int main()
{
char errbuf[PCAP_ERRBUF_SIZE];
const u_char * pkt_data;
struct pcap_pkthdr * pkt_hdr;
pcap_t * pcap;
/*
char * dev = pcap_lookupdev(errbuf);
if(!dev) {
printf("Could not init interface: %s\n", errbuf);
return 0;
}
*/
pcap = pcap_open_live("any", 1<<16, 1, 1<<30, errbuf);
if(!pcap) {
printf("Could not init interface: %s\n", errbuf);
return 0;
}
printf("Blocking status: %u\n", pcap_getnonblock(pcap, errbuf));
while((pkt_data = pcap_next(pcap, pkt_hdr))) {
//printf("%d.%d\n", pkt_hdr->ts.tv_sec, pkt_hdr->ts.tv_usec);
printf("%.*s", pkt_hdr->caplen, pkt_data);
}
return 1;
}
int pcap_ex_getnonblock(pcap_t *pcap, char *ebuf)
{
#ifdef HAVE_PCAP_SETNONBLOCK
return (pcap_getnonblock(pcap, ebuf));
#else
return (0);
#endif
}
static PyObject * p_getnonblock (PyObject *self, PyObject *args)
{
pcap_t * ppcap;
int nonblock;
char errbuf[PCAP_ERRBUF_SIZE];
if (!PyArg_ParseTuple(args, "l", (long*)&ppcap)) return NULL;
nonblock = pcap_getnonblock(ppcap, errbuf);
if (nonblock == -1)
{
PyErr_SetString(PyExc_RuntimeError, errbuf);
return NULL;
}
return Py_BuildValue("i", nonblock);
}
/**
* Set up pcap listener for the given interfaces and protocols.
* @return a properly configured pcap_t* object for listening for the given protocols - NULL on error
* @see pcap_protocols
*/
pcap_t*
create_pcap_listener(const char * dev ///<[in] Device name to listen on
, gboolean blocking ///<[in] TRUE if this is a blocking connection
, unsigned listenmask ///<[in] Bit mask of protocols to listen for
///< (see @ref pcap_protocols "list of valid bits")
, struct bpf_program*prog) ///<[out] Compiled PCAP program
{
pcap_t* pcdescr = NULL;
bpf_u_int32 maskp = 0;
bpf_u_int32 netp = 0;
char errbuf[PCAP_ERRBUF_SIZE];
char * expr = NULL;
int filterlen = 1;
unsigned j;
int cnt=0;
int rc;
const char ORWORD [] = " or ";
gboolean need_promisc = FALSE;
BINDDEBUG(pcap_t);
// setbuf(stdout, NULL);
setvbuf(stdout, NULL, _IONBF, 0);
errbuf[0] = '\0';
// Search the list of valid bits so we can construct the libpcap filter
// for the given set of protocols on the fly...
// On this pass we just compute the amount of memory we'll need...
for (j = 0, cnt = 0; j < DIMOF(filterinfo); ++j) {
if (listenmask & filterinfo[j].filterbit) {
++cnt;
if (cnt > 1) {
filterlen += sizeof(ORWORD);
}
filterlen += strlen(filterinfo[j].filter);
}
}
if (filterlen < 2) {
g_warning("Constructed filter is too short - invalid mask argument.");
return NULL;
}
if (NULL == (expr = malloc(filterlen))) {
g_error("Out of memory!");
return NULL;
}
// Same song, different verse...
// This time around, we construct the filter
expr[0] = '\0';
for (j = 0, cnt = 0; j < DIMOF(filterinfo); ++j) {
if (listenmask & filterinfo[j].filterbit) {
++cnt;
if (cnt > 1) {
g_strlcat(expr, ORWORD, filterlen);
}
g_strlcat(expr, filterinfo[j].filter, filterlen);
}
}
if (pcap_lookupnet(dev, &netp, &maskp, errbuf) != 0) {
// This is not a problem for non-IPv4 protocols...
// It just looks up the ipv4 address - which we mostly don't care about.
g_info("%s.%d: pcap_lookupnet(\"%s\") failed: [%s]"
, __FUNCTION__, __LINE__, dev, errbuf);
}
if (NULL == (pcdescr = pcap_create(dev, errbuf))) {
g_warning("pcap_create failed: [%s]", errbuf);
goto oopsie;
}
//pcap_set_promisc(pcdescr, FALSE);
for (j = 0; j < DIMOF(filterinfo); ++j) {
if (listenmask & filterinfo[j].filterbit) {
const char * addrstring = filterinfo[j].mcastaddr;
if (addrstring && !_enable_mcast_address(addrstring, dev, TRUE)) {
need_promisc = TRUE;
}
}
}
pcap_set_promisc(pcdescr, need_promisc);
#ifdef HAVE_PCAP_SET_RFMON
pcap_set_rfmon(pcdescr, FALSE);
#endif
pcap_setdirection(pcdescr, PCAP_D_IN);
// Weird bug - returns -3 and doesn't show an error message...
// And pcap_getnonblock also returns -3... Neither should happen AFAIK...
errbuf[0] = '\0';
if ((rc = pcap_setnonblock(pcdescr, !blocking, errbuf)) < 0 && errbuf[0] != '\0') {
g_warning("pcap_setnonblock(%d) failed: [%s] [rc=%d]", !blocking, errbuf, rc);
g_warning("Have no idea why this happens - current blocking state is: %d."
, pcap_getnonblock(pcdescr, errbuf));
}
pcap_set_snaplen(pcdescr, 1500);
/// @todo deal with pcap_set_timeout() call here.
if (blocking) {
pcap_set_timeout(pcdescr, 240*1000);
} else {
pcap_set_timeout(pcdescr, 1);
}
//pcap_set_buffer_size(pcdescr, 1500);
if (pcap_activate(pcdescr) != 0) {
g_warning("pcap_activate failed: [%s]", pcap_geterr(pcdescr));
goto oopsie;
}
if (pcap_compile(pcdescr, prog, expr, FALSE, maskp) < 0) {
g_warning("pcap_compile of [%s] failed: [%s]", expr, pcap_geterr(pcdescr));
goto oopsie;
}
if (pcap_setfilter(pcdescr, prog) < 0) {
g_warning("pcap_setfilter on [%s] failed: [%s]", expr, pcap_geterr(pcdescr));
goto oopsie;
}
DEBUGMSG1("Compile of [%s] worked!", expr);
free(expr);
expr = NULL;
return(pcdescr);
oopsie: // Some kind of failure - free things up and return NULL
g_warning("%s.%d: Could not set up PCAP on %s"
, __FUNCTION__, __LINE__, dev);
if (expr) {
free(expr);
expr = NULL;
}
if (pcdescr) {
close_pcap_listener(pcdescr, dev, listenmask);
pcdescr = NULL;
}
return NULL;
}
