/**
* @param snaplen
* @param dlt
* @param bpfExpression
* @param mode
* @param netmask
* @return a {@link org.pcap4j.core.BpfProgram BpfProgram} object.
* @throws PcapNativeException
*/
public static BpfProgram compileFilter(
int snaplen,
DataLinkType dlt,
String bpfExpression,
BpfCompileMode mode,
Inet4Address netmask)
throws PcapNativeException {
if (dlt == null || bpfExpression == null || mode == null || netmask == null) {
StringBuilder sb = new StringBuilder();
sb.append("dlt: ")
.append(dlt)
.append(" bpfExpression: ")
.append(bpfExpression)
.append(" mode: ")
.append(mode)
.append(" netmask: ")
.append(netmask);
throw new NullPointerException(sb.toString());
}
bpf_program prog = new bpf_program();
int rc =
NativeMappings.pcap_compile_nopcap(
snaplen,
dlt.value(),
prog,
bpfExpression,
mode.getValue(),
ByteArrays.getInt(ByteArrays.toByteArray(netmask), 0));
if (rc < 0) {
throw new PcapNativeException("Failed to compile the BPF expression: " + bpfExpression, rc);
}
return new BpfProgram(prog, bpfExpression);
}
/**
* @param dlt
* @return a short description of that data link type.
* @throws PcapNativeException
*/
public static String dataLinkTypeToDescription(DataLinkType dlt) throws PcapNativeException {
if (dlt == null) {
StringBuilder sb = new StringBuilder();
sb.append("dlt: ").append(dlt);
throw new NullPointerException(sb.toString());
}
return dataLinkValToDescription(dlt.value());
}
/**
* @param name a data link type name, which is a DLT_ name with the DLT_ removed.
* @return a {@link org.pcap4j.packet.namednumber.DataLinkType DataLinkType} object.
* @throws PcapNativeException
*/
public static DataLinkType dataLinkNameToVal(String name) throws PcapNativeException {
if (name == null) {
StringBuilder sb = new StringBuilder();
sb.append("name: ").append(name);
throw new NullPointerException(sb.toString());
}
int rc = NativeMappings.pcap_datalink_name_to_val(name);
if (rc < 0) {
throw new PcapNativeException(
"Failed to convert the data link name to the value: " + name, rc);
}
return DataLinkType.getInstance(rc);
}
/**
* @param dlt
* @param snaplen Snapshot length, which is the number of bytes captured for each packet.
* @return a new PcapHandle object.
* @throws PcapNativeException
*/
public static PcapHandle openDead(DataLinkType dlt, int snaplen) throws PcapNativeException {
if (dlt == null) {
StringBuilder sb = new StringBuilder();
sb.append("dlt: ").append(dlt);
throw new NullPointerException(sb.toString());
}
Pointer handle = NativeMappings.pcap_open_dead(dlt.value(), snaplen);
if (handle == null) {
StringBuilder sb = new StringBuilder(50);
sb.append("Failed to open a PcapHandle. dlt: ")
.append(dlt)
.append(" snaplen: ")
.append(snaplen);
throw new PcapNativeException(sb.toString());
}
return new PcapHandle(handle);
}