From b9c9ee1ca79765b944269c4ad6a4bb172fc23851 Mon Sep 17 00:00:00 2001
From: Jason Rhinelander <jason@imaginary.ca>
Date: Fri, 9 Sep 2022 17:17:36 -0300
Subject: [PATCH] Fix read problem in linux

errno is only set if read returns < 0 and won't be set to 0 if read
succeeds, so we were bailing here frequently on successful reads
(whenever errno happened to be non-0).
---
 llarp/vpn/linux.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llarp/vpn/linux.hpp b/llarp/vpn/linux.hpp
index 5fc06d674..9dcf9b761 100644
--- a/llarp/vpn/linux.hpp
+++ b/llarp/vpn/linux.hpp
@@ -110,7 +110,7 @@ namespace llarp::vpn
       std::vector<byte_t> pkt;
       pkt.resize(net::IPPacket::MaxSize);
       const auto sz = read(m_fd, pkt.data(), pkt.capacity());
-      if (errno)
+      if (sz < 0)
       {
         if (errno == EAGAIN or errno == EWOULDBLOCK)
         {