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
sanitize_identifier(char * name)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
str_has_suffix(const char * str,const char * suffix)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
get_obj_name(char * name,const char * file)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
get_header_guard(char * guard,const char * obj_name)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
get_map_ident(const struct bpf_map * map)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
codegen_btf_dump_printf(void * ctx,const char * fmt,va_list args)90 static void codegen_btf_dump_printf(void *ctx, const char *fmt, va_list args)
91 {
92 vprintf(fmt, args);
93 }
94
codegen_datasec_def(struct bpf_object * obj,struct btf * btf,struct btf_dump * d,const struct btf_type * sec,const char * obj_name)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
codegen_datasecs(struct bpf_object * obj,const char * obj_name)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
codegen(const char * template,...)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
print_hex(const char * data,int data_sz)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
bpf_map_mmap_sz(const struct bpf_map * map)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
codegen_attach_detach(struct bpf_object * obj,const char * obj_name)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
codegen_destroy(struct bpf_object * obj,const char * obj_name)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$s.map_fd); \n\
421 ", ident);
422 }
423 codegen("\
424 \n\
425 free(skel); \n\
426 } \n\
427 ",
428 obj_name);
429 }
430
gen_trace(struct bpf_object * obj,const char * obj_name,const char * header_guard)431 static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *header_guard)
432 {
433 struct bpf_object_load_attr load_attr = {};
434 DECLARE_LIBBPF_OPTS(gen_loader_opts, opts);
435 struct bpf_map *map;
436 int err = 0;
437
438 err = bpf_object__gen_loader(obj, &opts);
439 if (err)
440 return err;
441
442 load_attr.obj = obj;
443 if (verifier_logs)
444 /* log_level1 + log_level2 + stats, but not stable UAPI */
445 load_attr.log_level = 1 + 2 + 4;
446
447 err = bpf_object__load_xattr(&load_attr);
448 if (err) {
449 p_err("failed to load object file");
450 goto out;
451 }
452 /* If there was no error during load then gen_loader_opts
453 * are populated with the loader program.
454 */
455
456 /* finish generating 'struct skel' */
457 codegen("\
458 \n\
459 }; \n\
460 ", obj_name);
461
462
463 codegen_attach_detach(obj, obj_name);
464
465 codegen_destroy(obj, obj_name);
466
467 codegen("\
468 \n\
469 static inline struct %1$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
do_skeleton(int argc,char ** argv)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$s *obj) \n\
867 { \n\
868 struct bpf_object_skeleton *s; \n\
869 \n\
870 s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\
871 if (!s) \n\
872 goto err; \n\
873 \n\
874 s->sz = sizeof(*s); \n\
875 s->name = \"%1$s\"; \n\
876 s->obj = &obj->obj; \n\
877 ",
878 obj_name
879 );
880 if (map_cnt) {
881 codegen("\
882 \n\
883 \n\
884 /* maps */ \n\
885 s->map_cnt = %zu; \n\
886 s->map_skel_sz = sizeof(*s->maps); \n\
887 s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);\n\
888 if (!s->maps) \n\
889 goto err; \n\
890 ",
891 map_cnt
892 );
893 i = 0;
894 bpf_object__for_each_map(map, obj) {
895 ident = get_map_ident(map);
896
897 if (!ident)
898 continue;
899
900 codegen("\
901 \n\
902 \n\
903 s->maps[%zu].name = \"%s\"; \n\
904 s->maps[%zu].map = &obj->maps.%s; \n\
905 ",
906 i, bpf_map__name(map), i, ident);
907 /* memory-mapped internal maps */
908 if (bpf_map__is_internal(map) &&
909 (bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) {
910 printf("\ts->maps[%zu].mmaped = (void **)&obj->%s;\n",
911 i, ident);
912 }
913 i++;
914 }
915 }
916 if (prog_cnt) {
917 codegen("\
918 \n\
919 \n\
920 /* programs */ \n\
921 s->prog_cnt = %zu; \n\
922 s->prog_skel_sz = sizeof(*s->progs); \n\
923 s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);\n\
924 if (!s->progs) \n\
925 goto err; \n\
926 ",
927 prog_cnt
928 );
929 i = 0;
930 bpf_object__for_each_program(prog, obj) {
931 codegen("\
932 \n\
933 \n\
934 s->progs[%1$zu].name = \"%2$s\"; \n\
935 s->progs[%1$zu].prog = &obj->progs.%2$s;\n\
936 s->progs[%1$zu].link = &obj->links.%2$s;\n\
937 ",
938 i, bpf_program__name(prog));
939 i++;
940 }
941 }
942 codegen("\
943 \n\
944 \n\
945 s->data_sz = %d; \n\
946 s->data = (void *)\"\\ \n\
947 ",
948 file_sz);
949
950 /* embed contents of BPF object file */
951 print_hex(obj_data, file_sz);
952
953 codegen("\
954 \n\
955 \"; \n\
956 \n\
957 obj->skeleton = s; \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
do_object(int argc,char ** argv)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
do_help(int argc,char ** argv)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 " {-L|--use-loader} }\n"
1031 "",
1032 bin_name, "gen");
1033
1034 return 0;
1035 }
1036
1037 static const struct cmd cmds[] = {
1038 { "object", do_object },
1039 { "skeleton", do_skeleton },
1040 { "help", do_help },
1041 { 0 }
1042 };
1043
do_gen(int argc,char ** argv)1044 int do_gen(int argc, char **argv)
1045 {
1046 return cmd_select(cmds, argc, argv, do_help);
1047 }
1048