Add configure flag to disable ipv6 support

Change-Id: I651a12d63d025bde61dcbc3c6b949cd0fed43580

configure.ac

@@ -64,13 +64,20 @@ dnl GTP Linux kernel dependencies
 AC_ARG_ENABLE([gtp-linux],
 	AS_HELP_STRING([--enable-gtp-linux], [Build GTP tunneling Linux kernel]),
 	[enable_gtp_linux="$enableval"], [enable_gtp_linux="no"])
-
 AS_IF([test "x$enable_gtp_linux" = "xyes"], [
 	PKG_CHECK_MODULES([LIBGTPNL], [libgtpnl >= 1.0.0])
 ])
-
 AM_CONDITIONAL([ENABLE_GTP_KERNEL], [test "$enable_gtp_linux" = "yes"])
 
+# Enable/disable IPv6 support
+AC_ARG_ENABLE([ipv6], [AS_HELP_STRING([--enable-ipv6], [Build IPv6 support])],
+    [enable_ipv6="$enableval"],[enable_ipv6="yes"])
+if test "x$enable_ipv6" = "xyes" ; then
+    AC_DEFINE(BUILD_IPv6, 1, [Define if we want to build IPv6 support])
+fi
+AM_CONDITIONAL(BUILD_IPv6, test "x$enable_ipv6" = "xyes")
+#AC_SUBST(enable_ipv6)
+
 # Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
@@ -170,4 +177,5 @@ AC_OUTPUT
 
 echo "
 osmo-ggsn Configuration:
-  GTP Linux kernel support:			${enable_gtp_linux}"
+  GTP Linux kernel support:			${enable_gtp_linux}
+  IPv6 support:		                       	${enable_ipv6}"

ggsn/Makefile.am

@@ -12,7 +12,10 @@ osmo_ggsn_LDADD += -lgtpnl
 endif
 
 osmo_ggsn_DEPENDENCIES = ../gtp/libgtp.la ../lib/libmisc.a
-osmo_ggsn_SOURCES = ggsn_vty.c ggsn.c ggsn.h gtp-kernel.h icmpv6.c icmpv6.h checksum.c checksum.h
+osmo_ggsn_SOURCES = ggsn_vty.c ggsn.c ggsn.h gtp-kernel.h checksum.c checksum.h
+if BUILD_IPv6
+osmo_ggsn_SOURCES += icmpv6.c icmpv6.h
+endif
 
 if ENABLE_GTP_KERNEL
 osmo_ggsn_SOURCES += gtp-kernel.c

ggsn/ggsn.c

@@ -65,7 +65,9 @@
 #include "../gtp/pdp.h"
 #include "../gtp/gtp.h"
 #include "gtp-kernel.h"
+#if defined(BUILD_IPv6)
 #include "icmpv6.h"
+#endif
 #include "ggsn.h"
 
 void *tall_ggsn_ctx;
@@ -115,7 +117,9 @@ int apn_stop(struct apn_ctx *apn, bool force)
 	LOGPAPN(LOGL_NOTICE, apn, "%sStopping\n", force ? "FORCED " : "");
 	/* check if pools have any active PDP contexts and bail out */
 	pool_close_all_pdp(apn->v4.pool);
+#if defined(BUILD_IPv6)
 	pool_close_all_pdp(apn->v6.pool);
+#endif
 
 	/* shutdown whatever old state might be left */
 	if (apn->tun.tun) {
@@ -137,12 +141,13 @@ int apn_stop(struct apn_ctx *apn, bool force)
 		ippool_free(apn->v4.pool);
 		apn->v4.pool = NULL;
 	}
+#if defined(BUILD_IPv6)
 	if (apn->v6.pool) {
 		LOGPAPN(LOGL_INFO, apn, "Releasing IPv6 pool\n");
 		ippool_free(apn->v6.pool);
 		apn->v6.pool = NULL;
 	}
-
+#endif
 	apn->started = false;
 	return 0;
 }
@@ -155,9 +160,11 @@ static int alloc_ippool_blacklist(struct apn_ctx *apn, struct in46_prefix **blac
 
 	*blacklist = NULL;
 
+#if defined(BUILD_IPv6)
 	if (ipv6)
 		flags = IP_TYPE_IPv6_NONLINK;
 	else
+#endif
 		flags = IP_TYPE_IPv4;
 
 	while (1) {
@@ -191,7 +198,9 @@ static int alloc_ippool_blacklist(struct apn_ctx *apn, struct in46_prefix **blac
 int apn_start(struct apn_ctx *apn)
 {
 	int ippool_flags = IPPOOL_NONETWORK | IPPOOL_NOBROADCAST;
+#if defined(BUILD_IPv6)
 	struct in46_prefix ipv6_tun_linklocal_ip;
+#endif
 	struct in46_prefix *blacklist;
 	int blacklist_size;
 
@@ -226,7 +235,7 @@ int apn_start(struct apn_ctx *apn)
 				return -1;
 			}
 		}
-
+#if defined(BUILD_IPv6)
 		if (apn->v6.cfg.ifconfig_prefix.addr.len) {
 			LOGPAPN(LOGL_INFO, apn, "Setting tun IPv6 address %s\n",
 				in46p_ntoa(&apn->v6.cfg.ifconfig_prefix));
@@ -239,13 +248,13 @@ int apn_start(struct apn_ctx *apn)
 				return -1;
 			}
 		}
-
+#endif
 		if (apn->tun.cfg.ipup_script) {
 			LOGPAPN(LOGL_INFO, apn, "Running ip-up script %s\n",
 				apn->tun.cfg.ipup_script);
 			tun_runscript(apn->tun.tun, apn->tun.cfg.ipup_script);
 		}
-
+#if defined(BUILD_IPv6)
 		if (apn->cfg.apn_type_mask & (APN_TYPE_IPv6|APN_TYPE_IPv4v6)) {
 			if (tun_ip_local_get(apn->tun.tun, &ipv6_tun_linklocal_ip, 1, IP_TYPE_IPv6_LINK) < 1) {
 				LOGPAPN(LOGL_ERROR, apn, "Cannot obtain IPv6 link-local address of "
@@ -255,17 +264,20 @@ int apn_start(struct apn_ctx *apn)
 			}
 			apn->v6_lladdr = ipv6_tun_linklocal_ip.addr.v6;
 		}
+#endif
 
 		/* set back-pointer from TUN device to APN */
 		apn->tun.tun->priv = apn;
 		break;
 	case APN_GTPU_MODE_KERNEL_GTP:
 		LOGPAPN(LOGL_INFO, apn, "Opening Kernel GTP device %s\n", apn->tun.cfg.dev_name);
+#if defined(BUILD_IPv6)
 		if (apn->cfg.apn_type_mask & (APN_TYPE_IPv6|APN_TYPE_IPv4v6)) {
 			LOGPAPN(LOGL_ERROR, apn, "Kernel GTP currently supports only IPv4\n");
 			apn_stop(apn, false);
 			return -1;
 		}
+#endif
 		/* use GTP kernel module for data packet encapsulation */
 		if (gtp_kernel_init(apn->ggsn->gsn, apn->tun.cfg.dev_name,
 				    &apn->v4.cfg.ifconfig_prefix, apn->tun.cfg.ipup_script) < 0) {
@@ -294,6 +306,7 @@ int apn_start(struct apn_ctx *apn)
 		talloc_free(blacklist);
 	}
 
+#if defined(BUILD_IPv6)
 	/* Create IPv6 pool */
 	if (apn->v6.cfg.dynamic_prefix.addr.len) {
 		LOGPAPN(LOGL_INFO, apn, "Creating IPv6 pool %s\n",
@@ -310,6 +323,7 @@ int apn_start(struct apn_ctx *apn)
 		}
 		talloc_free(blacklist);
 	}
+#endif
 
 	LOGPAPN(LOGL_NOTICE, apn, "Successfully started\n");
 	apn->started = true;
@@ -468,6 +482,7 @@ static void process_pco(struct apn_ctx *apn, struct pdp_t *pdp)
 		build_ipcp_pco(msg, 0, &apn->v4.cfg.dns[0], &apn->v4.cfg.dns[1]);
 	}
 
+#if defined(BUILD_IPv6)
 	if (pco_contains_proto(&pdp->pco_req, PCO_P_DNS_IPv6_ADDR)) {
 		for (i = 0; i < ARRAY_SIZE(apn->v6.cfg.dns); i++) {
 			struct in46_addr *i46a = &apn->v6.cfg.dns[i];
@@ -476,6 +491,7 @@ static void process_pco(struct apn_ctx *apn, struct pdp_t *pdp)
 			msgb_t16lv_put(msg, PCO_P_DNS_IPv6_ADDR, i46a->len, i46a->v6.s6_addr);
 		}
 	}
+#endif
 
 	if (pco_contains_proto(&pdp->pco_req, PCO_P_DNS_IPv4_ADDR)) {
 		for (i = 0; i < ARRAY_SIZE(apn->v4.cfg.dns); i++) {
@@ -502,12 +518,14 @@ static bool apn_supports_ipv4(const struct apn_ctx *apn)
 	return false;
 }
 
+#if defined(BUILD_IPv6)
 static bool apn_supports_ipv6(const struct apn_ctx *apn)
 {
 	if (apn->v6.cfg.static_prefix.addr.len  || apn->v6.cfg.dynamic_prefix.addr.len)
 		return true;
 	return false;
 }
+#endif
 
 int create_context_ind(struct pdp_t *pdp)
 {
@@ -575,6 +593,7 @@ int create_context_ind(struct pdp_t *pdp)
 			gtp_create_context_resp(gsn, pdp, GTPCAUSE_SYS_FAIL);
 			return 0;
 		}
+#if defined(BUILD_IPv6)
 	} else if (addr.len == sizeof(struct in6_addr)) {
 		struct in46_addr tmp;
 
@@ -594,6 +613,7 @@ int create_context_ind(struct pdp_t *pdp)
 		/* use allocated 64bit prefix as lower 64bit, used as link id by MS */
 		memcpy(tmp.v6.s6_addr+8, &member->addr.v6, 8);
 		in46a_to_eua(&tmp, &pdp->eua);
+#endif
 	} else
 		OSMO_ASSERT(0);
 
@@ -635,7 +655,9 @@ static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
 	struct ippoolm_t *ipm;
 	struct in46_addr dst;
 	struct iphdr *iph = (struct iphdr *)pack;
+#if defined(BUILD_IPv6)
 	struct ip6_hdr *ip6h = (struct ip6_hdr *)pack;
+#endif
 	struct ippool_t *pool;
 
 	if (iph->version == 4) {
@@ -644,6 +666,7 @@ static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
 		dst.len = 4;
 		dst.v4.s_addr = iph->daddr;
 		pool = apn->v4.pool;
+#if defined(BUILD_IPv6)
 	} else if (iph->version == 6) {
 		/* Due to the fact that 3GPP requires an allocation of a
 		 * /64 prefix to each MS, we must instruct
@@ -652,6 +675,7 @@ static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
 		dst.len = 8;
 		dst.v6 = ip6h->ip6_dst;
 		pool = apn->v6.pool;
+#endif
 	} else {
 		LOGP(DTUN, LOGL_NOTICE, "non-IPv packet received from tun\n");
 		return -1;
@@ -673,16 +697,20 @@ static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
 	return 0;
 }
 
+#if defined(BUILD_IPv6)
 /* RFC3307 link-local scope multicast address */
 static const struct in6_addr all_router_mcast_addr = {
 	.s6_addr = { 0xff,0x02,0,0,  0,0,0,0, 0,0,0,0,  0,0,0,2 }
 };
+#endif
 
 /* MS-originated GTP1-U packet, needs to be sent via TUN device */
 static int encaps_tun(struct pdp_t *pdp, void *pack, unsigned len)
 {
 	struct iphdr *iph = (struct iphdr *)pack;
+#if defined(BUILD_IPv6)
 	struct ip6_hdr *ip6h = (struct ip6_hdr *)pack;
+#endif
 	struct tun_t *tun = (struct tun_t *)pdp->ipif;
 	struct apn_ctx *apn = tun->priv;
 
@@ -692,11 +720,13 @@ static int encaps_tun(struct pdp_t *pdp, void *pack, unsigned len)
 	LOGPPDP(LOGL_DEBUG, pdp, "Packet received: forwarding to tun\n");
 
 	switch (iph->version) {
+#if defined(BUILD_IPv6)
 	case 6:
 		/* daddr: all-routers multicast addr */
 		if (IN6_ARE_ADDR_EQUAL(&ip6h->ip6_dst, &all_router_mcast_addr))
 			return handle_router_mcast(pdp->gsn, pdp, &apn->v6_lladdr, pack, len);
 		break;
+#endif
 	case 4:
 		break;
 	default:

ggsn/ggsn_vty.c

@@ -334,8 +334,10 @@ static struct cmd_node apn_node = {
 
 static const struct value_string pdp_type_names[] = {
 	{ APN_TYPE_IPv4, "v4" },
+#if defined(BUILD_IPv6)
 	{ APN_TYPE_IPv6, "v6" },
 	{ APN_TYPE_IPv4v6, "v4v6" },
+#endif
 	{ 0, NULL }
 };
 
@@ -345,13 +347,17 @@ static const struct value_string apn_gtpu_mode_names[] = {
 	{ 0, NULL }
 };
 
-
+#if defined(BUILD_IPv6)
+#define V4V6V46_ARGS	"(v4|v6|v4v6)"
 #define V4V6V46_STRING	"IPv4(-only) PDP Type\n"	\
 			"IPv6(-only) PDP Type\n"	\
 			"IPv4v6 (dual-stack) PDP Type\n"
-
+#else
+#define V4V6V46_ARGS	"(v4)"
+#define V4V6V46_STRING	"IPv4(-only) PDP Type\n"
+#endif
 DEFUN(cfg_apn_type_support, cfg_apn_type_support_cmd,
-	"type-support (v4|v6|v4v6)",
+	"type-support " V4V6V46_ARGS,
 	"Enable support for PDP Type\n"
 	V4V6V46_STRING)
 {
@@ -363,7 +369,7 @@ DEFUN(cfg_apn_type_support, cfg_apn_type_support_cmd,
 }
 
 DEFUN(cfg_apn_no_type_support, cfg_apn_no_type_support_cmd,
-	"no type-support (v4|v6|v4v6)",
+	"no type-support " V4V6V46_ARGS,
 	NO_STR "Disable support for PDP Type\n"
 	V4V6V46_STRING)
 {
@@ -480,6 +486,7 @@ DEFUN(cfg_apn_no_ip_ifconfig, cfg_apn_no_ip_ifconfig_cmd,
 	return CMD_SUCCESS;
 }
 
+#if defined(BUILD_IPv6)
 DEFUN(cfg_apn_ipv6_prefix, cfg_apn_ipv6_prefix_cmd,
 	"ipv6 prefix (static|dynamic) X:X::X:X/M",
 	IP6_STR PREFIX_STR "IPv6 Address/Prefix-Length\n")
@@ -512,6 +519,7 @@ DEFUN(cfg_apn_no_ipv6_ifconfig, cfg_apn_no_ipv6_ifconfig_cmd,
 	memset(&apn->v6.cfg.ifconfig_prefix, 0, sizeof(apn->v6.cfg.ifconfig_prefix));
 	return CMD_SUCCESS;
 }
+#endif
 
 #define DNS_STRINGS "Configure DNS Server\n" "primary/secondary DNS\n" "IP address of DNS Sever\n"
 
@@ -528,6 +536,7 @@ DEFUN(cfg_apn_ip_dns, cfg_apn_ip_dns_cmd,
 	return CMD_SUCCESS;
 }
 
+#if defined(BUILD_IPv6)
 DEFUN(cfg_apn_ipv6_dns, cfg_apn_ipv6_dns_cmd,
 	"ipv6 dns <0-1> X:X::X:X",
 	IP6_STR DNS_STRINGS)
@@ -540,20 +549,27 @@ DEFUN(cfg_apn_ipv6_dns, cfg_apn_ipv6_dns_cmd,
 
 	return CMD_SUCCESS;
 }
+#endif
 
+#if defined(BUILD_IPv6)
+#define IPV46_ARGS "(ip|ipv6)"
+#else
+#define IPV46_ARGS "(ip)"
+#endif
 DEFUN(cfg_apn_no_dns, cfg_apn_no_dns_cmd,
-	"no (ip|ipv6) dns <0-1>",
+	"no " IPV46_ARGS " dns <0-1>",
 	NO_STR IP_STR IP6_STR "Disable DNS Server\n" "primary/secondary DNS\n")
 {
 	struct apn_ctx *apn = (struct apn_ctx *) vty->index;
-	struct in46_addr *a;
+	struct in46_addr *a = NULL;
 	int idx = atoi(argv[1]);
 
 	if (!strcmp(argv[0], "ip"))
 		a = &apn->v4.cfg.dns[idx];
+#if defined(BUILD_IPv6)
 	else
 		a = &apn->v6.cfg.dns[idx];
-
+#endif
 	memset(a, 0, sizeof(*a));
 
 	return CMD_SUCCESS;
@@ -656,6 +672,7 @@ static void config_write_apn(struct vty *vty, struct apn_ctx *apn)
 	if (apn->v4.cfg.ifconfig_prefix.addr.len)
 		vty_dump_prefix(vty, "  ip ifconfig", &apn->v4.cfg.ifconfig_prefix);
 
+#if defined(BUILD_IPv6)
 	/* IPv6 prefixes + DNS */
 	if (apn->v6.cfg.static_prefix.addr.len)
 		vty_dump_prefix(vty, "  ipv6 prefix static", &apn->v6.cfg.static_prefix);
@@ -668,7 +685,7 @@ static void config_write_apn(struct vty *vty, struct apn_ctx *apn)
 	}
 	if (apn->v6.cfg.ifconfig_prefix.addr.len)
 		vty_dump_prefix(vty, "  ipv6 ifconfig", &apn->v6.cfg.ifconfig_prefix);
-
+#endif
 	/* must be last */
 	vty_out(vty, "  %sshutdown%s", apn->cfg.shutdown ? "" : "no ", VTY_NEWLINE);
 }
@@ -704,8 +721,12 @@ static const char *print_gsnaddr(const struct ul16_t *in)
 	struct in46_addr in46;
 
 	in46.len = in->l;
+#if defined(BUILD_IPv6)
 	OSMO_ASSERT(in->l <= sizeof(in46.v6));
-	memcpy(&in46.v6, in->v, in->l);
+#else
+	OSMO_ASSERT(in->l <= sizeof(in46.v4));
+#endif
+	memcpy(&in46.v4, in->v, in->l);
 
 	return in46a_ntoa(&in46);
 }
@@ -781,7 +802,9 @@ static void ippool_show_pdp_contexts(struct vty *vty, struct ippool_t *pool)
 static void apn_show_pdp_contexts(struct vty *vty, struct apn_ctx *apn)
 {
 	ippool_show_pdp_contexts(vty, apn->v4.pool);
+#if defined(BUILD_IPv6)
 	ippool_show_pdp_contexts(vty, apn->v6.pool);
+#endif
 }
 
 DEFUN(show_pdpctx, show_pdpctx_cmd,
@@ -885,14 +908,16 @@ int ggsn_vty_init(void)
 	install_element(APN_NODE, &cfg_apn_ipdown_script_cmd);
 	install_element(APN_NODE, &cfg_apn_no_ipdown_script_cmd);
 	install_element(APN_NODE, &cfg_apn_ip_prefix_cmd);
-	install_element(APN_NODE, &cfg_apn_ipv6_prefix_cmd);
 	install_element(APN_NODE, &cfg_apn_ip_dns_cmd);
-	install_element(APN_NODE, &cfg_apn_ipv6_dns_cmd);
 	install_element(APN_NODE, &cfg_apn_no_dns_cmd);
 	install_element(APN_NODE, &cfg_apn_ip_ifconfig_cmd);
 	install_element(APN_NODE, &cfg_apn_no_ip_ifconfig_cmd);
+#if defined(BUILD_IPv6)
+	install_element(APN_NODE, &cfg_apn_ipv6_prefix_cmd);
+	install_element(APN_NODE, &cfg_apn_ipv6_dns_cmd);
 	install_element(APN_NODE, &cfg_apn_ipv6_ifconfig_cmd);
 	install_element(APN_NODE, &cfg_apn_no_ipv6_ifconfig_cmd);
+#endif
 	install_element(APN_NODE, &cfg_apn_gpdu_seq_cmd);
 	install_element(APN_NODE, &cfg_apn_no_gpdu_seq_cmd);
 

lib/in46_addr.c

@@ -28,9 +28,11 @@ int in46a_to_af(const struct in46_addr *in)
 	switch (in->len) {
 	case 4:
 		return AF_INET;
+#if defined(BUILD_IPv6)
 	case 8:
 	case 16:
 		return AF_INET6;
+#endif
 	default:
 		OSMO_ASSERT(0);
 		return -1;
@@ -41,17 +43,21 @@ int in46a_to_af(const struct in46_addr *in)
 int in46a_to_sas(struct sockaddr_storage *out, const struct in46_addr *in)
 {
 	struct sockaddr_in *sin = (struct sockaddr_in *)out;
+#if defined(BUILD_IPv6)
 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)out;
+#endif
 
 	switch (in->len) {
 	case 4:
 		sin->sin_family = AF_INET;
 		sin->sin_addr = in->v4;
 		break;
+#if defined(BUILD_IPv6)
 	case 16:
 		sin6->sin6_family = AF_INET6;
 		sin6->sin6_addr = in->v6;
 		break;
+#endif
 	default:
 		OSMO_ASSERT(0);
 		return -1;
@@ -98,7 +104,7 @@ const char *in46p_ntoa(const struct in46_prefix *in46p)
  *  \returns 1 in case they are equal; 0 otherwise */
 int in46a_equal(const struct in46_addr *a, const struct in46_addr *b)
 {
-	if (a->len == b->len && !memcmp(&a->v6, &b->v6, a->len))
+	if (a->len == b->len && !memcmp(&a->v4, &b->v4, a->len))
 		return 1;
 	else
 		return 0;
@@ -115,12 +121,13 @@ int in46a_prefix_equal(const struct in46_addr *a, const struct in46_addr *b)
 	else
 		len = a->len;
 
-	if (!memcmp(&a->v6, &b->v6, len))
+	if (!memcmp(&a->v4, &b->v4, len))
 		return 1;
 	else
 		return 0;
 }
 
+#if defined(BUILD_IPv6)
 /*! Match if IPv6 addr1 + addr2 are within same \a mask */
 static int ipv6_within_mask(const struct in6_addr *addr1, const struct in6_addr *addr2,
 			    const struct in6_addr *mask)
@@ -167,6 +174,7 @@ static void create_ipv6_netmask(struct in6_addr *netmask, int prefixlen)
 		*p_netmask = htonl(0xFFFFFFFF << (32 - prefixlen));
 	}
 }
+#endif
 
 /*! Determine if given \a addr is within given \a net + \a prefixlen
  *  Builds the netmask from \a net + \a prefixlen and matches it to \a addr
@@ -174,7 +182,9 @@ static void create_ipv6_netmask(struct in6_addr *netmask, int prefixlen)
 int in46a_within_mask(const struct in46_addr *addr, const struct in46_addr *net, size_t prefixlen)
 {
 	struct in_addr netmask;
+#if defined(BUILD_IPv6)
 	struct in6_addr netmask6;
+#endif
 
 	if (addr->len != net->len)
 		return 0;
@@ -186,9 +196,11 @@ int in46a_within_mask(const struct in46_addr *addr, const struct in46_addr *net,
 			return 1;
 		else
 			return 0;
+#if defined(BUILD_IPv6)
 	case 16:
 		create_ipv6_netmask(&netmask6, prefixlen);
 		return ipv6_within_mask(&addr->v6, &net->v6, &netmask6);
+#endif
 	default:
 		OSMO_ASSERT(0);
 		return 0;
@@ -210,6 +222,7 @@ static unsigned int ipv4_netmasklen(const struct in_addr *netmask)
 	return prefix;
 }
 
+#if defined(BUILD_IPv6)
 static unsigned int ipv6_netmasklen(const struct in6_addr *netmask)
 {
 	#if defined(__linux__)
@@ -235,6 +248,7 @@ static unsigned int ipv6_netmasklen(const struct in6_addr *netmask)
 
 	return prefix;
 }
+#endif
 
 /*! Convert netmask to prefix length representation
  *  \param[in] netmask in46_addr containing a netmask (consecutive list of 1-bit followed by consecutive list of 0-bit)
@@ -245,8 +259,10 @@ unsigned int in46a_netmasklen(const struct in46_addr *netmask)
 	switch (netmask->len) {
 	case 4:
 		return ipv4_netmasklen(&netmask->v4);
+#if defined(BUILD_IPv6)
 	case 16:
 		return ipv6_netmasklen(&netmask->v6);
+#endif
 	default:
 		OSMO_ASSERT(0);
 		return 0;
@@ -264,6 +280,7 @@ int in46a_to_eua(const struct in46_addr *src, struct ul66_t *eua)
 		eua->v[1] = PDP_EUA_TYPE_v4;
 		memcpy(&eua->v[2], &src->v4, 4);	/* Copy a 4 byte address */
 		break;
+#if defined(BUILD_IPv6)
 	case 8:
 	case 16:
 		eua->l = 18;
@@ -271,6 +288,7 @@ int in46a_to_eua(const struct in46_addr *src, struct ul66_t *eua)
 		eua->v[1] = PDP_EUA_TYPE_v6;
 		memcpy(&eua->v[2], &src->v6, 16);	/* Copy a 16 byte address */
 		break;
+#endif
 	default:
 		OSMO_ASSERT(0);
 		return -1;
@@ -296,6 +314,7 @@ int in46a_from_eua(const struct ul66_t *eua, struct in46_addr *dst)
 		else
 			dst->v4.s_addr = 0;
 		break;
+#if defined(BUILD_IPv6)
 	case PDP_EUA_TYPE_v6:
 		dst->len = 16;
 		if (eua->l >= 18)
@@ -303,6 +322,7 @@ int in46a_from_eua(const struct ul66_t *eua, struct in46_addr *dst)
 		else
 			memset(&dst->v6, 0, 16);
 		break;
+#endif
 	default:
 		return -1;
 	}

lib/in46_addr.h

@@ -4,13 +4,17 @@
 
 #include "../gtp/pdp.h"
 
+#include "config.h"
+
 /* a simple wrapper around an in6_addr to also contain the length of the address,
  * thereby implicitly indicating the address family of the address */
 struct in46_addr {
 	uint8_t len;
 	union {
 		struct in_addr v4;
+#if defined(BUILD_IPv6)
 		struct in6_addr v6;
+#endif
 	};
 };
 

lib/ippool.c

@@ -22,6 +22,8 @@
 #include "ippool.h"
 #include "lookup.h"
 
+#include "config.h"
+
 int ippool_printaddr(struct ippool_t *this)
 {
 	unsigned int n;
@@ -96,18 +98,24 @@ static unsigned long int ippool_hash4(struct in_addr *addr)
 	return lookup((unsigned char *)&addr->s_addr, sizeof(addr->s_addr), 0);
 }
 
+#if defined(BUILD_IPv6)
 static unsigned long int ippool_hash6(struct in6_addr *addr, unsigned int len)
 {
 	/* TODO: Review hash spread for IPv6 */
 	return lookup((unsigned char *)addr->s6_addr, len, 0);
 }
+#endif
 
 unsigned long int ippool_hash(struct in46_addr *addr)
 {
+#if defined(BUILD_IPv6)
 	if (addr->len == 4)
 		return ippool_hash4(&addr->v4);
 	else
 		return ippool_hash6(&addr->v6, addr->len);
+#else
+	return ippool_hash4(&addr->v4);
+#endif
 }
 
 /* Get IP address and mask */
@@ -148,11 +156,14 @@ int ippool_aton(struct in46_addr *addr, size_t *prefixlen, const char *pool_in,
 		*prefixlen = 32;
 		addr->len = sizeof(struct in_addr);
 		addr->v4 = ((struct sockaddr_in*)ai->ai_addr)->sin_addr;
-	} else {
+	}
+#if defined(BUILD_IPv6)
+	else {
 		*prefixlen = 128;
 		addr->len = sizeof(struct in6_addr);
 		addr->v6 = ((struct sockaddr_in6*)ai->ai_addr)->sin6_addr;
 	}
+#endif
 	freeaddrinfo(ai);
 
 	/* parse prefixlen */
@@ -177,7 +188,7 @@ int ippool_aton(struct in46_addr *addr, size_t *prefixlen, const char *pool_in,
 void in46a_inc(struct in46_addr *addr)
 {
 	size_t addrlen;
-	uint8_t *a = (uint8_t *)&addr->v6;
+	uint8_t *a = (uint8_t *)&addr->v4;
 	for (addrlen = addr->len; addrlen > 0; addrlen--) {
 		if (++a[addrlen-1])
 			break;
@@ -215,11 +226,12 @@ int ippool_new(struct ippool_t **this, const struct in46_prefix *dyn, const stru
 	} else {
 		addr = dyn->addr;
 		addrprefixlen = dyn->prefixlen;
+#if defined(BUILD_IPv6)
 		/* we want to work with /64 prefixes, i.e. allocate /64 prefixes rather
 		 * than /128 (single IPv6 addresses) */
 		if (addr.len == sizeof(struct in6_addr))
 			addr.len = 64/8;
-
+#endif
 		dynsize = (1 << (addr.len*8 - addrprefixlen));
 		if (flags & IPPOOL_NONETWORK)	/* Exclude network address from pool */
 			dynsize--;
@@ -404,8 +416,10 @@ int ippool_newip(struct ippool_t *this, struct ippoolm_t **member,
 	if (addr) {
 		if (addr->len == 4 && addr->v4.s_addr)
 			specified = 1;
+#if defined(BUILD_IPv6)
 		if (addr->len == 16 && !IN6_IS_ADDR_UNSPECIFIED(&addr->v6))
 			specified = 1;
+#endif
 	}
 
 	/* First check to see if this type of address is allowed */

lib/tun.c

@@ -62,7 +62,9 @@
 
 #if defined(__linux__)
 
+#if defined(BUILD_IPv6)
 #include <linux/ipv6.h>
+#endif
 
 static int tun_nlattr(struct nlmsghdr *n, int nsize, int type, void *d, int dlen)
 {
@@ -197,6 +199,7 @@ static int tun_setaddr4(struct tun_t *this, struct in_addr *addr,
 	return 0;
 }
 
+#if defined(BUILD_IPv6)
 static int tun_setaddr6(struct tun_t *this, struct in6_addr *addr, struct in6_addr *dstaddr,
 			size_t prefixlen)
 {
@@ -280,6 +283,7 @@ static int tun_setaddr6(struct tun_t *this, struct in6_addr *addr, struct in6_ad
 
 	return 0;
 }
+#endif /* BUILD_IPv6 */
 
 int tun_setaddr(struct tun_t *this, struct in46_addr *addr, struct in46_addr *dstaddr, size_t prefixlen)
 {
@@ -288,8 +292,10 @@ int tun_setaddr(struct tun_t *this, struct in46_addr *addr, struct in46_addr *ds
 	case 4:
 		netmask.s_addr = htonl(0xffffffff << (32 - prefixlen));
 		return tun_setaddr4(this, &addr->v4, dstaddr ? &dstaddr->v4 : NULL, &netmask);
+#if defined(BUILD_IPv6)
 	case 16:
 		return tun_setaddr6(this, &addr->v6, dstaddr ? &dstaddr->v6 : NULL, prefixlen);
+#endif
 	default:
 		return -1;
 	}
@@ -762,11 +768,13 @@ int tun_runscript(struct tun_t *tun, char *script)
  */
 int netdev_ip_local_get(const char *devname, struct in46_prefix *prefix_list, size_t prefix_size, int flags)
 {
+#if defined(BUILD_IPv6)
 	static const uint8_t ll_prefix[] = { 0xfe,0x80, 0,0, 0,0, 0,0 };
+	bool is_ipv6_ll;
+#endif
 	struct ifaddrs *ifaddr, *ifa;
 	struct in46_addr netmask;
 	size_t count = 0;
-	bool is_ipv6_ll;
 
 	if (getifaddrs(&ifaddr) == -1) {
 		return -1;
@@ -792,7 +800,7 @@ int netdev_ip_local_get(const char *devname, struct in46_prefix *prefix_list, si
 			}
 			count++;
 		}
-
+#if defined(BUILD_IPv6)
 		if (ifa->ifa_addr->sa_family == AF_INET6 && (flags & IP_TYPE_IPv6)) {
 			struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
 			struct sockaddr_in6 *netmask6 = (struct sockaddr_in6 *) ifa->ifa_netmask;
@@ -812,6 +820,7 @@ int netdev_ip_local_get(const char *devname, struct in46_prefix *prefix_list, si
 			}
 			count++;
 		}
+#endif
 	}
 
 	freeifaddrs(ifaddr);

sgsnemu/sgsnemu.c

@@ -936,10 +936,12 @@ static int process_options(int argc, char **argv)
 		options.tx_gpdu_seq = 1;
 
 	/* PDP Type */
-	if (!strcmp(args_info.pdp_type_arg, "v6"))
-		options.pdp_type = PDP_EUA_TYPE_v6;
-	else if (!strcmp(args_info.pdp_type_arg, "v4"))
+	if (!strcmp(args_info.pdp_type_arg, "v4"))
 		options.pdp_type = PDP_EUA_TYPE_v4;
+#if defined(BUILD_IPv6)
+	else if if (!strcmp(args_info.pdp_type_arg, "v6"))
+		options.pdp_type = PDP_EUA_TYPE_v6;
+#endif
 	else {
 		SYS_ERR(DSGSN, LOGL_ERROR, 0, "Unsupported/unknown PDP Type '%s'\n",
 			args_info.pdp_type_arg);
@@ -955,6 +957,7 @@ static int process_options(int argc, char **argv)
 
 }
 
+#if defined(BUILD_IPv6)
 /* read a single value from a /procc file, up to 255 bytes, callee-allocated */
 static char *proc_read(const char *path)
 {
@@ -989,6 +992,7 @@ static char *proc_ipv6_conf_read(const char *dev, const char *file)
 	snprintf(path, sizeof(path), fmt, dev, file);
 	return proc_read(path);
 }
+#endif
 
 static char *print_ipprot(int t)
 {
@@ -1323,8 +1327,10 @@ static int delete_context(struct pdp_t *pdp)
 	return 0;
 }
 
+#if defined(BUILD_IPv6)
 /* Link-Local address  prefix fe80::/64 */
 static const uint8_t ll_prefix[] = { 0xfe,0x80, 0,0, 0,0, 0,0 };
+#endif
 
 /* Callback for receiving messages from tun */
 static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
@@ -1332,7 +1338,9 @@ static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
 	struct iphash_t *ipm;
 	struct in46_addr src;
 	struct iphdr *iph = (struct iphdr *)pack;
+#if defined(BUILD_IPv6)
 	struct ip6_hdr *ip6h = (struct ip6_hdr *)pack;
+#endif
 
 	if (iph->version == 4) {
 		if (len < sizeof(*iph) || len < 4*iph->ihl) {
@@ -1341,6 +1349,7 @@ static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
 		}
 		src.len = 4;
 		src.v4.s_addr = iph->saddr;
+#if defined(BUILD_IPv6)
 	} else if (iph->version == 6) {
 		/* We only have a single entry in the hash table, and it consists of the link-local
 		 * address "fe80::prefix".  So we need to make sure to convert non-link-local source
@@ -1355,6 +1364,7 @@ static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
 			memcpy(&src.v6.s6_addr[0], ll_prefix, sizeof(ll_prefix));
 			memcpy(&src.v6.s6_addr[sizeof(ll_prefix)], ip6h->ip6_src.s6_addr, 16-sizeof(ll_prefix));
 		}
+#endif
 	} else {
 		printf("Dropping packet with invalid IP version %u\n", iph->version);
 		return 0;
@@ -1416,6 +1426,7 @@ static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
 	       in46a_ntoa(&addr));
 
 	switch (addr.len) {
+#if defined(BUILD_IPv6)
 	case 16: /* IPv6 */
 		/* we have to enable the kernel to perform stateless autoconfiguration,
 		 * i.e. send a router solicitation using the lover 64bits of the allocated
@@ -1423,6 +1434,7 @@ static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
 		memcpy(addr.v6.s6_addr, ll_prefix, sizeof(ll_prefix));
 		printf("Derived IPv6 link-local address: %s\n", in46a_ntoa(&addr));
 		break;
+#endif
 	case 4: /* IPv4 */
 		break;
 	}
@@ -1443,6 +1455,7 @@ static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
 			tun_runscript(tun, options.ipup);
 	}
 
+#if defined(BUILD_IPv6)
 	/* now that ip-up has been executed, check if we are configured to
 	 * accept router advertisements */
 	if (options.createif && options.pdp_type == PDP_EUA_TYPE_v6) {
@@ -1463,6 +1476,7 @@ static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
 		free(accept_ra);
 		free(forwarding);
 	}
+#endif
 
 	ipset((struct iphash_t *)pdp->peer, &addr);
 

tests/lib/in46a_test.c

@@ -20,29 +20,37 @@ static const struct in46_addr g_ia4 = {
 	.v4.s_addr = 0x0d0c0b0a,
 };
 
+#if defined(BUILD_IPv6)
 static const struct in46_addr g_ia6 = {
 	.len = 16,
 	.v6.s6_addr = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 },
 };
+#endif
 
 static void test_in46a_to_af(void)
 {
+#if defined(BUILD_IPv6)
 	struct in46_addr ia;
+#endif
 
 	printf("Testing in46a_to_af()\n");
 
 	OSMO_ASSERT(in46a_to_af(&g_ia4) == AF_INET);
+#if defined(BUILD_IPv6)
 	OSMO_ASSERT(in46a_to_af(&g_ia6) == AF_INET6);
 
 	ia.len = 8;
 	OSMO_ASSERT(in46a_to_af(&ia) == AF_INET6);
+#endif
 }
 
 static void test_in46a_to_sas(void)
 {
 	struct sockaddr_storage ss;
 	struct sockaddr_in *sin = (struct sockaddr_in *) &ss;
+#if defined(BUILD_IPv6)
 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &ss;
+#endif
 
 	printf("Testing in46a_to_sas()\n");
 
@@ -51,10 +59,12 @@ static void test_in46a_to_sas(void)
 	OSMO_ASSERT(sin->sin_family == AF_INET);
 	OSMO_ASSERT(sin->sin_addr.s_addr == g_ia4.v4.s_addr);
 
+#if defined(BUILD_IPv6)
 	memset(&ss, 0, sizeof(ss));
 	OSMO_ASSERT(in46a_to_sas(&ss, &g_ia6) == 0);
 	OSMO_ASSERT(sin6->sin6_family == AF_INET6);
 	OSMO_ASSERT(!memcmp(&sin6->sin6_addr, &g_ia6.v6, sizeof(sin6->sin6_addr)));
+#endif
 }
 
 static void test_in46a_ntop(void)
@@ -79,10 +89,11 @@ static void test_in46a_ntop(void)
 	res = in46a_ntop(&ia, buf, sizeof(buf));
 	OSMO_ASSERT(res && !strcmp(res, "1.2.3.4"));
 	printf("res = %s\n", res);
-
+#if defined(BUILD_IPv6)
 	res = in46a_ntop(&g_ia6, buf, sizeof(buf));
 	OSMO_ASSERT(res && !strcmp(res, "102:304:506:708:90a:b0c:d0e:f10"));
 	printf("res = %s\n", res);
+#endif
 }
 
 static void test_in46p_ntoa(void)
@@ -108,11 +119,12 @@ static void test_in46a_equal(void)
 	b.v4.s_addr = g_ia4.v4.s_addr;
 	OSMO_ASSERT(in46a_equal(&g_ia4, &b));
 
+#if defined(BUILD_IPv6)
 	memset(&b, 0xff, sizeof(b));
 	b.len = g_ia6.len;
 	b.v6 = g_ia6.v6;
 	OSMO_ASSERT(in46a_equal(&g_ia6, &b));
-
+#endif
 }
 
 
@@ -155,10 +167,12 @@ static void test_in46a_within_mask(void)
 
 static void test_in46a_to_eua(void)
 {
+#if defined(BUILD_IPv6)
 	const struct in46_addr ia_v6_8 = {
 		.len = 8,
 		.v6.s6_addr = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 },
 	};
+#endif
 	struct ul66_t eua;
 
 	printf("testing in46a_to_eua()\n");
@@ -174,6 +188,7 @@ static void test_in46a_to_eua(void)
 	OSMO_ASSERT(eua.v[1] == PDP_EUA_TYPE_v4);
 	OSMO_ASSERT(osmo_load32le(&eua.v[2]) == g_ia4.v4.s_addr);
 
+#if defined(BUILD_IPv6)
 	/* IPv6 address */
 	OSMO_ASSERT(in46a_to_eua(&g_ia6, &eua) == 0);
 	OSMO_ASSERT(eua.v[0] == PDP_EUA_ORG_IETF);
@@ -185,6 +200,7 @@ static void test_in46a_to_eua(void)
 	OSMO_ASSERT(eua.v[0] == PDP_EUA_ORG_IETF);
 	OSMO_ASSERT(eua.v[1] == PDP_EUA_TYPE_v6);
 	OSMO_ASSERT(!memcmp(&eua.v[2], &ia_v6_8.v6, 16));
+#endif
 }
 
 static void test_in46a_from_eua(void)
@@ -193,10 +209,11 @@ static void test_in46a_from_eua(void)
 	struct ul66_t eua;
 	const uint8_t v4_unspec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v4 };
 	const uint8_t v4_spec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v4, 1,2,3,4 };
+#if defined(BUILD_IPv6)
 	const uint8_t v6_unspec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v6 };
 	const uint8_t v6_spec[] = { PDP_EUA_ORG_IETF, PDP_EUA_TYPE_v6,
 				    1,2,3,4,5,6,7,8,9,0xa,0xb,0xc,0xd,0xe,0xf,0x10 };
-
+#endif
 	memset(&eua, 0, sizeof(eua));
 
 	printf("Testing in46a_from_eua()\n");
@@ -232,6 +249,7 @@ static void test_in46a_from_eua(void)
 	OSMO_ASSERT(ia.len == 4);
 	OSMO_ASSERT(ia.v4.s_addr == htonl(0x01020304));
 
+#if defined(BUILD_IPv6)
 	/* unspecified V6 */
 	memcpy(eua.v, v6_unspec, sizeof(v6_unspec));
 	eua.l = sizeof(v6_unspec);
@@ -245,6 +263,7 @@ static void test_in46a_from_eua(void)
 	OSMO_ASSERT(in46a_from_eua(&eua, &ia) == 0);
 	OSMO_ASSERT(ia.len == 16);
 	OSMO_ASSERT(!memcmp(&ia.v6, v6_spec+2, ia.len));
+#endif
 }
 
 static void test_in46a_netmasklen(void)
@@ -275,6 +294,7 @@ static void test_in46a_netmasklen(void)
 	len = in46a_netmasklen(&netmask);
 	OSMO_ASSERT(len == 0);
 
+#if defined(BUILD_IPv6)
 	printf("Testing in46a_netmasklen() with IPv6 addresses\n");
 	const struct in46_addr netmaskA = {
 		.len = 16,
@@ -303,6 +323,7 @@ static void test_in46a_netmasklen(void)
 	};
 	len = in46a_netmasklen(&netmaskD);
 	OSMO_ASSERT(len == 0);
+#endif
 }
 
 int main(int argc, char **argv)