[PATCH v5 bpf-next 03/11] net: Add XDP setup and query commands for Tx programs

[David Ahern]

From: David Ahern <dah...@digitalocean.com>

Add new netdev commands, XDP_SETUP_PROG_EGRESS and
XDP_QUERY_PROG_EGRESS, to query and setup egress programs.

Update dev_change_xdp_fd and dev_xdp_install to check for egress mode
via XDP_FLAGS_EGRESS_MODE in the flags. If egress bool is set, then use
XDP_SETUP_PROG_EGRESS in dev_xdp_install and XDP_QUERY_PROG_EGRESS in
dev_change_xdp_fd.

Signed-off-by: David Ahern <dah...@digitalocean.com>
Co-developed-by: Prashant Bhole <prashantbhole.li...@gmail.com>
Signed-off-by: Prashant Bhole <prashantbhole.li...@gmail.com>
---
 include/linux/netdevice.h |  2 ++
 net/core/dev.c            | 20 +++++++++++++++-----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 594c13d4cd00..ee0cb73ca18a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -873,8 +873,10 @@ enum bpf_netdev_command {
         */
        XDP_SETUP_PROG,
        XDP_SETUP_PROG_HW,
+       XDP_SETUP_PROG_EGRESS,
        XDP_QUERY_PROG,
        XDP_QUERY_PROG_HW,
+       XDP_QUERY_PROG_EGRESS,
        /* BPF program for offload callbacks, invoked at program load time. */
        BPF_OFFLOAD_MAP_ALLOC,
        BPF_OFFLOAD_MAP_FREE,
diff --git a/net/core/dev.c b/net/core/dev.c
index afff16849c26..c0455e764f97 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8600,13 +8600,16 @@ static int dev_xdp_install(struct net_device *dev, 
bpf_op_t bpf_op,
                           struct bpf_prog *prog)
 {
        bool non_hw = !(flags & XDP_FLAGS_HW_MODE);
+       bool egress = flags & XDP_FLAGS_EGRESS_MODE;
        struct bpf_prog *prev_prog = NULL;
        struct netdev_bpf xdp;
        int err;
 
        if (non_hw) {
-               prev_prog = bpf_prog_by_id(__dev_xdp_query(dev, bpf_op,
-                                                          XDP_QUERY_PROG));
+               enum bpf_netdev_command cmd;
+
+               cmd = egress ? XDP_QUERY_PROG_EGRESS : XDP_QUERY_PROG;
+               prev_prog = bpf_prog_by_id(__dev_xdp_query(dev, bpf_op, cmd));
                if (IS_ERR(prev_prog))
                        prev_prog = NULL;
        }
@@ -8615,7 +8618,7 @@ static int dev_xdp_install(struct net_device *dev, 
bpf_op_t bpf_op,
        if (flags & XDP_FLAGS_HW_MODE)
                xdp.command = XDP_SETUP_PROG_HW;
        else
-               xdp.command = XDP_SETUP_PROG;
+               xdp.command = egress ? XDP_SETUP_PROG_EGRESS : XDP_SETUP_PROG;
        xdp.extack = extack;
        xdp.flags = flags;
        xdp.prog = prog;
@@ -8677,12 +8680,18 @@ int dev_change_xdp_fd(struct net_device *dev, struct 
netlink_ext_ack *extack,
        bpf_op_t bpf_op, bpf_chk;
        struct bpf_prog *prog;
        bool offload;
+       bool egress;
        int err;
 
        ASSERT_RTNL();
 
        offload = flags & XDP_FLAGS_HW_MODE;
-       query = offload ? XDP_QUERY_PROG_HW : XDP_QUERY_PROG;
+       egress = flags & XDP_FLAGS_EGRESS_MODE;
+       if (egress)
+               query = XDP_QUERY_PROG_EGRESS;
+       else
+               query = offload ? XDP_QUERY_PROG_HW : XDP_QUERY_PROG;
+
 
        bpf_op = bpf_chk = ops->ndo_bpf;
        if (!bpf_op && (flags & (XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE))) {
@@ -8712,7 +8721,8 @@ int dev_change_xdp_fd(struct net_device *dev, struct 
netlink_ext_ack *extack,
                }
        }
        if (fd >= 0) {
-               if (!offload && __dev_xdp_query(dev, bpf_chk, XDP_QUERY_PROG)) {
+               if (!offload && !egress &&
+                   __dev_xdp_query(dev, bpf_chk, XDP_QUERY_PROG)) {
                        NL_SET_ERR_MSG(extack, "native and generic XDP can't be 
active at the same time");
                        return -EEXIST;
                }
-- 
2.21.1 (Apple Git-122.3)