[Qemu-devel] [RFC 2/6] tap: Add support for bpf ioctls

[Sameeh Jubran <sameeh@daynix.com>]

From: Sameeh Jubran <sjubran@redhat.com>

Starting from kernel v4.16 tun device supports TUNSETSTEERINGEBPF and
TUNSETFILTEREBPF.

Signed-off-by: Sameeh Jubran <sjubran@redhat.com>
---
 include/net/net.h |  3 ++-
 net/tap-bsd.c     |  5 +++++
 net/tap-linux.c   | 29 ++++++++++++++++++++++++++++-
 net/tap-linux.h   |  3 ++-
 net/tap-solaris.c |  5 +++++
 net/tap-stub.c    |  5 +++++
 net/tap.c         |  8 ++++++++
 net/tap_int.h     |  1 +
 qapi/net.json     | 11 +++++++++++
 9 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/include/net/net.h b/include/net/net.h
index 1425960f76..e7d1baac10 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -39,7 +39,6 @@ typedef struct NICConf {
     DEFINE_PROP_MACADDR("mac",   _state, _conf.macaddr),                \
     DEFINE_PROP_NETDEV("netdev", _state, _conf.peers)
 
-
 /* Net clients */
 
 typedef void (NetPoll)(NetClientState *, bool enable);
@@ -60,6 +59,7 @@ typedef int (SetVnetLE)(NetClientState *, bool);
 typedef int (SetVnetBE)(NetClientState *, bool);
 typedef struct SocketReadState SocketReadState;
 typedef void (SocketReadStateFinalize)(SocketReadState *rs);
+typedef int (SetBPFFilter)(NetClientState *, int, BPFType);
 
 typedef struct NetClientInfo {
     NetClientDriver type;
@@ -80,6 +80,7 @@ typedef struct NetClientInfo {
     SetVnetHdrLen *set_vnet_hdr_len;
     SetVnetLE *set_vnet_le;
     SetVnetBE *set_vnet_be;
+    SetBPFFilter *set_bpf_filter;
 } NetClientInfo;
 
 struct NetClientState {
diff --git a/net/tap-bsd.c b/net/tap-bsd.c
index 6c9692263d..fccf17bad0 100644
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -259,3 +259,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
 {
     return -1;
 }
+
+int tap_fd_load_bpf(int fd, int bpf_fd, BPFType type)
+{
+    return -1;
+}
diff --git a/net/tap-linux.c b/net/tap-linux.c
index 535b1ddb61..e8ee54f3b3 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -305,7 +305,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
 {
     struct ifreq ifr;
 
-    if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
+    if (ioctl(fd, TUNGETIFF, &ifr) != 0)
+    {
         error_report("TUNGETIFF ioctl() failed: %s",
                      strerror(errno));
         return -1;
@@ -314,3 +315,29 @@ int tap_fd_get_ifname(int fd, char *ifname)
     pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name);
     return 0;
 }
+
+
+int tap_fd_load_bpf(int fd, int bpf_fd, BPFType type)
+{
+    int ioctl_num = 0;
+    switch (type)
+    {
+        case BPF_TYPE_FILTER:
+        ioctl_num = TUNSETFILTEREBPF;
+        break;
+
+        case BPF_TYPE_STEERING:
+        ioctl_num = TUNSETSTEERINGEBPF;
+        break;
+
+        default:
+        error_report("Unknown bpf_type");
+        return -1;
+    }
+
+    if (ioctl(fd, ioctl_num, &bpf_fd) != 0) {
+        error_report("#%d ioctl() failed: %s", ioctl_num, strerror(errno));
+        return -1;
+    }
+    return 0;
+}
diff --git a/net/tap-linux.h b/net/tap-linux.h
index 2f36d100fc..7348169fc2 100644
--- a/net/tap-linux.h
+++ b/net/tap-linux.h
@@ -31,7 +31,8 @@
 #define TUNSETQUEUE  _IOW('T', 217, int)
 #define TUNSETVNETLE _IOW('T', 220, int)
 #define TUNSETVNETBE _IOW('T', 222, int)
-
+#define TUNSETSTEERINGEBPF _IOR('T', 224, int)
+#define TUNSETFILTEREBPF _IOR('T', 225, int)
 #endif
 
 /* TUNSETIFF ifr flags */
diff --git a/net/tap-solaris.c b/net/tap-solaris.c
index a2a92356c1..a5a6248c7d 100644
--- a/net/tap-solaris.c
+++ b/net/tap-solaris.c
@@ -254,3 +254,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
 {
     return -1;
 }
+
+int tap_fd_load_bpf(int fd, int bpf_fd, BPFType type)
+{
+    return -1;
+}
diff --git a/net/tap-stub.c b/net/tap-stub.c
index a9ab8f8293..d059a32435 100644
--- a/net/tap-stub.c
+++ b/net/tap-stub.c
@@ -85,3 +85,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
 {
     return -1;
 }
+
+int tap_fd_load_bpf(int fd, int bpf_fd, BPFType type)
+{
+    return -1;
+}
diff --git a/net/tap.c b/net/tap.c
index 2126f4882d..ee98fecd40 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -342,6 +342,13 @@ int tap_get_fd(NetClientState *nc)
     return s->fd;
 }
 
+static int tap_set_bpf_filter(NetClientState *nc, int bpf_fd, BPFType type)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
+    return tap_fd_load_bpf(s->fd, bpf_fd, type);
+}
+
 /* fd support */
 
 static NetClientInfo net_tap_info = {
@@ -360,6 +367,7 @@ static NetClientInfo net_tap_info = {
     .set_vnet_hdr_len = tap_set_vnet_hdr_len,
     .set_vnet_le = tap_set_vnet_le,
     .set_vnet_be = tap_set_vnet_be,
+    .set_bpf_filter = tap_set_bpf_filter,
 };
 
 static TAPState *net_tap_fd_init(NetClientState *peer,
diff --git a/net/tap_int.h b/net/tap_int.h
index 9f931d52d6..3e1603a88e 100644
--- a/net/tap_int.h
+++ b/net/tap_int.h
@@ -45,5 +45,6 @@ int tap_fd_set_vnet_be(int fd, int vnet_is_be);
 int tap_fd_enable(int fd);
 int tap_fd_disable(int fd);
 int tap_fd_get_ifname(int fd, char *ifname);
+int tap_fd_load_bpf(int fd, int bpf_fd, BPFType type);
 
 #endif /* NET_TAP_INT_H */
diff --git a/qapi/net.json b/qapi/net.json
index 6b7d93cb59..ce0a688444 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -692,3 +692,14 @@
 ##
 { 'event': 'NIC_RX_FILTER_CHANGED',
   'data': { '*name': 'str', 'path': 'str' } }
+
+##
+# @BPFType:
+#
+# BPF programs types provided as an argument for tap bpf ioctls
+#
+# Since: 2.12
+#
+##
+{ 'enum': 'BPFType',
+  'data': [ 'filter', 'steering' ] }
-- 
2.13.6