Guard the download against handlers that erase it mid-close

Track a weak_ptr lifetime handle and make erase ignore re-entrant erase.

configure.ac

@@ -1,6 +1,6 @@
 m4_pattern_allow([PKG_CHECK_EXISTS])
 
-AC_INIT([rtorrent],[0.16.22],[sundell.software@gmail.com])
+AC_INIT([rtorrent],[0.16.24],[sundell.software@gmail.com])
 
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_MACRO_DIRS([scripts])
@@ -14,7 +14,7 @@ AX_CXX_COMPILE_STDCXX(20, noext, mandatory)
 
 PKG_PROG_PKG_CONFIG
 
-AC_DEFINE([API_VERSION], [26], [api version])
+AC_DEFINE([API_VERSION], [28], [api version])
 
 RAK_CHECK_CFLAGS
 RAK_CHECK_CXXFLAGS
@@ -49,7 +49,7 @@ fi
 
 PKG_CHECK_MODULES([CPPUNIT], [cppunit],, [no_cppunit="yes"])
 PKG_CHECK_MODULES([ZLIB], [zlib])
-PKG_CHECK_MODULES([DEPENDENCIES], [libtorrent >= 0.16.22])
+PKG_CHECK_MODULES([DEPENDENCIES], [libtorrent >= 0.16.24])
 
 AC_LANG_PUSH(C++)
 TORRENT_WITH_XMLRPC_C

src/command_download.cc

@@ -402,13 +402,21 @@ p_multicall(core::Download* download, const torrent::Object::list_type& args) {
   auto  resultRaw = torrent::Object::create_list();
   auto& result    = resultRaw.as_list();
 
-  for (const auto& connection : *download->connection_list()) {
+  auto*      connection_list = download->connection_list();
+  const auto change_counter  = connection_list->change_counter();
+
+  for (const auto& connection : *connection_list) {
     torrent::Object::list_type& row = result.insert(result.end(), torrent::Object::create_list())->as_list();
 
     for (auto cItr = ++args.begin(); cItr != args.end(); cItr++) {
       const std::string& cmd = cItr->as_string();
 
       row.push_back(rpc::parse_command(rpc::make_target(connection), cmd.c_str(), cmd.c_str() + cmd.size()).first);
+
+      // Erasing a peer frees it and swaps the last element into its place, so
+      // neither this peer nor the iteration survives a change to the list.
+      if (connection_list->change_counter() != change_counter)
+        throw torrent::input_error("Command changed the connection list during p.multicall.");
     }
   }
 
@@ -431,6 +439,9 @@ p_call_target(const torrent::Object::list_type& args) {
   const std::string& peer_id = itr++->as_string();
   const std::string& command_key = itr++->as_string();
 
+  if (download == nullptr)
+    throw torrent::input_error("invalid parameters: info-hash not found");
+
   torrent::HashString hash;
 
   if (peer_id.size() != 40)

src/command_dynamic.cc

@@ -157,7 +157,7 @@ system_method_insert_object(const torrent::Object::list_type& args, int flags) {
     torrent::Object             valueList     = torrent::Object::create_list();
     torrent::Object::list_type& valueListType = valueList.as_list();
 
-    if ((itrArgs)->is_list())
+    if (itrArgs != args.end() && (itrArgs)->is_list())
       valueListType = (itrArgs)->as_list();
 
     control->object_storage()->insert_str(raw_key, valueList, flags);

src/command_ip.cc

@@ -319,6 +319,11 @@ apply_ipv4_filter_load(const torrent::Object::list_type& args) {
       ipv4_filter_parse(buffer, value);
     }
 
+    if (file.fail() && !file.eof()) {
+      lineNumber++;
+      throw torrent::input_error("Exceeded max line length.");
+    }
+
   } catch (torrent::input_error& e) {
     snprintf(buffer, 2048, "Error in ip filter file: %s:%u: %s", filename.c_str(), lineNumber, e.what());
 
@@ -339,8 +344,8 @@ apply_ipv4_filter_dump() {
   torrent::Object raw_result = torrent::Object::create_list();
   torrent::Object::list_type& result = raw_result.as_list();
 
-  torrent::ipv4_table::range_map_type range_map = torrent::PeerList::ipv4_filter()->range_map;
-  torrent::ipv4_table::range_map_type::iterator iter = range_map.begin();
+  const torrent::ipv4_table::range_map_type& range_map = torrent::PeerList::ipv4_filter()->range_map;
+  torrent::ipv4_table::range_map_type::const_iterator iter = range_map.begin();
 
   while(iter != range_map.end()) {
     char buffer[64];

src/command_logging.cc

@@ -122,7 +122,10 @@ log_vmmap_dump(const std::string& str) {
     fprintf(log_file, "%8p-%8p [%5llxk]\n", all_mapping.ptr, (char*)all_mapping.ptr + all_mapping.length, (long long unsigned int)(all_mapping.length / 1024));
   }
 
-  fclose(log_file);
+  // The buffered output only reaches the kernel here.
+  if (fclose(log_file) != 0)
+    throw torrent::input_error("Could not write log file: " + str);
+
   return torrent::Object();
 }
 

src/command_network.cc

@@ -374,25 +374,31 @@ initialize_command_network() {
   CMD_ANY_STRING  ("network.tos.set",                        [](auto, auto& str)             { return apply_tos(str); });
 
   CMD_ANY         ("network.bind_address",                   [nw_config](auto, auto)         { return nw_config->bind_address_best_match_str(); });
-  CMD_ANY_STRING_V("network.bind_address.set",               [nw_config](auto, auto& str)    { return nw_config->set_bind_address_str(str); });
+  CMD_ANY_STRING_V("network.bind_address.set",               [nw_config](auto, auto& str)    { return nw_config->set_bind_address(str); });
   CMD_ANY         ("network.bind_address.ipv4",              [nw_config](auto, auto)         { return nw_config->bind_inet_address_str(); });
-  CMD_ANY_STRING_V("network.bind_address.ipv4.set",          [nw_config](auto, auto& str)    { return nw_config->set_bind_inet_address_str(str); });
+  CMD_ANY_STRING_V("network.bind_address.ipv4.set",          [nw_config](auto, auto& str)    { return nw_config->set_bind_inet_address(str); });
   CMD_ANY         ("network.bind_address.ipv6",              [nw_config](auto, auto)         { return nw_config->bind_inet6_address_str(); });
-  CMD_ANY_STRING_V("network.bind_address.ipv6.set",          [nw_config](auto, auto& str)    { return nw_config->set_bind_inet6_address_str(str); });
+  CMD_ANY_STRING_V("network.bind_address.ipv6.set",          [nw_config](auto, auto& str)    { return nw_config->set_bind_inet6_address(str); });
+
+  CMD_ANY_STRING_V("network.bind_device.set",                [nw_config](auto, auto& str)    { return nw_config->set_bind_device_name(str); });
+  CMD_ANY         ("network.bind_device.ipv4",               [nw_config](auto, auto)         { return nw_config->bind_inet_device_name(); });
+  CMD_ANY_STRING_V("network.bind_device.ipv4.set",           [nw_config](auto, auto& str)    { return nw_config->set_bind_inet_device_name(str); });
+  CMD_ANY         ("network.bind_device.ipv6",               [nw_config](auto, auto)         { return nw_config->bind_inet6_device_name(); });
+  CMD_ANY_STRING_V("network.bind_device.ipv6.set",           [nw_config](auto, auto& str)    { return nw_config->set_bind_inet6_device_name(str); });
 
   CMD_ANY         ("network.local_address",                  [nw_config](auto, auto)         { return nw_config->local_address_best_match_str(); });
-  CMD_ANY_STRING_V("network.local_address.set",              [nw_config](auto, auto& str)    { return nw_config->set_local_address_str(str); });
+  CMD_ANY_STRING_V("network.local_address.set",              [nw_config](auto, auto& str)    { return nw_config->set_local_address(str); });
   CMD_ANY         ("network.local_address.ipv4",             [nw_config](auto, auto)         { return nw_config->local_inet_address_str(); });
-  CMD_ANY_STRING_V("network.local_address.ipv4.set",         [nw_config](auto, auto& str)    { return nw_config->set_local_inet_address_str(str); });
+  CMD_ANY_STRING_V("network.local_address.ipv4.set",         [nw_config](auto, auto& str)    { return nw_config->set_local_inet_address(str); });
   CMD_ANY         ("network.local_address.ipv6",             [nw_config](auto, auto)         { return nw_config->local_inet6_address_str(); });
-  CMD_ANY_STRING_V("network.local_address.ipv6.set",         [nw_config](auto, auto& str)    { return nw_config->set_local_inet6_address_str(str); });
+  CMD_ANY_STRING_V("network.local_address.ipv6.set",         [nw_config](auto, auto& str)    { return nw_config->set_local_inet6_address(str); });
 
   CMD_ANY         ("network.local_port",                     [nw_config](auto, auto)         { return nw_config->local_port_best_match(); });
-  CMD_ANY_VALUE_V ("network.local_port.set",                 [nw_config](auto, auto& value) { return nw_config->set_local_port(checked_local_port_value(value, "local")); });
+  CMD_ANY_VALUE_V ("network.local_port.set",                 [nw_config](auto, auto& value)  { return nw_config->set_local_port(checked_local_port_value(value, "local")); });
   CMD_ANY         ("network.local_port.ipv4",                [nw_config](auto, auto)         { return nw_config->local_inet_port(); });
-  CMD_ANY_VALUE_V ("network.local_port.ipv4.set",            [nw_config](auto, auto& value) { return nw_config->set_local_inet_port(checked_local_port_value(value, "local ipv4")); });
+  CMD_ANY_VALUE_V ("network.local_port.ipv4.set",            [nw_config](auto, auto& value)  { return nw_config->set_local_inet_port(checked_local_port_value(value, "local ipv4")); });
   CMD_ANY         ("network.local_port.ipv6",                [nw_config](auto, auto)         { return nw_config->local_inet6_port(); });
-  CMD_ANY_VALUE_V ("network.local_port.ipv6.set",            [nw_config](auto, auto& value) { return nw_config->set_local_inet6_port(checked_local_port_value(value, "local ipv6")); });
+  CMD_ANY_VALUE_V ("network.local_port.ipv6.set",            [nw_config](auto, auto& value)  { return nw_config->set_local_inet6_port(checked_local_port_value(value, "local ipv6")); });
 
   CMD_ANY         ("network.proxy.global",                   [](auto, auto)                  { return torrent::runtime::proxy_manager()->proxy_url(); });
   CMD_ANY_STRING_V("network.proxy.global.set",               [](auto, auto& str)             { return torrent::runtime::proxy_manager()->set_proxy_url(str); });

src/command_throttle.cc

@@ -1,10 +1,9 @@
 #include "config.h"
 
-#include <cstdio>
+#include <limits>
 #include <torrent/throttle.h>
 #include <torrent/rate.h>
 #include <torrent/download/resource_manager.h>
-#include <torrent/net/socket_address.h>
 
 #include "core/manager.h"
 #include "ui/root.h"
@@ -15,59 +14,6 @@
 #include "control.h"
 #include "command_helpers.h"
 
-std::pair<uint32_t, uint32_t>
-parse_address_range(const torrent::Object::list_type& args, torrent::Object::list_type::const_iterator itr) {
-  unsigned int prefixWidth, ret;
-  char dummy;
-  char host[1024];
-  torrent::sa_unique_ptr sa;
-
-  ret = std::sscanf(itr->as_string().c_str(), "%1023[^/]/%d%c", host, &prefixWidth, &dummy);
-
-  if (ret < 1)
-    throw torrent::input_error("Invalid address/prefix.");
-
-  try {
-    sa = torrent::sa_copy(torrent::sa_lookup_address(host, AF_INET).get());
-
-  } catch (torrent::input_error& e) {
-    throw torrent::input_error("Could not resolve host: " + std::string(e.what()));
-  }
-
-  uint32_t begin, end;
-
-  auto sa_addr = htonl(reinterpret_cast<sockaddr_in*>(sa.get())->sin_addr.s_addr);
-
-  begin = end = sa_addr;
-
-  if (ret == 2) {
-    if (++itr != args.end())
-      throw torrent::input_error("Cannot specify both network and range end.");
-
-    uint32_t netmask = std::numeric_limits<uint32_t>::max() << (32 - prefixWidth);
-
-    if (prefixWidth >= 32 || sa_addr & ~netmask)
-      throw torrent::input_error("Invalid address/prefix.");
-
-    end = sa_addr | ~netmask;
-
-  } else if (++itr != args.end()) {
-    try {
-      sa = torrent::sa_copy(torrent::sa_lookup_address(itr->as_string(), AF_INET).get());
-
-    } catch (torrent::input_error& e) {
-      throw torrent::input_error("Could not resolve host: " + std::string(e.what()));
-    }
-
-    sa_addr = htonl(reinterpret_cast<sockaddr_in*>(sa.get())->sin_addr.s_addr);
-    end = sa_addr;
-  }
-
-  // convert to [begin, end) making sure the end doesn't overflow
-  // (this precludes 255.255.255.255 from ever matching, but that's not a real IP anyway)
-  return std::make_pair((uint32_t)begin, (uint32_t)std::max(end, end + 1));
-}
-
 torrent::Object
 apply_throttle(const torrent::Object::list_type& args, bool up) {
   auto arg_itr = args.begin();
@@ -83,11 +29,16 @@ apply_throttle(const torrent::Object::list_type& args, bool up) {
     throw torrent::input_error("Missing throttle rate for '" + name + "'.");
 
   int64_t rate;
-  rpc::parse_whole_value_nothrow(arg_itr->as_string().c_str(), &rate);
+
+  if (!rpc::parse_whole_value_nothrow(arg_itr->as_string().c_str(), &rate))
+    throw torrent::input_error("Invalid throttle rate for '" + name + "'.");
 
   if (rate < 0)
     throw torrent::input_error("Throttle rate must be non-negative.");
 
+  if (rate > (std::numeric_limits<int64_t>::max() >> 10))
+    throw torrent::input_error("Throttle rate is too large.");
+
   auto itr = control->core()->throttles().find(name);
 
   if (itr == control->core()->throttles().end())
@@ -138,6 +89,24 @@ throttle_update(const char* variable, int64_t value) {
   return torrent::Object();
 }
 
+static unsigned int
+throttle_rate_to_kb(int64_t rate) {
+  if (rate < 0 || rate > std::numeric_limits<unsigned int>::max() - 1)
+    throw torrent::input_error("Throttle rate must be between 0 and 4294967294.");
+
+  return static_cast<unsigned int>(rate >> 10);
+}
+
+static void
+set_up_throttle_i64(ui::Root* root, int64_t rate) {
+  root->set_up_throttle(throttle_rate_to_kb(rate));
+}
+
+static void
+set_down_throttle_i64(ui::Root* root, int64_t rate) {
+  root->set_down_throttle(throttle_rate_to_kb(rate));
+}
+
 void
 initialize_command_throttle() {
   CMD2_ANY         ("throttle.unchoked_uploads",       std::bind(&torrent::ResourceManager::currently_upload_unchoked, torrent::resource_manager()));
@@ -174,13 +143,13 @@ initialize_command_throttle() {
   CMD2_ANY         ("throttle.global_up.rate",              std::bind(&torrent::Rate::rate, torrent::up_rate()));
   CMD2_ANY         ("throttle.global_up.total",             std::bind(&torrent::Rate::total, torrent::up_rate()));
   CMD2_ANY         ("throttle.global_up.max_rate",          std::bind(&torrent::Throttle::max_rate, torrent::up_throttle_global()));
-  CMD2_ANY_VALUE_V ("throttle.global_up.max_rate.set",      std::bind(&ui::Root::set_up_throttle_i64, control->ui(), std::placeholders::_2));
-  CMD2_ANY_VALUE_KB("throttle.global_up.max_rate.set_kb",   std::bind(&ui::Root::set_up_throttle_i64, control->ui(), std::placeholders::_2));
+  CMD2_ANY_VALUE_V ("throttle.global_up.max_rate.set",      std::bind(&set_up_throttle_i64, control->ui(), std::placeholders::_2));
+  CMD2_ANY_VALUE_KB("throttle.global_up.max_rate.set_kb",   std::bind(&set_up_throttle_i64, control->ui(), std::placeholders::_2));
   CMD2_ANY         ("throttle.global_down.rate",            std::bind(&torrent::Rate::rate, torrent::down_rate()));
   CMD2_ANY         ("throttle.global_down.total",           std::bind(&torrent::Rate::total, torrent::down_rate()));
   CMD2_ANY         ("throttle.global_down.max_rate",        std::bind(&torrent::Throttle::max_rate, torrent::down_throttle_global()));
-  CMD2_ANY_VALUE_V ("throttle.global_down.max_rate.set",    std::bind(&ui::Root::set_down_throttle_i64, control->ui(), std::placeholders::_2));
-  CMD2_ANY_VALUE_KB("throttle.global_down.max_rate.set_kb", std::bind(&ui::Root::set_down_throttle_i64, control->ui(), std::placeholders::_2));
+  CMD2_ANY_VALUE_V ("throttle.global_down.max_rate.set",    std::bind(&set_down_throttle_i64, control->ui(), std::placeholders::_2));
+  CMD2_ANY_VALUE_KB("throttle.global_down.max_rate.set_kb", std::bind(&set_down_throttle_i64, control->ui(), std::placeholders::_2));
 
   // Temporary names, need to change this to accept real rates rather
   // than kB.

src/command_ui.cc

@@ -2,6 +2,7 @@
 
 #include <sys/types.h>
 
+#include <cerrno>
 #include <ctime>
 #include <limits>
 #include <regex>
@@ -126,11 +127,20 @@ apply_value([[maybe_unused]] rpc::target_type target, const torrent::Object::lis
   if (args.front().is_value()) {
     val = args.front().as_value();
   } else {
-    int base = args.size() > 1 ? args.back().is_value() ?
-               args.back().as_value() : strtol(args.back().as_string().c_str(), NULL, 10) : 10;
+    int64_t base = args.size() > 1 ? args.back().is_value() ?
+                   args.back().as_value() : strtoll(args.back().as_string().c_str(), NULL, 10) : 10;
+
+    if (base != 0 && (base < 2 || base > 36))
+      throw torrent::input_error("'value' base must be 0 or between 2 and 36!");
+
     char* endptr = 0;
+    errno = 0;
 
     val = strtoll(args.front().as_string().c_str(), &endptr, base);
+
+    if (errno == ERANGE)
+      throw torrent::input_error("Number out of range: " + args.front().as_string());
+
     while (*endptr == ' ' || *endptr == '\n') ++endptr;
     if (*endptr)
       throw torrent::input_error("Junk at end of number: " + args.front().as_string());

src/core/dht_manager.cc

@@ -4,6 +4,7 @@
 
 #include <fstream>
 #include <sstream>
+#include <torrent/exceptions.h>
 #include <torrent/object.h>
 #include <torrent/object_stream.h>
 #include <torrent/rate.h>
@@ -62,7 +63,14 @@ DhtManager::load_dht_cache() {
     LT_LOG("could not open cache file (path:%s)", cache_filename.c_str());
   }
 
-  torrent::runtime::network_manager()->dht_controller()->initialize(cache);
+  try {
+    torrent::runtime::network_manager()->dht_controller()->initialize(cache);
+
+  } catch (const torrent::base_error& e) {
+    LT_LOG_ERROR("cache file rejected, discarding (path:%s errmsg:%s)", cache_filename.c_str(), e.what());
+
+    torrent::runtime::network_manager()->dht_controller()->initialize(torrent::Object::create_map());
+  }
 
   if (m_start == dht_on)
     start_dht();
@@ -132,11 +140,12 @@ DhtManager::save_dht_cache() {
   torrent::Object cache = torrent::Object::create_map();
   cache_file << *torrent::runtime::network_manager()->dht_controller()->store_cache(&cache);
 
+  // The data only reaches the kernel here, so this is where a full disk is seen.
+  cache_file.close();
+
   if (!cache_file.good())
     return;
 
-  cache_file.close();
-
   ::rename(filename_tmp.c_str(), filename.c_str());
 }
 

src/core/download.h

@@ -51,6 +51,14 @@ public:
   bool                is_hash_checking() const                 { return m_download.is_hash_checking(); }
 
   bool                is_hash_failed() const                   { return m_hashFailed; }
+
+  // Expires once the download is erased, even if other owners keep the
+  // object alive. Take it before triggering events that may erase.
+  std::weak_ptr<void> lifetime() const                         { return m_lifetime; }
+  void                release_lifetime()                       { m_lifetime.reset(); }
+
+  bool                is_erasing() const                       { return m_erasing; }
+  void                set_erasing()                            { m_erasing = true; }
   void                set_hash_failed(bool v)                  { m_hashFailed = v; }
 
   download_type*       download()                              { return &m_download; }
@@ -103,6 +111,8 @@ private:
   // Store the FileList instance so we can use slots etc on it.
   download_type       m_download;
   bool                m_hashFailed{};
+  bool                m_erasing{};
+  std::shared_ptr<void> m_lifetime{std::make_shared<char>()};
   std::string         m_message;
   uint32_t            m_resumeFlags{default_resume_flags};
   unsigned int        m_group{};

src/core/download_list.cc

@@ -194,6 +194,12 @@ DownloadList::erase(iterator itr) {
   if (itr == end())
     throw torrent::internal_error("DownloadList::erase(...) could not find download.");
 
+  // An event handler below may erase the same download again.
+  if ((*itr)->is_erasing())
+    return std::next(itr);
+
+  (*itr)->set_erasing();
+
   lt_log_print_info(torrent::LOG_TORRENT_INFO, (*itr)->info(), "download_list", "Erasing download.");
 
   // Makes sure close doesn't restart hashing of this download.
@@ -207,6 +213,7 @@ DownloadList::erase(iterator itr) {
   for (auto v : *control->view_manager())
     v->erase(itr->get());
 
+  (*itr)->release_lifetime();
   torrent::download_remove(*(*itr)->download());
 
   return base_type::erase(itr);
@@ -275,6 +282,7 @@ void
 DownloadList::close_directly(Download* download) {
   lt_log_print_info(torrent::LOG_TORRENT_INFO, download->info(), "download_list", "Closing download directly.");
 
+  auto lifetime   = download->lifetime();
   bool was_active = download->download()->info()->is_active();
   bool was_open   = download->download()->info()->is_open();
 
@@ -283,11 +291,19 @@ DownloadList::close_directly(Download* download) {
 
   if (was_active) {
     DL_TRIGGER_EVENT(download, "event.download.paused");
+
+    if (lifetime.expired())
+      return;
+
     update_paused_state(download);
   }
 
   if (was_open) {
     DL_TRIGGER_EVENT(download, "event.download.hash_removed");
+
+    if (lifetime.expired())
+      return;
+
     DL_TRIGGER_EVENT(download, "event.download.closed");
   }
 }
@@ -301,7 +317,7 @@ DownloadList::set_state_stopped(Download* download) {
 void
 DownloadList::update_paused_state(Download* download) {
   rpc::call_command("d.state_changed.set", torrent::this_thread::cached_seconds().count(), rpc::make_target(download));
-  rpc::call_command("d.state_counter.set", rpc::call_command_value("d.state_counter", rpc::make_target(download)), rpc::make_target(download));
+  rpc::call_command("d.state_counter.set", rpc::call_command_value("d.state_counter", rpc::make_target(download)) + 1, rpc::make_target(download));
 
   // If initial seeding is complete, don't try it again when restarting.
   if (download->is_done() &&
@@ -330,8 +346,13 @@ DownloadList::close_throw(Download* download) {
   // When pause gets called it will clear the initial hash check state
   // and set hash failed. This should ensure hashing doesn't restart
   // until resume gets called.
+  auto lifetime = download->lifetime();
+
   pause(download);
 
+  if (lifetime.expired())
+    return;
+
   // Check for is_open after pause due to hashing.
   if (!download->is_open())
     return;
@@ -351,6 +372,10 @@ DownloadList::close_throw(Download* download) {
     throw torrent::internal_error("DownloadList::close_throw(...) called but we're going into a hashing loop.");
 
   DL_TRIGGER_EVENT(download, "event.download.hash_removed");
+
+  if (lifetime.expired())
+    return;
+
   DL_TRIGGER_EVENT(download, "event.download.closed");
 }
 
@@ -457,6 +482,8 @@ DownloadList::pause(Download* download, int flags) {
 
   lt_log_print_info(torrent::LOG_TORRENT_INFO, download->info(), "download_list", "Pausing download: flags:%0x.", flags);
 
+  auto lifetime = download->lifetime();
+
   try {
 
     download->set_resume_flags(Download::default_resume_flags);
@@ -470,6 +497,9 @@ DownloadList::pause(Download* download, int flags) {
       rpc::call_command_set_value("d.hashing.set", Download::variable_hashing_stopped, rpc::make_target(download));
 
       DL_TRIGGER_EVENT(download, "event.download.hash_removed");
+
+      if (lifetime.expired())
+        return;
     }
 
     if (!download->download()->info()->is_active())
@@ -483,6 +513,9 @@ DownloadList::pause(Download* download, int flags) {
     // view.
     DL_TRIGGER_EVENT(download, "event.download.paused");
 
+    if (lifetime.expired())
+      return;
+
     update_paused_state(download);
 
     // Save the state after all the slots, etc have been called so we
@@ -563,9 +596,15 @@ DownloadList::hash_done(Download* download) {
     rpc::call_command("d.complete.set", (int64_t)download->is_done(), rpc::make_target(download));
     torrent::resume_save_progress(*download->download(), download->download()->bencode()->get_key("libtorrent_resume"));
 
-    if (rpc::call_command_value("d.state", rpc::make_target(download)) == 1)
+    if (rpc::call_command_value("d.state", rpc::make_target(download)) == 1) {
+      auto lifetime = download->lifetime();
+
       resume(download, download->resume_flags());
 
+      if (lifetime.expired())
+        return;
+    }
+
     break;
 
   case Download::variable_hashing_last:
@@ -602,11 +641,24 @@ DownloadList::hash_queue(Download* download, int type) {
 
   // HACK
   if (download->is_open()) {
+    auto lifetime = download->lifetime();
+
     pause(download, torrent::Download::stop_skip_tracker);
+
+    if (lifetime.expired())
+      return;
+
     download->download()->close();
 
     DL_TRIGGER_EVENT(download, "event.download.hash_removed");
+
+    if (lifetime.expired())
+      return;
+
     DL_TRIGGER_EVENT(download, "event.download.closed");
+
+    if (lifetime.expired())
+      return;
   }
 
   torrent::resume_clear_progress(*download->download(), download->download()->bencode()->get_key("libtorrent_resume"));
@@ -682,12 +734,12 @@ DownloadList::confirm_finished(Download* download) {
   // up/downloaded baseline.
   download->download()->send_completed();
 
-  // Save the hash in case the finished event erases it.
-  torrent::HashString infohash = download->info()->hash();
+  // The finished event may erase the download.
+  auto lifetime = download->lifetime();
 
   DL_TRIGGER_EVENT(download, "event.download.finished");
 
-  if (find(infohash) == end())
+  if (lifetime.expired())
     return;
 
 //   if (download->resume_flags() != Download::default_resume_flags)
@@ -726,11 +778,10 @@ DownloadList::process_meta_download(Download* download) {
     return;
   }
 
-  torrent::Object* bencode = new torrent::Object(torrent::Object::create_map());
+  auto bencode = std::make_unique<torrent::Object>(torrent::Object::create_map());
   file >> bencode->insert_key("info", torrent::Object());
 
   if (file.fail()) {
-    delete bencode;
     lt_log_print(torrent::LOG_TORRENT_ERROR, "Could not create download, the input is not a valid torrent.");
     return;
   }
@@ -746,7 +797,7 @@ DownloadList::process_meta_download(Download* download) {
 
   erase_ptr(download);
 
-  control->core()->try_create_download_from_meta_download(bencode, metafile);
+  control->core()->try_create_download_from_meta_download(std::move(bencode), metafile);
 }
 
 }

src/core/manager.cc

@@ -195,14 +195,14 @@ Manager::try_create_download(const std::string& uri, int flags, const command_li
     return;
 
   // Adding download.
-  DownloadFactory* f = new DownloadFactory(this);
+  auto f = std::make_unique<DownloadFactory>(this);
 
   f->variables()["tied_to_file"] = (int64_t)(bool)(flags & create_tied);
   f->commands().insert(f->commands().end(), commands.begin(), commands.end());
 
   f->set_start(flags & create_start);
   f->set_print_log(!(flags & create_quiet));
-  f->slot_finished([f]() { delete f; });
+  f->slot_finished([factory = f.get()]() { delete factory; });
 
   if (is_data_uri(uri)) {
     // Allow the use of data URIs, primarily for JSON-RPC which
@@ -216,10 +216,13 @@ Manager::try_create_download(const std::string& uri, int flags, const command_li
   }
 
   f->commit();
+
+  // From here the finished slot deletes it.
+  f.release();
 }
 
 void
-Manager::try_create_download_from_meta_download(torrent::Object* bencode, const std::string& metafile) {
+Manager::try_create_download_from_meta_download(std::unique_ptr<torrent::Object> bencode, const std::string& metafile) {
   DownloadFactory* f = new DownloadFactory(this);
 
   f->variables()["tied_to_file"] = (int64_t)true;

src/core/manager.h

@@ -76,7 +76,7 @@ public:
   // Temporary, find a better place for this.
   void                try_create_download(const std::string& uri, int flags, const command_list_type& commands);
   void                try_create_download_expand(const std::string& uri, int flags, command_list_type commands = command_list_type());
-  void                try_create_download_from_meta_download(torrent::Object* bencode, const std::string& metafile);
+  void                try_create_download_from_meta_download(std::unique_ptr<torrent::Object> bencode, const std::string& metafile);
 
 private:
   void                create_http(const std::string& uri);

src/core/view.cc

@@ -216,7 +216,7 @@ View::set_not_visible(Download* download) {
 
 void
 View::next_focus(unsigned int i) {
-  if (empty())
+  if (empty_visible())
     return;
 
   // If at the boundary, roll over
@@ -239,7 +239,7 @@ View::next_focus(unsigned int i) {
 
 void
 View::prev_focus(unsigned int i) {
-  if (empty())
+  if (empty_visible())
     return;
 
   // If at the boundary, roll over
@@ -301,7 +301,7 @@ View::filter() {
     std::for_each(changed.begin(), splitChanged, [this](const auto& d) { rpc::call_object_d_nothrow(m_event_removed, d.get()); });
 
   if (!m_event_added.is_empty())
-    std::for_each(changed.begin(), splitChanged, [this](const auto& d) { rpc::call_object_d_nothrow(m_event_added, d.get()); });
+    std::for_each(splitChanged, changed.end(), [this](const auto& d) { rpc::call_object_d_nothrow(m_event_added, d.get()); });
 
   emit_changed();
 }

src/display/window_file_list.cc

@@ -25,7 +25,10 @@ WindowFileList::WindowFileList(const ui::ElementFileList* element) :
 // Convert std::string to std::wstring of given width (in screen positions),
 // taking into account that some characters may be occupying two screen positions.
 std::wstring
-wstring_width(const std::string& i_str, [[maybe_unused]] int width) {
+wstring_width(const std::string& i_str, int width) {
+  if (width < 0)
+    width = 0;
+
   std::wstring result(width + 1, L' ');
   size_t length = std::mbstowcs(result.data(), i_str.c_str(), width);
 

src/display/window_log.cc

@@ -1,6 +1,8 @@
 #include "config.h"
 
 #include <ctime>
+#include <mutex>
+#include <vector>
 #include <torrent/torrent.h>
 #include <torrent/system/callbacks.h>
 #include <torrent/system/thread.h>
@@ -41,13 +43,20 @@ WindowLog::redraw() {
 
   int pos = m_canvas->height();
 
-  for (iterator itr = m_log->end(), last = find_older(); itr != last && pos > 0; --pos) {
-    itr--;
+  std::vector<torrent::log_entry> entries;
 
+  {
+    std::lock_guard<torrent::log_buffer> guard(*m_log);
+
+    for (iterator itr = m_log->end(), last = find_older(); itr != last && entries.size() < static_cast<size_t>(pos); )
+      entries.push_back(*--itr);
+  }
+
+  for (const auto& entry : entries) {
     char buffer[16];
-    print_hhmmss_local(buffer, buffer + 16, static_cast<time_t>(itr->timestamp));
+    print_hhmmss_local(buffer, buffer + 16, static_cast<time_t>(entry.timestamp));
 
-    m_canvas->print(0, pos - 1, "(%s) %s", buffer, itr->message.c_str());
+    m_canvas->print(0, --pos, "(%s) %s", buffer, entry.message.c_str());
   }
 }
 
@@ -60,8 +69,13 @@ WindowLog::receive_update() {
   if (!is_active())
     return;
 
-  auto itr    = find_older();
-  auto height = std::min(std::distance(itr, (iterator)m_log->end()), (std::iterator_traits<iterator>::difference_type)10);
+  std::iterator_traits<iterator>::difference_type height;
+
+  {
+    std::lock_guard<torrent::log_buffer> guard(*m_log);
+
+    height = std::min(std::distance(find_older(), (iterator)m_log->end()), (std::iterator_traits<iterator>::difference_type)10);
+  }
 
   if (height != m_max_height) {
     m_min_height = height != 0 ? 1 : 0;

src/display/window_log_complete.cc

@@ -1,6 +1,8 @@
 #include "config.h"
 
 #include <ctime>
+#include <mutex>
+#include <vector>
 
 #include "canvas.h"
 #include "utils.h"
@@ -29,24 +31,34 @@ WindowLogComplete::redraw() {
 
   int pos = m_canvas->height();
 
-  for (iterator itr = m_log->end(), last = m_log->begin(); itr != last && pos > 0; ) {
-    itr--;
+  std::vector<torrent::log_entry> entries;
+
+  {
+    std::lock_guard<torrent::log_buffer> guard(*m_log);
+
+    for (iterator itr = m_log->end(), last = m_log->begin(); itr != last && entries.size() < static_cast<size_t>(pos); )
+      entries.push_back(*--itr);
+  }
+
+  for (const auto& entry : entries) {
+    if (pos <= 0)
+      break;
 
     char buffer[16];
 
     // Use an arbitrary min width of 60 for allowing multiple
     // lines. This should ensure we don't mess up the display when the
     // screen is shrunk too much.
-    unsigned int timeWidth = 3 + print_hhmmss_local(buffer, buffer + 16, static_cast<time_t>(itr->timestamp)) - buffer;
+    unsigned int timeWidth = 3 + print_hhmmss_local(buffer, buffer + 16, static_cast<time_t>(entry.timestamp)) - buffer;
 
     unsigned int logWidth  = m_canvas->width() > 60 ? (m_canvas->width() - timeWidth) : (60 - timeWidth);
-    unsigned int logHeight = (itr->message.size() + logWidth - 1) / logWidth;
+    unsigned int logHeight = (entry.message.size() + logWidth - 1) / logWidth;
 
     for (unsigned int j = logHeight; j > 0 && pos > 0; --j, --pos)
       if (j == 1)
-        m_canvas->print(0, pos - 1, "(%s) %s", buffer, itr->message.substr(0, m_canvas->width() - timeWidth).c_str());
+        m_canvas->print(0, pos - 1, "(%s) %s", buffer, entry.message.substr(0, m_canvas->width() - timeWidth).c_str());
       else
-        m_canvas->print(timeWidth, pos - 1, "%s", itr->message.substr(logWidth * (j - 1), m_canvas->width() - timeWidth).c_str());
+        m_canvas->print(timeWidth, pos - 1, "%s", entry.message.substr(logWidth * (j - 1), m_canvas->width() - timeWidth).c_str());
   }
 }
 

src/main.cc

@@ -550,8 +550,6 @@ handle_sigbus(int signum, siginfo_t* sa, [[maybe_unused]] void* ptr) {
 #else
   output << "Stack dump not enabled." << std::endl;
 #endif
-  output << std::endl << "Error: " << std::strerror(sa->si_errno) << std::endl;
-
   const char* signal_reason;
 
   switch (sa->si_code) {

src/rpc/command_scheduler.cc

@@ -61,14 +61,20 @@ CommandScheduler::call_item(value_type item) {
   // Remove the item before calling the command if it should be
   // removed.
 
+  std::string key = item->key();
+
   try {
     rpc::call_object(item->command());
 
   } catch (torrent::input_error& e) {
     if (m_slotErrorMessage)
-      m_slotErrorMessage("Scheduled command failed: " + item->key() + ": " + e.what());
+      m_slotErrorMessage("Scheduled command failed: " + key + ": " + e.what());
   }
 
+  // The command is allowed to erase or replace this item, which deletes it.
+  if (std::find(begin(), end(), item) == end())
+    return;
+
   // Still schedule if we caught a torrrent::input_error?
   auto next = item->next_time_scheduled();
 

src/rpc/jsonrpc.cc

@@ -2,8 +2,10 @@
 
 #include "rpc/jsonrpc.h"
 
+#include <cstddef>
 #include <cstdint>
 #include <string>
+#include <utility>
 #include <torrent/common.h>
 #include <torrent/torrent.h>
 #include <torrent/utils/string_manip.h>
@@ -13,6 +15,7 @@
 #include "rpc/command_map.h"
 #include "rpc/nlohmann/json.h"
 #include "rpc/parse_commands.h"
+#include "rpc/scgi_task.h"
 #include "torrent/exceptions.h"
 #include "torrent/object.h"
 #include "utils/functional.h"
@@ -222,13 +225,49 @@ handle_notification(const json& request) noexcept {
   }
 }
 
+namespace {
+
+using json_input_adapter = decltype(nlohmann::detail::input_adapter(std::declval<const char*>(), std::declval<const char*>()));
+using json_dom_parser    = nlohmann::detail::json_sax_dom_parser<json, json_input_adapter>;
+
+class json_depth_limited_parser : public json_dom_parser {
+public:
+  explicit json_depth_limited_parser(json& root) : json_dom_parser(root) {}
+
+  bool start_object(std::size_t length) { return enter() && json_dom_parser::start_object(length); }
+  bool start_array(std::size_t length) { return enter() && json_dom_parser::start_array(length); }
+
+  bool end_object() { m_depth--; return json_dom_parser::end_object(); }
+  bool end_array() { m_depth--; return json_dom_parser::end_array(); }
+
+private:
+  bool enter() { return ++m_depth <= max_json_depth; }
+
+  uint32_t m_depth{0};
+};
+
+} // namespace
+
 bool
 JsonRpc::process(const char* in_buffer, uint32_t length, slot_write callback) {
   json response;
   json body;
 
+  if (length > m_size_limit) {
+    auto err_str = json_error(JSONRPC_INVALID_REQUEST_ERROR, "content size exceeds maximum RPC limit", nullptr).dump();
+
+    return callback(err_str.c_str(), err_str.size());
+  }
+
   try {
-    body = json::parse(in_buffer, in_buffer + length);
+    json_depth_limited_parser handler(body);
+
+    if (!json::sax_parse(in_buffer, in_buffer + length, &handler)) {
+      auto err_str = json_error(JSONRPC_INVALID_REQUEST_ERROR, "maximum nesting depth exceeded", nullptr).dump();
+
+      return callback(err_str.c_str(), err_str.size());
+    }
+
     switch (body.type()) {
     case json::value_t::object: {
       if (!body.contains("id")) {
@@ -264,6 +303,13 @@ JsonRpc::process(const char* in_buffer, uint32_t length, slot_write callback) {
 
     std::string response_str = response.dump();
 
+    if (response_str.size() > SCgiTask::max_response_size) {
+      const auto& id = response.is_object() && response.contains("id") ? response["id"] : json(nullptr);
+      auto err_str = json_error(JSONRPC_INTERNAL_ERROR, "response size exceeds maximum RPC limit", id).dump();
+
+      return callback(err_str.c_str(), err_str.size());
+    }
+
     return callback(response_str.c_str(), response_str.size());
 
   } catch (json::exception& e) {

src/rpc/jsonrpc.h

@@ -5,6 +5,8 @@
 
 #include <cstdint>
 
+#include "rpc/scgi_task.h"
+
 namespace rpc {
 
 class JsonRpc {
@@ -17,6 +19,11 @@ public:
   bool process(const char* in_buffer, uint32_t length, slot_write callback);
 
   void insert_command(const char* name, const char* parm, const char* doc) {};
+
+  void set_size_limit(uint64_t size) { m_size_limit = size; }
+
+private:
+  uint64_t m_size_limit{SCgiTask::max_content_size};
 };
 
 } // namespace rpc

src/rpc/object_storage.cc

@@ -26,10 +26,7 @@ const size_t object_storage::key_size;
 
 object_storage::iterator
 object_storage::find_raw_string(const torrent::raw_string& key) {
-  fixed_key_type<64> k;
-  k.set_c_str(key.data());
-
-  return find(k);
+  return find(key_type::from_raw_string(key));
 }
 
 object_storage::iterator
@@ -64,8 +61,12 @@ object_storage::insert(const char* key_data, uint32_t key_size, const torrent::O
   if (std::find(key_data, key_data + key_size, '\0') != key_data + key_size)
     throw torrent::input_error("Found nul-char in string.");
 
-  // Check for size > key_size.
-  // Check for empty string.
+  // key_type turns a key this long into the empty key.
+  if (key_size >= object_storage::key_size)
+    throw torrent::input_error("Key is too long.");
+
+  if (key_size == 0)
+    throw torrent::input_error("Key is empty.");
 
   bool use_raw = false;
   torrent::Object object;

src/rpc/object_storage.h

@@ -158,14 +158,7 @@ fixed_key_type<MaxSize>::set_data(const value_type* src_data, size_type src_size
 
 template <size_t MaxSize> inline void
 fixed_key_type<MaxSize>::set_c_str(const value_type* src_data) {
-  value_type* itr = m_data;
-  const value_type* last = m_data + max_size;
-
-  while (itr != last && *src_data != '\0')
-    *itr++ = *src_data++;
-
-  *itr = '\0';
-  m_size = std::distance(m_data, itr);
+  set_c_str(src_data, std::strlen(src_data));
 }
 
 template <size_t MaxSize> inline void

src/rpc/parse_commands.cc

@@ -181,6 +181,11 @@ parse_command_file(const std::string& path) {
       getCount = 0;
     }
 
+    if (file.fail() && !file.eof()) {
+      lineNumber++;
+      throw torrent::input_error("Exceeded max line length.");
+    }
+
   } catch (torrent::input_error& e) {
     snprintf(buffer, 2048, "Error in option file: %s:%u: %s", path.c_str(), lineNumber, e.what());
 

src/rpc/rpc_manager.cc

@@ -172,7 +172,11 @@ RpcManager::set_size_limit(uint64_t size) {
   if (size > SCgiTask::max_content_size)
     throw torrent::input_error("XMLRPC size limit cannot exceed the SCGI content size limit.");
 
+  if (size < min_size_limit)
+    throw torrent::input_error("XMLRPC size limit is too small to hold a request.");
+
   m_xmlrpc.set_size_limit(size);
+  m_jsonrpc.set_size_limit(size);
 }
 
 void

src/rpc/rpc_manager.h

@@ -53,6 +53,10 @@ public:
   enum RPCType { XML,
                  JSON };
 
+  // A limit below the shortest useful request rejects every request, the one
+  // that would raise it again included.
+  static constexpr uint64_t min_size_limit = 1024;
+
   RpcManager()  = default;
   ~RpcManager() = default;
 

src/rpc/scgi_task.cc

@@ -93,7 +93,8 @@ SCgiTask::close() {
   // The callbacks are guaranteed to be finished/canceled at this point.
   auto lock = std::lock_guard<std::mutex>(m_result_mutex);
 
-  m_buffer.clear();
+  // clear() would keep the capacity, and the task is pooled for the lifetime of the process.
+  std::vector<char>().swap(m_buffer);
 }
 
 void
@@ -404,7 +405,7 @@ void
 SCgiTask::receive_write(const char* buffer, uint32_t length) {
   assert(torrent::this_thread::thread() == torrent::main_thread::thread());
 
-  if (buffer == nullptr || length > (100 << 20))
+  if (buffer == nullptr || length > max_response_size)
     throw torrent::internal_error("SCgiTask::receive_write(...) received bad input.");
 
   // Main thread callback already locked this mutex.

src/rpc/scgi_task.h

@@ -2,6 +2,7 @@
 #define RTORRENT_RPC_SCGI_TASK_H
 
 #include <chrono>
+#include <cstdint>
 #include <memory>
 #include <mutex>
 #include <vector>
@@ -18,6 +19,8 @@ public:
   static constexpr int max_header_size     = 2000;
   static constexpr int max_content_size    = (1 << 26);
 
+  static constexpr uint32_t max_response_size = (100 << 20);
+
   static constexpr auto timeout_request = std::chrono::seconds(60);
 
   enum ContentType { XML, JSON };

src/rpc/xmlrpc_c.cc

@@ -27,11 +27,11 @@ public:
   virtual ~xmlrpc_error_c() throw() {}
 
   virtual int         type() const throw() { return m_type; }
-  virtual const char* what() const throw() { return m_msg; }
+  virtual const char* what() const throw() { return m_msg.c_str(); }
 
 private:
   int                 m_type;
-  const char*         m_msg;
+  std::string         m_msg;
 };
 
 torrent::Object xmlrpc_to_object(xmlrpc_env* env, xmlrpc_value* value, int call_type = 0, rpc::target_type* target = NULL, std::function<void()>* deleter = NULL);
@@ -44,10 +44,9 @@ xmlrpc_list_entry_to_object(xmlrpc_env* env, xmlrpc_value* src, int index) {
   if (env->fault_occurred)
     throw xmlrpc_error_c(env);
 
-  torrent::Object obj = xmlrpc_to_object(env, tmp);
-  xmlrpc_DECREF(tmp);
+  utils::scope_guard guard([tmp]() { xmlrpc_DECREF(tmp); });
 
-  return obj;
+  return xmlrpc_to_object(env, tmp);
 }
 
 int64_t
@@ -213,11 +212,11 @@ xmlrpc_to_object(xmlrpc_env* env, xmlrpc_value* value, int call_type, rpc::targe
       if (env->fault_occurred)
         throw xmlrpc_error_c(env);
 
+      utils::scope_guard guard([tmp]() { xmlrpc_DECREF(tmp); });
+
       if (target != nullptr)
         std::tie(*target, *deleter) = xmlrpc_to_target(env, tmp, call_type);
 
-      xmlrpc_DECREF(tmp);
-
       if (env->fault_occurred)
         throw xmlrpc_error_c(env);
 

src/rpc/xmlrpc_tinyxml2.cc

@@ -19,6 +19,7 @@
 #include "rpc/tinyxml2/tinyxml2.h"
 #include "rpc/rpc_manager.h"
 #include "utils/base64.h"
+#include "utils/functional.h"
 #include "xmlrpc.h"
 
 namespace rpc {
@@ -258,6 +259,8 @@ execute_command(std::string method_name, const tinyxml2::XMLElement* params_elem
   torrent::Object             params_raw = torrent::Object::create_list();
   torrent::Object::list_type& params     = params_raw.as_list();
   rpc::target_type            target     = rpc::make_target();
+  std::function<void()>       deleter    = []() {};
+  utils::scope_guard          guard([&deleter]() { deleter(); });
 
   if (params_element != nullptr) {
     if (std::strncmp(params_element->Name(), "params", sizeof("params")) == 0) {
@@ -265,8 +268,6 @@ execute_command(std::string method_name, const tinyxml2::XMLElement* params_elem
       const auto* child = params_element->FirstChildElement("param");
 
       if (child != nullptr) {
-        std::function<void()> deleter = []() {};
-
         RpcManager::object_to_target(xml_value_to_object(child->FirstChildElement("value")), cmd_itr->second.m_flags, &target, &deleter);
         child = child->NextSiblingElement("param");
 
@@ -282,8 +283,6 @@ execute_command(std::string method_name, const tinyxml2::XMLElement* params_elem
       const auto* child = params_element->FirstChildElement("data")->FirstChildElement("value");
 
       if (child != nullptr) {
-        std::function<void()> deleter = []() {};
-
         RpcManager::object_to_target(xml_value_to_object(child), cmd_itr->second.m_flags, &target, &deleter);
         child = child->NextSiblingElement("value");
 
@@ -327,15 +326,20 @@ process_document(const tinyxml2::XMLDocument* doc, tinyxml2::XMLPrinter* printer
     auto& result_list     = result.as_list();
     auto  parent_elements = element_access(doc->RootElement(), {"params", "param", "value", "array", "data"});
     for (auto child = parent_elements->FirstChildElement("value"); child; child = child->NextSiblingElement("value")) {
-      auto sub_method_name = element_access(child, {"struct", "member", "value", "string"})->GetText();
+      auto method_name_member = element_access(child, {"struct", "member"});
+      auto member_name        = method_name_member->FirstChildElement("name");
+
+      if (member_name == nullptr || member_name->GetText() == nullptr ||
+          std::strncmp(member_name->GetText(), "methodName", sizeof("methodName")) != 0)
+        throw rpc_error(XMLRPC_PARSE_ERROR, "multicall struct's first member must be methodName");
+
+      auto sub_method_name = element_access(method_name_member, {"value", "string"})->GetText();
 
       if (sub_method_name == nullptr)
         throw rpc_error(XMLRPC_PARSE_ERROR, "multicall methodName element is empty");
       // If sub_params ends up a nullptr at the end of this if-chian,
       // execute_command will turn it into an empty list
-      auto sub_params = element_access(child, {"struct", "member"});
-      if (sub_params != nullptr)
-        sub_params = sub_params->NextSiblingElement("member");
+      auto sub_params = method_name_member->NextSiblingElement("member");
       if (sub_params != nullptr)
         sub_params = sub_params->FirstChildElement("value");
       if (sub_params != nullptr)
@@ -426,6 +430,14 @@ XmlRpc::process(const char* inBuffer, uint32_t length, slot_write slotWrite) {
     // remains.
     tinyxml2::XMLPrinter printer(nullptr, true, 0);
     process_document(&doc, &printer);
+
+    if (printer.CStrSize() - 1 > static_cast<int>(SCgiTask::max_response_size)) {
+      tinyxml2::XMLPrinter fault_printer(nullptr, true, 0);
+      print_xmlrpc_fault(XMLRPC_LIMIT_EXCEEDED_ERROR, "Response size exceeds maximum XML-RPC limit", &fault_printer);
+
+      return slotWrite(fault_printer.CStr(), fault_printer.CStrSize() - 1);
+    }
+
     return slotWrite(printer.CStr(), printer.CStrSize() - 1);
   } catch (rpc_error& e) {
     tinyxml2::XMLPrinter printer(nullptr, true, 0);

src/session/download_storer.cc

@@ -2,6 +2,7 @@
 
 #include "download_storer.h"
 
+#include <cerrno>
 #include <fcntl.h>
 #include <fstream>
 #include <unistd.h>
@@ -116,28 +117,36 @@ is_correct_format(const std::string& f) {
 
 void
 save_stream(const std::string& path, bool use_fsyncdisk, const std::stringstream& stream) {
-  std::fstream output(path.c_str(), std::ios::out | std::ios::trunc);
+  // Remove any leftover temporary file first so that O_EXCL only ever fails on
+  // an entry that appeared after the unlink, and O_NOFOLLOW keeps a symlink
+  // planted in the session directory from redirecting the write.
+  if (::unlink(path.c_str()) == -1 && errno != ENOENT)
+    throw torrent::storage_error("failed to remove stale file : " + path);
 
   // TODO: If we cannot open more files, wait for some to finish and try again.
-  if (!output.is_open())
-    throw torrent::storage_error("failed to open file for writing : " + path);
-
-  output << stream.rdbuf();
-
-  if (!output.good())
-    throw torrent::storage_error("failed to write stream to file : " + path);
-
-  // The data only reaches the kernel here, so this is where a full disk is seen.
-  output.close();
-
-  if (!output.good())
-    throw torrent::storage_error("failed to flush stream to file : " + path);
-
-  // Ensure that the new file is actually written to the disk
-  int fd = ::open(path.c_str(), O_WRONLY);
+  int fd = ::open(path.c_str(), O_WRONLY | O_CREAT | O_EXCL | O_NOFOLLOW, 0600);
 
   if (fd < 0)
-    throw torrent::storage_error("failed to open file descriptor for fsync : " + path);
+    throw torrent::storage_error("failed to open file for writing : " + path);
+
+  const auto  data      = stream.view();
+  std::size_t remaining = data.size();
+  const char* cursor    = data.data();
+
+  while (remaining != 0) {
+    ssize_t result = ::write(fd, cursor, remaining);
+
+    if (result == -1) {
+      if (errno == EINTR)
+        continue;
+
+      ::close(fd);
+      throw torrent::storage_error("failed to write stream to file : " + path);
+    }
+
+    cursor    += result;
+    remaining -= result;
+  }
 
   if (use_fsyncdisk) {
 #ifdef __APPLE__
@@ -152,6 +161,7 @@ save_stream(const std::string& path, bool use_fsyncdisk, const std::stringstream
     }
   }
 
+  // A full disk may only be seen when the descriptor is closed.
   if (::close(fd) == -1)
     throw torrent::storage_error("failed to close file descriptor : " + path);
 }

src/setup.cc

@@ -86,9 +86,13 @@ config_comment_log(const std::string& command, const std::string& raw_args) {
     pos = next_pos + 1;
   }
 
-  if (command == "log.add_output")
+  if (command == "log.add_output") {
+    if (args.size() != 2)
+      throw torrent::input_error("Invalid number of arguments.");
+
     log_add_group_output_str(args[0], args[1]);
-  else if (command == "log.open_file")
+
+  } else if (command == "log.open_file")
     apply_log_open_str(0, args);
   else if (command == "log.open_file.flush")
     apply_log_open_str(log_flag_flush, args);

src/ui/download_list.cc

@@ -30,6 +30,38 @@
 
 namespace ui {
 
+std::string
+create_filter_pattern(const std::string& input) {
+  std::string pattern = input;
+
+  if (pattern.empty())
+    return pattern;
+
+  if (pattern.back() != '$')
+    pattern = pattern + ".*";
+  if (pattern.front() != '^')
+    pattern = ".*" + pattern;
+
+  std::transform(pattern.begin(), pattern.end(), pattern.begin(), ::tolower);
+  return pattern;
+}
+
+torrent::Object
+create_filter_command(const std::string& pattern) {
+  torrent::Object name = torrent::Object::create_dict_key();
+  name.as_dict_key() = "d.name";
+
+  torrent::Object args = torrent::Object::create_list();
+  args.as_list().push_back(name);
+  args.as_list().push_back(torrent::Object(pattern));
+
+  torrent::Object command = torrent::Object::create_dict_key();
+  command.as_dict_key() = "match";
+  command.as_dict_obj() = args;
+
+  return command;
+}
+
 DownloadList::DownloadList() {
   m_uiArray[DISPLAY_DOWNLOAD]      = NULL;
   m_uiArray[DISPLAY_DOWNLOAD_LIST] = new ElementDownloadList();
@@ -319,16 +351,12 @@ DownloadList::receive_exit_input(Input type) {
         current_view()->filter();
         current_view()->sort();
       } else {
-        std::string pattern = input->str();
-        if (pattern.back() != '$')
-          pattern = pattern + ".*";
-        if (pattern.front() != '^')
-          pattern = ".*" + pattern;
-        std::transform(pattern.begin(), pattern.end(), pattern.begin(), ::tolower);
-        std::string temp_filter = "match={d.name=," + pattern + "}";
+        std::string pattern = create_filter_pattern(input->str());
+
         if (rpc::call_command_value("view.filter.temp.log"))
           control->core()->push_log_std("Temporary filter on '" + current_view()->name() + "' view: " + pattern);
-        current_view()->set_filter_temp(temp_filter);
+
+        current_view()->set_filter_temp(create_filter_command(pattern));
         current_view()->filter();
       }
       break;

src/ui/download_list.h

@@ -1,6 +1,9 @@
 #ifndef RTORRENT_UI_DOWNLOAD_LIST_H
 #define RTORRENT_UI_DOWNLOAD_LIST_H
 
+#include <string>
+#include <torrent/object.h>
+
 #include "element_base.h"
 #include "globals.h"
 #include "display/manager.h"
@@ -29,6 +32,12 @@ namespace ui {
 
 class Download;
 
+// Wrap a user-typed download name pattern in the anchors 'match' expects.
+std::string     create_filter_pattern(const std::string& input);
+
+// Build the 'match' command the temporary view filter runs against d.name.
+torrent::Object create_filter_command(const std::string& pattern);
+
 class DownloadList : public ElementBase {
 public:
   typedef display::WindowDownloadList              WList;

src/ui/root.cc

@@ -467,6 +467,9 @@ Root::save_input_history() {
         history_file << entry << "|" + category.at((pitr->second + i) % m_input_history_length) + "\n";
   }
 
+  // The data only reaches the kernel here, so this is where a full disk is seen.
+  history_file.close();
+
   if (!history_file.good()) {
     lt_log_print(torrent::LOG_DEBUG, "input history file corrupted during writing, discarding (path:%s)", history_filename.c_str());
     return;
@@ -474,8 +477,6 @@ Root::save_input_history() {
     lt_log_print(torrent::LOG_DEBUG, "input history file written (path:%s)", history_filename.c_str());
   }
 
-  history_file.close();
-
   std::rename(history_filename_tmp.c_str(), history_filename.c_str());
 }
 

src/ui/root.h

@@ -70,10 +70,6 @@ public:
   void                set_down_throttle(unsigned int throttle);
   void                set_up_throttle(unsigned int throttle);
 
-  // Rename to raw or something, make base function.
-  void                set_down_throttle_i64(int64_t throttle) { set_down_throttle(throttle >> 10); }
-  void                set_up_throttle_i64(int64_t throttle)   { set_up_throttle(throttle >> 10); }
-
   void                adjust_down_throttle(int throttle);
   void                adjust_up_throttle(int throttle);
 

src/utils/directory.cc

@@ -5,6 +5,7 @@
 #include <algorithm>
 #include <cstdlib>
 #include <dirent.h>
+#include <fcntl.h>
 #include <functional>
 #include <sys/stat.h>
 #include <torrent/exceptions.h>
@@ -13,6 +14,24 @@
 
 namespace utils {
 
+namespace {
+
+uint8_t
+entry_type_from_mode(mode_t mode) {
+  if (S_ISREG(mode))
+    return DT_REG;
+
+  if (S_ISDIR(mode))
+    return DT_DIR;
+
+  if (S_ISLNK(mode))
+    return DT_LNK;
+
+  return DT_UNKNOWN;
+}
+
+} // namespace
+
 // Keep this?
 bool
 Directory::is_valid() const {
@@ -38,9 +57,6 @@ Directory::update(int flags) {
     return false;
 
   struct dirent* entry;
-#ifdef __sun__
-  struct stat s;
-#endif
 
   while ((entry = readdir(d)) != NULL) {
     if ((flags & update_hide_dot) && entry->d_name[0] == '.')
@@ -49,16 +65,22 @@ Directory::update(int flags) {
     iterator itr = base_type::insert(end(), value_type());
 
 #ifdef __sun__
-    stat(entry->d_name, &s);
     itr->s_fileno = entry->d_ino;
     itr->s_reclen = 0;
-    itr->s_type = s.st_mode;
+    itr->s_type   = DT_UNKNOWN;
 #else
     itr->s_fileno = entry->d_fileno;
     itr->s_reclen = entry->d_reclen;
     itr->s_type   = entry->d_type;
 #endif
 
+    if (itr->s_type == DT_UNKNOWN) {
+      struct stat st;
+
+      if (fstatat(dirfd(d), entry->d_name, &st, AT_SYMLINK_NOFOLLOW) == 0)
+        itr->s_type = entry_type_from_mode(st.st_mode);
+    }
+
 #ifdef DIRENT_NAMLEN_EXISTS_FOOBAR
     itr->s_name   = std::string(entry->d_name, entry->d_name + entry->d_namlen);
 #else

src/utils/directory.h

@@ -2,14 +2,14 @@
 #define RTORRENT_UTILS_DIRECTORY_H
 
 #include <cstdint>
+#include <dirent.h>
 #include <string>
 #include <vector>
 
 namespace utils {
 
 struct directory_entry {
-  // Fix.
-  bool is_file() const { return true; }
+  bool is_file() const { return s_type == DT_REG; }
 
   // The name and types should match POSIX.
   uint32_t            s_fileno;

test/Makefile.am

@@ -1,4 +1,5 @@
 TESTS = \
+	rtorrent_Test_Core \
 	rtorrent_Test_Rpc \
 	rtorrent_Test_Src
 
@@ -7,6 +8,7 @@ check_PROGRAMS = $(TESTS)
 rtorrent_Test_LDADD = \
 	../src/libsub_root.a
 
+rtorrent_Test_Core_LDADD = $(rtorrent_Test_LDADD)
 rtorrent_Test_Rpc_LDADD = $(rtorrent_Test_LDADD)
 rtorrent_Test_Src_LDADD = $(rtorrent_Test_LDADD)
 
@@ -30,6 +32,10 @@ rtorrent_Test_Common = \
 	helpers/test_utils.h \
 	helpers/utils.h
 
+rtorrent_Test_Core_SOURCES = $(rtorrent_Test_Common) \
+	core/test_view.cc \
+	core/test_view.h
+
 rtorrent_Test_Rpc_SOURCES = $(rtorrent_Test_Common) \
 	rpc/test_command.cc \
 	rpc/test_command.h \
@@ -46,7 +52,9 @@ rtorrent_Test_Rpc_SOURCES = $(rtorrent_Test_Common) \
 	rpc/test_object_storage.cc \
 	rpc/test_object_storage.h \
 	rpc/test_parse_options.cc \
-	rpc/test_parse_options.h
+	rpc/test_parse_options.h \
+	rpc/test_rpc_manager.cc \
+	rpc/test_rpc_manager.h
 
 rtorrent_Test_Src_SOURCES = $(rtorrent_Test_Common) \
 	src/test_command_dynamic.cc \
@@ -59,9 +67,19 @@ rtorrent_Test_Src_SOURCES = $(rtorrent_Test_Common) \
 	src/test_command_path.h \
 	src/test_command_string.cc \
 	src/test_command_string.h \
+	src/test_command_throttle.cc \
+	src/test_command_throttle.h \
+	src/test_session_storer.cc \
+	src/test_session_storer.h \
+	src/test_setup.cc \
+	src/test_setup.h \
+	src/test_ui_download_list.cc \
+	src/test_ui_download_list.h \
 	src/test_watch_ready_queue.cc \
 	src/test_watch_ready_queue.h
 
+rtorrent_Test_Core_CXXFLAGS = $(CPPUNIT_CFLAGS)
+rtorrent_Test_Core_LDFLAGS = $(CPPUNIT_LIBS) -ldl
 rtorrent_Test_Rpc_CXXFLAGS = $(CPPUNIT_CFLAGS)
 rtorrent_Test_Rpc_LDFLAGS = $(CPPUNIT_LIBS) -ldl
 rtorrent_Test_Src_CXXFLAGS = $(CPPUNIT_CFLAGS)

test/core/test_view.cc

@@ -0,0 +1,158 @@
+#include "config.h"
+
+#include "test/core/test_view.h"
+
+#include <algorithm>
+#include <cstddef>
+#include <deque>
+#include <memory>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "command_helpers.h"
+#include "control.h"
+#include "core/download.h"
+#include "core/view.h"
+#include "globals.h"
+#include "rpc/parse_commands.h"
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestView);
+
+namespace {
+
+const char* filter_command  = "test.view.filter";
+const char* added_command   = "test.view.event_added";
+const char* removed_command = "test.view.event_removed";
+
+// View only stores these and hands them to the command layer as RPC targets,
+// which casts the pointer without reading through it.
+struct download_stub {
+  alignas(core::Download) std::byte storage[sizeof(core::Download)];
+};
+
+std::deque<download_stub>    stub_storage;
+std::vector<core::Download*> stub_downloads;
+
+std::set<core::Download*>    matches_filter;
+std::vector<core::Download*> added_events;
+std::vector<core::Download*> removed_events;
+
+std::shared_ptr<core::Download>
+make_stub_download() {
+  auto download = reinterpret_cast<core::Download*>(&stub_storage.emplace_back());
+
+  stub_downloads.push_back(download);
+
+  return std::shared_ptr<core::Download>(download, [](core::Download*) {});
+}
+
+// Renders a dispatch list as "d0,d2" so a failure names the downloads the
+// handler saw, not just how many there were.
+std::string
+describe(const std::vector<core::Download*>& downloads) {
+  std::string result;
+
+  for (const auto& download : downloads) {
+    auto itr = std::find(stub_downloads.begin(), stub_downloads.end(), download);
+
+    if (!result.empty())
+      result += ',';
+
+    result += 'd' + std::to_string(std::distance(stub_downloads.begin(), itr));
+  }
+
+  return result;
+}
+
+torrent::Object
+cmd_filter(core::Download* download, const torrent::Object&) {
+  return torrent::Object(static_cast<int64_t>(matches_filter.count(download)));
+}
+
+torrent::Object
+cmd_event_added(core::Download* download, const torrent::Object&) {
+  added_events.push_back(download);
+  return torrent::Object();
+}
+
+torrent::Object
+cmd_event_removed(core::Download* download, const torrent::Object&) {
+  removed_events.push_back(download);
+  return torrent::Object();
+}
+
+torrent::Object
+command_object(const char* command) {
+  return torrent::Object(std::string(command) + "=");
+}
+
+} // namespace
+
+void
+TestView::setUp() {
+  TestFixtureWithMainThread::setUp();
+
+  if (control == nullptr)
+    control = new Control;
+
+  if (!rpc::commands.has(filter_command)) {
+    CMD2_DL(filter_command, &cmd_filter);
+    CMD2_DL(added_command, &cmd_event_added);
+    CMD2_DL(removed_command, &cmd_event_removed);
+  }
+
+  stub_storage.clear();
+  stub_downloads.clear();
+  matches_filter.clear();
+  added_events.clear();
+  removed_events.clear();
+}
+
+void
+TestView::tearDown() {
+  TestFixtureWithMainThread::tearDown();
+}
+
+// d0 and d1 start visible and stop matching, d2 and d3 start filtered out and
+// start matching. The two halves are the same size on purpose: a test that
+// only counted the dispatches would pass even if both events were sent over
+// the same half of the changed range.
+void
+TestView::test_filter_dispatches_events_to_the_right_downloads() {
+  core::View view;
+  view.initialize("test_view");
+
+  auto d0 = make_stub_download();
+  auto d1 = make_stub_download();
+  auto d2 = make_stub_download();
+  auto d3 = make_stub_download();
+
+  view.insert(d0);
+  view.insert(d1);
+  view.insert(d2);
+  view.insert(d3);
+
+  view.set_visible(d0.get());
+  view.set_visible(d1.get());
+
+  CPPUNIT_ASSERT_EQUAL(core::View::size_type(2), view.size_visible());
+
+  matches_filter = {d2.get(), d3.get()};
+
+  view.set_filter(command_object(filter_command));
+  view.set_event_added(command_object(added_command));
+  view.set_event_removed(command_object(removed_command));
+
+  added_events.clear();
+  removed_events.clear();
+
+  view.filter();
+
+  CPPUNIT_ASSERT_EQUAL(std::string("d2,d3"), describe(added_events));
+  CPPUNIT_ASSERT_EQUAL(std::string("d0,d1"), describe(removed_events));
+
+  CPPUNIT_ASSERT_EQUAL(core::View::size_type(2), view.size_visible());
+  CPPUNIT_ASSERT(*view.begin_visible() == d2);
+  CPPUNIT_ASSERT(*(view.begin_visible() + 1) == d3);
+}

test/core/test_view.h

@@ -0,0 +1,15 @@
+#include "test/helpers/test_main_thread.h"
+
+class TestView : public TestFixtureWithMainThread {
+  CPPUNIT_TEST_SUITE(TestView);
+
+  CPPUNIT_TEST(test_filter_dispatches_events_to_the_right_downloads);
+
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  void setUp();
+  void tearDown();
+
+  void test_filter_dispatches_events_to_the_right_downloads();
+};

test/rpc/test_jsonrpc.cc

@@ -8,12 +8,18 @@
 #include "globals.h"
 #include "command_helpers.h"
 #include "rpc/command_map.h"
+#include "rpc/scgi_task.h"
 
 CPPUNIT_TEST_SUITE_REGISTRATION(TestJsonrpc);
 
 torrent::Object
 jsonrpc_cmd_test_reflect([[maybe_unused]] rpc::target_type t, const torrent::Object& obj) { return obj; }
 
+torrent::Object
+jsonrpc_cmd_test_oversized([[maybe_unused]] rpc::target_type t, [[maybe_unused]] const torrent::Object& obj) {
+  return torrent::Object(std::string(rpc::SCgiTask::max_response_size + (1 << 20), 'a'));
+}
+
 void initialize_command_dynamic();
 
 // Name, Request, Expected response
@@ -130,6 +136,10 @@ TestJsonrpc::setUp() {
   if (rpc::commands.find("jsonrpc_reflect") == rpc::commands.end()) {
     CMD2_ANY("jsonrpc_reflect", &jsonrpc_cmd_test_reflect);
   }
+
+  if (rpc::commands.find("jsonrpc_oversized") == rpc::commands.end()) {
+    CMD2_ANY("jsonrpc_oversized", &jsonrpc_cmd_test_oversized);
+  }
 }
 
 void
@@ -145,3 +155,100 @@ TestJsonrpc::test_basics() {
     CPPUNIT_ASSERT_EQUAL_MESSAGE(std::get<0>(test), std::get<2>(test), output);
   }
 }
+
+// A command whose result does not fit in the SCGI response buffer must be
+// answered with a fault, not handed to the writer. SCgiTask::receive_write
+// treats an oversized body as an internal_error, which is not caught by any
+// RPC handler and terminates the process.
+void
+TestJsonrpc::test_response_size_limit() {
+  const std::string request = R"({"jsonrpc": "2.0", "method": "jsonrpc_oversized", "params": [""], "id": 1})";
+  const std::string expected = R"({"error":{"code":-32000,"message":"response size exceeds maximum RPC limit"},"id":1,"jsonrpc":"2.0"})";
+
+  std::string output;
+  m_jsonrpc.process(request.c_str(), request.size(), [&output](const char* c, uint32_t l) { output.append(c, l); return true; });
+
+  CPPUNIT_ASSERT_MESSAGE("response handed to the writer is " + std::to_string(output.size()) +
+                         " bytes, over the " + std::to_string(rpc::SCgiTask::max_response_size) + " byte SCGI limit",
+                         output.size() <= rpc::SCgiTask::max_response_size);
+  CPPUNIT_ASSERT_EQUAL(expected, output);
+}
+
+// The bound is applied while the document is parsed: json_to_object only ever
+// walks "params", and by the time it runs the whole tree already exists.
+void
+TestJsonrpc::test_depth_limit() {
+  // A JSON string holding a quote and brackets that must not be counted.
+  const std::string tricky = R"("\"[[[")";
+
+  std::vector<std::tuple<std::string, std::string, std::string>> requests = {
+    std::make_tuple("Nesting under the limit is accepted",
+                    R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": ["", )" +
+                      std::string(1000, '[') + std::string(1000, ']') + R"(], "id": 1})",
+                    R"({"id":1,"jsonrpc":"2.0","result":[)" +
+                      std::string(1000, '[') + std::string(1000, ']') + R"(]})"),
+
+    // Nesting outside "params" is never converted, so json_to_object's own
+    // bound never sees it.
+    std::make_tuple("Nesting outside params is rejected",
+                    R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": [""], "id": 1, "x": )" +
+                      std::string(2000, '[') + std::string(2000, ']') + R"(})",
+                    R"({"error":{"code":-32600,"message":"maximum nesting depth exceeded"},"id":null,"jsonrpc":"2.0"})"),
+
+    std::make_tuple("Nesting over the limit is rejected",
+                    R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": ["", )" +
+                      std::string(2000, '[') + std::string(2000, ']') + R"(], "id": 1})",
+                    R"({"error":{"code":-32600,"message":"maximum nesting depth exceeded"},"id":null,"jsonrpc":"2.0"})"),
+
+    std::make_tuple("Brackets inside a string are not nesting",
+                    R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": ["", ")" +
+                      std::string(2000, '[') + R"("], "id": 1})",
+                    R"({"id":1,"jsonrpc":"2.0","result":[")" +
+                      std::string(2000, '[') + R"("]})"),
+
+    std::make_tuple("An escaped quote does not end a string",
+                    R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": ["", )" + tricky + R"(, ")" +
+                      std::string(2000, '[') + R"("], "id": 1})",
+                    R"({"id":1,"jsonrpc":"2.0","result":[)" + tricky + R"(,")" +
+                      std::string(2000, '[') + R"("]})"),
+
+    // The bound is on the whole document, so the outer object and the params
+    // array are two of the 1024 containers and 1022 are left for the payload.
+    std::make_tuple("Nesting one below the limit is accepted",
+                    R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": ["", )" +
+                      std::string(1021, '[') + std::string(1021, ']') + R"(], "id": 1})",
+                    R"({"id":1,"jsonrpc":"2.0","result":[)" +
+                      std::string(1021, '[') + std::string(1021, ']') + R"(]})"),
+
+    std::make_tuple("Nesting at the limit is accepted",
+                    R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": ["", )" +
+                      std::string(1022, '[') + std::string(1022, ']') + R"(], "id": 1})",
+                    R"({"id":1,"jsonrpc":"2.0","result":[)" +
+                      std::string(1022, '[') + std::string(1022, ']') + R"(]})"),
+
+    std::make_tuple("Nesting one over the limit is rejected",
+                    R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": ["", )" +
+                      std::string(1023, '[') + std::string(1023, ']') + R"(], "id": 1})",
+                    R"({"error":{"code":-32600,"message":"maximum nesting depth exceeded"},"id":null,"jsonrpc":"2.0"})"),
+  };
+
+  for (auto& test : requests) {
+    std::string output;
+    m_jsonrpc.process(std::get<1>(test).c_str(), std::get<1>(test).size(), [&output](const char* c, uint32_t l) { output.append(c, l); return true; });
+    CPPUNIT_ASSERT_EQUAL_MESSAGE(std::get<0>(test), std::get<2>(test), output);
+  }
+}
+
+// network.xmlrpc.size_limit is the only knob bounding how much input a single
+// request may spend memory on, and it has to bound the JSON path too.
+void
+TestJsonrpc::test_size_limit() {
+  const std::string request = R"({"jsonrpc": "2.0", "method": "jsonrpc_reflect", "params": [""], "id": 1})";
+  const std::string expected = R"({"error":{"code":-32600,"message":"content size exceeds maximum RPC limit"},"id":null,"jsonrpc":"2.0"})";
+
+  std::string output;
+  m_jsonrpc.set_size_limit(1);
+  m_jsonrpc.process(request.c_str(), request.size(), [&output](const char* c, uint32_t l) { output.append(c, l); return true; });
+
+  CPPUNIT_ASSERT_EQUAL(expected, output);
+}

test/rpc/test_jsonrpc.h

@@ -8,6 +8,9 @@ class TestJsonrpc : public test_fixture {
   CPPUNIT_TEST_SUITE(TestJsonrpc);
 
   CPPUNIT_TEST(test_basics);
+  CPPUNIT_TEST(test_response_size_limit);
+  CPPUNIT_TEST(test_depth_limit);
+  CPPUNIT_TEST(test_size_limit);
 
   CPPUNIT_TEST_SUITE_END();
 
@@ -16,6 +19,9 @@ public:
   void tearDown();
 
   void test_basics();
+  void test_response_size_limit();
+  void test_depth_limit();
+  void test_size_limit();
 
 private:
   std::unique_ptr<TestMainThread> m_test_main_thread;

test/rpc/test_object_storage.cc

@@ -49,6 +49,34 @@ TestObjectStorage::test_validate_keys() {
   torrent::raw_string raw_string_4("test_4\0foo", 10);
 
   ASSERT_CATCH_INPUT_ERROR( { m_storage.insert(raw_string_4, torrent::Object("a"), rpc::object_storage::flag_string_type); } );
+  ASSERT_CATCH_INPUT_ERROR( { m_storage.insert_str("", torrent::Object("a"), rpc::object_storage::flag_string_type); } );
+
+  std::string key_max(rpc::object_storage::key_size - 1, 'k');
+
+  CPPUNIT_ASSERT(m_storage.insert_str(key_max, torrent::Object("a"), rpc::object_storage::flag_string_type)->first == key_max);
+  ASSERT_CATCH_INPUT_ERROR( { m_storage.insert_str(key_max + 'k', torrent::Object("a"), rpc::object_storage::flag_string_type); } );
+
+  // The over-long key must not have been stored as the empty key.
+  CPPUNIT_ASSERT(m_storage.find_raw_string(torrent::raw_string::from_c_str("")) == m_storage.end());
+
+  // An over-long key must not be truncated into a match either.
+  CPPUNIT_ASSERT(m_storage.find_raw_string(torrent::raw_string::from_string(key_max + 'k')) == m_storage.end());
+
+  // set_c_str puts the terminating nul at m_data[size()], so size() has to
+  // stay below max_size for that write to land inside the array.
+  rpc::object_storage::key_type key_long;
+  key_long.set_c_str(std::string(rpc::object_storage::key_size + 1, 'k').c_str());
+
+  CPPUNIT_ASSERT(key_long.size() < rpc::object_storage::key_size);
+
+  m_storage.clear();
+  m_storage.insert_str("test_5", torrent::Object("a"), rpc::object_storage::flag_string_type);
+
+  // insert rejects a key holding a nul-char, so a lookup must not match past one.
+  CPPUNIT_ASSERT(m_storage.find_raw_string(torrent::raw_string("test_5\0x", 8)) == m_storage.end());
+  CPPUNIT_ASSERT(m_storage.find_raw_string(torrent::raw_string::from_c_str("test_5")) != m_storage.end());
+
+  m_storage.clear();
 }
 
 // And test many other bad/good string combos.

test/rpc/test_rpc_manager.cc

@@ -0,0 +1,21 @@
+#include "config.h"
+
+#include "test/rpc/test_rpc_manager.h"
+
+#include <torrent/exceptions.h>
+
+#include "rpc/scgi_task.h"
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestRpcManager);
+
+// A size limit too small to hold any request rejects every request, including
+// the one that would put it back, so it can only be undone by a restart.
+void
+TestRpcManager::test_size_limit_bounds() {
+  CPPUNIT_ASSERT_THROW(m_rpc_manager.set_size_limit(0), torrent::input_error);
+  CPPUNIT_ASSERT_THROW(m_rpc_manager.set_size_limit(rpc::RpcManager::min_size_limit - 1), torrent::input_error);
+  CPPUNIT_ASSERT_THROW(m_rpc_manager.set_size_limit(rpc::SCgiTask::max_content_size + 1), torrent::input_error);
+
+  CPPUNIT_ASSERT_NO_THROW(m_rpc_manager.set_size_limit(rpc::RpcManager::min_size_limit));
+  CPPUNIT_ASSERT_NO_THROW(m_rpc_manager.set_size_limit(rpc::SCgiTask::max_content_size));
+}

test/rpc/test_rpc_manager.h

@@ -0,0 +1,17 @@
+#include "test/helpers/test_fixture.h"
+
+#include "rpc/rpc_manager.h"
+
+class TestRpcManager : public test_fixture {
+  CPPUNIT_TEST_SUITE(TestRpcManager);
+
+  CPPUNIT_TEST(test_size_limit_bounds);
+
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  void test_size_limit_bounds();
+
+private:
+  rpc::RpcManager m_rpc_manager;
+};

test/rpc/test_xmlrpc.cc

@@ -8,6 +8,7 @@
 #include "globals.h"
 #include "command_helpers.h"
 #include "rpc/command_map.h"
+#include "rpc/scgi_task.h"
 
 CPPUNIT_TEST_SUITE_REGISTRATION(TestXmlrpc);
 
@@ -21,6 +22,11 @@ xmlrpc_cmd_test_reflect_string([[maybe_unused]] rpc::target_type t, const std::s
   return obj;
 }
 
+torrent::Object
+xmlrpc_cmd_test_oversized([[maybe_unused]] rpc::target_type t, [[maybe_unused]] const torrent::Object& obj) {
+  return torrent::Object(std::string(rpc::SCgiTask::max_response_size + (1 << 20), 'a'));
+}
+
 void initialize_command_dynamic();
 
 #if defined(HAVE_XMLRPC_TINYXML2) && !defined(HAVE_XMLRPC_C)
@@ -127,6 +133,9 @@ TestXmlrpc::setUp() {
 
   if (rpc::commands.find("xmlrpc_reflect_string") == rpc::commands.end())
     CMD2_ANY_STRING("xmlrpc_reflect_string", &xmlrpc_cmd_test_reflect_string);
+
+  if (rpc::commands.find("xmlrpc_oversized") == rpc::commands.end())
+    CMD2_ANY("xmlrpc_oversized", &xmlrpc_cmd_test_oversized);
 }
 
 void
@@ -165,11 +174,72 @@ TestXmlrpc::test_size_limit() {
   CPPUNIT_ASSERT_EQUAL(expected, output);
 }
 
+// A command whose result does not fit in the SCGI response buffer must be
+// answered with a fault, not handed to the writer. SCgiTask::receive_write
+// treats an oversized body as an internal_error, which is not caught by any
+// RPC handler and terminates the process.
+void
+TestXmlrpc::test_response_size_limit() {
+  std::string input = "<?xml version=\"1.0\"?><methodCall><methodName>xmlrpc_oversized</methodName><params><param><value><string></string></value></param></params></methodCall>";
+  std::string expected = "<?xml version=\"1.0\"?><methodResponse><fault><value><struct><member><name>faultCode</name><value><i8>-509</i8></value></member><member><name>faultString</name><value><string>Response size exceeds maximum XML-RPC limit</string></value></member></struct></value></fault></methodResponse>";
+  std::string output;
+
+  m_xmlrpc.process(input.c_str(), input.size(), [&output](const char* c, uint32_t l){ output.append(c, l); return true;});
+
+  CPPUNIT_ASSERT_MESSAGE("response handed to the writer is " + std::to_string(output.size()) +
+                         " bytes, over the " + std::to_string(rpc::SCgiTask::max_response_size) + " byte SCGI limit",
+                         output.size() <= rpc::SCgiTask::max_response_size);
+  CPPUNIT_ASSERT_EQUAL(expected, output);
+}
+
+namespace {
+
+const std::string multicall_method_name =
+  "<member><name>methodName</name><value><string>xmlrpc_reflect</string></value></member>";
+const std::string multicall_params =
+  "<member><name>params</name><value><array><data>"
+  "<value><string></string></value><value><string>a</string></value>"
+  "</data></array></value></member>";
+
+std::string
+multicall_request(const std::string& members) {
+  return "<?xml version=\"1.0\"?><methodCall><methodName>system.multicall</methodName>"
+         "<params><param><value><array><data><value><struct>" + members +
+         "</struct></value></data></array></value></param></params></methodCall>";
+}
+
+}
+
+void
+TestXmlrpc::test_multicall_member_order() {
+  auto call = [this](const std::string& input) {
+    std::string output;
+    m_xmlrpc.process(input.c_str(), input.size(), [&output](const char* c, uint32_t l){ output.append(c, l); return true;});
+    return output;
+  };
+
+  // methodName first is the only order accepted; the positive control proves
+  // the harness drives the real code path rather than a stub.
+  std::string ordered = call(multicall_request(multicall_method_name + multicall_params));
+  CPPUNIT_ASSERT(ordered.find("faultCode") == std::string::npos);
+
+  // params before methodName is rejected with a clear top-level fault,
+  // instead of the "could not find expected element string" of a positional read.
+  std::string expected_fault =
+    "<?xml version=\"1.0\"?><methodResponse><fault><value><struct>"
+    "<member><name>faultCode</name><value><i8>-503</i8></value></member>"
+    "<member><name>faultString</name><value><string>multicall struct's first member must be methodName</string></value></member>"
+    "</struct></value></fault></methodResponse>";
+  CPPUNIT_ASSERT_EQUAL(expected_fault, call(multicall_request(multicall_params + multicall_method_name)));
+}
+
 #else
 
 void TestXmlrpc::test_invalid_utf8() {}
 void TestXmlrpc::test_basics() {}
 void TestXmlrpc::test_size_limit() {}
+void TestXmlrpc::test_response_size_limit() {}
+void TestXmlrpc::test_multicall_member_order() {}
 void TestXmlrpc::setUp() {}
 void TestXmlrpc::tearDown() {}
 

test/rpc/test_xmlrpc.h

@@ -10,6 +10,8 @@ class TestXmlrpc : public test_fixture {
   CPPUNIT_TEST(test_basics);
   CPPUNIT_TEST(test_invalid_utf8);
   CPPUNIT_TEST(test_size_limit);
+  CPPUNIT_TEST(test_response_size_limit);
+  CPPUNIT_TEST(test_multicall_member_order);
 
   CPPUNIT_TEST_SUITE_END();
 
@@ -22,6 +24,8 @@ public:
   void test_basics();
   void test_invalid_utf8();
   void test_size_limit();
+  void test_response_size_limit();
+  void test_multicall_member_order();
 
 private:
   std::unique_ptr<TestMainThread> m_test_main_thread;

test/src/test_command_dynamic.cc

@@ -2,6 +2,8 @@
 
 #include "test/src/test_command_dynamic.h"
 
+#include "helpers/assert.h"
+
 #include "control.h"
 #include "globals.h"
 #include "rpc/parse_commands.h"
@@ -61,3 +63,51 @@ TestCommandDynamic::test_old_style() {
   rpc::commands.call_command("method.insert", rpc::create_object_list("test_old_style.4", "simple", "cat=test.3"));
   CPPUNIT_ASSERT(rpc::commands.call_command("test_old_style.4", torrent::Object()).as_string() == "test.3");
 }
+
+void
+TestCommandDynamic::test_insert_list() {
+  torrent::Object key_only = torrent::Object::create_list();
+  key_only.as_list().push_back("test_insert_list.1");
+
+  rpc::commands.call_command("method.insert.list", key_only);
+
+  torrent::Object result = rpc::commands.call_command("test_insert_list.1", torrent::Object());
+
+  CPPUNIT_ASSERT(result.is_list());
+  CPPUNIT_ASSERT(result.as_list().empty());
+
+  rpc::commands.call_command("method.insert.list",
+                             rpc::create_object_list("test_insert_list.2", rpc::create_object_list("a", "b")));
+
+  torrent::Object filled = rpc::commands.call_command("test_insert_list.2", torrent::Object());
+
+  CPPUNIT_ASSERT(filled.is_list());
+  CPPUNIT_ASSERT_EQUAL((size_t)2, filled.as_list().size());
+}
+
+void
+TestCommandDynamic::test_value_base() {
+  auto value = [](std::initializer_list<torrent::Object> objects) {
+    auto args = torrent::Object::create_list();
+
+    for (const auto& object : objects)
+      args.as_list().push_back(object);
+
+    return rpc::commands.call_command("value", args).as_value();
+  };
+
+  CPPUNIT_ASSERT_EQUAL(int64_t(10), value({"10"}));
+  CPPUNIT_ASSERT_EQUAL(int64_t(255), value({"ff", int64_t(16)}));
+
+  // strtoll only defines base 0 and base 2 through 36.
+  ASSERT_CATCH_INPUT_ERROR( { value({"10", int64_t(1)}); } );
+  ASSERT_CATCH_INPUT_ERROR( { value({"10", int64_t(37)}); } );
+  ASSERT_CATCH_INPUT_ERROR( { value({"10", int64_t(-1)}); } );
+
+  // An out-of-range base must not be narrowed into a valid one.
+  ASSERT_CATCH_INPUT_ERROR( { value({"10", int64_t(1) << 40}); } );
+  ASSERT_CATCH_INPUT_ERROR( { value({"ff", (int64_t(1) << 32) + 16}); } );
+
+  // A number too large for the result must be rejected, not clamped.
+  ASSERT_CATCH_INPUT_ERROR( { value({"99999999999999999999999"}); } );
+}

test/src/test_command_dynamic.h

@@ -7,6 +7,8 @@ class TestCommandDynamic : public test_fixture {
   CPPUNIT_TEST(test_basics);
   CPPUNIT_TEST(test_get_set);
   CPPUNIT_TEST(test_old_style);
+  CPPUNIT_TEST(test_insert_list);
+  CPPUNIT_TEST(test_value_base);
 
   CPPUNIT_TEST_SUITE_END();
 
@@ -18,6 +20,8 @@ public:
   void test_get_set();
 
   void test_old_style();
+  void test_insert_list();
+  void test_value_base();
 
 private:
   std::unique_ptr<TestMainThread> m_test_main_thread;

test/src/test_command_throttle.cc

@@ -0,0 +1,102 @@
+#include "config.h"
+
+#include "test/src/test_command_throttle.h"
+
+#include <torrent/throttle.h>
+#include <torrent/torrent.h>
+
+#include "core/manager.h"
+#include "control.h"
+#include "globals.h"
+#include "rpc/parse_commands.h"
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestCommandThrottle);
+
+void initialize_command_throttle();
+
+static void
+call_set(const char* key, const char* value) {
+  rpc::commands.call_command(key, torrent::Object(std::string(value)));
+}
+
+static void
+call_named(const char* key, const char* name, const char* value) {
+  torrent::Object::list_type args;
+  args.push_back(torrent::Object(std::string(name)));
+  args.push_back(torrent::Object(std::string(value)));
+
+  rpc::commands.call_command(key, torrent::Object::create_list_range(args.begin(), args.end()));
+}
+
+static uint64_t
+down_rate() {
+  return torrent::down_throttle_global()->max_rate();
+}
+
+void
+TestCommandThrottle::setUp() {
+  torrent::initialize_main_thread();
+  torrent::initialize();
+
+  if (control == nullptr)
+    control = new Control;
+
+  if (!rpc::commands.has("throttle.global_down.max_rate.set_kb"))
+    initialize_command_throttle();
+}
+
+void
+TestCommandThrottle::tearDown() {
+  torrent::cleanup();
+}
+
+void
+TestCommandThrottle::test_global_rate_in_range() {
+  call_set("throttle.global_down.max_rate.set_kb", "1024");
+  CPPUNIT_ASSERT_EQUAL(uint64_t{1048576}, down_rate());
+
+  call_set("throttle.global_down.max_rate.set_kb", "4194303");
+  CPPUNIT_ASSERT_EQUAL(uint64_t{4294966272}, down_rate());
+
+  call_set("throttle.global_down.max_rate.set", "4294966272");
+  CPPUNIT_ASSERT_EQUAL(uint64_t{4294966272}, down_rate());
+}
+
+void
+TestCommandThrottle::test_global_rate_kb_out_of_range() {
+  call_set("throttle.global_down.max_rate.set_kb", "1024");
+
+  CPPUNIT_ASSERT_THROW(call_set("throttle.global_down.max_rate.set_kb", "4194304"), torrent::input_error);
+  CPPUNIT_ASSERT_EQUAL(uint64_t{1048576}, down_rate());
+}
+
+void
+TestCommandThrottle::test_global_rate_bytes_out_of_range() {
+  call_set("throttle.global_down.max_rate.set", "1048576");
+
+  CPPUNIT_ASSERT_THROW(call_set("throttle.global_down.max_rate.set", "4294967296"), torrent::input_error);
+  CPPUNIT_ASSERT_EQUAL(uint64_t{1048576}, down_rate());
+}
+
+void
+TestCommandThrottle::test_global_rate_negative() {
+  call_set("throttle.global_down.max_rate.set", "1048576");
+
+  CPPUNIT_ASSERT_THROW(call_set("throttle.global_down.max_rate.set", "-1"), torrent::input_error);
+  CPPUNIT_ASSERT_EQUAL(uint64_t{1048576}, down_rate());
+}
+
+void
+TestCommandThrottle::test_named_rate_in_range() {
+  call_named("throttle.down", "test_named_in_range", "1024");
+
+  auto itr = control->core()->throttles().find("test_named_in_range");
+
+  CPPUNIT_ASSERT(itr != control->core()->throttles().end());
+  CPPUNIT_ASSERT_EQUAL(uint64_t{1048576}, itr->second.second->max_rate());
+}
+
+void
+TestCommandThrottle::test_named_rate_out_of_range() {
+  CPPUNIT_ASSERT_THROW(call_named("throttle.down", "test_named_out_of_range", "18014398509481984"), torrent::input_error);
+}

test/src/test_command_throttle.h

@@ -0,0 +1,25 @@
+#include "test/helpers/test_fixture.h"
+
+class TestCommandThrottle : public test_fixture {
+  CPPUNIT_TEST_SUITE(TestCommandThrottle);
+
+  CPPUNIT_TEST(test_global_rate_in_range);
+  CPPUNIT_TEST(test_global_rate_kb_out_of_range);
+  CPPUNIT_TEST(test_global_rate_bytes_out_of_range);
+  CPPUNIT_TEST(test_global_rate_negative);
+  CPPUNIT_TEST(test_named_rate_in_range);
+  CPPUNIT_TEST(test_named_rate_out_of_range);
+
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  void setUp();
+  void tearDown();
+
+  void test_global_rate_in_range();
+  void test_global_rate_kb_out_of_range();
+  void test_global_rate_bytes_out_of_range();
+  void test_global_rate_negative();
+  void test_named_rate_in_range();
+  void test_named_rate_out_of_range();
+};

test/src/test_session_storer.cc

@@ -0,0 +1,152 @@
+#include "config.h"
+
+#include "test/src/test_session_storer.h"
+
+#include <cstdlib>
+#include <dirent.h>
+#include <fstream>
+#include <sstream>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "session/download_storer.h"
+#include "utils/directory.h"
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestSessionStorer);
+
+namespace {
+
+const char* entry_name = "0123456789ABCDEF0123456789ABCDEF01234567.torrent";
+const char* link_name  = "FEDCBA9876543210FEDCBA9876543210FEDCBA98.torrent";
+
+void
+write_file(const std::string& path, const std::string& content) {
+  std::ofstream file(path.c_str());
+
+  file << content;
+  file.close();
+
+  CPPUNIT_ASSERT(file.good());
+}
+
+std::string
+read_file(const std::string& path) {
+  std::ifstream    file(path.c_str());
+  std::stringstream buffer;
+
+  buffer << file.rdbuf();
+  return buffer.str();
+}
+
+void
+save_session_files(const std::string& path) {
+  std::stringstream torrent_stream("torrent-data");
+  std::stringstream rtorrent_stream("rtorrent-data");
+  std::stringstream libtorrent_stream("libtorrent-data");
+
+  session::DownloadStorer::save_and_move_streams(path, false, &torrent_stream, &rtorrent_stream, &libtorrent_stream);
+}
+
+unsigned int
+permissions_of(const std::string& path) {
+  struct stat st;
+
+  CPPUNIT_ASSERT_EQUAL(0, ::stat(path.c_str(), &st));
+  return st.st_mode & 07777;
+}
+
+void
+remove_directory(const std::string& path) {
+  DIR* d = ::opendir(path.c_str());
+
+  if (d == NULL)
+    return;
+
+  struct dirent* entry;
+
+  while ((entry = ::readdir(d)) != NULL) {
+    if (entry->d_name[0] == '.' && (entry->d_name[1] == '\0' || (entry->d_name[1] == '.' && entry->d_name[2] == '\0')))
+      continue;
+
+    ::unlink((path + "/" + entry->d_name).c_str());
+  }
+
+  ::closedir(d);
+  ::rmdir(path.c_str());
+}
+
+} // namespace
+
+void
+TestSessionStorer::setUp() {
+  test_fixture::setUp();
+
+  char temp_dir[] = "/tmp/rtorrent_test_session_XXXXXX";
+
+  CPPUNIT_ASSERT(mkdtemp(temp_dir) != nullptr);
+
+  m_temp_dir    = temp_dir;
+  m_session_dir = m_temp_dir + "/session";
+
+  CPPUNIT_ASSERT_EQUAL(0, ::mkdir(m_session_dir.c_str(), 0755));
+}
+
+void
+TestSessionStorer::tearDown() {
+  remove_directory(m_session_dir);
+  remove_directory(m_temp_dir);
+
+  test_fixture::tearDown();
+}
+
+// A symlink planted where the next temporary session file will be written must
+// not redirect the write to the file it points at.
+void
+TestSessionStorer::test_temp_file_symlink_is_not_followed() {
+  auto outside = m_temp_dir + "/outside.txt";
+  auto path    = m_session_dir + "/" + entry_name;
+
+  write_file(outside, "original");
+  CPPUNIT_ASSERT_EQUAL(0, ::symlink(outside.c_str(), (path + ".new").c_str()));
+
+  save_session_files(path);
+
+  CPPUNIT_ASSERT_EQUAL(std::string("original"), read_file(outside));
+  CPPUNIT_ASSERT_EQUAL(std::string("torrent-data"), read_file(path));
+}
+
+// Session files carry tracker announce urls, so they must not be readable by
+// other users regardless of the umask rtorrent was started with.
+void
+TestSessionStorer::test_saved_files_are_owner_only() {
+  auto path       = m_session_dir + "/" + entry_name;
+  auto prev_umask = ::umask(0);
+
+  save_session_files(path);
+  ::umask(prev_umask);
+
+  CPPUNIT_ASSERT_EQUAL(0600u, permissions_of(path));
+  CPPUNIT_ASSERT_EQUAL(0600u, permissions_of(path + ".rtorrent"));
+  CPPUNIT_ASSERT_EQUAL(0600u, permissions_of(path + ".libtorrent_resume"));
+}
+
+// Entries listed for loading must report their real type so that a symlink in
+// the session directory is skipped instead of loaded.
+void
+TestSessionStorer::test_symlinked_entry_is_not_a_file() {
+  write_file(m_temp_dir + "/outside.txt", "d0:e");
+  write_file(m_session_dir + "/" + entry_name, "d0:e");
+
+  CPPUNIT_ASSERT_EQUAL(0, ::symlink((m_temp_dir + "/outside.txt").c_str(), (m_session_dir + "/" + link_name).c_str()));
+
+  auto entries = session::DownloadStorer::get_formated_entries(m_session_dir + "/");
+
+  CPPUNIT_ASSERT_EQUAL(size_t{2}, size_t{entries.size()});
+
+  for (const auto& entry : entries) {
+    if (entry.s_name == entry_name)
+      CPPUNIT_ASSERT(entry.is_file());
+    else
+      CPPUNIT_ASSERT(!entry.is_file());
+  }
+}

test/src/test_session_storer.h

@@ -0,0 +1,25 @@
+#include "test/helpers/test_fixture.h"
+
+#include <string>
+
+class TestSessionStorer : public test_fixture {
+  CPPUNIT_TEST_SUITE(TestSessionStorer);
+
+  CPPUNIT_TEST(test_temp_file_symlink_is_not_followed);
+  CPPUNIT_TEST(test_saved_files_are_owner_only);
+  CPPUNIT_TEST(test_symlinked_entry_is_not_a_file);
+
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  void setUp();
+  void tearDown();
+
+  void test_temp_file_symlink_is_not_followed();
+  void test_saved_files_are_owner_only();
+  void test_symlinked_entry_is_not_a_file();
+
+private:
+  std::string m_temp_dir;
+  std::string m_session_dir;
+};

test/src/test_setup.cc

@@ -0,0 +1,78 @@
+#include "config.h"
+
+#include "test/src/test_setup.h"
+
+#include <fstream>
+#include <string>
+#include <unistd.h>
+#include <torrent/exceptions.h>
+
+#include "setup.h"
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestSetup);
+
+// Linking setup.o pulls in the help printer, which lives in src/main.cc.
+void
+print_help() {}
+
+namespace {
+
+class temp_config_file {
+public:
+  temp_config_file(const std::string& contents) {
+    char path[] = "/tmp/rtorrent_test_setup_XXXXXX";
+
+    CPPUNIT_ASSERT(::mkstemp(path) != -1);
+    m_path = path;
+
+    std::ofstream file(m_path);
+    file << contents << '\n';
+  }
+
+  ~temp_config_file() { ::unlink(m_path.c_str()); }
+
+  const std::string& path() const { return m_path; }
+
+private:
+  std::string m_path;
+};
+
+// The group name must be a valid one, else option_find_string throws before
+// the output argument is ever touched.
+void
+assert_arg_count_error(const std::string& line) {
+  temp_config_file file(line);
+
+  try {
+    parse_config_file_comments(file.path());
+  } catch (torrent::input_error& e) {
+    CPPUNIT_ASSERT_EQUAL(std::string("Invalid number of arguments."), std::string(e.what()));
+    return;
+  }
+
+  CPPUNIT_FAIL("no torrent::input_error thrown for: " + line);
+}
+
+} // namespace
+
+void
+TestSetup::test_config_comment_log_add_output() {
+  temp_config_file file("# do:log.add_output=debug,test_output");
+
+  CPPUNIT_ASSERT_NO_THROW(parse_config_file_comments(file.path()));
+}
+
+void
+TestSetup::test_config_comment_log_add_output_no_args() {
+  assert_arg_count_error("# do:log.add_output=");
+}
+
+void
+TestSetup::test_config_comment_log_add_output_one_arg() {
+  assert_arg_count_error("# do:log.add_output=debug");
+}
+
+void
+TestSetup::test_config_comment_log_add_output_too_many_args() {
+  assert_arg_count_error("# do:log.add_output=debug,test_output,extra");
+}

test/src/test_setup.h

@@ -0,0 +1,18 @@
+#include "test/helpers/test_fixture.h"
+
+class TestSetup : public test_fixture {
+  CPPUNIT_TEST_SUITE(TestSetup);
+
+  CPPUNIT_TEST(test_config_comment_log_add_output);
+  CPPUNIT_TEST(test_config_comment_log_add_output_no_args);
+  CPPUNIT_TEST(test_config_comment_log_add_output_one_arg);
+  CPPUNIT_TEST(test_config_comment_log_add_output_too_many_args);
+
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  void test_config_comment_log_add_output();
+  void test_config_comment_log_add_output_no_args();
+  void test_config_comment_log_add_output_one_arg();
+  void test_config_comment_log_add_output_too_many_args();
+};

test/src/test_ui_download_list.cc

@@ -0,0 +1,52 @@
+#include "config.h"
+
+#include "test/src/test_ui_download_list.h"
+
+#include "ui/download_list.h"
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestUiDownloadList);
+
+void
+TestUiDownloadList::test_filter_pattern() {
+  CPPUNIT_ASSERT_EQUAL(std::string(""), ui::create_filter_pattern(""));
+  CPPUNIT_ASSERT_EQUAL(std::string(".*linux.*"), ui::create_filter_pattern("linux"));
+  CPPUNIT_ASSERT_EQUAL(std::string("^linux.*"), ui::create_filter_pattern("^linux"));
+  CPPUNIT_ASSERT_EQUAL(std::string(".*linux$"), ui::create_filter_pattern("linux$"));
+  CPPUNIT_ASSERT_EQUAL(std::string(".*linux.*"), ui::create_filter_pattern("LiNuX"));
+}
+
+void
+TestUiDownloadList::test_filter_command() {
+  torrent::Object command = ui::create_filter_command(".*linux.*");
+
+  CPPUNIT_ASSERT(command.is_dict_key());
+  CPPUNIT_ASSERT_EQUAL(std::string("match"), command.as_dict_key());
+
+  const torrent::Object::list_type& args = command.as_dict_obj().as_list();
+
+  CPPUNIT_ASSERT_EQUAL((size_t)2, args.size());
+  CPPUNIT_ASSERT(args.front().is_dict_key());
+  CPPUNIT_ASSERT_EQUAL(std::string("d.name"), args.front().as_dict_key());
+  CPPUNIT_ASSERT(args.back().is_string());
+  CPPUNIT_ASSERT_EQUAL(std::string(".*linux.*"), args.back().as_string());
+}
+
+// A pattern that closes the 'match' argument early and appends a second
+// command must stay a single inert string argument.
+void
+TestUiDownloadList::test_filter_command_does_not_inject() {
+  const std::string pattern = ui::create_filter_pattern("zzz},$d.custom1.set={pwned");
+
+  CPPUNIT_ASSERT_EQUAL(std::string(".*zzz},$d.custom1.set={pwned.*"), pattern);
+
+  torrent::Object command = ui::create_filter_command(pattern);
+
+  CPPUNIT_ASSERT(command.is_dict_key());
+  CPPUNIT_ASSERT_EQUAL(std::string("match"), command.as_dict_key());
+
+  const torrent::Object::list_type& args = command.as_dict_obj().as_list();
+
+  CPPUNIT_ASSERT_EQUAL((size_t)2, args.size());
+  CPPUNIT_ASSERT(args.back().is_string());
+  CPPUNIT_ASSERT_EQUAL(pattern, args.back().as_string());
+}

test/src/test_ui_download_list.h

@@ -0,0 +1,16 @@
+#include "test/helpers/test_fixture.h"
+
+class TestUiDownloadList : public test_fixture {
+  CPPUNIT_TEST_SUITE(TestUiDownloadList);
+
+  CPPUNIT_TEST(test_filter_pattern);
+  CPPUNIT_TEST(test_filter_command);
+  CPPUNIT_TEST(test_filter_command_does_not_inject);
+
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  void test_filter_pattern();
+  void test_filter_command();
+  void test_filter_command_does_not_inject();
+};