From patchwork Tue Dec 8 08:18:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hangbin Liu X-Patchwork-Id: 11957915 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93A6DC4361B for ; Tue, 8 Dec 2020 08:19:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56BE523A60 for ; Tue, 8 Dec 2020 08:19:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727679AbgLHITw (ORCPT ); Tue, 8 Dec 2020 03:19:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726734AbgLHITv (ORCPT ); Tue, 8 Dec 2020 03:19:51 -0500 Received: from mail-pg1-x532.google.com (mail-pg1-x532.google.com [IPv6:2607:f8b0:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BB58C061749; Tue, 8 Dec 2020 00:19:11 -0800 (PST) Received: by mail-pg1-x532.google.com with SMTP id o4so11526409pgj.0; Tue, 08 Dec 2020 00:19:11 -0800 (PST) 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=e23pcXpl81f9+8bBMnQygIfjx34O4wrGjsXlxS/VveY=; b=t682N+qfb9ajpsOoomOz9THNzaJ9fq9rC9T6b6UbzZ5H+N5xQbGvDtvGzFRQKes6TS Na+W98hiHl2Vy6DJ2x7FTRE7vN7+7uMUy/JOUyBGrBJwaB8/w9oLN8AzgzHjGnVOS0B7 0+FdAoTWoS8jHpMn+VKSz8eeOauwfFxi3u93gHTjnhC1hp7p+jtmwAsSe0JGSspRY2AD W3XkfLw4Uf9L7W5L28VrPslnWNaBIRZJyPCQ2wQiBmsckRsFCJZpsXcSrel62gUXDUbl kzuTpWx9SC7kr+8UqNKtSzb08dTFYC9kR4FMv4VIIqbY/ozlIias6IGFk0mvXbAT5AWG qfsA== 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=e23pcXpl81f9+8bBMnQygIfjx34O4wrGjsXlxS/VveY=; b=di1LuzA/umnnzkG4dP59Mklz+T/d3VsPj6o2I9PcnPWqaJH3n+ht+hZSjsciexKRiK pyTS+6rXuCmGhnny5FTEjve78K60JpxpiYl+Q67XexS/vmNkmnAEp2/jMI4pwl6go+Jr LksqabobYmAnLdc/UbwQPK11IQP7L3d9GdnLAu7RXH85ld2TlH80qQ3nhAg7QK13F7nB cdVd8UVdqtjRPrBF/jXS7+XIlaDyREkLFbX5wEYpevSHC9L5RAxUZoiFwYF0fjIYhY4Y cjQAaSMMggNpUZLtMb+xSpTSYhs2MzODlHmcUmcBCJGhh73eA0rmOnPrr5l3G1Bw/pHv rsuQ== X-Gm-Message-State: AOAM533hClegNE50mxvUpdeReP9ztcuCAOKTDcxqeKXyAxzfcA8Wg3yk a4/OVP0HekY74CwvQSegkMYrNg+hmcNuMG0F X-Google-Smtp-Source: ABdhPJwDjMVgQMLkQVC6Adc34cq56xrca/nmwtv1cPyKOB3yAiSFHF4Hfi9XmpXus5MVsYuDRDbP+Q== X-Received: by 2002:a05:6a00:2382:b029:198:15a2:aaf9 with SMTP id f2-20020a056a002382b029019815a2aaf9mr19433912pfc.39.1607415550609; Tue, 08 Dec 2020 00:19:10 -0800 (PST) Received: from localhost.localdomain.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id y188sm17020594pfy.98.2020.12.08.00.19.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Dec 2020 00:19:10 -0800 (PST) From: Hangbin Liu To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Yonghong Song , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Hangbin Liu Subject: [PATCHv3 bpf-next] samples/bpf: add xdp program on egress for xdp_redirect_map Date: Tue, 8 Dec 2020 16:18:56 +0800 Message-Id: <20201208081856.1627657-1-liuhangbin@gmail.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201126084325.477470-1-liuhangbin@gmail.com> References: <20201126084325.477470-1-liuhangbin@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This patch add a xdp program on egress to show that we can modify the packet on egress. In this sample we will set the pkt's src mac to egress's mac address. The xdp_prog will be attached when -X option supplied. Signed-off-by: Hangbin Liu --- v3: a) modify the src mac address based on egress mac v2: a) use pkt counter instead of IP ttl modification on egress program b) make the egress program selectable by option -X --- samples/bpf/xdp_redirect_map_kern.c | 60 ++++++++++- samples/bpf/xdp_redirect_map_user.c | 153 ++++++++++++++++++++-------- 2 files changed, 168 insertions(+), 45 deletions(-) diff --git a/samples/bpf/xdp_redirect_map_kern.c b/samples/bpf/xdp_redirect_map_kern.c index 6489352ab7a4..6b2164722649 100644 --- a/samples/bpf/xdp_redirect_map_kern.c +++ b/samples/bpf/xdp_redirect_map_kern.c @@ -19,12 +19,22 @@ #include #include +/* The 2nd xdp prog on egress does not support skb mode, so we define two + * maps, tx_port_general and tx_port_native. + */ struct { __uint(type, BPF_MAP_TYPE_DEVMAP); __uint(key_size, sizeof(int)); __uint(value_size, sizeof(int)); __uint(max_entries, 100); -} tx_port SEC(".maps"); +} tx_port_general SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_DEVMAP); + __uint(key_size, sizeof(int)); + __uint(value_size, sizeof(struct bpf_devmap_val)); + __uint(max_entries, 100); +} tx_port_native SEC(".maps"); /* Count RX packets, as XDP bpf_prog doesn't get direct TX-success * feedback. Redirect TX errors can be caught via a tracepoint. @@ -36,6 +46,14 @@ struct { __uint(max_entries, 1); } rxcnt SEC(".maps"); +/* map to stroe egress interface mac address */ +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, u32); + __type(value, __be64); + __uint(max_entries, 1); +} tx_mac SEC(".maps"); + static void swap_src_dst_mac(void *data) { unsigned short *p = data; @@ -52,17 +70,16 @@ static void swap_src_dst_mac(void *data) p[5] = dst[2]; } -SEC("xdp_redirect_map") -int xdp_redirect_map_prog(struct xdp_md *ctx) +static int xdp_redirect_map(struct xdp_md *ctx, void *redirect_map) { void *data_end = (void *)(long)ctx->data_end; void *data = (void *)(long)ctx->data; struct ethhdr *eth = data; int rc = XDP_DROP; - int vport, port = 0, m = 0; long *value; u32 key = 0; u64 nh_off; + int vport; nh_off = sizeof(*eth); if (data + nh_off > data_end) @@ -79,7 +96,40 @@ int xdp_redirect_map_prog(struct xdp_md *ctx) swap_src_dst_mac(data); /* send packet out physical port */ - return bpf_redirect_map(&tx_port, vport, 0); + return bpf_redirect_map(redirect_map, vport, 0); +} + +SEC("xdp_redirect_general") +int xdp_redirect_map_general(struct xdp_md *ctx) +{ + return xdp_redirect_map(ctx, &tx_port_general); +} + +SEC("xdp_redirect_native") +int xdp_redirect_map_native(struct xdp_md *ctx) +{ + return xdp_redirect_map(ctx, &tx_port_native); +} + +SEC("xdp_devmap/map_prog") +int xdp_redirect_map_egress(struct xdp_md *ctx) +{ + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + struct ethhdr *eth = data; + __be64 *mac; + u32 key = 0; + u64 nh_off; + + nh_off = sizeof(*eth); + if (data + nh_off > data_end) + return XDP_DROP; + + mac = bpf_map_lookup_elem(&tx_mac, &key); + if (mac) + __builtin_memcpy(eth->h_source, mac, ETH_ALEN); + + return XDP_PASS; } /* Redirect require an XDP bpf_prog loaded on the TX device */ diff --git a/samples/bpf/xdp_redirect_map_user.c b/samples/bpf/xdp_redirect_map_user.c index 31131b6e7782..19636045c8dc 100644 --- a/samples/bpf/xdp_redirect_map_user.c +++ b/samples/bpf/xdp_redirect_map_user.c @@ -14,6 +14,10 @@ #include #include #include +#include +#include +#include +#include #include "bpf_util.h" #include @@ -21,7 +25,8 @@ static int ifindex_in; static int ifindex_out; -static bool ifindex_out_xdp_dummy_attached = true; +static bool ifindex_out_xdp_dummy_attached = false; +static bool xdp_devmap_attached = false; static __u32 prog_id; static __u32 dummy_prog_id; @@ -83,6 +88,29 @@ static void poll_stats(int interval, int ifindex) } } +static int get_mac_addr(unsigned int ifindex_out, void *mac_addr) +{ + struct ifreq ifr; + char ifname[IF_NAMESIZE]; + int fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); + + if (fd < 0) + return -1; + + if (!if_indextoname(ifindex_out, ifname)) + return -1; + + strcpy(ifr.ifr_name, ifname); + + if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0) + return -1; + + memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char)); + close(fd); + + return 0; +} + static void usage(const char *prog) { fprintf(stderr, @@ -90,24 +118,26 @@ static void usage(const char *prog) "OPTS:\n" " -S use skb-mode\n" " -N enforce native mode\n" - " -F force loading prog\n", + " -F force loading prog\n" + " -X load xdp program on egress\n", prog); } int main(int argc, char **argv) { struct bpf_prog_load_attr prog_load_attr = { - .prog_type = BPF_PROG_TYPE_XDP, + .prog_type = BPF_PROG_TYPE_UNSPEC, }; - struct bpf_program *prog, *dummy_prog; + struct bpf_program *prog, *dummy_prog, *devmap_prog; + int prog_fd, dummy_prog_fd, devmap_prog_fd = -1; + int tx_port_map_fd, tx_mac_map_fd; + struct bpf_devmap_val devmap_val; struct bpf_prog_info info = {}; __u32 info_len = sizeof(info); - int prog_fd, dummy_prog_fd; - const char *optstr = "FSN"; + const char *optstr = "FSNX"; struct bpf_object *obj; int ret, opt, key = 0; char filename[256]; - int tx_port_map_fd; while ((opt = getopt(argc, argv, optstr)) != -1) { switch (opt) { @@ -120,6 +150,9 @@ int main(int argc, char **argv) case 'F': xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST; break; + case 'X': + xdp_devmap_attached = true; + break; default: usage(basename(argv[0])); return 1; @@ -150,67 +183,107 @@ int main(int argc, char **argv) if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)) return 1; - prog = bpf_program__next(NULL, obj); - dummy_prog = bpf_program__next(prog, obj); - if (!prog || !dummy_prog) { - printf("finding a prog in obj file failed\n"); - return 1; + if (xdp_flags & XDP_FLAGS_SKB_MODE) { + prog = bpf_object__find_program_by_title(obj, "xdp_redirect_general"); + tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port_general"); + } else { + prog = bpf_object__find_program_by_title(obj, "xdp_redirect_native"); + tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port_native"); } - /* bpf_prog_load_xattr gives us the pointer to first prog's fd, - * so we're missing only the fd for dummy prog - */ - dummy_prog_fd = bpf_program__fd(dummy_prog); - if (prog_fd < 0 || dummy_prog_fd < 0) { - printf("bpf_prog_load_xattr: %s\n", strerror(errno)); - return 1; + prog_fd = bpf_program__fd(prog); + if (!prog || prog_fd < 0 || tx_port_map_fd < 0) { + printf("finding prog/tx_port_map in obj file failed\n"); + goto out; } - tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port"); rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt"); - if (tx_port_map_fd < 0 || rxcnt_map_fd < 0) { + tx_mac_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_mac"); + if (rxcnt_map_fd < 0 || tx_mac_map_fd < 0) { printf("bpf_object__find_map_fd_by_name failed\n"); - return 1; + goto out; } if (bpf_set_link_xdp_fd(ifindex_in, prog_fd, xdp_flags) < 0) { printf("ERROR: link set xdp fd failed on %d\n", ifindex_in); - return 1; + goto out; } ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len); if (ret) { printf("can't get prog info - %s\n", strerror(errno)); - return ret; + goto out; } prog_id = info.id; - /* Loading dummy XDP prog on out-device */ - if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd, - (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) { - printf("WARN: link set xdp fd failed on %d\n", ifindex_out); - ifindex_out_xdp_dummy_attached = false; - } + /* If -X supplied, load 2nd xdp prog on egress. + * If not, just load dummy prog on egress. + */ + if (xdp_devmap_attached) { + unsigned char mac_addr[6]; - memset(&info, 0, sizeof(info)); - ret = bpf_obj_get_info_by_fd(dummy_prog_fd, &info, &info_len); - if (ret) { - printf("can't get prog info - %s\n", strerror(errno)); - return ret; + devmap_prog = bpf_object__find_program_by_title(obj, "xdp_devmap/map_prog"); + if (!devmap_prog) { + printf("finding devmap_prog in obj file failed\n"); + goto out; + } + devmap_prog_fd = bpf_program__fd(devmap_prog); + if (devmap_prog_fd < 0) { + printf("finding devmap_prog fd failed\n"); + goto out; + } + + if (get_mac_addr(ifindex_out, mac_addr) < 0) { + printf("get interface %d mac failed\n", ifindex_out); + goto out; + } + + ret = bpf_map_update_elem(tx_mac_map_fd, &key, mac_addr, 0); + if (ret) { + perror("bpf_update_elem tx_mac_map_fd"); + goto out; + } + } else if (ifindex_in != ifindex_out) { + dummy_prog = bpf_object__find_program_by_title(obj, "xdp_redirect_dummy"); + if (!dummy_prog) { + printf("finding dummy_prog in obj file failed\n"); + goto out; + } + + dummy_prog_fd = bpf_program__fd(dummy_prog); + if (dummy_prog_fd < 0) { + printf("find dummy_prog fd failed\n"); + goto out; + } + + if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd, + (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) == 0) { + ifindex_out_xdp_dummy_attached = true; + } else { + printf("WARN: link set xdp fd failed on %d\n", ifindex_out); + } + + memset(&info, 0, sizeof(info)); + ret = bpf_obj_get_info_by_fd(dummy_prog_fd, &info, &info_len); + if (ret) { + printf("can't get prog info - %s\n", strerror(errno)); + } + dummy_prog_id = info.id; } - dummy_prog_id = info.id; signal(SIGINT, int_exit); signal(SIGTERM, int_exit); - /* populate virtual to physical port map */ - ret = bpf_map_update_elem(tx_port_map_fd, &key, &ifindex_out, 0); + devmap_val.ifindex = ifindex_out; + devmap_val.bpf_prog.fd = devmap_prog_fd; + ret = bpf_map_update_elem(tx_port_map_fd, &key, &devmap_val, 0); if (ret) { - perror("bpf_update_elem"); + perror("bpf_update_elem tx_port_map_fd"); goto out; } poll_stats(2, ifindex_out); out: - return 0; + bpf_object__close(obj); + return 1; }