system: Implement network files generator from ietf-interfaces
Add a systemd-networkd files network files generator according to the
data in startup/running datastore in the ietf-interfaces model.
The IETFInterfaces class appeared (to me) a little bit too complex when
the systemd-networkd config files generator was added. Therefore I have
added the generator into IETFInterfacesConfig class and the
IETFInterfaces class handles only operational data (current status of
the network). Further, we can instantiate IETFInterfacesConfig twice
with different sessions (running, startup) and keep things little bit
simpler than if we pass two types of sessions, config directories,
reload callbacks, etc.
So far, we generate a static config. The interface is always a slave to
master br0. Only the description can vary.
Change-Id: I864df44549bb4189f2bc6d412efe501c83381369
diff --git a/src/system/IETFInterfacesConfig.cpp b/src/system/IETFInterfacesConfig.cpp
new file mode 100644
index 0000000..6f060ab
--- /dev/null
+++ b/src/system/IETFInterfacesConfig.cpp
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2021 CESNET, https://photonics.cesnet.cz/
+ *
+ * Written by Tomáš Pecka <tomas.pecka@cesnet.cz>
+ *
+ */
+
+#include <numeric>
+#include "IETFInterfacesConfig.h"
+#include "utils/io.h"
+#include "utils/libyang.h"
+#include "utils/log.h"
+#include "utils/sysrepo.h"
+
+using namespace std::string_literals;
+
+namespace {
+
+const auto CZECHLIGHT_NETWORK_MODULE_NAME = "czechlight-network"s;
+const auto IETF_IP_MODULE_NAME = "ietf-ip"s;
+const auto IETF_INTERFACES_MODULE_NAME = "ietf-interfaces"s;
+const auto IETF_ROUTING_MODULE_NAME = "ietf-routing"s;
+const auto IETF_IPV4_UNICAST_ROUTING_MODULE_NAME = "ietf-ipv4-unicast-routing";
+const auto IETF_IPV6_UNICAST_ROUTING_MODULE_NAME = "ietf-ipv6-unicast-routing";
+const auto IETF_INTERFACES = "/"s + IETF_INTERFACES_MODULE_NAME + ":interfaces"s;
+
+std::string generateNetworkConfigFile(const std::string& linkName, const std::map<std::string, std::vector<std::string>>& values)
+{
+ std::ostringstream oss;
+
+ oss << "[Match]" << std::endl;
+ oss << "Name=" << linkName << std::endl;
+
+ for (const auto& [sectionName, values] : values) {
+ oss << std::endl
+ << '[' << sectionName << ']' << std::endl;
+
+ for (const auto& confValue : values) {
+ oss << confValue << std::endl;
+ }
+ }
+
+ return oss.str();
+}
+
+}
+
+namespace velia::system {
+
+IETFInterfacesConfig::IETFInterfacesConfig(std::shared_ptr<::sysrepo::Session> srSess, std::filesystem::path configDirectory, std::vector<std::string> managedLinks, reload_cb_t reloadCallback)
+ : m_log(spdlog::get("system"))
+ , m_reloadCb(std::move(reloadCallback))
+ , m_configDirectory(std::move(configDirectory))
+ , m_managedLinks(std::move(managedLinks))
+ , m_srSession(std::move(srSess))
+ , m_srSubscribe(std::make_shared<::sysrepo::Subscribe>(m_srSession))
+{
+ utils::ensureModuleImplemented(m_srSession, IETF_INTERFACES_MODULE_NAME, "2018-02-20");
+ utils::ensureModuleImplemented(m_srSession, IETF_IP_MODULE_NAME, "2018-02-22");
+ utils::ensureModuleImplemented(m_srSession, IETF_ROUTING_MODULE_NAME, "2018-03-13");
+ utils::ensureModuleImplemented(m_srSession, IETF_IPV4_UNICAST_ROUTING_MODULE_NAME, "2018-03-13");
+ utils::ensureModuleImplemented(m_srSession, IETF_IPV6_UNICAST_ROUTING_MODULE_NAME, "2018-03-13");
+ utils::ensureModuleImplemented(m_srSession, CZECHLIGHT_NETWORK_MODULE_NAME, "2021-02-22");
+
+ m_srSubscribe->module_change_subscribe(
+ IETF_INTERFACES_MODULE_NAME.c_str(), [this](auto session, auto, auto, auto, auto) { return moduleChange(session); }, IETF_INTERFACES.c_str(), 0, SR_SUBSCR_DONE_ONLY);
+}
+
+int IETFInterfacesConfig::moduleChange(std::shared_ptr<::sysrepo::Session> session) const
+{
+ std::map<std::string, std::string> networkConfigFiles;
+
+ if (auto data = session->get_data("/ietf-interfaces:interfaces/interface"); data) {
+ auto linkEntries = data->find_path("/ietf-interfaces:interfaces/interface");
+ for (const auto& linkEntry : linkEntries->data()) {
+ std::map<std::string, std::vector<std::string>> configValues;
+
+ auto linkName = getValueAsString(getSubtree(linkEntry, "name"));
+
+ if (auto set = linkEntry->find_path("description"); set->number() != 0) {
+ configValues["Network"].push_back("Description="s + getValueAsString(set->data().front()));
+ }
+
+ configValues["Network"].push_back("Bridge=br0");
+ configValues["Network"].push_back("LLDP=true");
+ configValues["Network"].push_back("EmitLLDP=nearest-bridge");
+
+ networkConfigFiles[linkName] = generateNetworkConfigFile(linkName, configValues);
+ }
+ }
+
+ auto changedLinks = updateNetworkFiles(networkConfigFiles, m_configDirectory);
+ m_reloadCb(changedLinks);
+ return SR_ERR_OK;
+}
+
+std::vector<std::string> IETFInterfacesConfig::updateNetworkFiles(const std::map<std::string, std::string>& networkConfig, const std::filesystem::path& configDir) const
+{
+ std::vector<std::string> changedLinks;
+
+ for (const auto& link : m_managedLinks) {
+ const auto targetFile = configDir / (link + ".network");
+ const bool fileExists = std::filesystem::exists(targetFile);
+ const bool updateExists = networkConfig.contains(link);
+
+ // no configuration for link present and the file doesn't even exist -> keep default configuration
+ if (!fileExists && !updateExists) {
+ continue;
+ }
+
+ // configuration for link present, file exists, but it has the same content as the new one -> keep current configuration, no need to rewrite
+ if (fileExists && updateExists && velia::utils::readFileToString(targetFile) == networkConfig.at(link)) {
+ continue;
+ }
+
+ if (updateExists) {
+ velia::utils::safeWriteFile(targetFile, networkConfig.at(link));
+ } else { // configuration removed
+ std::filesystem::remove(targetFile);
+ }
+
+ changedLinks.push_back(link);
+ }
+
+ return changedLinks;
+}
+
+}
diff --git a/src/system/IETFInterfacesConfig.h b/src/system/IETFInterfacesConfig.h
new file mode 100644
index 0000000..6ba54c3
--- /dev/null
+++ b/src/system/IETFInterfacesConfig.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2021 CESNET, https://photonics.cesnet.cz/
+ *
+ * Written by Tomáš Pecka <tomas.pecka@cesnet.cz>
+ *
+ */
+#pragma once
+
+#include <filesystem>
+#include <sysrepo-cpp/Session.hpp>
+#include "utils/log-fwd.h"
+
+namespace velia::system {
+
+class Rtnetlink;
+
+class IETFInterfacesConfig {
+public:
+ using reload_cb_t = std::function<void(const std::vector<std::string>&)>;
+ explicit IETFInterfacesConfig(std::shared_ptr<::sysrepo::Session> srSess, std::filesystem::path configDirectory, std::vector<std::string> managedLinks, reload_cb_t reloadCallback);
+
+private:
+ velia::Log m_log;
+ reload_cb_t m_reloadCb;
+ std::filesystem::path m_configDirectory;
+ std::vector<std::string> m_managedLinks;
+ std::shared_ptr<::sysrepo::Session> m_srSession;
+ std::shared_ptr<::sysrepo::Subscribe> m_srSubscribe;
+
+ int moduleChange(std::shared_ptr<::sysrepo::Session> session) const;
+ std::vector<std::string> updateNetworkFiles(const std::map<std::string, std::string>& networkConfig, const std::filesystem::path& configDir) const;
+};
+}