Support BPF_PROG_TYPE_VNET_HASH with TUNSETSTEERINGEBPF ioctl to make it possible to report hash values and types when steering packets.
Signed-off-by: Akihiko Odaki <[email protected]> --- drivers/net/tun.c | 158 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 117 insertions(+), 41 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 89ab9efe522c..e0b453572a64 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -543,19 +543,37 @@ static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb) static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb) { + struct bpf_skb_vnet_hash_end *cb = (struct bpf_skb_vnet_hash_end *)skb->cb; + struct tun_vnet_hash *ext; struct tun_prog *prog; u32 numqueues; - u16 ret = 0; + u16 queue = 0; + + BUILD_BUG_ON(sizeof(*cb) > sizeof(skb->cb)); numqueues = READ_ONCE(tun->numqueues); if (!numqueues) return 0; prog = rcu_dereference(tun->steering_prog); - if (prog) - ret = bpf_prog_run_clear_cb(prog->prog, skb); + if (prog) { + if (prog->prog->type == BPF_PROG_TYPE_VNET_HASH) { + memset(skb->cb, 0, sizeof(*cb) - sizeof(struct qdisc_skb_cb)); + bpf_prog_run_clear_cb(prog->prog, skb); + + ext = skb_ext_add(skb, SKB_EXT_TUN_VNET_HASH); + if (ext) { + ext->value = cb->hash_value; + ext->report = cb->hash_report; + } - return ret % numqueues; + queue = cb->rss_queue; + } else { + queue = bpf_prog_run_clear_cb(prog->prog, skb); + } + } + + return queue % numqueues; } static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb, @@ -2116,31 +2134,74 @@ static ssize_t tun_put_user(struct tun_struct *tun, } if (vnet_hdr_sz) { - struct virtio_net_hdr gso; + struct bpf_skb_vnet_hash_end *cb = (struct bpf_skb_vnet_hash_end *)skb->cb; + struct tun_prog *prog; + struct tun_vnet_hash *vnet_hash_p; + struct tun_vnet_hash vnet_hash; + size_t vnet_hdr_content_sz = sizeof(struct virtio_net_hdr); + union { + struct virtio_net_hdr hdr; + struct virtio_net_hdr_v1_hash hdr_v1_hash; + } vnet_hdr; + int ret; if (iov_iter_count(iter) < vnet_hdr_sz) return -EINVAL; - if (virtio_net_hdr_from_skb(skb, &gso, - tun_is_little_endian(tun), true, - vlan_hlen)) { + if (vnet_hdr_sz >= sizeof(struct virtio_net_hdr_v1_hash)) { + vnet_hash_p = skb_ext_find(skb, SKB_EXT_TUN_VNET_HASH); + if (vnet_hash_p) { + vnet_hash = *vnet_hash_p; + vnet_hdr_content_sz = sizeof(struct virtio_net_hdr_v1_hash); + } else { + rcu_read_lock(); + prog = rcu_dereference(tun->steering_prog); + if (prog && prog->prog->type == BPF_PROG_TYPE_VNET_HASH) { + memset(skb->cb, 0, + sizeof(*cb) - sizeof(struct qdisc_skb_cb)); + bpf_prog_run_clear_cb(prog->prog, skb); + vnet_hash.value = cb->hash_value; + vnet_hash.report = cb->hash_report; + vnet_hdr_content_sz = + sizeof(struct virtio_net_hdr_v1_hash); + } + rcu_read_unlock(); + } + } + + switch (vnet_hdr_content_sz) { + case sizeof(struct virtio_net_hdr): + ret = virtio_net_hdr_from_skb(skb, &vnet_hdr.hdr, + tun_is_little_endian(tun), true, + vlan_hlen); + break; + + case sizeof(struct virtio_net_hdr_v1_hash): + ret = virtio_net_hdr_v1_hash_from_skb(skb, &vnet_hdr.hdr_v1_hash, + tun_is_little_endian(tun), true, + vlan_hlen, + vnet_hash.value, vnet_hash.report); + break; + } + + if (ret) { struct skb_shared_info *sinfo = skb_shinfo(skb); pr_err("unexpected GSO type: " "0x%x, gso_size %d, hdr_len %d\n", - sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size), - tun16_to_cpu(tun, gso.hdr_len)); + sinfo->gso_type, tun16_to_cpu(tun, vnet_hdr.hdr.gso_size), + tun16_to_cpu(tun, vnet_hdr.hdr.hdr_len)); print_hex_dump(KERN_ERR, "tun: ", DUMP_PREFIX_NONE, 16, 1, skb->head, - min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true); + min((int)tun16_to_cpu(tun, vnet_hdr.hdr.hdr_len), 64), true); WARN_ON_ONCE(1); return -EINVAL; } - if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso)) + if (copy_to_iter(&vnet_hdr, vnet_hdr_content_sz, iter) != vnet_hdr_content_sz) return -EFAULT; - iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); + iov_iter_advance(iter, vnet_hdr_sz - vnet_hdr_content_sz); } if (vlan_hlen) { @@ -2276,13 +2337,13 @@ static void tun_prog_free(struct rcu_head *rcu) { struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu); - bpf_prog_destroy(prog->prog); + bpf_prog_put(prog->prog); kfree(prog); } -static int __tun_set_ebpf(struct tun_struct *tun, - struct tun_prog __rcu **prog_p, - struct bpf_prog *prog) +static int tun_set_ebpf(struct tun_struct *tun, + struct tun_prog __rcu **prog_p, + struct bpf_prog *prog) { struct tun_prog *old, *new = NULL; @@ -2314,8 +2375,8 @@ static void tun_free_netdev(struct net_device *dev) free_percpu(dev->tstats); tun_flow_uninit(tun); security_tun_dev_free_security(tun->security); - __tun_set_ebpf(tun, &tun->steering_prog, NULL); - __tun_set_ebpf(tun, &tun->filter_prog, NULL); + tun_set_ebpf(tun, &tun->steering_prog, NULL); + tun_set_ebpf(tun, &tun->filter_prog, NULL); } static void tun_setup(struct net_device *dev) @@ -3007,26 +3068,6 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr) return ret; } -static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog __rcu **prog_p, - void __user *data) -{ - struct bpf_prog *prog; - int fd; - - if (copy_from_user(&fd, data, sizeof(fd))) - return -EFAULT; - - if (fd == -1) { - prog = NULL; - } else { - prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); - if (IS_ERR(prog)) - return PTR_ERR(prog); - } - - return __tun_set_ebpf(tun, prog_p, prog); -} - /* Return correct value for tun->dev->addr_len based on tun->dev->type. */ static unsigned char tun_get_addr_len(unsigned short type) { @@ -3077,6 +3118,8 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, struct ifreq ifr; kuid_t owner; kgid_t group; + struct bpf_prog *prog; + int fd; int sndbuf; int vnet_hdr_sz; int le; @@ -3360,11 +3403,44 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, break; case TUNSETSTEERINGEBPF: - ret = tun_set_ebpf(tun, &tun->steering_prog, argp); + if (copy_from_user(&fd, argp, sizeof(fd))) { + ret = -EFAULT; + break; + } + + if (fd == -1) { + prog = NULL; + } else { + prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_VNET_HASH); + if (IS_ERR(prog)) { + prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); + if (IS_ERR(prog)) { + ret = PTR_ERR(prog); + break; + } + } + } + + ret = tun_set_ebpf(tun, &tun->steering_prog, prog); break; case TUNSETFILTEREBPF: - ret = tun_set_ebpf(tun, &tun->filter_prog, argp); + if (copy_from_user(&fd, argp, sizeof(fd))) { + ret = -EFAULT; + break; + } + + if (fd == -1) { + prog = NULL; + } else { + prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); + if (IS_ERR(prog)) { + ret = PTR_ERR(prog); + break; + } + } + + ret = tun_set_ebpf(tun, &tun->filter_prog, prog); break; case TUNSETCARRIER: -- 2.42.0
