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tools: bpftool: add net attach command to attach XDP on interface

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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 <yhs@fb.com>
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Daniel T. Lee 2019-08-13 11:46:18 +09:00 committed by Alexei Starovoitov
parent a9436dca11
commit 04949ccc27
1 changed files with 129 additions and 7 deletions
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136
tools/bpf/bpftool/net.c
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@ -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 <devname>]\n"
" %s %s attach ATTACH_TYPE PROG dev <devname> [ 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 }
};