1================ 2bpftool-map 3================ 4------------------------------------------------------------------------------- 5tool for inspection and simple manipulation of eBPF maps 6------------------------------------------------------------------------------- 7 8:Manual section: 8 9 10SYNOPSIS 11======== 12 13 **bpftool** [*OPTIONS*] **map** *COMMAND* 14 15 *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-f** | **--bpffs** } } 16 17 *COMMANDS* := 18 { **show** | **list** | **create** | **dump** | **update** | **lookup** | **getnext** 19 | **delete** | **pin** | **help** } 20 21MAP COMMANDS 22============= 23 24| **bpftool** **map { show | list }** [*MAP*] 25| **bpftool** **map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \ 26| **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*] 27| **bpftool** **map dump** *MAP* 28| **bpftool** **map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*] 29| **bpftool** **map lookup** *MAP* **key** *DATA* 30| **bpftool** **map getnext** *MAP* [**key** *DATA*] 31| **bpftool** **map delete** *MAP* **key** *DATA* 32| **bpftool** **map pin** *MAP* *FILE* 33| **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*] 34| **bpftool** **map help** 35| 36| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } 37| *DATA* := { [**hex**] *BYTES* } 38| *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* } 39| *VALUE* := { *DATA* | *MAP* | *PROG* } 40| *UPDATE_FLAGS* := { **any** | **exist** | **noexist** } 41| *TYPE* := { **hash** | **array** | **prog_array** | **perf_event_array** | **percpu_hash** 42| | **percpu_array** | **stack_trace** | **cgroup_array** | **lru_hash** 43| | **lru_percpu_hash** | **lpm_trie** | **array_of_maps** | **hash_of_maps** 44| | **devmap** | **sockmap** | **cpumap** | **xskmap** | **sockhash** 45| | **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage** } 46 47DESCRIPTION 48=========== 49 **bpftool map { show | list }** [*MAP*] 50 Show information about loaded maps. If *MAP* is specified 51 show information only about given map, otherwise list all 52 maps currently loaded on the system. 53 54 Output will start with map ID followed by map type and 55 zero or more named attributes (depending on kernel version). 56 57 **bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*] 58 Create a new map with given parameters and pin it to *bpffs* 59 as *FILE*. 60 61 **bpftool map dump** *MAP* 62 Dump all entries in a given *MAP*. 63 64 **bpftool map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*] 65 Update map entry for a given *KEY*. 66 67 *UPDATE_FLAGS* can be one of: **any** update existing entry 68 or add if doesn't exit; **exist** update only if entry already 69 exists; **noexist** update only if entry doesn't exist. 70 71 If the **hex** keyword is provided in front of the bytes 72 sequence, the bytes are parsed as hexadeximal values, even if 73 no "0x" prefix is added. If the keyword is not provided, then 74 the bytes are parsed as decimal values, unless a "0x" prefix 75 (for hexadecimal) or a "0" prefix (for octal) is provided. 76 77 **bpftool map lookup** *MAP* **key** *DATA* 78 Lookup **key** in the map. 79 80 **bpftool map getnext** *MAP* [**key** *DATA*] 81 Get next key. If *key* is not specified, get first key. 82 83 **bpftool map delete** *MAP* **key** *DATA* 84 Remove entry from the map. 85 86 **bpftool map pin** *MAP* *FILE* 87 Pin map *MAP* as *FILE*. 88 89 Note: *FILE* must be located in *bpffs* mount. 90 91 **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*] 92 Read events from a BPF_MAP_TYPE_PERF_EVENT_ARRAY map. 93 94 Install perf rings into a perf event array map and dump 95 output of any bpf_perf_event_output() call in the kernel. 96 By default read the number of CPUs on the system and 97 install perf ring for each CPU in the corresponding index 98 in the array. 99 100 If **cpu** and **index** are specified, install perf ring 101 for given **cpu** at **index** in the array (single ring). 102 103 Note that installing a perf ring into an array will silently 104 replace any existing ring. Any other application will stop 105 receiving events if it installed its rings earlier. 106 107 **bpftool map help** 108 Print short help message. 109 110OPTIONS 111======= 112 -h, --help 113 Print short generic help message (similar to **bpftool help**). 114 115 -v, --version 116 Print version number (similar to **bpftool version**). 117 118 -j, --json 119 Generate JSON output. For commands that cannot produce JSON, this 120 option has no effect. 121 122 -p, --pretty 123 Generate human-readable JSON output. Implies **-j**. 124 125 -f, --bpffs 126 Show file names of pinned maps. 127 128EXAMPLES 129======== 130**# bpftool map show** 131:: 132 133 10: hash name some_map flags 0x0 134 key 4B value 8B max_entries 2048 memlock 167936B 135 136The following three commands are equivalent: 137 138| 139| **# bpftool map update id 10 key hex 20 c4 b7 00 value hex 0f ff ff ab 01 02 03 4c** 140| **# bpftool map update id 10 key 0x20 0xc4 0xb7 0x00 value 0x0f 0xff 0xff 0xab 0x01 0x02 0x03 0x4c** 141| **# bpftool map update id 10 key 32 196 183 0 value 15 255 255 171 1 2 3 76** 142 143**# bpftool map lookup id 10 key 0 1 2 3** 144 145:: 146 147 key: 00 01 02 03 value: 00 01 02 03 04 05 06 07 148 149 150**# bpftool map dump id 10** 151:: 152 153 key: 00 01 02 03 value: 00 01 02 03 04 05 06 07 154 key: 0d 00 07 00 value: 02 00 00 00 01 02 03 04 155 Found 2 elements 156 157**# bpftool map getnext id 10 key 0 1 2 3** 158:: 159 160 key: 161 00 01 02 03 162 next key: 163 0d 00 07 00 164 165| 166| **# mount -t bpf none /sys/fs/bpf/** 167| **# bpftool map pin id 10 /sys/fs/bpf/map** 168| **# bpftool map del pinned /sys/fs/bpf/map key 13 00 07 00** 169 170SEE ALSO 171======== 172 **bpftool**\ (8), **bpftool-prog**\ (8), **bpftool-cgroup**\ (8) 173