1/**
2 * \file socket.c
3 * \brief Socket helper routines
4 * \author Abramo Bagnara <abramo@alsa-project.org>
5 * \date 2003
6 */
7/*
8 *  Socket helper routines
9 *  Copyright (c) 2003 by Abramo Bagnara <abramo@alsa-project.org>
10 *
11 *
12 *   This library is free software; you can redistribute it and/or modify
13 *   it under the terms of the GNU Lesser General Public License as
14 *   published by the Free Software Foundation; either version 2.1 of
15 *   the License, or (at your option) any later version.
16 *
17 *   This program is distributed in the hope that it will be useful,
18 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
19 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20 *   GNU Lesser General Public License for more details.
21 *
22 *   You should have received a copy of the GNU Lesser General Public
23 *   License along with this library; if not, write to the Free Software
24 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
25 *
26 */
27
28#include <stdio.h>
29#include <stdlib.h>
30#include <stddef.h>
31#include <unistd.h>
32#include <string.h>
33#include <sys/socket.h>
34#include <sys/uio.h>
35#include <sys/un.h>
36#include <netinet/in.h>
37#include <sys/ioctl.h>
38#include <net/if.h>
39#include <netdb.h>
40#include "local.h"
41
42#ifndef DOC_HIDDEN
43int snd_send_fd(int sock, void *data, size_t len, int fd)
44{
45	int ret;
46	size_t cmsg_len = CMSG_LEN(sizeof(int));
47	struct cmsghdr *cmsg = alloca(cmsg_len);
48	int *fds = (int *) CMSG_DATA(cmsg);
49	struct msghdr msghdr;
50	struct iovec vec;
51
52	vec.iov_base = (void *)&data;
53	vec.iov_len = len;
54
55	cmsg->cmsg_len = cmsg_len;
56	cmsg->cmsg_level = SOL_SOCKET;
57	cmsg->cmsg_type = SCM_RIGHTS;
58	*fds = fd;
59
60	msghdr.msg_name = NULL;
61	msghdr.msg_namelen = 0;
62	msghdr.msg_iov = &vec;
63 	msghdr.msg_iovlen = 1;
64	msghdr.msg_control = cmsg;
65	msghdr.msg_controllen = cmsg_len;
66	msghdr.msg_flags = 0;
67
68	ret = sendmsg(sock, &msghdr, 0 );
69	if (ret < 0) {
70		SYSERR("sendmsg failed");
71		return -errno;
72	}
73	return ret;
74}
75
76int snd_receive_fd(int sock, void *data, size_t len, int *fd)
77{
78	int ret;
79	size_t cmsg_len = CMSG_LEN(sizeof(int));
80	struct cmsghdr *cmsg = alloca(cmsg_len);
81	int *fds = (int *) CMSG_DATA(cmsg);
82	struct msghdr msghdr;
83	struct iovec vec;
84
85	vec.iov_base = (void *)&data;
86	vec.iov_len = len;
87
88	cmsg->cmsg_len = cmsg_len;
89	cmsg->cmsg_level = SOL_SOCKET;
90	cmsg->cmsg_type = SCM_RIGHTS;
91	*fds = -1;
92
93	msghdr.msg_name = NULL;
94	msghdr.msg_namelen = 0;
95	msghdr.msg_iov = &vec;
96	msghdr.msg_iovlen = 1;
97	msghdr.msg_control = cmsg;
98	msghdr.msg_controllen = cmsg_len;
99	msghdr.msg_flags = 0;
100
101	ret = recvmsg(sock, &msghdr, 0);
102	if (ret < 0) {
103		SYSERR("recvmsg failed");
104		return -errno;
105	}
106	*fd = *fds;
107	return ret;
108}
109
110int snd_is_local(struct hostent *hent)
111{
112	int s;
113	int err;
114	struct ifconf conf;
115	size_t numreqs = 10;
116	size_t i;
117	struct in_addr *haddr = (struct in_addr*) hent->h_addr_list[0];
118
119	s = socket(PF_INET, SOCK_STREAM, 0);
120	if (s < 0) {
121		SYSERR("socket failed");
122		return -errno;
123	}
124
125	conf.ifc_len = numreqs * sizeof(struct ifreq);
126	conf.ifc_buf = malloc((unsigned int) conf.ifc_len);
127	if (! conf.ifc_buf)
128		return -ENOMEM;
129	while (1) {
130		err = ioctl(s, SIOCGIFCONF, &conf);
131		if (err < 0) {
132			SYSERR("SIOCGIFCONF failed");
133			return -errno;
134		}
135		if ((size_t)conf.ifc_len < numreqs * sizeof(struct ifreq))
136			break;
137		numreqs *= 2;
138		conf.ifc_len = numreqs * sizeof(struct ifreq);
139		conf.ifc_buf = realloc(conf.ifc_buf, (unsigned int) conf.ifc_len);
140		if (! conf.ifc_buf)
141			return -ENOMEM;
142	}
143	numreqs = conf.ifc_len / sizeof(struct ifreq);
144	for (i = 0; i < numreqs; ++i) {
145		struct ifreq *req = &conf.ifc_req[i];
146		struct sockaddr_in *s_in = (struct sockaddr_in *)&req->ifr_addr;
147		s_in->sin_family = AF_INET;
148		err = ioctl(s, SIOCGIFADDR, req);
149		if (err < 0)
150			continue;
151		if (haddr->s_addr == s_in->sin_addr.s_addr)
152			break;
153	}
154	close(s);
155	free(conf.ifc_buf);
156	return i < numreqs;
157}
158#endif
159