sd-dhcp-client: split sd_dhcp_lease from sd_dhcp_client

This allows us users of the library to keep copies of old leases. This is
used by networkd to know what addresses to drop (if any) when the lease
expires.

In the future this may be used by DNAv4 and sd-dhcp-server.

1 files changed, 244 insertions, 0 deletions

diff --git a/src/libsystemd-dhcp/dhcp-lease.c b/src/libsystemd-dhcp/dhcp-lease.c
new file mode 100644
index 0000000000..c1f76aa561
--- /dev/null
+++ b/src/libsystemd-dhcp/dhcp-lease.c
@@ -0,0 +1,244 @@
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2013 Intel Corporation. All rights reserved.
+  Copyright (C) 2014 Tom Gundersen
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <net/ethernet.h>
+#include <sys/param.h>
+
+#include "util.h"
+#include "list.h"
+
+#include "dhcp-protocol.h"
+#include "dhcp-internal.h"
+#include "dhcp-lease.h"
+#include "sd-dhcp-client.h"
+
+int sd_dhcp_lease_get_address(sd_dhcp_lease *lease, struct in_addr *addr) {
+        assert_return(lease, -EINVAL);
+        assert_return(addr, -EINVAL);
+
+        addr->s_addr = lease->address;
+
+        return 0;
+}
+
+int sd_dhcp_lease_get_mtu(sd_dhcp_lease *lease, uint16_t *mtu) {
+        assert_return(lease, -EINVAL);
+        assert_return(mtu, -EINVAL);
+
+        if (lease->mtu)
+                *mtu = lease->mtu;
+        else
+                return -ENOENT;
+
+        return 0;
+}
+
+int sd_dhcp_lease_get_dns(sd_dhcp_lease *lease, struct in_addr **addr, size_t *addr_size) {
+        assert_return(lease, -EINVAL);
+        assert_return(addr, -EINVAL);
+        assert_return(addr_size, -EINVAL);
+
+        if (lease->dns_size) {
+                *addr_size = lease->dns_size;
+                *addr = lease->dns;
+        } else
+                return -ENOENT;
+
+        return 0;
+}
+
+int sd_dhcp_lease_get_domainname(sd_dhcp_lease *lease, const char **domainname) {
+        assert_return(lease, -EINVAL);
+        assert_return(domainname, -EINVAL);
+
+        if (lease->domainname)
+                *domainname = lease->domainname;
+        else
+                return -ENOENT;
+
+        return 0;
+}
+
+int sd_dhcp_lease_get_hostname(sd_dhcp_lease *lease, const char **hostname) {
+        assert_return(lease, -EINVAL);
+        assert_return(hostname, -EINVAL);
+
+        if (lease->hostname)
+                *hostname = lease->hostname;
+        else
+                return -ENOENT;
+
+        return 0;
+}
+
+int sd_dhcp_lease_get_router(sd_dhcp_lease *lease, struct in_addr *addr) {
+        assert_return(lease, -EINVAL);
+        assert_return(addr, -EINVAL);
+
+        addr->s_addr = lease->router;
+
+        return 0;
+}
+
+int sd_dhcp_lease_get_netmask(sd_dhcp_lease *lease, struct in_addr *addr) {
+        assert_return(lease, -EINVAL);
+        assert_return(addr, -EINVAL);
+
+        addr->s_addr = lease->subnet_mask;
+
+        return 0;
+}
+
+sd_dhcp_lease *sd_dhcp_lease_ref(sd_dhcp_lease *lease) {
+        if (lease)
+                assert_se(REFCNT_INC(lease->n_ref) >= 2);
+
+        return lease;
+}
+
+sd_dhcp_lease *sd_dhcp_lease_unref(sd_dhcp_lease *lease) {
+        if (lease && REFCNT_DEC(lease->n_ref) <= 0) {
+                free(lease->hostname);
+                free(lease->domainname);
+                free(lease->dns);
+                free(lease);
+        }
+
+        return NULL;
+}
+
+int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option,
+                              void *user_data) {
+        sd_dhcp_lease *lease = user_data;
+        be32_t val;
+
+        switch(code) {
+
+        case DHCP_OPTION_IP_ADDRESS_LEASE_TIME:
+                if (len == 4) {
+                        memcpy(&val, option, 4);
+                        lease->lifetime = be32toh(val);
+                }
+
+                break;
+
+        case DHCP_OPTION_SERVER_IDENTIFIER:
+                if (len >= 4)
+                        memcpy(&lease->server_address, option, 4);
+
+                break;
+
+        case DHCP_OPTION_SUBNET_MASK:
+                if (len >= 4)
+                        memcpy(&lease->subnet_mask, option, 4);
+
+                break;
+
+        case DHCP_OPTION_ROUTER:
+                if (len >= 4)
+                        memcpy(&lease->router, option, 4);
+
+                break;
+
+        case DHCP_OPTION_DOMAIN_NAME_SERVER:
+                if (len && !(len % 4)) {
+                        unsigned i;
+
+                        lease->dns_size = len / 4;
+
+                        free(lease->dns);
+                        lease->dns = new0(struct in_addr, lease->dns_size);
+                        if (!lease->dns)
+                                return -ENOMEM;
+
+                        for (i = 0; i < lease->dns_size; i++) {
+                                memcpy(&lease->dns[i].s_addr, option + 4 * i, 4);
+                        }
+                }
+
+                break;
+
+        case DHCP_OPTION_INTERFACE_MTU:
+                if (len >= 2) {
+                        be16_t mtu;
+
+                        memcpy(&mtu, option, 2);
+                        lease->mtu = be16toh(mtu);
+
+                        if (lease->mtu < 68)
+                                lease->mtu = 0;
+                }
+
+                break;
+
+        case DHCP_OPTION_DOMAIN_NAME:
+                if (len >= 1) {
+                        free(lease->domainname);
+                        lease->domainname = strndup((const char *)option, len);
+                }
+
+                break;
+
+        case DHCP_OPTION_HOST_NAME:
+                if (len >= 1) {
+                        free(lease->hostname);
+                        lease->hostname = strndup((const char *)option, len);
+                }
+
+                break;
+
+        case DHCP_OPTION_RENEWAL_T1_TIME:
+                if (len == 4) {
+                        memcpy(&val, option, 4);
+                        lease->t1 = be32toh(val);
+                }
+
+                break;
+
+        case DHCP_OPTION_REBINDING_T2_TIME:
+                if (len == 4) {
+                        memcpy(&val, option, 4);
+                        lease->t2 = be32toh(val);
+                }
+
+                break;
+        }
+
+        return 0;
+}
+
+int dhcp_lease_new(sd_dhcp_lease **ret) {
+        _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
+
+        lease = new0(sd_dhcp_lease, 1);
+        if (!lease)
+                return -ENOMEM;
+
+        lease->n_ref = REFCNT_INIT;
+
+        *ret = lease;
+        lease = NULL;
+
+        return 0;
+}