Arturo Borrero | af72a05 | 2015-03-04 19:49:02 +0100 | [diff] [blame] | 1 | /* ebt_limit |
| 2 | * |
| 3 | * Authors: |
| 4 | * Tom Marshall <tommy@home.tig-grr.com> |
| 5 | * |
| 6 | * Mostly copied from iptables' limit match. |
| 7 | * |
| 8 | * September, 2003 |
| 9 | * |
| 10 | * Translated to use libxtables for ebtables-compat in 2015 by |
Arturo Borrero Gonzalez | 4bf10c6 | 2016-10-18 14:12:57 +0200 | [diff] [blame] | 11 | * Arturo Borrero Gonzalez <arturo@debian.org> |
Arturo Borrero | af72a05 | 2015-03-04 19:49:02 +0100 | [diff] [blame] | 12 | */ |
| 13 | |
| 14 | #include <stdio.h> |
| 15 | #include <stdlib.h> |
| 16 | #include <string.h> |
| 17 | #include <getopt.h> |
| 18 | #include <errno.h> |
| 19 | #include <xtables.h> |
| 20 | #include <linux/netfilter_bridge/ebt_limit.h> |
| 21 | #include "iptables/nft.h" |
| 22 | #include "iptables/nft-bridge.h" |
| 23 | |
| 24 | #define EBT_LIMIT_AVG "3/hour" |
| 25 | #define EBT_LIMIT_BURST 5 |
| 26 | |
| 27 | #define FLAG_LIMIT 0x01 |
| 28 | #define FLAG_LIMIT_BURST 0x02 |
| 29 | #define ARG_LIMIT '1' |
| 30 | #define ARG_LIMIT_BURST '2' |
| 31 | |
| 32 | static struct option brlimit_opts[] = |
| 33 | { |
| 34 | { .name = "limit", .has_arg = true, .val = ARG_LIMIT }, |
| 35 | { .name = "limit-burst",.has_arg = true, .val = ARG_LIMIT_BURST }, |
| 36 | XT_GETOPT_TABLEEND, |
| 37 | }; |
| 38 | |
| 39 | static void brlimit_print_help(void) |
| 40 | { |
| 41 | printf( |
| 42 | "limit options:\n" |
| 43 | "--limit avg : max average match rate: default "EBT_LIMIT_AVG"\n" |
| 44 | " [Packets per second unless followed by \n" |
| 45 | " /sec /minute /hour /day postfixes]\n" |
| 46 | "--limit-burst number : number to match in a burst, -1 < number < 10001,\n" |
| 47 | " default %u\n", EBT_LIMIT_BURST); |
| 48 | } |
| 49 | |
| 50 | static int parse_rate(const char *rate, uint32_t *val) |
| 51 | { |
| 52 | const char *delim; |
| 53 | uint32_t r; |
| 54 | uint32_t mult = 1; /* Seconds by default. */ |
| 55 | |
| 56 | delim = strchr(rate, '/'); |
| 57 | if (delim) { |
| 58 | if (strlen(delim+1) == 0) |
| 59 | return 0; |
| 60 | |
| 61 | if (strncasecmp(delim+1, "second", strlen(delim+1)) == 0) |
| 62 | mult = 1; |
| 63 | else if (strncasecmp(delim+1, "minute", strlen(delim+1)) == 0) |
| 64 | mult = 60; |
| 65 | else if (strncasecmp(delim+1, "hour", strlen(delim+1)) == 0) |
| 66 | mult = 60*60; |
| 67 | else if (strncasecmp(delim+1, "day", strlen(delim+1)) == 0) |
| 68 | mult = 24*60*60; |
| 69 | else |
| 70 | return 0; |
| 71 | } |
| 72 | r = atoi(rate); |
| 73 | if (!r) |
| 74 | return 0; |
| 75 | |
| 76 | /* This would get mapped to infinite (1/day is minimum they |
| 77 | can specify, so we're ok at that end). */ |
| 78 | if (r / mult > EBT_LIMIT_SCALE) |
| 79 | return 0; |
| 80 | |
| 81 | *val = EBT_LIMIT_SCALE * mult / r; |
| 82 | return 1; |
| 83 | } |
| 84 | |
| 85 | static void brlimit_init(struct xt_entry_match *match) |
| 86 | { |
| 87 | struct ebt_limit_info *r = (struct ebt_limit_info *)match->data; |
| 88 | |
| 89 | parse_rate(EBT_LIMIT_AVG, &r->avg); |
| 90 | r->burst = EBT_LIMIT_BURST; |
| 91 | } |
| 92 | |
| 93 | static int brlimit_parse(int c, char **argv, int invert, unsigned int *flags, |
| 94 | const void *entry, struct xt_entry_match **match) |
| 95 | { |
| 96 | struct ebt_limit_info *r = (struct ebt_limit_info *)(*match)->data; |
| 97 | uintmax_t num; |
| 98 | |
| 99 | switch (c) { |
| 100 | case ARG_LIMIT: |
| 101 | EBT_CHECK_OPTION(flags, FLAG_LIMIT); |
| 102 | if (invert) |
| 103 | xtables_error(PARAMETER_PROBLEM, |
| 104 | "Unexpected `!' after --limit"); |
| 105 | if (!parse_rate(optarg, &r->avg)) |
| 106 | xtables_error(PARAMETER_PROBLEM, |
| 107 | "bad rate `%s'", optarg); |
| 108 | break; |
| 109 | case ARG_LIMIT_BURST: |
| 110 | EBT_CHECK_OPTION(flags, FLAG_LIMIT_BURST); |
| 111 | if (invert) |
| 112 | xtables_error(PARAMETER_PROBLEM, |
| 113 | "Unexpected `!' after --limit-burst"); |
| 114 | if (!xtables_strtoul(optarg, NULL, &num, 0, 10000)) |
| 115 | xtables_error(PARAMETER_PROBLEM, |
| 116 | "bad --limit-burst `%s'", optarg); |
| 117 | r->burst = num; |
| 118 | break; |
| 119 | default: |
| 120 | return 0; |
| 121 | } |
| 122 | |
| 123 | return 1; |
| 124 | } |
| 125 | |
| 126 | struct rates |
| 127 | { |
| 128 | const char *name; |
| 129 | uint32_t mult; |
| 130 | }; |
| 131 | |
| 132 | static struct rates g_rates[] = |
| 133 | { |
| 134 | { "day", EBT_LIMIT_SCALE*24*60*60 }, |
| 135 | { "hour", EBT_LIMIT_SCALE*60*60 }, |
| 136 | { "min", EBT_LIMIT_SCALE*60 }, |
| 137 | { "sec", EBT_LIMIT_SCALE } |
| 138 | }; |
| 139 | |
| 140 | static void print_rate(uint32_t period) |
| 141 | { |
| 142 | unsigned int i; |
| 143 | |
| 144 | for (i = 1; i < sizeof(g_rates)/sizeof(struct rates); i++) |
| 145 | if (period > g_rates[i].mult || |
| 146 | g_rates[i].mult/period < g_rates[i].mult%period) |
| 147 | break; |
| 148 | |
| 149 | printf("%u/%s ", g_rates[i-1].mult / period, g_rates[i-1].name); |
| 150 | } |
| 151 | |
| 152 | static void brlimit_print(const void *ip, const struct xt_entry_match *match, |
| 153 | int numeric) |
| 154 | { |
| 155 | struct ebt_limit_info *r = (struct ebt_limit_info *)match->data; |
| 156 | |
| 157 | printf("--limit "); |
| 158 | print_rate(r->avg); |
| 159 | printf("--limit-burst %u ", r->burst); |
| 160 | } |
| 161 | |
| 162 | static struct xtables_match brlimit_match = { |
| 163 | .name = "limit", |
| 164 | .revision = 0, |
| 165 | .version = XTABLES_VERSION, |
| 166 | .family = NFPROTO_BRIDGE, |
| 167 | .size = XT_ALIGN(sizeof(struct ebt_limit_info)), |
| 168 | .userspacesize = offsetof(struct ebt_limit_info, prev), |
| 169 | .init = brlimit_init, |
| 170 | .help = brlimit_print_help, |
| 171 | .parse = brlimit_parse, |
| 172 | .print = brlimit_print, |
| 173 | .extra_opts = brlimit_opts, |
| 174 | }; |
| 175 | |
| 176 | void _init(void) |
| 177 | { |
| 178 | xtables_register_match(&brlimit_match); |
| 179 | } |