bpftool: Match maps by name

This patch implements lookup by name for maps and changes the behavior of
lookups by tag to be consistent with prog subcommands.  Similarly to
program subcommands, the show and dump commands will return all maps with
the given name (or tag), whereas other commands will error out if several
maps have the same name (resp. tag).

When a map has BTF info, it is dumped in JSON with available BTF info.
This patch requires that all matched maps have BTF info before switching
the output format to JSON.

Signed-off-by: Paul Chaignon <paul.chaignon@orange.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/8de1c9f273860b3ea1680502928f4da2336b853e.1576263640.git.paul.chaignon@gmail.com

1 files changed, 122 insertions, 9 deletions

diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 05b5be4a6ef9..21c676a1eeb1 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -59,6 +59,21 @@ _bpftool_get_map_ids_for_type()
         command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )
 }
 
+_bpftool_get_map_names()
+{
+    COMPREPLY+=( $( compgen -W "$( bpftool -jp map  2>&1 | \
+        command sed -n 's/.*"name": \(.*\),$/\1/p' )" -- "$cur" ) )
+}
+
+# Takes map type and adds matching map names to the list of suggestions.
+_bpftool_get_map_names_for_type()
+{
+    local type="$1"
+    COMPREPLY+=( $( compgen -W "$( bpftool -jp map  2>&1 | \
+        command grep -C2 "$type" | \
+        command sed -n 's/.*"name": \(.*\),$/\1/p' )" -- "$cur" ) )
+}
+
 _bpftool_get_prog_ids()
 {
     COMPREPLY+=( $( compgen -W "$( bpftool -jp prog 2>&1 | \
@@ -186,6 +201,52 @@ _bpftool_map_update_get_id()
     esac
 }
 
+_bpftool_map_update_get_name()
+{
+    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
+    for (( idx=7; idx < ${#words[@]}-1; idx++ )); do
+        if [[ ${words[idx]} == "value" ]]; then
+            value=1
+            break
+        fi
+    done
+    if [[ $value -eq 0 ]]; then
+        case "$command" in
+            push)
+                _bpftool_get_map_names_for_type stack
+                ;;
+            enqueue)
+                _bpftool_get_map_names_for_type queue
+                ;;
+            *)
+                _bpftool_get_map_names
+                ;;
+        esac
+        return 0
+    fi
+
+    # Name to complete is for a value. It can be either prog name or map name. This
+    # depends on the type of the map to update.
+    local type=$(_bpftool_map_guess_map_type)
+    case $type in
+        array_of_maps|hash_of_maps)
+            _bpftool_get_map_names
+            return 0
+            ;;
+        prog_array)
+            _bpftool_get_prog_names
+            return 0
+            ;;
+        *)
+            return 0
+            ;;
+    esac
+}
+
 _bpftool()
 {
     local cur prev words objword
@@ -207,10 +268,6 @@ _bpftool()
             _bpftool_get_prog_tags
             return 0
             ;;
-        name)
-            _bpftool_get_prog_names
-            return 0
-            ;;
         dev)
             _sysfs_get_netdevs
             return 0
@@ -261,7 +318,8 @@ _bpftool()
     # Completion depends on object and command in use
     case $object in
         prog)
-            # Complete id, only for subcommands that use prog (but no map) ids
+            # Complete id and name, only for subcommands that use prog (but no
+            # map) ids/names.
             case $command in
                 show|list|dump|pin)
                     case $prev in
@@ -269,12 +327,16 @@ _bpftool()
                             _bpftool_get_prog_ids
                             return 0
                             ;;
+                        name)
+                            _bpftool_get_prog_names
+                            return 0
+                            ;;
                     esac
                     ;;
             esac
 
             local PROG_TYPE='id pinned tag name'
-            local MAP_TYPE='id pinned'
+            local MAP_TYPE='id pinned name'
             case $command in
                 show|list)
                     [[ $prev != "$command" ]] && return 0
@@ -325,6 +387,9 @@ _bpftool()
                                 id)
                                     _bpftool_get_prog_ids
                                     ;;
+                                name)
+                                    _bpftool_get_map_names
+                                    ;;
                                 pinned)
                                     _filedir
                                     ;;
@@ -345,6 +410,9 @@ _bpftool()
                                 id)
                                     _bpftool_get_map_ids
                                     ;;
+                                name)
+                                    _bpftool_get_map_names
+                                    ;;
                                 pinned)
                                     _filedir
                                     ;;
@@ -409,6 +477,10 @@ _bpftool()
                             _bpftool_get_map_ids
                             return 0
                             ;;
+                        name)
+                            _bpftool_get_map_names
+                            return 0
+                            ;;
                         pinned|pinmaps)
                             _filedir
                             return 0
@@ -457,7 +529,7 @@ _bpftool()
             esac
             ;;
         map)
-            local MAP_TYPE='id pinned'
+            local MAP_TYPE='id pinned name'
             case $command in
                 show|list|dump|peek|pop|dequeue|freeze)
                     case $prev in
@@ -483,6 +555,24 @@ _bpftool()
                             esac
                             return 0
                             ;;
+                        name)
+                            case "$command" in
+                                peek)
+                                    _bpftool_get_map_names_for_type stack
+                                    _bpftool_get_map_names_for_type queue
+                                    ;;
+                                pop)
+                                    _bpftool_get_map_names_for_type stack
+                                    ;;
+                                dequeue)
+                                    _bpftool_get_map_names_for_type queue
+                                    ;;
+                                *)
+                                    _bpftool_get_map_names
+                                    ;;
+                            esac
+                            return 0
+                            ;;
                         *)
                             return 0
                             ;;
@@ -530,6 +620,10 @@ _bpftool()
                             _bpftool_get_map_ids
                             return 0
                             ;;
+                        name)
+                            _bpftool_get_map_names
+                            return 0
+                            ;;
                         key)
                             COMPREPLY+=( $( compgen -W 'hex' -- "$cur" ) )
                             ;;
@@ -555,6 +649,10 @@ _bpftool()
                             _bpftool_map_update_get_id $command
                             return 0
                             ;;
+                        name)
+                            _bpftool_map_update_get_name $command
+                            return 0
+                            ;;
                         key)
                             COMPREPLY+=( $( compgen -W 'hex' -- "$cur" ) )
                             ;;
@@ -563,7 +661,7 @@ _bpftool()
                             # map, depending on the type of the map to update.
                             case "$(_bpftool_map_guess_map_type)" in
                                 array_of_maps|hash_of_maps)
-                                    local MAP_TYPE='id pinned'
+                                    local MAP_TYPE='id pinned name'
                                     COMPREPLY+=( $( compgen -W "$MAP_TYPE" \
                                         -- "$cur" ) )
                                     return 0
@@ -631,6 +729,10 @@ _bpftool()
                             _bpftool_get_map_ids_for_type perf_event_array
                             return 0
                             ;;
+                        name)
+                            _bpftool_get_map_names_for_type perf_event_array
+                            return 0
+                            ;;
                         cpu)
                             return 0
                             ;;
@@ -655,7 +757,7 @@ _bpftool()
             ;;
         btf)
             local PROG_TYPE='id pinned tag name'
-            local MAP_TYPE='id pinned'
+            local MAP_TYPE='id pinned name'
             case $command in
                 dump)
                     case $prev in
@@ -686,6 +788,17 @@ _bpftool()
                             esac
                             return 0
                             ;;
+                        name)
+                            case $pprev in
+                                prog)
+                                    _bpftool_get_prog_names
+                                    ;;
+                                map)
+                                    _bpftool_get_map_names
+                                    ;;
+                            esac
+                            return 0
+                            ;;
                         format)
                             COMPREPLY=( $( compgen -W "c raw" -- "$cur" ) )
                             ;;