nghttp2_sesson_mem_recv: Process incoming data in streaming fashion

Now incoming data is processed in very small buffer (up to 8 bytes)
using state machine. GOAWAY debug data can get to 16K - 1, and we
don't have callback for it. Since we don't want to buffer that
amount of data just for debugging, we currently discard it.
This change also makes parse_error callback not function.
It probably be removed from API.

lib/nghttp2_frame.c

@@ -270,6 +270,25 @@ int nghttp2_frame_unpack_headers_without_nv(nghttp2_headers *frame,
   return 0;
 }
 
+int nghttp2_frame_unpack_headers_payload(nghttp2_headers *frame,
+                                         const uint8_t *payload,
+                                         size_t payloadlen)
+{
+  /* TODO Return error if header continuation is used for now */
+  if((frame->hd.flags & NGHTTP2_FLAG_END_HEADERS) == 0) {
+    return NGHTTP2_ERR_PROTO;
+  }
+  if(frame->hd.flags & NGHTTP2_FLAG_PRIORITY) {
+    assert(payloadlen == 4);
+    frame->pri = nghttp2_get_uint32(payload) & NGHTTP2_PRIORITY_MASK;
+  } else {
+    frame->pri = NGHTTP2_PRI_DEFAULT;
+  }
+  frame->nva = NULL;
+  frame->nvlen = 0;
+  return 0;
+}
+
 ssize_t nghttp2_frame_pack_priority(uint8_t **buf_ptr, size_t *buflen_ptr,
                                     nghttp2_priority *frame)
 {
@@ -295,7 +314,13 @@ int nghttp2_frame_unpack_priority(nghttp2_priority *frame,
   nghttp2_frame_unpack_frame_hd(&frame->hd, head);
   frame->pri = nghttp2_get_uint32(payload) & NGHTTP2_PRIORITY_MASK;
   return 0;
+}
 
+void nghttp2_frame_unpack_priority_payload(nghttp2_priority *frame,
+                                           const uint8_t *payload,
+                                           size_t payloadlen)
+{
+  frame->pri = nghttp2_get_uint32(payload) & NGHTTP2_PRIORITY_MASK;
 }
 
 ssize_t nghttp2_frame_pack_rst_stream(uint8_t **buf_ptr, size_t *buflen_ptr,
@@ -325,6 +350,13 @@ int nghttp2_frame_unpack_rst_stream(nghttp2_rst_stream *frame,
   return 0;
 }
 
+void nghttp2_frame_unpack_rst_stream_payload(nghttp2_rst_stream *frame,
+                                             const uint8_t *payload,
+                                             size_t payloadlen)
+{
+  frame->error_code = nghttp2_get_uint32(payload);
+}
+
 ssize_t nghttp2_frame_pack_settings(uint8_t **buf_ptr, size_t *buflen_ptr,
                                     nghttp2_settings *frame)
 {
@@ -371,6 +403,29 @@ int nghttp2_frame_unpack_settings(nghttp2_settings *frame,
   return 0;
 }
 
+int nghttp2_frame_unpack_settings_payload2(nghttp2_settings *frame,
+                                           nghttp2_settings_entry *iv,
+                                           size_t niv)
+{
+  size_t payloadlen = niv * sizeof(nghttp2_settings_entry);
+
+  frame->iv = malloc(payloadlen);
+  if(frame->iv == NULL) {
+    return NGHTTP2_ERR_NOMEM;
+  }
+  memcpy(frame->iv, iv, payloadlen);
+  frame->niv = niv;
+  return 0;
+}
+
+void nghttp2_frame_unpack_settings_entry(nghttp2_settings_entry *iv,
+                                         const uint8_t *payload)
+{
+  iv->settings_id = nghttp2_get_uint32(&payload[0]) &
+    NGHTTP2_SETTINGS_ID_MASK;
+  iv->value = nghttp2_get_uint32(&payload[4]);
+}
+
 int nghttp2_frame_unpack_settings_payload(nghttp2_settings_entry **iv_ptr,
                                           size_t *niv_ptr,
                                           const uint8_t *payload,
@@ -384,9 +439,7 @@ int nghttp2_frame_unpack_settings_payload(nghttp2_settings_entry **iv_ptr,
   }
   for(i = 0; i < *niv_ptr; ++i) {
     size_t off = i*8;
-    (*iv_ptr)[i].settings_id = nghttp2_get_uint32(&payload[off]) &
-      NGHTTP2_SETTINGS_ID_MASK;
-    (*iv_ptr)[i].value = nghttp2_get_uint32(&payload[4+off]);
+    nghttp2_frame_unpack_settings_entry(&(*iv_ptr)[i], &payload[off]);
   }
   return 0;
 }
@@ -440,6 +493,21 @@ int nghttp2_frame_unpack_push_promise_without_nv(nghttp2_push_promise *frame,
   return 0;
 }
 
+int nghttp2_frame_unpack_push_promise_payload(nghttp2_push_promise *frame,
+                                              const uint8_t *payload,
+                                              size_t payloadlen)
+{
+  /* TODO Return error if header continuation is used for now */
+  if((frame->hd.flags & NGHTTP2_FLAG_END_PUSH_PROMISE) == 0) {
+    return NGHTTP2_ERR_PROTO;
+  }
+  frame->promised_stream_id = nghttp2_get_uint32(payload) &
+    NGHTTP2_STREAM_ID_MASK;
+  frame->nva = NULL;
+  frame->nvlen = 0;
+  return 0;
+}
+
 ssize_t nghttp2_frame_pack_ping(uint8_t **buf_ptr, size_t *buflen_ptr,
                                 nghttp2_ping *frame)
 {
@@ -467,6 +535,12 @@ int nghttp2_frame_unpack_ping(nghttp2_ping *frame,
   return 0;
 }
 
+void nghttp2_frame_unpack_ping_payload(nghttp2_ping *frame,
+                                       const uint8_t *payload,
+                                       size_t payloadlen)
+{
+  memcpy(frame->opaque_data, payload, sizeof(frame->opaque_data));
+}
 
 ssize_t nghttp2_frame_pack_goaway(uint8_t **buf_ptr, size_t *buflen_ptr,
                                   nghttp2_goaway *frame)
@@ -508,6 +582,17 @@ int nghttp2_frame_unpack_goaway(nghttp2_goaway *frame,
   return 0;
 }
 
+void nghttp2_frame_unpack_goaway_payload(nghttp2_goaway *frame,
+                                         const uint8_t *payload,
+                                         size_t payloadlen)
+{
+  frame->last_stream_id = nghttp2_get_uint32(payload) & NGHTTP2_STREAM_ID_MASK;
+  frame->error_code = nghttp2_get_uint32(payload+4);
+  /* TODO Currently we don't buffer debug data */
+  frame->opaque_data = NULL;
+  frame->opaque_data_len = 0;
+}
+
 ssize_t nghttp2_frame_pack_window_update(uint8_t **buf_ptr, size_t *buflen_ptr,
                                          nghttp2_window_update *frame)
 {
@@ -537,6 +622,14 @@ int nghttp2_frame_unpack_window_update(nghttp2_window_update *frame,
   return 0;
 }
 
+void nghttp2_frame_unpack_window_update_payload(nghttp2_window_update *frame,
+                                                const uint8_t *payload,
+                                                size_t payloadlen)
+{
+  frame->window_size_increment = nghttp2_get_uint32(payload) &
+    NGHTTP2_WINDOW_SIZE_INCREMENT_MASK;
+}
+
 nghttp2_settings_entry* nghttp2_frame_iv_copy(const nghttp2_settings_entry *iv,
                                               size_t niv)
 {

lib/nghttp2_frame.h

@@ -161,6 +161,10 @@ int nghttp2_frame_unpack_headers_without_nv(nghttp2_headers *frame,
                                             const uint8_t *payload,
                                             size_t payloadlen);
 
+int nghttp2_frame_unpack_headers_payload(nghttp2_headers *frame,
+                                         const uint8_t *payload,
+                                         size_t payloadlen);
+
 /*
  * Packs PRIORITY frame |frame| in wire format and store it in
  * |*buf_ptr|. The capacity of |*buf_ptr| is |*buflen_ptr|
@@ -189,6 +193,10 @@ int nghttp2_frame_unpack_priority(nghttp2_priority *frame,
                                   const uint8_t *head, size_t headlen,
                                   const uint8_t *payload, size_t payloadlen);
 
+void nghttp2_frame_unpack_priority_payload(nghttp2_priority *frame,
+                                           const uint8_t *payload,
+                                           size_t payloadlen);
+
 /*
  * Packs RST_STREAM frame |frame| in wire frame format and store it in
  * |*buf_ptr|. The capacity of |*buf_ptr| is |*buflen_ptr|
@@ -218,6 +226,10 @@ int nghttp2_frame_unpack_rst_stream(nghttp2_rst_stream *frame,
                                     const uint8_t *head, size_t headlen,
                                     const uint8_t *payload, size_t payloadlen);
 
+void nghttp2_frame_unpack_rst_stream_payload(nghttp2_rst_stream *frame,
+                                             const uint8_t *payload,
+                                             size_t payloadlen);
+
 /*
  * Packs SETTINGS frame |frame| in wire format and store it in
  * |*buf_ptr|. The capacity of |*buf_ptr| is |*buflen_ptr|
@@ -259,6 +271,13 @@ int nghttp2_frame_unpack_settings(nghttp2_settings *frame,
                                   const uint8_t *payload, size_t payloadlen);
 
 
+void nghttp2_frame_unpack_settings_entry(nghttp2_settings_entry *iv,
+                                         const uint8_t *payload);
+
+int nghttp2_frame_unpack_settings_payload2(nghttp2_settings *frame,
+                                           nghttp2_settings_entry *iv,
+                                           size_t niv);
+
 /*
  * Unpacks SETTINGS payload into |*iv_ptr|. The number of entries are
  * assigned to the |*niv_ptr|. This function allocates enough memory
@@ -347,6 +366,10 @@ int nghttp2_frame_unpack_push_promise_without_nv(nghttp2_push_promise *frame,
                                                  const uint8_t *payload,
                                                  size_t payloadlen);
 
+int nghttp2_frame_unpack_push_promise_payload(nghttp2_push_promise *frame,
+                                              const uint8_t *payload,
+                                              size_t payloadlen);
+
 /*
  * Packs PING frame |frame| in wire format and store it in
  * |*buf_ptr|. The capacity of |*buf_ptr| is |*buflen_ptr|
@@ -375,6 +398,10 @@ int nghttp2_frame_unpack_ping(nghttp2_ping *frame,
                               const uint8_t *head, size_t headlen,
                               const uint8_t *payload, size_t payloadlen);
 
+void nghttp2_frame_unpack_ping_payload(nghttp2_ping *frame,
+                                       const uint8_t *payload,
+                                       size_t payloadlen);
+
 /*
  * Packs GOAWAY frame |frame | in wire format and store it in
  * |*buf_ptr|. The capacity of |*buf_ptr| is |*buflen_ptr|
@@ -405,6 +432,10 @@ int nghttp2_frame_unpack_goaway(nghttp2_goaway *frame,
                                 const uint8_t *head, size_t headlen,
                                 const uint8_t *payload, size_t payloadlen);
 
+void nghttp2_frame_unpack_goaway_payload(nghttp2_goaway *frame,
+                                         const uint8_t *payload,
+                                         size_t payloadlen);
+
 /*
  * Packs WINDOW_UPDATE frame |frame| in wire frame format and store it
  * in |*buf_ptr|. The capacity of |*buf_ptr| is |*buflen_ptr|
@@ -434,6 +465,10 @@ int nghttp2_frame_unpack_window_update(nghttp2_window_update *frame,
                                        const uint8_t *payload,
                                        size_t payloadlen);
 
+void nghttp2_frame_unpack_window_update_payload(nghttp2_window_update *frame,
+                                                const uint8_t *payload,
+                                                size_t payloadlen);
+
 /*
  * Initializes HEADERS frame |frame| with given values.  |frame| takes
  * ownership of |nva|, so caller must not free it. If |stream_id| is

lib/nghttp2_int.h

@@ -45,7 +45,9 @@ typedef int (*nghttp2_compar)(const void *lhs, const void *rhs);
    inclusive. */
 typedef enum {
   NGHTTP2_ERR_CREDENTIAL_PENDING = -101,
-  NGHTTP2_ERR_BUFFER_ERROR = - 102
+  NGHTTP2_ERR_BUFFER_ERROR = -102,
+  NGHTTP2_ERR_IGN_HEADER_BLOCK = -103,
+  NGHTTP2_ERR_IGN_PAYLOAD = -104,
 } nghttp2_internal_error;
 
 #endif /* NGHTTP2_INT_H */

lib/nghttp2_session.h

@@ -37,6 +37,7 @@
 #include "nghttp2_stream.h"
 #include "nghttp2_buffer.h"
 #include "nghttp2_outbound_item.h"
+#include "nghttp2_int.h"
 
 /*
  * Option flags.
@@ -72,39 +73,36 @@ typedef struct {
 /* Internal state when receiving incoming frame */
 typedef enum {
   /* Receiving frame header */
-  NGHTTP2_RECV_HEAD,
-  /* Receiving frame payload (comes after length field) */
-  NGHTTP2_RECV_PAYLOAD,
-  /* Receiving frame payload, but the received bytes are discarded. */
-  NGHTTP2_RECV_PAYLOAD_IGN
+  NGHTTP2_IB_READ_HEAD,
+  NGHTTP2_IB_READ_NBYTE,
+  NGHTTP2_IB_READ_HEADER_BLOCK,
+  NGHTTP2_IB_IGN_HEADER_BLOCK,
+  NGHTTP2_IB_IGN_PAYLOAD,
+  NGHTTP2_IB_FRAME_SIZE_ERROR,
+  NGHTTP2_IB_READ_SETTINGS,
+  NGHTTP2_IB_READ_GOAWAY_DEBUG,
+  NGHTTP2_IB_READ_DATA,
+  NGHTTP2_IB_IGN_DATA
 } nghttp2_inbound_state;
 
 typedef struct {
   nghttp2_frame frame;
-  /* Payload for non-DATA frames. */
-  uint8_t *buf;
-  /* How many bytes are filled in headbuf */
-  size_t headbufoff;
-  /* Capacity of buf */
-  size_t bufmax;
-  /* For frames without name/value header block, this is how many
-     bytes are going to filled in buf. For frames with the block, buf
-     only contains bytes that come before ther block, but this value
-     includes the length of the block. buflen <= bufmax must be
-     fulfilled. */
-  size_t buflen;
-  /* length in Length field */
-  size_t payloadlen;
-  /* How many bytes are received for this frame. off <= payloadlen
-     must be fulfilled. */
-  size_t off;
-  /* How many bytes are decompressed inside |buf|. This is used for
-     header decompression. */
-  size_t inflate_offset;
+  /* The received SETTINGS entry. The protocol says that we only cares
+     about the defined settings ID. If unknown ID is received, it is
+     subject to connection error */
+  nghttp2_settings_entry iv[5];
+  /* The number of entry filled in |iv| */
+  size_t niv;
+  /* How many bytes we still need to receive in the |buf| */
+  size_t left;
+  /* How many bytes we still need to receive for current frame */
+  size_t payloadleft;
   nghttp2_inbound_state state;
-  /* Error code */
+  /* TODO, remove this. Error code */
   int error_code;
-  uint8_t headbuf[NGHTTP2_FRAME_HEAD_LENGTH];
+  uint8_t buf[8];
+  /* How many bytes have been written to |buf| */
+  uint8_t buflen;
 } nghttp2_inbound_frame;
 
 typedef enum {
@@ -131,9 +129,6 @@ struct nghttp2_session {
   /* Sequence number of outbound frame to maintain the order of
      enqueue if priority is equal. */
   int64_t next_seq;
-  /* Buffer used to store inflated name/value pairs in wire format
-     temporarily on pack/unpack. */
-  uint8_t *nvbuf;
   void *user_data;
   /* In-flight SETTINGS values. NULL does not necessarily mean there
      is no in-flight SETTINGS. */
@@ -358,6 +353,15 @@ int nghttp2_session_close_stream_if_shut_rdwr(nghttp2_session *session,
                                               nghttp2_stream *stream);
 
 
+int nghttp2_session_end_request_headers_received(nghttp2_session *session,
+                                                 nghttp2_frame *frame);
+
+int nghttp2_session_end_response_headers_received(nghttp2_session *session,
+                                                  nghttp2_frame *frame);
+
+int nghttp2_session_end_headers_received(nghttp2_session *session,
+                                         nghttp2_frame *frame);
+
 int nghttp2_session_on_request_headers_received(nghttp2_session *session,
                                                 nghttp2_frame *frame);