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  * Concatenates (partial) iovecs from src to the end of dst.
 176  * It starts copying after skipping `soffset' bytes at the
 177  * beginning of src and adds individual vectors from src to
 178  * dst copies up to `sbytes' bytes total, or up to the end
 179  * of src if it comes first.  This way, it is okay to specify
 180  * very large value for `sbytes' to indicate "up to the end
 181  * of src".
 182  * Only vector pointers are processed, not the actual data buffers.
 183  */
 184 void qemu_iovec_concat(QEMUIOVector *dst,
 185                        QEMUIOVector *src, size_t soffset, size_t sbytes)
 186 {
 187     int i;
 188     size_t done;
 189     struct iovec *siov = src->iov;
 190     assert(dst->nalloc != -1);
 191     assert(src->size >= soffset);
 192     for (i = 0, done = 0; done < sbytes && i < src->niov; i++) {
 193         if (soffset < siov[i].iov_len) {
 194             size_t len = MIN(siov[i].iov_len - soffset, sbytes - done);
 195             qemu_iovec_add(dst, siov[i].iov_base + soffset, len);
 196             done += len;
 197             soffset = 0;
 198         } else {
 199             soffset -= siov[i].iov_len;
 200         }
 201     }
 202     /* return done; */
 203 }
 204
 205 void qemu_iovec_destroy(QEMUIOVector *qiov)
 206 {
 207     assert(qiov->nalloc != -1);
 208
 209     qemu_iovec_reset(qiov);
 210     g_free(qiov->iov);
 211     qiov->nalloc = 0;
 212     qiov->iov = NULL;
 213 }
 214
 215 void qemu_iovec_reset(QEMUIOVector *qiov)
 216 {
 217     assert(qiov->nalloc != -1);
 218
 219     qiov->niov = 0;
 220     qiov->size = 0;
 221 }
 222
 223 void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
 224 {
 225     uint8_t *p = (uint8_t *)buf;
 226     int i;
 227
 228     for (i = 0; i < qiov->niov; ++i) {
 229         memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
 230         p += qiov->iov[i].iov_len;
 231     }
 232 }
 233
 234 size_t qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
 235                            const void *buf, size_t bytes)
 236 {
 237     return iov_from_buf(qiov->iov, qiov->niov, offset, buf, bytes);
 238 }
 239
 240 size_t qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
 241                          int fillc, size_t bytes)
 242 {
 243     return iov_memset(qiov->iov, qiov->niov, offset, fillc, bytes);
 244 }
 245
 246 /*
 247  * Checks if a buffer is all zeroes
 248  *
 249  * Attention! The len must be a multiple of 4 * sizeof(long) due to
 250  * restriction of optimizations in this function.
 251  */
 252 bool buffer_is_zero(const void *buf, size_t len)
 253 {
 254     /*
 255      * Use long as the biggest available internal data type that fits into the
 256      * CPU register and unroll the loop to smooth out the effect of memory
 257      * latency.
 258      */
 259
 260     size_t i;
 261     long d0, d1, d2, d3;
 262     const long * const data = buf;
 263
 264     assert(len % (4 * sizeof(long)) == 0);
 265     len /= sizeof(long);
 266
 267     for (i = 0; i < len; i += 4) {
 268         d0 = data[i + 0];
 269         d1 = data[i + 1];
 270         d2 = data[i + 2];
 271         d3 = data[i + 3];
 272
 273         if (d0 || d1 || d2 || d3) {
 274             return false;
 275         }
 276     }
 277
 278     return true;
 279 }
 280
 281 #ifndef _WIN32
 282 /* Sets a specific flag */
 283 int fcntl_setfl(int fd, int flag)
 284 {
 285     int flags;
 286
 287     flags = fcntl(fd, F_GETFL);
 288     if (flags == -1)
 289         return -errno;
 290
 291     if (fcntl(fd, F_SETFL, flags | flag) == -1)
 292         return -errno;
 293
 294     return 0;
 295 }
 296 #endif
 297
 298 static int64_t suffix_mul(char suffix, int64_t unit)
 299 {
 300     switch (qemu_toupper(suffix)) {
 301     case STRTOSZ_DEFSUFFIX_B:
 302         return 1;
 303     case STRTOSZ_DEFSUFFIX_KB:
 304         return unit;
 305     case STRTOSZ_DEFSUFFIX_MB:
 306         return unit * unit;
 307     case STRTOSZ_DEFSUFFIX_GB:
 308         return unit * unit * unit;
 309     case STRTOSZ_DEFSUFFIX_TB:
 310         return unit * unit * unit * unit;
 311     }
 312     return -1;
 313 }
 314
 315 /*
 316  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
 317  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
 318  * in *end, if not NULL. Return -1 on error.
 319  */
 320 int64_t strtosz_suffix_unit(const char *nptr, char **end,
 321                             const char default_suffix, int64_t unit)
 322 {
 323     int64_t retval = -1;
 324     char *endptr;
 325     unsigned char c;
 326     int mul_required = 0;
 327     double val, mul, integral, fraction;
 328
 329     errno = 0;
 330     val = strtod(nptr, &endptr);
 331     if (isnan(val) || endptr == nptr || errno != 0) {
 332         goto fail;
 333     }
 334     fraction = modf(val, &integral);
 335     if (fraction != 0) {
 336         mul_required = 1;
 337     }
 338     c = *endptr;
 339     mul = suffix_mul(c, unit);
 340     if (mul >= 0) {
 341         endptr++;
 342     } else {
 343         mul = suffix_mul(default_suffix, unit);
 344         assert(mul >= 0);
 345     }
 346     if (mul == 1 && mul_required) {
 347         goto fail;
 348     }
 349     if ((val * mul >= INT64_MAX) || val < 0) {
 350         goto fail;
 351     }
 352     retval = val * mul;
 353
 354 fail:
 355     if (end) {
 356         *end = endptr;
 357     }
 358
 359     return retval;
 360 }
 361
 362 int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
 363 {
 364     return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
 365 }
 366
 367 int64_t strtosz(const char *nptr, char **end)
 368 {
 369     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
 370 }
 371
 372 int qemu_parse_fd(const char *param)
 373 {
 374     int fd;
 375     char *endptr = NULL;
 376
 377     fd = strtol(param, &endptr, 10);
 378     if (*endptr || (fd == 0 && param == endptr)) {
 379         return -1;
 380     }
 381     return fd;
 382 }
 383
 384 /*
 385  * Send/recv data with iovec buffers
 386  *
 387  * This function send/recv data from/to the iovec buffer directly.
 388  * The first `offset' bytes in the iovec buffer are skipped and next
 389  * `len' bytes are used.
 390  *
 391  * For example,
 392  *
 393  *   do_sendv_recvv(sockfd, iov, len, offset, 1);
 394  *
 395  * is equal to
 396  *
 397  *   char *buf = malloc(size);
 398  *   iov_to_buf(iov, iovcnt, buf, offset, size);
 399  *   send(sockfd, buf, size, 0);
 400  *   free(buf);
 401  */
 402 static int do_sendv_recvv(int sockfd, struct iovec *iov, int len, int offset,
 403                           int do_sendv)
 404 {
 405     int ret, diff, iovlen;
 406     struct iovec *last_iov;
 407
 408     /* last_iov is inclusive, so count from one.  */
 409     iovlen = 1;
 410     last_iov = iov;
 411     len += offset;
 412
 413     while (last_iov->iov_len < len) {
 414         len -= last_iov->iov_len;
 415
 416         last_iov++;
 417         iovlen++;
 418     }
 419
 420     diff = last_iov->iov_len - len;
 421     last_iov->iov_len -= diff;
 422
 423     while (iov->iov_len <= offset) {
 424         offset -= iov->iov_len;
 425
 426         iov++;
 427         iovlen--;
 428     }
 429
 430     iov->iov_base = (char *) iov->iov_base + offset;
 431     iov->iov_len -= offset;
 432
 433     {
 434 #if defined CONFIG_IOVEC && defined CONFIG_POSIX
 435         struct msghdr msg;
 436         memset(&msg, 0, sizeof(msg));
 437         msg.msg_iov = iov;
 438         msg.msg_iovlen = iovlen;
 439
 440         do {
 441             if (do_sendv) {
 442                 ret = sendmsg(sockfd, &msg, 0);
 443             } else {
 444                 ret = recvmsg(sockfd, &msg, 0);
 445             }
 446         } while (ret == -1 && errno == EINTR);
 447 #else
 448         struct iovec *p = iov;
 449         ret = 0;
 450         while (iovlen > 0) {
 451             int rc;
 452             if (do_sendv) {
 453                 rc = send(sockfd, p->iov_base, p->iov_len, 0);
 454             } else {
 455                 rc = qemu_recv(sockfd, p->iov_base, p->iov_len, 0);
 456             }
 457             if (rc == -1) {
 458                 if (errno == EINTR) {
 459                     continue;
 460                 }
 461                 if (ret == 0) {
 462                     ret = -1;
 463                 }
 464                 break;
 465             }
 466             if (rc == 0) {
 467                 break;
 468             }
 469             ret += rc;
 470             iovlen--, p++;
 471         }
 472 #endif
 473     }
 474
 475     /* Undo the changes above */
 476     iov->iov_base = (char *) iov->iov_base - offset;
 477     iov->iov_len += offset;
 478     last_iov->iov_len += diff;
 479     return ret;
 480 }
 481
 482 int qemu_recvv(int sockfd, struct iovec *iov, int len, int iov_offset)
 483 {
 484     return do_sendv_recvv(sockfd, iov, len, iov_offset, 0);
 485 }
 486
 487 int qemu_sendv(int sockfd, struct iovec *iov, int len, int iov_offset)
 488 {
 489     return do_sendv_recvv(sockfd, iov, len, iov_offset, 1);
 490 }
 491