#include <stdio.h>
#include <net/ethernet.h>
#include <net/if_arp.h>
+#include <netinet/ether.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include "util.h"
#include "list.h"
+#include "refcnt.h"
+#include "async.h"
#include "dhcp-protocol.h"
#include "dhcp-internal.h"
#include "sd-dhcp-client.h"
struct sd_dhcp_client {
+ RefCount n_ref;
+
DHCPState state;
sd_event *event;
int event_priority;
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);
int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
void *userdata) {
size_t i;
assert_return(client, -EINVAL);
- assert_return (client->state == DHCP_STATE_INIT, -EBUSY);
+ assert_return (IN_SET(client->state, DHCP_STATE_INIT,
+ DHCP_STATE_STOPPED), -EBUSY);
switch(option) {
case DHCP_OPTION_PAD:
int sd_dhcp_client_set_request_address(sd_dhcp_client *client,
const struct in_addr *last_addr) {
assert_return(client, -EINVAL);
- assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
+ assert_return (IN_SET(client->state, DHCP_STATE_INIT,
+ DHCP_STATE_STOPPED), -EBUSY);
if (last_addr)
client->last_addr = last_addr->s_addr;
int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) {
assert_return(client, -EINVAL);
- assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
- assert_return(interface_index >= -1, -EINVAL);
+ assert_return (IN_SET(client->state, DHCP_STATE_INIT,
+ DHCP_STATE_STOPPED), -EBUSY);
+ assert_return(interface_index > 0, -EINVAL);
client->index = interface_index;
if (memcmp(&client->client_id.mac_addr, addr, ETH_ALEN) == 0)
return 0;
- if (client->state != DHCP_STATE_INIT) {
+ if (!IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED)) {
log_dhcp_client(client, "Changing MAC address on running DHCP "
"client, restarting");
- sd_dhcp_client_stop(client);
need_restart = true;
+ client = client_stop(client, DHCP_EVENT_STOP);
}
+ if (!client)
+ return 0;
+
memcpy(&client->client_id.mac_addr, addr, ETH_ALEN);
client->client_id.type = 0x01;
- if (need_restart)
+ if (need_restart && client->state != DHCP_STATE_STOPPED)
sd_dhcp_client_start(client);
return 0;
return 0;
}
-static int client_notify(sd_dhcp_client *client, int event) {
- if (client->cb)
+static sd_dhcp_client *client_notify(sd_dhcp_client *client, int event) {
+ if (client->cb) {
+ client = sd_dhcp_client_ref(client);
client->cb(client, event, client->userdata);
+ client = sd_dhcp_client_unref(client);
+ }
- return 0;
+ return client;
}
static int client_initialize(sd_dhcp_client *client) {
client->receive_message =
sd_event_source_unref(client->receive_message);
- client->fd = safe_close(client->fd);
+ client->fd = asynchronous_close(client->fd);
client->timeout_resend = sd_event_source_unref(client->timeout_resend);
return 0;
}
-static int client_stop(sd_dhcp_client *client, int error) {
- assert_return(client, -EINVAL);
+static sd_dhcp_client *client_stop(sd_dhcp_client *client, int error) {
+ assert_return(client, NULL);
- client_notify(client, error);
+ if (error < 0)
+ log_dhcp_client(client, "STOPPED: %s", strerror(-error));
+ else {
+ switch(error) {
+ case DHCP_EVENT_STOP:
+ log_dhcp_client(client, "STOPPED");
+ break;
+ case DHCP_EVENT_NO_LEASE:
+ log_dhcp_client(client, "STOPPED: No lease");
+ break;
+ default:
+ log_dhcp_client(client, "STOPPED: Unknown reason");
+ break;
+ }
+ }
- client_initialize(client);
+ client = client_notify(client, error);
- log_dhcp_client(client, "STOPPED");
+ if (client)
+ client_initialize(client);
- return 0;
+ return client;
}
-static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
- uint8_t type, uint8_t **opt, size_t *optlen) {
+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(opt);
- assert(optlen);
+ assert(ret);
+ assert(_optlen);
+ assert(_optoffset);
+ assert(type == DHCP_DISCOVER || type == DHCP_REQUEST);
+
+ optlen = DHCP_MIN_OPTIONS_SIZE;
+ size = sizeof(DHCPPacket) + optlen;
- r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt,
- 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);
-
- memcpy(&message->chaddr, &client->client_id.mac_addr, ETH_ALEN);
+ packet->dhcp.secs = htobe16(client->secs);
- if (client->state == DHCP_STATE_RENEWING ||
- client->state == DHCP_STATE_REBINDING)
- message->ciaddr = client->lease->address;
+ /* RFC2132 section 4.1.1:
+ The client MUST include its hardware address in the ’chaddr’ field, if
+ necessary for delivery of DHCP reply messages.
+ */
+ 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(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER,
+ r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
+ DHCP_OPTION_CLIENT_IDENTIFIER,
sizeof(client->client_id), &client->client_id);
if (r < 0)
return r;
- if (type == DHCP_DISCOVER || type == DHCP_REQUEST) {
- be16_t max_size;
- r = dhcp_option_append(opt, optlen,
- DHCP_OPTION_PARAMETER_REQUEST_LIST,
- client->req_opts_size,
- client->req_opts);
- if (r < 0)
- return r;
+ /* RFC2131 section 3.5:
+ in its initial DHCPDISCOVER or DHCPREQUEST message, a
+ client may provide the server with a list of specific
+ parameters the client is interested in. If the client
+ includes a list of parameters in a DHCPDISCOVER message,
+ it MUST include that list in any subsequent DHCPREQUEST
+ messages.
+ */
+ r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
+ DHCP_OPTION_PARAMETER_REQUEST_LIST,
+ client->req_opts_size, client->req_opts);
+ if (r < 0)
+ return r;
- /* Some DHCP servers will send bigger DHCP packets 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(opt, optlen,
- DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
- 2, &max_size);
- if (r < 0)
- return r;
- }
+ /* RFC2131 section 3.5:
+ The client SHOULD include the ’maximum DHCP message size’ option to
+ let the server know how large the server may make its DHCP messages.
+
+ Note (from ConnMan): Some DHCP servers will send bigger DHCP packets
+ than the defined default size unless the Maximum Messge Size option
+ is explicitely set
+ */
+ 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;
}
static int client_send_discover(sd_dhcp_client *client) {
_cleanup_free_ DHCPPacket *discover = NULL;
- size_t optlen, len;
- uint8_t *opt;
+ size_t optoffset, optlen;
usec_t time_now;
int r;
assert(client);
+ assert(client->state == DHCP_STATE_INIT ||
+ client->state == DHCP_STATE_SELECTING);
+
+ /* See RFC2131 section 4.4.1 */
r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
if (r < 0)
* 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,
- &opt, &optlen);
+ r = client_message_init(client, &discover, DHCP_DISCOVER,
+ &optlen, &optoffset);
if (r < 0)
return r;
+ /* the client may suggest values for the network address
+ and lease time in the DHCPDISCOVER message. The client may include
+ the ’requested IP address’ option to suggest that a particular IP
+ address be assigned, and may include the ’IP address lease time’
+ option to suggest the lease time it would like.
+ */
if (client->last_addr != INADDR_ANY) {
- r = dhcp_option_append(&opt, &optlen,
- DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->last_addr);
+ r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
+ DHCP_OPTION_REQUESTED_IP_ADDRESS,
+ 4, &client->last_addr);
if (r < 0)
return r;
}
- r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
- if (r < 0)
- return r;
+ r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
+ DHCP_OPTION_END, 0, NULL);
- r = dhcp_client_send_raw(client, discover, len - optlen);
+ /* We currently ignore:
+ The client SHOULD wait a random time between one and ten seconds to
+ desynchronize the use of DHCP at startup.
+ */
+ r = dhcp_client_send_raw(client, discover, sizeof(DHCPPacket) + optoffset);
if (r < 0)
return r;
static int client_send_request(sd_dhcp_client *client) {
_cleanup_free_ DHCPPacket *request;
- size_t optlen, len;
- uint8_t *opt;
+ 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, &opt,
- &optlen);
+ r = client_message_init(client, &request, DHCP_REQUEST,
+ &optlen, &optoffset);
if (r < 0)
return r;
switch (client->state) {
+ /* See RFC2131 section 4.3.2 (note that there is a typo in the RFC,
+ SELECTING should be REQUESTING)
+ */
- case DHCP_STATE_INIT_REBOOT:
- r = dhcp_option_append(&opt, &optlen,
- DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->last_addr);
+ case DHCP_STATE_REQUESTING:
+ /* Client inserts the address of the selected server in ’server
+ identifier’, ’ciaddr’ MUST be zero, ’requested IP address’ MUST be
+ filled in with the yiaddr value from the chosen DHCPOFFER.
+ */
+
+ r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
+ DHCP_OPTION_SERVER_IDENTIFIER,
+ 4, &client->lease->server_address);
if (r < 0)
return r;
- break;
- case DHCP_STATE_REQUESTING:
- r = dhcp_option_append(&opt, &optlen,
+ r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->lease->address);
if (r < 0)
return r;
- r = dhcp_option_append(&opt, &optlen,
- DHCP_OPTION_SERVER_IDENTIFIER,
- 4, &client->lease->server_address);
+ break;
+
+ case DHCP_STATE_INIT_REBOOT:
+ /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
+ option MUST be filled in with client’s notion of its previously
+ assigned address. ’ciaddr’ MUST be zero.
+ */
+ r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
+ DHCP_OPTION_REQUESTED_IP_ADDRESS,
+ 4, &client->last_addr);
if (r < 0)
return r;
break;
- case DHCP_STATE_INIT:
- case DHCP_STATE_SELECTING:
- case DHCP_STATE_REBOOTING:
- case DHCP_STATE_BOUND:
case DHCP_STATE_RENEWING:
+ /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
+ option MUST NOT be filled in, ’ciaddr’ MUST be filled in with
+ client’s IP address.
+ */
+
+ /* fall through */
case DHCP_STATE_REBINDING:
+ /* ’server identifier’ MUST NOT be filled in, ’requested IP address’
+ option MUST NOT be filled in, ’ciaddr’ MUST be filled in with
+ client’s IP address.
+
+ This message MUST be broadcast to the 0xffffffff IP broadcast address.
+ */
+ request->dhcp.ciaddr = client->lease->address;
break;
+
+ case DHCP_STATE_INIT:
+ case DHCP_STATE_SELECTING:
+ case DHCP_STATE_REBOOTING:
+ case DHCP_STATE_BOUND:
+ case DHCP_STATE_STOPPED:
+ return -EINVAL;
}
- r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
+ r = dhcp_option_append(&request->dhcp, optlen, &optoffset, 0,
+ DHCP_OPTION_END, 0, NULL);
if (r < 0)
return r;
client->lease->server_address,
DHCP_PORT_SERVER,
&request->dhcp,
- len - optlen - DHCP_IP_UDP_SIZE);
+ sizeof(DHCPMessage) + optoffset);
} else {
- r = dhcp_client_send_raw(client, request, len - optlen);
+ r = dhcp_client_send_raw(client, request, sizeof(DHCPPacket) + optoffset);
}
if (r < 0)
return r;
- log_dhcp_client(client, "REQUEST");
+ switch (client->state) {
+ case DHCP_STATE_REQUESTING:
+ log_dhcp_client(client, "REQUEST (requesting)");
+ break;
+ case DHCP_STATE_INIT_REBOOT:
+ log_dhcp_client(client, "REQUEST (init-reboot)");
+ break;
+ case DHCP_STATE_RENEWING:
+ log_dhcp_client(client, "REQUEST (renewing)");
+ break;
+ case DHCP_STATE_REBINDING:
+ log_dhcp_client(client, "REQUEST (rebinding)");
+ break;
+ default:
+ log_dhcp_client(client, "REQUEST (invalid)");
+ break;
+ }
return 0;
}
+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;
case DHCP_STATE_REBOOTING:
/* start over as we did not receive a timely ack or nak */
- client->state = DHCP_STATE_INIT;
- client->attempt = 1;
- client->xid = random_u32();
+ r = client_initialize(client);
+ if (r < 0)
+ goto error;
+
+ r = client_start(client);
+ if (r < 0)
+ goto error;
+ else {
+ log_dhcp_client(client, "REBOOTED");
+ return 0;
+ }
- /* fall through */
case DHCP_STATE_INIT:
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_SELECTING:
next_timeout = time_now + (client->attempt - 1) * USEC_PER_SEC;
break;
+
+ case DHCP_STATE_STOPPED:
+ r = -EINVAL;
+ goto error;
}
next_timeout += (random_u32() & 0x1fffff);
case DHCP_STATE_BOUND:
break;
+
+ case DHCP_STATE_STOPPED:
+ r = -EINVAL;
+ goto error;
}
return 0;
client->xid = random_u32();
r = dhcp_network_bind_raw_socket(client->index, &client->link, client->xid);
-
if (r < 0) {
client_stop(client, r);
return r;
client->secs = 0;
}
- log_dhcp_client(client, "STARTED");
-
return client_initialize_events(client, client_receive_message_raw);
}
log_dhcp_client(client, "EXPIRED");
- client_notify(client, DHCP_EVENT_EXPIRED);
+ client = client_notify(client, DHCP_EVENT_EXPIRED);
- /* start over as the lease was lost */
- client_initialize(client);
- client_start(client);
+ /* lease was lost, start over if not freed or stopped in callback */
+ if (client && client->state != DHCP_STATE_STOPPED) {
+ client_initialize(client);
+ client_start(client);
+ }
return 0;
}
int r;
client->receive_message = sd_event_source_unref(client->receive_message);
- client->fd = safe_close(client->fd);
+ client->fd = asynchronous_close(client->fd);
client->state = DHCP_STATE_REBINDING;
client->attempt = 1;
client_stop(client, r);
return 0;
}
-
client->fd = r;
- log_dhcp_client(client, "TIMEOUT T2");
-
return client_initialize_events(client, client_receive_message_raw);
}
client->state = DHCP_STATE_RENEWING;
client->attempt = 1;
- r = dhcp_network_bind_udp_socket(client->index,
- client->lease->address,
+ r = dhcp_network_bind_udp_socket(client->lease->address,
DHCP_PORT_CLIENT);
if (r < 0) {
client_stop(client, r);
client->fd = r;
- log_dhcp_client(client, "TIMEOUT T1");
-
return client_initialize_events(client, client_receive_message_udp);
}
}
}
+ sd_dhcp_lease_unref(client->lease);
client->lease = lease;
lease = NULL;
r = client_start(client);
if (r < 0)
goto error;
+
+ log_dhcp_client(client, "REBOOTED");
}
goto error;
if (r < 0)
goto error;
- if (notify_event)
- client_notify(client, notify_event);
+ if (notify_event) {
+ client = client_notify(client, notify_event);
+ if (!client ||
+ client->state == DHCP_STATE_STOPPED)
+ return 0;
+ }
client->receive_message =
sd_event_source_unref(client->receive_message);
- client->fd = safe_close(client->fd);
+ client->fd = asynchronous_close(client->fd);
} else if (r == -ENOMSG)
/* invalid message, let's ignore it */
return 0;
case DHCP_STATE_BOUND:
break;
+
+ case DHCP_STATE_STOPPED:
+ r = -EINVAL;
+ goto error;
}
error:
if (r < 0 || r == DHCP_EVENT_NO_LEASE)
- return client_stop(client, r);
+ client_stop(client, r);
- return 0;
+ return r;
}
static int client_receive_message_udp(sd_event_source *s, int fd,
assert(client);
r = ioctl(fd, FIONREAD, &buflen);
- if (r < 0 || buflen <= 0)
- buflen = sizeof(DHCPMessage) + DHCP_MIN_OPTIONS_SIZE;
+ if (r < 0)
+ return r;
+
+ if (buflen < 0)
+ /* this can't be right */
+ return -EIO;
message = malloc0(buflen);
if (!message)
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;
assert(client);
r = ioctl(fd, FIONREAD, &buflen);
- if (r < 0 || buflen <= 0)
- buflen = sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE;
+ if (r < 0)
+ return r;
+
+ if (buflen < 0)
+ /* this can't be right */
+ return -EIO;
packet = malloc0(buflen);
if (!packet)
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;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
- if (cmsg->cmsg_level == SOL_PACKET && cmsg->cmsg_type == PACKET_AUXDATA) {
- struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
+ if (cmsg->cmsg_level == SOL_PACKET &&
+ cmsg->cmsg_type == PACKET_AUXDATA &&
+ cmsg->cmsg_len == CMSG_LEN(sizeof(struct tpacket_auxdata))) {
+ struct tpacket_auxdata *aux = (struct tpacket_auxdata*)CMSG_DATA(cmsg);
checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
break;
if (client->last_addr)
client->state = DHCP_STATE_INIT_REBOOT;
- return client_start(client);
+ r = client_start(client);
+ if (r >= 0)
+ log_dhcp_client(client, "STARTED on ifindex %u with address %s",
+ client->index,
+ ether_ntoa(&client->client_id.mac_addr));
+
+ return r;
}
int sd_dhcp_client_stop(sd_dhcp_client *client) {
- return client_stop(client, DHCP_EVENT_STOP);
+ assert_return(client, -EINVAL);
+
+ if (client_stop(client, DHCP_EVENT_STOP))
+ client->state = DHCP_STATE_STOPPED;
+
+ return 0;
}
int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event,
return client->event;
}
-void sd_dhcp_client_free(sd_dhcp_client *client) {
- if (!client)
- return;
+sd_dhcp_client *sd_dhcp_client_ref(sd_dhcp_client *client) {
+ if (client)
+ assert_se(REFCNT_INC(client->n_ref) >= 2);
+
+ return client;
+}
- sd_dhcp_client_stop(client);
- sd_dhcp_client_detach_event(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");
+
+ client_initialize(client);
+
+ client->receive_message =
+ sd_event_source_unref(client->receive_message);
+
+ sd_dhcp_client_detach_event(client);
+
+ sd_dhcp_lease_unref(client->lease);
+
+ free(client->req_opts);
+ free(client);
+
+ return NULL;
+ }
- free(client->req_opts);
- free(client);
+ return client;
}
-DEFINE_TRIVIAL_CLEANUP_FUNC(sd_dhcp_client*, sd_dhcp_client_free);
-#define _cleanup_dhcp_client_free_ _cleanup_(sd_dhcp_client_freep)
+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;
if (!client)
return -ENOMEM;
+ client->n_ref = REFCNT_INIT;
client->state = DHCP_STATE_INIT;
client->index = -1;
client->fd = -1;
~ianmdlvl / elogind.git / blobdiff