diff options
| -rw-r--r-- | include/linux/sockptr.h | 23 | ||||
| -rw-r--r-- | include/net/tcp.h | 3 | ||||
| -rw-r--r-- | include/net/tcp_ao.h | 17 | ||||
| -rw-r--r-- | include/uapi/linux/tcp.h | 46 | ||||
| -rw-r--r-- | net/ipv4/Makefile | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 17 | ||||
| -rw-r--r-- | net/ipv4/tcp_ao.c | 794 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 10 | ||||
| -rw-r--r-- | net/ipv6/Makefile | 1 | ||||
| -rw-r--r-- | net/ipv6/tcp_ao.c | 19 | ||||
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 39 |
11 files changed, 952 insertions, 18 deletions
diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h index bae5e2369b4f..307961b41541 100644 --- a/include/linux/sockptr.h +++ b/include/linux/sockptr.h @@ -55,6 +55,29 @@ static inline int copy_from_sockptr(void *dst, sockptr_t src, size_t size) return copy_from_sockptr_offset(dst, src, 0, size); } +static inline int copy_struct_from_sockptr(void *dst, size_t ksize, + sockptr_t src, size_t usize) +{ + size_t size = min(ksize, usize); + size_t rest = max(ksize, usize) - size; + + if (!sockptr_is_kernel(src)) + return copy_struct_from_user(dst, ksize, src.user, size); + + if (usize < ksize) { + memset(dst + size, 0, rest); + } else if (usize > ksize) { + char *p = src.kernel; + + while (rest--) { + if (*p++) + return -E2BIG; + } + } + memcpy(dst, src.kernel, size); + return 0; +} + static inline int copy_to_sockptr_offset(sockptr_t dst, size_t offset, const void *src, size_t size) { diff --git a/include/net/tcp.h b/include/net/tcp.h index 3153712faa3d..ff204471d451 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2175,6 +2175,9 @@ struct tcp_sock_af_ops { sockptr_t optval, int optlen); #endif +#ifdef CONFIG_TCP_AO + int (*ao_parse)(struct sock *sk, int optname, sockptr_t optval, int optlen); +#endif }; struct tcp_request_sock_ops { diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index af76e1c47bea..a81e40fd255a 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -81,10 +81,25 @@ struct tcp_ao_info { */ struct tcp_ao_key *current_key; struct tcp_ao_key *rnext_key; - u32 flags; + u32 ao_required :1, + __unused :31; __be32 lisn; __be32 risn; struct rcu_head rcu; }; +#ifdef CONFIG_TCP_AO +int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family, + sockptr_t optval, int optlen); +void tcp_ao_destroy_sock(struct sock *sk); +/* ipv4 specific functions */ +int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); +/* ipv6 specific functions */ +int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); +#else +static inline void tcp_ao_destroy_sock(struct sock *sk) +{ +} +#endif + #endif /* _TCP_AO_H */ diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index 74a1267baac5..fa49f03e62fe 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -129,6 +129,9 @@ enum { #define TCP_TX_DELAY 37 /* delay outgoing packets by XX usec */ +#define TCP_AO_ADD_KEY 38 /* Add/Set MKT */ +#define TCP_AO_DEL_KEY 39 /* Delete MKT */ +#define TCP_AO_INFO 40 /* Modify TCP-AO per-socket options */ #define TCP_REPAIR_ON 1 #define TCP_REPAIR_OFF 0 @@ -363,6 +366,49 @@ struct tcp_diag_md5sig { #define TCP_AO_MAXKEYLEN 80 +#define TCP_AO_KEYF_IFINDEX (1 << 0) /* L3 ifindex for VRF */ + +struct tcp_ao_add { /* setsockopt(TCP_AO_ADD_KEY) */ + struct __kernel_sockaddr_storage addr; /* peer's address for the key */ + char alg_name[64]; /* crypto hash algorithm to use */ + __s32 ifindex; /* L3 dev index for VRF */ + __u32 set_current :1, /* set key as Current_key at once */ + set_rnext :1, /* request it from peer with RNext_key */ + reserved :30; /* must be 0 */ + __u16 reserved2; /* padding, must be 0 */ + __u8 prefix; /* peer's address prefix */ + __u8 sndid; /* SendID for outgoing segments */ + __u8 rcvid; /* RecvID to match for incoming seg */ + __u8 maclen; /* length of authentication code (hash) */ + __u8 keyflags; /* see TCP_AO_KEYF_ */ + __u8 keylen; /* length of ::key */ + __u8 key[TCP_AO_MAXKEYLEN]; +} __attribute__((aligned(8))); + +struct tcp_ao_del { /* setsockopt(TCP_AO_DEL_KEY) */ + struct __kernel_sockaddr_storage addr; /* peer's address for the key */ + __s32 ifindex; /* L3 dev index for VRF */ + __u32 set_current :1, /* corresponding ::current_key */ + set_rnext :1, /* corresponding ::rnext */ + reserved :30; /* must be 0 */ + __u16 reserved2; /* padding, must be 0 */ + __u8 prefix; /* peer's address prefix */ + __u8 sndid; /* SendID for outgoing segments */ + __u8 rcvid; /* RecvID to match for incoming seg */ + __u8 current_key; /* KeyID to set as Current_key */ + __u8 rnext; /* KeyID to set as Rnext_key */ + __u8 keyflags; /* see TCP_AO_KEYF_ */ +} __attribute__((aligned(8))); + +struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO) */ + __u32 set_current :1, /* corresponding ::current_key */ + set_rnext :1, /* corresponding ::rnext */ + ao_required :1, /* don't accept non-AO connects */ + reserved :29; /* must be 0 */ + __u8 current_key; /* KeyID to set as Current_key */ + __u8 rnext; /* KeyID to set as Rnext_key */ +} __attribute__((aligned(8))); + /* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */ #define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1 diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile index cd760793cfcb..e144a02a6a61 100644 --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile @@ -69,6 +69,7 @@ obj-$(CONFIG_NETLABEL) += cipso_ipv4.o obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \ xfrm4_output.o xfrm4_protocol.o +obj-$(CONFIG_TCP_AO) += tcp_ao.o ifeq ($(CONFIG_BPF_JIT),y) obj-$(CONFIG_BPF_SYSCALL) += bpf_tcp_ca.o diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index dca9ca2f1081..b6faee8a1e67 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3593,6 +3593,23 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, __tcp_sock_set_quickack(sk, val); break; +#ifdef CONFIG_TCP_AO + case TCP_AO_ADD_KEY: + case TCP_AO_DEL_KEY: + case TCP_AO_INFO: { + /* If this is the first TCP-AO setsockopt() on the socket, + * sk_state has to be LISTEN or CLOSE + */ + if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) || + rcu_dereference_protected(tcp_sk(sk)->ao_info, + lockdep_sock_is_held(sk))) + err = tp->af_specific->ao_parse(sk, optname, optval, + optlen); + else + err = -EISCONN; + break; + } +#endif #ifdef CONFIG_TCP_MD5SIG case TCP_MD5SIG: case TCP_MD5SIG_EXT: diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c new file mode 100644 index 000000000000..3c2d005a37ce --- /dev/null +++ b/net/ipv4/tcp_ao.c @@ -0,0 +1,794 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP Authentication Option (TCP-AO). + * See RFC5925. + * + * Authors: Dmitry Safonov <dima@arista.com> + * Francesco Ruggeri <fruggeri@arista.com> + * Salam Noureddine <noureddine@arista.com> + */ +#define pr_fmt(fmt) "TCP: " fmt + +#include <crypto/hash.h> +#include <linux/inetdevice.h> +#include <linux/tcp.h> + +#include <net/tcp.h> +#include <net/ipv6.h> + +/* Optimized version of tcp_ao_do_lookup(): only for sockets for which + * it's known that the keys in ao_info are matching peer's + * family/address/VRF/etc. + */ +static struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao, + int sndid, int rcvid) +{ + struct tcp_ao_key *key; + + hlist_for_each_entry_rcu(key, &ao->head, node) { + if ((sndid >= 0 && key->sndid != sndid) || + (rcvid >= 0 && key->rcvid != rcvid)) + continue; + return key; + } + + return NULL; +} + +static int ipv4_prefix_cmp(const struct in_addr *addr1, + const struct in_addr *addr2, + unsigned int prefixlen) +{ + __be32 mask = inet_make_mask(prefixlen); + __be32 a1 = addr1->s_addr & mask; + __be32 a2 = addr2->s_addr & mask; + + if (a1 == a2) + return 0; + return memcmp(&a1, &a2, sizeof(a1)); +} + +static int __tcp_ao_key_cmp(const struct tcp_ao_key *key, + const union tcp_ao_addr *addr, u8 prefixlen, + int family, int sndid, int rcvid) +{ + if (sndid >= 0 && key->sndid != sndid) + return (key->sndid > sndid) ? 1 : -1; + if (rcvid >= 0 && key->rcvid != rcvid) + return (key->rcvid > rcvid) ? 1 : -1; + + if (family == AF_UNSPEC) + return 0; + if (key->family != family) + return (key->family > family) ? 1 : -1; + + if (family == AF_INET) { + if (ntohl(key->addr.a4.s_addr) == INADDR_ANY) + return 0; + if (ntohl(addr->a4.s_addr) == INADDR_ANY) + return 0; + return ipv4_prefix_cmp(&key->addr.a4, &addr->a4, prefixlen); +#if IS_ENABLED(CONFIG_IPV6) + } else { + if (ipv6_addr_any(&key->addr.a6) || ipv6_addr_any(&addr->a6)) + return 0; + if (ipv6_prefix_equal(&key->addr.a6, &addr->a6, prefixlen)) + return 0; + return memcmp(&key->addr.a6, &addr->a6, sizeof(addr->a6)); +#endif + } + return -1; +} + +static int tcp_ao_key_cmp(const struct tcp_ao_key *key, + const union tcp_ao_addr *addr, u8 prefixlen, + int family, int sndid, int rcvid) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (family == AF_INET6 && ipv6_addr_v4mapped(&addr->a6)) { + __be32 addr4 = addr->a6.s6_addr32[3]; + + return __tcp_ao_key_cmp(key, (union tcp_ao_addr *)&addr4, + prefixlen, AF_INET, sndid, rcvid); + } +#endif + return __tcp_ao_key_cmp(key, addr, prefixlen, family, sndid, rcvid); +} + +static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk, + const union tcp_ao_addr *addr, int family, u8 prefix, + int sndid, int rcvid) +{ + struct tcp_ao_key *key; + struct tcp_ao_info *ao; + + ao = rcu_dereference_check(tcp_sk(sk)->ao_info, + lockdep_sock_is_held(sk)); + if (!ao) + return NULL; + + hlist_for_each_entry_rcu(key, &ao->head, node) { + u8 prefixlen = min(prefix, key->prefixlen); + + if (!tcp_ao_key_cmp(key, addr, prefixlen, family, sndid, rcvid)) + return key; + } + return NULL; +} + +static struct tcp_ao_info *tcp_ao_alloc_info(gfp_t flags) +{ + struct tcp_ao_info *ao; + + ao = kzalloc(sizeof(*ao), flags); + if (!ao) + return NULL; + INIT_HLIST_HEAD(&ao->head); + + return ao; +} + +static void tcp_ao_link_mkt(struct tcp_ao_info *ao, struct tcp_ao_key *mkt) +{ + hlist_add_head_rcu(&mkt->node, &ao->head); +} + +static void tcp_ao_key_free_rcu(struct rcu_head *head) +{ + struct tcp_ao_key *key = container_of(head, struct tcp_ao_key, rcu); + + tcp_sigpool_release(key->tcp_sigpool_id); + kfree_sensitive(key); +} + +void tcp_ao_destroy_sock(struct sock *sk) +{ + struct tcp_ao_info *ao; + struct tcp_ao_key *key; + struct hlist_node *n; + + ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1); + tcp_sk(sk)->ao_info = NULL; + + if (!ao) + return; + + hlist_for_each_entry_safe(key, n, &ao->head, node) { + 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); + } + + kfree_rcu(ao, rcu); +} + +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)); + } + return ERR_PTR(-ESOCKTNOSUPPORT); +} + +#define TCP_AO_KEYF_ALL (0) + +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; + } + + 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; + + ret = tcp_ao_parse_crypto(&cmd, key); + if (ret < 0) + goto err_free_sock; + + tcp_ao_link_mkt(ao_info, key); + if (first) { + 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, + struct tcp_ao_key *key, + struct tcp_ao_key *new_current, + struct tcp_ao_key *new_rnext) +{ + int err; + + hlist_del_rcu(&key->node); + + /* 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). + */ + 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 (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, key, + new_current, new_rnext); + } + return -ENOENT; +} + +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) + 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; + } + + /* 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; + } + } + + ao_info->ao_required = cmd.ao_required; + if (new_current) + WRITE_ONCE(ao_info->current_key, new_current); + if (new_rnext) + WRITE_ONCE(ao_info->rnext_key, new_rnext); + if (first) { + 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); +} + diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 7d81e90b6f5c..a4746c27f38a 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2271,11 +2271,16 @@ const struct inet_connection_sock_af_ops ipv4_specific = { }; EXPORT_SYMBOL(ipv4_specific); -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { +#ifdef CONFIG_TCP_MD5SIG .md5_lookup = tcp_v4_md5_lookup, .calc_md5_hash = tcp_v4_md5_hash_skb, .md5_parse = tcp_v4_parse_md5_keys, +#endif +#ifdef CONFIG_TCP_AO + .ao_parse = tcp_v4_parse_ao, +#endif }; #endif @@ -2290,7 +2295,7 @@ static int tcp_v4_init_sock(struct sock *sk) icsk->icsk_af_ops = &ipv4_specific; -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific; #endif @@ -2341,6 +2346,7 @@ void tcp_v4_destroy_sock(struct sock *sk) rcu_assign_pointer(tp->md5sig_info, NULL); } #endif + tcp_ao_destroy_sock(sk); /* Clean up a referenced TCP bind bucket. */ if (inet_csk(sk)->icsk_bind_hash) diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile index 3036a45e8a1e..d283c59df4c1 100644 --- a/net/ipv6/Makefile +++ b/net/ipv6/Makefile @@ -52,4 +52,5 @@ obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_hashtables.o ifneq ($(CONFIG_IPV6),) obj-$(CONFIG_NET_UDP_TUNNEL) += ip6_udp_tunnel.o obj-y += mcast_snoop.o +obj-$(CONFIG_TCP_AO) += tcp_ao.o endif diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c new file mode 100644 index 000000000000..049ddbabe049 --- /dev/null +++ b/net/ipv6/tcp_ao.c @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP Authentication Option (TCP-AO). + * See RFC5925. + * + * Authors: Dmitry Safonov <dima@arista.com> + * Francesco Ruggeri <fruggeri@arista.com> + * Salam Noureddine <noureddine@arista.com> + */ +#include <linux/tcp.h> + +#include <net/tcp.h> +#include <net/ipv6.h> + +int tcp_v6_parse_ao(struct sock *sk, int cmd, + sockptr_t optval, int optlen) +{ + return tcp_parse_ao(sk, cmd, AF_INET6, optval, optlen); +} diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index ee53dad20a59..30bd17d03239 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -76,16 +76,9 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb); static const struct inet_connection_sock_af_ops ipv6_mapped; const struct inet_connection_sock_af_ops ipv6_specific; -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) static const struct tcp_sock_af_ops tcp_sock_ipv6_specific; static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific; -#else -static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, - const struct in6_addr *addr, - int l3index) -{ - return NULL; -} #endif /* Helper returning the inet6 address from a given tcp socket. @@ -239,7 +232,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, if (sk_is_mptcp(sk)) mptcpv6_handle_mapped(sk, true); sk->sk_backlog_rcv = tcp_v4_do_rcv; -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) tp->af_specific = &tcp_sock_ipv6_mapped_specific; #endif @@ -252,7 +245,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, if (sk_is_mptcp(sk)) mptcpv6_handle_mapped(sk, false); sk->sk_backlog_rcv = tcp_v6_do_rcv; -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) tp->af_specific = &tcp_sock_ipv6_specific; #endif goto failure; @@ -769,7 +762,13 @@ clear_hash_nostart: memset(md5_hash, 0, 16); return 1; } - +#else /* CONFIG_TCP_MD5SIG */ +static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, + const struct in6_addr *addr, + int l3index) +{ + return NULL; +} #endif static void tcp_v6_init_req(struct request_sock *req, @@ -1228,7 +1227,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * if (sk_is_mptcp(newsk)) mptcpv6_handle_mapped(newsk, true); newsk->sk_backlog_rcv = tcp_v4_do_rcv; -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) newtp->af_specific = &tcp_sock_ipv6_mapped_specific; #endif @@ -1896,11 +1895,16 @@ const struct inet_connection_sock_af_ops ipv6_specific = { .mtu_reduced = tcp_v6_mtu_reduced, }; -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { +#ifdef CONFIG_TCP_MD5SIG .md5_lookup = tcp_v6_md5_lookup, .calc_md5_hash = tcp_v6_md5_hash_skb, .md5_parse = tcp_v6_parse_md5_keys, +#endif +#ifdef CONFIG_TCP_AO + .ao_parse = tcp_v6_parse_ao, +#endif }; #endif @@ -1922,11 +1926,16 @@ static const struct inet_connection_sock_af_ops ipv6_mapped = { .mtu_reduced = tcp_v4_mtu_reduced, }; -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { +#ifdef CONFIG_TCP_MD5SIG .md5_lookup = tcp_v4_md5_lookup, .calc_md5_hash = tcp_v4_md5_hash_skb, .md5_parse = tcp_v6_parse_md5_keys, +#endif +#ifdef CONFIG_TCP_AO + .ao_parse = tcp_v6_parse_ao, +#endif }; #endif @@ -1941,7 +1950,7 @@ static int tcp_v6_init_sock(struct sock *sk) icsk->icsk_af_ops = &ipv6_specific; -#ifdef CONFIG_TCP_MD5SIG +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific; #endif |