diff options
Diffstat (limited to 'net/ipv4/tcp_diag.c')
| -rw-r--r-- | net/ipv4/tcp_diag.c | 665 |
1 files changed, 642 insertions, 23 deletions
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c index ed3f2ad42e0f..d83efd91f461 100644 --- a/net/ipv4/tcp_diag.c +++ b/net/ipv4/tcp_diag.c @@ -1,56 +1,674 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * tcp_diag.c Module for monitoring TCP transport protocols sockets. * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. */ - #include <linux/module.h> +#include <linux/net.h> +#include <linux/sock_diag.h> #include <linux/inet_diag.h> #include <linux/tcp.h> +#include <net/inet_hashtables.h> +#include <net/inet6_hashtables.h> +#include <net/inet_timewait_sock.h> +#include <net/netlink.h> #include <net/tcp.h> static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, void *_info) { - const struct tcp_sock *tp = tcp_sk(sk); struct tcp_info *info = _info; - if (sk->sk_state == TCP_LISTEN) { - r->idiag_rqueue = sk->sk_ack_backlog; - r->idiag_wqueue = sk->sk_max_ack_backlog; - } else { - r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); - r->idiag_wqueue = tp->write_seq - tp->snd_una; + if (inet_sk_state_load(sk) == TCP_LISTEN) { + r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog); + r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog); + } else if (sk->sk_type == SOCK_STREAM) { + const struct tcp_sock *tp = tcp_sk(sk); + + r->idiag_rqueue = max_t(int, READ_ONCE(tp->rcv_nxt) - + READ_ONCE(tp->copied_seq), 0); + r->idiag_wqueue = READ_ONCE(tp->write_seq) - tp->snd_una; } - if (info != NULL) + if (info) tcp_get_info(sk, info); } +#ifdef CONFIG_TCP_MD5SIG +static void tcp_diag_md5sig_fill(struct tcp_diag_md5sig *info, + const struct tcp_md5sig_key *key) +{ + info->tcpm_family = key->family; + info->tcpm_prefixlen = key->prefixlen; + info->tcpm_keylen = key->keylen; + memcpy(info->tcpm_key, key->key, key->keylen); + + if (key->family == AF_INET) + info->tcpm_addr[0] = key->addr.a4.s_addr; + #if IS_ENABLED(CONFIG_IPV6) + else if (key->family == AF_INET6) + memcpy(&info->tcpm_addr, &key->addr.a6, + sizeof(info->tcpm_addr)); + #endif +} + +static int tcp_diag_put_md5sig(struct sk_buff *skb, + const struct tcp_md5sig_info *md5sig) +{ + const struct tcp_md5sig_key *key; + struct tcp_diag_md5sig *info; + struct nlattr *attr; + int md5sig_count = 0; + + hlist_for_each_entry_rcu(key, &md5sig->head, node) + md5sig_count++; + if (md5sig_count == 0) + return 0; + + attr = nla_reserve(skb, INET_DIAG_MD5SIG, + md5sig_count * sizeof(struct tcp_diag_md5sig)); + if (!attr) + return -EMSGSIZE; + + info = nla_data(attr); + memset(info, 0, md5sig_count * sizeof(struct tcp_diag_md5sig)); + hlist_for_each_entry_rcu(key, &md5sig->head, node) { + tcp_diag_md5sig_fill(info++, key); + if (--md5sig_count == 0) + break; + } + + return 0; +} +#endif + +static int tcp_diag_put_ulp(struct sk_buff *skb, struct sock *sk, + const struct tcp_ulp_ops *ulp_ops, bool net_admin) +{ + struct nlattr *nest; + int err; + + nest = nla_nest_start_noflag(skb, INET_DIAG_ULP_INFO); + if (!nest) + return -EMSGSIZE; + + err = nla_put_string(skb, INET_ULP_INFO_NAME, ulp_ops->name); + if (err) + goto nla_failure; + + if (ulp_ops->get_info) + err = ulp_ops->get_info(sk, skb, net_admin); + if (err) + goto nla_failure; + + nla_nest_end(skb, nest); + return 0; + +nla_failure: + nla_nest_cancel(skb, nest); + return err; +} + +static int tcp_diag_get_aux(struct sock *sk, bool net_admin, + struct sk_buff *skb) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + const struct tcp_ulp_ops *ulp_ops; + int err = 0; + +#ifdef CONFIG_TCP_MD5SIG + if (net_admin) { + struct tcp_md5sig_info *md5sig; + + rcu_read_lock(); + md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info); + if (md5sig) + err = tcp_diag_put_md5sig(skb, md5sig); + rcu_read_unlock(); + if (err < 0) + return err; + } +#endif + + ulp_ops = icsk->icsk_ulp_ops; + if (ulp_ops) { + err = tcp_diag_put_ulp(skb, sk, ulp_ops, net_admin); + if (err < 0) + return err; + } + + return 0; +} + +static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + size_t size = 0; + +#ifdef CONFIG_TCP_MD5SIG + if (net_admin && sk_fullsock(sk)) { + const struct tcp_md5sig_info *md5sig; + const struct tcp_md5sig_key *key; + size_t md5sig_count = 0; + + rcu_read_lock(); + md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info); + if (md5sig) { + hlist_for_each_entry_rcu(key, &md5sig->head, node) + md5sig_count++; + } + rcu_read_unlock(); + size += nla_total_size(md5sig_count * + sizeof(struct tcp_diag_md5sig)); + } +#endif + + if (sk_fullsock(sk)) { + const struct tcp_ulp_ops *ulp_ops; + + ulp_ops = icsk->icsk_ulp_ops; + if (ulp_ops) { + size += nla_total_size(0) + + nla_total_size(TCP_ULP_NAME_MAX); + if (ulp_ops->get_info_size) + size += ulp_ops->get_info_size(sk, net_admin); + } + } + + return size + + nla_total_size(sizeof(struct tcp_info)) + + nla_total_size(sizeof(struct inet_diag_msg)) + + inet_diag_msg_attrs_size() + + nla_total_size(sizeof(struct inet_diag_meminfo)) + + nla_total_size(SK_MEMINFO_VARS * sizeof(u32)) + + nla_total_size(TCP_CA_NAME_MAX) + + nla_total_size(sizeof(struct tcpvegas_info)) + + 64; +} + +static int tcp_twsk_diag_fill(struct sock *sk, + struct sk_buff *skb, + struct netlink_callback *cb, + u16 nlmsg_flags, bool net_admin) +{ + struct inet_timewait_sock *tw = inet_twsk(sk); + struct inet_diag_msg *r; + struct nlmsghdr *nlh; + long tmo; + + nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, cb->nlh->nlmsg_type, + sizeof(*r), nlmsg_flags); + if (!nlh) + return -EMSGSIZE; + + r = nlmsg_data(nlh); + DEBUG_NET_WARN_ON_ONCE(tw->tw_state != TCP_TIME_WAIT); + + inet_diag_msg_common_fill(r, sk); + r->idiag_retrans = 0; + + r->idiag_state = READ_ONCE(tw->tw_substate); + r->idiag_timer = 3; + tmo = tw->tw_timer.expires - jiffies; + r->idiag_expires = jiffies_delta_to_msecs(tmo); + r->idiag_rqueue = 0; + r->idiag_wqueue = 0; + r->idiag_uid = 0; + r->idiag_inode = 0; + + if (net_admin && nla_put_u32(skb, INET_DIAG_MARK, + tw->tw_mark)) { + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; + } + + nlmsg_end(skb, nlh); + return 0; +} + +static int tcp_req_diag_fill(struct sock *sk, struct sk_buff *skb, + struct netlink_callback *cb, + u16 nlmsg_flags, bool net_admin) +{ + struct request_sock *reqsk = inet_reqsk(sk); + struct inet_diag_msg *r; + struct nlmsghdr *nlh; + long tmo; + + nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, + cb->nlh->nlmsg_type, sizeof(*r), nlmsg_flags); + if (!nlh) + return -EMSGSIZE; + + r = nlmsg_data(nlh); + inet_diag_msg_common_fill(r, sk); + r->idiag_state = TCP_SYN_RECV; + r->idiag_timer = 1; + r->idiag_retrans = READ_ONCE(reqsk->num_retrans); + + BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) != + offsetof(struct sock, sk_cookie)); + + tmo = READ_ONCE(inet_reqsk(sk)->rsk_timer.expires) - jiffies; + r->idiag_expires = jiffies_delta_to_msecs(tmo); + r->idiag_rqueue = 0; + r->idiag_wqueue = 0; + r->idiag_uid = 0; + r->idiag_inode = 0; + + if (net_admin && nla_put_u32(skb, INET_DIAG_MARK, + inet_rsk(reqsk)->ir_mark)) { + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; + } + + nlmsg_end(skb, nlh); + return 0; +} + +static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, + struct netlink_callback *cb, + const struct inet_diag_req_v2 *r, + u16 nlmsg_flags, bool net_admin) +{ + if (sk->sk_state == TCP_TIME_WAIT) + return tcp_twsk_diag_fill(sk, skb, cb, nlmsg_flags, net_admin); + + if (sk->sk_state == TCP_NEW_SYN_RECV) + return tcp_req_diag_fill(sk, skb, cb, nlmsg_flags, net_admin); + + return inet_sk_diag_fill(sk, inet_csk(sk), skb, cb, r, nlmsg_flags, + net_admin); +} + +static void twsk_build_assert(void) +{ + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_family) != + offsetof(struct sock, sk_family)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_num) != + offsetof(struct inet_sock, inet_num)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_dport) != + offsetof(struct inet_sock, inet_dport)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_rcv_saddr) != + offsetof(struct inet_sock, inet_rcv_saddr)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_daddr) != + offsetof(struct inet_sock, inet_daddr)); + +#if IS_ENABLED(CONFIG_IPV6) + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_rcv_saddr) != + offsetof(struct sock, sk_v6_rcv_saddr)); + + BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_daddr) != + offsetof(struct sock, sk_v6_daddr)); +#endif +} + static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, - struct inet_diag_req_v2 *r, struct nlattr *bc) + const struct inet_diag_req_v2 *r) +{ + bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN); + struct inet_diag_dump_data *cb_data = cb->data; + struct net *net = sock_net(skb->sk); + u32 idiag_states = r->idiag_states; + struct inet_hashinfo *hashinfo; + int i, num, s_i, s_num; + struct sock *sk; + + hashinfo = net->ipv4.tcp_death_row.hashinfo; + if (idiag_states & TCPF_SYN_RECV) + idiag_states |= TCPF_NEW_SYN_RECV; + s_i = cb->args[1]; + s_num = num = cb->args[2]; + + if (cb->args[0] == 0) { + if (!(idiag_states & TCPF_LISTEN) || r->id.idiag_dport) + goto skip_listen_ht; + + for (i = s_i; i <= hashinfo->lhash2_mask; i++) { + struct inet_listen_hashbucket *ilb; + struct hlist_nulls_node *node; + + num = 0; + ilb = &hashinfo->lhash2[i]; + + if (hlist_nulls_empty(&ilb->nulls_head)) { + s_num = 0; + continue; + } + spin_lock(&ilb->lock); + sk_nulls_for_each(sk, node, &ilb->nulls_head) { + struct inet_sock *inet = inet_sk(sk); + + if (!net_eq(sock_net(sk), net)) + continue; + + if (num < s_num) { + num++; + continue; + } + + if (r->sdiag_family != AF_UNSPEC && + sk->sk_family != r->sdiag_family) + goto next_listen; + + if (r->id.idiag_sport != inet->inet_sport && + r->id.idiag_sport) + goto next_listen; + + if (!inet_diag_bc_sk(cb_data, sk)) + goto next_listen; + + if (inet_sk_diag_fill(sk, inet_csk(sk), skb, + cb, r, NLM_F_MULTI, + net_admin) < 0) { + spin_unlock(&ilb->lock); + goto done; + } + +next_listen: + ++num; + } + spin_unlock(&ilb->lock); + + s_num = 0; + } +skip_listen_ht: + cb->args[0] = 1; + s_i = num = s_num = 0; + } + +/* Process a maximum of SKARR_SZ sockets at a time when walking hash buckets + * with bh disabled. + */ +#define SKARR_SZ 16 + + /* Dump bound but inactive (not listening, connecting, etc.) sockets */ + if (cb->args[0] == 1) { + if (!(idiag_states & TCPF_BOUND_INACTIVE)) + goto skip_bind_ht; + + for (i = s_i; i < hashinfo->bhash_size; i++) { + struct inet_bind_hashbucket *ibb; + struct inet_bind2_bucket *tb2; + struct sock *sk_arr[SKARR_SZ]; + int num_arr[SKARR_SZ]; + int idx, accum, res; + +resume_bind_walk: + num = 0; + accum = 0; + ibb = &hashinfo->bhash2[i]; + + if (hlist_empty(&ibb->chain)) { + s_num = 0; + continue; + } + spin_lock_bh(&ibb->lock); + inet_bind_bucket_for_each(tb2, &ibb->chain) { + if (!net_eq(ib2_net(tb2), net)) + continue; + + sk_for_each_bound(sk, &tb2->owners) { + struct inet_sock *inet = inet_sk(sk); + + if (num < s_num) + goto next_bind; + + if (sk->sk_state != TCP_CLOSE || + !inet->inet_num) + goto next_bind; + + if (r->sdiag_family != AF_UNSPEC && + r->sdiag_family != sk->sk_family) + goto next_bind; + + if (!inet_diag_bc_sk(cb_data, sk)) + goto next_bind; + + sock_hold(sk); + num_arr[accum] = num; + sk_arr[accum] = sk; + if (++accum == SKARR_SZ) + goto pause_bind_walk; +next_bind: + num++; + } + } +pause_bind_walk: + spin_unlock_bh(&ibb->lock); + + res = 0; + for (idx = 0; idx < accum; idx++) { + if (res >= 0) { + res = inet_sk_diag_fill(sk_arr[idx], + NULL, skb, cb, + r, NLM_F_MULTI, + net_admin); + if (res < 0) + num = num_arr[idx]; + } + sock_put(sk_arr[idx]); + } + if (res < 0) + goto done; + + cond_resched(); + + if (accum == SKARR_SZ) { + s_num = num + 1; + goto resume_bind_walk; + } + + s_num = 0; + } +skip_bind_ht: + cb->args[0] = 2; + s_i = num = s_num = 0; + } + + if (!(idiag_states & ~TCPF_LISTEN)) + goto out; + + for (i = s_i; i <= hashinfo->ehash_mask; i++) { + struct inet_ehash_bucket *head = &hashinfo->ehash[i]; + spinlock_t *lock = inet_ehash_lockp(hashinfo, i); + struct hlist_nulls_node *node; + struct sock *sk_arr[SKARR_SZ]; + int num_arr[SKARR_SZ]; + int idx, accum, res; + + if (hlist_nulls_empty(&head->chain)) + continue; + + if (i > s_i) + s_num = 0; + +next_chunk: + num = 0; + accum = 0; + spin_lock_bh(lock); + sk_nulls_for_each(sk, node, &head->chain) { + int state; + + if (!net_eq(sock_net(sk), net)) + continue; + if (num < s_num) + goto next_normal; + state = (sk->sk_state == TCP_TIME_WAIT) ? + READ_ONCE(inet_twsk(sk)->tw_substate) : sk->sk_state; + if (!(idiag_states & (1 << state))) + goto next_normal; + if (r->sdiag_family != AF_UNSPEC && + sk->sk_family != r->sdiag_family) + goto next_normal; + if (r->id.idiag_sport != htons(sk->sk_num) && + r->id.idiag_sport) + goto next_normal; + if (r->id.idiag_dport != sk->sk_dport && + r->id.idiag_dport) + goto next_normal; + twsk_build_assert(); + + if (!inet_diag_bc_sk(cb_data, sk)) + goto next_normal; + + if (!refcount_inc_not_zero(&sk->sk_refcnt)) + goto next_normal; + + num_arr[accum] = num; + sk_arr[accum] = sk; + if (++accum == SKARR_SZ) + break; +next_normal: + ++num; + } + spin_unlock_bh(lock); + + res = 0; + for (idx = 0; idx < accum; idx++) { + if (res >= 0) { + res = sk_diag_fill(sk_arr[idx], skb, cb, r, + NLM_F_MULTI, net_admin); + if (res < 0) + num = num_arr[idx]; + } + sock_gen_put(sk_arr[idx]); + } + if (res < 0) + break; + + cond_resched(); + + if (accum == SKARR_SZ) { + s_num = num + 1; + goto next_chunk; + } + } + +done: + cb->args[1] = i; + cb->args[2] = num; +out: + ; +} + +static struct sock *tcp_diag_find_one_icsk(struct net *net, + const struct inet_diag_req_v2 *req) +{ + struct sock *sk; + + rcu_read_lock(); + if (req->sdiag_family == AF_INET) { + sk = inet_lookup(net, NULL, 0, req->id.idiag_dst[0], + req->id.idiag_dport, req->id.idiag_src[0], + req->id.idiag_sport, req->id.idiag_if); +#if IS_ENABLED(CONFIG_IPV6) + } else if (req->sdiag_family == AF_INET6) { + if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) && + ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src)) + sk = inet_lookup(net, NULL, 0, req->id.idiag_dst[3], + req->id.idiag_dport, req->id.idiag_src[3], + req->id.idiag_sport, req->id.idiag_if); + else + sk = inet6_lookup(net, NULL, 0, + (struct in6_addr *)req->id.idiag_dst, + req->id.idiag_dport, + (struct in6_addr *)req->id.idiag_src, + req->id.idiag_sport, + req->id.idiag_if); +#endif + } else { + rcu_read_unlock(); + return ERR_PTR(-EINVAL); + } + rcu_read_unlock(); + if (!sk) + return ERR_PTR(-ENOENT); + + if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) { + sock_gen_put(sk); + return ERR_PTR(-ENOENT); + } + + return sk; +} + +static int tcp_diag_dump_one(struct netlink_callback *cb, + const struct inet_diag_req_v2 *req) { - inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc); + struct sk_buff *in_skb = cb->skb; + struct sk_buff *rep; + struct sock *sk; + struct net *net; + bool net_admin; + int err; + + net = sock_net(in_skb->sk); + sk = tcp_diag_find_one_icsk(net, req); + if (IS_ERR(sk)) + return PTR_ERR(sk); + + net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN); + rep = nlmsg_new(tcp_diag_get_aux_size(sk, net_admin), GFP_KERNEL); + if (!rep) { + err = -ENOMEM; + goto out; + } + + err = sk_diag_fill(sk, rep, cb, req, 0, net_admin); + if (err < 0) { + WARN_ON(err == -EMSGSIZE); + nlmsg_free(rep); + goto out; + } + err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid); + +out: + if (sk) + sock_gen_put(sk); + + return err; } -static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh, - struct inet_diag_req_v2 *req) +#ifdef CONFIG_INET_DIAG_DESTROY +static int tcp_diag_destroy(struct sk_buff *in_skb, + const struct inet_diag_req_v2 *req) { - return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req); + struct net *net = sock_net(in_skb->sk); + struct sock *sk; + int err; + + sk = tcp_diag_find_one_icsk(net, req); + if (IS_ERR(sk)) + return PTR_ERR(sk); + + err = sock_diag_destroy(sk, ECONNABORTED); + + sock_gen_put(sk); + + return err; } +#endif static const struct inet_diag_handler tcp_diag_handler = { - .dump = tcp_diag_dump, - .dump_one = tcp_diag_dump_one, - .idiag_get_info = tcp_diag_get_info, - .idiag_type = IPPROTO_TCP, + .owner = THIS_MODULE, + .dump = tcp_diag_dump, + .dump_one = tcp_diag_dump_one, + .idiag_get_info = tcp_diag_get_info, + .idiag_get_aux = tcp_diag_get_aux, + .idiag_type = IPPROTO_TCP, + .idiag_info_size = sizeof(struct tcp_info), +#ifdef CONFIG_INET_DIAG_DESTROY + .destroy = tcp_diag_destroy, +#endif }; static int __init tcp_diag_init(void) @@ -66,4 +684,5 @@ static void __exit tcp_diag_exit(void) module_init(tcp_diag_init); module_exit(tcp_diag_exit); MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("TCP socket monitoring via SOCK_DIAG"); MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */); 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