FastCGI: combining headers with identical names (ticket #1724).

FastCGI responder is expected to receive CGI/1.1 environment variables
in the parameters (see section "6.2 Responder" of the FastCGI specification).
Obviously enough, there cannot be multiple environment variables with
the same name.

Further, CGI specification (RFC 3875, section "4.1.18. Protocol-Specific
Meta-Variables") explicitly requires to combine headers: "If multiple
header fields with the same field-name are received then the server MUST
rewrite them as a single value having the same semantics".

1 files changed, 55 insertions, 11 deletions

diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index 4a8dc338e..17b7e83a3 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -835,14 +835,14 @@ static ngx_int_t
 ngx_http_fastcgi_create_request(ngx_http_request_t *r)
 {
     off_t                         file_pos;
-    u_char                        ch, *pos, *lowcase_key;
+    u_char                        ch, sep, *pos, *lowcase_key;
     size_t                        size, len, key_len, val_len, padding,
                                   allocated;
     ngx_uint_t                    i, n, next, hash, skip_empty, header_params;
     ngx_buf_t                    *b;
     ngx_chain_t                  *cl, *body;
     ngx_list_part_t              *part;
-    ngx_table_elt_t              *header, **ignored;
+    ngx_table_elt_t              *header, *hn, **ignored;
     ngx_http_upstream_t          *u;
     ngx_http_script_code_pt       code;
     ngx_http_script_engine_t      e, le;
@@ -900,7 +900,11 @@ ngx_http_fastcgi_create_request(ngx_http_request_t *r)
         allocated = 0;
         lowcase_key = NULL;
 
-        if (params->number) {
+        if (ngx_http_link_multi_headers(r) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        if (params->number || r->headers_in.multi) {
             n = 0;
             part = &r->headers_in.headers.part;
 
@@ -930,6 +934,12 @@ ngx_http_fastcgi_create_request(ngx_http_request_t *r)
                 i = 0;
             }
 
+            for (n = 0; n < header_params; n++) {
+                if (&header[i] == ignored[n]) {
+                    goto next_length;
+                }
+            }
+
             if (params->number) {
                 if (allocated < header[i].key.len) {
                     allocated = header[i].key.len + 16;
@@ -959,15 +969,23 @@ ngx_http_fastcgi_create_request(ngx_http_request_t *r)
                     ignored[header_params++] = &header[i];
                     continue;
                 }
+            }
 
-                n += sizeof("HTTP_") - 1;
+            key_len = sizeof("HTTP_") - 1 + header[i].key.len;
 
-            } else {
-                n = sizeof("HTTP_") - 1 + header[i].key.len;
+            val_len = header[i].value.len;
+
+            for (hn = header[i].next; hn; hn = hn->next) {
+                val_len += hn->value.len + 2;
+                ignored[header_params++] = hn;
             }
 
-            len += ((n > 127) ? 4 : 1) + ((header[i].value.len > 127) ? 4 : 1)
-                + n + header[i].value.len;
+            len += ((key_len > 127) ? 4 : 1) + key_len
+                   + ((val_len > 127) ? 4 : 1) + val_len;
+
+        next_length:
+
+            continue;
         }
     }
 
@@ -1109,7 +1127,7 @@ ngx_http_fastcgi_create_request(ngx_http_request_t *r)
 
             for (n = 0; n < header_params; n++) {
                 if (&header[i] == ignored[n]) {
-                    goto next;
+                    goto next_value;
                 }
             }
 
@@ -1125,6 +1143,11 @@ ngx_http_fastcgi_create_request(ngx_http_request_t *r)
             }
 
             val_len = header[i].value.len;
+
+            for (hn = header[i].next; hn; hn = hn->next) {
+                val_len += hn->value.len + 2;
+            }
+
             if (val_len > 127) {
                 *b->last++ = (u_char) (((val_len >> 24) & 0x7f) | 0x80);
                 *b->last++ = (u_char) ((val_len >> 16) & 0xff);
@@ -1150,13 +1173,34 @@ ngx_http_fastcgi_create_request(ngx_http_request_t *r)
                 *b->last++ = ch;
             }
 
-            b->last = ngx_copy(b->last, header[i].value.data, val_len);
+            b->last = ngx_copy(b->last, header[i].value.data,
+                               header[i].value.len);
+
+            if (header[i].next) {
+
+                if (header[i].key.len == sizeof("Cookie") - 1
+                    && ngx_strncasecmp(header[i].key.data, (u_char *) "Cookie",
+                                       sizeof("Cookie") - 1)
+                       == 0)
+                {
+                    sep = ';';
+
+                } else {
+                    sep = ',';
+                }
+
+                for (hn = header[i].next; hn; hn = hn->next) {
+                    *b->last++ = sep;
+                    *b->last++ = ' ';
+                    b->last = ngx_copy(b->last, hn->value.data, hn->value.len);
+                }
+            }
 
             ngx_log_debug4(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                            "fastcgi param: \"%*s: %*s\"",
                            key_len, b->last - (key_len + val_len),
                            val_len, b->last - val_len);
-        next:
+        next_value:
 
             continue;
         }