#include "sigar.h"
#include "sigar_private.h"
#include "sigar_util.h"
#include "sigar_os.h"

#ifdef DARWIN
#include <mach/mach_init.h>
#include <mach/message.h>
#include <mach/kern_return.h>
#include <mach/mach_host.h>
#include <mach/mach_traps.h>
#include <mach/mach_port.h>
#include <mach/task.h>
#include <mach/vm_map.h>
#include <mach/shared_memory_server.h>
#else
#include <sys/dkstat.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/user.h>
#include <sys/vmmeter.h>
#include <fcntl.h>
#endif

#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/sockio.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <netinet/in.h>

#include <dirent.h>
#include <errno.h>

#define NMIB(mib) (sizeof(mib)/sizeof(mib[0]))

#if defined (__FreeBSD__) && (__FreeBSD_version >= 500013)
#define SIGAR_FREEBSD5
#endif

#ifdef SIGAR_FREEBSD5

#define KI_PID  ki_pid
#define KI_PPID ki_ppid
#define KI_PRI  ki_pri.pri_user
#define KI_NICE ki_nice
#define KI_COMM ki_comm
#define KI_STAT ki_stat
#define KI_UID  ki_ruid
#define KI_GID  ki_rgid
#define KI_EUID ki_svuid
#define KI_EGID ki_svgid
#define KI_SIZE ki_size
#define KI_RSS  ki_rssize
#define KI_TSZ  ki_tsize
#define KI_DSZ  ki_dsize
#define KI_SSZ  ki_ssize
#define KI_FLAG ki_flag
#define KI_START ki_start
#else

#define KI_PID  kp_proc.p_pid
#define KI_PPID kp_eproc.e_ppid
#define KI_PRI  kp_proc.p_priority
#define KI_NICE kp_proc.p_nice
#define KI_COMM kp_proc.p_comm
#define KI_STAT kp_proc.p_stat
#define KI_UID  kp_eproc.e_pcred.p_ruid
#define KI_GID  kp_eproc.e_pcred.p_rgid
#define KI_EUID kp_eproc.e_pcred.p_svuid
#define KI_EGID kp_eproc.e_pcred.p_svgid
#define KI_SIZE XXX
#define KI_RSS  kp_eproc.e_vm.vm_rssize
#define KI_TSZ  kp_eproc.e_vm.vm_tsize
#define KI_DSZ  kp_eproc.e_vm.vm_dsize
#define KI_SSZ  kp_eproc.e_vm.vm_ssize
#define KI_FLAG kp_eproc.e_flag
#define KI_START kp_proc.p_starttime
#endif

#ifndef DARWIN

#define PROCFS_STATUS(status) \
    ((((status) != SIGAR_OK) && !sigar->proc_mounted) ? \
     SIGAR_ENOTIMPL : status)

static int get_koffsets(sigar_t *sigar)
{
    int i;
    struct nlist klist[] = {
        { "_cp_time" },
        { "_cnt" },
        { NULL }
    };

    if (!sigar->kmem) {
        return SIGAR_EPERM_KMEM;
    }

    kvm_nlist(sigar->kmem, klist);
    if (klist[0].n_type == 0) {
        return errno;
    }

    for (i=0; i<KOFFSET_MAX; i++) {
        sigar->koffsets[i] = klist[i].n_value;
    }

    return SIGAR_OK;
}

static int kread(sigar_t *sigar, void *data, int size, long offset)
{
    if (!sigar->kmem) {
        return SIGAR_EPERM_KMEM;
    }

    if (kvm_read(sigar->kmem, offset, data, size) != size) {
        return errno;
    }

    return SIGAR_OK;
}
#endif

int sigar_os_open(sigar_t **sigar)
{
    int mib[2];
    int ncpu;
    size_t len;
    struct timeval boottime;
#ifndef DARWIN
    struct stat sb;
#endif

    len = sizeof(ncpu);
    mib[0] = CTL_HW;
    mib[1] = HW_NCPU;
    if (sysctl(mib, NMIB(mib), &ncpu,  &len, NULL, 0) < 0) {
        return errno;
    }

    len = sizeof(boottime);
    mib[0] = CTL_KERN;
    mib[1] = KERN_BOOTTIME;
    if (sysctl(mib, NMIB(mib), &boottime, &len, NULL, 0) < 0) {
        return errno;
    }

    *sigar = malloc(sizeof(**sigar));

#ifdef DARWIN
    (*sigar)->mach_port = mach_host_self();
#else
    (*sigar)->kmem = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
    if (stat("/proc/curproc", &sb) < 0) {
        (*sigar)->proc_mounted = 0;
    }
    else {
        (*sigar)->proc_mounted = 1;
    }
#endif

#ifndef DARWIN
    get_koffsets(*sigar);
#endif

    (*sigar)->ncpu = ncpu;

    (*sigar)->boot_time = boottime.tv_sec; /* XXX seems off a bit */

    (*sigar)->pagesize = getpagesize();
#ifdef __FreeBSD__
    (*sigar)->ticks = 100; /* sysconf(_SC_CLK_TCK) == 128 !? */
#endif
    (*sigar)->last_pid = -1;

    (*sigar)->pinfo = NULL;

    return SIGAR_OK;
}

int sigar_os_close(sigar_t *sigar)
{
    if (sigar->pinfo) {
        free(sigar->pinfo);
    }
    free(sigar);
    return SIGAR_OK;
}

char *sigar_os_error_string(sigar_t *sigar, int err)
{
    switch (err) {
      case SIGAR_EPERM_KMEM:
        return "Failed to open /dev/kmem for reading";
      case SIGAR_EPROC_NOENT:
        return "/proc filesystem is not mounted";
      default:
        return NULL;
    }
}

int sigar_mem_get(sigar_t *sigar, sigar_mem_t *mem)
{
#ifdef DARWIN
    vm_statistics_data_t vmstat;
    kern_return_t status;
    mach_msg_type_number_t count = sizeof(vmstat) / sizeof(integer_t);
#endif
    int mib[2];
    int value;
    size_t len = sizeof(value);

    mib[0] = CTL_HW;

    mib[1] = HW_PAGESIZE;
    if (sysctl(mib, NMIB(mib), &sigar->pagesize, &len, NULL, 0) < 0) {
        return errno;
    }

    mib[1] = HW_PHYSMEM;
    if (sysctl(mib, NMIB(mib), &value, &len, NULL, 0) < 0) {
        return errno;
    }

    mem->total = value;
#ifdef DARWIN
    status = host_statistics(sigar->mach_port, HOST_VM_INFO,
                             (host_info_t)&vmstat, &count);

    if (status != KERN_SUCCESS) {
        return errno;
    }

    mem->free = vmstat.free_count * sigar->pagesize;
#else
    len = sizeof(value);
    if (sysctlbyname("vm.stats.vm.v_free_count",
                     &value, &len, NULL, 0) == -1)
    {
        mem->free = 0; /*XXX*/
    }
    else {
        mem->free = value * sigar->pagesize;
    }
#endif
    /*
    int status;
    struct vmmeter vmem;

    status = kread(sigar, &vmem, sizeof(vmem),
                   sigar->koffsets[KOFFSET_VMMETER]);

    if (status != SIGAR_OK) {
        return status;
    }    

    mem->total = vmem.v_page_count * sigar->pagesize;
    mem->free  = vmem.v_free_count * sigar->pagesize;
    */

    mem->used = mem->total - mem->free;
    mem->shared = SIGAR_FIELD_NOTIMPL; /*XXX*/

    sigar_mem_calc_ram(sigar, mem);

    mem->actual_free = mem->free;
    mem->actual_used = mem->used;

    return SIGAR_OK;
}

#define SIGAR_FS_BLOCKS_TO_BYTES(buf, f) \
    ((buf.f * (buf.f_bsize / 512)) >> 1)

#define VM_DIR "/private/var/vm"
#define SWAPFILE "swapfile"

#define NL_SWAPBLIST 0
#define NL_SWDEVT 1
#define NL_NSWDEV 2
#define NL_DMMAX 3

#define SWI_MAXMIB 3

#ifdef SIGAR_FREEBSD5
/* code in this function is based on FreeBSD 5.3 kvm_getswapinfo.c */
static int getswapinfo_sysctl(struct kvm_swap *swap_ary,
                              int swap_max) 
{
    int ti, ttl;
    size_t mibi, len, size;
    int soid[SWI_MAXMIB];
    struct xswdev xsd;
    struct kvm_swap tot;
    int unswdev, dmmax;

    /* XXX this can be optimized by using os_open */
    size = sizeof(dmmax);
    if (sysctlbyname("vm.dmmax", &dmmax, &size, NULL, 0) == -1) {
        return errno;
    }

    mibi = SWI_MAXMIB - 1;
    if (sysctlnametomib("vm.swap_info", soid, &mibi) == -1) {
        return errno;
    }

    bzero(&tot, sizeof(tot));
    for (unswdev = 0;; unswdev++) {
        soid[mibi] = unswdev;
        len = sizeof(xsd);
        if (sysctl(soid, mibi + 1, &xsd, &len, NULL, 0) == -1) {
            if (errno == ENOENT) {
                break;
            }
            return errno;
        }
#if 0
        if (len != sizeof(xsd)) {
            _kvm_err(kd, kd->program, "struct xswdev has unexpected "
                     "size;  kernel and libkvm out of sync?");
            return -1;
        }
        if (xsd.xsw_version != XSWDEV_VERSION) {
            _kvm_err(kd, kd->program, "struct xswdev version "
                     "mismatch; kernel and libkvm out of sync?");
            return -1;
        }
#endif
        ttl = xsd.xsw_nblks - dmmax;
        if (unswdev < swap_max - 1) {
            bzero(&swap_ary[unswdev], sizeof(swap_ary[unswdev]));
            swap_ary[unswdev].ksw_total = ttl;
            swap_ary[unswdev].ksw_used = xsd.xsw_used;
            swap_ary[unswdev].ksw_flags = xsd.xsw_flags;
        }
        tot.ksw_total += ttl;
        tot.ksw_used += xsd.xsw_used;
    }

    ti = unswdev;
    if (ti >= swap_max) {
        ti = swap_max - 1;
    }
    if (ti >= 0) {
        swap_ary[ti] = tot;
    }

    return SIGAR_OK;
}
#else
#define getswapinfo_sysctl(swap_ary, swap_max) SIGAR_ENOTIMPL
#endif

int sigar_swap_get(sigar_t *sigar, sigar_swap_t *swap)
{
#ifdef DARWIN
    DIR *dirp;
    struct dirent *ent;
    char swapfile[SSTRLEN(VM_DIR) + SSTRLEN("/") + SSTRLEN(SWAPFILE) + 12];
    struct stat swapstat;
    struct statfs vmfs;

    swap->used = swap->total = swap->free = 0;

    if (!(dirp = opendir(VM_DIR))) {
        return errno;
    }

    /* looking for "swapfile0", "swapfile1", etc. */
    while ((ent = readdir(dirp))) {
        char *ptr = swapfile;

        if ((ent->d_namlen < SSTRLEN(SWAPFILE)+1) || /* n/a, see comment above */
            (ent->d_namlen > SSTRLEN(SWAPFILE)+11)) /* ensure no overflow */
        {
            continue;
        }

        if (!strnEQ(ent->d_name, SWAPFILE, SSTRLEN(SWAPFILE))) {
            continue;
        }
        
        /* sprintf(swapfile, "%s/%s", VM_DIR, ent->d_name) */

        memcpy(ptr, VM_DIR, SSTRLEN(VM_DIR));
        ptr += SSTRLEN(VM_DIR);

        *ptr++ = '/';

        memcpy(ptr, ent->d_name, ent->d_namlen+1);

        if (stat(swapfile, &swapstat) < 0) {
            continue;
        }

        swap->used += swapstat.st_size;
    }

    closedir(dirp);

    if (statfs(VM_DIR, &vmfs) < 0) {
        return errno;
    }

    swap->total = SIGAR_FS_BLOCKS_TO_BYTES(vmfs, f_bfree) + swap->used;

    swap->free = swap->total - swap->used;

#else
    struct kvm_swap kswap[1];

    if (getswapinfo_sysctl(kswap, 1) != SIGAR_OK) {
        if (!sigar->kmem) {
            return SIGAR_EPERM_KMEM;
        }

        if (kvm_getswapinfo(sigar->kmem, kswap, 1, 0) < 0) {
            return errno;
        }
    }

    if (kswap[0].ksw_total == 0) {
        swap->total = 0;
        swap->used  = 0;
        swap->free  = 0;
        return SIGAR_OK;
    }

    swap->total = kswap[0].ksw_total * sigar->pagesize;
    swap->used  = kswap[0].ksw_used * sigar->pagesize;
    swap->free  = swap->total - swap->used;
#endif

    return SIGAR_OK;
}

int sigar_cpu_get(sigar_t *sigar, sigar_cpu_t *cpu)
{
#ifdef DARWIN
    kern_return_t status;
    mach_msg_type_number_t count = HOST_CPU_LOAD_INFO_COUNT;
    host_cpu_load_info_data_t cpuload;

    status = host_statistics(sigar->mach_port, HOST_CPU_LOAD_INFO,
                             (host_info_t)&cpuload, &count);

    if (status != KERN_SUCCESS) {
        return errno;
    }

    cpu->user = cpuload.cpu_ticks[CPU_STATE_USER];
    cpu->sys  = cpuload.cpu_ticks[CPU_STATE_SYSTEM];
    cpu->idle = cpuload.cpu_ticks[CPU_STATE_IDLE];
    cpu->nice = cpuload.cpu_ticks[CPU_STATE_NICE];
    cpu->wait = 0; /*N/A*/
    cpu->total = cpu->user + cpu->nice + cpu->sys + cpu->idle;

#else
    int status;
    long cp_time[CPUSTATES];
    size_t size = sizeof(cp_time);

    /* try sysctl first, does not require /dev/kmem perms */
    if (sysctlbyname("kern.cp_time", &cp_time, &size, NULL, 0) == -1) {
        status = kread(sigar, &cp_time, sizeof(cp_time),
                       sigar->koffsets[KOFFSET_CPUINFO]);
    }
    else {
        status = SIGAR_OK;
    }

    if (status != SIGAR_OK) {
        return status;
    }

    cpu->user = SIGAR_TICK2SEC(cp_time[CP_USER]);
    cpu->nice = SIGAR_TICK2SEC(cp_time[CP_NICE]);
    cpu->sys  = SIGAR_TICK2SEC(cp_time[CP_SYS] + cp_time[CP_INTR]);
    cpu->idle = SIGAR_TICK2SEC(cp_time[CP_IDLE]);
    cpu->wait = 0; /*N/A*/
    cpu->total = cpu->user + cpu->nice + cpu->sys + cpu->idle;
#endif

    return SIGAR_OK;
}

int sigar_cpu_list_get(sigar_t *sigar, sigar_cpu_list_t *cpulist)
{
    sigar_cpu_t *cpu;

    sigar_cpu_list_create(cpulist);

    /* XXX multi cpu */
    cpu = &cpulist->data[cpulist->number++];

    return sigar_cpu_get(sigar, cpu);
}

int sigar_uptime_get(sigar_t *sigar,
                     sigar_uptime_t *uptime)
{
    uptime->uptime   = time(NULL) - sigar->boot_time;

    return SIGAR_OK;
}

int sigar_loadavg_get(sigar_t *sigar,
                      sigar_loadavg_t *loadavg)
{
    getloadavg(loadavg->loadavg, 3);

    return SIGAR_OK;
}

#ifndef KERN_PROC_PROC
/* freebsd 4.x */
#define KERN_PROC_PROC KERN_PROC_ALL
#endif

int sigar_proc_list_get(sigar_t *sigar,
                        sigar_proc_list_t *proclist)
{
#if 1 /*def DARWIN*/ /* XXX dont think this works on freebsd 4.x */
    int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PROC, 0 };
    int i, num;
    size_t len;
    struct kinfo_proc *proc;

    if (sysctl(mib, NMIB(mib), NULL, &len, NULL, 0) < 0) {
        return errno;
    }

    proc = malloc(len);

    if (sysctl(mib, NMIB(mib), proc, &len, NULL, 0) < 0) {
        free(proc);
        return errno;
    }

    num = len/sizeof(*proc);
    sigar_proc_list_create(proclist);

    for (i=0; i<num; i++) {
        if (proc[i].KI_FLAG & P_SYSTEM) {
            continue;
        }
        SIGAR_PROC_LIST_GROW(proclist);
        proclist->data[proclist->number++] = proc[i].KI_PID;
    }

    free(proc);

    return SIGAR_OK;
#else
    int i, num;
    struct kinfo_proc *proc;

    if (!sigar->kmem) {
        return SIGAR_EPERM_KMEM;
    }

    proc = kvm_getprocs(sigar->kmem, KERN_PROC_PROC, 0, &num);
    
    sigar_proc_list_create(proclist);

    for (i=0; i<num; i++) {
        if (proc[i].KI_FLAG & P_SYSTEM) {
            continue;
        }
        SIGAR_PROC_LIST_GROW(proclist);
        proclist->data[proclist->number++] = proc[i].KI_PID;
    }
#endif

    return SIGAR_OK;
}

int sigar_proc_stat_get(sigar_t *sigar,
                        sigar_proc_stat_t *procstat)
{
    int status = /* XXX optimize */
        sigar_proc_count(sigar, &procstat->total);

    return status;
}

static int sigar_get_pinfo(sigar_t *sigar, sigar_pid_t pid)
{
    int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, 0 };
    size_t len = sizeof(*sigar->pinfo);
    time_t timenow = time(NULL);
    mib[3] = pid;

    if (sigar->pinfo == NULL) {
        sigar->pinfo = malloc(len);
    }

    if (sigar->last_pid == pid) {
        if ((timenow - sigar->last_getprocs) < SIGAR_LAST_PROC_EXPIRE) {
            return SIGAR_OK;
        }
    }

    sigar->last_pid = pid;
    sigar->last_getprocs = timenow;

    if (sysctl(mib, NMIB(mib), sigar->pinfo, &len, NULL, 0) < 0) {
        return errno;
    }

    return SIGAR_OK;
}

#ifdef DARWIN
/* this insanity if dervied from Apple's port of 'top' and libgtop patch */
#define SHARED_TABLE_SIZE   137
#define TEXT_SEGMENT_START  (GLOBAL_SHARED_TEXT_SEGMENT)
#define DATA_SEGMENT_END    (GLOBAL_SHARED_DATA_SEGMENT + SHARED_DATA_REGION_SIZE)

typedef struct shared_info shared_table[SHARED_TABLE_SIZE];
typedef struct shared_info shared_info;

struct shared_info {
    unsigned obj_id;
    unsigned share_mode;
    unsigned page_count;
    unsigned ref_count;
    unsigned task_ref_count;
    vm_size_t size;
    shared_info *next;
};

static void shared_table_free(shared_table table)
{
    int i;

    for (i=0; i<SHARED_TABLE_SIZE; i++) {
        shared_info *info = table[i].next;

        while (info) {
            shared_info *next = info->next;
            free(info);
            info = next;
        }
    }
}

static void shared_table_register(shared_table table,
                                  vm_region_top_info_data_t *top,
                                  vm_size_t size)
{
    shared_info *info, *last;

    info = last = &table[top->obj_id % SHARED_TABLE_SIZE];
    while (info) {
        if (info->obj_id == top->obj_id) {
            info->task_ref_count++;
            return;
        }
        last = info;
        info = info->next;
    }

    info = malloc(sizeof(shared_info));
    if (info) {
        info->obj_id = top->obj_id;
        info->share_mode = top->share_mode;
        info->page_count = top->shared_pages_resident;
        info->ref_count = top->ref_count;
        info->task_ref_count = 1;
        info->size = size;
        info->next = NULL;
        last->next = info;
    }
}

#endif /* DARWIN */

int sigar_proc_mem_get(sigar_t *sigar, sigar_pid_t pid,
                       sigar_proc_mem_t *procmem)
{
#ifdef DARWIN
    mach_port_t task, self = mach_task_self();
    kern_return_t status;
    task_basic_info_data_t info;
    task_events_info_data_t events;
    mach_msg_type_number_t count;
    vm_size_t vsize, resident, private, vprivate, shared;
    shared_table table;
    vm_address_t address = 0;
    int i, split = 0;

    status = task_for_pid(self, pid, &task);

    if (status != KERN_SUCCESS) {
        return errno;
    }

    count = TASK_BASIC_INFO_COUNT;
    status = task_info(task, TASK_BASIC_INFO, (task_info_t)&info, &count);
    if (status != KERN_SUCCESS) {
        return errno;
    }

    vsize = info.virtual_size;
    resident = info.resident_size;

    count = TASK_EVENTS_INFO_COUNT;
    status = task_info(task, TASK_EVENTS_INFO, (task_info_t)&events, &count);
    if (status == KERN_SUCCESS) {
        procmem->page_faults = events.faults;
    }
    else {
        procmem->page_faults = SIGAR_FIELD_NOTIMPL;
    }

    procmem->minor_faults = SIGAR_FIELD_NOTIMPL;
    procmem->major_faults = SIGAR_FIELD_NOTIMPL;

    private = vprivate = shared = 0;
    memset(table, 0, sizeof(table));

    while (1) {
        vm_region_basic_info_data_64_t basic;
        vm_region_top_info_data_t top;
        mach_port_t object_name;
        vm_size_t size;

        count = VM_REGION_BASIC_INFO_COUNT_64;
        if (vm_region_64(task, &address, &size, VM_REGION_BASIC_INFO,
                         (vm_region_info_t)&basic,
                         &count, &object_name))
        {
            break;
        }

        count = VM_REGION_TOP_INFO_COUNT;
        if (vm_region_64(task, &address, &size, VM_REGION_TOP_INFO,
                         (vm_region_info_t)&top,
                         &count, &object_name))
        {
            break;
        }

        if ((address >= TEXT_SEGMENT_START) &&
            (address < DATA_SEGMENT_END))
        {
            if (!split && (top.share_mode == SM_EMPTY)) {
                if (basic.reserved) {
                    split = 1;
                }
            }
            if (top.share_mode != SM_PRIVATE) {
                address += size;
                continue;
            }
        }

        switch (top.share_mode) {
          case SM_COW:
            if (top.ref_count == 1) {
                private += top.private_pages_resident * vm_page_size;
                private += top.shared_pages_resident * vm_page_size;
                vprivate += size;
            }
            else {
                shared_table_register(table, &top, size);
                vprivate += top.private_pages_resident * vm_page_size;
            }
            break;
          case SM_PRIVATE:
            private += top.private_pages_resident * vm_page_size;
            vprivate += size;
            break;
          case SM_SHARED:
            shared_table_register(table, &top, size);
            break;
        }

        address += size;
    }

    for (i=0; i<SHARED_TABLE_SIZE; i++) {
        shared_info *sinfo = &table[i];

        while (sinfo) {
            if ((sinfo->share_mode == SM_SHARED) &&
                (sinfo->ref_count == sinfo->task_ref_count))
            {
                private += sinfo->page_count * vm_page_size;
                vprivate += sinfo->size;
            }
            else {
                shared += sinfo->page_count * vm_page_size;
            }
            sinfo = sinfo->next;
        }
    }
    shared_table_free(table);

    if (split) {
        vsize -= (DATA_SEGMENT_END - TEXT_SEGMENT_START);
    }

    if (task != self) {
        mach_port_deallocate(self, task);
    }

    procmem->size = vprivate;
    procmem->rss = private;
    procmem->share = shared;
    procmem->vsize = vsize;
    procmem->resident = resident;

    return SIGAR_OK;
#else
    int status = sigar_get_pinfo(sigar, pid);
    struct kinfo_proc *pinfo = sigar->pinfo;

    if (status != SIGAR_OK) {
        return status;
    }

    procmem->size = procmem->vsize = 
        (pinfo->KI_TSZ + pinfo->KI_DSZ + pinfo->KI_SSZ) * sigar->pagesize;

    procmem->resident = procmem->rss =
        pinfo->KI_RSS * sigar->pagesize;

    procmem->share = SIGAR_FIELD_NOTIMPL;

    procmem->page_faults  = SIGAR_FIELD_NOTIMPL;
    procmem->minor_faults = SIGAR_FIELD_NOTIMPL;
    procmem->major_faults = SIGAR_FIELD_NOTIMPL;

    return SIGAR_OK;
#endif
}

int sigar_proc_cred_get(sigar_t *sigar, sigar_pid_t pid,
                        sigar_proc_cred_t *proccred)
{
    int status = sigar_get_pinfo(sigar, pid);
    struct kinfo_proc *pinfo = sigar->pinfo;

    if (status != SIGAR_OK) {
        return status;
    }

    proccred->uid  = pinfo->KI_UID;
    proccred->gid  = pinfo->KI_GID;
    proccred->euid = pinfo->KI_EUID;
    proccred->egid = pinfo->KI_EGID;

    return SIGAR_OK;
}

#ifdef DARWIN
static int get_proc_times(sigar_pid_t pid, sigar_proc_time_t *time)
{
    unsigned int count;
    time_value_t utime = {0, 0}, stime = {0, 0};
    task_basic_info_data_t ti;
    task_thread_times_info_data_t tti;
    task_port_t task, self = mach_task_self();
    kern_return_t status;
    
    status = task_for_pid(self, pid, &task);
    if (status != KERN_SUCCESS) {
        return errno;
    }

    count = TASK_BASIC_INFO_COUNT;
    status = task_info(task, TASK_BASIC_INFO,
                       (task_info_t)&ti, &count);
    if (status != KERN_SUCCESS) {
        if (task != self) {
            mach_port_deallocate(self, task);
        }
        return errno;
    }

    count = TASK_THREAD_TIMES_INFO_COUNT;
    status = task_info(task, TASK_THREAD_TIMES_INFO,
                       (task_info_t)&tti, &count);
    if (status != KERN_SUCCESS) {
        if (task != self) {
            mach_port_deallocate(self, task);
        }
        return errno;
    }

    time_value_add(&utime, &ti.user_time);
    time_value_add(&stime, &ti.system_time);
    time_value_add(&utime, &tti.user_time);
    time_value_add(&stime, &tti.system_time);

    time->user = utime.seconds;
    time->sys  = stime.seconds;
    time->total = time->user + time->sys;

    return SIGAR_OK;
}
#endif

#define tv2sec(tv) \
   ((sigar_uint64_t)tv.tv_sec + (((sigar_uint64_t)tv.tv_usec) / 1000000))

int sigar_proc_time_get(sigar_t *sigar, sigar_pid_t pid,
                        sigar_proc_time_t *proctime)
{
    int status = sigar_get_pinfo(sigar, pid);
    struct kinfo_proc *pinfo = sigar->pinfo;

    if (status != SIGAR_OK) {
        return status;
    }

#if defined(DARWIN)
    if ((status = get_proc_times(pid, proctime)) != SIGAR_OK) {
        return status;
    }
    proctime->start_time = tv2sec(pinfo->KI_START) * 1000;
    return SIGAR_OK;
#elif defined(SIGAR_FREEBSD5)
    proctime->user  = tv2sec(pinfo->ki_rusage.ru_utime);
    proctime->sys   = tv2sec(pinfo->ki_rusage.ru_stime);
    proctime->total = proctime->user + proctime->sys;
    proctime->start_time = tv2sec(pinfo->KI_START) * 1000;
    return SIGAR_OK;
#else
    return SIGAR_ENOTIMPL;
#endif
}

int sigar_proc_state_get(sigar_t *sigar, sigar_pid_t pid,
                         sigar_proc_state_t *procstate)
{
    int status = sigar_get_pinfo(sigar, pid);
    struct kinfo_proc *pinfo = sigar->pinfo;
    
    if (status != SIGAR_OK) {
        return status;
    }

    SIGAR_SSTRCPY(procstate->name, pinfo->KI_COMM);
    procstate->ppid     = pinfo->KI_PPID;
    procstate->priority = pinfo->KI_PRI;
    procstate->nice     = pinfo->KI_NICE;
    procstate->tty      = SIGAR_FIELD_NOTIMPL; /*XXX*/
    procstate->threads  = SIGAR_FIELD_NOTIMPL;
    procstate->processor = SIGAR_FIELD_NOTIMPL;

    switch (pinfo->KI_STAT) {
      case SIDL:
        procstate->state = 'D';
        break;
      case SRUN:
        procstate->state = 'R';
        break;
      case SSLEEP:
        procstate->state = 'S';
        break;
      case SSTOP:
        procstate->state = 'T';
        break;
      case SZOMB:
        procstate->state = 'Z';
        break;
    }

    return SIGAR_OK;
}

int sigar_proc_args_get(sigar_t *sigar, sigar_pid_t pid,
                        sigar_proc_args_t *procargs)
{
#if defined(DARWIN)
    /*
     * derived from:
     * http://darwinsource.opendarwin.org/10.4.1/adv_cmds-79.1/ps.tproj/print.c
     */
    int mib[3], nargs;
    char buffer[8096], *args=buffer, *ptr, *end;
    size_t size = sizeof(buffer);

    mib[0] = CTL_KERN;
    mib[1] = KERN_PROCARGS2;
    mib[2] = pid;

    if (sysctl(mib, NMIB(mib), buffer, &size, NULL, 0) < 0) {
        return errno;
    }

    end = &args[size];

    memcpy(&nargs, buffer, sizeof(nargs));
    ptr = args + sizeof(nargs);

    /* full exec path */
    for (; ptr < end; ptr++) {
        if (*ptr == '\0') {
            break;
        }
    }

    if (ptr == end) {
        return ENOENT;
    }

    for (; ptr < end; ptr++) {
        if (*ptr != '\0') {
            break; /* start of argv[0] */
        }
    }

    if (ptr == end) {
        return ENOENT;
    }

    sigar_proc_args_create(procargs);

    while (*ptr && (nargs-- > 0)) {
        int alen = strlen(ptr)+1;
        char *arg = malloc(alen);

        SIGAR_PROC_ARGS_GROW(procargs);
        memcpy(arg, ptr, alen);

        procargs->data[procargs->number++] = arg;
            
        ptr += alen;
    }

    return SIGAR_OK;
#elif defined (__FreeBSD__) && (__FreeBSD_version >= 500013)
    char buffer[8096], *ptr=buffer;
    size_t len = sizeof(buffer);
    int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_ARGS, 0 };

    mib[3] = pid;

    if (sysctl(mib, NMIB(mib), buffer, &len, NULL, 0) < 0) {
        return errno;
    }

    sigar_proc_args_create(procargs);

    if (len == 0) {
        procargs->number = 0;
        return SIGAR_OK;
    }

    buffer[len] = '\0';

    while (*ptr) {
        int alen = strlen(ptr)+1;
        char *arg = malloc(alen);

        SIGAR_PROC_ARGS_GROW(procargs);
        memcpy(arg, ptr, alen);

        procargs->data[procargs->number++] = arg;

        ptr += alen;
    }

    return SIGAR_OK;
#else
    return PROCFS_STATUS(sigar_procfs_args_get(sigar, pid, procargs));
#endif
}

int sigar_proc_env_get(sigar_t *sigar, sigar_pid_t pid,
                       sigar_proc_env_t *procenv)
{
#ifdef DARWIN
    return SIGAR_ENOTIMPL;
#else
    char **env;
    struct kinfo_proc *pinfo;
    int num;

    if (!sigar->kmem) {
        return SIGAR_ENOTIMPL;
    }

    pinfo = kvm_getprocs(sigar->kmem, KERN_PROC_PID, pid, &num);
    if (!pinfo || (num < 1)) {
        return errno;
    }

    if (!(env = kvm_getenvv(sigar->kmem, pinfo, 9086))) {
        return errno;
    }

    while (*env) {
        char *ptr = *env++;
        char *val = strchr(ptr, '=');
        int klen, vlen, status;
        char key[128]; /* XXX is there a max key size? */

        if (val == NULL) {
            /* not key=val format */
            procenv->env_getter(procenv->data, ptr, strlen(ptr), NULL, 0);
            break;
        }

        klen = val - ptr;
        SIGAR_SSTRCPY(key, ptr);
        key[klen] = '\0';
        ++val;

        vlen = strlen(val);
        status = procenv->env_getter(procenv->data,
                                     key, klen, val, vlen);

        if (status != SIGAR_OK) {
            /* not an error; just stop iterating */
            break;
        }

        ptr += (klen + 1 + vlen + 1);
    }

    return SIGAR_OK;
#endif
}

int sigar_proc_fd_get(sigar_t *sigar, sigar_pid_t pid,
                      sigar_proc_fd_t *procfd)
{
#if defined(SIGAR_FREEBSD5)
    int status;
    struct kinfo_proc *pinfo;
    struct filedesc filed;
#if 0
    struct file **ofiles;
    int nfiles, i;
    size_t size;
#endif
    if (!sigar->kmem) {
        return SIGAR_ENOTIMPL;
    }

    if ((status = sigar_get_pinfo(sigar, pid)) != SIGAR_OK) {
        return status;
    }
    pinfo = sigar->pinfo;

    status = kread(sigar, &filed, sizeof(filed), (u_long)pinfo->ki_fd);
    if (status != SIGAR_OK) {
        return status;
    }
#if 0
    nfiles = filed.fd_lastfile+1;
    size = sizeof(*ofiles) * nfiles;
    ofiles = malloc(size);
    status = kread(sigar, ofiles, size, (u_long)filed.fd_ofiles);
    if (status != SIGAR_OK) {
        free(ofiles);
        return status;
    }

    procfd->total = 0;
    for (i=0; i<filed.fd_lastfile; i++) {
        if (!ofiles[i]) {
            continue;
        }
        procfd->total++;
    }

    free(ofiles);
#else
    /* seems the same as the above */
    procfd->total = filed.fd_lastfile;
#endif

    return SIGAR_OK;
#else
    return SIGAR_ENOTIMPL;
#endif
}

int sigar_proc_exe_get(sigar_t *sigar, sigar_pid_t pid,
                       sigar_proc_exe_t *procexe)
{
#ifdef DARWIN
    return SIGAR_ENOTIMPL;
#else
    int len;
    char name[1024];

    procexe->cwd[0] = '\0';
    procexe->root[0] = '\0';

    (void)SIGAR_PROC_FILENAME(name, pid, "/file");

    if ((len = readlink(name, procexe->name,
                        sizeof(procexe->name)-1)) < 0)
    {
        return PROCFS_STATUS(errno);
    }

    procexe->name[len] = '\0';

    return SIGAR_OK;
#endif
}

int sigar_proc_modules_get(sigar_t *sigar, sigar_pid_t pid,
                           sigar_proc_modules_t *procmods)
{
    return SIGAR_ENOTIMPL;
}

#define SIGAR_MICROSEC2NANO(s) \
    ((sigar_uint64_t)(s) * (sigar_uint64_t)1000)

#define TIME_NSEC(t) \
    (SIGAR_SEC2NANO((t).tv_sec) + SIGAR_MICROSEC2NANO((t).tv_usec))

int sigar_thread_cpu_get(sigar_t *sigar,
                         sigar_uint64_t id,
                         sigar_thread_cpu_t *cpu)
{
    /* XXX this is not per-thread, it is for the whole-process.
     * just want to use for the shell time command at the moment.
     */
    struct rusage usage;
    getrusage(RUSAGE_SELF, &usage);

    cpu->user  = TIME_NSEC(usage.ru_utime);
    cpu->sys   = TIME_NSEC(usage.ru_stime);
    cpu->total = TIME_NSEC(usage.ru_utime) + TIME_NSEC(usage.ru_stime);

    return SIGAR_OK;
}

int sigar_os_fs_type_get(sigar_file_system_t *fsp)
{
    char *type = fsp->sys_type_name;

    /* see sys/disklabel.h */
    switch (*type) {
      case 'h':
        if (strEQ(type, "hfs")) {
            fsp->type = SIGAR_FSTYPE_LOCAL_DISK;
        }
        break;
      case 'u':
        if (strEQ(type, "ufs")) {
            fsp->type = SIGAR_FSTYPE_LOCAL_DISK;
        }
        break;
    }

    return fsp->type;
}

int sigar_file_system_list_get(sigar_t *sigar,
                               sigar_file_system_list_t *fslist)
{
    struct statfs *fs;
    int num, i;
    long len;

    if ((num = getfsstat(NULL, 0, MNT_NOWAIT)) < 0) {
        return errno;
    }

    len = sizeof(*fs) * num;
    fs = malloc(len);

    if ((num = getfsstat(fs, len, MNT_NOWAIT)) < 0) {
        return errno;
    }

    sigar_file_system_list_create(fslist);

    for (i=0; i<num; i++) {
        sigar_file_system_t *fsp;

        SIGAR_FILE_SYSTEM_LIST_GROW(fslist);

        fsp = &fslist->data[fslist->number++];

        SIGAR_SSTRCPY(fsp->dir_name, fs[i].f_mntonname);
        SIGAR_SSTRCPY(fsp->dev_name, fs[i].f_mntfromname);
        SIGAR_SSTRCPY(fsp->sys_type_name, fs[i].f_fstypename);
        sigar_fs_type_init(fsp);
    }

    return SIGAR_OK;
}

int sigar_file_system_usage_get(sigar_t *sigar,
                                const char *dirname,
                                sigar_file_system_usage_t *fsusage)
{
    struct statfs buf;

    if (statfs(dirname, &buf) < 0) {
        return errno;
    }

    fsusage->total = SIGAR_FS_BLOCKS_TO_BYTES(buf, f_blocks);
    fsusage->free  = SIGAR_FS_BLOCKS_TO_BYTES(buf, f_bfree);
    fsusage->avail = SIGAR_FS_BLOCKS_TO_BYTES(buf, f_bavail);
    fsusage->used  = fsusage->total - fsusage->free;
    fsusage->files = buf.f_files;
    fsusage->free_files = buf.f_ffree;
    fsusage->use_percent = sigar_file_system_usage_calc_used(sigar, fsusage);

#ifdef DARWIN
    SIGAR_DISK_STATS_NOTIMPL(fsusage);
#else
    fsusage->disk_reads  = buf.f_syncreads + buf.f_asyncreads;
    fsusage->disk_writes = buf.f_syncwrites + buf.f_asyncwrites;
    fsusage->disk_read_bytes  = SIGAR_FIELD_NOTIMPL;
    fsusage->disk_write_bytes = SIGAR_FIELD_NOTIMPL;
    fsusage->disk_queue       = SIGAR_FIELD_NOTIMPL;
#endif

    return SIGAR_OK;
}

#ifdef DARWIN
#define CTL_HW_FREQ "hw.cpufrequency"
#else
/* XXX FreeBSD 5.x+ only? */ 
#define CTL_HW_FREQ "machdep.tsc_freq"
#endif

int sigar_cpu_info_list_get(sigar_t *sigar,
                            sigar_cpu_info_list_t *cpu_infos)
{
    int i;
    unsigned int mhz;
    size_t size;
    char model[128], vendor[128], *ptr;

    size = sizeof(mhz);
    if (sysctlbyname(CTL_HW_FREQ, &mhz, &size, NULL, 0) < 0) {
        int mib[] = { CTL_HW, HW_CPU_FREQ };
        size = sizeof(mhz);
        if (sysctl(mib, NMIB(mib), &mhz, &size, NULL, 0) < 0) {
            mhz = SIGAR_FIELD_NOTIMPL;
        }
    }
    if (mhz != SIGAR_FIELD_NOTIMPL) {
        mhz /= 1000000;
    }

    size = sizeof(model);
    if (sysctlbyname("hw.model", &model, &size, NULL, 0) == -1) {
        strcpy(model, "Unknown");
    }
    else if ((ptr = strchr(model, ' '))) {
        *ptr = '\0';
        if (strstr(model, "Intel")) {
            SIGAR_SSTRCPY(vendor, "Intel");
        }
        else if (strstr(model, "AMD")) {
            SIGAR_SSTRCPY(vendor, "AMD");
        }
        else {
            SIGAR_SSTRCPY(vendor, "Unknown");
        }
        SIGAR_SSTRCPY(model, ptr+1);
    }

    sigar_cpu_info_list_create(cpu_infos);

    for (i=0; i<sigar->ncpu; i++) {
        sigar_cpu_info_t *info;

        SIGAR_CPU_INFO_LIST_GROW(cpu_infos);

        info = &cpu_infos->data[cpu_infos->number++];
#ifdef DARWIN
        SIGAR_SSTRCPY(info->vendor, "Apple");
        SIGAR_SSTRCPY(info->model, "powerpc");
#else
        SIGAR_SSTRCPY(info->vendor, vendor);
        SIGAR_SSTRCPY(info->model, model);
        sigar_cpu_model_adjust(sigar, info);
#endif
        info->mhz = mhz;
        info->cache_size = SIGAR_FIELD_NOTIMPL;
    }

    return SIGAR_OK;
}

#define rt_s_addr(sa) ((struct sockaddr_in *)(sa))->sin_addr.s_addr

#ifndef SA_SIZE
#define SA_SIZE(sa)                                             \
    (  (!(sa) || ((struct sockaddr *)(sa))->sa_len == 0) ?      \
        sizeof(long)            :                               \
        1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(long) - 1) ) )
#endif

int sigar_net_route_list_get(sigar_t *sigar,
                             sigar_net_route_list_t *routelist)
{
#if defined(SIGAR_FREEBSD5) || defined(DARWIN)
    size_t needed;
    int bit;
    char *buf, *next, *lim;
    struct rt_msghdr *rtm;
    int mib[6] = { CTL_NET, PF_ROUTE, 0, 0, NET_RT_DUMP, 0 };

    if (sysctl(mib, NMIB(mib), NULL, &needed, NULL, 0) < 0) {
        return errno;
    }

    buf = malloc(needed);

    if (sysctl(mib, NMIB(mib), buf, &needed, NULL, 0) < 0) {
        free(buf);
        return errno;
    }

    sigar_net_route_list_create(routelist);

    lim = buf + needed;
    for (next = buf; next < lim; next += rtm->rtm_msglen) {
        struct sockaddr *sa;
        sigar_net_route_t *route;
        rtm = (struct rt_msghdr *)next;

        if (rtm->rtm_type != RTM_GET) {
            continue;
        }

        sa = (struct sockaddr *)(rtm + 1);

        if (sa->sa_family != AF_INET) {
            continue;
        }

        SIGAR_NET_ROUTE_LIST_GROW(routelist);
        route = &routelist->data[routelist->number++];
        SIGAR_ZERO(route);

        route->flags = rtm->rtm_flags;

        for (bit=RTA_DST;
             bit && ((char *)sa < lim);
             bit <<= 1)
        {
            if ((rtm->rtm_addrs & bit) == 0) {
                continue;
            }
            switch (bit) {
              case RTA_DST:
                route->destination = rt_s_addr(sa);
                break;
              case RTA_GATEWAY:
                if (sa->sa_family == AF_INET) {
                    route->gateway = rt_s_addr(sa);
                }
                break;
              case RTA_NETMASK:
                route->mask = rt_s_addr(sa);
                break;
              case RTA_IFA:
                break;
            }

            sa = (struct sockaddr *)((char *)sa + SA_SIZE(sa));
        }
    }

    free(buf);

    return SIGAR_OK;
#else
    return SIGAR_ENOTIMPL;
#endif
}

typedef enum {
    IFMSG_ITER_LIST,
    IFMSG_ITER_GET
} ifmsg_iter_e;

typedef struct {
    const char *name;
    ifmsg_iter_e type;
    union {
        sigar_net_interface_list_t *iflist;
        struct if_msghdr *ifm;
    } data;
} ifmsg_iter_t;

static int sigar_ifmsg_init(sigar_t *sigar)
{
    int mib[] = { CTL_NET, PF_ROUTE, 0, AF_INET, NET_RT_IFLIST, 0 };
    size_t len;

    if (sysctl(mib, NMIB(mib), NULL, &len, NULL, 0) < 0) {
        return errno;
    }

    if (sigar->ifconf_len < len) {
        sigar->ifconf_buf = realloc(sigar->ifconf_buf, len);
        sigar->ifconf_len = len;
    }

    if (sysctl(mib, NMIB(mib), sigar->ifconf_buf, &len, NULL, 0) < 0) {
        return errno;
    }

    return SIGAR_OK;
}

static int sigar_ifmsg_iter(sigar_t *sigar, ifmsg_iter_t *iter)
{
    char *end = sigar->ifconf_buf + sigar->ifconf_len;
    char *ptr = sigar->ifconf_buf;

    if (iter->type == IFMSG_ITER_LIST) {
        sigar_net_interface_list_create(iter->data.iflist);
    }

    while (ptr < end) {
        char *name;
        struct sockaddr_dl *sdl;
        struct if_msghdr *ifm = (struct if_msghdr *)ptr;
        
        if (ifm->ifm_type != RTM_IFINFO) {
            break;
        }

        ptr += ifm->ifm_msglen;
        
        while (ptr < end) {
            struct if_msghdr *next = (struct if_msghdr *)ptr;

            if (next->ifm_type != RTM_NEWADDR) {
                break;
            }

            ptr += next->ifm_msglen;
        }

        sdl = (struct sockaddr_dl *)(ifm + 1);
        if (sdl->sdl_family != AF_LINK) {
            continue;
        }

        switch (iter->type) {
          case IFMSG_ITER_LIST:
            SIGAR_NET_IFLIST_GROW(iter->data.iflist);

            name = malloc(sdl->sdl_nlen+1);
            memcpy(name, sdl->sdl_data, sdl->sdl_nlen+1);

            iter->data.iflist->data[iter->data.iflist->number++] = name;
            break;

          case IFMSG_ITER_GET:
            if (strEQ(iter->name, sdl->sdl_data)) {
                iter->data.ifm = ifm;
                return SIGAR_OK;
            }
        }
    }

    switch (iter->type) {
      case IFMSG_ITER_LIST:
        return SIGAR_OK;

      case IFMSG_ITER_GET:
      default:
        return ENXIO;
    }
}

int sigar_net_interface_list_get(sigar_t *sigar,
                                 sigar_net_interface_list_t *iflist)
{
    int status;
    ifmsg_iter_t iter;

    if ((status = sigar_ifmsg_init(sigar)) != SIGAR_OK) {
        return status;
    }

    iter.type = IFMSG_ITER_LIST;
    iter.data.iflist = iflist;

    return sigar_ifmsg_iter(sigar, &iter);
}

int sigar_net_interface_config_get(sigar_t *sigar, const char *name,
                                   sigar_net_interface_config_t *ifconfig)
{
    int sock;
    int status;
    ifmsg_iter_t iter;
    struct if_msghdr *ifm;
    struct sockaddr_dl *sdl;
    struct ifreq ifr;

    if (sigar->ifconf_len == 0) {
        if ((status = sigar_ifmsg_init(sigar)) != SIGAR_OK) {
            return status;
        }
    }

    iter.type = IFMSG_ITER_GET;
    iter.name = name;

    if ((status = sigar_ifmsg_iter(sigar, &iter)) != SIGAR_OK) {
        return status;
    }

    if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        return errno;
    }

    ifm = iter.data.ifm;

    SIGAR_SSTRCPY(ifconfig->name, name);

    sdl = (struct sockaddr_dl *)(ifm + 1);
    sigar_hwaddr_format(ifconfig->hwaddr,
                        (unsigned char *)LLADDR(sdl));

    ifconfig->flags = ifm->ifm_flags;
    ifconfig->mtu = ifm->ifm_data.ifi_mtu;
    ifconfig->metric = ifm->ifm_data.ifi_metric;

    SIGAR_SSTRCPY(ifr.ifr_name, name);

#define ifr_s_addr(ifr) \
    ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr

    if (!ioctl(sock, SIOCGIFADDR, &ifr)) {
        ifconfig->address = ifr_s_addr(ifr);
    }

    if (!ioctl(sock, SIOCGIFNETMASK, &ifr)) {
        ifconfig->netmask = ifr_s_addr(ifr);
    }

    if (ifconfig->flags & IFF_LOOPBACK) {
        ifconfig->destination = ifconfig->address;
        ifconfig->broadcast = 0;
        SIGAR_SSTRCPY(ifconfig->type,
                      SIGAR_NIC_LOOPBACK);
    }
    else {
        if (!ioctl(sock, SIOCGIFDSTADDR, &ifr)) {
            ifconfig->destination = ifr_s_addr(ifr);
        }

        if (!ioctl(sock, SIOCGIFBRDADDR, &ifr)) {
            ifconfig->broadcast = ifr_s_addr(ifr);
        }
        SIGAR_SSTRCPY(ifconfig->type,
                      SIGAR_NIC_ETHERNET);
    }

    close(sock);

    return SIGAR_OK;
}

int sigar_net_interface_stat_get(sigar_t *sigar, const char *name,
                                 sigar_net_interface_stat_t *ifstat)
{
    int status;
    ifmsg_iter_t iter;
    struct if_msghdr *ifm;

    if (sigar->ifconf_len == 0) {
        if ((status = sigar_ifmsg_init(sigar)) != SIGAR_OK) {
            return status;
        }
    }

    iter.type = IFMSG_ITER_GET;
    iter.name = name;

    if ((status = sigar_ifmsg_iter(sigar, &iter)) != SIGAR_OK) {
        return status;
    }

    ifm = iter.data.ifm;

    ifstat->rx_bytes      = ifm->ifm_data.ifi_ibytes;
    ifstat->rx_packets    = ifm->ifm_data.ifi_ipackets;
    ifstat->rx_errors     = ifm->ifm_data.ifi_ierrors;
    ifstat->rx_dropped    = ifm->ifm_data.ifi_iqdrops;
    ifstat->rx_overruns   = SIGAR_FIELD_NOTIMPL;
    ifstat->rx_frame      = SIGAR_FIELD_NOTIMPL;

    ifstat->tx_bytes      = ifm->ifm_data.ifi_obytes;
    ifstat->tx_packets    = ifm->ifm_data.ifi_opackets;
    ifstat->tx_errors     = ifm->ifm_data.ifi_oerrors;
    ifstat->tx_collisions = ifm->ifm_data.ifi_collisions;
    ifstat->tx_dropped    = SIGAR_FIELD_NOTIMPL;
    ifstat->tx_overruns   = SIGAR_FIELD_NOTIMPL;
    ifstat->tx_carrier    = SIGAR_FIELD_NOTIMPL;

    return SIGAR_OK;
}

#if defined(SIGAR_FREEBSD5) || defined(DARWIN)

#include <sys/socketvar.h>
#include <netinet/tcp.h>
#include <netinet/in_pcb.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_fsm.h>

static int net_connection_list_get(sigar_t *sigar,
                                   sigar_net_connection_list_t *connlist,
                                   int flags, int proto)
{
    int type, istcp = 0;
    char *buf;
    const char *mibvar;
    struct tcpcb *tp = NULL;
    struct inpcb *inp;
    struct xinpgen *xig, *oxig;
    struct xsocket *so;
    size_t len;

    switch (proto) {
      case IPPROTO_TCP:
        mibvar = "net.inet.tcp.pcblist";
        istcp = 1;
        type = SIGAR_NETCONN_TCP;
        break;
      case IPPROTO_UDP:
        mibvar = "net.inet.udp.pcblist";
        type = SIGAR_NETCONN_UDP;
        break;
      default:
        mibvar = "net.inet.raw.pcblist";
        type = SIGAR_NETCONN_RAW;
        break;
    }

    len = 0;
    if (sysctlbyname(mibvar, 0, &len, 0, 0) < 0) {
        return errno;
    }
    if ((buf = malloc(len)) == 0) {
        return errno;
    }
    if (sysctlbyname(mibvar, buf, &len, 0, 0) < 0) {
        free(buf);
        return errno;
    }

    oxig = xig = (struct xinpgen *)buf;
    for (xig = (struct xinpgen *)((char *)xig + xig->xig_len);
         xig->xig_len > sizeof(struct xinpgen);
         xig = (struct xinpgen *)((char *)xig + xig->xig_len))
    {
        if (istcp) {
            struct xtcpcb *cb = (struct xtcpcb *)xig;
            tp = &cb->xt_tp;
            inp = &cb->xt_inp;
            so = &cb->xt_socket;
        }
        else {
            struct xinpcb *cb = (struct xincb *)xig;
            inp = &cb->xi_inp;
            so = &cb->xi_socket;
        }

        if (so->xso_protocol != proto) {
            continue;
        }

        if (inp->inp_gencnt > oxig->xig_gen) {
            continue;
        }

        if ((((flags & SIGAR_NETCONN_SERVER) && so->so_qlimit) ||
            ((flags & SIGAR_NETCONN_CLIENT) && !so->so_qlimit)))
        {
            sigar_net_connection_t *conn;

            SIGAR_NET_CONNLIST_GROW(connlist);
            conn = &connlist->data[connlist->number++];

            sigar_inet_ntoa(sigar, inp->inp_laddr.s_addr,
                            conn->local_address);
            sigar_inet_ntoa(sigar, inp->inp_faddr.s_addr,
                            conn->remote_address);
            conn->local_port  = ntohs(inp->inp_lport);
            conn->remote_port = ntohs(inp->inp_fport);
            conn->receive_queue = so->so_rcv.sb_cc;
            conn->send_queue    = so->so_snd.sb_cc;
            conn->type = type;

            if (!istcp) {
                conn->state = SIGAR_TCP_UNKNOWN;
                continue;
            }

            switch (tp->t_state) {
              case TCPS_CLOSED:
                conn->state = SIGAR_TCP_CLOSE;
                break;
              case TCPS_LISTEN:
                conn->state = SIGAR_TCP_LISTEN;
                break;
              case TCPS_SYN_SENT:
                conn->state = SIGAR_TCP_SYN_SENT;
                break;
              case TCPS_SYN_RECEIVED:
                conn->state = SIGAR_TCP_SYN_RECV;
                break;
              case TCPS_ESTABLISHED:
                conn->state = SIGAR_TCP_ESTABLISHED;
                break;
              case TCPS_CLOSE_WAIT:
                conn->state = SIGAR_TCP_CLOSE_WAIT;
                break;
              case TCPS_FIN_WAIT_1:
                conn->state = SIGAR_TCP_FIN_WAIT1;
                break;
              case TCPS_CLOSING:
                conn->state = SIGAR_TCP_CLOSING;
                break;
              case TCPS_LAST_ACK:
                conn->state = SIGAR_TCP_LAST_ACK;
                break;
              case TCPS_FIN_WAIT_2:
                conn->state = SIGAR_TCP_FIN_WAIT2;
                break;
              case TCPS_TIME_WAIT:
                conn->state = SIGAR_TCP_TIME_WAIT;
                break;
              default:
                conn->state = SIGAR_TCP_UNKNOWN;
                break;
            }
        }
    }

    free(buf);

    return SIGAR_OK;
}

int sigar_net_connection_list_get(sigar_t *sigar,
                                  sigar_net_connection_list_t *connlist,
                                  int flags)
{
    int status;

    sigar_net_connection_list_create(connlist);

    if (flags & SIGAR_NETCONN_TCP) {
        status = net_connection_list_get(sigar, connlist,
                                         flags, IPPROTO_TCP);
        if (status != SIGAR_OK) {
            return status;
        }
    }
    if (flags & SIGAR_NETCONN_UDP) {
        status = net_connection_list_get(sigar, connlist,
                                         flags, IPPROTO_UDP);
        if (status != SIGAR_OK) {
            return status;
        }
    }

    return SIGAR_OK;
}
#else
int sigar_net_connection_list_get(sigar_t *sigar,
                                  sigar_net_connection_list_t *connlist,
                                  int flags)
{
    return SIGAR_ENOTIMPL;
}
#endif

#if defined(SIGAR_FREEBSD5)

#define _KERNEL
#include <sys/file.h>
#undef _KERNEL

/* derived from
 * /usr/ports/security/pidentd/work/pidentd-3.0.16/src/k_freebsd2.c
 */
int sigar_proc_port_get(sigar_t *sigar, int protocol,
                        unsigned long port, sigar_pid_t *pid)
{
    struct nlist nl[2];
    struct inpcbhead tcb;
    struct socket *sockp = NULL;
    struct kinfo_proc *pinfo;
    struct inpcb *head, pcbp;
    int i, nentries, status;

    if (protocol != SIGAR_NETCONN_TCP) {
        return SIGAR_ENOTIMPL;
    }

    if (!sigar->kmem) {
        return EPERM;
    }

    nl[0].n_name = "_tcb"; /* XXX cache */
    nl[1].n_name = "";
    if (kvm_nlist(sigar->kmem, nl) < 0) {
        return errno;
    }

    status = kread(sigar, &tcb, sizeof(tcb), nl[0].n_value);
    if (status != SIGAR_OK) {
        return status;
    }

    for (head = tcb.lh_first; head != NULL;
         head = pcbp.inp_list.le_next)
    {
        status = kread(sigar, &pcbp, sizeof(pcbp), (long)head);
        if (status != SIGAR_OK) {
            return status;
        }
        if (!(pcbp.inp_vflag & INP_IPV4)) {
            continue;
        }
        if (pcbp.inp_fport != 0) {
            continue;
        }
        if (ntohs(pcbp.inp_lport) == port) {
            sockp = pcbp.inp_socket;
            break;
        }
    }

    if (!sockp) {
        return ENOENT;
    }

    pinfo = kvm_getprocs(sigar->kmem, KERN_PROC_PROC, 0, &nentries);
    if (!pinfo) {
        return errno;
    }

    for (i=0; i<nentries; i++) {
        if (pinfo[i].KI_FLAG & P_SYSTEM) {
            continue;
        }
        if (pinfo[i].ki_fd) {
            struct filedesc pfd;
            struct file **ofiles, ofile;
            int j, osize;

            status = kread(sigar, &pfd, sizeof(pfd), (long)pinfo[i].ki_fd);
            if (status != SIGAR_OK) {
                return status;
            }

            osize = pfd.fd_nfiles * sizeof(struct file *);
            ofiles = malloc(osize); /* XXX reuse */
            if (!ofiles) {
                return errno;
            }

            status = kread(sigar, ofiles, osize, (long)pfd.fd_ofiles);
            if (status != SIGAR_OK) {
                free(ofiles);
                return status;
            }

            for (j=0; j<pfd.fd_nfiles; j++) {
                if (!ofiles[j]) {
                    continue;
                }

                status = kread(sigar, &ofile, sizeof(ofile), (long)ofiles[j]);
                if (status != SIGAR_OK) {
                    free(ofiles);
                    return status;
                }

                if (ofile.f_count == 0) {
                    continue;
                }

                if (ofile.f_type == DTYPE_SOCKET &&
                    (struct socket *)ofile.f_data == sockp)
                {
                    *pid = pinfo[i].ki_pid;
                    free(ofiles);
                    return SIGAR_OK;
                }
            }

            free(ofiles);
        }
    }

    return ENOENT;
}

#else

int sigar_proc_port_get(sigar_t *sigar, int protocol,
                        unsigned long port, sigar_pid_t *pid)
{
    return SIGAR_ENOTIMPL;
}

#endif