close: add LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION allowed to send
[platform/upstream/libwebsockets.git] / lib / output.c
index a097745..c0ad1f8 100644 (file)
 static int
 lws_0405_frame_mask_generate(struct lws *wsi)
 {
+#if 0
+       wsi->u.ws.mask[0] = 0;
+       wsi->u.ws.mask[1] = 0;
+       wsi->u.ws.mask[2] = 0;
+       wsi->u.ws.mask[3] = 0;
+#else
        int n;
-
        /* fetch the per-frame nonce */
 
-       n = lws_get_random(lws_get_context(wsi), wsi->u.ws.mask_nonce, 4);
+       n = lws_get_random(lws_get_context(wsi), wsi->u.ws.mask, 4);
        if (n != 4) {
                lwsl_parser("Unable to read from random device %s %d\n",
                            SYSTEM_RANDOM_FILEPATH, n);
                return 1;
        }
-
+#endif
        /* start masking from first byte of masking key buffer */
-       wsi->u.ws.frame_mask_index = 0;
+       wsi->u.ws.mask_idx = 0;
 
        return 0;
 }
@@ -90,8 +95,12 @@ LWS_VISIBLE void lwsl_hexdump(void *vbuf, size_t len)
 int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
 {
        struct lws_context *context = lws_get_context(wsi);
+       struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
        size_t real_len = len;
-       int n, m;
+       unsigned int n;
+       int m;
+
+       lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_API_WRITE, 1);
 
        if (!len)
                return 0;
@@ -101,14 +110,25 @@ int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
                return len;
 
        if (wsi->trunc_len && (buf < wsi->trunc_alloc ||
-           buf > (wsi->trunc_alloc + wsi->trunc_len +
-                  wsi->trunc_offset))) {
-               lwsl_err("****** %x Sending new, pending truncated ...\n", wsi);
+           buf > (wsi->trunc_alloc + wsi->trunc_len + wsi->trunc_offset))) {
+               char dump[20];
+               strncpy(dump, (char *)buf, sizeof(dump) - 1);
+               dump[sizeof(dump) - 1] = '\0';
+#if defined(LWS_WITH_ESP8266)
+               lwsl_err("****** %p: Sending new %lu (%s), pending truncated ...\n",
+                        wsi, (unsigned long)len, dump);
+#else
+               lwsl_err("****** %p: Sending new %lu (%s), pending truncated ...\n"
+                        "       It's illegal to do an lws_write outside of\n"
+                        "       the writable callback: fix your code",
+                        wsi, (unsigned long)len, dump);
+#endif
                assert(0);
+
+               return -1;
        }
 
-       m = lws_ext_cb_wsi_active_exts(wsi,
-                       LWS_EXT_CALLBACK_PACKET_TX_DO_SEND, &buf, len);
+       m = lws_ext_cb_active(wsi, LWS_EXT_CB_PACKET_TX_DO_SEND, &buf, len);
        if (m < 0)
                return -1;
        if (m) /* handled */ {
@@ -116,19 +136,36 @@ int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
                goto handle_truncated_send;
        }
 
-       if (!lws_socket_is_valid(wsi->sock))
+       if (!lws_socket_is_valid(wsi->desc.sockfd))
                lwsl_warn("** error invalid sock but expected to send\n");
 
+       /* limit sending */
+       if (wsi->protocol->tx_packet_size)
+               n = wsi->protocol->tx_packet_size;
+       else {
+               n = wsi->protocol->rx_buffer_size;
+               if (!n)
+                       n = context->pt_serv_buf_size;
+       }
+       n += LWS_PRE + 4;
+       if (n > len)
+               n = len;
+#if defined(LWS_WITH_ESP8266)  
+       if (wsi->pending_send_completion) {
+               n = 0;
+               goto handle_truncated_send;
+       }
+#endif
+
        /* nope, send it on the socket directly */
        lws_latency_pre(context, wsi);
-       n = lws_ssl_capable_write(wsi, buf, len);
-       lws_latency(context, wsi, "send lws_issue_raw", n,
-                   (unsigned int)n == len);
+       n = lws_ssl_capable_write(wsi, buf, n);
+       lws_latency(context, wsi, "send lws_issue_raw", n, n == len);
+
+       //lwsl_notice("lws_ssl_capable_write: %d\n", n);
 
        switch (n) {
        case LWS_SSL_CAPABLE_ERROR:
-               lwsl_err("%s: wsi %p: LWS_SSL_CAPABLE_ERROR\n", __func__,
-                        (void *)wsi);
                /* we're going to close, let close know sends aren't possible */
                wsi->socket_is_permanently_unusable = 1;
                return -1;
@@ -143,16 +180,16 @@ handle_truncated_send:
         * we were already handling a truncated send?
         */
        if (wsi->trunc_len) {
-               lwsl_info("%p partial adv %d (vs %d)\n", wsi, n, real_len);
+               lwsl_info("%p partial adv %d (vs %ld)\n", wsi, n, (long)real_len);
                wsi->trunc_offset += n;
                wsi->trunc_len -= n;
 
                if (!wsi->trunc_len) {
-                       lwsl_info("***** %x partial send completed\n", wsi);
+                       lwsl_info("***** %p partial send completed\n", wsi);
                        /* done with it, but don't free it */
                        n = real_len;
                        if (wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE) {
-                               lwsl_info("***** %x signalling to close now\n", wsi);
+                               lwsl_info("***** %p signalling to close now\n", wsi);
                                return -1; /* retry closing now */
                        }
                }
@@ -166,21 +203,15 @@ handle_truncated_send:
                /* what we just sent went out cleanly */
                return n;
 
-       if (n && wsi->u.ws.clean_buffer)
-               /*
-                * This buffer unaffected by extension rewriting.
-                * It means the user code is expected to deal with
-                * partial sends.  (lws knows the header was already
-                * sent, so on next send will just resume sending
-                * payload)
-                */
-                return n;
-
        /*
         * Newly truncated send.  Buffer the remainder (it will get
         * first priority next time the socket is writable)
         */
-       lwsl_info("%p new partial sent %d from %d total\n", wsi, n, real_len);
+       lwsl_debug("%p new partial sent %d from %lu total\n", wsi, n,
+                   (unsigned long)real_len);
+
+       lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_WRITE_PARTIALS, 1);
+       lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_B_PARTIALS_ACCEPTED_PARTS, n);
 
        /*
         *  - if we still have a suitable malloc lying around, use it
@@ -193,8 +224,8 @@ handle_truncated_send:
                wsi->trunc_alloc_len = real_len - n;
                wsi->trunc_alloc = lws_malloc(real_len - n);
                if (!wsi->trunc_alloc) {
-                       lwsl_err("truncated send: unable to malloc %d\n",
-                                real_len - n);
+                       lwsl_err("truncated send: unable to malloc %lu\n",
+                                (unsigned long)(real_len - n));
                        return -1;
                }
        }
@@ -208,87 +239,151 @@ handle_truncated_send:
        return real_len;
 }
 
-/**
- * lws_write() - Apply protocol then write data to client
- * @wsi:       Websocket instance (available from user callback)
- * @buf:       The data to send.  For data being sent on a websocket
- *             connection (ie, not default http), this buffer MUST have
- *             LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE the pointer
- *             and an additional LWS_SEND_BUFFER_POST_PADDING bytes valid
- *             in the buffer after (buf + len).  This is so the protocol
- *             header and trailer data can be added in-situ.
- * @len:       Count of the data bytes in the payload starting from buf
- * @protocol:  Use LWS_WRITE_HTTP to reply to an http connection, and one
- *             of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate
- *             data on a websockets connection.  Remember to allow the extra
- *             bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT
- *             are used.
- *
- *     This function provides the way to issue data back to the client
- *     for both http and websocket protocols.
- *
- *     In the case of sending using websocket protocol, be sure to allocate
- *     valid storage before and after buf as explained above.  This scheme
- *     allows maximum efficiency of sending data and protocol in a single
- *     packet while not burdening the user code with any protocol knowledge.
- *
- *     Return may be -1 for a fatal error needing connection close, or a
- *     positive number reflecting the amount of bytes actually sent.  This
- *     can be less than the requested number of bytes due to OS memory
- *     pressure at any given time.
- */
-
-LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf,
-                         size_t len, enum lws_write_protocol protocol)
+LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf, size_t len,
+                         enum lws_write_protocol wp)
 {
-       int masked7 = wsi->mode == LWSCM_WS_CLIENT;
+       struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
+       int masked7 = (wsi->mode == LWSCM_WS_CLIENT);
        unsigned char is_masked_bit = 0;
        unsigned char *dropmask = NULL;
        struct lws_tokens eff_buf;
-       int post = 0, pre = 0, n;
+       int pre = 0, n;
        size_t orig_len = len;
 
-       if (len == 0 && protocol != LWS_WRITE_CLOSE &&
-           protocol != LWS_WRITE_PING && protocol != LWS_WRITE_PONG) {
-               lwsl_warn("zero length lws_write attempt\n");
-               return 0;
+       if (wsi->parent_carries_io) {
+               struct lws_write_passthru pas;
+
+               pas.buf = buf;
+               pas.len = len;
+               pas.wp = wp;
+               pas.wsi = wsi;
+
+               if (wsi->parent->protocol->callback(wsi->parent,
+                               LWS_CALLBACK_CHILD_WRITE_VIA_PARENT,
+                               wsi->parent->user_space,
+                               (void *)&pas, 0))
+                       return 1;
+
+               return len;
+       }
+
+       lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_API_LWS_WRITE, 1);
+
+       if ((int)len < 0) {
+               lwsl_err("%s: suspicious len int %d, ulong %lu\n", __func__,
+                               (int)len, (unsigned long)len);
+               return -1;
        }
 
-       if (protocol == LWS_WRITE_HTTP ||
-           protocol == LWS_WRITE_HTTP_FINAL ||
-           protocol == LWS_WRITE_HTTP_HEADERS)
+       lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_B_WRITE, len);
+
+#ifdef LWS_WITH_ACCESS_LOG
+       wsi->access_log.sent += len;
+#endif
+       if (wsi->vhost)
+               wsi->vhost->conn_stats.tx += len;
+
+       if (wsi->state == LWSS_ESTABLISHED && wsi->u.ws.tx_draining_ext) {
+               /* remove us from the list */
+               struct lws **w = &pt->tx_draining_ext_list;
+
+       //      lwsl_notice("%s: TX EXT DRAINING: Remove from list\n", __func__);
+               wsi->u.ws.tx_draining_ext = 0;
+               /* remove us from context draining ext list */
+               while (*w) {
+                       if (*w == wsi) {
+                               *w = wsi->u.ws.tx_draining_ext_list;
+                               break;
+                       }
+                       w = &((*w)->u.ws.tx_draining_ext_list);
+               }
+               wsi->u.ws.tx_draining_ext_list = NULL;
+               wp = (wsi->u.ws.tx_draining_stashed_wp & 0xc0) |
+                               LWS_WRITE_CONTINUATION;
+
+               lwsl_ext("FORCED draining wp to 0x%02X\n", wp);
+       }
+
+       lws_restart_ws_ping_pong_timer(wsi);
+
+       if (wp == LWS_WRITE_HTTP ||
+           wp == LWS_WRITE_HTTP_FINAL ||
+           wp == LWS_WRITE_HTTP_HEADERS)
                goto send_raw;
 
-       /* websocket protocol, either binary or text */
+       /* if not in a state to send stuff, then just send nothing */
 
        if (wsi->state != LWSS_ESTABLISHED &&
-           !(wsi->state == LWSS_RETURNED_CLOSE_ALREADY &&
-             protocol == LWS_WRITE_CLOSE))
-               return -1;
+           ((wsi->state != LWSS_RETURNED_CLOSE_ALREADY &&
+             wsi->state != LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION &&
+             wsi->state != LWSS_AWAITING_CLOSE_ACK) ||
+                           wp != LWS_WRITE_CLOSE)) {
+               lwsl_debug("binning\n");
+               return 0;
+       }
 
        /* if we are continuing a frame that already had its header done */
 
-       if (wsi->u.ws.inside_frame)
+       if (wsi->u.ws.inside_frame) {
+               lwsl_debug("INSIDE FRAME\n");
                goto do_more_inside_frame;
+       }
 
        wsi->u.ws.clean_buffer = 1;
 
        /*
         * give a chance to the extensions to modify payload
-        * pre-TX mangling is not allowed to truncate
+        * the extension may decide to produce unlimited payload erratically
+        * (eg, compression extension), so we require only that if he produces
+        * something, it will be a complete fragment of the length known at
+        * the time (just the fragment length known), and if he has
+        * more we will come back next time he is writeable and allow him to
+        * produce more fragments until he's drained.
+        *
+        * This allows what is sent each time it is writeable to be limited to
+        * a size that can be sent without partial sends or blocking, allows
+        * interleaving of control frames and other connection service.
         */
        eff_buf.token = (char *)buf;
        eff_buf.token_len = len;
 
-       switch (protocol) {
+       switch ((int)wp) {
        case LWS_WRITE_PING:
        case LWS_WRITE_PONG:
        case LWS_WRITE_CLOSE:
                break;
        default:
-               if (lws_ext_cb_wsi_active_exts(wsi, LWS_EXT_CALLBACK_PAYLOAD_TX,
-                                              &eff_buf, 0) < 0)
+               lwsl_debug("LWS_EXT_CB_PAYLOAD_TX\n");
+               n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_TX, &eff_buf, wp);
+               if (n < 0)
                        return -1;
+
+               if (n && eff_buf.token_len) {
+                       lwsl_debug("drain len %d\n", (int)eff_buf.token_len);
+                       /* extension requires further draining */
+                       wsi->u.ws.tx_draining_ext = 1;
+                       wsi->u.ws.tx_draining_ext_list = pt->tx_draining_ext_list;
+                       pt->tx_draining_ext_list = wsi;
+                       /* we must come back to do more */
+                       lws_callback_on_writable(wsi);
+                       /*
+                        * keep a copy of the write type for the overall
+                        * action that has provoked generation of these
+                        * fragments, so the last guy can use its FIN state.
+                        */
+                       wsi->u.ws.tx_draining_stashed_wp = wp;
+                       /* this is definitely not actually the last fragment
+                        * because the extension asserted he has more coming
+                        * So make sure this intermediate one doesn't go out
+                        * with a FIN.
+                        */
+                       wp |= LWS_WRITE_NO_FIN;
+               }
+
+               if (eff_buf.token_len && wsi->u.ws.stashed_write_pending) {
+                       wsi->u.ws.stashed_write_pending = 0;
+                       wp = (wp &0xc0) | (int)wsi->u.ws.stashed_write_type;
+               }
        }
 
        /*
@@ -296,16 +391,35 @@ LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf,
         * compression extension, it has already updated its state according
         * to this being issued
         */
-       if ((char *)buf != eff_buf.token)
+       if ((char *)buf != eff_buf.token) {
+               /*
+                * ext might eat it, but not have anything to issue yet.
+                * In that case we have to follow his lead, but stash and
+                * replace the write type that was lost here the first time.
+                */
+               if (len && !eff_buf.token_len) {
+                       if (!wsi->u.ws.stashed_write_pending)
+                               wsi->u.ws.stashed_write_type = (char)wp & 0x3f;
+                       wsi->u.ws.stashed_write_pending = 1;
+                       return len;
+               }
                /*
                 * extension recreated it:
                 * need to buffer this if not all sent
                 */
                wsi->u.ws.clean_buffer = 0;
+       }
 
        buf = (unsigned char *)eff_buf.token;
        len = eff_buf.token_len;
 
+       lwsl_debug("%p / %d\n", buf, (int)len);
+
+       if (!buf) {
+               lwsl_err("null buf (%d)\n", (int)len);
+               return -1;
+       }
+
        switch (wsi->ietf_spec_revision) {
        case 13:
                if (masked7) {
@@ -314,7 +428,7 @@ LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf,
                        is_masked_bit = 0x80;
                }
 
-               switch (protocol & 0xf) {
+               switch (wp & 0xf) {
                case LWS_WRITE_TEXT:
                        n = LWSWSOPC_TEXT_FRAME;
                        break;
@@ -327,18 +441,6 @@ LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf,
 
                case LWS_WRITE_CLOSE:
                        n = LWSWSOPC_CLOSE;
-
-                       /*
-                        * 06+ has a 2-byte status code in network order
-                        * we can do this because we demand post-buf
-                        */
-
-                       if (wsi->u.ws.close_reason) {
-                               /* reason codes count as data bytes */
-                               buf[0] = (unsigned char)(wsi->u.ws.close_reason >> 8);
-                               buf[1] = (unsigned char)wsi->u.ws.close_reason;
-                               len += 2;
-                       }
                        break;
                case LWS_WRITE_PING:
                        n = LWSWSOPC_PING;
@@ -347,11 +449,11 @@ LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf,
                        n = LWSWSOPC_PONG;
                        break;
                default:
-                       lwsl_warn("lws_write: unknown write opc / protocol\n");
+                       lwsl_warn("lws_write: unknown write opc / wp\n");
                        return -1;
                }
 
-               if (!(protocol & LWS_WRITE_NO_FIN))
+               if (!(wp & LWS_WRITE_NO_FIN))
                        n |= 1 << 7;
 
                if (len < 126) {
@@ -393,10 +495,10 @@ do_more_inside_frame:
 
        /*
         * Deal with masking if we are in client -> server direction and
-        * the protocol demands it
+        * the wp demands it
         */
 
-       if (wsi->mode == LWSCM_WS_CLIENT) {
+       if (masked7) {
                if (!wsi->u.ws.inside_frame)
                        if (lws_0405_frame_mask_generate(wsi)) {
                                lwsl_err("frame mask generation failed\n");
@@ -408,19 +510,18 @@ do_more_inside_frame:
                 */
                if (dropmask) { /* never set if already inside frame */
                        for (n = 4; n < (int)len + 4; n++)
-                               dropmask[n] = dropmask[n] ^
-                               wsi->u.ws.mask_nonce[
-                                       (wsi->u.ws.frame_mask_index++) & 3];
+                               dropmask[n] = dropmask[n] ^ wsi->u.ws.mask[
+                                       (wsi->u.ws.mask_idx++) & 3];
 
                        /* copy the frame nonce into place */
-                       memcpy(dropmask, wsi->u.ws.mask_nonce, 4);
+                       memcpy(dropmask, wsi->u.ws.mask, 4);
                }
        }
 
 send_raw:
-       switch (protocol) {
+       switch ((int)wp) {
        case LWS_WRITE_CLOSE:
-/*             lwsl_hexdump(&buf[-pre], len + post); */
+/*             lwsl_hexdump(&buf[-pre], len); */
        case LWS_WRITE_HTTP:
        case LWS_WRITE_HTTP_FINAL:
        case LWS_WRITE_HTTP_HEADERS:
@@ -431,38 +532,39 @@ send_raw:
                        unsigned char flags = 0;
 
                        n = LWS_HTTP2_FRAME_TYPE_DATA;
-                       if (protocol == LWS_WRITE_HTTP_HEADERS) {
+                       if (wp == LWS_WRITE_HTTP_HEADERS) {
                                n = LWS_HTTP2_FRAME_TYPE_HEADERS;
                                flags = LWS_HTTP2_FLAG_END_HEADERS;
                                if (wsi->u.http2.send_END_STREAM)
                                        flags |= LWS_HTTP2_FLAG_END_STREAM;
                        }
 
-                       if ((protocol == LWS_WRITE_HTTP || protocol == LWS_WRITE_HTTP_FINAL) && wsi->u.http.content_length) {
+                       if ((wp == LWS_WRITE_HTTP ||
+                            wp == LWS_WRITE_HTTP_FINAL) &&
+                           wsi->u.http.content_length) {
                                wsi->u.http.content_remain -= len;
-                               lwsl_info("%s: content_remain = %lu\n", __func__, wsi->u.http.content_remain);
+                               lwsl_info("%s: content_remain = %llu\n", __func__,
+                                         (unsigned long long)wsi->u.http.content_remain);
                                if (!wsi->u.http.content_remain) {
                                        lwsl_info("%s: selecting final write mode\n", __func__);
-                                       protocol = LWS_WRITE_HTTP_FINAL;
+                                       wp = LWS_WRITE_HTTP_FINAL;
                                }
                        }
 
-                       if (protocol == LWS_WRITE_HTTP_FINAL && wsi->u.http2.END_STREAM) {
+                       if (wp == LWS_WRITE_HTTP_FINAL && wsi->u.http2.END_STREAM) {
                                lwsl_info("%s: setting END_STREAM\n", __func__);
                                flags |= LWS_HTTP2_FLAG_END_STREAM;
                        }
 
-                       return lws_http2_frame_write(wsi, n, flags, wsi->u.http2.my_stream_id, len, buf);
+                       return lws_http2_frame_write(wsi, n, flags,
+                                       wsi->u.http2.my_stream_id, len, buf);
                }
 #endif
-               return lws_issue_raw(wsi, (unsigned char *)buf - pre,
-                                                             len + pre + post);
+               return lws_issue_raw(wsi, (unsigned char *)buf - pre, len + pre);
        default:
                break;
        }
 
-       wsi->u.ws.inside_frame = 1;
-
        /*
         * give any active extensions a chance to munge the buffer
         * before send.  We pass in a pointer to an lws_tokens struct
@@ -482,11 +584,12 @@ send_raw:
         * return to the user code how much OF THE USER BUFFER was consumed.
         */
 
-       n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre + post);
+       n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre);
+       wsi->u.ws.inside_frame = 1;
        if (n <= 0)
                return n;
 
-       if (n == (int)len + pre + post) {
+       if (n == (int)len + pre) {
                /* everything in the buffer was handled (or rebuffered...) */
                wsi->u.ws.inside_frame = 0;
                return orig_len;
@@ -499,22 +602,31 @@ send_raw:
         * later.
         */
 
-       return n - (pre + post);
+       return n - pre;
 }
 
 LWS_VISIBLE int lws_serve_http_file_fragment(struct lws *wsi)
 {
        struct lws_context *context = wsi->context;
-       unsigned long amount;
+       struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
+       struct lws_process_html_args args;
+       lws_filepos_t amount, poss;
+       unsigned char *p;
+#if defined(LWS_WITH_RANGES)
+       unsigned char finished = 0;
+#endif
        int n, m;
 
-       while (!lws_send_pipe_choked(wsi)) {
+       // lwsl_notice("%s (trunc len %d)\n", __func__, wsi->trunc_len);
+
+       while (wsi->http2_substream || !lws_send_pipe_choked(wsi)) {
+
                if (wsi->trunc_len) {
                        if (lws_issue_raw(wsi, wsi->trunc_alloc +
                                          wsi->trunc_offset,
                                          wsi->trunc_len) < 0) {
                                lwsl_info("%s: closing\n", __func__);
-                               return -1;
+                               goto file_had_it;
                        }
                        continue;
                }
@@ -522,69 +634,199 @@ LWS_VISIBLE int lws_serve_http_file_fragment(struct lws *wsi)
                if (wsi->u.http.filepos == wsi->u.http.filelen)
                        goto all_sent;
 
-               if (lws_plat_file_read(wsi, wsi->u.http.fd, &amount,
-                                      context->serv_buf,
-                                      sizeof(context->serv_buf)) < 0)
-                       return -1; /* caller will close */
+               n = 0;
+
+               p = pt->serv_buf;
+
+#if defined(LWS_WITH_RANGES)
+               if (wsi->u.http.range.count_ranges && !wsi->u.http.range.inside) {
+
+                       lwsl_notice("%s: doing range start %llu\n", __func__, wsi->u.http.range.start);
+
+                       if ((long long)lws_vfs_file_seek_cur(wsi->u.http.fop_fd,
+                                                  wsi->u.http.range.start -
+                                                  wsi->u.http.filepos) < 0)
+                               goto file_had_it;
+
+                       wsi->u.http.filepos = wsi->u.http.range.start;
+
+                       if (wsi->u.http.range.count_ranges > 1) {
+                               n =  lws_snprintf((char *)p, context->pt_serv_buf_size,
+                                       "_lws\x0d\x0a"
+                                       "Content-Type: %s\x0d\x0a"
+                                       "Content-Range: bytes %llu-%llu/%llu\x0d\x0a"
+                                       "\x0d\x0a",
+                                       wsi->u.http.multipart_content_type,
+                                       wsi->u.http.range.start,
+                                       wsi->u.http.range.end,
+                                       wsi->u.http.range.extent);
+                               p += n;
+                       }
+
+                       wsi->u.http.range.budget = wsi->u.http.range.end -
+                                                  wsi->u.http.range.start + 1;
+                       wsi->u.http.range.inside = 1;
+               }
+#endif
+
+               poss = context->pt_serv_buf_size - n;
 
-               n = (int)amount;
+               /*
+                * if there is a hint about how much we will do well to send at one time,
+                * restrict ourselves to only trying to send that.
+                */
+               if (wsi->protocol->tx_packet_size && poss > wsi->protocol->tx_packet_size)
+                       poss = wsi->protocol->tx_packet_size;
+
+#if defined(LWS_WITH_RANGES)
+               if (wsi->u.http.range.count_ranges) {
+                       if (wsi->u.http.range.count_ranges > 1)
+                               poss -= 7; /* allow for final boundary */
+                       if (poss > wsi->u.http.range.budget)
+                               poss = wsi->u.http.range.budget;
+               }
+#endif
+               if (wsi->sending_chunked) {
+                       /* we need to drop the chunk size in here */
+                       p += 10;
+                       /* allow for the chunk to grow by 128 in translation */
+                       poss -= 10 + 128;
+               }
+
+               if (lws_vfs_file_read(wsi->u.http.fop_fd, &amount, p, poss) < 0)
+                       goto file_had_it; /* caller will close */
+               
+               //lwsl_notice("amount %ld\n", amount);
+
+               if (wsi->sending_chunked)
+                       n = (int)amount;
+               else
+                       n = (p - pt->serv_buf) + (int)amount;
                if (n) {
                        lws_set_timeout(wsi, PENDING_TIMEOUT_HTTP_CONTENT,
-                                       AWAITING_TIMEOUT);
-                       wsi->u.http.filepos += n;
-                       m = lws_write(wsi, context->serv_buf, n,
+                                       context->timeout_secs);
+
+                       if (wsi->sending_chunked) {
+                               args.p = (char *)p;
+                               args.len = n;
+                               args.max_len = (unsigned int)poss + 128;
+                               args.final = wsi->u.http.filepos + n ==
+                                            wsi->u.http.filelen;
+                               if (user_callback_handle_rxflow(
+                                    wsi->vhost->protocols[(int)wsi->protocol_interpret_idx].callback, wsi,
+                                    LWS_CALLBACK_PROCESS_HTML,
+                                    wsi->user_space, &args, 0) < 0)
+                                       goto file_had_it;
+                               n = args.len;
+                               p = (unsigned char *)args.p;
+                       } else
+                               p = pt->serv_buf;
+
+#if defined(LWS_WITH_RANGES)
+                       if (wsi->u.http.range.send_ctr + 1 ==
+                               wsi->u.http.range.count_ranges && // last range
+                           wsi->u.http.range.count_ranges > 1 && // was 2+ ranges (ie, multipart)
+                           wsi->u.http.range.budget - amount == 0) {// final part
+                               n += lws_snprintf((char *)pt->serv_buf + n, 6,
+                                       "_lws\x0d\x0a"); // append trailing boundary
+                               lwsl_debug("added trailing boundary\n");
+                       }
+#endif
+                       m = lws_write(wsi, p, n,
                                      wsi->u.http.filepos == wsi->u.http.filelen ?
-                                       LWS_WRITE_HTTP_FINAL : LWS_WRITE_HTTP);
+                                       LWS_WRITE_HTTP_FINAL :
+                                       LWS_WRITE_HTTP
+                               );
                        if (m < 0)
-                               return -1;
+                               goto file_had_it;
+
+                       wsi->u.http.filepos += amount;
+
+#if defined(LWS_WITH_RANGES)
+                       if (wsi->u.http.range.count_ranges >= 1) {
+                               wsi->u.http.range.budget -= amount;
+                               if (wsi->u.http.range.budget == 0) {
+                                       lwsl_notice("range budget exhausted\n");
+                                       wsi->u.http.range.inside = 0;
+                                       wsi->u.http.range.send_ctr++;
+
+                                       if (lws_ranges_next(&wsi->u.http.range) < 1) {
+                                               finished = 1;
+                                               goto all_sent;
+                                       }
+                               }
+                       }
+#endif
 
-                       if (m != n)
+                       if (m != n) {
                                /* adjust for what was not sent */
-                               if (lws_plat_file_seek_cur(wsi, wsi->u.http.fd,
+                               if (lws_vfs_file_seek_cur(wsi->u.http.fop_fd,
                                                           m - n) ==
                                                             (unsigned long)-1)
-                                       return -1;
+                                       goto file_had_it;
+                       }
                }
 all_sent:
-               if (!wsi->trunc_len && wsi->u.http.filepos == wsi->u.http.filelen) {
+               if ((!wsi->trunc_len && wsi->u.http.filepos == wsi->u.http.filelen)
+#if defined(LWS_WITH_RANGES)
+                   || finished)
+#else
+               )
+#endif
+                    {
                        wsi->state = LWSS_HTTP;
-
                        /* we might be in keepalive, so close it off here */
-                       lws_plat_file_close(wsi, wsi->u.http.fd);
-                       wsi->u.http.fd = LWS_INVALID_FILE;
+                       lws_vfs_file_close(&wsi->u.http.fop_fd);
+                       
+                       lwsl_debug("file completed\n");
 
                        if (wsi->protocol->callback)
                                /* ignore callback returned value */
-                               user_callback_handle_rxflow(
-                                       wsi->protocol->callback, wsi,
-                                       LWS_CALLBACK_HTTP_FILE_COMPLETION,
-                                       wsi->user_space, NULL, 0);
+                               if (user_callback_handle_rxflow(
+                                    wsi->protocol->callback, wsi,
+                                    LWS_CALLBACK_HTTP_FILE_COMPLETION,
+                                    wsi->user_space, NULL, 0) < 0)
+                                       return -1;
+
                        return 1;  /* >0 indicates completed */
                }
        }
 
-       lwsl_info("choked before able to send whole file (post)\n");
        lws_callback_on_writable(wsi);
 
        return 0; /* indicates further processing must be done */
+
+file_had_it:
+       lws_vfs_file_close(&wsi->u.http.fop_fd);
+
+       return -1;
 }
 
 #if LWS_POSIX
 LWS_VISIBLE int
 lws_ssl_capable_read_no_ssl(struct lws *wsi, unsigned char *buf, int len)
 {
+       struct lws_context *context = wsi->context;
+       struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
        int n;
 
-       n = recv(wsi->sock, (char *)buf, len, 0);
-       if (n >= 0)
+       lws_stats_atomic_bump(context, pt, LWSSTATS_C_API_READ, 1);
+
+       n = recv(wsi->desc.sockfd, (char *)buf, len, 0);
+       if (n >= 0) {
+               if (wsi->vhost)
+                       wsi->vhost->conn_stats.rx += n;
+               lws_stats_atomic_bump(context, pt, LWSSTATS_B_READ, n);
+               lws_restart_ws_ping_pong_timer(wsi);
                return n;
+       }
 #if LWS_POSIX
        if (LWS_ERRNO == LWS_EAGAIN ||
            LWS_ERRNO == LWS_EWOULDBLOCK ||
            LWS_ERRNO == LWS_EINTR)
                return LWS_SSL_CAPABLE_MORE_SERVICE;
 #endif
-       lwsl_warn("error on reading from skt\n");
+       lwsl_notice("error on reading from skt : %d\n", LWS_ERRNO);
        return LWS_SSL_CAPABLE_ERROR;
 }
 
@@ -594,15 +836,17 @@ lws_ssl_capable_write_no_ssl(struct lws *wsi, unsigned char *buf, int len)
        int n = 0;
 
 #if LWS_POSIX
-       n = send(wsi->sock, (char *)buf, len, MSG_NOSIGNAL);
+       n = send(wsi->desc.sockfd, (char *)buf, len, MSG_NOSIGNAL);
+//     lwsl_info("%s: sent len %d result %d", __func__, len, n);
        if (n >= 0)
                return n;
 
        if (LWS_ERRNO == LWS_EAGAIN ||
            LWS_ERRNO == LWS_EWOULDBLOCK ||
            LWS_ERRNO == LWS_EINTR) {
-               if (LWS_ERRNO == LWS_EWOULDBLOCK)
+               if (LWS_ERRNO == LWS_EWOULDBLOCK) {
                        lws_set_blocking_send(wsi);
+               }
 
                return LWS_SSL_CAPABLE_MORE_SERVICE;
        }
@@ -614,7 +858,7 @@ lws_ssl_capable_write_no_ssl(struct lws *wsi, unsigned char *buf, int len)
        // !!!
 #endif
 
-       lwsl_debug("ERROR writing len %d to skt %d\n", len, n);
+       lwsl_debug("ERROR writing len %d to skt fd %d err %d / errno %d\n", len, wsi->desc.sockfd, n, LWS_ERRNO);
        return LWS_SSL_CAPABLE_ERROR;
 }
 #endif
@@ -622,5 +866,9 @@ LWS_VISIBLE int
 lws_ssl_pending_no_ssl(struct lws *wsi)
 {
        (void)wsi;
+#if defined(LWS_WITH_ESP32)
+       return 100;
+#else
        return 0;
+#endif
 }