@@ -186,6 +186,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
#define TCPOPT_SACK 5 /* SACK Block */
#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
#define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
+#define TCPOPT_AO 29 /* Authentication Option (RFC5925) */
#define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */
#define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */
#define TCPOPT_EXP 254 /* Experimental */
@@ -2147,6 +2148,12 @@ struct tcp_sock_af_ops {
struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
+ int (*calc_ao_hash)(char *location,
+ struct tcp_ao_key *ao,
+ const struct sock *sk,
+ const struct sk_buff *skb,
+ const u8 *tkey,
+ int hash_offset, u32 sne);
int (*ao_calc_key_sk)(struct tcp_ao_key *mkt,
u8 *key,
const struct sock *sk,
@@ -111,6 +111,10 @@ struct tcp6_ao_context {
};
struct tcp_sigpool;
+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);
int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
@@ -126,13 +130,22 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk,
__be32 sisn, __be32 disn, bool send);
+int tcp_v4_ao_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);
/* ipv6 specific functions */
+int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
+ const struct in6_addr *daddr,
+ const struct in6_addr *saddr, int nbytes);
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send);
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
+int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
+ const struct sock *sk, const struct sk_buff *skb,
+ const u8 *tkey, int hash_offset, u32 sne);
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen);
void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb);
@@ -264,6 +264,171 @@ static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
return -EOPNOTSUPP;
}
+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;
+}
+
+/* tcp_ao_hash_sne(struct tcp_sigpool *hp)
+ * @hp - used for hashing
+ * @sne - sne value
+ */
+static int tcp_ao_hash_sne(struct tcp_sigpool *hp, u32 sne)
+{
+ struct scatterlist sg;
+ __be32 *bp;
+
+ bp = (__be32 *)hp->scratch;
+ *bp = htonl(sne);
+
+ sg_init_one(&sg, bp, sizeof(*bp));
+ ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
+ return crypto_ahash_update(hp->req);
+}
+
+static int tcp_ao_hash_header(struct tcp_sigpool *hp,
+ const struct tcphdr *th,
+ bool exclude_options, u8 *hash,
+ int hash_offset, int hash_len)
+{
+ struct scatterlist sg;
+ u8 *hdr = hp->scratch;
+ int err, len = th->doff << 2;
+
+ /* 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_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, false,
+ 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);
+}
+
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
@@ -2285,6 +2285,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
#endif
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v4_ao_lookup,
+ .calc_ao_hash = tcp_v4_ao_hash_skb,
.ao_parse = tcp_v4_parse_ao,
.ao_calc_key_sk = tcp_v4_ao_calc_key_sk,
#endif
@@ -415,6 +415,7 @@ static inline bool tcp_urg_mode(const struct tcp_sock *tp)
#define OPTION_FAST_OPEN_COOKIE BIT(8)
#define OPTION_SMC BIT(9)
#define OPTION_MPTCP BIT(10)
+#define OPTION_AO BIT(11)
static void smc_options_write(__be32 *ptr, u16 *options)
{
@@ -607,7 +608,8 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb,
* (but it may well be that other scenarios fail similarly).
*/
static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
- struct tcp_out_options *opts)
+ struct tcp_out_options *opts,
+ struct tcp_ao_key *ao_key)
{
__be32 *ptr = (__be32 *)(th + 1);
u16 options = opts->options; /* mungable copy */
@@ -619,7 +621,33 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
opts->hash_location = (__u8 *)ptr;
ptr += 4;
}
+#ifdef CONFIG_TCP_AO
+ if (unlikely(OPTION_AO & options) && tp) {
+ struct tcp_ao_key *rnext_key;
+ struct tcp_ao_info *ao_info;
+ u8 maclen;
+ if (WARN_ON_ONCE(!ao_key))
+ goto out_ao;
+ ao_info = rcu_dereference_check(tp->ao_info,
+ lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
+ rnext_key = READ_ONCE(ao_info->rnext_key);
+ if (WARN_ON_ONCE(!rnext_key))
+ goto out_ao;
+ maclen = tcp_ao_maclen(ao_key);
+ *ptr++ = htonl((TCPOPT_AO << 24) |
+ (tcp_ao_len(ao_key) << 16) |
+ (ao_key->sndid << 8) |
+ (rnext_key->rcvid));
+ opts->hash_location = (__u8 *)ptr;
+ ptr += maclen / sizeof(*ptr);
+ if (unlikely(maclen % sizeof(*ptr))) {
+ memset(ptr, TCPOPT_NOP, sizeof(*ptr));
+ ptr++;
+ }
+ }
+out_ao:
+#endif
if (unlikely(opts->mss)) {
*ptr++ = htonl((TCPOPT_MSS << 24) |
(TCPOLEN_MSS << 16) |
@@ -760,7 +788,8 @@ static void mptcp_set_option_cond(const struct request_sock *req,
*/
static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
struct tcp_out_options *opts,
- struct tcp_md5sig_key **md5)
+ struct tcp_md5sig_key **md5,
+ struct tcp_ao_key *ao_key)
{
struct tcp_sock *tp = tcp_sk(sk);
unsigned int remaining = MAX_TCP_OPTION_SPACE;
@@ -777,6 +806,12 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
}
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao_key) {
+ opts->options |= OPTION_AO;
+ remaining -= tcp_ao_len(ao_key);
+ }
+#endif
/* We always get an MSS option. The option bytes which will be seen in
* normal data packets should timestamps be used, must be in the MSS
@@ -844,6 +879,7 @@ static unsigned int tcp_synack_options(const struct sock *sk,
unsigned int mss, struct sk_buff *skb,
struct tcp_out_options *opts,
const struct tcp_md5sig_key *md5,
+ const struct tcp_ao_key *ao,
struct tcp_fastopen_cookie *foc,
enum tcp_synack_type synack_type,
struct sk_buff *syn_skb)
@@ -865,6 +901,14 @@ static unsigned int tcp_synack_options(const struct sock *sk,
ireq->tstamp_ok &= !ireq->sack_ok;
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao) {
+ opts->options |= OPTION_AO;
+ remaining -= tcp_ao_len(ao);
+ ireq->tstamp_ok &= !ireq->sack_ok;
+ }
+#endif
+ WARN_ON_ONCE(md5 && ao);
/* We always send an MSS option. */
opts->mss = mss;
@@ -914,7 +958,8 @@ static unsigned int tcp_synack_options(const struct sock *sk,
*/
static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb,
struct tcp_out_options *opts,
- struct tcp_md5sig_key **md5)
+ struct tcp_md5sig_key **md5,
+ struct tcp_ao_key *ao_key)
{
struct tcp_sock *tp = tcp_sk(sk);
unsigned int size = 0;
@@ -933,6 +978,12 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
}
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao_key) {
+ opts->options |= OPTION_AO;
+ size += tcp_ao_len(ao_key);
+ }
+#endif
if (likely(tp->rx_opt.tstamp_ok)) {
opts->options |= OPTION_TS;
@@ -1244,6 +1295,10 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
unsigned int tcp_options_size, tcp_header_size;
struct sk_buff *oskb = NULL;
struct tcp_md5sig_key *md5;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao;
+#endif
+ struct tcp_ao_key *ao_key = NULL;
struct tcphdr *th;
u64 prior_wstamp;
int err;
@@ -1275,11 +1330,17 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
tcb = TCP_SKB_CB(skb);
memset(&opts, 0, sizeof(opts));
+#ifdef CONFIG_TCP_AO
+ ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
+ if (ao)
+ ao_key = READ_ONCE(ao->current_key);
+#endif
if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
- tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5);
+ tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5, ao_key);
} else {
tcp_options_size = tcp_established_options(sk, skb, &opts,
- &md5);
+ &md5, ao_key);
/* Force a PSH flag on all (GSO) packets to expedite GRO flush
* at receiver : This slightly improve GRO performance.
* Note that we do not force the PSH flag for non GSO packets,
@@ -1353,7 +1414,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
th->window = htons(min(tp->rcv_wnd, 65535U));
}
- tcp_options_write(th, tp, &opts);
+ tcp_options_write(th, tp, &opts, ao_key);
#ifdef CONFIG_TCP_MD5SIG
/* Calculate the MD5 hash, as we have all we need now */
@@ -1363,6 +1424,34 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
md5, sk, skb);
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao) {
+ u8 *traffic_key;
+ void *tkey_buf = NULL;
+ u32 disn;
+
+ sk_gso_disable(sk);
+ if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
+ if (tcb->tcp_flags & TCPHDR_ACK)
+ disn = ao->risn;
+ else
+ disn = 0;
+
+ tkey_buf = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC);
+ if (!tkey_buf)
+ return -ENOMEM;
+ traffic_key = tkey_buf;
+ tp->af_specific->ao_calc_key_sk(ao_key, traffic_key,
+ sk, ao->lisn, disn, true);
+ } else {
+ traffic_key = snd_other_key(ao_key);
+ }
+ tp->af_specific->calc_ao_hash(opts.hash_location, ao_key, sk, skb,
+ traffic_key,
+ opts.hash_location - (u8 *)th, 0);
+ kfree(tkey_buf);
+ }
+#endif
/* BPF prog is the last one writing header option */
bpf_skops_write_hdr_opt(sk, skb, NULL, NULL, 0, &opts);
@@ -1814,6 +1903,10 @@ unsigned int tcp_current_mss(struct sock *sk)
unsigned int header_len;
struct tcp_out_options opts;
struct tcp_md5sig_key *md5;
+ struct tcp_ao_key *ao_key = NULL;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao_info;
+#endif
mss_now = tp->mss_cache;
@@ -1822,8 +1915,17 @@ unsigned int tcp_current_mss(struct sock *sk)
if (mtu != inet_csk(sk)->icsk_pmtu_cookie)
mss_now = tcp_sync_mss(sk, mtu);
}
-
- header_len = tcp_established_options(sk, NULL, &opts, &md5) +
+#ifdef CONFIG_TCP_AO
+ ao_info = rcu_dereference_check(tp->ao_info, lockdep_sock_is_held(sk));
+ if (ao_info)
+ /* TODO: verify if we can access current_key or we need to pass
+ * it from every caller of tcp_current_mss instead. The reason
+ * is that the current_key pointer can change asynchronously
+ * from the rx path.
+ */
+ ao_key = READ_ONCE(ao_info->current_key);
+#endif
+ header_len = tcp_established_options(sk, NULL, &opts, &md5, ao_key) +
sizeof(struct tcphdr);
/* The mss_cache is sized based on tp->tcp_header_len, which assumes
* some common options. If this is an odd packet (because we have SACK
@@ -3664,7 +3766,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
/* bpf program will be interested in the tcp_flags */
TCP_SKB_CB(skb)->tcp_flags = TCPHDR_SYN | TCPHDR_ACK;
tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5,
- foc, synack_type,
+ NULL, foc, synack_type,
syn_skb) + sizeof(*th);
skb_push(skb, tcp_header_size);
@@ -3685,7 +3787,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
th->window = htons(min(req->rsk_rcv_wnd, 65535U));
- tcp_options_write(th, NULL, &opts);
+ tcp_options_write(th, NULL, &opts, NULL);
th->doff = (tcp_header_size >> 2);
TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
@@ -7,6 +7,7 @@
* Francesco Ruggeri <fruggeri@arista.com>
* Salam Noureddine <noureddine@arista.com>
*/
+#include <crypto/hash.h>
#include <linux/tcp.h>
#include <net/tcp.h>
@@ -79,6 +80,33 @@ struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
}
+int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
+ const struct in6_addr *daddr,
+ const struct in6_addr *saddr, int nbytes)
+{
+ struct tcp6_pseudohdr *bp;
+ struct scatterlist sg;
+
+ bp = hp->scratch;
+ /* 1. TCP pseudo-header (RFC2460) */
+ bp->saddr = *saddr;
+ bp->daddr = *daddr;
+ bp->len = cpu_to_be32(nbytes);
+ bp->protocol = cpu_to_be32(IPPROTO_TCP);
+
+ sg_init_one(&sg, bp, sizeof(*bp));
+ ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
+ return crypto_ahash_update(hp->req);
+}
+
+int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
+ const struct sock *sk, const struct sk_buff *skb,
+ const u8 *tkey, int hash_offset, u32 sne)
+{
+ return tcp_ao_hash_skb(AF_INET6, ao_hash, key, sk, skb, tkey,
+ hash_offset, sne);
+}
+
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen)
{
@@ -1916,6 +1916,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
#endif
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v6_ao_lookup,
+ .calc_ao_hash = tcp_v6_ao_hash_skb,
.ao_parse = tcp_v6_parse_ao,
.ao_calc_key_sk = tcp_v6_ao_calc_key_sk,
#endif
@@ -1949,6 +1950,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
#endif
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v6_ao_lookup,
+ .calc_ao_hash = tcp_v4_ao_hash_skb,
.ao_parse = tcp_v6_parse_ao,
#endif
};