From 98e20e5e13d2811898921f999288be7151a11954 Mon Sep 17 00:00:00 2001 From: Quentin Deslandes Date: Tue, 26 Dec 2023 14:07:42 +0100 Subject: [PATCH] bpfilter: remove bpfilter bpfilter was supposed to convert iptables filtering rules into BPF programs on the fly, from the kernel, through a usermode helper. The base code for the UMH was introduced in 2018, and couple of attempts (2, 3) tried to introduce the BPF program generate features but were abandoned. bpfilter now sits in a kernel tree unused and unusable, occasionally causing confusion amongst Linux users (4, 5). As bpfilter is now developed in a dedicated repository on GitHub (6), it was suggested a couple of times this year (LSFMM/BPF 2023, LPC 2023) to remove the deprecated kernel part of the project. This is the purpose of this patch. [1]: https://lore.kernel.org/lkml/20180522022230.2492505-1-ast@kernel.org/ [2]: https://lore.kernel.org/bpf/20210829183608.2297877-1-me@ubique.spb.ru/#t [3]: https://lore.kernel.org/lkml/20221224000402.476079-1-qde@naccy.de/ [4]: https://dxuuu.xyz/bpfilter.html [5]: https://github.com/linuxkit/linuxkit/pull/3904 [6]: https://github.com/facebook/bpfilter Signed-off-by: Quentin Deslandes Link: https://lore.kernel.org/r/20231226130745.465988-1-qde@naccy.de Signed-off-by: Alexei Starovoitov --- arch/loongarch/configs/loongson3_defconfig | 1 - include/linux/bpfilter.h | 24 ---- include/uapi/linux/bpfilter.h | 21 ---- net/Kconfig | 2 - net/Makefile | 1 - net/bpfilter/.gitignore | 2 - net/bpfilter/Kconfig | 23 ---- net/bpfilter/Makefile | 20 --- net/bpfilter/bpfilter_kern.c | 136 --------------------- net/bpfilter/bpfilter_umh_blob.S | 7 -- net/bpfilter/main.c | 64 ---------- net/bpfilter/msgfmt.h | 17 --- net/ipv4/Makefile | 2 - net/ipv4/bpfilter/Makefile | 2 - net/ipv4/bpfilter/sockopt.c | 71 ----------- net/ipv4/ip_sockglue.c | 12 -- tools/bpf/bpftool/feature.c | 4 - tools/testing/selftests/bpf/config.aarch64 | 1 - tools/testing/selftests/bpf/config.s390x | 1 - tools/testing/selftests/bpf/config.x86_64 | 1 - tools/testing/selftests/hid/config | 1 - 21 files changed, 413 deletions(-) delete mode 100644 include/linux/bpfilter.h delete mode 100644 include/uapi/linux/bpfilter.h delete mode 100644 net/bpfilter/.gitignore delete mode 100644 net/bpfilter/Kconfig delete mode 100644 net/bpfilter/Makefile delete mode 100644 net/bpfilter/bpfilter_kern.c delete mode 100644 net/bpfilter/bpfilter_umh_blob.S delete mode 100644 net/bpfilter/main.c delete mode 100644 net/bpfilter/msgfmt.h delete mode 100644 net/ipv4/bpfilter/Makefile delete mode 100644 net/ipv4/bpfilter/sockopt.c diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index 9c333d133c30..60e331af9839 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -276,7 +276,6 @@ CONFIG_BRIDGE_EBT_T_NAT=m CONFIG_BRIDGE_EBT_ARP=m CONFIG_BRIDGE_EBT_IP=m CONFIG_BRIDGE_EBT_IP6=m -CONFIG_BPFILTER=y CONFIG_IP_SCTP=m CONFIG_RDS=y CONFIG_L2TP=m diff --git a/include/linux/bpfilter.h b/include/linux/bpfilter.h deleted file mode 100644 index 736ded4905e0..000000000000 --- a/include/linux/bpfilter.h +++ /dev/null @@ -1,24 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _LINUX_BPFILTER_H -#define _LINUX_BPFILTER_H - -#include -#include -#include - -struct sock; -int bpfilter_ip_set_sockopt(struct sock *sk, int optname, sockptr_t optval, - unsigned int optlen); -int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, - int __user *optlen); - -struct bpfilter_umh_ops { - struct umd_info info; - /* since ip_getsockopt() can run in parallel, serialize access to umh */ - struct mutex lock; - int (*sockopt)(struct sock *sk, int optname, sockptr_t optval, - unsigned int optlen, bool is_set); - int (*start)(void); -}; -extern struct bpfilter_umh_ops bpfilter_ops; -#endif diff --git a/include/uapi/linux/bpfilter.h b/include/uapi/linux/bpfilter.h deleted file mode 100644 index cbc1f5813f50..000000000000 --- a/include/uapi/linux/bpfilter.h +++ /dev/null @@ -1,21 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ -#ifndef _UAPI_LINUX_BPFILTER_H -#define _UAPI_LINUX_BPFILTER_H - -#include - -enum { - BPFILTER_IPT_SO_SET_REPLACE = 64, - BPFILTER_IPT_SO_SET_ADD_COUNTERS = 65, - BPFILTER_IPT_SET_MAX, -}; - -enum { - BPFILTER_IPT_SO_GET_INFO = 64, - BPFILTER_IPT_SO_GET_ENTRIES = 65, - BPFILTER_IPT_SO_GET_REVISION_MATCH = 66, - BPFILTER_IPT_SO_GET_REVISION_TARGET = 67, - BPFILTER_IPT_GET_MAX, -}; - -#endif /* _UAPI_LINUX_BPFILTER_H */ diff --git a/net/Kconfig b/net/Kconfig index 3ec6bc98fa05..4adc47d0c9c2 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -233,8 +233,6 @@ source "net/bridge/netfilter/Kconfig" endif -source "net/bpfilter/Kconfig" - source "net/dccp/Kconfig" source "net/sctp/Kconfig" source "net/rds/Kconfig" diff --git a/net/Makefile b/net/Makefile index 4c4dc535453d..b06b5539e7a6 100644 --- a/net/Makefile +++ b/net/Makefile @@ -19,7 +19,6 @@ obj-$(CONFIG_TLS) += tls/ obj-$(CONFIG_XFRM) += xfrm/ obj-$(CONFIG_UNIX_SCM) += unix/ obj-y += ipv6/ -obj-$(CONFIG_BPFILTER) += bpfilter/ obj-$(CONFIG_PACKET) += packet/ obj-$(CONFIG_NET_KEY) += key/ obj-$(CONFIG_BRIDGE) += bridge/ diff --git a/net/bpfilter/.gitignore b/net/bpfilter/.gitignore deleted file mode 100644 index f34e85ee8204..000000000000 --- a/net/bpfilter/.gitignore +++ /dev/null @@ -1,2 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0-only -bpfilter_umh diff --git a/net/bpfilter/Kconfig b/net/bpfilter/Kconfig deleted file mode 100644 index 3d4a21462458..000000000000 --- a/net/bpfilter/Kconfig +++ /dev/null @@ -1,23 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0-only -menuconfig BPFILTER - bool "BPF based packet filtering framework (BPFILTER)" - depends on BPF && INET - select USERMODE_DRIVER - help - This builds experimental bpfilter framework that is aiming to - provide netfilter compatible functionality via BPF - -if BPFILTER -config BPFILTER_UMH - tristate "bpfilter kernel module with user mode helper" - depends on CC_CAN_LINK - depends on m || CC_CAN_LINK_STATIC - default m - help - This builds bpfilter kernel module with embedded user mode helper - - Note: To compile this as built-in, your toolchain must support - building static binaries, since rootfs isn't mounted at the time - when __init functions are called and do_execv won't be able to find - the elf interpreter. -endif diff --git a/net/bpfilter/Makefile b/net/bpfilter/Makefile deleted file mode 100644 index cdac82b8c53a..000000000000 --- a/net/bpfilter/Makefile +++ /dev/null @@ -1,20 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0 -# -# Makefile for the Linux BPFILTER layer. -# - -userprogs := bpfilter_umh -bpfilter_umh-objs := main.o -userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi - -ifeq ($(CONFIG_BPFILTER_UMH), y) -# builtin bpfilter_umh should be linked with -static -# since rootfs isn't mounted at the time of __init -# function is called and do_execv won't find elf interpreter -userldflags += -static -endif - -$(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh - -obj-$(CONFIG_BPFILTER_UMH) += bpfilter.o -bpfilter-objs += bpfilter_kern.o bpfilter_umh_blob.o diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c deleted file mode 100644 index 97e129e3f31c..000000000000 --- a/net/bpfilter/bpfilter_kern.c +++ /dev/null @@ -1,136 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#include -#include -#include -#include -#include -#include -#include -#include -#include "msgfmt.h" - -extern char bpfilter_umh_start; -extern char bpfilter_umh_end; - -static void shutdown_umh(void) -{ - struct umd_info *info = &bpfilter_ops.info; - struct pid *tgid = info->tgid; - - if (tgid) { - kill_pid(tgid, SIGKILL, 1); - wait_event(tgid->wait_pidfd, thread_group_exited(tgid)); - umd_cleanup_helper(info); - } -} - -static void __stop_umh(void) -{ - if (IS_ENABLED(CONFIG_INET)) - shutdown_umh(); -} - -static int bpfilter_send_req(struct mbox_request *req) -{ - struct mbox_reply reply; - loff_t pos = 0; - ssize_t n; - - if (!bpfilter_ops.info.tgid) - return -EFAULT; - pos = 0; - n = kernel_write(bpfilter_ops.info.pipe_to_umh, req, sizeof(*req), - &pos); - if (n != sizeof(*req)) { - pr_err("write fail %zd\n", n); - goto stop; - } - pos = 0; - n = kernel_read(bpfilter_ops.info.pipe_from_umh, &reply, sizeof(reply), - &pos); - if (n != sizeof(reply)) { - pr_err("read fail %zd\n", n); - goto stop; - } - return reply.status; -stop: - __stop_umh(); - return -EFAULT; -} - -static int bpfilter_process_sockopt(struct sock *sk, int optname, - sockptr_t optval, unsigned int optlen, - bool is_set) -{ - struct mbox_request req = { - .is_set = is_set, - .pid = current->pid, - .cmd = optname, - .addr = (uintptr_t)optval.user, - .len = optlen, - }; - if (sockptr_is_kernel(optval)) { - pr_err("kernel access not supported\n"); - return -EFAULT; - } - return bpfilter_send_req(&req); -} - -static int start_umh(void) -{ - struct mbox_request req = { .pid = current->pid }; - int err; - - /* fork usermode process */ - err = fork_usermode_driver(&bpfilter_ops.info); - if (err) - return err; - pr_info("Loaded bpfilter_umh pid %d\n", pid_nr(bpfilter_ops.info.tgid)); - - /* health check that usermode process started correctly */ - if (bpfilter_send_req(&req) != 0) { - shutdown_umh(); - return -EFAULT; - } - - return 0; -} - -static int __init load_umh(void) -{ - int err; - - err = umd_load_blob(&bpfilter_ops.info, - &bpfilter_umh_start, - &bpfilter_umh_end - &bpfilter_umh_start); - if (err) - return err; - - mutex_lock(&bpfilter_ops.lock); - err = start_umh(); - if (!err && IS_ENABLED(CONFIG_INET)) { - bpfilter_ops.sockopt = &bpfilter_process_sockopt; - bpfilter_ops.start = &start_umh; - } - mutex_unlock(&bpfilter_ops.lock); - if (err) - umd_unload_blob(&bpfilter_ops.info); - return err; -} - -static void __exit fini_umh(void) -{ - mutex_lock(&bpfilter_ops.lock); - if (IS_ENABLED(CONFIG_INET)) { - shutdown_umh(); - bpfilter_ops.start = NULL; - bpfilter_ops.sockopt = NULL; - } - mutex_unlock(&bpfilter_ops.lock); - - umd_unload_blob(&bpfilter_ops.info); -} -module_init(load_umh); -module_exit(fini_umh); -MODULE_LICENSE("GPL"); diff --git a/net/bpfilter/bpfilter_umh_blob.S b/net/bpfilter/bpfilter_umh_blob.S deleted file mode 100644 index 40311d10d2f2..000000000000 --- a/net/bpfilter/bpfilter_umh_blob.S +++ /dev/null @@ -1,7 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - .section .init.rodata, "a" - .global bpfilter_umh_start -bpfilter_umh_start: - .incbin "net/bpfilter/bpfilter_umh" - .global bpfilter_umh_end -bpfilter_umh_end: diff --git a/net/bpfilter/main.c b/net/bpfilter/main.c deleted file mode 100644 index 291a92546246..000000000000 --- a/net/bpfilter/main.c +++ /dev/null @@ -1,64 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -#define _GNU_SOURCE -#include -#include -#include -#include -#include -#include -#include "../../include/uapi/linux/bpf.h" -#include -#include "msgfmt.h" - -FILE *debug_f; - -static int handle_get_cmd(struct mbox_request *cmd) -{ - switch (cmd->cmd) { - case 0: - return 0; - default: - break; - } - return -ENOPROTOOPT; -} - -static int handle_set_cmd(struct mbox_request *cmd) -{ - return -ENOPROTOOPT; -} - -static void loop(void) -{ - while (1) { - struct mbox_request req; - struct mbox_reply reply; - int n; - - n = read(0, &req, sizeof(req)); - if (n != sizeof(req)) { - fprintf(debug_f, "invalid request %d\n", n); - return; - } - - reply.status = req.is_set ? - handle_set_cmd(&req) : - handle_get_cmd(&req); - - n = write(1, &reply, sizeof(reply)); - if (n != sizeof(reply)) { - fprintf(debug_f, "reply failed %d\n", n); - return; - } - } -} - -int main(void) -{ - debug_f = fopen("/dev/kmsg", "w"); - setvbuf(debug_f, 0, _IOLBF, 0); - fprintf(debug_f, "<5>Started bpfilter\n"); - loop(); - fclose(debug_f); - return 0; -} diff --git a/net/bpfilter/msgfmt.h b/net/bpfilter/msgfmt.h deleted file mode 100644 index 98d121c62945..000000000000 --- a/net/bpfilter/msgfmt.h +++ /dev/null @@ -1,17 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _NET_BPFILTER_MSGFMT_H -#define _NET_BPFILTER_MSGFMT_H - -struct mbox_request { - __u64 addr; - __u32 len; - __u32 is_set; - __u32 cmd; - __u32 pid; -}; - -struct mbox_reply { - __u32 status; -}; - -#endif diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile index e144a02a6a61..ec36d2ec059e 100644 --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile @@ -16,8 +16,6 @@ obj-y := route.o inetpeer.o protocol.o \ inet_fragment.o ping.o ip_tunnel_core.o gre_offload.o \ metrics.o netlink.o nexthop.o udp_tunnel_stub.o -obj-$(CONFIG_BPFILTER) += bpfilter/ - obj-$(CONFIG_NET_IP_TUNNEL) += ip_tunnel.o obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o obj-$(CONFIG_PROC_FS) += proc.o diff --git a/net/ipv4/bpfilter/Makefile b/net/ipv4/bpfilter/Makefile deleted file mode 100644 index 00af5305e05a..000000000000 --- a/net/ipv4/bpfilter/Makefile +++ /dev/null @@ -1,2 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0-only -obj-$(CONFIG_BPFILTER) += sockopt.o diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c deleted file mode 100644 index 193bcc2acccc..000000000000 --- a/net/ipv4/bpfilter/sockopt.c +++ /dev/null @@ -1,71 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -#include -#include -#include -#include -#include -#include -#include -#include -#include - -struct bpfilter_umh_ops bpfilter_ops; -EXPORT_SYMBOL_GPL(bpfilter_ops); - -static int bpfilter_mbox_request(struct sock *sk, int optname, sockptr_t optval, - unsigned int optlen, bool is_set) -{ - int err; - mutex_lock(&bpfilter_ops.lock); - if (!bpfilter_ops.sockopt) { - mutex_unlock(&bpfilter_ops.lock); - request_module("bpfilter"); - mutex_lock(&bpfilter_ops.lock); - - if (!bpfilter_ops.sockopt) { - err = -ENOPROTOOPT; - goto out; - } - } - if (bpfilter_ops.info.tgid && - thread_group_exited(bpfilter_ops.info.tgid)) - umd_cleanup_helper(&bpfilter_ops.info); - - if (!bpfilter_ops.info.tgid) { - err = bpfilter_ops.start(); - if (err) - goto out; - } - err = bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set); -out: - mutex_unlock(&bpfilter_ops.lock); - return err; -} - -int bpfilter_ip_set_sockopt(struct sock *sk, int optname, sockptr_t optval, - unsigned int optlen) -{ - return bpfilter_mbox_request(sk, optname, optval, optlen, true); -} - -int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, - int __user *optlen) -{ - int len; - - if (get_user(len, optlen)) - return -EFAULT; - - return bpfilter_mbox_request(sk, optname, USER_SOCKPTR(optval), len, - false); -} - -static int __init bpfilter_sockopt_init(void) -{ - mutex_init(&bpfilter_ops.lock); - bpfilter_ops.info.tgid = NULL; - bpfilter_ops.info.driver_name = "bpfilter_umh"; - - return 0; -} -device_initcall(bpfilter_sockopt_init); diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 66247e8b429e..7aa9dc0e6760 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -47,8 +47,6 @@ #include #include -#include - /* * SOL_IP control messages. */ @@ -1411,11 +1409,6 @@ int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, return -ENOPROTOOPT; err = do_ip_setsockopt(sk, level, optname, optval, optlen); -#if IS_ENABLED(CONFIG_BPFILTER_UMH) - if (optname >= BPFILTER_IPT_SO_SET_REPLACE && - optname < BPFILTER_IPT_SET_MAX) - err = bpfilter_ip_set_sockopt(sk, optname, optval, optlen); -#endif #ifdef CONFIG_NETFILTER /* we need to exclude all possible ENOPROTOOPTs except default case */ if (err == -ENOPROTOOPT && optname != IP_HDRINCL && @@ -1763,11 +1756,6 @@ int ip_getsockopt(struct sock *sk, int level, err = do_ip_getsockopt(sk, level, optname, USER_SOCKPTR(optval), USER_SOCKPTR(optlen)); -#if IS_ENABLED(CONFIG_BPFILTER_UMH) - if (optname >= BPFILTER_IPT_SO_GET_INFO && - optname < BPFILTER_IPT_GET_MAX) - err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen); -#endif #ifdef CONFIG_NETFILTER /* we need to exclude all possible ENOPROTOOPTs except default case */ if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS && diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c index edda4fc2c4d0..708733b0ea06 100644 --- a/tools/bpf/bpftool/feature.c +++ b/tools/bpf/bpftool/feature.c @@ -426,10 +426,6 @@ static void probe_kernel_image_config(const char *define_prefix) { "CONFIG_BPF_STREAM_PARSER", }, /* xt_bpf module for passing BPF programs to netfilter */ { "CONFIG_NETFILTER_XT_MATCH_BPF", }, - /* bpfilter back-end for iptables */ - { "CONFIG_BPFILTER", }, - /* bpftilter module with "user mode helper" */ - { "CONFIG_BPFILTER_UMH", }, /* test_bpf module for BPF tests */ { "CONFIG_TEST_BPF", }, diff --git a/tools/testing/selftests/bpf/config.aarch64 b/tools/testing/selftests/bpf/config.aarch64 index 29c8635c5722..3720b7611523 100644 --- a/tools/testing/selftests/bpf/config.aarch64 +++ b/tools/testing/selftests/bpf/config.aarch64 @@ -11,7 +11,6 @@ CONFIG_BLK_DEV_IO_TRACE=y CONFIG_BLK_DEV_RAM=y CONFIG_BLK_DEV_SD=y CONFIG_BONDING=y -CONFIG_BPFILTER=y CONFIG_BPF_JIT_ALWAYS_ON=y CONFIG_BPF_JIT_DEFAULT_ON=y CONFIG_BPF_PRELOAD_UMD=y diff --git a/tools/testing/selftests/bpf/config.s390x b/tools/testing/selftests/bpf/config.s390x index e93330382849..706931a8c2c6 100644 --- a/tools/testing/selftests/bpf/config.s390x +++ b/tools/testing/selftests/bpf/config.s390x @@ -9,7 +9,6 @@ CONFIG_BPF_JIT_ALWAYS_ON=y CONFIG_BPF_JIT_DEFAULT_ON=y CONFIG_BPF_PRELOAD=y CONFIG_BPF_PRELOAD_UMD=y -CONFIG_BPFILTER=y CONFIG_CGROUP_CPUACCT=y CONFIG_CGROUP_DEVICE=y CONFIG_CGROUP_FREEZER=y diff --git a/tools/testing/selftests/bpf/config.x86_64 b/tools/testing/selftests/bpf/config.x86_64 index b946088017f1..5680befae8c6 100644 --- a/tools/testing/selftests/bpf/config.x86_64 +++ b/tools/testing/selftests/bpf/config.x86_64 @@ -19,7 +19,6 @@ CONFIG_BOOTTIME_TRACING=y CONFIG_BPF_JIT_ALWAYS_ON=y CONFIG_BPF_PRELOAD=y CONFIG_BPF_PRELOAD_UMD=y -CONFIG_BPFILTER=y CONFIG_BSD_DISKLABEL=y CONFIG_BSD_PROCESS_ACCT=y CONFIG_CFS_BANDWIDTH=y diff --git a/tools/testing/selftests/hid/config b/tools/testing/selftests/hid/config index 4f425178b56f..1758b055f295 100644 --- a/tools/testing/selftests/hid/config +++ b/tools/testing/selftests/hid/config @@ -1,5 +1,4 @@ CONFIG_BPF_EVENTS=y -CONFIG_BPFILTER=y CONFIG_BPF_JIT_ALWAYS_ON=y CONFIG_BPF_JIT=y CONFIG_BPF_KPROBE_OVERRIDE=y