1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/ip.h> 4 #include <linux/skbuff.h> 5 #include <net/ip6_checksum.h> 6 #include <net/psp.h> 7 #include <net/sock.h> 8 9 #include "netdevsim.h" 10 11 void nsim_psp_handle_ext(struct sk_buff *skb, struct skb_ext *psp_ext) 12 { 13 if (psp_ext) 14 __skb_ext_set(skb, SKB_EXT_PSP, psp_ext); 15 } 16 17 enum skb_drop_reason 18 nsim_do_psp(struct sk_buff *skb, struct netdevsim *ns, 19 struct netdevsim *peer_ns, struct skb_ext **psp_ext) 20 { 21 enum skb_drop_reason rc = 0; 22 struct psp_assoc *pas; 23 struct net *net; 24 void **ptr; 25 26 rcu_read_lock(); 27 pas = psp_skb_get_assoc_rcu(skb); 28 if (!pas) { 29 rc = SKB_NOT_DROPPED_YET; 30 goto out_unlock; 31 } 32 33 if (!skb_transport_header_was_set(skb)) { 34 rc = SKB_DROP_REASON_PSP_OUTPUT; 35 goto out_unlock; 36 } 37 38 ptr = psp_assoc_drv_data(pas); 39 if (*ptr != ns) { 40 rc = SKB_DROP_REASON_PSP_OUTPUT; 41 goto out_unlock; 42 } 43 44 net = sock_net(skb->sk); 45 if (!psp_dev_encapsulate(net, skb, pas->tx.spi, pas->version, 0)) { 46 rc = SKB_DROP_REASON_PSP_OUTPUT; 47 goto out_unlock; 48 } 49 50 /* Now pretend we just received this frame */ 51 if (peer_ns->psp.dev->config.versions & (1 << pas->version)) { 52 bool strip_icv = false; 53 u8 generation; 54 55 /* We cheat a bit and put the generation in the key. 56 * In real life if generation was too old, then decryption would 57 * fail. Here, we just make it so a bad key causes a bad 58 * generation too, and psp_sk_rx_policy_check() will fail. 59 */ 60 generation = pas->tx.key[0]; 61 62 skb_ext_reset(skb); 63 skb->mac_len = ETH_HLEN; 64 if (psp_dev_rcv(skb, peer_ns->psp.dev->id, generation, 65 strip_icv)) { 66 rc = SKB_DROP_REASON_PSP_OUTPUT; 67 goto out_unlock; 68 } 69 70 *psp_ext = skb->extensions; 71 refcount_inc(&(*psp_ext)->refcnt); 72 skb->decrypted = 1; 73 74 u64_stats_update_begin(&ns->psp.syncp); 75 u64_stats_inc(&ns->psp.tx_packets); 76 u64_stats_inc(&ns->psp.rx_packets); 77 u64_stats_add(&ns->psp.tx_bytes, 78 skb->len - skb_inner_transport_offset(skb)); 79 u64_stats_add(&ns->psp.rx_bytes, 80 skb->len - skb_inner_transport_offset(skb)); 81 u64_stats_update_end(&ns->psp.syncp); 82 } else { 83 struct ipv6hdr *ip6h __maybe_unused; 84 struct iphdr *iph; 85 struct udphdr *uh; 86 __wsum csum; 87 88 /* Do not decapsulate. Receive the skb with the udp and psp 89 * headers still there as if this is a normal udp packet. 90 * psp_dev_encapsulate() sets udp checksum to 0, so we need to 91 * provide a valid checksum here, so the skb isn't dropped. 92 */ 93 uh = udp_hdr(skb); 94 csum = skb_checksum(skb, skb_transport_offset(skb), 95 ntohs(uh->len), 0); 96 97 switch (skb->protocol) { 98 case htons(ETH_P_IP): 99 iph = ip_hdr(skb); 100 uh->check = udp_v4_check(ntohs(uh->len), iph->saddr, 101 iph->daddr, csum); 102 break; 103 #if IS_ENABLED(CONFIG_IPV6) 104 case htons(ETH_P_IPV6): 105 ip6h = ipv6_hdr(skb); 106 uh->check = udp_v6_check(ntohs(uh->len), &ip6h->saddr, 107 &ip6h->daddr, csum); 108 break; 109 #endif 110 } 111 112 uh->check = uh->check ?: CSUM_MANGLED_0; 113 skb->ip_summed = CHECKSUM_NONE; 114 } 115 116 out_unlock: 117 rcu_read_unlock(); 118 return rc; 119 } 120 121 static int 122 nsim_psp_set_config(struct psp_dev *psd, struct psp_dev_config *conf, 123 struct netlink_ext_ack *extack) 124 { 125 return 0; 126 } 127 128 static int 129 nsim_rx_spi_alloc(struct psp_dev *psd, u32 version, 130 struct psp_key_parsed *assoc, 131 struct netlink_ext_ack *extack) 132 { 133 struct netdevsim *ns = psd->drv_priv; 134 unsigned int new; 135 int i; 136 137 new = ++ns->psp.spi & PSP_SPI_KEY_ID; 138 if (psd->generation & 1) 139 new |= PSP_SPI_KEY_PHASE; 140 141 assoc->spi = cpu_to_be32(new); 142 assoc->key[0] = psd->generation; 143 for (i = 1; i < PSP_MAX_KEY; i++) 144 assoc->key[i] = ns->psp.spi + i; 145 146 return 0; 147 } 148 149 static int nsim_assoc_add(struct psp_dev *psd, struct psp_assoc *pas, 150 struct netlink_ext_ack *extack) 151 { 152 struct netdevsim *ns = psd->drv_priv; 153 void **ptr = psp_assoc_drv_data(pas); 154 155 /* Copy drv_priv from psd to assoc */ 156 *ptr = psd->drv_priv; 157 ns->psp.assoc_cnt++; 158 159 return 0; 160 } 161 162 static int nsim_key_rotate(struct psp_dev *psd, struct netlink_ext_ack *extack) 163 { 164 return 0; 165 } 166 167 static void nsim_assoc_del(struct psp_dev *psd, struct psp_assoc *pas) 168 { 169 struct netdevsim *ns = psd->drv_priv; 170 void **ptr = psp_assoc_drv_data(pas); 171 172 *ptr = NULL; 173 ns->psp.assoc_cnt--; 174 } 175 176 static void nsim_get_stats(struct psp_dev *psd, struct psp_dev_stats *stats) 177 { 178 struct netdevsim *ns = psd->drv_priv; 179 unsigned int start; 180 181 /* WARNING: do *not* blindly zero stats in real drivers! 182 * All required stats must be reported by the device! 183 */ 184 memset(stats, 0, sizeof(struct psp_dev_stats)); 185 186 do { 187 start = u64_stats_fetch_begin(&ns->psp.syncp); 188 stats->rx_bytes = u64_stats_read(&ns->psp.rx_bytes); 189 stats->rx_packets = u64_stats_read(&ns->psp.rx_packets); 190 stats->tx_bytes = u64_stats_read(&ns->psp.tx_bytes); 191 stats->tx_packets = u64_stats_read(&ns->psp.tx_packets); 192 } while (u64_stats_fetch_retry(&ns->psp.syncp, start)); 193 } 194 195 static struct psp_dev_ops nsim_psp_ops = { 196 .set_config = nsim_psp_set_config, 197 .rx_spi_alloc = nsim_rx_spi_alloc, 198 .tx_key_add = nsim_assoc_add, 199 .tx_key_del = nsim_assoc_del, 200 .key_rotate = nsim_key_rotate, 201 .get_stats = nsim_get_stats, 202 }; 203 204 static struct psp_dev_caps nsim_psp_caps = { 205 .versions = 1 << PSP_VERSION_HDR0_AES_GCM_128 | 206 1 << PSP_VERSION_HDR0_AES_GMAC_128 | 207 1 << PSP_VERSION_HDR0_AES_GCM_256 | 208 1 << PSP_VERSION_HDR0_AES_GMAC_256, 209 .assoc_drv_spc = sizeof(void *), 210 }; 211 212 void nsim_psp_uninit(struct netdevsim *ns) 213 { 214 if (!IS_ERR(ns->psp.dev)) 215 psp_dev_unregister(ns->psp.dev); 216 WARN_ON(ns->psp.assoc_cnt); 217 } 218 219 static ssize_t 220 nsim_psp_rereg_write(struct file *file, const char __user *data, size_t count, 221 loff_t *ppos) 222 { 223 struct netdevsim *ns = file->private_data; 224 int err; 225 226 nsim_psp_uninit(ns); 227 228 ns->psp.dev = psp_dev_create(ns->netdev, &nsim_psp_ops, 229 &nsim_psp_caps, ns); 230 err = PTR_ERR_OR_ZERO(ns->psp.dev); 231 return err ?: count; 232 } 233 234 static const struct file_operations nsim_psp_rereg_fops = { 235 .open = simple_open, 236 .write = nsim_psp_rereg_write, 237 .llseek = generic_file_llseek, 238 .owner = THIS_MODULE, 239 }; 240 241 int nsim_psp_init(struct netdevsim *ns) 242 { 243 struct dentry *ddir = ns->nsim_dev_port->ddir; 244 int err; 245 246 ns->psp.dev = psp_dev_create(ns->netdev, &nsim_psp_ops, 247 &nsim_psp_caps, ns); 248 err = PTR_ERR_OR_ZERO(ns->psp.dev); 249 if (err) 250 return err; 251 252 debugfs_create_file("psp_rereg", 0200, ddir, ns, &nsim_psp_rereg_fops); 253 return 0; 254 } 255