source: trunk/lib/format_erf.c @ 1026

/*
 * This file is part of libtrace
 *
 * Copyright (c) 2004 The University of Waikato, Hamilton, New Zealand.
 * Authors: Daniel Lawson 
 *          Perry Lorier 
 *          
 * All rights reserved.
 *
 * This code has been developed by the University of Waikato WAND 
 * research group. For further information please see http://www.wand.net.nz/
 *
 * libtrace is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * libtrace is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with libtrace; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * $Id$
 *
 */
#define _GNU_SOURCE

#include "config.h"
#include "common.h"
#include "libtrace.h"
#include "libtrace_int.h"
#include "format_helper.h"
#include "parse_cmd.h"

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#ifdef HAVE_DAG
#include <sys/mman.h>
#endif

#ifdef WIN32
#  include <io.h>
#  include <share.h>
#  define PATH_MAX _MAX_PATH
#  define snprintf sprintf_s
#else
#  include <netdb.h>
#  ifndef PATH_MAX
#       define PATH_MAX 4096
#  endif
#  include <sys/ioctl.h>
#endif


#define COLLECTOR_PORT 3435

static struct libtrace_format_t erf;
static struct libtrace_format_t rtclient;
#ifdef HAVE_DAG
static struct libtrace_format_t dag;
#endif 

#define DATA(x) ((struct erf_format_data_t *)x->format_data)
#define DATAOUT(x) ((struct erf_format_data_out_t *)x->format_data)

#define CONNINFO DATA(libtrace)->conn_info
#define INPUT DATA(libtrace)->input
#define OUTPUT DATAOUT(libtrace)->output
#ifdef HAVE_DAG
#define DAG DATA(libtrace)->dag
#define DUCK DATA(libtrace)->duck
#endif
#define OPTIONS DATAOUT(libtrace)->options
struct erf_format_data_t {
        union {
                struct {
                        char *hostname;
                        short port;
                } rt;
        } conn_info;
        
        union {
                int fd;
                libtrace_io_t *file;
        } input;

        struct {
                enum { INDEX_UNKNOWN=0, INDEX_NONE, INDEX_EXISTS } exists;
                libtrace_io_t *index;
                off_t index_len;
        } seek;

#ifdef HAVE_DAG
        struct {
                uint32_t last_duck;     
                uint32_t duck_freq;
                uint32_t last_pkt;
                libtrace_t *dummy_duck;
        } duck;
        
        struct {
                void *buf; 
                unsigned bottom;
                unsigned top;
                unsigned diff;
                unsigned curr;
                unsigned offset;
                unsigned int dagstream;
        } dag;
#endif
};

struct erf_format_data_out_t {
        union {
                struct {
                        char *hostname;
                        short port;
                } rt;
                char *path;
        } conn_info;

        union {
                struct {
                        int level;
                        int fileflag;
                } erf;
                
        } options;
        
        union {
                int fd;
                struct rtserver_t * rtserver;
                libtrace_io_t *file;
        } output;
};

/** Structure holding status information for a packet */
typedef struct libtrace_packet_status {
        uint8_t type;
        uint8_t reserved;
        uint16_t message;
} libtrace_packet_status_t;

typedef struct erf_index_t {
        uint64_t timestamp;
        uint64_t offset; 
} erf_index_t;

#ifdef HAVE_DAG
static int dag_init_input(libtrace_t *libtrace) {
        struct stat buf;

        libtrace->format_data = (struct erf_format_data_t *)
                malloc(sizeof(struct erf_format_data_t));
        if (stat(libtrace->uridata, &buf) == -1) {
                trace_set_err(libtrace,errno,"stat(%s)",libtrace->uridata);
                return -1;
        } 

        DAG.dagstream = 0;
        
        if (S_ISCHR(buf.st_mode)) {
                /* DEVICE */
                if((INPUT.fd = dag_open(libtrace->uridata)) < 0) {
                        trace_set_err(libtrace,errno,"Cannot open DAG %s",
                                        libtrace->uridata);
                        return -1;
                }
                if((DAG.buf = (void *)dag_mmap(INPUT.fd)) == MAP_FAILED) {
                        trace_set_err(libtrace,errno,"Cannot mmap DAG %s",
                                        libtrace->uridata);
                        return -1;
                }
        } else {
                trace_set_err(libtrace,errno,"Not a valid dag device: %s",
                                libtrace->uridata);
                return -1;
        }

        DUCK.last_duck = 0;
        DUCK.duck_freq = 0;  
        DUCK.last_pkt = 0;
        DUCK.dummy_duck = NULL;
        
        return 0;
}

static int dag_config_input(libtrace_t *libtrace, trace_option_t option,
                                void *data) {
        switch(option) {
                case TRACE_META_FREQ:
                        DUCK.duck_freq = *(int *)data;
                        return 0;
                case TRACE_OPTION_SNAPLEN:
                        /* Surely we can set this?? Fall through for now*/
                
                case TRACE_OPTION_PROMISC:
                        /* DAG already operates in a promisc fashion */

                case TRACE_OPTION_FILTER:

                default:
                        trace_set_err(libtrace, TRACE_ERR_UNKNOWN_OPTION,
                                        "Unknown or unsupported option: %i",
                                        option);
                        return -1;
        }
        assert (0);
}
#endif

/* Dag erf ether packets have a 2 byte padding before the packet
 * so that the ip header is aligned on a 32 bit boundary.
 */
static int erf_get_padding(const libtrace_packet_t *packet)
{
        if (packet->trace->format->type==TRACE_FORMAT_ERF) {
                dag_record_t *erfptr = (dag_record_t *)packet->header;
                switch(erfptr->type) {
                        case TYPE_ETH:          return 2;
                        default:                return 0;
                }
        }
        else {
                switch(trace_get_link_type(packet)) {
                        case TYPE_ETH:          return 2;
                        default:                return 0;
                }
        }
}

static int erf_get_framing_length(const libtrace_packet_t *packet)
{
        return dag_record_size + erf_get_padding(packet);
}


static int erf_init_input(libtrace_t *libtrace) 
{
        libtrace->format_data = malloc(sizeof(struct erf_format_data_t));
        
        INPUT.file = 0;

        return 0; /* success */
}

static int erf_start_input(libtrace_t *libtrace)
{
        if (INPUT.file)
                return 0; /* success */

        INPUT.file = trace_open_file(libtrace);

        if (!INPUT.file)
                return -1;

        return 0; /* success */
}

/* Binary search through the index to find the closest point before
 * the packet.  Consider in future having a btree index perhaps?
 */
static int erf_fast_seek_start(libtrace_t *libtrace,uint64_t erfts)
{
        size_t max_off = DATA(libtrace)->seek.index_len/sizeof(erf_index_t);
        size_t min_off = 0;
        off_t current;
        erf_index_t record;
        do {
                current=(max_off+min_off)>>2;

                libtrace_io_seek(DATA(libtrace)->seek.index,
                                current*sizeof(record),
                                SEEK_SET);
                libtrace_io_read(DATA(libtrace)->seek.index,
                                &record,sizeof(record));
                if (record.timestamp < erfts) {
                        min_off=current;
                }
                if (record.timestamp > erfts) {
                        max_off=current;
                }
                if (record.timestamp == erfts)
                        break;
        } while(min_off<max_off);

        /* If we've passed it, seek backwards.  This loop shouldn't
         * execute more than twice.
         */
        do {
                libtrace_io_seek(DATA(libtrace)->seek.index,
                                current*sizeof(record),SEEK_SET);
                libtrace_io_read(DATA(libtrace)->seek.index,
                                &record,sizeof(record));
                current--;
        } while(record.timestamp>erfts);

        /* We've found our location in the trace, now use it. */
        libtrace_io_seek(INPUT.file,record.offset,SEEK_SET);

        return 0; /* success */
}

/* There is no index.  Seek through the entire trace from the start, nice
 * and slowly.
 */
static int erf_slow_seek_start(libtrace_t *libtrace,uint64_t erfts)
{
        if (INPUT.file) {
                libtrace_io_close(INPUT.file);
        }
        INPUT.file = trace_open_file(libtrace);
        if (!INPUT.file)
                return -1;
        return 0;
}

static int erf_seek_erf(libtrace_t *libtrace,uint64_t erfts)
{
        libtrace_packet_t *packet;
        off_t off = 0;

        if (DATA(libtrace)->seek.exists==INDEX_UNKNOWN) {
                char buffer[PATH_MAX];
                snprintf(buffer,sizeof(buffer),"%s.idx",libtrace->uridata);
                DATA(libtrace)->seek.index=libtrace_io_open(buffer,"rb");
                if (DATA(libtrace)->seek.index) {
                        DATA(libtrace)->seek.exists=INDEX_EXISTS;
                }
                else {
                        DATA(libtrace)->seek.exists=INDEX_NONE;
                }
        }

        /* If theres an index, use it to find the nearest packet that isn't
         * after the time we're looking for.  If there is no index we need
         * to seek slowly through the trace from the beginning.  Sigh.
         */
        switch(DATA(libtrace)->seek.exists) {
                case INDEX_EXISTS:
                        erf_fast_seek_start(libtrace,erfts);
                        break;
                case INDEX_NONE:
                        erf_slow_seek_start(libtrace,erfts);
                        break;
                case INDEX_UNKNOWN:
                        assert(0);
                        break;
        }

        /* Now seek forward looking for the correct timestamp */
        packet=trace_create_packet();
        do {
                trace_read_packet(libtrace,packet);
                if (trace_get_erf_timestamp(packet)==erfts)
                        break;
                off=libtrace_io_tell(INPUT.file);
        } while(trace_get_erf_timestamp(packet)<erfts);

        libtrace_io_seek(INPUT.file,off,SEEK_SET);

        return 0;
}

static int rtclient_init_input(libtrace_t *libtrace) {
        char *scan;
        libtrace->format_data = malloc(sizeof(struct erf_format_data_t));

        if (strlen(libtrace->uridata) == 0) {
                CONNINFO.rt.hostname = 
                        strdup("localhost");
                CONNINFO.rt.port = 
                        COLLECTOR_PORT;
        } else {
                if ((scan = strchr(libtrace->uridata,':')) == NULL) {
                        CONNINFO.rt.hostname = 
                                strdup(libtrace->uridata);
                        CONNINFO.rt.port =
                                COLLECTOR_PORT;
                } else {
                        CONNINFO.rt.hostname = 
                                (char *)strndup(libtrace->uridata,
                                                (scan - libtrace->uridata));
                        CONNINFO.rt.port = 
                                atoi(++scan);
                }
        }

        return 0; /* success */
}

static int rtclient_start_input(libtrace_t *libtrace)
{
        struct hostent *he;
        struct sockaddr_in remote;
        if ((he=gethostbyname(CONNINFO.rt.hostname)) == NULL) {  
                trace_set_err(libtrace,TRACE_ERR_INIT_FAILED,"failed to resolve %s",
                                CONNINFO.rt.hostname);
                return -1;
        } 
        if ((INPUT.fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                trace_set_err(libtrace,errno,"socket(AF_INET,SOCK_STREAM)");
                return -1;
        }

        remote.sin_family = AF_INET;   
        remote.sin_port = htons(CONNINFO.rt.port);
        remote.sin_addr = *((struct in_addr *)he->h_addr);
        memset(&(remote.sin_zero), 0, 8);

        if (connect(INPUT.fd, (struct sockaddr *)&remote,
                                sizeof(struct sockaddr)) == -1) {
                trace_set_err(libtrace,errno,"connect(%s)",
                                CONNINFO.rt.hostname);
                return -1;
        }
        return 0; /* success */
}

static int rtclient_pause_input(libtrace_t *libtrace)
{
        close(INPUT.fd);
        return 0; /* success */
}

static int erf_init_output(libtrace_out_t *libtrace) {
        libtrace->format_data = malloc(sizeof(struct erf_format_data_out_t));

        OPTIONS.erf.level = 0;
        OPTIONS.erf.fileflag = O_CREAT | O_WRONLY;
        OUTPUT.file = 0;

        return 0;
}

static int erf_config_output(libtrace_out_t *libtrace, trace_option_output_t option,
                void *value) {

        switch (option) {
                case TRACE_OPTION_OUTPUT_COMPRESS:
                        OPTIONS.erf.level = *(int*)value;
                        return 0;
                case TRACE_OPTION_OUTPUT_FILEFLAGS:
                        OPTIONS.erf.fileflag = *(int*)value;
                        return 0;
                default:
                        /* Unknown option */
                        trace_set_err_out(libtrace,TRACE_ERR_UNKNOWN_OPTION,
                                        "Unknown option");
                        return -1;
        }
}


#ifdef HAVE_DAG
static int dag_pause_input(libtrace_t *libtrace) {
#ifdef DAG_VERSION_2_4
        dag_stop(INPUT.fd);
#else
        if (dag_stop_stream(INPUT.fd, DAG.dagstream) < 0) {
                trace_set_err(libtrace, errno, "Could not stop DAG stream");
                return -1;
        }
        if (dag_detach_stream(INPUT.fd, DAG.dagstream) < 0) {
                trace_set_err(libtrace, errno, "Could not detach DAG stream");
                return -1;
        }
#endif
        return 0; /* success */
}

static int dag_fin_input(libtrace_t *libtrace) {
        /* dag pause input implicitly called to cleanup before this */
        
        dag_close(INPUT.fd);
        if (DUCK.dummy_duck)
                trace_destroy_dead(DUCK.dummy_duck);
        free(libtrace->format_data);
        return 0; /* success */
}
#endif

static int rtclient_fin_input(libtrace_t *libtrace) {
        free(CONNINFO.rt.hostname);
        close(INPUT.fd);
        free(libtrace->format_data);
        return 0;
}

static int erf_fin_input(libtrace_t *libtrace) {
        if (INPUT.file)
                libtrace_io_close(INPUT.file);
        free(libtrace->format_data);
        return 0;
}

static int erf_fin_output(libtrace_out_t *libtrace) {
        libtrace_io_close(OUTPUT.file);
        free(libtrace->format_data);
        return 0;
}
 
#ifdef HAVE_DAG
#ifdef DAG_VERSION_2_4
static int dag_get_duckinfo(libtrace_t *libtrace, 
                                libtrace_packet_t *packet) {
        dag_inf lt_dag_inf;
        
        if (packet->buf_control == TRACE_CTRL_EXTERNAL || 
                        !packet->buffer) {
                packet->buffer = malloc(LIBTRACE_PACKET_BUFSIZE);
                packet->buf_control = TRACE_CTRL_PACKET;
                if (!packet->buffer) {
                        trace_set_err(libtrace, errno,
                                        "Cannot allocate packet buffer");
                        return -1;
                }
        }
        
        packet->header = 0;
        packet->payload = packet->buffer;
        
        if ((ioctl(INPUT.fd, DAG_IOINF, &lt_dag_inf) < 0)) {
                trace_set_err(libtrace, errno,
                                "Error using DAG_IOINF");
                return -1;
        }
        if (!IsDUCK(&lt_dag_inf)) {
                printf("WARNING: %s does not have modern clock support - No DUCK information will be gathered\n", libtrace->uridata);
                return 0;
        }

        if ((ioctl(INPUT.fd, DAG_IOGETDUCK, (duck_inf *)packet->payload) 
                                < 0)) {
                trace_set_err(libtrace, errno, "Error using DAG_IOGETDUCK");
                return -1;
        }

        packet->type = RT_DUCK_2_4;
        if (!DUCK.dummy_duck) 
                DUCK.dummy_duck = trace_create_dead("duck:dummy");
        packet->trace = DUCK.dummy_duck;
        return sizeof(duck_inf);
}       
#else
static int dag_get_duckinfo(libtrace_t *libtrace, 
                                libtrace_packet_t *packet) {
        daginf_t lt_dag_inf;
        
        if (packet->buf_control == TRACE_CTRL_EXTERNAL || 
                        !packet->buffer) {
                packet->buffer = malloc(LIBTRACE_PACKET_BUFSIZE);
                packet->buf_control = TRACE_CTRL_PACKET;
                if (!packet->buffer) {
                        trace_set_err(libtrace, errno,
                                        "Cannot allocate packet buffer");
                        return -1;
                }
        }
        
        packet->header = 0;
        packet->payload = packet->buffer;
        
        /* No need to check if we can get DUCK or not - we're modern
         * enough */
        if ((ioctl(INPUT.fd, DAGIOCDUCK, (duckinf_t *)packet->payload) 
                                < 0)) {
                trace_set_err(libtrace, errno, "Error using DAGIOCDUCK");
                return -1;
        }

        packet->type = RT_DUCK_2_5;
        if (!DUCK.dummy_duck) 
                DUCK.dummy_duck = trace_create_dead("rt:localhost:3434");
        packet->trace = DUCK.dummy_duck;        
        return sizeof(duck_inf);
}       
#endif

static int dag_read(libtrace_t *libtrace, int block_flag) {

        if (DAG.diff != 0) 
                return DAG.diff;

        DAG.bottom = DAG.top;

        DAG.top = dag_offset(
                        INPUT.fd,
                        &(DAG.bottom),
                        block_flag);

        DAG.diff = DAG.top - DAG.bottom;

        DAG.offset = 0;
        return DAG.diff;
}

/* FIXME: dag_read_packet shouldn't update the pointers, dag_fin_packet
 * should do that.
 */
static int dag_read_packet(libtrace_t *libtrace, libtrace_packet_t *packet) {
        int numbytes;
        int size;
        struct timeval tv;
        dag_record_t *erfptr;

        if (DUCK.last_pkt - DUCK.last_duck > DUCK.duck_freq && 
                        DUCK.duck_freq != 0) {
                size = dag_get_duckinfo(libtrace, packet);
                DUCK.last_duck = DUCK.last_pkt;
                if (size != 0) {
                        return size;
                }
                /* No DUCK support, so don't waste our time anymore */
                DUCK.duck_freq = 0;
        }
        
        if (packet->buf_control == TRACE_CTRL_PACKET) {
                packet->buf_control = TRACE_CTRL_EXTERNAL;
                free(packet->buffer);
                packet->buffer = 0;
        }
        
        packet->type = RT_DATA_ERF;
        
        if ((numbytes = dag_read(libtrace,0)) < 0) 
                return numbytes;
        assert(numbytes>0);

        /*DAG always gives us whole packets */
        erfptr = (dag_record_t *) ((char *)DAG.buf + 
                        (DAG.bottom + DAG.offset));
        size = ntohs(erfptr->rlen);

        assert( size >= dag_record_size );
        assert( size < LIBTRACE_PACKET_BUFSIZE);
        
        packet->buffer = erfptr;
        packet->header = erfptr;
        if (((dag_record_t *)packet->buffer)->flags.rxerror == 1) {
                /* rxerror means the payload is corrupt - drop it
                 * by tweaking rlen */
                packet->payload = NULL;
                erfptr->rlen = htons(erf_get_framing_length(packet));
        } else {
                packet->payload = (char*)packet->buffer 
                        + erf_get_framing_length(packet);
        }

        DAG.offset += size;
        DAG.diff -= size;

        tv = trace_get_timeval(packet);
        DUCK.last_pkt = tv.tv_sec;
        
        return packet->payload ? size : erf_get_framing_length(packet);
}

static int dag_start_input(libtrace_t *libtrace) {
#ifdef DAG_VERSION_2_4
        if(dag_start(INPUT.fd) < 0) {
                trace_set_err(libtrace,errno,"Cannot start DAG %s",
                                libtrace->uridata);
                return -1;
        }
#else
        if (dag_attach_stream(INPUT.fd, DAG.dagstream, 0, 0) < 0) {
                trace_set_err(libtrace, errno, "Cannot attach DAG stream");
                return -1;
        }
        if (dag_start_stream(INPUT.fd, DAG.dagstream) < 0) {
                trace_set_err(libtrace, errno, "Cannot start DAG stream");
                return -1;
        }
#endif
        /* dags appear to have a bug where if you call dag_start after
         * calling dag_stop, and at least one packet has arrived, bad things
         * happen.  flush the memory hole 
         */
        while(dag_read(libtrace,1)!=0)
                DAG.diff=0;
        return 0;
}
#endif 

static int erf_read_packet(libtrace_t *libtrace, libtrace_packet_t *packet) {
        int numbytes;
        int size;
        void *buffer2 = packet->buffer;
        int rlen;

        if (!packet->buffer || packet->buf_control == TRACE_CTRL_EXTERNAL) {
                packet->buffer = malloc(LIBTRACE_PACKET_BUFSIZE);
                packet->buf_control = TRACE_CTRL_PACKET;
                if (!packet->buffer) {
                        trace_set_err(libtrace, errno, 
                                        "Cannot allocate memory");
                        return -1;
                }
        }

        
        
        packet->header = packet->buffer;
        packet->type = RT_DATA_ERF;

        if ((numbytes=libtrace_io_read(INPUT.file,
                                        packet->buffer,
                                        dag_record_size)) == -1) {
                trace_set_err(libtrace,errno,"read(%s)",
                                libtrace->uridata);
                return -1;
        }
        /* EOF */
        if (numbytes == 0) {
                return 0;
        }

        rlen = ntohs(((dag_record_t *)packet->buffer)->rlen);
        buffer2 = (char*)packet->buffer + dag_record_size;
        size = rlen - dag_record_size;

        assert(size < LIBTRACE_PACKET_BUFSIZE && size >= dag_record_size);

        /* Unknown/corrupt */
        assert(((dag_record_t *)packet->buffer)->type < 10);
        
        /* read in the rest of the packet */
        if ((numbytes=libtrace_io_read(INPUT.file,
                                        buffer2,
                                        size)) != size) {
                if (numbytes==-1) {
                        trace_set_err(libtrace,errno, "read(%s)", libtrace->uridata);
                        return -1;
                }
                trace_set_err(libtrace,EIO,"Truncated packet (wanted %d, got %d)", size, numbytes);
                /* Failed to read the full packet?  must be EOF */
                return -1;
        }
        if (((dag_record_t *)packet->buffer)->flags.rxerror == 1) {
                packet->payload = NULL;
        } else {
                packet->payload = (char*)packet->buffer + erf_get_framing_length(packet);
        }
        return rlen;
}

static int rtclient_read(libtrace_t *libtrace, void *buffer, size_t len) {
        int numbytes;

        while(1) {
#ifndef MSG_NOSIGNAL
#  define MSG_NOSIGNAL 0
#endif
                if ((numbytes = recv(INPUT.fd,
                                                buffer,
                                                len,
                                                MSG_NOSIGNAL)) == -1) {
                        if (errno == EINTR) {
                                /*ignore EINTR in case
                                 *a caller is using signals
                                 */
                                continue;
                        }
                        trace_set_err(libtrace,errno,"recv(%s)",
                                        libtrace->uridata);
                        return -1;
                }
                break;

        }
        return numbytes;
}

static int rtclient_read_packet(libtrace_t *libtrace, libtrace_packet_t *packet) {
        int numbytes = 0;
        char buf[RP_BUFSIZE];
        int read_required = 0;
        
        void *buffer = 0;

        if (packet->buf_control == TRACE_CTRL_EXTERNAL || !packet->buffer) {
                packet->buf_control = TRACE_CTRL_PACKET;
                packet->buffer = malloc(LIBTRACE_PACKET_BUFSIZE);
        }

        buffer = packet->buffer;
        packet->header = packet->buffer;
        
        packet->type = RT_DATA_ERF;

        
        do {
                libtrace_packet_status_t status;
                int size;
                if (tracefifo_out_available(libtrace->fifo) == 0 
                                || read_required) {
                        if ((numbytes = rtclient_read(
                                        libtrace,buf,RP_BUFSIZE))<=0) {
                                return numbytes;
                        }
                        tracefifo_write(libtrace->fifo,buf,numbytes);
                        read_required = 0;
                }
                /* Read status byte */
                if (tracefifo_out_read(libtrace->fifo,
                                &status, sizeof(uint32_t)) != sizeof(uint32_t)){
                        read_required = 1;
                        continue;
                }
                tracefifo_out_update(libtrace->fifo,sizeof(uint32_t));
                /* Read in packet size */
                if (tracefifo_out_read(libtrace->fifo,
                                &size, sizeof(uint32_t)) != sizeof(uint32_t)) {
                        tracefifo_out_reset(libtrace->fifo);
                        read_required = 1;
                        continue;
                }
                tracefifo_out_update(libtrace->fifo, sizeof(uint32_t));
                
                if (status.type == 2 /* RT_MSG */) {
                        /* Need to skip this packet as it is a message packet */
                        tracefifo_out_update(libtrace->fifo, size);
                        tracefifo_ack_update(libtrace->fifo, size + 
                                        sizeof(uint32_t) + 
                                        sizeof(libtrace_packet_status_t));
                        continue;
                }
                
                /* read in the full packet */
                if ((numbytes = tracefifo_out_read(libtrace->fifo, 
                                                buffer, size)) != size) {
                        tracefifo_out_reset(libtrace->fifo);
                        read_required = 1;
                        continue;
                }

                /* got in our whole packet, so... */
                tracefifo_out_update(libtrace->fifo,size);

                tracefifo_ack_update(libtrace->fifo,size + 
                                sizeof(uint32_t) + 
                                sizeof(libtrace_packet_status_t));

                if (((dag_record_t *)buffer)->flags.rxerror == 1) {
                        packet->payload = NULL;
                } else {
                        packet->payload = (char*)packet->buffer + erf_get_framing_length(packet);
                }
                return numbytes;
        } while(1);
}

static int erf_dump_packet(libtrace_out_t *libtrace,
                dag_record_t *erfptr, int pad, void *buffer) {
        int numbytes = 0;
        int size;

        if ((numbytes = libtrace_io_write(OUTPUT.file, erfptr, dag_record_size + pad)) != dag_record_size+pad) {
                trace_set_err_out(libtrace,errno,
                                "write(%s)",libtrace->uridata);
                return -1;
        }

        size=ntohs(erfptr->rlen)-(dag_record_size+pad);

        numbytes=libtrace_io_write(OUTPUT.file, buffer, size);
        if (numbytes != size) {
                trace_set_err_out(libtrace,errno,
                                "write(%s)",libtrace->uridata);
                return -1;
        }

        return numbytes + pad + dag_record_size;
}

static int erf_start_output(libtrace_out_t *libtrace)
{
        OUTPUT.file = trace_open_file_out(libtrace,
                        OPTIONS.erf.level,
                        OPTIONS.erf.fileflag);
        if (!OUTPUT.file) {
                return -1;
        }
        return 0;
}

static bool find_compatible_linktype(libtrace_out_t *libtrace,
                                libtrace_packet_t *packet)
{
        /* Keep trying to simplify the packet until we can find 
         * something we can do with it */
        do {
                char type=libtrace_to_erf_type(trace_get_link_type(packet));

                /* Success */
                if (type != (char)-1)
                        return true;

                if (!demote_packet(packet)) {
                        trace_set_err_out(libtrace,
                                        TRACE_ERR_NO_CONVERSION,
                                        "No erf type for packet (%i)",
                                        trace_get_link_type(packet));
                        return false;
                }

        } while(1);

        return true;
}
                
static int erf_write_packet(libtrace_out_t *libtrace, 
                libtrace_packet_t *packet) 
{
        int numbytes = 0;
        int pad = 0;
        dag_record_t *dag_hdr = (dag_record_t *)packet->header;
        void *payload = packet->payload;

        assert(OUTPUT.file);

        if (!packet->header) {
                /*trace_set_err_output(libtrace, TRACE_ERR_BAD_PACKET,
                                "Packet has no header - probably an RT packet");
                */
                return -1;
        }
        
        pad = erf_get_padding(packet);

        /* If we've had an rxerror, we have no payload to write - fix
         * rlen to be the correct length 
         */
        /* I Think this is bogus, we should somehow figure out
         * a way to write out the payload even if it is gibberish -- Perry */
        if (payload == NULL) {
                dag_hdr->rlen = htons(dag_record_size + pad);
        } 
        
        if (packet->trace->format == &erf  
#ifdef HAVE_DAG
                        || packet->trace->format == &dag 
#endif
                        ) {
                numbytes = erf_dump_packet(libtrace,
                                (dag_record_t *)packet->header,
                                pad,
                                payload
                                );
        } else {
                dag_record_t erfhdr;
                /* convert format - build up a new erf header */
                /* Timestamp */
                erfhdr.ts = bswap_host_to_le64(trace_get_erf_timestamp(packet));

                /* Flags. Can't do this */
                memset(&erfhdr.flags,1,sizeof(erfhdr.flags));
                if (trace_get_direction(packet)!=-1)
                        erfhdr.flags.iface = trace_get_direction(packet);

                if (!find_compatible_linktype(libtrace,packet))
                        return -1;

                payload=packet->payload;
                pad = erf_get_padding(packet);

                erfhdr.type = libtrace_to_erf_type(trace_get_link_type(packet));

                /* Packet length (rlen includes format overhead) */
                assert(trace_get_capture_length(packet)>0 
                                && trace_get_capture_length(packet)<=65536);
                assert(erf_get_framing_length(packet)>0 
                                && trace_get_framing_length(packet)<=65536);
                assert(
                        trace_get_capture_length(packet)+erf_get_framing_length(packet)>0
                      &&trace_get_capture_length(packet)+erf_get_framing_length(packet)<=65536);
                erfhdr.rlen = htons(trace_get_capture_length(packet) 
                        + erf_get_framing_length(packet));
                /* loss counter. Can't do this */
                erfhdr.lctr = 0;
                /* Wire length, does not include padding! */
                erfhdr.wlen = htons(trace_get_wire_length(packet));

                /* Write it out */
                numbytes = erf_dump_packet(libtrace,
                                &erfhdr,
                                pad,
                                payload);
        }
        return numbytes;
}

static libtrace_linktype_t erf_get_link_type(const libtrace_packet_t *packet) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->header;
        return erf_type_to_libtrace(erfptr->type);
}

static libtrace_direction_t erf_get_direction(const libtrace_packet_t *packet) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->header;
        return erfptr->flags.iface;
}

static libtrace_direction_t erf_set_direction(libtrace_packet_t *packet, libtrace_direction_t direction) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->header;
        erfptr->flags.iface = direction;
        return erfptr->flags.iface;
}

static uint64_t erf_get_erf_timestamp(const libtrace_packet_t *packet) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->header;
        return bswap_le_to_host64(erfptr->ts);
}

static int erf_get_capture_length(const libtrace_packet_t *packet) {
        dag_record_t *erfptr = 0;
        int caplen;
        if (packet->payload == NULL)
                return 0; 
        
        erfptr = (dag_record_t *)packet->header;
        caplen = ntohs(erfptr->rlen) - erf_get_framing_length(packet);
        if (ntohs(erfptr->wlen) < caplen)
                return ntohs(erfptr->wlen);

        return (ntohs(erfptr->rlen) - erf_get_framing_length(packet));
}

static int erf_get_wire_length(const libtrace_packet_t *packet) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->header;
        return ntohs(erfptr->wlen);
}

static size_t erf_set_capture_length(libtrace_packet_t *packet, size_t size) {
        dag_record_t *erfptr = 0;
        assert(packet);
        if(size  > trace_get_capture_length(packet)) {
                /* can't make a packet larger */
                return trace_get_capture_length(packet);
        }
        erfptr = (dag_record_t *)packet->header;
        erfptr->rlen = htons(size + erf_get_framing_length(packet));
        return trace_get_capture_length(packet);
}

static int rtclient_get_fd(const libtrace_t *libtrace) {
        return INPUT.fd;
}

#ifdef HAVE_DAG
libtrace_eventobj_t trace_event_dag(libtrace_t *trace, libtrace_packet_t *packet) {
        libtrace_eventobj_t event = {0,0,0.0,0};
        int dag_fd;
        int data;

        if (trace->format->get_fd) {
                dag_fd = trace->format->get_fd(trace);
        } else {
                dag_fd = 0;
        }
        
        data = dag_read(trace, DAGF_NONBLOCK);

        if (data > 0) {
                event.size = trace_read_packet(trace,packet);
                event.type = TRACE_EVENT_PACKET;
                return event;
        }
        event.type = TRACE_EVENT_SLEEP;
        event.seconds = 0.0001;
        return event;
}
#endif

#ifdef HAVE_DAG
static void dag_help() {
        printf("dag format module: $Revision$\n");
        printf("Supported input URIs:\n");
        printf("\tdag:/dev/dagn\n");
        printf("\n");
        printf("\te.g.: dag:/dev/dag0\n");
        printf("\n");
        printf("Supported output URIs:\n");
        printf("\tnone\n");
        printf("\n");
}
#endif

static void erf_help() {
        printf("erf format module: $Revision$\n");
        printf("Supported input URIs:\n");
        printf("\terf:/path/to/file\t(uncompressed)\n");
        printf("\terf:/path/to/file.gz\t(gzip-compressed)\n");
        printf("\terf:-\t(stdin, either compressed or not)\n");
        printf("\terf:/path/to/socket\n");
        printf("\n");
        printf("\te.g.: erf:/tmp/trace\n");
        printf("\n");
        printf("Supported output URIs:\n");
        printf("\terf:path/to/file\t(uncompressed)\n");
        printf("\terf:/path/to/file.gz\t(gzip-compressed)\n");
        printf("\terf:-\t(stdout, either compressed or not)\n");
        printf("\n");
        printf("\te.g.: erf:/tmp/trace\n");
        printf("\n");
        printf("Supported output options:\n");
        printf("\t-z\tSpecify the gzip compression, ranging from 0 (uncompressed) to 9 - defaults to 1\n");
        printf("\n");

        
}

static void rtclient_help() {
        printf("rtclient format module: $Revision$\n");
        printf("DEPRECATED - use rt module instead\n");
        printf("Supported input URIs:\n");
        printf("\trtclient:host:port\n");
        printf("\n");
        printf("\te.g.:rtclient:localhost:3435\n");
        printf("\n");
        printf("Supported output URIs:\n");
        printf("\tnone\n");
        printf("\n");
}       

static struct libtrace_format_t erf = {
        "erf",
        "$Id$",
        TRACE_FORMAT_ERF,
        erf_init_input,                 /* init_input */        
        NULL,                           /* config_input */
        erf_start_input,                /* start_input */
        NULL,                           /* pause_input */
        erf_init_output,                /* init_output */
        erf_config_output,              /* config_output */
        erf_start_output,               /* start_output */
        erf_fin_input,                  /* fin_input */
        erf_fin_output,                 /* fin_output */
        erf_read_packet,                /* read_packet */
        NULL,                           /* fin_packet */
        erf_write_packet,               /* write_packet */
        erf_get_link_type,              /* get_link_type */
        erf_get_direction,              /* get_direction */
        erf_set_direction,              /* set_direction */
        erf_get_erf_timestamp,          /* get_erf_timestamp */
        NULL,                           /* get_timeval */
        NULL,                           /* get_seconds */
        erf_seek_erf,                   /* seek_erf */
        NULL,                           /* seek_timeval */
        NULL,                           /* seek_seconds */
        erf_get_capture_length,         /* get_capture_length */
        erf_get_wire_length,            /* get_wire_length */
        erf_get_framing_length,         /* get_framing_length */
        erf_set_capture_length,         /* set_capture_length */
        NULL,                           /* get_fd */
        trace_event_trace,              /* trace_event */
        erf_help,                       /* help */
        NULL                            /* next pointer */
};

#ifdef HAVE_DAG
static struct libtrace_format_t dag = {
        "dag",
        "$Id$",
        TRACE_FORMAT_ERF,
        dag_init_input,                 /* init_input */        
        dag_config_input,               /* config_input */
        dag_start_input,                /* start_input */
        dag_pause_input,                /* pause_input */
        NULL,                           /* init_output */
        NULL,                           /* config_output */
        NULL,                           /* start_output */
        dag_fin_input,                  /* fin_input */
        NULL,                           /* fin_output */
        dag_read_packet,                /* read_packet */
        NULL,                           /* fin_packet */
        NULL,                           /* write_packet */
        erf_get_link_type,              /* get_link_type */
        erf_get_direction,              /* get_direction */
        erf_set_direction,              /* set_direction */
        erf_get_erf_timestamp,          /* get_erf_timestamp */
        NULL,                           /* get_timeval */
        NULL,                           /* get_seconds */
        NULL,                           /* seek_erf */
        NULL,                           /* seek_timeval */
        NULL,                           /* seek_seconds */
        erf_get_capture_length,         /* get_capture_length */
        erf_get_wire_length,            /* get_wire_length */
        erf_get_framing_length,         /* get_framing_length */
        erf_set_capture_length,         /* set_capture_length */
        NULL,                           /* get_fd */
        trace_event_dag,                /* trace_event */
        dag_help,                       /* help */
        NULL                            /* next pointer */
};
#endif

static struct libtrace_format_t rtclient = {
        "rtclient",
        "$Id$",
        TRACE_FORMAT_ERF,
        rtclient_init_input,            /* init_input */        
        NULL,                           /* config_input */
        rtclient_start_input,           /* start_input */
        rtclient_pause_input,           /* pause_input */
        NULL,                           /* init_output */
        NULL,                           /* config_output */
        NULL,                           /* start_output */
        rtclient_fin_input,             /* fin_input */
        NULL,                           /* fin_output */
        rtclient_read_packet,           /* read_packet */
        NULL,                           /* fin_packet */
        NULL,                           /* write_packet */
        erf_get_link_type,              /* get_link_type */
        erf_get_direction,              /* get_direction */
        erf_set_direction,              /* set_direction */
        erf_get_erf_timestamp,          /* get_erf_timestamp */
        NULL,                           /* get_timeval */
        NULL,                           /* get_seconds */
        NULL,                           /* seek_erf */
        NULL,                           /* seek_timeval */
        NULL,                           /* seek_seconds */
        erf_get_capture_length,         /* get_capture_length */
        erf_get_wire_length,            /* get_wire_length */
        erf_get_framing_length,         /* get_framing_length */
        erf_set_capture_length,         /* set_capture_length */
        rtclient_get_fd,                /* get_fd */
        trace_event_device,             /* trace_event */
        rtclient_help,                  /* help */
        NULL                            /* next pointer */
};

void erf_constructor() {
        register_format(&rtclient);
        register_format(&erf);
#ifdef HAVE_DAG
        register_format(&dag);
#endif
}