Make port optional in X-Forwarded-For

This parser was being overly restrictive which presented integration
issues with haproxy which doesn't make it easy to pass the port info

net/http/parseforwarded.c

@@ -26,6 +26,8 @@
  *
  *     X-Forwarded-For: 203.0.113.42:31337
  *
+ * The port is optional and will be set to zero if absent.
+ *
  * @param s is input data
  * @param n if -1 implies strlen
  * @param ip receives ip on success if not NULL
@@ -34,26 +36,32 @@
  * @see RFC7239's poorly designed Forwarded header
  */
 int ParseForwarded(const char *s, size_t n, uint32_t *ip, uint16_t *port) {
+  int c, t;
   size_t i;
   uint32_t x;
-  int c, j, t;
   if (n == -1) n = s ? strlen(s) : 0;
-  for (t = x = j = i = 0; i < n;) {
+  if (n) {
-    c = s[i++] & 255;
+    t = x = i = 0;
-    if (isdigit(c)) {
+    do {
-      t *= 10;
+      c = s[i++] & 255;
-      t += c - '0';
+      if (isdigit(c)) {
-      if (t > 255) return -1;
+        t *= 10;
-    } else if (c == '.') {
+        t += c - '0';
-      x <<= 8;
+        if (t > 255) return -1;
-      x |= t;
+      } else if (c == '.') {
-      t = 0;
+        x <<= 8;
-      ++j;
+        x |= t;
-    } else if (c == ':') {
+        t = 0;
-      x <<= 8;
+      } else if (c == ':') {
-      x |= t;
+        break;
-      t = 0;
+      } else {
-      if (j != 3) return -1;
+        return -1;
+      }
+    } while (i < n);
+    x <<= 8;
+    x |= t;
+    t = 0;
+    if (c == ':') {
       while (i < n) {
         c = s[i++] & 255;
         if (isdigit(c)) {
@@ -64,13 +72,11 @@ int ParseForwarded(const char *s, size_t n, uint32_t *ip, uint16_t *port) {
           return -1;
         }
       }
-      if (!x || !t) return -1;
-      if (ip) *ip = x;
-      if (port) *port = t;
-      return 0;
-    } else {
-      return -1;
     }
+    if (ip) *ip = x;
+    if (port) *port = t;
+    return 0;
+  } else {
+    return -1;
   }
-  return -1;
 }

test/net/http/isacceptablehost_test.c

@@ -89,43 +89,12 @@ TEST(ParseIp, test) {
   EXPECT_EQ(-1, ParseIp("hello..example", -1));
 }
 
-TEST(ParseForwarded, test) {
-  uint32_t ip = 7;
-  uint16_t port = 7;
-  EXPECT_EQ(-1, ParseForwarded("", -1, &ip, &port));
-  EXPECT_EQ(-1, ParseForwarded("0.0.0.0", -1, &ip, &port));
-  EXPECT_EQ(-1, ParseForwarded("8.8.8.8", -1, &ip, &port));
-  EXPECT_EQ(-1, ParseForwarded("[::1]:123", -1, &ip, &port));
-  EXPECT_EQ(7, ip);
-  EXPECT_EQ(7, port);
-  EXPECT_EQ(0, ParseForwarded("0.0.0.1:123", -1, &ip, &port));
-  EXPECT_EQ(0x00000001, ip);
-  EXPECT_EQ(123, port);
-  EXPECT_EQ(0, ParseForwarded("1.2.3.4:123", -1, &ip, &port));
-  EXPECT_EQ(0x01020304, ip);
-  EXPECT_EQ(123, port);
-  EXPECT_EQ(0, ParseForwarded("128.2.3.4:123", -1, &ip, &port));
-  EXPECT_EQ(0x80020304, ip);
-  EXPECT_EQ(123, port);
-  EXPECT_EQ(0, ParseForwarded("255.255.255.255:123", -1, &ip, &port));
-  EXPECT_EQ(0xFFFFFFFF, ip);
-  EXPECT_EQ(123, port);
-  EXPECT_EQ(0, ParseForwarded("203.0.113.0:123", -1, &ip, &port));
-  EXPECT_EQ(0xcb007100, ip);
-  EXPECT_EQ(123, port);
-  EXPECT_EQ(0, ParseForwarded("203.0.113.42:31337", -1, &ip, &port));
-  EXPECT_EQ(-1, ParseForwarded("...:123", -1, &ip, &port));
-  EXPECT_EQ(-1, ParseForwarded("203.0.113.0:123123123", -1, &ip, &port));
-}
-
 BENCH(IsAcceptableHost, bench) {
   uint32_t ip;
   uint16_t port;
   EZBENCH2("IsAcceptableHost 127.0.0.1", donothing,
            IsAcceptableHost("127.0.0.1", 9));
   EZBENCH2("IsAcceptablePort 80", donothing, IsAcceptablePort("80", 2));
-  EZBENCH2("ParseForwarded 80", donothing,
-           ParseForwarded("203.0.113.42:31337", 20, &ip, &port));
   EZBENCH2("IsAcceptableHost foo.example", donothing,
            IsAcceptableHost("foo.example:31337", 17));
 }

test/net/http/parseforwarded_test.c

@@ -0,0 +1,60 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/testlib/ezbench.h"
+#include "libc/testlib/testlib.h"
+#include "net/http/http.h"
+
+TEST(ParseForwarded, test) {
+  uint32_t ip = 7;
+  uint16_t port = 7;
+  EXPECT_EQ(-1, ParseForwarded("", -1, &ip, &port));
+  EXPECT_EQ(-1, ParseForwarded("[::1]:123", -1, &ip, &port));
+  EXPECT_EQ(-1, ParseForwarded("203.0.113.0:123123123", -1, &ip, &port));
+  EXPECT_EQ(7, ip);
+  EXPECT_EQ(7, port);
+  EXPECT_EQ(0, ParseForwarded("0.0.0.0", -1, &ip, &port));
+  EXPECT_EQ(0x00000000, ip);
+  EXPECT_EQ(0, port);
+  EXPECT_EQ(0, ParseForwarded("8.8.8.8", -1, &ip, &port));
+  EXPECT_EQ(0x08080808, ip);
+  EXPECT_EQ(0, port);
+  EXPECT_EQ(0, ParseForwarded("0.0.0.1:123", -1, &ip, &port));
+  EXPECT_EQ(0x00000001, ip);
+  EXPECT_EQ(123, port);
+  EXPECT_EQ(0, ParseForwarded("1.2.3.4:123", -1, &ip, &port));
+  EXPECT_EQ(0x01020304, ip);
+  EXPECT_EQ(123, port);
+  EXPECT_EQ(0, ParseForwarded("128.2.3.4:123", -1, &ip, &port));
+  EXPECT_EQ(0x80020304, ip);
+  EXPECT_EQ(123, port);
+  EXPECT_EQ(0, ParseForwarded("255.255.255.255:123", -1, &ip, &port));
+  EXPECT_EQ(0xFFFFFFFF, ip);
+  EXPECT_EQ(123, port);
+  EXPECT_EQ(0, ParseForwarded("203.0.113.0:123", -1, &ip, &port));
+  EXPECT_EQ(0xcb007100, ip);
+  EXPECT_EQ(123, port);
+  EXPECT_EQ(0, ParseForwarded("203.0.113.42:31337", -1, &ip, &port));
+}
+
+BENCH(ParseForwarded, bench) {
+  uint32_t ip;
+  uint16_t port;
+  EZBENCH2("ParseForwarded 80", donothing,
+           ParseForwarded("203.0.113.42:31337", 20, &ip, &port));
+}