1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2019, Microsoft Corporation. 3 * 4 * Author: 5 * Haiyang Zhang <haiyangz@microsoft.com> 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/netdevice.h> 11 #include <linux/etherdevice.h> 12 #include <linux/ethtool.h> 13 #include <linux/bpf.h> 14 #include <linux/bpf_trace.h> 15 #include <linux/kernel.h> 16 #include <net/xdp.h> 17 18 #include <linux/mutex.h> 19 #include <linux/rtnetlink.h> 20 21 #include "hyperv_net.h" 22 23 u32 netvsc_run_xdp(struct net_device *ndev, struct netvsc_channel *nvchan, 24 struct xdp_buff *xdp) 25 { 26 void *data = nvchan->rsc.data[0]; 27 u32 len = nvchan->rsc.len[0]; 28 struct page *page = NULL; 29 struct bpf_prog *prog; 30 u32 act = XDP_PASS; 31 32 xdp->data_hard_start = NULL; 33 34 rcu_read_lock(); 35 prog = rcu_dereference(nvchan->bpf_prog); 36 37 if (!prog) 38 goto out; 39 40 /* Ensure that the below memcpy() won't overflow the page buffer. */ 41 if (len > ndev->mtu + ETH_HLEN) { 42 act = XDP_DROP; 43 goto out; 44 } 45 46 /* allocate page buffer for data */ 47 page = alloc_page(GFP_ATOMIC); 48 if (!page) { 49 act = XDP_DROP; 50 goto out; 51 } 52 53 xdp_init_buff(xdp, PAGE_SIZE, &nvchan->xdp_rxq); 54 xdp_prepare_buff(xdp, page_address(page), NETVSC_XDP_HDRM, len, false); 55 56 memcpy(xdp->data, data, len); 57 58 act = bpf_prog_run_xdp(prog, xdp); 59 60 switch (act) { 61 case XDP_PASS: 62 case XDP_TX: 63 case XDP_DROP: 64 break; 65 66 case XDP_ABORTED: 67 trace_xdp_exception(ndev, prog, act); 68 break; 69 70 default: 71 bpf_warn_invalid_xdp_action(act); 72 } 73 74 out: 75 rcu_read_unlock(); 76 77 if (page && act != XDP_PASS && act != XDP_TX) { 78 __free_page(page); 79 xdp->data_hard_start = NULL; 80 } 81 82 return act; 83 } 84 85 unsigned int netvsc_xdp_fraglen(unsigned int len) 86 { 87 return SKB_DATA_ALIGN(len) + 88 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 89 } 90 91 struct bpf_prog *netvsc_xdp_get(struct netvsc_device *nvdev) 92 { 93 return rtnl_dereference(nvdev->chan_table[0].bpf_prog); 94 } 95 96 int netvsc_xdp_set(struct net_device *dev, struct bpf_prog *prog, 97 struct netlink_ext_ack *extack, 98 struct netvsc_device *nvdev) 99 { 100 struct bpf_prog *old_prog; 101 int buf_max, i; 102 103 old_prog = netvsc_xdp_get(nvdev); 104 105 if (!old_prog && !prog) 106 return 0; 107 108 buf_max = NETVSC_XDP_HDRM + netvsc_xdp_fraglen(dev->mtu + ETH_HLEN); 109 if (prog && buf_max > PAGE_SIZE) { 110 netdev_err(dev, "XDP: mtu:%u too large, buf_max:%u\n", 111 dev->mtu, buf_max); 112 NL_SET_ERR_MSG_MOD(extack, "XDP: mtu too large"); 113 114 return -EOPNOTSUPP; 115 } 116 117 if (prog && (dev->features & NETIF_F_LRO)) { 118 netdev_err(dev, "XDP: not support LRO\n"); 119 NL_SET_ERR_MSG_MOD(extack, "XDP: not support LRO"); 120 121 return -EOPNOTSUPP; 122 } 123 124 if (prog) 125 bpf_prog_add(prog, nvdev->num_chn - 1); 126 127 for (i = 0; i < nvdev->num_chn; i++) 128 rcu_assign_pointer(nvdev->chan_table[i].bpf_prog, prog); 129 130 if (old_prog) 131 for (i = 0; i < nvdev->num_chn; i++) 132 bpf_prog_put(old_prog); 133 134 return 0; 135 } 136 137 int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog) 138 { 139 struct netdev_bpf xdp; 140 bpf_op_t ndo_bpf; 141 int ret; 142 143 ASSERT_RTNL(); 144 145 if (!vf_netdev) 146 return 0; 147 148 ndo_bpf = vf_netdev->netdev_ops->ndo_bpf; 149 if (!ndo_bpf) 150 return 0; 151 152 memset(&xdp, 0, sizeof(xdp)); 153 154 if (prog) 155 bpf_prog_inc(prog); 156 157 xdp.command = XDP_SETUP_PROG; 158 xdp.prog = prog; 159 160 ret = ndo_bpf(vf_netdev, &xdp); 161 162 if (ret && prog) 163 bpf_prog_put(prog); 164 165 return ret; 166 } 167 168 int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf) 169 { 170 struct net_device_context *ndevctx = netdev_priv(dev); 171 struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev); 172 struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev); 173 struct netlink_ext_ack *extack = bpf->extack; 174 int ret; 175 176 if (!nvdev || nvdev->destroy) { 177 return -ENODEV; 178 } 179 180 switch (bpf->command) { 181 case XDP_SETUP_PROG: 182 ret = netvsc_xdp_set(dev, bpf->prog, extack, nvdev); 183 184 if (ret) 185 return ret; 186 187 ret = netvsc_vf_setxdp(vf_netdev, bpf->prog); 188 189 if (ret) { 190 netdev_err(dev, "vf_setxdp failed:%d\n", ret); 191 NL_SET_ERR_MSG_MOD(extack, "vf_setxdp failed"); 192 193 netvsc_xdp_set(dev, NULL, extack, nvdev); 194 } 195 196 return ret; 197 198 default: 199 return -EINVAL; 200 } 201 } 202