/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright (C) 2014 Intel Corporation. All rights reserved.
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 .
***/
#include
#include
#include
#include "sparse-endian.h"
#include "util.h"
#include "dhcp6-internal.h"
#include "dhcp6-protocol.h"
#define DHCP6_OPTION_HDR_LEN 4
#define DHCP6_OPTION_IA_NA_LEN 12
#define DHCP6_OPTION_IA_TA_LEN 4
#define DHCP6_OPTION_IAADDR_LEN 24
static int option_append_hdr(uint8_t **buf, size_t *buflen, uint16_t optcode,
size_t optlen) {
assert_return(buf, -EINVAL);
assert_return(*buf, -EINVAL);
assert_return(buflen, -EINVAL);
if (optlen > 0xffff || *buflen < optlen + DHCP6_OPTION_HDR_LEN)
return -ENOBUFS;
(*buf)[0] = optcode >> 8;
(*buf)[1] = optcode & 0xff;
(*buf)[2] = optlen >> 8;
(*buf)[3] = optlen & 0xff;
*buf += DHCP6_OPTION_HDR_LEN;
*buflen -= DHCP6_OPTION_HDR_LEN;
return 0;
}
int dhcp6_option_append(uint8_t **buf, size_t *buflen, uint16_t code,
size_t optlen, const void *optval) {
int r;
assert_return(optval || optlen == 0, -EINVAL);
r = option_append_hdr(buf, buflen, code, optlen);
if (r < 0)
return r;
if (optval)
memcpy(*buf, optval, optlen);
*buf += optlen;
*buflen -= optlen;
return 0;
}
int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, DHCP6IA *ia) {
uint16_t len;
uint8_t *ia_hdr;
size_t ia_buflen, ia_addrlen = 0;
DHCP6Address *addr;
int r;
assert_return(buf && *buf && buflen && ia, -EINVAL);
switch (ia->type) {
case DHCP6_OPTION_IA_NA:
len = DHCP6_OPTION_IA_NA_LEN;
break;
case DHCP6_OPTION_IA_TA:
len = DHCP6_OPTION_IA_TA_LEN;
break;
default:
return -EINVAL;
}
if (*buflen < len)
return -ENOBUFS;
ia_hdr = *buf;
ia_buflen = *buflen;
*buf += DHCP6_OPTION_HDR_LEN;
*buflen -= DHCP6_OPTION_HDR_LEN;
memcpy(*buf, &ia->id, len);
*buf += len;
*buflen -= len;
LIST_FOREACH(addresses, addr, ia->addresses) {
r = option_append_hdr(buf, buflen, DHCP6_OPTION_IAADDR,
DHCP6_OPTION_IAADDR_LEN);
if (r < 0)
return r;
memcpy(*buf, &addr->address, DHCP6_OPTION_IAADDR_LEN);
*buf += DHCP6_OPTION_IAADDR_LEN;
*buflen -= DHCP6_OPTION_IAADDR_LEN;
ia_addrlen += DHCP6_OPTION_HDR_LEN + DHCP6_OPTION_IAADDR_LEN;
}
r = option_append_hdr(&ia_hdr, &ia_buflen, ia->type, len + ia_addrlen);
if (r < 0)
return r;
return 0;
}
static int option_parse_hdr(uint8_t **buf, size_t *buflen, uint16_t *opt,
size_t *optlen) {
uint16_t len;
assert_return(buf, -EINVAL);
assert_return(opt, -EINVAL);
assert_return(optlen, -EINVAL);
if (*buflen < 4)
return -ENOMSG;
len = (*buf)[2] << 8 | (*buf)[3];
if (len > *buflen)
return -ENOMSG;
*opt = (*buf)[0] << 8 | (*buf)[1];
*optlen = len;
*buf += 4;
*buflen -= 4;
return 0;
}
int dhcp6_option_parse(uint8_t **buf, size_t *buflen, uint16_t *optcode,
size_t *optlen, uint8_t **optvalue) {
int r;
assert_return(buf && buflen && optcode && optlen && optvalue, -EINVAL);
r = option_parse_hdr(buf, buflen, optcode, optlen);
if (r < 0)
return r;
if (*optlen > *buflen)
return -ENOBUFS;
*optvalue = *buf;
*buflen -= *optlen;
*buf += *optlen;
return 0;
}
int dhcp6_option_parse_ia(uint8_t **buf, size_t *buflen, uint16_t iatype,
DHCP6IA *ia) {
int r;
uint16_t opt, status;
size_t optlen;
size_t iaaddr_offset;
DHCP6Address *addr;
uint32_t lt_t1, lt_t2, lt_valid, lt_pref, lt_min = ~0;
assert_return(ia, -EINVAL);
assert_return(!ia->addresses, -EINVAL);
switch (iatype) {
case DHCP6_OPTION_IA_NA:
if (*buflen < DHCP6_OPTION_IA_NA_LEN + DHCP6_OPTION_HDR_LEN +
DHCP6_OPTION_IAADDR_LEN) {
r = -ENOBUFS;
goto error;
}
iaaddr_offset = DHCP6_OPTION_IA_NA_LEN;
memcpy(&ia->id, *buf, iaaddr_offset);
lt_t1 = be32toh(ia->lifetime_t1);
lt_t2 = be32toh(ia->lifetime_t2);
if (lt_t1 && lt_t2 && lt_t1 > lt_t2) {
log_dhcp6_client(client, "IA T1 %ds > T2 %ds",
lt_t1, lt_t2);
r = -EINVAL;
goto error;
}
break;
case DHCP6_OPTION_IA_TA:
if (*buflen < DHCP6_OPTION_IA_TA_LEN + DHCP6_OPTION_HDR_LEN +
DHCP6_OPTION_IAADDR_LEN) {
r = -ENOBUFS;
goto error;
}
iaaddr_offset = DHCP6_OPTION_IA_TA_LEN;
memcpy(&ia->id, *buf, iaaddr_offset);
ia->lifetime_t1 = 0;
ia->lifetime_t2 = 0;
break;
default:
r = -ENOMSG;
goto error;
}
ia->type = iatype;
*buflen -= iaaddr_offset;
*buf += iaaddr_offset;
while ((r = option_parse_hdr(buf, buflen, &opt, &optlen)) >= 0) {
switch (opt) {
case DHCP6_OPTION_IAADDR:
addr = new0(DHCP6Address, 1);
if (!addr) {
r = -ENOMEM;
goto error;
}
LIST_INIT(addresses, addr);
memcpy(&addr->address, *buf, DHCP6_OPTION_IAADDR_LEN);
lt_valid = be32toh(addr->lifetime_valid);
lt_pref = be32toh(addr->lifetime_valid);
if (!lt_valid || lt_pref > lt_valid) {
log_dhcp6_client(client, "IA preferred %ds > valid %ds",
lt_pref, lt_valid);
free(addr);
} else {
LIST_PREPEND(addresses, ia->addresses, addr);
if (lt_valid < lt_min)
lt_min = lt_valid;
}
break;
case DHCP6_OPTION_STATUS_CODE:
if (optlen < sizeof(status))
break;
status = (*buf)[0] << 8 | (*buf)[1];
if (status) {
log_dhcp6_client(client, "IA status %d",
status);
r = -EINVAL;
goto error;
}
break;
default:
log_dhcp6_client(client, "Unknown IA option %d", opt);
break;
}
*buflen -= optlen;
*buf += optlen;
}
if (r == -ENOMSG)
r = 0;
if (!ia->lifetime_t1 && !ia->lifetime_t2) {
lt_t1 = lt_min / 2;
lt_t2 = lt_min / 10 * 8;
ia->lifetime_t1 = htobe32(lt_t1);
ia->lifetime_t2 = htobe32(lt_t2);
log_dhcp6_client(client, "Computed IA T1 %ds and T2 %ds as both were zero",
lt_t1, lt_t2);
}
if (*buflen)
r = -ENOMSG;
error:
*buf += *buflen;
*buflen = 0;
return r;
}