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- #include <linux/mm.h>
- #include <linux/shm.h>
- #include <linux/init.h>
- #include <linux/msg.h>
- #include <linux/vmalloc.h>
- #include <linux/slab.h>
- #include <linux/notifier.h>
- #include <linux/capability.h>
- #include <linux/highuid.h>
- #include <linux/security.h>
- #include <linux/rcupdate.h>
- #include <linux/workqueue.h>
- #include <linux/seq_file.h>
- #include <linux/proc_fs.h>
- #include <linux/audit.h>
- #include <linux/nsproxy.h>
- #include <linux/rwsem.h>
- #include <linux/memory.h>
- #include <linux/ipc_namespace.h>
- #include <linux/rhashtable.h>
- #include <asm/unistd.h>
- #include "util.h"
- struct ipc_proc_iface {
- const char *path;
- const char *header;
- int ids;
- int (*show)(struct seq_file *, void *);
- };
- static int __init ipc_init(void)
- {
- proc_mkdir("sysvipc", NULL);
- sem_init();
- msg_init();
- shm_init();
- return 0;
- }
- device_initcall(ipc_init);
- static const struct rhashtable_params ipc_kht_params = {
- .head_offset = offsetof(struct kern_ipc_perm, khtnode),
- .key_offset = offsetof(struct kern_ipc_perm, key),
- .key_len = FIELD_SIZEOF(struct kern_ipc_perm, key),
- .locks_mul = 1,
- .automatic_shrinking = true,
- };
- void ipc_init_ids(struct ipc_ids *ids)
- {
- ids->in_use = 0;
- ids->seq = 0;
- init_rwsem(&ids->rwsem);
- rhashtable_init(&ids->key_ht, &ipc_kht_params);
- idr_init(&ids->ipcs_idr);
- ids->max_idx = -1;
- #ifdef CONFIG_CHECKPOINT_RESTORE
- ids->next_id = -1;
- #endif
- }
- #ifdef CONFIG_PROC_FS
- static const struct file_operations sysvipc_proc_fops;
- void __init ipc_init_proc_interface(const char *path, const char *header,
- int ids, int (*show)(struct seq_file *, void *))
- {
- struct proc_dir_entry *pde;
- struct ipc_proc_iface *iface;
- iface = kmalloc(sizeof(*iface), GFP_KERNEL);
- if (!iface)
- return;
- iface->path = path;
- iface->header = header;
- iface->ids = ids;
- iface->show = show;
- pde = proc_create_data(path,
- S_IRUGO,
- NULL,
- &sysvipc_proc_fops,
- iface);
- if (!pde)
- kfree(iface);
- }
- #endif
- static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
- {
- struct kern_ipc_perm *ipcp;
- ipcp = rhashtable_lookup_fast(&ids->key_ht, &key,
- ipc_kht_params);
- if (!ipcp)
- return NULL;
- rcu_read_lock();
- ipc_lock_object(ipcp);
- return ipcp;
- }
- static inline int ipc_idr_alloc(struct ipc_ids *ids, struct kern_ipc_perm *new)
- {
- int idx, next_id = -1;
- #ifdef CONFIG_CHECKPOINT_RESTORE
- next_id = ids->next_id;
- ids->next_id = -1;
- #endif
-
- if (next_id < 0) {
- new->seq = ids->seq++;
- if (ids->seq > IPCID_SEQ_MAX)
- ids->seq = 0;
- idx = idr_alloc(&ids->ipcs_idr, new, 0, 0, GFP_NOWAIT);
- } else {
- new->seq = ipcid_to_seqx(next_id);
- idx = idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id),
- 0, GFP_NOWAIT);
- }
- if (idx >= 0)
- new->id = SEQ_MULTIPLIER * new->seq + idx;
- return idx;
- }
- int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int limit)
- {
- kuid_t euid;
- kgid_t egid;
- int idx, err;
-
- refcount_set(&new->refcount, 1);
- if (limit > IPCMNI)
- limit = IPCMNI;
- if (ids->in_use >= limit)
- return -ENOSPC;
- idr_preload(GFP_KERNEL);
- spin_lock_init(&new->lock);
- rcu_read_lock();
- spin_lock(&new->lock);
- current_euid_egid(&euid, &egid);
- new->cuid = new->uid = euid;
- new->gid = new->cgid = egid;
- new->deleted = false;
- idx = ipc_idr_alloc(ids, new);
- idr_preload_end();
- if (idx >= 0 && new->key != IPC_PRIVATE) {
- err = rhashtable_insert_fast(&ids->key_ht, &new->khtnode,
- ipc_kht_params);
- if (err < 0) {
- idr_remove(&ids->ipcs_idr, idx);
- idx = err;
- }
- }
- if (idx < 0) {
- new->deleted = true;
- spin_unlock(&new->lock);
- rcu_read_unlock();
- return idx;
- }
- ids->in_use++;
- if (idx > ids->max_idx)
- ids->max_idx = idx;
- return idx;
- }
- static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
- const struct ipc_ops *ops, struct ipc_params *params)
- {
- int err;
- down_write(&ids->rwsem);
- err = ops->getnew(ns, params);
- up_write(&ids->rwsem);
- return err;
- }
- static int ipc_check_perms(struct ipc_namespace *ns,
- struct kern_ipc_perm *ipcp,
- const struct ipc_ops *ops,
- struct ipc_params *params)
- {
- int err;
- if (ipcperms(ns, ipcp, params->flg))
- err = -EACCES;
- else {
- err = ops->associate(ipcp, params->flg);
- if (!err)
- err = ipcp->id;
- }
- return err;
- }
- static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
- const struct ipc_ops *ops, struct ipc_params *params)
- {
- struct kern_ipc_perm *ipcp;
- int flg = params->flg;
- int err;
-
- down_write(&ids->rwsem);
- ipcp = ipc_findkey(ids, params->key);
- if (ipcp == NULL) {
-
- if (!(flg & IPC_CREAT))
- err = -ENOENT;
- else
- err = ops->getnew(ns, params);
- } else {
-
- if (flg & IPC_CREAT && flg & IPC_EXCL)
- err = -EEXIST;
- else {
- err = 0;
- if (ops->more_checks)
- err = ops->more_checks(ipcp, params);
- if (!err)
-
- err = ipc_check_perms(ns, ipcp, ops, params);
- }
- ipc_unlock(ipcp);
- }
- up_write(&ids->rwsem);
- return err;
- }
- static void ipc_kht_remove(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
- {
- if (ipcp->key != IPC_PRIVATE)
- rhashtable_remove_fast(&ids->key_ht, &ipcp->khtnode,
- ipc_kht_params);
- }
- void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
- {
- int idx = ipcid_to_idx(ipcp->id);
- idr_remove(&ids->ipcs_idr, idx);
- ipc_kht_remove(ids, ipcp);
- ids->in_use--;
- ipcp->deleted = true;
- if (unlikely(idx == ids->max_idx)) {
- do {
- idx--;
- if (idx == -1)
- break;
- } while (!idr_find(&ids->ipcs_idr, idx));
- ids->max_idx = idx;
- }
- }
- void ipc_set_key_private(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
- {
- ipc_kht_remove(ids, ipcp);
- ipcp->key = IPC_PRIVATE;
- }
- bool ipc_rcu_getref(struct kern_ipc_perm *ptr)
- {
- return refcount_inc_not_zero(&ptr->refcount);
- }
- void ipc_rcu_putref(struct kern_ipc_perm *ptr,
- void (*func)(struct rcu_head *head))
- {
- if (!refcount_dec_and_test(&ptr->refcount))
- return;
- call_rcu(&ptr->rcu, func);
- }
- int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
- {
- kuid_t euid = current_euid();
- int requested_mode, granted_mode;
- audit_ipc_obj(ipcp);
- requested_mode = (flag >> 6) | (flag >> 3) | flag;
- granted_mode = ipcp->mode;
- if (uid_eq(euid, ipcp->cuid) ||
- uid_eq(euid, ipcp->uid))
- granted_mode >>= 6;
- else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
- granted_mode >>= 3;
-
- if ((requested_mode & ~granted_mode & 0007) &&
- !ns_capable(ns->user_ns, CAP_IPC_OWNER))
- return -1;
- return security_ipc_permission(ipcp, flag);
- }
- void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
- {
- out->key = in->key;
- out->uid = from_kuid_munged(current_user_ns(), in->uid);
- out->gid = from_kgid_munged(current_user_ns(), in->gid);
- out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
- out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
- out->mode = in->mode;
- out->seq = in->seq;
- }
- void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
- {
- out->key = in->key;
- SET_UID(out->uid, in->uid);
- SET_GID(out->gid, in->gid);
- SET_UID(out->cuid, in->cuid);
- SET_GID(out->cgid, in->cgid);
- out->mode = in->mode;
- out->seq = in->seq;
- }
- struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id)
- {
- struct kern_ipc_perm *out;
- int idx = ipcid_to_idx(id);
- out = idr_find(&ids->ipcs_idr, idx);
- if (!out)
- return ERR_PTR(-EINVAL);
- return out;
- }
- struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
- {
- struct kern_ipc_perm *out = ipc_obtain_object_idr(ids, id);
- if (IS_ERR(out))
- goto out;
- if (ipc_checkid(out, id))
- return ERR_PTR(-EINVAL);
- out:
- return out;
- }
- int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
- const struct ipc_ops *ops, struct ipc_params *params)
- {
- if (params->key == IPC_PRIVATE)
- return ipcget_new(ns, ids, ops, params);
- else
- return ipcget_public(ns, ids, ops, params);
- }
- int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
- {
- kuid_t uid = make_kuid(current_user_ns(), in->uid);
- kgid_t gid = make_kgid(current_user_ns(), in->gid);
- if (!uid_valid(uid) || !gid_valid(gid))
- return -EINVAL;
- out->uid = uid;
- out->gid = gid;
- out->mode = (out->mode & ~S_IRWXUGO)
- | (in->mode & S_IRWXUGO);
- return 0;
- }
- struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns,
- struct ipc_ids *ids, int id, int cmd,
- struct ipc64_perm *perm, int extra_perm)
- {
- kuid_t euid;
- int err = -EPERM;
- struct kern_ipc_perm *ipcp;
- ipcp = ipc_obtain_object_check(ids, id);
- if (IS_ERR(ipcp)) {
- err = PTR_ERR(ipcp);
- goto err;
- }
- audit_ipc_obj(ipcp);
- if (cmd == IPC_SET)
- audit_ipc_set_perm(extra_perm, perm->uid,
- perm->gid, perm->mode);
- euid = current_euid();
- if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
- ns_capable(ns->user_ns, CAP_SYS_ADMIN))
- return ipcp;
- err:
- return ERR_PTR(err);
- }
- #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
- int ipc_parse_version(int *cmd)
- {
- if (*cmd & IPC_64) {
- *cmd ^= IPC_64;
- return IPC_64;
- } else {
- return IPC_OLD;
- }
- }
- #endif
- #ifdef CONFIG_PROC_FS
- struct ipc_proc_iter {
- struct ipc_namespace *ns;
- struct pid_namespace *pid_ns;
- struct ipc_proc_iface *iface;
- };
- struct pid_namespace *ipc_seq_pid_ns(struct seq_file *s)
- {
- struct ipc_proc_iter *iter = s->private;
- return iter->pid_ns;
- }
- static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
- loff_t *new_pos)
- {
- struct kern_ipc_perm *ipc;
- int total, id;
- total = 0;
- for (id = 0; id < pos && total < ids->in_use; id++) {
- ipc = idr_find(&ids->ipcs_idr, id);
- if (ipc != NULL)
- total++;
- }
- if (total >= ids->in_use)
- return NULL;
- for (; pos < IPCMNI; pos++) {
- ipc = idr_find(&ids->ipcs_idr, pos);
- if (ipc != NULL) {
- *new_pos = pos + 1;
- rcu_read_lock();
- ipc_lock_object(ipc);
- return ipc;
- }
- }
-
- return NULL;
- }
- static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
- {
- struct ipc_proc_iter *iter = s->private;
- struct ipc_proc_iface *iface = iter->iface;
- struct kern_ipc_perm *ipc = it;
-
- if (ipc && ipc != SEQ_START_TOKEN)
- ipc_unlock(ipc);
- return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
- }
- static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
- {
- struct ipc_proc_iter *iter = s->private;
- struct ipc_proc_iface *iface = iter->iface;
- struct ipc_ids *ids;
- ids = &iter->ns->ids[iface->ids];
-
- down_read(&ids->rwsem);
-
- if (*pos < 0)
- return NULL;
-
- if (*pos == 0)
- return SEQ_START_TOKEN;
-
- return sysvipc_find_ipc(ids, *pos - 1, pos);
- }
- static void sysvipc_proc_stop(struct seq_file *s, void *it)
- {
- struct kern_ipc_perm *ipc = it;
- struct ipc_proc_iter *iter = s->private;
- struct ipc_proc_iface *iface = iter->iface;
- struct ipc_ids *ids;
-
- if (ipc && ipc != SEQ_START_TOKEN)
- ipc_unlock(ipc);
- ids = &iter->ns->ids[iface->ids];
-
- up_read(&ids->rwsem);
- }
- static int sysvipc_proc_show(struct seq_file *s, void *it)
- {
- struct ipc_proc_iter *iter = s->private;
- struct ipc_proc_iface *iface = iter->iface;
- if (it == SEQ_START_TOKEN) {
- seq_puts(s, iface->header);
- return 0;
- }
- return iface->show(s, it);
- }
- static const struct seq_operations sysvipc_proc_seqops = {
- .start = sysvipc_proc_start,
- .stop = sysvipc_proc_stop,
- .next = sysvipc_proc_next,
- .show = sysvipc_proc_show,
- };
- static int sysvipc_proc_open(struct inode *inode, struct file *file)
- {
- struct ipc_proc_iter *iter;
- iter = __seq_open_private(file, &sysvipc_proc_seqops, sizeof(*iter));
- if (!iter)
- return -ENOMEM;
- iter->iface = PDE_DATA(inode);
- iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
- iter->pid_ns = get_pid_ns(task_active_pid_ns(current));
- return 0;
- }
- static int sysvipc_proc_release(struct inode *inode, struct file *file)
- {
- struct seq_file *seq = file->private_data;
- struct ipc_proc_iter *iter = seq->private;
- put_ipc_ns(iter->ns);
- put_pid_ns(iter->pid_ns);
- return seq_release_private(inode, file);
- }
- static const struct file_operations sysvipc_proc_fops = {
- .open = sysvipc_proc_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = sysvipc_proc_release,
- };
- #endif
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