diff options
Diffstat (limited to 'extensions/libxt_connbytes.c')
| -rw-r--r-- | extensions/libxt_connbytes.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/extensions/libxt_connbytes.c b/extensions/libxt_connbytes.c new file mode 100644 index 0000000..b709627 --- /dev/null +++ b/extensions/libxt_connbytes.c @@ -0,0 +1,199 @@ +/* Shared library add-on to iptables to add byte tracking support. */ +#include <stdio.h> +#include <netdb.h> +#include <string.h> +#include <stdlib.h> +#include <getopt.h> +#include <xtables.h> +#include <linux/netfilter/nf_conntrack_common.h> +#include <linux/netfilter/xt_connbytes.h> + +static void connbytes_help(void) +{ + printf( +"connbytes match options:\n" +" [!] --connbytes from:[to]\n" +" --connbytes-dir [original, reply, both]\n" +" --connbytes-mode [packets, bytes, avgpkt]\n"); +} + +static const struct option connbytes_opts[] = { + { "connbytes", 1, NULL, '1' }, + { "connbytes-dir", 1, NULL, '2' }, + { "connbytes-mode", 1, NULL, '3' }, + { .name = NULL } +}; + +static void +parse_range(const char *arg, struct xt_connbytes_info *si) +{ + char *colon,*p; + + si->count.from = strtoul(arg,&colon,10); + if (*colon != ':') + xtables_error(PARAMETER_PROBLEM, "Bad range \"%s\"", arg); + si->count.to = strtoul(colon+1,&p,10); + if (p == colon+1) { + /* second number omited */ + si->count.to = 0xffffffff; + } + if (si->count.from > si->count.to) + xtables_error(PARAMETER_PROBLEM, "%llu should be less than %llu", + (unsigned long long)si->count.from, + (unsigned long long)si->count.to); +} + +static int +connbytes_parse(int c, char **argv, int invert, unsigned int *flags, + const void *entry, struct xt_entry_match **match) +{ + struct xt_connbytes_info *sinfo = (struct xt_connbytes_info *)(*match)->data; + unsigned long i; + + switch (c) { + case '1': + if (xtables_check_inverse(optarg, &invert, &optind, 0, argv)) + optind++; + + parse_range(optarg, sinfo); + if (invert) { + i = sinfo->count.from; + sinfo->count.from = sinfo->count.to; + sinfo->count.to = i; + } + *flags |= 1; + break; + case '2': + if (!strcmp(optarg, "original")) + sinfo->direction = XT_CONNBYTES_DIR_ORIGINAL; + else if (!strcmp(optarg, "reply")) + sinfo->direction = XT_CONNBYTES_DIR_REPLY; + else if (!strcmp(optarg, "both")) + sinfo->direction = XT_CONNBYTES_DIR_BOTH; + else + xtables_error(PARAMETER_PROBLEM, + "Unknown --connbytes-dir `%s'", optarg); + + *flags |= 2; + break; + case '3': + if (!strcmp(optarg, "packets")) + sinfo->what = XT_CONNBYTES_PKTS; + else if (!strcmp(optarg, "bytes")) + sinfo->what = XT_CONNBYTES_BYTES; + else if (!strcmp(optarg, "avgpkt")) + sinfo->what = XT_CONNBYTES_AVGPKT; + else + xtables_error(PARAMETER_PROBLEM, + "Unknown --connbytes-mode `%s'", optarg); + *flags |= 4; + break; + default: + return 0; + } + + return 1; +} + +static void connbytes_check(unsigned int flags) +{ + if (flags != 7) + xtables_error(PARAMETER_PROBLEM, "You must specify `--connbytes'" + "`--connbytes-dir' and `--connbytes-mode'"); +} + +static void print_mode(const struct xt_connbytes_info *sinfo) +{ + switch (sinfo->what) { + case XT_CONNBYTES_PKTS: + fputs("packets ", stdout); + break; + case XT_CONNBYTES_BYTES: + fputs("bytes ", stdout); + break; + case XT_CONNBYTES_AVGPKT: + fputs("avgpkt ", stdout); + break; + default: + fputs("unknown ", stdout); + break; + } +} + +static void print_direction(const struct xt_connbytes_info *sinfo) +{ + switch (sinfo->direction) { + case XT_CONNBYTES_DIR_ORIGINAL: + fputs("original ", stdout); + break; + case XT_CONNBYTES_DIR_REPLY: + fputs("reply ", stdout); + break; + case XT_CONNBYTES_DIR_BOTH: + fputs("both ", stdout); + break; + default: + fputs("unknown ", stdout); + break; + } +} + +static void +connbytes_print(const void *ip, const struct xt_entry_match *match, int numeric) +{ + const struct xt_connbytes_info *sinfo = (const void *)match->data; + + if (sinfo->count.from > sinfo->count.to) + printf("connbytes ! %llu:%llu ", + (unsigned long long)sinfo->count.to, + (unsigned long long)sinfo->count.from); + else + printf("connbytes %llu:%llu ", + (unsigned long long)sinfo->count.from, + (unsigned long long)sinfo->count.to); + + fputs("connbytes mode ", stdout); + print_mode(sinfo); + + fputs("connbytes direction ", stdout); + print_direction(sinfo); +} + +static void connbytes_save(const void *ip, const struct xt_entry_match *match) +{ + const struct xt_connbytes_info *sinfo = (const void *)match->data; + + if (sinfo->count.from > sinfo->count.to) + printf("! --connbytes %llu:%llu ", + (unsigned long long)sinfo->count.to, + (unsigned long long)sinfo->count.from); + else + printf("--connbytes %llu:%llu ", + (unsigned long long)sinfo->count.from, + (unsigned long long)sinfo->count.to); + + fputs("--connbytes-mode ", stdout); + print_mode(sinfo); + + fputs("--connbytes-dir ", stdout); + print_direction(sinfo); +} + +static struct xtables_match connbytes_match = { + .family = NFPROTO_UNSPEC, + .name = "connbytes", + .version = XTABLES_VERSION, + .size = XT_ALIGN(sizeof(struct xt_connbytes_info)), + .userspacesize = XT_ALIGN(sizeof(struct xt_connbytes_info)), + .help = connbytes_help, + .parse = connbytes_parse, + .final_check = connbytes_check, + .print = connbytes_print, + .save = connbytes_save, + .extra_opts = connbytes_opts, +}; + +void libxt_connbytes_init(void) +{ + xtables_register_match(&connbytes_match); +} |