/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Contains routines that deal with TLI/XTI endpoints and rpc services.
 */

#include <sys/types.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <libintl.h>
#include <unistd.h>
#include <sys/sysmacros.h>
#include <netconfig.h>
#include <errno.h>
#include <sys/sockio.h>
#include "inetd_impl.h"

uu_list_pool_t *conn_ind_pool = NULL;

/*
 * RPC functions.
 */

/*
 * Returns B_TRUE if the non-address components of the 2 rpc_info_t structures
 * are equivalent, else B_FALSE.
 */
boolean_t
rpc_info_equal(const rpc_info_t *ri, const rpc_info_t *ri2)
{
        return ((ri->prognum == ri2->prognum) &&
            (ri->lowver == ri2->lowver) &&
            (ri->highver == ri2->highver) &&
            (strcmp(ri->netid, ri2->netid) == 0));
}

/*
 * Determine if we have a configured interface for the specified address
 * family. This code is a mirror of libnsl's __can_use_af(). We mirror
 * it because we need an exact duplicate of its behavior, yet the
 * function isn't exported by libnsl, and this fix is considered short-
 * term, so it's not worth exporting it.
 *
 * We need to duplicate __can_use_af() so we can accurately determine
 * when getnetconfigent() returns failure for a v6 netid due to no IPv6
 * interfaces being configured: getnetconfigent() returns failure
 * if a netid is either 'tcp6' or 'udp6' and __can_use_af() returns 0,
 * but it doesn't return a return code to uniquely determine this
 * failure. If we don't accurately determine these failures, we could
 * output error messages in a case when they weren't justified.
 */
static int
can_use_af(sa_family_t af)
{
        struct lifnum   lifn;
        int             fd;

        if ((fd =  open("/dev/udp", O_RDONLY)) < 0) {
                return (0);
        }
        lifn.lifn_family = af;
        /* LINTED ECONST_EXPR */
        lifn.lifn_flags = IFF_UP & !(IFF_NOXMIT | IFF_DEPRECATED);
        if (ioctl(fd, SIOCGLIFNUM, &lifn, sizeof (lifn)) < 0) {
                lifn.lifn_count = 0;
        }

        (void) close(fd);
        return (lifn.lifn_count);
}

static boolean_t
is_v6_netid(const char *netid)
{
        return ((strcmp(netid, SOCKET_PROTO_TCP6) == 0) ||
            (strcmp(netid, SOCKET_PROTO_UDP6) == 0));
}

/*
 * Registers with rpcbind the program number with all versions, from low to
 * high, with the netid, all specified in 'rpc'. If registration fails,
 * returns -1, else 0.
 */
int
register_rpc_service(const char *fmri, const rpc_info_t *rpc)
{
        struct netconfig        *nconf;
        int                     ver;

        if ((nconf = getnetconfigent(rpc->netid)) == NULL) {
                /*
                 * Check whether getnetconfigent() failed as a result of
                 * having no IPv6 interfaces configured for a v6 netid, or
                 * as a result of a 'real' error, and output an appropriate
                 * message with an appropriate severity.
                 */
                if (is_v6_netid(rpc->netid) && !can_use_af(AF_INET6)) {
                        warn_msg(gettext(
                            "Couldn't register netid %s for RPC instance %s "
                            "because no IPv6 interfaces are plumbed"),
                            rpc->netid, fmri);
                } else {
                        error_msg(gettext(
                            "Failed to lookup netid '%s' for instance %s: %s"),
                            rpc->netid, fmri, nc_sperror());
                }
                return (-1);
        }

        for (ver = rpc->lowver; ver <= rpc->highver; ver++) {
                if (!rpcb_set(rpc->prognum, ver, nconf, &(rpc->netbuf))) {
                        error_msg(gettext("Failed to register version %d "
                            "of RPC service instance %s, netid %s"), ver,
                            fmri, rpc->netid);

                        for (ver--; ver >= rpc->lowver; ver--)
                                (void) rpcb_unset(rpc->prognum, ver, nconf);

                        freenetconfigent(nconf);
                        return (-1);
                }
        }

        freenetconfigent(nconf);
        return (0);
}

/* Unregister all the registrations done by register_rpc_service */
void
unregister_rpc_service(const char *fmri, const rpc_info_t *rpc)
{
        int                     ver;
        struct netconfig        *nconf;

        if ((nconf = getnetconfigent(rpc->netid)) == NULL) {
                /*
                 * Don't output an error message if getnetconfigent() fails for
                 * a v6 netid when an IPv6 interface isn't configured.
                 */
                if (!(is_v6_netid(rpc->netid) && !can_use_af(AF_INET6))) {
                        error_msg(gettext(
                            "Failed to lookup netid '%s' for instance %s: %s"),
                            rpc->netid, fmri, nc_sperror());
                }
                return;
        }

        for (ver = rpc->lowver; ver <= rpc->highver; ver++)
                (void) rpcb_unset(rpc->prognum, ver, nconf);

        freenetconfigent(nconf);
}

/*
 * TLI/XTI functions.
 */

int
tlx_init(void)
{
        if ((conn_ind_pool = uu_list_pool_create("conn_ind_pool",
            sizeof (tlx_conn_ind_t), offsetof(tlx_conn_ind_t, link),
            NULL, UU_LIST_POOL_DEBUG)) == NULL) {
                error_msg("%s: %s", gettext("Failed to create uu pool"),
                    uu_strerror(uu_error()));
                return (-1);
        }

        return (0);
}

void
tlx_fini(void)
{
        if (conn_ind_pool != NULL) {
                uu_list_pool_destroy(conn_ind_pool);
                conn_ind_pool = NULL;
        }
}

/*
 * Checks if the contents of the 2 tlx_info_t structures are equivalent.
 * If 'isrpc' is false, the address components of the two structures are
 * compared for equality as part of this. If the two structures are
 * equivalent B_TRUE is returned, else B_FALSE.
 */
boolean_t
tlx_info_equal(const tlx_info_t *ti, const tlx_info_t *ti2, boolean_t isrpc)
{
        return ((isrpc || (memcmp(ti->local_addr.buf, ti2->local_addr.buf,
            sizeof (struct sockaddr_storage)) == 0)) &&
            (strcmp(ti->dev_name, ti2->dev_name) == 0));
}

/*
 * Attempts to bind an address to the network fd 'fd'. If 'reqaddr' is non-NULL,
 * it attempts to bind to that requested address, else it binds to a kernel
 * selected address. In the former case, the function returning success
 * doesn't guarantee that the requested address was bound (the caller needs to
 * check). If 'retaddr' is non-NULL, the bound address is returned in it. The
 * 'qlen' parameter is used to set the connection backlog. If the bind
 * succeeds 0 is returned, else -1.
 */
static int
tlx_bind(int fd, const struct netbuf *reqaddr, struct netbuf *retaddr, int qlen)
{
        struct t_bind breq;
        struct t_bind bret;

        if (retaddr != NULL) {  /* caller requests bound address be returned */
                bret.addr.buf = retaddr->buf;
                bret.addr.maxlen = retaddr->maxlen;
        }

        if (reqaddr != NULL) {  /* caller requests specific address */
                breq.addr.buf = reqaddr->buf;
                breq.addr.len = reqaddr->len;
        } else {
                breq.addr.len = 0;
        }
        breq.qlen = qlen;

        if (t_bind(fd, &breq, retaddr != NULL ? &bret : NULL) < 0)
                return (-1);

        if (retaddr != NULL)
                retaddr->len = bret.addr.len;

        return (0);
}

static int
tlx_setsockopt(int fd, int level, int optname, const void *optval,
    socklen_t optlen)
{
        struct t_optmgmt request, reply;
        struct {
                struct opthdr sockopt;
                char data[256];
        } optbuf;

        if (optlen > sizeof (optbuf.data)) {
                error_msg(gettext("t_optmgmt request too long"));
                return (-1);
        }

        optbuf.sockopt.level = level;
        optbuf.sockopt.name = optname;
        optbuf.sockopt.len = optlen;
        (void) memcpy(optbuf.data, optval, optlen);

        request.opt.len = sizeof (struct opthdr) + optlen;
        request.opt.buf = (char *)&optbuf;
        request.flags = T_NEGOTIATE;

        reply.opt.maxlen = sizeof (struct opthdr) + optlen;
        reply.opt.buf = (char *)&optbuf;
        reply.flags = 0;

        if ((t_optmgmt(fd, &request, &reply) == -1) ||
            (reply.flags != T_SUCCESS)) {
                error_msg("t_optmgmt: %s", t_strerror(t_errno));
                return (-1);
        }
        return (0);
}

/*
 * Compare contents of netbuf for equality. Return B_TRUE on a match and
 * B_FALSE for mismatch.
 */
static boolean_t
netbufs_equal(struct netbuf *n1, struct netbuf *n2)
{
        return ((n1->len == n2->len) &&
            (memcmp(n1->buf, n2->buf, (size_t)n1->len) == 0));
}

/*
 * Create a tli/xti endpoint, either bound to the address specified in
 * 'instance' for non-RPC services, else a kernel chosen address.
 * Returns -1 on failure, else 0.
 */
int
create_bound_endpoint(const instance_t *inst, tlx_info_t *tlx_info)
{
        int                     fd;
        int                     qlen;
        const char              *fmri = inst->fmri;
        struct netbuf           *reqaddr;
        struct netbuf           *retaddr;
        struct netbuf           netbuf;
        struct sockaddr_storage ss;
        rpc_info_t              *rpc = tlx_info->pr_info.ri;

        if ((fd = t_open(tlx_info->dev_name, O_RDWR, NULL)) == -1) {
                error_msg(gettext("Failed to open transport %s for "
                    "instance %s, proto %s: %s"), tlx_info->dev_name,
                    fmri, tlx_info->pr_info.proto, t_strerror(t_errno));
                return (-1);
        }

        if (tlx_info->pr_info.v6only) {
                int     on = 1;

                /* restrict to IPv6 communications only */
                if (tlx_setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &on,
                    sizeof (on)) == -1) {
                        (void) t_close(fd);
                        return (-1);
                }
        }

        /*
         * Negotiate for the returning of the remote uid for loopback
         * transports for RPC services. This needs to be done before the
         * endpoint is bound using t_bind(), so that any requests to it
         * contain the uid.
         */
        if ((rpc != NULL) && (rpc->is_loopback))
                svc_fd_negotiate_ucred(fd);

        /*
         * Bind the service's address to the endpoint and setup connection
         * backlog. In the case of RPC services, we specify a NULL requested
         * address and accept what we're given, storing the returned address
         * for later RPC binding. In the case of non-RPC services we specify
         * the service's associated address.
         */
        if (rpc != NULL) {
                reqaddr = NULL;
                retaddr =  &(rpc->netbuf);
        } else {
                reqaddr = &(tlx_info->local_addr);
                netbuf.buf = (char *)&ss;
                netbuf.maxlen = sizeof (ss);
                retaddr = &netbuf;
        }

        /* ignored for conn/less services */
        qlen = inst->config->basic->conn_backlog;

        if ((tlx_bind(fd, reqaddr, retaddr, qlen) == -1) ||
            ((reqaddr != NULL) && !netbufs_equal(reqaddr, retaddr))) {
                error_msg(gettext("Failed to bind to the requested address "
                    "for instance %s, proto %s"), fmri,
                    tlx_info->pr_info.proto);
                (void) t_close(fd);
                return (-1);
        }

        return (fd);
}

/*
 * Takes a connection request off 'fd' in the form of a t_call structure
 * and returns a pointer to it.
 * Returns NULL on failure, else pointer to t_call structure on success.
 */
static struct t_call *
get_new_conind(int fd)
{
        struct t_call *call;

        /* LINTED E_BAD_PTR_CAST_ALIGN */
        if ((call = (struct t_call *)t_alloc(fd, T_CALL, T_ALL)) == NULL) {
                error_msg("t_alloc: %s", t_strerror(t_errno));
                return (NULL);
        }
        if (t_listen(fd, call) < 0) {
                error_msg("t_listen: %s", t_strerror(t_errno));
                (void) t_free((char *)call, T_CALL);
                return (NULL);
        }

        return (call);
}

/* Add 'call' to the connection indication queue 'queue'. */
int
queue_conind(uu_list_t *queue, struct t_call *call)
{
        tlx_conn_ind_t *ci;

        if ((ci = malloc(sizeof (tlx_conn_ind_t))) == NULL) {
                error_msg(strerror(errno));
                return (-1);
        }

        ci->call = call;
        uu_list_node_init(ci, &ci->link, conn_ind_pool);
        (void) uu_list_insert_after(queue, NULL, ci);

        return (0);
}

/*
 * Remove and return a pointer to the first call on queue 'queue'. However,
 * if the queue is empty returns NULL.
 */
struct t_call *
dequeue_conind(uu_list_t *queue)
{
        struct t_call   *ret;
        tlx_conn_ind_t  *ci = uu_list_first(queue);

        if (ci == NULL)
                return (NULL);

        ret = ci->call;
        uu_list_remove(queue, ci);
        free(ci);

        return (ret);
}

/*
 * Handle a TLOOK notification received during a t_accept() call.
 * Returns -1 on failure, else 0.
 */
static int
process_tlook(const char *fmri, tlx_info_t *tlx_info)
{
        int     event;
        int     fd = tlx_info->pr_info.listen_fd;

        switch (event = t_look(fd)) {
        case T_LISTEN: {
                struct t_call *call;

                debug_msg("process_tlook: T_LISTEN event");
                if ((call = get_new_conind(fd)) == NULL)
                        return (-1);
                if (queue_conind(tlx_info->conn_ind_queue, call) == -1) {
                        error_msg(gettext("Failed to queue connection "
                            "indication for instance %s"), fmri);
                        (void) t_free((char *)call, T_CALL);
                        return (-1);
                }
                break;
        }
        case T_DISCONNECT: {
                /*
                 * Note: In Solaris 2.X (SunOS 5.X) bundled
                 * connection-oriented transport drivers
                 * [ e.g /dev/tcp and /dev/ticots and
                 * /dev/ticotsord (tl)] we do not send disconnect
                 * indications to listening endpoints.
                 * So this will not be seen with endpoints on Solaris
                 * bundled transport devices. However, Streams TPI
                 * allows for this (broken?) behavior and so we account
                 * for it here because of the possibility of unbundled
                 * transport drivers causing this.
                 */
                tlx_conn_ind_t  *cip;
                struct t_discon *discon;

                debug_msg("process_tlook: T_DISCONNECT event");

                /* LINTED */
                if ((discon = (struct t_discon *)
                    t_alloc(fd, T_DIS, T_ALL)) == NULL) {
                        error_msg("t_alloc: %s", t_strerror(t_errno));
                        return (-1);
                }
                if (t_rcvdis(fd, discon) < 0) {
                        error_msg("t_rcvdis: %s", t_strerror(t_errno));
                        (void) t_free((char *)discon, T_DIS);
                        return (-1);
                }

                /*
                 * Find any queued connection pending that matches this
                 * disconnect notice and remove from the pending queue.
                 */
                cip = uu_list_first(tlx_info->conn_ind_queue);
                while ((cip != NULL) &&
                    (cip->call->sequence != discon->sequence)) {
                        cip = uu_list_next(tlx_info->conn_ind_queue, cip);
                }
                if (cip != NULL) {      /* match found */
                        uu_list_remove(tlx_info->conn_ind_queue, cip);
                        (void) t_free((char *)cip->call, T_CALL);
                        free(cip);
                }

                (void) t_free((char *)discon, T_DIS);
                break;
        }
        case -1:
                error_msg("t_look: %s", t_strerror(t_errno));
                return (-1);
        default:
                error_msg(gettext("do_tlook: unexpected t_look event: %d"),
                    event);
                return (-1);
        }

        return (0);
}

/*
 * This call attempts to t_accept() an incoming/pending TLI connection.
 * If it is thwarted by a TLOOK, it is deferred and whatever is on the
 * file descriptor, removed after a t_look. (Incoming connect indications
 * get queued for later processing and disconnect indications remove a
 * a queued connection request if a match found).
 * Returns -1 on failure, else 0.
 */
int
tlx_accept(const char *fmri, tlx_info_t *tlx_info,
    struct sockaddr_storage *remote_addr)
{
        tlx_conn_ind_t  *conind;
        struct t_call   *call;
        int             fd;
        int             listen_fd = tlx_info->pr_info.listen_fd;

        if ((fd = t_open(tlx_info->dev_name, O_RDWR, NULL)) == -1) {
                error_msg("t_open: %s", t_strerror(t_errno));
                return (-1);
        }

        if (tlx_info->pr_info.v6only) {
                int     on = 1;

                /* restrict to IPv6 communications only */
                if (tlx_setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &on,
                    sizeof (on)) == -1) {
                        (void) t_close(fd);
                        return (-1);
                }
        }

        if (t_bind(fd, NULL, NULL) == -1) {
                error_msg("t_bind: %s", t_strerror(t_errno));
                (void) t_close(fd);
                return (-1);
        }

        /*
         * Get the next connection indication - first try the pending
         * queue, then, if none there, get a new one from the file descriptor.
         */
        if ((conind = uu_list_first(tlx_info->conn_ind_queue)) != NULL) {
                debug_msg("taking con off queue");
                call = conind->call;
        } else if ((call = get_new_conind(listen_fd)) == NULL) {
                (void) t_close(fd);
                return (-1);
        }

        /*
         * Accept the connection indication on the newly created endpoint.
         * If we fail, and it's the result of a tlook, queue the indication
         * if it isn't already, and go and process the t_look.
         */
        if (t_accept(listen_fd, fd, call) == -1) {
                if (t_errno == TLOOK) {
                        if (uu_list_first(tlx_info->conn_ind_queue) == NULL) {
                                /*
                                 * We are first one to have to defer accepting
                                 * and start the pending connections list.
                                 */
                                if (queue_conind(tlx_info->conn_ind_queue,
                                    call) == -1) {
                                        error_msg(gettext(
                                            "Failed to queue connection "
                                            "indication for instance %s"),
                                            fmri);
                                        (void) t_free((char *)call, T_CALL);
                                        return (-1);
                                }
                        }
                        (void) process_tlook(fmri, tlx_info);
                } else {                  /* non-TLOOK accept failure */
                        error_msg("%s: %s", "t_accept failed",
                            t_strerror(t_errno));
                        /*
                         * If we were accepting a queued connection, dequeue
                         * it.
                         */
                        if (uu_list_first(tlx_info->conn_ind_queue) != NULL)
                                (void) dequeue_conind(tlx_info->conn_ind_queue);
                        (void) t_free((char *)call, T_CALL);
                }

                (void) t_close(fd);
                return (-1);
        }

        /* Copy remote address into address parameter */
        (void) memcpy(remote_addr, call->addr.buf,
            MIN(call->addr.len, sizeof (*remote_addr)));

        /* If we were accepting a queued connection, dequeue it. */
        if (uu_list_first(tlx_info->conn_ind_queue) != NULL)
                (void) dequeue_conind(tlx_info->conn_ind_queue);
        (void) t_free((char *)call, T_CALL);

        return (fd);
}

/* protocol independent network fd close routine */
void
close_net_fd(instance_t *inst, int fd)
{
        if (inst->config->basic->istlx) {
                (void) t_close(fd);
        } else {
                (void) close(fd);
        }
}

/*
 * Consume some data from the given endpoint of the given wait-based instance.
 */
void
consume_wait_data(instance_t *inst, int fd)
{
        int     flag;
        char    buf[50];        /* same arbitrary size as old inetd */

        if (inst->config->basic->istlx) {
                (void) t_rcv(fd, buf, sizeof (buf), &flag);
        } else {
                (void) recv(fd, buf, sizeof (buf), 0);
        }
}