xref: /openbmc/linux/tools/lib/bpf/skel_internal.h (revision 2cf1c348)
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 #ifndef __NR_bpf
11 # if defined(__mips__) && defined(_ABIO32)
12 #  define __NR_bpf 4355
13 # elif defined(__mips__) && defined(_ABIN32)
14 #  define __NR_bpf 6319
15 # elif defined(__mips__) && defined(_ABI64)
16 #  define __NR_bpf 5315
17 # endif
18 #endif
19 
20 /* This file is a base header for auto-generated *.lskel.h files.
21  * Its contents will change and may become part of auto-generation in the future.
22  *
23  * The layout of bpf_[map|prog]_desc and bpf_loader_ctx is feature dependent
24  * and will change from one version of libbpf to another and features
25  * requested during loader program generation.
26  */
27 struct bpf_map_desc {
28 	union {
29 		/* input for the loader prog */
30 		struct {
31 			__aligned_u64 initial_value;
32 			__u32 max_entries;
33 		};
34 		/* output of the loader prog */
35 		struct {
36 			int map_fd;
37 		};
38 	};
39 };
40 struct bpf_prog_desc {
41 	int prog_fd;
42 };
43 
44 struct bpf_loader_ctx {
45 	size_t sz;
46 	__u32 log_level;
47 	__u32 log_size;
48 	__u64 log_buf;
49 };
50 
51 struct bpf_load_and_run_opts {
52 	struct bpf_loader_ctx *ctx;
53 	const void *data;
54 	const void *insns;
55 	__u32 data_sz;
56 	__u32 insns_sz;
57 	const char *errstr;
58 };
59 
60 static inline int skel_sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
61 			  unsigned int size)
62 {
63 	return syscall(__NR_bpf, cmd, attr, size);
64 }
65 
66 static inline int skel_closenz(int fd)
67 {
68 	if (fd > 0)
69 		return close(fd);
70 	return -EINVAL;
71 }
72 
73 static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
74 {
75 	int map_fd = -1, prog_fd = -1, key = 0, err;
76 	union bpf_attr attr;
77 
78 	map_fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, "__loader.map", 4, opts->data_sz, 1, NULL);
79 	if (map_fd < 0) {
80 		opts->errstr = "failed to create loader map";
81 		err = -errno;
82 		goto out;
83 	}
84 
85 	err = bpf_map_update_elem(map_fd, &key, opts->data, 0);
86 	if (err < 0) {
87 		opts->errstr = "failed to update loader map";
88 		err = -errno;
89 		goto out;
90 	}
91 
92 	memset(&attr, 0, sizeof(attr));
93 	attr.prog_type = BPF_PROG_TYPE_SYSCALL;
94 	attr.insns = (long) opts->insns;
95 	attr.insn_cnt = opts->insns_sz / sizeof(struct bpf_insn);
96 	attr.license = (long) "Dual BSD/GPL";
97 	memcpy(attr.prog_name, "__loader.prog", sizeof("__loader.prog"));
98 	attr.fd_array = (long) &map_fd;
99 	attr.log_level = opts->ctx->log_level;
100 	attr.log_size = opts->ctx->log_size;
101 	attr.log_buf = opts->ctx->log_buf;
102 	attr.prog_flags = BPF_F_SLEEPABLE;
103 	prog_fd = skel_sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
104 	if (prog_fd < 0) {
105 		opts->errstr = "failed to load loader prog";
106 		err = -errno;
107 		goto out;
108 	}
109 
110 	memset(&attr, 0, sizeof(attr));
111 	attr.test.prog_fd = prog_fd;
112 	attr.test.ctx_in = (long) opts->ctx;
113 	attr.test.ctx_size_in = opts->ctx->sz;
114 	err = skel_sys_bpf(BPF_PROG_RUN, &attr, sizeof(attr));
115 	if (err < 0 || (int)attr.test.retval < 0) {
116 		opts->errstr = "failed to execute loader prog";
117 		if (err < 0) {
118 			err = -errno;
119 		} else {
120 			err = (int)attr.test.retval;
121 			errno = -err;
122 		}
123 		goto out;
124 	}
125 	err = 0;
126 out:
127 	if (map_fd >= 0)
128 		close(map_fd);
129 	if (prog_fd >= 0)
130 		close(prog_fd);
131 	return err;
132 }
133 
134 #endif
135