xref: /openbmc/linux/tools/bpf/bpftool/gen.c (revision 35267cea)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2019 Facebook */
3 
4 #ifndef _GNU_SOURCE
5 #define _GNU_SOURCE
6 #endif
7 #include <ctype.h>
8 #include <errno.h>
9 #include <fcntl.h>
10 #include <linux/err.h>
11 #include <stdbool.h>
12 #include <stdio.h>
13 #include <string.h>
14 #include <unistd.h>
15 #include <bpf/bpf.h>
16 #include <bpf/libbpf.h>
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/mman.h>
20 #include <bpf/btf.h>
21 #include <bpf/bpf_gen_internal.h>
22 
23 #include "json_writer.h"
24 #include "main.h"
25 
26 #define MAX_OBJ_NAME_LEN 64
27 
28 static void sanitize_identifier(char *name)
29 {
30 	int i;
31 
32 	for (i = 0; name[i]; i++)
33 		if (!isalnum(name[i]) && name[i] != '_')
34 			name[i] = '_';
35 }
36 
37 static bool str_has_suffix(const char *str, const char *suffix)
38 {
39 	size_t i, n1 = strlen(str), n2 = strlen(suffix);
40 
41 	if (n1 < n2)
42 		return false;
43 
44 	for (i = 0; i < n2; i++) {
45 		if (str[n1 - i - 1] != suffix[n2 - i - 1])
46 			return false;
47 	}
48 
49 	return true;
50 }
51 
52 static void get_obj_name(char *name, const char *file)
53 {
54 	/* Using basename() GNU version which doesn't modify arg. */
55 	strncpy(name, basename(file), MAX_OBJ_NAME_LEN - 1);
56 	name[MAX_OBJ_NAME_LEN - 1] = '\0';
57 	if (str_has_suffix(name, ".o"))
58 		name[strlen(name) - 2] = '\0';
59 	sanitize_identifier(name);
60 }
61 
62 static void get_header_guard(char *guard, const char *obj_name)
63 {
64 	int i;
65 
66 	sprintf(guard, "__%s_SKEL_H__", obj_name);
67 	for (i = 0; guard[i]; i++)
68 		guard[i] = toupper(guard[i]);
69 }
70 
71 static const char *get_map_ident(const struct bpf_map *map)
72 {
73 	const char *name = bpf_map__name(map);
74 
75 	if (!bpf_map__is_internal(map))
76 		return name;
77 
78 	if (str_has_suffix(name, ".data"))
79 		return "data";
80 	else if (str_has_suffix(name, ".rodata"))
81 		return "rodata";
82 	else if (str_has_suffix(name, ".bss"))
83 		return "bss";
84 	else if (str_has_suffix(name, ".kconfig"))
85 		return "kconfig";
86 	else
87 		return NULL;
88 }
89 
90 static void codegen_btf_dump_printf(void *ctx, const char *fmt, va_list args)
91 {
92 	vprintf(fmt, args);
93 }
94 
95 static int codegen_datasec_def(struct bpf_object *obj,
96 			       struct btf *btf,
97 			       struct btf_dump *d,
98 			       const struct btf_type *sec,
99 			       const char *obj_name)
100 {
101 	const char *sec_name = btf__name_by_offset(btf, sec->name_off);
102 	const struct btf_var_secinfo *sec_var = btf_var_secinfos(sec);
103 	int i, err, off = 0, pad_cnt = 0, vlen = btf_vlen(sec);
104 	const char *sec_ident;
105 	char var_ident[256];
106 	bool strip_mods = false;
107 
108 	if (strcmp(sec_name, ".data") == 0) {
109 		sec_ident = "data";
110 		strip_mods = true;
111 	} else if (strcmp(sec_name, ".bss") == 0) {
112 		sec_ident = "bss";
113 		strip_mods = true;
114 	} else if (strcmp(sec_name, ".rodata") == 0) {
115 		sec_ident = "rodata";
116 		strip_mods = true;
117 	} else if (strcmp(sec_name, ".kconfig") == 0) {
118 		sec_ident = "kconfig";
119 	} else {
120 		return 0;
121 	}
122 
123 	printf("	struct %s__%s {\n", obj_name, sec_ident);
124 	for (i = 0; i < vlen; i++, sec_var++) {
125 		const struct btf_type *var = btf__type_by_id(btf, sec_var->type);
126 		const char *var_name = btf__name_by_offset(btf, var->name_off);
127 		DECLARE_LIBBPF_OPTS(btf_dump_emit_type_decl_opts, opts,
128 			.field_name = var_ident,
129 			.indent_level = 2,
130 			.strip_mods = strip_mods,
131 		);
132 		int need_off = sec_var->offset, align_off, align;
133 		__u32 var_type_id = var->type;
134 
135 		/* static variables are not exposed through BPF skeleton */
136 		if (btf_var(var)->linkage == BTF_VAR_STATIC)
137 			continue;
138 
139 		if (off > need_off) {
140 			p_err("Something is wrong for %s's variable #%d: need offset %d, already at %d.\n",
141 			      sec_name, i, need_off, off);
142 			return -EINVAL;
143 		}
144 
145 		align = btf__align_of(btf, var->type);
146 		if (align <= 0) {
147 			p_err("Failed to determine alignment of variable '%s': %d",
148 			      var_name, align);
149 			return -EINVAL;
150 		}
151 		/* Assume 32-bit architectures when generating data section
152 		 * struct memory layout. Given bpftool can't know which target
153 		 * host architecture it's emitting skeleton for, we need to be
154 		 * conservative and assume 32-bit one to ensure enough padding
155 		 * bytes are generated for pointer and long types. This will
156 		 * still work correctly for 64-bit architectures, because in
157 		 * the worst case we'll generate unnecessary padding field,
158 		 * which on 64-bit architectures is not strictly necessary and
159 		 * would be handled by natural 8-byte alignment. But it still
160 		 * will be a correct memory layout, based on recorded offsets
161 		 * in BTF.
162 		 */
163 		if (align > 4)
164 			align = 4;
165 
166 		align_off = (off + align - 1) / align * align;
167 		if (align_off != need_off) {
168 			printf("\t\tchar __pad%d[%d];\n",
169 			       pad_cnt, need_off - off);
170 			pad_cnt++;
171 		}
172 
173 		/* sanitize variable name, e.g., for static vars inside
174 		 * a function, it's name is '<function name>.<variable name>',
175 		 * which we'll turn into a '<function name>_<variable name>'
176 		 */
177 		var_ident[0] = '\0';
178 		strncat(var_ident, var_name, sizeof(var_ident) - 1);
179 		sanitize_identifier(var_ident);
180 
181 		printf("\t\t");
182 		err = btf_dump__emit_type_decl(d, var_type_id, &opts);
183 		if (err)
184 			return err;
185 		printf(";\n");
186 
187 		off = sec_var->offset + sec_var->size;
188 	}
189 	printf("	} *%s;\n", sec_ident);
190 	return 0;
191 }
192 
193 static int codegen_datasecs(struct bpf_object *obj, const char *obj_name)
194 {
195 	struct btf *btf = bpf_object__btf(obj);
196 	int n = btf__get_nr_types(btf);
197 	struct btf_dump *d;
198 	int i, err = 0;
199 
200 	d = btf_dump__new(btf, NULL, NULL, codegen_btf_dump_printf);
201 	if (IS_ERR(d))
202 		return PTR_ERR(d);
203 
204 	for (i = 1; i <= n; i++) {
205 		const struct btf_type *t = btf__type_by_id(btf, i);
206 
207 		if (!btf_is_datasec(t))
208 			continue;
209 
210 		err = codegen_datasec_def(obj, btf, d, t, obj_name);
211 		if (err)
212 			goto out;
213 	}
214 out:
215 	btf_dump__free(d);
216 	return err;
217 }
218 
219 static void codegen(const char *template, ...)
220 {
221 	const char *src, *end;
222 	int skip_tabs = 0, n;
223 	char *s, *dst;
224 	va_list args;
225 	char c;
226 
227 	n = strlen(template);
228 	s = malloc(n + 1);
229 	if (!s)
230 		exit(-1);
231 	src = template;
232 	dst = s;
233 
234 	/* find out "baseline" indentation to skip */
235 	while ((c = *src++)) {
236 		if (c == '\t') {
237 			skip_tabs++;
238 		} else if (c == '\n') {
239 			break;
240 		} else {
241 			p_err("unrecognized character at pos %td in template '%s'",
242 			      src - template - 1, template);
243 			free(s);
244 			exit(-1);
245 		}
246 	}
247 
248 	while (*src) {
249 		/* skip baseline indentation tabs */
250 		for (n = skip_tabs; n > 0; n--, src++) {
251 			if (*src != '\t') {
252 				p_err("not enough tabs at pos %td in template '%s'",
253 				      src - template - 1, template);
254 				free(s);
255 				exit(-1);
256 			}
257 		}
258 		/* trim trailing whitespace */
259 		end = strchrnul(src, '\n');
260 		for (n = end - src; n > 0 && isspace(src[n - 1]); n--)
261 			;
262 		memcpy(dst, src, n);
263 		dst += n;
264 		if (*end)
265 			*dst++ = '\n';
266 		src = *end ? end + 1 : end;
267 	}
268 	*dst++ = '\0';
269 
270 	/* print out using adjusted template */
271 	va_start(args, template);
272 	n = vprintf(s, args);
273 	va_end(args);
274 
275 	free(s);
276 }
277 
278 static void print_hex(const char *data, int data_sz)
279 {
280 	int i, len;
281 
282 	for (i = 0, len = 0; i < data_sz; i++) {
283 		int w = data[i] ? 4 : 2;
284 
285 		len += w;
286 		if (len > 78) {
287 			printf("\\\n");
288 			len = w;
289 		}
290 		if (!data[i])
291 			printf("\\0");
292 		else
293 			printf("\\x%02x", (unsigned char)data[i]);
294 	}
295 }
296 
297 static size_t bpf_map_mmap_sz(const struct bpf_map *map)
298 {
299 	long page_sz = sysconf(_SC_PAGE_SIZE);
300 	size_t map_sz;
301 
302 	map_sz = (size_t)roundup(bpf_map__value_size(map), 8) * bpf_map__max_entries(map);
303 	map_sz = roundup(map_sz, page_sz);
304 	return map_sz;
305 }
306 
307 static void codegen_attach_detach(struct bpf_object *obj, const char *obj_name)
308 {
309 	struct bpf_program *prog;
310 
311 	bpf_object__for_each_program(prog, obj) {
312 		const char *tp_name;
313 
314 		codegen("\
315 			\n\
316 			\n\
317 			static inline int					    \n\
318 			%1$s__%2$s__attach(struct %1$s *skel)			    \n\
319 			{							    \n\
320 				int prog_fd = skel->progs.%2$s.prog_fd;		    \n\
321 			", obj_name, bpf_program__name(prog));
322 
323 		switch (bpf_program__get_type(prog)) {
324 		case BPF_PROG_TYPE_RAW_TRACEPOINT:
325 			tp_name = strchr(bpf_program__section_name(prog), '/') + 1;
326 			printf("\tint fd = bpf_raw_tracepoint_open(\"%s\", prog_fd);\n", tp_name);
327 			break;
328 		case BPF_PROG_TYPE_TRACING:
329 			printf("\tint fd = bpf_raw_tracepoint_open(NULL, prog_fd);\n");
330 			break;
331 		default:
332 			printf("\tint fd = ((void)prog_fd, 0); /* auto-attach not supported */\n");
333 			break;
334 		}
335 		codegen("\
336 			\n\
337 										    \n\
338 				if (fd > 0)					    \n\
339 					skel->links.%1$s_fd = fd;		    \n\
340 				return fd;					    \n\
341 			}							    \n\
342 			", bpf_program__name(prog));
343 	}
344 
345 	codegen("\
346 		\n\
347 									    \n\
348 		static inline int					    \n\
349 		%1$s__attach(struct %1$s *skel)				    \n\
350 		{							    \n\
351 			int ret = 0;					    \n\
352 									    \n\
353 		", obj_name);
354 
355 	bpf_object__for_each_program(prog, obj) {
356 		codegen("\
357 			\n\
358 				ret = ret < 0 ? ret : %1$s__%2$s__attach(skel);   \n\
359 			", obj_name, bpf_program__name(prog));
360 	}
361 
362 	codegen("\
363 		\n\
364 			return ret < 0 ? ret : 0;			    \n\
365 		}							    \n\
366 									    \n\
367 		static inline void					    \n\
368 		%1$s__detach(struct %1$s *skel)				    \n\
369 		{							    \n\
370 		", obj_name);
371 
372 	bpf_object__for_each_program(prog, obj) {
373 		codegen("\
374 			\n\
375 				skel_closenz(skel->links.%1$s_fd);	    \n\
376 			", bpf_program__name(prog));
377 	}
378 
379 	codegen("\
380 		\n\
381 		}							    \n\
382 		");
383 }
384 
385 static void codegen_destroy(struct bpf_object *obj, const char *obj_name)
386 {
387 	struct bpf_program *prog;
388 	struct bpf_map *map;
389 
390 	codegen("\
391 		\n\
392 		static void						    \n\
393 		%1$s__destroy(struct %1$s *skel)			    \n\
394 		{							    \n\
395 			if (!skel)					    \n\
396 				return;					    \n\
397 			%1$s__detach(skel);				    \n\
398 		",
399 		obj_name);
400 
401 	bpf_object__for_each_program(prog, obj) {
402 		codegen("\
403 			\n\
404 				skel_closenz(skel->progs.%1$s.prog_fd);	    \n\
405 			", bpf_program__name(prog));
406 	}
407 
408 	bpf_object__for_each_map(map, obj) {
409 		const char * ident;
410 
411 		ident = get_map_ident(map);
412 		if (!ident)
413 			continue;
414 		if (bpf_map__is_internal(map) &&
415 		    (bpf_map__def(map)->map_flags & BPF_F_MMAPABLE))
416 			printf("\tmunmap(skel->%1$s, %2$zd);\n",
417 			       ident, bpf_map_mmap_sz(map));
418 		codegen("\
419 			\n\
420 				skel_closenz(skel->maps.%1$s.map_fd);	    \n\
421 			", ident);
422 	}
423 	codegen("\
424 		\n\
425 			free(skel);					    \n\
426 		}							    \n\
427 		",
428 		obj_name);
429 }
430 
431 static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *header_guard)
432 {
433 	struct bpf_object_load_attr load_attr = {};
434 	DECLARE_LIBBPF_OPTS(gen_loader_opts, opts);
435 	struct bpf_map *map;
436 	int err = 0;
437 
438 	err = bpf_object__gen_loader(obj, &opts);
439 	if (err)
440 		return err;
441 
442 	load_attr.obj = obj;
443 	if (verifier_logs)
444 		/* log_level1 + log_level2 + stats, but not stable UAPI */
445 		load_attr.log_level = 1 + 2 + 4;
446 
447 	err = bpf_object__load_xattr(&load_attr);
448 	if (err) {
449 		p_err("failed to load object file");
450 		goto out;
451 	}
452 	/* If there was no error during load then gen_loader_opts
453 	 * are populated with the loader program.
454 	 */
455 
456 	/* finish generating 'struct skel' */
457 	codegen("\
458 		\n\
459 		};							    \n\
460 		", obj_name);
461 
462 
463 	codegen_attach_detach(obj, obj_name);
464 
465 	codegen_destroy(obj, obj_name);
466 
467 	codegen("\
468 		\n\
469 		static inline struct %1$s *				    \n\
470 		%1$s__open(void)					    \n\
471 		{							    \n\
472 			struct %1$s *skel;				    \n\
473 									    \n\
474 			skel = calloc(sizeof(*skel), 1);		    \n\
475 			if (!skel)					    \n\
476 				goto cleanup;				    \n\
477 			skel->ctx.sz = (void *)&skel->links - (void *)skel; \n\
478 		",
479 		obj_name, opts.data_sz);
480 	bpf_object__for_each_map(map, obj) {
481 		const char *ident;
482 		const void *mmap_data = NULL;
483 		size_t mmap_size = 0;
484 
485 		ident = get_map_ident(map);
486 		if (!ident)
487 			continue;
488 
489 		if (!bpf_map__is_internal(map) ||
490 		    !(bpf_map__def(map)->map_flags & BPF_F_MMAPABLE))
491 			continue;
492 
493 		codegen("\
494 			\n\
495 				skel->%1$s =					 \n\
496 					mmap(NULL, %2$zd, PROT_READ | PROT_WRITE,\n\
497 					     MAP_SHARED | MAP_ANONYMOUS, -1, 0); \n\
498 				if (skel->%1$s == (void *) -1)			 \n\
499 					goto cleanup;				 \n\
500 				memcpy(skel->%1$s, (void *)\"\\			 \n\
501 			", ident, bpf_map_mmap_sz(map));
502 		mmap_data = bpf_map__initial_value(map, &mmap_size);
503 		print_hex(mmap_data, mmap_size);
504 		printf("\", %2$zd);\n"
505 		       "\tskel->maps.%1$s.initial_value = (__u64)(long)skel->%1$s;\n",
506 		       ident, mmap_size);
507 	}
508 	codegen("\
509 		\n\
510 			return skel;					    \n\
511 		cleanup:						    \n\
512 			%1$s__destroy(skel);				    \n\
513 			return NULL;					    \n\
514 		}							    \n\
515 									    \n\
516 		static inline int					    \n\
517 		%1$s__load(struct %1$s *skel)				    \n\
518 		{							    \n\
519 			struct bpf_load_and_run_opts opts = {};		    \n\
520 			int err;					    \n\
521 									    \n\
522 			opts.ctx = (struct bpf_loader_ctx *)skel;	    \n\
523 			opts.data_sz = %2$d;				    \n\
524 			opts.data = (void *)\"\\			    \n\
525 		",
526 		obj_name, opts.data_sz);
527 	print_hex(opts.data, opts.data_sz);
528 	codegen("\
529 		\n\
530 		\";							    \n\
531 		");
532 
533 	codegen("\
534 		\n\
535 			opts.insns_sz = %d;				    \n\
536 			opts.insns = (void *)\"\\			    \n\
537 		",
538 		opts.insns_sz);
539 	print_hex(opts.insns, opts.insns_sz);
540 	codegen("\
541 		\n\
542 		\";							    \n\
543 			err = bpf_load_and_run(&opts);			    \n\
544 			if (err < 0)					    \n\
545 				return err;				    \n\
546 		", obj_name);
547 	bpf_object__for_each_map(map, obj) {
548 		const char *ident, *mmap_flags;
549 
550 		ident = get_map_ident(map);
551 		if (!ident)
552 			continue;
553 
554 		if (!bpf_map__is_internal(map) ||
555 		    !(bpf_map__def(map)->map_flags & BPF_F_MMAPABLE))
556 			continue;
557 		if (bpf_map__def(map)->map_flags & BPF_F_RDONLY_PROG)
558 			mmap_flags = "PROT_READ";
559 		else
560 			mmap_flags = "PROT_READ | PROT_WRITE";
561 
562 		printf("\tskel->%1$s =\n"
563 		       "\t\tmmap(skel->%1$s, %2$zd, %3$s, MAP_SHARED | MAP_FIXED,\n"
564 		       "\t\t\tskel->maps.%1$s.map_fd, 0);\n",
565 		       ident, bpf_map_mmap_sz(map), mmap_flags);
566 	}
567 	codegen("\
568 		\n\
569 			return 0;					    \n\
570 		}							    \n\
571 									    \n\
572 		static inline struct %1$s *				    \n\
573 		%1$s__open_and_load(void)				    \n\
574 		{							    \n\
575 			struct %1$s *skel;				    \n\
576 									    \n\
577 			skel = %1$s__open();				    \n\
578 			if (!skel)					    \n\
579 				return NULL;				    \n\
580 			if (%1$s__load(skel)) {				    \n\
581 				%1$s__destroy(skel);			    \n\
582 				return NULL;				    \n\
583 			}						    \n\
584 			return skel;					    \n\
585 		}							    \n\
586 		", obj_name);
587 
588 	codegen("\
589 		\n\
590 									    \n\
591 		#endif /* %s */						    \n\
592 		",
593 		header_guard);
594 	err = 0;
595 out:
596 	return err;
597 }
598 
599 static int do_skeleton(int argc, char **argv)
600 {
601 	char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")];
602 	size_t i, map_cnt = 0, prog_cnt = 0, file_sz, mmap_sz;
603 	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
604 	char obj_name[MAX_OBJ_NAME_LEN] = "", *obj_data;
605 	struct bpf_object *obj = NULL;
606 	const char *file, *ident;
607 	struct bpf_program *prog;
608 	int fd, err = -1;
609 	struct bpf_map *map;
610 	struct btf *btf;
611 	struct stat st;
612 
613 	if (!REQ_ARGS(1)) {
614 		usage();
615 		return -1;
616 	}
617 	file = GET_ARG();
618 
619 	while (argc) {
620 		if (!REQ_ARGS(2))
621 			return -1;
622 
623 		if (is_prefix(*argv, "name")) {
624 			NEXT_ARG();
625 
626 			if (obj_name[0] != '\0') {
627 				p_err("object name already specified");
628 				return -1;
629 			}
630 
631 			strncpy(obj_name, *argv, MAX_OBJ_NAME_LEN - 1);
632 			obj_name[MAX_OBJ_NAME_LEN - 1] = '\0';
633 		} else {
634 			p_err("unknown arg %s", *argv);
635 			return -1;
636 		}
637 
638 		NEXT_ARG();
639 	}
640 
641 	if (argc) {
642 		p_err("extra unknown arguments");
643 		return -1;
644 	}
645 
646 	if (stat(file, &st)) {
647 		p_err("failed to stat() %s: %s", file, strerror(errno));
648 		return -1;
649 	}
650 	file_sz = st.st_size;
651 	mmap_sz = roundup(file_sz, sysconf(_SC_PAGE_SIZE));
652 	fd = open(file, O_RDONLY);
653 	if (fd < 0) {
654 		p_err("failed to open() %s: %s", file, strerror(errno));
655 		return -1;
656 	}
657 	obj_data = mmap(NULL, mmap_sz, PROT_READ, MAP_PRIVATE, fd, 0);
658 	if (obj_data == MAP_FAILED) {
659 		obj_data = NULL;
660 		p_err("failed to mmap() %s: %s", file, strerror(errno));
661 		goto out;
662 	}
663 	if (obj_name[0] == '\0')
664 		get_obj_name(obj_name, file);
665 	opts.object_name = obj_name;
666 	obj = bpf_object__open_mem(obj_data, file_sz, &opts);
667 	if (IS_ERR(obj)) {
668 		char err_buf[256];
669 
670 		libbpf_strerror(PTR_ERR(obj), err_buf, sizeof(err_buf));
671 		p_err("failed to open BPF object file: %s", err_buf);
672 		obj = NULL;
673 		goto out;
674 	}
675 
676 	bpf_object__for_each_map(map, obj) {
677 		ident = get_map_ident(map);
678 		if (!ident) {
679 			p_err("ignoring unrecognized internal map '%s'...",
680 			      bpf_map__name(map));
681 			continue;
682 		}
683 		map_cnt++;
684 	}
685 	bpf_object__for_each_program(prog, obj) {
686 		prog_cnt++;
687 	}
688 
689 	get_header_guard(header_guard, obj_name);
690 	if (use_loader) {
691 		codegen("\
692 		\n\
693 		/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */   \n\
694 		/* THIS FILE IS AUTOGENERATED! */			    \n\
695 		#ifndef %2$s						    \n\
696 		#define %2$s						    \n\
697 									    \n\
698 		#include <stdlib.h>					    \n\
699 		#include <bpf/bpf.h>					    \n\
700 		#include <bpf/skel_internal.h>				    \n\
701 									    \n\
702 		struct %1$s {						    \n\
703 			struct bpf_loader_ctx ctx;			    \n\
704 		",
705 		obj_name, header_guard
706 		);
707 	} else {
708 		codegen("\
709 		\n\
710 		/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */   \n\
711 									    \n\
712 		/* THIS FILE IS AUTOGENERATED! */			    \n\
713 		#ifndef %2$s						    \n\
714 		#define %2$s						    \n\
715 									    \n\
716 		#include <errno.h>					    \n\
717 		#include <stdlib.h>					    \n\
718 		#include <bpf/libbpf.h>					    \n\
719 									    \n\
720 		struct %1$s {						    \n\
721 			struct bpf_object_skeleton *skeleton;		    \n\
722 			struct bpf_object *obj;				    \n\
723 		",
724 		obj_name, header_guard
725 		);
726 	}
727 
728 	if (map_cnt) {
729 		printf("\tstruct {\n");
730 		bpf_object__for_each_map(map, obj) {
731 			ident = get_map_ident(map);
732 			if (!ident)
733 				continue;
734 			if (use_loader)
735 				printf("\t\tstruct bpf_map_desc %s;\n", ident);
736 			else
737 				printf("\t\tstruct bpf_map *%s;\n", ident);
738 		}
739 		printf("\t} maps;\n");
740 	}
741 
742 	if (prog_cnt) {
743 		printf("\tstruct {\n");
744 		bpf_object__for_each_program(prog, obj) {
745 			if (use_loader)
746 				printf("\t\tstruct bpf_prog_desc %s;\n",
747 				       bpf_program__name(prog));
748 			else
749 				printf("\t\tstruct bpf_program *%s;\n",
750 				       bpf_program__name(prog));
751 		}
752 		printf("\t} progs;\n");
753 		printf("\tstruct {\n");
754 		bpf_object__for_each_program(prog, obj) {
755 			if (use_loader)
756 				printf("\t\tint %s_fd;\n",
757 				       bpf_program__name(prog));
758 			else
759 				printf("\t\tstruct bpf_link *%s;\n",
760 				       bpf_program__name(prog));
761 		}
762 		printf("\t} links;\n");
763 	}
764 
765 	btf = bpf_object__btf(obj);
766 	if (btf) {
767 		err = codegen_datasecs(obj, obj_name);
768 		if (err)
769 			goto out;
770 	}
771 	if (use_loader) {
772 		err = gen_trace(obj, obj_name, header_guard);
773 		goto out;
774 	}
775 
776 	codegen("\
777 		\n\
778 		};							    \n\
779 									    \n\
780 		static void						    \n\
781 		%1$s__destroy(struct %1$s *obj)				    \n\
782 		{							    \n\
783 			if (!obj)					    \n\
784 				return;					    \n\
785 			if (obj->skeleton)				    \n\
786 				bpf_object__destroy_skeleton(obj->skeleton);\n\
787 			free(obj);					    \n\
788 		}							    \n\
789 									    \n\
790 		static inline int					    \n\
791 		%1$s__create_skeleton(struct %1$s *obj);		    \n\
792 									    \n\
793 		static inline struct %1$s *				    \n\
794 		%1$s__open_opts(const struct bpf_object_open_opts *opts)    \n\
795 		{							    \n\
796 			struct %1$s *obj;				    \n\
797 			int err;					    \n\
798 									    \n\
799 			obj = (struct %1$s *)calloc(1, sizeof(*obj));	    \n\
800 			if (!obj) {					    \n\
801 				errno = ENOMEM;				    \n\
802 				return NULL;				    \n\
803 			}						    \n\
804 									    \n\
805 			err = %1$s__create_skeleton(obj);		    \n\
806 			err = err ?: bpf_object__open_skeleton(obj->skeleton, opts);\n\
807 			if (err)					    \n\
808 				goto err_out;				    \n\
809 									    \n\
810 			return obj;					    \n\
811 		err_out:						    \n\
812 			%1$s__destroy(obj);				    \n\
813 			errno = -err;					    \n\
814 			return NULL;					    \n\
815 		}							    \n\
816 									    \n\
817 		static inline struct %1$s *				    \n\
818 		%1$s__open(void)					    \n\
819 		{							    \n\
820 			return %1$s__open_opts(NULL);			    \n\
821 		}							    \n\
822 									    \n\
823 		static inline int					    \n\
824 		%1$s__load(struct %1$s *obj)				    \n\
825 		{							    \n\
826 			return bpf_object__load_skeleton(obj->skeleton);    \n\
827 		}							    \n\
828 									    \n\
829 		static inline struct %1$s *				    \n\
830 		%1$s__open_and_load(void)				    \n\
831 		{							    \n\
832 			struct %1$s *obj;				    \n\
833 			int err;					    \n\
834 									    \n\
835 			obj = %1$s__open();				    \n\
836 			if (!obj)					    \n\
837 				return NULL;				    \n\
838 			err = %1$s__load(obj);				    \n\
839 			if (err) {					    \n\
840 				%1$s__destroy(obj);			    \n\
841 				errno = -err;				    \n\
842 				return NULL;				    \n\
843 			}						    \n\
844 			return obj;					    \n\
845 		}							    \n\
846 									    \n\
847 		static inline int					    \n\
848 		%1$s__attach(struct %1$s *obj)				    \n\
849 		{							    \n\
850 			return bpf_object__attach_skeleton(obj->skeleton);  \n\
851 		}							    \n\
852 									    \n\
853 		static inline void					    \n\
854 		%1$s__detach(struct %1$s *obj)				    \n\
855 		{							    \n\
856 			return bpf_object__detach_skeleton(obj->skeleton);  \n\
857 		}							    \n\
858 		",
859 		obj_name
860 	);
861 
862 	codegen("\
863 		\n\
864 									    \n\
865 		static inline int					    \n\
866 		%1$s__create_skeleton(struct %1$s *obj)			    \n\
867 		{							    \n\
868 			struct bpf_object_skeleton *s;			    \n\
869 									    \n\
870 			s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\
871 			if (!s)						    \n\
872 				goto err;				    \n\
873 			obj->skeleton = s;				    \n\
874 									    \n\
875 			s->sz = sizeof(*s);				    \n\
876 			s->name = \"%1$s\";				    \n\
877 			s->obj = &obj->obj;				    \n\
878 		",
879 		obj_name
880 	);
881 	if (map_cnt) {
882 		codegen("\
883 			\n\
884 									    \n\
885 				/* maps */				    \n\
886 				s->map_cnt = %zu;			    \n\
887 				s->map_skel_sz = sizeof(*s->maps);	    \n\
888 				s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);\n\
889 				if (!s->maps)				    \n\
890 					goto err;			    \n\
891 			",
892 			map_cnt
893 		);
894 		i = 0;
895 		bpf_object__for_each_map(map, obj) {
896 			ident = get_map_ident(map);
897 
898 			if (!ident)
899 				continue;
900 
901 			codegen("\
902 				\n\
903 									    \n\
904 					s->maps[%zu].name = \"%s\";	    \n\
905 					s->maps[%zu].map = &obj->maps.%s;   \n\
906 				",
907 				i, bpf_map__name(map), i, ident);
908 			/* memory-mapped internal maps */
909 			if (bpf_map__is_internal(map) &&
910 			    (bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) {
911 				printf("\ts->maps[%zu].mmaped = (void **)&obj->%s;\n",
912 				       i, ident);
913 			}
914 			i++;
915 		}
916 	}
917 	if (prog_cnt) {
918 		codegen("\
919 			\n\
920 									    \n\
921 				/* programs */				    \n\
922 				s->prog_cnt = %zu;			    \n\
923 				s->prog_skel_sz = sizeof(*s->progs);	    \n\
924 				s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);\n\
925 				if (!s->progs)				    \n\
926 					goto err;			    \n\
927 			",
928 			prog_cnt
929 		);
930 		i = 0;
931 		bpf_object__for_each_program(prog, obj) {
932 			codegen("\
933 				\n\
934 									    \n\
935 					s->progs[%1$zu].name = \"%2$s\";    \n\
936 					s->progs[%1$zu].prog = &obj->progs.%2$s;\n\
937 					s->progs[%1$zu].link = &obj->links.%2$s;\n\
938 				",
939 				i, bpf_program__name(prog));
940 			i++;
941 		}
942 	}
943 	codegen("\
944 		\n\
945 									    \n\
946 			s->data_sz = %d;				    \n\
947 			s->data = (void *)\"\\				    \n\
948 		",
949 		file_sz);
950 
951 	/* embed contents of BPF object file */
952 	print_hex(obj_data, file_sz);
953 
954 	codegen("\
955 		\n\
956 		\";							    \n\
957 									    \n\
958 			return 0;					    \n\
959 		err:							    \n\
960 			bpf_object__destroy_skeleton(s);		    \n\
961 			return -ENOMEM;					    \n\
962 		}							    \n\
963 									    \n\
964 		#endif /* %s */						    \n\
965 		",
966 		header_guard);
967 	err = 0;
968 out:
969 	bpf_object__close(obj);
970 	if (obj_data)
971 		munmap(obj_data, mmap_sz);
972 	close(fd);
973 	return err;
974 }
975 
976 static int do_object(int argc, char **argv)
977 {
978 	struct bpf_linker *linker;
979 	const char *output_file, *file;
980 	int err = 0;
981 
982 	if (!REQ_ARGS(2)) {
983 		usage();
984 		return -1;
985 	}
986 
987 	output_file = GET_ARG();
988 
989 	linker = bpf_linker__new(output_file, NULL);
990 	if (!linker) {
991 		p_err("failed to create BPF linker instance");
992 		return -1;
993 	}
994 
995 	while (argc) {
996 		file = GET_ARG();
997 
998 		err = bpf_linker__add_file(linker, file, NULL);
999 		if (err) {
1000 			p_err("failed to link '%s': %s (%d)", file, strerror(err), err);
1001 			goto out;
1002 		}
1003 	}
1004 
1005 	err = bpf_linker__finalize(linker);
1006 	if (err) {
1007 		p_err("failed to finalize ELF file: %s (%d)", strerror(err), err);
1008 		goto out;
1009 	}
1010 
1011 	err = 0;
1012 out:
1013 	bpf_linker__free(linker);
1014 	return err;
1015 }
1016 
1017 static int do_help(int argc, char **argv)
1018 {
1019 	if (json_output) {
1020 		jsonw_null(json_wtr);
1021 		return 0;
1022 	}
1023 
1024 	fprintf(stderr,
1025 		"Usage: %1$s %2$s object OUTPUT_FILE INPUT_FILE [INPUT_FILE...]\n"
1026 		"       %1$s %2$s skeleton FILE [name OBJECT_NAME]\n"
1027 		"       %1$s %2$s help\n"
1028 		"\n"
1029 		"       " HELP_SPEC_OPTIONS "\n"
1030 		"",
1031 		bin_name, "gen");
1032 
1033 	return 0;
1034 }
1035 
1036 static const struct cmd cmds[] = {
1037 	{ "object",	do_object },
1038 	{ "skeleton",	do_skeleton },
1039 	{ "help",	do_help },
1040 	{ 0 }
1041 };
1042 
1043 int do_gen(int argc, char **argv)
1044 {
1045 	return cmd_select(cmds, argc, argv, do_help);
1046 }
1047