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       1                 :             : #include "precizer.h"
       2                 :             : #include <errno.h>
       3                 :             : 
       4                 :             : /**
       5                 :             :  * @brief Check access to a path using an open directory as its base
       6                 :             :  *
       7                 :             :  * @details
       8                 :             :  * Passes the supplied path to `faccessat()` without changing the process
       9                 :             :  * working directory or constructing an absolute path. A relative path is
      10                 :             :  * resolved from @p directory_fd. As specified by `faccessat()`, an absolute
      11                 :             :  * path is resolved independently and causes @p directory_fd to be ignored
      12                 :             :  *
      13                 :             :  * The function uses the process real user and group IDs, matching `access()`
      14                 :             :  * semantics. A successful check returns `FILE_ACCESS_ALLOWED`; a failed check
      15                 :             :  * is translated from `errno` into the corresponding `FileAccessStatus`
      16                 :             :  *
      17                 :             :  * @param[in] directory_fd File descriptor used as the base for a relative path
      18                 :             :  * @param[in] relative_path String memory descriptor whose text is passed to
      19                 :             :  *            `faccessat()`. Callers that require root confinement must ensure
      20                 :             :  *            that this value is relative
      21                 :             :  * @param[in] mode Access mode such as `F_OK`, `R_OK`, `W_OK`, or `X_OK`
      22                 :             :  * @return `FILE_ACCESS_ALLOWED`, `FILE_ACCESS_DENIED`, `FILE_NOT_FOUND`, or
      23                 :             :  *         `FILE_ACCESS_ERROR`. A NULL path descriptor returns
      24                 :             :  *         `FILE_ACCESS_ERROR`
      25                 :             :  */
      26                 :       20348 : FileAccessStatus file_check_access(
      27                 :             :         const int    directory_fd,
      28                 :             :         const memory *relative_path,
      29                 :             :         const int    mode)
      30                 :             : {
      31         [ -  + ]:       20348 :         if(relative_path == NULL)
      32                 :             :         {
      33                 :           0 :                 return(FILE_ACCESS_ERROR);
      34                 :             :         }
      35                 :             : 
      36                 :       20348 :         const char *runtime_relative_path = m_text(relative_path);
      37                 :             : 
      38                 :             : #ifdef TESTITALL_TEST_HOOKS
      39                 :       20348 :         FileAccessStatus forced_status = FILE_ACCESS_ALLOWED;
      40                 :             : 
      41         [ +  + ]:       20348 :         if(testitall_file_access_status_override(runtime_relative_path,&forced_status) == true)
      42                 :             :         {
      43                 :          31 :                 return(forced_status);
      44                 :             :         }
      45                 :             : #endif
      46                 :             : 
      47         [ +  + ]:       20317 :         if(faccessat(directory_fd,runtime_relative_path,mode,0) == 0)
      48                 :             :         {
      49                 :       20255 :                 return(FILE_ACCESS_ALLOWED);
      50                 :             :         }
      51                 :             : 
      52                 :          62 :         return(file_access_status(errno));
      53                 :             : }