Merge branch 'pu/heavy-hooks' into 'master'

json-based hooks for apt cli tools

See merge request apt-team/apt!10

1 files changed, 425 insertions, 0 deletions

diff --git a/apt-private/private-json-hooks.cc b/apt-private/private-json-hooks.cc
new file mode 100644
index 000000000..07c89ca23
--- /dev/null
+++ b/apt-private/private-json-hooks.cc
@@ -0,0 +1,425 @@
+/*
+ * private-json-hooks.cc - 2nd generation, JSON-RPC, hooks for APT
+ *
+ * Copyright (c) 2018 Canonical Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <apt-pkg/debsystem.h>
+#include <apt-pkg/macros.h>
+#include <apt-private/private-json-hooks.h>
+
+#include <ostream>
+#include <sstream>
+#include <stack>
+
+#include <signal.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+/**
+ * @brief Simple JSON writer
+ *
+ * This performs no error checking, or string escaping, be careful.
+ */
+class APT_HIDDEN JsonWriter
+{
+   std::ostream &os;
+   std::locale old_locale;
+
+   enum write_state
+   {
+      empty,
+      in_array_first_element,
+      in_array,
+      in_object_first_key,
+      in_object_key,
+      in_object_val
+   } state = empty;
+
+   std::stack<write_state> old_states;
+
+   void maybeComma()
+   {
+      switch (state)
+      {
+      case empty:
+	 break;
+      case in_object_val:
+	 state = in_object_key;
+	 break;
+      case in_object_key:
+	 state = in_object_val;
+	 os << ',';
+	 break;
+      case in_array:
+	 os << ',';
+	 break;
+      case in_array_first_element:
+	 state = in_array;
+	 break;
+      case in_object_first_key:
+	 state = in_object_val;
+	 break;
+      default:
+	 abort();
+      }
+   }
+
+   void pushState(write_state state)
+   {
+      old_states.push(this->state);
+      this->state = state;
+   }
+
+   void popState()
+   {
+      this->state = old_states.top();
+   }
+
+   public:
+   JsonWriter(std::ostream &os) : os(os) { old_locale = os.imbue(std::locale::classic()); }
+   ~JsonWriter() { os.imbue(old_locale); }
+   JsonWriter &beginArray()
+   {
+      maybeComma();
+      pushState(in_array_first_element);
+      os << '[';
+      return *this;
+   }
+   JsonWriter &endArray()
+   {
+      popState();
+      os << ']';
+      return *this;
+   }
+   JsonWriter &beginObject()
+   {
+      maybeComma();
+      pushState(in_object_first_key);
+      os << '{';
+      return *this;
+   }
+   JsonWriter &endObject()
+   {
+      popState();
+      os << '}';
+      return *this;
+   }
+   JsonWriter &name(std::string const &name)
+   {
+      maybeComma();
+      os << '"' << name << '"' << ':';
+      return *this;
+   }
+   JsonWriter &value(std::string const &value)
+   {
+      maybeComma();
+      os << '"' << value << '"';
+      return *this;
+   }
+   JsonWriter &value(const char *value)
+   {
+      maybeComma();
+      os << '"' << value << '"';
+      return *this;
+   }
+   JsonWriter &value(int value)
+   {
+      maybeComma();
+      os << value;
+      return *this;
+   }
+   JsonWriter &value(long value)
+   {
+      maybeComma();
+      os << value;
+      return *this;
+   }
+   JsonWriter &value(long long value)
+   {
+      maybeComma();
+      os << value;
+      return *this;
+   }
+   JsonWriter &value(unsigned long long value)
+   {
+      maybeComma();
+      os << value;
+      return *this;
+   }
+   JsonWriter &value(unsigned long value)
+   {
+      maybeComma();
+      os << value;
+      return *this;
+   }
+   JsonWriter &value(unsigned int value)
+   {
+      maybeComma();
+      os << value;
+      return *this;
+   }
+   JsonWriter &value(bool value)
+   {
+      maybeComma();
+      os << (value ? "true" : "false");
+      return *this;
+   }
+   JsonWriter &value(double value)
+   {
+      maybeComma();
+      os << value;
+      return *this;
+   }
+};
+
+/**
+ * @brief Wrtie a VerIterator to a JsonWriter
+ */
+static void verIterToJson(JsonWriter &writer, CacheFile &Cache, pkgCache::VerIterator const &Ver)
+{
+   writer.beginObject();
+   writer.name("id").value(Ver->ID);
+   writer.name("version").value(Ver.VerStr());
+   writer.name("architecture").value(Ver.Arch());
+   writer.name("pin").value(Cache->GetPolicy().GetPriority(Ver));
+   writer.endObject();
+}
+
+/**
+ * @brief Copy of debSystem::DpkgChrootDirectory()
+ * @todo Remove
+ */
+static void DpkgChrootDirectory()
+{
+   std::string const chrootDir = _config->FindDir("DPkg::Chroot-Directory");
+   if (chrootDir == "/")
+      return;
+   std::cerr << "Chrooting into " << chrootDir << std::endl;
+   if (chroot(chrootDir.c_str()) != 0)
+      _exit(100);
+   if (chdir("/") != 0)
+      _exit(100);
+}
+
+/**
+ * @brief Send a notification to the hook's stream
+ */
+static void NotifyHook(std::ostream &os, std::string const &method, const char **FileList, CacheFile &Cache, std::set<std::string> const &UnknownPackages)
+{
+   SortedPackageUniverse Universe(Cache);
+   JsonWriter jsonWriter{os};
+
+   jsonWriter.beginObject();
+
+   jsonWriter.name("jsonrpc").value("2.0");
+   jsonWriter.name("method").value(method);
+
+   /* Build params */
+   jsonWriter.name("params").beginObject();
+   jsonWriter.name("command").value(FileList[0]);
+   jsonWriter.name("search-terms").beginArray();
+   for (int i = 1; FileList[i] != NULL; i++)
+      jsonWriter.value(FileList[i]);
+   jsonWriter.endArray();
+   jsonWriter.name("unknown-packages").beginArray();
+   for (auto const &PkgName : UnknownPackages)
+      jsonWriter.value(PkgName);
+   jsonWriter.endArray();
+
+   jsonWriter.name("packages").beginArray();
+   for (auto const &Pkg : Universe)
+   {
+      switch (Cache[Pkg].Mode)
+      {
+      case pkgDepCache::ModeInstall:
+      case pkgDepCache::ModeDelete:
+	 break;
+      default:
+	 continue;
+      }
+
+      jsonWriter.beginObject();
+
+      jsonWriter.name("id").value(Pkg->ID);
+      jsonWriter.name("name").value(Pkg.Name());
+      jsonWriter.name("architecture").value(Pkg.Arch());
+
+      switch (Cache[Pkg].Mode)
+      {
+      case pkgDepCache::ModeInstall:
+	 jsonWriter.name("mode").value("install");
+	 break;
+      case pkgDepCache::ModeDelete:
+	 jsonWriter.name("mode").value(Cache[Pkg].Purge() ? "purge" : "deinstall");
+	 break;
+      default:
+	 continue;
+      }
+      jsonWriter.name("automatic").value(bool(Cache[Pkg].Flags & pkgCache::Flag::Auto));
+
+      jsonWriter.name("versions").beginObject();
+
+      if (Cache[Pkg].CandidateVer != nullptr)
+	 verIterToJson(jsonWriter.name("candidate"), Cache, Cache[Pkg].CandidateVerIter(Cache));
+      if (Cache[Pkg].InstallVer != nullptr)
+	 verIterToJson(jsonWriter.name("install"), Cache, Cache[Pkg].InstVerIter(Cache));
+      if (Pkg->CurrentVer != 0)
+	 verIterToJson(jsonWriter.name("current"), Cache, Pkg.CurrentVer());
+
+      jsonWriter.endObject();
+
+      jsonWriter.endObject();
+   }
+
+   jsonWriter.endArray();  // packages
+   jsonWriter.endObject(); // params
+   jsonWriter.endObject(); // main
+}
+
+/// @brief Build the hello handshake message for 0.1 protocol
+static std::string BuildHelloMessage()
+{
+   std::stringstream Hello;
+   JsonWriter(Hello).beginObject().name("jsonrpc").value("2.0").name("method").value("org.debian.apt.hooks.hello").name("id").value(0).name("params").beginObject().name("versions").beginArray().value("0.1").endArray().endObject().endObject();
+
+   return Hello.str();
+}
+
+/// @brief Build the bye notification for 0.1 protocol
+static std::string BuildByeMessage()
+{
+   std::stringstream Bye;
+   JsonWriter(Bye).beginObject().name("jsonrpc").value("2.0").name("method").value("org.debian.apt.hooks.bye").name("params").beginObject().endObject().endObject();
+
+   return Bye.str();
+}
+
+/// @brief Run the Json hook processes in the given option.
+bool RunJsonHook(std::string const &option, std::string const &method, const char **FileList, CacheFile &Cache, std::set<std::string> const &UnknownPackages)
+{
+   std::stringstream ss;
+   NotifyHook(ss, method, FileList, Cache, UnknownPackages);
+   std::string TheData = ss.str();
+   std::string HelloData = BuildHelloMessage();
+   std::string ByeData = BuildByeMessage();
+
+   bool result = true;
+
+   Configuration::Item const *Opts = _config->Tree(option.c_str());
+   if (Opts == 0 || Opts->Child == 0)
+      return true;
+   Opts = Opts->Child;
+
+   sighandler_t old_sigpipe = signal(SIGPIPE, SIG_IGN);
+   sighandler_t old_sigint = signal(SIGINT, SIG_IGN);
+   sighandler_t old_sigquit = signal(SIGQUIT, SIG_IGN);
+
+   unsigned int Count = 1;
+   for (; Opts != 0; Opts = Opts->Next, Count++)
+   {
+      if (Opts->Value.empty() == true)
+	 continue;
+
+      if (_config->FindB("Debug::RunScripts", false) == true)
+	 std::clog << "Running external script with list of all .deb file: '"
+		   << Opts->Value << "'" << std::endl;
+
+      // Create the pipes
+      std::set<int> KeepFDs;
+      MergeKeepFdsFromConfiguration(KeepFDs);
+      int Pipes[2];
+      if (socketpair(AF_UNIX, SOCK_STREAM, 0, Pipes) != 0)
+      {
+	 result = _error->Errno("pipe", "Failed to create IPC pipe to subprocess");
+	 break;
+      }
+
+      int InfoFD = 3;
+
+      if (InfoFD != Pipes[0])
+	 SetCloseExec(Pipes[0], true);
+      else
+	 KeepFDs.insert(Pipes[0]);
+
+      SetCloseExec(Pipes[1], true);
+
+      // Purified Fork for running the script
+      pid_t Process = ExecFork(KeepFDs);
+      if (Process == 0)
+      {
+	 // Setup the FDs
+	 dup2(Pipes[0], InfoFD);
+	 SetCloseExec(STDOUT_FILENO, false);
+	 SetCloseExec(STDIN_FILENO, false);
+	 SetCloseExec(STDERR_FILENO, false);
+
+	 string hookfd;
+	 strprintf(hookfd, "%d", InfoFD);
+	 setenv("APT_HOOK_SOCKET", hookfd.c_str(), 1);
+
+	 DpkgChrootDirectory();
+	 const char *Args[4];
+	 Args[0] = "/bin/sh";
+	 Args[1] = "-c";
+	 Args[2] = Opts->Value.c_str();
+	 Args[3] = 0;
+	 execv(Args[0], (char **)Args);
+	 _exit(100);
+      }
+      close(Pipes[0]);
+      FILE *F = fdopen(Pipes[1], "w+");
+      if (F == 0)
+      {
+	 result = _error->Errno("fdopen", "Failed to open new FD");
+	 break;
+      }
+
+      fwrite(HelloData.data(), HelloData.size(), 1, F);
+      fwrite("\n\n", 2, 1, F);
+      fflush(F);
+
+      char *line = nullptr;
+      size_t linesize = 0;
+      ssize_t size = getline(&line, &linesize, F);
+
+      if (size < 0)
+      {
+	 _error->Error("Could not read response to hello message from hook %s: %s", Opts->Value.c_str(), strerror(errno));
+      }
+      else if (strstr(line, "error") != nullptr)
+      {
+	 _error->Error("Hook %s reported an error during hello: %s", Opts->Value.c_str(), line);
+      }
+
+      size = getline(&line, &linesize, F);
+      if (size < 0)
+      {
+	 _error->Error("Could not read message separator line after handshake from %s: %s", Opts->Value.c_str(), strerror(errno));
+      }
+      else if (size == 0 || line[0] != '\n')
+      {
+	 _error->Error("Expected empty line after handshake from %s, received %s", Opts->Value.c_str(), line);
+      }
+
+      fwrite(TheData.data(), TheData.size(), 1, F);
+      fwrite("\n\n", 2, 1, F);
+
+      fwrite(ByeData.data(), ByeData.size(), 1, F);
+      fwrite("\n\n", 2, 1, F);
+      fclose(F);
+      // Clean up the sub process
+      if (ExecWait(Process, Opts->Value.c_str()) == false)
+      {
+	 result = _error->Error("Failure running hook %s", Opts->Value.c_str());
+	 break;
+      }
+   }
+   signal(SIGINT, old_sigint);
+   signal(SIGPIPE, old_sigpipe);
+   signal(SIGQUIT, old_sigquit);
+
+   return result;
+}