1xdp-loader(8) XDP program loader xdp-loader(8)
2
6 XDP-loader is a simple loader for XDP programs with support for attach‐
7 ing multiple programs to the same interface. To achieve this it exposes
8 the same load and unload semantics exposed by the libxdp library.
9 Running xdp-loader
13 The syntax for running xdp-loader is:
14 xdp-loader COMMAND [options]
16 Where COMMAND can be one of:
18 load - load an XDP program on an interface
19 unload - unload an XDP program from an interface
20 status - show current XDP program status
21 clean - clean up detached program links in XDP bpffs directory
22 help - show the list of available commands
23 Each command, and its options are explained below. Or use xdp-loader
26 COMMAND --help to see the options for each command.
27
30 The load command loads one or more XDP programs onto an interface.
31 The syntax for the load command is:
34 xdp-loader load [options] <ifname> <programs>
37 Where <ifname> is the name of the interface to load the programs onto,
40 and the <programs> is one or more file names containing XDP programs.
41 The programs will be loaded onto the interface in the order of their
42 preference, as specified by the program metadata (see libxdp(3)).
43 The supported options are:
46 -m, --mode <mode>
49 Specifies which mode to load the XDP program to be loaded in. The valid
50 values are 'native', which is the default in-driver XDP mode, 'skb',
51 which causes the so-called skb mode (also known as generic XDP) to be
52 used, 'hw' which causes the program to be offloaded to the hardware, or
53 'unspecified' which leaves it up to the kernel to pick a mode (which it
54 will do by picking native mode if the driver supports it, or generic
55 mode otherwise). Note that using 'unspecified' can make it difficult to
56 predict what mode a program will end up being loaded in. For this rea‐
57 son, the default is 'native'.
58 -p, --pin-path <path>
61 This specifies a root path under which to pin any maps that define the
62 'pinning' attribute in their definitions. This path must be located on
63 a bpffs file system. If not set, maps will not be pinned, even if they
64 specify pinning in their definitions. When pinning maps, if the pinned
65 location for a map already exist, the map pinned there will be reused
66 if it is compatible with the type of the map being loaded.
67 -s, --section <section>
70 Specify which ELF section to load the XDP program(s) from in each file.
71 The default is to use the first program in each file. If this option is
72 set, it applies to all programs being loaded.
73 -v, --verbose
76 Enable debug logging. Specify twice for even more verbosity.
77 -h, --help
80 Display a summary of the available options
81
84 The unload command is used for unloading programs from an interface.
85 The syntax for the unload command is:
88 xdp-loader unload [options] <ifname>
91 Where <ifname> is the name of the interface to load the programs onto.
94 Either the --all or --id options must be used to specify which pro‐
95 gram(s) to unload.
96 The supported options are:
99 -i, --id <id>
102 Unload a single program from the interface by ID. Use xdp-loader status
103 to obtain the ID of the program being unloaded. If this program is the
104 last program loaded on the interface, the dispatcher program will also
105 be removed, which makes the operation equivalent to specifying --all.
106 -a, --all
109 Unload all XDP programs on the interface, as well as the multi-program
110 dispatcher.
111 -v, --verbose
114 Enable debug logging. Specify twice for even more verbosity.
115 -h, --help
118 Display a summary of the available options
119
122 The status command displays a list of interfaces in the system, and the
123 XDP program(s) loaded on each interface. For each interface, a list of
124 programs are shown, with the run priority and "chain actions" for each
125 program. See the section on program metadata for the meaning of this
126 metadata.
127 -v, --verbose
130 Enable debug logging. Specify twice for even more verbosity.
131 -h, --help
134 Display a summary of the available options
135
138 The syntax for the clean command is:
139 xdp-loader clean [options] [ifname]
142 The clean command cleans up any detached program links in the XDP bpffs
145 directory. When a network interface disappears, any programs loaded in
146 software mode (e.g. skb, native) remain pinned in the bpffs directory,
147 but become detached from the interface. These need to be unlinked from
148 the filesystem. The clean command takes an optional interface parameter
149 to only unlink detached programs corresponding to the interface. By
150 default, all detached programs for all interfaces are unlinked.
151 The supported options are:
154 -v, --verbose
157 Enable debug logging. Specify twice for even more verbosity.
158 -h, --help
161 Display a summary of the available options
162
165 To load an XDP program on the eth0 interface simply do:
166 # xdp-loader load eth0 xdp_drop.o
168 # xdp-loader status
169 CURRENT XDP PROGRAM STATUS:
171 Interface Prio Program name Mode ID Tag Chain actions
173 -------------------------------------------------------------------------------------
174 lo <no XDP program>
175 eth0 xdp_dispatcher native 50 d51e469e988d81da
176 => 50 xdp_drop 55 57cd311f2e27366b XDP_PASS
177 Which shows that a dispatcher program was loaded on the interface, and
181 the xdp_drop program was installed as the first (and only) component
182 program after it. In this instance, the program does not specify any of
183 the metadata above, so the defaults (priority 50 and XDP_PASS as its
184 chain call action) was used.
185 To use the automatic map pinning, include the pinning attribute into
188 the map definition in the program, something like:
189 struct {
191 __uint(type, BPF_MAP_TYPE_ARRAY);
192 __uint(max_entries, 10);
193 __type(key, __u32);
194 __type(value, __u64);
195 __uint(pinning, LIBBPF_PIN_BY_NAME);
196 } my_map SEC(".maps");
197 And load it with the --pin-path attribute:
200 # xdp-loader load eth0 my_prog.o --pin-path /sys/fs/bpf/my-prog
202 This will pin the map at /sys/fs/bpf/my-prog/my_map. If this already
205 exists, the pinned map will be reused instead of creating a new one,
206 which allows different BPF programs to share the map.
207
210 Please report any bugs on Github: https://github.com/xdp-project/xdp-
211 tools/issues
212
215 xdp-loader and this man page were written by Toke Høiland-Jørgensen.
216V1.2.0 JULY 24, 2021 xdp-loader(8)