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 #include <sys/poll.h>
30 #include <sys/select.h>
31 
32 #include "private/bionic_time_conversions.h"
33 #include "private/kernel_sigset_t.h"
34 
35 extern "C" int __ppoll(pollfd*, unsigned int, timespec*, const kernel_sigset_t*, size_t);
36 extern "C" int __pselect6(int, fd_set*, fd_set*, fd_set*, timespec*, void*);
37 
poll(pollfd * fds,nfds_t fd_count,int ms)38 int poll(pollfd* fds, nfds_t fd_count, int ms) {
39   timespec ts;
40   timespec* ts_ptr = NULL;
41   if (ms >= 0) {
42     timespec_from_ms(ts, ms);
43     ts_ptr = &ts;
44   }
45   return __ppoll(fds, fd_count, ts_ptr, NULL, 0);
46 }
47 
ppoll(pollfd * fds,nfds_t fd_count,const timespec * ts,const sigset_t * ss)48 int ppoll(pollfd* fds, nfds_t fd_count, const timespec* ts, const sigset_t* ss) {
49   timespec mutable_ts;
50   timespec* mutable_ts_ptr = NULL;
51   if (ts != NULL) {
52     mutable_ts = *ts;
53     mutable_ts_ptr = &mutable_ts;
54   }
55 
56   kernel_sigset_t kernel_ss;
57   kernel_sigset_t* kernel_ss_ptr = NULL;
58   if (ss != NULL) {
59     kernel_ss.set(ss);
60     kernel_ss_ptr = &kernel_ss;
61   }
62 
63   return __ppoll(fds, fd_count, mutable_ts_ptr, kernel_ss_ptr, sizeof(kernel_ss));
64 }
65 
select(int fd_count,fd_set * read_fds,fd_set * write_fds,fd_set * error_fds,timeval * tv)66 int select(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds, timeval* tv) {
67   timespec ts;
68   timespec* ts_ptr = NULL;
69   if (tv != NULL) {
70     if (!timespec_from_timeval(ts, *tv)) {
71       errno = EINVAL;
72       return -1;
73     }
74     ts_ptr = &ts;
75   }
76   int result = __pselect6(fd_count, read_fds, write_fds, error_fds, ts_ptr, NULL);
77   if (tv != NULL) {
78     timeval_from_timespec(*tv, ts);
79   }
80   return result;
81 }
82 
pselect(int fd_count,fd_set * read_fds,fd_set * write_fds,fd_set * error_fds,const timespec * ts,const sigset_t * ss)83 int pselect(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds,
84             const timespec* ts, const sigset_t* ss) {
85   timespec mutable_ts;
86   timespec* mutable_ts_ptr = NULL;
87   if (ts != NULL) {
88     mutable_ts = *ts;
89     mutable_ts_ptr = &mutable_ts;
90   }
91 
92   kernel_sigset_t kernel_ss;
93   kernel_sigset_t* kernel_ss_ptr = NULL;
94   if (ss != NULL) {
95     kernel_ss.set(ss);
96     kernel_ss_ptr = &kernel_ss;
97   }
98 
99   // The Linux kernel only handles 6 arguments and this system call really needs 7,
100   // so the last argument is a void* pointing to:
101   struct pselect6_extra_data_t {
102     uintptr_t ss_addr;
103     size_t ss_len;
104   };
105   pselect6_extra_data_t extra_data;
106   extra_data.ss_addr = reinterpret_cast<uintptr_t>(kernel_ss_ptr);
107   extra_data.ss_len = sizeof(kernel_ss);
108 
109   return __pselect6(fd_count, read_fds, write_fds, error_fds, mutable_ts_ptr, &extra_data);
110 }
111