1 /*****************************************************************************
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 #include <stdlib.h> /* exit() */
29 #include <sys/types.h>
33 #include <sys/socket.h>
35 #include <sys/resource.h> /* getrlimit() */
38 #include <netinet/in.h>
40 #if defined (AF_INET6) && !defined (IPV6_V6ONLY)
41 # warning Uho, your IPv6 support is broken and has been disabled. Fix your C library.
46 # define AF_LOCAL AF_UNIX
49 static inline int is_allowed_port (uint16_t port)
52 return (port == 80) || (port == 443) || (port == 554);
56 static inline int send_err (int fd, int err)
58 return send (fd, &err, sizeof (err), 0) == sizeof (err) ? 0 : -1;
62 * Send a file descriptor to another process
64 static int send_fd (int p, int fd)
69 char buf[CMSG_SPACE (sizeof (fd))];
76 hdr.msg_control = buf;
77 hdr.msg_controllen = sizeof (buf);
80 iov.iov_len = sizeof (val);
82 cmsg = CMSG_FIRSTHDR (&hdr);
83 cmsg->cmsg_level = SOL_SOCKET;
84 cmsg->cmsg_type = SCM_RIGHTS;
85 cmsg->cmsg_len = CMSG_LEN (sizeof (fd));
86 memcpy (CMSG_DATA (cmsg), &fd, sizeof (fd));
87 hdr.msg_controllen = cmsg->cmsg_len;
89 return sendmsg (p, &hdr, 0) == sizeof (val) ? 0 : -1;
94 * Background process run as root to open privileged TCP ports.
96 static void rootprocess (int fd)
98 struct sockaddr_storage ss;
100 while (recv (fd, &ss, sizeof (ss), 0) == sizeof (ss))
105 switch (ss.ss_family)
108 if (!is_allowed_port (((struct sockaddr_in *)&ss)->sin_port))
110 if (send_err (fd, EACCES))
114 len = sizeof (struct sockaddr_in);
119 if (!is_allowed_port (((struct sockaddr_in6 *)&ss)->sin6_port))
121 if (send_err (fd, EACCES))
125 len = sizeof (struct sockaddr_in6);
130 if (send_err (fd, EAFNOSUPPORT))
135 sock = socket (ss.ss_family, SOCK_STREAM, IPPROTO_TCP);
140 setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof (val));
142 if (ss.ss_family == AF_INET6)
143 setsockopt (sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof (val));
145 if (bind (sock, (struct sockaddr *)&ss, len) == 0)
152 send_err (fd, errno);
157 * - use libcap if available,
161 int main (int argc, char *argv[])
163 /* Support for dynamically opening RTSP, HTTP and HTTP/SSL ports */
166 if (socketpair (AF_LOCAL, SOCK_STREAM, 0, pair))
169 goto error; /* we want 0, 1 and 2 open */
179 int null = open ("/dev/null", O_RDWR);
189 rootprocess (pair[1]);
198 snprintf (buf, sizeof (buf), "%d", pair[0]);
199 setenv ("VLC_ROOTWRAP_SOCK", buf, 1);
201 /* Support for real-time priorities */
204 rlim.rlim_max = rlim.rlim_cur = sched_get_priority_min (SCHED_RR) + 24;
205 setrlimit (RLIMIT_RTPRIO, &rlim);
210 if (!setuid (0)) /* sanity check: we cannot get root back */
213 /* Yeah, the user can force to execute just about anything from here.
214 * But we've dropped privileges, so it does not matter. */
215 if (strlen (argv[0]) < sizeof ("-wrapper"))
217 argv[0][strlen (argv[0]) - strlen ("-wrapper")] = '\0';
220 if (execvp (argv[0], argv))