1 /*
2 * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
3 * Copyright (c) 2017 Quentin Monnet <quentin.monnet@6wind.com>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include "defs.h"
30
31 #ifdef HAVE_LINUX_BPF_H
32 # include <linux/bpf.h>
33 #endif
34
35 #include "xlat/bpf_commands.h"
36 #include "xlat/bpf_map_types.h"
37 #include "xlat/bpf_prog_types.h"
38 #include "xlat/bpf_map_update_elem_flags.h"
39 #include "xlat/bpf_attach_type.h"
40
41 static int
bpf_map_create(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size)42 bpf_map_create(struct tcb *const tcp, const kernel_ulong_t addr,
43 unsigned int size)
44 {
45 struct {
46 uint32_t map_type, key_size, value_size, max_entries;
47 } attr = {};
48
49 if (!size) {
50 printaddr(addr);
51 return RVAL_DECODED | RVAL_FD;
52 }
53 if (size > sizeof(attr))
54 size = sizeof(attr);
55 if (umoven_or_printaddr(tcp, addr, size, &attr))
56 return RVAL_DECODED | RVAL_FD;
57
58 tprints("{map_type=");
59 printxval(bpf_map_types, attr.map_type, "BPF_MAP_TYPE_???");
60 tprintf(", key_size=%u, value_size=%u, max_entries=%u}",
61 attr.key_size, attr.value_size, attr.max_entries);
62
63 return RVAL_DECODED | RVAL_FD;
64 }
65
66 static void
bpf_map_update_elem(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size)67 bpf_map_update_elem(struct tcb *const tcp, const kernel_ulong_t addr,
68 unsigned int size)
69 {
70 struct {
71 uint32_t map_fd;
72 uint64_t ATTRIBUTE_ALIGNED(8) key;
73 uint64_t ATTRIBUTE_ALIGNED(8) value;
74 uint64_t flags;
75 } attr = {};
76
77 if (!size) {
78 printaddr(addr);
79 return;
80 }
81 if (size > sizeof(attr))
82 size = sizeof(attr);
83 if (umoven_or_printaddr(tcp, addr, size, &attr))
84 return;
85
86 tprints("{map_fd=");
87 printfd(tcp, attr.map_fd);
88 tprintf(", key=%#" PRIx64 ", value=%#" PRIx64 ", flags=",
89 attr.key, attr.value);
90 printxval64(bpf_map_update_elem_flags, attr.flags, "BPF_???");
91 tprints("}");
92 }
93
94 static void
bpf_map_delete_elem(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size)95 bpf_map_delete_elem(struct tcb *const tcp, const kernel_ulong_t addr,
96 unsigned int size)
97 {
98 struct {
99 uint32_t map_fd;
100 uint64_t ATTRIBUTE_ALIGNED(8) key;
101 } attr = {};
102
103 if (!size) {
104 printaddr(addr);
105 return;
106 }
107 if (size > sizeof(attr))
108 size = sizeof(attr);
109 if (umoven_or_printaddr(tcp, addr, size, &attr))
110 return;
111
112 tprints("{map_fd=");
113 printfd(tcp, attr.map_fd);
114 tprintf(", key=%#" PRIx64 "}", attr.key);
115 }
116
117 static int
bpf_map_io(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size,const char * const text)118 bpf_map_io(struct tcb *const tcp, const kernel_ulong_t addr, unsigned int size,
119 const char *const text)
120 {
121 struct bpf_io_elem_struct {
122 uint32_t map_fd;
123 uint64_t ATTRIBUTE_ALIGNED(8) key;
124 uint64_t ATTRIBUTE_ALIGNED(8) value;
125 } attr = {};
126
127 if (exiting(tcp)) {
128 if (!syserror(tcp) && !umove_or_printaddr(tcp, addr, &attr))
129 tprintf(", %s=%#" PRIx64, text, attr.value);
130 tprints("}");
131 return RVAL_DECODED;
132 }
133
134 if (!size) {
135 printaddr(addr);
136 return RVAL_DECODED;
137 }
138 if (size > sizeof(attr))
139 size = sizeof(attr);
140 if (umoven_or_printaddr(tcp, addr, size, &attr))
141 return RVAL_DECODED;
142
143 tprints("{map_fd=");
144 printfd(tcp, attr.map_fd);
145 tprintf(", key=%#" PRIx64, attr.key);
146
147 return 0;
148 }
149
150 static int
bpf_prog_load(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size)151 bpf_prog_load(struct tcb *const tcp, const kernel_ulong_t addr,
152 unsigned int size)
153 {
154 struct {
155 uint32_t prog_type, insn_cnt;
156 uint64_t ATTRIBUTE_ALIGNED(8) insns, license;
157 uint32_t log_level, log_size;
158 uint64_t ATTRIBUTE_ALIGNED(8) log_buf;
159 uint32_t kern_version;
160 } attr = {};
161
162 if (!size) {
163 printaddr(addr);
164 return RVAL_DECODED | RVAL_FD;
165 }
166 if (size > sizeof(attr))
167 size = sizeof(attr);
168 if (umoven_or_printaddr(tcp, addr, size, &attr))
169 return RVAL_DECODED | RVAL_FD;
170
171 tprints("{prog_type=");
172 printxval(bpf_prog_types, attr.prog_type, "BPF_PROG_TYPE_???");
173 tprintf(", insn_cnt=%u, insns=%#" PRIx64 ", license=",
174 attr.insn_cnt, attr.insns);
175 printstr(tcp, attr.license);
176 tprintf(", log_level=%u, log_size=%u, log_buf=%#" PRIx64 ", kern_version=%u}",
177 attr.log_level, attr.log_size, attr.log_buf, attr.kern_version);
178
179 return RVAL_DECODED | RVAL_FD;
180 }
181
182 static int
bpf_obj_manage(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size)183 bpf_obj_manage(struct tcb *const tcp, const kernel_ulong_t addr,
184 unsigned int size)
185 {
186 struct {
187 uint64_t ATTRIBUTE_ALIGNED(8) pathname;
188 uint32_t bpf_fd;
189 } attr = {};
190
191 if (!size) {
192 printaddr(addr);
193 return RVAL_DECODED | RVAL_FD;
194 }
195 if (size > sizeof(attr))
196 size = sizeof(attr);
197 if (umoven_or_printaddr(tcp, addr, size, &attr))
198 return RVAL_DECODED | RVAL_FD;
199
200 tprintf("{pathname=");
201 printpath(tcp, attr.pathname);
202 tprints(", bpf_fd=");
203 printfd(tcp, attr.bpf_fd);
204 tprintf("}");
205
206 return RVAL_DECODED | RVAL_FD;
207 }
208
209 static int
bpf_prog_attach_detach(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size,bool print_attach_bpf_fd)210 bpf_prog_attach_detach(struct tcb *const tcp, const kernel_ulong_t addr,
211 unsigned int size, bool print_attach_bpf_fd)
212 {
213 struct {
214 uint32_t target_fd, attach_bpf_fd, attach_type;
215 } attr = {};
216
217 if (!size) {
218 printaddr(addr);
219 return RVAL_DECODED;
220 }
221 if (size > sizeof(attr))
222 size = sizeof(attr);
223 if (umoven_or_printaddr(tcp, addr, size, &attr))
224 return RVAL_DECODED;
225
226 tprintf("{target_fd=");
227 printfd(tcp, attr.target_fd);
228 if (print_attach_bpf_fd) {
229 tprintf(", attach_bpf_fd=");
230 printfd(tcp, attr.attach_bpf_fd);
231 }
232 tprintf(", attach_type=");
233 printxval(bpf_attach_type, attr.attach_type, "BPF_???");
234 tprintf("}");
235
236 return RVAL_DECODED;
237 }
238
239 static int
bpf_prog_attach(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size)240 bpf_prog_attach(struct tcb *const tcp, const kernel_ulong_t addr,
241 unsigned int size)
242 {
243 return bpf_prog_attach_detach(tcp, addr, size, true);
244 }
245
246 static int
bpf_prog_detach(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int size)247 bpf_prog_detach(struct tcb *const tcp, const kernel_ulong_t addr,
248 unsigned int size)
249 {
250 return bpf_prog_attach_detach(tcp, addr, size, false);
251 }
252
SYS_FUNC(bpf)253 SYS_FUNC(bpf)
254 {
255 const unsigned int cmd = tcp->u_arg[0];
256 const kernel_ulong_t addr = tcp->u_arg[1];
257 const unsigned int size = tcp->u_arg[2];
258 int rc = RVAL_DECODED;
259
260 if (entering(tcp)) {
261 printxval(bpf_commands, cmd, "BPF_???");
262 tprints(", ");
263 }
264
265 switch (cmd) {
266 case BPF_MAP_CREATE:
267 rc = bpf_map_create(tcp, addr, size);
268 break;
269 case BPF_MAP_LOOKUP_ELEM:
270 rc = bpf_map_io(tcp, addr, size, "value");
271 break;
272 case BPF_MAP_UPDATE_ELEM:
273 bpf_map_update_elem(tcp, addr, size);
274 break;
275 case BPF_MAP_DELETE_ELEM:
276 bpf_map_delete_elem(tcp, addr, size);
277 break;
278 case BPF_MAP_GET_NEXT_KEY:
279 rc = bpf_map_io(tcp, addr, size, "next_key");
280 break;
281 case BPF_PROG_LOAD:
282 rc = bpf_prog_load(tcp, addr, size);
283 break;
284 case BPF_OBJ_PIN:
285 rc = bpf_obj_manage(tcp, addr, size);
286 break;
287 case BPF_OBJ_GET:
288 rc = bpf_obj_manage(tcp, addr, size);
289 break;
290 case BPF_PROG_ATTACH:
291 rc = bpf_prog_attach(tcp, addr, size);
292 break;
293 case BPF_PROG_DETACH:
294 rc = bpf_prog_detach(tcp, addr, size);
295 break;
296 default:
297 printaddr(addr);
298 break;
299 }
300
301 if (rc & RVAL_DECODED)
302 tprintf(", %u", size);
303
304 return rc;
305 }
306