From 788f87ac608c518b74f338acb95f197cf6e3d0c4 Mon Sep 17 00:00:00 2001 From: Ioana Ciornei Date: Wed, 22 Apr 2020 15:05:09 +0300 Subject: xdp: export the DEV_MAP_BULK_SIZE macro Export the DEV_MAP_BULK_SIZE macro to the header file so that drivers can directly use it as the maximum number of xdp_frames received in the .ndo_xdp_xmit() callback. Signed-off-by: Ioana Ciornei Acked-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- kernel/bpf/devmap.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel/bpf/devmap.c') diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 58bdca5d978a..a51d9fb7a359 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -52,7 +52,6 @@ #define DEV_CREATE_FLAG_MASK \ (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) -#define DEV_MAP_BULK_SIZE 16 struct xdp_dev_bulk_queue { struct xdp_frame *q[DEV_MAP_BULK_SIZE]; struct list_head flush_node; -- cgit v1.2.3 From 7f1c04269fe7b3293dea38ea65da4fd6614d6f80 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Fri, 29 May 2020 16:07:12 -0600 Subject: devmap: Formalize map value as a named struct MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add 'struct bpf_devmap_val' to formalize the expected values that can be passed in for a DEVMAP. Update devmap code to use the struct. Signed-off-by: David Ahern Signed-off-by: Alexei Starovoitov Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20200529220716.75383-2-dsahern@kernel.org Signed-off-by: Alexei Starovoitov --- kernel/bpf/devmap.c | 45 ++++++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 17 deletions(-) (limited to 'kernel/bpf/devmap.c') diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index a51d9fb7a359..a1459de0914e 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -60,12 +60,18 @@ struct xdp_dev_bulk_queue { unsigned int count; }; +/* DEVMAP values */ +struct bpf_devmap_val { + u32 ifindex; /* device index */ +}; + struct bpf_dtab_netdev { struct net_device *dev; /* must be first member, due to tracepoint */ struct hlist_node index_hlist; struct bpf_dtab *dtab; struct rcu_head rcu; unsigned int idx; + struct bpf_devmap_val val; }; struct bpf_dtab { @@ -472,18 +478,15 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, static void *dev_map_lookup_elem(struct bpf_map *map, void *key) { struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key); - struct net_device *dev = obj ? obj->dev : NULL; - return dev ? &dev->ifindex : NULL; + return obj ? &obj->val : NULL; } static void *dev_map_hash_lookup_elem(struct bpf_map *map, void *key) { struct bpf_dtab_netdev *obj = __dev_map_hash_lookup_elem(map, *(u32 *)key); - struct net_device *dev = obj ? obj->dev : NULL; - - return dev ? &dev->ifindex : NULL; + return obj ? &obj->val : NULL; } static void __dev_map_entry_free(struct rcu_head *rcu) @@ -541,7 +544,7 @@ static int dev_map_hash_delete_elem(struct bpf_map *map, void *key) static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net, struct bpf_dtab *dtab, - u32 ifindex, + struct bpf_devmap_val *val, unsigned int idx) { struct bpf_dtab_netdev *dev; @@ -551,16 +554,18 @@ static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net, if (!dev) return ERR_PTR(-ENOMEM); - dev->dev = dev_get_by_index(net, ifindex); - if (!dev->dev) { - kfree(dev); - return ERR_PTR(-EINVAL); - } + dev->dev = dev_get_by_index(net, val->ifindex); + if (!dev->dev) + goto err_out; dev->idx = idx; dev->dtab = dtab; + dev->val.ifindex = val->ifindex; return dev; +err_out: + kfree(dev); + return ERR_PTR(-EINVAL); } static int __dev_map_update_elem(struct net *net, struct bpf_map *map, @@ -568,7 +573,7 @@ static int __dev_map_update_elem(struct net *net, struct bpf_map *map, { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct bpf_dtab_netdev *dev, *old_dev; - u32 ifindex = *(u32 *)value; + struct bpf_devmap_val val = { }; u32 i = *(u32 *)key; if (unlikely(map_flags > BPF_EXIST)) @@ -578,10 +583,13 @@ static int __dev_map_update_elem(struct net *net, struct bpf_map *map, if (unlikely(map_flags == BPF_NOEXIST)) return -EEXIST; - if (!ifindex) { + /* already verified value_size <= sizeof val */ + memcpy(&val, value, map->value_size); + + if (!val.ifindex) { dev = NULL; } else { - dev = __dev_map_alloc_node(net, dtab, ifindex, i); + dev = __dev_map_alloc_node(net, dtab, &val, i); if (IS_ERR(dev)) return PTR_ERR(dev); } @@ -609,12 +617,15 @@ static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map, { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct bpf_dtab_netdev *dev, *old_dev; - u32 ifindex = *(u32 *)value; + struct bpf_devmap_val val = { }; u32 idx = *(u32 *)key; unsigned long flags; int err = -EEXIST; - if (unlikely(map_flags > BPF_EXIST || !ifindex)) + /* already verified value_size <= sizeof val */ + memcpy(&val, value, map->value_size); + + if (unlikely(map_flags > BPF_EXIST || !val.ifindex)) return -EINVAL; spin_lock_irqsave(&dtab->index_lock, flags); @@ -623,7 +634,7 @@ static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map, if (old_dev && (map_flags & BPF_NOEXIST)) goto out_err; - dev = __dev_map_alloc_node(net, dtab, ifindex, idx); + dev = __dev_map_alloc_node(net, dtab, &val, idx); if (IS_ERR(dev)) { err = PTR_ERR(dev); goto out_err; -- cgit v1.2.3 From fbee97feed9b3e4acdf9590e1f6b4a2eefecfffe Mon Sep 17 00:00:00 2001 From: David Ahern Date: Fri, 29 May 2020 16:07:13 -0600 Subject: bpf: Add support to attach bpf program to a devmap entry MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add BPF_XDP_DEVMAP attach type for use with programs associated with a DEVMAP entry. Allow DEVMAPs to associate a program with a device entry by adding a bpf_prog.fd to 'struct bpf_devmap_val'. Values read show the program id, so the fd and id are a union. bpf programs can get access to the struct via vmlinux.h. The program associated with the fd must have type XDP with expected attach type BPF_XDP_DEVMAP. When a program is associated with a device index, the program is run on an XDP_REDIRECT and before the buffer is added to the per-cpu queue. At this point rxq data is still valid; the next patch adds tx device information allowing the prorgam to see both ingress and egress device indices. XDP generic is skb based and XDP programs do not work with skb's. Block the use case by walking maps used by a program that is to be attached via xdpgeneric and fail if any of them are DEVMAP / DEVMAP_HASH with Block attach of BPF_XDP_DEVMAP programs to devices. Signed-off-by: David Ahern Signed-off-by: Alexei Starovoitov Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20200529220716.75383-3-dsahern@kernel.org Signed-off-by: Alexei Starovoitov --- kernel/bpf/devmap.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 84 insertions(+), 4 deletions(-) (limited to 'kernel/bpf/devmap.c') diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index a1459de0914e..0089d56617ec 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -63,12 +63,17 @@ struct xdp_dev_bulk_queue { /* DEVMAP values */ struct bpf_devmap_val { u32 ifindex; /* device index */ + union { + int fd; /* prog fd on map write */ + u32 id; /* prog id on map read */ + } bpf_prog; }; struct bpf_dtab_netdev { struct net_device *dev; /* must be first member, due to tracepoint */ struct hlist_node index_hlist; struct bpf_dtab *dtab; + struct bpf_prog *xdp_prog; struct rcu_head rcu; unsigned int idx; struct bpf_devmap_val val; @@ -111,12 +116,18 @@ static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab, static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) { + u32 valsize = attr->value_size; u64 cost = 0; int err; - /* check sanity of attributes */ + /* check sanity of attributes. 2 value sizes supported: + * 4 bytes: ifindex + * 8 bytes: ifindex + prog fd + */ if (attr->max_entries == 0 || attr->key_size != 4 || - attr->value_size != 4 || attr->map_flags & ~DEV_CREATE_FLAG_MASK) + (valsize != offsetofend(struct bpf_devmap_val, ifindex) && + valsize != offsetofend(struct bpf_devmap_val, bpf_prog.fd)) || + attr->map_flags & ~DEV_CREATE_FLAG_MASK) return -EINVAL; /* Lookup returns a pointer straight to dev->ifindex, so make sure the @@ -223,6 +234,8 @@ static void dev_map_free(struct bpf_map *map) hlist_for_each_entry_safe(dev, next, head, index_hlist) { hlist_del_rcu(&dev->index_hlist); + if (dev->xdp_prog) + bpf_prog_put(dev->xdp_prog); dev_put(dev->dev); kfree(dev); } @@ -237,6 +250,8 @@ static void dev_map_free(struct bpf_map *map) if (!dev) continue; + if (dev->xdp_prog) + bpf_prog_put(dev->xdp_prog); dev_put(dev->dev); kfree(dev); } @@ -323,6 +338,16 @@ static int dev_map_hash_get_next_key(struct bpf_map *map, void *key, return -ENOENT; } +bool dev_map_can_have_prog(struct bpf_map *map) +{ + if ((map->map_type == BPF_MAP_TYPE_DEVMAP || + map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) && + map->value_size != offsetofend(struct bpf_devmap_val, ifindex)) + return true; + + return false; +} + static int bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags) { struct net_device *dev = bq->dev; @@ -447,6 +472,30 @@ static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, return bq_enqueue(dev, xdpf, dev_rx); } +static struct xdp_buff *dev_map_run_prog(struct net_device *dev, + struct xdp_buff *xdp, + struct bpf_prog *xdp_prog) +{ + u32 act; + + act = bpf_prog_run_xdp(xdp_prog, xdp); + switch (act) { + case XDP_PASS: + return xdp; + case XDP_DROP: + break; + default: + bpf_warn_invalid_xdp_action(act); + fallthrough; + case XDP_ABORTED: + trace_xdp_exception(dev, xdp_prog, act); + break; + } + + xdp_return_buff(xdp); + return NULL; +} + int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, struct net_device *dev_rx) { @@ -458,6 +507,11 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp, { struct net_device *dev = dst->dev; + if (dst->xdp_prog) { + xdp = dev_map_run_prog(dev, xdp, dst->xdp_prog); + if (!xdp) + return 0; + } return __xdp_enqueue(dev, xdp, dev_rx); } @@ -494,6 +548,8 @@ static void __dev_map_entry_free(struct rcu_head *rcu) struct bpf_dtab_netdev *dev; dev = container_of(rcu, struct bpf_dtab_netdev, rcu); + if (dev->xdp_prog) + bpf_prog_put(dev->xdp_prog); dev_put(dev->dev); kfree(dev); } @@ -547,6 +603,7 @@ static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net, struct bpf_devmap_val *val, unsigned int idx) { + struct bpf_prog *prog = NULL; struct bpf_dtab_netdev *dev; dev = kmalloc_node(sizeof(*dev), GFP_ATOMIC | __GFP_NOWARN, @@ -558,11 +615,31 @@ static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net, if (!dev->dev) goto err_out; + if (val->bpf_prog.fd >= 0) { + prog = bpf_prog_get_type_dev(val->bpf_prog.fd, + BPF_PROG_TYPE_XDP, false); + if (IS_ERR(prog)) + goto err_put_dev; + if (prog->expected_attach_type != BPF_XDP_DEVMAP) + goto err_put_prog; + } + dev->idx = idx; dev->dtab = dtab; + if (prog) { + dev->xdp_prog = prog; + dev->val.bpf_prog.id = prog->aux->id; + } else { + dev->xdp_prog = NULL; + dev->val.bpf_prog.id = 0; + } dev->val.ifindex = val->ifindex; return dev; +err_put_prog: + bpf_prog_put(prog); +err_put_dev: + dev_put(dev->dev); err_out: kfree(dev); return ERR_PTR(-EINVAL); @@ -572,8 +649,8 @@ static int __dev_map_update_elem(struct net *net, struct bpf_map *map, void *key, void *value, u64 map_flags) { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); + struct bpf_devmap_val val = { .bpf_prog.fd = -1 }; struct bpf_dtab_netdev *dev, *old_dev; - struct bpf_devmap_val val = { }; u32 i = *(u32 *)key; if (unlikely(map_flags > BPF_EXIST)) @@ -588,6 +665,9 @@ static int __dev_map_update_elem(struct net *net, struct bpf_map *map, if (!val.ifindex) { dev = NULL; + /* can not specify fd if ifindex is 0 */ + if (val.bpf_prog.fd != -1) + return -EINVAL; } else { dev = __dev_map_alloc_node(net, dtab, &val, i); if (IS_ERR(dev)) @@ -616,8 +696,8 @@ static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map, void *key, void *value, u64 map_flags) { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); + struct bpf_devmap_val val = { .bpf_prog.fd = -1 }; struct bpf_dtab_netdev *dev, *old_dev; - struct bpf_devmap_val val = { }; u32 idx = *(u32 *)key; unsigned long flags; int err = -EEXIST; -- cgit v1.2.3 From 64b59025c15b244c0954cf52b24fbabfcf5ed8f6 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Fri, 29 May 2020 16:07:14 -0600 Subject: xdp: Add xdp_txq_info to xdp_buff MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add xdp_txq_info as the Tx counterpart to xdp_rxq_info. At the moment only the device is added. Other fields (queue_index) can be added as use cases arise. >From a UAPI perspective, add egress_ifindex to xdp context for bpf programs to see the Tx device. Update the verifier to only allow accesses to egress_ifindex by XDP programs with BPF_XDP_DEVMAP expected attach type. Signed-off-by: David Ahern Signed-off-by: Alexei Starovoitov Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20200529220716.75383-4-dsahern@kernel.org Signed-off-by: Alexei Starovoitov --- kernel/bpf/devmap.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/bpf/devmap.c') diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 0089d56617ec..c04fb1c72f5e 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -476,8 +476,11 @@ static struct xdp_buff *dev_map_run_prog(struct net_device *dev, struct xdp_buff *xdp, struct bpf_prog *xdp_prog) { + struct xdp_txq_info txq = { .dev = dev }; u32 act; + xdp->txq = &txq; + act = bpf_prog_run_xdp(xdp_prog, xdp); switch (act) { case XDP_PASS: -- cgit v1.2.3 From 1b698fa5d8ef958007c455e316aa44c37ab3c5fb Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Thu, 28 May 2020 22:47:29 +0200 Subject: xdp: Rename convert_to_xdp_frame in xdp_convert_buff_to_frame In order to use standard 'xdp' prefix, rename convert_to_xdp_frame utility routine in xdp_convert_buff_to_frame and replace all the occurrences Signed-off-by: Lorenzo Bianconi Signed-off-by: Alexei Starovoitov Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/6344f739be0d1a08ab2b9607584c4d5478c8c083.1590698295.git.lorenzo@kernel.org --- kernel/bpf/devmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/bpf/devmap.c') diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index c04fb1c72f5e..854b09beb16b 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -465,7 +465,7 @@ static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, if (unlikely(err)) return err; - xdpf = convert_to_xdp_frame(xdp); + xdpf = xdp_convert_buff_to_frame(xdp); if (unlikely(!xdpf)) return -EOVERFLOW; -- cgit v1.2.3