ubgpsuite/tools/bgpgrep/bgpgrep_timestamp.c

263 lines
5.8 KiB
C

// SPDX-License-Identifier: GPL-3.0-or-later
/**
* \file bgpgrep_timestamp.c
*
* Timestamp expressions parsing and compilation.
*
* \copyright The DoubleFourteen Code Forge (C) All Rights Reserved
* \author Lorenzo Cogotti
*/
#include "bgpgrep_local.h"
#include "numlib.h"
#include "strlib.h"
#include <assert.h>
#include <math.h>
#include <string.h>
#include <time.h>
#define SECSPERMIN (60)
#define SECSPERHOUR (60 * SECSPERMIN)
#define FATAL(msg) Bgpgrep_Fatal("%s: " msg, BgpgrepC_CurTerm())
#define FATALF(fmt, ...) Bgpgrep_Fatal("%s: " fmt, BgpgrepC_CurTerm(), __VA_ARGS__)
static time_t UtcTime(struct tm *t)
{
#ifdef _WIN32
return _mkgmtime(t);
#else
return timegm(t);
#endif
}
static Uint32 ParseFrac(const char *s, const char *p, char **ep)
{
char *endp;
NumConvRet res;
unsigned long long n = Atoull(p, &endp, 10, &res);
if (res != NCVENOERR)
FATALF("%s: Expecting fractional portion of a second after '.'", s);
int ndigs = endp - p;
long double frac = pow(10, ndigs);
if (ep)
*ep = endp;
return (Uint32) truncl(n / frac * 1000000.0L);
}
static Boolean ParseRfc3339(const char *s, Timestampop *dest)
{
NumConvRet res;
char *p, *ep;
int yyyy, mm, dd, h, min, secs, microsecs;
int timeOff;
Boolean expectTimeOfDay;
struct tm t;
memset(&t, 0, sizeof(t));
p = (char *) s;
yyyy = Atou(p, &ep, 10, &res);
if (res != NCVENOERR || (*ep != '-' && *ep != ':'))
return FALSE; // Invalid RFC-3339 format
h = min = secs = microsecs = 0;
timeOff = 0;
expectTimeOfDay = FALSE;
if (*ep == '-') {
// YYYY-MM-DD
if (ep - p != 4)
FATALF("%s: Expecting 4-digit year number", s);
p = ++ep;
mm = Atou(p, &ep, 10, &res);
if (res != NCVENOERR || ep - p != 2)
FATALF("%s: Expecting 2-digit month field", s);
if (*ep != '-')
FATALF("%s: Missing day of month field", s);
p = ++ep;
dd = Atou(p, &ep, 10, &res);
if (res != NCVENOERR || ep - p != 2)
FATALF("%s: Expecting 2-digit day of month field", s);
// Rescale values for struct tm
yyyy -= 1900;
mm -= 1;
if (*ep == 'T' || *ep == 't') {
++ep;
expectTimeOfDay = TRUE;
}
p = ep;
} else {
// What we've parsed is not YYYY, but actually HH,
// Reset parser and expect to get time of day
p = (char *) s;
expectTimeOfDay = TRUE;
// Setup YYYY-MM-DD from current date, in UTC
const time_t now = time(NULL);
const struct tm *cur = gmtime(&now);
if (!cur) // PARANOID
FATAL("gmtime() failed: Could not retrieve current date");
yyyy = cur->tm_year;
mm = cur->tm_mon;
dd = cur->tm_mday;
}
if (expectTimeOfDay) {
// HOUR:MIN[:SECS[.FRAC]]
h = Atou(p, &ep, 10, &res);
if (res != NCVENOERR || *ep != ':' || ep - p != 2)
FATALF("%s: Expected 2-digits for hour field", s);
p = ++ep;
min = Atou(p, &ep, 10, &res);
if (res != NCVENOERR || ep - p != 2)
FATALF("%s: Expected 2-digits for minutes field", s);
if (*ep == ':') {
// SECS[.FRAC]
p = ++ep;
secs = Atou(p, &ep, 10, &res);
if (res != NCVENOERR || ep - p != 2)
FATALF("%s: Expected 2-digits for seconds field", s);
if (*ep == '.') {
// Fraction of a second
p = ++ep;
microsecs = ParseFrac(s, p, &ep);
}
}
}
if (*ep == '+' || *ep == '-') {
// Time offset +/- HH:MM
int hoursOff, minOff;
int sign = (*ep == '+') ? 1 : -1;
p = ++ep;
hoursOff = Atou(p, &ep, 10, &res);
if (res != NCVENOERR || *ep != ':' || ep - p != 2 || hoursOff < 0 || hoursOff > 23)
FATALF("%s: Expected valid 2-digit hours field for timezone offset", s);
p = ++ep;
minOff = Atou(p, &ep, 10, &res);
if (res != NCVENOERR || ep - p != 2 || minOff < 0 || minOff > 59)
FATALF("%s: Expected valid 2-digit minute field for timezone offset", s);
timeOff = (hoursOff*SECSPERHOUR + minOff*SECSPERMIN);
timeOff *= sign;
} else if (*ep == 'Z' || *ep == 'z')
++ep; // explicit UTC marker
if (*ep != '\0')
FATALF("%s: Bad timestamp format", s);
if (h == 24 && min == 0 && secs == 0 && microsecs == 0) {
// 24:00:00 -> 00:00:00
// we adjust time offset to add one day to epoch
h = 0;
timeOff -= 24*SECSPERHOUR;
}
// Convert to UTC time_t
t.tm_year = yyyy;
t.tm_mon = mm;
t.tm_mday = dd;
t.tm_hour = h;
t.tm_min = min;
t.tm_sec = secs;
time_t epoch = UtcTime(&t);
// Do not accept renormalized dates
if (t.tm_year != yyyy || t.tm_mon != mm || t.tm_mday != dd ||
t.tm_hour != h || t.tm_min != min || t.tm_sec != secs)
FATALF("%s: Invalid timestamp", s);
// Adjust for time offset
dest->secs = epoch - timeOff; // assume POSIX time_t semantics
dest->microsecs = microsecs;
return TRUE;
}
static Boolean ParseEpoch(const char *s, Timestampop *dest)
{
char *p;
NumConvRet res;
dest->secs = Atoll(s, &p, 10, &res);
if (res != NCVENOERR)
return FALSE;
if (*p == '.') {
++p;
dest->microsecs = ParseFrac(s, p, &p);
} else
dest->microsecs = 0;
return *p == '\0';
}
Sint32 BgpgrepC_ParseTimestampExpression(void)
{
const char *tok = BgpgrepC_ExpectAnyToken();
Timestampop *stamp = (Timestampop *) Bgp_VmPermAlloc(&S.vm, sizeof(*stamp));
if (!stamp)
Bgpgrep_Fatal("Memory allocation failed, too many timestamp operations");
// Optional operator
stamp->opc = TIMESTAMP_EQ;
if (strncmp(tok, "<=", 2) == 0) {
stamp->opc = TIMESTAMP_LE;
tok += 2;
} else if (*tok == '<') {
stamp->opc = TIMESTAMP_LT;
tok++;
} else if (*tok == '!') {
stamp->opc = TIMESTAMP_NE;
tok++;
} else if (*tok == '=') {
stamp->opc = TIMESTAMP_EQ;
tok++;
} else if (strncmp(tok, ">=", 2) == 0) {
stamp->opc = TIMESTAMP_GE;
tok += 2;
} else if (*tok == '>') {
stamp->opc = TIMESTAMP_GT;
tok++;
}
// Timestamp value
if (!ParseRfc3339(tok, stamp) && !ParseEpoch(tok, stamp))
FATALF("Unrecognized timestamp format '%s'", tok);
Sint32 kidx = BGP_VMSETKA(&S.vm, Bgp_VmNewk(&S.vm), stamp);
if (kidx < 0)
Bgpgrep_Fatal("Expression has too many timestamp operations");
return kidx;
}