usr.bin/ipcs/ipc.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1994 SigmaSoft, Th. Lockert <tholo@sigmasoft.com>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  21  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  27  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  * The split of ipcs.c into ipcs.c and ipc.c to accommodate the
  30  * changes in ipcrm.c was done by Edwin Groothuis <edwin@FreeBSD.org>
  31  */
  32
  33 #include <sys/types.h>
  34 #include <sys/sysctl.h>
  35 #define _WANT_SYSVMSG_INTERNALS
  36 #include <sys/msg.h>
  37 #define _WANT_SYSVSEM_INTERNALS
  38 #include <sys/sem.h>
  39 #define _WANT_SYSVSHM_INTERNALS
  40 #include <sys/shm.h>
  41
  42 #include <assert.h>
  43 #include <err.h>
  44 #include <kvm.h>
  45 #include <nlist.h>
  46 #include <stddef.h>
  47
  48 #include "ipc.h"
  49
  50 int     use_sysctl = 1;
  51 struct semid_kernel     *sema;
  52 struct seminfo          seminfo;
  53 struct msginfo          msginfo;
  54 struct msqid_kernel     *msqids;
  55 struct shminfo          shminfo;
  56 struct shmid_kernel     *shmsegs;
  57
  58 struct nlist symbols[] = {
  59         { .n_name = "sema" },
  60         { .n_name = "seminfo" },
  61         { .n_name = "msginfo" },
  62         { .n_name = "msqids" },
  63         { .n_name = "shminfo" },
  64         { .n_name = "shmsegs" },
  65         { .n_name = NULL }
  66 };
  67
  68 #define SHMINFO_XVEC    X(shmmax, sizeof(u_long))                       \
  69                         X(shmmin, sizeof(u_long))                       \
  70                         X(shmmni, sizeof(u_long))                       \
  71                         X(shmseg, sizeof(u_long))                       \
  72                         X(shmall, sizeof(u_long))
  73
  74 #define SEMINFO_XVEC    X(semmni, sizeof(int))                          \
  75                         X(semmns, sizeof(int))                          \
  76                         X(semmnu, sizeof(int))                          \
  77                         X(semmsl, sizeof(int))                          \
  78                         X(semopm, sizeof(int))                          \
  79                         X(semume, sizeof(int))                          \
  80                         X(semusz, sizeof(int))                          \
  81                         X(semvmx, sizeof(int))                          \
  82                         X(semaem, sizeof(int))
  83
  84 #define MSGINFO_XVEC    X(msgmax, sizeof(int))                          \
  85                         X(msgmni, sizeof(int))                          \
  86                         X(msgmnb, sizeof(int))                          \
  87                         X(msgtql, sizeof(int))                          \
  88                         X(msgssz, sizeof(int))                          \
  89                         X(msgseg, sizeof(int))
  90
  91 #define X(a, b) { "kern.ipc." #a, offsetof(TYPEC, a), (b) },
  92 #define TYPEC   struct shminfo
  93 static struct scgs_vector shminfo_scgsv[] = { SHMINFO_XVEC { .sysctl=NULL } };
  94 #undef  TYPEC
  95 #define TYPEC   struct seminfo
  96 static struct scgs_vector seminfo_scgsv[] = { SEMINFO_XVEC { .sysctl=NULL } };
  97 #undef  TYPEC
  98 #define TYPEC   struct msginfo
  99 static struct scgs_vector msginfo_scgsv[] = { MSGINFO_XVEC { .sysctl=NULL } };
 100 #undef  TYPEC
 101 #undef  X
 102
 103 kvm_t *kd;
 104
 105 void
 106 sysctlgatherstruct(void *addr, size_t size, struct scgs_vector *vecarr)
 107 {
 108         struct scgs_vector *xp;
 109         size_t tsiz;
 110         int rv;
 111
 112         for (xp = vecarr; xp->sysctl != NULL; xp++) {
 113                 assert(xp->offset <= size);
 114                 tsiz = xp->size;
 115                 rv = sysctlbyname(xp->sysctl, (char *)addr + xp->offset,
 116                     &tsiz, NULL, 0);
 117                 if (rv == -1)
 118                         err(1, "sysctlbyname: %s", xp->sysctl);
 119                 if (tsiz != xp->size)
 120                         errx(1, "%s size mismatch (expected %zu, got %zu)",
 121                             xp->sysctl, xp->size, tsiz);
 122         }
 123 }
 124
 125 void
 126 kget(int idx, void *addr, size_t size)
 127 {
 128         const char *symn;               /* symbol name */
 129         size_t tsiz;
 130         int rv;
 131         unsigned long kaddr;
 132         const char *sym2sysctl[] = {    /* symbol to sysctl name table */
 133                 "kern.ipc.sema",
 134                 "kern.ipc.seminfo",
 135                 "kern.ipc.msginfo",
 136                 "kern.ipc.msqids",
 137                 "kern.ipc.shminfo",
 138                 "kern.ipc.shmsegs" };
 139
 140         assert((unsigned)idx <= sizeof(sym2sysctl) / sizeof(*sym2sysctl));
 141         if (!use_sysctl) {
 142                 symn = symbols[idx].n_name;
 143                 if (*symn == '_')
 144                         symn++;
 145                 if (symbols[idx].n_type == 0 || symbols[idx].n_value == 0)
 146                         errx(1, "symbol %s undefined", symn);
 147                 /*
 148                  * For some symbols, the value we retrieve is
 149                  * actually a pointer; since we want the actual value,
 150                  * we have to manually dereference it.
 151                  */
 152                 switch (idx) {
 153                 case X_MSQIDS:
 154                         tsiz = sizeof(msqids);
 155                         rv = kvm_read(kd, symbols[idx].n_value,
 156                             &msqids, tsiz);
 157                         kaddr = (u_long)msqids;
 158                         break;
 159                 case X_SHMSEGS:
 160                         tsiz = sizeof(shmsegs);
 161                         rv = kvm_read(kd, symbols[idx].n_value,
 162                             &shmsegs, tsiz);
 163                         kaddr = (u_long)shmsegs;
 164                         break;
 165                 case X_SEMA:
 166                         tsiz = sizeof(sema);
 167                         rv = kvm_read(kd, symbols[idx].n_value,
 168                             &sema, tsiz);
 169                         kaddr = (u_long)sema;
 170                         break;
 171                 default:
 172                         rv = tsiz = 0;
 173                         kaddr = symbols[idx].n_value;
 174                         break;
 175                 }
 176                 if ((unsigned)rv != tsiz)
 177                         errx(1, "%s: %s", symn, kvm_geterr(kd));
 178                 if ((unsigned)kvm_read(kd, kaddr, addr, size) != size)
 179                         errx(1, "%s: %s", symn, kvm_geterr(kd));
 180         } else {
 181                 switch (idx) {
 182                 case X_SHMINFO:
 183                         sysctlgatherstruct(addr, size, shminfo_scgsv);
 184                         break;
 185                 case X_SEMINFO:
 186                         sysctlgatherstruct(addr, size, seminfo_scgsv);
 187                         break;
 188                 case X_MSGINFO:
 189                         sysctlgatherstruct(addr, size, msginfo_scgsv);
 190                         break;
 191                 default:
 192                         tsiz = size;
 193                         rv = sysctlbyname(sym2sysctl[idx], addr, &tsiz,
 194                             NULL, 0);
 195                         if (rv == -1)
 196                                 err(1, "sysctlbyname: %s", sym2sysctl[idx]);
 197                         if (tsiz != size)
 198                                 errx(1, "%s size mismatch "
 199                                     "(expected %zu, got %zu)",
 200                                     sym2sysctl[idx], size, tsiz);
 201                         break;
 202                 }
 203         }
 204 }