(do not merge yet) Indicate no-capture and no-inject devices.

CHANGES

@@ -14,6 +14,7 @@ DayOfTheWeek, Month DD, YYYY / The Tcpdump Group
       Fix "tcpdump -i <n>" for something-only libpcap builds.
       Remove code related to Riverbed TurboCap card.
         Riverbed TurboCap hardware has reached EOA as of Jun 30 2014.
+      Indicate no-capture and no-inject devices.
     Link-layer types:
       Add LINKTYPE_ETW/DLT_ETW.
       Add LINKTYPE_NETANALYZER_NG/DLT_NETANALYZER_NG (pull request

pcap-bt-linux.c

@@ -130,7 +130,9 @@ bt_findalldevs(pcap_if_list_t *devlistp, char *err_str)
 		 * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED
 		 * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
 		 */
-		if (pcapint_add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str)  == NULL)
+		if (pcapint_add_dev(devlistp, dev_name,
+		    PCAP_IF_WIRELESS | PCAP_IF_NO_INJECT,
+		    dev_descr, err_str)  == NULL)
 		{
 			ret = PCAP_ERROR;
 			break;

pcap-bt-monitor-linux.c

@@ -80,7 +80,9 @@ bt_monitor_findalldevs(pcap_if_list_t *devlistp, char *err_str)
      * for the "any" device.
      */
     if (pcapint_add_dev(devlistp, INTERFACE_NAME,
-                PCAP_IF_WIRELESS|PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
+                PCAP_IF_WIRELESS |
+                PCAP_IF_NO_INJECT |
+                PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
                 "Bluetooth Linux Monitor", err_str) == NULL)
     {
         ret = PCAP_ERROR;

pcap-dag.c

@@ -1387,6 +1387,22 @@ dag_stream_long_description(const unsigned stream, const dag_size_t bufsize,
 	return buf;
 }
 
+static bpf_u_int32
+dag_flags(const int stream)
+{
+	/*
+	 * A DAG card associates a link status with each physical port, but not
+	 * with the data streams.  The number of ports is a matter of hardware,
+	 * the number of streams and how each stream associates with zero or
+	 * more ports is a matter of how the user configures the card.  In this
+	 * context libpcap uses the streams only (i.e. "dag0" is a shorthand
+	 * for "dag0:0"), thus the notion of link status does not apply to the
+	 * resulting libpcap DAG capture devices.
+	 */
+	return PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE |
+	    (RX_ONLY(stream) ? PCAP_IF_NO_INJECT : PCAP_IF_NO_CAPTURE);
+}
+
 /*
  * Add all DAG devices.
  */
@@ -1397,14 +1413,6 @@ dag_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
 	int dagfd;
 	const char * description;
 	int stream, rxstreams;
-	// A DAG card associates a link status with each physical port, but not
-	// with the data streams.  The number of ports is a matter of hardware,
-	// the number of streams and how each stream associates with zero or
-	// more ports is a matter of how the user configures the card.  In this
-	// context libpcap uses the streams only (i.e. "dag0" is a shorthand
-	// for "dag0:0"), thus the notion of link status does not apply to the
-	// resulting libpcap DAG capture devices.
-	const bpf_u_int32 flags = PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;
 	FILE * sysfsinfo = NULL;
 
 	/* Try all the DAGs 0-DAG_MAX_BOARDS */
@@ -1459,13 +1467,15 @@ dag_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
 					description = dag_device_description (c);
 					// a conditional shorthand device
 					if (stream == 0 &&
-					    pcapint_add_dev(devlistp, name, flags, description, errbuf) == NULL)
+					    pcapint_add_dev(devlistp, name, dag_flags(stream),
+					    description, errbuf) == NULL)
 						goto failclose;
 					// and the stream device
 					snprintf(name,  sizeof(name), "dag%d:%d", c, stream);
 					description = dag_stream_long_description(stream,
 					    dag_get_stream_buffer_size64(dagfd, stream), inf);
-					if (pcapint_add_dev(devlistp, name, flags, description, errbuf) == NULL) {
+					if (pcapint_add_dev(devlistp, name, dag_flags(stream),
+					    description, errbuf) == NULL) {
 						goto failclose;
 					}
 				}
@@ -1496,13 +1506,15 @@ dag_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
 						// a conditional shorthand device
 						description = dag_device_description(c);
 						if (stream == 0 &&
-						    pcapint_add_dev(devlistp, name, flags, description, errbuf) == NULL)
+						    pcapint_add_dev(devlistp, name, dag_flags(stream),
+						    description, errbuf) == NULL)
 							goto failclose;
 						// and the stream device
 						snprintf(name,  sizeof(name), "dag%u:%u", c, stream);
 						// TODO: Parse and describe the buffer size too.
 						description = dag_stream_short_description(stream);
-						if (pcapint_add_dev(devlistp, name, flags, description, errbuf) == NULL)
+						if (pcapint_add_dev(devlistp, name, dag_flags(stream),
+						    description, errbuf) == NULL)
 							goto failclose;
 					}
 				fclose(sysfsinfo);

pcap-dpdk.c

@@ -1039,7 +1039,7 @@ int pcap_dpdk_findalldevs(pcap_if_list_t *devlistp, char *ebuf)
 			// PCI addr
 			rte_eth_dev_get_name_by_port(i,pci_addr);
 			snprintf(dpdk_desc,DPDK_DEV_DESC_MAX-1,"%s %s, MAC:%s, PCI:%s", DPDK_DESC, dpdk_name, mac_addr, pci_addr);
-			if (pcapint_add_dev(devlistp, dpdk_name, 0, dpdk_desc, ebuf)==NULL){
+			if (pcapint_add_dev(devlistp, dpdk_name, PCAP_IF_NO_INJECT, dpdk_desc, ebuf)==NULL){
 				ret = PCAP_ERROR;
 				break;
 			}

pcap-haiku.c

@@ -451,6 +451,8 @@ get_if_flags(const char *name, bpf_u_int32 *flags, char *errbuf)
 	if (validate_ifname(name, errbuf) < 0)
 		return PCAP_ERROR;
 
+	*flags |= PCAP_IF_NO_INJECT;
+
 	if (*flags & PCAP_IF_LOOPBACK ||
 	    ! strncmp(name, "tun", strlen("tun")) ||
 	    ! strncmp(name, "tap", strlen("tap"))) {

pcap-netfilter-linux.c

@@ -784,10 +784,12 @@ netfilter_findalldevs(pcap_if_list_t *devlistp, char *err_str)
 	 * XXX - what about "up" and "running"?
 	 */
 	if (pcapint_add_dev(devlistp, NFLOG_IFACE,
+	    PCAP_IF_NO_INJECT |
 	    PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
 	    "Linux netfilter log (NFLOG) interface", err_str) == NULL)
 		return -1;
 	if (pcapint_add_dev(devlistp, NFQUEUE_IFACE,
+	    PCAP_IF_NO_INJECT |
 	    PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
 	    "Linux netfilter queue (NFQUEUE) interface", err_str) == NULL)
 		return -1;

pcap-rdmasniff.c

@@ -442,7 +442,9 @@ rdmasniff_findalldevs(pcap_if_list_t *devlistp, char *err_str)
 		 * XXX - do the notions of "up", "running", or
 		 * "connected" apply here?
 		 */
-		if (!pcapint_add_dev(devlistp, dev_list[i]->name, 0, "RDMA sniffer", err_str)) {
+		if (!pcapint_add_dev(devlistp, dev_list[i]->name,
+		    PCAP_IF_NO_INJECT,
+		    "RDMA sniffer", err_str)) {
 			ret = -1;
 			break;
 		}

pcap-usb-linux.c

@@ -152,6 +152,7 @@ usb_dev_add(pcap_if_list_t *devlistp, int n, char *err_str)
 		 * that would apply to a particular USB interface.
 		 */
 		if (pcapint_add_dev(devlistp, dev_name,
+		    PCAP_IF_NO_INJECT |
 		    PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
 		    "Raw USB traffic, all USB buses", err_str) == NULL)
 			return -1;
@@ -163,7 +164,9 @@ usb_dev_add(pcap_if_list_t *devlistp, int n, char *err_str)
 		 * PCAP_IF_CONNECTION_STATUS_DISCONNECTED?
 		 */
 		snprintf(dev_descr, sizeof(dev_descr), "Raw USB traffic, bus number %d", n);
-		if (pcapint_add_dev(devlistp, dev_name, 0, dev_descr, err_str) == NULL)
+		if (pcapint_add_dev(devlistp, dev_name,
+		    PCAP_IF_NO_INJECT,
+		    dev_descr, err_str) == NULL)
 			return -1;
 	}
 

pcap.c

@@ -1422,7 +1422,10 @@ pcap_add_any_dev(pcap_if_list_t *devlistp, char *errbuf)
 	 * doesn't apply to the "any" device.
 	 */
 	return pcapint_add_dev(devlistp, "any",
-	    PCAP_IF_UP|PCAP_IF_RUNNING|PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
+	    PCAP_IF_UP |
+	    PCAP_IF_RUNNING |
+	    PCAP_IF_NO_INJECT |
+	    PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
 	    any_descr, errbuf);
 }
 

pcap/pcap.h

@@ -336,6 +336,8 @@ struct pcap_if {
 #define PCAP_IF_CONNECTION_STATUS_CONNECTED		0x00000010	/* connected */
 #define PCAP_IF_CONNECTION_STATUS_DISCONNECTED		0x00000020	/* disconnected */
 #define PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE	0x00000030	/* not applicable */
+#define PCAP_IF_NO_CAPTURE				0x00000040	/* a no-capture device */
+#define PCAP_IF_NO_INJECT				0x00000080	/* a no-inject device */
 
 /*
  * Representation of an interface address.

pcap_activate.3pcap

@@ -17,7 +17,7 @@
 .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 .\"
-.TH PCAP_ACTIVATE 3PCAP "3 June 2024"
+.TH PCAP_ACTIVATE 3PCAP "24 November 2024"
 .SH NAME
 pcap_activate \- activate a capture handle
 .SH SYNOPSIS
@@ -90,7 +90,10 @@ monitor mode.
 The capture source device is not up.
 .TP
 .B PCAP_ERROR_CAPTURE_NOTSUP
-Packet capture is not supported on the capture source.
+Packet capture is not supported on the capture source.  See also the
+.B \%PCAP_IF_NO_CAPTURE
+device flag in
+.BR \%pcap_findalldevs (3PCAP).
 .TP
 .B PCAP_ERROR
 Another error occurred.

pcap_findalldevs.3pcap

@@ -17,7 +17,7 @@
 .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 .\"
-.TH PCAP_FINDALLDEVS 3PCAP "9 August 2024"
+.TH PCAP_FINDALLDEVS 3PCAP "24 November 2024"
 .SH NAME
 pcap_findalldevs, pcap_freealldevs \- get a list of capture devices, and
 free that list
@@ -112,6 +112,16 @@ set if the device is a wireless interface; this includes IrDA as well as
 radio-based networks such as IEEE 802.15.4 and IEEE 802.11, so it
 doesn't just mean Wi-Fi
 .TP
+.B PCAP_IF_NO_CAPTURE
+set if the device does not support packet capture in principle, thus any
+attempt to capture on the device will fail with an error; note that this flag
+.B not
+being set does not mean all attempts to capture will succeed: some may fail
+as usual because of the capture parameters, device status, permissions etc.
+.TP
+.B PCAP_IF_NO_INJECT
+same as the above, but with regard to packet injection
+.TP
 .B PCAP_IF_CONNECTION_STATUS
 a bitmask for an indication of whether the adapter is connected or not;
 for wireless interfaces, "connected" means "associated with a network"
@@ -262,5 +272,11 @@ The
 and
 .B PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE
 constants became available in libpcap release 1.9.0.
+.PP
+The
+.B PCAP_IF_NO_CAPTURE
+and
+.B PCAP_IF_NO_INJECT
+constants became available in libpcap release 1.11.0.
 .SH SEE ALSO
 .BR pcap (3PCAP)

pcap_inject.3pcap

@@ -17,7 +17,7 @@
 .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 .\"
-.TH PCAP_INJECT 3PCAP "23 November 2024"
+.TH PCAP_INJECT 3PCAP "24 November 2024"
 .SH NAME
 pcap_inject, pcap_sendpacket \- transmit a packet
 .SH SYNOPSIS
@@ -50,7 +50,10 @@ The same limitation applies to
 .BR \%pcap_create (3PCAP)
 and
 .BR \%pcap_activate (3PCAP).
-Note also that some devices might not support sending packets.
+Note also that some devices might not support sending packets.  See also the
+.B \%PCAP_IF_NO_INJECT
+device flag in
+.BR \%pcap_findalldevs (3PCAP).
 .PP
 Note that, on some platforms, the link-layer header of the packet that's
 sent might not be the same as the link-layer header of the packet

testprogs/findalldevstest.c

@@ -234,6 +234,16 @@ static int ifprint(pcap_if_t *d)
     printf("%sLOOPBACK", sep);
     sep = ", ";
   }
+#ifdef PCAP_IF_NO_CAPTURE
+  if (d->flags & PCAP_IF_NO_CAPTURE) {
+    printf("%sNO_CAPTURE", sep);
+    sep = ", ";
+  }
+  if (d->flags & PCAP_IF_NO_INJECT) {
+    printf("%sNO_INJECT", sep);
+    sep = ", ";
+  }
+#endif
   if (d->flags & PCAP_IF_WIRELESS) {
     printf("%sWIRELESS", sep);
     switch (d->flags & PCAP_IF_CONNECTION_STATUS) {