1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 #include <stdio.h>
4 #include <errno.h>
5 #include <bpf/btf.h>
6 #include <bpf/libbpf.h>
7 #include "test_progs.h"
8 
9 static const char * const btf_kind_str_mapping[] = {
10 	[BTF_KIND_UNKN]		= "UNKNOWN",
11 	[BTF_KIND_INT]		= "INT",
12 	[BTF_KIND_PTR]		= "PTR",
13 	[BTF_KIND_ARRAY]	= "ARRAY",
14 	[BTF_KIND_STRUCT]	= "STRUCT",
15 	[BTF_KIND_UNION]	= "UNION",
16 	[BTF_KIND_ENUM]		= "ENUM",
17 	[BTF_KIND_FWD]		= "FWD",
18 	[BTF_KIND_TYPEDEF]	= "TYPEDEF",
19 	[BTF_KIND_VOLATILE]	= "VOLATILE",
20 	[BTF_KIND_CONST]	= "CONST",
21 	[BTF_KIND_RESTRICT]	= "RESTRICT",
22 	[BTF_KIND_FUNC]		= "FUNC",
23 	[BTF_KIND_FUNC_PROTO]	= "FUNC_PROTO",
24 	[BTF_KIND_VAR]		= "VAR",
25 	[BTF_KIND_DATASEC]	= "DATASEC",
26 	[BTF_KIND_FLOAT]	= "FLOAT",
27 	[BTF_KIND_DECL_TAG]	= "DECL_TAG",
28 	[BTF_KIND_TYPE_TAG]	= "TYPE_TAG",
29 };
30 
31 static const char *btf_kind_str(__u16 kind)
32 {
33 	if (kind > BTF_KIND_TYPE_TAG)
34 		return "UNKNOWN";
35 	return btf_kind_str_mapping[kind];
36 }
37 
38 static const char *btf_int_enc_str(__u8 encoding)
39 {
40 	switch (encoding) {
41 	case 0:
42 		return "(none)";
43 	case BTF_INT_SIGNED:
44 		return "SIGNED";
45 	case BTF_INT_CHAR:
46 		return "CHAR";
47 	case BTF_INT_BOOL:
48 		return "BOOL";
49 	default:
50 		return "UNKN";
51 	}
52 }
53 
54 static const char *btf_var_linkage_str(__u32 linkage)
55 {
56 	switch (linkage) {
57 	case BTF_VAR_STATIC:
58 		return "static";
59 	case BTF_VAR_GLOBAL_ALLOCATED:
60 		return "global-alloc";
61 	default:
62 		return "(unknown)";
63 	}
64 }
65 
66 static const char *btf_func_linkage_str(const struct btf_type *t)
67 {
68 	switch (btf_vlen(t)) {
69 	case BTF_FUNC_STATIC:
70 		return "static";
71 	case BTF_FUNC_GLOBAL:
72 		return "global";
73 	case BTF_FUNC_EXTERN:
74 		return "extern";
75 	default:
76 		return "(unknown)";
77 	}
78 }
79 
80 static const char *btf_str(const struct btf *btf, __u32 off)
81 {
82 	if (!off)
83 		return "(anon)";
84 	return btf__str_by_offset(btf, off) ?: "(invalid)";
85 }
86 
87 int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id)
88 {
89 	const struct btf_type *t;
90 	int kind, i;
91 	__u32 vlen;
92 
93 	t = btf__type_by_id(btf, id);
94 	if (!t)
95 		return -EINVAL;
96 
97 	vlen = btf_vlen(t);
98 	kind = btf_kind(t);
99 
100 	fprintf(out, "[%u] %s '%s'", id, btf_kind_str(kind), btf_str(btf, t->name_off));
101 
102 	switch (kind) {
103 	case BTF_KIND_INT:
104 		fprintf(out, " size=%u bits_offset=%u nr_bits=%u encoding=%s",
105 			t->size, btf_int_offset(t), btf_int_bits(t),
106 			btf_int_enc_str(btf_int_encoding(t)));
107 		break;
108 	case BTF_KIND_PTR:
109 	case BTF_KIND_CONST:
110 	case BTF_KIND_VOLATILE:
111 	case BTF_KIND_RESTRICT:
112 	case BTF_KIND_TYPEDEF:
113 	case BTF_KIND_TYPE_TAG:
114 		fprintf(out, " type_id=%u", t->type);
115 		break;
116 	case BTF_KIND_ARRAY: {
117 		const struct btf_array *arr = btf_array(t);
118 
119 		fprintf(out, " type_id=%u index_type_id=%u nr_elems=%u",
120 			arr->type, arr->index_type, arr->nelems);
121 		break;
122 	}
123 	case BTF_KIND_STRUCT:
124 	case BTF_KIND_UNION: {
125 		const struct btf_member *m = btf_members(t);
126 
127 		fprintf(out, " size=%u vlen=%u", t->size, vlen);
128 		for (i = 0; i < vlen; i++, m++) {
129 			__u32 bit_off, bit_sz;
130 
131 			bit_off = btf_member_bit_offset(t, i);
132 			bit_sz = btf_member_bitfield_size(t, i);
133 			fprintf(out, "\n\t'%s' type_id=%u bits_offset=%u",
134 				btf_str(btf, m->name_off), m->type, bit_off);
135 			if (bit_sz)
136 				fprintf(out, " bitfield_size=%u", bit_sz);
137 		}
138 		break;
139 	}
140 	case BTF_KIND_ENUM: {
141 		const struct btf_enum *v = btf_enum(t);
142 
143 		fprintf(out, " size=%u vlen=%u", t->size, vlen);
144 		for (i = 0; i < vlen; i++, v++) {
145 			fprintf(out, "\n\t'%s' val=%u",
146 				btf_str(btf, v->name_off), v->val);
147 		}
148 		break;
149 	}
150 	case BTF_KIND_FWD:
151 		fprintf(out, " fwd_kind=%s", btf_kflag(t) ? "union" : "struct");
152 		break;
153 	case BTF_KIND_FUNC:
154 		fprintf(out, " type_id=%u linkage=%s", t->type, btf_func_linkage_str(t));
155 		break;
156 	case BTF_KIND_FUNC_PROTO: {
157 		const struct btf_param *p = btf_params(t);
158 
159 		fprintf(out, " ret_type_id=%u vlen=%u", t->type, vlen);
160 		for (i = 0; i < vlen; i++, p++) {
161 			fprintf(out, "\n\t'%s' type_id=%u",
162 				btf_str(btf, p->name_off), p->type);
163 		}
164 		break;
165 	}
166 	case BTF_KIND_VAR:
167 		fprintf(out, " type_id=%u, linkage=%s",
168 			t->type, btf_var_linkage_str(btf_var(t)->linkage));
169 		break;
170 	case BTF_KIND_DATASEC: {
171 		const struct btf_var_secinfo *v = btf_var_secinfos(t);
172 
173 		fprintf(out, " size=%u vlen=%u", t->size, vlen);
174 		for (i = 0; i < vlen; i++, v++) {
175 			fprintf(out, "\n\ttype_id=%u offset=%u size=%u",
176 				v->type, v->offset, v->size);
177 		}
178 		break;
179 	}
180 	case BTF_KIND_FLOAT:
181 		fprintf(out, " size=%u", t->size);
182 		break;
183 	case BTF_KIND_DECL_TAG:
184 		fprintf(out, " type_id=%u component_idx=%d",
185 			t->type, btf_decl_tag(t)->component_idx);
186 		break;
187 	default:
188 		break;
189 	}
190 
191 	return 0;
192 }
193 
194 /* Print raw BTF type dump into a local buffer and return string pointer back.
195  * Buffer *will* be overwritten by subsequent btf_type_raw_dump() calls
196  */
197 const char *btf_type_raw_dump(const struct btf *btf, int type_id)
198 {
199 	static char buf[16 * 1024];
200 	FILE *buf_file;
201 
202 	buf_file = fmemopen(buf, sizeof(buf) - 1, "w");
203 	if (!buf_file) {
204 		fprintf(stderr, "Failed to open memstream: %d\n", errno);
205 		return NULL;
206 	}
207 
208 	fprintf_btf_type_raw(buf_file, btf, type_id);
209 	fflush(buf_file);
210 	fclose(buf_file);
211 
212 	return buf;
213 }
214 
215 int btf_validate_raw(struct btf *btf, int nr_types, const char *exp_types[])
216 {
217 	int i;
218 	bool ok = true;
219 
220 	ASSERT_EQ(btf__type_cnt(btf) - 1, nr_types, "btf_nr_types");
221 
222 	for (i = 1; i <= nr_types; i++) {
223 		if (!ASSERT_STREQ(btf_type_raw_dump(btf, i), exp_types[i - 1], "raw_dump"))
224 			ok = false;
225 	}
226 
227 	return ok;
228 }
229 
230 static void btf_dump_printf(void *ctx, const char *fmt, va_list args)
231 {
232 	vfprintf(ctx, fmt, args);
233 }
234 
235 /* Print BTF-to-C dump into a local buffer and return string pointer back.
236  * Buffer *will* be overwritten by subsequent btf_type_raw_dump() calls
237  */
238 const char *btf_type_c_dump(const struct btf *btf)
239 {
240 	static char buf[16 * 1024];
241 	FILE *buf_file;
242 	struct btf_dump *d = NULL;
243 	int err, i;
244 
245 	buf_file = fmemopen(buf, sizeof(buf) - 1, "w");
246 	if (!buf_file) {
247 		fprintf(stderr, "Failed to open memstream: %d\n", errno);
248 		return NULL;
249 	}
250 
251 	d = btf_dump__new(btf, btf_dump_printf, buf_file, NULL);
252 	if (libbpf_get_error(d)) {
253 		fprintf(stderr, "Failed to create btf_dump instance: %ld\n", libbpf_get_error(d));
254 		goto err_out;
255 	}
256 
257 	for (i = 1; i < btf__type_cnt(btf); i++) {
258 		err = btf_dump__dump_type(d, i);
259 		if (err) {
260 			fprintf(stderr, "Failed to dump type [%d]: %d\n", i, err);
261 			goto err_out;
262 		}
263 	}
264 
265 	btf_dump__free(d);
266 	fflush(buf_file);
267 	fclose(buf_file);
268 	return buf;
269 err_out:
270 	btf_dump__free(d);
271 	fclose(buf_file);
272 	return NULL;
273 }
274