diff options
Diffstat (limited to 'rfc822/rfc822_parsedt.c')
| -rw-r--r-- | rfc822/rfc822_parsedt.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/rfc822/rfc822_parsedt.c b/rfc822/rfc822_parsedt.c new file mode 100644 index 0000000..036be34 --- /dev/null +++ b/rfc822/rfc822_parsedt.c @@ -0,0 +1,256 @@ +/* +** Copyright 1998 - 2011 Double Precision, Inc. +** See COPYING for distribution information. +*/ + +/* +*/ +#include "config.h" +#include <stdio.h> +#include <string.h> +#include <time.h> + +#define my_isalpha(c) ( ( (c) >= 'a' && (c) <= 'z' ) || \ + ( (c) >= 'A' && (c) <= 'Z' ) ) + +#define my_isdigit(c) ( (c) >= '0' && (c) <= '9' ) + +#define my_isalnum(c) ( my_isalpha(c) || my_isdigit(c) ) + +#define my_isspace(c) ( (c) == ' ' || (c) == '\t' || (c) == '\r' || (c) == '\n') + +/* +** time_t rfc822_parsedate(const char *p) +** +** p - contents of the Date: header, attempt to parse it into a time_t. +** +** returns - time_t, or 0 if the date cannot be parsed +*/ + +static unsigned parsedig(const char **p) +{ + unsigned i=0; + + while (my_isdigit(**p)) + { + i=i*10 + **p - '0'; + ++*p; + } + return (i); +} + +static const char * const weekdays[7]={ + "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" + } ; + +static const char * const mnames[13]={ + "Jan", "Feb", "Mar", "Apr", + "May", "Jun", "Jul", "Aug", + "Sep", "Oct", "Nov", "Dec", NULL}; + +#define leap(y) ( \ + ((y) % 400) == 0 || \ + (((y) % 4) == 0 && (y) % 100) ) + +static unsigned mlength[]={31,28,31,30,31,30,31,31,30,31,30,31}; +#define mdays(m,y) ( (m) != 2 ? mlength[(m)-1] : leap(y) ? 29:28) + +static const char * const zonenames[] = { + "UT","GMT", + "EST","EDT", + "CST","CDT", + "MST","MDT", + "PST","PDT", + "Z", + "A", "B", "C", "D", "E", "F", "G", "H", "I", "K", "L", "M", + "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", + NULL}; + +#define ZH(n) ( (n) * 60 * 60 ) + +static int zoneoffset[] = { + 0, 0, + ZH(-5), ZH(-4), + ZH(-6), ZH(-5), + ZH(-7), ZH(-6), + ZH(-8), ZH(-7), + 0, + + ZH(-1), ZH(-2), ZH(-3), ZH(-4), ZH(-5), ZH(-6), ZH(-7), ZH(-8), ZH(-9), ZH(-10), ZH(-11), ZH(-12), + ZH(1), ZH(2), ZH(3), ZH(4), ZH(5), ZH(6), ZH(7), ZH(8), ZH(9), ZH(10), ZH(11), ZH(12) }; + +#define lc(x) ((x) >= 'A' && (x) <= 'Z' ? (x) + ('a'-'A'):(x)) + +static unsigned parsekey(const char **mon, const char * const *ary) +{ +unsigned m, j; + + for (m=0; ary[m]; m++) + { + for (j=0; ary[m][j]; j++) + if (lc(ary[m][j]) != lc((*mon)[j])) + break; + if (!ary[m][j]) + { + *mon += j; + return (m+1); + } + } + return (0); +} + +static int parsetime(const char **t) +{ + unsigned h,m,s=0; + + if (!my_isdigit(**t)) return (-1); + + h=parsedig(t); + if (h > 23) return (-1); + if (**t != ':') return (-1); + ++*t; + if (!my_isdigit(**t)) return (-1); + m=parsedig(t); + if (**t == ':') + { + ++*t; + + if (!my_isdigit(**t)) return (-1); + s=parsedig(t); + } + if (m > 59 || s > 59) return (-1); + return (h * 60 * 60 + m * 60 + s); +} + +time_t rfc822_parsedt(const char *rfcdt) +{ +unsigned day=0, mon=0, year; +int secs; +int offset; +time_t t; +unsigned y; + + /* Ignore day of the week. Tolerate "Tue, 25 Feb 1997 ... " + ** without the comma. Tolerate "Feb 25 1997 ...". + */ + + while (!day || !mon) + { + if (!*rfcdt) return (0); + if (my_isalpha(*rfcdt)) + { + if (mon) return (0); + mon=parsekey(&rfcdt, mnames); + if (!mon) + while (*rfcdt && my_isalpha(*rfcdt)) + ++rfcdt; + continue; + } + + if (my_isdigit(*rfcdt)) + { + if (day) return (0); + day=parsedig(&rfcdt); + if (!day) return (0); + continue; + } + ++rfcdt; + } + + while (*rfcdt && my_isspace(*rfcdt)) + ++rfcdt; + if (!my_isdigit(*rfcdt)) return (0); + year=parsedig(&rfcdt); + if (year < 70) year += 2000; + if (year < 100) year += 1900; + + while (*rfcdt && my_isspace(*rfcdt)) + ++rfcdt; + + if (day == 0 || mon == 0 || mon > 12 || day > mdays(mon,year)) + return (0); + + secs=parsetime(&rfcdt); + if (secs < 0) return (0); + + offset=0; + + /* RFC822 sez no parenthesis, but I've seen (EST) */ + + while ( *rfcdt ) + { + if (my_isalnum(*rfcdt) || *rfcdt == '+' || *rfcdt == '-') + break; + ++rfcdt; + } + + if (my_isalpha((int)(unsigned char)*rfcdt)) + { + int n=parsekey(&rfcdt, zonenames); + + if (n > 0) offset= zoneoffset[n-1]; + } + else + { + int sign=1; + unsigned n; + + switch (*rfcdt) { + case '-': + sign= -1; + case '+': + ++rfcdt; + } + + if (my_isdigit(*rfcdt)) + { + n=parsedig(&rfcdt); + if (n > 2359 || (n % 100) > 59) n=0; + offset = sign * ( (n % 100) * 60 + n / 100 * 60 * 60); + } + } + + if (year < 1970) return (0); + if (year > 9999) return (0); + + t=0; + for (y=1970; y<year; y++) + { + if ( leap(y) ) + { + if (year-y >= 4) + { + y += 3; + t += ( 365*3+366 ) * 24 * 60 * 60; + continue; + } + t += 24 * 60 * 60; + } + t += 365 * 24 * 60 * 60; + } + + for (y=1; y < mon; y++) + t += mdays(y, year) * 24 * 60 * 60; + + return ( t + (day-1) * 24 * 60 * 60 + secs - offset ); +} + +const char *rfc822_mkdt(time_t t) +{ +static char buf[80]; +struct tm *tmptr=gmtime(&t); + + buf[0]=0; + if (tmptr) + { + sprintf(buf, "%s, %02d %s %04d %02d:%02d:%02d GMT", + weekdays[tmptr->tm_wday], + tmptr->tm_mday, + mnames[tmptr->tm_mon], + tmptr->tm_year + 1900, + tmptr->tm_hour, + tmptr->tm_min, + tmptr->tm_sec); + } + return (buf); +} |