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freebsd/sys/netgraph/ng_ppp.c
Julian Elischer ed2836692f if you have taken the mbuf out of the message object, then if you pass 
the object to someone else, you need to put the mbuf back into it first..
2002-06-09 07:28:35 +00:00

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/*
* ng_ppp.c
*
* 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.
*
* Author: Archie Cobbs <archie@freebsd.org>
*
* $FreeBSD$
* $Whistle: ng_ppp.c,v 1.24 1999/11/01 09:24:52 julian Exp $
*/
/*
* PPP node type.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/errno.h>
#include <sys/ctype.h>
#include <machine/limits.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_APPLETALK 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_MIN_MRRU 1500 /* per RFC 1990 */
#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 smaller than this */
#define MP_MIN_FRAG_LEN 6
/* Maximum fragment reasssembly queue length */
#define MP_MAX_QUEUE_LEN 128
/* Fragment queue scanner period */
#define MP_FRAGTIMER_INTERVAL (hz/2)
/* We store incoming fragments this way */
struct ng_ppp_frag {
int seq; /* fragment seq# */
u_char first; /* First in packet? */
u_char last; /* Last in packet? */
struct timeval timestamp; /* time of reception */
struct mbuf *data; /* Fragment data */
meta_p meta; /* Fragment meta */
TAILQ_ENTRY(ng_ppp_frag) f_qent; /* Fragment queue */
};
/* We use integer indicies to refer to the non-link hooks */
static const char *const ng_ppp_hook_names[] = {
NG_PPP_HOOK_ATALK,
#define HOOK_INDEX_ATALK 0
NG_PPP_HOOK_BYPASS,
#define HOOK_INDEX_BYPASS 1
NG_PPP_HOOK_COMPRESS,
#define HOOK_INDEX_COMPRESS 2
NG_PPP_HOOK_ENCRYPT,
#define HOOK_INDEX_ENCRYPT 3
NG_PPP_HOOK_DECOMPRESS,
#define HOOK_INDEX_DECOMPRESS 4
NG_PPP_HOOK_DECRYPT,
#define HOOK_INDEX_DECRYPT 5
NG_PPP_HOOK_INET,
#define HOOK_INDEX_INET 6
NG_PPP_HOOK_IPX,
#define HOOK_INDEX_IPX 7
NG_PPP_HOOK_VJC_COMP,
#define HOOK_INDEX_VJC_COMP 8
NG_PPP_HOOK_VJC_IP,
#define HOOK_INDEX_VJC_IP 9
NG_PPP_HOOK_VJC_UNCOMP,
#define HOOK_INDEX_VJC_UNCOMP 10
NG_PPP_HOOK_VJC_VJIP,
#define HOOK_INDEX_VJC_VJIP 11
NG_PPP_HOOK_IPV6,
#define HOOK_INDEX_IPV6 12
NULL
#define HOOK_INDEX_MAX 13
};
/* We store index numbers in the hook private pointer. The HOOK_INDEX()
for a hook is either the index (above) for normal hooks, or the ones
complement of the link number for link hooks.
XXX Not any more.. (what a hack)
#define HOOK_INDEX(hook) (*((int16_t *) &(hook)->private))
*/
/* Per-link private information */
struct ng_ppp_link {
struct ng_ppp_link_conf conf; /* link configuration */
hook_p hook; /* connection to link data */
int32_t seq; /* highest rec'd seq# - MSEQ */
struct timeval lastWrite; /* time of last write */
int bytesInQueue; /* bytes in the output queue */
struct ng_ppp_link_stat stats; /* Link stats */
};
/* Total per-node private information */
struct ng_ppp_private {
struct ng_ppp_bund_conf conf; /* bundle config */
struct ng_ppp_link_stat 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 */
u_char vjCompHooked; /* VJ comp hooked up? */
u_char allLinksEqual; /* all xmit the same? */
u_char timerActive; /* frag timer active? */
u_int numActiveLinks; /* how many links up */
int activeLinks[NG_PPP_MAX_LINKS]; /* indicies */
u_int lastLink; /* for round robin */
hook_p hooks[HOOK_INDEX_MAX]; /* non-link hooks */
TAILQ_HEAD(ng_ppp_fraglist, ng_ppp_frag) /* fragment queue */
frags;
int qlen; /* fraq queue length */
struct callout_handle fragTimer; /* fraq queue check */
};
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;
/* Helper functions */
static int ng_ppp_input(node_p node, int bypass,
int linkNum, item_p item);
static int ng_ppp_output(node_p node, int bypass, int proto,
int linkNum, item_p item);
static int ng_ppp_mp_input(node_p node, int linkNum, item_p item);
static int ng_ppp_check_packet(node_p node);
static void ng_ppp_get_packet(node_p node, struct mbuf **mp, meta_p *metap);
static int ng_ppp_frag_process(node_p node);
static int ng_ppp_frag_trim(node_p node);
static void ng_ppp_frag_timeout(void *arg);
static void ng_ppp_frag_checkstale(node_p node);
static void ng_ppp_frag_reset(node_p node);
static int ng_ppp_mp_output(node_p node, struct mbuf *m, meta_p meta);
static void ng_ppp_mp_strategy(node_p node, int len, int *distrib);
static int ng_ppp_intcmp(const void *v1, const void *v2);
static struct mbuf *ng_ppp_addproto(struct mbuf *m, int proto, int compOK);
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
};
/* 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
},
{ 0 }
};
/* Node type descriptor */
static struct ng_type ng_ppp_typestruct = {
NG_ABI_VERSION,
NG_PPP_NODE_TYPE,
NULL,
ng_ppp_constructor,
ng_ppp_rcvmsg,
ng_ppp_shutdown,
ng_ppp_newhook,
NULL,
NULL,
ng_ppp_rcvdata,
ng_ppp_disconnect,
ng_ppp_cmds
};
NETGRAPH_INIT(ppp, &ng_ppp_typestruct);
static int *compareLatencies; /* hack for ng_ppp_intcmp() */
/* Address and control field header */
static const u_char 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 */
MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_PPP, M_NOWAIT | M_ZERO);
if (priv == NULL)
return (ENOMEM);
NG_NODE_SET_PRIVATE(node, priv);
/* Initialize state */
TAILQ_INIT(&priv->frags);
for (i = 0; i < NG_PPP_MAX_LINKS; i++)
priv->links[i].seq = MP_NOSEQ;
callout_handle_init(&priv->fragTimer);
/* 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);
int linkNum = -1;
hook_p *hookPtr = NULL;
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;
} else { /* must be a non-link hook */
int i;
for (i = 0; ng_ppp_hook_names[i] != NULL; i++) {
if (strcmp(name, ng_ppp_hook_names[i]) == 0) {
hookPtr = &priv->hooks[i];
hookIndex = i;
break;
}
}
if (ng_ppp_hook_names[i] == NULL)
return (EINVAL); /* no such hook */
}
/* See if hook is already connected */
if (*hookPtr != NULL)
return (EISCONN);
/* Disallow more than one link unless multilink is enabled */
if (linkNum != -1 && priv->links[linkNum].conf.enableLink
&& !priv->conf.enableMultilink && priv->numActiveLinks >= 1)
return (ENODEV);
/* OK */
*hookPtr = hook;
NG_HOOK_SET_PRIVATE(hook, (void *)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:
{
struct ng_ppp_link_stat *stats;
u_int16_t linkNum;
if (msg->header.arglen != sizeof(u_int16_t))
ERROUT(EINVAL);
linkNum = *((u_int16_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;
if (msg->header.cmd != NGM_PPP_CLR_LINK_STATS) {
NG_MKRESPONSE(resp, msg,
sizeof(struct ng_ppp_link_stat), M_NOWAIT);
if (resp == NULL)
ERROUT(ENOMEM);
bcopy(stats, resp->data, sizeof(*stats));
}
if (msg->header.cmd != NGM_PPP_GET_LINK_STATS)
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->links[HOOK_INDEX_VJC_IP].hook)) {
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);
}
/*
* Receive data on a hook
*/
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 = (int)NG_HOOK_PRIVATE(hook);
u_int16_t linkNum = NG_PPP_BUNDLE_LINKNUM;
hook_p outHook = NULL;
int proto = 0, error;
struct mbuf *m;
NGI_GET_M(item, m);
/* Did it come from a link hook? */
if (index < 0) {
struct ng_ppp_link *link;
/* Convert index into a link number */
linkNum = (u_int16_t)~index;
KASSERT(linkNum < NG_PPP_MAX_LINKS,
("%s: bogus index 0x%x", __func__, index));
link = &priv->links[linkNum];
/* Stats */
link->stats.recvFrames++;
link->stats.recvOctets += m->m_pkthdr.len;
/* Strip address and control fields, if present */
if (m->m_pkthdr.len >= 2) {
if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
if (bcmp(mtod(m, u_char *), &ng_ppp_acf, 2) == 0)
m_adj(m, 2);
}
/* Dispatch incoming frame (if not enabled, to bypass) */
NGI_M(item) = m; /* put changed m back in item */
return ng_ppp_input(node,
!link->conf.enableLink, linkNum, item);
}
/* Get protocol & check if data allowed from this hook */
NGI_M(item) = m; /* put possibly changed m back in item */
switch (index) {
/* Outgoing data */
case HOOK_INDEX_ATALK:
if (!priv->conf.enableAtalk) {
NG_FREE_ITEM(item);
return (ENXIO);
}
proto = PROT_APPLETALK;
break;
case HOOK_INDEX_IPX:
if (!priv->conf.enableIPX) {
NG_FREE_ITEM(item);
return (ENXIO);
}
proto = PROT_IPX;
break;
case HOOK_INDEX_IPV6:
if (!priv->conf.enableIPv6) {
NG_FREE_ITEM(item);
return (ENXIO);
}
proto = PROT_IPV6;
break;
case HOOK_INDEX_INET:
case HOOK_INDEX_VJC_VJIP:
if (!priv->conf.enableIP) {
NG_FREE_ITEM(item);
return (ENXIO);
}
proto = PROT_IP;
break;
case HOOK_INDEX_VJC_COMP:
if (!priv->conf.enableVJCompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
proto = PROT_VJCOMP;
break;
case HOOK_INDEX_VJC_UNCOMP:
if (!priv->conf.enableVJCompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
proto = PROT_VJUNCOMP;
break;
case HOOK_INDEX_COMPRESS:
if (!priv->conf.enableCompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
proto = PROT_COMPD;
break;
case HOOK_INDEX_ENCRYPT:
if (!priv->conf.enableEncryption) {
NG_FREE_ITEM(item);
return (ENXIO);
}
proto = PROT_CRYPTD;
break;
case HOOK_INDEX_BYPASS:
if (m->m_pkthdr.len < 4) {
NG_FREE_ITEM(item);
return (EINVAL);
}
if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
NGI_M(item) = NULL; /* don't free twice */
NG_FREE_ITEM(item);
return (ENOBUFS);
}
NGI_M(item) = m; /* m may have changed */
linkNum = ntohs(mtod(m, u_int16_t *)[0]);
proto = ntohs(mtod(m, u_int16_t *)[1]);
m_adj(m, 4);
if (linkNum >= NG_PPP_MAX_LINKS
&& linkNum != NG_PPP_BUNDLE_LINKNUM) {
NG_FREE_ITEM(item);
return (EINVAL);
}
break;
/* Incoming data */
case HOOK_INDEX_VJC_IP:
if (!priv->conf.enableIP || !priv->conf.enableVJDecompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
break;
case HOOK_INDEX_DECOMPRESS:
if (!priv->conf.enableDecompression) {
NG_FREE_ITEM(item);
return (ENXIO);
}
break;
case HOOK_INDEX_DECRYPT:
if (!priv->conf.enableDecryption) {
NG_FREE_ITEM(item);
return (ENXIO);
}
break;
default:
panic("%s: bogus index 0x%x", __func__, index);
}
/* Now figure out what to do with the frame */
switch (index) {
/* Outgoing data */
case HOOK_INDEX_INET:
if (priv->conf.enableVJCompression && priv->vjCompHooked) {
outHook = priv->hooks[HOOK_INDEX_VJC_IP];
break;
}
/* FALLTHROUGH */
case HOOK_INDEX_ATALK:
case HOOK_INDEX_IPV6:
case HOOK_INDEX_IPX:
case HOOK_INDEX_VJC_COMP:
case HOOK_INDEX_VJC_UNCOMP:
case HOOK_INDEX_VJC_VJIP:
if (priv->conf.enableCompression
&& priv->hooks[HOOK_INDEX_COMPRESS] != NULL) {
if ((m = ng_ppp_addproto(m, proto, 1)) == NULL) {
NGI_M(item) = NULL;
NG_FREE_ITEM(item);
return (ENOBUFS);
}
NGI_M(item) = m; /* m may have changed */
outHook = priv->hooks[HOOK_INDEX_COMPRESS];
break;
}
/* FALLTHROUGH */
case HOOK_INDEX_COMPRESS:
if (priv->conf.enableEncryption
&& priv->hooks[HOOK_INDEX_ENCRYPT] != NULL) {
if ((m = ng_ppp_addproto(m, proto, 1)) == NULL) {
NGI_M(item) = NULL;
NG_FREE_ITEM(item);
return (ENOBUFS);
}
NGI_M(item) = m; /* m may have changed */
outHook = priv->hooks[HOOK_INDEX_ENCRYPT];
break;
}
/* FALLTHROUGH */
case HOOK_INDEX_ENCRYPT:
return ng_ppp_output(node, 0, proto, NG_PPP_BUNDLE_LINKNUM, item);
case HOOK_INDEX_BYPASS:
return ng_ppp_output(node, 1, proto, linkNum, item);
/* Incoming data */
case HOOK_INDEX_DECRYPT:
case HOOK_INDEX_DECOMPRESS:
return ng_ppp_input(node, 0, NG_PPP_BUNDLE_LINKNUM, item);
case HOOK_INDEX_VJC_IP:
outHook = priv->hooks[HOOK_INDEX_INET];
break;
}
/* Send packet out hook */
NG_FWD_ITEM_HOOK(error, item, outHook);
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);
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 = (int)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);
}
/************************************************************************
HELPER STUFF
************************************************************************/
/*
* Handle an incoming frame. Extract the PPP protocol number
* and dispatch accordingly.
*/
static int
ng_ppp_input(node_p node, int bypass, int linkNum, item_p item)
{
const priv_p priv = NG_NODE_PRIVATE(node);
hook_p outHook = NULL;
int proto, error;
struct mbuf *m;
NGI_GET_M(item, m);
/* Extract protocol number */
for (proto = 0; !PROT_VALID(proto) && m->m_pkthdr.len > 0; ) {
if (m->m_len < 1 && (m = m_pullup(m, 1)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
proto = (proto << 8) + *mtod(m, u_char *);
m_adj(m, 1);
}
if (!PROT_VALID(proto)) {
if (linkNum == NG_PPP_BUNDLE_LINKNUM)
priv->bundleStats.badProtos++;
else
priv->links[linkNum].stats.badProtos++;
NG_FREE_ITEM(item);
NG_FREE_M(m);
return (EINVAL);
}
/* Bypass frame? */
if (bypass)
goto bypass;
/* Check protocol */
switch (proto) {
case PROT_COMPD:
if (priv->conf.enableDecompression)
outHook = priv->hooks[HOOK_INDEX_DECOMPRESS];
break;
case PROT_CRYPTD:
if (priv->conf.enableDecryption)
outHook = priv->hooks[HOOK_INDEX_DECRYPT];
break;
case PROT_VJCOMP:
if (priv->conf.enableVJDecompression && priv->vjCompHooked)
outHook = priv->hooks[HOOK_INDEX_VJC_COMP];
break;
case PROT_VJUNCOMP:
if (priv->conf.enableVJDecompression && priv->vjCompHooked)
outHook = priv->hooks[HOOK_INDEX_VJC_UNCOMP];
break;
case PROT_MP:
if (priv->conf.enableMultilink
&& linkNum != NG_PPP_BUNDLE_LINKNUM) {
NGI_M(item) = m;
return ng_ppp_mp_input(node, linkNum, item);
}
break;
case PROT_APPLETALK:
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;
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;
}
bypass:
/* For unknown/inactive protocols, forward out the bypass hook */
if (outHook == NULL) {
u_int16_t hdr[2];
hdr[0] = htons(linkNum);
hdr[1] = htons((u_int16_t)proto);
if ((m = ng_ppp_prepend(m, &hdr, 4)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
outHook = priv->hooks[HOOK_INDEX_BYPASS];
}
/* Forward frame */
NG_FWD_NEW_DATA(error, item, outHook, m);
return (error);
}
/*
* Deliver a frame out a link, either a real one or NG_PPP_BUNDLE_LINKNUM.
* If the link is not enabled then ENXIO is returned, unless "bypass" is != 0.
*
* If the frame is too big for the particular link, return EMSGSIZE.
*/
static int
ng_ppp_output(node_p node, int bypass,
int proto, int linkNum, item_p item)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_link *link;
int len, error;
struct mbuf *m;
u_int16_t mru;
/* Extract mbuf */
NGI_GET_M(item, m);
/* If not doing MP, map bundle virtual link to (the only) link */
if (linkNum == NG_PPP_BUNDLE_LINKNUM && !priv->conf.enableMultilink)
linkNum = priv->activeLinks[0];
/* Get link pointer (optimization) */
link = (linkNum != NG_PPP_BUNDLE_LINKNUM) ?
&priv->links[linkNum] : NULL;
/* Check link status (if real) */
if (linkNum != NG_PPP_BUNDLE_LINKNUM) {
if (!bypass && !link->conf.enableLink) {
NG_FREE_M(m);
NG_FREE_ITEM(item);
return (ENXIO);
}
if (link->hook == NULL) {
NG_FREE_M(m);
NG_FREE_ITEM(item);
return (ENETDOWN);
}
}
/* Check peer's MRU for this link */
mru = (link != NULL) ? link->conf.mru : priv->conf.mrru;
if (mru != 0 && m->m_pkthdr.len > mru) {
NG_FREE_M(m);
NG_FREE_ITEM(item);
return (EMSGSIZE);
}
/* Prepend protocol number, possibly compressed */
if ((m = ng_ppp_addproto(m, proto,
linkNum == NG_PPP_BUNDLE_LINKNUM
|| link->conf.enableProtoComp)) == NULL) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
/* Special handling for the MP virtual link */
if (linkNum == NG_PPP_BUNDLE_LINKNUM) {
meta_p meta;
/* strip off and discard the queue item */
NGI_GET_META(item, meta);
NG_FREE_ITEM(item);
return ng_ppp_mp_output(node, m, meta);
}
/* 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) {
NG_FREE_ITEM(item);
return (ENOBUFS);
}
}
/* Deliver frame */
len = m->m_pkthdr.len;
NG_FWD_NEW_DATA(error, item, link->hook, m);
/* Update stats and 'bytes in queue' counter */
if (error == 0) {
link->stats.xmitFrames++;
link->stats.xmitOctets += len;
link->bytesInQueue += len;
getmicrouptime(&link->lastWrite);
}
return error;
}
/*
* 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_input(node_p node, int linkNum, item_p item)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_ppp_link *const link = &priv->links[linkNum];
struct ng_ppp_frag frag0, *frag = &frag0;
struct ng_ppp_frag *qent;
int i, diff, inserted;
struct mbuf *m;
meta_p meta;
NGI_GET_M(item, m);
NGI_GET_META(item, meta);
NG_FREE_ITEM(item);
/* Stats */
priv->bundleStats.recvFrames++;
priv->bundleStats.recvOctets += m->m_pkthdr.len;
/* Extract fragment information from MP header */
if (priv->conf.recvShortSeq) {
u_int16_t shdr;
if (m->m_pkthdr.len < 2) {
link->stats.runts++;
NG_FREE_M(m);
NG_FREE_META(meta);
return (EINVAL);
}
if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
NG_FREE_META(meta);
return (ENOBUFS);
}
shdr = ntohs(*mtod(m, u_int16_t *));
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 {
u_int32_t lhdr;
if (m->m_pkthdr.len < 4) {
link->stats.runts++;
NG_FREE_M(m);
NG_FREE_META(meta);
return (EINVAL);
}
if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
NG_FREE_META(meta);
return (ENOBUFS);
}
lhdr = ntohl(*mtod(m, u_int32_t *));
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;
frag->meta = meta;
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);
NG_FREE_META(meta);
return (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;
}
/* Allocate a new frag struct for the queue */
MALLOC(frag, struct ng_ppp_frag *, sizeof(*frag), M_NETGRAPH_PPP, M_NOWAIT);
if (frag == NULL) {
NG_FREE_M(m);
NG_FREE_META(meta);
ng_ppp_frag_process(node);
return (ENOMEM);
}
*frag = frag0;
/* 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);
NG_FREE_META(frag->meta);
FREE(frag, M_NETGRAPH_PPP);
return (EINVAL);
}
}
if (!inserted)
TAILQ_INSERT_HEAD(&priv->frags, frag, f_qent);
priv->qlen++;
/* Process the queue */
return ng_ppp_frag_process(node);
}
/*
* 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, meta_p *metap)
{
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;
*metap = qent->meta; /* inherit first frag's meta */
} else {
m->m_pkthdr.len += qent->data->m_pkthdr.len;
tail->m_next = qent->data;
NG_FREE_META(qent->meta); /* drop other frags' metas */
}
while (tail->m_next != NULL)
tail = tail->m_next;
if (qent->last)
qnext = NULL;
FREE(qent, M_NETGRAPH_PPP);
priv->qlen--;
}
*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);
NG_FREE_META(qent->meta);
FREE(qent, M_NETGRAPH_PPP);
priv->qlen--;
removed = 1;
}
}
return (removed);
}
/*
* Run the queue, restoring the queue invariants
*/
static int
ng_ppp_frag_process(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct mbuf *m;
meta_p meta;
item_p item;
/* Deliver any deliverable packets */
while (ng_ppp_check_packet(node)) {
ng_ppp_get_packet(node, &m, &meta);
item = ng_package_data(m, meta);
ng_ppp_input(node, 0, NG_PPP_BUNDLE_LINKNUM, item);
}
/* Delete dead fragments and try again */
if (ng_ppp_frag_trim(node)) {
while (ng_ppp_check_packet(node)) {
ng_ppp_get_packet(node, &m, &meta);
item = ng_package_data(m, meta);
ng_ppp_input(node, 0, NG_PPP_BUNDLE_LINKNUM, item);
}
}
/* Check for stale fragments while we're here */
ng_ppp_frag_checkstale(node);
/* Check queue length */
if (priv->qlen > MP_MAX_QUEUE_LEN) {
struct ng_ppp_frag *qent;
int i;
/* Get oldest fragment */
KASSERT(!TAILQ_EMPTY(&priv->frags),
("%s: empty q", __func__));
qent = TAILQ_FIRST(&priv->frags);
/* Bump MSEQ if necessary */
if (MP_RECV_SEQ_DIFF(priv, priv->mseq, qent->seq) < 0) {
priv->mseq = qent->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)
alink->seq = priv->mseq;
}
}
/* Drop it */
priv->bundleStats.dropFragments++;
TAILQ_REMOVE(&priv->frags, qent, f_qent);
NG_FREE_M(qent->data);
NG_FREE_META(qent->meta);
FREE(qent, M_NETGRAPH_PPP);
priv->qlen--;
/* Process queue again */
return ng_ppp_frag_process(node);
}
/* 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;
meta_p meta;
int i, seq;
item_p item;
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);
NG_FREE_META(qent->meta);
FREE(qent, M_NETGRAPH_PPP);
priv->qlen--;
}
/* Extract completed packet */
ng_ppp_get_packet(node, &m, &meta);
/* Bump MSEQ if necessary */
if (MP_RECV_SEQ_DIFF(priv, priv->mseq, end->seq) < 0) {
priv->mseq = end->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)
alink->seq = priv->mseq;
}
}
/* Deliver packet */
item = ng_package_data(m, meta);
ng_ppp_input(node, 0, NG_PPP_BUNDLE_LINKNUM, item);
}
}
/*
* Periodically call ng_ppp_frag_checkstale()
*/
static void
ng_ppp_frag_timeout(void *arg)
{
const node_p node = arg;
const priv_p priv = NG_NODE_PRIVATE(node);
int s = splnet();
/* Handle the race where shutdown happens just before splnet() above */
if (NG_NODE_NOT_VALID(node)) {
NG_NODE_UNREF(node);
splx(s);
return;
}
/* Reset timer state after timeout */
KASSERT(priv->timerActive, ("%s: !timerActive", __func__));
priv->timerActive = 0;
KASSERT(node->nd_refs > 1, ("%s: nd_refs=%d", __func__, node->nd_refs));
NG_NODE_UNREF(node);
/* Start timer again */
ng_ppp_start_frag_timer(node);
/* Scan the fragment queue */
ng_ppp_frag_checkstale(node);
splx(s);
}
/*
* 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_output(node_p node, struct mbuf *m, meta_p meta)
{
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;
item_p item;
/* At least one link must be active */
if (priv->numActiveLinks == 0) {
NG_FREE_M(m);
NG_FREE_META(meta);
return (ENETDOWN);
}
/* Round-robin strategy */
if (priv->conf.enableRoundRobin || m->m_pkthdr.len < MP_MIN_FRAG_LEN) {
activeLinkNum = priv->lastLink++ % priv->numActiveLinks;
bzero(&distrib, priv->numActiveLinks * sizeof(distrib[0]));
distrib[activeLinkNum] = m->m_pkthdr.len;
goto deliver;
}
/* Strategy when all links are equivalent (optimize the common case) */
if (priv->allLinksEqual) {
const int fraction = m->m_pkthdr.len / priv->numActiveLinks;
int i, remain;
for (i = 0; i < priv->numActiveLinks; i++)
distrib[priv->lastLink++ % priv->numActiveLinks]
= fraction;
remain = m->m_pkthdr.len - (fraction * priv->numActiveLinks);
while (remain > 0) {
distrib[priv->lastLink++ % priv->numActiveLinks]++;
remain--;
}
goto deliver;
}
/* Strategy when all links are not equivalent */
ng_ppp_mp_strategy(node, m->m_pkthdr.len, distrib);
deliver:
/* Update stats */
priv->bundleStats.xmitFrames++;
priv->bundleStats.xmitOctets += m->m_pkthdr.len;
/* Send alloted portions of frame out on the link(s) */
for (firstFragment = 1, activeLinkNum = priv->numActiveLinks - 1;
activeLinkNum >= 0; activeLinkNum--) {
const int 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;
meta_p meta2;
/* 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_NOWAIT);
if (n == NULL) {
NG_FREE_M(m);
NG_FREE_META(meta);
return (ENOMEM);
}
m = n;
}
/* Prepend MP header */
if (priv->conf.xmitShortSeq) {
u_int16_t shdr;
shdr = priv->xseq;
priv->xseq =
(priv->xseq + 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 {
u_int32_t lhdr;
lhdr = priv->xseq;
priv->xseq =
(priv->xseq + 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);
NG_FREE_META(meta);
return (ENOBUFS);
}
/* Copy the meta information, if any */
meta2 = lastFragment ? meta : ng_copy_meta(meta);
/* Send fragment */
item = ng_package_data(m2, meta2);
error = ng_ppp_output(node, 0, PROT_MP, linkNum, item);
if (error != 0) {
if (!lastFragment) {
NG_FREE_M(m);
NG_FREE_META(meta);
}
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->conf.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);
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 * 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 */
compareLatencies = latency;
qsort(sortByLatency,
priv->numActiveLinks, sizeof(*sortByLatency), ng_ppp_intcmp);
compareLatencies = NULL;
/* 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 */
bzero(distrib, priv->numActiveLinks * sizeof(*distrib));
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(const void *v1, const void *v2)
{
const int index1 = *((const int *) v1);
const int index2 = *((const int *) v2);
return compareLatencies[index1] - compareLatencies[index2];
}
/*
* Prepend a possibly compressed PPP protocol number in front of a frame
*/
static struct mbuf *
ng_ppp_addproto(struct mbuf *m, int proto, int compOK)
{
if (compOK && PROT_COMPRESSABLE(proto)) {
u_char pbyte = (u_char)proto;
return ng_ppp_prepend(m, &pbyte, 1);
} else {
u_int16_t pword = htons((u_int16_t)proto);
return ng_ppp_prepend(m, &pword, 2);
}
}
/*
* 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_NOWAIT);
if (m == NULL || (m->m_len < len && (m = m_pullup(m, len)) == NULL))
return (NULL);
bcopy(buf, mtod(m, u_char *), 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;
hdrBytes = (priv->links[i].conf.enableACFComp ? 0 : 2)
+ (priv->links[i].conf.enableProtoComp ? 1 : 2)
+ (priv->conf.xmitShortSeq ? 2 : 4);
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->conf.latency != link0->conf.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);
}
/* Check bundle parameters */
if (newConf->bund.enableMultilink && newConf->bund.mrru < MP_MIN_MRRU)
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);
NG_FREE_META(qent->meta);
FREE(qent, M_NETGRAPH_PPP);
}
TAILQ_INIT(&priv->frags);
priv->qlen = 0;
}
/*
* Start fragment queue timer
*/
static void
ng_ppp_start_frag_timer(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (!priv->timerActive) {
priv->fragTimer = timeout(ng_ppp_frag_timeout,
node, MP_FRAGTIMER_INTERVAL);
priv->timerActive = 1;
NG_NODE_REF(node);
}
}
/*
* Stop fragment queue timer
*/
static void
ng_ppp_stop_frag_timer(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (priv->timerActive) {
untimeout(ng_ppp_frag_timeout, node, priv->fragTimer);
priv->timerActive = 0;
KASSERT(node->nd_refs > 1,
("%s: nd_refs=%d", __func__, node->nd_refs));
NG_NODE_UNREF(node);
}
}
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