net/cor/cpacket_parse.c

   1 /*
   2  *      Connection oriented routing
   3  *      Copyright (C) 2007-2008 Michael Blizek
   4  *
   5  *      This program is free software; you can redistribute it and/or
   6  *      modify it under the terms of the GNU General Public License
   7  *      as published by the Free Software Foundation; either version 2
   8  *      of the License, or (at your option) any later version.
   9  *
  10  *      This program is distributed in the hope that it will be useful,
  11  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *      GNU General Public License for more details.
  14  *
  15  *      You should have received a copy of the GNU General Public License
  16  *      along with this program; if not, write to the Free Software
  17  *      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  *      02110-1301, USA.
  19  */
  20
  21 #include "cor.h"
  22
  23 static char *get_error_reason_text(__u16 reasoncode)
  24 {
  25         if (reasoncode == CDR_EXECFAILED_UNKNOWN_COMMAND)
  26                 return "Unknown command";
  27         else if (reasoncode == CDR_EXECFAILED_PERMISSION_DENIED)
  28                 return "Permission denied";
  29         else if (reasoncode == CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES)
  30                 return "Temporarily out of ressources";
  31         else if (reasoncode == CDR_EXECFAILED_CMD_TOO_SHORT)
  32                 return "The length of the command is too short for all params";
  33         else if (reasoncode == CDR_EXECFAILED_CMD_TOO_LONG)
  34                 return "command param is too long";
  35         else if (reasoncode == CDR_EXECFAILED_TARGETADDRTYPE_UNKNOWN)
  36                 return "targettype unknown";
  37         else if (reasoncode == CDR_EXECFAILED_TARGETADDR_DOESNTEXIST)
  38                 return "targetaddr does not exist";
  39         else if (reasoncode == CDR_EXECFAILED_TARGETADDR_PORTCLOSED)
  40                 return "Port is on open";
  41         else if (reasoncode == CDR_EXECFAILED_LISTENERQUEUE_FULL)
  42                 return "Listener queue full";
  43         else
  44                 return 0;
  45 }
  46
  47 static void send_resp(struct conn *rconn, __u16 respcode,
  48                 __u16 reasoncode)
  49 {
  50         struct conn *sconn = rconn->reversedir;
  51
  52         int reasonlen = 0;
  53         __u16 reasonlen_be;
  54
  55         char *reasontext = 0;
  56
  57         if (unlikely(respcode == CDR_EXECFAILED))
  58                 reasontext = get_error_reason_text(respcode);
  59
  60         if (reasontext)
  61                 reasonlen = strnlen(reasontext, 1024);
  62
  63         respcode = cpu_to_be16(respcode);
  64         reasoncode = cpu_to_be16(reasoncode);
  65         reasonlen_be = cpu_to_be16(reasonlen);
  66
  67         mutex_lock(&(sconn->rcv_lock));
  68         BUG_ON(databuf_maypush(&(sconn->buf)) < (6 + reasonlen));
  69         receive_buf(sconn, (char *) &respcode, 2);
  70         receive_buf(sconn, (char *) &reasoncode, 2);
  71         receive_buf(sconn, (char *) &reasonlen_be, 2);
  72         receive_buf(sconn, reasontext, reasonlen);
  73         mutex_unlock(&(sconn->rcv_lock));
  74 }
  75
  76 static void send_resp_bin(struct conn *rconn, char *buf, __u32 len)
  77 {
  78         struct conn *sconn = rconn->reversedir;
  79
  80         __u32 code = cpu_to_be16(CDR_BINDATA);
  81         __u32 len_be = cpu_to_be32(len);
  82
  83         mutex_lock(&(sconn->rcv_lock));
  84         BUG_ON(databuf_maypush(&(sconn->buf)) < (6 + len));
  85         receive_buf(sconn, (char *) &code, 2);
  86         receive_buf(sconn, (char *) &len_be, 4);
  87         receive_buf(sconn, buf, len);
  88         mutex_unlock(&(sconn->rcv_lock));
  89 }
  90
  91 static void parse_set_timeout(struct conn *rconn, int backwards)
  92 {
  93         __u32 timeout;
  94
  95         if (unlikely(rconn->target.unconnected.paramlen < 4)) {
  96                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
  97                 return;
  98         }
  99
 100         ((char *)&timeout)[0] = rconn->target.unconnected.cmdparams[0];
 101         ((char *)&timeout)[1] = rconn->target.unconnected.cmdparams[1];
 102         ((char *)&timeout)[2] = rconn->target.unconnected.cmdparams[2];
 103         ((char *)&timeout)[3] = rconn->target.unconnected.cmdparams[3];
 104
 105         timeout = be32_to_cpu(timeout);
 106
 107         if (backwards) {
 108                 if (rconn->reversedir->targettype != TARGET_OUT) {
 109                         send_resp(rconn, CDR_EXECFAILED,
 110                                 CDR_EXECFAILED_ILLEGAL_COMMAND);
 111                         return;
 112                 }
 113                 rconn->reversedir->target.out.stall_timeout_ms = timeout;
 114         } else {
 115                 rconn->target.unconnected.stall_timeout_ms = timeout;
 116         }
 117
 118         send_resp(rconn, CDR_EXECOK, CDR_EXECOK_OK);
 119 }
 120
 121 static void parse_list_neigh(struct conn *rconn)
 122 {
 123         __u32 limit;
 124         __u32 offset;
 125         __u32 len;
 126
 127         char *buf;
 128
 129         if (unlikely(rconn->target.unconnected.paramlen < 8)) {
 130                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
 131                 return;
 132         }
 133
 134         ((char *)&limit)[0] = rconn->target.unconnected.cmdparams[0];
 135         ((char *)&limit)[1] = rconn->target.unconnected.cmdparams[1];
 136         ((char *)&limit)[2] = rconn->target.unconnected.cmdparams[2];
 137         ((char *)&limit)[3] = rconn->target.unconnected.cmdparams[3];
 138
 139         ((char *)&offset)[0] = rconn->target.unconnected.cmdparams[4];
 140         ((char *)&offset)[1] = rconn->target.unconnected.cmdparams[5];
 141         ((char *)&offset)[2] = rconn->target.unconnected.cmdparams[6];
 142         ((char *)&offset)[3] = rconn->target.unconnected.cmdparams[7];
 143
 144         limit = be32_to_cpu(limit);
 145         offset = be32_to_cpu(offset);
 146
 147         buf = kmalloc(2048, GFP_KERNEL);
 148
 149         if (unlikely(buf == 0)) {
 150                 send_resp(rconn, CDR_EXECFAILED,
 151                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES);
 152                 return;
 153         }
 154
 155         send_resp(rconn, CDR_EXECOK, CDR_EXECOK_OK);
 156
 157         len = generate_neigh_list(buf, 2048, limit, offset);
 158         send_resp_bin(rconn, buf, len);
 159 }
 160
 161 static void parse_connect_port(struct conn *rconn)
 162 {
 163         __be64 addr;
 164         int rc;
 165
 166         BUG_ON(0 == rconn->target.unconnected.cmdparams);
 167
 168         if (unlikely(rconn->target.unconnected.paramlen < 8)) {
 169                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
 170                 return;
 171         }
 172
 173         memcpy((char *) &addr, rconn->target.unconnected.cmdparams, 8);
 174
 175         rc = connect_port(rconn, addr);
 176
 177         if (rc == 0) {
 178                 send_resp(rconn, CDR_EXECOK, CDR_EXECOK_OK);
 179         } else if (rc == 2) {
 180                 send_resp(rconn, CDR_EXECFAILED,
 181                                 CDR_EXECFAILED_TARGETADDR_DOESNTEXIST);
 182         } else if (rc == 3) {
 183                 send_resp(rconn, CDR_EXECFAILED,
 184                                 CDR_EXECFAILED_LISTENERQUEUE_FULL);
 185         } else {
 186                 BUG();
 187         }
 188 }
 189
 190 static void parse_connect_nb(struct conn *rconn)
 191 {
 192         __u16 addrtypelen;
 193         __u16 addrlen;
 194         __u8 *addrtype;
 195         __u8 *addr;
 196         int rc;
 197
 198         BUG_ON(0 == rconn->target.unconnected.cmdparams);
 199
 200         if (unlikely(rconn->target.unconnected.paramlen < 4)) {
 201                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
 202                 return;
 203         }
 204
 205         ((char *)&addrtypelen)[0] = rconn->target.unconnected.cmdparams[0];
 206         ((char *)&addrtypelen)[1] = rconn->target.unconnected.cmdparams[1];
 207
 208         ((char *)&addrlen)[0] = rconn->target.unconnected.cmdparams[2];
 209         ((char *)&addrlen)[1] = rconn->target.unconnected.cmdparams[3];
 210
 211         addrtypelen = be16_to_cpu(addrtypelen);
 212         addrlen = be16_to_cpu(addrlen);
 213
 214         if (unlikely((4 + (__u32) addrtypelen + (__u32) addrlen) >
 215                         rconn->target.unconnected.paramlen)) {
 216                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
 217                 return;
 218         }
 219
 220         addrtype = rconn->target.unconnected.cmdparams + 4;
 221         addr = addrtype + addrtypelen;
 222
 223         rc = connect_neigh(rconn, addrtypelen, addrtype, addrlen, addr);
 224
 225         if (rc == 0) {
 226                 send_resp(rconn, CDR_EXECOK, CDR_EXECOK_OK);
 227         } else if (rc == 2) {
 228                 send_resp(rconn, CDR_EXECFAILED,
 229                                 CDR_EXECFAILED_TARGETADDRTYPE_UNKNOWN);
 230         } else if (rc == 3) {
 231                 send_resp(rconn, CDR_EXECFAILED,
 232                                 CDR_EXECFAILED_TARGETADDR_DOESNTEXIST);
 233         } else if (rc == 4) {
 234                 send_resp(rconn, CDR_EXECFAILED,
 235                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES);
 236         } else {
 237                 BUG();
 238         }
 239 }
 240
 241 static void parse_cmd(struct conn *rconn)
 242 {
 243         __u16 code = rconn->target.unconnected.cmd;
 244
 245         if (code == CD_CONNECT_NB) {
 246                 parse_connect_nb(rconn);
 247         } else if (code == CD_CONNECT_PORT) {
 248                 parse_connect_port(rconn);
 249         } else if (code == CD_LIST_NEIGH) {
 250                 parse_list_neigh(rconn);
 251         } else if (code == CD_SET_FORWARD_TIMEOUT) {
 252                 parse_set_timeout(rconn, 0);
 253         } else if (code == CD_SET_BACKWARD_TIMEOUT) {
 254                 parse_set_timeout(rconn, 1);
 255         } else {
 256                 send_resp(rconn, CDR_EXECFAILED,
 257                                 CDR_EXECFAILED_UNKNOWN_COMMAND);
 258         }
 259 }
 260
 261 static void read_cmd(struct conn *rconn)
 262 {
 263         int pull;
 264
 265         pull = min(rconn->target.unconnected.paramlen + 6 -
 266                         rconn->target.unconnected.cmdread,
 267                         rconn->buf.read_remaining);
 268
 269         BUG_ON(0 > pull);
 270         BUG_ON(0 == rconn->target.unconnected.cmdparams);
 271         BUG_ON(6 > rconn->target.unconnected.cmdread);
 272
 273         if (pull == 0)
 274                 return;
 275
 276         databuf_pull(&(rconn->buf), rconn->target.unconnected.cmdparams +
 277                         rconn->target.unconnected.cmdread - 6, pull);
 278         databuf_ackread(rconn);
 279
 280         rconn->target.unconnected.cmdread += pull;
 281 }
 282
 283 static void read_discard(struct conn *rconn)
 284 {
 285         BUG_ON(rconn->target.unconnected.cmdread < 6);
 286
 287         while (rconn->target.unconnected.paramlen + 6 <
 288                         rconn->target.unconnected.cmdread &&
 289                         rconn->buf.read_remaining > 0) {
 290                 char buf[1];
 291                 databuf_pull(&(rconn->buf), buf, 1);
 292                 databuf_ackread(rconn);
 293
 294                 rconn->target.unconnected.cmdread++;
 295         }
 296 }
 297
 298 static void read_hdr(struct conn *rconn)
 299 {
 300         BUG_ON(rconn->target.unconnected.cmdparams == 0);
 301
 302         while (rconn->target.unconnected.cmdread < 6 &&
 303                         rconn->buf.read_remaining > 0) {
 304
 305                 char buf[1];
 306                 databuf_pull(&(rconn->buf), buf, 1);
 307                 databuf_ackread(rconn);
 308
 309                 if (2 > rconn->target.unconnected.cmdread) {
 310                         rconn->target.unconnected.cmd <<= 8;
 311                         rconn->target.unconnected.cmd += buf[0];
 312                 } else {
 313                         rconn->target.unconnected.paramlen <<= 8;
 314                         rconn->target.unconnected.paramlen += buf[0];
 315                 }
 316                 rconn->target.unconnected.cmdread++;
 317         }
 318 }
 319
 320 void parse(struct conn *rconn)
 321 {
 322         __u8 *cmd;
 323
 324         BUG_ON(TARGET_UNCONNECTED != rconn->targettype);
 325
 326         if (rconn->target.unconnected.cmdparams == 0)
 327                 rconn->target.unconnected.cmdparams = kmalloc(MAX_CONN_CMD_LEN,
 328                                 GFP_KERNEL);
 329
 330         cmd = rconn->target.unconnected.cmdparams;
 331
 332         if (rconn->target.unconnected.cmdread == 0) {
 333                 rconn->target.unconnected.cmd = 0;
 334                 rconn->target.unconnected.paramlen = 0;
 335         }
 336
 337         if (rconn->target.unconnected.cmdread < 6) {
 338                 read_hdr(rconn);
 339                 if (rconn->target.unconnected.cmdread < 6)
 340                         return;
 341
 342                 if (rconn->target.unconnected.paramlen > MAX_CONN_CMD_LEN) {
 343                         send_resp(rconn, CDR_EXECFAILED,
 344                                         CDR_EXECFAILED_CMD_TOO_LONG);
 345                 }
 346         }
 347
 348         if (rconn->target.unconnected.paramlen > MAX_CONN_CMD_LEN) {
 349                 read_discard(rconn);
 350                 return;
 351         }
 352
 353         if (rconn->target.unconnected.cmdread >= 6 &&
 354                         rconn->target.unconnected.paramlen >
 355                         rconn->target.unconnected.cmdread - 6) {
 356                 read_cmd(rconn);
 357         }
 358
 359         if (rconn->target.unconnected.paramlen ==
 360                         rconn->target.unconnected.cmdread - 6) {
 361                 rconn->target.unconnected.cmdread = 0;
 362                 parse_cmd(rconn);
 363         }
 364
 365         if (rconn->targettype != TARGET_UNCONNECTED)
 366                 kfree(cmd);
 367 }