From 3dae043c2a0c4d855719f5f34b6702995c82b7bb Mon Sep 17 00:00:00 2001
From: rpm-build <rpm-build>
Date: Mon, 20 Feb 2017 11:01:19 +0100
Subject: [PATCH] Change -P to -Q and print warning

Guy Harris points that -P is already taken by MacOS derived work and
that the only remaining single-letter option is -Q (see GH #252). Fix
some formatting while at it.
---
 tcpdump.1.in |  4 ++--
 tcpdump.c    | 23 +++++++++++++----------
 2 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/tcpdump.1.in b/tcpdump.1.in
index c711a24..10b7542 100644
--- a/tcpdump.1.in
+++ b/tcpdump.1.in
@@ -74,7 +74,7 @@ tcpdump \- dump traffic on a network
 .B \-\-number
 ]
 [
-.B \-Q
+.B \-Q|\-P
 .I in|out|inout
 ]
 .ti +8
@@ -586,7 +586,7 @@ Note that the interface might be in promiscuous
 mode for some other reason; hence, `-p' cannot be used as an abbreviation for
 `ether host {local-hw-addr} or ether broadcast'.
 .TP
-.BI \-Q " direction"
+.BI \-Q|\-P " direction"
 .PD 0
 .TP
 .BI \-\-direction= direction
diff --git a/tcpdump.c b/tcpdump.c
index 18c4a5c..816fbe1 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -157,7 +157,7 @@ static int Jflag;			/* list available time stamp types */
 static int jflag = -1;			/* packet time stamp source */
 static int pflag;			/* don't go promiscuous */
 #ifdef HAVE_PCAP_SETDIRECTION
-static int Qflag = -1;			/* restrict captured packet by send/receive direction */
+static int PQflag = -1;			/* restrict captured packet by send/receive direction */
 #endif
 static int Uflag;			/* "unbuffered" output of dump files */
 static int Wflag;			/* recycle output files after this number of files */
@@ -518,12 +518,12 @@ show_devices_and_exit (void)
 #endif
 
 #ifdef HAVE_PCAP_SETDIRECTION
-#define Q_FLAG "Q:"
+#define PQ_FLAG "P:Q:"
 #else
-#define Q_FLAG
+#define PQ_FLAG
 #endif
 
-#define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" Q_FLAG "r:s:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
+#define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" PQ_FLAG "r:s:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
 
 /*
  * Long options.
@@ -1068,8 +1068,8 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
 			    pcap_statustostr(status));
 	}
 #ifdef HAVE_PCAP_SETDIRECTION
-	if (Qflag != -1) {
-		status = pcap_setdirection(pc, Qflag);
+	if (PQflag != -1) {
+		status = pcap_setdirection(pc, PQflag);
 		if (status != 0)
 			error("%s: pcap_setdirection() failed: %s",
 			      device,  pcap_geterr(pc));
@@ -1353,13 +1353,16 @@ main(int argc, char **argv)
 			break;
 
 #ifdef HAVE_PCAP_SETDIRECTION
+                case 'P':
+                        fprintf(stderr, "Warning: -P switch is not compatible with the upstream version. You should use -Q instead.\n");
+                        /* Intentional fall through */
 		case 'Q':
 			if (ascii_strcasecmp(optarg, "in") == 0)
-				Qflag = PCAP_D_IN;
+				PQflag = PCAP_D_IN;
 			else if (ascii_strcasecmp(optarg, "out") == 0)
-				Qflag = PCAP_D_OUT;
+				PQflag = PCAP_D_OUT;
 			else if (ascii_strcasecmp(optarg, "inout") == 0)
-				Qflag = PCAP_D_INOUT;
+				PQflag = PCAP_D_INOUT;
 			else
 				error("unknown capture direction `%s'", optarg);
 			break;
@@ -2639,7 +2642,7 @@ print_usage(void)
 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ] [ --number ]\n");
 #ifdef HAVE_PCAP_SETDIRECTION
 	(void)fprintf(stderr,
-"\t\t[ -Q in|out|inout ]\n");
+"\t\t[ -Q|-P in|out|inout ]\n");
 #endif
 	(void)fprintf(stderr,
 "\t\t[ -r file ] [ -s snaplen ] ");
-- 
2.9.3