Eric Van Hensbergen | ace51c4 | 2008-10-13 20:40:27 -0500 | [diff] [blame^] | 1 | /* |
| 2 | * net/9p/protocol.c |
| 3 | * |
| 4 | * 9P Protocol Support Code |
| 5 | * |
| 6 | * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com> |
| 7 | * |
| 8 | * Base on code from Anthony Liguori <aliguori@us.ibm.com> |
| 9 | * Copyright (C) 2008 by IBM, Corp. |
| 10 | * |
| 11 | * This program is free software; you can redistribute it and/or modify |
| 12 | * it under the terms of the GNU General Public License version 2 |
| 13 | * as published by the Free Software Foundation. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program; if not, write to: |
| 22 | * Free Software Foundation |
| 23 | * 51 Franklin Street, Fifth Floor |
| 24 | * Boston, MA 02111-1301 USA |
| 25 | * |
| 26 | */ |
| 27 | |
| 28 | #include <linux/module.h> |
| 29 | #include <linux/errno.h> |
| 30 | #include <net/9p/9p.h> |
| 31 | #include <net/9p/client.h> |
| 32 | #include "protocol.h" |
| 33 | |
| 34 | #ifndef MIN |
| 35 | #define MIN(a, b) (((a) < (b)) ? (a) : (b)) |
| 36 | #endif |
| 37 | |
| 38 | #ifndef MAX |
| 39 | #define MAX(a, b) (((a) > (b)) ? (a) : (b)) |
| 40 | #endif |
| 41 | |
| 42 | #ifndef offset_of |
| 43 | #define offset_of(type, memb) \ |
| 44 | ((unsigned long)(&((type *)0)->memb)) |
| 45 | #endif |
| 46 | #ifndef container_of |
| 47 | #define container_of(obj, type, memb) \ |
| 48 | ((type *)(((char *)obj) - offset_of(type, memb))) |
| 49 | #endif |
| 50 | |
| 51 | static int |
| 52 | p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...); |
| 53 | |
| 54 | void p9stat_free(struct p9_wstat *stbuf) |
| 55 | { |
| 56 | kfree(stbuf->name); |
| 57 | kfree(stbuf->uid); |
| 58 | kfree(stbuf->gid); |
| 59 | kfree(stbuf->muid); |
| 60 | kfree(stbuf->extension); |
| 61 | } |
| 62 | EXPORT_SYMBOL(p9stat_free); |
| 63 | |
| 64 | static size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size) |
| 65 | { |
| 66 | size_t len = MIN(pdu->size - pdu->offset, size); |
| 67 | memcpy(data, &pdu->sdata[pdu->offset], len); |
| 68 | pdu->offset += len; |
| 69 | return size - len; |
| 70 | } |
| 71 | |
| 72 | static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size) |
| 73 | { |
| 74 | size_t len = MIN(pdu->capacity - pdu->size, size); |
| 75 | memcpy(&pdu->sdata[pdu->size], data, len); |
| 76 | pdu->size += len; |
| 77 | return size - len; |
| 78 | } |
| 79 | |
| 80 | /* |
| 81 | b - int8_t |
| 82 | w - int16_t |
| 83 | d - int32_t |
| 84 | q - int64_t |
| 85 | s - string |
| 86 | S - stat |
| 87 | Q - qid |
| 88 | D - data blob (int32_t size followed by void *, results are not freed) |
| 89 | T - array of strings (int16_t count, followed by strings) |
| 90 | R - array of qids (int16_t count, followed by qids) |
| 91 | ? - if optional = 1, continue parsing |
| 92 | */ |
| 93 | |
| 94 | static int |
| 95 | p9pdu_vreadf(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap) |
| 96 | { |
| 97 | const char *ptr; |
| 98 | int errcode = 0; |
| 99 | |
| 100 | for (ptr = fmt; *ptr; ptr++) { |
| 101 | switch (*ptr) { |
| 102 | case 'b':{ |
| 103 | int8_t *val = va_arg(ap, int8_t *); |
| 104 | if (pdu_read(pdu, val, sizeof(*val))) { |
| 105 | errcode = -EFAULT; |
| 106 | break; |
| 107 | } |
| 108 | } |
| 109 | break; |
| 110 | case 'w':{ |
| 111 | int16_t *val = va_arg(ap, int16_t *); |
| 112 | if (pdu_read(pdu, val, sizeof(*val))) { |
| 113 | errcode = -EFAULT; |
| 114 | break; |
| 115 | } |
| 116 | *val = cpu_to_le16(*val); |
| 117 | } |
| 118 | break; |
| 119 | case 'd':{ |
| 120 | int32_t *val = va_arg(ap, int32_t *); |
| 121 | if (pdu_read(pdu, val, sizeof(*val))) { |
| 122 | errcode = -EFAULT; |
| 123 | break; |
| 124 | } |
| 125 | *val = cpu_to_le32(*val); |
| 126 | } |
| 127 | break; |
| 128 | case 'q':{ |
| 129 | int64_t *val = va_arg(ap, int64_t *); |
| 130 | if (pdu_read(pdu, val, sizeof(*val))) { |
| 131 | errcode = -EFAULT; |
| 132 | break; |
| 133 | } |
| 134 | *val = cpu_to_le64(*val); |
| 135 | } |
| 136 | break; |
| 137 | case 's':{ |
| 138 | char **ptr = va_arg(ap, char **); |
| 139 | int16_t len; |
| 140 | int size; |
| 141 | |
| 142 | errcode = p9pdu_readf(pdu, optional, "w", &len); |
| 143 | if (errcode) |
| 144 | break; |
| 145 | |
| 146 | size = MAX(len, 0); |
| 147 | |
| 148 | *ptr = kmalloc(size + 1, GFP_KERNEL); |
| 149 | if (*ptr == NULL) { |
| 150 | errcode = -EFAULT; |
| 151 | break; |
| 152 | } |
| 153 | if (pdu_read(pdu, *ptr, size)) { |
| 154 | errcode = -EFAULT; |
| 155 | kfree(*ptr); |
| 156 | *ptr = NULL; |
| 157 | } else |
| 158 | (*ptr)[size] = 0; |
| 159 | } |
| 160 | break; |
| 161 | case 'Q':{ |
| 162 | struct p9_qid *qid = |
| 163 | va_arg(ap, struct p9_qid *); |
| 164 | |
| 165 | errcode = p9pdu_readf(pdu, optional, "bdq", |
| 166 | &qid->type, &qid->version, |
| 167 | &qid->path); |
| 168 | } |
| 169 | break; |
| 170 | case 'S':{ |
| 171 | struct p9_wstat *stbuf = |
| 172 | va_arg(ap, struct p9_wstat *); |
| 173 | |
| 174 | stbuf->extension = NULL; |
| 175 | stbuf->n_uid = stbuf->n_gid = stbuf->n_muid = |
| 176 | -1; |
| 177 | |
| 178 | errcode = |
| 179 | p9pdu_readf(pdu, optional, |
| 180 | "wwdQdddqssss?sddd", |
| 181 | &stbuf->size, &stbuf->type, |
| 182 | &stbuf->dev, &stbuf->qid, |
| 183 | &stbuf->mode, &stbuf->atime, |
| 184 | &stbuf->mtime, &stbuf->length, |
| 185 | &stbuf->name, &stbuf->uid, |
| 186 | &stbuf->gid, &stbuf->muid, |
| 187 | &stbuf->extension, |
| 188 | &stbuf->n_uid, &stbuf->n_gid, |
| 189 | &stbuf->n_muid); |
| 190 | if (errcode) |
| 191 | p9stat_free(stbuf); |
| 192 | } |
| 193 | break; |
| 194 | case 'D':{ |
| 195 | int32_t *count = va_arg(ap, int32_t *); |
| 196 | void **data = va_arg(ap, void **); |
| 197 | |
| 198 | errcode = |
| 199 | p9pdu_readf(pdu, optional, "d", count); |
| 200 | if (!errcode) { |
| 201 | *count = |
| 202 | MIN(*count, |
| 203 | pdu->size - pdu->offset); |
| 204 | *data = &pdu->sdata[pdu->offset]; |
| 205 | } |
| 206 | } |
| 207 | break; |
| 208 | case 'T':{ |
| 209 | int16_t *nwname = va_arg(ap, int16_t *); |
| 210 | char ***wnames = va_arg(ap, char ***); |
| 211 | |
| 212 | errcode = |
| 213 | p9pdu_readf(pdu, optional, "w", nwname); |
| 214 | if (!errcode) { |
| 215 | *wnames = |
| 216 | kmalloc(sizeof(char *) * *nwname, |
| 217 | GFP_KERNEL); |
| 218 | if (!*wnames) |
| 219 | errcode = -ENOMEM; |
| 220 | } |
| 221 | |
| 222 | if (!errcode) { |
| 223 | int i; |
| 224 | |
| 225 | for (i = 0; i < *nwname; i++) { |
| 226 | errcode = |
| 227 | p9pdu_readf(pdu, optional, |
| 228 | "s", |
| 229 | &(*wnames)[i]); |
| 230 | if (errcode) |
| 231 | break; |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | if (errcode) { |
| 236 | if (*wnames) { |
| 237 | int i; |
| 238 | |
| 239 | for (i = 0; i < *nwname; i++) |
| 240 | kfree((*wnames)[i]); |
| 241 | } |
| 242 | kfree(*wnames); |
| 243 | *wnames = NULL; |
| 244 | } |
| 245 | } |
| 246 | break; |
| 247 | case 'R':{ |
| 248 | int16_t *nwqid = va_arg(ap, int16_t *); |
| 249 | struct p9_qid **wqids = |
| 250 | va_arg(ap, struct p9_qid **); |
| 251 | |
| 252 | *wqids = NULL; |
| 253 | |
| 254 | errcode = |
| 255 | p9pdu_readf(pdu, optional, "w", nwqid); |
| 256 | if (!errcode) { |
| 257 | *wqids = |
| 258 | kmalloc(*nwqid * |
| 259 | sizeof(struct p9_qid), |
| 260 | GFP_KERNEL); |
| 261 | if (*wqids == NULL) |
| 262 | errcode = -ENOMEM; |
| 263 | } |
| 264 | |
| 265 | if (!errcode) { |
| 266 | int i; |
| 267 | |
| 268 | for (i = 0; i < *nwqid; i++) { |
| 269 | errcode = |
| 270 | p9pdu_readf(pdu, optional, |
| 271 | "Q", |
| 272 | &(*wqids)[i]); |
| 273 | if (errcode) |
| 274 | break; |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | if (errcode) { |
| 279 | kfree(*wqids); |
| 280 | *wqids = NULL; |
| 281 | } |
| 282 | } |
| 283 | break; |
| 284 | case '?': |
| 285 | if (!optional) |
| 286 | return 0; |
| 287 | break; |
| 288 | default: |
| 289 | BUG(); |
| 290 | break; |
| 291 | } |
| 292 | |
| 293 | if (errcode) |
| 294 | break; |
| 295 | } |
| 296 | |
| 297 | return errcode; |
| 298 | } |
| 299 | |
| 300 | int |
| 301 | p9pdu_vwritef(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap) |
| 302 | { |
| 303 | const char *ptr; |
| 304 | int errcode = 0; |
| 305 | |
| 306 | for (ptr = fmt; *ptr; ptr++) { |
| 307 | switch (*ptr) { |
| 308 | case 'b':{ |
| 309 | int8_t val = va_arg(ap, int); |
| 310 | if (pdu_write(pdu, &val, sizeof(val))) |
| 311 | errcode = -EFAULT; |
| 312 | } |
| 313 | break; |
| 314 | case 'w':{ |
| 315 | int16_t val = va_arg(ap, int); |
| 316 | if (pdu_write(pdu, &val, sizeof(val))) |
| 317 | errcode = -EFAULT; |
| 318 | } |
| 319 | break; |
| 320 | case 'd':{ |
| 321 | int32_t val = va_arg(ap, int32_t); |
| 322 | if (pdu_write(pdu, &val, sizeof(val))) |
| 323 | errcode = -EFAULT; |
| 324 | } |
| 325 | break; |
| 326 | case 'q':{ |
| 327 | int64_t val = va_arg(ap, int64_t); |
| 328 | if (pdu_write(pdu, &val, sizeof(val))) |
| 329 | errcode = -EFAULT; |
| 330 | } |
| 331 | break; |
| 332 | case 's':{ |
| 333 | const char *ptr = va_arg(ap, const char *); |
| 334 | int16_t len = 0; |
| 335 | |
| 336 | if (ptr) |
| 337 | len = MIN(strlen(ptr), USHORT_MAX); |
| 338 | |
| 339 | errcode = p9pdu_writef(pdu, optional, "w", len); |
| 340 | if (!errcode && pdu_write(pdu, ptr, len)) |
| 341 | errcode = -EFAULT; |
| 342 | } |
| 343 | break; |
| 344 | case 'Q':{ |
| 345 | const struct p9_qid *qid = |
| 346 | va_arg(ap, const struct p9_qid *); |
| 347 | errcode = |
| 348 | p9pdu_writef(pdu, optional, "bdq", |
| 349 | qid->type, qid->version, |
| 350 | qid->path); |
| 351 | } break; |
| 352 | case 'S':{ |
| 353 | const struct p9_wstat *stbuf = |
| 354 | va_arg(ap, const struct p9_wstat *); |
| 355 | errcode = |
| 356 | p9pdu_writef(pdu, optional, |
| 357 | "wwdQdddqssss?sddd", |
| 358 | stbuf->size, stbuf->type, |
| 359 | stbuf->dev, stbuf->qid, |
| 360 | stbuf->mode, stbuf->atime, |
| 361 | stbuf->mtime, stbuf->length, |
| 362 | stbuf->name, stbuf->uid, |
| 363 | stbuf->gid, stbuf->muid, |
| 364 | stbuf->extension, stbuf->n_uid, |
| 365 | stbuf->n_gid, stbuf->n_muid); |
| 366 | } break; |
| 367 | case 'D':{ |
| 368 | int32_t count = va_arg(ap, int32_t); |
| 369 | const void *data = va_arg(ap, const void *); |
| 370 | |
| 371 | errcode = |
| 372 | p9pdu_writef(pdu, optional, "d", count); |
| 373 | if (!errcode && pdu_write(pdu, data, count)) |
| 374 | errcode = -EFAULT; |
| 375 | } |
| 376 | break; |
| 377 | case 'T':{ |
| 378 | int16_t nwname = va_arg(ap, int); |
| 379 | const char **wnames = va_arg(ap, const char **); |
| 380 | |
| 381 | errcode = |
| 382 | p9pdu_writef(pdu, optional, "w", nwname); |
| 383 | if (!errcode) { |
| 384 | int i; |
| 385 | |
| 386 | for (i = 0; i < nwname; i++) { |
| 387 | errcode = |
| 388 | p9pdu_writef(pdu, optional, |
| 389 | "s", |
| 390 | wnames[i]); |
| 391 | if (errcode) |
| 392 | break; |
| 393 | } |
| 394 | } |
| 395 | } |
| 396 | break; |
| 397 | case 'R':{ |
| 398 | int16_t nwqid = va_arg(ap, int); |
| 399 | struct p9_qid *wqids = |
| 400 | va_arg(ap, struct p9_qid *); |
| 401 | |
| 402 | errcode = |
| 403 | p9pdu_writef(pdu, optional, "w", nwqid); |
| 404 | if (!errcode) { |
| 405 | int i; |
| 406 | |
| 407 | for (i = 0; i < nwqid; i++) { |
| 408 | errcode = |
| 409 | p9pdu_writef(pdu, optional, |
| 410 | "Q", |
| 411 | &wqids[i]); |
| 412 | if (errcode) |
| 413 | break; |
| 414 | } |
| 415 | } |
| 416 | } |
| 417 | break; |
| 418 | case '?': |
| 419 | if (!optional) |
| 420 | return 0; |
| 421 | break; |
| 422 | default: |
| 423 | BUG(); |
| 424 | break; |
| 425 | } |
| 426 | |
| 427 | if (errcode) |
| 428 | break; |
| 429 | } |
| 430 | |
| 431 | return errcode; |
| 432 | } |
| 433 | |
| 434 | int p9pdu_readf(struct p9_fcall *pdu, int optional, const char *fmt, ...) |
| 435 | { |
| 436 | va_list ap; |
| 437 | int ret; |
| 438 | |
| 439 | va_start(ap, fmt); |
| 440 | ret = p9pdu_vreadf(pdu, optional, fmt, ap); |
| 441 | va_end(ap); |
| 442 | |
| 443 | return ret; |
| 444 | } |
| 445 | |
| 446 | static int |
| 447 | p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...) |
| 448 | { |
| 449 | va_list ap; |
| 450 | int ret; |
| 451 | |
| 452 | va_start(ap, fmt); |
| 453 | ret = p9pdu_vwritef(pdu, optional, fmt, ap); |
| 454 | va_end(ap); |
| 455 | |
| 456 | return ret; |
| 457 | } |