[PATCH] Ignore unexpected 1xx status messages from the upstream.

[Piotr Sikora]

Ignore unexpected 1xx status messages from the upstream.

RFC2616 10.1 Informational 1xx says:
A client MUST be prepared to accept one or more 1xx status responses
prior to a regular response, even if the client does not expect a 100
(Continue) status message. Unexpected 1xx status responses MAY be
ignored by a user agent.

Signed-off-by: Piotr Sikora <piotr at cloudflare.com>
---
 src/http/ngx_http_parse.c | 71 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 3 deletions(-)

diff --git a/src/http/ngx_http_parse.c b/src/http/ngx_http_parse.c
index a6ee74e..835edda 100644
--- a/src/http/ngx_http_parse.c
+++ b/src/http/ngx_http_parse.c
@@ -1432,7 +1432,11 @@
         sw_status,
         sw_space_after_status,
         sw_status_text,
-        sw_almost_done
+        sw_almost_done,
+        sw_ignore_space_after_status,
+        sw_ignore_start,
+        sw_ignore_text,
+        sw_ignore_almost_done
     } state;

     state = r->state;
@@ -1554,8 +1558,17 @@
             status->code = status->code * 10 + ch - '0';

             if (++status->count == 3) {
-                state = sw_space_after_status;
-                status->start = p - 2;
+                if (status->code == 100
+                    && r->http_major == 1 && r->http_minor == 1)
+                {
+                    state = sw_ignore_space_after_status;
+                    status->code = 0;
+                    status->count = 0;
+
+                } else {
+                    state = sw_space_after_status;
+                    status->start = p - 2;
+                }
             }

             break;
@@ -1600,6 +1613,58 @@
             default:
                 return NGX_ERROR;
             }
+            break;
+
+        /* space or end of line in ignored part */
+        case sw_ignore_space_after_status:
+            switch (ch) {
+            case ' ':
+                state = sw_ignore_text;
+                break;
+            case CR:
+                state = sw_ignore_text;
+                break;
+            case LF:
+                state = sw_ignore_start;
+                break;
+            default:
+                return NGX_ERROR;
+            }
+            break;
+
+        /* new line in ignored part */
+        case sw_ignore_start:
+            switch (ch) {
+            case CR:
+                state = sw_ignore_almost_done;
+                break;
+            case LF:
+                state = sw_start;
+                break;
+            default:
+                state = sw_ignore_text;
+                break;
+            }
+            break;
+
+        /* any text in ignored part until end of line */
+        case sw_ignore_text:
+            switch (ch) {
+            case LF:
+                state = sw_ignore_start;
+                break;
+            }
+            break;
+
+        /* end of ignored part */
+        case sw_ignore_almost_done:
+            switch (ch) {
+            case LF:
+                state = sw_start;
+                break;
+            default:
+                return NGX_ERROR;
+            }
         }
     }

-- 
1.8.0.2