xref: /freebsd/lib/libsys/recvmmsg.c (revision c57c26179033f64c2011a2d2a904ee3fa62e826a)
1 /*
2  * Copyright (c) 2016 Boris Astardzhiev, Smartcom-Bulgaria AD
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  * 1. Redistributions of source code must retain the above copyright
9  *    notice(s), this list of conditions and the following disclaimer as
10  *    the first lines of this file unmodified other than the possible
11  *    addition of one or more copyright notices.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice(s), this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
21  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
24  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
26  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
27  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <errno.h>
33 #include <poll.h>
34 #include <stddef.h>
35 #include "libc_private.h"
36 
37 ssize_t
38 recvmmsg(int s, struct mmsghdr *__restrict msgvec, size_t vlen, int flags,
39     const struct timespec *__restrict timeout)
40 {
41 	struct pollfd pfd[1];
42 	size_t i, rcvd;
43 	ssize_t ret;
44 	int res;
45 	short ev;
46 
47 	if (timeout != NULL) {
48 		pfd[0].fd = s;
49 		pfd[0].revents = 0;
50 		pfd[0].events = ev = POLLIN | POLLRDNORM | POLLRDBAND |
51 		    POLLPRI;
52 		res = ppoll(&pfd[0], 1, timeout, NULL);
53 		if (res == -1 || res == 0)
54 			return (res);
55 		if (pfd[0].revents & POLLNVAL) {
56 			errno = EBADF;
57 			return (-1);
58 		}
59 		if ((pfd[0].revents & ev) == 0) {
60 			errno = ETIMEDOUT;
61 			return (-1);
62 		}
63 	}
64 
65 	ret = __sys_recvmsg(s, &msgvec[0].msg_hdr, flags);
66 	if (ret == -1)
67 		return (ret);
68 
69 	msgvec[0].msg_len = ret;
70 
71 	/*
72 	 * Do non-blocking receive for second and later messages if
73 	 * WAITFORONE is set.
74 	 */
75 	if (flags & MSG_WAITFORONE)
76 		flags |= MSG_DONTWAIT;
77 
78 	rcvd = 1;
79 	for (i = rcvd; i < vlen; i++, rcvd++) {
80 		ret = __sys_recvmsg(s, &msgvec[i].msg_hdr, flags);
81 		if (ret == -1) {
82 			/* We have received messages. Let caller know
83 			 * about the data received, socket error is
84 			 * returned on next invocation.
85 			 */
86 			return (rcvd);
87 		}
88 
89 		/* Save received bytes. */
90 		msgvec[i].msg_len = ret;
91 	}
92 
93 	return (rcvd);
94 }
95