net/cor/conn_trgt_unconn.c

   1 /**
   2  *      Connection oriented routing
   3  *      Copyright (C) 2007-2021 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 int cor_encode_len(char *buf, int buflen, __u32 len)
  24 {
  25         BUG_ON(buf == 0);
  26         BUG_ON(buflen < 4);
  27
  28         if (len < 128) {
  29                 buf[0] = (__u8) len;
  30                 return 1;
  31         } else if (len < 16512) {
  32                 __u16 len_be = cpu_to_be16(len - 128);
  33                 char *len_p = (char *) &len_be;
  34
  35                 buf[0] = len_p[0] + 128;
  36                 buf[1] = len_p[1];
  37                 return 2;
  38         } else if (len < 1073758336) {
  39                 __u32 len_be = cpu_to_be32(len - 16512);
  40                 char *len_p = (char *) &len_be;
  41
  42                 buf[0] = len_p[0] + 192;
  43                 buf[1] = len_p[1];
  44                 buf[2] = len_p[2];
  45                 buf[3] = len_p[3];
  46                 return 4;
  47         } else {
  48                 return -1;
  49         }
  50 }
  51
  52 int cor_decode_len(char *buf, int buflen, __u32 *len)
  53 {
  54         __u8 b0 = (__u8) buf[0];
  55
  56         *len = 0;
  57
  58         if (buflen >= 1 && b0 < 128) {
  59                 *len = (__u8) buf[0];
  60                 return 1;
  61         } else if (buflen >= 2 && b0 >= 128 && b0 < 192) {
  62                 ((char *) len)[0] = buf[0] - 128;
  63                 ((char *) len)[1] = buf[1];
  64
  65                 *len = be16_to_cpu(*len) + 128;
  66                 return 2;
  67         } else if (buflen >= 4 && b0 >= 192) {
  68                 ((char *) len)[0] = buf[0] - 192;
  69                 ((char *) len)[1] = buf[1];
  70                 ((char *) len)[2] = buf[2];
  71                 ((char *) len)[3] = buf[3];
  72
  73                 *len = be32_to_cpu(*len) + 16512;
  74                 return 4;
  75         } else {
  76                 return 0;
  77         }
  78 }
  79
  80 static void cor_receive_cpacketresp(struct cor_conn *src_unconn_ll, char *buf,
  81                 __u32 len, int *reset_needed)
  82 {
  83         __u32 rc;
  84         if (unlikely((*reset_needed) != 0))
  85                 return;
  86         rc = cor_receive_buf(src_unconn_ll, buf, len, 0, 0);
  87         if (unlikely(rc < len))
  88                 (*reset_needed) = 1;
  89 }
  90
  91
  92 static void cor_send_resp_ok(struct cor_conn *trgt_unconn_ll, int *reset_needed)
  93 {
  94         __u8 respcode = CDR_EXECOK;
  95
  96         cor_receive_cpacketresp(trgt_unconn_ll->reversedir, (char *) &respcode,
  97                         1, reset_needed);
  98 }
  99
 100 static void cor_send_resp_failed(struct cor_conn *trgt_unconn_ll,
 101                 __u16 reasoncode, int *reset_needed)
 102 {
 103         char msg[3];
 104
 105         msg[0] = CDR_EXECFAILED;
 106
 107         cor_put_u16(&(msg[1]), reasoncode);
 108
 109         cor_receive_cpacketresp(trgt_unconn_ll->reversedir, msg, 3,
 110                         reset_needed);
 111 }
 112
 113 static void cor_send_resp_bin(struct cor_conn *trgt_unconn_ll, char *buf,
 114                 __u32 len, int *reset_needed)
 115 {
 116         char hdr[5];
 117         int len_len;
 118
 119         hdr[0] = CDR_BINDATA;
 120         len_len = cor_encode_len(hdr + 1, 4, len);
 121
 122         BUG_ON(len_len <= 0);
 123
 124         cor_receive_cpacketresp(trgt_unconn_ll->reversedir, hdr, len_len + 1,
 125                         reset_needed);
 126         cor_receive_cpacketresp(trgt_unconn_ll->reversedir, buf, len,
 127                         reset_needed);
 128 }
 129
 130 static int cor_proc_bindata(struct cor_conn *trgt_unconn_ll, __u16 cmd,
 131                 int *reset_needed)
 132 {
 133         __u32 len = 0;
 134         char *buf;
 135
 136         buf = kmalloc(CD_RESP_BIN_MAXSIZE, GFP_ATOMIC);
 137         if (unlikely(buf == 0)) {
 138                 cor_send_resp_failed(trgt_unconn_ll,
 139                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES,
 140                                 reset_needed);
 141                 return 1;
 142         }
 143
 144         cor_send_resp_ok(trgt_unconn_ll, reset_needed);
 145
 146         if (cmd == CD_LIST_NEIGH) {
 147                 len = cor_generate_neigh_list(buf, CD_RESP_BIN_MAXSIZE);
 148         } else if (cmd == CD_LIST_SERVICES) {
 149                 len = cor_list_services(buf, CD_RESP_BIN_MAXSIZE);
 150         } else {
 151                 BUG();
 152         }
 153         cor_send_resp_bin(trgt_unconn_ll, buf, len, reset_needed);
 154         return 0;
 155 }
 156
 157 static int cor_proc_connect_port(struct cor_conn *trgt_unconn_ll,
 158                 int *reset_needed)
 159 {
 160         __be32 port;
 161         int rc;
 162
 163         if (unlikely(trgt_unconn_ll->target.unconnected.paramlen < 4)) {
 164                 /* command too short */
 165                 cor_send_resp_failed(trgt_unconn_ll,
 166                                 CDR_EXECFAILED_INVALID_COMMAND, reset_needed);
 167                 return 1;
 168         }
 169
 170         memcpy((char *) &port, trgt_unconn_ll->target.unconnected.cmdparams, 4);
 171
 172         rc = cor_connect_port(trgt_unconn_ll, port);
 173
 174         if (rc == 0) {
 175                 cor_send_resp_ok(trgt_unconn_ll, reset_needed);
 176                 return 0;
 177         } else if (rc == 2) {
 178                 cor_send_resp_failed(trgt_unconn_ll,
 179                                 CDR_EXECFAILED_PORTCLOSED, reset_needed);
 180         } else if (rc == 3) {
 181                 cor_send_resp_failed(trgt_unconn_ll,
 182                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES,
 183                                 reset_needed);
 184         } else {
 185                 BUG();
 186         }
 187         return 1;
 188 }
 189
 190 static int cor_proc_connect_nb(struct cor_conn *trgt_unconn_ll,
 191                 int *reset_needed)
 192 {
 193         char *addr = trgt_unconn_ll->target.unconnected.cmdparams;
 194         __u32 addrlen = trgt_unconn_ll->target.unconnected.paramlen;
 195
 196         int rc;
 197
 198         if (unlikely(addrlen > 65535)) {
 199                 cor_send_resp_failed(trgt_unconn_ll,
 200                                 CDR_EXECFAILED_NB_DOESNTEXIST, reset_needed);
 201                 return 1;
 202         }
 203
 204         rc = cor_connect_neigh(trgt_unconn_ll, addr, (__u16) addrlen);
 205
 206         if (rc == 0) {
 207                 cor_send_resp_ok(trgt_unconn_ll, reset_needed);
 208                 return 0;
 209         } else if (rc == 3) {
 210                 cor_send_resp_failed(trgt_unconn_ll,
 211                                 CDR_EXECFAILED_NB_DOESNTEXIST, reset_needed);
 212         } else if (rc == 4) {
 213                 cor_send_resp_failed(trgt_unconn_ll,
 214                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES,
 215                                 reset_needed);
 216         } else {
 217                 BUG();
 218         }
 219         return 1;
 220 }
 221
 222 static void cor_proc_cmd(struct cor_conn *trgt_unconn_ll, int *reset_needed)
 223 {
 224         __u16 cmd = trgt_unconn_ll->target.unconnected.cmd;
 225         char *params = trgt_unconn_ll->target.unconnected.cmdparams;
 226         int discard_on_error = (cmd & CD_CONTINUE_ON_ERROR_FLAG) == 0;
 227         int rc;
 228
 229         cmd = cmd & (~CD_CONTINUE_ON_ERROR_FLAG);
 230
 231         BUG_ON(trgt_unconn_ll->target.unconnected.cmdparams == 0);
 232
 233         if (cmd == CD_CONNECT_NB) {
 234                 rc = cor_proc_connect_nb(trgt_unconn_ll, reset_needed);
 235         } else if (cmd == CD_CONNECT_PORT) {
 236                 rc = cor_proc_connect_port(trgt_unconn_ll, reset_needed);
 237         } else if (cmd == CD_LIST_NEIGH || cmd == CD_LIST_SERVICES) {
 238                 rc = cor_proc_bindata(trgt_unconn_ll, cmd, reset_needed);
 239         } else {
 240                 cor_send_resp_failed(trgt_unconn_ll,
 241                                 CDR_EXECFAILED_INVALID_COMMAND, reset_needed);
 242                 rc = 1;
 243         }
 244
 245         kfree(params);
 246
 247         if (trgt_unconn_ll->targettype == TARGET_UNCONNECTED) {
 248                 trgt_unconn_ll->target.unconnected.cmdparams = 0;
 249                 trgt_unconn_ll->target.unconnected.cmdread = 0;
 250                 trgt_unconn_ll->target.unconnected.paramlen_read = 0;
 251                 trgt_unconn_ll->target.unconnected.cmd = 0;
 252                 trgt_unconn_ll->target.unconnected.paramlen = 0;
 253
 254                 if (rc != 0 && discard_on_error) {
 255                         trgt_unconn_ll->targettype = TARGET_DISCARD;
 256                 }
 257         }
 258 }
 259
 260 static void cor_read_cmd(struct cor_conn *trgt_unconn_ll)
 261 {
 262         int pull;
 263
 264         pull = min(trgt_unconn_ll->target.unconnected.paramlen -
 265                         trgt_unconn_ll->target.unconnected.cmdread,
 266                         trgt_unconn_ll->data_buf.read_remaining);
 267
 268         BUG_ON(pull < 0);
 269         BUG_ON(trgt_unconn_ll->target.unconnected.cmdparams == 0);
 270
 271         if (pull == 0)
 272                 return;
 273
 274         cor_databuf_pull(trgt_unconn_ll,
 275                         trgt_unconn_ll->target.unconnected.cmdparams +
 276                         trgt_unconn_ll->target.unconnected.cmdread, pull);
 277         cor_databuf_ackread(trgt_unconn_ll);
 278
 279         trgt_unconn_ll->target.unconnected.cmdread += pull;
 280 }
 281
 282 static void cor_read_discard(struct cor_conn *trgt_unconn_ll)
 283 {
 284         BUG_ON(trgt_unconn_ll->target.unconnected.paramlen_read == 0);
 285
 286         while (trgt_unconn_ll->target.unconnected.paramlen <
 287                         trgt_unconn_ll->target.unconnected.cmdread &&
 288                         trgt_unconn_ll->data_buf.read_remaining > 0) {
 289                 char buf[1];
 290                 cor_databuf_pull(trgt_unconn_ll, buf, 1);
 291                 cor_databuf_ackread(trgt_unconn_ll);
 292
 293                 trgt_unconn_ll->target.unconnected.cmdread++;
 294         }
 295 }
 296
 297 #define RC_READ_HDR_FINISHED 0
 298 #define RC_READ_HDR_INCOMPLETE 1
 299 static int cor_read_hdr(struct cor_conn *trgt_unconn_ll)
 300 {
 301         BUG_ON(trgt_unconn_ll->target.unconnected.cmdparams != 0);
 302
 303         while (1) {
 304                 int rc;
 305                 if (trgt_unconn_ll->target.unconnected.paramlen_read != 0)
 306                         return RC_READ_HDR_FINISHED;
 307                 else if (trgt_unconn_ll->data_buf.read_remaining == 0)
 308                         return RC_READ_HDR_INCOMPLETE;
 309
 310                 BUG_ON(trgt_unconn_ll->target.unconnected.cmdread >= 6);
 311
 312                 if (trgt_unconn_ll->target.unconnected.cmdread < 2) {
 313                         char buf[1];
 314                         cor_databuf_pull(trgt_unconn_ll, buf, 1);
 315                         trgt_unconn_ll->target.unconnected.cmd <<= 8;
 316                         trgt_unconn_ll->target.unconnected.cmd += buf[0];
 317                         trgt_unconn_ll->target.unconnected.cmdread += 1;
 318                         continue;
 319                 }
 320
 321                 cor_databuf_pull(trgt_unconn_ll,
 322                                 trgt_unconn_ll->target.unconnected.paramlen_buf +
 323                                 trgt_unconn_ll->target.unconnected.cmdread - 2,
 324                                 1);
 325                 cor_databuf_ackread(trgt_unconn_ll);
 326                 trgt_unconn_ll->target.unconnected.cmdread += 1;
 327
 328                 rc = cor_decode_len(
 329                                 trgt_unconn_ll->target.unconnected.paramlen_buf,
 330                                 trgt_unconn_ll->target.unconnected.cmdread - 2,
 331                                 &(trgt_unconn_ll->target.unconnected.paramlen));
 332
 333                 if (rc > 0) {
 334                         trgt_unconn_ll->target.unconnected.paramlen_read = 1;
 335                         trgt_unconn_ll->target.unconnected.cmdread = 0;
 336                         return RC_READ_HDR_FINISHED;
 337                 }
 338         }
 339 }
 340
 341 #define RC_PC_FINISHED 0
 342 #define RC_PC_OUT_OF_BUFSPACE 1
 343 #define RC_PC_INCOMPLETEREAD 2
 344 static int _cor_proc_cpacket(struct cor_conn *trgt_unconn_ll, int *reset_needed)
 345 {
 346         int rc;
 347
 348         if (cor_cpacket_write_allowed(trgt_unconn_ll->reversedir) == 0)
 349                 return RC_PC_OUT_OF_BUFSPACE;
 350
 351         if (trgt_unconn_ll->target.unconnected.paramlen_read != 0)
 352                 goto hdrdone;
 353
 354         rc = cor_read_hdr(trgt_unconn_ll);
 355         if (rc == RC_READ_HDR_INCOMPLETE) {
 356                 return RC_PC_INCOMPLETEREAD;
 357         } else if (rc == RC_READ_HDR_FINISHED) {
 358                 trgt_unconn_ll->target.unconnected.paramlen_read = 1;
 359
 360                 if (trgt_unconn_ll->target.unconnected.paramlen >
 361                                 MAX_CONN_CMD_LEN) {
 362                         /* command too long */
 363                         cor_send_resp_failed(trgt_unconn_ll,
 364                                         CDR_EXECFAILED_INVALID_COMMAND,
 365                                         reset_needed);
 366                 }
 367         } else {
 368                 BUG();
 369         }
 370
 371 hdrdone:
 372         if (trgt_unconn_ll->target.unconnected.paramlen >
 373                         MAX_CONN_CMD_LEN) {
 374                 cor_read_discard(trgt_unconn_ll);
 375                 return RC_PC_INCOMPLETEREAD;
 376         }
 377
 378         if (trgt_unconn_ll->target.unconnected.cmdparams == 0) {
 379                 trgt_unconn_ll->target.unconnected.cmdparams = kmalloc(
 380                                 trgt_unconn_ll->target.unconnected.paramlen,
 381                                 GFP_ATOMIC);
 382                 if (trgt_unconn_ll->target.unconnected.cmdparams == 0) {
 383                         *reset_needed = 1;
 384                         return RC_PC_INCOMPLETEREAD;
 385                 }
 386         }
 387
 388         cor_read_cmd(trgt_unconn_ll);
 389
 390         BUG_ON(trgt_unconn_ll->target.unconnected.cmdread >
 391                         trgt_unconn_ll->target.unconnected.paramlen);
 392
 393         if (trgt_unconn_ll->target.unconnected.cmdread <
 394                         trgt_unconn_ll->target.unconnected.paramlen)
 395                 return RC_PC_INCOMPLETEREAD;
 396
 397         cor_proc_cmd(trgt_unconn_ll, reset_needed);
 398
 399         return RC_PC_FINISHED;
 400 }
 401
 402 void cor_proc_cpacket(struct cor_conn *trgt_unconn_l)
 403 {
 404         int reset_needed = 0;
 405
 406         if (unlikely(trgt_unconn_l->isreset != 0))
 407                 return;
 408
 409         BUG_ON(trgt_unconn_l->targettype != TARGET_UNCONNECTED);
 410
 411         BUG_ON(trgt_unconn_l->is_client == 0);
 412         spin_lock_bh(&(trgt_unconn_l->reversedir->rcv_lock));
 413
 414         while (1) {
 415                 int rc = _cor_proc_cpacket(trgt_unconn_l, &reset_needed);
 416
 417                 BUG_ON(rc != RC_PC_FINISHED &&
 418                                 rc != RC_PC_OUT_OF_BUFSPACE &&
 419                                 rc != RC_PC_INCOMPLETEREAD);
 420
 421                 if (trgt_unconn_l->targettype == TARGET_UNCONNECTED) {
 422                         if (trgt_unconn_l->flush != 0 &&
 423                                         trgt_unconn_l->data_buf.read_remaining == 0)
 424                                 trgt_unconn_l->reversedir->flush = 1;
 425                         else
 426                                 trgt_unconn_l->reversedir->flush = 0;
 427
 428                         cor_flush_buf(trgt_unconn_l->reversedir);
 429
 430                         if (rc == RC_PC_OUT_OF_BUFSPACE ||
 431                                         rc == RC_PC_INCOMPLETEREAD)
 432                                 break;
 433                 } else {
 434                         BUG_ON(rc != RC_PC_FINISHED);
 435
 436                         if (trgt_unconn_l->targettype == TARGET_SOCK ||
 437                                         trgt_unconn_l->is_highlatency == 0 || (
 438                                         trgt_unconn_l->flush != 0 &&
 439                                         trgt_unconn_l->data_buf.read_remaining == 0))
 440                                 trgt_unconn_l->reversedir->flush = 1;
 441                         else
 442                                 trgt_unconn_l->reversedir->flush = 0;
 443
 444                         cor_flush_buf(trgt_unconn_l->reversedir);
 445                         cor_flush_buf(trgt_unconn_l);
 446                         break;
 447                 }
 448
 449                 if (reset_needed != 0)
 450                         cor_reset_conn_locked(trgt_unconn_l);
 451         }
 452
 453         spin_unlock_bh(&(trgt_unconn_l->reversedir->rcv_lock));
 454 }
 455
 456 MODULE_LICENSE("GPL");