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 stated at cover-letter, the meaning of 'attach' is, prog will be attached on interface.
BPF prog will be attached through libbpf 'bpf_set_link_xdp_fd'. Signed-off-by: Daniel T. Lee <danieltim...@gmail.com> --- Changes in v2: - command 'load' changed to 'attach' for the consistency - 'NET_ATTACH_TYPE_XDP_DRIVE' changed to 'NET_ATTACH_TYPE_XDP_DRIVER' tools/bpf/bpftool/net.c | 107 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 106 insertions(+), 1 deletion(-) diff --git a/tools/bpf/bpftool/net.c b/tools/bpf/bpftool/net.c index 67e99c56bc88..f3b57660b303 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, + __MAX_NET_ATTACH_TYPE +}; + +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", + [__MAX_NET_ATTACH_TYPE] = NULL, +}; + +static enum net_attach_type parse_attach_type(const char *str) +{ + enum net_attach_type type; + + for (type = 0; type < __MAX_NET_ATTACH_TYPE; type++) { + if (attach_type_strings[type] && + is_prefix(str, attach_type_strings[type])) + return type; + } + + return __MAX_NET_ATTACH_TYPE; +} + static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb) { struct bpf_netdev_t *netinfo = cookie; @@ -223,6 +252,77 @@ static int query_flow_dissector(struct bpf_attach_info *attach_info) return 0; } +static int parse_attach_args(int argc, char **argv, int *progfd, + enum net_attach_type *attach_type, int *ifindex) +{ + if (!REQ_ARGS(3)) + return -EINVAL; + + *progfd = prog_parse_fd(&argc, &argv); + if (*progfd < 0) + return *progfd; + + *attach_type = parse_attach_type(*argv); + if (*attach_type == __MAX_NET_ATTACH_TYPE) { + p_err("invalid net attach/detach type"); + return -EINVAL; + } + + NEXT_ARG(); + if (!REQ_ARGS(1)) + return -EINVAL; + + *ifindex = if_nametoindex(*argv); + if (!*ifindex) { + p_err("Invalid ifname"); + return -EINVAL; + } + + return 0; +} + +static int do_attach_detach_xdp(int *progfd, enum net_attach_type *attach_type, + int *ifindex) +{ + __u32 flags; + int err; + + 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; + + err = bpf_set_link_xdp_fd(*ifindex, *progfd, flags); + + return err; +} + +static int do_attach(int argc, char **argv) +{ + enum net_attach_type attach_type; + int err, progfd, ifindex; + + err = parse_attach_args(argc, argv, &progfd, &attach_type, &ifindex); + if (err) + return err; + + if (is_prefix("xdp", attach_type_strings[attach_type])) + err = do_attach_detach_xdp(&progfd, &attach_type, &ifindex); + + if (err < 0) { + p_err("link set %s failed", attach_type_strings[attach_type]); + return -1; + } + + if (json_output) + jsonw_null(json_wtr); + + return 0; +} + static int do_show(int argc, char **argv) { struct bpf_attach_info attach_info = {}; @@ -305,13 +405,17 @@ static int do_help(int argc, char **argv) fprintf(stderr, "Usage: %s %s { show | list } [dev <devname>]\n" + " %s %s attach PROG LOAD_TYPE <devname>\n" " %s %s help\n" + "\n" + " " HELP_SPEC_PROGRAM "\n" + " LOAD_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\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 +423,7 @@ 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 } }; -- 2.20.1