tap: add APIs for vnet header length

Add APIs to control host header length. First user
will be vhost-net.

Signed-off-by: Michael S. Tsirkin <[email protected]>

diff --git a/net/tap-aix.c b/net/tap-aix.c
index 4bc9f2f6d222d9d98a21a2ad4073d6550e443cd4..e19aaba110e420eb138dd5db2fe02e64eed62d95 100644 (file)
--- a/net/tap-aix.c
+++ b/net/tap-aix.c
@@ -46,6 +46,15 @@ int tap_probe_has_ufo(int fd)
     return 0;
 }
 
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
 void tap_fd_set_offload(int fd, int csum, int tso4,
                         int tso6, int ecn, int ufo)
 {

diff --git a/net/tap-bsd.c b/net/tap-bsd.c
index 3773d5da5e6b6e156f470944ee2b3f7df00da03f..3513075337f98cbb15427499630ff9d7a7e727f4 100644 (file)
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -116,6 +116,15 @@ int tap_probe_has_ufo(int fd)
     return 0;
 }
 
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
 void tap_fd_set_offload(int fd, int csum, int tso4,
                         int tso6, int ecn, int ufo)
 {

diff --git a/net/tap-linux.c b/net/tap-linux.c
index c92983cb5386be156ffea1faaf213aad209f8393..f7aa9041b81fd0abd309b1e3440cccb7da2967d1 100644 (file)
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -129,6 +129,35 @@ int tap_probe_has_ufo(int fd)
     return 1;
 }
 
+/* Verify that we can assign given length */
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    int orig;
+    if (ioctl(fd, TUNGETVNETHDRSZ, &orig) == -1) {
+        return 0;
+    }
+    if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
+        return 0;
+    }
+    /* Restore original length: we can't handle failure. */
+    if (ioctl(fd, TUNSETVNETHDRSZ, &orig) == -1) {
+        fprintf(stderr, "TUNGETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
+                strerror(errno));
+        assert(0);
+        return -errno;
+    }
+    return 1;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+    if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
+        fprintf(stderr, "TUNSETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
+                strerror(errno));
+        assert(0);
+    }
+}
+
 void tap_fd_set_offload(int fd, int csum, int tso4,
                         int tso6, int ecn, int ufo)
 {

diff --git a/net/tap-linux.h b/net/tap-linux.h
index 727fcf50101fa748612d5b951e41aa765d6da9a5..659e98122b53166db09071bb36b92b68e8671c05 100644 (file)
--- a/net/tap-linux.h
+++ b/net/tap-linux.h
@@ -27,6 +27,8 @@
 #define TUNSETOFFLOAD  _IOW('T', 208, unsigned int)
 #define TUNGETIFF      _IOR('T', 210, unsigned int)
 #define TUNSETSNDBUF   _IOW('T', 212, int)
+#define TUNGETVNETHDRSZ _IOR('T', 215, int)
+#define TUNSETVNETHDRSZ _IOW('T', 216, int)
 
 #endif
 

diff --git a/net/tap-solaris.c b/net/tap-solaris.c
index 4ac61d2ad6250dd295b66ff31bc86a5479b1ff9b..c216d282676113108ce7cf2f103cbd33dba7fe10 100644 (file)
--- a/net/tap-solaris.c
+++ b/net/tap-solaris.c
@@ -212,6 +212,15 @@ int tap_probe_has_ufo(int fd)
     return 0;
 }
 
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
 void tap_fd_set_offload(int fd, int csum, int tso4,
                         int tso6, int ecn, int ufo)
 {

diff --git a/net/tap-win32.c b/net/tap-win32.c
index 74348daf5a6438f689117b2c352ae0e4e4c2aed0..9fe4fcd5f48d148af946846496ec6843bad3fb28 100644 (file)
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -728,6 +728,15 @@ int tap_has_vnet_hdr(VLANClientState *vc)
     return 0;
 }
 
+int tap_probe_vnet_hdr_len(int fd, int len)
+{
+    return 0;
+}
+
+void tap_fd_set_vnet_hdr_len(int fd, int len)
+{
+}
+
 void tap_using_vnet_hdr(VLANClientState *vc, int using_vnet_hdr)
 {
 }

diff --git a/net/tap.c b/net/tap.c
index 2866ff40e83c5112d28ec1c4d94abc7e1a325f77..4afb314fde032bdd7ee15fa07047c8f7e4684438 100644 (file)
--- a/net/tap.c
+++ b/net/tap.c
@@ -232,6 +232,27 @@ int tap_has_vnet_hdr(VLANClientState *nc)
     return !!s->host_vnet_hdr_len;
 }
 
+int tap_has_vnet_hdr_len(VLANClientState *nc, int len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_TYPE_TAP);
+
+    return tap_probe_vnet_hdr_len(s->fd, len);
+}
+
+void tap_set_vnet_hdr_len(VLANClientState *nc, int len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_TYPE_TAP);
+    assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) ||
+           len == sizeof(struct virtio_net_hdr));
+
+    tap_fd_set_vnet_hdr_len(s->fd, len);
+    s->host_vnet_hdr_len = len;
+}
+
 void tap_using_vnet_hdr(VLANClientState *nc, int using_vnet_hdr)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);

diff --git a/net/tap.h b/net/tap.h
index b8cec8320c551132a5ae24eab2459532a71f4f12..e44bd2bc5f8f1b116fb3f43b7f255421490ac509 100644 (file)
--- a/net/tap.h
+++ b/net/tap.h
@@ -40,13 +40,17 @@ ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen);
 
 int tap_has_ufo(VLANClientState *vc);
 int tap_has_vnet_hdr(VLANClientState *vc);
+int tap_has_vnet_hdr_len(VLANClientState *vc, int len);
 void tap_using_vnet_hdr(VLANClientState *vc, int using_vnet_hdr);
 void tap_set_offload(VLANClientState *vc, int csum, int tso4, int tso6, int ecn, int ufo);
+void tap_set_vnet_hdr_len(VLANClientState *vc, int len);
 
 int tap_set_sndbuf(int fd, QemuOpts *opts);
 int tap_probe_vnet_hdr(int fd);
+int tap_probe_vnet_hdr_len(int fd, int len);
 int tap_probe_has_ufo(int fd);
 void tap_fd_set_offload(int fd, int csum, int tso4, int tso6, int ecn, int ufo);
+void tap_fd_set_vnet_hdr_len(int fd, int len);
 
 int tap_get_fd(VLANClientState *vc);