xref: /freebsd/crypto/openssh/openbsd-compat/bsd-poll.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
1 /*
2  * Copyright (c) 2004, 2005, 2007 Darren Tucker (dtucker at zip com au).
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "includes.h"
18 #if !defined(HAVE_PPOLL) || !defined(HAVE_POLL) || defined(BROKEN_POLL)
19 
20 #include <sys/types.h>
21 #include <sys/time.h>
22 #ifdef HAVE_SYS_PARAM_H
23 # include <sys/param.h>
24 #endif
25 #ifdef HAVE_SYS_SELECT_H
26 # include <sys/select.h>
27 #endif
28 
29 #include <errno.h>
30 #include <signal.h>
31 #include <stdlib.h>
32 #include <unistd.h>
33 #include "bsd-poll.h"
34 
35 #if !defined(HAVE_PPOLL) || defined(BROKEN_POLL)
36 /*
37  * A minimal implementation of ppoll(2), built on top of pselect(2).
38  *
39  * Only supports POLLIN, POLLOUT and POLLPRI flags in pfd.events and
40  * revents. Notably POLLERR, POLLHUP and POLLNVAL are not supported.
41  *
42  * Supports pfd.fd = -1 meaning "unused" although it's not standard.
43  */
44 
45 int
46 ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *tmoutp,
47     const sigset_t *sigmask)
48 {
49 	nfds_t i;
50 	int ret, fd, maxfd = 0;
51 	fd_set readfds, writefds, exceptfds;
52 
53 	for (i = 0; i < nfds; i++) {
54 		fd = fds[i].fd;
55 		if (fd != -1 && fd >= FD_SETSIZE) {
56 			errno = EINVAL;
57 			return -1;
58 		}
59 		maxfd = MAX(maxfd, fd);
60 	}
61 
62 	/* populate event bit vectors for the events we're interested in */
63 	FD_ZERO(&readfds);
64 	FD_ZERO(&writefds);
65 	FD_ZERO(&exceptfds);
66 	for (i = 0; i < nfds; i++) {
67 		fd = fds[i].fd;
68 		if (fd == -1)
69 			continue;
70 		if (fds[i].events & POLLIN)
71 			FD_SET(fd, &readfds);
72 		if (fds[i].events & POLLOUT)
73 			FD_SET(fd, &writefds);
74 		if (fds[i].events & POLLPRI)
75 			FD_SET(fd, &exceptfds);
76 	}
77 
78 	ret = pselect(maxfd + 1, &readfds, &writefds, &exceptfds, tmoutp, sigmask);
79 
80 	/* scan through select results and set poll() flags */
81 	for (i = 0; i < nfds; i++) {
82 		fd = fds[i].fd;
83 		fds[i].revents = 0;
84 		if (fd == -1)
85 			continue;
86 		if ((fds[i].events & POLLIN) && FD_ISSET(fd, &readfds))
87 			fds[i].revents |= POLLIN;
88 		if ((fds[i].events & POLLOUT) && FD_ISSET(fd, &writefds))
89 			fds[i].revents |= POLLOUT;
90 		if ((fds[i].events & POLLPRI) && FD_ISSET(fd, &exceptfds))
91 			fds[i].revents |= POLLPRI;
92 	}
93 
94 	return ret;
95 }
96 #endif /* !HAVE_PPOLL || BROKEN_POLL */
97 
98 #if !defined(HAVE_POLL) || defined(BROKEN_POLL)
99 int
100 poll(struct pollfd *fds, nfds_t nfds, int timeout)
101 {
102 	struct timespec ts, *tsp = NULL;
103 
104 	/* poll timeout is msec, ppoll is timespec (sec + nsec) */
105 	if (timeout >= 0) {
106 		ts.tv_sec = timeout / 1000;
107 		ts.tv_nsec = (timeout % 1000) * 1000000;
108 		tsp = &ts;
109 	}
110 
111 	return ppoll(fds, nfds, tsp, NULL);
112 }
113 #endif /* !HAVE_POLL || BROKEN_POLL */
114 
115 #endif /* !HAVE_PPOLL || !HAVE_POLL || BROKEN_POLL */
116