From 896db8843f84b882085e7d1bfd05c24194893d48 Mon Sep 17 00:00:00 2001
From: Justine Tunney <jtunney@gmail.com>
Date: Sat, 9 Jul 2022 04:24:51 -0700
Subject: [PATCH] Loosen restriction on valid hostnames

This changes fixes an issue with GitPod integration, where large numbers
in a hostname were incorrectly causing redbean to refuse a request.
---
 net/http/isacceptablehost.c           | 17 +++++++++++------
 test/net/http/isacceptablehost_test.c |  5 ++++-
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/net/http/isacceptablehost.c b/net/http/isacceptablehost.c
index f2506a4a9..b422a29a7 100644
--- a/net/http/isacceptablehost.c
+++ b/net/http/isacceptablehost.c
@@ -55,17 +55,18 @@ bool IsAcceptableHost(const char *s, size_t n) {
   int c, b, j;
   if (n == -1) n = s ? strlen(s) : 0;
   if (!n) return true;
-  if (n > DNS_NAME_MAX) return false;
+  if (n > DNS_NAME_MAX) {
+    return false;
+  }
   for (b = j = i = 0; i < n; ++i) {
     c = s[i] & 255;
     if (isdigit(c)) {
       b *= 10;
       b += c - '0';
-      if (b > 255) {
+    } else if (c == '.') {
+      if (!i || s[i - 1] == '.') {
         return false;
       }
-    } else if (c == '.') {
-      if (!i || s[i - 1] == '.') return false;
       b = 0;
       ++j;
     } else {
@@ -81,7 +82,11 @@ bool IsAcceptableHost(const char *s, size_t n) {
       }
     }
   }
-  if (j != 3) return false;
-  if (i && s[i - 1] == '.') return false;
+  if (j != 3) {
+    return false;
+  }
+  if (i && s[i - 1] == '.') {
+    return false;
+  }
   return true;
 }
diff --git a/test/net/http/isacceptablehost_test.c b/test/net/http/isacceptablehost_test.c
index fbe3df305..66b35f415 100644
--- a/test/net/http/isacceptablehost_test.c
+++ b/test/net/http/isacceptablehost_test.c
@@ -29,7 +29,6 @@ TEST(IsAcceptableHost, test) {
   EXPECT_TRUE(IsAcceptableHost("1.2.3.4.5.arpa", -1));
   EXPECT_TRUE(IsAcceptableHost("255.255.255.255", -1));
   EXPECT_FALSE(IsAcceptableHost("255.255.255", -1));
-  EXPECT_FALSE(IsAcceptableHost("256.255.255.255", -1));
   EXPECT_TRUE(IsAcceptableHost("hello.example", -1));
   EXPECT_FALSE(IsAcceptableHost("hello..example", -1));
   EXPECT_TRUE(IsAcceptableHost("hello", -1));
@@ -46,6 +45,10 @@ TEST(IsAcceptableHost, test) {
   EXPECT_TRUE(IsAcceptableHost("there-.example", -1));
   EXPECT_FALSE(IsAcceptableHost("ther#e.example", -1));
   EXPECT_TRUE(IsAcceptableHost("localhost", -1));
+  EXPECT_TRUE(IsAcceptableHost("8080-gitpodio-empty-abs4xad1abc", -1));
+  EXPECT_TRUE(IsAcceptableHost("ws-eu53", -1));
+  EXPECT_TRUE(IsAcceptableHost("gitpod", -1));
+  EXPECT_TRUE(IsAcceptableHost("io", -1));
 }
 
 TEST(IsAcceptablePort, test) {