tap: Add check for USO features

Tap indicates support for USO features according to
capabilities of current kernel module.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Signed-off-by: Andrew Melnychecnko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

include/net/net.h

@@ -54,6 +54,7 @@ typedef void (LinkStatusChanged)(NetClientState *);
 typedef void (NetClientDestructor)(NetClientState *);
 typedef RxFilterInfo *(QueryRxFilter)(NetClientState *);
 typedef bool (HasUfo)(NetClientState *);
+typedef bool (HasUso)(NetClientState *);
 typedef bool (HasVnetHdr)(NetClientState *);
 typedef bool (HasVnetHdrLen)(NetClientState *, int);
 typedef bool (GetUsingVnetHdr)(NetClientState *);
@@ -84,6 +85,7 @@ typedef struct NetClientInfo {
     QueryRxFilter *query_rx_filter;
     NetPoll *poll;
     HasUfo *has_ufo;
+    HasUso *has_uso;
     HasVnetHdr *has_vnet_hdr;
     HasVnetHdrLen *has_vnet_hdr_len;
     GetUsingVnetHdr *get_using_vnet_hdr;
@@ -187,6 +189,7 @@ void qemu_set_info_str(NetClientState *nc,
                        const char *fmt, ...) G_GNUC_PRINTF(2, 3);
 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6]);
 bool qemu_has_ufo(NetClientState *nc);
+bool qemu_has_uso(NetClientState *nc);
 bool qemu_has_vnet_hdr(NetClientState *nc);
 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len);
 bool qemu_get_using_vnet_hdr(NetClientState *nc);

net/net.c

@@ -495,6 +495,15 @@ bool qemu_has_ufo(NetClientState *nc)
     return nc->info->has_ufo(nc);
 }
 
+bool qemu_has_uso(NetClientState *nc)
+{
+    if (!nc || !nc->info->has_uso) {
+        return false;
+    }
+
+    return nc->info->has_uso(nc);
+}
+
 bool qemu_has_vnet_hdr(NetClientState *nc)
 {
     if (!nc || !nc->info->has_vnet_hdr) {

net/tap-bsd.c

@@ -212,6 +212,11 @@ int tap_probe_has_ufo(int fd)
     return 0;
 }
 
+int tap_probe_has_uso(int fd)
+{
+    return 0;
+}
+
 int tap_probe_vnet_hdr_len(int fd, int len)
 {
     return 0;

net/tap-linux.c

@@ -173,6 +173,18 @@ int tap_probe_has_ufo(int fd)
     return 1;
 }
 
+int tap_probe_has_uso(int fd)
+{
+    unsigned offload;
+
+    offload = TUN_F_CSUM | TUN_F_USO4 | TUN_F_USO6;
+
+    if (ioctl(fd, TUNSETOFFLOAD, offload) < 0) {
+        return 0;
+    }
+    return 1;
+}
+
 /* Verify that we can assign given length */
 int tap_probe_vnet_hdr_len(int fd, int len)
 {

net/tap-solaris.c

@@ -216,6 +216,11 @@ int tap_probe_has_ufo(int fd)
     return 0;
 }
 
+int tap_probe_has_uso(int fd)
+{
+    return 0;
+}
+
 int tap_probe_vnet_hdr_len(int fd, int len)
 {
     return 0;

net/tap-stub.c

@@ -47,6 +47,11 @@ int tap_probe_has_ufo(int fd)
     return 0;
 }
 
+int tap_probe_has_uso(int fd)
+{
+    return 0;
+}
+
 int tap_probe_vnet_hdr_len(int fd, int len)
 {
     return 0;

net/tap.c

@@ -57,6 +57,7 @@ typedef struct TAPState {
     bool write_poll;
     bool using_vnet_hdr;
     bool has_ufo;
+    bool has_uso;
     bool enabled;
     VHostNetState *vhost_net;
     unsigned host_vnet_hdr_len;
@@ -237,6 +238,15 @@ static bool tap_has_ufo(NetClientState *nc)
     return s->has_ufo;
 }
 
+static bool tap_has_uso(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
+
+    return s->has_uso;
+}
+
 static bool tap_has_vnet_hdr(NetClientState *nc)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
@@ -384,6 +394,7 @@ static NetClientInfo net_tap_info = {
     .poll = tap_poll,
     .cleanup = tap_cleanup,
     .has_ufo = tap_has_ufo,
+    .has_uso = tap_has_uso,
     .has_vnet_hdr = tap_has_vnet_hdr,
     .has_vnet_hdr_len = tap_has_vnet_hdr_len,
     .get_using_vnet_hdr = tap_get_using_vnet_hdr,
@@ -413,6 +424,7 @@ static TAPState *net_tap_fd_init(NetClientState *peer,
     s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
     s->using_vnet_hdr = false;
     s->has_ufo = tap_probe_has_ufo(s->fd);
+    s->has_uso = tap_probe_has_uso(s->fd);
     s->enabled = true;
     tap_set_offload(&s->nc, 0, 0, 0, 0, 0, 0, 0);
     /*

net/tap_int.h

@@ -37,6 +37,7 @@ void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp);
 int tap_probe_vnet_hdr(int fd, Error **errp);
 int tap_probe_vnet_hdr_len(int fd, int len);
 int tap_probe_has_ufo(int fd);
+int tap_probe_has_uso(int fd);
 void tap_fd_set_offload(int fd, int csum, int tso4, int tso6, int ecn, int ufo,
                         int uso4, int uso6);
 void tap_fd_set_vnet_hdr_len(int fd, int len);