The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 1 | /* Copyright (C) 2007-2008 The Android Open Source Project |
| 2 | ** |
| 3 | ** This software is licensed under the terms of the GNU General Public |
| 4 | ** License version 2, as published by the Free Software Foundation, and |
| 5 | ** may be copied, distributed, and modified under those terms. |
| 6 | ** |
| 7 | ** This program is distributed in the hope that it will be useful, |
| 8 | ** but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 10 | ** GNU General Public License for more details. |
| 11 | */ |
| 12 | #include "qemu-char.h" |
| 13 | #include "cbuffer.h" |
| 14 | #include "qemu_debug.h" |
| 15 | |
| 16 | #define xxDEBUG |
| 17 | |
| 18 | #ifdef DEBUG |
| 19 | # include <stdio.h> |
| 20 | # define D(...) ( fprintf( stderr, __VA_ARGS__ ), fprintf(stderr, "\n") ) |
| 21 | #else |
| 22 | # define D(...) ((void)0) |
| 23 | #endif |
| 24 | |
| 25 | /* we want to implement a bi-directionnal communication channel |
| 26 | * between two QEMU character drivers that merge well into the |
| 27 | * QEMU event loop. |
| 28 | * |
| 29 | * each half of the channel has its own object and buffer, and |
| 30 | * we implement communication through charpipe_poll() which |
| 31 | * must be called by the main event loop after its call to select() |
| 32 | * |
| 33 | */ |
| 34 | |
| 35 | #define BIP_BUFFER_SIZE 512 |
| 36 | |
| 37 | typedef struct BipBuffer { |
| 38 | struct BipBuffer* next; |
| 39 | CBuffer cb[1]; |
| 40 | char buff[ BIP_BUFFER_SIZE ]; |
| 41 | } BipBuffer; |
| 42 | |
| 43 | static BipBuffer* _free_bip_buffers; |
| 44 | |
| 45 | static BipBuffer* |
| 46 | bip_buffer_alloc( void ) |
| 47 | { |
| 48 | BipBuffer* bip = _free_bip_buffers; |
| 49 | if (bip != NULL) { |
| 50 | _free_bip_buffers = bip->next; |
| 51 | } else { |
| 52 | bip = malloc( sizeof(*bip) ); |
| 53 | if (bip == NULL) { |
| 54 | derror( "%s: not enough memory", __FUNCTION__ ); |
| 55 | exit(1); |
| 56 | } |
| 57 | } |
| 58 | bip->next = NULL; |
| 59 | cbuffer_reset( bip->cb, bip->buff, sizeof(bip->buff) ); |
| 60 | return bip; |
| 61 | } |
| 62 | |
| 63 | static void |
| 64 | bip_buffer_free( BipBuffer* bip ) |
| 65 | { |
| 66 | bip->next = _free_bip_buffers; |
| 67 | _free_bip_buffers = bip; |
| 68 | } |
| 69 | |
| 70 | /* this models each half of the charpipe */ |
| 71 | typedef struct CharPipeHalf { |
| 72 | CharDriverState cs[1]; |
| 73 | BipBuffer* bip_first; |
| 74 | BipBuffer* bip_last; |
| 75 | struct CharPipeHalf* peer; /* NULL if closed */ |
| 76 | } CharPipeHalf; |
| 77 | |
| 78 | |
| 79 | |
| 80 | static void |
| 81 | charpipehalf_close( CharDriverState* cs ) |
| 82 | { |
| 83 | CharPipeHalf* ph = cs->opaque; |
| 84 | |
| 85 | while (ph->bip_first) { |
| 86 | BipBuffer* bip = ph->bip_first; |
| 87 | ph->bip_first = bip->next; |
| 88 | bip_buffer_free(bip); |
| 89 | } |
| 90 | ph->bip_last = NULL; |
| 91 | ph->peer = NULL; |
| 92 | } |
| 93 | |
| 94 | |
| 95 | static int |
| 96 | charpipehalf_write( CharDriverState* cs, const uint8_t* buf, int len ) |
| 97 | { |
| 98 | CharPipeHalf* ph = cs->opaque; |
| 99 | CharPipeHalf* peer = ph->peer; |
| 100 | BipBuffer* bip = ph->bip_last; |
| 101 | int ret = 0; |
| 102 | |
| 103 | D("%s: writing %d bytes to %p: '%s'", __FUNCTION__, |
| 104 | len, ph, quote_bytes( buf, len )); |
| 105 | |
| 106 | if (bip == NULL && peer != NULL && peer->cs->chr_read != NULL) { |
| 107 | /* no buffered data, try to write directly to the peer */ |
| 108 | while (len > 0) { |
| 109 | int size; |
| 110 | |
| 111 | if (peer->cs->chr_can_read) { |
| 112 | size = qemu_chr_can_read( peer->cs ); |
| 113 | if (size == 0) |
| 114 | break; |
| 115 | |
| 116 | if (size > len) |
| 117 | size = len; |
| 118 | } else |
| 119 | size = len; |
| 120 | |
| 121 | qemu_chr_read( peer->cs, (uint8_t*)buf, size ); |
| 122 | buf += size; |
| 123 | len -= size; |
| 124 | ret += size; |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | if (len == 0) |
| 129 | return ret; |
| 130 | |
| 131 | /* buffer the remaining data */ |
| 132 | if (bip == NULL) { |
| 133 | bip = bip_buffer_alloc(); |
| 134 | ph->bip_first = ph->bip_last = bip; |
| 135 | } |
| 136 | |
| 137 | while (len > 0) { |
| 138 | int len2 = cbuffer_write( bip->cb, buf, len ); |
| 139 | |
| 140 | buf += len2; |
| 141 | ret += len2; |
| 142 | len -= len2; |
| 143 | if (len == 0) |
| 144 | break; |
| 145 | |
| 146 | /* ok, we need another buffer */ |
| 147 | ph->bip_last = bip_buffer_alloc(); |
| 148 | bip->next = ph->bip_last; |
| 149 | bip = ph->bip_last; |
| 150 | } |
| 151 | return ret; |
| 152 | } |
| 153 | |
| 154 | |
| 155 | static void |
| 156 | charpipehalf_poll( CharPipeHalf* ph ) |
| 157 | { |
| 158 | CharPipeHalf* peer = ph->peer; |
| 159 | int size; |
| 160 | |
| 161 | if (peer == NULL || peer->cs->chr_read == NULL) |
| 162 | return; |
| 163 | |
| 164 | while (1) { |
| 165 | BipBuffer* bip = ph->bip_first; |
| 166 | uint8_t* base; |
| 167 | int avail; |
| 168 | |
| 169 | if (bip == NULL) |
| 170 | break; |
| 171 | |
| 172 | size = cbuffer_read_avail(bip->cb); |
| 173 | if (size == 0) { |
| 174 | ph->bip_first = bip->next; |
| 175 | if (ph->bip_first == NULL) |
| 176 | ph->bip_last = NULL; |
| 177 | bip_buffer_free(bip); |
| 178 | continue; |
| 179 | } |
| 180 | |
| 181 | if (ph->cs->chr_can_read) { |
| 182 | int size2 = qemu_chr_can_read(peer->cs); |
| 183 | |
| 184 | if (size2 == 0) |
| 185 | break; |
| 186 | |
| 187 | if (size > size2) |
| 188 | size = size2; |
| 189 | } |
| 190 | |
| 191 | avail = cbuffer_read_peek( bip->cb, &base ); |
| 192 | if (avail > size) |
| 193 | avail = size; |
| 194 | D("%s: sending %d bytes from %p: '%s'", __FUNCTION__, |
| 195 | avail, ph, quote_bytes( base, avail )); |
| 196 | |
| 197 | qemu_chr_read( peer->cs, base, avail ); |
| 198 | cbuffer_read_step( bip->cb, avail ); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | |
| 203 | static void |
| 204 | charpipehalf_init( CharPipeHalf* ph, CharPipeHalf* peer ) |
| 205 | { |
| 206 | CharDriverState* cs = ph->cs; |
| 207 | |
| 208 | ph->bip_first = NULL; |
| 209 | ph->bip_last = NULL; |
| 210 | ph->peer = peer; |
| 211 | |
| 212 | cs->chr_write = charpipehalf_write; |
| 213 | cs->chr_ioctl = NULL; |
| 214 | cs->chr_send_event = NULL; |
| 215 | cs->chr_close = charpipehalf_close; |
| 216 | cs->opaque = ph; |
| 217 | } |
| 218 | |
| 219 | |
| 220 | typedef struct CharPipeState { |
| 221 | CharPipeHalf a[1]; |
| 222 | CharPipeHalf b[1]; |
| 223 | } CharPipeState; |
| 224 | |
| 225 | |
| 226 | |
| 227 | #define MAX_CHAR_PIPES 8 |
| 228 | |
| 229 | static CharPipeState _s_charpipes[ MAX_CHAR_PIPES ]; |
| 230 | |
| 231 | int |
| 232 | qemu_chr_open_charpipe( CharDriverState* *pfirst, CharDriverState* *psecond ) |
| 233 | { |
| 234 | CharPipeState* cp = _s_charpipes; |
| 235 | CharPipeState* cp_end = cp + MAX_CHAR_PIPES; |
| 236 | |
| 237 | for ( ; cp < cp_end; cp++ ) { |
| 238 | if ( cp->a->peer == NULL && cp->b->peer == NULL ) |
| 239 | break; |
| 240 | } |
| 241 | |
| 242 | if (cp == cp_end) { /* can't allocate one */ |
| 243 | *pfirst = NULL; |
| 244 | *psecond = NULL; |
| 245 | return -1; |
| 246 | } |
| 247 | |
| 248 | charpipehalf_init( cp->a, cp->b ); |
| 249 | charpipehalf_init( cp->b, cp->a ); |
| 250 | |
| 251 | *pfirst = cp->a->cs; |
| 252 | *psecond = cp->b->cs; |
| 253 | return 0; |
| 254 | } |
| 255 | |
David Turner | 4735694 | 2009-04-05 14:23:06 -0700 | [diff] [blame] | 256 | /** This models a charbuffer, an object used to buffer |
| 257 | ** the data that is sent to a given endpoint CharDriverState |
| 258 | ** object. |
| 259 | ** |
| 260 | ** On the other hand, any can_read() / read() request performed |
| 261 | ** by the endpoint will be passed to the CharBuffer's corresponding |
| 262 | ** handlers. |
| 263 | **/ |
| 264 | |
| 265 | typedef struct CharBuffer { |
| 266 | CharDriverState cs[1]; |
| 267 | BipBuffer* bip_first; |
| 268 | BipBuffer* bip_last; |
| 269 | CharDriverState* endpoint; /* NULL if closed */ |
| 270 | char closing; |
| 271 | } CharBuffer; |
| 272 | |
| 273 | |
| 274 | static void |
| 275 | charbuffer_close( CharDriverState* cs ) |
| 276 | { |
| 277 | CharBuffer* cbuf = cs->opaque; |
| 278 | |
| 279 | while (cbuf->bip_first) { |
| 280 | BipBuffer* bip = cbuf->bip_first; |
| 281 | cbuf->bip_first = bip->next; |
| 282 | bip_buffer_free(bip); |
| 283 | } |
| 284 | cbuf->bip_last = NULL; |
| 285 | cbuf->endpoint = NULL; |
| 286 | |
| 287 | if (cbuf->endpoint != NULL) { |
| 288 | qemu_chr_close(cbuf->endpoint); |
| 289 | cbuf->endpoint = NULL; |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | static int |
| 294 | charbuffer_write( CharDriverState* cs, const uint8_t* buf, int len ) |
| 295 | { |
| 296 | CharBuffer* cbuf = cs->opaque; |
| 297 | CharDriverState* peer = cbuf->endpoint; |
| 298 | BipBuffer* bip = cbuf->bip_last; |
| 299 | int ret = 0; |
| 300 | |
| 301 | D("%s: writing %d bytes to %p: '%s'", __FUNCTION__, |
| 302 | len, cbuf, quote_bytes( buf, len )); |
| 303 | |
| 304 | if (bip == NULL && peer != NULL) { |
| 305 | /* no buffered data, try to write directly to the peer */ |
| 306 | int size = qemu_chr_write(peer, buf, len); |
| 307 | |
| 308 | if (size < 0) /* just to be safe */ |
| 309 | size = 0; |
| 310 | else if (size > len) |
| 311 | size = len; |
| 312 | |
| 313 | buf += size; |
| 314 | ret += size; |
| 315 | len -= size; |
| 316 | } |
| 317 | |
| 318 | if (len == 0) |
| 319 | return ret; |
| 320 | |
| 321 | /* buffer the remaining data */ |
| 322 | if (bip == NULL) { |
| 323 | bip = bip_buffer_alloc(); |
| 324 | cbuf->bip_first = cbuf->bip_last = bip; |
| 325 | } |
| 326 | |
| 327 | while (len > 0) { |
| 328 | int len2 = cbuffer_write( bip->cb, buf, len ); |
| 329 | |
| 330 | buf += len2; |
| 331 | ret += len2; |
| 332 | len -= len2; |
| 333 | if (len == 0) |
| 334 | break; |
| 335 | |
| 336 | /* ok, we need another buffer */ |
| 337 | cbuf->bip_last = bip_buffer_alloc(); |
| 338 | bip->next = cbuf->bip_last; |
| 339 | bip = cbuf->bip_last; |
| 340 | } |
| 341 | return ret; |
| 342 | } |
| 343 | |
| 344 | |
| 345 | static void |
| 346 | charbuffer_poll( CharBuffer* cbuf ) |
| 347 | { |
| 348 | CharDriverState* peer = cbuf->endpoint; |
| 349 | |
| 350 | if (peer == NULL) |
| 351 | return; |
| 352 | |
| 353 | while (1) { |
| 354 | BipBuffer* bip = cbuf->bip_first; |
| 355 | uint8_t* base; |
| 356 | int avail; |
| 357 | int size; |
| 358 | |
| 359 | if (bip == NULL) |
| 360 | break; |
| 361 | |
| 362 | avail = cbuffer_read_peek( bip->cb, &base ); |
| 363 | if (avail == 0) { |
| 364 | cbuf->bip_first = bip->next; |
| 365 | if (cbuf->bip_first == NULL) |
| 366 | cbuf->bip_last = NULL; |
| 367 | bip_buffer_free(bip); |
| 368 | continue; |
| 369 | } |
| 370 | |
| 371 | size = qemu_chr_write( peer, base, avail ); |
| 372 | |
| 373 | if (size < 0) /* just to be safe */ |
| 374 | size = 0; |
| 375 | else if (size > avail) |
| 376 | size = avail; |
| 377 | |
| 378 | cbuffer_read_step( bip->cb, size ); |
| 379 | |
| 380 | if (size < avail) |
| 381 | break; |
| 382 | } |
| 383 | } |
| 384 | |
| 385 | |
| 386 | static void |
| 387 | charbuffer_update_handlers( CharDriverState* cs ) |
| 388 | { |
| 389 | CharBuffer* cbuf = cs->opaque; |
| 390 | |
| 391 | qemu_chr_add_handlers( cbuf->endpoint, |
| 392 | cs->chr_can_read, |
| 393 | cs->chr_read, |
| 394 | cs->chr_event, |
| 395 | cs->handler_opaque ); |
| 396 | } |
| 397 | |
| 398 | |
| 399 | static void |
| 400 | charbuffer_init( CharBuffer* cbuf, CharDriverState* endpoint ) |
| 401 | { |
| 402 | CharDriverState* cs = cbuf->cs; |
| 403 | |
| 404 | cbuf->bip_first = NULL; |
| 405 | cbuf->bip_last = NULL; |
| 406 | cbuf->endpoint = endpoint; |
| 407 | |
| 408 | cs->chr_write = charbuffer_write; |
| 409 | cs->chr_ioctl = NULL; |
| 410 | cs->chr_send_event = NULL; |
| 411 | cs->chr_close = charbuffer_close; |
| 412 | cs->chr_update_read_handler = charbuffer_update_handlers; |
| 413 | cs->opaque = cbuf; |
| 414 | } |
| 415 | |
| 416 | #define MAX_CHAR_BUFFERS 8 |
| 417 | |
| 418 | static CharBuffer _s_charbuffers[ MAX_CHAR_BUFFERS ]; |
| 419 | |
| 420 | CharDriverState* |
| 421 | qemu_chr_open_buffer( CharDriverState* endpoint ) |
| 422 | { |
| 423 | CharBuffer* cbuf = _s_charbuffers; |
| 424 | CharBuffer* cbuf_end = cbuf + MAX_CHAR_BUFFERS; |
| 425 | |
| 426 | if (endpoint == NULL) |
| 427 | return NULL; |
| 428 | |
| 429 | for ( ; cbuf < cbuf_end; cbuf++ ) { |
| 430 | if (cbuf->endpoint == NULL) |
| 431 | break; |
| 432 | } |
| 433 | |
| 434 | if (cbuf == cbuf_end) |
| 435 | return NULL; |
| 436 | |
| 437 | charbuffer_init(cbuf, endpoint); |
| 438 | return cbuf->cs; |
| 439 | } |
| 440 | |
| 441 | |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 442 | void |
| 443 | charpipe_poll( void ) |
| 444 | { |
| 445 | CharPipeState* cp = _s_charpipes; |
| 446 | CharPipeState* cp_end = cp + MAX_CHAR_PIPES; |
| 447 | |
David Turner | 4735694 | 2009-04-05 14:23:06 -0700 | [diff] [blame] | 448 | CharBuffer* cb = _s_charbuffers; |
| 449 | CharBuffer* cb_end = cb + MAX_CHAR_BUFFERS; |
| 450 | |
| 451 | /* poll the charpipes */ |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 452 | for ( ; cp < cp_end; cp++ ) { |
| 453 | CharPipeHalf* half; |
| 454 | |
| 455 | half = cp->a; |
| 456 | if (half->peer != NULL) |
| 457 | charpipehalf_poll(half); |
| 458 | |
| 459 | half = cp->b; |
| 460 | if (half->peer != NULL) |
| 461 | charpipehalf_poll(half); |
| 462 | } |
David Turner | 4735694 | 2009-04-05 14:23:06 -0700 | [diff] [blame] | 463 | |
| 464 | /* poll the charbuffers */ |
| 465 | for ( ; cb < cb_end; cb++ ) { |
| 466 | if (cb->endpoint != NULL) |
| 467 | charbuffer_poll(cb); |
| 468 | } |
The Android Open Source Project | 8b23a6c | 2009-03-03 19:30:32 -0800 | [diff] [blame] | 469 | } |