More CD fixes

[apt.git] / apt-pkg / contrib / fileutl.cc

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index b5cdf782b064808ff430268e53a8b5c124445f12..65c19ea920d4bd989e3aeff75c196ca42e5e4175 100644 (file)
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -1,6 +1,6 @@
 // -*- mode: cpp; mode: fold -*-
 // Description                                                         /*{{{*/
 // -*- mode: cpp; mode: fold -*-
 // Description                                                         /*{{{*/

-// $Id: fileutl.cc,v 1.15 1998/11/27 01:14:08 jgg Exp $
+// $Id: fileutl.cc,v 1.34 2000/01/17 07:11:49 jgg Exp $

 /* ######################################################################
    
    File Utilities
 /* ######################################################################
    
    File Utilities


@@ -21,9 +21,13 @@
 #include <apt-pkg/error.h>
 
 #include <unistd.h>
 #include <apt-pkg/error.h>
 
 #include <unistd.h>

+#include <fcntl.h>

 #include <sys/stat.h>
 #include <sys/stat.h>

-#include <sys/fcntl.h>

 #include <sys/types.h>
 #include <sys/types.h>

+#include <sys/time.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <errno.h>

                                                                        /*}}}*/
 
 // CopyFile - Buffered copy of a file                                  /*{{{*/
                                                                        /*}}}*/
 
 // CopyFile - Buffered copy of a file                                  /*{{{*/


@@ -36,14 +40,21 @@ bool CopyFile(FileFd &From,FileFd &To)
    
    // Buffered copy between fds
    unsigned char *Buf = new unsigned char[64000];
    
    // Buffered copy between fds
    unsigned char *Buf = new unsigned char[64000];

-   long Size;
-   while ((Size = read(From.Fd(),Buf,64000)) > 0)
+   unsigned long Size = From.Size();
+   while (Size != 0)

    {
    {

-      if (To.Write(Buf,Size) == false)
+      unsigned long ToRead = Size;
+      if (Size > 64000)
+        ToRead = 64000;
+      
+      if (From.Read(Buf,ToRead) == false || 
+         To.Write(Buf,ToRead) == false)

       {
         delete [] Buf;
         return false;
       }
       {
         delete [] Buf;
         return false;
       }

+      
+      Size -= ToRead;

    }
 
    delete [] Buf;
    }
 
    delete [] Buf;


@@ -68,12 +79,17 @@ int GetLock(string File,bool Errors)
    
    // Aquire a write lock
    struct flock fl;
    
    // Aquire a write lock
    struct flock fl;

-   fl.l_type= F_WRLCK;
-   fl.l_whence= SEEK_SET;
-   fl.l_start= 0;
-   fl.l_len= 1;
+   fl.l_type = F_WRLCK;
+   fl.l_whence = SEEK_SET;
+   fl.l_start = 0;
+   fl.l_len = 0;

    if (fcntl(FD,F_SETLK,&fl) == -1)
    {
    if (fcntl(FD,F_SETLK,&fl) == -1)
    {

+      if (errno == ENOLCK)
+      {
+        _error->Warning("Not using locking for nfs mounted lock file %s",File.c_str());
+        return true;
+      }      

       if (Errors == true)
         _error->Errno("open","Could not get lock %s",File.c_str());
       close(FD);
       if (Errors == true)
         _error->Errno("open","Could not get lock %s",File.c_str());
       close(FD);


@@ -102,8 +118,11 @@ string SafeGetCWD()
    // Stash the current dir.
    char S[300];
    S[0] = 0;
    // Stash the current dir.
    char S[300];
    S[0] = 0;

-   if (getcwd(S,sizeof(S)) == 0)
+   if (getcwd(S,sizeof(S)-2) == 0)

       return "/";
       return "/";

+   unsigned int Len = strlen(S);
+   S[Len] = '/';
+   S[Len+1] = 0;

    return S;
 }
                                                                        /*}}}*/
    return S;
 }
                                                                        /*}}}*/


@@ -131,6 +150,45 @@ string flNotFile(string File)
    return string(File,0,Res);
 }
                                                                        /*}}}*/
    return string(File,0,Res);
 }
                                                                        /*}}}*/

+// flNoLink - If file is a symlink then deref it                       /*{{{*/
+// ---------------------------------------------------------------------
+/* If the name is not a link then the returned path is the input. */
+string flNoLink(string File)
+{
+   struct stat St;
+   if (lstat(File.c_str(),&St) != 0 || S_ISLNK(St.st_mode) == 0)
+      return File;
+   if (stat(File.c_str(),&St) != 0)
+      return File;
+   
+   /* Loop resolving the link. There is no need to limit the number of 
+      loops because the stat call above ensures that the symlink is not 
+      circular */
+   char Buffer[1024];
+   string NFile = File;
+   while (1)
+   {
+      // Read the link
+      int Res;
+      if ((Res = readlink(NFile.c_str(),Buffer,sizeof(Buffer))) <= 0 || 
+         (unsigned)Res >= sizeof(Buffer))
+         return File;
+      
+      // Append or replace the previous path
+      Buffer[Res] = 0;
+      if (Buffer[0] == '/')
+        NFile = Buffer;
+      else
+        NFile = flNotFile(NFile) + Buffer;
+      
+      // See if we are done
+      if (lstat(NFile.c_str(),&St) != 0)
+        return File;
+      if (S_ISLNK(St.st_mode) == 0)
+        return NFile;      
+   }   
+}
+                                                                       /*}}}*/

 // SetCloseExec - Set the close on exec flag                           /*{{{*/
 // ---------------------------------------------------------------------
 /* */
 // SetCloseExec - Set the close on exec flag                           /*{{{*/
 // ---------------------------------------------------------------------
 /* */


@@ -159,25 +217,126 @@ void SetNonBlock(int Fd,bool Block)
 // WaitFd - Wait for a FD to become readable                           /*{{{*/
 // ---------------------------------------------------------------------
 /* This waits for a FD to become readable using select. It is usefull for
 // WaitFd - Wait for a FD to become readable                           /*{{{*/
 // ---------------------------------------------------------------------
 /* This waits for a FD to become readable using select. It is usefull for

-   applications making use of non-blocking sockets. */
-bool WaitFd(int Fd)
+   applications making use of non-blocking sockets. The timeout is 
+   in seconds. */
+bool WaitFd(int Fd,bool write,unsigned long timeout)

 {
    fd_set Set;
 {
    fd_set Set;

+   struct timeval tv;

    FD_ZERO(&Set);
    FD_SET(Fd,&Set);
    FD_ZERO(&Set);
    FD_SET(Fd,&Set);

+   tv.tv_sec = timeout;
+   tv.tv_usec = 0;
+   if (write == true) 
+   {      
+      int Res;
+      do
+      {
+        Res = select(Fd+1,0,&Set,0,(timeout != 0?&tv:0));
+      }
+      while (Res < 0 && errno == EINTR);
+      
+      if (Res <= 0)
+        return false;
+   } 
+   else 
+   {
+      int Res;
+      do
+      {
+        Res = select(Fd+1,&Set,0,0,(timeout != 0?&tv:0));
+      }
+      while (Res < 0 && errno == EINTR);
+      
+      if (Res <= 0)
+        return false;
+   }
+   
+   return true;
+}
+                                                                       /*}}}*/
+// ExecFork - Magical fork that sanitizes the context before execing   /*{{{*/
+// ---------------------------------------------------------------------
+/* This is used if you want to cleanse the environment for the forked 
+   child, it fixes up the important signals and nukes all of the fds,
+   otherwise acts like normal fork. */
+int ExecFork()
+{
+   // Fork off the process
+   pid_t Process = fork();
+   if (Process < 0)
+   {
+      cerr << "FATAL -> Failed to fork." << endl;
+      exit(100);
+   }

 
 

-   if (select(Fd+1,&Set,0,0,0) <= 0)
-      return false;
+   // Spawn the subprocess
+   if (Process == 0)
+   {
+      // Setup the signals
+      signal(SIGPIPE,SIG_DFL);
+      signal(SIGQUIT,SIG_DFL);
+      signal(SIGINT,SIG_DFL);
+      signal(SIGWINCH,SIG_DFL);
+      signal(SIGCONT,SIG_DFL);
+      signal(SIGTSTP,SIG_DFL);
+      
+      // Close all of our FDs - just in case
+      for (int K = 3; K != 40; K++)
+        fcntl(K,F_SETFD,FD_CLOEXEC);
+   }
+   
+   return Process;
+}
+                                                                       /*}}}*/
+// ExecWait - Fancy waitpid                                            /*{{{*/
+// ---------------------------------------------------------------------
+/* Waits for the given sub process. If Reap is set the no errors are 
+   generated. Otherwise a failed subprocess will generate a proper descriptive
+   message */
+bool ExecWait(int Pid,const char *Name,bool Reap)
+{
+   if (Pid <= 1)
+      return true;
+   
+   // Wait and collect the error code
+   int Status;
+   while (waitpid(Pid,&Status,0) != Pid)
+   {
+      if (errno == EINTR)
+        continue;

 
 

+      if (Reap == true)
+        return false;
+      
+      return _error->Error("Waited, for %s but it wasn't there",Name);
+   }
+
+   
+   // Check for an error code.
+   if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
+   {
+      if (Reap == true)
+        return false;
+      if (WIFSIGNALED(Status) != 0 && WTERMSIG(Status) == SIGSEGV)
+        return _error->Error("Sub-process %s recieved a segmentation fault.",Name);
+
+      if (WIFEXITED(Status) != 0)
+        return _error->Error("Sub-process %s returned an error code (%u)",Name,WEXITSTATUS(Status));
+      
+      return _error->Error("Sub-process %s exited unexpectedly",Name);
+   }      
+   

    return true;
 }
                                                                        /*}}}*/
 
    return true;
 }
                                                                        /*}}}*/
 

-// FileFd::FileFd - Open a file                                                /*{{{*/
+// FileFd::Open - Open a file                                          /*{{{*/

 // ---------------------------------------------------------------------
 /* The most commonly used open mode combinations are given with Mode */
 // ---------------------------------------------------------------------
 /* The most commonly used open mode combinations are given with Mode */

-FileFd::FileFd(string FileName,OpenMode Mode, unsigned long Perms)
+bool FileFd::Open(string FileName,OpenMode Mode, unsigned long Perms)

 {
 {

+   Close();

    Flags = AutoClose;
    switch (Mode)
    {
    Flags = AutoClose;
    switch (Mode)
    {


@@ -186,9 +345,13 @@ FileFd::FileFd(string FileName,OpenMode Mode, unsigned long Perms)
       break;
       
       case WriteEmpty:
       break;
       
       case WriteEmpty:

-      unlink(FileName.c_str());
-      iFd = open(FileName.c_str(),O_RDWR | O_CREAT | O_EXCL,Perms);
-      break;
+      {
+        struct stat Buf;
+        if (lstat(FileName.c_str(),&Buf) == 0 && S_ISLNK(Buf.st_mode))
+           unlink(FileName.c_str());
+        iFd = open(FileName.c_str(),O_RDWR | O_CREAT | O_TRUNC,Perms);
+        break;
+      }

       
       case WriteExists:
       iFd = open(FileName.c_str(),O_RDWR);
       
       case WriteExists:
       iFd = open(FileName.c_str(),O_RDWR);


@@ -200,12 +363,11 @@ FileFd::FileFd(string FileName,OpenMode Mode, unsigned long Perms)
    }  
 
    if (iFd < 0)
    }  
 
    if (iFd < 0)

-      _error->Errno("open","Could not open file %s",FileName.c_str());
-   else
-   {
-      this->FileName = FileName;
-      SetCloseExec(iFd,true);
-   }   
+      return _error->Errno("open","Could not open file %s",FileName.c_str());
+   
+   this->FileName = FileName;
+   SetCloseExec(iFd,true);
+   return true;

 }
                                                                        /*}}}*/
 // FileFd::~File - Closes the file                                     /*{{{*/
 }
                                                                        /*}}}*/
 // FileFd::~File - Closes the file                                     /*{{{*/


@@ -219,16 +381,40 @@ FileFd::~FileFd()
                                                                        /*}}}*/
 // FileFd::Read - Read a bit of the file                               /*{{{*/
 // ---------------------------------------------------------------------
                                                                        /*}}}*/
 // FileFd::Read - Read a bit of the file                               /*{{{*/
 // ---------------------------------------------------------------------

-/* */
-bool FileFd::Read(void *To,unsigned long Size)
+/* We are carefull to handle interruption by a signal while reading 
+   gracefully. */
+bool FileFd::Read(void *To,unsigned long Size,bool AllowEof)

 {
 {

-   if (read(iFd,To,Size) != (signed)Size)
+   int Res;
+   errno = 0;
+   do

    {
    {

-      Flags |= Fail;
-      return _error->Errno("read","Read error");
-   }   
+      Res = read(iFd,To,Size);
+      if (Res < 0 && errno == EINTR)
+        continue;
+      if (Res < 0)
+      {
+        Flags |= Fail;
+        return _error->Errno("read","Read error");
+      }

       
       

-   return true;
+      To = (char *)To + Res;
+      Size -= Res;
+   }
+   while (Res > 0 && Size > 0);
+   
+   if (Size == 0)
+      return true;
+   
+   // Eof handling
+   if (AllowEof == true)
+   {
+      Flags |= HitEof;
+      return true;
+   }
+   
+   Flags |= Fail;
+   return _error->Error("read, still have %u to read but none left",Size);

 }
                                                                        /*}}}*/
 // FileFd::Write - Write to the file                                   /*{{{*/
 }
                                                                        /*}}}*/
 // FileFd::Write - Write to the file                                   /*{{{*/


@@ -236,13 +422,29 @@ bool FileFd::Read(void *To,unsigned long Size)
 /* */
 bool FileFd::Write(const void *From,unsigned long Size)
 {
 /* */
 bool FileFd::Write(const void *From,unsigned long Size)
 {

-   if (write(iFd,From,Size) != (signed)Size)
+   int Res;
+   errno = 0;
+   do

    {
    {

-      Flags |= Fail;
-      return _error->Errno("write","Write error");
+      Res = write(iFd,From,Size);
+      if (Res < 0 && errno == EINTR)
+        continue;
+      if (Res < 0)
+      {
+        Flags |= Fail;
+        return _error->Errno("write","Write error");
+      }
+      
+      From = (char *)From + Res;
+      Size -= Res;

    }
    }

+   while (Res > 0 && Size > 0);

    
    

-   return true;
+   if (Size == 0)
+      return true;
+   
+   Flags |= Fail;
+   return _error->Error("write, still have %u to write but couldn't",Size);

 }
                                                                        /*}}}*/
 // FileFd::Seek - Seek in the file                                     /*{{{*/
 }
                                                                        /*}}}*/
 // FileFd::Seek - Seek in the file                                     /*{{{*/


@@ -259,6 +461,45 @@ bool FileFd::Seek(unsigned long To)
    return true;
 }
                                                                        /*}}}*/
    return true;
 }
                                                                        /*}}}*/

+// FileFd::Skip - Seek in the file                                     /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileFd::Skip(unsigned long Over)
+{
+   if (lseek(iFd,Over,SEEK_CUR) < 0)
+   {
+      Flags |= Fail;
+      return _error->Error("Unable to seek ahead %u",Over);
+   }
+   
+   return true;
+}
+                                                                       /*}}}*/
+// FileFd::Truncate - Truncate the file                                /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileFd::Truncate(unsigned long To)
+{
+   if (ftruncate(iFd,To) != 0)
+   {
+      Flags |= Fail;
+      return _error->Error("Unable to truncate to %u",To);
+   }
+   
+   return true;
+}
+                                                                       /*}}}*/
+// FileFd::Tell - Current seek position                                        /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+unsigned long FileFd::Tell()
+{
+   off_t Res = lseek(iFd,0,SEEK_CUR);
+   if (Res == (off_t)-1)
+      _error->Errno("lseek","Failed to determine the current file position");
+   return Res;
+}
+                                                                       /*}}}*/

 // FileFd::Size - Return the size of the file                          /*{{{*/
 // ---------------------------------------------------------------------
 /* */
 // FileFd::Size - Return the size of the file                          /*{{{*/
 // ---------------------------------------------------------------------
 /* */