Merge branch 'feature/methods'

5 files changed, 124 insertions, 29 deletions

diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index ad8cb7f24..f13d2f6ae 100644
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -685,10 +685,15 @@ class APT_HIDDEN CleanupItem : public pkgAcqTransactionItem		/*{{{*/
 									/*}}}*/
 
 // Acquire::Item::Item - Constructor					/*{{{*/
+class pkgAcquire::Item::Private
+{
+public:
+   std::vector<std::string> PastRedirections;
+};
 APT_IGNORE_DEPRECATED_PUSH
 pkgAcquire::Item::Item(pkgAcquire * const owner) :
    FileSize(0), PartialSize(0), Mode(0), ID(0), Complete(false), Local(false),
-    QueueCounter(0), ExpectedAdditionalItems(0), Owner(owner), d(NULL)
+    QueueCounter(0), ExpectedAdditionalItems(0), Owner(owner), d(new Private())
 {
    Owner->Add(this);
    Status = StatIdle;
@@ -699,6 +704,7 @@ APT_IGNORE_DEPRECATED_POP
 pkgAcquire::Item::~Item()
 {
    Owner->Remove(this);
+   delete d;
 }
 									/*}}}*/
 std::string pkgAcquire::Item::Custom600Headers() const			/*{{{*/
@@ -766,32 +772,40 @@ void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig con
    }
 
    string const FailReason = LookupTag(Message, "FailReason");
-   enum { MAXIMUM_SIZE_EXCEEDED, HASHSUM_MISMATCH, WEAK_HASHSUMS, OTHER } failreason = OTHER;
+   enum { MAXIMUM_SIZE_EXCEEDED, HASHSUM_MISMATCH, WEAK_HASHSUMS, REDIRECTION_LOOP, OTHER } failreason = OTHER;
    if ( FailReason == "MaximumSizeExceeded")
       failreason = MAXIMUM_SIZE_EXCEEDED;
    else if ( FailReason == "WeakHashSums")
       failreason = WEAK_HASHSUMS;
+   else if (FailReason == "RedirectionLoop")
+      failreason = REDIRECTION_LOOP;
    else if (Status == StatAuthError)
       failreason = HASHSUM_MISMATCH;
 
    if(ErrorText.empty())
    {
+      std::ostringstream out;
+      switch (failreason)
+      {
+	 case HASHSUM_MISMATCH:
+	    out << _("Hash Sum mismatch") << std::endl;
+	    break;
+	 case WEAK_HASHSUMS:
+	    out << _("Insufficient information available to perform this download securely") << std::endl;
+	    break;
+	 case REDIRECTION_LOOP:
+	    out << "Redirection loop encountered" << std::endl;
+	    break;
+	 case MAXIMUM_SIZE_EXCEEDED:
+	    out << LookupTag(Message, "Message") << std::endl;
+	    break;
+	 case OTHER:
+	    out << LookupTag(Message, "Message");
+	    break;
+      }
+
       if (Status == StatAuthError)
       {
-	 std::ostringstream out;
-	 switch (failreason)
-	 {
-	    case HASHSUM_MISMATCH:
-	       out << _("Hash Sum mismatch") << std::endl;
-	       break;
-	    case WEAK_HASHSUMS:
-	       out << _("Insufficient information available to perform this download securely") << std::endl;
-	       break;
-	    case MAXIMUM_SIZE_EXCEEDED:
-	    case OTHER:
-	       out << LookupTag(Message, "Message") << std::endl;
-	       break;
-	 }
 	 auto const ExpectedHashes = GetExpectedHashes();
 	 if (ExpectedHashes.empty() == false)
 	 {
@@ -822,10 +836,8 @@ void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig con
 	    }
 	    out << "Last modification reported: " << LookupTag(Message, "Last-Modified", "<none>") << std::endl;
 	 }
-	 ErrorText = out.str();
       }
-      else
-	 ErrorText = LookupTag(Message,"Message");
+      ErrorText = out.str();
    }
 
    switch (failreason)
@@ -833,6 +845,7 @@ void pkgAcquire::Item::Failed(string const &Message,pkgAcquire::MethodConfig con
       case MAXIMUM_SIZE_EXCEEDED: RenameOnError(MaximumSizeExceeded); break;
       case HASHSUM_MISMATCH: RenameOnError(HashSumMismatch); break;
       case WEAK_HASHSUMS: break;
+      case REDIRECTION_LOOP: break;
       case OTHER: break;
    }
 
@@ -976,6 +989,24 @@ std::string pkgAcquire::Item::HashSum() const				/*{{{*/
    return hs != NULL ? hs->toStr() : "";
 }
 									/*}}}*/
+bool pkgAcquire::Item::IsRedirectionLoop(std::string const &NewURI)	/*{{{*/
+{
+   if (d->PastRedirections.empty())
+   {
+      d->PastRedirections.push_back(NewURI);
+      return false;
+   }
+   auto const LastURI = std::prev(d->PastRedirections.end());
+   // redirections to the same file are a way of restarting/resheduling,
+   // individual methods will have to make sure that they aren't looping this way
+   if (*LastURI == NewURI)
+      return false;
+   if (std::find(d->PastRedirections.begin(), LastURI, NewURI) != LastURI)
+      return true;
+   d->PastRedirections.push_back(NewURI);
+   return false;
+}
+									/*}}}*/
 
 pkgAcqTransactionItem::pkgAcqTransactionItem(pkgAcquire * const Owner,	/*{{{*/
       pkgAcqMetaClearSig * const transactionManager, IndexTarget const &target) :
diff --git a/apt-pkg/acquire-item.h b/apt-pkg/acquire-item.h
index ac4994738..e6e5ea12b 100644
--- a/apt-pkg/acquire-item.h
+++ b/apt-pkg/acquire-item.h
@@ -304,6 +304,8 @@ class pkgAcquire::Item : public WeakPointable				/*{{{*/
     */
    virtual ~Item();
 
+   bool APT_HIDDEN IsRedirectionLoop(std::string const &NewURI);
+
    protected:
    /** \brief The acquire object with which this item is associated. */
    pkgAcquire * const Owner;
@@ -357,7 +359,8 @@ class pkgAcquire::Item : public WeakPointable				/*{{{*/
    virtual std::string GetFinalFilename() const;
 
    private:
-   void * const d;
+   class Private;
+   Private * const d;
 
    friend class pkgAcqMetaBase;
    friend class pkgAcqMetaClearSig;
diff --git a/apt-pkg/acquire-worker.cc b/apt-pkg/acquire-worker.cc
index 9ed7b5b28..7a4f8177f 100644
--- a/apt-pkg/acquire-worker.cc
+++ b/apt-pkg/acquire-worker.cc
@@ -93,17 +93,38 @@ pkgAcquire::Worker::~Worker()
 bool pkgAcquire::Worker::Start()
 {
    // Get the method path
-   string Method = _config->FindDir("Dir::Bin::Methods") + Access;
+   constexpr char const * const methodsDir = "Dir::Bin::Methods";
+   std::string const confItem = std::string(methodsDir) + "::" + Access;
+   std::string Method;
+   if (_config->Exists(confItem))
+	 Method = _config->FindFile(confItem.c_str());
+   else
+	 Method = _config->FindDir(methodsDir) + Access;
    if (FileExists(Method) == false)
    {
+      if (flNotDir(Method) == "false")
+      {
+	 _error->Error(_("The method '%s' is explicitly disabled via configuration."), Access.c_str());
+	 if (Access == "http" || Access == "https")
+	    _error->Notice(_("If you meant to use Tor remember to use %s instead of %s."), ("tor+" + Access).c_str(), Access.c_str());
+	 return false;
+      }
       _error->Error(_("The method driver %s could not be found."),Method.c_str());
-      if (Access == "https")
-	 _error->Notice(_("Is the package %s installed?"), "apt-transport-https");
+      std::string const A(Access.cbegin(), std::find(Access.cbegin(), Access.cend(), '+'));
+      std::string pkg;
+      strprintf(pkg, "apt-transport-%s", A.c_str());
+      _error->Notice(_("Is the package %s installed?"), pkg.c_str());
       return false;
    }
+   std::string const Calling = _config->FindDir(methodsDir) + Access;
 
    if (Debug == true)
-      clog << "Starting method '" << Method << '\'' << endl;
+   {
+      std::clog << "Starting method '" << Calling << "'";
+      if (Calling != Method)
+	 std::clog << " ( via " << Method << " )";
+      std::clog << endl;
+   }
 
    // Create the pipes
    int Pipes[4] = {-1,-1,-1,-1};
@@ -128,11 +149,9 @@ bool pkgAcquire::Worker::Start()
       SetCloseExec(STDIN_FILENO,false);
       SetCloseExec(STDERR_FILENO,false);
 
-      const char *Args[2];
-      Args[0] = Method.c_str();
-      Args[1] = 0;
-      execv(Args[0],(char **)Args);
-      cerr << "Failed to exec method " << Args[0] << endl;
+      const char * const Args[] = { Calling.c_str(), nullptr };
+      execv(Method.c_str() ,const_cast<char **>(Args));
+      std::cerr << "Failed to exec method " << Calling << " ( via " << Method << ")" << endl;
       _exit(100);
    }
 
@@ -267,6 +286,16 @@ bool pkgAcquire::Worker::RunMessages()
 	    for (auto const &Owner: ItmOwners)
 	    {
 	       pkgAcquire::ItemDesc &desc = Owner->GetItemDesc();
+	       if (Owner->IsRedirectionLoop(NewURI))
+	       {
+		  std::string msg = Message;
+		  msg.append("\nFailReason: RedirectionLoop");
+		  Owner->Failed(msg, Config);
+		  if (Log != nullptr)
+		     Log->Fail(Owner->GetItemDesc());
+		  continue;
+	       }
+
 	       if (Log != nullptr)
 		  Log->Done(desc);
 
diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 342f9830d..a9d51a6bf 100644
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -2444,6 +2444,37 @@ bool FileFd::Read(void *To,unsigned long long Size,unsigned long long *Actual)
 
    return FileFdError(_("read, still have %llu to read but none left"), Size);
 }
+bool FileFd::Read(int const Fd, void *To, unsigned long long Size, unsigned long long * const Actual)
+{
+   ssize_t Res = 1;
+   errno = 0;
+   if (Actual != nullptr)
+      *Actual = 0;
+   *static_cast<char *>(To) = '\0';
+   while (Res > 0 && Size > 0)
+   {
+      Res = read(Fd, To, Size);
+      if (Res < 0)
+      {
+	 if (errno == EINTR)
+	 {
+	    Res = 1;
+	    errno = 0;
+	    continue;
+	 }
+	 return _error->Errno("read", _("Read error"));
+      }
+      To = static_cast<char *>(To) + Res;
+      Size -= Res;
+      if (Actual != 0)
+	 *Actual += Res;
+   }
+   if (Size == 0)
+      return true;
+   if (Actual != nullptr)
+      return true;
+   return _error->Error(_("read, still have %llu to read but none left"), Size);
+}
 									/*}}}*/
 // FileFd::ReadLine - Read a complete line from the file		/*{{{*/
 // ---------------------------------------------------------------------
diff --git a/apt-pkg/contrib/fileutl.h b/apt-pkg/contrib/fileutl.h
index c13613171..4a1676dc2 100644
--- a/apt-pkg/contrib/fileutl.h
+++ b/apt-pkg/contrib/fileutl.h
@@ -86,6 +86,7 @@ class FileFd
       return Read(To,Size);
    }   
    bool Read(void *To,unsigned long long Size,unsigned long long *Actual = 0);
+   bool static Read(int const Fd, void *To, unsigned long long Size, unsigned long long * const Actual = 0);
    char* ReadLine(char *To, unsigned long long const Size);
    bool Flush();
    bool Write(const void *From,unsigned long long Size);