--- /dev/null
+/* Shared library add-on to iptables to add ICMP support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+/* special hack for icmp-type 'any':
+ * Up to kernel <=2.4.20 the problem was:
+ * '-p icmp ' matches all icmp packets
+ * '-p icmp -m icmp' matches _only_ ICMP type 0 :(
+ * This is now fixed by initializing the field * to icmp type 0xFF
+ * See: https://bugzilla.netfilter.org/cgi-bin/bugzilla/show_bug.cgi?id=37
+ */
+
+struct icmp_names {
+ const char *name;
+ u_int8_t type;
+ u_int8_t code_min, code_max;
+};
+
+static const struct icmp_names icmp_codes[] = {
+ { "any", 0xFF, 0, 0xFF },
+ { "echo-reply", 0, 0, 0xFF },
+ /* Alias */ { "pong", 0, 0, 0xFF },
+
+ { "destination-unreachable", 3, 0, 0xFF },
+ { "network-unreachable", 3, 0, 0 },
+ { "host-unreachable", 3, 1, 1 },
+ { "protocol-unreachable", 3, 2, 2 },
+ { "port-unreachable", 3, 3, 3 },
+ { "fragmentation-needed", 3, 4, 4 },
+ { "source-route-failed", 3, 5, 5 },
+ { "network-unknown", 3, 6, 6 },
+ { "host-unknown", 3, 7, 7 },
+ { "network-prohibited", 3, 9, 9 },
+ { "host-prohibited", 3, 10, 10 },
+ { "TOS-network-unreachable", 3, 11, 11 },
+ { "TOS-host-unreachable", 3, 12, 12 },
+ { "communication-prohibited", 3, 13, 13 },
+ { "host-precedence-violation", 3, 14, 14 },
+ { "precedence-cutoff", 3, 15, 15 },
+
+ { "source-quench", 4, 0, 0xFF },
+
+ { "redirect", 5, 0, 0xFF },
+ { "network-redirect", 5, 0, 0 },
+ { "host-redirect", 5, 1, 1 },
+ { "TOS-network-redirect", 5, 2, 2 },
+ { "TOS-host-redirect", 5, 3, 3 },
+
+ { "echo-request", 8, 0, 0xFF },
+ /* Alias */ { "ping", 8, 0, 0xFF },
+
+ { "router-advertisement", 9, 0, 0xFF },
+
+ { "router-solicitation", 10, 0, 0xFF },
+
+ { "time-exceeded", 11, 0, 0xFF },
+ /* Alias */ { "ttl-exceeded", 11, 0, 0xFF },
+ { "ttl-zero-during-transit", 11, 0, 0 },
+ { "ttl-zero-during-reassembly", 11, 1, 1 },
+
+ { "parameter-problem", 12, 0, 0xFF },
+ { "ip-header-bad", 12, 0, 0 },
+ { "required-option-missing", 12, 1, 1 },
+
+ { "timestamp-request", 13, 0, 0xFF },
+
+ { "timestamp-reply", 14, 0, 0xFF },
+
+ { "address-mask-request", 17, 0, 0xFF },
+
+ { "address-mask-reply", 18, 0, 0xFF }
+};
+
+static void
+print_icmptypes(void)
+{
+ unsigned int i;
+ printf("Valid ICMP Types:");
+
+ for (i = 0; i < sizeof(icmp_codes)/sizeof(struct icmp_names); i++) {
+ if (i && icmp_codes[i].type == icmp_codes[i-1].type) {
+ if (icmp_codes[i].code_min == icmp_codes[i-1].code_min
+ && (icmp_codes[i].code_max
+ == icmp_codes[i-1].code_max))
+ printf(" (%s)", icmp_codes[i].name);
+ else
+ printf("\n %s", icmp_codes[i].name);
+ }
+ else
+ printf("\n%s", icmp_codes[i].name);
+ }
+ printf("\n");
+}
+
+/* Function which prints out usage message. */
+static void icmp_help(void)
+{
+ printf(
+"icmp match options:\n"
+" --icmp-type [!] typename match icmp type\n"
+" (or numeric type or type/code)\n");
+ print_icmptypes();
+}
+
+static const struct option icmp_opts[] = {
+ { "icmp-type", 1, NULL, '1' },
+ { .name = NULL }
+};
+
+static void
+parse_icmp(const char *icmptype, u_int8_t *type, u_int8_t code[])
+{
+ unsigned int limit = sizeof(icmp_codes)/sizeof(struct icmp_names);
+ unsigned int match = limit;
+ unsigned int i;
+
+ for (i = 0; i < limit; i++) {
+ if (strncasecmp(icmp_codes[i].name, icmptype, strlen(icmptype))
+ == 0) {
+ if (match != limit)
+ exit_error(PARAMETER_PROBLEM,
+ "Ambiguous ICMP type `%s':"
+ " `%s' or `%s'?",
+ icmptype,
+ icmp_codes[match].name,
+ icmp_codes[i].name);
+ match = i;
+ }
+ }
+
+ if (match != limit) {
+ *type = icmp_codes[match].type;
+ code[0] = icmp_codes[match].code_min;
+ code[1] = icmp_codes[match].code_max;
+ } else {
+ char *slash;
+ char buffer[strlen(icmptype) + 1];
+ unsigned int number;
+
+ strcpy(buffer, icmptype);
+ slash = strchr(buffer, '/');
+
+ if (slash)
+ *slash = '\0';
+
+ if (string_to_number(buffer, 0, 255, &number) == -1)
+ exit_error(PARAMETER_PROBLEM,
+ "Invalid ICMP type `%s'\n", buffer);
+ *type = number;
+ if (slash) {
+ if (string_to_number(slash+1, 0, 255, &number) == -1)
+ exit_error(PARAMETER_PROBLEM,
+ "Invalid ICMP code `%s'\n",
+ slash+1);
+ code[0] = code[1] = number;
+ } else {
+ code[0] = 0;
+ code[1] = 0xFF;
+ }
+ }
+}
+
+/* Initialize the match. */
+static void icmp_init(struct xt_entry_match *m)
+{
+ struct ipt_icmp *icmpinfo = (struct ipt_icmp *)m->data;
+
+ icmpinfo->type = 0xFF;
+ icmpinfo->code[1] = 0xFF;
+}
+
+/* Function which parses command options; returns true if it
+ ate an option */
+static int icmp_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_match **match)
+{
+ struct ipt_icmp *icmpinfo = (struct ipt_icmp *)(*match)->data;
+
+ switch (c) {
+ case '1':
+ if (*flags == 1)
+ exit_error(PARAMETER_PROBLEM,
+ "icmp match: only use --icmp-type once!");
+ check_inverse(optarg, &invert, &optind, 0);
+ parse_icmp(argv[optind-1], &icmpinfo->type,
+ icmpinfo->code);
+ if (invert)
+ icmpinfo->invflags |= IPT_ICMP_INV;
+ *flags = 1;
+ break;
+
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
+static void print_icmptype(u_int8_t type,
+ u_int8_t code_min, u_int8_t code_max,
+ int invert,
+ int numeric)
+{
+ if (!numeric) {
+ unsigned int i;
+
+ for (i = 0;
+ i < sizeof(icmp_codes)/sizeof(struct icmp_names);
+ i++) {
+ if (icmp_codes[i].type == type
+ && icmp_codes[i].code_min == code_min
+ && icmp_codes[i].code_max == code_max)
+ break;
+ }
+
+ if (i != sizeof(icmp_codes)/sizeof(struct icmp_names)) {
+ printf("%s%s ",
+ invert ? "!" : "",
+ icmp_codes[i].name);
+ return;
+ }
+ }
+
+ if (invert)
+ printf("!");
+
+ printf("type %u", type);
+ if (code_min == 0 && code_max == 0xFF)
+ printf(" ");
+ else if (code_min == code_max)
+ printf(" code %u ", code_min);
+ else
+ printf(" codes %u-%u ", code_min, code_max);
+}
+
+/* Prints out the union ipt_matchinfo. */
+static void icmp_print(const void *ip, const struct xt_entry_match *match,
+ int numeric)
+{
+ const struct ipt_icmp *icmp = (struct ipt_icmp *)match->data;
+
+ printf("icmp ");
+ print_icmptype(icmp->type, icmp->code[0], icmp->code[1],
+ icmp->invflags & IPT_ICMP_INV,
+ numeric);
+
+ if (icmp->invflags & ~IPT_ICMP_INV)
+ printf("Unknown invflags: 0x%X ",
+ icmp->invflags & ~IPT_ICMP_INV);
+}
+
+/* Saves the match in parsable form to stdout. */
+static void icmp_save(const void *ip, const struct xt_entry_match *match)
+{
+ const struct ipt_icmp *icmp = (struct ipt_icmp *)match->data;
+
+ if (icmp->invflags & IPT_ICMP_INV)
+ printf("! ");
+
+ /* special hack for 'any' case */
+ if (icmp->type == 0xFF) {
+ printf("--icmp-type any ");
+ } else {
+ printf("--icmp-type %u", icmp->type);
+ if (icmp->code[0] != 0 || icmp->code[1] != 0xFF)
+ printf("/%u", icmp->code[0]);
+ printf(" ");
+ }
+}
+
+static struct xtables_match icmp_mt_reg = {
+ .name = "icmp",
+ .version = XTABLES_VERSION,
+ .family = PF_INET,
+ .size = XT_ALIGN(sizeof(struct ipt_icmp)),
+ .userspacesize = XT_ALIGN(sizeof(struct ipt_icmp)),
+ .help = icmp_help,
+ .init = icmp_init,
+ .parse = icmp_parse,
+ .print = icmp_print,
+ .save = icmp_save,
+ .extra_opts = icmp_opts,
+};
+
+void _init(void)
+{
+ xtables_register_match(&icmp_mt_reg);
+}
git://git.onelab.eu / iptables.git / blobdiff