src/libstatgrab/network_stats.c

/*
 * i-scream libstatgrab
 * http://www.i-scream.org
 * Copyright (C) 2000-2004 i-scream
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307 USA
 *
 * $Id: network_stats.c,v 1.73 2005/04/25 14:12:05 tdb Exp $
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <string.h>
#include "statgrab.h"
#include "vector.h"
#include "tools.h"
#include <time.h>
#ifdef SOLARIS
#include <kstat.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <sys/sockio.h>
#include <unistd.h>
#endif
#ifdef LINUX
#include <stdio.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <ctype.h>
/* Stuff which could be defined by defining KERNEL, but 
 * that would be a bad idea, so we'll just declare it here
 */
#include <linux/version.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
typedef __uint8_t __u8;
typedef __uint16_t __u16;
typedef __uint32_t __u32;
typedef __uint64_t __u64;
#else
typedef __uint8_t u8;
typedef __uint16_t u16;
typedef __uint32_t u32;
typedef __uint64_t u64;
#endif
#include <linux/ethtool.h>
#include <linux/sockios.h>
#include <unistd.h>
#endif
#ifdef ALLBSD
#include <sys/types.h>
#include <sys/socket.h>
#include <ifaddrs.h>
#include <net/if.h>
#include <net/if_media.h>
#include <sys/ioctl.h>
#include <unistd.h>
#endif

static void network_stat_init(sg_network_io_stats *s) {
        s->interface_name = NULL;
        s->tx = 0;
        s->rx = 0;
        s->ipackets = 0;
        s->opackets = 0;
        s->ierrors = 0;
        s->oerrors = 0;
        s->collisions = 0;
}

static void network_stat_destroy(sg_network_io_stats *s) {
        free(s->interface_name);
}

VECTOR_DECLARE_STATIC(network_stats, sg_network_io_stats, 5,
                      network_stat_init, network_stat_destroy);

sg_network_io_stats *sg_get_network_io_stats(int *entries){
        int interfaces;
        sg_network_io_stats *network_stat_ptr;

#ifdef SOLARIS
        kstat_ctl_t *kc;
        kstat_t *ksp;
        kstat_named_t *knp;
#endif

#ifdef LINUX
        FILE *f;
        /* Horrible big enough, but it should be easily big enough */
        char line[8096];
        regex_t regex;
        regmatch_t line_match[9];
#endif
#ifdef ALLBSD
        struct ifaddrs *net, *net_ptr;
        struct if_data *net_data;
#endif

#ifdef ALLBSD
        if(getifaddrs(&net) != 0){
                sg_set_error_with_errno(SG_ERROR_GETIFADDRS, NULL);
                return NULL;
        }

        interfaces=0;
        
        for(net_ptr=net;net_ptr!=NULL;net_ptr=net_ptr->ifa_next){
                if(net_ptr->ifa_addr->sa_family != AF_LINK) continue;

                if (VECTOR_RESIZE(network_stats, interfaces + 1) < 0) {
                        return NULL;
                }
                network_stat_ptr=network_stats+interfaces;
                
                if (sg_update_string(&network_stat_ptr->interface_name,
                                     net_ptr->ifa_name) < 0) {
                        return NULL;
                }
                net_data=(struct if_data *)net_ptr->ifa_data;
                network_stat_ptr->rx=net_data->ifi_ibytes;
                network_stat_ptr->tx=net_data->ifi_obytes;
                network_stat_ptr->ipackets=net_data->ifi_ipackets;
                network_stat_ptr->opackets=net_data->ifi_opackets;
                network_stat_ptr->ierrors=net_data->ifi_ierrors;
                network_stat_ptr->oerrors=net_data->ifi_oerrors;
                network_stat_ptr->collisions=net_data->ifi_collisions;
                network_stat_ptr->systime=time(NULL);
                interfaces++;
        }
        freeifaddrs(net);       
#endif

#ifdef SOLARIS
        if ((kc = kstat_open()) == NULL) {
                sg_set_error(SG_ERROR_KSTAT_OPEN, NULL);
                return NULL;
        }

        interfaces=0;

        for (ksp = kc->kc_chain; ksp; ksp = ksp->ks_next) {
                if (!strcmp(ksp->ks_class, "net")) {
                        kstat_read(kc, ksp, NULL);

#ifdef SOL7
#define LRX "rbytes"
#define LTX "obytes"
#define LIPACKETS "ipackets"
#define LOPACKETS "opackets"
#define VALTYPE value.ui32
#else
#define LRX "rbytes64"
#define LTX "obytes64"
#define LIPACKETS "ipackets64"
#define LOPACKETS "opackets64"
#define VALTYPE value.ui64
#endif

                        /* Read rx */
                        if((knp=kstat_data_lookup(ksp, LRX))==NULL){
                                /* This is a network interface, but it doesn't
                                 * have the rbytes/obytes values; for instance,
                                 * the loopback devices have this behaviour
                                 * (although they do track packets in/out). */
                                /* FIXME: Show packet counts when byte counts
                                 * not available. */
                                continue;
                        }

                        /* Create new network_stats */
                        if (VECTOR_RESIZE(network_stats, interfaces + 1) < 0) {
                                return NULL;
                        }
                        network_stat_ptr=network_stats+interfaces;

                        /* Finish reading rx */
                        network_stat_ptr->rx=knp->VALTYPE;

                        /* Read tx */
                        if((knp=kstat_data_lookup(ksp, LTX))==NULL){
                                continue;
                        }
                        network_stat_ptr->tx=knp->VALTYPE;

                        /* Read ipackets */
                        if((knp=kstat_data_lookup(ksp, LIPACKETS))==NULL){
                                continue;
                        }
                        network_stat_ptr->ipackets=knp->VALTYPE;

                        /* Read opackets */
                        if((knp=kstat_data_lookup(ksp, LOPACKETS))==NULL){
                                continue;
                        }
                        network_stat_ptr->opackets=knp->VALTYPE;

                        /* Read ierrors */
                        if((knp=kstat_data_lookup(ksp, "ierrors"))==NULL){
                                continue;
                        }
                        network_stat_ptr->ierrors=knp->value.ui32;

                        /* Read oerrors */
                        if((knp=kstat_data_lookup(ksp, "oerrors"))==NULL){
                                continue;
                        }
                        network_stat_ptr->oerrors=knp->value.ui32;

                        /* Read collisions */
                        if((knp=kstat_data_lookup(ksp, "collisions"))==NULL){
                                continue;
                        }
                        network_stat_ptr->collisions=knp->value.ui32;

                        /* Read interface name */
                        if (sg_update_string(&network_stat_ptr->interface_name,
                                             ksp->ks_name) < 0) {
                                return NULL;
                        }

                        /* Store systime */
                        network_stat_ptr->systime=time(NULL);

                        interfaces++;
                }
        }
                
        kstat_close(kc);        
#endif
#ifdef LINUX
        f=fopen("/proc/net/dev", "r");
        if(f==NULL){
                sg_set_error_with_errno(SG_ERROR_OPEN, "/proc/net/dev");
                return NULL;
        }
        /* read the 2 lines.. Its the title, so we dont care :) */
        fgets(line, sizeof(line), f);
        fgets(line, sizeof(line), f);


        if((regcomp(&regex, "^ *([^:]+): *([0-9]+) +([0-9]+) +([0-9]+) +[0-9]+ +[0-9]+ +[0-9]+ +[0-9]+ +[0-9]+ +([0-9]+) +([0-9]+) +([0-9]+) +[0-9]+ +[0-9]+ +([0-9]+)", REG_EXTENDED))!=0){
                sg_set_error(SG_ERROR_PARSE, NULL);
                return NULL;
        }

        interfaces=0;

        while((fgets(line, sizeof(line), f)) != NULL){
                if((regexec(&regex, line, 9, line_match, 0))!=0){
                        continue;
                }

                if (VECTOR_RESIZE(network_stats, interfaces + 1) < 0) {
                        return NULL;
                }
                network_stat_ptr=network_stats+interfaces;

                if(network_stat_ptr->interface_name!=NULL){
                        free(network_stat_ptr->interface_name);
                }

                network_stat_ptr->interface_name=sg_get_string_match(line, &line_match[1]);
                network_stat_ptr->rx=sg_get_ll_match(line, &line_match[2]);
                network_stat_ptr->tx=sg_get_ll_match(line, &line_match[5]);
                network_stat_ptr->ipackets=sg_get_ll_match(line, &line_match[3]);
                network_stat_ptr->opackets=sg_get_ll_match(line, &line_match[6]);
                network_stat_ptr->ierrors=sg_get_ll_match(line, &line_match[4]);
                network_stat_ptr->oerrors=sg_get_ll_match(line, &line_match[7]);
                network_stat_ptr->collisions=sg_get_ll_match(line, &line_match[8]);
                network_stat_ptr->systime=time(NULL);

                interfaces++;
        }
        fclose(f);
        regfree(&regex);

#endif

#ifdef CYGWIN
        sg_set_error(SG_ERROR_UNSUPPORTED, "Cygwin");
        return NULL;
#endif
#ifdef HPUX
        sg_set_error(SG_ERROR_UNSUPPORTED, "HP-UX");
        return NULL;
#endif

        *entries=interfaces;

        return network_stats;   
}

static long long transfer_diff(long long new, long long old){
#if defined(SOL7) || defined(LINUX) || defined(FREEBSD) || defined(DFBSD) || defined(OPENBSD)
        /* 32-bit quantities, so we must explicitly deal with wraparound. */
#define MAXVAL 0x100000000LL
        if (new >= old) {
                return new - old;
        } else {
                return MAXVAL + new - old;
        }
#else
        /* 64-bit quantities, so plain subtraction works. */
        return new - old;
#endif
}

sg_network_io_stats *sg_get_network_io_stats_diff(int *entries) {
        VECTOR_DECLARE_STATIC(diff, sg_network_io_stats, 1,
                              network_stat_init, network_stat_destroy);
        sg_network_io_stats *src = NULL, *dest;
        int i, j, diff_count, new_count;

        if (network_stats == NULL) {
                /* No previous stats, so we can't calculate a difference. */
                return sg_get_network_io_stats(entries);
        }

        /* Resize the results array to match the previous stats. */
        diff_count = VECTOR_SIZE(network_stats);
        if (VECTOR_RESIZE(diff, diff_count) < 0) {
                return NULL;
        }

        /* Copy the previous stats into the result. */
        for (i = 0; i < diff_count; i++) {
                src = &network_stats[i];
                dest = &diff[i];

                if (sg_update_string(&dest->interface_name,
                                     src->interface_name) < 0) {
                        return NULL;
                }
                dest->rx = src->rx;
                dest->tx = src->tx;
                dest->ipackets = src->ipackets;
                dest->opackets = src->opackets;
                dest->ierrors = src->ierrors;
                dest->oerrors = src->oerrors;
                dest->collisions = src->collisions;
                dest->systime = src->systime;
        }

        /* Get a new set of stats. */
        if (sg_get_network_io_stats(&new_count) == NULL) {
                return NULL;
        }

        /* For each previous stat... */
        for (i = 0; i < diff_count; i++) {
                dest = &diff[i];

                /* ... find the corresponding new stat ... */
                for (j = 0; j < new_count; j++) {
                        /* Try the new stat in the same position first,
                           since that's most likely to be it. */
                        src = &network_stats[(i + j) % new_count];
                        if (strcmp(src->interface_name, dest->interface_name) == 0) {
                                break;
                        }
                }
                if (j == new_count) {
                        /* No match found. */
                        continue;
                }

                /* ... and subtract the previous stat from it to get the
                   difference. */
                dest->rx = transfer_diff(src->rx, dest->rx);
                dest->tx = transfer_diff(src->tx, dest->tx);
                dest->ipackets = transfer_diff(src->ipackets, dest->ipackets);
                dest->opackets = transfer_diff(src->opackets, dest->opackets);
                dest->ierrors = transfer_diff(src->ierrors, dest->ierrors);
                dest->oerrors = transfer_diff(src->oerrors, dest->oerrors);
                dest->collisions = transfer_diff(src->collisions, dest->collisions);
                dest->systime = src->systime - dest->systime;
        }

        *entries = diff_count;
        return diff;
}

int sg_network_io_compare_name(const void *va, const void *vb) {
        const sg_network_io_stats *a = (const sg_network_io_stats *)va;
        const sg_network_io_stats *b = (const sg_network_io_stats *)vb;

        return strcmp(a->interface_name, b->interface_name);
}

/* NETWORK INTERFACE STATS */

static void network_iface_stat_init(sg_network_iface_stats *s) {
        s->interface_name = NULL;
        s->speed = 0;
        s->duplex = SG_IFACE_DUPLEX_UNKNOWN;
}

static void network_iface_stat_destroy(sg_network_iface_stats *s) {
        free(s->interface_name);
}

sg_network_iface_stats *sg_get_network_iface_stats(int *entries){
        VECTOR_DECLARE_STATIC(network_iface_stats, sg_network_iface_stats, 5,
                              network_iface_stat_init, network_iface_stat_destroy);
        sg_network_iface_stats *network_iface_stat_ptr;
        int ifaces = 0;

#ifdef SOLARIS
        kstat_ctl_t *kc;
        kstat_t *ksp;
        kstat_named_t *knp;
        int sock;
#endif
#ifdef ALLBSD
        struct ifaddrs *net, *net_ptr;
        struct ifmediareq ifmed;
        struct ifreq ifr;
        int sock;
        int x;
#endif
#ifdef LINUX
        FILE *f;
        /* Horrible big enough, but it should be easily big enough */
        char line[8096];
        int sock;
#endif

#ifdef ALLBSD
        if(getifaddrs(&net) != 0){
                sg_set_error_with_errno(SG_ERROR_GETIFADDRS, NULL);
                return NULL;
        }

        if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == 0) return NULL;

        for(net_ptr=net; net_ptr!=NULL; net_ptr=net_ptr->ifa_next){
                if(net_ptr->ifa_addr->sa_family != AF_LINK) continue;

                if (VECTOR_RESIZE(network_iface_stats, ifaces + 1) < 0) {
                        return NULL;
                }
                network_iface_stat_ptr = network_iface_stats + ifaces;

                memset(&ifr, 0, sizeof(ifr));
                strncpy(ifr.ifr_name, net_ptr->ifa_name, sizeof(ifr.ifr_name));

                if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0){
                        continue;
                }       
                if((ifr.ifr_flags & IFF_UP) != 0){
                        network_iface_stat_ptr->up = 1;
                }else{
                        network_iface_stat_ptr->up = 0;
                }

                if (sg_update_string(&network_iface_stat_ptr->interface_name,
                                     net_ptr->ifa_name) < 0) {
                        return NULL;
                }

                network_iface_stat_ptr->speed = 0;
                network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_UNKNOWN;
                ifaces++;

                memset(&ifmed, 0, sizeof(struct ifmediareq));
                sg_strlcpy(ifmed.ifm_name, net_ptr->ifa_name, sizeof(ifmed.ifm_name));
                if(ioctl(sock, SIOCGIFMEDIA, (caddr_t)&ifmed) == -1){
                        /* Not all interfaces support the media ioctls. */
                        continue;
                }

                /* We may need to change this if we start doing wireless devices too */
                if( (ifmed.ifm_active | IFM_ETHER) != ifmed.ifm_active ){
                        /* Not a ETHER device */
                        continue;
                }

                /* Only intrested in the first 4 bits)  - Assuming only ETHER devices */
                x = ifmed.ifm_active & 0x0f;    
                switch(x){
                        /* 10 Mbit connections. Speedy :) */
                        case(IFM_10_T):
                        case(IFM_10_2):
                        case(IFM_10_5):
                        case(IFM_10_STP):
                        case(IFM_10_FL):
                                network_iface_stat_ptr->speed = 10;
                                break;
                        /* 100 Mbit conneections */
                        case(IFM_100_TX):
                        case(IFM_100_FX):
                        case(IFM_100_T4):
                        case(IFM_100_VG):
                        case(IFM_100_T2):
                                network_iface_stat_ptr->speed = 100;
                                break;
                        /* 1000 Mbit connections */
                        case(IFM_1000_SX):
                        case(IFM_1000_LX):
                        case(IFM_1000_CX):
#if defined(IFM_1000_TX) && !defined(OPENBSD)
                        case(IFM_1000_TX): /* FreeBSD 4 and others (but NOT OpenBSD)? */
#endif
#ifdef IFM_1000_FX
                        case(IFM_1000_FX): /* FreeBSD 4 */
#endif
#ifdef IFM_1000_T
                        case(IFM_1000_T): /* FreeBSD 5 */
#endif
                                network_iface_stat_ptr->speed = 1000;
                                break;
                        /* We don't know what it is */
                        default:
                                network_iface_stat_ptr->speed = 0;
                                break;
                }

                if( (ifmed.ifm_active | IFM_FDX) == ifmed.ifm_active ){
                        network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_FULL;
                }else if( (ifmed.ifm_active | IFM_HDX) == ifmed.ifm_active ){
                        network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_HALF;
                }else{
                        network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_UNKNOWN;
                }

        }       
        freeifaddrs(net);
        close(sock);
#endif

#ifdef SOLARIS
        if ((kc = kstat_open()) == NULL) {
                sg_set_error(SG_ERROR_KSTAT_OPEN, NULL);
                return NULL;
        }

        if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0) {
                sg_set_error_with_errno(SG_ERROR_SOCKET, NULL);
                return NULL;
        }

        for (ksp = kc->kc_chain; ksp; ksp = ksp->ks_next) {
                if (!strcmp(ksp->ks_class, "net")) {
                        struct ifreq ifr;

                        kstat_read(kc, ksp, NULL);

                        strncpy(ifr.ifr_name, ksp->ks_name, sizeof ifr.ifr_name);
                        if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
                                /* Not a network interface. */
                                continue;
                        }

                        if (VECTOR_RESIZE(network_iface_stats, ifaces + 1) < 0) {
                                return NULL;
                        }
                        network_iface_stat_ptr = network_iface_stats + ifaces;
                        ifaces++;

                        if (sg_update_string(&network_iface_stat_ptr->interface_name,
                                             ksp->ks_name) < 0) {
                                return NULL;
                        }

                        if ((ifr.ifr_flags & IFF_UP) != 0) {
                                network_iface_stat_ptr->up = 1;
                        } else {
                                network_iface_stat_ptr->up = 1;
                        }

                        if ((knp = kstat_data_lookup(ksp, "ifspeed")) != NULL) {
                                network_iface_stat_ptr->speed = knp->value.ui64 / (1000 * 1000);
                        } else {
                                network_iface_stat_ptr->speed = 0;
                        }

                        network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_UNKNOWN;
                        if ((knp = kstat_data_lookup(ksp, "link_duplex")) != NULL) {
                                switch (knp->value.ui32) {
                                case 1:
                                        network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_HALF;
                                        break;
                                case 2:
                                        network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_FULL;
                                        break;
                                }
                        }
                }
        }

        close(sock);
        kstat_close(kc);
#endif  
#ifdef LINUX
        f = fopen("/proc/net/dev", "r");
        if(f == NULL){
                sg_set_error_with_errno(SG_ERROR_OPEN, "/proc/net/dev");
                return NULL;
        }

        /* Setup stuff so we can do the ioctl to get the info */
        if((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0){
                sg_set_error_with_errno(SG_ERROR_SOCKET, NULL);
                return NULL;
        }

        /* Ignore first 2 lines.. Just headings */
        if((fgets(line, sizeof(line), f)) == NULL) {
                sg_set_error(SG_ERROR_PARSE, NULL);
                return NULL;
        }
        if((fgets(line, sizeof(line), f)) == NULL) {
                sg_set_error(SG_ERROR_PARSE, NULL);
                return NULL;
        }

        while((fgets(line, sizeof(line), f)) != NULL){
                char *name, *ptr;
                struct ifreq ifr;
                struct ethtool_cmd ethcmd;
                int err;

                /* Get the interface name */
                ptr = strchr(line, ':');
                if (ptr == NULL) continue;
                *ptr='\0';
                name = line;
                while(isspace(*(name))){
                        name++;
                }

                memset(&ifr, 0, sizeof ifr);
                strncpy(ifr.ifr_name, name, sizeof ifr.ifr_name);

                if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
                        continue;
                }

                /* We have a good interface to add */
                if (VECTOR_RESIZE(network_iface_stats, ifaces + 1) < 0) {
                        return NULL;
                }
                network_iface_stat_ptr = network_iface_stats + ifaces;
                
                if (sg_update_string(&network_iface_stat_ptr->interface_name,
                                     name) < 0) {
                        return NULL;
                }
                if ((ifr.ifr_flags & IFF_UP) != 0) {
                        network_iface_stat_ptr->up = 1;
                } else {
                        network_iface_stat_ptr->up = 0;
                }

                memset(&ethcmd, 0, sizeof ethcmd);
                ethcmd.cmd = ETHTOOL_GSET;
                ifr.ifr_data = (caddr_t) &ethcmd;

                err = ioctl(sock, SIOCETHTOOL, &ifr);
                if (err == 0) {
                        network_iface_stat_ptr->speed = ethcmd.speed;

                        switch (ethcmd.duplex) {
                        case DUPLEX_FULL:
                                network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_FULL;
                                break;
                        case DUPLEX_HALF:
                                network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_HALF;
                                break;
                        default:
                                network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_UNKNOWN;
                        }
                } else {
                        /* Not all interfaces support the ethtool ioctl. */
                        network_iface_stat_ptr->speed = 0;
                        network_iface_stat_ptr->duplex = SG_IFACE_DUPLEX_UNKNOWN;
                }

                ifaces++;
        }
        close(sock);
        fclose(f);
#endif
#ifdef CYGWIN
        sg_set_error(SG_ERROR_UNSUPPORTED, "Cygwin");
        return NULL;
#endif
#ifdef HPUX
        sg_set_error(SG_ERROR_UNSUPPORTED, "HP-UX");
        return NULL;
#endif

#ifdef SG_ENABLE_DEPRECATED
        network_iface_stat_ptr->dup = network_iface_stat_ptr->duplex;
#endif

        *entries = ifaces;
        return network_iface_stats; 
}

int sg_network_iface_compare_name(const void *va, const void *vb) {
        const sg_network_iface_stats *a = (const sg_network_iface_stats *)va;
        const sg_network_iface_stats *b = (const sg_network_iface_stats *)vb;

        return strcmp(a->interface_name, b->interface_name);
}

Revision:	1.74
Committed:	Wed Jul 13 09:31:54 2005 UTC (18 years, 10 months ago) by tdb
Content type:	text/plain
Branch:	MAIN
Changes since 1.73:	+17 -13 lines
Log Message:	Change the name of the duplex value from "dup" to "duplex". This will break the ABI, but we're changing the fs stats anyway. The API change is minimal, so hopefully won't affect too many people.