1 /*****************************************************************************
2 * rootbind.c: bind to reserved ports through the root wrapper
3 *****************************************************************************
4 * Copyright © 2005-2008 Rémi Denis-Courmont
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
19 *****************************************************************************/
25 #if !defined (WIN32) && !defined (SYS_BEOS)
26 # define ENABLE_ROOTWRAP 1
31 int rootwrap_bind (int, int, int, const struct sockaddr *, size_t);
35 #ifdef ENABLE_ROOTWRAP
40 #include <sys/types.h>
42 #include <sys/socket.h>
45 #include <netinet/in.h>
48 /* Required yet non-standard cmsg functions */
50 # define CMSG_ALIGN(len) (((len) + sizeof(intptr_t)-1) & ~(sizeof(intptr_t)-1))
53 # define CMSG_SPACE(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + CMSG_ALIGN(len))
56 # define CMSG_LEN(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + (len))
60 * Receive a file descriptor from another process
62 static int recv_fd (int p)
68 char buf[CMSG_SPACE (sizeof (fd))];
74 hdr.msg_control = buf;
75 hdr.msg_controllen = sizeof (buf);
78 iov.iov_len = sizeof (val);
80 if (recvmsg (p, &hdr, 0) != sizeof (val))
83 for (cmsg = CMSG_FIRSTHDR (&hdr); cmsg != NULL;
84 cmsg = CMSG_NXTHDR (&hdr, cmsg))
86 if ((cmsg->cmsg_level == SOL_SOCKET)
87 && (cmsg->cmsg_type = SCM_RIGHTS)
88 && (cmsg->cmsg_len >= CMSG_LEN (sizeof (fd))))
90 memcpy (&fd, CMSG_DATA (cmsg), sizeof (fd));
100 * Tries to obtain a bound TCP socket from the root process
102 int rootwrap_bind (int family, int socktype, int protocol,
103 const struct sockaddr *addr, size_t alen)
105 /* can't use libvlc */
106 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
107 struct sockaddr_storage ss;
110 const char *sockenv = getenv ("VLC_ROOTWRAP_SOCK");
112 sock = atoi (sockenv);
122 if (alen < sizeof (struct sockaddr_in))
131 if (alen < sizeof (struct sockaddr_in6))
140 errno = EAFNOSUPPORT;
144 if (family != addr->sa_family)
146 errno = EAFNOSUPPORT;
150 /* Only TCP is implemented at the moment */
151 if ((socktype != SOCK_STREAM)
152 || (protocol && (protocol != IPPROTO_TCP)))
158 memset (&ss, 0, sizeof (ss));
159 memcpy (&ss, addr, (alen > sizeof (ss)) ? sizeof (ss) : alen);
161 pthread_mutex_lock (&mutex);
162 if (send (sock, &ss, sizeof (ss), 0) != sizeof (ss))
166 pthread_mutex_unlock (&mutex);
171 int rootwrap_bind (int family, int socktype, int protocol,
172 const struct sockaddr *addr, size_t alen)
183 #endif /* ENABLE_ROOTWRAP */