Revert "kernel-gtp: support IPv6 on outer layer"

This reverts commit 0917ce4e2271c0d71dfb8c86eb2d99821a374781,
as it breaks building osmo-sgsn. This needs to be reworked to be
backwards compatible.

Related: OS#6373
Change-Id: I2c2b2ff0875217e041d94c8e2cef030d2a86c2d8
diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index db906ea..0cd0feb 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -816,7 +816,7 @@
 	LOGPGGSN(LOGL_INFO, ggsn, "Starting GGSN\n");
 
 	/* Start libgtp listener */
-	if (gtp_new(&ggsn->gsn, ggsn->cfg.state_dir, &ggsn->cfg.listen_addr, GTP_MODE_GGSN)) {
+	if (gtp_new(&ggsn->gsn, ggsn->cfg.state_dir, &ggsn->cfg.listen_addr.v4, GTP_MODE_GGSN)) {
 		LOGPGGSN(LOGL_ERROR, ggsn, "Failed to create GTP: %s\n", strerror(errno));
 		return -1;
 	}
@@ -824,9 +824,11 @@
 
 	/* patch in different addresses to use (in case we're behind NAT, the listen
 	 * address is different from what we advertise externally) */
-	ggsn->gsn->gsnc = ggsn->cfg.gtpc_addr;
+	if (ggsn->cfg.gtpc_addr.v4.s_addr)
+		ggsn->gsn->gsnc = ggsn->cfg.gtpc_addr.v4;
 
-	ggsn->gsn->gsnu = ggsn->cfg.gtpu_addr;
+	if (ggsn->cfg.gtpu_addr.v4.s_addr)
+		ggsn->gsn->gsnu = ggsn->cfg.gtpu_addr.v4;
 
 	/* 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 c01d193..e66dc99 100644
--- a/gtp/gsn.c
+++ b/gtp/gsn.c
@@ -64,6 +64,11 @@
 
 /* Error reporting functions */
 
+#define LOGP_WITH_ADDR(ss, level, addr, fmt, args...)                    \
+		LOGP(ss, level, "addr(%s:%d) " fmt,                      \
+		     inet_ntoa((addr).sin_addr), htons((addr).sin_port), \
+		     ##args)
+
 static const struct rate_ctr_desc gsn_ctr_description[] = {
 	[GSN_CTR_ERR_SOCKET] = { "err:socket", "Socket error" },
 	[GSN_CTR_ERR_READFROM] = { "err:readfrom", "readfrom() errors" },
@@ -418,62 +423,46 @@
 	talloc_free(filename);
 }
 
-static int create_and_bind_socket(const char *name, struct gsn_t *gsn, int *fd, const struct in46_addr *listen,
-				  int port)
+static int create_and_bind_socket(const char *name, struct gsn_t *gsn, int *fd, int domain,
+				  const struct in_addr *listen, int port)
 {
-	int family = in46a_to_af(listen);
+	struct sockaddr_in addr;
 	int type = SOCK_DGRAM;
 	int protocol = 0;
-	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);
+	*fd = socket(domain, 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, family, type, protocol, strerror(errno));
+		     name, domain, type, protocol, strerror(errno));
 		return -errno;
 	}
 
-	switch (family) {
-	case AF_INET:
-		addr4->sin_family = AF_INET;
-		addr4->sin_addr = listen->v4;
-		addr4->sin_port = htons(port);
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family = domain;
+	addr.sin_addr = *listen;
+	addr.sin_port = htons(port);
 #if defined(__FreeBSD__) || defined(__APPLE__)
-		addr4->sin_len = sizeof(struct addr);
+	addr.sin_len = sizeof(addr);
 #endif
-		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) {
+	if (bind(*fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 		rate_ctr_inc2(gsn->ctrg, GSN_CTR_ERR_SOCKET);
-		LOGP(DLGTP, LOGL_ERROR,
-		     "%s bind(fd=%d, addr=(%s:%d)) failed: Error = %s\n",
-		     name, *fd, in46a_ntoa(listen), port, strerror(errno));
+		LOGP_WITH_ADDR(DLGTP, LOGL_ERROR, addr,
+			       "%s bind(fd=%d) failed: Error = %s\n",
+			       name, *fd, strerror(errno));
 		return -errno;
 	}
 
 	return 0;
 }
 
-int gtp_new(struct gsn_t **gsn, char *statedir, struct in46_addr *listen, int mode)
+int gtp_new(struct gsn_t **gsn, char *statedir, struct in_addr *listen,
+	    int mode)
 {
-	LOGP(DLGTP, LOGL_NOTICE, "GTP: gtp_newgsn() started at %s\n", in46a_ntoa(listen));
+	LOGP(DLGTP, LOGL_NOTICE, "GTP: gtp_newgsn() started at %s\n", inet_ntoa(*listen));
 
 	*gsn = calloc(sizeof(struct gsn_t), 1);	/* TODO */
 
@@ -522,15 +511,15 @@
 	(*gsn)->fd1u = -1;
 
 	/* Create GTP version 0 socket */
-	if (create_and_bind_socket("GTPv0", *gsn, &(*gsn)->fd0, listen, GTP0_PORT) < 0)
+	if (create_and_bind_socket("GTPv0", *gsn, &(*gsn)->fd0, AF_INET, listen, GTP0_PORT) < 0)
 		goto error;
 
 	/* Create GTP version 1 control plane socket */
-	if (create_and_bind_socket("GTPv1 control plane", *gsn, &(*gsn)->fd1c, listen, GTP1C_PORT) < 0)
+	if (create_and_bind_socket("GTPv1 control plane", *gsn, &(*gsn)->fd1c, AF_INET, listen, GTP1C_PORT) < 0)
 		goto error;
 
 	/* Create GTP version 1 user plane socket */
-	if (create_and_bind_socket("GTPv1 user plane", *gsn, &(*gsn)->fd1u, listen, GTP1U_PORT) < 0)
+	if (create_and_bind_socket("GTPv1 user plane", *gsn, &(*gsn)->fd1u, AF_INET, listen, GTP1U_PORT) < 0)
 		goto error;
 
 	/* Start internal queue timer */
diff --git a/gtp/gsn.h b/gtp/gsn.h
index df2f745..8e47ce3 100644
--- a/gtp/gsn.h
+++ b/gtp/gsn.h
@@ -18,7 +18,6 @@
 #include <osmocom/core/tdef.h>
 #include <osmocom/core/rate_ctr.h>
 
-#include "../lib/in46_addr.h"
 #include "pdp.h"
 
 #define GTP_MODE_GGSN 1
@@ -78,8 +77,8 @@
 	int fd1c;		/* GTP1 control plane file descriptor */
 	int fd1u;		/* GTP0 user plane file descriptor */
 	int mode;		/* Mode of operation: GGSN or SGSN */
-	struct in46_addr gsnc;	/* IP address of this gsn for signalling */
-	struct in46_addr gsnu;	/* IP address of this gsn for user traffic */
+	struct in_addr gsnc;	/* IP address of this gsn for signalling */
+	struct in_addr gsnu;	/* IP address of this gsn for user traffic */
 
 	/* Parameters related to signalling messages */
 	uint16_t seq_next;	/* Next sequence number to use */
@@ -118,7 +117,8 @@
 
 /* External API functions */
 
-extern int gtp_new(struct gsn_t **gsn, char *statedir, struct in46_addr *listen, int mode);
+extern int gtp_new(struct gsn_t **gsn, char *statedir, struct in_addr *listen,
+		   int mode);
 
 extern int gtp_free(struct gsn_t *gsn);
 
diff --git a/gtp/gtp.c b/gtp/gtp.c
index 86c456f..43e56b5 100644
--- a/gtp/gtp.c
+++ b/gtp/gtp.c
@@ -1297,8 +1297,8 @@
 	}
 
 	/* Initialize our own IP addresses */
-	in46a_to_gsna(&pdp->gsnlc, &gsn->gsnc);
-	in46a_to_gsna(&pdp->gsnlu, &gsn->gsnu);
+	in_addr2gsna(&pdp->gsnlc, &gsn->gsnc);
+	in_addr2gsna(&pdp->gsnlu, &gsn->gsnu);
 
 	if (!gtp_pdp_getimsi(gsn, &pdp_old, pdp->imsi, pdp->nsapi)) {
 		/* Found old pdp with same tid. Now the voodoo begins! */
diff --git a/lib/in46_addr.c b/lib/in46_addr.c
index d7c194f..648fe7e 100644
--- a/lib/in46_addr.c
+++ b/lib/in46_addr.c
@@ -376,14 +376,6 @@
 	return 1;
 }
 
-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);
-}
-
 void in46a_from_gsna(const struct ul16_t *in, struct in46_addr *dst)
 {
 	dst->len = in->l;
diff --git a/lib/in46_addr.h b/lib/in46_addr.h
index 59f58fc..5589f94 100644
--- a/lib/in46_addr.h
+++ b/lib/in46_addr.h
@@ -40,5 +40,4 @@
 	return addr->len == sizeof(struct in_addr);
 }
 
-void in46a_to_gsna(struct ul16_t *gsna, const struct in46_addr *src);
 void in46a_from_gsna(const struct ul16_t *in, struct in46_addr *dst);
diff --git a/sgsnemu/sgsnemu.c b/sgsnemu/sgsnemu.c
index f5ed671..7893f4f 100644
--- a/sgsnemu/sgsnemu.c
+++ b/sgsnemu/sgsnemu.c
@@ -59,7 +59,6 @@
 #include "../lib/syserr.h"
 #include "../lib/netns.h"
 #include "../lib/icmpv6.h"
-#include "../lib/in46_addr.h"
 #include "../gtp/pdp.h"
 #include "../gtp/gtp.h"
 #include "cmdline.h"
@@ -118,7 +117,7 @@
 	int pingsize;
 	int pingcount;
 	int pingquiet;
-	struct in46_addr listen;
+	struct in_addr listen;
 	struct in_addr remote;
 	struct in_addr dns;
 	int contexts;		/* Number of contexts to create */
@@ -460,10 +459,10 @@
 				args_info.listen_arg);
 			return -1;
 		} else {
-			options.listen.len = host->h_length;
-			memcpy(&options.listen.v6, host->h_addr, host->h_length);
+			memcpy(&options.listen.s_addr, host->h_addr,
+			       host->h_length);
 			printf("Local IP address is:   %s (%s)\n",
-			       args_info.listen_arg, in46a_ntoa(&options.listen));
+			       args_info.listen_arg, inet_ntoa(options.listen));
 		}
 	} else {
 		SYS_ERR(DSGSN, LOGL_ERROR, 0,
diff --git a/tests/gtp/Makefile.am b/tests/gtp/Makefile.am
index 4d4d2e3..ef69260 100644
--- a/tests/gtp/Makefile.am
+++ b/tests/gtp/Makefile.am
@@ -22,13 +22,11 @@
 gtpie_test_LDADD = \
 	$(top_builddir)/lib/debug.o \
 	$(top_builddir)/gtp/libgtp.la \
-	$(top_builddir)/lib/libmisc.a \
 	$(LIBOSMOCORE_LIBS) \
 	$(NULL)
 
 queue_test_LDADD = \
 	$(top_builddir)/lib/debug.o \
 	$(top_builddir)/gtp/libgtp.la \
-	$(top_builddir)/lib/libmisc.a \
 	$(LIBOSMOCORE_LIBS) \
 	$(NULL)