source: lib/format_erf.c @ 084d95a

/*
 * 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
 *
 * $Id$
 *
 */

#include "config.h"
#include "libtrace.h"
#include "libtrace_int.h"
#include "format_helper.h"
#include "rtserver.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>

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

static struct libtrace_format_t *erf_ptr = 0;
static struct libtrace_format_t *rtclient_ptr = 0;
#if HAVE_DAG
static struct libtrace_format_t *dag_ptr = 0;
#endif 

#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;
#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;
#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

static int erf_init_input(struct libtrace_t *libtrace) {
        struct stat buf;
        struct hostent *he;
        struct sockaddr_in remote;
        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 HAVE_ZLIB
                INPUT.file = gzdopen(STDIN, "r");
#else   
                INPUT.file = stdin;
#endif

        } 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;
#if HAVE_ZLIB
                        // using gzdopen means we can set O_LARGEFILE
                        // ourselves. However, this way is messy and 
                        // we lose any error checking on "open"
                        INPUT.file = 
                                gzdopen(open(
                                        CONNINFO.path,
                                        O_LARGEFILE), "r");
#else
                        INPUT.file = 
                                fdopen(open(
                                        CONNINFO.path,
                                        O_LARGEFILE), "r");
#endif

                }
        }
        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;
        libtrace->format_data = (struct libtrace_format_data_out_t *)
                calloc(1,sizeof(struct libtrace_format_data_out_t));

        OPTIONS.erf.level = 0;
        asprintf(&filemode,"wb%d",OPTIONS.erf.level);

        if (!strncmp(libtrace->uridata,"-",1)) {
                // STDOUT
#if HAVE_ZLIB
                OUTPUT.file = gzdopen(dup(1), filemode);
#else
                OUTPUT.file = stdout;
#endif
        }
        else {
                // TRACE
#if HAVE_ZLIB
                // using gzdopen means we can set O_LARGEFILE
                // ourselves. However, this way is messy and
                // we lose any error checking on "open"
                OUTPUT.file =  gzdopen(open(
                                libtrace->uridata,
                                O_CREAT | O_LARGEFILE | O_WRONLY, 
                                S_IRUSR | S_IWUSR), filemode);
#else
                OUTPUT.file =  fdopen(open(
                                libtrace->uridata,
                                O_CREAT | O_LARGEFILE | O_WRONLY, 
                                S_IRUSR | S_IWUSR), "w");
#endif
        }
        
        return 1;
}

static int rtclient_init_output(struct libtrace_out_t *libtrace) {
        char * uridata = libtrace->uridata;
        char * scan;
        libtrace->format_data = (struct libtrace_format_data_out_t *)
                calloc(1,sizeof(struct libtrace_format_data_out_t));
        // extract conn_info from uridata
        if (strlen(uridata) == 0) {
                CONNINFO.rt.hostname = NULL;
                CONNINFO.rt.port = COLLECTOR_PORT;
        }
        else {
                if ((scan = strchr(uridata,':')) == NULL) {
                        CONNINFO.rt.hostname =
                                NULL;
                        CONNINFO.rt.port =
                                atoi(uridata);
                } else {
                        CONNINFO.rt.hostname =
                                (char *)strndup(uridata,
                                                (scan - uridata));
                        CONNINFO.rt.port =
                                atoi(++scan);
                }
        }
        
        
        OUTPUT.rtserver = 
                rtserver_create(CONNINFO.rt.hostname,
                                CONNINFO.rt.port);
        if (!OUTPUT.rtserver)
                return 0;

        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", opt);
                                // 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;

}

static int rtclient_config_output(struct libtrace_out_t *libtrace, int argc, char *argv[]) {
        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) {
#if HAVE_ZLIB
        gzclose(INPUT.file);
#else   
        fclose(INPUT.file);     
#endif
}

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

static int erf_fin_output(struct libtrace_out_t *libtrace) {
#if HAVE_ZLIB
        gzclose(OUTPUT.file);
#else
        fclose(OUTPUT.file);
#endif
}
 

static int rtclient_fin_output(struct libtrace_out_t *libtrace) {
        rtserver_destroy(OUTPUT.rtserver);
}

#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) {
                printf("%d\n",size);
                assert( size < LIBTRACE_PACKET_BUFSIZE);
        }

        // have to copy it out of the memory hole at this stage:
        memcpy(packet->buffer, erfptr, size);

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

        assert(DAG.diff >= 0);

        return (size);
}
#endif

static int erf_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 HAVE_ZLIB
        if ((numbytes=gzread(INPUT.file,
                                        buffer,
                                        dag_record_size)) == -1) {
                perror("gzread");
                return -1;
        }
#else
        if ((numbytes = read(INPUT.file, buffer, dag_record_size)) == -1) {
                perror("read");
                return -1;
        }
#endif
        if (numbytes == 0) {
                return 0;
        }
        rlen = ntohs(((dag_record_t *)buffer)->rlen);
        size = rlen - dag_record_size;
        assert(size < LIBTRACE_PACKET_BUFSIZE);
        buffer2 = buffer + dag_record_size;
        
        // read in the rest of the packet
        if ((numbytes=gzread(INPUT.file,
                                        buffer2,
                                        size)) == -1) {
                perror("gzread");
                return -1;
        }
        packet->size = rlen;
        return rlen;
}

static int rtclient_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);
        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];
        dag_record_t *erfptr = 0;
        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(int)) == 0) {
                        read_required = 1;
                        continue;
                }
                tracefifo_out_update(libtrace->fifo,sizeof(int));

                // read in the ERF header
                if ((numbytes = tracefifo_out_read(libtrace->fifo, buffer,
                                                sizeof(dag_record_t))) == 0) {
                        tracefifo_out_reset(libtrace->fifo);
                        read_required = 1;
                        continue;
                }
                size = ntohs(((dag_record_t *)buffer)->rlen);
                
                // read in the full packet
                if ((numbytes = tracefifo_out_read(libtrace->fifo, 
                                                buffer, size)) == 0) {
                        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(int));

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

static int erf_dump_packet(struct libtrace_out_t *libtrace, dag_record_t *erfptr, void *buffer, size_t size) {
        int numbytes = 0;
#if HAVE_ZLIB
        if ((numbytes = gzwrite(OUTPUT.file, erfptr, dag_record_size + 2)) == 0) {
                perror("gzwrite");
                return -1;
        }
        if ((numbytes = gzwrite(OUTPUT.file, buffer, size)) == 0) {
                perror("gzwrite");
                return -1;
        }
#else
        if ((numbytes = write(OUTPUT.file, erfptr, dag_record_size + 2)) == 0) {
                perror("write");
                return -1;
        }
        if ((numbytes = write(OUTPUT.file, buffer, size)) == 0) {
                perror("write");
                return -1;
        }
#endif
        return numbytes + sizeof(dag_record_t);

}
                
static int erf_write_packet(struct libtrace_out_t *libtrace, struct libtrace_packet_t *packet) {
        int numbytes = 0;
        dag_record_t erfhdr;
        void *payload = (void *)trace_get_link(packet);

        if (packet->trace->format == erf_ptr || 
#if HAVE_DAG
                        packet->trace->format == dag_ptr ||
#endif
                        packet->trace->format == rtclient_ptr ) {
                numbytes = erf_dump_packet(libtrace,
                                (dag_record_t *)packet->buffer,
                                payload,
                                packet->size - 
                                        (dag_record_size + 2)); 
        } else {
                // convert format - build up a new erf header
                // Timestamp
                erfhdr.ts = trace_get_erf_timestamp(packet);
                // Link type
                switch(trace_get_link_type(packet)) {
                case TRACE_TYPE_ETH:
                        erfhdr.type=TYPE_ETH; break;
                case TRACE_TYPE_ATM:
                        erfhdr.type=TYPE_ATM; break;
                default:
                        erfhdr.type=0; 
                }
                // Flags. Can't do this
                memset(&erfhdr.flags,1,1);
                // Packet length
                erfhdr.rlen = trace_get_capture_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,
                                payload,
                                erfhdr.rlen);
        }
        return numbytes;
}

static int rtclient_write_packet(struct libtrace_out_t *libtrace, struct libtrace_packet_t *packet) {
        int numbytes = 0;
        int size;
        int intsize = sizeof(int);
        char buf[RP_BUFSIZE];
        void *buffer = &buf[intsize];
        int write_required = 0;
        
        do {
                if (rtserver_checklisten(libtrace->format_data->output.rtserver) < 0)
                        return -1;

                assert(libtrace->fifo);
                if (tracefifo_out_available(libtrace->fifo) == 0 || write_required) {
                        // Packet added to fifo
                        if ((numbytes = tracefifo_write(libtrace->fifo, packet->buffer, packet->size)) == 0) {
                                // some error with the fifo
                                perror("tracefifo_write");
                                return -1;
                        }
                        write_required = 0;
                }

                // Read from fifo and add protocol header
                if ((numbytes = tracefifo_out_read(libtrace->fifo, buffer, sizeof(dag_record_t))) == 0) {
                        // failure reading in from fifo
                        tracefifo_out_reset(libtrace->fifo);
                        write_required = 1;
                        continue;
                }
                size = ntohs(((dag_record_t *)buffer)->rlen);
                assert(size < LIBTRACE_PACKET_BUFSIZE);
                if ((numbytes = tracefifo_out_read(libtrace->fifo, buffer, size)) == 0) {
                       // failure reading in from fifo
                       tracefifo_out_reset(libtrace->fifo);
                       write_required = 1;
                       continue;
                }
                // Sort out the protocol header
                memcpy(buf, &packet->status, intsize);

                if ((numbytes = rtserver_sendclients(libtrace->format_data->output.rtserver, buf, size + sizeof(int))) < 0) {
                        write_required = 0;
                        continue;
                }


                tracefifo_out_update(libtrace->fifo, size);
                tracefifo_ack_update(libtrace->fifo, size);
                return numbytes;
        } while(1);
}

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 +
                        dag_record_size + 2);
        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_ETH: return TRACE_TYPE_ETH;
                case TYPE_ATM: return TRACE_TYPE_ATM;
                default: 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 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);
}

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 > packet->size) {
                // can't make a packet larger
                return packet->size;
        }
        erfptr = (dag_record_t *)packet->buffer;
        erfptr->rlen = ntohs(size + sizeof(dag_record_t));
        packet->size = size + sizeof(dag_record_t);
        return packet->size;
}

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

static int erf_get_fd(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 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 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_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_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 */        
        rtclient_init_output,           /* init_output */
        rtclient_config_output,         /* config_output */
        rtclient_fin_input,             /* fin_input */
        rtclient_fin_output,            /* fin_output */
        rtclient_read_packet,           /* read_packet */
        rtclient_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_set_capture_length,         /* set_capture_length */
        rtclient_get_fd,                /* get_fd */
        trace_event_device,             /* trace_event */
        rtclient_help                   /* help */
};

void __attribute__((constructor)) erf_constructor() {
        erf_ptr = &erf;
        register_format(erf_ptr);
#ifdef HAVE_DAG
        dag_ptr = &dag;
        register_format(dag_ptr);
#endif
        rtclient_ptr = &rtclient;
        register_format(rtclient_ptr);
}