From: Guy Harris <gharris@sonic.net>
Date: Tue, 10 Jan 2023 08:24:10 +0000 (-0800)
Subject: NPF: fix build, update comments.
X-Git-Tag: libpcap-1.10.3~3
X-Git-Url: https://git.tcpdump.org/libpcap/commitdiff_plain/1962e7e8d12a8a2b434257ad965879934970d709

NPF: fix build, update comments.

The MS Surface Pro's mobile broadband driver appears to be returning
NDIS_STATUS_NOT_SUPPORTED for all attempts to set the hardware filter,
whether promiscuous mode is on or off.  Update the comments to reflect
that, and fix a remaining check against NPF_SURFACE_MOBILE_NONPROMISC.

(cherry picked from commit 88926013e35cd3999c9cdd029c491c535496d261)
---

diff --git a/pcap-npf.c b/pcap-npf.c
index c531a393..62c526d9 100644
--- a/pcap-npf.c
+++ b/pcap-npf.c
@@ -1003,16 +1003,10 @@ pcap_breakloop_npf(pcap_t *p)
  *
  * but I don't know why the goal was to avoid that translation.
  *
- * Attempting to set non-promiscuous mode on a Microsoft Surface Pro's
+ * Attempting to set the hardware filter on a Microsoft Surface Pro's
  * Mobile Broadband Adapter returns an error that appears to be
  * NDIS_STATUS_NOT_SUPPORTED ORed with the "Customer" bit, so it's
- * probably indicating that it doesn't support promiscuous mode,
- * as one might expect, given that it's not going to promiscuously
- * snoop for arbitrary mobile telecom network packets.  That error can
- * safely be ignored, as it's always in non-promiscuous mode; an
- * alternative would be to report the PCAP_WARNING_PROMISC_NOTSUP
- * warning, which indicates that the activate call succeeded but
- * that something happened that the user might want to know about.
+ * probably indicating that it doesn't support that.
  *
  * It is likely that there are other devices which throw spurious errors,
  * at which point this will need refactoring to efficiently check against
@@ -1310,14 +1304,13 @@ pcap_activate_npf(pcap_t *p)
 
 			/*
 			 * Suppress spurious error generated by non-compiant
-			 * MS Surface mobile adapters.
+			 * MS Surface mobile adapters that appear to
+			 * return NDIS_STATUS_NOT_SUPPORTED for attempts
+			 * to set the hardware filter.
 			 *
-			 * It appears to be reporting STATUS_NOT_SUPPORTED
-			 * (ndis.h defines NDIS_STATUS_NOT_SUPPORTED to
-			 * have the same value as the NT status value
-			 * STATUS_NOT_SUPPORTED), but with the NT status
-			 * value "Customer" bit set, probably by the
-			 * Npcap NPF driver.
+			 * It appears to be reporting NDIS_STATUS_NOT_SUPPORTED,
+			 * but with the NT status value "Customer" bit set;
+			 * the Npcap NPF driver sets that bit in some cases.
 			 *
 			 * If we knew that this meant "promiscuous mode
 			 * isn't supported", we could add a "promiscuous
@@ -1380,7 +1373,7 @@ pcap_activate_npf(pcap_t *p)
 			 * Suppress spurious error generated by non-compiant
 			 * MS Surface mobile adapters.
 			 */
-			if (errcode != NPF_SURFACE_MOBILE_NONPROMISC)
+			if (errcode != (NDIS_STATUS_NOT_SUPPORTED|NT_STATUS_CUSTOMER_DEFINED))
 			{
 				pcap_fmt_errmsg_for_win32_err(p->errbuf,
 				    PCAP_ERRBUF_SIZE, errcode,