1 files changed, 79 insertions, 0 deletions
diff --git a/cmds/interrupter/interrupter.h b/cmds/interrupter/interrupter.h
new file mode 100644
index 0000000..9ad0277
--- /dev/null
+++ b/cmds/interrupter/interrupter.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2012, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define CONCATENATE(arg1, arg2)   CONCATENATE1(arg1, arg2)
+#define CONCATENATE1(arg1, arg2)  CONCATENATE2(arg1, arg2)
+#define CONCATENATE2(arg1, arg2)  arg1##arg2
+
+#define INTERRUPTER(sym) \
+    if (real_##sym == NULL) \
+        __init_##sym(); \
+    if (maybe_interrupt()) { \
+        errno = EINTR; \
+        return -1; \
+    }
+
+#define CALL_FUNCTION_1(sym, ret, type1) \
+ret (*real_##sym)(type1) = NULL; \
+ret sym(type1 arg1) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1); \
+}
+
+#define CALL_FUNCTION_2(sym, ret, type1, type2) \
+ret (*real_##sym)(type1, type2) = NULL; \
+ret sym(type1 arg1, type2 arg2) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1, arg2); \
+}
+
+#define CALL_FUNCTION_3(sym, ret, type1, type2, type3) \
+ret (*real_##sym)(type1, type2, type3) = NULL; \
+ret sym(type1 arg1, type2 arg2, type3 arg3) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1, arg2, arg3); \
+}
+
+#define CALL_FUNCTION_4(sym, ret, type1, type2, type3, type4) \
+ret (*real_##sym)(type1, type2, type3, type4) = NULL; \
+ret sym(type1 arg1, type2 arg2, type3 arg3, type4 arg4) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1, arg2, arg3, arg4); \
+}
+
+#define CALL_FUNCTION_5(sym, ret, type1, type2, type3, type4, type5) \
+ret (*real_##sym)(type1, type2, type3, type4, type5) = NULL; \
+ret sym(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5) { \
+    INTERRUPTER(sym) \
+    return real_##sym(arg1, arg2, arg3, arg4, arg5); \
+}
+
+#define DEFINE_INTERCEPT_N(N, sym, ret, ...) \
+static void __init_##sym(void); \
+CONCATENATE(CALL_FUNCTION_, N)(sym, ret, __VA_ARGS__) \
+static void __init_##sym(void) { \
+    real_##sym = dlsym(RTLD_NEXT, #sym); \
+    if (real_##sym == NULL) { \
+        fprintf(stderr, "Error hooking " #sym ": %s\n", dlerror()); \
+    } \
+}
+
+#define INTERCEPT_NARG(...) INTERCEPT_NARG_N(__VA_ARGS__, INTERCEPT_RSEQ_N())
+#define INTERCEPT_NARG_N(...) INTERCEPT_ARG_N(__VA_ARGS__)
+#define INTERCEPT_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, N, ...) N
+#define INTERCEPT_RSEQ_N() 8, 7, 6, 5, 4, 3, 2, 1, 0
+
+#define DEFINE_INTERCEPT(sym, ret, ...) DEFINE_INTERCEPT_N(INTERCEPT_NARG(__VA_ARGS__), sym, ret, __VA_ARGS__)