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sysv_ipc.c revision 1.20.44.1 
      1 /*	$NetBSD: sysv_ipc.c,v 1.20.44.1 2008/05/16 02:25:27 yamt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998, 2007 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Charles M. Hannum.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: sysv_ipc.c,v 1.20.44.1 2008/05/16 02:25:27 yamt Exp $");
     34 
     35 #include "opt_sysv.h"
     36 
     37 #include <sys/param.h>
     38 #include <sys/kernel.h>
     39 #include <sys/proc.h>
     40 #include <sys/ipc.h>
     41 #ifdef SYSVMSG
     42 #include <sys/msg.h>
     43 #endif
     44 #ifdef SYSVSEM
     45 #include <sys/sem.h>
     46 #endif
     47 #ifdef SYSVSHM
     48 #include <sys/shm.h>
     49 #endif
     50 #include <sys/systm.h>
     51 #include <sys/malloc.h>
     52 #include <sys/mount.h>
     53 #include <sys/vnode.h>
     54 #include <sys/stat.h>
     55 #include <sys/sysctl.h>
     56 #include <sys/kauth.h>
     57 
     58 /*
     59  * Check for ipc permission
     60  */
     61 
     62 int
     63 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode)
     64 {
     65 	mode_t mask;
     66 	int ismember = 0;
     67 
     68 	if (kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, NULL) == 0)
     69 		return (0);
     70 
     71 	if (mode == IPC_M) {
     72 		if (kauth_cred_geteuid(cred) == perm->uid ||
     73 		    kauth_cred_geteuid(cred) == perm->cuid)
     74 			return (0);
     75 		return (EPERM);
     76 	}
     77 
     78 	mask = 0;
     79 
     80 	if (kauth_cred_geteuid(cred) == perm->uid ||
     81 	    kauth_cred_geteuid(cred) == perm->cuid) {
     82 		if (mode & IPC_R)
     83 			mask |= S_IRUSR;
     84 		if (mode & IPC_W)
     85 			mask |= S_IWUSR;
     86 		return ((perm->mode & mask) == mask ? 0 : EACCES);
     87 	}
     88 
     89 	if (kauth_cred_getegid(cred) == perm->gid ||
     90 	    (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) ||
     91 	    kauth_cred_getegid(cred) == perm->cgid ||
     92 	    (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) {
     93 		if (mode & IPC_R)
     94 			mask |= S_IRGRP;
     95 		if (mode & IPC_W)
     96 			mask |= S_IWGRP;
     97 		return ((perm->mode & mask) == mask ? 0 : EACCES);
     98 	}
     99 
    100 	if (mode & IPC_R)
    101 		mask |= S_IROTH;
    102 	if (mode & IPC_W)
    103 		mask |= S_IWOTH;
    104 	return ((perm->mode & mask) == mask ? 0 : EACCES);
    105 }
    106 
    107 /*
    108  * sysctl helper routine for kern.ipc.sysvipc_info subtree.
    109  */
    110 
    111 #define FILL_PERM(src, dst) do { \
    112 	(dst)._key = (src)._key; \
    113 	(dst).uid = (src).uid; \
    114 	(dst).gid = (src).gid; \
    115 	(dst).cuid = (src).cuid; \
    116 	(dst).cgid = (src).cgid; \
    117 	(dst).mode = (src).mode; \
    118 	(dst)._seq = (src)._seq; \
    119 } while (/*CONSTCOND*/ 0);
    120 
    121 #define FILL_MSG(src, dst) do { \
    122 	FILL_PERM((src).msg_perm, (dst).msg_perm); \
    123 	(dst).msg_qnum = (src).msg_qnum; \
    124 	(dst).msg_qbytes = (src).msg_qbytes; \
    125 	(dst)._msg_cbytes = (src)._msg_cbytes; \
    126 	(dst).msg_lspid = (src).msg_lspid; \
    127 	(dst).msg_lrpid = (src).msg_lrpid; \
    128 	(dst).msg_stime = (src).msg_stime; \
    129 	(dst).msg_rtime = (src).msg_rtime; \
    130 	(dst).msg_ctime = (src).msg_ctime; \
    131 } while (/*CONSTCOND*/ 0)
    132 
    133 #define FILL_SEM(src, dst) do { \
    134 	FILL_PERM((src).sem_perm, (dst).sem_perm); \
    135 	(dst).sem_nsems = (src).sem_nsems; \
    136 	(dst).sem_otime = (src).sem_otime; \
    137 	(dst).sem_ctime = (src).sem_ctime; \
    138 } while (/*CONSTCOND*/ 0)
    139 
    140 #define FILL_SHM(src, dst) do { \
    141 	FILL_PERM((src).shm_perm, (dst).shm_perm); \
    142 	(dst).shm_segsz = (src).shm_segsz; \
    143 	(dst).shm_lpid = (src).shm_lpid; \
    144 	(dst).shm_cpid = (src).shm_cpid; \
    145 	(dst).shm_atime = (src).shm_atime; \
    146 	(dst).shm_dtime = (src).shm_dtime; \
    147 	(dst).shm_ctime = (src).shm_ctime; \
    148 	(dst).shm_nattch = (src).shm_nattch; \
    149 } while (/*CONSTCOND*/ 0)
    150 
    151 static int
    152 sysctl_kern_sysvipc(SYSCTLFN_ARGS)
    153 {
    154 	void *where = oldp;
    155 	size_t *sizep = oldlenp;
    156 #ifdef SYSVMSG
    157 	struct msg_sysctl_info *msgsi = NULL;
    158 #endif
    159 #ifdef SYSVSEM
    160 	struct sem_sysctl_info *semsi = NULL;
    161 #endif
    162 #ifdef SYSVSHM
    163 	struct shm_sysctl_info *shmsi = NULL;
    164 #endif
    165 	size_t infosize, dssize, tsize, buflen;
    166 	void *bf = NULL;
    167 	char *start;
    168 	int32_t nds;
    169 	int i, error, ret;
    170 
    171 	if (namelen != 1)
    172 		return EINVAL;
    173 
    174 	start = where;
    175 	buflen = *sizep;
    176 
    177 	switch (*name) {
    178 	case KERN_SYSVIPC_MSG_INFO:
    179 #ifdef SYSVMSG
    180 		infosize = sizeof(msgsi->msginfo);
    181 		nds = msginfo.msgmni;
    182 		dssize = sizeof(msgsi->msgids[0]);
    183 		break;
    184 #else
    185 		return EINVAL;
    186 #endif
    187 	case KERN_SYSVIPC_SEM_INFO:
    188 #ifdef SYSVSEM
    189 		infosize = sizeof(semsi->seminfo);
    190 		nds = seminfo.semmni;
    191 		dssize = sizeof(semsi->semids[0]);
    192 		break;
    193 #else
    194 		return EINVAL;
    195 #endif
    196 	case KERN_SYSVIPC_SHM_INFO:
    197 #ifdef SYSVSHM
    198 		infosize = sizeof(shmsi->shminfo);
    199 		nds = shminfo.shmmni;
    200 		dssize = sizeof(shmsi->shmids[0]);
    201 		break;
    202 #else
    203 		return EINVAL;
    204 #endif
    205 	default:
    206 		return EINVAL;
    207 	}
    208 	/*
    209 	 * Round infosize to 64 bit boundary if requesting more than just
    210 	 * the info structure or getting the total data size.
    211 	 */
    212 	if (where == NULL || *sizep > infosize)
    213 		infosize = roundup(infosize, sizeof(quad_t));
    214 	tsize = infosize + nds * dssize;
    215 
    216 	/* Return just the total size required. */
    217 	if (where == NULL) {
    218 		*sizep = tsize;
    219 		return 0;
    220 	}
    221 
    222 	/* Not enough room for even the info struct. */
    223 	if (buflen < infosize) {
    224 		*sizep = 0;
    225 		return ENOMEM;
    226 	}
    227 	bf = malloc(min(tsize, buflen), M_TEMP, M_WAITOK | M_ZERO);
    228 
    229 	switch (*name) {
    230 #ifdef SYSVMSG
    231 	case KERN_SYSVIPC_MSG_INFO:
    232 		msgsi = (struct msg_sysctl_info *)bf;
    233 		msgsi->msginfo = msginfo;
    234 		break;
    235 #endif
    236 #ifdef SYSVSEM
    237 	case KERN_SYSVIPC_SEM_INFO:
    238 		semsi = (struct sem_sysctl_info *)bf;
    239 		semsi->seminfo = seminfo;
    240 		break;
    241 #endif
    242 #ifdef SYSVSHM
    243 	case KERN_SYSVIPC_SHM_INFO:
    244 		shmsi = (struct shm_sysctl_info *)bf;
    245 		shmsi->shminfo = shminfo;
    246 		break;
    247 #endif
    248 	}
    249 	buflen -= infosize;
    250 
    251 	ret = 0;
    252 	if (buflen > 0) {
    253 		/* Fill in the IPC data structures.  */
    254 		for (i = 0; i < nds; i++) {
    255 			if (buflen < dssize) {
    256 				ret = ENOMEM;
    257 				break;
    258 			}
    259 			switch (*name) {
    260 #ifdef SYSVMSG
    261 			case KERN_SYSVIPC_MSG_INFO:
    262 				mutex_enter(&msgmutex);
    263 				FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]);
    264 				mutex_exit(&msgmutex);
    265 				break;
    266 #endif
    267 #ifdef SYSVSEM
    268 			case KERN_SYSVIPC_SEM_INFO:
    269 				FILL_SEM(sema[i], semsi->semids[i]);
    270 				break;
    271 #endif
    272 #ifdef SYSVSHM
    273 			case KERN_SYSVIPC_SHM_INFO:
    274 				FILL_SHM(shmsegs[i], shmsi->shmids[i]);
    275 				break;
    276 #endif
    277 			}
    278 			buflen -= dssize;
    279 		}
    280 	}
    281 	*sizep -= buflen;
    282 	error = copyout(bf, start, *sizep);
    283 	/* If copyout succeeded, use return code set earlier. */
    284 	if (error == 0)
    285 		error = ret;
    286 	if (bf)
    287 		free(bf, M_TEMP);
    288 	return error;
    289 }
    290 
    291 #undef FILL_PERM
    292 #undef FILL_MSG
    293 #undef FILL_SEM
    294 #undef FILL_SHM
    295 
    296 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup")
    297 {
    298 	sysctl_createv(clog, 0, NULL, NULL,
    299 		CTLFLAG_PERMANENT,
    300 		CTLTYPE_NODE, "kern", NULL,
    301 		NULL, 0, NULL, 0,
    302 		CTL_KERN, CTL_EOL);
    303 
    304 	sysctl_createv(clog, 0, NULL, NULL,
    305 		CTLFLAG_PERMANENT,
    306 		CTLTYPE_NODE, "ipc",
    307 		SYSCTL_DESCR("SysV IPC options"),
    308 		NULL, 0, NULL, 0,
    309 		CTL_KERN, KERN_SYSVIPC, CTL_EOL);
    310 
    311 	sysctl_createv(clog, 0, NULL, NULL,
    312 		CTLFLAG_PERMANENT,
    313 		CTLTYPE_STRUCT, "sysvipc_info",
    314 		SYSCTL_DESCR("System V style IPC information"),
    315 		sysctl_kern_sysvipc, 0, NULL, 0,
    316 		CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL);
    317 }
    318