[XL] Change in libosmo-sccp[master]: ss7: Split asp and xua_server into their own files - gerrit-log

7 Sep 2023

pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmo-sccp/+/34329?usp=email )
Change subject: ss7: Split asp and xua_server into their own files
......................................................................
ss7: Split asp and xua_server into their own files
This allows having a clearer picture of the several entities involved,
as well as simplifying the files.
In the future, we can do the same for AS, route, etc. and leave osmo_ss7
for the "instance" object.
Change-Id: I3d43268459d61b0b9f9bec34bf31dc0851fa5e48
---
M src/Makefile.am
M src/osmo_ss7.c
A src/osmo_ss7_asp.c
A src/osmo_ss7_xua_srv.c
M src/ss7_internal.h
5 files changed, 1,588 insertions(+), 1,449 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/libosmo-sccp refs/changes/29/34329/1

diff --git a/src/Makefile.am b/src/Makefile.am
index 78336d1..d8f0bb6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -31,7 +31,8 @@
    		     sccp2sua.c sccp_scrc.c sccp_sclc.c sccp_scoc.c \
    		     sccp_user.c sccp_types.c sccp_lbcs.c sccp_scmg.c \
    		     xua_rkm.c xua_shared.c xua_default_lm_fsm.c \
-			     osmo_ss7.c osmo_ss7_hmrt.c xua_asp_fsm.c xua_as_fsm.c \
+			     osmo_ss7.c osmo_ss7_asp.c osmo_ss7_hmrt.c osmo_ss7_xua_srv.c \
+			     xua_asp_fsm.c xua_as_fsm.c \
    		     xua_snm.c osmo_ss7_vty.c sccp_vty.c ipa.c
 libosmo_sigtran_la_LDFLAGS = -version-info $(LIBVERSION) -no-undefined -export-symbols-regex '^osmo_'
 libosmo_sigtran_la_LIBADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) \
diff --git a/src/osmo_ss7.c b/src/osmo_ss7.c
index 2ba9766..9265898 100644
--- a/src/osmo_ss7.c
+++ b/src/osmo_ss7.c
@@ -1,6 +1,7 @@
 /* Core SS7 Instance/Linkset/Link/AS/ASP Handling */
/* (C) 2015-2017 by Harald Welte laforge@gnumonks.org
+ * (C) 2023 by sysmocom s.f.m.c. GmbH info@sysmocom.de
  * All Rights Reserved
  *
  * SPDX-License-Identifier: GPL-2.0+
@@ -55,7 +56,7 @@
#define MAX_PC_STR_LEN 32
-static bool ss7_initialized = false;
+bool ss7_initialized = false;
LLIST_HEAD(osmo_ss7_instances);
 static int32_t next_rctx = 1;
@@ -76,33 +77,6 @@
    { 0, NULL }
 };
-struct value_string osmo_ss7_asp_protocol_vals[] = {
-	{ OSMO_SS7_ASP_PROT_NONE,	"none" },
-	{ OSMO_SS7_ASP_PROT_SUA,	"sua" },
-	{ OSMO_SS7_ASP_PROT_M3UA,	"m3ua" },
-	{ OSMO_SS7_ASP_PROT_IPA,	"ipa" },
-	{ 0, NULL }
-};
-
-const struct value_string osmo_ss7_asp_role_names[] = {
-	{ OSMO_SS7_ASP_ROLE_ASP,	"ASP" },
-	{ OSMO_SS7_ASP_ROLE_SG,		"SG" },
-	{ OSMO_SS7_ASP_ROLE_IPSP,	"IPSP" },
-	{ 0, NULL }
-};
-
-static int asp_proto_to_ip_proto(enum osmo_ss7_asp_protocol proto)
-{
-	switch (proto) {
-	case OSMO_SS7_ASP_PROT_IPA:
-		return IPPROTO_TCP;
-	case OSMO_SS7_ASP_PROT_SUA:
-	case OSMO_SS7_ASP_PROT_M3UA:
-	default:
-		return IPPROTO_SCTP;
-	}
-}
-
 int osmo_ss7_find_free_rctx(struct osmo_ss7_instance *inst)
 {
    int32_t rctx;
@@ -125,60 +99,6 @@
    return -1;
 }
-static int _setsockopt_peer_primary_addr(int fd, const struct osmo_sockaddr *saddr)
-{
-	int rc;
-
-	struct sctp_setpeerprim so_sctp_setpeerprim = {0};
-
-	/* rfc6458 sec 8: "For the one-to-one style sockets and branched-off one-to-many
-	 * style sockets (see Section 9.2), this association ID parameter is ignored"
-	 */
-
-	/* NOTE: Requires setting:
-	 * - sysctl net.sctp.addip_enable = 1, otherwise EPERM is returned
-	 * - sysctl net.sctp.auth_enable = 1, RFC 5061 4.2.7 "An implementation supporting this
-	 *   extension MUST list the ASCONF,the ASCONF-ACK, and the AUTH chunks in
-	 *   its INIT and INIT-ACK parameters."
-	 */
-
-	so_sctp_setpeerprim.sspp_addr = saddr->u.sas;
-	rc = setsockopt(fd, IPPROTO_SCTP, SCTP_SET_PEER_PRIMARY_ADDR,
-			&so_sctp_setpeerprim, sizeof(so_sctp_setpeerprim));
-	if (rc < 0) {
-		char buf[128];
-		int err = errno;
-		strerror_r(err, (char *)buf, sizeof(buf));
-		LOGP(DLSS7, LOGL_ERROR, "setsockopt(SCTP_SET_PEER_PRIMARY_ADDR, %s) failed: %s%s\n",
-		     osmo_sockaddr_to_str(saddr), buf,
-		     err == EPERM ? " (EPERM: Make sure you have sysctl 'net.sctp.auth_enable' "
-				    "and 'net.sctp.addip_enable' set to 1)" : "");
-	}
-	return rc;
-}
-
-static int _setsockopt_primary_addr(int fd, const struct osmo_sockaddr *saddr)
-{
-	int rc;
-
-	struct sctp_prim so_sctp_prim = {0};
-
-	/* rfc6458 sec 8: "For the one-to-one style sockets and branched-off one-to-many
-	 * style sockets (see Section 9.2), this association ID parameter is ignored"
-	 */
-
-	so_sctp_prim.ssp_addr = saddr->u.sas;
-	rc = setsockopt(fd, IPPROTO_SCTP, SCTP_PRIMARY_ADDR,
-			&so_sctp_prim, sizeof(so_sctp_prim));
-	if (rc < 0) {
-		char buf[128];
-		strerror_r(errno, (char *)buf, sizeof(buf));
-		LOGP(DLSS7, LOGL_ERROR, "setsockopt(SCTP_PRIMARY_ADDR, %s) failed: %s\n",
-		     osmo_sockaddr_to_str(saddr), buf);
-	}
-	return rc;
-}
-
 /***********************************************************************
  * SS7 Point Code Parsing / Printing
  ***********************************************************************/
@@ -380,21 +300,6 @@
    }
 }
-static const uint16_t prot2port[] = {
-	[OSMO_SS7_ASP_PROT_NONE] = 0,
-	[OSMO_SS7_ASP_PROT_SUA] = SUA_PORT,
-	[OSMO_SS7_ASP_PROT_M3UA] = M3UA_PORT,
-	[OSMO_SS7_ASP_PROT_IPA] = 5000,
-};
-
-int osmo_ss7_asp_protocol_port(enum osmo_ss7_asp_protocol prot)
-{
-	if (prot >= ARRAY_SIZE(prot2port))
-		return -EINVAL;
-	else
-		return prot2port[prot];
-}
-
 /***********************************************************************
  * SS7 Instance
  ***********************************************************************/
@@ -1208,347 +1113,7 @@
    return as->fi->state == XUA_AS_S_DOWN;
 }
-/***********************************************************************
- * SS7 Application Server Process
- ***********************************************************************/
-
-enum ss7_asp_ctr {
-	SS7_ASP_CTR_PKT_RX_TOTAL,
-	SS7_ASP_CTR_PKT_RX_UNKNOWN,
-	SS7_ASP_CTR_PKT_TX_TOTAL,
-};
-
-static const struct rate_ctr_desc ss7_asp_rcd[] = {
-	[SS7_ASP_CTR_PKT_RX_TOTAL] = { "rx:packets:total", "Total number of packets received" },
-	[SS7_ASP_CTR_PKT_RX_UNKNOWN] = { "rx:packets:unknown", "Number of packets received for unknown PPID" },
-	[SS7_ASP_CTR_PKT_TX_TOTAL] = { "tx:packets:total", "Total number of packets transmitted" },
-};
-
-static const struct rate_ctr_group_desc ss7_asp_rcgd = {
-	.group_name_prefix = "sigtran_asp",
-	.group_description = "SIGTRAN Application Server Process",
-	.num_ctr = ARRAY_SIZE(ss7_asp_rcd),
-	.ctr_desc = ss7_asp_rcd,
-};
-static unsigned int g_ss7_asp_rcg_idx;
-
-void osmo_ss7_asp_peer_init(struct osmo_ss7_asp_peer *peer)
-{
-	memset(peer, 0, sizeof(*peer));
-	peer->idx_primary = -1;
-}
-
-int osmo_ss7_asp_peer_snprintf(char* buf, size_t buf_len, struct osmo_ss7_asp_peer *peer)
-{
-	int len = 0, offset = 0, rem = buf_len;
-	int ret, i;
-	char *after;
-	char *primary;
-
-	if (buf_len < 3)
-		return -EINVAL;
-
-	if (peer->host_cnt > 1) {
-		ret = snprintf(buf, rem, "(");
-		if (ret < 0)
-			return ret;
-		OSMO_SNPRINTF_RET(ret, rem, offset, len);
-	}
-	for (i = 0; i < peer->host_cnt; i++) {
-		primary = (peer->idx_primary == i) ? "*" : "";
-		if (peer->host_cnt == 1)
-			after = "";
-		else
-			after = (i == (peer->host_cnt - 1)) ? ")" : "|";
-		ret = snprintf(buf + offset, rem, "%s%s%s", peer->host[i] ? : "0.0.0.0", primary, after);
-		OSMO_SNPRINTF_RET(ret, rem, offset, len);
-	}
-	ret = snprintf(buf + offset, rem, ":%u", peer->port);
-	if (ret < 0)
-		return ret;
-	OSMO_SNPRINTF_RET(ret, rem, offset, len);
-
-	return len;
-}
-
-/*! \brief Set (copy) addresses for a given ASP peer. Previous addresses are freed.
- *  \param[in] peer Application Server Process peer whose addresses are to be set.
- *  \param[in] talloc_ctx talloc context used to allocate new addresses.
- *  \param[in] hosts Array of strings containing IP addresses.
- *  \param[in] host_cnt Number of strings in hosts
- *  \param[in] idx_primary Index in "hosts" array marking the SCTP Primary Address, -1 if no explicit Primary Address set
- *  \returns 0 on success; negative otherwise */
-int osmo_ss7_asp_peer_set_hosts2(struct osmo_ss7_asp_peer *peer, void *talloc_ctx, const char *const*hosts, size_t host_cnt, int idx_primary)
-{
-	int i = 0;
-
-	if (idx_primary >= (int)host_cnt || idx_primary < -1)
-		return -EINVAL;
-
-	if (host_cnt > ARRAY_SIZE(peer->host))
-		return -EINVAL;
-
-	for (; i < host_cnt; i++)
-		osmo_talloc_replace_string(talloc_ctx, &peer->host[i], hosts[i]);
-	for (; i < peer->host_cnt; i++) {
-			talloc_free(peer->host[i]);
-			peer->host[i] = NULL;
-	}
-
-	peer->host_cnt = host_cnt;
-	peer->idx_primary = idx_primary;
-	return 0;
-}
-
-/*! \brief Set (copy) addresses for a given ASP peer. Previous addresses are freed.
- *  \param[in] peer Application Server Process peer whose addresses are to be set.
- *  \param[in] talloc_ctx talloc context used to allocate new addresses.
- *  \param[in] hosts Array of strings containing IP addresses.
- *  \param[in] host_cnt Number of strings in hosts
- *  \returns 0 on success; negative otherwise */
-int osmo_ss7_asp_peer_set_hosts(struct osmo_ss7_asp_peer *peer, void *talloc_ctx, const char *const*hosts, size_t host_cnt)
-{
-	return osmo_ss7_asp_peer_set_hosts2(peer, talloc_ctx, hosts, host_cnt, -1);
-}
-
-/* Is string formatted IPv4/v6 addr considered IN(6)ADDR_ANY? */
-static inline bool host_is_ip_anyaddr(const char *host, bool is_v6)
-{
-	/* NULL addr is resolved as 0.0.0.0 (IPv4) by getaddrinfo(), most
-	 * probably for backward-compatibility reasons.
-	 */
-	return is_v6 ? (host && !strcmp(host, "::"))
-		     : (!host || !strcmp(host, "0.0.0.0"));
-}
-
-/*! \brief Append (copy) address to a given ASP peer. Previous addresses are kept.
- *  \param[in] peer Application Server Process peer the address is appended to.
- *  \param[in] talloc_ctx talloc context used to allocate new address.
- *  \param[in] host string containing an IP address.
- *  \param[in] is_primary_addr whether this IP address is to be added as SCTP Primary Address
- *  \returns 0 on success; negative otherwise */
-int osmo_ss7_asp_peer_add_host2(struct osmo_ss7_asp_peer *peer, void *talloc_ctx,
-			       const char *host, bool is_primary_addr)
-{
-	int i;
-	bool new_is_v6 = osmo_ip_str_type(host) == AF_INET6;
-	bool new_is_any = host_is_ip_anyaddr(host, new_is_v6);
-	struct osmo_sockaddr_str addr_str;
-
-	if (osmo_sockaddr_str_from_str(&addr_str, host, 0) < 0)
-		return -EINVAL;
-
-	if (new_is_any) {
-		/* Makes no sense to have INET(6)_ANY many times, or INET(6)_ANY
-		 * together with specific addresses, be it of same or different
-		 * IP version: */
-		if (peer->host_cnt != 0)
-			return -EINVAL;
-
-		/* Makes no sense to have INET(6)_ANY as primary: */
-		if (is_primary_addr)
-			return -EINVAL;
-
-		if (peer->host_cnt >= ARRAY_SIZE(peer->host))
-			return -EINVAL;
-		osmo_talloc_replace_string(talloc_ctx, &peer->host[peer->host_cnt], host);
-		peer->host_cnt++;
-		return 0;
-	}
-
-	/* Makes no sense to add specific address to set if INET(6)_ANY
-	 * is already set, be it from same or different IP version: */
-	for (i = 0; i < peer->host_cnt; i++) {
-		bool iter_is_v6 = osmo_ip_str_type(peer->host[i]) == AF_INET6;
-		if (host_is_ip_anyaddr(peer->host[i], iter_is_v6))
-			return -EINVAL;
-	}
-	/* Reached this point, no INET(6)_ANY address is set nor we are adding an INET(6)_ANY address. */
-
-	/* Check if address already exists, and then if primary flags need to be changed: */
-	for (i = 0; i < peer->host_cnt; i++) {
-		struct osmo_sockaddr_str it_addr_str;
-		bool it_is_primary;
-		osmo_sockaddr_str_from_str(&it_addr_str, peer->host[i], 0);
-
-		if (osmo_sockaddr_str_cmp(&addr_str, &it_addr_str) != 0)
-			continue;
-		it_is_primary = (peer->idx_primary == i);
-		if (is_primary_addr == it_is_primary) {
-			/* Nothing to do, return below */
-		} else if (is_primary_addr && !it_is_primary) {
-			/* Mark it as primary: */
-			peer->idx_primary = i;
-		} else { /* if (!is_primary_addr && it_is_primary) { */
-			/* mark it as non-primary: */
-			peer->idx_primary = -1;
-		}
-		return 0;
-	}
-
-	if (peer->host_cnt >= ARRAY_SIZE(peer->host))
-		return -EINVAL;
-
-	osmo_talloc_replace_string(talloc_ctx, &peer->host[peer->host_cnt], host);
-	if (is_primary_addr)
-		peer->idx_primary = peer->host_cnt;
-	peer->host_cnt++;
-	return 0;
-}
-
-/*! \brief Append (copy) address to a given ASP peer. Previous addresses are kept.
- *  \param[in] peer Application Server Process peer the address is appended to.
- *  \param[in] talloc_ctx talloc context used to allocate new address.
- *  \param[in] host string containing an IP address.
- *  \returns 0 on success; negative otherwise */
-int osmo_ss7_asp_peer_add_host(struct osmo_ss7_asp_peer *peer, void *talloc_ctx,
-			       const char *host)
-{
-	return osmo_ss7_asp_peer_add_host2(peer, talloc_ctx, host, false);
-}
-
-static int asp_apply_peer_primary_address(const struct osmo_ss7_asp *asp)
-{
-	struct osmo_fd *ofd;
-	struct osmo_sockaddr_str addr_str;
-	struct osmo_sockaddr addr;
-	uint16_t local_port;
-	int rc;
-
-	/* No SCTP Peer Primary Address explicitly configured, do nothing. */
-	if (asp->cfg.local.idx_primary == -1)
-		return 0;
-	OSMO_ASSERT(asp->cfg.local.idx_primary < asp->cfg.local.host_cnt);
-
-	if (asp->cfg.is_server)
-		ofd = osmo_stream_srv_get_ofd(asp->server);
-	else
-		ofd = osmo_stream_cli_get_ofd(asp->client);
-
-	if (asp->cfg.local.port == 0) {
-		char port_buf[16];
-		osmo_sock_get_local_ip_port(ofd->fd, port_buf, sizeof(port_buf));
-		local_port = atoi(port_buf);
-	} else {
-		local_port = asp->cfg.local.port;
-	}
-	rc = osmo_sockaddr_str_from_str(&addr_str,
-					asp->cfg.local.host[asp->cfg.local.idx_primary],
-					local_port);
-	if (rc < 0)
-		return rc;
-	rc = osmo_sockaddr_str_to_sockaddr(&addr_str, &addr.u.sas);
-	if (rc < 0)
-		return rc;
-	LOGPASP(asp, DLSS7, LOGL_INFO, "Set Peer's Primary Address %s\n",
-		osmo_sockaddr_to_str(&addr));
-	rc = _setsockopt_peer_primary_addr(ofd->fd, &addr);
-
-	return rc;
-}
-
-static int asp_apply_primary_address(const struct osmo_ss7_asp *asp)
-{
-	struct osmo_fd *ofd;
-	struct osmo_sockaddr_str addr_str;
-	struct osmo_sockaddr addr;
-	int rc;
-
-	/* No SCTP Primary Address explicitly configured, do nothing. */
-	if (asp->cfg.remote.idx_primary == -1)
-		return 0;
-	OSMO_ASSERT(asp->cfg.remote.idx_primary < asp->cfg.remote.host_cnt);
-
-	if (asp->cfg.is_server)
-		ofd = osmo_stream_srv_get_ofd(asp->server);
-	else
-		ofd = osmo_stream_cli_get_ofd(asp->client);
-
-	rc = osmo_sockaddr_str_from_str(&addr_str,
-					asp->cfg.remote.host[asp->cfg.remote.idx_primary],
-					asp->cfg.remote.port);
-	if (rc < 0)
-		return rc;
-	rc = osmo_sockaddr_str_to_sockaddr(&addr_str, &addr.u.sas);
-	if (rc < 0)
-		return rc;
-	LOGPASP(asp, DLSS7, LOGL_INFO, "Set Primary Address %s\n",
-		osmo_sockaddr_to_str(&addr));
-	rc = _setsockopt_primary_addr(ofd->fd, &addr);
-	return rc;
-}
-
-/* Returns whether the address signalled in the SCTP_PEER_ADDR_CHANGE matches
- * the user-configured Primary Address. */
-static bool sctp_peer_addr_change_ev_addr_matches_our_primary(const struct osmo_ss7_asp *asp,
-							      const union sctp_notification *notif)
-{
-	const char *primary_str;
-	int primary_str_type;
-	struct osmo_sockaddr ev_addr, primary;
-
-	OSMO_ASSERT(asp->cfg.remote.idx_primary >= 0);
-
-	primary_str = asp->cfg.remote.host[asp->cfg.remote.idx_primary];
-	primary_str_type = osmo_ip_str_type(primary_str);
-	memcpy(&ev_addr.u.sas, &notif->sn_paddr_change.spc_aaddr, sizeof(ev_addr.u.sas));
-
-	/* This whole switch is to properly compare addresses (take into account v6mapped IPv4 addresses): */
-	switch (ev_addr.u.sa.sa_family) {
-	case AF_INET:
-		switch (primary_str_type) {
-		case AF_INET:
-			primary = ev_addr; /* Copy AF + port */
-			inet_pton(AF_INET, primary_str, &primary.u.sin.sin_addr);
-			return (osmo_sockaddr_cmp(&primary, &ev_addr) == 0);
-		case AF_INET6:
-			/* for sure not the same */
-			return false;
-		}
-		return false;
-	case AF_INET6:
-		/* "ev_addr" can either be a IPv6 addr or a v6-mapped IPv4
-		 * address. Compare both as IPv6 (or v6-mapped IPv4) addresses. */
-		primary = ev_addr; /* Copy AF + port */
-		inet_pton(AF_INET6, primary_str, &primary.u.sin6.sin6_addr);
-		return (osmo_sockaddr_cmp(&primary, &ev_addr) == 0);
-	default:
-		return false;
-	}
-}
-
-/* Simple SCTP Path-manager tracking/driving the VTY-user-configured primary
- * address against the kernel when assoc state changes: */
-static void asp_handle_sctp_notif_monitor_primary_address(const struct osmo_ss7_asp *asp,
-							  const union sctp_notification *notif)
-{
-	bool match;
-
-	if (asp->cfg.remote.idx_primary == -1)
-		return;
-	if (notif->sn_header.sn_type != SCTP_PEER_ADDR_CHANGE)
-		return;
-
-	switch (notif->sn_paddr_change.spc_state) {
-	case SCTP_ADDR_AVAILABLE:
-	case SCTP_ADDR_ADDED:
-	case SCTP_ADDR_CONFIRMED:
-		/* If our primary addr became available/added/confirmed, set it */
-		match = sctp_peer_addr_change_ev_addr_matches_our_primary(asp, notif);
-		if (match)
-			asp_apply_primary_address(asp);
-		break;
-	case SCTP_ADDR_MADE_PRIM:
-		/* If another primary addr was made primary, overwrite it by setting it again */
-		match = sctp_peer_addr_change_ev_addr_matches_our_primary(asp, notif);
-		if (!match)
-			asp_apply_primary_address(asp);
-	default:
-		break;
-	}
-}
-
-static bool ipv6_sctp_supported(const char *host, bool bind)
+bool ss7_ipv6_sctp_supported(const char *host, bool bind)
 {
    int rc;
    struct addrinfo hints;
@@ -1574,46 +1139,6 @@
    return true;
 }
-/* Set default values for local and remote peer hosts if they are not yet set.
- *  \param[in] asp ASP for which to set default hosts.
- *  \returns true if values where changed, false otherwise.
- *
- * If the ASP is already started, osmo_ss7_asp_restart() must be called
- * afterwards in order to apply the new settings.
- * This API is internal, hence doesn't appear in osmo_ss7.h
- */
-bool ss7_asp_set_default_peer_hosts(struct osmo_ss7_asp *asp)
-{
-	bool changed = false;
-	/* If no local addr was set */
-	if (!asp->cfg.local.host_cnt) {
-		bool rem_has_v4 = false, rem_has_v6 = false;
-		int i;
-		for (i = 0; i < asp->cfg.remote.host_cnt; i++) {
-			if (osmo_ip_str_type(asp->cfg.remote.host[i]) == AF_INET6)
-				rem_has_v6 = true;
-			else
-				rem_has_v4 = true;
-		}
-		/* "::" Covers both IPv4 and IPv6, but if only IPv4
-		 * address are set on the remote side, IPv4 on the local
-		 * side must be set too */
-		if (ipv6_sctp_supported("::", true) && !(rem_has_v4 && !rem_has_v6))
-			osmo_ss7_asp_peer_add_host(&asp->cfg.local, asp, "::");
-		else
-			osmo_ss7_asp_peer_add_host(&asp->cfg.local, asp, "0.0.0.0");
-		changed = true;
-	}
-	/* If no remote addr was set */
-	if (!asp->cfg.remote.host_cnt) {
-		osmo_ss7_asp_peer_add_host(&asp->cfg.remote, asp, "127.0.0.1");
-		if (ipv6_sctp_supported("::1", false))
-			osmo_ss7_asp_peer_add_host(&asp->cfg.remote, asp, "::1");
-		changed = true;
-	}
-	return changed;
-}
-
 struct osmo_ss7_asp *
 osmo_ss7_asp_find_by_name(struct osmo_ss7_instance *inst, const char *name)
 {
@@ -1627,133 +1152,6 @@
    return NULL;
 }
-static uint16_t get_in_port(struct sockaddr *sa)
-{
-	switch (sa->sa_family) {
-	case AF_INET:
-		return (((struct sockaddr_in*)sa)->sin_port);
-	case AF_INET6:
-	        return (((struct sockaddr_in6*)sa)->sin6_port);
-	default:
-		return 0;
-	}
-}
-
-/* Converts string representation of v4-mappend-on-v6 IP addr to a pure IPv4 address.
- * Example: ::ffff:172.18.19.200 => 172.18.19.200
- */
-static void chop_v4_mapped_on_v6_prefix(char* buf)
-{
-	char *last_colon;
-	size_t len;
-	char *first_dot = strchr(buf, '.');
-
-	if (!first_dot)
-		return; /* Not an IPv4-mappend-on-v6 string representation, nothing to do */
-	last_colon = strrchr(buf, ':');
-	if (!last_colon)
-		return; /* pure IPv4 address, nothing to do */
-
-	len = strlen(last_colon + 1);
-	memmove(buf, last_colon + 1, len);
-	buf[len] = '\0';
-}
-
-/*! \brief Find an ASP definition matching the local+remote IP/PORT of given fd
- *  \param[in] fd socket descriptor of given socket
- *  \returns SS7 ASP in case a matching one is found; NULL otherwise */
-static struct osmo_ss7_asp *
-osmo_ss7_asp_find_by_socket_addr(int fd)
-{
-	struct osmo_ss7_instance *inst;
-	struct sockaddr_storage sa_l, sa_r;
-	socklen_t sa_len_l = sizeof(sa_l);
-	socklen_t sa_len_r = sizeof(sa_r);
-	char hostbuf_l[64], hostbuf_r[64];
-	uint16_t local_port, remote_port;
-	bool loc_is_v6, rem_is_v6;
-	int rc;
-	int i;
-
-	OSMO_ASSERT(ss7_initialized);
-	/* convert local and remote IP to string */
-	rc = getsockname(fd, (struct sockaddr*)&sa_l, &sa_len_l);
-	if (rc < 0)
-		return NULL;
-	rc = getnameinfo((struct sockaddr*)&sa_l, sa_len_l,
-			 hostbuf_l, sizeof(hostbuf_l),
-			 NULL, 0, NI_NUMERICHOST);
-	if (rc < 0)
-		return NULL;
-	local_port = ntohs(get_in_port((struct sockaddr*)&sa_l));
-
-	rc = getpeername(fd, (struct sockaddr*)&sa_r, &sa_len_r);
-	if (rc < 0)
-		return NULL;
-	rc = getnameinfo((struct sockaddr*)&sa_r, sa_len_r,
-			 hostbuf_r, sizeof(hostbuf_r),
-			 NULL, 0, NI_NUMERICHOST);
-	if (rc < 0)
-		return NULL;
-	remote_port = ntohs(get_in_port((struct sockaddr*)&sa_r));
-
-	/* If multi-home is used with both IPv4 and IPv6, then the socket is
-	 * AF_INET6, and then returned IPv4 addresses are actually v6mapped ones.
-	 * We need to convert them to IPv4 before matching.
-	 */
-	chop_v4_mapped_on_v6_prefix(hostbuf_l);
-	chop_v4_mapped_on_v6_prefix(hostbuf_r);
-	loc_is_v6 = osmo_ip_str_type(hostbuf_l) == AF_INET6;
-	rem_is_v6 = osmo_ip_str_type(hostbuf_r) == AF_INET6;
-
-	/* check all instances for any ASP definition matching the
-	 * address combination of local/remote ip/port */
-	llist_for_each_entry(inst, &osmo_ss7_instances, list) {
-		struct osmo_ss7_asp *asp;
-		llist_for_each_entry(asp, &inst->asp_list, list) {
-			if (asp->cfg.local.port != local_port)
-				continue;
-			if (asp->cfg.remote.port && asp->cfg.remote.port != remote_port)
-				continue;
-
-			for (i = 0; i < asp->cfg.local.host_cnt; i++) {
-				bool iter_is_v6 = osmo_ip_str_type(asp->cfg.local.host[i]) == AF_INET6;
-				bool iter_is_anyaddr = host_is_ip_anyaddr(asp->cfg.local.host[i], iter_is_v6);
-				/* "::" (v6) covers "0.0.0.0" (v4), but not otherwise */
-				if (iter_is_v6 != loc_is_v6 &&
-				    !(iter_is_v6 && iter_is_anyaddr))
-					continue;
-				if (iter_is_anyaddr ||
-				    !strcmp(asp->cfg.local.host[i], hostbuf_l))
-					break;
-			}
-			if (i == asp->cfg.local.host_cnt)
-				continue; /* didn't match any local.host */
-
-			/* If no remote host was set, it's probably a server and hence we match any cli src */
-			if (asp->cfg.remote.host_cnt) {
-				for (i = 0; i < asp->cfg.remote.host_cnt; i++) {
-					bool iter_is_v6 = osmo_ip_str_type(asp->cfg.remote.host[i]) == AF_INET6;
-					bool iter_is_anyaddr = host_is_ip_anyaddr(asp->cfg.remote.host[i], iter_is_v6);
-					/* "::" (v6) covers "0.0.0.0" (v4), but not otherwise */
-					if (iter_is_v6 != rem_is_v6 &&
-					    !(iter_is_v6 && iter_is_anyaddr))
-						continue;
-					if (iter_is_anyaddr ||
-					    !strcmp(asp->cfg.remote.host[i], hostbuf_r))
-						break;
-				}
-				if (i == asp->cfg.remote.host_cnt)
-					continue; /* didn't match any remote.host */
-			}
-
-			return asp;
-		}
-	}
-
-	return NULL;
-}
-
 /*! \brief Find an ASP that matches the given protocol.
  *  \param[in] as Application Server in which to look for \ref asp
  *  \returns SS7 ASP in case a matching one is found; NULL otherwise */
@@ -1789,38 +1187,6 @@
    return asp;
 }
-static struct osmo_ss7_asp *
-osmo_ss7_asp_alloc(struct osmo_ss7_instance *inst, const char *name,
-		   uint16_t remote_port, uint16_t local_port,
-		   enum osmo_ss7_asp_protocol proto)
-{
-	struct osmo_ss7_asp *asp = talloc_zero(inst, struct osmo_ss7_asp);
-	asp->ctrg = rate_ctr_group_alloc(asp, &ss7_asp_rcgd, g_ss7_asp_rcg_idx++);
-	if (!asp->ctrg) {
-		talloc_free(asp);
-		return NULL;
-	}
-	rate_ctr_group_set_name(asp->ctrg, name);
-	asp->inst = inst;
-	osmo_ss7_asp_peer_init(&asp->cfg.remote);
-	asp->cfg.remote.port = remote_port;
-	osmo_ss7_asp_peer_init(&asp->cfg.local);
-	asp->cfg.local.port = local_port;
-	asp->cfg.proto = proto;
-	asp->cfg.name = talloc_strdup(asp, name);
-
-	asp->cfg.T_defs_lm = talloc_memdup(asp, ss7_asp_lm_timer_defaults,
-					   sizeof(ss7_asp_lm_timer_defaults));
-	osmo_tdefs_reset(asp->cfg.T_defs_lm);
-
-	llist_add_tail(&asp->list, &inst->asp_list);
-
-	/* The SUA code internally needs SCCP to work */
-	if (proto == OSMO_SS7_ASP_PROT_SUA)
-		osmo_ss7_ensure_sccp(inst);
-	return asp;
-}
-
 struct osmo_ss7_asp *
 osmo_ss7_asp_find_or_create(struct osmo_ss7_instance *inst, const char *name,
    		    uint16_t remote_port, uint16_t local_port,
@@ -1838,630 +1204,9 @@
    	return asp;
    }
-	return osmo_ss7_asp_alloc(inst, name, remote_port, local_port, proto);
+	return ss7_asp_alloc(inst, name, remote_port, local_port, proto);
 }
-void osmo_ss7_asp_destroy(struct osmo_ss7_asp *asp)
-{
-	struct osmo_ss7_as *as;
-
-	OSMO_ASSERT(ss7_initialized);
-	LOGPASP(asp, DLSS7, LOGL_INFO, "Destroying ASP\n");
-
-	if (asp->server)
-		osmo_stream_srv_destroy(asp->server);
-	if (asp->client)
-		osmo_stream_cli_destroy(asp->client);
-	if (asp->fi)
-		osmo_fsm_inst_term(asp->fi, OSMO_FSM_TERM_REQUEST, NULL);
-	if (asp->xua_server)
-		llist_del(&asp->siblings);
-
-	/* unlink from all ASs we are part of */
-	llist_for_each_entry(as, &asp->inst->as_list, list) {
-		unsigned int i;
-		for (i = 0; i < ARRAY_SIZE(as->cfg.asps); i++) {
-			if (as->cfg.asps[i] == asp) {
-				as->cfg.asps[i] = NULL;
-			}
-		}
-	}
-	/* unlink from ss7_instance */
-	asp->inst = NULL;
-	llist_del(&asp->list);
-	rate_ctr_group_free(asp->ctrg);
-	/* release memory */
-	talloc_free(asp);
-}
-
-static int xua_cli_read_cb(struct osmo_stream_cli *conn);
-static int ipa_cli_read_cb(struct osmo_stream_cli *conn);
-static int xua_cli_connect_cb(struct osmo_stream_cli *cli);
-
-int osmo_ss7_asp_restart(struct osmo_ss7_asp *asp)
-{
-	int rc;
-	char bufloc[512], bufrem[512];
-
-	OSMO_ASSERT(ss7_initialized);
-	osmo_ss7_asp_peer_snprintf(bufloc, sizeof(bufloc), &asp->cfg.local);
-	osmo_ss7_asp_peer_snprintf(bufrem, sizeof(bufrem), &asp->cfg.remote);
-	LOGPASP(asp, DLSS7, LOGL_INFO, "Restarting ASP %s, r=%s<->l=%s\n",
-	       asp->cfg.name, bufrem, bufloc);
-
-	if (!asp->cfg.is_server) {
-		/* We are in client mode now */
-		if (asp->server) {
-			/* if we previously were in server mode,
-			 * destroy it */
-			osmo_stream_srv_destroy(asp->server);
-			asp->server = NULL;
-		}
-		if (!asp->client)
-			asp->client = osmo_stream_cli_create(asp);
-		if (!asp->client) {
-			LOGPASP(asp, DLSS7, LOGL_ERROR, "Unable to create stream"
-				" client for ASP %s\n", asp->cfg.name);
-			return -1;
-		}
-		osmo_stream_cli_set_name(asp->client, asp->cfg.name);
-		osmo_stream_cli_set_nodelay(asp->client, true);
-		osmo_stream_cli_set_addrs(asp->client, (const char**)asp->cfg.remote.host, asp->cfg.remote.host_cnt);
-		osmo_stream_cli_set_port(asp->client, asp->cfg.remote.port);
-		osmo_stream_cli_set_local_addrs(asp->client, (const char**)asp->cfg.local.host, asp->cfg.local.host_cnt);
-		osmo_stream_cli_set_local_port(asp->client, asp->cfg.local.port);
-		osmo_stream_cli_set_proto(asp->client, asp_proto_to_ip_proto(asp->cfg.proto));
-		osmo_stream_cli_set_reconnect_timeout(asp->client, 5);
-		osmo_stream_cli_set_connect_cb(asp->client, xua_cli_connect_cb);
-		if (asp->cfg.proto == OSMO_SS7_ASP_PROT_IPA)
-			osmo_stream_cli_set_read_cb(asp->client, ipa_cli_read_cb);
-		else
-			osmo_stream_cli_set_read_cb(asp->client, xua_cli_read_cb);
-		osmo_stream_cli_set_data(asp->client, asp);
-		rc = osmo_stream_cli_open(asp->client);
-		if (rc < 0) {
-			LOGPASP(asp, DLSS7, LOGL_ERROR, "Unable to open stream"
-				" client for ASP %s, %s ==> %s\n", asp->cfg.name, bufloc, bufrem);
-			/* we don't return error in here because osmo_stream_cli_open()
-			   will continue to retry (due to timeout being explicitly set with
-			   osmo_stream_cli_set_reconnect_timeout() above) to connect so the error is transient */
-		}
-	} else {
-		/* We are in server mode now */
-		if (asp->client) {
-			/* if we previously were in client mode,
-			 * destroy it */
-			osmo_stream_cli_destroy(asp->client);
-			asp->client = NULL;
-		}
-		/* FIXME: ensure we have a SCTP server */
-		LOGPASP(asp, DLSS7, LOGL_NOTICE, "ASP Restart for server "
-			"not implemented yet!\n");
-	}
-
-	/* (re)start the ASP FSM */
-	if (asp->fi)
-		osmo_fsm_inst_term(asp->fi, OSMO_FSM_TERM_REQUEST, NULL);
-	asp->fi = xua_asp_fsm_start(asp, asp->cfg.role, LOGL_DEBUG);
-
-	return 0;
-}
-
-bool osmo_ss7_asp_active(const struct osmo_ss7_asp *asp)
-{
-	if (!asp->fi)
-		return false;
-	return asp->fi->state == XUA_ASP_S_ACTIVE;
-}
-
-/***********************************************************************
- * libosmo-netif integration for SCTP stream server/client
- ***********************************************************************/
-
-static int get_logevel_by_sn_type(int sn_type)
-{
-	switch (sn_type) {
-	case SCTP_ADAPTATION_INDICATION:
-	case SCTP_PEER_ADDR_CHANGE:
-#ifdef SCTP_AUTHENTICATION_INDICATION
-	case SCTP_AUTHENTICATION_INDICATION:
-#endif
-#ifdef SCTP_SENDER_DRY_EVENT
-	case SCTP_SENDER_DRY_EVENT:
-#endif
-		return LOGL_INFO;
-	case SCTP_ASSOC_CHANGE:
-		return LOGL_NOTICE;
-	case SCTP_SHUTDOWN_EVENT:
-	case SCTP_PARTIAL_DELIVERY_EVENT:
-		return LOGL_NOTICE;
-	case SCTP_SEND_FAILED:
-	case SCTP_REMOTE_ERROR:
-		return LOGL_ERROR;
-	default:
-		return LOGL_NOTICE;
-	}
-}
-
-static void log_sctp_notification(struct osmo_ss7_asp *asp, const char *pfx,
-				  union sctp_notification *notif)
-{
-	int log_level;
-
-	LOGPASP(asp, DLSS7, LOGL_INFO, "%s SCTP NOTIFICATION %u flags=0x%0x\n",
-		pfx, notif->sn_header.sn_type,
-		notif->sn_header.sn_flags);
-
-	log_level = get_logevel_by_sn_type(notif->sn_header.sn_type);
-
-	switch (notif->sn_header.sn_type) {
-	case SCTP_ASSOC_CHANGE:
-		LOGPASP(asp, DLSS7, log_level, "%s SCTP_ASSOC_CHANGE: %s\n",
-			pfx, osmo_sctp_assoc_chg_str(notif->sn_assoc_change.sac_state));
-		break;
-	case SCTP_PEER_ADDR_CHANGE:
-		{
-		char addr_str[INET6_ADDRSTRLEN + 10];
-		struct sockaddr_storage sa = notif->sn_paddr_change.spc_aaddr;
-		osmo_sockaddr_to_str_buf(addr_str, sizeof(addr_str), (const struct osmo_sockaddr *)&sa);
-		LOGPASP(asp, DLSS7, log_level, "%s SCTP_PEER_ADDR_CHANGE: %s %s err=%s\n",
-			pfx, osmo_sctp_paddr_chg_str(notif->sn_paddr_change.spc_state), addr_str,
-			(notif->sn_paddr_change.spc_state == SCTP_ADDR_UNREACHABLE) ?
-			osmo_sctp_sn_error_str(notif->sn_paddr_change.spc_error) : "None");
-		}
-		break;
-	default:
-		LOGPASP(asp, DLSS7, log_level, "%s %s\n",
-			pfx, osmo_sctp_sn_type_str(notif->sn_header.sn_type));
-		break;
-	}
-}
-
-/* netif code tells us we can read something from the socket */
-static int ipa_srv_conn_cb(struct osmo_stream_srv *conn)
-{
-	struct osmo_fd *ofd = osmo_stream_srv_get_ofd(conn);
-	struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(conn);
-	struct msgb *msg = NULL;
-	int rc;
-
-	/* read IPA message from socket and process it */
-	rc = ipa_msg_recv_buffered(ofd->fd, &msg, &asp->pending_msg);
-	LOGPASP(asp, DLSS7, LOGL_DEBUG, "%s(): ipa_msg_recv_buffered() returned %d\n",
-		__func__, rc);
-	if (rc <= 0) {
-		if (rc == -EAGAIN) {
-			/* more data needed */
-			return 0;
-		}
-		osmo_stream_srv_destroy(conn);
-		return rc;
-	}
-	if (osmo_ipa_process_msg(msg) < 0) {
-		LOGPASP(asp, DLSS7, LOGL_ERROR, "Bad IPA message\n");
-		osmo_stream_srv_destroy(conn);
-		msgb_free(msg);
-		return -1;
-	}
-	msg->dst = asp;
-
-	return ipa_rx_msg(asp, msg, ofd->fd & 0xf);
-}
-
-/* netif code tells us we can read something from the socket */
-static int xua_srv_conn_cb(struct osmo_stream_srv *conn)
-{
-	struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(conn);
-	struct msgb *msg = m3ua_msgb_alloc("xUA Server Rx");
-	unsigned int ppid;
-	int flags;
-	int rc;
-
-	if (!msg)
-		return -ENOMEM;
-
-	/* read xUA message from socket and process it */
-	rc = osmo_stream_srv_recv(conn, msg);
-	flags = msgb_sctp_msg_flags(msg);
-
-	LOGPASP(asp, DLSS7, LOGL_DEBUG, "%s(): sctp_recvmsg() returned %d (flags=0x%x)\n",
-		__func__, rc, flags);
-
-	if (flags & OSMO_STREAM_SCTP_MSG_FLAGS_NOTIFICATION) {
-		union sctp_notification *notif = (union sctp_notification *) msgb_data(msg);
-		log_sctp_notification(asp, "xUA CLNT", notif);
-		asp_handle_sctp_notif_monitor_primary_address(asp, notif);
-
-		switch (notif->sn_header.sn_type) {
-		case SCTP_ASSOC_CHANGE:
-			if (notif->sn_assoc_change.sac_state == SCTP_RESTART)
-				xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_RESTART,
-							     PRIM_OP_INDICATION);
-		default:
-			break;
-		}
-
-		if (rc == 0) {
-			osmo_stream_srv_destroy(conn);
-			rc = -EBADF;
-		} else {
-			rc = 0;
-		}
-		goto out;
-	}
-	if (rc < 0) {
-		osmo_stream_srv_destroy(conn);
-		rc = -EBADF;
-		goto out;
-	} else if (rc == 0) {
-		osmo_stream_srv_destroy(conn);
-		rc = -EBADF;
-		goto out;
-	}
-
-	ppid = msgb_sctp_ppid(msg);
-	msg->dst = asp;
-	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_RX_TOTAL);
-
-	if (ppid == SUA_PPID && asp->cfg.proto == OSMO_SS7_ASP_PROT_SUA)
-		rc = sua_rx_msg(asp, msg);
-	else if (ppid == M3UA_PPID && asp->cfg.proto == OSMO_SS7_ASP_PROT_M3UA)
-		rc = m3ua_rx_msg(asp, msg);
-	else
-		rc = ss7_asp_rx_unknown(asp, ppid, msg);
-
-out:
-	msgb_free(msg);
-	return rc;
-}
-
-/* client has established SCTP connection to server */
-static int xua_cli_connect_cb(struct osmo_stream_cli *cli)
-{
-	struct osmo_fd *ofd = osmo_stream_cli_get_ofd(cli);
-	struct osmo_ss7_asp *asp = osmo_stream_cli_get_data(cli);
-	int rc = 0;
-
-	/* update the socket name */
-	talloc_free(asp->sock_name);
-	asp->sock_name = osmo_sock_get_name(asp, ofd->fd);
-
-	LOGPASP(asp, DLSS7, LOGL_INFO, "Client connected %s\n", asp->sock_name);
-
-	/* Now that we have the conn in place, the local/remote addresses are
-	 * fed and the local port is known for sure. Apply SCTP Primary addresses
-	 * if needed:
-	 */
-	if (asp->cfg.proto != OSMO_SS7_ASP_PROT_IPA) {
-		rc = asp_apply_peer_primary_address(asp);
-		rc = asp_apply_primary_address(asp);
-	}
-
-	if (asp->lm && asp->lm->prim_cb) {
-		/* Notify layer manager that a connection has been
-		 * established */
-		xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_ESTABLISH, PRIM_OP_INDICATION);
-	} else {
-		/* directly as the ASP FSM to start by sending an ASP-UP ... */
-		osmo_fsm_inst_dispatch(asp->fi, XUA_ASP_E_M_ASP_UP_REQ, NULL);
-	}
-
-	return rc;
-}
-
-static void xua_cli_close(struct osmo_stream_cli *cli)
-{
-	struct osmo_ss7_asp *asp = osmo_stream_cli_get_data(cli);
-
-	osmo_stream_cli_close(cli);
-	osmo_fsm_inst_dispatch(asp->fi, XUA_ASP_E_SCTP_COMM_DOWN_IND, asp);
-	/* send M-SCTP_RELEASE.ind to XUA Layer Manager */
-	xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_RELEASE, PRIM_OP_INDICATION);
-}
-
-static void xua_cli_close_and_reconnect(struct osmo_stream_cli *cli)
-{
-	xua_cli_close(cli);
-	osmo_stream_cli_reconnect(cli);
-}
-
-/* read call-back for IPA/SCCPlite socket */
-static int ipa_cli_read_cb(struct osmo_stream_cli *conn)
-{
-	struct osmo_fd *ofd = osmo_stream_cli_get_ofd(conn);
-	struct osmo_ss7_asp *asp = osmo_stream_cli_get_data(conn);
-	struct msgb *msg = NULL;
-	int rc;
-
-	/* read IPA message from socket and process it */
-	rc = ipa_msg_recv_buffered(ofd->fd, &msg, &asp->pending_msg);
-	LOGPASP(asp, DLSS7, LOGL_DEBUG, "%s(): ipa_msg_recv_buffered() returned %d\n",
-		__func__, rc);
-	if (rc <= 0) {
-		if (rc == -EAGAIN) {
-			/* more data needed */
-			return 0;
-		}
-		xua_cli_close_and_reconnect(conn);
-		return rc;
-	}
-	if (osmo_ipa_process_msg(msg) < 0) {
-		LOGPASP(asp, DLSS7, LOGL_ERROR, "Bad IPA message\n");
-		xua_cli_close_and_reconnect(conn);
-		msgb_free(msg);
-		return -1;
-	}
-	msg->dst = asp;
-	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_RX_TOTAL);
-	return ipa_rx_msg(asp, msg, ofd->fd & 0xf);
-}
-
-static int xua_cli_read_cb(struct osmo_stream_cli *conn)
-{
-	struct osmo_ss7_asp *asp = osmo_stream_cli_get_data(conn);
-	struct msgb *msg = m3ua_msgb_alloc("xUA Client Rx");
-	unsigned int ppid;
-	int flags;
-	int rc;
-
-	if (!msg)
-		return -ENOMEM;
-
-	/* read xUA message from socket and process it */
-	rc = osmo_stream_cli_recv(conn, msg);
-	flags = msgb_sctp_msg_flags(msg);
-
-	LOGPASP(asp, DLSS7, LOGL_DEBUG, "%s(): sctp_recvmsg() returned %d (flags=0x%x)\n",
-		__func__, rc, flags);
-
-	if (flags & OSMO_STREAM_SCTP_MSG_FLAGS_NOTIFICATION) {
-		union sctp_notification *notif = (union sctp_notification *) msgb_data(msg);
-		log_sctp_notification(asp, "xUA CLNT", notif);
-		asp_handle_sctp_notif_monitor_primary_address(asp, notif);
-
-		switch (notif->sn_header.sn_type) {
-		case SCTP_ASSOC_CHANGE:
-			if (notif->sn_assoc_change.sac_state == SCTP_RESTART)
-				xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_RESTART,
-							     PRIM_OP_INDICATION);
-		default:
-			break;
-		}
-
-		if (rc == 0)
-			xua_cli_close_and_reconnect(conn);
-		rc = 0;
-		goto out;
-	}
-	if (rc < 0) {
-		xua_cli_close_and_reconnect(conn);
-		goto out;
-	} else if (rc == 0) {
-		xua_cli_close_and_reconnect(conn);
-		goto out;
-	}
-
-	ppid = msgb_sctp_ppid(msg);
-	msg->dst = asp;
-	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_RX_TOTAL);
-
-	if (ppid == SUA_PPID && asp->cfg.proto == OSMO_SS7_ASP_PROT_SUA)
-		rc = sua_rx_msg(asp, msg);
-	else if (ppid == M3UA_PPID && asp->cfg.proto == OSMO_SS7_ASP_PROT_M3UA)
-		rc = m3ua_rx_msg(asp, msg);
-	else
-		rc = ss7_asp_rx_unknown(asp, ppid, msg);
-
-out:
-	msgb_free(msg);
-	return rc;
-}
-
-static int xua_srv_conn_closed_cb(struct osmo_stream_srv *srv)
-{
-	struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(srv);
-
-	LOGP(DLSS7, LOGL_INFO, "%s: connection closed\n", asp ? asp->cfg.name : "?");
-
-	if (!asp)
-		return 0;
-
-	/* notify ASP FSM and everyone else */
-	osmo_fsm_inst_dispatch(asp->fi, XUA_ASP_E_SCTP_COMM_DOWN_IND, NULL);
-
-	/* delete any RKM-dynamically allocated ASs for this ASP */
-	xua_rkm_cleanup_dyn_as_for_asp(asp);
-
-	/* send M-SCTP_RELEASE.ind to Layer Manager */
-	xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_RELEASE, PRIM_OP_INDICATION);
-
-	asp->server = NULL;
-
-	/* if we were dynamically allocated at accept_cb() time, let's
-	 * self-destruct now.  A new connection will re-create the ASP. */
-	if (asp->dyn_allocated) {
-		/* avoid re-entrance via osmo_stream_srv_destroy() which
-		 * called us */
-		osmo_ss7_asp_destroy(asp);
-	}
-
-	return 0;
-}
-
-
-/* server has accept()ed a new SCTP association, let's find the ASP for
- * it (if any) */
-static int xua_accept_cb(struct osmo_stream_srv_link *link, int fd)
-{
-	struct osmo_xua_server *oxs = osmo_stream_srv_link_get_data(link);
-	struct osmo_stream_srv *srv;
-	struct osmo_ss7_asp *asp;
-	char *sock_name = osmo_sock_get_name(link, fd);
-	const char *proto_name = get_value_string(osmo_ss7_asp_protocol_vals, oxs->cfg.proto);
-	int rc = 0;
-
-	LOGP(DLSS7, LOGL_INFO, "%s: New %s connection accepted\n", sock_name, proto_name);
-
-	if (oxs->cfg.proto == OSMO_SS7_ASP_PROT_IPA) {
-		srv = osmo_stream_srv_create(oxs, link, fd,
-					     ipa_srv_conn_cb,
-					     xua_srv_conn_closed_cb, NULL);
-	} else {
-		srv = osmo_stream_srv_create(oxs, link, fd,
-					     xua_srv_conn_cb,
-					     xua_srv_conn_closed_cb, NULL);
-	}
-	if (!srv) {
-		LOGP(DLSS7, LOGL_ERROR, "%s: Unable to create stream server "
-		     "for connection\n", sock_name);
-		close(fd);
-		talloc_free(sock_name);
-		return -1;
-	}
-
-	asp = osmo_ss7_asp_find_by_socket_addr(fd);
-	if (asp) {
-		LOGP(DLSS7, LOGL_INFO, "%s: matched connection to ASP %s\n",
-			sock_name, asp->cfg.name);
-		/* we need to check if we already have a socket associated, and close it.  Otherwise it might
-		 * happen that both the listen-fd for this accept() and the old socket are marked 'readable'
-		 * during the same scheduling interval, and we're processing them in the "wrong" order, i.e.
-		 * we first see the accept of the new fd before we see the close on the old fd */
-		if (asp->server) {
-			LOGPASP(asp, DLSS7, LOGL_FATAL, "accept of new connection from %s before old was closed "
-				"-> close old one\n", sock_name);
-			osmo_stream_srv_set_data(asp->server, NULL);
-			osmo_stream_srv_destroy(asp->server);
-			asp->server = NULL;
-		}
-	} else {
-		if (!oxs->cfg.accept_dyn_reg) {
-			LOGP(DLSS7, LOGL_NOTICE, "%s: %s connection without matching "
-			     "ASP definition and no dynamic registration enabled, terminating\n",
-			     sock_name, proto_name);
-		} else {
-			char namebuf[32];
-			static uint32_t dyn_asp_num = 0;
-			snprintf(namebuf, sizeof(namebuf), "asp-dyn-%u", dyn_asp_num++);
-			asp = osmo_ss7_asp_find_or_create(oxs->inst, namebuf, 0, 0,
-							  oxs->cfg.proto);
-			if (asp) {
-				char hostbuf[INET6_ADDRSTRLEN];
-				const char *hostbuf_ptr = &hostbuf[0];
-				char portbuf[16];
-
-				osmo_sock_get_ip_and_port(fd, hostbuf, sizeof(hostbuf), portbuf, sizeof(portbuf), false);
-				LOGP(DLSS7, LOGL_INFO, "%s: created dynamic ASP %s\n",
-					sock_name, asp->cfg.name);
-				asp->cfg.is_server = true;
-				asp->cfg.role = OSMO_SS7_ASP_ROLE_SG;
-				asp->cfg.local.port = oxs->cfg.local.port;
-				asp->cfg.remote.port = atoi(portbuf);
-				asp->dyn_allocated = true;
-				asp->server = srv;
-				osmo_ss7_asp_peer_set_hosts(&asp->cfg.local, asp,
-							    (const char* const*)oxs->cfg.local.host,
-							    oxs->cfg.local.host_cnt);
-				osmo_ss7_asp_peer_set_hosts(&asp->cfg.remote, asp,
-							    &hostbuf_ptr, 1);
-				osmo_ss7_asp_restart(asp);
-			}
-		}
-		if (!asp) {
-			osmo_stream_srv_destroy(srv);
-			talloc_free(sock_name);
-			return -1;
-		}
-		llist_add_tail(&asp->siblings, &oxs->asp_list);
-	}
-
-	/* update the ASP reference back to the server over which the
-	 * connection came in */
-	asp->server = srv;
-	asp->xua_server = oxs;
-
-	/* update the ASP socket name */
-	talloc_free(asp->sock_name);
-	asp->sock_name = talloc_reparent(link, asp, sock_name);
-	osmo_stream_srv_set_name(asp->server, asp->cfg.name);
-	/* make sure the conn_cb() is called with the asp as private
-	 * data */
-	osmo_stream_srv_set_data(srv, asp);
-
-	if (oxs->cfg.proto != OSMO_SS7_ASP_PROT_IPA) {
-		rc = asp_apply_peer_primary_address(asp);
-		rc = asp_apply_primary_address(asp);
-	}
-
-	/* send M-SCTP_ESTABLISH.ind to Layer Manager */
-	osmo_fsm_inst_dispatch(asp->fi, XUA_ASP_E_SCTP_EST_IND, 0);
-	xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_ESTABLISH, PRIM_OP_INDICATION);
-
-	return rc;
-}
-
-/*! \brief send a fully encoded msgb via a given ASP
- *  \param[in] asp Application Server Process through which to send
- *  \param[in] msg message buffer to transmit. Ownership transferred.
- *  \returns 0 on success; negative in case of error */
-int osmo_ss7_asp_send(struct osmo_ss7_asp *asp, struct msgb *msg)
-{
-	OSMO_ASSERT(ss7_initialized);
-
-	switch (asp->cfg.proto) {
-	case OSMO_SS7_ASP_PROT_SUA:
-		msgb_sctp_ppid(msg) = SUA_PPID;
-		break;
-	case OSMO_SS7_ASP_PROT_M3UA:
-		msgb_sctp_ppid(msg) = M3UA_PPID;
-		break;
-	case OSMO_SS7_ASP_PROT_IPA:
-		break;
-	default:
-		OSMO_ASSERT(0);
-	}
-
-	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_TX_TOTAL);
-
-	if (asp->cfg.is_server) {
-		if (!asp->server) {
-			LOGPASP(asp, DLSS7, LOGL_ERROR, "Cannot transmit, no asp->server\n");
-			/* FIXME: what to do here? delete the route? send DUNA? */
-			msgb_free(msg);
-			return -EIO;
-		}
-		osmo_stream_srv_send(asp->server, msg);
-	} else {
-		if (!asp->client) {
-			LOGPASP(asp, DLSS7, LOGL_ERROR, "Cannot transmit, no asp->client\n");
-			/* FIXME: what to do here? delete the route? send DUNA? */
-			msgb_free(msg);
-			return -EIO;
-		}
-		if (!osmo_stream_cli_is_connected(asp->client)) {
-			LOGPASP(asp, DLSS7, LOGL_ERROR, "Cannot transmit, asp->client not connected\n");
-			msgb_free(msg);
-			return -EIO;
-		}
-		osmo_stream_cli_send(asp->client, msg);
-	}
-
-	return 0;
-}
-
-void osmo_ss7_asp_disconnect(struct osmo_ss7_asp *asp)
-{
-	if (asp->server)
-		osmo_stream_srv_destroy(asp->server);
-		/* the close_cb() will handle the remaining cleanup here */
-	else if (asp->client)
-		xua_cli_close_and_reconnect(asp->client);
-}
-
-/***********************************************************************
- * SS7 xUA Server
- ***********************************************************************/
-
 struct osmo_xua_server *
 osmo_ss7_xua_server_find(struct osmo_ss7_instance *inst, enum osmo_ss7_asp_protocol proto,
    		 uint16_t local_port)
@@ -2477,136 +1222,6 @@
    return NULL;
 }
-/*! \brief create a new xUA server configured with given ip/port
- *  \param[in] ctx talloc allocation context
- *  \param[in] proto protocol (xUA variant) to use
- *  \param[in] local_port local SCTP port to bind/listen to
- *  \param[in] local_host local IP address to bind/listen to (optional)
- *  \returns callee-allocated \ref osmo_xua_server in case of success
- */
-struct osmo_xua_server *
-osmo_ss7_xua_server_create(struct osmo_ss7_instance *inst, enum osmo_ss7_asp_protocol proto,
-			   uint16_t local_port, const char *local_host)
-{
-	struct osmo_xua_server *oxs = talloc_zero(inst, struct osmo_xua_server);
-
-	OSMO_ASSERT(ss7_initialized);
-	if (!oxs)
-		return NULL;
-
-	LOGP(DLSS7, LOGL_INFO, "Creating %s Server %s:%u\n",
-		get_value_string(osmo_ss7_asp_protocol_vals, proto), local_host, local_port);
-
-	INIT_LLIST_HEAD(&oxs->asp_list);
-
-	oxs->cfg.proto = proto;
-	oxs->cfg.local.port = local_port;
-
-	oxs->server = osmo_stream_srv_link_create(oxs);
-	osmo_stream_srv_link_set_name(oxs->server, osmo_ss7_asp_protocol_name(proto));
-	osmo_stream_srv_link_set_data(oxs->server, oxs);
-	osmo_stream_srv_link_set_accept_cb(oxs->server, xua_accept_cb);
-
-	osmo_stream_srv_link_set_nodelay(oxs->server, true);
-	osmo_stream_srv_link_set_port(oxs->server, oxs->cfg.local.port);
-	osmo_stream_srv_link_set_proto(oxs->server, asp_proto_to_ip_proto(proto));
-
-	osmo_ss7_xua_server_set_local_host(oxs, local_host);
-
-	LOGP(DLSS7, LOGL_INFO, "Created %s server on %s:%" PRIu16 "\n",
-		get_value_string(osmo_ss7_asp_protocol_vals, proto), local_host, local_port);
-
-	oxs->inst = inst;
-	llist_add_tail(&oxs->list, &inst->xua_servers);
-
-	/* The SUA code internally needs SCCP to work */
-	if (proto == OSMO_SS7_ASP_PROT_SUA)
-		osmo_ss7_ensure_sccp(inst);
-
-	return oxs;
-}
-
-/*! \brief Set the xUA server to bind/listen to the currently configured ip/port
- *  \param[in] xs xUA server to operate
- *  \returns 0 on success, negative value on error.
- */
-int
-osmo_ss7_xua_server_bind(struct osmo_xua_server *xs)
-{
-	char buf[512];
-	int rc;
-	const char *proto = get_value_string(osmo_ss7_asp_protocol_vals, xs->cfg.proto);
-
-	rc = osmo_ss7_asp_peer_snprintf(buf, sizeof(buf), &xs->cfg.local);
-	if (rc < 0) {
-		LOGP(DLSS7, LOGL_INFO, "Failed parsing %s Server osmo_ss7_asp_peer\n", proto);
-	} else {
-		LOGP(DLSS7, LOGL_INFO, "(Re)binding %s Server to %s\n",
-		     proto, buf);
-	}
-	return osmo_stream_srv_link_open(xs->server);
-}
-
-int
-osmo_ss7_xua_server_set_local_host(struct osmo_xua_server *xs, const char *local_host)
-{
-	return osmo_ss7_xua_server_set_local_hosts(xs, &local_host, 1);
-}
-
-int
-osmo_ss7_xua_server_set_local_hosts(struct osmo_xua_server *xs, const char **local_hosts, size_t local_host_cnt)
-{
-	int rc;
-	OSMO_ASSERT(ss7_initialized);
-
-	rc = osmo_ss7_asp_peer_set_hosts(&xs->cfg.local, xs, local_hosts, local_host_cnt);
-	if (rc < 0)
-		return rc;
-	return osmo_stream_srv_link_set_addrs(xs->server, (const char **)xs->cfg.local.host, xs->cfg.local.host_cnt);
-}
-
-int
-osmo_ss7_xua_server_add_local_host(struct osmo_xua_server *xs, const char *local_host)
-{
-	int rc;
-
-	rc = osmo_ss7_asp_peer_add_host(&xs->cfg.local, xs, local_host);
-	if (rc < 0)
-		return rc;
-	return osmo_stream_srv_link_set_addrs(xs->server, (const char **)xs->cfg.local.host, xs->cfg.local.host_cnt);
-}
-
-bool ss7_xua_server_set_default_local_hosts(struct osmo_xua_server *oxs)
-{
-	/* If no local addr was set, or erased after _create(): */
-	if (!oxs->cfg.local.host_cnt) {
-		/* "::" Covers both IPv4 and IPv6 */
-		if (ipv6_sctp_supported("::", true))
-			osmo_ss7_xua_server_set_local_host(oxs, "::");
-		else
-			osmo_ss7_xua_server_set_local_host(oxs, "0.0.0.0");
-		return true;
-	}
-	return false;
-}
-
-void osmo_ss7_xua_server_destroy(struct osmo_xua_server *xs)
-{
-	struct osmo_ss7_asp *asp, *asp2;
-
-	if (xs->server) {
-		osmo_stream_srv_link_close(xs->server);
-		osmo_stream_srv_link_destroy(xs->server);
-	}
-	/* iterate and close all connections established in relation
-	 * with this server */
-	llist_for_each_entry_safe(asp, asp2, &xs->asp_list, siblings)
-		osmo_ss7_asp_destroy(asp);
-
-	llist_del(&xs->list);
-	talloc_free(xs);
-}
-
 bool osmo_ss7_pc_is_local(struct osmo_ss7_instance *inst, uint32_t pc)
 {
    OSMO_ASSERT(ss7_initialized);
@@ -2694,62 +1309,3 @@
    }
    return false;
 }
-
-static osmo_ss7_asp_rx_unknown_cb *g_osmo_ss7_asp_rx_unknown_cb;
-
-int ss7_asp_rx_unknown(struct osmo_ss7_asp *asp, int ppid_mux, struct msgb *msg)
-{
-	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_RX_UNKNOWN);
-
-	if (g_osmo_ss7_asp_rx_unknown_cb)
-		return (*g_osmo_ss7_asp_rx_unknown_cb)(asp, ppid_mux, msg);
-
-	switch(asp->cfg.proto) {
-	case OSMO_SS7_ASP_PROT_IPA:
-		LOGPASP(asp, DLSS7, LOGL_NOTICE, "Rx IPA for unknown Stream ID 0x%02x: %s\n",
-			ppid_mux, msgb_hexdump(msg));
-		break;
-	default:
-		LOGPASP(asp, DLSS7, LOGL_NOTICE, "Rx SCTP chunk for unknown PPID %u: %s\n",
-			ppid_mux, msgb_hexdump(msg));
-		break;
-	}
-	return 0;
-}
-
-/*! Get the logging subsystem for a given ASP. Used by generic code. */
-int osmo_ss7_asp_get_log_subsys(const struct osmo_ss7_asp *asp)
-{
-	switch (asp->cfg.proto) {
-	case OSMO_SS7_ASP_PROT_M3UA:
-		return DLM3UA;
-	case OSMO_SS7_ASP_PROT_SUA:
-		return DLSUA;
-	default:
-		return DLSS7;
-	}
-}
-
-/*! \brief Get the name of a given ASP
- *  \param[in] asp The ASP for which the name is requested
- *  \returns The name of the ASP, or NULL if not set
- */
-const char *osmo_ss7_asp_get_name(const struct osmo_ss7_asp *asp)
-{
-	return asp->cfg.name;
-}
-
-/*! \brief Get the proto of a given ASP
- *  \param[in] asp The ASP for which the proto is requested
- *  \returns The proto of the ASP
- */
-enum osmo_ss7_asp_protocol osmo_ss7_asp_get_proto(const struct osmo_ss7_asp *asp)
-{
-	return asp->cfg.proto;
-}
-
-/*! Register a call-back function for unknown SCTP PPID / IPA Stream ID */
-void osmo_ss7_register_rx_unknown_cb(osmo_ss7_asp_rx_unknown_cb *cb)
-{
-	g_osmo_ss7_asp_rx_unknown_cb = cb;
-}
diff --git a/src/osmo_ss7_asp.c b/src/osmo_ss7_asp.c
new file mode 100644
index 0000000..c282730
--- /dev/null
+++ b/src/osmo_ss7_asp.c
@@ -0,0 +1,1246 @@
+/* Core SS7 ASP Handling */
+
+/* (C) 2015-2017 by Harald Welte laforge@gnumonks.org
+ * (C) 2023 by sysmocom s.f.m.c. GmbH info@sysmocom.de
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/.
+ *
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/sctp.h>
+
+#include <osmocom/sigtran/osmo_ss7.h>
+#include <osmocom/sigtran/mtp_sap.h>
+#include <osmocom/sigtran/protocol/mtp.h>
+#include <osmocom/sigtran/protocol/sua.h>
+#include <osmocom/sigtran/protocol/m3ua.h>
+
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/sockaddr_str.h>
+
+#include <osmocom/netif/stream.h>
+#include <osmocom/netif/ipa.h>
+#include <osmocom/netif/sctp.h>
+
+#include "sccp_internal.h"
+#include "xua_internal.h"
+#include "ss7_internal.h"
+#include "xua_asp_fsm.h"
+#include "xua_as_fsm.h"
+
+static int _setsockopt_peer_primary_addr(int fd, const struct osmo_sockaddr *saddr)
+{
+	int rc;
+
+	struct sctp_setpeerprim so_sctp_setpeerprim = {0};
+
+	/* rfc6458 sec 8: "For the one-to-one style sockets and branched-off one-to-many
+	 * style sockets (see Section 9.2), this association ID parameter is ignored"
+	 */
+
+	/* NOTE: Requires setting:
+	 * - sysctl net.sctp.addip_enable = 1, otherwise EPERM is returned
+	 * - sysctl net.sctp.auth_enable = 1, RFC 5061 4.2.7 "An implementation supporting this
+	 *   extension MUST list the ASCONF,the ASCONF-ACK, and the AUTH chunks in
+	 *   its INIT and INIT-ACK parameters."
+	 */
+
+	so_sctp_setpeerprim.sspp_addr = saddr->u.sas;
+	rc = setsockopt(fd, IPPROTO_SCTP, SCTP_SET_PEER_PRIMARY_ADDR,
+			&so_sctp_setpeerprim, sizeof(so_sctp_setpeerprim));
+	if (rc < 0) {
+		char buf[128];
+		int err = errno;
+		strerror_r(err, (char *)buf, sizeof(buf));
+		LOGP(DLSS7, LOGL_ERROR, "setsockopt(SCTP_SET_PEER_PRIMARY_ADDR, %s) failed: %s%s\n",
+		     osmo_sockaddr_to_str(saddr), buf,
+		     err == EPERM ? " (EPERM: Make sure you have sysctl 'net.sctp.auth_enable' "
+				    "and 'net.sctp.addip_enable' set to 1)" : "");
+	}
+	return rc;
+}
+
+static int _setsockopt_primary_addr(int fd, const struct osmo_sockaddr *saddr)
+{
+	int rc;
+
+	struct sctp_prim so_sctp_prim = {0};
+
+	/* rfc6458 sec 8: "For the one-to-one style sockets and branched-off one-to-many
+	 * style sockets (see Section 9.2), this association ID parameter is ignored"
+	 */
+
+	so_sctp_prim.ssp_addr = saddr->u.sas;
+	rc = setsockopt(fd, IPPROTO_SCTP, SCTP_PRIMARY_ADDR,
+			&so_sctp_prim, sizeof(so_sctp_prim));
+	if (rc < 0) {
+		char buf[128];
+		strerror_r(errno, (char *)buf, sizeof(buf));
+		LOGP(DLSS7, LOGL_ERROR, "setsockopt(SCTP_PRIMARY_ADDR, %s) failed: %s\n",
+		     osmo_sockaddr_to_str(saddr), buf);
+	}
+	return rc;
+}
+
+/***********************************************************************
+ * SS7 Application Server Process
+ ***********************************************************************/
+
+struct value_string osmo_ss7_asp_protocol_vals[] = {
+	{ OSMO_SS7_ASP_PROT_NONE,	"none" },
+	{ OSMO_SS7_ASP_PROT_SUA,	"sua" },
+	{ OSMO_SS7_ASP_PROT_M3UA,	"m3ua" },
+	{ OSMO_SS7_ASP_PROT_IPA,	"ipa" },
+	{ 0, NULL }
+};
+
+const struct value_string osmo_ss7_asp_role_names[] = {
+	{ OSMO_SS7_ASP_ROLE_ASP,	"ASP" },
+	{ OSMO_SS7_ASP_ROLE_SG,		"SG" },
+	{ OSMO_SS7_ASP_ROLE_IPSP,	"IPSP" },
+	{ 0, NULL }
+};
+
+int ss7_asp_proto_to_ip_proto(enum osmo_ss7_asp_protocol proto)
+{
+	switch (proto) {
+	case OSMO_SS7_ASP_PROT_IPA:
+		return IPPROTO_TCP;
+	case OSMO_SS7_ASP_PROT_SUA:
+	case OSMO_SS7_ASP_PROT_M3UA:
+	default:
+		return IPPROTO_SCTP;
+	}
+}
+
+static const uint16_t prot2port[] = {
+	[OSMO_SS7_ASP_PROT_NONE] = 0,
+	[OSMO_SS7_ASP_PROT_SUA] = SUA_PORT,
+	[OSMO_SS7_ASP_PROT_M3UA] = M3UA_PORT,
+	[OSMO_SS7_ASP_PROT_IPA] = 5000,
+};
+
+int osmo_ss7_asp_protocol_port(enum osmo_ss7_asp_protocol prot)
+{
+	if (prot >= ARRAY_SIZE(prot2port))
+		return -EINVAL;
+	else
+		return prot2port[prot];
+}
+
+static const struct rate_ctr_desc ss7_asp_rcd[] = {
+	[SS7_ASP_CTR_PKT_RX_TOTAL] = { "rx:packets:total", "Total number of packets received" },
+	[SS7_ASP_CTR_PKT_RX_UNKNOWN] = { "rx:packets:unknown", "Number of packets received for unknown PPID" },
+	[SS7_ASP_CTR_PKT_TX_TOTAL] = { "tx:packets:total", "Total number of packets transmitted" },
+};
+
+static const struct rate_ctr_group_desc ss7_asp_rcgd = {
+	.group_name_prefix = "sigtran_asp",
+	.group_description = "SIGTRAN Application Server Process",
+	.num_ctr = ARRAY_SIZE(ss7_asp_rcd),
+	.ctr_desc = ss7_asp_rcd,
+};
+static unsigned int g_ss7_asp_rcg_idx;
+
+void osmo_ss7_asp_peer_init(struct osmo_ss7_asp_peer *peer)
+{
+	memset(peer, 0, sizeof(*peer));
+	peer->idx_primary = -1;
+}
+
+int osmo_ss7_asp_peer_snprintf(char *buf, size_t buf_len, struct osmo_ss7_asp_peer *peer)
+{
+	int len = 0, offset = 0, rem = buf_len;
+	int ret, i;
+	char *after;
+	char *primary;
+
+	if (buf_len < 3)
+		return -EINVAL;
+
+	if (peer->host_cnt > 1) {
+		ret = snprintf(buf, rem, "(");
+		if (ret < 0)
+			return ret;
+		OSMO_SNPRINTF_RET(ret, rem, offset, len);
+	}
+	for (i = 0; i < peer->host_cnt; i++) {
+		primary = (peer->idx_primary == i) ? "*" : "";
+		if (peer->host_cnt == 1)
+			after = "";
+		else
+			after = (i == (peer->host_cnt - 1)) ? ")" : "|";
+		ret = snprintf(buf + offset, rem, "%s%s%s", peer->host[i] ? : "0.0.0.0", primary, after);
+		OSMO_SNPRINTF_RET(ret, rem, offset, len);
+	}
+	ret = snprintf(buf + offset, rem, ":%u", peer->port);
+	if (ret < 0)
+		return ret;
+	OSMO_SNPRINTF_RET(ret, rem, offset, len);
+
+	return len;
+}
+
+/*! \brief Set (copy) addresses for a given ASP peer. Previous addresses are freed.
+ *  \param[in] peer Application Server Process peer whose addresses are to be set.
+ *  \param[in] talloc_ctx talloc context used to allocate new addresses.
+ *  \param[in] hosts Array of strings containing IP addresses.
+ *  \param[in] host_cnt Number of strings in hosts
+ *  \param[in] idx_primary Index in "hosts" array marking the SCTP Primary Address, -1 if no explicit Primary Address set
+ *  \returns 0 on success; negative otherwise */
+int osmo_ss7_asp_peer_set_hosts2(struct osmo_ss7_asp_peer *peer, void *talloc_ctx, const char *const*hosts, size_t host_cnt, int idx_primary)
+{
+	int i = 0;
+
+	if (idx_primary >= (int)host_cnt || idx_primary < -1)
+		return -EINVAL;
+
+	if (host_cnt > ARRAY_SIZE(peer->host))
+		return -EINVAL;
+
+	for (; i < host_cnt; i++)
+		osmo_talloc_replace_string(talloc_ctx, &peer->host[i], hosts[i]);
+	for (; i < peer->host_cnt; i++) {
+		talloc_free(peer->host[i]);
+		peer->host[i] = NULL;
+	}
+
+	peer->host_cnt = host_cnt;
+	peer->idx_primary = idx_primary;
+	return 0;
+}
+
+/*! \brief Set (copy) addresses for a given ASP peer. Previous addresses are freed.
+ *  \param[in] peer Application Server Process peer whose addresses are to be set.
+ *  \param[in] talloc_ctx talloc context used to allocate new addresses.
+ *  \param[in] hosts Array of strings containing IP addresses.
+ *  \param[in] host_cnt Number of strings in hosts
+ *  \returns 0 on success; negative otherwise */
+int osmo_ss7_asp_peer_set_hosts(struct osmo_ss7_asp_peer *peer, void *talloc_ctx, const char *const*hosts, size_t host_cnt)
+{
+	return osmo_ss7_asp_peer_set_hosts2(peer, talloc_ctx, hosts, host_cnt, -1);
+}
+
+/* Is string formatted IPv4/v6 addr considered IN(6)ADDR_ANY? */
+static inline bool host_is_ip_anyaddr(const char *host, bool is_v6)
+{
+	/* NULL addr is resolved as 0.0.0.0 (IPv4) by getaddrinfo(), most
+	 * probably for backward-compatibility reasons.
+	 */
+	return is_v6 ? (host && !strcmp(host, "::"))
+		     : (!host || !strcmp(host, "0.0.0.0"));
+}
+
+/*! \brief Append (copy) address to a given ASP peer. Previous addresses are kept.
+ *  \param[in] peer Application Server Process peer the address is appended to.
+ *  \param[in] talloc_ctx talloc context used to allocate new address.
+ *  \param[in] host string containing an IP address.
+ *  \param[in] is_primary_addr whether this IP address is to be added as SCTP Primary Address
+ *  \returns 0 on success; negative otherwise */
+int osmo_ss7_asp_peer_add_host2(struct osmo_ss7_asp_peer *peer, void *talloc_ctx,
+			       const char *host, bool is_primary_addr)
+{
+	int i;
+	bool new_is_v6 = osmo_ip_str_type(host) == AF_INET6;
+	bool new_is_any = host_is_ip_anyaddr(host, new_is_v6);
+	struct osmo_sockaddr_str addr_str;
+
+	if (osmo_sockaddr_str_from_str(&addr_str, host, 0) < 0)
+		return -EINVAL;
+
+	if (new_is_any) {
+		/* Makes no sense to have INET(6)_ANY many times, or INET(6)_ANY
+		 * together with specific addresses, be it of same or different
+		 * IP version: */
+		if (peer->host_cnt != 0)
+			return -EINVAL;
+
+		/* Makes no sense to have INET(6)_ANY as primary: */
+		if (is_primary_addr)
+			return -EINVAL;
+
+		if (peer->host_cnt >= ARRAY_SIZE(peer->host))
+			return -EINVAL;
+		osmo_talloc_replace_string(talloc_ctx, &peer->host[peer->host_cnt], host);
+		peer->host_cnt++;
+		return 0;
+	}
+
+	/* Makes no sense to add specific address to set if INET(6)_ANY
+	 * is already set, be it from same or different IP version: */
+	for (i = 0; i < peer->host_cnt; i++) {
+		bool iter_is_v6 = osmo_ip_str_type(peer->host[i]) == AF_INET6;
+		if (host_is_ip_anyaddr(peer->host[i], iter_is_v6))
+			return -EINVAL;
+	}
+	/* Reached this point, no INET(6)_ANY address is set nor we are adding an INET(6)_ANY address. */
+
+	/* Check if address already exists, and then if primary flags need to be changed: */
+	for (i = 0; i < peer->host_cnt; i++) {
+		struct osmo_sockaddr_str it_addr_str;
+		bool it_is_primary;
+		osmo_sockaddr_str_from_str(&it_addr_str, peer->host[i], 0);
+
+		if (osmo_sockaddr_str_cmp(&addr_str, &it_addr_str) != 0)
+			continue;
+		it_is_primary = (peer->idx_primary == i);
+		if (is_primary_addr == it_is_primary) {
+			/* Nothing to do, return below */
+		} else if (is_primary_addr && !it_is_primary) {
+			/* Mark it as primary: */
+			peer->idx_primary = i;
+		} else { /* if (!is_primary_addr && it_is_primary) { */
+			/* mark it as non-primary: */
+			peer->idx_primary = -1;
+		}
+		return 0;
+	}
+
+	if (peer->host_cnt >= ARRAY_SIZE(peer->host))
+		return -EINVAL;
+
+	osmo_talloc_replace_string(talloc_ctx, &peer->host[peer->host_cnt], host);
+	if (is_primary_addr)
+		peer->idx_primary = peer->host_cnt;
+	peer->host_cnt++;
+	return 0;
+}
+
+/*! \brief Append (copy) address to a given ASP peer. Previous addresses are kept.
+ *  \param[in] peer Application Server Process peer the address is appended to.
+ *  \param[in] talloc_ctx talloc context used to allocate new address.
+ *  \param[in] host string containing an IP address.
+ *  \returns 0 on success; negative otherwise */
+int osmo_ss7_asp_peer_add_host(struct osmo_ss7_asp_peer *peer, void *talloc_ctx,
+			       const char *host)
+{
+	return osmo_ss7_asp_peer_add_host2(peer, talloc_ctx, host, false);
+}
+
+int ss7_asp_apply_peer_primary_address(const struct osmo_ss7_asp *asp)
+{
+	struct osmo_fd *ofd;
+	struct osmo_sockaddr_str addr_str;
+	struct osmo_sockaddr addr;
+	uint16_t local_port;
+	int rc;
+
+	/* No SCTP Peer Primary Address explicitly configured, do nothing. */
+	if (asp->cfg.local.idx_primary == -1)
+		return 0;
+	OSMO_ASSERT(asp->cfg.local.idx_primary < asp->cfg.local.host_cnt);
+
+	if (asp->cfg.is_server)
+		ofd = osmo_stream_srv_get_ofd(asp->server);
+	else
+		ofd = osmo_stream_cli_get_ofd(asp->client);
+
+	if (asp->cfg.local.port == 0) {
+		char port_buf[16];
+		osmo_sock_get_local_ip_port(ofd->fd, port_buf, sizeof(port_buf));
+		local_port = atoi(port_buf);
+	} else {
+		local_port = asp->cfg.local.port;
+	}
+	rc = osmo_sockaddr_str_from_str(&addr_str,
+					asp->cfg.local.host[asp->cfg.local.idx_primary],
+					local_port);
+	if (rc < 0)
+		return rc;
+	rc = osmo_sockaddr_str_to_sockaddr(&addr_str, &addr.u.sas);
+	if (rc < 0)
+		return rc;
+	LOGPASP(asp, DLSS7, LOGL_INFO, "Set Peer's Primary Address %s\n",
+		osmo_sockaddr_to_str(&addr));
+	rc = _setsockopt_peer_primary_addr(ofd->fd, &addr);
+
+	return rc;
+}
+
+int ss7_asp_apply_primary_address(const struct osmo_ss7_asp *asp)
+{
+	struct osmo_fd *ofd;
+	struct osmo_sockaddr_str addr_str;
+	struct osmo_sockaddr addr;
+	int rc;
+
+	/* No SCTP Primary Address explicitly configured, do nothing. */
+	if (asp->cfg.remote.idx_primary == -1)
+		return 0;
+	OSMO_ASSERT(asp->cfg.remote.idx_primary < asp->cfg.remote.host_cnt);
+
+	if (asp->cfg.is_server)
+		ofd = osmo_stream_srv_get_ofd(asp->server);
+	else
+		ofd = osmo_stream_cli_get_ofd(asp->client);
+
+	rc = osmo_sockaddr_str_from_str(&addr_str,
+					asp->cfg.remote.host[asp->cfg.remote.idx_primary],
+					asp->cfg.remote.port);
+	if (rc < 0)
+		return rc;
+	rc = osmo_sockaddr_str_to_sockaddr(&addr_str, &addr.u.sas);
+	if (rc < 0)
+		return rc;
+	LOGPASP(asp, DLSS7, LOGL_INFO, "Set Primary Address %s\n",
+		osmo_sockaddr_to_str(&addr));
+	rc = _setsockopt_primary_addr(ofd->fd, &addr);
+	return rc;
+}
+
+/* Returns whether the address signalled in the SCTP_PEER_ADDR_CHANGE matches
+ * the user-configured Primary Address. */
+static bool sctp_peer_addr_change_ev_addr_matches_our_primary(const struct osmo_ss7_asp *asp,
+							      const union sctp_notification *notif)
+{
+	const char *primary_str;
+	int primary_str_type;
+	struct osmo_sockaddr ev_addr, primary;
+
+	OSMO_ASSERT(asp->cfg.remote.idx_primary >= 0);
+
+	primary_str = asp->cfg.remote.host[asp->cfg.remote.idx_primary];
+	primary_str_type = osmo_ip_str_type(primary_str);
+	memcpy(&ev_addr.u.sas, &notif->sn_paddr_change.spc_aaddr, sizeof(ev_addr.u.sas));
+
+	/* This whole switch is to properly compare addresses (take into account v6mapped IPv4 addresses): */
+	switch (ev_addr.u.sa.sa_family) {
+	case AF_INET:
+		switch (primary_str_type) {
+		case AF_INET:
+			primary = ev_addr; /* Copy AF + port */
+			inet_pton(AF_INET, primary_str, &primary.u.sin.sin_addr);
+			return (osmo_sockaddr_cmp(&primary, &ev_addr) == 0);
+		case AF_INET6:
+			/* for sure not the same */
+			return false;
+		}
+		return false;
+	case AF_INET6:
+		/* "ev_addr" can either be a IPv6 addr or a v6-mapped IPv4
+		 * address. Compare both as IPv6 (or v6-mapped IPv4) addresses. */
+		primary = ev_addr; /* Copy AF + port */
+		inet_pton(AF_INET6, primary_str, &primary.u.sin6.sin6_addr);
+		return (osmo_sockaddr_cmp(&primary, &ev_addr) == 0);
+	default:
+		return false;
+	}
+}
+
+/* Simple SCTP Path-manager tracking/driving the VTY-user-configured primary
+ * address against the kernel when assoc state changes: */
+static void asp_handle_sctp_notif_monitor_primary_address(const struct osmo_ss7_asp *asp,
+							  const union sctp_notification *notif)
+{
+	bool match;
+
+	if (asp->cfg.remote.idx_primary == -1)
+		return;
+	if (notif->sn_header.sn_type != SCTP_PEER_ADDR_CHANGE)
+		return;
+
+	switch (notif->sn_paddr_change.spc_state) {
+	case SCTP_ADDR_AVAILABLE:
+	case SCTP_ADDR_ADDED:
+	case SCTP_ADDR_CONFIRMED:
+		/* If our primary addr became available/added/confirmed, set it */
+		match = sctp_peer_addr_change_ev_addr_matches_our_primary(asp, notif);
+		if (match)
+			ss7_asp_apply_primary_address(asp);
+		break;
+	case SCTP_ADDR_MADE_PRIM:
+		/* If another primary addr was made primary, overwrite it by setting it again */
+		match = sctp_peer_addr_change_ev_addr_matches_our_primary(asp, notif);
+		if (!match)
+			ss7_asp_apply_primary_address(asp);
+	default:
+		break;
+	}
+}
+
+/* Set default values for local and remote peer hosts if they are not yet set.
+ *  \param[in] asp ASP for which to set default hosts.
+ *  \returns true if values where changed, false otherwise.
+ *
+ * If the ASP is already started, osmo_ss7_asp_restart() must be called
+ * afterwards in order to apply the new settings.
+ * This API is internal, hence doesn't appear in osmo_ss7.h
+ */
+bool ss7_asp_set_default_peer_hosts(struct osmo_ss7_asp *asp)
+{
+	bool changed = false;
+	/* If no local addr was set */
+	if (!asp->cfg.local.host_cnt) {
+		bool rem_has_v4 = false, rem_has_v6 = false;
+		int i;
+		for (i = 0; i < asp->cfg.remote.host_cnt; i++) {
+			if (osmo_ip_str_type(asp->cfg.remote.host[i]) == AF_INET6)
+				rem_has_v6 = true;
+			else
+				rem_has_v4 = true;
+		}
+		/* "::" Covers both IPv4 and IPv6, but if only IPv4
+		 * address are set on the remote side, IPv4 on the local
+		 * side must be set too */
+		if (ss7_ipv6_sctp_supported("::", true) && !(rem_has_v4 && !rem_has_v6))
+			osmo_ss7_asp_peer_add_host(&asp->cfg.local, asp, "::");
+		else
+			osmo_ss7_asp_peer_add_host(&asp->cfg.local, asp, "0.0.0.0");
+		changed = true;
+	}
+	/* If no remote addr was set */
+	if (!asp->cfg.remote.host_cnt) {
+		osmo_ss7_asp_peer_add_host(&asp->cfg.remote, asp, "127.0.0.1");
+		if (ss7_ipv6_sctp_supported("::1", false))
+			osmo_ss7_asp_peer_add_host(&asp->cfg.remote, asp, "::1");
+		changed = true;
+	}
+	return changed;
+}
+
+static uint16_t get_in_port(struct sockaddr *sa)
+{
+	switch (sa->sa_family) {
+	case AF_INET:
+		return (((struct sockaddr_in *)sa)->sin_port);
+	case AF_INET6:
+		return (((struct sockaddr_in6 *)sa)->sin6_port);
+	default:
+		return 0;
+	}
+}
+
+/* Converts string representation of v4-mappend-on-v6 IP addr to a pure IPv4 address.
+ * Example: ::ffff:172.18.19.200 => 172.18.19.200
+ */
+static void chop_v4_mapped_on_v6_prefix(char *buf)
+{
+	char *last_colon;
+	size_t len;
+	char *first_dot = strchr(buf, '.');
+
+	if (!first_dot)
+		return; /* Not an IPv4-mappend-on-v6 string representation, nothing to do */
+	last_colon = strrchr(buf, ':');
+	if (!last_colon)
+		return; /* pure IPv4 address, nothing to do */
+
+	len = strlen(last_colon + 1);
+	memmove(buf, last_colon + 1, len);
+	buf[len] = '\0';
+}
+
+/*! \brief Find an ASP definition matching the local+remote IP/PORT of given fd
+ *  \param[in] fd socket descriptor of given socket
+ *  \returns SS7 ASP in case a matching one is found; NULL otherwise */
+struct osmo_ss7_asp *
+ss7_asp_find_by_socket_addr(int fd)
+{
+	struct osmo_ss7_instance *inst;
+	struct sockaddr_storage sa_l, sa_r;
+	socklen_t sa_len_l = sizeof(sa_l);
+	socklen_t sa_len_r = sizeof(sa_r);
+	char hostbuf_l[64], hostbuf_r[64];
+	uint16_t local_port, remote_port;
+	bool loc_is_v6, rem_is_v6;
+	int rc;
+	int i;
+
+	OSMO_ASSERT(ss7_initialized);
+	/* convert local and remote IP to string */
+	rc = getsockname(fd, (struct sockaddr *)&sa_l, &sa_len_l);
+	if (rc < 0)
+		return NULL;
+	rc = getnameinfo((struct sockaddr *)&sa_l, sa_len_l,
+			 hostbuf_l, sizeof(hostbuf_l),
+			 NULL, 0, NI_NUMERICHOST);
+	if (rc < 0)
+		return NULL;
+	local_port = ntohs(get_in_port((struct sockaddr *)&sa_l));
+
+	rc = getpeername(fd, (struct sockaddr *)&sa_r, &sa_len_r);
+	if (rc < 0)
+		return NULL;
+	rc = getnameinfo((struct sockaddr *)&sa_r, sa_len_r,
+			 hostbuf_r, sizeof(hostbuf_r),
+			 NULL, 0, NI_NUMERICHOST);
+	if (rc < 0)
+		return NULL;
+	remote_port = ntohs(get_in_port((struct sockaddr *)&sa_r));
+
+	/* If multi-home is used with both IPv4 and IPv6, then the socket is
+	 * AF_INET6, and then returned IPv4 addresses are actually v6mapped ones.
+	 * We need to convert them to IPv4 before matching.
+	 */
+	chop_v4_mapped_on_v6_prefix(hostbuf_l);
+	chop_v4_mapped_on_v6_prefix(hostbuf_r);
+	loc_is_v6 = osmo_ip_str_type(hostbuf_l) == AF_INET6;
+	rem_is_v6 = osmo_ip_str_type(hostbuf_r) == AF_INET6;
+
+	/* check all instances for any ASP definition matching the
+	 * address combination of local/remote ip/port */
+	llist_for_each_entry(inst, &osmo_ss7_instances, list) {
+		struct osmo_ss7_asp *asp;
+		llist_for_each_entry(asp, &inst->asp_list, list) {
+			if (asp->cfg.local.port != local_port)
+				continue;
+			if (asp->cfg.remote.port && asp->cfg.remote.port != remote_port)
+				continue;
+
+			for (i = 0; i < asp->cfg.local.host_cnt; i++) {
+				bool iter_is_v6 = osmo_ip_str_type(asp->cfg.local.host[i]) == AF_INET6;
+				bool iter_is_anyaddr = host_is_ip_anyaddr(asp->cfg.local.host[i], iter_is_v6);
+				/* "::" (v6) covers "0.0.0.0" (v4), but not otherwise */
+				if (iter_is_v6 != loc_is_v6 &&
+				    !(iter_is_v6 && iter_is_anyaddr))
+					continue;
+				if (iter_is_anyaddr ||
+				    !strcmp(asp->cfg.local.host[i], hostbuf_l))
+					break;
+			}
+			if (i == asp->cfg.local.host_cnt)
+				continue; /* didn't match any local.host */
+
+			/* If no remote host was set, it's probably a server and hence we match any cli src */
+			if (asp->cfg.remote.host_cnt) {
+				for (i = 0; i < asp->cfg.remote.host_cnt; i++) {
+					bool iter_is_v6 = osmo_ip_str_type(asp->cfg.remote.host[i]) == AF_INET6;
+					bool iter_is_anyaddr = host_is_ip_anyaddr(asp->cfg.remote.host[i], iter_is_v6);
+					/* "::" (v6) covers "0.0.0.0" (v4), but not otherwise */
+					if (iter_is_v6 != rem_is_v6 &&
+					    !(iter_is_v6 && iter_is_anyaddr))
+						continue;
+					if (iter_is_anyaddr ||
+					    !strcmp(asp->cfg.remote.host[i], hostbuf_r))
+						break;
+				}
+				if (i == asp->cfg.remote.host_cnt)
+					continue; /* didn't match any remote.host */
+			}
+
+			return asp;
+		}
+	}
+
+	return NULL;
+}
+
+struct osmo_ss7_asp *ss7_asp_alloc(struct osmo_ss7_instance *inst, const char *name,
+				   uint16_t remote_port, uint16_t local_port,
+				   enum osmo_ss7_asp_protocol proto)
+{
+	struct osmo_ss7_asp *asp = talloc_zero(inst, struct osmo_ss7_asp);
+	asp->ctrg = rate_ctr_group_alloc(asp, &ss7_asp_rcgd, g_ss7_asp_rcg_idx++);
+	if (!asp->ctrg) {
+		talloc_free(asp);
+		return NULL;
+	}
+	rate_ctr_group_set_name(asp->ctrg, name);
+	asp->inst = inst;
+	osmo_ss7_asp_peer_init(&asp->cfg.remote);
+	asp->cfg.remote.port = remote_port;
+	osmo_ss7_asp_peer_init(&asp->cfg.local);
+	asp->cfg.local.port = local_port;
+	asp->cfg.proto = proto;
+	asp->cfg.name = talloc_strdup(asp, name);
+
+	asp->cfg.T_defs_lm = talloc_memdup(asp, ss7_asp_lm_timer_defaults,
+					   sizeof(ss7_asp_lm_timer_defaults));
+	osmo_tdefs_reset(asp->cfg.T_defs_lm);
+
+	llist_add_tail(&asp->list, &inst->asp_list);
+
+	/* The SUA code internally needs SCCP to work */
+	if (proto == OSMO_SS7_ASP_PROT_SUA)
+		osmo_ss7_ensure_sccp(inst);
+	return asp;
+}
+
+void osmo_ss7_asp_destroy(struct osmo_ss7_asp *asp)
+{
+	struct osmo_ss7_as *as;
+
+	OSMO_ASSERT(ss7_initialized);
+	LOGPASP(asp, DLSS7, LOGL_INFO, "Destroying ASP\n");
+
+	if (asp->server)
+		osmo_stream_srv_destroy(asp->server);
+	if (asp->client)
+		osmo_stream_cli_destroy(asp->client);
+	if (asp->fi)
+		osmo_fsm_inst_term(asp->fi, OSMO_FSM_TERM_REQUEST, NULL);
+	if (asp->xua_server)
+		llist_del(&asp->siblings);
+
+	/* unlink from all ASs we are part of */
+	llist_for_each_entry(as, &asp->inst->as_list, list) {
+		unsigned int i;
+		for (i = 0; i < ARRAY_SIZE(as->cfg.asps); i++) {
+			if (as->cfg.asps[i] == asp)
+				as->cfg.asps[i] = NULL;
+		}
+	}
+	/* unlink from ss7_instance */
+	asp->inst = NULL;
+	llist_del(&asp->list);
+	rate_ctr_group_free(asp->ctrg);
+	/* release memory */
+	talloc_free(asp);
+}
+
+static int xua_cli_read_cb(struct osmo_stream_cli *conn);
+static int ipa_cli_read_cb(struct osmo_stream_cli *conn);
+static int xua_cli_connect_cb(struct osmo_stream_cli *cli);
+
+int osmo_ss7_asp_restart(struct osmo_ss7_asp *asp)
+{
+	int rc;
+	char bufloc[512], bufrem[512];
+
+	OSMO_ASSERT(ss7_initialized);
+	osmo_ss7_asp_peer_snprintf(bufloc, sizeof(bufloc), &asp->cfg.local);
+	osmo_ss7_asp_peer_snprintf(bufrem, sizeof(bufrem), &asp->cfg.remote);
+	LOGPASP(asp, DLSS7, LOGL_INFO, "Restarting ASP %s, r=%s<->l=%s\n",
+	       asp->cfg.name, bufrem, bufloc);
+
+	if (!asp->cfg.is_server) {
+		/* We are in client mode now */
+		if (asp->server) {
+			/* if we previously were in server mode,
+			 * destroy it */
+			osmo_stream_srv_destroy(asp->server);
+			asp->server = NULL;
+		}
+		if (!asp->client)
+			asp->client = osmo_stream_cli_create(asp);
+		if (!asp->client) {
+			LOGPASP(asp, DLSS7, LOGL_ERROR, "Unable to create stream"
+				" client for ASP %s\n", asp->cfg.name);
+			return -1;
+		}
+		osmo_stream_cli_set_name(asp->client, asp->cfg.name);
+		osmo_stream_cli_set_nodelay(asp->client, true);
+		osmo_stream_cli_set_addrs(asp->client, (const char **)asp->cfg.remote.host, asp->cfg.remote.host_cnt);
+		osmo_stream_cli_set_port(asp->client, asp->cfg.remote.port);
+		osmo_stream_cli_set_local_addrs(asp->client, (const char **)asp->cfg.local.host, asp->cfg.local.host_cnt);
+		osmo_stream_cli_set_local_port(asp->client, asp->cfg.local.port);
+		osmo_stream_cli_set_proto(asp->client, ss7_asp_proto_to_ip_proto(asp->cfg.proto));
+		osmo_stream_cli_set_reconnect_timeout(asp->client, 5);
+		osmo_stream_cli_set_connect_cb(asp->client, xua_cli_connect_cb);
+		if (asp->cfg.proto == OSMO_SS7_ASP_PROT_IPA)
+			osmo_stream_cli_set_read_cb(asp->client, ipa_cli_read_cb);
+		else
+			osmo_stream_cli_set_read_cb(asp->client, xua_cli_read_cb);
+		osmo_stream_cli_set_data(asp->client, asp);
+		rc = osmo_stream_cli_open(asp->client);
+		if (rc < 0) {
+			LOGPASP(asp, DLSS7, LOGL_ERROR, "Unable to open stream"
+				" client for ASP %s, %s ==> %s\n", asp->cfg.name, bufloc, bufrem);
+			/* we don't return error in here because osmo_stream_cli_open()
+			   will continue to retry (due to timeout being explicitly set with
+			   osmo_stream_cli_set_reconnect_timeout() above) to connect so the error is transient */
+		}
+	} else {
+		/* We are in server mode now */
+		if (asp->client) {
+			/* if we previously were in client mode,
+			 * destroy it */
+			osmo_stream_cli_destroy(asp->client);
+			asp->client = NULL;
+		}
+		/* FIXME: ensure we have a SCTP server */
+		LOGPASP(asp, DLSS7, LOGL_NOTICE, "ASP Restart for server "
+			"not implemented yet!\n");
+	}
+
+	/* (re)start the ASP FSM */
+	if (asp->fi)
+		osmo_fsm_inst_term(asp->fi, OSMO_FSM_TERM_REQUEST, NULL);
+	asp->fi = xua_asp_fsm_start(asp, asp->cfg.role, LOGL_DEBUG);
+
+	return 0;
+}
+
+bool osmo_ss7_asp_active(const struct osmo_ss7_asp *asp)
+{
+	if (!asp->fi)
+		return false;
+	return asp->fi->state == XUA_ASP_S_ACTIVE;
+}
+
+/***********************************************************************
+ * libosmo-netif integration for SCTP stream server/client
+ ***********************************************************************/
+
+static int get_logevel_by_sn_type(int sn_type)
+{
+	switch (sn_type) {
+	case SCTP_ADAPTATION_INDICATION:
+	case SCTP_PEER_ADDR_CHANGE:
+#ifdef SCTP_AUTHENTICATION_INDICATION
+	case SCTP_AUTHENTICATION_INDICATION:
+#endif
+#ifdef SCTP_SENDER_DRY_EVENT
+	case SCTP_SENDER_DRY_EVENT:
+#endif
+		return LOGL_INFO;
+	case SCTP_ASSOC_CHANGE:
+		return LOGL_NOTICE;
+	case SCTP_SHUTDOWN_EVENT:
+	case SCTP_PARTIAL_DELIVERY_EVENT:
+		return LOGL_NOTICE;
+	case SCTP_SEND_FAILED:
+	case SCTP_REMOTE_ERROR:
+		return LOGL_ERROR;
+	default:
+		return LOGL_NOTICE;
+	}
+}
+
+static void log_sctp_notification(struct osmo_ss7_asp *asp, const char *pfx,
+				  union sctp_notification *notif)
+{
+	int log_level;
+
+	LOGPASP(asp, DLSS7, LOGL_INFO, "%s SCTP NOTIFICATION %u flags=0x%0x\n",
+		pfx, notif->sn_header.sn_type,
+		notif->sn_header.sn_flags);
+
+	log_level = get_logevel_by_sn_type(notif->sn_header.sn_type);
+
+	switch (notif->sn_header.sn_type) {
+	case SCTP_ASSOC_CHANGE:
+		LOGPASP(asp, DLSS7, log_level, "%s SCTP_ASSOC_CHANGE: %s\n",
+			pfx, osmo_sctp_assoc_chg_str(notif->sn_assoc_change.sac_state));
+		break;
+	case SCTP_PEER_ADDR_CHANGE:
+		{
+		char addr_str[INET6_ADDRSTRLEN + 10];
+		struct sockaddr_storage sa = notif->sn_paddr_change.spc_aaddr;
+		osmo_sockaddr_to_str_buf(addr_str, sizeof(addr_str), (const struct osmo_sockaddr *)&sa);
+		LOGPASP(asp, DLSS7, log_level, "%s SCTP_PEER_ADDR_CHANGE: %s %s err=%s\n",
+			pfx, osmo_sctp_paddr_chg_str(notif->sn_paddr_change.spc_state), addr_str,
+			(notif->sn_paddr_change.spc_state == SCTP_ADDR_UNREACHABLE) ?
+			osmo_sctp_sn_error_str(notif->sn_paddr_change.spc_error) : "None");
+		}
+		break;
+	default:
+		LOGPASP(asp, DLSS7, log_level, "%s %s\n",
+			pfx, osmo_sctp_sn_type_str(notif->sn_header.sn_type));
+		break;
+	}
+}
+
+/* netif code tells us we can read something from the socket */
+int ss7_asp_ipa_srv_conn_cb(struct osmo_stream_srv *conn)
+{
+	struct osmo_fd *ofd = osmo_stream_srv_get_ofd(conn);
+	struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(conn);
+	struct msgb *msg = NULL;
+	int rc;
+
+	/* read IPA message from socket and process it */
+	rc = ipa_msg_recv_buffered(ofd->fd, &msg, &asp->pending_msg);
+	LOGPASP(asp, DLSS7, LOGL_DEBUG, "%s(): ipa_msg_recv_buffered() returned %d\n",
+		__func__, rc);
+	if (rc <= 0) {
+		if (rc == -EAGAIN) {
+			/* more data needed */
+			return 0;
+		}
+		osmo_stream_srv_destroy(conn);
+		return rc;
+	}
+	if (osmo_ipa_process_msg(msg) < 0) {
+		LOGPASP(asp, DLSS7, LOGL_ERROR, "Bad IPA message\n");
+		osmo_stream_srv_destroy(conn);
+		msgb_free(msg);
+		return -1;
+	}
+	msg->dst = asp;
+
+	return ipa_rx_msg(asp, msg, ofd->fd & 0xf);
+}
+
+/* netif code tells us we can read something from the socket */
+int ss7_asp_xua_srv_conn_cb(struct osmo_stream_srv *conn)
+{
+	struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(conn);
+	struct msgb *msg = m3ua_msgb_alloc("xUA Server Rx");
+	unsigned int ppid;
+	int flags;
+	int rc;
+
+	if (!msg)
+		return -ENOMEM;
+
+	/* read xUA message from socket and process it */
+	rc = osmo_stream_srv_recv(conn, msg);
+	flags = msgb_sctp_msg_flags(msg);
+
+	LOGPASP(asp, DLSS7, LOGL_DEBUG, "%s(): sctp_recvmsg() returned %d (flags=0x%x)\n",
+		__func__, rc, flags);
+
+	if (flags & OSMO_STREAM_SCTP_MSG_FLAGS_NOTIFICATION) {
+		union sctp_notification *notif = (union sctp_notification *) msgb_data(msg);
+		log_sctp_notification(asp, "xUA CLNT", notif);
+		asp_handle_sctp_notif_monitor_primary_address(asp, notif);
+
+		switch (notif->sn_header.sn_type) {
+		case SCTP_ASSOC_CHANGE:
+			if (notif->sn_assoc_change.sac_state == SCTP_RESTART)
+				xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_RESTART,
+							     PRIM_OP_INDICATION);
+		default:
+			break;
+		}
+
+		if (rc == 0) {
+			osmo_stream_srv_destroy(conn);
+			rc = -EBADF;
+		} else {
+			rc = 0;
+		}
+		goto out;
+	}
+	if (rc < 0) {
+		osmo_stream_srv_destroy(conn);
+		rc = -EBADF;
+		goto out;
+	} else if (rc == 0) {
+		osmo_stream_srv_destroy(conn);
+		rc = -EBADF;
+		goto out;
+	}
+
+	ppid = msgb_sctp_ppid(msg);
+	msg->dst = asp;
+	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_RX_TOTAL);
+
+	if (ppid == SUA_PPID && asp->cfg.proto == OSMO_SS7_ASP_PROT_SUA)
+		rc = sua_rx_msg(asp, msg);
+	else if (ppid == M3UA_PPID && asp->cfg.proto == OSMO_SS7_ASP_PROT_M3UA)
+		rc = m3ua_rx_msg(asp, msg);
+	else
+		rc = ss7_asp_rx_unknown(asp, ppid, msg);
+
+out:
+	msgb_free(msg);
+	return rc;
+}
+
+/* client has established SCTP connection to server */
+static int xua_cli_connect_cb(struct osmo_stream_cli *cli)
+{
+	struct osmo_fd *ofd = osmo_stream_cli_get_ofd(cli);
+	struct osmo_ss7_asp *asp = osmo_stream_cli_get_data(cli);
+	int rc = 0;
+
+	/* update the socket name */
+	talloc_free(asp->sock_name);
+	asp->sock_name = osmo_sock_get_name(asp, ofd->fd);
+
+	LOGPASP(asp, DLSS7, LOGL_INFO, "Client connected %s\n", asp->sock_name);
+
+	/* Now that we have the conn in place, the local/remote addresses are
+	 * fed and the local port is known for sure. Apply SCTP Primary addresses
+	 * if needed:
+	 */
+	if (asp->cfg.proto != OSMO_SS7_ASP_PROT_IPA) {
+		rc = ss7_asp_apply_peer_primary_address(asp);
+		rc = ss7_asp_apply_primary_address(asp);
+	}
+
+	if (asp->lm && asp->lm->prim_cb) {
+		/* Notify layer manager that a connection has been
+		 * established */
+		xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_ESTABLISH, PRIM_OP_INDICATION);
+	} else {
+		/* directly as the ASP FSM to start by sending an ASP-UP ... */
+		osmo_fsm_inst_dispatch(asp->fi, XUA_ASP_E_M_ASP_UP_REQ, NULL);
+	}
+
+	return rc;
+}
+
+static void xua_cli_close(struct osmo_stream_cli *cli)
+{
+	struct osmo_ss7_asp *asp = osmo_stream_cli_get_data(cli);
+
+	osmo_stream_cli_close(cli);
+	osmo_fsm_inst_dispatch(asp->fi, XUA_ASP_E_SCTP_COMM_DOWN_IND, asp);
+	/* send M-SCTP_RELEASE.ind to XUA Layer Manager */
+	xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_RELEASE, PRIM_OP_INDICATION);
+}
+
+static void xua_cli_close_and_reconnect(struct osmo_stream_cli *cli)
+{
+	xua_cli_close(cli);
+	osmo_stream_cli_reconnect(cli);
+}
+
+/* read call-back for IPA/SCCPlite socket */
+static int ipa_cli_read_cb(struct osmo_stream_cli *conn)
+{
+	struct osmo_fd *ofd = osmo_stream_cli_get_ofd(conn);
+	struct osmo_ss7_asp *asp = osmo_stream_cli_get_data(conn);
+	struct msgb *msg = NULL;
+	int rc;
+
+	/* read IPA message from socket and process it */
+	rc = ipa_msg_recv_buffered(ofd->fd, &msg, &asp->pending_msg);
+	LOGPASP(asp, DLSS7, LOGL_DEBUG, "%s(): ipa_msg_recv_buffered() returned %d\n",
+		__func__, rc);
+	if (rc <= 0) {
+		if (rc == -EAGAIN) {
+			/* more data needed */
+			return 0;
+		}
+		xua_cli_close_and_reconnect(conn);
+		return rc;
+	}
+	if (osmo_ipa_process_msg(msg) < 0) {
+		LOGPASP(asp, DLSS7, LOGL_ERROR, "Bad IPA message\n");
+		xua_cli_close_and_reconnect(conn);
+		msgb_free(msg);
+		return -1;
+	}
+	msg->dst = asp;
+	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_RX_TOTAL);
+	return ipa_rx_msg(asp, msg, ofd->fd & 0xf);
+}
+
+static int xua_cli_read_cb(struct osmo_stream_cli *conn)
+{
+	struct osmo_ss7_asp *asp = osmo_stream_cli_get_data(conn);
+	struct msgb *msg = m3ua_msgb_alloc("xUA Client Rx");
+	unsigned int ppid;
+	int flags;
+	int rc;
+
+	if (!msg)
+		return -ENOMEM;
+
+	/* read xUA message from socket and process it */
+	rc = osmo_stream_cli_recv(conn, msg);
+	flags = msgb_sctp_msg_flags(msg);
+
+	LOGPASP(asp, DLSS7, LOGL_DEBUG, "%s(): sctp_recvmsg() returned %d (flags=0x%x)\n",
+		__func__, rc, flags);
+
+	if (flags & OSMO_STREAM_SCTP_MSG_FLAGS_NOTIFICATION) {
+		union sctp_notification *notif = (union sctp_notification *) msgb_data(msg);
+		log_sctp_notification(asp, "xUA CLNT", notif);
+		asp_handle_sctp_notif_monitor_primary_address(asp, notif);
+
+		switch (notif->sn_header.sn_type) {
+		case SCTP_ASSOC_CHANGE:
+			if (notif->sn_assoc_change.sac_state == SCTP_RESTART)
+				xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_RESTART,
+							     PRIM_OP_INDICATION);
+		default:
+			break;
+		}
+
+		if (rc == 0)
+			xua_cli_close_and_reconnect(conn);
+		rc = 0;
+		goto out;
+	}
+	if (rc < 0) {
+		xua_cli_close_and_reconnect(conn);
+		goto out;
+	} else if (rc == 0) {
+		xua_cli_close_and_reconnect(conn);
+		goto out;
+	}
+
+	ppid = msgb_sctp_ppid(msg);
+	msg->dst = asp;
+	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_RX_TOTAL);
+
+	if (ppid == SUA_PPID && asp->cfg.proto == OSMO_SS7_ASP_PROT_SUA)
+		rc = sua_rx_msg(asp, msg);
+	else if (ppid == M3UA_PPID && asp->cfg.proto == OSMO_SS7_ASP_PROT_M3UA)
+		rc = m3ua_rx_msg(asp, msg);
+	else
+		rc = ss7_asp_rx_unknown(asp, ppid, msg);
+
+out:
+	msgb_free(msg);
+	return rc;
+}
+
+int ss7_asp_xua_srv_conn_closed_cb(struct osmo_stream_srv *srv)
+{
+	struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(srv);
+
+	LOGP(DLSS7, LOGL_INFO, "%s: connection closed\n", asp ? asp->cfg.name : "?");
+
+	if (!asp)
+		return 0;
+
+	/* notify ASP FSM and everyone else */
+	osmo_fsm_inst_dispatch(asp->fi, XUA_ASP_E_SCTP_COMM_DOWN_IND, NULL);
+
+	/* delete any RKM-dynamically allocated ASs for this ASP */
+	xua_rkm_cleanup_dyn_as_for_asp(asp);
+
+	/* send M-SCTP_RELEASE.ind to Layer Manager */
+	xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_RELEASE, PRIM_OP_INDICATION);
+
+	asp->server = NULL;
+
+	/* if we were dynamically allocated at accept_cb() time, let's
+	 * self-destruct now.  A new connection will re-create the ASP. */
+	if (asp->dyn_allocated) {
+		/* avoid re-entrance via osmo_stream_srv_destroy() which
+		 * called us */
+		osmo_ss7_asp_destroy(asp);
+	}
+
+	return 0;
+}
+
+/*! \brief send a fully encoded msgb via a given ASP
+ *  \param[in] asp Application Server Process through which to send
+ *  \param[in] msg message buffer to transmit. Ownership transferred.
+ *  \returns 0 on success; negative in case of error */
+int osmo_ss7_asp_send(struct osmo_ss7_asp *asp, struct msgb *msg)
+{
+	OSMO_ASSERT(ss7_initialized);
+
+	switch (asp->cfg.proto) {
+	case OSMO_SS7_ASP_PROT_SUA:
+		msgb_sctp_ppid(msg) = SUA_PPID;
+		break;
+	case OSMO_SS7_ASP_PROT_M3UA:
+		msgb_sctp_ppid(msg) = M3UA_PPID;
+		break;
+	case OSMO_SS7_ASP_PROT_IPA:
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+
+	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_TX_TOTAL);
+
+	if (asp->cfg.is_server) {
+		if (!asp->server) {
+			LOGPASP(asp, DLSS7, LOGL_ERROR, "Cannot transmit, no asp->server\n");
+			/* FIXME: what to do here? delete the route? send DUNA? */
+			msgb_free(msg);
+			return -EIO;
+		}
+		osmo_stream_srv_send(asp->server, msg);
+	} else {
+		if (!asp->client) {
+			LOGPASP(asp, DLSS7, LOGL_ERROR, "Cannot transmit, no asp->client\n");
+			/* FIXME: what to do here? delete the route? send DUNA? */
+			msgb_free(msg);
+			return -EIO;
+		}
+		if (!osmo_stream_cli_is_connected(asp->client)) {
+			LOGPASP(asp, DLSS7, LOGL_ERROR, "Cannot transmit, asp->client not connected\n");
+			msgb_free(msg);
+			return -EIO;
+		}
+		osmo_stream_cli_send(asp->client, msg);
+	}
+
+	return 0;
+}
+
+void osmo_ss7_asp_disconnect(struct osmo_ss7_asp *asp)
+{
+	if (asp->server)
+		osmo_stream_srv_destroy(asp->server);
+		/* the close_cb() will handle the remaining cleanup here */
+	else if (asp->client)
+		xua_cli_close_and_reconnect(asp->client);
+}
+
+static osmo_ss7_asp_rx_unknown_cb *g_osmo_ss7_asp_rx_unknown_cb;
+
+/*! Register a call-back function for unknown SCTP PPID / IPA Stream ID */
+void osmo_ss7_register_rx_unknown_cb(osmo_ss7_asp_rx_unknown_cb *cb)
+{
+	g_osmo_ss7_asp_rx_unknown_cb = cb;
+}
+
+int ss7_asp_rx_unknown(struct osmo_ss7_asp *asp, int ppid_mux, struct msgb *msg)
+{
+	rate_ctr_inc2(asp->ctrg, SS7_ASP_CTR_PKT_RX_UNKNOWN);
+
+	if (g_osmo_ss7_asp_rx_unknown_cb)
+		return (*g_osmo_ss7_asp_rx_unknown_cb)(asp, ppid_mux, msg);
+
+	switch (asp->cfg.proto) {
+	case OSMO_SS7_ASP_PROT_IPA:
+		LOGPASP(asp, DLSS7, LOGL_NOTICE, "Rx IPA for unknown Stream ID 0x%02x: %s\n",
+			ppid_mux, msgb_hexdump(msg));
+		break;
+	default:
+		LOGPASP(asp, DLSS7, LOGL_NOTICE, "Rx SCTP chunk for unknown PPID %u: %s\n",
+			ppid_mux, msgb_hexdump(msg));
+		break;
+	}
+	return 0;
+}
+
+/*! Get the logging subsystem for a given ASP. Used by generic code. */
+int osmo_ss7_asp_get_log_subsys(const struct osmo_ss7_asp *asp)
+{
+	switch (asp->cfg.proto) {
+	case OSMO_SS7_ASP_PROT_M3UA:
+		return DLM3UA;
+	case OSMO_SS7_ASP_PROT_SUA:
+		return DLSUA;
+	default:
+		return DLSS7;
+	}
+}
+
+/*! \brief Get the name of a given ASP
+ *  \param[in] asp The ASP for which the name is requested
+ *  \returns The name of the ASP, or NULL if not set
+ */
+const char *osmo_ss7_asp_get_name(const struct osmo_ss7_asp *asp)
+{
+	return asp->cfg.name;
+}
+
+/*! \brief Get the proto of a given ASP
+ *  \param[in] asp The ASP for which the proto is requested
+ *  \returns The proto of the ASP
+ */
+enum osmo_ss7_asp_protocol osmo_ss7_asp_get_proto(const struct osmo_ss7_asp *asp)
+{
+	return asp->cfg.proto;
+}
diff --git a/src/osmo_ss7_xua_srv.c b/src/osmo_ss7_xua_srv.c
new file mode 100644
index 0000000..04ae893
--- /dev/null
+++ b/src/osmo_ss7_xua_srv.c
@@ -0,0 +1,300 @@
+/* Core SS7 xUA Server */
+
+/* (C) 2015-2017 by Harald Welte laforge@gnumonks.org
+ * (C) 2023 by sysmocom s.f.m.c. GmbH info@sysmocom.de
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/.
+ *
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/sctp.h>
+
+#include <osmocom/sigtran/osmo_ss7.h>
+#include <osmocom/sigtran/mtp_sap.h>
+#include <osmocom/sigtran/protocol/mtp.h>
+#include <osmocom/sigtran/protocol/sua.h>
+#include <osmocom/sigtran/protocol/m3ua.h>
+
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/sockaddr_str.h>
+
+#include <osmocom/netif/stream.h>
+#include <osmocom/netif/ipa.h>
+#include <osmocom/netif/sctp.h>
+
+#include "sccp_internal.h"
+#include "xua_internal.h"
+#include "ss7_internal.h"
+#include "xua_asp_fsm.h"
+#include "xua_as_fsm.h"
+
+/***********************************************************************
+ * SS7 xUA Server
+ ***********************************************************************/
+
+/* server has accept()ed a new SCTP association, let's find the ASP for
+ * it (if any) */
+static int xua_accept_cb(struct osmo_stream_srv_link *link, int fd)
+{
+	struct osmo_xua_server *oxs = osmo_stream_srv_link_get_data(link);
+	struct osmo_stream_srv *srv;
+	struct osmo_ss7_asp *asp;
+	char *sock_name = osmo_sock_get_name(link, fd);
+	const char *proto_name = get_value_string(osmo_ss7_asp_protocol_vals, oxs->cfg.proto);
+	int rc = 0;
+
+	LOGP(DLSS7, LOGL_INFO, "%s: New %s connection accepted\n", sock_name, proto_name);
+
+	if (oxs->cfg.proto == OSMO_SS7_ASP_PROT_IPA) {
+		srv = osmo_stream_srv_create(oxs, link, fd,
+					     ss7_asp_ipa_srv_conn_cb,
+					     ss7_asp_xua_srv_conn_closed_cb, NULL);
+	} else {
+		srv = osmo_stream_srv_create(oxs, link, fd,
+					     ss7_asp_xua_srv_conn_cb,
+					     ss7_asp_xua_srv_conn_closed_cb, NULL);
+	}
+	if (!srv) {
+		LOGP(DLSS7, LOGL_ERROR, "%s: Unable to create stream server "
+		     "for connection\n", sock_name);
+		close(fd);
+		talloc_free(sock_name);
+		return -1;
+	}
+
+	asp = ss7_asp_find_by_socket_addr(fd);
+	if (asp) {
+		LOGP(DLSS7, LOGL_INFO, "%s: matched connection to ASP %s\n",
+			sock_name, asp->cfg.name);
+		/* we need to check if we already have a socket associated, and close it.  Otherwise it might
+		 * happen that both the listen-fd for this accept() and the old socket are marked 'readable'
+		 * during the same scheduling interval, and we're processing them in the "wrong" order, i.e.
+		 * we first see the accept of the new fd before we see the close on the old fd */
+		if (asp->server) {
+			LOGPASP(asp, DLSS7, LOGL_FATAL, "accept of new connection from %s before old was closed "
+				"-> close old one\n", sock_name);
+			osmo_stream_srv_set_data(asp->server, NULL);
+			osmo_stream_srv_destroy(asp->server);
+			asp->server = NULL;
+		}
+	} else {
+		if (!oxs->cfg.accept_dyn_reg) {
+			LOGP(DLSS7, LOGL_NOTICE, "%s: %s connection without matching "
+			     "ASP definition and no dynamic registration enabled, terminating\n",
+			     sock_name, proto_name);
+		} else {
+			char namebuf[32];
+			static uint32_t dyn_asp_num = 0;
+			snprintf(namebuf, sizeof(namebuf), "asp-dyn-%u", dyn_asp_num++);
+			asp = osmo_ss7_asp_find_or_create(oxs->inst, namebuf, 0, 0,
+							  oxs->cfg.proto);
+			if (asp) {
+				char hostbuf[INET6_ADDRSTRLEN];
+				const char *hostbuf_ptr = &hostbuf[0];
+				char portbuf[16];
+
+				osmo_sock_get_ip_and_port(fd, hostbuf, sizeof(hostbuf), portbuf, sizeof(portbuf), false);
+				LOGP(DLSS7, LOGL_INFO, "%s: created dynamic ASP %s\n",
+					sock_name, asp->cfg.name);
+				asp->cfg.is_server = true;
+				asp->cfg.role = OSMO_SS7_ASP_ROLE_SG;
+				asp->cfg.local.port = oxs->cfg.local.port;
+				asp->cfg.remote.port = atoi(portbuf);
+				asp->dyn_allocated = true;
+				asp->server = srv;
+				osmo_ss7_asp_peer_set_hosts(&asp->cfg.local, asp,
+							    (const char * const*)oxs->cfg.local.host,
+							    oxs->cfg.local.host_cnt);
+				osmo_ss7_asp_peer_set_hosts(&asp->cfg.remote, asp,
+							    &hostbuf_ptr, 1);
+				osmo_ss7_asp_restart(asp);
+			}
+		}
+		if (!asp) {
+			osmo_stream_srv_destroy(srv);
+			talloc_free(sock_name);
+			return -1;
+		}
+		llist_add_tail(&asp->siblings, &oxs->asp_list);
+	}
+
+	/* update the ASP reference back to the server over which the
+	 * connection came in */
+	asp->server = srv;
+	asp->xua_server = oxs;
+
+	/* update the ASP socket name */
+	talloc_free(asp->sock_name);
+	asp->sock_name = talloc_reparent(link, asp, sock_name);
+	osmo_stream_srv_set_name(asp->server, asp->cfg.name);
+	/* make sure the conn_cb() is called with the asp as private
+	 * data */
+	osmo_stream_srv_set_data(srv, asp);
+
+	if (oxs->cfg.proto != OSMO_SS7_ASP_PROT_IPA) {
+		rc = ss7_asp_apply_peer_primary_address(asp);
+		rc = ss7_asp_apply_primary_address(asp);
+	}
+
+	/* send M-SCTP_ESTABLISH.ind to Layer Manager */
+	osmo_fsm_inst_dispatch(asp->fi, XUA_ASP_E_SCTP_EST_IND, 0);
+	xua_asp_send_xlm_prim_simple(asp, OSMO_XLM_PRIM_M_SCTP_ESTABLISH, PRIM_OP_INDICATION);
+
+	return rc;
+}
+
+/*! \brief create a new xUA server configured with given ip/port
+ *  \param[in] ctx talloc allocation context
+ *  \param[in] proto protocol (xUA variant) to use
+ *  \param[in] local_port local SCTP port to bind/listen to
+ *  \param[in] local_host local IP address to bind/listen to (optional)
+ *  \returns callee-allocated \ref osmo_xua_server in case of success
+ */
+struct osmo_xua_server *
+osmo_ss7_xua_server_create(struct osmo_ss7_instance *inst, enum osmo_ss7_asp_protocol proto,
+			   uint16_t local_port, const char *local_host)
+{
+	struct osmo_xua_server *oxs = talloc_zero(inst, struct osmo_xua_server);
+
+	OSMO_ASSERT(ss7_initialized);
+	if (!oxs)
+		return NULL;
+
+	LOGP(DLSS7, LOGL_INFO, "Creating %s Server %s:%u\n",
+		get_value_string(osmo_ss7_asp_protocol_vals, proto), local_host, local_port);
+
+	INIT_LLIST_HEAD(&oxs->asp_list);
+
+	oxs->cfg.proto = proto;
+	oxs->cfg.local.port = local_port;
+
+	oxs->server = osmo_stream_srv_link_create(oxs);
+	osmo_stream_srv_link_set_name(oxs->server, osmo_ss7_asp_protocol_name(proto));
+	osmo_stream_srv_link_set_data(oxs->server, oxs);
+	osmo_stream_srv_link_set_accept_cb(oxs->server, xua_accept_cb);
+
+	osmo_stream_srv_link_set_nodelay(oxs->server, true);
+	osmo_stream_srv_link_set_port(oxs->server, oxs->cfg.local.port);
+	osmo_stream_srv_link_set_proto(oxs->server, ss7_asp_proto_to_ip_proto(proto));
+
+	osmo_ss7_xua_server_set_local_host(oxs, local_host);
+
+	LOGP(DLSS7, LOGL_INFO, "Created %s server on %s:%" PRIu16 "\n",
+		get_value_string(osmo_ss7_asp_protocol_vals, proto), local_host, local_port);
+
+	oxs->inst = inst;
+	llist_add_tail(&oxs->list, &inst->xua_servers);
+
+	/* The SUA code internally needs SCCP to work */
+	if (proto == OSMO_SS7_ASP_PROT_SUA)
+		osmo_ss7_ensure_sccp(inst);
+
+	return oxs;
+}
+
+/*! \brief Set the xUA server to bind/listen to the currently configured ip/port
+ *  \param[in] xs xUA server to operate
+ *  \returns 0 on success, negative value on error.
+ */
+int
+osmo_ss7_xua_server_bind(struct osmo_xua_server *xs)
+{
+	char buf[512];
+	int rc;
+	const char *proto = get_value_string(osmo_ss7_asp_protocol_vals, xs->cfg.proto);
+
+	rc = osmo_ss7_asp_peer_snprintf(buf, sizeof(buf), &xs->cfg.local);
+	if (rc < 0) {
+		LOGP(DLSS7, LOGL_INFO, "Failed parsing %s Server osmo_ss7_asp_peer\n", proto);
+	} else {
+		LOGP(DLSS7, LOGL_INFO, "(Re)binding %s Server to %s\n",
+		     proto, buf);
+	}
+	return osmo_stream_srv_link_open(xs->server);
+}
+
+int
+osmo_ss7_xua_server_set_local_host(struct osmo_xua_server *xs, const char *local_host)
+{
+	return osmo_ss7_xua_server_set_local_hosts(xs, &local_host, 1);
+}
+
+int
+osmo_ss7_xua_server_set_local_hosts(struct osmo_xua_server *xs, const char **local_hosts, size_t local_host_cnt)
+{
+	int rc;
+	OSMO_ASSERT(ss7_initialized);
+
+	rc = osmo_ss7_asp_peer_set_hosts(&xs->cfg.local, xs, local_hosts, local_host_cnt);
+	if (rc < 0)
+		return rc;
+	return osmo_stream_srv_link_set_addrs(xs->server, (const char **)xs->cfg.local.host, xs->cfg.local.host_cnt);
+}
+
+int
+osmo_ss7_xua_server_add_local_host(struct osmo_xua_server *xs, const char *local_host)
+{
+	int rc;
+
+	rc = osmo_ss7_asp_peer_add_host(&xs->cfg.local, xs, local_host);
+	if (rc < 0)
+		return rc;
+	return osmo_stream_srv_link_set_addrs(xs->server, (const char **)xs->cfg.local.host, xs->cfg.local.host_cnt);
+}
+
+bool ss7_xua_server_set_default_local_hosts(struct osmo_xua_server *oxs)
+{
+	/* If no local addr was set, or erased after _create(): */
+	if (!oxs->cfg.local.host_cnt) {
+		/* "::" Covers both IPv4 and IPv6 */
+		if (ss7_ipv6_sctp_supported("::", true))
+			osmo_ss7_xua_server_set_local_host(oxs, "::");
+		else
+			osmo_ss7_xua_server_set_local_host(oxs, "0.0.0.0");
+		return true;
+	}
+	return false;
+}
+
+void osmo_ss7_xua_server_destroy(struct osmo_xua_server *xs)
+{
+	struct osmo_ss7_asp *asp, *asp2;
+
+	if (xs->server) {
+		osmo_stream_srv_link_close(xs->server);
+		osmo_stream_srv_link_destroy(xs->server);
+	}
+	/* iterate and close all connections established in relation
+	 * with this server */
+	llist_for_each_entry_safe(asp, asp2, &xs->asp_list, siblings)
+		osmo_ss7_asp_destroy(asp);
+
+	llist_del(&xs->list);
+	talloc_free(xs);
+}
diff --git a/src/ss7_internal.h b/src/ss7_internal.h
index f6669e2..34378e8 100644
--- a/src/ss7_internal.h
+++ b/src/ss7_internal.h
@@ -5,10 +5,31 @@
 #include <stdbool.h>
 #include <osmocom/sigtran/osmo_ss7.h>
+extern bool ss7_initialized;
+
+bool ss7_ipv6_sctp_supported(const char *host, bool bind);
+
+struct osmo_ss7_asp *ss7_asp_alloc(struct osmo_ss7_instance *inst, const char *name,
+				   uint16_t remote_port, uint16_t local_port,
+				   enum osmo_ss7_asp_protocol proto);
 bool ss7_asp_set_default_peer_hosts(struct osmo_ss7_asp *asp);
+struct osmo_ss7_asp *ss7_asp_find_by_socket_addr(int fd);
+int ss7_asp_proto_to_ip_proto(enum osmo_ss7_asp_protocol proto);
+int ss7_asp_ipa_srv_conn_cb(struct osmo_stream_srv *conn);
+int ss7_asp_xua_srv_conn_cb(struct osmo_stream_srv *conn);
+int ss7_asp_xua_srv_conn_closed_cb(struct osmo_stream_srv *srv);
+int ss7_asp_apply_peer_primary_address(const struct osmo_ss7_asp *asp);
+int ss7_asp_apply_primary_address(const struct osmo_ss7_asp *asp);
+
 bool ss7_xua_server_set_default_local_hosts(struct osmo_xua_server *oxs);
enum ss7_as_ctr {
    SS7_AS_CTR_RX_MSU_TOTAL,
    SS7_AS_CTR_TX_MSU_TOTAL,
 };
+
+enum ss7_asp_ctr {
+	SS7_ASP_CTR_PKT_RX_TOTAL,
+	SS7_ASP_CTR_PKT_RX_UNKNOWN,
+	SS7_ASP_CTR_PKT_TX_TOTAL,
+};
-- 
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Gerrit-Project: libosmo-sccp
Gerrit-Branch: master
Gerrit-Change-Id: I3d43268459d61b0b9f9bec34bf31dc0851fa5e48
Gerrit-Change-Number: 34329
Gerrit-PatchSet: 1
Gerrit-Owner: pespin pespin@sysmocom.de
Gerrit-MessageType: newchange



    