freebsd-nq/lib/libifconfig/libifconfig_carp.c
Kristof Provost 137818006d carp: support unicast
Allow users to configure the address to send carp messages to. This
allows carp to be used in unicast mode, which is useful in certain
virtual configurations (e.g. AWS, VMWare ESXi, ...)

Reviewed by:	melifaro
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D38940
2023-03-20 14:37:09 +01:00

227 lines
6.3 KiB
C

/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/ip_carp.h>
#include <netinet/ip_carp_nl.h>
#include <netlink/netlink.h>
#include <netlink/netlink_generic.h>
#include <netlink/netlink_snl.h>
#include <netlink/netlink_snl_generic.h>
#include <netlink/netlink_snl_route.h>
#include <string.h>
#include <strings.h>
#include "libifconfig.h"
#include "libifconfig_internal.h"
#include <stdio.h>
#define _OUT(_field) offsetof(struct ifconfig_carp, _field)
static struct snl_attr_parser ap_carp_get[] = {
{ .type = CARP_NL_VHID, .off = _OUT(carpr_vhid), .cb = snl_attr_get_uint32 },
{ .type = CARP_NL_STATE, .off = _OUT(carpr_state), .cb = snl_attr_get_uint32 },
{ .type = CARP_NL_ADVBASE, .off = _OUT(carpr_advbase), .cb = snl_attr_get_int32 },
{ .type = CARP_NL_ADVSKEW, .off = _OUT(carpr_advskew), .cb = snl_attr_get_int32 },
{ .type = CARP_NL_KEY, .off = _OUT(carpr_key), .cb = snl_attr_get_string },
{ .type = CARP_NL_ADDR, .off = _OUT(carpr_addr), .cb = snl_attr_get_in_addr },
{ .type = CARP_NL_ADDR6, .off = _OUT(carpr_addr6), .cb = snl_attr_get_in6_addr },
};
#undef _OUT
SNL_DECLARE_GENL_PARSER(carp_get_parser, ap_carp_get);
static int
_ifconfig_carp_get(ifconfig_handle_t *h, const char *name,
struct ifconfig_carp *carp, size_t ncarp, uint32_t vhid)
{
struct snl_state ss = {};
struct snl_errmsg_data e = {};
struct snl_writer nw;
struct nlmsghdr *hdr;
size_t i = 0;
uint32_t seq_id;
unsigned int ifindex;
int family_id;
ifconfig_error_clear(h);
ifindex = if_nametoindex(name);
if (ifindex == 0) {
ifconfig_error(h, NETLINK, ENOENT);
return (-1);
}
if (! snl_init(&ss, NETLINK_GENERIC)) {
ifconfig_error(h, NETLINK, ENOTSUP);
return (-1);
}
snl_init_writer(&ss, &nw);
family_id = snl_get_genl_family(&ss, CARP_NL_FAMILY_NAME);
if (family_id == 0) {
ifconfig_error(h, NETLINK, EPROTONOSUPPORT);
goto out;
}
hdr = snl_create_genl_msg_request(&nw, family_id, CARP_NL_CMD_GET);
hdr->nlmsg_flags |= NLM_F_DUMP;
snl_add_msg_attr_u32(&nw, CARP_NL_IFINDEX, ifindex);
if (vhid != 0)
snl_add_msg_attr_u32(&nw, CARP_NL_VHID, vhid);
hdr = snl_finalize_msg(&nw);
if (hdr == NULL) {
ifconfig_error(h, NETLINK, ENOMEM);
goto out;
}
seq_id = hdr->nlmsg_seq;
if (! snl_send_message(&ss, hdr)) {
ifconfig_error(h, NETLINK, EIO);
goto out;
}
while ((hdr = snl_read_reply_multi(&ss, seq_id, &e)) != NULL) {
if (e.error != 0) {
ifconfig_error(h, NETLINK, e.error);
break;
}
if (i >= ncarp) {
ifconfig_error(h, NETLINK, E2BIG);
break;
}
memset(&carp[i], 0, sizeof(carp[0]));
if (! snl_parse_nlmsg(&ss, hdr, &carp_get_parser, &carp[i]))
continue;
i++;
carp[0].carpr_count = i;
if (i > ncarp) {
ifconfig_error(h, NETLINK, E2BIG);
break;
}
}
out:
snl_free(&ss);
return (h->error.errcode ? -1 : 0);
}
int
ifconfig_carp_set_info(ifconfig_handle_t *h, const char *name,
const struct ifconfig_carp *carpr)
{
struct snl_state ss = {};
struct snl_writer nw;
struct nlmsghdr *hdr;
unsigned int ifindex;
int family_id;
uint32_t seq_id;
ifconfig_error_clear(h);
ifindex = if_nametoindex(name);
if (ifindex == 0) {
ifconfig_error(h, NETLINK, ENOENT);
return (-1);
}
if (! snl_init(&ss, NETLINK_GENERIC)) {
ifconfig_error(h, NETLINK, ENOTSUP);
return (-1);
}
snl_init_writer(&ss, &nw);
family_id = snl_get_genl_family(&ss, CARP_NL_FAMILY_NAME);
if (family_id == 0) {
ifconfig_error(h, NETLINK, EPROTONOSUPPORT);
return (-1);
}
hdr = snl_create_genl_msg_request(&nw, family_id, CARP_NL_CMD_SET);
snl_add_msg_attr_u32(&nw, CARP_NL_VHID, carpr->carpr_vhid);
snl_add_msg_attr_u32(&nw, CARP_NL_STATE, carpr->carpr_state);
snl_add_msg_attr_s32(&nw, CARP_NL_ADVBASE, carpr->carpr_advbase);
snl_add_msg_attr_s32(&nw, CARP_NL_ADVSKEW, carpr->carpr_advskew);
snl_add_msg_attr_u32(&nw, CARP_NL_IFINDEX, ifindex);
snl_add_msg_attr(&nw, CARP_NL_ADDR, sizeof(carpr->carpr_addr),
&carpr->carpr_addr);
snl_add_msg_attr(&nw, CARP_NL_ADDR6, sizeof(carpr->carpr_addr6),
&carpr->carpr_addr6);
hdr = snl_finalize_msg(&nw);
if (hdr == NULL) {
ifconfig_error(h, NETLINK, ENOMEM);
goto out;
}
seq_id = hdr->nlmsg_seq;
if (! snl_send_message(&ss, hdr)) {
ifconfig_error(h, NETLINK, EIO);
goto out;
}
struct snl_errmsg_data e = { };
if (! snl_read_reply_code(&ss, seq_id, &e))
ifconfig_error(h, NETLINK, e.error);
out:
snl_free(&ss);
return (h->error.errcode ? -1 : 0);
}
int
ifconfig_carp_get_vhid(ifconfig_handle_t *h, const char *name,
struct ifconfig_carp *carp, uint32_t vhid)
{
return (_ifconfig_carp_get(h, name, carp, 1, vhid));
}
int
ifconfig_carp_get_info(ifconfig_handle_t *h, const char *name,
struct ifconfig_carp *carp, size_t ncarp)
{
return (_ifconfig_carp_get(h, name, carp, ncarp, 0));
}