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(cor_get_conn_reversedir(trgt_unconn_ll),
  97                         (char *) &respcode, 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(cor_get_conn_reversedir(trgt_unconn_ll),
 110                         msg, 3, 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(cor_get_conn_reversedir(trgt_unconn_ll),
 125                         hdr, len_len + 1, reset_needed);
 126         cor_receive_cpacketresp(cor_get_conn_reversedir(trgt_unconn_ll),
 127                         buf, len, reset_needed);
 128 }
 129
 130 static __u32 cor_list_l4_protocols(char *buf, __u32 buflen)
 131 {
 132         if (unlikely(buflen < 2)) {
 133                 BUG();
 134                 return 0;
 135         }
 136
 137         cor_put_u16(buf, L4PROTO_STREAM);
 138         return 2;
 139 }
 140
 141 static int cor_proc_bindata(struct cor_conn *trgt_unconn_ll, __u16 cmd,
 142                 int *reset_needed)
 143 {
 144         __u32 len = 0;
 145         char *buf;
 146
 147         buf = kmalloc(CD_RESP_BIN_MAXSIZE, GFP_ATOMIC);
 148         if (unlikely(buf == 0)) {
 149                 cor_send_resp_failed(trgt_unconn_ll,
 150                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES,
 151                                 reset_needed);
 152                 return 1;
 153         }
 154
 155         cor_send_resp_ok(trgt_unconn_ll, reset_needed);
 156
 157         if (cmd == CD_LIST_NEIGH) {
 158                 len = cor_generate_neigh_list(buf, CD_RESP_BIN_MAXSIZE);
 159         } else if (cmd == CD_LIST_SERVICES) {
 160                 len = cor_list_services(buf, CD_RESP_BIN_MAXSIZE);
 161         } else if (cmd == CD_LIST_L4PROTOCOLS) {
 162                 len = cor_list_l4_protocols(buf, CD_RESP_BIN_MAXSIZE);
 163         } else {
 164                 BUG();
 165         }
 166         cor_send_resp_bin(trgt_unconn_ll, buf, len, reset_needed);
 167         kfree(buf);
 168         return 0;
 169 }
 170
 171 static int cor_proc_connect_port(struct cor_conn *trgt_unconn_ll,
 172                 int *reset_needed)
 173 {
 174         __u16 proto;
 175         __be32 port;
 176         int rc;
 177
 178         if (unlikely(trgt_unconn_ll->target.unconnected.paramlen < 6)) {
 179                 /* command too short */
 180                 cor_send_resp_failed(trgt_unconn_ll,
 181                                 CDR_EXECFAILED_INVALID_COMMAND, reset_needed);
 182                 return 1;
 183         }
 184
 185         proto = cor_parse_u16(trgt_unconn_ll->target.unconnected.cmdparams);
 186         port = cor_parse_be32(trgt_unconn_ll->target.unconnected.cmdparams + 2);
 187
 188         if (proto != L4PROTO_STREAM) {
 189                 cor_send_resp_failed(trgt_unconn_ll,
 190                                 CDR_EXECFAILED_UNKNOWN_L4PROTOCOL,
 191                                 reset_needed);
 192                 return 1;
 193         }
 194
 195         rc = cor_connect_port(trgt_unconn_ll, port);
 196
 197         if (rc == 0) {
 198                 cor_send_resp_ok(trgt_unconn_ll, reset_needed);
 199                 return 0;
 200         } else if (rc == 2) {
 201                 cor_send_resp_failed(trgt_unconn_ll,
 202                                 CDR_EXECFAILED_PORTCLOSED, reset_needed);
 203         } else if (rc == 3) {
 204                 cor_send_resp_failed(trgt_unconn_ll,
 205                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES,
 206                                 reset_needed);
 207         } else {
 208                 BUG();
 209         }
 210         return 1;
 211 }
 212
 213 static int cor_proc_connect_nb(struct cor_conn *trgt_unconn_ll,
 214                 int *reset_needed)
 215 {
 216         char *addr = trgt_unconn_ll->target.unconnected.cmdparams;
 217         __u32 addrlen = trgt_unconn_ll->target.unconnected.paramlen;
 218
 219         int rc;
 220
 221         if (unlikely(addrlen > 65535)) {
 222                 cor_send_resp_failed(trgt_unconn_ll,
 223                                 CDR_EXECFAILED_NB_DOESNTEXIST, reset_needed);
 224                 return 1;
 225         }
 226
 227         rc = cor_connect_neigh(trgt_unconn_ll, addr, (__u16) addrlen);
 228
 229         if (rc == 0) {
 230                 cor_send_resp_ok(trgt_unconn_ll, reset_needed);
 231                 return 0;
 232         } else if (rc == 3) {
 233                 cor_send_resp_failed(trgt_unconn_ll,
 234                                 CDR_EXECFAILED_NB_DOESNTEXIST, reset_needed);
 235         } else if (rc == 4) {
 236                 cor_send_resp_failed(trgt_unconn_ll,
 237                                 CDR_EXECFAILED_TEMPORARILY_OUT_OF_RESSOURCES,
 238                                 reset_needed);
 239         } else {
 240                 BUG();
 241         }
 242         return 1;
 243 }
 244
 245 static void cor_proc_cmd(struct cor_conn *trgt_unconn_ll, int *reset_needed)
 246 {
 247         __u16 cmd = trgt_unconn_ll->target.unconnected.cmd;
 248         char *params = trgt_unconn_ll->target.unconnected.cmdparams;
 249         int discard_on_error = (cmd & CD_CONTINUE_ON_ERROR_FLAG) == 0;
 250         int rc;
 251
 252         cmd = cmd & (~CD_CONTINUE_ON_ERROR_FLAG);
 253
 254         BUG_ON(trgt_unconn_ll->target.unconnected.cmdparams == 0);
 255
 256         if (cmd == CD_CONNECT_NB) {
 257                 rc = cor_proc_connect_nb(trgt_unconn_ll, reset_needed);
 258         } else if (cmd == CD_CONNECT_PORT) {
 259                 rc = cor_proc_connect_port(trgt_unconn_ll, reset_needed);
 260         } else if (cmd == CD_LIST_NEIGH || cmd == CD_LIST_SERVICES ||
 261                         cmd == CD_LIST_L4PROTOCOLS) {
 262                 rc = cor_proc_bindata(trgt_unconn_ll, cmd, reset_needed);
 263         } else {
 264                 cor_send_resp_failed(trgt_unconn_ll,
 265                                 CDR_EXECFAILED_INVALID_COMMAND, reset_needed);
 266                 rc = 1;
 267         }
 268
 269         kfree(params);
 270
 271         if (trgt_unconn_ll->targettype == TARGET_UNCONNECTED) {
 272                 trgt_unconn_ll->target.unconnected.cmdparams = 0;
 273                 trgt_unconn_ll->target.unconnected.cmdread = 0;
 274                 trgt_unconn_ll->target.unconnected.paramlen_read = 0;
 275                 trgt_unconn_ll->target.unconnected.cmd = 0;
 276                 trgt_unconn_ll->target.unconnected.paramlen = 0;
 277
 278                 if (rc != 0 && discard_on_error) {
 279                         trgt_unconn_ll->targettype = TARGET_DISCARD;
 280                 }
 281         }
 282 }
 283
 284 static void cor_read_cmd(struct cor_conn *trgt_unconn_ll)
 285 {
 286         int pull;
 287
 288         pull = min(trgt_unconn_ll->target.unconnected.paramlen -
 289                         trgt_unconn_ll->target.unconnected.cmdread,
 290                         trgt_unconn_ll->data_buf.read_remaining);
 291
 292         BUG_ON(pull < 0);
 293         BUG_ON(trgt_unconn_ll->target.unconnected.cmdparams == 0);
 294
 295         if (pull == 0)
 296                 return;
 297
 298         cor_databuf_pull(trgt_unconn_ll,
 299                         trgt_unconn_ll->target.unconnected.cmdparams +
 300                         trgt_unconn_ll->target.unconnected.cmdread, pull);
 301         cor_databuf_ackread(trgt_unconn_ll);
 302
 303         trgt_unconn_ll->target.unconnected.cmdread += pull;
 304 }
 305
 306 static void cor_read_discard(struct cor_conn *trgt_unconn_ll)
 307 {
 308         BUG_ON(trgt_unconn_ll->target.unconnected.paramlen_read == 0);
 309
 310         while (trgt_unconn_ll->target.unconnected.paramlen <
 311                         trgt_unconn_ll->target.unconnected.cmdread &&
 312                         trgt_unconn_ll->data_buf.read_remaining > 0) {
 313                 char buf[1];
 314                 cor_databuf_pull(trgt_unconn_ll, buf, 1);
 315                 cor_databuf_ackread(trgt_unconn_ll);
 316
 317                 trgt_unconn_ll->target.unconnected.cmdread++;
 318         }
 319 }
 320
 321 #define RC_READ_HDR_FINISHED 0
 322 #define RC_READ_HDR_INCOMPLETE 1
 323 static int cor_read_hdr(struct cor_conn *trgt_unconn_ll)
 324 {
 325         BUG_ON(trgt_unconn_ll->target.unconnected.cmdparams != 0);
 326
 327         while (1) {
 328                 int rc;
 329                 if (trgt_unconn_ll->target.unconnected.paramlen_read != 0)
 330                         return RC_READ_HDR_FINISHED;
 331                 else if (trgt_unconn_ll->data_buf.read_remaining == 0)
 332                         return RC_READ_HDR_INCOMPLETE;
 333
 334                 BUG_ON(trgt_unconn_ll->target.unconnected.cmdread >= 6);
 335
 336                 if (trgt_unconn_ll->target.unconnected.cmdread < 2) {
 337                         char buf[1];
 338                         cor_databuf_pull(trgt_unconn_ll, buf, 1);
 339                         trgt_unconn_ll->target.unconnected.cmd <<= 8;
 340                         trgt_unconn_ll->target.unconnected.cmd += buf[0];
 341                         trgt_unconn_ll->target.unconnected.cmdread += 1;
 342                         continue;
 343                 }
 344
 345                 cor_databuf_pull(trgt_unconn_ll,
 346                                 trgt_unconn_ll->target.unconnected.paramlen_buf +
 347                                 trgt_unconn_ll->target.unconnected.cmdread - 2,
 348                                 1);
 349                 cor_databuf_ackread(trgt_unconn_ll);
 350                 trgt_unconn_ll->target.unconnected.cmdread += 1;
 351
 352                 rc = cor_decode_len(
 353                                 trgt_unconn_ll->target.unconnected.paramlen_buf,
 354                                 trgt_unconn_ll->target.unconnected.cmdread - 2,
 355                                 &(trgt_unconn_ll->target.unconnected.paramlen));
 356
 357                 if (rc > 0) {
 358                         trgt_unconn_ll->target.unconnected.paramlen_read = 1;
 359                         trgt_unconn_ll->target.unconnected.cmdread = 0;
 360                         return RC_READ_HDR_FINISHED;
 361                 }
 362         }
 363 }
 364
 365 #define RC_PC_FINISHED 0
 366 #define RC_PC_OUT_OF_BUFSPACE 1
 367 #define RC_PC_INCOMPLETEREAD 2
 368 static int _cor_proc_cpacket(struct cor_conn *trgt_unconn_ll, int *reset_needed)
 369 {
 370         int rc;
 371
 372         if (cor_conn_src_unconn_write_allowed(cor_get_conn_reversedir(
 373                         trgt_unconn_ll)) == 0)
 374                 return RC_PC_OUT_OF_BUFSPACE;
 375
 376         if (trgt_unconn_ll->target.unconnected.paramlen_read != 0)
 377                 goto hdrdone;
 378
 379         rc = cor_read_hdr(trgt_unconn_ll);
 380         if (rc == RC_READ_HDR_INCOMPLETE) {
 381                 return RC_PC_INCOMPLETEREAD;
 382         } else if (rc == RC_READ_HDR_FINISHED) {
 383                 trgt_unconn_ll->target.unconnected.paramlen_read = 1;
 384
 385                 if (trgt_unconn_ll->target.unconnected.paramlen >
 386                                 MAX_CONN_CMD_LEN) {
 387                         /* command too long */
 388                         cor_send_resp_failed(trgt_unconn_ll,
 389                                         CDR_EXECFAILED_INVALID_COMMAND,
 390                                         reset_needed);
 391                 }
 392         } else {
 393                 BUG();
 394         }
 395
 396 hdrdone:
 397         if (trgt_unconn_ll->target.unconnected.paramlen >
 398                         MAX_CONN_CMD_LEN) {
 399                 cor_read_discard(trgt_unconn_ll);
 400                 return RC_PC_INCOMPLETEREAD;
 401         }
 402
 403         if (trgt_unconn_ll->target.unconnected.cmdparams == 0) {
 404                 trgt_unconn_ll->target.unconnected.cmdparams = kmalloc(
 405                                 trgt_unconn_ll->target.unconnected.paramlen,
 406                                 GFP_ATOMIC);
 407                 if (trgt_unconn_ll->target.unconnected.cmdparams == 0) {
 408                         *reset_needed = 1;
 409                         return RC_PC_INCOMPLETEREAD;
 410                 }
 411         }
 412
 413         cor_read_cmd(trgt_unconn_ll);
 414
 415         BUG_ON(trgt_unconn_ll->target.unconnected.cmdread >
 416                         trgt_unconn_ll->target.unconnected.paramlen);
 417
 418         if (trgt_unconn_ll->target.unconnected.cmdread <
 419                         trgt_unconn_ll->target.unconnected.paramlen)
 420                 return RC_PC_INCOMPLETEREAD;
 421
 422         cor_proc_cmd(trgt_unconn_ll, reset_needed);
 423
 424         return RC_PC_FINISHED;
 425 }
 426
 427 void cor_proc_cpacket(struct cor_conn *trgt_unconn_l)
 428 {
 429         struct cor_conn *src_in = cor_get_conn_reversedir(trgt_unconn_l);
 430         int reset_needed = 0;
 431
 432         if (unlikely(trgt_unconn_l->isreset != 0))
 433                 return;
 434
 435         BUG_ON(trgt_unconn_l->targettype != TARGET_UNCONNECTED);
 436
 437         BUG_ON(trgt_unconn_l->is_client == 0);
 438         spin_lock_bh(&(src_in->rcv_lock));
 439
 440         while (1) {
 441                 int rc = _cor_proc_cpacket(trgt_unconn_l, &reset_needed);
 442
 443                 BUG_ON(rc != RC_PC_FINISHED &&
 444                                 rc != RC_PC_OUT_OF_BUFSPACE &&
 445                                 rc != RC_PC_INCOMPLETEREAD);
 446
 447                 if (trgt_unconn_l->targettype == TARGET_UNCONNECTED) {
 448                         if (trgt_unconn_l->flush != 0 &&
 449                                         trgt_unconn_l->data_buf.read_remaining == 0)
 450                                 src_in->flush = 1;
 451                         else
 452                                 src_in->flush = 0;
 453
 454                         cor_flush_buf(cor_get_conn_reversedir(trgt_unconn_l));
 455
 456                         if (rc == RC_PC_OUT_OF_BUFSPACE ||
 457                                         rc == RC_PC_INCOMPLETEREAD)
 458                                 break;
 459                 } else {
 460                         BUG_ON(rc != RC_PC_FINISHED);
 461
 462                         if (trgt_unconn_l->targettype == TARGET_SOCK ||
 463                                         trgt_unconn_l->is_highlatency == 0 ||
 464                                         LOWLATENCY_SEND_UNFLUSHED_DATA != 0 || (
 465                                         trgt_unconn_l->flush != 0 &&
 466                                         trgt_unconn_l->data_buf.read_remaining == 0))
 467                                 src_in->flush = 1;
 468                         else
 469                                 src_in->flush = 0;
 470
 471                         cor_flush_buf(src_in);
 472                         cor_flush_buf(trgt_unconn_l);
 473                         break;
 474                 }
 475
 476                 if (reset_needed != 0)
 477                         cor_reset_conn_locked(cor_get_conn_bidir(
 478                                         trgt_unconn_l));
 479         }
 480
 481         spin_unlock_bh(&(src_in->rcv_lock));
 482 }
 483
 484 MODULE_LICENSE("GPL");