xref: /linux/tools/lib/bpf/skel_internal.h (revision 662f11d55ffd02933e1bd275d732b97eddccf870)
1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2 /* Copyright (c) 2021 Facebook */
3 #ifndef __SKEL_INTERNAL_H
4 #define __SKEL_INTERNAL_H
5 
6 #include <unistd.h>
7 #include <sys/syscall.h>
8 #include <sys/mman.h>
9 
10 /* This file is a base header for auto-generated *.lskel.h files.
11  * Its contents will change and may become part of auto-generation in the future.
12  *
13  * The layout of bpf_[map|prog]_desc and bpf_loader_ctx is feature dependent
14  * and will change from one version of libbpf to another and features
15  * requested during loader program generation.
16  */
17 struct bpf_map_desc {
18 	union {
19 		/* input for the loader prog */
20 		struct {
21 			__aligned_u64 initial_value;
22 			__u32 max_entries;
23 		};
24 		/* output of the loader prog */
25 		struct {
26 			int map_fd;
27 		};
28 	};
29 };
30 struct bpf_prog_desc {
31 	int prog_fd;
32 };
33 
34 struct bpf_loader_ctx {
35 	size_t sz;
36 	__u32 log_level;
37 	__u32 log_size;
38 	__u64 log_buf;
39 };
40 
41 struct bpf_load_and_run_opts {
42 	struct bpf_loader_ctx *ctx;
43 	const void *data;
44 	const void *insns;
45 	__u32 data_sz;
46 	__u32 insns_sz;
47 	const char *errstr;
48 };
49 
50 static inline int skel_sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
51 			  unsigned int size)
52 {
53 	return syscall(__NR_bpf, cmd, attr, size);
54 }
55 
56 static inline int skel_closenz(int fd)
57 {
58 	if (fd > 0)
59 		return close(fd);
60 	return -EINVAL;
61 }
62 
63 static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
64 {
65 	int map_fd = -1, prog_fd = -1, key = 0, err;
66 	union bpf_attr attr;
67 
68 	map_fd = bpf_create_map_name(BPF_MAP_TYPE_ARRAY, "__loader.map", 4,
69 				     opts->data_sz, 1, 0);
70 	if (map_fd < 0) {
71 		opts->errstr = "failed to create loader map";
72 		err = -errno;
73 		goto out;
74 	}
75 
76 	err = bpf_map_update_elem(map_fd, &key, opts->data, 0);
77 	if (err < 0) {
78 		opts->errstr = "failed to update loader map";
79 		err = -errno;
80 		goto out;
81 	}
82 
83 	memset(&attr, 0, sizeof(attr));
84 	attr.prog_type = BPF_PROG_TYPE_SYSCALL;
85 	attr.insns = (long) opts->insns;
86 	attr.insn_cnt = opts->insns_sz / sizeof(struct bpf_insn);
87 	attr.license = (long) "Dual BSD/GPL";
88 	memcpy(attr.prog_name, "__loader.prog", sizeof("__loader.prog"));
89 	attr.fd_array = (long) &map_fd;
90 	attr.log_level = opts->ctx->log_level;
91 	attr.log_size = opts->ctx->log_size;
92 	attr.log_buf = opts->ctx->log_buf;
93 	attr.prog_flags = BPF_F_SLEEPABLE;
94 	prog_fd = skel_sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
95 	if (prog_fd < 0) {
96 		opts->errstr = "failed to load loader prog";
97 		err = -errno;
98 		goto out;
99 	}
100 
101 	memset(&attr, 0, sizeof(attr));
102 	attr.test.prog_fd = prog_fd;
103 	attr.test.ctx_in = (long) opts->ctx;
104 	attr.test.ctx_size_in = opts->ctx->sz;
105 	err = skel_sys_bpf(BPF_PROG_RUN, &attr, sizeof(attr));
106 	if (err < 0 || (int)attr.test.retval < 0) {
107 		opts->errstr = "failed to execute loader prog";
108 		if (err < 0) {
109 			err = -errno;
110 		} else {
111 			err = (int)attr.test.retval;
112 			errno = -err;
113 		}
114 		goto out;
115 	}
116 	err = 0;
117 out:
118 	if (map_fd >= 0)
119 		close(map_fd);
120 	if (prog_fd >= 0)
121 		close(prog_fd);
122 	return err;
123 }
124 
125 #endif
126