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freebsd-skq/sys/netgraph/ng_ppp.c
Gleb Smirnoff 674d86bf91 Node constructor methods are supposed to be called in syscall 
context always. Convert nodes to consistently use M_WAITOK flag
for memory allocation.

Reviewed by:	julian
2011-04-18 09:12:27 +00:00

2619 lines
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/*-
* Copyright (c) 1996-2000 Whistle Communications, Inc.
* All rights reserved.
*
* Subject to the following obligations and disclaimer of warranty, use and
* redistribution of this software, in source or object code forms, with or
* without modifications are expressly permitted by Whistle Communications;
* provided, however, that:
* 1. Any and all reproductions of the source or object code must include the
* copyright notice above and the following disclaimer of warranties; and
* 2. No rights are granted, in any manner or form, to use Whistle
* Communications, Inc. trademarks, including the mark "WHISTLE
* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
* such appears in the above copyright notice or in the software.
*
* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER 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 WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* Copyright (c) 2007 Alexander Motin <mav@alkar.net>
* 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 unmodified, 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.
*
* Authors: Archie Cobbs <archie@freebsd.org>, Alexander Motin <mav@alkar.net>
*
* $FreeBSD$
* $Whistle: ng_ppp.c,v 1.24 1999/11/01 09:24:52 julian Exp $
*/
/*
* PPP node type data-flow.
*
* hook xmit layer recv hook
* ------------------------------------
* inet -> -> inet
* ipv6 -> -> ipv6
* ipx -> proto -> ipx
* atalk -> -> atalk
* bypass -> -> bypass
* -hcomp_xmit()----------proto_recv()-
* vjc_ip <- <- vjc_ip
* vjc_comp -> header compression -> vjc_comp
* vjc_uncomp -> -> vjc_uncomp
* vjc_vjip ->
* -comp_xmit()-----------hcomp_recv()-
* compress <- compression <- decompress
* compress -> -> decompress
* -crypt_xmit()-----------comp_recv()-
* encrypt <- encryption <- decrypt
* encrypt -> -> decrypt
* -ml_xmit()-------------crypt_recv()-
* multilink
* -link_xmit()--------------ml_recv()-
* linkX <- link <- linkX
*
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/time.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/endian.h>
#include <sys/errno.h>
#include <sys/ctype.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_ppp.h>
#include <netgraph/ng_vjc.h>
#ifdef NG_SEPARATE_MALLOC
MALLOC_DEFINE(M_NETGRAPH_PPP, "netgraph_ppp", "netgraph ppp node");
#else
#define M_NETGRAPH_PPP M_NETGRAPH
#endif
#define PROT_VALID(p) (((p) & 0x0101) == 0x0001)
#define PROT_COMPRESSABLE(p) (((p) & 0xff00) == 0x0000)
/* Some PPP protocol numbers we're interested in */
#define PROT_ATALK 0x0029
#define PROT_COMPD 0x00fd
#define PROT_CRYPTD 0x0053
#define PROT_IP 0x0021
#define PROT_IPV6 0x0057
#define PROT_IPX 0x002b
#define PROT_LCP 0xc021
#define PROT_MP 0x003d
#define PROT_VJCOMP 0x002d
#define PROT_VJUNCOMP 0x002f
/* Multilink PPP definitions */
#define MP_INITIAL_SEQ 0 /* per RFC 1990 */
#define MP_MIN_LINK_MRU 32
#define MP_SHORT_SEQ_MASK 0x00000fff /* short seq # mask */
#define MP_SHORT_SEQ_HIBIT 0x00000800 /* short seq # high bit */
#define MP_SHORT_FIRST_FLAG 0x00008000 /* first fragment in frame */
#define MP_SHORT_LAST_FLAG 0x00004000 /* last fragment in frame */
#define MP_LONG_SEQ_MASK 0x00ffffff /* long seq # mask */
#define MP_LONG_SEQ_HIBIT 0x00800000 /* long seq # high bit */
#define MP_LONG_FIRST_FLAG 0x80000000 /* first fragment in frame */
#define MP_LONG_LAST_FLAG 0x40000000 /* last fragment in frame */
#define MP_NOSEQ 0x7fffffff /* impossible sequence number */
/* Sign extension of MP sequence numbers */
#define MP_SHORT_EXTEND(s) (((s) & MP_SHORT_SEQ_HIBIT) ? \
((s) | ~MP_SHORT_SEQ_MASK) \
: ((s) & MP_SHORT_SEQ_MASK))
#define MP_LONG_EXTEND(s) (((s) & MP_LONG_SEQ_HIBIT) ? \
((s) | ~MP_LONG_SEQ_MASK) \
: ((s) & MP_LONG_SEQ_MASK))
/* Comparision of MP sequence numbers. Note: all sequence numbers
except priv->xseq are stored with the sign bit extended. */
#define MP_SHORT_SEQ_DIFF(x,y) MP_SHORT_EXTEND((x) - (y))
#define MP_LONG_SEQ_DIFF(x,y) MP_LONG_EXTEND((x) - (y))
#define MP_RECV_SEQ_DIFF(priv,x,y) \
((priv)->conf.recvShortSeq ? \
MP_SHORT_SEQ_DIFF((x), (y)) : \
MP_LONG_SEQ_DIFF((x), (y)))
/* Increment receive sequence number */
#define MP_NEXT_RECV_SEQ(priv,seq) \
((priv)->conf.recvShortSeq ? \
MP_SHORT_EXTEND((seq) + 1) : \
MP_LONG_EXTEND((seq) + 1))
/* Don't fragment transmitted packets to parts smaller than this */
#define MP_MIN_FRAG_LEN 32
/* Maximum fragment reasssembly queue length */
#define MP_MAX_QUEUE_LEN 128
/* Fragment queue scanner period */
#define MP_FRAGTIMER_INTERVAL (hz/2)
/* Average link overhead. XXX: Should be given by user-level */
#define MP_AVERAGE_LINK_OVERHEAD 16
/* Keep this equal to ng_ppp_hook_names lower! */
#define HOOK_INDEX_MAX 13
/* We store incoming fragments this way */
struct ng_ppp_frag {
int seq; /* fragment seq# */
uint8_t first; /* First in packet? */
uint8_t last; /* Last in packet? */
struct timeval timestamp; /* time of reception */
struct mbuf *data; /* Fragment data */
TAILQ_ENTRY(ng_ppp_frag) f_qent; /* Fragment queue */
};
/* Per-link private information */
struct ng_ppp_link {
struct ng_ppp_link_conf conf; /* link configuration */
struct ng_ppp_link_stat64 stats; /* link stats */
hook_p hook; /* connection to link data */
int32_t seq; /* highest rec'd seq# - MSEQ */
uint32_t latency; /* calculated link latency */
struct timeval lastWrite; /* time of last write for MP */
int bytesInQueue; /* bytes in the output queue for MP */
};
/* Total per-node private information */
struct ng_ppp_private {
struct ng_ppp_bund_conf conf; /* bundle config */
struct ng_ppp_link_stat64 bundleStats; /* bundle stats */
struct ng_ppp_link links[NG_PPP_MAX_LINKS];/* per-link info */
int32_t xseq; /* next out MP seq # */
int32_t mseq; /* min links[i].seq */
uint16_t activeLinks[NG_PPP_MAX_LINKS]; /* indicies */
uint16_t numActiveLinks; /* how many links up */
uint16_t lastLink; /* for round robin */
uint8_t vjCompHooked; /* VJ comp hooked up? */
uint8_t allLinksEqual; /* all xmit the same? */
hook_p hooks[HOOK_INDEX_MAX]; /* non-link hooks */
struct ng_ppp_frag fragsmem[MP_MAX_QUEUE_LEN]; /* fragments storage */
TAILQ_HEAD(ng_ppp_fraglist, ng_ppp_frag) /* fragment queue */
frags;
TAILQ_HEAD(ng_ppp_fragfreelist, ng_ppp_frag) /* free fragment queue */
fragsfree;
struct callout fragTimer; /* fraq queue check */
struct mtx rmtx; /* recv mutex */
struct mtx xmtx; /* xmit mutex */
};
typedef struct ng_ppp_private *priv_p;
/* Netgraph node methods */
static ng_constructor_t ng_ppp_constructor;
static ng_rcvmsg_t ng_ppp_rcvmsg;
static ng_shutdown_t ng_ppp_shutdown;
static ng_newhook_t ng_ppp_newhook;
static ng_rcvdata_t ng_ppp_rcvdata;
static ng_disconnect_t ng_ppp_disconnect;
static ng_rcvdata_t ng_ppp_rcvdata_inet;
static ng_rcvdata_t ng_ppp_rcvdata_ipv6;
static ng_rcvdata_t ng_ppp_rcvdata_ipx;
static ng_rcvdata_t ng_ppp_rcvdata_atalk;
static ng_rcvdata_t ng_ppp_rcvdata_bypass;
static ng_rcvdata_t ng_ppp_rcvdata_vjc_ip;
static ng_rcvdata_t ng_ppp_rcvdata_vjc_comp;
static ng_rcvdata_t ng_ppp_rcvdata_vjc_uncomp;
static ng_rcvdata_t ng_ppp_rcvdata_vjc_vjip;
static ng_rcvdata_t ng_ppp_rcvdata_compress;
static ng_rcvdata_t ng_ppp_rcvdata_decompress;
static ng_rcvdata_t ng_ppp_rcvdata_encrypt;
static ng_rcvdata_t ng_ppp_rcvdata_decrypt;
/* We use integer indicies to refer to the non-link hooks. */
static const struct {
char *const name;
ng_rcvdata_t *fn;
} ng_ppp_hook_names[] = {
#define HOOK_INDEX_ATALK 0
{ NG_PPP_HOOK_ATALK, ng_ppp_rcvdata_atalk },
#define HOOK_INDEX_BYPASS 1
{ NG_PPP_HOOK_BYPASS, ng_ppp_rcvdata_bypass },
#define HOOK_INDEX_COMPRESS 2
{ NG_PPP_HOOK_COMPRESS, ng_ppp_rcvdata_compress },
#define HOOK_INDEX_ENCRYPT 3
{ NG_PPP_HOOK_ENCRYPT, ng_ppp_rcvdata_encrypt },
#define HOOK_INDEX_DECOMPRESS 4
{ NG_PPP_HOOK_DECOMPRESS, ng_ppp_rcvdata_decompress },
#define HOOK_INDEX_DECRYPT 5
{ NG_PPP_HOOK_DECRYPT, ng_ppp_rcvdata_decrypt },
#define HOOK_INDEX_INET 6
{ NG_PPP_HOOK_INET, ng_ppp_rcvdata_inet },
#define HOOK_INDEX_IPX 7
{ NG_PPP_HOOK_IPX, ng_ppp_rcvdata_ipx },
#define HOOK_INDEX_VJC_COMP 8
{ NG_PPP_HOOK_VJC_COMP, ng_ppp_rcvdata_vjc_comp },
#define HOOK_INDEX_VJC_IP 9
{ NG_PPP_HOOK_VJC_IP, ng_ppp_rcvdata_vjc_ip },
#define HOOK_INDEX_VJC_UNCOMP 10
{ NG_PPP_HOOK_VJC_UNCOMP, ng_ppp_rcvdata_vjc_uncomp },
#define HOOK_INDEX_VJC_VJIP 11
{ NG_PPP_HOOK_VJC_VJIP, ng_ppp_rcvdata_vjc_vjip },
#define HOOK_INDEX_IPV6 12
{ NG_PPP_HOOK_IPV6, ng_ppp_rcvdata_ipv6 },
{ NULL, NULL }
};
/* Helper functions */
static int ng_ppp_proto_recv(node_p node, item_p item, uint16_t proto,
uint16_t linkNum);
static int ng_ppp_hcomp_xmit(node_p node, item_p item, uint16_t proto);
static int ng_ppp_hcomp_recv(node_p node, item_p item, uint16_t proto,
uint16_t linkNum);
static int ng_ppp_comp_xmit(node_p node, item_p item, uint16_t proto);
static int ng_ppp_comp_recv(node_p node, item_p item, uint16_t proto,
uint16_t linkNum);
static int ng_ppp_crypt_xmit(node_p node, item_p item, uint16_t proto);
static int ng_ppp_crypt_recv(node_p node, item_p item, uint16_t proto,
uint16_t linkNum);
static int ng_ppp_mp_xmit(node_p node, item_p item, uint16_t proto);
static int ng_ppp_mp_recv(node_p node, item_p item, uint16_t proto,
uint16_t linkNum);
static int ng_ppp_link_xmit(node_p node, item_p item, uint16_t proto,
uint16_t linkNum, int plen);
static int ng_ppp_bypass(node_p node, item_p item, uint16_t proto,
uint16_t linkNum);
static void ng_ppp_bump_mseq(node_p node, int32_t new_mseq);
static int ng_ppp_frag_drop(node_p node);
static int ng_ppp_check_packet(node_p node);
static void ng_ppp_get_packet(node_p node, struct mbuf **mp);
static int ng_ppp_frag_process(node_p node, item_p oitem);
static int ng_ppp_frag_trim(node_p node);
static void ng_ppp_frag_timeout(node_p node, hook_p hook, void *arg1,
int arg2);
static void ng_ppp_frag_checkstale(node_p node);
static void ng_ppp_frag_reset(node_p node);
static void ng_ppp_mp_strategy(node_p node, int len, int *distrib);
static int ng_ppp_intcmp(void *latency, const void *v1, const void *v2);
static struct mbuf *ng_ppp_addproto(struct mbuf *m, uint16_t proto, int compOK);
static struct mbuf *ng_ppp_cutproto(struct mbuf *m, uint16_t *proto);
static struct mbuf *ng_ppp_prepend(struct mbuf *m, const void *buf, int len);
static int ng_ppp_config_valid(node_p node,
const struct ng_ppp_node_conf *newConf);
static void ng_ppp_update(node_p node, int newConf);
static void ng_ppp_start_frag_timer(node_p node);
static void ng_ppp_stop_frag_timer(node_p node);
/* Parse type for struct ng_ppp_mp_state_type */
static const struct ng_parse_fixedarray_info ng_ppp_rseq_array_info = {
&ng_parse_hint32_type,
NG_PPP_MAX_LINKS
};
static const struct ng_parse_type ng_ppp_rseq_array_type = {
&ng_parse_fixedarray_type,
&ng_ppp_rseq_array_info,
};
static const struct ng_parse_struct_field ng_ppp_mp_state_type_fields[]
= NG_PPP_MP_STATE_TYPE_INFO(&ng_ppp_rseq_array_type);
static const struct ng_parse_type ng_ppp_mp_state_type = {
&ng_parse_struct_type,
&ng_ppp_mp_state_type_fields
};
/* Parse type for struct ng_ppp_link_conf */
static const struct ng_parse_struct_field ng_ppp_link_type_fields[]
= NG_PPP_LINK_TYPE_INFO;
static const struct ng_parse_type ng_ppp_link_type = {
&ng_parse_struct_type,
&ng_ppp_link_type_fields
};
/* Parse type for struct ng_ppp_bund_conf */
static const struct ng_parse_struct_field ng_ppp_bund_type_fields[]
= NG_PPP_BUND_TYPE_INFO;
static const struct ng_parse_type ng_ppp_bund_type = {
&ng_parse_struct_type,
&ng_ppp_bund_type_fields
};
/* Parse type for struct ng_ppp_node_conf */
static const struct ng_parse_fixedarray_info ng_ppp_array_info = {
&ng_ppp_link_type,
NG_PPP_MAX_LINKS
};
static const struct ng_parse_type ng_ppp_link_array_type = {
&ng_parse_fixedarray_type,
&ng_ppp_array_info,
};
static const struct ng_parse_struct_field ng_ppp_conf_type_fields[]
= NG_PPP_CONFIG_TYPE_INFO(&ng_ppp_bund_type, &ng_ppp_link_array_type);
static const struct ng_parse_type ng_ppp_conf_type = {
&ng_parse_struct_type,
&ng_ppp_conf_type_fields
};
/* Parse type for struct ng_ppp_link_stat */
static const struct ng_parse_struct_field ng_ppp_stats_type_fields[]
= NG_PPP_STATS_TYPE_INFO;
static const struct ng_parse_type ng_ppp_stats_type = {
&ng_parse_struct_type,
&ng_ppp_stats_type_fields
};
/* Parse type for struct ng_ppp_link_stat64 */
static const struct ng_parse_struct_field ng_ppp_stats64_type_fields[]
= NG_PPP_STATS64_TYPE_INFO;
static const struct ng_parse_type ng_ppp_stats64_type = {
&ng_parse_struct_type,
&ng_ppp_stats64_type_fields
};
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_ppp_cmds[] = {
{
NGM_PPP_COOKIE,
NGM_PPP_SET_CONFIG,
"setconfig",
&ng_ppp_conf_type,
NULL
},
{
NGM_PPP_COOKIE,
NGM_PPP_GET_CONFIG,
"getconfig",
NULL,
&ng_ppp_conf_type
},
{
NGM_PPP_COOKIE,
NGM_PPP_GET_MP_STATE,
"getmpstate",
NULL,
&ng_ppp_mp_state_type
},
{
NGM_PPP_COOKIE,
NGM_PPP_GET_LINK_STATS,
"getstats",
&ng_parse_int16_type,
&ng_ppp_stats_type
},
{
NGM_PPP_COOKIE,
NGM_PPP_CLR_LINK_STATS,
"clrstats",
&ng_parse_int16_type,
NULL
},
{
NGM_PPP_COOKIE,
NGM_PPP_GETCLR_LINK_STATS,
"getclrstats",
&ng_parse_int16_type,
&ng_ppp_stats_type
},
{
NGM_PPP_COOKIE,
NGM_PPP_GET_LINK_STATS64,
"getstats64",
&ng_parse_int16_type,
&ng_ppp_stats64_type
},
{
NGM_PPP_COOKIE,
NGM_PPP_GETCLR_LINK_STATS64,
"getclrstats64",
&ng_parse_int16_type,
&ng_ppp_stats64_type
},
{ 0 }
};
/* Node type descriptor */
static struct ng_type ng_ppp_typestruct = {
.version = NG_ABI_VERSION,
.name = NG_PPP_NODE_TYPE,
.constructor = ng_ppp_constructor,
.rcvmsg = ng_ppp_rcvmsg,
.shutdown = ng_ppp_shutdown,
.newhook = ng_ppp_newhook,
.rcvdata = ng_ppp_rcvdata,
.disconnect = ng_ppp_disconnect,
.cmdlist = ng_ppp_cmds,
};
NETGRAPH_INIT(ppp, &ng_ppp_typestruct);
/* Address and control field header */
static const uint8_t ng_ppp_acf[2] = { 0xff, 0x03 };
/* Maximum time we'll let a complete incoming packet sit in the queue */
static const struct timeval ng_ppp_max_staleness = { 2, 0 }; /* 2 seconds */
#define ERROUT(x) do { error = (x); goto done; } while (0)
/************************************************************************
NETGRAPH NODE STUFF
************************************************************************/
/*
* Node type constructor
*/
static int
ng_ppp_constructor(node_p node)
{
priv_p priv;
int i;
/* Allocate private structure */
priv = malloc(sizeof(*priv), M_NETGRAPH_PPP, M_WAITOK | M_ZERO);
NG_NODE_SET_PRIVATE(node, priv);
/* Initialize state */
TAILQ_INIT(&priv->frags);
TAILQ_INIT(&priv->fragsfree);
for (i = 0; i < MP_MAX_QUEUE_LEN; i++)
TAILQ_INSERT_TAIL(&priv->fragsfree, &priv->fragsmem[i], f_qent);
for (i = 0; i < NG_PPP_MAX_LINKS; i++)
priv->links[i].seq = MP_NOSEQ;
ng_callout_init(&priv->fragTimer);
mtx_init(&priv->rmtx, "ng_ppp_recv", NULL, MTX_DEF);
mtx_init(&priv->xmtx, "ng_ppp_xmit", NULL, MTX_DEF);
/* Done */
return (0);
}
/*
* Give our OK for a hook to be added
*/
static int
ng_ppp_newhook(node_p node, hook_p hook, const char *name)
{
const priv_p priv = NG_NODE_PRIVATE(node);
hook_p *hookPtr = NULL;
int linkNum = -1;
int hookIndex = -1;
/* Figure out which hook it is */
if (strncmp(name, NG_PPP_HOOK_LINK_PREFIX, /* a link hook? */
strlen(NG_PPP_HOOK_LINK_PREFIX)) == 0) {
const char *cp;
char *eptr;
cp = name + strlen(NG_PPP_HOOK_LINK_PREFIX);
if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
return (EINVAL);
linkNum = (int)strtoul(cp, &eptr, 10);
if (*eptr != '\0' || linkNum < 0 || linkNum >= NG_PPP_MAX_LINKS)
return (EINVAL);
hookPtr = &priv->links[linkNum].hook;
hookIndex = ~linkNum;
/* See if hook is already connected. */
if (*hookPtr != NULL)
return (EISCONN);
/* Disallow more than one link unless multilink is enabled. */
if (priv->links[linkNum].conf.enableLink &&
!priv->conf.enableMultilink && priv->numActiveLinks >= 1)
return (ENODEV);
} else { /* must be a non-link hook */
int i;
for (i = 0; ng_ppp_hook_names[i].name != NULL; i++) {
if (strcmp(name, ng_ppp_hook_names[i].name) == 0) {
hookPtr = &priv->hooks[i];
hookIndex = i;
break;
}
}
if (ng_ppp_hook_names[i].name == NULL)
return (EINVAL); /* no such hook */
/* See if hook is already connected */
if (*hookPtr != NULL)
return (EISCONN);
/* Every non-linkX hook have it's own function. */
NG_HOOK_SET_RCVDATA(hook, ng_ppp_hook_names[i].fn);
}
/* OK */
*hookPtr = hook;
NG_HOOK_SET_PRIVATE(hook, (void *)(intptr_t)hookIndex);
ng_ppp_update(node, 0);
return (0);
}
/*
* Receive a control message
*/
static int
ng_ppp_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_mesg *resp = NULL;
int error = 0;
struct ng_mesg *msg;
NGI_GET_MSG(item, msg);
switch (msg->header.typecookie) {
case NGM_PPP_COOKIE:
switch (msg->header.cmd) {
case NGM_PPP_SET_CONFIG:
{
struct ng_ppp_node_conf *const conf =
(struct ng_ppp_node_conf *)msg->data;
int i;
/* Check for invalid or illegal config */
if (msg->header.arglen != sizeof(*conf))
ERROUT(EINVAL);
if (!ng_ppp_config_valid(node, conf))
ERROUT(EINVAL);
/* Copy config */
priv->conf = conf->bund;
for (i = 0; i < NG_PPP_MAX_LINKS; i++)
priv->links[i].conf = conf->links[i];
ng_ppp_update(node, 1);
break;
}
case NGM_PPP_GET_CONFIG:
{
struct ng_ppp_node_conf *conf;
int i;
NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
if (resp == NULL)
ERROUT(ENOMEM);
conf = (struct ng_ppp_node_conf *)resp->data;
conf->bund = priv->conf;
for (i = 0; i < NG_PPP_MAX_LINKS; i++)
conf->links[i] = priv->links[i].conf;
break;
}
case NGM_PPP_GET_MP_STATE:
{
struct ng_ppp_mp_state *info;
int i;
NG_MKRESPONSE(resp, msg, sizeof(*info), M_NOWAIT);
if (resp == NULL)
ERROUT(ENOMEM);
info = (struct ng_ppp_mp_state *)resp->data;
bzero(info, sizeof(*info));
for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
if (priv->links[i].seq != MP_NOSEQ)
info->rseq[i] = priv->links[i].seq;
}
info->mseq = priv->mseq;
info->xseq = priv->xseq;
break;
}
case NGM_PPP_GET_LINK_STATS:
case NGM_PPP_CLR_LINK_STATS:
case NGM_PPP_GETCLR_LINK_STATS:
case NGM_PPP_GET_LINK_STATS64:
case NGM_PPP_GETCLR_LINK_STATS64:
{
struct ng_ppp_link_stat64 *stats;
uint16_t linkNum;
/* Process request. */
if (msg->header.arglen != sizeof(uint16_t))
ERROUT(EINVAL);
linkNum = *((uint16_t *) msg->data);
if (linkNum >= NG_PPP_MAX_LINKS
&& linkNum != NG_PPP_BUNDLE_LINKNUM)
ERROUT(EINVAL);
stats = (linkNum == NG_PPP_BUNDLE_LINKNUM) ?
&priv->bundleStats : &priv->links[linkNum].stats;
/* Make 64bit reply. */
if (msg->header.cmd == NGM_PPP_GET_LINK_STATS64 ||
msg->header.cmd == NGM_PPP_GETCLR_LINK_STATS64) {
NG_MKRESPONSE(resp, msg,
sizeof(struct ng_ppp_link_stat64), M_NOWAIT);
if (resp == NULL)
ERROUT(ENOMEM);
bcopy(stats, resp->data, sizeof(*stats));
} else
/* Make 32bit reply. */
if (msg->header.cmd == NGM_PPP_GET_LINK_STATS ||
msg->header.cmd == NGM_PPP_GETCLR_LINK_STATS) {
struct ng_ppp_link_stat *rs;
NG_MKRESPONSE(resp, msg,
sizeof(struct ng_ppp_link_stat), M_NOWAIT);
if (resp == NULL)
ERROUT(ENOMEM);
rs = (struct ng_ppp_link_stat *)resp->data;
/* Truncate 64->32 bits. */
rs->xmitFrames = stats->xmitFrames;
rs->xmitOctets = stats->xmitOctets;
rs->recvFrames = stats->recvFrames;
rs->recvOctets = stats->recvOctets;
rs->badProtos = stats->badProtos;
rs->runts = stats->runts;
rs->dupFragments = stats->dupFragments;
rs->dropFragments = stats->dropFragments;
}
/* Clear stats. */
if (msg->header.cmd != NGM_PPP_GET_LINK_STATS &&
msg->header.cmd != NGM_PPP_GET_LINK_STATS64)
bzero(stats, sizeof(*stats));
break;
}
default:
error = EINVAL;
break;
}
break;
case NGM_VJC_COOKIE:
{
/*
* Forward it to the vjc node. leave the
* old return address alone.
* If we have no hook, let NG_RESPOND_MSG
* clean up any remaining resources.
* Because we have no resp, the item will be freed
* along with anything it references. Don't
* let msg be freed twice.
*/
NGI_MSG(item) = msg; /* put it back in the item */
msg = NULL;
if ((lasthook = priv->hooks[HOOK_INDEX_VJC_IP])) {
NG_FWD_ITEM_HOOK(error, item, lasthook);
}
return (error);
}
default:
error = EINVAL;
break;
}
done:
NG_RESPOND_MSG(error, node, item, resp);
NG_FREE_MSG(msg);
return (error);
}
/*
* Destroy node
*/
static int
ng_ppp_shutdown(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
/* Stop fragment queue timer */
ng_ppp_stop_frag_timer(node);
/* Take down netgraph node */
ng_ppp_frag_reset(node);
mtx_destroy(&priv->rmtx);
mtx_destroy(&priv->xmtx);
bzero(priv, sizeof(*priv));
free(priv, M_NETGRAPH_PPP);
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node); /* let the node escape */
return (0);
}
/*
* Hook disconnection
*/
static int
ng_ppp_disconnect(hook_p hook)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
const int index = (intptr_t)NG_HOOK_PRIVATE(hook);
/* Zero out hook pointer */
if (index < 0)
priv->links[~index].hook = NULL;
else
priv->hooks[index] = NULL;
/* Update derived info (or go away if no hooks left). */
if (NG_NODE_NUMHOOKS(node) > 0)
ng_ppp_update(node, 0);
else if (NG_NODE_IS_VALID(node))
ng_rmnode_self(node);
return (0);
}
/*
* Proto layer
*/
/*
* Receive data on a hook inet.
*/
static int
ng_ppp_rcvdata_inet(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableIP) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, PROT_IP));
}
/*
* Receive data on a hook ipv6.
*/
static int
ng_ppp_rcvdata_ipv6(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableIPv6) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, PROT_IPV6));
}
/*
* Receive data on a hook atalk.
*/
static int
ng_ppp_rcvdata_atalk(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableAtalk) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, PROT_ATALK));
}
/*
* Receive data on a hook ipx
*/
static int
ng_ppp_rcvdata_ipx(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableIPX) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, PROT_IPX));
}
/*
* Receive data on a hook bypass
*/
static int
ng_ppp_rcvdata_bypass(hook_p hook, item_p item)
{
uint16_t linkNum;
uint16_t proto;
struct mbuf *m;
NGI_GET_M(item, m);
if (m->m_pkthdr.len < 4) {
NG_FREE_ITEM(item);
return (EINVAL);
}
if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
linkNum = be16dec(mtod(m, uint8_t *));
proto = be16dec(mtod(m, uint8_t *) + 2);
m_adj(m, 4);
NGI_M(item) = m;
if (linkNum == NG_PPP_BUNDLE_LINKNUM)
return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, proto));
else
return (ng_ppp_link_xmit(NG_HOOK_NODE(hook), item, proto,
linkNum, 0));
}
static int
ng_ppp_bypass(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
{
const priv_p priv = NG_NODE_PRIVATE(node);
uint16_t hdr[2];
struct mbuf *m;
int error;
if (priv->hooks[HOOK_INDEX_BYPASS] == NULL) {
NG_FREE_ITEM(item);
return (ENXIO);
}
/* Add 4-byte bypass header. */
hdr[0] = htons(linkNum);
hdr[1] = htons(proto);
NGI_GET_M(item, m);
if ((m = ng_ppp_prepend(m, &hdr, 4)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
NGI_M(item) = m;
/* Send packet out hook. */
NG_FWD_ITEM_HOOK(error, item, priv->hooks[HOOK_INDEX_BYPASS]);
return (error);
}
static int
ng_ppp_proto_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
{
const priv_p priv = NG_NODE_PRIVATE(node);
hook_p outHook = NULL;
int error;
#ifdef ALIGNED_POINTER
struct mbuf *m, *n;
NGI_GET_M(item, m);
if (!ALIGNED_POINTER(mtod(m, caddr_t), uint32_t)) {
n = m_defrag(m, M_NOWAIT);
if (n == NULL) {
m_freem(m);
NG_FREE_ITEM(item);
return (ENOBUFS);
}
m = n;
}
NGI_M(item) = m;
#endif /* ALIGNED_POINTER */
switch (proto) {
case PROT_IP:
if (priv->conf.enableIP)
outHook = priv->hooks[HOOK_INDEX_INET];
break;
case PROT_IPV6:
if (priv->conf.enableIPv6)
outHook = priv->hooks[HOOK_INDEX_IPV6];
break;
case PROT_ATALK:
if (priv->conf.enableAtalk)
outHook = priv->hooks[HOOK_INDEX_ATALK];
break;
case PROT_IPX:
if (priv->conf.enableIPX)
outHook = priv->hooks[HOOK_INDEX_IPX];
break;
}
if (outHook == NULL)
return (ng_ppp_bypass(node, item, proto, linkNum));
/* Send packet out hook. */
NG_FWD_ITEM_HOOK(error, item, outHook);
return (error);
}
/*
* Header compression layer
*/
static int
ng_ppp_hcomp_xmit(node_p node, item_p item, uint16_t proto)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (proto == PROT_IP &&
priv->conf.enableVJCompression &&
priv->vjCompHooked) {
int error;
/* Send packet out hook. */
NG_FWD_ITEM_HOOK(error, item, priv->hooks[HOOK_INDEX_VJC_IP]);
return (error);
}
return (ng_ppp_comp_xmit(node, item, proto));
}
/*
* Receive data on a hook vjc_comp.
*/
static int
ng_ppp_rcvdata_vjc_comp(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableVJCompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_comp_xmit(node, item, PROT_VJCOMP));
}
/*
* Receive data on a hook vjc_uncomp.
*/
static int
ng_ppp_rcvdata_vjc_uncomp(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableVJCompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_comp_xmit(node, item, PROT_VJUNCOMP));
}
/*
* Receive data on a hook vjc_vjip.
*/
static int
ng_ppp_rcvdata_vjc_vjip(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableVJCompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_comp_xmit(node, item, PROT_IP));
}
static int
ng_ppp_hcomp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (priv->conf.enableVJDecompression && priv->vjCompHooked) {
hook_p outHook = NULL;
switch (proto) {
case PROT_VJCOMP:
outHook = priv->hooks[HOOK_INDEX_VJC_COMP];
break;
case PROT_VJUNCOMP:
outHook = priv->hooks[HOOK_INDEX_VJC_UNCOMP];
break;
}
if (outHook) {
int error;
/* Send packet out hook. */
NG_FWD_ITEM_HOOK(error, item, outHook);
return (error);
}
}
return (ng_ppp_proto_recv(node, item, proto, linkNum));
}
/*
* Receive data on a hook vjc_ip.
*/
static int
ng_ppp_rcvdata_vjc_ip(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableVJDecompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_proto_recv(node, item, PROT_IP, NG_PPP_BUNDLE_LINKNUM));
}
/*
* Compression layer
*/
static int
ng_ppp_comp_xmit(node_p node, item_p item, uint16_t proto)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (priv->conf.enableCompression &&
proto < 0x4000 &&
proto != PROT_COMPD &&
proto != PROT_CRYPTD &&
priv->hooks[HOOK_INDEX_COMPRESS] != NULL) {
struct mbuf *m;
int error;
NGI_GET_M(item, m);
if ((m = ng_ppp_addproto(m, proto, 0)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
NGI_M(item) = m;
/* Send packet out hook. */
NG_FWD_ITEM_HOOK(error, item, priv->hooks[HOOK_INDEX_COMPRESS]);
return (error);
}
return (ng_ppp_crypt_xmit(node, item, proto));
}
/*
* Receive data on a hook compress.
*/
static int
ng_ppp_rcvdata_compress(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
uint16_t proto;
switch (priv->conf.enableCompression) {
case NG_PPP_COMPRESS_NONE:
NG_FREE_ITEM(item);
return (ENXIO);
case NG_PPP_COMPRESS_FULL:
{
struct mbuf *m;
NGI_GET_M(item, m);
if ((m = ng_ppp_cutproto(m, &proto)) == NULL) {
NG_FREE_ITEM(item);
return (EIO);
}
NGI_M(item) = m;
if (!PROT_VALID(proto)) {
NG_FREE_ITEM(item);
return (EIO);
}
}
break;
default:
proto = PROT_COMPD;
break;
}
return (ng_ppp_crypt_xmit(node, item, proto));
}
static int
ng_ppp_comp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (proto < 0x4000 &&
((proto == PROT_COMPD && priv->conf.enableDecompression) ||
priv->conf.enableDecompression == NG_PPP_DECOMPRESS_FULL) &&
priv->hooks[HOOK_INDEX_DECOMPRESS] != NULL) {
int error;
if (priv->conf.enableDecompression == NG_PPP_DECOMPRESS_FULL) {
struct mbuf *m;
NGI_GET_M(item, m);
if ((m = ng_ppp_addproto(m, proto, 0)) == NULL) {
NG_FREE_ITEM(item);
return (EIO);
}
NGI_M(item) = m;
}
/* Send packet out hook. */
NG_FWD_ITEM_HOOK(error, item,
priv->hooks[HOOK_INDEX_DECOMPRESS]);
return (error);
} else if (proto == PROT_COMPD) {
/* Disabled protos MUST be silently discarded, but
* unsupported MUST not. Let user-level decide this. */
return (ng_ppp_bypass(node, item, proto, linkNum));
}
return (ng_ppp_hcomp_recv(node, item, proto, linkNum));
}
/*
* Receive data on a hook decompress.
*/
static int
ng_ppp_rcvdata_decompress(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
uint16_t proto;
struct mbuf *m;
if (!priv->conf.enableDecompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
NGI_GET_M(item, m);
if ((m = ng_ppp_cutproto(m, &proto)) == NULL) {
NG_FREE_ITEM(item);
return (EIO);
}
NGI_M(item) = m;
if (!PROT_VALID(proto)) {
priv->bundleStats.badProtos++;
NG_FREE_ITEM(item);
return (EIO);
}
return (ng_ppp_hcomp_recv(node, item, proto, NG_PPP_BUNDLE_LINKNUM));
}
/*
* Encryption layer
*/
static int
ng_ppp_crypt_xmit(node_p node, item_p item, uint16_t proto)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (priv->conf.enableEncryption &&
proto < 0x4000 &&
proto != PROT_CRYPTD &&
priv->hooks[HOOK_INDEX_ENCRYPT] != NULL) {
struct mbuf *m;
int error;
NGI_GET_M(item, m);
if ((m = ng_ppp_addproto(m, proto, 0)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
NGI_M(item) = m;
/* Send packet out hook. */
NG_FWD_ITEM_HOOK(error, item, priv->hooks[HOOK_INDEX_ENCRYPT]);
return (error);
}
return (ng_ppp_mp_xmit(node, item, proto));
}
/*
* Receive data on a hook encrypt.
*/
static int
ng_ppp_rcvdata_encrypt(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->conf.enableEncryption) {
NG_FREE_ITEM(item);
return (ENXIO);
}
return (ng_ppp_mp_xmit(node, item, PROT_CRYPTD));
}
static int
ng_ppp_crypt_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (proto == PROT_CRYPTD) {
if (priv->conf.enableDecryption &&
priv->hooks[HOOK_INDEX_DECRYPT] != NULL) {
int error;
/* Send packet out hook. */
NG_FWD_ITEM_HOOK(error, item,
priv->hooks[HOOK_INDEX_DECRYPT]);
return (error);
} else {
/* Disabled protos MUST be silently discarded, but
* unsupported MUST not. Let user-level decide this. */
return (ng_ppp_bypass(node, item, proto, linkNum));
}
}
return (ng_ppp_comp_recv(node, item, proto, linkNum));
}
/*
* Receive data on a hook decrypt.
*/
static int
ng_ppp_rcvdata_decrypt(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
uint16_t proto;
struct mbuf *m;
if (!priv->conf.enableDecryption) {
NG_FREE_ITEM(item);
return (ENXIO);
}
NGI_GET_M(item, m);
if ((m = ng_ppp_cutproto(m, &proto)) == NULL) {
NG_FREE_ITEM(item);
return (EIO);
}
NGI_M(item) = m;
if (!PROT_VALID(proto)) {
priv->bundleStats.badProtos++;
NG_FREE_ITEM(item);
return (EIO);
}
return (ng_ppp_comp_recv(node, item, proto, NG_PPP_BUNDLE_LINKNUM));
}
/*
* Link layer
*/
static int
ng_ppp_link_xmit(node_p node, item_p item, uint16_t proto, uint16_t linkNum, int plen)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_link *link;
int len, error;
struct mbuf *m;
uint16_t mru;
/* Check if link correct. */
if (linkNum >= NG_PPP_MAX_LINKS) {
ERROUT(ENETDOWN);
}
/* Get link pointer (optimization). */
link = &priv->links[linkNum];
/* Check link status (if real). */
if (link->hook == NULL) {
ERROUT(ENETDOWN);
}
/* Extract mbuf. */
NGI_GET_M(item, m);
/* Check peer's MRU for this link. */
mru = link->conf.mru;
if (mru != 0 && m->m_pkthdr.len > mru) {
NG_FREE_M(m);
ERROUT(EMSGSIZE);
}
/* Prepend protocol number, possibly compressed. */
if ((m = ng_ppp_addproto(m, proto, link->conf.enableProtoComp)) ==
NULL) {
ERROUT(ENOBUFS);
}
/* Prepend address and control field (unless compressed). */
if (proto == PROT_LCP || !link->conf.enableACFComp) {
if ((m = ng_ppp_prepend(m, &ng_ppp_acf, 2)) == NULL)
ERROUT(ENOBUFS);
}
/* Deliver frame. */
len = m->m_pkthdr.len;
NG_FWD_NEW_DATA(error, item, link->hook, m);
mtx_lock(&priv->xmtx);
/* Update link stats. */
link->stats.xmitFrames++;
link->stats.xmitOctets += len;
/* Update bundle stats. */
if (plen > 0) {
priv->bundleStats.xmitFrames++;
priv->bundleStats.xmitOctets += plen;
}
/* Update 'bytes in queue' counter. */
if (error == 0) {
/* bytesInQueue and lastWrite required only for mp_strategy. */
if (priv->conf.enableMultilink && !priv->allLinksEqual &&
!priv->conf.enableRoundRobin) {
/* If queue was empty, then mark this time. */
if (link->bytesInQueue == 0)
getmicrouptime(&link->lastWrite);
link->bytesInQueue += len + MP_AVERAGE_LINK_OVERHEAD;
/* Limit max queue length to 50 pkts. BW can be defined
incorrectly and link may not signal overload. */
if (link->bytesInQueue > 50 * 1600)
link->bytesInQueue = 50 * 1600;
}
}
mtx_unlock(&priv->xmtx);
return (error);
done:
NG_FREE_ITEM(item);
return (error);
}
/*
* Receive data on a hook linkX.
*/
static int
ng_ppp_rcvdata(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
const int index = (intptr_t)NG_HOOK_PRIVATE(hook);
const uint16_t linkNum = (uint16_t)~index;
struct ng_ppp_link * const link = &priv->links[linkNum];
uint16_t proto;
struct mbuf *m;
int error = 0;
KASSERT(linkNum < NG_PPP_MAX_LINKS,
("%s: bogus index 0x%x", __func__, index));
NGI_GET_M(item, m);
mtx_lock(&priv->rmtx);
/* Stats */
link->stats.recvFrames++;
link->stats.recvOctets += m->m_pkthdr.len;
/* Strip address and control fields, if present. */
if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL)
ERROUT(ENOBUFS);
if (mtod(m, uint8_t *)[0] == 0xff &&
mtod(m, uint8_t *)[1] == 0x03)
m_adj(m, 2);
/* Get protocol number */
if ((m = ng_ppp_cutproto(m, &proto)) == NULL)
ERROUT(ENOBUFS);
NGI_M(item) = m; /* Put changed m back into item. */
if (!PROT_VALID(proto)) {
link->stats.badProtos++;
ERROUT(EIO);
}
/* LCP packets must go directly to bypass. */
if (proto >= 0xB000) {
mtx_unlock(&priv->rmtx);
return (ng_ppp_bypass(node, item, proto, linkNum));
}
/* Other packets are denied on a disabled link. */
if (!link->conf.enableLink)
ERROUT(ENXIO);
/* Proceed to multilink layer. Mutex will be unlocked inside. */
error = ng_ppp_mp_recv(node, item, proto, linkNum);
mtx_assert(&priv->rmtx, MA_NOTOWNED);
return (error);
done:
mtx_unlock(&priv->rmtx);
NG_FREE_ITEM(item);
return (error);
}
/*
* Multilink layer
*/
/*
* Handle an incoming multi-link fragment
*
* The fragment reassembly algorithm is somewhat complex. This is mainly
* because we are required not to reorder the reconstructed packets, yet
* fragments are only guaranteed to arrive in order on a per-link basis.
* In other words, when we have a complete packet ready, but the previous
* packet is still incomplete, we have to decide between delivering the
* complete packet and throwing away the incomplete one, or waiting to
* see if the remainder of the incomplete one arrives, at which time we
* can deliver both packets, in order.
*
* This problem is exacerbated by "sequence number slew", which is when
* the sequence numbers coming in from different links are far apart from
* each other. In particular, certain unnamed equipment (*cough* Ascend)
* has been seen to generate sequence number slew of up to 10 on an ISDN
* 2B-channel MP link. There is nothing invalid about sequence number slew
* but it makes the reasssembly process have to work harder.
*
* However, the peer is required to transmit fragments in order on each
* link. That means if we define MSEQ as the minimum over all links of
* the highest sequence number received on that link, then we can always
* give up any hope of receiving a fragment with sequence number < MSEQ in
* the future (all of this using 'wraparound' sequence number space).
* Therefore we can always immediately throw away incomplete packets
* missing fragments with sequence numbers < MSEQ.
*
* Here is an overview of our algorithm:
*
* o Received fragments are inserted into a queue, for which we
* maintain these invariants between calls to this function:
*
* - Fragments are ordered in the queue by sequence number
* - If a complete packet is at the head of the queue, then
* the first fragment in the packet has seq# > MSEQ + 1
* (otherwise, we could deliver it immediately)
* - If any fragments have seq# < MSEQ, then they are necessarily
* part of a packet whose missing seq#'s are all > MSEQ (otherwise,
* we can throw them away because they'll never be completed)
* - The queue contains at most MP_MAX_QUEUE_LEN fragments
*
* o We have a periodic timer that checks the queue for the first
* complete packet that has been sitting in the queue "too long".
* When one is detected, all previous (incomplete) fragments are
* discarded, their missing fragments are declared lost and MSEQ
* is increased.
*
* o If we recieve a fragment with seq# < MSEQ, we throw it away
* because we've already delcared it lost.
*
* This assumes linkNum != NG_PPP_BUNDLE_LINKNUM.
*/
static int
ng_ppp_mp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_link *const link = &priv->links[linkNum];
struct ng_ppp_frag *frag;
struct ng_ppp_frag *qent;
int i, diff, inserted;
struct mbuf *m;
int error = 0;
if ((!priv->conf.enableMultilink) || proto != PROT_MP) {
/* Stats */
priv->bundleStats.recvFrames++;
priv->bundleStats.recvOctets += NGI_M(item)->m_pkthdr.len;
mtx_unlock(&priv->rmtx);
return (ng_ppp_crypt_recv(node, item, proto, linkNum));
}
NGI_GET_M(item, m);
/* Get a new frag struct from the free queue */
if ((frag = TAILQ_FIRST(&priv->fragsfree)) == NULL) {
printf("No free fragments headers in ng_ppp!\n");
NG_FREE_M(m);
goto process;
}
/* Extract fragment information from MP header */
if (priv->conf.recvShortSeq) {
uint16_t shdr;
if (m->m_pkthdr.len < 2) {
link->stats.runts++;
NG_FREE_M(m);
ERROUT(EINVAL);
}
if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL)
ERROUT(ENOBUFS);
shdr = be16dec(mtod(m, void *));
frag->seq = MP_SHORT_EXTEND(shdr);
frag->first = (shdr & MP_SHORT_FIRST_FLAG) != 0;
frag->last = (shdr & MP_SHORT_LAST_FLAG) != 0;
diff = MP_SHORT_SEQ_DIFF(frag->seq, priv->mseq);
m_adj(m, 2);
} else {
uint32_t lhdr;
if (m->m_pkthdr.len < 4) {
link->stats.runts++;
NG_FREE_M(m);
ERROUT(EINVAL);
}
if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
ERROUT(ENOBUFS);
lhdr = be32dec(mtod(m, void *));
frag->seq = MP_LONG_EXTEND(lhdr);
frag->first = (lhdr & MP_LONG_FIRST_FLAG) != 0;
frag->last = (lhdr & MP_LONG_LAST_FLAG) != 0;
diff = MP_LONG_SEQ_DIFF(frag->seq, priv->mseq);
m_adj(m, 4);
}
frag->data = m;
getmicrouptime(&frag->timestamp);
/* If sequence number is < MSEQ, we've already declared this
fragment as lost, so we have no choice now but to drop it */
if (diff < 0) {
link->stats.dropFragments++;
NG_FREE_M(m);
ERROUT(0);
}
/* Update highest received sequence number on this link and MSEQ */
priv->mseq = link->seq = frag->seq;
for (i = 0; i < priv->numActiveLinks; i++) {
struct ng_ppp_link *const alink =
&priv->links[priv->activeLinks[i]];
if (MP_RECV_SEQ_DIFF(priv, alink->seq, priv->mseq) < 0)
priv->mseq = alink->seq;
}
/* Remove frag struct from free queue. */
TAILQ_REMOVE(&priv->fragsfree, frag, f_qent);
/* Add fragment to queue, which is sorted by sequence number */
inserted = 0;
TAILQ_FOREACH_REVERSE(qent, &priv->frags, ng_ppp_fraglist, f_qent) {
diff = MP_RECV_SEQ_DIFF(priv, frag->seq, qent->seq);
if (diff > 0) {
TAILQ_INSERT_AFTER(&priv->frags, qent, frag, f_qent);
inserted = 1;
break;
} else if (diff == 0) { /* should never happen! */
link->stats.dupFragments++;
NG_FREE_M(frag->data);
TAILQ_INSERT_HEAD(&priv->fragsfree, frag, f_qent);
ERROUT(EINVAL);
}
}
if (!inserted)
TAILQ_INSERT_HEAD(&priv->frags, frag, f_qent);
process:
/* Process the queue */
/* NOTE: rmtx will be unlocked for sending time! */
error = ng_ppp_frag_process(node, item);
mtx_unlock(&priv->rmtx);
return (error);
done:
mtx_unlock(&priv->rmtx);
NG_FREE_ITEM(item);
return (error);
}
/************************************************************************
HELPER STUFF
************************************************************************/
/*
* If new mseq > current then set it and update all active links
*/
static void
ng_ppp_bump_mseq(node_p node, int32_t new_mseq)
{
const priv_p priv = NG_NODE_PRIVATE(node);
int i;
if (MP_RECV_SEQ_DIFF(priv, priv->mseq, new_mseq) < 0) {
priv->mseq = new_mseq;
for (i = 0; i < priv->numActiveLinks; i++) {
struct ng_ppp_link *const alink =
&priv->links[priv->activeLinks[i]];
if (MP_RECV_SEQ_DIFF(priv,
alink->seq, new_mseq) < 0)
alink->seq = new_mseq;
}
}
}
/*
* Examine our list of fragments, and determine if there is a
* complete and deliverable packet at the head of the list.
* Return 1 if so, zero otherwise.
*/
static int
ng_ppp_check_packet(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_frag *qent, *qnext;
/* Check for empty queue */
if (TAILQ_EMPTY(&priv->frags))
return (0);
/* Check first fragment is the start of a deliverable packet */
qent = TAILQ_FIRST(&priv->frags);
if (!qent->first || MP_RECV_SEQ_DIFF(priv, qent->seq, priv->mseq) > 1)
return (0);
/* Check that all the fragments are there */
while (!qent->last) {
qnext = TAILQ_NEXT(qent, f_qent);
if (qnext == NULL) /* end of queue */
return (0);
if (qnext->seq != MP_NEXT_RECV_SEQ(priv, qent->seq))
return (0);
qent = qnext;
}
/* Got one */
return (1);
}
/*
* Pull a completed packet off the head of the incoming fragment queue.
* This assumes there is a completed packet there to pull off.
*/
static void
ng_ppp_get_packet(node_p node, struct mbuf **mp)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_frag *qent, *qnext;
struct mbuf *m = NULL, *tail;
qent = TAILQ_FIRST(&priv->frags);
KASSERT(!TAILQ_EMPTY(&priv->frags) && qent->first,
("%s: no packet", __func__));
for (tail = NULL; qent != NULL; qent = qnext) {
qnext = TAILQ_NEXT(qent, f_qent);
KASSERT(!TAILQ_EMPTY(&priv->frags),
("%s: empty q", __func__));
TAILQ_REMOVE(&priv->frags, qent, f_qent);
if (tail == NULL)
tail = m = qent->data;
else {
m->m_pkthdr.len += qent->data->m_pkthdr.len;
tail->m_next = qent->data;
}
while (tail->m_next != NULL)
tail = tail->m_next;
if (qent->last) {
qnext = NULL;
/* Bump MSEQ if necessary */
ng_ppp_bump_mseq(node, qent->seq);
}
TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
}
*mp = m;
}
/*
* Trim fragments from the queue whose packets can never be completed.
* This assumes a complete packet is NOT at the beginning of the queue.
* Returns 1 if fragments were removed, zero otherwise.
*/
static int
ng_ppp_frag_trim(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_frag *qent, *qnext = NULL;
int removed = 0;
/* Scan for "dead" fragments and remove them */
while (1) {
int dead = 0;
/* If queue is empty, we're done */
if (TAILQ_EMPTY(&priv->frags))
break;
/* Determine whether first fragment can ever be completed */
TAILQ_FOREACH(qent, &priv->frags, f_qent) {
if (MP_RECV_SEQ_DIFF(priv, qent->seq, priv->mseq) >= 0)
break;
qnext = TAILQ_NEXT(qent, f_qent);
KASSERT(qnext != NULL,
("%s: last frag < MSEQ?", __func__));
if (qnext->seq != MP_NEXT_RECV_SEQ(priv, qent->seq)
|| qent->last || qnext->first) {
dead = 1;
break;
}
}
if (!dead)
break;
/* Remove fragment and all others in the same packet */
while ((qent = TAILQ_FIRST(&priv->frags)) != qnext) {
KASSERT(!TAILQ_EMPTY(&priv->frags),
("%s: empty q", __func__));
priv->bundleStats.dropFragments++;
TAILQ_REMOVE(&priv->frags, qent, f_qent);
NG_FREE_M(qent->data);
TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
removed = 1;
}
}
return (removed);
}
/*
* Drop fragments on queue overflow.
* Returns 1 if fragments were removed, zero otherwise.
*/
static int
ng_ppp_frag_drop(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
/* Check queue length */
if (TAILQ_EMPTY(&priv->fragsfree)) {
struct ng_ppp_frag *qent;
/* Get oldest fragment */
KASSERT(!TAILQ_EMPTY(&priv->frags),
("%s: empty q", __func__));
qent = TAILQ_FIRST(&priv->frags);
/* Bump MSEQ if necessary */
ng_ppp_bump_mseq(node, qent->seq);
/* Drop it */
priv->bundleStats.dropFragments++;
TAILQ_REMOVE(&priv->frags, qent, f_qent);
NG_FREE_M(qent->data);
TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
return (1);
}
return (0);
}
/*
* Run the queue, restoring the queue invariants
*/
static int
ng_ppp_frag_process(node_p node, item_p oitem)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct mbuf *m;
item_p item;
uint16_t proto;
do {
/* Deliver any deliverable packets */
while (ng_ppp_check_packet(node)) {
ng_ppp_get_packet(node, &m);
if ((m = ng_ppp_cutproto(m, &proto)) == NULL)
continue;
if (!PROT_VALID(proto)) {
priv->bundleStats.badProtos++;
NG_FREE_M(m);
continue;
}
if (oitem) { /* If original item present - reuse it. */
item = oitem;
oitem = NULL;
NGI_M(item) = m;
} else {
item = ng_package_data(m, NG_NOFLAGS);
}
if (item != NULL) {
/* Stats */
priv->bundleStats.recvFrames++;
priv->bundleStats.recvOctets +=
NGI_M(item)->m_pkthdr.len;
/* Drop mutex for the sending time.
* Priv may change, but we are ready!
*/
mtx_unlock(&priv->rmtx);
ng_ppp_crypt_recv(node, item, proto,
NG_PPP_BUNDLE_LINKNUM);
mtx_lock(&priv->rmtx);
}
}
/* Delete dead fragments and try again */
} while (ng_ppp_frag_trim(node) || ng_ppp_frag_drop(node));
/* If we haven't reused original item - free it. */
if (oitem) NG_FREE_ITEM(oitem);
/* Done */
return (0);
}
/*
* Check for 'stale' completed packets that need to be delivered
*
* If a link goes down or has a temporary failure, MSEQ can get
* "stuck", because no new incoming fragments appear on that link.
* This can cause completed packets to never get delivered if
* their sequence numbers are all > MSEQ + 1.
*
* This routine checks how long all of the completed packets have
* been sitting in the queue, and if too long, removes fragments
* from the queue and increments MSEQ to allow them to be delivered.
*/
static void
ng_ppp_frag_checkstale(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_frag *qent, *beg, *end;
struct timeval now, age;
struct mbuf *m;
int seq;
item_p item;
int endseq;
uint16_t proto;
now.tv_sec = 0; /* uninitialized state */
while (1) {
/* If queue is empty, we're done */
if (TAILQ_EMPTY(&priv->frags))
break;
/* Find the first complete packet in the queue */
beg = end = NULL;
seq = TAILQ_FIRST(&priv->frags)->seq;
TAILQ_FOREACH(qent, &priv->frags, f_qent) {
if (qent->first)
beg = qent;
else if (qent->seq != seq)
beg = NULL;
if (beg != NULL && qent->last) {
end = qent;
break;
}
seq = MP_NEXT_RECV_SEQ(priv, seq);
}
/* If none found, exit */
if (end == NULL)
break;
/* Get current time (we assume we've been up for >= 1 second) */
if (now.tv_sec == 0)
getmicrouptime(&now);
/* Check if packet has been queued too long */
age = now;
timevalsub(&age, &beg->timestamp);
if (timevalcmp(&age, &ng_ppp_max_staleness, < ))
break;
/* Throw away junk fragments in front of the completed packet */
while ((qent = TAILQ_FIRST(&priv->frags)) != beg) {
KASSERT(!TAILQ_EMPTY(&priv->frags),
("%s: empty q", __func__));
priv->bundleStats.dropFragments++;
TAILQ_REMOVE(&priv->frags, qent, f_qent);
NG_FREE_M(qent->data);
TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
}
/* Extract completed packet */
endseq = end->seq;
ng_ppp_get_packet(node, &m);
if ((m = ng_ppp_cutproto(m, &proto)) == NULL)
continue;
if (!PROT_VALID(proto)) {
priv->bundleStats.badProtos++;
NG_FREE_M(m);
continue;
}
/* Deliver packet */
if ((item = ng_package_data(m, NG_NOFLAGS)) != NULL) {
/* Stats */
priv->bundleStats.recvFrames++;
priv->bundleStats.recvOctets += NGI_M(item)->m_pkthdr.len;
ng_ppp_crypt_recv(node, item, proto,
NG_PPP_BUNDLE_LINKNUM);
}
}
}
/*
* Periodically call ng_ppp_frag_checkstale()
*/
static void
ng_ppp_frag_timeout(node_p node, hook_p hook, void *arg1, int arg2)
{
/* XXX: is this needed? */
if (NG_NODE_NOT_VALID(node))
return;
/* Scan the fragment queue */
ng_ppp_frag_checkstale(node);
/* Start timer again */
ng_ppp_start_frag_timer(node);
}
/*
* Deliver a frame out on the bundle, i.e., figure out how to fragment
* the frame across the individual PPP links and do so.
*/
static int
ng_ppp_mp_xmit(node_p node, item_p item, uint16_t proto)
{
const priv_p priv = NG_NODE_PRIVATE(node);
const int hdr_len = priv->conf.xmitShortSeq ? 2 : 4;
int distrib[NG_PPP_MAX_LINKS];
int firstFragment;
int activeLinkNum;
struct mbuf *m;
int plen;
int frags;
int32_t seq;
/* At least one link must be active */
if (priv->numActiveLinks == 0) {
NG_FREE_ITEM(item);
return (ENETDOWN);
}
/* Save length for later stats. */
plen = NGI_M(item)->m_pkthdr.len;
if (!priv->conf.enableMultilink) {
return (ng_ppp_link_xmit(node, item, proto,
priv->activeLinks[0], plen));
}
/* Check peer's MRRU for this bundle. */
if (plen > priv->conf.mrru) {
NG_FREE_ITEM(item);
return (EMSGSIZE);
}
/* Extract mbuf. */
NGI_GET_M(item, m);
/* Prepend protocol number, possibly compressed. */
if ((m = ng_ppp_addproto(m, proto, 1)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
/* Clear distribution plan */
bzero(&distrib, priv->numActiveLinks * sizeof(distrib[0]));
mtx_lock(&priv->xmtx);
/* Round-robin strategy */
if (priv->conf.enableRoundRobin) {
activeLinkNum = priv->lastLink++ % priv->numActiveLinks;
distrib[activeLinkNum] = m->m_pkthdr.len;
goto deliver;
}
/* Strategy when all links are equivalent (optimize the common case) */
if (priv->allLinksEqual) {
int numFrags, fraction, remain;
int i;
/* Calculate optimal fragment count */
numFrags = priv->numActiveLinks;
if (numFrags > m->m_pkthdr.len / MP_MIN_FRAG_LEN)
numFrags = m->m_pkthdr.len / MP_MIN_FRAG_LEN;
if (numFrags == 0)
numFrags = 1;
fraction = m->m_pkthdr.len / numFrags;
remain = m->m_pkthdr.len - (fraction * numFrags);
/* Assign distribution */
for (i = 0; i < numFrags; i++) {
distrib[priv->lastLink++ % priv->numActiveLinks]
= fraction + (((remain--) > 0)?1:0);
}
goto deliver;
}
/* Strategy when all links are not equivalent */
ng_ppp_mp_strategy(node, m->m_pkthdr.len, distrib);
deliver:
/* Estimate fragments count */
frags = 0;
for (activeLinkNum = priv->numActiveLinks - 1;
activeLinkNum >= 0; activeLinkNum--) {
const uint16_t linkNum = priv->activeLinks[activeLinkNum];
struct ng_ppp_link *const link = &priv->links[linkNum];
frags += (distrib[activeLinkNum] + link->conf.mru - hdr_len - 1) /
(link->conf.mru - hdr_len);
}
/* Get out initial sequence number */
seq = priv->xseq;
/* Update next sequence number */
if (priv->conf.xmitShortSeq) {
priv->xseq = (seq + frags) & MP_SHORT_SEQ_MASK;
} else {
priv->xseq = (seq + frags) & MP_LONG_SEQ_MASK;
}
mtx_unlock(&priv->xmtx);
/* Send alloted portions of frame out on the link(s) */
for (firstFragment = 1, activeLinkNum = priv->numActiveLinks - 1;
activeLinkNum >= 0; activeLinkNum--) {
const uint16_t linkNum = priv->activeLinks[activeLinkNum];
struct ng_ppp_link *const link = &priv->links[linkNum];
/* Deliver fragment(s) out the next link */
for ( ; distrib[activeLinkNum] > 0; firstFragment = 0) {
int len, lastFragment, error;
struct mbuf *m2;
/* Calculate fragment length; don't exceed link MTU */
len = distrib[activeLinkNum];
if (len > link->conf.mru - hdr_len)
len = link->conf.mru - hdr_len;
distrib[activeLinkNum] -= len;
lastFragment = (len == m->m_pkthdr.len);
/* Split off next fragment as "m2" */
m2 = m;
if (!lastFragment) {
struct mbuf *n = m_split(m, len, M_DONTWAIT);
if (n == NULL) {
NG_FREE_M(m);
if (firstFragment)
NG_FREE_ITEM(item);
return (ENOMEM);
}
m_tag_copy_chain(n, m, M_DONTWAIT);
m = n;
}
/* Prepend MP header */
if (priv->conf.xmitShortSeq) {
uint16_t shdr;
shdr = seq;
seq = (seq + 1) & MP_SHORT_SEQ_MASK;
if (firstFragment)
shdr |= MP_SHORT_FIRST_FLAG;
if (lastFragment)
shdr |= MP_SHORT_LAST_FLAG;
shdr = htons(shdr);
m2 = ng_ppp_prepend(m2, &shdr, 2);
} else {
uint32_t lhdr;
lhdr = seq;
seq = (seq + 1) & MP_LONG_SEQ_MASK;
if (firstFragment)
lhdr |= MP_LONG_FIRST_FLAG;
if (lastFragment)
lhdr |= MP_LONG_LAST_FLAG;
lhdr = htonl(lhdr);
m2 = ng_ppp_prepend(m2, &lhdr, 4);
}
if (m2 == NULL) {
if (!lastFragment)
m_freem(m);
if (firstFragment)
NG_FREE_ITEM(item);
return (ENOBUFS);
}
/* Send fragment */
if (firstFragment) {
NGI_M(item) = m2; /* Reuse original item. */
} else {
item = ng_package_data(m2, NG_NOFLAGS);
}
if (item != NULL) {
error = ng_ppp_link_xmit(node, item, PROT_MP,
linkNum, (firstFragment?plen:0));
if (error != 0) {
if (!lastFragment)
NG_FREE_M(m);
return (error);
}
}
}
}
/* Done */
return (0);
}
/*
* Computing the optimal fragmentation
* -----------------------------------
*
* This routine tries to compute the optimal fragmentation pattern based
* on each link's latency, bandwidth, and calculated additional latency.
* The latter quantity is the additional latency caused by previously
* written data that has not been transmitted yet.
*
* This algorithm is only useful when not all of the links have the
* same latency and bandwidth values.
*
* The essential idea is to make the last bit of each fragment of the
* frame arrive at the opposite end at the exact same time. This greedy
* algorithm is optimal, in that no other scheduling could result in any
* packet arriving any sooner unless packets are delivered out of order.
*
* Suppose link i has bandwidth b_i (in tens of bytes per milisecond) and
* latency l_i (in miliseconds). Consider the function function f_i(t)
* which is equal to the number of bytes that will have arrived at
* the peer after t miliseconds if we start writing continuously at
* time t = 0. Then f_i(t) = b_i * (t - l_i) = ((b_i * t) - (l_i * b_i).
* That is, f_i(t) is a line with slope b_i and y-intersect -(l_i * b_i).
* Note that the y-intersect is always <= zero because latency can't be
* negative. Note also that really the function is f_i(t) except when
* f_i(t) is negative, in which case the function is zero. To take
* care of this, let Q_i(t) = { if (f_i(t) > 0) return 1; else return 0; }.
* So the actual number of bytes that will have arrived at the peer after
* t miliseconds is f_i(t) * Q_i(t).
*
* At any given time, each link has some additional latency a_i >= 0
* due to previously written fragment(s) which are still in the queue.
* This value is easily computed from the time since last transmission,
* the previous latency value, the number of bytes written, and the
* link's bandwidth.
*
* Assume that l_i includes any a_i already, and that the links are
* sorted by latency, so that l_i <= l_{i+1}.
*
* Let N be the total number of bytes in the current frame we are sending.
*
* Suppose we were to start writing bytes at time t = 0 on all links
* simultaneously, which is the most we can possibly do. Then let
* F(t) be equal to the total number of bytes received by the peer
* after t miliseconds. Then F(t) = Sum_i (f_i(t) * Q_i(t)).
*
* Our goal is simply this: fragment the frame across the links such
* that the peer is able to reconstruct the completed frame as soon as
* possible, i.e., at the least possible value of t. Call this value t_0.
*
* Then it follows that F(t_0) = N. Our strategy is first to find the value
* of t_0, and then deduce how many bytes to write to each link.
*
* Rewriting F(t_0):
*
* t_0 = ( N + Sum_i ( l_i * b_i * Q_i(t_0) ) ) / Sum_i ( b_i * Q_i(t_0) )
*
* Now, we note that Q_i(t) is constant for l_i <= t <= l_{i+1}. t_0 will
* lie in one of these ranges. To find it, we just need to find the i such
* that F(l_i) <= N <= F(l_{i+1}). Then we compute all the constant values
* for Q_i() in this range, plug in the remaining values, solving for t_0.
*
* Once t_0 is known, then the number of bytes to send on link i is
* just f_i(t_0) * Q_i(t_0).
*
* In other words, we start allocating bytes to the links one at a time.
* We keep adding links until the frame is completely sent. Some links
* may not get any bytes because their latency is too high.
*
* Is all this work really worth the trouble? Depends on the situation.
* The bigger the ratio of computer speed to link speed, and the more
* important total bundle latency is (e.g., for interactive response time),
* the more it's worth it. There is however the cost of calling this
* function for every frame. The running time is O(n^2) where n is the
* number of links that receive a non-zero number of bytes.
*
* Since latency is measured in miliseconds, the "resolution" of this
* algorithm is one milisecond.
*
* To avoid this algorithm altogether, configure all links to have the
* same latency and bandwidth.
*/
static void
ng_ppp_mp_strategy(node_p node, int len, int *distrib)
{
const priv_p priv = NG_NODE_PRIVATE(node);
int latency[NG_PPP_MAX_LINKS];
int sortByLatency[NG_PPP_MAX_LINKS];
int activeLinkNum;
int t0, total, topSum, botSum;
struct timeval now;
int i, numFragments;
/* If only one link, this gets real easy */
if (priv->numActiveLinks == 1) {
distrib[0] = len;
return;
}
/* Get current time */
getmicrouptime(&now);
/* Compute latencies for each link at this point in time */
for (activeLinkNum = 0;
activeLinkNum < priv->numActiveLinks; activeLinkNum++) {
struct ng_ppp_link *alink;
struct timeval diff;
int xmitBytes;
/* Start with base latency value */
alink = &priv->links[priv->activeLinks[activeLinkNum]];
latency[activeLinkNum] = alink->latency;
sortByLatency[activeLinkNum] = activeLinkNum; /* see below */
/* Any additional latency? */
if (alink->bytesInQueue == 0)
continue;
/* Compute time delta since last write */
diff = now;
timevalsub(&diff, &alink->lastWrite);
/* alink->bytesInQueue will be changed, mark change time. */
alink->lastWrite = now;
if (now.tv_sec < 0 || diff.tv_sec >= 10) { /* sanity */
alink->bytesInQueue = 0;
continue;
}
/* How many bytes could have transmitted since last write? */
xmitBytes = (alink->conf.bandwidth * 10 * diff.tv_sec)
+ (alink->conf.bandwidth * (diff.tv_usec / 1000)) / 100;
alink->bytesInQueue -= xmitBytes;
if (alink->bytesInQueue < 0)
alink->bytesInQueue = 0;
else
latency[activeLinkNum] +=
(100 * alink->bytesInQueue) / alink->conf.bandwidth;
}
/* Sort active links by latency */
qsort_r(sortByLatency,
priv->numActiveLinks, sizeof(*sortByLatency), latency, ng_ppp_intcmp);
/* Find the interval we need (add links in sortByLatency[] order) */
for (numFragments = 1;
numFragments < priv->numActiveLinks; numFragments++) {
for (total = i = 0; i < numFragments; i++) {
int flowTime;
flowTime = latency[sortByLatency[numFragments]]
- latency[sortByLatency[i]];
total += ((flowTime * priv->links[
priv->activeLinks[sortByLatency[i]]].conf.bandwidth)
+ 99) / 100;
}
if (total >= len)
break;
}
/* Solve for t_0 in that interval */
for (topSum = botSum = i = 0; i < numFragments; i++) {
int bw = priv->links[
priv->activeLinks[sortByLatency[i]]].conf.bandwidth;
topSum += latency[sortByLatency[i]] * bw; /* / 100 */
botSum += bw; /* / 100 */
}
t0 = ((len * 100) + topSum + botSum / 2) / botSum;
/* Compute f_i(t_0) all i */
for (total = i = 0; i < numFragments; i++) {
int bw = priv->links[
priv->activeLinks[sortByLatency[i]]].conf.bandwidth;
distrib[sortByLatency[i]] =
(bw * (t0 - latency[sortByLatency[i]]) + 50) / 100;
total += distrib[sortByLatency[i]];
}
/* Deal with any rounding error */
if (total < len) {
struct ng_ppp_link *fastLink =
&priv->links[priv->activeLinks[sortByLatency[0]]];
int fast = 0;
/* Find the fastest link */
for (i = 1; i < numFragments; i++) {
struct ng_ppp_link *const link =
&priv->links[priv->activeLinks[sortByLatency[i]]];
if (link->conf.bandwidth > fastLink->conf.bandwidth) {
fast = i;
fastLink = link;
}
}
distrib[sortByLatency[fast]] += len - total;
} else while (total > len) {
struct ng_ppp_link *slowLink =
&priv->links[priv->activeLinks[sortByLatency[0]]];
int delta, slow = 0;
/* Find the slowest link that still has bytes to remove */
for (i = 1; i < numFragments; i++) {
struct ng_ppp_link *const link =
&priv->links[priv->activeLinks[sortByLatency[i]]];
if (distrib[sortByLatency[slow]] == 0
|| (distrib[sortByLatency[i]] > 0
&& link->conf.bandwidth <
slowLink->conf.bandwidth)) {
slow = i;
slowLink = link;
}
}
delta = total - len;
if (delta > distrib[sortByLatency[slow]])
delta = distrib[sortByLatency[slow]];
distrib[sortByLatency[slow]] -= delta;
total -= delta;
}
}
/*
* Compare two integers
*/
static int
ng_ppp_intcmp(void *latency, const void *v1, const void *v2)
{
const int index1 = *((const int *) v1);
const int index2 = *((const int *) v2);
return ((int *)latency)[index1] - ((int *)latency)[index2];
}
/*
* Prepend a possibly compressed PPP protocol number in front of a frame
*/
static struct mbuf *
ng_ppp_addproto(struct mbuf *m, uint16_t proto, int compOK)
{
if (compOK && PROT_COMPRESSABLE(proto)) {
uint8_t pbyte = (uint8_t)proto;
return ng_ppp_prepend(m, &pbyte, 1);
} else {
uint16_t pword = htons((uint16_t)proto);
return ng_ppp_prepend(m, &pword, 2);
}
}
/*
* Cut a possibly compressed PPP protocol number from the front of a frame.
*/
static struct mbuf *
ng_ppp_cutproto(struct mbuf *m, uint16_t *proto)
{
*proto = 0;
if (m->m_len < 1 && (m = m_pullup(m, 1)) == NULL)
return (NULL);
*proto = *mtod(m, uint8_t *);
m_adj(m, 1);
if (!PROT_VALID(*proto)) {
if (m->m_len < 1 && (m = m_pullup(m, 1)) == NULL)
return (NULL);
*proto = (*proto << 8) + *mtod(m, uint8_t *);
m_adj(m, 1);
}
return (m);
}
/*
* Prepend some bytes to an mbuf.
*/
static struct mbuf *
ng_ppp_prepend(struct mbuf *m, const void *buf, int len)
{
M_PREPEND(m, len, M_DONTWAIT);
if (m == NULL || (m->m_len < len && (m = m_pullup(m, len)) == NULL))
return (NULL);
bcopy(buf, mtod(m, uint8_t *), len);
return (m);
}
/*
* Update private information that is derived from other private information
*/
static void
ng_ppp_update(node_p node, int newConf)
{
const priv_p priv = NG_NODE_PRIVATE(node);
int i;
/* Update active status for VJ Compression */
priv->vjCompHooked = priv->hooks[HOOK_INDEX_VJC_IP] != NULL
&& priv->hooks[HOOK_INDEX_VJC_COMP] != NULL
&& priv->hooks[HOOK_INDEX_VJC_UNCOMP] != NULL
&& priv->hooks[HOOK_INDEX_VJC_VJIP] != NULL;
/* Increase latency for each link an amount equal to one MP header */
if (newConf) {
for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
int hdrBytes;
if (priv->links[i].conf.bandwidth == 0)
continue;
hdrBytes = MP_AVERAGE_LINK_OVERHEAD
+ (priv->links[i].conf.enableACFComp ? 0 : 2)
+ (priv->links[i].conf.enableProtoComp ? 1 : 2)
+ (priv->conf.xmitShortSeq ? 2 : 4);
priv->links[i].latency =
priv->links[i].conf.latency +
(hdrBytes / priv->links[i].conf.bandwidth + 50) / 100;
}
}
/* Update list of active links */
bzero(&priv->activeLinks, sizeof(priv->activeLinks));
priv->numActiveLinks = 0;
priv->allLinksEqual = 1;
for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
struct ng_ppp_link *const link = &priv->links[i];
/* Is link active? */
if (link->conf.enableLink && link->hook != NULL) {
struct ng_ppp_link *link0;
/* Add link to list of active links */
priv->activeLinks[priv->numActiveLinks++] = i;
link0 = &priv->links[priv->activeLinks[0]];
/* Determine if all links are still equal */
if (link->latency != link0->latency
|| link->conf.bandwidth != link0->conf.bandwidth)
priv->allLinksEqual = 0;
/* Initialize rec'd sequence number */
if (link->seq == MP_NOSEQ) {
link->seq = (link == link0) ?
MP_INITIAL_SEQ : link0->seq;
}
} else
link->seq = MP_NOSEQ;
}
/* Update MP state as multi-link is active or not */
if (priv->conf.enableMultilink && priv->numActiveLinks > 0)
ng_ppp_start_frag_timer(node);
else {
ng_ppp_stop_frag_timer(node);
ng_ppp_frag_reset(node);
priv->xseq = MP_INITIAL_SEQ;
priv->mseq = MP_INITIAL_SEQ;
for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
struct ng_ppp_link *const link = &priv->links[i];
bzero(&link->lastWrite, sizeof(link->lastWrite));
link->bytesInQueue = 0;
link->seq = MP_NOSEQ;
}
}
}
/*
* Determine if a new configuration would represent a valid change
* from the current configuration and link activity status.
*/
static int
ng_ppp_config_valid(node_p node, const struct ng_ppp_node_conf *newConf)
{
const priv_p priv = NG_NODE_PRIVATE(node);
int i, newNumLinksActive;
/* Check per-link config and count how many links would be active */
for (newNumLinksActive = i = 0; i < NG_PPP_MAX_LINKS; i++) {
if (newConf->links[i].enableLink && priv->links[i].hook != NULL)
newNumLinksActive++;
if (!newConf->links[i].enableLink)
continue;
if (newConf->links[i].mru < MP_MIN_LINK_MRU)
return (0);
if (newConf->links[i].bandwidth == 0)
return (0);
if (newConf->links[i].bandwidth > NG_PPP_MAX_BANDWIDTH)
return (0);
if (newConf->links[i].latency > NG_PPP_MAX_LATENCY)
return (0);
}
/* Disallow changes to multi-link configuration while MP is active */
if (priv->numActiveLinks > 0 && newNumLinksActive > 0) {
if (!priv->conf.enableMultilink
!= !newConf->bund.enableMultilink
|| !priv->conf.xmitShortSeq != !newConf->bund.xmitShortSeq
|| !priv->conf.recvShortSeq != !newConf->bund.recvShortSeq)
return (0);
}
/* At most one link can be active unless multi-link is enabled */
if (!newConf->bund.enableMultilink && newNumLinksActive > 1)
return (0);
/* Configuration change would be valid */
return (1);
}
/*
* Free all entries in the fragment queue
*/
static void
ng_ppp_frag_reset(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_frag *qent, *qnext;
for (qent = TAILQ_FIRST(&priv->frags); qent; qent = qnext) {
qnext = TAILQ_NEXT(qent, f_qent);
NG_FREE_M(qent->data);
TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
}
TAILQ_INIT(&priv->frags);
}
/*
* Start fragment queue timer
*/
static void
ng_ppp_start_frag_timer(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (!(callout_pending(&priv->fragTimer)))
ng_callout(&priv->fragTimer, node, NULL, MP_FRAGTIMER_INTERVAL,
ng_ppp_frag_timeout, NULL, 0);
}
/*
* Stop fragment queue timer
*/
static void
ng_ppp_stop_frag_timer(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (callout_pending(&priv->fragTimer))
ng_uncallout(&priv->fragTimer, node);
}
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