parse_time.c

   1 /*
   2 Copyright (c) 2003-2006 by Juliusz Chroboczek
   3
   4 Permission is hereby granted, free of charge, to any person obtaining a copy
   5 of this software and associated documentation files (the "Software"), to deal
   6 in the Software without restriction, including without limitation the rights
   7 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8 copies of the Software, and to permit persons to whom the Software is
   9 furnished to do so, subject to the following conditions:
  10
  11 The above copyright notice and this permission notice shall be included in
  12 all copies or substantial portions of the Software.
  13
  14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  17 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20 THE SOFTWARE.
  21 */
  22
  23 #include "polipo.h"
  24
  25 const time_t time_t_max = ((time_t)~(1U << 31));
  26
  27 static inline int
  28 d2i(char c)
  29 {
  30     if(c >= '0' && c <= '9')
  31         return c - '0';
  32     else
  33         return -1;
  34 }
  35
  36 static int
  37 parse_int(const char *buf, int i, int len, int *val_return)
  38 {
  39     int val, d;
  40
  41     if(i >= len)
  42         return -1;
  43
  44     val = d2i(buf[i]);
  45     if(val < 0)
  46         return -1;
  47     else
  48         i++;
  49
  50     while(i < len) {
  51         d = d2i(buf[i]);
  52         if(d < 0)
  53             break;
  54         val = val * 10 + d;
  55         i++;
  56     }
  57     *val_return = val;
  58     return i;
  59 }
  60
  61 static const char month_names[12][3] = {
  62     "jan", "feb", "mar", "apr", "may", "jun",
  63     "jul", "aug", "sep", "oct", "nov", "dec",
  64 };
  65
  66 static int
  67 skip_word(const char *buf, int i, int len)
  68 {
  69     if(i >= len)
  70         return -1;
  71
  72     if(!letter(buf[i]))
  73        return -1;
  74
  75     while(i < len) {
  76         if(!letter(buf[i]))
  77             break;
  78         i++;
  79     }
  80
  81     return i;
  82 }
  83
  84 static int
  85 parse_month(const char *buf, int i, int len, int *val_return)
  86 {
  87     int j, k, l;
  88     j = skip_word(buf, i, len);
  89     if(j != i + 3)
  90         return -1;
  91     for(k = 0; k < 12; k++) {
  92         for(l = 0; l < 3; l++) {
  93             if(lwr(buf[i + l]) != month_names[k][l])
  94                 break;
  95         }
  96         if(l == 3)
  97             break;
  98     }
  99     if(k >= 12)
 100         return -1;
 101     *val_return = k;
 102     return j;
 103 }
 104
 105 static int
 106 issep(char c)
 107 {
 108     return c == ' ' || c == '\t' || c == ',' || c == ':' || c == '-';
 109 }
 110
 111 int
 112 skip_separator(const char *buf, int i, int len)
 113 {
 114     if(i >= len)
 115         return -1;
 116
 117     if(issep(buf[i]))
 118         i++;
 119     else
 120         return -1;
 121
 122     while(i < len) {
 123         if(issep(buf[i]))
 124             i++;
 125         else
 126             break;
 127     }
 128     return i;
 129 }
 130
 131 int
 132 parse_time(const char *buf, int offset, int len, time_t *time_return)
 133 {
 134     struct tm tm;
 135     time_t t;
 136     int i = offset;
 137
 138     i = skip_word(buf, i, len); if(i < 0) return -1;
 139     i = skip_separator(buf, i, len); if(i < 0) return -1;
 140
 141     if(i >= len)
 142         return -1;
 143
 144     if(d2i(buf[i]) >= 0) {
 145         i = parse_int(buf, i, len, &tm.tm_mday); if(i < 0) return -1;
 146         i = skip_separator(buf, i, len); if(i < 0) return -1;
 147         i = parse_month(buf, i, len, &tm.tm_mon); if(i < 0) return -1;
 148         i = skip_separator(buf, i, len); if(i < 0) return -1;
 149         i = parse_int(buf, i, len, &tm.tm_year); if(i < 0) return -1;
 150         if(tm.tm_year < 100)
 151             tm.tm_year += 1900;
 152         if(tm.tm_year < 1937)
 153             tm.tm_year += 100;
 154         if(tm.tm_year < 1937)
 155             return -1;
 156
 157         i = skip_separator(buf, i, len); if(i < 0) return -1;
 158         i = parse_int(buf, i, len, &tm.tm_hour); if(i < 0) return -1;
 159         i = skip_separator(buf, i, len); if(i < 0) return -1;
 160         i = parse_int(buf, i, len, &tm.tm_min); if(i < 0) return -1;
 161         i = skip_separator(buf, i, len); if(i < 0) return -1;
 162         i = parse_int(buf, i, len, &tm.tm_sec); if(i < 0) return -1;
 163         i = skip_separator(buf, i, len); if(i < 0) return -1;
 164         i = skip_word(buf, i, len); if(i < 0) return -1;
 165     } else {                    /* funny American format */
 166         i = parse_month(buf, i, len, &tm.tm_mon); if(i < 0) return -1;
 167         i = skip_separator(buf, i, len); if(i < 0) return -1;
 168         i = parse_int(buf, i, len, &tm.tm_mday); if(i < 0) return -1;
 169         i = skip_separator(buf, i, len); if(i < 0) return -1;
 170         i = parse_int(buf, i, len, &tm.tm_hour); if(i < 0) return -1;
 171         i = skip_separator(buf, i, len); if(i < 0) return -1;
 172         i = parse_int(buf, i, len, &tm.tm_min); if(i < 0) return -1;
 173         i = skip_separator(buf, i, len); if(i < 0) return -1;
 174         i = parse_int(buf, i, len, &tm.tm_sec); if(i < 0) return -1;
 175         i = skip_separator(buf, i, len); if(i < 0) return -1;
 176         i = parse_int(buf, i, len, &tm.tm_year); if(i < 0) return -1;
 177         if(tm.tm_year < 100)
 178             tm.tm_year += 1900;
 179         if(tm.tm_year < 1937)
 180             tm.tm_year += 100;
 181         if(tm.tm_year < 1937 || tm.tm_year > 2040)
 182             return -1;
 183     }
 184
 185     if(tm.tm_year < 2038) {
 186         tm.tm_year -= 1900;
 187         tm.tm_isdst = -1;
 188         t = mktime_gmt(&tm);
 189         if(t == -1)
 190             return -1;
 191     } else {
 192         t = time_t_max;
 193     }
 194
 195     *time_return = t;
 196     return i;
 197 }
 198
 199 int
 200 format_time(char *buf, int i, int len, time_t t)
 201 {
 202     struct tm *tm;
 203     int rc;
 204
 205     if(i < 0 || i > len)
 206         return -1;
 207
 208     tm = gmtime(&t);
 209     if(tm == NULL)
 210         return -1;
 211     rc = strftime(buf + i, len - i, "%a, %d %b %Y %H:%M:%S GMT", tm);
 212     if(rc <= 0)                 /* yes, that's <= */
 213         return -1;
 214     return i + rc;
 215 }