| Message ID | 20210816162636.25611-5-fw@strlen.de (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Commit | efd9c3320c756d41b2185edf8cbae347b99939ae |
| Delegated to: | Mat Martineau |
| Headers | show |
| Series | mptcp: add SOL_MPTCP getsockopt support | expand |
On Mon, 16 Aug 2021, Florian Westphal wrote: > This retrieves the address pairs of all subflows currently > active for a given mptcp connection. > > It re-uses the same meta-header as for MPTCP_TCPINFO. > > A new structure is provided to hold the subflow > address data: > > struct mptcp_subflow_addrs { > union { > sa_family_t sa_family; Looks like the update to __kernel_sa_family_t was in the code but not the comment. > struct sockaddr sa_local; > struct sockaddr_in sin_local; > struct sockaddr_in6 sin6_local; > struct sockaddr_storage ss_local; > }; > union { > struct sockaddr sa_remote; > struct sockaddr_in sin_remote; > struct sockaddr_in6 sin6_remote; > struct sockaddr_storage ss_remote; > }; > }; > > Usage of the new getsockopt is very similar to > MPTCP_TCPINFO one. > > Userspace allocates a > 'struct mptcp_subflow_data', followed by one or > more 'struct mptcp_subflow_addrs', then inits the > mptcp_subflow_data structure as follows: > > struct mptcp_subflow_addrs *sf_addr; > struct mptcp_subflow_data *addr; > socklen_t olen = sizeof(*addr) + (8 * sizeof(*sf_addr)); > > addr = malloc(olen); > addr->size_subflow_data = sizeof(*addr); > addr->num_subflows = 0; > addr->size_kernel = 0; > addr->size_user = sizeof(struct mptcp_subflow_addrs); > > sf_addr = (struct mptcp_subflow_addrs *)(addr + 1); > > and then retrieves the endpoint addresses via: > ret = getsockopt(fd, SOL_MPTCP, MPTCP_SUBFLOW_ADDRS, > addr, &olen); > > If the call succeeds, kernel will have added up to 8 > endpoint addresses after the 'mptcp_subflow_data' header. > > Userspace needs to re-check 'olen' value to detect how > many bytes have been filled in by the kernel. > > Userspace can check addr->num_subflows to discover when > there were more subflows that available data space. ^^^^ than? > > Signed-off-by: Florian Westphal <fw@strlen.de> > --- > include/uapi/linux/mptcp.h | 17 +++++++ > net/mptcp/sockopt.c | 91 ++++++++++++++++++++++++++++++++++++++ > 2 files changed, 108 insertions(+) > > diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h > index 7c368fccd83e..c368c11a0ed9 100644 > --- a/include/uapi/linux/mptcp.h > +++ b/include/uapi/linux/mptcp.h > @@ -201,8 +201,25 @@ struct mptcp_subflow_data { > __u32 size_user; /* size of one element in data[] */ > } __attribute__((aligned(8))); > > +struct mptcp_subflow_addrs { > + union { > + __kernel_sa_family_t sa_family; > + struct sockaddr sa_local; > + struct sockaddr_in sin_local; > + struct sockaddr_in6 sin6_local; > + struct sockaddr_storage ss_local; > + }; > + union { > + struct sockaddr sa_remote; > + struct sockaddr_in sin_remote; > + struct sockaddr_in6 sin6_remote; > + struct sockaddr_storage ss_remote; > + }; > +}; > + > /* MPTCP socket options */ > #define MPTCP_INFO 1 > #define MPTCP_TCPINFO 2 > +#define MPTCP_SUBFLOW_ADDRS 3 > > #endif /* _UAPI_MPTCP_H */ > diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c > index 77838933760c..51c488108b80 100644 > --- a/net/mptcp/sockopt.c > +++ b/net/mptcp/sockopt.c > @@ -840,6 +840,95 @@ static int mptcp_getsockopt_tcpinfo(struct mptcp_sock *msk, char __user *optval, > return 0; > } > > +static void mptcp_get_sub_addrs(const struct sock *sk, struct mptcp_subflow_addrs *a) > +{ > + struct inet_sock *inet = inet_sk(sk); > + > + memset(a, 0, sizeof(*a)); > + > + if (sk->sk_family == AF_INET) { > + a->sin_local.sin_family = AF_INET; > + a->sin_local.sin_port = inet->inet_sport; > + a->sin_local.sin_addr.s_addr = inet->inet_rcv_saddr; > + > + if (!a->sin_local.sin_addr.s_addr) > + a->sin_local.sin_addr.s_addr = inet->inet_saddr; > + > + a->sin_remote.sin_family = AF_INET; > + a->sin_remote.sin_port = inet->inet_dport; > + a->sin_remote.sin_addr.s_addr = inet->inet_daddr; > +#if IS_ENABLED(CONFIG_IPV6) > + } else if (sk->sk_family == AF_INET6) { > + const struct ipv6_pinfo *np = inet6_sk(sk); > + > + a->sin6_local.sin6_family = AF_INET6; > + a->sin6_local.sin6_port = inet->inet_sport; > + > + if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) > + a->sin6_local.sin6_addr = np->saddr; > + else > + a->sin6_local.sin6_addr = sk->sk_v6_rcv_saddr; > + > + a->sin6_remote.sin6_family = AF_INET6; > + a->sin6_remote.sin6_port = inet->inet_dport; > + a->sin6_remote.sin6_addr = sk->sk_v6_daddr; > +#endif > + } > +} > + > +static int mptcp_getsockopt_subflow_addrs(struct mptcp_sock *msk, char __user *optval, > + int __user *optlen) > +{ > + struct mptcp_subflow_context *subflow; > + struct sock *sk = &msk->sk.icsk_inet.sk; Reverse-xmas... Other than these minor things, the kernel code looks good in patches 1-4. -Mat > + unsigned int sfcount = 0, copied = 0; > + struct mptcp_subflow_data sfd; > + char __user *addrptr; > + int len; > + > + len = mptcp_get_subflow_data(&sfd, optval, optlen); > + if (len < 0) > + return len; > + > + sfd.size_kernel = sizeof(struct mptcp_subflow_addrs); > + sfd.size_user = min_t(unsigned int, sfd.size_user, > + sizeof(struct mptcp_subflow_addrs)); > + > + addrptr = optval + sfd.size_subflow_data; > + > + lock_sock(sk); > + > + mptcp_for_each_subflow(msk, subflow) { > + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); > + > + ++sfcount; > + > + if (len && len >= sfd.size_user) { > + struct mptcp_subflow_addrs a; > + > + mptcp_get_sub_addrs(ssk, &a); > + > + if (copy_to_user(addrptr, &a, sfd.size_user)) { > + release_sock(sk); > + return -EFAULT; > + } > + > + addrptr += sfd.size_user; > + copied += sfd.size_user; > + len -= sfd.size_user; > + } > + } > + > + release_sock(sk); > + > + sfd.num_subflows = sfcount; > + > + if (mptcp_put_subflow_data(&sfd, optval, copied, optlen)) > + return -EFAULT; > + > + return 0; > +} > + > static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, > char __user *optval, int __user *optlen) > { > @@ -862,6 +951,8 @@ static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname, > return mptcp_getsockopt_info(msk, optval, optlen); > case MPTCP_TCPINFO: > return mptcp_getsockopt_tcpinfo(msk, optval, optlen); > + case MPTCP_SUBFLOW_ADDRS: > + return mptcp_getsockopt_subflow_addrs(msk, optval, optlen); > } > > return -EOPNOTSUPP; > -- > 2.31.1 > > > -- Mat Martineau Intel
diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h index 7c368fccd83e..c368c11a0ed9 100644 --- a/include/uapi/linux/mptcp.h +++ b/include/uapi/linux/mptcp.h @@ -201,8 +201,25 @@ struct mptcp_subflow_data { __u32 size_user; /* size of one element in data[] */ } __attribute__((aligned(8))); +struct mptcp_subflow_addrs { + union { + __kernel_sa_family_t sa_family; + struct sockaddr sa_local; + struct sockaddr_in sin_local; + struct sockaddr_in6 sin6_local; + struct sockaddr_storage ss_local; + }; + union { + struct sockaddr sa_remote; + struct sockaddr_in sin_remote; + struct sockaddr_in6 sin6_remote; + struct sockaddr_storage ss_remote; + }; +}; + /* MPTCP socket options */ #define MPTCP_INFO 1 #define MPTCP_TCPINFO 2 +#define MPTCP_SUBFLOW_ADDRS 3 #endif /* _UAPI_MPTCP_H */ diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 77838933760c..51c488108b80 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -840,6 +840,95 @@ static int mptcp_getsockopt_tcpinfo(struct mptcp_sock *msk, char __user *optval, return 0; } +static void mptcp_get_sub_addrs(const struct sock *sk, struct mptcp_subflow_addrs *a) +{ + struct inet_sock *inet = inet_sk(sk); + + memset(a, 0, sizeof(*a)); + + if (sk->sk_family == AF_INET) { + a->sin_local.sin_family = AF_INET; + a->sin_local.sin_port = inet->inet_sport; + a->sin_local.sin_addr.s_addr = inet->inet_rcv_saddr; + + if (!a->sin_local.sin_addr.s_addr) + a->sin_local.sin_addr.s_addr = inet->inet_saddr; + + a->sin_remote.sin_family = AF_INET; + a->sin_remote.sin_port = inet->inet_dport; + a->sin_remote.sin_addr.s_addr = inet->inet_daddr; +#if IS_ENABLED(CONFIG_IPV6) + } else if (sk->sk_family == AF_INET6) { + const struct ipv6_pinfo *np = inet6_sk(sk); + + a->sin6_local.sin6_family = AF_INET6; + a->sin6_local.sin6_port = inet->inet_sport; + + if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) + a->sin6_local.sin6_addr = np->saddr; + else + a->sin6_local.sin6_addr = sk->sk_v6_rcv_saddr; + + a->sin6_remote.sin6_family = AF_INET6; + a->sin6_remote.sin6_port = inet->inet_dport; + a->sin6_remote.sin6_addr = sk->sk_v6_daddr; +#endif + } +} + +static int mptcp_getsockopt_subflow_addrs(struct mptcp_sock *msk, char __user *optval, + int __user *optlen) +{ + struct mptcp_subflow_context *subflow; + struct sock *sk = &msk->sk.icsk_inet.sk; + unsigned int sfcount = 0, copied = 0; + struct mptcp_subflow_data sfd; + char __user *addrptr; + int len; + + len = mptcp_get_subflow_data(&sfd, optval, optlen); + if (len < 0) + return len; + + sfd.size_kernel = sizeof(struct mptcp_subflow_addrs); + sfd.size_user = min_t(unsigned int, sfd.size_user, + sizeof(struct mptcp_subflow_addrs)); + + addrptr = optval + sfd.size_subflow_data; + + lock_sock(sk); + + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + ++sfcount; + + if (len && len >= sfd.size_user) { + struct mptcp_subflow_addrs a; + + mptcp_get_sub_addrs(ssk, &a); + + if (copy_to_user(addrptr, &a, sfd.size_user)) { + release_sock(sk); + return -EFAULT; + } + + addrptr += sfd.size_user; + copied += sfd.size_user; + len -= sfd.size_user; + } + } + + release_sock(sk); + + sfd.num_subflows = sfcount; + + if (mptcp_put_subflow_data(&sfd, optval, copied, optlen)) + return -EFAULT; + + return 0; +} + static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, char __user *optval, int __user *optlen) { @@ -862,6 +951,8 @@ static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname, return mptcp_getsockopt_info(msk, optval, optlen); case MPTCP_TCPINFO: return mptcp_getsockopt_tcpinfo(msk, optval, optlen); + case MPTCP_SUBFLOW_ADDRS: + return mptcp_getsockopt_subflow_addrs(msk, optval, optlen); } return -EOPNOTSUPP;
This retrieves the address pairs of all subflows currently active for a given mptcp connection. It re-uses the same meta-header as for MPTCP_TCPINFO. A new structure is provided to hold the subflow address data: struct mptcp_subflow_addrs { union { sa_family_t sa_family; struct sockaddr sa_local; struct sockaddr_in sin_local; struct sockaddr_in6 sin6_local; struct sockaddr_storage ss_local; }; union { struct sockaddr sa_remote; struct sockaddr_in sin_remote; struct sockaddr_in6 sin6_remote; struct sockaddr_storage ss_remote; }; }; Usage of the new getsockopt is very similar to MPTCP_TCPINFO one. Userspace allocates a 'struct mptcp_subflow_data', followed by one or more 'struct mptcp_subflow_addrs', then inits the mptcp_subflow_data structure as follows: struct mptcp_subflow_addrs *sf_addr; struct mptcp_subflow_data *addr; socklen_t olen = sizeof(*addr) + (8 * sizeof(*sf_addr)); addr = malloc(olen); addr->size_subflow_data = sizeof(*addr); addr->num_subflows = 0; addr->size_kernel = 0; addr->size_user = sizeof(struct mptcp_subflow_addrs); sf_addr = (struct mptcp_subflow_addrs *)(addr + 1); and then retrieves the endpoint addresses via: ret = getsockopt(fd, SOL_MPTCP, MPTCP_SUBFLOW_ADDRS, addr, &olen); If the call succeeds, kernel will have added up to 8 endpoint addresses after the 'mptcp_subflow_data' header. Userspace needs to re-check 'olen' value to detect how many bytes have been filled in by the kernel. Userspace can check addr->num_subflows to discover when there were more subflows that available data space. Signed-off-by: Florian Westphal <fw@strlen.de> --- include/uapi/linux/mptcp.h | 17 +++++++ net/mptcp/sockopt.c | 91 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 108 insertions(+)