| 1 | #define USER 1 |
| 2 | #include <stdio.h> |
| 3 | #include <sys/pk.p> |
| 4 | #include <sys/param.h> |
| 5 | #include <sys/pk.h> |
| 6 | #include <sys/buf.h> |
| 7 | #include <setjmp.h> |
| 8 | #include <signal.h> |
| 9 | |
| 10 | #define PKTIME 10 |
| 11 | int Errorrate; |
| 12 | int Conbad = 0; |
| 13 | int Ntimeout = 0; |
| 14 | #define CONBAD 5 |
| 15 | #define NTIMEOUT 50 |
| 16 | /* |
| 17 | * packet driver support routines |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | struct pack *pklines[NPLINES]; |
| 22 | |
| 23 | /* |
| 24 | * start initial synchronization. |
| 25 | */ |
| 26 | |
| 27 | struct pack * |
| 28 | pkopen(ifn, ofn) |
| 29 | int ifn, ofn; |
| 30 | { |
| 31 | struct pack *pk; |
| 32 | char **bp; |
| 33 | int i; |
| 34 | |
| 35 | if (++pkactive >= NPLINES) |
| 36 | return(NULL); |
| 37 | if ((pk = (struct pack *) malloc(sizeof (struct pack))) == NULL) |
| 38 | return(NULL); |
| 39 | pkzero((caddr_t) pk, sizeof (struct pack)); |
| 40 | pk->p_ifn = ifn; |
| 41 | pk->p_ofn = ofn; |
| 42 | pk->p_xsize = pk->p_rsize = PACKSIZE; |
| 43 | pk->p_rwindow = pk->p_swindow = WINDOWS; |
| 44 | /* allocate input windows */ |
| 45 | for (i = 0; i < pk->p_rwindow; i++) { |
| 46 | if ((bp = (char **) GETEPACK) == NULL) |
| 47 | break; |
| 48 | *bp = (char *) pk->p_ipool; |
| 49 | pk->p_ipool = bp; |
| 50 | } |
| 51 | if (i == 0) |
| 52 | return(NULL); |
| 53 | pk->p_rwindow = i; |
| 54 | |
| 55 | /* start synchronization */ |
| 56 | pk->p_msg = pk->p_rmsg = M_INITA; |
| 57 | for (i = 0; i < NPLINES; i++) { |
| 58 | if (pklines[i] == NULL) { |
| 59 | pklines[i] = pk; |
| 60 | break; |
| 61 | } |
| 62 | } |
| 63 | if (i >= NPLINES) |
| 64 | return(NULL); |
| 65 | pkoutput(pk); |
| 66 | |
| 67 | while ((pk->p_state & LIVE) == 0) { |
| 68 | PKGETPKT(pk); |
| 69 | } |
| 70 | |
| 71 | pkreset(pk); |
| 72 | return(pk); |
| 73 | } |
| 74 | |
| 75 | |
| 76 | /* |
| 77 | * input framing and block checking. |
| 78 | * frame layout for most devices is: |
| 79 | * |
| 80 | * S|K|X|Y|C|Z| ... data ... | |
| 81 | * |
| 82 | * where S == initial synch byte |
| 83 | * K == encoded frame size (indexes pksizes[]) |
| 84 | * X, Y == block check bytes |
| 85 | * C == control byte |
| 86 | * Z == XOR of header (K^X^Y^C) |
| 87 | * data == 0 or more data bytes |
| 88 | * |
| 89 | */ |
| 90 | |
| 91 | int pksizes[] = { |
| 92 | 1, 32, 64, 128, 256, 512, 1024, 2048, 4096, 1 |
| 93 | }; |
| 94 | |
| 95 | #define GETRIES 5 |
| 96 | /* |
| 97 | * Pseudo-dma byte collection. |
| 98 | */ |
| 99 | |
| 100 | pkgetpack(ipk) |
| 101 | struct pack *ipk; |
| 102 | { |
| 103 | int ret, k, tries; |
| 104 | register char *p; |
| 105 | struct pack *pk; |
| 106 | struct header *h; |
| 107 | unsigned short sum; |
| 108 | int ifn; |
| 109 | char **bp; |
| 110 | char hdchk; |
| 111 | |
| 112 | if (Conbad > CONBAD /* || Ntimeout > NTIMEOUT */) |
| 113 | pkfail(); |
| 114 | pk = PADDR; |
| 115 | ifn = pk->p_ifn; |
| 116 | |
| 117 | /* find HEADER */ |
| 118 | for (tries = 0; tries < GETRIES; ) { |
| 119 | p = (caddr_t) &pk->p_ihbuf; |
| 120 | if ((ret = pkcget(ifn, p, 1)) < 0) { |
| 121 | /* set up retransmit or REJ */ |
| 122 | tries++; |
| 123 | pk->p_msg |= pk->p_rmsg; |
| 124 | if (pk->p_msg == 0) |
| 125 | pk->p_msg |= M_RR; |
| 126 | if ((pk->p_state & LIVE) == LIVE) |
| 127 | pk->p_state |= RXMIT; |
| 128 | pkoutput(pk); |
| 129 | continue; |
| 130 | } |
| 131 | if (*p != SYN) |
| 132 | continue; |
| 133 | p++; |
| 134 | ret = pkcget(ifn, p, HDRSIZ - 1); |
| 135 | if (ret == -1) |
| 136 | continue; |
| 137 | break; |
| 138 | } |
| 139 | if (tries >= GETRIES) { |
| 140 | PKDEBUG(4, "tries = %d\n", tries); |
| 141 | pkfail(); |
| 142 | } |
| 143 | |
| 144 | h = (struct header * ) &pk->p_ihbuf; |
| 145 | p = (caddr_t) h; |
| 146 | hdchk = p[1] ^ p[2] ^ p[3] ^ p[4]; |
| 147 | p += 2; |
| 148 | sum = (unsigned) *p++ & 0377; |
| 149 | sum |= (unsigned) *p << 8; |
| 150 | h->sum = sum; |
| 151 | PKDEBUG(7, "rec h->cntl %o\n", (unsigned) h->cntl); |
| 152 | k = h->ksize; |
| 153 | if (hdchk != h->ccntl) { |
| 154 | /* bad header */ |
| 155 | PKDEBUG(7, "bad header %o,", hdchk); |
| 156 | PKDEBUG(7, "h->ccntl %o\n", h->ccntl); |
| 157 | Conbad++; |
| 158 | return; |
| 159 | } |
| 160 | if (k == 9) { |
| 161 | if (h->sum + h->cntl == CHECK) { |
| 162 | pkcntl(h->cntl, pk); |
| 163 | Conbad = 0; |
| 164 | PKDEBUG(7, "state - %o\n", pk->p_state); |
| 165 | } |
| 166 | else { |
| 167 | /* bad header */ |
| 168 | Conbad++; |
| 169 | PKDEBUG(7, "bad header %o\n", h->cntl); |
| 170 | pk->p_state |= BADFRAME; |
| 171 | } |
| 172 | return; |
| 173 | } |
| 174 | if (k && pksizes[k] == pk->p_rsize) { |
| 175 | pk->p_rpr = h->cntl & MOD8; |
| 176 | pksack(pk); |
| 177 | Conbad = 0; |
| 178 | bp = pk->p_ipool; |
| 179 | pk->p_ipool = (char **) *bp; |
| 180 | if (bp == NULL) { |
| 181 | PKDEBUG(7, "bp NULL %s\n", ""); |
| 182 | return; |
| 183 | } |
| 184 | } |
| 185 | else { |
| 186 | Conbad++; |
| 187 | return; |
| 188 | } |
| 189 | ret = pkcget(pk->p_ifn, (char *) bp, pk->p_rsize); |
| 190 | PKASSERT(ret != -1, "PKGETPKT CAN't READ %d", ret); |
| 191 | pkdata(h->cntl, h->sum, pk, (char *) bp); |
| 192 | return; |
| 193 | } |
| 194 | |
| 195 | |
| 196 | pkdata(c, sum, pk, bp) |
| 197 | char c; |
| 198 | short sum; |
| 199 | register struct pack *pk; |
| 200 | char **bp; |
| 201 | { |
| 202 | register x; |
| 203 | int t; |
| 204 | char m; |
| 205 | |
| 206 | if (pk->p_state & DRAINO || !(pk->p_state & LIVE)) { |
| 207 | pk->p_msg |= pk->p_rmsg; |
| 208 | pkoutput(pk); |
| 209 | goto drop; |
| 210 | } |
| 211 | t = next[pk->p_pr]; |
| 212 | for(x=pk->p_pr; x!=t; x = (x-1)&7) { |
| 213 | if (pk->p_is[x] == 0) |
| 214 | goto slot; |
| 215 | } |
| 216 | drop: |
| 217 | *bp = (char *)pk->p_ipool; |
| 218 | pk->p_ipool = bp; |
| 219 | return; |
| 220 | |
| 221 | slot: |
| 222 | m = mask[x]; |
| 223 | pk->p_imap |= m; |
| 224 | pk->p_is[x] = c; |
| 225 | pk->p_isum[x] = sum; |
| 226 | pk->p_ib[x] = (char *)bp; |
| 227 | return; |
| 228 | } |
| 229 | |
| 230 | |
| 231 | |
| 232 | /* |
| 233 | * setup input transfers |
| 234 | */ |
| 235 | pkrstart(pk) |
| 236 | {} |
| 237 | |
| 238 | /* |
| 239 | * Start transmission on output device associated with pk. |
| 240 | * For asynch devices (t_line==1) framing is |
| 241 | * imposed. For devices with framing and crc |
| 242 | * in the driver (t_line==2) the transfer is |
| 243 | * passed on to the driver. |
| 244 | */ |
| 245 | pkxstart(pk, cntl, x) |
| 246 | struct pack *pk; |
| 247 | char cntl; |
| 248 | register x; |
| 249 | { |
| 250 | register char *p; |
| 251 | int ret; |
| 252 | short checkword; |
| 253 | char hdchk; |
| 254 | |
| 255 | p = (caddr_t) &pk->p_ohbuf; |
| 256 | *p++ = SYN; |
| 257 | if (x < 0) { |
| 258 | *p++ = hdchk = 9; |
| 259 | checkword = cntl; |
| 260 | } |
| 261 | else { |
| 262 | *p++ = hdchk = pk->p_lpsize; |
| 263 | checkword = pk->p_osum[x] ^ (unsigned)(cntl&0377); |
| 264 | } |
| 265 | checkword = CHECK - checkword; |
| 266 | *p = checkword; |
| 267 | hdchk ^= *p++; |
| 268 | *p = checkword>>8; |
| 269 | hdchk ^= *p++; |
| 270 | *p = cntl; |
| 271 | hdchk ^= *p++; |
| 272 | *p = hdchk; |
| 273 | /* writes */ |
| 274 | PKDEBUG(7, "send %o\n", (unsigned) cntl); |
| 275 | p = (caddr_t) & pk->p_ohbuf; |
| 276 | if (x < 0) { |
| 277 | GENERROR(p, HDRSIZ); |
| 278 | ret = write(pk->p_ofn, p, HDRSIZ); |
| 279 | PKASSERT(ret == HDRSIZ, "PKXSTART ret %d", ret); |
| 280 | } |
| 281 | else { |
| 282 | char buf[PACKSIZE + HDRSIZ], *b; |
| 283 | int i; |
| 284 | for (i = 0, b = buf; i < HDRSIZ; i++) |
| 285 | *b++ = *p++; |
| 286 | for (i = 0, p = pk->p_ob[x]; i < pk->p_rsize; i++) |
| 287 | *b++ = *p++; |
| 288 | GENERROR(buf, pk->p_rsize + HDRSIZ); |
| 289 | ret = write(pk->p_ofn, buf, pk->p_rsize + HDRSIZ); |
| 290 | PKASSERT(ret == pk->p_rsize + HDRSIZ, |
| 291 | "PKXSTART ret %d", ret); |
| 292 | } |
| 293 | if (pk->p_msg) |
| 294 | pkoutput(pk); |
| 295 | return; |
| 296 | } |
| 297 | |
| 298 | |
| 299 | pkmove(p1, p2, count, flag) |
| 300 | char *p1, *p2; |
| 301 | int count, flag; |
| 302 | { |
| 303 | char *s, *d; |
| 304 | int i; |
| 305 | if (flag == B_WRITE) { |
| 306 | s = p2; |
| 307 | d = p1; |
| 308 | } |
| 309 | else { |
| 310 | s = p1; |
| 311 | d = p2; |
| 312 | } |
| 313 | for (i = 0; i < count; i++) |
| 314 | *d++ = *s++; |
| 315 | return; |
| 316 | } |
| 317 | |
| 318 | |
| 319 | /*** |
| 320 | * pkcget(fn, b, n) get n characters from input |
| 321 | * char *b; - buffer for characters |
| 322 | * int fn; - file descriptor |
| 323 | * int n; - requested number of characters |
| 324 | * |
| 325 | * return codes: |
| 326 | * n - number of characters returned |
| 327 | * 0 - end of file |
| 328 | */ |
| 329 | |
| 330 | jmp_buf Getjbuf; |
| 331 | cgalarm() { longjmp(Getjbuf, 1); } |
| 332 | |
| 333 | pkcget(fn, b, n) |
| 334 | int fn, n; |
| 335 | char *b; |
| 336 | { |
| 337 | int nchars, ret; |
| 338 | |
| 339 | if (setjmp(Getjbuf)) { |
| 340 | Ntimeout++; |
| 341 | PKDEBUG(4, "alarm %d\n", Ntimeout); |
| 342 | return(-1); |
| 343 | } |
| 344 | signal(SIGALRM, cgalarm); |
| 345 | |
| 346 | for (nchars = 0; nchars < n; nchars += ret) { |
| 347 | alarm(PKTIME); |
| 348 | ret = read(fn, b, n - nchars); |
| 349 | if (ret == 0) { |
| 350 | alarm(0); |
| 351 | return(-1); |
| 352 | } |
| 353 | PKASSERT(ret > 0, "PKCGET READ %d", ret); |
| 354 | b += ret; |
| 355 | } |
| 356 | alarm(0); |
| 357 | return(0); |
| 358 | } |
| 359 | |
| 360 | |
| 361 | generror(p, s) |
| 362 | char *p; |
| 363 | int s; |
| 364 | { |
| 365 | int r; |
| 366 | if (Errorrate != 0 && (rand() % Errorrate) == 0) { |
| 367 | r = rand() % s; |
| 368 | fprintf(stderr, "gen err at %o, (%o), ", r, (unsigned) *(p + r)); |
| 369 | *(p + r) += 1; |
| 370 | } |
| 371 | return; |
| 372 | } |
| 373 | |
| 374 | |