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net/tcp: Wire TCP-AO to request sockets

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Now when the new request socket is created from the listening socket,
it's recorded what MKT was used by the peer. tcp_rsk_used_ao() is
a new helper for checking if TCP-AO option was used to create the
request socket.
tcp_ao_copy_all_matching() will copy all keys that match the peer on the
request socket, as well as preparing them for the usage (creating
traffic keys).

Co-developed-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Co-developed-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Salam Noureddine <noureddine@arista.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dmitry Safonov 2023-10-23 20:22:02 +01:00 committed by David S. Miller
parent decde2586b
commit 06b22ef295
12 changed files with 505 additions and 50 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

18
include/linux/tcp.h
View file

@ -166,6 +166,11 @@ struct tcp_request_sock {
* after data-in-SYN.
*/
u8 syn_tos;
#ifdef CONFIG_TCP_AO
u8 ao_keyid;
u8 ao_rcv_next;
u8 maclen;
#endif
};
static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
@ -173,6 +178,19 @@ static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
return (struct tcp_request_sock *)req;
}
static inline bool tcp_rsk_used_ao(const struct request_sock *req)
{
/* The real length of MAC is saved in the request socket,
* signing anything with zero-length makes no sense, so here is
* a little hack..
*/
#ifndef CONFIG_TCP_AO
return false;
#else
return tcp_rsk(req)->maclen != 0;
#endif
}
#define TCP_RMEM_TO_WIN_SCALE 8
struct tcp_sock {

6
include/net/tcp.h
View file

@ -2216,6 +2216,12 @@ struct tcp_request_sock_ops {
const struct sock *sk,
const struct sk_buff *skb);
#endif
#ifdef CONFIG_TCP_AO
struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid);
int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk);
#endif
#ifdef CONFIG_SYN_COOKIES
__u32 (*cookie_init_seq)(const struct sk_buff *skb,
__u16 *mss);

24
include/net/tcp_ao.h
View file

@ -123,6 +123,9 @@ int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
int sndid, int rcvid);
int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
struct request_sock *req, struct sk_buff *skb,
int family);
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp);
void tcp_ao_destroy_sock(struct sock *sk, bool twsk);
@ -147,6 +150,11 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk,
__be32 sisn, __be32 disn, bool send);
int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
struct request_sock *req);
struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid);
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);
@ -154,11 +162,21 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
const struct in6_addr *daddr,
const struct in6_addr *saddr, int nbytes);
int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
const struct sk_buff *skb, __be32 sisn, __be32 disn);
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send);
int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
struct request_sock *req);
struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
const struct in6_addr *addr,
int sndid, int rcvid);
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk, int sndid, int rcvid);
struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid);
int tcp_v6_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);
@ -178,6 +196,12 @@ static inline int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
return 0;
}
static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
struct tcp_request_sock *treq,
unsigned short int family)
{
}
static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr, int family, int sndid, int rcvid)
{

2
net/ipv4/syncookies.c
View file

@ -400,6 +400,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
treq->snt_synack = 0;
treq->tfo_listener = false;
tcp_ao_syncookie(sk, skb, treq, AF_INET);
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;

264
net/ipv4/tcp_ao.c
View file

@ -169,6 +169,23 @@ 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);
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);
@ -290,6 +307,42 @@ static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
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)
@ -515,6 +568,16 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
tkey, hash_offset, sne);
}
struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid)
{
union tcp_ao_addr *addr =
(union tcp_ao_addr *)&inet_rsk(req)->ir_rmt_addr;
return tcp_ao_do_lookup(sk, 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)
{
@ -528,7 +591,7 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
struct tcp_ao_key **key, char **traffic_key,
bool *allocated_traffic_key, u8 *keyid, u32 *sne)
{
struct tcp_ao_key *rnext_key;
const struct tcphdr *th = tcp_hdr(skb);
struct tcp_ao_info *ao_info;
*allocated_traffic_key = false;
@ -543,23 +606,62 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
return -ENOTCONN;
if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
return -1;
unsigned int family = READ_ONCE(sk->sk_family);
union tcp_ao_addr *addr;
__be32 disn, sisn;
if (sk->sk_state == TCP_TIME_WAIT)
ao_info = rcu_dereference(tcp_twsk(sk)->ao_info);
else
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 = 0;
} 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;
if (!ao_info)
return -ENOENT;
*key = tcp_ao_do_lookup(sk, 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;
*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 = 0;
if (sk->sk_state == TCP_TIME_WAIT)
ao_info = rcu_dereference(tcp_twsk(sk)->ao_info);
else
ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
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 = 0;
}
return 0;
}
@ -597,6 +699,46 @@ int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
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)
{
if (family == AF_INET) {
const struct iphdr *iph = ip_hdr(skb);
return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)&iph->saddr,
AF_INET, sndid, rcvid);
} else {
const struct ipv6hdr *iph = ipv6_hdr(skb);
return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)&iph->saddr,
AF_INET6, sndid, rcvid);
}
}
void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
struct tcp_request_sock *treq,
unsigned short int family)
{
const struct tcphdr *th = tcp_hdr(skb);
const struct tcp_ao_hdr *aoh;
struct tcp_ao_key *key;
treq->maclen = 0;
if (tcp_parse_auth_options(th, NULL, &aoh) || !aoh)
return;
key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid);
if (!key)
/* Key not found, continue without TCP-AO */
return;
treq->ao_rcv_next = aoh->keyid;
treq->ao_keyid = aoh->rnext_keyid;
treq->maclen = tcp_ao_maclen(key);
}
static int tcp_ao_cache_traffic_keys(const struct sock *sk,
struct tcp_ao_info *ao,
struct tcp_ao_key *ao_key)
@ -704,6 +846,100 @@ void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
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;
union tcp_ao_addr *addr;
bool match = false;
int ret = -ENOMEM;
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;
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;
}
hlist_for_each_entry_rcu(key, &ao->head, node) {
if (tcp_ao_key_cmp(key, 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;
}
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 */

15
net/ipv4/tcp_input.c
View file

@ -7045,6 +7045,10 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
struct flowi fl;
u8 syncookies;
#ifdef CONFIG_TCP_AO
const struct tcp_ao_hdr *aoh;
#endif
syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies);
/* TW buckets are converted to open requests without
@ -7131,6 +7135,17 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
inet_rsk(req)->ecn_ok = 0;
}
#ifdef CONFIG_TCP_AO
if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
goto drop_and_release; /* Invalid TCP options */
if (aoh) {
tcp_rsk(req)->maclen = aoh->length - sizeof(struct tcp_ao_hdr);
tcp_rsk(req)->ao_rcv_next = aoh->keyid;
tcp_rsk(req)->ao_keyid = aoh->rnext_keyid;
} else {
tcp_rsk(req)->maclen = 0;
}
#endif
tcp_rsk(req)->snt_isn = isn;
tcp_rsk(req)->txhash = net_tx_rndhash();
tcp_rsk(req)->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;

66
net/ipv4/tcp_ipv4.c
View file

@ -1072,13 +1072,47 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 :
tcp_sk(sk)->snd_nxt;
/* RFC 7323 2.3
* The window field (SEG.WND) of every outgoing segment, with the
* exception of <SYN> segments, MUST be right-shifted by
* Rcv.Wind.Shift bits:
*/
#ifdef CONFIG_TCP_AO
if (tcp_rsk_used_ao(req)) {
const union tcp_md5_addr *addr;
const struct tcp_ao_hdr *aoh;
/* Invalid TCP option size or twice included auth */
if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
return;
if (!aoh)
return;
addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
key.ao_key = tcp_ao_do_lookup(sk, addr, AF_INET,
aoh->rnext_keyid, -1);
if (unlikely(!key.ao_key)) {
/* Send ACK with any matching MKT for the peer */
key.ao_key = tcp_ao_do_lookup(sk, addr, AF_INET, -1, -1);
/* Matching key disappeared (user removed the key?)
* let the handshake timeout.
*/
if (!key.ao_key) {
net_info_ratelimited("TCP-AO key for (%pI4, %d)->(%pI4, %d) suddenly disappeared, won't ACK new connection\n",
addr,
ntohs(tcp_hdr(skb)->source),
&ip_hdr(skb)->daddr,
ntohs(tcp_hdr(skb)->dest));
return;
}
}
key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
if (!key.traffic_key)
return;
key.type = TCP_KEY_AO;
key.rcv_next = aoh->keyid;
tcp_v4_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
#else
if (0) {
#endif
#ifdef CONFIG_TCP_MD5SIG
if (static_branch_unlikely(&tcp_md5_needed.key)) {
} else if (static_branch_unlikely(&tcp_md5_needed.key)) {
const union tcp_md5_addr *addr;
int l3index;
@ -1087,8 +1121,14 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
key.md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
if (key.md5_key)
key.type = TCP_KEY_MD5;
}
#endif
}
/* RFC 7323 2.3
* The window field (SEG.WND) of every outgoing segment, with the
* exception of <SYN> segments, MUST be right-shifted by
* Rcv.Wind.Shift bits:
*/
tcp_v4_send_ack(sk, skb, seq,
tcp_rsk(req)->rcv_nxt,
req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
@ -1098,6 +1138,8 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
ip_hdr(skb)->tos,
READ_ONCE(tcp_rsk(req)->txhash));
if (tcp_key_is_ao(&key))
kfree(key.traffic_key);
}
/*
@ -1636,6 +1678,10 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
.req_md5_lookup = tcp_v4_md5_lookup,
.calc_md5_hash = tcp_v4_md5_hash_skb,
#endif
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v4_ao_lookup_rsk,
.ao_calc_key = tcp_v4_ao_calc_key_rsk,
#endif
#ifdef CONFIG_SYN_COOKIES
.cookie_init_seq = cookie_v4_init_sequence,
#endif
@ -1737,12 +1783,16 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
/* Copy over the MD5 key from the original socket */
addr = (union tcp_md5_addr *)&newinet->inet_daddr;
key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
if (key) {
if (key && !tcp_rsk_used_ao(req)) {
if (tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key))
goto put_and_exit;
sk_gso_disable(newsk);
}
#endif
#ifdef CONFIG_TCP_AO
if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET))
goto put_and_exit; /* OOM, release back memory */
#endif
if (__inet_inherit_port(sk, newsk) < 0)
goto put_and_exit;

10
net/ipv4/tcp_minisocks.c
View file

@ -506,6 +506,9 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
const struct tcp_sock *oldtp;
struct tcp_sock *newtp;
u32 seq;
#ifdef CONFIG_TCP_AO
struct tcp_ao_key *ao_key;
#endif
if (!newsk)
return NULL;
@ -594,6 +597,13 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
#ifdef CONFIG_TCP_MD5SIG
newtp->md5sig_info = NULL; /*XXX*/
#endif
#ifdef CONFIG_TCP_AO
newtp->ao_info = NULL;
ao_key = treq->af_specific->ao_lookup(sk, req,
tcp_rsk(req)->ao_keyid, -1);
if (ao_key)
newtp->tcp_header_len += tcp_ao_len(ao_key);
#endif
if (skb->len >= TCP_MSS_DEFAULT + newtp->tcp_header_len)
newicsk->icsk_ack.last_seg_size = skb->len - newtp->tcp_header_len;
newtp->rx_opt.mss_clamp = req->mss;

37
net/ipv4/tcp_output.c
View file

@ -615,6 +615,7 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb,
* (but it may well be that other scenarios fail similarly).
*/
static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
const struct tcp_request_sock *tcprsk,
struct tcp_out_options *opts,
struct tcp_key *key)
{
@ -629,20 +630,28 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
ptr += 4;
} else if (tcp_key_is_ao(key)) {
#ifdef CONFIG_TCP_AO
struct tcp_ao_key *rnext_key;
struct tcp_ao_info *ao_info;
u8 maclen;
u8 maclen = tcp_ao_maclen(key->ao_key);
ao_info = rcu_dereference_check(tp->ao_info,
if (tcprsk) {
u8 aolen = maclen + sizeof(struct tcp_ao_hdr);
*ptr++ = htonl((TCPOPT_AO << 24) | (aolen << 16) |
(tcprsk->ao_keyid << 8) |
(tcprsk->ao_rcv_next));
} else {
struct tcp_ao_key *rnext_key;
struct tcp_ao_info *ao_info;
ao_info = rcu_dereference_check(tp->ao_info,
lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
rnext_key = READ_ONCE(ao_info->rnext_key);
if (WARN_ON_ONCE(!rnext_key))
goto out_ao;
maclen = tcp_ao_maclen(key->ao_key);
*ptr++ = htonl((TCPOPT_AO << 24) |
(tcp_ao_len(key->ao_key) << 16) |
(key->ao_key->sndid << 8) |
(rnext_key->rcvid));
rnext_key = READ_ONCE(ao_info->rnext_key);
if (WARN_ON_ONCE(!rnext_key))
goto out_ao;
*ptr++ = htonl((TCPOPT_AO << 24) |
(tcp_ao_len(key->ao_key) << 16) |
(key->ao_key->sndid << 8) |
(rnext_key->rcvid));
}
opts->hash_location = (__u8 *)ptr;
ptr += maclen / sizeof(*ptr);
if (unlikely(maclen % sizeof(*ptr))) {
@ -1386,7 +1395,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
th->window = htons(min(tp->rcv_wnd, 65535U));
}
tcp_options_write(th, tp, &opts, &key);
tcp_options_write(th, tp, NULL, &opts, &key);
if (tcp_key_is_md5(&key)) {
#ifdef CONFIG_TCP_MD5SIG
@ -3729,7 +3738,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
th->window = htons(min(req->rsk_rcv_wnd, 65535U));
tcp_options_write(th, NULL, &opts, &key);
tcp_options_write(th, NULL, NULL, &opts, &key);
th->doff = (tcp_header_size >> 2);
TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);

2
net/ipv6/syncookies.c
View file

@ -214,6 +214,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
treq->snt_isn = cookie;
treq->ts_off = 0;
treq->txhash = net_tx_rndhash();
tcp_ao_syncookie(sk, skb, treq, AF_INET6);
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;

38
net/ipv6/tcp_ao.c
View file

@ -49,6 +49,17 @@ static int tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
return err;
}
int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
const struct sk_buff *skb,
__be32 sisn, __be32 disn)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
const struct tcphdr *th = tcp_hdr(skb);
return tcp_v6_ao_calc_key(mkt, key, &iph->saddr, &iph->daddr,
th->source, th->dest, sisn, disn);
}
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send)
@ -63,9 +74,21 @@ int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
htons(sk->sk_num), disn, sisn);
}
static struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
const struct in6_addr *addr,
int sndid, int rcvid)
int tcp_v6_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_v6_ao_calc_key(mkt, key,
&ireq->ir_v6_loc_addr, &ireq->ir_v6_rmt_addr,
htons(ireq->ir_num), ireq->ir_rmt_port,
htonl(tcp_rsk(req)->snt_isn),
htonl(tcp_rsk(req)->rcv_isn));
}
struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
const struct in6_addr *addr,
int sndid, int rcvid)
{
return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)addr, AF_INET6,
sndid, rcvid);
@ -80,6 +103,15 @@ struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
}
struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid)
{
struct in6_addr *addr = &inet_rsk(req)->ir_v6_rmt_addr;
return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
}
int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
const struct in6_addr *daddr,
const struct in6_addr *saddr, int nbytes)

73
net/ipv6/tcp_ipv6.c
View file

@ -836,6 +836,10 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
.req_md5_lookup = tcp_v6_md5_lookup,
.calc_md5_hash = tcp_v6_md5_hash_skb,
#endif
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v6_ao_lookup_rsk,
.ao_calc_key = tcp_v6_ao_calc_key_rsk,
#endif
#ifdef CONFIG_SYN_COOKIES
.cookie_init_seq = cookie_v6_init_sequence,
#endif
@ -1192,16 +1196,54 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
{
struct tcp_key key = {};
#ifdef CONFIG_TCP_AO
if (tcp_rsk_used_ao(req)) {
const struct in6_addr *addr = &ipv6_hdr(skb)->saddr;
const struct tcp_ao_hdr *aoh;
int l3index;
l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
/* Invalid TCP option size or twice included auth */
if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
return;
if (!aoh)
return;
key.ao_key = tcp_v6_ao_do_lookup(sk, addr, aoh->rnext_keyid, -1);
if (unlikely(!key.ao_key)) {
/* Send ACK with any matching MKT for the peer */
key.ao_key = tcp_v6_ao_do_lookup(sk, addr, -1, -1);
/* Matching key disappeared (user removed the key?)
* let the handshake timeout.
*/
if (!key.ao_key) {
net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n",
addr,
ntohs(tcp_hdr(skb)->source),
&ipv6_hdr(skb)->daddr,
ntohs(tcp_hdr(skb)->dest));
return;
}
}
key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
if (!key.traffic_key)
return;
key.type = TCP_KEY_AO;
key.rcv_next = aoh->keyid;
tcp_v6_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
#else
if (0) {
#endif
#ifdef CONFIG_TCP_MD5SIG
if (static_branch_unlikely(&tcp_md5_needed.key)) {
} else if (static_branch_unlikely(&tcp_md5_needed.key)) {
int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr,
l3index);
if (key.md5_key)
key.type = TCP_KEY_MD5;
}
#endif
}
/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
* sk->sk_state == TCP_SYN_RECV -> for Fast Open.
@ -1220,6 +1262,8 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
&key, ipv6_get_dsfield(ipv6_hdr(skb)), 0,
READ_ONCE(sk->sk_priority),
READ_ONCE(tcp_rsk(req)->txhash));
if (tcp_key_is_ao(&key))
kfree(key.traffic_key);
}
@ -1449,19 +1493,26 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
#ifdef CONFIG_TCP_MD5SIG
l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
/* Copy over the MD5 key from the original socket */
key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
if (key) {
const union tcp_md5_addr *addr;
if (!tcp_rsk_used_ao(req)) {
/* Copy over the MD5 key from the original socket */
key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
if (key) {
const union tcp_md5_addr *addr;
addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
inet_csk_prepare_forced_close(newsk);
tcp_done(newsk);
goto out;
addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
inet_csk_prepare_forced_close(newsk);
tcp_done(newsk);
goto out;
}
}
}
#endif
#ifdef CONFIG_TCP_AO
/* Copy over tcp_ao_info if any */
if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6))
goto out; /* OOM */
#endif
if (__inet_inherit_port(sk, newsk) < 0) {
inet_csk_prepare_forced_close(newsk);