/*- * Copyright (c) 2006 Alexander Motin * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice unmodified, this list of conditions, and the following * disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/sys/netgraph/ng_pred1.c,v 1.3 2008/01/27 02:04:12 mav Exp $ * $DragonFly: src/sys/netgraph7/ng_pred1.c,v 1.2 2008/06/26 23:05:35 dillon Exp $ */ /* * Predictor-1 PPP compression netgraph node type. */ #include #include #include #include #include #include #include #include "ng_message.h" #include "netgraph.h" #include "ng_parse.h" #include "ng_pred1.h" #include "opt_netgraph.h" MALLOC_DEFINE(M_NETGRAPH_PRED1, "netgraph_pred1", "netgraph pred1 node "); /* PRED1 header length */ #define PRED1_HDRLEN 2 #define PRED1_TABLE_SIZE 0x10000 #define PRED1_BUF_SIZE 4096 #define PPP_INITFCS 0xffff /* Initial FCS value */ #define PPP_GOODFCS 0xf0b8 /* Good final FCS value */ /* * The following hash code is the heart of the algorithm: * it builds a sliding hash sum of the previous 3-and-a-bit * characters which will be used to index the guess table. * A better hash function would result in additional compression, * at the expense of time. */ #define HASH(x) priv->Hash = (priv->Hash << 4) ^ (x) /* Node private data */ struct ng_pred1_private { struct ng_pred1_config cfg; /* configuration */ u_char GuessTable[PRED1_TABLE_SIZE]; /* dictionary */ u_char inbuf[PRED1_BUF_SIZE]; /* input buffer */ u_char outbuf[PRED1_BUF_SIZE]; /* output buffer */ struct ng_pred1_stats stats; /* statistics */ uint16_t Hash; ng_ID_t ctrlnode; /* path to controlling node */ uint16_t seqnum; /* sequence number */ u_char compress; /* compress/decompress flag */ }; typedef struct ng_pred1_private *priv_p; /* Netgraph node methods */ static ng_constructor_t ng_pred1_constructor; static ng_rcvmsg_t ng_pred1_rcvmsg; static ng_shutdown_t ng_pred1_shutdown; static ng_newhook_t ng_pred1_newhook; static ng_rcvdata_t ng_pred1_rcvdata; static ng_disconnect_t ng_pred1_disconnect; /* Helper functions */ static int ng_pred1_compress(node_p node, struct mbuf *m, struct mbuf **resultp); static int ng_pred1_decompress(node_p node, struct mbuf *m, struct mbuf **resultp); static void Pred1Init(node_p node); static int Pred1Compress(node_p node, u_char *source, u_char *dest, int len); static int Pred1Decompress(node_p node, u_char *source, u_char *dest, int slen, int dlen); static void Pred1SyncTable(node_p node, u_char *source, int len); static uint16_t Crc16(uint16_t fcs, u_char *cp, int len); static const uint16_t Crc16Table[]; /* Parse type for struct ng_pred1_config. */ static const struct ng_parse_struct_field ng_pred1_config_type_fields[] = NG_PRED1_CONFIG_INFO; static const struct ng_parse_type ng_pred1_config_type = { &ng_parse_struct_type, ng_pred1_config_type_fields }; /* Parse type for struct ng_pred1_stat. */ static const struct ng_parse_struct_field ng_pred1_stats_type_fields[] = NG_PRED1_STATS_INFO; static const struct ng_parse_type ng_pred1_stat_type = { &ng_parse_struct_type, ng_pred1_stats_type_fields }; /* List of commands and how to convert arguments to/from ASCII. */ static const struct ng_cmdlist ng_pred1_cmds[] = { { NGM_PRED1_COOKIE, NGM_PRED1_CONFIG, "config", &ng_pred1_config_type, NULL }, { NGM_PRED1_COOKIE, NGM_PRED1_RESETREQ, "resetreq", NULL, NULL }, { NGM_PRED1_COOKIE, NGM_PRED1_GET_STATS, "getstats", NULL, &ng_pred1_stat_type }, { NGM_PRED1_COOKIE, NGM_PRED1_CLR_STATS, "clrstats", NULL, NULL }, { NGM_PRED1_COOKIE, NGM_PRED1_GETCLR_STATS, "getclrstats", NULL, &ng_pred1_stat_type }, { 0 } }; /* Node type descriptor */ static struct ng_type ng_pred1_typestruct = { .version = NG_ABI_VERSION, .name = NG_PRED1_NODE_TYPE, .constructor = ng_pred1_constructor, .rcvmsg = ng_pred1_rcvmsg, .shutdown = ng_pred1_shutdown, .newhook = ng_pred1_newhook, .rcvdata = ng_pred1_rcvdata, .disconnect = ng_pred1_disconnect, .cmdlist = ng_pred1_cmds, }; NETGRAPH_INIT(pred1, &ng_pred1_typestruct); #define ERROUT(x) do { error = (x); goto done; } while (0) /************************************************************************ NETGRAPH NODE STUFF ************************************************************************/ /* * Node type constructor */ static int ng_pred1_constructor(node_p node) { priv_p priv; /* Allocate private structure. */ priv = kmalloc(sizeof(*priv), M_NETGRAPH_PRED1, M_WAITOK | M_ZERO); NG_NODE_SET_PRIVATE(node, priv); /* This node is not thread safe. */ NG_NODE_FORCE_WRITER(node); /* Done */ return (0); } /* * Give our OK for a hook to be added. */ static int ng_pred1_newhook(node_p node, hook_p hook, const char *name) { const priv_p priv = NG_NODE_PRIVATE(node); if (NG_NODE_NUMHOOKS(node) > 0) return (EINVAL); if (strcmp(name, NG_PRED1_HOOK_COMP) == 0) priv->compress = 1; else if (strcmp(name, NG_PRED1_HOOK_DECOMP) == 0) priv->compress = 0; else return (EINVAL); return (0); } /* * Receive a control message. */ static int ng_pred1_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); if (msg->header.typecookie != NGM_PRED1_COOKIE) ERROUT(EINVAL); switch (msg->header.cmd) { case NGM_PRED1_CONFIG: { struct ng_pred1_config *const cfg = (struct ng_pred1_config *)msg->data; /* Check configuration. */ if (msg->header.arglen != sizeof(*cfg)) ERROUT(EINVAL); /* Configuration is OK, reset to it. */ priv->cfg = *cfg; /* Save return address so we can send reset-req's. */ priv->ctrlnode = NGI_RETADDR(item); /* Clear our state. */ Pred1Init(node); break; } case NGM_PRED1_RESETREQ: Pred1Init(node); break; case NGM_PRED1_GET_STATS: case NGM_PRED1_CLR_STATS: case NGM_PRED1_GETCLR_STATS: { /* Create response. */ if (msg->header.cmd != NGM_PRED1_CLR_STATS) { NG_MKRESPONSE(resp, msg, sizeof(struct ng_pred1_stats), M_WAITOK | M_NULLOK); if (resp == NULL) ERROUT(ENOMEM); bcopy(&priv->stats, resp->data, sizeof(struct ng_pred1_stats)); } if (msg->header.cmd != NGM_PRED1_GET_STATS) bzero(&priv->stats, sizeof(struct ng_pred1_stats)); break; } default: error = EINVAL; break; } done: NG_RESPOND_MSG(error, node, item, resp); NG_FREE_MSG(msg); return (error); } /* * Receive incoming data on our hook. */ static int ng_pred1_rcvdata(hook_p hook, item_p item) { const node_p node = NG_HOOK_NODE(hook); const priv_p priv = NG_NODE_PRIVATE(node); struct mbuf *m, *out; int error; if (!priv->cfg.enable) { NG_FREE_ITEM(item); return (ENXIO); } NGI_GET_M(item, m); /* Compress. */ if (priv->compress) { if ((error = ng_pred1_compress(node, m, &out)) != 0) { NG_FREE_ITEM(item); log(LOG_NOTICE, "%s: error: %d\n", __func__, error); return (error); } } else { /* Decompress. */ if ((error = ng_pred1_decompress(node, m, &out)) != 0) { NG_FREE_ITEM(item); log(LOG_NOTICE, "%s: error: %d\n", __func__, error); if (priv->ctrlnode != 0) { struct ng_mesg *msg; /* Need to send a reset-request. */ NG_MKMESSAGE(msg, NGM_PRED1_COOKIE, NGM_PRED1_RESETREQ, 0, M_WAITOK | M_NULLOK); if (msg == NULL) return (error); NG_SEND_MSG_ID(error, node, msg, priv->ctrlnode, 0); } return (error); } } NG_FWD_NEW_DATA(error, item, hook, out); return (error); } /* * Destroy node. */ static int ng_pred1_shutdown(node_p node) { const priv_p priv = NG_NODE_PRIVATE(node); kfree(priv, M_NETGRAPH_PRED1); NG_NODE_SET_PRIVATE(node, NULL); NG_NODE_UNREF(node); /* Let the node escape. */ return (0); } /* * Hook disconnection */ static int ng_pred1_disconnect(hook_p hook) { const node_p node = NG_HOOK_NODE(hook); Pred1Init(node); /* Go away if no longer connected. */ if ((NG_NODE_NUMHOOKS(node) == 0) && NG_NODE_IS_VALID(node)) ng_rmnode_self(node); return (0); } /************************************************************************ HELPER STUFF ************************************************************************/ /* * Compress/encrypt a packet and put the result in a new mbuf at *resultp. * The original mbuf is not free'd. */ static int ng_pred1_compress(node_p node, struct mbuf *m, struct mbuf **resultp) { const priv_p priv = NG_NODE_PRIVATE(node); int outlen, inlen; u_char *out; uint16_t fcs, lenn; int len; /* Initialize. */ *resultp = NULL; inlen = m->m_pkthdr.len; priv->stats.FramesPlain++; priv->stats.InOctets += inlen; /* Reserve space for expansion. */ if (inlen > (PRED1_BUF_SIZE*8/9 + 1 + 4)) { priv->stats.Errors++; NG_FREE_M(m); return (ENOMEM); } /* Work with contiguous regions of memory. */ m_copydata(m, 0, inlen, (caddr_t)(priv->inbuf + 2)); NG_FREE_M(m); lenn = htons(inlen & 0x7FFF); /* Compute FCS. */ fcs = Crc16(PPP_INITFCS, (u_char *)&lenn, 2); fcs = Crc16(fcs, priv->inbuf + 2, inlen); fcs = ~fcs; /* Compress data. */ len = Pred1Compress(node, priv->inbuf + 2, priv->outbuf + 2, inlen); /* What happened? */ if (len < inlen) { out = priv->outbuf; outlen = 2 + len; *(uint16_t *)out = lenn; *out |= 0x80; priv->stats.FramesComp++; } else { out = priv->inbuf; outlen = 2 + inlen; *(uint16_t *)out = lenn; priv->stats.FramesUncomp++; } /* Add FCS. */ (out + outlen)[0] = fcs & 0xFF; (out + outlen)[1] = fcs >> 8; /* Calculate resulting size. */ outlen += 2; /* Return packet in an mbuf. */ *resultp = m_devget((caddr_t)out, outlen, 0, NULL, NULL); if (*resultp == NULL) { priv->stats.Errors++; return (ENOMEM); }; priv->stats.OutOctets += outlen; return (0); } /* * Decompress/decrypt packet and put the result in a new mbuf at *resultp. * The original mbuf is not free'd. */ static int ng_pred1_decompress(node_p node, struct mbuf *m, struct mbuf **resultp) { const priv_p priv = NG_NODE_PRIVATE(node); int inlen; uint16_t len, len1, cf, lenn; uint16_t fcs; /* Initialize. */ *resultp = NULL; inlen = m->m_pkthdr.len; if (inlen > PRED1_BUF_SIZE) { priv->stats.Errors++; NG_FREE_M(m); return (ENOMEM); } /* Work with contiguous regions of memory. */ m_copydata(m, 0, inlen, (caddr_t)priv->inbuf); priv->stats.InOctets += inlen; /* Get initial length value. */ len = priv->inbuf[0] << 8; len += priv->inbuf[1]; cf = (len & 0x8000); len &= 0x7fff; /* Is data compressed or not really? */ if (cf) { NG_FREE_M(m); priv->stats.FramesComp++; len1 = Pred1Decompress(node, priv->inbuf + 2, priv->outbuf, inlen - 4, PRED1_BUF_SIZE); if (len != len1) { /* Error is detected. Send reset request */ priv->stats.Errors++; log(LOG_NOTICE, "ng_pred1: Comp length error (%d) " "--> len (%d)\n", len, len1); return (EIO); } /* * CRC check on receive is defined in RFC. It is surely required * for compressed frames to signal dictionary corruption, * but it is actually useless for uncompressed frames because * the same check has already done by HDLC and/or other layer. */ lenn = htons(len); fcs = Crc16(PPP_INITFCS, (u_char *)&lenn, 2); fcs = Crc16(fcs, priv->outbuf, len); fcs = Crc16(fcs, priv->inbuf + inlen - 2, 2); if (fcs != PPP_GOODFCS) { priv->stats.Errors++; log(LOG_NOTICE, "ng_pred1: Pred1: Bad CRC-16\n"); return (EIO); } /* Return packet in an mbuf. */ *resultp = m_devget((caddr_t)priv->outbuf, len, 0, NULL, NULL); if (*resultp == NULL) { priv->stats.Errors++; return (ENOMEM); }; } else { priv->stats.FramesUncomp++; if (len != (inlen - 4)) { /* Wrong length. Send reset request */ priv->stats.Errors++; log(LOG_NOTICE, "ng_pred1: Uncomp length error (%d) " "--> len (%d)\n", len, inlen - 4); NG_FREE_M(m); return (EIO); } Pred1SyncTable(node, priv->inbuf + 2, len); m_adj(m, 2); /* Strip length. */ m_adj(m, -2); /* Strip fcs. */ *resultp = m; } priv->stats.FramesPlain++; priv->stats.OutOctets += len; return (0); } /* * Pred1Init() */ static void Pred1Init(node_p node) { const priv_p priv = NG_NODE_PRIVATE(node); priv->Hash = 0; memset(priv->GuessTable, 0, PRED1_TABLE_SIZE); } /* * Pred1Compress() */ static int Pred1Compress(node_p node, u_char *source, u_char *dest, int len) { const priv_p priv = NG_NODE_PRIVATE(node); int i; u_char flags; u_char *flagdest, *orgdest; orgdest = dest; while (len) { flagdest = dest++; flags = 0; /* All guesses are wrong initially. */ for (i = 0; i < 8 && len; i++) { if (priv->GuessTable[priv->Hash] == *source) /* Guess was right - don't output. */ flags |= (1 << i); else { /* Guess wrong, output char. */ priv->GuessTable[priv->Hash] = *source; *dest++ = *source; } HASH(*source++); len--; } *flagdest = flags; } return (dest - orgdest); } /* * Pred1Decompress() * * Returns decompressed size, or -1 if we ran out of space. */ static int Pred1Decompress(node_p node, u_char *source, u_char *dest, int slen, int dlen) { const priv_p priv = NG_NODE_PRIVATE(node); int i; u_char flags, *orgdest; orgdest = dest; while (slen) { flags = *source++; slen--; for (i = 0; i < 8; i++, flags >>= 1) { if (dlen <= 0) return(-1); if (flags & 0x01) /* Guess correct */ *dest = priv->GuessTable[priv->Hash]; else { if (!slen) /* We seem to be really done -- cabo. */ break; /* Guess wrong. */ priv->GuessTable[priv->Hash] = *source; /* Read from source. */ *dest = *source++; slen--; } HASH(*dest++); dlen--; } } return (dest - orgdest); } /* * Pred1SyncTable() */ static void Pred1SyncTable(node_p node, u_char *source, int len) { const priv_p priv = NG_NODE_PRIVATE(node); while (len--) { priv->GuessTable[priv->Hash] = *source; HASH(*source++); } } /* * Crc16() * * Compute the 16 bit frame check value, per RFC 1171 Appendix B, * on an array of bytes. */ static uint16_t Crc16(uint16_t crc, u_char *cp, int len) { while (len--) crc = (crc >> 8) ^ Crc16Table[(crc ^ *cp++) & 0xff]; return (crc); } static const uint16_t Crc16Table[256] = { /* 00 */ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, /* 08 */ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, /* 10 */ 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, /* 18 */ 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, /* 20 */ 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, /* 28 */ 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, /* 30 */ 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, /* 38 */ 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, /* 40 */ 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, /* 48 */ 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, /* 50 */ 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, /* 58 */ 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, /* 60 */ 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, /* 68 */ 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, /* 70 */ 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, /* 78 */ 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, /* 80 */ 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, /* 88 */ 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, /* 90 */ 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, /* 98 */ 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, /* a0 */ 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, /* a8 */ 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, /* b0 */ 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, /* b8 */ 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, /* c0 */ 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, /* c8 */ 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, /* d0 */ 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, /* d8 */ 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, /* e0 */ 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, /* e8 */ 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, /* f0 */ 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, /* f8 */ 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 };