freebsd-skq/sys/netgraph/ng_async.c
julian 0c949560a1 Divorce the kernel binary ABI version number from the message
format version number. (userland programs should not need to be
recompiled when the netgraph kernel internal ABI is changed.

Also fix modules that don;t handle the fact that a caller may not supply
a return message pointer. (benign at the moment because the calling code
checks, but that will change)
2000-12-18 20:03:32 +00:00

614 lines
16 KiB
C

/*
* 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>
/* 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, struct mbuf *m, meta_p meta);
static int nga_rcv_async(const sc_p sc, struct mbuf *m, meta_p meta);
/* Parse type for struct ng_async_cfg */
static const struct ng_parse_struct_info
nga_config_type_info = NG_ASYNC_CONFIG_TYPE_INFO;
static const struct ng_parse_type nga_config_type = {
&ng_parse_struct_type,
&nga_config_type_info
};
/* Parse type for struct ng_async_stat */
static const struct ng_parse_struct_info
nga_stats_type_info = NG_ASYNC_STATS_TYPE_INFO;
static const struct ng_parse_type nga_stats_type = {
&ng_parse_struct_type,
&nga_stats_type_info,
};
/* 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 = {
NG_ABI_VERSION,
NG_ASYNC_NODE_TYPE,
NULL,
nga_constructor,
nga_rcvmsg,
nga_shutdown,
nga_newhook,
NULL,
NULL,
nga_rcvdata,
nga_disconnect,
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 *nodep)
{
sc_p sc;
int error;
if ((error = ng_make_node_common(&typestruct, nodep)))
return (error);
MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, 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, M_NOWAIT);
if (sc->abuf == NULL)
goto fail;
MALLOC(sc->sbuf, u_char *,
SYNC_BUF_SIZE(sc->cfg.amru), M_NETGRAPH, M_NOWAIT);
if (sc->sbuf == NULL) {
FREE(sc->abuf, M_NETGRAPH);
fail:
FREE(sc, M_NETGRAPH);
return (ENOMEM);
}
(*nodep)->private = sc;
sc->node = *nodep;
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 = node->private;
hook_p *hookp;
if (!strcmp(name, NG_ASYNC_HOOK_ASYNC))
hookp = &sc->async;
else if (!strcmp(name, NG_ASYNC_HOOK_SYNC))
hookp = &sc->sync;
else
return (EINVAL);
if (*hookp)
return (EISCONN);
*hookp = hook;
return (0);
}
/*
* Receive incoming data
*/
static int
nga_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp)
{
const sc_p sc = hook->node->private;
if (hook == sc->sync)
return (nga_rcv_sync(sc, m, meta));
if (hook == sc->async)
return (nga_rcv_async(sc, m, meta));
panic(__FUNCTION__);
}
/*
* Receive incoming control message
*/
static int
nga_rcvmsg(node_p node, struct ng_mesg *msg,
const char *rtn, struct ng_mesg **rptr, hook_p lasthook)
{
const sc_p sc = (sc_p) node->private;
struct ng_mesg *resp = NULL;
int error = 0;
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, M_NOWAIT);
if (!buf)
ERROUT(ENOMEM);
FREE(sc->abuf, M_NETGRAPH);
sc->abuf = buf;
}
if (cfg->amru > sc->cfg.amru) { /* reallocate buffer */
MALLOC(buf, u_char *, SYNC_BUF_SIZE(cfg->amru),
M_NETGRAPH, M_NOWAIT);
if (!buf)
ERROUT(ENOMEM);
FREE(sc->sbuf, M_NETGRAPH);
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);
}
if (rptr)
*rptr = resp;
else if (resp)
FREE(resp, M_NETGRAPH);
done:
FREE(msg, M_NETGRAPH);
return (error);
}
/*
* Shutdown this node
*/
static int
nga_shutdown(node_p node)
{
const sc_p sc = node->private;
ng_cutlinks(node);
ng_unname(node);
FREE(sc->abuf, M_NETGRAPH);
FREE(sc->sbuf, M_NETGRAPH);
bzero(sc, sizeof(*sc));
FREE(sc, M_NETGRAPH);
node->private = NULL;
ng_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 = hook->node->private;
hook_p *hookp;
if (hook == sc->async)
hookp = &sc->async;
else if (hook == sc->sync)
hookp = &sc->sync;
else
panic(__FUNCTION__);
if (!*hookp)
panic(__FUNCTION__ "2");
*hookp = NULL;
bzero(&sc->stats, sizeof(sc->stats));
sc->lasttime = 0;
if (hook->node->numhooks == 0)
ng_rmnode(hook->node);
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, struct mbuf *m, meta_p meta)
{
struct ifnet *const rcvif = m->m_pkthdr.rcvif;
int alen, error = 0;
struct timeval time;
u_int16_t fcs, fcs0;
u_int32_t accm;
#define ADD_BYTE(x) nga_async_add(sc, &fcs, accm, &alen, (x))
/* Check for bypass mode */
if (!sc->cfg.enabled) {
NG_SEND_DATA(error, sc->async, m, meta);
return (error);
}
/* 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_DATA(m, meta);
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) {
struct mbuf *n;
while (m->m_len > 0) {
ADD_BYTE(*mtod(m, u_char *));
m->m_data++;
m->m_len--;
}
MFREE(m, n);
m = n;
}
/* 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_META(meta);
error = ENOBUFS;
} else
NG_SEND_DATA(error, sc->async, m, meta);
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, struct mbuf * m, meta_p meta)
{
struct ifnet *const rcvif = m->m_pkthdr.rcvif;
int error;
if (!sc->cfg.enabled) {
NG_SEND_DATA(error, sc->sync, m, meta);
return (error);
}
NG_FREE_META(meta);
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)))
NG_SEND_DATA(error, sc->sync, n, meta);
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);
}
}
MFREE(m, n);
m = n;
}
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
};