2 * Copyright (C) 2016 Netronome Systems, Inc.
4 * This software is dual licensed under the GNU General License Version 2,
5 * June 1991 as shown in the file COPYING in the top-level directory of this
6 * source tree or the BSD 2-Clause License provided below. You have the
7 * option to license this software under the complete terms of either license.
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12 * without modification, are permitted provided that the following
15 * 1. Redistributions of source code must retain the above
16 * copyright notice, this list of conditions and the following
19 * 2. Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
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22 * provided with the distribution.
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
34 #define pr_fmt(fmt) "NFP net bpf: " fmt
36 #include <linux/bpf.h>
37 #include <linux/bpf_verifier.h>
38 #include <linux/kernel.h>
39 #include <linux/pkt_cls.h>
43 /* Analyzer/verifier definitions */
44 struct nfp_bpf_analyzer_priv {
45 struct nfp_prog *prog;
46 struct nfp_insn_meta *meta;
49 static struct nfp_insn_meta *
50 nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
51 unsigned int insn_idx, unsigned int n_insns)
53 unsigned int forward, backward, i;
55 backward = meta->n - insn_idx;
56 forward = insn_idx - meta->n;
58 if (min(forward, backward) > n_insns - insn_idx - 1) {
59 backward = n_insns - insn_idx - 1;
60 meta = nfp_prog_last_meta(nfp_prog);
62 if (min(forward, backward) > insn_idx && backward > insn_idx) {
64 meta = nfp_prog_first_meta(nfp_prog);
67 if (forward < backward)
68 for (i = 0; i < forward; i++)
69 meta = nfp_meta_next(meta);
71 for (i = 0; i < backward; i++)
72 meta = nfp_meta_prev(meta);
78 nfp_bpf_check_exit(struct nfp_prog *nfp_prog,
79 const struct bpf_verifier_env *env)
81 const struct bpf_reg_state *reg0 = &env->cur_state.regs[0];
84 if (nfp_prog->act == NN_ACT_XDP)
87 if (!(reg0->type == SCALAR_VALUE && tnum_is_const(reg0->var_off))) {
90 tnum_strn(tn_buf, sizeof(tn_buf), reg0->var_off);
91 pr_info("unsupported exit state: %d, var_off: %s\n",
96 imm = reg0->var_off.value;
97 if (nfp_prog->act != NN_ACT_DIRECT && imm != 0 && (imm & ~0U) != ~0U) {
98 pr_info("unsupported exit state: %d, imm: %llx\n",
103 if (nfp_prog->act == NN_ACT_DIRECT && imm <= TC_ACT_REDIRECT &&
104 imm != TC_ACT_SHOT && imm != TC_ACT_STOLEN &&
105 imm != TC_ACT_QUEUED) {
106 pr_info("unsupported exit state: %d, imm: %llx\n",
115 nfp_bpf_check_ctx_ptr(struct nfp_prog *nfp_prog,
116 const struct bpf_verifier_env *env, u8 reg)
118 if (env->cur_state.regs[reg].type != PTR_TO_CTX)
125 nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx)
127 struct nfp_bpf_analyzer_priv *priv = env->analyzer_priv;
128 struct nfp_insn_meta *meta = priv->meta;
130 meta = nfp_bpf_goto_meta(priv->prog, meta, insn_idx, env->prog->len);
133 if (meta->insn.src_reg == BPF_REG_10 ||
134 meta->insn.dst_reg == BPF_REG_10) {
135 pr_err("stack not yet supported\n");
138 if (meta->insn.src_reg >= MAX_BPF_REG ||
139 meta->insn.dst_reg >= MAX_BPF_REG) {
140 pr_err("program uses extended registers - jit hardening?\n");
144 if (meta->insn.code == (BPF_JMP | BPF_EXIT))
145 return nfp_bpf_check_exit(priv->prog, env);
147 if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM))
148 return nfp_bpf_check_ctx_ptr(priv->prog, env,
150 if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM))
151 return nfp_bpf_check_ctx_ptr(priv->prog, env,
157 static const struct bpf_ext_analyzer_ops nfp_bpf_analyzer_ops = {
158 .insn_hook = nfp_verify_insn,
161 int nfp_prog_verify(struct nfp_prog *nfp_prog, struct bpf_prog *prog)
163 struct nfp_bpf_analyzer_priv *priv;
166 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
170 priv->prog = nfp_prog;
171 priv->meta = nfp_prog_first_meta(nfp_prog);
173 ret = bpf_analyzer(prog, &nfp_bpf_analyzer_ops, priv);