xref: /illumos-gate/usr/src/uts/common/inet/snmpcom.c (revision 66582b606a8194f7f3ba5b3a3a6dca5b0d346361)
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  * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 /* Copyright (c) 1990 Mentat Inc. */
25 
26 /*
27  * This file contains common code for handling Options Management requests
28  * for SNMP/MIB.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/stream.h>
33 #include <sys/stropts.h>
34 #include <sys/errno.h>
35 #define	_SUN_TPI_VERSION 2
36 #include <sys/tihdr.h>
37 #include <sys/ddi.h>
38 #include <sys/cmn_err.h>
39 #include <sys/policy.h>
40 
41 #include <sys/socket.h>
42 #include <netinet/in.h>
43 
44 #include <inet/common.h>
45 #include <inet/mi.h>
46 #include <inet/mib2.h>
47 #include <inet/optcom.h>
48 #include <inet/snmpcom.h>
49 
50 #include <inet/ip.h>
51 #include <sys/brand.h>
52 
53 #define	DEFAULT_LENGTH	sizeof (long)
54 #define	DATA_MBLK_SIZE	1024
55 #define	TOAHDR_SIZE	(sizeof (struct T_optmgmt_ack) +\
56 	sizeof (struct opthdr))
57 
58 /* SNMP Option Request Structure */
59 typedef struct sor_s {
60 	int	sor_group;
61 	int	sor_code;		/* MIB2 index value */
62 	int	sor_size;
63 } sor_t;
64 
65 /*
66  * Validation Table for set requests.
67  */
68 static sor_t	req_arr[] = {
69 	{ MIB2_IP,	1,	sizeof (int)			},
70 	{ MIB2_IP,	2,	sizeof (int)			},
71 	{ MIB2_IP,	21,	sizeof (mib2_ipRouteEntry_t)	},
72 	{ MIB2_IP,	22,	sizeof (mib2_ipNetToMediaEntry_t)},
73 	{ MIB2_TCP,	13,	sizeof (mib2_tcpConnEntry_t)	}
74 };
75 
76 /*
77  * Binary compatibility to what used to be T_CURRENT in older releases.
78  * Unfortunately, the binary chosen for it was different and used by
79  * T_PARTSUCCESS in the new name space. However T_PARTSUCESS is only
80  * anticiapted in new T_OPTMGM_REQ (and not O_T_OPTMGMT_REQ messages).
81  * Only a test for TBADFLAG which uses one of the MIB option levels
82  * may have trouble with this provision for binary compatibility.
83  */
84 #define	OLD_T_CURRENT	0x100	/* same value as T_PARTSUCCESS */
85 
86 /*
87  * MIB info returned in data part of M_PROTO msg.  All info for a single
88  * request is appended in a chain of mblk's off of the M_PROTO T_OPTMGMT_ACK
89  * ctl buffer.
90  */
91 int
92 snmp_append_data(mblk_t *mpdata, char *blob, int len)
93 {
94 
95 	if (!mpdata)
96 		return (0);
97 	while (mpdata->b_cont)
98 		mpdata = mpdata->b_cont;
99 	if (mpdata->b_wptr + len >= mpdata->b_datap->db_lim) {
100 		mpdata->b_cont = allocb(DATA_MBLK_SIZE, BPRI_HI);
101 		mpdata = mpdata->b_cont;
102 		if (!mpdata)
103 			return (0);
104 	}
105 	bcopy(blob, (char *)mpdata->b_wptr, len);
106 	mpdata->b_wptr += len;
107 	return (1);
108 }
109 
110 /*
111  * Need a form which avoids O(n^2) behavior locating the end of the
112  * chain every time.  This is it.
113  */
114 int
115 snmp_append_data2(mblk_t *mpdata, mblk_t **last_mpp, char *blob, int len)
116 {
117 
118 	if (!mpdata)
119 		return (0);
120 	if (*last_mpp == NULL) {
121 		while (mpdata->b_cont)
122 			mpdata = mpdata->b_cont;
123 		*last_mpp = mpdata;
124 	}
125 	if ((*last_mpp)->b_wptr + len >= (*last_mpp)->b_datap->db_lim) {
126 		(*last_mpp)->b_cont = allocb(DATA_MBLK_SIZE, BPRI_HI);
127 		*last_mpp = (*last_mpp)->b_cont;
128 		if (!*last_mpp)
129 			return (0);
130 	}
131 	bcopy(blob, (char *)(*last_mpp)->b_wptr, len);
132 	(*last_mpp)->b_wptr += len;
133 	return (1);
134 }
135 
136 /*
137  * SNMP requests are issued using putmsg() on a stream containing all
138  * relevant modules.  The ctl part contains a O_T_OPTMGMT_REQ message,
139  * and the data part is NULL
140  * to process this msg. If snmpcom_req() returns FALSE, then the module
141  * will try optcom_req to see if its some sort of SOCKET or IP option.
142  * snmpcom_req returns TRUE whenever the first option is recognized as
143  * an SNMP request, even if a bad one.
144  *
145  * "get" is done by a single O_T_OPTMGMT_REQ with MGMT_flags set to T_CURRENT.
146  * All modules respond with one or msg's about what they know.  Responses
147  * are in T_OPTMGMT_ACK format.  The opthdr level/name fields identify what
148  * is begin returned, the len field how big it is (in bytes).  The info
149  * itself is in the data portion of the msg.  Fixed length info returned
150  * in one msg; each table in a separate msg.
151  *
152  * setfn() returns 1 if things ok, 0 if set request invalid or otherwise
153  * messed up.
154  *
155  * If the passed q is at the bottom of the module chain (q_next == NULL,
156  * a ctl msg with req->name, level, len all zero is sent upstream.  This
157  * is and EOD flag to the caller.
158  *
159  * IMPORTANT:
160  * - The msg type is M_PROTO, not M_PCPROTO!!!  This is by design,
161  *   since multiple messages will be sent to stream head and we want
162  *   them queued for reading, not discarded.
163  * - All requests which match a table entry are sent to all get/set functions
164  *   of each module.  The functions must simply ignore requests not meant
165  *   for them: getfn() returns 0, setfn() returns 1.
166  */
167 boolean_t
168 snmpcom_req(queue_t *q, mblk_t *mp, pfi_t setfn, pfi_t getfn, cred_t *credp)
169 {
170 	mblk_t			*mpctl;
171 	struct opthdr		*req;
172 	struct opthdr		*next_req;
173 	struct opthdr		*req_end;
174 	struct opthdr		*req_start;
175 	sor_t			*sreq;
176 	struct T_optmgmt_req	*tor = (struct T_optmgmt_req *)mp->b_rptr;
177 	struct T_optmgmt_ack	*toa;
178 	boolean_t		legacy_req;
179 
180 	if (mp->b_cont) {	/* don't deal with multiple mblk's */
181 		freemsg(mp->b_cont);
182 		mp->b_cont = (mblk_t *)0;
183 		optcom_err_ack(q, mp, TSYSERR, EBADMSG);
184 		return (B_TRUE);
185 	}
186 	if ((mp->b_wptr - mp->b_rptr) < sizeof (struct T_optmgmt_req) ||
187 	    !(req_start = (struct opthdr *)mi_offset_param(mp,
188 	    tor->OPT_offset, tor->OPT_length)))
189 		goto bad_req1;
190 	if (! __TPI_OPT_ISALIGNED(req_start))
191 		goto bad_req1;
192 
193 	/*
194 	 * if first option not in the MIB2 or EXPER range, return false so
195 	 * optcom_req can scope things out.  Otherwise it's passed to each
196 	 * calling module to process or ignore as it sees fit.
197 	 */
198 	if ((!(req_start->level >= MIB2_RANGE_START &&
199 	    req_start->level <= MIB2_RANGE_END)) &&
200 	    (!(req_start->level >= EXPER_RANGE_START &&
201 	    req_start->level <= EXPER_RANGE_END)))
202 		return (B_FALSE);
203 
204 	switch (tor->MGMT_flags) {
205 
206 	case T_NEGOTIATE:
207 		if (secpolicy_ip_config(credp, B_FALSE) != 0) {
208 			optcom_err_ack(q, mp, TACCES, 0);
209 			return (B_TRUE);
210 		}
211 		req_end = (struct opthdr *)((uchar_t *)req_start +
212 		    tor->OPT_length);
213 		for (req = req_start; req < req_end; req = next_req) {
214 			next_req =
215 			    (struct opthdr *)((uchar_t *)&req[1] +
216 			    _TPI_ALIGN_OPT(req->len));
217 			if (next_req > req_end)
218 				goto bad_req2;
219 			for (sreq = req_arr; sreq < A_END(req_arr); sreq++) {
220 				if (req->level == sreq->sor_group &&
221 				    req->name == sreq->sor_code)
222 					break;
223 			}
224 			if (sreq >= A_END(req_arr))
225 				goto bad_req3;
226 			if (!(*setfn)(q, req->level, req->name,
227 			    (uchar_t *)&req[1], req->len))
228 				goto bad_req4;
229 		}
230 		if (q->q_next != NULL)
231 			putnext(q, mp);
232 		else
233 			freemsg(mp);
234 		return (B_TRUE);
235 
236 	case OLD_T_CURRENT:
237 	case T_CURRENT:
238 		mpctl = allocb(TOAHDR_SIZE, BPRI_MED);
239 		if (!mpctl) {
240 			optcom_err_ack(q, mp, TSYSERR, ENOMEM);
241 			return (B_TRUE);
242 		}
243 		mpctl->b_cont = allocb(DATA_MBLK_SIZE, BPRI_MED);
244 		if (!mpctl->b_cont) {
245 			freemsg(mpctl);
246 			optcom_err_ack(q, mp, TSYSERR, ENOMEM);
247 			return (B_TRUE);
248 		}
249 		mpctl->b_datap->db_type = M_PROTO;
250 		mpctl->b_wptr += TOAHDR_SIZE;
251 		toa = (struct T_optmgmt_ack *)mpctl->b_rptr;
252 		toa->PRIM_type = T_OPTMGMT_ACK;
253 		toa->OPT_offset = sizeof (struct T_optmgmt_ack);
254 		toa->OPT_length = sizeof (struct opthdr);
255 		toa->MGMT_flags = T_SUCCESS;
256 		/*
257 		 * If the current process is running inside a solaris10-
258 		 * branded zone and len is 0 then it's a request for
259 		 * legacy data.
260 		 */
261 		if (PROC_IS_BRANDED(curproc) &&
262 		    (strcmp(curproc->p_brand->b_name, "solaris10") == 0) &&
263 		    (req_start->len == 0))
264 			legacy_req = B_TRUE;
265 		else
266 			legacy_req = B_FALSE;
267 		if (!(*getfn)(q, mpctl, req_start->level, legacy_req))
268 			freemsg(mpctl);
269 		/*
270 		 * all data for this module has now been sent upstream.  If
271 		 * this is bottom module of stream, send up an EOD ctl msg,
272 		 * otherwise pass onto the next guy for processing.
273 		 */
274 		if (q->q_next != NULL) {
275 			putnext(q, mp);
276 			return (B_TRUE);
277 		}
278 		if (mp->b_cont) {
279 			freemsg(mp->b_cont);
280 			mp->b_cont = NULL;
281 		}
282 		mpctl = reallocb(mp, TOAHDR_SIZE, 1);
283 		if (!mpctl) {
284 			optcom_err_ack(q, mp, TSYSERR, ENOMEM);
285 			return (B_TRUE);
286 		}
287 		mpctl->b_datap->db_type = M_PROTO;
288 		mpctl->b_wptr = mpctl->b_rptr + TOAHDR_SIZE;
289 		toa = (struct T_optmgmt_ack *)mpctl->b_rptr;
290 		toa->PRIM_type = T_OPTMGMT_ACK;
291 		toa->OPT_offset = sizeof (struct T_optmgmt_ack);
292 		toa->OPT_length = sizeof (struct opthdr);
293 		toa->MGMT_flags = T_SUCCESS;
294 		req = (struct opthdr *)&toa[1];
295 		req->level = 0;
296 		req->name = 0;
297 		req->len = 0;
298 		qreply(q, mpctl);
299 		return (B_TRUE);
300 
301 	default:
302 		optcom_err_ack(q, mp, TBADFLAG, 0);
303 		return (B_TRUE);
304 	}
305 
306 bad_req1:;
307 	printf("snmpcom bad_req1\n");
308 	goto bad_req;
309 bad_req2:;
310 	printf("snmpcom bad_req2\n");
311 	goto bad_req;
312 bad_req3:;
313 	printf("snmpcom bad_req3\n");
314 	goto bad_req;
315 bad_req4:;
316 	printf("snmpcom bad_req4\n");
317 	/* FALLTHRU */
318 bad_req:;
319 	optcom_err_ack(q, mp, TBADOPT, 0);
320 	return (B_TRUE);
321 
322 }
323