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android-kvm / linux / 0338cd9c22d1bce7dc4a6641d4215a50f476f429 / . / net / ipv4 / tcp_ao.c
blob: db6516092daf5b180fb75482fb711f226451a647 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* INET An implementation of the TCP Authentication Option (TCP-AO).
* See RFC5925.
*
* Authors: Dmitry Safonov <dima@arista.com>
* Francesco Ruggeri <fruggeri@arista.com>
* Salam Noureddine <noureddine@arista.com>
*/
#define pr_fmt(fmt) "TCP: " fmt
#include <crypto/hash.h>
#include <linux/inetdevice.h>
#include <linux/tcp.h>
#include <net/tcp.h>
#include <net/ipv6.h>
#include <net/icmp.h>
#include <trace/events/tcp.h>
DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ);
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp)
{
struct scatterlist sg;
int ret;
if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp->req),
mkt->key, mkt->keylen))
goto clear_hash;
ret = crypto_ahash_init(hp->req);
if (ret)
goto clear_hash;
sg_init_one(&sg, ctx, len);
ahash_request_set_crypt(hp->req, &sg, key, len);
crypto_ahash_update(hp->req);
ret = crypto_ahash_final(hp->req);
if (ret)
goto clear_hash;
return 0;
clear_hash:
memset(key, 0, tcp_ao_digest_size(mkt));
return 1;
}
bool tcp_ao_ignore_icmp(const struct sock *sk, int family, int type, int code)
{
bool ignore_icmp = false;
struct tcp_ao_info *ao;
if (!static_branch_unlikely(&tcp_ao_needed.key))
return false;
/* RFC5925, 7.8:
* >> A TCP-AO implementation MUST default to ignore incoming ICMPv4
* messages of Type 3 (destination unreachable), Codes 2-4 (protocol
* unreachable, port unreachable, and fragmentation needed -- ’hard
* errors’), and ICMPv6 Type 1 (destination unreachable), Code 1
* (administratively prohibited) and Code 4 (port unreachable) intended
* for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN-
* WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs.
*/
if (family == AF_INET) {
if (type != ICMP_DEST_UNREACH)
return false;
if (code < ICMP_PROT_UNREACH || code > ICMP_FRAG_NEEDED)
return false;
} else {
if (type != ICMPV6_DEST_UNREACH)
return false;
if (code != ICMPV6_ADM_PROHIBITED && code != ICMPV6_PORT_UNREACH)
return false;
}
rcu_read_lock();
switch (sk->sk_state) {
case TCP_TIME_WAIT:
ao = rcu_dereference(tcp_twsk(sk)->ao_info);
break;
case TCP_SYN_SENT:
case TCP_SYN_RECV:
case TCP_LISTEN:
case TCP_NEW_SYN_RECV:
/* RFC5925 specifies to ignore ICMPs *only* on connections
* in synchronized states.
*/
rcu_read_unlock();
return false;
default:
ao = rcu_dereference(tcp_sk(sk)->ao_info);
}
if (ao && !ao->accept_icmps) {
ignore_icmp = true;
__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAODROPPEDICMPS);
atomic64_inc(&ao->counters.dropped_icmp);
}
rcu_read_unlock();
return ignore_icmp;
}
/* Optimized version of tcp_ao_do_lookup(): only for sockets for which
* it's known that the keys in ao_info are matching peer's
* family/address/VRF/etc.
*/
struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
int sndid, int rcvid)
{
struct tcp_ao_key *key;
hlist_for_each_entry_rcu(key, &ao->head, node) {
if ((sndid >= 0 && key->sndid != sndid) ||
(rcvid >= 0 && key->rcvid != rcvid))
continue;
return key;
}
return NULL;
}
static int ipv4_prefix_cmp(const struct in_addr *addr1,
const struct in_addr *addr2,
unsigned int prefixlen)
{
__be32 mask = inet_make_mask(prefixlen);
__be32 a1 = addr1->s_addr & mask;
__be32 a2 = addr2->s_addr & mask;
if (a1 == a2)
return 0;
return memcmp(&a1, &a2, sizeof(a1));
}
static int __tcp_ao_key_cmp(const struct tcp_ao_key *key, int l3index,
const union tcp_ao_addr *addr, u8 prefixlen,
int family, int sndid, int rcvid)
{
if (sndid >= 0 && key->sndid != sndid)
return (key->sndid > sndid) ? 1 : -1;
if (rcvid >= 0 && key->rcvid != rcvid)
return (key->rcvid > rcvid) ? 1 : -1;
if (l3index >= 0 && (key->keyflags & TCP_AO_KEYF_IFINDEX)) {
if (key->l3index != l3index)
return (key->l3index > l3index) ? 1 : -1;
}
if (family == AF_UNSPEC)
return 0;
if (key->family != family)
return (key->family > family) ? 1 : -1;
if (family == AF_INET) {
if (ntohl(key->addr.a4.s_addr) == INADDR_ANY)
return 0;
if (ntohl(addr->a4.s_addr) == INADDR_ANY)
return 0;
return ipv4_prefix_cmp(&key->addr.a4, &addr->a4, prefixlen);
#if IS_ENABLED(CONFIG_IPV6)
} else {
if (ipv6_addr_any(&key->addr.a6) || ipv6_addr_any(&addr->a6))
return 0;
if (ipv6_prefix_equal(&key->addr.a6, &addr->a6, prefixlen))
return 0;
return memcmp(&key->addr.a6, &addr->a6, sizeof(addr->a6));
#endif
}
return -1;
}
static int tcp_ao_key_cmp(const struct tcp_ao_key *key, int l3index,
const union tcp_ao_addr *addr, u8 prefixlen,
int family, int sndid, int rcvid)
{
#if IS_ENABLED(CONFIG_IPV6)
if (family == AF_INET6 && ipv6_addr_v4mapped(&addr->a6)) {
__be32 addr4 = addr->a6.s6_addr32[3];
return __tcp_ao_key_cmp(key, l3index,
(union tcp_ao_addr *)&addr4,
prefixlen, AF_INET, sndid, rcvid);
}
#endif
return __tcp_ao_key_cmp(key, l3index, addr,
prefixlen, family, sndid, rcvid);
}
static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk, int l3index,
const union tcp_ao_addr *addr, int family, u8 prefix,
int sndid, int rcvid)
{
struct tcp_ao_key *key;
struct tcp_ao_info *ao;
if (!static_branch_unlikely(&tcp_ao_needed.key))
return NULL;
ao = rcu_dereference_check(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk));
if (!ao)
return NULL;
hlist_for_each_entry_rcu(key, &ao->head, node) {
u8 prefixlen = min(prefix, key->prefixlen);
if (!tcp_ao_key_cmp(key, l3index, addr, prefixlen,
family, sndid, rcvid))
return key;
}
return NULL;
}
struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, int l3index,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid)
{
return __tcp_ao_do_lookup(sk, l3index, addr, family, U8_MAX, sndid, rcvid);
}
static struct tcp_ao_info *tcp_ao_alloc_info(gfp_t flags)
{
struct tcp_ao_info *ao;
ao = kzalloc(sizeof(*ao), flags);
if (!ao)
return NULL;
INIT_HLIST_HEAD(&ao->head);
refcount_set(&ao->refcnt, 1);
return ao;
}
static void tcp_ao_link_mkt(struct tcp_ao_info *ao, struct tcp_ao_key *mkt)
{
hlist_add_head_rcu(&mkt->node, &ao->head);
}
static struct tcp_ao_key *tcp_ao_copy_key(struct sock *sk,
struct tcp_ao_key *key)
{
struct tcp_ao_key *new_key;
new_key = sock_kmalloc(sk, tcp_ao_sizeof_key(key),
GFP_ATOMIC);
if (!new_key)
return NULL;
*new_key = *key;
INIT_HLIST_NODE(&new_key->node);
tcp_sigpool_get(new_key->tcp_sigpool_id);
atomic64_set(&new_key->pkt_good, 0);
atomic64_set(&new_key->pkt_bad, 0);
return new_key;
}
static void tcp_ao_key_free_rcu(struct rcu_head *head)
{
struct tcp_ao_key *key = container_of(head, struct tcp_ao_key, rcu);
tcp_sigpool_release(key->tcp_sigpool_id);
kfree_sensitive(key);
}
static void tcp_ao_info_free_rcu(struct rcu_head *head)
{
struct tcp_ao_info *ao = container_of(head, struct tcp_ao_info, rcu);
struct tcp_ao_key *key;
struct hlist_node *n;
hlist_for_each_entry_safe(key, n, &ao->head, node) {
hlist_del(&key->node);
tcp_sigpool_release(key->tcp_sigpool_id);
kfree_sensitive(key);
}
kfree(ao);
static_branch_slow_dec_deferred(&tcp_ao_needed);
}
static void tcp_ao_sk_omem_free(struct sock *sk, struct tcp_ao_info *ao)
{
size_t total_ao_sk_mem = 0;
struct tcp_ao_key *key;
hlist_for_each_entry(key, &ao->head, node)
total_ao_sk_mem += tcp_ao_sizeof_key(key);
atomic_sub(total_ao_sk_mem, &sk->sk_omem_alloc);
}
void tcp_ao_destroy_sock(struct sock *sk, bool twsk)
{
struct tcp_ao_info *ao;
if (twsk) {
ao = rcu_dereference_protected(tcp_twsk(sk)->ao_info, 1);
rcu_assign_pointer(tcp_twsk(sk)->ao_info, NULL);
} else {
ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1);
rcu_assign_pointer(tcp_sk(sk)->ao_info, NULL);
}
if (!ao || !refcount_dec_and_test(&ao->refcnt))
return;
if (!twsk)
tcp_ao_sk_omem_free(sk, ao);
call_rcu(&ao->rcu, tcp_ao_info_free_rcu);
}
void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp)
{
struct tcp_ao_info *ao_info = rcu_dereference_protected(tp->ao_info, 1);
if (ao_info) {
struct tcp_ao_key *key;
struct hlist_node *n;
int omem = 0;
hlist_for_each_entry_safe(key, n, &ao_info->head, node) {
omem += tcp_ao_sizeof_key(key);
}
refcount_inc(&ao_info->refcnt);
atomic_sub(omem, &(((struct sock *)tp)->sk_omem_alloc));
rcu_assign_pointer(tcptw->ao_info, ao_info);
} else {
tcptw->ao_info = NULL;
}
}
/* 4 tuple and ISNs are expected in NBO */
static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
__be32 saddr, __be32 daddr,
__be16 sport, __be16 dport,
__be32 sisn, __be32 disn)
{
/* See RFC5926 3.1.1 */
struct kdf_input_block {
u8 counter;
u8 label[6];
struct tcp4_ao_context ctx;
__be16 outlen;
} __packed * tmp;
struct tcp_sigpool hp;
int err;
err = tcp_sigpool_start(mkt->tcp_sigpool_id, &hp);
if (err)
return err;
tmp = hp.scratch;
tmp->counter = 1;
memcpy(tmp->label, "TCP-AO", 6);
tmp->ctx.saddr = saddr;
tmp->ctx.daddr = daddr;
tmp->ctx.sport = sport;
tmp->ctx.dport = dport;
tmp->ctx.sisn = sisn;
tmp->ctx.disn = disn;
tmp->outlen = htons(tcp_ao_digest_size(mkt) * 8); /* in bits */
err = tcp_ao_calc_traffic_key(mkt, key, tmp, sizeof(*tmp), &hp);
tcp_sigpool_end(&hp);
return err;
}
int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk,
__be32 sisn, __be32 disn, bool send)
{
if (send)
return tcp_v4_ao_calc_key(mkt, key, sk->sk_rcv_saddr,
sk->sk_daddr, htons(sk->sk_num),
sk->sk_dport, sisn, disn);
else
return tcp_v4_ao_calc_key(mkt, key, sk->sk_daddr,
sk->sk_rcv_saddr, sk->sk_dport,
htons(sk->sk_num), disn, sisn);
}
static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk,
__be32 sisn, __be32 disn, bool send)
{
if (mkt->family == AF_INET)
return tcp_v4_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
#if IS_ENABLED(CONFIG_IPV6)
else if (mkt->family == AF_INET6)
return tcp_v6_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
#endif
else
return -EOPNOTSUPP;
}
int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
struct request_sock *req)
{
struct inet_request_sock *ireq = inet_rsk(req);
return tcp_v4_ao_calc_key(mkt, key,
ireq->ir_loc_addr, ireq->ir_rmt_addr,
htons(ireq->ir_num), ireq->ir_rmt_port,
htonl(tcp_rsk(req)->snt_isn),
htonl(tcp_rsk(req)->rcv_isn));
}
static int tcp_v4_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
const struct sk_buff *skb,
__be32 sisn, __be32 disn)
{
const struct iphdr *iph = ip_hdr(skb);
const struct tcphdr *th = tcp_hdr(skb);
return tcp_v4_ao_calc_key(mkt, key, iph->saddr, iph->daddr,
th->source, th->dest, sisn, disn);
}
static int tcp_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
const struct sk_buff *skb,
__be32 sisn, __be32 disn, int family)
{
if (family == AF_INET)
return tcp_v4_ao_calc_key_skb(mkt, key, skb, sisn, disn);
#if IS_ENABLED(CONFIG_IPV6)
else if (family == AF_INET6)
return tcp_v6_ao_calc_key_skb(mkt, key, skb, sisn, disn);
#endif
return -EAFNOSUPPORT;
}
static int tcp_v4_ao_hash_pseudoheader(struct tcp_sigpool *hp,
__be32 daddr, __be32 saddr,
int nbytes)
{
struct tcp4_pseudohdr *bp;
struct scatterlist sg;
bp = hp->scratch;
bp->saddr = saddr;
bp->daddr = daddr;
bp->pad = 0;
bp->protocol = IPPROTO_TCP;
bp->len = cpu_to_be16(nbytes);
sg_init_one(&sg, bp, sizeof(*bp));
ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
return crypto_ahash_update(hp->req);
}
static int tcp_ao_hash_pseudoheader(unsigned short int family,
const struct sock *sk,
const struct sk_buff *skb,
struct tcp_sigpool *hp, int nbytes)
{
const struct tcphdr *th = tcp_hdr(skb);
/* TODO: Can we rely on checksum being zero to mean outbound pkt? */
if (!th->check) {
if (family == AF_INET)
return tcp_v4_ao_hash_pseudoheader(hp, sk->sk_daddr,
sk->sk_rcv_saddr, skb->len);
#if IS_ENABLED(CONFIG_IPV6)
else if (family == AF_INET6)
return tcp_v6_ao_hash_pseudoheader(hp, &sk->sk_v6_daddr,
&sk->sk_v6_rcv_saddr, skb->len);
#endif
else
return -EAFNOSUPPORT;
}
if (family == AF_INET) {
const struct iphdr *iph = ip_hdr(skb);
return tcp_v4_ao_hash_pseudoheader(hp, iph->daddr,
iph->saddr, skb->len);
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
const struct ipv6hdr *iph = ipv6_hdr(skb);
return tcp_v6_ao_hash_pseudoheader(hp, &iph->daddr,
&iph->saddr, skb->len);
#endif
}
return -EAFNOSUPPORT;
}
u32 tcp_ao_compute_sne(u32 next_sne, u32 next_seq, u32 seq)
{
u32 sne = next_sne;
if (before(seq, next_seq)) {
if (seq > next_seq)
sne--;
} else {
if (seq < next_seq)
sne++;
}
return sne;
}
/* tcp_ao_hash_sne(struct tcp_sigpool *hp)
* @hp - used for hashing
* @sne - sne value
*/
static int tcp_ao_hash_sne(struct tcp_sigpool *hp, u32 sne)
{
struct scatterlist sg;
__be32 *bp;
bp = (__be32 *)hp->scratch;
*bp = htonl(sne);
sg_init_one(&sg, bp, sizeof(*bp));
ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
return crypto_ahash_update(hp->req);
}
static int tcp_ao_hash_header(struct tcp_sigpool *hp,
const struct tcphdr *th,
bool exclude_options, u8 *hash,
int hash_offset, int hash_len)
{
struct scatterlist sg;
u8 *hdr = hp->scratch;
int err, len;
/* We are not allowed to change tcphdr, make a local copy */
if (exclude_options) {
len = sizeof(*th) + sizeof(struct tcp_ao_hdr) + hash_len;
memcpy(hdr, th, sizeof(*th));
memcpy(hdr + sizeof(*th),
(u8 *)th + hash_offset - sizeof(struct tcp_ao_hdr),
sizeof(struct tcp_ao_hdr));
memset(hdr + sizeof(*th) + sizeof(struct tcp_ao_hdr),
0, hash_len);
((struct tcphdr *)hdr)->check = 0;
} else {
len = th->doff << 2;
memcpy(hdr, th, len);
/* zero out tcp-ao hash */
((struct tcphdr *)hdr)->check = 0;
memset(hdr + hash_offset, 0, hash_len);
}
sg_init_one(&sg, hdr, len);
ahash_request_set_crypt(hp->req, &sg, NULL, len);
err = crypto_ahash_update(hp->req);
WARN_ON_ONCE(err != 0);
return err;
}
int tcp_ao_hash_hdr(unsigned short int family, char *ao_hash,
struct tcp_ao_key *key, const u8 *tkey,
const union tcp_ao_addr *daddr,
const union tcp_ao_addr *saddr,
const struct tcphdr *th, u32 sne)
{
int tkey_len = tcp_ao_digest_size(key);
int hash_offset = ao_hash - (char *)th;
struct tcp_sigpool hp;
void *hash_buf = NULL;
hash_buf = kmalloc(tkey_len, GFP_ATOMIC);
if (!hash_buf)
goto clear_hash_noput;
if (tcp_sigpool_start(key->tcp_sigpool_id, &hp))
goto clear_hash_noput;
if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), tkey, tkey_len))
goto clear_hash;
if (crypto_ahash_init(hp.req))
goto clear_hash;
if (tcp_ao_hash_sne(&hp, sne))
goto clear_hash;
if (family == AF_INET) {
if (tcp_v4_ao_hash_pseudoheader(&hp, daddr->a4.s_addr,
saddr->a4.s_addr, th->doff * 4))
goto clear_hash;
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
if (tcp_v6_ao_hash_pseudoheader(&hp, &daddr->a6,
&saddr->a6, th->doff * 4))
goto clear_hash;
#endif
} else {
WARN_ON_ONCE(1);
goto clear_hash;
}
if (tcp_ao_hash_header(&hp, th,
!!(key->keyflags & TCP_AO_KEYF_EXCLUDE_OPT),
ao_hash, hash_offset, tcp_ao_maclen(key)))
goto clear_hash;
ahash_request_set_crypt(hp.req, NULL, hash_buf, 0);
if (crypto_ahash_final(hp.req))
goto clear_hash;
memcpy(ao_hash, hash_buf, tcp_ao_maclen(key));
tcp_sigpool_end(&hp);
kfree(hash_buf);
return 0;
clear_hash:
tcp_sigpool_end(&hp);
clear_hash_noput:
memset(ao_hash, 0, tcp_ao_maclen(key));
kfree(hash_buf);
return 1;
}
int tcp_ao_hash_skb(unsigned short int family,
char *ao_hash, struct tcp_ao_key *key,
const struct sock *sk, const struct sk_buff *skb,
const u8 *tkey, int hash_offset, u32 sne)
{
const struct tcphdr *th = tcp_hdr(skb);
int tkey_len = tcp_ao_digest_size(key);
struct tcp_sigpool hp;
void *hash_buf = NULL;
hash_buf = kmalloc(tkey_len, GFP_ATOMIC);
if (!hash_buf)
goto clear_hash_noput;
if (tcp_sigpool_start(key->tcp_sigpool_id, &hp))
goto clear_hash_noput;
if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), tkey, tkey_len))
goto clear_hash;
/* For now use sha1 by default. Depends on alg in tcp_ao_key */
if (crypto_ahash_init(hp.req))
goto clear_hash;
if (tcp_ao_hash_sne(&hp, sne))
goto clear_hash;
if (tcp_ao_hash_pseudoheader(family, sk, skb, &hp, skb->len))
goto clear_hash;
if (tcp_ao_hash_header(&hp, th,
!!(key->keyflags & TCP_AO_KEYF_EXCLUDE_OPT),
ao_hash, hash_offset, tcp_ao_maclen(key)))
goto clear_hash;
if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
goto clear_hash;
ahash_request_set_crypt(hp.req, NULL, hash_buf, 0);
if (crypto_ahash_final(hp.req))
goto clear_hash;
memcpy(ao_hash, hash_buf, tcp_ao_maclen(key));
tcp_sigpool_end(&hp);
kfree(hash_buf);
return 0;
clear_hash:
tcp_sigpool_end(&hp);
clear_hash_noput:
memset(ao_hash, 0, tcp_ao_maclen(key));
kfree(hash_buf);
return 1;
}
int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
const struct sock *sk, const struct sk_buff *skb,
const u8 *tkey, int hash_offset, u32 sne)
{
return tcp_ao_hash_skb(AF_INET, ao_hash, key, sk, skb,
tkey, hash_offset, sne);
}
int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key,
struct request_sock *req, const struct sk_buff *skb,
int hash_offset, u32 sne)
{
void *hash_buf = NULL;
int err;
hash_buf = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC);
if (!hash_buf)
return -ENOMEM;
err = tcp_v4_ao_calc_key_rsk(ao_key, hash_buf, req);
if (err)
goto out;
err = tcp_ao_hash_skb(AF_INET, ao_hash, ao_key, req_to_sk(req), skb,
hash_buf, hash_offset, sne);
out:
kfree(hash_buf);
return err;
}
struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid)
{
struct inet_request_sock *ireq = inet_rsk(req);
union tcp_ao_addr *addr = (union tcp_ao_addr *)&ireq->ir_rmt_addr;
int l3index;
l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
return tcp_ao_do_lookup(sk, l3index, addr, AF_INET, sndid, rcvid);
}
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
int l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
addr_sk->sk_bound_dev_if);
union tcp_ao_addr *addr = (union tcp_ao_addr *)&addr_sk->sk_daddr;
return tcp_ao_do_lookup(sk, l3index, addr, AF_INET, sndid, rcvid);
}
int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
const struct tcp_ao_hdr *aoh, int l3index, u32 seq,
struct tcp_ao_key **key, char **traffic_key,
bool *allocated_traffic_key, u8 *keyid, u32 *sne)
{
const struct tcphdr *th = tcp_hdr(skb);
struct tcp_ao_info *ao_info;
*allocated_traffic_key = false;
/* If there's no socket - than initial sisn/disn are unknown.
* Drop the segment. RFC5925 (7.7) advises to require graceful
* restart [RFC4724]. Alternatively, the RFC5925 advises to
* save/restore traffic keys before/after reboot.
* Linux TCP-AO support provides TCP_AO_ADD_KEY and TCP_AO_REPAIR
* options to restore a socket post-reboot.
*/
if (!sk)
return -ENOTCONN;
if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
unsigned int family = READ_ONCE(sk->sk_family);
union tcp_ao_addr *addr;
__be32 disn, sisn;
if (sk->sk_state == TCP_NEW_SYN_RECV) {
struct request_sock *req = inet_reqsk(sk);
sisn = htonl(tcp_rsk(req)->rcv_isn);
disn = htonl(tcp_rsk(req)->snt_isn);
*sne = tcp_ao_compute_sne(0, tcp_rsk(req)->snt_isn, seq);
} else {
sisn = th->seq;
disn = 0;
}
if (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6)
addr = (union tcp_md5_addr *)&ipv6_hdr(skb)->saddr;
else
addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
#if IS_ENABLED(CONFIG_IPV6)
if (family == AF_INET6 && ipv6_addr_v4mapped(&sk->sk_v6_daddr))
family = AF_INET;
#endif
sk = sk_const_to_full_sk(sk);
ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
if (!ao_info)
return -ENOENT;
*key = tcp_ao_do_lookup(sk, l3index, addr, family,
-1, aoh->rnext_keyid);
if (!*key)
return -ENOENT;
*traffic_key = kmalloc(tcp_ao_digest_size(*key), GFP_ATOMIC);
if (!*traffic_key)
return -ENOMEM;
*allocated_traffic_key = true;
if (tcp_ao_calc_key_skb(*key, *traffic_key, skb,
sisn, disn, family))
return -1;
*keyid = (*key)->rcvid;
} else {
struct tcp_ao_key *rnext_key;
u32 snd_basis;
if (sk->sk_state == TCP_TIME_WAIT) {
ao_info = rcu_dereference(tcp_twsk(sk)->ao_info);
snd_basis = tcp_twsk(sk)->tw_snd_nxt;
} else {
ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
snd_basis = tcp_sk(sk)->snd_una;
}
if (!ao_info)
return -ENOENT;
*key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1);
if (!*key)
return -ENOENT;
*traffic_key = snd_other_key(*key);
rnext_key = READ_ONCE(ao_info->rnext_key);
*keyid = rnext_key->rcvid;
*sne = tcp_ao_compute_sne(READ_ONCE(ao_info->snd_sne),
snd_basis, seq);
}
return 0;
}
int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
struct tcp_ao_key *key, struct tcphdr *th,
__u8 *hash_location)
{
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_ao_info *ao;
void *tkey_buf = NULL;
u8 *traffic_key;
u32 sne;
ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk));
traffic_key = snd_other_key(key);
if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
__be32 disn;
if (!(tcb->tcp_flags & TCPHDR_ACK)) {
disn = 0;
tkey_buf = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
if (!tkey_buf)
return -ENOMEM;
traffic_key = tkey_buf;
} else {
disn = ao->risn;
}
tp->af_specific->ao_calc_key_sk(key, traffic_key,
sk, ao->lisn, disn, true);
}
sne = tcp_ao_compute_sne(READ_ONCE(ao->snd_sne), READ_ONCE(tp->snd_una),
ntohl(th->seq));
tp->af_specific->calc_ao_hash(hash_location, key, sk, skb, traffic_key,
hash_location - (u8 *)th, sne);
kfree(tkey_buf);
return 0;
}
static struct tcp_ao_key *tcp_ao_inbound_lookup(unsigned short int family,
const struct sock *sk, const struct sk_buff *skb,
int sndid, int rcvid, int l3index)
{
if (family == AF_INET) {
const struct iphdr *iph = ip_hdr(skb);
return tcp_ao_do_lookup(sk, l3index,
(union tcp_ao_addr *)&iph->saddr,
AF_INET, sndid, rcvid);
} else {
const struct ipv6hdr *iph = ipv6_hdr(skb);
return tcp_ao_do_lookup(sk, l3index,
(union tcp_ao_addr *)&iph->saddr,
AF_INET6, sndid, rcvid);
}
}
void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
struct request_sock *req, unsigned short int family)
{
struct tcp_request_sock *treq = tcp_rsk(req);
const struct tcphdr *th = tcp_hdr(skb);
const struct tcp_ao_hdr *aoh;
struct tcp_ao_key *key;
int l3index;
/* treq->af_specific is used to perform TCP_AO lookup
* in tcp_create_openreq_child().
*/
#if IS_ENABLED(CONFIG_IPV6)
if (family == AF_INET6)
treq->af_specific = &tcp_request_sock_ipv6_ops;
else
#endif
treq->af_specific = &tcp_request_sock_ipv4_ops;
treq->used_tcp_ao = false;
if (tcp_parse_auth_options(th, NULL, &aoh) || !aoh)
return;
l3index = l3mdev_master_ifindex_by_index(sock_net(sk), inet_rsk(req)->ir_iif);
key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid, l3index);
if (!key)
/* Key not found, continue without TCP-AO */
return;
treq->ao_rcv_next = aoh->keyid;
treq->ao_keyid = aoh->rnext_keyid;
treq->used_tcp_ao = true;
}
static enum skb_drop_reason
tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
unsigned short int family, struct tcp_ao_info *info,
const struct tcp_ao_hdr *aoh, struct tcp_ao_key *key,
u8 *traffic_key, u8 *phash, u32 sne, int l3index)
{
const struct tcphdr *th = tcp_hdr(skb);
u8 maclen = tcp_ao_hdr_maclen(aoh);
void *hash_buf = NULL;
if (maclen != tcp_ao_maclen(key)) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
atomic64_inc(&info->counters.pkt_bad);
atomic64_inc(&key->pkt_bad);
trace_tcp_ao_wrong_maclen(sk, skb, aoh->keyid,
aoh->rnext_keyid, maclen);
return SKB_DROP_REASON_TCP_AOFAILURE;
}
hash_buf = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
if (!hash_buf)
return SKB_DROP_REASON_NOT_SPECIFIED;
/* XXX: make it per-AF callback? */
tcp_ao_hash_skb(family, hash_buf, key, sk, skb, traffic_key,
(phash - (u8 *)th), sne);
if (memcmp(phash, hash_buf, maclen)) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
atomic64_inc(&info->counters.pkt_bad);
atomic64_inc(&key->pkt_bad);
trace_tcp_ao_mismatch(sk, skb, aoh->keyid,
aoh->rnext_keyid, maclen);
kfree(hash_buf);
return SKB_DROP_REASON_TCP_AOFAILURE;
}
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOGOOD);
atomic64_inc(&info->counters.pkt_good);
atomic64_inc(&key->pkt_good);
kfree(hash_buf);
return SKB_NOT_DROPPED_YET;
}
enum skb_drop_reason
tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
unsigned short int family, const struct request_sock *req,
int l3index, const struct tcp_ao_hdr *aoh)
{
const struct tcphdr *th = tcp_hdr(skb);
u8 maclen = tcp_ao_hdr_maclen(aoh);
u8 *phash = (u8 *)(aoh + 1); /* hash goes just after the header */
struct tcp_ao_info *info;
enum skb_drop_reason ret;
struct tcp_ao_key *key;
__be32 sisn, disn;
u8 *traffic_key;
int state;
u32 sne = 0;
info = rcu_dereference(tcp_sk(sk)->ao_info);
if (!info) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
trace_tcp_ao_key_not_found(sk, skb, aoh->keyid,
aoh->rnext_keyid, maclen);
return SKB_DROP_REASON_TCP_AOUNEXPECTED;
}
if (unlikely(th->syn)) {
sisn = th->seq;
disn = 0;
}
state = READ_ONCE(sk->sk_state);
/* Fast-path */
if (likely((1 << state) & TCP_AO_ESTABLISHED)) {
enum skb_drop_reason err;
struct tcp_ao_key *current_key;
/* Check if this socket's rnext_key matches the keyid in the
* packet. If not we lookup the key based on the keyid
* matching the rcvid in the mkt.
*/
key = READ_ONCE(info->rnext_key);
if (key->rcvid != aoh->keyid) {
key = tcp_ao_established_key(info, -1, aoh->keyid);
if (!key)
goto key_not_found;
}
/* Delayed retransmitted SYN */
if (unlikely(th->syn && !th->ack))
goto verify_hash;
sne = tcp_ao_compute_sne(info->rcv_sne, tcp_sk(sk)->rcv_nxt,
ntohl(th->seq));
/* Established socket, traffic key are cached */
traffic_key = rcv_other_key(key);
err = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
traffic_key, phash, sne, l3index);
if (err)
return err;
current_key = READ_ONCE(info->current_key);
/* Key rotation: the peer asks us to use new key (RNext) */
if (unlikely(aoh->rnext_keyid != current_key->sndid)) {
trace_tcp_ao_rnext_request(sk, skb, current_key->sndid,
aoh->rnext_keyid,
tcp_ao_hdr_maclen(aoh));
/* If the key is not found we do nothing. */
key = tcp_ao_established_key(info, aoh->rnext_keyid, -1);
if (key)
/* pairs with tcp_ao_del_cmd */
WRITE_ONCE(info->current_key, key);
}
return SKB_NOT_DROPPED_YET;
}
if (unlikely(state == TCP_CLOSE))
return SKB_DROP_REASON_TCP_CLOSE;
/* Lookup key based on peer address and keyid.
* current_key and rnext_key must not be used on tcp listen
* sockets as otherwise:
* - request sockets would race on those key pointers
* - tcp_ao_del_cmd() allows async key removal
*/
key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid, l3index);
if (!key)
goto key_not_found;
if (th->syn && !th->ack)
goto verify_hash;
if ((1 << state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
/* Make the initial syn the likely case here */
if (unlikely(req)) {
sne = tcp_ao_compute_sne(0, tcp_rsk(req)->rcv_isn,
ntohl(th->seq));
sisn = htonl(tcp_rsk(req)->rcv_isn);
disn = htonl(tcp_rsk(req)->snt_isn);
} else if (unlikely(th->ack && !th->syn)) {
/* Possible syncookie packet */
sisn = htonl(ntohl(th->seq) - 1);
disn = htonl(ntohl(th->ack_seq) - 1);
sne = tcp_ao_compute_sne(0, ntohl(sisn),
ntohl(th->seq));
} else if (unlikely(!th->syn)) {
/* no way to figure out initial sisn/disn - drop */
return SKB_DROP_REASON_TCP_FLAGS;
}
} else if ((1 << state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
disn = info->lisn;
if (th->syn || th->rst)
sisn = th->seq;
else
sisn = info->risn;
} else {
WARN_ONCE(1, "TCP-AO: Unexpected sk_state %d", state);
return SKB_DROP_REASON_TCP_AOFAILURE;
}
verify_hash:
traffic_key = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
if (!traffic_key)
return SKB_DROP_REASON_NOT_SPECIFIED;
tcp_ao_calc_key_skb(key, traffic_key, skb, sisn, disn, family);
ret = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
traffic_key, phash, sne, l3index);
kfree(traffic_key);
return ret;
key_not_found:
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
atomic64_inc(&info->counters.key_not_found);
trace_tcp_ao_key_not_found(sk, skb, aoh->keyid,
aoh->rnext_keyid, maclen);
return SKB_DROP_REASON_TCP_AOKEYNOTFOUND;
}
static int tcp_ao_cache_traffic_keys(const struct sock *sk,
struct tcp_ao_info *ao,
struct tcp_ao_key *ao_key)
{
u8 *traffic_key = snd_other_key(ao_key);
int ret;
ret = tcp_ao_calc_key_sk(ao_key, traffic_key, sk,
ao->lisn, ao->risn, true);
if (ret)
return ret;
traffic_key = rcv_other_key(ao_key);
ret = tcp_ao_calc_key_sk(ao_key, traffic_key, sk,
ao->lisn, ao->risn, false);
return ret;
}
void tcp_ao_connect_init(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_ao_info *ao_info;
struct hlist_node *next;
union tcp_ao_addr *addr;
struct tcp_ao_key *key;
int family, l3index;
ao_info = rcu_dereference_protected(tp->ao_info,
lockdep_sock_is_held(sk));
if (!ao_info)
return;
/* Remove all keys that don't match the peer */
family = sk->sk_family;
if (family == AF_INET)
addr = (union tcp_ao_addr *)&sk->sk_daddr;
#if IS_ENABLED(CONFIG_IPV6)
else if (family == AF_INET6)
addr = (union tcp_ao_addr *)&sk->sk_v6_daddr;
#endif
else
return;
l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
sk->sk_bound_dev_if);
hlist_for_each_entry_safe(key, next, &ao_info->head, node) {
if (!tcp_ao_key_cmp(key, l3index, addr, key->prefixlen, family, -1, -1))
continue;
if (key == ao_info->current_key)
ao_info->current_key = NULL;
if (key == ao_info->rnext_key)
ao_info->rnext_key = NULL;
hlist_del_rcu(&key->node);
atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
call_rcu(&key->rcu, tcp_ao_key_free_rcu);
}
key = tp->af_specific->ao_lookup(sk, sk, -1, -1);
if (key) {
/* if current_key or rnext_key were not provided,
* use the first key matching the peer
*/
if (!ao_info->current_key)
ao_info->current_key = key;
if (!ao_info->rnext_key)
ao_info->rnext_key = key;
tp->tcp_header_len += tcp_ao_len_aligned(key);
ao_info->lisn = htonl(tp->write_seq);
ao_info->snd_sne = 0;
} else {
/* Can't happen: tcp_connect() verifies that there's
* at least one tcp-ao key that matches the remote peer.
*/
WARN_ON_ONCE(1);
rcu_assign_pointer(tp->ao_info, NULL);
kfree(ao_info);
}
}
void tcp_ao_established(struct sock *sk)
{
struct tcp_ao_info *ao;
struct tcp_ao_key *key;
ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk));
if (!ao)
return;
hlist_for_each_entry_rcu(key, &ao->head, node)
tcp_ao_cache_traffic_keys(sk, ao, key);
}
void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
{
struct tcp_ao_info *ao;
struct tcp_ao_key *key;
ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk));
if (!ao)
return;
WRITE_ONCE(ao->risn, tcp_hdr(skb)->seq);
ao->rcv_sne = 0;
hlist_for_each_entry_rcu(key, &ao->head, node)
tcp_ao_cache_traffic_keys(sk, ao, key);
}
int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
struct request_sock *req, struct sk_buff *skb,
int family)
{
struct tcp_ao_key *key, *new_key, *first_key;
struct tcp_ao_info *new_ao, *ao;
struct hlist_node *key_head;
int l3index, ret = -ENOMEM;
union tcp_ao_addr *addr;
bool match = false;
ao = rcu_dereference(tcp_sk(sk)->ao_info);
if (!ao)
return 0;
/* New socket without TCP-AO on it */
if (!tcp_rsk_used_ao(req))
return 0;
new_ao = tcp_ao_alloc_info(GFP_ATOMIC);
if (!new_ao)
return -ENOMEM;
new_ao->lisn = htonl(tcp_rsk(req)->snt_isn);
new_ao->risn = htonl(tcp_rsk(req)->rcv_isn);
new_ao->ao_required = ao->ao_required;
new_ao->accept_icmps = ao->accept_icmps;
if (family == AF_INET) {
addr = (union tcp_ao_addr *)&newsk->sk_daddr;
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
addr = (union tcp_ao_addr *)&newsk->sk_v6_daddr;
#endif
} else {
ret = -EAFNOSUPPORT;
goto free_ao;
}
l3index = l3mdev_master_ifindex_by_index(sock_net(newsk),
newsk->sk_bound_dev_if);
hlist_for_each_entry_rcu(key, &ao->head, node) {
if (tcp_ao_key_cmp(key, l3index, addr, key->prefixlen, family, -1, -1))
continue;
new_key = tcp_ao_copy_key(newsk, key);
if (!new_key)
goto free_and_exit;
tcp_ao_cache_traffic_keys(newsk, new_ao, new_key);
tcp_ao_link_mkt(new_ao, new_key);
match = true;
}
if (!match) {
/* RFC5925 (7.4.1) specifies that the TCP-AO status
* of a connection is determined on the initial SYN.
* At this point the connection was TCP-AO enabled, so
* it can't switch to being unsigned if peer's key
* disappears on the listening socket.
*/
ret = -EKEYREJECTED;
goto free_and_exit;
}
if (!static_key_fast_inc_not_disabled(&tcp_ao_needed.key.key)) {
ret = -EUSERS;
goto free_and_exit;
}
key_head = rcu_dereference(hlist_first_rcu(&new_ao->head));
first_key = hlist_entry_safe(key_head, struct tcp_ao_key, node);
key = tcp_ao_established_key(new_ao, tcp_rsk(req)->ao_keyid, -1);
if (key)
new_ao->current_key = key;
else
new_ao->current_key = first_key;
/* set rnext_key */
key = tcp_ao_established_key(new_ao, -1, tcp_rsk(req)->ao_rcv_next);
if (key)
new_ao->rnext_key = key;
else
new_ao->rnext_key = first_key;
sk_gso_disable(newsk);
rcu_assign_pointer(tcp_sk(newsk)->ao_info, new_ao);
return 0;
free_and_exit:
hlist_for_each_entry_safe(key, key_head, &new_ao->head, node) {
hlist_del(&key->node);
tcp_sigpool_release(key->tcp_sigpool_id);
atomic_sub(tcp_ao_sizeof_key(key), &newsk->sk_omem_alloc);
kfree_sensitive(key);
}
free_ao:
kfree(new_ao);
return ret;
}
static bool tcp_ao_can_set_current_rnext(struct sock *sk)
{
/* There aren't current/rnext keys on TCP_LISTEN sockets */
if (sk->sk_state == TCP_LISTEN)
return false;
return true;
}
static int tcp_ao_verify_ipv4(struct sock *sk, struct tcp_ao_add *cmd,
union tcp_ao_addr **addr)
{
struct sockaddr_in *sin = (struct sockaddr_in *)&cmd->addr;
struct inet_sock *inet = inet_sk(sk);
if (sin->sin_family != AF_INET)
return -EINVAL;
/* Currently matching is not performed on port (or port ranges) */
if (sin->sin_port != 0)
return -EINVAL;
/* Check prefix and trailing 0's in addr */
if (cmd->prefix != 0) {
__be32 mask;
if (ntohl(sin->sin_addr.s_addr) == INADDR_ANY)
return -EINVAL;
if (cmd->prefix > 32)
return -EINVAL;
mask = inet_make_mask(cmd->prefix);
if (sin->sin_addr.s_addr & ~mask)
return -EINVAL;
/* Check that MKT address is consistent with socket */
if (ntohl(inet->inet_daddr) != INADDR_ANY &&
(inet->inet_daddr & mask) != sin->sin_addr.s_addr)
return -EINVAL;
} else {
if (ntohl(sin->sin_addr.s_addr) != INADDR_ANY)
return -EINVAL;
}
*addr = (union tcp_ao_addr *)&sin->sin_addr;
return 0;
}
static int tcp_ao_parse_crypto(struct tcp_ao_add *cmd, struct tcp_ao_key *key)
{
unsigned int syn_tcp_option_space;
bool is_kdf_aes_128_cmac = false;
struct crypto_ahash *tfm;
struct tcp_sigpool hp;
void *tmp_key = NULL;
int err;
/* RFC5926, 3.1.1.2. KDF_AES_128_CMAC */
if (!strcmp("cmac(aes128)", cmd->alg_name)) {
strscpy(cmd->alg_name, "cmac(aes)", sizeof(cmd->alg_name));
is_kdf_aes_128_cmac = (cmd->keylen != 16);
tmp_key = kmalloc(cmd->keylen, GFP_KERNEL);
if (!tmp_key)
return -ENOMEM;
}
key->maclen = cmd->maclen ?: 12; /* 12 is the default in RFC5925 */
/* Check: maclen + tcp-ao header <= (MAX_TCP_OPTION_SPACE - mss
* - tstamp (including sackperm)
* - wscale),
* see tcp_syn_options(), tcp_synack_options(), commit 33ad798c924b.
*
* In order to allow D-SACK with TCP-AO, the header size should be:
* (MAX_TCP_OPTION_SPACE - TCPOLEN_TSTAMP_ALIGNED
* - TCPOLEN_SACK_BASE_ALIGNED
* - 2 * TCPOLEN_SACK_PERBLOCK) = 8 (maclen = 4),
* see tcp_established_options().
*
* RFC5925, 2.2:
* Typical MACs are 96-128 bits (12-16 bytes), but any length
* that fits in the header of the segment being authenticated
* is allowed.
*
* RFC5925, 7.6:
* TCP-AO continues to consume 16 bytes in non-SYN segments,
* leaving a total of 24 bytes for other options, of which
* the timestamp consumes 10. This leaves 14 bytes, of which 10
* are used for a single SACK block. When two SACK blocks are used,
* such as to handle D-SACK, a smaller TCP-AO MAC would be required
* to make room for the additional SACK block (i.e., to leave 18
* bytes for the D-SACK variant of the SACK option) [RFC2883].
* Note that D-SACK is not supportable in TCP MD5 in the presence
* of timestamps, because TCP MD5’s MAC length is fixed and too
* large to leave sufficient option space.
*/
syn_tcp_option_space = MAX_TCP_OPTION_SPACE;
syn_tcp_option_space -= TCPOLEN_MSS_ALIGNED;
syn_tcp_option_space -= TCPOLEN_TSTAMP_ALIGNED;
syn_tcp_option_space -= TCPOLEN_WSCALE_ALIGNED;
if (tcp_ao_len_aligned(key) > syn_tcp_option_space) {
err = -EMSGSIZE;
goto err_kfree;
}
key->keylen = cmd->keylen;
memcpy(key->key, cmd->key, cmd->keylen);
err = tcp_sigpool_start(key->tcp_sigpool_id, &hp);
if (err)
goto err_kfree;
tfm = crypto_ahash_reqtfm(hp.req);
if (is_kdf_aes_128_cmac) {
void *scratch = hp.scratch;
struct scatterlist sg;
memcpy(tmp_key, cmd->key, cmd->keylen);
sg_init_one(&sg, tmp_key, cmd->keylen);
/* Using zero-key of 16 bytes as described in RFC5926 */
memset(scratch, 0, 16);
err = crypto_ahash_setkey(tfm, scratch, 16);
if (err)
goto err_pool_end;
err = crypto_ahash_init(hp.req);
if (err)
goto err_pool_end;
ahash_request_set_crypt(hp.req, &sg, key->key, cmd->keylen);
err = crypto_ahash_update(hp.req);
if (err)
goto err_pool_end;
err |= crypto_ahash_final(hp.req);
if (err)
goto err_pool_end;
key->keylen = 16;
}
err = crypto_ahash_setkey(tfm, key->key, key->keylen);
if (err)
goto err_pool_end;
tcp_sigpool_end(&hp);
kfree_sensitive(tmp_key);
if (tcp_ao_maclen(key) > key->digest_size)
return -EINVAL;
return 0;
err_pool_end:
tcp_sigpool_end(&hp);
err_kfree:
kfree_sensitive(tmp_key);
return err;
}
#if IS_ENABLED(CONFIG_IPV6)
static int tcp_ao_verify_ipv6(struct sock *sk, struct tcp_ao_add *cmd,
union tcp_ao_addr **paddr,
unsigned short int *family)
{
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd->addr;
struct in6_addr *addr = &sin6->sin6_addr;
u8 prefix = cmd->prefix;
if (sin6->sin6_family != AF_INET6)
return -EINVAL;
/* Currently matching is not performed on port (or port ranges) */
if (sin6->sin6_port != 0)
return -EINVAL;
/* Check prefix and trailing 0's in addr */
if (cmd->prefix != 0 && ipv6_addr_v4mapped(addr)) {
__be32 addr4 = addr->s6_addr32[3];
__be32 mask;
if (prefix > 32 || ntohl(addr4) == INADDR_ANY)
return -EINVAL;
mask = inet_make_mask(prefix);
if (addr4 & ~mask)
return -EINVAL;
/* Check that MKT address is consistent with socket */
if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
__be32 daddr4 = sk->sk_v6_daddr.s6_addr32[3];
if (!ipv6_addr_v4mapped(&sk->sk_v6_daddr))
return -EINVAL;
if ((daddr4 & mask) != addr4)
return -EINVAL;
}
*paddr = (union tcp_ao_addr *)&addr->s6_addr32[3];
*family = AF_INET;
return 0;
} else if (cmd->prefix != 0) {
struct in6_addr pfx;
if (ipv6_addr_any(addr) || prefix > 128)
return -EINVAL;
ipv6_addr_prefix(&pfx, addr, prefix);
if (ipv6_addr_cmp(&pfx, addr))
return -EINVAL;
/* Check that MKT address is consistent with socket */
if (!ipv6_addr_any(&sk->sk_v6_daddr) &&
!ipv6_prefix_equal(&sk->sk_v6_daddr, addr, prefix))
return -EINVAL;
} else {
if (!ipv6_addr_any(addr))
return -EINVAL;
}
*paddr = (union tcp_ao_addr *)addr;
return 0;
}
#else
static int tcp_ao_verify_ipv6(struct sock *sk, struct tcp_ao_add *cmd,
union tcp_ao_addr **paddr,
unsigned short int *family)
{
return -EOPNOTSUPP;
}
#endif
static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk)
{
if (sk_fullsock(sk)) {
return rcu_dereference_protected(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk));
} else if (sk->sk_state == TCP_TIME_WAIT) {
return rcu_dereference_protected(tcp_twsk(sk)->ao_info,
lockdep_sock_is_held(sk));
}
return ERR_PTR(-ESOCKTNOSUPPORT);
}
static struct tcp_ao_info *getsockopt_ao_info(struct sock *sk)
{
if (sk_fullsock(sk))
return rcu_dereference(tcp_sk(sk)->ao_info);
else if (sk->sk_state == TCP_TIME_WAIT)
return rcu_dereference(tcp_twsk(sk)->ao_info);
return ERR_PTR(-ESOCKTNOSUPPORT);
}
#define TCP_AO_KEYF_ALL (TCP_AO_KEYF_IFINDEX | TCP_AO_KEYF_EXCLUDE_OPT)
#define TCP_AO_GET_KEYF_VALID (TCP_AO_KEYF_IFINDEX)
static struct tcp_ao_key *tcp_ao_key_alloc(struct sock *sk,
struct tcp_ao_add *cmd)
{
const char *algo = cmd->alg_name;
unsigned int digest_size;
struct crypto_ahash *tfm;
struct tcp_ao_key *key;
struct tcp_sigpool hp;
int err, pool_id;
size_t size;
/* Force null-termination of alg_name */
cmd->alg_name[ARRAY_SIZE(cmd->alg_name) - 1] = '\0';
/* RFC5926, 3.1.1.2. KDF_AES_128_CMAC */
if (!strcmp("cmac(aes128)", algo))
algo = "cmac(aes)";
/* Full TCP header (th->doff << 2) should fit into scratch area,
* see tcp_ao_hash_header().
*/
pool_id = tcp_sigpool_alloc_ahash(algo, 60);
if (pool_id < 0)
return ERR_PTR(pool_id);
err = tcp_sigpool_start(pool_id, &hp);
if (err)
goto err_free_pool;
tfm = crypto_ahash_reqtfm(hp.req);
digest_size = crypto_ahash_digestsize(tfm);
tcp_sigpool_end(&hp);
size = sizeof(struct tcp_ao_key) + (digest_size << 1);
key = sock_kmalloc(sk, size, GFP_KERNEL);
if (!key) {
err = -ENOMEM;
goto err_free_pool;
}
key->tcp_sigpool_id = pool_id;
key->digest_size = digest_size;
return key;
err_free_pool:
tcp_sigpool_release(pool_id);
return ERR_PTR(err);
}
static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
sockptr_t optval, int optlen)
{
struct tcp_ao_info *ao_info;
union tcp_ao_addr *addr;
struct tcp_ao_key *key;
struct tcp_ao_add cmd;
int ret, l3index = 0;
bool first = false;
if (optlen < sizeof(cmd))
return -EINVAL;
ret = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
if (ret)
return ret;
if (cmd.keylen > TCP_AO_MAXKEYLEN)
return -EINVAL;
if (cmd.reserved != 0 || cmd.reserved2 != 0)
return -EINVAL;
if (family == AF_INET)
ret = tcp_ao_verify_ipv4(sk, &cmd, &addr);
else
ret = tcp_ao_verify_ipv6(sk, &cmd, &addr, &family);
if (ret)
return ret;
if (cmd.keyflags & ~TCP_AO_KEYF_ALL)
return -EINVAL;
if (cmd.set_current || cmd.set_rnext) {
if (!tcp_ao_can_set_current_rnext(sk))
return -EINVAL;
}
if (cmd.ifindex && !(cmd.keyflags & TCP_AO_KEYF_IFINDEX))
return -EINVAL;
/* For cmd.tcp_ifindex = 0 the key will apply to the default VRF */
if (cmd.keyflags & TCP_AO_KEYF_IFINDEX && cmd.ifindex) {
int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
struct net_device *dev;
rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(sk), cmd.ifindex);
if (dev && netif_is_l3_master(dev))
l3index = dev->ifindex;
rcu_read_unlock();
if (!dev || !l3index)
return -EINVAL;
if (!bound_dev_if || bound_dev_if != cmd.ifindex) {
/* tcp_ao_established_key() doesn't expect having
* non peer-matching key on an established TCP-AO
* connection.
*/
if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)))
return -EINVAL;
}
/* It's still possible to bind after adding keys or even
* re-bind to a different dev (with CAP_NET_RAW).
* So, no reason to return error here, rather try to be
* nice and warn the user.
*/
if (bound_dev_if && bound_dev_if != cmd.ifindex)
net_warn_ratelimited("AO key ifindex %d != sk bound ifindex %d\n",
cmd.ifindex, bound_dev_if);
}
/* Don't allow keys for peers that have a matching TCP-MD5 key */
if (cmd.keyflags & TCP_AO_KEYF_IFINDEX) {
/* Non-_exact version of tcp_md5_do_lookup() will
* as well match keys that aren't bound to a specific VRF
* (that will make them match AO key with
* sysctl_tcp_l3dev_accept = 1
*/
if (tcp_md5_do_lookup(sk, l3index, addr, family))
return -EKEYREJECTED;
} else {
if (tcp_md5_do_lookup_any_l3index(sk, addr, family))
return -EKEYREJECTED;
}
ao_info = setsockopt_ao_info(sk);
if (IS_ERR(ao_info))
return PTR_ERR(ao_info);
if (!ao_info) {
ao_info = tcp_ao_alloc_info(GFP_KERNEL);
if (!ao_info)
return -ENOMEM;
first = true;
} else {
/* Check that neither RecvID nor SendID match any
* existing key for the peer, RFC5925 3.1:
* > The IDs of MKTs MUST NOT overlap where their
* > TCP connection identifiers overlap.
*/
if (__tcp_ao_do_lookup(sk, l3index, addr, family, cmd.prefix, -1, cmd.rcvid))
return -EEXIST;
if (__tcp_ao_do_lookup(sk, l3index, addr, family,
cmd.prefix, cmd.sndid, -1))
return -EEXIST;
}
key = tcp_ao_key_alloc(sk, &cmd);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto err_free_ao;
}
INIT_HLIST_NODE(&key->node);
memcpy(&key->addr, addr, (family == AF_INET) ? sizeof(struct in_addr) :
sizeof(struct in6_addr));
key->prefixlen = cmd.prefix;
key->family = family;
key->keyflags = cmd.keyflags;
key->sndid = cmd.sndid;
key->rcvid = cmd.rcvid;
key->l3index = l3index;
atomic64_set(&key->pkt_good, 0);
atomic64_set(&key->pkt_bad, 0);
ret = tcp_ao_parse_crypto(&cmd, key);
if (ret < 0)
goto err_free_sock;
if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))) {
tcp_ao_cache_traffic_keys(sk, ao_info, key);
if (first) {
ao_info->current_key = key;
ao_info->rnext_key = key;
}
}
tcp_ao_link_mkt(ao_info, key);
if (first) {
if (!static_branch_inc(&tcp_ao_needed.key)) {
ret = -EUSERS;
goto err_free_sock;
}
sk_gso_disable(sk);
rcu_assign_pointer(tcp_sk(sk)->ao_info, ao_info);
}
if (cmd.set_current)
WRITE_ONCE(ao_info->current_key, key);
if (cmd.set_rnext)
WRITE_ONCE(ao_info->rnext_key, key);
return 0;
err_free_sock:
atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
tcp_sigpool_release(key->tcp_sigpool_id);
kfree_sensitive(key);
err_free_ao:
if (first)
kfree(ao_info);
return ret;
}
static int tcp_ao_delete_key(struct sock *sk, struct tcp_ao_info *ao_info,
bool del_async, struct tcp_ao_key *key,
struct tcp_ao_key *new_current,
struct tcp_ao_key *new_rnext)
{
int err;
hlist_del_rcu(&key->node);
/* Support for async delete on listening sockets: as they don't
* need current_key/rnext_key maintaining, we don't need to check
* them and we can just free all resources in RCU fashion.
*/
if (del_async) {
atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
call_rcu(&key->rcu, tcp_ao_key_free_rcu);
return 0;
}
/* At this moment another CPU could have looked this key up
* while it was unlinked from the list. Wait for RCU grace period,
* after which the key is off-list and can't be looked up again;
* the rx path [just before RCU came] might have used it and set it
* as current_key (very unlikely).
* Free the key with next RCU grace period (in case it was
* current_key before tcp_ao_current_rnext() might have
* changed it in forced-delete).
*/
synchronize_rcu();
if (new_current)
WRITE_ONCE(ao_info->current_key, new_current);
if (new_rnext)
WRITE_ONCE(ao_info->rnext_key, new_rnext);
if (unlikely(READ_ONCE(ao_info->current_key) == key ||
READ_ONCE(ao_info->rnext_key) == key)) {
err = -EBUSY;
goto add_key;
}
atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
call_rcu(&key->rcu, tcp_ao_key_free_rcu);
return 0;
add_key:
hlist_add_head_rcu(&key->node, &ao_info->head);
return err;
}
#define TCP_AO_DEL_KEYF_ALL (TCP_AO_KEYF_IFINDEX)
static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
sockptr_t optval, int optlen)
{
struct tcp_ao_key *key, *new_current = NULL, *new_rnext = NULL;
int err, addr_len, l3index = 0;
struct tcp_ao_info *ao_info;
union tcp_ao_addr *addr;
struct tcp_ao_del cmd;
__u8 prefix;
u16 port;
if (optlen < sizeof(cmd))
return -EINVAL;
err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
if (err)
return err;
if (cmd.reserved != 0 || cmd.reserved2 != 0)
return -EINVAL;
if (cmd.set_current || cmd.set_rnext) {
if (!tcp_ao_can_set_current_rnext(sk))
return -EINVAL;
}
if (cmd.keyflags & ~TCP_AO_DEL_KEYF_ALL)
return -EINVAL;
/* No sanity check for TCP_AO_KEYF_IFINDEX as if a VRF
* was destroyed, there still should be a way to delete keys,
* that were bound to that l3intf. So, fail late at lookup stage
* if there is no key for that ifindex.
*/
if (cmd.ifindex && !(cmd.keyflags & TCP_AO_KEYF_IFINDEX))
return -EINVAL;
ao_info = setsockopt_ao_info(sk);
if (IS_ERR(ao_info))
return PTR_ERR(ao_info);
if (!ao_info)
return -ENOENT;
/* For sockets in TCP_CLOSED it's possible set keys that aren't
* matching the future peer (address/VRF/etc),
* tcp_ao_connect_init() will choose a correct matching MKT
* if there's any.
*/
if (cmd.set_current) {
new_current = tcp_ao_established_key(ao_info, cmd.current_key, -1);
if (!new_current)
return -ENOENT;
}
if (cmd.set_rnext) {
new_rnext = tcp_ao_established_key(ao_info, -1, cmd.rnext);
if (!new_rnext)
return -ENOENT;
}
if (cmd.del_async && sk->sk_state != TCP_LISTEN)
return -EINVAL;
if (family == AF_INET) {
struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.addr;
addr = (union tcp_ao_addr *)&sin->sin_addr;
addr_len = sizeof(struct in_addr);
port = ntohs(sin->sin_port);
} else {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.addr;
struct in6_addr *addr6 = &sin6->sin6_addr;
if (ipv6_addr_v4mapped(addr6)) {
addr = (union tcp_ao_addr *)&addr6->s6_addr32[3];
addr_len = sizeof(struct in_addr);
family = AF_INET;
} else {
addr = (union tcp_ao_addr *)addr6;
addr_len = sizeof(struct in6_addr);
}
port = ntohs(sin6->sin6_port);
}
prefix = cmd.prefix;
/* Currently matching is not performed on port (or port ranges) */
if (port != 0)
return -EINVAL;
/* We could choose random present key here for current/rnext
* but that's less predictable. Let's be strict and don't
* allow removing a key that's in use. RFC5925 doesn't
* specify how-to coordinate key removal, but says:
* "It is presumed that an MKT affecting a particular
* connection cannot be destroyed during an active connection"
*/
hlist_for_each_entry_rcu(key, &ao_info->head, node) {
if (cmd.sndid != key->sndid ||
cmd.rcvid != key->rcvid)
continue;
if (family != key->family ||
prefix != key->prefixlen ||
memcmp(addr, &key->addr, addr_len))
continue;
if ((cmd.keyflags & TCP_AO_KEYF_IFINDEX) !=
(key->keyflags & TCP_AO_KEYF_IFINDEX))
continue;
if (key->l3index != l3index)
continue;
if (key == new_current || key == new_rnext)
continue;
return tcp_ao_delete_key(sk, ao_info, cmd.del_async, key,
new_current, new_rnext);
}
return -ENOENT;
}
/* cmd.ao_required makes a socket TCP-AO only.
* Don't allow any md5 keys for any l3intf on the socket together with it.
* Restricting it early in setsockopt() removes a check for
* ao_info->ao_required on inbound tcp segment fast-path.
*/
static int tcp_ao_required_verify(struct sock *sk)
{
#ifdef CONFIG_TCP_MD5SIG
const struct tcp_md5sig_info *md5sig;
if (!static_branch_unlikely(&tcp_md5_needed.key))
return 0;
md5sig = rcu_dereference_check(tcp_sk(sk)->md5sig_info,
lockdep_sock_is_held(sk));
if (!md5sig)
return 0;
if (rcu_dereference_check(hlist_first_rcu(&md5sig->head),
lockdep_sock_is_held(sk)))
return 1;
#endif
return 0;
}
static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
sockptr_t optval, int optlen)
{
struct tcp_ao_key *new_current = NULL, *new_rnext = NULL;
struct tcp_ao_info *ao_info;
struct tcp_ao_info_opt cmd;
bool first = false;
int err;
if (optlen < sizeof(cmd))
return -EINVAL;
err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
if (err)
return err;
if (cmd.set_current || cmd.set_rnext) {
if (!tcp_ao_can_set_current_rnext(sk))
return -EINVAL;
}
if (cmd.reserved != 0 || cmd.reserved2 != 0)
return -EINVAL;
ao_info = setsockopt_ao_info(sk);
if (IS_ERR(ao_info))
return PTR_ERR(ao_info);
if (!ao_info) {
if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)))
return -EINVAL;
ao_info = tcp_ao_alloc_info(GFP_KERNEL);
if (!ao_info)
return -ENOMEM;
first = true;
}
if (cmd.ao_required && tcp_ao_required_verify(sk)) {
err = -EKEYREJECTED;
goto out;
}
/* For sockets in TCP_CLOSED it's possible set keys that aren't
* matching the future peer (address/port/VRF/etc),
* tcp_ao_connect_init() will choose a correct matching MKT
* if there's any.
*/
if (cmd.set_current) {
new_current = tcp_ao_established_key(ao_info, cmd.current_key, -1);
if (!new_current) {
err = -ENOENT;
goto out;
}
}
if (cmd.set_rnext) {
new_rnext = tcp_ao_established_key(ao_info, -1, cmd.rnext);
if (!new_rnext) {
err = -ENOENT;
goto out;
}
}
if (cmd.set_counters) {
atomic64_set(&ao_info->counters.pkt_good, cmd.pkt_good);
atomic64_set(&ao_info->counters.pkt_bad, cmd.pkt_bad);
atomic64_set(&ao_info->counters.key_not_found, cmd.pkt_key_not_found);
atomic64_set(&ao_info->counters.ao_required, cmd.pkt_ao_required);
atomic64_set(&ao_info->counters.dropped_icmp, cmd.pkt_dropped_icmp);
}
ao_info->ao_required = cmd.ao_required;
ao_info->accept_icmps = cmd.accept_icmps;
if (new_current)
WRITE_ONCE(ao_info->current_key, new_current);
if (new_rnext)
WRITE_ONCE(ao_info->rnext_key, new_rnext);
if (first) {
if (!static_branch_inc(&tcp_ao_needed.key)) {
err = -EUSERS;
goto out;
}
sk_gso_disable(sk);
rcu_assign_pointer(tcp_sk(sk)->ao_info, ao_info);
}
return 0;
out:
if (first)
kfree(ao_info);
return err;
}
int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen)
{
if (WARN_ON_ONCE(family != AF_INET && family != AF_INET6))
return -EAFNOSUPPORT;
switch (cmd) {
case TCP_AO_ADD_KEY:
return tcp_ao_add_cmd(sk, family, optval, optlen);
case TCP_AO_DEL_KEY:
return tcp_ao_del_cmd(sk, family, optval, optlen);
case TCP_AO_INFO:
return tcp_ao_info_cmd(sk, family, optval, optlen);
default:
WARN_ON_ONCE(1);
return -EINVAL;
}
}
int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen)
{
return tcp_parse_ao(sk, cmd, AF_INET, optval, optlen);
}
/* tcp_ao_copy_mkts_to_user(ao_info, optval, optlen)
*
* @ao_info: struct tcp_ao_info on the socket that
* socket getsockopt(TCP_AO_GET_KEYS) is executed on
* @optval: pointer to array of tcp_ao_getsockopt structures in user space.
* Must be != NULL.
* @optlen: pointer to size of tcp_ao_getsockopt structure.
* Must be != NULL.
*
* Return value: 0 on success, a negative error number otherwise.
*
* optval points to an array of tcp_ao_getsockopt structures in user space.
* optval[0] is used as both input and output to getsockopt. It determines
* which keys are returned by the kernel.
* optval[0].nkeys is the size of the array in user space. On return it contains
* the number of keys matching the search criteria.
* If tcp_ao_getsockopt::get_all is set, then all keys in the socket are
* returned, otherwise only keys matching <addr, prefix, sndid, rcvid>
* in optval[0] are returned.
* optlen is also used as both input and output. The user provides the size
* of struct tcp_ao_getsockopt in user space, and the kernel returns the size
* of the structure in kernel space.
* The size of struct tcp_ao_getsockopt may differ between user and kernel.
* There are three cases to consider:
* * If usize == ksize, then keys are copied verbatim.
* * If usize < ksize, then the userspace has passed an old struct to a
* newer kernel. The rest of the trailing bytes in optval[0]
* (ksize - usize) are interpreted as 0 by the kernel.
* * If usize > ksize, then the userspace has passed a new struct to an
* older kernel. The trailing bytes unknown to the kernel (usize - ksize)
* are checked to ensure they are zeroed, otherwise -E2BIG is returned.
* On return the kernel fills in min(usize, ksize) in each entry of the array.
* The layout of the fields in the user and kernel structures is expected to
* be the same (including in the 32bit vs 64bit case).
*/
static int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
sockptr_t optval, sockptr_t optlen)
{
struct tcp_ao_getsockopt opt_in, opt_out;
struct tcp_ao_key *key, *current_key;
bool do_address_matching = true;
union tcp_ao_addr *addr = NULL;
int err, l3index, user_len;
unsigned int max_keys; /* maximum number of keys to copy to user */
size_t out_offset = 0;
size_t bytes_to_write; /* number of bytes to write to user level */
u32 matched_keys; /* keys from ao_info matched so far */
int optlen_out;
__be16 port = 0;
if (copy_from_sockptr(&user_len, optlen, sizeof(int)))
return -EFAULT;
if (user_len <= 0)
return -EINVAL;
memset(&opt_in, 0, sizeof(struct tcp_ao_getsockopt));
err = copy_struct_from_sockptr(&opt_in, sizeof(opt_in),
optval, user_len);
if (err < 0)
return err;
if (opt_in.pkt_good || opt_in.pkt_bad)
return -EINVAL;
if (opt_in.keyflags & ~TCP_AO_GET_KEYF_VALID)
return -EINVAL;
if (opt_in.ifindex && !(opt_in.keyflags & TCP_AO_KEYF_IFINDEX))
return -EINVAL;
if (opt_in.reserved != 0)
return -EINVAL;
max_keys = opt_in.nkeys;
l3index = (opt_in.keyflags & TCP_AO_KEYF_IFINDEX) ? opt_in.ifindex : -1;
if (opt_in.get_all || opt_in.is_current || opt_in.is_rnext) {
if (opt_in.get_all && (opt_in.is_current || opt_in.is_rnext))
return -EINVAL;
do_address_matching = false;
}
switch (opt_in.addr.ss_family) {
case AF_INET: {
struct sockaddr_in *sin;
__be32 mask;
sin = (struct sockaddr_in *)&opt_in.addr;
port = sin->sin_port;
addr = (union tcp_ao_addr *)&sin->sin_addr;
if (opt_in.prefix > 32)
return -EINVAL;
if (ntohl(sin->sin_addr.s_addr) == INADDR_ANY &&
opt_in.prefix != 0)
return -EINVAL;
mask = inet_make_mask(opt_in.prefix);
if (sin->sin_addr.s_addr & ~mask)
return -EINVAL;
break;
}
case AF_INET6: {
struct sockaddr_in6 *sin6;
struct in6_addr *addr6;
sin6 = (struct sockaddr_in6 *)&opt_in.addr;
addr = (union tcp_ao_addr *)&sin6->sin6_addr;
addr6 = &sin6->sin6_addr;
port = sin6->sin6_port;
/* We don't have to change family and @addr here if
* ipv6_addr_v4mapped() like in key adding:
* tcp_ao_key_cmp() does it. Do the sanity checks though.
*/
if (opt_in.prefix != 0) {
if (ipv6_addr_v4mapped(addr6)) {
__be32 mask, addr4 = addr6->s6_addr32[3];
if (opt_in.prefix > 32 ||
ntohl(addr4) == INADDR_ANY)
return -EINVAL;
mask = inet_make_mask(opt_in.prefix);
if (addr4 & ~mask)
return -EINVAL;
} else {
struct in6_addr pfx;
if (ipv6_addr_any(addr6) ||
opt_in.prefix > 128)
return -EINVAL;
ipv6_addr_prefix(&pfx, addr6, opt_in.prefix);
if (ipv6_addr_cmp(&pfx, addr6))
return -EINVAL;
}
} else if (!ipv6_addr_any(addr6)) {
return -EINVAL;
}
break;
}
case 0:
if (!do_address_matching)
break;
fallthrough;
default:
return -EAFNOSUPPORT;
}
if (!do_address_matching) {
/* We could just ignore those, but let's do stricter checks */
if (addr || port)
return -EINVAL;
if (opt_in.prefix || opt_in.sndid || opt_in.rcvid)
return -EINVAL;
}
bytes_to_write = min_t(int, user_len, sizeof(struct tcp_ao_getsockopt));
matched_keys = 0;
/* May change in RX, while we're dumping, pre-fetch it */
current_key = READ_ONCE(ao_info->current_key);
hlist_for_each_entry_rcu(key, &ao_info->head, node) {
if (opt_in.get_all)
goto match;
if (opt_in.is_current || opt_in.is_rnext) {
if (opt_in.is_current && key == current_key)
goto match;
if (opt_in.is_rnext && key == ao_info->rnext_key)
goto match;
continue;
}
if (tcp_ao_key_cmp(key, l3index, addr, opt_in.prefix,
opt_in.addr.ss_family,
opt_in.sndid, opt_in.rcvid) != 0)
continue;
match:
matched_keys++;
if (matched_keys > max_keys)
continue;
memset(&opt_out, 0, sizeof(struct tcp_ao_getsockopt));
if (key->family == AF_INET) {
struct sockaddr_in *sin_out = (struct sockaddr_in *)&opt_out.addr;
sin_out->sin_family = key->family;
sin_out->sin_port = 0;
memcpy(&sin_out->sin_addr, &key->addr, sizeof(struct in_addr));
} else {
struct sockaddr_in6 *sin6_out = (struct sockaddr_in6 *)&opt_out.addr;
sin6_out->sin6_family = key->family;
sin6_out->sin6_port = 0;
memcpy(&sin6_out->sin6_addr, &key->addr, sizeof(struct in6_addr));
}
opt_out.sndid = key->sndid;
opt_out.rcvid = key->rcvid;
opt_out.prefix = key->prefixlen;
opt_out.keyflags = key->keyflags;
opt_out.is_current = (key == current_key);
opt_out.is_rnext = (key == ao_info->rnext_key);
opt_out.nkeys = 0;
opt_out.maclen = key->maclen;
opt_out.keylen = key->keylen;
opt_out.ifindex = key->l3index;
opt_out.pkt_good = atomic64_read(&key->pkt_good);
opt_out.pkt_bad = atomic64_read(&key->pkt_bad);
memcpy(&opt_out.key, key->key, key->keylen);
tcp_sigpool_algo(key->tcp_sigpool_id, opt_out.alg_name, 64);
/* Copy key to user */
if (copy_to_sockptr_offset(optval, out_offset,
&opt_out, bytes_to_write))
return -EFAULT;
out_offset += user_len;
}
optlen_out = (int)sizeof(struct tcp_ao_getsockopt);
if (copy_to_sockptr(optlen, &optlen_out, sizeof(int)))
return -EFAULT;
out_offset = offsetof(struct tcp_ao_getsockopt, nkeys);
if (copy_to_sockptr_offset(optval, out_offset,
&matched_keys, sizeof(u32)))
return -EFAULT;
return 0;
}
int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen)
{
struct tcp_ao_info *ao_info;
ao_info = setsockopt_ao_info(sk);
if (IS_ERR(ao_info))
return PTR_ERR(ao_info);
if (!ao_info)
return -ENOENT;
return tcp_ao_copy_mkts_to_user(ao_info, optval, optlen);
}
int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen)
{
struct tcp_ao_info_opt out, in = {};
struct tcp_ao_key *current_key;
struct tcp_ao_info *ao;
int err, len;
if (copy_from_sockptr(&len, optlen, sizeof(int)))
return -EFAULT;
if (len <= 0)
return -EINVAL;
/* Copying this "in" only to check ::reserved, ::reserved2,
* that may be needed to extend (struct tcp_ao_info_opt) and
* what getsockopt() provides in future.
*/
err = copy_struct_from_sockptr(&in, sizeof(in), optval, len);
if (err)
return err;
if (in.reserved != 0 || in.reserved2 != 0)
return -EINVAL;
ao = setsockopt_ao_info(sk);
if (IS_ERR(ao))
return PTR_ERR(ao);
if (!ao)
return -ENOENT;
memset(&out, 0, sizeof(out));
out.ao_required = ao->ao_required;
out.accept_icmps = ao->accept_icmps;
out.pkt_good = atomic64_read(&ao->counters.pkt_good);
out.pkt_bad = atomic64_read(&ao->counters.pkt_bad);
out.pkt_key_not_found = atomic64_read(&ao->counters.key_not_found);
out.pkt_ao_required = atomic64_read(&ao->counters.ao_required);
out.pkt_dropped_icmp = atomic64_read(&ao->counters.dropped_icmp);
current_key = READ_ONCE(ao->current_key);
if (current_key) {
out.set_current = 1;
out.current_key = current_key->sndid;
}
if (ao->rnext_key) {
out.set_rnext = 1;
out.rnext = ao->rnext_key->rcvid;
}
if (copy_to_sockptr(optval, &out, min_t(int, len, sizeof(out))))
return -EFAULT;
return 0;
}
int tcp_ao_set_repair(struct sock *sk, sockptr_t optval, unsigned int optlen)
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_ao_repair cmd;
struct tcp_ao_key *key;
struct tcp_ao_info *ao;
int err;
if (optlen < sizeof(cmd))
return -EINVAL;
err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
if (err)
return err;
if (!tp->repair)
return -EPERM;
ao = setsockopt_ao_info(sk);
if (IS_ERR(ao))
return PTR_ERR(ao);
if (!ao)
return -ENOENT;
WRITE_ONCE(ao->lisn, cmd.snt_isn);
WRITE_ONCE(ao->risn, cmd.rcv_isn);
WRITE_ONCE(ao->snd_sne, cmd.snd_sne);
WRITE_ONCE(ao->rcv_sne, cmd.rcv_sne);
hlist_for_each_entry_rcu(key, &ao->head, node)
tcp_ao_cache_traffic_keys(sk, ao, key);
return 0;
}
int tcp_ao_get_repair(struct sock *sk, sockptr_t optval, sockptr_t optlen)
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_ao_repair opt;
struct tcp_ao_info *ao;
int len;
if (copy_from_sockptr(&len, optlen, sizeof(int)))
return -EFAULT;
if (len <= 0)
return -EINVAL;
if (!tp->repair)
return -EPERM;
rcu_read_lock();
ao = getsockopt_ao_info(sk);
if (IS_ERR_OR_NULL(ao)) {
rcu_read_unlock();
return ao ? PTR_ERR(ao) : -ENOENT;
}
opt.snt_isn = ao->lisn;
opt.rcv_isn = ao->risn;
opt.snd_sne = READ_ONCE(ao->snd_sne);
opt.rcv_sne = READ_ONCE(ao->rcv_sne);
rcu_read_unlock();
if (copy_to_sockptr(optval, &opt, min_t(int, len, sizeof(opt))))
return -EFAULT;
return 0;
}