Commit 62001372 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Andrii Nakryiko
Browse files

bpf: tcp: seq_file: Remove bpf_seq_afinfo from tcp_iter_state 



A following patch will create a separate struct to store extra
bpf_iter state and it will embed the existing tcp_iter_state like this:
struct bpf_tcp_iter_state {
	struct tcp_iter_state state;
	/* More bpf_iter specific states here ... */
}

As a prep work, this patch removes the
"struct tcp_seq_afinfo *bpf_seq_afinfo" where its purpose is
to tell if it is iterating from bpf_iter instead of proc fs.
Currently, if "*bpf_seq_afinfo" is not NULL, it is iterating from
bpf_iter.  The kernel should not filter by the addr family and
leave this filtering decision to the bpf prog.

Instead of adding a "*bpf_seq_afinfo" pointer, this patch uses the
"seq->op == &bpf_iter_tcp_seq_ops" test to tell if it is iterating
from the bpf iter.

The bpf_iter_(init|fini)_tcp() is left here to prepare for
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/20210701200554.1034982-1-kafai@fb.com
parent ad2d6137

include/net/tcp.h

+0 −1
Original line number Diff line number Diff line
@@ -1959,7 +1959,6 @@ struct tcp_iter_state { 
	struct seq_net_private	p;

	enum tcp_seq_states	state;

	struct sock		*syn_wait_sk;

	struct tcp_seq_afinfo	*bpf_seq_afinfo;

	int			bucket, offset, sbucket, num;

	loff_t			last_pos;

};

net/ipv4/tcp_ipv4.c

+5 −20
Original line number Diff line number Diff line
@@ -2735,12 +2735,13 @@ static const struct seq_operations bpf_iter_tcp_seq_ops = { 
#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;

	const struct tcp_seq_afinfo *afinfo;



#ifdef CONFIG_BPF_SYSCALL

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

	if (afinfo)

	if (seq->op == &bpf_iter_tcp_seq_ops)

		return AF_UNSPEC;

#endif



	/* Iterated from proc fs */

	afinfo = PDE_DATA(file_inode(seq->file));
@@ -2998,27 +2999,11 @@ DEFINE_BPF_ITER_FUNC(tcp, struct bpf_iter_meta *meta, 


static int bpf_iter_init_tcp(void *priv_data, struct bpf_iter_aux_info *aux)

{

	struct tcp_iter_state *st = priv_data;

	struct tcp_seq_afinfo *afinfo;

	int ret;



	afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN);

	if (!afinfo)

		return -ENOMEM;



	afinfo->family = AF_UNSPEC;

	st->bpf_seq_afinfo = afinfo;

	ret = bpf_iter_init_seq_net(priv_data, aux);

	if (ret)

		kfree(afinfo);

	return ret;

	return bpf_iter_init_seq_net(priv_data, aux);

}



static void bpf_iter_fini_tcp(void *priv_data)

{

	struct tcp_iter_state *st = priv_data;



	kfree(st->bpf_seq_afinfo);

	bpf_iter_fini_seq_net(priv_data);

}