diff options
author | Marc Boucher <marc@mbsi.ca> | 2000-03-20 06:03:29 +0000 |
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committer | Marc Boucher <marc@mbsi.ca> | 2000-03-20 06:03:29 +0000 |
commit | e6869a8f59d779ff4d5a0984c86d80db70784962 (patch) | |
tree | cbaf2a4e3f8249de3967b959a214c27ff5fdee2a /extensions/libipt_state.c |
reorganized tree after kernel merge
Diffstat (limited to 'extensions/libipt_state.c')
-rw-r--r-- | extensions/libipt_state.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/extensions/libipt_state.c b/extensions/libipt_state.c new file mode 100644 index 00000000..19751d72 --- /dev/null +++ b/extensions/libipt_state.c @@ -0,0 +1,162 @@ +/* Shared library add-on to iptables to add state tracking support. */ +#include <stdio.h> +#include <netdb.h> +#include <string.h> +#include <stdlib.h> +#include <getopt.h> +#include <iptables.h> +#include <linux/netfilter_ipv4/ip_conntrack.h> +#include <linux/netfilter_ipv4/ipt_state.h> + +/* Function which prints out usage message. */ +static void +help(void) +{ + printf( +"state v%s options:\n" +" [!] --state [INVALID|ESTABLISHED|NEW|RELATED][,...]\n" +" State(s) to match\n" +"\n", NETFILTER_VERSION); +} + +static struct option opts[] = { + { "state", 1, 0, '1' }, + {0} +}; + +/* Initialize the match. */ +static void +init(struct ipt_entry_match *m, unsigned int *nfcache) +{ + /* Can't cache this */ + *nfcache |= NFC_UNKNOWN; +} + +static int +parse_state(const char *state, size_t strlen, struct ipt_state_info *sinfo) +{ + if (strncasecmp(state, "INVALID", strlen) == 0) + sinfo->statemask |= IPT_STATE_INVALID; + else if (strncasecmp(state, "NEW", strlen) == 0) + sinfo->statemask |= IPT_STATE_BIT(IP_CT_NEW); + else if (strncasecmp(state, "ESTABLISHED", strlen) == 0) + sinfo->statemask |= IPT_STATE_BIT(IP_CT_ESTABLISHED); + else if (strncasecmp(state, "RELATED", strlen) == 0) + sinfo->statemask |= IPT_STATE_BIT(IP_CT_RELATED); + else + return 0; + return 1; +} + +static void +parse_states(const char *arg, struct ipt_state_info *sinfo) +{ + const char *comma; + + while ((comma = strchr(arg, ',')) != NULL) { + if (comma == arg || !parse_state(arg, comma-arg, sinfo)) + exit_error(PARAMETER_PROBLEM, "Bad state `%s'", arg); + arg = comma+1; + } + + if (strlen(arg) == 0 || !parse_state(arg, strlen(arg), sinfo)) + exit_error(PARAMETER_PROBLEM, "Bad state `%s'", arg); +} + +/* Function which parses command options; returns true if it + ate an option */ +static int +parse(int c, char **argv, int invert, unsigned int *flags, + const struct ipt_entry *entry, + unsigned int *nfcache, + struct ipt_entry_match **match) +{ + struct ipt_state_info *sinfo = (struct ipt_state_info *)(*match)->data; + + switch (c) { + case '1': + if (check_inverse(optarg, &invert)) + optind++; + + parse_states(argv[optind-1], sinfo); + if (invert) + sinfo->statemask = ~sinfo->statemask; + *flags = 1; + break; + + default: + return 0; + } + + return 1; +} + +/* Final check; must have specified --state. */ +static void final_check(unsigned int flags) +{ + if (!flags) + exit_error(PARAMETER_PROBLEM, "You must specify `--state'"); +} + +static void print_state(unsigned int statemask) +{ + const char *sep = ""; + + if (statemask & IPT_STATE_INVALID) { + printf("%sINVALID", sep); + sep = ","; + } + if (statemask & IPT_STATE_BIT(IP_CT_NEW)) { + printf("%sNEW", sep); + sep = ","; + } + if (statemask & IPT_STATE_BIT(IP_CT_RELATED)) { + printf("%sRELATED", sep); + sep = ","; + } + if (statemask & IPT_STATE_BIT(IP_CT_ESTABLISHED)) { + printf("%sESTABLISHED", sep); + sep = ","; + } + printf(" "); +} + +/* Prints out the matchinfo. */ +static void +print(const struct ipt_ip *ip, + const struct ipt_entry_match *match, + int numeric) +{ + struct ipt_state_info *sinfo = (struct ipt_state_info *)match->data; + + printf("state "); + print_state(sinfo->statemask); +} + +/* Saves the matchinfo in parsable form to stdout. */ +static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match) +{ + struct ipt_state_info *sinfo = (struct ipt_state_info *)match->data; + + printf("--state "); + print_state(sinfo->statemask); +} + +struct iptables_match state += { NULL, + "state", + NETFILTER_VERSION, + sizeof(struct ipt_state_info), + &help, + &init, + &parse, + &final_check, + &print, + &save, + opts +}; + +void _init(void) +{ + register_match(&state); +} |