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 strpadcpy(char *buf, int buf_size, const char *str, char pad)
  32 {
  33     int len = qemu_strnlen(str, buf_size);
  34     memcpy(buf, str, len);
  35     memset(buf + len, pad, buf_size - len);
  36 }
  37
  38 void pstrcpy(char *buf, int buf_size, const char *str)
  39 {
  40     int c;
  41     char *q = buf;
  42
  43     if (buf_size <= 0)
  44         return;
  45
  46     for(;;) {
  47         c = *str++;
  48         if (c == 0 || q >= buf + buf_size - 1)
  49             break;
  50         *q++ = c;
  51     }
  52     *q = '\0';
  53 }
  54
  55 /* strcat and truncate. */
  56 char *pstrcat(char *buf, int buf_size, const char *s)
  57 {
  58     int len;
  59     len = strlen(buf);
  60     if (len < buf_size)
  61         pstrcpy(buf + len, buf_size - len, s);
  62     return buf;
  63 }
  64
  65 int strstart(const char *str, const char *val, const char **ptr)
  66 {
  67     const char *p, *q;
  68     p = str;
  69     q = val;
  70     while (*q != '\0') {
  71         if (*p != *q)
  72             return 0;
  73         p++;
  74         q++;
  75     }
  76     if (ptr)
  77         *ptr = p;
  78     return 1;
  79 }
  80
  81 int stristart(const char *str, const char *val, const char **ptr)
  82 {
  83     const char *p, *q;
  84     p = str;
  85     q = val;
  86     while (*q != '\0') {
  87         if (qemu_toupper(*p) != qemu_toupper(*q))
  88             return 0;
  89         p++;
  90         q++;
  91     }
  92     if (ptr)
  93         *ptr = p;
  94     return 1;
  95 }
  96
  97 /* XXX: use host strnlen if available ? */
  98 int qemu_strnlen(const char *s, int max_len)
  99 {
 100     int i;
 101
 102     for(i = 0; i < max_len; i++) {
 103         if (s[i] == '\0') {
 104             break;
 105         }
 106     }
 107     return i;
 108 }
 109
 110 time_t mktimegm(struct tm *tm)
 111 {
 112     time_t t;
 113     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 114     if (m < 3) {
 115         m += 12;
 116         y--;
 117     }
 118     t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 119                  y / 400 - 719469);
 120     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 121     return t;
 122 }
 123
 124 int qemu_fls(int i)
 125 {
 126     return 32 - clz32(i);
 127 }
 128
 129 /*
 130  * Make sure data goes on disk, but if possible do not bother to
 131  * write out the inode just for timestamp updates.
 132  *
 133  * Unfortunately even in 2009 many operating systems do not support
 134  * fdatasync and have to fall back to fsync.
 135  */
 136 int qemu_fdatasync(int fd)
 137 {
 138 #ifdef CONFIG_FDATASYNC
 139     return fdatasync(fd);
 140 #else
 141     return fsync(fd);
 142 #endif
 143 }
 144
 145 /* io vectors */
 146
 147 void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
 148 {
 149     qiov->iov = g_malloc(alloc_hint * sizeof(struct iovec));
 150     qiov->niov = 0;
 151     qiov->nalloc = alloc_hint;
 152     qiov->size = 0;
 153 }
 154
 155 void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov)
 156 {
 157     int i;
 158
 159     qiov->iov = iov;
 160     qiov->niov = niov;
 161     qiov->nalloc = -1;
 162     qiov->size = 0;
 163     for (i = 0; i < niov; i++)
 164         qiov->size += iov[i].iov_len;
 165 }
 166
 167 void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
 168 {
 169     assert(qiov->nalloc != -1);
 170
 171     if (qiov->niov == qiov->nalloc) {
 172         qiov->nalloc = 2 * qiov->nalloc + 1;
 173         qiov->iov = g_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec));
 174     }
 175     qiov->iov[qiov->niov].iov_base = base;
 176     qiov->iov[qiov->niov].iov_len = len;
 177     qiov->size += len;
 178     ++qiov->niov;
 179 }
 180
 181 /*
 182  * Concatenates (partial) iovecs from src to the end of dst.
 183  * It starts copying after skipping `soffset' bytes at the
 184  * beginning of src and adds individual vectors from src to
 185  * dst copies up to `sbytes' bytes total, or up to the end
 186  * of src if it comes first.  This way, it is okay to specify
 187  * very large value for `sbytes' to indicate "up to the end
 188  * of src".
 189  * Only vector pointers are processed, not the actual data buffers.
 190  */
 191 void qemu_iovec_concat(QEMUIOVector *dst,
 192                        QEMUIOVector *src, size_t soffset, size_t sbytes)
 193 {
 194     int i;
 195     size_t done;
 196     struct iovec *siov = src->iov;
 197     assert(dst->nalloc != -1);
 198     assert(src->size >= soffset);
 199     for (i = 0, done = 0; done < sbytes && i < src->niov; i++) {
 200         if (soffset < siov[i].iov_len) {
 201             size_t len = MIN(siov[i].iov_len - soffset, sbytes - done);
 202             qemu_iovec_add(dst, siov[i].iov_base + soffset, len);
 203             done += len;
 204             soffset = 0;
 205         } else {
 206             soffset -= siov[i].iov_len;
 207         }
 208     }
 209     /* return done; */
 210 }
 211
 212 void qemu_iovec_destroy(QEMUIOVector *qiov)
 213 {
 214     assert(qiov->nalloc != -1);
 215
 216     qemu_iovec_reset(qiov);
 217     g_free(qiov->iov);
 218     qiov->nalloc = 0;
 219     qiov->iov = NULL;
 220 }
 221
 222 void qemu_iovec_reset(QEMUIOVector *qiov)
 223 {
 224     assert(qiov->nalloc != -1);
 225
 226     qiov->niov = 0;
 227     qiov->size = 0;
 228 }
 229
 230 size_t qemu_iovec_to_buf(QEMUIOVector *qiov, size_t offset,
 231                          void *buf, size_t bytes)
 232 {
 233     return iov_to_buf(qiov->iov, qiov->niov, offset, buf, bytes);
 234 }
 235
 236 size_t qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
 237                            const void *buf, size_t bytes)
 238 {
 239     return iov_from_buf(qiov->iov, qiov->niov, offset, buf, bytes);
 240 }
 241
 242 size_t qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
 243                          int fillc, size_t bytes)
 244 {
 245     return iov_memset(qiov->iov, qiov->niov, offset, fillc, bytes);
 246 }
 247
 248 /*
 249  * Checks if a buffer is all zeroes
 250  *
 251  * Attention! The len must be a multiple of 4 * sizeof(long) due to
 252  * restriction of optimizations in this function.
 253  */
 254 bool buffer_is_zero(const void *buf, size_t len)
 255 {
 256     /*
 257      * Use long as the biggest available internal data type that fits into the
 258      * CPU register and unroll the loop to smooth out the effect of memory
 259      * latency.
 260      */
 261
 262     size_t i;
 263     long d0, d1, d2, d3;
 264     const long * const data = buf;
 265
 266     assert(len % (4 * sizeof(long)) == 0);
 267     len /= sizeof(long);
 268
 269     for (i = 0; i < len; i += 4) {
 270         d0 = data[i + 0];
 271         d1 = data[i + 1];
 272         d2 = data[i + 2];
 273         d3 = data[i + 3];
 274
 275         if (d0 || d1 || d2 || d3) {
 276             return false;
 277         }
 278     }
 279
 280     return true;
 281 }
 282
 283 #ifndef _WIN32
 284 /* Sets a specific flag */
 285 int fcntl_setfl(int fd, int flag)
 286 {
 287     int flags;
 288
 289     flags = fcntl(fd, F_GETFL);
 290     if (flags == -1)
 291         return -errno;
 292
 293     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 294         return -errno;
 295
 296     return 0;
 297 }
 298 #endif
 299
 300 static int64_t suffix_mul(char suffix, int64_t unit)
 301 {
 302     switch (qemu_toupper(suffix)) {
 303     case STRTOSZ_DEFSUFFIX_B:
 304         return 1;
 305     case STRTOSZ_DEFSUFFIX_KB:
 306         return unit;
 307     case STRTOSZ_DEFSUFFIX_MB:
 308         return unit * unit;
 309     case STRTOSZ_DEFSUFFIX_GB:
 310         return unit * unit * unit;
 311     case STRTOSZ_DEFSUFFIX_TB:
 312         return unit * unit * unit * unit;
 313     }
 314     return -1;
 315 }
 316
 317 /*
 318  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 319  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 320  * in *end, if not NULL. Return -1 on error.
 321  */
 322 int64_t strtosz_suffix_unit(const char *nptr, char **end,
 323                             const char default_suffix, int64_t unit)
 324 {
 325     int64_t retval = -1;
 326     char *endptr;
 327     unsigned char c;
 328     int mul_required = 0;
 329     double val, mul, integral, fraction;
 330
 331     errno = 0;
 332     val = strtod(nptr, &endptr);
 333     if (isnan(val) || endptr == nptr || errno != 0) {
 334         goto fail;
 335     }
 336     fraction = modf(val, &integral);
 337     if (fraction != 0) {
 338         mul_required = 1;
 339     }
 340     c = *endptr;
 341     mul = suffix_mul(c, unit);
 342     if (mul >= 0) {
 343         endptr++;
 344     } else {
 345         mul = suffix_mul(default_suffix, unit);
 346         assert(mul >= 0);
 347     }
 348     if (mul == 1 && mul_required) {
 349         goto fail;
 350     }
 351     if ((val * mul >= INT64_MAX) || val < 0) {
 352         goto fail;
 353     }
 354     retval = val * mul;
 355
 356 fail:
 357     if (end) {
 358         *end = endptr;
 359     }
 360
 361     return retval;
 362 }
 363
 364 int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
 365 {
 366     return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 367 }
 368
 369 int64_t strtosz(const char *nptr, char **end)
 370 {
 371     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
 372 }
 373
 374 int qemu_parse_fd(const char *param)
 375 {
 376     int fd;
 377     char *endptr = NULL;
 378
 379     fd = strtol(param, &endptr, 10);
 380     if (*endptr || (fd == 0 && param == endptr)) {
 381         return -1;
 382     }
 383     return fd;
 384 }
 385
 386 int qemu_parse_fdset(const char *param)
 387 {
 388     return qemu_parse_fd(param);
 389 }
 390
 391 /* round down to the nearest power of 2*/
 392 int64_t pow2floor(int64_t value)
 393 {
 394     if (!is_power_of_2(value)) {
 395         value = 0x8000000000000000ULL >> clz64(value);
 396     }
 397     return value;
 398 }
 399
 400 /*
 401  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
 402  * Input is limited to 14-bit numbers
 403  */
 404 int uleb128_encode_small(uint8_t *out, uint32_t n)
 405 {
 406     g_assert(n <= 0x3fff);
 407     if (n < 0x80) {
 408         *out++ = n;
 409         return 1;
 410     } else {
 411         *out++ = (n & 0x7f) | 0x80;
 412         *out++ = n >> 7;
 413         return 2;
 414     }
 415 }
 416
 417 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 418 {
 419     if (!(*in & 0x80)) {
 420         *n = *in++;
 421         return 1;
 422     } else {
 423         *n = *in++ & 0x7f;
 424         /* we exceed 14 bit number */
 425         if (*in & 0x80) {
 426             return -1;
 427         }
 428         *n |= *in++ << 7;
 429         return 2;
 430     }
 431 }