+/*************************************************
+* Parse a fixed digit number *
+*************************************************/
+
+/* Parse a string containing an ASCII encoded fixed digits number
+
+Arguments:
+ str pointer to the start of the ASCII encoded number
+ n pointer to the resulting value
+ digits number of required digits
+
+Returns: points after the processed date or NULL on error
+*/
+
+static uschar *
+parse_number(uschar *str, int *n, int digits)
+{
+ *n=0;
+ while (digits--)
+ {
+ if (*str<'0' || *str>'9') return NULL;
+ *n=10*(*n)+(*str++-'0');
+ }
+ return str;
+}
+
+
+/*************************************************
+* Parse a RFC 2822 day of week *
+*************************************************/
+
+/* Parse the day of the week from a RFC 2822 date, but do not
+ decode it, because it is only for humans.
+
+Arguments:
+ str pointer to the start of the day of the week
+
+Returns: points after the parsed day or NULL on error
+*/
+
+static uschar *
+parse_day_of_week(uschar *str)
+{
+/*
+day-of-week = ([FWS] day-name) / obs-day-of-week
+
+day-name = "Mon" / "Tue" / "Wed" / "Thu" /
+ "Fri" / "Sat" / "Sun"
+
+obs-day-of-week = [CFWS] day-name [CFWS]
+*/
+
+static const uschar *day_name[7]={ US"mon", US"tue", US"wed", US"thu", US"fri", US"sat", US"sun" };
+int i;
+uschar day[4];
+
+str=skip_comment(str);
+for (i=0; i<3; ++i)
+ {
+ if ((day[i]=tolower(*str))=='\0') return NULL;
+ ++str;
+ }
+day[3]='\0';
+for (i=0; i<7; ++i) if (Ustrcmp(day,day_name[i])==0) break;
+if (i==7) return NULL;
+str=skip_comment(str);
+return str;
+}
+
+
+/*************************************************
+* Parse a RFC 2822 date *
+*************************************************/
+
+/* Parse the date part of a RFC 2822 date-time, extracting the
+ day, month and year.
+
+Arguments:
+ str pointer to the start of the date
+ d pointer to the resulting day
+ m pointer to the resulting month
+ y pointer to the resulting year
+
+Returns: points after the processed date or NULL on error
+*/
+
+static uschar *
+parse_date(uschar *str, int *d, int *m, int *y)
+{
+/*
+date = day month year
+
+year = 4*DIGIT / obs-year
+
+obs-year = [CFWS] 2*DIGIT [CFWS]
+
+month = (FWS month-name FWS) / obs-month
+
+month-name = "Jan" / "Feb" / "Mar" / "Apr" /
+ "May" / "Jun" / "Jul" / "Aug" /
+ "Sep" / "Oct" / "Nov" / "Dec"
+
+obs-month = CFWS month-name CFWS
+
+day = ([FWS] 1*2DIGIT) / obs-day
+
+obs-day = [CFWS] 1*2DIGIT [CFWS]
+*/
+
+uschar *c,*n;
+static const uschar *month_name[]={ US"jan", US"feb", US"mar", US"apr", US"may", US"jun", US"jul", US"aug", US"sep", US"oct", US"nov", US"dec" };
+int i;
+uschar month[4];
+
+str=skip_comment(str);
+if ((str=parse_number(str,d,1))==NULL) return NULL;
+if (*str>='0' && *str<='9') *d=10*(*d)+(*str++-'0');
+c=skip_comment(str);
+if (c==str) return NULL;
+else str=c;
+for (i=0; i<3; ++i) if ((month[i]=tolower(*(str+i)))=='\0') return NULL;
+month[3]='\0';
+for (i=0; i<12; ++i) if (Ustrcmp(month,month_name[i])==0) break;
+if (i==12) return NULL;
+str+=3;
+*m=i;
+c=skip_comment(str);
+if (c==str) return NULL;
+else str=c;
+if ((n=parse_number(str,y,4)))
+ {
+ str=n;
+ if (*y<1900) return NULL;
+ *y=*y-1900;
+ }
+else if ((n=parse_number(str,y,2)))
+ {
+ str=skip_comment(n);
+ while (*(str-1)==' ' || *(str-1)=='\t') --str; /* match last FWS later */
+ if (*y<50) *y+=100;
+ }
+else return NULL;
+return str;
+}
+
+
+/*************************************************
+* 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 uschar *
+parse_time(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
+*/
+
+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
+*/
+
+uschar *
+parse_date_time(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 };
+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;
+str=skip_comment(str);
+return str;
+}
+
+
git://git.exim.org / exim.git / blobdiff