reflect send completeness in lws_write return

[platform/upstream/libwebsockets.git] / lib / output.c

diff --git a/lib/output.c b/lib/output.c
index 35389c2..2d8c369 100644 (file)
--- a/lib/output.c
+++ b/lib/output.c
@@ -90,6 +90,10 @@ void lwsl_hexdump(void *vbuf, size_t len)
 
 #endif
 
+/*
+ * notice this returns number of bytes sent, or -1
+ */
+
 int lws_issue_raw(struct libwebsocket *wsi, unsigned char *buf, size_t len)
 {
        struct libwebsocket_context *context = wsi->protocol->owning_server;
@@ -117,7 +121,7 @@ int lws_issue_raw(struct libwebsocket *wsi, unsigned char *buf, size_t len)
                }
                if (m) /* handled */ {
 /*                     lwsl_ext("ext sent it\n"); */
-                       return 0;
+                       return m;
                }
        }
 #endif
@@ -146,14 +150,14 @@ int lws_issue_raw(struct libwebsocket *wsi, unsigned char *buf, size_t len)
 #endif
                n = send(wsi->sock, buf, len, MSG_NOSIGNAL);
                lws_latency(context, wsi, "send lws_issue_raw", n, n == len);
-               if (n != len) {
+               if (n < 0) {
                        lwsl_debug("ERROR writing len %d to skt %d\n", len, n);
                        return -1;
                }
 #ifdef LWS_OPENSSL_SUPPORT
        }
 #endif
-       return 0;
+       return n;
 }
 
 #ifdef LWS_NO_EXTENSIONS
@@ -210,10 +214,21 @@ lws_issue_raw_ext_access(struct libwebsocket *wsi,
 
                /* assuming they left us something to send, send it */
 
-               if (eff_buf.token_len)
-                       if (lws_issue_raw(wsi, (unsigned char *)eff_buf.token,
-                                                           eff_buf.token_len))
+               if (eff_buf.token_len) {
+                       n = lws_issue_raw(wsi, (unsigned char *)eff_buf.token,
+                                                           eff_buf.token_len);
+                       if (n < 0)
+                               return -1;
+                       /*
+                        * Keep amount spilled small to minimize chance of this
+                        */
+                       if (n != eff_buf.token_len) {
+                               lwsl_err("Unable to spill ext %d vs %s\n",
+                                                         eff_buf.token_len, n);
                                return -1;
+                       }
+
+               }
 
                lwsl_parser("written %d bytes to client\n", eff_buf.token_len);
 
@@ -247,7 +262,7 @@ lws_issue_raw_ext_access(struct libwebsocket *wsi,
                ret = 0;
        }
 
-       return 0;
+       return len;
 }
 #endif
 
@@ -274,6 +289,11 @@ lws_issue_raw_ext_access(struct libwebsocket *wsi,
  *     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.
  */
 
 int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf,
@@ -285,6 +305,7 @@ int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf,
        int masked7 = wsi->mode == LWS_CONNMODE_WS_CLIENT;
        unsigned char *dropmask = NULL;
        unsigned char is_masked_bit = 0;
+       size_t orig_len = len;
 #ifndef LWS_NO_EXTENSIONS
        struct lws_tokens eff_buf;
        int m;
@@ -423,7 +444,7 @@ int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf,
 
                if (libwebsocket_0405_frame_mask_generate(wsi)) {
                        lwsl_err("lws_write: frame mask generation failed\n");
-                       return 1;
+                       return -1;
                }
 
                /*
@@ -453,11 +474,8 @@ send_raw:
        case LWS_WRITE_HTTP:
        case LWS_WRITE_PONG:
        case LWS_WRITE_PING:
-               if (lws_issue_raw(wsi, (unsigned char *)buf - pre,
-                                                             len + pre + post))
-                       return -1;
-
-               return 0;
+               return lws_issue_raw(wsi, (unsigned char *)buf - pre,
+                                                             len + pre + post);
        default:
                break;
        }
@@ -476,26 +494,36 @@ send_raw:
         * callback returns 1 in case it wants to spill more buffers
         */
 
-       return lws_issue_raw_ext_access(wsi, buf - pre, len + pre + post);
+       n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre + post);
+       if (n < 0)
+               return n;
+
+       return orig_len - ((len - pre + post) -n );
 }
 
 int libwebsockets_serve_http_file_fragment(
                struct libwebsocket_context *context, struct libwebsocket *wsi)
 {
        int ret = 0;
-       int n;
+       int n, m;
 
        while (!lws_send_pipe_choked(wsi)) {
                n = read(wsi->u.http.fd, context->service_buffer,
                                               sizeof(context->service_buffer));
                if (n > 0) {
-                       libwebsocket_write(wsi, context->service_buffer, n,
+                       m = libwebsocket_write(wsi, context->service_buffer, n,
                                                                LWS_WRITE_HTTP);
+                       if (m < 0)
+                               return -1;
+
                        wsi->u.http.filepos += n;
+                       if (m != n)
+                               /* adjust for what was not sent */
+                               lseek(wsi->u.http.fd, m - n, SEEK_CUR);
                }
 
                if (n < 0)
-                       return 1; /* caller will close */
+                       return -1; /* caller will close */
 
                if (n < sizeof(context->service_buffer) ||
                                wsi->u.http.filepos == wsi->u.http.filelen) {
@@ -552,6 +580,7 @@ int libwebsockets_serve_http_file(struct libwebsocket_context *context,
                 "HTTP/1.0 400 Bad\x0d\x0aServer: libwebsockets\x0d\x0a\x0d\x0a"
                );
                wsi->u.http.fd = 0;
+               /* too small to care about partial, closing anyway */
                libwebsocket_write(wsi, context->service_buffer,
                                p - context->service_buffer, LWS_WRITE_HTTP);
 
@@ -569,8 +598,10 @@ int libwebsockets_serve_http_file(struct libwebsocket_context *context,
 
        ret = libwebsocket_write(wsi, context->service_buffer,
                                   p - context->service_buffer, LWS_WRITE_HTTP);
-       if (ret)
+       if (ret != (p - context->service_buffer)) {
+               lwsl_err("_write returned %d from %d\n", ret, (p - context->service_buffer));
                return -1;
+       }
 
        wsi->u.http.filepos = 0;
        wsi->state = WSI_STATE_HTTP_ISSUING_FILE;