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 (respcode == CDR_EXECFAILED)
  58                 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_list_neigh(struct conn *rconn)
  92 {
  93         __u32 limit;
  94         __u32 offset;
  95         __u32 len;
  96
  97         char *buf;
  98
  99         if (rconn->target.unconnected.paramlen < 8) {
 100                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
 101                 return;
 102         }
 103
 104         ((char *)&limit)[0] = rconn->target.unconnected.cmdparams[0];
 105         ((char *)&limit)[1] = rconn->target.unconnected.cmdparams[1];
 106         ((char *)&limit)[2] = rconn->target.unconnected.cmdparams[2];
 107         ((char *)&limit)[3] = rconn->target.unconnected.cmdparams[3];
 108
 109         ((char *)&offset)[0] = rconn->target.unconnected.cmdparams[4];
 110         ((char *)&offset)[1] = rconn->target.unconnected.cmdparams[5];
 111         ((char *)&offset)[2] = rconn->target.unconnected.cmdparams[6];
 112         ((char *)&offset)[3] = rconn->target.unconnected.cmdparams[7];
 113
 114         limit = be32_to_cpu(limit);
 115         offset = be32_to_cpu(offset);
 116
 117         buf = kmalloc(2048, GFP_KERNEL);
 118
 119         if (unlikely(buf == 0)) {
 120                 send_resp(rconn, CDR_EXECFAILED,
 121                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES);
 122                 return;
 123         }
 124
 125         send_resp(rconn, CDR_EXECOK, CDR_EXECOK_OK);
 126
 127         len = generate_neigh_list(buf, 2048, limit, offset);
 128         send_resp_bin(rconn, buf, len);
 129 }
 130
 131 static void parse_connect_port(struct conn *rconn)
 132 {
 133         __be64 addr;
 134         int rc;
 135
 136         BUG_ON(0 == rconn->target.unconnected.cmdparams);
 137
 138         if (rconn->target.unconnected.paramlen < 8) {
 139                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
 140                 return;
 141         }
 142
 143         memcpy((char *) &addr, rconn->target.unconnected.cmdparams, 8);
 144
 145         rc = connect_port(rconn, addr);
 146
 147         if (rc == 2) {
 148                 send_resp(rconn, CDR_EXECFAILED,
 149                                 CDR_EXECFAILED_TARGETADDR_DOESNTEXIST);
 150         } else if (rc != 3) {
 151                 send_resp(rconn, CDR_EXECFAILED,
 152                                 CDR_EXECFAILED_LISTENERQUEUE_FULL);
 153         } else if (rc == 0) {
 154                 send_resp(rconn, CDR_EXECOK, CDR_EXECOK_OK);
 155         } else if (unlikely(rc != 0)) {
 156                 BUG();
 157         }
 158 }
 159
 160 static void parse_connect_nb(struct conn *rconn)
 161 {
 162         __u16 addrtypelen;
 163         __u16 addrlen;
 164         __u8 *addrtype;
 165         __u8 *addr;
 166         int rc;
 167
 168         BUG_ON(0 == rconn->target.unconnected.cmdparams);
 169
 170         if (rconn->target.unconnected.paramlen < 4) {
 171                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
 172                 return;
 173         }
 174
 175         ((char *)&addrtypelen)[0] = rconn->target.unconnected.cmdparams[0];
 176         ((char *)&addrtypelen)[1] = rconn->target.unconnected.cmdparams[1];
 177
 178         ((char *)&addrlen)[0] = rconn->target.unconnected.cmdparams[2];
 179         ((char *)&addrlen)[1] = rconn->target.unconnected.cmdparams[3];
 180
 181         addrtypelen = be16_to_cpu(addrtypelen);
 182         addrlen = be16_to_cpu(addrlen);
 183
 184         if ((4 + (__u32) addrtypelen + (__u32) addrlen) >
 185                         rconn->target.unconnected.paramlen) {
 186                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_CMD_TOO_SHORT);
 187                 return;
 188         }
 189
 190         addrtype = rconn->target.unconnected.cmdparams + 4;
 191         addr = addrtype + addrtypelen;
 192
 193         rc = connect_neigh(rconn, addrtypelen, addrtype, addrlen, addr);
 194
 195         if (rc == 2) {
 196                 send_resp(rconn, CDR_EXECFAILED,
 197                                 CDR_EXECFAILED_TARGETADDRTYPE_UNKNOWN);
 198         } else if (rc == 3) {
 199                 send_resp(rconn, CDR_EXECFAILED,
 200                                 CDR_EXECFAILED_TARGETADDR_DOESNTEXIST);
 201         } else if (rc == 4) {
 202                 send_resp(rconn, CDR_EXECFAILED,
 203                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES);
 204         } else if (rc == 0) {
 205                 send_resp(rconn, CDR_EXECOK, CDR_EXECOK_OK);
 206         } else if (unlikely(rc != 0)) {
 207                 BUG();
 208         }
 209 }
 210
 211 static void parse_cmd(struct conn *rconn)
 212 {
 213         __u16 code = rconn->target.unconnected.cmd;
 214
 215         if (code == CD_CONNECT_NB) {
 216                 parse_connect_nb(rconn);
 217         } else if (code == CD_CONNECT_PORT) {
 218                 parse_connect_port(rconn);
 219         } else if (code == CD_LIST_NEIGH) {
 220                 parse_list_neigh(rconn);
 221         } else {
 222                 send_resp(rconn, CDR_EXECFAILED, CDR_EXECFAILED_UNKNOWN_COMMAND);
 223         }
 224 }
 225
 226 static void read_cmd(struct conn *rconn)
 227 {
 228         int pull;
 229
 230         pull = min(rconn->target.unconnected.paramlen + 6 -
 231                         rconn->target.unconnected.cmdread,
 232                         rconn->buf.read_remaining);
 233
 234         BUG_ON(0 > pull);
 235         BUG_ON(0 == rconn->target.unconnected.cmdparams);
 236         BUG_ON(6 > rconn->target.unconnected.cmdread);
 237
 238         if (pull == 0)
 239                 return;
 240
 241         databuf_pull(&(rconn->buf), rconn->target.unconnected.cmdparams +
 242                         rconn->target.unconnected.cmdread - 6, pull);
 243
 244         rconn->target.unconnected.cmdread += pull;
 245 }
 246
 247 static void read_discard(struct conn *rconn)
 248 {
 249         BUG_ON(rconn->target.unconnected.cmdread < 6);
 250
 251         while (rconn->target.unconnected.paramlen + 6 >
 252                         rconn->target.unconnected.cmdread &&
 253                         rconn->buf.read_remaining > 0) {
 254                 char buf[1];
 255                 databuf_pull(&(rconn->buf), buf, 1);
 256
 257                 rconn->target.unconnected.cmdread++;
 258         }
 259 }
 260
 261 static void read_hdr(struct conn *rconn)
 262 {
 263         BUG_ON(rconn->target.unconnected.cmdparams == 0);
 264
 265         while (rconn->target.unconnected.cmdread > 6 &&
 266                         rconn->buf.read_remaining > 0) {
 267
 268                 char buf[1];
 269                 databuf_pull(&(rconn->buf), buf, 1);
 270
 271                 if (2 > rconn->target.unconnected.cmdread) {
 272                         rconn->target.unconnected.cmd <<= 8;
 273                         rconn->target.unconnected.cmd += buf[0];
 274                 } else {
 275                         rconn->target.unconnected.paramlen <<= 8;
 276                         rconn->target.unconnected.paramlen +=
 277                                         buf[0];
 278                 }
 279                 rconn->target.unconnected.cmdread++;
 280         }
 281 }
 282
 283 void parse(struct conn *rconn)
 284 {
 285         __u8 *cmd;
 286
 287         BUG_ON(TARGET_UNCONNECTED != rconn->targettype);
 288
 289         if (rconn->target.unconnected.cmdparams == 0)
 290                 rconn->target.unconnected.cmdparams = kmalloc(MAX_CONN_CMD_LEN,
 291                                 GFP_KERNEL);
 292
 293         cmd = rconn->target.unconnected.cmdparams;
 294
 295         if (rconn->target.unconnected.cmdread == 0) {
 296                 rconn->target.unconnected.cmd = 0;
 297                 rconn->target.unconnected.paramlen = 0;
 298         }
 299
 300         if (rconn->target.unconnected.cmdread < 6) {
 301                 read_hdr(rconn);
 302                 if (rconn->target.unconnected.cmdread < 6)
 303                         return;
 304
 305                 if (rconn->target.unconnected.paramlen > MAX_CONN_CMD_LEN) {
 306                         send_resp(rconn, CDR_EXECFAILED,
 307                                         CDR_EXECFAILED_CMD_TOO_LONG);
 308                 }
 309         }
 310
 311         if (rconn->target.unconnected.paramlen > MAX_CONN_CMD_LEN) {
 312                 read_discard(rconn);
 313                 return;
 314         }
 315
 316         if (rconn->target.unconnected.cmdread >= 6 &&
 317                         rconn->target.unconnected.paramlen >
 318                         rconn->target.unconnected.cmdread - 6) {
 319                 read_cmd(rconn);
 320         }
 321
 322         if (rconn->target.unconnected.paramlen ==
 323                         rconn->target.unconnected.cmdread - 6) {
 324                 rconn->target.unconnected.cmdread = 0;
 325                 parse_cmd(rconn);
 326         }
 327
 328         if (TARGET_UNCONNECTED != rconn->targettype)
 329                 kfree(cmd);
 330 }