source: lib/format_linux.c @ d0fd73c

/*
 * 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: format_template.c,v 1.13 2005/11/22 23:38:56 dlawson Exp $
 *
 */

#include "libtrace.h"
#include "libtrace_int.h"
#include "format_helper.h"
#include "config.h"
#include "stdlib.h"

#ifdef HAVE_INTTYPES_H
#  include <inttypes.h>
#else
# error "Can't find inttypes.h"
#endif 

#include <sys/socket.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <net/if_arp.h>

#include <string.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <errno.h>

struct libtrace_format_data_t {
        int fd;
        int snaplen;
        int promisc;
};

struct libtrace_linuxnative_header {
        struct timeval ts;
        int wirelen;
        int caplen;
        struct sockaddr_ll hdr;
};

struct libtrace_linuxnative_format_data_t {
        int fd;
};

#define FORMAT(x) ((struct libtrace_format_data_t*)(x))
#define DATAOUT(x) ((struct libtrace_linuxnative_format_data_t*)((x)->format_data))

static int linuxnative_init_input(libtrace_t *libtrace) 
{
        libtrace->format_data = (struct libtrace_format_data_t *)
                malloc(sizeof(struct libtrace_format_data_t));
        FORMAT(libtrace->format_data)->fd = -1;
        FORMAT(libtrace->format_data)->promisc = 0;
        FORMAT(libtrace->format_data)->snaplen = 65536;

        return 0;
}

static int linuxnative_init_output(libtrace_out_t *libtrace)
{
        libtrace->format_data = (struct libtrace_linuxnative_format_data_t*)
                malloc(sizeof(struct libtrace_linuxnative_format_data_t));
        DATAOUT(libtrace)->fd = -1;

        return 0;
}

static int linuxnative_start_input(libtrace_t *libtrace)
{
        struct sockaddr_ll addr;
        int one = 1;
        memset(&addr,0,sizeof(addr));
        FORMAT(libtrace->format_data)->fd = 
                                socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
        if (FORMAT(libtrace->format_data)->fd==-1) {
                free(libtrace->format_data);
                return -1;
        }
        addr.sll_family = AF_PACKET;
        addr.sll_protocol = htons(ETH_P_ALL);
        if (strlen(libtrace->uridata)) {
                addr.sll_ifindex = if_nametoindex(libtrace->uridata);
                if (addr.sll_ifindex == 0) {
                        close(FORMAT(libtrace->format_data)->fd);
                        free(libtrace->format_data);
                        return -1;
                }
        }
        else {
                addr.sll_ifindex = 0;
        }
        if (bind(FORMAT(libtrace->format_data)->fd,
                                (struct sockaddr*)&addr,
                                sizeof(addr))==-1) {
                free(libtrace->format_data);
                return -1;
        }
        /* enable promisc mode when listening on an interface */
        if (addr.sll_ifindex!=0) {
                struct packet_mreq mreq;
                socklen_t socklen = sizeof(mreq);
                memset(&mreq,0,sizeof(mreq));
                mreq.mr_ifindex = addr.sll_ifindex;
                mreq.mr_type = PACKET_MR_PROMISC;
                setsockopt(FORMAT(libtrace->format_data)->fd,
                                SOL_PACKET,
                                PACKET_ADD_MEMBERSHIP,
                                &mreq,
                                socklen);
        }

        setsockopt(FORMAT(libtrace->format_data)->fd,
                        SOL_SOCKET,
                        SO_TIMESTAMP,
                        &one,
                        sizeof(one));

        return 0;
}

static int linuxnative_start_output(libtrace_out_t *libtrace)
{
        FORMAT(libtrace->format_data)->fd = 
                                socket(PF_PACKET, SOCK_RAW, 0);
        if (FORMAT(libtrace->format_data)->fd==-1) {
                free(libtrace->format_data);
                return -1;
        }

        return 0;
}

static int linuxnative_pause_input(libtrace_t *libtrace)
{
        close(FORMAT(libtrace->format_data)->fd);
        FORMAT(libtrace->format_data)->fd=-1;

        return 0;
}

static int linuxnative_fin_input(libtrace_t *libtrace) 
{
        free(libtrace->format_data);
        return 0;
}

static int linuxnative_fin_output(libtrace_out_t *libtrace)
{
        close(DATAOUT(libtrace)->fd);
        DATAOUT(libtrace)->fd=-1;
        free(libtrace->format_data);
        return 0;
}

static int linuxnative_config_input(libtrace_t *libtrace,
                trace_option_t option,
                void *data)
{
        switch(option) {
                case TRACE_OPTION_SNAPLEN:
                        FORMAT(libtrace->format_data)->snaplen=*(int*)data;
                        return 0;
                case TRACE_OPTION_PROMISC:
                        FORMAT(libtrace->format_data)->promisc=*(int*)data;
                        return 0;
                case TRACE_OPTION_FILTER:
                        /* We don't support bpf filters in any special way
                         * so return an error and let libtrace deal with
                         * emulating it
                         */
                        break;
                case TRACE_META_FREQ:
                        /* No meta-data for this format */
                        break;
                /* Avoid default: so that future options will cause a warning
                 * here to remind us to implement it, or flag it as
                 * unimplementable
                 */
        }
        trace_set_err(libtrace,TRACE_ERR_UNKNOWN_OPTION,
                        "Unknown option %i", option);
        return -1;
}

#define LIBTRACE_MIN(a,b) ((a)<(b) ? (a) : (b))

/* 20 should be enough */
#define CMSG_BUF_SIZE 20
static int linuxnative_read_packet(libtrace_t *libtrace, libtrace_packet_t *packet) 
{
        struct libtrace_linuxnative_header *hdr;
        struct msghdr msghdr;
        struct iovec iovec;
        unsigned char controlbuf[CMSG_BUF_SIZE];
        struct cmsghdr *cmsg;
        socklen_t socklen;
        int snaplen;

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

        packet->header = packet->buffer;
        packet->type = RT_DATA_LINUX_NATIVE;
        packet->payload = (char*)packet->buffer+sizeof(*hdr);

        hdr=(struct libtrace_linuxnative_header*)packet->buffer;
        socklen=sizeof(hdr->hdr);
        snaplen=LIBTRACE_MIN(
                        (int)LIBTRACE_PACKET_BUFSIZE-(int)sizeof(*hdr),
                        (int)FORMAT(libtrace->format_data)->snaplen);

        msghdr.msg_name = &hdr->hdr;
        msghdr.msg_namelen = sizeof(struct sockaddr_ll);

        msghdr.msg_iov = &iovec;
        msghdr.msg_iovlen = 1;

        msghdr.msg_control = &controlbuf;
        msghdr.msg_controllen = CMSG_BUF_SIZE;
        msghdr.msg_flags = 0;

        iovec.iov_base = (void*)packet->payload;
        iovec.iov_len = snaplen;

        hdr->wirelen = recvmsg(FORMAT(libtrace->format_data)->fd, &msghdr, 0);

        if (hdr->wirelen==-1) {
                trace_set_err(libtrace,errno,"recvmsg");
                return -1;
        }

        hdr->caplen=LIBTRACE_MIN(snaplen,hdr->wirelen);

        for (cmsg = CMSG_FIRSTHDR(&msghdr);
                        cmsg != NULL;
                        cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
                if (cmsg->cmsg_level == SOL_SOCKET
                        && cmsg->cmsg_type == SO_TIMESTAMP
                        && cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval))) {
                        memcpy(&hdr->ts, CMSG_DATA(cmsg),
                                        sizeof(struct timeval));
                        break;
                }
        }

        if (cmsg == NULL && ioctl(FORMAT(libtrace->format_data)->fd,
                                SIOCGSTAMP,&hdr->ts)==-1)
                perror("ioctl(SIOCGSTAMP)");

        return hdr->wirelen+sizeof(*hdr);
}

static int linuxnative_write_packet(libtrace_out_t *trace, 
                libtrace_packet_t *packet) 
{
        struct sockaddr_ll hdr;

        hdr.sll_family = AF_PACKET;
        hdr.sll_protocol = 0;
        hdr.sll_ifindex = if_nametoindex(trace->uridata);
        hdr.sll_hatype = 0;
        hdr.sll_pkttype = 0;
        hdr.sll_halen = 6; /* FIXME */
        memcpy(hdr.sll_addr,packet->payload,hdr.sll_halen);

        return sendto(DATAOUT(trace)->fd,
                        packet->payload,
                        trace_get_capture_length(packet),
                        0,
                        (struct sockaddr*)&hdr, sizeof(hdr));

}

static libtrace_linktype_t linuxnative_get_link_type(const struct libtrace_packet_t *packet) {
        int linktype=(((struct libtrace_linuxnative_header*)(packet->buffer))
                                ->hdr.sll_hatype);
        switch (linktype) {
                case ARPHRD_ETHER:
                        return TRACE_TYPE_ETH;
                case ARPHRD_PPP:
                        return TRACE_TYPE_NONE;
                default: /* shrug, beyond me! */
                        printf("unknown type %x\n",linktype);
                        return (libtrace_linktype_t)~0U;
        }
}

static libtrace_direction_t linuxnative_get_direction(const struct libtrace_packet_t *packet) {
        switch (((struct libtrace_linuxnative_header*)(packet->buffer))->hdr.sll_pkttype) {
                case PACKET_OUTGOING:
                        return TRACE_DIR_OUTGOING;
                default:
                        return TRACE_DIR_INCOMING;
        }
}

static struct timeval linuxnative_get_timeval(const libtrace_packet_t *packet) 
{
        return ((struct libtrace_linuxnative_header*)(packet->buffer))->ts;
}

static int linuxnative_get_capture_length(const libtrace_packet_t *packet)
{
        return ((struct libtrace_linuxnative_header*)(packet->buffer))->caplen;
}

static int linuxnative_get_wire_length(const libtrace_packet_t *packet) 
{
        return ((struct libtrace_linuxnative_header*)(packet->buffer))->wirelen;
}

static int linuxnative_get_framing_length(UNUSED 
                const libtrace_packet_t *packet) 
{
        return sizeof(struct libtrace_linuxnative_header);
}

static int linuxnative_get_fd(const libtrace_t *trace) {
        return FORMAT(trace->format_data)->fd;
}

static void linuxnative_help() {
        printf("linuxnative format module: $Revision$\n");
        printf("Supported input URIs:\n");
        printf("\tint:\n");
        printf("\n");
        printf("Supported output URIs:\n");
        printf("\tnone\n");
        printf("\n");
        return;
}
static struct libtrace_format_t linuxnative = {
        "int",
        "$Id: format_linuxnative.c,v 1.13 2005/11/22 23:38:56 dlawson Exp $",
        TRACE_FORMAT_LINUX_NATIVE,
        linuxnative_init_input,         /* init_input */
        linuxnative_config_input,       /* config_input */
        linuxnative_start_input,        /* start_input */
        linuxnative_pause_input,        /* pause_input */
        linuxnative_init_output,        /* init_output */
        NULL,                           /* config_output */
        linuxnative_start_output,       /* start_ouput */
        linuxnative_fin_input,          /* fin_input */
        linuxnative_fin_output,         /* fin_output */
        linuxnative_read_packet,        /* read_packet */
        NULL,                           /* fin_packet */
        linuxnative_write_packet,       /* write_packet */
        linuxnative_get_link_type,      /* get_link_type */
        linuxnative_get_direction,      /* get_direction */
        NULL,                           /* set_direction */
        NULL,                           /* get_erf_timestamp */
        linuxnative_get_timeval,        /* get_timeval */
        NULL,                           /* get_seconds */
        NULL,                           /* seek_erf */
        NULL,                           /* seek_timeval */
        NULL,                           /* seek_seconds */
        linuxnative_get_capture_length, /* get_capture_length */
        linuxnative_get_wire_length,    /* get_wire_length */
        linuxnative_get_framing_length, /* get_framing_length */
        NULL,                           /* set_capture_length */
        linuxnative_get_fd,             /* get_fd */
        trace_event_device,             /* trace_event */
        linuxnative_help,               /* help */
        NULL
};

void linuxnative_constructor() {
        register_format(&linuxnative);
}