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af185d8c76
raw_diag_dump() can use rcu_read_lock() instead of read_lock() Now the hashinfo lock is only used from process context, in write mode only, we can convert it to a spinlock, and we do not need to block BH anymore. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20220620100509.3493504-1-eric.dumazet@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
264 lines
6.3 KiB
C
264 lines
6.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/module.h>
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#include <linux/inet_diag.h>
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#include <linux/sock_diag.h>
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#include <net/inet_sock.h>
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#include <net/raw.h>
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#include <net/rawv6.h>
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#ifdef pr_fmt
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# undef pr_fmt
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#endif
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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static struct raw_hashinfo *
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raw_get_hashinfo(const struct inet_diag_req_v2 *r)
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{
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if (r->sdiag_family == AF_INET) {
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return &raw_v4_hashinfo;
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#if IS_ENABLED(CONFIG_IPV6)
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} else if (r->sdiag_family == AF_INET6) {
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return &raw_v6_hashinfo;
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#endif
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} else {
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return ERR_PTR(-EINVAL);
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}
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}
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/*
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* Due to requirement of not breaking user API we can't simply
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* rename @pad field in inet_diag_req_v2 structure, instead
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* use helper to figure it out.
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*/
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static bool raw_lookup(struct net *net, struct sock *sk,
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const struct inet_diag_req_v2 *req)
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{
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struct inet_diag_req_raw *r = (void *)req;
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if (r->sdiag_family == AF_INET)
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return raw_v4_match(net, sk, r->sdiag_raw_protocol,
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r->id.idiag_dst[0],
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r->id.idiag_src[0],
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r->id.idiag_if, 0);
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#if IS_ENABLED(CONFIG_IPV6)
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else
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return raw_v6_match(net, sk, r->sdiag_raw_protocol,
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(const struct in6_addr *)r->id.idiag_src,
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(const struct in6_addr *)r->id.idiag_dst,
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r->id.idiag_if, 0);
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#endif
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return false;
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}
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static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)
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{
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struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
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struct hlist_nulls_head *hlist;
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struct hlist_nulls_node *hnode;
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struct sock *sk;
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int slot;
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if (IS_ERR(hashinfo))
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return ERR_CAST(hashinfo);
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rcu_read_lock();
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for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
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hlist = &hashinfo->ht[slot];
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sk_nulls_for_each(sk, hnode, hlist) {
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if (raw_lookup(net, sk, r)) {
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/*
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* Grab it and keep until we fill
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* diag message to be reported, so
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* caller should call sock_put then.
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*/
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if (refcount_inc_not_zero(&sk->sk_refcnt))
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goto out_unlock;
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}
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}
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}
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sk = ERR_PTR(-ENOENT);
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out_unlock:
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rcu_read_unlock();
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return sk;
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}
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static int raw_diag_dump_one(struct netlink_callback *cb,
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const struct inet_diag_req_v2 *r)
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{
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struct sk_buff *in_skb = cb->skb;
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struct sk_buff *rep;
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struct sock *sk;
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struct net *net;
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int err;
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net = sock_net(in_skb->sk);
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sk = raw_sock_get(net, r);
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if (IS_ERR(sk))
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return PTR_ERR(sk);
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rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
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inet_diag_msg_attrs_size() +
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nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,
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GFP_KERNEL);
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if (!rep) {
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sock_put(sk);
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return -ENOMEM;
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}
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err = inet_sk_diag_fill(sk, NULL, rep, cb, r, 0,
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netlink_net_capable(in_skb, CAP_NET_ADMIN));
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sock_put(sk);
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if (err < 0) {
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kfree_skb(rep);
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return err;
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}
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err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
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return err;
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}
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static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
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struct netlink_callback *cb,
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const struct inet_diag_req_v2 *r,
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struct nlattr *bc, bool net_admin)
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{
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if (!inet_diag_bc_sk(bc, sk))
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return 0;
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return inet_sk_diag_fill(sk, NULL, skb, cb, r, NLM_F_MULTI, net_admin);
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}
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static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
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const struct inet_diag_req_v2 *r)
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{
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bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
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struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
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struct net *net = sock_net(skb->sk);
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struct inet_diag_dump_data *cb_data;
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struct hlist_nulls_head *hlist;
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struct hlist_nulls_node *hnode;
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int num, s_num, slot, s_slot;
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struct sock *sk = NULL;
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struct nlattr *bc;
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if (IS_ERR(hashinfo))
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return;
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cb_data = cb->data;
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bc = cb_data->inet_diag_nla_bc;
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s_slot = cb->args[0];
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num = s_num = cb->args[1];
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rcu_read_lock();
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for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
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num = 0;
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hlist = &hashinfo->ht[slot];
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sk_nulls_for_each(sk, hnode, hlist) {
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struct inet_sock *inet = inet_sk(sk);
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if (!net_eq(sock_net(sk), net))
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continue;
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if (num < s_num)
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goto next;
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if (sk->sk_family != r->sdiag_family)
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goto next;
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if (r->id.idiag_sport != inet->inet_sport &&
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r->id.idiag_sport)
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goto next;
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if (r->id.idiag_dport != inet->inet_dport &&
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r->id.idiag_dport)
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goto next;
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if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
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goto out_unlock;
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next:
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num++;
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}
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}
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out_unlock:
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rcu_read_unlock();
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cb->args[0] = slot;
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cb->args[1] = num;
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}
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static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
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void *info)
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{
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r->idiag_rqueue = sk_rmem_alloc_get(sk);
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r->idiag_wqueue = sk_wmem_alloc_get(sk);
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}
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#ifdef CONFIG_INET_DIAG_DESTROY
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static int raw_diag_destroy(struct sk_buff *in_skb,
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const struct inet_diag_req_v2 *r)
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{
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struct net *net = sock_net(in_skb->sk);
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struct sock *sk;
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int err;
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sk = raw_sock_get(net, r);
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if (IS_ERR(sk))
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return PTR_ERR(sk);
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err = sock_diag_destroy(sk, ECONNABORTED);
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sock_put(sk);
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return err;
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}
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#endif
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static const struct inet_diag_handler raw_diag_handler = {
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.dump = raw_diag_dump,
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.dump_one = raw_diag_dump_one,
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.idiag_get_info = raw_diag_get_info,
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.idiag_type = IPPROTO_RAW,
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.idiag_info_size = 0,
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#ifdef CONFIG_INET_DIAG_DESTROY
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.destroy = raw_diag_destroy,
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#endif
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};
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static void __always_unused __check_inet_diag_req_raw(void)
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{
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/*
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* Make sure the two structures are identical,
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* except the @pad field.
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*/
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#define __offset_mismatch(m1, m2) \
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(offsetof(struct inet_diag_req_v2, m1) != \
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offsetof(struct inet_diag_req_raw, m2))
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BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
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sizeof(struct inet_diag_req_raw));
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BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
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BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
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BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
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BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
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BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
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BUILD_BUG_ON(__offset_mismatch(id, id));
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#undef __offset_mismatch
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}
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static int __init raw_diag_init(void)
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{
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return inet_diag_register(&raw_diag_handler);
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}
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static void __exit raw_diag_exit(void)
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{
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inet_diag_unregister(&raw_diag_handler);
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}
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module_init(raw_diag_init);
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module_exit(raw_diag_exit);
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
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MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
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