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 /* ancilliary 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 #include <sys/socket.h>
47 #include <netinet/in.h>
50 /* Required yet non-standard cmsg functions */
52 # define CMSG_ALIGN(len) (((len) + sizeof(intptr_t)-1) & ~(sizeof(intptr_t)-1))
55 # define CMSG_SPACE(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + CMSG_ALIGN(len))
58 # define CMSG_LEN(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + (len))
61 #if defined(__OS2__) && !defined(ALIGN)
62 /* CMSG_NXTHDR requires this */
63 # define ALIGN(p) _ALIGN(p)
67 * Receive a file descriptor from another process
69 static int recv_fd (int p)
75 char buf[CMSG_SPACE (sizeof (fd))];
81 hdr.msg_control = buf;
82 hdr.msg_controllen = sizeof (buf);
85 iov.iov_len = sizeof (val);
87 if (recvmsg (p, &hdr, 0) != sizeof (val))
90 for (cmsg = CMSG_FIRSTHDR (&hdr); cmsg != NULL;
91 cmsg = CMSG_NXTHDR (&hdr, cmsg))
93 if ((cmsg->cmsg_level == SOL_SOCKET)
94 && (cmsg->cmsg_type = SCM_RIGHTS)
95 && (cmsg->cmsg_len >= CMSG_LEN (sizeof (fd))))
97 memcpy (&fd, CMSG_DATA (cmsg), sizeof (fd));
107 * Tries to obtain a bound TCP socket from the root process
109 int rootwrap_bind (int family, int socktype, int protocol,
110 const struct sockaddr *addr, size_t alen)
112 /* can't use libvlc */
113 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
114 struct sockaddr_storage ss;
117 const char *sockenv = getenv ("VLC_ROOTWRAP_SOCK");
119 sock = atoi (sockenv);
129 if (alen < sizeof (struct sockaddr_in))
138 if (alen < sizeof (struct sockaddr_in6))
147 errno = EAFNOSUPPORT;
151 if (family != addr->sa_family)
153 errno = EAFNOSUPPORT;
157 /* Only TCP is implemented at the moment */
158 if ((socktype != SOCK_STREAM)
159 || (protocol && (protocol != IPPROTO_TCP)))
165 memset (&ss, 0, sizeof (ss));
166 memcpy (&ss, addr, (alen > sizeof (ss)) ? sizeof (ss) : alen);
168 pthread_mutex_lock (&mutex);
169 if (send (sock, &ss, sizeof (ss), 0) != sizeof (ss))
173 pthread_mutex_unlock (&mutex);
178 int rootwrap_bind (int family, int socktype, int protocol,
179 const struct sockaddr *addr, size_t alen)
190 #endif /* ENABLE_ROOTWRAP */