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 it
7 * under the terms of the GNU Lesser General Public License as published by
8 * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
19 *****************************************************************************/
25 #define _XPG4_2 /* ancillary data on Solaris */
27 #if !defined (_WIN32) && !defined (__OS2__)
28 # define ENABLE_ROOTWRAP 1
33 int rootwrap_bind (int, int, int, const struct sockaddr
*, size_t);
37 #ifdef ENABLE_ROOTWRAP
42 #include <sys/types.h>
44 #ifdef HAVE_SYS_SOCKET_H
45 #include <sys/socket.h>
49 #include <netinet/in.h>
52 /* Required yet non-standard cmsg functions */
54 # define CMSG_ALIGN(len) (((len) + sizeof(intptr_t)-1) & ~(sizeof(intptr_t)-1))
57 # define CMSG_SPACE(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + CMSG_ALIGN(len))
60 # define CMSG_LEN(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + (len))
62 #if !defined(MSG_NOSIGNAL)
63 /* If the other end of the pipe hangs up and MSG_NOSIGNAL is missing, the
64 * process will get a (likely fatal) SIGPIPE signal. Then again, the other end
65 * can screw us up in various ways already (e.g. not answer to deadlock). */
66 # define MSG_NOSIGNAL 0
69 #if defined(__OS2__) && !defined(ALIGN)
70 /* CMSG_NXTHDR requires this */
71 # define ALIGN(p) _ALIGN(p)
75 * Receive a file descriptor from another process
77 static int recv_fd (int p
)
83 char buf
[CMSG_SPACE (sizeof (fd
))];
89 hdr
.msg_control
= buf
;
90 hdr
.msg_controllen
= sizeof (buf
);
93 iov
.iov_len
= sizeof (val
);
95 if (recvmsg (p
, &hdr
, 0) != sizeof (val
))
98 for (cmsg
= CMSG_FIRSTHDR (&hdr
); cmsg
!= NULL
;
99 cmsg
= CMSG_NXTHDR (&hdr
, cmsg
))
101 if ((cmsg
->cmsg_level
== SOL_SOCKET
)
102 && (cmsg
->cmsg_type
== SCM_RIGHTS
)
103 && (cmsg
->cmsg_len
>= CMSG_LEN (sizeof (fd
))))
105 memcpy (&fd
, CMSG_DATA (cmsg
), sizeof (fd
));
115 * Tries to obtain a bound TCP socket from the root process
117 int rootwrap_bind (int family
, int socktype
, int protocol
,
118 const struct sockaddr
*addr
, size_t alen
)
120 /* can't use libvlc */
121 static pthread_mutex_t mutex
= PTHREAD_MUTEX_INITIALIZER
;
122 struct sockaddr_storage ss
;
125 const char *sockenv
= getenv ("VLC_ROOTWRAP_SOCK");
127 sock
= atoi (sockenv
);
137 if (alen
< sizeof (struct sockaddr_in
))
146 if (alen
< sizeof (struct sockaddr_in6
))
155 errno
= EAFNOSUPPORT
;
159 if (family
!= addr
->sa_family
)
161 errno
= EAFNOSUPPORT
;
165 /* Only TCP is implemented at the moment */
166 if ((socktype
!= SOCK_STREAM
)
167 || (protocol
&& (protocol
!= IPPROTO_TCP
)))
173 memset (&ss
, 0, sizeof (ss
));
174 memcpy (&ss
, addr
, (alen
> sizeof (ss
)) ? sizeof (ss
) : alen
);
176 pthread_mutex_lock (&mutex
);
177 if (send (sock
, &ss
, sizeof (ss
), MSG_NOSIGNAL
) != sizeof (ss
))
179 pthread_mutex_unlock (&mutex
);
184 pthread_mutex_unlock (&mutex
);
189 int rootwrap_bind (int family
, int socktype
, int protocol
,
190 const struct sockaddr
*addr
, size_t alen
)
201 #endif /* ENABLE_ROOTWRAP */