[systemd-devel] [PATCH 02/28] dhcp: Add DHCP client initialization

[Patrik Flykt]

Provide functionality for initializing a DHCP client struct, setting
interface index, last used address and additional options to request.
On initialization the most useful options are added by default.
---
 src/dhcp/client.c |  137 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/dhcp/client.h |   34 +++++++++++++
 2 files changed, 171 insertions(+)
 create mode 100644 src/dhcp/client.c
 create mode 100644 src/dhcp/client.h

diff --git a/src/dhcp/client.c b/src/dhcp/client.c
new file mode 100644
index 0000000..172ddd9
--- /dev/null
+++ b/src/dhcp/client.c
@@ -0,0 +1,137 @@
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2013 Intel Corporation. All rights reserved.
+
+  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 "util.h"
+#include "list.h"
+
+#include "protocol.h"
+#include "client.h"
+
+struct DHCPClient {
+        DHCPState state;
+        int index;
+        uint8_t *req_opts;
+        int req_opts_size;
+        struct in_addr *last_addr;
+};
+
+static uint8_t default_req_opts[] = {
+        DHCP_OPTION_SUBNET_MASK,
+        DHCP_OPTION_ROUTER,
+        DHCP_OPTION_HOST_NAME,
+        DHCP_OPTION_DOMAIN_NAME,
+        DHCP_OPTION_DOMAIN_NAME_SERVER,
+        DHCP_OPTION_NTP_SERVER,
+};
+
+int dhcp_client_set_request_option(DHCPClient *client, uint8_t option)
+{
+        int i;
+
+        if (!client)
+                return -EINVAL;
+
+        if (client->state != DHCP_STATE_INIT)
+                return -EBUSY;
+
+        switch(option) {
+        case DHCP_OPTION_PAD:
+        case DHCP_OPTION_OVERLOAD:
+        case DHCP_OPTION_MESSAGE_TYPE:
+        case DHCP_OPTION_PARAMETER_REQUEST_LIST:
+        case DHCP_OPTION_END:
+                return -EINVAL;
+
+        default:
+                break;
+        }
+
+        for (i = 0; i < client->req_opts_size; i++)
+                if (client->req_opts[i] == option)
+                        return -EEXIST;
+
+        client->req_opts_size++;
+        client->req_opts = realloc(client->req_opts, client->req_opts_size);
+        if (!client->req_opts) {
+                client->req_opts_size = 0;
+                return -ENOBUFS;
+        }
+
+        client->req_opts[client->req_opts_size - 1] = option;
+
+        return 0;
+}
+
+int dhcp_client_set_request_address(DHCPClient *client,
+                struct in_addr *last_addr)
+{
+        if (!client)
+                return -EINVAL;
+
+        if (client->state != DHCP_STATE_INIT)
+                return -EBUSY;
+
+        client->last_addr = malloc(sizeof(struct in_addr));
+        if (!client->last_addr)
+                return -ENOBUFS;
+
+        memcpy(&client->last_addr, last_addr, sizeof(struct in_addr));
+
+        return 0;
+}
+
+int dhcp_client_set_index(DHCPClient *client, int interface_index)
+{
+        if (!client || interface_index < -1)
+                return -EINVAL;
+
+        if (client->state != DHCP_STATE_INIT)
+                return -EBUSY;
+
+        client->index = interface_index;
+
+        return 0;
+}
+
+DHCPClient *dhcp_client_new(void)
+{
+        DHCPClient *client;
+        int i;
+
+        client = new0(DHCPClient, 1);
+        if (!client)
+                return NULL;
+
+        client->state = DHCP_STATE_INIT;
+        client->index = -1;
+
+        client->req_opts_size = sizeof(default_req_opts)
+                / sizeof(default_req_opts[0]);
+
+        client->req_opts = malloc(client->req_opts_size);
+        for (i = 0; i < client->req_opts_size; i++)
+                client->req_opts[i] = default_req_opts[i];
+
+        return client;
+}
diff --git a/src/dhcp/client.h b/src/dhcp/client.h
new file mode 100644
index 0000000..447c03b
--- /dev/null
+++ b/src/dhcp/client.h
@@ -0,0 +1,34 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2013 Intel Corporation. All rights reserved.
+
+  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 <netinet/in.h>
+
+struct DHCPClient;
+typedef struct DHCPClient DHCPClient;
+
+int dhcp_client_set_request_option(DHCPClient *client, uint8_t option);
+int dhcp_client_set_request_address(DHCPClient *client,
+                                    struct in_addr *last_address);
+int dhcp_client_set_index(DHCPClient *client, int interface_index);
+
+DHCPClient *dhcp_client_new(void);
-- 
1.7.10.4