/* * 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 * * $FreeBSD$ * $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 #include #include #include #include #include #include #include #include #include #include /* 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_VERSION, NG_ASYNC_NODE_TYPE, NULL, nga_constructor, nga_rcvmsg, nga_shutdown, nga_newhook, NULL, NULL, nga_rcvdata, 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) { 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 };