67fa83f7c8
Similarly to TCP-MD5, add a static key to TCP-AO that is patched out when there are no keys on a machine and dynamically enabled with the first setsockopt(TCP_AO) adds a key on any socket. The static key is as well dynamically disabled later when the socket is destructed. The lifetime of enabled static key here is the same as ao_info: it is enabled on allocation, passed over from full socket to twsk and destructed when ao_info is scheduled for destruction. Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2229 lines
59 KiB
C
2229 lines
59 KiB
C
// 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>
|
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* Francesco Ruggeri <fruggeri@arista.com>
|
||
* Salam Noureddine <noureddine@arista.com>
|
||
*/
|
||
#define pr_fmt(fmt) "TCP: " fmt
|
||
|
||
#include <crypto/hash.h>
|
||
#include <linux/inetdevice.h>
|
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#include <linux/tcp.h>
|
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|
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#include <net/tcp.h>
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#include <net/ipv6.h>
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#include <net/icmp.h>
|
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|
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DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ);
|
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|
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int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
|
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unsigned int len, struct tcp_sigpool *hp)
|
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{
|
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struct scatterlist sg;
|
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int ret;
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|
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if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp->req),
|
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mkt->key, mkt->keylen))
|
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goto clear_hash;
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ret = crypto_ahash_init(hp->req);
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if (ret)
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goto clear_hash;
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|
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sg_init_one(&sg, ctx, len);
|
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ahash_request_set_crypt(hp->req, &sg, key, len);
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crypto_ahash_update(hp->req);
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ret = crypto_ahash_final(hp->req);
|
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if (ret)
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goto clear_hash;
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|
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return 0;
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clear_hash:
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memset(key, 0, tcp_ao_digest_size(mkt));
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return 1;
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}
|
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|
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bool tcp_ao_ignore_icmp(const struct sock *sk, int family, int type, int code)
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{
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bool ignore_icmp = false;
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struct tcp_ao_info *ao;
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|
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if (!static_branch_unlikely(&tcp_ao_needed.key))
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return false;
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|
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/* RFC5925, 7.8:
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* >> A TCP-AO implementation MUST default to ignore incoming ICMPv4
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* messages of Type 3 (destination unreachable), Codes 2-4 (protocol
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* unreachable, port unreachable, and fragmentation needed -- ’hard
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* errors’), and ICMPv6 Type 1 (destination unreachable), Code 1
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* (administratively prohibited) and Code 4 (port unreachable) intended
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* for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN-
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* WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs.
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*/
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if (family == AF_INET) {
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if (type != ICMP_DEST_UNREACH)
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return false;
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if (code < ICMP_PROT_UNREACH || code > ICMP_FRAG_NEEDED)
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return false;
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} else {
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if (type != ICMPV6_DEST_UNREACH)
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return false;
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if (code != ICMPV6_ADM_PROHIBITED && code != ICMPV6_PORT_UNREACH)
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return false;
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}
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rcu_read_lock();
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switch (sk->sk_state) {
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case TCP_TIME_WAIT:
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ao = rcu_dereference(tcp_twsk(sk)->ao_info);
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break;
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case TCP_SYN_SENT:
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case TCP_SYN_RECV:
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case TCP_LISTEN:
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case TCP_NEW_SYN_RECV:
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/* RFC5925 specifies to ignore ICMPs *only* on connections
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* in synchronized states.
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*/
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rcu_read_unlock();
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return false;
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default:
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ao = rcu_dereference(tcp_sk(sk)->ao_info);
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}
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if (ao && !ao->accept_icmps) {
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ignore_icmp = true;
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__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAODROPPEDICMPS);
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atomic64_inc(&ao->counters.dropped_icmp);
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}
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rcu_read_unlock();
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return ignore_icmp;
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}
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/* Optimized version of tcp_ao_do_lookup(): only for sockets for which
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* it's known that the keys in ao_info are matching peer's
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* family/address/VRF/etc.
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*/
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struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
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int sndid, int rcvid)
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{
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struct tcp_ao_key *key;
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hlist_for_each_entry_rcu(key, &ao->head, node) {
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if ((sndid >= 0 && key->sndid != sndid) ||
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(rcvid >= 0 && key->rcvid != rcvid))
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continue;
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return key;
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}
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return NULL;
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}
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static int ipv4_prefix_cmp(const struct in_addr *addr1,
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const struct in_addr *addr2,
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unsigned int prefixlen)
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{
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__be32 mask = inet_make_mask(prefixlen);
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__be32 a1 = addr1->s_addr & mask;
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__be32 a2 = addr2->s_addr & mask;
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if (a1 == a2)
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return 0;
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return memcmp(&a1, &a2, sizeof(a1));
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}
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static int __tcp_ao_key_cmp(const struct tcp_ao_key *key,
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const union tcp_ao_addr *addr, u8 prefixlen,
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int family, int sndid, int rcvid)
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{
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if (sndid >= 0 && key->sndid != sndid)
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return (key->sndid > sndid) ? 1 : -1;
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if (rcvid >= 0 && key->rcvid != rcvid)
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return (key->rcvid > rcvid) ? 1 : -1;
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if (family == AF_UNSPEC)
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return 0;
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if (key->family != family)
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return (key->family > family) ? 1 : -1;
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if (family == AF_INET) {
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if (ntohl(key->addr.a4.s_addr) == INADDR_ANY)
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return 0;
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if (ntohl(addr->a4.s_addr) == INADDR_ANY)
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return 0;
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return ipv4_prefix_cmp(&key->addr.a4, &addr->a4, prefixlen);
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#if IS_ENABLED(CONFIG_IPV6)
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} else {
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if (ipv6_addr_any(&key->addr.a6) || ipv6_addr_any(&addr->a6))
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return 0;
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if (ipv6_prefix_equal(&key->addr.a6, &addr->a6, prefixlen))
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return 0;
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return memcmp(&key->addr.a6, &addr->a6, sizeof(addr->a6));
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#endif
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}
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return -1;
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}
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static int tcp_ao_key_cmp(const struct tcp_ao_key *key,
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const union tcp_ao_addr *addr, u8 prefixlen,
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int family, int sndid, int rcvid)
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{
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#if IS_ENABLED(CONFIG_IPV6)
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if (family == AF_INET6 && ipv6_addr_v4mapped(&addr->a6)) {
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__be32 addr4 = addr->a6.s6_addr32[3];
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return __tcp_ao_key_cmp(key, (union tcp_ao_addr *)&addr4,
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prefixlen, AF_INET, sndid, rcvid);
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}
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#endif
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return __tcp_ao_key_cmp(key, addr, prefixlen, family, sndid, rcvid);
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}
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static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk,
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const union tcp_ao_addr *addr, int family, u8 prefix,
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int sndid, int rcvid)
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{
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struct tcp_ao_key *key;
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struct tcp_ao_info *ao;
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if (!static_branch_unlikely(&tcp_ao_needed.key))
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return NULL;
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ao = rcu_dereference_check(tcp_sk(sk)->ao_info,
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lockdep_sock_is_held(sk));
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if (!ao)
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return NULL;
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hlist_for_each_entry_rcu(key, &ao->head, node) {
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u8 prefixlen = min(prefix, key->prefixlen);
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if (!tcp_ao_key_cmp(key, addr, prefixlen, family, sndid, rcvid))
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return key;
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}
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return NULL;
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}
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struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
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const union tcp_ao_addr *addr,
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int family, int sndid, int rcvid)
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{
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return __tcp_ao_do_lookup(sk, addr, family, U8_MAX, sndid, rcvid);
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}
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static struct tcp_ao_info *tcp_ao_alloc_info(gfp_t flags)
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{
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struct tcp_ao_info *ao;
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ao = kzalloc(sizeof(*ao), flags);
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if (!ao)
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return NULL;
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INIT_HLIST_HEAD(&ao->head);
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refcount_set(&ao->refcnt, 1);
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return ao;
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}
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static void tcp_ao_link_mkt(struct tcp_ao_info *ao, struct tcp_ao_key *mkt)
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{
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hlist_add_head_rcu(&mkt->node, &ao->head);
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}
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static struct tcp_ao_key *tcp_ao_copy_key(struct sock *sk,
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struct tcp_ao_key *key)
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{
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struct tcp_ao_key *new_key;
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new_key = sock_kmalloc(sk, tcp_ao_sizeof_key(key),
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GFP_ATOMIC);
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if (!new_key)
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return NULL;
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*new_key = *key;
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INIT_HLIST_NODE(&new_key->node);
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tcp_sigpool_get(new_key->tcp_sigpool_id);
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atomic64_set(&new_key->pkt_good, 0);
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atomic64_set(&new_key->pkt_bad, 0);
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return new_key;
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}
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static void tcp_ao_key_free_rcu(struct rcu_head *head)
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{
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struct tcp_ao_key *key = container_of(head, struct tcp_ao_key, rcu);
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tcp_sigpool_release(key->tcp_sigpool_id);
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kfree_sensitive(key);
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}
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void tcp_ao_destroy_sock(struct sock *sk, bool twsk)
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{
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struct tcp_ao_info *ao;
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struct tcp_ao_key *key;
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struct hlist_node *n;
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if (twsk) {
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ao = rcu_dereference_protected(tcp_twsk(sk)->ao_info, 1);
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tcp_twsk(sk)->ao_info = NULL;
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} else {
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ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1);
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tcp_sk(sk)->ao_info = NULL;
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}
|
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|
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if (!ao || !refcount_dec_and_test(&ao->refcnt))
|
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return;
|
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|
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hlist_for_each_entry_safe(key, n, &ao->head, node) {
|
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hlist_del_rcu(&key->node);
|
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if (!twsk)
|
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atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
|
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call_rcu(&key->rcu, tcp_ao_key_free_rcu);
|
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}
|
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|
||
kfree_rcu(ao, rcu);
|
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static_branch_slow_dec_deferred(&tcp_ao_needed);
|
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}
|
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|
||
void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp)
|
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{
|
||
struct tcp_ao_info *ao_info = rcu_dereference_protected(tp->ao_info, 1);
|
||
|
||
if (ao_info) {
|
||
struct tcp_ao_key *key;
|
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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)
|
||
{
|
||
int err, len = th->doff << 2;
|
||
struct scatterlist sg;
|
||
u8 *hdr = hp->scratch;
|
||
|
||
/* 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)
|
||
{
|
||
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)
|
||
{
|
||
union tcp_ao_addr *addr = (union tcp_ao_addr *)&addr_sk->sk_daddr;
|
||
|
||
return tcp_ao_do_lookup(sk, 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, 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)
|
||
{
|
||
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 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)
|
||
{
|
||
u8 maclen = aoh->length - sizeof(struct tcp_ao_hdr);
|
||
const struct tcphdr *th = tcp_hdr(skb);
|
||
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);
|
||
tcp_hash_fail("AO hash wrong length", family, skb,
|
||
"%u != %d", maclen, tcp_ao_maclen(key));
|
||
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);
|
||
tcp_hash_fail("AO hash mismatch", family, skb, "");
|
||
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,
|
||
const struct tcp_ao_hdr *aoh)
|
||
{
|
||
const struct tcphdr *th = tcp_hdr(skb);
|
||
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;
|
||
u32 sne = 0;
|
||
|
||
info = rcu_dereference(tcp_sk(sk)->ao_info);
|
||
if (!info) {
|
||
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
|
||
tcp_hash_fail("AO key not found", family, skb,
|
||
"keyid: %u", aoh->keyid);
|
||
return SKB_DROP_REASON_TCP_AOUNEXPECTED;
|
||
}
|
||
|
||
if (unlikely(th->syn)) {
|
||
sisn = th->seq;
|
||
disn = 0;
|
||
}
|
||
|
||
/* Fast-path */
|
||
if (likely((1 << sk->sk_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);
|
||
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)) {
|
||
/* 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;
|
||
}
|
||
|
||
/* 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);
|
||
if (!key)
|
||
goto key_not_found;
|
||
|
||
if (th->syn && !th->ack)
|
||
goto verify_hash;
|
||
|
||
if ((1 << sk->sk_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 << sk->sk_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", sk->sk_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);
|
||
kfree(traffic_key);
|
||
return ret;
|
||
|
||
key_not_found:
|
||
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
|
||
atomic64_inc(&info->counters.key_not_found);
|
||
tcp_hash_fail("Requested by the peer AO key id not found",
|
||
family, skb, "");
|
||
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;
|
||
union tcp_ao_addr *addr;
|
||
struct tcp_ao_key *key;
|
||
int family;
|
||
|
||
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;
|
||
|
||
hlist_for_each_entry_rcu(key, &ao_info->head, node) {
|
||
if (!tcp_ao_key_cmp(key, 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(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;
|
||
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;
|
||
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;
|
||
}
|
||
|
||
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;
|
||
}
|
||
|
||
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 - wscale - sackperm),
|
||
* 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_TSTAMP_ALIGNED;
|
||
syn_tcp_option_space -= TCPOLEN_WSCALE_ALIGNED;
|
||
syn_tcp_option_space -= TCPOLEN_SACKPERM_ALIGNED;
|
||
if (tcp_ao_len(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);
|
||
}
|
||
|
||
#define TCP_AO_KEYF_ALL (TCP_AO_KEYF_EXCLUDE_OPT)
|
||
|
||
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);
|
||
if (crypto_ahash_alignmask(tfm) > TCP_AO_KEY_ALIGN) {
|
||
err = -EOPNOTSUPP;
|
||
goto err_pool_end;
|
||
}
|
||
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_pool_end:
|
||
tcp_sigpool_end(&hp);
|
||
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;
|
||
bool first = false;
|
||
int ret;
|
||
|
||
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;
|
||
}
|
||
|
||
/* Don't allow keys for peers that have a matching TCP-MD5 key */
|
||
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, addr, family,
|
||
cmd.prefix, -1, cmd.rcvid))
|
||
return -EEXIST;
|
||
if (__tcp_ao_do_lookup(sk, 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;
|
||
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;
|
||
|
||
/* Change this condition if we allow adding keys in states
|
||
* like close_wait, syn_sent or fin_wait...
|
||
*/
|
||
if (sk->sk_state == TCP_ESTABLISHED)
|
||
tcp_ao_cache_traffic_keys(sk, ao_info, 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;
|
||
}
|
||
|
||
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;
|
||
struct tcp_ao_info *ao_info;
|
||
union tcp_ao_addr *addr;
|
||
struct tcp_ao_del cmd;
|
||
int addr_len;
|
||
__u8 prefix;
|
||
u16 port;
|
||
int err;
|
||
|
||
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;
|
||
}
|
||
|
||
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 (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) {
|
||
ao_info = tcp_ao_alloc_info(GFP_KERNEL);
|
||
if (!ao_info)
|
||
return -ENOMEM;
|
||
first = true;
|
||
}
|
||
|
||
if (cmd.ao_required && tcp_ao_required_verify(sk))
|
||
return -EKEYREJECTED;
|
||
|
||
/* 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;
|
||
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 */
|
||
int err, user_len;
|
||
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.reserved != 0)
|
||
return -EINVAL;
|
||
|
||
max_keys = opt_in.nkeys;
|
||
|
||
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, 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.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;
|
||
}
|
||
|