| Message ID | 20210811131523.6339-3-fw@strlen.de (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Paolo Abeni |
| Headers | show |
| Series | mptcp: add SOL_MPTCP getsockopt support | expand |
On Wed, 11 Aug 2021, Florian Westphal wrote: > Its not compatible with mptcp.org kernel one. > One really minor comment (since I know you're working on a v2): probably best to refer to "multipath-tcp.org", we've been using mptcp.org as a shorthand but we don't want to send people there. Mat > 1. mptcp.org defines a different 'struct mptcp_info', with embedded > userspace addresses to store additional data such as endpoint addresses. > > 2. Mat Martineau points out the mptcp.org approach doesn't work with > BPF_CGROUP_RUN_PROG_GETSOCKOPT() which assumes that copying in > optsize bytes from optval provides all data that got copied to > userspace. > > This provides mptcp_info data for the given mptcp socket. > > Userspace sets optlen to the size of the structure it expects. > The kernel updates it to contain the number of bytes that it copied. > > This allows to append more information to the structure later. > > Signed-off-by: Florian Westphal <fw@strlen.de> > --- > include/linux/socket.h | 1 + > include/uapi/linux/mptcp.h | 4 ++++ > net/mptcp/sockopt.c | 40 +++++++++++++++++++++++++++++++++++++- > 3 files changed, 44 insertions(+), 1 deletion(-) > > diff --git a/include/linux/socket.h b/include/linux/socket.h > index fd9ce51582d8..a2326a963232 100644 > --- a/include/linux/socket.h > +++ b/include/linux/socket.h > @@ -364,6 +364,7 @@ struct ucred { > #define SOL_KCM 281 > #define SOL_TLS 282 > #define SOL_XDP 283 > +#define SOL_MPTCP 284 > > /* IPX options */ > #define IPX_TYPE 1 > diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h > index f66038b9551f..c450feba6f9c 100644 > --- a/include/uapi/linux/mptcp.h > +++ b/include/uapi/linux/mptcp.h > @@ -4,6 +4,7 @@ > > #include <linux/const.h> > #include <linux/types.h> > +#include <linux/in.h> > > #define MPTCP_SUBFLOW_FLAG_MCAP_REM _BITUL(0) > #define MPTCP_SUBFLOW_FLAG_MCAP_LOC _BITUL(1) > @@ -193,4 +194,7 @@ enum mptcp_event_attr { > #define MPTCP_RST_EBADPERF 5 > #define MPTCP_RST_EMIDDLEBOX 6 > > +/* MPTCP socket options */ > +#define MPTCP_INFO 1 > + > #endif /* _UAPI_MPTCP_H */ > diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c > index 54f0d521a399..eba294a071c8 100644 > --- a/net/mptcp/sockopt.c > +++ b/net/mptcp/sockopt.c > @@ -673,10 +673,14 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int > void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) > { > struct sock *sk = &msk->sk.icsk_inet.sk; > - bool slow = lock_sock_fast(sk); > u32 flags = 0; > + bool slow; > u8 val; > > + memset(info, 0, sizeof(*info)); > + > + slow = lock_sock_fast(sk); > + > info->mptcpi_subflows = READ_ONCE(msk->pm.subflows); > info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled); > info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted); > @@ -702,6 +706,27 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) > } > EXPORT_SYMBOL_GPL(mptcp_diag_fill_info); > > +static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, int __user *_u_optlen) > +{ > + struct mptcp_info m_info; > + int len; > + > + if (get_user(len, _u_optlen)) > + return -EFAULT; > + > + len = min_t(unsigned int, len, sizeof(struct mptcp_info)); > + > + mptcp_diag_fill_info(msk, &m_info); > + > + if (put_user(len, _u_optlen)) > + return -EFAULT; > + > + if (copy_to_user(optval, &m_info, len)) > + return -EFAULT; > + > + return 0; > +} > + > static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, > char __user *optval, int __user *optlen) > { > @@ -716,6 +741,17 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, > return -EOPNOTSUPP; > } > > +static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname, > + char __user *optval, int __user *optlen) > +{ > + switch (optname) { > + case MPTCP_INFO: > + return mptcp_getsockopt_info(msk, optval, optlen); > + } > + > + return -EOPNOTSUPP; > +} > + > int mptcp_getsockopt(struct sock *sk, int level, int optname, > char __user *optval, int __user *option) > { > @@ -738,6 +774,8 @@ int mptcp_getsockopt(struct sock *sk, int level, int optname, > > if (level == SOL_TCP) > return mptcp_getsockopt_sol_tcp(msk, optname, optval, option); > + if (level == SOL_MPTCP) > + return mptcp_getsockopt_sol_mptcp(msk, optname, optval, option); > return -EOPNOTSUPP; > } > > -- > 2.31.1 > > > -- Mat Martineau Intel
diff --git a/include/linux/socket.h b/include/linux/socket.h index fd9ce51582d8..a2326a963232 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -364,6 +364,7 @@ struct ucred { #define SOL_KCM 281 #define SOL_TLS 282 #define SOL_XDP 283 +#define SOL_MPTCP 284 /* IPX options */ #define IPX_TYPE 1 diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h index f66038b9551f..c450feba6f9c 100644 --- a/include/uapi/linux/mptcp.h +++ b/include/uapi/linux/mptcp.h @@ -4,6 +4,7 @@ #include <linux/const.h> #include <linux/types.h> +#include <linux/in.h> #define MPTCP_SUBFLOW_FLAG_MCAP_REM _BITUL(0) #define MPTCP_SUBFLOW_FLAG_MCAP_LOC _BITUL(1) @@ -193,4 +194,7 @@ enum mptcp_event_attr { #define MPTCP_RST_EBADPERF 5 #define MPTCP_RST_EMIDDLEBOX 6 +/* MPTCP socket options */ +#define MPTCP_INFO 1 + #endif /* _UAPI_MPTCP_H */ diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 54f0d521a399..eba294a071c8 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -673,10 +673,14 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) { struct sock *sk = &msk->sk.icsk_inet.sk; - bool slow = lock_sock_fast(sk); u32 flags = 0; + bool slow; u8 val; + memset(info, 0, sizeof(*info)); + + slow = lock_sock_fast(sk); + info->mptcpi_subflows = READ_ONCE(msk->pm.subflows); info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled); info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted); @@ -702,6 +706,27 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) } EXPORT_SYMBOL_GPL(mptcp_diag_fill_info); +static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, int __user *_u_optlen) +{ + struct mptcp_info m_info; + int len; + + if (get_user(len, _u_optlen)) + return -EFAULT; + + len = min_t(unsigned int, len, sizeof(struct mptcp_info)); + + mptcp_diag_fill_info(msk, &m_info); + + if (put_user(len, _u_optlen)) + return -EFAULT; + + if (copy_to_user(optval, &m_info, len)) + return -EFAULT; + + return 0; +} + static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, char __user *optval, int __user *optlen) { @@ -716,6 +741,17 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, return -EOPNOTSUPP; } +static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname, + char __user *optval, int __user *optlen) +{ + switch (optname) { + case MPTCP_INFO: + return mptcp_getsockopt_info(msk, optval, optlen); + } + + return -EOPNOTSUPP; +} + int mptcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *option) { @@ -738,6 +774,8 @@ int mptcp_getsockopt(struct sock *sk, int level, int optname, if (level == SOL_TCP) return mptcp_getsockopt_sol_tcp(msk, optname, optval, option); + if (level == SOL_MPTCP) + return mptcp_getsockopt_sol_mptcp(msk, optname, optval, option); return -EOPNOTSUPP; }
Its not compatible with mptcp.org kernel one. 1. mptcp.org defines a different 'struct mptcp_info', with embedded userspace addresses to store additional data such as endpoint addresses. 2. Mat Martineau points out the mptcp.org approach doesn't work with BPF_CGROUP_RUN_PROG_GETSOCKOPT() which assumes that copying in optsize bytes from optval provides all data that got copied to userspace. This provides mptcp_info data for the given mptcp socket. Userspace sets optlen to the size of the structure it expects. The kernel updates it to contain the number of bytes that it copied. This allows to append more information to the structure later. Signed-off-by: Florian Westphal <fw@strlen.de> --- include/linux/socket.h | 1 + include/uapi/linux/mptcp.h | 4 ++++ net/mptcp/sockopt.c | 40 +++++++++++++++++++++++++++++++++++++- 3 files changed, 44 insertions(+), 1 deletion(-)