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 #define _USE_BSD
  24 #include <time.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include "polipo.h"
  28
  29 const time_t time_t_max = ((time_t)~(1U << 31));
  30
  31 static inline int
  32 d2i(char c)
  33 {
  34     if(c >= '0' && c <= '9')
  35         return c - '0';
  36     else
  37         return -1;
  38 }
  39
  40 static int
  41 parse_int(const char *buf, int i, int len, int *val_return)
  42 {
  43     int val, d;
  44
  45     if(i >= len)
  46         return -1;
  47
  48     val = d2i(buf[i]);
  49     if(val < 0)
  50         return -1;
  51     else
  52         i++;
  53
  54     while(i < len) {
  55         d = d2i(buf[i]);
  56         if(d < 0)
  57             break;
  58         val = val * 10 + d;
  59         i++;
  60     }
  61     *val_return = val;
  62     return i;
  63 }
  64
  65 static const char month_names[12][3] = {
  66     "jan", "feb", "mar", "apr", "may", "jun",
  67     "jul", "aug", "sep", "oct", "nov", "dec",
  68 };
  69
  70 static int
  71 skip_word(const char *buf, int i, int len)
  72 {
  73     if(i >= len)
  74         return -1;
  75
  76     if(!letter(buf[i]))
  77        return -1;
  78
  79     while(i < len) {
  80         if(!letter(buf[i]))
  81             break;
  82         i++;
  83     }
  84
  85     return i;
  86 }
  87
  88 static int
  89 parse_month(const char *buf, int i, int len, int *val_return)
  90 {
  91     int j, k, l;
  92     j = skip_word(buf, i, len);
  93     if(j != i + 3)
  94         return -1;
  95     for(k = 0; k < 12; k++) {
  96         for(l = 0; l < 3; l++) {
  97             if(lwr(buf[i + l]) != month_names[k][l])
  98                 break;
  99         }
 100         if(l == 3)
 101             break;
 102     }
 103     if(k >= 12)
 104         return -1;
 105     *val_return = k;
 106     return j;
 107 }
 108
 109 static int
 110 issep(char c)
 111 {
 112     return c == ' ' || c == '\t' || c == ',' || c == ':' || c == '-';
 113 }
 114
 115 int
 116 skip_separator(const char *buf, int i, int len)
 117 {
 118     if(i >= len)
 119         return -1;
 120
 121     if(issep(buf[i]))
 122         i++;
 123     else
 124         return -1;
 125
 126     while(i < len) {
 127         if(issep(buf[i]))
 128             i++;
 129         else
 130             break;
 131     }
 132     return i;
 133 }
 134
 135 int
 136 parse_time(const char *buf, int offset, int len, time_t *time_return)
 137 {
 138     struct tm tm;
 139     time_t t;
 140     int i = offset;
 141
 142     i = skip_word(buf, i, len); if(i < 0) return -1;
 143     i = skip_separator(buf, i, len); if(i < 0) return -1;
 144
 145     if(i >= len)
 146         return -1;
 147
 148     if(d2i(buf[i]) >= 0) {
 149         i = parse_int(buf, i, len, &tm.tm_mday); if(i < 0) return -1;
 150         i = skip_separator(buf, i, len); if(i < 0) return -1;
 151         i = parse_month(buf, i, len, &tm.tm_mon); if(i < 0) return -1;
 152         i = skip_separator(buf, i, len); if(i < 0) return -1;
 153         i = parse_int(buf, i, len, &tm.tm_year); if(i < 0) return -1;
 154         if(tm.tm_year < 100)
 155             tm.tm_year += 1900;
 156         if(tm.tm_year < 1937)
 157             tm.tm_year += 100;
 158         if(tm.tm_year < 1937)
 159             return -1;
 160
 161         i = skip_separator(buf, i, len); if(i < 0) return -1;
 162         i = parse_int(buf, i, len, &tm.tm_hour); if(i < 0) return -1;
 163         i = skip_separator(buf, i, len); if(i < 0) return -1;
 164         i = parse_int(buf, i, len, &tm.tm_min); if(i < 0) return -1;
 165         i = skip_separator(buf, i, len); if(i < 0) return -1;
 166         i = parse_int(buf, i, len, &tm.tm_sec); if(i < 0) return -1;
 167         i = skip_separator(buf, i, len); if(i < 0) return -1;
 168         i = skip_word(buf, i, len); if(i < 0) return -1;
 169     } else {                    /* funny American format */
 170         i = parse_month(buf, i, len, &tm.tm_mon); 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_mday); 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_hour); 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_min); if(i < 0) return -1;
 177         i = skip_separator(buf, i, len); if(i < 0) return -1;
 178         i = parse_int(buf, i, len, &tm.tm_sec); if(i < 0) return -1;
 179         i = skip_separator(buf, i, len); if(i < 0) return -1;
 180         i = parse_int(buf, i, len, &tm.tm_year); if(i < 0) return -1;
 181         if(tm.tm_year < 100)
 182             tm.tm_year += 1900;
 183         if(tm.tm_year < 1937)
 184             tm.tm_year += 100;
 185         if(tm.tm_year < 1937 || tm.tm_year > 2040)
 186             return -1;
 187     }
 188
 189     if(tm.tm_year < 2038) {
 190         tm.tm_year -= 1900;
 191         tm.tm_isdst = -1;
 192         t = mktime_gmt(&tm);
 193         if(t == -1)
 194             return -1;
 195     } else {
 196         t = time_t_max;
 197     }
 198
 199     *time_return = t;
 200     return i;
 201 }
 202
 203 int
 204 format_time(char *buf, int i, int len, time_t t)
 205 {
 206     struct tm *tm;
 207     int rc;
 208
 209     if(i < 0 || i > len)
 210         return -1;
 211
 212     tm = gmtime(&t);
 213     if(tm == NULL)
 214         return -1;
 215     rc = strftime(buf + i, len - i, "%a, %d %b %Y %H:%M:%S GMT", tm);
 216     if(rc <= 0)                 /* yes, that's <= */
 217         return -1;
 218     return i + rc;
 219 }