source: branches/libtrace2/lib/format_erf.c @ 580

/*
 * 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"

#ifdef HAVE_INTTYPES_H
#  include <inttypes.h>
#else
#  error "Can't find inttypes.h - this needs to be fixed"
#endif 

#ifdef HAVE_STDDEF_H
#  include <stddef.h>
#else
# error "Can't find stddef.h - do you define ptrdiff_t elsewhere?"
#endif
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <netdb.h>
#include <fcntl.h>
#include <getopt.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define COLLECTOR_PORT 3435

/* Catch undefined O_LARGEFILE on *BSD etc */
#ifndef O_LARGEFILE
#  define O_LARGEFILE 0
#endif 

#if HAVE_DAG
#define TYPE_80211 15
#endif

static struct libtrace_format_t erf;
static struct libtrace_format_t rtclient;
#if HAVE_DAG
static struct libtrace_format_t dag;
#endif 
static struct libtrace_format_t legacypos;
static struct libtrace_format_t legacyeth;
static struct libtrace_format_t legacyatm;

#define CONNINFO libtrace->format_data->conn_info
#define INPUT libtrace->format_data->input
#define OUTPUT libtrace->format_data->output
#if HAVE_DAG
#define DAG libtrace->format_data->dag
#endif
#define OPTIONS libtrace->format_data->options
struct libtrace_format_data_t {
        union {
                struct {
                        char *hostname;
                        short port;
                } rt;
                char *path;             
        } conn_info;
        
        union {
                int fd;
#if HAVE_ZLIB
                gzFile *file;
#else   
                //FILE  *file;
                int file;
#endif
        } input;

#if HAVE_DAG
        struct {
                void *buf; 
                unsigned bottom;
                unsigned top;
                unsigned diff;
                unsigned curr;
                unsigned offset;
        } dag;
#endif
};

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

        union {
                struct {
                        int level;
                } erf;
                
        } options;
        
        union {
                int fd;
                struct rtserver_t * rtserver;
#if HAVE_ZLIB
                gzFile *file;
#else
                //FILE *file;
                int file;
#endif
        } output;
};

#ifdef HAVE_DAG
static int dag_init_input(struct libtrace_t *libtrace) {
        struct stat buf;
        libtrace->format_data = (struct libtrace_format_data_t *)
                malloc(sizeof(struct libtrace_format_data_t));

        CONNINFO.path = libtrace->uridata;
        if (stat(CONNINFO.path,&buf) == -1) {
                perror("stat");
                return 0;
        } 
        if (S_ISCHR(buf.st_mode)) {
                // DEVICE
                libtrace->sourcetype = DEVICE;
                if((INPUT.fd = dag_open(CONNINFO.path)) < 0) {
                        fprintf(stderr,"Cannot open DAG %s: %m\n", 
                                        CONNINFO.path,errno);
                        exit(0);
                }
                if((DAG.buf = (void *)dag_mmap(INPUT.fd)) == MAP_FAILED) {
                        fprintf(stderr,"Cannot mmap DAG %s: %m\n", 
                                        CONNINFO.path,errno);
                        exit(0);
                }
                if(dag_start(INPUT.fd) < 0) {
                        fprintf(stderr,"Cannot start DAG %s: %m\n", 
                                        CONNINFO.path,errno);
                        exit(0);
                }
        } else {
                fprintf(stderr,"%s isn't a valid char device, exiting\n",
                                CONNINFO.path);
                return 0;
        }
        return 1;
}
#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 struct libtrace_packet_t *packet)
{
        switch(trace_get_link_type(packet)) {
                case TRACE_TYPE_ETH:    return 2;
                default:                return 0;
        }
}

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

static int legacyeth_get_framing_length(const struct libtrace_packet_t *packet) 
{
        return sizeof(legacy_ether_t);
}

static int legacypos_get_framing_length(const struct libtrace_packet_t *packet) 
{
        return sizeof(legacy_pos_t);
}

static int legacyatm_get_framing_length(const struct libtrace_packet_t *packet) 
{
        //return sizeof(legacy_cell_t); // 12
        return 12;
}

static int erf_init_input(struct libtrace_t *libtrace) {
        struct stat buf;
        struct sockaddr_un unix_sock;
        libtrace->format_data = (struct libtrace_format_data_t *)
                malloc(sizeof(struct libtrace_format_data_t));

        CONNINFO.path = libtrace->uridata;
        if (!strncmp(CONNINFO.path,"-",1)) {
                // STDIN
                libtrace->sourcetype = STDIN;
                if ((INPUT.file = LIBTRACE_FDOPEN(fileno(stdin), "r")) < 0) {
                        perror("libtrace_fdopen:");
                        return 0;
                }
                

        } else {
                if (stat(CONNINFO.path,&buf) == -1 ) {
                        perror("stat");
                        return 0;
                }
                if (S_ISSOCK(buf.st_mode)) {
                        libtrace->sourcetype = SOCKET;
                        if ((INPUT.fd = socket(
                                        AF_UNIX, SOCK_STREAM, 0)) == -1) {
                                perror("socket");
                                return 0;
                        }
                        unix_sock.sun_family = AF_UNIX;
                        bzero(unix_sock.sun_path,108);
                        snprintf(unix_sock.sun_path,
                                        108,"%s"
                                        ,CONNINFO.path);

                        if (connect(INPUT.fd, 
                                        (struct sockaddr *)&unix_sock,
                                        sizeof(struct sockaddr)) == -1) {
                                perror("connect (unix)");
                                return 0;
                        }
                } else { 

                        libtrace->sourcetype = TRACE;

                        // we use an FDOPEN call to reopen an FD
                        // returned from open(), so that we can set
                        // O_LARGEFILE. This gets around gzopen not
                        // letting you do this...
                        INPUT.file = LIBTRACE_FDOPEN(open(
                                                CONNINFO.path,
                                                O_LARGEFILE),"r");
                }
        }
        return 1;
}

static int rtclient_init_input(struct libtrace_t *libtrace) {
        char *scan;
        char *uridata = libtrace->uridata;
        struct hostent *he;
        struct sockaddr_in remote;
        libtrace->format_data = (struct libtrace_format_data_t *)
                malloc(sizeof(struct libtrace_format_data_t));

        libtrace->sourcetype = RT;

        if (strlen(uridata) == 0) {
                CONNINFO.rt.hostname = 
                        strdup("localhost");
                CONNINFO.rt.port = 
                        COLLECTOR_PORT;
        } else {
                if ((scan = strchr(uridata,':')) == NULL) {
                        CONNINFO.rt.hostname = 
                                strdup(uridata);
                        CONNINFO.rt.port =
                                COLLECTOR_PORT;
                } else {
                        CONNINFO.rt.hostname = 
                                (char *)strndup(uridata,
                                                (scan - uridata));
                        CONNINFO.rt.port = 
                                atoi(++scan);
                }
        }
        
        if ((he=gethostbyname(CONNINFO.rt.hostname)) == NULL) {  
                perror("gethostbyname");
                return 0;
        } 
        if ((INPUT.fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                perror("socket");
                return 0;
        }

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

        if (connect(INPUT.fd, (struct sockaddr *)&remote,
                                sizeof(struct sockaddr)) == -1) {
                perror("connect (inet)");
                return 0;
        }
        return 1;
}

static int erf_init_output(struct libtrace_out_t *libtrace) {
        char *filemode = 0;
        int fd;
        libtrace->format_data = (struct libtrace_format_data_out_t *)
                calloc(1,sizeof(struct libtrace_format_data_out_t));

        OPTIONS.erf.level = 0;
#if HAVE_ZLIB
        asprintf(&filemode,"wb%d",OPTIONS.erf.level);
#else
        // Should make append optional in libtrace 3!
        asprintf(&filemode,"a");
#endif

        if (!strncmp(libtrace->uridata,"-",1)) {
                // STDOUT
                OUTPUT.file = LIBTRACE_FDOPEN(fileno(stdout),filemode);
        }
        else {
                // TRACE
                fd = open(libtrace->uridata, O_CREAT | O_LARGEFILE | O_WRONLY | O_APPEND, S_IRUSR 
                                | S_IWUSR | S_IRGRP | S_IWGRP);
                if (fd <= 0) {
                        return 0;
                }
                OUTPUT.file = LIBTRACE_FDOPEN(fd,filemode);
                 
        }
        free(filemode); 
        return 1;
}

static int erf_config_output(struct libtrace_out_t *libtrace, int argc, char *argv[]) {
#if HAVE_ZLIB
        int opt;
        int level = OPTIONS.erf.level;
        optind = 1;


        while ((opt = getopt(argc, argv, "z:")) != EOF) {
                switch (opt) {
                        case 'z':
                                level = atoi(optarg);
                                break;
                        default:
                                printf("Bad argument to erf: %s\n", optarg);
                                // maybe spit out some help here
                                return -1;
                }
        }
        if (level != OPTIONS.erf.level) {
                if (level > 9 || level < 0) {
                        // retarded level choice
                        printf("Compression level must be between 0 and 9 inclusive - you selected %i \n", level);
                        
                } else {
                        OPTIONS.erf.level = level;
                        return gzsetparams(OUTPUT.file, level, Z_DEFAULT_STRATEGY);
                }
        }
#endif
        return 0;

}


#ifdef HAVE_DAG
static int dag_fin_input(struct libtrace_t *libtrace) {
        dag_stop(INPUT.fd);
}
#endif

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

static int rtclient_fin_input(struct libtrace_t *libtrace) {
        close(INPUT.fd);
        return 0;
}

static int erf_fin_output(struct libtrace_out_t *libtrace) {
        LIBTRACE_CLOSE(OUTPUT.file);
        free(libtrace->format_data);

        return 0;
}
 


#if HAVE_DAG
static int dag_read(struct libtrace_t *libtrace, void *buffer, size_t len) {
        int numbytes;
        static short lctr = 0;
        struct dag_record_t *erfptr = 0;
        int rlen;

        if (buffer == 0)
                buffer = malloc(len);
        
        DAG.bottom = DAG.top;
        DAG.top = dag_offset(
                        INPUT.fd,
                        &(DAG.bottom),
                        0);
        DAG.diff = DAG.top -
                DAG.bottom;

        numbytes=DAG.diff;
        DAG.offset = 0;
        return numbytes;
}
#endif

#if HAVE_DAG
static int dag_read_packet(struct libtrace_t *libtrace, struct libtrace_packet_t *packet) {
        int numbytes;
        int size;
        char buf[RP_BUFSIZE];
        dag_record_t *erfptr;
        void *buffer = packet->buffer;
        void *buffer2 = buffer;
        int rlen;
        
        if (DAG.diff == 0) {
                if ((numbytes = dag_read(libtrace,buf,RP_BUFSIZE)) <= 0) 
                        return numbytes;
        }

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

        if ( size  > LIBTRACE_PACKET_BUFSIZE) {
                assert( size < LIBTRACE_PACKET_BUFSIZE);
        }

        // have to copy it out of the memory hole at this stage:
        memcpy(packet->buffer, erfptr, size);
        
        packet->status.type = RT_DATA;
        packet->status.message = 0;
        packet->size = size;
        DAG.offset += size;
        DAG.diff -= size;

        assert(DAG.diff >= 0);

        return (size);
}
#endif

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

        // legacy - 64byte captures
        // type is TYPE_LEGACY
        if ((numbytes=LIBTRACE_READ(INPUT.file,
                                        buffer,
                                        64)) == -1) {
                perror("libtrace_read");
                return -1;
        }
        packet->status.type = RT_DATA;
        packet->status.message = 0;
        packet->size = 64;
        return 64;
}

static int erf_read_packet(struct libtrace_t *libtrace, struct libtrace_packet_t *packet) {
        int numbytes;
        int size;
        void *buffer = packet->buffer;
        void *buffer2 = buffer;
        int rlen;
        if ((numbytes=LIBTRACE_READ(INPUT.file,
                                        buffer,
                                        dag_record_size)) == -1) {
                perror("libtrace_read");
                return -1;
        }
        if (numbytes == 0) {
                return 0;
        }

        rlen = ntohs(((dag_record_t *)buffer)->rlen);
        buffer2 = buffer + dag_record_size;
        size = rlen - dag_record_size;
        assert(size < LIBTRACE_PACKET_BUFSIZE);
        
        /* If your trace is legacy, or corrupt, then this assert may fire. */
        /* turns out some older traces have fixed snaplens, which are padded
         * with 00's if the packet is smaller, so this doesn't work.  Sigh.
        assert(ntohs(((dag_record_t *)buffer)->rlen) <= 
                        ntohs(((dag_record_t*)buffer)->wlen)+erf_get_framing_length(packet));
        */
        /* Unknown/corrupt */
        assert(((dag_record_t *)buffer)->type < 10);
        
        // read in the rest of the packet
        if ((numbytes=LIBTRACE_READ(INPUT.file,
                                        buffer2,
                                        size)) != size) {
                perror("libtrace_read");
                return -1;
        }
        packet->status.type = RT_DATA;
        packet->status.message = 0;
        packet->size = rlen;
        return rlen;
}

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

        if (buffer == 0)
                buffer = malloc(len);
        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;
                        }
                        perror("recv");
                        return -1;
                }
                break;

        }
        return numbytes;
}

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

        packet->trace = libtrace;
        buffer = packet->buffer;

        
        do {
                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,
                                &packet->status, sizeof(uint32_t)) == 0) {
                        read_required = 1;
                        continue;
                }
                tracefifo_out_update(libtrace->fifo,sizeof(uint32_t));
                // Read in packet size
                if (tracefifo_out_read(libtrace->fifo,
                                &packet->size, sizeof(uint32_t)) == 0) {
                        tracefifo_out_reset(libtrace->fifo);
                        read_required = 1;
                        continue;
                }
                tracefifo_out_update(libtrace->fifo, sizeof(uint32_t));
                
                /*
                // read in the ERF header
                if ((numbytes = tracefifo_out_read(libtrace->fifo, buffer,
                                                dag_record_size)) == 0) {
                        tracefifo_out_reset(libtrace->fifo);
                        read_required = 1;
                        continue;
                }
                */
                if (packet->status.type == RT_MSG) {
                        // Need to skip this packet as it is a message packet
                        tracefifo_out_update(libtrace->fifo, packet->size);
                        tracefifo_ack_update(libtrace->fifo, packet->size + 
                                        sizeof(uint32_t) + 
                                        sizeof(libtrace_packet_status_t));
                        continue;
                }
                
                //size = ntohs(((dag_record_t *)buffer)->rlen);
                
                // read in the full packet
                if ((numbytes = tracefifo_out_read(libtrace->fifo, 
                                                buffer, packet->size)) == 0) {
                        tracefifo_out_reset(libtrace->fifo);
                        read_required = 1;
                        continue;
                }

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

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

                //packet->size = numbytes;
                return numbytes;
        } while(1);
}

static int erf_dump_packet(struct libtrace_out_t *libtrace, dag_record_t *erfptr, int pad, void *buffer, size_t size) {
        int numbytes = 0;
        if ((numbytes = LIBTRACE_WRITE(OUTPUT.file, erfptr, dag_record_size + pad)) == 0) {
                perror("libtrace_write");
                return -1;
        }

        if (buffer) {
                if ((numbytes = LIBTRACE_WRITE(OUTPUT.file, buffer, size)) == 0) {
                        perror("libtrace_write");
                        return -1;
                }
        
                return numbytes + pad + dag_record_size;
        }
        return numbytes;
}
                
static int erf_write_packet(struct libtrace_out_t *libtrace, const struct libtrace_packet_t *packet) {
        int numbytes = 0;
        dag_record_t erfhdr;
        int pad = 0;
        dag_record_t *dag_hdr = (dag_record_t *)packet->buffer;
        void *payload = (void *)trace_get_link(packet);

        pad = erf_get_padding(packet);

        /* If we've had an rxerror, we have no payload to write - fix rlen to
         * be the correct length */
        if (payload == NULL) {
                dag_hdr->rlen = htons(dag_record_size + pad);
        } 
        
        if (packet->trace->format == &erf || 
#if HAVE_DAG
                        packet->trace->format == &dag ||
#endif
                        packet->trace->format == &rtclient ) {
                numbytes = erf_dump_packet(libtrace,
                                (dag_record_t *)packet->buffer,
                                pad,
                                payload,
                                packet->size - 
                                        (dag_record_size + pad)); 
        } else {
                // convert format - build up a new erf header
                // Timestamp
                erfhdr.ts = trace_get_erf_timestamp(packet);
                // Flags. Can't do this
                memset(&erfhdr.flags,1,1);
                // Packet length (rlen includes format overhead)
                erfhdr.rlen = trace_get_capture_length(packet) + erf_get_framing_length(packet);
                // loss counter. Can't do this
                erfhdr.lctr = 0;
                // Wire length
                erfhdr.wlen = trace_get_wire_length(packet);
                
                // Write it out
                numbytes = erf_dump_packet(libtrace,
                                &erfhdr,
                                pad,
                                payload,
                                trace_get_capture_length(packet));
        }
        return numbytes;
}


static void *legacypos_get_link(const struct libtrace_packet_t *packet) {
        const void *posptr = 0;
        posptr = ((uint8_t *)packet->buffer +
                        legacypos_get_framing_length(packet));
        return (void *)posptr;
}

static libtrace_linktype_t legacypos_get_link_type(const struct libtrace_packet_t *packet) {
        return TRACE_TYPE_LEGACY_POS;
}

static void *legacyatm_get_link(const struct libtrace_packet_t *packet) {
        const void *atmptr = 0;
        atmptr = ((uint8_t *)packet->buffer +
                        legacyatm_get_framing_length(packet));
        return (void *)atmptr;
}

static libtrace_linktype_t legacyatm_get_link_type(const struct libtrace_packet_t *packet) {
        return TRACE_TYPE_LEGACY_ATM;
}

static void *legacyeth_get_link(const struct libtrace_packet_t *packet) {
        const void *ethptr = 0;
        ethptr = ((uint8_t *)packet->buffer +
                        legacyeth_get_framing_length(packet));
        return (void *)ethptr;
}

static libtrace_linktype_t legacyeth_get_link_type(const struct libtrace_packet_t *packet) {
        return TRACE_TYPE_LEGACY_ETH;
}



static void *erf_get_link(const struct libtrace_packet_t *packet) {
        const void *ethptr = 0;
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->buffer;
        
        if (erfptr->flags.rxerror == 1) {
                return NULL;
        }
        ethptr = ((uint8_t *)packet->buffer +
                        erf_get_framing_length(packet));
        return (void *)ethptr;
}

static libtrace_linktype_t erf_get_link_type(const struct libtrace_packet_t *packet) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->buffer;
        switch (erfptr->type) {
                case TYPE_LEGACY:       return TRACE_TYPE_LEGACY;
                case TYPE_ETH:          return TRACE_TYPE_ETH;
                case TYPE_ATM:          return TRACE_TYPE_ATM;
                case TYPE_80211:        return TRACE_TYPE_80211;
                default: 
                               fprintf(stderr,"Unknown erf type %02x\n",erfptr->type);
                               assert(0);
        }
        return erfptr->type;
}

static int8_t erf_get_direction(const struct libtrace_packet_t *packet) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->buffer;
        return erfptr->flags.iface;
}

static int8_t erf_set_direction(const struct libtrace_packet_t *packet, int8_t direction) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->buffer;
        erfptr->flags.iface = direction;
        return erfptr->flags.iface;
}

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

static int legacy_get_capture_length(const struct libtrace_packet_t *packet __attribute__((unused))) {
        return 64;
}

static int legacypos_get_wire_length(const struct libtrace_packet_t *packet) {
        legacy_pos_t *lpos = (legacy_pos_t *)packet->buffer;
        return ntohs(lpos->wlen);
}

static int legacyatm_get_wire_length(const struct libtrace_packet_t *packet) {
        return 53;
}

static int legacyeth_get_wire_length(const struct libtrace_packet_t *packet) {
        legacy_ether_t *leth = (legacy_ether_t *)packet->buffer;
        return ntohs(leth->wlen);
}
static int erf_get_capture_length(const struct libtrace_packet_t *packet) {
        dag_record_t *erfptr = 0;
        erfptr = (dag_record_t *)packet->buffer;
        return (ntohs(erfptr->rlen) - erf_get_framing_length(packet));
}

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

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

static int rtclient_get_fd(const struct libtrace_packet_t *packet) {
        return packet->trace->format_data->input.fd;
}

static int erf_get_fd(const struct libtrace_packet_t *packet) {
        return packet->trace->format_data->input.fd;
}

#if 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 legacypos_help() {
        printf("legacypos format module: $Revision$\n");
        printf("Supported input URIs:\n");
        printf("\tlegacypos:/path/to/file\t(uncompressed)\n");
        printf("\tlegacypos:/path/to/file.gz\t(gzip-compressed)\n");
        printf("\tlegacypos:-\t(stdin, either compressed or not)\n");
        printf("\n");
        printf("\te.g.: legacypos:/tmp/trace.gz\n");
        printf("\n");
}

static void legacyatm_help() {
        printf("legacyatm format module: $Revision$\n");
        printf("Supported input URIs:\n");
        printf("\tlegacyatm:/path/to/file\t(uncompressed)\n");
        printf("\tlegacyatm:/path/to/file.gz\t(gzip-compressed)\n");
        printf("\tlegacyatm:-\t(stdin, either compressed or not)\n");
        printf("\n");
        printf("\te.g.: legacyatm:/tmp/trace.gz\n");
        printf("\n");
}

static void legacyeth_help() {
        printf("legacyeth format module: $Revision$\n");
        printf("Supported input URIs:\n");
        printf("\tlegacyeth:/path/to/file\t(uncompressed)\n");
        printf("\tlegacyeth:/path/to/file.gz\t(gzip-compressed)\n");
        printf("\tlegacyeth:-\t(stdin, either compressed or not)\n");
        printf("\n");
        printf("\te.g.: legacyeth:/tmp/trace.gz\n");
        printf("\n");
}

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\n");
        printf("Supported input URIs:\n");
        printf("\trtclient:hostname:port\n");
        printf("\trtclient:hostname (connects on default port)\n");
        printf("\n");
        printf("\te.g.: rtclient:localhost\n");
        printf("\te.g.: rtclient:localhost:32500\n");
        printf("\n");
        printf("Supported output URIs:\n");
        printf("\trtclient: \t(will output on default port on all available IP addresses) \n");
        printf("\trtclient:hostname:port\n");
        printf("\trtclient:port\n");
        printf("\n");
        printf("\te.g.: rtclient:32500\n");
        printf("\te.g.: rtclient:\n");
        printf("\n");

}

static struct libtrace_format_t legacyatm = {
        "legacyatm",
        "$Id$",
        "legacyatm",
        erf_init_input,                 /* init_input */        
        NULL,                           /* init_output */
        NULL,                           /* config_output */
        erf_fin_input,                  /* fin_input */
        NULL,                           /* fin_output */
        legacy_read_packet,             /* read_packet */
        NULL,                           /* write_packet */
        legacyatm_get_link,             /* get_link */
        legacyatm_get_link_type,        /* get_link_type */
        NULL,                           /* get_direction */
        NULL,                           /* set_direction */
        erf_get_erf_timestamp,          /* get_erf_timestamp */
        NULL,                           /* get_timeval */
        NULL,                           /* get_seconds */
        legacy_get_capture_length,      /* get_capture_length */
        legacyatm_get_wire_length,      /* get_wire_length */
        legacyatm_get_framing_length,   /* get_framing_length */
        NULL,                           /* set_capture_length */
        NULL,                           /* get_fd */
        trace_event_trace,              /* trace_event */
        legacyatm_help                  /* help */
};

static struct libtrace_format_t legacyeth = {
        "legacyeth",
        "$Id$",
        "legacyeth",
        erf_init_input,                 /* init_input */        
        NULL,                           /* init_output */
        NULL,                           /* config_output */
        erf_fin_input,                  /* fin_input */
        NULL,                           /* fin_output */
        legacy_read_packet,             /* read_packet */
        NULL,                           /* write_packet */
        legacyeth_get_link,             /* get_link */
        legacyeth_get_link_type,        /* get_link_type */
        NULL,                           /* get_direction */
        NULL,                           /* set_direction */
        erf_get_erf_timestamp,          /* get_erf_timestamp */
        NULL,                           /* get_timeval */
        NULL,                           /* get_seconds */
        legacy_get_capture_length,      /* get_capture_length */
        legacyeth_get_wire_length,      /* get_wire_length */
        legacyeth_get_framing_length,   /* get_framing_length */
        NULL,                           /* set_capture_length */
        NULL,                           /* get_fd */
        trace_event_trace,              /* trace_event */
        legacyeth_help                  /* help */
};

static struct libtrace_format_t legacypos = {
        "legacypos",
        "$Id$",
        "legacypos",
        erf_init_input,                 /* init_input */        
        NULL,                           /* init_output */
        NULL,                           /* config_output */
        erf_fin_input,                  /* fin_input */
        NULL,                           /* fin_output */
        legacy_read_packet,             /* read_packet */
        NULL,                           /* write_packet */
        legacypos_get_link,             /* get_link */
        legacypos_get_link_type,        /* get_link_type */
        NULL,                           /* get_direction */
        NULL,                           /* set_direction */
        erf_get_erf_timestamp,          /* get_erf_timestamp */
        NULL,                           /* get_timeval */
        NULL,                           /* get_seconds */
        legacy_get_capture_length,      /* get_capture_length */
        legacypos_get_wire_length,      /* get_wire_length */
        legacypos_get_framing_length,   /* get_framing_length */
        NULL,                           /* set_capture_length */
        NULL,                           /* get_fd */
        trace_event_trace,              /* trace_event */
        legacypos_help                  /* help */
};

        
static struct libtrace_format_t erf = {
        "erf",
        "$Id$",
        "erf",
        erf_init_input,                 /* init_input */        
        erf_init_output,                /* init_output */
        erf_config_output,              /* config_output */
        erf_fin_input,                  /* fin_input */
        erf_fin_output,                 /* fin_output */
        erf_read_packet,                /* read_packet */
        erf_write_packet,               /* write_packet */
        erf_get_link,                   /* get_link */
        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_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 */
        erf_get_fd,                     /* get_fd */
        trace_event_trace,              /* trace_event */
        erf_help                        /* help */
};

#ifdef HAVE_DAG
static struct libtrace_format_t dag = {
        "dag",
        "$Id$",
        "erf",
        dag_init_input,                 /* init_input */        
        NULL,                           /* init_output */
        NULL,                           /* config_output */
        dag_fin_input,                  /* fin_input */
        NULL,                           /* fin_output */
        dag_read_packet,                /* read_packet */
        NULL,                           /* write_packet */
        erf_get_link,                   /* get_link */
        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_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 */
        dag_help                        /* help */
};
#endif

static struct libtrace_format_t rtclient = {
        "rtclient",
        "$Id$",
        "erf",
        rtclient_init_input,            /* init_input */        
        NULL,                           /* init_output */
        NULL,                           /* config_output */
        rtclient_fin_input,             /* fin_input */
        NULL,                           /* fin_output */
        rtclient_read_packet,           /* read_packet */
        NULL,                           /* write_packet */
        erf_get_link,                   /* get_link */
        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_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 */
};

void __attribute__((constructor)) erf_constructor() {
        register_format(&erf);
#ifdef HAVE_DAG
        register_format(&dag);
#endif
        register_format(&rtclient);
        register_format(&legacypos);
        register_format(&legacyeth);
        register_format(&legacyatm);
}