Commit ad2d6137 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Andrii Nakryiko
Browse files

tcp: seq_file: Refactor net and family matching 



This patch refactors the net and family matching into
two new helpers, seq_sk_match() and seq_file_family().

seq_file_family() is in the later part of the file to prepare
the change of a following patch.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarKuniyuki Iwashima <kuniyu@amazon.co.jp>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210701200548.1034629-1-kafai@fb.com
parent 525e2f9f

net/ipv4/tcp_ipv4.c

+30 −38
Original line number Diff line number Diff line
@@ -2277,6 +2277,17 @@ EXPORT_SYMBOL(tcp_v4_destroy_sock); 
#ifdef CONFIG_PROC_FS

/* Proc filesystem TCP sock list dumping. */



static unsigned short seq_file_family(const struct seq_file *seq);



static bool seq_sk_match(struct seq_file *seq, const struct sock *sk)

{

	unsigned short family = seq_file_family(seq);



	/* AF_UNSPEC is used as a match all */

	return ((family == AF_UNSPEC || family == sk->sk_family) &&

		net_eq(sock_net(sk), seq_file_net(seq)));

}



/*

 * Get next listener socket follow cur.  If cur is NULL, get first socket

 * starting from bucket given in st->bucket; when st->bucket is zero the
@@ -2284,18 +2295,11 @@ EXPORT_SYMBOL(tcp_v4_destroy_sock); 
 */

static void *listening_get_next(struct seq_file *seq, void *cur)

{

	struct tcp_seq_afinfo *afinfo;

	struct tcp_iter_state *st = seq->private;

	struct net *net = seq_file_net(seq);

	struct inet_listen_hashbucket *ilb;

	struct hlist_nulls_node *node;

	struct sock *sk = cur;



	if (st->bpf_seq_afinfo)

		afinfo = st->bpf_seq_afinfo;

	else

		afinfo = PDE_DATA(file_inode(seq->file));



	if (!sk) {

get_head:

		ilb = &tcp_hashinfo.listening_hash[st->bucket];
@@ -2311,10 +2315,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur) 
	sk = sk_nulls_next(sk);

get_sk:

	sk_nulls_for_each_from(sk, node) {

		if (!net_eq(sock_net(sk), net))

			continue;

		if (afinfo->family == AF_UNSPEC ||

		    sk->sk_family == afinfo->family)

		if (seq_sk_match(seq, sk))

			return sk;

	}

	spin_unlock(&ilb->lock);
@@ -2351,15 +2352,7 @@ static inline bool empty_bucket(const struct tcp_iter_state *st) 
 */

static void *established_get_first(struct seq_file *seq)

{

	struct tcp_seq_afinfo *afinfo;

	struct tcp_iter_state *st = seq->private;

	struct net *net = seq_file_net(seq);

	void *rc = NULL;



	if (st->bpf_seq_afinfo)

		afinfo = st->bpf_seq_afinfo;

	else

		afinfo = PDE_DATA(file_inode(seq->file));



	st->offset = 0;

	for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
@@ -2373,32 +2366,20 @@ static void *established_get_first(struct seq_file *seq) 


		spin_lock_bh(lock);

		sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {

			if ((afinfo->family != AF_UNSPEC &&

			     sk->sk_family != afinfo->family) ||

			    !net_eq(sock_net(sk), net)) {

				continue;

			}

			rc = sk;

			goto out;

			if (seq_sk_match(seq, sk))

				return sk;

		}

		spin_unlock_bh(lock);

	}

out:

	return rc;



	return NULL;

}



static void *established_get_next(struct seq_file *seq, void *cur)

{

	struct tcp_seq_afinfo *afinfo;

	struct sock *sk = cur;

	struct hlist_nulls_node *node;

	struct tcp_iter_state *st = seq->private;

	struct net *net = seq_file_net(seq);



	if (st->bpf_seq_afinfo)

		afinfo = st->bpf_seq_afinfo;

	else

		afinfo = PDE_DATA(file_inode(seq->file));



	++st->num;

	++st->offset;
@@ -2406,9 +2387,7 @@ static void *established_get_next(struct seq_file *seq, void *cur) 
	sk = sk_nulls_next(sk);



	sk_nulls_for_each_from(sk, node) {

		if ((afinfo->family == AF_UNSPEC ||

		     sk->sk_family == afinfo->family) &&

		    net_eq(sock_net(sk), net))

		if (seq_sk_match(seq, sk))

			return sk;

	}
@@ -2754,6 +2733,19 @@ static const struct seq_operations bpf_iter_tcp_seq_ops = { 
	.stop		= bpf_iter_tcp_seq_stop,

};

#endif

static unsigned short seq_file_family(const struct seq_file *seq)

{

	const struct tcp_iter_state *st = seq->private;

	const struct tcp_seq_afinfo *afinfo = st->bpf_seq_afinfo;



	/* Iterated from bpf_iter.  Let the bpf prog to filter instead. */

	if (afinfo)

		return AF_UNSPEC;



	/* Iterated from proc fs */

	afinfo = PDE_DATA(file_inode(seq->file));

	return afinfo->family;

}



static const struct seq_operations tcp4_seq_ops = {

	.show		= tcp4_seq_show,