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[34.74.119.39]) by smtp.googlemail.com with ESMTPSA id e8sm245374uar.11.2020.08.12.09.33.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Aug 2020 09:33:14 -0700 (PDT) From: Leah Rumancik To: bpf@vger.kernel.org, linux-block@vger.kernel.org Cc: leah.rumancik@gmail.com, orbekk@google.com, harshads@google.com, jasiu@google.com, saranyamohan@google.com, tytso@google.com, bvanassche@google.com Subject: [RFC PATCH 1/4] bpf: add new prog_type BPF_PROG_TYPE_IO_FILTER Date: Wed, 12 Aug 2020 16:33:02 +0000 Message-Id: <20200812163305.545447-2-leah.rumancik@gmail.com> X-Mailer: git-send-email 2.28.0.236.gb10cc79966-goog In-Reply-To: <20200812163305.545447-1-leah.rumancik@gmail.com> References: <20200812163305.545447-1-leah.rumancik@gmail.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Introducing a new program type BPF_PROG_TYPE_IO_FILTER and a new attach type BPF_BIO_SUBMIT. This program type is intended to help filter and monitor IO requests. Co-developed-by: Saranya Muruganandam Signed-off-by: Saranya Muruganandam Signed-off-by: Kjetil Ørbekk Signed-off-by: Harshad Shirwadkar Signed-off-by: Leah Rumancik --- block/Makefile | 1 + block/blk-bpf-io-filter.c | 209 ++++++++++++++++++ block/blk-bpf-io-filter.h | 16 ++ block/blk-core.c | 6 + block/genhd.c | 3 + include/linux/bpf_io_filter.h | 23 ++ include/linux/bpf_types.h | 4 + include/linux/genhd.h | 4 + include/uapi/linux/bpf.h | 11 + init/Kconfig | 8 + kernel/bpf/syscall.c | 9 + kernel/bpf/verifier.c | 1 + tools/bpf/bpftool/feature.c | 2 + tools/bpf/bpftool/main.h | 2 + tools/include/uapi/linux/bpf.h | 11 + tools/lib/bpf/libbpf.c | 2 + tools/lib/bpf/libbpf_probes.c | 1 + .../selftests/bpf/prog_tests/section_names.c | 5 + 18 files changed, 318 insertions(+) create mode 100644 block/blk-bpf-io-filter.c create mode 100644 block/blk-bpf-io-filter.h create mode 100644 include/linux/bpf_io_filter.h diff --git a/block/Makefile b/block/Makefile index 78719169fb2a..358ace8002cd 100644 --- a/block/Makefile +++ b/block/Makefile @@ -38,3 +38,4 @@ obj-$(CONFIG_BLK_SED_OPAL) += sed-opal.o obj-$(CONFIG_BLK_PM) += blk-pm.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION) += keyslot-manager.o blk-crypto.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) += blk-crypto-fallback.o +obj-$(CONFIG_BPF_IO_FILTER) += blk-bpf-io-filter.o diff --git a/block/blk-bpf-io-filter.c b/block/blk-bpf-io-filter.c new file mode 100644 index 000000000000..453d6b156bd2 --- /dev/null +++ b/block/blk-bpf-io-filter.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "blk-bpf-io-filter.h" + +#define io_filter_rcu_dereference_progs(disk) \ + rcu_dereference_protected(disk->progs, lockdep_is_held(&disk->io_filter_lock)) + +static const struct bpf_func_proto * +io_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + switch (func_id) { + case BPF_FUNC_map_lookup_elem: + return &bpf_map_lookup_elem_proto; + case BPF_FUNC_map_update_elem: + return &bpf_map_update_elem_proto; + case BPF_FUNC_map_delete_elem: + return &bpf_map_delete_elem_proto; + case BPF_FUNC_map_push_elem: + return &bpf_map_push_elem_proto; + case BPF_FUNC_map_pop_elem: + return &bpf_map_pop_elem_proto; + case BPF_FUNC_map_peek_elem: + return &bpf_map_peek_elem_proto; + case BPF_FUNC_trace_printk: + if (capable(CAP_SYS_ADMIN)) + return bpf_get_trace_printk_proto(); + fallthrough; + default: + return NULL; + } +} + +const struct bpf_prog_ops io_filter_prog_ops = { +}; + +static bool io_filter_is_valid_access(int off, int size, + enum bpf_access_type type, + const struct bpf_prog *prog, + struct bpf_insn_access_aux *info) +{ + const __u32 size_default = sizeof(__u32); + + if (type != BPF_READ) + return false; + + if (off < 0 || off >= offsetofend(struct bpf_io_request, opf)) + return false; + + if (off % size != 0) + return false; + + switch (off) { + case offsetof(struct bpf_io_request, sector_start): + return size == sizeof(__u64); + case offsetof(struct bpf_io_request, sector_cnt): + return size == sizeof(__u32); + case bpf_ctx_range(struct bpf_io_request, opf): + bpf_ctx_record_field_size(info, size_default); + return bpf_ctx_narrow_access_ok(off, size, size_default); + default: + return false; + } +} + +const struct bpf_verifier_ops io_filter_verifier_ops = { + .get_func_proto = io_filter_func_proto, + .is_valid_access = io_filter_is_valid_access, +}; + +#define BPF_MAX_PROGS 64 + +int io_filter_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct gendisk *disk; + struct fd f; + struct bpf_prog_array *old_array; + struct bpf_prog_array *new_array; + int ret; + + if (attr->attach_flags) + return -EINVAL; + + f = fdget(attr->target_fd); + if (!f.file) + return -EBADF; + + disk = I_BDEV(f.file->f_mapping->host)->bd_disk; + if (disk == NULL) + return -ENXIO; + + ret = mutex_lock_interruptible(&disk->io_filter_lock); + if (ret) + return ret; + + old_array = io_filter_rcu_dereference_progs(disk); + if (old_array && bpf_prog_array_length(old_array) >= BPF_MAX_PROGS) { + ret = -E2BIG; + goto unlock; + } + + ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array); + if (ret < 0) + goto unlock; + + rcu_assign_pointer(disk->progs, new_array); + bpf_prog_array_free(old_array); + +unlock: + mutex_unlock(&disk->io_filter_lock); + return ret; +} + +int io_filter_prog_detach(const union bpf_attr *attr) +{ + struct bpf_prog *prog; + struct gendisk *disk; + struct fd f; + struct bpf_prog_array *old_array; + struct bpf_prog_array *new_array; + int ret; + + if (attr->attach_flags) + return -EINVAL; + + /* increments prog refcnt */ + prog = bpf_prog_get_type(attr->attach_bpf_fd, + BPF_PROG_TYPE_IO_FILTER); + + if (IS_ERR(prog)) + return PTR_ERR(prog); + + f = fdget(attr->target_fd); + if (!f.file) { + ret = -EBADF; + goto put; + } + + disk = I_BDEV(f.file->f_mapping->host)->bd_disk; + if (disk == NULL) { + ret = -ENXIO; + goto put; + } + + ret = mutex_lock_interruptible(&disk->io_filter_lock); + if (ret) + goto put; + + old_array = io_filter_rcu_dereference_progs(disk); + ret = bpf_prog_array_copy(old_array, prog, NULL, &new_array); + if (ret) + goto unlock; + + rcu_assign_pointer(disk->progs, new_array); + bpf_prog_array_free(old_array); + bpf_prog_put(prog); /* put for detaching of program from dev */ + +unlock: + mutex_unlock(&disk->io_filter_lock); +put: + bpf_prog_put(prog); /* put for bpf_prog_get_type */ + return ret; +} + +/* allows IO by default if no programs attached */ +int io_filter_bpf_run(struct bio *bio) +{ + struct bpf_io_request io_req = { + .sector_start = bio->bi_iter.bi_sector, + .sector_cnt = bio_sectors(bio), + .opf = bio->bi_opf, + }; + + return BPF_PROG_RUN_ARRAY_CHECK(bio->bi_disk->progs, &io_req, BPF_PROG_RUN); +} + +void io_filter_bpf_init(struct gendisk *disk) +{ + mutex_init(&disk->io_filter_lock); +} + +void io_filter_bpf_free(struct gendisk *disk) +{ + struct bpf_prog_array_item *item; + struct bpf_prog_array *array; + + mutex_destroy(&disk->io_filter_lock); + + array = io_filter_rcu_dereference_progs(disk); + if (!array) + return; + + for (item = array->items; item->prog; item++) + bpf_prog_put(item->prog); + + bpf_prog_array_free(array); +} diff --git a/block/blk-bpf-io-filter.h b/block/blk-bpf-io-filter.h new file mode 100644 index 000000000000..cca705c4659e --- /dev/null +++ b/block/blk-bpf-io-filter.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _BLK_BPF_IO_FILTER +#define _BLK_BPF_IO_FILTER + +#ifdef CONFIG_BPF_IO_FILTER +void io_filter_bpf_init(struct gendisk *disk); +void io_filter_bpf_free(struct gendisk *disk); +int io_filter_bpf_run(struct bio *bio); +#else +static inline void io_filter_bpf_init(struct gendisk *disk) { } +static inline void io_filter_bpf_free(struct gendisk *disk) { } +static inline int io_filter_bpf_run(struct bio *bio) { return IO_ALLOW; } +#endif + +#endif /* _BLK_BPF_IO_FILTER */ diff --git a/block/blk-core.c b/block/blk-core.c index 03252af8c82c..740ac4807f41 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -50,6 +50,7 @@ #include "blk-mq-sched.h" #include "blk-pm.h" #include "blk-rq-qos.h" +#include "blk-bpf-io-filter.h" #ifdef CONFIG_DEBUG_FS struct dentry *blk_debugfs_root; @@ -1005,6 +1006,11 @@ generic_make_request_checks(struct bio *bio) } } + if (!io_filter_bpf_run(bio)) { + status = BLK_STS_PROTECTION; + goto end_io; + } + if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) bio->bi_opf &= ~REQ_HIPRI; diff --git a/block/genhd.c b/block/genhd.c index 1a7659327664..cff346c78ec6 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -25,6 +25,7 @@ #include #include "blk.h" +#include "blk-bpf-io-filter.h" static DEFINE_MUTEX(block_class_lock); static struct kobject *block_depr; @@ -935,6 +936,7 @@ void del_gendisk(struct gendisk *disk) if (!sysfs_deprecated) sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); pm_runtime_set_memalloc_noio(disk_to_dev(disk), false); + io_filter_bpf_free(disk); device_del(disk_to_dev(disk)); } EXPORT_SYMBOL(del_gendisk); @@ -1719,6 +1721,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) disk->minors = minors; rand_initialize_disk(disk); + io_filter_bpf_init(disk); disk_to_dev(disk)->class = &block_class; disk_to_dev(disk)->type = &disk_type; device_initialize(disk_to_dev(disk)); diff --git a/include/linux/bpf_io_filter.h b/include/linux/bpf_io_filter.h new file mode 100644 index 000000000000..6f8a3da963ed --- /dev/null +++ b/include/linux/bpf_io_filter.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _BPF_IO_FILTER_H +#define _BPF_IO_FILTER_H + +#include +struct bpf_prog; + +#ifdef CONFIG_BPF_IO_FILTER +int io_filter_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog); +int io_filter_prog_detach(const union bpf_attr *attr); +#else +static inline int io_filter_prog_attach(const union bpf_attr *attr, + struct bpf_prog *prog) +{ + return -EINVAL; +} +static inline int io_filter_prog_detach(const union bpf_attr *attr) +{ + return -EINVAL; +} +#endif +#endif /* _BPF_IO_FILTER_H */ diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index a18ae82a298a..f05193a2756e 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -49,6 +49,10 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, raw_tracepoint_writable, BPF_PROG_TYPE(BPF_PROG_TYPE_TRACING, tracing, void *, void *) #endif +#ifdef CONFIG_BPF_IO_FILTER +BPF_PROG_TYPE(BPF_PROG_TYPE_IO_FILTER, io_filter, + struct bpf_io_request, struct bpf_io_request) +#endif #ifdef CONFIG_CGROUP_BPF BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev, struct bpf_cgroup_dev_ctx, struct bpf_cgroup_dev_ctx) diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 392aad5e29a2..2da2cb1d0c46 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -209,6 +209,10 @@ struct gendisk { int node_id; struct badblocks *bb; struct lockdep_map lockdep_map; +#ifdef CONFIG_BPF_IO_FILTER + struct bpf_prog_array __rcu *progs; + struct mutex io_filter_lock; +#endif }; #if IS_REACHABLE(CONFIG_CDROM) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 8bd33050b7bb..4f84ab93d82c 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -189,6 +189,7 @@ enum bpf_prog_type { BPF_PROG_TYPE_STRUCT_OPS, BPF_PROG_TYPE_EXT, BPF_PROG_TYPE_LSM, + BPF_PROG_TYPE_IO_FILTER, }; enum bpf_attach_type { @@ -226,6 +227,7 @@ enum bpf_attach_type { BPF_CGROUP_INET4_GETSOCKNAME, BPF_CGROUP_INET6_GETSOCKNAME, BPF_XDP_DEVMAP, + BPF_BIO_SUBMIT, __MAX_BPF_ATTACH_TYPE }; @@ -4261,4 +4263,13 @@ struct bpf_pidns_info { __u32 pid; __u32 tgid; }; + +#define IO_ALLOW 1 +#define IO_BLOCK 0 + +struct bpf_io_request { + __u64 sector_start; /* first sector */ + __u32 sector_cnt; /* number of sectors */ + __u32 opf; /* bio->bi_opf */ +}; #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/init/Kconfig b/init/Kconfig index 0498af567f70..f44de091757e 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1647,6 +1647,14 @@ config KALLSYMS_BASE_RELATIVE # syscall, maps, verifier +config BPF_IO_FILTER + bool "Instrumentation of block io filtering subsystem with BPF" + depends on BPF_EVENTS + depends on BPF_SYSCALL + help + Enables instrumentation of the hooks in block subsystem with eBPF + programs for observing and filtering io. + config BPF_LSM bool "LSM Instrumentation with BPF" depends on BPF_EVENTS diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 0fd80ac81f70..179c37efe8e2 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -29,6 +29,7 @@ #include #include #include +#include #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ @@ -1964,6 +1965,7 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type, switch (prog_type) { case BPF_PROG_TYPE_TRACING: + case BPF_PROG_TYPE_IO_FILTER: case BPF_PROG_TYPE_LSM: case BPF_PROG_TYPE_STRUCT_OPS: case BPF_PROG_TYPE_EXT: @@ -2815,6 +2817,8 @@ attach_type_to_prog_type(enum bpf_attach_type attach_type) return BPF_PROG_TYPE_CGROUP_SOCKOPT; case BPF_TRACE_ITER: return BPF_PROG_TYPE_TRACING; + case BPF_BIO_SUBMIT: + return BPF_PROG_TYPE_IO_FILTER; default: return BPF_PROG_TYPE_UNSPEC; } @@ -2858,6 +2862,9 @@ static int bpf_prog_attach(const union bpf_attr *attr) case BPF_PROG_TYPE_LIRC_MODE2: ret = lirc_prog_attach(attr, prog); break; + case BPF_PROG_TYPE_IO_FILTER: + ret = io_filter_prog_attach(attr, prog); + break; case BPF_PROG_TYPE_FLOW_DISSECTOR: ret = netns_bpf_prog_attach(attr, prog); break; @@ -2906,6 +2913,8 @@ static int bpf_prog_detach(const union bpf_attr *attr) case BPF_PROG_TYPE_CGROUP_SYSCTL: case BPF_PROG_TYPE_SOCK_OPS: return cgroup_bpf_prog_detach(attr, ptype); + case BPF_PROG_TYPE_IO_FILTER: + return io_filter_prog_detach(attr); default: return -EINVAL; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 94cead5a43e5..71372e99a722 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2613,6 +2613,7 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env, case BPF_PROG_TYPE_LWT_SEG6LOCAL: case BPF_PROG_TYPE_SK_REUSEPORT: case BPF_PROG_TYPE_FLOW_DISSECTOR: + case BPF_PROG_TYPE_IO_FILTER: case BPF_PROG_TYPE_CGROUP_SKB: if (t == BPF_WRITE) return false; diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c index 768bf77df886..765702ae0189 100644 --- a/tools/bpf/bpftool/feature.c +++ b/tools/bpf/bpftool/feature.c @@ -383,6 +383,8 @@ static void probe_kernel_image_config(const char *define_prefix) { "CONFIG_IPV6_SEG6_BPF", }, /* BPF_PROG_TYPE_LIRC_MODE2 and related helpers */ { "CONFIG_BPF_LIRC_MODE2", }, + /* BPF_PROG_TYPE_IO_FILTER */ + { "CONFIG_BPF_IO_FILTER", }, /* BPF stream parser and BPF socket maps */ { "CONFIG_BPF_STREAM_PARSER", }, /* xt_bpf module for passing BPF programs to netfilter */ diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 5cdf0bc049bd..0607ae6f6d90 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -86,6 +86,7 @@ static const char * const prog_type_name[] = { [BPF_PROG_TYPE_TRACING] = "tracing", [BPF_PROG_TYPE_STRUCT_OPS] = "struct_ops", [BPF_PROG_TYPE_EXT] = "ext", + [BPF_PROG_TYPE_IO_FILTER] = "io_filter", }; static const char * const attach_type_name[__MAX_BPF_ATTACH_TYPE] = { @@ -122,6 +123,7 @@ static const char * const attach_type_name[__MAX_BPF_ATTACH_TYPE] = { [BPF_TRACE_FEXIT] = "fexit", [BPF_MODIFY_RETURN] = "mod_ret", [BPF_LSM_MAC] = "lsm_mac", + [BPF_BIO_SUBMIT] = "bio_submit", }; extern const char * const map_type_name[]; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 8bd33050b7bb..f665e37b7277 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -189,6 +189,7 @@ enum bpf_prog_type { BPF_PROG_TYPE_STRUCT_OPS, BPF_PROG_TYPE_EXT, BPF_PROG_TYPE_LSM, + BPF_PROG_TYPE_IO_FILTER, }; enum bpf_attach_type { @@ -226,6 +227,7 @@ enum bpf_attach_type { BPF_CGROUP_INET4_GETSOCKNAME, BPF_CGROUP_INET6_GETSOCKNAME, BPF_XDP_DEVMAP, + BPF_BIO_SUBMIT, __MAX_BPF_ATTACH_TYPE }; @@ -4261,4 +4263,13 @@ struct bpf_pidns_info { __u32 pid; __u32 tgid; }; + +#define IO_ALLOW 1 +#define IO_BLOCK 0 + +struct bpf_io_request { + __u64 sector_start; /* first sector */ + __u32 sector_cnt; /* number of sectors */ + __u32 opf; /* bio->bi_opf */ +}; #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 11e4725b8b1c..609b16007891 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -6724,6 +6724,8 @@ static const struct bpf_sec_def section_defs[] = { BPF_EAPROG_SEC("cgroup/setsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT), BPF_PROG_SEC("struct_ops", BPF_PROG_TYPE_STRUCT_OPS), + BPF_APROG_SEC("io_filter", BPF_PROG_TYPE_IO_FILTER, + BPF_BIO_SUBMIT), }; #undef BPF_PROG_SEC_IMPL diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index 10cd8d1891f5..b882b200a402 100644 --- a/tools/lib/bpf/libbpf_probes.c +++ b/tools/lib/bpf/libbpf_probes.c @@ -109,6 +109,7 @@ probe_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, case BPF_PROG_TYPE_STRUCT_OPS: case BPF_PROG_TYPE_EXT: case BPF_PROG_TYPE_LSM: + case BPF_PROG_TYPE_IO_FILTER: default: break; } diff --git a/tools/testing/selftests/bpf/prog_tests/section_names.c b/tools/testing/selftests/bpf/prog_tests/section_names.c index 713167449c98..ef6658a776b1 100644 --- a/tools/testing/selftests/bpf/prog_tests/section_names.c +++ b/tools/testing/selftests/bpf/prog_tests/section_names.c @@ -158,6 +158,11 @@ static struct sec_name_test tests[] = { {0, BPF_PROG_TYPE_CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT}, {0, BPF_CGROUP_SETSOCKOPT}, }, + { + "io_filter", + {0, BPF_PROG_TYPE_IO_FILTER, BPF_BIO_SUBMIT}, + {0, BPF_BIO_SUBMIT}, + }, }; static void test_prog_type_by_name(const struct sec_name_test *test) From patchwork Wed Aug 12 16:33:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Leah Rumancik X-Patchwork-Id: 1343784 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=hv+/j9Md; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BRZy95SWGz9sTQ for ; Thu, 13 Aug 2020 02:33:21 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726642AbgHLQdT (ORCPT ); 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[34.74.119.39]) by smtp.googlemail.com with ESMTPSA id e8sm245374uar.11.2020.08.12.09.33.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Aug 2020 09:33:15 -0700 (PDT) From: Leah Rumancik To: bpf@vger.kernel.org, linux-block@vger.kernel.org Cc: leah.rumancik@gmail.com, orbekk@google.com, harshads@google.com, jasiu@google.com, saranyamohan@google.com, tytso@google.com, bvanassche@google.com Subject: [RFC PATCH 2/4] bpf: add protect_gpt sample program Date: Wed, 12 Aug 2020 16:33:03 +0000 Message-Id: <20200812163305.545447-3-leah.rumancik@gmail.com> X-Mailer: git-send-email 2.28.0.236.gb10cc79966-goog In-Reply-To: <20200812163305.545447-1-leah.rumancik@gmail.com> References: <20200812163305.545447-1-leah.rumancik@gmail.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Sample program to protect GUID partition table. Uses IO filter bpf program type. Signed-off-by: Kjetil Ørbekk Signed-off-by: Harshad Shirwadkar Signed-off-by: Leah Rumancik --- samples/bpf/Makefile | 3 + samples/bpf/protect_gpt_kern.c | 21 ++++++ samples/bpf/protect_gpt_user.c | 133 +++++++++++++++++++++++++++++++++ 3 files changed, 157 insertions(+) create mode 100644 samples/bpf/protect_gpt_kern.c create mode 100644 samples/bpf/protect_gpt_user.c diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 8403e4762306..f02ae9b2a283 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -53,6 +53,7 @@ tprogs-y += task_fd_query tprogs-y += xdp_sample_pkts tprogs-y += ibumad tprogs-y += hbm +tprogs-y += protect_gpt # Libbpf dependencies LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a @@ -109,6 +110,7 @@ task_fd_query-objs := bpf_load.o task_fd_query_user.o $(TRACE_HELPERS) xdp_sample_pkts-objs := xdp_sample_pkts_user.o $(TRACE_HELPERS) ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS) hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS) +protect_gpt-objs := bpf_load.o protect_gpt_user.o $(TRACE_HELPERS) # Tell kbuild to always build the programs always-y := $(tprogs-y) @@ -170,6 +172,7 @@ always-y += ibumad_kern.o always-y += hbm_out_kern.o always-y += hbm_edt_kern.o always-y += xdpsock_kern.o +always-y += protect_gpt_kern.o ifeq ($(ARCH), arm) # Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux diff --git a/samples/bpf/protect_gpt_kern.c b/samples/bpf/protect_gpt_kern.c new file mode 100644 index 000000000000..cc49d66c120a --- /dev/null +++ b/samples/bpf/protect_gpt_kern.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include "bpf/bpf_helpers.h" + +char _license[] SEC("license") = "GPL"; + +#define GPT_SECTORS 34 + +SEC("gpt_io_filter") +int protect_gpt(struct bpf_io_request *io_req) +{ + /* within GPT and not a read operation */ + if (io_req->sector_start < GPT_SECTORS && (io_req->opf & REQ_OP_MASK) != REQ_OP_READ) + return IO_BLOCK; + + return IO_ALLOW; +} + + diff --git a/samples/bpf/protect_gpt_user.c b/samples/bpf/protect_gpt_user.c new file mode 100644 index 000000000000..21ca25bc78af --- /dev/null +++ b/samples/bpf/protect_gpt_user.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include "trace_helpers.h" +#include "bpf_load.h" + +/* + * user program to load bpf program (protect_gpt_kern) to prevent + * writing to GUID parititon table + * + * argument 1: device where program will be attached (ie. /dev/sda) + * argument 2: name for pinned program + * argument 3: --attach or --detach to attach/detach program + */ + +static int attach(char *dev, char *path) +{ + struct bpf_object *obj; + int ret, devfd, progfd; + + progfd = bpf_obj_get(path); + if (progfd >= 0) { + fprintf(stderr, "Error: object already pinned at given location (%s)\n", path); + return 1; + } + + ret = bpf_prog_load("protect_gpt_kern.o", + BPF_PROG_TYPE_IO_FILTER, &obj, &progfd); + if (ret) { + fprintf(stderr, "Error: failed to load program\n"); + return 1; + } + + devfd = open(dev, O_RDONLY); + if (devfd == -1) { + fprintf(stderr, "Error: failed to open block device %s\n", dev); + return 1; + } + + ret = bpf_prog_attach(progfd, devfd, BPF_BIO_SUBMIT, 0); + if (ret) { + fprintf(stderr, "Error: failed to attach program to device\n"); + close(devfd); + return 1; + } + + ret = bpf_obj_pin(progfd, path); + if (ret != 0) { + fprintf(stderr, "Error pinning program: %s\n", strerror(errno)); + fprintf(stderr, "Detaching program from device\n"); + + if (bpf_prog_detach2(progfd, devfd, BPF_BIO_SUBMIT)) + fprintf(stderr, "Error: failed to detach program\n"); + + close(devfd); + return 1; + } + + close(devfd); + printf("Attached protect_gpt program to device %s.\n", dev); + printf("Program pinned to %s.\n", path); + return 0; +} + +static int detach(char *dev, char *path) +{ + int ret, devfd, progfd; + + progfd = bpf_obj_get(path); + if (progfd < 0) { + fprintf(stderr, "Error: failed to get pinned program from path %s\n", path); + return 1; + } + + devfd = open(dev, O_RDONLY); + if (devfd == -1) { + fprintf(stderr, "Error: failed to open block device %s\n", dev); + return 1; + } + + ret = bpf_prog_detach2(progfd, devfd, BPF_BIO_SUBMIT); + if (ret) { + fprintf(stderr, "Error: failed to detach program\n"); + close(devfd); + return 1; + } + + close(devfd); + + ret = unlink(path); + if (ret < 0) { + fprintf(stderr, "Error unpinning map at %s: %s\n", path, strerror(errno)); + return 1; + } + + printf("Detached and unpinned program.\n"); + return 0; +} + +static void usage(char *exec) +{ + printf("Usage:\n"); + printf("\t %s --attach\n", exec); + printf("\t %s --detach\n", exec); +} + +int main(int argc, char **argv) +{ + char path[256]; + + if (argc != 4) { + usage(argv[0]); + return 1; + } + + strcpy(path, "/sys/fs/bpf/"); + strcat(path, argv[2]); + + if (strcmp(argv[3], "--attach") == 0) + return attach(argv[1], path); + else if (strcmp(argv[3], "--detach") == 0) + return detach(argv[1], path); + + fprintf(stderr, "Error: invalid flag, please specify --attach or --detach"); + return 1; +} + From patchwork Wed Aug 12 16:33:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Leah Rumancik X-Patchwork-Id: 1343782 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; 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[34.74.119.39]) by smtp.googlemail.com with ESMTPSA id e8sm245374uar.11.2020.08.12.09.33.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Aug 2020 09:33:16 -0700 (PDT) From: Leah Rumancik To: bpf@vger.kernel.org, linux-block@vger.kernel.org Cc: leah.rumancik@gmail.com, orbekk@google.com, harshads@google.com, jasiu@google.com, saranyamohan@google.com, tytso@google.com, bvanassche@google.com Subject: [RFC PATCH 3/4] bpf: add eBPF IO filter documentation Date: Wed, 12 Aug 2020 16:33:04 +0000 Message-Id: <20200812163305.545447-4-leah.rumancik@gmail.com> X-Mailer: git-send-email 2.28.0.236.gb10cc79966-goog In-Reply-To: <20200812163305.545447-1-leah.rumancik@gmail.com> References: <20200812163305.545447-1-leah.rumancik@gmail.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add page in Documentation/block describing overview of IO filter Signed-off-by: Kjetil Ørbekk Signed-off-by: Harshad Shirwadkar Signed-off-by: Leah Rumancik --- Documentation/block/bpf_io_filter.rst | 28 +++++++++++++++++++++++++++ Documentation/block/index.rst | 1 + 2 files changed, 29 insertions(+) create mode 100644 Documentation/block/bpf_io_filter.rst diff --git a/Documentation/block/bpf_io_filter.rst b/Documentation/block/bpf_io_filter.rst new file mode 100644 index 000000000000..956997576ae5 --- /dev/null +++ b/Documentation/block/bpf_io_filter.rst @@ -0,0 +1,28 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================== +IO Filtering with eBPF +====================== + +Bio requests can be filtered with the eBPF IO filter program type (BPF_PROG_TYPE_IO_FILTER). To use this program type, the kernel must be compiled with CONFIG_BPF_IO_FILTER. + +Attachment +========== + +IO filter programs can be attached to disks using the BPF_BIO_SUBMIT attach type. Up to 64 filter programs can be attached to a single disk. References to the attached programs are stored in the gendisk struct as a bpf_prog_array. + +API +=== + +Data is passed between the userspace and kernel eBPF code via a new struct bpf_io_request. This struct contains three fields: sector_start (starting sector of the bio request), sector_cnt (size of the request in sectors), and opf (operation information, opf field from the bio). + +Hook +==== + +The eBPF programs for a given disk are run whenever a bio request is submitted to that disk. The eBPF programs return IO_BLOCK or IO_ALLOW. If any of the programs return IO_BLOCK, the bio request is blocked. Because of the placement of the hook in submit_bio, as of this version, mechanisms which bypass submit_bio, such as SG_IO and NVMe passthrough, are not able to be filtered. + +Example +======= + +An example, protect_gpt, is provided in the /samples/bpf/ folder. This sample uses an IO filter program to protect the GUID partition table by preventing writes to the first 34 sectors. + diff --git a/Documentation/block/index.rst b/Documentation/block/index.rst index 026addfc69bc..145930622a92 100644 --- a/Documentation/block/index.rst +++ b/Documentation/block/index.rst @@ -24,3 +24,4 @@ Block stat switching-sched writeback_cache_control + bpf-io-filter From patchwork Wed Aug 12 16:33:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Leah Rumancik X-Patchwork-Id: 1343783 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=qxNmTwZs; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BRZy91vcJz9sTN for ; Thu, 13 Aug 2020 02:33:21 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726567AbgHLQdT (ORCPT ); Wed, 12 Aug 2020 12:33:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726510AbgHLQdT (ORCPT ); Wed, 12 Aug 2020 12:33:19 -0400 Received: from mail-vk1-xa42.google.com (mail-vk1-xa42.google.com [IPv6:2607:f8b0:4864:20::a42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BEC9C061383; Wed, 12 Aug 2020 09:33:18 -0700 (PDT) Received: by mail-vk1-xa42.google.com with SMTP id j7so631999vkk.12; Wed, 12 Aug 2020 09:33:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=yVWs6zbYAWogM7xh2rvQBTsIFOdnoXyUVimbGjZjhcc=; b=qxNmTwZs+xBcyZACYZc/yYvgSFNZdLmDOA/fEh3uH5bfUt8LTmIVy7krF9JDa8zlGK fyceeq3upQeAXsd2MZi1sQIT8YHhT49+4mfmYIAh0+u9wvsX/02vDzAVvxov51741Apd UOj+15g3DwULmI9Rq1247/Zk60NW448209ijDhej2lElfU7FMBBJ39QIV0oGY6j6Sn8r U5iwX05R4laFjVr2rS7WpzOO2Mv5R4MFwZCHh8xWqspZoeX2emAWm62aeKsZqsWR/Xhc XoXDRj19rmLYPtkC3W+3sfDKlInDo8tJLF0HD6Fd+mOe1qTOlhIJLQtF7sxdYihYUW1z QN8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=yVWs6zbYAWogM7xh2rvQBTsIFOdnoXyUVimbGjZjhcc=; b=BGsrwKaa1yh9XQ7nw4fLSLzfnvZUM6NVuLNnOQT0mgSsCShkRN88tXIjVYNuypQPnc gvTEVAwKlV1dGj/cl2b9bkeTRu9dJ03nwBqQhEph0sRBwd7b1xtPthZd4Q4xw+HO/KUM K20EdeeT9Qce8px3Xl3ByOtA5Bec0u2ijFg34w3k/RIDW1iSGUChF7LHfxk+tX1TuwHd 6VuEcFchTOTRxkb6asXyAtcWAtchKPQy92ZRQwH10MPwmyYGllQn/D/LG66IJDb8urYi lUFNvJV89LI5gDZnbi/NIGGiz4wXI9Sge158vGLPgZDnrYY+NsGiaUuUxdmJH0UlLa+M t6eQ== X-Gm-Message-State: AOAM533nPLbHVPTqj6iGrdgnPNLrSoqrOGMNIWoHk+u6ne3tCdzmboBR GEApsO01uuyKCNBa6DElDYmGtKn39eI= X-Google-Smtp-Source: ABdhPJwdAcFz2xvNbU1VKmOz/HNyXm7InfYeTXgJI5oFXAC4cFVRsjvdql/P1DsR+IZQgtrzoQkgaw== X-Received: by 2002:a1f:230f:: with SMTP id j15mr180827vkj.83.1597249996956; Wed, 12 Aug 2020 09:33:16 -0700 (PDT) Received: from ebpf-cloudtop.c.googlers.com.com (39.119.74.34.bc.googleusercontent.com. [34.74.119.39]) by smtp.googlemail.com with ESMTPSA id e8sm245374uar.11.2020.08.12.09.33.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Aug 2020 09:33:16 -0700 (PDT) From: Leah Rumancik To: bpf@vger.kernel.org, linux-block@vger.kernel.org Cc: leah.rumancik@gmail.com, orbekk@google.com, harshads@google.com, jasiu@google.com, saranyamohan@google.com, tytso@google.com, bvanassche@google.com Subject: [RFC PATCH 4/4] bpf: add BPF_PROG_TYPE_LSM to bpftool name array Date: Wed, 12 Aug 2020 16:33:05 +0000 Message-Id: <20200812163305.545447-5-leah.rumancik@gmail.com> X-Mailer: git-send-email 2.28.0.236.gb10cc79966-goog In-Reply-To: <20200812163305.545447-1-leah.rumancik@gmail.com> References: <20200812163305.545447-1-leah.rumancik@gmail.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Update prog_type_name[] to include missing entry for BPF_PROG_TYPE_LSM Signed-off-by: Kjetil Ørbekk Signed-off-by: Harshad Shirwadkar Signed-off-by: Leah Rumancik --- tools/bpf/bpftool/main.h | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 0607ae6f6d90..ccc6ac9f82c2 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -86,6 +86,7 @@ static const char * const prog_type_name[] = { [BPF_PROG_TYPE_TRACING] = "tracing", [BPF_PROG_TYPE_STRUCT_OPS] = "struct_ops", [BPF_PROG_TYPE_EXT] = "ext", + [BPF_PROG_TYPE_LSM] = "lsm", [BPF_PROG_TYPE_IO_FILTER] = "io_filter", };