From ccdb5db67558205dd8d451e1878774cc93835cd1 Mon Sep 17 00:00:00 2001
From: MCApollo <34170230+MCApollo@users.noreply.github.com>
Date: Mon, 3 Aug 2020 18:57:43 -0900
Subject: [PATCH] tcp-tunnel: botch Linux support

---
 tcp-tunnel/Makefile   |  1 +
 tcp-tunnel/src/main.c | 21 ++++++++++++++++-----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/tcp-tunnel/Makefile b/tcp-tunnel/Makefile
index a2ef74d..989ba71 100644
--- a/tcp-tunnel/Makefile
+++ b/tcp-tunnel/Makefile
@@ -10,6 +10,7 @@ src := $(wildcard src/*.c) $(wildcard src/**/*.c)
 
 CC = clang
 FLAGS = -DOUT_OF_TREE_BUILD -I$(QEMU_DIR)/include -fno-stack-check -fno-stack-protector -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk
+# FLAGS += -DLINUX
 TARGET = tunnel
 
 bin/$(TARGET): $(src)
diff --git a/tcp-tunnel/src/main.c b/tcp-tunnel/src/main.c
index 14aef64..6540662 100644
--- a/tcp-tunnel/src/main.c
+++ b/tcp-tunnel/src/main.c
@@ -14,6 +14,17 @@
 #define DIR_IN 1
 #define DIR_OUT 2
 
+#ifdef LINUX
+/* FIXME: There's no way to detect this, good luck.
+	Apple changed EAGAIN to a different number, causing errors during runtime.
+*/
+# define EEAGAIN 11
+# define EEWOULDBLOCK EEAGAIN
+#else /* __APPLE__ */
+# define EEAGAIN EAGAIN
+# define EEWOULDBLOCK EWOULDBLOCK
+#endif
+
 typedef struct {
     int fd;
     int *error;
@@ -237,8 +248,8 @@ static int send_receive(socket_t *in, socket_t *out)
             out->close(out->fd);
             return 0;
         } else {
-            if ((*(in->error) != EAGAIN) && \
-                (*(in->error) != EWOULDBLOCK))
+            if ((*(in->error) != EEAGAIN) && \
+                (*(in->error) != EEWOULDBLOCK))
             {
                 // Remote socket error!
                 out->close(out->fd);
@@ -260,7 +271,7 @@ static int send_receive(socket_t *in, socket_t *out)
             return 0;
         } else {
             if ((*(out->error) != EAGAIN) && \
-                (*(out->error) != EWOULDBLOCK))
+                (*(out->error) != EWOULDBLOCK)) // Don't use EEAGAIN on `out`.
             {
                 // Target socket error!
                 out->close(out->fd);
@@ -371,8 +382,8 @@ static int tunnel(socket_t *s_listen, socket_t *in, socket_t *out,
                                   &remotelen);
 
         if (in->fd < 0) {
-            if ((*(in->error) != EAGAIN ) && \
-                (*(in->error) != EWOULDBLOCK))
+            if ((*(in->error) != EEAGAIN ) && \
+                (*(in->error) != EEWOULDBLOCK))
             {
                 fprintf(stderr, "accept failed: %d\n", *(in->error));
                 s_listen->close(s_listen->fd);