags & DN_IS_ECN)
return (1);
if (fs->fs.flags & DN_IS_GENTLE_RED) {
/*
* According to Gentle-RED, if avg is greater than
* max_th the packet is dropped with a probability
* p_b = c_3 * avg - c_4
* where c_3 = (1 - max_p) / max_th
* c_4 = 1 - 2 * max_p
*/
p_b = SCALE_MUL((int64_t)fs->c_3, (int64_t)q->avg) -
fs->c_4;
} else {
q->count = -1;
return (1);
}
} else if (q->avg > fs->min_th) {
if (fs->fs.flags & DN_IS_ECN)
return (1);
/*
* We compute p_b using the linear dropping function
* p_b = c_1 * avg - c_2
* where c_1 = max_p / (max_th - min_th)
* c_2 = max_p * min_th / (max_th - min_th)
*/
p_b = SCALE_MUL((int64_t)fs->c_1, (int64_t)q->avg) - fs->c_2;
}
if (fs->fs.flags & DN_QSIZE_BYTES)
p_b = div64((p_b * len) , fs->max_pkt_size);
if (++q->count == 0)
q->random = random() & 0xffff;
else {
/*
* q->count counts packets arrived since last drop, so a greater
* value of q->count means a greater packet drop probability.
*/
if (SCALE_MUL(p_b, SCALE((int64_t)q->count)) > q->random) {
q->count = 0;
/* After a drop we calculate a new random value. */
q->random = random() & 0xffff;
return (1); /* drop */
}
}
/* End of RED algorithm. */
return (0); /* accept */
}
/*
* ECN/ECT Processing (partially adopted from altq)
*/
#ifndef NEW_AQM
static
#endif
int
ecn_mark(struct mbuf* m)
{
struct ip *ip;
ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off);
switch (ip->ip_v) {
case IPVERSION:
{
uint16_t old;
if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT)
return (0); /* not-ECT */
if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_CE)
return (1); /* already marked */
/*
* ecn-capable but not marked,
* mark CE and update checksum
*/
old = *(uint16_t *)ip;
ip->ip_tos |= IPTOS_ECN_CE;
ip->ip_sum = cksum_adjust(ip->ip_sum, old, *(uint16_t *)ip);
return (1);
}
#ifdef INET6
case (IPV6_VERSION >> 4):
{
struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
u_int32_t flowlabel;
flowlabel = ntohl(ip6->ip6_flow);
if ((flowlabel >> 28) != 6)
return (0); /* version mismatch! */
if ((flowlabel & (IPTOS_ECN_MASK << 20)) ==
(IPTOS_ECN_NOTECT << 20))
return (0); /* not-ECT */
if ((flowlabel & (IPTOS_ECN_MASK << 20)) ==
(IPTOS_ECN_CE << 20))
return (1); /* already marked */
/*
* ecn-capable but not marked, mark CE
*/
flowlabel |= (IPTOS_ECN_CE << 20);
ip6->ip6_flow = htonl(flowlabel);
return (1);
}
#endif
}
return (0);
}
/*
* Enqueue a packet in q, subject to space and queue management policy
* (whose parameters are in q->fs).
* Update stats for the queue and the scheduler.
* Return 0 on success, 1 on drop. The packet is consumed anyways.
*/
int
dn_enqueue(struct dn_queue *q, struct mbuf* m, int drop)
{
struct dn_fs *f;
struct dn_flow *ni; /* stats for scheduler instance */
uint64_t len;
if (q->fs == NULL || q->_si == NULL) {
printf("%s fs %p si %p, dropping\n",
__FUNCTION__, q->fs, q->_si);
FREE_PKT(m);
return 1;
}
f = &(q->fs->fs);
ni = &q->_si->ni;
len = m->m_pkthdr.len;
/* Update statistics, then check reasons to drop pkt. */
q->ni.tot_bytes += len;
q->ni.tot_pkts++;
ni->tot_bytes += len;
ni->tot_pkts++;
if (drop)
goto drop;
if (f->plr && random() < f->plr)
goto drop;
#ifdef NEW_AQM
/* Call AQM enqueue function */
if (q->fs->aqmfp)
return q->fs->aqmfp->enqueue(q ,m);
#endif
if (f->flags & DN_IS_RED && red_drops(q, m->m_pkthdr.len)) {
if (!(f->flags & DN_IS_ECN) || !ecn_mark(m))
goto drop;
}
if (f->flags & DN_QSIZE_BYTES) {
if (q->ni.len_bytes > f->qsize)
goto drop;
} else if (q->ni.length >= f->qsize) {
goto drop;
}
mq_append(&q->mq, m);
q->ni.length++;
q->ni.len_bytes += len;
ni->length++;
ni->len_bytes += len;
return (0);
drop:
io_pkt_drop++;
q->ni.drops++;
ni->drops++;
FREE_PKT(m);
return (1);
}
/*
* Fetch packets from the delay line which are due now. If there are
* leftover packets, reinsert the delay line in the heap.
* Runs under scheduler lock.
*/
static void
transmit_event(struct mq *q, struct delay_line *dline, uint64_t now)
{
struct mbuf *m;
struct dn_pkt_tag *pkt = NULL;
dline->oid.subtype = 0; /* not in heap */
while ((m = dline->mq.head) != NULL) {
pkt = dn_tag_get(m);
if (!DN_KEY_LEQ(pkt->output_time, now))
break;
dline->mq.head = m->m_nextpkt;
dline->mq.count--;
mq_append(q, m);
}
if (m != NULL) {
dline->oid.subtype = 1; /* in heap */
heap_insert(&dn_cfg.evheap, pkt->output_time, dline);
}
}
/*
* Convert the additional MAC overheads/delays into an equivalent
* number of bits for the given data rate. The samples are
* in milliseconds so we need to divide by 1000.
*/
static uint64_t
extra_bits(struct mbuf *m, struct dn_schk *s)
{
int index;
uint64_t bits;
struct dn_profile *pf = s->profile;
if (!pf || pf->samples_no == 0)
return 0;
index = random() % pf->samples_no;
bits = div64((uint64_t)pf->samples[index] * s->link.bandwidth, 1000);
if (index >= pf->loss_level) {
struct dn_pkt_tag *dt = dn_tag_get(m);
if (dt)
dt->dn_dir = DIR_DROP;
}
return bits;
}
/*
* Send traffic from a scheduler instance due by 'now'.
* Return a pointer to the head of the queue.
*/
static struct mbuf *
serve_sched(struct mq *q, struct dn_sch_inst *si, uint64_t now)
{
struct mq def_q;
struct dn_schk *s = si->sched;
struct mbuf *m = NULL;
int delay_line_idle = (si->dline.mq.head == NULL);
int done, bw;
if (q == NULL) {
q = &def_q;
q->head = NULL;
}
bw = s->link.bandwidth;
si->kflags &= ~DN_ACTIVE;
if (bw > 0)
si->credit += (now - si->sched_time) * bw;
else
si->credit = 0;
si->sched_time = now;
done = 0;
while (si->credit >= 0 && (m = s->fp->dequeue(si)) != NULL) {
uint64_t len_scaled;
done++;
len_scaled = (bw == 0) ? 0 : hz *
(m->m_pkthdr.len * 8 + extra_bits(m, s));
si->credit -= len_scaled;
/* Move packet in the delay line */
dn_tag_get(m)->output_time = dn_cfg.curr_time + s->link.delay ;
mq_append(&si->dline.mq, m);
}
/*
* If credit >= 0 the instance is idle, mark time.
* Otherwise put back in the heap, and adjust the output
* time of the last inserted packet, m, which was too early.
*/
if (si->credit >= 0) {
si->idle_time = now;
} else {
uint64_t t;
KASSERT (bw > 0, ("bw=0 and credit<0 ?"));
t = div64(bw - 1 - si->credit, bw);
if (m)
dn_tag_get(m)->output_time += t;
si->kflags |= DN_ACTIVE;
heap_insert(&dn_cfg.evheap, now + t, si);
}
if (delay_line_idle && done)
transmit_event(q, &si->dline, now);
return q->head;
}
/*
* The timer handler for dummynet. Time is computed in ticks, but
* but the code is tolerant to the actual rate at which this is called.
* Once complete, the function reschedules itself for the next tick.
*/
void
dummynet_task(void *context, int pending)
{
struct timeval t;
struct mq q = { NULL, NULL }; /* queue to accumulate results */
CURVNET_SET((struct vnet *)context);
DN_BH_WLOCK();
/* Update number of lost(coalesced) ticks. */
tick_lost += pending - 1;
getmicrouptime(&t);
/* Last tick duration (usec). */
tick_last = (t.tv_sec - dn_cfg.prev_t.tv_sec) * 1000000 +
(t.tv_usec - dn_cfg.prev_t.tv_usec);
/* Last tick vs standard tick difference (usec). */
tick_delta = (tick_last * hz - 1000000) / hz;
/* Accumulated tick difference (usec). */
tick_delta_sum += tick_delta;
dn_cfg.prev_t = t;
/*
* Adjust curr_time if the accumulated tick difference is
* greater than the 'standard' tick. Since curr_time should
* be monotonically increasing, we do positive adjustments
* as required, and throttle curr_time in case of negative
* adjustment.
*/
dn_cfg.curr_time++;
if (tick_delta_sum - tick >= 0) {
int diff = tick_delta_sum / tick;
dn_cfg.curr_time += diff;
tick_diff += diff;
tick_delta_sum %= tick;
tick_adjustment++;
} else if (tick_delta_sum + tick <= 0) {
dn_cfg.curr_time--;
tick_diff--;
tick_delta_sum += tick;
tick_adjustment++;
}
/* serve pending events, accumulate in q */
for (;;) {
struct dn_id *p; /* generic parameter to handler */
if (dn_cfg.evheap.elements == 0 ||
DN_KEY_LT(dn_cfg.curr_time, HEAP_TOP(&dn_cfg.evheap)->key))
break;
p = HEAP_TOP(&dn_cfg.evheap)->object;
heap_extract(&dn_cfg.evheap, NULL);
if (p->type == DN_SCH_I) {
serve_sched(&q, (struct dn_sch_inst *)p, dn_cfg.curr_time);
} else { /* extracted a delay line */
transmit_event(&q, (struct delay_line *)p, dn_cfg.curr_time);
}
}
if (dn_cfg.expire && ++dn_cfg.expire_cycle >= dn_cfg.expire) {
dn_cfg.expire_cycle = 0;
dn_drain_scheduler();
dn_drain_queue();
}
dn_reschedule();
DN_BH_WUNLOCK();
if (q.head != NULL)
dummynet_send(q.head);
CURVNET_RESTORE();
}
/*
* forward a chain of packets to the proper destination.
* This runs outside the dummynet lock.
*/
static void
dummynet_send(struct mbuf *m)
{
struct mbuf *n;
NET_EPOCH_ASSERT();
for (; m != NULL; m = n) {
struct ifnet *ifp = NULL; /* gcc 3.4.6 complains */
struct m_tag *tag;
int dst;
n = m->m_nextpkt;
m->m_nextpkt = NULL;
tag = m_tag_first(m);
if (tag == NULL) { /* should not happen */
dst = DIR_DROP;
} else {
struct dn_pkt_tag *pkt = dn_tag_get(m);
/* extract the dummynet info, rename the tag
* to carry reinject info.
*/
if (pkt->dn_dir == (DIR_OUT | PROTO_LAYER2) &&
pkt->ifp == NULL) {
dst = DIR_DROP;
} else {
dst = pkt->dn_dir;
ifp = pkt->ifp;
tag->m_tag_cookie = MTAG_IPFW_RULE;
tag->m_tag_id = 0;
}
}
switch (dst) {
case DIR_OUT:
ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
break ;
case DIR_IN :
netisr_dispatch(NETISR_IP, m);
break;
#ifdef INET6
case DIR_IN | PROTO_IPV6:
netisr_dispatch(NETISR_IPV6, m);
break;
case DIR_OUT | PROTO_IPV6:
ip6_output(m, NULL, NULL, IPV6_FORWARDING, NULL, NULL, NULL);
break;
#endif
case DIR_FWD | PROTO_IFB: /* DN_TO_IFB_FWD: */
if (bridge_dn_p != NULL)
((*bridge_dn_p)(m, ifp));
else
printf("dummynet: if_bridge not loaded\n");
break;
case DIR_IN | PROTO_LAYER2: /* DN_TO_ETH_DEMUX: */
/*
* The Ethernet code assumes the Ethernet header is
* contiguous in the first mbuf header.
* Insure this is true.
*/
if (m->m_len < ETHER_HDR_LEN &&
(m = m_pullup(m, ETHER_HDR_LEN)) == NULL) {
printf("dummynet/ether: pullup failed, "
"dropping packet\n");
break;
}
ether_demux(m->m_pkthdr.rcvif, m);
break;
case DIR_OUT | PROTO_LAYER2: /* DN_TO_ETH_OUT: */
ether_output_frame(ifp, m);
break;
case DIR_DROP:
/* drop the packet after some time */
FREE_PKT(m);
break;
default:
printf("dummynet: bad switch %d!\n", dst);
FREE_PKT(m);
break;
}
}
}
static inline int
tag_mbuf(struct mbuf *m, int dir, struct ip_fw_args *fwa)
{
struct dn_pkt_tag *dt;
struct m_tag *mtag;
mtag = m_tag_get(PACKET_TAG_DUMMYNET,
sizeof(*dt), M_NOWAIT | M_ZERO);
if (mtag == NULL)
return 1; /* Cannot allocate packet header. */
m_tag_prepend(m, mtag); /* Attach to mbuf chain. */
dt = (struct dn_pkt_tag *)(mtag + 1);
dt->rule = fwa->rule;
dt->rule.info &= IPFW_ONEPASS; /* only keep this info */
dt->dn_dir = dir;
dt->ifp = fwa->flags & IPFW_ARGS_OUT ? fwa->ifp : NULL;
/* dt->output tame is updated as we move through */
dt->output_time = dn_cfg.curr_time;
dt->iphdr_off = (dir & PROTO_LAYER2) ? ETHER_HDR_LEN : 0;
return 0;
}
/*
* dummynet hook for packets.
* We use the argument to locate the flowset fs and the sched_set sch
* associated to it. The we apply flow_mask and sched_mask to
* determine the queue and scheduler instances.
*/
int
dummynet_io(struct mbuf **m0, struct ip_fw_args *fwa)
{
struct mbuf *m = *m0;
struct dn_fsk *fs = NULL;
struct dn_sch_inst *si;
struct dn_queue *q = NULL; /* default */
int fs_id, dir;
fs_id = (fwa->rule.info & IPFW_INFO_MASK) +
((fwa->rule.info & IPFW_IS_PIPE) ? 2*DN_MAX_ID : 0);
/* XXXGL: convert args to dir */
if (fwa->flags & IPFW_ARGS_IN)
dir = DIR_IN;
else
dir = DIR_OUT;
if (fwa->flags & IPFW_ARGS_ETHER)
dir |= PROTO_LAYER2;
else if (fwa->flags & IPFW_ARGS_IP6)
dir |= PROTO_IPV6;
DN_BH_WLOCK();
io_pkt++;
/* we could actually tag outside the lock, but who cares... */
if (tag_mbuf(m, dir, fwa))
goto dropit;
if (dn_cfg.busy) {
/* if the upper half is busy doing something expensive,
* lets queue the packet and move forward
*/
mq_append(&dn_cfg.pending, m);
m = *m0 = NULL; /* consumed */
goto done; /* already active, nothing to do */
}
/* XXX locate_flowset could be optimised with a direct ref. */
fs = dn_ht_find(dn_cfg.fshash, fs_id, 0, NULL);
if (fs == NULL)
goto dropit; /* This queue/pipe does not exist! */
if (fs->sched == NULL) /* should not happen */
goto dropit;
/* find scheduler instance, possibly applying sched_mask */
si = ipdn_si_find(fs->sched, &(fwa->f_id));
if (si == NULL)
goto dropit;
/*
* If the scheduler supports multiple queues, find the right one
* (otherwise it will be ignored by enqueue).
*/
if (fs->sched->fp->flags & DN_MULTIQUEUE) {
q = ipdn_q_find(fs, si, &(fwa->f_id));
if (q == NULL)
goto dropit;
}
if (fs->sched->fp->enqueue(si, q, m)) {
/* packet was dropped by enqueue() */
m = *m0 = NULL;
/* dn_enqueue already increases io_pkt_drop */
io_pkt_drop--;
goto dropit;
}
if (si->kflags & DN_ACTIVE) {
m = *m0 = NULL; /* consumed */
goto done; /* already active, nothing to do */
}
/* compute the initial allowance */
if (si->idle_time < dn_cfg.curr_time) {
/* Do this only on the first packet on an idle pipe */
struct dn_link *p = &fs->sched->link;
si->sched_time = dn_cfg.curr_time;
si->credit = dn_cfg.io_fast ? p->bandwidth : 0;
if (p->burst) {
uint64_t burst = (dn_cfg.curr_time - si->idle_time) * p->bandwidth;
if (burst > p->burst)
burst = p->burst;
si->credit += burst;
}
}
/* pass through scheduler and delay line */
m = serve_sched(NULL, si, dn_cfg.curr_time);
/* optimization -- pass it back to ipfw for immediate send */
/* XXX Don't call dummynet_send() if scheduler return the packet
* just enqueued. This avoid a lock order reversal.
*
*/
if (/*dn_cfg.io_fast &&*/ m == *m0 && (dir & PROTO_LAYER2) == 0 ) {
/* fast io, rename the tag * to carry reinject info. */
struct m_tag *tag = m_tag_first(m);
tag->m_tag_cookie = MTAG_IPFW_RULE;
tag->m_tag_id = 0;
io_pkt_fast++;
if (m->m_nextpkt != NULL) {
printf("dummynet: fast io: pkt chain detected!\n");
m->m_nextpkt = NULL;
}
m = NULL;
} else {
*m0 = NULL;
}
done:
DN_BH_WUNLOCK();
if (m)
dummynet_send(m);
return 0;
dropit:
io_pkt_drop++;
DN_BH_WUNLOCK();
if (m)
FREE_PKT(m);
*m0 = NULL;
return (fs && (fs->fs.flags & DN_NOERROR)) ? 0 : ENOBUFS;
}
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