/* $NetBSD: if_media.c,v 1.54 2022/09/03 02:47:59 thorpej Exp $ */
/*-
* Copyright (c) 1998, 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1997
* Jonathan Stone and Jason R. Thorpe. All rights reserved.
*
* This software is derived from information provided by Matt Thomas.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Jonathan Stone
* and Jason R. Thorpe for the NetBSD Project.
* 4. The names of the authors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 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.
*/
/*
* BSD/OS-compatible network interface media selection.
*
* Where it is safe to do so, this code strays slightly from the BSD/OS
* design. Software which uses the API (device drivers, basically)
* shouldn't notice any difference.
*
* Many thanks to Matt Thomas for providing the information necessary
* to implement this interface.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_media.c,v 1.54 2022/09/03 02:47:59 thorpej Exp $");
#define __IFMEDIA_PRIVATE
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/kmem.h>
#include <net/if.h>
#include <net/if_media.h>
static void ifmedia_status(struct ifmedia *, struct ifnet *,
struct ifmediareq *);
static struct ifmedia_entry *
ifmedia_match_locked(struct ifmedia *, u_int, u_int);
/*
* Compile-time options:
* IFMEDIA_DEBUG:
* Turn on implementation-level debug printfs.
* Useful for debugging newly-ported drivers.
*/
#ifdef IFMEDIA_DEBUG
int ifmedia_debug = 0;
static void ifmedia_printword(int);
#endif
/*
* We need to implement a recursive mutex to handle the un-converted
* driver case. For a fully MP-safe driver, the media lock will be
* held before calling any of the entry points that require it. However,
* this is not necessarily the case for a driver that hasn't yet been
* converted, and the entry point calls may be nested (for example
* mii_ifmedia_change -> ether_mediachange -> mii_mediachg). Luckily,
* the nesting won't be very deep, and 4 nested holds should be plenty.
*/
#define IFM_L_OWNLOCK 0x01
#define IFM_L_COUNT_MASK 0x3UL
#define IFM_L_CPU_MASK ~(IFM_L_COUNT_MASK)
void
ifmedia_lock_for_legacy(struct ifmedia *ifm)
{
uintptr_t cnt = IFM_L_OWNLOCK;
uintptr_t ci;
if (mutex_tryenter(ifm->ifm_lock)) {
goto gotit;
}
kpreempt_disable();
ci = (uintptr_t)curcpu();
if ((ifm->ifm_legacy & IFM_L_CPU_MASK) == ci) {
cnt = ifm->ifm_legacy & IFM_L_COUNT_MASK;
KASSERT(cnt < IFM_L_COUNT_MASK);
cnt++;
kpreempt_enable();
goto gotit;
}
kpreempt_enable();
mutex_enter(ifm->ifm_lock);
gotit:
KASSERT(kpreempt_disabled());
ci = (uintptr_t)curcpu();
KASSERT((ci & IFM_L_CPU_MASK) == ci);
ifm->ifm_legacy = ci | cnt;
}
void
ifmedia_unlock_for_legacy(struct ifmedia *ifm)
{
uintptr_t cnt;
uintptr_t ci = (uintptr_t)curcpu();
KASSERT(kpreempt_disabled());
KASSERT((ifm->ifm_legacy & IFM_L_CPU_MASK) == ci);
cnt = ifm->ifm_legacy & IFM_L_COUNT_MASK;
KASSERT(cnt != 0);
if (cnt == IFM_L_OWNLOCK) {
ifm->ifm_legacy = IFM_L_OWNLOCK;
mutex_exit(ifm->ifm_lock);
return;
}
cnt--;
ifm->ifm_legacy = ci | cnt;
}
/*
* Initialize if_media struct for a specific interface instance.
*/
void
ifmedia_init_with_lock(struct ifmedia *ifm, int dontcare_mask,
ifm_change_cb_t change_callback, ifm_stat_cb_t status_callback,
kmutex_t *lock)
{
/*
* XXX Would really like to assert:
*
* !if_is_mpsafe(ifp) || ((if_is_mpsafe(ifp) && lock != NULL)
*
* ...but we don't have access to the ifnet here.
*/
TAILQ_INIT(&ifm->ifm_list);
ifm->ifm_cur = NULL;
ifm->ifm_media = IFM_NONE;
ifm->ifm_mask = dontcare_mask; /* IF don't-care bits */
ifm->ifm_change = change_callback;
ifm->ifm_status = status_callback;
ifm->ifm_legacy = 0;
if (lock == NULL) {
/*
* This is to support drivers that are not yet MP-safe
* with regard to the ifmedia layer. In these cases,
* we supply the lock and we ensure it's taken upon entry
* to various routines that expect it to be held. When
* we do this, we expect that the driver is in general a
* non-MP-safe driver and has already gone to splnet().
*/
lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NET);
ifm->ifm_legacy = IFM_L_OWNLOCK;
}
ifm->ifm_lock = lock;
}
void
ifmedia_init(struct ifmedia *ifm, int dontcare_mask,
ifm_change_cb_t change_callback, ifm_stat_cb_t status_callback)
{
ifmedia_init_with_lock(ifm, dontcare_mask, change_callback,
status_callback, NULL);
}
/*
* Free resources associated with an ifmedia.
*/
void
ifmedia_fini(struct ifmedia *ifm)
{
ifmedia_removeall(ifm);
if (ifm->ifm_legacy) {
KASSERT(ifm->ifm_legacy == IFM_L_OWNLOCK);
mutex_obj_free(ifm->ifm_lock);
}
ifm->ifm_legacy = 0;
ifm->ifm_lock = NULL;
}
int
ifmedia_change(struct ifmedia *ifm, struct ifnet *ifp)
{
int rv;
IFMEDIA_LOCK_FOR_LEGACY(ifm);
KASSERT(ifmedia_locked(ifm));
if (ifm->ifm_change)
rv = (*ifm->ifm_change)(ifp);
else
rv = -1;
IFMEDIA_UNLOCK_FOR_LEGACY(ifm);
return rv;
}
static void
ifmedia_status(struct ifmedia *ifm, struct ifnet *ifp, struct ifmediareq *ifmr)
{
KASSERT(ifmedia_locked(ifm));
if (ifm->ifm_status == NULL)
return;
(*ifm->ifm_status)(ifp, ifmr);
}
/*
* Add a media configuration to the list of supported media
* for a specific interface instance.
*/
static void
ifmedia_add_entry(struct ifmedia *ifm, int mword, int data, void *aux,
struct ifmedia_entry *entry)
{
#ifdef IFMEDIA_DEBUG
if (ifmedia_debug) {
if (ifm == NULL) {
printf("ifmedia_add: null ifm\n");
return;
}
printf("Adding entry for ");
ifmedia_printword(mword);
}
#endif
entry->ifm_media = mword;
entry->ifm_data = data;
entry->ifm_aux = aux;
TAILQ_INSERT_TAIL(&ifm->ifm_list, entry, ifm_list);
}
void
ifmedia_add(struct ifmedia *ifm, int mword, int data, void *aux)
{
struct ifmedia_entry *entry;
entry = kmem_zalloc(sizeof(*entry), KM_SLEEP);
ifmedia_lock(ifm);
ifmedia_add_entry(ifm, mword, data, aux, entry);
ifmedia_unlock(ifm);
}
/*
* Add an array of media configurations to the list of
* supported media for a specific interface instance.
*/
void
ifmedia_list_add(struct ifmedia *ifm, struct ifmedia_entry *lp, int count)
{
int i;
for (i = 0; i < count; i++)
ifmedia_add(ifm, lp[i].ifm_media, lp[i].ifm_data,
lp[i].ifm_aux);
}
/*
* Set the default active media.
*
* Called by device-specific code which is assumed to have already
* selected the default media in hardware. We do _not_ call the
* media-change callback.
*/
void
ifmedia_set(struct ifmedia *ifm, int target)
{
struct ifmedia_entry *match, *entry = NULL;
ifmedia_lock(ifm);
match = ifmedia_match_locked(ifm, target, ifm->ifm_mask);
/*
* If we didn't find the requested media, then we try to fall
* back to target-type (IFM_ETHER, e.g.) | IFM_NONE. If that's
* not on the list, then we add it and set the media to it.
*
* Since ifmedia_set is almost always called with IFM_AUTO or
* with a known-good media, this really should only occur if we:
*
* a) didn't find any PHYs, or
* b) didn't find an autoselect option on the PHY when the
* parent ethernet driver expected to.
*
* In either case, it makes sense to select no media.
*/
if (match == NULL) {
printf("ifmedia_set: no match for 0x%x/0x%x\n",
target, ~ifm->ifm_mask);
target = (target & IFM_NMASK) | IFM_NONE;
match = ifmedia_match_locked(ifm, target, ifm->ifm_mask);
if (match == NULL) {
ifmedia_unlock(ifm);
entry = kmem_zalloc(sizeof(*entry), KM_SLEEP);
ifmedia_lock(ifm);
match = ifmedia_match_locked(ifm, target,
ifm->ifm_mask);
if (match == NULL) {
ifmedia_add_entry(ifm, target, 0, NULL, entry);
entry = NULL;
}
match = ifmedia_match_locked(ifm, target,
ifm->ifm_mask);
if (match == NULL)
panic("ifmedia_set failed");
}
}
ifm->ifm_cur = match;
ifmedia_unlock(ifm);
if (entry)
kmem_free(entry, sizeof(*entry));
#ifdef IFMEDIA_DEBUG
if (ifmedia_debug) {
printf("ifmedia_set: target ");
ifmedia_printword(target);
printf("ifmedia_set: setting to ");
ifmedia_printword(ifm->ifm_cur->ifm_media);
}
#endif
}
static int
ifmedia_getwords(struct ifmedia * const ifm, int *words, int maxwords)
{
struct ifmedia_entry *ep;
int nwords = 0;
KASSERT(ifmedia_locked(ifm));
TAILQ_FOREACH(ep, &ifm->ifm_list, ifm_list) {
if (words != NULL && nwords < maxwords) {
words[nwords] = ep->ifm_media;
}
nwords++;
}
return nwords;
}
#define IFMEDIA_IOCTL_LOCK(ifm) \
do { \
if (ifmedia_islegacy(ifm)) \
ifmedia_lock_for_legacy(ifm); \
else \
ifmedia_lock(ifm); \
} while (/*CONSTCOND*/0)
#define IFMEDIA_IOCTL_UNLOCK(ifm) \
do { \
if (ifmedia_islegacy(ifm)) \
ifmedia_unlock_for_legacy(ifm); \
else \
ifmedia_unlock(ifm); \
} while (/*CONSTCOND*/0)
/*
* Device-independent media ioctl support function.
*/
int
ifmedia_ioctl(struct ifnet *ifp, struct ifreq *ifr, struct ifmedia *ifm,
u_long cmd)
{
struct ifmedia_entry *match;
struct ifmediareq *ifmr = (struct ifmediareq *)ifr;
int error = 0;
if (ifp == NULL || ifr == NULL || ifm == NULL)
return EINVAL;
KERNEL_LOCK_UNLESS_IFP_MPSAFE(ifp);
switch (cmd) {
case SIOCSIFMEDIA: /* Set the current media. */
{
struct ifmedia_entry *oldentry;
u_int oldmedia;
u_int newmedia = ifr->ifr_media;
IFMEDIA_IOCTL_LOCK(ifm);
match = ifmedia_match_locked(ifm, newmedia, ifm->ifm_mask);
if (match == NULL) {
#ifdef IFMEDIA_DEBUG
if (ifmedia_debug) {
printf("ifmedia_ioctl: no media found for "
"0x%08x\n", newmedia);
}
#endif
IFMEDIA_IOCTL_UNLOCK(ifm);
error = EINVAL;
break;
}
/*
* If no change, we're done.
* XXX Automedia may involve software intervention.
* Keep going in case the connected media changed.
* Similarly, if best match changed (kernel debugger?).
*/
if ((IFM_SUBTYPE(newmedia) != IFM_AUTO) &&
(newmedia == ifm->ifm_media) && (match == ifm->ifm_cur)) {
IFMEDIA_IOCTL_UNLOCK(ifm);
break;
}
/*
* We found a match, now make the driver switch to it.
* Make sure to preserve our old media type in case the
* driver can't switch.
*/
#ifdef IFMEDIA_DEBUG
if (ifmedia_debug) {
printf("ifmedia_ioctl: switching %s to ",
ifp->if_xname);
ifmedia_printword(match->ifm_media);
}
#endif
oldentry = ifm->ifm_cur;
oldmedia = ifm->ifm_media;
ifm->ifm_cur = match;
ifm->ifm_media = newmedia;
error = ifmedia_change(ifm, ifp);
if (error) {
ifm->ifm_cur = oldentry;
ifm->ifm_media = oldmedia;
}
IFMEDIA_IOCTL_UNLOCK(ifm);
break;
}
/* Get list of available media and current media on interface. */
case SIOCGIFMEDIA:
{
int nwords1, nwords2;
if (ifmr->ifm_count < 0) {
error = EINVAL;
break;
}
IFMEDIA_IOCTL_LOCK(ifm);
ifmr->ifm_active = ifmr->ifm_current = ifm->ifm_cur ?
ifm->ifm_cur->ifm_media : IFM_NONE;
ifmr->ifm_mask = ifm->ifm_mask;
ifmr->ifm_status = 0;
ifmedia_status(ifm, ifp, ifmr);
/*
* Count them so we know how much is the max we'll
* need.
*/
nwords1 = nwords2 = ifmedia_getwords(ifm, NULL, 0);
IFMEDIA_IOCTL_UNLOCK(ifm);
if (ifmr->ifm_count != 0) {
int maxwords = MIN(nwords1, ifmr->ifm_count);
int *kptr = kmem_zalloc(maxwords * sizeof(int),
KM_SLEEP);
ifmedia_lock(ifm);
nwords2 = ifmedia_getwords(ifm, kptr, maxwords);
ifmedia_unlock(ifm);
error = copyout(kptr, ifmr->ifm_ulist,
maxwords * sizeof(int));
if (error == 0 && nwords2 > nwords1)
error = E2BIG; /* oops! */
kmem_free(kptr, maxwords * sizeof(int));
}
/* Update with the real number */
ifmr->ifm_count = nwords2;
break;
}
default:
error = EINVAL;
break;
}
KERNEL_UNLOCK_UNLESS_IFP_MPSAFE(ifp);
return error;
}
/*
* Find media entry matching a given ifm word.
*/
static struct ifmedia_entry *
ifmedia_match_locked(struct ifmedia *ifm, u_int target, u_int mask)
{
struct ifmedia_entry *match, *next;
match = NULL;
mask = ~mask;
TAILQ_FOREACH(next, &ifm->ifm_list, ifm_list) {
if ((next->ifm_media & mask) == (target & mask)) {
if (match) {
#if defined(IFMEDIA_DEBUG) || defined(DIAGNOSTIC)
printf("ifmedia_match: multiple match for "
"0x%x/0x%x, selected instance %d\n",
target, mask, IFM_INST(match->ifm_media));
#endif
break;
}
match = next;
}
}
return match;
}
struct ifmedia_entry *
ifmedia_match(struct ifmedia *ifm, u_int target, u_int mask)
{
struct ifmedia_entry *match;
/*
* N.B. We expect the caller is responsible fot the lifecycle
* of the media entries. Use with extreme caution.
*/
ifmedia_lock(ifm);
match = ifmedia_match_locked(ifm, target, mask);
ifmedia_unlock(ifm);
return match;
}
/*
* Delete all media for a given instance.
*/
void
ifmedia_delete_instance(struct ifmedia *ifm, u_int inst)
{
struct ifmedia_entry *ife, *nife;
TAILQ_HEAD(, ifmedia_entry) dead_entries;
TAILQ_INIT(&dead_entries);
ifmedia_lock(ifm);
TAILQ_FOREACH_SAFE(ife, &ifm->ifm_list, ifm_list, nife) {
if (inst == IFM_INST_ANY ||
inst == IFM_INST(ife->ifm_media)) {
if (ifm->ifm_cur == ife) {
ifm->ifm_cur = NULL;
ifm->ifm_media = IFM_NONE;
}
TAILQ_REMOVE(&ifm->ifm_list, ife, ifm_list);
TAILQ_INSERT_TAIL(&dead_entries, ife, ifm_list);
}
}
ifmedia_unlock(ifm);
TAILQ_FOREACH_SAFE(ife, &dead_entries, ifm_list, nife) {
TAILQ_REMOVE(&dead_entries, ife, ifm_list);
kmem_free(ife, sizeof(*ife));
}
}
void
ifmedia_removeall(struct ifmedia *ifm)
{
ifmedia_delete_instance(ifm, IFM_INST_ANY);
}
/*
* Compute the interface `baudrate' from the media, for the interface
* metrics (used by routing daemons).
*/
static const struct ifmedia_baudrate ifmedia_baudrate_descriptions[] =
IFM_BAUDRATE_DESCRIPTIONS;
uint64_t
ifmedia_baudrate(int mword)
{
int i;
for (i = 0; ifmedia_baudrate_descriptions[i].ifmb_word != 0; i++) {
if (IFM_TYPE_SUBTYPE_MATCH(mword,
ifmedia_baudrate_descriptions[i].ifmb_word))
return ifmedia_baudrate_descriptions[i].ifmb_baudrate;
}
/* Not known. */
return 0;
}
#ifdef IFMEDIA_DEBUG
static const struct ifmedia_description ifm_type_descriptions[] =
IFM_TYPE_DESCRIPTIONS;
static const struct ifmedia_description ifm_subtype_descriptions[] =
IFM_SUBTYPE_DESCRIPTIONS;
static const struct ifmedia_description ifm_option_descriptions[] =
IFM_OPTION_DESCRIPTIONS;
/*
* print a media word.
*/
static void
ifmedia_printword(int ifmw)
{
const struct ifmedia_description *desc;
int seen_option = 0;
/* Print the top-level interface type. */
for (desc = ifm_type_descriptions; desc->ifmt_string != NULL;
desc++) {
if (IFM_TYPE(ifmw) == desc->ifmt_word)
break;
}
if (desc->ifmt_string == NULL)
printf("<unknown type> ");
else
printf("%s ", desc->ifmt_string);
/* Print the subtype. */
for (desc = ifm_subtype_descriptions; desc->ifmt_string != NULL;
desc++) {
if (IFM_TYPE_MATCH(desc->ifmt_word, ifmw) &&
IFM_SUBTYPE(desc->ifmt_word) == IFM_SUBTYPE(ifmw))
break;
}
if (desc->ifmt_string == NULL)
printf("<unknown subtype>");
else
printf("%s", desc->ifmt_string);
/* Print any options. */
for (desc = ifm_option_descriptions; desc->ifmt_string != NULL;
desc++) {
if (IFM_TYPE_MATCH(desc->ifmt_word, ifmw) &&
(ifmw & desc->ifmt_word) != 0 &&
(seen_option & IFM_OPTIONS(desc->ifmt_word)) == 0) {
if (seen_option == 0)
printf(" <");
printf("%s%s", seen_option ? "," : "",
desc->ifmt_string);
seen_option |= IFM_OPTIONS(desc->ifmt_word);
}
}
printf("%s\n", seen_option ? ">" : "");
}
#endif /* IFMEDIA_DEBUG */