diff options
Diffstat (limited to 'extensions/libxt_time.c')
| -rw-r--r-- | extensions/libxt_time.c | 485 |
1 files changed, 485 insertions, 0 deletions
diff --git a/extensions/libxt_time.c b/extensions/libxt_time.c new file mode 100644 index 0000000..098fc9c --- /dev/null +++ b/extensions/libxt_time.c @@ -0,0 +1,485 @@ +/* + * libxt_time - iptables part for xt_time + * Copyright © CC Computer Consultants GmbH, 2007 + * Contact: <jengelh@computergmbh.de> + * + * libxt_time.c is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 or 3 of the License. + * + * Based on libipt_time.c. + */ +#include <sys/types.h> +#include <getopt.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <stddef.h> +#include <time.h> +#include <limits.h> + +#include <linux/netfilter/xt_time.h> +#include <xtables.h> + +enum { /* getopt "seen" bits */ + F_DATE_START = 1 << 0, + F_DATE_STOP = 1 << 1, + F_TIME_START = 1 << 2, + F_TIME_STOP = 1 << 3, + F_MONTHDAYS = 1 << 4, + F_WEEKDAYS = 1 << 5, + F_TIMEZONE = 1 << 6, +}; + +static const char *const week_days[] = { + NULL, "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun", +}; + +static const struct option time_opts[] = { + {"datestart", true, NULL, 'D'}, + {"datestop", true, NULL, 'E'}, + {"timestart", true, NULL, 'X'}, + {"timestop", true, NULL, 'Y'}, + {"weekdays", true, NULL, 'w'}, + {"monthdays", true, NULL, 'm'}, + {"localtz", false, NULL, 'l'}, + {"utc", false, NULL, 'u'}, + { .name = NULL } +}; + +static void time_help(void) +{ + printf( +"time match options:\n" +" --datestart time Start and stop time, to be given in ISO 8601\n" +" --datestop time (YYYY[-MM[-DD[Thh[:mm[:ss]]]]])\n" +" --timestart time Start and stop daytime (hh:mm[:ss])\n" +" --timestop time (between 00:00:00 and 23:59:59)\n" +"[!] --monthdays value List of days on which to match, separated by comma\n" +" (Possible days: 1 to 31; defaults to all)\n" +"[!] --weekdays value List of weekdays on which to match, sep. by comma\n" +" (Possible days: Mon,Tue,Wed,Thu,Fri,Sat,Sun or 1 to 7\n" +" Defaults to all weekdays.)\n" +" --localtz/--utc Time is interpreted as UTC/local time\n"); +} + +static void time_init(struct xt_entry_match *m) +{ + struct xt_time_info *info = (void *)m->data; + + /* By default, we match on every day, every daytime */ + info->monthdays_match = XT_TIME_ALL_MONTHDAYS; + info->weekdays_match = XT_TIME_ALL_WEEKDAYS; + info->daytime_start = XT_TIME_MIN_DAYTIME; + info->daytime_stop = XT_TIME_MAX_DAYTIME; + + /* ...and have no date-begin or date-end boundary */ + info->date_start = 0; + info->date_stop = INT_MAX; + + /* local time is default */ + info->flags |= XT_TIME_LOCAL_TZ; +} + +static time_t time_parse_date(const char *s, bool end) +{ + unsigned int month = 1, day = 1, hour = 0, minute = 0, second = 0; + unsigned int year = end ? 2038 : 1970; + const char *os = s; + struct tm tm; + time_t ret; + char *e; + + year = strtoul(s, &e, 10); + if ((*e != '-' && *e != '\0') || year < 1970 || year > 2038) + goto out; + if (*e == '\0') + goto eval; + + s = e + 1; + month = strtoul(s, &e, 10); + if ((*e != '-' && *e != '\0') || month > 12) + goto out; + if (*e == '\0') + goto eval; + + s = e + 1; + day = strtoul(s, &e, 10); + if ((*e != 'T' && *e != '\0') || day > 31) + goto out; + if (*e == '\0') + goto eval; + + s = e + 1; + hour = strtoul(s, &e, 10); + if ((*e != ':' && *e != '\0') || hour > 23) + goto out; + if (*e == '\0') + goto eval; + + s = e + 1; + minute = strtoul(s, &e, 10); + if ((*e != ':' && *e != '\0') || minute > 59) + goto out; + if (*e == '\0') + goto eval; + + s = e + 1; + second = strtoul(s, &e, 10); + if (*e != '\0' || second > 59) + goto out; + + eval: + tm.tm_year = year - 1900; + tm.tm_mon = month - 1; + tm.tm_mday = day; + tm.tm_hour = hour; + tm.tm_min = minute; + tm.tm_sec = second; + ret = mktime(&tm); + if (ret >= 0) + return ret; + perror("mktime"); + xtables_error(OTHER_PROBLEM, "mktime returned an error"); + + out: + xtables_error(PARAMETER_PROBLEM, "Invalid date \"%s\" specified. Should " + "be YYYY[-MM[-DD[Thh[:mm[:ss]]]]]", os); + return -1; +} + +static unsigned int time_parse_minutes(const char *s) +{ + unsigned int hour, minute, second = 0; + char *e; + + hour = strtoul(s, &e, 10); + if (*e != ':' || hour > 23) + goto out; + + s = e + 1; + minute = strtoul(s, &e, 10); + if ((*e != ':' && *e != '\0') || minute > 59) + goto out; + if (*e == '\0') + goto eval; + + s = e + 1; + second = strtoul(s, &e, 10); + if (*e != '\0' || second > 59) + goto out; + + eval: + return 60 * 60 * hour + 60 * minute + second; + + out: + xtables_error(PARAMETER_PROBLEM, "invalid time \"%s\" specified, " + "should be hh:mm[:ss] format and within the boundaries", s); + return -1; +} + +static const char *my_strseg(char *buf, unsigned int buflen, + const char **arg, char delim) +{ + const char *sep; + + if (*arg == NULL || **arg == '\0') + return NULL; + sep = strchr(*arg, delim); + if (sep == NULL) { + snprintf(buf, buflen, "%s", *arg); + *arg = NULL; + return buf; + } + snprintf(buf, buflen, "%.*s", (unsigned int)(sep - *arg), *arg); + *arg = sep + 1; + return buf; +} + +static uint32_t time_parse_monthdays(const char *arg) +{ + char day[3], *err = NULL; + uint32_t ret = 0; + unsigned int i; + + while (my_strseg(day, sizeof(day), &arg, ',') != NULL) { + i = strtoul(day, &err, 0); + if ((*err != ',' && *err != '\0') || i > 31) + xtables_error(PARAMETER_PROBLEM, + "%s is not a valid day for --monthdays", day); + ret |= 1 << i; + } + + return ret; +} + +static unsigned int time_parse_weekdays(const char *arg) +{ + char day[4], *err = NULL; + unsigned int i, ret = 0; + bool valid; + + while (my_strseg(day, sizeof(day), &arg, ',') != NULL) { + i = strtoul(day, &err, 0); + if (*err == '\0') { + if (i == 0) + xtables_error(PARAMETER_PROBLEM, + "No, the week does NOT begin with Sunday."); + ret |= 1 << i; + continue; + } + + valid = false; + for (i = 1; i < ARRAY_SIZE(week_days); ++i) + if (strncmp(day, week_days[i], 2) == 0) { + ret |= 1 << i; + valid = true; + } + + if (!valid) + xtables_error(PARAMETER_PROBLEM, + "%s is not a valid day specifier", day); + } + + return ret; +} + +static int time_parse(int c, char **argv, int invert, unsigned int *flags, + const void *entry, struct xt_entry_match **match) +{ + struct xt_time_info *info = (void *)(*match)->data; + + switch (c) { + case 'D': /* --datestart */ + if (*flags & F_DATE_START) + xtables_error(PARAMETER_PROBLEM, + "Cannot specify --datestart twice"); + if (invert) + xtables_error(PARAMETER_PROBLEM, + "Unexpected \"!\" with --datestart"); + info->date_start = time_parse_date(optarg, false); + *flags |= F_DATE_START; + return 1; + case 'E': /* --datestop */ + if (*flags & F_DATE_STOP) + xtables_error(PARAMETER_PROBLEM, + "Cannot specify --datestop more than once"); + if (invert) + xtables_error(PARAMETER_PROBLEM, + "unexpected \"!\" with --datestop"); + info->date_stop = time_parse_date(optarg, true); + *flags |= F_DATE_STOP; + return 1; + case 'X': /* --timestart */ + if (*flags & F_TIME_START) + xtables_error(PARAMETER_PROBLEM, + "Cannot specify --timestart more than once"); + if (invert) + xtables_error(PARAMETER_PROBLEM, + "Unexpected \"!\" with --timestart"); + info->daytime_start = time_parse_minutes(optarg); + *flags |= F_TIME_START; + return 1; + case 'Y': /* --timestop */ + if (*flags & F_TIME_STOP) + xtables_error(PARAMETER_PROBLEM, + "Cannot specify --timestop more than once"); + if (invert) + xtables_error(PARAMETER_PROBLEM, + "Unexpected \"!\" with --timestop"); + info->daytime_stop = time_parse_minutes(optarg); + *flags |= F_TIME_STOP; + return 1; + case 'l': /* --localtz */ + if (*flags & F_TIMEZONE) + xtables_error(PARAMETER_PROBLEM, + "Can only specify exactly one of --localtz or --utc"); + info->flags |= XT_TIME_LOCAL_TZ; + *flags |= F_TIMEZONE; + return 1; + case 'm': /* --monthdays */ + if (*flags & F_MONTHDAYS) + xtables_error(PARAMETER_PROBLEM, + "Cannot specify --monthdays more than once"); + info->monthdays_match = time_parse_monthdays(optarg); + if (invert) + info->monthdays_match ^= XT_TIME_ALL_MONTHDAYS; + *flags |= F_MONTHDAYS; + return 1; + case 'w': /* --weekdays */ + if (*flags & F_WEEKDAYS) + xtables_error(PARAMETER_PROBLEM, + "Cannot specify --weekdays more than once"); + info->weekdays_match = time_parse_weekdays(optarg); + if (invert) + info->weekdays_match ^= XT_TIME_ALL_WEEKDAYS; + *flags |= F_WEEKDAYS; + return 1; + case 'u': /* --utc */ + if (*flags & F_TIMEZONE) + xtables_error(PARAMETER_PROBLEM, + "Can only specify exactly one of --localtz or --utc"); + info->flags &= ~XT_TIME_LOCAL_TZ; + *flags |= F_TIMEZONE; + return 1; + } + return 0; +} + +static void time_print_date(time_t date, const char *command) +{ + struct tm *t; + + /* If it is the default value, do not print it. */ + if (date == 0 || date == LONG_MAX) + return; + + t = localtime(&date); + if (command != NULL) + /* + * Need a contiguous string (no whitespaces), hence using + * the ISO 8601 "T" variant. + */ + printf("%s %04u-%02u-%02uT%02u:%02u:%02u ", + command, t->tm_year + 1900, t->tm_mon + 1, + t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec); + else + printf("%04u-%02u-%02u %02u:%02u:%02u ", + t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, + t->tm_hour, t->tm_min, t->tm_sec); +} + +static void time_print_monthdays(uint32_t mask, bool human_readable) +{ + unsigned int i, nbdays = 0; + + for (i = 1; i <= 31; ++i) + if (mask & (1 << i)) { + if (nbdays++ > 0) + printf(","); + printf("%u", i); + if (human_readable) + switch (i % 10) { + case 1: + printf("st"); + break; + case 2: + printf("nd"); + break; + case 3: + printf("rd"); + break; + default: + printf("th"); + break; + } + } + printf(" "); +} + +static void time_print_weekdays(unsigned int mask) +{ + unsigned int i, nbdays = 0; + + for (i = 1; i <= 7; ++i) + if (mask & (1 << i)) { + if (nbdays > 0) + printf(",%s", week_days[i]); + else + printf("%s", week_days[i]); + ++nbdays; + } + printf(" "); +} + +static inline void divide_time(unsigned int fulltime, unsigned int *hours, + unsigned int *minutes, unsigned int *seconds) +{ + *seconds = fulltime % 60; + fulltime /= 60; + *minutes = fulltime % 60; + *hours = fulltime / 60; +} + +static void time_print(const void *ip, const struct xt_entry_match *match, + int numeric) +{ + const struct xt_time_info *info = (const void *)match->data; + unsigned int h, m, s; + + printf("TIME "); + + if (info->daytime_start != XT_TIME_MIN_DAYTIME || + info->daytime_stop != XT_TIME_MAX_DAYTIME) { + divide_time(info->daytime_start, &h, &m, &s); + printf("from %02u:%02u:%02u ", h, m, s); + divide_time(info->daytime_stop, &h, &m, &s); + printf("to %02u:%02u:%02u ", h, m, s); + } + if (info->weekdays_match != XT_TIME_ALL_WEEKDAYS) { + printf("on "); + time_print_weekdays(info->weekdays_match); + } + if (info->monthdays_match != XT_TIME_ALL_MONTHDAYS) { + printf("on "); + time_print_monthdays(info->monthdays_match, true); + } + if (info->date_start != 0) { + printf("starting from "); + time_print_date(info->date_start, NULL); + } + if (info->date_stop != INT_MAX) { + printf("until date "); + time_print_date(info->date_stop, NULL); + } + if (!(info->flags & XT_TIME_LOCAL_TZ)) + printf("UTC "); +} + +static void time_save(const void *ip, const struct xt_entry_match *match) +{ + const struct xt_time_info *info = (const void *)match->data; + unsigned int h, m, s; + + if (info->daytime_start != XT_TIME_MIN_DAYTIME || + info->daytime_stop != XT_TIME_MAX_DAYTIME) { + divide_time(info->daytime_start, &h, &m, &s); + printf("--timestart %02u:%02u:%02u ", h, m, s); + divide_time(info->daytime_stop, &h, &m, &s); + printf("--timestop %02u:%02u:%02u ", h, m, s); + } + if (info->monthdays_match != XT_TIME_ALL_MONTHDAYS) { + printf("--monthdays "); + time_print_monthdays(info->monthdays_match, false); + } + if (info->weekdays_match != XT_TIME_ALL_WEEKDAYS) { + printf("--weekdays "); + time_print_weekdays(info->weekdays_match); + printf(" "); + } + time_print_date(info->date_start, "--datestart"); + time_print_date(info->date_stop, "--datestop"); + if (!(info->flags & XT_TIME_LOCAL_TZ)) + printf("--utc "); +} + +static struct xtables_match time_match = { + .name = "time", + .family = NFPROTO_UNSPEC, + .version = XTABLES_VERSION, + .size = XT_ALIGN(sizeof(struct xt_time_info)), + .userspacesize = XT_ALIGN(sizeof(struct xt_time_info)), + .help = time_help, + .init = time_init, + .parse = time_parse, + .print = time_print, + .save = time_save, + .extra_opts = time_opts, +}; + +void _init(void) +{ + xtables_register_match(&time_match); +} |