[PATCH v5 bpf-next 3/7] udp: seq_file: Helper function to match socket attributes

Aditi Ghag
2023-03-30T15:19:46Z

This is a preparatory commit to refactor code that matches socket
attributes in iterators to a helper function, and use it in the
proc fs iterator.

Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com>
---
net/ipv4/udp.c | 35 ++++++++++++++++++++++++++++-------
1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c574c8c17ec9..cead4acb64c6 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2983,6 +2983,8 @@ EXPORT_SYMBOL(udp_prot);
/* ------------------------------------------------------------------------ */
#ifdef CONFIG_PROC_FS

+static inline bool seq_sk_match(struct seq_file *seq, const struct sock *sk);
+
static struct udp_table *udp_get_table_afinfo(struct udp_seq_afinfo *afinfo,
struct net *net)
{
@@ -3010,10 +3012,7 @@ static struct sock *udp_get_first(struct seq_file *seq, int start)

spin_lock_bh(&hslot->lock);
sk_for_each(sk, &hslot->head) {
- if (!net_eq(sock_net(sk), net))
- continue;
- if (afinfo->family == AF_UNSPEC ||
- sk->sk_family == afinfo->family)
+ if (seq_sk_match(seq, sk))
goto found;
}
spin_unlock_bh(&hslot->lock);
@@ -3034,9 +3033,7 @@ static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)

do {
sk = sk_next(sk);
- } while (sk && (!net_eq(sock_net(sk), net) ||
- (afinfo->family != AF_UNSPEC &&
- sk->sk_family != afinfo->family)));
+ } while (sk && !seq_sk_match(seq, sk));

if (!sk) {
udptable = udp_get_table_afinfo(afinfo, net);
@@ -3143,6 +3140,17 @@ struct bpf_iter__udp {
int bucket __aligned(8);
};

+static unsigned short seq_file_family(const struct seq_file *seq);
+
+static inline 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)));
+}
+
static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
struct udp_sock *udp_sk, uid_t uid, int bucket)
{
@@ -3194,6 +3202,19 @@ static const struct seq_operations bpf_iter_udp_seq_ops = {
.stop = bpf_iter_udp_seq_stop,
.show = bpf_iter_udp_seq_show,
};
+
+static unsigned short seq_file_family(const struct seq_file *seq)
+{
+ const struct udp_seq_afinfo *afinfo;
+
+ /* BPF iterator: bpf programs to filter sockets. */
+ if (seq->op == &bpf_iter_udp_seq_ops)
+ return AF_UNSPEC;
+
+ /* Proc fs iterator */
+ afinfo = pde_data(file_inode(seq->file));
+ return afinfo->family;
+}
#endif

const struct seq_operations udp_seq_ops = {
--
2.34.1