[src/trunk]: src/sys/arch/usermode/usermode Implement safe_recv() in analog t...

[reinoud <reinoud%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ba87db187a7d
branches:  trunk
changeset: 772367:ba87db187a7d
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Sat Dec 31 12:38:56 2011 +0000

description:
Implement safe_recv() in analog to save_send() to make sure we don't miss
bytes along and mess up the protocol.

diffstat:

 sys/arch/usermode/usermode/thunk.c |  114 +++++++++++++++++++++++++-----------
 1 files changed, 78 insertions(+), 36 deletions(-)

diffs (219 lines):

diff -r 12976d204bbe -r ba87db187a7d sys/arch/usermode/usermode/thunk.c
--- a/sys/arch/usermode/usermode/thunk.c        Sat Dec 31 08:34:49 2011 +0000
+++ b/sys/arch/usermode/usermode/thunk.c        Sat Dec 31 12:38:56 2011 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: thunk.c,v 1.68 2011/12/30 21:14:58 reinoud Exp $ */
+/* $NetBSD: thunk.c,v 1.69 2011/12/31 12:38:56 reinoud Exp $ */
 
 /*-
  * Copyright (c) 2011 Jared D. McNeill <jmcneill%invisible.ca@localhost>
@@ -28,7 +28,7 @@
 
 #include <sys/cdefs.h>
 #ifdef __NetBSD__
-__RCSID("$NetBSD: thunk.c,v 1.68 2011/12/30 21:14:58 reinoud Exp $");
+__RCSID("$NetBSD: thunk.c,v 1.69 2011/12/31 12:38:56 reinoud Exp $");
 #endif
 
 #include <sys/types.h>
@@ -897,7 +897,7 @@
        return 0;
 }
 
-static int
+static ssize_t
 safe_send(int s, const void *msg, size_t len)
 {
        const uint8_t *p;
@@ -916,6 +916,25 @@
        return 0;
 }
 
+static ssize_t
+safe_recv(int s, void *buf, size_t len)
+{
+       uint8_t *p;
+       int recv_len;
+
+       p = buf;
+       while (len) {
+               assert(len >= 0);
+               recv_len = recv(s, p, len, MSG_NOSIGNAL);
+               if (recv_len < 0) 
+                       return -1;
+       
+               p   += recv_len;
+               len -= recv_len;
+       }
+       return 0;
+}
+
 static int
 thunk_rfb_server_init(thunk_rfb_t *rfb)
 {
@@ -960,11 +979,9 @@
 
        /* receive client protocol version */
        do {
-               len = recv(rfb->clientfd, &dummy, sizeof(dummy), MSG_NOSIGNAL);
+               len = safe_recv(rfb->clientfd, &dummy, sizeof(dummy));
                if (len < 0)
                        return errno;
-               if (len == 0)
-                       return EIO;
        } while (dummy != '\n');
 
        /* send security capabilities */
@@ -974,9 +991,8 @@
                return errno;
 
        /* receive client init message */
-       len = recv(rfb->clientfd, &shared_flag, sizeof(shared_flag),
-               MSG_NOSIGNAL);
-       if (len <= 0)
+       len = safe_recv(rfb->clientfd, &shared_flag, sizeof(shared_flag));
+       if (len < 0)
                return errno;
 
        /* send server init message */
@@ -1168,11 +1184,11 @@
        if (rfb->clientfd == -1)
                return -1;
 
-       thunk_rfb_send_pending(rfb);
-
        if (event == NULL)
                return 0;
 
+       thunk_rfb_send_pending(rfb);
+
        if (rfb->schedule_bell) {
                uint8_t msg_type = 2;   /* bell */
                safe_send(rfb->clientfd, &msg_type, sizeof(msg_type));
@@ -1180,16 +1196,14 @@
        }
 
        error = ioctl(rfb->clientfd, FIONREAD, &len);
-       if (error) {
-               //printf("rfb: FIONREAD failed: %s\n", strerror(errno));
-               close(rfb->clientfd);
-               rfb->clientfd = -1;
-               return -1;
-       }
+       if (error)
+               goto discon;
        if (len == 0)
                return 0;
 
-       recv(rfb->clientfd, &ch, sizeof(ch), MSG_NOSIGNAL);
+       len = safe_recv(rfb->clientfd, &ch, sizeof(ch));
+       if (len < 0)
+               goto discon;
 
        event->message_type = ch;
        switch (ch) {
@@ -1197,25 +1211,39 @@
                msg_len = sizeof(set_pixel_format);
                break;
        case THUNK_RFB_SET_ENCODINGS:
-               recv(rfb->clientfd, set_encodings, sizeof(set_encodings),
-                   MSG_NOSIGNAL);
+               len = safe_recv(rfb->clientfd,
+                       set_encodings, sizeof(set_encodings));
+               if (len < 0)
+                       goto discon;
                msg_len = 4 * ntohs(*(uint16_t *)&set_encodings[1]);
                break;
        case THUNK_RFB_FRAMEBUFFER_UPDATE_REQUEST:
-               recv(rfb->clientfd, framebuffer_update_request,
-                       sizeof(framebuffer_update_request), MSG_NOSIGNAL);
-#if 0
+               len = safe_recv(rfb->clientfd,
+                       framebuffer_update_request,
+                       sizeof(framebuffer_update_request));
+               if (len < 0)
+                       goto discon;
+#ifdef RFB_DEBUG
+               fprintf(stdout, "framebuffer update request: ");
+               fprintf(stdout, "[%d, %d] + [%d, %d] %s\n",
+                       framebuffer_update_request[1],
+                       framebuffer_update_request[2],
+                       framebuffer_update_request[3],
+                       framebuffer_update_request[4],
+                       framebuffer_update_request[0]?"Incrmental":"Complete");
+#endif
+                       
                if (framebuffer_update_request[0] == 0) {
-fprintf(stdout, "complete update request\n");
                        /* complete redraw request -> buffer full */
-                       rfb->nupdates = __arraycount(rfb->update);
+                       rfb->nupdates = __arraycount(rfb->update) + 1;
                }
-               thunk_rfb_send_pending(rfb);
-#endif
+//             thunk_rfb_send_pending(rfb);
                msg_len = 0;
                break;
        case THUNK_RFB_KEY_EVENT:
-               recv(rfb->clientfd, key_event, sizeof(key_event), MSG_NOSIGNAL);
+               len = safe_recv(rfb->clientfd, key_event, sizeof(key_event));
+               if (len < 0)
+                       goto discon;
                event->data.key_event.down_flag = key_event[0];
                event->data.key_event.keysym =
                    ntohl(*(uint32_t *)&key_event[3]);
@@ -1227,8 +1255,10 @@
                msg_len = 0;
                break;
        case THUNK_RFB_POINTER_EVENT:
-               recv(rfb->clientfd, pointer_event, sizeof(pointer_event),
-                   MSG_NOSIGNAL);
+               len = safe_recv(rfb->clientfd,
+                       pointer_event, sizeof(pointer_event));
+               if (len < 0)
+                       goto discon;
                event->data.pointer_event.button_mask = pointer_event[0];
                event->data.pointer_event.absx =
                    ntohs(*(uint16_t *)&pointer_event[1]);
@@ -1243,23 +1273,35 @@
                msg_len = 0;
                break;
        case THUNK_RFB_CLIENT_CUT_TEXT:
-               recv(rfb->clientfd, client_cut_text, sizeof(client_cut_text),
-                   MSG_NOSIGNAL);
+               len = safe_recv(rfb->clientfd,
+                       client_cut_text, sizeof(client_cut_text));
+               if (len < 0)
+                       goto discon;
                msg_len = ntohl(*(uint32_t *)&client_cut_text[3]);
                break;
        default:
                fprintf(stdout, "rfb: unknown message type %d\n", ch);
-               close(rfb->clientfd);
-               rfb->clientfd = -1;
-               return -1;
+               goto discon;
        }
 
+       if (len < 0)
+               goto discon;
+
        /* discard any remaining bytes */
        while (msg_len-- > 0) {
-               recv(rfb->clientfd, &ch, sizeof(ch), MSG_NOSIGNAL);
+               len = safe_recv(rfb->clientfd, &ch, sizeof(ch));
+               if (len < 0)
+                       goto discon;
        }
 
        return 1;
+
+discon:
+       //printf("rfb: safe_recv failed: %s\n", strerror(errno));
+       close(rfb->clientfd);
+       rfb->clientfd = -1;
+
+       return -1;
 }
 
 void