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      1 /******************************************************************************
      2  *
      3  *  Copyright 2015 Google, Inc.
      4  *
      5  *  Licensed under the Apache License, Version 2.0 (the "License");
      6  *  you may not use this file except in compliance with the License.
      7  *  You may obtain a copy of the License at:
      8  *
      9  *  http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  *  Unless required by applicable law or agreed to in writing, software
     12  *  distributed under the License is distributed on an "AS IS" BASIS,
     13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  *  See the License for the specific language governing permissions and
     15  *  limitations under the License.
     16  *
     17  ******************************************************************************/
     18 
     19 /************************************************************************************
     20  *
     21  *  Filename:      compat.c
     22  *
     23  *  Description:   Compatibility functions for non-bionic C libraries
     24  *
     25  *
     26  ***********************************************************************************/
     27 
     28 #include <features.h>
     29 #include <string.h>
     30 #include <sys/syscall.h>
     31 #include <sys/types.h>
     32 #include <unistd.h>
     33 
     34 #include "osi/include/compat.h"
     35 #include "osi/include/osi.h"
     36 
     37 #if __GLIBC__
     38 pid_t
     39 gettid(void)
     40 {
     41   return syscall(SYS_gettid);
     42 }
     43 #endif
     44 
     45 /* These functions from bionic
     46  *
     47  * Copyright (c) 1998 Todd C. Miller <Todd.Miller (at) courtesan.com>
     48  *
     49  * Permission to use, copy, modify, and distribute this software for any
     50  * purpose with or without fee is hereby granted, provided that the above
     51  * copyright notice and this permission notice appear in all copies.
     52  *
     53  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     54  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     55  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     56  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     57  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     58  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     59  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     60  */
     61 
     62 #if __GLIBC__
     63 /*
     64  * Copy src to string dst of size siz.  At most siz-1 characters
     65  * will be copied.  Always NUL terminates (unless siz == 0).
     66  * Returns strlen(src); if retval >= siz, truncation occurred.
     67  */
     68 size_t
     69 strlcpy(char *dst, const char *src, size_t siz)
     70 {
     71   char *d = dst;
     72   const char *s = src;
     73   size_t n = siz;
     74 
     75   /* Copy as many bytes as will fit */
     76   if (n != 0) {
     77     while (--n != 0) {
     78       if ((*d++ = *s++) == '\0')
     79         break;
     80     }
     81   }
     82 
     83   /* Not enough room in dst, add NUL and traverse rest of src */
     84   if (n == 0) {
     85     if (siz != 0)
     86       *d = '\0'; /* NUL-terminate dst */
     87     while (*s++)
     88       ;
     89   }
     90 
     91   return(s - src - 1); /* count does not include NUL */
     92 }
     93 #endif
     94 
     95 #if __GLIBC__
     96 /*
     97  * Appends src to string dst of size siz (unlike strncat, siz is the
     98  * full size of dst, not space left).  At most siz-1 characters
     99  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
    100  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
    101  * If retval >= siz, truncation occurred.
    102  */
    103 size_t
    104 strlcat(char *dst, const char *src, size_t siz)
    105 {
    106   char *d = dst;
    107   const char *s = src;
    108   size_t n = siz;
    109   size_t dlen;
    110 
    111   /* Find the end of dst and adjust bytes left but don't go past end */
    112   while (n-- != 0 && *d != '\0')
    113     d++;
    114   dlen = d - dst;
    115   n = siz - dlen;
    116 
    117   if (n == 0)
    118     return (dlen + strlen(s));
    119 
    120   while (*s != '\0') {
    121     if (n != 1) {
    122       *d++ = *s;
    123       n--;
    124     }
    125 
    126     s++;
    127   }
    128 
    129   *d = '\0';
    130 
    131   return (dlen + (s - src)); /* count does not include NUL */
    132 }
    133 #endif
    134