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-rw-r--r--net/mptcp/options.c95
-rw-r--r--net/mptcp/protocol.c17
-rw-r--r--net/mptcp/protocol.h43
-rw-r--r--net/mptcp/subflow.c86
4 files changed, 146 insertions, 95 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 4a7c467b99db..45497af23906 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -16,10 +16,10 @@ static bool mptcp_cap_flag_sha256(u8 flags)
return (flags & MPTCP_CAP_FLAG_MASK) == MPTCP_CAP_HMAC_SHA256;
}
-void mptcp_parse_option(const struct sk_buff *skb, const unsigned char *ptr,
- int opsize, struct tcp_options_received *opt_rx)
+static void mptcp_parse_option(const struct sk_buff *skb,
+ const unsigned char *ptr, int opsize,
+ struct mptcp_options_received *mp_opt)
{
- struct mptcp_options_received *mp_opt = &opt_rx->mptcp;
u8 subtype = *ptr >> 4;
int expected_opsize;
u8 version;
@@ -283,12 +283,20 @@ void mptcp_parse_option(const struct sk_buff *skb, const unsigned char *ptr,
}
void mptcp_get_options(const struct sk_buff *skb,
- struct tcp_options_received *opt_rx)
+ struct mptcp_options_received *mp_opt)
{
- const unsigned char *ptr;
const struct tcphdr *th = tcp_hdr(skb);
- int length = (th->doff * 4) - sizeof(struct tcphdr);
+ const unsigned char *ptr;
+ int length;
+
+ /* initialize option status */
+ mp_opt->mp_capable = 0;
+ mp_opt->mp_join = 0;
+ mp_opt->add_addr = 0;
+ mp_opt->rm_addr = 0;
+ mp_opt->dss = 0;
+ length = (th->doff * 4) - sizeof(struct tcphdr);
ptr = (const unsigned char *)(th + 1);
while (length > 0) {
@@ -308,7 +316,7 @@ void mptcp_get_options(const struct sk_buff *skb,
if (opsize > length)
return; /* don't parse partial options */
if (opcode == TCPOPT_MPTCP)
- mptcp_parse_option(skb, ptr, opsize, opt_rx);
+ mptcp_parse_option(skb, ptr, opsize, mp_opt);
ptr += opsize - 2;
length -= opsize;
}
@@ -344,28 +352,6 @@ bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
return false;
}
-void mptcp_rcv_synsent(struct sock *sk)
-{
- struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
- struct tcp_sock *tp = tcp_sk(sk);
-
- if (subflow->request_mptcp && tp->rx_opt.mptcp.mp_capable) {
- subflow->mp_capable = 1;
- subflow->can_ack = 1;
- subflow->remote_key = tp->rx_opt.mptcp.sndr_key;
- pr_debug("subflow=%p, remote_key=%llu", subflow,
- subflow->remote_key);
- } else if (subflow->request_join && tp->rx_opt.mptcp.mp_join) {
- subflow->mp_join = 1;
- subflow->thmac = tp->rx_opt.mptcp.thmac;
- subflow->remote_nonce = tp->rx_opt.mptcp.nonce;
- pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow,
- subflow->thmac, subflow->remote_nonce);
- } else if (subflow->request_mptcp) {
- tcp_sk(sk)->is_mptcp = 0;
- }
-}
-
/* MP_JOIN client subflow must wait for 4th ack before sending any data:
* TCP can't schedule delack timer before the subflow is fully established.
* MPTCP uses the delack timer to do 3rd ack retransmissions
@@ -709,7 +695,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *sk,
if (TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1)
return subflow->mp_capable;
- if (mp_opt->use_ack) {
+ if (mp_opt->dss && mp_opt->use_ack) {
/* subflows are fully established as soon as we get any
* additional ack.
*/
@@ -717,8 +703,6 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *sk,
goto fully_established;
}
- WARN_ON_ONCE(subflow->can_ack);
-
/* If the first established packet does not contain MP_CAPABLE + data
* then fallback to TCP
*/
@@ -728,6 +712,8 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *sk,
return false;
}
+ if (unlikely(!READ_ONCE(msk->pm.server_side)))
+ pr_warn_once("bogus mpc option on established client sk");
subflow->fully_established = 1;
subflow->remote_key = mp_opt->sndr_key;
subflow->can_ack = 1;
@@ -819,41 +805,41 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb,
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
struct mptcp_sock *msk = mptcp_sk(subflow->conn);
- struct mptcp_options_received *mp_opt;
+ struct mptcp_options_received mp_opt;
struct mptcp_ext *mpext;
- mp_opt = &opt_rx->mptcp;
- if (!check_fully_established(msk, sk, subflow, skb, mp_opt))
+ mptcp_get_options(skb, &mp_opt);
+ if (!check_fully_established(msk, sk, subflow, skb, &mp_opt))
return;
- if (mp_opt->add_addr && add_addr_hmac_valid(msk, mp_opt)) {
+ if (mp_opt.add_addr && add_addr_hmac_valid(msk, &mp_opt)) {
struct mptcp_addr_info addr;
- addr.port = htons(mp_opt->port);
- addr.id = mp_opt->addr_id;
- if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) {
+ addr.port = htons(mp_opt.port);
+ addr.id = mp_opt.addr_id;
+ if (mp_opt.family == MPTCP_ADDR_IPVERSION_4) {
addr.family = AF_INET;
- addr.addr = mp_opt->addr;
+ addr.addr = mp_opt.addr;
}
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
- else if (mp_opt->family == MPTCP_ADDR_IPVERSION_6) {
+ else if (mp_opt.family == MPTCP_ADDR_IPVERSION_6) {
addr.family = AF_INET6;
- addr.addr6 = mp_opt->addr6;
+ addr.addr6 = mp_opt.addr6;
}
#endif
- if (!mp_opt->echo)
+ if (!mp_opt.echo)
mptcp_pm_add_addr_received(msk, &addr);
- mp_opt->add_addr = 0;
+ mp_opt.add_addr = 0;
}
- if (!mp_opt->dss)
+ if (!mp_opt.dss)
return;
/* we can't wait for recvmsg() to update the ack_seq, otherwise
* monodirectional flows will stuck
*/
- if (mp_opt->use_ack)
- update_una(msk, mp_opt);
+ if (mp_opt.use_ack)
+ update_una(msk, &mp_opt);
mpext = skb_ext_add(skb, SKB_EXT_MPTCP);
if (!mpext)
@@ -861,8 +847,8 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb,
memset(mpext, 0, sizeof(*mpext));
- if (mp_opt->use_map) {
- if (mp_opt->mpc_map) {
+ if (mp_opt.use_map) {
+ if (mp_opt.mpc_map) {
/* this is an MP_CAPABLE carrying MPTCP data
* we know this map the first chunk of data
*/
@@ -872,13 +858,14 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb,
mpext->subflow_seq = 1;
mpext->dsn64 = 1;
mpext->mpc_map = 1;
+ mpext->data_fin = 0;
} else {
- mpext->data_seq = mp_opt->data_seq;
- mpext->subflow_seq = mp_opt->subflow_seq;
- mpext->dsn64 = mp_opt->dsn64;
- mpext->data_fin = mp_opt->data_fin;
+ mpext->data_seq = mp_opt.data_seq;
+ mpext->subflow_seq = mp_opt.subflow_seq;
+ mpext->dsn64 = mp_opt.dsn64;
+ mpext->data_fin = mp_opt.data_fin;
}
- mpext->data_len = mp_opt->data_len;
+ mpext->data_len = mp_opt.data_len;
mpext->use_map = 1;
}
}
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b22a63ba2348..e1f23016ed3f 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1316,11 +1316,12 @@ static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)
static int mptcp_disconnect(struct sock *sk, int flags)
{
- lock_sock(sk);
- __mptcp_clear_xmit(sk);
- release_sock(sk);
- mptcp_cancel_work(sk);
- return tcp_disconnect(sk, flags);
+ /* Should never be called.
+ * inet_stream_connect() calls ->disconnect, but that
+ * refers to the subflow socket, not the mptcp one.
+ */
+ WARN_ON_ONCE(1);
+ return 0;
}
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
@@ -1333,7 +1334,7 @@ static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk)
#endif
struct sock *mptcp_sk_clone(const struct sock *sk,
- const struct tcp_options_received *opt_rx,
+ const struct mptcp_options_received *mp_opt,
struct request_sock *req)
{
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
@@ -1372,9 +1373,9 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
msk->write_seq = subflow_req->idsn + 1;
atomic64_set(&msk->snd_una, msk->write_seq);
- if (opt_rx->mptcp.mp_capable) {
+ if (mp_opt->mp_capable) {
msk->can_ack = true;
- msk->remote_key = opt_rx->mptcp.sndr_key;
+ msk->remote_key = mp_opt->sndr_key;
mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq);
ack_seq++;
msk->ack_seq = ack_seq;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index a2b3048037d0..e4ca6320ce76 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -91,6 +91,45 @@
#define MPTCP_WORK_RTX 2
#define MPTCP_WORK_EOF 3
+struct mptcp_options_received {
+ u64 sndr_key;
+ u64 rcvr_key;
+ u64 data_ack;
+ u64 data_seq;
+ u32 subflow_seq;
+ u16 data_len;
+ u16 mp_capable : 1,
+ mp_join : 1,
+ dss : 1,
+ add_addr : 1,
+ rm_addr : 1,
+ family : 4,
+ echo : 1,
+ backup : 1;
+ u32 token;
+ u32 nonce;
+ u64 thmac;
+ u8 hmac[20];
+ u8 join_id;
+ u8 use_map:1,
+ dsn64:1,
+ data_fin:1,
+ use_ack:1,
+ ack64:1,
+ mpc_map:1,
+ __unused:2;
+ u8 addr_id;
+ u8 rm_id;
+ union {
+ struct in_addr addr;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+ struct in6_addr addr6;
+#endif
+ };
+ u64 ahmac;
+ u16 port;
+};
+
static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
{
return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
@@ -331,10 +370,10 @@ int mptcp_proto_v6_init(void);
#endif
struct sock *mptcp_sk_clone(const struct sock *sk,
- const struct tcp_options_received *opt_rx,
+ const struct mptcp_options_received *mp_opt,
struct request_sock *req);
void mptcp_get_options(const struct sk_buff *skb,
- struct tcp_options_received *opt_rx);
+ struct mptcp_options_received *mp_opt);
void mptcp_finish_connect(struct sock *sk);
void mptcp_data_ready(struct sock *sk, struct sock *ssk);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index fabd06f2ff45..67a4e35d4838 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -124,12 +124,11 @@ static void subflow_init_req(struct request_sock *req,
{
struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener);
struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
- struct tcp_options_received rx_opt;
+ struct mptcp_options_received mp_opt;
pr_debug("subflow_req=%p, listener=%p", subflow_req, listener);
- memset(&rx_opt.mptcp, 0, sizeof(rx_opt.mptcp));
- mptcp_get_options(skb, &rx_opt);
+ mptcp_get_options(skb, &mp_opt);
subflow_req->mp_capable = 0;
subflow_req->mp_join = 0;
@@ -142,16 +141,16 @@ static void subflow_init_req(struct request_sock *req,
return;
#endif
- if (rx_opt.mptcp.mp_capable) {
+ if (mp_opt.mp_capable) {
SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE);
- if (rx_opt.mptcp.mp_join)
+ if (mp_opt.mp_join)
return;
- } else if (rx_opt.mptcp.mp_join) {
+ } else if (mp_opt.mp_join) {
SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX);
}
- if (rx_opt.mptcp.mp_capable && listener->request_mptcp) {
+ if (mp_opt.mp_capable && listener->request_mptcp) {
int err;
err = mptcp_token_new_request(req);
@@ -159,13 +158,13 @@ static void subflow_init_req(struct request_sock *req,
subflow_req->mp_capable = 1;
subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
- } else if (rx_opt.mptcp.mp_join && listener->request_mptcp) {
+ } else if (mp_opt.mp_join && listener->request_mptcp) {
subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;
subflow_req->mp_join = 1;
- subflow_req->backup = rx_opt.mptcp.backup;
- subflow_req->remote_id = rx_opt.mptcp.join_id;
- subflow_req->token = rx_opt.mptcp.token;
- subflow_req->remote_nonce = rx_opt.mptcp.nonce;
+ subflow_req->backup = mp_opt.backup;
+ subflow_req->remote_id = mp_opt.join_id;
+ subflow_req->token = mp_opt.token;
+ subflow_req->remote_nonce = mp_opt.nonce;
pr_debug("token=%u, remote_nonce=%u", subflow_req->token,
subflow_req->remote_nonce);
if (!subflow_token_join_request(req, skb)) {
@@ -221,23 +220,47 @@ static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow)
static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+ struct mptcp_options_received mp_opt;
struct sock *parent = subflow->conn;
+ struct tcp_sock *tp = tcp_sk(sk);
subflow->icsk_af_ops->sk_rx_dst_set(sk, skb);
- if (inet_sk_state_load(parent) != TCP_ESTABLISHED) {
+ if (inet_sk_state_load(parent) == TCP_SYN_SENT) {
inet_sk_state_store(parent, TCP_ESTABLISHED);
parent->sk_state_change(parent);
}
- if (subflow->conn_finished || !tcp_sk(sk)->is_mptcp)
+ /* be sure no special action on any packet other than syn-ack */
+ if (subflow->conn_finished)
+ return;
+
+ subflow->conn_finished = 1;
+
+ mptcp_get_options(skb, &mp_opt);
+ if (subflow->request_mptcp && mp_opt.mp_capable) {
+ subflow->mp_capable = 1;
+ subflow->can_ack = 1;
+ subflow->remote_key = mp_opt.sndr_key;
+ pr_debug("subflow=%p, remote_key=%llu", subflow,
+ subflow->remote_key);
+ } else if (subflow->request_join && mp_opt.mp_join) {
+ subflow->mp_join = 1;
+ subflow->thmac = mp_opt.thmac;
+ subflow->remote_nonce = mp_opt.nonce;
+ pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow,
+ subflow->thmac, subflow->remote_nonce);
+ } else if (subflow->request_mptcp) {
+ tp->is_mptcp = 0;
+ }
+
+ if (!tp->is_mptcp)
return;
if (subflow->mp_capable) {
pr_debug("subflow=%p, remote_key=%llu", mptcp_subflow_ctx(sk),
subflow->remote_key);
mptcp_finish_connect(sk);
- subflow->conn_finished = 1;
if (skb) {
pr_debug("synack seq=%u", TCP_SKB_CB(skb)->seq);
@@ -264,7 +287,6 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
if (!mptcp_finish_join(sk))
goto do_reset;
- subflow->conn_finished = 1;
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX);
} else {
do_reset:
@@ -322,7 +344,7 @@ drop:
/* validate hmac received in third ACK */
static bool subflow_hmac_valid(const struct request_sock *req,
- const struct tcp_options_received *rx_opt)
+ const struct mptcp_options_received *mp_opt)
{
const struct mptcp_subflow_request_sock *subflow_req;
u8 hmac[MPTCPOPT_HMAC_LEN];
@@ -339,7 +361,7 @@ static bool subflow_hmac_valid(const struct request_sock *req,
subflow_req->local_nonce, hmac);
ret = true;
- if (crypto_memneq(hmac, rx_opt->mptcp.hmac, sizeof(hmac)))
+ if (crypto_memneq(hmac, mp_opt->hmac, sizeof(hmac)))
ret = false;
sock_put((struct sock *)msk);
@@ -395,7 +417,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
{
struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk);
struct mptcp_subflow_request_sock *subflow_req;
- struct tcp_options_received opt_rx;
+ struct mptcp_options_received mp_opt;
bool fallback_is_fatal = false;
struct sock *new_msk = NULL;
bool fallback = false;
@@ -403,7 +425,10 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn);
- opt_rx.mptcp.mp_capable = 0;
+ /* we need later a valid 'mp_capable' value even when options are not
+ * parsed
+ */
+ mp_opt.mp_capable = 0;
if (tcp_rsk(req)->is_mptcp == 0)
goto create_child;
@@ -418,22 +443,21 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
goto create_msk;
}
- mptcp_get_options(skb, &opt_rx);
- if (!opt_rx.mptcp.mp_capable) {
+ mptcp_get_options(skb, &mp_opt);
+ if (!mp_opt.mp_capable) {
fallback = true;
goto create_child;
}
create_msk:
- new_msk = mptcp_sk_clone(listener->conn, &opt_rx, req);
+ new_msk = mptcp_sk_clone(listener->conn, &mp_opt, req);
if (!new_msk)
fallback = true;
} else if (subflow_req->mp_join) {
fallback_is_fatal = true;
- opt_rx.mptcp.mp_join = 0;
- mptcp_get_options(skb, &opt_rx);
- if (!opt_rx.mptcp.mp_join ||
- !subflow_hmac_valid(req, &opt_rx)) {
+ mptcp_get_options(skb, &mp_opt);
+ if (!mp_opt.mp_join ||
+ !subflow_hmac_valid(req, &mp_opt)) {
SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC);
return NULL;
}
@@ -473,9 +497,9 @@ create_child:
/* with OoO packets we can reach here without ingress
* mpc option
*/
- ctx->remote_key = opt_rx.mptcp.sndr_key;
- ctx->fully_established = opt_rx.mptcp.mp_capable;
- ctx->can_ack = opt_rx.mptcp.mp_capable;
+ ctx->remote_key = mp_opt.sndr_key;
+ ctx->fully_established = mp_opt.mp_capable;
+ ctx->can_ack = mp_opt.mp_capable;
} else if (ctx->mp_join) {
struct mptcp_sock *owner;
@@ -499,7 +523,7 @@ out:
/* check for expected invariant - should never trigger, just help
* catching eariler subtle bugs
*/
- WARN_ON_ONCE(*own_req && child && tcp_sk(child)->is_mptcp &&
+ WARN_ON_ONCE(child && *own_req && tcp_sk(child)->is_mptcp &&
(!mptcp_subflow_ctx(child) ||
!mptcp_subflow_ctx(child)->conn));
return child;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.