#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/param.h>
#include <sys/stat.h>

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

#include <asm/page.h> /* for PAGE_SHIFT */

#define pageshift(x) ((x) << PAGE_SHIFT)

#define PROC_MEMINFO PROC_FS_ROOT "meminfo"
#define PROC_STAT    PROC_FS_ROOT "stat"
#define PROC_UPTIME  PROC_FS_ROOT "uptime"
#define PROC_LOADAVG PROC_FS_ROOT "loadavg"

#define PROC_PSTAT   "/stat"
#define PROC_PSTATUS "/status"

/*
 * /proc/self/stat fields:
 * 1 - pid
 * 2 - comm
 * 3 - state
 * 4 - ppid
 * 5 - pgrp
 * 6 - session
 * 7 - tty_nr
 * 8 - tpgid
 * 9 - flags
 * 10 - minflt
 * 11 - cminflt
 * 12 - majflt
 * 13 - cmajflt
 * 14 - utime
 * 14 - stime
 * 15 - cutime
 * 16 - cstime
 * 17 - priority
 * 18 - nice
 * 19 - 0 (removed field)
 * 20 - itrealvalue
 * 21 - starttime
 * 22 - vsize
 * 23 - rss
 * 24 - rlim
 * 25 - startcode
 * 26 - endcode
 * 27 - startstack
 * 28 - kstkesp
 * 29 - kstkeip
 * 30 - signal
 * 31 - blocked
 * 32 - sigignore
 * 33 - sigcache
 * 34 - wchan
 * 35 - nswap
 * 36 - cnswap
 * 37 - exit_signal <-- looking for this.
 * 38 - processor
 * ... more for newer RH
 */

#define PROC_SIGNAL_IX 38

static int get_proc_signal_offset(void)
{
    char buffer[BUFSIZ], *ptr=buffer;
    int fields = 0;
    int status = sigar_file2str("/proc/self/stat",
                                buffer, sizeof(buffer));

    if (status != SIGAR_OK) {
        return 1;
    }

    while (*ptr) {
        if (*ptr++ == ' ') {
            fields++;
        }
    }

    return (fields - PROC_SIGNAL_IX) + 1;
}

sigar_pid_t sigar_pid_get(sigar_t *sigar)
{
    /* XXX cannot safely cache getpid unless using nptl */
    /* we can however, cache it for optimizations in the
     * case of proc_env_get for example.
     */
    sigar->pid = getpid();
    return sigar->pid;
}

int sigar_os_open(sigar_t **sigar)
{
    char buffer[BUFSIZ], *ptr;
    int status = sigar_file2str(PROC_STAT, buffer, sizeof(buffer));

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

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

    ptr = strstr(buffer, "\nbtime");
    ptr = sigar_skip_token(ptr);
    (*sigar)->boot_time = sigar_strtoul(ptr);

    (*sigar)->ticks = 100; /* HZ */

    (*sigar)->ram = -1;

    (*sigar)->proc_signal_offset = -1;

    (*sigar)->last_proc_stat.pid = -1;

    (*sigar)->ht_enabled = -1;

    return SIGAR_OK;
}

int sigar_os_close(sigar_t *sigar)
{
    free(sigar);
    return SIGAR_OK;
}

char *sigar_os_error_string(int err)
{
    return NULL;
}

static int is_ht_enabled(sigar_t *sigar)
{
    if (sigar->ht_enabled == -1) {
        /* only check once */
        sigar_cpu_info_list_t cpuinfos;

        if (sigar_cpu_info_list_get(sigar, &cpuinfos) != SIGAR_OK) {
            sigar->ht_enabled = 0; /* chances we reach here: slim..none */
        }

        sigar_cpu_info_list_destroy(sigar, &cpuinfos);
    }

    return sigar->ht_enabled;
}

static int get_ram(sigar_t *sigar, sigar_mem_t *mem)
{
    char buffer[BUFSIZ], *ptr;
    FILE *fp;
    int total = 0;

    if (sigar->ram > 0) {
        /* return cached value */
        mem->ram = sigar->ram;
        return SIGAR_OK;
    }

    if (sigar->ram == 0) {
        return ENOENT;
    }

    /*
     * Memory Type Range Registers
     * write-back registers add up to the total.
     */
    if (!(fp = fopen("/proc/mtrr", "r"))) {
        return errno;
    }

    while ((ptr = fgets(buffer, sizeof(buffer), fp))) {
        if (!(ptr = strstr(ptr, "size="))) {
            continue;
        }

        if (!strstr(ptr, "write-back")) {
            continue;
        }

        ptr += 5;
        while (sigar_isspace(*ptr)) {
            ++ptr;
        }

        total += atoi(ptr);
    }

    fclose(fp);

    if (total == 0) {
        return ENOENT;
    }

    mem->ram = sigar->ram = total;

    return SIGAR_OK;
}

int sigar_mem_get(sigar_t *sigar, sigar_mem_t *mem)
{
    char buffer[BUFSIZ];
    char *ptr;

    int status = sigar_file2str(PROC_MEMINFO,
                                buffer, sizeof(buffer));

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

    ptr = sigar_skip_line(buffer, sizeof(buffer));
    ptr = sigar_skip_token(ptr); /* "Mem:" */

    mem->total  = sigar_strtoul(ptr);
    mem->used   = sigar_strtoul(ptr);
    mem->free   = sigar_strtoul(ptr);
    mem->shared = sigar_strtoul(ptr);
    mem->buffer = sigar_strtoul(ptr);
    mem->cached = sigar_strtoul(ptr);

    if (get_ram(sigar, mem) != SIGAR_OK) {
        /* XXX other options on failure? */
        sigar_mem_calc_ram(sigar, mem);
    }

    return SIGAR_OK;
}

int sigar_swap_get(sigar_t *sigar, sigar_swap_t *swap)
{
    char buffer[BUFSIZ];
    char *ptr;

    /* XXX: we open/parse the same file here as sigar_mem_get */
    int status = sigar_file2str(PROC_MEMINFO,
                                buffer, sizeof(buffer));

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

    ptr = sigar_skip_line(buffer, sizeof(buffer));
    ptr = sigar_skip_line(ptr, 0);
    ptr = sigar_skip_token(ptr); /* "Swap:" */

    swap->total  = sigar_strtoul(ptr);
    swap->used   = sigar_strtoul(ptr);
    swap->free   = sigar_strtoul(ptr);

    return SIGAR_OK;
}

static void get_cpu_metrics(sigar_cpu_t *cpu, char *line)
{
    char *ptr = sigar_skip_token(line); /* "cpu%d" */

    cpu->user += sigar_strtoul(ptr);
    cpu->nice += sigar_strtoul(ptr);
    cpu->sys  += sigar_strtoul(ptr);
    cpu->idle += sigar_strtoul(ptr);

    cpu->total += cpu->user + cpu->nice + cpu->sys + cpu->idle;
}

int sigar_cpu_get(sigar_t *sigar, sigar_cpu_t *cpu)
{
    char buffer[BUFSIZ];
    int status = sigar_file2str(PROC_STAT, buffer, sizeof(buffer));

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

    SIGAR_ZERO(cpu);
    get_cpu_metrics(cpu, buffer);

    return SIGAR_OK;
}

int sigar_cpu_list_get(sigar_t *sigar, sigar_cpu_list_t *cpulist)
{
    FILE *fp;
    char buffer[BUFSIZ], cpu_total[BUFSIZ], *ptr;
    int hthread = is_ht_enabled(sigar), i=0;
    sigar_cpu_t *cpu;

    if (!(fp = fopen(PROC_STAT, "r"))) {
        return errno;
    }

    /* skip first line */
    (void)fgets(cpu_total, sizeof(cpu_total), fp);

    sigar_cpu_list_create(cpulist);

    /* XXX: merge times of logical processors if hyperthreading */
    while ((ptr = fgets(buffer, sizeof(buffer), fp))) {
        if (!strnEQ(ptr, "cpu", 3)) {
            break;
        }

        if (hthread && (i % sigar->lcpu)) {
            /* merge times of logical processors */
            cpu = &cpulist->data[cpulist->number-1];
        }
        else {
            SIGAR_CPU_LIST_GROW(cpulist);
            cpu = &cpulist->data[cpulist->number++];
            SIGAR_ZERO(cpu);
        }

        get_cpu_metrics(cpu, ptr);

        i++;
    }

    fclose(fp);

    if (cpulist->number == 0) {
        /* likely older kernel where cpu\d is not present */
        cpu = &cpulist->data[cpulist->number++];
        SIGAR_ZERO(cpu);
        get_cpu_metrics(cpu, cpu_total);
    }

    return SIGAR_OK;
}

int sigar_uptime_get(sigar_t *sigar,
                     sigar_uptime_t *uptime)
{
    char buffer[BUFSIZ], *ptr = buffer;
    int status = sigar_file2str(PROC_UPTIME, buffer, sizeof(buffer));

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

    uptime->uptime   = strtod(buffer, &ptr);

    return SIGAR_OK;
}

int sigar_loadavg_get(sigar_t *sigar,
                      sigar_loadavg_t *loadavg)
{
    char buffer[BUFSIZ], *ptr = buffer;
    int status = sigar_file2str(PROC_LOADAVG, buffer, sizeof(buffer));

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

    loadavg->loadavg[0] = strtod(buffer, &ptr);
    loadavg->loadavg[1] = strtod(ptr, &ptr);
    loadavg->loadavg[2] = strtod(ptr, &ptr);

    return SIGAR_OK;
}

/*
 * seems the easiest/fastest way to tell if a process listed in /proc
 * is a thread is to check the "exit signal" flag in /proc/num/stat.
 * any value other than SIGCHLD seems to be a thread.  this make hulk mad.
 * redhat's procps patch (named "threadbadhack.pat") does not use
 * this flag to filter out threads.  instead does much more expensive
 * comparisions.  their patch also bubbles up thread cpu times to the main
 * process.  functionality we currently lack.
 * when nptl is in use, this is not the case and all threads spawned from
 * a process have the same pid.  however, it seems both old-style linux
 * threads and nptl threads can be run on the same machine.
 * there is also the "Tgid" field in /proc/self/status which could be used
 * to detect threads, but this is not available in older kernels.
 */
static SIGAR_INLINE int proc_isthread(sigar_t *sigar, char *pidstr, int len)
{
    char buffer[BUFSIZ], *ptr=buffer;
    int fd, n, offset=sigar->proc_signal_offset;

    /* sprintf(buffer, "/proc/%s/stat", pidstr) */
    memcpy(ptr, PROC_FS_ROOT, SSTRLEN(PROC_FS_ROOT));
    ptr += SSTRLEN(PROC_FS_ROOT);

    memcpy(ptr, pidstr, len);
    ptr += len;

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

    *ptr = '\0';

    if ((fd = open(buffer, O_RDONLY)) < 0) {
        /* unlikely if pid was from readdir proc */
        return 0;
    }

    n = read(fd, buffer, sizeof(buffer));
    close(fd);

    if (n < 0) {
        return 0; /* chances: slim..none */
    }

    buffer[n--] = '\0';

    /* exit_signal is the second to last field so we look backwards.
     * XXX if newer kernels drop more turds in this file we'll need
     * to go the other way.  luckily linux has no real api for this shit.
     */

    /* skip trailing crap */
    while ((n > 0) && !isdigit(buffer[n--])) ;

    while (offset-- > 0) {
        /* skip last field */
        while ((n > 0) && isdigit(buffer[n--])) ;

        /* skip whitespace */
        while ((n > 0) && !isdigit(buffer[n--])) ;
    }

    if (n < 3) {
        return 0; /* hulk smashed /proc? */
    }

    ptr = &buffer[n];
    /*
     * '17' == SIGCHLD == real process.
     * '33' and '0' are threads
     */
    if ((*ptr++ == '1') &&
        (*ptr++ == '7') &&
        (*ptr++ == ' '))
    {
        return 0;
    }

    return 1;
}

int sigar_proc_list_get(sigar_t *sigar,
                        sigar_proc_list_t *proclist)
{
    DIR *dirp = opendir("/proc");
    struct dirent *ent, dbuf;

    if (!dirp) {
        return errno;
    }

    if (sigar->proc_signal_offset == -1) {
        sigar->proc_signal_offset = get_proc_signal_offset();
    }

    sigar_proc_list_create(proclist);

    while (readdir_r(dirp, &dbuf, &ent) == 0) {
        if (!ent) {
            break;
        }

        if (!sigar_isdigit(*ent->d_name)) {
            continue;
        }

        if (proc_isthread(sigar, ent->d_name, strlen(ent->d_name)))
        {
            continue;
        }

        /* XXX: more sanity checking */

        SIGAR_PROC_LIST_GROW(proclist);

        proclist->data[proclist->number++] =
            strtoul(ent->d_name, NULL, 10);
    }

    closedir(dirp);

    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 proc_stat_read(sigar_t *sigar, sigar_pid_t pid)
{
    char buffer[BUFSIZ], *ptr=buffer, *tmp;
    unsigned int len;
    linux_proc_stat_t *pstat = &sigar->last_proc_stat;
    int status;

    time_t timenow = time(NULL);

    /* 
     * short-lived cache read/parse of last /proc/pid/stat
     * as this info is spread out across a few functions.
     */
    if (pstat->pid == pid) {
        if ((timenow - pstat->mtime) < SIGAR_LAST_PROC_EXPIRE) {
            return SIGAR_OK;
        }
    }

    pstat->pid = pid;
    pstat->mtime = timenow;

    status = SIGAR_PROC_FILE2STR(buffer, pid, PROC_PSTAT);

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

    ptr = strchr(ptr, '(')+1;

    tmp = strrchr(ptr, ')');
    len = tmp-ptr;

    if (len >= sizeof(pstat->name)) {
        len = sizeof(pstat->name)-1;
    }

    memcpy(pstat->name, ptr, len);
    pstat->name[len] = '\0';
    ptr = tmp+1;

    SIGAR_SKIP_SPACE(ptr);
    pstat->state = *ptr++;
    SIGAR_SKIP_SPACE(ptr);

    pstat->ppid = sigar_strtoul(ptr);
    ptr = sigar_skip_token(ptr); /* pgrp */
    ptr = sigar_skip_token(ptr); /* session */
    pstat->tty = sigar_strtoul(ptr);
    ptr = sigar_skip_token(ptr); /* tty pgrp */

    ptr = sigar_skip_token(ptr); /* flags */
    ptr = sigar_skip_token(ptr); /* min flt */
    ptr = sigar_skip_token(ptr); /* cmin flt */
    ptr = sigar_skip_token(ptr); /* maj flt */
    ptr = sigar_skip_token(ptr); /* cmaj flt */

    pstat->utime = sigar_strtoul(ptr) / sigar->ticks;
    pstat->stime = sigar_strtoul(ptr) / sigar->ticks;

    ptr = sigar_skip_token(ptr); /* cutime */
    ptr = sigar_skip_token(ptr); /* cstime */

    pstat->priority = sigar_strtoul(ptr);
    pstat->nice     = sigar_strtoul(ptr);

    ptr = sigar_skip_token(ptr); /* timeout */
    ptr = sigar_skip_token(ptr); /* it_real_value */

    pstat->start_time  = sigar_strtoul(ptr);
    pstat->start_time /= sigar->ticks;
    pstat->start_time += sigar->boot_time; /* seconds */
    pstat->start_time *= 1000; /* milliseconds */

    pstat->vsize = sigar_strtoul(ptr);
    pstat->rss   = pageshift(sigar_strtoul(ptr));

    return SIGAR_OK;
}

int sigar_proc_mem_get(sigar_t *sigar, sigar_pid_t pid,
                       sigar_proc_mem_t *procmem)
{
    char buffer[BUFSIZ], *ptr=buffer;
    int status = proc_stat_read(sigar, pid);
    linux_proc_stat_t *pstat = &sigar->last_proc_stat;

    procmem->vsize = pstat->vsize;
    procmem->rss   = pstat->rss;

    status = SIGAR_PROC_FILE2STR(buffer, pid, "/statm");

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

    procmem->size     = pageshift(sigar_strtoul(ptr));
    procmem->resident = pageshift(sigar_strtoul(ptr));
    procmem->share    = pageshift(sigar_strtoul(ptr));

    return SIGAR_OK;
}

int sigar_proc_cred_get(sigar_t *sigar, sigar_pid_t pid,
                        sigar_proc_cred_t *proccred)
{
    char buffer[BUFSIZ], *ptr;
    int status = SIGAR_PROC_FILE2STR(buffer, pid, PROC_PSTATUS);

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

    ptr = strstr(buffer, "\nUid:");
    ptr = sigar_skip_token(ptr);

    proccred->uid  = sigar_strtoul(ptr);
    proccred->euid = sigar_strtoul(ptr);

    ptr = strstr(ptr, "\nGid:");
    ptr = sigar_skip_token(ptr);

    proccred->gid  = sigar_strtoul(ptr);
    proccred->egid = sigar_strtoul(ptr);

    return SIGAR_OK;
}

int sigar_proc_time_get(sigar_t *sigar, sigar_pid_t pid,
                        sigar_proc_time_t *proctime)
{
    int status = proc_stat_read(sigar, pid);
    linux_proc_stat_t *pstat = &sigar->last_proc_stat;

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

    proctime->user = pstat->utime;
    proctime->sys  = pstat->stime;
    proctime->total = proctime->user + proctime->sys;
    proctime->start_time = pstat->start_time;

    return SIGAR_OK;
}

int sigar_proc_state_get(sigar_t *sigar, sigar_pid_t pid,
                         sigar_proc_state_t *procstate)
{
    int status = proc_stat_read(sigar, pid);
    linux_proc_stat_t *pstat = &sigar->last_proc_stat;

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

    memcpy(procstate->name, pstat->name, sizeof(procstate->name));
    procstate->state = pstat->state;

    procstate->ppid     = pstat->ppid;
    procstate->tty      = pstat->tty;
    procstate->priority = pstat->priority;
    procstate->nice     = pstat->nice;

    return SIGAR_OK;
}

int sigar_proc_args_get(sigar_t *sigar, sigar_pid_t pid,
                        sigar_proc_args_t *procargs)
{
    char buffer[BUFSIZ], *buf=NULL, *ptr;
    int fd, len, total=0;

    (void)SIGAR_PROC_FILENAME(buffer, pid, "/cmdline");

    if ((fd = open(buffer, O_RDONLY)) < 0) {
        if (errno == ENOENT) {
            return ESRCH;
        }
        return errno;
    }

    buffer[0] = '\0';

    /* XXX: possible to get rid of some mallocs here.
     * but, unlikely this will be called often so it
     * might not even matter much.
     */
    while ((len = read(fd, buffer, sizeof(buffer)-1)) > 0) {
        if (len == 0) {
            break;
        }
        if (buf) {
            buf = realloc(buf, total+len);
        }
        else {
            buf = malloc(len+1);
        }
        memcpy(buf+total, buffer, len);
        total += len;
    }

    close(fd);

    sigar_proc_args_create(procargs);

    //e.g. /proc/2/cmdline
    if (total == 0) {
        procargs->number = 0;
        return SIGAR_OK;
    }

    buf[total] = '\0';
    ptr = buf;

    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;
    }

    free(buf);

    return SIGAR_OK;
}

int sigar_proc_env_get(sigar_t *sigar, sigar_pid_t pid,
                       sigar_proc_env_t *procenv)
{
    int fd;
    char buffer[ARG_MAX]; /* XXX: ARG_MAX == 130k */
    char name[BUFSIZ];
    size_t len;
    char *ptr, *end;

    /* optimize if pid == $$ and type == ENV_KEY */
    SIGAR_PROC_ENV_KEY_LOOKUP();

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

    if ((fd = open(name, O_RDONLY)) < 0) {
        if (errno == ENOENT) {
            return ESRCH;
        }
        return errno;
    }

    len = read(fd, buffer, sizeof(buffer));

    close(fd);

    buffer[len] = '\0';
    ptr = buffer;

    end = buffer + len;
    while (ptr < end) {
        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 */
            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;
}

int sigar_proc_fd_get(sigar_t *sigar, sigar_pid_t pid,
                      sigar_proc_fd_t *procfd)
{
    int status =
        sigar_proc_fd_count(sigar, pid, &procfd->total);

    return status;
}

int sigar_proc_exe_get(sigar_t *sigar, sigar_pid_t pid,
                       sigar_proc_exe_t *procexe)
{
    int len;
    char name[BUFSIZ];

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

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

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

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

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

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

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

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

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

    return SIGAR_OK;
}

int sigar_proc_modules_get(sigar_t *sigar, sigar_pid_t pid,
                           sigar_proc_modules_t *procmods)
{
    FILE *fp;
    char buffer[BUFSIZ], *ptr;
    unsigned long inode, last_inode = 0;

    (void)SIGAR_PROC_FILENAME(buffer, pid, "/maps");

    if (!(fp = fopen(buffer, "r"))) {
        return errno;
    }

    while ((ptr = fgets(buffer, sizeof(buffer), fp))) {
        int len, status;
        /* skip region, flags, offset, dev */
        ptr = sigar_skip_multiple_token(ptr, 4);
        inode = sigar_strtoul(ptr);

        if ((inode == 0) || (inode == last_inode)) {
            last_inode = 0;
            continue;
        }

        last_inode = inode;
        SIGAR_SKIP_SPACE(ptr);
        len = strlen(ptr);
        ptr[len-1] = '\0'; /* chop \n */

        status =
            procmods->module_getter(procmods->data,
                                    ptr, len-1);

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

    return SIGAR_OK;
}

#include <mntent.h>
#include <sys/statfs.h>

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

    switch (*type) {
      case 'e':
        if (strnEQ(type, "ext", 3)) {
            fsp->type = SIGAR_FSTYPE_LOCAL_DISK;
        }
        break;
      case 'h':
        if (strEQ(type, "hpfs")) {
            fsp->type = SIGAR_FSTYPE_LOCAL_DISK;
        }
        break;
      case 'r':
        if (strEQ(type, "reiserfs")) {
            fsp->type = SIGAR_FSTYPE_LOCAL_DISK;
        }
        break;
      case 'x':
        if (strEQ(type, "xfs") || strEQ(type, "xiafs")) {
            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 mntent ent;
    char buf[1025]; /* buffer for strings within ent */
    FILE *fp;
    sigar_file_system_t *fsp;

    if (!(fp = setmntent(MOUNTED, "r"))) {
        return errno;
    }

    sigar_file_system_list_create(fslist);

    while (getmntent_r(fp, &ent, buf, sizeof(buf))) {
        SIGAR_FILE_SYSTEM_LIST_GROW(fslist);

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

        fsp->type = SIGAR_FSTYPE_UNKNOWN; /* unknown, will be set later */
        SIGAR_SSTRCPY(fsp->dir_name, ent.mnt_dir);
        SIGAR_SSTRCPY(fsp->dev_name, ent.mnt_fsname);
        SIGAR_SSTRCPY(fsp->sys_type_name, ent.mnt_type);
        sigar_fs_type_get(fsp);
    }

    endmntent(fp);

    return SIGAR_OK;
}

#include <sys/vfs.h>

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

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->files = buf.f_files;
    fsusage->free_files = buf.f_ffree;
    fsusage->use_percent = sigar_file_system_usage_calc_used(sigar, fsusage);

    return SIGAR_OK;
}

static SIGAR_INLINE char *cpu_info_strval(char *ptr)
{
    if ((ptr = strchr(ptr, ':'))) {
        ptr++;
        while (isspace (*ptr)) ptr++;
        return ptr;
    }
    return NULL;
}

static SIGAR_INLINE void cpu_info_strcpy(char *ptr, char *buf, int len)
{
    int slen;
    ptr = cpu_info_strval(ptr);
    if (!ptr) {
        return;
    }
    slen = strlen(ptr);
    strncpy(buf, ptr, len);
    buf[len] = '\0';
    if (slen < len) {
        buf[slen-1] = '\0'; /* rid \n */
    }
}

static int get_cpu_info(sigar_t *sigar, sigar_cpu_info_t *info,
                        FILE *fp, int *id)
{
    char buffer[BUFSIZ], *ptr;

    int found = 0, siblings = 0;

    *id = -1;

    while ((ptr = fgets(buffer, sizeof(buffer), fp))) {
        switch (*ptr) {
          case 'p': /* processor	: 0 */
            if (strnEQ(ptr, "processor", 9)) {
                found = 1;
            }
            else if (strnEQ(ptr, "physical id", 11)) {
                ptr = cpu_info_strval(ptr);
                *id = atoi(ptr);
            }
            break;
          case 'v':
            if (strnEQ(ptr, "vendor_id", 9)) {
                cpu_info_strcpy(ptr, info->vendor, sizeof(info->vendor));
                if (strEQ(info->vendor, "GenuineIntel")) {
                    SIGAR_SSTRCPY(info->vendor, "Intel");
                }
                else if (strEQ(info->vendor, "AuthenticAMD")) {
                    SIGAR_SSTRCPY(info->vendor, "AMD");
                }
            }
            break;
          case 'm':
            if (strnEQ(ptr, "model name", 10)) {
                cpu_info_strcpy(ptr, info->model, sizeof(info->model));
                sigar_cpu_model_adjust(sigar, info);
            }
            break;
          case 'c':
            if (strnEQ(ptr, "cpu MHz", 7)) {
                ptr = cpu_info_strval(ptr);
                info->mhz = atoi(ptr);
            }
            else if (strnEQ(ptr, "cache size", 10)) {
                ptr = cpu_info_strval(ptr);
                info->cache_size = sigar_strtoul(ptr);
            }
            break;
          case 's':
            /* this is horseshit.  why doesn't linux have a real api
             * like every other operation system.  if siblings == 1
             * then hyperthreading is disabled, so we shouldn't fold
             * the dups based on physical id attribute.
             */
            if (strnEQ(ptr, "siblings", 8)) {
                ptr = cpu_info_strval(ptr);
                siblings = atoi(ptr);
                if (siblings == 1) {
                    *id = -1;
                }
            }
            break;
          case 't':
            /* same as siblings, renamed in new kernels */
            if (strnEQ(ptr, "threads", 7)) {
                ptr = cpu_info_strval(ptr);
                siblings = atoi(ptr);
                if (siblings == 1) {
                    *id = -1;
                }
            }
            break;
           /* lone \n means end of info for this processor */
          case '\n':
            return found;
        }
    }

    return found;
}

int sigar_cpu_info_list_get(sigar_t *sigar,
                            sigar_cpu_info_list_t *cpu_infos)
{
    FILE *fp;
    int id, fake_id = -1;
    int cpu_id[36], cpu_ix=0;
    /* in the event that a box has > 36 cpus */
    int cpu_id_max = sizeof(cpu_id)/sizeof(int);

    if (!(fp = fopen("/proc/cpuinfo", "r"))) {
        return errno;
    }

    sigar->ht_enabled = 0; /* figure out below */

    sigar_cpu_info_list_create(cpu_infos);
    memset(&cpu_id[0], -1, sizeof(cpu_id));

    while (get_cpu_info(sigar, &cpu_infos->data[cpu_infos->number], fp, &id)) {
        fake_id++;

        if (id >= 0) {
            int i, fold=0;
            for (i=0; (i<cpu_ix) && (i<cpu_id_max); i++) {
                if (cpu_id[i] == id) {
                    fold = 1;
                    break;
                }
            }

            /* e.g. each Intel Xeon cpu is reported twice */
            /* fold dups based on physical id */
            if (fold) {
                sigar->ht_enabled = 1;
                sigar->lcpu = 2; /* XXX assume 2 for now */
                continue;
            }
            else {
                if (cpu_ix < cpu_id_max) {
                    cpu_id[cpu_ix++] = id;
                }
            }
        }
        else if (strEQ(cpu_infos->data[cpu_infos->number].model, "Xeon")) {
            /* Redhat AS 2.1 /proc/cpuinfo does not have any of the
             * attributes we use to detect hyperthreading, in this case
             * if model Xeon, assume HT enabled.  FUCK IT.
             */
            if (fake_id % 2) {
                sigar->ht_enabled = 1;
                sigar->lcpu = 2; /* XXX assume 2 for now */
                continue;
            }
        }

        ++cpu_infos->number;
        SIGAR_CPU_INFO_LIST_GROW(cpu_infos);
    }

    fclose(fp);

    return SIGAR_OK;
}

static unsigned int hex2int(const char *x)
{
    int i, ch;
    unsigned int j;

    for (i=0, j=0; i<8; i++) {
        ch = x[i];
        j <<= 4;
        if (isdigit(ch)) {
            j |= ch - '0';
        }
        else if (isupper(ch)) {
            j |= ch - ('A' - 10);
        }
        else {
            j |= ch - ('a' - 10);
        }
    }

    return j;
}

#define ROUTE_FMT "%16s %128s %128s %X %lld %lld %lld %128s %lld %lld %lld\n"
#define RTF_UP 0x0001

int sigar_net_route_list_get(sigar_t *sigar,
                             sigar_net_route_list_t *routelist)
{
    FILE *fp;
    char buffer[1024];
    char net_addr[128], gate_addr[128], mask_addr[128];
    int flags;
    sigar_net_route_t *route;

    routelist->size = routelist->number = 0;

    if (!(fp = fopen("/proc/net/route", "r"))) {
        return errno;
    }

    sigar_net_route_list_create(routelist);

    (void)fgets(buffer, sizeof(buffer), fp); /* skip header */
    while (fgets(buffer, sizeof(buffer), fp)) {
        int num;

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

        /* XXX rid sscanf */
        num = sscanf(buffer, ROUTE_FMT,
                     route->ifname, net_addr, gate_addr,
                     &flags, &route->refcnt, &route->use,
                     &route->metric, mask_addr,
                     &route->mtu, &route->window, &route->irtt);

        if ((num < 10) || !(flags & RTF_UP)) {
            --routelist->number;
            continue;
        }

        route->flags = flags;
        route->destination = hex2int(net_addr);
        route->gateway = hex2int(gate_addr);
        route->mask = hex2int(mask_addr);
    }

    fclose(fp);

    return SIGAR_OK;
}

int sigar_net_interface_stat_get(sigar_t *sigar, const char *name,
                                 sigar_net_interface_stat_t *ifstat)
{
    int found = 0;
    char buffer[BUFSIZ];
    FILE *fp = fopen("/proc/net/dev", "r");
    
    if (!fp) {
        return errno;
    }

    /* skip header */
    fgets(buffer, sizeof(buffer), fp);
    fgets(buffer, sizeof(buffer), fp);

    while (fgets(buffer, sizeof(buffer), fp)) {
        char *ptr, *dev;

        dev = buffer;
        while (isspace(*dev)) {
            dev++;
        }

        if (!(ptr = strchr(dev, ':'))) {
            continue;
        }

        *ptr++ = 0;

        if (!strEQ(dev, name)) {
            continue;
        }

        found = 1;
        ifstat->rx_bytes    = sigar_strtoul(ptr);
        ifstat->rx_packets  = sigar_strtoul(ptr);
        ifstat->rx_errors   = sigar_strtoul(ptr);
        ifstat->rx_dropped  = sigar_strtoul(ptr);
        ifstat->rx_overruns = sigar_strtoul(ptr);
        ifstat->rx_frame    = sigar_strtoul(ptr);

        /* skip: compressed multicast */
        ptr = sigar_skip_multiple_token(ptr, 2);

        ifstat->tx_bytes      = sigar_strtoul(ptr);
        ifstat->tx_packets    = sigar_strtoul(ptr);
        ifstat->tx_errors     = sigar_strtoul(ptr);
        ifstat->tx_dropped    = sigar_strtoul(ptr);
        ifstat->tx_overruns   = sigar_strtoul(ptr);
        ifstat->tx_collisions = sigar_strtoul(ptr);
        ifstat->tx_carrier    = sigar_strtoul(ptr);
        break;
    }

    fclose(fp);

    return found ? SIGAR_OK : ENXIO;
}

static SIGAR_INLINE int ip_format(char *buffer, int buflen, char *ptr)
{
    int alen = strlen(ptr);

    if (alen > 8) {
        struct in6_addr addr;
        int i;
        for (i=0; i<=3; i++, ptr+=8) {
            addr.s6_addr32[i] = hex2int(ptr);
        }
        if (!inet_ntop(AF_INET6, &addr, buffer, buflen)) {
            return errno;
        }
    }
    else {
        struct in_addr addr;
        addr.s_addr = hex2int(ptr);
        if (!inet_ntop(AF_INET, &addr, buffer, buflen)) {
            return errno;
        }
    }

    return SIGAR_OK;
}

typedef struct {
    sigar_net_connection_list_t *connlist;
    sigar_net_connection_t *conn;
    unsigned long port;
} net_conn_getter_t;

#define CONN_GET_DONE -2

static int proc_net_read(net_conn_getter_t *getter,
                         const char *fname,
                         int flags, int type)
{
    FILE *fp;
    char buffer[8192], *ptr;

    if (!(fp = fopen(fname, "r"))) {
        return errno;
    }

    fgets(buffer, sizeof(buffer), fp); /* skip header */

    while ((ptr = fgets(buffer, sizeof(buffer), fp))) {
        sigar_net_connection_t conn;
        char *port = NULL;
        char *laddr, *raddr;
        int status;

        ptr = sigar_skip_token(ptr); /* skip number */
        while (isspace(*ptr)) {
            ptr++;
        }

        port = strchr(ptr, ':');
        *port = '\0';
        ++port;

        conn.local_port = (strtoul(port, &port, 16) & 0xffff);
        laddr = ptr;

        ptr = port;
        while (isspace(*ptr)) {
            ptr++;
        }

        port = strchr(ptr, ':');
        *port = '\0';
        ++port;

        conn.remote_port = (strtoul(port, &port, 16) & 0xffff);
        raddr = ptr;

        ptr = port;
        while (isspace(*ptr)) {
            ptr++;
        }

        if (!((conn.remote_port && (flags & SIGAR_NETCONN_CLIENT)) ||
              (!conn.remote_port && (flags & SIGAR_NETCONN_SERVER))))
        {
            continue;
        }

        conn.type = type;

        status = ip_format(conn.local_address,
                           sizeof(conn.local_address),
                           laddr);

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

        status = ip_format(conn.remote_address,
                           sizeof(conn.remote_address),
                           raddr);

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

        /* XXX state, rx/tx queue info would be useful */
        ptr = sigar_skip_multiple_token(ptr, 4);
        conn.uid = sigar_strtoul(ptr);

        ptr = sigar_skip_token(ptr);

        conn.inode = sigar_strtoul(ptr);

        if (getter->connlist) {
            SIGAR_NET_CONNLIST_GROW(getter->connlist);
            memcpy(&getter->connlist->data[getter->connlist->number++],
                   &conn, sizeof(conn));
        }
        else {
            if ((getter->port == conn.local_port) &&
                (conn.remote_port == 0))
            {
                memcpy(getter->conn, &conn, sizeof(conn));
                fclose(fp);
                return CONN_GET_DONE;
            }
        }
    }

    fclose(fp);

    return SIGAR_OK;
}

static int net_conn_get(sigar_t *sigar,
                        net_conn_getter_t *getter,
                        int flags)
{
    int status;

    if (flags & SIGAR_NETCONN_TCP) {
        status = proc_net_read(getter,
                               "/proc/net/tcp",
                               flags, SIGAR_NETCONN_TCP);

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

        status = proc_net_read(getter,
                               "/proc/net/tcp6",
                               flags, SIGAR_NETCONN_TCP);

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

    if (flags & SIGAR_NETCONN_UDP) {
        status = proc_net_read(getter,
                               "/proc/net/udp",
                               flags, SIGAR_NETCONN_UDP);

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

        status = proc_net_read(getter,
                               "/proc/net/udp6",
                               flags, SIGAR_NETCONN_UDP);

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

    if (flags & SIGAR_NETCONN_RAW) {
        status = proc_net_read(getter,
                               "/proc/net/raw",
                               flags, SIGAR_NETCONN_RAW);

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

        status = proc_net_read(getter,
                               "/proc/net/raw6",
                               flags, SIGAR_NETCONN_RAW);

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

    /* XXX /proc/net/unix */

    return SIGAR_OK;
}

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

    sigar_net_connection_list_create(connlist);

    getter.conn = NULL;
    getter.connlist = connlist;

    status = net_conn_get(sigar, &getter, flags);

    if (status != SIGAR_OK) {
        sigar_net_connection_list_destroy(sigar, connlist);
    }

    return status;
}

static int sigar_net_connection_get(sigar_t *sigar,
                                    sigar_net_connection_t *netconn,
                                    unsigned long port,
                                    int flags)
{
    int status;
    net_conn_getter_t getter;

    getter.conn = netconn;
    getter.connlist = NULL;
    getter.port = port;

    status = net_conn_get(sigar, &getter, flags);

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

    return status;
}

int sigar_proc_port_get(sigar_t *sigar, unsigned long port, sigar_pid_t *pid)
{
    int status;
    sigar_net_connection_t netconn;
    DIR *dirp;
    struct dirent *ent, dbuf;

    SIGAR_ZERO(&netconn);
    *pid = 0;

    status = sigar_net_connection_get(sigar, &netconn, port,
                                      SIGAR_NETCONN_SERVER|
                                      SIGAR_NETCONN_TCP|SIGAR_NETCONN_UDP);

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

    if (netconn.local_port != port) {
        return SIGAR_OK; /* XXX or ENOENT? */
    }

    if (!(dirp = opendir("/proc"))) {
        return errno;
    }

    while (readdir_r(dirp, &dbuf, &ent) == 0) {
        DIR *fd_dirp;
        struct dirent *fd_ent, fd_dbuf;
        struct stat sb;
        char fd_name[BUFSIZ], pid_name[BUFSIZ];
        int len, slen;

        if (ent == NULL) {
            break;
        }

        if (!sigar_isdigit(*ent->d_name)) {
            continue;
        }

        /* sprintf(pid_name, "/proc/%s", ent->d_name) */
        memcpy(&pid_name[0], PROC_FS_ROOT, SSTRLEN(PROC_FS_ROOT));
        len = SSTRLEN(PROC_FS_ROOT);
        pid_name[len++] = '/';

        slen = strlen(ent->d_name);
        memcpy(&pid_name[len], ent->d_name, slen);
        len += slen;
        pid_name[len] = '\0';
        
        if (stat(pid_name, &sb) < 0) {
            continue;
        }
        if (sb.st_uid != netconn.uid) {
            continue;
        }

        /* sprintf(fd_name, "%s/fd", pid_name) */
        memcpy(&fd_name[0], pid_name, len);
        memcpy(&fd_name[len], "/fd", 3);
        fd_name[len+=3] = '\0';

        if (!(fd_dirp = opendir(fd_name))) {
            continue;
        }

        while (readdir_r(fd_dirp, &fd_dbuf, &fd_ent) == 0) {
            char fd_ent_name[BUFSIZ];

            if (fd_ent == NULL) {
                break;
            }

            if (!sigar_isdigit(*fd_ent->d_name)) {
                continue;
            }

            /* sprintf(fd_ent_name, "%s/%s", fd_name, fd_ent->d_name) */
            slen = strlen(fd_ent->d_name);
            memcpy(&fd_ent_name[0], fd_name, len);
            fd_ent_name[len] = '/';
            memcpy(&fd_ent_name[len+1], fd_ent->d_name, slen);
            fd_ent_name[len+1+slen] = '\0';

            if (stat(fd_ent_name, &sb) < 0) {
                continue;
            }

            if (sb.st_ino == netconn.inode) {
                closedir(fd_dirp);
                closedir(dirp);
                *pid = strtoul(ent->d_name, NULL, 10);
                return SIGAR_OK;
            }
            
        }

        closedir(fd_dirp);
    }

    closedir(dirp);

    return SIGAR_OK;
}