C++ developer · network software · DPDK · Linux

I build network software in C++ for Linux. At T-Argos I work on a next-generation firewall (NGFW) with a DPDK data plane and a Clixon (NETCONF/RESTCONF/YANG) management plane: transceiver diagnostics, cluster session sync, DHCP relay, CPU isolation for the data plane, kernel modules and configuration migration between YANG model versions.

I also contribute upstream to the projects I use at work.

systemd (systemd-networkd, sd-dhcp-client, sd-dhcp6-client, systemd-userdbd), merged:

• networkd: follow system hostname changes in DHCP clients: the new hostname is sent to DHCPv4/DHCPv6 servers without reconfiguring the interface, the DHCPv4 lease is renewed immediately, new SendHostnameUpdates= option (fixes #36440, #36792)
• networkd: renew DHCPv6 lease on hostname change and on networkctl renew: new sd_dhcp6_client_send_renew(), the new hostname reaches DHCPv6 servers immediately, networkctl renew now renews the DHCPv6 lease too
• networkd: request DHCPv6 information again on networkctl renew: stateless DHCPv6 (Information-Request) clients refresh DNS/NTP servers on demand instead of waiting for the information refresh time (one day by default)
• networkd: show why a link is still in the configuring state: new ConfiguringReasons field in the Varlink Describe reply, shown by networkctl status (fixes #18222)
• networkd: enable IPv6 link-local addressing on WireGuard interfaces: the address generation mode reset by the WireGuard driver on every link up is restored, so routing protocols like Babel work over WireGuard out of the box (fixes #44005)
• DHCP server: do not refuse a host with a static lease whose client ID changed: the host gets its static address again instead of being ignored until the old lease expires (fixes #44120)
• DHCP server: static leases by client identifier: new ClientIdentifier=, IAID=, DUIDType= and DUIDRawData= options in [DHCPServerStaticLease], so hosts that share a hardware address (e.g. ipvlan in L2 mode) get their own static addresses
• userdbd: stop respawning workers when the worker binary is broken: new execvp_safe() that does not run a truncated binary as an empty shell script via /bin/sh; systemd-userdbd, systemd-mountfsd and systemd-nsresourced exit with an error instead of respawning workers in a loop (fixes #44280)
• tree-wide: use execvp_safe() instead of execvp(), execvpe() and execlp(): all remaining callers converted, so a truncated binary is never run as an empty shell script via /bin/sh; scripts without a shebang (e.g. via $SYSTEMD_EDITOR, $PAGER or systemd-run) are no longer executed

DPDK (lib/ethdev, app/testpmd), 18 patches merged into DPDK main for the 26.11 release (since v26.11-rc1):

• Public API to decode pluggable module EEPROM (SFP/QSFP): rte_eth_module_eeprom_parse()
• testpmd command show port <id> module_eeprom decode
• SFF-8636 per-lane LOS / LOL / Tx fault flags, SFF-8472 Rx LOS and Tx fault state
• Newer SFF compliance codes: Fibre Channel 1600/3200/6400 MBytes/sec, SAS 12G/24G
• Decoder fixes: out-of-bounds read of SFF-8636 thresholds, unaligned access, undefined behavior in SFF-8472 external calibration, Rx power calibration and rounding (the out-of-bounds read and SFF-8472 calibration fixes are backported to the 24.11 LTS branch, 24.11.9)
• In review: RFC to move the decoders into a new lib/transceiver library (to be maintained by me), module EEPROM decoding in dpdk-proc-info

All DPDK patches

Clixon (NETCONF/RESTCONF/YANG):

• Replace select() with poll() in the event loop
• cli_start_program(): run external programs (Python, Bash) from the CLI
• clixon_cli -e: exit on the first failed command: scripts run from stdin or a file (-F) stop at the first command that fails to parse or whose validate/commit fails, and exit with an error instead of applying a partial configuration
• XPath mod with a zero divisor no longer crashes (SIGFPE); xml_diff() handles an empty first tree
• In review: leafref validation fixes, NACM group lookup helpers

CLIgen: version target in Makefile, Debian packages built in CI

sdbus-c++ (C++ D-Bus library):

• sdbus::Track for tracking D-Bus peers: a wrapper over sd_bus_track, a service gets notified once its clients disconnect from the bus and releases resources held on their behalf (locks, sessions, subscriptions) (fixes #57)
• Valid C++ identifiers for argument names in the xml2cpp code generator, with compile tests for the generated bindings (fixes #550)
• Convenience API for watching property changes: IProxy::uponPropertyChange() subscribes to PropertiesChanged for a single property and delivers its typed value, or std::optional<T> for invalidated properties (fixes #500)
• Typed property value in the getPropertyAsync() callback: the reply handler may take the property value as T instead of sdbus::Variant, type mismatches are reported through the std::optional<Error> parameter (fixes #552)

Eclipse iceoryx (zero-copy IPC): ssize_t refactoring for Windows compatibility

Languages: C++17/20, C, Python, Bash

Networking: DPDK, netlink, ethtool, TCP/IP, VLAN, LACP, OSPF, VPN, SFF-8472/8636 transceivers, MikroTik (MTCNA), Cisco, Huawei

Management plane: NETCONF, RESTCONF, YANG, Clixon, CLIgen, D-Bus

Linux: kernel modules, io_uring, POSIX, systemd

Libraries: Boost.Asio, nlohmann/json, spdlog, fmt, sdbus-c++

Tools: CMake, GoogleTest, GitLab CI, Docker, Ansible, gdb, perf, Valgrind, tcpdump, Wireshark

• Email: roma55592@yandex.ru
• Telegram: @KhromenokRoman