kernel/net/ip/ip_helper_stream.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #include <sys/types.h>
  28 #include <inet/ip.h>
  29 #include <inet/ip_impl.h>
  30 #include <inet/ipclassifier.h>
  31 #include <inet/proto_set.h>
  32 #include <sys/stream.h>
  33 #include <sys/strsubr.h>
  34 #include <sys/strsun.h>
  35 #include <sys/cmn_err.h>
  36 #include <sys/t_kuser.h>
  37 #include <sys/tihdr.h>
  38 #include <sys/pathname.h>
  39 #include <sys/sockio.h>
  40 #include <sys/vmem.h>
  41 #include <sys/disp.h>
  42
  43 int ip_helper_wput(queue_t *q, mblk_t *mp);
  44
  45 static int ip_helper_stream_close(queue_t *, int, cred_t *);
  46
  47 static struct module_info ip_helper_stream_info =  {
  48         0, "iphelper", IP_MOD_MINPSZ, IP_MOD_MAXPSZ, IP_MOD_HIWAT, IP_MOD_LOWAT
  49 };
  50
  51 static struct qinit ip_helper_stream_rinit = {
  52         NULL, NULL, NULL, ip_helper_stream_close, NULL,
  53         &ip_helper_stream_info, NULL
  54 };
  55
  56 static struct qinit ip_helper_stream_winit = {
  57         ip_helper_wput, ip_wsrv, NULL, NULL, NULL,
  58         &ip_helper_stream_info, NULL, NULL, NULL, STRUIOT_NONE
  59 };
  60
  61 /*
  62  * set the q_ptr of the 'q' to the conn_t pointer passed in
  63  */
  64 static void
  65 ip_helper_share_conn(queue_t *q, mblk_t *mp, cred_t *crp)
  66 {
  67         conn_t *connp = *((conn_t **)mp->b_cont->b_rptr);
  68
  69         /*
  70          * This operation is allowed only on helper streams with kcred
  71          */
  72
  73         if (kcred != crp || msgdsize(mp->b_cont) != sizeof (void *)) {
  74                 miocnak(q, mp, 0, EINVAL);
  75                 return;
  76         }
  77
  78         connp->conn_helper_info->iphs_minfo = q->q_ptr;
  79         connp->conn_helper_info->iphs_rq = RD(q);
  80         connp->conn_helper_info->iphs_wq = WR(q);
  81         WR(q)->q_ptr = RD(q)->q_ptr = (void *)connp;
  82         connp->conn_rq = RD(q);
  83         connp->conn_wq = WR(q);
  84         miocack(q, mp, 0, 0);
  85 }
  86
  87 int
  88 ip_helper_wput(queue_t *q, mblk_t *mp)
  89 {
  90         struct iocblk *iocp = (struct iocblk *)mp->b_rptr;
  91         if (DB_TYPE(mp) == M_IOCTL &&
  92             iocp->ioc_cmd == SIOCSQPTR) {
  93                 ip_helper_share_conn(q, mp, iocp->ioc_cr);
  94         } else {
  95                 /* We only handle ioctl related messages here */
  96                 ASSERT(DB_TYPE(mp) != M_DATA);
  97                 ip_wput_nondata(q, mp);
  98         }
  99         return (0);
 100 }
 101
 102 /* ARGSUSED3 */
 103 int
 104 ip_helper_stream_setup(queue_t *q, dev_t *devp, int flag, int sflag,
 105     cred_t *credp, boolean_t isv6)
 106 {
 107         major_t                 maj;
 108         ip_helper_minfo_t       *ip_minfop;
 109
 110         ASSERT((flag & ~(FKLYR)) == IP_HELPER_STR);
 111
 112         ASSERT(RD(q) == q);
 113
 114         ip_minfop = kmem_alloc(sizeof (ip_helper_minfo_t), KM_SLEEP);
 115         ASSERT(ip_minfop != NULL);
 116
 117         ip_minfop->ip_minfo_dev = 0;
 118         ip_minfop->ip_minfo_arena = NULL;
 119
 120         /*
 121          * Clone the device, allocate minor device number
 122          */
 123         if (ip_minor_arena_la != NULL)
 124                 ip_minfop->ip_minfo_dev = inet_minor_alloc(ip_minor_arena_la);
 125
 126         if (ip_minfop->ip_minfo_dev == 0) {
 127                 /*
 128                  * numbers in the large arena are exhausted
 129                  * Try small arena.
 130                  * Or this is a 32 bit system, 32 bit systems do not have
 131                  * ip_minor_arena_la
 132                  */
 133                 ip_minfop->ip_minfo_dev = inet_minor_alloc(ip_minor_arena_sa);
 134                 if (ip_minfop->ip_minfo_dev == 0) {
 135                         return (EBUSY);
 136                 }
 137                 ip_minfop->ip_minfo_arena = ip_minor_arena_sa;
 138         } else {
 139                 ip_minfop->ip_minfo_arena = ip_minor_arena_la;
 140         }
 141
 142
 143         ASSERT(ip_minfop->ip_minfo_dev != 0);
 144         ASSERT(ip_minfop->ip_minfo_arena != NULL);
 145
 146         RD(q)->q_ptr = WR(q)->q_ptr = ip_minfop;
 147
 148         maj = getemajor(*devp);
 149         *devp = makedevice(maj, (ulong_t)(ip_minfop->ip_minfo_dev));
 150
 151         q->q_qinfo = &ip_helper_stream_rinit;
 152         WR(q)->q_qinfo = &ip_helper_stream_winit;
 153         qprocson(q);
 154         return (0);
 155 }
 156
 157 /* ARGSUSED */
 158 static int
 159 ip_helper_stream_close(queue_t *q, int flag __unused, cred_t *credp __unused)
 160 {
 161         ip_helper_minfo_t *ip_minfop;
 162
 163         qprocsoff(q);
 164         ip_minfop = (q)->q_ptr;
 165         inet_minor_free(ip_minfop->ip_minfo_arena,
 166             ip_minfop->ip_minfo_dev);
 167         kmem_free(ip_minfop, sizeof (ip_helper_minfo_t));
 168         RD(q)->q_ptr = NULL;
 169         WR(q)->q_ptr = NULL;
 170         return (0);
 171 }
 172
 173 /*
 174  * Public interface for creating an IP stream with shared conn_t
 175  * Handles multiple callers in parallel by using conn_lock.
 176  * Note that we allocate the helper stream without any locks, which means
 177  * we might need to free it if we had two threads doing this concurrently
 178  * for the conn_t.
 179  */
 180 int
 181 ip_create_helper_stream(conn_t *connp, ldi_ident_t li)
 182 {
 183         ip_helper_stream_info_t *helper;
 184         int     error;
 185         int     ret;
 186
 187         ASSERT(!servicing_interrupt());
 188
 189         if (connp->conn_helper_info != NULL) {
 190                 /* Already allocated */
 191                 return (0);
 192         }
 193
 194         error = 0;
 195         helper = kmem_alloc(sizeof (ip_helper_stream_info_t), KM_SLEEP);
 196
 197         /*
 198          * open ip device via the layered interface.
 199          * pass in kcred as some threads do not have the
 200          * priviledge to open /dev/ip and the check in
 201          * secpolicy_spec_open() will fail the open
 202          */
 203         error = ldi_open_by_name((connp->conn_family == AF_INET6 ? DEV_IP6 :
 204             DEV_IP), IP_HELPER_STR, kcred, &helper->iphs_handle, li);
 205
 206         if (error != 0) {
 207                 kmem_free(helper, sizeof (ip_helper_stream_info_t));
 208                 return (error);
 209         }
 210         /* Make sure we are the only one */
 211         mutex_enter(&connp->conn_lock);
 212         if (connp->conn_helper_info != NULL) {
 213                 /* Some other thread won - discard this stream */
 214                 mutex_exit(&connp->conn_lock);
 215                 (void) ldi_close(helper->iphs_handle, 0, kcred);
 216                 kmem_free(helper, sizeof (ip_helper_stream_info_t));
 217                 return (0);
 218         }
 219         connp->conn_helper_info = helper;
 220         /*
 221          * Share connp with the helper stream. We hold conn_lock across this
 222          * operation.
 223          */
 224         error = ldi_ioctl(helper->iphs_handle, SIOCSQPTR, (intptr_t)connp,
 225             FKIOCTL, kcred, &ret);
 226
 227         if (error != 0) {
 228                 /*
 229                  * Passing in a zero flag indicates that an error
 230                  * occured and stream was not shared
 231                  */
 232                 (void) ldi_close(helper->iphs_handle, 0, kcred);
 233                 kmem_free(helper, sizeof (ip_helper_stream_info_t));
 234                 connp->conn_helper_info = NULL;
 235         }
 236         mutex_exit(&connp->conn_lock);
 237         return (error);
 238 }
 239
 240 /*
 241  * Public interface for freeing IP helper stream
 242  * Caller must ensure no concurrent use of the conn_t, which is normally
 243  * done by calling this from the close routine when the conn_t is quiesced.
 244  */
 245 void
 246 ip_free_helper_stream(conn_t *connp)
 247 {
 248         ASSERT(!servicing_interrupt());
 249
 250         if (connp->conn_helper_info == NULL)
 251                 return;
 252
 253         ASSERT(connp->conn_helper_info->iphs_handle != NULL);
 254
 255         connp->conn_helper_info->iphs_rq->q_ptr =
 256             connp->conn_helper_info->iphs_wq->q_ptr =
 257             connp->conn_helper_info->iphs_minfo;
 258         (void) ldi_close(connp->conn_helper_info->iphs_handle,
 259             IP_HELPER_STR, kcred);
 260         kmem_free(connp->conn_helper_info, sizeof (ip_helper_stream_info_t));
 261         connp->conn_helper_info = NULL;
 262 }