tools: support ancient NDKs

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/tools/CMakeLists.txt

@@ -8,12 +8,12 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}")
 # Work around https://github.com/android-ndk/ndk/issues/602
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=gold")
 
-add_executable(libwg-quick.so wireguard/src/tools/wg-quick/android.c)
-target_compile_options(libwg-quick.so PUBLIC -O3 -std=gnu11 -Wall -pedantic -Wno-missing-field-initializers -DWG_PACKAGE_NAME=\"${ANDROID_PACKAGE_NAME}\")
+add_executable(libwg-quick.so wireguard/src/tools/wg-quick/android.c ndk-compat/compat.c)
+target_compile_options(libwg-quick.so PUBLIC -O3 -std=gnu11 -Wall -pedantic -Wno-missing-field-initializers -include ${CMAKE_CURRENT_SOURCE_DIR}/ndk-compat/compat.h -DWG_PACKAGE_NAME=\"${ANDROID_PACKAGE_NAME}\")
 
-file(GLOB WG_SOURCES wireguard/src/tools/*.c libmnl/src/*.c)
+file(GLOB WG_SOURCES wireguard/src/tools/*.c libmnl/src/*.c ndk-compat/compat.c)
 add_executable(libwg.so ${WG_SOURCES})
-target_compile_options(libwg.so PUBLIC -idirafter "${CMAKE_CURRENT_SOURCE_DIR}/libmnl/include/" -I "${CMAKE_CURRENT_SOURCE_DIR}/wireguard/src/tools/" -O3 -std=gnu11 -D_GNU_SOURCE -DHAVE_VISIBILITY_HIDDEN -DRUNSTATEDIR=\"/data/data/${ANDROID_PACKAGE_NAME}/cache\" -Wno-pointer-arith -Wno-unused-parameter)
+target_compile_options(libwg.so PUBLIC -idirafter "${CMAKE_CURRENT_SOURCE_DIR}/libmnl/include/" -I "${CMAKE_CURRENT_SOURCE_DIR}/wireguard/src/tools/" -O3 -std=gnu11 -D_GNU_SOURCE -include ${CMAKE_CURRENT_SOURCE_DIR}/ndk-compat/compat.h -DHAVE_VISIBILITY_HIDDEN -DRUNSTATEDIR=\"/data/data/${ANDROID_PACKAGE_NAME}/cache\" -Wno-pointer-arith -Wno-unused-parameter)
 
 add_custom_target(libwg-go.so WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/libwg-go" COMMENT "Building wireguard-go" VERBATIM COMMAND make
     ANDROID_ARCH_NAME=${ANDROID_ARCH_NAME}

app/tools/ndk-compat/compat.c

@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: BSD
+ *
+ * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ */
+
+#define FILE_IS_EMPTY
+
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 18
+#undef FILE_IS_EMPTY
+#include <stdio.h>
+#include <stdlib.h>
+
+ssize_t getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
+{
+	char *ptr, *eptr;
+
+	if (*buf == NULL || *bufsiz == 0) {
+		*bufsiz = BUFSIZ;
+		if ((*buf = malloc(*bufsiz)) == NULL)
+			return -1;
+	}
+
+	for (ptr = *buf, eptr = *buf + *bufsiz;;) {
+		int c = fgetc(fp);
+		if (c == -1) {
+			if (feof(fp)) {
+				ssize_t diff = (ssize_t)(ptr - *buf);
+				if (diff != 0) {
+					*ptr = '\0';
+					return diff;
+				}
+			}
+			return -1;
+		}
+		*ptr++ = c;
+		if (c == delimiter) {
+			*ptr = '\0';
+			return ptr - *buf;
+		}
+		if (ptr + 2 >= eptr) {
+			char *nbuf;
+			size_t nbufsiz = *bufsiz * 2;
+			ssize_t d = ptr - *buf;
+			if ((nbuf = realloc(*buf, nbufsiz)) == NULL)
+				return -1;
+			*buf = nbuf;
+			*bufsiz = nbufsiz;
+			eptr = nbuf + nbufsiz;
+			ptr = nbuf + d;
+		}
+	}
+}
+
+ssize_t getline(char **buf, size_t *bufsiz, FILE *fp)
+{
+	return getdelim(buf, bufsiz, '\n', fp);
+}
+#endif
+
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 24
+#undef FILE_IS_EMPTY
+#include <string.h>
+
+char *strchrnul(const char *s, int c)
+{
+        char *x = strchr(s, c);
+        if (!x)
+                return (char *)s + strlen(s);
+        return x;
+}
+#endif
+
+#ifdef FILE_IS_EMPTY
+#undef FILE_IS_EMPTY
+static char ____x __attribute__((unused));
+#endif

app/tools/ndk-compat/compat.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: BSD
+ *
+ * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ */
+
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 18
+#include <stdio.h>
+ssize_t getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp);
+ssize_t getline(char **buf, size_t *bufsiz, FILE *fp);
+#endif
+
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 24
+char *strchrnul(const char *s, int c);
+#endif
+

app/tools/wireguard

@@ -1 +1 @@
-Subproject commit be3e2a9134e1833c313e700132018de12fe2839d
+Subproject commit f52f9d045f5a6dceea2bbe70e22405ea07c62960