chiark / gitweb /
sd-dhcp-client: return NULL from _unref() like the other sd-* libraries
[elogind.git] / src / libsystemd-network / sd-dhcp-client.c
index ba44069..1603c41 100644 (file)
@@ -82,7 +82,7 @@ static int client_receive_message_raw(sd_event_source *s, int fd,
                                       uint32_t revents, void *userdata);
 static int client_receive_message_udp(sd_event_source *s, int fd,
                                       uint32_t revents, void *userdata);
-static sd_dhcp_client *client_stop(sd_dhcp_client *client, int error);
+static void client_stop(sd_dhcp_client *client, int error);
 
 int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
                                 void *userdata) {
@@ -153,6 +153,7 @@ int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) {
 
 int sd_dhcp_client_set_mac(sd_dhcp_client *client,
                            const struct ether_addr *addr) {
+        DHCP_CLIENT_DONT_DESTROY(client);
         bool need_restart = false;
 
         assert_return(client, -EINVAL);
@@ -165,12 +166,9 @@ int sd_dhcp_client_set_mac(sd_dhcp_client *client,
                 log_dhcp_client(client, "Changing MAC address on running DHCP "
                                 "client, restarting");
                 need_restart = true;
-                client = client_stop(client, DHCP_EVENT_STOP);
+                client_stop(client, DHCP_EVENT_STOP);
         }
 
-        if (!client)
-                return 0;
-
         memcpy(&client->client_id.mac_addr, addr, ETH_ALEN);
         client->client_id.type = 0x01;
 
@@ -194,14 +192,9 @@ int sd_dhcp_client_get_lease(sd_dhcp_client *client, sd_dhcp_lease **ret) {
         return 0;
 }
 
-static sd_dhcp_client *client_notify(sd_dhcp_client *client, int event) {
-        if (client->cb) {
-                client = sd_dhcp_client_ref(client);
+static void client_notify(sd_dhcp_client *client, int event) {
+        if (client->cb)
                 client->cb(client, event, client->userdata);
-                client = sd_dhcp_client_unref(client);
-        }
-
-        return client;
 }
 
 static int client_initialize(sd_dhcp_client *client) {
@@ -229,8 +222,8 @@ static int client_initialize(sd_dhcp_client *client) {
         return 0;
 }
 
-static sd_dhcp_client *client_stop(sd_dhcp_client *client, int error) {
-        assert_return(client, NULL);
+static void client_stop(sd_dhcp_client *client, int error) {
+        assert(client);
 
         if (error < 0)
                 log_dhcp_client(client, "STOPPED: %s", strerror(-error));
@@ -248,43 +241,59 @@ static sd_dhcp_client *client_stop(sd_dhcp_client *client, int error) {
                 }
         }
 
-        client = client_notify(client, error);
+        client_notify(client, error);
 
-        if (client)
-                client_initialize(client);
-
-        return client;
+        client_initialize(client);
 }
 
-static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
-                               uint8_t type, size_t optlen, size_t *optoffset) {
+static int client_message_init(sd_dhcp_client *client, DHCPPacket **ret,
+                               uint8_t type, size_t *_optlen, size_t *_optoffset) {
+        _cleanup_free_ DHCPPacket *packet;
+        size_t optlen, optoffset, size;
         be16_t max_size;
         int r;
 
         assert(client);
         assert(client->secs);
-        assert(message);
-        assert(optoffset);
+        assert(ret);
+        assert(_optlen);
+        assert(_optoffset);
         assert(type == DHCP_DISCOVER || type == DHCP_REQUEST);
 
-        r = dhcp_message_init(message, BOOTREQUEST, client->xid, type,
-                              optlen, optoffset);
+        optlen = DHCP_MIN_OPTIONS_SIZE;
+        size = sizeof(DHCPPacket) + optlen;
+
+        packet = malloc0(size);
+        if (!packet)
+                return -ENOMEM;
+
+        r = dhcp_message_init(&packet->dhcp, BOOTREQUEST, client->xid, type,
+                              optlen, &optoffset);
         if (r < 0)
                 return r;
 
         /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
            refuse to issue an DHCP lease if 'secs' is set to zero */
-        message->secs = htobe16(client->secs);
+        packet->dhcp.secs = htobe16(client->secs);
+
+        /* RFC2132 section 4.1
+           A client that cannot receive unicast IP datagrams until its protocol
+           software has been configured with an IP address SHOULD set the
+           BROADCAST bit in the 'flags' field to 1 in any DHCPDISCOVER or
+           DHCPREQUEST messages that client sends.  The BROADCAST bit will
+           provide a hint to the DHCP server and BOOTP relay agent to broadcast
+           any messages to the client on the client's subnet. */
+        packet->dhcp.flags = htobe16(0x8000);
 
         /* RFC2132 section 4.1.1:
            The client MUST include its hardware address in the â€™chaddr’ field, if
            necessary for delivery of DHCP reply messages.
          */
-        memcpy(&message->chaddr, &client->client_id.mac_addr, ETH_ALEN);
+        memcpy(&packet->dhcp.chaddr, &client->client_id.mac_addr, ETH_ALEN);
 
         /* Some DHCP servers will refuse to issue an DHCP lease if the Client
            Identifier option is not set */
-        r = dhcp_option_append(message, optlen, optoffset, 0,
+        r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
                                DHCP_OPTION_CLIENT_IDENTIFIER,
                                sizeof(client->client_id), &client->client_id);
         if (r < 0)
@@ -299,7 +308,7 @@ static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
            it MUST include that list in any subsequent DHCPREQUEST
            messages.
          */
-        r = dhcp_option_append(message, optlen, optoffset, 0,
+        r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
                                DHCP_OPTION_PARAMETER_REQUEST_LIST,
                                client->req_opts_size, client->req_opts);
         if (r < 0)
@@ -313,14 +322,18 @@ static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
            than the defined default size unless the Maximum Messge Size option
            is explicitely set
          */
-        max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE +
-                           DHCP_MIN_OPTIONS_SIZE);
-        r = dhcp_option_append(message, optlen, optoffset, 0,
+        max_size = htobe16(size);
+        r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
                                DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
                                2, &max_size);
         if (r < 0)
                 return r;
 
+        *_optlen = optlen;
+        *_optoffset = optoffset;
+        *ret = packet;
+        packet = NULL;
+
         return 0;
 }
 
@@ -335,7 +348,7 @@ static int dhcp_client_send_raw(sd_dhcp_client *client, DHCPPacket *packet,
 
 static int client_send_discover(sd_dhcp_client *client) {
         _cleanup_free_ DHCPPacket *discover = NULL;
-        size_t optoffset, optlen, len;
+        size_t optoffset, optlen;
         usec_t time_now;
         int r;
 
@@ -354,15 +367,8 @@ static int client_send_discover(sd_dhcp_client *client) {
          * must always be strictly positive to deal with broken servers */
         client->secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1;
 
-        optlen = DHCP_MIN_OPTIONS_SIZE;
-        len = sizeof(DHCPPacket) + optlen;
-
-        discover = malloc0(len);
-        if (!discover)
-                return -ENOMEM;
-
-        r = client_message_init(client, &discover->dhcp, DHCP_DISCOVER,
-                                optlen, &optoffset);
+        r = client_message_init(client, &discover, DHCP_DISCOVER,
+                                &optlen, &optoffset);
         if (r < 0)
                 return r;
 
@@ -382,6 +388,8 @@ static int client_send_discover(sd_dhcp_client *client) {
 
         r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
                                DHCP_OPTION_END, 0, NULL);
+        if (r < 0)
+                return r;
 
         /* We currently ignore:
            The client SHOULD wait a random time between one and ten seconds to
@@ -397,19 +405,12 @@ static int client_send_discover(sd_dhcp_client *client) {
 }
 
 static int client_send_request(sd_dhcp_client *client) {
-        _cleanup_free_ DHCPPacket *request;
-        size_t optoffset, optlen, len;
+        _cleanup_free_ DHCPPacket *request = NULL;
+        size_t optoffset, optlen;
         int r;
 
-        optlen = DHCP_MIN_OPTIONS_SIZE;
-        len = sizeof(DHCPPacket) + optlen;
-
-        request = malloc0(len);
-        if (!request)
-                return -ENOMEM;
-
-        r = client_message_init(client, &request->dhcp, DHCP_REQUEST,
-                                optlen, &optoffset);
+        r = client_message_init(client, &request, DHCP_REQUEST,
+                                &optlen, &optoffset);
         if (r < 0)
                 return r;
 
@@ -519,6 +520,7 @@ static int client_start(sd_dhcp_client *client);
 static int client_timeout_resend(sd_event_source *s, uint64_t usec,
                                  void *userdata) {
         sd_dhcp_client *client = userdata;
+        DHCP_CLIENT_DONT_DESTROY(client);
         usec_t next_timeout = 0;
         uint64_t time_now;
         uint32_t time_left;
@@ -726,13 +728,14 @@ static int client_start(sd_dhcp_client *client) {
 static int client_timeout_expire(sd_event_source *s, uint64_t usec,
                                  void *userdata) {
         sd_dhcp_client *client = userdata;
+        DHCP_CLIENT_DONT_DESTROY(client);
 
         log_dhcp_client(client, "EXPIRED");
 
-        client = client_notify(client, DHCP_EVENT_EXPIRED);
+        client_notify(client, DHCP_EVENT_EXPIRED);
 
         /* lease was lost, start over if not freed or stopped in callback */
-        if (client && client->state != DHCP_STATE_STOPPED) {
+        if (client->state != DHCP_STATE_STOPPED) {
                 client_initialize(client);
                 client_start(client);
         }
@@ -742,6 +745,7 @@ static int client_timeout_expire(sd_event_source *s, uint64_t usec,
 
 static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) {
         sd_dhcp_client *client = userdata;
+        DHCP_CLIENT_DONT_DESTROY(client);
         int r;
 
         client->receive_message = sd_event_source_unref(client->receive_message);
@@ -763,6 +767,7 @@ static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata)
 static int client_timeout_t1(sd_event_source *s, uint64_t usec,
                              void *userdata) {
         sd_dhcp_client *client = userdata;
+        DHCP_CLIENT_DONT_DESTROY(client);
         int r;
 
         client->state = DHCP_STATE_RENEWING;
@@ -1034,6 +1039,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
 
 static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
                                  int len) {
+        DHCP_CLIENT_DONT_DESTROY(client);
         int r = 0, notify_event = 0;
 
         assert(client);
@@ -1143,9 +1149,8 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
                                 goto error;
 
                         if (notify_event) {
-                                client = client_notify(client, notify_event);
-                                if (!client ||
-                                    client->state == DHCP_STATE_STOPPED)
+                                client_notify(client, notify_event);
+                                if (client->state == DHCP_STATE_STOPPED)
                                         return 0;
                         }
 
@@ -1200,7 +1205,7 @@ static int client_receive_message_udp(sd_event_source *s, int fd,
         len = read(fd, message, buflen);
         if (len < 0) {
                 log_dhcp_client(client, "could not receive message from UDP "
-                                "socket: %s", strerror(errno));
+                                "socket: %m");
                 return 0;
         } else if ((size_t)len < sizeof(DHCPMessage))
                 return 0;
@@ -1245,7 +1250,7 @@ static int client_receive_message_raw(sd_event_source *s, int fd,
         len = recvmsg(fd, &msg, 0);
         if (len < 0) {
                 log_dhcp_client(client, "could not receive message from raw "
-                                "socket: %s", strerror(errno));
+                                "socket: %m");
                 return 0;
         } else if ((size_t)len < sizeof(DHCPPacket))
                 return 0;
@@ -1292,10 +1297,12 @@ int sd_dhcp_client_start(sd_dhcp_client *client) {
 }
 
 int sd_dhcp_client_stop(sd_dhcp_client *client) {
+        DHCP_CLIENT_DONT_DESTROY(client);
+
         assert_return(client, -EINVAL);
 
-        if (client_stop(client, DHCP_EVENT_STOP))
-                client->state = DHCP_STATE_STOPPED;
+        client_stop(client, DHCP_EVENT_STOP);
+        client->state = DHCP_STATE_STOPPED;
 
         return 0;
 }
@@ -1344,7 +1351,7 @@ sd_dhcp_client *sd_dhcp_client_ref(sd_dhcp_client *client) {
 
 sd_dhcp_client *sd_dhcp_client_unref(sd_dhcp_client *client) {
         if (client && REFCNT_DEC(client->n_ref) <= 0) {
-                log_dhcp_client(client, "UNREF");
+                log_dhcp_client(client, "FREE");
 
                 client_initialize(client);
 
@@ -1357,18 +1364,13 @@ sd_dhcp_client *sd_dhcp_client_unref(sd_dhcp_client *client) {
 
                 free(client->req_opts);
                 free(client);
-
-                return NULL;
         }
 
-        return client;
+        return NULL;
 }
 
-DEFINE_TRIVIAL_CLEANUP_FUNC(sd_dhcp_client*, sd_dhcp_client_unref);
-#define _cleanup_dhcp_client_free_ _cleanup_(sd_dhcp_client_unrefp)
-
 int sd_dhcp_client_new(sd_dhcp_client **ret) {
-        _cleanup_dhcp_client_free_ sd_dhcp_client *client = NULL;
+        _cleanup_dhcp_client_unref_ sd_dhcp_client *client = NULL;
 
         assert_return(ret, -EINVAL);