xref: /illumos-gate/usr/src/uts/common/inet/ip/ip_helper_stream.c (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
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 		 */
131 		ip_minfop->ip_minfo_dev = inet_minor_alloc(ip_minor_arena_sa);
132 		if (ip_minfop->ip_minfo_dev == 0) {
133 			kmem_free(ip_minfop, sizeof (ip_helper_minfo_t));
134 			return (EBUSY);
135 		}
136 		ip_minfop->ip_minfo_arena = ip_minor_arena_sa;
137 	} else {
138 		ip_minfop->ip_minfo_arena = ip_minor_arena_la;
139 	}
140 
141 
142 	ASSERT(ip_minfop->ip_minfo_dev != 0);
143 	ASSERT(ip_minfop->ip_minfo_arena != NULL);
144 
145 	RD(q)->q_ptr = WR(q)->q_ptr = ip_minfop;
146 
147 	maj = getemajor(*devp);
148 	*devp = makedevice(maj, (ulong_t)(ip_minfop->ip_minfo_dev));
149 
150 	q->q_qinfo = &ip_helper_stream_rinit;
151 	WR(q)->q_qinfo = &ip_helper_stream_winit;
152 	qprocson(q);
153 	return (0);
154 }
155 
156 /* ARGSUSED */
157 static int
158 ip_helper_stream_close(queue_t *q, int flag __unused, cred_t *credp __unused)
159 {
160 	ip_helper_minfo_t *ip_minfop;
161 
162 	qprocsoff(q);
163 	ip_minfop = (q)->q_ptr;
164 	inet_minor_free(ip_minfop->ip_minfo_arena,
165 	    ip_minfop->ip_minfo_dev);
166 	kmem_free(ip_minfop, sizeof (ip_helper_minfo_t));
167 	RD(q)->q_ptr = NULL;
168 	WR(q)->q_ptr = NULL;
169 	return (0);
170 }
171 
172 /*
173  * Public interface for creating an IP stream with shared conn_t
174  * Handles multiple callers in parallel by using conn_lock.
175  * Note that we allocate the helper stream without any locks, which means
176  * we might need to free it if we had two threads doing this concurrently
177  * for the conn_t.
178  */
179 int
180 ip_create_helper_stream(conn_t *connp, ldi_ident_t li)
181 {
182 	ip_helper_stream_info_t *helper;
183 	int	error;
184 	int	ret;
185 
186 	ASSERT(!servicing_interrupt());
187 
188 	if (connp->conn_helper_info != NULL) {
189 		/* Already allocated */
190 		return (0);
191 	}
192 
193 	error = 0;
194 	helper = kmem_alloc(sizeof (ip_helper_stream_info_t), KM_SLEEP);
195 
196 	/*
197 	 * open ip device via the layered interface.
198 	 * pass in kcred as some threads do not have the
199 	 * priviledge to open /dev/ip and the check in
200 	 * secpolicy_spec_open() will fail the open
201 	 */
202 	error = ldi_open_by_name((connp->conn_family == AF_INET6 ? DEV_IP6 :
203 	    DEV_IP), IP_HELPER_STR, kcred, &helper->iphs_handle, li);
204 
205 	if (error != 0) {
206 		kmem_free(helper, sizeof (ip_helper_stream_info_t));
207 		return (error);
208 	}
209 	/* Make sure we are the only one */
210 	mutex_enter(&connp->conn_lock);
211 	if (connp->conn_helper_info != NULL) {
212 		/* Some other thread won - discard this stream */
213 		mutex_exit(&connp->conn_lock);
214 		(void) ldi_close(helper->iphs_handle, 0, kcred);
215 		kmem_free(helper, sizeof (ip_helper_stream_info_t));
216 		return (0);
217 	}
218 	connp->conn_helper_info = helper;
219 	/*
220 	 * Share connp with the helper stream. We hold conn_lock across this
221 	 * operation.
222 	 */
223 	error = ldi_ioctl(helper->iphs_handle, SIOCSQPTR, (intptr_t)connp,
224 	    FKIOCTL, kcred, &ret);
225 
226 	if (error != 0) {
227 		/*
228 		 * Passing in a zero flag indicates that an error
229 		 * occured and stream was not shared
230 		 */
231 		(void) ldi_close(helper->iphs_handle, 0, kcred);
232 		kmem_free(helper, sizeof (ip_helper_stream_info_t));
233 		connp->conn_helper_info = NULL;
234 	}
235 	mutex_exit(&connp->conn_lock);
236 	return (error);
237 }
238 
239 /*
240  * Public interface for freeing IP helper stream
241  * Caller must ensure no concurrent use of the conn_t, which is normally
242  * done by calling this from the close routine when the conn_t is quiesced.
243  */
244 void
245 ip_free_helper_stream(conn_t *connp)
246 {
247 	ASSERT(!servicing_interrupt());
248 
249 	if (connp->conn_helper_info == NULL)
250 		return;
251 
252 	ASSERT(connp->conn_helper_info->iphs_handle != NULL);
253 
254 	connp->conn_helper_info->iphs_rq->q_ptr =
255 	    connp->conn_helper_info->iphs_wq->q_ptr =
256 	    connp->conn_helper_info->iphs_minfo;
257 	(void) ldi_close(connp->conn_helper_info->iphs_handle,
258 	    IP_HELPER_STR, kcred);
259 	kmem_free(connp->conn_helper_info, sizeof (ip_helper_stream_info_t));
260 	connp->conn_helper_info = NULL;
261 }
262