src/utils/unixsock.c

   1 /*
   2  * SysDB - src/utils/unixsock.c
   3  * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
   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  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "utils/error.h"
  33 #include "utils/unixsock.h"
  34
  35 #include <assert.h>
  36 #include <errno.h>
  37
  38 #include <stdarg.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41
  42 #include <string.h>
  43 #include <strings.h>
  44
  45 #include <unistd.h>
  46
  47 #include <sys/socket.h>
  48 #include <sys/un.h>
  49
  50 /*
  51  * private data types
  52  */
  53
  54 struct sdb_unixsock_client {
  55         char *path;
  56         FILE *fh;
  57
  58         int shutdown;
  59 };
  60
  61 #define SDB_SHUT_RD   (1 << SHUT_RD)
  62 #define SDB_SHUT_WR   (1 << SHUT_WR)
  63 #define SDB_SHUT_RDWR (SDB_SHUT_RD | SDB_SHUT_WR)
  64
  65 /*
  66  * private helper functions
  67  */
  68
  69 static int
  70 sdb_unixsock_get_column_count(const char *string, const char *delim)
  71 {
  72         int count = 1;
  73
  74         assert(string);
  75
  76         if ((! delim) || (*string == '\0'))
  77                 return 1;
  78
  79         if ((delim[0] == '\0') || (delim[1] == '\0')) {
  80                 while ((string = strchr(string, (int)delim[0]))) {
  81                         ++string;
  82                         ++count;
  83                 }
  84         }
  85         else {
  86                 while ((string = strpbrk(string, delim))) {
  87                         ++string;
  88                         ++count;
  89                 }
  90         }
  91         return count;
  92 } /* sdb_unixsock_get_column_count */
  93
  94 static int
  95 sdb_unixsock_client_process_one_line(sdb_unixsock_client_t *client,
  96                 char *line, sdb_unixsock_client_data_cb callback,
  97                 sdb_object_t *user_data, const char *delim,
  98                 int column_count, int *types)
  99 {
 100         sdb_data_t data[column_count];
 101         char *orig_line = line;
 102
 103         int i;
 104
 105         assert(column_count > 0);
 106
 107         for (i = 0; i < column_count; ++i) {
 108                 char *next;
 109
 110                 if (! line) { /* this must no happen */
 111                         sdb_log(SDB_LOG_ERR, "unixsock: Unexpected EOL while "
 112                                         "parsing line (expected %i columns delimited by '%s'; "
 113                                         "got %i): %s", column_count, delim,
 114                                         /* last line number */ i, orig_line);
 115                         return -1;
 116                 }
 117
 118                 if ((delim[0] == '\0') || (delim[1] == '\0'))
 119                         next = strchr(line, (int)delim[0]);
 120                 else
 121                         next = strpbrk(line, delim);
 122
 123                 if (next) {
 124                         *next = '\0';
 125                         ++next;
 126                 }
 127
 128                 if (sdb_data_parse(line,
 129                                         types ? types[i] : SDB_TYPE_STRING, &data[i]))
 130                         return -1;
 131
 132                 line = next;
 133         }
 134
 135         if (callback(client, (size_t)column_count, data, user_data))
 136                 return -1;
 137
 138         for (i = 0; i < column_count; ++i)
 139                 sdb_data_free_datum(&data[i]);
 140         return 0;
 141 } /* sdb_unixsock_client_process_one_line */
 142
 143 /*
 144  * public API
 145  */
 146
 147 sdb_unixsock_client_t *
 148 sdb_unixsock_client_create(const char *path)
 149 {
 150         sdb_unixsock_client_t *client;
 151
 152         if (! path)
 153                 return NULL;
 154
 155         client = malloc(sizeof(*client));
 156         if (! client)
 157                 return NULL;
 158         memset(client, 0, sizeof(*client));
 159         client->fh = NULL;
 160
 161         client->path = strdup(path);
 162         if (! client->path) {
 163                 sdb_unixsock_client_destroy(client);
 164                 return NULL;
 165         }
 166
 167         client->shutdown = 0;
 168         return client;
 169 } /* sdb_unixsock_client_create */
 170
 171 int
 172 sdb_unixsock_client_connect(sdb_unixsock_client_t *client)
 173 {
 174         struct sockaddr_un sa;
 175         int fd;
 176
 177         if ((! client) || (! client->path))
 178                 return -1;
 179
 180         memset(&sa, 0, sizeof(sa));
 181
 182         if (client->fh)
 183                 fclose(client->fh);
 184
 185         fd = socket(AF_UNIX, SOCK_STREAM, /* protocol = */ 0);
 186         if (fd < 0) {
 187                 char errbuf[1024];
 188                 sdb_log(SDB_LOG_ERR, "unixsock: Failed to open socket: %s",
 189                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 190                 return -1;
 191         }
 192
 193         sa.sun_family = AF_UNIX;
 194         strncpy(sa.sun_path, client->path, sizeof(sa.sun_path));
 195         sa.sun_path[sizeof(sa.sun_path) - 1] = '\0';
 196
 197         if (connect(fd, (struct sockaddr *)&sa, sizeof(sa))) {
 198                 char errbuf[1024];
 199                 sdb_log(SDB_LOG_ERR, "unixsock: Failed to connect to %s: %s",
 200                                 sa.sun_path, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 201                 close(fd);
 202                 return -1;
 203         }
 204
 205         client->fh = fdopen(fd, "r+");
 206         if (! client->fh) {
 207                 char errbuf[1024];
 208                 sdb_log(SDB_LOG_ERR, "unixsock: Failed to open I/O "
 209                                 "stream for %s: %s", sa.sun_path,
 210                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 211                 close(fd);
 212                 return -1;
 213         }
 214
 215         /* enable line-buffering */
 216         setvbuf(client->fh, NULL, _IOLBF, 0);
 217
 218         client->shutdown = 0;
 219         return 0;
 220 } /* sdb_unixsock_client_connect */
 221
 222 int
 223 sdb_unixsock_client_send(sdb_unixsock_client_t *client,
 224                 const char *msg)
 225 {
 226         int status;
 227
 228         if ((! client) || (! client->fh))
 229                 return -1;
 230
 231         if (client->shutdown & SDB_SHUT_WR) /* reconnect */
 232                 sdb_unixsock_client_connect(client);
 233
 234         status = fprintf(client->fh, "%s\r\n", msg);
 235         if (status < 0) {
 236                 char errbuf[1024];
 237                 sdb_log(SDB_LOG_ERR, "unixsock: Failed to write to "
 238                                 "socket (%s): %s", client->path,
 239                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 240                 return status;
 241         }
 242         return status;
 243 } /* sdb_unixsock_client_send */
 244
 245 char *
 246 sdb_unixsock_client_recv(sdb_unixsock_client_t *client,
 247                 char *buffer, size_t buflen)
 248 {
 249         char *tmp;
 250
 251         if ((! client) || (! client->fh) || (! buffer))
 252                 return NULL;
 253
 254         if (client->shutdown & SDB_SHUT_RD) /* reconnect */
 255                 sdb_unixsock_client_connect(client);
 256
 257         tmp = NULL;
 258         while (tmp == NULL) {
 259                 errno = 0;
 260                 tmp = fgets(buffer, (int)buflen - 1, client->fh);
 261                 if (! tmp) {
 262                         if ((errno == EAGAIN) || (errno == EINTR))
 263                                 continue;
 264
 265                         if (! feof(client->fh)) {
 266                                 char errbuf[1024];
 267                                 sdb_log(SDB_LOG_ERR, "unixsock: Failed to read "
 268                                                 "from socket (%s): %s", client->path,
 269                                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 270                         }
 271                         return NULL;
 272                 }
 273         }
 274         buffer[buflen - 1] = '\0';
 275
 276         buflen = strlen(buffer);
 277         while (buflen && ((buffer[buflen - 1] == '\n') || (buffer[buflen - 1] == '\r'))) {
 278                 buffer[buflen - 1] = '\0';
 279                 --buflen;
 280         }
 281         return buffer;
 282 } /* sdb_unixsock_client_recv */
 283
 284 int
 285 sdb_unixsock_client_process_lines(sdb_unixsock_client_t *client,
 286                 sdb_unixsock_client_data_cb callback, sdb_object_t *user_data,
 287                 long int max_lines, const char *delim, int n_cols, ...)
 288 {
 289         int *types = NULL;
 290         int success = 0;
 291
 292         if ((! client) || (! client->fh) || (! callback))
 293                 return -1;
 294
 295         if (n_cols > 0) {
 296                 va_list ap;
 297                 int i;
 298
 299                 types = calloc((size_t)n_cols, sizeof(*types));
 300                 if (! types)
 301                         return -1;
 302
 303                 va_start(ap, n_cols);
 304
 305                 for (i = 0; i < n_cols; ++i) {
 306                         types[i] = va_arg(ap, int);
 307
 308                         if ((types[i] < 1) || (types[i] > SDB_TYPE_BINARY)) {
 309                                 sdb_log(SDB_LOG_ERR, "unixsock: Unknown column "
 310                                                 "type %i while processing response from the "
 311                                                 "UNIX socket @ %s.", types[i], client->path);
 312                                 va_end(ap);
 313                                 free(types);
 314                                 return -1;
 315                         }
 316                 }
 317
 318                 va_end(ap);
 319         }
 320
 321         while (42) {
 322                 char  buffer[1024];
 323                 char *line;
 324
 325                 int column_count;
 326
 327                 if (! max_lines)
 328                         break;
 329
 330                 if (max_lines > 0)
 331                         --max_lines;
 332
 333                 sdb_unixsock_client_clearerr(client);
 334                 line = sdb_unixsock_client_recv(client, buffer, sizeof(buffer));
 335
 336                 if (! line)
 337                         break;
 338
 339                 column_count = sdb_unixsock_get_column_count(line, delim);
 340
 341                 if ((n_cols >= 0) && (n_cols != column_count)) {
 342                         sdb_log(SDB_LOG_ERR, "unixsock: number of columns (%i) "
 343                                         "does not match the number of requested columns (%i) "
 344                                         "while processing response from the UNIX socket @ %s: %s",
 345                                         column_count, n_cols, client->path, line);
 346                         continue;
 347                 }
 348
 349                 if (column_count <= 0) /* no data */
 350                         continue;
 351
 352                 if (! sdb_unixsock_client_process_one_line(client, line, callback,
 353                                         user_data, delim, column_count, types))
 354                         ++success;
 355         }
 356
 357         free(types);
 358
 359         if ((max_lines > 0)
 360                         || ((max_lines < 0) && (! sdb_unixsock_client_eof(client)))
 361                         || sdb_unixsock_client_error(client)) {
 362                 char errbuf[1024];
 363                 sdb_log(SDB_LOG_ERR, "unixsock: Unexpected end of data while "
 364                                 "reading from socket (%s): %s", client->path,
 365                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 366                 return -1;
 367         }
 368         if (! success)
 369                 return -1;
 370         return 0;
 371 } /* sdb_unixsock_client_process_lines */
 372
 373 int
 374 sdb_unixsock_client_shutdown(sdb_unixsock_client_t *client, int how)
 375 {
 376         int status;
 377
 378         if (! client) {
 379                 errno = ENOTSOCK;
 380                 return -1;
 381         }
 382
 383         fflush(client->fh);
 384         status = shutdown(fileno(client->fh), how);
 385
 386         if (! status) {
 387                 if (how == SHUT_RDWR)
 388                         client->shutdown |= SDB_SHUT_RDWR;
 389                 else
 390                         client->shutdown |= 1 << how;
 391         }
 392         return status;
 393 } /* sdb_unixsock_client_shutdown */
 394
 395 void
 396 sdb_unixsock_client_clearerr(sdb_unixsock_client_t *client)
 397 {
 398         if ((! client) || (! client->fh))
 399                 return;
 400         clearerr(client->fh);
 401 } /* sdb_unixsock_client_clearerr */
 402
 403 int
 404 sdb_unixsock_client_eof(sdb_unixsock_client_t *client)
 405 {
 406         if ((! client) || (! client->fh)) {
 407                 errno = EBADF;
 408                 return -1;
 409         }
 410         return feof(client->fh);
 411 } /* sdb_unixsock_client_eof */
 412
 413 int
 414 sdb_unixsock_client_error(sdb_unixsock_client_t *client)
 415 {
 416         if ((! client) || (! client->fh)) {
 417                 errno = EBADF;
 418                 return -1;
 419         }
 420         return ferror(client->fh);
 421 } /* sdb_unixsock_client_error */
 422
 423 void
 424 sdb_unixsock_client_destroy(sdb_unixsock_client_t *client)
 425 {
 426         if (! client)
 427                 return;
 428
 429         if (client->path)
 430                 free(client->path);
 431         client->path = NULL;
 432
 433         if (client->fh)
 434                 fclose(client->fh);
 435         client->fh = NULL;
 436
 437         free(client);
 438 } /* sdb_unixsock_client_destroy */
 439
 440 const char *
 441 sdb_unixsock_client_path(sdb_unixsock_client_t *client)
 442 {
 443         if (! client)
 444                 return NULL;
 445         return client->path;
 446 } /* sdb_unixsock_client_path */
 447
 448 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 449