Initial Contribution

1 files changed, 186 insertions, 0 deletions

diff --git a/libnetutils/dhcp_utils.c b/libnetutils/dhcp_utils.c
new file mode 100644
index 000000000..97fe76dd3
--- /dev/null
+++ b/libnetutils/dhcp_utils.c
@@ -0,0 +1,186 @@
+/*
+ * Copyright 2008, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); 
+ * you may not use this file except in compliance with the License. 
+ * You may obtain a copy of the License at 
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0 
+ *
+ * Unless required by applicable law or agreed to in writing, software 
+ * distributed under the License is distributed on an "AS IS" BASIS, 
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
+ * See the License for the specific language governing permissions and 
+ * limitations under the License.
+ */
+
+/* Utilities for managing the dhcpcd DHCP client daemon */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include <cutils/properties.h>
+
+static const char DAEMON_NAME[]       = "dhcpcd";
+static const char DAEMON_PROP_NAME[]  = "init.svc.dhcpcd";
+static const char DHCP_PROP_NAME_PREFIX[]  = "dhcp";
+static const int  NAP_TIME = 1;   /* wait for 1 second at a time */
+                                  /* when polling for property values */
+static char errmsg[100];
+
+/*
+ * Wait for a system property to be assigned a specified value.
+ * If desired_value is NULL, then just wait for the property to
+ * be created with any value. maxwait is the maximum amount of
+ * time in seconds to wait before giving up.
+ */
+static int wait_for_property(const char *name, const char *desired_value, int maxwait)
+{
+    char value[PROPERTY_VALUE_MAX] = {'\0'};
+    int maxnaps = maxwait / NAP_TIME;
+
+    if (maxnaps < 1) {
+        maxnaps = 1;
+    }
+
+    while (maxnaps-- > 0) {
+        usleep(1000000);
+        if (property_get(name, value, NULL)) {
+            if (desired_value == NULL || 
+                    strcmp(value, desired_value) == 0) {
+                return 0;
+            }
+        }
+    }
+    return -1; /* failure */
+}
+
+static void fill_ip_info(const char *interface,
+                     in_addr_t *ipaddr,
+                     in_addr_t *gateway,
+                     in_addr_t *mask,
+                     in_addr_t *dns1,
+                     in_addr_t *dns2,
+                     in_addr_t *server,
+                     uint32_t  *lease)
+{
+    char prop_name[PROPERTY_KEY_MAX];
+    char prop_value[PROPERTY_VALUE_MAX];
+    struct in_addr addr;
+    in_addr_t iaddr;
+
+    snprintf(prop_name, sizeof(prop_name), "%s.%s.ipaddress", DHCP_PROP_NAME_PREFIX, interface);
+    if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
+        *ipaddr = addr.s_addr;
+    } else {
+        *ipaddr = 0;
+    }
+    snprintf(prop_name, sizeof(prop_name), "%s.%s.gateway", DHCP_PROP_NAME_PREFIX, interface);
+    if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
+        *gateway = addr.s_addr;
+    } else {
+        *gateway = 0;
+    }
+    snprintf(prop_name, sizeof(prop_name), "%s.%s.mask", DHCP_PROP_NAME_PREFIX, interface);
+    if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
+        *mask = addr.s_addr;
+    } else {
+        *mask = 0;
+    }
+    snprintf(prop_name, sizeof(prop_name), "%s.%s.dns1", DHCP_PROP_NAME_PREFIX, interface);
+    if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
+        *dns1 = addr.s_addr;
+    } else {
+        *dns1 = 0;
+    }
+    snprintf(prop_name, sizeof(prop_name), "%s.%s.dns2", DHCP_PROP_NAME_PREFIX, interface);
+    if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
+        *dns2 = addr.s_addr;
+    } else {
+        *dns2 = 0;
+    }
+    snprintf(prop_name, sizeof(prop_name), "%s.%s.server", DHCP_PROP_NAME_PREFIX, interface);
+    if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
+        *server = addr.s_addr;
+    } else {
+        *server = 0;
+    }
+    snprintf(prop_name, sizeof(prop_name), "%s.%s.leasetime", DHCP_PROP_NAME_PREFIX, interface);
+    if (property_get(prop_name, prop_value, NULL)) {
+        *lease = atol(prop_value);
+    }
+}
+
+/*
+ * Start the dhcp client daemon, and wait for it to finish
+ * configuring the interface.
+ */
+int dhcp_do_request(const char *interface,
+                    in_addr_t *ipaddr,
+                    in_addr_t *gateway,
+                    in_addr_t *mask,
+                    in_addr_t *dns1,
+                    in_addr_t *dns2,
+                    in_addr_t *server,
+                    uint32_t  *lease)
+{
+    char result_prop_name[PROPERTY_KEY_MAX];
+    char prop_value[PROPERTY_VALUE_MAX] = {'\0'};
+    const char *ctrl_prop = "ctl.start";
+    const char *desired_status = "running";
+
+    snprintf(result_prop_name, sizeof(result_prop_name), "%s.%s.result",
+            DHCP_PROP_NAME_PREFIX,
+            interface);
+    /* Erase any previous setting of the dhcp result property */
+    property_set(result_prop_name, "");
+
+    /* Start the daemon and wait until it's ready */
+    property_set(ctrl_prop, DAEMON_NAME);
+    if (wait_for_property(DAEMON_PROP_NAME, desired_status, 10) < 0) {
+        snprintf(errmsg, sizeof(errmsg), "%s", "Timed out waiting for dhcpcd to start");
+        return -1;
+    }
+
+    /* Wait for the daemon to return a result */
+    if (wait_for_property(result_prop_name, NULL, 30) < 0) {
+        snprintf(errmsg, sizeof(errmsg), "%s", "Timed out waiting for DHCP to finish");
+        return -1;
+    }
+
+    if (!property_get(result_prop_name, prop_value, NULL)) {
+        /* shouldn't ever happen, given the success of wait_for_property() */
+        snprintf(errmsg, sizeof(errmsg), "%s", "DHCP result property was not set");
+        return -1;
+    }
+    if (strcmp(prop_value, "ok") == 0) {
+        fill_ip_info(interface, ipaddr, gateway, mask, dns1, dns2, server, lease);
+        return 0;
+    } else {
+        snprintf(errmsg, sizeof(errmsg), "DHCP result was %s", prop_value);
+        return -1;
+    }
+}
+
+/**
+ * Stop the DHCP client daemon.
+ */
+int dhcp_stop(const char *interface)
+{
+    const char *ctrl_prop = "ctl.stop";
+    const char *desired_status = "stopped";
+
+    /* Stop the daemon and wait until it's reported to be stopped */
+    property_set(ctrl_prop, DAEMON_NAME);
+    if (wait_for_property(DAEMON_PROP_NAME, desired_status, 5) < 0) {
+        return -1;
+    }
+    return 0;
+}
+
+char *dhcp_get_errmsg() {
+    return errmsg;
+}