xdp: factor out common program/flags handling from drivers

Basic operations drivers perform during xdp setup and query can
be moved to helpers in the core.  Encapsulate program and flags
into a structure and add helpers.  Note that the structure is
intended as the "main" program information source in the driver.
Most drivers will additionally place the program pointer in their
fast path or ring structures.

The helpers don't have a huge impact now, but they will
decrease the code duplication when programs can be installed
in HW and driver at the same time.  Encapsulating the basic
operations in helpers will hopefully also reduce the number
of changes to drivers which adopt them.

Helpers could really be static inline, but they depend on
definition of struct netdev_bpf which means they'd have
to be placed in netdevice.h, an already 4500 line header.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index 2a71a9ffd095a87e19c4546fc0838dafd7cbb28e..2021dda595b725e8fd26ac8f32b0a59af662907b 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -553,8 +553,7 @@ struct nfp_net_dp {
  * @rss_cfg:            RSS configuration
  * @rss_key:            RSS secret key
  * @rss_itbl:           RSS indirection table
- * @xdp_flags:         Flags with which XDP prog was loaded
- * @xdp_prog:          XDP prog (for ctrl path, both DRV and HW modes)
+ * @xdp:               Information about the attached XDP program
  * @max_r_vecs:                Number of allocated interrupt vectors for RX/TX
  * @max_tx_rings:       Maximum number of TX rings supported by the Firmware
  * @max_rx_rings:       Maximum number of RX rings supported by the Firmware
@@ -610,8 +609,7 @@ struct nfp_net {
        u8 rss_key[NFP_NET_CFG_RSS_KEY_SZ];
        u8 rss_itbl[NFP_NET_CFG_RSS_ITBL_SZ];
 
-       u32 xdp_flags;
-       struct bpf_prog *xdp_prog;
+       struct xdp_attachment_info xdp;
 
        unsigned int max_tx_rings;
        unsigned int max_rx_rings;

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index d207145986137aa17968c9bda56bee71f5ce03fe..4bb589dbffbcce07e0e0afb58577e1db5fd3d9da 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -3417,34 +3417,29 @@ nfp_net_xdp_setup_drv(struct nfp_net *nn, struct bpf_prog *prog,
        return nfp_net_ring_reconfig(nn, dp, extack);
 }
 
-static int
-nfp_net_xdp_setup(struct nfp_net *nn, struct bpf_prog *prog, u32 flags,
-                 struct netlink_ext_ack *extack)
+static int nfp_net_xdp_setup(struct nfp_net *nn, struct netdev_bpf *bpf)
 {
        struct bpf_prog *drv_prog, *offload_prog;
        int err;
 
-       if (nn->xdp_prog && (flags ^ nn->xdp_flags) & XDP_FLAGS_MODES)
+       if (!xdp_attachment_flags_ok(&nn->xdp, bpf))
                return -EBUSY;
 
        /* Load both when no flags set to allow easy activation of driver path
         * when program is replaced by one which can't be offloaded.
         */
-       drv_prog     = flags & XDP_FLAGS_HW_MODE  ? NULL : prog;
-       offload_prog = flags & XDP_FLAGS_DRV_MODE ? NULL : prog;
+       drv_prog     = bpf->flags & XDP_FLAGS_HW_MODE  ? NULL : bpf->prog;
+       offload_prog = bpf->flags & XDP_FLAGS_DRV_MODE ? NULL : bpf->prog;
 
-       err = nfp_net_xdp_setup_drv(nn, drv_prog, extack);
+       err = nfp_net_xdp_setup_drv(nn, drv_prog, bpf->extack);
        if (err)
                return err;
 
-       err = nfp_app_xdp_offload(nn->app, nn, offload_prog, extack);
-       if (err && flags & XDP_FLAGS_HW_MODE)
+       err = nfp_app_xdp_offload(nn->app, nn, offload_prog, bpf->extack);
+       if (err && bpf->flags & XDP_FLAGS_HW_MODE)
                return err;
 
-       if (nn->xdp_prog)
-               bpf_prog_put(nn->xdp_prog);
-       nn->xdp_prog = prog;
-       nn->xdp_flags = flags;
+       xdp_attachment_setup(&nn->xdp, bpf);
 
        return 0;
 }
@@ -3456,12 +3451,9 @@ static int nfp_net_xdp(struct net_device *netdev, struct netdev_bpf *xdp)
        switch (xdp->command) {
        case XDP_SETUP_PROG:
        case XDP_SETUP_PROG_HW:
-               return nfp_net_xdp_setup(nn, xdp->prog, xdp->flags,
-                                        xdp->extack);
+               return nfp_net_xdp_setup(nn, xdp);
        case XDP_QUERY_PROG:
-               xdp->prog_id = nn->xdp_prog ? nn->xdp_prog->aux->id : 0;
-               xdp->prog_flags = nn->xdp_prog ? nn->xdp_flags : 0;
-               return 0;
+               return xdp_attachment_query(&nn->xdp, xdp);
        default:
                return nfp_app_bpf(nn->app, nn, xdp);
        }

diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c
index 712e6f918065f23154eff923de865c5f0762e8ee..c485d97b5df44834c9f2ddd49ea41d04939bc99d 100644 (file)
--- a/drivers/net/netdevsim/bpf.c
+++ b/drivers/net/netdevsim/bpf.c
@@ -199,10 +199,8 @@ static int nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf)
 {
        int err;
 
-       if (ns->xdp_prog && (bpf->flags ^ ns->xdp_flags) & XDP_FLAGS_MODES) {
-               NSIM_EA(bpf->extack, "program loaded with different flags");
+       if (!xdp_attachment_flags_ok(&ns->xdp, bpf))
                return -EBUSY;
-       }
 
        if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) {
                NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS");
@@ -219,11 +217,7 @@ static int nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf)
                        return err;
        }
 
-       if (ns->xdp_prog)
-               bpf_prog_put(ns->xdp_prog);
-
-       ns->xdp_prog = bpf->prog;
-       ns->xdp_flags = bpf->flags;
+       xdp_attachment_setup(&ns->xdp, bpf);
 
        if (!bpf->prog)
                ns->xdp_prog_mode = XDP_ATTACHED_NONE;
@@ -567,9 +561,7 @@ int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
                nsim_bpf_destroy_prog(bpf->offload.prog);
                return 0;
        case XDP_QUERY_PROG:
-               bpf->prog_id = ns->xdp_prog ? ns->xdp_prog->aux->id : 0;
-               bpf->prog_flags = ns->xdp_prog ? ns->xdp_flags : 0;
-               return 0;
+               return xdp_attachment_query(&ns->xdp, bpf);
        case XDP_SETUP_PROG:
                err = nsim_setup_prog_checks(ns, bpf);
                if (err)
@@ -636,6 +628,6 @@ void nsim_bpf_uninit(struct netdevsim *ns)
 {
        WARN_ON(!list_empty(&ns->bpf_bound_progs));
        WARN_ON(!list_empty(&ns->bpf_bound_maps));
-       WARN_ON(ns->xdp_prog);
+       WARN_ON(ns->xdp.prog);
        WARN_ON(ns->bpf_offloaded);
 }

diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index d8a7cc995e8858cb7b0e80284a7e294fc20db7b7..69ffb4a2d14b7061526444aa9d9c791b74d4b29d 100644 (file)
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -18,6 +18,7 @@
 #include <linux/list.h>
 #include <linux/netdevice.h>
 #include <linux/u64_stats_sync.h>
+#include <net/xdp.h>
 
 #define DRV_NAME       "netdevsim"
 
@@ -67,9 +68,8 @@ struct netdevsim {
        struct bpf_prog *bpf_offloaded;
        u32 bpf_offloaded_id;
 
-       u32 xdp_flags;
+       struct xdp_attachment_info xdp;
        int xdp_prog_mode;
-       struct bpf_prog *xdp_prog;
 
        u32 prog_id_gen;
 

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 2deea7166a3486f66a2fd954acc3fcfe2b9d6440..fcb033f51d8c3d00945e3ad6e42d9128fb8bf9d2 100644 (file)
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -144,4 +144,17 @@ xdp_data_meta_unsupported(const struct xdp_buff *xdp)
        return unlikely(xdp->data_meta > xdp->data);
 }
 
+struct xdp_attachment_info {
+       struct bpf_prog *prog;
+       u32 flags;
+};
+
+struct netdev_bpf;
+int xdp_attachment_query(struct xdp_attachment_info *info,
+                        struct netdev_bpf *bpf);
+bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
+                            struct netdev_bpf *bpf);
+void xdp_attachment_setup(struct xdp_attachment_info *info,
+                         struct netdev_bpf *bpf);
+
 #endif /* __LINUX_NET_XDP_H__ */

diff --git a/net/core/xdp.c b/net/core/xdp.c
index 31c58719b5a9a90514d04fd6bee4d80e4e464d9f..57285383ed00c9b3ab7616f4adddfca0d525f850 100644 (file)
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -3,8 +3,11 @@
  * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
  * Released under terms in GPL version 2.  See COPYING.
  */
+#include <linux/bpf.h>
+#include <linux/filter.h>
 #include <linux/types.h>
 #include <linux/mm.h>
+#include <linux/netdevice.h>
 #include <linux/slab.h>
 #include <linux/idr.h>
 #include <linux/rhashtable.h>
@@ -370,3 +373,34 @@ void xdp_return_buff(struct xdp_buff *xdp)
        __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp->handle);
 }
 EXPORT_SYMBOL_GPL(xdp_return_buff);
+
+int xdp_attachment_query(struct xdp_attachment_info *info,
+                        struct netdev_bpf *bpf)
+{
+       bpf->prog_id = info->prog ? info->prog->aux->id : 0;
+       bpf->prog_flags = info->prog ? info->flags : 0;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(xdp_attachment_query);
+
+bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
+                            struct netdev_bpf *bpf)
+{
+       if (info->prog && (bpf->flags ^ info->flags) & XDP_FLAGS_MODES) {
+               NL_SET_ERR_MSG(bpf->extack,
+                              "program loaded with different flags");
+               return false;
+       }
+       return true;
+}
+EXPORT_SYMBOL_GPL(xdp_attachment_flags_ok);
+
+void xdp_attachment_setup(struct xdp_attachment_info *info,
+                         struct netdev_bpf *bpf)
+{
+       if (info->prog)
+               bpf_prog_put(info->prog);
+       info->prog = bpf->prog;
+       info->flags = bpf->flags;
+}
+EXPORT_SYMBOL_GPL(xdp_attachment_setup);

diff --git a/tools/testing/selftests/bpf/test_offload.py b/tools/testing/selftests/bpf/test_offload.py
index f8d9bd81d9a4f99c9e5f8d670ef9c978416b0494..40401e9e9351b6855c662af71e48531bad891847 100755 (executable)
--- a/tools/testing/selftests/bpf/test_offload.py
+++ b/tools/testing/selftests/bpf/test_offload.py
@@ -821,7 +821,7 @@ try:
     ret, _, err = sim.set_xdp(obj, "", force=True,
                               fail=False, include_stderr=True)
     fail(ret == 0, "Replaced XDP program with a program in different mode")
-    check_extack_nsim(err, "program loaded with different flags.", args)
+    check_extack(err, "program loaded with different flags.", args)
 
     start_test("Test XDP prog remove with bad flags...")
     ret, _, err = sim.unset_xdp("offload", force=True,
@@ -831,7 +831,7 @@ try:
     ret, _, err = sim.unset_xdp("", force=True,
                                 fail=False, include_stderr=True)
     fail(ret == 0, "Removed program with a bad mode")
-    check_extack_nsim(err, "program loaded with different flags.", args)
+    check_extack(err, "program loaded with different flags.", args)
 
     start_test("Test MTU restrictions...")
     ret, _ = sim.set_mtu(9000, fail=False)