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 <platform/bionic/reserved_signals.h>
34 
35 #include "private/bionic_time_conversions.h"
36 #include "private/SigSetConverter.h"
37 
38 extern "C" int __ppoll(pollfd*, unsigned int, timespec*, const sigset64_t*, size_t);
39 extern "C" int __pselect6(int, fd_set*, fd_set*, fd_set*, timespec*, void*);
40 
poll(pollfd * fds,nfds_t fd_count,int ms)41 int poll(pollfd* fds, nfds_t fd_count, int ms) {
42   timespec ts;
43   timespec* ts_ptr = nullptr;
44   if (ms >= 0) {
45     timespec_from_ms(ts, ms);
46     ts_ptr = &ts;
47   }
48   return __ppoll(fds, fd_count, ts_ptr, nullptr, 0);
49 }
50 
ppoll(pollfd * fds,nfds_t fd_count,const timespec * ts,const sigset_t * ss)51 int ppoll(pollfd* fds, nfds_t fd_count, const timespec* ts, const sigset_t* ss) {
52   // The underlying `__ppoll` system call only takes `sigset64_t`.
53   SigSetConverter set;
54   sigset64_t* ss_ptr = nullptr;
55   if (ss != nullptr) {
56     set = {};
57     set.sigset = *ss;
58     ss_ptr = &set.sigset64;
59   }
60   return ppoll64(fds, fd_count, ts, ss_ptr);
61 }
62 
ppoll64(pollfd * fds,nfds_t fd_count,const timespec * ts,const sigset64_t * ss)63 int ppoll64(pollfd* fds, nfds_t fd_count, const timespec* ts, const sigset64_t* ss) {
64   // The underlying __ppoll system call modifies its `struct timespec` argument.
65   timespec mutable_ts;
66   timespec* mutable_ts_ptr = nullptr;
67   if (ts != nullptr) {
68     mutable_ts = *ts;
69     mutable_ts_ptr = &mutable_ts;
70   }
71 
72   sigset64_t mutable_ss;
73   sigset64_t* mutable_ss_ptr = nullptr;
74   if (ss != nullptr) {
75     mutable_ss = filter_reserved_signals(*ss, SIG_SETMASK);
76     mutable_ss_ptr = &mutable_ss;
77   }
78 
79   return __ppoll(fds, fd_count, mutable_ts_ptr, mutable_ss_ptr, sizeof(*mutable_ss_ptr));
80 }
81 
select(int fd_count,fd_set * read_fds,fd_set * write_fds,fd_set * error_fds,timeval * tv)82 int select(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds, timeval* tv) {
83   timespec ts;
84   timespec* ts_ptr = nullptr;
85   if (tv != nullptr) {
86     if (!timespec_from_timeval(ts, *tv)) {
87       errno = EINVAL;
88       return -1;
89     }
90     ts_ptr = &ts;
91   }
92   int result = __pselect6(fd_count, read_fds, write_fds, error_fds, ts_ptr, nullptr);
93   if (tv != nullptr) {
94     timeval_from_timespec(*tv, ts);
95   }
96   return result;
97 }
98 
pselect(int fd_count,fd_set * read_fds,fd_set * write_fds,fd_set * error_fds,const timespec * ts,const sigset_t * ss)99 int pselect(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds,
100             const timespec* ts, const sigset_t* ss) {
101   // The underlying `__pselect6` system call only takes `sigset64_t`.
102   SigSetConverter set;
103   sigset64_t* ss_ptr = nullptr;
104   if (ss != nullptr) {
105     set = {};
106     set.sigset = *ss;
107     ss_ptr = &set.sigset64;
108   }
109   return pselect64(fd_count, read_fds, write_fds, error_fds, ts, ss_ptr);
110 }
111 
pselect64(int fd_count,fd_set * read_fds,fd_set * write_fds,fd_set * error_fds,const timespec * ts,const sigset64_t * ss)112 int pselect64(int fd_count, fd_set* read_fds, fd_set* write_fds, fd_set* error_fds,
113               const timespec* ts, const sigset64_t* ss) {
114   // The underlying __pselect6 system call modifies its `struct timespec` argument.
115   timespec mutable_ts;
116   timespec* mutable_ts_ptr = nullptr;
117   if (ts != nullptr) {
118     mutable_ts = *ts;
119     mutable_ts_ptr = &mutable_ts;
120   }
121 
122   sigset64_t mutable_ss;
123   sigset64_t* mutable_ss_ptr = nullptr;
124   if (ss != nullptr) {
125     mutable_ss = filter_reserved_signals(*ss, SIG_SETMASK);
126     mutable_ss_ptr = &mutable_ss;
127   }
128 
129   // The Linux kernel only handles 6 arguments and this system call really needs 7,
130   // so the last argument is a void* pointing to:
131   struct pselect6_extra_data_t {
132     uintptr_t ss_addr;
133     size_t ss_len;
134   };
135   pselect6_extra_data_t extra_data;
136   extra_data.ss_addr = reinterpret_cast<uintptr_t>(mutable_ss_ptr);
137   extra_data.ss_len = sizeof(*mutable_ss_ptr);
138 
139   return __pselect6(fd_count, read_fds, write_fds, error_fds, mutable_ts_ptr, &extra_data);
140 }
141