From patchwork Tue Jul 12 14:58:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 589913 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00081C43334 for ; Tue, 12 Jul 2022 15:07:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234045AbiGLPHu (ORCPT ); Tue, 12 Jul 2022 11:07:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233848AbiGLPGi (ORCPT ); Tue, 12 Jul 2022 11:06:38 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 56B5EC4479 for ; Tue, 12 Jul 2022 08:01:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1657638040; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=64L9JkrS+sJc/j6tZXOh2W08Ae45YedsxQt/Ab9no0k=; b=RuQJY6/3Y2KH9z3GTvk+dLd6Uw1+7AYhij09Za5fYn3jqZctDJoBBSz3bP1ApriK/+GrgW XRaa2We8lp+VA5jL8ZsJtm8a7RIyfr+w3W4C0NTl5zyWXfXI3jJWAA+bM1FRCvkhoG67gN Cos0eVNfgEE24RSSwLPCnCkqjv424G4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-306-kDtHo_m2MuytmVpTdBsuRg-1; Tue, 12 Jul 2022 11:00:31 -0400 X-MC-Unique: kDtHo_m2MuytmVpTdBsuRg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 79FFF803520; Tue, 12 Jul 2022 15:00:30 +0000 (UTC) Received: from plouf.redhat.com (unknown [10.39.195.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 842C22166B26; Tue, 12 Jul 2022 15:00:26 +0000 (UTC) From: Benjamin Tissoires To: Greg KH , Jiri Kosina , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Shuah Khan , Dave Marchevsky , Joe Stringer , Jonathan Corbet Cc: Tero Kristo , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, Benjamin Tissoires Subject: [PATCH bpf-next v6 21/23] samples/bpf: add new hid_mouse example Date: Tue, 12 Jul 2022 16:58:48 +0200 Message-Id: <20220712145850.599666-22-benjamin.tissoires@redhat.com> In-Reply-To: <20220712145850.599666-1-benjamin.tissoires@redhat.com> References: <20220712145850.599666-1-benjamin.tissoires@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Everything should be available in the selftest part of the tree, but providing an example without uhid and hidraw will be more easy to follow for users. Signed-off-by: Benjamin Tissoires --- changes in v6: - clean up code by removing old comments changes in v5: - bring back same features than v3, with the new API changes in v4: - dropped the not-yet-implemented rdesc_fixup - use the new API changes in v3: - use the new hid_get_data API - add a comment for the report descriptor fixup to explain what is done changes in v2: - split the series by bpf/libbpf/hid/selftests and samples --- samples/bpf/.gitignore | 1 + samples/bpf/Makefile | 23 ++++++ samples/bpf/hid_mouse.bpf.c | 134 ++++++++++++++++++++++++++++++++ samples/bpf/hid_mouse.c | 150 ++++++++++++++++++++++++++++++++++++ 4 files changed, 308 insertions(+) create mode 100644 samples/bpf/hid_mouse.bpf.c create mode 100644 samples/bpf/hid_mouse.c diff --git a/samples/bpf/.gitignore b/samples/bpf/.gitignore index 0e7bfdbff80a..65440bd618b2 100644 --- a/samples/bpf/.gitignore +++ b/samples/bpf/.gitignore @@ -2,6 +2,7 @@ cpustat fds_example hbm +hid_mouse ibumad lathist lwt_len_hist diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 5002a5b9a7da..e67c1a0fed1c 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -57,6 +57,8 @@ tprogs-y += xdp_redirect_map tprogs-y += xdp_redirect tprogs-y += xdp_monitor +tprogs-y += hid_mouse + # Libbpf dependencies LIBBPF_SRC = $(TOOLS_PATH)/lib/bpf LIBBPF_OUTPUT = $(abspath $(BPF_SAMPLES_PATH))/libbpf @@ -119,6 +121,8 @@ xdp_redirect-objs := xdp_redirect_user.o $(XDP_SAMPLE) xdp_monitor-objs := xdp_monitor_user.o $(XDP_SAMPLE) xdp_router_ipv4-objs := xdp_router_ipv4_user.o $(XDP_SAMPLE) +hid_mouse-objs := hid_mouse.o + # Tell kbuild to always build the programs always-y := $(tprogs-y) always-y += sockex1_kern.o @@ -340,6 +344,8 @@ $(obj)/hbm_out_kern.o: $(src)/hbm.h $(src)/hbm_kern.h $(obj)/hbm.o: $(src)/hbm.h $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h +$(obj)/hid_mouse.o: $(obj)/hid_mouse.skel.h + # Override includes for xdp_sample_user.o because $(srctree)/usr/include in # TPROGS_CFLAGS causes conflicts XDP_SAMPLE_CFLAGS += -Wall -O2 \ @@ -424,6 +430,23 @@ $(BPF_SKELS_LINKED): $(BPF_OBJS_LINKED) $(BPFTOOL) @echo " BPF GEN-SKEL" $(@:.skel.h=) $(Q)$(BPFTOOL) gen skeleton $(@:.skel.h=.lbpf.o) name $(notdir $(@:.skel.h=)) > $@ +# Generate BPF skeletons for non XDP progs +OTHER_BPF_SKELS := hid_mouse.skel.h + +hid_mouse.skel.h-deps := hid_mouse.bpf.o + +OTHER_BPF_SRCS_LINKED := $(patsubst %.skel.h,%.bpf.c, $(OTHER_BPF_SKELS)) +OTHER_BPF_OBJS_LINKED := $(patsubst %.bpf.c,$(obj)/%.bpf.o, $(OTHER_BPF_SRCS_LINKED)) +OTHER_BPF_SKELS_LINKED := $(addprefix $(obj)/,$(OTHER_BPF_SKELS)) + +$(OTHER_BPF_SKELS_LINKED): $(OTHER_BPF_OBJS_LINKED) $(BPFTOOL) + @echo " BPF GEN-OBJ " $(@:.skel.h=) + $(Q)$(BPFTOOL) gen object $(@:.skel.h=.lbpf.o) $(addprefix $(obj)/,$($(@F)-deps)) + @echo " BPF GEN-SKEL" $(@:.skel.h=) + $(Q)$(BPFTOOL) gen skeleton $(@:.skel.h=.lbpf.o) name $(notdir $(@:.skel.h=_lskel)) > $@ +# $(call msg,GEN-SKEL,$@) +# $(Q)$(BPFTOOL) gen skeleton $< > $@ + # asm/sysreg.h - inline assembly used by it is incompatible with llvm. # But, there is no easy way to fix it, so just exclude it since it is # useless for BPF samples. diff --git a/samples/bpf/hid_mouse.bpf.c b/samples/bpf/hid_mouse.bpf.c new file mode 100644 index 000000000000..0113e603f7a7 --- /dev/null +++ b/samples/bpf/hid_mouse.bpf.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include +#include + +/* following are kfuncs exported by HID for HID-BPF */ +extern int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, u32 flags) __ksym; +extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx, + unsigned int offset, + const size_t __sz) __ksym; +extern void hid_bpf_data_release(__u8 *data) __ksym; +extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx) __ksym; + +struct attach_prog_args { + int prog_fd; + unsigned int hid; + int retval; +}; + +SEC("syscall") +int attach_prog(struct attach_prog_args *ctx) +{ + ctx->retval = hid_bpf_attach_prog(ctx->hid, + ctx->prog_fd, + 0); + return 0; +} + +SEC("fmod_ret/hid_bpf_device_event") +int BPF_PROG(hid_y_event, struct hid_bpf_ctx *hctx) +{ + s16 y; + __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 9 /* size */); + + if (!data) + return 0; /* EPERM check */ + + bpf_printk("event: size: %d", hctx->size); + bpf_printk("incoming event: %02x %02x %02x", + data[0], + data[1], + data[2]); + bpf_printk(" %02x %02x %02x", + data[3], + data[4], + data[5]); + bpf_printk(" %02x %02x %02x", + data[6], + data[7], + data[8]); + + y = data[3] | (data[4] << 8); + + y = -y; + + data[3] = y & 0xFF; + data[4] = (y >> 8) & 0xFF; + + bpf_printk("modified event: %02x %02x %02x", + data[0], + data[1], + data[2]); + bpf_printk(" %02x %02x %02x", + data[3], + data[4], + data[5]); + bpf_printk(" %02x %02x %02x", + data[6], + data[7], + data[8]); + + return 0; +} + +SEC("fmod_ret/hid_bpf_device_event") +int BPF_PROG(hid_x_event, struct hid_bpf_ctx *hctx) +{ + s16 x; + __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 9 /* size */); + + if (!data) + return 0; /* EPERM check */ + + x = data[1] | (data[2] << 8); + + x = -x; + + data[1] = x & 0xFF; + data[2] = (x >> 8) & 0xFF; + return 0; +} + +SEC("fmod_ret/hid_bpf_rdesc_fixup") +int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hctx) +{ + __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 4096 /* size */); + + if (!data) + return 0; /* EPERM check */ + + bpf_printk("rdesc: %02x %02x %02x", + data[0], + data[1], + data[2]); + bpf_printk(" %02x %02x %02x", + data[3], + data[4], + data[5]); + bpf_printk(" %02x %02x %02x ...", + data[6], + data[7], + data[8]); + + /* + * The original report descriptor contains: + * + * 0x05, 0x01, // Usage Page (Generic Desktop) 30 + * 0x16, 0x01, 0x80, // Logical Minimum (-32767) 32 + * 0x26, 0xff, 0x7f, // Logical Maximum (32767) 35 + * 0x09, 0x30, // Usage (X) 38 + * 0x09, 0x31, // Usage (Y) 40 + * + * So byte 39 contains Usage X and byte 41 Usage Y. + * + * We simply swap the axes here. + */ + data[39] = 0x31; + data[41] = 0x30; + + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/samples/bpf/hid_mouse.c b/samples/bpf/hid_mouse.c new file mode 100644 index 000000000000..f6e5f09026eb --- /dev/null +++ b/samples/bpf/hid_mouse.c @@ -0,0 +1,150 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2022 Benjamin Tissoires + */ + +/* not sure why but this doesn't get preoperly imported */ +#define __must_check + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "bpf_util.h" +#include +#include + +#include "hid_mouse.skel.h" + +static bool running = true; + +struct attach_prog_args { + int prog_fd; + unsigned int hid; + int retval; +}; + +static void int_exit(int sig) +{ + running = false; + exit(0); +} + +static void usage(const char *prog) +{ + fprintf(stderr, + "%s: %s /sys/bus/hid/devices/0BUS:0VID:0PID:00ID\n\n", + __func__, prog); +} + +static int get_hid_id(const char *path) +{ + const char *str_id, *dir; + char uevent[1024]; + int fd; + + memset(uevent, 0, sizeof(uevent)); + snprintf(uevent, sizeof(uevent) - 1, "%s/uevent", path); + + fd = open(uevent, O_RDONLY | O_NONBLOCK); + if (fd < 0) + return -ENOENT; + + close(fd); + + dir = basename((char *)path); + + str_id = dir + sizeof("0003:0001:0A37."); + return (int)strtol(str_id, NULL, 16); +} + +int main(int argc, char **argv) +{ + struct hid_mouse_lskel *skel; + struct bpf_program *prog; + int err; + const char *optstr = ""; + const char *sysfs_path; + int opt, hid_id, attach_fd; + struct attach_prog_args args = { + .retval = -1, + }; + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr, + .ctx_in = &args, + .ctx_size_in = sizeof(args), + ); + + while ((opt = getopt(argc, argv, optstr)) != -1) { + switch (opt) { + default: + usage(basename(argv[0])); + return 1; + } + } + + if (optind == argc) { + usage(basename(argv[0])); + return 1; + } + + sysfs_path = argv[optind]; + if (!sysfs_path) { + perror("sysfs"); + return 1; + } + + skel = hid_mouse_lskel__open_and_load(); + if (!skel) { + fprintf(stderr, "%s %s:%d", __func__, __FILE__, __LINE__); + return -1; + } + + hid_id = get_hid_id(sysfs_path); + + if (hid_id < 0) { + fprintf(stderr, "can not open HID device: %m\n"); + return 1; + } + args.hid = hid_id; + + attach_fd = bpf_program__fd(skel->progs.attach_prog); + if (attach_fd < 0) { + fprintf(stderr, "can't locate attach prog: %m\n"); + return 1; + } + + bpf_object__for_each_program(prog, *skel->skeleton->obj) { + /* ignore syscalls */ + if (bpf_program__get_type(prog) != BPF_PROG_TYPE_TRACING) + continue; + + args.retval = -1; + args.prog_fd = bpf_program__fd(prog); + err = bpf_prog_test_run_opts(attach_fd, &tattr); + if (err) { + fprintf(stderr, "can't attach prog to hid device %d: %m (err: %d)\n", + hid_id, err); + return 1; + } + } + + signal(SIGINT, int_exit); + signal(SIGTERM, int_exit); + + while (running) + ; + + hid_mouse_lskel__destroy(skel); + + return 0; +}