+/*************************************************
+* Parse a RFC 2822 Time *
+*************************************************/
+
+/* Parse the time part of a RFC 2822 date-time, extracting the
+ hour, minute, second and timezone.
+
+Arguments:
+ str pointer to the start of the time
+ h pointer to the resulting hour
+ m pointer to the resulting minute
+ s pointer to the resulting second
+ z pointer to the resulting timezone (offset in seconds)
+
+Returns: points after the processed time or NULL on error
+*/
+
+static const uschar *
+parse_time(const uschar *str, int *h, int *m, int *s, int *z)
+{
+/*
+time = time-of-day FWS zone
+
+time-of-day = hour ":" minute [ ":" second ]
+
+hour = 2DIGIT / obs-hour
+
+obs-hour = [CFWS] 2DIGIT [CFWS]
+
+minute = 2DIGIT / obs-minute
+
+obs-minute = [CFWS] 2DIGIT [CFWS]
+
+second = 2DIGIT / obs-second
+
+obs-second = [CFWS] 2DIGIT [CFWS]
+
+zone = (( "+" / "-" ) 4DIGIT) / obs-zone
+
+obs-zone = "UT" / "GMT" / ; Universal Time
+ ; North American UT
+ ; offsets
+ "EST" / "EDT" / ; Eastern: - 5/ - 4
+ "CST" / "CDT" / ; Central: - 6/ - 5
+ "MST" / "MDT" / ; Mountain: - 7/ - 6
+ "PST" / "PDT" / ; Pacific: - 8/ - 7
+
+ %d65-73 / ; Military zones - "A"
+ %d75-90 / ; through "I" and "K"
+ %d97-105 / ; through "Z", both
+ %d107-122 ; upper and lower case
+*/
+
+const uschar * c;
+
+str = skip_comment(str);
+if ((str = parse_number(str,h,2)) == NULL) return NULL;
+str = skip_comment(str);
+if (*str!=':') return NULL;
+++str;
+str = skip_comment(str);
+if ((str = parse_number(str,m,2)) == NULL) return NULL;
+c = skip_comment(str);
+if (*str == ':')
+ {
+ ++str;
+ str = skip_comment(str);
+ if ((str = parse_number(str,s,2)) == NULL) return NULL;
+ c = skip_comment(str);
+ }
+if (c == str) return NULL;
+else str=c;
+if (*str == '+' || *str == '-')
+ {
+ int neg;
+
+ neg = (*str == '-');
+ ++str;
+ if ((str = parse_number(str,z,4)) == NULL) return NULL;
+ *z = (*z/100)*3600+(*z%100)*60;
+ if (neg) *z = -*z;
+ }
+else
+ {
+ char zone[5];
+ struct { const char *name; int off; } zone_name[10] =
+ { {"gmt",0}, {"ut",0}, {"est",-5}, {"edt",-4}, {"cst",-6}, {"cdt",-5}, {"mst",-7}, {"mdt",-6}, {"pst",-8}, {"pdt",-7}};
+ int i,j;
+
+ for (i = 0; i<4; ++i)
+ {
+ zone[i] = tolower(*(str+i));
+ if (zone[i]<'a' || zone[i]>'z') break;
+ }
+ zone[i] = '\0';
+ for (j = 0; j<10 && strcmp(zone,zone_name[j].name); ++j);
+ /* Besides zones named in the grammar, RFC 2822 says other alphabetic */
+ /* time zones should be treated as unknown offsets. */
+ if (j<10)
+ {
+ *z = zone_name[j].off*3600;
+ str+=i;
+ }
+ else if (zone[0]<'a' || zone[1]>'z') return 0;
+ else
+ {
+ while ((*str>='a' && *str<='z') || (*str>='A' && *str<='Z')) ++str;
+ *z = 0;
+ }
+ }
+return str;
+}
+
+
+/*************************************************
+* Parse a RFC 2822 date-time *
+*************************************************/
+
+/* Parse a RFC 2822 date-time and return it in seconds since the epoch.
+
+Arguments:
+ str pointer to the start of the date-time
+ t pointer to the parsed time
+
+Returns: points after the processed date-time or NULL on error
+*/
+
+const uschar *
+parse_date_time(const uschar *str, time_t *t)
+{
+/*
+date-time = [ day-of-week "," ] date FWS time [CFWS]
+*/
+
+struct tm tm;
+int zone;
+extern char **environ;
+char **old_environ;
+static char gmt0[]="TZ=GMT0";
+static char *gmt_env[]={ gmt0, (char*)0 };
+const uschar * try;
+
+if ((try = parse_day_of_week(str)))
+ {
+ str = try;
+ if (*str!=',') return 0;
+ ++str;
+ }
+if ((str = parse_date(str,&tm.tm_mday,&tm.tm_mon,&tm.tm_year)) == NULL) return NULL;
+if (*str!=' ' && *str!='\t') return NULL;
+while (*str == ' ' || *str == '\t') ++str;
+if ((str = parse_time(str,&tm.tm_hour,&tm.tm_min,&tm.tm_sec,&zone)) == NULL) return NULL;
+tm.tm_isdst = 0;
+old_environ = environ;
+environ = gmt_env;
+*t = mktime(&tm);
+environ = old_environ;
+if (*t == -1) return NULL;
+*t-=zone;
+return skip_comment(str);
+}
+
+