1 /* 2 * xfrm_input.c 3 * 4 * Changes: 5 * YOSHIFUJI Hideaki @USAGI 6 * Split up af-specific portion 7 * 8 */ 9 10 #include <linux/slab.h> 11 #include <linux/module.h> 12 #include <linux/netdevice.h> 13 #include <net/dst.h> 14 #include <net/ip.h> 15 #include <net/xfrm.h> 16 17 static struct kmem_cache *secpath_cachep __read_mostly; 18 19 void __secpath_destroy(struct sec_path *sp) 20 { 21 int i; 22 for (i = 0; i < sp->len; i++) 23 xfrm_state_put(sp->xvec[i]); 24 kmem_cache_free(secpath_cachep, sp); 25 } 26 EXPORT_SYMBOL(__secpath_destroy); 27 28 struct sec_path *secpath_dup(struct sec_path *src) 29 { 30 struct sec_path *sp; 31 32 sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC); 33 if (!sp) 34 return NULL; 35 36 sp->len = 0; 37 if (src) { 38 int i; 39 40 memcpy(sp, src, sizeof(*sp)); 41 for (i = 0; i < sp->len; i++) 42 xfrm_state_hold(sp->xvec[i]); 43 } 44 atomic_set(&sp->refcnt, 1); 45 return sp; 46 } 47 EXPORT_SYMBOL(secpath_dup); 48 49 /* Fetch spi and seq from ipsec header */ 50 51 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq) 52 { 53 int offset, offset_seq; 54 int hlen; 55 56 switch (nexthdr) { 57 case IPPROTO_AH: 58 hlen = sizeof(struct ip_auth_hdr); 59 offset = offsetof(struct ip_auth_hdr, spi); 60 offset_seq = offsetof(struct ip_auth_hdr, seq_no); 61 break; 62 case IPPROTO_ESP: 63 hlen = sizeof(struct ip_esp_hdr); 64 offset = offsetof(struct ip_esp_hdr, spi); 65 offset_seq = offsetof(struct ip_esp_hdr, seq_no); 66 break; 67 case IPPROTO_COMP: 68 if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr))) 69 return -EINVAL; 70 *spi = htonl(ntohs(*(__be16*)(skb_transport_header(skb) + 2))); 71 *seq = 0; 72 return 0; 73 default: 74 return 1; 75 } 76 77 if (!pskb_may_pull(skb, hlen)) 78 return -EINVAL; 79 80 *spi = *(__be32*)(skb_transport_header(skb) + offset); 81 *seq = *(__be32*)(skb_transport_header(skb) + offset_seq); 82 return 0; 83 } 84 85 int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb) 86 { 87 struct xfrm_mode *inner_mode = x->inner_mode; 88 int err; 89 90 err = x->outer_mode->afinfo->extract_input(x, skb); 91 if (err) 92 return err; 93 94 if (x->sel.family == AF_UNSPEC) { 95 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); 96 if (inner_mode == NULL) 97 return -EAFNOSUPPORT; 98 } 99 100 skb->protocol = inner_mode->afinfo->eth_proto; 101 return inner_mode->input2(x, skb); 102 } 103 EXPORT_SYMBOL(xfrm_prepare_input); 104 105 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type) 106 { 107 int err; 108 __be32 seq; 109 struct xfrm_state *x; 110 xfrm_address_t *daddr; 111 struct xfrm_mode *inner_mode; 112 unsigned int family; 113 int decaps = 0; 114 int async = 0; 115 116 /* A negative encap_type indicates async resumption. */ 117 if (encap_type < 0) { 118 async = 1; 119 x = xfrm_input_state(skb); 120 seq = XFRM_SKB_CB(skb)->seq.input; 121 goto resume; 122 } 123 124 /* Allocate new secpath or COW existing one. */ 125 if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) { 126 struct sec_path *sp; 127 128 sp = secpath_dup(skb->sp); 129 if (!sp) { 130 XFRM_INC_STATS(LINUX_MIB_XFRMINERROR); 131 goto drop; 132 } 133 if (skb->sp) 134 secpath_put(skb->sp); 135 skb->sp = sp; 136 } 137 138 daddr = (xfrm_address_t *)(skb_network_header(skb) + 139 XFRM_SPI_SKB_CB(skb)->daddroff); 140 family = XFRM_SPI_SKB_CB(skb)->family; 141 142 seq = 0; 143 if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) { 144 XFRM_INC_STATS(LINUX_MIB_XFRMINHDRERROR); 145 goto drop; 146 } 147 148 do { 149 if (skb->sp->len == XFRM_MAX_DEPTH) { 150 XFRM_INC_STATS(LINUX_MIB_XFRMINBUFFERERROR); 151 goto drop; 152 } 153 154 x = xfrm_state_lookup(daddr, spi, nexthdr, family); 155 if (x == NULL) { 156 XFRM_INC_STATS(LINUX_MIB_XFRMINNOSTATES); 157 xfrm_audit_state_notfound(skb, family, spi, seq); 158 goto drop; 159 } 160 161 skb->sp->xvec[skb->sp->len++] = x; 162 163 spin_lock(&x->lock); 164 if (unlikely(x->km.state != XFRM_STATE_VALID)) { 165 XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEINVALID); 166 goto drop_unlock; 167 } 168 169 if ((x->encap ? x->encap->encap_type : 0) != encap_type) { 170 XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEMISMATCH); 171 goto drop_unlock; 172 } 173 174 if (x->props.replay_window && xfrm_replay_check(x, skb, seq)) { 175 XFRM_INC_STATS(LINUX_MIB_XFRMINSTATESEQERROR); 176 goto drop_unlock; 177 } 178 179 if (xfrm_state_check_expire(x)) { 180 XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEEXPIRED); 181 goto drop_unlock; 182 } 183 184 spin_unlock(&x->lock); 185 186 XFRM_SKB_CB(skb)->seq.input = seq; 187 188 nexthdr = x->type->input(x, skb); 189 190 if (nexthdr == -EINPROGRESS) 191 return 0; 192 193 resume: 194 spin_lock(&x->lock); 195 if (nexthdr <= 0) { 196 if (nexthdr == -EBADMSG) { 197 xfrm_audit_state_icvfail(x, skb, 198 x->type->proto); 199 x->stats.integrity_failed++; 200 } 201 XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEPROTOERROR); 202 goto drop_unlock; 203 } 204 205 /* only the first xfrm gets the encap type */ 206 encap_type = 0; 207 208 if (x->props.replay_window) 209 xfrm_replay_advance(x, seq); 210 211 x->curlft.bytes += skb->len; 212 x->curlft.packets++; 213 214 spin_unlock(&x->lock); 215 216 XFRM_MODE_SKB_CB(skb)->protocol = nexthdr; 217 218 inner_mode = x->inner_mode; 219 220 if (x->sel.family == AF_UNSPEC) { 221 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); 222 if (inner_mode == NULL) 223 goto drop; 224 } 225 226 if (inner_mode->input(x, skb)) { 227 XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEMODEERROR); 228 goto drop; 229 } 230 231 if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) { 232 decaps = 1; 233 break; 234 } 235 236 /* 237 * We need the inner address. However, we only get here for 238 * transport mode so the outer address is identical. 239 */ 240 daddr = &x->id.daddr; 241 family = x->outer_mode->afinfo->family; 242 243 err = xfrm_parse_spi(skb, nexthdr, &spi, &seq); 244 if (err < 0) { 245 XFRM_INC_STATS(LINUX_MIB_XFRMINHDRERROR); 246 goto drop; 247 } 248 } while (!err); 249 250 nf_reset(skb); 251 252 if (decaps) { 253 dst_release(skb->dst); 254 skb->dst = NULL; 255 netif_rx(skb); 256 return 0; 257 } else { 258 return x->inner_mode->afinfo->transport_finish(skb, async); 259 } 260 261 drop_unlock: 262 spin_unlock(&x->lock); 263 drop: 264 kfree_skb(skb); 265 return 0; 266 } 267 EXPORT_SYMBOL(xfrm_input); 268 269 int xfrm_input_resume(struct sk_buff *skb, int nexthdr) 270 { 271 return xfrm_input(skb, nexthdr, 0, -1); 272 } 273 EXPORT_SYMBOL(xfrm_input_resume); 274 275 void __init xfrm_input_init(void) 276 { 277 secpath_cachep = kmem_cache_create("secpath_cache", 278 sizeof(struct sec_path), 279 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, 280 NULL); 281 } 282