From 138d0be35b141e09f6b267c6ae4094318d4e4491 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Sat, 9 May 2020 10:59:10 -0700 Subject: 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 Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200509175910.2476329-1-yhs@fb.com --- net/ipv6/ip6_fib.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- net/ipv6/route.c | 37 +++++++++++++++++++++++++++++++ 2 files changed, 100 insertions(+), 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 46ed56719476..a1fcc0ca21af 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -2467,7 +2467,7 @@ void fib6_gc_cleanup(void) } #ifdef CONFIG_PROC_FS -static int ipv6_route_seq_show(struct seq_file *seq, void *v) +static int ipv6_route_native_seq_show(struct seq_file *seq, void *v) { struct fib6_info *rt = v; struct ipv6_route_iter *iter = seq->private; @@ -2625,7 +2625,7 @@ static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) return w->node && !(w->state == FWS_U && w->node == w->root); } -static void ipv6_route_seq_stop(struct seq_file *seq, void *v) +static void ipv6_route_native_seq_stop(struct seq_file *seq, void *v) __releases(RCU_BH) { struct net *net = seq_file_net(seq); @@ -2637,6 +2637,67 @@ static void ipv6_route_seq_stop(struct seq_file *seq, void *v) rcu_read_unlock_bh(); } +#if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL) +struct bpf_iter__ipv6_route { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct fib6_info *, rt); +}; + +static int ipv6_route_prog_seq_show(struct bpf_prog *prog, + struct bpf_iter_meta *meta, + void *v) +{ + struct bpf_iter__ipv6_route ctx; + + ctx.meta = meta; + ctx.rt = v; + return bpf_iter_run_prog(prog, &ctx); +} + +static int ipv6_route_seq_show(struct seq_file *seq, void *v) +{ + struct ipv6_route_iter *iter = seq->private; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + int ret; + + meta.seq = seq; + prog = bpf_iter_get_info(&meta, false); + if (!prog) + return ipv6_route_native_seq_show(seq, v); + + ret = ipv6_route_prog_seq_show(prog, &meta, v); + iter->w.leaf = NULL; + + return ret; +} + +static void ipv6_route_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)ipv6_route_prog_seq_show(prog, &meta, v); + } + + ipv6_route_native_seq_stop(seq, v); +} +#else +static int ipv6_route_seq_show(struct seq_file *seq, void *v) +{ + return ipv6_route_native_seq_show(seq, v); +} + +static void ipv6_route_seq_stop(struct seq_file *seq, void *v) +{ + ipv6_route_native_seq_stop(seq, v); +} +#endif + const struct seq_operations ipv6_route_seq_ops = { .start = ipv6_route_seq_start, .next = ipv6_route_seq_next, diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 3912aac7854d..25f6d3e619d0 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6393,6 +6393,30 @@ void __init ip6_route_init_special_entries(void) #endif } +#if IS_BUILTIN(CONFIG_IPV6) +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) +DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt) + +static int __init bpf_iter_register(void) +{ + struct bpf_iter_reg reg_info = { + .target = "ipv6_route", + .seq_ops = &ipv6_route_seq_ops, + .init_seq_private = bpf_iter_init_seq_net, + .fini_seq_private = bpf_iter_fini_seq_net, + .seq_priv_size = sizeof(struct ipv6_route_iter), + }; + + return bpf_iter_reg_target(®_info); +} + +static void bpf_iter_unregister(void) +{ + bpf_iter_unreg_target("ipv6_route"); +} +#endif +#endif + int __init ip6_route_init(void) { int ret; @@ -6455,6 +6479,14 @@ int __init ip6_route_init(void) if (ret) goto out_register_late_subsys; +#if IS_BUILTIN(CONFIG_IPV6) +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) + ret = bpf_iter_register(); + if (ret) + goto out_register_late_subsys; +#endif +#endif + for_each_possible_cpu(cpu) { struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); @@ -6487,6 +6519,11 @@ out_kmem_cache: void ip6_route_cleanup(void) { +#if IS_BUILTIN(CONFIG_IPV6) +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) + bpf_iter_unregister(); +#endif +#endif unregister_netdevice_notifier(&ip6_route_dev_notifier); unregister_pernet_subsys(&ip6_route_net_late_ops); fib6_rules_cleanup(); -- cgit v1.2.3