WIP: support IPv6 on outer layer (backwards compatible)osmith/wip

Change-Id: I4212d847b6e1ad5ce120451a2d8a5578c48b90fe

5 files changed, 154 insertions, 39 deletions

diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index de3f614..76ed1d2 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -818,7 +818,7 @@ int ggsn_start(struct ggsn_ctx *ggsn)
 	LOGPGGSN(LOGL_INFO, ggsn, "Starting GGSN\n");
 
 	/* Start libgtp listener */
-	if (gtp_new(&ggsn->gsn, ggsn->cfg.state_dir, &ggsn->cfg.listen_addr.v4, GTP_MODE_GGSN)) {
+	if (gtp_new2(&ggsn->gsn, ggsn->cfg.state_dir, &ggsn->cfg.listen_addr, GTP_MODE_GGSN)) {
 		LOGPGGSN(LOGL_ERROR, ggsn, "Failed to create GTP: %s\n", strerror(errno));
 		return -1;
 	}
@@ -826,11 +826,10 @@ int ggsn_start(struct ggsn_ctx *ggsn)
 
 	/* patch in different addresses to use (in case we're behind NAT, the listen
 	 * address is different from what we advertise externally) */
-	if (ggsn->cfg.gtpc_addr.v4.s_addr)
-		ggsn->gsn->gsnc = ggsn->cfg.gtpc_addr.v4;
-
-	if (ggsn->cfg.gtpu_addr.v4.s_addr)
-		ggsn->gsn->gsnu = ggsn->cfg.gtpu_addr.v4;
+	if (ggsn->cfg.gtpc_addr.len)
+		gtp_set_gsnc(ggsn->gsn, &ggsn->cfg.gtpc_addr);
+	if (ggsn->cfg.gtpu_addr.len)
+		gtp_set_gsnu(ggsn->gsn, &ggsn->cfg.gtpu_addr);
 
 	/* Register File Descriptors */
 	osmo_fd_setup(&ggsn->gtp_fd0, ggsn->gsn->fd0, OSMO_FD_READ, ggsn_gtp_fd_cb, ggsn, 0);
diff --git a/gtp/gsn.c b/gtp/gsn.c
index 8cb1a47..3cdb61e 100644
--- a/gtp/gsn.c
+++ b/gtp/gsn.c
@@ -431,49 +431,65 @@ free_filename:
 	talloc_free(filename);
 }
 
-static int create_and_bind_socket(const char *name, struct gsn_t *gsn, int *fd, int domain,
-				  const struct in_addr *listen, int port)
+static int create_and_bind_socket(const char *name, struct gsn_t *gsn, int *fd, const struct in46_addr *listen,
+				  int port)
 {
-	struct sockaddr_in addr;
+	int family = in46a_to_af(listen);
 	int type = SOCK_DGRAM;
 	int protocol = 0;
-
-	*fd = socket(domain, type, protocol);
-
+	struct sockaddr addr = {0};
+	struct sockaddr_in *addr4 = (struct sockaddr_in *)&addr;
+	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&addr;
+	*fd = socket(family, type, protocol);
 	if (*fd < 0) {
 		rate_ctr_inc2(gsn->ctrg, GSN_CTR_ERR_SOCKET);
 		LOGP(DLGTP, LOGL_ERROR,
 		     "%s socket(domain=%d, type=%d, protocol=%d) failed: Error = %s\n",
-		     name, domain, type, protocol, strerror(errno));
+		     name, family, type, protocol, strerror(errno));
 		return -errno;
 	}
-
-	memset(&addr, 0, sizeof(addr));
-	addr.sin_family = domain;
-	addr.sin_addr = *listen;
-	addr.sin_port = htons(port);
+	switch (family) {
+	case AF_INET:
+		addr4->sin_family = AF_INET;
+		addr4->sin_addr = listen->v4;
+		addr4->sin_port = htons(port);
 #if defined(__FreeBSD__) || defined(__APPLE__)
-	addr.sin_len = sizeof(addr);
+		addr4->sin_len = sizeof(struct addr);
 #endif
-
-	if (bind(*fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+		break;
+	case AF_INET6:
+		addr6->sin6_family = AF_INET6;
+		addr6->sin6_addr = listen->v6;
+		addr6->sin6_port = htons(port);
+#if defined(__FreeBSD__) || defined(__APPLE__)
+		addr6->sin6_len = sizeof(struct addr);
+#endif
+		break;
+	default:
+		OSMO_ASSERT(false);
+		break;
+	}
+	if (bind(*fd, &addr, sizeof(addr)) < 0) {
 		rate_ctr_inc2(gsn->ctrg, GSN_CTR_ERR_SOCKET);
-		LOGP_WITH_ADDR(DLGTP, LOGL_ERROR, addr,
-			       "%s bind(fd=%d) failed: Error = %s\n",
-			       name, *fd, strerror(errno));
+		LOGP(DLGTP, LOGL_ERROR,
+		     "%s bind(fd=%d, addr=(%s:%d)) failed: Error = %s\n",
+		     name, *fd, in46a_ntoa(listen), port, strerror(errno));
 		return -errno;
 	}
-
 	return 0;
 }
 
-int gtp_new(struct gsn_t **gsn, char *statedir, struct in_addr *listen,
-	    int mode)
+int gtp_new2(struct gsn_t **gsn, char *statedir, struct in46_addr *listen, int mode)
 {
-	LOGP(DLGTP, LOGL_NOTICE, "GTP: gtp_newgsn() started at %s\n", inet_ntoa(*listen));
+	struct gsn_internal *internal;
+
+	LOGP(DLGTP, LOGL_NOTICE, "GTP: gtp_newgsn() started at %s\n", in46a_ntoa(listen));
 
 	*gsn = talloc_zero(gsn_ctx, struct gsn_t);
 
+	internal = talloc_zero(*gsn, struct gsn_internal);
+	(*gsn)->internal = internal;
+
 	(*gsn)->statedir = statedir;
 	log_restart(*gsn);
 
@@ -510,8 +526,8 @@ int gtp_new(struct gsn_t **gsn, char *statedir, struct in_addr *listen,
 
 	/* Store function parameters */
 	/* Same IP for user traffic and signalling */
-	(*gsn)->gsnc = *listen;
-	(*gsn)->gsnu = *listen;
+	gtp_set_gsnc(*gsn, listen);
+	gtp_set_gsnu(*gsn, listen);
 	(*gsn)->mode = mode;
 
 	(*gsn)->fd0 = -1;
@@ -519,15 +535,13 @@ int gtp_new(struct gsn_t **gsn, char *statedir, struct in_addr *listen,
 	(*gsn)->fd1u = -1;
 
 	/* Create GTP version 0 socket */
-	if (create_and_bind_socket("GTPv0", *gsn, &(*gsn)->fd0, AF_INET, listen, GTP0_PORT) < 0)
+	if (create_and_bind_socket("GTPv0", *gsn, &(*gsn)->fd0, listen, GTP0_PORT) < 0)
 		goto error;
-
 	/* Create GTP version 1 control plane socket */
-	if (create_and_bind_socket("GTPv1 control plane", *gsn, &(*gsn)->fd1c, AF_INET, listen, GTP1C_PORT) < 0)
+	if (create_and_bind_socket("GTPv1 control plane", *gsn, &(*gsn)->fd1c, listen, GTP1C_PORT) < 0)
 		goto error;
-
 	/* Create GTP version 1 user plane socket */
-	if (create_and_bind_socket("GTPv1 user plane", *gsn, &(*gsn)->fd1u, AF_INET, listen, GTP1U_PORT) < 0)
+	if (create_and_bind_socket("GTPv1 user plane", *gsn, &(*gsn)->fd1u, listen, GTP1U_PORT) < 0)
 		goto error;
 
 	/* Start internal queue timer */
@@ -540,6 +554,75 @@ error:
 	return -1;
 }
 
+/* IPv4 only, use gtp_new2 to support IPv6 too. */
+int gtp_new(struct gsn_t **gsn, char *statedir, struct in_addr *listen, int mode)
+{
+	struct in46_addr i46a = {0};
+
+	i46a.len = sizeof(struct in_addr);
+	i46a.v4 = *listen;
+
+	return gtp_new2(gsn, statedir, &i46a, mode);
+}
+
+void gtp_get_gsnc(const struct gsn_t *gsn, struct in46_addr *dest)
+{
+	struct gsn_internal *internal = gsn->internal;
+
+	if (internal->gsnc_is_v6) {
+		dest->len = sizeof(struct in6_addr);
+		dest->v6 = internal->gsnc6;
+	} else {
+		dest->len = sizeof(struct in_addr);
+		dest->v4 = gsn->gsnc;
+	}
+}
+
+void gtp_get_gsnu(const struct gsn_t *gsn, struct in46_addr *dest)
+{
+	struct gsn_internal *internal = gsn->internal;
+
+	if (internal->gsnu_is_v6) {
+		dest->len = sizeof(struct in6_addr);
+		dest->v6 = internal->gsnu6;
+	} else {
+		dest->len = sizeof(struct in_addr);
+		dest->v4 = gsn->gsnu;
+	}
+}
+
+void gtp_set_gsnc(struct gsn_t *gsn, const struct in46_addr *addr)
+{
+	struct gsn_internal *internal = gsn->internal;
+
+	if (in46a_to_af(addr) == AF_INET6) {
+		gsn->gsnc = (struct in_addr){0};
+		internal->gsnc6 = addr->v6;
+		internal->gsnc_is_v6 = true;
+
+	} else {
+		gsn->gsnc = addr->v4;
+		internal->gsnc6 = (struct in6_addr){0};
+		internal->gsnc_is_v6 = false;
+	}
+}
+
+void gtp_set_gsnu(struct gsn_t *gsn, const struct in46_addr *addr)
+{
+	struct gsn_internal *internal = gsn->internal;
+
+	if (in46a_to_af(addr) == AF_INET6) {
+		gsn->gsnu = (struct in_addr){0};
+		internal->gsnu6 = addr->v6;
+		internal->gsnu_is_v6 = true;
+
+	} else {
+		gsn->gsnu = addr->v4;
+		internal->gsnu6 = (struct in6_addr){0};
+		internal->gsnu_is_v6 = false;
+	}
+}
+
 int gtp_free(struct gsn_t *gsn)
 {
 
diff --git a/gtp/gsn_internal.h b/gtp/gsn_internal.h
index 732cb17..dbf8991 100644
--- a/gtp/gsn_internal.h
+++ b/gtp/gsn_internal.h
@@ -2,3 +2,13 @@
 #include <osmocom/core/in46_addr.h>
 
 void gtp_queue_timer_start(struct gsn_t *gsn);
+
+struct gsn_internal {
+	/* IP address of this gsn for signalling */
+	bool gsnc_is_v6;
+	struct in6_addr gsnc6;
+
+	/* IP address of this gsn for user traffic */
+	bool gsnu_is_v6;
+	struct in6_addr gsnu6;
+};
diff --git a/gtp/gtp.c b/gtp/gtp.c
index f426e6d..5843dfe 100644
--- a/gtp/gtp.c
+++ b/gtp/gtp.c
@@ -1067,6 +1067,14 @@ int gtp_create_pdp_resp(struct gsn_t *gsn, int version, struct pdp_t *pdp,
 			pdp->fd, pdp->seq, pdp->tid);
 }
 
+static void in46a_to_gsna(struct ul16_t *gsna, const struct in46_addr *src)
+{
+	memset(gsna, 0, sizeof(struct ul16_t));
+	gsna->l = src->len;
+	OSMO_ASSERT(gsna->l <= sizeof(gsna->v));
+	memcpy(gsna->v, &src->v6, gsna->l);
+}
+
 /* Handle Create PDP Context Request */
 int gtp_create_pdp_ind(struct gsn_t *gsn, int version,
 		       struct sockaddr_in *peer, int fd,
@@ -1083,6 +1091,7 @@ int gtp_create_pdp_ind(struct gsn_t *gsn, int version,
 	int hlen = get_hlen(pack);
 	uint8_t linked_nsapi = 0;
 	struct pdp_t *linked_pdp = NULL;
+	struct in46_addr addr;
 
 	if (!gtp_duplicate(gsn, version, peer, seq))
 		return 0;
@@ -1300,8 +1309,11 @@ int gtp_create_pdp_ind(struct gsn_t *gsn, int version,
 	}
 
 	/* Initialize our own IP addresses */
-	in_addr2gsna(&pdp->gsnlc, &gsn->gsnc);
-	in_addr2gsna(&pdp->gsnlu, &gsn->gsnu);
+	gtp_get_gsnc(gsn, &addr);
+	in46a_to_gsna(&pdp->gsnlc, &addr);
+
+	gtp_get_gsnu(gsn, &addr);
+	in46a_to_gsna(&pdp->gsnlu, &addr);
 
 	if (!gtp_pdp_getimsi(gsn, &pdp_old, pdp->imsi, pdp->nsapi)) {
 		/* Found old pdp with same tid. Now the voodoo begins! */
diff --git a/include/osmocom/gtp/gsn.h b/include/osmocom/gtp/gsn.h
index 936db9b..2db4fd4 100644
--- a/include/osmocom/gtp/gsn.h
+++ b/include/osmocom/gtp/gsn.h
@@ -17,6 +17,7 @@
 #include <osmocom/core/timer.h>
 #include <osmocom/core/tdef.h>
 #include <osmocom/core/rate_ctr.h>
+#include <osmocom/core/in46_addr.h>
 
 #include "pdp.h"
 
@@ -77,6 +78,9 @@ struct gsn_t {
 	int fd1c;		/* GTP1 control plane file descriptor */
 	int fd1u;		/* GTP0 user plane file descriptor */
 	int mode;		/* Mode of operation: GGSN or SGSN */
+
+	/* If you access gsnc and gsnu directly, only IPv4 is supported. Use
+	 * gtp_new2(), gtp_get_gsnc(), gtp_get_gsnu() to support IPv6 too. */
 	struct in_addr gsnc;	/* IP address of this gsn for signalling */
 	struct in_addr gsnu;	/* IP address of this gsn for user traffic */
 
@@ -113,12 +117,19 @@ struct gsn_t {
 
 	/* Timers: */
 	struct osmo_tdef *tdef;
+
+	void *internal;
 };
 
 /* External API functions */
 
-extern int gtp_new(struct gsn_t **gsn, char *statedir, struct in_addr *listen,
-		   int mode);
+extern int gtp_new(struct gsn_t **gsn, char *statedir, struct in_addr *listen, int mode);
+extern int gtp_new2(struct gsn_t **gsn, char *statedir, struct in46_addr *listen, int mode);
+
+extern void gtp_get_gsnc(const struct gsn_t *gsn, struct in46_addr *dest);
+extern void gtp_get_gsnu(const struct gsn_t *gsn, struct in46_addr *dest);
+extern void gtp_set_gsnu(struct gsn_t *gsn, const struct in46_addr *addr);
+extern void gtp_set_gsnc(struct gsn_t *gsn, const struct in46_addr *addr);
 
 extern int gtp_free(struct gsn_t *gsn);