cregit-Linux how code gets into the kernel

Release 4.8 net/ipv4/esp4.c

Directory: net/ipv4

#define pr_fmt(fmt) "IPsec: " fmt

#include <crypto/aead.h>
#include <crypto/authenc.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/esp.h>
#include <linux/scatterlist.h>
#include <linux/kernel.h>
#include <linux/pfkeyv2.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/in6.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <net/udp.h>


struct esp_skb_cb {
	
struct xfrm_skb_cb xfrm;
	
void *tmp;
};


struct esp_output_extra {
	
__be32 seqhi;
	
u32 esphoff;
};


#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))

static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);

/*
 * Allocate an AEAD request structure with extra space for SG and IV.
 *
 * For alignment considerations the IV is placed at the front, followed
 * by the request and finally the SG list.
 *
 * TODO: Use spare space in skb for this where possible.
 */

static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen) { unsigned int len; len = extralen; len += crypto_aead_ivsize(aead); if (len) { len += crypto_aead_alignmask(aead) & ~(crypto_tfm_ctx_alignment() - 1); len = ALIGN(len, crypto_tfm_ctx_alignment()); } len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); len = ALIGN(len, __alignof__(struct scatterlist)); len += sizeof(struct scatterlist) * nfrags; return kmalloc(len, GFP_ATOMIC); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu8679.63%555.56%
alexey kuznetsovalexey kuznetsov1513.89%111.11%
steffen klassertsteffen klassert54.63%111.11%
james morrisjames morris10.93%111.11%
arnaldo carvalho de meloarnaldo carvalho de melo10.93%111.11%
Total108100.00%9100.00%


static inline void *esp_tmp_extra(void *tmp) { return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra)); }

Contributors

PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert2083.33%150.00%
herbert xuherbert xu416.67%150.00%
Total24100.00%2100.00%


static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen) { return crypto_aead_ivsize(aead) ? PTR_ALIGN((u8 *)tmp + extralen, crypto_aead_alignmask(aead) + 1) : tmp + extralen; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu4083.33%240.00%
steffen klassertsteffen klassert48.33%120.00%
alexey kuznetsovalexey kuznetsov24.17%120.00%
arnaldo carvalho de meloarnaldo carvalho de melo24.17%120.00%
Total48100.00%5100.00%


static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) { struct aead_request *req; req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), crypto_tfm_ctx_alignment()); aead_request_set_tfm(req, aead); return req; }

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PersonTokensPropCommitsCommitProp
herbert xuherbert xu52100.00%1100.00%
Total52100.00%1100.00%


static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, struct aead_request *req) { return (void *)ALIGN((unsigned long)(req + 1) + crypto_aead_reqsize(aead), __alignof__(struct scatterlist)); }

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PersonTokensPropCommitsCommitProp
herbert xuherbert xu48100.00%1100.00%
Total48100.00%1100.00%


static void esp_output_done(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; kfree(ESP_SKB_CB(skb)->tmp); xfrm_output_resume(skb, err); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu40100.00%2100.00%
Total40100.00%2100.00%

/* Move ESP header back into place. */
static void esp_restore_header(struct sk_buff *skb, unsigned int offset) { struct ip_esp_hdr *esph = (void *)(skb->data + offset); void *tmp = ESP_SKB_CB(skb)->tmp; __be32 *seqhi = esp_tmp_extra(tmp); esph->seq_no = esph->spi; esph->spi = *seqhi; }

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PersonTokensPropCommitsCommitProp
herbert xuherbert xu67100.00%3100.00%
Total67100.00%3100.00%


static void esp_output_restore_header(struct sk_buff *skb) { void *tmp = ESP_SKB_CB(skb)->tmp; struct esp_output_extra *extra = esp_tmp_extra(tmp); esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - sizeof(__be32)); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu51100.00%3100.00%
Total51100.00%3100.00%


static void esp_output_done_esn(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; esp_output_restore_header(skb); esp_output_done(base, err); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu35100.00%2100.00%
Total35100.00%2100.00%


static int esp_output(struct xfrm_state *x, struct sk_buff *skb) { int err; struct esp_output_extra *extra; struct ip_esp_hdr *esph; struct crypto_aead *aead; struct aead_request *req; struct scatterlist *sg; struct sk_buff *trailer; void *tmp; u8 *iv; u8 *tail; int blksize; int clen; int alen; int plen; int ivlen; int tfclen; int nfrags; int assoclen; int extralen; __be64 seqno; /* 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; } blksize = ALIGN(crypto_aead_blocksize(aead), 4); clen = ALIGN(skb->len + 2 + tfclen, blksize); plen = clen - skb->len - tfclen; err = skb_cow_data(skb, tfclen + plen + alen, &trailer); if (err < 0) goto error; nfrags = err; assoclen = sizeof(*esph); extralen = 0; if (x->props.flags & XFRM_STATE_ESN) { extralen += sizeof(*extra); assoclen += sizeof(__be32); } tmp = esp_alloc_tmp(aead, nfrags, extralen); if (!tmp) { 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); /* Fill padding... */ tail = skb_tail_pointer(trailer); if (tfclen) { memset(tail, 0, tfclen); tail += tfclen; } do { int i; for (i = 0; i < plen - 2; i++) tail[i] = i + 1; } while (0); tail[plen - 2] = plen - 2; tail[plen - 1] = *skb_mac_header(skb); pskb_put(skb, trailer, clen - skb->len + alen); skb_push(skb, -skb_network_offset(skb)); esph = ip_esp_hdr(skb); *skb_mac_header(skb) = IPPROTO_ESP; /* 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 - 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; } esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); aead_request_set_callback(req, 0, esp_output_done, skb); /* For ESN we move the header forward by 4 bytes to * accomodate the high bits. We will move it back after * encryption. */ if ((x->props.flags & XFRM_STATE_ESN)) { extra->esphoff = (unsigned char *)esph - skb_transport_header(skb); esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); extra->seqhi = esph->spi; esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi); aead_request_set_callback(req, 0, esp_output_done_esn, skb); } esph->spi = x->id.spi; sg_init_table(sg, nfrags); skb_to_sgvec(skb, sg, (unsigned char *)esph - skb->data, assoclen + ivlen + clen + alen); aead_request_set_crypt(req, sg, sg, ivlen + clen, iv); aead_request_set_ad(req, assoclen); seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); memset(iv, 0, ivlen); memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8), min(ivlen, 8)); ESP_SKB_CB(skb)->tmp = tmp; err = crypto_aead_encrypt(req); switch (err) { case -EINPROGRESS: goto error; case -EBUSY: err = NET_XMIT_DROP; break; case 0: if ((x->props.flags & XFRM_STATE_ESN)) esp_output_restore_header(skb); } kfree(tmp); error: return err; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu64065.11%1350.00%
martin willimartin willi11511.70%13.85%
steffen klassertsteffen klassert888.95%27.69%
alexey kuznetsovalexey kuznetsov848.55%13.85%
derek atkinsderek atkins343.46%13.85%
arnaldo carvalho de meloarnaldo carvalho de melo80.81%27.69%
wei yongjunwei yongjun70.71%13.85%
al viroal viro30.31%27.69%
david s. millerdavid s. miller20.20%13.85%
james morrisjames morris10.10%13.85%
mathias krausemathias krause10.10%13.85%
Total983100.00%26100.00%


static int esp_input_done2(struct sk_buff *skb, int err) { const struct iphdr *iph; struct xfrm_state *x = xfrm_input_state(skb); struct crypto_aead *aead = x->data; int alen = crypto_aead_authsize(aead); int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); int elen = skb->len - hlen; int ihl; u8 nexthdr[2]; int padlen; kfree(ESP_SKB_CB(skb)->tmp); if (unlikely(err)) goto out; if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) BUG(); err = -EINVAL; padlen = nexthdr[0]; if (padlen + 2 + alen >= elen) goto out; /* ... check padding bits here. Silly. :-) */ iph = ip_hdr(skb); ihl = iph->ihl * 4; if (x->encap) { struct xfrm_encap_tmpl *encap = x->encap; struct udphdr *uh = (void *)(skb_network_header(skb) + 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) skb->ip_summed = CHECKSUM_UNNECESSARY; } pskb_trim(skb, skb->len - alen - padlen - 2); __skb_pull(skb, hlen); if (x->props.mode == XFRM_MODE_TUNNEL) skb_reset_transport_header(skb); else skb_set_transport_header(skb, -ihl); err = nexthdr[1]; /* RFC4303: Drop dummy packets without any error */ if (err == IPPROTO_NONE) err = -EINVAL; out: return err; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu24472.62%952.94%
alexey kuznetsovalexey kuznetsov6519.35%15.88%
li rongqingli rongqing164.76%15.88%
hideaki yoshifujihideaki yoshifuji30.89%15.88%
mathias krausemathias krause20.60%15.88%
david s. millerdavid s. miller20.60%15.88%
derek atkinsderek atkins20.60%15.88%
patrick mchardypatrick mchardy10.30%15.88%
eric dumazeteric dumazet10.30%15.88%
Total336100.00%17100.00%


static void esp_input_done(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; xfrm_input_resume(skb, esp_input_done2(skb, err)); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu35100.00%1100.00%
Total35100.00%1100.00%


static void esp_input_restore_header(struct sk_buff *skb) { esp_restore_header(skb, 0); __skb_pull(skb, 4); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu25100.00%2100.00%
Total25100.00%2100.00%


static void esp_input_done_esn(struct crypto_async_request *base, int err) { struct sk_buff *skb = base->data; esp_input_restore_header(skb); esp_input_done(base, err); }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu3188.57%250.00%
david s. millerdavid s. miller38.57%125.00%
alexey kuznetsovalexey kuznetsov12.86%125.00%
Total35100.00%4100.00%

/* * 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 ip_esp_hdr *esph; struct crypto_aead *aead = x->data; struct aead_request *req; struct sk_buff *trailer; int ivlen = crypto_aead_ivsize(aead); int elen = skb->len - sizeof(*esph) - ivlen; int nfrags; int assoclen; int seqhilen; __be32 *seqhi; void *tmp; u8 *iv; struct scatterlist *sg; int err = -EINVAL; if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) goto out; if (elen <= 0) goto out; err = skb_cow_data(skb, 0, &trailer); if (err < 0) goto out; nfrags = err; assoclen = sizeof(*esph); seqhilen = 0; if (x->props.flags & XFRM_STATE_ESN) { seqhilen += sizeof(__be32); assoclen += seqhilen; } err = -ENOMEM; tmp = esp_alloc_tmp(aead, nfrags, seqhilen); if (!tmp) goto out; ESP_SKB_CB(skb)->tmp = tmp; seqhi = esp_tmp_extra(tmp); iv = esp_tmp_iv(aead, tmp, seqhilen); req = esp_tmp_req(aead, iv); sg = esp_req_sg(aead, req); skb->ip_summed = CHECKSUM_NONE; esph = (struct ip_esp_hdr *)skb->data; aead_request_set_callback(req, 0, esp_input_done, skb); /* For ESN we move the header forward by 4 bytes to * accomodate the high bits. We will move it back after * decryption. */ if ((x->props.flags & XFRM_STATE_ESN)) { esph = (void *)skb_push(skb, 4); *seqhi = esph->spi; esph->spi = esph->seq_no; esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.input.hi); aead_request_set_callback(req, 0, esp_input_done_esn, skb); } sg_init_table(sg, nfrags); skb_to_sgvec(skb, sg, 0, skb->len); aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); aead_request_set_ad(req, assoclen); err = crypto_aead_decrypt(req); if (err == -EINPROGRESS) goto out; if ((x->props.flags & XFRM_STATE_ESN)) esp_input_restore_header(skb); err = esp_input_done2(skb, err); out: return err; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu29666.97%844.44%
steffen klassertsteffen klassert9621.72%15.56%
alexey kuznetsovalexey kuznetsov245.43%15.56%
arnaldo carvalho de meloarnaldo carvalho de melo71.58%211.11%
thomas grafthomas graf71.58%211.11%
derek atkinsderek atkins51.13%15.56%
fabian frederickfabian frederick40.90%15.56%
mathias krausemathias krause20.45%15.56%
david s. millerdavid s. miller10.23%15.56%
Total442100.00%18100.00%


static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) { struct crypto_aead *aead = x->data; u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); unsigned int net_adj; switch (x->props.mode) { case XFRM_MODE_TRANSPORT: case XFRM_MODE_BEET: net_adj = sizeof(struct iphdr); break; case XFRM_MODE_TUNNEL: net_adj = 0; break; default: BUG(); } return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - net_adj) & ~(blksize - 1)) + net_adj - 2; }

Contributors

PersonTokensPropCommitsCommitProp
benjamin poirierbenjamin poirier4339.81%112.50%
alexey kuznetsovalexey kuznetsov3936.11%112.50%
diego beltramidiego beltrami1211.11%112.50%
herbert xuherbert xu76.48%225.00%
patrick mchardypatrick mchardy43.70%112.50%
mathias krausemathias krause32.78%225.00%
Total108100.00%8100.00%


static int esp4_err(struct sk_buff *skb, u32 info) { struct net *net = dev_net(skb->dev); const struct iphdr *iph = (const struct iphdr *)skb->data; struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); struct xfrm_state *x; switch (icmp_hdr(skb)->type) { case ICMP_DEST_UNREACH: if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) return 0; case ICMP_REDIRECT: break; default: return 0; } x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET); if (!x) return 0; if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0); else ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0); xfrm_state_put(x); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
alexey kuznetsovalexey kuznetsov9347.45%19.09%
david s. millerdavid s. miller5427.55%218.18%
alexey dobriyanalexey dobriyan147.14%218.18%
steffen klassertsteffen klassert136.63%19.09%
hideaki yoshifujihideaki yoshifuji84.08%19.09%
arnaldo carvalho de meloarnaldo carvalho de melo63.06%19.09%
jamal hadi salimjamal hadi salim42.04%19.09%
eric dumazeteric dumazet31.53%19.09%
patrick mchardypatrick mchardy10.51%19.09%
Total196100.00%11100.00%


static void esp_destroy(struct xfrm_state *x) { struct crypto_aead *aead = x->data; if (!aead) return; crypto_free_aead(aead); }

Contributors

PersonTokensPropCommitsCommitProp
alexey kuznetsovalexey kuznetsov1961.29%116.67%
herbert xuherbert xu516.13%233.33%
mathias krausemathias krause39.68%116.67%
david s. millerdavid s. miller39.68%116.67%
patrick mchardypatrick mchardy13.23%116.67%
Total31100.00%6100.00%


static int esp_init_aead(struct xfrm_state *x) { char aead_name[CRYPTO_MAX_ALG_NAME]; struct crypto_aead *aead; int err; err = -ENAMETOOLONG; if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) goto error; aead = crypto_alloc_aead(aead_name, 0, 0); err = PTR_ERR(aead); if (IS_ERR(aead)) goto error; x->data = aead; err = crypto_aead_setkey(aead, x->aead->alg_key, (x->aead->alg_key_len + 7) / 8); if (err) goto error; err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); if (err) goto error; error: return err; }

Contributors

PersonTokensPropCommitsCommitProp
herbert xuherbert xu13791.95%240.00%
alexey kuznetsovalexey kuznetsov96.04%120.00%
mathias krausemathias krause21.34%120.00%
patrick mchardypatrick mchardy10.67%120.00%
Total149100.00%5100.00%


static int esp_init_authenc(struct xfrm_state *x) { struct crypto_aead *aead; struct crypto_authenc_key_param *param; struct rtattr *rta; char *key; char *p; char authenc_name[CRYPTO_MAX_ALG_NAME]; unsigned int keylen