[L] Change in osmo-uecups[master]: Use libosmocore netdev API

21 Mar 2026

pespin has submitted this change. ( https://gerrit.osmocom.org/c/osmo-uecups/+/42444?usp=email )
Change subject: Use libosmocore netdev API
......................................................................
Use libosmocore netdev API
Depends: libosmocore.git Change-Id I75153eb59e96a6a2505dc5b29432c76e5c21ea24
Change-Id: I8f18ef56a6e7186fed88f965fbb34aa390c3bac1
---
A TODO-RELEASE
M daemon/Makefile.am
M daemon/gtp_tunnel.c
M daemon/internal.h
D daemon/netdev.c
M daemon/tun_device.c
6 files changed, 68 insertions(+), 182 deletions(-)
Approvals:
  Jenkins Builder: Verified
  pespin: Looks good to me, approved

diff --git a/TODO-RELEASE b/TODO-RELEASE
new file mode 100644
index 0000000..8eda384
--- /dev/null
+++ b/TODO-RELEASE
@@ -0,0 +1,10 @@
+# When cleaning up this file: bump API version in corresponding Makefile.am and rename corresponding debian/lib*.install
+# according to https://osmocom.org/projects/cellular-infrastructure/wiki/Make_a_new_release
+# In short: https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info....
+# LIBVERSION=c:r:a
+# If the library source code has changed at all since the last update, then increment revision: c:r + 1:a.
+# If any interfaces have been added, removed, or changed since the last update: c + 1:0:a.
+# If any interfaces have been added since the last public release: c:r:a + 1.
+# If any interfaces have been removed or changed since the last public release: c:r:0.
+#library	what		                description / commit summary line
+libosmocore      >1.13.1          osmo_netdev_del_addr()
diff --git a/daemon/Makefile.am b/daemon/Makefile.am
index 1c680a6..89afe7a 100644
--- a/daemon/Makefile.am
+++ b/daemon/Makefile.am
@@ -37,7 +37,6 @@
 osmo_uecups_daemon_SOURCES = \
    cups_client.c \
    utility.c \
-	netdev.c \
    tun_device.c \
    gtp_daemon.c \
    gtp_endpoint.c \
diff --git a/daemon/gtp_tunnel.c b/daemon/gtp_tunnel.c
index a13b163..4c6b2c5 100644
--- a/daemon/gtp_tunnel.c
+++ b/daemon/gtp_tunnel.c
@@ -25,6 +25,7 @@
 struct gtp_tunnel *gtp_tunnel_alloc(struct gtp_daemon *d, const struct gtp_tunnel_params *cpars)
 {
    struct gtp_tunnel *t;
+	int rc;
t = talloc_zero(d, struct gtp_tunnel);
    if (!t)
@@ -60,9 +61,9 @@
    memcpy(&t->user_addr, &cpars->user_addr, sizeof(t->user_addr));
    memcpy(&t->remote_udp, &cpars->remote_udp, sizeof(t->remote_udp));
-	if (netdev_add_addr(t->tun_dev->nl, t->tun_dev->ifindex, &t->user_addr) < 0) {
+	if ((rc = osmo_netdev_add_addr(t->tun_dev->netdev, &t->user_addr, 32)) < 0) {
    	LOGT(t, LOGL_ERROR, "Cannot add user addr to tun device: %s\n",
-			strerror(errno));
+		     strerror(-rc));
    }
/* TODO: hash table? */
@@ -134,12 +135,14 @@
 /* UNLOCKED destroy of tunnel; drops references to EP + TUN */
 void _gtp_tunnel_destroy(struct gtp_tunnel *t)
 {
+	int rc;
+
    LOGT(t, LOGL_NOTICE, "Destroying\n");
    /* talloc is not thread safe, all alloc/free must come from main thread */
    ASSERT_MAIN_THREAD(t->d);
-	if (netdev_del_addr(t->tun_dev->nl, t->tun_dev->ifindex, &t->user_addr) < 0)
-		LOGT(t, LOGL_ERROR, "Cannot remove user address: %s\n", strerror(errno));
+	if ((rc = osmo_netdev_del_addr(t->tun_dev->netdev, &t->user_addr, 32)) < 0)
+		LOGT(t, LOGL_ERROR, "Cannot remove user address: %s\n", strerror(-rc));
llist_del(&t->list);
diff --git a/daemon/internal.h b/daemon/internal.h
index 7a016fa..ae2356b 100644
--- a/daemon/internal.h
+++ b/daemon/internal.h
@@ -13,6 +13,7 @@
 #include <osmocom/core/it_q.h>
 #include <osmocom/core/utils.h>
 #include <osmocom/core/socket.h>
+#include <osmocom/core/netdev.h>
#include <osmocom/netif/stream.h>
@@ -36,15 +37,6 @@
    DUECUPS,
 };
-/***********************************************************************
- * netdev / netlink
- ***********************************************************************/
-
-int netdev_add_addr(struct nl_sock *nlsk, int ifindex, const struct osmo_sockaddr *osa);
-int netdev_del_addr(struct nl_sock *nlsk, int ifindex, const struct osmo_sockaddr *osa);
-int netdev_set_link(struct nl_sock *nlsk, int ifindex, bool up);
-int netdev_add_defaultroute(struct nl_sock *nlsk, int ifindex, uint8_t family);
-
/***********************************************************************
  * GTP Endpoint (UDP socket)
@@ -115,8 +107,7 @@
    const char *netns_name;
    int netns_fd;
-	/* netlink socket in the namespace of the tun device */
-	struct nl_sock *nl;
+	struct osmo_netdev *netdev;
/* list of local addresses? or simply only have the kernel know thses? */
diff --git a/daemon/netdev.c b/daemon/netdev.c
deleted file mode 100644
index 165a6bc..0000000
--- a/daemon/netdev.c
+++ /dev/null
@@ -1,137 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <unistd.h>
-#include <stdint.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-
-#include <netinet/ip.h>
-#include <netinet/ip6.h>
-
-#include <linux/if.h>
-#include <linux/if_tun.h>
-#include <sys/ioctl.h>
-
-#include <linux/netlink.h>
-#include <netlink/socket.h>
-#include <netlink/route/link.h>
-#include <netlink/route/addr.h>
-#include <netlink/route/route.h>
-#include <netlink/route/nexthop.h>
-
-#include <osmocom/core/utils.h>
-#include <osmocom/core/socket.h>
-
-/***********************************************************************
- * netlink helper functions
- ***********************************************************************/
-
-static int _netdev_addr(struct nl_sock *nlsk, int ifindex, const struct osmo_sockaddr *osa, bool add)
-{
-	struct nl_addr *local = NULL;
-	struct rtnl_addr *addr;
-	int rc;
-
-	switch (osa->u.sa.sa_family) {
-	case AF_INET:
-		local = nl_addr_build(AF_INET, &osa->u.sin.sin_addr, 4);
-		break;
-	case AF_INET6:
-		local = nl_addr_build(AF_INET6, &osa->u.sin6.sin6_addr, 16);
-		break;
-	}
-	OSMO_ASSERT(local);
-
-	addr = rtnl_addr_alloc();
-	OSMO_ASSERT(addr);
-	rtnl_addr_set_ifindex(addr, ifindex);
-	OSMO_ASSERT(rtnl_addr_set_local(addr, local) == 0);
-
-	if (add)
-		rc = rtnl_addr_add(nlsk, addr, 0);
-	else
-		rc = rtnl_addr_delete(nlsk, addr, 0);
-
-	rtnl_addr_put(addr);
-
-	return rc;
-}
-
-int netdev_add_addr(struct nl_sock *nlsk, int ifindex, const struct osmo_sockaddr *osa)
-{
-	return _netdev_addr(nlsk, ifindex, osa, true);
-}
-
-int netdev_del_addr(struct nl_sock *nlsk, int ifindex, const struct osmo_sockaddr *osa)
-{
-	return _netdev_addr(nlsk, ifindex, osa, false);
-}
-
-int netdev_set_link(struct nl_sock *nlsk, int ifindex, bool up)
-{
-	struct rtnl_link *link, *change;
-	int rc;
-
-	rc = rtnl_link_get_kernel(nlsk, ifindex, NULL, &link);
-	if (rc < 0)
-		return rc;
-
-	change = rtnl_link_alloc();
-	OSMO_ASSERT(change);
-
-	if (up)
-		rtnl_link_set_flags(change, IFF_UP);
-	else
-		rtnl_link_unset_flags(change, IFF_UP);
-
-	rc = rtnl_link_change(nlsk, link, change, 0);
-
-	rtnl_link_put(change);
-	rtnl_link_put(link);
-
-	return rc;
-}
-
-int netdev_add_defaultroute(struct nl_sock *nlsk, int ifindex, uint8_t family)
-{
-	struct rtnl_route *route = rtnl_route_alloc();
-	struct rtnl_nexthop *nhop = rtnl_route_nh_alloc();
-	struct nl_addr *dst, *gw;
-	uint8_t buf[16];
-	int rc;
-
-	OSMO_ASSERT(route);
-	OSMO_ASSERT(nhop);
-
-	/* destination address of route: all-zero */
-	memset(buf, 0, sizeof(buf));
-	dst = nl_addr_build(family, buf, family == AF_INET ? 4 : 16);
-	OSMO_ASSERT(dst);
-	nl_addr_set_prefixlen(dst, 0);
-
-	/* gateway address of route: also all-zero */
-	gw = nl_addr_clone(dst);
-	OSMO_ASSERT(gw);
-
-	/* nexthop for route */
-	rtnl_route_nh_set_ifindex(nhop, ifindex);
-	rtnl_route_nh_set_gateway(nhop, gw);
-
-	/* tie everything together in the route */
-	rtnl_route_set_dst(route, dst);
-	rtnl_route_set_family(route, family);
-	rtnl_route_add_nexthop(route, nhop);
-
-	rc = rtnl_route_add(nlsk, route, NLM_F_CREATE);
-
-	//rtnl_route_nh_free(nhop);
-	nl_addr_put(gw);
-	nl_addr_put(dst);
-	rtnl_route_put(route);
-
-	return rc;
-}
diff --git a/daemon/tun_device.c b/daemon/tun_device.c
index 837fd9d..c12c694 100644
--- a/daemon/tun_device.c
+++ b/daemon/tun_device.c
@@ -16,7 +16,7 @@
 #include <fcntl.h>
 #include <signal.h>
 #include <netdb.h>
-
+#include <net/if.h>
 #include <netinet/ip.h>
 #include <netinet/ip6.h>
@@ -26,10 +26,6 @@
 #include <linux/if_tun.h>
 #include <sys/ioctl.h>
-#include <linux/netlink.h>
-#include <netlink/socket.h>
-#include <netlink/route/link.h>
-
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/logging.h>
@@ -318,9 +314,9 @@
 static struct tun_device *
 _tun_device_create(struct gtp_daemon *d, const char *devname, const char *netns_name)
 {
-	struct rtnl_link *link;
    struct tun_device *tun;
    struct osmo_netns_switch_state switch_state;
+	bool inside_netns = false;
    int rc;
tun = talloc_zero(d, struct tun_device);
@@ -349,6 +345,7 @@
    			tun->netns_name, strerror(errno));
    		goto err_close_ns;
    	}
+		inside_netns = true;
    }
tun->fd = tun_open(0, tun->devname);
@@ -357,49 +354,72 @@
    	goto err_restore_ns;
    }
-	tun->nl = nl_socket_alloc();
-	if (!tun->nl || nl_connect(tun->nl, NETLINK_ROUTE) < 0) {
-		LOGTUN(tun, LOGL_ERROR, "Cannot create netlink socket in namespace '%s'\n",
-			tun->netns_name);
+	/* Store interface index:
+	 * (Note: there's a potential race condition here between creating the
+	 * iface with a given name above and attempting to retrieve its ifindex based
+	 * on that name. Someone (ie udev) could have the iface renamed in
+	 * between here. It's a pity that TUNSETIFF doesn't copy back to us the
+	 * newly allocated ifindex as it does with ifname)
+	 */
+	tun->ifindex = if_nametoindex(tun->devname);
+	if (tun->ifindex == 0) {
+		LOGTUN(tun, LOGL_ERROR, "Unable to find ifindex for dev %s\n",
+		       tun->devname);
    	goto err_close;
    }
-	rc = rtnl_link_get_kernel(tun->nl, 0, tun->devname, &link);
-	if (rc < 0) {
-		LOGTUN(tun, LOGL_ERROR, "Cannot get ifindex for netif after create?!?\n");
-		goto err_free_nl;
-	}
-	tun->ifindex = rtnl_link_get_ifindex(link);
-	rtnl_link_put(link);
-
    /* switch back to default namespace before creating new thread */
-	if (tun->netns_name)
+	if (inside_netns) {
    	OSMO_ASSERT(osmo_netns_switch_exit(&switch_state) == 0);
+		inside_netns = false;
+	}
+
+	tun->netdev = osmo_netdev_alloc(tun, tun->devname);
+	if (tun->netns_name) {
+		rc = osmo_netdev_set_netns_name(tun->netdev, tun->netns_name);
+		if (rc < 0)
+			goto err_free_netdev;
+	}
+	rc = osmo_netdev_set_ifindex(tun->netdev, tun->ifindex);
+	if (rc < 0)
+		goto err_free_netdev;
+
+	rc = osmo_netdev_register(tun->netdev);
+	if (rc < 0)
+		goto err_free_netdev;
/* bring the network device up */
-	rc = netdev_set_link(tun->nl, tun->ifindex, true);
+	rc = osmo_netdev_ifupdown(tun->netdev, true);
    if (rc < 0)
    	LOGTUN(tun, LOGL_ERROR, "Cannot set interface to 'up'\n");
if (tun->netns_name) {
-		rc = netdev_add_defaultroute(tun->nl, tun->ifindex, AF_INET);
+		struct osmo_sockaddr osa;
+
+		memset(&osa, 0, sizeof(osa));
+		osa.u.sin.sin_family = AF_INET;
+		osa.u.sin.sin_addr.s_addr = 0;
+		rc = osmo_netdev_add_route(tun->netdev, &osa, 0, NULL);
    	if (rc < 0)
    		LOGTUN(tun, LOGL_ERROR, "Cannot add IPv4 default route "
-						"(rc=%d): %s\n", rc, nl_geterror(rc));
+						"(rc=%d): %s\n", rc, strerror(-rc));
    	else
    		LOGTUN(tun, LOGL_INFO, "Added IPv4 default route\n");
-		rc = netdev_add_defaultroute(tun->nl, tun->ifindex, AF_INET6);
+		memset(&osa, 0, sizeof(osa));
+		osa.u.sin6.sin6_family = AF_INET6;
+		memset(&osa.u.sin6.sin6_addr, 0, sizeof(osa.u.sin6.sin6_addr));
+		rc = osmo_netdev_add_route(tun->netdev, &osa, 0, NULL);
    	if (rc < 0)
    		LOGTUN(tun, LOGL_ERROR, "Cannot add IPv6 default route "
-						"(rc=%d): %s\n", rc, nl_geterror(rc));
+						"(rc=%d): %s\n", rc, strerror(-rc));
    	else
    		LOGTUN(tun, LOGL_INFO, "Added IPv6 default route\n");
    }
if (pthread_create(&tun->thread, NULL, tun_device_thread, tun)) {
    	LOGTUN(tun, LOGL_ERROR, "Cannot create TUN thread: %s\n", strerror(errno));
-		goto err_free_nl;
+		goto err_free_netdev;
    }
LOGTUN(tun, LOGL_INFO, "Created (in netns '%s')\n", tun->netns_name);
@@ -407,12 +427,12 @@
return tun;
-err_free_nl:
-	nl_socket_free(tun->nl);
+err_free_netdev:
+	osmo_netdev_free(tun->netdev);
 err_close:
    close(tun->fd);
 err_restore_ns:
-	if (tun->netns_name)
+	if (inside_netns)
    	OSMO_ASSERT(osmo_netns_switch_exit(&switch_state) == 0);
 err_close_ns:
    if (tun->netns_name)
@@ -482,7 +502,7 @@
    if (tun->netns_name)
    	close(tun->netns_fd);
    close(tun->fd);
-	nl_socket_free(tun->nl);
+	osmo_netdev_free(tun->netdev);
    talloc_free(tun);
 }
-- 
To view, visit https://gerrit.osmocom.org/c/osmo-uecups/+/42444?usp=email
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Gerrit-MessageType: merged
Gerrit-Project: osmo-uecups
Gerrit-Branch: master
Gerrit-Change-Id: I8f18ef56a6e7186fed88f965fbb34aa390c3bac1
Gerrit-Change-Number: 42444
Gerrit-PatchSet: 4
Gerrit-Owner: pespin pespin@sysmocom.de
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: daniel dwillmann@sysmocom.de
Gerrit-Reviewer: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: laforge laforge@osmocom.org
Gerrit-Reviewer: lynxis lazus lynxis@fe80.eu
Gerrit-Reviewer: osmith osmith@sysmocom.de
Gerrit-Reviewer: pespin pespin@sysmocom.de



    

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[L] Change in osmo-uecups[master]: Use libosmocore netdev API