From: guy <guy>
Date: Tue, 3 May 2005 18:53:58 +0000 (+0000)
Subject: From Pawel Pokrywka: add support for requesting that only received
X-Git-Tag: libpcap-1.1.0~623
X-Git-Url: https://git.tcpdump.org/libpcap/commitdiff_plain/e987a615e2b8d2c9215eb3b6c14ec18845c20daa

From Pawel Pokrywka: add support for requesting that only received
packets, only sent packets, or all packets be accepted, with an
implementation for Linux.

Add an implementation for BPF platforms that support BIOCSSEESENT.
---

diff --git a/CREDITS b/CREDITS
index 7c0e9cc0..7797b9ee 100644
--- a/CREDITS
+++ b/CREDITS
@@ -71,6 +71,7 @@ Additional people who have contributed patches:
 	Patrick Marie			<mycroft@virgaria.org>
 	Paul Mundt			<lethal@linux-sh.org>
 	Pavel Kankovsky			<kan@dcit.cz>
+	Pawel Pokrywka			<publicpp@gmail.com>
 	Peter Fales			<peter@fales-lorenz.net>
 	Peter Jeremy			<peter.jeremy@alcatel.com.au>
 	Phil Wood			<cpw@lanl.gov>
diff --git a/pcap-bpf.c b/pcap-bpf.c
index 491d4ed2..42318a1d 100644
--- a/pcap-bpf.c
+++ b/pcap-bpf.c
@@ -20,7 +20,7 @@
  */
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.88 2005-04-21 02:41:12 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.89 2005-05-03 18:53:58 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -105,6 +105,7 @@ static int odmlockid = 0;
 #include "gencode.h"	/* for "no_optimize" */
 
 static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp);
+static int pcap_setdirection_bpf(pcap_t *, direction_t);
 static int pcap_set_datalink_bpf(pcap_t *p, int dlt);
 
 static int
@@ -1019,6 +1020,7 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 	p->read_op = pcap_read_bpf;
 	p->inject_op = pcap_inject_bpf;
 	p->setfilter_op = pcap_setfilter_bpf;
+	p->setdirection_op = pcap_setdirection_bpf;
 	p->set_datalink_op = pcap_set_datalink_bpf;
 	p->getnonblock_op = pcap_getnonblock_fd;
 	p->setnonblock_op = pcap_setnonblock_fd;
@@ -1088,6 +1090,42 @@ pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp)
 	return (0);
 }
 
+/*
+ * Set direction flag: Which packets do we accept on a forwarding
+ * single device? IN, OUT or both?
+ */
+static int
+pcap_setdirection_bpf(pcap_t *p, direction_t d)
+{
+#ifdef BIOCSSEESENT
+	u_int seesent;
+#endif
+
+	/*
+	 * We don't support D_OUT.
+	 */
+	if (d == D_OUT) {
+		snprintf(p->errbuf, sizeof(p->errbuf),
+		    "Setting direction to D_OUT is not supported on BPF");
+		return -1;
+	}
+#ifdef BIOCSSEESENT
+	seesent = (d == D_INOUT);
+	if (ioctl(p->fd, BIOCSSEESENT, &seesent) == -1) {
+		(void) snprintf(p->errbuf, sizeof(p->errbuf),
+		    "Cannot set direction to %s: %s",
+		        (d == D_INOUT) ? "D_INOUT" : "D_IN",
+			strerror(errno));
+		return (-1);
+	}
+	return (0);
+#else
+	(void) snprintf(p->errbuf, sizeof(p->errbuf),
+	    "This system doesn't support BIOCSSEESENT, so the direction can't be set");
+	return (-1);
+#endif
+}
+
 static int
 pcap_set_datalink_bpf(pcap_t *p, int dlt)
 {
diff --git a/pcap-dag.c b/pcap-dag.c
index 5aba689b..13d6d173 100644
--- a/pcap-dag.c
+++ b/pcap-dag.c
@@ -15,7 +15,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-	"@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.21 2005-04-03 23:56:47 guy Exp $ (LBL)";
+	"@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.22 2005-05-03 18:53:58 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -507,6 +507,7 @@ dag_open_live(const char *device, int snaplen, int promisc, int to_ms, char *ebu
 	handle->read_op = dag_read;
 	handle->inject_op = dag_inject;
 	handle->setfilter_op = dag_setfilter;
+	handle->setdirection_op = NULL; /* Not implemented.*/
 	handle->set_datalink_op = dag_set_datalink;
 	handle->getnonblock_op = pcap_getnonblock_fd;
 	handle->setnonblock_op = dag_setnonblock;
diff --git a/pcap-dlpi.c b/pcap-dlpi.c
index 22c1dfd3..a9fa6b82 100644
--- a/pcap-dlpi.c
+++ b/pcap-dlpi.c
@@ -70,7 +70,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-dlpi.c,v 1.113 2005-04-17 17:25:51 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-dlpi.c,v 1.114 2005-05-03 18:53:58 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -933,6 +933,7 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 	p->read_op = pcap_read_dlpi;
 	p->inject_op = pcap_inject_dlpi;
 	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
+	p->setdirection_op = NULL;	/* Not implemented.*/
 	p->set_datalink_op = NULL;	/* can't change data link type */
 	p->getnonblock_op = pcap_getnonblock_fd;
 	p->setnonblock_op = pcap_setnonblock_fd;
diff --git a/pcap-dos.c b/pcap-dos.c
index 26a925b3..9e4df2b3 100644
--- a/pcap-dos.c
+++ b/pcap-dos.c
@@ -5,7 +5,7 @@
  *  pcap-dos.c: Interface to PKTDRVR, NDIS2 and 32-bit pmode
  *              network drivers.
  *
- * @(#) $Header: /tcpdump/master/libpcap/pcap-dos.c,v 1.1 2004-12-18 08:52:10 guy Exp $ (LBL)
+ * @(#) $Header: /tcpdump/master/libpcap/pcap-dos.c,v 1.2 2005-05-03 18:53:59 guy Exp $ (LBL)
  */
 
 #include <stdio.h>
@@ -172,6 +172,7 @@ pcap_t *pcap_open_live (const char *device_name, int snaplen, int promisc,
   pcap->stats_op          = pcap_stats_dos;
   pcap->inject_op         = pcap_sendpacket_dos;
   pcap->setfilter_op      = pcap_setfilter_dos;
+	pcap->setdirection_op   = NULL; /* Not implemented.*/
   pcap->fd                = ++ref_count;
 
   if (pcap->fd == 1)  /* first time we're called */
diff --git a/pcap-int.h b/pcap-int.h
index 0c50473f..cd2d4f00 100644
--- a/pcap-int.h
+++ b/pcap-int.h
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * @(#) $Header: /tcpdump/master/libpcap/pcap-int.h,v 1.70 2005-04-07 02:47:34 guy Exp $ (LBL)
+ * @(#) $Header: /tcpdump/master/libpcap/pcap-int.h,v 1.71 2005-05-03 18:53:59 guy Exp $ (LBL)
  */
 
 #ifndef pcap_int_h
@@ -150,12 +150,16 @@ struct pcap {
 	 */
 	u_char *pkt;
 
+	/* We're accepting only packets in this direction/these directions. */
+	direction_t direction;
+
 	/*
 	 * Methods.
 	 */
 	int	(*read_op)(pcap_t *, int cnt, pcap_handler, u_char *);
 	int	(*inject_op)(pcap_t *, const void *, size_t);
 	int	(*setfilter_op)(pcap_t *, struct bpf_program *);
+	int	(*setdirection_op)(pcap_t *, direction_t);
 	int	(*set_datalink_op)(pcap_t *, int);
 	int	(*getnonblock_op)(pcap_t *, char *);
 	int	(*setnonblock_op)(pcap_t *, int, char *);
diff --git a/pcap-linux.c b/pcap-linux.c
index 3daa661e..307da05c 100644
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -27,7 +27,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.110 2004-10-19 07:06:12 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.111 2005-05-03 18:53:59 guy Exp $ (LBL)";
 #endif
 
 /*
@@ -191,6 +191,7 @@ static int pcap_read_packet(pcap_t *, pcap_handler, u_char *);
 static int pcap_inject_linux(pcap_t *, const void *, size_t);
 static int pcap_stats_linux(pcap_t *, struct pcap_stat *);
 static int pcap_setfilter_linux(pcap_t *, struct bpf_program *);
+static int pcap_setdirection_linux(pcap_t *, direction_t);
 static void pcap_close_linux(pcap_t *);
 
 /*
@@ -407,6 +408,7 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 	handle->read_op = pcap_read_linux;
 	handle->inject_op = pcap_inject_linux;
 	handle->setfilter_op = pcap_setfilter_linux;
+	handle->setdirection_op = pcap_setdirection_linux;
 	handle->set_datalink_op = NULL;	/* can't change data link type */
 	handle->getnonblock_op = pcap_getnonblock_fd;
 	handle->setnonblock_op = pcap_setnonblock_fd;
@@ -504,19 +506,37 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata)
 	}
 
 #ifdef HAVE_PF_PACKET_SOCKETS
-	/*
-	 * If this is from the loopback device, reject outgoing packets;
-	 * we'll see the packet as an incoming packet as well, and
-	 * we don't want to see it twice.
-	 *
-	 * We can only do this if we're using PF_PACKET; the address
-	 * returned for SOCK_PACKET is a "sockaddr_pkt" which lacks
-	 * the relevant packet type information.
-	 */
-	if (!handle->md.sock_packet &&
-	    from.sll_ifindex == handle->md.lo_ifindex &&
-	    from.sll_pkttype == PACKET_OUTGOING)
-		return 0;
+	if (!handle->md.sock_packet) {
+		/*
+		 * Do checks based on packet direction.
+		 * We can only do this if we're using PF_PACKET; the
+		 * address returned for SOCK_PACKET is a "sockaddr_pkt"
+		 * which lacks the relevant packet type information.
+		 */
+		if (from.sll_pkttype == PACKET_OUTGOING) {
+			/*
+			 * Outgoing packet.
+			 * If this is from the loopback device, reject it;
+			 * we'll see the packet as an incoming packet as well,
+			 * and we don't want to see it twice.
+			 */
+			if (from.sll_ifindex == handle->md.lo_ifindex)
+				return 0;
+
+			/*
+			 * If the user only wants incoming packets, reject it.
+			 */
+			if (handle->direction == D_IN)
+				return 0;
+		} else {
+			/*
+			 * Incoming packet.
+			 * If the user only wants outgoing packets, reject it.
+			 */
+			if (handle->direction == D_OUT)
+				return 0;
+		}
+	}
 #endif
 
 #ifdef HAVE_PF_PACKET_SOCKETS
@@ -974,6 +994,28 @@ pcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter)
 	return 0;
 }
 
+/*
+ * Set direction flag: Which packets do we accept on a forwarding
+ * single device? IN, OUT or both?
+ */
+static int
+pcap_setdirection_linux(pcap_t *handle, direction_t d)
+{
+#ifdef HAVE_PF_PACKET_SOCKETS
+	if (!handle->md.sock_packet) {
+		handle->direction = d;
+		return 0;
+	}
+#endif
+	/*
+	 * We're not using PF_PACKET sockets, so we can't determine
+	 * the direction of the packet.
+	 */
+	snprintf(handle->errbuf, sizeof(handle->errbuf),
+	    "Setting direction is not supported on SOCK_PACKET sockets");
+	return -1;
+}
+
 /*
  *  Linux uses the ARP hardware type to identify the type of an
  *  interface. pcap uses the DLT_xxx constants for this. This
diff --git a/pcap-nit.c b/pcap-nit.c
index 6a8d3186..3ef52452 100644
--- a/pcap-nit.c
+++ b/pcap-nit.c
@@ -20,7 +20,7 @@
  */
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.57 2004-10-19 07:06:13 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.58 2005-05-03 18:54:00 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -334,6 +334,7 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 	p->read_op = pcap_read_nit;
 	p->inject_op = pcap_inject_nit;
 	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
+	p->setdirection_op = NULL;	/* Not implemented. */
 	p->set_datalink_op = NULL;	/* can't change data link type */
 	p->getnonblock_op = pcap_getnonblock_fd;
 	p->setnonblock_op = pcap_setnonblock_fd;
diff --git a/pcap-pf.c b/pcap-pf.c
index db6c7e7d..5a479dd8 100644
--- a/pcap-pf.c
+++ b/pcap-pf.c
@@ -24,7 +24,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-pf.c,v 1.92 2005-04-19 00:55:48 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-pf.c,v 1.93 2005-05-03 18:54:00 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -497,6 +497,7 @@ your system may not be properly configured; see the packetfilter(4) man page\n",
 	p->read_op = pcap_read_pf;
 	p->inject_op = pcap_inject_pf;
 	p->setfilter_op = pcap_setfilter_pf;
+	p->setdirection_op = NULL;	/* Not implemented. */
 	p->set_datalink_op = NULL;	/* can't change data link type */
 	p->getnonblock_op = pcap_getnonblock_fd;
 	p->setnonblock_op = pcap_setnonblock_fd;
diff --git a/pcap-snit.c b/pcap-snit.c
index 447f343f..35004815 100644
--- a/pcap-snit.c
+++ b/pcap-snit.c
@@ -25,7 +25,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.72 2004-10-19 07:06:13 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.73 2005-05-03 18:54:00 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -397,6 +397,7 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 	p->read_op = pcap_read_snit;
 	p->inject_op = pcap_inject_snit;
 	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
+	p->setdirection_op = NULL;	/* Not implemented. */
 	p->set_datalink_op = NULL;	/* can't change data link type */
 	p->getnonblock_op = pcap_getnonblock_fd;
 	p->setnonblock_op = pcap_setnonblock_fd;
diff --git a/pcap-snoop.c b/pcap-snoop.c
index 7a27b10b..e4545c44 100644
--- a/pcap-snoop.c
+++ b/pcap-snoop.c
@@ -20,7 +20,7 @@
  */
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-snoop.c,v 1.54 2004-10-19 07:06:14 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-snoop.c,v 1.55 2005-05-03 18:54:00 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -379,6 +379,7 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 	p->read_op = pcap_read_snoop;
 	p->inject_op = pcap_inject_snoop;
 	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
+	p->setdirection_op = NULL;	/* Not implemented. */
 	p->set_datalink_op = NULL;	/* can't change data link type */
 	p->getnonblock_op = pcap_getnonblock_fd;
 	p->setnonblock_op = pcap_setnonblock_fd;
diff --git a/pcap-win32.c b/pcap-win32.c
index f6e37cf0..f2bab606 100644
--- a/pcap-win32.c
+++ b/pcap-win32.c
@@ -32,7 +32,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-win32.c,v 1.25 2005-02-26 21:58:06 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-win32.c,v 1.26 2005-05-03 18:54:01 guy Exp $ (LBL)";
 #endif
 
 #include <pcap-int.h>
@@ -602,6 +602,8 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
 #ifdef HAVE_DAG_API
 	}
 #endif /* HAVE_DAG_API */
+	p->setdirection_op = NULL;	/* Not implemented. */
+	    /* XXX - can this be implemented on some versions of Windows? */
 	p->inject_op = pcap_inject_win32;
 	p->set_datalink_op = NULL;	/* can't change data link type */
 	p->getnonblock_op = pcap_getnonblock_win32;
diff --git a/pcap.3 b/pcap.3
index 25e2f470..e4dc8802 100644
--- a/pcap.3
+++ b/pcap.3
@@ -1,4 +1,4 @@
-.\" @(#) $Header: /tcpdump/master/libpcap/Attic/pcap.3,v 1.65 2005-04-13 18:59:41 mcr Exp $
+.\" @(#) $Header: /tcpdump/master/libpcap/Attic/pcap.3,v 1.66 2005-05-03 18:54:01 guy Exp $
 .\"
 .\" Copyright (c) 1994, 1996, 1997
 .\"	The Regents of the University of California.  All rights reserved.
@@ -79,7 +79,8 @@ int pcap_compile(pcap_t *p, struct bpf_program *fp,
 .ti +8
 char *str, int optimize, bpf_u_int32 netmask)
 int pcap_setfilter(pcap_t *p, struct bpf_program *fp)
-void pcap_freecode(struct bpf_program *);
+void pcap_freecode(struct bpf_program *)
+int pcap_setdirection(pcap_t *p, direction_t d)
 .ft
 .LP
 .ft B
@@ -777,6 +778,30 @@ when that BPF program is no longer needed, for example after it
 has been made the filter program for a pcap structure by a call to
 .BR pcap_setfilter() .
 .PP
+.B pcap_setdirection()
+is used to specify a direction that packets will be captured.
+.I direction_t 
+is one of the constants
+.BR D_IN ,
+.B D_OUT
+or 
+.BR D_INOUT .
+.B D_IN
+will only capture packets received by the device,
+.B D_OUT
+will only capture packets sent by the device and
+.B D_INOUT
+will capture packets received by or sent by the device.
+.B D_INOUT
+is the default setting if this function is not called.  This isn't
+necessarily supported on all platforms; some platforms might return an
+error, and some other platforms might not support
+.BR D_OUT .
+.B \-1
+is returned on failure,
+.B 0
+is returned on success.
+.PP
 .B pcap_datalink()
 returns the link layer type; link layer types it can return include:
 .PP
diff --git a/pcap.c b/pcap.c
index 8aba35a3..dcb31249 100644
--- a/pcap.c
+++ b/pcap.c
@@ -33,7 +33,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.88 2005-02-08 20:03:15 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.89 2005-05-03 18:54:01 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -685,6 +685,23 @@ pcap_setfilter(pcap_t *p, struct bpf_program *fp)
 	return p->setfilter_op(p, fp);
 }
 
+/*
+ * Set direction flag, which controls whether we accept only incoming
+ * packets, only outgoing packets, or both.
+ * Note that, depending on the platform, some or all direction arguments
+ * might not be supported.
+ */
+int
+pcap_setdirection(pcap_t *p, direction_t d)
+{
+	if (p->setdirection_op == NULL) {
+		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
+		    "Setting direction is not implemented on this platform");
+		return -1;
+	} else
+		return p->setdirection_op(p, d);
+}
+
 int
 pcap_stats(pcap_t *p, struct pcap_stat *ps)
 {
diff --git a/pcap.h b/pcap.h
index bfa81992..f8a8f035 100644
--- a/pcap.h
+++ b/pcap.h
@@ -31,7 +31,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * @(#) $Header: /tcpdump/master/libpcap/pcap.h,v 1.52 2004-12-18 08:52:11 guy Exp $ (LBL)
+ * @(#) $Header: /tcpdump/master/libpcap/pcap.h,v 1.53 2005-05-03 18:54:02 guy Exp $ (LBL)
  */
 
 #ifndef lib_pcap_h
@@ -120,6 +120,12 @@ struct pcap_file_header {
 	bpf_u_int32 linktype;	/* data link type (LINKTYPE_*) */
 };
 
+typedef enum {
+       D_INOUT = 0,
+       D_IN,
+       D_OUT
+} direction_t;
+
 /*
  * Each packet in the dump file is prepended with this generic header.
  * This gets around the problem of different headers for different
@@ -218,6 +224,7 @@ int 	pcap_next_ex(pcap_t *, struct pcap_pkthdr **, const u_char **);
 void	pcap_breakloop(pcap_t *);
 int	pcap_stats(pcap_t *, struct pcap_stat *);
 int	pcap_setfilter(pcap_t *, struct bpf_program *);
+int 	pcap_setdirection(pcap_t *, direction_t);
 int	pcap_getnonblock(pcap_t *, char *);
 int	pcap_setnonblock(pcap_t *, int, char *);
 void	pcap_perror(pcap_t *, char *);