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