sys/netgraph7/ng_deflate.c

   1 /*-
   2  * Copyright (c) 2006 Alexander Motin <mav@alkar.net>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice unmodified, this list of conditions, and the following
  10  *    disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  *
  27  * $FreeBSD: src/sys/netgraph/ng_deflate.c,v 1.3 2007/01/15 05:55:56 glebius Exp $
  28  * $DragonFly: src/sys/netgraph7/ng_deflate.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
  29  */
  30
  31 /*
  32  * Deflate PPP compression netgraph node type.
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/kernel.h>
  38 #include <sys/mbuf.h>
  39 #include <sys/malloc.h>
  40 #include <sys/errno.h>
  41 #include <sys/syslog.h>
  42
  43 #include <net/zlib.h>
  44
  45 #include "ng_message.h"
  46 #include "netgraph.h"
  47 #include "ng_parse.h"
  48 #include "ng_deflate.h"
  49
  50 #include "opt_netgraph.h"
  51
  52 MALLOC_DEFINE(M_NETGRAPH_DEFLATE, "netgraph_deflate", "netgraph deflate node ");
  53
  54 /* DEFLATE header length */
  55 #define DEFLATE_HDRLEN          2
  56
  57 #define PROT_COMPD              0x00fd
  58
  59 #define DEFLATE_BUF_SIZE        4096
  60
  61 /* Node private data */
  62 struct ng_deflate_private {
  63         struct ng_deflate_config cfg;           /* configuration */
  64         u_char          inbuf[DEFLATE_BUF_SIZE];        /* input buffer */
  65         u_char          outbuf[DEFLATE_BUF_SIZE];       /* output buffer */
  66         z_stream        cx;                     /* compression context */
  67         struct ng_deflate_stats stats;          /* statistics */
  68         ng_ID_t         ctrlnode;               /* path to controlling node */
  69         uint16_t        seqnum;                 /* sequence number */
  70         u_char          compress;               /* compress/decompress flag */
  71 };
  72 typedef struct ng_deflate_private *priv_p;
  73
  74 /* Netgraph node methods */
  75 static ng_constructor_t ng_deflate_constructor;
  76 static ng_rcvmsg_t      ng_deflate_rcvmsg;
  77 static ng_shutdown_t    ng_deflate_shutdown;
  78 static ng_newhook_t     ng_deflate_newhook;
  79 static ng_rcvdata_t     ng_deflate_rcvdata;
  80 static ng_disconnect_t  ng_deflate_disconnect;
  81
  82 /* Helper functions */
  83 static void     *z_alloc(void *, u_int items, u_int size);
  84 static void     z_free(void *, void *ptr);
  85 static int      ng_deflate_compress(node_p node,
  86                     struct mbuf *m, struct mbuf **resultp);
  87 static int      ng_deflate_decompress(node_p node,
  88                     struct mbuf *m, struct mbuf **resultp);
  89 static void     ng_deflate_reset_req(node_p node);
  90
  91 /* Parse type for struct ng_deflate_config. */
  92 static const struct ng_parse_struct_field ng_deflate_config_type_fields[]
  93         = NG_DEFLATE_CONFIG_INFO;
  94 static const struct ng_parse_type ng_deflate_config_type = {
  95         &ng_parse_struct_type,
  96         ng_deflate_config_type_fields
  97 };
  98
  99 /* Parse type for struct ng_deflate_stat. */
 100 static const struct ng_parse_struct_field ng_deflate_stats_type_fields[]
 101         = NG_DEFLATE_STATS_INFO;
 102 static const struct ng_parse_type ng_deflate_stat_type = {
 103         &ng_parse_struct_type,
 104         ng_deflate_stats_type_fields
 105 };
 106
 107 /* List of commands and how to convert arguments to/from ASCII. */
 108 static const struct ng_cmdlist ng_deflate_cmds[] = {
 109         {
 110           NGM_DEFLATE_COOKIE,
 111           NGM_DEFLATE_CONFIG,
 112           "config",
 113           &ng_deflate_config_type,
 114           NULL
 115         },
 116         {
 117           NGM_DEFLATE_COOKIE,
 118           NGM_DEFLATE_RESETREQ,
 119           "resetreq",
 120           NULL,
 121           NULL
 122         },
 123         {
 124           NGM_DEFLATE_COOKIE,
 125           NGM_DEFLATE_GET_STATS,
 126           "getstats",
 127           NULL,
 128           &ng_deflate_stat_type
 129         },
 130         {
 131           NGM_DEFLATE_COOKIE,
 132           NGM_DEFLATE_CLR_STATS,
 133           "clrstats",
 134           NULL,
 135           NULL
 136         },
 137         {
 138           NGM_DEFLATE_COOKIE,
 139           NGM_DEFLATE_GETCLR_STATS,
 140           "getclrstats",
 141           NULL,
 142           &ng_deflate_stat_type
 143         },
 144         { 0 }
 145 };
 146
 147 /* Node type descriptor */
 148 static struct ng_type ng_deflate_typestruct = {
 149         .version =      NG_ABI_VERSION,
 150         .name =         NG_DEFLATE_NODE_TYPE,
 151         .constructor =  ng_deflate_constructor,
 152         .rcvmsg =       ng_deflate_rcvmsg,
 153         .shutdown =     ng_deflate_shutdown,
 154         .newhook =      ng_deflate_newhook,
 155         .rcvdata =      ng_deflate_rcvdata,
 156         .disconnect =   ng_deflate_disconnect,
 157         .cmdlist =      ng_deflate_cmds,
 158 };
 159 NETGRAPH_INIT(deflate, &ng_deflate_typestruct);
 160
 161 /* Depend on separate zlib module. */
 162 MODULE_DEPEND(ng_deflate, zlib, 1, 1, 1);
 163
 164 #define ERROUT(x)       do { error = (x); goto done; } while (0)
 165
 166 /************************************************************************
 167                         NETGRAPH NODE STUFF
 168  ************************************************************************/
 169
 170 /*
 171  * Node type constructor
 172  */
 173 static int
 174 ng_deflate_constructor(node_p node)
 175 {
 176         priv_p priv;
 177
 178         /* Allocate private structure. */
 179         priv = kmalloc(sizeof(*priv), M_NETGRAPH_DEFLATE, M_WAITOK | M_ZERO);
 180
 181         NG_NODE_SET_PRIVATE(node, priv);
 182
 183         /* This node is not thread safe. */
 184         NG_NODE_FORCE_WRITER(node);
 185
 186         /* Done */
 187         return (0);
 188 }
 189
 190 /*
 191  * Give our OK for a hook to be added.
 192  */
 193 static int
 194 ng_deflate_newhook(node_p node, hook_p hook, const char *name)
 195 {
 196         const priv_p priv = NG_NODE_PRIVATE(node);
 197
 198         if (NG_NODE_NUMHOOKS(node) > 0)
 199                 return (EINVAL);
 200
 201         if (strcmp(name, NG_DEFLATE_HOOK_COMP) == 0)
 202                 priv->compress = 1;
 203         else if (strcmp(name, NG_DEFLATE_HOOK_DECOMP) == 0)
 204                 priv->compress = 0;
 205         else
 206                 return (EINVAL);
 207
 208         return (0);
 209 }
 210
 211 /*
 212  * Receive a control message
 213  */
 214 static int
 215 ng_deflate_rcvmsg(node_p node, item_p item, hook_p lasthook)
 216 {
 217         const priv_p priv = NG_NODE_PRIVATE(node);
 218         struct ng_mesg *resp = NULL;
 219         int error = 0;
 220         struct ng_mesg *msg;
 221
 222         NGI_GET_MSG(item, msg);
 223
 224         if (msg->header.typecookie != NGM_DEFLATE_COOKIE)
 225                 ERROUT(EINVAL);
 226
 227         switch (msg->header.cmd) {
 228         case NGM_DEFLATE_CONFIG:
 229             {
 230                 struct ng_deflate_config *const cfg
 231                     = (struct ng_deflate_config *)msg->data;
 232
 233                 /* Check configuration. */
 234                 if (msg->header.arglen != sizeof(*cfg))
 235                         ERROUT(EINVAL);
 236                 if (cfg->enable) {
 237                     if (cfg->windowBits < 8 || cfg->windowBits > 15)
 238                         ERROUT(EINVAL);
 239                 } else
 240                     cfg->windowBits = 0;
 241
 242                 /* Clear previous state. */
 243                 if (priv->cfg.enable) {
 244                         if (priv->compress)
 245                                 deflateEnd(&priv->cx);
 246                         else
 247                                 inflateEnd(&priv->cx);
 248                         priv->cfg.enable = 0;
 249                 }
 250
 251                 /* Configuration is OK, reset to it. */
 252                 priv->cfg = *cfg;
 253
 254                 if (priv->cfg.enable) {
 255                         priv->cx.next_in = NULL;
 256                         priv->cx.zalloc = z_alloc;
 257                         priv->cx.zfree = z_free;
 258                         int res;
 259                         if (priv->compress) {
 260                                 if ((res = deflateInit2(&priv->cx,
 261                                     Z_DEFAULT_COMPRESSION, Z_DEFLATED,
 262                                     -cfg->windowBits, 8,
 263                                     Z_DEFAULT_STRATEGY)) != Z_OK) {
 264                                         log(LOG_NOTICE,
 265                                             "deflateInit2: error %d, %s\n",
 266                                             res, priv->cx.msg);
 267                                         priv->cfg.enable = 0;
 268                                         ERROUT(ENOMEM);
 269                                 }
 270                         } else {
 271                                 if ((res = inflateInit2(&priv->cx,
 272                                     -cfg->windowBits)) != Z_OK) {
 273                                         log(LOG_NOTICE,
 274                                             "inflateInit2: error %d, %s\n",
 275                                             res, priv->cx.msg);
 276                                         priv->cfg.enable = 0;
 277                                         ERROUT(ENOMEM);
 278                                 }
 279                         }
 280                 }
 281
 282                 /* Initialize other state. */
 283                 priv->seqnum = 0;
 284
 285                 /* Save return address so we can send reset-req's */
 286                 priv->ctrlnode = NGI_RETADDR(item);
 287                 break;
 288             }
 289
 290         case NGM_DEFLATE_RESETREQ:
 291                 ng_deflate_reset_req(node);
 292                 break;
 293
 294         case NGM_DEFLATE_GET_STATS:
 295         case NGM_DEFLATE_CLR_STATS:
 296         case NGM_DEFLATE_GETCLR_STATS:
 297                 /* Create response if requested. */
 298                 if (msg->header.cmd != NGM_DEFLATE_CLR_STATS) {
 299                         NG_MKRESPONSE(resp, msg,
 300                             sizeof(struct ng_deflate_stats), M_WAITOK | M_NULLOK);
 301                         if (resp == NULL)
 302                                 ERROUT(ENOMEM);
 303                         bcopy(&priv->stats, resp->data,
 304                             sizeof(struct ng_deflate_stats));
 305                 }
 306
 307                 /* Clear stats if requested. */
 308                 if (msg->header.cmd != NGM_DEFLATE_GET_STATS)
 309                         bzero(&priv->stats,
 310                             sizeof(struct ng_deflate_stats));
 311                 break;
 312
 313         default:
 314                 error = EINVAL;
 315                 break;
 316         }
 317 done:
 318         NG_RESPOND_MSG(error, node, item, resp);
 319         NG_FREE_MSG(msg);
 320         return (error);
 321 }
 322
 323 /*
 324  * Receive incoming data on our hook.
 325  */
 326 static int
 327 ng_deflate_rcvdata(hook_p hook, item_p item)
 328 {
 329         const node_p node = NG_HOOK_NODE(hook);
 330         const priv_p priv = NG_NODE_PRIVATE(node);
 331         struct mbuf *m, *out;
 332         int error;
 333
 334         if (!priv->cfg.enable) {
 335                 NG_FREE_ITEM(item);
 336                 return (ENXIO);
 337         }
 338
 339         NGI_GET_M(item, m);
 340         /* Compress */
 341         if (priv->compress) {
 342                 if ((error = ng_deflate_compress(node, m, &out)) != 0) {
 343                         NG_FREE_ITEM(item);
 344                         log(LOG_NOTICE, "%s: error: %d\n", __func__, error);
 345                         return (error);
 346                 }
 347
 348         } else { /* Decompress */
 349                 if ((error = ng_deflate_decompress(node, m, &out)) != 0) {
 350                         NG_FREE_ITEM(item);
 351                         log(LOG_NOTICE, "%s: error: %d\n", __func__, error);
 352                         if (priv->ctrlnode != 0) {
 353                                 struct ng_mesg *msg;
 354
 355                                 /* Need to send a reset-request. */
 356                                 NG_MKMESSAGE(msg, NGM_DEFLATE_COOKIE,
 357                                     NGM_DEFLATE_RESETREQ, 0, M_WAITOK | M_NULLOK);
 358                                 if (msg == NULL)
 359                                         return (error);
 360                                 NG_SEND_MSG_ID(error, node, msg,
 361                                         priv->ctrlnode, 0);
 362                         }
 363                         return (error);
 364                 }
 365         }
 366
 367         NG_FWD_NEW_DATA(error, item, hook, out);
 368         return (error);
 369 }
 370
 371 /*
 372  * Destroy node.
 373  */
 374 static int
 375 ng_deflate_shutdown(node_p node)
 376 {
 377         const priv_p priv = NG_NODE_PRIVATE(node);
 378
 379         /* Take down netgraph node. */
 380         if (priv->cfg.enable) {
 381             if (priv->compress)
 382                 deflateEnd(&priv->cx);
 383             else
 384                 inflateEnd(&priv->cx);
 385         }
 386
 387         kfree(priv, M_NETGRAPH_DEFLATE);
 388         NG_NODE_SET_PRIVATE(node, NULL);
 389         NG_NODE_UNREF(node);            /* let the node escape */
 390         return (0);
 391 }
 392
 393 /*
 394  * Hook disconnection
 395  */
 396 static int
 397 ng_deflate_disconnect(hook_p hook)
 398 {
 399         const node_p node = NG_HOOK_NODE(hook);
 400         const priv_p priv = NG_NODE_PRIVATE(node);
 401
 402         if (priv->cfg.enable) {
 403             if (priv->compress)
 404                 deflateEnd(&priv->cx);
 405             else
 406                 inflateEnd(&priv->cx);
 407             priv->cfg.enable = 0;
 408         }
 409
 410         /* Go away if no longer connected. */
 411         if ((NG_NODE_NUMHOOKS(node) == 0) && NG_NODE_IS_VALID(node))
 412                 ng_rmnode_self(node);
 413         return (0);
 414 }
 415
 416 /************************************************************************
 417                         HELPER STUFF
 418  ************************************************************************/
 419
 420 /*
 421  * Space allocation and freeing routines for use by zlib routines.
 422  */
 423
 424 static void *
 425 z_alloc(void *notused, u_int items, u_int size)
 426 {
 427
 428         return (kmalloc(items * size, M_NETGRAPH_DEFLATE, M_WAITOK | M_NULLOK));
 429 }
 430
 431 static void
 432 z_free(void *notused, void *ptr)
 433 {
 434
 435         kfree(ptr, M_NETGRAPH_DEFLATE);
 436 }
 437
 438 /*
 439  * Compress/encrypt a packet and put the result in a new mbuf at *resultp.
 440  * The original mbuf is not free'd.
 441  */
 442 static int
 443 ng_deflate_compress(node_p node, struct mbuf *m, struct mbuf **resultp)
 444 {
 445         const priv_p    priv = NG_NODE_PRIVATE(node);
 446         int             outlen, inlen;
 447         int             rtn;
 448
 449         /* Initialize. */
 450         *resultp = NULL;
 451
 452         inlen = m->m_pkthdr.len;
 453
 454         priv->stats.FramesPlain++;
 455         priv->stats.InOctets+=inlen;
 456
 457         if (inlen > DEFLATE_BUF_SIZE) {
 458                 priv->stats.Errors++;
 459                 NG_FREE_M(m);
 460                 return (ENOMEM);
 461         }
 462
 463         /* Work with contiguous regions of memory. */
 464         m_copydata(m, 0, inlen, (caddr_t)priv->inbuf);
 465         outlen = DEFLATE_BUF_SIZE;
 466
 467         /* Compress "inbuf" into "outbuf". */
 468         /* Prepare to compress. */
 469         if (priv->inbuf[0] != 0) {
 470                 priv->cx.next_in = priv->inbuf;
 471                 priv->cx.avail_in = inlen;
 472         } else {
 473                 priv->cx.next_in = priv->inbuf + 1; /* compress protocol */
 474                 priv->cx.avail_in = inlen - 1;
 475         }
 476         priv->cx.next_out = priv->outbuf + 2 + DEFLATE_HDRLEN;
 477         priv->cx.avail_out = outlen - 2 - DEFLATE_HDRLEN;
 478
 479         /* Compress. */
 480         rtn = deflate(&priv->cx, Z_PACKET_FLUSH);
 481
 482         /* Check return value. */
 483         if (rtn != Z_OK) {
 484                 priv->stats.Errors++;
 485                 log(LOG_NOTICE, "ng_deflate: compression error: %d (%s)\n",
 486                     rtn, priv->cx.msg);
 487                 NG_FREE_M(m);
 488                 return (EINVAL);
 489         }
 490
 491         /* Calculate resulting size. */
 492         outlen -= priv->cx.avail_out;
 493
 494         /* If we can't compress this packet, send it as-is. */
 495         if (outlen > inlen) {
 496                 /* Return original packet uncompressed. */
 497                 *resultp = m;
 498                 priv->stats.FramesUncomp++;
 499                 priv->stats.OutOctets+=inlen;
 500         } else {
 501                 NG_FREE_M(m);
 502
 503                 /* Install header. */
 504                 ((u_int16_t *)priv->outbuf)[0] = htons(PROT_COMPD);
 505                 ((u_int16_t *)priv->outbuf)[1] = htons(priv->seqnum);
 506
 507                 /* Return packet in an mbuf. */
 508                 *resultp = m_devget((caddr_t)priv->outbuf, outlen, 0, NULL,
 509                     NULL);
 510                 if (*resultp == NULL) {
 511                         priv->stats.Errors++;
 512                         return (ENOMEM);
 513                 };
 514                 priv->stats.FramesComp++;
 515                 priv->stats.OutOctets+=outlen;
 516         }
 517
 518         /* Update sequence number. */
 519         priv->seqnum++;
 520
 521         return (0);
 522 }
 523
 524 /*
 525  * Decompress/decrypt packet and put the result in a new mbuf at *resultp.
 526  * The original mbuf is not free'd.
 527  */
 528 static int
 529 ng_deflate_decompress(node_p node, struct mbuf *m, struct mbuf **resultp)
 530 {
 531         const priv_p    priv = NG_NODE_PRIVATE(node);
 532         int             outlen, inlen;
 533         int             rtn;
 534         uint16_t        proto;
 535         int             offset;
 536         uint16_t        rseqnum;
 537
 538         /* Initialize. */
 539         *resultp = NULL;
 540
 541         inlen = m->m_pkthdr.len;
 542
 543         if (inlen > DEFLATE_BUF_SIZE) {
 544                 priv->stats.Errors++;
 545                 NG_FREE_M(m);
 546                 priv->seqnum = 0;
 547                 return (ENOMEM);
 548         }
 549
 550         /* Work with contiguous regions of memory. */
 551         m_copydata(m, 0, inlen, (caddr_t)priv->inbuf);
 552
 553         /* Separate proto. */
 554         if ((priv->inbuf[0] & 0x01) != 0) {
 555                 proto = priv->inbuf[0];
 556                 offset = 1;
 557         } else {
 558                 proto = ntohs(((uint16_t *)priv->inbuf)[0]);
 559                 offset = 2;
 560         }
 561
 562         priv->stats.InOctets += inlen;
 563
 564         /* Packet is compressed, so decompress. */
 565         if (proto == PROT_COMPD) {
 566                 priv->stats.FramesComp++;
 567
 568                 /* Check sequence number. */
 569                 rseqnum = ntohs(((uint16_t *)(priv->inbuf + offset))[0]);
 570                 offset += 2;
 571                 if (rseqnum != priv->seqnum) {
 572                         priv->stats.Errors++;
 573                         log(LOG_NOTICE, "ng_deflate: wrong sequence: %u "
 574                             "instead of %u\n", rseqnum, priv->seqnum);
 575                         NG_FREE_M(m);
 576                         priv->seqnum = 0;
 577                         return (EPIPE);
 578                 }
 579
 580                 outlen = DEFLATE_BUF_SIZE;
 581
 582                 /* Decompress "inbuf" into "outbuf". */
 583                 /* Prepare to decompress. */
 584                 priv->cx.next_in = priv->inbuf + offset;
 585                 priv->cx.avail_in = inlen - offset;
 586                 /* Reserve space for protocol decompression. */
 587                 priv->cx.next_out = priv->outbuf + 1;
 588                 priv->cx.avail_out = outlen - 1;
 589
 590                 /* Decompress. */
 591                 rtn = inflate(&priv->cx, Z_PACKET_FLUSH);
 592
 593                 /* Check return value. */
 594                 if (rtn != Z_OK && rtn != Z_STREAM_END) {
 595                         priv->stats.Errors++;
 596                         NG_FREE_M(m);
 597                         priv->seqnum = 0;
 598                         log(LOG_NOTICE, "%s: decompression error: %d (%s)\n",
 599                             __func__, rtn, priv->cx.msg);
 600
 601                         switch (rtn) {
 602                         case Z_MEM_ERROR:
 603                                 return (ENOMEM);
 604                         case Z_DATA_ERROR:
 605                                 return (EIO);
 606                         default:
 607                                 return (EINVAL);
 608                         }
 609                 }
 610
 611                 /* Calculate resulting size. */
 612                 outlen -= priv->cx.avail_out;
 613
 614                 NG_FREE_M(m);
 615
 616                 /* Decompress protocol. */
 617                 if ((priv->outbuf[1] & 0x01) != 0) {
 618                         priv->outbuf[0] = 0;
 619                         /* Return packet in an mbuf. */
 620                         *resultp = m_devget((caddr_t)priv->outbuf, outlen, 0,
 621                             NULL, NULL);
 622                 } else {
 623                         outlen--;
 624                         /* Return packet in an mbuf. */
 625                         *resultp = m_devget((caddr_t)(priv->outbuf + 1),
 626                             outlen, 0, NULL, NULL);
 627                 }
 628                 if (*resultp == NULL) {
 629                         priv->stats.Errors++;
 630                         priv->seqnum = 0;
 631                         return (ENOMEM);
 632                 };
 633                 priv->stats.FramesPlain++;
 634                 priv->stats.OutOctets+=outlen;
 635
 636         } else { /* Packet is not compressed, just update dictionary. */
 637                 priv->stats.FramesUncomp++;
 638                 if (priv->inbuf[0] == 0) {
 639                     priv->cx.next_in = priv->inbuf + 1; /* compress protocol */
 640                     priv->cx.avail_in = inlen - 1;
 641                 } else {
 642                     priv->cx.next_in = priv->inbuf;
 643                     priv->cx.avail_in = inlen;
 644                 }
 645
 646                 rtn = inflateIncomp(&priv->cx);
 647
 648                 /* Check return value */
 649                 if (rtn != Z_OK) {
 650                         priv->stats.Errors++;
 651                         log(LOG_NOTICE, "%s: inflateIncomp error: %d (%s)\n",
 652                             __func__, rtn, priv->cx.msg);
 653                         NG_FREE_M(m);
 654                         priv->seqnum = 0;
 655                         return (EINVAL);
 656                 }
 657
 658                 *resultp = m;
 659                 priv->stats.FramesPlain++;
 660                 priv->stats.OutOctets += inlen;
 661         }
 662
 663         /* Update sequence number. */
 664         priv->seqnum++;
 665
 666         return (0);
 667 }
 668
 669 /*
 670  * The peer has sent us a CCP ResetRequest, so reset our transmit state.
 671  */
 672 static void
 673 ng_deflate_reset_req(node_p node)
 674 {
 675         const priv_p priv = NG_NODE_PRIVATE(node);
 676
 677         priv->seqnum = 0;
 678         if (priv->cfg.enable) {
 679             if (priv->compress)
 680                 deflateReset(&priv->cx);
 681             else
 682                 inflateReset(&priv->cx);
 683         }
 684 }
 685