src/pulsecore/iochannel.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5   Copyright 2006-2007 Pierre Ossman <ossman@cendio.se> for Cendio AB
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as
   9   published by the Free Software Foundation; either version 2.1 of the
  10   License, or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public
  18   License along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30
  31 #ifdef HAVE_SYS_UN_H
  32 #include <sys/un.h>
  33 #endif
  34
  35 #include <pulse/xmalloc.h>
  36
  37 #include <pulsecore/core-error.h>
  38 #include <pulsecore/core-util.h>
  39 #include <pulsecore/socket.h>
  40 #include <pulsecore/socket-util.h>
  41 #include <pulsecore/log.h>
  42 #include <pulsecore/macro.h>
  43
  44 #include "iochannel.h"
  45
  46 struct pa_iochannel {
  47     int ifd, ofd;
  48     int ifd_type, ofd_type;
  49     pa_mainloop_api* mainloop;
  50
  51     pa_iochannel_cb_t callback;
  52     void*userdata;
  53
  54     pa_bool_t readable:1;
  55     pa_bool_t writable:1;
  56     pa_bool_t hungup:1;
  57     pa_bool_t no_close:1;
  58
  59     pa_io_event* input_event, *output_event;
  60 };
  61
  62 static void callback(pa_mainloop_api* m, pa_io_event *e, int fd, pa_io_event_flags_t f, void *userdata);
  63
  64 static void delete_events(pa_iochannel *io) {
  65     pa_assert(io);
  66
  67     if (io->input_event)
  68         io->mainloop->io_free(io->input_event);
  69
  70     if (io->output_event && io->output_event != io->input_event)
  71         io->mainloop->io_free(io->output_event);
  72
  73     io->input_event = io->output_event = NULL;
  74 }
  75
  76 static void enable_events(pa_iochannel *io) {
  77     pa_assert(io);
  78
  79     if (io->hungup) {
  80         delete_events(io);
  81         return;
  82     }
  83
  84     if (io->ifd == io->ofd && io->ifd >= 0) {
  85         pa_io_event_flags_t f = PA_IO_EVENT_NULL;
  86
  87         if (!io->readable)
  88             f |= PA_IO_EVENT_INPUT;
  89         if (!io->writable)
  90             f |= PA_IO_EVENT_OUTPUT;
  91
  92         pa_assert(io->input_event == io->output_event);
  93
  94         if (f != PA_IO_EVENT_NULL) {
  95             if (io->input_event)
  96                 io->mainloop->io_enable(io->input_event, f);
  97             else
  98                 io->input_event = io->output_event = io->mainloop->io_new(io->mainloop, io->ifd, f, callback, io);
  99         } else
 100             delete_events(io);
 101
 102     } else {
 103
 104         if (io->ifd >= 0) {
 105             if (!io->readable) {
 106                 if (io->input_event)
 107                     io->mainloop->io_enable(io->input_event, PA_IO_EVENT_INPUT);
 108                 else
 109                     io->input_event = io->mainloop->io_new(io->mainloop, io->ifd, PA_IO_EVENT_INPUT, callback, io);
 110             } else if (io->input_event) {
 111                 io->mainloop->io_free(io->input_event);
 112                 io->input_event = NULL;
 113             }
 114         }
 115
 116         if (io->ofd >= 0) {
 117             if (!io->writable) {
 118                 if (io->output_event)
 119                     io->mainloop->io_enable(io->output_event, PA_IO_EVENT_OUTPUT);
 120                 else
 121                     io->output_event = io->mainloop->io_new(io->mainloop, io->ofd, PA_IO_EVENT_OUTPUT, callback, io);
 122             } else if (io->input_event) {
 123                 io->mainloop->io_free(io->output_event);
 124                 io->output_event = NULL;
 125             }
 126         }
 127     }
 128 }
 129
 130 static void callback(pa_mainloop_api* m, pa_io_event *e, int fd, pa_io_event_flags_t f, void *userdata) {
 131     pa_iochannel *io = userdata;
 132     pa_bool_t changed = FALSE;
 133
 134     pa_assert(m);
 135     pa_assert(e);
 136     pa_assert(fd >= 0);
 137     pa_assert(userdata);
 138
 139     if ((f & (PA_IO_EVENT_HANGUP|PA_IO_EVENT_ERROR)) && !io->hungup) {
 140         io->hungup = TRUE;
 141         changed = TRUE;
 142     }
 143
 144     if ((f & PA_IO_EVENT_INPUT) && !io->readable) {
 145         io->readable = TRUE;
 146         changed = TRUE;
 147         pa_assert(e == io->input_event);
 148     }
 149
 150     if ((f & PA_IO_EVENT_OUTPUT) && !io->writable) {
 151         io->writable = TRUE;
 152         changed = TRUE;
 153         pa_assert(e == io->output_event);
 154     }
 155
 156     if (changed) {
 157         enable_events(io);
 158
 159         if (io->callback)
 160             io->callback(io, io->userdata);
 161     }
 162 }
 163
 164 pa_iochannel* pa_iochannel_new(pa_mainloop_api*m, int ifd, int ofd) {
 165     pa_iochannel *io;
 166
 167     pa_assert(m);
 168     pa_assert(ifd >= 0 || ofd >= 0);
 169
 170     io = pa_xnew0(pa_iochannel, 1);
 171     io->ifd = ifd;
 172     io->ofd = ofd;
 173     io->mainloop = m;
 174
 175     if (io->ifd >= 0)
 176         pa_make_fd_nonblock(io->ifd);
 177
 178     if (io->ofd >= 0 && io->ofd != io->ifd)
 179         pa_make_fd_nonblock(io->ofd);
 180
 181     enable_events(io);
 182     return io;
 183 }
 184
 185 void pa_iochannel_free(pa_iochannel*io) {
 186     pa_assert(io);
 187
 188     delete_events(io);
 189
 190     if (!io->no_close) {
 191         if (io->ifd >= 0)
 192             pa_close(io->ifd);
 193         if (io->ofd >= 0 && io->ofd != io->ifd)
 194             pa_close(io->ofd);
 195     }
 196
 197     pa_xfree(io);
 198 }
 199
 200 pa_bool_t pa_iochannel_is_readable(pa_iochannel*io) {
 201     pa_assert(io);
 202
 203     return io->readable || io->hungup;
 204 }
 205
 206 pa_bool_t pa_iochannel_is_writable(pa_iochannel*io) {
 207     pa_assert(io);
 208
 209     return io->writable && !io->hungup;
 210 }
 211
 212 pa_bool_t pa_iochannel_is_hungup(pa_iochannel*io) {
 213     pa_assert(io);
 214
 215     return io->hungup;
 216 }
 217
 218 ssize_t pa_iochannel_write(pa_iochannel*io, const void*data, size_t l) {
 219     ssize_t r;
 220
 221     pa_assert(io);
 222     pa_assert(data);
 223     pa_assert(l);
 224     pa_assert(io->ofd >= 0);
 225
 226     if ((r = pa_write(io->ofd, data, l, &io->ofd_type)) >= 0) {
 227         io->writable = io->hungup = FALSE;
 228         enable_events(io);
 229     }
 230
 231     return r;
 232 }
 233
 234 ssize_t pa_iochannel_read(pa_iochannel*io, void*data, size_t l) {
 235     ssize_t r;
 236
 237     pa_assert(io);
 238     pa_assert(data);
 239     pa_assert(io->ifd >= 0);
 240
 241     if ((r = pa_read(io->ifd, data, l, &io->ifd_type)) >= 0) {
 242
 243         /* We also reset the hangup flag here to ensure that another
 244          * IO callback is triggered so that we will again call into
 245          * user code */
 246         io->readable = io->hungup = FALSE;
 247         enable_events(io);
 248     }
 249
 250     return r;
 251 }
 252
 253 #ifdef HAVE_CREDS
 254
 255 pa_bool_t pa_iochannel_creds_supported(pa_iochannel *io) {
 256     struct {
 257         struct sockaddr sa;
 258         struct sockaddr_un un;
 259         struct sockaddr_storage storage;
 260     } sa;
 261
 262     socklen_t l;
 263
 264     pa_assert(io);
 265     pa_assert(io->ifd >= 0);
 266     pa_assert(io->ofd == io->ifd);
 267
 268     l = sizeof(sa);
 269     if (getsockname(io->ifd, &sa.sa, &l) < 0)
 270         return FALSE;
 271
 272     return sa.sa.sa_family == AF_UNIX;
 273 }
 274
 275 int pa_iochannel_creds_enable(pa_iochannel *io) {
 276     int t = 1;
 277
 278     pa_assert(io);
 279     pa_assert(io->ifd >= 0);
 280
 281     if (setsockopt(io->ifd, SOL_SOCKET, SO_PASSCRED, &t, sizeof(t)) < 0) {
 282         pa_log_error("setsockopt(SOL_SOCKET, SO_PASSCRED): %s", pa_cstrerror(errno));
 283         return -1;
 284     }
 285
 286     return 0;
 287 }
 288
 289 ssize_t pa_iochannel_write_with_creds(pa_iochannel*io, const void*data, size_t l, const pa_creds *ucred) {
 290     ssize_t r;
 291     struct msghdr mh;
 292     struct iovec iov;
 293     union {
 294         struct cmsghdr hdr;
 295         uint8_t data[CMSG_SPACE(sizeof(struct ucred))];
 296     } cmsg;
 297     struct ucred *u;
 298
 299     pa_assert(io);
 300     pa_assert(data);
 301     pa_assert(l);
 302     pa_assert(io->ofd >= 0);
 303
 304     pa_zero(iov);
 305     iov.iov_base = (void*) data;
 306     iov.iov_len = l;
 307
 308     pa_zero(cmsg);
 309     cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));
 310     cmsg.hdr.cmsg_level = SOL_SOCKET;
 311     cmsg.hdr.cmsg_type = SCM_CREDENTIALS;
 312
 313     u = (struct ucred*) CMSG_DATA(&cmsg.hdr);
 314
 315     u->pid = getpid();
 316     if (ucred) {
 317         u->uid = ucred->uid;
 318         u->gid = ucred->gid;
 319     } else {
 320         u->uid = getuid();
 321         u->gid = getgid();
 322     }
 323
 324     pa_zero(mh);
 325     mh.msg_iov = &iov;
 326     mh.msg_iovlen = 1;
 327     mh.msg_control = &cmsg;
 328     mh.msg_controllen = sizeof(cmsg);
 329
 330     if ((r = sendmsg(io->ofd, &mh, MSG_NOSIGNAL)) >= 0) {
 331         io->writable = io->hungup = FALSE;
 332         enable_events(io);
 333     }
 334
 335     return r;
 336 }
 337
 338 ssize_t pa_iochannel_read_with_creds(pa_iochannel*io, void*data, size_t l, pa_creds *creds, pa_bool_t *creds_valid) {
 339     ssize_t r;
 340     struct msghdr mh;
 341     struct iovec iov;
 342     union {
 343         struct cmsghdr hdr;
 344         uint8_t data[CMSG_SPACE(sizeof(struct ucred))];
 345     } cmsg;
 346
 347     pa_assert(io);
 348     pa_assert(data);
 349     pa_assert(l);
 350     pa_assert(io->ifd >= 0);
 351     pa_assert(creds);
 352     pa_assert(creds_valid);
 353
 354     pa_zero(iov);
 355     iov.iov_base = data;
 356     iov.iov_len = l;
 357
 358     pa_zero(cmsg);
 359     pa_zero(mh);
 360     mh.msg_iov = &iov;
 361     mh.msg_iovlen = 1;
 362     mh.msg_control = &cmsg;
 363     mh.msg_controllen = sizeof(cmsg);
 364
 365     if ((r = recvmsg(io->ifd, &mh, 0)) >= 0) {
 366         struct cmsghdr *cmh;
 367
 368         *creds_valid = FALSE;
 369
 370         for (cmh = CMSG_FIRSTHDR(&mh); cmh; cmh = CMSG_NXTHDR(&mh, cmh)) {
 371
 372             if (cmh->cmsg_level == SOL_SOCKET && cmh->cmsg_type == SCM_CREDENTIALS) {
 373                 struct ucred u;
 374                 pa_assert(cmh->cmsg_len == CMSG_LEN(sizeof(struct ucred)));
 375                 memcpy(&u, CMSG_DATA(cmh), sizeof(struct ucred));
 376
 377                 creds->gid = u.gid;
 378                 creds->uid = u.uid;
 379                 *creds_valid = TRUE;
 380                 break;
 381             }
 382         }
 383
 384         io->readable = io->hungup = FALSE;
 385         enable_events(io);
 386     }
 387
 388     return r;
 389 }
 390
 391 #endif /* HAVE_CREDS */
 392
 393 void pa_iochannel_set_callback(pa_iochannel*io, pa_iochannel_cb_t _callback, void *userdata) {
 394     pa_assert(io);
 395
 396     io->callback = _callback;
 397     io->userdata = userdata;
 398 }
 399
 400 void pa_iochannel_set_noclose(pa_iochannel*io, pa_bool_t b) {
 401     pa_assert(io);
 402
 403     io->no_close = !!b;
 404 }
 405
 406 void pa_iochannel_socket_peer_to_string(pa_iochannel*io, char*s, size_t l) {
 407     pa_assert(io);
 408     pa_assert(s);
 409     pa_assert(l);
 410
 411     pa_socket_peer_to_string(io->ifd, s, l);
 412 }
 413
 414 int pa_iochannel_socket_set_rcvbuf(pa_iochannel *io, size_t l) {
 415     pa_assert(io);
 416
 417     return pa_socket_set_rcvbuf(io->ifd, l);
 418 }
 419
 420 int pa_iochannel_socket_set_sndbuf(pa_iochannel *io, size_t l) {
 421     pa_assert(io);
 422
 423     return pa_socket_set_sndbuf(io->ofd, l);
 424 }
 425
 426 pa_mainloop_api* pa_iochannel_get_mainloop_api(pa_iochannel *io) {
 427     pa_assert(io);
 428
 429     return io->mainloop;
 430 }
 431
 432 int pa_iochannel_get_recv_fd(pa_iochannel *io) {
 433     pa_assert(io);
 434
 435     return io->ifd;
 436 }
 437
 438 int pa_iochannel_get_send_fd(pa_iochannel *io) {
 439     pa_assert(io);
 440
 441     return io->ofd;
 442 }
 443
 444 pa_bool_t pa_iochannel_socket_is_local(pa_iochannel *io) {
 445     pa_assert(io);
 446
 447     if (pa_socket_is_local(io->ifd))
 448         return TRUE;
 449
 450     if (io->ifd != io->ofd)
 451         if (pa_socket_is_local(io->ofd))
 452             return TRUE;
 453
 454     return FALSE;
 455 }