2 * Shared library add-on to iptables to match
3 * packets by their type (BROADCAST, UNICAST, MULTICAST).
5 * Michal Ludvig <michal@logix.cz>
12 #if defined(__GLIBC__) && __GLIBC__ == 2
13 #include <net/ethernet.h>
15 #include <linux/if_ether.h>
18 #include <linux/if_packet.h>
19 #include <linux/netfilter_ipv4/ipt_pkttype.h>
21 #define PKTTYPE_VERSION "0.1"
25 unsigned char pkttype;
26 unsigned char printhelp;
30 static const struct pkttypes supported_types[] = {
31 {"unicast", PACKET_HOST, 1, "to us"},
32 {"broadcast", PACKET_BROADCAST, 1, "to all"},
33 {"multicast", PACKET_MULTICAST, 1, "to group"},
35 {"otherhost", PACKET_OTHERHOST, 1, "to someone else"},
36 {"outgoing", PACKET_OUTGOING, 1, "outgoing of any type"},
39 {"bcast", PACKET_BROADCAST, 0, NULL},
40 {"mcast", PACKET_MULTICAST, 0, NULL},
41 {"host", PACKET_HOST, 0, NULL}
44 static void print_types()
48 printf("Valid packet types:\n");
49 for (i = 0; i < sizeof(supported_types)/sizeof(struct pkttypes); i++)
51 if(supported_types[i].printhelp == 1)
52 printf("\t%-14s\t\t%s\n", supported_types[i].name, supported_types[i].help);
57 /* Function which prints out usage message. */
58 static void help(void)
61 "pkt_type v%s options:\n"
62 " --pkt-type [!] packettype\tmatch packet type\n"
63 "\n", PKTTYPE_VERSION);
67 static struct option opts[] = {
68 {"pkt-type", 1, 0, '1'},
72 static void parse_pkttype(const char *pkttype, struct ipt_pkttype_info *info)
76 for (i = 0; i < sizeof(supported_types)/sizeof(struct pkttypes); i++)
78 if(strcasecmp(pkttype, supported_types[i].name)==0)
80 info->pkttype=supported_types[i].pkttype;
85 exit_error(PARAMETER_PROBLEM, "Bad packet type '%s'", pkttype);
88 static int parse(int c, char **argv, int invert, unsigned int *flags,
89 const struct ipt_entry *entry,
90 unsigned int *nfcache,
91 struct ipt_entry_match **match)
93 struct ipt_pkttype_info *info = (struct ipt_pkttype_info *)(*match)->data;
98 check_inverse(optarg, &invert, &optind, 0);
99 parse_pkttype(argv[optind-1], info);
112 static void final_check(unsigned int flags)
115 exit_error(PARAMETER_PROBLEM, "You must specify `--pkt-type'");
118 static void print_pkttype(struct ipt_pkttype_info *info)
122 for (i = 0; i < sizeof(supported_types)/sizeof(struct pkttypes); i++)
124 if(supported_types[i].pkttype==info->pkttype)
126 printf("%s ", supported_types[i].name);
131 printf("%d ", info->pkttype); /* in case we didn't find an entry in named-packtes */
134 static void print(const struct ipt_ip *ip, const struct ipt_entry_match *match, int numeric)
136 struct ipt_pkttype_info *info = (struct ipt_pkttype_info *)match->data;
138 printf("PKTTYPE %s= ", info->invert?"!":"");
142 static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
144 struct ipt_pkttype_info *info = (struct ipt_pkttype_info *)match->data;
146 printf("--pkt-type %s", info->invert?"! ":"");
150 static struct iptables_match pkttype = {
153 .version = IPTABLES_VERSION,
154 .size = IPT_ALIGN(sizeof(struct ipt_pkttype_info)),
155 .userspacesize = IPT_ALIGN(sizeof(struct ipt_pkttype_info)),
158 .final_check = &final_check,
166 register_match(&pkttype);