Adding upstream version 252.22.upstream/252.22

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 261 insertions, 0 deletions

diff --git a/src/network/netdev/tuntap.c b/src/network/netdev/tuntap.c
new file mode 100644
index 0000000..10c93be
--- /dev/null
+++ b/src/network/netdev/tuntap.c
@@ -0,0 +1,261 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <net/if.h>
+#include <netinet/if_ether.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <linux/if_tun.h>
+
+#include "alloc-util.h"
+#include "daemon-util.h"
+#include "fd-util.h"
+#include "networkd-link.h"
+#include "networkd-manager.h"
+#include "socket-util.h"
+#include "tuntap.h"
+#include "user-util.h"
+
+#define TUN_DEV "/dev/net/tun"
+
+static TunTap* TUNTAP(NetDev *netdev) {
+        assert(netdev);
+
+        switch (netdev->kind) {
+        case NETDEV_KIND_TAP:
+                return TAP(netdev);
+        case NETDEV_KIND_TUN:
+                return TUN(netdev);
+        default:
+                return NULL;
+        }
+}
+
+static void *close_fd_ptr(void *p) {
+        safe_close(PTR_TO_FD(p));
+        return NULL;
+}
+
+DEFINE_PRIVATE_HASH_OPS_FULL(named_fd_hash_ops, char, string_hash_func, string_compare_func, free, void, close_fd_ptr);
+
+int manager_add_tuntap_fd(Manager *m, int fd, const char *name) {
+        _cleanup_free_ char *tuntap_name = NULL;
+        const char *p;
+        int r;
+
+        assert(m);
+        assert(fd >= 0);
+        assert(name);
+
+        p = startswith(name, "tuntap-");
+        if (!p)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Received unknown fd (%s).", name);
+
+        if (!ifname_valid(p))
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Received tuntap fd with invalid name (%s).", p);
+
+        tuntap_name = strdup(p);
+        if (!tuntap_name)
+                return log_oom_debug();
+
+        r = hashmap_ensure_put(&m->tuntap_fds_by_name, &named_fd_hash_ops, tuntap_name, FD_TO_PTR(fd));
+        if (r < 0)
+                return log_debug_errno(r, "Failed to store tuntap fd: %m");
+
+        TAKE_PTR(tuntap_name);
+        return 0;
+}
+
+void manager_clear_unmanaged_tuntap_fds(Manager *m) {
+        char *name;
+        void *p;
+
+        assert(m);
+
+        while ((p = hashmap_steal_first_key_and_value(m->tuntap_fds_by_name, (void**) &name))) {
+                close_and_notify_warn(PTR_TO_FD(p), name);
+                name = mfree(name);
+        }
+}
+
+static int tuntap_take_fd(NetDev *netdev) {
+        _cleanup_free_ char *name = NULL;
+        void *p;
+        int r;
+
+        assert(netdev);
+        assert(netdev->manager);
+
+        r = link_get_by_name(netdev->manager, netdev->ifname, NULL);
+        if (r < 0)
+                return r;
+
+        p = hashmap_remove2(netdev->manager->tuntap_fds_by_name, netdev->ifname, (void**) &name);
+        if (!p)
+                return -ENOENT;
+
+        log_netdev_debug(netdev, "Found file descriptor in fd store.");
+        return PTR_TO_FD(p);
+}
+
+static int netdev_create_tuntap(NetDev *netdev) {
+        _cleanup_close_ int fd = -1;
+        struct ifreq ifr = {};
+        TunTap *t;
+        int r;
+
+        assert(netdev);
+        t = TUNTAP(netdev);
+        assert(t);
+
+        fd = TAKE_FD(t->fd);
+        if (fd < 0)
+                fd = tuntap_take_fd(netdev);
+        if (fd < 0)
+                fd = open(TUN_DEV, O_RDWR|O_CLOEXEC);
+        if (fd < 0)
+                return log_netdev_error_errno(netdev, errno,  "Failed to open " TUN_DEV ": %m");
+
+        if (netdev->kind == NETDEV_KIND_TAP)
+                ifr.ifr_flags |= IFF_TAP;
+        else
+                ifr.ifr_flags |= IFF_TUN;
+
+        if (!t->packet_info)
+                ifr.ifr_flags |= IFF_NO_PI;
+
+        if (t->multi_queue)
+                ifr.ifr_flags |= IFF_MULTI_QUEUE;
+
+        if (t->vnet_hdr)
+                ifr.ifr_flags |= IFF_VNET_HDR;
+
+        strncpy(ifr.ifr_name, netdev->ifname, IFNAMSIZ-1);
+
+        if (ioctl(fd, TUNSETIFF, &ifr) < 0)
+                return log_netdev_error_errno(netdev, errno, "TUNSETIFF failed: %m");
+
+        if (t->multi_queue) {
+                /* If we don't detach the queue, the kernel will send packets to our queue and they
+                 * will be dropped because we never read them, which is especially important in case
+                 * of KeepCarrier option which persists open FD. So detach our queue right after
+                 * device create/attach to make kernel not send the packets to it. The option is
+                 * available for multi-queue devices only.
+                 *
+                 * See https://github.com/systemd/systemd/pull/30504 for details. */
+                struct ifreq detach_request = { .ifr_flags = IFF_DETACH_QUEUE };
+                if (ioctl(fd, TUNSETQUEUE, &detach_request) < 0)
+                        return log_netdev_error_errno(netdev, errno, "TUNSETQUEUE failed: %m");
+        }
+
+        if (t->user_name) {
+                const char *user = t->user_name;
+                uid_t uid;
+
+                r = get_user_creds(&user, &uid, NULL, NULL, NULL, USER_CREDS_ALLOW_MISSING);
+                if (r < 0)
+                        return log_netdev_error_errno(netdev, r, "Cannot resolve user name %s: %m", t->user_name);
+
+                if (ioctl(fd, TUNSETOWNER, uid) < 0)
+                        return log_netdev_error_errno(netdev, errno, "TUNSETOWNER failed: %m");
+        }
+
+        if (t->group_name) {
+                const char *group = t->group_name;
+                gid_t gid;
+
+                r = get_group_creds(&group, &gid, USER_CREDS_ALLOW_MISSING);
+                if (r < 0)
+                        return log_netdev_error_errno(netdev, r, "Cannot resolve group name %s: %m", t->group_name);
+
+                if (ioctl(fd, TUNSETGROUP, gid) < 0)
+                        return log_netdev_error_errno(netdev, errno, "TUNSETGROUP failed: %m");
+
+        }
+
+        if (ioctl(fd, TUNSETPERSIST, 1) < 0)
+                return log_netdev_error_errno(netdev, errno, "TUNSETPERSIST failed: %m");
+
+        if (t->keep_fd) {
+                t->fd = TAKE_FD(fd);
+                (void) notify_push_fdf(t->fd, "tuntap-%s", netdev->ifname);
+        }
+
+        return 0;
+}
+
+static void tuntap_init(NetDev *netdev) {
+        TunTap *t;
+
+        assert(netdev);
+        t = TUNTAP(netdev);
+        assert(t);
+
+        t->fd = -1;
+}
+
+static void tuntap_drop(NetDev *netdev) {
+        TunTap *t;
+
+        assert(netdev);
+        t = TUNTAP(netdev);
+        assert(t);
+
+        t->fd = close_and_notify_warn(t->fd, netdev->ifname);
+}
+
+static void tuntap_done(NetDev *netdev) {
+        TunTap *t;
+
+        assert(netdev);
+        t = TUNTAP(netdev);
+        assert(t);
+
+        t->fd = safe_close(t->fd);
+        t->user_name = mfree(t->user_name);
+        t->group_name = mfree(t->group_name);
+}
+
+static int tuntap_verify(NetDev *netdev, const char *filename) {
+        assert(netdev);
+
+        if (netdev->mtu != 0)
+                log_netdev_warning(netdev,
+                                   "MTUBytes= configured for %s device in %s will be ignored.\n"
+                                   "Please set it in the corresponding .network file.",
+                                   netdev_kind_to_string(netdev->kind), filename);
+
+        if (netdev->hw_addr.length > 0)
+                log_netdev_warning(netdev,
+                                   "MACAddress= configured for %s device in %s will be ignored.\n"
+                                   "Please set it in the corresponding .network file.",
+                                   netdev_kind_to_string(netdev->kind), filename);
+
+        return 0;
+}
+
+const NetDevVTable tun_vtable = {
+        .object_size = sizeof(TunTap),
+        .sections = NETDEV_COMMON_SECTIONS "Tun\0",
+        .config_verify = tuntap_verify,
+        .init = tuntap_init,
+        .drop = tuntap_drop,
+        .done = tuntap_done,
+        .create = netdev_create_tuntap,
+        .create_type = NETDEV_CREATE_INDEPENDENT,
+        .iftype = ARPHRD_NONE,
+};
+
+const NetDevVTable tap_vtable = {
+        .object_size = sizeof(TunTap),
+        .sections = NETDEV_COMMON_SECTIONS "Tap\0",
+        .config_verify = tuntap_verify,
+        .init = tuntap_init,
+        .drop = tuntap_drop,
+        .done = tuntap_done,
+        .create = netdev_create_tuntap,
+        .create_type = NETDEV_CREATE_INDEPENDENT,
+        .iftype = ARPHRD_ETHER,
+};