Index: vl.c
===================================================================
RCS file: /sources/qemu/qemu/vl.c,v
retrieving revision 1.306
diff -u -r1.306 vl.c
--- vl.c	10 Jun 2007 19:21:04 -0000	1.306
+++ vl.c	21 Jun 2007 19:13:32 -0000
@@ -3157,6 +3157,12 @@
     while (*pvlan != NULL)
         pvlan = &(*pvlan)->next;
     *pvlan = vlan;
+	
+	//initialize the packet capture options
+	vlan->pcap_file = NULL;	
+	vlan->last_written_time = 0;
+	vlan->packet_serial_num = 0;
+	
     return vlan;
 }
 
@@ -3200,6 +3206,22 @@
 {
     VLANState *vlan = vc1->vlan;
     VLANClientState *vc;
+	PCAPRecordHeader pcap_record_header;
+	
+	if (vlan->pcap_file) {
+		pcap_record_header.ts_sec = time(NULL);
+		if (pcap_record_header.ts_sec == vlan->last_written_time) {
+			pcap_record_header.ts_usec = vlan->last_written_time;
+			if (vlan->last_written_time < 9999) vlan->last_written_time++;
+		} else {
+			pcap_record_header.ts_usec = 0;
+			vlan->last_written_time = 0;
+		}		
+		pcap_record_header.orig_len = size;
+		pcap_record_header.incl_len = (size > 0xFFFF) ? 0xFFFF : size;
+		fwrite(&pcap_record_header, sizeof(pcap_record_header), 1, vlan->pcap_file);
+		fwrite(buf, pcap_record_header.incl_len, 1, vlan->pcap_file);		
+	}
 
 #if 0
     printf("vlan %d send:\n", vlan->id);
@@ -4194,6 +4216,24 @@
         if (get_param_value(buf, sizeof(buf), "model", p)) {
             nd->model = strdup(buf);
         }
+		if (get_param_value(buf, sizeof(buf), "pcap", p)) {
+			vlan->pcap_file = fopen(buf, "wb");
+			if (!vlan->pcap_file) {
+				fprintf(stderr, "failed to open pcap file: %d\n", errno);
+				return -1;
+			}
+			//write out the standard tcpdump file header
+			//reference: http://wiki.wireshark.org/Development/LibpcapFileFormat
+			PCAPHeader hdr;
+			hdr.magic_number = 0xa1b2c3d4;
+			hdr.version_major = 2;
+			hdr.version_minor = 4;
+			hdr.thiszone = 0;
+			hdr.sigfigs = 0;
+			hdr.snaplen = 0xFFFF;
+			hdr.network = 1;
+			fwrite(&hdr, sizeof(hdr), 1, vlan->pcap_file);			
+		}
         nd->vlan = vlan;
         nb_nics++;
         vlan->nb_guest_devs++;
@@ -6585,7 +6625,7 @@
            "-name string    set the name of the guest\n"
            "\n"
            "Network options:\n"
-           "-net nic[,vlan=n][,macaddr=addr][,model=type]\n"
+           "-net nic[,vlan=n][,macaddr=addr][,model=type][,pcap=file]\n"
            "                create a new Network Interface Card and connect it to VLAN 'n'\n"
 #ifdef CONFIG_SLIRP
            "-net user[,vlan=n][,hostname=host]\n"
Index: vl.h
===================================================================
RCS file: /sources/qemu/qemu/vl.h,v
retrieving revision 1.252
diff -u -r1.252 vl.h
--- vl.h	18 Jun 2007 18:55:46 -0000	1.252
+++ vl.h	21 Jun 2007 19:14:11 -0000
@@ -390,6 +390,12 @@
     VLANClientState *first_client;
     struct VLANState *next;
     unsigned int nb_guest_devs, nb_host_devs;
+		
+	//used to perform packed capture
+	//and to set the time stamps on the captured packets
+	FILE *pcap_file;
+	time_t last_written_time;
+	int packet_serial_num;
 } VLANState;
 
 VLANState *qemu_find_vlan(int id);
@@ -402,6 +408,24 @@
 void qemu_handler_true(void *opaque);
 
 void do_info_network(void);
+/* PCAP file structures */
+
+typedef struct PCAPHeader { 
+        unsigned int magic_number;   /* magic number */
+        unsigned short int version_major;  /* major version number */
+        unsigned short int version_minor;  /* minor version number */
+        int  thiszone;       /* GMT to local correction */
+        unsigned int sigfigs;        /* accuracy of timestamps */
+        unsigned int snaplen;        /* max length of captured packets, in octets */
+        unsigned int network;        /* data link type */
+} PCAPHeader;
+
+typedef struct PCAPRecordHeader { 
+        unsigned int ts_sec;         /* timestamp seconds */
+        unsigned int ts_usec;        /* timestamp microseconds */
+        unsigned int incl_len;       /* number of octets of packet saved in file */
+        unsigned int orig_len;       /* actual length of packet */
+} PCAPRecordHeader;
 
 /* TAP win32 */
 int tap_win32_init(VLANState *vlan, const char *ifname);