[ee122] file permissions and file handling

[Daniel Killebrew]

Davide Cerri wrote:
> Hello,
> I thought to use stat to check for the file information, but the man page show
>
> #define S_IFMT 0170000           /* type of file */
>      #define        S_IFIFO  0010000  /* named pipe (fifo) */
>      #define        S_IFCHR  0020000  /* character special */
>      #define        S_IFDIR  0040000  /* directory */
>      #define        S_IFBLK  0060000  /* block special */
>      #define        S_IFREG  0100000  /* regular */
>      #define        S_IFLNK  0120000  /* symbolic link */
>      #define        S_IFSOCK 0140000  /* socket */
>      #define        S_IFWHT  0160000  /* whiteout */
>      #define S_ISUID 0004000  /* set user id on execution */
>      #define S_ISGID 0002000  /* set group id on execution */
>      #define S_ISVTX 0001000  /* save swapped text even after use */
>      #define S_IRUSR 0000400  /* read permission, owner */
>      #define S_IWUSR 0000200  /* write permission, owner */
>      #define S_IXUSR 0000100  /* execute/search permission, owner */
>
> How can we check for world access?
> I am assuming that we are allowed to send only world readable files to
> the clients.
>   
If I (ee122-tb) am executing your http_server, it will be running under 
my permissions. So it should be able to send out any files that ee122-tb 
can read. So the answer is no, it should send files that it is allowed 
to read. Unix will enforce the filesystem permissions. You need to 
determine whether to send a
403 Forbidden
or
404 Not Found
error to the client.
> Also? the specs says that we only look for files starting from the web
> server directory?
> any hint on how to handle that? should we calculate that by parsing
> the path and checking for ../ occurrences?
>   
That might work... Note that just counting the number of ../ occurrences 
is not quite a correct solution. As to why, I leave that to you to 
determine :)

Daniel

> thanks,
>
>
>