static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) { int err; int hdr_len; struct ipv6hdr *top_iph; struct ipv6_esp_hdr *esph; struct crypto_blkcipher *tfm; struct blkcipher_desc desc; struct esp_data *esp; struct sk_buff *trailer; int blksize; int clen; int alen; int nfrags; esp = x->data; hdr_len = skb->h.raw - skb->data + sizeof(*esph) + esp->conf.ivlen; /* Strip IP+ESP header. */ __skb_pull(skb, hdr_len); /* Now skb is pure payload to encrypt */ err = -ENOMEM; /* Round to block size */ clen = skb->len; alen = esp->auth.icv_trunc_len; tfm = esp->conf.tfm; desc.tfm = tfm; desc.flags = 0; blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4); clen = ALIGN(clen + 2, blksize); if (esp->conf.padlen) clen = ALIGN(clen, esp->conf.padlen); if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) { goto error; } /* Fill padding... */ do { int i; for (i=0; i<clen-skb->len - 2; i++) *(u8*)(trailer->tail + i) = i+1; } while (0); *(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2; pskb_put(skb, trailer, clen - skb->len); top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len); esph = (struct ipv6_esp_hdr *)skb->h.raw; top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph)); *(u8*)(trailer->tail - 1) = *skb->nh.raw; *skb->nh.raw = IPPROTO_ESP; esph->spi = x->id.spi; esph->seq_no = htonl(++x->replay.oseq); xfrm_aevent_doreplay(x); if (esp->conf.ivlen) { if (unlikely(!esp->conf.ivinitted)) { get_random_bytes(esp->conf.ivec, esp->conf.ivlen); esp->conf.ivinitted = 1; } crypto_blkcipher_set_iv(tfm, esp->conf.ivec, esp->conf.ivlen); } do { struct scatterlist *sg = &esp->sgbuf[0]; if (unlikely(nfrags > ESP_NUM_FAST_SG)) { sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC); if (!sg) goto error; } skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen); err = crypto_blkcipher_encrypt(&desc, sg, sg, clen); if (unlikely(sg != &esp->sgbuf[0])) kfree(sg); } while (0); if (unlikely(err)) goto error; if (esp->conf.ivlen) { memcpy(esph->enc_data, esp->conf.ivec, esp->conf.ivlen); crypto_blkcipher_get_iv(tfm, esp->conf.ivec, esp->conf.ivlen); } if (esp->auth.icv_full_len) { err = esp_mac_digest(esp, skb, (u8 *)esph - skb->data, sizeof(*esph) + esp->conf.ivlen + clen); memcpy(pskb_put(skb, trailer, alen), esp->auth.work_icv, alen); } error: return err; }
/* * Note: detecting truncated vs. non-truncated authentication data is very * expensive, so we only support truncated data, which is the recommended * and common case. */ static int esp_input(struct xfrm_state *x, struct sk_buff *skb) { struct iphdr *iph; struct ip_esp_hdr *esph; struct esp_data *esp = x->data; struct crypto_blkcipher *tfm = esp->conf.tfm; struct blkcipher_desc desc = { .tfm = tfm }; struct sk_buff *trailer; int blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4); int alen = esp->auth.icv_trunc_len; int elen = skb->len - sizeof(struct ip_esp_hdr) - esp->conf.ivlen - alen; int nfrags; int ihl; u8 nexthdr[2]; struct scatterlist *sg; int padlen; int err; if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr))) goto out; if (elen <= 0 || (elen & (blksize-1))) goto out; /* If integrity check is required, do this. */ if (esp->auth.icv_full_len) { u8 sum[alen]; err = esp_mac_digest(esp, skb, 0, skb->len - alen); if (err) goto out; if (skb_copy_bits(skb, skb->len - alen, sum, alen)) BUG(); if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) { x->stats.integrity_failed++; goto out; } } if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) goto out; skb->ip_summed = CHECKSUM_NONE; esph = (struct ip_esp_hdr*)skb->data; /* Get ivec. This can be wrong, check against another impls. */ if (esp->conf.ivlen) crypto_blkcipher_set_iv(tfm, esph->enc_data, esp->conf.ivlen); sg = &esp->sgbuf[0]; if (unlikely(nfrags > ESP_NUM_FAST_SG)) { sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC); if (!sg) goto out; } skb_to_sgvec(skb, sg, sizeof(struct ip_esp_hdr) + esp->conf.ivlen, elen); err = crypto_blkcipher_decrypt(&desc, sg, sg, elen); if (unlikely(sg != &esp->sgbuf[0])) kfree(sg); if (unlikely(err)) return err; if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) BUG(); padlen = nexthdr[0]; if (padlen+2 >= elen) goto out; /* ... check padding bits here. Silly. :-) */ iph = skb->nh.iph; ihl = iph->ihl * 4; if (x->encap) { struct xfrm_encap_tmpl *encap = x->encap; struct udphdr *uh = (void *)(skb->nh.raw + ihl); /* * 1) if the NAT-T peer's IP or port changed then * advertize the change to the keying daemon. * This is an inbound SA, so just compare * SRC ports. */ if (iph->saddr != x->props.saddr.a4 || uh->source != encap->encap_sport) { xfrm_address_t ipaddr; ipaddr.a4 = iph->saddr; km_new_mapping(x, &ipaddr, uh->source); /* XXX: perhaps add an extra * policy check here, to see * if we should allow or * reject a packet from a * different source * address/port. */ } /* * 2) ignore UDP/TCP checksums in case * of NAT-T in Transport Mode, or * perform other post-processing fixes * as per draft-ietf-ipsec-udp-encaps-06, * section 3.1.2 */ if (x->props.mode == XFRM_MODE_TRANSPORT || x->props.mode == XFRM_MODE_BEET) skb->ip_summed = CHECKSUM_UNNECESSARY; } iph->protocol = nexthdr[1]; pskb_trim(skb, skb->len - alen - padlen - 2); skb->h.raw = __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen) - ihl; return 0; out: return -EINVAL; }
static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) { struct ipv6hdr *iph; struct ipv6_esp_hdr *esph; struct esp_data *esp = x->data; struct crypto_blkcipher *tfm = esp->conf.tfm; struct blkcipher_desc desc = { .tfm = tfm }; struct sk_buff *trailer; int blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4); int alen = esp->auth.icv_trunc_len; int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen; int hdr_len = skb->h.raw - skb->nh.raw; int nfrags; int ret = 0; if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) { ret = -EINVAL; goto out; } if (elen <= 0 || (elen & (blksize-1))) { ret = -EINVAL; goto out; } /* If integrity check is required, do this. */ if (esp->auth.icv_full_len) { u8 sum[alen]; ret = esp_mac_digest(esp, skb, 0, skb->len - alen); if (ret) goto out; if (skb_copy_bits(skb, skb->len - alen, sum, alen)) BUG(); if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) { x->stats.integrity_failed++; ret = -EINVAL; goto out; } } if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) { ret = -EINVAL; goto out; } skb->ip_summed = CHECKSUM_NONE; esph = (struct ipv6_esp_hdr*)skb->data; iph = skb->nh.ipv6h; /* Get ivec. This can be wrong, check against another impls. */ if (esp->conf.ivlen) crypto_blkcipher_set_iv(tfm, esph->enc_data, esp->conf.ivlen); { u8 nexthdr[2]; struct scatterlist *sg = &esp->sgbuf[0]; u8 padlen; if (unlikely(nfrags > ESP_NUM_FAST_SG)) { sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC); if (!sg) { ret = -ENOMEM; goto out; } } skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen); ret = crypto_blkcipher_decrypt(&desc, sg, sg, elen); if (unlikely(sg != &esp->sgbuf[0])) kfree(sg); if (unlikely(ret)) goto out; if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) BUG(); padlen = nexthdr[0]; if (padlen+2 >= elen) { LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen); ret = -EINVAL; goto out; } /* ... check padding bits here. Silly. :-) */ pskb_trim(skb, skb->len - alen - padlen - 2); ret = nexthdr[1]; } skb->h.raw = __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen) - hdr_len; out: return ret; }
static int esp_output(struct xfrm_state *x, struct sk_buff *skb) { int err; struct iphdr *top_iph; struct ip_esp_hdr *esph; struct crypto_blkcipher *tfm; struct blkcipher_desc desc; struct esp_data *esp; struct sk_buff *trailer; int blksize; int clen; int alen; int nfrags; /* Strip IP+ESP header. */ __skb_pull(skb, skb->h.raw - skb->data); /* Now skb is pure payload to encrypt */ err = -ENOMEM; /* Round to block size */ clen = skb->len; esp = x->data; alen = esp->auth.icv_trunc_len; tfm = esp->conf.tfm; desc.tfm = tfm; desc.flags = 0; blksize = ALIGN(crypto_blkcipher_blocksize(tfm), 4); clen = ALIGN(clen + 2, blksize); if (esp->conf.padlen) clen = ALIGN(clen, esp->conf.padlen); if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) goto error; /* Fill padding... */ do { int i; for (i=0; i<clen-skb->len - 2; i++) *(u8*)(trailer->tail + i) = i+1; } while (0); *(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2; pskb_put(skb, trailer, clen - skb->len); __skb_push(skb, skb->data - skb->nh.raw); top_iph = skb->nh.iph; esph = (struct ip_esp_hdr *)(skb->nh.raw + top_iph->ihl*4); top_iph->tot_len = htons(skb->len + alen); *(u8*)(trailer->tail - 1) = top_iph->protocol; /* this is non-NULL only with UDP Encapsulation */ if (x->encap) { struct xfrm_encap_tmpl *encap = x->encap; struct udphdr *uh; u32 *udpdata32; uh = (struct udphdr *)esph; uh->source = encap->encap_sport; uh->dest = encap->encap_dport; uh->len = htons(skb->len + alen - top_iph->ihl*4); uh->check = 0; switch (encap->encap_type) { default: case UDP_ENCAP_ESPINUDP: esph = (struct ip_esp_hdr *)(uh + 1); break; case UDP_ENCAP_ESPINUDP_NON_IKE: udpdata32 = (u32 *)(uh + 1); udpdata32[0] = udpdata32[1] = 0; esph = (struct ip_esp_hdr *)(udpdata32 + 2); break; } top_iph->protocol = IPPROTO_UDP; } else top_iph->protocol = IPPROTO_ESP; esph->spi = x->id.spi; esph->seq_no = htonl(++x->replay.oseq); xfrm_aevent_doreplay(x); if (esp->conf.ivlen) { if (unlikely(!esp->conf.ivinitted)) { get_random_bytes(esp->conf.ivec, esp->conf.ivlen); esp->conf.ivinitted = 1; } crypto_blkcipher_set_iv(tfm, esp->conf.ivec, esp->conf.ivlen); } do { struct scatterlist *sg = &esp->sgbuf[0]; if (unlikely(nfrags > ESP_NUM_FAST_SG)) { sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC); if (!sg) goto error; } skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen); err = crypto_blkcipher_encrypt(&desc, sg, sg, clen); if (unlikely(sg != &esp->sgbuf[0])) kfree(sg); } while (0); if (unlikely(err)) goto error; if (esp->conf.ivlen) { memcpy(esph->enc_data, esp->conf.ivec, esp->conf.ivlen); crypto_blkcipher_get_iv(tfm, esp->conf.ivec, esp->conf.ivlen); } if (esp->auth.icv_full_len) { err = esp_mac_digest(esp, skb, (u8 *)esph - skb->data, sizeof(*esph) + esp->conf.ivlen + clen); memcpy(pskb_put(skb, trailer, alen), esp->auth.work_icv, alen); } ip_send_check(top_iph); error: return err; }