cutils.c

   1 /*
   2  * Simple C functions to supplement the C library
   3  *
   4  * Copyright (c) 2006 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu-common.h"
  25 #include "host-utils.h"
  26 #include <math.h>
  27
  28 #include "qemu_socket.h"
  29
  30 void pstrcpy(char *buf, int buf_size, const char *str)
  31 {
  32     int c;
  33     char *q = buf;
  34
  35     if (buf_size <= 0)
  36         return;
  37
  38     for(;;) {
  39         c = *str++;
  40         if (c == 0 || q >= buf + buf_size - 1)
  41             break;
  42         *q++ = c;
  43     }
  44     *q = '\0';
  45 }
  46
  47 /* strcat and truncate. */
  48 char *pstrcat(char *buf, int buf_size, const char *s)
  49 {
  50     int len;
  51     len = strlen(buf);
  52     if (len < buf_size)
  53         pstrcpy(buf + len, buf_size - len, s);
  54     return buf;
  55 }
  56
  57 int strstart(const char *str, const char *val, const char **ptr)
  58 {
  59     const char *p, *q;
  60     p = str;
  61     q = val;
  62     while (*q != '\0') {
  63         if (*p != *q)
  64             return 0;
  65         p++;
  66         q++;
  67     }
  68     if (ptr)
  69         *ptr = p;
  70     return 1;
  71 }
  72
  73 int stristart(const char *str, const char *val, const char **ptr)
  74 {
  75     const char *p, *q;
  76     p = str;
  77     q = val;
  78     while (*q != '\0') {
  79         if (qemu_toupper(*p) != qemu_toupper(*q))
  80             return 0;
  81         p++;
  82         q++;
  83     }
  84     if (ptr)
  85         *ptr = p;
  86     return 1;
  87 }
  88
  89 /* XXX: use host strnlen if available ? */
  90 int qemu_strnlen(const char *s, int max_len)
  91 {
  92     int i;
  93
  94     for(i = 0; i < max_len; i++) {
  95         if (s[i] == '\0') {
  96             break;
  97         }
  98     }
  99     return i;
 100 }
 101
 102 time_t mktimegm(struct tm *tm)
 103 {
 104     time_t t;
 105     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 106     if (m < 3) {
 107         m += 12;
 108         y--;
 109     }
 110     t = 86400 * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 111                  y / 400 - 719469);
 112     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 113     return t;
 114 }
 115
 116 int qemu_fls(int i)
 117 {
 118     return 32 - clz32(i);
 119 }
 120
 121 /*
 122  * Make sure data goes on disk, but if possible do not bother to
 123  * write out the inode just for timestamp updates.
 124  *
 125  * Unfortunately even in 2009 many operating systems do not support
 126  * fdatasync and have to fall back to fsync.
 127  */
 128 int qemu_fdatasync(int fd)
 129 {
 130 #ifdef CONFIG_FDATASYNC
 131     return fdatasync(fd);
 132 #else
 133     return fsync(fd);
 134 #endif
 135 }
 136
 137 /* io vectors */
 138
 139 void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
 140 {
 141     qiov->iov = g_malloc(alloc_hint * sizeof(struct iovec));
 142     qiov->niov = 0;
 143     qiov->nalloc = alloc_hint;
 144     qiov->size = 0;
 145 }
 146
 147 void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov)
 148 {
 149     int i;
 150
 151     qiov->iov = iov;
 152     qiov->niov = niov;
 153     qiov->nalloc = -1;
 154     qiov->size = 0;
 155     for (i = 0; i < niov; i++)
 156         qiov->size += iov[i].iov_len;
 157 }
 158
 159 void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
 160 {
 161     assert(qiov->nalloc != -1);
 162
 163     if (qiov->niov == qiov->nalloc) {
 164         qiov->nalloc = 2 * qiov->nalloc + 1;
 165         qiov->iov = g_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec));
 166     }
 167     qiov->iov[qiov->niov].iov_base = base;
 168     qiov->iov[qiov->niov].iov_len = len;
 169     qiov->size += len;
 170     ++qiov->niov;
 171 }
 172
 173 /*
 174  * Copies iovecs from src to the end of dst. It starts copying after skipping
 175  * the given number of bytes in src and copies until src is completely copied
 176  * or the total size of the copied iovec reaches size.The size of the last
 177  * copied iovec is changed in order to fit the specified total size if it isn't
 178  * a perfect fit already.
 179  */
 180 void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
 181     size_t size)
 182 {
 183     int i;
 184     size_t done;
 185     void *iov_base;
 186     uint64_t iov_len;
 187
 188     assert(dst->nalloc != -1);
 189
 190     done = 0;
 191     for (i = 0; (i < src->niov) && (done != size); i++) {
 192         if (skip >= src->iov[i].iov_len) {
 193             /* Skip the whole iov */
 194             skip -= src->iov[i].iov_len;
 195             continue;
 196         } else {
 197             /* Skip only part (or nothing) of the iov */
 198             iov_base = (uint8_t*) src->iov[i].iov_base + skip;
 199             iov_len = src->iov[i].iov_len - skip;
 200             skip = 0;
 201         }
 202
 203         if (done + iov_len > size) {
 204             qemu_iovec_add(dst, iov_base, size - done);
 205             break;
 206         } else {
 207             qemu_iovec_add(dst, iov_base, iov_len);
 208         }
 209         done += iov_len;
 210     }
 211 }
 212
 213 void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
 214 {
 215     qemu_iovec_copy(dst, src, 0, size);
 216 }
 217
 218 void qemu_iovec_destroy(QEMUIOVector *qiov)
 219 {
 220     assert(qiov->nalloc != -1);
 221
 222     qemu_iovec_reset(qiov);
 223     g_free(qiov->iov);
 224     qiov->nalloc = 0;
 225     qiov->iov = NULL;
 226 }
 227
 228 void qemu_iovec_reset(QEMUIOVector *qiov)
 229 {
 230     assert(qiov->nalloc != -1);
 231
 232     qiov->niov = 0;
 233     qiov->size = 0;
 234 }
 235
 236 void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
 237 {
 238     uint8_t *p = (uint8_t *)buf;
 239     int i;
 240
 241     for (i = 0; i < qiov->niov; ++i) {
 242         memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
 243         p += qiov->iov[i].iov_len;
 244     }
 245 }
 246
 247 void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void *buf, size_t count)
 248 {
 249     const uint8_t *p = (const uint8_t *)buf;
 250     size_t copy;
 251     int i;
 252
 253     for (i = 0; i < qiov->niov && count; ++i) {
 254         copy = count;
 255         if (copy > qiov->iov[i].iov_len)
 256             copy = qiov->iov[i].iov_len;
 257         memcpy(qiov->iov[i].iov_base, p, copy);
 258         p     += copy;
 259         count -= copy;
 260     }
 261 }
 262
 263 void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t count)
 264 {
 265     size_t n;
 266     int i;
 267
 268     for (i = 0; i < qiov->niov && count; ++i) {
 269         n = MIN(count, qiov->iov[i].iov_len);
 270         memset(qiov->iov[i].iov_base, c, n);
 271         count -= n;
 272     }
 273 }
 274
 275 void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count,
 276                             size_t skip)
 277 {
 278     int i;
 279     size_t done;
 280     void *iov_base;
 281     uint64_t iov_len;
 282
 283     done = 0;
 284     for (i = 0; (i < qiov->niov) && (done != count); i++) {
 285         if (skip >= qiov->iov[i].iov_len) {
 286             /* Skip the whole iov */
 287             skip -= qiov->iov[i].iov_len;
 288             continue;
 289         } else {
 290             /* Skip only part (or nothing) of the iov */
 291             iov_base = (uint8_t*) qiov->iov[i].iov_base + skip;
 292             iov_len = qiov->iov[i].iov_len - skip;
 293             skip = 0;
 294         }
 295
 296         if (done + iov_len > count) {
 297             memset(iov_base, c, count - done);
 298             break;
 299         } else {
 300             memset(iov_base, c, iov_len);
 301         }
 302         done += iov_len;
 303     }
 304 }
 305
 306 /*
 307  * Checks if a buffer is all zeroes
 308  *
 309  * Attention! The len must be a multiple of 4 * sizeof(long) due to
 310  * restriction of optimizations in this function.
 311  */
 312 bool buffer_is_zero(const void *buf, size_t len)
 313 {
 314     /*
 315      * Use long as the biggest available internal data type that fits into the
 316      * CPU register and unroll the loop to smooth out the effect of memory
 317      * latency.
 318      */
 319
 320     size_t i;
 321     long d0, d1, d2, d3;
 322     const long * const data = buf;
 323
 324     assert(len % (4 * sizeof(long)) == 0);
 325     len /= sizeof(long);
 326
 327     for (i = 0; i < len; i += 4) {
 328         d0 = data[i + 0];
 329         d1 = data[i + 1];
 330         d2 = data[i + 2];
 331         d3 = data[i + 3];
 332
 333         if (d0 || d1 || d2 || d3) {
 334             return false;
 335         }
 336     }
 337
 338     return true;
 339 }
 340
 341 #ifndef _WIN32
 342 /* Sets a specific flag */
 343 int fcntl_setfl(int fd, int flag)
 344 {
 345     int flags;
 346
 347     flags = fcntl(fd, F_GETFL);
 348     if (flags == -1)
 349         return -errno;
 350
 351     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 352         return -errno;
 353
 354     return 0;
 355 }
 356 #endif
 357
 358 static int64_t suffix_mul(char suffix, int64_t unit)
 359 {
 360     switch (qemu_toupper(suffix)) {
 361     case STRTOSZ_DEFSUFFIX_B:
 362         return 1;
 363     case STRTOSZ_DEFSUFFIX_KB:
 364         return unit;
 365     case STRTOSZ_DEFSUFFIX_MB:
 366         return unit * unit;
 367     case STRTOSZ_DEFSUFFIX_GB:
 368         return unit * unit * unit;
 369     case STRTOSZ_DEFSUFFIX_TB:
 370         return unit * unit * unit * unit;
 371     }
 372     return -1;
 373 }
 374
 375 /*
 376  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 377  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 378  * in *end, if not NULL. Return -1 on error.
 379  */
 380 int64_t strtosz_suffix_unit(const char *nptr, char **end,
 381                             const char default_suffix, int64_t unit)
 382 {
 383     int64_t retval = -1;
 384     char *endptr;
 385     unsigned char c;
 386     int mul_required = 0;
 387     double val, mul, integral, fraction;
 388
 389     errno = 0;
 390     val = strtod(nptr, &endptr);
 391     if (isnan(val) || endptr == nptr || errno != 0) {
 392         goto fail;
 393     }
 394     fraction = modf(val, &integral);
 395     if (fraction != 0) {
 396         mul_required = 1;
 397     }
 398     c = *endptr;
 399     mul = suffix_mul(c, unit);
 400     if (mul >= 0) {
 401         endptr++;
 402     } else {
 403         mul = suffix_mul(default_suffix, unit);
 404         assert(mul >= 0);
 405     }
 406     if (mul == 1 && mul_required) {
 407         goto fail;
 408     }
 409     if ((val * mul >= INT64_MAX) || val < 0) {
 410         goto fail;
 411     }
 412     retval = val * mul;
 413
 414 fail:
 415     if (end) {
 416         *end = endptr;
 417     }
 418
 419     return retval;
 420 }
 421
 422 int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
 423 {
 424     return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 425 }
 426
 427 int64_t strtosz(const char *nptr, char **end)
 428 {
 429     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
 430 }
 431
 432 int qemu_parse_fd(const char *param)
 433 {
 434     int fd;
 435     char *endptr = NULL;
 436
 437     fd = strtol(param, &endptr, 10);
 438     if (*endptr || (fd == 0 && param == endptr)) {
 439         return -1;
 440     }
 441     return fd;
 442 }
 443
 444 /*
 445  * Send/recv data with iovec buffers
 446  *
 447  * This function send/recv data from/to the iovec buffer directly.
 448  * The first `offset' bytes in the iovec buffer are skipped and next
 449  * `len' bytes are used.
 450  *
 451  * For example,
 452  *
 453  *   do_sendv_recvv(sockfd, iov, len, offset, 1);
 454  *
 455  * is equal to
 456  *
 457  *   char *buf = malloc(size);
 458  *   iov_to_buf(iov, iovcnt, buf, offset, size);
 459  *   send(sockfd, buf, size, 0);
 460  *   free(buf);
 461  */
 462 static int do_sendv_recvv(int sockfd, struct iovec *iov, int len, int offset,
 463                           int do_sendv)
 464 {
 465     int ret, diff, iovlen;
 466     struct iovec *last_iov;
 467
 468     /* last_iov is inclusive, so count from one.  */
 469     iovlen = 1;
 470     last_iov = iov;
 471     len += offset;
 472
 473     while (last_iov->iov_len < len) {
 474         len -= last_iov->iov_len;
 475
 476         last_iov++;
 477         iovlen++;
 478     }
 479
 480     diff = last_iov->iov_len - len;
 481     last_iov->iov_len -= diff;
 482
 483     while (iov->iov_len <= offset) {
 484         offset -= iov->iov_len;
 485
 486         iov++;
 487         iovlen--;
 488     }
 489
 490     iov->iov_base = (char *) iov->iov_base + offset;
 491     iov->iov_len -= offset;
 492
 493     {
 494 #if defined CONFIG_IOVEC && defined CONFIG_POSIX
 495         struct msghdr msg;
 496         memset(&msg, 0, sizeof(msg));
 497         msg.msg_iov = iov;
 498         msg.msg_iovlen = iovlen;
 499
 500         do {
 501             if (do_sendv) {
 502                 ret = sendmsg(sockfd, &msg, 0);
 503             } else {
 504                 ret = recvmsg(sockfd, &msg, 0);
 505             }
 506         } while (ret == -1 && errno == EINTR);
 507 #else
 508         struct iovec *p = iov;
 509         ret = 0;
 510         while (iovlen > 0) {
 511             int rc;
 512             if (do_sendv) {
 513                 rc = send(sockfd, p->iov_base, p->iov_len, 0);
 514             } else {
 515                 rc = qemu_recv(sockfd, p->iov_base, p->iov_len, 0);
 516             }
 517             if (rc == -1) {
 518                 if (errno == EINTR) {
 519                     continue;
 520                 }
 521                 if (ret == 0) {
 522                     ret = -1;
 523                 }
 524                 break;
 525             }
 526             if (rc == 0) {
 527                 break;
 528             }
 529             ret += rc;
 530             iovlen--, p++;
 531         }
 532 #endif
 533     }
 534
 535     /* Undo the changes above */
 536     iov->iov_base = (char *) iov->iov_base - offset;
 537     iov->iov_len += offset;
 538     last_iov->iov_len += diff;
 539     return ret;
 540 }
 541
 542 int qemu_recvv(int sockfd, struct iovec *iov, int len, int iov_offset)
 543 {
 544     return do_sendv_recvv(sockfd, iov, len, iov_offset, 0);
 545 }
 546
 547 int qemu_sendv(int sockfd, struct iovec *iov, int len, int iov_offset)
 548 {
 549     return do_sendv_recvv(sockfd, iov, len, iov_offset, 1);
 550 }
 551