diff options
Diffstat (limited to 'src/lib-imap/imap-date.c')
| -rw-r--r-- | src/lib-imap/imap-date.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/src/lib-imap/imap-date.c b/src/lib-imap/imap-date.c new file mode 100644 index 0000000..2e5569a --- /dev/null +++ b/src/lib-imap/imap-date.c @@ -0,0 +1,247 @@ +/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */ + +#include "lib.h" +#include "utc-offset.h" +#include "utc-mktime.h" +#include "imap-date.h" + +#include <ctype.h> + +static const char *month_names[] = { + "Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" +}; + +static int parse_timezone(const char *str) +{ + int offset; + + /* +|-zone */ + if ((*str != '+' && *str != '-') || + !i_isdigit(str[1]) || !i_isdigit(str[2]) || + !i_isdigit(str[3]) || !i_isdigit(str[4])) + return 0; + + offset = (str[1]-'0') * 10*60 + (str[2]-'0') * 60 + + (str[3]-'0') * 10 + (str[4]-'0'); + return *str == '+' ? offset : -offset; +} + +static const char *imap_parse_date_internal(const char *str, struct tm *tm) +{ + int i; + + if (str == NULL || *str == '\0') + return NULL; + + i_zero(tm); + + /* "dd-mon-yyyy [hh:mi:ss +|-zone]" + dd is 1-2 digits and may be prefixed with space or zero. */ + + if (str[0] == ' ') { + /* " d-..." */ + str++; + } + + if (!(i_isdigit(str[0]) && (str[1] == '-' || + (i_isdigit(str[1]) && str[2] == '-')))) + return NULL; + + tm->tm_mday = (str[0]-'0'); + if (str[1] == '-') + str += 2; + else { + tm->tm_mday = (tm->tm_mday * 10) + (str[1]-'0'); + str += 3; + } + + /* month name */ + for (i = 0; i < 12; i++) { + if (strncasecmp(month_names[i], str, 3) == 0) { + tm->tm_mon = i; + break; + } + } + if (i == 12 || str[3] != '-') + return NULL; + str += 4; + + /* yyyy */ + if (!i_isdigit(str[0]) || !i_isdigit(str[1]) || + !i_isdigit(str[2]) || !i_isdigit(str[3])) + return NULL; + + tm->tm_year = (str[0]-'0') * 1000 + (str[1]-'0') * 100 + + (str[2]-'0') * 10 + (str[3]-'0') - 1900; + + str += 4; + return str; +} + +static bool imap_mktime(struct tm *tm, time_t *time_r) +{ + *time_r = utc_mktime(tm); + if (*time_r != (time_t)-1) + return TRUE; + + /* the date is outside valid range for time_t. it might still be + technically valid though, so try to handle this case. + with 64bit time_t the full 0..9999 year range is valid. */ + if (tm->tm_year <= 100) { + /* too old. time_t can be signed or unsigned, handle + both cases. */ + *time_r = (time_t)-1 < (int)0 ? INT_MIN : 0; + } else { + /* too high. return the highest allowed value. + we shouldn't get here with 64bit time_t, + but handle that anyway. */ +#if (TIME_T_MAX_BITS == 32 || TIME_T_MAX_BITS == 64) + *time_r = (1UL << (TIME_T_MAX_BITS-1)) - 1; +#else + *time_r = (1UL << TIME_T_MAX_BITS) - 1; +#endif + } + return FALSE; +} + +bool imap_parse_date(const char *str, time_t *timestamp_r) +{ + struct tm tm; + + str = imap_parse_date_internal(str, &tm); + if (str == NULL || str[0] != '\0') + return FALSE; + + tm.tm_isdst = -1; + (void)imap_mktime(&tm, timestamp_r); + return TRUE; +} + +bool imap_parse_datetime(const char *str, time_t *timestamp_r, + int *timezone_offset_r) +{ + struct tm tm; + + str = imap_parse_date_internal(str, &tm); + if (str == NULL) + return FALSE; + + if (str[0] != ' ') + return FALSE; + str++; + + /* hh: */ + if (!i_isdigit(str[0]) || !i_isdigit(str[1]) || str[2] != ':') + return FALSE; + tm.tm_hour = (str[0]-'0') * 10 + (str[1]-'0'); + str += 3; + + /* mm: */ + if (!i_isdigit(str[0]) || !i_isdigit(str[1]) || str[2] != ':') + return FALSE; + tm.tm_min = (str[0]-'0') * 10 + (str[1]-'0'); + str += 3; + + /* ss */ + if (!i_isdigit(str[0]) || !i_isdigit(str[1]) || str[2] != ' ') + return FALSE; + tm.tm_sec = (str[0]-'0') * 10 + (str[1]-'0'); + str += 3; + + /* timezone */ + *timezone_offset_r = parse_timezone(str); + + tm.tm_isdst = -1; + if (imap_mktime(&tm, timestamp_r)) + *timestamp_r -= *timezone_offset_r * 60; + return TRUE; +} + +static void imap_to_date_tm(char buf[11], const struct tm *tm) +{ + int year; + + /* dd-mon- */ + buf[0] = (tm->tm_mday / 10) + '0'; + buf[1] = (tm->tm_mday % 10) + '0'; + buf[2] = '-'; + memcpy(buf+3, month_names[tm->tm_mon], 3); + buf[6] = '-'; + + /* yyyy */ + year = tm->tm_year + 1900; + buf[7] = (year / 1000) + '0'; + buf[8] = ((year / 100) % 10) + '0'; + buf[9] = ((year / 10) % 10) + '0'; + buf[10] = (year % 10) + '0'; +} + +static const char * +imap_to_datetime_tm(const struct tm *tm, int timezone_offset) +{ + char *buf; + + /* @UNSAFE: but faster than t_strdup_printf() call.. */ + buf = t_malloc0(27); + imap_to_date_tm(buf, tm); + buf[11] = ' '; + + /* hh:mi:ss */ + buf[12] = (tm->tm_hour / 10) + '0'; + buf[13] = (tm->tm_hour % 10) + '0'; + buf[14] = ':'; + buf[15] = (tm->tm_min / 10) + '0'; + buf[16] = (tm->tm_min % 10) + '0'; + buf[17] = ':'; + buf[18] = (tm->tm_sec / 10) + '0'; + buf[19] = (tm->tm_sec % 10) + '0'; + buf[20] = ' '; + + /* timezone */ + if (timezone_offset >= 0) + buf[21] = '+'; + else { + buf[21] = '-'; + timezone_offset = -timezone_offset; + } + buf[22] = (timezone_offset / 600) + '0'; + buf[23] = ((timezone_offset / 60) % 10) + '0'; + buf[24] = ((timezone_offset % 60) / 10) + '0'; + buf[25] = (timezone_offset % 10) + '0'; + buf[26] = '\0'; + + return buf; +} + +const char *imap_to_datetime(time_t timestamp) +{ + struct tm *tm; + int timezone_offset; + + tm = localtime(×tamp); + timezone_offset = utc_offset(tm, timestamp); + return imap_to_datetime_tm(tm, timezone_offset); +} + +const char *imap_to_datetime_tz(time_t timestamp, int timezone_offset) +{ + const struct tm *tm; + time_t adjusted = timestamp + timezone_offset*60; + + tm = gmtime(&adjusted); + return imap_to_datetime_tm(tm, timezone_offset); +} + +bool imap_to_date(time_t timestamp, const char **str_r) +{ + const struct tm *tm; + char *buf; + + tm = localtime(×tamp); + + buf = t_malloc0(12); + imap_to_date_tm(buf, tm); + *str_r = buf; + return tm->tm_hour == 0 && tm->tm_min == 0 && tm->tm_sec == 0; +} |