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freebsd-skq/sys/netgraph/ng_pipe.c

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/*
* Copyright (c) 2004-2008 University of Zagreb
* Copyright (c) 2007-2008 FreeBSD Foundation
*
* This software was developed by the University of Zagreb and the
* FreeBSD Foundation under sponsorship by the Stichting NLnet and the
* FreeBSD Foundation.
*
* 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.
*
* $FreeBSD$
*/
/*
* This node permits simple traffic shaping by emulating bandwidth
* and delay, as well as random packet losses.
* The node has two hooks, upper and lower. Traffic flowing from upper to
* lower hook is referenced as downstream, and vice versa. Parameters for
* both directions can be set separately, except for delay.
*/
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/time.h>
#include <sys/vimage.h>
#include <vm/uma.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_pipe.h>
static MALLOC_DEFINE(M_NG_PIPE, "ng_pipe", "ng_pipe");
struct mtx ng_pipe_giant;
/* Packet header struct */
struct ngp_hdr {
TAILQ_ENTRY(ngp_hdr) ngp_link; /* next pkt in queue */
struct timeval when; /* this packet's due time */
struct mbuf *m; /* ptr to the packet data */
};
TAILQ_HEAD(p_head, ngp_hdr);
/* FIFO queue struct */
struct ngp_fifo {
TAILQ_ENTRY(ngp_fifo) fifo_le; /* list of active queues only */
struct p_head packet_head; /* FIFO queue head */
u_int32_t hash; /* flow signature */
struct timeval vtime; /* virtual time, for WFQ */
u_int32_t rr_deficit; /* for DRR */
u_int32_t packets; /* # of packets in this queue */
};
/* Per hook info */
struct hookinfo {
hook_p hook;
int noqueue; /* bypass any processing */
TAILQ_HEAD(, ngp_fifo) fifo_head; /* FIFO queues */
TAILQ_HEAD(, ngp_hdr) qout_head; /* delay queue head */
LIST_ENTRY(hookinfo) active_le; /* active hooks */
struct timeval qin_utime;
struct ng_pipe_hookcfg cfg;
struct ng_pipe_hookrun run;
struct ng_pipe_hookstat stats;
uint64_t *ber_p; /* loss_p(BER,psize) map */
};
/* Per node info */
struct node_priv {
u_int64_t delay;
u_int32_t overhead;
u_int32_t header_offset;
struct hookinfo lower;
struct hookinfo upper;
};
typedef struct node_priv *priv_p;
/* Macro for calculating the virtual time for packet dequeueing in WFQ */
#define FIFO_VTIME_SORT(plen) \
if (hinfo->cfg.wfq && hinfo->cfg.bandwidth) { \
ngp_f->vtime.tv_usec = now->tv_usec + ((uint64_t) (plen) \
+ priv->overhead ) * hinfo->run.fifo_queues * \
8000000 / hinfo->cfg.bandwidth; \
ngp_f->vtime.tv_sec = now->tv_sec + \
ngp_f->vtime.tv_usec / 1000000; \
ngp_f->vtime.tv_usec = ngp_f->vtime.tv_usec % 1000000; \
TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le) \
if (ngp_f1->vtime.tv_sec > ngp_f->vtime.tv_sec || \
(ngp_f1->vtime.tv_sec == ngp_f->vtime.tv_sec && \
ngp_f1->vtime.tv_usec > ngp_f->vtime.tv_usec)) \
break; \
if (ngp_f1 == NULL) \
TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le); \
else \
TAILQ_INSERT_BEFORE(ngp_f1, ngp_f, fifo_le); \
} else \
TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le); \
static void parse_cfg(struct ng_pipe_hookcfg *, struct ng_pipe_hookcfg *,
struct hookinfo *, priv_p);
static void pipe_dequeue(struct hookinfo *, struct timeval *);
static void pipe_scheduler(void *);
static void pipe_poll(void);
static int ngp_modevent(module_t, int, void *);
/* linked list of active "pipe" hooks */
static LIST_HEAD(, hookinfo) active_head;
static int active_gen_id = 0;
/* timeout handle for pipe_scheduler */
static struct callout polling_timer;
/* zone for storing ngp_hdr-s */
static uma_zone_t ngp_zone;
/* Netgraph methods */
static ng_constructor_t ngp_constructor;
static ng_rcvmsg_t ngp_rcvmsg;
static ng_shutdown_t ngp_shutdown;
static ng_newhook_t ngp_newhook;
static ng_rcvdata_t ngp_rcvdata;
static ng_disconnect_t ngp_disconnect;
/* Parse type for struct ng_pipe_hookstat */
static const struct ng_parse_struct_field
ng_pipe_hookstat_type_fields[] = NG_PIPE_HOOKSTAT_INFO;
static const struct ng_parse_type ng_pipe_hookstat_type = {
&ng_parse_struct_type,
&ng_pipe_hookstat_type_fields
};
/* Parse type for struct ng_pipe_stats */
static const struct ng_parse_struct_field ng_pipe_stats_type_fields[] =
NG_PIPE_STATS_INFO(&ng_pipe_hookstat_type);
static const struct ng_parse_type ng_pipe_stats_type = {
&ng_parse_struct_type,
&ng_pipe_stats_type_fields
};
/* Parse type for struct ng_pipe_hookrun */
static const struct ng_parse_struct_field
ng_pipe_hookrun_type_fields[] = NG_PIPE_HOOKRUN_INFO;
static const struct ng_parse_type ng_pipe_hookrun_type = {
&ng_parse_struct_type,
&ng_pipe_hookrun_type_fields
};
/* Parse type for struct ng_pipe_run */
static const struct ng_parse_struct_field
ng_pipe_run_type_fields[] = NG_PIPE_RUN_INFO(&ng_pipe_hookrun_type);
static const struct ng_parse_type ng_pipe_run_type = {
&ng_parse_struct_type,
&ng_pipe_run_type_fields
};
/* Parse type for struct ng_pipe_hookcfg */
static const struct ng_parse_struct_field
ng_pipe_hookcfg_type_fields[] = NG_PIPE_HOOKCFG_INFO;
static const struct ng_parse_type ng_pipe_hookcfg_type = {
&ng_parse_struct_type,
&ng_pipe_hookcfg_type_fields
};
/* Parse type for struct ng_pipe_cfg */
static const struct ng_parse_struct_field
ng_pipe_cfg_type_fields[] = NG_PIPE_CFG_INFO(&ng_pipe_hookcfg_type);
static const struct ng_parse_type ng_pipe_cfg_type = {
&ng_parse_struct_type,
&ng_pipe_cfg_type_fields
};
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ngp_cmds[] = {
{
.cookie = NGM_PIPE_COOKIE,
.cmd = NGM_PIPE_GET_STATS,
.name = "getstats",
.respType = &ng_pipe_stats_type
},
{
.cookie = NGM_PIPE_COOKIE,
.cmd = NGM_PIPE_CLR_STATS,
.name = "clrstats"
},
{
.cookie = NGM_PIPE_COOKIE,
.cmd = NGM_PIPE_GETCLR_STATS,
.name = "getclrstats",
.respType = &ng_pipe_stats_type
},
{
.cookie = NGM_PIPE_COOKIE,
.cmd = NGM_PIPE_GET_RUN,
.name = "getrun",
.respType = &ng_pipe_run_type
},
{
.cookie = NGM_PIPE_COOKIE,
.cmd = NGM_PIPE_GET_CFG,
.name = "getcfg",
.respType = &ng_pipe_cfg_type
},
{
.cookie = NGM_PIPE_COOKIE,
.cmd = NGM_PIPE_SET_CFG,
.name = "setcfg",
.mesgType = &ng_pipe_cfg_type,
},
{ 0 }
};
/* Netgraph type descriptor */
static struct ng_type ng_pipe_typestruct = {
.version = NG_ABI_VERSION,
.name = NG_PIPE_NODE_TYPE,
.mod_event = ngp_modevent,
.constructor = ngp_constructor,
.shutdown = ngp_shutdown,
.rcvmsg = ngp_rcvmsg,
.newhook = ngp_newhook,
.rcvdata = ngp_rcvdata,
.disconnect = ngp_disconnect,
.cmdlist = ngp_cmds
};
NETGRAPH_INIT(pipe, &ng_pipe_typestruct);
/* Node constructor */
static int
ngp_constructor(node_p node)
{
priv_p priv;
priv = malloc(sizeof(*priv), M_NG_PIPE, M_ZERO | M_NOWAIT);
if (priv == NULL)
return (ENOMEM);
NG_NODE_SET_PRIVATE(node, priv);
return (0);
}
/* Add a hook */
static int
ngp_newhook(node_p node, hook_p hook, const char *name)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct hookinfo *hinfo;
if (strcmp(name, NG_PIPE_HOOK_UPPER) == 0) {
bzero(&priv->upper, sizeof(priv->upper));
priv->upper.hook = hook;
NG_HOOK_SET_PRIVATE(hook, &priv->upper);
} else if (strcmp(name, NG_PIPE_HOOK_LOWER) == 0) {
bzero(&priv->lower, sizeof(priv->lower));
priv->lower.hook = hook;
NG_HOOK_SET_PRIVATE(hook, &priv->lower);
} else
return (EINVAL);
/* Load non-zero initial cfg values */
hinfo = NG_HOOK_PRIVATE(hook);
hinfo->cfg.qin_size_limit = 50;
hinfo->cfg.fifo = 1;
hinfo->cfg.droptail = 1;
TAILQ_INIT(&hinfo->fifo_head);
TAILQ_INIT(&hinfo->qout_head);
return (0);
}
/* Receive a control message */
static int
ngp_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_mesg *resp = NULL;
struct ng_mesg *msg;
struct ng_pipe_stats *stats;
struct ng_pipe_run *run;
struct ng_pipe_cfg *cfg;
int error = 0;
mtx_lock(&ng_pipe_giant);
NGI_GET_MSG(item, msg);
switch (msg->header.typecookie) {
case NGM_PIPE_COOKIE:
switch (msg->header.cmd) {
case NGM_PIPE_GET_STATS:
case NGM_PIPE_CLR_STATS:
case NGM_PIPE_GETCLR_STATS:
if (msg->header.cmd != NGM_PIPE_CLR_STATS) {
NG_MKRESPONSE(resp, msg,
sizeof(*stats), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
stats = (struct ng_pipe_stats *)resp->data;
bcopy(&priv->upper.stats, &stats->downstream,
sizeof(stats->downstream));
bcopy(&priv->lower.stats, &stats->upstream,
sizeof(stats->upstream));
}
if (msg->header.cmd != NGM_PIPE_GET_STATS) {
bzero(&priv->upper.stats,
sizeof(priv->upper.stats));
bzero(&priv->lower.stats,
sizeof(priv->lower.stats));
}
break;
case NGM_PIPE_GET_RUN:
NG_MKRESPONSE(resp, msg, sizeof(*run), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
run = (struct ng_pipe_run *)resp->data;
bcopy(&priv->upper.run, &run->downstream,
sizeof(run->downstream));
bcopy(&priv->lower.run, &run->upstream,
sizeof(run->upstream));
break;
case NGM_PIPE_GET_CFG:
NG_MKRESPONSE(resp, msg, sizeof(*cfg), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
cfg = (struct ng_pipe_cfg *)resp->data;
bcopy(&priv->upper.cfg, &cfg->downstream,
sizeof(cfg->downstream));
bcopy(&priv->lower.cfg, &cfg->upstream,
sizeof(cfg->upstream));
cfg->delay = priv->delay;
cfg->overhead = priv->overhead;
cfg->header_offset = priv->header_offset;
if (cfg->upstream.bandwidth ==
cfg->downstream.bandwidth) {
cfg->bandwidth = cfg->upstream.bandwidth;
cfg->upstream.bandwidth = 0;
cfg->downstream.bandwidth = 0;
} else
cfg->bandwidth = 0;
break;
case NGM_PIPE_SET_CFG:
cfg = (struct ng_pipe_cfg *)msg->data;
if (msg->header.arglen != sizeof(*cfg)) {
error = EINVAL;
break;
}
if (cfg->delay == -1)
priv->delay = 0;
else if (cfg->delay > 0 && cfg->delay < 10000000)
priv->delay = cfg->delay;
if (cfg->bandwidth == -1) {
priv->upper.cfg.bandwidth = 0;
priv->lower.cfg.bandwidth = 0;
priv->overhead = 0;
} else if (cfg->bandwidth >= 100 &&
cfg->bandwidth <= 1000000000) {
priv->upper.cfg.bandwidth = cfg->bandwidth;
priv->lower.cfg.bandwidth = cfg->bandwidth;
if (cfg->bandwidth >= 10000000)
priv->overhead = 8+4+12; /* Ethernet */
else
priv->overhead = 10; /* HDLC */
}
if (cfg->overhead == -1)
priv->overhead = 0;
else if (cfg->overhead > 0 && cfg->overhead < 256)
priv->overhead = cfg->overhead;
if (cfg->header_offset == -1)
priv->header_offset = 0;
else if (cfg->header_offset > 0 &&
cfg->header_offset < 64)
priv->header_offset = cfg->header_offset;
parse_cfg(&priv->upper.cfg, &cfg->downstream,
&priv->upper, priv);
parse_cfg(&priv->lower.cfg, &cfg->upstream,
&priv->lower, priv);
break;
default:
error = EINVAL;
break;
}
break;
default:
error = EINVAL;
break;
}
NG_RESPOND_MSG(error, node, item, resp);
NG_FREE_MSG(msg);
mtx_unlock(&ng_pipe_giant);
return (error);
}
static void
parse_cfg(struct ng_pipe_hookcfg *current, struct ng_pipe_hookcfg *new,
struct hookinfo *hinfo, priv_p priv)
{
if (new->ber == -1) {
current->ber = 0;
if (hinfo->ber_p) {
free(hinfo->ber_p, M_NG_PIPE);
hinfo->ber_p = NULL;
}
} else if (new->ber >= 1 && new->ber <= 1000000000000) {
static const uint64_t one = 0x1000000000000; /* = 2^48 */
uint64_t p0, p;
uint32_t fsize, i;
if (hinfo->ber_p == NULL)
hinfo->ber_p = malloc(\
(MAX_FSIZE + MAX_OHSIZE)*sizeof(uint64_t), \
M_NG_PIPE, M_NOWAIT);
current->ber = new->ber;
/*
* For given BER and each frame size N (in bytes) calculate
* the probability P_OK that the frame is clean:
*
* P_OK(BER,N) = (1 - 1/BER)^(N*8)
*
* We use a 64-bit fixed-point format with decimal point
* positioned between bits 47 and 48.
*/
p0 = one - one / new->ber;
p = one;
for (fsize = 0; fsize < MAX_FSIZE + MAX_OHSIZE; fsize++) {
hinfo->ber_p[fsize] = p;
for (i=0; i<8; i++)
p = (p*(p0&0xffff)>>48) + \
(p*((p0>>16)&0xffff)>>32) + \
(p*(p0>>32)>>16);
}
}
if (new->qin_size_limit == -1)
current->qin_size_limit = 0;
else if (new->qin_size_limit >= 5)
current->qin_size_limit = new->qin_size_limit;
if (new->qout_size_limit == -1)
current->qout_size_limit = 0;
else if (new->qout_size_limit >= 5)
current->qout_size_limit = new->qout_size_limit;
if (new->duplicate == -1)
current->duplicate = 0;
else if (new->duplicate > 0 && new->duplicate <= 50)
current->duplicate = new->duplicate;
if (new->fifo) {
current->fifo = 1;
current->wfq = 0;
current->drr = 0;
}
if (new->wfq) {
current->fifo = 0;
current->wfq = 1;
current->drr = 0;
}
if (new->drr) {
current->fifo = 0;
current->wfq = 0;
/* DRR quantum */
if (new->drr >= 32)
current->drr = new->drr;
else
current->drr = 2048; /* default quantum */
}
if (new->droptail) {
current->droptail = 1;
current->drophead = 0;
}
if (new->drophead) {
current->droptail = 0;
current->drophead = 1;
}
if (new->bandwidth == -1) {
current->bandwidth = 0;
current->fifo = 1;
current->wfq = 0;
current->drr = 0;
} else if (new->bandwidth >= 100 && new->bandwidth <= 1000000000)
current->bandwidth = new->bandwidth;
if (current->bandwidth | priv->delay |
current->duplicate | current->ber)
hinfo->noqueue = 0;
else
hinfo->noqueue = 1;
}
/*
* Compute a hash signature for a packet. This function suffers from the
* NIH sindrome, so probably it would be wise to look around what other
* folks have found out to be a good and efficient IP hash function...
*/
static int
ip_hash(struct mbuf *m, int offset)
{
u_int64_t i;
struct ip *ip = (struct ip *)(mtod(m, u_char *) + offset);
if (m->m_len < sizeof(struct ip) + offset ||
ip->ip_v != 4 || ip->ip_hl << 2 != sizeof(struct ip))
return 0;
i = ((u_int64_t) ip->ip_src.s_addr ^
((u_int64_t) ip->ip_src.s_addr << 13) ^
((u_int64_t) ip->ip_dst.s_addr << 7) ^
((u_int64_t) ip->ip_dst.s_addr << 19));
return (i ^ (i >> 32));
}
/*
* Receive data on a hook - both in upstream and downstream direction.
* We put the frame on the inbound queue, and try to initiate dequeuing
* sequence immediately. If inbound queue is full, discard one frame
* depending on dropping policy (from the head or from the tail of the
* queue).
*/
static int
ngp_rcvdata(hook_p hook, item_p item)
{
struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
struct timeval uuptime;
struct timeval *now = &uuptime;
struct ngp_fifo *ngp_f = NULL, *ngp_f1;
struct ngp_hdr *ngp_h = NULL;
struct mbuf *m;
int hash;
int error = 0;
if (hinfo->noqueue) {
struct hookinfo *dest;
if (hinfo == &priv->lower)
dest = &priv->upper;
else
dest = &priv->lower;
NG_FWD_ITEM_HOOK(error, item, dest->hook);
return error;
}
mtx_lock(&ng_pipe_giant);
microuptime(now);
/*
* Attach us to the list of active ng_pipes if this was an empty
* one before, and also update the queue service deadline time.
*/
if (hinfo->run.qin_frames == 0) {
struct timeval *when = &hinfo->qin_utime;
if (when->tv_sec < now->tv_sec || (when->tv_sec == now->tv_sec
&& when->tv_usec < now->tv_usec)) {
when->tv_sec = now->tv_sec;
when->tv_usec = now->tv_usec;
}
if (hinfo->run.qout_frames == 0)
LIST_INSERT_HEAD(&active_head, hinfo, active_le);
}
/* Populate the packet header */
ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
KASSERT((ngp_h != NULL), ("ngp_h zalloc failed (1)"));
NGI_GET_M(item, m);
KASSERT(m != NULL, ("NGI_GET_M failed"));
ngp_h->m = m;
NG_FREE_ITEM(item);
if (hinfo->cfg.fifo)
hash = 0; /* all packets go into a single FIFO queue */
else
hash = ip_hash(m, priv->header_offset);
/* Find the appropriate FIFO queue for the packet and enqueue it*/
TAILQ_FOREACH(ngp_f, &hinfo->fifo_head, fifo_le)
if (hash == ngp_f->hash)
break;
if (ngp_f == NULL) {
ngp_f = uma_zalloc(ngp_zone, M_NOWAIT);
KASSERT(ngp_h != NULL, ("ngp_h zalloc failed (2)"));
TAILQ_INIT(&ngp_f->packet_head);
ngp_f->hash = hash;
ngp_f->packets = 1;
ngp_f->rr_deficit = hinfo->cfg.drr; /* DRR quantum */
hinfo->run.fifo_queues++;
TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
FIFO_VTIME_SORT(m->m_pkthdr.len);
} else {
TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
ngp_f->packets++;
}
hinfo->run.qin_frames++;
hinfo->run.qin_octets += m->m_pkthdr.len;
/* Discard a frame if inbound queue limit has been reached */
if (hinfo->run.qin_frames > hinfo->cfg.qin_size_limit) {
struct mbuf *m1;
int longest = 0;
/* Find the longest queue */
TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)
if (ngp_f1->packets > longest) {
longest = ngp_f1->packets;
ngp_f = ngp_f1;
}
/* Drop a frame from the queue head/tail, depending on cfg */
if (hinfo->cfg.drophead)
ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
else
ngp_h = TAILQ_LAST(&ngp_f->packet_head, p_head);
TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
m1 = ngp_h->m;
uma_zfree(ngp_zone, ngp_h);
hinfo->run.qin_octets -= m1->m_pkthdr.len;
hinfo->stats.in_disc_octets += m1->m_pkthdr.len;
m_freem(m1);
if (--(ngp_f->packets) == 0) {
TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
uma_zfree(ngp_zone, ngp_f);
hinfo->run.fifo_queues--;
}
hinfo->run.qin_frames--;
hinfo->stats.in_disc_frames++;
} else if (hinfo->run.qin_frames > hinfo->cfg.qin_size_limit) {
struct mbuf *m1;
int longest = 0;
/* Find the longest queue */
TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)
if (ngp_f1->packets > longest) {
longest = ngp_f1->packets;
ngp_f = ngp_f1;
}
/* Drop a frame from the queue head/tail, depending on cfg */
if (hinfo->cfg.drophead)
ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
else
ngp_h = TAILQ_LAST(&ngp_f->packet_head, p_head);
TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
m1 = ngp_h->m;
uma_zfree(ngp_zone, ngp_h);
hinfo->run.qin_octets -= m1->m_pkthdr.len;
hinfo->stats.in_disc_octets += m1->m_pkthdr.len;
m_freem(m1);
if (--(ngp_f->packets) == 0) {
TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
uma_zfree(ngp_zone, ngp_f);
hinfo->run.fifo_queues--;
}
hinfo->run.qin_frames--;
hinfo->stats.in_disc_frames++;
}
/*
* Try to start the dequeuing process immediately. We must
* hold the ng_pipe_giant lock here and pipe_dequeue() will
* release it
*/
pipe_dequeue(hinfo, now);
return (0);
}
/*
* Dequeueing sequence - we basically do the following:
* 1) Try to extract the frame from the inbound (bandwidth) queue;
* 2) In accordance to BER specified, discard the frame randomly;
* 3) If the frame survives BER, prepend it with delay info and move it
* to outbound (delay) queue;
* 4) Loop to 2) until bandwidth quota for this timeslice is reached, or
* inbound queue is flushed completely;
* 5) Extract the first frame from the outbound queue, if it's time has
* come. Queue the frame for transmission on the outbound hook;
* 6) Loop to 5) until outbound queue is flushed completely, or the next
* frame in the queue is not scheduled to be dequeued yet;
* 7) Transimit all frames queued in 5)
*
* Note: the caller must hold the ng_pipe_giant lock; this function
* returns with the lock released.
*/
static void
pipe_dequeue(struct hookinfo *hinfo, struct timeval *now) {
static uint64_t rand, oldrand;
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hinfo->hook));
struct hookinfo *dest;
struct ngp_fifo *ngp_f, *ngp_f1;
struct ngp_hdr *ngp_h;
struct timeval *when;
struct mbuf *q_head = NULL;
struct mbuf *q_tail = NULL;
struct mbuf *m;
int error = 0;
/* Which one is the destination hook? */
if (hinfo == &priv->lower)
dest = &priv->upper;
else
dest = &priv->lower;
/* Bandwidth queue processing */
while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
when = &hinfo->qin_utime;
if (when->tv_sec > now->tv_sec || (when->tv_sec == now->tv_sec
&& when->tv_usec > now->tv_usec))
break;
ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
m = ngp_h->m;
/* Deficit Round Robin (DRR) processing */
if (hinfo->cfg.drr) {
if (ngp_f->rr_deficit >= m->m_pkthdr.len) {
ngp_f->rr_deficit -= m->m_pkthdr.len;
} else {
ngp_f->rr_deficit += hinfo->cfg.drr;
TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
TAILQ_INSERT_TAIL(&hinfo->fifo_head,
ngp_f, fifo_le);
continue;
}
}
/*
* Either create a duplicate and pass it on, or dequeue
* the original packet...
*/
if (hinfo->cfg.duplicate &&
random() % 100 <= hinfo->cfg.duplicate) {
ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
KASSERT(ngp_h != NULL, ("ngp_h zalloc failed (3)"));
ngp_h->m = m_dup(m, M_NOWAIT);
KASSERT(ngp_h->m != NULL, ("m_dup failed"));
} else {
TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
hinfo->run.qin_frames--;
hinfo->run.qin_octets -= m->m_pkthdr.len;
ngp_f->packets--;
}
/* Calculate the serialization delay */
if (hinfo->cfg.bandwidth) {
hinfo->qin_utime.tv_usec += ((uint64_t) m->m_pkthdr.len
+ priv->overhead ) *
8000000 / hinfo->cfg.bandwidth;
hinfo->qin_utime.tv_sec +=
hinfo->qin_utime.tv_usec / 1000000;
hinfo->qin_utime.tv_usec =
hinfo->qin_utime.tv_usec % 1000000;
}
when = &ngp_h->when;
when->tv_sec = hinfo->qin_utime.tv_sec;
when->tv_usec = hinfo->qin_utime.tv_usec;
/* Sort / rearrange inbound queues */
if (ngp_f->packets) {
if (hinfo->cfg.wfq) {
TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
FIFO_VTIME_SORT(TAILQ_FIRST(
&ngp_f->packet_head)->m->m_pkthdr.len)
}
} else {
TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
uma_zfree(ngp_zone, ngp_f);
hinfo->run.fifo_queues--;
}
/* Randomly discard the frame, according to BER setting */
if (hinfo->cfg.ber &&
((oldrand = rand) ^ (rand = random())<<17) >=
hinfo->ber_p[priv->overhead + m->m_pkthdr.len] ) {
hinfo->stats.out_disc_frames++;
hinfo->stats.out_disc_octets += m->m_pkthdr.len;
uma_zfree(ngp_zone, ngp_h);
m_freem(m);
continue;
}
/* Discard frame if outbound queue size limit exceeded */
if (hinfo->cfg.qout_size_limit &&
hinfo->run.qout_frames>=hinfo->cfg.qout_size_limit) {
hinfo->stats.out_disc_frames++;
hinfo->stats.out_disc_octets += m->m_pkthdr.len;
uma_zfree(ngp_zone, ngp_h);
m_freem(m);
continue;
}
/* Calculate the propagation delay */
when->tv_usec += priv->delay;
when->tv_sec += when->tv_usec / 1000000;
when->tv_usec = when->tv_usec % 1000000;
/* Put the frame into the delay queue */
TAILQ_INSERT_TAIL(&hinfo->qout_head, ngp_h, ngp_link);
hinfo->run.qout_frames++;
hinfo->run.qout_octets += m->m_pkthdr.len;
}
/* Delay queue processing */
while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
struct mbuf *m = ngp_h->m;
when = &ngp_h->when;
if (when->tv_sec > now->tv_sec ||
(when->tv_sec == now->tv_sec &&
when->tv_usec > now->tv_usec))
break;
/* Update outbound queue stats */
hinfo->stats.fwd_frames++;
hinfo->stats.fwd_octets += m->m_pkthdr.len;
hinfo->run.qout_frames--;
hinfo->run.qout_octets -= m->m_pkthdr.len;
/* Dequeue the packet from qout */
TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
uma_zfree(ngp_zone, ngp_h);
/* Enqueue locally for sending downstream */
if (q_head == NULL)
q_head = m;
if (q_tail)
q_tail->m_nextpkt = m;
q_tail = m;
m->m_nextpkt = NULL;
}
/* If both queues are empty detach us from the list of active queues */
if (hinfo->run.qin_frames + hinfo->run.qout_frames == 0) {
LIST_REMOVE(hinfo, active_le);
active_gen_id++;
}
mtx_unlock(&ng_pipe_giant);
while ((m = q_head) != NULL) {
q_head = m->m_nextpkt;
m->m_nextpkt = NULL;
NG_SEND_DATA(error, dest->hook, m, meta);
}
}
/*
* This routine is called on every clock tick. We poll all nodes/hooks
* for queued frames by calling pipe_dequeue().
*/
static void
pipe_scheduler(void *arg)
{
pipe_poll();
/* Reschedule */
callout_reset(&polling_timer, 1, &pipe_scheduler, NULL);
}
/*
* Traverse the list of all active hooks and attempt to dequeue
* some packets. Hooks with empty queues are not traversed since
* they are not linked into this list.
*/
static void
pipe_poll(void)
{
struct hookinfo *hinfo;
struct timeval now;
int old_gen_id = active_gen_id;
mtx_lock(&ng_pipe_giant);
microuptime(&now);
LIST_FOREACH(hinfo, &active_head, active_le) {
CURVNET_SET(NG_HOOK_NODE(hinfo->hook)->nd_vnet);
pipe_dequeue(hinfo, &now);
CURVNET_RESTORE();
mtx_lock(&ng_pipe_giant);
if (old_gen_id != active_gen_id) {
/* the list was updated; restart traversing */
hinfo = LIST_FIRST(&active_head);
if (hinfo == NULL)
break;
old_gen_id = active_gen_id;
continue;
}
}
mtx_unlock(&ng_pipe_giant);
}
/*
* Shutdown processing
*
* This is tricky. If we have both a lower and upper hook, then we
* probably want to extricate ourselves and leave the two peers
* still linked to each other. Otherwise we should just shut down as
* a normal node would.
*/
static int
ngp_shutdown(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (priv->lower.hook && priv->upper.hook)
ng_bypass(priv->lower.hook, priv->upper.hook);
else {
if (priv->upper.hook != NULL)
ng_rmhook_self(priv->upper.hook);
if (priv->lower.hook != NULL)
ng_rmhook_self(priv->lower.hook);
}
NG_NODE_UNREF(node);
free(priv, M_NG_PIPE);
return (0);
}
/*
* Hook disconnection
*/
static int
ngp_disconnect(hook_p hook)
{
struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
struct ngp_fifo *ngp_f;
struct ngp_hdr *ngp_h;
int removed = 0;
mtx_lock(&ng_pipe_giant);
KASSERT(hinfo != NULL, ("%s: null info", __FUNCTION__));
hinfo->hook = NULL;
/* Flush all fifo queues associated with the hook */
while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
while ((ngp_h = TAILQ_FIRST(&ngp_f->packet_head))) {
TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
m_freem(ngp_h->m);
uma_zfree(ngp_zone, ngp_h);
removed++;
}
TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
uma_zfree(ngp_zone, ngp_f);
}
/* Flush the delay queue */
while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
m_freem(ngp_h->m);
uma_zfree(ngp_zone, ngp_h);
removed++;
}
/*
* Both queues should be empty by now, so detach us from
* the list of active queues
*/
if (removed) {
LIST_REMOVE(hinfo, active_le);
active_gen_id++;
}
if (hinfo->run.qin_frames + hinfo->run.qout_frames != removed)
printf("Mismatch: queued=%d but removed=%d !?!",
hinfo->run.qin_frames + hinfo->run.qout_frames, removed);
/* Release the packet loss probability table (BER) */
if (hinfo->ber_p)
free(hinfo->ber_p, M_NG_PIPE);
mtx_unlock(&ng_pipe_giant);
return (0);
}
static int
ngp_modevent(module_t mod, int type, void *unused)
{
int error = 0;
switch (type) {
case MOD_LOAD:
ngp_zone = uma_zcreate("ng_pipe", max(sizeof(struct ngp_hdr),
sizeof (struct ngp_fifo)), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
if (ngp_zone == NULL)
panic("ng_pipe: couldn't allocate descriptor zone");
mtx_init(&ng_pipe_giant, "ng_pipe_giant", NULL, MTX_DEF);
LIST_INIT(&active_head);
callout_init(&polling_timer, CALLOUT_MPSAFE);
callout_reset(&polling_timer, 1, &pipe_scheduler, NULL);
break;
case MOD_UNLOAD:
callout_drain(&polling_timer);
uma_zdestroy(ngp_zone);
mtx_destroy(&ng_pipe_giant);
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
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