Added some control over how dpkg is invoked

Author: jgg
Date: 1999-01-31 08:49:39 GMT
Added some control over how dpkg is invoked

apt-pkg/deb/dpkgpm.cc

@@ -1,6 +1,6 @@
 // -*- mode: cpp; mode: fold -*-
 // Description								/*{{{*/
-// $Id: dpkgpm.cc,v 1.5 1998/12/14 06:54:44 jgg Exp $
+// $Id: dpkgpm.cc,v 1.6 1999/01/31 08:49:39 jgg Exp $
 /* ######################################################################
 
    DPKG Package Manager - Provide an interface to dpkg
@@ -71,6 +71,81 @@ bool pkgDPkgPM::Remove(PkgIterator Pkg)
       return false;
    
    List.push_back(Item(Item::Remove,Pkg));
+   return true;
+}
+									/*}}}*/
+// DPkgPM::RunScripts - Run a set of scripts				/*{{{*/
+// ---------------------------------------------------------------------
+/* This looks for a list of script sto run from the configuration file,
+   each one is run with system from a forked child. */
+bool pkgDPkgPM::RunScripts(const char *Cnf)
+{
+   Configuration::Item const *Opts = _config->Tree(Cnf);
+   if (Opts == 0 || Opts->Child == 0)
+      return true;
+   Opts = Opts->Child;
+
+   // Fork for running the system calls
+   pid_t Child = fork();
+   if (Child < 0)
+      return _error->Errno("fork","Could't fork");
+   
+   // This is the child
+   if (Child == 0)
+   {
+      signal(SIGPIPE,SIG_DFL);
+      signal(SIGQUIT,SIG_DFL);
+      signal(SIGINT,SIG_DFL);
+      signal(SIGWINCH,SIG_DFL);
+      signal(SIGCONT,SIG_DFL);
+      signal(SIGTSTP,SIG_DFL);
+      
+      if (chdir("/tmp/") != 0)
+	 _exit(100);
+	 
+      // Close all of our FDs - just in case
+      for (int K = 3; K != 40; K++)
+	 fcntl(K,F_SETFD,FD_CLOEXEC);
+
+      unsigned int Count = 1;
+      for (; Opts != 0; Opts = Opts->Next, Count++)
+      {
+	 if (Opts->Value.empty() == true)
+	    continue;
+	 
+	 if (system(Opts->Value.c_str()) != 0)
+	    _exit(100+Count);
+      }
+      _exit(0);
+   }      
+
+   // Wait for the child
+   int Status = 0;
+   while (waitpid(Child,&Status,0) != Child)
+   {
+      if (errno == EINTR)
+	 continue;
+      return _error->Errno("waitpid","Couldn't wait for subprocess");
+   }
+
+   // Restore sig int/quit
+   signal(SIGQUIT,SIG_DFL);
+   signal(SIGINT,SIG_DFL);   
+       
+   // Check for an error code.
+   if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
+   {
+      unsigned int Count = WEXITSTATUS(Status);
+      if (Count > 100)
+      {
+	 Count -= 100;
+	 for (; Opts != 0 && Count != 1; Opts = Opts->Next, Count--);
+	 _error->Error("Probablem executing scripts %s '%s'",Cnf,Opts->Value.c_str());
+      }
+      
+      return _error->Error("Sub-process returned an error code");
+   }
+   
    return true;
 }
 									/*}}}*/
@@ -79,6 +154,9 @@ bool pkgDPkgPM::Remove(PkgIterator Pkg)
 /* This globs the operations and calls dpkg */
 bool pkgDPkgPM::Go()
 {
+   if (RunScripts("DPkg::Pre-Invoke") == false)
+      return false;
+   
    for (vector<Item>::iterator I = List.begin(); I != List.end();)
    {
       vector<Item>::iterator J = I;
@@ -94,6 +172,20 @@ bool pkgDPkgPM::Go()
       Args[n++] = _config->Find("Dir::Bin::dpkg","dpkg").c_str();
       Size += strlen(Args[n-1]);
       
+      // Stick in any custom dpkg options
+      Configuration::Item const *Opts = _config->Tree("DPkg::Options");
+      if (Opts != 0)
+      {
+	 Opts = Opts->Child;
+	 for (; Opts != 0; Opts = Opts->Next)
+	 {
+	    if (Opts->Value.empty() == true)
+	       continue;
+	    Args[n++] = Opts->Value.c_str();
+	    Size += Opts->Value.length();
+	 }	 
+      }
+      
       switch (I->Op)
       {
 	 case Item::Remove:
@@ -154,12 +246,12 @@ bool pkgDPkgPM::Go()
 	 it doesn't die but we do! So we must also ignore it */
       signal(SIGQUIT,SIG_IGN);
       signal(SIGINT,SIG_IGN);
-	     
+		     
       // Fork dpkg
       pid_t Child = fork();
       if (Child < 0)
 	 return _error->Errno("fork","Could't fork");
-      
+            
       // This is the child
       if (Child == 0)
       {
@@ -169,7 +261,7 @@ bool pkgDPkgPM::Go()
 	 signal(SIGWINCH,SIG_DFL);
 	 signal(SIGCONT,SIG_DFL);
 	 signal(SIGTSTP,SIG_DFL);
-
+	 
 	 if (chdir(_config->FindDir("Dir::Cache::Archives").c_str()) != 0)
 	    _exit(100);
 	 
@@ -204,17 +296,24 @@ bool pkgDPkgPM::Go()
       {
 	 if (errno == EINTR)
 	    continue;
+	 RunScripts("DPkg::Post-Invoke");
 	 return _error->Errno("waitpid","Couldn't wait for subprocess");
       }
-      
-      // Check for an error code.
-      if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
-	 return _error->Error("Sub-process returned an error code");
 
       // Restore sig int/quit
       signal(SIGQUIT,SIG_DFL);
       signal(SIGINT,SIG_DFL);
+       
+      // Check for an error code.
+      if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
+      {
+	 RunScripts("DPkg::Post-Invoke");
+	 return _error->Error("Sub-process returned an error code");
+      }      
    }
+
+   if (RunScripts("DPkg::Post-Invoke") == false)
+      return false;
    return true;
 }
 									/*}}}*/

apt-pkg/deb/dpkgpm.h

@@ -1,6 +1,6 @@
 // -*- mode: cpp; mode: fold -*-
 // Description								/*{{{*/
-// $Id: dpkgpm.h,v 1.2 1998/11/23 07:03:12 jgg Exp $
+// $Id: dpkgpm.h,v 1.3 1999/01/31 08:49:39 jgg Exp $
 /* ######################################################################
 
    DPKG Package Manager - Provide an interface to dpkg
@@ -32,7 +32,10 @@ class pkgDPkgPM : public pkgPackageManager
       
    };
    vector<Item> List;
-      
+
+   // Helpers
+   bool RunScripts(const char *Cnf);
+   
    // The Actuall installation implementation
    virtual bool Install(PkgIterator Pkg,string File);
    virtual bool Configure(PkgIterator Pkg);

doc/apt.conf.5.yo

@@ -155,6 +155,21 @@ If true the [U]pdate operation in dselect will always prompt to continue.
 The default is to prompt only on error.
 enddit()
 
+manpagesection(How APT calls DPkg)
+Several configuration directives control how APT invokes dpkg. These are in 
+the bf(DPkg) section.
+
+startdit()
+dit(bf(Options))
+This is a list of options to pass to dpkg. The options must be specified
+using the list notation and each list item is passed as a single arugment
+to dpkg.
+
+dit(bf(Pre-Invoke))
+This is a list of shell commands to run before invoking dpkg. 
+
+enddit()
+
 manpagesection(Debug Options)
 Most of the options in the bf(debug) section are not interesting to the
 normal user, however bf(Debug::pkgProblemResolver) shows interesting

doc/examples/apt.conf

@@ -1,9 +1,9 @@
-// $Id: apt.conf,v 1.22 1999/01/31 06:24:46 jgg Exp $
+// $Id: apt.conf,v 1.23 1999/01/31 08:49:39 jgg Exp $
 /* This file is an index of all APT configuration directives. It should
    NOT actually be used as a real config file, though it is a completely
    valid file.
    
-   In some instances involing filenames it is possible to set the default
+   In some instances involving filenames it is possible to set the default
    directory when the path is evaluated. This means you can use relative
    paths within the sub scope.
    
@@ -116,6 +116,12 @@ DSelect {
    PromptAfterUpdate "no";
 }
 
+DPkg {
+   Options {"--force-downgrade";}
+   Pre-Invoke {"mount -o remount,rw /usr";};
+   Post-Invoke {"mount -o remount,ro /usr";};
+}
+
 /* Options you can set to see some debugging text They corrispond to names
    of classes in the source code */
 Debug {