bpftool: add bash completion for peek/push/enqueue/pop/dequeue

bpftool map peek id <TAB>      - suggests only queue and stack map ids
bpftool map pop id <TAB>       - suggests only stack map ids
bpftool map dequeue id <TAB>   - suggests only queue map ids

bpftool map push id <TAB>      - suggests only stack map ids
bpftool map enqueue id <TAB>   - suggests only queue map ids

bpftool map push id 1 <TAB>    - suggests 'value', not 'key'
bpftool map enqueue id 2 <TAB> - suggests 'value', not 'key'

bpftool map update id <stack/queue type> - suggests 'value', not 'key'
bpftool map lookup id <stack/queue type> - suggests nothing
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/bpf/bpftool/bash-completion/bpftool

@@ -50,14 +50,15 @@ _bpftool_get_map_ids()
         command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )
 }
 
-_bpftool_get_perf_map_ids()
+# Takes map type and adds matching map ids to the list of suggestions.
+_bpftool_get_map_ids_for_type()
 {
+    local type="$1"
     COMPREPLY+=( $( compgen -W "$( bpftool -jp map  2>&1 | \
-        command grep -C2 perf_event_array | \
+        command grep -C2 "$type" | \
         command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )
 }
 
-
 _bpftool_get_prog_ids()
 {
     COMPREPLY+=( $( compgen -W "$( bpftool -jp prog 2>&1 | \
@@ -99,15 +100,25 @@ _sysfs_get_netdevs()
         "$cur" ) )
 }
 
-# For bpftool map update: retrieve type of the map to update.
-_bpftool_map_update_map_type()
+# Retrieve type of the map that we are operating on.
+_bpftool_map_guess_map_type()
 {
     local keyword ref
     for (( idx=3; idx < ${#words[@]}-1; idx++ )); do
-        if [[ ${words[$((idx-2))]} == "update" ]]; then
+        case "${words[$((idx-2))]}" in
+            lookup|update)
                 keyword=${words[$((idx-1))]}
                 ref=${words[$((idx))]}
-        fi
+                ;;
+            push)
+                printf "stack"
+                return 0
+                ;;
+            enqueue)
+                printf "queue"
+                return 0
+                ;;
+        esac
     done
     [[ -z $ref ]] && return 0
 
@@ -119,6 +130,8 @@ _bpftool_map_update_map_type()
 
 _bpftool_map_update_get_id()
 {
+    local command="$1"
+
     # Is it the map to update, or a map to insert into the map to update?
     # Search for "value" keyword.
     local idx value
@@ -128,11 +141,24 @@ _bpftool_map_update_get_id()
             break
         fi
     done
-    [[ $value -eq 0 ]] && _bpftool_get_map_ids && return 0
+    if [[ $value -eq 0 ]]; then
+        case "$command" in
+            push)
+                _bpftool_get_map_ids_for_type stack
+                ;;
+            enqueue)
+                _bpftool_get_map_ids_for_type queue
+                ;;
+            *)
+                _bpftool_get_map_ids
+                ;;
+        esac
+        return 0
+    fi
 
     # Id to complete is for a value. It can be either prog id or map id. This
     # depends on the type of the map to update.
-    local type=$(_bpftool_map_update_map_type)
+    local type=$(_bpftool_map_guess_map_type)
     case $type in
         array_of_maps|hash_of_maps)
             _bpftool_get_map_ids
@@ -382,14 +408,28 @@ _bpftool()
         map)
             local MAP_TYPE='id pinned'
             case $command in
-                show|list|dump)
+                show|list|dump|peek|pop|dequeue)
                     case $prev in
                         $command)
                             COMPREPLY=( $( compgen -W "$MAP_TYPE" -- "$cur" ) )
                             return 0
                             ;;
                         id)
+                            case "$command" in
+                                peek)
+                                    _bpftool_get_map_ids_for_type stack
+                                    _bpftool_get_map_ids_for_type queue
+                                    ;;
+                                pop)
+                                    _bpftool_get_map_ids_for_type stack
+                                    ;;
+                                dequeue)
+                                    _bpftool_get_map_ids_for_type queue
+                                    ;;
+                                *)
                                     _bpftool_get_map_ids
+                                    ;;
+                            esac
                             return 0
                             ;;
                         *)
@@ -447,19 +487,25 @@ _bpftool()
                             COMPREPLY+=( $( compgen -W 'hex' -- "$cur" ) )
                             ;;
                         *)
+                            case $(_bpftool_map_guess_map_type) in
+                                queue|stack)
+                                    return 0
+                                    ;;
+                            esac
+
                             _bpftool_once_attr 'key'
                             return 0
                             ;;
                     esac
                     ;;
-                update)
+                update|push|enqueue)
                     case $prev in
                         $command)
                             COMPREPLY=( $( compgen -W "$MAP_TYPE" -- "$cur" ) )
                             return 0
                             ;;
                         id)
-                            _bpftool_map_update_get_id
+                            _bpftool_map_update_get_id $command
                             return 0
                             ;;
                         key)
@@ -468,7 +514,7 @@ _bpftool()
                         value)
                             # We can have bytes, or references to a prog or a
                             # map, depending on the type of the map to update.
-                            case $(_bpftool_map_update_map_type) in
+                            case "$(_bpftool_map_guess_map_type)" in
                                 array_of_maps|hash_of_maps)
                                     local MAP_TYPE='id pinned'
                                     COMPREPLY+=( $( compgen -W "$MAP_TYPE" \
@@ -490,6 +536,13 @@ _bpftool()
                             return 0
                             ;;
                         *)
+                            case $(_bpftool_map_guess_map_type) in
+                                queue|stack)
+                                    _bpftool_once_attr 'value'
+                                    return 0;
+                                    ;;
+                            esac
+
                             _bpftool_once_attr 'key'
                             local UPDATE_FLAGS='any exist noexist'
                             for (( idx=3; idx < ${#words[@]}-1; idx++ )); do
@@ -508,6 +561,7 @@ _bpftool()
                                     return 0
                                 fi
                             done
+
                             return 0
                             ;;
                     esac
@@ -527,7 +581,7 @@ _bpftool()
                             return 0
                             ;;
                         id)
-                            _bpftool_get_perf_map_ids
+                            _bpftool_get_map_ids_for_type perf_event_array
                             return 0
                             ;;
                         cpu)
@@ -546,7 +600,8 @@ _bpftool()
                 *)
                     [[ $prev == $object ]] && \
                         COMPREPLY=( $( compgen -W 'delete dump getnext help \
-                            lookup pin event_pipe show list update create' -- \
+                            lookup pin event_pipe show list update create \
+                            peek push enqueue pop dequeue' -- \
                             "$cur" ) )
                     ;;
             esac