Improve websock response / error handling

index 5a3badbec2..f5fac5b422 100644
@@ -25,6 +25,8 @@
 #include "crypto/hash.h"
 #include "trace.h"
 
+#include <time.h>
+
 
 /* Max amount to allow in rawinput/rawoutput buffers */
 #define QIO_CHANNEL_WEBSOCK_MAX_BUFFER 8192

@@ -44,13 +46,40 @@
 #define QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE "Upgrade"
 #define QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET "websocket"
 
-#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE  \
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \
+    "Server: QEMU VNC\r\n"                       \
+    "Date: %s\r\n"
+
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_OK    \
     "HTTP/1.1 101 Switching Protocols\r\n"      \
+    QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON    \
     "Upgrade: websocket\r\n"                    \
     "Connection: Upgrade\r\n"                   \
     "Sec-WebSocket-Accept: %s\r\n"              \
     "Sec-WebSocket-Protocol: binary\r\n"        \
     "\r\n"
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_NOT_FOUND \
+    "HTTP/1.1 404 Not Found\r\n"                    \
+    QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON        \
+    "Connection: close\r\n"                         \
+    "\r\n"
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST \
+    "HTTP/1.1 400 Bad Request\r\n"                    \
+    QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON          \
+    "Connection: close\r\n"                           \
+    "Sec-WebSocket-Version: "                         \
+    QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION             \
+    "\r\n"
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_SERVER_ERR \
+    "HTTP/1.1 500 Internal Server Error\r\n"         \
+    QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON         \
+    "Connection: close\r\n"                          \
+    "\r\n"
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_TOO_LARGE  \
+    "HTTP/1.1 403 Request Entity Too Large\r\n"      \
+    QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON         \
+    "Connection: close\r\n"                          \
+    "\r\n"
 #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM "\r\n"
 #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_END "\r\n\r\n"
 #define QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "13"

@@ -123,8 +152,46 @@ enum {
     QIO_CHANNEL_WEBSOCK_OPCODE_PONG = 0xA
 };
 
+static void qio_channel_websock_handshake_send_res(QIOChannelWebsock *ioc,
+                                                   const char *resmsg,
+                                                   ...)
+{
+    va_list vargs;
+    char *response;
+    size_t responselen;
+
+    va_start(vargs, resmsg);
+    response = g_strdup_vprintf(resmsg, vargs);
+    responselen = strlen(response);
+    buffer_reserve(&ioc->encoutput, responselen);
+    buffer_append(&ioc->encoutput, response, responselen);
+    va_end(vargs);
+}
+
+static gchar *qio_channel_websock_date_str(void)
+{
+    struct tm tm;
+    time_t now = time(NULL);
+    char datebuf[128];
+
+    gmtime_r(&now, &tm);
+
+    strftime(datebuf, sizeof(datebuf), "%a, %d %b %Y %H:%M:%S GMT", &tm);
+
+    return g_strdup(datebuf);
+}
+
+static void qio_channel_websock_handshake_send_res_err(QIOChannelWebsock *ioc,
+                                                       const char *resdata)
+{
+    char *date = qio_channel_websock_date_str();
+    qio_channel_websock_handshake_send_res(ioc, resdata, date);
+    g_free(date);
+}
+
 static size_t
-qio_channel_websock_extract_headers(char *buffer,
+qio_channel_websock_extract_headers(QIOChannelWebsock *ioc,
+                                    char *buffer,
                                     QIOChannelWebsockHTTPHeader *hdrs,
                                     size_t nhdrsalloc,
                                     Error **errp)

@@ -145,7 +212,7 @@ qio_channel_websock_extract_headers(char *buffer,
     nl = strstr(buffer, QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM);
     if (!nl) {
         error_setg(errp, "Missing HTTP header delimiter");
-        return 0;
+        goto bad_request;
     }
     *nl = '\0';
 

@@ -158,18 +225,20 @@ qio_channel_websock_extract_headers(char *buffer,
 
     if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_METHOD)) {
         error_setg(errp, "Unsupported HTTP method %s", buffer);
-        return 0;
+        goto bad_request;
     }
 
     buffer = tmp + 1;
     tmp = strchr(buffer, ' ');
     if (!tmp) {
         error_setg(errp, "Missing HTTP version delimiter");
-        return 0;
+        goto bad_request;
     }
     *tmp = '\0';
 
     if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_PATH)) {
+        qio_channel_websock_handshake_send_res_err(
+            ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_NOT_FOUND);
         error_setg(errp, "Unexpected HTTP path %s", buffer);
         return 0;
     }

@@ -178,7 +247,7 @@ qio_channel_websock_extract_headers(char *buffer,
 
     if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_VERSION)) {
         error_setg(errp, "Unsupported HTTP version %s", buffer);
-        return 0;
+        goto bad_request;
     }
 
     buffer = nl + strlen(QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM);

@@ -203,7 +272,7 @@ qio_channel_websock_extract_headers(char *buffer,
         sep = strchr(buffer, ':');
         if (!sep) {
             error_setg(errp, "Malformed HTTP header");
-            return 0;
+            goto bad_request;
         }
         *sep = '\0';
         sep++;

@@ -213,7 +282,7 @@ qio_channel_websock_extract_headers(char *buffer,
 
         if (nhdrs >= nhdrsalloc) {
             error_setg(errp, "Too many HTTP headers");
-            return 0;
+            goto bad_request;
         }
 
         hdr = &hdrs[nhdrs++];

@@ -231,6 +300,11 @@ qio_channel_websock_extract_headers(char *buffer,
     } while (nl != NULL);
 
     return nhdrs;
+
+ bad_request:
+    qio_channel_websock_handshake_send_res_err(
+        ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST);
+    return 0;
 }
 
 static const char *

@@ -250,14 +324,14 @@ qio_channel_websock_find_header(QIOChannelWebsockHTTPHeader *hdrs,
 }
 
 
-static int qio_channel_websock_handshake_send_response(QIOChannelWebsock *ioc,
-                                                       const char *key,
-                                                       Error **errp)
+static void qio_channel_websock_handshake_send_res_ok(QIOChannelWebsock *ioc,
+                                                      const char *key,
+                                                      Error **errp)
 {
     char combined_key[QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN +
                       QIO_CHANNEL_WEBSOCK_GUID_LEN + 1];
-    char *accept = NULL, *response = NULL;
-    size_t responselen;
+    char *accept = NULL;
+    char *date = qio_channel_websock_date_str();
 
     g_strlcpy(combined_key, key, QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN + 1);
     g_strlcat(combined_key, QIO_CHANNEL_WEBSOCK_GUID,

@@ -271,105 +345,108 @@ static int qio_channel_websock_handshake_send_response(QIOChannelWebsock *ioc,
                             QIO_CHANNEL_WEBSOCK_GUID_LEN,
                             &accept,
                             errp) < 0) {
-        return -1;
+        qio_channel_websock_handshake_send_res_err(
+            ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_SERVER_ERR);
+        return;
     }
 
-    response = g_strdup_printf(QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE, accept);
-    responselen = strlen(response);
-    buffer_reserve(&ioc->encoutput, responselen);
-    buffer_append(&ioc->encoutput, response, responselen);
+    qio_channel_websock_handshake_send_res(
+        ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_OK, date, accept);
 
+    g_free(date);
     g_free(accept);
-    g_free(response);
-
-    return 0;
 }
 
-static int qio_channel_websock_handshake_process(QIOChannelWebsock *ioc,
-                                                 char *buffer,
-                                                 Error **errp)
+static void qio_channel_websock_handshake_process(QIOChannelWebsock *ioc,
+                                                  char *buffer,
+                                                  Error **errp)
 {
     QIOChannelWebsockHTTPHeader hdrs[32];
     size_t nhdrs = G_N_ELEMENTS(hdrs);
     const char *protocols = NULL, *version = NULL, *key = NULL,
         *host = NULL, *connection = NULL, *upgrade = NULL;
 
-    nhdrs = qio_channel_websock_extract_headers(buffer, hdrs, nhdrs, errp);
+    nhdrs = qio_channel_websock_extract_headers(ioc, buffer, hdrs, nhdrs, errp);
     if (!nhdrs) {
-        return -1;
+        return;
     }
 
     protocols = qio_channel_websock_find_header(
         hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_PROTOCOL);
     if (!protocols) {
         error_setg(errp, "Missing websocket protocol header data");
-        return -1;
+        goto bad_request;
     }
 
     version = qio_channel_websock_find_header(
         hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_VERSION);
     if (!version) {
         error_setg(errp, "Missing websocket version header data");
-        return -1;
+        goto bad_request;
     }
 
     key = qio_channel_websock_find_header(
         hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_KEY);
     if (!key) {
         error_setg(errp, "Missing websocket key header data");
-        return -1;
+        goto bad_request;
     }
 
     host = qio_channel_websock_find_header(
         hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_HOST);
     if (!host) {
         error_setg(errp, "Missing websocket host header data");
-        return -1;
+        goto bad_request;
     }
 
     connection = qio_channel_websock_find_header(
         hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_CONNECTION);
     if (!connection) {
         error_setg(errp, "Missing websocket connection header data");
-        return -1;
+        goto bad_request;
     }
 
     upgrade = qio_channel_websock_find_header(
         hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_UPGRADE);
     if (!upgrade) {
         error_setg(errp, "Missing websocket upgrade header data");
-        return -1;
+        goto bad_request;
     }
 
     if (!g_strrstr(protocols, QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY)) {
         error_setg(errp, "No '%s' protocol is supported by client '%s'",
                    QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY, protocols);
-        return -1;
+        goto bad_request;
     }
 
     if (!g_str_equal(version, QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION)) {
         error_setg(errp, "Version '%s' is not supported by client '%s'",
                    QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION, version);
-        return -1;
+        goto bad_request;
     }
 
     if (strlen(key) != QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN) {
         error_setg(errp, "Key length '%zu' was not as expected '%d'",
                    strlen(key), QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN);
-        return -1;
+        goto bad_request;
     }
 
     if (!g_strrstr(connection, QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE)) {
         error_setg(errp, "No connection upgrade requested '%s'", connection);
-        return -1;
+        goto bad_request;
     }
 
     if (!g_str_equal(upgrade, QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET)) {
         error_setg(errp, "Incorrect upgrade method '%s'", upgrade);
-        return -1;
+        goto bad_request;
     }
 
-    return qio_channel_websock_handshake_send_response(ioc, key, errp);
+    qio_channel_websock_handshake_send_res_ok(ioc, key, errp);
+    return;
+
+ bad_request:
+    qio_channel_websock_handshake_send_res_err(
+        ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST);
 }
 
 static int qio_channel_websock_handshake_read(QIOChannelWebsock *ioc,

@@ -393,20 +470,20 @@ static int qio_channel_websock_handshake_read(QIOChannelWebsock *ioc,
                                  QIO_CHANNEL_WEBSOCK_HANDSHAKE_END);
     if (!handshake_end) {
         if (ioc->encinput.offset >= 4096) {
+            qio_channel_websock_handshake_send_res_err(
+                ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_TOO_LARGE);
             error_setg(errp,
                        "End of headers not found in first 4096 bytes");
-            return -1;
+            return 1;
         } else {
             return 0;
         }
     }
     *handshake_end = '\0';
 
-    if (qio_channel_websock_handshake_process(ioc,
-                                              (char *)ioc->encinput.buffer,
-                                              errp) < 0) {
-        return -1;
-    }
+    qio_channel_websock_handshake_process(ioc,
+                                          (char *)ioc->encinput.buffer,
+                                          errp);
 
     buffer_advance(&ioc->encinput,
                    handshake_end - (char *)ioc->encinput.buffer +

@@ -438,8 +515,15 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc,
 
     buffer_advance(&wioc->encoutput, ret);
     if (wioc->encoutput.offset == 0) {
-        trace_qio_channel_websock_handshake_complete(ioc);
-        qio_task_complete(task);
+        if (wioc->io_err) {
+            trace_qio_channel_websock_handshake_fail(ioc);
+            qio_task_set_error(task, wioc->io_err);
+            wioc->io_err = NULL;
+            qio_task_complete(task);
+        } else {
+            trace_qio_channel_websock_handshake_complete(ioc);
+            qio_task_complete(task);
+        }
         return FALSE;
     }
     trace_qio_channel_websock_handshake_pending(ioc, G_IO_OUT);

@@ -458,6 +542,11 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc,
 
     ret = qio_channel_websock_handshake_read(wioc, &err);
     if (ret < 0) {
+        /*
+         * We only take this path on a fatal I/O error reading from
+         * client connection, as most of the time we have an
+         * HTTP 4xx err response to send instead
+         */
         trace_qio_channel_websock_handshake_fail(ioc);
         qio_task_set_error(task, err);
         qio_task_complete(task);

@@ -469,6 +558,10 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc,
         return TRUE;
     }
 
+    if (err) {
+        error_propagate(&wioc->io_err, err);
+    }
+
     trace_qio_channel_websock_handshake_reply(ioc);
     qio_channel_add_watch(
         wioc->master,

index f5fac5b422..6ddcec1549 100644
@@ -507,7 +507,7 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc,
                             &err);
 
     if (ret < 0) {
-        trace_qio_channel_websock_handshake_fail(ioc);
+        trace_qio_channel_websock_handshake_fail(ioc, error_get_pretty(err));
         qio_task_set_error(task, err);
         qio_task_complete(task);
         return FALSE;

@@ -516,7 +516,8 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc,
     buffer_advance(&wioc->encoutput, ret);
     if (wioc->encoutput.offset == 0) {
         if (wioc->io_err) {
-            trace_qio_channel_websock_handshake_fail(ioc);
+            trace_qio_channel_websock_handshake_fail(
+                ioc, error_get_pretty(wioc->io_err));
             qio_task_set_error(task, wioc->io_err);
             wioc->io_err = NULL;
             qio_task_complete(task);

@@ -547,7 +548,7 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc,
          * client connection, as most of the time we have an
          * HTTP 4xx err response to send instead
          */
-        trace_qio_channel_websock_handshake_fail(ioc);
+        trace_qio_channel_websock_handshake_fail(ioc, error_get_pretty(err));
         qio_task_set_error(task, err);
         qio_task_complete(task);
         return FALSE;

index 6ddcec1549..2258557a21 100644
@@ -431,12 +431,12 @@ static void qio_channel_websock_handshake_process(QIOChannelWebsock *ioc,
         goto bad_request;
     }
 
-    if (!g_strrstr(connection, QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE)) {
+    if (strcasecmp(connection, QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE) != 0) {
         error_setg(errp, "No connection upgrade requested '%s'", connection);
         goto bad_request;
     }
 
-    if (!g_str_equal(upgrade, QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET)) {
+    if (strcasecmp(upgrade, QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET) != 0) {
         error_setg(errp, "Incorrect upgrade method '%s'", upgrade);
         goto bad_request;
     }