src/libsystemd/sd-bus/bus-internal.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2013 Lennart Poettering
   6 ***/
   7
   8 #include "alloc-util.h"
   9 #include "bus-internal.h"
  10 #include "bus-message.h"
  11 #include "hexdecoct.h"
  12 #include "string-util.h"
  13
  14 bool object_path_is_valid(const char *p) {
  15         const char *q;
  16         bool slash;
  17
  18         if (!p)
  19                 return false;
  20
  21         if (p[0] != '/')
  22                 return false;
  23
  24         if (p[1] == 0)
  25                 return true;
  26
  27         for (slash = true, q = p+1; *q; q++)
  28                 if (*q == '/') {
  29                         if (slash)
  30                                 return false;
  31
  32                         slash = true;
  33                 } else {
  34                         bool good;
  35
  36                         good =
  37                                 (*q >= 'a' && *q <= 'z') ||
  38                                 (*q >= 'A' && *q <= 'Z') ||
  39                                 (*q >= '0' && *q <= '9') ||
  40                                 *q == '_';
  41
  42                         if (!good)
  43                                 return false;
  44
  45                         slash = false;
  46                 }
  47
  48         if (slash)
  49                 return false;
  50
  51         return true;
  52 }
  53
  54 char* object_path_startswith(const char *a, const char *b) {
  55         const char *p;
  56
  57         if (!object_path_is_valid(a) ||
  58             !object_path_is_valid(b))
  59                 return NULL;
  60
  61         if (streq(b, "/"))
  62                 return (char*) a + 1;
  63
  64         p = startswith(a, b);
  65         if (!p)
  66                 return NULL;
  67
  68         if (*p == 0)
  69                 return (char*) p;
  70
  71         if (*p == '/')
  72                 return (char*) p + 1;
  73
  74         return NULL;
  75 }
  76
  77 bool interface_name_is_valid(const char *p) {
  78         const char *q;
  79         bool dot, found_dot = false;
  80
  81         if (isempty(p))
  82                 return false;
  83
  84         for (dot = true, q = p; *q; q++)
  85                 if (*q == '.') {
  86                         if (dot)
  87                                 return false;
  88
  89                         found_dot = dot = true;
  90                 } else {
  91                         bool good;
  92
  93                         good =
  94                                 (*q >= 'a' && *q <= 'z') ||
  95                                 (*q >= 'A' && *q <= 'Z') ||
  96                                 (!dot && *q >= '0' && *q <= '9') ||
  97                                 *q == '_';
  98
  99                         if (!good)
 100                                 return false;
 101
 102                         dot = false;
 103                 }
 104
 105         if (q - p > 255)
 106                 return false;
 107
 108         if (dot)
 109                 return false;
 110
 111         if (!found_dot)
 112                 return false;
 113
 114         return true;
 115 }
 116
 117 bool service_name_is_valid(const char *p) {
 118         const char *q;
 119         bool dot, found_dot = false, unique;
 120
 121         if (isempty(p))
 122                 return false;
 123
 124         unique = p[0] == ':';
 125
 126         for (dot = true, q = unique ? p+1 : p; *q; q++)
 127                 if (*q == '.') {
 128                         if (dot)
 129                                 return false;
 130
 131                         found_dot = dot = true;
 132                 } else {
 133                         bool good;
 134
 135                         good =
 136                                 (*q >= 'a' && *q <= 'z') ||
 137                                 (*q >= 'A' && *q <= 'Z') ||
 138                                 ((!dot || unique) && *q >= '0' && *q <= '9') ||
 139                                 IN_SET(*q, '_', '-');
 140
 141                         if (!good)
 142                                 return false;
 143
 144                         dot = false;
 145                 }
 146
 147         if (q - p > 255)
 148                 return false;
 149
 150         if (dot)
 151                 return false;
 152
 153         if (!found_dot)
 154                 return false;
 155
 156         return true;
 157 }
 158
 159 char* service_name_startswith(const char *a, const char *b) {
 160         const char *p;
 161
 162         if (!service_name_is_valid(a) ||
 163             !service_name_is_valid(b))
 164                 return NULL;
 165
 166         p = startswith(a, b);
 167         if (!p)
 168                 return NULL;
 169
 170         if (*p == 0)
 171                 return (char*) p;
 172
 173         if (*p == '.')
 174                 return (char*) p + 1;
 175
 176         return NULL;
 177 }
 178
 179 bool member_name_is_valid(const char *p) {
 180         const char *q;
 181
 182         if (isempty(p))
 183                 return false;
 184
 185         for (q = p; *q; q++) {
 186                 bool good;
 187
 188                 good =
 189                         (*q >= 'a' && *q <= 'z') ||
 190                         (*q >= 'A' && *q <= 'Z') ||
 191                         (*q >= '0' && *q <= '9') ||
 192                         *q == '_';
 193
 194                 if (!good)
 195                         return false;
 196         }
 197
 198         if (q - p > 255)
 199                 return false;
 200
 201         return true;
 202 }
 203
 204 /*
 205  * Complex pattern match
 206  * This checks whether @a is a 'complex-prefix' of @b, or @b is a
 207  * 'complex-prefix' of @a, based on strings that consist of labels with @c as
 208  * spearator. This function returns true if:
 209  *   - both strings are equal
 210  *   - either is a prefix of the other and ends with @c
 211  * The second rule makes sure that either string needs to be fully included in
 212  * the other, and the string which is considered the prefix needs to end with a
 213  * separator.
 214  */
 215 static bool complex_pattern_check(char c, const char *a, const char *b) {
 216         bool separator = false;
 217
 218         if (!a && !b)
 219                 return true;
 220
 221         if (!a || !b)
 222                 return false;
 223
 224         for (;;) {
 225                 if (*a != *b)
 226                         return (separator && (*a == 0 || *b == 0));
 227
 228                 if (*a == 0)
 229                         return true;
 230
 231                 separator = *a == c;
 232
 233                 a++, b++;
 234         }
 235 }
 236
 237 bool namespace_complex_pattern(const char *pattern, const char *value) {
 238         return complex_pattern_check('.', pattern, value);
 239 }
 240
 241 bool path_complex_pattern(const char *pattern, const char *value) {
 242         return complex_pattern_check('/', pattern, value);
 243 }
 244
 245 /*
 246  * Simple pattern match
 247  * This checks whether @a is a 'simple-prefix' of @b, based on strings that
 248  * consist of labels with @c as separator. This function returns true, if:
 249  *   - if @a and @b are equal
 250  *   - if @a is a prefix of @b, and the first following character in @b (or the
 251  *     last character in @a) is @c
 252  * The second rule basically makes sure that if @a is a prefix of @b, then @b
 253  * must follow with a new label separated by @c. It cannot extend the label.
 254  */
 255 static bool simple_pattern_check(char c, const char *a, const char *b) {
 256         bool separator = false;
 257
 258         if (!a && !b)
 259                 return true;
 260
 261         if (!a || !b)
 262                 return false;
 263
 264         for (;;) {
 265                 if (*a != *b)
 266                         return *a == 0 && (*b == c || separator);
 267
 268                 if (*a == 0)
 269                         return true;
 270
 271                 separator = *a == c;
 272
 273                 a++, b++;
 274         }
 275 }
 276
 277 bool namespace_simple_pattern(const char *pattern, const char *value) {
 278         return simple_pattern_check('.', pattern, value);
 279 }
 280
 281 bool path_simple_pattern(const char *pattern, const char *value) {
 282         return simple_pattern_check('/', pattern, value);
 283 }
 284
 285 int bus_message_type_from_string(const char *s, uint8_t *u) {
 286         if (streq(s, "signal"))
 287                 *u = SD_BUS_MESSAGE_SIGNAL;
 288         else if (streq(s, "method_call"))
 289                 *u = SD_BUS_MESSAGE_METHOD_CALL;
 290         else if (streq(s, "error"))
 291                 *u = SD_BUS_MESSAGE_METHOD_ERROR;
 292         else if (streq(s, "method_return"))
 293                 *u = SD_BUS_MESSAGE_METHOD_RETURN;
 294         else
 295                 return -EINVAL;
 296
 297         return 0;
 298 }
 299
 300 const char *bus_message_type_to_string(uint8_t u) {
 301         if (u == SD_BUS_MESSAGE_SIGNAL)
 302                 return "signal";
 303         else if (u == SD_BUS_MESSAGE_METHOD_CALL)
 304                 return "method_call";
 305         else if (u == SD_BUS_MESSAGE_METHOD_ERROR)
 306                 return "error";
 307         else if (u == SD_BUS_MESSAGE_METHOD_RETURN)
 308                  return "method_return";
 309         else
 310                 return NULL;
 311 }
 312
 313 char *bus_address_escape(const char *v) {
 314         const char *a;
 315         char *r, *b;
 316
 317         r = new(char, strlen(v)*3+1);
 318         if (!r)
 319                 return NULL;
 320
 321         for (a = v, b = r; *a; a++) {
 322
 323                 if ((*a >= '0' && *a <= '9') ||
 324                     (*a >= 'a' && *a <= 'z') ||
 325                     (*a >= 'A' && *a <= 'Z') ||
 326                     strchr("_-/.", *a))
 327                         *(b++) = *a;
 328                 else {
 329                         *(b++) = '%';
 330                         *(b++) = hexchar(*a >> 4);
 331                         *(b++) = hexchar(*a & 0xF);
 332                 }
 333         }
 334
 335         *b = 0;
 336         return r;
 337 }
 338
 339 int bus_maybe_reply_error(sd_bus_message *m, int r, sd_bus_error *error) {
 340         assert(m);
 341
 342         if (r < 0) {
 343                 if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
 344                         sd_bus_reply_method_errno(m, r, error);
 345
 346         } else if (sd_bus_error_is_set(error)) {
 347                 if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
 348                         sd_bus_reply_method_error(m, error);
 349         } else
 350                 return r;
 351
 352         log_debug("Failed to process message type=%s sender=%s destination=%s path=%s interface=%s member=%s cookie=%" PRIu64 " reply_cookie=%" PRIu64 " signature=%s error-name=%s error-message=%s: %s",
 353                   bus_message_type_to_string(m->header->type),
 354                   strna(sd_bus_message_get_sender(m)),
 355                   strna(sd_bus_message_get_destination(m)),
 356                   strna(sd_bus_message_get_path(m)),
 357                   strna(sd_bus_message_get_interface(m)),
 358                   strna(sd_bus_message_get_member(m)),
 359                   BUS_MESSAGE_COOKIE(m),
 360                   m->reply_cookie,
 361                   strna(m->root_container.signature),
 362                   strna(m->error.name),
 363                   strna(m->error.message),
 364                   bus_error_message(error, r));
 365
 366         return 1;
 367 }