Add fuzzing infrastructure

Though text formats aren't exactly fuzzer's strong suit, fuzzers can
catch many surface-level bugs.

The fuzz/ directory contains target programs, testcases and dictionaries
to drive the afl fuzzer.

This commit adds a fuzzer for the XKB keymap text format and the Compose
text format. On my slow machine, using a single core, a full cycle of
the XKB fuzzer takes 5 hours. For Compose, it takes a few minutes.

Fuzzing for the other file formats (rules files mostly) will be added
later.

To do some fuzzing, run `./fuzz/fuzz.sh`.

Signed-off-by: Ran Benita <ran234@gmail.com>

8 files changed, 295 insertions, 0 deletions

diff --git a/fuzz/.gitignore b/fuzz/.gitignore
new file mode 100644
index 0000000..413910a
--- /dev/null
+++ b/fuzz/.gitignore
@@ -0,0 +1 @@
+findings/
diff --git a/fuzz/compose/dict b/fuzz/compose/dict
new file mode 100644
index 0000000..38dfe3a
--- /dev/null
+++ b/fuzz/compose/dict
@@ -0,0 +1,8 @@
+"Ctrl"
+"Lock"
+"Caps"
+"Shift"
+"Alt"
+"Meta"
+"None"
+"acute"
diff --git a/fuzz/compose/target.c b/fuzz/compose/target.c
new file mode 100644
index 0000000..69b434e
--- /dev/null
+++ b/fuzz/compose/target.c
@@ -0,0 +1,45 @@
+/*
+ * A target program for fuzzing the Compose text format.
+ *
+ * Currently, just parses an input file, and hopefully doesn't crash or hang.
+ */
+
+#include <assert.h>
+
+#include "xkbcommon/xkbcommon.h"
+#include "xkbcommon/xkbcommon-compose.h"
+
+int
+main(int argc, char *argv[])
+{
+    struct xkb_context *ctx;
+    FILE *file;
+    struct xkb_compose_table *table;
+
+    if (argc != 2) {
+        fprintf(stderr, "usage: %s <file>\n", argv[0]);
+        return 1;
+    }
+
+    ctx = xkb_context_new(XKB_CONTEXT_NO_DEFAULT_INCLUDES | XKB_CONTEXT_NO_ENVIRONMENT_NAMES);
+    assert(ctx);
+
+#ifdef __AFL_HAVE_MANUAL_CONTROL
+  __AFL_INIT();
+
+    while (__AFL_LOOP(1000))
+#endif
+    {
+        file = fopen(argv[1], "r");
+        assert(file);
+        table = xkb_compose_table_new_from_file(ctx, file,
+                                                "en_US.UTF-8",
+                                                XKB_COMPOSE_FORMAT_TEXT_V1,
+                                                XKB_COMPOSE_COMPILE_NO_FLAGS);
+        xkb_compose_table_unref(table);
+        fclose(file);
+    }
+
+    puts(table ? "OK" : "FAIL");
+    xkb_context_unref(ctx);
+}
diff --git a/fuzz/compose/testcases/Compose b/fuzz/compose/testcases/Compose
new file mode 100644
index 0000000..a62727d
--- /dev/null
+++ b/fuzz/compose/testcases/Compose
@@ -0,0 +1,2 @@
+<dead_tilde> <space> : "~" asciitilde # X
+Meta <Multi_key> !Alt ~Shift <apostrophe> <apostrophe> : "\"\'\x43\123abc" acute # Y
diff --git a/fuzz/fuzz.sh b/fuzz/fuzz.sh
new file mode 100755
index 0000000..65aab9c
--- /dev/null
+++ b/fuzz/fuzz.sh
@@ -0,0 +1,17 @@
+#!/bin/sh
+set -e
+
+case "$1" in
+    keymap|compose)
+        ;;
+    *)
+        echo "usage: $0 keymap|compose" 1>&2
+        exit 1
+        ;;
+esac
+
+export CC=afl-clang-fast
+export AFL_HARDEN=1
+test -d fuzz/build || meson setup -Db_lto=true fuzz/build
+ninja -C fuzz/build
+afl-fuzz -i fuzz/$1/testcases -x fuzz/$1/dict -o fuzz/$1/findings -t 200 -m 10 -- ./fuzz/build/fuzz-$1 @@
diff --git a/fuzz/keymap/dict b/fuzz/keymap/dict
new file mode 100644
index 0000000..2a7ac69
--- /dev/null
+++ b/fuzz/keymap/dict
@@ -0,0 +1,120 @@
+"Control"
+"Group1"
+"Group5"
+"Lock"
+"Mod1"
+"Mod9"
+"Shift"
+"U1"
+"0x1"
+"Up"
+"accel"
+"action"
+"actions"
+"affect"
+"alias"
+"all"
+"allowexplicit"
+"allownone"
+"alphanumeric_keys"
+"alternate"
+"alternate_group"
+"any"
+"augment"
+"both"
+"button"
+"clearLocks"
+"clearmods"
+"controls"
+"count"
+"ctrls"
+"data"
+"default"
+"dev"
+"device"
+"dfltbtn"
+"driveskbd"
+"false"
+"foo"
+"function_keys"
+"genKeyEvent"
+"group"
+"groupname"
+"groups"
+"groupsclamp"
+"groupsredirect"
+"groupswrap"
+"hidden"
+"include"
+"increment"
+"index"
+"indicator"
+"indicatordriveskbd"
+"interpret"
+"kc"
+"key"
+"keycode"
+"keypad_keys"
+"keys"
+"latchToLock"
+"leddriveskbd"
+"levelname"
+"lock"
+"locking"
+"logo"
+"map"
+"mod_map"
+"modifier_keys"
+"modifier_map"
+"modifiers"
+"modmap"
+"modmapmods"
+"mods"
+"name"
+"neither"
+"no"
+"none"
+"nosymbol"
+"off"
+"on"
+"outline"
+"overlay"
+"override"
+"partial"
+"preserve"
+"radiogroup"
+"repeat"
+"replace"
+"report"
+"row"
+"same"
+"sameServer"
+"screen"
+"section"
+"shape"
+"solid"
+"symbols"
+"text"
+"true"
+"type"
+"unlock"
+"usemodmap"
+"value"
+"virtual"
+"virtual_modifiers"
+"virtualmod"
+"vmods"
+"voidsymbol"
+"whichgroupstate"
+"whichmodstate"
+"x"
+"xkb_compat"
+"xkb_geometry"
+"xkb_keycodes"
+"xkb_keymap"
+"xkb_layout"
+"xkb_semantics"
+"xkb_symbols"
+"xkb_types"
+"y"
+"yes"
diff --git a/fuzz/keymap/target.c b/fuzz/keymap/target.c
new file mode 100644
index 0000000..3c5e5f7
--- /dev/null
+++ b/fuzz/keymap/target.c
@@ -0,0 +1,43 @@
+/*
+ * A target program for fuzzing the XKB keymap text format.
+ *
+ * Currently, just parses an input file, and hopefully doesn't crash or hang.
+ */
+
+#include <assert.h>
+
+#include "xkbcommon/xkbcommon.h"
+
+int
+main(int argc, char *argv[])
+{
+    struct xkb_context *ctx;
+    FILE *file;
+    struct xkb_keymap *keymap;
+
+    if (argc != 2) {
+        fprintf(stderr, "usage: %s <file>\n", argv[0]);
+        return 1;
+    }
+
+    ctx = xkb_context_new(XKB_CONTEXT_NO_DEFAULT_INCLUDES | XKB_CONTEXT_NO_ENVIRONMENT_NAMES);
+    assert(ctx);
+
+#ifdef __AFL_HAVE_MANUAL_CONTROL
+  __AFL_INIT();
+
+    while (__AFL_LOOP(1000))
+#endif
+    {
+        file = fopen(argv[1], "r");
+        assert(file);
+        keymap = xkb_keymap_new_from_file(ctx, file,
+                                          XKB_KEYMAP_FORMAT_TEXT_V1,
+                                          XKB_KEYMAP_COMPILE_NO_FLAGS);
+        xkb_keymap_unref(keymap);
+        fclose(file);
+    }
+
+    puts(keymap ? "OK" : "FAIL");
+    xkb_context_unref(ctx);
+}
diff --git a/fuzz/keymap/testcases/input.xkb b/fuzz/keymap/testcases/input.xkb
new file mode 100644
index 0000000..64ea6a3
--- /dev/null
+++ b/fuzz/keymap/testcases/input.xkb
@@ -0,0 +1,59 @@
+xkb_keymap{
+xkb_keycodes"0"{
+minimum=0;
+maximum=500;
+<a>=0;
+indicator 1="X";
+alias<X>=<Y>;
+};
+xkb_types"X"{
+virtual_modifiers NumLock;
+type"X"{
+modifiers=Shift;
+map[Shift]=Level2;
+level_name[Level1]="X";
+preserve[Shift]=Shift;
+};
+};
+partial xkb_compat{
+virtual_modifiers Alt;
+interpret.useModMapMods=AnyLevel;
+interpret.repeat=False;
+interpret.locking=False;
+interpret ISO_Level2_Latch+Exactly(Shift){
+repeat=True;
+virtualModifier=NumLock;
+useModMapMods=level1;
+action=LatchMods(modifiers=Shift,clearLocks,latchToLock);
+action=MovePtr(x=+0,y=-0);
+action=SwitchScreen(screen=00,!same);
+action=Private(type=0x80,data[0]=0x00);
+};
+indicator"X"{whichModState=locked;modifiers=Lock;};
+};
+xkb_symbols{
+name[group1]="X";
+key<Y>{type[group2]="X",symbols[Group1]=[0,exclam],symbols[Group2]=[0xff,U00],symbols[Group3]=[z]};
+modifier_map Control{<a>};
+};
+default xkb_geometry"X"{
+description="X";
+width=470;
+shape.cornerRadius=1;
+shape"NORM"{cornerRadius=0,{[0.0,0]},{[0,0],[0,0.0]}};
+solid"X"{shape="X";top=00;left=00;color="X";};
+indicator.onColor="X";
+indicator.top=00.0;
+indicator.shape="X";
+indicator"X"{left=0;};
+text.top=00;
+text.color="X";
+text"X"{left=0;text="X";};
+section.left=00;
+row.left=0;
+key.shape="X";
+key.gap=1;
+section"X"{top=22;row{top=1;keys{{<X>,color="X"},{<X>,00.0},<X>,<X>,<X>};};};
+alias<AC00>=<CAPS>;
+};
+};