cregit-Linux how code gets into the kernel

Release 4.8 net/ipv4/ah4.c

Directory: net/ipv4

#define pr_fmt(fmt) "IPsec: " fmt

#include <crypto/hash.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ah.h>
#include <linux/crypto.h>
#include <linux/pfkeyv2.h>
#include <linux/scatterlist.h>
#include <net/icmp.h>
#include <net/protocol.h>


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


#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))


static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags, unsigned int size) { unsigned int len; len = size + crypto_ahash_digestsize(ahash) + (crypto_ahash_alignmask(ahash) & ~(crypto_tfm_ctx_alignment() - 1)); len = ALIGN(len, crypto_tfm_ctx_alignment()); len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); len = ALIGN(len, __alignof__(struct scatterlist)); len += sizeof(struct scatterlist) * nfrags; return kmalloc(len, GFP_ATOMIC); }

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PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert101100.00%1100.00%
Total101100.00%1100.00%


static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset) { return tmp + offset; }

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PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert21100.00%1100.00%
Total21100.00%1100.00%


static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp, unsigned int offset) { return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1); }

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PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert40100.00%1100.00%
Total40100.00%1100.00%


static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, u8 *icv) { struct ahash_request *req; req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), crypto_tfm_ctx_alignment()); ahash_request_set_tfm(req, ahash); return req; }

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PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert52100.00%1100.00%
Total52100.00%1100.00%


static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, struct ahash_request *req) { return (void *)ALIGN((unsigned long)(req + 1) + crypto_ahash_reqsize(ahash), __alignof__(struct scatterlist)); }

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PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert48100.00%1100.00%
Total48100.00%1100.00%

/* Clear mutable options and find final destination to substitute * into IP header for icv calculation. Options are already checked * for validity, so paranoia is not required. */
static int ip_clear_mutable_options(const struct iphdr *iph, __be32 *daddr) { unsigned char *optptr = (unsigned char *)(iph+1); int l = iph->ihl*4 - sizeof(struct iphdr); int optlen; while (l > 0) { switch (*optptr) { case IPOPT_END: return 0; case IPOPT_NOOP: l--; optptr++; continue; } optlen = optptr[1]; if (optlen<2 || optlen>l) return -EINVAL; switch (*optptr) { case IPOPT_SEC: case 0x85: /* Some "Extended Security" crap. */ case IPOPT_CIPSO: case IPOPT_RA: case 0x80|21: /* RFC1770 */ break; case IPOPT_LSRR: case IPOPT_SSRR: if (optlen < 6) return -EINVAL; memcpy(daddr, optptr+optlen-4, 4); /* Fall through */ default: memset(optptr, 0, optlen); } l -= optlen; optptr += optlen; } return 0; }

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PersonTokensPropCommitsCommitProp
alexey kuznetsovalexey kuznetsov17195.00%116.67%
tom lendackytom lendacky52.78%116.67%
paul moorepaul moore10.56%116.67%
james morrisjames morris10.56%116.67%
al viroal viro10.56%116.67%
eric dumazeteric dumazet10.56%116.67%
Total180100.00%6100.00%


static void ah_output_done(struct crypto_async_request *base, int err) { u8 *icv; struct iphdr *iph; struct sk_buff *skb = base->data; struct xfrm_state *x = skb_dst(skb)->xfrm; struct ah_data *ahp = x->data; struct iphdr *top_iph = ip_hdr(skb); struct ip_auth_hdr *ah = ip_auth_hdr(skb); int ihl = ip_hdrlen(skb); iph = AH_SKB_CB(skb)->tmp; icv = ah_tmp_icv(ahp->ahash, iph, ihl); memcpy(ah->auth_data, icv, ahp->icv_trunc_len); top_iph->tos = iph->tos; top_iph->ttl = iph->ttl; top_iph->frag_off = iph->frag_off; if (top_iph->ihl != 5) { top_iph->daddr = iph->daddr; memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); } kfree(AH_SKB_CB(skb)->tmp); xfrm_output_resume(skb, err); }

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PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert10452.53%19.09%
alexey kuznetsovalexey kuznetsov5527.78%218.18%
herbert xuherbert xu3618.18%654.55%
arnaldo carvalho de meloarnaldo carvalho de melo21.01%19.09%
james morrisjames morris10.51%19.09%
Total198100.00%11100.00%


static int ah_output(struct xfrm_state *x, struct sk_buff *skb) { int err; int nfrags; int ihl; u8 *icv; struct sk_buff *trailer; struct crypto_ahash *ahash; struct ahash_request *req; struct scatterlist *sg; struct iphdr *iph, *top_iph; struct ip_auth_hdr *ah; struct ah_data *ahp; int seqhi_len = 0; __be32 *seqhi; int sglists = 0; struct scatterlist *seqhisg; ahp = x->data; ahash = ahp->ahash; if ((err = skb_cow_data(skb, 0, &trailer)) < 0) goto out; nfrags = err; skb_push(skb, -skb_network_offset(skb)); ah = ip_auth_hdr(skb); ihl = ip_hdrlen(skb); if (x->props.flags & XFRM_STATE_ESN) { sglists = 1; seqhi_len = sizeof(*seqhi); } err = -ENOMEM; iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + seqhi_len); if (!iph) goto out; seqhi = (__be32 *)((char *)iph + ihl); icv = ah_tmp_icv(ahash, seqhi, seqhi_len); req = ah_tmp_req(ahash, icv); sg = ah_req_sg(ahash, req); seqhisg = sg + nfrags; memset(ah->auth_data, 0, ahp->icv_trunc_len); top_iph = ip_hdr(skb); iph->tos = top_iph->tos; iph->ttl = top_iph->ttl; iph->frag_off = top_iph->frag_off; if (top_iph->ihl != 5) { iph->daddr = top_iph->daddr; memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); err = ip_clear_mutable_options(top_iph, &top_iph->daddr); if (err) goto out_free; } ah->nexthdr = *skb_mac_header(skb); *skb_mac_header(skb) = IPPROTO_AH; top_iph->tos = 0; top_iph->tot_len = htons(skb->len); top_iph->frag_off = 0; top_iph->ttl = 0; top_iph->check = 0; if (x->props.flags & XFRM_STATE_ALIGN4) ah->hdrlen = (XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; else ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; ah->reserved = 0; ah->spi = x->id.spi; ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); sg_init_table(sg, nfrags + sglists); skb_to_sgvec_nomark(skb, sg, 0, skb->len); if (x->props.flags & XFRM_STATE_ESN) { /* Attach seqhi sg right after packet payload */ *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); sg_set_buf(seqhisg, seqhi, seqhi_len); } ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); ahash_request_set_callback(req, 0, ah_output_done, skb); AH_SKB_CB(skb)->tmp = iph; err = crypto_ahash_digest(req); if (err) { if (err == -EINPROGRESS) goto out; if (err == -EBUSY) err = NET_XMIT_DROP; goto out_free; } memcpy(ah->auth_data, icv, ahp->icv_trunc_len); top_iph->tos = iph->tos; top_iph->ttl = iph->ttl; top_iph->frag_off = iph->frag_off; if (top_iph->ihl != 5) { top_iph->daddr = iph->daddr; memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr)); } out_free: kfree(iph); out: return err; }

Contributors

PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert52372.44%220.00%
fan dufan du11515.93%110.00%
nicolas dichtelnicolas dichtel344.71%110.00%
herbert xuherbert xu253.46%330.00%
alexey kuznetsovalexey kuznetsov212.91%110.00%
james morrisjames morris20.28%110.00%
hideaki yoshifujihideaki yoshifuji20.28%110.00%
Total722100.00%10100.00%


static void ah_input_done(struct crypto_async_request *base, int err) { u8 *auth_data; u8 *icv; struct iphdr *work_iph; struct sk_buff *skb = base->data; struct xfrm_state *x = xfrm_input_state(skb); struct ah_data *ahp = x->data; struct ip_auth_hdr *ah = ip_auth_hdr(skb); int ihl = ip_hdrlen(skb); int ah_hlen = (ah->hdrlen + 2) << 2; work_iph = AH_SKB_CB(skb)->tmp; auth_data = ah_tmp_auth(work_iph, ihl); icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; if (err) goto out; err = ah->nexthdr; skb->network_header += ah_hlen; memcpy(skb_network_header(skb), work_iph, ihl); __skb_pull(skb, ah_hlen + ihl); if (x->props.mode == XFRM_MODE_TUNNEL) skb_reset_transport_header(skb); else skb_set_transport_header(skb, -ihl); out: kfree(AH_SKB_CB(skb)->tmp); xfrm_input_resume(skb, err); }

Contributors

PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert14967.73%19.09%
herbert xuherbert xu2310.45%436.36%
alexey kuznetsovalexey kuznetsov2210.00%218.18%
li rongqingli rongqing167.27%19.09%
nick bowlernick bowler62.73%19.09%
tom lendackytom lendacky20.91%19.09%
jamal hadi salimjamal hadi salim20.91%19.09%
Total220100.00%11100.00%


static int ah_input(struct xfrm_state *x, struct sk_buff *skb) { int ah_hlen; int ihl; int nexthdr; int nfrags; u8 *auth_data; u8 *icv; struct sk_buff *trailer; struct crypto_ahash *ahash; struct ahash_request *req; struct scatterlist *sg; struct iphdr *iph, *work_iph; struct ip_auth_hdr *ah; struct ah_data *ahp; int err = -ENOMEM; int seqhi_len = 0; __be32 *seqhi; int sglists = 0; struct scatterlist *seqhisg; if (!pskb_may_pull(skb, sizeof(*ah))) goto out; ah = (struct ip_auth_hdr *)skb->data; ahp = x->data; ahash = ahp->ahash; nexthdr = ah->nexthdr; ah_hlen = (ah->hdrlen + 2) << 2; if (x->props.flags & XFRM_STATE_ALIGN4) { if (ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_full_len) && ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len)) goto out; } else { if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) goto out; } if (!pskb_may_pull(skb, ah_hlen)) goto out; /* We are going to _remove_ AH header to keep sockets happy, * so... Later this can change. */ if (skb_unclone(skb, GFP_ATOMIC)) goto out; skb->ip_summed = CHECKSUM_NONE; if ((err = skb_cow_data(skb, 0, &trailer)) < 0) goto out; nfrags = err; ah = (struct ip_auth_hdr *)skb->data; iph = ip_hdr(skb); ihl = ip_hdrlen(skb); if (x->props.flags & XFRM_STATE_ESN) { sglists = 1; seqhi_len = sizeof(*seqhi); } work_iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + ahp->icv_trunc_len + seqhi_len); if (!work_iph) { err = -ENOMEM; goto out; } seqhi = (__be32 *)((char *)work_iph + ihl); auth_data = ah_tmp_auth(seqhi, seqhi_len); icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len); req = ah_tmp_req(ahash, icv); sg = ah_req_sg(ahash, req); seqhisg = sg + nfrags; memcpy(work_iph, iph, ihl); memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); memset(ah->auth_data, 0, ahp->icv_trunc_len); iph->ttl = 0; iph->tos = 0; iph->frag_off = 0; iph->check = 0; if (ihl > sizeof(*iph)) { __be32 dummy; err = ip_clear_mutable_options(iph, &dummy); if (err) goto out_free; } skb_push(skb, ihl); sg_init_table(sg, nfrags + sglists); skb_to_sgvec_nomark(skb, sg, 0, skb->len); if (x->props.flags & XFRM_STATE_ESN) { /* Attach seqhi sg right after packet payload */ *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; sg_set_buf(seqhisg, seqhi, seqhi_len); } ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); ahash_request_set_callback(req, 0, ah_input_done, skb); AH_SKB_CB(skb)->tmp = work_iph; err = crypto_ahash_digest(req); if (err) { if (err == -EINPROGRESS) goto out; goto out_free; } err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; if (err) goto out_free; skb->network_header += ah_hlen; memcpy(skb_network_header(skb), work_iph, ihl); __skb_pull(skb, ah_hlen + ihl); if (x->props.mode == XFRM_MODE_TUNNEL) skb_reset_transport_header(skb); else skb_set_transport_header(skb, -ihl); err = nexthdr; out_free: kfree (work_iph); out: return err; }

Contributors

PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert23731.47%14.55%
alexey kuznetsovalexey kuznetsov21128.02%14.55%
fan dufan du11214.87%14.55%
nicolas dichtelnicolas dichtel506.64%14.55%
herbert xuherbert xu476.24%627.27%
dang hongwudang hongwu253.32%14.55%
james morrisjames morris243.19%14.55%
li rongqingli rongqing162.12%14.55%
arnaldo carvalho de meloarnaldo carvalho de melo111.46%313.64%
david s. millerdavid s. miller91.20%29.09%
hideaki yoshifujihideaki yoshifuji81.06%14.55%
pravin b shelarpravin b shelar10.13%14.55%
patrick mchardypatrick mchardy10.13%14.55%
al viroal viro10.13%14.55%
Total753100.00%22100.00%


static int ah4_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_auth_hdr *ah = (struct ip_auth_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, ah->spi, IPPROTO_AH, AF_INET); if (!x) return 0; if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0); else ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 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 int ah_init_state(struct xfrm_state *x) { struct ah_data *ahp = NULL; struct xfrm_algo_desc *aalg_desc; struct crypto_ahash *ahash; if (!x->aalg) goto error; if (x->encap) goto error; ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); if (!ahp) return -ENOMEM; ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); if (IS_ERR(ahash)) goto error; ahp->ahash = ahash; if (crypto_ahash_setkey(ahash, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8)) goto error; /* * Lookup the algorithm description maintained by xfrm_algo, * verify crypto transform properties, and store information * we need for AH processing. This lookup cannot fail here * after a successful crypto_alloc_ahash(). */ aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); BUG_ON(!aalg_desc); if (aalg_desc->uinfo.auth.icv_fullbits/8 != crypto_ahash_digestsize(ahash)) { pr_info("%s: %s digestsize %u != %hu\n", __func__, x->aalg->alg_name, crypto_ahash_digestsize(ahash), aalg_desc->uinfo.auth.icv_fullbits / 8); goto error; } ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; if (x->props.flags & XFRM_STATE_ALIGN4) x->props.header_len = XFRM_ALIGN4(sizeof(struct ip_auth_hdr) + ahp->icv_trunc_len); else x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + ahp->icv_trunc_len); if (x->props.mode == XFRM_MODE_TUNNEL) x->props.header_len += sizeof(struct iphdr); x->data = ahp; return 0; error: if (ahp) { crypto_free_ahash(ahp->ahash); kfree(ahp); } return -EINVAL; }

Contributors

PersonTokensPropCommitsCommitProp
alexey kuznetsovalexey kuznetsov10933.23%15.88%
james morrisjames morris8525.91%15.88%
herbert xuherbert xu5416.46%529.41%
nicolas dichtelnicolas dichtel309.15%15.88%
steffen klassertsteffen klassert185.49%15.88%
david s. millerdavid s. miller103.05%15.88%
hideaki yoshifujihideaki yoshifuji61.83%15.88%
tom lendackytom lendacky51.52%15.88%
joe perchesjoe perches41.22%211.76%
martin willimartin willi41.22%15.88%
masahide nakamuramasahide nakamura20.61%15.88%
panagiotis issaris*panagiotis issaris*10.30%15.88%
Total328100.00%17100.00%


static void ah_destroy(struct xfrm_state *x) { struct ah_data *ahp = x->data; if (!ahp) return; crypto_free_ahash(ahp->ahash); kfree(ahp); }

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PersonTokensPropCommitsCommitProp
alexey kuznetsovalexey kuznetsov2668.42%120.00%
james morrisjames morris615.79%240.00%
herbert xuherbert xu410.53%120.00%
steffen klassertsteffen klassert25.26%120.00%
Total38100.00%5100.00%


static int ah4_rcv_cb(struct sk_buff *skb, int err) { return 0; }

Contributors

PersonTokensPropCommitsCommitProp
steffen klassertsteffen klassert17100.00%1100.00%
Total17100.00%1100.00%

static const struct xfrm_type ah_type = { .description = "AH4", .owner = THIS_MODULE, .proto = IPPROTO_AH