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authorWillem de Bruijn <willemb@google.com>2016-12-06 16:25:02 -0500
committerPablo Neira Ayuso <pablo@netfilter.org>2016-12-07 13:32:35 +0100
commit2c16d60332643e90d4fa244f4a706c454b8c7569 (patch)
treedde08e481c1bf3e50c501b7aca2fd88eefdfa6d7
parent5bad87348c70bb4d36e876523aade31e9dedd2fc (diff)
netfilter: xt_bpf: support ebpf
Add support for attaching an eBPF object by file descriptor. The iptables binary can be called with a path to an elf object or a pinned bpf object. Also pass the mode and path to the kernel to be able to return it later for iptables dump and save. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r--include/uapi/linux/netfilter/xt_bpf.h21
-rw-r--r--net/netfilter/xt_bpf.c96
2 files changed, 101 insertions, 16 deletions
diff --git a/include/uapi/linux/netfilter/xt_bpf.h b/include/uapi/linux/netfilter/xt_bpf.h
index 1fad2c27ac32..b97725af2ac0 100644
--- a/include/uapi/linux/netfilter/xt_bpf.h
+++ b/include/uapi/linux/netfilter/xt_bpf.h
@@ -2,9 +2,11 @@
#define _XT_BPF_H
#include <linux/filter.h>
+#include <linux/limits.h>
#include <linux/types.h>
#define XT_BPF_MAX_NUM_INSTR 64
+#define XT_BPF_PATH_MAX (XT_BPF_MAX_NUM_INSTR * sizeof(struct sock_filter))
struct bpf_prog;
@@ -16,4 +18,23 @@ struct xt_bpf_info {
struct bpf_prog *filter __attribute__((aligned(8)));
};
+enum xt_bpf_modes {
+ XT_BPF_MODE_BYTECODE,
+ XT_BPF_MODE_FD_PINNED,
+ XT_BPF_MODE_FD_ELF,
+};
+
+struct xt_bpf_info_v1 {
+ __u16 mode;
+ __u16 bpf_program_num_elem;
+ __s32 fd;
+ union {
+ struct sock_filter bpf_program[XT_BPF_MAX_NUM_INSTR];
+ char path[XT_BPF_PATH_MAX];
+ };
+
+ /* only used in the kernel */
+ struct bpf_prog *filter __attribute__((aligned(8)));
+};
+
#endif /*_XT_BPF_H */
diff --git a/net/netfilter/xt_bpf.c b/net/netfilter/xt_bpf.c
index dffee9d47ec4..2dedaa23ab0a 100644
--- a/net/netfilter/xt_bpf.c
+++ b/net/netfilter/xt_bpf.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/filter.h>
+#include <linux/bpf.h>
#include <linux/netfilter/xt_bpf.h>
#include <linux/netfilter/x_tables.h>
@@ -20,15 +21,15 @@ MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_bpf");
MODULE_ALIAS("ip6t_bpf");
-static int bpf_mt_check(const struct xt_mtchk_param *par)
+static int __bpf_mt_check_bytecode(struct sock_filter *insns, __u16 len,
+ struct bpf_prog **ret)
{
- struct xt_bpf_info *info = par->matchinfo;
struct sock_fprog_kern program;
- program.len = info->bpf_program_num_elem;
- program.filter = info->bpf_program;
+ program.len = len;
+ program.filter = insns;
- if (bpf_prog_create(&info->filter, &program)) {
+ if (bpf_prog_create(ret, &program)) {
pr_info("bpf: check failed: parse error\n");
return -EINVAL;
}
@@ -36,6 +37,42 @@ static int bpf_mt_check(const struct xt_mtchk_param *par)
return 0;
}
+static int __bpf_mt_check_fd(int fd, struct bpf_prog **ret)
+{
+ struct bpf_prog *prog;
+
+ prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ *ret = prog;
+ return 0;
+}
+
+static int bpf_mt_check(const struct xt_mtchk_param *par)
+{
+ struct xt_bpf_info *info = par->matchinfo;
+
+ return __bpf_mt_check_bytecode(info->bpf_program,
+ info->bpf_program_num_elem,
+ &info->filter);
+}
+
+static int bpf_mt_check_v1(const struct xt_mtchk_param *par)
+{
+ struct xt_bpf_info_v1 *info = par->matchinfo;
+
+ if (info->mode == XT_BPF_MODE_BYTECODE)
+ return __bpf_mt_check_bytecode(info->bpf_program,
+ info->bpf_program_num_elem,
+ &info->filter);
+ else if (info->mode == XT_BPF_MODE_FD_PINNED ||
+ info->mode == XT_BPF_MODE_FD_ELF)
+ return __bpf_mt_check_fd(info->fd, &info->filter);
+ else
+ return -EINVAL;
+}
+
static bool bpf_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_bpf_info *info = par->matchinfo;
@@ -43,31 +80,58 @@ static bool bpf_mt(const struct sk_buff *skb, struct xt_action_param *par)
return BPF_PROG_RUN(info->filter, skb);
}
+static bool bpf_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
+{
+ const struct xt_bpf_info_v1 *info = par->matchinfo;
+
+ return !!bpf_prog_run_save_cb(info->filter, (struct sk_buff *) skb);
+}
+
static void bpf_mt_destroy(const struct xt_mtdtor_param *par)
{
const struct xt_bpf_info *info = par->matchinfo;
+
+ bpf_prog_destroy(info->filter);
+}
+
+static void bpf_mt_destroy_v1(const struct xt_mtdtor_param *par)
+{
+ const struct xt_bpf_info_v1 *info = par->matchinfo;
+
bpf_prog_destroy(info->filter);
}
-static struct xt_match bpf_mt_reg __read_mostly = {
- .name = "bpf",
- .revision = 0,
- .family = NFPROTO_UNSPEC,
- .checkentry = bpf_mt_check,
- .match = bpf_mt,
- .destroy = bpf_mt_destroy,
- .matchsize = sizeof(struct xt_bpf_info),
- .me = THIS_MODULE,
+static struct xt_match bpf_mt_reg[] __read_mostly = {
+ {
+ .name = "bpf",
+ .revision = 0,
+ .family = NFPROTO_UNSPEC,
+ .checkentry = bpf_mt_check,
+ .match = bpf_mt,
+ .destroy = bpf_mt_destroy,
+ .matchsize = sizeof(struct xt_bpf_info),
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "bpf",
+ .revision = 1,
+ .family = NFPROTO_UNSPEC,
+ .checkentry = bpf_mt_check_v1,
+ .match = bpf_mt_v1,
+ .destroy = bpf_mt_destroy_v1,
+ .matchsize = sizeof(struct xt_bpf_info_v1),
+ .me = THIS_MODULE,
+ },
};
static int __init bpf_mt_init(void)
{
- return xt_register_match(&bpf_mt_reg);
+ return xt_register_matches(bpf_mt_reg, ARRAY_SIZE(bpf_mt_reg));
}
static void __exit bpf_mt_exit(void)
{
- xt_unregister_match(&bpf_mt_reg);
+ xt_unregister_matches(bpf_mt_reg, ARRAY_SIZE(bpf_mt_reg));
}
module_init(bpf_mt_init);