plugins/old-stats/mail-stats-fill.c

	mail-stats-fill.c revision 8c533d1c49f47b7919de72c794abe9d2e0660ebd
/* Copyright (c) 2011-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "time-util.h"
#include "restrict-access.h"
#include "stats-plugin.h"
#include "mail-stats.h"

#include <sys/resource.h>

#define PROC_IO_PATH "/proc/self/io"

static bool proc_io_disabled = FALSE;
static int proc_io_fd = -1;

static int
process_io_buffer_parse(const char *buf, struct mail_stats *stats)
{
    const char *const *tmp;

    tmp = t_strsplit(buf, "\n");
    for (; *tmp != NULL; tmp++) {
        if (strncmp(*tmp, "rchar: ", 7) == 0) {
            if (str_to_uint64(*tmp + 7, &stats->read_bytes) < 0)
                return -1;
        } else if (strncmp(*tmp, "wchar: ", 7) == 0) {
            if (str_to_uint64(*tmp + 7, &stats->write_bytes) < 0)
                return -1;
        } else if (strncmp(*tmp, "syscr: ", 7) == 0) {
            if (str_to_uint32(*tmp + 7, &stats->read_count) < 0)
                return -1;
        } else if (strncmp(*tmp, "syscw: ", 7) == 0) {
            if (str_to_uint32(*tmp + 7, &stats->write_count) < 0)
                return -1;
        }
    }
    return 0;
}

static int process_io_open(void)
{
    uid_t uid;

    if (proc_io_fd != -1)
        return proc_io_fd;

    if (proc_io_disabled)
        return -1;

    bool dumpable = restrict_access_get_dumpable();
    if (!dumpable)
        restrict_access_set_dumpable(TRUE);
    proc_io_fd = open(PROC_IO_PATH, O_RDONLY);
    if (proc_io_fd == -1 && errno == EACCES) {
        /* kludge: if we're running with permissions temporarily
           dropped, get them temporarily back so we can open
           /proc/self/io. */
        uid = geteuid();
        if (seteuid(0) == 0) {
            proc_io_fd = open(PROC_IO_PATH, O_RDONLY);
            if (seteuid(uid) < 0) {
                /* oops, this is bad */
                i_fatal("stats: seteuid(%s) failed", dec2str(uid));
            }
        }
        errno = EACCES;
    }
    if (!dumpable)
        restrict_access_set_dumpable(FALSE);
    if (proc_io_fd == -1) {
        /* ignore access errors too, certain security options can
           prevent root access to this file when not owned by root */
        if (errno != ENOENT && errno != EACCES)
            i_error("open(%s) failed: %m", PROC_IO_PATH);
        proc_io_disabled = TRUE;
        return -1;
    }
    return proc_io_fd;
}

static void process_read_io_stats(struct mail_stats *stats)
{
    char buf[1024];
    int fd, ret;

    if ((fd = process_io_open()) == -1)
        return;

    ret = pread(fd, buf, sizeof(buf), 0);
    if (ret <= 0) {
        if (ret == -1)
            i_error("read(%s) failed: %m", PROC_IO_PATH);
        else
            i_error("read(%s) returned EOF", PROC_IO_PATH);
    } else if (ret == sizeof(buf)) {
        /* just shouldn't happen.. */
        i_error("%s is larger than expected", PROC_IO_PATH);
        proc_io_disabled = TRUE;
    } else {
        buf[ret] = '\0';
        T_BEGIN {
            if (process_io_buffer_parse(buf, stats) < 0) {
                i_error("Invalid input in file %s",
                    PROC_IO_PATH);
                proc_io_disabled = TRUE;
            }
        } T_END;
    }
}

static void
user_trans_stats_get(struct stats_user *suser, struct mail_stats *dest_r)
{
    struct stats_transaction_context *strans;

    mail_stats_add_transaction(dest_r, &suser->finished_transaction_stats);
    for (strans = suser->transactions; strans != NULL; strans = strans->next)
        mail_stats_add_transaction(dest_r, &strans->trans->stats);
}

void mail_stats_fill(struct stats_user *suser, struct mail_stats *stats_r)
{
    static bool getrusage_broken = FALSE;
    static struct rusage prev_usage;
    struct rusage usage;

    i_zero(stats_r);
    /* cputime */
    if (getrusage(RUSAGE_SELF, &usage) < 0) {
        if (!getrusage_broken) {
            i_error("getrusage() failed: %m");
            getrusage_broken = TRUE;
        }
        usage = prev_usage;
    } else if (timeval_diff_usecs(&usage.ru_stime, &prev_usage.ru_stime) < 0) {
        /* This seems to be a Linux bug. */
        usage.ru_stime = prev_usage.ru_stime;
    }
    prev_usage = usage;

    stats_r->user_cpu = usage.ru_utime;
    stats_r->sys_cpu = usage.ru_stime;
    stats_r->min_faults = usage.ru_minflt;
    stats_r->maj_faults = usage.ru_majflt;
    stats_r->vol_cs = usage.ru_nvcsw;
    stats_r->invol_cs = usage.ru_nivcsw;
    stats_r->disk_input = (unsigned long long)usage.ru_inblock * 512ULL;
    stats_r->disk_output = (unsigned long long)usage.ru_oublock * 512ULL;
    (void)gettimeofday(&stats_r->clock_time, NULL);
    process_read_io_stats(stats_r);
    user_trans_stats_get(suser, stats_r);
}

void mail_stats_fill_global_deinit(void)
{
    i_close_fd(&proc_io_fd);
}