CLEANUP: mux-h2: remove stream ID and frame length checks from the frame parsers

It's not convenient to have such structural checks mixed with the ones
related to the stream state. Let's remove all these basic tests that are
already covered once for all when reading the frame header.

diff --git a/src/mux_h2.c b/src/mux_h2.c
index ec5fbcaaf463a7f2a6675eebef9b461343e7f7f4..640b06658fb03d91af009e39bedb448cbe815bb3 100644 (file)
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -1440,7 +1440,8 @@ static void h2c_update_all_ws(struct h2c *h2c, int diff)
 
 /* processes a SETTINGS frame whose payload is <payload> for <plen> bytes, and
  * ACKs it if needed. Returns > 0 on success or zero on missing data. It may
- * return an error in h2c. Described in RFC7540#6.5.
+ * return an error in h2c. The caller must have already verified frame length
+ * and stream ID validity. Described in RFC7540#6.5.
  */
 static int h2c_handle_settings(struct h2c *h2c)
 {
@@ -1455,22 +1456,6 @@ static int h2c_handle_settings(struct h2c *h2c)
                return 1;
        }
 
-       if (h2c->dsi != 0) {
-               error = H2_ERR_PROTOCOL_ERROR;
-               goto fail;
-       }
-
-       if (h2c->dfl % 6) {
-               error = H2_ERR_FRAME_SIZE_ERROR;
-               goto fail;
-       }
-
-       /* that's the limit we can process */
-       if (h2c->dfl > global.tune.bufsize) {
-               error = H2_ERR_FRAME_SIZE_ERROR;
-               goto fail;
-       }
-
        /* process full frame only */
        if (b_data(&h2c->dbuf) < h2c->dfl)
                return 0;
@@ -1560,16 +1545,11 @@ static int h2c_ack_settings(struct h2c *h2c)
 
 /* processes a PING frame and schedules an ACK if needed. The caller must pass
  * the pointer to the payload in <payload>. Returns > 0 on success or zero on
- * missing data. It may return an error in h2c.
+ * missing data. The caller must have already verified frame length
+ * and stream ID validity.
  */
 static int h2c_handle_ping(struct h2c *h2c)
 {
-       /* frame length must be exactly 8 */
-       if (h2c->dfl != 8) {
-               h2c_error(h2c, H2_ERR_FRAME_SIZE_ERROR);
-               return 0;
-       }
-
        /* schedule a response */
        if (!(h2c->dff & H2_F_PING_ACK))
                h2c->st0 = H2_CS_FRAME_A;
@@ -1714,18 +1694,14 @@ static int h2c_ack_ping(struct h2c *h2c)
 
 /* processes a WINDOW_UPDATE frame whose payload is <payload> for <plen> bytes.
  * Returns > 0 on success or zero on missing data. It may return an error in
- * h2c or h2s. Described in RFC7540#6.9.
+ * h2c or h2s. The caller must have already verified frame length and stream ID
+ * validity. Described in RFC7540#6.9.
  */
 static int h2c_handle_window_update(struct h2c *h2c, struct h2s *h2s)
 {
        int32_t inc;
        int error;
 
-       if (h2c->dfl != 4) {
-               error = H2_ERR_FRAME_SIZE_ERROR;
-               goto conn_err;
-       }
-
        /* process full frame only */
        if (b_data(&h2c->dbuf) < h2c->dfl)
                return 0;
@@ -1785,24 +1761,14 @@ static int h2c_handle_window_update(struct h2c *h2c, struct h2s *h2s)
 }
 
 /* processes a GOAWAY frame, and signals all streams whose ID is greater than
- * the last ID. Returns > 0 on success or zero on missing data. It may return
- * an error in h2c. Described in RFC7540#6.8.
+ * the last ID. Returns > 0 on success or zero on missing data. The caller must
+ * have already verified frame length and stream ID validity. Described in
+ * RFC7540#6.8.
  */
 static int h2c_handle_goaway(struct h2c *h2c)
 {
-       int error;
        int last;
 
-       if (h2c->dsi != 0) {
-               error = H2_ERR_PROTOCOL_ERROR;
-               goto conn_err;
-       }
-
-       if (h2c->dfl < 8) {
-               error = H2_ERR_FRAME_SIZE_ERROR;
-               goto conn_err;
-       }
-
        /* process full frame only */
        if (b_data(&h2c->dbuf) < h2c->dfl)
                return 0;
@@ -1813,64 +1779,33 @@ static int h2c_handle_goaway(struct h2c *h2c)
        if (h2c->last_sid < 0)
                h2c->last_sid = last;
        return 1;
-
- conn_err:
-       h2c_error(h2c, error);
-       return 0;
 }
 
 /* processes a PRIORITY frame, and either skips it or rejects if it is
- * invalid. Returns > 0 on success or zero on missing data. It may return
- * an error in h2c. Described in RFC7540#6.3.
+ * invalid. Returns > 0 on success or zero on missing data. It may return an
+ * error in h2c. The caller must have already verified frame length and stream
+ * ID validity. Described in RFC7540#6.3.
  */
 static int h2c_handle_priority(struct h2c *h2c)
 {
-       int error;
-
-       if (h2c->dsi == 0) {
-               error = H2_ERR_PROTOCOL_ERROR;
-               goto conn_err;
-       }
-
-       if (h2c->dfl != 5) {
-               error = H2_ERR_FRAME_SIZE_ERROR;
-               goto conn_err;
-       }
-
        /* process full frame only */
        if (b_data(&h2c->dbuf) < h2c->dfl)
                return 0;
 
        if (h2_get_n32(&h2c->dbuf, 0) == h2c->dsi) {
                /* 7540#5.3 : can't depend on itself */
-               error = H2_ERR_PROTOCOL_ERROR;
-               goto conn_err;
+               h2c_error(h2c, H2_ERR_PROTOCOL_ERROR);
+               return 0;
        }
        return 1;
-
- conn_err:
-       h2c_error(h2c, error);
-       return 0;
 }
 
 /* processes an RST_STREAM frame, and sets the 32-bit error code on the stream.
- * Returns > 0 on success or zero on missing data. It may return an error in
- * h2c. Described in RFC7540#6.4.
+ * Returns > 0 on success or zero on missing data. The caller must have already
+ * verified frame length and stream ID validity. Described in RFC7540#6.4.
  */
 static int h2c_handle_rst_stream(struct h2c *h2c, struct h2s *h2s)
 {
-       int error;
-
-       if (h2c->dsi == 0) {
-               error = H2_ERR_PROTOCOL_ERROR;
-               goto conn_err;
-       }
-
-       if (h2c->dfl != 4) {
-               error = H2_ERR_FRAME_SIZE_ERROR;
-               goto conn_err;
-       }
-
        /* process full frame only */
        if (b_data(&h2c->dbuf) < h2c->dfl)
                return 0;
@@ -1889,10 +1824,6 @@ static int h2c_handle_rst_stream(struct h2c *h2c, struct h2s *h2s)
 
        h2s->flags |= H2_SF_RST_RCVD;
        return 1;
-
- conn_err:
-       h2c_error(h2c, error);
-       return 0;
 }
 
 /* processes a HEADERS frame. Returns h2s on success or NULL on missing data.
@@ -1909,13 +1840,6 @@ static struct h2s *h2c_frt_handle_headers(struct h2c *h2c, struct h2s *h2s)
        uint32_t flags = 0;
        int error;
 
-       if (!h2c->dfl) {
-               /* RFC7540#4.2 */
-               error = H2_ERR_FRAME_SIZE_ERROR; // empty headers frame!
-               sess_log(h2c->conn->owner);
-               goto conn_err;
-       }
-
        if (!b_size(&h2c->dbuf))
                return NULL; // empty buffer
 
@@ -2020,13 +1944,6 @@ static struct h2s *h2c_bck_handle_headers(struct h2c *h2c, struct h2s *h2s)
 {
        int error;
 
-       if (!h2c->dfl) {
-               /* RFC7540#4.2 */
-               error = H2_ERR_FRAME_SIZE_ERROR; // empty headers frame!
-               sess_log(h2c->conn->owner);
-               goto conn_err;
-       }
-
        if (!b_size(&h2c->dbuf))
                return NULL; // empty buffer
 
@@ -2069,10 +1986,6 @@ static struct h2s *h2c_bck_handle_headers(struct h2c *h2c, struct h2s *h2s)
                h2s_close(h2s);
 
        return h2s;
-
- conn_err:
-       h2c_error(h2c, error);
-       return NULL;
 }
 
 /* processes a DATA frame. Returns > 0 on success or zero on missing data.
@@ -2094,12 +2007,6 @@ static int h2c_frt_handle_data(struct h2c *h2c, struct h2s *h2s)
 
        /* now either the frame is complete or the buffer is complete */
 
-       if (!h2c->dsi) {
-               /* RFC7540#6.1 */
-               error = H2_ERR_PROTOCOL_ERROR;
-               goto conn_err;
-       }
-
        if (h2s->st != H2_SS_OPEN && h2s->st != H2_SS_HLOC) {
                /* RFC7540#6.1 */
                error = H2_ERR_STREAM_CLOSED;
@@ -2156,10 +2063,6 @@ static int h2c_frt_handle_data(struct h2c *h2c, struct h2s *h2s)
 
        return 1;
 
- conn_err:
-       h2c_error(h2c, error);
-       return 0;
-
  strm_err:
        h2s_error(h2s, error);
        h2c->st0 = H2_CS_FRAME_E;
@@ -2509,15 +2412,6 @@ static void h2_process_demux(struct h2c *h2c)
                                ret = h2c_handle_goaway(h2c);
                        break;
 
-               case H2_FT_PUSH_PROMISE:
-                       /* not permitted here, RFC7540#5.1 */
-                       h2c_error(h2c, H2_ERR_PROTOCOL_ERROR);
-                       if (!h2c->nb_streams) {
-                               /* only log if no other stream can report the error */
-                               sess_log(h2c->conn->owner);
-                       }
-                       break;
-
                        /* implement all extra frame types here */
                default:
                        /* drop frames that we ignore. They may be larger than