1/*
2 * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "defs.h"
29
30#ifdef HAVE_LINUX_BPF_H
31# include <linux/bpf.h>
32#endif
33
34#include "xlat/bpf_commands.h"
35#include "xlat/bpf_map_types.h"
36#include "xlat/bpf_prog_types.h"
37#include "xlat/bpf_map_update_elem_flags.h"
38
39static int
40bpf_map_create(struct tcb *tcp, const long addr, unsigned int size)
41{
42	struct {
43		uint32_t map_type, key_size, value_size, max_entries;
44	} attr = {};
45
46	if (!size) {
47		printaddr(addr);
48		return RVAL_DECODED | RVAL_FD;
49	}
50	if (size > sizeof(attr))
51		size = sizeof(attr);
52	if (umoven_or_printaddr(tcp, addr, size, &attr))
53		return RVAL_DECODED | RVAL_FD;
54
55	tprints("{map_type=");
56	printxval(bpf_map_types, attr.map_type, "BPF_MAP_TYPE_???");
57	tprintf(", key_size=%u, value_size=%u, max_entries=%u}",
58		attr.key_size, attr.value_size, attr.max_entries);
59
60	return RVAL_DECODED | RVAL_FD;
61}
62
63static void
64bpf_map_update_elem(struct tcb *tcp, const long addr, unsigned int size)
65{
66	struct {
67		uint32_t map_fd;
68		uint64_t ATTRIBUTE_ALIGNED(8) key;
69		uint64_t ATTRIBUTE_ALIGNED(8) value;
70		uint64_t flags;
71	} attr = {};
72
73	if (!size) {
74		printaddr(addr);
75		return;
76	}
77	if (size > sizeof(attr))
78		size = sizeof(attr);
79	if (umoven_or_printaddr(tcp, addr, size, &attr))
80		return;
81
82	tprints("{map_fd=");
83	printfd(tcp, attr.map_fd);
84	tprintf(", key=%#" PRIx64 ", value=%#" PRIx64 ", flags=",
85		attr.key, attr.value);
86	printxval(bpf_map_update_elem_flags, attr.flags, "BPF_???");
87	tprints("}");
88}
89
90static void
91bpf_map_delete_elem(struct tcb *tcp, const long addr, unsigned int size)
92{
93	struct {
94		uint32_t map_fd;
95		uint64_t ATTRIBUTE_ALIGNED(8) key;
96	} attr = {};
97
98	if (!size) {
99		printaddr(addr);
100		return;
101	}
102	if (size > sizeof(attr))
103		size = sizeof(attr);
104	if (umoven_or_printaddr(tcp, addr, size, &attr))
105		return;
106
107	tprints("{map_fd=");
108	printfd(tcp, attr.map_fd);
109	tprintf(", key=%#" PRIx64 "}", attr.key);
110}
111
112static int
113bpf_map_io(struct tcb *tcp, const long addr, unsigned int size, const char *text)
114{
115	struct bpf_io_elem_struct {
116		uint32_t map_fd;
117		uint64_t ATTRIBUTE_ALIGNED(8) key;
118		uint64_t ATTRIBUTE_ALIGNED(8) value;
119	} attr = {};
120
121	if (exiting(tcp)) {
122		if (!syserror(tcp) && !umove_or_printaddr(tcp, addr, &attr))
123			tprintf(", %s=%#" PRIx64, text, attr.value);
124		tprints("}");
125		return RVAL_DECODED;
126	}
127
128	if (!size) {
129		printaddr(addr);
130		return RVAL_DECODED;
131	}
132	if (size > sizeof(attr))
133		size = sizeof(attr);
134	if (umoven_or_printaddr(tcp, addr, size, &attr))
135		return RVAL_DECODED;
136
137	tprints("{map_fd=");
138	printfd(tcp, attr.map_fd);
139	tprintf(", key=%#" PRIx64, attr.key);
140
141	return 0;
142}
143
144static int
145bpf_prog_load(struct tcb *tcp, const long addr, unsigned int size)
146{
147	struct {
148		uint32_t prog_type, insn_cnt;
149		uint64_t ATTRIBUTE_ALIGNED(8) insns, license;
150		uint32_t log_level, log_size;
151		uint64_t ATTRIBUTE_ALIGNED(8) log_buf;
152		uint32_t kern_version;
153	} attr = {};
154
155	if (!size) {
156		printaddr(addr);
157		return RVAL_DECODED | RVAL_FD;
158	}
159	if (size > sizeof(attr))
160		size = sizeof(attr);
161	if (umoven_or_printaddr(tcp, addr, size, &attr))
162		return RVAL_DECODED | RVAL_FD;
163
164	tprints("{prog_type=");
165	printxval(bpf_prog_types, attr.prog_type, "BPF_PROG_TYPE_???");
166	tprintf(", insn_cnt=%u, insns=%#" PRIx64 ", license=",
167		attr.insn_cnt, attr.insns);
168	printstr(tcp, attr.license, -1);
169	tprintf(", log_level=%u, log_size=%u, log_buf=%#" PRIx64 ", kern_version=%u}",
170		attr.log_level, attr.log_size, attr.log_buf, attr.kern_version);
171
172	return RVAL_DECODED | RVAL_FD;
173}
174
175SYS_FUNC(bpf)
176{
177	const int cmd = tcp->u_arg[0];
178	const long addr = tcp->u_arg[1];
179	const unsigned int size = tcp->u_arg[2];
180	int rc = RVAL_DECODED;
181
182	if (entering(tcp)) {
183		printxval(bpf_commands, cmd, "BPF_???");
184		tprints(", ");
185	}
186
187	switch (cmd) {
188	case BPF_MAP_CREATE:
189		rc = bpf_map_create(tcp, addr, size);
190		break;
191	case BPF_MAP_LOOKUP_ELEM:
192		rc = bpf_map_io(tcp, addr, size, "value");
193		break;
194	case BPF_MAP_UPDATE_ELEM:
195		bpf_map_update_elem(tcp, addr, size);
196		break;
197	case BPF_MAP_DELETE_ELEM:
198		bpf_map_delete_elem(tcp, addr, size);
199		break;
200	case BPF_MAP_GET_NEXT_KEY:
201		rc = bpf_map_io(tcp, addr, size, "next_key");
202		break;
203	case BPF_PROG_LOAD:
204		rc = bpf_prog_load(tcp, addr, size);
205		break;
206	default:
207		printaddr(addr);
208		break;
209	}
210
211	if (rc & RVAL_DECODED)
212		tprintf(", %u", size);
213
214	return rc;
215}
216