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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *  * Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  *  * Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in
     12  *    the documentation and/or other materials provided with the
     13  *    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
     17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
     22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #undef _FORTIFY_SOURCE
     30 #include <errno.h>
     31 #include <sys/poll.h>
     32 #include <sys/select.h>
     33 
     34 #include "private/bionic_time_conversions.h"
     35 #include "private/kernel_sigset_t.h"
     36 
     37 extern "C" int __ppoll(pollfd*, unsigned int, timespec*, const kernel_sigset_t*, size_t);
     38 extern "C" int __pselect6(int, fd_set*, fd_set*, fd_set*, timespec*, void*);
     39 
     40 int poll(pollfd* fds, nfds_t fd_count, int ms) {
     41   timespec ts;
     42   timespec* ts_ptr = NULL;
     43   if (ms >= 0) {
     44     timespec_from_ms(ts, ms);
     45     ts_ptr = &ts;
     46   }
     47   return __ppoll(fds, fd_count, ts_ptr, NULL, 0);
     48 }
     49 
     50 int ppoll(pollfd* fds, nfds_t fd_count, const timespec* ts, const sigset_t* ss) {
     51   timespec mutable_ts;
     52   timespec* mutable_ts_ptr = NULL;
     53   if (ts != NULL) {
     54     mutable_ts = *ts;
     55     mutable_ts_ptr = &mutable_ts;
     56   }
     57 
     58   kernel_sigset_t kernel_ss;
     59   kernel_sigset_t* kernel_ss_ptr = NULL;
     60   if (ss != NULL) {
     61     kernel_ss.set(ss);
     62     kernel_ss_ptr = &kernel_ss;
     63   }
     64 
     65   return __ppoll(fds, fd_count, mutable_ts_ptr, kernel_ss_ptr, sizeof(kernel_ss));
     66 }
     67 
     68 int select(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds, timeval* tv) {
     69   timespec ts;
     70   timespec* ts_ptr = NULL;
     71   if (tv != NULL) {
     72     if (!timespec_from_timeval(ts, *tv)) {
     73       errno = EINVAL;
     74       return -1;
     75     }
     76     ts_ptr = &ts;
     77   }
     78   int result = __pselect6(fd_count, read_fds, write_fds, error_fds, ts_ptr, NULL);
     79   if (tv != NULL) {
     80     timeval_from_timespec(*tv, ts);
     81   }
     82   return result;
     83 }
     84 
     85 int pselect(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds,
     86             const timespec* ts, const sigset_t* ss) {
     87   timespec mutable_ts;
     88   timespec* mutable_ts_ptr = NULL;
     89   if (ts != NULL) {
     90     mutable_ts = *ts;
     91     mutable_ts_ptr = &mutable_ts;
     92   }
     93 
     94   kernel_sigset_t kernel_ss;
     95   kernel_sigset_t* kernel_ss_ptr = NULL;
     96   if (ss != NULL) {
     97     kernel_ss.set(ss);
     98     kernel_ss_ptr = &kernel_ss;
     99   }
    100 
    101   // The Linux kernel only handles 6 arguments and this system call really needs 7,
    102   // so the last argument is a void* pointing to:
    103   struct pselect6_extra_data_t {
    104     uintptr_t ss_addr;
    105     size_t ss_len;
    106   };
    107   pselect6_extra_data_t extra_data;
    108   extra_data.ss_addr = reinterpret_cast<uintptr_t>(kernel_ss_ptr);
    109   extra_data.ss_len = sizeof(kernel_ss);
    110 
    111   return __pselect6(fd_count, read_fds, write_fds, error_fds, mutable_ts_ptr, &extra_data);
    112 }
    113