kernel/net/snmpcom.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  * 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 }