File:  [Qemu by Fabrice Bellard] / qemu / cutils.c
Revision 1.1.1.9 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 19:33:58 2018 UTC (3 years, 5 months ago) by root
Branches: qemu, MAIN
CVS tags: qemu1101, HEAD
qemu 1.1.1

    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: 
   30: void pstrcpy(char *buf, int buf_size, const char *str)
   31: {
   32:     int c;
   33:     char *q = buf;
   34: 
   35:     if (buf_size <= 0)
   36:         return;
   37: 
   38:     for(;;) {
   39:         c = *str++;
   40:         if (c == 0 || q >= buf + buf_size - 1)
   41:             break;
   42:         *q++ = c;
   43:     }
   44:     *q = '\0';
   45: }
   46: 
   47: /* strcat and truncate. */
   48: char *pstrcat(char *buf, int buf_size, const char *s)
   49: {
   50:     int len;
   51:     len = strlen(buf);
   52:     if (len < buf_size)
   53:         pstrcpy(buf + len, buf_size - len, s);
   54:     return buf;
   55: }
   56: 
   57: int strstart(const char *str, const char *val, const char **ptr)
   58: {
   59:     const char *p, *q;
   60:     p = str;
   61:     q = val;
   62:     while (*q != '\0') {
   63:         if (*p != *q)
   64:             return 0;
   65:         p++;
   66:         q++;
   67:     }
   68:     if (ptr)
   69:         *ptr = p;
   70:     return 1;
   71: }
   72: 
   73: int stristart(const char *str, const char *val, const char **ptr)
   74: {
   75:     const char *p, *q;
   76:     p = str;
   77:     q = val;
   78:     while (*q != '\0') {
   79:         if (qemu_toupper(*p) != qemu_toupper(*q))
   80:             return 0;
   81:         p++;
   82:         q++;
   83:     }
   84:     if (ptr)
   85:         *ptr = p;
   86:     return 1;
   87: }
   88: 
   89: /* XXX: use host strnlen if available ? */
   90: int qemu_strnlen(const char *s, int max_len)
   91: {
   92:     int i;
   93: 
   94:     for(i = 0; i < max_len; i++) {
   95:         if (s[i] == '\0') {
   96:             break;
   97:         }
   98:     }
   99:     return i;
  100: }
  101: 
  102: time_t mktimegm(struct tm *tm)
  103: {
  104:     time_t t;
  105:     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
  106:     if (m < 3) {
  107:         m += 12;
  108:         y--;
  109:     }
  110:     t = 86400 * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 + 
  111:                  y / 400 - 719469);
  112:     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
  113:     return t;
  114: }
  115: 
  116: int qemu_fls(int i)
  117: {
  118:     return 32 - clz32(i);
  119: }
  120: 
  121: /*
  122:  * Make sure data goes on disk, but if possible do not bother to
  123:  * write out the inode just for timestamp updates.
  124:  *
  125:  * Unfortunately even in 2009 many operating systems do not support
  126:  * fdatasync and have to fall back to fsync.
  127:  */
  128: int qemu_fdatasync(int fd)
  129: {
  130: #ifdef CONFIG_FDATASYNC
  131:     return fdatasync(fd);
  132: #else
  133:     return fsync(fd);
  134: #endif
  135: }
  136: 
  137: /* io vectors */
  138: 
  139: void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
  140: {
  141:     qiov->iov = g_malloc(alloc_hint * sizeof(struct iovec));
  142:     qiov->niov = 0;
  143:     qiov->nalloc = alloc_hint;
  144:     qiov->size = 0;
  145: }
  146: 
  147: void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov)
  148: {
  149:     int i;
  150: 
  151:     qiov->iov = iov;
  152:     qiov->niov = niov;
  153:     qiov->nalloc = -1;
  154:     qiov->size = 0;
  155:     for (i = 0; i < niov; i++)
  156:         qiov->size += iov[i].iov_len;
  157: }
  158: 
  159: void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
  160: {
  161:     assert(qiov->nalloc != -1);
  162: 
  163:     if (qiov->niov == qiov->nalloc) {
  164:         qiov->nalloc = 2 * qiov->nalloc + 1;
  165:         qiov->iov = g_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec));
  166:     }
  167:     qiov->iov[qiov->niov].iov_base = base;
  168:     qiov->iov[qiov->niov].iov_len = len;
  169:     qiov->size += len;
  170:     ++qiov->niov;
  171: }
  172: 
  173: /*
  174:  * Copies iovecs from src to the end of dst. It starts copying after skipping
  175:  * the given number of bytes in src and copies until src is completely copied
  176:  * or the total size of the copied iovec reaches size.The size of the last
  177:  * copied iovec is changed in order to fit the specified total size if it isn't
  178:  * a perfect fit already.
  179:  */
  180: void qemu_iovec_copy(QEMUIOVector *dst, QEMUIOVector *src, uint64_t skip,
  181:     size_t size)
  182: {
  183:     int i;
  184:     size_t done;
  185:     void *iov_base;
  186:     uint64_t iov_len;
  187: 
  188:     assert(dst->nalloc != -1);
  189: 
  190:     done = 0;
  191:     for (i = 0; (i < src->niov) && (done != size); i++) {
  192:         if (skip >= src->iov[i].iov_len) {
  193:             /* Skip the whole iov */
  194:             skip -= src->iov[i].iov_len;
  195:             continue;
  196:         } else {
  197:             /* Skip only part (or nothing) of the iov */
  198:             iov_base = (uint8_t*) src->iov[i].iov_base + skip;
  199:             iov_len = src->iov[i].iov_len - skip;
  200:             skip = 0;
  201:         }
  202: 
  203:         if (done + iov_len > size) {
  204:             qemu_iovec_add(dst, iov_base, size - done);
  205:             break;
  206:         } else {
  207:             qemu_iovec_add(dst, iov_base, iov_len);
  208:         }
  209:         done += iov_len;
  210:     }
  211: }
  212: 
  213: void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
  214: {
  215:     qemu_iovec_copy(dst, src, 0, size);
  216: }
  217: 
  218: void qemu_iovec_destroy(QEMUIOVector *qiov)
  219: {
  220:     assert(qiov->nalloc != -1);
  221: 
  222:     qemu_iovec_reset(qiov);
  223:     g_free(qiov->iov);
  224:     qiov->nalloc = 0;
  225:     qiov->iov = NULL;
  226: }
  227: 
  228: void qemu_iovec_reset(QEMUIOVector *qiov)
  229: {
  230:     assert(qiov->nalloc != -1);
  231: 
  232:     qiov->niov = 0;
  233:     qiov->size = 0;
  234: }
  235: 
  236: void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
  237: {
  238:     uint8_t *p = (uint8_t *)buf;
  239:     int i;
  240: 
  241:     for (i = 0; i < qiov->niov; ++i) {
  242:         memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
  243:         p += qiov->iov[i].iov_len;
  244:     }
  245: }
  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: void qemu_iovec_memset_skip(QEMUIOVector *qiov, int c, size_t count,
  276:                             size_t skip)
  277: {
  278:     int i;
  279:     size_t done;
  280:     void *iov_base;
  281:     uint64_t iov_len;
  282: 
  283:     done = 0;
  284:     for (i = 0; (i < qiov->niov) && (done != count); i++) {
  285:         if (skip >= qiov->iov[i].iov_len) {
  286:             /* Skip the whole iov */
  287:             skip -= qiov->iov[i].iov_len;
  288:             continue;
  289:         } else {
  290:             /* Skip only part (or nothing) of the iov */
  291:             iov_base = (uint8_t*) qiov->iov[i].iov_base + skip;
  292:             iov_len = qiov->iov[i].iov_len - skip;
  293:             skip = 0;
  294:         }
  295: 
  296:         if (done + iov_len > count) {
  297:             memset(iov_base, c, count - done);
  298:             break;
  299:         } else {
  300:             memset(iov_base, c, iov_len);
  301:         }
  302:         done += iov_len;
  303:     }
  304: }
  305: 
  306: /*
  307:  * Checks if a buffer is all zeroes
  308:  *
  309:  * Attention! The len must be a multiple of 4 * sizeof(long) due to
  310:  * restriction of optimizations in this function.
  311:  */
  312: bool buffer_is_zero(const void *buf, size_t len)
  313: {
  314:     /*
  315:      * Use long as the biggest available internal data type that fits into the
  316:      * CPU register and unroll the loop to smooth out the effect of memory
  317:      * latency.
  318:      */
  319: 
  320:     size_t i;
  321:     long d0, d1, d2, d3;
  322:     const long * const data = buf;
  323: 
  324:     assert(len % (4 * sizeof(long)) == 0);
  325:     len /= sizeof(long);
  326: 
  327:     for (i = 0; i < len; i += 4) {
  328:         d0 = data[i + 0];
  329:         d1 = data[i + 1];
  330:         d2 = data[i + 2];
  331:         d3 = data[i + 3];
  332: 
  333:         if (d0 || d1 || d2 || d3) {
  334:             return false;
  335:         }
  336:     }
  337: 
  338:     return true;
  339: }
  340: 
  341: #ifndef _WIN32
  342: /* Sets a specific flag */
  343: int fcntl_setfl(int fd, int flag)
  344: {
  345:     int flags;
  346: 
  347:     flags = fcntl(fd, F_GETFL);
  348:     if (flags == -1)
  349:         return -errno;
  350: 
  351:     if (fcntl(fd, F_SETFL, flags | flag) == -1)
  352:         return -errno;
  353: 
  354:     return 0;
  355: }
  356: #endif
  357: 
  358: static int64_t suffix_mul(char suffix, int64_t unit)
  359: {
  360:     switch (qemu_toupper(suffix)) {
  361:     case STRTOSZ_DEFSUFFIX_B:
  362:         return 1;
  363:     case STRTOSZ_DEFSUFFIX_KB:
  364:         return unit;
  365:     case STRTOSZ_DEFSUFFIX_MB:
  366:         return unit * unit;
  367:     case STRTOSZ_DEFSUFFIX_GB:
  368:         return unit * unit * unit;
  369:     case STRTOSZ_DEFSUFFIX_TB:
  370:         return unit * unit * unit * unit;
  371:     }
  372:     return -1;
  373: }
  374: 
  375: /*
  376:  * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
  377:  * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
  378:  * in *end, if not NULL. Return -1 on error.
  379:  */
  380: int64_t strtosz_suffix_unit(const char *nptr, char **end,
  381:                             const char default_suffix, int64_t unit)
  382: {
  383:     int64_t retval = -1;
  384:     char *endptr;
  385:     unsigned char c;
  386:     int mul_required = 0;
  387:     double val, mul, integral, fraction;
  388: 
  389:     errno = 0;
  390:     val = strtod(nptr, &endptr);
  391:     if (isnan(val) || endptr == nptr || errno != 0) {
  392:         goto fail;
  393:     }
  394:     fraction = modf(val, &integral);
  395:     if (fraction != 0) {
  396:         mul_required = 1;
  397:     }
  398:     c = *endptr;
  399:     mul = suffix_mul(c, unit);
  400:     if (mul >= 0) {
  401:         endptr++;
  402:     } else {
  403:         mul = suffix_mul(default_suffix, unit);
  404:         assert(mul >= 0);
  405:     }
  406:     if (mul == 1 && mul_required) {
  407:         goto fail;
  408:     }
  409:     if ((val * mul >= INT64_MAX) || val < 0) {
  410:         goto fail;
  411:     }
  412:     retval = val * mul;
  413: 
  414: fail:
  415:     if (end) {
  416:         *end = endptr;
  417:     }
  418: 
  419:     return retval;
  420: }
  421: 
  422: int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix)
  423: {
  424:     return strtosz_suffix_unit(nptr, end, default_suffix, 1024);
  425: }
  426: 
  427: int64_t strtosz(const char *nptr, char **end)
  428: {
  429:     return strtosz_suffix(nptr, end, STRTOSZ_DEFSUFFIX_MB);
  430: }
  431: 
  432: int qemu_parse_fd(const char *param)
  433: {
  434:     int fd;
  435:     char *endptr = NULL;
  436: 
  437:     fd = strtol(param, &endptr, 10);
  438:     if (*endptr || (fd == 0 && param == endptr)) {
  439:         return -1;
  440:     }
  441:     return fd;
  442: }
  443: 
  444: /*
  445:  * Send/recv data with iovec buffers
  446:  *
  447:  * This function send/recv data from/to the iovec buffer directly.
  448:  * The first `offset' bytes in the iovec buffer are skipped and next
  449:  * `len' bytes are used.
  450:  *
  451:  * For example,
  452:  *
  453:  *   do_sendv_recvv(sockfd, iov, len, offset, 1);
  454:  *
  455:  * is equal to
  456:  *
  457:  *   char *buf = malloc(size);
  458:  *   iov_to_buf(iov, iovcnt, buf, offset, size);
  459:  *   send(sockfd, buf, size, 0);
  460:  *   free(buf);
  461:  */
  462: static int do_sendv_recvv(int sockfd, struct iovec *iov, int len, int offset,
  463:                           int do_sendv)
  464: {
  465:     int ret, diff, iovlen;
  466:     struct iovec *last_iov;
  467: 
  468:     /* last_iov is inclusive, so count from one.  */
  469:     iovlen = 1;
  470:     last_iov = iov;
  471:     len += offset;
  472: 
  473:     while (last_iov->iov_len < len) {
  474:         len -= last_iov->iov_len;
  475: 
  476:         last_iov++;
  477:         iovlen++;
  478:     }
  479: 
  480:     diff = last_iov->iov_len - len;
  481:     last_iov->iov_len -= diff;
  482: 
  483:     while (iov->iov_len <= offset) {
  484:         offset -= iov->iov_len;
  485: 
  486:         iov++;
  487:         iovlen--;
  488:     }
  489: 
  490:     iov->iov_base = (char *) iov->iov_base + offset;
  491:     iov->iov_len -= offset;
  492: 
  493:     {
  494: #if defined CONFIG_IOVEC && defined CONFIG_POSIX
  495:         struct msghdr msg;
  496:         memset(&msg, 0, sizeof(msg));
  497:         msg.msg_iov = iov;
  498:         msg.msg_iovlen = iovlen;
  499: 
  500:         do {
  501:             if (do_sendv) {
  502:                 ret = sendmsg(sockfd, &msg, 0);
  503:             } else {
  504:                 ret = recvmsg(sockfd, &msg, 0);
  505:             }
  506:         } while (ret == -1 && errno == EINTR);
  507: #else
  508:         struct iovec *p = iov;
  509:         ret = 0;
  510:         while (iovlen > 0) {
  511:             int rc;
  512:             if (do_sendv) {
  513:                 rc = send(sockfd, p->iov_base, p->iov_len, 0);
  514:             } else {
  515:                 rc = qemu_recv(sockfd, p->iov_base, p->iov_len, 0);
  516:             }
  517:             if (rc == -1) {
  518:                 if (errno == EINTR) {
  519:                     continue;
  520:                 }
  521:                 if (ret == 0) {
  522:                     ret = -1;
  523:                 }
  524:                 break;
  525:             }
  526:             if (rc == 0) {
  527:                 break;
  528:             }
  529:             ret += rc;
  530:             iovlen--, p++;
  531:         }
  532: #endif
  533:     }
  534: 
  535:     /* Undo the changes above */
  536:     iov->iov_base = (char *) iov->iov_base - offset;
  537:     iov->iov_len += offset;
  538:     last_iov->iov_len += diff;
  539:     return ret;
  540: }
  541: 
  542: int qemu_recvv(int sockfd, struct iovec *iov, int len, int iov_offset)
  543: {
  544:     return do_sendv_recvv(sockfd, iov, len, iov_offset, 0);
  545: }
  546: 
  547: int qemu_sendv(int sockfd, struct iovec *iov, int len, int iov_offset)
  548: {
  549:     return do_sendv_recvv(sockfd, iov, len, iov_offset, 1);
  550: }
  551: 

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