1 /* 2 * Copyright (c) 2016 Dmitry V. Levin <ldv (at) altlinux.org> 3 * Copyright (c) 2016-2018 The strace developers. 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 #include "number_set.h" 31 #include "filter.h" 32 #include <regex.h> 33 34 static bool 35 qualify_syscall_number(const char *s, struct number_set *set) 36 { 37 int n = string_to_uint(s); 38 if (n < 0) 39 return false; 40 41 bool done = false; 42 43 for (unsigned int p = 0; p < SUPPORTED_PERSONALITIES; ++p) { 44 if ((unsigned) n >= nsyscall_vec[p]) 45 continue; 46 add_number_to_set_array(n, set, p); 47 done = true; 48 } 49 50 return done; 51 } 52 53 static void 54 regerror_msg_and_die(int errcode, const regex_t *preg, 55 const char *str, const char *pattern) 56 { 57 char buf[512]; 58 59 regerror(errcode, preg, buf, sizeof(buf)); 60 error_msg_and_die("%s: %s: %s", str, pattern, buf); 61 } 62 63 static bool 64 qualify_syscall_regex(const char *s, struct number_set *set) 65 { 66 regex_t preg; 67 int rc; 68 69 if ((rc = regcomp(&preg, s, REG_EXTENDED | REG_NOSUB)) != 0) 70 regerror_msg_and_die(rc, &preg, "regcomp", s); 71 72 bool found = false; 73 74 for (unsigned int p = 0; p < SUPPORTED_PERSONALITIES; ++p) { 75 for (unsigned int i = 0; i < nsyscall_vec[p]; ++i) { 76 if (!sysent_vec[p][i].sys_name) 77 continue; 78 rc = regexec(&preg, sysent_vec[p][i].sys_name, 79 0, NULL, 0); 80 if (rc == REG_NOMATCH) 81 continue; 82 else if (rc) 83 regerror_msg_and_die(rc, &preg, "regexec", s); 84 add_number_to_set_array(i, set, p); 85 found = true; 86 } 87 } 88 89 regfree(&preg); 90 return found; 91 } 92 93 static unsigned int 94 lookup_class(const char *s) 95 { 96 static const struct { 97 const char *name; 98 unsigned int value; 99 } syscall_class[] = { 100 { "%desc", TRACE_DESC }, 101 { "%file", TRACE_FILE }, 102 { "%memory", TRACE_MEMORY }, 103 { "%process", TRACE_PROCESS }, 104 { "%signal", TRACE_SIGNAL }, 105 { "%ipc", TRACE_IPC }, 106 { "%network", TRACE_NETWORK }, 107 { "%stat", TRACE_STAT }, 108 { "%lstat", TRACE_LSTAT }, 109 { "%fstat", TRACE_FSTAT }, 110 { "%%stat", TRACE_STAT_LIKE }, 111 { "%statfs", TRACE_STATFS }, 112 { "%fstatfs", TRACE_FSTATFS }, 113 { "%%statfs", TRACE_STATFS_LIKE }, 114 { "%pure", TRACE_PURE }, 115 /* legacy class names */ 116 { "desc", TRACE_DESC }, 117 { "file", TRACE_FILE }, 118 { "memory", TRACE_MEMORY }, 119 { "process", TRACE_PROCESS }, 120 { "signal", TRACE_SIGNAL }, 121 { "ipc", TRACE_IPC }, 122 { "network", TRACE_NETWORK }, 123 }; 124 125 for (unsigned int i = 0; i < ARRAY_SIZE(syscall_class); ++i) { 126 if (strcmp(s, syscall_class[i].name) == 0) 127 return syscall_class[i].value; 128 } 129 130 return 0; 131 } 132 133 static bool 134 qualify_syscall_class(const char *s, struct number_set *set) 135 { 136 const unsigned int n = lookup_class(s); 137 if (!n) 138 return false; 139 140 for (unsigned int p = 0; p < SUPPORTED_PERSONALITIES; ++p) { 141 for (unsigned int i = 0; i < nsyscall_vec[p]; ++i) { 142 if (sysent_vec[p][i].sys_name && 143 (sysent_vec[p][i].sys_flags & n) == n) 144 add_number_to_set_array(i, set, p); 145 } 146 } 147 148 return true; 149 } 150 151 kernel_long_t 152 scno_by_name(const char *s, unsigned int p, kernel_long_t start) 153 { 154 if (p >= SUPPORTED_PERSONALITIES) 155 return -1; 156 157 for (kernel_ulong_t i = start; i < nsyscall_vec[p]; ++i) { 158 if (sysent_vec[p][i].sys_name && 159 strcmp(s, sysent_vec[p][i].sys_name) == 0) 160 return i; 161 } 162 163 return -1; 164 } 165 166 static bool 167 qualify_syscall_name(const char *s, struct number_set *set) 168 { 169 bool found = false; 170 171 for (unsigned int p = 0; p < SUPPORTED_PERSONALITIES; ++p) { 172 for (kernel_long_t scno = 0; 173 (scno = scno_by_name(s, p, scno)) >= 0; 174 ++scno) { 175 add_number_to_set_array(scno, set, p); 176 found = true; 177 } 178 } 179 180 return found; 181 } 182 183 static bool 184 qualify_syscall(const char *token, struct number_set *set) 185 { 186 bool ignore_fail = false; 187 188 while (*token == '?') { 189 token++; 190 ignore_fail = true; 191 } 192 if (*token >= '0' && *token <= '9') 193 return qualify_syscall_number(token, set) || ignore_fail; 194 if (*token == '/') 195 return qualify_syscall_regex(token + 1, set) || ignore_fail; 196 return qualify_syscall_class(token, set) 197 || qualify_syscall_name(token, set) 198 || ignore_fail; 199 } 200 201 /* 202 * Add syscall numbers to SETs for each supported personality 203 * according to STR specification. 204 */ 205 void 206 qualify_syscall_tokens(const char *const str, struct number_set *const set) 207 { 208 /* Clear all sets. */ 209 clear_number_set_array(set, SUPPORTED_PERSONALITIES); 210 211 /* 212 * Each leading ! character means inversion 213 * of the remaining specification. 214 */ 215 const char *s = str; 216 while (*s == '!') { 217 invert_number_set_array(set, SUPPORTED_PERSONALITIES); 218 ++s; 219 } 220 221 if (strcmp(s, "none") == 0) { 222 /* 223 * No syscall numbers are added to sets. 224 * Subsequent is_number_in_set* invocations 225 * will return set[p]->not. 226 */ 227 return; 228 } else if (strcmp(s, "all") == 0) { 229 /* "all" == "!none" */ 230 invert_number_set_array(set, SUPPORTED_PERSONALITIES); 231 return; 232 } 233 234 /* 235 * Split the string into comma separated tokens. 236 * For each token, call qualify_syscall that will take care 237 * if adding appropriate syscall numbers to sets. 238 * The absence of tokens or a negative return code 239 * from qualify_syscall is a fatal error. 240 */ 241 char *copy = xstrdup(s); 242 char *saveptr = NULL; 243 bool done = false; 244 245 for (const char *token = strtok_r(copy, ",", &saveptr); 246 token; token = strtok_r(NULL, ",", &saveptr)) { 247 done = qualify_syscall(token, set); 248 if (!done) 249 error_msg_and_die("invalid system call '%s'", token); 250 } 251 252 free(copy); 253 254 if (!done) 255 error_msg_and_die("invalid system call '%s'", str); 256 } 257 258 /* 259 * Add numbers to SET according to STR specification. 260 */ 261 void 262 qualify_tokens(const char *const str, struct number_set *const set, 263 string_to_uint_func func, const char *const name) 264 { 265 /* Clear the set. */ 266 clear_number_set_array(set, 1); 267 268 /* 269 * Each leading ! character means inversion 270 * of the remaining specification. 271 */ 272 const char *s = str; 273 while (*s == '!') { 274 invert_number_set_array(set, 1); 275 ++s; 276 } 277 278 if (strcmp(s, "none") == 0) { 279 /* 280 * No numbers are added to the set. 281 * Subsequent is_number_in_set* invocations 282 * will return set->not. 283 */ 284 return; 285 } else if (strcmp(s, "all") == 0) { 286 /* "all" == "!none" */ 287 invert_number_set_array(set, 1); 288 return; 289 } 290 291 /* 292 * Split the string into comma separated tokens. 293 * For each token, find out the corresponding number 294 * by calling FUNC, and add that number to the set. 295 * The absence of tokens or a negative answer 296 * from FUNC is a fatal error. 297 */ 298 char *copy = xstrdup(s); 299 char *saveptr = NULL; 300 int number = -1; 301 302 for (const char *token = strtok_r(copy, ",", &saveptr); 303 token; token = strtok_r(NULL, ",", &saveptr)) { 304 number = func(token); 305 if (number < 0) 306 error_msg_and_die("invalid %s '%s'", name, token); 307 308 add_number_to_set(number, set); 309 } 310 311 free(copy); 312 313 if (number < 0) 314 error_msg_and_die("invalid %s '%s'", name, str); 315 } 316
