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 <fcntl.h>
  29 #include <unistd.h>
  30 #include <errno.h>
  31
  32 #ifdef HAVE_SYS_UN_H
  33 #include <sys/un.h>
  34 #endif
  35
  36 #include <pulse/xmalloc.h>
  37
  38 #include <pulsecore/core-error.h>
  39 #include <pulsecore/core-util.h>
  40 #include <pulsecore/socket.h>
  41 #include <pulsecore/socket-util.h>
  42 #include <pulsecore/log.h>
  43 #include <pulsecore/macro.h>
  44
  45 #include "iochannel.h"
  46
  47 struct pa_iochannel {
  48     int ifd, ofd;
  49     int ifd_type, ofd_type;
  50     pa_mainloop_api* mainloop;
  51
  52     pa_iochannel_cb_t callback;
  53     void*userdata;
  54
  55     pa_bool_t readable:1;
  56     pa_bool_t writable:1;
  57     pa_bool_t hungup:1;
  58     pa_bool_t no_close:1;
  59
  60     pa_io_event* input_event, *output_event;
  61 };
  62
  63 static void callback(pa_mainloop_api* m, pa_io_event *e, int fd, pa_io_event_flags_t f, void *userdata);
  64
  65 static void delete_events(pa_iochannel *io) {
  66     pa_assert(io);
  67
  68     if (io->input_event)
  69         io->mainloop->io_free(io->input_event);
  70
  71     if (io->output_event && io->output_event != io->input_event)
  72         io->mainloop->io_free(io->output_event);
  73
  74     io->input_event = io->output_event = NULL;
  75 }
  76
  77 static void enable_events(pa_iochannel *io) {
  78     pa_assert(io);
  79
  80     if (io->hungup) {
  81         delete_events(io);
  82         return;
  83     }
  84
  85     if (io->ifd == io->ofd && io->ifd >= 0) {
  86         pa_io_event_flags_t f = PA_IO_EVENT_NULL;
  87
  88         if (!io->readable)
  89             f |= PA_IO_EVENT_INPUT;
  90         if (!io->writable)
  91             f |= PA_IO_EVENT_OUTPUT;
  92
  93         pa_assert(io->input_event == io->output_event);
  94
  95         if (f != PA_IO_EVENT_NULL) {
  96             if (io->input_event)
  97                 io->mainloop->io_enable(io->input_event, f);
  98             else
  99                 io->input_event = io->output_event = io->mainloop->io_new(io->mainloop, io->ifd, f, callback, io);
 100         } else
 101             delete_events(io);
 102
 103     } else {
 104
 105         if (io->ifd >= 0) {
 106             if (!io->readable) {
 107                 if (io->input_event)
 108                     io->mainloop->io_enable(io->input_event, PA_IO_EVENT_INPUT);
 109                 else
 110                     io->input_event = io->mainloop->io_new(io->mainloop, io->ifd, PA_IO_EVENT_INPUT, callback, io);
 111             } else if (io->input_event) {
 112                 io->mainloop->io_free(io->input_event);
 113                 io->input_event = NULL;
 114             }
 115         }
 116
 117         if (io->ofd >= 0) {
 118             if (!io->writable) {
 119                 if (io->output_event)
 120                     io->mainloop->io_enable(io->output_event, PA_IO_EVENT_OUTPUT);
 121                 else
 122                     io->output_event = io->mainloop->io_new(io->mainloop, io->ofd, PA_IO_EVENT_OUTPUT, callback, io);
 123             } else if (io->input_event) {
 124                 io->mainloop->io_free(io->output_event);
 125                 io->output_event = NULL;
 126             }
 127         }
 128     }
 129 }
 130
 131 static void callback(pa_mainloop_api* m, pa_io_event *e, int fd, pa_io_event_flags_t f, void *userdata) {
 132     pa_iochannel *io = userdata;
 133     pa_bool_t changed = FALSE;
 134
 135     pa_assert(m);
 136     pa_assert(e);
 137     pa_assert(fd >= 0);
 138     pa_assert(userdata);
 139
 140     if ((f & (PA_IO_EVENT_HANGUP|PA_IO_EVENT_ERROR)) && !io->hungup) {
 141         io->hungup = TRUE;
 142         changed = TRUE;
 143     }
 144
 145     if ((f & PA_IO_EVENT_INPUT) && !io->readable) {
 146         io->readable = TRUE;
 147         changed = TRUE;
 148         pa_assert(e == io->input_event);
 149     }
 150
 151     if ((f & PA_IO_EVENT_OUTPUT) && !io->writable) {
 152         io->writable = TRUE;
 153         changed = TRUE;
 154         pa_assert(e == io->output_event);
 155     }
 156
 157     if (changed) {
 158         enable_events(io);
 159
 160         if (io->callback)
 161             io->callback(io, io->userdata);
 162     }
 163 }
 164
 165 pa_iochannel* pa_iochannel_new(pa_mainloop_api*m, int ifd, int ofd) {
 166     pa_iochannel *io;
 167
 168     pa_assert(m);
 169     pa_assert(ifd >= 0 || ofd >= 0);
 170
 171     io = pa_xnew0(pa_iochannel, 1);
 172     io->ifd = ifd;
 173     io->ofd = ofd;
 174     io->mainloop = m;
 175
 176     if (io->ifd >= 0)
 177         pa_make_fd_nonblock(io->ifd);
 178
 179     if (io->ofd >= 0 && io->ofd != io->ifd)
 180         pa_make_fd_nonblock(io->ofd);
 181
 182     enable_events(io);
 183     return io;
 184 }
 185
 186 void pa_iochannel_free(pa_iochannel*io) {
 187     pa_assert(io);
 188
 189     delete_events(io);
 190
 191     if (!io->no_close) {
 192         if (io->ifd >= 0)
 193             pa_close(io->ifd);
 194         if (io->ofd >= 0 && io->ofd != io->ifd)
 195             pa_close(io->ofd);
 196     }
 197
 198     pa_xfree(io);
 199 }
 200
 201 pa_bool_t pa_iochannel_is_readable(pa_iochannel*io) {
 202     pa_assert(io);
 203
 204     return io->readable || io->hungup;
 205 }
 206
 207 pa_bool_t pa_iochannel_is_writable(pa_iochannel*io) {
 208     pa_assert(io);
 209
 210     return io->writable && !io->hungup;
 211 }
 212
 213 pa_bool_t pa_iochannel_is_hungup(pa_iochannel*io) {
 214     pa_assert(io);
 215
 216     return io->hungup;
 217 }
 218
 219 ssize_t pa_iochannel_write(pa_iochannel*io, const void*data, size_t l) {
 220     ssize_t r;
 221
 222     pa_assert(io);
 223     pa_assert(data);
 224     pa_assert(l);
 225     pa_assert(io->ofd >= 0);
 226
 227     if ((r = pa_write(io->ofd, data, l, &io->ofd_type)) >= 0) {
 228         io->writable = io->hungup = FALSE;
 229         enable_events(io);
 230     }
 231
 232     return r;
 233 }
 234
 235 ssize_t pa_iochannel_read(pa_iochannel*io, void*data, size_t l) {
 236     ssize_t r;
 237
 238     pa_assert(io);
 239     pa_assert(data);
 240     pa_assert(io->ifd >= 0);
 241
 242     if ((r = pa_read(io->ifd, data, l, &io->ifd_type)) >= 0) {
 243
 244         /* We also reset the hangup flag here to ensure that another
 245          * IO callback is triggered so that we will again call into
 246          * user code */
 247         io->readable = io->hungup = FALSE;
 248         enable_events(io);
 249     }
 250
 251     return r;
 252 }
 253
 254 #ifdef HAVE_CREDS
 255
 256 pa_bool_t pa_iochannel_creds_supported(pa_iochannel *io) {
 257     struct {
 258         struct sockaddr sa;
 259         struct sockaddr_un un;
 260         struct sockaddr_storage storage;
 261     } sa;
 262
 263     socklen_t l;
 264
 265     pa_assert(io);
 266     pa_assert(io->ifd >= 0);
 267     pa_assert(io->ofd == io->ifd);
 268
 269     l = sizeof(sa);
 270     if (getsockname(io->ifd, &sa.sa, &l) < 0)
 271         return FALSE;
 272
 273     return sa.sa.sa_family == AF_UNIX;
 274 }
 275
 276 int pa_iochannel_creds_enable(pa_iochannel *io) {
 277     int t = 1;
 278
 279     pa_assert(io);
 280     pa_assert(io->ifd >= 0);
 281
 282     if (setsockopt(io->ifd, SOL_SOCKET, SO_PASSCRED, &t, sizeof(t)) < 0) {
 283         pa_log_error("setsockopt(SOL_SOCKET, SO_PASSCRED): %s", pa_cstrerror(errno));
 284         return -1;
 285     }
 286
 287     return 0;
 288 }
 289
 290 ssize_t pa_iochannel_write_with_creds(pa_iochannel*io, const void*data, size_t l, const pa_creds *ucred) {
 291     ssize_t r;
 292     struct msghdr mh;
 293     struct iovec iov;
 294     union {
 295         struct cmsghdr hdr;
 296         uint8_t data[CMSG_SPACE(sizeof(struct ucred))];
 297     } cmsg;
 298     struct ucred *u;
 299
 300     pa_assert(io);
 301     pa_assert(data);
 302     pa_assert(l);
 303     pa_assert(io->ofd >= 0);
 304
 305     pa_zero(iov);
 306     iov.iov_base = (void*) data;
 307     iov.iov_len = l;
 308
 309     pa_zero(cmsg);
 310     cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));
 311     cmsg.hdr.cmsg_level = SOL_SOCKET;
 312     cmsg.hdr.cmsg_type = SCM_CREDENTIALS;
 313
 314     u = (struct ucred*) CMSG_DATA(&cmsg.hdr);
 315
 316     u->pid = getpid();
 317     if (ucred) {
 318         u->uid = ucred->uid;
 319         u->gid = ucred->gid;
 320     } else {
 321         u->uid = getuid();
 322         u->gid = getgid();
 323     }
 324
 325     pa_zero(mh);
 326     mh.msg_iov = &iov;
 327     mh.msg_iovlen = 1;
 328     mh.msg_control = &cmsg;
 329     mh.msg_controllen = sizeof(cmsg);
 330
 331     if ((r = sendmsg(io->ofd, &mh, MSG_NOSIGNAL)) >= 0) {
 332         io->writable = io->hungup = FALSE;
 333         enable_events(io);
 334     }
 335
 336     return r;
 337 }
 338
 339 ssize_t pa_iochannel_read_with_creds(pa_iochannel*io, void*data, size_t l, pa_creds *creds, pa_bool_t *creds_valid) {
 340     ssize_t r;
 341     struct msghdr mh;
 342     struct iovec iov;
 343     union {
 344         struct cmsghdr hdr;
 345         uint8_t data[CMSG_SPACE(sizeof(struct ucred))];
 346     } cmsg;
 347
 348     pa_assert(io);
 349     pa_assert(data);
 350     pa_assert(l);
 351     pa_assert(io->ifd >= 0);
 352     pa_assert(creds);
 353     pa_assert(creds_valid);
 354
 355     pa_zero(iov);
 356     iov.iov_base = data;
 357     iov.iov_len = l;
 358
 359     pa_zero(cmsg);
 360     pa_zero(mh);
 361     mh.msg_iov = &iov;
 362     mh.msg_iovlen = 1;
 363     mh.msg_control = &cmsg;
 364     mh.msg_controllen = sizeof(cmsg);
 365
 366     if ((r = recvmsg(io->ifd, &mh, 0)) >= 0) {
 367         struct cmsghdr *cmh;
 368
 369         *creds_valid = FALSE;
 370
 371         for (cmh = CMSG_FIRSTHDR(&mh); cmh; cmh = CMSG_NXTHDR(&mh, cmh)) {
 372
 373             if (cmh->cmsg_level == SOL_SOCKET && cmh->cmsg_type == SCM_CREDENTIALS) {
 374                 struct ucred u;
 375                 pa_assert(cmh->cmsg_len == CMSG_LEN(sizeof(struct ucred)));
 376                 memcpy(&u, CMSG_DATA(cmh), sizeof(struct ucred));
 377
 378                 creds->gid = u.gid;
 379                 creds->uid = u.uid;
 380                 *creds_valid = TRUE;
 381                 break;
 382             }
 383         }
 384
 385         io->readable = io->hungup = FALSE;
 386         enable_events(io);
 387     }
 388
 389     return r;
 390 }
 391
 392 #endif /* HAVE_CREDS */
 393
 394 void pa_iochannel_set_callback(pa_iochannel*io, pa_iochannel_cb_t _callback, void *userdata) {
 395     pa_assert(io);
 396
 397     io->callback = _callback;
 398     io->userdata = userdata;
 399 }
 400
 401 void pa_iochannel_set_noclose(pa_iochannel*io, pa_bool_t b) {
 402     pa_assert(io);
 403
 404     io->no_close = !!b;
 405 }
 406
 407 void pa_iochannel_socket_peer_to_string(pa_iochannel*io, char*s, size_t l) {
 408     pa_assert(io);
 409     pa_assert(s);
 410     pa_assert(l);
 411
 412     pa_socket_peer_to_string(io->ifd, s, l);
 413 }
 414
 415 int pa_iochannel_socket_set_rcvbuf(pa_iochannel *io, size_t l) {
 416     pa_assert(io);
 417
 418     return pa_socket_set_rcvbuf(io->ifd, l);
 419 }
 420
 421 int pa_iochannel_socket_set_sndbuf(pa_iochannel *io, size_t l) {
 422     pa_assert(io);
 423
 424     return pa_socket_set_sndbuf(io->ofd, l);
 425 }
 426
 427 pa_mainloop_api* pa_iochannel_get_mainloop_api(pa_iochannel *io) {
 428     pa_assert(io);
 429
 430     return io->mainloop;
 431 }
 432
 433 int pa_iochannel_get_recv_fd(pa_iochannel *io) {
 434     pa_assert(io);
 435
 436     return io->ifd;
 437 }
 438
 439 int pa_iochannel_get_send_fd(pa_iochannel *io) {
 440     pa_assert(io);
 441
 442     return io->ofd;
 443 }
 444
 445 pa_bool_t pa_iochannel_socket_is_local(pa_iochannel *io) {
 446     pa_assert(io);
 447
 448     if (pa_socket_is_local(io->ifd))
 449         return TRUE;
 450
 451     if (io->ifd != io->ofd)
 452         if (pa_socket_is_local(io->ofd))
 453             return TRUE;
 454
 455     return FALSE;
 456 }