summaryrefslogtreecommitdiffstats
path: root/extensions/libebt_among.c
diff options
context:
space:
mode:
Diffstat (limited to 'extensions/libebt_among.c')
-rw-r--r--extensions/libebt_among.c243
1 files changed, 243 insertions, 0 deletions
diff --git a/extensions/libebt_among.c b/extensions/libebt_among.c
new file mode 100644
index 00000000..2b9a1b65
--- /dev/null
+++ b/extensions/libebt_among.c
@@ -0,0 +1,243 @@
+/* ebt_among
+ *
+ * Authors:
+ * Grzegorz Borowiak <grzes@gnu.univ.gda.pl>
+ *
+ * August, 2003
+ */
+
+#include <errno.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <xtables.h>
+#include <arpa/inet.h>
+#include <netinet/ether.h>
+#include <netinet/in.h>
+#include <linux/if_ether.h>
+#include <linux/netfilter_bridge/ebt_among.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include "iptables/nft.h"
+#include "iptables/nft-bridge.h"
+
+#define AMONG_DST '1'
+#define AMONG_SRC '2'
+#define AMONG_DST_F '3'
+#define AMONG_SRC_F '4'
+
+static const struct option bramong_opts[] = {
+ {"among-dst", required_argument, 0, AMONG_DST},
+ {"among-src", required_argument, 0, AMONG_SRC},
+ {"among-dst-file", required_argument, 0, AMONG_DST_F},
+ {"among-src-file", required_argument, 0, AMONG_SRC_F},
+ {0}
+};
+
+static void bramong_print_help(void)
+{
+ printf(
+"`among' options:\n"
+"--among-dst [!] list : matches if ether dst is in list\n"
+"--among-src [!] list : matches if ether src is in list\n"
+"--among-dst-file [!] file : obtain dst list from file\n"
+"--among-src-file [!] file : obtain src list from file\n"
+"list has form:\n"
+" xx:xx:xx:xx:xx:xx[=ip.ip.ip.ip],yy:yy:yy:yy:yy:yy[=ip.ip.ip.ip]"
+",...,zz:zz:zz:zz:zz:zz[=ip.ip.ip.ip][,]\n"
+"Things in brackets are optional.\n"
+"If you want to allow two (or more) IP addresses to one MAC address, you\n"
+"can specify two (or more) pairs with the same MAC, e.g.\n"
+" 00:00:00:fa:eb:fe=153.19.120.250,00:00:00:fa:eb:fe=192.168.0.1\n"
+ );
+}
+
+static void
+parse_nft_among_pair(char *buf, struct nft_among_pair *pair, bool have_ip)
+{
+ char *sep = index(buf, '=');
+ struct ether_addr *ether;
+
+ if (sep) {
+ *sep = '\0';
+
+ if (!inet_aton(sep + 1, &pair->in))
+ xtables_error(PARAMETER_PROBLEM,
+ "Invalid IP address '%s'\n", sep + 1);
+ }
+ ether = ether_aton(buf);
+ if (!ether)
+ xtables_error(PARAMETER_PROBLEM,
+ "Invalid MAC address '%s'\n", buf);
+ memcpy(&pair->ether, ether, sizeof(*ether));
+}
+
+static void
+parse_nft_among_pairs(struct nft_among_pair *pairs, char *buf,
+ size_t cnt, bool have_ip)
+{
+ size_t tmpcnt = 0;
+
+ buf = strtok(buf, ",");
+ while (buf) {
+ struct nft_among_pair pair = {};
+
+ parse_nft_among_pair(buf, &pair, have_ip);
+ nft_among_insert_pair(pairs, &tmpcnt, &pair);
+ buf = strtok(NULL, ",");
+ }
+}
+
+static size_t count_nft_among_pairs(char *buf)
+{
+ size_t cnt = 0;
+ char *p = buf;
+
+ if (!*buf)
+ return 0;
+
+ do {
+ cnt++;
+ p = index(++p, ',');
+ } while (p);
+
+ return cnt;
+}
+
+static bool nft_among_pairs_have_ip(char *buf)
+{
+ return !!index(buf, '=');
+}
+
+static int bramong_parse(int c, char **argv, int invert,
+ unsigned int *flags, const void *entry,
+ struct xt_entry_match **match)
+{
+ struct nft_among_data *data = (struct nft_among_data *)(*match)->data;
+ struct xt_entry_match *new_match;
+ bool have_ip, dst = false;
+ size_t new_size, cnt;
+ struct stat stats;
+ int fd = -1, poff;
+ long flen = 0;
+
+ switch (c) {
+ case AMONG_DST_F:
+ dst = true;
+ /* fall through */
+ case AMONG_SRC_F:
+ if ((fd = open(optarg, O_RDONLY)) == -1)
+ xtables_error(PARAMETER_PROBLEM,
+ "Couldn't open file '%s'", optarg);
+ if (fstat(fd, &stats) < 0)
+ xtables_error(PARAMETER_PROBLEM,
+ "fstat(%s) failed: '%s'",
+ optarg, strerror(errno));
+ flen = stats.st_size;
+ /* use mmap because the file will probably be big */
+ optarg = mmap(0, flen, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE, fd, 0);
+ if (optarg == MAP_FAILED)
+ xtables_error(PARAMETER_PROBLEM,
+ "Couldn't map file to memory");
+ if (optarg[flen-1] != '\n')
+ xtables_error(PARAMETER_PROBLEM,
+ "File should end with a newline");
+ if (strchr(optarg, '\n') != optarg+flen-1)
+ xtables_error(PARAMETER_PROBLEM,
+ "File should only contain one line");
+ optarg[flen-1] = '\0';
+ /* fall through */
+ case AMONG_DST:
+ if (c == AMONG_DST)
+ dst = true;
+ /* fall through */
+ case AMONG_SRC:
+ break;
+ default:
+ return 0;
+ }
+
+ cnt = count_nft_among_pairs(optarg);
+ if (cnt == 0)
+ return 0;
+
+ new_size = data->src.cnt + data->dst.cnt + cnt;
+ new_size *= sizeof(struct nft_among_pair);
+ new_size += XT_ALIGN(sizeof(struct xt_entry_match)) +
+ sizeof(struct nft_among_data);
+ new_match = xtables_calloc(1, new_size);
+ memcpy(new_match, *match, (*match)->u.match_size);
+ new_match->u.match_size = new_size;
+
+ data = (struct nft_among_data *)new_match->data;
+ have_ip = nft_among_pairs_have_ip(optarg);
+ poff = nft_among_prepare_data(data, dst, cnt, invert, have_ip);
+ parse_nft_among_pairs(data->pairs + poff, optarg, cnt, have_ip);
+
+ free(*match);
+ *match = new_match;
+
+ if (c == AMONG_DST_F || c == AMONG_SRC_F) {
+ munmap(argv, flen);
+ close(fd);
+ }
+ return 1;
+}
+
+static void __bramong_print(struct nft_among_pair *pairs,
+ int cnt, bool inv, bool have_ip)
+{
+ const char *isep = inv ? "! " : "";
+ int i;
+
+ for (i = 0; i < cnt; i++) {
+ printf("%s", isep);
+ isep = ",";
+
+ printf("%s", ether_ntoa(&pairs[i].ether));
+ if (pairs[i].in.s_addr != INADDR_ANY)
+ printf("=%s", inet_ntoa(pairs[i].in));
+ }
+ printf(" ");
+}
+
+static void bramong_print(const void *ip, const struct xt_entry_match *match,
+ int numeric)
+{
+ struct nft_among_data *data = (struct nft_among_data *)match->data;
+
+ if (data->src.cnt) {
+ printf("--among-src ");
+ __bramong_print(data->pairs,
+ data->src.cnt, data->src.inv, data->src.ip);
+ }
+ if (data->dst.cnt) {
+ printf("--among-dst ");
+ __bramong_print(data->pairs + data->src.cnt,
+ data->dst.cnt, data->dst.inv, data->dst.ip);
+ }
+}
+
+static struct xtables_match bramong_match = {
+ .name = "among",
+ .revision = 0,
+ .version = XTABLES_VERSION,
+ .family = NFPROTO_BRIDGE,
+ .size = XT_ALIGN(sizeof(struct nft_among_data)),
+ .userspacesize = XT_ALIGN(sizeof(struct nft_among_data)),
+ .help = bramong_print_help,
+ .parse = bramong_parse,
+ .print = bramong_print,
+ .extra_opts = bramong_opts,
+};
+
+void _init(void)
+{
+ xtables_register_match(&bramong_match);
+}