C++ GROUP_AT函数代码示例

/* a simple Shell sort */
static void groups_sort(struct group_info *group_info)
{
	int base, max, stride;
	int gidsetsize = group_info->ngroups;

	for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
		; /* nothing */
	stride /= 3;

	while (stride) {
		max = gidsetsize - stride;
		for (base = 0; base < max; base++) {
			int left = base;
			int right = left + stride;
			gid_t tmp = GROUP_AT(group_info, right);

			while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
				GROUP_AT(group_info, right) =
				    GROUP_AT(group_info, left);
				right = left;
				left -= stride;
			}
			GROUP_AT(group_info, right) = tmp;
		}
		stride /= 3;
	}
}

static int
generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
{
	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
	int i;

	if (gcred->acred.uid != acred->uid ||
	    gcred->acred.gid != acred->gid ||
	    gcred->acred.machine_cred != acred->machine_cred)
		goto out_nomatch;

	/* Optimisation in the case where pointers are identical... */
	if (gcred->acred.group_info == acred->group_info)
		goto out_match;

	/* Slow path... */
	if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
		goto out_nomatch;
	for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
		if (GROUP_AT(gcred->acred.group_info, i) !=
				GROUP_AT(acred->group_info, i))
			goto out_nomatch;
	}
out_match:
	return 1;
out_nomatch:
	return 0;
}

static int
generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
{
	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
	int i;

	if (acred->machine_cred)
		return machine_cred_match(acred, gcred, flags);

	if (gcred->acred.uid != acred->uid ||
	    gcred->acred.gid != acred->gid ||
	    gcred->acred.machine_cred != 0)
		goto out_nomatch;

	
	if (gcred->acred.group_info == acred->group_info)
		goto out_match;

	
	if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
		goto out_nomatch;
	for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
		if (GROUP_AT(gcred->acred.group_info, i) !=
				GROUP_AT(acred->group_info, i))
			goto out_nomatch;
	}
out_match:
	return 1;
out_nomatch:
	return 0;
}

cr_groups_search(const struct group_info *group_info, gid_t grp)
#endif
{
	unsigned int left, right, mid;
	int cmp;

	if (!group_info)
		return (0);

	left = 0;
	right = group_info->ngroups;
	while (left < right) {
		mid = (left + right) / 2;
		cmp = KGID_TO_SGID(grp) -
		    KGID_TO_SGID(GROUP_AT(group_info, mid));

		if (cmp > 0)
			left = mid + 1;
		else if (cmp < 0)
			right = mid;
		else
			return (1);
	}
	return (0);
}

static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
                              struct pid *pid, struct task_struct *p)
{
    struct user_namespace *user_ns = seq_user_ns(m);
    struct group_info *group_info;
    int g;
    struct fdtable *fdt = NULL;
    const struct cred *cred;
    pid_t ppid, tpid;

    rcu_read_lock();
    ppid = pid_alive(p) ?
           task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
    tpid = 0;
    if (pid_alive(p)) {
        struct task_struct *tracer = ptrace_parent(p);
        if (tracer)
            tpid = task_pid_nr_ns(tracer, ns);
    }
    cred = get_task_cred(p);
    seq_printf(m,
               "State:\t%s\n"
               "Tgid:\t%d\n"
               "Pid:\t%d\n"
               "PPid:\t%d\n"
               "TracerPid:\t%d\n"
               "Uid:\t%d\t%d\t%d\t%d\n"
               "Gid:\t%d\t%d\t%d\t%d\n",
               get_task_state(p),
               task_tgid_nr_ns(p, ns),
               pid_nr_ns(pid, ns),
               ppid, tpid,
               from_kuid_munged(user_ns, cred->uid),
               from_kuid_munged(user_ns, cred->euid),
               from_kuid_munged(user_ns, cred->suid),
               from_kuid_munged(user_ns, cred->fsuid),
               from_kgid_munged(user_ns, cred->gid),
               from_kgid_munged(user_ns, cred->egid),
               from_kgid_munged(user_ns, cred->sgid),
               from_kgid_munged(user_ns, cred->fsgid));

    task_lock(p);
    if (p->files)
        fdt = files_fdtable(p->files);
    seq_printf(m,
               "FDSize:\t%d\n"
               "Groups:\t",
               fdt ? fdt->max_fds : 0);
    rcu_read_unlock();

    group_info = cred->group_info;
    task_unlock(p);

    for (g = 0; g < group_info->ngroups; g++)
        seq_printf(m, "%d ",
                   from_kgid_munged(user_ns, GROUP_AT(group_info, g)));
    put_cred(cred);

    seq_putc(m, '\n');
}

static struct rpc_cred *
unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
{
	struct unx_cred	*cred;
	unsigned int groups = 0;
	unsigned int i;

	dprintk("RPC:       allocating UNIX cred for uid %d gid %d\n",
			acred->uid, acred->gid);

	if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
		return ERR_PTR(-ENOMEM);

	rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
	cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;

	if (acred->group_info != NULL)
		groups = acred->group_info->ngroups;
	if (groups > NFS_NGROUPS)
		groups = NFS_NGROUPS;

	cred->uc_gid = acred->gid;
	for (i = 0; i < groups; i++)
		cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
	if (i < NFS_NGROUPS)
		cred->uc_gids[i] = NOGROUP;

	return &cred->uc_base;
}

static int gssx_dec_linux_creds(struct xdr_stream *xdr,
				struct svc_cred *creds)
{
	u32 length;
	__be32 *p;
	u32 tmp;
	u32 N;
	int i, err;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		return -ENOSPC;

	length = be32_to_cpup(p);

	if (length > (3 + NGROUPS_MAX) * sizeof(u32))
		return -ENOSPC;

	/* uid */
	err = get_host_u32(xdr, &tmp);
	if (err)
		return err;
	creds->cr_uid = make_kuid(&init_user_ns, tmp);

	/* gid */
	err = get_host_u32(xdr, &tmp);
	if (err)
		return err;
	creds->cr_gid = make_kgid(&init_user_ns, tmp);

	/* number of additional gid's */
	err = get_host_u32(xdr, &tmp);
	if (err)
		return err;
	N = tmp;
	if ((3 + N) * sizeof(u32) != length)
		return -EINVAL;
	creds->cr_group_info = groups_alloc(N);
	if (creds->cr_group_info == NULL)
		return -ENOMEM;

	/* gid's */
	for (i = 0; i < N; i++) {
		kgid_t kgid;
		err = get_host_u32(xdr, &tmp);
		if (err)
			goto out_free_groups;
		err = -EINVAL;
		kgid = make_kgid(&init_user_ns, tmp);
		if (!gid_valid(kgid))
			goto out_free_groups;
		GROUP_AT(creds->cr_group_info, i) = kgid;
	}

	return 0;
out_free_groups:
	groups_free(creds->cr_group_info);
	return err;
}

static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *p)
{
	struct group_info *group_info;
	int g;
	struct fdtable *fdt = NULL;
	const struct cred *cred;
	pid_t ppid, tpid, vpid;

	rcu_read_lock();
	ppid = pid_alive(p) ? ve_task_ppid_nr_ns(p, ns) : 0;

	tpid = 0;
	if (pid_alive(p)) {
		struct task_struct *tracer = tracehook_tracer_task(p);
		if (tracer)
			tpid = task_pid_nr_ns(tracer, ns);
	}
	vpid = task_virtual_pid(p);
	cred = get_task_cred(p);
	seq_printf(m,
		"State:\t%s\n"
		"Tgid:\t%d\n"
		"Pid:\t%d\n"
		"PPid:\t%d\n"
		"TracerPid:\t%d\n"
		"Uid:\t%d\t%d\t%d\t%d\n"
		"Gid:\t%d\t%d\t%d\t%d\n",
		get_task_state(p),
		task_tgid_nr_ns(p, ns),
		pid_nr_ns(pid, ns),
		ppid, tpid,
		cred->uid, cred->euid, cred->suid, cred->fsuid,
		cred->gid, cred->egid, cred->sgid, cred->fsgid);

	task_utrace_proc_status(m, p);

	task_lock(p);
	if (p->files)
		fdt = files_fdtable(p->files);
	seq_printf(m,
		"FDSize:\t%d\n"
		"Groups:\t",
		fdt ? fdt->max_fds : 0);
	rcu_read_unlock();

	group_info = cred->group_info;
	task_unlock(p);

	for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
		seq_printf(m, "%d ", GROUP_AT(group_info, g));
	put_cred(cred);

	seq_printf(m, "\n");

	seq_printf(m, "envID:\t%d\nVPid:\t%d\n",
			p->ve_task_info.owner_env->veid, vpid);
	seq_printf(m, "StopState:\t%u\n", p->stopped_state);
}

/* a simple bsearch */
int groups_search(const struct group_info *group_info, kgid_t grp)
{
	unsigned int left, right;

	if (!group_info)
		return 0;

	left = 0;
	right = group_info->ngroups;
	while (left < right) {
		unsigned int mid = (left+right)/2;
		if (gid_gt(grp, GROUP_AT(group_info, mid)))
			left = mid + 1;
		else if (gid_lt(grp, GROUP_AT(group_info, mid)))
			right = mid;
		else
			return 1;
	}
	return 0;
}

static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info)
{
	int i;
	u16 group;

	for (i = 0; i < group_info->ngroups; i++) {
		group = (u16)GROUP_AT(group_info, i);
		if (put_user(group, grouplist+i))
			return -EFAULT;
	}

	return 0;
}

static int groups16_from_user(struct group_info *group_info, u16 __user *grouplist)
{
	int i;
	u16 group;

	for (i = 0; i < group_info->ngroups; i++) {
		if (get_user(group, grouplist+i))
			return  -EFAULT;
		GROUP_AT(group_info, i) = (gid_t)group;
	}

	return 0;
}

static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *p)
{
	struct group_info *group_info;
	int g;
	struct fdtable *fdt = NULL;
	pid_t ppid, tpid;

	rcu_read_lock();
	ppid = pid_alive(p) ?
		task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
	tpid = 0;
	if (pid_alive(p)) {
		struct task_struct *tracer = tracehook_tracer_task(p);
		if (tracer)
			tpid = task_pid_nr_ns(tracer, ns);
	}
	seq_printf(m,
		"State:\t%s\n"
		"Tgid:\t%d\n"
		"Pid:\t%d\n"
		"PPid:\t%d\n"
		"TracerPid:\t%d\n"
		"Uid:\t%d\t%d\t%d\t%d\n"
		"Gid:\t%d\t%d\t%d\t%d\n",
		get_task_state(p),
		task_tgid_nr_ns(p, ns),
		pid_nr_ns(pid, ns),
		ppid, tpid,
		p->uid, p->euid, p->suid, p->fsuid,
		p->gid, p->egid, p->sgid, p->fsgid);

	task_lock(p);
	if (p->files)
		fdt = files_fdtable(p->files);
	seq_printf(m,
		"FDSize:\t%d\n"
		"Groups:\t",
		fdt ? fdt->max_fds : 0);
	rcu_read_unlock();

	group_info = p->group_info;
	get_group_info(group_info);
	task_unlock(p);

	for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
		seq_printf(m, "%d ", GROUP_AT(group_info, g));
	put_group_info(group_info);

	seq_printf(m, "\n");
}

static int groups16_to_user(old_gid_t __user *grouplist,
    struct group_info *group_info)
{
    int i;
    old_gid_t group;

    for (i = 0; i < group_info->ngroups; i++) {
        group = high2lowgid(GROUP_AT(group_info, i));
        if (put_user(group, grouplist+i))
            return -EFAULT;
    }

    return 0;
}

static int groups16_from_user(struct group_info *group_info,
    old_gid_t __user *grouplist)
{
    int i;
    old_gid_t group;

    for (i = 0; i < group_info->ngroups; i++) {
        if (get_user(group, grouplist+i))
            return  -EFAULT;
        GROUP_AT(group_info, i) = low2highgid(group);
    }

    return 0;
}

/* export the group_info to a user-space array */
static int groups_to_user(gid_t __user *grouplist,
			  const struct group_info *group_info)
{
	struct user_namespace *user_ns = current_user_ns();
	int i;
	unsigned int count = group_info->ngroups;

	for (i = 0; i < count; i++) {
		gid_t gid;
		gid = from_kgid_munged(user_ns, GROUP_AT(group_info, i));
		if (put_user(gid, grouplist+i))
			return -EFAULT;
	}
	return 0;
}