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 void pstrcpy(char *buf, int buf_size, const char *str)
  29 {
  30     int c;
  31     char *q = buf;
  32
  33     if (buf_size <= 0)
  34         return;
  35
  36     for(;;) {
  37         c = *str++;
  38         if (c == 0 || q >= buf + buf_size - 1)
  39             break;
  40         *q++ = c;
  41     }
  42     *q = '\0';
  43 }
  44
  45 /* strcat and truncate. */
  46 char *pstrcat(char *buf, int buf_size, const char *s)
  47 {
  48     int len;
  49     len = strlen(buf);
  50     if (len < buf_size)
  51         pstrcpy(buf + len, buf_size - len, s);
  52     return buf;
  53 }
  54
  55 int strstart(const char *str, const char *val, const char **ptr)
  56 {
  57     const char *p, *q;
  58     p = str;
  59     q = val;
  60     while (*q != '\0') {
  61         if (*p != *q)
  62             return 0;
  63         p++;
  64         q++;
  65     }
  66     if (ptr)
  67         *ptr = p;
  68     return 1;
  69 }
  70
  71 int stristart(const char *str, const char *val, const char **ptr)
  72 {
  73     const char *p, *q;
  74     p = str;
  75     q = val;
  76     while (*q != '\0') {
  77         if (qemu_toupper(*p) != qemu_toupper(*q))
  78             return 0;
  79         p++;
  80         q++;
  81     }
  82     if (ptr)
  83         *ptr = p;
  84     return 1;
  85 }
  86
  87 /* XXX: use host strnlen if available ? */
  88 int qemu_strnlen(const char *s, int max_len)
  89 {
  90     int i;
  91
  92     for(i = 0; i < max_len; i++) {
  93         if (s[i] == '\0') {
  94             break;
  95         }
  96     }
  97     return i;
  98 }
  99
 100 time_t mktimegm(struct tm *tm)
 101 {
 102     time_t t;
 103     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 104     if (m < 3) {
 105         m += 12;
 106         y--;
 107     }
 108     t = 86400 * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 109                  y / 400 - 719469);
 110     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 111     return t;
 112 }
 113
 114 int qemu_fls(int i)
 115 {
 116     return 32 - clz32(i);
 117 }
 118
 119 /*
 120  * Make sure data goes on disk, but if possible do not bother to
 121  * write out the inode just for timestamp updates.
 122  *
 123  * Unfortunately even in 2009 many operating systems do not support
 124  * fdatasync and have to fall back to fsync.
 125  */
 126 int qemu_fdatasync(int fd)
 127 {
 128 #ifdef CONFIG_FDATASYNC
 129     return fdatasync(fd);
 130 #else
 131     return fsync(fd);
 132 #endif
 133 }
 134
 135 /* io vectors */
 136
 137 void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
 138 {
 139     qiov->iov = qemu_malloc(alloc_hint * sizeof(struct iovec));
 140     qiov->niov = 0;
 141     qiov->nalloc = alloc_hint;
 142     qiov->size = 0;
 143 }
 144
 145 void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov)
 146 {
 147     int i;
 148
 149     qiov->iov = iov;
 150     qiov->niov = niov;
 151     qiov->nalloc = -1;
 152     qiov->size = 0;
 153     for (i = 0; i < niov; i++)
 154         qiov->size += iov[i].iov_len;
 155 }
 156
 157 void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
 158 {
 159     assert(qiov->nalloc != -1);
 160
 161     if (qiov->niov == qiov->nalloc) {
 162         qiov->nalloc = 2 * qiov->nalloc + 1;
 163         qiov->iov = qemu_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec));
 164     }
 165     qiov->iov[qiov->niov].iov_base = base;
 166     qiov->iov[qiov->niov].iov_len = len;
 167     qiov->size += len;
 168     ++qiov->niov;
 169 }
 170
 171 /*
 172  * Copies iovecs from src to the end of dst. It starts copying after skipping
 173  * the given number of bytes in src and copies until src is completely copied
 174  * or the total size of the copied iovec reaches size.The size of the last
 175  * copied iovec is changed in order to fit the specified total size if it isn't
 176  * a perfect fit already.
 177  */
 178 void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
 179     size_t size)
 180 {
 181     int i;
 182     size_t done;
 183     void *iov_base;
 184     uint64_t iov_len;
 185
 186     assert(dst->nalloc != -1);
 187
 188     done = 0;
 189     for (i = 0; (i < src->niov) && (done != size); i++) {
 190         if (skip >= src->iov[i].iov_len) {
 191             /* Skip the whole iov */
 192             skip -= src->iov[i].iov_len;
 193             continue;
 194         } else {
 195             /* Skip only part (or nothing) of the iov */
 196             iov_base = (uint8_t*) src->iov[i].iov_base + skip;
 197             iov_len = src->iov[i].iov_len - skip;
 198             skip = 0;
 199         }
 200
 201         if (done + iov_len > size) {
 202             qemu_iovec_add(dst, iov_base, size - done);
 203             break;
 204         } else {
 205             qemu_iovec_add(dst, iov_base, iov_len);
 206         }
 207         done += iov_len;
 208     }
 209 }
 210
 211 void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
 212 {
 213     qemu_iovec_copy(dst, src, 0, size);
 214 }
 215
 216 void qemu_iovec_destroy(QEMUIOVector *qiov)
 217 {
 218     assert(qiov->nalloc != -1);
 219
 220     qemu_free(qiov->iov);
 221 }
 222
 223 void qemu_iovec_reset(QEMUIOVector *qiov)
 224 {
 225     assert(qiov->nalloc != -1);
 226
 227     qiov->niov = 0;
 228     qiov->size = 0;
 229 }
 230
 231 void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
 232 {
 233     uint8_t *p = (uint8_t *)buf;
 234     int i;
 235
 236     for (i = 0; i < qiov->niov; ++i) {
 237         memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
 238         p += qiov->iov[i].iov_len;
 239     }
 240 }
 241
 242 /*
 243  * No dma flushing needed here, as the aio code will call dma_bdrv_cb()
 244  * on completion as well, which will result in a call to
 245  * dma_bdrv_unmap() which will do the flushing ....
 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 #ifndef _WIN32
 276 /* Sets a specific flag */
 277 int fcntl_setfl(int fd, int flag)
 278 {
 279     int flags;
 280
 281     flags = fcntl(fd, F_GETFL);
 282     if (flags == -1)
 283         return -errno;
 284
 285     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 286         return -errno;
 287
 288     return 0;
 289 }
 290 #endif
 291
 292 /*
 293  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 294  * M/m for MB, G/g for GB or T/t for TB. Default without any postfix
 295  * is MB. End pointer will be returned in *end, if not NULL. A valid
 296  * value must be terminated by whitespace, ',' or '\0'. Return -1 on
 297  * error.
 298  */
 299 ssize_t strtosz(const char *nptr, char **end)
 300 {
 301     ssize_t retval = -1;
 302     char *endptr, c;
 303     int mul_required = 0;
 304     double val, mul, integral, fraction;
 305
 306     errno = 0;
 307     val = strtod(nptr, &endptr);
 308     if (isnan(val) || endptr == nptr || errno != 0) {
 309         goto fail;
 310     }
 311     integral = modf(val, &fraction);
 312     if (integral != 0) {
 313         mul_required = 1;
 314     }
 315     /*
 316      * Any whitespace character is fine for terminating the number,
 317      * in addition we accept ',' to handle strings where the size is
 318      * part of a multi token argument.
 319      */
 320     c = *endptr;
 321     if (isspace(c) || c == '\0' || c == ',') {
 322         c = 0;
 323     }
 324     switch (c) {
 325     case 'B':
 326     case 'b':
 327         mul = 1;
 328         if (mul_required) {
 329             goto fail;
 330         }
 331         break;
 332     case 'K':
 333     case 'k':
 334         mul = 1 << 10;
 335         break;
 336     case 0:
 337         if (mul_required) {
 338             goto fail;
 339         }
 340     case 'M':
 341     case 'm':
 342         mul = 1ULL << 20;
 343         break;
 344     case 'G':
 345     case 'g':
 346         mul = 1ULL << 30;
 347         break;
 348     case 'T':
 349     case 't':
 350         mul = 1ULL << 40;
 351         break;
 352     default:
 353         goto fail;
 354     }
 355     /*
 356      * If not terminated by whitespace, ',', or \0, increment endptr
 357      * to point to next character, then check that we are terminated
 358      * by an appropriate separating character, ie. whitespace, ',', or
 359      * \0. If not, we are seeing trailing garbage, thus fail.
 360      */
 361     if (c != 0) {
 362         endptr++;
 363         if (!isspace(*endptr) && *endptr != ',' && *endptr != 0) {
 364             goto fail;
 365         }
 366     }
 367     if ((val * mul >= ~(size_t)0) || val < 0) {
 368         goto fail;
 369     }
 370     retval = val * mul;
 371
 372 fail:
 373     if (end) {
 374         *end = endptr;
 375     }
 376
 377     return retval;
 378 }