| Message ID | 34c617cdc777aa32b1fa4ecc5c23784255f5fa56.1707144963.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Commit | bb35405f2e28c49f77763429a125185f7b6240a3 |
| Delegated to: | Mat Martineau |
| Headers | show |
| Series | mptcp: fix duplicate subflow creation | expand |
| Context | Check | Description |
|---|---|---|
| matttbe/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 98 lines checked |
| matttbe/build | success | Build and static analysis OK |
| matttbe/KVM_Validation__normal | success | Success! ✅ |
| matttbe/KVM_Validation__debug__except_selftest_mptcp_join_ | warning | Unstable: 1 failed test(s): packetdrill_regressions |
| matttbe/KVM_Validation__debug__only_selftest_mptcp_join_ | success | Success! ✅ |
On Mon, 5 Feb 2024, Paolo Abeni wrote: > The local address id is accessed lockless by the NL PM, add > all the required ONCE annotation. There is a caveat: the local > id can be initialized late in the subflow life-cycle, and its > validity is controlled by the local_id_valid flag. > > Remove such flag and encode the validity in the local_id field > itself with negative value before initialization. That allows > accessing the field consistently with a single read operation. > > Fixes: 0ee4261a3681 ("mptcp: implement mptcp_pm_remove_subflow") > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > --- > net/mptcp/pm_netlink.c | 4 ++-- > net/mptcp/protocol.c | 2 +- > net/mptcp/protocol.h | 15 ++++++++++++--- > net/mptcp/subflow.c | 9 +++++---- > 4 files changed, 20 insertions(+), 10 deletions(-) > > diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c > index d9ad45959219..d1b984c9dc25 100644 > --- a/net/mptcp/pm_netlink.c > +++ b/net/mptcp/pm_netlink.c > @@ -800,7 +800,7 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, > mptcp_for_each_subflow_safe(msk, subflow, tmp) { > struct sock *ssk = mptcp_subflow_tcp_sock(subflow); > int how = RCV_SHUTDOWN | SEND_SHUTDOWN; > - u8 id = subflow->local_id; > + u8 id = subflow_get_local_id(subflow); > > if (rm_type == MPTCP_MIB_RMADDR && subflow->remote_id != rm_id) > continue; > @@ -809,7 +809,7 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, > > pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u", > rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", > - i, rm_id, subflow->local_id, subflow->remote_id, > + i, rm_id, id, subflow->remote_id, > msk->mpc_endpoint_id); > spin_unlock_bh(&msk->pm.lock); > mptcp_subflow_shutdown(sk, ssk, how); > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index a8a94b34a51e..626fb4907381 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -85,7 +85,7 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) > subflow->subflow_id = msk->subflow_id++; > > /* This is the first subflow, always with id 0 */ > - subflow->local_id_valid = 1; > + WRITE_ONCE(subflow->local_id, 0); > mptcp_sock_graft(msk->first, sk->sk_socket); > iput(SOCK_INODE(ssock)); > > diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h > index de04b97e8dd1..9813de82bab8 100644 > --- a/net/mptcp/protocol.h > +++ b/net/mptcp/protocol.h > @@ -493,10 +493,9 @@ struct mptcp_subflow_context { > remote_key_valid : 1, /* received the peer key from */ > disposable : 1, /* ctx can be free at ulp release time */ > stale : 1, /* unable to snd/rcv data, do not use for xmit */ > - local_id_valid : 1, /* local_id is correctly initialized */ > valid_csum_seen : 1, /* at least one csum validated */ > is_mptfo : 1, /* subflow is doing TFO */ > - __unused : 9; > + __unused : 10; > bool data_avail; > bool scheduled; > u32 remote_nonce; > @@ -507,7 +506,7 @@ struct mptcp_subflow_context { > u8 hmac[MPTCPOPT_HMAC_LEN]; /* MPJ subflow only */ > u64 iasn; /* initial ack sequence number, MPC subflows only */ > }; > - u8 local_id; > + s16 local_id; /* if negative not initialized yet */ > u8 remote_id; > u8 reset_seen:1; > u8 reset_transient:1; > @@ -558,6 +557,7 @@ mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow) > { > memset(&subflow->reset, 0, sizeof(subflow->reset)); > subflow->request_mptcp = 1; > + WRITE_ONCE(subflow->local_id, -1); > } > > static inline u64 > @@ -1064,6 +1064,15 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc); > int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc); > int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc); > > +static inline int subflow_get_local_id(struct mptcp_subflow_context *subflow) Hi Paolo - Better to return a u8? > +{ > + int local_id = READ_ONCE(subflow->local_id); > + > + if (local_id < 0) > + return 0; > + return local_id; > +} Looking around at code that still directly reads local_id from subflow contexts: Should this also be used at line 236 in pm_userspace.c? What about the places where local_id is passed in to nla_put_u8? (diag.c:68 and pm_netlink.c:1986?) - Mat > + > void __init mptcp_pm_nl_init(void); > void mptcp_pm_nl_work(struct mptcp_sock *msk); > void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, > diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c > index 02dab0669cfc..068784d3e748 100644 > --- a/net/mptcp/subflow.c > +++ b/net/mptcp/subflow.c > @@ -578,8 +578,8 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) > > static void subflow_set_local_id(struct mptcp_subflow_context *subflow, int local_id) > { > - subflow->local_id = local_id; > - subflow->local_id_valid = 1; > + WARN_ON_ONCE(local_id < 0 || local_id > 255); > + WRITE_ONCE(subflow->local_id, local_id); > } > > static int subflow_chk_local_id(struct sock *sk) > @@ -588,7 +588,7 @@ static int subflow_chk_local_id(struct sock *sk) > struct mptcp_sock *msk = mptcp_sk(subflow->conn); > int err; > > - if (likely(subflow->local_id_valid)) > + if (likely(subflow->local_id >= 0)) > return 0; > > err = mptcp_pm_get_local_id(msk, (struct sock_common *)sk); > @@ -1733,6 +1733,7 @@ static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, > pr_debug("subflow=%p", ctx); > > ctx->tcp_sock = sk; > + WRITE_ONCE(ctx->local_id, -1); > > return ctx; > } > @@ -1968,7 +1969,7 @@ static void subflow_ulp_clone(const struct request_sock *req, > new_ctx->idsn = subflow_req->idsn; > > /* this is the first subflow, id is always 0 */ > - new_ctx->local_id_valid = 1; > + subflow_set_local_id(new_ctx, 0); > } else if (subflow_req->mp_join) { > new_ctx->ssn_offset = subflow_req->ssn_offset; > new_ctx->mp_join = 1; > -- > 2.43.0 > > >
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index d9ad45959219..d1b984c9dc25 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -800,7 +800,7 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, mptcp_for_each_subflow_safe(msk, subflow, tmp) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); int how = RCV_SHUTDOWN | SEND_SHUTDOWN; - u8 id = subflow->local_id; + u8 id = subflow_get_local_id(subflow); if (rm_type == MPTCP_MIB_RMADDR && subflow->remote_id != rm_id) continue; @@ -809,7 +809,7 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u", rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", - i, rm_id, subflow->local_id, subflow->remote_id, + i, rm_id, id, subflow->remote_id, msk->mpc_endpoint_id); spin_unlock_bh(&msk->pm.lock); mptcp_subflow_shutdown(sk, ssk, how); diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index a8a94b34a51e..626fb4907381 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -85,7 +85,7 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) subflow->subflow_id = msk->subflow_id++; /* This is the first subflow, always with id 0 */ - subflow->local_id_valid = 1; + WRITE_ONCE(subflow->local_id, 0); mptcp_sock_graft(msk->first, sk->sk_socket); iput(SOCK_INODE(ssock)); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index de04b97e8dd1..9813de82bab8 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -493,10 +493,9 @@ struct mptcp_subflow_context { remote_key_valid : 1, /* received the peer key from */ disposable : 1, /* ctx can be free at ulp release time */ stale : 1, /* unable to snd/rcv data, do not use for xmit */ - local_id_valid : 1, /* local_id is correctly initialized */ valid_csum_seen : 1, /* at least one csum validated */ is_mptfo : 1, /* subflow is doing TFO */ - __unused : 9; + __unused : 10; bool data_avail; bool scheduled; u32 remote_nonce; @@ -507,7 +506,7 @@ struct mptcp_subflow_context { u8 hmac[MPTCPOPT_HMAC_LEN]; /* MPJ subflow only */ u64 iasn; /* initial ack sequence number, MPC subflows only */ }; - u8 local_id; + s16 local_id; /* if negative not initialized yet */ u8 remote_id; u8 reset_seen:1; u8 reset_transient:1; @@ -558,6 +557,7 @@ mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow) { memset(&subflow->reset, 0, sizeof(subflow->reset)); subflow->request_mptcp = 1; + WRITE_ONCE(subflow->local_id, -1); } static inline u64 @@ -1064,6 +1064,15 @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc); int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc); int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc); +static inline int subflow_get_local_id(struct mptcp_subflow_context *subflow) +{ + int local_id = READ_ONCE(subflow->local_id); + + if (local_id < 0) + return 0; + return local_id; +} + void __init mptcp_pm_nl_init(void); void mptcp_pm_nl_work(struct mptcp_sock *msk); void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 02dab0669cfc..068784d3e748 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -578,8 +578,8 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) static void subflow_set_local_id(struct mptcp_subflow_context *subflow, int local_id) { - subflow->local_id = local_id; - subflow->local_id_valid = 1; + WARN_ON_ONCE(local_id < 0 || local_id > 255); + WRITE_ONCE(subflow->local_id, local_id); } static int subflow_chk_local_id(struct sock *sk) @@ -588,7 +588,7 @@ static int subflow_chk_local_id(struct sock *sk) struct mptcp_sock *msk = mptcp_sk(subflow->conn); int err; - if (likely(subflow->local_id_valid)) + if (likely(subflow->local_id >= 0)) return 0; err = mptcp_pm_get_local_id(msk, (struct sock_common *)sk); @@ -1733,6 +1733,7 @@ static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, pr_debug("subflow=%p", ctx); ctx->tcp_sock = sk; + WRITE_ONCE(ctx->local_id, -1); return ctx; } @@ -1968,7 +1969,7 @@ static void subflow_ulp_clone(const struct request_sock *req, new_ctx->idsn = subflow_req->idsn; /* this is the first subflow, id is always 0 */ - new_ctx->local_id_valid = 1; + subflow_set_local_id(new_ctx, 0); } else if (subflow_req->mp_join) { new_ctx->ssn_offset = subflow_req->ssn_offset; new_ctx->mp_join = 1;
The local address id is accessed lockless by the NL PM, add all the required ONCE annotation. There is a caveat: the local id can be initialized late in the subflow life-cycle, and its validity is controlled by the local_id_valid flag. Remove such flag and encode the validity in the local_id field itself with negative value before initialization. That allows accessing the field consistently with a single read operation. Fixes: 0ee4261a3681 ("mptcp: implement mptcp_pm_remove_subflow") Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- net/mptcp/pm_netlink.c | 4 ++-- net/mptcp/protocol.c | 2 +- net/mptcp/protocol.h | 15 ++++++++++++--- net/mptcp/subflow.c | 9 +++++---- 4 files changed, 20 insertions(+), 10 deletions(-)