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freebsd/sys/netgraph/ng_async.c
Warner Losh c398230b64 /* -> /*- for license, minor formatting changes
2005-01-07 01:45:51 +00:00

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/*
* ng_async.c
*/
/*-
* Copyright (c) 1996-1999 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_async.c,v 1.17 1999/11/01 09:24:51 julian Exp $
*/
/*
* This node type implements a PPP style sync <-> async converter.
* See RFC 1661 for details of how asynchronous encoding works.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/errno.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_async.h>
#include <netgraph/ng_parse.h>
#include <net/ppp_defs.h>
#ifdef NG_SEPARATE_MALLOC
MALLOC_DEFINE(M_NETGRAPH_ASYNC, "netgraph_async", "netgraph async node ");
#else
#define M_NETGRAPH_ASYNC M_NETGRAPH
#endif
/* Async decode state */
#define MODE_HUNT 0
#define MODE_NORMAL 1
#define MODE_ESC 2
/* Private data structure */
struct ng_async_private {
node_p node; /* Our node */
hook_p async; /* Asynchronous side */
hook_p sync; /* Synchronous side */
u_char amode; /* Async hunt/esape mode */
u_int16_t fcs; /* Decoded async FCS (so far) */
u_char *abuf; /* Buffer to encode sync into */
u_char *sbuf; /* Buffer to decode async into */
u_int slen; /* Length of data in sbuf */
long lasttime; /* Time of last async packet sent */
struct ng_async_cfg cfg; /* Configuration */
struct ng_async_stat stats; /* Statistics */
};
typedef struct ng_async_private *sc_p;
/* Useful macros */
#define ASYNC_BUF_SIZE(smru) (2 * (smru) + 10)
#define SYNC_BUF_SIZE(amru) ((amru) + 10)
#define ERROUT(x) do { error = (x); goto done; } while (0)
/* Netgraph methods */
static ng_constructor_t nga_constructor;
static ng_rcvdata_t nga_rcvdata;
static ng_rcvmsg_t nga_rcvmsg;
static ng_shutdown_t nga_shutdown;
static ng_newhook_t nga_newhook;
static ng_disconnect_t nga_disconnect;
/* Helper stuff */
static int nga_rcv_sync(const sc_p sc, item_p item);
static int nga_rcv_async(const sc_p sc, item_p item);
/* Parse type for struct ng_async_cfg */
static const struct ng_parse_struct_field nga_config_type_fields[]
= NG_ASYNC_CONFIG_TYPE_INFO;
static const struct ng_parse_type nga_config_type = {
&ng_parse_struct_type,
&nga_config_type_fields
};
/* Parse type for struct ng_async_stat */
static const struct ng_parse_struct_field nga_stats_type_fields[]
= NG_ASYNC_STATS_TYPE_INFO;
static const struct ng_parse_type nga_stats_type = {
&ng_parse_struct_type,
&nga_stats_type_fields
};
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist nga_cmdlist[] = {
{
NGM_ASYNC_COOKIE,
NGM_ASYNC_CMD_SET_CONFIG,
"setconfig",
&nga_config_type,
NULL
},
{
NGM_ASYNC_COOKIE,
NGM_ASYNC_CMD_GET_CONFIG,
"getconfig",
NULL,
&nga_config_type
},
{
NGM_ASYNC_COOKIE,
NGM_ASYNC_CMD_GET_STATS,
"getstats",
NULL,
&nga_stats_type
},
{
NGM_ASYNC_COOKIE,
NGM_ASYNC_CMD_CLR_STATS,
"clrstats",
&nga_stats_type,
NULL
},
{ 0 }
};
/* Define the netgraph node type */
static struct ng_type typestruct = {
.version = NG_ABI_VERSION,
.name = NG_ASYNC_NODE_TYPE,
.constructor = nga_constructor,
.rcvmsg = nga_rcvmsg,
.shutdown = nga_shutdown,
.newhook = nga_newhook,
.rcvdata = nga_rcvdata,
.disconnect = nga_disconnect,
.cmdlist = nga_cmdlist
};
NETGRAPH_INIT(async, &typestruct);
/* CRC table */
static const u_int16_t fcstab[];
/******************************************************************
NETGRAPH NODE METHODS
******************************************************************/
/*
* Initialize a new node
*/
static int
nga_constructor(node_p node)
{
sc_p sc;
MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH_ASYNC, M_NOWAIT | M_ZERO);
if (sc == NULL)
return (ENOMEM);
sc->amode = MODE_HUNT;
sc->cfg.accm = ~0;
sc->cfg.amru = NG_ASYNC_DEFAULT_MRU;
sc->cfg.smru = NG_ASYNC_DEFAULT_MRU;
MALLOC(sc->abuf, u_char *,
ASYNC_BUF_SIZE(sc->cfg.smru), M_NETGRAPH_ASYNC, M_NOWAIT);
if (sc->abuf == NULL)
goto fail;
MALLOC(sc->sbuf, u_char *,
SYNC_BUF_SIZE(sc->cfg.amru), M_NETGRAPH_ASYNC, M_NOWAIT);
if (sc->sbuf == NULL) {
FREE(sc->abuf, M_NETGRAPH_ASYNC);
fail:
FREE(sc, M_NETGRAPH_ASYNC);
return (ENOMEM);
}
NG_NODE_SET_PRIVATE(node, sc);
sc->node = node;
return (0);
}
/*
* Reserve a hook for a pending connection
*/
static int
nga_newhook(node_p node, hook_p hook, const char *name)
{
const sc_p sc = NG_NODE_PRIVATE(node);
hook_p *hookp;
if (!strcmp(name, NG_ASYNC_HOOK_ASYNC)) {
/*
* We use a static buffer here so only one packet
* at a time can be allowed to travel in this direction.
* Force Writer semantics.
*/
NG_HOOK_FORCE_WRITER(hook);
hookp = &sc->async;
} else if (!strcmp(name, NG_ASYNC_HOOK_SYNC)) {
/*
* We use a static state here so only one packet
* at a time can be allowed to travel in this direction.
* Force Writer semantics.
* Since we set this for both directions
* we might as well set it for the whole node
* bit I haven;t done that (yet).
*/
NG_HOOK_FORCE_WRITER(hook);
hookp = &sc->sync;
} else {
return (EINVAL);
}
if (*hookp) /* actually can't happen I think [JRE] */
return (EISCONN);
*hookp = hook;
return (0);
}
/*
* Receive incoming data
*/
static int
nga_rcvdata(hook_p hook, item_p item)
{
const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
if (hook == sc->sync)
return (nga_rcv_sync(sc, item));
if (hook == sc->async)
return (nga_rcv_async(sc, item));
panic(__func__);
}
/*
* Receive incoming control message
*/
static int
nga_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
const sc_p sc = 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_ASYNC_COOKIE:
switch (msg->header.cmd) {
case NGM_ASYNC_CMD_GET_STATS:
NG_MKRESPONSE(resp, msg, sizeof(sc->stats), M_NOWAIT);
if (resp == NULL)
ERROUT(ENOMEM);
*((struct ng_async_stat *) resp->data) = sc->stats;
break;
case NGM_ASYNC_CMD_CLR_STATS:
bzero(&sc->stats, sizeof(sc->stats));
break;
case NGM_ASYNC_CMD_SET_CONFIG:
{
struct ng_async_cfg *const cfg =
(struct ng_async_cfg *) msg->data;
u_char *buf;
if (msg->header.arglen != sizeof(*cfg))
ERROUT(EINVAL);
if (cfg->amru < NG_ASYNC_MIN_MRU
|| cfg->amru > NG_ASYNC_MAX_MRU
|| cfg->smru < NG_ASYNC_MIN_MRU
|| cfg->smru > NG_ASYNC_MAX_MRU)
ERROUT(EINVAL);
cfg->enabled = !!cfg->enabled; /* normalize */
if (cfg->smru > sc->cfg.smru) { /* reallocate buffer */
MALLOC(buf, u_char *, ASYNC_BUF_SIZE(cfg->smru),
M_NETGRAPH_ASYNC, M_NOWAIT);
if (!buf)
ERROUT(ENOMEM);
FREE(sc->abuf, M_NETGRAPH_ASYNC);
sc->abuf = buf;
}
if (cfg->amru > sc->cfg.amru) { /* reallocate buffer */
MALLOC(buf, u_char *, SYNC_BUF_SIZE(cfg->amru),
M_NETGRAPH_ASYNC, M_NOWAIT);
if (!buf)
ERROUT(ENOMEM);
FREE(sc->sbuf, M_NETGRAPH_ASYNC);
sc->sbuf = buf;
sc->amode = MODE_HUNT;
sc->slen = 0;
}
if (!cfg->enabled) {
sc->amode = MODE_HUNT;
sc->slen = 0;
}
sc->cfg = *cfg;
break;
}
case NGM_ASYNC_CMD_GET_CONFIG:
NG_MKRESPONSE(resp, msg, sizeof(sc->cfg), M_NOWAIT);
if (!resp)
ERROUT(ENOMEM);
*((struct ng_async_cfg *) resp->data) = sc->cfg;
break;
default:
ERROUT(EINVAL);
}
break;
default:
ERROUT(EINVAL);
}
done:
NG_RESPOND_MSG(error, node, item, resp);
NG_FREE_MSG(msg);
return (error);
}
/*
* Shutdown this node
*/
static int
nga_shutdown(node_p node)
{
const sc_p sc = NG_NODE_PRIVATE(node);
FREE(sc->abuf, M_NETGRAPH_ASYNC);
FREE(sc->sbuf, M_NETGRAPH_ASYNC);
bzero(sc, sizeof(*sc));
FREE(sc, M_NETGRAPH_ASYNC);
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node);
return (0);
}
/*
* Lose a hook. When both hooks go away, we disappear.
*/
static int
nga_disconnect(hook_p hook)
{
const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
hook_p *hookp;
if (hook == sc->async)
hookp = &sc->async;
else if (hook == sc->sync)
hookp = &sc->sync;
else
panic(__func__);
if (!*hookp)
panic("%s 2", __func__);
*hookp = NULL;
bzero(&sc->stats, sizeof(sc->stats));
sc->lasttime = 0;
if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
ng_rmnode_self(NG_HOOK_NODE(hook));
return (0);
}
/******************************************************************
INTERNAL HELPER STUFF
******************************************************************/
/*
* Encode a byte into the async buffer
*/
static __inline void
nga_async_add(const sc_p sc, u_int16_t *fcs, u_int32_t accm, int *len, u_char x)
{
*fcs = PPP_FCS(*fcs, x);
if ((x < 32 && ((1 << x) & accm))
|| (x == PPP_ESCAPE)
|| (x == PPP_FLAG)) {
sc->abuf[(*len)++] = PPP_ESCAPE;
x ^= PPP_TRANS;
}
sc->abuf[(*len)++] = x;
}
/*
* Receive incoming synchronous data.
*/
static int
nga_rcv_sync(const sc_p sc, item_p item)
{
struct ifnet *rcvif;
int alen, error = 0;
struct timeval time;
u_int16_t fcs, fcs0;
u_int32_t accm;
struct mbuf *m;
#define ADD_BYTE(x) nga_async_add(sc, &fcs, accm, &alen, (x))
/* Check for bypass mode */
if (!sc->cfg.enabled) {
NG_FWD_ITEM_HOOK(error, item, sc->async );
return (error);
}
NGI_GET_M(item, m);
rcvif = m->m_pkthdr.rcvif;
/* Get ACCM; special case LCP frames, which use full ACCM */
accm = sc->cfg.accm;
if (m->m_pkthdr.len >= 4) {
static const u_char lcphdr[4] = {
PPP_ALLSTATIONS,
PPP_UI,
(u_char)(PPP_LCP >> 8),
(u_char)(PPP_LCP & 0xff)
};
u_char buf[4];
m_copydata(m, 0, 4, (caddr_t)buf);
if (bcmp(buf, &lcphdr, 4) == 0)
accm = ~0;
}
/* Check for overflow */
if (m->m_pkthdr.len > sc->cfg.smru) {
sc->stats.syncOverflows++;
NG_FREE_M(m);
NG_FREE_ITEM(item);
return (EMSGSIZE);
}
/* Update stats */
sc->stats.syncFrames++;
sc->stats.syncOctets += m->m_pkthdr.len;
/* Initialize async encoded version of input mbuf */
alen = 0;
fcs = PPP_INITFCS;
/* Add beginning sync flag if it's been long enough to need one */
getmicrotime(&time);
if (time.tv_sec >= sc->lasttime + 1) {
sc->abuf[alen++] = PPP_FLAG;
sc->lasttime = time.tv_sec;
}
/* Add packet payload */
while (m != NULL) {
while (m->m_len > 0) {
ADD_BYTE(*mtod(m, u_char *));
m->m_data++;
m->m_len--;
}
m = m_free(m);
}
/* Add checksum and final sync flag */
fcs0 = fcs;
ADD_BYTE(~fcs0 & 0xff);
ADD_BYTE(~fcs0 >> 8);
sc->abuf[alen++] = PPP_FLAG;
/* Put frame in an mbuf and ship it off */
if (!(m = m_devget(sc->abuf, alen, 0, rcvif, NULL))) {
NG_FREE_ITEM(item);
error = ENOBUFS;
} else {
NG_FWD_NEW_DATA(error, item, sc->async, m);
}
return (error);
}
/*
* Receive incoming asynchronous data
* XXX Technically, we should strip out incoming characters
* that are in our ACCM. Not sure if this is good or not.
*/
static int
nga_rcv_async(const sc_p sc, item_p item)
{
struct ifnet *rcvif;
int error;
struct mbuf *m;
if (!sc->cfg.enabled) {
NG_FWD_ITEM_HOOK(error, item, sc->sync);
return (error);
}
NGI_GET_M(item, m);
rcvif = m->m_pkthdr.rcvif;
while (m) {
struct mbuf *n;
for (; m->m_len > 0; m->m_data++, m->m_len--) {
u_char ch = *mtod(m, u_char *);
sc->stats.asyncOctets++;
if (ch == PPP_FLAG) { /* Flag overrides everything */
int skip = 0;
/* Check for runts */
if (sc->slen < 2) {
if (sc->slen > 0)
sc->stats.asyncRunts++;
goto reset;
}
/* Verify CRC */
if (sc->fcs != PPP_GOODFCS) {
sc->stats.asyncBadCheckSums++;
goto reset;
}
sc->slen -= 2;
/* Strip address and control fields */
if (sc->slen >= 2
&& sc->sbuf[0] == PPP_ALLSTATIONS
&& sc->sbuf[1] == PPP_UI)
skip = 2;
/* Check for frame too big */
if (sc->slen - skip > sc->cfg.amru) {
sc->stats.asyncOverflows++;
goto reset;
}
/* OK, ship it out */
if ((n = m_devget(sc->sbuf + skip,
sc->slen - skip, 0, rcvif, NULL))) {
if (item) { /* sets NULL -> item */
NG_FWD_NEW_DATA(error, item,
sc->sync, n);
} else {
NG_SEND_DATA_ONLY(error,
sc->sync ,n);
}
}
sc->stats.asyncFrames++;
reset:
sc->amode = MODE_NORMAL;
sc->fcs = PPP_INITFCS;
sc->slen = 0;
continue;
}
switch (sc->amode) {
case MODE_NORMAL:
if (ch == PPP_ESCAPE) {
sc->amode = MODE_ESC;
continue;
}
break;
case MODE_ESC:
ch ^= PPP_TRANS;
sc->amode = MODE_NORMAL;
break;
case MODE_HUNT:
default:
continue;
}
/* Add byte to frame */
if (sc->slen >= SYNC_BUF_SIZE(sc->cfg.amru)) {
sc->stats.asyncOverflows++;
sc->amode = MODE_HUNT;
sc->slen = 0;
} else {
sc->sbuf[sc->slen++] = ch;
sc->fcs = PPP_FCS(sc->fcs, ch);
}
}
m = m_free(m);
}
if (item)
NG_FREE_ITEM(item);
return (0);
}
/*
* CRC table
*
* Taken from RFC 1171 Appendix B
*/
static const u_int16_t fcstab[256] = {
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};
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