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mirror of https://github.com/systemd/systemd-stable.git synced 2024-12-23 17:34:00 +03:00
systemd-stable/src/libsystemd-network/sd-ipv4ll.c
2015-10-27 13:45:53 +01:00

370 lines
9.0 KiB
C

/***
This file is part of systemd.
Copyright (C) 2014 Axis Communications AB. All rights reserved.
Copyright (C) 2015 Tom Gundersen
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "sd-ipv4acd.h"
#include "sd-ipv4ll.h"
#include "alloc-util.h"
#include "event-util.h"
#include "in-addr-util.h"
#include "list.h"
#include "random-util.h"
#include "refcnt.h"
#include "siphash24.h"
#include "sparse-endian.h"
#include "util.h"
#define IPV4LL_NETWORK 0xA9FE0000L
#define IPV4LL_NETMASK 0xFFFF0000L
#define IPV4LL_DONT_DESTROY(ll) \
_cleanup_ipv4ll_unref_ _unused_ sd_ipv4ll *_dont_destroy_##ll = sd_ipv4ll_ref(ll)
struct sd_ipv4ll {
unsigned n_ref;
sd_ipv4acd *acd;
be32_t address; /* the address pushed to ACD */
struct random_data *random_data;
char *random_data_state;
/* External */
be32_t claimed_address;
sd_ipv4ll_cb_t cb;
void* userdata;
};
sd_ipv4ll *sd_ipv4ll_ref(sd_ipv4ll *ll) {
if (!ll)
return NULL;
assert(ll->n_ref >= 1);
ll->n_ref++;
return ll;
}
sd_ipv4ll *sd_ipv4ll_unref(sd_ipv4ll *ll) {
if (!ll)
return NULL;
assert(ll->n_ref >= 1);
ll->n_ref--;
if (ll->n_ref > 0)
return NULL;
sd_ipv4acd_unref(ll->acd);
free(ll->random_data);
free(ll->random_data_state);
free(ll);
return NULL;
}
DEFINE_TRIVIAL_CLEANUP_FUNC(sd_ipv4ll*, sd_ipv4ll_unref);
#define _cleanup_ipv4ll_unref_ _cleanup_(sd_ipv4ll_unrefp)
static void ipv4ll_on_acd(sd_ipv4acd *ll, int event, void *userdata);
int sd_ipv4ll_new(sd_ipv4ll **ret) {
_cleanup_ipv4ll_unref_ sd_ipv4ll *ll = NULL;
int r;
assert_return(ret, -EINVAL);
ll = new0(sd_ipv4ll, 1);
if (!ll)
return -ENOMEM;
r = sd_ipv4acd_new(&ll->acd);
if (r < 0)
return r;
r = sd_ipv4acd_set_callback(ll->acd, ipv4ll_on_acd, ll);
if (r < 0)
return r;
ll->n_ref = 1;
*ret = ll;
ll = NULL;
return 0;
}
int sd_ipv4ll_stop(sd_ipv4ll *ll) {
int r;
assert_return(ll, -EINVAL);
r = sd_ipv4acd_stop(ll->acd);
if (r < 0)
return r;
return 0;
}
int sd_ipv4ll_set_index(sd_ipv4ll *ll, int interface_index) {
assert_return(ll, -EINVAL);
return sd_ipv4acd_set_index(ll->acd, interface_index);
}
#define HASH_KEY SD_ID128_MAKE(df,04,22,98,3f,ad,14,52,f9,87,2e,d1,9c,70,e2,f2)
int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) {
int r;
assert_return(ll, -EINVAL);
if (!ll->random_data) {
uint8_t seed[8];
/* If no random data is set, generate some from the MAC */
siphash24(seed, &addr->ether_addr_octet,
ETH_ALEN, HASH_KEY.bytes);
assert_cc(sizeof(unsigned) <= 8);
r = sd_ipv4ll_set_address_seed(ll, *(unsigned*)seed);
if (r < 0)
return r;
}
return sd_ipv4acd_set_mac(ll->acd, addr);
}
int sd_ipv4ll_detach_event(sd_ipv4ll *ll) {
assert_return(ll, -EINVAL);
return sd_ipv4acd_detach_event(ll->acd);
}
int sd_ipv4ll_attach_event(sd_ipv4ll *ll, sd_event *event, int priority) {
int r;
assert_return(ll, -EINVAL);
r = sd_ipv4acd_attach_event(ll->acd, event, priority);
if (r < 0)
return r;
return 0;
}
int sd_ipv4ll_set_callback(sd_ipv4ll *ll, sd_ipv4ll_cb_t cb, void *userdata) {
assert_return(ll, -EINVAL);
ll->cb = cb;
ll->userdata = userdata;
return 0;
}
int sd_ipv4ll_get_address(sd_ipv4ll *ll, struct in_addr *address){
assert_return(ll, -EINVAL);
assert_return(address, -EINVAL);
if (ll->claimed_address == 0)
return -ENOENT;
address->s_addr = ll->claimed_address;
return 0;
}
int sd_ipv4ll_set_address_seed(sd_ipv4ll *ll, unsigned seed) {
_cleanup_free_ struct random_data *random_data = NULL;
_cleanup_free_ char *random_data_state = NULL;
int r;
assert_return(ll, -EINVAL);
random_data = new0(struct random_data, 1);
if (!random_data)
return -ENOMEM;
random_data_state = new0(char, 128);
if (!random_data_state)
return -ENOMEM;
r = initstate_r(seed, random_data_state, 128, random_data);
if (r < 0)
return r;
free(ll->random_data);
ll->random_data = random_data;
random_data = NULL;
free(ll->random_data_state);
ll->random_data_state = random_data_state;
random_data_state = NULL;
return 0;
}
int sd_ipv4ll_is_running(sd_ipv4ll *ll) {
assert_return(ll, false);
return sd_ipv4acd_is_running(ll->acd);
}
static bool ipv4ll_address_is_valid(const struct in_addr *address) {
uint32_t addr;
assert(address);
if (!in_addr_is_link_local(AF_INET, (const union in_addr_union *) address))
return false;
addr = be32toh(address->s_addr);
if ((addr & 0x0000FF00) == 0x0000 ||
(addr & 0x0000FF00) == 0xFF00)
return false;
return true;
}
int sd_ipv4ll_set_address(sd_ipv4ll *ll, const struct in_addr *address) {
int r;
assert_return(ll, -EINVAL);
assert_return(address, -EINVAL);
assert_return(ipv4ll_address_is_valid(address), -EINVAL);
r = sd_ipv4acd_set_address(ll->acd, address);
if (r < 0)
return r;
ll->address = address->s_addr;
return 0;
}
static int ipv4ll_pick_address(sd_ipv4ll *ll) {
struct in_addr in_addr;
be32_t addr;
int r;
int32_t random;
assert(ll);
assert(ll->random_data);
do {
r = random_r(ll->random_data, &random);
if (r < 0)
return r;
addr = htonl((random & 0x0000FFFF) | IPV4LL_NETWORK);
} while (addr == ll->address ||
(ntohl(addr) & 0x0000FF00) == 0x0000 ||
(ntohl(addr) & 0x0000FF00) == 0xFF00);
in_addr.s_addr = addr;
r = sd_ipv4ll_set_address(ll, &in_addr);
if (r < 0)
return r;
return 0;
}
int sd_ipv4ll_start(sd_ipv4ll *ll) {
int r;
assert_return(ll, -EINVAL);
assert_return(ll->random_data, -EINVAL);
if (ll->address == 0) {
r = ipv4ll_pick_address(ll);
if (r < 0)
return r;
}
r = sd_ipv4acd_start(ll->acd);
if (r < 0)
return r;
return 0;
}
static void ipv4ll_client_notify(sd_ipv4ll *ll, int event) {
assert(ll);
if (ll->cb)
ll->cb(ll, event, ll->userdata);
}
void ipv4ll_on_acd(sd_ipv4acd *acd, int event, void *userdata) {
sd_ipv4ll *ll = userdata;
IPV4LL_DONT_DESTROY(ll);
int r;
assert(acd);
assert(ll);
switch (event) {
case SD_IPV4ACD_EVENT_STOP:
ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_STOP);
ll->claimed_address = 0;
break;
case SD_IPV4ACD_EVENT_BIND:
ll->claimed_address = ll->address;
ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_BIND);
break;
case SD_IPV4ACD_EVENT_CONFLICT:
/* if an address was already bound we must call up to the
user to handle this, otherwise we just try again */
if (ll->claimed_address != 0) {
ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_CONFLICT);
ll->claimed_address = 0;
} else {
r = ipv4ll_pick_address(ll);
if (r < 0)
goto error;
r = sd_ipv4acd_start(ll->acd);
if (r < 0)
goto error;
}
break;
default:
assert_not_reached("Invalid IPv4ACD event.");
}
return;
error:
ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_STOP);
}