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 saved_errno, ret, fd, maxfd = 0;
51 	fd_set *readfds = NULL, *writefds = NULL, *exceptfds = NULL;
52 	size_t nmemb;
53 
54 	for (i = 0; i < nfds; i++) {
55 		fd = fds[i].fd;
56 		if (fd != -1 && fd >= FD_SETSIZE) {
57 			errno = EINVAL;
58 			return -1;
59 		}
60 		maxfd = MAX(maxfd, fd);
61 	}
62 
63 	nmemb = howmany(maxfd + 1 , NFDBITS);
64 	if ((readfds = calloc(nmemb, sizeof(fd_mask))) == NULL ||
65 	    (writefds = calloc(nmemb, sizeof(fd_mask))) == NULL ||
66 	    (exceptfds = calloc(nmemb, sizeof(fd_mask))) == NULL) {
67 		saved_errno = ENOMEM;
68 		ret = -1;
69 		goto out;
70 	}
71 
72 	/* populate event bit vectors for the events we're interested in */
73 	for (i = 0; i < nfds; i++) {
74 		fd = fds[i].fd;
75 		if (fd == -1)
76 			continue;
77 		if (fds[i].events & POLLIN)
78 			FD_SET(fd, readfds);
79 		if (fds[i].events & POLLOUT)
80 			FD_SET(fd, writefds);
81 		if (fds[i].events & POLLPRI)
82 			FD_SET(fd, exceptfds);
83 	}
84 
85 	ret = pselect(maxfd + 1, readfds, writefds, exceptfds, tmoutp, sigmask);
86 	saved_errno = errno;
87 
88 	/* scan through select results and set poll() flags */
89 	for (i = 0; i < nfds; i++) {
90 		fd = fds[i].fd;
91 		fds[i].revents = 0;
92 		if (fd == -1)
93 			continue;
94 		if ((fds[i].events & POLLIN) && FD_ISSET(fd, readfds))
95 			fds[i].revents |= POLLIN;
96 		if ((fds[i].events & POLLOUT) && FD_ISSET(fd, writefds))
97 			fds[i].revents |= POLLOUT;
98 		if ((fds[i].events & POLLPRI) && FD_ISSET(fd, exceptfds))
99 			fds[i].revents |= POLLPRI;
100 	}
101 
102 out:
103 	free(readfds);
104 	free(writefds);
105 	free(exceptfds);
106 	if (ret == -1)
107 		errno = saved_errno;
108 	return ret;
109 }
110 #endif /* !HAVE_PPOLL || BROKEN_POLL */
111 
112 #if !defined(HAVE_POLL) || defined(BROKEN_POLL)
113 int
114 poll(struct pollfd *fds, nfds_t nfds, int timeout)
115 {
116 	struct timespec ts, *tsp = NULL;
117 
118 	/* poll timeout is msec, ppoll is timespec (sec + nsec) */
119 	if (timeout >= 0) {
120 		ts.tv_sec = timeout / 1000;
121 		ts.tv_nsec = (timeout % 1000) * 1000000;
122 		tsp = &ts;
123 	}
124 
125 	return ppoll(fds, nfds, tsp, NULL);
126 }
127 #endif /* !HAVE_POLL || BROKEN_POLL */
128 
129 #endif /* !HAVE_PPOLL || !HAVE_POLL || BROKEN_POLL */
130