Unifies libip[6]t_esp.c into libxt_esp.c

1 files changed, 204 insertions, 0 deletions

diff --git a/extensions/libxt_esp.c b/extensions/libxt_esp.c
new file mode 100644
index 00000000..401c104a
--- /dev/null
+++ b/extensions/libxt_esp.c
@@ -0,0 +1,204 @@
+/* Shared library add-on to iptables to add ESP support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <errno.h>
+#include <xtables.h>
+#include <linux/netfilter/xt_esp.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+	printf(
+"ESP v%s options:\n"
+" --espspi [!] spi[:spi]\n"
+"				match spi (range)\n",
+IPTABLES_VERSION);
+}
+
+static struct option opts[] = {
+	{ "espspi", 1, 0, '1' },
+	{0}
+};
+
+static u_int32_t
+parse_esp_spi(const char *spistr)
+{
+	unsigned long int spi;
+	char* ep;
+
+	spi =  strtoul(spistr,&ep,0) ;
+
+	if ( spistr == ep ) {
+		exit_error(PARAMETER_PROBLEM,
+			   "ESP no valid digits in spi `%s'", spistr);
+	}
+	if ( spi == ULONG_MAX  && errno == ERANGE ) {
+		exit_error(PARAMETER_PROBLEM,
+			   "spi `%s' specified too big: would overflow", spistr);
+	}	
+	if ( *spistr != '\0'  && *ep != '\0' ) {
+		exit_error(PARAMETER_PROBLEM,
+			   "ESP error parsing spi `%s'", spistr);
+	}
+	return (u_int32_t) spi;
+}
+
+static void
+parse_esp_spis(const char *spistring, u_int32_t *spis)
+{
+	char *buffer;
+	char *cp;
+
+	buffer = strdup(spistring);
+	if ((cp = strchr(buffer, ':')) == NULL)
+		spis[0] = spis[1] = parse_esp_spi(buffer);
+	else {
+		*cp = '\0';
+		cp++;
+
+		spis[0] = buffer[0] ? parse_esp_spi(buffer) : 0;
+		spis[1] = cp[0] ? parse_esp_spi(cp) : 0xFFFFFFFF;
+		if (spis[0] > spis[1])
+			exit_error(PARAMETER_PROBLEM,
+				   "Invalid ESP spi range: %s", spistring);
+	}
+	free(buffer);
+}
+
+/* Initialize the match. */
+static void
+init(struct xt_entry_match *m, unsigned int *nfcache)
+{
+	struct xt_esp *espinfo = (struct xt_esp *)m->data;
+
+	espinfo->spis[1] = 0xFFFFFFFF;
+}
+
+#define ESP_SPI 0x01
+
+/* 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 void *entry,
+      unsigned int *nfcache,
+      struct xt_entry_match **match)
+{
+	struct xt_esp *espinfo = (struct xt_esp *)(*match)->data;
+
+	switch (c) {
+	case '1':
+		if (*flags & ESP_SPI)
+			exit_error(PARAMETER_PROBLEM,
+				   "Only one `--espspi' allowed");
+		check_inverse(optarg, &invert, &optind, 0);
+		parse_esp_spis(argv[optind-1], espinfo->spis);
+		if (invert)
+			espinfo->invflags |= XT_ESP_INV_SPI;
+		*flags |= ESP_SPI;
+		break;
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+/* Final check; we don't care. */
+static void
+final_check(unsigned int flags)
+{
+}
+
+static void
+print_spis(const char *name, u_int32_t min, u_int32_t max,
+	    int invert)
+{
+	const char *inv = invert ? "!" : "";
+
+	if (min != 0 || max != 0xFFFFFFFF || invert) {
+		if (min == max)
+			printf("%s:%s%u ", name, inv, min);
+		else
+			printf("%ss:%s%u:%u ", name, inv, min, max);
+	}
+}
+
+/* Prints out the union ipt_matchinfo. */
+static void
+print(const void *ip,
+      const struct xt_entry_match *match, int numeric)
+{
+	const struct xt_esp *esp = (struct xt_esp *)match->data;
+
+	printf("esp ");
+	print_spis("spi", esp->spis[0], esp->spis[1],
+		    esp->invflags & XT_ESP_INV_SPI);
+	if (esp->invflags & ~XT_ESP_INV_MASK)
+		printf("Unknown invflags: 0x%X ",
+		       esp->invflags & ~XT_ESP_INV_MASK);
+}
+
+/* Saves the union ipt_matchinfo in parsable form to stdout. */
+static void save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct xt_esp *espinfo = (struct xt_esp *)match->data;
+
+	if (!(espinfo->spis[0] == 0
+	    && espinfo->spis[1] == 0xFFFFFFFF)) {
+		printf("--espspi %s", 
+			(espinfo->invflags & XT_ESP_INV_SPI) ? "! " : "");
+		if (espinfo->spis[0]
+		    != espinfo->spis[1])
+			printf("%u:%u ",
+			       espinfo->spis[0],
+			       espinfo->spis[1]);
+		else
+			printf("%u ",
+			       espinfo->spis[0]);
+	}
+
+}
+
+static struct xtables_match esp = { 
+	.next 		= NULL,
+	.family		= AF_INET,
+	.name 		= "esp",
+	.version 	= IPTABLES_VERSION,
+	.size		= XT_ALIGN(sizeof(struct xt_esp)),
+	.userspacesize	= XT_ALIGN(sizeof(struct xt_esp)),
+	.help		= &help,
+	.init		= &init,
+	.parse		= &parse,
+	.final_check	= &final_check,
+	.print		= &print,
+	.save		= &save,
+	.extra_opts	= opts
+};
+
+static struct xtables_match esp6 = { 
+	.next 		= NULL,
+	.family		= AF_INET6,
+	.name 		= "esp",
+	.version 	= IPTABLES_VERSION,
+	.size		= XT_ALIGN(sizeof(struct xt_esp)),
+	.userspacesize	= XT_ALIGN(sizeof(struct xt_esp)),
+	.help		= &help,
+	.init		= &init,
+	.parse		= &parse,
+	.final_check	= &final_check,
+	.print		= &print,
+	.save		= &save,
+	.extra_opts	= opts
+};
+
+void
+_init(void)
+{
+	xtables_register_match(&esp);
+	xtables_register_match(&esp6);
+}