/* SPDX-License-Identifier: BSD-2-Clause */
/*
* Privilege Separation for dhcpcd, Linux driver
* Copyright (c) 2006-2020 Roy Marples <roy@marples.name>
* 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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/ioctl.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "if.h"
#include "logerr.h"
#include "privsep.h"
static ssize_t
ps_root_dosendnetlink(int protocol, struct msghdr *msg)
{
struct sockaddr_nl snl = { .nl_family = AF_NETLINK };
int s;
unsigned char buf[16 * 1024];
struct iovec riov = {
.iov_base = buf,
.iov_len = sizeof(buf),
};
ssize_t retval;
if ((s = if_linksocket(&snl, protocol)) == -1)
return -1;
if (sendmsg(s, msg, 0) == -1) {
retval = -1;
goto out;
}
retval = if_getnetlink(NULL, &riov, s, 0, NULL, NULL);
out:
close(s);
return retval;
}
static ssize_t
ps_root_dowritepathuint(const void *data, size_t len)
{
const char *path = data;
size_t plen;
unsigned int val;
int fd;
ssize_t r;
if (len < sizeof(plen)) {
errno = EINVAL;
return -1;
}
memcpy(&plen, path, sizeof(plen));
path += sizeof(plen);
if (sizeof(plen) + plen + sizeof(val) > len) {
errno = EINVAL;
return -1;
}
memcpy(&val, path + plen, sizeof(val));
fd = open(path, O_WRONLY);
if (fd == -1)
return -1;
r = dprintf(fd, "%u", val);
close(fd);
return r;
}
ssize_t
ps_root_os(struct ps_msghdr *psm, struct msghdr *msg)
{
struct iovec *iov = msg->msg_iov;
void *data = iov->iov_base;
size_t len = iov->iov_len;
switch (psm->ps_cmd) {
case PS_ROUTE:
return ps_root_dosendnetlink((int)psm->ps_flags, msg);
case PS_WRITEPATHUINT:
return ps_root_dowritepathuint(data, len);
default:
errno = ENOTSUP;
return -1;
}
}
ssize_t
ps_root_sendnetlink(struct dhcpcd_ctx *ctx, int protocol, struct msghdr *msg)
{
if (ps_sendmsg(ctx, ctx->ps_root_fd, PS_ROUTE,
(unsigned long)protocol, msg) == -1)
return -1;
return ps_root_readerror(ctx, NULL, 0);
}
ssize_t
ps_root_writepathuint(struct dhcpcd_ctx *ctx, const char *path,
unsigned int val)
{
char buf[PS_BUFLEN], *p = buf;
size_t plen = strlen(path) + 1;
size_t len = sizeof(plen) + plen + sizeof(val);
if (len > sizeof(buf)) {
errno = ENOBUFS;
return -1;
}
memcpy(p, &plen, sizeof(plen));
p += sizeof(plen);
memcpy(p, path, plen);
p += plen;
memcpy(p, &val, sizeof(val));
if (ps_sendcmd(ctx, ctx->ps_root_fd, PS_WRITEPATHUINT,
0, buf, len) == -1)
return -1;
return ps_root_readerror(ctx, NULL, 0);
}
