From patchwork Mon Jun 4 16:33:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 925153 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=toke.dk Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; secure) header.d=toke.dk header.i=@toke.dk header.b="KS7cVOn+"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4100rF0lmQz9rvt for ; Tue, 5 Jun 2018 02:34:04 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751432AbeFDQeC (ORCPT ); Mon, 4 Jun 2018 12:34:02 -0400 Received: from mail.toke.dk ([52.28.52.200]:46861 "EHLO mail.toke.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750913AbeFDQeA (ORCPT ); Mon, 4 Jun 2018 12:34:00 -0400 Subject: [PATCH bpf-next v2 1/2] trace_helpers.c: Add helpers to poll multiple perf FDs for events DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1528130037; bh=m2y75027vl227l8cvhd/R07bvkqXIu6BpD4IzcaeZg8=; h=Subject:From:To:Date:From; b=KS7cVOn+SJvEb3dhxETYUTJJwf5CPYa/VoEh5rko+xp9WSfHM9BLuD5X3/GHuL5Hj A6UU97cFQa61aUqG9zReIFdRlDNZeZcIFEVhIhQpj12hSz71dNzx++Gt4FqRHckxCa 29gvNRqTX6iGbchHizJKiB/224eoqyQcxghAdK2POIoRJ1WADdnm+/xF4rkpcXlmi4 QKdxJXYw8FP4XO+NCgVyZeLM/qFNOBUMH6UGcXHjSv9MDlY4UUPOFV9cLLzLw7Fgxo euF9K59/yc2nl1L7B6dVoIUF4SL5r5/hPNx0Lq/NKf+OfMdN+6/rmTnCO3YpNG5of0 eRcJVjrw0jFVQ== From: Toke =?utf-8?q?H=C3=B8iland-J=C3=B8rgensen?= To: netdev@vger.kernel.org Date: Mon, 04 Jun 2018 18:33:56 +0200 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <152813003609.3465.618891361534945522.stgit@alrua-kau> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This adds two new helper functions to trace_helpers that supports polling multiple perf file descriptors for events. These are used to the XDP perf_event_output example, which needs to work with one perf fd per CPU. Signed-off-by: Toke Høiland-Jørgensen --- tools/testing/selftests/bpf/trace_helpers.c | 47 ++++++++++++++++++++++++++- tools/testing/selftests/bpf/trace_helpers.h | 4 ++ 2 files changed, 49 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 3868dcb63420..1e62d89f34cf 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -88,7 +88,7 @@ static int page_size; static int page_cnt = 8; static struct perf_event_mmap_page *header; -int perf_event_mmap(int fd) +int perf_event_mmap_header(int fd, struct perf_event_mmap_page **header) { void *base; int mmap_size; @@ -102,10 +102,15 @@ int perf_event_mmap(int fd) return -1; } - header = base; + *header = base; return 0; } +int perf_event_mmap(int fd) +{ + return perf_event_mmap_header(fd, &header); +} + static int perf_event_poll(int fd) { struct pollfd pfd = { .fd = fd, .events = POLLIN }; @@ -163,3 +168,41 @@ int perf_event_poller(int fd, perf_event_print_fn output_fn) return ret; } + +int perf_event_poller_multi(int *fds, struct perf_event_mmap_page **headers, + int num_fds, perf_event_print_fn output_fn) +{ + enum bpf_perf_event_ret ret; + struct pollfd *pfds; + void *buf = NULL; + size_t len = 0; + int i; + + pfds = malloc(sizeof(*pfds) * num_fds); + if (!pfds) + return -1; + + memset(pfds, 0, sizeof(*pfds) * num_fds); + for (i = 0; i < num_fds; i++) { + pfds[i].fd = fds[i]; + pfds[i].events = POLLIN; + } + + for (;;) { + poll(pfds, num_fds, 1000); + for (i = 0; i < num_fds; i++) { + if (pfds[i].revents) { + ret = bpf_perf_event_read_simple(headers[i], page_cnt * page_size, + page_size, &buf, &len, + bpf_perf_event_print, + output_fn); + if (ret != LIBBPF_PERF_EVENT_CONT) + break; + } + } + } + free(buf); + free(pfds); + + return ret; +} diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index 3b4bcf7f5084..18924f23db1b 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -3,6 +3,7 @@ #define __TRACE_HELPER_H #include +#include struct ksym { long addr; @@ -16,6 +17,9 @@ long ksym_get_addr(const char *name); typedef enum bpf_perf_event_ret (*perf_event_print_fn)(void *data, int size); int perf_event_mmap(int fd); +int perf_event_mmap_header(int fd, struct perf_event_mmap_page **header); /* return LIBBPF_PERF_EVENT_DONE or LIBBPF_PERF_EVENT_ERROR */ int perf_event_poller(int fd, perf_event_print_fn output_fn); +int perf_event_poller_multi(int *fds, struct perf_event_mmap_page **headers, + int num_fds, perf_event_print_fn output_fn); #endif From patchwork Mon Jun 4 16:33:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 925154 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=toke.dk Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; secure) header.d=toke.dk header.i=@toke.dk header.b="rBcY/Bwb"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4100rK24wcz9rvt for ; Tue, 5 Jun 2018 02:34:09 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751402AbeFDQeB (ORCPT ); Mon, 4 Jun 2018 12:34:01 -0400 Received: from mail.toke.dk ([52.28.52.200]:58057 "EHLO mail.toke.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751235AbeFDQeA (ORCPT ); Mon, 4 Jun 2018 12:34:00 -0400 Subject: [PATCH bpf-next v2 2/2] samples/bpf: Add xdp_sample_pkts example DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1528130037; bh=r8rpL4eKUEfDqyvUDG9jCCuLKimkiQc9NH0Z/8cX5sI=; h=Subject:From:To:Date:In-Reply-To:References:From; b=rBcY/BwbvCoJWpfHnJlVhUDzz4qBJEv4/7S5uEyQIbwmZnhR8n4iLOjYjgPkr3a7t 7Cb/iUxUxWjyQwctMWn7h9AXQzUO4YvynYWBJ8sRbibOxkuaYBjpNClSwhGWnD3css 3m/LwrC3Zha+KhugPBe9pDXEvsGADh/4jpA9C6JbYTe/tyEg2Axch60dDDeM/v5nRK wnUVgqrjMPAitd3RJBuV7weqAmJo/82UXTDIn8yrtmjdfogJZV8CJaPc/lOUDCmDnQ OKQAq25wHrDIIwr8bPW9gTh0wWmCtxaIOIsBzR4J4B3hOggHKAufYy5A9KA5sCI729 Ke4Lmoq/ZDHng== From: Toke =?utf-8?q?H=C3=B8iland-J=C3=B8rgensen?= To: netdev@vger.kernel.org Date: Mon, 04 Jun 2018 18:33:56 +0200 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <152813003614.3465.11049830599815911223.stgit@alrua-kau> In-Reply-To: <152813003609.3465.618891361534945522.stgit@alrua-kau> References: <152813003609.3465.618891361534945522.stgit@alrua-kau> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This adds an example program showing how to sample packets from XDP using the perf event buffer. The example userspace program just prints the ethernet header for every packet sampled. The example sets up a perf file descriptor per CPU, allowing the XDP program to pass BPF_F_CURRENT_CPU and work no matter which CPU handles the packet. Signed-off-by: Toke Høiland-Jørgensen --- samples/bpf/Makefile | 4 + samples/bpf/xdp_sample_pkts_kern.c | 62 ++++++++++++++ samples/bpf/xdp_sample_pkts_user.c | 162 ++++++++++++++++++++++++++++++++++++ 3 files changed, 228 insertions(+) create mode 100644 samples/bpf/xdp_sample_pkts_kern.c create mode 100644 samples/bpf/xdp_sample_pkts_user.c diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 1303af10e54d..6f0c6d276a86 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -52,6 +52,7 @@ hostprogs-y += xdp_adjust_tail hostprogs-y += xdpsock hostprogs-y += xdp_fwd hostprogs-y += task_fd_query +hostprogs-y += xdp_sample_pkts # Libbpf dependencies LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a @@ -107,6 +108,7 @@ xdp_adjust_tail-objs := xdp_adjust_tail_user.o xdpsock-objs := bpf_load.o xdpsock_user.o xdp_fwd-objs := bpf_load.o xdp_fwd_user.o task_fd_query-objs := bpf_load.o task_fd_query_user.o $(TRACE_HELPERS) +xdp_sample_pkts-objs := bpf_load.o xdp_sample_pkts_user.o $(TRACE_HELPERS) # Tell kbuild to always build the programs always := $(hostprogs-y) @@ -163,6 +165,7 @@ always += xdp_adjust_tail_kern.o always += xdpsock_kern.o always += xdp_fwd_kern.o always += task_fd_query_kern.o +always += xdp_sample_pkts_kern.o HOSTCFLAGS += -I$(objtree)/usr/include HOSTCFLAGS += -I$(srctree)/tools/lib/ @@ -179,6 +182,7 @@ HOSTCFLAGS_spintest_user.o += -I$(srctree)/tools/lib/bpf/ HOSTCFLAGS_trace_event_user.o += -I$(srctree)/tools/lib/bpf/ HOSTCFLAGS_sampleip_user.o += -I$(srctree)/tools/lib/bpf/ HOSTCFLAGS_task_fd_query_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_xdp_sample_pkts_user.o += -I$(srctree)/tools/lib/bpf/ HOST_LOADLIBES += $(LIBBPF) -lelf HOSTLOADLIBES_tracex4 += -lrt diff --git a/samples/bpf/xdp_sample_pkts_kern.c b/samples/bpf/xdp_sample_pkts_kern.c new file mode 100644 index 000000000000..4560522ca015 --- /dev/null +++ b/samples/bpf/xdp_sample_pkts_kern.c @@ -0,0 +1,62 @@ +#include +#include +#include +#include "bpf_helpers.h" + +#define SAMPLE_SIZE 64ul +#define MAX_CPUS 24 + +#define bpf_printk(fmt, ...) \ +({ \ + char ____fmt[] = fmt; \ + bpf_trace_printk(____fmt, sizeof(____fmt), \ + ##__VA_ARGS__); \ +}) + +struct bpf_map_def SEC("maps") my_map = { + .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(u32), + .max_entries = MAX_CPUS, +}; + +SEC("xdp_sample") +int xdp_sample_prog(struct xdp_md *ctx) +{ + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + + /* Metadata will be in the perf event before the packet data. */ + struct S { + u16 cookie; + u16 pkt_len; + } __attribute__((packed)) metadata; + + if (data + SAMPLE_SIZE < data_end) { + /* The XDP perf_event_output handler will use the upper 32 bits + * of the flags argument as a number of bytes to include of the + * packet payload in the event data. If the size is too big, the + * call to bpf_perf_event_output will fail and return -EFAULT. + * + * See bpf_xdp_event_output in net/core/filter.c. + * + * The BPF_F_CURRENT_CPU flag means that the event output fd + * will be indexed by the CPU number in the event map. + */ + u64 flags = (SAMPLE_SIZE << 32) | BPF_F_CURRENT_CPU; + int ret; + + metadata.cookie = 0xdead; + metadata.pkt_len = (u16)(data_end - data); + + ret = bpf_perf_event_output(ctx, &my_map, flags, + &metadata, sizeof(metadata)); + if(ret) + bpf_printk("perf_event_output failed: %d\n", ret); + } + + return XDP_PASS; +} + +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = LINUX_VERSION_CODE; diff --git a/samples/bpf/xdp_sample_pkts_user.c b/samples/bpf/xdp_sample_pkts_user.c new file mode 100644 index 000000000000..35c5dd953f48 --- /dev/null +++ b/samples/bpf/xdp_sample_pkts_user.c @@ -0,0 +1,162 @@ +/* This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "bpf_load.h" +#include "bpf_util.h" +#include + +#include "perf-sys.h" +#include "trace_helpers.h" + +#define MAX_CPUS 24 +static int pmu_fds[MAX_CPUS], if_idx = 0; +static struct perf_event_mmap_page *headers[MAX_CPUS]; +static char *if_name; + +static int do_attach(int idx, int fd, const char *name) +{ + int err; + + err = bpf_set_link_xdp_fd(idx, fd, 0); + if (err < 0) + printf("ERROR: failed to attach program to %s\n", name); + + return err; +} + +static int do_detach(int idx, const char *name) +{ + int err; + + err = bpf_set_link_xdp_fd(idx, -1, 0); + if (err < 0) + printf("ERROR: failed to detach program from %s\n", name); + + return err; +} + +#define SAMPLE_SIZE 64 + +static int print_bpf_output(void *data, int size) +{ + struct { + __u16 cookie; + __u16 pkt_len; + __u8 pkt_data[SAMPLE_SIZE]; + } __attribute__((packed)) *e = data; + int i; + + if (e->cookie != 0xdead) { + printf("BUG cookie %x sized %d\n", + e->cookie, size); + return LIBBPF_PERF_EVENT_ERROR; + } + + printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len); + for (i = 0; i < 14 && i < e->pkt_len; i++) + printf("%02x ", e->pkt_data[i]); + printf("\n"); + + return LIBBPF_PERF_EVENT_CONT; +} + +static void test_bpf_perf_event(int num) +{ + struct perf_event_attr attr = { + .sample_type = PERF_SAMPLE_RAW, + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_BPF_OUTPUT, + .wakeup_events = 1, /* get an fd notification for every event */ + }; + int i; + + for (i = 0; i < num; i++) { + int key = i; + + pmu_fds[i] = sys_perf_event_open(&attr, -1/*pid*/, i/*cpu*/, -1/*group_fd*/, 0); + + assert(pmu_fds[i] >= 0); + assert(bpf_map_update_elem(map_fd[0], &key, &pmu_fds[i], BPF_ANY) == 0); + ioctl(pmu_fds[i], PERF_EVENT_IOC_ENABLE, 0); + } +} + +static void sig_handler(int signo) +{ + do_detach(if_idx, if_name); + exit(0); +} + +int main(int argc, char **argv) +{ + char filename[256]; + int ret, err; + int numcpus; + int i; + + if (argc < 2) { + printf("Usage: %s \n", argv[0]); + return 1; + } + + numcpus = get_nprocs(); + if (numcpus > MAX_CPUS) + numcpus = MAX_CPUS; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + + if (load_bpf_file(filename)) { + printf("%s", bpf_log_buf); + return 1; + } + + if_idx = if_nametoindex(argv[1]); + if (!if_idx) + if_idx = strtoul(argv[1], NULL, 0); + + if (!if_idx) { + fprintf(stderr, "Invalid ifname\n"); + return 1; + } + if_name = argv[1]; + err = do_attach(if_idx, prog_fd[0], argv[1]); + if (err) + return err; + + if (signal(SIGINT, sig_handler) || + signal(SIGHUP, sig_handler) || + signal(SIGTERM, sig_handler)) { + perror("signal"); + return 1; + } + + test_bpf_perf_event(numcpus); + + for (i = 0; i < numcpus; i++) + if (perf_event_mmap_header(pmu_fds[i], &headers[i]) < 0) + return 1; + + ret = perf_event_poller_multi(pmu_fds, headers, numcpus, print_bpf_output); + kill(0, SIGINT); + return ret; +}