From 62001372c2b6cdf2346afb2cf94ed3d950eee64c Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Thu, 1 Jul 2021 13:05:54 -0700 Subject: [PATCH] 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: Martin KaFai Lau Signed-off-by: Andrii Nakryiko Reviewed-by: Eric Dumazet Acked-by: Kuniyuki Iwashima Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210701200554.1034982-1-kafai@fb.com --- include/net/tcp.h | 1 - net/ipv4/tcp_ipv4.c | 25 +++++-------------------- 2 files changed, 5 insertions(+), 21 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 17df9b0..ba30341 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -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; }; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index f2583c4..665f99d 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -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); } -- 2.7.4