utf8 check compatible with extensions

Signed-off-by: Andy Green <andy.green@linaro.org>

diff --git a/lib/client-parser.c b/lib/client-parser.c
index ec35e13..9350281 100644 (file)
--- a/lib/client-parser.c
+++ b/lib/client-parser.c
@@ -291,67 +291,6 @@ int lws_client_rx_sm(struct lws *wsi, unsigned char c)
                        c ^= wsi->u.ws.mask_nonce[
                                            (wsi->u.ws.frame_mask_index++) & 3];
 
-               /* if we skipped the 2-byte code at the start, UTF-8 after */
-               if (wsi->u.ws.opcode == LWSWSOPC_CLOSE &&
-                   wsi->u.ws.rx_user_buffer_head == 2)
-                       wsi->u.ws.check_utf8 = !!(wsi->context->options &
-                                              LWS_SERVER_OPTION_VALIDATE_UTF8);
-
-               if (wsi->u.ws.check_utf8 && !wsi->u.ws.defeat_check_utf8) {
-                       static const unsigned char e0f4[] = {
-                               0xa0 | ((2 - 1) << 2) | 1, /* e0 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e1 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e2 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e3 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e4 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e5 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e6 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e7 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e8 */
-                               0x80 | ((4 - 1) << 2) | 1, /* e9 */
-                               0x80 | ((4 - 1) << 2) | 1, /* ea */
-                               0x80 | ((4 - 1) << 2) | 1, /* eb */
-                               0x80 | ((4 - 1) << 2) | 1, /* ec */
-                               0x80 | ((2 - 1) << 2) | 1, /* ed */
-                               0x80 | ((4 - 1) << 2) | 1, /* ee */
-                               0x80 | ((4 - 1) << 2) | 1, /* ef */
-                               0x90 | ((3 - 1) << 2) | 2, /* f0 */
-                               0x80 | ((4 - 1) << 2) | 2, /* f1 */
-                               0x80 | ((4 - 1) << 2) | 2, /* f2 */
-                               0x80 | ((4 - 1) << 2) | 2, /* f3 */
-                               0x80 | ((1 - 1) << 2) | 2, /* f4 */
-
-                               0,                         /* s0 */
-                               0x80 | ((4 - 1) << 2) | 0, /* s2 */
-                               0x80 | ((4 - 1) << 2) | 1, /* s3 */
-                       };
-
-                       if (!wsi->u.ws.utf8) {
-                               if (c >= 0x80) {
-                                       if (c < 0xc2 || c > 0xf4)
-                                               goto utf8_fail;
-                                       if (c < 0xe0)
-                                               wsi->u.ws.utf8 = 0x80 |
-                                                                ((4 - 1) << 2);
-                                       else
-                                               wsi->u.ws.utf8 = e0f4[c - 0xe0];
-                               }
-                       } else {
-                               if (c < (wsi->u.ws.utf8 & 0xf0) ||
-                                   c >= (wsi->u.ws.utf8 & 0xf0) + 0x10 +
-                                        ((wsi->u.ws.utf8 << 2) & 0x30))
-                                       goto utf8_fail;
-                               wsi->u.ws.utf8 = e0f4[21 + (wsi->u.ws.utf8 & 3)];
-                       }
-
-                       /* we are ending partway through utf-8 character? */
-                       if (wsi->u.ws.final && wsi->u.ws.rx_packet_length == 1 &&
-                           wsi->u.ws.utf8) {
-utf8_fail:                     lwsl_info("utf8 error\n");
-                               return -1;
-                       }
-               }
-
                wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
                                         (wsi->u.ws.rx_user_buffer_head++)] = c;
 
@@ -386,6 +325,14 @@ spill:
 
                switch (wsi->u.ws.opcode) {
                case LWSWSOPC_CLOSE:
+                       pp = (unsigned char *)&wsi->u.ws.rx_user_buffer[
+                                               LWS_SEND_BUFFER_PRE_PADDING];
+                       if (wsi->context->options & LWS_SERVER_OPTION_VALIDATE_UTF8 &&
+                           wsi->u.ws.rx_user_buffer_head > 2 &&
+                           lws_check_utf8(&wsi->u.ws.utf8, pp + 2,
+                                          wsi->u.ws.rx_user_buffer_head - 2))
+                               goto utf8_fail;
+
                        /* is this an acknowledgement of our close? */
                        if (wsi->state == LWSS_AWAITING_CLOSE_ACK) {
                                /*
@@ -395,8 +342,7 @@ spill:
                                lwsl_parser("seen server's close ack\n");
                                return -1;
                        }
-                       pp = (unsigned char *)&wsi->u.ws.rx_user_buffer[
-                                               LWS_SEND_BUFFER_PRE_PADDING];
+
                        lwsl_parser("client sees server close len = %d\n",
                                                 wsi->u.ws.rx_user_buffer_head);
                        if (wsi->u.ws.rx_user_buffer_head >= 2) {
@@ -526,11 +472,25 @@ ping_drop:
                                               &eff_buf, 0) < 0) /* fail */
                        return -1;
 
+               if (wsi->u.ws.check_utf8 && !wsi->u.ws.defeat_check_utf8) {
+                       if (lws_check_utf8(&wsi->u.ws.utf8,
+                                          (unsigned char *)eff_buf.token,
+                                          eff_buf.token_len))
+                               goto utf8_fail;
+
+                       /* we are ending partway through utf-8 character? */
+                       if (wsi->u.ws.final && wsi->u.ws.utf8) {
+utf8_fail:                     lwsl_info("utf8 error\n");
+                               return -1;
+                       }
+               }
+
                if (eff_buf.token_len < 0 &&
                    callback_action != LWS_CALLBACK_CLIENT_RECEIVE_PONG)
                        goto already_done;
 
-               eff_buf.token[eff_buf.token_len] = '\0';
+               if (eff_buf.token)
+                       eff_buf.token[eff_buf.token_len] = '\0';
 
                if (!wsi->protocol->callback)
                        goto already_done;

diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index 82f317a..082bd43 100644 (file)
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -1009,3 +1009,60 @@ _lws_rx_flow_control(struct lws *wsi)
 
        return 0;
 }
+
+LWS_EXTERN int
+lws_check_utf8(unsigned char *state, unsigned char *buf, size_t len)
+{
+       static const unsigned char e0f4[] = {
+               0xa0 | ((2 - 1) << 2) | 1, /* e0 */
+               0x80 | ((4 - 1) << 2) | 1, /* e1 */
+               0x80 | ((4 - 1) << 2) | 1, /* e2 */
+               0x80 | ((4 - 1) << 2) | 1, /* e3 */
+               0x80 | ((4 - 1) << 2) | 1, /* e4 */
+               0x80 | ((4 - 1) << 2) | 1, /* e5 */
+               0x80 | ((4 - 1) << 2) | 1, /* e6 */
+               0x80 | ((4 - 1) << 2) | 1, /* e7 */
+               0x80 | ((4 - 1) << 2) | 1, /* e8 */
+               0x80 | ((4 - 1) << 2) | 1, /* e9 */
+               0x80 | ((4 - 1) << 2) | 1, /* ea */
+               0x80 | ((4 - 1) << 2) | 1, /* eb */
+               0x80 | ((4 - 1) << 2) | 1, /* ec */
+               0x80 | ((2 - 1) << 2) | 1, /* ed */
+               0x80 | ((4 - 1) << 2) | 1, /* ee */
+               0x80 | ((4 - 1) << 2) | 1, /* ef */
+               0x90 | ((3 - 1) << 2) | 2, /* f0 */
+               0x80 | ((4 - 1) << 2) | 2, /* f1 */
+               0x80 | ((4 - 1) << 2) | 2, /* f2 */
+               0x80 | ((4 - 1) << 2) | 2, /* f3 */
+               0x80 | ((1 - 1) << 2) | 2, /* f4 */
+
+               0,                         /* s0 */
+               0x80 | ((4 - 1) << 2) | 0, /* s2 */
+               0x80 | ((4 - 1) << 2) | 1, /* s3 */
+       };
+       unsigned char s = *state;
+
+       while (len--) {
+               unsigned char c = *buf++;
+
+               if (!s) {
+                       if (c >= 0x80) {
+                               if (c < 0xc2 || c > 0xf4)
+                                       return 1;
+                               if (c < 0xe0)
+                                       s = 0x80 | ((4 - 1) << 2);
+                               else
+                                       s = e0f4[c - 0xe0];
+                       }
+               } else {
+                       if (c < (s & 0xf0) ||
+                           c >= (s & 0xf0) + 0x10 + ((s << 2) & 0x30))
+                               return 1;
+                       s = e0f4[21 + (s & 3)];
+               }
+       }
+
+       *state = s;
+
+       return 0;
+}

diff --git a/lib/private-libwebsockets.h b/lib/private-libwebsockets.h
index 3ef7a52..b443daf 100644 (file)
--- a/lib/private-libwebsockets.h
+++ b/lib/private-libwebsockets.h
@@ -1312,6 +1312,9 @@ time_in_microseconds(void);
 LWS_EXTERN const char *
 lws_plat_inet_ntop(int af, const void *src, char *dst, int cnt);
 
+LWS_EXTERN int
+lws_check_utf8(unsigned char *state, unsigned char *buf, size_t len);
+
 #ifdef __cplusplus
 };
 #endif