src/client/sock.c

   1 /*
   2  * SysDB - src/client/sock.c
   3  * Copyright (C) 2013 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 "client/sock.h"
  33 #include "utils/error.h"
  34 #include "utils/strbuf.h"
  35 #include "utils/proto.h"
  36 #include "utils/os.h"
  37
  38 #include <arpa/inet.h>
  39
  40 #include <assert.h>
  41 #include <errno.h>
  42 #include <limits.h>
  43
  44 #include <stdlib.h>
  45
  46 #include <string.h>
  47 #include <strings.h>
  48
  49 #include <unistd.h>
  50
  51 #include <sys/socket.h>
  52 #include <sys/un.h>
  53
  54 /*
  55  * private data types
  56  */
  57
  58 struct sdb_client {
  59         char *address;
  60         int   fd;
  61         bool  eof;
  62
  63         ssize_t (*read)(sdb_client_t *, sdb_strbuf_t *, size_t);
  64         ssize_t (*write)(sdb_client_t *, const void *, size_t);
  65 };
  66
  67 /*
  68  * private helper functions
  69  */
  70
  71 static ssize_t
  72 client_read(sdb_client_t *client, sdb_strbuf_t *buf, size_t n)
  73 {
  74         return sdb_strbuf_read(buf, client->fd, n);
  75 } /* client_read */
  76
  77 static ssize_t
  78 client_write(sdb_client_t *client, const void *buf, size_t n)
  79 {
  80         return sdb_write(client->fd, n, buf);
  81 } /* client_write */
  82
  83 static int
  84 connect_unixsock(sdb_client_t *client, const char *address)
  85 {
  86         struct sockaddr_un sa;
  87
  88         client->fd = socket(AF_UNIX, SOCK_STREAM, /* protocol = */ 0);
  89         if (client->fd < 0) {
  90                 char errbuf[1024];
  91                 sdb_log(SDB_LOG_ERR, "Failed to open socket: %s",
  92                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
  93                 return -1;
  94         }
  95
  96         sa.sun_family = AF_UNIX;
  97         strncpy(sa.sun_path, address, sizeof(sa.sun_path));
  98         sa.sun_path[sizeof(sa.sun_path) - 1] = '\0';
  99
 100         if (connect(client->fd, (struct sockaddr *)&sa, sizeof(sa))) {
 101                 char errbuf[1024];
 102                 sdb_client_close(client);
 103                 sdb_log(SDB_LOG_ERR, "Failed to connect to '%s': %s",
 104                                 sa.sun_path, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 105                 return -1;
 106         }
 107         return client->fd;
 108 } /* connect_unixsock */
 109
 110 /*
 111  * public API
 112  */
 113
 114 sdb_client_t *
 115 sdb_client_create(const char *address)
 116 {
 117         sdb_client_t *client;
 118
 119         if (! address)
 120                 return NULL;
 121
 122         client = malloc(sizeof(*client));
 123         if (! client) {
 124                 sdb_log(SDB_LOG_ERR, "Out of memory");
 125                 return NULL;
 126         }
 127         memset(client, 0, sizeof(*client));
 128         client->fd = -1;
 129         client->eof = 1;
 130
 131         client->read = client_read;
 132         client->write = client_write;
 133
 134         client->address = strdup(address);
 135         if (! client->address) {
 136                 sdb_client_destroy(client);
 137                 sdb_log(SDB_LOG_ERR, "Out of memory");
 138                 return NULL;
 139         }
 140
 141         return client;
 142 } /* sdb_client_create */
 143
 144 void
 145 sdb_client_destroy(sdb_client_t *client)
 146 {
 147         if (! client)
 148                 return;
 149
 150         sdb_client_close(client);
 151
 152         if (client->address)
 153                 free(client->address);
 154         client->address = NULL;
 155
 156         free(client);
 157 } /* sdb_client_destroy */
 158
 159 int
 160 sdb_client_connect(sdb_client_t *client, const char *username)
 161 {
 162         sdb_strbuf_t *buf;
 163         ssize_t status;
 164         uint32_t rstatus;
 165
 166         if ((! client) || (! client->address))
 167                 return -1;
 168
 169         if (client->fd >= 0)
 170                 return -1;
 171
 172         if (!strncasecmp(client->address, "unix:", strlen("unix:")))
 173                 connect_unixsock(client, client->address + strlen("unix:"));
 174         else if (*client->address == '/')
 175                 connect_unixsock(client, client->address);
 176         else {
 177                 sdb_log(SDB_LOG_ERR, "Unknown address type: %s", client->address);
 178                 return -1;
 179         }
 180
 181         if (client->fd < 0)
 182                 return -1;
 183         client->eof = 0;
 184
 185         /* XXX */
 186         if (! username)
 187                 username = "";
 188
 189         status = sdb_client_send(client, SDB_CONNECTION_STARTUP,
 190                         (uint32_t)strlen(username), username);
 191         if (status < 0) {
 192                 char errbuf[1024];
 193                 sdb_client_close(client);
 194                 sdb_log(SDB_LOG_ERR, "Failed to send STARTUP message to server: %s",
 195                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 196                 return (int)status;
 197         }
 198
 199         buf = sdb_strbuf_create(64);
 200         rstatus = 0;
 201         status = sdb_client_recv(client, &rstatus, buf);
 202         if ((status > 0) && (rstatus == SDB_CONNECTION_OK)) {
 203                 sdb_strbuf_destroy(buf);
 204                 return 0;
 205         }
 206
 207         if (status < 0) {
 208                 char errbuf[1024];
 209                 sdb_log(SDB_LOG_ERR, "Failed to receive server response: %s",
 210                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 211         }
 212         else if (client->eof)
 213                 sdb_log(SDB_LOG_ERR, "Encountered end-of-file while waiting "
 214                                 "for server response");
 215
 216         if (rstatus == SDB_CONNECTION_ERROR) {
 217                 sdb_log(SDB_LOG_ERR, "Access denied for user '%s': %s",
 218                                 username, sdb_strbuf_string(buf));
 219                 status = -((int)rstatus);
 220         }
 221         else if (rstatus != SDB_CONNECTION_OK) {
 222                 sdb_log(SDB_LOG_ERR, "Received unsupported authentication request "
 223                                 "(status %d) during startup", (int)rstatus);
 224                 status = -((int)rstatus);
 225         }
 226
 227         sdb_client_close(client);
 228         sdb_strbuf_destroy(buf);
 229         return (int)status;
 230 } /* sdb_client_connect */
 231
 232 int
 233 sdb_client_sockfd(sdb_client_t *client)
 234 {
 235         if (! client)
 236                 return -1;
 237         return client->fd;
 238 } /* sdb_client_sockfd */
 239
 240 int
 241 sdb_client_shutdown(sdb_client_t *client, int how)
 242 {
 243         if (! client) {
 244                 errno = ENOTSOCK;
 245                 return -1;
 246         }
 247
 248         if (client->fd < 0) {
 249                 errno = EBADF;
 250                 return -1;
 251         }
 252
 253         return shutdown(client->fd, how);
 254 } /* sdb_client_shutdown */
 255
 256 void
 257 sdb_client_close(sdb_client_t *client)
 258 {
 259         if (! client)
 260                 return;
 261
 262         close(client->fd);
 263         client->fd = -1;
 264         client->eof = 1;
 265 } /* sdb_client_close */
 266
 267 ssize_t
 268 sdb_client_send(sdb_client_t *client,
 269                 uint32_t cmd, uint32_t msg_len, const char *msg)
 270 {
 271         char buf[2 * sizeof(uint32_t) + msg_len];
 272
 273         if ((! client) || (! client->fd))
 274                 return -1;
 275         if (sdb_proto_marshal(buf, sizeof(buf), cmd, msg_len, msg) < 0)
 276                 return -1;
 277
 278         return client->write(client, buf, sizeof(buf));
 279 } /* sdb_client_send */
 280
 281 ssize_t
 282 sdb_client_recv(sdb_client_t *client,
 283                 uint32_t *code, sdb_strbuf_t *buf)
 284 {
 285         uint32_t rstatus = UINT32_MAX;
 286         uint32_t rlen = UINT32_MAX;
 287
 288         size_t total = 0;
 289         size_t req = 2 * sizeof(uint32_t);
 290
 291         size_t data_offset = sdb_strbuf_len(buf);
 292
 293         if (code)
 294                 *code = UINT32_MAX;
 295
 296         if ((! client) || (! client->fd) || (! buf)) {
 297                 errno = EBADF;
 298                 return -1;
 299         }
 300
 301         while (42) {
 302                 ssize_t status;
 303
 304                 if (sdb_select(client->fd, SDB_SELECTIN))
 305                         return -1;
 306
 307                 errno = 0;
 308                 status = client->read(client, buf, req);
 309                 if (status < 0) {
 310                         if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
 311                                 continue;
 312                         return status;
 313                 }
 314                 else if (! status) {
 315                         client->eof = 1;
 316                         break;
 317                 }
 318
 319                 total += (size_t)status;
 320
 321                 if (total != req)
 322                         continue;
 323
 324                 if (rstatus == UINT32_MAX) {
 325                         const char *str = sdb_strbuf_string(buf) + data_offset;
 326                         size_t len = sdb_strbuf_len(buf) - data_offset;
 327                         ssize_t n;
 328
 329                         /* retrieve status and data len */
 330                         assert(len >= 2 * sizeof(uint32_t));
 331                         n = sdb_proto_unmarshal_int32(str, len, &rstatus);
 332                         str += n; len -= (size_t)n;
 333                         sdb_proto_unmarshal_int32(str, len, &rlen);
 334
 335                         if (! rlen)
 336                                 break;
 337
 338                         req = (size_t)rlen;
 339                         total = 0;
 340                 }
 341                 else /* finished reading data */
 342                         break;
 343         }
 344
 345         if (total != req) {
 346                 /* unexpected EOF; clear partially read data */
 347                 sdb_strbuf_skip(buf, data_offset, sdb_strbuf_len(buf));
 348                 return 0;
 349         }
 350
 351         if (rstatus != UINT32_MAX)
 352                 /* remove status,len */
 353                 sdb_strbuf_skip(buf, data_offset, 2 * sizeof(rstatus));
 354
 355         if (code)
 356                 *code = rstatus;
 357
 358         return (ssize_t)total;
 359 } /* sdb_client_recv */
 360
 361 bool
 362 sdb_client_eof(sdb_client_t *client)
 363 {
 364         if ((! client) || (client->fd < 0))
 365                 return 1;
 366         return client->eof;
 367 } /* sdb_client_eof */
 368
 369 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 370