/* Attempts to read a packet from a DAG card in a NON-BLOCKING fashion. If * a packet is available, we will return a packet event. Otherwise we will * return a SLEEP event (as we cannot select on the DAG file descriptor). */ static libtrace_eventobj_t trace_event_dag(libtrace_t *trace, libtrace_packet_t *packet) { libtrace_eventobj_t event = {0,0,0.0,0}; int data; do { data = dag_available(trace); /* If no data is available, drop out and return a sleep event */ if (data <= 0) break; /* Data is available, so we can call the blocking read because * we know that we will get a packet straight away */ event.size = dag_read_packet(trace,packet); //DATA(trace)->dag.diff -= event.size; /* XXX trace_read_packet() normally applies the following * config options for us, but this function is called via * trace_event() so we have to do it ourselves */ /* Check that the packet matches any pre-existing filter */ if (trace->filter) { if (trace_apply_filter(trace->filter, packet)) { event.type = TRACE_EVENT_PACKET; } else { /* Do not sleep - try to read another packet */ trace->filtered_packets ++; continue; } } else { event.type = TRACE_EVENT_PACKET; } /* If the user has specified a snap length, apply that too */ if (trace->snaplen > 0) { trace_set_capture_length(packet, trace->snaplen); } trace->accepted_packets ++; return event; } while (1); /* We only want to sleep for a very short time */ assert(data == 0); event.type = TRACE_EVENT_SLEEP; event.seconds = 0.0001; event.size = 0; return event; }
/* Return values: * 1 = continue reading packets * 0 = stop reading packets, cos we're done * -1 = stop reading packets, we've got an error */ static int per_packet(libtrace_packet_t *packet) { double ts = trace_get_seconds(packet); if (trace_get_link_type(packet) == ~0U) { fprintf(stderr, "Halted due to being unable to determine linktype - input trace may be corrupt.\n"); return -1; } if (snaplen>0) { trace_set_capture_length(packet,snaplen); } if (ts <starttime) { return 1; } if ( ts > endtime) { //printf( "%f\t%f\n", ts, endtime); return 0; } if (firsttime==0) { time_t now = trace_get_seconds(packet); if (starttime != 0.0) { firsttime=now-((now - (int)starttime) % interval); } else { firsttime=now; } } if (output && trace_get_seconds(packet)>firsttime+interval) { trace_destroy_output(output); output=NULL; firsttime+=interval; } if (output && pktcount%count==0) { trace_destroy_output(output); output=NULL; } pktcount++; totbytes+=trace_get_capture_length(packet); if (output && totbytes-totbyteslast>=bytes) { trace_destroy_output(output); output=NULL; totbyteslast=totbytes; } if (!output) { char *buffer; bool need_ext=false; if (maxfiles <= filescreated) { return 0; } buffer=strdup(output_base); if (interval!=UINT64_MAX && maxfiles>1) { buffer=strdupcat(buffer,"-"); buffer=strdupcati(buffer,(uint64_t)firsttime); need_ext=true; } if (count!=UINT64_MAX && maxfiles>1) { buffer=strdupcat(buffer,"-"); buffer=strdupcati(buffer,(uint64_t)pktcount); need_ext=true; } if (bytes!=UINT64_MAX && maxfiles>1) { static int filenum=0; buffer=strdupcat(buffer,"-"); buffer=strdupcati(buffer,(uint64_t)++filenum); need_ext=true; } if (need_ext) { if (compress_level!=0) buffer=strdupcat(buffer,".gz"); } if (verbose>1) { fprintf(stderr,"%s:",buffer); if (count!=UINT64_MAX) fprintf(stderr," count=%" PRIu64,pktcount); if (bytes!=UINT64_MAX) fprintf(stderr," bytes=%" PRIu64,bytes); if (interval!=UINT64_MAX) { time_t filetime = firsttime; fprintf(stderr," time=%s",ctime(&filetime)); } else { fprintf(stderr,"\n"); } } output=trace_create_output(buffer); if (trace_is_err_output(output)) { trace_perror_output(output,"%s",buffer); free(buffer); return -1; } if (compress_level!=-1) { if (trace_config_output(output, TRACE_OPTION_OUTPUT_COMPRESS, &compress_level)==-1) { trace_perror_output(output,"Unable to set compression level"); } } if (trace_config_output(output, TRACE_OPTION_OUTPUT_COMPRESSTYPE, &compress_type) == -1) { trace_perror_output(output, "Unable to set compression type"); } trace_start_output(output); if (trace_is_err_output(output)) { trace_perror_output(output,"%s",buffer); free(buffer); return -1; } free(buffer); filescreated ++; } /* Some traces we have are padded (usually with 0x00), so * lets sort that out now and truncate them properly */ if (trace_get_capture_length(packet) > trace_get_wire_length(packet)) { trace_set_capture_length(packet,trace_get_wire_length(packet)); } if (trace_write_packet(output,packet)==-1) { trace_perror_output(output,"write_packet"); return -1; } return 1; }