coregrind/m_libcfile.c

/*--------------------------------------------------------------------*/
/*--- File- and socket-related libc stuff.            m_libcfile.c ---*/
/*--------------------------------------------------------------------*/
 
/*
   This file is part of Valgrind, a dynamic binary instrumentation
   framework.

   Copyright (C) 2000-2005 Julian Seward 
      jseward@acm.org

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307, USA.

   The GNU General Public License is contained in the file COPYING.
*/

#include "pub_core_basics.h"
#include "pub_core_libcbase.h"
#include "pub_core_libcassert.h"
#include "pub_core_libcfile.h"
#include "pub_core_libcprint.h"     // VG_(sprintf)
#include "pub_core_libcproc.h"      // VG_(getpid), VG_(getppid)
#include "pub_core_clientstate.h"   // VG_(fd_hard_limit)
#include "pub_core_syscall.h"
#include "vki_unistd.h"

/* ---------------------------------------------------------------------
   File stuff
   ------------------------------------------------------------------ */

static inline Bool fd_exists(Int fd)
{
   struct vki_stat st;

   return VG_(fstat)(fd, &st) == 0;
}

/* Move an fd into the Valgrind-safe range */
Int VG_(safe_fd)(Int oldfd)
{
   Int newfd;

   vg_assert(VG_(fd_hard_limit) != -1);

   newfd = VG_(fcntl)(oldfd, VKI_F_DUPFD, VG_(fd_hard_limit));
   if (newfd != -1)
      VG_(close)(oldfd);

   VG_(fcntl)(newfd, VKI_F_SETFD, VKI_FD_CLOEXEC);

   vg_assert(newfd >= VG_(fd_hard_limit));
   return newfd;
}

/* Given a file descriptor, attempt to deduce its filename.  To do
   this, we use /proc/self/fd/<FD>.  If this doesn't point to a file,
   or if it doesn't exist, we return False. */
Bool VG_(resolve_filename) ( Int fd, HChar* buf, Int n_buf )
{
   HChar tmp[64];

   VG_(sprintf)(tmp, "/proc/self/fd/%d", fd);
   VG_(memset)(buf, 0, n_buf);

   if (VG_(readlink)(tmp, buf, n_buf) > 0 && buf[0] == '/')
      return True;
   else
      return False;
}

SysRes VG_(open) ( const Char* pathname, Int flags, Int mode )
{  
   SysRes res = VG_(do_syscall3)(__NR_open, (UWord)pathname, flags, mode);
   return res;
}

void VG_(close) ( Int fd )
{
   (void)VG_(do_syscall1)(__NR_close, fd);
}

Int VG_(read) ( Int fd, void* buf, Int count)
{
   SysRes res = VG_(do_syscall3)(__NR_read, fd, (UWord)buf, count);
   return res.isError ? -1 : res.val;
}

Int VG_(write) ( Int fd, const void* buf, Int count)
{
   SysRes res = VG_(do_syscall3)(__NR_write, fd, (UWord)buf, count);
   return res.isError ? -1 : res.val;
}

Int VG_(pipe) ( Int fd[2] )
{
   SysRes res = VG_(do_syscall1)(__NR_pipe, (UWord)fd);
   return res.isError ? -1 : 0;
}

OffT VG_(lseek) ( Int fd, OffT offset, Int whence )
{
   SysRes res = VG_(do_syscall3)(__NR_lseek, fd, offset, whence);
   return res.isError ? (-1) : 0;
   /* if you change the error-reporting conventions of this, also
      change VG_(pread) and all other usage points. */
}

SysRes VG_(stat) ( Char* file_name, struct vki_stat* buf )
{
   SysRes res = VG_(do_syscall2)(__NR_stat, (UWord)file_name, (UWord)buf);
   return res;
}

Int VG_(fstat) ( Int fd, struct vki_stat* buf )
{
   SysRes res = VG_(do_syscall2)(__NR_fstat, fd, (UWord)buf);
   return res.isError ? (-1) : 0;
}

Int VG_(fsize) ( Int fd )
{
   struct vki_stat buf;
   SysRes res = VG_(do_syscall2)(__NR_fstat, fd, (UWord)&buf);
   return res.isError ? (-1) : buf.st_size;
}

SysRes VG_(dup) ( Int oldfd )
{
   return VG_(do_syscall1)(__NR_dup, oldfd);
}

/* Returns -1 on error. */
Int VG_(fcntl) ( Int fd, Int cmd, Int arg )
{
   SysRes res = VG_(do_syscall3)(__NR_fcntl, fd, cmd, arg);
   return res.isError ? -1 : res.val;
}

Int VG_(rename) ( Char* old_name, Char* new_name )
{
   SysRes res = VG_(do_syscall2)(__NR_rename, (UWord)old_name, (UWord)new_name);
   return res.isError ? (-1) : 0;
}

Int VG_(unlink) ( Char* file_name )
{
   SysRes res = VG_(do_syscall1)(__NR_unlink, (UWord)file_name);
   return res.isError ? (-1) : 0;
}

/* Nb: we do not allow the Linux extension which malloc()s memory for the
   buffer if buf==NULL, because we don't want Linux calling malloc() */
Bool VG_(getcwd) ( Char* buf, SizeT size )
{
   SysRes res;
   vg_assert(buf != NULL);
   res = VG_(do_syscall2)(__NR_getcwd, (UWord)buf, size);
   return res.isError ? False : True;
}

Int VG_(readlink) (Char* path, Char* buf, UInt bufsiz)
{
   SysRes res;
   /* res = readlink( path, buf, bufsiz ); */
   res = VG_(do_syscall3)(__NR_readlink, (UWord)path, (UWord)buf, bufsiz);
   return res.isError ? -1 : res.val;
}

Int VG_(getdents) (UInt fd, struct vki_dirent *dirp, UInt count)
{
   SysRes res;
   /* res = getdents( fd, dirp, count ); */
   res = VG_(do_syscall3)(__NR_getdents, fd, (UWord)dirp, count);
   return res.isError ? -1 : res.val;
}

/* Check accessibility of a file.  Returns zero for access granted,
   nonzero otherwise. */
Int VG_(access) ( HChar* path, Bool irusr, Bool iwusr, Bool ixusr )
{
#if defined(VGO_linux)
   /* Very annoyingly, I cannot find any definition for R_OK et al in
      the kernel interfaces.  Therefore I reluctantly resort to
      hardwiring in these magic numbers that I determined by
      experimentation. */
   UWord w = (irusr ? 4/*R_OK*/ : 0)
             | (iwusr ? 2/*W_OK*/ : 0)
             | (ixusr ? 1/*X_OK*/ : 0);
   SysRes res = VG_(do_syscall2)(__NR_access, (UWord)path, w);
   return res.isError ? 1 : res.val;
#else
#  error "Don't know how to do VG_(access) on this OS"
#endif
}

SysRes VG_(pread) ( Int fd, void* buf, Int count, Int offset )
{
   OffT off = VG_(lseek)( fd, (OffT)offset, VKI_SEEK_SET);
   if (off != 0)
      return VG_(mk_SysRes_Error)( VKI_EINVAL );
   return VG_(do_syscall3)(__NR_read, fd, (UWord)buf, count );
}

/* Create and open (-rw------) a tmp file name incorporating said arg.
   Returns -1 on failure, else the fd of the file.  If fullname is
   non-NULL, the file's name is written into it.  The number of bytes
   written is guaranteed not to exceed 64+strlen(part_of_name). */

Int VG_(mkstemp) ( HChar* part_of_name, /*OUT*/HChar* fullname )
{
   HChar  buf[200];
   Int    n, tries, fd;
   UInt   seed;
   SysRes sres;

   vg_assert(part_of_name);
   n = VG_(strlen)(part_of_name);
   vg_assert(n > 0 && n < 100);

   seed = (VG_(getpid)() << 9) ^ VG_(getppid)();

   tries = 0;
   while (True) {
      if (tries > 10) 
         return -1;
      VG_(sprintf)( buf, "/tmp/valgrind_%s_%08x", 
                         part_of_name, VG_(random)( &seed ));
      if (0)
         VG_(printf)("VG_(mkstemp): trying: %s\n", buf);

      sres = VG_(open)(buf,
                       VKI_O_CREAT|VKI_O_RDWR|VKI_O_EXCL|VKI_O_TRUNC,
                       VKI_S_IRUSR|VKI_S_IWUSR);
      if (sres.isError)
         continue;
      /* VG_(safe_fd) doesn't return if it fails. */
      fd = VG_(safe_fd)( sres.val );
      if (fullname)
         VG_(strcpy)( fullname, buf );
      return fd;
   }
   /* NOTREACHED */
}


/* ---------------------------------------------------------------------
   Socket-related stuff.  This is very Linux-kernel specific.
   ------------------------------------------------------------------ */

static
Int parse_inet_addr_and_port ( UChar* str, UInt* ip_addr, UShort* port );

static
Int my_socket ( Int domain, Int type, Int protocol );

static
Int my_connect ( Int sockfd, struct vki_sockaddr_in* serv_addr, 
                 Int addrlen );

static 
UInt my_htonl ( UInt x )
{
   return
      (((x >> 24) & 0xFF) << 0) | (((x >> 16) & 0xFF) << 8)
      | (((x >> 8) & 0xFF) << 16) | (((x >> 0) & 0xFF) << 24);
}

static
UShort my_htons ( UShort x )
{
   return
      (((x >> 8) & 0xFF) << 0) | (((x >> 0) & 0xFF) << 8);
}


/* The main function. 

   Supplied string contains either an ip address "192.168.0.1" or
   an ip address and port pair, "192.168.0.1:1500".  Parse these,
   and return:
     -1 if there is a parse error
     -2 if no parse error, but specified host:port cannot be opened
     the relevant file (socket) descriptor, otherwise.
 is used.
*/
Int VG_(connect_via_socket)( UChar* str )
{
   Int sd, res;
   struct vki_sockaddr_in servAddr;
   UInt   ip   = 0;
   UShort port = VG_CLO_DEFAULT_LOGPORT;
   Bool   ok   = parse_inet_addr_and_port(str, &ip, &port);
   if (!ok) 
      return -1;

   //if (0)
   //   VG_(printf)("ip = %d.%d.%d.%d, port %d\n",
   //               (ip >> 24) & 0xFF, (ip >> 16) & 0xFF, 
   //               (ip >> 8) & 0xFF, ip & 0xFF, 
   //               (UInt)port );

   servAddr.sin_family = VKI_AF_INET;
   servAddr.sin_addr.s_addr = my_htonl(ip);
   servAddr.sin_port = my_htons(port);

   /* create socket */
   sd = my_socket(VKI_AF_INET, VKI_SOCK_STREAM, 0 /* IPPROTO_IP ? */);
   if (sd < 0) {
     /* this shouldn't happen ... nevertheless */
     return -2;
   }
			
   /* connect to server */
   res = my_connect(sd, (struct vki_sockaddr_in *) &servAddr, 
                        sizeof(servAddr));
   if (res < 0) {
     /* connection failed */
     return -2;
   }

   return sd;
}


/* Let d = one or more digits.  Accept either:
   d.d.d.d  or  d.d.d.d:d
*/
Int parse_inet_addr_and_port ( UChar* str, UInt* ip_addr, UShort* port )
{
#  define GET_CH ((*str) ? (*str++) : 0)
   UInt ipa, i, j, c, any;
   ipa = 0;
   for (i = 0; i < 4; i++) {
      j = 0;
      any = 0;
      while (1) {
         c = GET_CH; 
         if (c < '0' || c > '9') break;
         j = 10 * j + (int)(c - '0');
         any = 1;
      }
      if (any == 0 || j > 255) goto syntaxerr;
      ipa = (ipa << 8) + j;
      if (i <= 2 && c != '.') goto syntaxerr;
   }
   if (c == 0 || c == ':') 
      *ip_addr = ipa;
   if (c == 0) goto ok;
   if (c != ':') goto syntaxerr;
   j = 0;
   any = 0;
   while (1) {
      c = GET_CH; 
      if (c < '0' || c > '9') break;
      j = j * 10 + (int)(c - '0');
      any = 1;
      if (j > 65535) goto syntaxerr;
   }
   if (any == 0 || c != 0) goto syntaxerr;
   if (j < 1024) goto syntaxerr;
   *port = (UShort)j;
 ok:
   return 1;
 syntaxerr:
   return 0;
#  undef GET_CH
}

static
Int my_socket ( Int domain, Int type, Int protocol )
{
#if defined(VGP_x86_linux) || defined(VGP_ppc32_linux)
   SysRes res;
   UWord  args[3];
   args[0] = domain;
   args[1] = type;
   args[2] = protocol;
   res = VG_(do_syscall2)(__NR_socketcall, VKI_SYS_SOCKET, (UWord)&args);
   return res.isError ? -1 : res.val;

#elif defined(VGP_amd64_linux)
   SysRes res;
   res = VG_(do_syscall3)(__NR_socket, domain, type, protocol );
   return res.isError ? -1 : res.val;

#else
#  error Unknown arch
#endif
}

static
Int my_connect ( Int sockfd, struct vki_sockaddr_in* serv_addr, 
                 Int addrlen )
{
#if defined(VGP_x86_linux) || defined(VGP_ppc32_linux)
   SysRes res;
   UWord  args[3];
   args[0] = sockfd;
   args[1] = (UWord)serv_addr;
   args[2] = addrlen;
   res = VG_(do_syscall2)(__NR_socketcall, VKI_SYS_CONNECT, (UWord)&args);
   return res.isError ? -1 : res.val;

#elif defined(VGP_amd64_linux)
   SysRes res;
   res = VG_(do_syscall3)(__NR_connect, sockfd, (UWord)serv_addr, addrlen);
   return res.isError ? -1 : res.val;

#else
#  error Unknown arch
#endif
}

Int VG_(write_socket)( Int sd, void *msg, Int count )
{
   /* This is actually send(). */
   /* Requests not to send SIGPIPE on errors on stream oriented
      sockets when the other end breaks the connection. The EPIPE
      error is still returned. */
   Int flags = VKI_MSG_NOSIGNAL;

#if defined(VGP_x86_linux)
   SysRes res;
   UWord  args[4];
   args[0] = sd;
   args[1] = (UWord)msg;
   args[2] = count;
   args[3] = flags;
   res = VG_(do_syscall2)(__NR_socketcall, VKI_SYS_SEND, (UWord)&args);
   return res.isError ? -1 : res.val;

#elif defined(VGP_amd64_linux)
   SysRes res;
   res = VG_(do_syscall6)(__NR_sendto, sd, (UWord)msg, count, flags, 0,0);
   return res.isError ? -1 : res.val;

#elif defined(VGP_ppc32_linux)
   //CAB: TODO
   I_die_here;
   flags = 0; // stop compiler complaints

#else
#  error Unknown arch
#endif
}

Int VG_(getsockname) ( Int sd, struct vki_sockaddr *name, Int *namelen)
{
   SysRes res;

#if defined(VGP_x86_linux) || defined(VGP_ppc32_linux)
   UWord  args[3];
   args[0] = sd;
   args[1] = (UWord)name;
   args[2] = (UWord)namelen;
   res = VG_(do_syscall2)(__NR_socketcall, VKI_SYS_GETSOCKNAME, (UWord)&args);
   return res.isError ? -1 : res.val;

#elif defined(VGP_amd64_linux)
   res = VG_(do_syscall3)( __NR_getsockname,
                           (UWord)sd, (UWord)name, (UWord)namelen );
   return res.isError ? -1 : res.val;

#else
#  error Unknown arch
#endif
}

Int VG_(getpeername) ( Int sd, struct vki_sockaddr *name, Int *namelen)
{
   SysRes res;

#if defined(VGP_x86_linux) || defined(VGP_ppc32_linux)
   UWord  args[3];
   args[0] = sd;
   args[1] = (UWord)name;
   args[2] = (UWord)namelen;
   res = VG_(do_syscall2)(__NR_socketcall, VKI_SYS_GETPEERNAME, (UWord)&args);
   return res.isError ? -1 : res.val;

#elif defined(VGP_amd64_linux)
   res = VG_(do_syscall3)( __NR_getpeername,
                           (UWord)sd, (UWord)name, (UWord)namelen );
   return res.isError ? -1 : res.val;

#else
#  error Unknown archx
#endif
}

Int VG_(getsockopt) ( Int sd, Int level, Int optname, void *optval,
                      Int *optlen)
{
   SysRes res;

#if defined(VGP_x86_linux) || defined(VGP_ppc32_linux)
   UWord  args[5];
   args[0] = sd;
   args[1] = level;
   args[2] = optname;
   args[3] = (UWord)optval;
   args[4] = (UWord)optlen;
   res = VG_(do_syscall2)(__NR_socketcall, VKI_SYS_GETSOCKOPT, (UWord)&args);
   return res.isError ? -1 : res.val;

#elif defined(VGP_amd64_linux)
   res = VG_(do_syscall5)( __NR_getsockopt,
                           (UWord)sd, (UWord)level, (UWord)optname, 
                           (UWord)optval, (UWord)optlen );
   return res.isError ? -1 : res.val;

#else
#  error Unknown arch
#endif
}



/*--------------------------------------------------------------------*/
/*--- end                                                          ---*/
/*--------------------------------------------------------------------*/