libsystemd-dhcp: Add functions for sending unicast UDP messages

[elogind.git] / src / libsystemd-dhcp / dhcp-client.c

diff --git a/src/libsystemd-dhcp/dhcp-client.c b/src/libsystemd-dhcp/dhcp-client.c
index d03435b9298912c7623a1021a2c5c9b651220540..68a3b1a1b64c319db8d186091c88530c4c2f1605 100644 (file)
--- a/src/libsystemd-dhcp/dhcp-client.c
+++ b/src/libsystemd-dhcp/dhcp-client.c
@@ -36,10 +36,10 @@ struct DHCPLease {
         uint32_t t1;
         uint32_t t2;
         uint32_t lifetime;
-        uint32_t address;
-        uint32_t server_address;
-        uint32_t subnet_mask;
-        uint32_t router;
+        be32_t address;
+        be32_t server_address;
+        be32_t subnet_mask;
+        be32_t router;
 };
 
 typedef struct DHCPLease DHCPLease;
@@ -54,7 +54,7 @@ struct sd_dhcp_client {
         sd_event_source *receive_message;
         uint8_t *req_opts;
         size_t req_opts_size;
-        uint32_t last_addr;
+        be32_t last_addr;
         struct ether_addr mac_addr;
         uint32_t xid;
         usec_t start_time;
@@ -63,6 +63,8 @@ struct sd_dhcp_client {
         sd_event_source *timeout_t1;
         sd_event_source *timeout_t2;
         sd_event_source *timeout_expire;
+        sd_dhcp_client_cb_t cb;
+        void *userdata;
         DHCPLease *lease;
 };
 
@@ -75,6 +77,17 @@ static const uint8_t default_req_opts[] = {
         DHCP_OPTION_NTP_SERVER,
 };
 
+int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
+                                void *userdata)
+{
+        assert_return(client, -EINVAL);
+
+        client->cb = cb;
+        client->userdata = userdata;
+
+        return 0;
+}
+
 int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option)
 {
         size_t i;
@@ -143,8 +156,99 @@ int sd_dhcp_client_set_mac(sd_dhcp_client *client,
         return 0;
 }
 
+int sd_dhcp_client_get_address(sd_dhcp_client *client, struct in_addr *addr)
+{
+        assert_return(client, -EINVAL);
+        assert_return(addr, -EINVAL);
+
+        switch (client->state) {
+        case DHCP_STATE_INIT:
+        case DHCP_STATE_SELECTING:
+        case DHCP_STATE_INIT_REBOOT:
+        case DHCP_STATE_REBOOTING:
+        case DHCP_STATE_REQUESTING:
+                return -EADDRNOTAVAIL;
+
+        case DHCP_STATE_BOUND:
+        case DHCP_STATE_RENEWING:
+        case DHCP_STATE_REBINDING:
+                addr->s_addr = client->lease->address;
+
+                break;
+        }
+
+        return 0;
+}
+
+int sd_dhcp_client_get_netmask(sd_dhcp_client *client, struct in_addr *addr)
+{
+        assert_return(client, -EINVAL);
+        assert_return(addr, -EINVAL);
+
+        switch (client->state) {
+        case DHCP_STATE_INIT:
+        case DHCP_STATE_SELECTING:
+        case DHCP_STATE_INIT_REBOOT:
+        case DHCP_STATE_REBOOTING:
+        case DHCP_STATE_REQUESTING:
+                return -EADDRNOTAVAIL;
+
+        case DHCP_STATE_BOUND:
+        case DHCP_STATE_RENEWING:
+        case DHCP_STATE_REBINDING:
+                addr->s_addr = client->lease->subnet_mask;
+
+                break;
+        }
+
+        return 0;
+}
+
+int sd_dhcp_client_prefixlen(const struct in_addr *addr)
+{
+        int len = 0;
+        uint32_t mask;
+
+        assert_return(addr, -EADDRNOTAVAIL);
+
+        mask = be32toh(addr->s_addr);
+        while (mask) {
+                len++;
+                mask = mask << 1;
+        }
+
+        return len;
+}
+
+int sd_dhcp_client_get_router(sd_dhcp_client *client, struct in_addr *addr)
+{
+        assert_return(client, -EINVAL);
+        assert_return(addr, -EINVAL);
+
+        switch (client->state) {
+        case DHCP_STATE_INIT:
+        case DHCP_STATE_SELECTING:
+        case DHCP_STATE_INIT_REBOOT:
+        case DHCP_STATE_REBOOTING:
+        case DHCP_STATE_REQUESTING:
+                return -EADDRNOTAVAIL;
+
+        case DHCP_STATE_BOUND:
+        case DHCP_STATE_RENEWING:
+        case DHCP_STATE_REBINDING:
+                addr->s_addr = client->lease->router;
+
+                break;
+        }
+
+        return 0;
+}
+
 static int client_notify(sd_dhcp_client *client, int event)
 {
+        if (client->cb)
+                client->cb(client, event, client->userdata);
+
         return 0;
 }
 
@@ -169,6 +273,8 @@ static int client_stop(sd_dhcp_client *client, int error)
 
         client->attempt = 1;
 
+        client_notify(client, error);
+
         switch (client->state) {
 
         case DHCP_STATE_INIT:
@@ -276,10 +382,13 @@ static uint16_t client_checksum(void *buf, int len)
 
         if (len & 0x01) {
                 odd = buf;
-                sum += odd[len];
+                sum += odd[len - 1];
         }
 
-        return ~((sum & 0xffff) + (sum >> 16));
+        while (sum >> 16)
+                sum = (sum & 0xffff) + (sum >> 16);
+
+        return ~sum;
 }
 
 static void client_append_ip_headers(DHCPPacket *packet, uint16_t len)
@@ -463,6 +572,10 @@ error:
 static int client_timeout_expire(sd_event_source *s, uint64_t usec,
                                  void *userdata)
 {
+        sd_dhcp_client *client = userdata;
+
+        client_stop(client, DHCP_EVENT_EXPIRED);
+
         return 0;
 }
 
@@ -616,13 +729,20 @@ static int client_receive_ack(sd_dhcp_client *client, DHCPPacket *offer,
 
         lease = new0(DHCPLease, 1);
         if (!lease)
-                return -ENOBUFS;
+                return -ENOMEM;
 
         len = len - DHCP_IP_UDP_SIZE;
         r = dhcp_option_parse(&offer->dhcp, len, client_parse_offer, lease);
 
-        if (r != DHCP_ACK)
+        if (r == DHCP_NAK) {
+                r = DHCP_EVENT_NO_LEASE;
                 goto error;
+        }
+
+        if (r != DHCP_ACK) {
+                r = -ENOMSG;
+                goto error;
+        }
 
         lease->address = offer->dhcp.yiaddr;
 
@@ -782,11 +902,14 @@ static int client_receive_raw_message(sd_event_source *s, int fd,
 
                         client_notify(client, DHCP_EVENT_IP_ACQUIRE);
 
-                        close(client->fd);
-                        client->fd = -1;
                         client->receive_message =
                                 sd_event_source_unref(client->receive_message);
+                        close(client->fd);
+                        client->fd = -1;
                 }
+
+                r = 0;
+
                 break;
 
         case DHCP_STATE_INIT:
@@ -800,7 +923,7 @@ static int client_receive_raw_message(sd_event_source *s, int fd,
         }
 
 error:
-        if (r < 0)
+        if (r < 0 || r == DHCP_EVENT_NO_LEASE)
                 return client_stop(client, r);
 
         return 0;
@@ -848,7 +971,20 @@ error:
 
 int sd_dhcp_client_stop(sd_dhcp_client *client)
 {
-        return client_stop(client, 0);
+        return client_stop(client, DHCP_EVENT_STOP);
+}
+
+sd_dhcp_client *sd_dhcp_client_free(sd_dhcp_client *client)
+{
+        assert_return(client, NULL);
+
+        sd_dhcp_client_stop(client);
+
+        sd_event_unref(client->event);
+        free(client->req_opts);
+        free(client);
+
+        return NULL;
 }
 
 sd_dhcp_client *sd_dhcp_client_new(sd_event *event)