From 702c2f646d42cfd9e31133d68a8283fea48fd810 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 3 May 2022 19:38:56 -0700 Subject: mptcp: netlink: allow userspace-driven subflow establishment This allows userspace to tell kernel to add a new subflow to an existing mptcp connection. Userspace provides the token to identify the mptcp-level connection that needs a change in active subflows and the local and remote addresses of the new or the to-be-removed subflow. MPTCP_PM_CMD_SUBFLOW_CREATE requires the following parameters: { token, { loc_id, family, loc_addr4 | loc_addr6 }, { family, rem_addr4 | rem_addr6, rem_port } MPTCP_PM_CMD_SUBFLOW_DESTROY requires the following parameters: { token, { family, loc_addr4 | loc_addr6, loc_port }, { family, rem_addr4 | rem_addr6, rem_port } Acked-by: Paolo Abeni Co-developed-by: Kishen Maloor Signed-off-by: Kishen Maloor Signed-off-by: Florian Westphal Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/pm_userspace.c | 185 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 185 insertions(+) (limited to 'net/mptcp/pm_userspace.c') diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index 3a42c9e66126..f56378e4f597 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -242,3 +242,188 @@ int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info) sock_put((struct sock *)msk); return err; } + +int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info) +{ + struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE]; + struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN]; + struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR]; + struct mptcp_addr_info addr_r; + struct mptcp_addr_info addr_l; + struct mptcp_sock *msk; + int err = -EINVAL; + struct sock *sk; + u32 token_val; + + if (!laddr || !raddr || !token) { + GENL_SET_ERR_MSG(info, "missing required inputs"); + return err; + } + + token_val = nla_get_u32(token); + + msk = mptcp_token_get_sock(genl_info_net(info), token_val); + if (!msk) { + NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token"); + return err; + } + + if (!mptcp_pm_is_userspace(msk)) { + GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected"); + goto create_err; + } + + err = mptcp_pm_parse_addr(laddr, info, &addr_l); + if (err < 0) { + NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr"); + goto create_err; + } + + if (addr_l.id == 0) { + NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id"); + goto create_err; + } + + err = mptcp_pm_parse_addr(raddr, info, &addr_r); + if (err < 0) { + NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr"); + goto create_err; + } + + sk = &msk->sk.icsk_inet.sk; + lock_sock(sk); + + err = __mptcp_subflow_connect(sk, &addr_l, &addr_r); + + release_sock(sk); + + create_err: + sock_put((struct sock *)msk); + return err; +} + +static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk, + const struct mptcp_addr_info *local, + const struct mptcp_addr_info *remote) +{ + struct sock *sk = &msk->sk.icsk_inet.sk; + struct mptcp_subflow_context *subflow; + struct sock *found = NULL; + + if (local->family != remote->family) + return NULL; + + lock_sock(sk); + + mptcp_for_each_subflow(msk, subflow) { + const struct inet_sock *issk; + struct sock *ssk; + + ssk = mptcp_subflow_tcp_sock(subflow); + + if (local->family != ssk->sk_family) + continue; + + issk = inet_sk(ssk); + + switch (ssk->sk_family) { + case AF_INET: + if (issk->inet_saddr != local->addr.s_addr || + issk->inet_daddr != remote->addr.s_addr) + continue; + break; +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + case AF_INET6: { + const struct ipv6_pinfo *pinfo = inet6_sk(ssk); + + if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) || + !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr)) + continue; + break; + } +#endif + default: + continue; + } + + if (issk->inet_sport == local->port && + issk->inet_dport == remote->port) { + found = ssk; + goto found; + } + } + +found: + release_sock(sk); + + return found; +} + +int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info) +{ + struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE]; + struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN]; + struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR]; + struct mptcp_addr_info addr_l; + struct mptcp_addr_info addr_r; + struct mptcp_sock *msk; + struct sock *sk, *ssk; + int err = -EINVAL; + u32 token_val; + + if (!laddr || !raddr || !token) { + GENL_SET_ERR_MSG(info, "missing required inputs"); + return err; + } + + token_val = nla_get_u32(token); + + msk = mptcp_token_get_sock(genl_info_net(info), token_val); + if (!msk) { + NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token"); + return err; + } + + if (!mptcp_pm_is_userspace(msk)) { + GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected"); + goto destroy_err; + } + + err = mptcp_pm_parse_addr(laddr, info, &addr_l); + if (err < 0) { + NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr"); + goto destroy_err; + } + + err = mptcp_pm_parse_addr(raddr, info, &addr_r); + if (err < 0) { + NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr"); + goto destroy_err; + } + + if (addr_l.family != addr_r.family) { + GENL_SET_ERR_MSG(info, "address families do not match"); + goto destroy_err; + } + + if (!addr_l.port || !addr_r.port) { + GENL_SET_ERR_MSG(info, "missing local or remote port"); + goto destroy_err; + } + + sk = &msk->sk.icsk_inet.sk; + ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r); + if (ssk) { + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + + mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN); + mptcp_close_ssk(sk, ssk, subflow); + err = 0; + } else { + err = -ESRCH; + } + + destroy_err: + sock_put((struct sock *)msk); + return err; +} -- cgit