From fca11ebde3f0d1c637550a9b231caa385ce35749 Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Fri, 14 Apr 2017 10:06:33 +0200 Subject: esp4: Reorganize esp_output We need a fallback for ESP at layer 2, so split esp_output into generic functions that can be used at layer 3 and layer 2 and use them in esp_output. We also add esp_xmit which is used for the layer 2 fallback. Signed-off-by: Steffen Klassert --- net/ipv4/esp4.c | 341 ++++++++++++++++++++++++++++++-------------------------- 1 file changed, 183 insertions(+), 158 deletions(-) (limited to 'net/ipv4/esp4.c') diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index c6aba234b6e9..91e6a402e22e 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -152,11 +152,10 @@ static void esp_output_restore_header(struct sk_buff *skb) } static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb, + struct xfrm_state *x, struct ip_esp_hdr *esph, struct esp_output_extra *extra) { - struct xfrm_state *x = skb_dst(skb)->xfrm; - /* For ESN we move the header forward by 4 bytes to * accomodate the high bits. We will move it back after * encryption. @@ -198,98 +197,56 @@ static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) tail[plen - 1] = proto; } -static int esp_output(struct xfrm_state *x, struct sk_buff *skb) +static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) { - struct esp_output_extra *extra; - int err = -ENOMEM; - struct ip_esp_hdr *esph; - struct crypto_aead *aead; - struct aead_request *req; - struct scatterlist *sg, *dsg; - struct sk_buff *trailer; - struct page *page; - void *tmp; - u8 *iv; - u8 *tail; - u8 *vaddr; - int blksize; - int clen; - int alen; - int plen; - int ivlen; - int tfclen; - int nfrags; - int assoclen; - int extralen; - int tailen; - __be64 seqno; - __u8 proto = *skb_mac_header(skb); - - /* skb is pure payload to encrypt */ - - aead = x->data; - alen = crypto_aead_authsize(aead); - ivlen = crypto_aead_ivsize(aead); - - tfclen = 0; - if (x->tfcpad) { - struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); - u32 padto; - - padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); - if (skb->len < padto) - tfclen = padto - skb->len; + int encap_type; + struct udphdr *uh; + __be32 *udpdata32; + __be16 sport, dport; + struct xfrm_encap_tmpl *encap = x->encap; + struct ip_esp_hdr *esph = esp->esph; + + spin_lock_bh(&x->lock); + sport = encap->encap_sport; + dport = encap->encap_dport; + encap_type = encap->encap_type; + spin_unlock_bh(&x->lock); + + uh = (struct udphdr *)esph; + uh->source = sport; + uh->dest = dport; + uh->len = htons(skb->len + esp->tailen + - skb_transport_offset(skb)); + uh->check = 0; + + switch (encap_type) { + default: + case UDP_ENCAP_ESPINUDP: + esph = (struct ip_esp_hdr *)(uh + 1); + break; + case UDP_ENCAP_ESPINUDP_NON_IKE: + udpdata32 = (__be32 *)(uh + 1); + udpdata32[0] = udpdata32[1] = 0; + esph = (struct ip_esp_hdr *)(udpdata32 + 2); + break; } - blksize = ALIGN(crypto_aead_blocksize(aead), 4); - clen = ALIGN(skb->len + 2 + tfclen, blksize); - plen = clen - skb->len - tfclen; - tailen = tfclen + plen + alen; - assoclen = sizeof(*esph); - extralen = 0; - if (x->props.flags & XFRM_STATE_ESN) { - extralen += sizeof(*extra); - assoclen += sizeof(__be32); - } + *skb_mac_header(skb) = IPPROTO_UDP; + esp->esph = esph; +} - *skb_mac_header(skb) = IPPROTO_ESP; - esph = ip_esp_hdr(skb); +int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) +{ + u8 *tail; + u8 *vaddr; + int nfrags; + struct page *page; + struct sk_buff *trailer; + int tailen = esp->tailen; /* this is non-NULL only with UDP Encapsulation */ - if (x->encap) { - struct xfrm_encap_tmpl *encap = x->encap; - struct udphdr *uh; - __be32 *udpdata32; - __be16 sport, dport; - int encap_type; - - spin_lock_bh(&x->lock); - sport = encap->encap_sport; - dport = encap->encap_dport; - encap_type = encap->encap_type; - spin_unlock_bh(&x->lock); - - uh = (struct udphdr *)esph; - uh->source = sport; - uh->dest = dport; - uh->len = htons(skb->len + tailen - - skb_transport_offset(skb)); - uh->check = 0; - - switch (encap_type) { - default: - case UDP_ENCAP_ESPINUDP: - esph = (struct ip_esp_hdr *)(uh + 1); - break; - case UDP_ENCAP_ESPINUDP_NON_IKE: - udpdata32 = (__be32 *)(uh + 1); - udpdata32[0] = udpdata32[1] = 0; - esph = (struct ip_esp_hdr *)(udpdata32 + 2); - break; - } - - *skb_mac_header(skb) = IPPROTO_UDP; - } + if (x->encap) + esp_output_udp_encap(x, skb, esp); if (!skb_cloned(skb)) { if (tailen <= skb_availroom(skb)) { @@ -304,6 +261,8 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) struct sock *sk = skb->sk; struct page_frag *pfrag = &x->xfrag; + esp->inplace = false; + allocsize = ALIGN(tailen, L1_CACHE_BYTES); spin_lock_bh(&x->lock); @@ -320,10 +279,12 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) tail = vaddr + pfrag->offset; - esp_output_fill_trailer(tail, tfclen, plen, proto); + esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); kunmap_atomic(vaddr); + spin_unlock_bh(&x->lock); + nfrags = skb_shinfo(skb)->nr_frags; __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, @@ -339,76 +300,56 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) if (sk) atomic_add(tailen, &sk->sk_wmem_alloc); - skb_push(skb, -skb_network_offset(skb)); - - esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); - esph->spi = x->id.spi; - - tmp = esp_alloc_tmp(aead, nfrags + 2, extralen); - if (!tmp) { - spin_unlock_bh(&x->lock); - err = -ENOMEM; - goto error; - } - - extra = esp_tmp_extra(tmp); - iv = esp_tmp_iv(aead, tmp, extralen); - req = esp_tmp_req(aead, iv); - sg = esp_req_sg(aead, req); - dsg = &sg[nfrags]; - - esph = esp_output_set_extra(skb, esph, extra); - - sg_init_table(sg, nfrags); - skb_to_sgvec(skb, sg, - (unsigned char *)esph - skb->data, - assoclen + ivlen + clen + alen); - - allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); - - if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { - spin_unlock_bh(&x->lock); - err = -ENOMEM; - goto error; - } - - skb_shinfo(skb)->nr_frags = 1; - - page = pfrag->page; - get_page(page); - /* replace page frags in skb with new page */ - __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); - pfrag->offset = pfrag->offset + allocsize; - - sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); - skb_to_sgvec(skb, dsg, - (unsigned char *)esph - skb->data, - assoclen + ivlen + clen + alen); - - spin_unlock_bh(&x->lock); - - goto skip_cow2; + goto out; } } cow: - err = skb_cow_data(skb, tailen, &trailer); - if (err < 0) - goto error; - nfrags = err; + nfrags = skb_cow_data(skb, tailen, &trailer); + if (nfrags < 0) + goto out; tail = skb_tail_pointer(trailer); - esph = ip_esp_hdr(skb); skip_cow: - esp_output_fill_trailer(tail, tfclen, plen, proto); + esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); + pskb_put(skb, trailer, tailen); - pskb_put(skb, trailer, clen - skb->len + alen); - skb_push(skb, -skb_network_offset(skb)); - esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); - esph->spi = x->id.spi; +out: + return nfrags; +} +EXPORT_SYMBOL_GPL(esp_output_head); + +int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) +{ + u8 *iv; + int alen; + void *tmp; + int ivlen; + int assoclen; + int extralen; + struct page *page; + struct ip_esp_hdr *esph; + struct crypto_aead *aead; + struct aead_request *req; + struct scatterlist *sg, *dsg; + struct esp_output_extra *extra; + int err = -ENOMEM; + + assoclen = sizeof(struct ip_esp_hdr); + extralen = 0; + + if (x->props.flags & XFRM_STATE_ESN) { + extralen += sizeof(*extra); + assoclen += sizeof(__be32); + } - tmp = esp_alloc_tmp(aead, nfrags, extralen); + aead = x->data; + alen = crypto_aead_authsize(aead); + ivlen = crypto_aead_ivsize(aead); + + tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); if (!tmp) { + spin_unlock_bh(&x->lock); err = -ENOMEM; goto error; } @@ -417,26 +358,58 @@ skip_cow: iv = esp_tmp_iv(aead, tmp, extralen); req = esp_tmp_req(aead, iv); sg = esp_req_sg(aead, req); - dsg = sg; - esph = esp_output_set_extra(skb, esph, extra); + if (esp->inplace) + dsg = sg; + else + dsg = &sg[esp->nfrags]; - sg_init_table(sg, nfrags); + esph = esp_output_set_extra(skb, x, esp->esph, extra); + esp->esph = esph; + + sg_init_table(sg, esp->nfrags); skb_to_sgvec(skb, sg, (unsigned char *)esph - skb->data, - assoclen + ivlen + clen + alen); + assoclen + ivlen + esp->clen + alen); + + if (!esp->inplace) { + int allocsize; + struct page_frag *pfrag = &x->xfrag; + + allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); + + spin_lock_bh(&x->lock); + if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { + spin_unlock_bh(&x->lock); + err = -ENOMEM; + goto error; + } + + skb_shinfo(skb)->nr_frags = 1; + + page = pfrag->page; + get_page(page); + /* replace page frags in skb with new page */ + __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); + pfrag->offset = pfrag->offset + allocsize; + spin_unlock_bh(&x->lock); + + sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); + skb_to_sgvec(skb, dsg, + (unsigned char *)esph - skb->data, + assoclen + ivlen + esp->clen + alen); + } -skip_cow2: if ((x->props.flags & XFRM_STATE_ESN)) aead_request_set_callback(req, 0, esp_output_done_esn, skb); else aead_request_set_callback(req, 0, esp_output_done, skb); - aead_request_set_crypt(req, sg, dsg, ivlen + clen, iv); + aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); aead_request_set_ad(req, assoclen); memset(iv, 0, ivlen); - memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8), + memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), min(ivlen, 8)); ESP_SKB_CB(skb)->tmp = tmp; @@ -462,8 +435,59 @@ skip_cow2: error: return err; } +EXPORT_SYMBOL_GPL(esp_output_tail); + +static int esp_output(struct xfrm_state *x, struct sk_buff *skb) +{ + int alen; + int blksize; + struct ip_esp_hdr *esph; + struct crypto_aead *aead; + struct esp_info esp; + + esp.inplace = true; + + esp.proto = *skb_mac_header(skb); + *skb_mac_header(skb) = IPPROTO_ESP; + + /* skb is pure payload to encrypt */ + + aead = x->data; + alen = crypto_aead_authsize(aead); + + esp.tfclen = 0; + if (x->tfcpad) { + struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); + u32 padto; + + padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); + if (skb->len < padto) + esp.tfclen = padto - skb->len; + } + blksize = ALIGN(crypto_aead_blocksize(aead), 4); + esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); + esp.plen = esp.clen - skb->len - esp.tfclen; + esp.tailen = esp.tfclen + esp.plen + alen; + + esp.esph = ip_esp_hdr(skb); + + esp.nfrags = esp_output_head(x, skb, &esp); + if (esp.nfrags < 0) + return esp.nfrags; + + esph = esp.esph; + esph->spi = x->id.spi; + + esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); + esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + + ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); + + skb_push(skb, -skb_network_offset(skb)); + + return esp_output_tail(x, skb, &esp); +} -static int esp_input_done2(struct sk_buff *skb, int err) +int esp_input_done2(struct sk_buff *skb, int err) { const struct iphdr *iph; struct xfrm_state *x = xfrm_input_state(skb); @@ -548,6 +572,7 @@ static int esp_input_done2(struct sk_buff *skb, int err) out: return err; } +EXPORT_SYMBOL_GPL(esp_input_done2); static void esp_input_done(struct crypto_async_request *base, int err) { @@ -930,7 +955,7 @@ static const struct xfrm_type esp_type = .destructor = esp_destroy, .get_mtu = esp4_get_mtu, .input = esp_input, - .output = esp_output + .output = esp_output, }; static struct xfrm4_protocol esp4_protocol = { -- cgit v1.2.3