unix4lyfe git - darkstat-debian/blob - daylog.c

   1 /* darkstat 3
   2  * copyright (c) 2007-2011 Emil Mikulic.
   3  *
   4  * daylog.c: daily usage log
   5  *
   6  * You may use, modify and redistribute this file under the terms of the
   7  * GNU General Public License version 2. (see COPYING.GPL)
   8  */
   9
  10 #define _GNU_SOURCE 1 /* for O_NOFOLLOW on Linux */
  11
  12 #include <sys/types.h>
  13 #include <assert.h>
  14 #include <fcntl.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <unistd.h>
  18
  19 #include "err.h"
  20 #include "daylog.h"
  21 #include "str.h"
  22 #include "now.h"
  23
  24 static const char *daylog_fn = NULL;
  25 static time_t today_time, tomorrow_time;
  26 static uint64_t bytes_in, bytes_out, pkts_in, pkts_out;
  27
  28 #define DAYLOG_DATE_LEN 26 /* strlen("1900-01-01 00:00:00 +1234") + 1 */
  29 static char datebuf[DAYLOG_DATE_LEN];
  30
  31 static char *
  32 fmt_date(const time_t when)
  33 {
  34     time_t tmp = when;
  35     if (strftime(datebuf, DAYLOG_DATE_LEN,
  36         "%Y-%m-%d %H:%M:%S %z", localtime(&tmp) ) == 0)
  37             errx(1, "strftime() failed in fmt_date()");
  38     return (datebuf);
  39 }
  40
  41 /* Given some time today, find the first second of tomorrow. */
  42 static time_t
  43 tomorrow(const time_t today)
  44 {
  45    time_t tmp = today;
  46    struct tm tm, *lt;
  47
  48    lt = localtime(&tmp);
  49    memcpy(&tm, lt, sizeof(tm));
  50    tm.tm_sec = 0;
  51    tm.tm_min = 0;
  52    tm.tm_hour = 0;
  53    tm.tm_mday = lt->tm_mday + 1; /* tomorrow */
  54    return mktime(&tm);
  55 }
  56
  57 static int
  58 daylog_open(void)
  59 {
  60    return open(daylog_fn, O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW, 0600);
  61 }
  62
  63 static void
  64 daylog_emit(void)
  65 {
  66    int fd = daylog_open();
  67
  68    if (fd != -1) {
  69       struct str *buf = str_make();
  70       char *s;
  71       size_t len;
  72       str_appendf(buf, "%s|%u|%qu|%qu|%qu|%qu\n",
  73          fmt_date(today_time), (unsigned int)today_time,
  74          bytes_in, bytes_out, pkts_in, pkts_out);
  75       str_extract(buf, &len, &s);
  76
  77       (void)write(fd, s, len); /* ignore write errors */
  78       close(fd);
  79       free(s);
  80    }
  81 }
  82
  83 void
  84 daylog_init(const char *filename)
  85 {
  86    int fd;
  87    struct str *buf;
  88    char *s;
  89    size_t len;
  90
  91    daylog_fn = filename;
  92    today_time = time(NULL);
  93    tomorrow_time = tomorrow(today_time);
  94    verbosef("today is %u, tomorrow is %u",
  95       (unsigned int)today_time, (unsigned int)tomorrow_time);
  96    bytes_in = bytes_out = pkts_in = pkts_out = 0;
  97
  98    fd = daylog_open();
  99    if (fd == -1)
 100       err(1, "couldn't open(\"%s\") for append", filename);
 101
 102    buf = str_make();
 103    str_appendf(buf, "# logging started at %s (%u)\n",
 104       fmt_date(today_time), (unsigned int)today_time);
 105    str_extract(buf, &len, &s);
 106    (void)write(fd, s, len); /* ignore write errors */
 107    close(fd);
 108    free(s);
 109 }
 110
 111 void daylog_free(void)
 112 {
 113    int fd;
 114    struct str *buf;
 115    char *s;
 116    size_t len;
 117
 118    today_time = time(NULL);
 119
 120    /* Emit what's currently accumulated. */
 121    daylog_emit();
 122
 123    fd = daylog_open();
 124    if (fd == -1) return;
 125
 126    buf = str_make();
 127    str_appendf(buf, "# logging stopped at %s (%u)\n",
 128       fmt_date(today_time), (unsigned int)today_time);
 129    str_extract(buf, &len, &s);
 130    (void)write(fd, s, len); /* ignore write errors */
 131    close(fd);
 132    free(s);
 133 }
 134
 135 void
 136 daylog_acct(uint64_t amount, enum graph_dir dir)
 137 {
 138    if (daylog_fn == NULL) return; /* disabled */
 139
 140    /* Check if we need to rotate. */
 141    if (now >= tomorrow_time) {
 142       daylog_emit();
 143
 144       today_time = now;
 145       tomorrow_time = tomorrow(today_time);
 146       bytes_in = bytes_out = pkts_in = pkts_out = 0;
 147       verbosef("rotated daylog, tomorrow = %u",
 148          (unsigned int)tomorrow_time);
 149    }
 150
 151    /* Accounting. */
 152    if (dir == GRAPH_IN) {
 153       bytes_in += amount;
 154       pkts_in++;
 155    } else {
 156       assert(dir == GRAPH_OUT);
 157       bytes_out += amount;
 158       pkts_out++;
 159    }
 160 }
 161
 162 /* vim:set ts=3 sw=3 tw=78 et: */