sockparams.c revision 5f1fdc187ec74acfbc49a47e07b89d7f64519f7b
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * CDDL HEADER START
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * The contents of this file are subject to the terms of the
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Common Development and Distribution License (the "License").
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * You may not use this file except in compliance with the License.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * See the License for the specific language governing permissions
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * and limitations under the License.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * When distributing Covered Code, include this CDDL HEADER in each
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * If applicable, add the following below this CDDL HEADER, with the
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * fields enclosed by brackets "[]" replaced with your own identifying
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * information: Portions Copyright [yyyy] [name of copyright owner]
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * CDDL HEADER END
5f1fdc187ec74acfbc49a47e07b89d7f64519f7bAnders Persson * Copyright (c) 1996, 2010, Oracle and/or its affiliates. All rights reserved.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Socket Parameters
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Socket parameter (struct sockparams) entries represent the socket types
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * available on the system.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Flags (sp_flags):
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * SOCKPARAMS_EPHEMERAL: A temporary sockparams entry that will be deleted
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * as soon as its' ref count drops to zero. In addition, ephemeral entries will
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * never be hooked onto the global sockparams list. Ephemeral entries are
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * created when application requests to create a socket using an application
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * supplied device path, or when a socket is falling back to TPI.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Lock order:
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * The lock order is splist_lock -> sp_lock.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * The lock order is sp_ephem_lock -> sp_lock.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningextern int kobj_path_exists(char *, int);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningextern void nl7c_init(void);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningstatic int sockparams_sdev_init(struct sockparams *, char *, int);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningstatic void sockparams_sdev_fini(struct sockparams *);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Global sockparams list (populated via soconfig(1M)).
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * List of ephemeral sockparams.
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson/* Global kstats for sockparams */
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning list_create(&sphead, sizeof (struct sockparams),
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning list_create(&sp_ephem_list, sizeof (struct sockparams),
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning rw_init(&sp_ephem_lock, NULL, RW_DEFAULT, NULL);
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson kstat_named_init(&sp_g_stats.spgs_ephem_nalloc, "ephemeral_nalloc",
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson kstat_named_init(&sp_g_stats.spgs_ephem_nreuse, "ephemeral_nreuse",
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson sp_g_kstat = kstat_create("sockfs", 0, "sockparams", "misc",
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson KSTAT_TYPE_NAMED, sizeof (sp_g_stats) / sizeof (kstat_named_t),
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson * Setup kstats for the given sockparams entry.
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson (void) snprintf(name, KSTAT_STRLEN, "socket_%d_%d_%d", sp->sp_family,
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson sp->sp_kstat = kstat_create("sockfs", 0, name, "misc", KSTAT_TYPE_NAMED,
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson sizeof (sockparams_stats_t) / sizeof (kstat_named_t),
7d64f41b87275bdc41b1f4cddb0fe3d951ef64bdAnders Persson sp->sp_kstat->ks_update = sockparams_kstat_update;
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sockparams_create(int family, int type, int protocol, char *modname,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * char *devpath, int devpathlen, int flags, int kmflags, int *errorp)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Create a new sockparams entry.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Arguments:
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * family, type, protocol: specifies the socket type
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * modname: Name of the module associated with the socket type. The
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * module can be NULL if a device path is given, in which
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * case the TPI module is used.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * devpath: Path to the STREAMS device. May be NULL for non-STREAMS
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * based transports, or those transports that do not provide
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * the capability to fallback to STREAMS.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * devpathlen: Length of the devpath string. The argument can be 0,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * indicating that devpath was allocated statically, and should
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * not be freed when the sockparams entry is destroyed.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * flags : SOCKPARAMS_EPHEMERAL is the only flag that is allowed.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * kmflags: KM_{NO,}SLEEP
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * errorp : Value-return argument, set when an error occurs.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * On success a new sockparams entry is returned, and *errorp is set
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * to 0. On failure NULL is returned and *errorp is set to indicate the
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * type of error that occured.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * devpath and modname are freed upon failure.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsockparams_create(int family, int type, int protocol, char *modname,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning char *devpath, int devpathlen, int flags, int kmflags, int *errorp)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning /* either a module or device must be given */
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson kstat_named_init(&sp->sp_stats.sps_nfallback, "nfallback",
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson kstat_named_init(&sp->sp_stats.sps_nactive, "nactive",
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson kstat_named_init(&sp->sp_stats.sps_ncreate, "ncreate",
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson * Track how many ephemeral entries we have created.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning (void) sprintf(sp->sp_smod_name, "%s", SOTPI_SMOD_NAME);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning /* Set up the device entry. */
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning *errorp = sockparams_sdev_init(sp, devpath, devpathlen);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning mutex_init(&sp->sp_lock, NULL, MUTEX_DEFAULT, NULL);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Initialize the STREAMS device aspect of the sockparams entry.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsockparams_sdev_init(struct sockparams *sp, char *devpath, int devpathlen)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning if ((error = sogetvp(devpath, &vp, UIO_SYSSPACE)) != 0) {
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning dprint(0, ("sockparams_sdev_init: vp %s failed with %d\n",
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sockparams_destroy(struct sockparams *sp)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Releases all the resources associated with the sockparams entry,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * and frees the sockparams entry.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Arguments:
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sp: the sockparams entry to destroy.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * The sp_lock of the entry can not be held.
5f1fdc187ec74acfbc49a47e07b89d7f64519f7bAnders Persson SMOD_DEC_REF(sp->sp_smod_info, sp->sp_smod_name);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning kmem_free(sp->sp_smod_name, strlen(sp->sp_smod_name) + 1);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Clean up the STREAMS device part of the sockparams entry.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * if the entry does not have a STREAMS device, then there
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * is nothing to do.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Look for a matching sockparams entry on the given list.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * The caller must hold the associated list lock.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningstatic struct sockparams *
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsockparams_find(list_t *list, int family, int type, int protocol,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning for (sp = list_head(list); sp != NULL; sp = list_next(list, sp)) {
22238f73378cc4cb6fd470f00810959bdd55aff6shenjian if (sp->sp_family == family && sp->sp_type == type) {
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sockparams_hold_ephemeral()
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Returns an ephemeral sockparams entry of the requested family, type and
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * protocol. The entry is returned held, and the caller is responsible for
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * dropping the reference using SOCKPARAMS_DEC_REF() once done.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * All ephemeral entries are on list (sp_ephem_list). If there is an
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * entry on the list that match the search criteria, then a reference is
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * placed on that entry. Otherwise, a new entry is created and inserted
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * in the list. The entry is removed from the list when the last reference
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * is dropped.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * The tpi flag is used to determine whether name refers to a device or
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * module name.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningstatic struct sockparams *
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsockparams_hold_ephemeral(int family, int type, int protocol,
22238f73378cc4cb6fd470f00810959bdd55aff6shenjian const char *name, boolean_t by_devpath, int kmflag, int *errorp)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * First look for an existing entry
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning sp = sockparams_find(&sp_ephem_list, family, type, protocol,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Time to load the socket module.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning /* Failed to load */
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * The sockparams entry was created, now try to add it
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * to the list. We need to hold the lock as a WRITER.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning sp = sockparams_find(&sp_ephem_list, family, type, protocol,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Someone has requested a matching entry, so just
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * place a hold on it and release the entry we alloc'ed.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsockparams_hold_ephemeral_bydev(int family, int type, int protocol,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning return (sockparams_hold_ephemeral(family, type, protocol, dev, B_TRUE,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsockparams_hold_ephemeral_bymod(int family, int type, int protocol,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning return (sockparams_hold_ephemeral(family, type, protocol, mod, B_FALSE,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Called when the last socket using the ephemeral entry is dropping
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * its' reference. To maintain lock order we must drop the sockparams
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * lock before calling this function. As a result, a new reference
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * might be placed on the entry, in which case there is nothing to
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * do. However, if ref count goes to zero, we delete the entry.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsockparams_ephemeral_drop_last_ref(struct sockparams *sp)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sockparams_add(struct sockparams *sp)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Tries to add the given sockparams entry to the global list.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Arguments:
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sp: the sockparms entry to add
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * On success 0, but if an entry already exists, then EEXIST
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * is returned.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * The caller can not be holding splist_lock.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning ASSERT(!(sp->sp_flags & SOCKPARAMS_EPHEMERAL));
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning if (sockparams_find(&sphead, sp->sp_family, sp->sp_type,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sockparams_delete(int family, int type, int protocol)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Marks the sockparams entry for a specific family, type and protocol
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * for deletion. The entry is removed from the list and destroyed
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * if no one is holding a reference to it.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Arguments:
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * family, type, protocol: the socket type that should be removed.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * On success 0, otherwise ENXIO.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Caller can not be holding splist_lock or the sp_lock of
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * any sockparams entry.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsockparams_delete(int family, int type, int protocol)
22238f73378cc4cb6fd470f00810959bdd55aff6shenjian sp = sockparams_find(&sphead, family, type, protocol, B_TRUE, NULL);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * If no one is holding a reference to the entry, then
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * we go ahead and remove it from the list and then
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * destroy it.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning /* Delete the sockparams entry. */
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * soconfig(int family, int type, int protocol,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * char *devpath, int devpathlen, char *module)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Add or delete an entry to the sockparams table.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * When devpath and module both are NULL, it will delete an entry.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Arguments:
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * family, type, protocol: the tuple in question
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * devpath: STREAMS device path. Can be NULL for module based sockets.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * module : Name of the socket module. Can be NULL for STREAMS
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * based sockets.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * devpathlen: length of the devpath string, or 0 if devpath
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * was statically allocated.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * This routine assumes that the caller has kmem_alloced
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * devpath (if devpathlen > 0) and module for this routine to
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Delete existing entry,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * both socket module and STEAMS device.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning error = sockparams_delete(family, type, protocol);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Adding an entry
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sockparams_create frees mod name and devpath upon failure.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning sp = sockparams_create(family, type, protocol, module,
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson * The sockparams entry becomes globally visible once
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson * we call sockparams_add(). So we add a reference so
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson * we do not have to worry about the entry being
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson * immediately deleted.
51899d8c0e357e637cdb75d1083ee3d64615b130Anders Persson * Unique sockparams entry, so init the kstats.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * solookup(int family, int type, int protocol, struct sockparams **spp)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Lookup an entry in the sockparams list based on the triple. The returned
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * entry either exactly match the given tuple, or it is the 'default' entry
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * for the given <family, type>. A default entry is on with a protocol
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * value of zero.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Arguments:
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * family, type, protocol: tuple to search for
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * spp: Value-return argument
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * If an entry is found, 0 is returned and *spp is set to point to the
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * entry. In case an entry is not found, *spp is set to NULL, and an
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * error code is returned. The errors are (in decreasing precedence):
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * EAFNOSUPPORT - address family not in list
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * EPROTONOSUPPORT - address family supported but not protocol.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * EPROTOTYPE - address family and protocol supported but not socket type.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * TODO: should use ddi_modopen()/ddi_modclose()
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangningsolookup(int family, int type, int protocol, struct sockparams **spp)
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Search the sockparams list for an appropiate entry.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Hopefully we find an entry that match the exact family,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * type and protocol specified by the user, in which case
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * we return that entry. However, we also keep track of
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * the default entry for a specific family and type, the
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * entry of which would have a protocol value of 0.
22238f73378cc4cb6fd470f00810959bdd55aff6shenjian sp = sockparams_find(&sphead, family, type, protocol, B_TRUE, NULL);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning /* Determine correct error code */
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * An entry was found.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * We put a hold on the entry early on, so if the
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sockmod is not loaded, and we have to exit
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * splist_lock to call modload(), we know that the
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * sockparams entry wont go away. That way we don't
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * have to look up the entry once we come back from
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * modload().
5f1fdc187ec74acfbc49a47e07b89d7f64519f7bAnders Persson smod_info_t *smod = smod_lookup_byname(sp->sp_smod_name);
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * We put a hold on the sockparams entry
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * earlier, hoping everything would work out.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * That obviously did not happen, so release
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * the hold here.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * We should probably mark the sockparams as
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * "bad", and redo the lookup skipping the
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * "bad" entries. I.e., sp->sp_mod_state |= BAD,
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * return (solookup(...))
5f1fdc187ec74acfbc49a47e07b89d7f64519f7bAnders Persson * Another thread might have already looked up the socket
5f1fdc187ec74acfbc49a47e07b89d7f64519f7bAnders Persson * module for this entry. In that case we need to drop our
5f1fdc187ec74acfbc49a47e07b89d7f64519f7bAnders Persson * reference to `smod' to ensure that the sockparams entry
5f1fdc187ec74acfbc49a47e07b89d7f64519f7bAnders Persson * only holds one reference.
0f1702c5201310f0529cd5abb77652e5e9b241b6Yu Xiangning * Alright, we have a valid sockparams entry.