diff options
Diffstat (limited to 'net/mptcp/pm_netlink.c')
| -rw-r--r-- | net/mptcp/pm_netlink.c | 645 |
1 files changed, 645 insertions, 0 deletions
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c new file mode 100644 index 000000000000..d5b383870f79 --- /dev/null +++ b/net/mptcp/pm_netlink.c @@ -0,0 +1,645 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Multipath TCP + * + * Copyright (c) 2020, Red Hat, Inc. + */ + +#define pr_fmt(fmt) "MPTCP: " fmt + +#include "protocol.h" +#include "mptcp_pm_gen.h" + +#define MPTCP_PM_CMD_GRP_OFFSET 0 +#define MPTCP_PM_EV_GRP_OFFSET 1 + +static const struct genl_multicast_group mptcp_pm_mcgrps[] = { + [MPTCP_PM_CMD_GRP_OFFSET] = { .name = MPTCP_PM_CMD_GRP_NAME, }, + [MPTCP_PM_EV_GRP_OFFSET] = { .name = MPTCP_PM_EV_GRP_NAME, + .flags = GENL_MCAST_CAP_NET_ADMIN, + }, +}; + +static int mptcp_pm_family_to_addr(int family) +{ +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (family == AF_INET6) + return MPTCP_PM_ADDR_ATTR_ADDR6; +#endif + return MPTCP_PM_ADDR_ATTR_ADDR4; +} + +static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[], + const struct nlattr *attr, + struct genl_info *info, + struct mptcp_addr_info *addr, + bool require_family) +{ + int err, addr_addr; + + if (!attr) { + GENL_SET_ERR_MSG(info, "missing address info"); + return -EINVAL; + } + + /* no validation needed - was already done via nested policy */ + err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr, + mptcp_pm_address_nl_policy, info->extack); + if (err) + return err; + + if (tb[MPTCP_PM_ADDR_ATTR_ID]) + addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]); + + if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) { + if (!require_family) + return 0; + + NL_SET_ERR_MSG_ATTR(info->extack, attr, + "missing family"); + return -EINVAL; + } + + addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]); + if (addr->family != AF_INET +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + && addr->family != AF_INET6 +#endif + ) { + NL_SET_ERR_MSG_ATTR(info->extack, attr, + "unknown address family"); + return -EINVAL; + } + addr_addr = mptcp_pm_family_to_addr(addr->family); + if (!tb[addr_addr]) { + NL_SET_ERR_MSG_ATTR(info->extack, attr, + "missing address data"); + return -EINVAL; + } + +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (addr->family == AF_INET6) + addr->addr6 = nla_get_in6_addr(tb[addr_addr]); + else +#endif + addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]); + + if (tb[MPTCP_PM_ADDR_ATTR_PORT]) + addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT])); + + return 0; +} + +int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info, + struct mptcp_addr_info *addr) +{ + struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1]; + + memset(addr, 0, sizeof(*addr)); + + return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true); +} + +int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info, + bool require_family, + struct mptcp_pm_addr_entry *entry) +{ + struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1]; + int err; + + memset(entry, 0, sizeof(*entry)); + + err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family); + if (err) + return err; + + if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) { + s32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]); + + entry->ifindex = val; + } + + if (tb[MPTCP_PM_ADDR_ATTR_FLAGS]) + entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]); + + if (tb[MPTCP_PM_ADDR_ATTR_PORT]) + entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT])); + + return 0; +} + +static int mptcp_nl_fill_addr(struct sk_buff *skb, + struct mptcp_pm_addr_entry *entry) +{ + struct mptcp_addr_info *addr = &entry->addr; + struct nlattr *attr; + + attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR); + if (!attr) + return -EMSGSIZE; + + if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family)) + goto nla_put_failure; + if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port))) + goto nla_put_failure; + if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id)) + goto nla_put_failure; + if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags)) + goto nla_put_failure; + if (entry->ifindex && + nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex)) + goto nla_put_failure; + + if (addr->family == AF_INET && + nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4, + addr->addr.s_addr)) + goto nla_put_failure; +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + else if (addr->family == AF_INET6 && + nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6)) + goto nla_put_failure; +#endif + nla_nest_end(skb, attr); + return 0; + +nla_put_failure: + nla_nest_cancel(skb, attr); + return -EMSGSIZE; +} + +static int mptcp_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr, + struct genl_info *info) +{ + if (info->attrs[MPTCP_PM_ATTR_TOKEN]) + return mptcp_userspace_pm_get_addr(id, addr, info); + return mptcp_pm_nl_get_addr(id, addr, info); +} + +int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info) +{ + struct mptcp_pm_addr_entry addr; + struct nlattr *attr; + struct sk_buff *msg; + void *reply; + int ret; + + if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ENDPOINT_ADDR)) + return -EINVAL; + + attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR]; + ret = mptcp_pm_parse_entry(attr, info, false, &addr); + if (ret < 0) + return ret; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0, + info->genlhdr->cmd); + if (!reply) { + GENL_SET_ERR_MSG(info, "not enough space in Netlink message"); + ret = -EMSGSIZE; + goto fail; + } + + ret = mptcp_pm_get_addr(addr.addr.id, &addr, info); + if (ret) { + NL_SET_ERR_MSG_ATTR(info->extack, attr, "address not found"); + goto fail; + } + + ret = mptcp_nl_fill_addr(msg, &addr); + if (ret) + goto fail; + + genlmsg_end(msg, reply); + ret = genlmsg_reply(msg, info); + return ret; + +fail: + nlmsg_free(msg); + return ret; +} + +int mptcp_pm_genl_fill_addr(struct sk_buff *msg, + struct netlink_callback *cb, + struct mptcp_pm_addr_entry *entry) +{ + void *hdr; + + hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, &mptcp_genl_family, + NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR); + if (!hdr) + return -EINVAL; + + if (mptcp_nl_fill_addr(msg, entry) < 0) { + genlmsg_cancel(msg, hdr); + return -EINVAL; + } + + genlmsg_end(msg, hdr); + return 0; +} + +static int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb) +{ + const struct genl_info *info = genl_info_dump(cb); + + if (info->attrs[MPTCP_PM_ATTR_TOKEN]) + return mptcp_userspace_pm_dump_addr(msg, cb); + return mptcp_pm_nl_dump_addr(msg, cb); +} + +int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg, + struct netlink_callback *cb) +{ + return mptcp_pm_dump_addr(msg, cb); +} + +static int mptcp_pm_set_flags(struct genl_info *info) +{ + struct mptcp_pm_addr_entry loc = { .addr = { .family = AF_UNSPEC }, }; + struct nlattr *attr_loc; + int ret = -EINVAL; + + if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR)) + return ret; + + attr_loc = info->attrs[MPTCP_PM_ATTR_ADDR]; + ret = mptcp_pm_parse_entry(attr_loc, info, false, &loc); + if (ret < 0) + return ret; + + if (info->attrs[MPTCP_PM_ATTR_TOKEN]) + return mptcp_userspace_pm_set_flags(&loc, info); + return mptcp_pm_nl_set_flags(&loc, info); +} + +int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info) +{ + return mptcp_pm_set_flags(info); +} + +static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp) +{ + genlmsg_multicast_netns(&mptcp_genl_family, net, + nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp); +} + +bool mptcp_userspace_pm_active(const struct mptcp_sock *msk) +{ + return genl_has_listeners(&mptcp_genl_family, + sock_net((const struct sock *)msk), + MPTCP_PM_EV_GRP_OFFSET); +} + +static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk) +{ + const struct inet_sock *issk = inet_sk(ssk); + const struct mptcp_subflow_context *sf; + + if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family)) + return -EMSGSIZE; + + switch (ssk->sk_family) { + case AF_INET: + if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr)) + return -EMSGSIZE; + if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr)) + return -EMSGSIZE; + break; +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + case AF_INET6: { + if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &issk->pinet6->saddr)) + return -EMSGSIZE; + if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr)) + return -EMSGSIZE; + break; + } +#endif + default: + WARN_ON_ONCE(1); + return -EMSGSIZE; + } + + if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport)) + return -EMSGSIZE; + if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport)) + return -EMSGSIZE; + + sf = mptcp_subflow_ctx(ssk); + if (WARN_ON_ONCE(!sf)) + return -EINVAL; + + if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, subflow_get_local_id(sf))) + return -EMSGSIZE; + + if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id)) + return -EMSGSIZE; + + return 0; +} + +static int mptcp_event_put_token_and_ssk(struct sk_buff *skb, + const struct mptcp_sock *msk, + const struct sock *ssk) +{ + const struct sock *sk = (const struct sock *)msk; + const struct mptcp_subflow_context *sf; + u8 sk_err; + + if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token))) + return -EMSGSIZE; + + if (mptcp_event_add_subflow(skb, ssk)) + return -EMSGSIZE; + + sf = mptcp_subflow_ctx(ssk); + if (WARN_ON_ONCE(!sf)) + return -EINVAL; + + if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup)) + return -EMSGSIZE; + + if (ssk->sk_bound_dev_if && + nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if)) + return -EMSGSIZE; + + sk_err = READ_ONCE(ssk->sk_err); + if (sk_err && sk->sk_state == TCP_ESTABLISHED && + nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err)) + return -EMSGSIZE; + + return 0; +} + +static int mptcp_event_sub_established(struct sk_buff *skb, + const struct mptcp_sock *msk, + const struct sock *ssk) +{ + return mptcp_event_put_token_and_ssk(skb, msk, ssk); +} + +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; +} + +static int mptcp_event_created(struct sk_buff *skb, + const struct mptcp_sock *msk, + const struct sock *ssk) +{ + int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)); + u16 flags = 0; + + if (err) + return err; + + if (READ_ONCE(msk->pm.server_side)) { + flags |= MPTCP_PM_EV_FLAG_SERVER_SIDE; + + /* Deprecated, and only set when it is the server side */ + if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, 1)) + return -EMSGSIZE; + } + + if (READ_ONCE(msk->pm.remote_deny_join_id0)) + flags |= MPTCP_PM_EV_FLAG_DENY_JOIN_ID0; + + if (flags && nla_put_u16(skb, MPTCP_ATTR_FLAGS, flags)) + return -EMSGSIZE; + + return mptcp_event_add_subflow(skb, ssk); +} + +void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id) +{ + struct net *net = sock_net((const struct sock *)msk); + struct nlmsghdr *nlh; + struct sk_buff *skb; + + if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET)) + return; + + skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); + if (!skb) + return; + + nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED); + if (!nlh) + goto nla_put_failure; + + if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token))) + goto nla_put_failure; + + if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id)) + goto nla_put_failure; + + genlmsg_end(skb, nlh); + mptcp_nl_mcast_send(net, skb, GFP_ATOMIC); + return; + +nla_put_failure: + nlmsg_free(skb); +} + +void mptcp_event_addr_announced(const struct sock *ssk, + const struct mptcp_addr_info *info) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct mptcp_sock *msk = mptcp_sk(subflow->conn); + struct net *net = sock_net(ssk); + struct nlmsghdr *nlh; + struct sk_buff *skb; + + if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET)) + return; + + skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); + if (!skb) + return; + + nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, + MPTCP_EVENT_ANNOUNCED); + if (!nlh) + goto nla_put_failure; + + if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token))) + goto nla_put_failure; + + if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id)) + goto nla_put_failure; + + if (nla_put_be16(skb, MPTCP_ATTR_DPORT, + info->port == 0 ? + inet_sk(ssk)->inet_dport : + info->port)) + goto nla_put_failure; + + switch (info->family) { + case AF_INET: + if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr)) + goto nla_put_failure; + break; +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + case AF_INET6: + if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6)) + goto nla_put_failure; + break; +#endif + default: + WARN_ON_ONCE(1); + goto nla_put_failure; + } + + genlmsg_end(skb, nlh); + mptcp_nl_mcast_send(net, skb, GFP_ATOMIC); + return; + +nla_put_failure: + nlmsg_free(skb); +} + +void mptcp_event_pm_listener(const struct sock *ssk, + enum mptcp_event_type event) +{ + const struct inet_sock *issk = inet_sk(ssk); + struct net *net = sock_net(ssk); + struct nlmsghdr *nlh; + struct sk_buff *skb; + + if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET)) + return; + + skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!skb) + return; + + nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, event); + if (!nlh) + goto nla_put_failure; + + if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family)) + goto nla_put_failure; + + if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport)) + goto nla_put_failure; + + switch (ssk->sk_family) { + case AF_INET: + if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr)) + goto nla_put_failure; + break; +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + case AF_INET6: { + if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &issk->pinet6->saddr)) + goto nla_put_failure; + break; + } +#endif + default: + WARN_ON_ONCE(1); + goto nla_put_failure; + } + + genlmsg_end(skb, nlh); + mptcp_nl_mcast_send(net, skb, GFP_KERNEL); + return; + +nla_put_failure: + nlmsg_free(skb); +} + +void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk, + const struct sock *ssk, gfp_t gfp) +{ + struct net *net = sock_net((const struct sock *)msk); + struct nlmsghdr *nlh; + struct sk_buff *skb; + + if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET)) + return; + + skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp); + if (!skb) + return; + + nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type); + if (!nlh) + goto nla_put_failure; + + switch (type) { + case MPTCP_EVENT_UNSPEC: + WARN_ON_ONCE(1); + break; + case MPTCP_EVENT_CREATED: + case MPTCP_EVENT_ESTABLISHED: + if (mptcp_event_created(skb, msk, ssk) < 0) + goto nla_put_failure; + break; + case MPTCP_EVENT_CLOSED: + if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)) < 0) + goto nla_put_failure; + break; + case MPTCP_EVENT_ANNOUNCED: + case MPTCP_EVENT_REMOVED: + /* call mptcp_event_addr_announced()/removed instead */ + WARN_ON_ONCE(1); + break; + case MPTCP_EVENT_SUB_ESTABLISHED: + case MPTCP_EVENT_SUB_PRIORITY: + if (mptcp_event_sub_established(skb, msk, ssk) < 0) + goto nla_put_failure; + break; + case MPTCP_EVENT_SUB_CLOSED: + if (mptcp_event_sub_closed(skb, msk, ssk) < 0) + goto nla_put_failure; + break; + case MPTCP_EVENT_LISTENER_CREATED: + case MPTCP_EVENT_LISTENER_CLOSED: + break; + } + + genlmsg_end(skb, nlh); + mptcp_nl_mcast_send(net, skb, gfp); + return; + +nla_put_failure: + nlmsg_free(skb); +} + +struct genl_family mptcp_genl_family __ro_after_init = { + .name = MPTCP_PM_NAME, + .version = MPTCP_PM_VER, + .netnsok = true, + .module = THIS_MODULE, + .ops = mptcp_pm_nl_ops, + .n_ops = ARRAY_SIZE(mptcp_pm_nl_ops), + .resv_start_op = MPTCP_PM_CMD_SUBFLOW_DESTROY + 1, + .mcgrps = mptcp_pm_mcgrps, + .n_mcgrps = ARRAY_SIZE(mptcp_pm_mcgrps), +}; + +void __init mptcp_pm_nl_init(void) +{ + if (genl_register_family(&mptcp_genl_family)) + panic("Failed to register MPTCP PM netlink family\n"); +} |