Improved logging of invalid headers.

In 71edd9192f24 logging of invalid headers which were rejected with the
NGX_HTTP_PARSE_INVALID_HEADER error was restricted to just the "client
sent invalid header line" message, without any attempts to log the header
itself.

This patch returns logging of the header up to the invalid character and
the character itself.  The r->header_end pointer is now properly set
in all cases to make logging possible.

The same logging is also introduced when parsing headers from upstream
servers.

6 files changed, 28 insertions, 13 deletions

diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index 5191880e3..69ac0f72c 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -2019,10 +2019,12 @@ ngx_http_fastcgi_process_header(ngx_http_request_t *r)
                 break;
             }
 
-            /* there was error while a header line parsing */
+            /* rc == NGX_HTTP_PARSE_INVALID_HEADER */
 
-            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
-                          "upstream sent invalid header");
+            ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
+                          "upstream sent invalid header: \"%*s\\x%02xd...\"",
+                          r->header_end - r->header_name_start,
+                          r->header_name_start, *r->header_end);
 
             return NGX_HTTP_UPSTREAM_INVALID_HEADER;
         }
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index d82f5ea21..368297e77 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -2019,10 +2019,12 @@ ngx_http_proxy_process_header(ngx_http_request_t *r)
             return NGX_AGAIN;
         }
 
-        /* there was error while a header line parsing */
+        /* rc == NGX_HTTP_PARSE_INVALID_HEADER */
 
-        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
-                      "upstream sent invalid header");
+        ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
+                      "upstream sent invalid header: \"%*s\\x%02xd...\"",
+                      r->header_end - r->header_name_start,
+                      r->header_name_start, *r->header_end);
 
         return NGX_HTTP_UPSTREAM_INVALID_HEADER;
     }
diff --git a/src/http/modules/ngx_http_scgi_module.c b/src/http/modules/ngx_http_scgi_module.c
index 600999c88..570713df9 100644
--- a/src/http/modules/ngx_http_scgi_module.c
+++ b/src/http/modules/ngx_http_scgi_module.c
@@ -1140,10 +1140,12 @@ ngx_http_scgi_process_header(ngx_http_request_t *r)
             return NGX_AGAIN;
         }
 
-        /* there was error while a header line parsing */
+        /* rc == NGX_HTTP_PARSE_INVALID_HEADER */
 
-        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
-                      "upstream sent invalid header");
+        ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
+                      "upstream sent invalid header: \"%*s\\x%02xd...\"",
+                      r->header_end - r->header_name_start,
+                      r->header_name_start, *r->header_end);
 
         return NGX_HTTP_UPSTREAM_INVALID_HEADER;
     }
diff --git a/src/http/modules/ngx_http_uwsgi_module.c b/src/http/modules/ngx_http_uwsgi_module.c
index 655be98c7..40a06c78e 100644
--- a/src/http/modules/ngx_http_uwsgi_module.c
+++ b/src/http/modules/ngx_http_uwsgi_module.c
@@ -1361,10 +1361,12 @@ ngx_http_uwsgi_process_header(ngx_http_request_t *r)
             return NGX_AGAIN;
         }
 
-        /* there was error while a header line parsing */
+        /* rc == NGX_HTTP_PARSE_INVALID_HEADER */
 
-        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
-                      "upstream sent invalid header");
+        ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
+                      "upstream sent invalid header: \"%*s\\x%02xd...\"",
+                      r->header_end - r->header_name_start,
+                      r->header_name_start, *r->header_end);
 
         return NGX_HTTP_UPSTREAM_INVALID_HEADER;
     }
diff --git a/src/http/ngx_http_parse.c b/src/http/ngx_http_parse.c
index 6af326dee..6460da293 100644
--- a/src/http/ngx_http_parse.c
+++ b/src/http/ngx_http_parse.c
@@ -894,6 +894,7 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
                 }
 
                 if (ch <= 0x20 || ch == 0x7f || ch == ':') {
+                    r->header_end = p;
                     return NGX_HTTP_PARSE_INVALID_HEADER;
                 }
 
@@ -962,6 +963,7 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
             }
 
             if (ch <= 0x20 || ch == 0x7f) {
+                r->header_end = p;
                 return NGX_HTTP_PARSE_INVALID_HEADER;
             }
 
@@ -984,6 +986,7 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
                 r->header_end = p;
                 goto done;
             case '\0':
+                r->header_end = p;
                 return NGX_HTTP_PARSE_INVALID_HEADER;
             default:
                 r->header_start = p;
@@ -1007,6 +1010,7 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
                 r->header_end = p;
                 goto done;
             case '\0':
+                r->header_end = p;
                 return NGX_HTTP_PARSE_INVALID_HEADER;
             }
             break;
@@ -1022,6 +1026,7 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
             case LF:
                 goto done;
             case '\0':
+                r->header_end = p;
                 return NGX_HTTP_PARSE_INVALID_HEADER;
             default:
                 state = sw_value;
diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 7956610c4..2e7c30fb6 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -1522,7 +1522,9 @@ ngx_http_process_request_headers(ngx_event_t *rev)
         /* rc == NGX_HTTP_PARSE_INVALID_HEADER */
 
         ngx_log_error(NGX_LOG_INFO, c->log, 0,
-                      "client sent invalid header line");
+                      "client sent invalid header line: \"%*s\\x%02xd...\"",
+                      r->header_end - r->header_name_start,
+                      r->header_name_start, *r->header_end);
 
         ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
         break;