Refactoring louloulibs and cmake

Use OBJECT libraries
Remove the louloulibs directory
Write FOUND variables in the cache

18 files changed, 2268 insertions, 1 deletions

diff --git a/src/xmpp/adhoc_command.cpp b/src/xmpp/adhoc_command.cpp
new file mode 100644
index 0000000..825cc92
--- /dev/null
+++ b/src/xmpp/adhoc_command.cpp
@@ -0,0 +1,80 @@
+#include <xmpp/adhoc_command.hpp>
+#include <xmpp/xmpp_component.hpp>
+#include <utils/reload.hpp>
+
+using namespace std::string_literals;
+
+AdhocCommand::AdhocCommand(std::vector<AdhocStep>&& callbacks, const std::string& name, const bool admin_only):
+  name(name),
+  callbacks(std::move(callbacks)),
+  admin_only(admin_only)
+{
+}
+
+bool AdhocCommand::is_admin_only() const
+{
+  return this->admin_only;
+}
+
+void PingStep1(XmppComponent&, AdhocSession&, XmlNode& command_node)
+{
+  XmlSubNode note(command_node, "note");
+  note["type"] = "info";
+  note.set_inner("Pong");
+}
+
+void HelloStep1(XmppComponent&, AdhocSession&, XmlNode& command_node)
+{
+  XmlSubNode x(command_node, "jabber:x:data:x");
+  x["type"] = "form";
+  XmlSubNode title(x, "title");
+  title.set_inner("Configure your name.");
+  XmlSubNode instructions(x, "instructions");
+  instructions.set_inner("Please provide your name.");
+  XmlSubNode name_field(x, "field");
+  name_field["var"] = "name";
+  name_field["type"] = "text-single";
+  name_field["label"] = "Your name";
+  XmlSubNode required(name_field, "required");
+}
+
+void HelloStep2(XmppComponent&, AdhocSession& session, XmlNode& command_node)
+{
+  // Find out if the name was provided in the form.
+  if (const XmlNode* x = command_node.get_child("x", "jabber:x:data"))
+    {
+      const XmlNode* name_field = nullptr;
+      for (const XmlNode* field: x->get_children("field", "jabber:x:data"))
+        if (field->get_tag("var") == "name")
+          {
+            name_field = field;
+            break;
+          }
+      if (name_field)
+        {
+          if (const XmlNode* value = name_field->get_child("value", "jabber:x:data"))
+            {
+              const std::string value_str = value->get_inner();
+              command_node.delete_all_children();
+              XmlSubNode note(command_node, "note");
+              note["type"] = "info";
+              note.set_inner("Hello "s + value_str + "!"s);
+              return;
+            }
+        }
+    }
+  command_node.delete_all_children();
+  XmlSubNode error(command_node, ADHOC_NS":error");
+  error["type"] = "modify";
+  XmlSubNode condition(error, STANZA_NS":bad-request");
+  session.terminate();
+}
+
+void Reload(XmppComponent&, AdhocSession&, XmlNode& command_node)
+{
+  ::reload_process();
+  command_node.delete_all_children();
+  XmlSubNode note(command_node, "note");
+  note["type"] = "info";
+  note.set_inner("Configuration reloaded.");
+}
diff --git a/src/xmpp/adhoc_command.hpp b/src/xmpp/adhoc_command.hpp
new file mode 100644
index 0000000..7c4de47
--- /dev/null
+++ b/src/xmpp/adhoc_command.hpp
@@ -0,0 +1,44 @@
+#pragma once
+
+/**
+ * Describe an ad-hoc command.
+ *
+ * Can only have zero or one step for now. When execution is requested, it
+ * can return a result immediately, or provide a form to be filled, and
+ * provide a result once the filled form is received.
+ */
+
+#include <xmpp/adhoc_session.hpp>
+
+#include <functional>
+#include <string>
+
+class AdhocCommand
+{
+  friend class AdhocSession;
+public:
+  AdhocCommand(std::vector<AdhocStep>&& callback, const std::string& name, const bool admin_only);
+  ~AdhocCommand() = default;
+  AdhocCommand(const AdhocCommand&) = default;
+  AdhocCommand(AdhocCommand&&) = default;
+  AdhocCommand& operator=(AdhocCommand&&) = delete;
+  AdhocCommand& operator=(const AdhocCommand&) = delete;
+
+  const std::string name;
+
+  bool is_admin_only() const;
+
+private:
+  /**
+   * A command may have one or more steps. Each step is a different
+   * callback, inserting things into a <command/> XmlNode and calling
+   * methods of an AdhocSession.
+   */
+  std::vector<AdhocStep> callbacks;
+  const bool admin_only;
+};
+
+void PingStep1(XmppComponent&, AdhocSession& session, XmlNode& command_node);
+void HelloStep1(XmppComponent&, AdhocSession& session, XmlNode& command_node);
+void HelloStep2(XmppComponent&, AdhocSession& session, XmlNode& command_node);
+void Reload(XmppComponent&, AdhocSession& session, XmlNode& command_node);
diff --git a/src/xmpp/adhoc_commands_handler.cpp b/src/xmpp/adhoc_commands_handler.cpp
new file mode 100644
index 0000000..040d0ff
--- /dev/null
+++ b/src/xmpp/adhoc_commands_handler.cpp
@@ -0,0 +1,111 @@
+#include <xmpp/adhoc_commands_handler.hpp>
+#include <xmpp/xmpp_component.hpp>
+
+#include <utils/timed_events.hpp>
+#include <logger/logger.hpp>
+#include <config/config.hpp>
+#include <xmpp/jid.hpp>
+
+#include <iostream>
+
+using namespace std::string_literals;
+
+const std::map<const std::string, const AdhocCommand>& AdhocCommandsHandler::get_commands() const
+{
+  return this->commands;
+}
+
+void AdhocCommandsHandler::add_command(std::string name, AdhocCommand command)
+{
+  const auto found = this->commands.find(name);
+  if (found != this->commands.end())
+    throw std::runtime_error("Trying to add an ad-hoc command that already exist: "s + name);
+  this->commands.emplace(std::make_pair(std::move(name), std::move(command)));
+}
+
+XmlNode AdhocCommandsHandler::handle_request(const std::string& executor_jid, const std::string& to, XmlNode command_node)
+{
+  std::string action = command_node.get_tag("action");
+  if (action.empty())
+    action = "execute";
+  command_node.del_tag("action");
+
+  Jid jid(executor_jid);
+
+  const std::string node = command_node.get_tag("node");
+  auto command_it = this->commands.find(node);
+  if (command_it == this->commands.end())
+    {
+      XmlSubNode error(command_node, ADHOC_NS":error");
+      error["type"] = "cancel";
+      XmlSubNode condition(error, STANZA_NS":item-not-found");
+    }
+  else if (command_it->second.is_admin_only() &&
+           Config::get("admin", "") != jid.local + "@" + jid.domain)
+    {
+      XmlSubNode error(command_node, ADHOC_NS":error");
+      error["type"] = "cancel";
+      XmlSubNode condition(error, STANZA_NS":forbidden");
+    }
+  else
+    {
+      std::string sessionid = command_node.get_tag("sessionid");
+      if (sessionid.empty())
+        {                       // create a new session, with a new id
+          sessionid = XmppComponent::next_id();
+          command_node["sessionid"] = sessionid;
+          this->sessions.emplace(std::piecewise_construct,
+                                 std::forward_as_tuple(sessionid, executor_jid),
+                                 std::forward_as_tuple(command_it->second, executor_jid, to));
+          TimedEventsManager::instance().add_event(TimedEvent(std::chrono::steady_clock::now() + 3600s,
+                                                              std::bind(&AdhocCommandsHandler::remove_session, this, sessionid, executor_jid),
+                                                              "adhocsession"s + sessionid + executor_jid));
+        }
+      auto session_it = this->sessions.find(std::make_pair(sessionid, executor_jid));
+      if ((session_it != this->sessions.end()) &&
+          (action == "execute" || action == "next" || action == "complete"))
+        {
+          // execute the step
+          AdhocSession& session = session_it->second;
+          const AdhocStep& step = session.get_next_step();
+          step(this->xmpp_component, session, command_node);
+          if (session.remaining_steps() == 0 ||
+              session.is_terminated())
+            {
+              this->sessions.erase(session_it);
+              command_node["status"] = "completed";
+              TimedEventsManager::instance().cancel("adhocsession"s + sessionid + executor_jid);
+            }
+          else
+            {
+              command_node["status"] = "executing";
+              XmlSubNode actions(command_node, "actions");
+              XmlSubNode next(actions, "next");
+            }
+        }
+      else if (action == "cancel")
+        {
+          this->sessions.erase(session_it);
+          command_node["status"] = "canceled";
+          TimedEventsManager::instance().cancel("adhocsession"s + sessionid + executor_jid);
+        }
+      else                      // unsupported action
+        {
+          XmlSubNode error(command_node, ADHOC_NS":error");
+          error["type"] = "modify";
+          XmlSubNode condition(error, STANZA_NS":bad-request");
+        }
+    }
+  return command_node;
+}
+
+void AdhocCommandsHandler::remove_session(const std::string& session_id, const std::string& initiator_jid)
+{
+  auto session_it = this->sessions.find(std::make_pair(session_id, initiator_jid));
+  if (session_it != this->sessions.end())
+    {
+      this->sessions.erase(session_it);
+      return ;
+    }
+  log_error("Tried to remove ad-hoc session for [", session_id, ", ", initiator_jid, "] but none found");
+}
diff --git a/src/xmpp/adhoc_commands_handler.hpp b/src/xmpp/adhoc_commands_handler.hpp
new file mode 100644
index 0000000..e37d913
--- /dev/null
+++ b/src/xmpp/adhoc_commands_handler.hpp
@@ -0,0 +1,71 @@
+#pragma once
+
+/**
+ * Manage a list of available AdhocCommands and the list of ongoing
+ * AdhocCommandSessions.
+ */
+
+#include <xmpp/adhoc_command.hpp>
+#include <xmpp/xmpp_stanza.hpp>
+
+#include <utility>
+#include <string>
+#include <map>
+
+class AdhocCommandsHandler
+{
+public:
+  explicit AdhocCommandsHandler(XmppComponent& xmpp_component):
+    xmpp_component(xmpp_component),
+    commands{}
+  { }
+  ~AdhocCommandsHandler() = default;
+
+  AdhocCommandsHandler(const AdhocCommandsHandler&) = delete;
+  AdhocCommandsHandler(AdhocCommandsHandler&&) = delete;
+  AdhocCommandsHandler& operator=(const AdhocCommandsHandler&) = delete;
+  AdhocCommandsHandler& operator=(AdhocCommandsHandler&&) = delete;
+
+  /**
+   * Returns the list of available commands.
+   */
+  const std::map<const std::string, const AdhocCommand>& get_commands() const;
+  /**
+   * Add a command into the list, associated with the given name
+   */
+  void add_command(std::string name, AdhocCommand command);
+  /**
+   * Find the requested command, create a new session or use an existing
+   * one, and process the request (provide a new form, an error, or a
+   * result).
+   *
+   * Returns a (moved) XmlNode that will be inserted in the iq response. It
+   * should be a <command/> node containing one or more useful children. If
+   * it contains an <error/> node, the iq response will have an error type.
+   *
+   * Takes a copy of the <command/> node so we can actually edit it and use
+   * it as our return value.
+   */
+  XmlNode handle_request(const std::string& executor_jid, const std::string& to, XmlNode command_node);
+  /**
+   * Remove the session from the list. This is done to avoid filling the
+   * memory with waiting session (for example due to a client that starts
+   * multi-steps command but never finishes them).
+   */
+  void remove_session(const std::string& session_id, const std::string& initiator_jid);
+private:
+  /**
+   * To access basically anything in the gateway.
+   */
+  XmppComponent& xmpp_component;
+  /**
+   * The list of all available commands.
+   */
+  std::map<const std::string, const AdhocCommand> commands;
+  /**
+   * The list of all currently on-going commands.
+   *
+   * Of the form: {{session_id, owner_jid}, session}.
+   */
+  std::map<std::pair<const std::string, const std::string>, AdhocSession> sessions;
+};
diff --git a/src/xmpp/adhoc_session.cpp b/src/xmpp/adhoc_session.cpp
new file mode 100644
index 0000000..dda4bea
--- /dev/null
+++ b/src/xmpp/adhoc_session.cpp
@@ -0,0 +1,35 @@
+#include <xmpp/adhoc_session.hpp>
+#include <xmpp/adhoc_command.hpp>
+
+#include <assert.h>
+
+AdhocSession::AdhocSession(const AdhocCommand& command, const std::string& owner_jid,
+                           const std::string& to_jid):
+  command(command),
+  owner_jid(owner_jid),
+  to_jid(to_jid),
+  current_step(0),
+  terminated(false)
+{
+}
+
+const AdhocStep& AdhocSession::get_next_step()
+{
+  assert(this->current_step < this->command.callbacks.size());
+  return this->command.callbacks[this->current_step++];
+}
+
+size_t AdhocSession::remaining_steps() const
+{
+  return this->command.callbacks.size() - this->current_step;
+}
+
+bool AdhocSession::is_terminated() const
+{
+  return this->terminated;
+}
+
+void AdhocSession::terminate()
+{
+  this->terminated = true;
+}
diff --git a/src/xmpp/adhoc_session.hpp b/src/xmpp/adhoc_session.hpp
new file mode 100644
index 0000000..0de8d13
--- /dev/null
+++ b/src/xmpp/adhoc_session.hpp
@@ -0,0 +1,88 @@
+#pragma once
+
+#include <xmpp/xmpp_stanza.hpp>
+
+#include <functional>
+#include <string>
+#include <map>
+
+class XmppComponent;
+
+class AdhocCommand;
+class AdhocSession;
+
+/**
+ * A function executed as an ad-hoc command step. It takes a <command/>
+ * XmlNode and modifies it accordingly (inserting for example an <error/>
+ * node, or a data form…).
+ */
+using AdhocStep = std::function<void(XmppComponent&, AdhocSession&, XmlNode&)>;
+
+class AdhocSession
+{
+public:
+  explicit AdhocSession(const AdhocCommand& command, const std::string& owner_jid,
+                        const std::string& to_jid);
+  ~AdhocSession() = default;
+
+  AdhocSession(const AdhocSession&) = delete;
+  AdhocSession(AdhocSession&&) = delete;
+  AdhocSession& operator=(const AdhocSession&) = delete;
+  AdhocSession& operator=(AdhocSession&&) = delete;
+
+  /**
+   * Return the function to be executed, found in our AdhocCommand, for the
+   * current_step. And increment the current_step.
+   */
+  const AdhocStep& get_next_step();
+  /**
+   * Return the number of remaining steps.
+   */
+  size_t remaining_steps() const;
+  /**
+   * This may be modified by an AdhocStep, to indicate that this session
+   * should no longer exist, because we encountered an error, and we can't
+   * execute any more step of it.
+   */
+  void terminate();
+  bool is_terminated() const;
+  std::string get_target_jid() const
+  {
+    return this->to_jid;
+  }
+  std::string get_owner_jid() const
+  {
+    return this->owner_jid;
+  }
+
+private:
+  /**
+   * A reference of the command concerned by this session. Used for example
+   * to get the next step of that command, things like that.
+   */
+  const AdhocCommand& command;
+  /**
+   * The full JID of the XMPP user that created this session by executing
+   * the first step of a command. Only that JID must be allowed to access
+   * this session.
+   */
+  const std::string& owner_jid;
+  /**
+   * The 'to' attribute in the request stanza.  This is the target of the current session.
+   */
+  const std::string& to_jid;
+  /**
+   * The current step we are at. It starts at zero. It is used to index the
+   * associated AdhocCommand::callbacks vector.
+   */
+  size_t current_step;
+  bool terminated;
+
+public:
+  /**
+   * A map to store various things that we may want to remember between two
+   * steps of the same session. A step can insert any value associated to
+   * any key in there.
+   */
+  std::map<std::string, std::string> vars;
+};
diff --git a/src/xmpp/auth.cpp b/src/xmpp/auth.cpp
new file mode 100644
index 0000000..8a34a4e
--- /dev/null
+++ b/src/xmpp/auth.cpp
@@ -0,0 +1,8 @@
+#include <xmpp/auth.hpp>
+
+#include <utils/sha1.hpp>
+
+std::string get_handshake_digest(const std::string& stream_id, const std::string& secret)
+{
+  return sha1(stream_id + secret);
+}
diff --git a/src/xmpp/auth.hpp b/src/xmpp/auth.hpp
new file mode 100644
index 0000000..34a2116
--- /dev/null
+++ b/src/xmpp/auth.hpp
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <string>
+
+std::string get_handshake_digest(const std::string& stream_id, const std::string& secret);
+
diff --git a/src/xmpp/biboumi_component.cpp b/src/xmpp/biboumi_component.cpp
index 4ba5e65..1c0f65c 100644
--- a/src/xmpp/biboumi_component.cpp
+++ b/src/xmpp/biboumi_component.cpp
@@ -16,7 +16,6 @@
 
 #include <cstdlib>
 
-#include <louloulibs.h>
 #include <biboumi.h>
 
 #include <uuid/uuid.h>
diff --git a/src/xmpp/body.hpp b/src/xmpp/body.hpp
new file mode 100644
index 0000000..068d1a4
--- /dev/null
+++ b/src/xmpp/body.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+
+namespace Xmpp
+{
+// Contains:
+// - an XMPP-valid UTF-8 body
+// - an XML node representing the XHTML-IM body, or null
+  using body = std::tuple<const std::string, std::unique_ptr<XmlNode>>;
+}
+
+
diff --git a/src/xmpp/jid.cpp b/src/xmpp/jid.cpp
new file mode 100644
index 0000000..0751387
--- /dev/null
+++ b/src/xmpp/jid.cpp
@@ -0,0 +1,153 @@
+#include <xmpp/jid.hpp>
+#include <algorithm>
+#include <cstring>
+#include <map>
+
+#include <biboumi.h>
+#ifdef LIBIDN_FOUND
+ #include <stringprep.h>
+ #include <sys/types.h>
+ #include <sys/socket.h>
+ #include <netdb.h>
+ #include <utils/scopeguard.hpp>
+ #include <set>
+#endif
+
+#include <logger/logger.hpp>
+
+Jid::Jid(const std::string& jid)
+{
+  std::string::size_type slash = jid.find('/');
+  if (slash != std::string::npos)
+    {
+      this->resource = jid.substr(slash + 1);
+    }
+
+  std::string::size_type at = jid.find('@');
+  if (at != std::string::npos && at < slash)
+    {
+      this->local = jid.substr(0, at);
+      at++;
+    }
+  else
+    at = 0;
+
+  this->domain = jid.substr(at, slash - at);
+}
+
+static constexpr size_t max_jid_part_len = 1023;
+
+std::string jidprep(const std::string& original)
+{
+#ifdef LIBIDN_FOUND
+  using CacheType = std::map<std::string, std::string>;
+  static CacheType cache;
+  std::pair<CacheType::iterator, bool> cached = cache.insert({original, {}});
+  if (std::get<1>(cached) == false)
+    { // Insertion failed: the result is already in the cache, return it
+      return std::get<0>(cached)->second;
+    }
+
+  const std::string error_msg("Failed to convert " + original + " into a valid JID:");
+  Jid jid(original);
+
+  char local[max_jid_part_len] = {};
+  memcpy(local, jid.local.data(), std::min(max_jid_part_len, jid.local.size()));
+  Stringprep_rc rc = static_cast<Stringprep_rc>(::stringprep(local, max_jid_part_len,
+                     static_cast<Stringprep_profile_flags>(0), stringprep_xmpp_nodeprep));
+  if (rc != STRINGPREP_OK)
+  {
+    log_error(error_msg + stringprep_strerror(rc));
+    return "";
+  }
+
+  char domain[max_jid_part_len] = {};
+  memcpy(domain, jid.domain.data(), std::min(max_jid_part_len, jid.domain.size()));
+
+  {
+    // Using getaddrinfo, check if the domain part is a valid IPv4 (then use
+    // it as is), or IPv6 (surround it with []), or a domain name (run
+    // nameprep)
+    struct addrinfo hints;
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_flags = AI_NUMERICHOST;
+    hints.ai_family = AF_UNSPEC;
+
+    struct addrinfo* addr_res = nullptr;
+    const auto ret = ::getaddrinfo(domain, nullptr, &hints, &addr_res);
+    auto addrinfo_deleter = utils::make_scope_guard([addr_res] { if (addr_res) freeaddrinfo(addr_res); });
+    if (ret || !addr_res || (addr_res->ai_family != AF_INET && addr_res->ai_family != AF_INET6))
+      { // Not an IP, run nameprep on it
+        rc = static_cast<Stringprep_rc>(::stringprep(domain, max_jid_part_len,
+                                                     static_cast<Stringprep_profile_flags>(0), stringprep_nameprep));
+        if (rc != STRINGPREP_OK)
+          {
+            log_error(error_msg + stringprep_strerror(rc));
+            return "";
+          }
+
+        // Make sure it contains only allowed characters
+        using std::begin;
+        using std::end;
+        char* domain_end = domain + ::strlen(domain);
+        std::replace_if(std::begin(domain), domain + ::strlen(domain),
+                        [](const char c) -> bool
+                        {
+                          return !((c >= 'a' && c <= 'z') || c == '-' ||
+                                   (c >= '0' && c <= '9') || c == '.');
+                        }, '-');
+        // Make sure there are no doubled - or .
+        std::set<char> special_chars{'-', '.'};
+        domain_end = std::unique(begin(domain), domain + ::strlen(domain), [&special_chars](const char& a, const char& b) -> bool
+        {
+          return special_chars.count(a) && special_chars.count(b);
+        });
+        // remove leading and trailing -. if any
+        if (domain_end != domain && special_chars.count(*(domain_end - 1)))
+          --domain_end;
+        if (domain_end != domain && special_chars.count(domain[0]))
+          {
+            std::memmove(domain, domain + 1, domain_end - domain + 1);
+            --domain_end;
+          }
+        // And if the final result is an empty string, return a dummy hostname
+        if (domain_end == domain)
+          ::strcpy(domain, "empty");
+        else
+          *domain_end = '\0';
+      }
+    else if (addr_res->ai_family == AF_INET6)
+      { // IPv6, surround it with []. The length is always enough:
+        // the longest possible IPv6 is way shorter than max_jid_part_len
+        ::memmove(domain + 1, domain, jid.domain.size());
+        domain[0] = '[';
+        domain[jid.domain.size() + 1] = ']';
+      }
+  }
+
+
+  // If there is no resource, stop here
+  if (jid.resource.empty())
+    {
+      std::get<0>(cached)->second = std::string(local) + "@" + domain;
+      return std::get<0>(cached)->second;
+    }
+
+  // Otherwise, also process the resource part
+  char resource[max_jid_part_len] = {};
+  memcpy(resource, jid.resource.data(), std::min(max_jid_part_len, jid.resource.size()));
+  rc = static_cast<Stringprep_rc>(::stringprep(resource, max_jid_part_len,
+       static_cast<Stringprep_profile_flags>(0), stringprep_xmpp_resourceprep));
+  if (rc != STRINGPREP_OK)
+    {
+      log_error(error_msg + stringprep_strerror(rc));
+      return "";
+    }
+  std::get<0>(cached)->second = std::string(local) + "@" + domain + "/" + resource;
+  return std::get<0>(cached)->second;
+
+#else
+  (void)original;
+  return "";
+#endif
+}
diff --git a/src/xmpp/jid.hpp b/src/xmpp/jid.hpp
new file mode 100644
index 0000000..85e835c
--- /dev/null
+++ b/src/xmpp/jid.hpp
@@ -0,0 +1,49 @@
+#pragma once
+
+
+#include <string>
+
+/**
+ * Parse a JID into its different subart
+ */
+class Jid
+{
+public:
+  explicit Jid(const std::string& jid);
+
+  Jid(const Jid&) = delete;
+  Jid(Jid&&) = delete;
+  Jid& operator=(const Jid&) = delete;
+  Jid& operator=(Jid&&) = delete;
+
+  std::string domain;
+  std::string local;
+  std::string resource;
+
+  std::string bare() const
+  {
+    return this->local + "@" + this->domain;
+  }
+  std::string full() const
+  {
+    std::string res = this->domain;
+    if (!this->local.empty())
+      res = this->local + "@" + this->domain;
+    if (!this->resource.empty())
+      res += "/" + this->resource;
+    return res;
+  }
+};
+
+/**
+ * Prepare the given UTF-8 string according to the XMPP node stringprep
+ * identifier profile.  This is used to send properly-formed JID to the XMPP
+ * server.
+ *
+ * If the stringprep library is not found, we return an empty string.  When
+ * this function is used, the result must always be checked for an empty
+ * value, and if this is the case it must not be used as a JID.
+ */
+std::string jidprep(const std::string& original);
+
+
diff --git a/src/xmpp/xmpp_component.cpp b/src/xmpp/xmpp_component.cpp
new file mode 100644
index 0000000..1453b18
--- /dev/null
+++ b/src/xmpp/xmpp_component.cpp
@@ -0,0 +1,672 @@
+#include <utils/timed_events.hpp>
+#include <utils/scopeguard.hpp>
+#include <utils/tolower.hpp>
+#include <logger/logger.hpp>
+
+#include <xmpp/xmpp_component.hpp>
+#include <config/config.hpp>
+#include <utils/system.hpp>
+#include <utils/time.hpp>
+#include <xmpp/auth.hpp>
+#include <xmpp/jid.hpp>
+
+#include <stdexcept>
+#include <iostream>
+#include <set>
+
+#include <uuid/uuid.h>
+
+#include <cstdlib>
+#include <set>
+
+#include <biboumi.h>
+#ifdef SYSTEMD_FOUND
+# include <systemd/sd-daemon.h>
+#endif
+
+using namespace std::string_literals;
+
+static std::set<std::string> kickable_errors{
+    "gone",
+    "internal-server-error",
+    "item-not-found",
+    "jid-malformed",
+    "recipient-unavailable",
+    "redirect",
+    "remote-server-not-found",
+    "remote-server-timeout",
+    "service-unavailable",
+    "malformed-error"
+    };
+
+XmppComponent::XmppComponent(std::shared_ptr<Poller>& poller, const std::string& hostname, const std::string& secret):
+  TCPClientSocketHandler(poller),
+  ever_auth(false),
+  first_connection_try(true),
+  secret(secret),
+  authenticated(false),
+  doc_open(false),
+  served_hostname(hostname),
+  stanza_handlers{},
+  adhoc_commands_handler(*this)
+{
+  this->parser.add_stream_open_callback(std::bind(&XmppComponent::on_remote_stream_open, this,
+                                                  std::placeholders::_1));
+  this->parser.add_stanza_callback(std::bind(&XmppComponent::on_stanza, this,
+                                                  std::placeholders::_1));
+  this->parser.add_stream_close_callback(std::bind(&XmppComponent::on_remote_stream_close, this,
+                                                  std::placeholders::_1));
+  this->stanza_handlers.emplace("handshake",
+                                std::bind(&XmppComponent::handle_handshake, this,std::placeholders::_1));
+  this->stanza_handlers.emplace("error",
+                                std::bind(&XmppComponent::handle_error, this,std::placeholders::_1));
+}
+
+void XmppComponent::start()
+{
+  this->connect(Config::get("xmpp_server_ip", "127.0.0.1"), Config::get("port", "5347"), false);
+}
+
+bool XmppComponent::is_document_open() const
+{
+  return this->doc_open;
+}
+
+void XmppComponent::send_stanza(const Stanza& stanza)
+{
+  std::string str = stanza.to_string();
+  log_debug("XMPP SENDING: ", str);
+  this->send_data(std::move(str));
+}
+
+void XmppComponent::on_connection_failed(const std::string& reason)
+{
+  this->first_connection_try = false;
+  log_error("Failed to connect to the XMPP server: ", reason);
+#ifdef SYSTEMD_FOUND
+  sd_notifyf(0, "STATUS=Failed to connect to the XMPP server: %s", reason.data());
+#endif
+}
+
+void XmppComponent::on_connected()
+{
+  log_info("connected to XMPP server");
+  this->first_connection_try = true;
+  auto data = "<stream:stream to='"s + this->served_hostname + \
+    "' xmlns:stream='http://etherx.jabber.org/streams' xmlns='" COMPONENT_NS "'>";
+  log_debug("XMPP SENDING: ", data);
+  this->send_data(std::move(data));
+  this->doc_open = true;
+  // We may have some pending data to send: this happens when we try to send
+  // some data before we are actually connected.  We send that data right now, if any
+  this->send_pending_data();
+}
+
+void XmppComponent::on_connection_close(const std::string& error)
+{
+  if (error.empty())
+    log_info("XMPP server closed connection");
+  else
+    log_info("XMPP server closed connection: ", error);
+}
+
+void XmppComponent::parse_in_buffer(const size_t size)
+{
+  if (!this->in_buf.empty())
+    { // This may happen if the parser could not allocate enough space for
+      // us. We try to feed it the data that was read into our in_buf
+      // instead. If this fails again we are in trouble.
+      this->parser.feed(this->in_buf.data(), this->in_buf.size(), false);
+      this->in_buf.clear();
+    }
+  else
+    { // Just tell the parser to parse the data that was placed into the
+      // buffer it provided to us with GetBuffer
+      this->parser.parse(size, false);
+    }
+}
+
+void XmppComponent::on_remote_stream_open(const XmlNode& node)
+{
+  log_debug("XMPP RECEIVING: ", node.to_string());
+  this->stream_id = node.get_tag("id");
+  if (this->stream_id.empty())
+    {
+      log_error("Error: no attribute 'id' found");
+      this->send_stream_error("bad-format", "missing 'id' attribute");
+      this->close_document();
+      return ;
+    }
+
+  // Try to authenticate
+  auto data = "<handshake xmlns='" COMPONENT_NS "'>"s + get_handshake_digest(this->stream_id, this->secret) + "</handshake>";
+  log_debug("XMPP SENDING: ", data);
+  this->send_data(std::move(data));
+}
+
+void XmppComponent::on_remote_stream_close(const XmlNode& node)
+{
+  log_debug("XMPP RECEIVING: ", node.to_string());
+  this->doc_open = false;
+}
+
+void XmppComponent::reset()
+{
+  this->parser.reset();
+}
+
+void XmppComponent::on_stanza(const Stanza& stanza)
+{
+  log_debug("XMPP RECEIVING: ", stanza.to_string());
+  std::function<void(const Stanza&)> handler;
+  try
+    {
+      handler = this->stanza_handlers.at(stanza.get_name());
+    }
+  catch (const std::out_of_range& exception)
+    {
+      log_warning("No handler for stanza of type ", stanza.get_name());
+      return;
+    }
+  handler(stanza);
+}
+
+void XmppComponent::send_stream_error(const std::string& name, const std::string& explanation)
+{
+  Stanza node("stream:error");
+  {
+    XmlSubNode error(node, name);
+    error["xmlns"] = STREAM_NS;
+    if (!explanation.empty())
+      error.set_inner(explanation);
+  }
+  this->send_stanza(node);
+}
+
+void XmppComponent::send_stanza_error(const std::string& kind, const std::string& to, const std::string& from,
+                                      const std::string& id, const std::string& error_type,
+                                      const std::string& defined_condition, const std::string& text,
+                                      const bool fulljid)
+{
+  Stanza node(kind);
+  {
+    if (!to.empty())
+      node["to"] = to;
+    if (!from.empty())
+      {
+        if (fulljid)
+          node["from"] = from;
+        else
+          node["from"] = from + "@" + this->served_hostname;
+      }
+    if (!id.empty())
+      node["id"] = id;
+    node["type"] = "error";
+    {
+      XmlSubNode error(node, "error");
+      error["type"] = error_type;
+      {
+        XmlSubNode inner_error(error, defined_condition);
+        inner_error["xmlns"] = STANZA_NS;
+      }
+      if (!text.empty())
+        {
+          XmlSubNode text_node(error, "text");
+          text_node["xmlns"] = STANZA_NS;
+          text_node.set_inner(text);
+        }
+    }
+  }
+  this->send_stanza(node);
+}
+
+void XmppComponent::close_document()
+{
+  log_debug("XMPP SENDING: </stream:stream>");
+  this->send_data("</stream:stream>");
+  this->doc_open = false;
+}
+
+void XmppComponent::handle_handshake(const Stanza&)
+{
+  this->authenticated = true;
+  this->ever_auth = true;
+  log_info("Authenticated with the XMPP server");
+#ifdef SYSTEMD_FOUND
+  sd_notify(0, "READY=1");
+  // Install an event that sends a keepalive to systemd.  If biboumi crashes
+  // or hangs for too long, systemd will restart it.
+  uint64_t usec;
+  if (sd_watchdog_enabled(0, &usec) > 0)
+    {
+      TimedEventsManager::instance().add_event(TimedEvent(
+             std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::microseconds(usec / 2)),
+             []() { sd_notify(0, "WATCHDOG=1"); }));
+    }
+#endif
+  this->after_handshake();
+}
+
+void XmppComponent::handle_error(const Stanza& stanza)
+{
+  const XmlNode* text = stanza.get_child("text", STREAMS_NS);
+  std::string error_message("Unspecified error");
+  if (text)
+    error_message = text->get_inner();
+  log_error("Stream error received from the XMPP server: ", error_message);
+#ifdef SYSTEMD_FOUND
+  if (!this->ever_auth)
+    sd_notifyf(0, "STATUS=Failed to authenticate to the XMPP server: %s", error_message.data());
+#endif
+
+}
+
+void* XmppComponent::get_receive_buffer(const size_t size) const
+{
+  return this->parser.get_buffer(size);
+}
+
+void XmppComponent::send_message(const std::string& from, Xmpp::body&& body, const std::string& to,
+                                 const std::string& type, const bool fulljid, const bool nocopy)
+{
+  Stanza message("message");
+  {
+    message["to"] = to;
+    if (fulljid)
+      message["from"] = from;
+    else
+      message["from"] = from + "@" + this->served_hostname;
+    if (!type.empty())
+      message["type"] = type;
+    XmlSubNode body_node(message, "body");
+    body_node.set_inner(std::get<0>(body));
+    if (std::get<1>(body))
+      {
+        XmlSubNode html(message, "html");
+        html["xmlns"] = XHTMLIM_NS;
+        // Pass the ownership of the pointer to this xmlnode
+        html.add_child(std::move(std::get<1>(body)));
+      }
+    if (nocopy)
+      {
+        XmlSubNode private_node(message, "private");
+        private_node["xmlns"] = "urn:xmpp:carbons:2";
+        XmlSubNode nocopy(message, "no-copy");
+        nocopy["xmlns"] = "urn:xmpp:hints";
+      }
+  }
+  this->send_stanza(message);
+}
+
+void XmppComponent::send_user_join(const std::string& from,
+                                   const std::string& nick,
+                                   const std::string& realjid,
+                                   const std::string& affiliation,
+                                   const std::string& role,
+                                   const std::string& to,
+                                   const bool self)
+{
+  Stanza presence("presence");
+  {
+    presence["to"] = to;
+    presence["from"] = from + "@" + this->served_hostname + "/" + nick;
+
+    XmlSubNode x(presence, "x");
+    x["xmlns"] = MUC_USER_NS;
+
+    XmlSubNode item(x, "item");
+    if (!affiliation.empty())
+      item["affiliation"] = affiliation;
+    if (!role.empty())
+      item["role"] = role;
+    if (!realjid.empty())
+      {
+        const std::string preped_jid = jidprep(realjid);
+        if (!preped_jid.empty())
+          item["jid"] = preped_jid;
+      }
+
+    if (self)
+      {
+        XmlSubNode status(x, "status");
+        status["code"] = "110";
+      }
+  }
+  this->send_stanza(presence);
+}
+
+void XmppComponent::send_invalid_room_error(const std::string& muc_name,
+                                            const std::string& nick,
+                                            const std::string& to)
+{
+  Stanza presence("presence");
+  {
+    if (!muc_name.empty ())
+      presence["from"] = muc_name + "@" + this->served_hostname + "/" + nick;
+    else
+      presence["from"] = this->served_hostname;
+    presence["to"] = to;
+    presence["type"] = "error";
+    XmlSubNode x(presence, "x");
+    x["xmlns"] = MUC_NS;
+    XmlSubNode error(presence, "error");
+    error["by"] = muc_name + "@" + this->served_hostname;
+    error["type"] = "cancel";
+    XmlSubNode item_not_found(error, "item-not-found");
+    item_not_found["xmlns"] = STANZA_NS;
+    XmlSubNode text(error, "text");
+    text["xmlns"] = STANZA_NS;
+    text["xml:lang"] = "en";
+    text.set_inner(muc_name +
+                   " is not a valid IRC channel name. A correct room jid is of the form: #<chan>%<server>@" +
+                   this->served_hostname);
+  }
+  this->send_stanza(presence);
+}
+
+void XmppComponent::send_topic(const std::string& from, Xmpp::body&& topic, const std::string& to, const std::string& who)
+{
+  Stanza message("message");
+  {
+    message["to"] = to;
+    if (who.empty())
+      message["from"] = from + "@" + this->served_hostname;
+    else
+      message["from"] = from + "@" + this->served_hostname + "/" + who;
+    message["type"] = "groupchat";
+    XmlSubNode subject(message, "subject");
+    subject.set_inner(std::get<0>(topic));
+  }
+  this->send_stanza(message);
+}
+
+void XmppComponent::send_muc_message(const std::string& muc_name, const std::string& nick, Xmpp::body&& xmpp_body, const std::string& jid_to)
+{
+  Stanza message("message");
+  message["to"] = jid_to;
+  if (!nick.empty())
+    message["from"] = muc_name + "@" + this->served_hostname + "/" + nick;
+  else // Message from the room itself
+    message["from"] = muc_name + "@" + this->served_hostname;
+  message["type"] = "groupchat";
+
+  {
+    XmlSubNode body(message, "body");
+    body.set_inner(std::get<0>(xmpp_body));
+  }
+
+  if (std::get<1>(xmpp_body))
+    {
+      XmlSubNode html(message, "html");
+      html["xmlns"] = XHTMLIM_NS;
+      // Pass the ownership of the pointer to this xmlnode
+      html.add_child(std::move(std::get<1>(xmpp_body)));
+    }
+  this->send_stanza(message);
+}
+
+void XmppComponent::send_history_message(const std::string& muc_name, const std::string& nick, const std::string& body_txt, const std::string& jid_to, std::time_t timestamp)
+{
+  Stanza message("message");
+  message["to"] = jid_to;
+  if (!nick.empty())
+    message["from"] = muc_name + "@" + this->served_hostname + "/" + nick;
+  else
+    message["from"] = muc_name + "@" + this->served_hostname;
+  message["type"] = "groupchat";
+
+  {
+    XmlSubNode body(message, "body");
+    body.set_inner(body_txt);
+  }
+  {
+    XmlSubNode delay(message, "delay");
+    delay["xmlns"] = DELAY_NS;
+    delay["from"] = muc_name + "@" + this->served_hostname;
+    delay["stamp"] = utils::to_string(timestamp);
+  }
+
+  this->send_stanza(message);
+}
+
+void XmppComponent::send_muc_leave(const std::string& muc_name, std::string&& nick, Xmpp::body&& message, const std::string& jid_to, const bool self)
+{
+  Stanza presence("presence");
+  {
+    presence["to"] = jid_to;
+    presence["from"] = muc_name + "@" + this->served_hostname + "/" + nick;
+    presence["type"] = "unavailable";
+    const std::string message_str = std::get<0>(message);
+    XmlSubNode x(presence, "x");
+    x["xmlns"] = MUC_USER_NS;
+    if (self)
+      {
+        XmlSubNode status(x, "status");
+        status["code"] = "110";
+      }
+    if (!message_str.empty())
+      {
+        XmlSubNode status(presence, "status");
+        status.set_inner(message_str);
+      }
+  }
+  this->send_stanza(presence);
+}
+
+void XmppComponent::send_nick_change(const std::string& muc_name,
+                                     const std::string& old_nick,
+                                     const std::string& new_nick,
+                                     const std::string& affiliation,
+                                     const std::string& role,
+                                     const std::string& jid_to,
+                                     const bool self)
+{
+  Stanza presence("presence");
+  {
+    presence["to"] = jid_to;
+    presence["from"] = muc_name + "@" + this->served_hostname + "/" + old_nick;
+    presence["type"] = "unavailable";
+    XmlSubNode x(presence, "x");
+    x["xmlns"] = MUC_USER_NS;
+    XmlSubNode item(x, "item");
+    item["nick"] = new_nick;
+    XmlSubNode status(x, "status");
+    status["code"] = "303";
+    if (self)
+      {
+        XmlSubNode status(x, "status");
+        status["code"] = "110";
+      }
+  }
+  this->send_stanza(presence);
+
+  this->send_user_join(muc_name, new_nick, "", affiliation, role, jid_to, self);
+}
+
+void XmppComponent::kick_user(const std::string& muc_name, const std::string& target, const std::string& txt,
+                              const std::string& author, const std::string& jid_to, const bool self)
+{
+  Stanza presence("presence");
+  {
+    presence["from"] = muc_name + "@" + this->served_hostname + "/" + target;
+    presence["to"] = jid_to;
+    presence["type"] = "unavailable";
+    XmlSubNode x(presence, "x");
+    x["xmlns"] = MUC_USER_NS;
+    XmlSubNode item(x, "item");
+    item["affiliation"] = "none";
+    item["role"] = "none";
+    XmlSubNode actor(item, "actor");
+    actor["nick"] = author;
+    actor["jid"] = author; // backward compatibility with old clients
+    XmlSubNode reason(item, "reason");
+    reason.set_inner(txt);
+    XmlSubNode status(x, "status");
+    status["code"] = "307";
+    if (self)
+      {
+        XmlSubNode status(x, "status");
+        status["code"] = "110";
+      }
+  }
+  this->send_stanza(presence);
+}
+
+void XmppComponent::send_presence_error(const std::string& muc_name,
+                                        const std::string& nickname,
+                                        const std::string& jid_to,
+                                        const std::string& type,
+                                        const std::string& condition,
+                                        const std::string& error_code,
+                                        const std::string& text)
+{
+  Stanza presence("presence");
+  {
+    presence["from"] = muc_name + "@" + this->served_hostname + "/" + nickname;
+    presence["to"] = jid_to;
+    presence["type"] = "error";
+    XmlSubNode x(presence, "x");
+    x["xmlns"] = MUC_NS;
+    XmlSubNode error(presence, "error");
+    error["by"] = muc_name + "@" + this->served_hostname;
+    error["type"] = type;
+    if (!text.empty())
+      {
+        XmlSubNode text_node(error, "text");
+        text_node["xmlns"] = STANZA_NS;
+        text_node.set_inner(text);
+      }
+    if (!error_code.empty())
+      error["code"] = error_code;
+    XmlSubNode subnode(error, condition);
+    subnode["xmlns"] = STANZA_NS;
+  }
+  this->send_stanza(presence);
+}
+
+void XmppComponent::send_affiliation_role_change(const std::string& muc_name,
+                                                 const std::string& target,
+                                                 const std::string& affiliation,
+                                                 const std::string& role,
+                                                 const std::string& jid_to)
+{
+  Stanza presence("presence");
+  {
+    presence["from"] = muc_name + "@" + this->served_hostname + "/" + target;
+    presence["to"] = jid_to;
+    XmlSubNode x(presence, "x");
+    x["xmlns"] = MUC_USER_NS;
+    XmlSubNode item(x, "item");
+    item["affiliation"] = affiliation;
+    item["role"] = role;
+  }
+  this->send_stanza(presence);
+}
+
+void XmppComponent::send_version(const std::string& id, const std::string& jid_to, const std::string& jid_from,
+                                 const std::string& version)
+{
+  Stanza iq("iq");
+  iq["type"] = "result";
+  iq["id"] = id;
+  iq["to"] = jid_to;
+  iq["from"] = jid_from;
+  {
+    XmlSubNode query(iq, "query");
+    query["xmlns"] = VERSION_NS;
+    if (version.empty())
+      {
+        {
+          XmlSubNode name(query, "name");
+          name.set_inner("biboumi");
+        }
+        {
+          XmlSubNode version(query, "version");
+          version.set_inner(SOFTWARE_VERSION);
+        }
+        {
+          XmlSubNode os(query, "os");
+          os.set_inner(utils::get_system_name());
+        }
+    }
+    else
+    {
+      XmlSubNode name(query, "name");
+      name.set_inner(version);
+    }
+  }
+  this->send_stanza(iq);
+}
+
+void XmppComponent::send_adhoc_commands_list(const std::string& id, const std::string& requester_jid,
+                                             const std::string& from_jid,
+                                             const bool with_admin_only, const AdhocCommandsHandler& adhoc_handler)
+{
+  Stanza iq("iq");
+  {
+    iq["type"] = "result";
+    iq["id"] = id;
+    iq["to"] = requester_jid;
+    iq["from"] = from_jid;
+    XmlSubNode query(iq, "query");
+    query["xmlns"] = DISCO_ITEMS_NS;
+    query["node"] = ADHOC_NS;
+    for (const auto &kv: adhoc_handler.get_commands())
+      {
+        if (kv.second.is_admin_only() && !with_admin_only)
+          continue;
+        XmlSubNode item(query, "item");
+        item["jid"] = from_jid;
+        item["node"] = kv.first;
+        item["name"] = kv.second.name;
+      }
+  }
+  this->send_stanza(iq);
+}
+
+void XmppComponent::send_iq_version_request(const std::string& from,
+                                            const std::string& jid_to)
+{
+  Stanza iq("iq");
+  {
+    iq["type"] = "get";
+    iq["id"] = "version_"s + XmppComponent::next_id();
+    iq["from"] = from + "@" + this->served_hostname;
+    iq["to"] = jid_to;
+    XmlSubNode query(iq, "query");
+    query["xmlns"] = VERSION_NS;
+  }
+  this->send_stanza(iq);
+}
+
+void XmppComponent::send_iq_result_full_jid(const std::string& id, const std::string& to_jid, const std::string& from_full_jid)
+{
+  Stanza iq("iq");
+  iq["from"] = from_full_jid;
+  iq["to"] = to_jid;
+  iq["id"] = id;
+  iq["type"] = "result";
+  this->send_stanza(iq);
+}
+
+void XmppComponent::send_iq_result(const std::string& id, const std::string& to_jid, const std::string& from_local_part)
+{
+  Stanza iq("iq");
+  if (!from_local_part.empty())
+    iq["from"] = from_local_part + "@" + this->served_hostname;
+  else
+    iq["from"] = this->served_hostname;
+  iq["to"] = to_jid;
+  iq["id"] = id;
+  iq["type"] = "result";
+  this->send_stanza(iq);
+}
+
+std::string XmppComponent::next_id()
+{
+  char uuid_str[37];
+  uuid_t uuid;
+  uuid_generate(uuid);
+  uuid_unparse(uuid, uuid_str);
+  return uuid_str;
+}
diff --git a/src/xmpp/xmpp_component.hpp b/src/xmpp/xmpp_component.hpp
new file mode 100644
index 0000000..16d7480
--- /dev/null
+++ b/src/xmpp/xmpp_component.hpp
@@ -0,0 +1,245 @@
+#pragma once
+
+
+#include <xmpp/adhoc_commands_handler.hpp>
+#include <network/tcp_client_socket_handler.hpp>
+#include <xmpp/xmpp_parser.hpp>
+#include <xmpp/body.hpp>
+
+#include <unordered_map>
+#include <memory>
+#include <string>
+#include <ctime>
+#include <map>
+
+#define STREAM_NS        "http://etherx.jabber.org/streams"
+#define COMPONENT_NS     "jabber:component:accept"
+#define MUC_NS           "http://jabber.org/protocol/muc"
+#define MUC_USER_NS      MUC_NS"#user"
+#define MUC_ADMIN_NS     MUC_NS"#admin"
+#define DISCO_NS         "http://jabber.org/protocol/disco"
+#define DISCO_ITEMS_NS   DISCO_NS"#items"
+#define DISCO_INFO_NS    DISCO_NS"#info"
+#define XHTMLIM_NS       "http://jabber.org/protocol/xhtml-im"
+#define STANZA_NS        "urn:ietf:params:xml:ns:xmpp-stanzas"
+#define STREAMS_NS       "urn:ietf:params:xml:ns:xmpp-streams"
+#define VERSION_NS       "jabber:iq:version"
+#define ADHOC_NS         "http://jabber.org/protocol/commands"
+#define PING_NS          "urn:xmpp:ping"
+#define DELAY_NS         "urn:xmpp:delay"
+#define MAM_NS           "urn:xmpp:mam:1"
+#define FORWARD_NS       "urn:xmpp:forward:0"
+#define CLIENT_NS        "jabber:client"
+#define DATAFORM_NS      "jabber:x:data"
+#define RSM_NS           "http://jabber.org/protocol/rsm"
+#define MUC_TRAFFIC_NS   "http://jabber.org/protocol/muc#traffic"
+
+/**
+ * An XMPP component, communicating with an XMPP server using the protocole
+ * described in XEP-0114: Jabber Component Protocol
+ *
+ * TODO: implement XEP-0225: Component Connections
+ */
+class XmppComponent: public TCPClientSocketHandler
+{
+public:
+  explicit XmppComponent(std::shared_ptr<Poller>& poller, const std::string& hostname, const std::string& secret);
+  virtual ~XmppComponent() = default;
+
+  XmppComponent(const XmppComponent&) = delete;
+  XmppComponent(XmppComponent&&) = delete;
+  XmppComponent& operator=(const XmppComponent&) = delete;
+  XmppComponent& operator=(XmppComponent&&) = delete;
+
+  void on_connection_failed(const std::string& reason) override final;
+  void on_connected() override final;
+  void on_connection_close(const std::string& error) override final;
+  void parse_in_buffer(const size_t size) override final;
+
+  /**
+   * Returns a unique id, to be used in the 'id' element of our iq stanzas.
+   */
+  static std::string next_id();
+  bool is_document_open() const;
+  /**
+   * Connect to the XMPP server.
+   */
+  void start();
+  /**
+   * Reset the component so we can use the component on a new XMPP stream
+   */
+  void reset();
+  /**
+   * Serialize the stanza and add it to the out_buf to be sent to the
+   * server.
+   */
+  void send_stanza(const Stanza& stanza);
+  /**
+   * Handle the opening of the remote stream
+   */
+  void on_remote_stream_open(const XmlNode& node);
+  /**
+   * Handle the closing of the remote stream
+   */
+  void on_remote_stream_close(const XmlNode& node);
+  /**
+   * Handle received stanzas
+   */
+  void on_stanza(const Stanza& stanza);
+  /**
+   * Send an error stanza. Message being the name of the element inside the
+   * stanza, and explanation being a short human-readable sentence
+   * describing the error.
+   */
+  void send_stream_error(const std::string& message, const std::string& explanation);
+  /**
+   * Send error stanza, described in http://xmpp.org/rfcs/rfc6120.html#stanzas-error
+   */
+  void send_stanza_error(const std::string& kind, const std::string& to, const std::string& from,
+                         const std::string& id, const std::string& error_type,
+                         const std::string& defined_condition, const std::string& text,
+                         const bool fulljid=true);
+  /**
+   * Send the closing signal for our document (not closing the connection though).
+   */
+  void close_document();
+  /**
+   * Send a message from from@served_hostname, with the given body
+   *
+   * If fulljid is false, the provided 'from' doesn't contain the
+   * server-part of the JID and must be added.
+   */
+  void send_message(const std::string& from, Xmpp::body&& body, const std::string& to,
+                    const std::string& type, const bool fulljid, const bool nocopy=false);
+  /**
+   * Send a join from a new participant
+   */
+  void send_user_join(const std::string& from,
+                      const std::string& nick,
+                      const std::string& realjid,
+                      const std::string& affiliation,
+                      const std::string& role,
+                      const std::string& to,
+                      const bool self);
+  /**
+   * Send an error to indicate that the user tried to join an invalid room
+   */
+  void send_invalid_room_error(const std::string& muc_jid,
+                               const std::string& nick,
+                               const std::string& to);
+  /**
+   * Send the MUC topic to the user
+   */
+  void send_topic(const std::string& from, Xmpp::body&& xmpp_topic, const std::string& to, const std::string& who);
+  /**
+   * Send a (non-private) message to the MUC
+   */
+  void send_muc_message(const std::string& muc_name, const std::string& nick, Xmpp::body&& body, const std::string& jid_to);
+  /**
+   * Send a message, with a <delay/> element, part of a MUC history
+   */
+  void send_history_message(const std::string& muc_name, const std::string& nick, const std::string& body,
+                            const std::string& jid_to, const std::time_t timestamp);
+  /**
+   * Send an unavailable presence for this nick
+   */
+  void send_muc_leave(const std::string& muc_name, std::string&& nick, Xmpp::body&& message, const std::string& jid_to, const bool self);
+  /**
+   * Indicate that a participant changed his nick
+   */
+  void send_nick_change(const std::string& muc_name,
+                        const std::string& old_nick,
+                        const std::string& new_nick,
+                        const std::string& affiliation,
+                        const std::string& role,
+                        const std::string& jid_to,
+                        const bool self);
+  /**
+   * An user is kicked from a room
+   */
+  void kick_user(const std::string& muc_name, const std::string& target, const std::string& reason,
+                 const std::string& author, const std::string& jid_to, const bool self);
+  /**
+   * Send a generic presence error
+   */
+  void send_presence_error(const std::string& muc_name,
+                           const std::string& nickname,
+                           const std::string& jid_to,
+                           const std::string& type,
+                           const std::string& condition,
+                           const std::string& error_code,
+                           const std::string& text);
+  /**
+   * Send a presence from the MUC indicating a change in the role and/or
+   * affiliation of a participant
+   */
+  void send_affiliation_role_change(const std::string& muc_name,
+                                    const std::string& target,
+                                    const std::string& affiliation,
+                                    const std::string& role,
+                                    const std::string& jid_to);
+  /**
+   * Send a result IQ with the given version, or the gateway version if the
+   * passed string is empty.
+   */
+  void send_version(const std::string& id, const std::string& jid_to, const std::string& jid_from,
+                    const std::string& version="");
+  /**
+   * Send the list of all available ad-hoc commands to that JID. The list is
+   * different depending on what JID made the request.
+   */
+  void send_adhoc_commands_list(const std::string& id, const std::string& requester_jid, const std::string& from_jid,
+                                const bool with_admin_only, const AdhocCommandsHandler& adhoc_handler);
+  /**
+   * Send an iq version request
+   */
+  void send_iq_version_request(const std::string& from,
+                               const std::string& jid_to);
+  /**
+   * Send an empty iq of type result
+   */
+  void send_iq_result(const std::string& id, const std::string& to_jid, const std::string& from);
+  void send_iq_result_full_jid(const std::string& id, const std::string& to_jid,
+                               const std::string& from_full_jid);
+
+  void handle_handshake(const Stanza& stanza);
+  void handle_error(const Stanza& stanza);
+
+  virtual void after_handshake() {}
+
+  const std::string& get_served_hostname() const
+  { return this->served_hostname; }
+
+  /**
+   * Whether or not we ever succeeded our authentication to the XMPP server
+   */
+  bool ever_auth;
+  /**
+   * Whether or not this is the first consecutive try on connecting to the
+   * XMPP server.  We use this to delay the connection attempt for a few
+   * seconds, if it is not the first try.
+   */
+  bool first_connection_try;
+
+private:
+  /**
+   * Return a buffer provided by the XML parser, to read data directly into
+   * it, and avoiding some unnecessary copy.
+   */
+  void* get_receive_buffer(const size_t size) const override final;
+  XmppParser parser;
+  std::string stream_id;
+  std::string secret;
+  bool authenticated;
+  /**
+   * Whether or not OUR XMPP document is open
+   */
+  bool doc_open;
+protected:
+  std::string served_hostname;
+
+  std::unordered_map<std::string, std::function<void(const Stanza&)>> stanza_handlers;
+  AdhocCommandsHandler adhoc_commands_handler;
+};
+
+
diff --git a/src/xmpp/xmpp_parser.cpp b/src/xmpp/xmpp_parser.cpp
new file mode 100644
index 0000000..0488be9
--- /dev/null
+++ b/src/xmpp/xmpp_parser.cpp
@@ -0,0 +1,172 @@
+#include <xmpp/xmpp_parser.hpp>
+#include <xmpp/xmpp_stanza.hpp>
+
+#include <logger/logger.hpp>
+
+/**
+ * Expat handlers. Called by the Expat library, never by ourself.
+ * They just forward the call to the XmppParser corresponding methods.
+ */
+
+static void start_element_handler(void* user_data, const XML_Char* name, const XML_Char** atts)
+{
+  static_cast<XmppParser*>(user_data)->start_element(name, atts);
+}
+
+static void end_element_handler(void* user_data, const XML_Char* name)
+{
+  static_cast<XmppParser*>(user_data)->end_element(name);
+}
+
+static void character_data_handler(void *user_data, const XML_Char *s, int len)
+{
+  static_cast<XmppParser*>(user_data)->char_data(s, len);
+}
+
+/**
+ * XmppParser class
+ */
+
+XmppParser::XmppParser():
+  level(0),
+  current_node(nullptr),
+  root(nullptr)
+{
+  this->init_xml_parser();
+}
+
+void XmppParser::init_xml_parser()
+{
+  // Create the expat parser
+  this->parser = XML_ParserCreateNS("UTF-8", ':');
+  XML_SetUserData(this->parser, static_cast<void*>(this));
+
+  // Install Expat handlers
+  XML_SetElementHandler(this->parser, &start_element_handler, &end_element_handler);
+  XML_SetCharacterDataHandler(this->parser, &character_data_handler);
+}
+
+XmppParser::~XmppParser()
+{
+  XML_ParserFree(this->parser);
+}
+
+int XmppParser::feed(const char* data, const int len, const bool is_final)
+{
+  int res = XML_Parse(this->parser, data, len, is_final);
+  if (res == XML_STATUS_ERROR &&
+      (XML_GetErrorCode(this->parser) != XML_ERROR_FINISHED))
+    log_error("Xml_Parse encountered an error: ",
+              XML_ErrorString(XML_GetErrorCode(this->parser)));
+  return res;
+}
+
+int XmppParser::parse(const int len, const bool is_final)
+{
+  int res = XML_ParseBuffer(this->parser, len, is_final);
+  if (res == XML_STATUS_ERROR)
+    log_error("Xml_Parsebuffer encountered an error: ",
+              XML_ErrorString(XML_GetErrorCode(this->parser)));
+  return res;
+}
+
+void XmppParser::reset()
+{
+  XML_ParserFree(this->parser);
+  this->init_xml_parser();
+  this->current_node = nullptr;
+  this->root.reset(nullptr);
+  this->level = 0;
+}
+
+void* XmppParser::get_buffer(const size_t size) const
+{
+  return XML_GetBuffer(this->parser, static_cast<int>(size));
+}
+
+void XmppParser::start_element(const XML_Char* name, const XML_Char** attribute)
+{
+  this->level++;
+
+  auto new_node = std::make_unique<XmlNode>(name, this->current_node);
+  auto new_node_ptr = new_node.get();
+  if (this->current_node)
+    this->current_node->add_child(std::move(new_node));
+  else
+    this->root = std::move(new_node);
+  this->current_node = new_node_ptr;
+  for (size_t i = 0; attribute[i]; i += 2)
+    this->current_node->set_attribute(attribute[i], attribute[i+1]);
+  if (this->level == 1)
+    this->stream_open_event(*this->current_node);
+}
+
+void XmppParser::end_element(const XML_Char*)
+{
+  this->level--;
+  if (this->level == 0)
+    { // End of the whole stream
+      this->stream_close_event(*this->current_node);
+      this->current_node = nullptr;
+      this->root.reset();
+    }
+  else
+    {
+      auto parent = this->current_node->get_parent();
+      if (this->level == 1)
+        { // End of a stanza
+          this->stanza_event(*this->current_node);
+          // Note: deleting all the children of our parent deletes ourself,
+          // so current_node is an invalid pointer after this line
+          parent->delete_all_children();
+        }
+      this->current_node = parent;
+    }
+}
+
+void XmppParser::char_data(const XML_Char* data, const size_t len)
+{
+  if (this->current_node->has_children())
+    this->current_node->get_last_child()->add_to_tail({data, len});
+  else
+    this->current_node->add_to_inner({data, len});
+}
+
+void XmppParser::stanza_event(const Stanza& stanza) const
+{
+  for (const auto& callback: this->stanza_callbacks)
+    {
+      try {
+        callback(stanza);
+      } catch (const std::exception& e) {
+        log_error("Unhandled exception: ", e.what());
+      }
+    }
+}
+
+void XmppParser::stream_open_event(const XmlNode& node) const
+{
+  for (const auto& callback: this->stream_open_callbacks)
+    callback(node);
+}
+
+void XmppParser::stream_close_event(const XmlNode& node) const
+{
+  for (const auto& callback: this->stream_close_callbacks)
+    callback(node);
+}
+
+void XmppParser::add_stanza_callback(std::function<void(const Stanza&)>&& callback)
+{
+  this->stanza_callbacks.emplace_back(std::move(callback));
+}
+
+void XmppParser::add_stream_open_callback(std::function<void(const XmlNode&)>&& callback)
+{
+  this->stream_open_callbacks.emplace_back(std::move(callback));
+}
+
+void XmppParser::add_stream_close_callback(std::function<void(const XmlNode&)>&& callback)
+{
+  this->stream_close_callbacks.emplace_back(std::move(callback));
+}
diff --git a/src/xmpp/xmpp_parser.hpp b/src/xmpp/xmpp_parser.hpp
new file mode 100644
index 0000000..9d67228
--- /dev/null
+++ b/src/xmpp/xmpp_parser.hpp
@@ -0,0 +1,133 @@
+#pragma once
+
+
+#include <xmpp/xmpp_stanza.hpp>
+
+#include <functional>
+
+#include <expat.h>
+
+/**
+ * A SAX XML parser that builds XML nodes and spawns events when a complete
+ * stanza is received (an element of level 2), or when the document is
+ * opened/closed (an element of level 1)
+ *
+ * After a stanza_event has been spawned, we delete the whole stanza. This
+ * means that even with a very long document (in XMPP the document is
+ * potentially infinite), the memory is never exhausted as long as each
+ * stanza is reasonnably short.
+ *
+ * The element names generated by expat contain the namespace of the
+ * element, a colon (':') and then the actual name of the element.  To get
+ * an element "x" with a namespace of "http://jabber.org/protocol/muc", you
+ * just look for an XmlNode named "http://jabber.org/protocol/muc:x"
+ *
+ * TODO: enforce the size-limit for the stanza (limit the number of childs
+ * it can contain). For example forbid the parser going further than level
+ * 20 (arbitrary number here), and each XML node to have more than 15 childs
+ * (arbitrary number again).
+ */
+class XmppParser
+{
+public:
+  explicit XmppParser();
+  ~XmppParser();
+  XmppParser(const XmppParser&) = delete;
+  XmppParser& operator=(const XmppParser&) = delete;
+  XmppParser(XmppParser&&) = delete;
+  XmppParser& operator=(XmppParser&&) = delete;
+
+public:
+  /**
+   * Feed the parser with some XML data
+   */
+  int feed(const char* data, const int len, const bool is_final);
+  /**
+   * Parse the data placed in the parser buffer
+   */
+  int parse(const int size, const bool is_final);
+  /**
+   * Reset the parser, so it can be used from scratch afterward
+   */
+  void reset();
+  /**
+   * Get a buffer provided by the xml parser.
+   */
+  void* get_buffer(const size_t size) const;
+  /**
+   * Add one callback for the various events that this parser can spawn.
+   */
+  void add_stanza_callback(std::function<void(const Stanza&)>&& callback);
+  void add_stream_open_callback(std::function<void(const XmlNode&)>&& callback);
+  void add_stream_close_callback(std::function<void(const XmlNode&)>&& callback);
+
+  /**
+   * Called when a new XML element has been opened. We instanciate a new
+   * XmlNode and set it as our current node. The parent of this new node is
+   * the previous "current" node. We have all the element's attributes in
+   * this event.
+   *
+   * We spawn a stream_event with this node if this is a level-1 element.
+   */
+  void start_element(const XML_Char* name, const XML_Char** attribute);
+  /**
+   * Called when an XML element has been closed. We close the current_node,
+   * set our current_node as the parent of the current_node, and if that was
+   * a level-2 element we spawn a stanza_event with this node.
+   *
+   * And we then delete the stanza (and everything under it, its children,
+   * attribute, etc).
+   */
+  void end_element(const XML_Char* name);
+  /**
+   * Some inner or tail data has been parsed
+   */
+  void char_data(const XML_Char* data, const size_t len);
+  /**
+   * Calls all the stanza_callbacks one by one.
+   */
+  void stanza_event(const Stanza& stanza) const;
+  /**
+   * Calls all the stream_open_callbacks one by one. Note: the passed node is not
+   * closed yet.
+   */
+  void stream_open_event(const XmlNode& node) const;
+  /**
+   * Calls all the stream_close_callbacks one by one.
+   */
+  void stream_close_event(const XmlNode& node) const;
+
+private:
+  /**
+   * Init the XML parser and install the callbacks
+   */
+  void init_xml_parser();
+
+  /**
+   * Expat structure.
+   */
+  XML_Parser parser;
+  /**
+   * The current depth in the XML document
+   */
+  size_t level;
+  /**
+   * The deepest XML node opened but not yet closed (to which we are adding
+   * new children, inner or tail)
+   */
+  XmlNode* current_node;
+  /**
+   * The root node has no parent, so we keep it here: the XmppParser object
+   * is its owner.
+   */
+  std::unique_ptr<XmlNode> root;
+  /**
+   * A list of callbacks to be called on an *_event, receiving the
+   * concerned Stanza/XmlNode.
+   */
+  std::vector<std::function<void(const Stanza&)>> stanza_callbacks;
+  std::vector<std::function<void(const XmlNode&)>> stream_open_callbacks;
+  std::vector<std::function<void(const XmlNode&)>> stream_close_callbacks;
+};
+
+
diff --git a/src/xmpp/xmpp_stanza.cpp b/src/xmpp/xmpp_stanza.cpp
new file mode 100644
index 0000000..ac6ce9b
--- /dev/null
+++ b/src/xmpp/xmpp_stanza.cpp
@@ -0,0 +1,229 @@
+#include <xmpp/xmpp_stanza.hpp>
+
+#include <utils/encoding.hpp>
+#include <utils/split.hpp>
+
+#include <stdexcept>
+#include <iostream>
+#include <sstream>
+
+#include <string.h>
+
+std::string xml_escape(const std::string& data)
+{
+  std::string res;
+  res.reserve(data.size());
+  for (size_t pos = 0; pos != data.size(); ++pos)
+    {
+      switch(data[pos])
+        {
+        case '&':
+          res += "&amp;";
+          break;
+        case '<':
+          res += "&lt;";
+          break;
+        case '>':
+          res += "&gt;";
+          break;
+        case '\"':
+          res += "&quot;";
+          break;
+        case '\'':
+          res += "&apos;";
+          break;
+        default:
+          res += data[pos];
+          break;
+        }
+    }
+  return res;
+}
+
+std::string sanitize(const std::string& data, const std::string& encoding)
+{
+  if (utils::is_valid_utf8(data.data()))
+    return xml_escape(utils::remove_invalid_xml_chars(data));
+  else
+    return xml_escape(utils::remove_invalid_xml_chars(utils::convert_to_utf8(data, encoding.data())));
+}
+
+XmlNode::XmlNode(const std::string& name, XmlNode* parent):
+  parent(parent)
+{
+  // split the namespace and the name
+  auto n = name.rfind(":");
+  if (n == std::string::npos)
+    this->name = name;
+  else
+    {
+      this->name = name.substr(n+1);
+      this->attributes["xmlns"] = name.substr(0, n);
+    }
+}
+
+XmlNode::XmlNode(const std::string& name):
+  XmlNode(name, nullptr)
+{
+}
+
+void XmlNode::delete_all_children()
+{
+  this->children.clear();
+}
+
+void XmlNode::set_attribute(const std::string& name, const std::string& value)
+{
+  this->attributes[name] = value;
+}
+
+void XmlNode::set_tail(const std::string& data)
+{
+  this->tail = data;
+}
+
+void XmlNode::add_to_tail(const std::string& data)
+{
+  this->tail += data;
+}
+
+void XmlNode::set_inner(const std::string& data)
+{
+  this->inner = data;
+}
+
+void XmlNode::add_to_inner(const std::string& data)
+{
+  this->inner += data;
+}
+
+std::string XmlNode::get_inner() const
+{
+  return this->inner;
+}
+
+std::string XmlNode::get_tail() const
+{
+  return this->tail;
+}
+
+const XmlNode* XmlNode::get_child(const std::string& name, const std::string& xmlns) const
+{
+  for (const auto& child: this->children)
+    {
+      if (child->name == name && child->get_tag("xmlns") == xmlns)
+        return child.get();
+    }
+  return nullptr;
+}
+
+std::vector<const XmlNode*> XmlNode::get_children(const std::string& name, const std::string& xmlns) const
+{
+  std::vector<const XmlNode*> res;
+  for (const auto& child: this->children)
+    {
+      if (child->name == name && child->get_tag("xmlns") == xmlns)
+        res.push_back(child.get());
+    }
+  return res;
+}
+
+XmlNode* XmlNode::add_child(std::unique_ptr<XmlNode> child)
+{
+  child->parent = this;
+  auto ret = child.get();
+  this->children.push_back(std::move(child));
+  return ret;
+}
+
+XmlNode* XmlNode::add_child(XmlNode&& child)
+{
+  auto new_node = std::make_unique<XmlNode>(std::move(child));
+  return this->add_child(std::move(new_node));
+}
+
+XmlNode* XmlNode::add_child(const XmlNode& child)
+{
+  auto new_node = std::make_unique<XmlNode>(child);
+  return this->add_child(std::move(new_node));
+}
+
+XmlNode* XmlNode::get_last_child() const
+{
+  return this->children.back().get();
+}
+
+XmlNode* XmlNode::get_parent() const
+{
+  return this->parent;
+}
+
+void XmlNode::set_name(const std::string& name)
+{
+  this->name = name;
+}
+
+void XmlNode::set_name(std::string&& name)
+{
+  this->name = std::move(name);
+}
+
+const std::string XmlNode::get_name() const
+{
+  return this->name;
+}
+
+std::string XmlNode::to_string() const
+{
+  std::ostringstream res;
+  res << "<" << this->name;
+  for (const auto& it: this->attributes)
+    res << " " << it.first << "='" << sanitize(it.second) + "'";
+  if (!this->has_children() && this->inner.empty())
+    res << "/>";
+  else
+    {
+      res << ">" + sanitize(this->inner);
+      for (const auto& child: this->children)
+        res << child->to_string();
+      res << "</" << this->get_name() << ">";
+    }
+  res << sanitize(this->tail);
+  return res.str();
+}
+
+bool XmlNode::has_children() const
+{
+  return !this->children.empty();
+}
+
+const std::string& XmlNode::get_tag(const std::string& name) const
+{
+  try
+    {
+      const auto& value = this->attributes.at(name);
+      return value;
+    }
+  catch (const std::out_of_range& e)
+    {
+      static const std::string def{};
+      return def;
+    }
+}
+
+bool XmlNode::del_tag(const std::string& name)
+{
+  if (this->attributes.erase(name) != 0)
+    return true;
+  return false;
+}
+
+std::string& XmlNode::operator[](const std::string& name)
+{
+  return this->attributes[name];
+}
+
+std::ostream& operator<<(std::ostream& os, const XmlNode& node)
+{
+  return os << node.to_string();
+}
diff --git a/src/xmpp/xmpp_stanza.hpp b/src/xmpp/xmpp_stanza.hpp
new file mode 100644
index 0000000..f4b3948
--- /dev/null
+++ b/src/xmpp/xmpp_stanza.hpp
@@ -0,0 +1,160 @@
+#pragma once
+
+
+#include <map>
+#include <string>
+#include <vector>
+#include <memory>
+
+std::string xml_escape(const std::string& data);
+std::string xml_unescape(const std::string& data);
+std::string sanitize(const std::string& data, const std::string& encoding = "ISO-8859-1");
+
+/**
+ * Represent an XML node. It has
+ * - A parent XML node (in the case of the first-level nodes, the parent is
+     nullptr)
+ * - zero, one or more children XML nodes
+ * - A name
+ * - A map of attributes
+ * - inner data (text inside the node)
+ * - tail data (text just after the node)
+ */
+class XmlNode
+{
+public:
+  explicit XmlNode(const std::string& name, XmlNode* parent);
+  explicit XmlNode(const std::string& name);
+  /**
+   * The copy constructor does not copy the parent attribute. The children
+   * nodes are all copied recursively.
+   */
+  XmlNode(const XmlNode& node):
+    name(node.name),
+    parent(nullptr),
+    attributes(node.attributes),
+    children{},
+    inner(node.inner),
+    tail(node.tail)
+  {
+    for (const auto& child: node.children)
+      this->add_child(std::make_unique<XmlNode>(*child));
+  }
+
+  XmlNode(XmlNode&& node) = default;
+  XmlNode& operator=(const XmlNode&) = delete;
+  XmlNode& operator=(XmlNode&&) = delete;
+
+  ~XmlNode() = default;
+
+  void delete_all_children();
+  void set_attribute(const std::string& name, const std::string& value);
+  /**
+   * Set the content of the tail, that is the text just after this node
+   */
+  void set_tail(const std::string& data);
+  /**
+   * Append the given data to the content of the tail. This exists because
+   * the expat library may provide the complete text of an element in more
+   * than one call
+   */
+  void add_to_tail(const std::string& data);
+  /**
+   * Set the content of the inner, that is the text inside this node.
+   */
+  void set_inner(const std::string& data);
+  /**
+   * Append the given data to the content of the inner. For the reason
+   * described in add_to_tail comment.
+   */
+  void add_to_inner(const std::string& data);
+  /**
+   * Get the content of inner
+   */
+  std::string get_inner() const;
+  /**
+   * Get the content of the tail
+   */
+  std::string get_tail() const;
+  /**
+   * Get a pointer to the first child element with that name and that xml namespace
+   */
+  const XmlNode* get_child(const std::string& name, const std::string& xmlns) const;
+  /**
+   * Get a vector of all the children that have that name and that xml namespace.
+   */
+  std::vector<const XmlNode*> get_children(const std::string& name, const std::string& xmlns) const;
+  /**
+   * Add a node child to this node. Assign this node to the child’s parent.
+   * Returns a pointer to the newly added child.
+   */
+  XmlNode* add_child(std::unique_ptr<XmlNode> child);
+  XmlNode* add_child(XmlNode&& child);
+  XmlNode* add_child(const XmlNode& child);
+  /**
+   * Returns the last of the children. If the node doesn't have any child,
+   * the behaviour is undefined. The user should make sure this is the case
+   * by calling has_children() for example.
+   */
+  XmlNode* get_last_child() const;
+  XmlNode* get_parent() const;
+  void set_name(const std::string& name);
+  void set_name(std::string&& name);
+  const std::string get_name() const;
+  /**
+   * Serialize the stanza into a string
+   */
+  std::string to_string() const;
+  /**
+   * Whether or not this node has at least one child (if not, this is a leaf
+   * node)
+   */
+  bool has_children() const;
+  /**
+   * Gets the value for the given attribute, returns an empty string if the
+   * node as no such attribute.
+   */
+  const std::string& get_tag(const std::string& name) const;
+  /**
+   * Remove the attribute of the node. Does nothing if that attribute is not
+   * present. Returns true if the tag was removed, false if it was absent.
+   */
+  bool del_tag(const std::string& name);
+  /**
+   * Use this to set an attribute's value, like node["id"] = "12";
+   */
+  std::string& operator[](const std::string& name);
+
+private:
+  std::string name;
+  XmlNode* parent;
+  std::map<std::string, std::string> attributes;
+  std::vector<std::unique_ptr<XmlNode>> children;
+  std::string inner;
+  std::string tail;
+};
+
+std::ostream& operator<<(std::ostream& os, const XmlNode& node);
+
+/**
+ * An XMPP stanza is just an XML node of level 2 in the XMPP document (the
+ * level 1 ones are the <stream::stream/>, and the ones above 2 are just the
+ * content of the stanzas)
+ */
+using Stanza = XmlNode;
+
+class XmlSubNode: public XmlNode
+{
+public:
+    XmlSubNode(XmlNode& parent_ref, const std::string& name):
+            XmlNode(name),
+            parent_to_add(parent_ref)
+    {}
+
+    ~XmlSubNode()
+    {
+      this->parent_to_add.add_child(std::move(*this));
+    }
+private:
+    XmlNode& parent_to_add;
+};
\ No newline at end of file