sys-utils/ipcutils.h

   1 /*
   2  * SPDX-License-Identifier: GPL-2.0-or-later
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Copyright (C) 2012 Sami Kerola <kerolasa@iki.fi>
  10  * Copyright (C) 2012-2023 Karel Zak <kzak@redhat.com>
  11  */
  12 #ifndef UTIL_LINUX_IPCUTILS_H
  13 #define UTIL_LINUX_IPCUTILS_H
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <sys/ipc.h>
  18 #include <sys/msg.h>
  19 #include <sys/sem.h>
  20 #include <sys/shm.h>
  21 #include <sys/types.h>
  22 #include <time.h>
  23 #include <unistd.h>
  24 #include <grp.h>
  25 #include <pwd.h>
  26 #include <stdint.h>
  27
  28 /*
  29  * SHM_DEST and SHM_LOCKED are defined in kernel headers, but inside
  30  * #ifdef __KERNEL__ ... #endif
  31  */
  32 #ifndef SHM_DEST
  33   /* shm_mode upper byte flags */
  34 # define SHM_DEST       01000   /* segment will be destroyed on last detach */
  35 # define SHM_LOCKED     02000   /* segment will not be swapped */
  36 #endif
  37
  38 /* For older kernels the same holds for the defines below */
  39 #ifndef MSG_STAT
  40 # define MSG_STAT       11
  41 # define MSG_INFO       12
  42 #endif
  43
  44 #ifndef SHM_STAT
  45 # define SHM_STAT       13
  46 # define SHM_INFO       14
  47 struct shm_info {
  48         int used_ids;
  49         unsigned long shm_tot;          /* total allocated shm */
  50         unsigned long shm_rss;          /* total resident shm */
  51         unsigned long shm_swp;          /* total swapped shm */
  52         unsigned long swap_attempts;
  53         unsigned long swap_successes;
  54 };
  55 #endif
  56
  57 #ifndef SEM_STAT
  58 # define SEM_STAT       18
  59 # define SEM_INFO       19
  60 #endif
  61
  62 /* Some versions of libc only define IPC_INFO when __USE_GNU is defined. */
  63 #ifndef IPC_INFO
  64 # define IPC_INFO       3
  65 #endif
  66
  67 /*
  68  *  * The last arg of semctl is a union semun, but where is it defined? X/OPEN
  69  *   * tells us to define it ourselves, but until recently Linux include files
  70  *    * would also define it.
  71  *     */
  72 #ifndef HAVE_UNION_SEMUN
  73 /* according to X/OPEN we have to define it ourselves */
  74 union semun {
  75         int val;
  76         struct semid_ds *buf;
  77         unsigned short int *array;
  78         struct seminfo *__buf;
  79 };
  80 #endif
  81
  82 /*
  83  * X/OPEN (Jan 1987) does not define fields key, seq in struct ipc_perm;
  84  *      glibc-1.09 has no support for sysv ipc.
  85  *      glibc 2 uses __key, __seq
  86  */
  87 #if defined (__GLIBC__) && __GLIBC__ >= 2
  88 # define KEY __key
  89 #else
  90 # define KEY key
  91 #endif
  92
  93 /* Size printing in ipcs is using these. */
  94 enum {
  95         IPC_UNIT_DEFAULT,
  96         IPC_UNIT_BYTES,
  97         IPC_UNIT_KB,
  98         IPC_UNIT_HUMAN
  99 };
 100
 101 struct ipc_limits {
 102         uint64_t        shmmni;         /* max number of segments */
 103         uint64_t        shmmax;         /* max segment size */
 104         uint64_t        shmall;         /* max total shared memory */
 105         uint64_t        shmmin;         /* min segment size */
 106
 107         int             semmni;         /* max number of arrays */
 108         int             semmsl;         /* max semaphores per array */
 109         int             semmns;         /* max semaphores system wide */
 110         int             semopm;         /* max ops per semop call */
 111         unsigned int    semvmx;         /* semaphore max value (constant) */
 112
 113         int             msgmni;         /* max queues system wide */
 114         uint64_t        msgmax;         /* max size of message */
 115         int             msgmnb;         /* default max size of queue */
 116 };
 117
 118 extern int ipc_msg_get_limits(struct ipc_limits *lim);
 119 extern int ipc_sem_get_limits(struct ipc_limits *lim);
 120 extern int ipc_shm_get_limits(struct ipc_limits *lim);
 121
 122 struct ipc_stat {
 123         int             id;
 124         key_t           key;
 125         uid_t           uid;    /* current uid */
 126         gid_t           gid;    /* current gid */
 127         uid_t           cuid;    /* creator uid */
 128         gid_t           cgid;    /* creator gid */
 129         unsigned int    mode;
 130 };
 131
 132 extern void ipc_print_perms(FILE *f, struct ipc_stat *is);
 133 extern void ipc_print_size(int unit, char *msg, uint64_t size, const char *end, int width);
 134
 135 /* See 'struct shmid_kernel' in kernel sources
 136  */
 137 struct shm_data {
 138         struct ipc_stat shm_perm;
 139
 140         uint64_t        shm_nattch;
 141         uint64_t        shm_segsz;
 142         int64_t         shm_atim;       /* __kernel_time_t is signed long */
 143         int64_t         shm_dtim;
 144         int64_t         shm_ctim;
 145         pid_t           shm_cprid;
 146         pid_t           shm_lprid;
 147         uint64_t        shm_rss;
 148         uint64_t        shm_swp;
 149
 150         struct shm_data  *next;
 151 };
 152
 153 extern int ipc_shm_get_info(int id, struct shm_data **shmds);
 154 extern void ipc_shm_free_info(struct shm_data *shmds);
 155
 156 /* See 'struct sem_array' in kernel sources
 157  */
 158 struct sem_elem {
 159         int     semval;
 160         int     ncount;         /* processes waiting on increase semval */
 161         int     zcount;         /* processes waiting on semval set to zero */
 162         pid_t   pid;            /* process last executed semop(2) call */
 163 };
 164 struct sem_data {
 165         struct ipc_stat sem_perm;
 166
 167         int64_t         sem_ctime;
 168         int64_t         sem_otime;
 169         uint64_t        sem_nsems;
 170
 171         struct sem_elem *elements;
 172         struct sem_data *next;
 173 };
 174
 175 extern int ipc_sem_get_info(int id, struct sem_data **semds);
 176 extern void ipc_sem_free_info(struct sem_data *semds);
 177
 178 /* See 'struct msg_queue' in kernel sources
 179  */
 180 struct msg_data {
 181         struct ipc_stat msg_perm;
 182
 183         int64_t         q_stime;
 184         int64_t         q_rtime;
 185         int64_t         q_ctime;
 186         uint64_t        q_cbytes;
 187         uint64_t        q_qnum;
 188         uint64_t        q_qbytes;
 189         pid_t           q_lspid;
 190         pid_t           q_lrpid;
 191
 192         struct msg_data *next;
 193 };
 194
 195 extern int ipc_msg_get_info(int id, struct msg_data **msgds);
 196 extern void ipc_msg_free_info(struct msg_data *msgds);
 197
 198 #endif /* UTIL_LINUX_IPCUTILS_H */