NetBSD/sys/net/link_proto.c

238 lines
6.5 KiB
C

/* $NetBSD: link_proto.c,v 1.3 2007/08/30 02:17:35 dyoung Exp $ */
/*-
* Copyright (c) 1982, 1986, 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.
*
* @(#)uipc_proto.c 8.2 (Berkeley) 2/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: link_proto.c,v 1.3 2007/08/30 02:17:35 dyoung Exp $");
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/domain.h>
#include <sys/mbuf.h>
#include <sys/un.h>
#include <sys/socketvar.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/raw_cb.h>
static int sockaddr_dl_cmp(const struct sockaddr *, const struct sockaddr *);
/*
* Definitions of protocols supported in the link-layer domain.
*/
DOMAIN_DEFINE(linkdomain); /* forward define and add to link set */
struct domain linkdomain = {
.dom_family = AF_LINK,
.dom_name = "link",
.dom_externalize = NULL,
.dom_dispose = NULL,
.dom_protosw = NULL,
.dom_protoswNPROTOSW = NULL,
.dom_sockaddr_cmp = sockaddr_dl_cmp
};
/* Compare the field at byte offsets [fieldstart, fieldend) in
* two memory regions, [l, l + llen) and [r, r + llen).
*/
static inline int
submemcmp(const void *l, const void *r,
const uint_fast8_t llen, const uint_fast8_t rlen,
const uint_fast8_t fieldstart, const uint_fast8_t fieldend)
{
uint_fast8_t cmpend, minlen;
const uint8_t *lb = l, *rb = r;
int rc;
minlen = MIN(llen, rlen);
/* The field is missing from one region. The shorter region is the
* lesser region.
*/
if (fieldstart >= minlen)
return llen - rlen;
/* Two empty, present fields are always equal. */
if (fieldstart > fieldend)
return 0;
cmpend = MIN(fieldend, minlen);
rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart);
if (rc != 0)
return rc;
/* If one or both fields are truncated, then the shorter is the lesser
* field.
*/
if (minlen < fieldend)
return llen - rlen;
/* Fields are full-length and equal. The fields are equal. */
return 0;
}
uint8_t
sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen)
{
return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]);
}
struct sockaddr *
sockaddr_dl_alloc(uint16_t ifindex, uint8_t type,
const void *name, uint8_t namelen, const void *addr, uint8_t addrlen,
int flags)
{
struct sockaddr *sa;
socklen_t len;
len = sockaddr_dl_measure(namelen, addrlen);
sa = sockaddr_alloc(AF_LINK, len, flags);
if (sa == NULL)
return NULL;
if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen,
addr, addrlen) == NULL) {
sockaddr_free(sa);
return NULL;
}
return sa;
}
struct sockaddr_dl *
sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex,
uint8_t type, const void *name, uint8_t namelen, const void *addr,
uint8_t addrlen)
{
socklen_t len;
sdl->sdl_family = AF_LINK;
sdl->sdl_slen = 0;
len = sockaddr_dl_measure(namelen, addrlen);
if (len > socklen) {
sdl->sdl_len = socklen;
#ifdef DIAGNOSTIC
printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
socklen);
#endif
return NULL;
}
sdl->sdl_len = len;
sdl->sdl_index = ifindex;
sdl->sdl_type = type;
memset(&sdl->sdl_data[0], 0, namelen + addrlen);
if (name != NULL) {
memcpy(&sdl->sdl_data[0], name, namelen);
sdl->sdl_nlen = namelen;
} else
sdl->sdl_nlen = 0;
if (addr != NULL) {
memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
sdl->sdl_alen = addrlen;
} else
sdl->sdl_alen = 0;
return sdl;
}
static int
sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
{
int rc;
const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index);
const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen);
uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]);
const struct sockaddr_dl *sdl1, *sdl2;
sdl1 = satocsdl(sa1);
sdl2 = satocsdl(sa2);
rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
indexofs, nlenofs);
if (rc != 0)
return rc;
rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen));
if (rc != 0)
return rc;
if (sdl1->sdl_nlen != sdl2->sdl_nlen)
return sdl1->sdl_nlen - sdl2->sdl_nlen;
dataofs += sdl1->sdl_nlen;
rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen));
if (rc != 0)
return rc;
if (sdl1->sdl_alen != sdl2->sdl_alen)
return sdl1->sdl_alen - sdl2->sdl_alen;
dataofs += sdl1->sdl_alen;
rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen));
if (sdl1->sdl_slen != sdl2->sdl_slen)
return sdl1->sdl_slen - sdl2->sdl_slen;
return sdl1->sdl_len - sdl2->sdl_len;
}
struct sockaddr_dl *
sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen,
const void *addr, uint8_t addrlen)
{
socklen_t len;
len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen);
if (len > socklen) {
#ifdef DIAGNOSTIC
printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
socklen);
#endif
return NULL;
}
memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
sdl->sdl_alen = addrlen;
sdl->sdl_len = len;
return sdl;
}