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authorKuniyuki Iwashima <kuniyu@amazon.co.jp>2021-08-14 10:57:15 +0900
committerAndrii Nakryiko <andrii@kernel.org>2021-08-15 00:13:32 -0700
commit2c860a43dd77f969bb959336a2f743d7103a8f63 (patch)
tree86ef0c1115eda01220a5ffa8053e48a1394a43fc
parentd1bf7c4d5deae6685a42463f4d29418fd2515d05 (diff)
bpf: af_unix: Implement BPF iterator for UNIX domain socket.
This patch implements the BPF iterator for the UNIX domain socket. Currently, the batch optimisation introduced for the TCP iterator in the commit 04c7820b776f ("bpf: tcp: Bpf iter batching and lock_sock") is not used for the UNIX domain socket. It will require replacing the big lock for the hash table with small locks for each hash list not to block other processes. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210814015718.42704-2-kuniyu@amazon.co.jp
-rw-r--r--include/linux/btf_ids.h3
-rw-r--r--net/unix/af_unix.c93
2 files changed, 95 insertions, 1 deletions
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index 57890b357f85..bed4b9964581 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -172,7 +172,8 @@ extern struct btf_id_set name;
BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock) \
BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock) \
- BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock)
+ BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock) \
+ BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock)
enum {
#define BTF_SOCK_TYPE(name, str) name,
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 1c2224f05b51..bad8f19174e3 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -113,6 +113,7 @@
#include <linux/security.h>
#include <linux/freezer.h>
#include <linux/file.h>
+#include <linux/btf_ids.h>
#include "scm.h"
@@ -3143,6 +3144,64 @@ static const struct seq_operations unix_seq_ops = {
.stop = unix_seq_stop,
.show = unix_seq_show,
};
+
+#if IS_BUILTIN(CONFIG_UNIX) && defined(CONFIG_BPF_SYSCALL)
+struct bpf_iter__unix {
+ __bpf_md_ptr(struct bpf_iter_meta *, meta);
+ __bpf_md_ptr(struct unix_sock *, unix_sk);
+ uid_t uid __aligned(8);
+};
+
+static int unix_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
+ struct unix_sock *unix_sk, uid_t uid)
+{
+ struct bpf_iter__unix ctx;
+
+ meta->seq_num--; /* skip SEQ_START_TOKEN */
+ ctx.meta = meta;
+ ctx.unix_sk = unix_sk;
+ ctx.uid = uid;
+ return bpf_iter_run_prog(prog, &ctx);
+}
+
+static int bpf_iter_unix_seq_show(struct seq_file *seq, void *v)
+{
+ struct bpf_iter_meta meta;
+ struct bpf_prog *prog;
+ struct sock *sk = v;
+ uid_t uid;
+
+ if (v == SEQ_START_TOKEN)
+ return 0;
+
+ uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
+ meta.seq = seq;
+ prog = bpf_iter_get_info(&meta, false);
+ return unix_prog_seq_show(prog, &meta, v, uid);
+}
+
+static void bpf_iter_unix_seq_stop(struct seq_file *seq, void *v)
+{
+ struct bpf_iter_meta meta;
+ struct bpf_prog *prog;
+
+ if (!v) {
+ meta.seq = seq;
+ prog = bpf_iter_get_info(&meta, true);
+ if (prog)
+ (void)unix_prog_seq_show(prog, &meta, v, 0);
+ }
+
+ unix_seq_stop(seq, v);
+}
+
+static const struct seq_operations bpf_iter_unix_seq_ops = {
+ .start = unix_seq_start,
+ .next = unix_seq_next,
+ .stop = bpf_iter_unix_seq_stop,
+ .show = bpf_iter_unix_seq_show,
+};
+#endif
#endif
static const struct net_proto_family unix_family_ops = {
@@ -3183,6 +3242,35 @@ static struct pernet_operations unix_net_ops = {
.exit = unix_net_exit,
};
+#if IS_BUILTIN(CONFIG_UNIX) && defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
+DEFINE_BPF_ITER_FUNC(unix, struct bpf_iter_meta *meta,
+ struct unix_sock *unix_sk, uid_t uid)
+
+static const struct bpf_iter_seq_info unix_seq_info = {
+ .seq_ops = &bpf_iter_unix_seq_ops,
+ .init_seq_private = bpf_iter_init_seq_net,
+ .fini_seq_private = bpf_iter_fini_seq_net,
+ .seq_priv_size = sizeof(struct seq_net_private),
+};
+
+static struct bpf_iter_reg unix_reg_info = {
+ .target = "unix",
+ .ctx_arg_info_size = 1,
+ .ctx_arg_info = {
+ { offsetof(struct bpf_iter__unix, unix_sk),
+ PTR_TO_BTF_ID_OR_NULL },
+ },
+ .seq_info = &unix_seq_info,
+};
+
+static void __init bpf_iter_register(void)
+{
+ unix_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UNIX];
+ if (bpf_iter_reg_target(&unix_reg_info))
+ pr_warn("Warning: could not register bpf iterator unix\n");
+}
+#endif
+
static int __init af_unix_init(void)
{
int rc = -1;
@@ -3198,6 +3286,11 @@ static int __init af_unix_init(void)
sock_register(&unix_family_ops);
register_pernet_subsys(&unix_net_ops);
unix_bpf_build_proto();
+
+#if IS_BUILTIN(CONFIG_UNIX) && defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
+ bpf_iter_register();
+#endif
+
out:
return rc;
}