From d32953c405404442cbf6b29dd83dfe8dd1a7713a Mon Sep 17 00:00:00 2001
From: matt335672 <30179339+matt335672@users.noreply.github.com>
Date: Thu, 2 Sep 2021 17:08:53 +0100
Subject: [PATCH] Parse DEVICE_ANNOUNCE header correctly

---
 common/parse.h            |  2 ++
 sesman/chansrv/devredir.c | 55 +++++++++++++++++++++------------------
 2 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/common/parse.h b/common/parse.h
index 500d57d7..b27bb0c9 100644
--- a/common/parse.h
+++ b/common/parse.h
@@ -498,6 +498,8 @@ parser_stream_overflow_check(const struct stream *s, int n, int is_out,
  *****************************************************************************/
 #define xstream_free(_s) free_stream(_s)
 
+#define xstream_skip_u8(_s, _n)       in_uint8s(_s, _n)
+
 #define xstream_rd_u8(_s, _var)       in_uint8(_s, _var)
 #define xstream_rd_u16_le(_s, _var)   in_uint16_le(_s, _var)
 #define xstream_rd_u32_le(_s, _var)   in_uint32_le(_s, _var)
diff --git a/sesman/chansrv/devredir.c b/sesman/chansrv/devredir.c
index d5f7313a..b50c6049 100644
--- a/sesman/chansrv/devredir.c
+++ b/sesman/chansrv/devredir.c
@@ -814,18 +814,24 @@ devredir_proc_client_devlist_announce_req(struct stream *s)
         /* Assume this device isn't supported by us */
         response_status = STATUS_NOT_SUPPORTED;
 
+        /* Read the device data length from the stream */
+        xstream_rd_u32_le(s, device_data_len);
+
         switch (device_type)
         {
             case RDPDR_DTYP_FILESYSTEM:
                 /* get device data len */
-                xstream_rd_u32_le(s, device_data_len);
                 if (device_data_len)
                 {
                     xstream_rd_string(g_full_name_for_filesystem, s,
                                       device_data_len);
                 }
 
-                LOG_DEVEL(LOG_LEVEL_DEBUG, "device_type=FILE_SYSTEM device_id=0x%x dosname=%s "
+                LOG(LOG_LEVEL_INFO, "detected remote drive %s",
+                    preferred_dos_name);
+
+                LOG_DEVEL(LOG_LEVEL_DEBUG,
+                          "device_type=FILE_SYSTEM device_id=0x%x dosname=%s "
                           "device_data_len=%d full_name=%s", g_device_id,
                           preferred_dos_name,
                           device_data_len, g_full_name_for_filesystem);
@@ -838,9 +844,13 @@ devredir_proc_client_devlist_announce_req(struct stream *s)
                 break;
 
             case RDPDR_DTYP_SMARTCARD:
-                /* for smart cards, device data len always 0 */
+                xstream_skip_u8(s, device_data_len);
 
-                LOG_DEVEL(LOG_LEVEL_DEBUG, "device_type=SMARTCARD device_id=0x%x dosname=%s",
+                LOG(LOG_LEVEL_INFO, "Detected remote smartcard '%s'",
+                    preferred_dos_name);
+
+                LOG_DEVEL(LOG_LEVEL_DEBUG,
+                          "device_type=SMARTCARD device_id=0x%x dosname=%s",
                           g_device_id, preferred_dos_name);
 
                 response_status = STATUS_SUCCESS;
@@ -848,29 +858,24 @@ devredir_proc_client_devlist_announce_req(struct stream *s)
                 scard_device_announce(g_device_id);
                 break;
 
-            case RDPDR_DTYP_SERIAL:
-                LOG_DEVEL(LOG_LEVEL_DEBUG,
-                          "device_type=SERIAL device_id=0x%x dosname=%s",
-                          g_device_id, preferred_dos_name);
-                break;
-
-            case RDPDR_DTYP_PARALLEL:
-                LOG_DEVEL(LOG_LEVEL_DEBUG,
-                          "device_type=PARALLEL device_id=0x%x dosname=%s",
-                          g_device_id, preferred_dos_name);
-                break;
-
-            case RDPDR_DTYP_PRINT:
-                LOG_DEVEL(LOG_LEVEL_DEBUG,
-                          "device_type=PRINT device_id=0x%x dosname=%s",
-                          g_device_id, preferred_dos_name);
-                break;
-
             default:
+            {
+                /* All other devices are unsupported */
+                const char *description =
+                    (device_type == RDPDR_DTYP_SERIAL) ? "serial port" :
+                    (device_type == RDPDR_DTYP_PARALLEL) ? "parallel port" :
+                    (device_type == RDPDR_DTYP_PRINT) ?  "printer" :
+                    /* default */ "unknown device";
+
+                xstream_skip_u8(s, device_data_len);
+                LOG(LOG_LEVEL_INFO, "Remote %s '%s' is not supported"
+                    " and will be ignored",
+                    description, preferred_dos_name);
                 LOG_DEVEL(LOG_LEVEL_DEBUG,
-                          "device_type=UNKNOWN device_id=0x%x dosname=%s",
-                          g_device_id, preferred_dos_name);
-                break;
+                          "description=%s dosname=%s device_id=0x%x",
+                          description, preferred_dos_name, g_device_id);
+            }
+            break;
         }
 
         /* Tell the client wheth or not we're supporting this one */