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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 #include <errno.h>
30 #include <sys/poll.h>
31 #include <sys/select.h>
32 
33 #include "private/bionic_time_conversions.h"
34 #include "private/sigrtmin.h"
35 #include "private/SigSetConverter.h"
36 
37 extern "C" int __ppoll(pollfd*, unsigned int, timespec*, const sigset64_t*, size_t);
38 extern "C" int __pselect6(int, fd_set*, fd_set*, fd_set*, timespec*, void*);
39 
poll(pollfd * fds,nfds_t fd_count,int ms)40 int poll(pollfd* fds, nfds_t fd_count, int ms) {
41   timespec ts;
42   timespec* ts_ptr = nullptr;
43   if (ms >= 0) {
44     timespec_from_ms(ts, ms);
45     ts_ptr = &ts;
46   }
47   return __ppoll(fds, fd_count, ts_ptr, nullptr, 0);
48 }
49 
ppoll(pollfd * fds,nfds_t fd_count,const timespec * ts,const sigset_t * ss)50 int ppoll(pollfd* fds, nfds_t fd_count, const timespec* ts, const sigset_t* ss) {
51   // The underlying `__ppoll` system call only takes `sigset64_t`.
52   SigSetConverter set;
53   sigset64_t* ss_ptr = nullptr;
54   if (ss != nullptr) {
55     set = {};
56     set.sigset = *ss;
57     ss_ptr = &set.sigset64;
58   }
59   return ppoll64(fds, fd_count, ts, ss_ptr);
60 }
61 
ppoll64(pollfd * fds,nfds_t fd_count,const timespec * ts,const sigset64_t * ss)62 int ppoll64(pollfd* fds, nfds_t fd_count, const timespec* ts, const sigset64_t* ss) {
63   // The underlying __ppoll system call modifies its `struct timespec` argument.
64   timespec mutable_ts;
65   timespec* mutable_ts_ptr = nullptr;
66   if (ts != nullptr) {
67     mutable_ts = *ts;
68     mutable_ts_ptr = &mutable_ts;
69   }
70 
71   sigset64_t mutable_ss;
72   sigset64_t* mutable_ss_ptr = nullptr;
73   if (ss != nullptr) {
74     mutable_ss = filter_reserved_signals(*ss, SIG_SETMASK);
75     mutable_ss_ptr = &mutable_ss;
76   }
77 
78   return __ppoll(fds, fd_count, mutable_ts_ptr, mutable_ss_ptr, sizeof(*mutable_ss_ptr));
79 }
80 
select(int fd_count,fd_set * read_fds,fd_set * write_fds,fd_set * error_fds,timeval * tv)81 int select(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds, timeval* tv) {
82   timespec ts;
83   timespec* ts_ptr = nullptr;
84   if (tv != nullptr) {
85     if (!timespec_from_timeval(ts, *tv)) {
86       errno = EINVAL;
87       return -1;
88     }
89     ts_ptr = &ts;
90   }
91   int result = __pselect6(fd_count, read_fds, write_fds, error_fds, ts_ptr, nullptr);
92   if (tv != nullptr) {
93     timeval_from_timespec(*tv, ts);
94   }
95   return result;
96 }
97 
pselect(int fd_count,fd_set * read_fds,fd_set * write_fds,fd_set * error_fds,const timespec * ts,const sigset_t * ss)98 int pselect(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds,
99             const timespec* ts, const sigset_t* ss) {
100   // The underlying `__pselect6` system call only takes `sigset64_t`.
101   SigSetConverter set;
102   sigset64_t* ss_ptr = nullptr;
103   if (ss != nullptr) {
104     set = {};
105     set.sigset = *ss;
106     ss_ptr = &set.sigset64;
107   }
108   return pselect64(fd_count, read_fds, write_fds, error_fds, ts, ss_ptr);
109 }
110 
pselect64(int fd_count,fd_set * read_fds,fd_set * write_fds,fd_set * error_fds,const timespec * ts,const sigset64_t * ss)111 int pselect64(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds,
112               const timespec* ts, const sigset64_t* ss) {
113   // The underlying __pselect6 system call modifies its `struct timespec` argument.
114   timespec mutable_ts;
115   timespec* mutable_ts_ptr = nullptr;
116   if (ts != nullptr) {
117     mutable_ts = *ts;
118     mutable_ts_ptr = &mutable_ts;
119   }
120 
121   sigset64_t mutable_ss;
122   sigset64_t* mutable_ss_ptr = nullptr;
123   if (ss != nullptr) {
124     mutable_ss = filter_reserved_signals(*ss, SIG_SETMASK);
125     mutable_ss_ptr = &mutable_ss;
126   }
127 
128   // The Linux kernel only handles 6 arguments and this system call really needs 7,
129   // so the last argument is a void* pointing to:
130   struct pselect6_extra_data_t {
131     uintptr_t ss_addr;
132     size_t ss_len;
133   };
134   pselect6_extra_data_t extra_data;
135   extra_data.ss_addr = reinterpret_cast<uintptr_t>(mutable_ss_ptr);
136   extra_data.ss_len = sizeof(*mutable_ss_ptr);
137 
138   return __pselect6(fd_count, read_fds, write_fds, error_fds, mutable_ts_ptr, &extra_data);
139 }
140