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metadata.c
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metadata.c
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/*
* Copyright (C) 2013-2015 Kay Sievers
* Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
* Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
* Copyright (C) 2013-2015 Linux Foundation
* Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
*
* kdbus is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*/
#include <linux/audit.h>
#include <linux/capability.h>
#include <linux/cgroup.h>
#include <linux/cred.h>
#include <linux/file.h>
#include <linux/fs_struct.h>
#include <linux/init.h>
#include <linux/kref.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/uio.h>
#include <linux/user_namespace.h>
#include <linux/version.h>
#include "bus.h"
#include "connection.h"
#include "endpoint.h"
#include "item.h"
#include "message.h"
#include "metadata.h"
#include "names.h"
/**
* struct kdbus_meta_proc - Process metadata
* @kref: Reference counting
* @lock: Object lock
* @collected: Bitmask of collected items
* @valid: Bitmask of collected and valid items
* @uid: UID of process
* @euid: EUID of process
* @suid: SUID of process
* @fsuid: FSUID of process
* @gid: GID of process
* @egid: EGID of process
* @sgid: SGID of process
* @fsgid: FSGID of process
* @pid: PID of process
* @tgid: TGID of process
* @ppid: PPID of process
* @auxgrps: Auxiliary groups
* @n_auxgrps: Number of items in @auxgrps
* @tid_comm: TID comm line
* @pid_comm: PID comm line
* @exe_path: Executable path
* @root_path: Root-FS path
* @cmdline: Command-line
* @cgroup: Full cgroup path
* @caps: Capabilities
* @caps_namespace: User-namespace of @caps
* @seclabel: Seclabel
* @audit_loginuid: Audit login-UID
* @audit_sessionid: Audit session-ID
*/
struct kdbus_meta_proc {
struct kref kref;
struct mutex lock;
u64 collected;
u64 valid;
/* KDBUS_ITEM_CREDS */
kuid_t uid, euid, suid, fsuid;
kgid_t gid, egid, sgid, fsgid;
/* KDBUS_ITEM_PIDS */
struct pid *pid;
struct pid *tgid;
struct pid *ppid;
/* KDBUS_ITEM_AUXGROUPS */
kgid_t *auxgrps;
size_t n_auxgrps;
/* KDBUS_ITEM_TID_COMM */
char tid_comm[TASK_COMM_LEN];
/* KDBUS_ITEM_PID_COMM */
char pid_comm[TASK_COMM_LEN];
/* KDBUS_ITEM_EXE */
struct path exe_path;
struct path root_path;
/* KDBUS_ITEM_CMDLINE */
char *cmdline;
/* KDBUS_ITEM_CGROUP */
char *cgroup;
/* KDBUS_ITEM_CAPS */
struct caps {
/* binary compatible to kdbus_caps */
u32 last_cap;
struct {
u32 caps[_KERNEL_CAPABILITY_U32S];
} set[4];
} caps;
struct user_namespace *caps_namespace;
/* KDBUS_ITEM_SECLABEL */
char *seclabel;
/* KDBUS_ITEM_AUDIT */
kuid_t audit_loginuid;
unsigned int audit_sessionid;
};
/**
* struct kdbus_meta_conn
* @kref: Reference counting
* @lock: Object lock
* @collected: Bitmask of collected items
* @valid: Bitmask of collected and valid items
* @ts: Timestamp values
* @owned_names_items: Serialized items for owned names
* @owned_names_size: Size of @owned_names_items
* @conn_description: Connection description
*/
struct kdbus_meta_conn {
struct kref kref;
struct mutex lock;
u64 collected;
u64 valid;
/* KDBUS_ITEM_TIMESTAMP */
struct kdbus_timestamp ts;
/* KDBUS_ITEM_OWNED_NAME */
struct kdbus_item *owned_names_items;
size_t owned_names_size;
/* KDBUS_ITEM_CONN_DESCRIPTION */
char *conn_description;
};
/**
* kdbus_meta_proc_new() - Create process metadata object
*
* Return: Pointer to new object on success, ERR_PTR on failure.
*/
struct kdbus_meta_proc *kdbus_meta_proc_new(void)
{
struct kdbus_meta_proc *mp;
mp = kzalloc(sizeof(*mp), GFP_KERNEL);
if (!mp)
return ERR_PTR(-ENOMEM);
kref_init(&mp->kref);
mutex_init(&mp->lock);
return mp;
}
static void kdbus_meta_proc_free(struct kref *kref)
{
struct kdbus_meta_proc *mp = container_of(kref, struct kdbus_meta_proc,
kref);
path_put(&mp->exe_path);
path_put(&mp->root_path);
put_user_ns(mp->caps_namespace);
put_pid(mp->ppid);
put_pid(mp->tgid);
put_pid(mp->pid);
kfree(mp->seclabel);
kfree(mp->auxgrps);
kfree(mp->cmdline);
kfree(mp->cgroup);
kfree(mp);
}
/**
* kdbus_meta_proc_ref() - Gain reference
* @mp: Process metadata object
*
* Return: @mp is returned
*/
struct kdbus_meta_proc *kdbus_meta_proc_ref(struct kdbus_meta_proc *mp)
{
if (mp)
kref_get(&mp->kref);
return mp;
}
/**
* kdbus_meta_proc_unref() - Drop reference
* @mp: Process metadata object
*
* Return: NULL
*/
struct kdbus_meta_proc *kdbus_meta_proc_unref(struct kdbus_meta_proc *mp)
{
if (mp)
kref_put(&mp->kref, kdbus_meta_proc_free);
return NULL;
}
static void kdbus_meta_proc_collect_creds(struct kdbus_meta_proc *mp)
{
mp->uid = current_uid();
mp->euid = current_euid();
mp->suid = current_suid();
mp->fsuid = current_fsuid();
mp->gid = current_gid();
mp->egid = current_egid();
mp->sgid = current_sgid();
mp->fsgid = current_fsgid();
mp->valid |= KDBUS_ATTACH_CREDS;
}
static void kdbus_meta_proc_collect_pids(struct kdbus_meta_proc *mp)
{
struct task_struct *parent;
mp->pid = get_pid(task_pid(current));
mp->tgid = get_pid(task_tgid(current));
rcu_read_lock();
parent = rcu_dereference(current->real_parent);
mp->ppid = get_pid(task_tgid(parent));
rcu_read_unlock();
mp->valid |= KDBUS_ATTACH_PIDS;
}
static int kdbus_meta_proc_collect_auxgroups(struct kdbus_meta_proc *mp)
{
struct group_info *info;
size_t i;
info = get_current_groups();
if (info->ngroups > 0) {
mp->auxgrps = kmalloc_array(info->ngroups, sizeof(kgid_t),
GFP_KERNEL);
if (!mp->auxgrps) {
put_group_info(info);
return -ENOMEM;
}
for (i = 0; i < info->ngroups; i++)
mp->auxgrps[i] = GROUP_AT(info, i);
}
mp->n_auxgrps = info->ngroups;
put_group_info(info);
mp->valid |= KDBUS_ATTACH_AUXGROUPS;
return 0;
}
static void kdbus_meta_proc_collect_tid_comm(struct kdbus_meta_proc *mp)
{
get_task_comm(mp->tid_comm, current);
mp->valid |= KDBUS_ATTACH_TID_COMM;
}
static void kdbus_meta_proc_collect_pid_comm(struct kdbus_meta_proc *mp)
{
get_task_comm(mp->pid_comm, current->group_leader);
mp->valid |= KDBUS_ATTACH_PID_COMM;
}
static void kdbus_meta_proc_collect_exe(struct kdbus_meta_proc *mp)
{
struct mm_struct *mm;
mm = get_task_mm(current);
if (!mm)
return;
down_read(&mm->mmap_sem);
if (mm->exe_file) {
mp->exe_path = mm->exe_file->f_path;
path_get(&mp->exe_path);
get_fs_root(current->fs, &mp->root_path);
mp->valid |= KDBUS_ATTACH_EXE;
}
up_read(&mm->mmap_sem);
mmput(mm);
}
static int kdbus_meta_proc_collect_cmdline(struct kdbus_meta_proc *mp)
{
struct mm_struct *mm;
char *cmdline;
mm = get_task_mm(current);
if (!mm)
return 0;
if (!mm->arg_end) {
mmput(mm);
return 0;
}
cmdline = strndup_user((const char __user *)mm->arg_start,
mm->arg_end - mm->arg_start);
mmput(mm);
if (IS_ERR(cmdline))
return PTR_ERR(cmdline);
mp->cmdline = cmdline;
mp->valid |= KDBUS_ATTACH_CMDLINE;
return 0;
}
static int kdbus_meta_proc_collect_cgroup(struct kdbus_meta_proc *mp)
{
#ifdef CONFIG_CGROUPS
void *page;
char *s;
page = (void *)__get_free_page(GFP_TEMPORARY);
if (!page)
return -ENOMEM;
s = task_cgroup_path(current, page, PAGE_SIZE);
if (s) {
mp->cgroup = kstrdup(s, GFP_KERNEL);
if (!mp->cgroup) {
free_page((unsigned long)page);
return -ENOMEM;
}
}
free_page((unsigned long)page);
mp->valid |= KDBUS_ATTACH_CGROUP;
#endif
return 0;
}
static void kdbus_meta_proc_collect_caps(struct kdbus_meta_proc *mp)
{
const struct cred *c = current_cred();
int i;
/* ABI: "last_cap" equals /proc/sys/kernel/cap_last_cap */
mp->caps.last_cap = CAP_LAST_CAP;
mp->caps_namespace = get_user_ns(current_user_ns());
CAP_FOR_EACH_U32(i) {
mp->caps.set[0].caps[i] = c->cap_inheritable.cap[i];
mp->caps.set[1].caps[i] = c->cap_permitted.cap[i];
mp->caps.set[2].caps[i] = c->cap_effective.cap[i];
mp->caps.set[3].caps[i] = c->cap_bset.cap[i];
}
/* clear unused bits */
for (i = 0; i < 4; i++)
mp->caps.set[i].caps[CAP_TO_INDEX(CAP_LAST_CAP)] &=
CAP_LAST_U32_VALID_MASK;
mp->valid |= KDBUS_ATTACH_CAPS;
}
static int kdbus_meta_proc_collect_seclabel(struct kdbus_meta_proc *mp)
{
#ifdef CONFIG_SECURITY
char *ctx = NULL;
u32 sid, len;
int ret;
security_task_getsecid(current, &sid);
ret = security_secid_to_secctx(sid, &ctx, &len);
if (ret < 0) {
/*
* EOPNOTSUPP means no security module is active,
* lets skip adding the seclabel then. This effectively
* drops the SECLABEL item.
*/
return (ret == -EOPNOTSUPP) ? 0 : ret;
}
mp->seclabel = kstrdup(ctx, GFP_KERNEL);
security_release_secctx(ctx, len);
if (!mp->seclabel)
return -ENOMEM;
mp->valid |= KDBUS_ATTACH_SECLABEL;
#endif
return 0;
}
static void kdbus_meta_proc_collect_audit(struct kdbus_meta_proc *mp)
{
#ifdef CONFIG_AUDITSYSCALL
mp->audit_loginuid = audit_get_loginuid(current);
mp->audit_sessionid = audit_get_sessionid(current);
mp->valid |= KDBUS_ATTACH_AUDIT;
#endif
}
/**
* kdbus_meta_proc_collect() - Collect process metadata
* @mp: Process metadata object
* @what: Attach flags to collect
*
* This collects process metadata from current and saves it in @mp.
*
* Return: 0 on success, negative error code on failure.
*/
int kdbus_meta_proc_collect(struct kdbus_meta_proc *mp, u64 what)
{
int ret;
if (!mp || !(what & (KDBUS_ATTACH_CREDS |
KDBUS_ATTACH_PIDS |
KDBUS_ATTACH_AUXGROUPS |
KDBUS_ATTACH_TID_COMM |
KDBUS_ATTACH_PID_COMM |
KDBUS_ATTACH_EXE |
KDBUS_ATTACH_CMDLINE |
KDBUS_ATTACH_CGROUP |
KDBUS_ATTACH_CAPS |
KDBUS_ATTACH_SECLABEL |
KDBUS_ATTACH_AUDIT)))
return 0;
mutex_lock(&mp->lock);
if ((what & KDBUS_ATTACH_CREDS) &&
!(mp->collected & KDBUS_ATTACH_CREDS)) {
kdbus_meta_proc_collect_creds(mp);
mp->collected |= KDBUS_ATTACH_CREDS;
}
if ((what & KDBUS_ATTACH_PIDS) &&
!(mp->collected & KDBUS_ATTACH_PIDS)) {
kdbus_meta_proc_collect_pids(mp);
mp->collected |= KDBUS_ATTACH_PIDS;
}
if ((what & KDBUS_ATTACH_AUXGROUPS) &&
!(mp->collected & KDBUS_ATTACH_AUXGROUPS)) {
ret = kdbus_meta_proc_collect_auxgroups(mp);
if (ret < 0)
goto exit_unlock;
mp->collected |= KDBUS_ATTACH_AUXGROUPS;
}
if ((what & KDBUS_ATTACH_TID_COMM) &&
!(mp->collected & KDBUS_ATTACH_TID_COMM)) {
kdbus_meta_proc_collect_tid_comm(mp);
mp->collected |= KDBUS_ATTACH_TID_COMM;
}
if ((what & KDBUS_ATTACH_PID_COMM) &&
!(mp->collected & KDBUS_ATTACH_PID_COMM)) {
kdbus_meta_proc_collect_pid_comm(mp);
mp->collected |= KDBUS_ATTACH_PID_COMM;
}
if ((what & KDBUS_ATTACH_EXE) &&
!(mp->collected & KDBUS_ATTACH_EXE)) {
kdbus_meta_proc_collect_exe(mp);
mp->collected |= KDBUS_ATTACH_EXE;
}
if ((what & KDBUS_ATTACH_CMDLINE) &&
!(mp->collected & KDBUS_ATTACH_CMDLINE)) {
ret = kdbus_meta_proc_collect_cmdline(mp);
if (ret < 0)
goto exit_unlock;
mp->collected |= KDBUS_ATTACH_CMDLINE;
}
if ((what & KDBUS_ATTACH_CGROUP) &&
!(mp->collected & KDBUS_ATTACH_CGROUP)) {
ret = kdbus_meta_proc_collect_cgroup(mp);
if (ret < 0)
goto exit_unlock;
mp->collected |= KDBUS_ATTACH_CGROUP;
}
if ((what & KDBUS_ATTACH_CAPS) &&
!(mp->collected & KDBUS_ATTACH_CAPS)) {
kdbus_meta_proc_collect_caps(mp);
mp->collected |= KDBUS_ATTACH_CAPS;
}
if ((what & KDBUS_ATTACH_SECLABEL) &&
!(mp->collected & KDBUS_ATTACH_SECLABEL)) {
ret = kdbus_meta_proc_collect_seclabel(mp);
if (ret < 0)
goto exit_unlock;
mp->collected |= KDBUS_ATTACH_SECLABEL;
}
if ((what & KDBUS_ATTACH_AUDIT) &&
!(mp->collected & KDBUS_ATTACH_AUDIT)) {
kdbus_meta_proc_collect_audit(mp);
mp->collected |= KDBUS_ATTACH_AUDIT;
}
ret = 0;
exit_unlock:
mutex_unlock(&mp->lock);
return ret;
}
/**
* kdbus_meta_proc_fake() - Fill process metadata from faked credentials
* @mp: Metadata
* @creds: Creds to set, may be %NULL
* @pids: PIDs to set, may be %NULL
* @seclabel: Seclabel to set, may be %NULL
*
* This function takes information stored in @creds, @pids and @seclabel and
* resolves them to kernel-representations, if possible. A call to this function
* is considered an alternative to calling kdbus_meta_add_current(), which
* derives the same information from the 'current' task.
*
* This call uses the current task's namespaces to resolve the given
* information.
*
* Return: 0 on success, negative error number otherwise.
*/
int kdbus_meta_proc_fake(struct kdbus_meta_proc *mp,
const struct kdbus_creds *creds,
const struct kdbus_pids *pids,
const char *seclabel)
{
int ret;
if (!mp)
return 0;
mutex_lock(&mp->lock);
if (creds && !(mp->collected & KDBUS_ATTACH_CREDS)) {
struct user_namespace *ns = current_user_ns();
mp->uid = make_kuid(ns, creds->uid);
mp->euid = make_kuid(ns, creds->euid);
mp->suid = make_kuid(ns, creds->suid);
mp->fsuid = make_kuid(ns, creds->fsuid);
mp->gid = make_kgid(ns, creds->gid);
mp->egid = make_kgid(ns, creds->egid);
mp->sgid = make_kgid(ns, creds->sgid);
mp->fsgid = make_kgid(ns, creds->fsgid);
if ((creds->uid != (uid_t)-1 && !uid_valid(mp->uid)) ||
(creds->euid != (uid_t)-1 && !uid_valid(mp->euid)) ||
(creds->suid != (uid_t)-1 && !uid_valid(mp->suid)) ||
(creds->fsuid != (uid_t)-1 && !uid_valid(mp->fsuid)) ||
(creds->gid != (gid_t)-1 && !gid_valid(mp->gid)) ||
(creds->egid != (gid_t)-1 && !gid_valid(mp->egid)) ||
(creds->sgid != (gid_t)-1 && !gid_valid(mp->sgid)) ||
(creds->fsgid != (gid_t)-1 && !gid_valid(mp->fsgid))) {
ret = -EINVAL;
goto exit_unlock;
}
mp->valid |= KDBUS_ATTACH_CREDS;
mp->collected |= KDBUS_ATTACH_CREDS;
}
if (pids && !(mp->collected & KDBUS_ATTACH_PIDS)) {
mp->pid = get_pid(find_vpid(pids->tid));
mp->tgid = get_pid(find_vpid(pids->pid));
mp->ppid = get_pid(find_vpid(pids->ppid));
if ((pids->tid != 0 && !mp->pid) ||
(pids->pid != 0 && !mp->tgid) ||
(pids->ppid != 0 && !mp->ppid)) {
put_pid(mp->pid);
put_pid(mp->tgid);
put_pid(mp->ppid);
mp->pid = NULL;
mp->tgid = NULL;
mp->ppid = NULL;
ret = -EINVAL;
goto exit_unlock;
}
mp->valid |= KDBUS_ATTACH_PIDS;
mp->collected |= KDBUS_ATTACH_PIDS;
}
if (seclabel && !(mp->collected & KDBUS_ATTACH_SECLABEL)) {
mp->seclabel = kstrdup(seclabel, GFP_KERNEL);
if (!mp->seclabel) {
ret = -ENOMEM;
goto exit_unlock;
}
mp->valid |= KDBUS_ATTACH_SECLABEL;
mp->collected |= KDBUS_ATTACH_SECLABEL;
}
ret = 0;
exit_unlock:
mutex_unlock(&mp->lock);
return ret;
}
/**
* kdbus_meta_conn_new() - Create connection metadata object
*
* Return: Pointer to new object on success, ERR_PTR on failure.
*/
struct kdbus_meta_conn *kdbus_meta_conn_new(void)
{
struct kdbus_meta_conn *mc;
mc = kzalloc(sizeof(*mc), GFP_KERNEL);
if (!mc)
return ERR_PTR(-ENOMEM);
kref_init(&mc->kref);
mutex_init(&mc->lock);
return mc;
}
static void kdbus_meta_conn_free(struct kref *kref)
{
struct kdbus_meta_conn *mc =
container_of(kref, struct kdbus_meta_conn, kref);
kfree(mc->conn_description);
kfree(mc->owned_names_items);
kfree(mc);
}
/**
* kdbus_meta_conn_ref() - Gain reference
* @mc: Connection metadata object
*/
struct kdbus_meta_conn *kdbus_meta_conn_ref(struct kdbus_meta_conn *mc)
{
if (mc)
kref_get(&mc->kref);
return mc;
}
/**
* kdbus_meta_conn_unref() - Drop reference
* @mc: Connection metadata object
*/
struct kdbus_meta_conn *kdbus_meta_conn_unref(struct kdbus_meta_conn *mc)
{
if (mc)
kref_put(&mc->kref, kdbus_meta_conn_free);
return NULL;
}
static void kdbus_meta_conn_collect_timestamp(struct kdbus_meta_conn *mc,
struct kdbus_kmsg *kmsg)
{
struct timespec ts;
ktime_get_ts(&ts);
mc->ts.monotonic_ns = timespec_to_ns(&ts);
ktime_get_real_ts(&ts);
mc->ts.realtime_ns = timespec_to_ns(&ts);
if (kmsg)
mc->ts.seqnum = kmsg->seq;
mc->valid |= KDBUS_ATTACH_TIMESTAMP;
}
static int kdbus_meta_conn_collect_names(struct kdbus_meta_conn *mc,
struct kdbus_conn *conn)
{
const struct kdbus_name_entry *e;
struct kdbus_item *item;
size_t slen, size;
lockdep_assert_held(&conn->ep->bus->name_registry->rwlock);
size = 0;
list_for_each_entry(e, &conn->names_list, conn_entry)
size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_name) +
strlen(e->name) + 1);
if (!size)
return 0;
item = kmalloc(size, GFP_KERNEL);
if (!item)
return -ENOMEM;
mc->owned_names_items = item;
mc->owned_names_size = size;
list_for_each_entry(e, &conn->names_list, conn_entry) {
slen = strlen(e->name) + 1;
kdbus_item_set(item, KDBUS_ITEM_OWNED_NAME, NULL,
sizeof(struct kdbus_name) + slen);
item->name.flags = e->flags;
memcpy(item->name.name, e->name, slen);
item = KDBUS_ITEM_NEXT(item);
}
/* sanity check: the buffer should be completely written now */
WARN_ON((u8 *)item != (u8 *)mc->owned_names_items + size);
mc->valid |= KDBUS_ATTACH_NAMES;
return 0;
}
static int kdbus_meta_conn_collect_description(struct kdbus_meta_conn *mc,
struct kdbus_conn *conn)
{
if (!conn->description)
return 0;
mc->conn_description = kstrdup(conn->description, GFP_KERNEL);
if (!mc->conn_description)
return -ENOMEM;
mc->valid |= KDBUS_ATTACH_CONN_DESCRIPTION;
return 0;
}
/**
* kdbus_meta_conn_collect() - Collect connection metadata
* @mc: Message metadata object
* @kmsg: Kmsg to collect data from
* @conn: Connection to collect data from
* @what: Attach flags to collect
*
* This collects connection metadata from @kmsg and @conn and saves it in @mc.
*
* If KDBUS_ATTACH_NAMES is set in @what and @conn is non-NULL, the caller must
* hold the name-registry read-lock of conn->ep->bus->registry.
*
* Return: 0 on success, negative error code on failure.
*/
int kdbus_meta_conn_collect(struct kdbus_meta_conn *mc,
struct kdbus_kmsg *kmsg,
struct kdbus_conn *conn,
u64 what)
{
int ret;
if (!mc || !(what & (KDBUS_ATTACH_TIMESTAMP |
KDBUS_ATTACH_NAMES |
KDBUS_ATTACH_CONN_DESCRIPTION)))
return 0;
mutex_lock(&mc->lock);
if (kmsg && (what & KDBUS_ATTACH_TIMESTAMP) &&
!(mc->collected & KDBUS_ATTACH_TIMESTAMP)) {
kdbus_meta_conn_collect_timestamp(mc, kmsg);
mc->collected |= KDBUS_ATTACH_TIMESTAMP;
}
if (conn && (what & KDBUS_ATTACH_NAMES) &&
!(mc->collected & KDBUS_ATTACH_NAMES)) {
ret = kdbus_meta_conn_collect_names(mc, conn);
if (ret < 0)
goto exit_unlock;
mc->collected |= KDBUS_ATTACH_NAMES;
}
if (conn && (what & KDBUS_ATTACH_CONN_DESCRIPTION) &&
!(mc->collected & KDBUS_ATTACH_CONN_DESCRIPTION)) {
ret = kdbus_meta_conn_collect_description(mc, conn);
if (ret < 0)
goto exit_unlock;
mc->collected |= KDBUS_ATTACH_CONN_DESCRIPTION;
}
ret = 0;
exit_unlock:
mutex_unlock(&mc->lock);
return ret;
}
/*
* kdbus_meta_export_prepare() - Prepare metadata for export
* @mp: Process metadata, or NULL
* @mc: Connection metadata, or NULL
* @mask: Pointer to mask of KDBUS_ATTACH_* flags to export
* @sz: Pointer to return the size needed by the metadata
*
* Does a conservative calculation of how much space metadata information
* will take up during export. It is 'conservative' because for string
* translations in namespaces, it will use the kernel namespaces, which is
* the longest possible version.
*
* The actual size consumed by kdbus_meta_export() may hence vary from the
* one reported here, but it is guaranteed never to be greater.
*
* Return: 0 on success, negative error number otherwise.
*/
int kdbus_meta_export_prepare(struct kdbus_meta_proc *mp,
struct kdbus_meta_conn *mc,
u64 *mask, size_t *sz)
{
char *exe_pathname = NULL;
void *exe_page = NULL;
size_t size = 0;
u64 valid = 0;
int ret = 0;
if (mp) {
mutex_lock(&mp->lock);
valid |= mp->valid;
mutex_unlock(&mp->lock);
}
if (mc) {
mutex_lock(&mc->lock);
valid |= mc->valid;
mutex_unlock(&mc->lock);
}
*mask &= valid;
*mask &= kdbus_meta_attach_mask;
if (!*mask)
goto exit;
/* process metadata */
if (mp && (*mask & KDBUS_ATTACH_CREDS))
size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_creds));
if (mp && (*mask & KDBUS_ATTACH_PIDS))
size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_pids));
if (mp && (*mask & KDBUS_ATTACH_AUXGROUPS))
size += KDBUS_ITEM_SIZE(mp->n_auxgrps * sizeof(u32));
if (mp && (*mask & KDBUS_ATTACH_TID_COMM))
size += KDBUS_ITEM_SIZE(strlen(mp->tid_comm) + 1);
if (mp && (*mask & KDBUS_ATTACH_PID_COMM))
size += KDBUS_ITEM_SIZE(strlen(mp->pid_comm) + 1);
if (mp && (*mask & KDBUS_ATTACH_EXE)) {
exe_page = (void *)__get_free_page(GFP_TEMPORARY);
if (!exe_page) {
ret = -ENOMEM;
goto exit;
}
exe_pathname = d_path(&mp->exe_path, exe_page, PAGE_SIZE);
if (IS_ERR(exe_pathname)) {
ret = PTR_ERR(exe_pathname);
goto exit;
}
size += KDBUS_ITEM_SIZE(strlen(exe_pathname) + 1);
free_page((unsigned long)exe_page);
}
if (mp && (*mask & KDBUS_ATTACH_CMDLINE))
size += KDBUS_ITEM_SIZE(strlen(mp->cmdline) + 1);
if (mp && (*mask & KDBUS_ATTACH_CGROUP))
size += KDBUS_ITEM_SIZE(strlen(mp->cgroup) + 1);
if (mp && (*mask & KDBUS_ATTACH_CAPS))
size += KDBUS_ITEM_SIZE(sizeof(mp->caps));
if (mp && (*mask & KDBUS_ATTACH_SECLABEL))
size += KDBUS_ITEM_SIZE(strlen(mp->seclabel) + 1);
if (mp && (*mask & KDBUS_ATTACH_AUDIT))
size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_audit));
/* connection metadata */
if (mc && (*mask & KDBUS_ATTACH_NAMES))
size += mc->owned_names_size;
if (mc && (*mask & KDBUS_ATTACH_CONN_DESCRIPTION))
size += KDBUS_ITEM_SIZE(strlen(mc->conn_description) + 1);
if (mc && (*mask & KDBUS_ATTACH_TIMESTAMP))
size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_timestamp));
exit:
*sz = size;
return ret;
}
static int kdbus_meta_push_kvec(struct kvec *kvec,
struct kdbus_item_header *hdr,
u64 type, void *payload,
size_t payload_size, u64 *size)
{
hdr->type = type;
hdr->size = KDBUS_ITEM_HEADER_SIZE + payload_size;
kdbus_kvec_set(kvec++, hdr, sizeof(*hdr), size);
kdbus_kvec_set(kvec++, payload, payload_size, size);
return 2 + !!kdbus_kvec_pad(kvec++, size);
}
/**
* kdbus_meta_export() - export information from metadata into a slice
* @mp: Process metadata, or NULL
* @mc: Connection metadata, or NULL
* @mask: Mask of KDBUS_ATTACH_* flags to export
* @slice: The slice to export to
* @offset: The offset inside @slice to write to
* @real_size: The real size the metadata consumed
*
* This function exports information from metadata into @slice at offset
* @offset inside that slice. Only information that is requested in @mask
* and that has been collected before is exported.
*
* In order to make sure not to write out of bounds, @mask must be the same
* value that was previously returned from kdbus_meta_export_prepare(). The
* function will, however, not necessarily write as many bytes as returned by
* kdbus_meta_export_prepare(); depending on the namespaces in question, it
* might use up less than that.
*
* All information will be translated using the current namespaces.
*
* Return: 0 on success, negative error number otherwise.
*/
int kdbus_meta_export(struct kdbus_meta_proc *mp,
struct kdbus_meta_conn *mc,
u64 mask,
struct kdbus_pool_slice *slice,
off_t offset,
size_t *real_size)
{
struct user_namespace *user_ns = current_user_ns();
struct kdbus_item_header item_hdr[13], *hdr;
char *exe_pathname = NULL;
struct kdbus_creds creds;
struct kdbus_pids pids;
void *exe_page = NULL;
struct kvec kvec[40];
u32 *auxgrps = NULL;
size_t cnt = 0;
u64 size = 0;
int ret = 0;
hdr = &item_hdr[0];
/*
* TODO: We currently have no sane way of translating a set of caps
* between different user namespaces. Until that changes, we have
* to drop such items.
*/
if (mp && mp->caps_namespace != user_ns)
mask &= ~KDBUS_ATTACH_CAPS;
if (mask == 0) {
*real_size = 0;
return 0;
}
/* process metadata */
if (mp && (mask & KDBUS_ATTACH_CREDS)) {
creds.uid = kdbus_from_kuid_keep(mp->uid);
creds.euid = kdbus_from_kuid_keep(mp->euid);
creds.suid = kdbus_from_kuid_keep(mp->suid);
creds.fsuid = kdbus_from_kuid_keep(mp->fsuid);
creds.gid = kdbus_from_kgid_keep(mp->gid);
creds.egid = kdbus_from_kgid_keep(mp->egid);
creds.sgid = kdbus_from_kgid_keep(mp->sgid);
creds.fsgid = kdbus_from_kgid_keep(mp->fsgid);
cnt += kdbus_meta_push_kvec(kvec + cnt, hdr++, KDBUS_ITEM_CREDS,
&creds, sizeof(creds), &size);
}