xref: /dpdk/lib/bpf/bpf_load.c (revision daa02b5cddbb8e11b31d41e2bf7bb1ae64dcae2f)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2018 Intel Corporation
3  */
4 
5 #include <stdarg.h>
6 #include <stdio.h>
7 #include <string.h>
8 #include <errno.h>
9 #include <stdint.h>
10 #include <unistd.h>
11 #include <inttypes.h>
12 
13 #include <rte_common.h>
14 #include <rte_log.h>
15 #include <rte_debug.h>
16 #include <rte_memory.h>
17 #include <rte_eal.h>
18 #include <rte_byteorder.h>
19 #include <rte_errno.h>
20 
21 #include "bpf_impl.h"
22 
23 static struct rte_bpf *
24 bpf_load(const struct rte_bpf_prm *prm)
25 {
26 	uint8_t *buf;
27 	struct rte_bpf *bpf;
28 	size_t sz, bsz, insz, xsz;
29 
30 	xsz =  prm->nb_xsym * sizeof(prm->xsym[0]);
31 	insz = prm->nb_ins * sizeof(prm->ins[0]);
32 	bsz = sizeof(bpf[0]);
33 	sz = insz + xsz + bsz;
34 
35 	buf = mmap(NULL, sz, PROT_READ | PROT_WRITE,
36 		MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
37 	if (buf == MAP_FAILED)
38 		return NULL;
39 
40 	bpf = (void *)buf;
41 	bpf->sz = sz;
42 
43 	memcpy(&bpf->prm, prm, sizeof(bpf->prm));
44 
45 	memcpy(buf + bsz, prm->xsym, xsz);
46 	memcpy(buf + bsz + xsz, prm->ins, insz);
47 
48 	bpf->prm.xsym = (void *)(buf + bsz);
49 	bpf->prm.ins = (void *)(buf + bsz + xsz);
50 
51 	return bpf;
52 }
53 
54 /*
55  * Check that user provided external symbol.
56  */
57 static int
58 bpf_check_xsym(const struct rte_bpf_xsym *xsym)
59 {
60 	uint32_t i;
61 
62 	if (xsym->name == NULL)
63 		return -EINVAL;
64 
65 	if (xsym->type == RTE_BPF_XTYPE_VAR) {
66 		if (xsym->var.desc.type == RTE_BPF_ARG_UNDEF)
67 			return -EINVAL;
68 	} else if (xsym->type == RTE_BPF_XTYPE_FUNC) {
69 
70 		if (xsym->func.nb_args > EBPF_FUNC_MAX_ARGS)
71 			return -EINVAL;
72 
73 		/* check function arguments */
74 		for (i = 0; i != xsym->func.nb_args; i++) {
75 			if (xsym->func.args[i].type == RTE_BPF_ARG_UNDEF)
76 				return -EINVAL;
77 		}
78 
79 		/* check return value info */
80 		if (xsym->func.ret.type != RTE_BPF_ARG_UNDEF &&
81 				xsym->func.ret.size == 0)
82 			return -EINVAL;
83 	} else
84 		return -EINVAL;
85 
86 	return 0;
87 }
88 
89 struct rte_bpf *
90 rte_bpf_load(const struct rte_bpf_prm *prm)
91 {
92 	struct rte_bpf *bpf;
93 	int32_t rc;
94 	uint32_t i;
95 
96 	if (prm == NULL || prm->ins == NULL ||
97 			(prm->nb_xsym != 0 && prm->xsym == NULL)) {
98 		rte_errno = EINVAL;
99 		return NULL;
100 	}
101 
102 	rc = 0;
103 	for (i = 0; i != prm->nb_xsym && rc == 0; i++)
104 		rc = bpf_check_xsym(prm->xsym + i);
105 
106 	if (rc != 0) {
107 		rte_errno = -rc;
108 		RTE_BPF_LOG(ERR, "%s: %d-th xsym is invalid\n", __func__, i);
109 		return NULL;
110 	}
111 
112 	bpf = bpf_load(prm);
113 	if (bpf == NULL) {
114 		rte_errno = ENOMEM;
115 		return NULL;
116 	}
117 
118 	rc = bpf_validate(bpf);
119 	if (rc == 0) {
120 		bpf_jit(bpf);
121 		if (mprotect(bpf, bpf->sz, PROT_READ) != 0)
122 			rc = -ENOMEM;
123 	}
124 
125 	if (rc != 0) {
126 		rte_bpf_destroy(bpf);
127 		rte_errno = -rc;
128 		return NULL;
129 	}
130 
131 	return bpf;
132 }
133 
134 #ifndef RTE_LIBRTE_BPF_ELF
135 struct rte_bpf *
136 rte_bpf_elf_load(const struct rte_bpf_prm *prm, const char *fname,
137 	const char *sname)
138 {
139 	if (prm == NULL || fname == NULL || sname == NULL) {
140 		rte_errno = EINVAL;
141 		return NULL;
142 	}
143 
144 	RTE_BPF_LOG(ERR, "%s() is not supported with current config\n"
145 		"rebuild with libelf installed\n",
146 		__func__);
147 	rte_errno = ENOTSUP;
148 	return NULL;
149 }
150 #endif
151