From 04949ccc273e14d28aa004ac6954af0898ca3d12 Mon Sep 17 00:00:00 2001 From: "Daniel T. Lee" Date: Tue, 13 Aug 2019 11:46:18 +0900 Subject: [PATCH] tools: bpftool: add net attach command to attach XDP on interface By this commit, using `bpftool net attach`, user can attach XDP prog on interface. New type of enum 'net_attach_type' has been made, as stat ted at cover-letter, the meaning of 'attach' is, prog will be attached on interface. With 'overwrite' option at argument, attached XDP program could be replaced. Added new helper 'net_parse_dev' to parse the network device at argument. BPF prog will be attached through libbpf 'bpf_set_link_xdp_fd'. Acked-by: Yonghong Song Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/net.c | 136 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 129 insertions(+), 7 deletions(-) diff --git a/tools/bpf/bpftool/net.c b/tools/bpf/bpftool/net.c index 67e99c56bc88..33222ca1060e 100644 --- a/tools/bpf/bpftool/net.c +++ b/tools/bpf/bpftool/net.c @@ -55,6 +55,35 @@ struct bpf_attach_info { __u32 flow_dissector_id; }; +enum net_attach_type { + NET_ATTACH_TYPE_XDP, + NET_ATTACH_TYPE_XDP_GENERIC, + NET_ATTACH_TYPE_XDP_DRIVER, + NET_ATTACH_TYPE_XDP_OFFLOAD, +}; + +static const char * const attach_type_strings[] = { + [NET_ATTACH_TYPE_XDP] = "xdp", + [NET_ATTACH_TYPE_XDP_GENERIC] = "xdpgeneric", + [NET_ATTACH_TYPE_XDP_DRIVER] = "xdpdrv", + [NET_ATTACH_TYPE_XDP_OFFLOAD] = "xdpoffload", +}; + +const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings); + +static enum net_attach_type parse_attach_type(const char *str) +{ + enum net_attach_type type; + + for (type = 0; type < net_attach_type_size; type++) { + if (attach_type_strings[type] && + is_prefix(str, attach_type_strings[type])) + return type; + } + + return net_attach_type_size; +} + static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb) { struct bpf_netdev_t *netinfo = cookie; @@ -223,6 +252,97 @@ static int query_flow_dissector(struct bpf_attach_info *attach_info) return 0; } +static int net_parse_dev(int *argc, char ***argv) +{ + int ifindex; + + if (is_prefix(**argv, "dev")) { + NEXT_ARGP(); + + ifindex = if_nametoindex(**argv); + if (!ifindex) + p_err("invalid devname %s", **argv); + + NEXT_ARGP(); + } else { + p_err("expected 'dev', got: '%s'?", **argv); + return -1; + } + + return ifindex; +} + +static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type, + int ifindex, bool overwrite) +{ + __u32 flags = 0; + + if (!overwrite) + flags = XDP_FLAGS_UPDATE_IF_NOEXIST; + if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC) + flags |= XDP_FLAGS_SKB_MODE; + if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER) + flags |= XDP_FLAGS_DRV_MODE; + if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD) + flags |= XDP_FLAGS_HW_MODE; + + return bpf_set_link_xdp_fd(ifindex, progfd, flags); +} + +static int do_attach(int argc, char **argv) +{ + enum net_attach_type attach_type; + int progfd, ifindex, err = 0; + bool overwrite = false; + + /* parse attach args */ + if (!REQ_ARGS(5)) + return -EINVAL; + + attach_type = parse_attach_type(*argv); + if (attach_type == net_attach_type_size) { + p_err("invalid net attach/detach type: %s", *argv); + return -EINVAL; + } + NEXT_ARG(); + + progfd = prog_parse_fd(&argc, &argv); + if (progfd < 0) + return -EINVAL; + + ifindex = net_parse_dev(&argc, &argv); + if (ifindex < 1) { + close(progfd); + return -EINVAL; + } + + if (argc) { + if (is_prefix(*argv, "overwrite")) { + overwrite = true; + } else { + p_err("expected 'overwrite', got: '%s'?", *argv); + close(progfd); + return -EINVAL; + } + } + + /* attach xdp prog */ + if (is_prefix("xdp", attach_type_strings[attach_type])) + err = do_attach_detach_xdp(progfd, attach_type, ifindex, + overwrite); + + if (err < 0) { + p_err("interface %s attach failed: %s", + attach_type_strings[attach_type], strerror(-err)); + return err; + } + + if (json_output) + jsonw_null(json_wtr); + + return 0; +} + static int do_show(int argc, char **argv) { struct bpf_attach_info attach_info = {}; @@ -232,13 +352,9 @@ static int do_show(int argc, char **argv) char err_buf[256]; if (argc == 2) { - if (strcmp(argv[0], "dev") != 0) - usage(); - filter_idx = if_nametoindex(argv[1]); - if (filter_idx == 0) { - fprintf(stderr, "invalid dev name %s\n", argv[1]); + filter_idx = net_parse_dev(&argc, &argv); + if (filter_idx < 1) return -1; - } } else if (argc != 0) { usage(); } @@ -305,13 +421,18 @@ static int do_help(int argc, char **argv) fprintf(stderr, "Usage: %s %s { show | list } [dev ]\n" + " %s %s attach ATTACH_TYPE PROG dev [ overwrite ]\n" " %s %s help\n" + "\n" + " " HELP_SPEC_PROGRAM "\n" + " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n" + "\n" "Note: Only xdp and tc attachments are supported now.\n" " For progs attached to cgroups, use \"bpftool cgroup\"\n" " to dump program attachments. For program types\n" " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n" " consult iproute2.\n", - bin_name, argv[-2], bin_name, argv[-2]); + bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]); return 0; } @@ -319,6 +440,7 @@ static int do_help(int argc, char **argv) static const struct cmd cmds[] = { { "show", do_show }, { "list", do_show }, + { "attach", do_attach }, { "help", do_help }, { 0 } };