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/route.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'net/ipv6/route.c') 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 From 15172a46fa2796c1a1358a36babd31274716ed41 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 13 May 2020 11:02:19 -0700 Subject: bpf: net: Refactor bpf_iter target registration Currently bpf_iter_reg_target takes parameters from target and allocates memory to save them. This is really not necessary, esp. in the future we may grow information passed from targets to bpf_iter manager. The patch refactors the code so target reg_info becomes static and bpf_iter manager can just take a reference to it. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200513180219.2949605-1-yhs@fb.com --- net/ipv6/route.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'net/ipv6/route.c') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 25f6d3e619d0..6ad2fa51a23a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6397,17 +6397,17 @@ void __init ip6_route_init_special_entries(void) #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 const struct bpf_iter_reg ipv6_route_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), +}; + 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); + return bpf_iter_reg_target(&ipv6_route_reg_info); } static void bpf_iter_unregister(void) -- cgit v1.2.3 From ab2ee4fcb9d61fd57db70db694adbcf54662bd80 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 13 May 2020 11:02:20 -0700 Subject: bpf: Change func bpf_iter_unreg_target() signature Change func bpf_iter_unreg_target() parameter from target name to target reg_info, similar to bpf_iter_reg_target(). Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200513180220.2949737-1-yhs@fb.com --- net/ipv6/route.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv6/route.c') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 6ad2fa51a23a..22bf4e36c093 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6412,7 +6412,7 @@ static int __init bpf_iter_register(void) static void bpf_iter_unregister(void) { - bpf_iter_unreg_target("ipv6_route"); + bpf_iter_unreg_target(&ipv6_route_reg_info); } #endif #endif -- cgit v1.2.3 From 3c32cc1bceba8a1755dc35cd97516f6c67856844 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 13 May 2020 11:02:21 -0700 Subject: bpf: Enable bpf_iter targets registering ctx argument types Commit b121b341e598 ("bpf: Add PTR_TO_BTF_ID_OR_NULL support") adds a field btf_id_or_null_non0_off to bpf_prog->aux structure to indicate that the first ctx argument is PTR_TO_BTF_ID reg_type and all others are PTR_TO_BTF_ID_OR_NULL. This approach does not really scale if we have other different reg types in the future, e.g., a pointer to a buffer. This patch enables bpf_iter targets registering ctx argument reg types which may be different from the default one. For example, for pointers to structures, the default reg_type is PTR_TO_BTF_ID for tracing program. The target can register a particular pointer type as PTR_TO_BTF_ID_OR_NULL which can be used by the verifier to enforce accesses. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200513180221.2949882-1-yhs@fb.com --- net/ipv6/route.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net/ipv6/route.c') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 22bf4e36c093..22e56465f14d 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -6403,6 +6403,11 @@ static const struct bpf_iter_reg ipv6_route_reg_info = { .init_seq_private = bpf_iter_init_seq_net, .fini_seq_private = bpf_iter_fini_seq_net, .seq_priv_size = sizeof(struct ipv6_route_iter), + .ctx_arg_info_size = 1, + .ctx_arg_info = { + { offsetof(struct bpf_iter__ipv6_route, rt), + PTR_TO_BTF_ID_OR_NULL }, + }, }; static int __init bpf_iter_register(void) -- cgit v1.2.3