add libhttpd

src/libhttpd/date.c

@@ -0,0 +1,212 @@
+#include <u.h>
+#include <libc.h>
+#include <httpd.h>
+
+/*
+ * print dates in the format
+ * Wkd, DD Mon YYYY HH:MM:SS GMT
+ * parse dates of formats
+ * Wkd, DD Mon YYYY HH:MM:SS GMT
+ * Weekday, DD-Mon-YY HH:MM:SS GMT
+ * Wkd Mon ( D|DD) HH:MM:SS YYYY
+ * plus anything similar
+ */
+static char *
+weekdayname[7] =
+{
+	"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
+};
+static char *
+wdayname[7] =
+{
+	"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+};
+
+static char *
+monname[12] =
+{
+	"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+};
+
+static	int	dateindex(char*, char**, int);
+
+static int
+dtolower(int c)
+{
+	if(c >= 'A' && c <= 'Z')
+		return c - 'A' + 'a';
+	return c;
+}
+
+static int
+disalpha(int c)
+{
+	return c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z';
+}
+
+static int
+disdig(int c)
+{
+	return c >= '0' && c <= '9';
+}
+
+int
+hdatefmt(Fmt *f)
+{
+	Tm *tm;
+	ulong t;
+
+	t = va_arg(f->args, ulong);
+	tm = gmtime(t);
+	return fmtprint(f, "%s, %.2d %s %.4d %.2d:%.2d:%.2d GMT",
+		wdayname[tm->wday], tm->mday, monname[tm->mon], tm->year+1900,
+		tm->hour, tm->min, tm->sec);
+}
+
+static char*
+dateword(char *date, char *buf)
+{
+	char *p;
+	int c;
+
+	p = buf;
+	while(!disalpha(c = *date) && !disdig(c) && c)
+		date++;
+	while(disalpha(c = *date)){
+		if(p - buf < 30)
+			*p++ = dtolower(c);
+		date++;
+	}
+	*p = 0;
+	return date;
+}
+
+static int
+datenum(char **d)
+{
+	char *date;
+	int c, n;
+
+	date = *d;
+	while(!disdig(c = *date) && c)
+		date++;
+	if(c == 0){
+		*d = date;
+		return -1;
+	}
+	n = 0;
+	while(disdig(c = *date)){
+		n = n * 10 + c - '0';
+		date++;
+	}
+	*d = date;
+	return n;
+}
+
+/*
+ * parse a date and return the seconds since the epoch
+ * return 0 for a failure
+ */
+ulong
+hdate2sec(char *date)
+{
+	Tm tm;
+	char buf[32];
+
+	/*
+	 * Weekday|Wday
+	 */
+	date = dateword(date, buf);
+	tm.wday = dateindex(buf, wdayname, 7);
+	if(tm.wday < 0)
+		tm.wday = dateindex(buf, weekdayname, 7);
+	if(tm.wday < 0)
+		return 0;
+
+	/*
+	 * check for the two major formats
+	 */
+	date = dateword(date, buf);
+	tm.mon = dateindex(buf, monname, 12);
+	if(tm.mon >= 0){
+		/*
+		 * MM
+		 */
+		tm.mday = datenum(&date);
+		if(tm.mday < 1 || tm.mday > 31)
+			return 0;
+
+		/*
+		 * HH:MM:SS
+		 */
+		tm.hour = datenum(&date);
+		if(tm.hour < 0 || tm.hour >= 24)
+			return 0;
+		tm.min = datenum(&date);
+		if(tm.min < 0 || tm.min >= 60)
+			return 0;
+		tm.sec = datenum(&date);
+		if(tm.sec < 0 || tm.sec >= 60)
+			return 0;
+
+		/*
+		 * YYYY
+		 */
+		tm.year = datenum(&date);
+		if(tm.year < 70 || tm.year > 99 && tm.year < 1970)
+			return 0;
+		if(tm.year >= 1970)
+			tm.year -= 1900;
+	}else{
+		/*
+		 * MM-Mon-(YY|YYYY)
+		 */
+		tm.mday = datenum(&date);
+		if(tm.mday < 1 || tm.mday > 31)
+			return 0;
+		date = dateword(date, buf);
+		tm.mon = dateindex(buf, monname, 12);
+		if(tm.mon < 0 || tm.mon >= 12)
+			return 0;
+		tm.year = datenum(&date);
+		if(tm.year < 70 || tm.year > 99 && tm.year < 1970)
+			return 0;
+		if(tm.year >= 1970)
+			tm.year -= 1900;
+
+		/*
+		 * HH:MM:SS
+		 */
+		tm.hour = datenum(&date);
+		if(tm.hour < 0 || tm.hour >= 24)
+			return 0;
+		tm.min = datenum(&date);
+		if(tm.min < 0 || tm.min >= 60)
+			return 0;
+		tm.sec = datenum(&date);
+		if(tm.sec < 0 || tm.sec >= 60)
+			return 0;
+
+		/*
+		 * timezone
+		 */
+		dateword(date, buf);
+		if(strncmp(buf, "gmt", 3) != 0)
+			return 0;
+	}
+
+	strcpy(tm.zone, "GMT");
+	tm.tzoff = 0;
+	return tm2sec(&tm);
+}
+
+static int
+dateindex(char *d, char **tab, int n)
+{
+	int i;
+
+	for(i = 0; i < n; i++)
+		if(cistrcmp(d, tab[i]) == 0)
+			return i;
+	return -1;
+}