lib/ipmgmtd/ipmgmt_persist.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * Contains DB walker functions, which are of type `db_wfunc_t';
 *
 * typedef boolean_t db_wfunc_t(void *cbarg, nvlist_t *db_nvl, char *buf,
 *				size_t bufsize, int *errp);
 *
 * ipadm_rw_db() walks through the data store, one line at a time and calls
 * these call back functions with:
 *	`cbarg'  - callback argument
 *	`db_nvl' - representing a line from DB in nvlist_t form
 *	`buf'	 - character buffer to hold modified line
 *	`bufsize'- size of the buffer
 *	`errp' - captures any error inside the walker function.
 *
 * All the 'write' callback functions modify `db_nvl' based on `cbarg' and
 * copy string representation of `db_nvl' (using ipadm_nvlist2str()) into `buf'.
 * To delete a line from the DB, buf[0] is set to `\0'. Inside ipadm_rw_db(),
 * the modified `buf' is written back into DB.
 *
 * All the 'read' callback functions, retrieve the information from the DB, by
 * reading `db_nvl' and then populate the `cbarg'.
 */

#include <stdlib.h>
#include <strings.h>
#include <errno.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include "ipmgmt_impl.h"

#define	ATYPE	"_atype"		/* name of the address type nvpair */
#define	FLAGS	"_flags"		/* name of the flags nvpair */

/*
 * flag used by ipmgmt_persist_aobjmap() to indicate address type is
 * IPADM_ADDR_IPV6_ADDRCONF.
 */
#define	IPMGMT_ATYPE_V6ACONF	0x1

extern pthread_rwlock_t ipmgmt_dbconf_lock;

/*
 * Checks if the database nvl, `db_nvl' contains and matches ALL of the passed
 * in private nvpairs `proto', `ifname' & `aobjname'.
 */
static boolean_t
ipmgmt_nvlist_match(nvlist_t *db_nvl, const char *proto, const char *ifname,
    const char *aobjname)
{
	char		*db_proto = NULL, *db_ifname = NULL;
	char		*db_aobjname = NULL;
	nvpair_t	*nvp;
	char		*name;

	/* walk through db_nvl and retrieve all its private nvpairs */
	for (nvp = nvlist_next_nvpair(db_nvl, NULL); nvp != NULL;
	    nvp = nvlist_next_nvpair(db_nvl, nvp)) {
		name = nvpair_name(nvp);
		if (strcmp(IPADM_NVP_PROTONAME, name) == 0)
			(void) nvpair_value_string(nvp, &db_proto);
		else if (strcmp(IPADM_NVP_IFNAME, name) == 0)
			(void) nvpair_value_string(nvp, &db_ifname);
		else if (strcmp(IPADM_NVP_AOBJNAME, name) == 0)
			(void) nvpair_value_string(nvp, &db_aobjname);
	}

	if (proto != NULL && proto[0] == '\0')
		proto = NULL;
	if (ifname != NULL && ifname[0] == '\0')
		ifname = NULL;
	if (aobjname != NULL && aobjname[0] == '\0')
		aobjname = NULL;

	if ((proto == NULL && db_proto != NULL) ||
	    (proto != NULL && db_proto == NULL) ||
	    strcmp(proto, db_proto) != 0) {
		/* no intersection - different protocols. */
		return (B_FALSE);
	}
	if ((ifname == NULL && db_ifname != NULL) ||
	    (ifname != NULL && db_ifname == NULL) ||
	    strcmp(ifname, db_ifname) != 0) {
		/* no intersection - different interfaces. */
		return (B_FALSE);
	}
	if ((aobjname == NULL && db_aobjname != NULL) ||
	    (aobjname != NULL && db_aobjname == NULL) ||
	    strcmp(aobjname, db_aobjname) != 0) {
		/* no intersection - different address objects */
		return (B_FALSE);
	}

	return (B_TRUE);
}

/*
 * Checks if the database nvl, `db_nvl' and the input nvl, `in_nvl' intersects.
 */
static boolean_t
ipmgmt_nvlist_intersects(nvlist_t *db_nvl, nvlist_t *in_nvl)
{
	nvpair_t	*nvp;
	char		*name;
	char		*proto = NULL, *ifname = NULL, *aobjname = NULL;

	/* walk through in_nvl and retrieve all its private nvpairs */
	for (nvp = nvlist_next_nvpair(in_nvl, NULL); nvp != NULL;
	    nvp = nvlist_next_nvpair(in_nvl, nvp)) {
		name = nvpair_name(nvp);
		if (strcmp(IPADM_NVP_PROTONAME, name) == 0)
			(void) nvpair_value_string(nvp, &proto);
		else if (strcmp(IPADM_NVP_IFNAME, name) == 0)
			(void) nvpair_value_string(nvp, &ifname);
		else if (strcmp(IPADM_NVP_AOBJNAME, name) == 0)
			(void) nvpair_value_string(nvp, &aobjname);
	}

	return (ipmgmt_nvlist_match(db_nvl, proto, ifname, aobjname));
}

/*
 * Checks if the database nvl, `db_nvl', contains and matches ANY of the passed
 * in private nvpairs `proto', `ifname' & `aobjname'.
 */
static boolean_t
ipmgmt_nvlist_contains(nvlist_t *db_nvl, const char *proto,
    const char *ifname, char *aobjname)
{
	char		*db_ifname = NULL, *db_proto = NULL;
	char		*db_aobjname = NULL;
	nvpair_t	*nvp;
	char		*name;

	/* walk through db_nvl and retrieve all private nvpairs */
	for (nvp = nvlist_next_nvpair(db_nvl, NULL); nvp != NULL;
	    nvp = nvlist_next_nvpair(db_nvl, nvp)) {
		name = nvpair_name(nvp);
		if (strcmp(IPADM_NVP_PROTONAME, name) == 0)
			(void) nvpair_value_string(nvp, &db_proto);
		else if (strcmp(IPADM_NVP_IFNAME, name) == 0)
			(void) nvpair_value_string(nvp, &db_ifname);
		else if (strcmp(IPADM_NVP_AOBJNAME, name) == 0)
			(void) nvpair_value_string(nvp, &db_aobjname);
	}

	if (proto != NULL && proto[0] != '\0') {
		if ((db_proto == NULL || strcmp(proto, db_proto) != 0))
			return (B_FALSE);
	}
	if (ifname != NULL && ifname[0] != '\0') {
		if ((db_ifname == NULL || strcmp(ifname, db_ifname) != 0))
			return (B_FALSE);
	}
	if (aobjname != NULL && aobjname[0] != '\0') {
		if ((db_aobjname == NULL || strcmp(aobjname, db_aobjname) != 0))
			return (B_FALSE);
	}

	return (B_TRUE);
}

/*
 * Retrieves the property value from the DB. The property whose value is to be
 * retrieved is in `pargp->ia_pname'.
 */
/* ARGSUSED */
boolean_t
ipmgmt_db_getprop(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	ipmgmt_prop_arg_t	*pargp = arg;
	boolean_t		cont = B_TRUE;
	char			*pval;
	int			err = 0;

	*errp = 0;

	if (!ipmgmt_nvlist_match(db_nvl, pargp->ia_module,
	    pargp->ia_ifname, pargp->ia_aobjname))
		return (B_TRUE);

	if ((err = nvlist_lookup_string(db_nvl, pargp->ia_pname,
	    &pval)) == 0) {
		(void) strlcpy(pargp->ia_pval, pval, sizeof (pargp->ia_pval));
		/*
		 * We have retrieved what we are looking for.
		 * Stop the walker.
		 */
		cont = B_FALSE;
	} else {
		if (err == ENOENT)
			err = 0;
		*errp = err;
	}

	return (cont);
}

/*
 * Removes the property value from the DB. The property whose value is to be
 * removed is in `pargp->ia_pname'.
 */
/* ARGSUSED */
boolean_t
ipmgmt_db_resetprop(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	ipmgmt_prop_arg_t	*pargp = arg;

	*errp = 0;
	if (!ipmgmt_nvlist_match(db_nvl, pargp->ia_module,
	    pargp->ia_ifname, pargp->ia_aobjname))
		return (B_TRUE);

	if (!nvlist_exists(db_nvl, pargp->ia_pname))
		return (B_TRUE);

	/*
	 * We found the property in the DB. If IPMGMT_REMOVE is not set then
	 * delete the entry from the db. If it is set, then the property is a
	 * multi-valued property so just remove the specified values from DB.
	 */
	if (pargp->ia_flags & IPMGMT_REMOVE) {
		char	*dbpval = NULL;
		char	*inpval = pargp->ia_pval;
		char	pval[MAXPROPVALLEN];
		char	*val, *lasts;

		*errp = nvlist_lookup_string(db_nvl, pargp->ia_pname, &dbpval);
		if (*errp != 0)
			return (B_FALSE);

		/*
		 * multi-valued properties are represented as comma separated
		 * values. Use string tokenizer functions to split them and
		 * search for the value to be removed.
		 */
		bzero(pval, sizeof (pval));
		if ((val = strtok_r(dbpval, ",", &lasts)) != NULL) {
			if (strcmp(val, inpval) != 0)
				(void) strlcat(pval, val, MAXPROPVALLEN);
			while ((val = strtok_r(NULL, ",", &lasts)) != NULL) {
				if (strcmp(val, inpval) != 0) {
					if (pval[0] != '\0')
						(void) strlcat(pval, ",",
						    MAXPROPVALLEN);
					(void) strlcat(pval, val,
					    MAXPROPVALLEN);
				}
			}
		} else {
			if (strcmp(dbpval, inpval) != 0)
				*errp = ENOENT;
			else
				buf[0] =  '\0';
			return (B_FALSE);
		}
		*errp = nvlist_add_string(db_nvl, pargp->ia_pname, pval);
		if (*errp != 0)
			return (B_FALSE);

		(void) memset(buf, 0, buflen);
		if (ipadm_nvlist2str(db_nvl, buf, buflen) == 0) {
			/* buffer overflow */
			*errp = ENOBUFS;
		}
	} else {
		buf[0] = '\0';
	}

	/* stop the search */
	return (B_FALSE);
}

/*
 * Input arguments can have IPADM_NVP_AOBJNAME or IPADM_NVP_IFNAME. A match is
 * found, when one of the following occurs first.
 * - the input aobjname matches the db aobjname. Return the db address.
 * - the input interface matches the db interface. Return all the
 *   matching db lines with addresses.
 */
/* ARGSUSED */
boolean_t
ipmgmt_db_getaddr(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	ipmgmt_getaddr_cbarg_t	*cbarg = arg;
	char		*db_aobjname = NULL;
	char		*db_ifname = NULL;
	nvlist_t	*db_addr = NULL;
	char		name[IPMGMT_STRSIZE];
	nvpair_t	*nvp;
	boolean_t	add_nvl = B_FALSE;

	/* Parse db nvlist */
	for (nvp = nvlist_next_nvpair(db_nvl, NULL); nvp != NULL;
	    nvp = nvlist_next_nvpair(db_nvl, nvp)) {
		if (nvpair_type(nvp) == DATA_TYPE_NVLIST)
			(void) nvpair_value_nvlist(nvp, &db_addr);
		else if (strcmp(nvpair_name(nvp), IPADM_NVP_IFNAME) == 0)
			(void) nvpair_value_string(nvp, &db_ifname);
		else if (strcmp(nvpair_name(nvp), IPADM_NVP_AOBJNAME) == 0)
			(void) nvpair_value_string(nvp, &db_aobjname);
	}

	if (db_aobjname == NULL) /* Not an address */
		return (B_TRUE);

	/* Check for a match between the aobjnames or the interface name */
	if (cbarg->cb_aobjname[0] != '\0') {
		if (strcmp(cbarg->cb_aobjname, db_aobjname) == 0)
			add_nvl = B_TRUE;
	} else if (cbarg->cb_ifname[0] != '\0') {
		if (strcmp(cbarg->cb_ifname, db_ifname) == 0)
			add_nvl = B_TRUE;
	} else {
		add_nvl = B_TRUE;
	}

	if (add_nvl) {
		(void) snprintf(name, sizeof (name), "%s_%d", db_ifname,
		    cbarg->cb_ocnt);
		*errp = nvlist_add_nvlist(cbarg->cb_onvl, name, db_nvl);
		if (*errp == 0)
			cbarg->cb_ocnt++;
	}
	return (B_TRUE);
}

/*
 * This function takes the appropriate lock, read or write, based on the
 * `db_op' and then calls DB walker ipadm_rw_db().
 */
extern int
ipmgmt_db_walk(db_wfunc_t *db_walk_func, void *db_warg, ipadm_db_op_t db_op)
{
	int		err;
	boolean_t	writeop;
	mode_t		mode;

	writeop = (db_op != IPADM_DB_READ);

	if (writeop) {
		(void) pthread_rwlock_wrlock(&ipmgmt_dbconf_lock);
		mode = IPADM_FILE_MODE;
	} else {
		(void) pthread_rwlock_rdlock(&ipmgmt_dbconf_lock);
		mode = 0;
	}

	err = ipadm_rw_db(db_walk_func, db_warg, IPADM_DB_FILE, mode, db_op);
	(void) pthread_rwlock_unlock(&ipmgmt_dbconf_lock);
	return (err);
}

/*
 * Used to add an entry towards the end of DB. It just returns B_TRUE for
 * every line of the DB. When we reach the end, ipadm_rw_db() adds the
 * line at the end.
 */
/* ARGSUSED */
boolean_t
ipmgmt_db_add(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen, int *errp)
{
	return (B_TRUE);
}

/*
 * This function is used to update or create an entry in DB. The nvlist_t,
 * `in_nvl', represents the line we are looking for. Once we ensure the right
 * line from DB, we update that entry.
 */
boolean_t
ipmgmt_db_update(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	ipadm_dbwrite_cbarg_t	*cb = arg;
	uint_t			flags = cb->dbw_flags;
	nvlist_t		*in_nvl = cb->dbw_nvl;
	nvpair_t		*nvp;
	char			*name, *instrval = NULL, *dbstrval = NULL;
	char			pval[MAXPROPVALLEN];

	if (!ipmgmt_nvlist_intersects(db_nvl, in_nvl))
		return (B_TRUE);

	for (nvp = nvlist_next_nvpair(in_nvl, NULL); nvp != NULL;
	    nvp = nvlist_next_nvpair(in_nvl, nvp)) {
		name = nvpair_name(nvp);
		if (!IPADM_PRIV_NVP(name) && nvlist_exists(db_nvl, name))
			break;
	}

	if (nvp == NULL)
		return (B_TRUE);

	assert(nvpair_type(nvp) == DATA_TYPE_STRING);

	if ((*errp = nvpair_value_string(nvp, &instrval)) != 0)
		return (B_FALSE);

	/*
	 * If IPMGMT_APPEND is set then we are dealing with multi-valued
	 * properties. We append to the entry from the db, with the new value.
	 */
	if (flags & IPMGMT_APPEND) {
		if ((*errp = nvlist_lookup_string(db_nvl, name,
		    &dbstrval)) != 0)
			return (B_FALSE);
		(void) snprintf(pval, MAXPROPVALLEN, "%s,%s", dbstrval,
		    instrval);
		if ((*errp = nvlist_add_string(db_nvl, name, pval)) != 0)
			return (B_FALSE);
	} else {
		/* case	of in-line update of a db entry */
		if ((*errp = nvlist_add_string(db_nvl, name, instrval)) != 0)
			return (B_FALSE);
	}

	(void) memset(buf, 0, buflen);
	if (ipadm_nvlist2str(db_nvl, buf, buflen) == 0) {
		/* buffer overflow */
		*errp = ENOBUFS;
	}
	*errp = 0;

	/* we updated the DB entry, so do not continue */
	return (B_FALSE);
}

/*
 * For the given `cbarg->cb_ifname' interface, retrieves any persistent
 * interface information (used in 'ipadm show-if')
 */
/* ARGSUSED */
boolean_t
ipmgmt_db_getif(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	ipmgmt_getif_cbarg_t	*cbarg = arg;
	char			*ifname = cbarg->cb_ifname;
	char			*intf = NULL;
	ipadm_if_info_t		*ifp = NULL;
	sa_family_t		af;
	char			*afstr;

	*errp = 0;
	if (nvlist_lookup_string(db_nvl, IPADM_NVP_FAMILY, &afstr) != 0 ||
	    nvlist_lookup_string(db_nvl, IPADM_NVP_IFNAME, &intf) != 0 ||
	    (ifname[0] != '\0' && strcmp(ifname, intf) != 0)) {
		return (B_TRUE);
	}
	af = atoi(afstr);
	for (ifp = cbarg->cb_ifinfo; ifp != NULL; ifp = ifp->ifi_next) {
		if (strcmp(ifp->ifi_name, intf) == 0)
			break;
	}
	if (ifp == NULL) {
		ipadm_if_info_t *new;

		if ((new = calloc(1, sizeof (*new))) == NULL) {
			*errp = ENOMEM;
			return (B_FALSE); /* don't continue the walk */
		}
		new->ifi_next = cbarg->cb_ifinfo;
		cbarg->cb_ifinfo = new;
		ifp = new;
		(void) strlcpy(ifp->ifi_name, intf, sizeof (ifp->ifi_name));
	}

	if (af == AF_INET) {
		ifp->ifi_pflags |= IFIF_IPV4;
	} else {
		assert(af == AF_INET6);
		ifp->ifi_pflags |= IFIF_IPV6;
	}

	/* Terminate the walk if we found both v4 and v6 interfaces. */
	if (ifname[0] != '\0' && (ifp->ifi_pflags & IFIF_IPV4) &&
	    (ifp->ifi_pflags & IFIF_IPV6))
		return (B_FALSE);

	return (B_TRUE);
}

/*
 * Deletes those entries from the database for which interface name
 * matches with the given `cbarg->cb_ifname'
 */
/* ARGSUSED */
boolean_t
ipmgmt_db_resetif(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	ipmgmt_if_cbarg_t *cbarg = arg;
	boolean_t	isv6 = (cbarg->cb_family == AF_INET6);
	char		*ifname = cbarg->cb_ifname;
	char		*modstr = NULL;
	char		*afstr;
	char		*aobjname;
	uint_t		proto;
	ipmgmt_aobjmap_t *head;
	boolean_t	aobjfound = B_FALSE;

	*errp = 0;

	if (!ipmgmt_nvlist_contains(db_nvl, NULL, ifname, NULL))
		return (B_TRUE);

	if (nvlist_lookup_string(db_nvl, IPADM_NVP_FAMILY, &afstr) == 0) {
		if (atoi(afstr) == cbarg->cb_family)
			goto delete;
		return (B_TRUE);
	}

	/* Reset all the interface configurations for 'ifname' */
	if (isv6 && (nvlist_exists(db_nvl, IPADM_NVP_IPV6ADDR) ||
	    nvlist_exists(db_nvl, IPADM_NVP_INTFID))) {
		goto delete;
	}
	if (!isv6 &&
	    (nvlist_exists(db_nvl, IPADM_NVP_IPV4ADDR) ||
	    nvlist_exists(db_nvl, IPADM_NVP_DHCP))) {
		goto delete;
	}

	if (nvlist_lookup_string(db_nvl, IPADM_NVP_AOBJNAME, &aobjname) == 0) {
		/*
		 * This must be an address property. Delete this
		 * line if there is a match in the address family.
		 */
		head = aobjmap.aobjmap_head;
		while (head != NULL) {
			if (strcmp(head->am_aobjname, aobjname) == 0) {
				aobjfound = B_TRUE;
				if (head->am_family == cbarg->cb_family)
					goto delete;
			}
			head = head->am_next;
		}
		/*
		 * If aobjfound = B_FALSE, then this address is not
		 * available in active configuration. We should go ahead
		 * and delete it.
		 */
		if (!aobjfound)
			goto delete;
	}

	/*
	 * If we are removing both v4 and v6 interface, then we get rid of
	 * all the properties for that interface. On the other hand, if we
	 * are deleting only v4 instance of an interface, then we delete v4
	 * properties only.
	 */
	if (nvlist_lookup_string(db_nvl, IPADM_NVP_PROTONAME, &modstr) == 0) {
		proto = ipadm_str2proto(modstr);
		switch (proto) {
		case MOD_PROTO_IPV6:
			if (isv6)
				goto delete;
			break;
		case MOD_PROTO_IPV4:
			if (!isv6)
				goto delete;
			break;
		case MOD_PROTO_IP:
			/* this should never be the case, today */
			assert(0);
			break;
		}
	}
	/* Not found a match yet. Continue processing the db */
	return (B_TRUE);
delete:
	/* delete the line from the db */
	buf[0] = '\0';
	return (B_TRUE);
}

/*
 * Deletes those entries from the database for which address object name
 * matches with the given `cbarg->cb_aobjname'
 */
/* ARGSUSED */
boolean_t
ipmgmt_db_resetaddr(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	ipmgmt_resetaddr_cbarg_t *cbarg = arg;
	char		*aobjname = cbarg->cb_aobjname;

	*errp = 0;
	if (!ipmgmt_nvlist_contains(db_nvl, NULL, NULL, aobjname))
		return (B_TRUE);

	/* delete the line from the db */
	buf[0] = '\0';
	return (B_TRUE);
}

/*
 * Retrieves all interface props, including addresses, for given interface(s).
 * `invl' contains the list of interfaces, for which information need to be
 * retrieved.
 */
/* ARGSUSED */
boolean_t
ipmgmt_db_initif(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	ipmgmt_initif_cbarg_t	*cbarg = arg;
	nvlist_t		*onvl = cbarg->cb_onvl;
	nvlist_t		*invl = cbarg->cb_invl;
	sa_family_t		in_af = cbarg->cb_family;
	char			*db_ifname;

	*errp = 0;
	if (nvlist_lookup_string(db_nvl, IPADM_NVP_IFNAME, &db_ifname) == 0 &&
	    nvlist_exists(invl, db_ifname)) {
		char		name[IPMGMT_STRSIZE];
		sa_family_t	db_af = in_af;
		uint_t		proto;
		char		*pstr;

		if (in_af != AF_UNSPEC) {
			if (nvlist_lookup_string(db_nvl, IPADM_NVP_PROTONAME,
			    &pstr) == 0) {
				proto = ipadm_str2proto(pstr);
				if (proto == MOD_PROTO_IPV4)
					db_af = AF_INET;
				else if (proto == MOD_PROTO_IPV6)
					db_af = AF_INET6;
				else
					db_af = in_af;
			} else {
				if (nvlist_exists(db_nvl, IPADM_NVP_IPV4ADDR) ||
				    nvlist_exists(db_nvl, IPADM_NVP_DHCP))
					db_af = AF_INET;
				else
					db_af = AF_INET6;
			}
		}
		if (in_af == db_af) {
			(void) snprintf(name, sizeof (name), "%s_%d", db_ifname,
			    cbarg->cb_ocnt);
			*errp = nvlist_add_nvlist(onvl, name, db_nvl);
			if (*errp == 0)
				cbarg->cb_ocnt++;
		}
	}
	return (B_TRUE);
}

/*
 * helper function for ipmgmt_aobjmap_op(). Adds the node pointed by `nodep'
 * into `aobjmap' structure.
 */
static int
i_ipmgmt_add_amnode(ipmgmt_aobjmap_t *nodep)
{
	ipmgmt_aobjmap_t	*new, *head;

	head = aobjmap.aobjmap_head;
	if ((new = malloc(sizeof (ipmgmt_aobjmap_t))) == NULL)
		return (ENOMEM);
	*new = *nodep;
	new->am_next = NULL;

	/* Add the node at the beginning of the list */
	if (head == NULL) {
		aobjmap.aobjmap_head = new;
	} else {
		new->am_next = aobjmap.aobjmap_head;
		aobjmap.aobjmap_head = new;
	}
	return (0);
}

/*
 * A recursive function to generate alphabetized number given a decimal number.
 * Decimal 0 to 25 maps to 'a' to 'z' and then the counting continues with 'aa',
 * 'ab', 'ac', et al.
 */
static void
i_ipmgmt_num2priv_aobjname(uint32_t num, char **cp, char *endp)
{
	if (num >= 26)
		i_ipmgmt_num2priv_aobjname(num / 26 - 1, cp, endp);
	if (*cp != endp) {
		*cp[0] = 'a' + (num % 26);
		(*cp)++;
	}
}

/*
 * This function generates an `aobjname', when required, and then does
 * lookup-add. If `nodep->am_aobjname' is not an empty string, then it walks
 * through the `aobjmap' to check if an address object with the same
 * `nodep->am_aobjname' exists. If it exists, EEXIST is returned as duplicate
 * `aobjname's are not allowed.
 *
 * If `nodep->am_aobjname' is an empty string then the daemon generates an
 * `aobjname' using the `am_nextnum', which contains the next number to be
 * used to generate `aobjname'. `am_nextnum' is converted to base26 using
 * `a-z' alphabets in i_ipmgmt_num2priv_aobjname().
 *
 * `am_nextnum' will be 0 to begin with. Every time an address object that
 * needs `aobjname' is added it's incremented by 1. So for the first address
 * object on net0 the `am_aobjname' will be net0/_a and `am_nextnum' will be 1.
 * For the second address object on that interface `am_aobjname' will be net0/_b
 * and  `am_nextnum' will incremented to 2.
 */
static int
i_ipmgmt_lookupadd_amnode(ipmgmt_aobjmap_t *nodep)
{
	ipmgmt_aobjmap_t	*head;
	uint32_t		nextnum;

	for (head = aobjmap.aobjmap_head; head != NULL; head = head->am_next)
		if (strcmp(head->am_ifname, nodep->am_ifname) == 0)
			break;
	nextnum = (head == NULL ? 0 : head->am_nextnum);

	/*
	 * if `aobjname' is empty, then the daemon has to generate the
	 * next `aobjname' for the given interface and family.
	 */
	if (nodep->am_aobjname[0] == '\0') {
		char tmpstr[IPADM_AOBJ_USTRSIZ - 1];  /* 1 for leading  '_' */
		char *cp = tmpstr;
		char *endp = tmpstr + sizeof (tmpstr);

		i_ipmgmt_num2priv_aobjname(nextnum, &cp, endp);

		if (cp == endp)
			return (EINVAL);
		cp[0] = '\0';

		if (snprintf(nodep->am_aobjname, IPADM_AOBJSIZ, "%s/_%s",
		    nodep->am_ifname, tmpstr) >= IPADM_AOBJSIZ) {
			return (EINVAL);
		}
		nodep->am_nextnum = ++nextnum;
	} else {
		for (head = aobjmap.aobjmap_head; head != NULL;
		    head = head->am_next) {
			if (strcmp(head->am_aobjname, nodep->am_aobjname) == 0)
				return (EEXIST);
		}
		nodep->am_nextnum = nextnum;
	}
	return (i_ipmgmt_add_amnode(nodep));
}

/*
 * Performs following operations on the global `aobjmap' linked list.
 * (a) ADDROBJ_ADD: add or update address object in `aobjmap'
 * (b) ADDROBJ_DELETE: delete address object from `aobjmap'
 * (c) ADDROBJ_LOOKUPADD: place a stub address object in `aobjmap'
 * (d) ADDROBJ_SETLIFNUM: Sets the lifnum for an address object in `aobjmap'
 */
int
ipmgmt_aobjmap_op(ipmgmt_aobjmap_t *nodep, uint32_t op)
{
	ipmgmt_aobjmap_t	*head, *prev, *matched = NULL;
	boolean_t		update = B_TRUE;
	int			err = 0;
	ipadm_db_op_t		db_op;

	(void) pthread_rwlock_wrlock(&aobjmap.aobjmap_rwlock);

	head = aobjmap.aobjmap_head;
	switch (op) {
	case ADDROBJ_ADD:
		/*
		 * check for stub nodes (added by ADDROBJ_LOOKUPADD) and
		 * update, else add the new node.
		 */
		for (; head != NULL; head = head->am_next) {
			/*
			 * For IPv6, we need to distinguish between the
			 * linklocal and non-linklocal nodes
			 */
			if (strcmp(head->am_aobjname,
			    nodep->am_aobjname) == 0 &&
			    (head->am_atype != IPADM_ADDR_IPV6_ADDRCONF ||
			    head->am_linklocal == nodep->am_linklocal))
				break;
		}

		if (head != NULL) {
			/* update the node */
			(void) strlcpy(head->am_ifname, nodep->am_ifname,
			    sizeof (head->am_ifname));
			head->am_lnum = nodep->am_lnum;
			head->am_family = nodep->am_family;
			head->am_flags = nodep->am_flags;
			head->am_atype = nodep->am_atype;
			if (head->am_atype == IPADM_ADDR_IPV6_ADDRCONF) {
				head->am_ifid = nodep->am_ifid;
				head->am_linklocal = nodep->am_linklocal;
			}
		} else {
			for (head = aobjmap.aobjmap_head; head != NULL;
			    head = head->am_next) {
				if (strcmp(head->am_ifname,
				    nodep->am_ifname) == 0)
					break;
			}
			nodep->am_nextnum = (head == NULL ? 0 :
			    head->am_nextnum);
			err = i_ipmgmt_add_amnode(nodep);
		}
		db_op = IPADM_DB_WRITE;
		break;
	case ADDROBJ_DELETE:
		prev = head;
		while (head != NULL) {
			if (strcmp(head->am_aobjname,
			    nodep->am_aobjname) == 0) {
				nodep->am_atype = head->am_atype;
				/*
				 * There could be multiple IPV6_ADDRCONF nodes,
				 * with same address object name, so check for
				 * logical number also.
				 */
				if (head->am_atype !=
				    IPADM_ADDR_IPV6_ADDRCONF ||
				    nodep->am_lnum == head->am_lnum)
					break;
			}
			prev = head;
			head = head->am_next;
		}
		if (head != NULL) {
			/*
			 * If the address object is in both active and
			 * persistent configuration and the user is deleting it
			 * only from active configuration then mark this node
			 * for deletion by reseting IPMGMT_ACTIVE bit.
			 * With this the same address object name cannot
			 * be reused until it is permanently removed.
			 */
			if (head->am_flags == (IPMGMT_ACTIVE|IPMGMT_PERSIST) &&
			    nodep->am_flags == IPMGMT_ACTIVE) {
				/* Update flags in the in-memory map. */
				head->am_flags &= ~IPMGMT_ACTIVE;
				head->am_lnum = -1;

				/* Update info in file. */
				db_op = IPADM_DB_WRITE;
				*nodep = *head;
			} else {
				(void) strlcpy(nodep->am_ifname,
				    head->am_ifname,
				    sizeof (nodep->am_ifname));
				/* otherwise delete the node */
				if (head == aobjmap.aobjmap_head)
					aobjmap.aobjmap_head = head->am_next;
				else
					prev->am_next = head->am_next;
				free(head);
				db_op = IPADM_DB_DELETE;
			}
		} else {
			err = ENOENT;
		}
		break;
	case ADDROBJ_LOOKUPADD:
		err = i_ipmgmt_lookupadd_amnode(nodep);
		update = B_FALSE;
		break;
	case ADDROBJ_SETLIFNUM:
		update = B_FALSE;
		for (; head != NULL; head = head->am_next) {
			if (strcmp(head->am_ifname,
			    nodep->am_ifname) == 0 &&
			    head->am_family == nodep->am_family &&
			    head->am_lnum == nodep->am_lnum) {
				err = EEXIST;
				break;
			}
			if (strcmp(head->am_aobjname,
			    nodep->am_aobjname) == 0) {
				matched = head;
			}
		}
		if (err == EEXIST)
			break;
		if (matched != NULL) {
			/* update the lifnum */
			matched->am_lnum = nodep->am_lnum;
		} else {
			err = ENOENT;
		}
		break;
	default:
		assert(0);
	}

	if (err == 0 && update)
		err = ipmgmt_persist_aobjmap(nodep, db_op);

	(void) pthread_rwlock_unlock(&aobjmap.aobjmap_rwlock);

	return (err);
}

/*
 * Given a node in `aobjmap', this function converts it into nvlist_t structure.
 * The content to be written to DB must be represented as nvlist_t.
 */
static int
i_ipmgmt_node2nvl(nvlist_t **nvl, ipmgmt_aobjmap_t *np)
{
	int	err;
	char	strval[IPMGMT_STRSIZE];

	*nvl = NULL;
	if ((err = nvlist_alloc(nvl, NV_UNIQUE_NAME, 0)) != 0)
		goto fail;

	if ((err = nvlist_add_string(*nvl, IPADM_NVP_AOBJNAME,
	    np->am_aobjname)) != 0)
		goto fail;

	if ((err = nvlist_add_string(*nvl, IPADM_NVP_IFNAME,
	    np->am_ifname)) != 0)
		goto fail;

	(void) snprintf(strval, IPMGMT_STRSIZE, "%d", np->am_lnum);
	if ((err = nvlist_add_string(*nvl, IPADM_NVP_LIFNUM, strval)) != 0)
		goto fail;

	(void) snprintf(strval, IPMGMT_STRSIZE, "%d", np->am_family);
	if ((err = nvlist_add_string(*nvl, IPADM_NVP_FAMILY, strval)) != 0)
		goto fail;

	(void) snprintf(strval, IPMGMT_STRSIZE, "%d", np->am_flags);
	if ((err = nvlist_add_string(*nvl, FLAGS, strval)) != 0)
		goto fail;

	(void) snprintf(strval, IPMGMT_STRSIZE, "%d", np->am_atype);
	if ((err = nvlist_add_string(*nvl, ATYPE, strval)) != 0)
		goto fail;

	if (np->am_atype == IPADM_ADDR_IPV6_ADDRCONF) {
		struct sockaddr_in6	*in6;

		in6 = (struct sockaddr_in6 *)&np->am_ifid;
		if (np->am_linklocal &&
		    IN6_IS_ADDR_UNSPECIFIED(&in6->sin6_addr)) {
			if ((err = nvlist_add_string(*nvl, IPADM_NVP_IPNUMADDR,
			    "default")) != 0)
				goto fail;
		} else {
			if (inet_ntop(AF_INET6, &in6->sin6_addr, strval,
			    IPMGMT_STRSIZE) == NULL) {
				err = errno;
				goto fail;
			}
			if ((err = nvlist_add_string(*nvl, IPADM_NVP_IPNUMADDR,
			    strval)) != 0)
				goto fail;
		}
	} else {
		if ((err = nvlist_add_string(*nvl, IPADM_NVP_IPNUMADDR,
		    "")) != 0)
			goto fail;
	}
	return (err);
fail:
	nvlist_free(*nvl);
	return (err);
}

/*
 * Read the aobjmap data store and build the in-memory representation
 * of the aobjmap. We don't need to hold any locks while building this as
 * we do this in very early stage of daemon coming up, even before the door
 * is opened.
 */
/* ARGSUSED */
extern boolean_t
ipmgmt_aobjmap_init(void *arg, nvlist_t *db_nvl, char *buf, size_t buflen,
    int *errp)
{
	nvpair_t		*nvp = NULL;
	char			*name, *strval = NULL;
	ipmgmt_aobjmap_t 	node;
	struct sockaddr_in6	*in6;

	*errp = 0;
	node.am_next = NULL;
	for (nvp = nvlist_next_nvpair(db_nvl, NULL); nvp != NULL;
	    nvp = nvlist_next_nvpair(db_nvl, nvp)) {
		name = nvpair_name(nvp);

		if ((*errp = nvpair_value_string(nvp, &strval)) != 0)
			return (B_TRUE);
		if (strcmp(IPADM_NVP_AOBJNAME, name) == 0) {
			(void) strlcpy(node.am_aobjname, strval,
			    sizeof (node.am_aobjname));
		} else if (strcmp(IPADM_NVP_IFNAME, name) == 0) {
			(void) strlcpy(node.am_ifname, strval,
			    sizeof (node.am_ifname));
		} else if (strcmp(IPADM_NVP_LIFNUM, name) == 0) {
			node.am_lnum = atoi(strval);
		} else if (strcmp(IPADM_NVP_FAMILY, name) == 0) {
			node.am_family = (sa_family_t)atoi(strval);
		} else if (strcmp(FLAGS, name) == 0) {
			node.am_flags = atoi(strval);
		} else if (strcmp(ATYPE, name) == 0) {
			node.am_atype = (ipadm_addr_type_t)atoi(strval);
		} else if (strcmp(IPADM_NVP_IPNUMADDR, name) == 0) {
			if (node.am_atype == IPADM_ADDR_IPV6_ADDRCONF) {
				in6 = (struct sockaddr_in6 *)&node.am_ifid;
				if (strcmp(strval, "default") == 0) {
					bzero(in6, sizeof (node.am_ifid));
					node.am_linklocal = B_TRUE;
				} else {
					(void) inet_pton(AF_INET6, strval,
					    &in6->sin6_addr);
					if (IN6_IS_ADDR_UNSPECIFIED(
					    &in6->sin6_addr))
						node.am_linklocal = B_TRUE;
				}
			}
		}
	}

	/* we have all the information we need, add the node */
	*errp = i_ipmgmt_add_amnode(&node);

	return (B_TRUE);
}

/*
 * Updates an entry from the temporary cache file, which matches the given
 * address object name.
 */
/* ARGSUSED */
static boolean_t
ipmgmt_update_aobjmap(void *arg, nvlist_t *db_nvl, char *buf,
    size_t buflen, int *errp)
{
	ipadm_dbwrite_cbarg_t	*cb = arg;
	nvlist_t		*in_nvl = cb->dbw_nvl;
	uint32_t		flags = cb->dbw_flags;
	char			*db_lifnumstr = NULL, *in_lifnumstr = NULL;

	*errp = 0;
	if (!ipmgmt_nvlist_intersects(db_nvl, in_nvl))
		return (B_TRUE);

	if (flags & IPMGMT_ATYPE_V6ACONF) {
		if (nvlist_lookup_string(db_nvl, IPADM_NVP_LIFNUM,
		    &db_lifnumstr) != 0 ||
		    nvlist_lookup_string(in_nvl, IPADM_NVP_LIFNUM,
		    &in_lifnumstr) != 0 ||
		    (atoi(db_lifnumstr) != -1 && atoi(in_lifnumstr) != -1 &&
		    strcmp(db_lifnumstr, in_lifnumstr) != 0))
			return (B_TRUE);
	}

	/* we found the match */
	(void) memset(buf, 0, buflen);
	if (ipadm_nvlist2str(in_nvl, buf, buflen) == 0) {
		/* buffer overflow */
		*errp = ENOBUFS;
	}

	/* stop the walker */
	return (B_FALSE);
}

/*
 * Deletes an entry from the temporary cache file, which matches the given
 * address object name.
 */
/* ARGSUSED */
static boolean_t
ipmgmt_delete_aobjmap(void *arg, nvlist_t *db_nvl, char *buf,
    size_t buflen, int *errp)
{
	ipmgmt_aobjmap_t	*nodep = arg;
	char			*db_lifnumstr = NULL;

	*errp = 0;
	if (!ipmgmt_nvlist_match(db_nvl, NULL, nodep->am_ifname,
	    nodep->am_aobjname))
		return (B_TRUE);

	if (nodep->am_atype == IPADM_ADDR_IPV6_ADDRCONF) {
		if (nvlist_lookup_string(db_nvl, IPADM_NVP_LIFNUM,
		    &db_lifnumstr) != 0 || atoi(db_lifnumstr) != nodep->am_lnum)
			return (B_TRUE);
	}

	/* we found the match, delete the line from the db */
	buf[0] = '\0';

	/* stop the walker */
	return (B_FALSE);
}

/*
 * Adds or deletes aobjmap node information into a temporary cache file.
 */
extern int
ipmgmt_persist_aobjmap(ipmgmt_aobjmap_t *nodep, ipadm_db_op_t op)
{
	int			err;
	ipadm_dbwrite_cbarg_t	cb;
	nvlist_t		*nvl = NULL;

	if (op == IPADM_DB_WRITE) {
		if ((err = i_ipmgmt_node2nvl(&nvl, nodep)) != 0)
			return (err);
		cb.dbw_nvl = nvl;
		if (nodep->am_atype == IPADM_ADDR_IPV6_ADDRCONF)
			cb.dbw_flags = IPMGMT_ATYPE_V6ACONF;
		else
			cb.dbw_flags = 0;

		err = ipadm_rw_db(ipmgmt_update_aobjmap, &cb,
		    ADDROBJ_MAPPING_DB_FILE, IPADM_FILE_MODE, IPADM_DB_WRITE);
		nvlist_free(nvl);
	} else {
		assert(op == IPADM_DB_DELETE);

		err = ipadm_rw_db(ipmgmt_delete_aobjmap, nodep,
		    ADDROBJ_MAPPING_DB_FILE, IPADM_FILE_MODE, IPADM_DB_DELETE);
	}
	return (err);
}