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-rw-r--r--net/mptcp/options.c67
-rw-r--r--net/mptcp/pm_netlink.c12
-rw-r--r--net/mptcp/protocol.c12
-rw-r--r--net/mptcp/protocol.h14
-rw-r--r--net/mptcp/subflow.c30
5 files changed, 122 insertions, 13 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 68361d28dc67..4b7119eb2c31 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -305,6 +305,18 @@ static void mptcp_parse_option(const struct sk_buff *skb,
mp_opt->fastclose = 1;
break;
+ case MPTCPOPT_RST:
+ if (opsize != TCPOLEN_MPTCP_RST)
+ break;
+
+ if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST))
+ break;
+ mp_opt->reset = 1;
+ flags = *ptr++;
+ mp_opt->reset_transient = flags & MPTCP_RST_TRANSIENT;
+ mp_opt->reset_reason = *ptr;
+ break;
+
default:
break;
}
@@ -327,6 +339,7 @@ void mptcp_get_options(const struct sk_buff *skb,
mp_opt->rm_addr = 0;
mp_opt->dss = 0;
mp_opt->mp_prio = 0;
+ mp_opt->reset = 0;
length = (th->doff * 4) - sizeof(struct tcphdr);
ptr = (const unsigned char *)(th + 1);
@@ -726,6 +739,22 @@ static bool mptcp_established_options_mp_prio(struct sock *sk,
return true;
}
+static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb,
+ unsigned int *size,
+ unsigned int remaining,
+ struct mptcp_out_options *opts)
+{
+ const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+
+ if (remaining < TCPOLEN_MPTCP_RST)
+ return;
+
+ *size = TCPOLEN_MPTCP_RST;
+ opts->suboptions |= OPTION_MPTCP_RST;
+ opts->reset_transient = subflow->reset_transient;
+ opts->reset_reason = subflow->reset_reason;
+}
+
bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
unsigned int *size, unsigned int remaining,
struct mptcp_out_options *opts)
@@ -741,11 +770,10 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
if (unlikely(__mptcp_check_fallback(msk)))
return false;
- /* prevent adding of any MPTCP related options on reset packet
- * until we support MP_TCPRST/MP_FASTCLOSE
- */
- if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST))
- return false;
+ if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) {
+ mptcp_established_options_rst(sk, skb, size, remaining, opts);
+ return true;
+ }
snd_data_fin = mptcp_data_fin_enabled(msk);
if (mptcp_established_options_mp(sk, skb, snd_data_fin, &opt_size, remaining, opts))
@@ -1062,6 +1090,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
mp_opt.mp_prio = 0;
}
+ if (mp_opt.reset) {
+ subflow->reset_seen = 1;
+ subflow->reset_reason = mp_opt.reset_reason;
+ subflow->reset_transient = mp_opt.reset_transient;
+ }
+
if (!mp_opt.dss)
return;
@@ -1289,6 +1323,12 @@ mp_capable_done:
ptr += 5;
}
+ if (OPTION_MPTCP_RST & opts->suboptions)
+ *ptr++ = mptcp_option(MPTCPOPT_RST,
+ TCPOLEN_MPTCP_RST,
+ opts->reset_transient,
+ opts->reset_reason);
+
if (opts->ext_copy.use_ack || opts->ext_copy.use_map) {
struct mptcp_ext *mpext = &opts->ext_copy;
u8 len = TCPOLEN_MPTCP_DSS_BASE;
@@ -1340,3 +1380,20 @@ mp_capable_done:
if (tp)
mptcp_set_rwin(tp);
}
+
+__be32 mptcp_get_reset_option(const struct sk_buff *skb)
+{
+ const struct mptcp_ext *ext = mptcp_get_ext(skb);
+ u8 flags, reason;
+
+ if (ext) {
+ flags = ext->reset_transient;
+ reason = ext->reset_reason;
+
+ return mptcp_option(MPTCPOPT_RST, TCPOLEN_MPTCP_RST,
+ flags, reason);
+ }
+
+ return htonl(0u);
+}
+EXPORT_SYMBOL_GPL(mptcp_get_reset_option);
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index cadafafa1049..51be6c34b339 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1687,9 +1687,21 @@ static int mptcp_event_sub_closed(struct sk_buff *skb,
const struct mptcp_sock *msk,
const struct sock *ssk)
{
+ const struct mptcp_subflow_context *sf;
+
if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
return -EMSGSIZE;
+ sf = mptcp_subflow_ctx(ssk);
+ if (!sf->reset_seen)
+ return 0;
+
+ if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
+ return -EMSGSIZE;
+
+ if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
+ return -EMSGSIZE;
+
return 0;
}
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 531ee24aa827..e894345d10c1 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3090,14 +3090,18 @@ bool mptcp_finish_join(struct sock *ssk)
pr_debug("msk=%p, subflow=%p", msk, subflow);
/* mptcp socket already closing? */
- if (!mptcp_is_fully_established(parent))
+ if (!mptcp_is_fully_established(parent)) {
+ subflow->reset_reason = MPTCP_RST_EMPTCP;
return false;
+ }
if (!msk->pm.server_side)
goto out;
- if (!mptcp_pm_allow_new_subflow(msk))
+ if (!mptcp_pm_allow_new_subflow(msk)) {
+ subflow->reset_reason = MPTCP_RST_EPROHIBIT;
return false;
+ }
/* active connections are already on conn_list, and we can't acquire
* msk lock here.
@@ -3111,8 +3115,10 @@ bool mptcp_finish_join(struct sock *ssk)
sock_hold(ssk);
}
spin_unlock_bh(&msk->join_list_lock);
- if (!ret)
+ if (!ret) {
+ subflow->reset_reason = MPTCP_RST_EPROHIBIT;
return false;
+ }
/* attach to msk socket only after we are sure he will deal with us
* at close time
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index e8c5ff2b8ace..40e9b05856cd 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -26,6 +26,7 @@
#define OPTION_MPTCP_RM_ADDR BIT(8)
#define OPTION_MPTCP_FASTCLOSE BIT(9)
#define OPTION_MPTCP_PRIO BIT(10)
+#define OPTION_MPTCP_RST BIT(11)
/* MPTCP option subtypes */
#define MPTCPOPT_MP_CAPABLE 0
@@ -36,6 +37,7 @@
#define MPTCPOPT_MP_PRIO 5
#define MPTCPOPT_MP_FAIL 6
#define MPTCPOPT_MP_FASTCLOSE 7
+#define MPTCPOPT_RST 8
/* MPTCP suboption lengths */
#define TCPOLEN_MPTCP_MPC_SYN 4
@@ -65,6 +67,7 @@
#define TCPOLEN_MPTCP_PRIO 3
#define TCPOLEN_MPTCP_PRIO_ALIGN 4
#define TCPOLEN_MPTCP_FASTCLOSE 12
+#define TCPOLEN_MPTCP_RST 4
/* MPTCP MP_JOIN flags */
#define MPTCPOPT_BACKUP BIT(0)
@@ -94,6 +97,9 @@
/* MPTCP MP_PRIO flags */
#define MPTCP_PRIO_BKUP BIT(0)
+/* MPTCP TCPRST flags */
+#define MPTCP_RST_TRANSIENT BIT(0)
+
/* MPTCP socket flags */
#define MPTCP_DATA_READY 0
#define MPTCP_NOSPACE 1
@@ -123,6 +129,7 @@ struct mptcp_options_received {
u16 mp_capable : 1,
mp_join : 1,
fastclose : 1,
+ reset : 1,
dss : 1,
add_addr : 1,
rm_addr : 1,
@@ -152,6 +159,8 @@ struct mptcp_options_received {
};
u64 ahmac;
u16 port;
+ u8 reset_reason:4;
+ u8 reset_transient:1;
};
static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
@@ -422,6 +431,9 @@ struct mptcp_subflow_context {
u8 hmac[MPTCPOPT_HMAC_LEN];
u8 local_id;
u8 remote_id;
+ u8 reset_seen:1;
+ u8 reset_transient:1;
+ u8 reset_reason:4;
long delegated_status;
struct list_head delegated_node; /* link into delegated_action, protected by local BH */
@@ -742,7 +754,7 @@ unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk);
unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk);
unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk);
-static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
+static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
{
return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
}
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 7a5f50d00d4b..223d6be5fc3b 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -115,6 +115,16 @@ static bool subflow_use_different_sport(struct mptcp_sock *msk, const struct soc
return inet_sk(sk)->inet_sport != inet_sk((struct sock *)msk)->inet_sport;
}
+static void subflow_add_reset_reason(struct sk_buff *skb, u8 reason)
+{
+ struct mptcp_ext *mpext = skb_ext_add(skb, SKB_EXT_MPTCP);
+
+ if (mpext) {
+ memset(mpext, 0, sizeof(*mpext));
+ mpext->reset_reason = reason;
+ }
+}
+
/* Init mptcp request socket.
*
* Returns an error code if a JOIN has failed and a TCP reset
@@ -190,8 +200,10 @@ again:
subflow_req->msk = subflow_token_join_request(req);
/* Can't fall back to TCP in this case. */
- if (!subflow_req->msk)
+ if (!subflow_req->msk) {
+ subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP);
return -EPERM;
+ }
if (subflow_use_different_sport(subflow_req->msk, sk_listener)) {
pr_debug("syn inet_sport=%d %d",
@@ -400,8 +412,10 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
} else if (subflow->request_join) {
u8 hmac[SHA256_DIGEST_SIZE];
- if (!mp_opt.mp_join)
+ if (!mp_opt.mp_join) {
+ subflow->reset_reason = MPTCP_RST_EMPTCP;
goto do_reset;
+ }
subflow->thmac = mp_opt.thmac;
subflow->remote_nonce = mp_opt.nonce;
@@ -410,6 +424,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
if (!subflow_thmac_valid(subflow)) {
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC);
+ subflow->reset_reason = MPTCP_RST_EMPTCP;
goto do_reset;
}
@@ -438,6 +453,7 @@ fallback:
return;
do_reset:
+ subflow->reset_transient = 0;
mptcp_subflow_reset(sk);
}
@@ -654,8 +670,10 @@ create_child:
* to reset the context to non MPTCP status.
*/
if (!ctx || fallback) {
- if (fallback_is_fatal)
+ if (fallback_is_fatal) {
+ subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP);
goto dispose_child;
+ }
subflow_drop_ctx(child);
goto out;
@@ -690,8 +708,10 @@ create_child:
struct mptcp_sock *owner;
owner = subflow_req->msk;
- if (!owner)
+ if (!owner) {
+ subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT);
goto dispose_child;
+ }
/* move the msk reference ownership to the subflow */
subflow_req->msk = NULL;
@@ -1056,6 +1076,8 @@ fatal:
smp_wmb();
ssk->sk_error_report(ssk);
tcp_set_state(ssk, TCP_CLOSE);
+ subflow->reset_transient = 0;
+ subflow->reset_reason = MPTCP_RST_EMPTCP;
tcp_send_active_reset(ssk, GFP_ATOMIC);
subflow->data_avail = 0;
return false;
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-31 10:41:24 +0000