security/ccsecurity/policy_io.c

/*
 * security/ccsecurity/policy_io.c
 *
 * Copyright (C) 2005-2010  NTT DATA CORPORATION
 *
 * Version: 1.7.2+   2010/06/04
 *
 * This file is applicable to both 2.4.30 and 2.6.11 and later.
 * See README.ccs for ChangeLog.
 *
 */

#include "internal.h"

static struct ccs_profile ccs_default_profile = {
        .learning = &ccs_default_profile.preference,
        .permissive = &ccs_default_profile.preference,
        .enforcing = &ccs_default_profile.preference,
        .audit = &ccs_default_profile.preference,
#ifdef CONFIG_CCSECURITY_AUDIT
        .preference.audit_max_grant_log = CONFIG_CCSECURITY_MAX_GRANT_LOG,
        .preference.audit_max_reject_log = CONFIG_CCSECURITY_MAX_REJECT_LOG,
#endif
        .preference.audit_task_info = true,
        .preference.audit_path_info = true,
        .preference.enforcing_penalty = 0,
        .preference.enforcing_verbose = true,
        .preference.learning_max_entry = CONFIG_CCSECURITY_MAX_ACCEPT_ENTRY,
        .preference.learning_verbose = false,
        .preference.learning_exec_realpath = true,
        .preference.learning_exec_argv0 = true,
        .preference.learning_symlink_target = true,
        .preference.permissive_verbose = true
};

/* Profile version. Currently only 20090903 is defined. */
static unsigned int ccs_profile_version;

/* Profile table. Memory is allocated as needed. */
static struct ccs_profile *ccs_profile_ptr[CCS_MAX_PROFILES];

/* String table for functionality that takes 4 modes. */
static const char *ccs_mode[CCS_CONFIG_MAX_MODE] = {
        [CCS_CONFIG_DISABLED] = "disabled",
        [CCS_CONFIG_LEARNING] = "learning",
        [CCS_CONFIG_PERMISSIVE] = "permissive",
        [CCS_CONFIG_ENFORCING] = "enforcing"
};

/* String table for /proc/ccs/profile */
static const char *ccs_mac_keywords[CCS_MAX_MAC_INDEX +
                                    CCS_MAX_CAPABILITY_INDEX +
                                    CCS_MAX_MAC_CATEGORY_INDEX] = {
        [CCS_MAC_FILE_EXECUTE]
        = "file::execute",
        [CCS_MAC_FILE_OPEN]
        = "file::open",
        [CCS_MAC_FILE_CREATE]
        = "file::create",
        [CCS_MAC_FILE_UNLINK]
        = "file::unlink",
        [CCS_MAC_FILE_MKDIR]
        = "file::mkdir",
        [CCS_MAC_FILE_RMDIR]
        = "file::rmdir",
        [CCS_MAC_FILE_MKFIFO]
        = "file::mkfifo",
        [CCS_MAC_FILE_MKSOCK]
        = "file::mksock",
        [CCS_MAC_FILE_TRUNCATE]
        = "file::truncate",
        [CCS_MAC_FILE_SYMLINK]
        = "file::symlink",
        [CCS_MAC_FILE_REWRITE]
        = "file::rewrite",
        [CCS_MAC_FILE_MKBLOCK]
        = "file::mkblock",
        [CCS_MAC_FILE_MKCHAR]
        = "file::mkchar",
        [CCS_MAC_FILE_LINK]
        = "file::link",
        [CCS_MAC_FILE_RENAME]
        = "file::rename",
        [CCS_MAC_FILE_CHMOD]
        = "file::chmod",
        [CCS_MAC_FILE_CHOWN]
        = "file::chown",
        [CCS_MAC_FILE_CHGRP]
        = "file::chgrp",
        [CCS_MAC_FILE_IOCTL]
        = "file::ioctl",
        [CCS_MAC_FILE_CHROOT]
        = "file::chroot",
        [CCS_MAC_FILE_MOUNT]
        = "file::mount",
        [CCS_MAC_FILE_UMOUNT]
        = "file::umount",
        [CCS_MAC_FILE_PIVOT_ROOT]
        = "file::pivot_root",
        [CCS_MAC_FILE_TRANSIT]
        = "file::transit",
        [CCS_MAC_ENVIRON]
        = "misc::env",
        [CCS_MAC_NETWORK_UDP_BIND]
        = "network::inet_udp_bind",
        [CCS_MAC_NETWORK_UDP_CONNECT]
        = "network::inet_udp_connect",
        [CCS_MAC_NETWORK_TCP_BIND]
        = "network::inet_tcp_bind",
        [CCS_MAC_NETWORK_TCP_LISTEN]
        = "network::inet_tcp_listen",
        [CCS_MAC_NETWORK_TCP_CONNECT]
        = "network::inet_tcp_connect",
        [CCS_MAC_NETWORK_TCP_ACCEPT]
        = "network::inet_tcp_accept",
        [CCS_MAC_NETWORK_RAW_BIND]
        = "network::inet_raw_bind",
        [CCS_MAC_NETWORK_RAW_CONNECT]
        = "network::inet_raw_connect",
        [CCS_MAC_SIGNAL]
        = "ipc::signal",
        [CCS_MAX_MAC_INDEX + CCS_INET_STREAM_SOCKET_CREATE]
        = "capability::inet_tcp_create",
        [CCS_MAX_MAC_INDEX + CCS_INET_STREAM_SOCKET_LISTEN]
        = "capability::inet_tcp_listen",
        [CCS_MAX_MAC_INDEX + CCS_INET_STREAM_SOCKET_CONNECT]
        = "capability::inet_tcp_connect",
        [CCS_MAX_MAC_INDEX + CCS_USE_INET_DGRAM_SOCKET]
        = "capability::use_inet_udp",
        [CCS_MAX_MAC_INDEX + CCS_USE_INET_RAW_SOCKET]
        = "capability::use_inet_ip",
        [CCS_MAX_MAC_INDEX + CCS_USE_ROUTE_SOCKET]
        = "capability::use_route",
        [CCS_MAX_MAC_INDEX + CCS_USE_PACKET_SOCKET]
        = "capability::use_packet",
        [CCS_MAX_MAC_INDEX + CCS_SYS_MOUNT]
        = "capability::SYS_MOUNT",
        [CCS_MAX_MAC_INDEX + CCS_SYS_UMOUNT]
        = "capability::SYS_UMOUNT",
        [CCS_MAX_MAC_INDEX + CCS_SYS_REBOOT]
        = "capability::SYS_REBOOT",
        [CCS_MAX_MAC_INDEX + CCS_SYS_CHROOT]
        = "capability::SYS_CHROOT",
        [CCS_MAX_MAC_INDEX + CCS_SYS_KILL]
        = "capability::SYS_KILL",
        [CCS_MAX_MAC_INDEX + CCS_SYS_VHANGUP]
        = "capability::SYS_VHANGUP",
        [CCS_MAX_MAC_INDEX + CCS_SYS_SETTIME]
        = "capability::SYS_TIME",
        [CCS_MAX_MAC_INDEX + CCS_SYS_NICE]
        = "capability::SYS_NICE",
        [CCS_MAX_MAC_INDEX + CCS_SYS_SETHOSTNAME]
        = "capability::SYS_SETHOSTNAME",
        [CCS_MAX_MAC_INDEX + CCS_USE_KERNEL_MODULE]
        = "capability::use_kernel_module",
        [CCS_MAX_MAC_INDEX + CCS_CREATE_FIFO]
        = "capability::create_fifo",
        [CCS_MAX_MAC_INDEX + CCS_CREATE_BLOCK_DEV]
        = "capability::create_block_dev",
        [CCS_MAX_MAC_INDEX + CCS_CREATE_CHAR_DEV]
        = "capability::create_char_dev",
        [CCS_MAX_MAC_INDEX + CCS_CREATE_UNIX_SOCKET]
        = "capability::create_unix_socket",
        [CCS_MAX_MAC_INDEX + CCS_SYS_LINK]
        = "capability::SYS_LINK",
        [CCS_MAX_MAC_INDEX + CCS_SYS_SYMLINK]
        = "capability::SYS_SYMLINK",
        [CCS_MAX_MAC_INDEX + CCS_SYS_RENAME]
        = "capability::SYS_RENAME",
        [CCS_MAX_MAC_INDEX + CCS_SYS_UNLINK]
        = "capability::SYS_UNLINK",
        [CCS_MAX_MAC_INDEX + CCS_SYS_CHMOD]
        = "capability::SYS_CHMOD",
        [CCS_MAX_MAC_INDEX + CCS_SYS_CHOWN]
        = "capability::SYS_CHOWN",
        [CCS_MAX_MAC_INDEX + CCS_SYS_IOCTL]
        = "capability::SYS_IOCTL",
        [CCS_MAX_MAC_INDEX + CCS_SYS_KEXEC_LOAD]
        = "capability::SYS_KEXEC_LOAD",
        [CCS_MAX_MAC_INDEX + CCS_SYS_PIVOT_ROOT]
        = "capability::SYS_PIVOT_ROOT",
        [CCS_MAX_MAC_INDEX + CCS_SYS_PTRACE]
        = "capability::SYS_PTRACE",
        [CCS_MAX_MAC_INDEX + CCS_CONCEAL_MOUNT]
        = "capability::conceal_mount",
        [CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
         + CCS_MAC_CATEGORY_FILE] = "file",
        [CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
         + CCS_MAC_CATEGORY_NETWORK] = "network",
        [CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
         + CCS_MAC_CATEGORY_MISC] = "misc",
        [CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
         + CCS_MAC_CATEGORY_IPC] = "ipc",
        [CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
         + CCS_MAC_CATEGORY_CAPABILITY] = "capability",
};

/* Permit policy management by non-root user? */
static bool ccs_manage_by_non_root;

/**
 * ccs_cap2keyword - Convert capability operation to capability name.
 *
 * @operation: The capability index.
 *
 * Returns the name of the specified capability's name.
 */
const char *ccs_cap2keyword(const u8 operation)
{
        return operation < CCS_MAX_CAPABILITY_INDEX
                ? ccs_mac_keywords[CCS_MAX_MAC_INDEX + operation] + 12 : NULL;
}

/**
 * ccs_yesno - Return "yes" or "no".
 *
 * @value: Bool value.
 */
static const char *ccs_yesno(const unsigned int value)
{
        return value ? "yes" : "no";
}

/**
 * ccs_io_printf - Transactional printf() to "struct ccs_io_buffer" structure.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @fmt:  The printf()'s format string, followed by parameters.
 *
 * Returns true on success, false otherwise.
 *
 * The snprintf() will truncate, but ccs_io_printf() won't.
 */
bool ccs_io_printf(struct ccs_io_buffer *head, const char *fmt, ...)
{
        va_list args;
        int len;
        int pos = head->read_avail;
        int size = head->readbuf_size - pos;
        if (size <= 0)
                return false;
        va_start(args, fmt);
        len = vsnprintf(head->read_buf + pos, size, fmt, args);
        va_end(args);
        if (pos + len >= head->readbuf_size)
                return false;
        head->read_avail += len;
        return true;
}

/**
 * ccs_assign_profile - Create a new profile.
 *
 * @profile: Profile number to create.
 *
 * Returns pointer to "struct ccs_profile" on success, NULL otherwise.
 */
static struct ccs_profile *ccs_assign_profile(const unsigned int profile)
{
        struct ccs_profile *ptr;
        struct ccs_profile *entry;
        if (profile >= CCS_MAX_PROFILES)
                return NULL;
        ptr = ccs_profile_ptr[profile];
        if (ptr)
                return ptr;
        entry = kzalloc(sizeof(*entry), CCS_GFP_FLAGS);
        if (mutex_lock_interruptible(&ccs_policy_lock))
                goto out;
        ptr = ccs_profile_ptr[profile];
        if (!ptr && ccs_memory_ok(entry, sizeof(*entry))) {
                ptr = entry;
                ptr->audit = &ccs_default_profile.preference;
                ptr->learning = &ccs_default_profile.preference;
                ptr->permissive = &ccs_default_profile.preference;
                ptr->enforcing = &ccs_default_profile.preference;
                ptr->default_config = CCS_CONFIG_DISABLED |
                        CCS_CONFIG_WANT_GRANT_LOG | CCS_CONFIG_WANT_REJECT_LOG;
                memset(ptr->config, CCS_CONFIG_USE_DEFAULT,
                       sizeof(ptr->config));
                mb(); /* Avoid out-of-order execution. */
                ccs_profile_ptr[profile] = ptr;
                entry = NULL;
        }
        mutex_unlock(&ccs_policy_lock);
 out:
        kfree(entry);
        return ptr;
}

/**
 * ccs_check_profile - Check all profiles currently assigned to domains are defined.
 */
static void ccs_check_profile(void)
{
        struct ccs_domain_info *domain;
        const int idx = ccs_read_lock();
        ccs_policy_loaded = true;
        list_for_each_entry_rcu(domain, &ccs_domain_list, list) {
                const u8 profile = domain->profile;
                if (ccs_profile_ptr[profile])
                        continue;
                panic("Profile %u (used by '%s') not defined.\n",
                      profile, domain->domainname->name);
        }
        ccs_read_unlock(idx);
        if (ccs_profile_version != 20090903)
                panic("Profile version %u is not supported.\n",
                      ccs_profile_version);
        printk(KERN_INFO "CCSecurity: 1.7.2+   2010/06/04\n");
        printk(KERN_INFO "Mandatory Access Control activated.\n");
}

/**
 * ccs_profile - Find a profile.
 *
 * @profile: Profile number to find.
 *
 * Returns pointer to "struct ccs_profile".
 */
struct ccs_profile *ccs_profile(const u8 profile)
{
        struct ccs_profile *ptr = ccs_profile_ptr[profile];
        if (!ccs_policy_loaded)
                return &ccs_default_profile;
        BUG_ON(!ptr);
        return ptr;
}

static s8 ccs_find_yesno(const char *string, const char *find)
{
        const char *cp = strstr(string, find);
        if (cp) {
                cp += strlen(find);
                if (!strncmp(cp, "=yes", 4))
                        return 1;
                else if (!strncmp(cp, "=no", 3))
                        return 0;
        }
        return -1;
}

static void ccs_set_bool(bool *b, const char *string, const char *find)
{
        switch (ccs_find_yesno(string, find)) {
        case 1:
                *b = true;
                break;
        case 0:
                *b = false;
                break;
        }
}

static void ccs_set_uint(unsigned int *i, const char *string, const char *find)
{
        const char *cp = strstr(string, find);
        if (cp)
                sscanf(cp + strlen(find), "=%u", i);
}

static void ccs_set_pref(const char *name, const char *value,
                         const bool use_default, struct ccs_profile *profile)
{
        struct ccs_preference **pref;
        bool *verbose;
        if (!strcmp(name, "audit")) {
                if (use_default) {
                        pref = &profile->audit;
                        goto set_default;
                }
                profile->audit = &profile->preference;
#ifdef CONFIG_CCSECURITY_AUDIT
                ccs_set_uint(&profile->preference.audit_max_grant_log, value,
                             "max_grant_log");
                ccs_set_uint(&profile->preference.audit_max_reject_log, value,
                             "max_reject_log");
#endif
                ccs_set_bool(&profile->preference.audit_task_info, value,
                             "task_info");
                ccs_set_bool(&profile->preference.audit_path_info, value,
                             "path_info");
                return;
        }
        if (!strcmp(name, "enforcing")) {
                if (use_default) {
                        pref = &profile->enforcing;
                        goto set_default;
                }
                profile->enforcing = &profile->preference;
                ccs_set_uint(&profile->preference.enforcing_penalty, value,
                             "penalty");
                verbose = &profile->preference.enforcing_verbose;
                goto set_verbose;
        }
        if (!strcmp(name, "permissive")) {
                if (use_default) {
                        pref = &profile->permissive;
                        goto set_default;
                }
                profile->permissive = &profile->preference;
                verbose = &profile->preference.permissive_verbose;
                goto set_verbose;
        }
        if (!strcmp(name, "learning")) {
                if (use_default) {
                        pref = &profile->learning;
                        goto set_default;
                }
                profile->learning = &profile->preference;
                ccs_set_uint(&profile->preference.learning_max_entry, value,
                             "max_entry");
                ccs_set_bool(&profile->preference.learning_exec_realpath,
                             value, "exec.realpath");
                ccs_set_bool(&profile->preference.learning_exec_argv0, value,
                             "exec.argv0");
                ccs_set_bool(&profile->preference.learning_symlink_target,
                             value, "symlink.target");
                verbose = &profile->preference.learning_verbose;
                goto set_verbose;
        }
        return;
 set_default:
        *pref = &ccs_default_profile.preference;
        return;
 set_verbose:
        ccs_set_bool(verbose, value, "verbose");
}

static int ccs_set_mode(char *name, const char *value, const bool use_default,
                        struct ccs_profile *profile)
{
        u8 i;
        u8 config;
        if (!strcmp(name, "CONFIG")) {
                i = CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
                        + CCS_MAX_MAC_CATEGORY_INDEX;
                config = profile->default_config;
        } else if (ccs_str_starts(&name, "CONFIG::")) {
                config = 0;
                for (i = 0; i < CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
                             + CCS_MAX_MAC_CATEGORY_INDEX; i++) {
                        if (strcmp(name, ccs_mac_keywords[i]))
                                continue;
                        config = profile->config[i];
                        break;
                }
                if (i == CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
                    + CCS_MAX_MAC_CATEGORY_INDEX)
                        return -EINVAL;
        } else {
                return -EINVAL;
        }
        if (use_default) {
                config = CCS_CONFIG_USE_DEFAULT;
        } else {
                u8 mode;
                for (mode = 0; mode < CCS_CONFIG_MAX_MODE; mode++)
                        if (strstr(value, ccs_mode[mode]))
                                /*
                                 * Update lower 3 bits in order to distinguish
                                 * 'config' from 'CCS_CONFIG_USE_DEAFULT'.
                                 */
                                config = (config & ~7) | mode;
#ifdef CONFIG_CCSECURITY_AUDIT
                if (config != CCS_CONFIG_USE_DEFAULT) {
                        switch (ccs_find_yesno(value, "grant_log")) {
                        case 1:
                                config |= CCS_CONFIG_WANT_GRANT_LOG;
                                break;
                        case 0:
                                config &= ~CCS_CONFIG_WANT_GRANT_LOG;
                                break;
                        }
                        switch (ccs_find_yesno(value, "reject_log")) {
                        case 1:
                                config |= CCS_CONFIG_WANT_REJECT_LOG;
                                break;
                        case 0:
                                config &= ~CCS_CONFIG_WANT_REJECT_LOG;
                                break;
                        }
                }
#endif
        }
        if (i < CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
            + CCS_MAX_MAC_CATEGORY_INDEX)
                profile->config[i] = config;
        else if (config != CCS_CONFIG_USE_DEFAULT)
                profile->default_config = config;
        return 0;
}

/**
 * ccs_write_profile - Write profile table.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int ccs_write_profile(struct ccs_io_buffer *head)
{
        char *data = head->write_buf;
        bool use_default = false;
        char *cp;
        int i;
        struct ccs_profile *profile;
        if (sscanf(data, "PROFILE_VERSION=%u", &ccs_profile_version) == 1)
                return 0;
        i = simple_strtoul(data, &cp, 10);
        if (data == cp) {
                profile = &ccs_default_profile;
        } else {
                if (*cp != '-')
                        return -EINVAL;
                data = cp + 1;
                profile = ccs_assign_profile(i);
                if (!profile)
                        return -EINVAL;
        }
        cp = strchr(data, '=');
        if (!cp)
                return -EINVAL;
        *cp++ = '\0';
        if (profile != &ccs_default_profile)
                use_default = strstr(cp, "use_default") != NULL;
        if (ccs_str_starts(&data, "PREFERENCE::")) {
                ccs_set_pref(data, cp, use_default, profile);
                return 0;
        }
        if (profile == &ccs_default_profile)
                return -EINVAL;
        if (!strcmp(data, "COMMENT")) {
                const struct ccs_path_info *old_comment = profile->comment;
                profile->comment = ccs_get_name(cp);
                ccs_put_name(old_comment);
                return 0;
        }
        return ccs_set_mode(data, cp, use_default, profile);
}

static bool ccs_print_preference(struct ccs_io_buffer *head, const int idx)
{
        struct ccs_preference *pref = &ccs_default_profile.preference;
        const struct ccs_profile *profile = idx >= 0 ?
                ccs_profile_ptr[idx] : NULL;
        char buffer[16] = "";
        if (profile) {
                buffer[sizeof(buffer) - 1] = '\0';
                snprintf(buffer, sizeof(buffer) - 1, "%u-", idx);
        }
        if (profile) {
                pref = profile->audit;
                if (pref == &ccs_default_profile.preference)
                        pref = NULL;
        }
        if (pref && !ccs_io_printf(head, "%sPREFERENCE::%s={ "
#ifdef CONFIG_CCSECURITY_AUDIT
                                   "max_grant_log=%u max_reject_log=%u "
#endif
                                   "task_info=%s path_info=%s }\n", buffer,
                                   "audit",
#ifdef CONFIG_CCSECURITY_AUDIT
                                   pref->audit_max_grant_log,
                                   pref->audit_max_reject_log,
#endif
                                   ccs_yesno(pref->audit_task_info),
                                   ccs_yesno(pref->audit_path_info)))
                return false;
        if (profile) {
                pref = profile->learning;
                if (pref == &ccs_default_profile.preference)
                        pref = NULL;
        }
        if (pref && !ccs_io_printf(head, "%sPREFERENCE::%s={ "
                                   "verbose=%s max_entry=%u exec.realpath=%s "
                                   "exec.argv0=%s symlink.target=%s }\n",
                                   buffer, "learning",
                                   ccs_yesno(pref->learning_verbose),
                                   pref->learning_max_entry,
                                   ccs_yesno(pref->learning_exec_realpath),
                                   ccs_yesno(pref->learning_exec_argv0),
                                   ccs_yesno(pref->learning_symlink_target)))
                return false;
        if (profile) {
                pref = profile->permissive;
                if (pref == &ccs_default_profile.preference)
                        pref = NULL;
        }
        if (pref && !ccs_io_printf(head, "%sPREFERENCE::%s={ verbose=%s }\n",
                                   buffer, "permissive",
                                   ccs_yesno(pref->permissive_verbose)))
                return false;
        if (profile) {
                pref = profile->enforcing;
                if (pref == &ccs_default_profile.preference)
                        pref = NULL;
        }
        return !pref || ccs_io_printf(head, "%sPREFERENCE::%s={ verbose=%s "
                                      "penalty=%u }\n", buffer, "enforcing",
                                      ccs_yesno(pref->enforcing_verbose),
                                      pref->enforcing_penalty);
}

/**
 * ccs_read_profile - Read profile table.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 */
static void ccs_read_profile(struct ccs_io_buffer *head)
{
        int index;
        if (head->read_eof)
                return;
        if (head->read_bit)
                goto body;
        ccs_io_printf(head, "PROFILE_VERSION=%s\n", "20090903");
        ccs_print_preference(head, -1);
        head->read_bit = 1;
 body:
        for (index = head->read_step; index < CCS_MAX_PROFILES; index++) {
                bool done;
                u8 config;
                int i;
                int pos;
                const struct ccs_profile *profile = ccs_profile_ptr[index];
                const struct ccs_path_info *comment;
                head->read_step = index;
                if (!profile)
                        continue;
                pos = head->read_avail;
                comment = profile->comment;
                done = ccs_io_printf(head, "%u-COMMENT=%s\n", index,
                                     comment ? comment->name : "");
                if (!done)
                        goto out;
                config = profile->default_config;
#ifdef CONFIG_CCSECURITY_AUDIT
                if (!ccs_io_printf(head, "%u-%s%s={ mode=%s "
                                   "grant_log=%s reject_log=%s }\n", index,
                                   "CONFIG", "", ccs_mode[config & 3],
                                   ccs_yesno(config &
                                             CCS_CONFIG_WANT_GRANT_LOG),
                                   ccs_yesno(config &
                                             CCS_CONFIG_WANT_REJECT_LOG)))
                        goto out;
#else
                if (!ccs_io_printf(head, "%u-%s%s={ mode=%s }\n", index,
                                   "CONFIG", "", ccs_mode[config & 3]))
                        goto out;
#endif
                for (i = 0; i < CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX
                             + CCS_MAX_MAC_CATEGORY_INDEX; i++) {
#ifdef CONFIG_CCSECURITY_AUDIT
                        const char *g;
                        const char *r;
#endif
                        config = profile->config[i];
                        if (config == CCS_CONFIG_USE_DEFAULT)
                                continue;
#ifdef CONFIG_CCSECURITY_AUDIT
                        g = ccs_yesno(config & CCS_CONFIG_WANT_GRANT_LOG);
                        r = ccs_yesno(config & CCS_CONFIG_WANT_REJECT_LOG);
                        if (!ccs_io_printf(head, "%u-%s%s={ mode=%s "
                                           "grant_log=%s reject_log=%s }\n",
                                           index, "CONFIG::",
                                           ccs_mac_keywords[i],
                                           ccs_mode[config & 3], g, r))
                                goto out;
#else
                        if (!ccs_io_printf(head, "%u-%s%s={ mode=%s }\n",
                                           index, "CONFIG::",
                                           ccs_mac_keywords[i],
                                           ccs_mode[config & 3]))
                                goto out;
#endif
                }
                if (!ccs_print_preference(head, index))
                        goto out;
                continue;
 out:
                head->read_avail = pos;
                break;
        }
        if (index == CCS_MAX_PROFILES)
                head->read_eof = true;
}

static bool ccs_same_manager_entry(const struct ccs_acl_head *a,
                                   const struct ccs_acl_head *b)
{
        return container_of(a, struct ccs_manager, head)->manager
                == container_of(b, struct ccs_manager, head)->manager;
}

/**
 * ccs_update_manager_entry - Add a manager entry.
 *
 * @manager:   The path to manager or the domainnamme.
 * @is_delete: True if it is a delete request.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int ccs_update_manager_entry(const char *manager, const bool is_delete)
{
        struct ccs_manager e = { };
        int error = is_delete ? -ENOENT : -ENOMEM;
        if (ccs_domain_def(manager)) {
                if (!ccs_correct_domain(manager))
                        return -EINVAL;
                e.is_domain = true;
        } else {
                if (!ccs_correct_path(manager))
                        return -EINVAL;
        }
        e.manager = ccs_get_name(manager);
        if (!e.manager)
                return error;
        error = ccs_update_policy(&e.head, sizeof(e), is_delete,
                                  &ccs_policy_list[CCS_ID_MANAGER],
                                  ccs_same_manager_entry);
        ccs_put_name(e.manager);
        return error;
}

/**
 * ccs_write_manager - Write manager policy.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int ccs_write_manager(struct ccs_io_buffer *head)
{
        char *data = head->write_buf;
        bool is_delete = ccs_str_starts(&data, CCS_KEYWORD_DELETE);
        if (!strcmp(data, "manage_by_non_root")) {
                ccs_manage_by_non_root = !is_delete;
                return 0;
        }
        return ccs_update_manager_entry(data, is_delete);
}

/**
 * ccs_read_manager - Read manager policy.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Caller holds ccs_read_lock().
 */
static void ccs_read_manager(struct ccs_io_buffer *head)
{
        struct list_head *pos;
        if (head->read_eof)
                return;
        list_for_each_cookie(pos, head->read_var2,
                             &ccs_policy_list[CCS_ID_MANAGER]) {
                struct ccs_manager *ptr
                        = list_entry(pos, typeof(*ptr), head.list);
                if (ptr->head.is_deleted)
                        continue;
                if (!ccs_io_printf(head, "%s\n", ptr->manager->name))
                        return;
        }
        head->read_eof = true;
}

/**
 * ccs_manager - Check whether the current process is a policy manager.
 *
 * Returns true if the current process is permitted to modify policy
 * via /proc/ccs/ interface.
 *
 * Caller holds ccs_read_lock().
 */
static bool ccs_manager(void)
{
        struct ccs_manager *ptr;
        const char *exe;
        struct task_struct *task = current;
        const struct ccs_path_info *domainname
                = ccs_current_domain()->domainname;
        bool found = false;
        if (!ccs_policy_loaded)
                return true;
        if (task->ccs_flags & CCS_TASK_IS_MANAGER)
                return true;
        if (!ccs_manage_by_non_root && (current_uid() || current_euid()))
                return false;
        exe = ccs_get_exe();
        list_for_each_entry_rcu(ptr, &ccs_policy_list[CCS_ID_MANAGER],
                                head.list) {
                if (ptr->head.is_deleted)
                        continue;
                if (ptr->is_domain) {
                        if (ccs_pathcmp(domainname, ptr->manager))
                                continue;
                } else {
                        if (!exe || strcmp(exe, ptr->manager->name))
                                continue;
                }
                /* Set manager flag. */
                task->ccs_flags |= CCS_TASK_IS_MANAGER;
                found = true;
                break;
        }
        if (!found) { /* Reduce error messages. */
                static pid_t ccs_last_pid;
                const pid_t pid = current->pid;
                if (ccs_last_pid != pid) {
                        printk(KERN_WARNING "%s ( %s ) is not permitted to "
                               "update policies.\n", domainname->name, exe);
                        ccs_last_pid = pid;
                }
        }
        kfree(exe);
        return found;
}

/**
 * ccs_find_condition_part - Find condition part from the statement.
 *
 * @data: String to parse.
 *
 * Returns pointer to the condition part if it was found in the statement,
 * NULL otherwise.
 */
static char *ccs_find_condition_part(char *data)
{
        char *cp = strstr(data, " if ");
        if (!cp)
                cp = strstr(data, " ; set ");
        if (cp)
                *cp++ = '\0';
        return cp;
}

/**
 * ccs_select_one - Parse select command.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @data: String to parse.
 *
 * Returns true on success, false otherwise.
 *
 * Caller holds ccs_read_lock().
 */
static bool ccs_select_one(struct ccs_io_buffer *head, const char *data)
{
        unsigned int pid;
        struct ccs_domain_info *domain = NULL;
        bool global_pid = false;
        if (!strcmp(data, "allow_execute")) {
                head->read_execute_only = true;
                return true;
        }
        if (sscanf(data, "pid=%u", &pid) == 1 ||
            (global_pid = true, sscanf(data, "global-pid=%u", &pid) == 1)) {
                struct task_struct *p;
                ccs_tasklist_lock();
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24)
                if (global_pid)
                        p = ccsecurity_exports.find_task_by_pid_ns(pid,
                                                               &init_pid_ns);
                else
                        p = ccsecurity_exports.find_task_by_vpid(pid);
#else
                p = find_task_by_pid(pid);
#endif
                if (p)
                        domain = ccs_task_domain(p);
                ccs_tasklist_unlock();
        } else if (!strncmp(data, "domain=", 7)) {
                if (ccs_domain_def(data + 7))
                        domain = ccs_find_domain(data + 7);
        } else
                return false;
        head->write_var1 = domain;
        /* Accessing read_buf is safe because head->io_sem is held. */
        if (!head->read_buf)
                return true; /* Do nothing if open(O_WRONLY). */
        head->read_avail = 0;
        ccs_io_printf(head, "# select %s\n", data);
        head->read_single_domain = true;
        head->read_eof = !domain;
        if (domain) {
                struct ccs_domain_info *d;
                head->read_var1 = NULL;
                list_for_each_entry_rcu(d, &ccs_domain_list, list) {
                        if (d == domain)
                                break;
                        head->read_var1 = &d->list;
                }
                head->read_var2 = NULL;
                head->read_bit = 0;
                head->read_step = 0;
                if (domain->is_deleted)
                        ccs_io_printf(head, "# This is a deleted domain.\n");
        }
        return true;
}

static int ccs_write_domain2(char *data, struct ccs_domain_info *domain,
                             const bool is_delete)
{
        static const struct {
                const char *keyword;
                int (*write) (char *, struct ccs_domain_info *,
                              struct ccs_condition *, const bool);
        } ccs_callback[5] = {
                { CCS_KEYWORD_ALLOW_NETWORK, ccs_write_network },
                { CCS_KEYWORD_ALLOW_ENV, ccs_write_env },
                { CCS_KEYWORD_ALLOW_CAPABILITY, ccs_write_capability },
                { CCS_KEYWORD_ALLOW_SIGNAL, ccs_write_signal },
                { CCS_KEYWORD_ALLOW_MOUNT, ccs_write_mount }
        };
        int (*write) (char *, struct ccs_domain_info *, struct ccs_condition *,
                      const bool) = ccs_write_file;
        int error;
        u8 i;
        struct ccs_condition *cond = NULL;
        char *cp = ccs_find_condition_part(data);
        if (cp) {
                cond = ccs_get_condition(cp);
                if (!cond)
                        return -EINVAL;
        }
        for (i = 0; i < 5; i++) {
                if (!ccs_str_starts(&data, ccs_callback[i].keyword))
                        continue;
                write = ccs_callback[i].write;
                break;
        }
        error = write(data, domain, cond, is_delete);
        if (cond)
                ccs_put_condition(cond);
        return error;
}

static const char *ccs_dif[CCS_MAX_DOMAIN_INFO_FLAGS] = {
        [CCS_DIF_QUOTA_WARNED] = CCS_KEYWORD_QUOTA_EXCEEDED "\n",
        [CCS_DIF_IGNORE_GLOBAL] = CCS_KEYWORD_IGNORE_GLOBAL "\n",
        [CCS_DIF_IGNORE_GLOBAL_ALLOW_READ]
        = CCS_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n",
        [CCS_DIF_IGNORE_GLOBAL_ALLOW_ENV]
        = CCS_KEYWORD_IGNORE_GLOBAL_ALLOW_ENV "\n",
        [CCS_DIF_TRANSITION_FAILED] = CCS_KEYWORD_TRANSITION_FAILED "\n"
};
        
/**
 * ccs_write_domain - Write domain policy.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int ccs_write_domain(struct ccs_io_buffer *head)
{
        char *data = head->write_buf;
        struct ccs_domain_info *domain = head->write_var1;
        bool is_delete = false;
        bool is_select = false;
        unsigned int profile;
        if (ccs_str_starts(&data, CCS_KEYWORD_DELETE))
                is_delete = true;
        else if (ccs_str_starts(&data, CCS_KEYWORD_SELECT))
                is_select = true;
        if (is_select && ccs_select_one(head, data))
                return 0;
        /* Don't allow updating policies by non manager programs. */
        if (!ccs_manager())
                return -EPERM;
        if (ccs_domain_def(data)) {
                domain = NULL;
                if (is_delete)
                        ccs_delete_domain(data);
                else if (is_select)
                        domain = ccs_find_domain(data);
                else
                        domain = ccs_assign_domain(data, 0);
                head->write_var1 = domain;
                return 0;
        }
        if (!domain)
                return -EINVAL;

        if (sscanf(data, CCS_KEYWORD_USE_PROFILE "%u", &profile) == 1
            && profile < CCS_MAX_PROFILES) {
                if (!ccs_policy_loaded || ccs_profile_ptr[(u8) profile])
                        domain->profile = (u8) profile;
                return 0;
        }
        for (profile = 0; profile < CCS_MAX_DOMAIN_INFO_FLAGS; profile++) {
                const char *cp = ccs_dif[profile];
                if (strncmp(data, cp, strlen(cp) - 1))
                        continue;
                domain->flags[profile] = !is_delete;
                return 0;
        }
        return ccs_write_domain2(data, domain, is_delete);
}

/**
 * ccs_print_name_union - Print a ccs_name_union.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_name_union".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_name_union(struct ccs_io_buffer *head,
                                 const struct ccs_name_union *ptr)
{
        int pos = head->read_avail;
        if (pos && head->read_buf[pos - 1] == ' ')
                head->read_avail--;
        if (ptr->is_group)
                return ccs_io_printf(head, " @%s",
                                     ptr->group->group_name->name);
        return ccs_io_printf(head, " %s", ptr->filename->name);
}

/**
 * ccs_print_name_union_quoted - Print a ccs_name_union with double quotes.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_name_union".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_name_union_quoted(struct ccs_io_buffer *head,
                                        const struct ccs_name_union *ptr)
{
        if (ptr->is_group)
                return ccs_io_printf(head, "@%s",
                                     ptr->group->group_name->name);
        return ccs_io_printf(head, "\"%s\"", ptr->filename->name);
}

static void ccs_print_number(char *buffer, int buffer_len,
                             const struct ccs_number_union *ptr)
{
        int i;
        unsigned long min = ptr->values[0];
        const unsigned long max = ptr->values[1];
        u8 min_type = ptr->value_type[0];
        const u8 max_type = ptr->value_type[1];
        memset(buffer, 0, buffer_len);
        buffer_len -= 2;
        for (i = 0; i < 2; i++) {
                int len;
                switch (min_type) {
                case CCS_VALUE_TYPE_HEXADECIMAL:
                        snprintf(buffer, buffer_len, "0x%lX", min);
                        break;
                case CCS_VALUE_TYPE_OCTAL:
                        snprintf(buffer, buffer_len, "0%lo", min);
                        break;
                default:
                        snprintf(buffer, buffer_len, "%lu", min);
                        break;
                }
                if (min == max && min_type == max_type)
                        break;
                len = strlen(buffer);
                buffer[len++] = '-';
                buffer += len;
                buffer_len -= len;
                min_type = max_type;
                min = max;
        }
}

/**
 * ccs_print_number_union_common - Print a ccs_number_union.
 *
 * @head:       Pointer to "struct ccs_io_buffer".
 * @ptr:        Pointer to "struct ccs_number_union".
 * @need_space: True if a space character is needed.
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_number_union_common(struct ccs_io_buffer *head,
                                          const struct ccs_number_union *ptr,
                                          const bool need_space)
{
        char buffer[128];
        if (need_space && !ccs_io_printf(head, " "))
                return false;
        if (ptr->is_group)
                return ccs_io_printf(head, "@%s",
                                     ptr->group->group_name->name);
        ccs_print_number(buffer, sizeof(buffer), ptr);
        return ccs_io_printf(head, "%s", buffer);
}

/**
 * ccs_print_number_union - Print a ccs_number_union.
 *
 * @head:       Pointer to "struct ccs_io_buffer".
 * @ptr:        Pointer to "struct ccs_number_union".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_number_union(struct ccs_io_buffer *head,
                                   const struct ccs_number_union *ptr)
{
        return ccs_print_number_union_common(head, ptr, true);
}

/**
 * ccs_print_number_union_nospace - Print a ccs_number_union without a space character.
 *
 * @head:       Pointer to "struct ccs_io_buffer".
 * @ptr:        Pointer to "struct ccs_number_union".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_number_union_nospace(struct ccs_io_buffer *head,
                                           const struct ccs_number_union *ptr)
{
        return ccs_print_number_union_common(head, ptr, false);
}

/**
 * ccs_print_condition - Print condition part.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @cond: Pointer to "struct ccs_condition". Maybe NULL.
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_condition(struct ccs_io_buffer *head,
                                const struct ccs_condition *cond)
{
        const struct ccs_condition_element *condp;
        const struct ccs_number_union *numbers_p;
        const struct ccs_name_union *names_p;
        const struct ccs_argv *argv;
        const struct ccs_envp *envp;
        u16 condc;
        u16 i;
        u16 j;
        char buffer[32];
        if (!cond)
                goto no_condition;
        condc = cond->condc;
        condp = (const struct ccs_condition_element *) (cond + 1);
        numbers_p = (const struct ccs_number_union *) (condp + condc);
        names_p = (const struct ccs_name_union *)
                (numbers_p + cond->numbers_count);
        argv = (const struct ccs_argv *) (names_p + cond->names_count);
        envp = (const struct ccs_envp *) (argv + cond->argc);
        memset(buffer, 0, sizeof(buffer));
        if (condc && !ccs_io_printf(head, "%s", " if"))
                goto out;
        for (i = 0; i < condc; i++) {
                const u8 match = condp->equals;
                const u8 left = condp->left;
                const u8 right = condp->right;
                condp++;
                switch (left) {
                case CCS_ARGV_ENTRY:
                        if (!ccs_io_printf(head, " exec.argv[%u]%s\"%s\"",
                                           argv->index, argv->is_not ?
                                           "!=" : "=", argv->value->name))
                                goto out;
                        argv++;
                        continue;
                case CCS_ENVP_ENTRY:
                        if (!ccs_io_printf(head, " exec.envp[\"%s\"]%s",
                                           envp->name->name, envp->is_not ?
                                           "!=" : "="))
                                goto out;
                        if (envp->value) {
                                if (!ccs_io_printf(head, "\"%s\"",
                                                   envp->value->name))
                                        goto out;
                        } else {
                                if (!ccs_io_printf(head, "NULL"))
                                        goto out;
                        }
                        envp++;
                        continue;
                case CCS_NUMBER_UNION:
                        if (!ccs_print_number_union(head, numbers_p++))
                                goto out;
                        break;
                default:
                        if (left >= CCS_MAX_CONDITION_KEYWORD)
                                goto out;
                        if (!ccs_io_printf(head, " %s",
                                           ccs_condition_keyword[left]))
                                goto out;
                        break;
                }
                if (!ccs_io_printf(head, "%s", match ? "=" : "!="))
                        goto out;
                switch (right) {
                case CCS_NAME_UNION:
                        if (!ccs_print_name_union_quoted(head, names_p++))
                                goto out;
                        break;
                case CCS_NUMBER_UNION:
                        if (!ccs_print_number_union_nospace(head, numbers_p++))
                                goto out;
                        break;
                default:
                        if (right >= CCS_MAX_CONDITION_KEYWORD)
                                goto out;
                        if (!ccs_io_printf(head, "%s",
                                           ccs_condition_keyword[right]))
                                goto out;
                        break;
                }
        }
        i = cond->post_state[3];
        if (!i)
                goto no_condition;
        if (!ccs_io_printf(head, " ; set"))
                goto out;
        for (j = 0; j < 3; j++) {
                if (!(i & (1 << j)))
                        continue;
                if (!ccs_io_printf(head, " task.state[%u]=%u", j,
                                   cond->post_state[j]))
                        goto out;
        }
        if (i & (1 << 4)) {
                if (!ccs_io_printf(head, " audit=%s",
                                   ccs_yesno(cond->post_state[4])))
                        goto out;
        }
 no_condition:
        if (ccs_io_printf(head, "\n"))
                return true;
 out:
        return false;
}

/**
 * ccs_print_path_acl - Print a path ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_path_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_path_acl(struct ccs_io_buffer *head,
                               const struct ccs_path_acl *ptr)
{
        int pos;
        u8 bit;
        const u16 perm = ptr->perm;
        for (bit = head->read_bit; bit < CCS_MAX_PATH_OPERATION; bit++) {
                if (!(perm & (1 << bit)))
                        continue;
                if (head->read_execute_only && bit != CCS_TYPE_EXECUTE
                    && bit != CCS_TYPE_TRANSIT)
                        continue;
                /* Print "read/write" instead of "read" and "write". */
                if ((bit == CCS_TYPE_READ || bit == CCS_TYPE_WRITE)
                    && (perm & (1 << CCS_TYPE_READ_WRITE)))
                        continue;
                pos = head->read_avail;
                if (!ccs_io_printf(head, "allow_%s", ccs_path_keyword[bit]) ||
                    !ccs_print_name_union(head, &ptr->name) ||
                    !ccs_print_condition(head, ptr->head.cond)) {
                        head->read_bit = bit;
                        head->read_avail = pos;
                        return false;
                }
        }
        head->read_bit = 0;
        return true;
}

/**
 * ccs_print_mkdev_acl - Print a mkdev ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_mkdev_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_mkdev_acl(struct ccs_io_buffer *head,
                                const struct ccs_mkdev_acl *ptr)
{
        int pos;
        u8 bit;
        const u16 perm = ptr->perm;
        for (bit = head->read_bit; bit < CCS_MAX_MKDEV_OPERATION;
             bit++) {
                if (!(perm & (1 << bit)))
                        continue;
                pos = head->read_avail;
                if (!ccs_io_printf(head, "allow_%s", ccs_mkdev_keyword[bit]) ||
                    !ccs_print_name_union(head, &ptr->name) ||
                    !ccs_print_number_union(head, &ptr->mode) ||
                    !ccs_print_number_union(head, &ptr->major) ||
                    !ccs_print_number_union(head, &ptr->minor) ||
                    !ccs_print_condition(head, ptr->head.cond)) {
                        head->read_bit = bit;
                        head->read_avail = pos;
                        return false;
                }
        }
        head->read_bit = 0;
        return true;
}

/**
 * ccs_print_path2_acl - Print a path2 ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_path2_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_path2_acl(struct ccs_io_buffer *head,
                                const struct ccs_path2_acl *ptr)
{
        int pos;
        u8 bit;
        const u8 perm = ptr->perm;
        for (bit = head->read_bit; bit < CCS_MAX_PATH2_OPERATION; bit++) {
                if (!(perm & (1 << bit)))
                        continue;
                pos = head->read_avail;
                if (!ccs_io_printf(head, "allow_%s", ccs_path2_keyword[bit]) ||
                    !ccs_print_name_union(head, &ptr->name1) ||
                    !ccs_print_name_union(head, &ptr->name2) ||
                    !ccs_print_condition(head, ptr->head.cond)) {
                        head->read_bit = bit;
                        head->read_avail = pos;
                        return false;
                }
        }
        head->read_bit = 0;
        return true;
}

/**
 * ccs_print_path_number_acl - Print a path_number ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_path_number_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_path_number_acl(struct ccs_io_buffer *head,
                                      const struct ccs_path_number_acl *ptr)
{
        int pos;
        u8 bit;
        const u8 perm = ptr->perm;
        for (bit = head->read_bit; bit < CCS_MAX_PATH_NUMBER_OPERATION;
             bit++) {
                if (!(perm & (1 << bit)))
                        continue;
                pos = head->read_avail;
                if (!ccs_io_printf(head, "allow_%s",
                                   ccs_path_number_keyword[bit]) ||
                    !ccs_print_name_union(head, &ptr->name) ||
                    !ccs_print_number_union(head, &ptr->number) ||
                    !ccs_print_condition(head, ptr->head.cond)) {
                        head->read_bit = bit;
                        head->read_avail = pos;
                        return false;
                }
        }
        head->read_bit = 0;
        return true;
}

/**
 * ccs_print_env_acl - Print an evironment variable name's ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_env_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_env_acl(struct ccs_io_buffer *head,
                              const struct ccs_env_acl *ptr)
{
        const int pos = head->read_avail;
        if (!ccs_io_printf(head, CCS_KEYWORD_ALLOW_ENV "%s", ptr->env->name) ||
            !ccs_print_condition(head, ptr->head.cond)) {
                head->read_avail = pos;
                return false;
        }
        return true;
}

/**
 * ccs_print_capability_acl - Print a capability ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_capability_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_capability_acl(struct ccs_io_buffer *head,
                                     const struct ccs_capability_acl *ptr)
{
        const int pos = head->read_avail;
        if (!ccs_io_printf(head, CCS_KEYWORD_ALLOW_CAPABILITY "%s",
                           ccs_cap2keyword(ptr->operation)) ||
            !ccs_print_condition(head, ptr->head.cond)) {
                head->read_avail = pos;
                return false;
        }
        return true;
}

/**
 * ccs_print_network_acl - Print a network ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_ip_network_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_network_acl(struct ccs_io_buffer *head,
                                  const struct ccs_ip_network_acl *ptr)
{
        int pos;
        u8 bit;
        const u8 perm = ptr->perm;
        char buf[128];
        for (bit = head->read_bit; bit < CCS_MAX_NETWORK_OPERATION; bit++) {
                const char *w[2] = { buf, "" };
                if (!(perm & (1 << bit)))
                        continue;
                pos = head->read_avail;
                switch (ptr->address_type) {
                case CCS_IP_ADDRESS_TYPE_ADDRESS_GROUP:
                        w[0] = "@";
                        w[1] = ptr->address.group->group_name->name;
                        break;
                case CCS_IP_ADDRESS_TYPE_IPv4:
                        ccs_print_ipv4(buf, sizeof(buf), ptr->address.ipv4.min,
                                       ptr->address.ipv4.max);
                        break;
                case CCS_IP_ADDRESS_TYPE_IPv6:
                        ccs_print_ipv6(buf, sizeof(buf), ptr->address.ipv6.min,
                                       ptr->address.ipv6.max);
                        break;
                }
                if (!ccs_io_printf(head, CCS_KEYWORD_ALLOW_NETWORK "%s %s%s",
                                   ccs_net_keyword[bit], w[0], w[1]) ||
                    !ccs_print_number_union(head, &ptr->port) ||
                    !ccs_print_condition(head, ptr->head.cond))
                        goto out;
        }
        head->read_bit = 0;
        return true;
 out:
        head->read_bit = bit;
        head->read_avail = pos;
        return false;
}

/**
 * ccs_print_signal_acl - Print a signal ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct signale_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_signal_acl(struct ccs_io_buffer *head,
                                 const struct ccs_signal_acl *ptr)
{
        const int pos = head->read_avail;
        if (!ccs_io_printf(head, CCS_KEYWORD_ALLOW_SIGNAL "%u %s",
                           ptr->sig, ptr->domainname->name) ||
            !ccs_print_condition(head, ptr->head.cond)) {
                head->read_avail = pos;
                return false;
        }
        return true;
}

/**
 * ccs_print_execute_handler - Print an execute handler ACL entry.
 *
 * @head:    Pointer to "struct ccs_io_buffer".
 * @keyword: Name of the keyword.
 * @ptr:     Pointer to "struct ccs_execute_handler".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_execute_handler(struct ccs_io_buffer *head,
                                      const char *keyword,
                                      const struct ccs_execute_handler *ptr)
{
        const int pos = head->read_avail;
        if (!ccs_io_printf(head, "%s %s", keyword, ptr->handler->name) ||
            !ccs_print_condition(head, ptr->head.cond)) {
                head->read_avail = pos;
                return false;
        }
        return true;
}

/**
 * ccs_print_mount_acl - Print a mount ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to "struct ccs_mount_acl".
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_mount_acl(struct ccs_io_buffer *head,
                                const struct ccs_mount_acl *ptr)
{
        const int pos = head->read_avail;
        if (!ccs_io_printf(head, CCS_KEYWORD_ALLOW_MOUNT) ||
            !ccs_print_name_union(head, &ptr->dev_name) ||
            !ccs_print_name_union(head, &ptr->dir_name) ||
            !ccs_print_name_union(head, &ptr->fs_type) ||
            !ccs_print_number_union(head, &ptr->flags) ||
            !ccs_print_condition(head, ptr->head.cond)) {
                head->read_avail = pos;
                return false;
        }
        return true;
}

/**
 * ccs_print_entry - Print an ACL entry.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @ptr:  Pointer to an ACL entry.
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_print_entry(struct ccs_io_buffer *head,
                            const struct ccs_acl_info *ptr)
{
        const u8 acl_type = ptr->type;
        if (ptr->is_deleted)
                return true;
        if (acl_type == CCS_TYPE_PATH_ACL) {
                struct ccs_path_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_path_acl(head, acl);
        }
        if (acl_type == CCS_TYPE_EXECUTE_HANDLER ||
            acl_type == CCS_TYPE_DENIED_EXECUTE_HANDLER) {
                struct ccs_execute_handler *acl
                        = container_of(ptr, typeof(*acl), head);
                const char *keyword = acl_type == CCS_TYPE_EXECUTE_HANDLER ?
                        CCS_KEYWORD_EXECUTE_HANDLER :
                        CCS_KEYWORD_DENIED_EXECUTE_HANDLER;
                return ccs_print_execute_handler(head, keyword, acl);
        }
        if (head->read_execute_only)
                return true;
        if (acl_type == CCS_TYPE_MKDEV_ACL) {
                struct ccs_mkdev_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_mkdev_acl(head, acl);
        }
        if (acl_type == CCS_TYPE_PATH2_ACL) {
                struct ccs_path2_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_path2_acl(head, acl);
        }
        if (acl_type == CCS_TYPE_PATH_NUMBER_ACL) {
                struct ccs_path_number_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_path_number_acl(head, acl);
        }
        if (acl_type == CCS_TYPE_ENV_ACL) {
                struct ccs_env_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_env_acl(head, acl);
        }
        if (acl_type == CCS_TYPE_CAPABILITY_ACL) {
                struct ccs_capability_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_capability_acl(head, acl);
        }
        if (acl_type == CCS_TYPE_IP_NETWORK_ACL) {
                struct ccs_ip_network_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_network_acl(head, acl);
        }
        if (acl_type == CCS_TYPE_SIGNAL_ACL) {
                struct ccs_signal_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_signal_acl(head, acl);
        }
        if (acl_type == CCS_TYPE_MOUNT_ACL) {
                struct ccs_mount_acl *acl
                        = container_of(ptr, typeof(*acl), head);
                return ccs_print_mount_acl(head, acl);
        }
        BUG(); /* This must not happen. */
        return false;
}

/**
 * ccs_read_domain2 - Read domain policy.
 *
 * @head:   Pointer to "struct ccs_io_buffer".
 * @domain: Pointer to "struct ccs_domain_info".
 *
 * Caller holds ccs_read_lock().
 *
 * Returns true on success, false otherwise.
 */
static bool ccs_read_domain2(struct ccs_io_buffer *head,
                             struct ccs_domain_info *domain)
{
        struct list_head *pos;
        /* Print ACL entries in the domain. */
        list_for_each_cookie(pos, head->read_var2, &domain->acl_info_list) {
                struct ccs_acl_info *ptr
                        = list_entry(pos, struct ccs_acl_info, list);
                if (!ccs_print_entry(head, ptr))
                        return false;
        }
        return true;
}

/**
 * ccs_read_domain - Read domain policy.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Caller holds ccs_read_lock().
 */
static void ccs_read_domain(struct ccs_io_buffer *head)
{
        struct list_head *pos;
        if (head->read_eof)
                return;
        list_for_each_cookie(pos, head->read_var1, &ccs_domain_list) {
                struct ccs_domain_info *domain =
                        list_entry(pos, struct ccs_domain_info, list);
                switch (head->read_step) {
                        u8 i;
                        const char *w[CCS_MAX_DOMAIN_INFO_FLAGS];
                case 0:
                        if (domain->is_deleted && !head->read_single_domain)
                                continue;
                        /* Print domainname and flags. */
                        for (i = 0; i < CCS_MAX_DOMAIN_INFO_FLAGS; i++)
                                w[i] = domain->flags[i] ? ccs_dif[i] : "";
                        if (!ccs_io_printf(head, "%s\n" CCS_KEYWORD_USE_PROFILE
                                           "%u\n%s%s%s%s%s\n",
                                           domain->domainname->name,
                                           domain->profile,
                                           w[CCS_DIF_QUOTA_WARNED],
                                           w[CCS_DIF_IGNORE_GLOBAL],
                                           w[CCS_DIF_IGNORE_GLOBAL_ALLOW_READ],
                                           w[CCS_DIF_IGNORE_GLOBAL_ALLOW_ENV],
                                           w[CCS_DIF_TRANSITION_FAILED]))
                                return;
                        head->read_step++;
                        /* fall through */
                case 1:
                        if (!ccs_read_domain2(head, domain))
                                return;
                        head->read_step++;
                        /* fall through */
                case 2:
                        if (!ccs_io_printf(head, "\n"))
                                return;
                        head->read_step = 0;
                        if (head->read_single_domain)
                                goto out;
                }
        }
 out:
        head->read_eof = true;
}

/**
 * ccs_write_domain_profile - Assign profile for specified domain.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Returns 0 on success, -EINVAL otherwise.
 *
 * This is equivalent to doing
 *
 *     ( echo "select " $domainname; echo "use_profile " $profile ) |
 *     /usr/sbin/ccs-loadpolicy -d
 *
 * Caller holds ccs_read_lock().
 */
static int ccs_write_domain_profile(struct ccs_io_buffer *head)
{
        char *data = head->write_buf;
        char *cp = strchr(data, ' ');
        struct ccs_domain_info *domain;
        unsigned int profile;
        if (!cp)
                return -EINVAL;
        *cp = '\0';
        profile = simple_strtoul(data, NULL, 10);
        if (profile >= CCS_MAX_PROFILES)
                return -EINVAL;
        domain = ccs_find_domain(cp + 1);
        if (domain && (!ccs_policy_loaded || ccs_profile_ptr[(u8) profile]))
                domain->profile = (u8) profile;
        return 0;
}

/**
 * ccs_read_domain_profile - Read only domainname and profile.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * This is equivalent to doing
 *
 *     grep -A 1 '^<kernel>' /proc/ccs/domain_policy |
 *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
 *     domainname = $0; } else if ( $1 == "use_profile" ) {
 *     print $2 " " domainname; domainname = ""; } } ; '
 *
 * Caller holds ccs_read_lock().
 */
static void ccs_read_domain_profile(struct ccs_io_buffer *head)
{
        struct list_head *pos;
        if (head->read_eof)
                return;
        list_for_each_cookie(pos, head->read_var1, &ccs_domain_list) {
                struct ccs_domain_info *domain;
                domain = list_entry(pos, struct ccs_domain_info, list);
                if (domain->is_deleted)
                        continue;
                if (!ccs_io_printf(head, "%u %s\n", domain->profile,
                                   domain->domainname->name))
                        return;
        }
        head->read_eof = true;
}

/**
 * ccs_write_pid: Specify PID to obtain domainname.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Returns 0.
 */
static int ccs_write_pid(struct ccs_io_buffer *head)
{
        head->read_eof = false;
        return 0;
}

/**
 * ccs_read_pid - Read information of a process.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Returns the domainname which the specified PID is in or
 * process information of the specified PID on success,
 * empty string otherwise.
 *
 * Caller holds ccs_read_lock().
 */
static void ccs_read_pid(struct ccs_io_buffer *head)
{
        char *buf = head->write_buf;
        bool task_info = false;
        bool global_pid = false;
        unsigned int pid;
        struct task_struct *p;
        struct ccs_domain_info *domain = NULL;
        u32 ccs_flags = 0;
        /* Accessing write_buf is safe because head->io_sem is held. */
        if (!buf) {
                head->read_eof = true;
                return; /* Do nothing if open(O_RDONLY). */
        }
        if (head->read_avail || head->read_eof)
                return;
        head->read_eof = true;
        if (ccs_str_starts(&buf, "info "))
                task_info = true;
        if (ccs_str_starts(&buf, "global-pid "))
                global_pid = true;
        pid = (unsigned int) simple_strtoul(buf, NULL, 10);
        ccs_tasklist_lock();
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 24)
        if (global_pid)
                p = ccsecurity_exports.find_task_by_pid_ns(pid, &init_pid_ns);
        else
                p = ccsecurity_exports.find_task_by_vpid(pid);
#else
        p = find_task_by_pid(pid);
#endif
        if (p) {
                domain = ccs_task_domain(p);
                ccs_flags = p->ccs_flags;
        }
        ccs_tasklist_unlock();
        if (!domain)
                return;
        if (!task_info)
                ccs_io_printf(head, "%u %u %s", pid, domain->profile,
                              domain->domainname->name);
        else
                ccs_io_printf(head, "%u manager=%s execute_handler=%s "
                              "state[0]=%u state[1]=%u state[2]=%u", pid,
                              ccs_yesno(ccs_flags &
                                        CCS_TASK_IS_MANAGER),
                              ccs_yesno(ccs_flags &
                                        CCS_TASK_IS_EXECUTE_HANDLER),
                              (u8) (ccs_flags >> 24),
                              (u8) (ccs_flags >> 16),
                              (u8) (ccs_flags >> 8));
}

static const char *ccs_transition_type[CCS_MAX_TRANSITION_TYPE] = {
        [CCS_TRANSITION_CONTROL_NO_INITIALIZE]
        = CCS_KEYWORD_NO_INITIALIZE_DOMAIN,
        [CCS_TRANSITION_CONTROL_INITIALIZE] = CCS_KEYWORD_INITIALIZE_DOMAIN,
        [CCS_TRANSITION_CONTROL_NO_KEEP] = CCS_KEYWORD_NO_KEEP_DOMAIN,
        [CCS_TRANSITION_CONTROL_KEEP] = CCS_KEYWORD_KEEP_DOMAIN
};

static const char *ccs_group_name[CCS_MAX_GROUP] = {
        [CCS_PATH_GROUP] = CCS_KEYWORD_PATH_GROUP,
        [CCS_NUMBER_GROUP] = CCS_KEYWORD_NUMBER_GROUP,
        [CCS_ADDRESS_GROUP] = CCS_KEYWORD_ADDRESS_GROUP
};

/**
 * ccs_write_exception - Write exception policy.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int ccs_write_exception(struct ccs_io_buffer *head)
{
        char *data = head->write_buf;
        const bool is_delete = ccs_str_starts(&data, CCS_KEYWORD_DELETE);
        u8 i;
        static const struct {
                const char *keyword;
                int (*write) (char *, const bool);
        } ccs_callback[4] = {
                { CCS_KEYWORD_AGGREGATOR, ccs_write_aggregator },
                { CCS_KEYWORD_FILE_PATTERN, ccs_write_pattern },
                { CCS_KEYWORD_DENY_REWRITE, ccs_write_no_rewrite },
                { CCS_KEYWORD_DENY_AUTOBIND, ccs_write_reserved_port }
        };
        for (i = 0; i < 4; i++) {
                if (ccs_str_starts(&data, ccs_callback[i].keyword))
                        return ccs_callback[i].write(data, is_delete);
        }
        for (i = 0; i < CCS_MAX_TRANSITION_TYPE; i++) {
                if (ccs_str_starts(&data, ccs_transition_type[i]))
                        return ccs_write_transition_control(data, is_delete,
                                                            i);
        }
        for (i = 0; i < CCS_MAX_GROUP; i++) {
                if (ccs_str_starts(&data, ccs_group_name[i]))
                        return ccs_write_group(data, is_delete, i);
        }
        return ccs_write_domain2(data, &ccs_global_domain, is_delete);
}

/**
 * ccs_read_group - Read "struct ccs_path_group"/"struct ccs_number_group"/"struct ccs_address_group" list.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @idx:  Index number.
 *
 * Returns true on success, false otherwise.
 *
 * Caller holds ccs_read_lock().
 */
static bool ccs_read_group(struct ccs_io_buffer *head, const int idx)
{
        struct list_head *gpos;
        struct list_head *mpos;
        const char *w[3] = { "", "", "" };
        w[0] = ccs_group_name[idx];
        list_for_each_cookie(gpos, head->read_var1, &ccs_group_list[idx]) {
                struct ccs_group *group =
                        list_entry(gpos, struct ccs_group, head.list);
                w[1] = group->group_name->name;
                list_for_each_cookie(mpos, head->read_var2,
                                     &group->member_list) {
                        char buffer[128];
                        struct ccs_acl_head *ptr =
                                list_entry(mpos, struct ccs_acl_head, list);
                        if (ptr->is_deleted)
                                continue;
                        w[2] = buffer;
                        if (idx == CCS_PATH_GROUP) {
                                w[2] = container_of(ptr, struct ccs_path_group,
                                                    head)->member_name->name;
                        } else if (idx == CCS_NUMBER_GROUP) {
                                ccs_print_number(buffer, sizeof(buffer),
                                                 &container_of
                                                 (ptr, struct ccs_number_group,
                                                  head)->number);
                        } else if (idx == CCS_ADDRESS_GROUP) {
                                struct ccs_address_group *member =
                                        container_of(ptr, typeof(*member),
                                                     head);
                                if (member->is_ipv6)
                                        ccs_print_ipv6(buffer, sizeof(buffer),
                                                       member->min.ipv6,
                                                       member->max.ipv6);
                                else
                                        ccs_print_ipv4(buffer, sizeof(buffer),
                                                       member->min.ipv4,
                                                       member->max.ipv4);
                        }
                        if (!ccs_io_printf(head, "%s%s %s\n", w[0], w[1],
                                           w[2]))
                                return false;
                }
        }
        return true;
}

/**
 * ccs_read_policy - Read "struct ccs_..._entry" list.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 * @idx:  Index number.
 *
 * Returns true on success, false otherwise.
 *
 * Caller holds ccs_read_lock().
 */
static bool ccs_read_policy(struct ccs_io_buffer *head, const int idx)
{
        struct list_head *pos;
        list_for_each_cookie(pos, head->read_var2, &ccs_policy_list[idx]) {
                const char *w[4] = { "", "", "", "" };
                char buffer[16];
                struct ccs_acl_head *acl = container_of(pos, typeof(*acl),
                                                        list);
                if (acl->is_deleted)
                        continue;
                switch (idx) {
                case CCS_ID_TRANSITION_CONTROL:
                        {
                                struct ccs_transition_control *ptr =
                                        container_of(acl, typeof(*ptr), head);
                                w[0] = ccs_transition_type[ptr->type];
                                w[1] = ptr->program ? ptr->program->name
                                        : "any";
                                w[2] = " from ";
                                w[3] = ptr->domainname ? ptr->domainname->name
                                        : "any";
                        }
                        break;
                case CCS_ID_AGGREGATOR:
                        {
                                struct ccs_aggregator *ptr =
                                        container_of(acl, typeof(*ptr), head);
                                w[0] = CCS_KEYWORD_AGGREGATOR;
                                w[1] = ptr->original_name->name;
                                w[2] = " ";
                                w[3] = ptr->aggregated_name->name;
                        }
                        break;
                case CCS_ID_PATTERN:
                        {
                                struct ccs_pattern *ptr =
                                        container_of(acl, typeof(*ptr), head);
                                w[0] = CCS_KEYWORD_FILE_PATTERN;
                                w[1] = ptr->pattern->name;
                        }
                        break;
                case CCS_ID_NO_REWRITE:
                        {
                                struct ccs_no_rewrite *ptr =
                                        container_of(acl, typeof(*ptr), head);
                                w[0] = CCS_KEYWORD_DENY_REWRITE;
                                w[1] = ptr->pattern->name;
                        }
                        break;
                case CCS_ID_RESERVEDPORT:
                        {
                                struct ccs_reserved *ptr =
                                        container_of(acl, typeof(*ptr), head);
                                const u16 min_port = ptr->min_port;
                                const u16 max_port = ptr->max_port;
                                w[0] = CCS_KEYWORD_DENY_AUTOBIND;
                                snprintf(buffer, sizeof(buffer) - 1, "%u%c%u",
                                         min_port, min_port != max_port ?
                                         '-' : '\0', max_port);
                                buffer[sizeof(buffer) - 1] = '\0';
                                w[1] = buffer;
                        }
                        break;
                default:
                        continue;
                }
                if (!ccs_io_printf(head, "%s%s%s%s\n", w[0], w[1], w[2], w[3]))
                        return false;
        }
        return true;
}

static void ccs_read_global_domain(struct ccs_io_buffer *head)
{
        if (!head->read_eof)
                head->read_eof = ccs_read_domain2(head, &ccs_global_domain);
}

/**
 * ccs_read_exception - Read exception policy.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 *
 * Caller holds ccs_read_lock().
 */
static void ccs_read_exception(struct ccs_io_buffer *head)
{
        if (head->read_eof)
                return;
        while (head->read_step < CCS_MAX_POLICY &&
               ccs_read_policy(head, head->read_step))
                head->read_step++;
        if (head->read_step < CCS_MAX_POLICY)
                return;
        while (head->read_step < CCS_MAX_POLICY + CCS_MAX_GROUP &&
               ccs_read_group(head, head->read_step - CCS_MAX_POLICY))
                head->read_step++;
        if (head->read_step < CCS_MAX_POLICY + CCS_MAX_GROUP)
                return;
        head->read = ccs_read_global_domain;
}

/* Wait queue for ccs_query_list. */
static DECLARE_WAIT_QUEUE_HEAD(ccs_query_wait);

/* Lock for manipulating ccs_query_list. */
static DEFINE_SPINLOCK(ccs_query_list_lock);

/* Structure for query. */
struct ccs_query_entry {
        struct list_head list;
        char *query;
        int query_len;
        unsigned int serial;
        int timer;
        int answer;
};

/* The list for "struct ccs_query_entry". */
static LIST_HEAD(ccs_query_list);

/* Number of "struct file" referring /proc/ccs/query interface. */
static atomic_t ccs_query_observers = ATOMIC_INIT(0);

static void ccs_addprintf(char *buffer, int len, const char *fmt, ...)
{
        va_list args;
        const int pos = strlen(buffer);
        va_start(args, fmt);
        vsnprintf(buffer + pos, len - pos - 1, fmt, args);
        va_end(args);
}

static void ccs_truncate(char *str)
{
        while (* (unsigned char *) str > (unsigned char) ' ')
                str++;
        *str = '\0';
}

/**
 * ccs_supervisor - Ask for the supervisor's decision.
 *
 * @r:   Pointer to "struct ccs_request_info".
 * @fmt: The printf()'s format string, followed by parameters.
 *
 * Returns 0 if the supervisor decided to permit the access request which
 * violated the policy in enforcing mode, CCS_RETRY_REQUEST if the supervisor
 * decided to retry the access request which violated the policy in enforcing
 * mode, 0 if it is not in enforcing mode, -EPERM otherwise.
 */
int ccs_supervisor(struct ccs_request_info *r, const char *fmt, ...)
{
        va_list args;
        int error = -EPERM;
        int pos;
        int len;
        static unsigned int ccs_serial;
        struct ccs_query_entry *ccs_query_entry = NULL;
        bool quota_exceeded = false;
        char *header;
        struct ccs_domain_info * const domain = ccs_current_domain();
        va_start(args, fmt);
        len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 80;
        va_end(args);
        if (r->mode == CCS_CONFIG_LEARNING) {
                char *buffer;
                char *realpath = NULL;
                char *argv0 = NULL;
                char *symlink = NULL;
                char *handler = NULL;
                const struct ccs_preference *pref;
                if (!ccs_domain_quota_ok(r))
                        return 0;
                header = ccs_init_log(&len, r);
                if (!header)
                        return 0;
                pref = ccs_profile(r->profile)->learning;
                /* strstr() will return NULL if ordering is wrong. */
                if (r->param_type == CCS_TYPE_PATH_ACL &&
                    r->param.path.operation == CCS_TYPE_EXECUTE) {
                        if (pref->learning_exec_argv0) {
                                argv0 = strstr(header, " argv[]={ \"");
                                if (argv0) {
                                        argv0 += 10;
                                        ccs_truncate(argv0);
                                }
                        }
                        if (pref->learning_exec_realpath) {
                                realpath = strstr(header,
                                                  " exec={ realpath=\"");
                                if (realpath) {
                                        realpath += 8;
                                        ccs_truncate(realpath);
                                }
                        }
                } else if (r->param_type == CCS_TYPE_PATH_ACL &&
                           r->param.path.operation == CCS_TYPE_SYMLINK &&
                           pref->learning_symlink_target) {
                        symlink = strstr(header, " symlink.target=\"");
                        if (symlink)
                                ccs_truncate(symlink + 1);
                }
                handler = strstr(header, "type=execute_handler");
                if (handler)
                        ccs_truncate(handler);
                buffer = kmalloc(len, CCS_GFP_FLAGS);
                if (buffer) {
                        va_start(args, fmt);
                        vsnprintf(buffer, len - 1, fmt, args);
                        va_end(args);
                        if (handler || realpath || argv0 || symlink) {
                                ccs_addprintf(buffer, len, " if");
                                if (handler)
                                        ccs_addprintf(buffer, len, " task.%s",
                                                      handler);
                                if (realpath)
                                        ccs_addprintf(buffer, len, " exec.%s",
                                                      realpath);
                                if (argv0)
                                        ccs_addprintf(buffer, len,
                                                      " exec.argv[0]=%s",
                                                      argv0);
                                if (symlink)
                                        ccs_addprintf(buffer, len, "%s",
                                                      symlink);
                        }
                        ccs_normalize_line(buffer);
                        ccs_write_domain2(buffer, domain, false);
                        kfree(buffer);
                }
                kfree(header);
                return 0;
        }
        if (r->mode != CCS_CONFIG_ENFORCING)
                return 0;
        if (!atomic_read(&ccs_query_observers)) {
                int i;
                if (current->ccs_flags & CCS_DONT_SLEEP_ON_ENFORCE_ERROR)
                        return -EPERM;
                for (i = 0; i < ccs_profile(domain->profile)->enforcing->
                             enforcing_penalty; i++) {
                        set_current_state(TASK_INTERRUPTIBLE);
                        schedule_timeout(HZ / 10);
                }
                return -EPERM;
        }
        header = ccs_init_log(&len, r);
        if (!header)
                goto out;
        ccs_query_entry = kzalloc(sizeof(*ccs_query_entry), CCS_GFP_FLAGS);
        if (!ccs_query_entry)
                goto out;
        len = ccs_round2(len);
        ccs_query_entry->query = kzalloc(len, CCS_GFP_FLAGS);
        if (!ccs_query_entry->query)
                goto out;
        INIT_LIST_HEAD(&ccs_query_entry->list);
        spin_lock(&ccs_query_list_lock);
        if (ccs_quota_for_query && ccs_query_memory_size + len +
            sizeof(*ccs_query_entry) >= ccs_quota_for_query) {
                quota_exceeded = true;
        } else {
                ccs_query_memory_size += len + sizeof(*ccs_query_entry);
                ccs_query_entry->serial = ccs_serial++;
        }
        spin_unlock(&ccs_query_list_lock);
        if (quota_exceeded)
                goto out;
        snprintf(ccs_query_entry->query, len - 1, "Q%u-%hu\n%s",
                 ccs_query_entry->serial, r->retry, header);
        kfree(header);
        header = NULL;
        ccs_addprintf(ccs_query_entry->query, len, fmt, args);
        ccs_query_entry->query_len = strlen(ccs_query_entry->query) + 1;
        spin_lock(&ccs_query_list_lock);
        list_add_tail(&ccs_query_entry->list, &ccs_query_list);
        spin_unlock(&ccs_query_list_lock);
        /* Give 10 seconds for supervisor's opinion. */
        for (ccs_query_entry->timer = 0;
             atomic_read(&ccs_query_observers) && ccs_query_entry->timer < 100;
             ccs_query_entry->timer++) {
                wake_up(&ccs_query_wait);
                set_current_state(TASK_INTERRUPTIBLE);
                schedule_timeout(HZ / 10);
                if (ccs_query_entry->answer)
                        break;
        }
        spin_lock(&ccs_query_list_lock);
        list_del(&ccs_query_entry->list);
        ccs_query_memory_size -= len + sizeof(*ccs_query_entry);
        spin_unlock(&ccs_query_list_lock);
        switch (ccs_query_entry->answer) {
        case 3: /* Asked to retry by administrator. */
                error = CCS_RETRY_REQUEST;
                r->retry++;
                break;
        case 1:
                /* Granted by administrator. */
                error = 0;
                break;
        case 0:
                /* Timed out. */
                break;
        default:
                /* Rejected by administrator. */
                break;
        }
 out:
        if (ccs_query_entry)
                kfree(ccs_query_entry->query);
        kfree(ccs_query_entry);
        kfree(header);
        return error;
}

/**
 * ccs_poll_query - poll() for /proc/ccs/query.
 *
 * @file: Pointer to "struct file".
 * @wait: Pointer to "poll_table".
 *
 * Returns POLLIN | POLLRDNORM when ready to read, 0 otherwise.
 *
 * Waits for access requests which violated policy in enforcing mode.
 */
static int ccs_poll_query(struct file *file, poll_table *wait)
{
        struct list_head *tmp;
        bool found = false;
        u8 i;
        for (i = 0; i < 2; i++) {
                spin_lock(&ccs_query_list_lock);
                list_for_each(tmp, &ccs_query_list) {
                        struct ccs_query_entry *ptr =
                                list_entry(tmp, struct ccs_query_entry, list);
                        if (ptr->answer)
                                continue;
                        found = true;
                        break;
                }
                spin_unlock(&ccs_query_list_lock);
                if (found)
                        return POLLIN | POLLRDNORM;
                if (i)
                        break;
                poll_wait(file, &ccs_query_wait, wait);
        }
        return 0;
}

/**
 * ccs_read_query - Read access requests which violated policy in enforcing mode.
 *
 * @head: Pointer to "struct ccs_io_buffer".
 */
static void ccs_read_query(struct ccs_io_buffer *head)
{
        struct list_head *tmp