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 = g_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 = g_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_iovec_reset(qiov);
 221     g_free(qiov->iov);
 222     qiov->nalloc = 0;
 223     qiov->iov = NULL;
 224 }
 225
 226 void qemu_iovec_reset(QEMUIOVector *qiov)
 227 {
 228     assert(qiov->nalloc != -1);
 229
 230     qiov->niov = 0;
 231     qiov->size = 0;
 232 }
 233
 234 void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
 235 {
 236     uint8_t *p = (uint8_t *)buf;
 237     int i;
 238
 239     for (i = 0; i < qiov->niov; ++i) {
 240         memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
 241         p += qiov->iov[i].iov_len;
 242     }
 243 }
 244
 245 void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void *buf, size_t count)
 246 {
 247     const uint8_t *p = (const uint8_t *)buf;
 248     size_t copy;
 249     int i;
 250
 251     for (i = 0; i < qiov->niov && count; ++i) {
 252         copy = count;
 253         if (copy > qiov->iov[i].iov_len)
 254             copy = qiov->iov[i].iov_len;
 255         memcpy(qiov->iov[i].iov_base, p, copy);
 256         p     += copy;
 257         count -= copy;
 258     }
 259 }
 260
 261 void qemu_iovec_memset(QEMUIOVector *qiov, int c, size_t count)
 262 {
 263     size_t n;
 264     int i;
 265
 266     for (i = 0; i < qiov->niov && count; ++i) {
 267         n = MIN(count, qiov->iov[i].iov_len);
 268         memset(qiov->iov[i].iov_base, c, n);
 269         count -= n;
 270     }
 271 }
 272
 273 void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count,
 274                             size_t skip)
 275 {
 276     int i;
 277     size_t done;
 278     void *iov_base;
 279     uint64_t iov_len;
 280
 281     done = 0;
 282     for (i = 0; (i < qiov->niov) && (done != count); i++) {
 283         if (skip >= qiov->iov[i].iov_len) {
 284             /* Skip the whole iov */
 285             skip -= qiov->iov[i].iov_len;
 286             continue;
 287         } else {
 288             /* Skip only part (or nothing) of the iov */
 289             iov_base = (uint8_t*) qiov->iov[i].iov_base + skip;
 290             iov_len = qiov->iov[i].iov_len - skip;
 291             skip = 0;
 292         }
 293
 294         if (done + iov_len > count) {
 295             memset(iov_base, c, count - done);
 296             break;
 297         } else {
 298             memset(iov_base, c, iov_len);
 299         }
 300         done += iov_len;
 301     }
 302 }
 303
 304 #ifndef _WIN32
 305 /* Sets a specific flag */
 306 int fcntl_setfl(int fd, int flag)
 307 {
 308     int flags;
 309
 310     flags = fcntl(fd, F_GETFL);
 311     if (flags == -1)
 312         return -errno;
 313
 314     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 315         return -errno;
 316
 317     return 0;
 318 }
 319 #endif
 320
 321 static int64_t suffix_mul(char suffix, int64_t unit)
 322 {
 323     switch (qemu_toupper(suffix)) {
 324     case STRTOSZ_DEFSUFFIX_B:
 325         return 1;
 326     case STRTOSZ_DEFSUFFIX_KB:
 327         return unit;
 328     case STRTOSZ_DEFSUFFIX_MB:
 329         return unit * unit;
 330     case STRTOSZ_DEFSUFFIX_GB:
 331         return unit * unit * unit;
 332     case STRTOSZ_DEFSUFFIX_TB:
 333         return unit * unit * unit * unit;
 334     }
 335     return -1;
 336 }
 337
 338 /*
 339  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 340  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 341  * in *end, if not NULL. Return -1 on error.
 342  */
 343 int64_t strtosz_suffix_unit(const char *nptr, char **end,
 344                             const char default_suffix, int64_t unit)
 345 {
 346     int64_t retval = -1;
 347     char *endptr;
 348     unsigned char c;
 349     int mul_required = 0;
 350     double val, mul, integral, fraction;
 351
 352     errno = 0;
 353     val = strtod(nptr, &endptr);
 354     if (isnan(val) || endptr == nptr || errno != 0) {
 355         goto fail;
 356     }
 357     fraction = modf(val, &integral);
 358     if (fraction != 0) {
 359         mul_required = 1;
 360     }
 361     c = *endptr;
 362     mul = suffix_mul(c, unit);
 363     if (mul >= 0) {
 364         endptr++;
 365     } else {
 366         mul = suffix_mul(default_suffix, unit);
 367         assert(mul >= 0);
 368     }
 369     if (mul == 1 && mul_required) {
 370         goto fail;
 371     }
 372     if ((val * mul >= INT64_MAX) || val < 0) {
 373         goto fail;
 374     }
 375     retval = val * mul;
 376
 377 fail:
 378     if (end) {
 379         *end = endptr;
 380     }
 381
 382     return retval;
 383 }
 384
 385 int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
 386 {
 387     return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 388 }
 389
 390 int64_t strtosz(const char *nptr, char **end)
 391 {
 392     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
 393 }
 394
 395 int qemu_parse_fd(const char *param)
 396 {
 397     int fd;
 398     char *endptr = NULL;
 399
 400     fd = strtol(param, &endptr, 10);
 401     if (*endptr || (fd == 0 && param == endptr)) {
 402         return -1;
 403     }
 404     return fd;
 405 }