security/ccsecurity/network.c

/*
 * fs/tomoyo_network.c
 *
 * Implementation of the Domain-Based Mandatory Access Control.
 *
 * Copyright (C) 2005-2007  NTT DATA CORPORATION
 *
 * Version: 1.5.0   2007/09/20
 *
 * This file is applicable to both 2.4.30 and 2.6.11 and later.
 * See README.ccs for ChangeLog.
 *
 */
/***** TOMOYO Linux start. *****/

#include <linux/ccs_common.h>
#include <linux/tomoyo.h>
#include <linux/realpath.h>
#include <net/ip.h>

/*************************  VARIABLES  *************************/

extern struct semaphore domain_acl_lock;

/*************************  AUDIT FUNCTIONS  *************************/

static int AuditNetworkLog(const u8 is_ipv6, const char *operation, const u32 *address, const u16 port, const u8 is_granted)
{
        char *buf;
        int len = 256;
        if (CanSaveAuditLog(is_granted) < 0) return -ENOMEM;
        if ((buf = InitAuditLog(&len)) == NULL) return -ENOMEM;
        snprintf(buf + strlen(buf), len - strlen(buf) - 1, KEYWORD_ALLOW_NETWORK "%s ", operation);
        if (is_ipv6) {
                print_ipv6(buf + strlen(buf), len - strlen(buf), (const u16 *) address);
        } else {
                u32 ip = *address;
                snprintf(buf + strlen(buf), len - strlen(buf) - 1, "%u.%u.%u.%u", NIPQUAD(ip));
        }
        snprintf(buf + strlen(buf), len - strlen(buf) - 1, " %u\n", port);
        return WriteAuditLog(buf, is_granted);
}

/*************************  ADDRESS GROUP HANDLER  *************************/

static struct address_group_entry *group_list = NULL;

static int AddAddressGroupEntry(const char *group_name, const u8 is_ipv6, const u16 *min_address, const u16 *max_address, const u8 is_delete)
{
        static DECLARE_MUTEX(lock);
        struct address_group_entry *new_group, *group;
        struct address_group_member *new_member, *member;
        const struct path_info *saved_group_name;
        int error = -ENOMEM;
        if (!IsCorrectPath(group_name, 0, 0, 0, __FUNCTION__) || !group_name[0]) return -EINVAL;
        if ((saved_group_name = SaveName(group_name)) == NULL) return -ENOMEM;
        down(&lock);
        for (group = group_list; group; group = group->next) {
                if (saved_group_name != group->group_name) continue;
                for (member = group->first_member; member; member = member->next) {
                        if (member->is_ipv6 != is_ipv6) continue;
                        if (is_ipv6) {
                                if (memcmp(member->min.ipv6, min_address, 16) || memcmp(member->max.ipv6, max_address, 16)) continue;
                        } else {
                                if (member->min.ipv4 != * (u32 *) min_address || member->max.ipv4 != * (u32 *) max_address) continue;
                        }
                        member->is_deleted = is_delete;
                        error = 0;
                        goto out;
                }
                break;
        }
        if (is_delete) {
                error = -ENOENT;
                goto out;
        }
        if (!group) {
                if ((new_group = alloc_element(sizeof(*new_group))) == NULL) goto out;
                new_group->group_name = saved_group_name;
                mb(); /* Instead of using spinlock. */
                if ((group = group_list) != NULL) {
                        while (group->next) group = group->next; group->next = new_group;
                } else {
                        group_list= new_group;
                }
                group = new_group;
        }
        if ((new_member = alloc_element(sizeof(*new_member))) == NULL) goto out;
        new_member->is_ipv6 = is_ipv6;
        if (is_ipv6) {
                memmove(new_member->min.ipv6, min_address, 16);
                memmove(new_member->max.ipv6, max_address, 16);
        } else {
                new_member->min.ipv4 = * (u32 *) min_address;
                new_member->max.ipv4 = * (u32 *) max_address;
        }
        mb(); /* Instead of using spinlock. */
        if ((member = group->first_member) != NULL) {
                while (member->next) member = member->next; member->next = new_member;
        } else {
                group->first_member = new_member;
        }
        error = 0;
 out:
        up(&lock);
        return error;
}

int AddAddressGroupPolicy(char *data, const u8 is_delete)
{
        int count, is_ipv6;
        u16 min_address[8], max_address[8];
        char *cp = strchr(data, ' ');
        if (!cp) return -EINVAL;
        *cp++ = '\0';
        if ((count = sscanf(cp, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx-%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
                                                &min_address[0], &min_address[1], &min_address[2], &min_address[3],
                                                &min_address[4], &min_address[5], &min_address[6], &min_address[7],
                                                &max_address[0], &max_address[1], &max_address[2], &max_address[3],
                                                &max_address[4], &max_address[5], &max_address[6], &max_address[7])) == 8 || count == 16) {
                int i;
                for (i = 0; i < 8; i++) {
                        min_address[i] = htons(min_address[i]);
                        max_address[i] = htons(max_address[i]);
                }
                if (count == 8) memmove(max_address, min_address, sizeof(min_address));
                is_ipv6 = 1;
        } else if ((count = sscanf(cp, "%hu.%hu.%hu.%hu-%hu.%hu.%hu.%hu",
                                                           &min_address[0], &min_address[1], &min_address[2], &min_address[3],
                                                           &max_address[0], &max_address[1], &max_address[2], &max_address[3])) == 4 || count == 8) {
                u32 ip = ((((u8) min_address[0]) << 24) + (((u8) min_address[1]) << 16) + (((u8) min_address[2]) << 8) + (u8) min_address[3]);
                * (u32 *) min_address = ip;
                if (count == 8) ip = ((((u8) max_address[0]) << 24) + (((u8) max_address[1]) << 16) + (((u8) max_address[2]) << 8) + (u8) max_address[3]);
                * (u32 *) max_address = ip;
                is_ipv6 = 0;
        } else {
                return -EINVAL;
        }
        return AddAddressGroupEntry(data, is_ipv6, min_address, max_address, is_delete);
}

static struct address_group_entry *FindOrAssignNewAddressGroup(const char *group_name)
{
        int i;
        struct address_group_entry *group;
        for (i = 0; i <= 1; i++) {
                for (group = group_list; group; group = group->next) {
                        if (strcmp(group_name, group->group_name->name) == 0) return group;
                }
                if (i == 0) {
                        const u16 dummy[2] = { 0, 0 };
                        AddAddressGroupEntry(group_name, 0, dummy, dummy, 0);
                        AddAddressGroupEntry(group_name, 0, dummy, dummy, 1);
                }
        }
        return NULL;
}

static int AddressMatchesToGroup(const u8 is_ipv6, const u32 *address, const struct address_group_entry *group)
{
        struct address_group_member *member;
        const u32 ip = ntohl(*address);
        for (member = group->first_member; member; member = member->next) {
                if (member->is_deleted) continue;
                if (member->is_ipv6) {
                        if (is_ipv6 && memcmp(member->min.ipv6, address, 16) <= 0 && memcmp(address, member->max.ipv6, 16) <= 0) return 1;
                } else {
                        if (!is_ipv6 && member->min.ipv4 <= ip && ip <= member->max.ipv4) return 1;
                }
        }
        return 0;
}

int ReadAddressGroupPolicy(struct io_buffer *head)
{
        struct address_group_entry *group = head->read_var1;
        struct address_group_member *member = head->read_var2;
        if (!group) group = group_list;
        while (group) {
                head->read_var1 = group;
                if (!member) member = group->first_member;
                while (member) {
                        head->read_var2 = member;
                        if (!member->is_deleted) {
                                char buf[128];
                                if (member->is_ipv6) {
                                        const u16 *min_address = member->min.ipv6, *max_address = member->max.ipv6;
                                        print_ipv6(buf, sizeof(buf), min_address);
                                        if (memcmp(min_address, max_address, 16)) {
                                                char *cp = strchr(buf, '\0');
                                                *cp++ = '-';
                                                print_ipv6(cp, sizeof(buf) - strlen(buf), max_address);
                                        }
                                } else {
                                        const u32 min_address = member->min.ipv4, max_address = member->max.ipv4;
                                        memset(buf, 0, sizeof(buf));
                                        snprintf(buf, sizeof(buf) - 1, "%u.%u.%u.%u", HIPQUAD(min_address));
                                        if (min_address != max_address) {
                                                const int len = strlen(buf);
                                                snprintf(buf + len, sizeof(buf) - 1 - len, "-%u.%u.%u.%u", HIPQUAD(max_address));
                                        }
                                }
                                if (io_printf(head, KEYWORD_ADDRESS_GROUP "%s %s\n", group->group_name->name, buf)) break;
                        }
                        member = member->next;
                }
                if (member) break;
                head->read_var2 = NULL;
                group = group->next;
        }
        return group ? -ENOMEM : 0;
}

/*************************  NETWORK NETWORK ACL HANDLER  *************************/

char *print_ipv6(char *buffer, const int buffer_len, const u16 *ip)
{
        memset(buffer, 0, buffer_len);
        snprintf(buffer, buffer_len - 1, "%x:%x:%x:%x:%x:%x:%x:%x", ntohs(ip[0]), ntohs(ip[1]), ntohs(ip[2]), ntohs(ip[3]), ntohs(ip[4]), ntohs(ip[5]), ntohs(ip[6]), ntohs(ip[7]));
        return buffer;
}

const char *network2keyword(const unsigned int operation)
{
        const char *keyword = "unknown";
        switch (operation) {
        case NETWORK_ACL_UDP_BIND:
                keyword = "UDP bind";
                break;
        case NETWORK_ACL_UDP_CONNECT:
                keyword = "UDP connect";
                break;
        case NETWORK_ACL_TCP_BIND:
                keyword = "TCP bind";
                break;
        case NETWORK_ACL_TCP_LISTEN:
                keyword = "TCP listen";
                break;
        case NETWORK_ACL_TCP_CONNECT:
                keyword = "TCP connect";
                break;
        case NETWORK_ACL_TCP_ACCEPT:
                keyword = "TCP accept";
                break;
        case NETWORK_ACL_RAW_BIND:
                keyword = "RAW bind";
                break;
        case NETWORK_ACL_RAW_CONNECT:
                keyword = "RAW connect";
                break;
        }
        return keyword;
}

static int AddNetworkEntry(const u8 operation, const u8 record_type, const struct address_group_entry *group, const u32 *min_address, const u32 *max_address, const u16 min_port, const u16 max_port, struct domain_info *domain, const u8 is_add, const struct condition_list *condition)
{
        struct acl_info *ptr;
        int error = -ENOMEM;
        const u32 min_ip = ntohl(*min_address), max_ip = ntohl(*max_address); /* using host byte order to allow u32 comparison than memcmp().*/
        if (!domain) return -EINVAL;
        down(&domain_acl_lock);
        if (is_add) {
                if ((ptr = domain->first_acl_ptr) == NULL) goto first_entry;
                while (1) {
                        struct ip_network_acl_record *new_ptr = (struct ip_network_acl_record *) ptr;
                        if (ptr->type == TYPE_IP_NETWORK_ACL && new_ptr->operation_type == operation && new_ptr->record_type == record_type && ptr->cond == condition && new_ptr->min_port == min_port && max_port == new_ptr->max_port) {
                                if (record_type == IP_RECORD_TYPE_ADDRESS_GROUP) {
                                        if (new_ptr->u.group == group) {
                                                ptr->is_deleted = 0;
                                                /* Found. Nothing to do. */
                                                error = 0;
                                                break;
                                        }
                                } else if (record_type == IP_RECORD_TYPE_IPv4) {
                                        if (new_ptr->u.ipv4.min == min_ip && max_ip == new_ptr->u.ipv4.max) {
                                                ptr->is_deleted = 0;
                                                /* Found. Nothing to do. */
                                                error = 0;
                                                break;
                                        }
                                } else if (record_type == IP_RECORD_TYPE_IPv6) {
                                        if (memcmp(new_ptr->u.ipv6.min, min_address, 16) == 0 && memcmp(max_address, new_ptr->u.ipv6.max, 16) == 0) {
                                                ptr->is_deleted = 0;
                                                /* Found. Nothing to do. */
                                                error = 0;
                                                break;
                                        }
                                }
                        }
                        if (ptr->next) {
                                ptr = ptr->next;
                                continue;
                        }
                first_entry: ;
                        /* Not found. Append it to the tail. */
                        if ((new_ptr = alloc_element(sizeof(*new_ptr))) == NULL) break;
                        new_ptr->head.type = TYPE_IP_NETWORK_ACL;
                        new_ptr->operation_type = operation;
                        new_ptr->record_type = record_type;
                        new_ptr->head.cond = condition;
                        if (record_type == IP_RECORD_TYPE_ADDRESS_GROUP) {
                                new_ptr->u.group = group;
                        } else if (record_type == IP_RECORD_TYPE_IPv4) {
                                new_ptr->u.ipv4.min = min_ip;
                                new_ptr->u.ipv4.max = max_ip;
                        } else {
                                memmove(new_ptr->u.ipv6.min, min_address, 16);
                                memmove(new_ptr->u.ipv6.max, max_address, 16);
                        }
                        new_ptr->min_port = min_port;
                        new_ptr->max_port = max_port;
                        error = AddDomainACL(ptr, domain, (struct acl_info *) new_ptr);
                        break;
                }
        } else {
                error = -ENOENT;
                for (ptr = domain->first_acl_ptr; ptr; ptr = ptr->next) {
                        struct ip_network_acl_record *ptr2 = (struct ip_network_acl_record *) ptr;
                        if (ptr->type != TYPE_IP_NETWORK_ACL || ptr->is_deleted || ptr2->operation_type != operation || ptr2->record_type != record_type || ptr->cond != condition || ptr2->min_port != min_port || ptr2->max_port != max_port) continue;
                        if (record_type == IP_RECORD_TYPE_ADDRESS_GROUP) {
                                if (ptr2->u.group != group) continue;
                        } else if (record_type == IP_RECORD_TYPE_IPv4) {
                                if (ptr2->u.ipv4.min != min_ip || max_ip != ptr2->u.ipv4.max) continue;
                        } else if (record_type == IP_RECORD_TYPE_IPv6) {
                                if (memcmp(ptr2->u.ipv6.min, min_address, 16) || memcmp(max_address, ptr2->u.ipv6.max, 16)) continue;
                        }
                        error = DelDomainACL(ptr);
                        break;
                }
        }
        up(&domain_acl_lock);
        return error;
}

static int CheckNetworkEntry(const u8 is_ipv6, const int operation, const u32 *address, const u16 port)
{
        struct domain_info * const domain = current->domain_info;
        struct acl_info *ptr;
        const char *keyword = network2keyword(operation);
        const u8 is_enforce = CheckCCSEnforce(CCS_TOMOYO_MAC_FOR_NETWORK);
        const u32 ip = ntohl(*address); /* using host byte order to allow u32 comparison than memcmp().*/
        if (!CheckCCSFlags(CCS_TOMOYO_MAC_FOR_NETWORK)) return 0;
        for (ptr = domain->first_acl_ptr; ptr; ptr = ptr->next) {
                struct ip_network_acl_record *ptr2 = (struct ip_network_acl_record *) ptr;
                if (ptr->type != TYPE_IP_NETWORK_ACL || ptr->is_deleted || ptr2->operation_type != operation || port < ptr2->min_port || ptr2->max_port < port || CheckCondition(ptr->cond, NULL)) continue;
                if (ptr2->record_type == IP_RECORD_TYPE_ADDRESS_GROUP) {
                        if (AddressMatchesToGroup(is_ipv6, address, ptr2->u.group)) break;
                } else if (ptr2->record_type == IP_RECORD_TYPE_IPv4) {
                        if (!is_ipv6 && ptr2->u.ipv4.min <= ip && ip <= ptr2->u.ipv4.max) break;
                } else {
                        if (is_ipv6 && memcmp(ptr2->u.ipv6.min, address, 16) <= 0 && memcmp(address, ptr2->u.ipv6.max, 16) <= 0) break;
                }
        }
        if (ptr) {
                AuditNetworkLog(is_ipv6, keyword, address, port, 1);
                return 0;
        }
        if (TomoyoVerboseMode()) {
                if (is_ipv6) {
                        char buf[64];
                        print_ipv6(buf, sizeof(buf), (const u16 *) address);
                        printk("TOMOYO-%s: %s to %s %u denied for %s\n", GetMSG(is_enforce), keyword, buf, port, GetLastName(domain));
                } else {
                        printk("TOMOYO-%s: %s to %u.%u.%u.%u %u denied for %s\n", GetMSG(is_enforce), keyword, HIPQUAD(ip), port, GetLastName(domain));
                }
        }
        AuditNetworkLog(is_ipv6, keyword, address, port, 0);
        if (is_enforce) {
                if (is_ipv6) {
                        char buf[64];
                        print_ipv6(buf, sizeof(buf), (const u16 *) address);
                        return CheckSupervisor("%s\n" KEYWORD_ALLOW_NETWORK "%s %s %u\n", domain->domainname->name, keyword, buf, port);
                }
                return CheckSupervisor("%s\n" KEYWORD_ALLOW_NETWORK "%s %u.%u.%u.%u %u\n", domain->domainname->name, keyword, HIPQUAD(ip), port);
        }
        if (CheckCCSAccept(CCS_TOMOYO_MAC_FOR_NETWORK, domain)) AddNetworkEntry(operation, is_ipv6 ? IP_RECORD_TYPE_IPv6: IP_RECORD_TYPE_IPv4, NULL, address, address, port, port, domain, 1, NULL);
        return 0;
}

int AddNetworkPolicy(char *data, struct domain_info *domain, const u8 is_delete)
{
        u8 sock_type, operation, record_type;
        u16 min_address[8], max_address[8];
        struct address_group_entry *group = NULL;
        u16 min_port, max_port;
        int count;
        char *cp1 = NULL, *cp2 = NULL;
        const struct condition_list *condition = NULL;
        cp1 = FindConditionPart(data);
        if (cp1 && (condition = FindOrAssignNewCondition(cp1)) == NULL) goto out;
        if ((cp1 = strchr(data, ' ')) == NULL) goto out; cp1++;
        if (strncmp(data, "TCP ", 4) == 0) sock_type = SOCK_STREAM;
        else if (strncmp(data, "UDP ", 4) == 0) sock_type = SOCK_DGRAM;
        else if (strncmp(data, "RAW ", 4) == 0) sock_type = SOCK_RAW;
        else goto out;
        if ((cp2 = strchr(cp1, ' ')) == NULL) goto out; cp2++;
        if (strncmp(cp1, "bind ", 5) == 0) {
                operation = (sock_type == SOCK_STREAM) ? NETWORK_ACL_TCP_BIND : (sock_type == SOCK_DGRAM) ? NETWORK_ACL_UDP_BIND : NETWORK_ACL_RAW_BIND;
        } else if (strncmp(cp1, "connect ", 8) == 0) {
                operation = (sock_type == SOCK_STREAM) ? NETWORK_ACL_TCP_CONNECT : (sock_type == SOCK_DGRAM) ? NETWORK_ACL_UDP_CONNECT : NETWORK_ACL_RAW_CONNECT;
        } else if (sock_type == SOCK_STREAM && strncmp(cp1, "listen ", 7) == 0) {
                operation = NETWORK_ACL_TCP_LISTEN;
        } else if (sock_type == SOCK_STREAM && strncmp(cp1, "accept ", 7) == 0) {
                operation = NETWORK_ACL_TCP_ACCEPT;
        } else {
                goto out;
        }
        if ((cp1 = strchr(cp2, ' ')) == NULL) goto out; *cp1++ = '\0';
        if ((count = sscanf(cp2, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx-%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
                                                &min_address[0], &min_address[1], &min_address[2], &min_address[3],
                                                &min_address[4], &min_address[5], &min_address[6], &min_address[7],
                                                &max_address[0], &max_address[1], &max_address[2], &max_address[3],
                                                &max_address[4], &max_address[5], &max_address[6], &max_address[7])) == 8 || count == 16) {
                int i;
                for (i = 0; i < 8; i++) {
                        min_address[i] = htons(min_address[i]);
                        max_address[i] = htons(max_address[i]);
                }
                if (count == 8) memmove(max_address, min_address, sizeof(min_address));
                record_type = IP_RECORD_TYPE_IPv6;
        } else if ((count = sscanf(cp2, "%hu.%hu.%hu.%hu-%hu.%hu.%hu.%hu",
                                                           &min_address[0], &min_address[1], &min_address[2], &min_address[3],
                                                           &max_address[0], &max_address[1], &max_address[2], &max_address[3])) == 4 || count == 8) {
                u32 ip = htonl((((u8) min_address[0]) << 24) + (((u8) min_address[1]) << 16) + (((u8) min_address[2]) << 8) + (u8) min_address[3]);
                * (u32 *) min_address = ip;
                if (count == 8) ip = htonl((((u8) max_address[0]) << 24) + (((u8) max_address[1]) << 16) + (((u8) max_address[2]) << 8) + (u8) max_address[3]);
                * (u32 *) max_address = ip;
                record_type = IP_RECORD_TYPE_IPv4;
        } else if (*cp2 == '@') {
                if ((group = FindOrAssignNewAddressGroup(cp2 + 1)) == NULL) return -ENOMEM;
                record_type = IP_RECORD_TYPE_ADDRESS_GROUP;
        } else {
                goto out;
        }
        if (strchr(cp1, ' ')) goto out;
        if ((count = sscanf(cp1, "%hu-%hu", &min_port, &max_port)) == 1 || count == 2) {
                if (count == 1) max_port = min_port;
                return AddNetworkEntry(operation, record_type, group, (u32 *) min_address, (u32 *) max_address, min_port, max_port, domain, is_delete ? 0 : -1, condition);
        }
 out: ;
        return -EINVAL;
}

int CheckNetworkListenACL(const u8 is_ipv6, const u8 *address, const u16 port)
{
        return CheckNetworkEntry(is_ipv6, NETWORK_ACL_TCP_LISTEN, (const u32 *) address, ntohs(port));
}
EXPORT_SYMBOL(CheckNetworkListenACL);

int CheckNetworkConnectACL(const u8 is_ipv6, const int sock_type, const u8 *address, const u16 port)
{
        return CheckNetworkEntry(is_ipv6, sock_type == SOCK_STREAM ? NETWORK_ACL_TCP_CONNECT : (sock_type == SOCK_DGRAM ? NETWORK_ACL_UDP_CONNECT : NETWORK_ACL_RAW_CONNECT), (const u32 *) address, ntohs(port));
}
EXPORT_SYMBOL(CheckNetworkConnectACL);

int CheckNetworkBindACL(const u8 is_ipv6, const int sock_type, const u8 *address, const u16 port)
{
        return CheckNetworkEntry(is_ipv6, sock_type == SOCK_STREAM ? NETWORK_ACL_TCP_BIND : (sock_type == SOCK_DGRAM ? NETWORK_ACL_UDP_BIND : NETWORK_ACL_RAW_BIND), (const u32 *) address, ntohs(port));
}
EXPORT_SYMBOL(CheckNetworkBindACL);

int CheckNetworkAcceptACL(const u8 is_ipv6, const u8 *address, const u16 port)
{
        return CheckNetworkEntry(is_ipv6, NETWORK_ACL_TCP_ACCEPT, (const u32 *) address, ntohs(port));
}
EXPORT_SYMBOL(CheckNetworkAcceptACL);

int CheckNetworkSendMsgACL(const u8 is_ipv6, const int sock_type, const u8 *address, const u16 port)
{
        return CheckNetworkEntry(is_ipv6, sock_type == SOCK_DGRAM ? NETWORK_ACL_UDP_CONNECT : NETWORK_ACL_RAW_CONNECT, (const u32 *) address, ntohs(port));
}
EXPORT_SYMBOL(CheckNetworkSendMsgACL);

int CheckNetworkRecvMsgACL(const u8 is_ipv6, const int sock_type, const u8 *address, const u16 port)
{
        return CheckNetworkEntry(is_ipv6, sock_type == SOCK_DGRAM ? NETWORK_ACL_UDP_CONNECT : NETWORK_ACL_RAW_CONNECT, (const u32 *) address, ntohs(port));
}
EXPORT_SYMBOL(CheckNetworkRecvMsgACL);

/***** TOMOYO Linux end. *****/