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authorYonghong Song <yhs@fb.com>2020-05-09 20:59:10 +0300
committerAlexei Starovoitov <ast@kernel.org>2020-05-10 03:05:26 +0300
commit138d0be35b141e09f6b267c6ae4094318d4e4491 (patch)
tree76a12178ba458cf724b25df390e3d66ccd5ecfbf /net/netlink
parent6086d29def80edd78f9832ea6eafa74e3818f6a7 (diff)
downloadlinux-138d0be35b141e09f6b267c6ae4094318d4e4491.tar.xz
net: bpf: Add netlink and ipv6_route bpf_iter targets
This patch added netlink and ipv6_route targets, using the same seq_ops (except show() and minor changes for stop()) for /proc/net/{netlink,ipv6_route}. The net namespace for these targets are the current net namespace at file open stage, similar to /proc/net/{netlink,ipv6_route} reference counting the net namespace at seq_file open stage. Since module is not supported for now, ipv6_route is supported only if the IPV6 is built-in, i.e., not compiled as a module. The restriction can be lifted once module is properly supported for bpf_iter. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175910.2476329-1-yhs@fb.com
Diffstat (limited to 'net/netlink')
-rw-r--r--net/netlink/af_netlink.c87
1 files changed, 85 insertions, 2 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 5ded01ca8b20..33cda9baa979 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2596,7 +2596,7 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
return __netlink_seq_next(seq);
}
-static void netlink_seq_stop(struct seq_file *seq, void *v)
+static void netlink_native_seq_stop(struct seq_file *seq, void *v)
{
struct nl_seq_iter *iter = seq->private;
@@ -2607,7 +2607,7 @@ static void netlink_seq_stop(struct seq_file *seq, void *v)
}
-static int netlink_seq_show(struct seq_file *seq, void *v)
+static int netlink_native_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN) {
seq_puts(seq,
@@ -2634,6 +2634,68 @@ static int netlink_seq_show(struct seq_file *seq, void *v)
return 0;
}
+#ifdef CONFIG_BPF_SYSCALL
+struct bpf_iter__netlink {
+ __bpf_md_ptr(struct bpf_iter_meta *, meta);
+ __bpf_md_ptr(struct netlink_sock *, sk);
+};
+
+DEFINE_BPF_ITER_FUNC(netlink, struct bpf_iter_meta *meta, struct netlink_sock *sk)
+
+static int netlink_prog_seq_show(struct bpf_prog *prog,
+ struct bpf_iter_meta *meta,
+ void *v)
+{
+ struct bpf_iter__netlink ctx;
+
+ meta->seq_num--; /* skip SEQ_START_TOKEN */
+ ctx.meta = meta;
+ ctx.sk = nlk_sk((struct sock *)v);
+ return bpf_iter_run_prog(prog, &ctx);
+}
+
+static int netlink_seq_show(struct seq_file *seq, void *v)
+{
+ struct bpf_iter_meta meta;
+ struct bpf_prog *prog;
+
+ meta.seq = seq;
+ prog = bpf_iter_get_info(&meta, false);
+ if (!prog)
+ return netlink_native_seq_show(seq, v);
+
+ if (v != SEQ_START_TOKEN)
+ return netlink_prog_seq_show(prog, &meta, v);
+
+ return 0;
+}
+
+static void netlink_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)netlink_prog_seq_show(prog, &meta, v);
+ }
+
+ netlink_native_seq_stop(seq, v);
+}
+#else
+static int netlink_seq_show(struct seq_file *seq, void *v)
+{
+ return netlink_native_seq_show(seq, v);
+}
+
+static void netlink_seq_stop(struct seq_file *seq, void *v)
+{
+ netlink_native_seq_stop(seq, v);
+}
+#endif
+
static const struct seq_operations netlink_seq_ops = {
.start = netlink_seq_start,
.next = netlink_seq_next,
@@ -2740,6 +2802,21 @@ static const struct rhashtable_params netlink_rhashtable_params = {
.automatic_shrinking = true,
};
+#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
+static int __init bpf_iter_register(void)
+{
+ struct bpf_iter_reg reg_info = {
+ .target = "netlink",
+ .seq_ops = &netlink_seq_ops,
+ .init_seq_private = bpf_iter_init_seq_net,
+ .fini_seq_private = bpf_iter_fini_seq_net,
+ .seq_priv_size = sizeof(struct nl_seq_iter),
+ };
+
+ return bpf_iter_reg_target(&reg_info);
+}
+#endif
+
static int __init netlink_proto_init(void)
{
int i;
@@ -2748,6 +2825,12 @@ static int __init netlink_proto_init(void)
if (err != 0)
goto out;
+#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
+ err = bpf_iter_register();
+ if (err)
+ goto out;
+#endif
+
BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof_field(struct sk_buff, cb));
nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);