From e45ef6a0dd5d94568c0e7c8ef652069ac6e49fe0 Mon Sep 17 00:00:00 2001
From: Grant McEwan <grant.mcewan@alliedtelesis.co.nz>
Date: Fri, 25 Jun 2021 15:24:20 +1200
Subject: [PATCH] DCP identify return false if it hasn't handled a request

The function pf_dcp_identify_req, would return 1 even if the request
wasn't handled by it, this would lead to replies to invalid requests
sent to the device. Fixing this so that it only returns 1 if the
request being made passes the necessary checks.

Fixed the invalid ident_req array in the gtests, filled with proper
station name, and tests now check if the station name, dcp data length
and dcp block length are correct for packets.
---
 src/common/pf_dcp.c   | 14 +++++++++++++-
 src/device/pf_cmina.c |  2 +-
 test/test_dcp.cpp     |  2 +-
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/common/pf_dcp.c b/src/common/pf_dcp.c
index 1cd24465..4540751c 100644
--- a/src/common/pf_dcp.c
+++ b/src/common/pf_dcp.c
@@ -1526,8 +1526,15 @@ static int pf_dcp_identify_req (
       src_pos += sizeof (*p_src_block_hdr); /* Point to the block value */
 
       src_block_len = ntohs (p_src_block_hdr->block_length);
+      /* Check if we have a valid dcp data length */
+      if (!(src_dcplen >= (src_pos + src_block_len)))
+      {
+          ret = -1;
+      }
+      else {
+          match = true; /* So far so good */
+      }
 
-      match = true; /* So far so good */
       while ((ret == 0) && (first || (filter && match)) &&
              (src_dcplen >= (src_pos + src_block_len)) &&
              (dst_pos < PF_FRAME_BUFFER_SIZE))
@@ -1948,6 +1955,11 @@ static int pf_dcp_identify_req (
          __LINE__);
    }
 
+   if ((ret <= 0) && (match == false))
+   {
+       return ret; /* Not handled, not matched or something went wrong */
+   }
+
    if (p_buf != NULL)
    {
       pnal_buf_free (p_buf);
diff --git a/src/device/pf_cmina.c b/src/device/pf_cmina.c
index 62092cd0..d764d3b0 100644
--- a/src/device/pf_cmina.c
+++ b/src/device/pf_cmina.c
@@ -1129,7 +1129,7 @@ int pf_cmina_dcp_get_req (
          *pp_value = (uint8_t *)net->cmina_current_dcp_ase.product_name;
          break;
       case PF_DCP_SUB_DEV_PROP_NAME:
-         *p_value_length = sizeof (net->cmina_current_dcp_ase.station_name);
+         *p_value_length = strlen(net->cmina_current_dcp_ase.station_name);
          *pp_value = (uint8_t *)net->cmina_current_dcp_ase.station_name;
          break;
       case PF_DCP_SUB_DEV_PROP_ID:
diff --git a/test/test_dcp.cpp b/test/test_dcp.cpp
index 90138546..52d647f5 100644
--- a/test/test_dcp.cpp
+++ b/test/test_dcp.cpp
@@ -54,7 +54,7 @@ static uint8_t get_name_req[] = {
 
 static uint8_t ident_req[] = {
    0x01, 0x0e, 0xcf, 0x00, 0x00, 0x00, 0xc8, 0x5b, 0x76, 0xe6, 0x89, 0xdf,
-   0x88, 0x92, 0xfe, 0xfe, 0x05, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01,
+   0x88, 0x92, 0xfe, 0xfe, 0x05, 0x00, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00,
    0x00, 0x10, 0x02, 0x02, 0x00, 0x0c, 0x72, 0x74, 0x2d, 0x6c, 0x61, 0x62,
    0x73, 0x2d, 0x64, 0x65, 0x6d, 0x6f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};