1 /* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6 #include "util.h"
7
8 #include <ctype.h>
9 #include <errno.h>
10 #include <limits.h>
11 #include <stdarg.h>
12 #include <stdint.h>
13 #include <stdio.h>
14 #include <string.h>
15
16 #include "libconstants.h"
17 #include "libsyscalls.h"
18
19 /*
20 * These are syscalls used by the syslog() C library call. You can find them
21 * by running a simple test program. See below for x86_64 behavior:
22 * $ cat test.c
23 * #include <syslog.h>
24 * main() { syslog(0, "foo"); }
25 * $ gcc test.c -static
26 * $ strace ./a.out
27 * ...
28 * socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 3 <- look for socket connection
29 * connect(...) <- important
30 * sendto(...) <- important
31 * exit_group(0) <- finish!
32 */
33 #if defined(__x86_64__)
34 #if defined(__ANDROID__)
35 const char *log_syscalls[] = {"socket", "connect", "fcntl", "writev"};
36 #else
37 const char *log_syscalls[] = {"socket", "connect", "sendto"};
38 #endif
39 #elif defined(__i386__)
40 #if defined(__ANDROID__)
41 const char *log_syscalls[] = {"socketcall", "writev", "fcntl64",
42 "clock_gettime"};
43 #else
44 const char *log_syscalls[] = {"socketcall", "time"};
45 #endif
46 #elif defined(__arm__)
47 #if defined(__ANDROID__)
48 const char *log_syscalls[] = {"clock_gettime", "connect", "fcntl64", "socket",
49 "writev"};
50 #else
51 const char *log_syscalls[] = {"socket", "connect", "gettimeofday", "send"};
52 #endif
53 #elif defined(__aarch64__)
54 #if defined(__ANDROID__)
55 const char *log_syscalls[] = {"connect", "fcntl", "sendto", "socket", "writev"};
56 #else
57 const char *log_syscalls[] = {"socket", "connect", "send"};
58 #endif
59 #elif defined(__powerpc__) || defined(__ia64__) || defined(__hppa__) || \
60 defined(__sparc__) || defined(__mips__)
61 const char *log_syscalls[] = {"socket", "connect", "send"};
62 #else
63 #error "Unsupported platform"
64 #endif
65
66 const size_t log_syscalls_len = ARRAY_SIZE(log_syscalls);
67
68 /* clang-format off */
69 static struct logging_config_t {
70 /* The logging system to use. The default is syslog. */
71 enum logging_system_t logger;
72
73 /* File descriptor to log to. Only used when logger is LOG_TO_FD. */
74 int fd;
75
76 /* Minimum priority to log. Only used when logger is LOG_TO_FD. */
77 int min_priority;
78 } logging_config = {
79 .logger = LOG_TO_SYSLOG,
80 };
81 /* clang-format on */
82
do_log(int priority,const char * format,...)83 void do_log(int priority, const char *format, ...)
84 {
85 if (logging_config.logger == LOG_TO_SYSLOG) {
86 va_list args;
87 va_start(args, format);
88 vsyslog(priority, format, args);
89 va_end(args);
90 return;
91 }
92
93 if (logging_config.min_priority < priority)
94 return;
95
96 va_list args;
97 va_start(args, format);
98 vdprintf(logging_config.fd, format, args);
99 va_end(args);
100 dprintf(logging_config.fd, "\n");
101 }
102
lookup_syscall(const char * name)103 int lookup_syscall(const char *name)
104 {
105 const struct syscall_entry *entry = syscall_table;
106 for (; entry->name && entry->nr >= 0; ++entry)
107 if (!strcmp(entry->name, name))
108 return entry->nr;
109 return -1;
110 }
111
lookup_syscall_name(int nr)112 const char *lookup_syscall_name(int nr)
113 {
114 const struct syscall_entry *entry = syscall_table;
115 for (; entry->name && entry->nr >= 0; ++entry)
116 if (entry->nr == nr)
117 return entry->name;
118 return NULL;
119 }
120
parse_single_constant(char * constant_str,char ** endptr)121 long int parse_single_constant(char *constant_str, char **endptr)
122 {
123 const struct constant_entry *entry = constant_table;
124 long int res = 0;
125 for (; entry->name; ++entry) {
126 if (!strcmp(entry->name, constant_str)) {
127 if (endptr)
128 *endptr = constant_str + strlen(constant_str);
129
130 return entry->value;
131 }
132 }
133
134 errno = 0;
135 res = strtol(constant_str, endptr, 0);
136 if (errno == ERANGE) {
137 if (res == LONG_MAX) {
138 /* See if the constant fits in an unsigned long int. */
139 errno = 0;
140 res = strtoul(constant_str, endptr, 0);
141 if (errno == ERANGE) {
142 /*
143 * On unsigned overflow, use the same convention
144 * as when strtol(3) finds no digits: set
145 * |*endptr| to |constant_str| and return 0.
146 */
147 warn("unsigned overflow: '%s'", constant_str);
148 *endptr = constant_str;
149 res = 0;
150 }
151 } else if (res == LONG_MIN) {
152 /*
153 * Same for signed underflow: set |*endptr| to
154 * |constant_str| and return 0.
155 */
156 warn("signed underflow: '%s'", constant_str);
157 *endptr = constant_str;
158 res = 0;
159 }
160 }
161 return res;
162 }
163
parse_constant(char * constant_str,char ** endptr)164 long int parse_constant(char *constant_str, char **endptr)
165 {
166 long int value = 0;
167 char *group, *lastpos = constant_str;
168 char *original_constant_str = constant_str;
169
170 /*
171 * Try to parse constants separated by pipes. Note that since
172 * |constant_str| is an atom, there can be no spaces between the
173 * constant and the pipe. Constants can be either a named constant
174 * defined in libconstants.gen.c or a number parsed with strtol(3).
175 *
176 * If there is an error parsing any of the constants, the whole process
177 * fails.
178 */
179 while ((group = tokenize(&constant_str, "|")) != NULL) {
180 char *end = group;
181 value |= parse_single_constant(group, &end);
182 if (end == group) {
183 lastpos = original_constant_str;
184 value = 0;
185 break;
186 }
187 lastpos = end;
188 }
189 if (endptr)
190 *endptr = lastpos;
191 return value;
192 }
193
194 /*
195 * parse_size, specified as a string with a decimal number in bytes,
196 * possibly with one 1-character suffix like "10K" or "6G".
197 * Assumes both pointers are non-NULL.
198 *
199 * Returns 0 on success, negative errno on failure.
200 * Only writes to result on success.
201 */
parse_size(size_t * result,const char * sizespec)202 int parse_size(size_t *result, const char *sizespec)
203 {
204 const char prefixes[] = "KMGTPE";
205 size_t i, multiplier = 1, nsize, size = 0;
206 unsigned long long parsed;
207 const size_t len = strlen(sizespec);
208 char *end;
209
210 if (len == 0 || sizespec[0] == '-')
211 return -EINVAL;
212
213 for (i = 0; i < sizeof(prefixes); ++i) {
214 if (sizespec[len - 1] == prefixes[i]) {
215 #if __WORDSIZE == 32
216 if (i >= 3)
217 return -ERANGE;
218 #endif
219 multiplier = 1024;
220 while (i-- > 0)
221 multiplier *= 1024;
222 break;
223 }
224 }
225
226 /* We only need size_t but strtoul(3) is too small on IL32P64. */
227 parsed = strtoull(sizespec, &end, 10);
228 if (parsed == ULLONG_MAX)
229 return -errno;
230 if (parsed >= SIZE_MAX)
231 return -ERANGE;
232 if ((multiplier != 1 && end != sizespec + len - 1) ||
233 (multiplier == 1 && end != sizespec + len))
234 return -EINVAL;
235 size = (size_t)parsed;
236
237 nsize = size * multiplier;
238 if (nsize / multiplier != size)
239 return -ERANGE;
240 *result = nsize;
241 return 0;
242 }
243
strip(char * s)244 char *strip(char *s)
245 {
246 char *end;
247 while (*s && isblank(*s))
248 s++;
249 end = s + strlen(s) - 1;
250 while (end >= s && *end && (isblank(*end) || *end == '\n'))
251 end--;
252 *(end + 1) = '\0';
253 return s;
254 }
255
tokenize(char ** stringp,const char * delim)256 char *tokenize(char **stringp, const char *delim)
257 {
258 char *ret = NULL;
259
260 /* If the string is NULL, there are no tokens to be found. */
261 if (stringp == NULL || *stringp == NULL)
262 return NULL;
263
264 /*
265 * If the delimiter is NULL or empty,
266 * the full string makes up the only token.
267 */
268 if (delim == NULL || *delim == '\0') {
269 ret = *stringp;
270 *stringp = NULL;
271 return ret;
272 }
273
274 char *found = strstr(*stringp, delim);
275 if (!found) {
276 /*
277 * The delimiter was not found, so the full string
278 * makes up the only token, and we're done.
279 */
280 ret = *stringp;
281 *stringp = NULL;
282 } else {
283 /* There's a token here, possibly empty. That's OK. */
284 *found = '\0';
285 ret = *stringp;
286 *stringp = found + strlen(delim);
287 }
288
289 return ret;
290 }
291
path_join(const char * external_path,const char * internal_path)292 char *path_join(const char *external_path, const char *internal_path)
293 {
294 char *path;
295 size_t pathlen;
296
297 /* One extra char for '/' and one for '\0', hence + 2. */
298 pathlen = strlen(external_path) + strlen(internal_path) + 2;
299 path = malloc(pathlen);
300 snprintf(path, pathlen, "%s/%s", external_path, internal_path);
301
302 return path;
303 }
304
consumebytes(size_t length,char ** buf,size_t * buflength)305 void *consumebytes(size_t length, char **buf, size_t *buflength)
306 {
307 char *p = *buf;
308 if (length > *buflength)
309 return NULL;
310 *buf += length;
311 *buflength -= length;
312 return p;
313 }
314
consumestr(char ** buf,size_t * buflength)315 char *consumestr(char **buf, size_t *buflength)
316 {
317 size_t len = strnlen(*buf, *buflength);
318 if (len == *buflength)
319 /* There's no null-terminator. */
320 return NULL;
321 return consumebytes(len + 1, buf, buflength);
322 }
323
init_logging(enum logging_system_t logger,int fd,int min_priority)324 void init_logging(enum logging_system_t logger, int fd, int min_priority)
325 {
326 logging_config.logger = logger;
327 logging_config.fd = fd;
328 logging_config.min_priority = min_priority;
329 }
330