Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	sbin/isakmpd/monitor.c	Lines:	0	389	0.0 %
Date:	2017-11-13	Branches:	0	192	0.0 %


/* $OpenBSD: monitor.c,v 1.74 2015/08/20 22:02:21 deraadt Exp $	 */

/*
 * Copyright (c) 2003 H�kan Olsson.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <netinet/in.h>

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>

#include <regex.h>
#include <keynote.h>

#include "conf.h"
#include "log.h"
#include "monitor.h"
#include "policy.h"
#include "ui.h"
#include "util.h"
#include "pf_key_v2.h"

struct monitor_state {
	pid_t           pid;
	int             s;
	char            root[PATH_MAX];
} m_state;

extern char *pid_file;

extern void	set_slave_signals(void);

/* Private functions.  */
static void	must_read(void *, size_t);
static void	must_write(const void *, size_t);

static void	m_priv_getfd(void);
static void	m_priv_setsockopt(void);
static void	m_priv_req_readdir(void);
static void	m_priv_bind(void);
static void	m_priv_pfkey_open(void);
static int	m_priv_local_sanitize_path(char *, size_t, int);
static int	m_priv_check_sockopt(int, int);
static int	m_priv_check_bind(const struct sockaddr *, socklen_t);

static void	set_monitor_signals(void);
static void	sig_pass_to_chld(int);

/*
 * Public functions, unprivileged.
 */

/* Setup monitor context, fork, drop child privs.  */
pid_t
monitor_init(int debug)
{
	struct passwd  *pw;
	int             p[2];

	bzero(&m_state, sizeof m_state);

	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) != 0)
		log_fatal("monitor_init: socketpair() failed");

	pw = getpwnam(ISAKMPD_PRIVSEP_USER);
	if (pw == NULL)
		log_fatalx("monitor_init: getpwnam(\"%s\") failed",
		    ISAKMPD_PRIVSEP_USER);
	strlcpy(m_state.root, pw->pw_dir, sizeof m_state.root);

	set_monitor_signals();
	m_state.pid = fork();

	if (m_state.pid == -1)
		log_fatal("monitor_init: fork of unprivileged child failed");
	if (m_state.pid == 0) {
		/* The child process drops privileges. */
		set_slave_signals();

		if (chroot(pw->pw_dir) != 0 || chdir("/") != 0)
			log_fatal("monitor_init: chroot failed");

		if (setgroups(1, &pw->pw_gid) == -1 ||
		    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
		    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
			log_fatal("monitor_init: can't drop privileges");

		m_state.s = p[0];
		close(p[1]);

		LOG_DBG((LOG_MISC, 10,
		    "monitor_init: privileges dropped for child process"));
	} else {
		/* Privileged monitor. */
		setproctitle("monitor [priv]");

		m_state.s = p[1];
		close(p[0]);
	}

	/* With "-dd", stop and wait here. For gdb "attach" etc.  */
	if (debug > 1) {
		log_print("monitor_init: stopped %s PID %d fd %d%s",
		    m_state.pid ? "priv" : "child", getpid(), m_state.s,
		    m_state.pid ? ", waiting for SIGCONT" : "");
		kill(getpid(), SIGSTOP);	/* Wait here for SIGCONT.  */
		if (m_state.pid)
			kill(m_state.pid, SIGCONT); /* Continue child.  */
	}

	return m_state.pid;
}

void
monitor_exit(int code)
{
	int status;
	pid_t pid;

	if (m_state.pid != 0) {
		/* When called from the monitor, kill slave and wait for it  */
		kill(m_state.pid, SIGTERM);

		do {
			pid = waitpid(m_state.pid, &status, 0);
		} while (pid == -1 && errno == EINTR);

		/* Remove FIFO and pid files.  */
		unlink(ui_fifo);
		unlink(pid_file);
	}

	close(m_state.s);
	exit(code);
}

int
monitor_pf_key_v2_open(void)
{
	int	err, cmd;

	cmd = MONITOR_PFKEY_OPEN;
	must_write(&cmd, sizeof cmd);

	must_read(&err, sizeof err);
	if (err < 0) {
		log_error("monitor_pf_key_v2_open: parent could not create "
		    "PF_KEY socket");
		return -1;
	}
	pf_key_v2_socket = mm_receive_fd(m_state.s);
	if (pf_key_v2_socket < 0) {
		log_error("monitor_pf_key_v2_open: mm_receive_fd() failed");
		return -1;
	}

	return pf_key_v2_socket;
}

int
monitor_open(const char *path, int flags, mode_t mode)
{
	size_t	len;
	int	fd, err, cmd;
	char	pathreal[PATH_MAX];

	if (path[0] == '/')
		strlcpy(pathreal, path, sizeof pathreal);
	else
		snprintf(pathreal, sizeof pathreal, "%s/%s", m_state.root,
		    path);

	cmd = MONITOR_GET_FD;
	must_write(&cmd, sizeof cmd);

	len = strlen(pathreal);
	must_write(&len, sizeof len);
	must_write(&pathreal, len);

	must_write(&flags, sizeof flags);
	must_write(&mode, sizeof mode);

	must_read(&err, sizeof err);
	if (err != 0) {
		errno = err;
		return -1;
	}

	fd = mm_receive_fd(m_state.s);
	if (fd < 0) {
		log_error("monitor_open: mm_receive_fd () failed");
		return -1;
	}

	return fd;
}

FILE *
monitor_fopen(const char *path, const char *mode)
{
	FILE	*fp;
	int	 fd, flags = 0, saved_errno;
	mode_t	 mask, cur_umask;

	/* Only the child process is supposed to run this.  */
	if (m_state.pid)
		log_fatal("[priv] bad call to monitor_fopen");

	switch (mode[0]) {
	case 'r':
		flags = (mode[1] == '+' ? O_RDWR : O_RDONLY);
		break;
	case 'w':
		flags = (mode[1] == '+' ? O_RDWR : O_WRONLY) | O_CREAT |
		    O_TRUNC;
		break;
	case 'a':
		flags = (mode[1] == '+' ? O_RDWR : O_WRONLY) | O_CREAT |
		    O_APPEND;
		break;
	default:
		log_fatal("monitor_fopen: bad call");
	}

	cur_umask = umask(0);
	(void)umask(cur_umask);
	mask = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
	mask &= ~cur_umask;

	fd = monitor_open(path, flags, mask);
	if (fd < 0)
		return NULL;

	/* Got the fd, attach a FILE * to it.  */
	fp = fdopen(fd, mode);
	if (!fp) {
		log_error("monitor_fopen: fdopen() failed");
		saved_errno = errno;
		close(fd);
		errno = saved_errno;
		return NULL;
	}
	return fp;
}

int
monitor_stat(const char *path, struct stat *sb)
{
	int	fd, r, saved_errno;

	/* O_NONBLOCK is needed for stat'ing fifos. */
	fd = monitor_open(path, O_RDONLY | O_NONBLOCK, 0);
	if (fd < 0)
		return -1;

	r = fstat(fd, sb);
	saved_errno = errno;
	close(fd);
	errno = saved_errno;
	return r;
}

int
monitor_setsockopt(int s, int level, int optname, const void *optval,
    socklen_t optlen)
{
	int	ret, err, cmd;

	cmd = MONITOR_SETSOCKOPT;
	must_write(&cmd, sizeof cmd);
	if (mm_send_fd(m_state.s, s)) {
		log_print("monitor_setsockopt: read/write error");
		return -1;
	}

	must_write(&level, sizeof level);
	must_write(&optname, sizeof optname);
	must_write(&optlen, sizeof optlen);
	must_write(optval, optlen);

	must_read(&err, sizeof err);
	must_read(&ret, sizeof ret);
	if (err != 0)
		errno = err;
	return ret;
}

int
monitor_bind(int s, const struct sockaddr *name, socklen_t namelen)
{
	int	ret, err, cmd;

	cmd = MONITOR_BIND;
	must_write(&cmd, sizeof cmd);
	if (mm_send_fd(m_state.s, s)) {
		log_print("monitor_bind: read/write error");
		return -1;
	}

	must_write(&namelen, sizeof namelen);
	must_write(name, namelen);

	must_read(&err, sizeof err);
	must_read(&ret, sizeof ret);
	if (err != 0)
		errno = err;
	return ret;
}

int
monitor_req_readdir(const char *filename)
{
	int cmd, err;
	size_t len;

	cmd = MONITOR_REQ_READDIR;
	must_write(&cmd, sizeof cmd);

	len = strlen(filename);
	must_write(&len, sizeof len);
	must_write(filename, len);

	must_read(&err, sizeof err);
	if (err == -1)
		must_read(&errno, sizeof errno);

	return err;
}

int
monitor_readdir(char *file, size_t size)
{
	int fd;
	size_t len;

	must_read(&len, sizeof len);
	if (len == 0)
		return -1;
	if (len >= size)
		log_fatal("monitor_readdir: received bad length from monitor");
	must_read(file, len);
	file[len] = '\0';
	fd = mm_receive_fd(m_state.s);
	return fd;
}

void
monitor_init_done(void)
{
	int	cmd;

	cmd = MONITOR_INIT_DONE;
	must_write(&cmd, sizeof cmd);
}

/*
 * Start of code running with privileges (the monitor process).
 */

static void
set_monitor_signals(void)
{
	int n;

	for (n = 1; n < _NSIG; n++)
		signal(n, SIG_DFL);

	/* Forward some signals to the child. */
	signal(SIGTERM, sig_pass_to_chld);
	signal(SIGHUP, sig_pass_to_chld);
	signal(SIGUSR1, sig_pass_to_chld);
}

static void
sig_pass_to_chld(int sig)
{
	int	oerrno = errno;

	if (m_state.pid > 0)
		kill(m_state.pid, sig);
	errno = oerrno;
}

/* This function is where the privileged process waits(loops) indefinitely.  */
void
monitor_loop(int debug)
{
	int	 msgcode;

	if (!debug)
		log_to(0);

	for (;;) {
		must_read(&msgcode, sizeof msgcode);

		switch (msgcode) {
		case MONITOR_GET_FD:
			m_priv_getfd();
			break;

		case MONITOR_PFKEY_OPEN:
			LOG_DBG((LOG_MISC, 80,
			    "monitor_loop: MONITOR_PFKEY_OPEN"));
			m_priv_pfkey_open();
			break;

		case MONITOR_SETSOCKOPT:
			LOG_DBG((LOG_MISC, 80,
			    "monitor_loop: MONITOR_SETSOCKOPT"));
			m_priv_setsockopt();
			break;

		case MONITOR_BIND:
			LOG_DBG((LOG_MISC, 80,
			    "monitor_loop: MONITOR_BIND"));
			m_priv_bind();
			break;

		case MONITOR_REQ_READDIR:
			LOG_DBG((LOG_MISC, 80,
			    "monitor_loop: MONITOR_REQ_READDIR"));
			m_priv_req_readdir();
			break;

		case MONITOR_INIT_DONE:
			LOG_DBG((LOG_MISC, 80,
			    "monitor_loop: MONITOR_INIT_DONE"));
			break;

		case MONITOR_SHUTDOWN:
			LOG_DBG((LOG_MISC, 80,
			    "monitor_loop: MONITOR_SHUTDOWN"));
			break;

		default:
			log_print("monitor_loop: got unknown code %d",
			    msgcode);
		}
	}

	exit(0);
}


/* Privileged: called by monitor_loop.  */
static void
m_priv_pfkey_open(void)
{
	int	fd, err = 0;

	fd = pf_key_v2_open();
	if (fd < 0)
		err = -1;

	must_write(&err, sizeof err);

	if (fd > 0 && mm_send_fd(m_state.s, fd)) {
		log_error("m_priv_pfkey_open: read/write operation failed");
		close(fd);
		return;
	}
	close(fd);
}

/* Privileged: called by monitor_loop.  */
static void
m_priv_getfd(void)
{
	char	path[PATH_MAX];
	size_t	len;
	int	v, flags, ret;
	int	err = 0;
	mode_t	mode;

	must_read(&len, sizeof len);
	if (len == 0 || len >= sizeof path)
		log_fatal("m_priv_getfd: invalid pathname length");

	must_read(path, len);
	path[len] = '\0';
	if (strlen(path) != len)
		log_fatal("m_priv_getfd: invalid pathname");

	must_read(&flags, sizeof flags);
	must_read(&mode, sizeof mode);

	if ((ret = m_priv_local_sanitize_path(path, sizeof path, flags))
	    != 0) {
		if (ret == 1)
			log_print("m_priv_getfd: illegal path \"%s\"", path);
		err = EACCES;
		v = -1;
	} else {
		if ((v = open(path, flags, mode)) == -1)
			err = errno;
	}

	must_write(&err, sizeof err);

	if (v != -1) {
		if (mm_send_fd(m_state.s, v) == -1)
			log_error("m_priv_getfd: sending fd failed");
		close(v);
	}
}

/* Privileged: called by monitor_loop.  */
static void
m_priv_setsockopt(void)
{
	int		 sock, level, optname, v;
	int		 err = 0;
	char		*optval = 0;
	socklen_t	 optlen;

	sock = mm_receive_fd(m_state.s);
	if (sock < 0) {
		log_print("m_priv_setsockopt: read/write error");
		return;
	}

	must_read(&level, sizeof level);
	must_read(&optname, sizeof optname);
	must_read(&optlen, sizeof optlen);

	optval = malloc(optlen);
	if (!optval) {
		log_print("m_priv_setsockopt: malloc failed");
		close(sock);
		return;
	}

	must_read(optval, optlen);

	if (m_priv_check_sockopt(level, optname) != 0) {
		err = EACCES;
		v = -1;
	} else {
		v = setsockopt(sock, level, optname, optval, optlen);
		if (v < 0)
			err = errno;
	}

	close(sock);
	sock = -1;

	must_write(&err, sizeof err);
	must_write(&v, sizeof v);

	free(optval);
	return;
}

/* Privileged: called by monitor_loop.  */
static void
m_priv_bind(void)
{
	int		 sock, v, err = 0;
	struct sockaddr *name = 0;
	socklen_t        namelen;

	sock = mm_receive_fd(m_state.s);
	if (sock < 0) {
		log_print("m_priv_bind: read/write error");
		return;
	}

	must_read(&namelen, sizeof namelen);
	name = malloc(namelen);
	if (!name) {
		log_print("m_priv_bind: malloc failed");
		close(sock);
		return;
	}
	must_read((char *)name, namelen);

	if (m_priv_check_bind(name, namelen) != 0) {
		err = EACCES;
		v = -1;
	} else {
		v = bind(sock, name, namelen);
		if (v < 0) {
			log_error("m_priv_bind: bind(%d,%p,%d) returned %d",
			    sock, name, namelen, v);
			err = errno;
		}
	}

	close(sock);
	sock = -1;

	must_write(&err, sizeof err);
	must_write(&v, sizeof v);

	free(name);
	return;
}

/*
 * Help functions, used by both privileged and unprivileged code
 */

/*
 * Read data with the assertion that it all must come through, or else abort
 * the process.  Based on atomicio() from openssh.
 */
static void
must_read(void *buf, size_t n)
{
        char *s = buf;
	size_t pos = 0;
        ssize_t res;

        while (n > pos) {
                res = read(m_state.s, s + pos, n - pos);
                switch (res) {
                case -1:
                        if (errno == EINTR || errno == EAGAIN)
                                continue;
                case 0:
			monitor_exit(0);
                default:
                        pos += res;
                }
        }
}

/*
 * Write data with the assertion that it all has to be written, or else abort
 * the process.  Based on atomicio() from openssh.
 */
static void
must_write(const void *buf, size_t n)
{
        const char *s = buf;
	size_t pos = 0;
	ssize_t res;

        while (n > pos) {
                res = write(m_state.s, s + pos, n - pos);
                switch (res) {
                case -1:
                        if (errno == EINTR || errno == EAGAIN)
                                continue;
                case 0:
			monitor_exit(0);
                default:
                        pos += res;
                }
        }
}

/* Check that path/mode is permitted.  */
static int
m_priv_local_sanitize_path(char *path, size_t pmax, int flags)
{
	char new_path[PATH_MAX], var_run[PATH_MAX];

	/*
	 * We only permit paths starting with
	 *  /etc/isakmpd/	(read only)
	 *  /var/run/		(rw)
         */

	if (realpath(path, new_path) == NULL ||
	    realpath("/var/run", var_run) == NULL) {
		/*
                 * We could not decide whether the path is ok or not.
                 * Indicate this be returning 2.
		 */
		if (errno == ENOENT)
			return 2;
		goto bad_path;
	}
	strlcat(var_run, "/", sizeof(var_run));

	if (strncmp(var_run, new_path, strlen(var_run)) == 0)
		return 0;

	if (strncmp(ISAKMPD_ROOT, new_path, strlen(ISAKMPD_ROOT)) == 0 &&
	    (flags & O_ACCMODE) == O_RDONLY)
		return 0;

bad_path:
	return 1;
}

/* Check setsockopt */
static int
m_priv_check_sockopt(int level, int name)
{
	switch (level) {
		/* These are allowed */
		case SOL_SOCKET:
		case IPPROTO_IP:
		case IPPROTO_IPV6:
		break;

	default:
		log_print("m_priv_check_sockopt: Illegal level %d", level);
		return 1;
	}

	switch (name) {
		/* These are allowed */
	case SO_REUSEPORT:
	case SO_REUSEADDR:
	case IP_AUTH_LEVEL:
	case IP_ESP_TRANS_LEVEL:
	case IP_ESP_NETWORK_LEVEL:
	case IP_IPCOMP_LEVEL:
	case IPV6_AUTH_LEVEL:
	case IPV6_ESP_TRANS_LEVEL:
	case IPV6_ESP_NETWORK_LEVEL:
	case IPV6_IPCOMP_LEVEL:
		break;

	default:
		log_print("m_priv_check_sockopt: Illegal option name %d",
		    name);
		return 1;
	}

	return 0;
}

/* Check bind */
static int
m_priv_check_bind(const struct sockaddr *sa, socklen_t salen)
{
	in_port_t       port;

	if (sa == NULL) {
		log_print("NULL address");
		return 1;
	}
	if (SA_LEN(sa) != salen) {
		log_print("Length mismatch: %lu %lu", (unsigned long)sa->sa_len,
		    (unsigned long)salen);
		return 1;
	}
	switch (sa->sa_family) {
	case AF_INET:
		if (salen != sizeof(struct sockaddr_in)) {
			log_print("Invalid inet address length");
			return 1;
		}
		port = ((const struct sockaddr_in *)sa)->sin_port;
		break;
	case AF_INET6:
		if (salen != sizeof(struct sockaddr_in6)) {
			log_print("Invalid inet6 address length");
			return 1;
		}
		port = ((const struct sockaddr_in6 *)sa)->sin6_port;
		break;
	default:
		log_print("Unknown address family");
		return 1;
	}

	port = ntohs(port);

	if (port != ISAKMP_PORT_DEFAULT && port < 1024) {
		log_print("Disallowed port %u", port);
		return 1;
	}
	return 0;
}

static void
m_priv_req_readdir()
{
	size_t len;
	char path[PATH_MAX];
	DIR *dp;
	struct dirent *file;
	struct stat sb;
	int off, size, fd, ret, serrno;

	must_read(&len, sizeof len);
	if (len == 0 || len >= sizeof path)
		log_fatal("m_priv_req_readdir: invalid pathname length");
	must_read(path, len);
	path[len] = '\0';
	if (strlen(path) != len)
		log_fatal("m_priv_req_readdir: invalid pathname");

	off = strlen(path);
	size = sizeof path - off;

	if ((dp = opendir(path)) == NULL) {
		serrno = errno;
		ret = -1;
		must_write(&ret, sizeof ret);
		must_write(&serrno, sizeof serrno);
		return;
	}

	/* report opendir() success */
	ret = 0;
	must_write(&ret, sizeof ret);

	while ((file = readdir(dp)) != NULL) {
		strlcpy(path + off, file->d_name, size);

		if (m_priv_local_sanitize_path(path, sizeof path, O_RDONLY)
		    != 0)
			continue;
		fd = open(path, O_RDONLY, 0);
		if (fd == -1) {
			log_error("m_priv_req_readdir: open "
			    "(\"%s\", O_RDONLY, 0) failed", path);
			continue;
		}
		if ((fstat(fd, &sb) == -1) ||
		    !(S_ISREG(sb.st_mode) || S_ISLNK(sb.st_mode))) {
			close(fd);
			continue;
		}

		len = strlen(path);
		must_write(&len, sizeof len);
		must_write(path, len);

		mm_send_fd(m_state.s, fd);
		close(fd);
	}
	closedir(dp);

	len = 0;
	must_write(&len, sizeof len);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: monitor.c,v 1.74 2015/08/20 22:02:21 deraadt Exp $ */
2
3			/*
4			* Copyright (c) 2003 H�kan Olsson. All rights reserved.
5			*
6			* Redistribution and use in source and binary forms, with or without
7			* modification, are permitted provided that the following conditions
8			* are met:
9			* 1. Redistributions of source code must retain the above copyright
10			* notice, this list of conditions and the following disclaimer.
11			* 2. Redistributions in binary form must reproduce the above copyright
12			* notice, this list of conditions and the following disclaimer in the
13			* documentation and/or other materials provided with the distribution.
14			*
15			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16			* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18			* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19			* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21			* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22			* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23			* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24			* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25			*/
26
27			#include <sys/types.h>
28			#include <sys/socket.h>
29			#include <sys/ioctl.h>
30			#include <sys/stat.h>
31			#include <sys/wait.h>
32			#include <netinet/in.h>
33
34			#include <dirent.h>
35			#include <errno.h>
36			#include <fcntl.h>
37			#include <pwd.h>
38			#include <signal.h>
39			#include <stdlib.h>
40			#include <string.h>
41			#include <unistd.h>
42			#include <limits.h>
43
44			#include <regex.h>
45			#include <keynote.h>
46
47			#include "conf.h"
48			#include "log.h"
49			#include "monitor.h"
50			#include "policy.h"
51			#include "ui.h"
52			#include "util.h"
53			#include "pf_key_v2.h"
54
55			struct monitor_state {
56			pid_t pid;
57			int s;
58			char root[PATH_MAX];
59			} m_state;
60
61			extern char *pid_file;
62
63			extern void set_slave_signals(void);
64
65			/* Private functions. */
66			static void must_read(void *, size_t);
67			static void must_write(const void *, size_t);
68
69			static void m_priv_getfd(void);
70			static void m_priv_setsockopt(void);
71			static void m_priv_req_readdir(void);
72			static void m_priv_bind(void);
73			static void m_priv_pfkey_open(void);
74			static int m_priv_local_sanitize_path(char *, size_t, int);
75			static int m_priv_check_sockopt(int, int);
76			static int m_priv_check_bind(const struct sockaddr *, socklen_t);
77
78			static void set_monitor_signals(void);
79			static void sig_pass_to_chld(int);
80
81			/*
82			* Public functions, unprivileged.
83			*/
84
85			/* Setup monitor context, fork, drop child privs. */
86			pid_t
87			monitor_init(int debug)
88			{
89			struct passwd *pw;
90			int p[2];
91
92			bzero(&m_state, sizeof m_state);
93
94			if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) != 0)
95			log_fatal("monitor_init: socketpair() failed");
96
97			pw = getpwnam(ISAKMPD_PRIVSEP_USER);
98			if (pw == NULL)
99			log_fatalx("monitor_init: getpwnam(\"%s\") failed",
100			ISAKMPD_PRIVSEP_USER);
101			strlcpy(m_state.root, pw->pw_dir, sizeof m_state.root);
102
103			set_monitor_signals();
104			m_state.pid = fork();
105
106			if (m_state.pid == -1)
107			log_fatal("monitor_init: fork of unprivileged child failed");
108			if (m_state.pid == 0) {
109			/* The child process drops privileges. */
110			set_slave_signals();
111
112			if (chroot(pw->pw_dir) != 0 \|\| chdir("/") != 0)
113			log_fatal("monitor_init: chroot failed");
114
115			if (setgroups(1, &pw->pw_gid) == -1 \|\|
116			setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) \|\|
117			setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
118			log_fatal("monitor_init: can't drop privileges");
119
120			m_state.s = p[0];
121			close(p[1]);
122
123			LOG_DBG((LOG_MISC, 10,
124			"monitor_init: privileges dropped for child process"));
125			} else {
126			/* Privileged monitor. */
127			setproctitle("monitor [priv]");
128
129			m_state.s = p[1];
130			close(p[0]);
131			}
132
133			/* With "-dd", stop and wait here. For gdb "attach" etc. */
134			if (debug > 1) {
135			log_print("monitor_init: stopped %s PID %d fd %d%s",
136			m_state.pid ? "priv" : "child", getpid(), m_state.s,
137			m_state.pid ? ", waiting for SIGCONT" : "");
138			kill(getpid(), SIGSTOP); /* Wait here for SIGCONT. */
139			if (m_state.pid)
140			kill(m_state.pid, SIGCONT); /* Continue child. */
141			}
142
143			return m_state.pid;
144			}
145
146			void
147			monitor_exit(int code)
148			{
149			int status;
150			pid_t pid;
151
152			if (m_state.pid != 0) {
153			/* When called from the monitor, kill slave and wait for it */
154			kill(m_state.pid, SIGTERM);
155
156			do {
157			pid = waitpid(m_state.pid, &status, 0);
158			} while (pid == -1 && errno == EINTR);
159
160			/* Remove FIFO and pid files. */
161			unlink(ui_fifo);
162			unlink(pid_file);
163			}
164
165			close(m_state.s);
166			exit(code);
167			}
168
169			int
170			monitor_pf_key_v2_open(void)
171			{
172			int err, cmd;
173
174			cmd = MONITOR_PFKEY_OPEN;
175			must_write(&cmd, sizeof cmd);
176
177			must_read(&err, sizeof err);
178			if (err < 0) {
179			log_error("monitor_pf_key_v2_open: parent could not create "
180			"PF_KEY socket");
181			return -1;
182			}
183			pf_key_v2_socket = mm_receive_fd(m_state.s);
184			if (pf_key_v2_socket < 0) {
185			log_error("monitor_pf_key_v2_open: mm_receive_fd() failed");
186			return -1;
187			}
188
189			return pf_key_v2_socket;
190			}
191
192			int
193			monitor_open(const char *path, int flags, mode_t mode)
194			{
195			size_t len;
196			int fd, err, cmd;
197			char pathreal[PATH_MAX];
198
199			if (path[0] == '/')
200			strlcpy(pathreal, path, sizeof pathreal);
201			else
202			snprintf(pathreal, sizeof pathreal, "%s/%s", m_state.root,
203			path);
204
205			cmd = MONITOR_GET_FD;
206			must_write(&cmd, sizeof cmd);
207
208			len = strlen(pathreal);
209			must_write(&len, sizeof len);
210			must_write(&pathreal, len);
211
212			must_write(&flags, sizeof flags);
213			must_write(&mode, sizeof mode);
214
215			must_read(&err, sizeof err);
216			if (err != 0) {
217			errno = err;
218			return -1;
219			}
220
221			fd = mm_receive_fd(m_state.s);
222			if (fd < 0) {
223			log_error("monitor_open: mm_receive_fd () failed");
224			return -1;
225			}
226
227			return fd;
228			}
229
230			FILE *
231			monitor_fopen(const char path, const char mode)
232			{
233			FILE *fp;
234			int fd, flags = 0, saved_errno;
235			mode_t mask, cur_umask;
236
237			/* Only the child process is supposed to run this. */
238			if (m_state.pid)
239			log_fatal("[priv] bad call to monitor_fopen");
240
241			switch (mode[0]) {
242			case 'r':
243			flags = (mode[1] == '+' ? O_RDWR : O_RDONLY);
244			break;
245			case 'w':
246			flags = (mode[1] == '+' ? O_RDWR : O_WRONLY) \| O_CREAT \|
247			O_TRUNC;
248			break;
249			case 'a':
250			flags = (mode[1] == '+' ? O_RDWR : O_WRONLY) \| O_CREAT \|
251			O_APPEND;
252			break;
253			default:
254			log_fatal("monitor_fopen: bad call");
255			}
256
257			cur_umask = umask(0);
258			(void)umask(cur_umask);
259			mask = S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP \| S_IROTH \| S_IWOTH;
260			mask &= ~cur_umask;
261
262			fd = monitor_open(path, flags, mask);
263			if (fd < 0)
264			return NULL;
265
266			/* Got the fd, attach a FILE * to it. */
267			fp = fdopen(fd, mode);
268			if (!fp) {
269			log_error("monitor_fopen: fdopen() failed");
270			saved_errno = errno;
271			close(fd);
272			errno = saved_errno;
273			return NULL;
274			}
275			return fp;
276			}
277
278			int
279			monitor_stat(const char path, struct stat sb)
280			{
281			int fd, r, saved_errno;
282
283			/* O_NONBLOCK is needed for stat'ing fifos. */
284			fd = monitor_open(path, O_RDONLY \| O_NONBLOCK, 0);
285			if (fd < 0)
286			return -1;
287
288			r = fstat(fd, sb);
289			saved_errno = errno;
290			close(fd);
291			errno = saved_errno;
292			return r;
293			}
294
295			int
296			monitor_setsockopt(int s, int level, int optname, const void *optval,
297			socklen_t optlen)
298			{
299			int ret, err, cmd;
300
301			cmd = MONITOR_SETSOCKOPT;
302			must_write(&cmd, sizeof cmd);
303			if (mm_send_fd(m_state.s, s)) {
304			log_print("monitor_setsockopt: read/write error");
305			return -1;
306			}
307
308			must_write(&level, sizeof level);
309			must_write(&optname, sizeof optname);
310			must_write(&optlen, sizeof optlen);
311			must_write(optval, optlen);
312
313			must_read(&err, sizeof err);
314			must_read(&ret, sizeof ret);
315			if (err != 0)
316			errno = err;
317			return ret;
318			}
319
320			int
321			monitor_bind(int s, const struct sockaddr *name, socklen_t namelen)
322			{
323			int ret, err, cmd;
324
325			cmd = MONITOR_BIND;
326			must_write(&cmd, sizeof cmd);
327			if (mm_send_fd(m_state.s, s)) {
328			log_print("monitor_bind: read/write error");
329			return -1;
330			}
331
332			must_write(&namelen, sizeof namelen);
333			must_write(name, namelen);
334
335			must_read(&err, sizeof err);
336			must_read(&ret, sizeof ret);
337			if (err != 0)
338			errno = err;
339			return ret;
340			}
341
342			int
343			monitor_req_readdir(const char *filename)
344			{
345			int cmd, err;
346			size_t len;
347
348			cmd = MONITOR_REQ_READDIR;
349			must_write(&cmd, sizeof cmd);
350
351			len = strlen(filename);
352			must_write(&len, sizeof len);
353			must_write(filename, len);
354
355			must_read(&err, sizeof err);
356			if (err == -1)
357			must_read(&errno, sizeof errno);
358
359			return err;
360			}
361
362			int
363			monitor_readdir(char *file, size_t size)
364			{
365			int fd;
366			size_t len;
367
368			must_read(&len, sizeof len);
369			if (len == 0)
370			return -1;
371			if (len >= size)
372			log_fatal("monitor_readdir: received bad length from monitor");
373			must_read(file, len);
374			file[len] = '\0';
375			fd = mm_receive_fd(m_state.s);
376			return fd;
377			}
378
379			void
380			monitor_init_done(void)
381			{
382			int cmd;
383
384			cmd = MONITOR_INIT_DONE;
385			must_write(&cmd, sizeof cmd);
386			}
387
388			/*
389			* Start of code running with privileges (the monitor process).
390			*/
391
392			static void
393			set_monitor_signals(void)
394			{
395			int n;
396
397			for (n = 1; n < _NSIG; n++)
398			signal(n, SIG_DFL);
399
400			/* Forward some signals to the child. */
401			signal(SIGTERM, sig_pass_to_chld);
402			signal(SIGHUP, sig_pass_to_chld);
403			signal(SIGUSR1, sig_pass_to_chld);
404			}
405
406			static void
407			sig_pass_to_chld(int sig)
408			{
409			int oerrno = errno;
410
411			if (m_state.pid > 0)
412			kill(m_state.pid, sig);
413			errno = oerrno;
414			}
415
416			/* This function is where the privileged process waits(loops) indefinitely. */
417			void
418			monitor_loop(int debug)
419			{
420			int msgcode;
421
422			if (!debug)
423			log_to(0);
424
425			for (;;) {
426			must_read(&msgcode, sizeof msgcode);
427
428			switch (msgcode) {
429			case MONITOR_GET_FD:
430			m_priv_getfd();
431			break;
432
433			case MONITOR_PFKEY_OPEN:
434			LOG_DBG((LOG_MISC, 80,
435			"monitor_loop: MONITOR_PFKEY_OPEN"));
436			m_priv_pfkey_open();
437			break;
438
439			case MONITOR_SETSOCKOPT:
440			LOG_DBG((LOG_MISC, 80,
441			"monitor_loop: MONITOR_SETSOCKOPT"));
442			m_priv_setsockopt();
443			break;
444
445			case MONITOR_BIND:
446			LOG_DBG((LOG_MISC, 80,
447			"monitor_loop: MONITOR_BIND"));
448			m_priv_bind();
449			break;
450
451			case MONITOR_REQ_READDIR:
452			LOG_DBG((LOG_MISC, 80,
453			"monitor_loop: MONITOR_REQ_READDIR"));
454			m_priv_req_readdir();
455			break;
456
457			case MONITOR_INIT_DONE:
458			LOG_DBG((LOG_MISC, 80,
459			"monitor_loop: MONITOR_INIT_DONE"));
460			break;
461
462			case MONITOR_SHUTDOWN:
463			LOG_DBG((LOG_MISC, 80,
464			"monitor_loop: MONITOR_SHUTDOWN"));
465			break;
466
467			default:
468			log_print("monitor_loop: got unknown code %d",
469			msgcode);
470			}
471			}
472
473			exit(0);
474			}
475
476
477			/* Privileged: called by monitor_loop. */
478			static void
479			m_priv_pfkey_open(void)
480			{
481			int fd, err = 0;
482
483			fd = pf_key_v2_open();
484			if (fd < 0)
485			err = -1;
486
487			must_write(&err, sizeof err);
488
489			if (fd > 0 && mm_send_fd(m_state.s, fd)) {
490			log_error("m_priv_pfkey_open: read/write operation failed");
491			close(fd);
492			return;
493			}
494			close(fd);
495			}
496
497			/* Privileged: called by monitor_loop. */
498			static void
499			m_priv_getfd(void)
500			{
501			char path[PATH_MAX];
502			size_t len;
503			int v, flags, ret;
504			int err = 0;
505			mode_t mode;
506
507			must_read(&len, sizeof len);
508			if (len == 0 \|\| len >= sizeof path)
509			log_fatal("m_priv_getfd: invalid pathname length");
510
511			must_read(path, len);
512			path[len] = '\0';
513			if (strlen(path) != len)
514			log_fatal("m_priv_getfd: invalid pathname");
515
516			must_read(&flags, sizeof flags);
517			must_read(&mode, sizeof mode);
518
519			if ((ret = m_priv_local_sanitize_path(path, sizeof path, flags))
520			!= 0) {
521			if (ret == 1)
522			log_print("m_priv_getfd: illegal path \"%s\"", path);
523			err = EACCES;
524			v = -1;
525			} else {
526			if ((v = open(path, flags, mode)) == -1)
527			err = errno;
528			}
529
530			must_write(&err, sizeof err);
531
532			if (v != -1) {
533			if (mm_send_fd(m_state.s, v) == -1)
534			log_error("m_priv_getfd: sending fd failed");
535			close(v);
536			}
537			}
538
539			/* Privileged: called by monitor_loop. */
540			static void
541			m_priv_setsockopt(void)
542			{
543			int sock, level, optname, v;
544			int err = 0;
545			char *optval = 0;
546			socklen_t optlen;
547
548			sock = mm_receive_fd(m_state.s);
549			if (sock < 0) {
550			log_print("m_priv_setsockopt: read/write error");
551			return;
552			}
553
554			must_read(&level, sizeof level);
555			must_read(&optname, sizeof optname);
556			must_read(&optlen, sizeof optlen);
557
558			optval = malloc(optlen);
559			if (!optval) {
560			log_print("m_priv_setsockopt: malloc failed");
561			close(sock);
562			return;
563			}
564
565			must_read(optval, optlen);
566
567			if (m_priv_check_sockopt(level, optname) != 0) {
568			err = EACCES;
569			v = -1;
570			} else {
571			v = setsockopt(sock, level, optname, optval, optlen);
572			if (v < 0)
573			err = errno;
574			}
575
576			close(sock);
577			sock = -1;
578
579			must_write(&err, sizeof err);
580			must_write(&v, sizeof v);
581
582			free(optval);
583			return;
584			}
585
586			/* Privileged: called by monitor_loop. */
587			static void
588			m_priv_bind(void)
589			{
590			int sock, v, err = 0;
591			struct sockaddr *name = 0;
592			socklen_t namelen;
593
594			sock = mm_receive_fd(m_state.s);
595			if (sock < 0) {
596			log_print("m_priv_bind: read/write error");
597			return;
598			}
599
600			must_read(&namelen, sizeof namelen);
601			name = malloc(namelen);
602			if (!name) {
603			log_print("m_priv_bind: malloc failed");
604			close(sock);
605			return;
606			}
607			must_read((char *)name, namelen);
608
609			if (m_priv_check_bind(name, namelen) != 0) {
610			err = EACCES;
611			v = -1;
612			} else {
613			v = bind(sock, name, namelen);
614			if (v < 0) {
615			log_error("m_priv_bind: bind(%d,%p,%d) returned %d",
616			sock, name, namelen, v);
617			err = errno;
618			}
619			}
620
621			close(sock);
622			sock = -1;
623
624			must_write(&err, sizeof err);
625			must_write(&v, sizeof v);
626
627			free(name);
628			return;
629			}
630
631			/*
632			* Help functions, used by both privileged and unprivileged code
633			*/
634
635			/*
636			* Read data with the assertion that it all must come through, or else abort
637			* the process. Based on atomicio() from openssh.
638			*/
639			static void
640			must_read(void *buf, size_t n)
641			{
642			char *s = buf;
643			size_t pos = 0;
644			ssize_t res;
645
646			while (n > pos) {
647			res = read(m_state.s, s + pos, n - pos);
648			switch (res) {
649			case -1:
650			if (errno == EINTR \|\| errno == EAGAIN)
651			continue;
652			case 0:
653			monitor_exit(0);
654			default:
655			pos += res;
656			}
657			}
658			}
659
660			/*
661			* Write data with the assertion that it all has to be written, or else abort
662			* the process. Based on atomicio() from openssh.
663			*/
664			static void
665			must_write(const void *buf, size_t n)
666			{
667			const char *s = buf;
668			size_t pos = 0;
669			ssize_t res;
670
671			while (n > pos) {
672			res = write(m_state.s, s + pos, n - pos);
673			switch (res) {
674			case -1:
675			if (errno == EINTR \|\| errno == EAGAIN)
676			continue;
677			case 0:
678			monitor_exit(0);
679			default:
680			pos += res;
681			}
682			}
683			}
684
685			/* Check that path/mode is permitted. */
686			static int
687			m_priv_local_sanitize_path(char *path, size_t pmax, int flags)
688			{
689			char new_path[PATH_MAX], var_run[PATH_MAX];
690
691			/*
692			* We only permit paths starting with
693			* /etc/isakmpd/ (read only)
694			* /var/run/ (rw)
695			*/
696
697			if (realpath(path, new_path) == NULL \|\|
698			realpath("/var/run", var_run) == NULL) {
699			/*
700			* We could not decide whether the path is ok or not.
701			* Indicate this be returning 2.
702			*/
703			if (errno == ENOENT)
704			return 2;
705			goto bad_path;
706			}
707			strlcat(var_run, "/", sizeof(var_run));
708
709			if (strncmp(var_run, new_path, strlen(var_run)) == 0)
710			return 0;
711
712			if (strncmp(ISAKMPD_ROOT, new_path, strlen(ISAKMPD_ROOT)) == 0 &&
713			(flags & O_ACCMODE) == O_RDONLY)
714			return 0;
715
716			bad_path:
717			return 1;
718			}
719
720			/* Check setsockopt */
721			static int
722			m_priv_check_sockopt(int level, int name)
723			{
724			switch (level) {
725			/* These are allowed */
726			case SOL_SOCKET:
727			case IPPROTO_IP:
728			case IPPROTO_IPV6:
729			break;
730
731			default:
732			log_print("m_priv_check_sockopt: Illegal level %d", level);
733			return 1;
734			}
735
736			switch (name) {
737			/* These are allowed */
738			case SO_REUSEPORT:
739			case SO_REUSEADDR:
740			case IP_AUTH_LEVEL:
741			case IP_ESP_TRANS_LEVEL:
742			case IP_ESP_NETWORK_LEVEL:
743			case IP_IPCOMP_LEVEL:
744			case IPV6_AUTH_LEVEL:
745			case IPV6_ESP_TRANS_LEVEL:
746			case IPV6_ESP_NETWORK_LEVEL:
747			case IPV6_IPCOMP_LEVEL:
748			break;
749
750			default:
751			log_print("m_priv_check_sockopt: Illegal option name %d",
752			name);
753			return 1;
754			}
755
756			return 0;
757			}
758
759			/* Check bind */
760			static int
761			m_priv_check_bind(const struct sockaddr *sa, socklen_t salen)
762			{
763			in_port_t port;
764
765			if (sa == NULL) {
766			log_print("NULL address");
767			return 1;
768			}
769			if (SA_LEN(sa) != salen) {
770			log_print("Length mismatch: %lu %lu", (unsigned long)sa->sa_len,
771			(unsigned long)salen);
772			return 1;
773			}
774			switch (sa->sa_family) {
775			case AF_INET:
776			if (salen != sizeof(struct sockaddr_in)) {
777			log_print("Invalid inet address length");
778			return 1;
779			}
780			port = ((const struct sockaddr_in *)sa)->sin_port;
781			break;
782			case AF_INET6:
783			if (salen != sizeof(struct sockaddr_in6)) {
784			log_print("Invalid inet6 address length");
785			return 1;
786			}
787			port = ((const struct sockaddr_in6 *)sa)->sin6_port;
788			break;
789			default:
790			log_print("Unknown address family");
791			return 1;
792			}
793
794			port = ntohs(port);
795
796			if (port != ISAKMP_PORT_DEFAULT && port < 1024) {
797			log_print("Disallowed port %u", port);
798			return 1;
799			}
800			return 0;
801			}
802
803			static void
804			m_priv_req_readdir()
805			{
806			size_t len;
807			char path[PATH_MAX];
808			DIR *dp;
809			struct dirent *file;
810			struct stat sb;
811			int off, size, fd, ret, serrno;
812
813			must_read(&len, sizeof len);
814			if (len == 0 \|\| len >= sizeof path)
815			log_fatal("m_priv_req_readdir: invalid pathname length");
816			must_read(path, len);
817			path[len] = '\0';
818			if (strlen(path) != len)
819			log_fatal("m_priv_req_readdir: invalid pathname");
820
821			off = strlen(path);
822			size = sizeof path - off;
823
824			if ((dp = opendir(path)) == NULL) {
825			serrno = errno;
826			ret = -1;
827			must_write(&ret, sizeof ret);
828			must_write(&serrno, sizeof serrno);
829			return;
830			}
831
832			/* report opendir() success */
833			ret = 0;
834			must_write(&ret, sizeof ret);
835
836			while ((file = readdir(dp)) != NULL) {
837			strlcpy(path + off, file->d_name, size);
838
839			if (m_priv_local_sanitize_path(path, sizeof path, O_RDONLY)
840			!= 0)
841			continue;
842			fd = open(path, O_RDONLY, 0);
843			if (fd == -1) {
844			log_error("m_priv_req_readdir: open "
845			"(\"%s\", O_RDONLY, 0) failed", path);
846			continue;
847			}
848			if ((fstat(fd, &sb) == -1) \|\|
849			!(S_ISREG(sb.st_mode) \|\| S_ISLNK(sb.st_mode))) {
850			close(fd);
851			continue;
852			}
853
854			len = strlen(path);
855			must_write(&len, sizeof len);
856			must_write(path, len);
857
858			mm_send_fd(m_state.s, fd);
859			close(fd);
860			}
861			closedir(dp);
862
863			len = 0;
864			must_write(&len, sizeof len);
865			}