v2.0

2026.10 F-Stack v2.0

1. F-Stack lib:

• Support single-process multi-thread mode (thread_mode=1).
• Add primary_slim mode, the primary keeps no rx/tx queue. Ref #1078.
• Add graceful_reload for nginx, HUP reload is lossless.
• Support lossless binary upgrade with USR2 under graceful_reload=1.
• Dispatch UDP flows across graceful reload.
• Add drain_ring_size, reload_heartbeat_timeout_ms and reload_udp_idle_ms in config.ini.
• Add idle_loop_interval in config.ini.
• Add ff_regist_idle_callback() and ff_unregist_idle_callback().
• Add LRO offload with software fallback, and improve TSO for IPv6.
• Support runtime MTU change and jumbo frames.
• Add mbuf water-level backpressure. Thanks @Sai-Raveendra-Kandregula
• Add fine-grained TX checksum offload control. Thanks @vincentmli
• Add extra_eal_args config option. Thanks @whatmatrix
• Add zero-copy receive ff_zc_recv(), and rework ff_zc_send() without the magic sentinel.
• Add FF_KERNEL_COEXIST for kernel stack coexistence.
• Optimize ff_rss_check() with rte_thash_adjust_tuple(), and support IPv6.
• Run RSS aware port selection for IPv6 outbound connects.
• Add ff_regist_packet_dispatcher_context(). @jinliu777
• Support nanosecond timestamp precision in pcap dump.
• Recognize IPv6 L4 checksum offload flags in ff_mbuf_tx_offload().
• Fix the BBR large-file hang.
• Add a cmocka based unit test framework.

1. adapter

• Add lock-free ring IPC for LD_PRELOAD (FF_USE_RING_IPC).
• Map Linux SO_TIMESTAMP to FreeBSD. @tarun-t
• Propagate the DPDK mbuf RX timestamp to the FreeBSD mbuf. @tarun-t
• Fix the ioctl conflicting types compile error on older glibc.
• Add an addrlen check in ff_hook_bind() (#1068).

1. FreeBSD

• Upgrade to FreeBSD-releng-15.0.
• Fix TCP timers never being armed (callout_when() was an empty stub).
• Fix EVFILT_TIMER precision of kqueue. Thanks @vanlink

1. ff tools

• Let the F-Stack tools find a stack by themselves (#419). @alberthaolihai
• Let ff_top and ff_traffic follow a graceful reload.
• Support cross-generation addressing with -p and -g.
• Fix IPFW crash when the rule list is large. Thanks @chocosnat
• Fix start.sh lcore_mask parsing to ignore commented lines.
• Fix ff tools build error with gcc-15.2.0 in ubuntu-26.04.

1. DPDK:

• Upgrade to DPDK-24.11.8(LTS).
• Fix the secondary process resetting the NIC (#860).
• Fix an infinite loop when a DPDK secondary process restarts. @jinliu777
• Fix the vmxnet3 rss_key_len in RSS mode. @WK-Tseng
• Fix build with GCC 15 and DPDK 25.11. @tarun-t
• Bump black, cryptography and pynacl in /dpdk/dts. @dependabot[bot]

1. APP

• Nginx: lossless reload (HUP) and binary upgrade (USR2).
• Nginx: dispatch UDP flows across reload.
• Nginx: fix a SIGSEGV in stream udp proxying.
• Nginx: add a reverse-proxy example with buffer settings.
• Redis: fix the build when the jemalloc configure script is missing (#802).

1. example

• Make helloworld thread-safe for thread_mode=1.
• Add a UDP echo server example (#1063).

1. doc:

• Add three-layer architecture docs and knowledge graph.
• Add F-Stack 2.0 preview blogs in Chinese and English.
• Update the nginx guide for graceful reload.
• Document the executable bits and symlink loss when the tree is copied from Windows.

v1.21.7(LTS)

2026.10 F-Stack v1.21.7(LTS)

1. F-Stack lib:

• Port kernel-stack coexistence from release/2.0.
• Port LRO support and TSO improvements from branch of dev.
• Fix software LRO crash on flush by setting mbuf rcvif.
• Port MTU change (jumbo frame) support from branch of dev.
• Port IPv6 RSS check static-table support from branch of dev.
• Run RSS aware port selection for IPv6 outbound connects.
• Support nanosecond timestamp precision in pcap dump.
• Add mbuf water-level backpressure for high connection rate scenarios. Thanks @Sai-Raveendra-Kandregula
• Add fine-grained TX checksum offload control in config.ini. Thanks @vincentmli
• Add extra_eal_args config option for generic DPDK EAL argument passthrough. Thanks @whatmatrix
• Add ff_accept4 API with LINUX_SOCK_CLOEXEC/LINUX_SOCK_NONBLOCK support. @liujinhui-job
• Add an API ff_regist_packet_dispatcher_context that allows to pass more context to callback. @jinliu777
• Fix a build error on DPDK 19.11 by using PKT_RX_VLAN_STRIPPED.

1. FreeBSD:

• Port IPv6 RSS check static-table support from branch of dev.
• Fix EVFILT_TIMER precision of kqueue. Thanks @vanlink

1. ff tools:

• Fix IPFW crash when the rule list is large. Thanks @chocosnat
• Fix start.sh lcore_mask parsing to ignore commented lines.

1. APP:

• Nginx: fix a SIGSEGV in stream udp proxying, upstream connections have no c->listening.

1. doc:

• Replace dpdk-setup.sh with 'make config T=x86_64-native-linuxapp-gcc' and point FF_DPDK/insmod paths to dpdk/build in docs and Makefiles.
• Document how to restore the executable bits and the symlink lost when sources are copied from Windows.

1.25

2025.11 F-Stack v1.25(LTS)

1. F-Stack lib:

• Support CI. @shanakaprageeth
• set the IP-type flag for tx_csum_l4 offload. @zcjie1
• m_gethdr will call m_pkthdr_init also, so there is no need to initialize it again. @liujinhui-job
• add tcp/udp loopback support, we can send packet through lo dev. @liujinhui-job
• fix dev_info.hash_key_size is 0 init_port_start failed. @liujinhui-job
• Add support for custom install prefix. @Clcanny
• Disable RSS if hardware does not support it. @Clcanny
• add __recv_chk/__read_chk/__recvfrom_chk. @liujinhui-job
• Change ff config pci whitelist to allow. @liujinhui-job
• Add inner IP and port-based flow steering capabilities for the IPIP protocol.(Authors: Zhiwen Wang @hirowang1, Huiqin Zhang).
• ff_ipfw support ip_fw_pmod and tcpmod for tcp-setmss.
• f-stack supports the socket options IP_TRANSPARENT and IPV6_TRANSPARENT. Nginx does not require additional checks, and the translation for IPV6_PKTINFO has been added. @wenchengji159357
• Modify usleep to rte_delay_us_sleep.
• Remove some useless code of kni.
• ff_traffic support rx_dropped and tx_dropped.
• fix ff toos issue for mlx5 drivers.
• Support bind no port like linux's IP_BIND_ADDRESS_NO_PORT.
• Add the feature fo ff_rss_check table to improve the performance of ff_rss_check(). See https://github.com/F-Stack/f-stack/wiki/%E2%80%8B%E2%80%8BF%E2%80%90Stack-ff_rss_check()-Optimization-Introduction%E2%80%8B
• Added the -Wextra compilation option and fixed compilation errors.
• Add ff_log mod, that encapsulates some interfaces of the rte_log module.
• Remove the code for rte_kni.ko, only retain virtio.
• Add some cleanup action, however, it is incomplete.

1. adapter

• fix compile syscall directory compile issue. @liujinhui-job
• add ld_preload mode fcntl linux flags convert to freebsd. @liujinhui-job
• add epoll polling mode, improve latency performance in RTT mode. @liujinhui-job
• ff_hook_recvfrom sh_fromlen not init, ff_sys_recvfrom will return -1. @liujinhui-job
• add fork support, like linux kernel, every process has one freebsd struct thread. @liujinhui-job
• Add select interface support. @liujinhui-job
• add accept4 support, and LINUX_SOCK_CLOEXEC/LINUX_SOCK_NONBLOCK support for ff_socket. @liujinhui-job

1. FreeBSD

• Add the feature fo ff_rss_check table to improve the performance of ff_rss_check(). See https://github.com/F-Stack/f-stack/wiki/%E2%80%8B%E2%80%8BF%E2%80%90Stack-ff_rss_check()-Optimization-Introduction%E2%80%8B

1. ff toos

• update tools/compat/include/sys/*.h.
• ff_traffic support rx_dropped and tx_dropped.

1. DPDK

• DPDK: Upgrade to 23.11.5.
• Build fix : Copy missing igb_uio.c to build dir. @richqubit
• Modify real_if_indextoname return value and type. @GiannisLi

1. APP

• Nginx: Upgrad to Nginx-1.28.0. @jinliu777
• Nginx: f-stack supports the socket options IP_TRANSPARENT and IPV6_TRANSPARENT. Nginx does not require additional checks, and the translation for IPV6_PKTINFO has been added. @wenchengji159357
• Redis: Fix Redis Lua security vulnerabilities (CVE-2024-31449, CVE-2025-29844, CVE-2025-46817, CVE-2025-46819). @KIMDONGYEON00

1. doc

• Add wiki and deepwiki link in README.
• Remove the relevant content for rte_kni.ko from the documentation.

1.21.6

2025.11 F-Stack v1.21.6(LTS)

1. F-Stack lib:

• Support bind no port like linux's IP_BIND_ADDRESS_NO_PORT.
• Add inner IP and port-based flow steering capabilities for the IPIP protocol.(Authors: Zhiwen Wang @hirowang1, Huiqin Zhang).
• Modify usleep to rte_delay_us_sleep.
• Add viritio support for kni.
• Build netgraph and ipfw by default.
• Disable RSS if hardware does not support it. @Clcanny
• ff_traffic support rx_dropped and tx_dropped.
• Added the -Wextra compilation option and fixed compilation errors.
• Add ff_log mod, that encapsulates some interfaces of the rte_log module.
• set the IP-type flag for tx_csum_l4 offload. @zcjie1
• Add ff_stop_run to stop the poll loop. @renzibei
• Add some cleanup action, however, it is incomplete.
• Add the feature fo ff_rss_check table to improve the performance of ff_rss_check(). See https://github.com/F-Stack/f-stack/wiki/%E2%80%8B%E2%80%8BF%E2%80%90Stack-ff_rss_check()-Optimization-Introduction%E2%80%8B

1. FreeBSD

• Add the feature fo ff_rss_check table to improve the performance of ff_rss_check(). See https://github.com/F-Stack/f-stack/wiki/%E2%80%8B%E2%80%8BF%E2%80%90Stack-ff_rss_check()-Optimization-Introduction%E2%80%8B

1. ff toos

• ff_traffic support rx_dropped and tx_dropped.

1. DPDK

• Modify real_if_indextoname return value and type. @GiannisLi

1. APP

• Nginx: Adapt nginx-1.28.0 to f-stack. @jinliu777

v.1.21.5

2024.10 F-Stack v1.21.5(LTS)

1. F-Stack lib:

• Modify ff_port_cfg.port_id's type from uint8_t to unint16_t.
• Modify INI_MAX_LINE from 200 to 2048 in lib/ff_ini_parser.h.
• IPv6 addr and vaddr set autoconf by default.
• Modify IPv4 vip addrs' broadaddr from x.x.x.255 to x.x.x.x, same as vip addr, because vips' netmask only support 255.255.255.255 now.
• Add APi ff_dpdk_raw_packet_send to suppoort RAW packet send direty with DPDK by user APP not via socket.
• Support automatic configuration of vlan and vlan ip, routing and the simplest policy routing.
• Use soclose() instead of sofree() when initializing the configuration stack IP.
• Support KNI ratelimit, default disable.
• The msghdr.msg_iov->iov_base and msghdr.msg_iov->iov_len of ff_sendmsg() and ff_recvmsg() compatible with the Linux.

1. FreeBSD

• Fix issue in Freebsd when building with GCC 14.1.0. @bjosv

1. ff toos

• Fix ff tools build error with gcc-13.2.0.

1. DPDK

• Fix some build errors of dpdk-19.11.14 with gcc-13.2.0.

1. APP

• Nginx: Nginx's stream support transparent.

1. doc

• Update ff tools README.md, use ff_netstat -rnW to display wider device name.
• Fix a typo in doc/F-Stack_Nginx_APP_Guide.md: "kernel_network_stack" -> "proxy_kernel_network_stack".

1.24

2024.10 F-Stack v1.24

1. F-Stack lib, Sync some features from branch of dev:

• Restore vEth0 to veth0 now.
• Add kni type argument in config.ini and FF_KNI_KNI in lib/Makefile to set exception path type.
• FF_FLOW_ISOLATE support DPDK-22.11.
• Add net.add_addr_allfibs=1 in config.ini.
• gettimeofday automatically compatible with different glibc versions.
• Add an API ff_get_traffic to get traffic for QoS or other.
• Add ff_stop_run to stop the poll loop. @renzibei
• Add POSIX Like functions for pthread_create and pthread_join. @radu Nichita
• Fix pthread issue. @vitaly Pavlov
• Fix a build error with gcc-4.8.5.
• Modify ff_port_cfg.port_id's type from uint8_t to unint16_t.
• Modify INI_MAX_LINE from 200 to 2048 in lib/ff_ini_parser.h.
• IPv6 addr and vaddr set autoconf by default.
• Modify IPv4 vip addrs' broadaddr from x.x.x.255 to x.x.x.x, same as vip addr, because vips' netmask only support 255.255.255.255 now.
• Add APi ff_dpdk_raw_packet_send to suppoort RAW packet send direty with DPDK by user APP not via socket.
• Support automatic configuration of vlan and vlan ip, routing and the simplest policy routing.
• Use soclose() instead of sofree() when initializing the configuration stack IP.
• Support KNI ratelimit, default disable.
• The msghdr.msg_iov->iov_base and msghdr.msg_iov->iov_len of ff_sendmsg() and ff_recvmsg() compatible with the Linux.

1. FreeBSD

• Add atomic_fcmpset_int32.
• Fix some build errors of freebsd with gcc-12.2.0.
• For f-stack to support QAT accelerator cards. @wenchengJi.
• Fix some build errors of freebsd with gcc-13.2.0.
• Fix issue in Freebsd when building with GCC 14.1.0. @bjosv

1. ff toos

• Fix ff tools build error with gcc-13.2.0.
• Fix netstat tool compilation on linux. Support mawk of ubuntu. @taras

1. DPDK

• DPDK: Upgrade to 22.11.6.
• Fix a compilation warning of drivers mlx5.
• Bump black from 22.10.0 to 24.3.0 in /dpdk/dts. @dependabot[bot]
• kni_net.c compatible with -Wstringop-overflow with different gcc versions.

1. APP

• Nginx: gettimeofday automatically compatible with different glibc versions.
• Nginx: Nginx's stream support transparent.

1. adapter

• syscall: Fix cplen calculation errors in ff_hook_syscall.c. @zhaozihanzzh
• syscall: Close kernel epoll fd in ff_hook_close when using FF_KERNEL_EVENT. @zhaozihanzzh

1. doc

• modify doc that re-enable kni now, to remove kni later.
• Modify nginx-1.16.1 to nginx-1.25.2 in docs.
• Remove doc/F-Stack_Binary_Release_Quick_Start.md.
• chore: update freebsd version in readme. @Jamlee
• Update ff tools README.md, use ff_netstat -rnW to display wider device name.
• Update F-Stack_Quick_Start_Guide.md, add a cmd. @万能的翔王大人
• Fix a typo in doc/F-Stack_Nginx_APP_Guide.md: "kernel_network_stack" -> "proxy_kernel_network_stack".
• Disable build driver crypto/openssl for Redhat/Centos 7.x.

v1.21.4(LTS)

2023.10 F-Stack v1.21.4(LTS)

1. F-Stack lib:

• Add vlan_filter argument in config.ini for RSS with vlan.
  • Set Rx VLAN filter, and then the dirvier(such as MLX5) will set FLOW RSS to enable L3/L4 RSS below vlan hdr. This action won't need after DPDK-20.11.
• Fix Compile Error with gcc 12.2.0.
• gettimeofday automatically compatible with different glibc versions.
• Add an API ff_get_traffic to get traffic for QoS or other.

2. ff tools:

• Fix Compile Error with gcc 12.2.0.

3. APP:

• gettimeofday automatically compatible with different glibc versions.

v1.23

2023.09 F-Stack v1.23

1. F-Stack lib, Sync some features from branch of dev:

• Added FDIR using general flow rules. @guhaoyu2005.
• Added more clear error message in case of failed config read. @d06alexandrov.
• vlan_strip support kni.
• Removed deleted sources from Makefile. @d06alexandrov.
• make it compilable under O2 optimization, pass gcc check. @renzibei.
• enable -O2 by default. Ref #711 #721.
• Fix #702 F-stack rack and BBR both causes PCB memory leak.
• tcp: Missing mfree in rack and bbr.
• when nginx use setsockopt ON_LINGER, the seq number of the RST packet is error. @wenchengji159357.
• While use bbr, the hz should be set to 1000000, match the bintime and timer of F-Stack. Ref #701 #702.
• Redis can listen IPv6 address.
• Fix Compile Error with gcc 11.3.0(in Ubuntu 22.04). Close #736.
• Fixed #705. While Adding -DNDEBUG flag will cause the helloworld example.
• Add some description of ff_socket() and ff_write(). Ref #709.
• Modify pci_whitelist to allow that from DPDK 20.11. Close #745.
• fix that vtoslab doesn't return the correct slab. @ZhuTian.
• When entering the softclock function for the first time,ticks is 2147423648,cc_softticks is 0. @wenchengji159357.
• Add adapter for LD_PRELOAD. EXPERIMENTAL.
• fix cmsg for sendmsg. @sarosh.
• Fixed an issue that before C99 mode..
• Fiexd some build errors of ipfw on ubuntu 22.04 (kernel:5.19.0-1025, gcc:11.4.0),
• fix some issue of ff_sendmsg and ff_recvmsg.
• Support LINUX_IP_TRANSPARENT and LINUX_IPV6_TRANSPARENT to IP_BINDANY and IPV6_BINDANY in lib/ff_syscall_wrapper.c.

2. DPDK:

• DPDK: Upgrade to 21.11.5.
• Fix I40E_DEV_ID_10G_BASE_T_X722 issue.
• Update igb_uio, sync from git://dpdk.org/dpdk-kmods.

3. APP:

• Nginx: Upgrade to Nginx-1.25.2 to support HTTP3. EXPERIMENTAL.
• Add adapter for LD_PRELOAD. EXPERIMENTAL.
• move /app/micro_thread to adapter/micro_thread.
• Fix netmask in nginx conf. @jiegec.
• Fiexd some build errors of micro_thread on ubuntu 22.04 (kernel:5.19.0-1025, gcc:11.4.0),

4. example:

• Set non blocking in example/main.c. Ref #709.
• Add helloworld_stack_epoll、 main_stack_epoll_pipeline and kevent for LD_PRELOAD demo.
• Fiexd some build errors of example on ubuntu 22.04 (kernel:5.19.0-1025, gcc:11.4.0).

v1.22.1

2023.09 F-Stack v1.22.1

1. F-Stack lib:

• Fix #702 F-stack rack and BBR both causes PCB memory leak.
• While use bbr, the hz should be set to 1000000, match the bintime and timer of F-Stack. Ref #701 #702
• Modify pci_whitelist to allow that from DPDK 20.11. Close #745.

2. DPDK:

• Upgrade to DPDK-20.11.9(LTS).

v1.21.3

2023.09 F-Stack v1.21.3(LTS)

1. F-Stack lib, Sync some features from branch of dev:

• vlan_strip support kni.
• Fix Compile Error with gcc 11.3.0(in Ubuntu 22.04).
• Added F-Stack FreeBSD support. see 9f7a142 .
• Enable INET6 by default in helloworld. see 51c91ab .
• Added FDIR support. see 4854315 .
• To avoid compiling errors when gcc version >= 10. see 6daadb0 .
• Modify struct linux_sockaddr same to struct sockaddr in linux. see d96a9d1 .
• Sync some modified of ff_config.c, inclue set dpdk log level, Avoid memory leaks, suppor vip_addr and vip_addr6, etc. see git log lib/ff_config.c in branch of dev.
• Sync some modified of ff_syscall_wrapper.c, include ff_sendmsg, ff_recvmsg, ip6_opt_convert, etc. see git log lib/ff_syscall_wrapper.c in branch of dev.
• The CPU usage of packet_dispatcher() is modified to usr. see 0508c8b .
• If process_dispatch_ring() has data packet to be processed and it is considered non-idle state. see 81dd6c7 .
• Fix a plurality of packets may not statistics in ff_traffic.rx_packets and ff_traffic.rx_bytes. see 0b4a084 .
• Added FF_IPSEC=1 in lib/Makefile, disable by default.
• Some other modified.

2. DPDK:

• DPDK: Upgrade to 19.11.14(LTS).

3. APP:

• Fiexd some build errors of micro_thread on ubuntu 22.04.